Influence of plant traits on production costs and profitability of strawberry in southeast Queensland.

In Queensland the subtropical strawberry ( Fragaria * ananassa) breeding program aims to combine traits into novel genotypes that increase production efficiency. The contribution of individual plant traits to cost and income under subtropical Queensland conditions was investigated, with the overall goal of improving the profitability of the industry through the release of new strawberry cultivars. The study involved specifying the production and marketing system using three cultivars of strawberry that are currently widely grown annually in southeast Queensland, developing methods to assess the economic impact of changes to the system, and identifying plant traits that influence outcomes from the system. From May through September P (price; $ punnet -1), V (monthly mass; tonne of fruit on the market) and M (calendar month; i.e. May=5) were found to be related ( r2=0.92) by the function (SE) P=4.741(0.469)-0.001630(0.0005) V-0.226(0.102) M using data from 2006 to 2010 for the Brisbane central market. Both income and cost elements in the gross margin were subject to sensitivity analysis. 'Harvesting' and 'Handling/Packing' 'Groups' of 'Activities' were the major contributors to variable costs (each >20%) in the gross margin analysis. Within the 'Harvesting Group', the 'Picking Activity' contributed most (>80%) with the trait 'display of fruit' having the greatest (33%) influence on the cost of the 'Picking Activity'. Within the 'Handling/Packing Group', the 'Packing Activity' contributed 50% of costs with the traits 'fruit shape', 'fruit size variation' and 'resistance to bruising' having the greatest (12-62%) influence on the cost of the 'Packing Activity'. Non-plant items (e.g. carton purchases) made up the other 50% of the costs within the 'Handling/Packing Group'. When any of the individual traits in the 'Harvesting' and 'Handling/Packing' groups were changed by one unit (on a 1-9 scale) the gross margin changed by up to 1%. Increasing yield increased the gross margin to a maximum (15% above present) at 1320 g plant -1 (94% above present). A 10% redistribution of total yield from September to May increased the gross margin by 23%. Increasing fruit size increased gross margin: a 75% increase in fruit size (to ~30 g) produced a 22% increase in the gross margin. The modified gross margin analysis developed in this study allowed simultaneous estimation of the gross margin for the producer and gross value of the industry. These parameters sometimes move in opposite directions.

U.S. Caribbean fish trap fishery costs and earnings study

Executive Summary: This study describes the socio-economic characteristics of the U.S. Caribbean trap fishery that encompasses the Commonwealth of Puerto Rico and Territory of the U.S. Virgin Islands. In-person interviews were administered to one hundred randomly selected trap fishermen, constituting nearly 25% of the estimated population. The sample was stratified by geographic area and trap tier. The number of traps owned or fished to qualify for a given tier varied by island. In Puerto Rico, tier I consisted of fishermen who had between 1-40 fish traps, tier II was made up of fishermen who possessed between 41 and 100 fish traps, and tier III consisted of fishermen who held in excess of 100 fish traps. In St. Thomas and St. John, tier I was composed of fishermen who held between 1 and 50 fish traps, tier II consisted of fishermen who had between 51-150 fish traps and tier III was made up of fishermen who had in excess of 150 fish traps. Lastly, in St. Croix, tier I was made up of fishermen who had less than 20 fish traps and tier II consisted of fishermen who had 20 or more fish traps. The survey elicited information on household demographics, annual catch and revenue, trap usage, capital investment on vessels and equipment, fixed and variable costs, behavioral response to a hypothetical trap reduction program and the spatial distribution of traps. The study found that 79% of the sampled population was 40 years or older. The typical Crucian trap fisherman was older than their Puerto Rican and St. Thomian and St. Johnian counterparts. Crucian fishermen’s average age was 57 years whereas Puerto Rican fishermen’s average age was 51 years, and St. Thomian and St. Johnian fishermen’s average age was 48 years. As a group, St. Thomian and St. Johnian fishermen had 25 years of fishing experience, and Puerto Rican and Crucian fishermen had 30, and 29 years, respectively. Overall, 90% of the households had at least one dependent. The average number of dependents across islands was even, ranging between 2.8 in the district of St. Thomas and St. John and 3.4 in the district of St. Croix. The percentage utilization of catch for personal or family use was relatively low. Regionally, percentage use of catch for personal or family uses ranged from 2.5% in St. Croix to 3.8% in the St. Thomas and St. John. About 47% of the respondents had a high school degree. The majority of the respondents were highly dependent on commercial fishing for their household income. In St. Croix, commercial fishing made up 83% of the fishermen’s total household income, whereas in St. Thomas and St. John and Puerto Rico it contributed 74% and 68%, respectively. The contribution of fish traps to commercial fishing income ranged from 51% in the lowest trap tier in St. Thomas and St. John to 99% in the highest trap tier in St. Croix. On an island basis, the contribution of fish traps to fishing income was 75% in St. Croix, 61% in St. Thomas and St. John, and 59% in Puerto Rico. The value of fully rigged vessels ranged from $400 to $250,000. Over half of the fleet was worth $10,000 or less. The St. Thomas and St. John fleet reported the highest mean value, averaging $58,518. The Crucian and Puerto Rican fleets were considerably less valuable, averaging $19,831 and $8,652, respectively. The length of the vessels ranged from 14 to 40 feet. Fifty-nine percent of the sampled vessels were at least 23 feet in length. The average length of the St. Thomas and St. John fleet was 28 feet, whereas the fleets based in St. Croix and Puerto Rico averaged 21 feet. The engine’s propulsion ranged from 8 to 400 horsepower (hp). The mean engine power was 208 hp in St. Thomas and St. John, 108 hp in St. Croix, and 77 hp in Puerto Rico. Mechanical trap haulers and depth recorders were the most commonly used on-board equipment. About 55% of the sampled population reported owning mechanical trap haulers. In St. Thomas and St. John, 100% of the respondents had trap haulers compared to 52% in Puerto Rico and 20% in St. Croix. Forty-seven percent of the fishermen surveyed stated having depth recorders. Depth recorders were most common in the St. Thomas and St. John fleet (80%) and least common in the Puerto Rican fleet (37%). The limited presence of emergency position indication radio beacons (EPIRBS) and radar was the norm among the fish trap fleet. Only 8% of the respondents had EPIRBS and only 1% had radar. Interviewees stated that they fished between 1 and 350 fish traps. Puerto Rican respondents fished on average 39 fish traps, in contrast to St. Thomian and St. Johnian and Crucian respondents, who fished 94 and 27 fish traps, respectively. On average, Puerto Rican respondents fished 11 lobster traps, and St. Thomian and St. Johnian respondents fished 46 lobster traps. None of the Crucian respondents fished lobster traps. The number of fish traps built or purchased ranged between 0 and 175, and the number of lobster traps built or bought ranged between 0 and 200. Puerto Rican fishermen on average built or purchased 30 fish traps and 14 lobster traps, and St. Thomian and St. Johnian fishermen built or bought 30 fish traps and 11 lobster traps. Crucian fishermen built or bought 25 fish traps and no lobster traps. As a group, fish trap average life ranged between 1.3 and 5 years, and lobster traps lasted slightly longer, between 1.5 and 6 years. The study found that the chevron or arrowhead style was the most common trap design. Puerto Rican fishermen owned an average of 20 arrowhead traps. St. Thomian and St. Johnian and Crucian fishermen owned an average of 44 and 15 arrowhead fish traps, respectively. The second most popular trap design was the square trap style. Puerto Rican fishermen had an average of 9 square traps, whereas St. Thomian and St. Johnian fishermen had 33 traps and Crucian fishermen had 2 traps. Antillean Z (or S) -traps, rectangular and star traps were also used. Although Z (or S) -traps are considered the most productive trap design, fishermen prefer the smaller-sized arrowhead and square traps because they are easier and less expensive to build, and larger numbers of them can be safely deployed. The cost of a fish trap, complete with rope and buoys, varied significantly due to the wide range of construction materials utilized. On average, arrowhead traps commanded $94 in Puerto Rico, $251 in St. Thomas and St. John, and $119 in St. Croix. The number of trips per week ranged between 1 and 6. However, 72% of the respondents mentioned that they took two trips per week. On average, Puerto Rican fishermen took 2.1 trips per week, St. Thomian and St. Johnian fishermen took 1.4 trips per week, and Crucian fishermen took 2.5 trips per week. Most fishing trips started at dawn and finished early in the afternoon. Over 82% of the trips lasted 8 hours or less. On average, Puerto Rican fishermen hauled 27 fish traps per trip whereas St. Thomian and St. Johnian fishermen and Crucian fishermen hauled 68 and 26 fish traps per trip, respectively. The number of traps per string and soak time varied considerably across islands. In St. Croix, 84% of the respondents had a single trap per line, whereas in St. Thomas and St. John only 10% of the respondents had a single trap per line. Approximately, 43% of Puerto Rican fishermen used a single trap line. St. Thomian and St. Johnian fishermen soaked their traps for 6.9 days while Puerto Rican and Crucian fishermen soaked their traps for 5.7 and 3.6 days, respectively. The heterogeneity of the industry was also evidenced by the various economic surpluses generated. The survey illustrated that higher gross revenues did not necessarily translate into higher net revenues. Our analysis also showed that, on average, vessels in the trap fishery were able to cover their cash outlays, resulting in positive vessel income (i.e., financial profits). In Puerto Rico, annual financial profits ranged from $4,760 in the lowest trap tier to $32,467 in the highest tier, whereas in St. Thomas and St. John annual financial profits ranged from $3,744 in the lowest tier to $13,652 in the highest tier. In St. Croix, annual financial profits ranged between $9,229 and $15,781. The survey also showed that economic profits varied significantly across tiers. Economic profits measure residual income after deducting the remuneration required to keep the various factors of production in their existing employment. In Puerto Rico, annual economic profits ranged from ($9,339) in the lowest trap tier to $ 8,711 in the highest trap tier. In St. Thomas and St. John, annual economic profits ranged from ($7,920) in the highest tier to ($18,486) in the second highest tier. In St. Croix, annual economic profits ranged between ($7,453) to $10,674. The presence of positive financial profits and negative economic profits suggests that higher economic returns could be earned from a societal perspective by redirecting some of these scarce capital and human resources elsewhere in the economy. Furthermore, the presence of negative economic earnings is evidence that the fishery is overcapitalized and that steps need to be taken to ensure the long-run economic viability of the industry. The presence of positive financial returns provides managers with a window of opportunity to adopt policies that will strengthen the biological and economic performance of the fishery while minimizing any adverse impacts on local fishing communities. Finally, the document concludes by detailing how the costs and earnings information could be used to develop economic models that evaluate management proposals. (PDF contains 147 pages)

Analysis of transport costs for energy crops for use in biomass pyrolysis plant networks

Fast pyrolysis of biomass produces a liquid bio-oil that can be used for electricity generation. Bio-oil can be stored and transported so it is possible to decouple the pyrolysis process from the generation process. This allows each process to be separately optimised. It is necessary to have an understanding of the transport costs involved in order to carry out techno-economic assessments of combinations of remote pyrolysis plants and generation plants. Published fixed and variable costs for freight haulage have been used to calculate the transport cost for trucks running between field stores and a pyrolysis plant. It was found that the key parameter for estimating these costs was the number of round trips a day a truck could make rather than the distance covered. This zone costing approach was used to estimate the transport costs for a range of pyrolysis plants size for willow woodchips and baled miscanthus. The possibility of saving transport costs by producing bio-oil near to the field stores and transporting the bio-oil to a central plant was investigated and it was found that this would only be cost effective for large generation plants.

Interactions between a Trawl fishery and spatial closures for biodiversity conservation in the Great Barrier Reef World Heritage Area, Australia.

Background: The Queensland East Coast Otter Trawl Fishery (ECOTF) for penaeid shrimp fishes within Australia's Great Barrier Reef World Heritage Area (GBRWHA). The past decade has seen the implementation of conservation and fisheries management strategies to reduce the impact of the ECOTF on the seabed and improve biodiversity conservation. New information from electronic vessel location monitoring systems (VMS) provides an opportunity to review the interactions between the ECOTF and spatial closures for biodiversity conservation. Methodology and Results: We used fishing metrics and spatial information on the distribution of closures and modelled VMS data in a geographical information system (GIS) to assess change in effort of the trawl fishery from 2001-2009 and to quantify the exposure of 70 reef, non-reef and deep water bioregions to trawl fishing. The number of trawlers and the number of days fished almost halved between 2001 and 2009 and new spatial closures introduced in 2004 reduced the area zoned available for trawl fishing by 33%. However, we found that there was only a relatively minor change in the spatial footprint of the fishery as a result of new spatial closures. Non-reef bioregions benefited the most from new spatial closures followed by deep and reef bioregions. Conclusions/Significance: Although the catch of non target species remains an issue of concern for fisheries management, the small spatial footprint of the ECOTF relative to the size of the GBRWHA means that the impact on benthic habitats is likely to be negligible. The decline in effort as a result of fishing industry structural adjustment, increasing variable costs and business decisions of fishers is likely to continue a trend to fish only in the most productive areas. This will provide protection for most benthic habitats without any further legislative or management intervention.

The Annual Economic Survey of Federal Gulf Shrimp Permit Holders: Report on the Design, Implementation, and Descriptive Results for 2006

This technical memorandum documents the design, implementation, data preparation, and descriptive results for the 2006 Annual Economic Survey of Federal Gulf Shrimp Permit Holders. The data collection was designed by the NOAA Fisheries Southeast Fisheries Science Center Social Science Research Group to track the financial and economic status and performance by vessels holding a federal moratorium permit for harvesting shrimp in the Gulf of Mexico. A two page, self-administered mail survey collected total annual costs broken out into seven categories and auxiliary economic data. In May 2007, 580 vessels were randomly selected, stratified by state, from a preliminary population of 1,709 vessels with federal permits to shrimp in offshore waters of the Gulf of Mexico. The survey was implemented during the rest of 2007. After many reminder and verification phone calls, 509 surveys were deemed complete, for an ineligibility-adjusted response rate of 90.7%. The linking of each individual vessel’s cost data to its revenue data from a different data collection was imperfect, and hence the final number of observations used in the analyses is 484. Based on various measures and tests of validity throughout the technical memorandum, the quality of the data is high. The results are presented in a standardized table format, linking vessel characteristics and operations to simple balance sheet, cash flow, and income statements. In the text, results are discussed for the total fleet, the Gulf shrimp fleet, the active Gulf shrimp fleet, and the inactive Gulf shrimp fleet. Additional results for shrimp vessels grouped by state, by vessel characteristics, by landings volume, and by ownership structure are available in the appendices. The general conclusion of this report is that the financial and economic situation is bleak for the average vessels in most of the categories that were evaluated. With few exceptions, cash flow for the average vessel is positive while the net revenue from operations and the “profit” are negative. With negative net revenue from operations, the economic return for average shrimp vessels is less than zero. Only with the help of government payments does the average owner just about break even. In the short-term, this will discourage any new investments in the industry. The financial situation in 2006, especially if it endures over multiple years, also is economically unsustainable for the average established business. Vessels in the active and inactive Gulf shrimp fleet are, on average, 69 feet long, weigh 105 gross tons, are powered by 505 hp motor(s), and are 23 years old. Three-quarters of the vessels have steel hulls and 59% use a freezer for refrigeration. The average market value of these vessels was $175,149 in 2006, about a hundred-thousand dollars less than the average original purchase price. The outstanding loans averaged $91,955, leading to an average owner equity of $83,194. Based on the sample, 85% of the federally permitted Gulf shrimp fleet was actively shrimping in 2006. Of these 386 active Gulf shrimp vessels, just under half (46%) were owner-operated. On average, these vessels burned 52,931 gallons of fuel, landed 101,268 pounds of shrimp, and received $2.47 per pound of shrimp. Non-shrimp landings added less than 1% to cash flow, indicating that the federal Gulf shrimp fishery is very specialized. The average total cash outflow was $243,415 of which $108,775 was due to fuel expenses alone. The expenses for hired crew and captains were on average $54,866 which indicates the importance of the industry as a source of wage income. The resulting average net cash flow is $16,225 but has a large standard deviation. For the population of active Gulf shrimp vessels we can state with 95% certainty that the average net cash flow was between $9,500 and $23,000 in 2006. The median net cash flow was $11,843. Based on the income statement for active Gulf shrimp vessels, the average fixed costs accounted for just under a quarter of operating expenses (23.1%), labor costs for just over a quarter (25.3%), and the non-labor variable costs for just over half (51.6%). The fuel costs alone accounted for 42.9% of total operating expenses in 2006. It should be noted that the labor cost category in the income statement includes both the actual cash payments to hired labor and an estimate of the opportunity cost of owner-operators’ time spent as captain. The average labor contribution (as captain) of an owner-operator is estimated at about $19,800. The average net revenue from operations is negative $7,429, and is statistically different and less than zero in spite of a large standard deviation. The economic return to Gulf shrimping is negative 4%. Including non-operating activities, foremost an average government payment of $13,662, leads to an average loss before taxes of $907 for the vessel owners. The confidence interval of this value straddles zero, so we cannot reject, with 95% certainty, that the population average is zero. The average inactive Gulf shrimp vessel is generally of a smaller scale than the average active vessel. Inactive vessels are physically smaller, are valued much lower, and are less dependent on loans. Fixed costs account for nearly three quarters of the total operating expenses of $11,926, and only 6% of these vessels have hull insurance. With an average net cash flow of negative $7,537, the inactive Gulf shrimp fleet has a major liquidity problem. On average, net revenue from operations is negative $11,396, which amounts to a negative 15% economic return, and owners lose $9,381 on their vessels before taxes. To sustain such losses and especially to survive the negative cash flow, many of the owners must be subsidizing their shrimp vessels with the help of other income or wealth sources or are drawing down their equity. Active Gulf shrimp vessels in all states but Texas exhibited negative returns. The Alabama and Mississippi fleets have the highest assets (vessel values), on average, yet they generate zero cash flow and negative $32,224 net revenue from operations. Due to their high (loan) leverage ratio the negative 11% economic return is amplified into a negative 21% return on equity. In contrast, for Texas vessels, which actually have the highest leverage ratio among the states, a 1% economic return is amplified into a 13% return on equity. From a financial perspective, the average Florida and Louisiana vessels conform roughly to the overall average of the active Gulf shrimp fleet. It should be noted that these results are averages and hence hide the variation that clearly exists within all fleets and all categories. Although the financial situation for the average vessel is bleak, some vessels are profitable. (PDF contains 101 pages)

The Economics of Gasification: A Market-Based Approach

This paper deals with the economics of gasification facilities in general and IGCC power plants in particular. Regarding the prospects of these systems, passing the technological test is one thing, passing the economic test can be quite another. In this respect, traditional valuations assume constant input and/or output prices. Since this is hardly realistic, we allow for uncertainty in prices. We naturally look at the markets where many of the products involved are regularly traded. Futures markets on commodities are particularly useful for valuing uncertain future cash flows. Thus, revenues and variable costs can be assessed by means of sound financial concepts and actual market data. On the other hand, these complex systems provide a number of flexibility options (e.g., to choose among several inputs, outputs, modes of operation, etc.). Typically, flexibility contributes significantly to the overall value of real assets. Indeed, maximization of the asset value requires the optimal exercise of any flexibility option available. Yet the economic value of flexibility is elusive, the more so under (price) uncertainty. And the right choice of input fuels and/or output products is a main concern for the facility managers. As a particular application, we deal with the valuation of input flexibility. We follow the Real Options approach. In addition to economic variables, we also address technical and environmental issues such as energy efficiency, utility performance characteristics and emissions (note that carbon constraints are looming). Lastly, a brief introduction to some stochastic processes suitable for valuation purposes is provided.

Modelagem, simulação e otimização operacional de unidades de síntese de metanol

A indústria de processos químicos tem sofrido consideráveis transformações devido ao acirramento da competitividade. Importantes progressos tecnológicos têm sido atingidos através de técnicas de modelagem, simulação e otimização visando o aumento da lucratividade e melhoria contínua nos processos industriais. Neste contexto, as plantas de metanol, um dos mais importantes produtos petroquímicos, podem ser destacadas. Atualmente, a principal matéria-prima para obtenção de metanol é o gás natural. A produção do metanol é caracterizada por três etapas: geração de gás de síntese, conversão do gás de síntese em metanol (unidade de síntese ou loop de síntese) e purificação do produto na especificação requerida. Os custos fixos e variáveis da unidade de síntese são fortemente dependentes das variáveis operacionais, como temperatura, pressão, razão de reciclo e composição da carga. Desta forma, foi desenvolvido um conjunto de modelos e algoritmos computacionais para representar matematicamente unidades de síntese de metanol. O modelo apresenta operações unitárias associadas aos seguintes equipamentos: divisores de correntes, misturadores de correntes, compressores, trocadores de calor, vasos de flash e reatores. Inicialmente, foi proposto um simulador estacionário, que serviu como base para um pseudo-estacionário, o qual contempla a desativação do catalisador por sinterização térmica. Os simuladores foram criados segundo uma arquitetura seqüencial modular e empregou-se o método de substituição sucessiva para a convergência dos reciclos. O estudo envolveu dois fluxogramas típicos, um constituído por reatores adiabáticos em série, enquanto o outro constituído por um reator tipo quench. Uma análise do efeito das principais variáveis operacionais foi realizada para o reator e para o loop de síntese. Estudou-se também o efeito da desativação do catalisador ao longo do tempo. Uma ferramenta de otimização operacional foi empregada para alcançar a máxima produção manipulando as injeções de carga fria na entrada dos leitos catalíticos. Formulou-se também um problema de maximização do lucro em função da otimização de paradas da unidade para troca do catalisador. Os resultados obtidos apontam que a ferramenta desenvolvida é promissora para a compreensão e otimização da unidade objeto deste estudo

Planeamento de curto prazo de sistemas de energia solar usando técnicas de otimização robusta

Dissertação para obtenção do grau de Mestre em Engenharia Electrotécnica

The impact of changing the transportation cost structure of a food retail company

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Entwicklung und Anwendung einer Kraftwerks- und Speichereinsatzoptimierung für die Untersuchung von Energieversorgungsszenarien mit hohem Anteil erneuerbarer Energien in Deutschland

In dieser Arbeit wurde ein gemischt-ganzzahliges lineares Einsatzoptimierungsmodell für Kraftwerke und Speicher aufgebaut und für die Untersuchung der Energieversorgung Deutschlands im Jahre 2050 gemäß den Leitstudie-Szenarien 2050 A und 2050 C ([Nitsch und Andere, 2012]) verwendet, in denen erneuerbare Energien einen Anteil von über 85 % an der Stromerzeugung haben und die Wind- und Solarenergie starke Schwankungen der durch steuerbare Kraftwerke und Speicher zu deckenden residualen Stromnachfrage (Residuallast) verursachen. In Szenario 2050 A sind 67 TWh Wasserstoff, die elektrolytisch aus erneuerbarem Strom zu erzeugen sind, für den Verkehr vorgesehen. In Szenario 2050 C ist kein Wasserstoff für den Verkehr vorgesehen und die effizientere Elektromobilität hat einen Anteil von 100% am Individualverkehr. Daher wird weniger erneuerbarer Strom zur Erreichung desselben erneuerbaren Anteils im Verkehrssektor benötigt. Da desweiteren Elektrofahrzeuge Lastmanagementpotentiale bieten, weisen die Residuallasten der Szenarien eine unterschiedliche zeitliche Charakteristik und Jahressumme auf. Der Schwerpunkt der Betrachtung lag auf der Ermittlung der Auslastung und Fahrweise des in den Szenarien unterstellten ’Kraftwerks’-parks bestehend aus Kraftwerken zur reinen Stromerzeugung, Kraft-Wärme-Kopplungskraftwerken, die mit Wärmespeichern, elektrischen Heizstäben und Gas-Backupkesseln ausgestattet sind, Stromspeichern und Wärmepumpen, die durch Wärmespeicher zum Lastmanagment eingesetzt werden können. Der Fahrplan dieser Komponenten wurde auf minimale variable Gesamtkosten der Strom- und Wärmeerzeugung über einen Planungshorizont von jeweils vier Tagen hin optimiert. Das Optimierungsproblem wurde mit dem linearen Branch-and-Cut-Solver der software CPLEX gelöst. Mittels sogenannter rollierender Planung wurde durch Zusammensetzen der Planungsergebnisse für überlappende Planungsperioden der Kraftwerks- und Speichereinsatz für die kompletten Szenariojahre erhalten. Es wurde gezeigt, dass der KWK-Anteil an der Wärmelastdeckung gering ist. Dies wurde begründet durch die zeitliche Struktur der Stromresiduallast, die wärmeseitige Dimensionierung der Anlagen und die Tatsache, dass nur eine kurzfristige Speicherung von Wärme vorgesehen war. Die wärmeseitige Dimensionierung der KWK stellte eine Begrenzung des Deckungsanteils dar, da im Winter bei hoher Stromresiduallast nur wenig freie Leistung zur Beladung der Speicher zur Verfügung stand. In den Berechnungen für das Szenario 2050 A und C lag der mittlere Deckungsanteil der KWK an der Wärmenachfrage von ca. 100 TWh_th bei 40 bzw. 60 %, obwohl die Auslegung der KWK einen theoretischen Anteil von über 97 % an der Wärmelastdeckung erlaubt hätte, gäbe es die Beschränkungen durch die Stromseite nicht. Desweiteren wurde die CO2-Vermeidungswirkung der KWK-Wärmespeicher und des Lastmanagements mit Wärmepumpen untersucht. In Szenario 2050 A ergab sich keine signifikante CO2-Vermeidungswirkung der KWK-Wärmespeicher, in Szenario 2050 C hingegen ergab sich eine geringe aber signifikante CO2-Einsparung in Höhe von 1,6 % der Gesamtemissionen der Stromerzeugung und KWK-gebundenen Wärmeversorgung. Das Lastmanagement mit Wärmepumpen vermied Emissionen von 110 Tausend Tonnen CO2 (0,4 % der Gesamtemissionen) in Szenario A und 213 Tausend Tonnen in Szenario C (0,8 % der Gesamtemissionen). Es wurden darüber hinaus Betrachtungen zur Konkurrenz zwischen solarthermischer Nahwärme und KWK bei Einspeisung in dieselben Wärmenetze vorgenommen. Eine weitere Einschränkung der KWK-Erzeugung durch den Einspeisevorrang der Solarthermie wurde festgestellt. Ferner wurde eine untere Grenze von 6,5 bzw. 8,8 TWh_th für die in den Szenarien mindestens benötigte Wasserstoff-Speicherkapazität ermittelt. Die Ergebnisse dieser Arbeit legen nahe, das technisch-ökonomische Potential von Langzeitwärmespeichern für eine bessere Integration von KWK ins System zu ermitteln bzw. generell nach geeigneteren Wärmesektorszenarien zu suchen, da deutlich wurde, dass für die öffentliche Wärmeversorgung die KWK in Kombination mit Kurzzeitwärmespeicherung, Gaskesseln und elektrischen Heizern keine sehr effektive CO2 -Reduktion in den Szenarien erreicht. Es sollte dabei z.B. untersucht werden, ob ein multivalentes System aus KWK, Wärmespeichern und Wärmepumpen eine ökonomisch darstellbare Alternative sein könnte und im Anschluss eine Betrachtung der optimalen Anteile von KWK, Wärmepumpen und Solarthermie im Wärmemarkt vorgenommen werden.

On the efficiency of private and state-owned enterprises in mixed markets

We examine oligopoly models of vertical product differentiation in which producing firms face variable costs of quality development. We show that comparing to private oligopoly, mixed oligopoly – whereby state-owned enterprises (SOEs) and private firms coexist – enhances social welfare but reduces firms' profitability. We also demonstrate that Bertrand competition makes firms better off under mixed oligopoly but it makes firms worse off under private oligopoly compared with Cournot competition. These findings help to justify both the existence of SOEs and the efficiency of SOEs and private firms in mixed markets in transitional economies.

Microcrédito, emprego e renda: uma pesquisa empírica na ICC-BLUSOL/SC

Esta pesquisa objetivou analisar o impacto do microcrédito junto aos microempreendedores beneficiados pela Instituição de Microcrédito ICC-Blusol de Blumenau, Santa Catarina. De um total de 5.451 clientes foram selecionados e analisados 94, os quais obtiveram microcrédito durante os 10 últimos anos. Para testar a veracidade da afirmação, utilizou-se modelo econométrico utilizando a técnica de dados em painel, através da estimação das variáveis no modelo de efeitos fixos e efeitos aleatórios. Como variável independente utilizou-se a premissa "Valor do Empréstimo" e como variáveis dependentes "Vendas", "Resultado Operacional", "Garantia Real", "Garantia Aval", "Recursos Humanos", "Custos Fixos" e "Custos Variáveis". Conclui -se que somente as variáveis "Vendas" e "Resultado Operacional" validam a afirmação de que o acesso ao microcrédito resulta em incremento de Faturamento e Renda. A criação e manutenção de empregos, embora não tenha sido comprovada na análise estatística, ficou evidente, pois a simples sobrevivência da empresa já pressupõe isto.

Aspectos econômicos da produção de bovinos de corte

O Brasil ocupa as posições de maior produtor e exportador mundial de carne bovina, com a região Centro-Oeste respondendo por 35% do abate nacional, em 2010. Entretanto, faz-se necessário valorizar o planejamento, o controle e a gestão empresarial nas propriedades produtoras, visando ao lucro na atividade. O presente estudo objetivou analisar e avaliar a viabilidade econômica da produção de bovinos de corte, em Camapuã (MS), a fim de identificar os itens relevantes aos custos da atividade. Como direcionador dos custos variáveis, no custo operacional efetivo, o suplemento mineral fornecido aos animais e a mão de obra mostraram-se relevantes para a gestão do sistema de produção, representando, aproximadamente, 71% dos custos. Com base nos resultados apresentados, pôde-se concluir que a propriedade apresenta boa lucratividade (superior a 20%). Verificou-se, ainda, com base no fluxo de caixa, taxa interna de retorno de 13,13% e capital inicial investido retornando em, aproximadamente, 7 anos, com resultados atrativos para o investimento, neste segmento agropecuário. O estudo proporcionou um parâmetro de custo para o produtor pecuarista, podendo contribuir para um melhor planejamento de atividades, em que, apesar dos altos investimentos iniciais, possivelmente, poderá reduzir seus custos, com o manejo racional no sistema produtivo, o que seria mais atrativo para o mercado, tornando mais viáveis as suas atividades de produção e comercialização do produto.

Large scale laboratory cultures of Ankistrodesmus gracilis (Reisch) Korsikov (Chlorophyta) and Diaphanosoma biergei Korinek, 1981 (Cladocera)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Metodologia experimental para avaliação de custos de produção e utilização de biodiesel: estudo de caso de quatro ésteres metílicos e óleo diesel comercial

Considerando que o Brasil detém uma vasta gama de matérias-primas para produção de biodiesel, e também que há a possibilidade de produção em pequena escala, prima-se por estudos de cunho econômico a partir de metodologias de fácil execução. O objetivo do trabalho foi demonstrar uma metodologia e sua aplicação para avaliação dos custos inseridos dentro do processo produtivo e de utilização do biodiesel. A metodologia foi aplicada a biodieseis originários de óleo de soja, girassol, frango e sebo bovino, dos quais se avaliaram economicamente os custos fixos e variáveis para conversão química dos óleos e gorduras em ésteres metílicos, em uma planta de produção experimental. Os custos de produção para cada uma das quatro citadas são distintos em função do valor inicial por litro de cada uma. Também fora avaliado o custo específico e o consumo específico de cada um dos biodieseis, a fim de determinar a diferença em relação ao óleo diesel comercial. No estudo de caso, os resultados mostraram vantagens para o óleo diesel, tanto no custo quanto no consumo. Comparando-se os biodieseis, o de sebo bovino apresentou-se com o menor custo de produção e o menor consumo.