Studied natural compounds

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  • The compounds of La1-xCaxMnO3- δ with x=0.46 and 0.50 occupy special positions in the phase diagram of La1-xCaxMnO3-δ system due to their interesting properties and charge-ordering phase transition. The samples were prepared by a solid-state reaction method. The XPD patterns show that the samples are of a single-phase orthorhombic-perovskite structure. The chemical compositions of the samples are investigated by EDS. The concentrations of oxygen and Mn3+; Mn4+ ions have been determined by dichromate method.

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  • The crystal structure and thermoelectric properties of La(Fe1-xSix)13 compounds were investigated by means of X-ray powder diffraction and electrical resistivity, thermopower and thermal conductivity measurements. The single NaZn13-type cubic structure phase is stabilized for the compounds with x = 0.12, 0.14 and 0.15. These magnetic phase transitions are also seen in the electrical resistivity, thermopower and thermal conductivity measurements. All compounds have the small values of thermopower and lattice conductivity. ...

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  • The nature of annuities and their potential to be considered both insurance and in- vestment products complicated attempts during this study to differentiate annuities sold by insurance companies as insurance products from those annuities that qualify solely as investment products that happened to be sold by insurance companies. The SAR narratives reference annuities in the manner portrayed in Table 7.

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  • Our results generally showed that in the investigated microbial community autotrophic component was dominant over the heterotrophic component during the winter season, while dominance of heterotrophic component in the microbial community was observed during the warmer seasons. Further, within the prokaryotic community heterotrophic prokaryotes were mostly dominant throughout the studied area.

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  • Environmental Chemistry is a relatively young science. Interest in this subject, however, is growing very rapidly and, although no agreement has been reached as yet about the exact content and limits of this interdisciplinary discipline, there appears to be increasing interest in seeing environmental topics which are based on chemistry embodied in this subject. One of the first objectives of Environmental Chemistry must be the study of the environment and of natural chemical processes which occur in the environment.

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  • Tham khảo tài liệu 'medicinal plants of asia and the pacific christophe wiart, pharm.d', kỹ thuật - công nghệ, hoá học - dầu khí phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả

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  • When the price of Ginseng advanced some years ago hundreds engaged in the business who knew little or nothing of farming, plant raising and horticulture. That they largely failed is not to be wondered at. Later many began in a small way and succeeded. Many of these were farmers and gardeners. Others were men who had hunted, trapped and gathered "seng" from boyhood. They therefore knew something of the peculiarities of Ginseng. It is from the experience of these men that this work is largely made up--writings of those who are in the business.

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  • Yadav et al. (2007) studied on fertilizer industrial discharge showed that some components in the discharge may interact with each other and produce toxic to aquatic organisms. For instance, the interaction between dissolved oxygen and ammonia changed the respiratory physiology in fresh water fish. In addition, results showed that the toxicity of the effluent in fish depends on concentration and duration of exposure.

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  • The European Union has developed the draft of a “Working document on sludge” (EU 2000), to promote the use of sewage sludge in agriculture while improving the safety and harmonize quality standards. It proposes limit values for concentrations of heavy metals and organic compounds that should restrict the use of sewage sludge in agriculture if the limits are exceeded and provides suggestions for good practice in treatment and agricultural use.

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  • This analysis takes as given that improved information and accounting methods are costly. While costs will vary across different types of improved information -- and are by no means always easy to measure -- they are conceptually straightforward to define. Information's costs include the labor and capital costs necessary to acquire, apply, and verify new information. The costs may be associated with a diverse set of activities, including technical R&D, financial analysis, process engineering studies, software development, inventory controls, and supplier surveys.

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  • The objective of this thesis was to study the interactions of microbial activity, biocide usage and creation, and chemical changes in the papermaking process. The main focus was on oxidative biocide systems. In addition, new measurement and biocide production methods were applied to papermaking, and evaluated for the monitoring and control of the microbiological state and biocide usage. The measurement methods were based on portable handheld online equipments whereas the biocide production was based on electrochemical generation of biocides.

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  • This potential disparity in availability of private insurance between regions and crops is sometimes cited as a reason for government intervention (U.S. GAO, 1980; Appel, Lord, and Harrington, 1999), but here again, crop insurance is not unique. Many risk management tools used by farmers are available only in certain regions. For example, cash forward contracting is widely available for corn and soybean producers in the Midwest, although the same is not necessarily true for producers in regions where basis risk is high.

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  • Bacterial community in dioxin contaminated soil and mud samples from Danang airport was enumerated and studied for their potential degradation capability against three-ring compound carbazol. The cell number was determined on nutrient rich medium and on mineral medium supplemented with carbazol. It has been showed that number of cells presented in mud samples was significantly higher than in soil samples, in the range of 1 magnitude order. About 50% of the total cell number in each sample grown on the medium with carbazol.

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  • In June 2001, independent research firm Computer Economics released the results of a study on potential privacy problems in different industry sectors. Banking and finance organizations were determined to be the most susceptible to privacy management problems. The transportation, wholesale, and retail industries also ranked high on the privacy problem susceptibility index compiled by Computer Economics.

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  • Essential oil of Cinnamomum longepetiolatum Costerm. apud Phamh. Obtained by hydro distillation. The essential oil yield was 0.91% in fresh leaves. The chemical composition of this oil was study by GC and GC/MS. Twelve compounds were identified representing 98.8% of this oil with camphor as major constituent (87.5%). Eleven other compounds were found with lower content. The results of this study shows that Cinnamomum longepetiolatum Costerm. apud Phamh. was a new natural source of camphor in Vietnam. ...

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  • Most drugs against malaria that are available or under development target a single process of the parasite infective cycle, favouring the appearance of resistant mutants which are easily spread in areas under chemotherapeutic treatments.

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  • The cometabolism of citrate and glucose by growing Lactococcus lactisssp. lactis bv. diacetylactis was studied using a natural-abundance stable isotope technique. By a judicious choice of substrates differing slightly in their 13 C/ 12 C ratios, the simultaneous metabolism of citrate and glucose to a range of compounds was analysed. These end-products include lactate, acetate, formate, diacetyl and acetoin. All these products have pyruvate as a common intermediate.

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  • The purpose of this review is to discuss the effect of natural antioxidant compounds as modulators of the 20Sproteasome, a multi-enzymatic multi-catalytic complex present in the cytoplasm and nucleus of eukaryotic cells and involved in several cellular activities such as cell-cycle progression, pro-liferation and the degradation of oxidized and damaged proteins.

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  • As early as the middle of the 19th century, scientists were beginning to isolate and characterize organic compounds from nature. Modern studies of the nature of natural products, those compounds not involved in primary metabolic processes, began in the 1930s and 1940s. In the decades that followed, scientists began to focus on why organisms produce these compounds.

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  • The pH values will bring effects in flora and fauna nearby, change the taste of water and lead to heavy corrosion in pipe lines. High conductivity naturally indicates the presence of ionic substances dissolved in the river water. However, the result showed that 90% of the study site exceeded the data reported for non-contaminated rivers due to excessive metal ions within the water. At the site nearer to kaolin industry the conductivity is 852 times higher than the non-polluted study site. The industrial discharge also changed the hardness in river water.

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