221 research outputs found

    PROTECTING CONTRACT GROWERS OF BROILER CHICKEN INDUSTRY

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    In case of the tournament based pay-structure, the regulator may be able to increase the welfare of the growers regulating the average performance standard upward. Since she cares about the welfare of the growers, her optimal is to leave part of the surplus to the growers. She does this through setting the relative standard at all others' average inflated by some function of the weight. If there is budgetary constraint then the regulator may not be able to implement this inflated standard.Livestock Production/Industries,

    OPTIMAL CONTRACTS FOR EXPLORATION WITH COST RECOVERY OF AN EXHAUSTIBLE NATURAL RESOURCE UNDER ASYMMETRIC INFORMATION

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    Exploration of an exhaustible resource with cost recovery under asymmetric information about cost is modeled and analyzed employing Principal-Agent theory. Allocation of lower than full information level of effort for the high-cost firms is found socially optimal. However, distortion is less in a two-stage process of exploration and extraction.Resource /Energy Economics and Policy,

    ENVIRONMENTAL RISK MANAGEMENT IN THE HORTICULTURAL INDUSTRY

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    This paper uses environmental risk assessment as a nutrient management planning tool to determine the best set of actions to control nutrient nonpoint source pollution in the horticultural industry. The framework minimizes costs subject to obtaining an environmental risk management score at or below a threshold value.Crop Production/Industries, Environmental Economics and Policy,

    CFD Simulation of Chemical Looping Combustion System

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    Emerging technologies for greenhouse-gas mitigation have assumed growing importance due to the imminent threat of climate change. The American Clean Energy Security Act and the American Power Act project that about 30% of fossil-fuel-based electricity generation to come from power plants with carbon capture and sequestration (CCS) by 2040, rising to approximately 59% by 2050. Chemical looping combustion (CLC) is one of the most promising cost-effective technologies that can be retrofitted onto existing power plants for CCS. The main drawback attributed to CLC is a very low confidence level as a consequence of the lack of maturity of the technology. Use of computational fluid dynamics (CFD) has the potential to boost the development and implementation of commercial-scale CLC units. This dissertation focuses on designing a novel semi-batch CLC unit using fluidized-bed reactors and modeling the hydrodynamics of fluidized bed reactors with use of CFD. The National Energy Technology Laboratory’s (NETL, USA) open-source code MFIX is used in this study as flow solver for CFD models.In this dissertation, a conceptual design is developed that leads to fabrication of a 100-kWth semi-batch CLC prototype unit by ZERE Energy and Biofuels, Inc. San Jose, California. The hydrodynamics of the prototype unit are extensively studied using mathematical modeling and CFD. A multi-stage numerical model has been developed to investigate the behavior of a fuel reactor used in CLC unit. To predict the behavior of mass transfer in the CLC reactor, a combination of perturbation theory and semi-empirical correlation is suggested. Much of the work presented in this dissertation is focused on improving the ability to use CFD for process development. The grid size used in numerical simulations should be sufficiently small so that the meso-scale structures prevailing in the gas-fluidized beds can be captured explicitly. This restricts CFD in studying industrial-scale fluidized bed reactors. Thus, a generalized grid size that is sufficient to obtain a grid-independent solution of two-fluid CFD model is suggested in this study. In order to fully understand the complex interaction between fluid phases of CFD models, a 3-D face-masking algorithm is developed and applied to assist post-processing CFD results for identification and tracking of gas bubbles in a fluidized bed. Finally, the hydrodynamics of multiphase flow reactor at high-temperature is investigated through the particle-particle restitution coefficient in numerical simulations. In conclusion, findings of this dissertation will be useful for scale-up, design, or process optimization for reliable commercial CLC plants reducing economic risk, and potentially allowing for rapid scale-up

    Effects of sodium sulfate and sodium chloride for sonochemical degradation on1,4-benzoquinone and hydroquinone in aqueous solution

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    1,4-benzoquinone, with the molecular formula C6H4O2, is generally known as a para-quinone. It is a six-member ring compound with an oxidized derivative known as 1,4-hydroquinone, which is a bright yellow crystal that has an irritating odour. On the other hand, hydroquinone, also known as benzene-1,4-diol, has the chemical formula C6H4(OH)2. It looks like a white granular solid. Quinone is generally used as a precursor to hydroquinone. The skeletal muscle relaxant, ganglion blocking agent, benzoquinonium, is made from benzoquinone. It is utilized to suppress double-bond migrations during olefin metathesis reactions. 1,4-benzoquinone is also used in the synthesis of Bromodol, while hydroquinone is the main ingredient in black-and-white photographic developers such as film and paper developers, where it diminishes the silver halide to elemental silver. There are various other uses related to this diminishing power. As a polymerization inhibitor, hydroquinone prevents the polymerization of methyl methacrylate, acrylic acid, etc. Studies have demonstrated the various effects of Na2SO4 and NaCl on the sonochemical degradation of 1,4-benzoquinone and hydroquinone using a 200-kHz sonicator. The highest degradation rate was obtained in the presence of 0.433 M Na2SO4 for 1,4-benzoquinone. After 30 minutes of ultrasonic irradiation, the total concentration of 1,4-benzoquinone decreased to 99% in the presence 0.433 M Na2SO4. Without Na2SO4, the sonochemical degradation rate of 1,4-benzoquinone was 4.5 times higher than that of hydroquinone, whereas in the presence of 0.433 M Na2SO4 under the same conditions the initial reaction rate of 1,4-benzoquinone was increased to become 10.6 times higher than that of hydroquinone. On the other hand, in the presence of NaCl, no effects were observed for the decomposition of hydroquinone but negative effects were clearly observed for the decomposition of 1,4-benzoquinone

    Awareness of herbal products among students at local university in Malaysia

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    Purpose: Herbal medicines are the most common type of traditional and complementary medicines (T & CM). T & CM have been used to diagnose and prevent diseases, restore the body’s function, and maintain or improve health. Malaysia has different ethnic groups with different beliefs and cultures. For the three dominant races, Malay, Chinese and Indian, traditional and herbal medicines are a long-standing practice. Hence, there is a common perception that the use of herbal products is better than the commercially available pharmaceutical drugs, which are deemed to contain harmful chemicals and have adverse side effects. This study aims to determine consumer’s usage of herbal products and the respondent’s perception of these product’s safety and efficacy. Method: A cross-sectional survey was performed using a self-administered questionnaire on a sample of 377 from different ethnic groups. Chi-square, Mann Whitney, Kruskal Wallis and Spearman correlation were applied for data analysis. Result: This study found significant differences in perception among the respondents from different ethnic backgrounds. Of 300 herbal product (np) users, Chinese (n=210) respondents are likely to consume natural products compare to Malay (n=54), ‘Others’ (n=34) and Indian (n=32). Malay respondents have a higher perception towards the safety of the products while Chinese respondents that herbal products might have lower nutritional value. Lastly, Indian respondents perceive that it is safer to consume natural products after consulting physicians and disagree that herbal products are more effective than conventional medicines. Conclusion: This study’s findings could help policymakers and health service providers to understand the pattern of herbal product consumption among Malaysians

    Bioanalytical technique: a quality check for pharmaceutical dosage forms

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    Quality, safety and efficacy these are the endeavours required to be addressed meticulously for any drug development process. World regulatory agencies are repeatedly and continuously reminding the pharmaceutical manufacturer to abide by these three major requirements for any dosage form preparation either new drug entity or imitated generic drug. Bioavailability of drugs at target sights considered as a major indicator of the quality and efficacy of any therapeutic agent. Bioavailability of drug is often evaluated by bioequivalence (BE) of the drug with the reference drugs or already tested drugs. Bioanalysis of drug substances plays a critical role to determine the effectiveness of the bioequivalence results. In Malaysia, the regulatory agency responsible for overseeing the approval of drugs and ensuring their quality, safety, and efficacy is the National Pharmaceutical Regulatory Agency (NPRA). Bioequivalence result is important for the evaluation of generic drugs and NPRA follows the guidelines set by the World Health Organization (WHO) for determining bioequivalence. Thus, bioanalytical techniques become the key quality checking tool for the determination of the quality and efficacy of any drug dosage forms. At IIUM, we strive towards the excellence of quality manufacturing of drug dosage forms through its PICS GMP compliant manufacturing plant IKOP Sdn Bhd. NPRA requires that generic drugs demonstrate bioequivalence to their reference listed drug before they can be approved for sale and use in Malaysia. To comply with the NPRA requirement we have developed several bioanalytical assay for different classes of drugs such as antihypertensive, antidiabetic, NSAID, antihistamin etc. Different HPLC and LCMS technique was adopted to develop and validate bioanalytical technique for the determination of drugs in human plasma or serum. Design of experiment was used to optimise the extraction technique for a better sample preparation. USFDA, EMA, ICH and ASEAN BE guideline was followed for the development and validation of the bioanalytical techniques

    METHODOLOGY FOR THE ALTERATION OF HAZARDOUS SOLVENTS IN DRUG SYNTHESIS

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    Hazardous solvents have a high potential for causing acute health risks, including serious health problems such as cancer. They should be avoided or limited in pharmaceutical and chemical synthesis owing to the health hazards and safety issues. A method of amide coupling reaction was developed employing the recommended solvents to replace the hazardous solvents. The reactions were observed using the RP-HPLC method to detect reaction rate of aniline and benzoic acid to produce N-phenyl benzamide. 68.33%, 79.25% and 89.81% yields were synthesized using the solvents: acetone (Ace), dimethyl sulfoxide (DMSO), and ethanol (EtOH) respectively while 87.60% was produced by hazardous solvent: N, N-dimethyl formamide (DMF). Using this approach, adjusting the pH10 of the organic solvent increases reaction yield up to 34.67%, 4.65%, and 3.84% for Ace, DMSO, and EtOH, respectively. In drug synthesis, the proposed method can be applied in wide range to get the protection from the risks of hazardous solvents. The method can be anticipated in future to be an exciting basic method in synthetic chemistry

    Gains from Contracting for US Hog Growers

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    Vertical coordination through contracts between farmers and other stages of the agro food chain have been of growing importance in US agriculture. Production contract arrangements between contractors and individual growers have been one of the major vehicles of this emerging system of vertical coordination. Despite the unprecedented success of production contracts as claimed by many through risk reduction, income stabilization, use of improved managerial inputs, and know-how transfer from contractors to growers, contract growers dissatisfied with existing contract payments complain that contractors are extracting too much of contract benefits while growers gain only small, or even negative, returns from contract production. Thus, measuring growers' gains from contracting, and understanding what determines the returns to contracting, is important for evaluating the policy issues associated with contracting in agriculture. This study examines hog growers' gains from contracting and explores the distribution of the gains from contracting among contract hog growers. The purpose of this dissertation is threefold. The first purpose is to review the major issues that have been examined in the literature on principal-agent theory, with special attention to the issues that are important in the agricultural sector in general and hog production in particular. Some further extensions of the basic theories are developed to enable solving the empirical puzzles. Some implications for agents' gains from contracting in both static and dynamic settings are derived. Related discussion shows how hog contracts relate to standard principal-agent theories. The main finding is that for the most plausible information structure, that is, when growers have partial but better knowledge of their ability than contractors, some low ability growers with below average productivity receive negative gains from contracting on average. This conclusion holds even when renegotiation-proof long-term contracts are in place for each ability distribution. In contrast, none of the growers receives negative gains from contracting when they have complete knowledge of their ability before signing the contract. The second purpose is an explicit theoretical modeling of hog contracts to theoretically analyze optimal incentive structures for hog contracts. A principal-agent model allowing reservation profit to vary with ability is developed to explore whether some contract growers receive negative gains from contracting on average. The results of this theoretical development suggest a rich set of alternative conditions where negative average gains from contracting are possible for growers with below average productivity of any particular ability level discernible by the contractor. These losses are likely to be repeated under long-term contracting when ability is a permanent random draw for the grower that is different than expected. Even low-ability growers with above average productivity can experience an ex post loss from contracting. The third purpose of this dissertation is to test the main theoretical findings on contract growers' gains from contracting using revealed preference data from the well-known Agricultural Resource Management Survey (ARMS) for 2004. In order to do this, contract growers' gains from contracting are measured using standard impact evaluation methods. By going beyond typical estimation of how contracting affects average growers' profits, estimates are developed to show how high-profit growers are affected differently from low-profit growers, and whether some growers are worse off with contracting. The results are especially relevant for policy analysis regarding hog contracting because it shows what share of contract growers lose from contracting and identifies their characteristics. The impact distribution of contract growers' gains is also explored using quantile regression. The estimated growers' gains from contracting are then used to evaluate theoretical predictions of the hog model. The main empirical findings of this research can be summarized as follows. First, both risk reduction and limited credit are important motivations for hog contracting. Second, the sorting effect is positive, implying that contract growers tend (because of the effect of unobservables) to choose contracting because of a comparative advantage in doing so. A positive selection bias is estimated, which tends to give contract growers a comparative disadvantage from independent operation. Third, high ability growers earn higher profits on average than low ability growers as predicted by the hog contracting model. Fourth, the mean effect of contracting for contract growers (ATET) is positive for all contract growers. However, when contract growers are divided into quartiles by size, the ATET is positive only for the lower three quartiles whereas it is negative for the highest. Fifth, the ATET decrease over quantiles of the profit distribution for contract growers and the ATNT decreases over quantiles of the profit distribution for independent growers. Sixth, one third of the contract growers receive negative gains from contracting. Below average productivity growers lose from contracting as predicted by the hog contracting model. Seventh, the mean effect of contracting for independent growers (ATNT) is negative. Eighth, the ATET exceeds the ATNT, meaning that independent growers would gain less than contract growers had they contracted. Ninth, contract and independent growers are different with respect to the productivity of the variable factors of production but unilateral technological superiority of one group to the other is not found. Finally, the results suggest that small growers will be forced either to exit the hog business or expand operations regardless of their contracting status

    O papel da pesquisa na prevenção de transtornos mentais

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    National Institute of Mental HealthUniversidade Federal de São Paulo (UNIFESP) Department of PsychiatryUNIFESP, Department of PsychiatrySciEL
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