Scum is an integral component of solids management in MWWTP and is composed of fats, oils, grease and other entrained floatable materials that are collected during primary clarification. Lab scale BMP tests showed the addition of 14.5 g VS/L of scum exhibited the greatest increase in biogas production of 1.6 times per g VS added compared to the control, while a higher additional scum loading of 33.7 g VS/L reduced the biogas yield to 32% of the control reactor. Lab scale semi-continuous digestion measured the effects of scum loading and temperature of pretreatment in the scum concentrator. At 15 d and 20 d HRTs the greatest observed improvement in biogas was achieved by adding 3% scum by volume and pretreating the scum at 70°C in a scum concentrator with respective improvements of 24% and 16%.

Slaughterhouse waste (SB) has high potential to be utilized in anaerobic digestion due to its high protein and lipid content. However, these are also the limiting factors of system stability. Thus, co-digestion of slaughterhouse waste with other agro-industrial residues (manure (M), various crops (VC) and municipal solid waste (MSW)) was introduced in this study to overcome this problem. The main objective of the work was to determine the operating parameters and the methane yield in semi-continuous co-digestion of slaughterhouse waste with other agro-industrial waste streams. Four continuously stirring tank reactors (CSTRs) with different substrates and mixtures (SB, SB:M, SB:VC and SB:VC:MSW) were started up operating with hydraulic retention time (HRT) of 25 days in thermophilic conditions. The highest organic loading rates which could be achieved were 0.9 g VS/L·d in digestion of SB and 1.5 g VS/L·d for the co-digestion mixtures. In these cases, average methane yields of 300, 510, 587 and 426 ml/g VS were obtained from the digestion of SB, and the co-digestion of SB:M, SB:VC and SB:VC: MSW, respectively, with methane contents in the biogas of 60-85%. The highest average methane yield of 587 ml/g VS was found in co-digestion of SB:VC, which was in accordance with the value of 592 ml/g VS detected during the batch digestion of the same mixture. Moreover, batch assays with different substrates as well as 11 different mixtures of those were also set up to investigate the methane potential and the effect of second feeding. The results showed that the co-digestion of SB:VC, SB:VC:MSW and SB:M could provide high methane potentials, where the highest methane yields of 592, 522 and 521 ml/g VS, respectively were obtained. Moreover, increasing, similar or decreasing methane yields were determined from the second feeding depending on the substrates and substrate mixtures used. / Program: MSc in Resource Recovery - Sustainable Engineering

As curvas limite de conformação (CLC) são utilizadas há mais de 50 anos. Propostas inicialmente para o desenvolvimento de produtos provenientes da indústria automobilista em função das necessidades apresentadas pela área, são atualmente aplicadas de maneira geral para a indústria da estampagem na produção de inúmeros tipos de peças, oferecendo previsões de possíveis falhas e/ou defeitos durante as etapas do processo de estampagem. As CLC´s permitem prever o afinamento excessivo, enrugamento, estiramento e é claro, a fratura da peça. As diferenças metalúrgicas existentes entre os dois processos iniciais - fundição contínua (F.C.) e fundição semicontínua (F.S.C.) - resultam em diferenças nas propriedades finais obtidas para uma mesma rota de laminação a frio e recozimentos intermediários do material especificado. Desta forma, torna-se indispensável um estudo sobre a influência dos processos de fabricação iniciais F.C. e F.S.C. com relação à estampabilidade da liga, sendo esta avaliação efetuada através das CLC´s obtidas por ensaios de tração uniaxiais, propostos pelo IRSID (\"Institut de Recherches de La Sidérurgie\"), (lado esquerdo da curva ?2 < 0) e ensaio Erichsen (lado direito da curva ?2 > 0) e do ensaio de Nakazima reduzido em 60%, ou seja, todo o ferramental e os corpos de prova utilizados nos ensaios foram reduzidos em 60% das dimensões mencionadas pela norma ISSO 12004-2. A diferença microestrutural apresentada entre as etapas de fabricação dos dois processos avaliada através de ensaios de determinação do tamanho de grão, limites de resistência à tração, escoamento (0,2%), alongamento (em 50,80 mm), coeficientes de encruamento n, resistência K, ensaios de \"orelha\", levantamento da CLC0, Erichsen e textura, auxiliaram nas conclusões finais do levantamento das CLC´s para os dois processos do material acabado e metodologias. O processo de fundição semicontínua nas condições processadas apresentou melhores combinações entre as propriedades, exceto na formação de \"orelha\" apresentada na etapa intermediaria de processamento do material. Principalmente o parâmetro CLC0 no plano da chapa, resultou em uma deformação ?1 19% (?2 = 0), superior à apresentada pelo processo F.C., deformação muito importante para a fabricação de peças estampadas. Evidenciou-se também uma diferença de aproximadamente 37% entre as metodologias IRSID x Nakazima reduzido na obtenção da deformação plana para o processo F.C. e 31% para o processo de F.S.C.. Nas condições de deformação; estiramento biaxial, tração uniaxial e embutimento profundo, a chapa produzida pelo processo de fundição contínua apresenta melhor desempenho. / Forming limits curves (FLC) are used for more than 50 years. Initially proposed for the development of products from the automobile industry in terms of the needs of the area. It is currently being applied in general to the metal forming industry in the production of numerous types of parts, providing predictions of possible faults and / or defects during the stages of the stamping process. The FLC\'s can predict excessive thinning, wrinkling, stretching and of course, the fracture of the part. The existing metallurgical differences between the two initial processes - continuous casting (C.C.) and semi-continuous casting (S.C.C.) - result in differences in the final properties obtained for the same route of cold rolling and intermediate annealing of the specified material. Thus, it is essential to study the influence of the initial manufacturing processes CC and SCC with respect to the formability of the sheets. This investigation is based on the, assessment of the FLC\'s obtained by uniaxial tensile tests proposed by IRSID (\"Institut de Recherches de Sidérurgie\"), (?2 < 0, left side of the curve) and Erichsen test (right side of curve. ?2> 0) and the Nakazima test reduced by 60%. The difference between the sheets obtained in both processing routes was evaluated by the following parameters: grain size, tensile strength limits, yield strength (0.2%), elongation (at 50.80 mm), strain hardening coefficient n, resistance K, \"earing\" test, lifting of the CLC0, Erichsen test and texture where discussed in view of the obtained FLC\'s for both the two processes of the finished material. The semi-continuous casting process in processed conditions showed better combinations of properties except the formation of \"earing\" presented at the intermediate stage of processing of the material. Particularly the evaluation of the FLC0 parameter resulted in a strain in the plate plane ?1 19% (?2 = 0) superior to the sheet obtained by the continuous casting process. A difference of approximately 37% between the IRSID x Nakazima methodologies was also reduced in obtaining the flat deformation for the F.C. process and 31% for the F.S.C. process. However, for other deformation paths; biaxial stretching, uniaxial traction and deep drawing of the results for the continuous casting sheet were superior.

Scum is an integral component of solids management in MWWTP and is composed of fats, oils, grease and other entrained floatable materials that are collected during primary clarification. Lab scale BMP tests showed the addition of 14.5 g VS/L of scum exhibited the greatest increase in biogas production of 1.6 times per g VS added compared to the control, while a higher additional scum loading of 33.7 g VS/L reduced the biogas yield to 32% of the control reactor. Lab scale semi-continuous digestion measured the effects of scum loading and temperature of pretreatment in the scum concentrator. At 15 d and 20 d HRTs the greatest observed improvement in biogas was achieved by adding 3% scum by volume and pretreating the scum at 70°C in a scum concentrator with respective improvements of 24% and 16%.

This study aimed at seeking for the solution to recover the energy from agriculture waste in the Mekong Delta, Vietnam. The spent mushroom compost - a residue from the mushroom growing - was chosen for co-digestion with pig manure in anaerobic batch and semi-continuous experiments. The results showed that in case of spent mushroom compost made up 75% of the mixed substrate, the gained biogas volume was not significantly different compared to the treatment fed solely with 100% pig manure. The average produced biogas was 4.1 L×day-1 in the experimental conditions. The semi-continuous experiments remained in good operation up to the 90th day of the fermentation without any special agitating method application. The methane contents in both experiments were around 60%, which was significantly suitable for energy purposes. These results confirm that spent mushroom compost is possibly an acceptable material for energy recovery in the anaerobic fermentation process. / Nghiên cứu này nhằm tìm kiếm giải pháp thu hồi năng lượng từ chất thải nông nghiệp tại ĐBSCL, Việt Nam. Rơm sau ủ nấm - phế phẩm sau khi trồng nấm rơm - được chọn để ủ kết hợp với phân heo trong các bộ ủ yếm khí theo mẻ và bán liên tục. Kết quả cho thấy nếu phối trộn đến 75% rơm sau ủ nấm trong nguyên liệu ủ, tổng lượng khí thu được không khác biệt đáng kể so với thí nghiệm ủ 100% phân heo. Trong điều kiện thí nghiệm, lượng khí thu được trung bình là 4.1 L.ngày-1. Thí nghiệm ủ bán liên tục vẫn vận hành tốt ở ngày thứ 90 mặc dù mẻ ủ không được khuấy đảo. Hàm lượng khí mê-tan đo được chiếm khoảng 60% hoàn toàn có thể sử dụng cho các nhu cầu về năng lượng. Những kết quả thí nghiệm khẳng định có thể sử dụng rơm sau ủ nấm để thu hồi năng lượng thông qua quá trình ủ yếm khí kết hợp.

As curvas limite de conformação (CLC) são utilizadas há mais de 50 anos. Propostas inicialmente para o desenvolvimento de produtos provenientes da indústria automobilista em função das necessidades apresentadas pela área, são atualmente aplicadas de maneira geral para a indústria da estampagem na produção de inúmeros tipos de peças, oferecendo previsões de possíveis falhas e/ou defeitos durante as etapas do processo de estampagem. As CLC´s permitem prever o afinamento excessivo, enrugamento, estiramento e é claro, a fratura da peça. As diferenças metalúrgicas existentes entre os dois processos iniciais - fundição contínua (F.C.) e fundição semicontínua (F.S.C.) - resultam em diferenças nas propriedades finais obtidas para uma mesma rota de laminação a frio e recozimentos intermediários do material especificado. Desta forma, torna-se indispensável um estudo sobre a influência dos processos de fabricação iniciais F.C. e F.S.C. com relação à estampabilidade da liga, sendo esta avaliação efetuada através das CLC´s obtidas por ensaios de tração uniaxiais, propostos pelo IRSID (\"Institut de Recherches de La Sidérurgie\"), (lado esquerdo da curva ?2 < 0) e ensaio Erichsen (lado direito da curva ?2 > 0) e do ensaio de Nakazima reduzido em 60%, ou seja, todo o ferramental e os corpos de prova utilizados nos ensaios foram reduzidos em 60% das dimensões mencionadas pela norma ISSO 12004-2. A diferença microestrutural apresentada entre as etapas de fabricação dos dois processos avaliada através de ensaios de determinação do tamanho de grão, limites de resistência à tração, escoamento (0,2%), alongamento (em 50,80 mm), coeficientes de encruamento n, resistência K, ensaios de \"orelha\", levantamento da CLC0, Erichsen e textura, auxiliaram nas conclusões finais do levantamento das CLC´s para os dois processos do material acabado e metodologias. O processo de fundição semicontínua nas condições processadas apresentou melhores combinações entre as propriedades, exceto na formação de \"orelha\" apresentada na etapa intermediaria de processamento do material. Principalmente o parâmetro CLC0 no plano da chapa, resultou em uma deformação ?1 19% (?2 = 0), superior à apresentada pelo processo F.C., deformação muito importante para a fabricação de peças estampadas. Evidenciou-se também uma diferença de aproximadamente 37% entre as metodologias IRSID x Nakazima reduzido na obtenção da deformação plana para o processo F.C. e 31% para o processo de F.S.C.. Nas condições de deformação; estiramento biaxial, tração uniaxial e embutimento profundo, a chapa produzida pelo processo de fundição contínua apresenta melhor desempenho. / Forming limits curves (FLC) are used for more than 50 years. Initially proposed for the development of products from the automobile industry in terms of the needs of the area. It is currently being applied in general to the metal forming industry in the production of numerous types of parts, providing predictions of possible faults and / or defects during the stages of the stamping process. The FLC\'s can predict excessive thinning, wrinkling, stretching and of course, the fracture of the part. The existing metallurgical differences between the two initial processes - continuous casting (C.C.) and semi-continuous casting (S.C.C.) - result in differences in the final properties obtained for the same route of cold rolling and intermediate annealing of the specified material. Thus, it is essential to study the influence of the initial manufacturing processes CC and SCC with respect to the formability of the sheets. This investigation is based on the, assessment of the FLC\'s obtained by uniaxial tensile tests proposed by IRSID (\"Institut de Recherches de Sidérurgie\"), (?2 < 0, left side of the curve) and Erichsen test (right side of curve. ?2> 0) and the Nakazima test reduced by 60%. The difference between the sheets obtained in both processing routes was evaluated by the following parameters: grain size, tensile strength limits, yield strength (0.2%), elongation (at 50.80 mm), strain hardening coefficient n, resistance K, \"earing\" test, lifting of the CLC0, Erichsen test and texture where discussed in view of the obtained FLC\'s for both the two processes of the finished material. The semi-continuous casting process in processed conditions showed better combinations of properties except the formation of \"earing\" presented at the intermediate stage of processing of the material. Particularly the evaluation of the FLC0 parameter resulted in a strain in the plate plane ?1 19% (?2 = 0) superior to the sheet obtained by the continuous casting process. A difference of approximately 37% between the IRSID x Nakazima methodologies was also reduced in obtaining the flat deformation for the F.C. process and 31% for the F.S.C. process. However, for other deformation paths; biaxial stretching, uniaxial traction and deep drawing of the results for the continuous casting sheet were superior.

Scum is an integral component of solids management in MWWTP and is composed of fats, oils, grease and other entrained floatable materials that are collected during primary clarification. Lab scale BMP tests showed the addition of 14.5 g VS/L of scum exhibited the greatest increase in biogas production of 1.6 times per g VS added compared to the control, while a higher additional scum loading of 33.7 g VS/L reduced the biogas yield to 32% of the control reactor. Lab scale semi-continuous digestion measured the effects of scum loading and temperature of pretreatment in the scum concentrator. At 15 d and 20 d HRTs the greatest observed improvement in biogas was achieved by adding 3% scum by volume and pretreating the scum at 70°C in a scum concentrator with respective improvements of 24% and 16%.

Semicontinuous data consist of a combination of a point-mass at zero and a positive skewed distribution. This type of non-negative data distribution is found in data from many fields, but presents unique challenges for analysis. Specifically, these data cannot be analyzed using positive distributions, but distributions that are unbounded are also likely a poor fit. Two-part models incorporate both the zero values from semicontinuous data and the positive continuous values. In this dissertation, we compare zero-inflated gamma (ZIG) and zero-inflated log-normal (ZILN) two-part models. For both of these models, the probability that an outcome is non-zero is modeled via logistic regression. Then the distribution of the non-zero outcomes is modeled via gamma regression with a log-link for ZIG regression and via log-normal regression for ZILN. In this dissertation we propose tests which combine the two parts of the ZIG and ZILN models in meaningful ways for performing a two group comparison. Then we compare these tests in terms of observed Type 1 error rates and power levels under both correctly specified and misspecified ZIG and ZILN models. Tests falling under two main hypotheses are examined. First, we look at two-part tests which come from a two-part hypothesis of no difference between the two groups in terms of the probability of non-zero values and in terms of the the mean of the non-zero values. The second type of tests are mean-based tests. These combine the two parts of the model in ways related to the overall group means of the semicontinuous variable. When not adjusting for covariates, two tests are developed based on a difference of means (DM) and a ratio of means (RM). When adjusting for covariates, tests using mean-based hypotheses are developed which marginalize over the values of the adjusting covariates. Under the adjusting framework, two ratio of means statistics are proposed and examined, an average of the subject specific ratio of means (RMSS) and a ratio of the marginal group means (RMMAR). Simulations are used to compare Type 1 error and power for these tests and standard two group comparison tests. Simulation results show that when ZIG and ZILN models are misspecified and the coefficient of variation (CoV) and/or sample size is large, there are differences in Type 1 error and power results between the misspecified and correctly specified models. Specifically, when ZILN data with high CoV or sample size are analyzed as ZIG, Type 1 error rates are prohibitively high. On the other hand, when ZIG data are analyzed as ZILN under these scenarios, power levels are much lower for ZILN analyses than for ZIG analyses. Examination of Q-Q plots show, however, that in these settings, distinguishing between ZIG and ZILN data can be relatively straightforward. When the coefficient of variation is small it is harder to distinguish between ZIG and ZILN models, but the differences between Type 1 error rates and power levels for misspecified or correctly specified models is also slight. Finally, we use the proposed methods to analyze a data set involving Parkinson's disease (PD) and driving. A number of these methods show that PD subjects exhibit poorer lane keeping ability than control subjects.

abstract: Over the past decade, there has been a revival in applied algal research and attempts at commercialization. However, the main limitation in algal commercialization is the process of cultivation, which is one of the main cost and energy burdens in producing biomass that is economically feasible for different products. There are several parameters that must be considered when growing algae, including the type of growth system and operating mode, preferred organism(s), and many other criteria that affect the process of algal cultivation. The purpose of this dissertation was to assess key variables that affect algal productivity and to improve outdoor algal cultivation procedures. The effect of reducing or eliminating aeration of algal cultures at night, in flat panel photobioreactors (panels), was investigated to assess the reduction of energy consumption at night. The lack of aeration at night resulted in anoxic conditions, which significantly reduced lipid accumulation and productivity, but did not affect log phase biomass productivity. In addition, the reduction in aeration resulted in lower pH values, which prevented ammonia volatility and toxicity. Raceways are operated at deeper cultivation depths, which limit culture density and light exposure. Experimentation was accomplished to determine the effects of decreasing cultivation depth, which resulted in increased lipid accumulation and lipid productivity, but did not significantly affect biomass productivity. A comparison of semi-continuous cultivation of algae in raceways and panels in side-by-side experiments showed that panels provided better temperature control and higher levels of mixing, which resulted in higher biomass productivity. In addition, sub-optimal morning temperatures in raceways compared to panels were a significant factor in reducing algae biomass productivity. The results from this research indicate that increasing lipid productivity and biomass productivity cannot be completed simultaneously. Therefore, the desired product will determine if lipid or biomass productivity is more crucial, which also dictates whether the system should be operated in batch mode to either allow lipid accumulation or in semi-continuous mode to allow high biomass productivity. This work is a critical step in improving algal cultivation by understanding key variables that limit biomass and lipid productivity. / Dissertation/Thesis / Doctoral Dissertation Civil and Environmental Engineering 2015

A number of articles only present hurdle models for count data. we are motivated to present hurdle models for semi-continuous data. Because semi- continuous data is also commonly seen in non-life insurance. The thesis deals with the parameterization of various hurdle models for semi-continuous data besides for count data in non-life insurance. Two components of a hurdle model are modeled separately. A hurdle component is modeled by a logistic regression. For a semi-continuous data, a continuous component is modeled by several various regressions. Parameters of each component are estimated through maximum likelihood estimation. Model selection is mentioned before theoretical approaches are applied on the vehicle insurance data. Finally, we get some predicted values based on the fitted models. The prediction gives insurance companies a general idea on setting premium but not accurate. 1