Dramatically higher fuel prices and massive petroleum imports from politically unstable countries have contributed to a major national initiative to generate renewable fuels in the United States. Often, such policies are enacted and implemented with huge taxpayer expenditures without due diligence to the consequences. The evaluation of the water quality impacts of converting pastureland to intensive biomass production for fuel in a southern Texas watershed suggest significant increases erosion and nutrient loadings to water bodies. The Best Management Practices (BMPs), cover crop and filter strips when implemented individually failed to produce status-quo reduction levels. Combined BMPs implementation produced improved mitigation, at substantially higher costs, highlighting the issue of sustainability related to the economics of renewable fuels. The estimation of the net energy of biomass ethanol accounting for the production input data indicate a greater than one energy return for biomass crops. However, the policy results indicate that only 70 percent in net contribution to the energy supply is achieved due to relatively lower energy returns compared to conventional fossil fuels. In addition, because the ethanol produced has to have the energy used deleted from the total, the cost of producing a gallon of biomass ethanol is substantially higher than that of gasoline. The impacts of an exogenously-specified biofuel mandate fulfilled by the production of a dedicated biomass crop and its consequent effects on commodity prices and overall welfare are estimated. Net farm income increased due to an increase in crop prices; however, both consumer surplus and total surplus decreased. The analysis is extended to estimate the sensitivity of Conservation Reserve Program (CRP) acres returning to crop production and the potential of higher biomass yields. The results indicate that net farm income decreased and consumer surplus increased due to a decrease in crop prices, resulting in an increase in overall welfare. This current research evaluates the unintended consequences of the U.S. energy policy and provides interesting insights of the potential economic and environmental impacts. These results suggest policy makers should be cautious before enacting energy policy and consider multiple alternative energy sources in an economic and financial context to achieve a sustainable energy goal.

Net energy exporting countries (NEECs) and net energy importing countries (NEICs) depend on each other for mutual gains. However, NEICs pursue strategic policies to reduce consumption of energy from conventional sources and increase that of renewable energy in order to attain energy security and macro environmental and carbon accountability. On the other hand, NEECs such as Nigeria depend heavily on oil and gas exports to NEICs to generate revenue. As a result of this inter-dependent relationship, this PhD project adopts a dependency theory and strategic issue analysis framework to underpin the study. Accordingly, the study approach is founded on the ideas of pluralism as a social reality and adopted pragmatism as the research approach. Consistent with these approaches, the study was undertaken by analysing both secondary and primary data, including macro-economic statistics of annual time-series dataset (1980-2014) and semi-structured interviews respectively. The quantitative part of the project used Auto Regressive Distributed Lag (ARDL) Bounds testing approach. This method was used to investigate and analyse the effect of renewable energy consumption and carbon emissions reduction on Nigeria’s oil and gas exports. The qualitative part involved interviews with twenty senior government officials in Nigeria from six selected Federal Ministries, Departments and Agencies (MDAs), representatives of civil society groups and academicians, to support the quantitative results and answer certain research questions. The short-run quantitative results and qualitative findings show that renewable energy consumption in developed NEICs affects Nigeria’s oil and gas exports. However, the reverse holds true for emerging NEICs. Both the quantitative results and the qualitative findings show that carbon emissions reduction in developed NEICs affects Nigerian oil and gas exports in the long run. Also, the quantitative results show that renewable energy consumption in developed and emerging NEICs does not affect Nigerian oil and gas exports in the long run. However, the qualitative findings only support the quantitative results for emerging NEICs but do not support those of developed NEICs. Similarly, the qualitative findings indicate that other external and internal factors such as discovery of shale oil and gas; improvement in energy efficient technologies; the use of long-term contract in other NEECs; stringent nature of the Nigerian Content Law and lack of passage of the Petroleum Industry Bill amongst others currently contribute in affecting Nigeria’s oil and gas exports. Moreover, the qualitative findings show that global energy transition has an impact on the Nigeria’s oil and gas revenue, savings made to the Nigerian Sovereign Wealth Fund, budget financing and will continue to affect Nigerian revenue and budget if the economy remains undiversified. Finally, the qualitative findings indicate that global energy transition has negatively affected Foreign Direct Investment flow into Nigerian petroleum industry and discoveries of new oil and gas reserves. These findings have several implications. Firstly, Nigerian oil and gas exports are affected by the carbon emissions control regime, which makes future oil and gas revenues uncertain; thereby putting pressure on budget financing and socio-economic growth and development. On this note, there is the need for Nigeria to take cautionary position in the global climate change debate in order not to adversely affect the country’s economic interest. Secondly, the consumption of energy from renewable sources in both developed and emerging NEICs is an opportunity for Nigeria to export not only its conventional energy but also renewable energy if commercially harnessed. This suggests that Nigerian should also invest heavily in renewable energy production. Thirdly, the major findings of this study provide evidence in support of the relevance of dependency theory and strategic issue analysis framework within the context of energy transition in NEICs on one hand, and Nigerian oil and gas exports to these countries on the other. This implies the need for Nigeria to focus on developing internal market trajectories to increase domestic utilisation of its conventional energy rather than being dependent on external markets for the sale of the nation’s energy resources.

O objetivo deste trabalho foi avaliar a substituição parcial (30%) da polpa cítrica peletizada (PCP) por polpa de citros úmida despectinada (PCUD) na ração de bovinos em terminação. No 1o experimento, utilizou-se a PCUD em sua forma in natura. Para este ensaio foram utilizados 48 machos não castrados (24 Nelore e 24 Canchim) com idade aproximada de 18 meses e peso vivo inicial de 404 e 439 kg para Nelore e Canchim, respectivamente. O delineamento utilizado foi o de blocos ao acaso com arranjo fatorial 2x2 (duas raças e dois tratamentos) com os animais agrupados por raça e peso vivo inicial. O período experimental foi de 92 dias divididos em três períodos. As rações foram compostas de bagaço de cana-de-açúcar in natura, PCP, farelo de soja, uréia, núcleo mineral e vitamínico, bicarbonato de sódio e monensina sódica, além da polpa de citros úmida despectinada in natura. No 2o experimento, utilizou-se a PCUD em sua forma ensilada, aditivada na ensilagem ou não com benzoato de sódio (0,18% da MV). Para este ensaio foram utilizados 54 machos não castrados tricross (Nelore/Angus ou Nelore/Santa Gertrudis x Pardo Suíço de corte) com idade aproximada de 16,5 meses e peso vivo inicial de 303 kg. O delineamento utilizado foi o de blocos ao acaso com os animais agrupados por peso vivo inicial. O período experimental foi de 91 dias divididos em três períodos. As rações foram compostas de bagaço de cana-de-açúcar in natura, PCP, farelo de algodão, uréia, núcleo mineral e vitamínico, bicarbonato de sódio e monensina sódica, além da PCUD ensilada com e sem benzoato de sódio. Para os dois ensaios as rações continham 85% de ingredientes concentrados e 15% de bagaço cana-de-açúcar in natura, formuladas de acordo com o NRC (Gado de corte) nível 1 para serem isoprotéicas e com balanço positivo de proteína degradável no rúmen e proteína metabolizável. Foram avaliados o ganho de peso diário (kg/dia de PV), o consumo de matéria seca (kg/dia de MS), a conversão alimentar (consumo de matéria seca/ganho de peso diário), a energia líquida para manutenção, ganho e energia metabolizável das rações (Mcal/kg de MS) e a relação entre a energia calculada com os dados do experimento e a predita pelo NRC (1996) nível 1 (observado/predito). Em ambos os experimentos, a substituição da PCP por PCUD aumentou a ingestão de fibra em detergente neutro e fibra em detergente ácido (P<0,01) e não afetou o consumo de matéria seca (8,05 vs. 8,13 e 7,76 vs. 7,78 kg/dia para o 1o e 2o ensaio, respectivamente), o ganho de peso diário (1,11 vs.1,16 e 1,27 vs. 1,36 kg/dia para o 1o e 2o ensaio, respectivamente) e a conversão alimentar (7,82 vs. 7,29 e 6,62 vs. 5,96 kg de MS/kg de GPD para o 1o e 2o ensaio, respectivamente). Os valores observados de energia líquida de manutenção, ganho e energia metabolizável das rações não diferiram (P>0,05) entre os tratamentos. Já a relação de energia (observada/predita) do tratamento com PCP foi inferior (P<0,05) à da ração contendo PCUD (1,15; 1,39; 1,22 vs. 1,23; 1,51; 1,28 e 1,10; 1,31; 1,18 vs. 1,18; 1,45; 1,24 Mcal/kg MS de ELm, ELg e EM para o 1o e 2o ensaio, respectivamente). A substituição parcial de PCP por PCUD in natura ou ensilada não alterou o desempenho dos animais. / The objective of this study was evaluate despectinated citrus pulp (Braspolpa®) replacing 30% of pelleted citrus pulp in feedlot beef cattle finishing diets. In the first trial, was used despectinated citrus pulp in natura. Forty eight yearling bulls (24 Nelore and 24 Canchim), 18 months old and averaging 404 and 439 kg initial live weight for Nelore and Canchim, respectively. The animals were assigned in a randomized block design with a 2x2 factorial scheme (two breeds and two treatments) and grouped by breed and initial live weight. Experimental period lasted 92 days, with three periods. Diets contained sugar cane bagasse in natura, dried citrus pulp, soybean meal, urea, mineralvitamin mix, sodium bicarbonate, sodium monensin, and the energy sources tested (despectinated citrus pulp). In the second trial, the despectinated citrus pulp was ensiled with or without sodium benzoate (0.18% of GM). Fifty four yearling bulls (Nelore/Angus or Nelore Santa Gertrudis x Braunvieh), 16.5 months old and averaging 303 kg initial live weight. The animals were assigned in a complete randomized block design, and grouped by initial live weight. Experimental period lasted 91 days, with three periods. Diets contained sugar cane bagasse in natura, dried citrus pulp, cotton meal, urea, mineral-vitamin mix, sodium bicarbonate, sodium monensin, and the energy sources tested (despectinated citrus pulp with and without sodium benzoate). For these two trials, the rations were composed of 85% of the concentrate and 15% of the sugar cane bagasse in natura, and were balanced according to NRC (1996) level 1, to reach isonitrogeneous with positive rumen degradable protein and metabolizable protein balances. Variables evaluated were daily weight gain (DWG, kg/day), dry matter intake (DMI, kg DM/day), feed conversion (FC, kg DMI/kg DWG), net energy for maintenance and gain values, and the ratio between calculated net energy (based on experimental data) and net energy predicted by NRC (1996), level 1 (observed/predicted). In both trials, the substitution of dried citrus pulp for despectinated citrus pulp increased the NDF and ADF intakes (P<0.01) and did not affect (P>0.05) DMI (8.05 vs. 8.13 and 7.76 vs. 7.78 kg/day for the first and second trials, respectively), DWG (1.11 vs. 1.16 e 1.27 vs. 1.36 kg/day for the first and second trials, respectively), neither FC (7.82 vs. 7.29 e 6.62 vs. 5.96 kg of DM/kg for the first and second trials, respectively). Observed values for net energies of maintenance and gain did not differ among treatments (P>0.05). According to the experimental data, the net energy relation (observed/predicted) for the PCP treatment was lower (P<0.05) than PCUD treatment (1.15; 1.39; 1.22 vs. 1.23; 1.51; 1.28 and 1.10; 1.31; 1.18 vs. 1.18; 1.45; 1.24 Mcal/kg DM of NEm, NEg and ME for the first and second trials, respectively). The partial replacing of PCP for PCUD in natura or ensiling did not change the animal performance.

Micro- generation is the small-scale and localised provision of heat or electricity. Micro-generators have the potential to reduce greenhouse-gas emissions and enhance energy security by providing heat or electricity from either renewable sources, or via the more efficient use of fossil fuels. But this potential is often unquantified or unclear, and hence quantitative information is required concerning both the energetic performance of micro-generators and their ability to provide net reductions in carbon emissions. <br /> In the context of household energy provision in the UK, thermodynamic and related carbon analyses of three micro-generation technologies have been carried out. These studies contribute to the research of the SUPERGEN ‘Highly Distributed Power Systems’ Consortium, which has been addressing a broad range of issues regarding micro-generation. The technologies analysed here are a grid-tied micro-wind turbine (rotor diameter 1.7m, rated power 600 W at 12 m/s), a grid-tied solar photovoltaic array (15 m2, 2.1 kWp mono-crystalline silicon), and a solar hot-water system (2.8 m2 flat-plate collector, direct-feed system). Annual energy outputs were estimated and contextualised against the demands of representative UK households. The overall energy-resource and carbon savings provided by the micro-generators were assessed on the basis that they (partially) displace the established supply systems. Savings were then compared with the energy-resource and carbon ‘debts’ of the micro-generators to determine their net performance. <br /> The displaced energy or carbon payback periods of the micro-generators were estimated to be well within their estimated lifetimes: a maximum 2.5 years for the SHW system, 3.1 years for the micro-wind turbine installed in an ‘open’ environment, and 7.4 years for the solar PV system. After payback, net energy-resource and carbon savings accrue. This thesis thus demonstrates that, given appropriate UK installations, all three micro-generators can reduce carbon emissions and enhance energy security by reducing use of, and dependence upon, fossil fuels.

Installed photovoltaic nameplate power have been growing rapidly around the worldin the last few years. But how much energy is returned to society (i.e. net energy) by this technology, and which factors contribute the most to the amount of energy returned? The objective of this thesis was to examine the importance of certain inputs and outputs along the solar panel production chain and their effect on the energy return on (energy) investment (EROI) for crystalline wafer-based photovoltaics. A process-chain model was built using publicly available life-cycle inventory (LCI) datasets. This model has been kept simple in order to ensure transparency. Univariate sensitivity analysis for processes and multivariate case studies was then applied to the model. The results show that photovoltaic EROI values are very sensitive to assumptions regarding location and efficiency. The ability of solar panels to deliver net energy in northern regions of the earth is questionable. Solar cell wafer thickness have a large impact on EROI, with thinner wafers requiring less silicon material. Finding an alternative route for production of solar-grade silicon is also found to be of great importance, as is introduction of kerf loss recycling. Equal system sizes have been found to yield an primary EROI between approximately 5.5-19 depending on location and assumptions. This indicates that a generalized absolute EROI for photovoltaics may be of little use for decision-makers. Using the net energy cliff concept in relation to primary EROI found in this thesis shows that primary EROI rarely decreases to less than the threshold of 8:1 in univariate cases. Crystalline photovoltaics under similar system boundaries as those in the thesis model does not necessarily constrain economic growth on an energetic basis.

No description available.

The effect of exercise (EXR) on food intake (FI), subjective appetite and net energy balance was investigated in normal weight (NW), overweight (OW) and obese (OB) boys. Each boy received in random order either a non-caloric sweetened control (CON) or glucose (GLU) drink after either EXR or sedentary activity. Normal weight and OW/OB boys exercised at their ventilation threshold (VeT) in experiment 1 and NW boys exercised at 25% above their VeT in experiment 2. Overweight/OB boys ate significantly more total food than NW boys but not when adjusted for body weight. Food intake was lower after the GLU drink. Although EXR increased average appetite it did not affect FI. However, net energy balance was reduced by EXR in OW/OB boys, but not in NW boys. Thus, while EXR increases subjective appetite, apparent intake compensation occurred only in NW, but not in OW/OB boys, resulting in reduced net energy balance in OW/OB boys.

The effect of exercise (EXR) on food intake (FI), subjective appetite and net energy balance was investigated in normal weight (NW), overweight (OW) and obese (OB) boys. Each boy received in random order either a non-caloric sweetened control (CON) or glucose (GLU) drink after either EXR or sedentary activity. Normal weight and OW/OB boys exercised at their ventilation threshold (VeT) in experiment 1 and NW boys exercised at 25% above their VeT in experiment 2. Overweight/OB boys ate significantly more total food than NW boys but not when adjusted for body weight. Food intake was lower after the GLU drink. Although EXR increased average appetite it did not affect FI. However, net energy balance was reduced by EXR in OW/OB boys, but not in NW boys. Thus, while EXR increases subjective appetite, apparent intake compensation occurred only in NW, but not in OW/OB boys, resulting in reduced net energy balance in OW/OB boys.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / In swine production the post weaning period is considered one of the most critical periods of the production. The state of Rio Grande do Sul presents great availability of by-products from rice processing that may be an alternative on the feeding of swine. The net energy is the one that represents better the energy value used by the animal however its determination by the conventional methods results in costs and manpower, being suggested the use of prediction equations for calculating. Two digestibility trials were performed with 12 and 18 male castrated swine with initial weight of 8 kg and 16 kg, respectively. In both studies, the animals were placed in metabolic cages during a period of twelve days, being seven days of adaptation and five days of collection. The experimental procedure was the total fecal collection using the ferric oxide as fecal marker. Data of digestibility and energy values of the co products were submitted to variance analysis using the completely randomly design and the Tukey test, used for comparing the averages between the feed. The digestibility coefficients of the organic matter, crude protein and gross energy were higher (P<0.000) for the broken rice (BR) compared to the stabilized rice bran (SRB) and parboiled rice bran (PRB). On the other hand, the BR presented lower (P<0.000) digestibility coefficient of the mineral matter than the rice bran's evaluated. The PRB presented a digestible energy 2% lower than the BR and 5% higher than the SRB. The observed metabolized energy on BR was the highest, followed by the PRB and SRB that presented the lowest value. The average value of net energy was 3094, 2646 and 2818 kcal/kg for the BR, SRB and PRB, respectively. The net energy value varies according to the equation used to estimate it. Based on data of chemical composition, digestible using and energy values it may be affirmed that the broken rice stabilized rice bran and parboiled rice bran may be used on the feeding of piglets. / Na criação de suínos o período pós desmame é considerado um dos mais críticos da etapa de produção. O Rio Grande do Sul apresenta grande disponibilidade de subprodutos oriundos do beneficiamento do arroz que podem ser alternativa na alimentação de suínos. A energia líquida é a que melhor representa o valor de energia utilizada pelo animal, porém sua determinação pelos métodos convencionais onera em custos e mão de obra, sendo sugerido o uso de equações de predição para o cálculo. Foram realizados dois ensaios de digestibilidade com 12 e 18 suínos machos castrados com peso inicial de 8 kg e 16 kg, respectivamente. Em ambos os estudos, os animais foram alojados em gaiolas metabólicas por um período de doze dias, sendo sete dias de adaptação e cinco dias de coleta. O procedimento experimental foi o de coleta total de fezes usando o óxido férrico como marcador fecal. Os dados de digestibilidade e valores energéticos dos coprodutos foram submetidos à análise de variância utilizando o delineamento inteiramente casualizado e o teste de Tukey usado para comparar as médias entre os alimentos. Os coeficientes de digestibilidade da matéria orgânica, proteína bruta e energia bruta foram maiores (P<0,000) para a quirera de arroz (QA) em comparação ao farelo de arroz estabilizado (FAE) e farelo de arroz parboilizado (FAP). Por outro lado, a QA teve menor (P<0,000) coeficiente de digestibilidade da matéria mineral que os farelos de arroz avaliados. O FAP apresentou energia digestível 2% inferior a QA e 5% superior ao FAE. Foi observada maior energia metabolizável na QA, seguido pelo FAP e FAE que apresentou o menor valor. O valor médio de energia líquida foi de 3094, 2646 e 2818 kcal/kg para a QA, FAE e FAP, respectivamente. O valor de energia líquida varia de acordo com a equação utilizada para estimá-la. Baseado nos dados de composição química, utilização digestiva e valores de energia, pode-se afirmar que a quirera de arroz, farelo de arroz estabilizado e farelo de arroz parboilizado podem ser usados na alimentação de leitões.

abstract: The consumption of feedstocks from agriculture and forestry by current biofuel production has raised concerns about food security and land availability. In the meantime, intensive human activities have created a large amount of marginal lands that require management. This study investigated the viability of aligning land management with biofuel production on marginal lands. Biofuel crop production on two types of marginal lands, namely urban vacant lots and abandoned mine lands (AMLs), were assessed. The investigation of biofuel production on urban marginal land was carried out in Pittsburgh between 2008 and 2011, using the sunflower gardens developed by a Pittsburgh non-profit as an example. Results showed that the crops from urban marginal lands were safe for biofuel. The crop yield was 20% of that on agricultural land while the low input agriculture was used in crop cultivation. The energy balance analysis demonstrated that the sunflower gardens could produce a net energy return even at the current low yield. Biofuel production on AML was assessed from experiments conducted in a greenhouse for sunflower, soybean, corn, canola and camelina. The research successfully created an industrial symbiosis by using bauxite as soil amendment to enable plant growth on very acidic mine refuse. Phytoremediation and soil amendments were found to be able to effectively reduce contamination in the AML and its runoff. Results from this research supported that biofuel production on marginal lands could be a unique and feasible option for cultivating biofuel feedstocks. / Dissertation/Thesis / M.S. Sustainability 2013