英文文献及翻译
英文文献翻译
外文文献原稿和译文原稿Sodium Polyacrylate:Also known as super-absorbent or “SAP”(super absorbent polymer), Kimberly Clark used to call it SAM (super absorbent material). It is typically used in fine granular form (like table salt). It helps improve capacity for better retention in a disposable diaper, allowing the product to be thinner with improved performance and less usage of pine fluff pulp. The molecular structure of the polyacrylate has sodium carboxylate groups hanging off the main chain. When it comes in contact with water, the sodium detaches itself, leaving only carboxylions. Being negatively charged, these ions repel one another so that the polymer also has cross-links, which effectively leads to a three-dimensional structure. It has hige molecular weight of more than a million; thus, instead of getting dissolved, it solidifies into a gel. The Hydrogen in the water (H-O-H) is trapped by the acrylate due to the atomic bonds associated with the polarity forces between the atoms. Electrolytes in the liquid, such as salt minerals (urine contains 0.9% of minerals), reduce polarity, thereby affecting superabsorbent properties, especially with regard to the superabsorbent capacity for liquid retention. This is the main reason why diapers containing SAP should never be tested with plain water. Linear molecular configurations have less total capacity than non-linear molecules but, on the other hand, retention of liquid in a linear molecule is higher than in a non-linear molecule, due to improved polarity. For a list of SAP suppliers, please use this link: SAP, the superabsorbent can be designed to absorb higher amounts of liquids (with less retention) or very high retentions (but lower capacity). In addition, a surface cross linker can be added to the superabsorbent particle to help it move liquids while it is saturated. This helps avoid formation of "gel blocks", the phenomenon that describes the impossibility of moving liquids once a SAP particle gets saturated.History of Super Absorbent Polymer ChemistryUn til the 1980’s, water absorbing materials were cellulosic or fiber-based products. Choices were tissue paper, cotton, sponge, and fluff pulp. The water retention capacity of these types of materials is only 20 times their weight – at most.In the early 1960s, the United States Department of Agriculture (USDA) was conducting work on materials to improve water conservation in soils. They developed a resin based on the grafting of acrylonitrile polymer onto the backbone of starch molecules (i.e. starch-grafting). The hydrolyzed product of the hydrolysis of this starch-acrylonitrile co-polymer gave water absorption greater than 400 times its weight. Also, the gel did not release liquid water the way that fiber-based absorbents do.The polymer came to be known as “Super Slurper”.The USDA gave the technical know how several USA companies for further development of the basic technology. A wide range of grating combinations were attempted including work with acrylic acid, acrylamide and polyvinyl alcohol (PVA).Since Japanese companies were excluded by the USDA, they started independent research using starch, carboxy methyl cellulose (CMC), acrylic acid, polyvinyl alcohol (PVA) and isobutylene maleic anhydride (IMA).Early global participants in the development of super absorbent chemistry included Dow Chemical, Hercules, General Mills Chemical, DuPont, National Starch & Chemical, Enka (Akzo), Sanyo Chemical, Sumitomo Chemical, Kao, Nihon Starch and Japan Exlan.In the early 1970s, super absorbent polymer was used commercially for the first time –not for soil amendment applications as originally intended –but for disposable hygienic products. The first product markets were feminine sanitary napkins and adult incontinence products.In 1978, Park Davis (d.b.a. Professional Medical Products) used super absorbent polymers in sanitary napkins.Super absorbent polymer was first used in Europe in a baby diaper in 1982 when Schickendanz and Beghin-Say added the material to the absorbent core. Shortly thereafter, UniCharm introduced super absorbent baby diapers in Japan while Proctor & Gamble and Kimberly-Clark in the USA began to use the material.The development of super absorbent technology and performance has been largely led by demands in the disposable hygiene segment. Strides in absorption performance have allowed the development of the ultra-thin baby diaper which uses a fraction of the materials – particularly fluff pulp – which earlier disposable diapers consumed.Over the years, technology has progressed so that there is little if any starch-grafted super absorbent polymer used in disposable hygienic products. These super absorbents typically are cross-linked acrylic homo-polymers (usually Sodium neutralized).Super absorbents used in soil amendments applications tend to be cross-linked acrylic-acrylamide co-polymers (usually Potassium neutralized).Besides granular super absorbent polymers, ARCO Chemical developed a super absorbent fiber technology in the early 1990s. This technology was eventually sold to Camelot Absorbents. There are super absorbent fibers commercially available today. While significantly more expensive than the granular polymers, the super absorbent fibers offer technical advantages in certain niche markets including cable wrap, medical devices and food packaging.Sodium polyacrylate, also known as waterlock, is a polymer with the chemical formula [-CH2-CH(COONa)-]n widely used in consumer products. It has the ability to absorb as much as 200 to 300 times its mass in water. Acrylate polymers generally are considered to possess an anionic charge. While sodium neutralized polyacrylates are the most common form used in industry, there are also other salts available including potassium, lithium and ammonium.ApplicationsAcrylates and acrylic chemistry have a wide variety of industrial uses that include: ∙Sequestering agents in detergents. (By binding hard water elements such as calcium and magnesium, the surfactants in detergents work more efficiently.) ∙Thickening agents∙Coatings∙Fake snowSuper absorbent polymers. These cross-linked acrylic polymers are referred to as "Super Absorbents" and "Water Crystals", and are used in baby diapers. Copolymerversions are used in agriculture and other specialty absorbent applications. The origins of super absorbent polymer chemistry trace back to the early 1960s when the U.S. Department of Agriculture developed the first super absorbent polymer materials. This chemical is featured in the Maximum Absorbency Garment used by NASA.译文聚丙烯酸钠聚丙烯酸钠，又可以称为超级吸收剂或者又叫高吸水性树脂，凯博利克拉克教授曾经称它为SAM即：超级吸收性物质。
中英文文献以及翻译(化工类)
Foreign material：Chemical Industry1.Origins of the Chemical IndustryAlthough the use of chemicals dates back to the ancient civilizations, the evolution of what we know as the modern chemical industry started much more recently. It may be considered to have begun during the Industrial Revolution, about 1800, and developed to provide chemicals roe use by other industries. Examples are alkali for soapmaking, bleaching powder for cotton, and silica and sodium carbonate for glassmaking. It will be noted that these are all inorganic chemicals. The organic chemicals industry started in the 1860s with the exploitation of William Henry Perkin’s discovery if the first synthetic dyestuff—mauve. At the start of the twentieth century the emphasis on research on the applied aspects of chemistry in Germany had paid off handsomely, and by 1914 had resulted in the German chemical industry having 75% of the world market in chemicals. This was based on the discovery of new dyestuffs plus the development of both the contact process for sulphuric acid and the Haber process for ammonia. The later required a major technological breakthrough that of being able to carry out chemical reactions under conditions of very high pressure for the first time. The experience gained with this was to stand Germany in good stead, particularly with the rapidly increased demand for nitrogen-based compounds (ammonium salts for fertilizers and nitric acid for explosives manufacture) with the outbreak of world warⅠin 1914. This initiated profound changes which continued during the inter-war years (1918-1939).Since 1940 the chemical industry has grown at a remarkable rate, although this has slowed significantly in recent years. The lion’s share of this growth has been in the organic chemicals sector due to the development and growth of the petrochemicals area since 1950s. The explosives growth in petrochemicals in the 1960s and 1970s was largely due to the enormous increase in demand for synthetic polymers such as polyethylene, polypropylene, nylon, polyesters and epoxy resins.The chemical industry today is a very diverse sector of manufacturing industry, within which it plays a central role. It makes thousands of different chemicals whichthe general public only usually encounter as end or consumer products. These products are purchased because they have the required properties which make them suitable for some particular application, e.g. a non-stick coating for pans or a weedkiller. Thus chemicals are ultimately sold for the effects that they produce.2. Definition of the Chemical IndustryAt the turn of the century there would have been little difficulty in defining what constituted the chemical industry since only a very limited range of products was manufactured and these were clearly chemicals, e.g., alkali, sulphuric acid. At present, however, many intermediates to products produced, from raw materials like crude oil through (in some cases) many intermediates to products which may be used directly as consumer goods, or readily converted into them. The difficulty cones in deciding at which point in this sequence the particular operation ceases to be part of the chemical industry’s sphere of activities. To consider a specific example to illustrate this dilemma, emulsion paints may contain poly (vinyl chloride) / poly (vinyl acetate). Clearly, synthesis of vinyl chloride (or acetate) and its polymerization are chemical activities. However, if formulation and mixing of the paint, including the polymer, is carried out by a branch of the multinational chemical company which manufactured the ingredients, is this still part of the chemical industry of does it mow belong in the decorating industry?It is therefore apparent that, because of its diversity of operations and close links in many areas with other industries, there is no simple definition of the chemical industry. Instead each official body which collects and publishes statistics on manufacturing industry will have its definition as to which operations are classified as the chemical industry. It is important to bear this in mind when comparing statistical information which is derived from several sources.3. The Need for Chemical IndustryThe chemical industry is concerned with converting raw materials, such as crude oil, firstly into chemical intermediates and then into a tremendous variety of other chemicals. These are then used to produce consumer products, which make our livesmore comfortable or, in some cases such as pharmaceutical produces, help to maintain our well-being or even life itself. At each stage of these operations value is added to the produce and provided this added exceeds the raw material plus processing costs then a profit will be made on the operation. It is the aim of chemical industry to achieve this.It may seem strange in textbook this one to pose the question “do we need a chemical industry?” However trying to answer this question will provide(ⅰ) an indication of the range of the chemical industry’s activities, (ⅱ) its influence on our lives in everyday terms, and (ⅲ) how great is society’s need for a chemical industry. Our approach in answering the question will be to consider the industry’s co ntribution to meeting and satisfying our major needs. What are these? Clearly food (and drink) and health are paramount. Other which we shall consider in their turn are clothing and (briefly) shelter, leisure and transport.(1)Food. The chemical industry makes a major contribution to food production in at least three ways. Firstly, by making available large quantities of artificial fertilizers which are used to replace the elements (mainly nitrogen, phosphorus and potassium) which are removed as nutrients by the growing crops during modern intensive farming. Secondly, by manufacturing crop protection chemicals, i.e., pesticides, which markedly reduce the proportion of the crops consumed by pests. Thirdly, by producing veterinary products which protect livestock from disease or cure their infections.(2)Health. We are all aware of the major contribution which the pharmaceutical sector of the industry has made to help keep us all healthy, e.g. by curing bacterial infections with antibiotics, and even extending life itself, e.g. ß–blockers to lower blood pressure.(3)Clothing. The improvement in properties of modern synthetic fibers over the traditional clothing materials (e.g. cotton and wool) has been quite remarkable. Thus shirts, dresses and suits made from polyesters like Terylene and polyamides like Nylon are crease-resistant, machine-washable, and drip-dry or non-iron. They are also cheaper than natural materials.Parallel developments in the discovery of modern synthetic dyes and the technology to “bond” th em to the fiber has resulted in a tremendous increase in the variety of colors available to the fashion designer. Indeed they now span almost every color and hue of the visible spectrum. Indeed if a suitable shade is not available, structural modification of an existing dye to achieve this canreadily be carried out, provided there is a satisfactory market for the product.Other major advances in this sphere have been in color-fastness, i.e., resistance to the dye being washed out when the garment is cleaned.(4)Shelter, leisure and transport. In terms of shelter the contribution of modern synthetic polymers has been substantial. Plastics are tending to replace traditional building materials like wood because they are lighter, maintenance-free (i.e. they are resistant to weathering and do not need painting). Other polymers, e.g. urea-formaldehyde and polyurethanes, are important insulating materials f or reducing heat losses and hence reducing energy usage.Plastics and polymers have made a considerable impact on leisure activities with applications ranging from all-weather artificial surfaces for athletic tracks, football pitches and tennis courts to nylon strings for racquets and items like golf balls and footballs made entirely from synthetic materials.Like wise the chemical industry’s contribution to transport over the years has led to major improvements. Thus development of improved additives like anti-oxidants and viscosity index improves for engine oil has enabled routine servicing intervals to increase from 3000 to 6000 to 12000 miles. Research and development work has also resulted in improved lubricating oils and greases, and better brake fluids. Yet again the contribution of polymers and plastics has been very striking with the proportion of the total automobile derived from these materials—dashboard, steering wheel, seat padding and covering etc.—now exceeding 40%.So it is quite apparent even from a brief look at the chemical industry’s contribution to meeting our major needs that life in the world would be very different without the products of the industry. Indeed the level of a country’s development may be judged by the production level and sophistication of its chemical industry4. Research and Development (R&D) in Chemical IndustriesOne of the main reasons for the rapid growth of the chemical industry in the developed world has been its great commitment to, and investment in research and development (R&D). A typical figure is 5% of sales income, with this figure being almost doubled for the most research intensive sector, pharmaceuticals. It is important to emphasize that we are quoting percentages here not of profits but of sales income, i.e. the total money received, which has to pay for raw materials, overheads, staff salaries, etc. as well. In the past this tremendous investment has paid off well, leading to many useful and valuable products being introduced to the market. Examplesinclude synthetic polymers like nylons and polyesters, and drugs and pesticides. Although the number of new products introduced to the market has declined significantly in recent years, and in times of recession the research department is usually one of the first to suffer cutbacks, the commitment to R&D remains at a very high level.The chemical industry is a very high technology industry which takes full advantage of the latest advances in electronics and engineering. Computers are very widely used for all sorts of applications, from automatic control of chemical plants, to molecular modeling of structures of new compounds, to the control of analytical instruments in the laboratory.Individual manufacturing plants have capacities ranging from just a few tones per year in the fine chemicals area to the real giants in the fertilizer and petrochemical sectors which range up to 500,000 tonnes. The latter requires enormous capital investment, since a single plant of this size can now cost $520 million! This, coupled with the widespread use of automatic control equipment, helps to explain why the chemical industry is capital-rather than labor-intensive.The major chemical companies are truly multinational and operate their sales and marketing activities in most of the countries of the world, and they also have manufacturing units in a number of countries. This international outlook for operations, or globalization, is a growing trend within the chemical industry, with companies expanding their activities either by erecting manufacturing units in other countries or by taking over companies which are already operating there.化学工业1.化学工业的起源尽管化学品的使用可以追溯到古代文明时代，我们所谓的现代化学工业的发展却是非常近代（才开始的）。
英文文献用翻译
Adult【成年人】Aged【老年人】Aged, 80 and over【老年人, 80以上】Catheterization, Central Venous/*instrumentation/methods【*导管插入术, 中心静脉/*仪器/方法】Cost-Benefit Analysis【费用效益分析】Equipment Design【设备设计】Equipment Failure【设备失效】Equipment Safety【设备安全性】Female【女(雌)性】Humans【人类】Infusion Pumps, Implantable/adverse effects/*economics【*输注泵, 植入型/副作用/*经济学】Male【男(雄)性】Middle Aged【中年人】Neoplasms/*drug therapy/pathology【*肿瘤/*药物疗法/病理学】Probability【概率】Prospective Studies【前瞻性研究】Risk Assessment【危险性评估】Sensitivity and Specificity【敏感性与特异性】Treatment Outcome【治疗结果】Vascular Patency【血管未闭】Venous Thrombosis/prevention & control【静脉血栓形成】Adolescent【青少年】Adult【成年人】Aged【老年人】Aged, 80 andover【老年人, 80以上】AntineoplasticAgents/*administration& dosage【*抗肿瘤药】*Catheters,Indwelling/adverseeffects/economics【*导管, 留置/副作用/经济学】Female【女(雌)性】Humans【人类】*Infusion Pumps,Implantable/adverse。
英文文献全文翻译
英文文献全文翻译全文共四篇示例，供读者参考第一篇示例：LeGuin, Ursula K. (December 18, 2002). "Dancing at the Edge of the World: Thoughts on Words, Women, Places".《世界边缘的舞蹈：关于语言、女性和地方的思考》Introduction:In "Dancing at the Edge of the World," Ursula K. LeGuin explores the intersection of language, women, and places. She writes about the power of words, the role of women in society, and the importance of our connection to the places we inhabit. Through a series of essays, LeGuin invites readers to think critically about these topics and consider how they shape our understanding of the world.Chapter 1: LanguageConclusion:第二篇示例：IntroductionEnglish literature translation is an important field in the study of language and culture. The translation of English literature involves not only the linguistic translation of words or sentences but also the transfer of cultural meaning and emotional resonance. This article will discuss the challenges and techniques of translating English literature, as well as the importance of preserving the original author's voice and style in the translated text.Challenges in translating English literature第三篇示例：Title: The Importance of Translation of Full English TextsTranslation plays a crucial role in bringing different languages and cultures together. More specifically, translating full English texts into different languages allows for access to valuable information and insights that may otherwise be inaccessible to those who do not speak English. In this article, we will explore the importance of translating full English texts and the benefits it brings.第四篇示例：Abstract: This article discusses the importance of translating English literature and the challenges translators face when putting together a full-text translation. It highlights the skills and knowledge needed to accurately convey the meaning and tone of the original text while preserving its cultural and literary nuances. Through a detailed analysis of the translation process, this article emphasizes the crucial role translators play in bridging the gap between languages and making English literature accessible to a global audience.IntroductionEnglish literature is a rich and diverse field encompassing a wide range of genres, styles, and themes. From classic works by Shakespeare and Dickens to contemporary novels by authors like J.K. Rowling and Philip Pullman, English literature offers something for everyone. However, for non-English speakers, accessing and understanding these works can be a challenge. This is where translation comes in.Translation is the process of rendering a text from one language into another, while striving to preserve the original meaning, tone, and style of the original work. Translating afull-length English text requires a deep understanding of both languages, as well as a keen awareness of the cultural andhistorical context in which the work was written. Additionally, translators must possess strong writing skills in order to convey the beauty and complexity of the original text in a new language.Challenges of Full-text TranslationTranslating a full-length English text poses several challenges for translators. One of the most significant challenges is capturing the nuances and subtleties of the original work. English literature is known for its rich and layered language, with intricate wordplay, metaphors, and symbolism that can be difficult to convey in another language. Translators must carefully consider each word and phrase in order to accurately convey the author's intended meaning.Another challenge of full-text translation is maintaining the author's unique voice and style. Each writer has a distinct way of expressing themselves, and a good translator must be able to replicate this voice in the translated text. This requires a deep understanding of the author's writing style, as well as the ability to adapt it to the conventions of the target language.Additionally, translators must be mindful of the cultural and historical context of the original work. English literature is deeply rooted in the history and traditions of the English-speaking world, and translators must be aware of these influences in orderto accurately convey the author's intended message. This requires thorough research and a nuanced understanding of the social, political, and economic factors that shaped the work.Skills and Knowledge RequiredTo successfully translate a full-length English text, translators must possess a wide range of skills and knowledge. First and foremost, translators must be fluent in both the source language (English) and the target language. This includes a strong grasp of grammar, syntax, and vocabulary in both languages, as well as an understanding of the cultural and historical context of the works being translated.Translators must also have a keen eye for detail and a meticulous approach to their work. Every word, sentence, and paragraph must be carefully considered and translated with precision in order to accurately convey the meaning of the original text. This requires strong analytical skills and a deep understanding of the nuances and complexities of language.Furthermore, translators must possess strong writing skills in order to craft a compelling and engaging translation. Translating a full-length English text is not simply a matter of substituting one word for another; it requires creativity, imagination, and a deep appreciation for the beauty of language. Translators mustbe able to capture the rhythm, cadence, and tone of the original work in their translation, while also adapting it to the conventions of the target language.ConclusionIn conclusion, translating a full-length English text is a complex and challenging task that requires a high level of skill, knowledge, and creativity. Translators must possess a deep understanding of both the source and target languages, as well as the cultural and historical context of the work being translated. Through their careful and meticulous work, translators play a crucial role in making English literature accessible to a global audience, bridging the gap between languages and cultures. By preserving the beauty and complexity of the original text in their translations, translators enrich our understanding of literature and bring the works of English authors to readers around the world.。
英文文献+翻译
Characterization of production of Paclitaxel and related Taxanes in Taxus Cuspidata Densiformis suspension cultures by LC,LC/MS, and LC/MS/MSCHAPTER THEREPLANT TISSUE CULTUREⅠ. Potential of Plant cell Culture for Taxane ProductionSeveral alternative sources of paclitaxel have been identified and are currently the subjects of considerable investigation worldwide. These include the total synthesis and biosynthesis of paclitaxel, the agriculture supply of taxoids from needles of Taxus species, hemisynthesis (the attachment of a side chain to biogenetic precursors of paclitaxel such as baccatin Ⅲ or 10-deacetylbaccatin Ⅲ), fungus production, and the production of taxoids by cell and tissue culture. This reciew will concentrate only on the latter possibility.Plant tissue culture is one approach under investigation to provide large amounts and a stable supply of this compound exhibiting antineoplastic activity. A process to produce paclitaxel or paclitaxel-like compounds in cell culture has already been parented. The development of fast growing cell lines capable of producing paclitaxel would not only solve the limitations in paclitaxel supplies presently needed for clinical use, but would also help conserve the large number of trees that need to be harvested in order to isolate it. Currently, scientists and researchers have been successful in initiating fast plant growth but with limited paclitaxel production or vice versa. Therefore, it is the objective of researchers to find a method that will promote fast plant growth and also produce a large amount of paclitaxel at the same time.Ⅱ. Factors Influencing Growth Paclitaxel ContentA.Choice of Media for GrowthGamborg's (B5) and Murashige & Skoog's (MS) media seem to be superior for callus growth compared to White's (WP) medium. The major difference between these two media is that the MS medium contains 40 mM nitrate and 20mM ammonium, compared to 25mM nitrate and 2mM ammonium. Many researchers have selected the B5 medium over the MS medium for all subsequent studies, although they achieve similar results.Gamborg's B5 media was used throughout our experiments for initiation of callus cultures and suspension cultures due to successful published results. It was supplemented with 2% sucrose, 2 g/L casein hydrolysate, 2.4 mg/L picloram, and 1.8 mg/L α-naphthalene acetic acid. Agar (8 g/L) was used for solid cultures.B. Initiation of Callus CulturesPrevious work indicated that bark explants seem to be the most useful for establishing callus. The age of the tree did not appear to affect the ability to initiate callus when comparing both young and old tree materials grown on Gamborg's B5 medium supplemented with 1-2 mg/L of 2,4-dichlorophenoxyacetic acid. Callus cultures initiated and maintained in total darkness were generally pale-yellow to light brown in color. This resulted in sufficient masses of friable callus necessary for subculture within 3-4 weeks. However, the growth rate can decline substantially following the initial subculture and result in very slow-growing, brown-colored clumps of callus. It has been presumed that these brown-colored exudates are phenolic in nature and can eventually lead to cell death. This common phenomenon is totally random and unpredictable. Once this phenomenon has been triggered, the cells could not be saved by placing them in fresh media. However, adding polyvinylpyrrolidone to the culture media can help keep the cells alive and growing. Our experience with callus initiationwas similar to those studies.Our studies have found that callus which initiated early (usually within 2 weeks ) frequently did not proliferate when subcultured and turned brown and necrotic. In contrast, calli which developed from 4 weeks to 4 months after explants were fist placed on initiation media were able to be continuously subcultured when transferred at 1-2 month intervals. The presence of the survival of callus after subsequent subculturing. The relationship between paclitaxel concentration and callus initiation, however, has not been clarified.C. Effect of SugarSucrose is the preferred carbon source for growth in plant cell cultures, although the presence of more rapidly metabolized sugar such as glucose favors fast growth. Other sugars such as lactose, galactose, glucose, and fructose also support cell growth to some extent. On the other hand, sugar alcohols such as mannitol and sorbital which are generally used to raise the sugars added play a major role in the production of paclitaxel. In general, raising the initial sugar levels lead to an increase of secondary metabolite production. High initial levels of sugar increase the osmotic potential, although the role of osmotic pressure on the synthesis of secondary metabolites is not cleat. Kim and colleagues have shown that the highest level of paclitaxel was obtained with fructosel. The optimum concentration of each sugar for paclitaxel production was found to be the same at 6% in all cases. Wickremesinhe and Arteca have provided additional support that fructose is the most effective for paclitaxel production. However, other combinations of sugars such as sucrose combined with glucose also increased paclitaxel production.The presence of extracellular invertase activity and rapid extracellular sucrose hydrolysis has been observed in many cell cultures. These reports suggest that cells secrete or possess on their surface excess amounts of invertase, which result in the hydrolysis of sucrose at a much faster rate. The hydrolysis of sucrose coupled with the rapid utilization of fructose in the medium during the latter period of cell growth. This period of increased fructose availability coincided with the faster growth phase of the cells.D. Effect of Picloram and Methyl JasmonatePicloram (4-amino-3.5.6-trichloropicolinic acid) increases growth rate while methyl jasmonate has been reported to be an effective elicitor in the production of paclitaxel and other taxanes. However, little is known about the mechanisms or pathways that stimulate these secondary metabolites.Picloram had been used by Furmanowa and co-workers and Ketchum and Gibson but no details on the effect of picloram on growth rates were given. Furmanowa and hid colleagues observed growth of callus both in the presence and absence of light. The callus grew best in the dark showing a 9.3 fold increase, whereas there was only a 2-4 fold increase in the presence of light. Without picloram, callus growth was 0.9 fold. Unfortunately,this auxin had no effect on taxane production and the high callus growth rate was very unstable.Jasmonates exhibit various morphological and physiological activities when applied exogenously to plants. They induce transcriptional activation of genes involved in the formation of secondary metabolites. Methyl jasmonate was shown to stimulate paclitaxel and cephalomannine (taxane derivative) production in callus and suspension cultures. However, taxane production was best with White's medium compared to Gamborg's B5 medium. This may be due to the reduced concentration of potassium nitrate and a lack of ammonium sulfate with White's medium.E. Effect of Copper Sulfate and Mercuric ChlorideMetal ions have shown to play significant roles in altering the expression of secondary metabolic pathways in plant cell culture. Secondary metabolites,such as furano-terpenes, have been production by treatment of sweet potato root tissue with mercuric chloride. The results for copper sulfate, however, have not been reported. F. Growth Kinetics and Paclitaxel ProductionLow yields of paclitaxel may be attributed to the kinetics of taxane production that is not fully understood. Many reports stated inconclusive results on the kinetics of taxane production. More studies are needed in order to quantitate the taxane production. According to Nett-Fetto, the maximum instantaneous rate of paclitaxel production occurred at the third week upon further incubation. The paclitaxel level either declined or was not expected to increase upon further incubation. Paclitaxel production was very sensitive to slight variations in culture conditions. Due to this sensitivity, cell maintenance conditions, especially initial cell density, length of subculture interval, and temperature must be maintained as possible.Recently, Byun and co-workers have made a very detailed study on the kinetics of cell growth and taxane production. In their investigation, it was observed that the highest cell weight occurred at day 7 after inoculation. Similarly, the maximum concentration for 10-deacetyl baccatin Ⅲ and baccatin Ⅲ were detected at days 5 and 7, respectively. This result indicated that they are metabolic intermediates of paclitaxel. However, paclitaxel's maximum concentration was detected at day 22 but gradually declined. Byun and his colleagues suggested that paxlitaxel could be a metabolic intermediate like 10-deacetyl baccatin Ⅲ and baccatin Ⅲ or that pacliltaxel could be decomposed due to cellular morphological changes or DNA degradation characteristic of cell death.Pedtchanker's group also studied the kinetics of paclitaxel production by comparing the suspension cultures in shake flasks and Wilson-type reactors where bubbled air provided agitation and mixing. It was concluded that these cultures of Taxus cuspidata produced high levels of paclitaxel within three weeks (1.1 mg/L per day ). It was also determined that both cultures of the shake flask and Wilson-type reactor produced similar paclitaxel content. However, the Wilson-type reactor had a more rapid uptake of the nutrients (i.e. sugars, phosphate, calcium, and nitrate). This was probably due to the presence of the growth ring in the Wilson reactor. Therefor, the growth rate for the cultures from the Wilson reactor was only 135 mg./L while the shake flasks grew to 310 mg/L in three weeks.In retrospect, strictly controlled culture conditions are essential to consistent production and yield. Slight alterations in media formulations can have significant effects upon the physiology of cells, thereby affecting growth and product formation. All of the manipulations that affect growth and production of plant cells must be carefully integrated and controlled in order to maintain cell viability and stability.利用LC,LC/MS和LC/MS/MS悬浮培养生产紫杉醇及邓西佛米斯红豆杉中相关紫杉醇类的特征描述第三章植物组织培养Ⅰ.利用植物细胞培养生产紫杉的可能性紫杉醇的几个备选的来源已被确定，而且目前是全球大量调查的主题。
英文文献原文及对应翻译
Adsorption char acter istics of copper , lead, zinc and cadmium ions by tourmaline(环境科学学报英文版) 电气石对铜、铅、锌、镉离子的吸附特性JIANG Kan1,*, SUN Tie-heng1,2 , SUN Li-na2, LI Hai-bo2(1. School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China. jiangkan522@; 2. Key Laboratory of Environmental Engineering of Shenyang University, Shenyang 110041, China)摘要：本文研究了电气石对Cu2+、Pb2+、Zn2+和Cd2+的吸附特性，建立了吸附平衡方程。
研究四种金属离子的吸附等温线以及朗缪尔方程。
结果表明电气石能有效地去除水溶液中的重金属且具有选择性：Pb2+> Cu2+> Cd2+> Zn2+。
电气石对金属离子吸附量随着介质中金属离子的初始浓度的增加而增加。
电气石也可以增加金属溶液的pH值；发现电气石对Cu2+、Pb2+、Zn2+和Cd2+的最大吸附量为78.86、154.08、67.25和66.67mg/g；温度在25-55℃对电气石的吸附量影响很小。
此外研究了Cu2+、Pb2+、Zn2+和Cd2+的竞争吸附。
同时观察到电气石对单一金属离子的吸附能力为Pb>Cu>Zn>Cd，在两种金属系统中抑制支配地位是Pb>Cu，Pb>Zn，Pb>Cd，Cu>Zn，Cu>Cd，和Cd>Zn。
关键字：吸附；重金属含量；朗缪尔等温线；电气石介绍重金属是来自不同行业排出的废水，如电镀，金属表面处理，纺织，蓄电池，矿山，陶瓷，玻璃。
英文文献及翻译
Geotextile reinforced by soft soil1. IntroductionGeotextile known, it has high tensile strength, durability, corrosion resistance, texture, flexibility, combined with good sand, to form reinforced composite foundation, effectively increase the shear strength , tensile properties, and enhance the integrity and continuity of soil. Strengthening mechanism for the early 60's in the 20th century, Henri Vidal on the use of triaxial tests found a small amount of fiber in the sand, the soil shear strength can improve the image of more than 4 times in recent years, China's rock Laboratory workers also proved in the reinforced sand can effectively improve the soil's bearing capacity, reduce the vertical ground settlement, effectively overcome the poor soil and continuity of overall poor performance. As with the above properties of reinforced soil and the characteristics of its low price, so the project has broad application prospects.2.1 Project OverviewThe proposed retaining wall using rubble retaining wall of gravity, the wall is 6 meters high, the bearing capacity of foundation soil required to 250kPa, while the basement geology from the top down as follows: ①clay to a thickness of 0.7 to 2 meters saturated, soft plastic; ② muddy soil, about 22 - 24 meters thick, saturated, mainly plastic flow, local soft plastic; ③ sand layer to a thickness of 5 to 10 meters, containing silty soil and organic matter, saturated, slightly wet; ④ gravel layer, the thickness of the uneven distribution points, about 0 to 2.2 meters, slightly dense; ⑤ weathered sandstone. Including clay and silty soil bearing capacity is 70kPa, obviously do foundation reinforcement.2.2 Enhanced Treatment of reinforced foundation cushion Reinforcement replacement method can be used for sand and gravel used forsoil treatment, but due to loose bedding, based on past experience, witha gravel mat to treat a large settlement of the foundation always exist, even the characteristics of poor, often resulting in cracks in the superstructure, differential settlement of the image, this works for6-meter-high rubble retaining walls, height and large, and because the walls are 3 meters high wall, if there is differential settlement of retaining walls, cracks, will result in more serious consequences and thus should be used on the cushion reinforcement through economic and technical analysis, decide on the sand and gravel stratum were reinforced hardening. Reinforcement treatment method: first the design elevation and the basement excavation to 200mm thick layer of gravel bedding, and then capped with a layer of geotextile, and then in the thick sand and gravel on the 200, after leveling with the yellow sand using roller compaction; second with loaded bags of sand and gravel laying of geotextile, the gap filled with slag, geotextile bags capped 100 thick gravel, roller compaction. Its on repeat laying geotextile → → compacted gravel, until the design thickness of the cushion, the bridge is 1 m thick cushion, a total of 4 layers of geotextile, two bags of sand.This method works fast, simple machine, investment, after years of use, that reinforce good effect, building and construction units are satisfied.3 ExperienceTo achieve the reinforced soil reinforcement effect, must be reinforced earth construction technology, construction strict quality control: 1, geotextile should increase the initial pre-stress, and its end should be a reliable anchor to play the tensile strength of geotextile, anchoring more firmly, more capacity to improve, the foundation of the stress distribution more uniform, geotextile side Ministry of fixed length by laying end to ensure the fold, the folded end wrapped sand to increase its bond strength to ensure that the use will not be pulled out duringthe period.Second, the construction process have a significant effect on the reinforcement effect, the construction should be as soon as possible so that geotextile in tension, tensile strength geotextile can be played only when the deformation, so do not allow construction of geotextile crease occurs, the earth Fabric tension leveling as much as possible. Geotextile in order to have enough by the early Dutch strain, according to the following procedure works: ① laying geotextile; ② leveled the tension at both ends; both ends of the folded package gravel and sand filling at both ends; ③ center fill sand; ④ 2 higher end of sand; ⑤ Finally, the center of sand filling. Click here to enable the construction method of forming corrugated geotextile being stretched as soon as possible, to play a role in the early loaded.Third, the construction of geotextile-reinforced cushion should the level of shop using geotextile geotextile and laying of gravel bags cushion the turn to play bag cushion integrated turn out good, flexural rigidity, and dispersion of good and peace bedding layer of the overall continuity of good advantages.4 ConclusionGeotextile reinforced by soft soil is an effective, economical, safe, reliable, simple method, but the literature describes only qualitative, experience more components, yet the lack of rigorous The theoretical formula, reliable test data to be adequate, these are yet to be theoretical workers and the general engineering and technical personnel continue to explore.土工织物加筋垫层加固软土地基1. 引言土工织物又称土工聚合物，它具有高抗拉强度，耐久性、耐腐蚀性，质地柔韧，能与砂土很好地结合，组合成加筋土复合地基，有效地提高土的抗剪强度、抗拉性能，增强土体的整体性和连续性。
英文文献翻译
外文翻译（原文）Catalytic wet peroxide oxidation of azo dye (Congo red) using modified Y zeolite as catalystAbstractThe present study explores the degradation of azo dye (Congo red) by catalytic wet peroxide oxidation using Fe exchanged commercial Y zeolite as a catalyst. The effects of various operating parameters like temperature, initial pH, hydrogen peroxide concentration and catalyst loading on the removal of dye,color and COD from an aqueous solution were studied at atmospheric pressure. The percent removals of dye, color and COD at optimum pH07, 90◦C using 0.6 ml H 2 O2/350 ml solution and 1 g/l catalyst was 97% (in 4 h), 100% (in 45 min) and 58% (in 4 h), respectively. The % dye removal has been found to be less in comparison to % color removal at all conditions, e.g. dye removal in 45 min and at above conditions was 82%, whereas the color removal was 100%. The results indicate that the Fe exchanged Y zeolite is a promising catalyst for dye removal. Fe exchanged catalyst is characterized using XRD, SEM/EDAX, surface area analyzer and FTIR. Though the dye, color and COD removals were maximum at pH02 but as the leaching of Fe from the catalyst was more in acidic pH range, pH0 7 was taken as operating pH due to almost comparable removals as of pH0 2 and no leaching of Fe ions.© 2008 Elsevier B.V. All rights reserved.1. IntroductionReactive azo dyes from textile and dyeing industries pose grave environmental problem. An estimate shows that textiles account for 14% of India’s industrial production and around 27% of its export earnings[1]. Production during 2006 registered a growth of about 3.5% at 29,500 tonnes and the textile industry accounts for the largest consumption of dyestuffs at nearly 80% [2]. The waste containing these azo dyes is non-degradable. The process of dyeing is a combination of bleaching and coloring, which generates huge quantities of wastewaters causing environmental problems. The effluents from these industries consist of large quantities of sodium, chloride, sulphate, hardness, carcinogenic dye ingredients and total dissolved solids with very high BOD and COD values over 1500 mg/l and over 5000 mg/l, respectively [3]. Various methods have been used for dye removal like adsorption, coagulation, electrocoagulation, Fenton’s reagent and combination of these processes. Though these treatment processes are efficient in dye removal, they generate adsorbed waste/sludge, etc. which further causes a secondary pollution. In wet oxidation the sludge is disposed off to a great extent by oxidizing the organic pollutant. Catalytic wet oxidation method (CWAO and CWPO) is gaining more popularity. CWPO process using H2O2, in particular has advantages like better oxidation ability thanusing oxygen,as the former is carried out at lower pressure (atmospheric pres-sure).WAO usually acts under high temperatures (200–325◦C)and pressure (50–150 bar). A comparable oxidation efficiency is obtained at a less temperature of 100–120◦C when using hydrogen peroxide as the oxi dizing agent instead of oxygen [4].WAO is capital intensive whereas WPO needs limited capital but generates little higher running costs [4].Rivas et al.[5] showed that the addition of H2O2(as a source of free radicals) enhanced wet air oxidation of phenol, a highly non-degradable substance and found that the combined addition of H2O2 and a bivalent metal (i.e. Cu, Co or Mn) enhanced the rate of phenol removal. Various oxidation catalysts have been studied for the removal of different compounds like phenol, benzoic acid, dyes, etc. by CWPO process. Catalysts like Fe2O3/CeO2and WO3/CeO2 in the removal of phenolic solution, (Al–Fe) pillared clay named FAZA in the removal of 4-hydroxy benzoic acid, mixed (Al–Fe) pillared clays in the removal of organic compounds have been used[6–8] .Removal of dyes by CWPO process is gaining importance in recent times with a large number of catalysts. Kim and Lee [9] used Cu/Al2O3 and copper plate in treatment of dye house effluents. Liu and Sun [10] removed acid orange 52, acid orange 7 and reactive black 5 using CeO2doped Fe2O3/ -Al2O3 from dye waste water. Kim and Lee [11] reported the treatment of reactive dye solutions by using Al–Cu pillared clays as catalyst.Among these catalysts, modified zeolites are preferred for improved efficiency, lower by-product formation and less severe experimental conditions (temperatures and pressures). Theimproved efficiency of the catalyst is ascribed to its structure and large surface area with the ability of forming complex compounds. Zeolites can be ion exchanged using transition metal ions like Fe,Cu, Mn and others like Ca, Ba, etc. Zeolites are negatively charged because of the substitution of Si(IV) by Al(III) in the tetrahedral accounts for a negative charge of the structure and hence the Si/Al ratio determines the properties of zeolites like ion exchange capacity [12] . These metal ions neutralizethe negative charge on zeolites and their position, size and number determine the properties of zeolite. These metal ions are fixed to the rigid zeolite framework which prevents leaching and precipitation in various reactions[13–21] .In this work, catalytic wet peroxide oxidation of Congo red azo dye using Fe exchanged Y zeolite has been presented. Effect of variables like temperature, initial pH, peroxide concentration and catalyst loading on catalytic wet peroxide oxidation were examined and the optimum conditions evaluated.2.Materials and methods2.1. ChemicalsHydrogen peroxide (30% analytical grade), manganese dioxide,sodium hydroxide pellets (AR) and hydrochloric acid were obtained from RFCL limited (Mumbai), India. Congo red was obtained from Loba Chemie Pvt. Ltd. (Mumbai) and were obtained from RFCL limited (Mumbai), India.Commercial Na–Y zeolite was obtained from Sud chemie Pvt.Ltd. (Baroda), India. Commercial catalyst was iron exchanged with excess 1 M Fe(NO3)3 at 80◦C for 6 h. The process was repeated three times and the sample was thoroughly washed with distilled water and dried in oven in air at60◦C for 10-12 h. The amount of iron exchanged was 1.53 wt% estimated by A.A.S.2.2. Apparatus and procedureThe experimental studies were carried out in a 0.5 l three-necked glass reactor equipped with a magnetic stirrer with heater and a total reflux (Fig. 13). Water containing Congo red dye was transferred to the three-necked glass reactor. Thereafter, the catalyst was added to the solution. The temperature of the reaction mixture was raised using heater to the desired value and maintained by a P.I.D. temperature controller, which was fitted in one of the necks through the thermocouple. The raising of the temperature of the reaction mixture to 90◦C from ambient took about 30 min.The total reflux prevents any loss of vapor and magnetic stirrer to agitate the mixture. Hydrogen peroxide was added, the runs were conducted at 90◦C and the samples were taken at periodic intervals. The samples after collection were raised to pH-11 by adding 0.1N NaOH (so that no further reaction takes place) and the residual hydrogen peroxide was removed by adding MnO2 which catalyzed the decomposition of peroxide to water and oxygen. The samples were allowed to settle for overnight or one day (or centrifuged) and filtered. The supernatant was tested for color and COD. After the completion of the run, the mixture was allowed to cool and settle overnight.2.3. CharacterizationThe determination of structure of the heterogeneous catalyst was done by X-ray diffractometer (Bruker AXS, Diffraktometer D8,Germany). The catalyst structure was confirm ed by using Cu Kα as a source and Ni as a filter. Goniometer speed was kept at 1cm/min and the chart speed was 1 cm/min. The range of scanning angle(2θ) was kept at 3–60◦. The intensity peaks indicate the values of2θ , where Bragg’s law is applicable. The formation of compounds was tested by comparing the XRD patternusing JCPDS files (1971).The determination of images and composition of catalyst were done by SEM/EDAX QUANTA 200 FEG. Scanning for zeolite samples was taken at various magnifications and voltage to account for the crystal structure and size. From EDAX, the composition of the elements in weight percentage and atomic percentage were obtained along with the spectra for overall compositions and particular local area compositions. BET surface area of the samples was analyzed by Micromeritics CHEMISORB 2720. The FTIR spectra of the catalyst was recorded on a FTIR Spectrometer (Thermo Nicolet, USA, Software used: NEXUS) in the 4000–480 cm−1wave number range using KBr pellets. The internal tetrahedra and external linkage of the zeolites formed are identified and confirmed by FTIR. The IR spectra data in Table 2 is taken from literature[22] .2.4. AnalysisThe amount of the dye present in the solution was analyzed by direct reading TVS 25 (A) Visible Spectrophotometer. The visible range absorbance at the characteristic wavelength of the sample at 497 nm was recorded to follow the progress of decolorization during wet peroxide oxidation.The COD of the dye solution was estimated by the Standard Dichromator Closed Reflux Method (APHA-1989) using a COD analyzer (Aqualytic, Germany). The color in Pt–Co unit was estimated using a color meter (Hanna HI93727, Hanna Instruments, Singapore) at 470 nm and the pH was measured using a Thermo Orion, USA make pH meter. The treated dye solutions were centrifuged (Model R24, Remi Instruments Pvt. Ltd., Mumbai, India) to obtain the supernatant free of solid MnO2.A.A.S (Avanta GBC, Australia) was used to find the amount of iron exchanged and leached.3. Results and discussionDue to the iron present after the exchange process, the Y peaks diminished along with the rise in Fe peaks. Similar phenomena has also been observed by Yee and Yaacob [23] who obtained zeolite iron oxide by adding NaOH and H2O2(drop wise) at 60◦C to Na–Y zeolite. XRD pattern ( Fig. 2) showed diminishing zeolite peaks along with evolution of peaks corresponding to y-Fe2O3 with increasing NaOH concentration. The IR assignments from FTIR (Fig. 3) remain satisfied even after iron exchanging. The EDAX data (Table 1) show clearly an increase in the value of Fe conc. after ion exchange of Y-zeolite. The BET surface area (Table 1) has been found to decrease from 433 to 423 m2/g after Fe exchange. SEM image is shown in Fig. 1 . Table 2 presents FTIR specifications of zeolites (common to all zeolites).The effect of temperature, initial pH, hydrogen peroxide concentration and catalyst loading on catalytic wet peroxide oxidation of azo dye Congo red were investigated in detail.Fig. 1. SEM image of Fe-exchanged Y zeolite.Fig. 2. XRD of commercial and Fe-exchanged commercial Y zeolite.BET surface area (commercial Na–Y): 433.4 m2/g.BET surface area (Fe exchanged commercial Na–Y): 423 m2/g.Table 2Zeolite IR assignments (common for all zeolites) from FTIR.3.1. Effect of temperature on dye, color and COD removalThe temperatures during the experiments were varied from50◦Cto100◦C. A maximum conversion of dye of 99.1% was observed at 100◦C in 4 h (and 97% at 90◦C). The dye rem ovals at 80◦C, 70◦C, 60◦C and 50◦C and at 4 h are 56%, 52%, 42% and 30%,respectively. Fig. 4 shows that at a particular temperature, the dye concentration gradually decreases with time. The initial red color of the dye solution decreased into brown color in due course and finally the brown color disappeared into a colorless solution. Dye concentration decreases at faster rates with temperatures for initial 30 min and thereafter it decreases from 1 h to 2 h. The initial concentrations of dye did not change after a brief contact period of dye solution with the Fe-exchanged zeolite catalyst (before CWPO)confirming that there is negligible adsorption of the dye by the catalyst.Fig. 5 shows the results obtained for color removal as a function of time and temperature. The maximum color removal (100%) is obtained at 100◦C in 30 min and also at 90◦C in 45 min. At a particular temperature, the color continuously decreases with time atFig. 3. FTIR of Fe-exchanged Y zeolite.Fig. 4. % dye removal as function of temperature.faster rate in first few minutes until a certain point ( t = 45 min) and then remaining almost unchanged. At 50◦C, the color removal is very low, whereas at 60◦C, there is a sudden shift towards its greater removal. The color removal is much higher at higher temperatures(70–100◦C).Fig. 6 depicts the results obtained for %COD removal as a function of time and temperature. A maximum COD removal of 66% was obtained at 100◦C (at 4 h) followed by 58% at 90◦C (at 4 h). Until60◦C, the rate of COD removal is less and during 70–100◦C, the rate is much faster.3.2. Effect of initial pH on dye, color and COD removalThe influence of initial pH on dye (Congo red) removal was studied at different pH (pH0 2, 4, 7, 8, 9 and 11) without any adjustment of pH during the experiments. A maximum conversion of 99% was obtained at pH0 2 followed by 97% at pH0 7. The dye removal at pH0 4, 8, 9 and 11 were 94%, 29%, 5% and 0.6%, respectively. All the runs were conducted for 4 h duration. The color of the solution is violet blue at pH0 2 (a colloidal solution) and greenish blue at pH0 4 (colloidal solution). In neutral and basic pH0(7, 8, 9 and 11) range, color of the solution did not change during treatment and was same as original solution, i.e. red color. Fe cations can leach out from zeolite structure into the solution causing secondary pollution. Leaching of Fe cations out of zeolitesFig. 5. % color removal as function of temperature.Fig. 6. %COD removal as function of temperature.Fig. 7. % color removal as function of pH0depends strongly on pH of the solution. The leaching of iron ions was enhanced at low pH values [24,25] . In order to determine dissolved Fe concentration, final pH values of the solutions were analyzed by A.A.S. At initial pH0 2 and 4, Fe detected in the solution was 7.8 ppm and 3.9 ppm, respectively. At pH0 7 and in alkaline range, there wasFig. 8. %COD removal as function of pH0.Fig. 9. % color removal as function of peroxide concentration.Fig. 10. %COD removal as function of peroxide concentration.almost no leaching. pH0 7, therefore, was chosen to be optimum pH for future experiments. The final pH values pH f after the reaction corresponding to pH0 2, 4, 6, 8, 9 and 11 were 2.1, 4.2, 7.2, 7.7 and 8.7, respectively. This show that the pH f tend to reach to neutral pH for all starting pH values.Fig. 7 presents the results obtained for color removal as a function of time and pH0. A maximum color removal of 100% was obtained at pH0 2 (in 10 min) and also at pH0 7 (in 45 min). The color removal at a particular pH0 decreases at a faster rateinitially (0–1 h) and thereafter it has a slower rate. The lowest removal was observed at pH0 11 with almost no removal.Fig. 11. % color removal as function of catalyst loading.Fig. 12. %COD removal as function of catalyst loading.The results obtained for COD removal as a function of time and pH0 are shown in Fig. 8 . A maximum COD removal of 69% was obtained at pH0 2 in 4 h followed by 63% at pH0 4 and 58% at pH0 7in4h.Fig. 8 shows maximum decrease in COD value in the initial 30 mines at all pH0. The decrease in COD is not appreciable thereafter. The COD removal is more in acidic range with a maximum removal of 69%, moderate in neutral region and least in basic region.3.3. Effect of peroxide concentration on dye, color and COD removalThe influence of H2O2 concentration on dye removal was investigated at different concentrations of hydrogen peroxide (in the range 0–6 ml). A maximum removal of 99.02% was obtained at H2O2 concentration of 3 ml per 350 ml of solution, followed by 98.3% at 1ml and 97% at 0.6 ml. The dye removal at H2O2concentrations of 6 ml,0.3 ml and 0 ml (and at 4 h) were 94%, 82% and 8%, respectively. The dye removal rate at 90◦C temperature is gradual at all conc entrations of peroxide. At peroxide concentration of 0 ml, there is very little removal of dye, hardly 8%. Hence, it can be inferred that catalytic thermolysis (a process of effluent treatment by heating the effluent with/without catalyst) is not active and cannot be applied for dye removal.At the beginning of the reaction, the OH•radicals which are produced additionally when peroxide concentration is increased,speeds up the azo dye degradation. After a particular peroxide concentration, on further increase of the peroxide, the dye removal isFig. 13. Schematic diagram of the reactor.not increased. This may be because of the presence of excess peroxide concentration, hydroperoxyl radicals (HO2•) are produced from hydroxyl radicals that are already formed. The hydroperoxyl radicals do not contribute to the oxidative degradation of the organic substrate and are much less reactive. The degradation of the organic substrate occurs only by reaction with HO•[26] .The % color removal at a particular peroxide concentration increases at a faster rate in the initial 45 min and then at slower rates afterwards (Fig. 9). As H2O2 concentration increases, the rate of removal is much faster, reaching 100% in 45 minusing 6 ml H2O2 per 350 ml solution, whereas it is 100% in 1 h for both 0.3 ml and3ml.Fig. 10 shows the results obtained for COD removal as a function of time and H2O2 concentration. The maximum COD removal, 63% is obtained for H2O2 conc. 3 ml at 90◦C, pH0 7 and 2 h duration.3.4. Effect of catalyst loading on dye, color and COD removalThe influence of catalyst concentration on dye removal was investigated at different concentrations (in the range 0.5–1.5 g/l). A maximum dye removal of 98.6% was observed at 1.5 g/l followed by 98.3% at 1 g/l and 87.3% at 0.5 g/l in 4 h duration. The % dye removal without catalyst was very low with only 36% dye removal in 4 h. By comparing the results for the dye removal without catalyst and1.5 g/l catalyst, the removal for 1.5 g/l is approximately three times to that of without catalyst. The rate of removal is also more for higher concentrations of catalyst and increases with it.Fig. 11 shows the results obtained for color removal as a function of time and catalyst concentration. The maximum color removal of 100% was obtained using 1.5 g/l catalyst conc. in 1.5 h and also using 1 g/l catalyst in 3 h.Fig. 12 presents the results obtained for %COD removal as a function of time and catalyst concentration. A maximum COD removal of 58% was obtained at catalyst conc. 1 g/l, 51.8% at 1.5 g/l and 50.5% at 0.5 g/l in 4 h. Without catalyst, the COD removal was only 35%.4. ConclusionsThe % removals of dye, color and COD by catalytic wet peroxide oxidation obtained at 100◦C, 4 h duration using 0.6 ml H2O2/350 ml solution, 1 g/l Fe–Y catalyst and pH0 7 were 99.1%, 100% (30 min)and 66%, respectively. As at 100◦C the solution has tendency to vaporize during the operation, 90◦C was taken as operating temperature. The corresponding % removals at 90◦C were 97% dy e, 100%color (in 45 min) and 58% COD. Acidic range gave higher % removals in comparison to neutral and alkaline range. At pH0 2, the dye, color and COD removals of 99%,100% (in 10 min) and 69% were observed after 4 h duration. As at pH0 2, the leaching of Fe ions from Y zeolite catalyst is predominant,pH0 7 was taken as operating pH. Fe concentration of 7.8 ppm was observed in the solution at pH0 2. The values of removals, however,are comparable to pH0 2, with dye removal of 97%, color removal of100% (in 45 min) and COD removal of 58% in 4 h.The H2O2concentration was found to be optimum at 3 ml/350 ml solution giving dye, color and COD removals of 99%,100% (in 1 h) and 63%, respectively.The study on the effect of catalyst loading revealed 1.5 g/l as best among the catalyst concentrations studied. The results with 1 g/l and 1.5 g/l catalyst concentration were almost comparable.外文翻译（译文）使用改性Y沸石为催化剂湿式催化过氧化氢氧化偶氮染料(刚果红)摘要本研究主要探讨了使用改性Y沸石固载铁离子作为催化剂湿式催化过氧化氢氧化降解偶氮染料(刚果红)。
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Determination of Arsenic in Palm Kernel Expeller using Microwave Digestion and Graphite Furnace Atomic Absorption Spectrometry Method Abdul Niefaizal Abdul Hammid, Ainie Kuntom, RazaIi Ismail, and Norazilah Pardi 1Malaysian Palm Oil Board, Persiaran Institusi, Bandar Baru Bangi, 43000,Kajang Selangor, Malaysia. niefaizal@.myAbstrak – A study on the method to determine arsenic in palm kernel expeller wascarried out. Microwave digestion technique is widely applied in the analyticalchemistry field. In comparison to conventional sample digestion method, themicrowave technique is simple, reduced contamination, usage of safe reagent andmatrix completely digested. A graphite furnace atomic absorption spectrometrymethod was used for the total determination of arsenic in palm kernel expeller.Arsenic was extracted from palm kernel expeller in a closed vessel digestion systemwith nitric acid and hydrogen peroxide. The results showed that the optimal ashingand atomizing temperatures were 800°C and 2400°C respectively. The limit ofdetection was estimated to be 0.001 ppm. The mean recoveries of arsenic forrepeatability and reproducibility for 1, 2 and 4 ppm were in the range between 79 –90%. Ten samples of palm kernel expeller from mills were analyzed to contain 0.18to 3.05 ppm of arsenic. Therefore, is proposed that this method be used to detectarsenic in palm kernel expellerKey Words –Microwave digestion, graphite furnace atomic absorptionspectrometry, palm kernel expeller, arsenic, mills.1 IntroductionArsenic has been considered as an essential trace element for normal growth and development of animals (Lasky et al, 2004). However, arsenic is more often regarded as a hazardous element rather than as essential element widely encountered in the environment and organisms (Cullen and Reimer, 1989). Arsenic is extensively distributed in the environment because of its presence naturally as well as from industrial production. Natural arsenic concentration in plants hardly exceeds 1 mg/kg (Porter and Peterson, 1975). This level increases to several folds when plants are coerced to grow in arsenic treated soils, but arsenic is primarily retained in the roots. Studies showed that vegetable grown in arsenic-spiked soils exhibited 7.1 and 5.0 mg/kg in the roots and shoots respectively Jones and Hatch, 1945). In tomato and bean plants, arsenic is primarily concentrated in the roots, and a small quantity is translocated to the pods (Cobb et al., 2000). A similar pattern is observed in Tamarik (Tamarix parviflora) and Eucalyptus (Eucalyptus camaldulensis) where the roots accumulate more arsenic compared to the shoots (Tossell et al., 2000).In Malaysia the level of arsenic in oil palm is not well established. Contamination of arsenic may come from the use of herbicides such a monosodium methyl arsenate (MSMA), disodium methyl arsenate (DSMA) and cacodylic acid (dimethylarsenic acid) in oil palm plantations. However these compounds are not in used anymore. Numerous methods are available for extracting arsenic from various matrices and analyzing total arsenic (Hudson-Edwards et al., 2004). The most common641methods for extracting total arsenic from soils and sediments involved wet ashing of sample using one or a combination of acids such as sulphuric acid, nitric acid, hydrochloric acid, boric acid, hydrogen fluoride and hydrogen peroxide. Ashing digestion can be carried out using hotplate or microwave oven (Mucci et al., 2003).During the past few decades, microwave digestion method has become widely used since they are more reproducible, more accurate and less time consuming than conventional digestion on hot plates in open crucibles and lost of analyte is minimum (Kingston and Jassie, 1988). Arsenic can be determined using the following methods: colorimetry, hydride generation system in combination with atomic absorption spectrometer (Slemer et al., 1976) and atomic fluorescence spectrometry (Chen et al., 2001). Graphite furnace atomic absorption spectrophotometer (GFAAS) is another analytical instrument used for trace element analysis. It has been widely used to determine lead in food (Chen et al., 1999), biological samples (Dabeka and McKenzie, 1992) and environmental samples (Cabrera et al., 1994).The main objective of this study was to test the effectiveness of microwave system for the digestion of palm kernel expeller and subsequently analyzing using graphite furnace atomic absorption spectrophotometer.2 Materials and Methods2.1 ReagentsAll reagents were of analytical grade unless otherwise stated. Double-distilled water (Milli Q Millipore 18.2 mΩ-cm resistivity) was used for dilution. Nitric acid (65% w/v) and hydrogen peroxide (30% w/v) were of suprapure quality (E.Merck, Darmstadt). All the plastic and glassware were cleaned by soaking in diluted nitric acid-distilled water (1+9) and were rinsed with distilled water prior to use.2.2 Arsenic Standard SolutionA standard stock solution of arsenic (1000 ppm) was purchased from BDH Laboratory Supplies.2.3 Working Standard SolutionWorking standard solution of 100 ppm and 1 ppm were prepared by diluting the standard solution with appropriate volumes of Milli Q water. Working standard for 100 ppb was prepared by adding 1 mL of1 ppm and2 mL of nitric acid.2.4 SampleAbout 0.5 g palm kernel expeller was spiked with 500 μL, 1 mL and 2 mL of 1 ppm working standard solution to produce 1 ppm, 2 ppm and 4 ppm respectively.2.5 Preparation of Standard CurveA working standard solution of 25 ppb, 50 ppb, 75 ppb and 100 ppb were prepared by diluting the 1 ppm working standard solution with appropriate volumes of Milli Q water.642 Insan Akademika Publications2.6 Analytical ProcedureMicrowave digestion procedure was applied for palm kernel expeller sample. About 0.5 g of palm kernel expeller was weighed. Then 6 mL of nitric acid (65% w/v) and 2 mL hydrogen peroxide (30% w/v) suprapure quality were added. A blank digest was carried out in the same way. The digestion conditions for the microwave system were shown in Table 1. After treatment, the contents were cooled down, then the resultant residue was dissolved in 25 mL Milli Q water for arsenic determination by graphite furnace atomic absorption spectrophotometer.2.7 ApparatusZeeman graphite furnace atomic absorption spectrophotometer AAnalyst 600 with standard transverse heated graphite atomizer (THGA) B3000641 and arsenic electrode less discharge lamp (As-EDL) were made by Perkin Elmer (Germany). Argon was used as the pure/inert gas. The instrument operating parameters are summarized in Table 2 and Table 3. For sample digestion, a Milestone Ethos MOD with Terminal 1024 closed vessel microwave digestion system with pressure and temperature controller was used.2.8 Analysis of Arsenic in Commercial Palm Kernel ExpellerTen different palm kernel expeller samples were collected from 10 different mills in Malaysia. The samples were preserved in covered polyethylene bags, tagged properly and kept in room temperature until analysis.2.9 Statistic AnalysisThe data obtained from the analysis were calculated using computer programme Microsoft Excel for Windows.Table 1: Microwave oven heating program for the decomposition of palm kernel expellerStep Time (Minute) Temperature 1 (˚C) Temperature 2 (˚C) Microwave Power(Watt)1 15 min 500 180 1002 15 min 500 180 1003 15 min 1000 200 1204 10 min 1000 200 1205 20 min 0 50 30 643644Insan Akademika PublicationsTable 2: Instrument parameters for the determination of arsenic in palm kernel expeller using graphitefurnace atomic absorption spectrophotometerParameterSettingWavelength (nm) 193.7Slit width (nm)0.7Signal measurementPeak areaLampElectrode less dischargeLamp current (mA)380Purge gas Argon Sample volume 20 μL Modifier volume5 μLTable 3: Temperature program for the determination of arsenic in palm kernel expeller by graphitefurnace atomic absorption spectrophotometerTemperature (˚C)Ramp TimeHold TimeInterna (ml/ l Flow Gas Type min)Read120 1 30 12 5 Argon800 10 30 25 0 Argon2400 0 5 5 0 Argon +25002325 0Argon* Temperature injects: 70 ˚C .3 Results and Discussion3.1Matrix ModificationMatrix modification is an essential step in the determination of easily volatile elements by graphite furnace atomic absorption spectrophotometer. The most common matrix modifiers used in arsenic determinations are palladium, palladium-magnesium nitrate and nickel nitrate.Palladium-magnesium nitrate was selected as a modifier since memory effects were observed whenthe nickel modifier was used (Bozsai et al., 1990). An interelement compound was formed between arsenic and palladium, which has a higher heat of vaporization than pure arsenic. Therefore, a higher ashing temperature can be used and the effects of interference are diminished. Magnesium nitrate behaves as an ashing aid during the thermal pretreatment step in graphite furnace determinations. Spectral interferences caused by aluminum and phosphate are possible at the primary resonance line (193.7 nm) of arsenic. It should be possible to almost eliminate these interferences with the Zeeman background correction technique (Bettinelli et al., 1989; Welz et al., 1988; Riley, 1982).Characteristic mass for arsenic is quite high, and therefore a rather large absolute mass of arsenic should be injected into a graphite tube in order to obtain a reasonable sensitivity. This means that a645P e a k A r e ahigher sample volume should be used or that a preconcentration step is necessary. However, with a larger sample volume, a longer sample drying phase is needed, and there is also a maximum sample volume that can be dispensed onto a platform.Therefore, a sample volume of 20 mL was selected for routine use. With very low arsenic concentrations, two or more sample dispensing-drying steps can be used in order to increase the absolute amount of arsenic in the graphite furnace. One should remember that this will also increase the amount of matrix introduced into the furnace. About 5 mL of modifier solution was injected onto a sample. Larger volumes of modifier had produced wider and flatter absorption signals, therefore 5 mL of modifier was determined to be the optimal volume in arsenic determinations.3.2Method PerformanceEvaluation of quality parameters such as the linearity, recovery percentage (repeatability, and reproducibility) and limits of detection are essential to assess the method performance (Zanella et al., 2000). Calibration curve was obtained by analyzing three times each, four different solutions of known concentrations of analyte included between 25 and 100 ppb. The curve equation y = bx + m calculated with linear regression method to determine samples concentration was utilized.The calibration curve data for standard arsenic is shown in Table 4 . The equation of the curve and the R2 value (0.999) shows the good linearity of the analytical method and the method is feasible to be used. Values of coefficients of variation are less than 5% for all concentration (25 ppb, 50 ppb, 75 ppb, and 100 ppb) and to be considered acceptable.Table 4: Parameters values obtained from the calibration curveConcentration of ArsenicStandard (ppb)Average Value(ppb)Mean of AreasStandard Deviation Coefficient of Variation (%)2526.14 0.0412 0.0003 0.715051.25 0.0807 0.0020 2.447573.96 0.1165 0.0036 3.0910099.830.15730.00120.74y = 0.0016x R² = 0.9994Concentration (ppb)International Journal of Basic and Applied Science V ol. 01, No. 03, Jan 2013, pp. 641-649 Millersmtih, et. al.Fig.1: Calibration curve for the determination of arsenic by means of thegraphite furnace atomic absorption spectrophotometer techniqueThe limit of quantification (LOQ) was stated as a concentration below which the method could not operate with an acceptable level of precision and trueness. The limit of detection (LOD) was the lowest concentration of arsenic in palm kernel expeller samples that was detectable but not necessarily quantified, distinguished from zero (signal/noise >3). These limits were established based on the mean recovery and relative standard deviation results obtained for the replicates of spiked samples. Limit of detection was found to be 0.001 ppm, limit of quantification was 0.006 ppm.Recovery test for repeatability and reproducibility were performed by spiking several concentrationsof arsenic standard to palm kernel expeller, which was then analyzed using the established method. Recoveries for repeatability from palm kernel expeller at 1, 2, and 4 ppm were found to be 80.40 ±4.55%, 90.59 ±4.74%, and 85.15 ±5.06%, respectively . Recoveries for reproducibility from palm kernel expeller at 1, 2, and 4 ppm were found to be 79.20 ± 3.18%, 89.10 ± 3.11%, and 80.35 ±6.25%, respectively .All recoveries were greater than 80% with coefficient of variation less than 10% and to be considered acceptable. The results obtained show that the established method is capable of yielding a satisfactory recovery.4 ConclusionThe microwave digestion method studied is suitable for the decomposition of palm kernel expeller, since good recoveries for arsenic were obtained. Digesting palm kernel expeller with microwave digester has the advantages of time-saving and more complete digestion. In addition, the graphite furnace atomic absorption spectrometry has high sensitivity and it only takes few minutes for the time taken to complete an analysis of an individual sample. The method described herein coupled microwave digester and graphite furnace atomic absorption spectrometry, which demonstrated featuresof a rapid, safe and accurate analysis of arsenic in palm kernel expeller. The arsenic contents in palmkernel expeller from mills analyzed by the present study were minimum all below the maximal permissible standard of 4 ppm for animal feed.ReferencesBettinelli, M., U. Baroni and N. Pastorelli. (1989). Microwave oven sample dissolution for the analysis of environmental and biological materials, Analytica Chimica Acta., 225, pp. 159-174. Bozsai, G., G. Schlemmer and Z. Grobenski. (1990). Determination of arsenic, cadmium, lead and selenium in highly mineralized waters by graphite-furnace atomic absorption spectrometry,Talanta, 37(6), pp. 545-53.Cabrera, C., C. Gallego, M. C. Lopez and M. L. Lorenzo. (1994). Determination levels of lead contamination in food and feed crops. J. AOAC Int., 77, pp. 1249-1252.Chen, S. S., B. Y. Lee, C. C. Cheng and S. S. Chou. (2001). Determination of arsenic in edible fats and oils by focused microwave digestion and atomic fluorescence spectrometer, J. Food Drug Anal.,9, pp. 121-125.Chen, S. S., C. M. Chen, C. C. Cheng and S. S. Chou. (1999). Determining of copper in edible oils by direct graphite furnace atomic absorption spectrometry, J. Food Drug Anal., 7, pp. 207-214. Cobb, G. P. K., M. Sands, M. Waters, G. Wixson and E. Dorward-King. (2000). Accumulation of heavy vegetables grown in mine wastes, Environ. Toxicol. Chem., 19, pp. 600-607.Cullen, W. R. and K. J. Reimer. (1989). Arsenic speciation in the environment, Chem. Rev., 89, pp.713-764.Dabeka, R. W. and A. D. McKenzie. (1992). Graphite furnace atomic absorption spectrometric determination and survey of total aluminum, copper, manganese, molybdenum and tin in infantformulas and evaporated milk, J. AOAC Int., 75, pp. 954-963.646 Insan Akademika Publications 647Hammid, et. al.International Journal of Basic and Applied ScienceV ol. 01, No. 03, Jan 2013, pp. 641-649EU Commission Directive 2003/100 (amending Annexe 1 to Directive2002/32/EC), effective from 19 November 2004. Maximum arsenic levels in farmed animal and fish feed.Hudson-Edwards, K. A., S. L. Houghton & A. Osborn. (2004). Extraction and analysis of arsenic insoils and sediments, Trends in Analytical Chemistry, 23, pp. 745-752.Jones, J. S. and M. S. Hatch. (1945). Spray residues and crop assimilation of arsenic and lead, SoilSci ., 60, pp. 277-288.Kingston, H. M. and L. B. Jassie. (1988). Introduction to microwave sample preparation. AmericanChemical Society, Washington, DC, USA.Lasky, T., W. Sun, A. Kadry, and M. K. Hoffman. (2004). Mean total arsenic concentrations in chicken1998-2000 and estimated exposures for consumers of chicken, Environ. Health Perspect , 112, pp. 18-21.Mucci, A., B. Boudreau and C. Guignard. (2003). Digenetic mobility to trace elements in sedimentscovered by flash flood deposit: Mn, Fe, and As, Applied Geochemistry , 118, pp. 1011-1026.Porter, K. K. and P. J. Peterson. (1975). Arsenic accumulation by plants on mine wastes (UnitedKingdom), Sci. Total Env ., 4, pp. 365-37.Riley, K. W. (1982). Spectral interferences by Al on the determination of As using the graphitefurnace: choice of resonance lines, At. Spectrom., 3, pp. 120–131.International Journal of Basic and Applied ScienceMillersmtih, et. al. V ol. 01, No. 03, Jan 2013, pp. 641-649Slemer, D. D., P. Koteel and V. Jarlwala. (1976). Optimization of arsine generation in atomic absorption arsenic determination, Anal. Chem., 48,pp. 836.Tossell, R. W., K. Binard and T. Rafferty. (2000). Uptake of arsenic by Tamarisk and Eucalyptus under saline conditions. Battelle Press, Columbus, Richmond, pp: 485-492.Welz, B., G. Schlemmer and J. R. Mudakavi. (1988). Palladium nitrate–magnesium nitrate modifier for graphite-furnace atomic-absorption spectrometry: Determination of arsenic, cadmium, copper, manganese, lead, antimony, selenium and thallium in water, Journal of Analytical Atomic Spectrometry, 3(5), pp. 695–701.Zanella, R., E. G. Primel, F. F. Goncalves and A. F. Martins. (2000). Development and validation of a high performance liquid chromatographic method for the determination of clomazone residues in surface water, J. Chromatogr. A., 904(2), pp. 257–262.648 Insan Akademika Publications。