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Production Technology (production + technology)
Selected AbstractsPRODUCTION TECHNOLOGY OF ROMAN LEAD-GLAZED POTTERY AND ITS CONTINUANCE INTO LATE ANTIQUITYARCHAEOMETRY, Issue 5 2010M. S. WALTON A broad selection of Roman lead-glazed pottery dating from the first century ad through the fifth century ad was studied to establish locations of workshops and to address their technology of production. The ceramic bodies were analysed by ICP,AES. In addition, lead isotope analysis was undertaken on a selection of glazes. These findings suggested that there were several regions responsible for the production of lead-glazed ceramics in the western Roman world, including central Gaul, Italy and, probably, Serbia and Romania. Using the body compositions as a starting point, the glazing techniques employed by each of the potential workshops were examined using electron probe microanalysis. It was determined that there were two primary methods of glazing. The first method used lead oxide by itself applied to non-calcareous clay bodies, and the second method used a lead oxide-plus-quartz mixture applied to calcareous clay bodies. Based on these data for clay composition and glazing method, transfer of technology from the Hellenistic east to the western Roman world was proposed. Likewise, the inheritance of lead-glazing technology into late antiquity was established by making comparisons to lead-glazed ceramics dating to the seventh to ninth centuries from Italy, the Byzantine world and Tang Dynasty China. [source] Natural Endowments, Production Technologies and the Quality of Wines in Bordeaux.THE ECONOMIC JOURNAL, Issue 529 2008Does Terroir Matter? We study whether quality assessments made by wine experts and by consumers (based on prices obtained at auction between 1980 and 1992) can be explained by variables describing endowments (land characteristics, exposures of vineyards) and technologies (from grape varieties and picking, to bottled wines). However, since technological choices are likely to depend on endowments, the effects can only be identified using an instrumental variables approach. We show that technological choices affect quality much more than natural endowments, the effect of which is negligible. [source] Estimating the Technology of Cognitive and Noncognitive Skill FormationECONOMETRICA, Issue 3 2010Flavio Cunha This paper formulates and estimates multistage production functions for children's cognitive and noncognitive skills. Skills are determined by parental environments and investments at different stages of childhood. We estimate the elasticity of substitution between investments in one period and stocks of skills in that period to assess the benefits of early investment in children compared to later remediation. We establish nonparametric identification of a general class of production technologies based on nonlinear factor models with endogenous inputs. A by-product of our approach is a framework for evaluating childhood and schooling interventions that does not rely on arbitrarily scaled test scores as outputs and recognizes the differential effects of the same bundle of skills in different tasks. Using the estimated technology, we determine optimal targeting of interventions to children with different parental and personal birth endowments. Substitutability decreases in later stages of the life cycle in the production of cognitive skills. It is roughly constant across stages of the life cycle in the production of noncognitive skills. This finding has important implications for the design of policies that target the disadvantaged. For most configurations of disadvantage it is optimal to invest relatively more in the early stages of childhood than in later stages. [source] Optimization and Control of Industrial Microbial Cultivation ProcessesENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 2 2006M. Jenzsch Abstract Compared to the immense achievements in fundamental molecular biological sciences, the improvements in the fermentation and downstream processing technologies used in industry have been less spectacular over the last decade. Hence, there is a misbalance between new cellular systems and production technologies, resulting in a decreasing annual rate of approved production processes. In its PAT initiative the U.S. Food and Drug Administration identifies the potential for continuous improvement and makes concrete suggestions how this can be achieved. Here, some of these suggestions were applied to recombinant protein production with Escherichia coli and Pichia pastoris cultures. Concretely, the development of process operational procedures is discussed that allow a more tight supervision of the processes and the automatic control in cases where processes deviate from their set-point profiles. [source] Ownership and Production Costs: Choosing between Public Production and Contracting-Out in the Case of Swedish Refuse CollectionFISCAL STUDIES, Issue 4 2003Henry Ohlsson Abstract Many comparisons of public and private firms use a public/private ownership dummy variable to capture cost differences. If, however, public and private firms use different production technologies, the dummy-variable approach is misspecified. Data from public and private firms should not be pooled. Secondly, selectivity bias may arise, making it more difficult to identify cost differentials that actually exist. Thirdly, if data should be pooled, the resulting empirical model may be logically inconsistent. This paper compares public and private firms using the refuse collection costs of 170 firms in 115 Swedish municipalities. First, public production costs were 6 per cent lower than private production costs. Secondly, cost differences did not affect producer choice. It is crucial to adjust for selectivity. Data for private and public firms should not be pooled. The dummy-variable model is misspecified. [source] Time preference and two-country tradeINTERNATIONAL JOURNAL OF ECONOMIC THEORY, Issue 1 2008Been-Lon Chen F11; E20; H20 We present a dynamic two-country model of international trade with endogenous time preference. We show that if the two countries have similar preferences, production technologies and labor endowments, there exists a unique and stable steady state such that both consumption and investment goods are produced in both countries. Unlike the case of constant time preferences, the steady state is independent of the initial international distribution of capital. We prove a dynamic Heckscher,Ohlin theorem such that the labor-abundant country exports the labor-intensive good. [source] Production externalities and local dynamics in discrete-time multi-sector growth models with general production technologiesINTERNATIONAL JOURNAL OF ECONOMIC THEORY, Issue 4 2005Kazuo Nishimura D90; O41 The present paper examines the dynamic properties of discrete-time, multi-sector growth models in the presence of sector-specific externalities. It extends the literature by allowing for multiple capital good sectors with general social constant returns production technologies. We establish conditions for the steady-state equilibrium to be locally determinate or locally indeterminate, depending crucially on the ratios of the social to private marginal products and the number of capital good sectors. We show that when the ratios of the social to private marginal products are uniform across all sectors, the steady state is always locally determinate in a two-sector model, although local indeterminacy might still arise when the economy features more than two sectors. [source] The role of policy instruments for promoting combined heat and power production with low CO2 emissions in district heating systemsINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 6 2005Å. Marbe Abstract Policy instruments clearly influence the choice of production technologies and fuels in large energy systems, including district heating networks. Current Swedish policy instruments aim at promoting the use of biofuel in district heating systems, and at promoting electric power generation from renewable energy sources. However, there is increasing pressure to harmonize energy policy instruments within the EU. In addition, natural gas based combined cycle technology has emerged as the technology of choice in the power generation sector in the EU. This study aims at exploring the role of policy instruments for promoting the use of low CO2 emissions fuels in high performance combined heat and power systems in the district heating sector. The paper presents the results of a case study for a Swedish district heating network where new large size natural gas combined cycle (NGCC) combined heat and power (CHP) is being built. Given the aim of current Swedish energy policy, it is assumed that it could be of interest in the future to integrate a biofuel gasifier to the CHP plant and co-fire the gasified biofuel in the gas turbine unit, thereby reducing usage of fossil fuel. The goals of the study are to evaluate which policy instruments promote construction of the planned NGCC CHP unit, the technical performance of an integrated biofuelled pressurized gasifier with or without dryer on plant site, and which combination of policy instruments promote integration of a biofuel gasifier to the planned CHP unit. The power plant simulation program GateCycle was used for plant performance evaluation. The results show that current Swedish energy policy instruments favour investing in the NGCC CHP unit. The corresponding cost of electricity (COE) from the NGCC CHP unit is estimated at 253 SEK MWh,1, which is lower than the reference power price of 284 SEK MWh,1. Investing in the NGCC CHP unit is also shown to be attractive if a CO2 trading system is implemented. If the value of tradable emission permits (TEP) in such as system is 250 SEK tonne,1, COE is 353 SEK MWh,1 compared to the reference power price of 384 SEK MWh,1. It is possible to integrate a pressurized biofuel gasifier to the NGCC CHP plant without any major re-design of the combined cycle provided that the maximum degree of co-firing is limited to 27,38% (energy basis) product gas, depending on the design of the gasifier system. There are many parameters that affect the economic performance of an integrated biofuel gasifier for product gas co-firing of a NGCC CHP plant. The premium value of the co-generated renewable electricity and the value of TEPs are very important parameters. Assuming a future CO2 trading system with a TEP value of 250 SEK tonne,1 and a premium value of renewable electricity of 200 SEK MWh,1 COE from a CHP plant with an integrated biofuelled gasifier could be 336 SEK MWh,1, which is lower than both the reference market electric power price and COE for the plant operating on natural gas alone. Copyright © 2005 John Wiley & Sons, Ltd. [source] Volatile composition and proteolysis in traditionally produced mature Kashar cheeseINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 7 2009Ali Adnan Hayaloglu Summary Twelve samples of raw milk mature Kashar cheese at different stages of ripening were collected from retail outlets. The average pH, moisture, fat-in-dry matter, protein, salt-in-dry matter and titratable acidity contents of the samples were 5.33, 39.39%, 45.20%, 27.33%, 6.62% and 0.65% (as lactic acid), respectively. Indices of proteolysis varied from 10.72% to 23.75% and 7.09% to 12.26% for pH 4.6-soluble and 12% trichloroacetic acid-soluble nitrogen fractions, respectively, and total free amino acid concentrations ranged from 6.36 to 36.03 mg Leu g,1 of cheese. The cheeses were analysed for volatile compounds by Solid Phase Microextraction and Gas Chromatography-Mass Spectrometry (GC-MS). A total of 113 compounds were detected and identified belonging to the following chemical groups: acids (eleven), esters (sixteen), ketones (sixteen), aldehydes (six), alcohols (twenty-seven), sulphur compounds (seven), terpenes (seven) and miscellaneous compounds (twenty-three). The potential effect of each compound on the flavour profile of Kashar cheese is discussed. Acids, esters, ketones and alcohols were found at considerable levels in the samples. Kashar cheeses obtained from different retail outlets displayed some differences in terms of chemical composition, proteolysis and patterns of aroma compounds; and may be attributed to their production technologies and age-related variations. [source] Technology choice under changing peanut policiesAGRICULTURAL ECONOMICS, Issue 1 2005T. Jeffrey Price Marketing quotas; Price supports; Real option value; Technology adoption Abstract The effect of marketing quotas and price supports on technology adoption are examined for peanut production in the southeastern United States using a real options model of investment with output price and yield uncertainty. The optimal choice of peanut production technology (dryland versus irrigated) in the southeast is shown to depend on price supports and how they change. The manner in which price supports change will have an effect on the choice and rates of abandonment or adoption of production technologies. [source] Evaluation of Reduced Fish Meal Diets for Second Year Growout of the Largemouth Bass, Micropterus salmoidesJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 6 2009Nathan J. Cochran Development of efficient cost-effective diets is a critical component in the refinement of production technologies for the largemouth bass, Micropterus salmoides (LMB). One of the first steps in reducing feed costs can be to decrease the amount of fish meal in the diet. The objective of this study was to evaluate reduced levels of fish meal, and a least-cost formulation diet, for second year growout of LMB under practical pond conditions. Twelve 0.04-ha ponds were stocked with juvenile LMB (210.1±3.3 g) at a stocking density of 8650 fish/ha (350 fish/pond). Each pond was randomly assigned one of the four dietary treatments with three replicate ponds per treatment. The three experimental diets contained varying levels of fish meal. Diets FM-45, FM-24, and FM-8 contained 45, 23.5, and 8% fish meal, respectively. In diets FM-24 and FM-8, fish meal was replaced by varying levels of poultry by-product meal, soybean meal, and blood meal. The fourth diet was a commercial salmonid diet widely used as a LMB growout feed (Nelson and Sons, Inc., SilvercupTM, Steelhead, Murray, UT, USA). This diet served as a commercial control (CC) and contained 46% crude protein. The experimental diets were formulated to be isonitrogenous and isocaloric with the CC diet and were fed once daily to apparent satiation for 180 d. At harvest, there were no significant differences between treatments (P > 0.05) in terms of survival, which averaged 95% overall. Mean weights of fish fed the three experimental diets FM-45, FM-24 and FM-8 were not significantly different (P > 0.05) and averaged 518, 546, and 529 g, respectively, but were all significantly greater (P, 0.05) than those fed the CC (488 g). Feed conversion ratio (FCR) of fish fed the FM-45 and FM-8 diets (1.43 and 1.46, respectively) was significantly greater (P, 0.05) than those fed the FM-24 diet (1.34). The FCR of fish fed the CC diet (1.39) was not significantly different (P > 0.05) from fish fed other diets. Feed cost per unit of weight gain ($US/kg) was significantly lower (P, 0.05) in fish fed the FM-24 and FM-8 diets ($0.73 and $0.72/kg, respectively) than in fish fed other diets. Feed cost per unit gain of fish fed the FM-45 diet ($0.83/kg) was significantly lower (P, 0.05) than those fed the CC diet ($1.04/kg). There were no significant differences (P > 0.05) in dress-out percentages or proximate composition among fish fed the four diets. This study indicates that fish meal levels in feeds used for the second year growout of LMB can be reduced to,8% of the formulation without reducing survival or growth and without negatively impacting body composition. [source] Cultivation of low-temperature (15°C), anaerobic, wastewater treatment granulesLETTERS IN APPLIED MICROBIOLOGY, Issue 4 2009J. O'Reilly Abstract Aims:, Anaerobic sludge granules underpin high-rate waste-to-energy bioreactors. Granulation is a microbiological phenomenon involving the self-immobilization of several trophic groups. Low-temperature anaerobic digestion of wastes is of intense interest because of the economic advantages of unheated bioenergy production technologies. However, low-temperature granulation of anaerobic sludge has not yet been demonstrated. The aims of this study were to (i) investigate the feasibility of anaerobic sludge granulation in cold (15°C) bioreactors and (ii) observe the development of methanogenic activity and microbial community structure in developing cold granules. Methods and Results:, One mesophilic (R1; 37°C) and two low-temperature (R2 and R3, 15°C) laboratory-scale, expanded granular sludge bed bioreactors were seeded with crushed (diameter <0·4 mm) granules and were fed a glucose-based wastewater for 194 days. Bioreactor performance was assessed by chemical oxygen demand removal, biogas production, granule growth and temporal methanogenic activity. Granulation was observed in R2 and R3 (up to 33% of the sludge). Elevated hydrogenotrophic methanogenesis was observed in psychrophilically cultivated biomass, but acetoclastic methanogenic activity was also retained. Denaturing gradient gel electrophoresis of archaeal 16S rRNA gene fragments indicated that a distinct community was associated with developing and mature granules in the low-temperature (LT) bioreactors. Conclusions:, Granulation was observed at 15°C in anaerobic bioreactors and was associated with H2/CO2 -mediated methanogenesis and distinct community structure development. Significance and Impact of the Study:, Granulation underpins high-rate anaerobic waste treatment bioreactors. Most LT bioreactor trials have employed mesophilic seed sludge, and granulation <20°C was not previously documented. [source] Polyolefin: changing supply-demand framework and new technologyMACROMOLECULAR SYMPOSIA, Issue 1 2003Kissho Kitano Abstract Polyolefin industry is now under a remarkable change of international supply-demand framework and its market is splitting into commodity and high performance products. It is getting more important for a material being harmless and comfortable, while the "life cycle cost", which includes the cost during use and the recycle cost after use, is regarded as more important to evaluate a material. Those changes are accelerating the inter-material penetration. Several examples of the material design and production technologies, which responded to the changing market needs and developed new applications of polyolefin, are discussed. [source] Barnacle culture: background, potential and challengesAQUACULTURE RESEARCH, Issue 10 2010Daniel A. López Abstract There are approximately a dozen species of commercially interesting barnacles worldwide, some of which have been cultured on a semi-industrial scale. These species are listed and information is provided with regard to geographical distribution, landings and prices. Traditionally, ,goose' barnacles (four species) are considered to be the most important for consumption. World production already stands at 500 tonnes year,1, but this species has not been cultured to date. Some ,acorn' barnacles are also consumed (seven species), with harvest levels per species that do not exceed 200 tonnes year,1 and selling prices that can reach US$17/kg. ,Acorn' barnacle culture on a world scale is still developing. Nevertheless, production has occurred on a semi-industrial scale; specifically, spat have been collected from the wild and grown in suspended systems. Farming trials have focused on two species of acorn barnacles: Austromegabalanus psittacus (Molina 1782) ,picoroco' in Chile and Megabalanus azoricus (Pilsbry 1916) ,craca' in Portugal. The large-scale production of these crustaceans will depend on the optimization of spat collection from the wild and/or the parallel development of mass production technologies for larvae (hatcheries). In addition, further development will be achieved by opening up new markets for commercialization. [source] Sources of Growth and Structural Change in the Vietnamese Economy, 1996,2003: A Computable General Equilibrium Analysis,ASIAN ECONOMIC JOURNAL, Issue 2 2009James A. Giesecke C68; D58; F14; O12 We use the MONASH-VN model, a dynamic computable general equilibrium model of the Vietnamese economy, to investigate Vietnam's rapid growth and structural change over the period 1996 to 2003. We do this in two steps. First, we estimate changes in variables representing production technologies, consumer preferences, government policy and other structural features of the economy. Movements in these structural and policy variables are then used to explain the recent history of Vietnam's rapid growth and structural change. We find the most important sources of growth and change to be technical improvements, favorable shifts in foreign demand for Vietnamese goods and employment growth. Other important factors include movement in household preferences away from primary products and towards manufactures and services, expansion in agricultural land supply, and tax reform. [source] Impact of research investment on Cassava production technologies in India,AUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 3 2009Tavva Srinivas The present study was an ex-post assessment done to validate past funding on cassava research, based on economic surplus approach. Though cassava was introduced as a food crop in Kerala, India from Brazil, it has changed its status to commercial crop at present in Tamil Nadu and Andhra Pradesh states. This was made possible due to intensive research and development efforts of different R&D organizations. Cassava technologies developed enabled in sustaining the crop in the country with the world's highest productivity. All the cassava production technologies considered in the study resulted in an economic surplus of Rs.3585.87 million in the target domain covering Kerala, Tamil Nadu and Andhra Pradesh. Consumers and producers benefited to the tune of Rs.2090.64 million and Rs.1495.23 million respectively. Net present value of economic gains was estimated to be Rs.3548.76 million. Present value of research investment on cassava production technologies was Rs.37.11 million resulting in benefit cost ratio of 96.63:1 with a high internal rate of return of 104 per cent. Thus the study indicated that the research investments incurred on cassava production technologies development was highly economical and provided evidence to the policy makers that supporting the research investment on underground, under exploited tropical root crops like cassava is an economically viable proposition. [source] Organizational Form and Expense Preference: Spanish ExperienceBULLETIN OF ECONOMIC RESEARCH, Issue 2 2002Iftekhar Hasan This article investigates the effect of alternative ownership structures, stock versus mutual, on the cost of production of Spanish depository institutions. By introducing a stochastic frontier analysis in estimating the best,practiced expense,preference behaviour, the empirical approach adjusts for the possibility that the two sectors of the banking industry employ different production technologies and finds evidence that is consistent with expense,preference behaviour by the mutual savings banks. [source] End-of-pipe or cleaner production?BUSINESS STRATEGY AND THE ENVIRONMENT, Issue 8 2007An empirical comparison of environmental innovation decisions across OECD countries Abstract While both fundamental types of abatement measure mitigate the adverse environmental impacts of production, cleaner production technologies are frequently more advantageous than end-of-pipe technologies for environmental and economic reasons. This paper analyzes a variety of factors that might enhance firms' propensity to implement cleaner production technologies instead of end-of-pipe technologies. On the basis of a unique facility-level data set derived from a recent OECD survey, we find a clear dominance of cleaner production in seven OECD countries: 76.8% of the facilities report that they invest predominantly in cleaner production technologies, above all in new production processes, but not so much in new products. Based on a discrete choice model, our estimation results indicate that regulatory measures and the stringency of environmental policies are more important for end-of-pipe technologies, while cost savings, general management systems and specific environmental management tools tend to favor clean production. We conclude that improvements towards cleaner production may be reached by the continuous development and wider diffusion of these management tools. Improvements may also be stimulated by widening the cost gap between the two types of technology, for instance by additionally charging for waste and energy use. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment. [source] Landscape Clubs: Co-existence of Genetically Modified and Organic CropsCANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 2 2007W. H. Furtan The possibility of increased production of genetically modified (GM) crops in agriculture accentuates the need to examine the feasibility of GM and non-GM technologies co-existing on a common physical landscape. Using the theory of clubs, this paper examines the possibility of co-existence for GM and organic wheat technologies through the formation of an organic club with an endogenously determined buffer zone. Given the available data on prices, and yields, it is shown that a club can be created in which GM and organic agricultural production technologies can economically co-exist in the same physical landscape. Specifically, co-existence results in an increase in economic welfare over a situation where only GM technology is used but is not Pareto superior because producers in the buffer zone will incur injury. We show that organic producers in the club can compensate producers in the buffer zone and still be better off. Hence, the compensation principle holds. La possibilité de production accrue de cultures génétiquement modifiées (GM) accentue la nécessité d'examiner la faisabilité de coexistence des technologies GM et non GM dans un même paysage agricole. À l'aide de la théorie des clubs, le présent article a examiné la possibilité de coexistence des technologies de culture de blé GM et de blé biologique en créant un club ,biologique, comprenant une zone tampon déterminée de façon endogène. Compte tenu des données disponibles concernant les prix et les rendements, il est montré qu'il est possible de créer un club au sein duquel les technologies de production de cultures biologiques et GM peuvent économiquement coexister dans un même paysage naturel. Spécifiquement, la coexistence engendre une augmentation du bien-être économique par rapport à une situation où seule la technologie GM est utilisée, mais elle n'est pas Pareto supérieure parce que les producteurs dans la zone tampon subiront des dommages. Nous montrons que les producteurs de cultures biologiques membres du club peuvent indemniser les producteurs de la zone tampon tout en demeurant en bonne position. Le principe de compensation tient donc. [source] Managing People to Promote InnovationCREATIVITY AND INNOVATION MANAGEMENT, Issue 2 2005Helen Shipton There is growing evidence available to suggest that Human Resource Management (HRM) practice is an important predictor of organizational performance. Drawing upon organizational learning perspectives, we argue that HRM systems also have the potential to promote organizational innovation. We present longitudinal data from thirty-five UK manufacturing organizations to suggest that effective HRM systems , incorporating sophisticated approaches to recruitment and selection, induction, appraisal and training , predict organizational innovation in products and production technology. We further show that organizational innovation is enhanced where there is a supportive learning climate, and inhibited (for innovation in production processes) where there is a link between appraisal and remuneration. [source] A Model-Based Method for an Online Diagnostic Knowledge-Based SystemEXPERT SYSTEMS, Issue 3 2001Chrissanthi Angeli Fault diagnosis is very important for modern production technology and has received increasing theoretical and practical attention during the last few years. This paper presents a model-based diagnostic method for industrial systems. An online, real-time, deep knowledge based fault detection system has been developed by combining different development environments and tools. The system diagnoses, predicts and compensates faults by coupling symbolic and numerical data in a new environment suitable for the interaction of different sources of knowledge and has been successfully implemented and tested on a real hydraulic system. [source] The long and winding road from the research laboratory to industrial applications of lactic acid bacteriaFEMS MICROBIOLOGY REVIEWS, Issue 3 2005Martin Bastian Pedersen Abstract Research innovations are constantly occurring in universities, research institutions and industrial research laboratories. These are reported in the scientific literature and presented to the scientific community in various congresses and symposia as well as through direct contacts and collaborations. Conversion of these research results to industrially useful innovations is, however, considerably more complex than generally appreciated. The long and winding road from the research laboratory to industrial applications will be illustrated with two recent examples from Chr. Hansen A/S: the implementation in industrial scale of a new production technology based on respiration by Lactococcus lactis and the introduction to the market of L. lactis strains constructed using recombinant DNA technology. [source] Potential of biomass-fired combined heat and power plants considering the spatial distribution of biomass supply and heat demandINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 11 2010Johannes Schmidt Abstract Combined heat and power (CHP) plants fired by forest wood can significantly contribute to attaining the target of increasing the share of renewable energy production. However, the spatial distribution of biomass supply and of heat demand limits the potentials of CHP production. This article assesses CHP potentials using a mixed integer programming model that optimizes locations of bioenergy plants. Investment costs of district heating infrastructure are modeled as a function of heat demand densities, which can differ substantially. Gasification of biomass in a combined cycle process is assumed as production technology. Some model parameters have a broad range according to a literature review. Monte-Carlo simulations have therefore been performed to account for model parameter uncertainty in our analysis. The model is applied to assess CHP potentials in Austria. Optimal locations of plants are clustered around big cities in the east of the country. At current power prices, biomass-based CHP production allows producing around 3% of the total energy demand in Austria. Yet, the heat utilization decreases when CHP production increases due to limited heat demand that is suitable for district heating. Production potentials are most sensitive to biomass costs and power prices. Copyright © 2009 John Wiley & Sons, Ltd. [source] The Solow model with CES technology: nonlinearities and parameter heterogeneityJOURNAL OF APPLIED ECONOMETRICS, Issue 2 2004Winford H. Masanjala This paper examines whether nonlinearities in the aggregate production function can explain parameter heterogeneity in the Solow growth regressions. Nonlinearities in the production technology are introduced by replacing the commonly used Cobb,Douglas (CD) aggregated production specification with the more general Constant-Elasticity-of-Substitution (CES) specification. We first justify our choice of production function by showing that cross-country regressions favour the CES over the CD technology. Then, by using an endogenous threshold methodology we show that the Solow model with CES technology is consistent with the existence of multiple regimes. Copyright © 2004 John Wiley & Sons, Ltd. [source] Interconversion of intra- and extra-chromosomal sites of gene amplification by modulation of gene expression and DNA methylationJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2007Noriaki Shimizu Abstract We previously showed that plasmids containing a mammalian replication initiation region and a matrix attachment region were efficiently amplified to few thousand copies per cell, and that they formed extrachromosomal double minutes (DMs) or chromosomal homogeneously staining regions (HSRs). In these structures, the plasmid sequence was arranged as a tandem repeats, and we suggested a mechanism of plasmid amplification. Since amplification was very efficient, easy, and convenient, it might be adapted to a novel method for protein production. In the current study, we found that gene expression from the tandem plasmid repeat was suppressed. We identified several strategies to overcome this suppression, including: (1) use of higher concentrations of antibiotic during cell selection; (2) treatment of cells with agents that influence DNA methylation (5-azacytidine) or histone acetylation (butyrate); (3) co-amplification of an insulator sequence; and (4) co-amplification of sequences that encode a transcriptional activator. Expression from the plasmid repeat was always higher at DMs compared to HSRs. We found that continuous activation of a plasmid-encoded inducible promoter prevented the generation of long HSRs, and favored amplification at DMs. Consistent with this finding, there was a synergistic effect of transcriptional activation and inhibition of DNA methylation on the fragmentation of long HSRs and the generation of DMs and short HSRs. Our results indicate that both transcriptional activation and DNA methylation regulate the interconversion between extra- and intra-chromosomal gene amplification. These results have important implications for both protein production technology, and the generation of chromosomal abnormalities found in human cancer cells. J. Cell. Biochem. 102: 515,529, 2007. © 2007 Wiley-Liss, Inc. [source] The Role of Biotechnology in Modern Food ProductionJOURNAL OF FOOD SCIENCE, Issue 3 2004CHERL-HO LEE ABSTRACT: Modern food production technology is given great challenges by the emerging fields of biotechnology and molecular biology. Knowledge of conventional fermentation technology is upgraded by the gene level explanations of enzyme actions and physiological functions of biomaterials derived therefrom. The use of genetically modified organisms (GMOs) and their products in food widens the availability of resources while also raising public interest about safety and labeling. As an example of the application of molecular biology in conventional fermentation technology the selection of proteases from a Bacillus species grown in Korean traditional soybean fermentation starter, Meju, and the production of peptides with blood cholesterol lowering effect, obtained from soybean protein hydrolysate, are presented. Recent developments in the Korean bioindustry are reviewed as an example of the role of biotechnology in the food industry. The present status of GMO enzymes in food production is reviewed and safety issues about GMO use in the food system are discussed. [source] Technology choice under changing peanut policiesAGRICULTURAL ECONOMICS, Issue 1 2005T. Jeffrey Price Marketing quotas; Price supports; Real option value; Technology adoption Abstract The effect of marketing quotas and price supports on technology adoption are examined for peanut production in the southeastern United States using a real options model of investment with output price and yield uncertainty. The optimal choice of peanut production technology (dryland versus irrigated) in the southeast is shown to depend on price supports and how they change. The manner in which price supports change will have an effect on the choice and rates of abandonment or adoption of production technologies. [source] US,Mexico fresh vegetable trade: the effects of trade liberalization and economic growthAGRICULTURAL ECONOMICS, Issue 1 2001Jaime E. Málaga NAFTA; Vegetables; Trade liberalization; Mexico Abstract Studies of US-Mexico vegetable trade have generally emphasized the importance of US tariffs in determining the competitive advantage of US producers. Even so, research has identified at least four factors related primarily to the different levels of economic development in the US and Mexico that also have important effects on US-Mexico agricultural trade in general and fresh vegetable trade in particular. These include the differential growth rates of US and Mexican real wages, production technology (yields), and per capita income as well as cyclical movements in the real Mexican Peso/US Dollar exchange rate. This study examines the relative contribution of NAFTA and the development-related factors to likely future changes in US fresh vegetable imports from Mexico. The analysis employs an econometric simulation model of US and Mexican markets for five fresh vegetables (tomatoes, cucumbers, squash, bell peppers, and onions) accounting for 80% of US fresh vegetable imports. The results suggest that the 1994,1995 Peso devaluation rather than NAFTA was primarily responsible for the sharp increase in US imports of Mexican vegetables observed in the first years following the implementation of NAFTA. Over time, however, the results suggest that differences in the growth rates of US and Mexican production yields and, to a lesser extent, of US and Mexican real incomes and/or real wage rates could plausibly contribute more to the future growth of US tomato, squash, and onion imports from Mexico than the trade liberalizing effects of NAFTA. [source] Efficiency in an Economy with Fixed CostsJOURNAL OF PUBLIC ECONOMIC THEORY, Issue 2 2001Andrea Dall'olio It is by now well known that in an economy with increasing returns, first-best efficiency may be impossible to attain through an equilibrium concept based on market prices, even if firms are regulated to follow marginal cost pricing. We examine the efficiency issue in a special but important class of economies in which the only source of nonconvexities is the presence of fixed costs. Even in this context, it is possible that none of the equilibria based on marginal cost pricing are efficient (unless additional, strong assumptions are made). We argue that available results on the existence of an efficient two-part tariff equilibrium rely on very strong assumptions, and we provide a positive result using a weak surplus condition. Our approach can also be used to establish the existence of an efficient marginal cost pricing equilibrium with endogenously chosen lump-sum taxes if the initial endowment is efficient in the economy without the production technology. [source] Technological Scanning by Small Canadian ManufacturersJOURNAL OF SMALL BUSINESS MANAGEMENT, Issue 2 2001Louis Raymond Given that in many industries new production and information technologies have fundamentally changed the way in which firms must operate and compete, the technological aspect of environmental scanning has become a critical success factor for many small and medium-sized manufacturing enterprises. As little is presently known about how technological scanning manifests itself in these organizations and about what determines the nature and level of this activity, a survey study of 324 Canadian firms was done. Testing a research model resulted in identifying four interrelated dimensions of scanning activity, namely scanning objectives, type of information, information sources, and management practices. Key determinants of this activity were also identified, including the firms' strategy, environmental uncertainty, production technology, level of R&D, information networks, and the owner-manager's education level. [source] | ||||||||||||||||||||||||||||||||||||||||||||||