Alguns peixes carnívoros, como o salmão e a truta, são produzidos mundialmente com rações nutricionalmente completas contendo elevados níveis de farinha e óleo de peixe em função da excelente qualidade nutricional destes ingredientes. A estagnação dos estoques pesqueiros e a demanda crescente por estes ingredientes fazem com que o custo com alimentação de peixes carnívoros seja cada vez mais elevado. Nutricionistas vêm então buscando substituir a farinha e o óleo de peixe nas dietas comerciais, sem prejudicar o desempenho dos peixes confinados. O dourado, Salminus brasiliensis, é um Characiforme ictiófago neotropical de grande porte que apresenta um grande potencial para a aquicultura: excelente qualidade de carne e boa aceitação do mercado consumidor, refletidos em elevado valor comercial, sendo ainda procurado para a pesca esportiva. Entretanto, os estudos sobre o uso da espécie em piscicultura comercial são ainda rudimentares. Os objetivos deste estudo foram avaliar o desempenho do dourado alimentado com dietas contendo a farinha de vísceras em substituição à farinha de peixe e determinar o nível máximo de substituição da farinha de peixes que permitisse a maximização do lucro. O experimento foi realizado em um sistema de recirculação de água com controle de temperatura (26,78 ± 2,21 ºC), oxigênio dissolvido (6,44 ± 1,03 mg L-1), pH (7,40 ± 0,28) e amônia total (<= 0,25 mg L-1). Juvenis de dourado (12,00 ± 0,58 g) foram distribuídos em 24 caixas de polietileno de 300 L (12 peixes por caixa) em um delineamento inteiramente casualizado (n=4), aclimatados às condições de criação e dietas por 10 dias, submetidos a jejum de 24 horas, pesados, medidos e então alimentados em duas refeições diárias por 66 dias com rações extrudadas, nutricionalmente completas (40% de proteína digestível e 4020 kcal kg-1 de energia digestível), com níveis crescentes de farinha de vísceras de aves (0, 20, 40, 60, 80, 100%) em substituição à fonte dietética de proteína, a farinha de peixe. Ao final do período experimental foi feita a biometria para cálculo das seguintes variáveis de desempenho: peso médio final, ganho de peso médio, taxa de crescimento específico, consumo de ração, taxa alimentar, sobrevivência, índice de conversão alimentar, taxa de eficiência proteica, valor produtivo da proteína, eficiência de retenção de energia e maximização do lucro. Embora as variáveis estudadas não apresentassem diferenças significativas (P>0,05), foi observada a presença de dados influentes ou atípicos, que viciaram os resultados da regressão. Para diminuir a influência destes dados na curva da regressão, foi adotado o método da regressão robusta. A análise de maximização do lucro determinou que o nível ótimo de substituição de farinha de peixe por farinha de vísceras de aves foi de 33,29 %. / Carnivorous fish such as trout and salmon are raised on complete feeds, containing large quantities of fish oil and fishmeal, the best quality feed ingredient there is. The stagnation of natural fish stocks and the increasing demand for such feedstuffs makes the cost of carnivorous fish diets increasingly high. Nutritionists are thus in search of alternative ingredients to replace fishmeal in commercial diets without hampering fish performance. The dourado, Salminus brasiliensis, is a Neotropical, large ichthyophagous Characin, highly regarded for fish farming and sport fishing alike because of its prized flesh, high acceptance and market value. However, studies on the farming and husbandry of dourado are still rudimentary. This study evaluates the performance of dourado fed diets formulated to contain increasing levels of poultry byproduct meal in replacement of fish meal and determining the maximum level of replacement of fishmeal that maximizes profit. Trial was set up in a closed loop system, controlled temperature (26.78 ± 2.21 ºC), dissolved oxygen (6.44 ± 1.03 mg L-1), pH (7.40 ± 0.28), and total ammonia (<= 0.25 mg L-1). Juvenile fish were stocked in 24 tanks (300 L, 12 fish per tank) in a completely randomized design (n=4), acclimatized to system conditions and experimental diets for 10 days, fasted for 24 hours, weighted, measured and then fed twice a day for 66 days with extruded, nutritionally complete diets (40% digestible protein and 4020 kcal kg-1 digestible energy), formulated to contain increasing levels of poultry byproduct meal (0, 20, 40, 60, 80, 100) as surrogate protein source to fish meal. At the end of feeding period, fish were measured and weighted (final average weight ) to allow determining average weight gain, specific growth rate, feed consumption, feed conversion rate, protein efficiency rate, productive value of protein, energy retention rate, survival rate and profit maximization. Performance parameters did not differ (P>0.05), so to decrease the effects of influent data, the robust regression method was used and the profit maximization analysis revealed that replacing 33.29% of dietary fishmeal by poultry byproduct meal maximizes profit in the farming of dourado.

Das Kompetenzzentrum für kommunale Infrastruktur Sachsen führte in Kooperation mit Partnerschaften Deutschland deshalb die Veranstaltung „Rechenmodell für Wirtschaftlichkeitsuntersuchungen 2.0 – Beschaffungsvarianten standardisiert vergleichen“ durch. In dem Einführungsworkshop wurde den Teilnehmern das Rechenmodell für Wirtschaftlichkeitsuntersuchungen so vorgestellt, dass sie im Anschluss einschätzen konnten, ob und wie sie das Excel-Tool für ihre Beurteilung von Infrastrukturanfragen unter Berücksichtigung normativer Vorgaben nutzen können.

Das Kompetenzzentrum für kommunale Infrastruktur Sachsen führte in Kooperation mit Partnerschaften Deutschland deshalb den zweitägigen „Anwender-Workshop zum Rechenmodell für Wirtschaftlichkeitsuntersuchungen, Version 2.0 “ durch. Den Teilnehmern wurden die großen Potenziale bei der Bewertung wirtschaftlicher Beschaffungsentscheidungen durch das Rechenmodell für Wirtschaftlichkeitsuntersuchungen praktisch erfahrbar gemacht. Die Teilnehmer lernten weiterhin einzuschätzen, wie sie das Excel-Tool für die Beurteilung von Infrastrukturanfragen unter Berücksichtigung normativer Vorgaben nutzen können. Der Workshop vermittelte den Interessenten anhand einer praktischen Übung die Einsatzmöglichkeiten, die Funktionsweise und die Eingabe- und Einstellungsalternativen des WU-Rechenmodells 2.0 und stellte die umfangreichen Dokumentationsmöglichkeiten mithilfe des Tools dar.

Germany is one of the pioneer countries in wind turbine technology. They installed many wind turbines during the last decades and are now confronted with a shortage of land suitable for new wind parks. Now, with an estimated wind turbine service life of 20 – 25 years whole wind parks are becoming obsolete and owners have to decide whether do decommission, repower or to continue the operation of their parks. The advantages of repowering as well as the bureaucratic hurdles are outlined and evaluated. This thesis deals with the repowering potential in North Rhine-Westphalia and is analysing the technical and economical possibilities of repowering. The main objectives are to identify wind turbines eligible for repowering and also to develop repowering scenarios in order to determine their techno-economic feasibility.  The designed steps of the methodology allow the census and the subsequent implementation of the results in WindPro and RETScreen.

Philosophiae Doctor - PhD / Growth rates of three commercial eucheumoids: brown Eucheuma denticulatum and green and brown Kappaphycus alvarezii were studied at three sites (Gazi Bay, Kibuyuni and Mkwiro) in southern Kenya. The study was conducted using the fixed off-bottom rope technique over a 15 month period from August 2001 to October 2002, in 4 plots (5 m x 1.5 m) set up at each site. The brown E. denticulatum had the highest mean growth rate over the entire period of 4.7% day-I compared to the green and brown K. alvarezii which were 4.3% day l and 4.2% dayl, respectively. Mean relative growth rates were highest at Gazi (5.6% dayl), and lowest in Kibuyuni (3.2% day-I) with intermediate values of 4.8% dail at Mkwiro. Increased water motion was observed to increase thallus nitrogen and hence the growth of eucheumoids. The 'ice-ice' syndrome affected both brown E. denticulatum and brown K. alvarezii but not green K. alvarezii. Mean growth was higher during the southeast monsoon (4.7% day+) than during the northeast monsoon (4.0% dayl).The carrageenan characteristics of the three morphotypes were measured for 12 months. The highest carrageenan yield was obtained for green K. alvarezii (59.1% dry wt), whereas the average carrageenan yield for brown K. alvarezii was 56.5% dry wt and 56.6% dry wt for brown E. denticulatum. The plants at Gazi (58.0% dry wt) had a slightly, though significantly, higher carrageenan yield than both those at Kibuyuni (57.1 % dry wt) and Mkwiro (57.3% dry wt). However, from a commercial point of view the differences in carrageenan yields were not meaningful. Highest gel strengths were obtained in carrageenans from green K. alvarezii (1042.1 g cm") and brown K. alvarezii (1053.7 g ern"), whereas low values of 100.8 g ern" were obtained for brown E. denticulatum. The brown E. denticulatum had carrageenan with higher viscosity (81.7 mPa.s) and sulphate content (29.1% dry wt) than both green and brown K. alvarezii. The gel viscosities of all the morphotypes were higher during the southeast monsoon (67.3 mPa.s) than during the northeast monsoon (46.3 mPa.s) and were positively correlated with gel strengths.A survey was conducted among households in the three villages, from April to September 2001 to assess their socio-economic characteristics. There were 182 household heads interviewed; about 20% were women. Fishing was the main source of livelihood for about 48% of the household members. In 2001, the average monthly income for the surveyed households was Kshs. 9904 (1 US$=75 Kshs.), with about 67% having less than Kshs. 10 000. The average prevalence of poverty among the households surveyed was 45.1% with 38.8%,54.8% and 46.7% of households in Gazi, Kibuyuni and Mkwiro villages, respectively, living below the poverty line of Kshs. 1239 per month per adult person. An economic feasibility study for growing brown E. denticulatum and brown K. alvarezii in pilot farms of 0.1 ha was conducted at Gazi and Kibuyuni. A higher yield of 793 kg dry wt was obtained for plants grown at Gazi than those at Kibuyuni (793 kg dry wt). The net income derived from E. denticulatum was estimated at Kshs. 7549 annually in a 0.1 ha seaweed farm. A higher annual income of Kshs. 49 126 was generated from K. alvarezii. The rate of return on investment in farming E. denticulatum ranged from 15 to 63%, while 122 to 380% for K. alvarezii. The pay back period was shorter for the latter (0.3 to 0.7 years) than the former (1.2 to 2.7 years).A cross-sectoral policy analysis regarding legislation and policy relevant to the introduction and development of eucheumoid cultivation in Kenya, with particular reference to Kenyan legislation was conducted. The analysis showed that there is no system of promoting or regulating mariculture, though there are fragmented regulations that are scattered among the policies, Acts and regulations of various institutions. Such regulations were not designed specifically for mariculture and as a result they do not fully address the needs of mariculture. The establishment of a national mariculture development programme in Kenya is proposed as a means to develop and manage the farming of marine resources, including seaweeds.

Every day 493 tonnes of waste containing 67% of organic material is generated in the city of El Alto in Bolivia. The majority of the waste is disposed to a landfill that is expected to reach its maximum capacity by 2015. Therefore, new waste treatment methods need to be explored. The high content of organic material in waste makes biogas technologies a potential solution for waste treatment in El Alto. These technologies can generate a renewable energy source and organic fertilizer that can provide several benefits to the city. The objective of this study is to investigate the techno-economic feasibility of a small-scale biogas plant for treating organic market waste in the city of El Alto. To this end, a multi-criteria analysis was performed to identify a suitable technology. The garage-shaped digester was selected as the most appropriate technology for the conditions of El Alto. By implementing this technology, 1.8 GWh of electricity and 2,340 tonnes of organic fertilizer can be produced annually. Furthermore, an economic analysis of two scenarios was conducted. The Net Present Value (NPV), Internal Rate of Return, Payback time, Levelized Cost of Electricity (LCOE) and sensitivity analysis were evaluated. The biogas plant resulted economically viable in both cases. However, the LCOE estimated (0.17-0.26 USD/kWh) were very high in comparison to the LCOE from natural gas in Bolivia (0.026 USD/kWh). Regarding the sensitivity analysis, several parameters were evaluated from which the compost price was the most influential on changing the NPV. The study also included the estimation of the emission savings. A total of 900 tonnes of CO2/year could be avoided for producing electricity from biogas. Moreover, social benefits could also be generated such as new job opportunities. The use of a small-scale biogas plant for treating organic market waste in the city of El Alto is a cost-effective option. Though, it is fundamental that the government support the waste-to-biogas technologies by introducing economic mechanisms and promoting awareness to ensure the markets for both, biogas and organic fertilizer.

No description available.

The Passive House as a type of energy-efficient and cost-efficiency housing, has been implemented widely around the world, and made great contribution to energy saving and environment protection. Although the Passive House requires higher investment in early stage compared to conventional houses, it has many benefits including improving indoor climate and saving energy consumption. However, the development of Passive House in China has been slow due to the lack of information regarding the extra investment and benefits. To provide a clear insight on how the extra investment and benefits of the Passive House balance each other, this study establishes an evaluation model to identify and calculate the additional costs through the life cycle of the Passive House. With the cost and benefit calculated, we can also analysis the payback period to see how many years it takes to recover the extra investment. After the model is established, we evaluated a representative Passive House in Hebei, China. The result showed that the benefits of the extra investment outweigh the additional costs, and the payback period is approximately 12 years, which is acceptable for housing projects. The evaluation model not only provides the developers and consumers a tool to understand the costs and benefits, but also illustrate the economic feasibility of Passive House in China. / Passivhuset som en typ av energieffektiva och kostnadseffektiva bostäder har implementerats i hela världen och har bidragit stort till energibesparing och miljöskydd. Även om Passive House kräver högre investeringar i ett tidigt skede jämfört med konventionella hus, har det många fördelar inklusive att förbättra inomhusklimatet och spara energiförbrukning. Utvecklingen av Passive House i Kina har dock varit långsam på grund av bristen på information om extra investeringar och fördelar. För att ge en tydlig insikt om hur de extra investeringarna och fördelarna med Passive House balanserar varandra skapar denna studie en utvärderingsmodell för att identifiera och beräkna extrakostnaderna genom passivhusets livscykel. Med beräknad kostnad och nytta kan vi också analysera återbetalningsperioden för att se hur många år det tar att återfå den extra investeringen. Efter att modellen har upprättats utvärderade vi ett representativt passivhus i Hebei, Kina. Resultatet visade att fördelarna med extrainvesteringar uppväger extrakostnaderna och återbetalningsperioden är cirka 12 år, vilket är acceptabelt för bostadsprojekt. Utvärderingsmodellen ger inte bara utvecklarna och konsumenterna ett verktyg för att förstå kostnaderna och fördelarna utan illustrerar också den ekonomiska genomförbarheten hos Passive House i Kina.

The conversion of red oak small diameter timber (SDT) into solid wood products was investigated. The objectives of this research were to 1) determine the yield of lumber, pallet and container parts, and residues from SDT and the market potential for these products; 2) determine the economic feasibility of a SDT sawmill and pallet part mill located in Southwest Virginia; 3) develop a business plan for a SDT sawmill and pallet part mill located in Southwest Virginia. The methods for this research consisted of resource, yield and economic analyses, and the development of a business model. The resource analysis indicated an ample supply of red oak SDT available in Southwest Virginia. The yield analysis used red oak SDT logs, which were manufactured into lumber, container parts and wood residues. The yield of 3" wide container parts from cants varied from 63% to 66%. The 1" nominal lumber produced was mainly 2A and 3A, 74%, and 24% was 1 common. The economic analysis utilized break even, net present value and internal rate of return analyses to determine the economic feasibility of utilizing red oak SDT. The results of the study indicated that the sawmill-only processing level scenario is not economically feasible given the specified conditions and assumptions. However, the results showed that the sawmill and pallet part mill, actual yield scenario at $35/ton delivered log cost is economically feasible. The hypothetical business model for Southwest Custom Hardwoods was economically feasible. The final net present value was calculated to be over $750,000 and the final internal rate of return was 11%. Future yield studies should weigh logs so that the yield of residues and solid wood products can be directly compared. Future research into the utilization of hardwood SDT should include yield studies of other species and other product mixes. / Master of Science

Rare Earth elements (REEs) are economically important due to their critical applications within multiple industries. This study investigates the Spruce Pine district of North Carolina, testing the economic feasibility of repurposing current mine waste tailings as a rare earth element resource. Spruce Pine is home to several active quartz and feldspar mining operations, with large waste tailing piles generated during the separation process for quartz and feldspar. The mineralogy, composition, and REE budget of the tailings was examined to assess the economic viability of rare earth element extraction. The local geology includes a series of muscovite class pegmatites of Devonian age (390 Ma), intruded into the primarily amphibolite-grade units of the Ashe and Alligator Back formations (Wood, 1996). The waste tailing piles of two on-going quartz mining operations were sampled to evaluate the potential economic feasibility of rare earth element extraction from key accessory phases, including apatite, remaining from the initial separation process. Sample characterization utilized laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), X-ray fluorescence (XRF), energy-dispersive X-ray spectrometry (EDS), and X-ray diffraction (XRD). The results of this investigation support the conclusion that, at the current recovery rate, price of rare earth elements, and cost of refinement, economic recovery of REE from the studied tailings is not viable. However, yttrium and dysprosium offer the highest potential for economic recovery. If some combination of improvements to the extraction process, reduction in refinement cost, or increases in price occur, yttrium and dysprosium are sufficiently abundant that extraction could become economically viable. / Master of Science / Rare Earth elements (REEs) are comprised of the Lanthanide series of elements as well as yttrium and scandium. REEs are economically important due to their critical applications within multiple industries. Current uses include electronics, magnets, lasers, electric motors, optical fibers, nuclear reactor control rods, visual displays, etc. Although the demand for REEs is high, the current sourcing of REEs is quite scarce. This study investigates the Spruce Pine district of North Carolina, testing the economic feasibility of repurposing current mine waste tailings as a rare earth element resource. Spruce Pine is home to several active quartz and feldspar mining operations, with large waste tailing piles generated during the separation process for quartz and feldspar. The mineralogy, composition and REE budget of the tailings was examined to assess the economic viability of rare earth element extraction. The waste tailing piles of two on-going quartz mining operations were sampled to evaluate the potential economic feasibility of rare earth element extraction from key accessory phases, including apatite, remaining from the initial separation process. The results of this investigation support the conclusion that, at the current recovery rate, price of rare earth elements, and cost of refinement, economic recovery of REE from the studied tailings is not viable. However, yttrium and dysprosium offer the highest potential for economic recovery. If some combination of improvements to the extraction process, reduction in cost of refinement, or increase in price were to occur, yttrium and dysprosium are sufficiently abundant that extraction could become economically viable.