This work is motivated by the pressing need for operational control in the fabrication of Microelectromechanical systems or MEMS. MEMS are miniature three-dimensional integrated electromechanical systems with the ability to absorb information from the environment, process this information and suitably react to it. These devices offer tremendous advantages owing to their small size, low power consumption, low mass and high functionality, which makes them very attractive in applications with stringent demands on weight, functionality and cost. While the system''s "brain" (device electronics) is fabricated using traditional IC technology, the micromechanical components necessitate very intricate and sophisticated processing of silicon or other suitable substrates. A dearth of fabrication facilities with micromachining capabilities and a lengthy gestation period from design to mass fabrication and commercial acceptance of the product in the market are factors most often implicated in hampering the growth of MEMS. These devices are highly application specific with low production volumes and the few fabs that do possess micromachining capabilities are unable to offer a complete array of fabrication processes in order to be able to cater to the needs of the MEMS R&D community. A distributed fabrication network has, therefore, emerged to serve the evolving needs of this high investment, low volume MEMS industry. Under this environment, a central facility coordinates between a network of fabrication centers (Network of MEMS job shops -- NMJS) containing micromachining capabilities. These fabrication centers include commercial, academic and government fabs, which make their services available to the ordinary customer. Wafers are shipped from one facility to another until all processing requirements are met. The lengthy and intricate process sequences that need to be performed over a network of capital intensive facilities are complicated by dynamic job arrivals, stochastic processing times, sequence-dependent set ups and travel between fabs. Unless the production of these novel devices is carefully optimized, the benefits of distributed fabrication could be completely overshadowed by lengthy lead times, chaotic routings and costly processing. Our goal, therefore, is to develop and validate an approach for optimal routing (assignment) and sequencing of MEMS devices in a network of stochastic job shops with the objective of minimizing the sum of completion times and the cost incurred, given a set of fabs, machines and an expected product mix. In view of our goal, we begin by modeling the stochastic NMJS problem as a two-stage stochastic program with recourse where the first-stage variables are binary and the second-stage variables are continuous. The key decision variables are binary and pertain to the assignment of jobs to machines and their sequencing for processing on the machines. The assignment variables essentially fix the route of a job as it travels through the network because these variables specify the machine on which each job-operation must be performed out of several candidate machines. Once the assignment is decided upon, sequencing of job-operations on each machine follows. The assignment and sequencing must be such that they offer the best solution (in terms of the objective) possible in light of all the processing time scenarios that can be realized. We present two approaches for solving the stochastic NMJS problem. The first approach is based on the L-shaped method (credited to van Slyke and Wets, 1969). Since the NMJS problem lacks relatively complete recourse, the first-stage solution can be infeasible to the second-stage problem in that the first stage solution may either violate the reentrant flow conditions or it may create a deadlock. In order to alleviate these infeasibilities, we develop feasibility cuts which when appended to the master problem eliminate the infeasible solution. Alternatively, we also develop constraints to explicitly address these infeasibilities directly within the master problem. We show how a deadlock involving 2 or 3 machines arises if and only if a certain relationship between operations and a certain sequence amongst them exists. We generalize this argument to the case of m machines, which forms the basis for our deadlock prevention constraints. Computational results at the end of Chapter 3 compare the relative merits of a model which relies solely on feasibility cuts with models that incorporate reentrant flow and deadlock prevention constraints within the master problem. Experimental evidence reveals that the latter offers appreciable time savings over the former. Moreover, in a majority of instances we see that models that carry deadlock prevention constraints in addition to the reentrant flow constraints provide at par or better performance than those that solely carry reentrant flow constraints. We, next, develop an optimality cut which when appended to the master problem helps in eliminating the suboptimal master solution. We also present alternative optimality and feasibility cuts obtained by modifying the disjunctive constraints in the subproblem so as to eliminate the big H terms in it. Although any large positive number can be used as the value of H, a conservative estimate may improve computational performance. In light of this, we develop a conservative upper bound for operation completion times and use it as the value of H. Test instances have been generated using a problem generator written in JAVA. We present computational results to evaluate the impact of a conservative estimate for big H on run time, analyze the effect of the different optimality cuts and demonstrate the performance of the multicut method (Wets, 1981) which differs from the L-shaped method in that the number of optimality cuts it appends is equal to the number of scenarios in each iteration. Experimentation indicates that Model 2, which uses the standard optimality cut in conjunction with the conservative estimate for big H, almost always outperforms Model 1, which also uses the standard optimality cut but uses a fixed value of 1000 for big H. Model 3, which employs the alternative optimality cut with the conservative estimate for big H, requires the fewest number of iterations to converge to the optimum but it also incurs the maximum premium in terms of computational time. This is because the alternative optimality cut adds to the complexity of the problem in that it appends additional variables and constraints to the master as well as the subproblems. In the case of Model 4 (multicut method), the segregated optimality cuts accurately reflect the shape of the recourse function resulting in fewer overall iterations but the large number of these cuts accumulate over the iterations making the master problem sluggish and so this model exhibits a variable performance for the various datasets. These experiments reveal that a compact master problem and a conservative estimate for big H positively impact the run time performance of a model. Finally, we develop a framework for a branch-and-bound scheme within which the L-shaped method, as applied to the NMJS problem, can be incorporated so as to further enhance its performance. Our second approach for solving the stochastic NMJS problem relies on the tight LP relaxation observed for the deterministic equivalent of the model. We, first, solve the LP relaxation of the deterministic equivalent problem, and then, fix certain binary assignment variables that take on a value of either a 0 or a 1 in the relaxation. Based on this fixing of certain assignment variables, additional logical constraints have been developed that lead to the fixing of some of the sequencing variables too. Experimental results, comparing the performance of the above LP heuristic procedure with CPLEX over the generated test instances, illustrate the effectiveness of the heuristic procedure. For the largest problems (5 jobs, 10 operations/job, 12 machines, 7 workcenters, 7 scenarios) solved in this experiment, an average savings of as much as 4154 seconds and 1188 seconds was recorded in a comparison with Models 1 and 2, respectively. Both of these models solve the deterministic equivalent of the stochastic NMJS problem but differ in that Model 1 uses a big H value of 1000 whereas Model 2 uses the conservative upper bound for big H developed in this work. The maximum optimality gap observed for the LP heuristic over all the data instances solved was 1.35%. The LP heuristic, therefore, offers a powerful alternative to solving these problems to near-optimality with a very low computational burden. We also present results pertaining to the value of the stochastic solution for various data instances. The observed savings of up to 8.8% over the mean value approach underscores the importance of using a solution that is robust over all scenarios versus a solution that approximates the randomness through expected values. We, next, present a dynamic stochastic scheduling approach (DSSP) for the NMJS problem. The premise behind this undertaking is that in a real-life implementation that is faithful to the two-stage procedure, assignment (routing) and sequencing decisions will be made for all the operations of all the jobs at the outset and these will be followed through regardless of the actual processing times realized for individual operations. However, it may be possible to refine this procedure if information on actual processing time realizations for completed operations could be utilized so that assignment and sequencing decisions for impending operations are adjusted based on the evolving scenario (which may be very different from the scenarios modeled) while still hedging against future uncertainty. In the DSSP approach, the stochastic programming model for the NMJS problem is solved at each decision point using the LP heuristic in a rolling horizon fashion while incorporating constraints that model existing conditions in the shop floor and the actual processing times realized for the operations that have been completed. The implementation of the DSSP algorithm is illustrated through an example problem. The results of the DSSP approach as applied to two large problem instances are presented. The performance of the DSSP approach is evaluated on three fronts; first, by using the LP heuristic at each decision point, second, by using an optimal algorithm at each decision point, and third, against the two-stage stochastic programming approach. Results from the experimentation indicate that the DSSP approach using the LP heuristic at each decision point generates superior assignment and sequencing decisions than the two-stage stochastic programming approach and provides solutions that are near-optimal with a very low computational burden. For the first instance involving 40 operations, 12 machines and 3 processing time scenarios, the DSSP approach using the LP heuristic yields the same solution as the optimal algorithm with a total time savings of 71.4% and also improves upon the two-stage stochastic programming solution by 1.7%. In the second instance, the DSSP approach using the LP heuristic yields a solution with an optimality gap of 1.77% and a total time savings of 98% over the optimal algorithm. In this case, the DSSP approach with the LP heuristic improves upon the two-stage stochastic programming solution by 6.38%. We conclude by presenting a framework for the DSSP approach that extends the basic DSSP algorithm to accommodate jobs whose arrival times may not be known in advance. / Ph. D.

No / The work was funded by the Leeds Social Science Institute.

Yes / This article considers how cuts in Government funding will affect continuing professional development and mentorship training for NHS staff

As infecções causadas por Campylobacter spp. são relatadas como causa freqüente de gastrenterites de origem alimentar em vários países do mundo. As espécies bacterianas termofílicas pertencentes ao gênero Campylobacter, principalmente Campylobacter jejuni e Campylobacter coli, têm sido isoladas de fezes de animais e estão associadas à contaminação da carne durante o processo de abate. Estas duas espécies são as mais freqüentemente envolvidas nos casos de campilobacteriose humana veiculada por alimentos. O presente estudo pretendeu avaliar a presença e a população de Campylobacter spp. no abate de bovinos e cortes refrigerados de aves e bovinos comercializados na cidade de São Paulo/SP. Um total de 198 animais foi amostrado no couro logo após a sangria, na carcaça imediatamente após a esfola e após a evisceração. As amostras foram obtidas através da técnica de swab na região do peito abrangendo uma área de 400 cm2. Foram analisados também 120 cortes refrigerados de frango e 100 cortes de carne bovina, assim distribuídos: 40 amostras de asa, 20 de coxa com sobrecoxa, 20 de coxa, 20 de coxinha da asa, 20 amostras de peito; 20 de patinho bovino (M. biceps femoris), 20 de contrafilé (M. longissimus dorsi), 20 de coxão mole (M. semi membranosus), 20 de lagarto (M. semitendinosus) e 20 de alcatra (M. glutaes medius). As amostras foram analisadas segundo os métodos ISO 10272-1 e 2 e os isolados obtidos foram confirmados como Campylobacter pela técnica de PCR. Campylobacter foi isolado em 22,7% (45/198) das amostras de couro bovino, ou seja, apenas no ponto antes da esfola, e C. jejuni foi a única espécie encontrada. Nas amostras de cortes de frango Campylobacter foi isolado em 14,2% (17/120) das amostras. A espécie prevalente em frangos foi C. coli (88%), seguido de C. jejuni (12%). Campylobacter spp. não foi isolado dos cortes bovinos. A população de Campylobacter spp. foi < 13 UFC/cm2 em carcaças bovinas, < 2 UFC/g em amostras de frango e < 10 UFC/cm2 em cortes bovinos. A susceptibilidade de 120 isolados de frango e couro bovino foi determinada frente a 8 agentes antimicrobianos usando o método de disco-difusão. A resistência às quinolonas (ác. nalidíxico e ciprofloxacina) foi frequentemente observada nas cepas de C. jejuni (72,2%) e C. coli (50,8%) isoladas dos frangos. Entre os isolados de C. jejuni obtidos do couro bovino maior taxa de resistência foi observada para estreptomicina (32%), seguida da eritromicina (16%) e do ácido nalidíxico (14%). / Campylobacter spp. infections are reported as a frequent cause of foodborne gastroenteritis in many countries. The thermophilic bacterial species belonging to the genus Campylobacter, particularly Campylobacter jejuni and Campylobacter coli have been isolated from feces of animals and are associated with the contamination of meat during the slaughtering process. These two species are the most frequently involved in cases of human campylobacteriosis conveyed by food. The aim of the present study was to evaluate the presence and population of Campylobacter spp. during cattle slaughter and in refrigerated chicken and beef cuts commercialized in the city of Sao Paulo/SP. A total of 198 animals were sampled in the hide after bleeding, the carcass immediately after skinning and after evisceration. Samples were obtained by swab technique in the chest area encompassing an area of 400 cm2. We also analyzed 120 refrigerated chicken cuts and 100 beef cuts. The samples were analyzed according to ISO 10272-1 and 2 methods and the isolates were confirmed as Campylobacter by PCR technique. Campylobacter was isolated only in the hide samples (45/198), and C. jejuni was the only species found. Campylobacter was isolated in 14.2% (17/120) of chicken samples. The most prevalent species in chickens was C. coli (88%), followed by C. jejuni (12%). Campylobacter spp. was not isolated from beef cuts. The counts of Campylobacter spp. was < 13 CFU/cm2 in bovine carcasses, < 2 CFU/g in chicken samples and < 10 CFU/cm2 in beef cuts. The susceptibility to 8 antimicrobial agents of 120 isolates of chicken and bovine hide was determined using the disk-diffusion method. The resistance to quinolones (ciprofloxacin and nalidixic acid) was frequently observed in strains of C. jejuni (72.2%) and C. coli (50.8%) isolated from chickens. Among strains of C. jejuni obtained from bovine hide highest resistance rate was observed to streptomycin (32%), followed by erythromycin (16%) and nalidixic acid (14%).

As infecções causadas por Campylobacter spp. são relatadas como causa freqüente de gastrenterites de origem alimentar em vários países do mundo. As espécies bacterianas termofílicas pertencentes ao gênero Campylobacter, principalmente Campylobacter jejuni e Campylobacter coli, têm sido isoladas de fezes de animais e estão associadas à contaminação da carne durante o processo de abate. Estas duas espécies são as mais freqüentemente envolvidas nos casos de campilobacteriose humana veiculada por alimentos. O presente estudo pretendeu avaliar a presença e a população de Campylobacter spp. no abate de bovinos e cortes refrigerados de aves e bovinos comercializados na cidade de São Paulo/SP. Um total de 198 animais foi amostrado no couro logo após a sangria, na carcaça imediatamente após a esfola e após a evisceração. As amostras foram obtidas através da técnica de swab na região do peito abrangendo uma área de 400 cm2. Foram analisados também 120 cortes refrigerados de frango e 100 cortes de carne bovina, assim distribuídos: 40 amostras de asa, 20 de coxa com sobrecoxa, 20 de coxa, 20 de coxinha da asa, 20 amostras de peito; 20 de patinho bovino (M. biceps femoris), 20 de contrafilé (M. longissimus dorsi), 20 de coxão mole (M. semi membranosus), 20 de lagarto (M. semitendinosus) e 20 de alcatra (M. glutaes medius). As amostras foram analisadas segundo os métodos ISO 10272-1 e 2 e os isolados obtidos foram confirmados como Campylobacter pela técnica de PCR. Campylobacter foi isolado em 22,7% (45/198) das amostras de couro bovino, ou seja, apenas no ponto antes da esfola, e C. jejuni foi a única espécie encontrada. Nas amostras de cortes de frango Campylobacter foi isolado em 14,2% (17/120) das amostras. A espécie prevalente em frangos foi C. coli (88%), seguido de C. jejuni (12%). Campylobacter spp. não foi isolado dos cortes bovinos. A população de Campylobacter spp. foi < 13 UFC/cm2 em carcaças bovinas, < 2 UFC/g em amostras de frango e < 10 UFC/cm2 em cortes bovinos. A susceptibilidade de 120 isolados de frango e couro bovino foi determinada frente a 8 agentes antimicrobianos usando o método de disco-difusão. A resistência às quinolonas (ác. nalidíxico e ciprofloxacina) foi frequentemente observada nas cepas de C. jejuni (72,2%) e C. coli (50,8%) isoladas dos frangos. Entre os isolados de C. jejuni obtidos do couro bovino maior taxa de resistência foi observada para estreptomicina (32%), seguida da eritromicina (16%) e do ácido nalidíxico (14%). / Campylobacter spp. infections are reported as a frequent cause of foodborne gastroenteritis in many countries. The thermophilic bacterial species belonging to the genus Campylobacter, particularly Campylobacter jejuni and Campylobacter coli have been isolated from feces of animals and are associated with the contamination of meat during the slaughtering process. These two species are the most frequently involved in cases of human campylobacteriosis conveyed by food. The aim of the present study was to evaluate the presence and population of Campylobacter spp. during cattle slaughter and in refrigerated chicken and beef cuts commercialized in the city of Sao Paulo/SP. A total of 198 animals were sampled in the hide after bleeding, the carcass immediately after skinning and after evisceration. Samples were obtained by swab technique in the chest area encompassing an area of 400 cm2. We also analyzed 120 refrigerated chicken cuts and 100 beef cuts. The samples were analyzed according to ISO 10272-1 and 2 methods and the isolates were confirmed as Campylobacter by PCR technique. Campylobacter was isolated only in the hide samples (45/198), and C. jejuni was the only species found. Campylobacter was isolated in 14.2% (17/120) of chicken samples. The most prevalent species in chickens was C. coli (88%), followed by C. jejuni (12%). Campylobacter spp. was not isolated from beef cuts. The counts of Campylobacter spp. was < 13 CFU/cm2 in bovine carcasses, < 2 CFU/g in chicken samples and < 10 CFU/cm2 in beef cuts. The susceptibility to 8 antimicrobial agents of 120 isolates of chicken and bovine hide was determined using the disk-diffusion method. The resistance to quinolones (ciprofloxacin and nalidixic acid) was frequently observed in strains of C. jejuni (72.2%) and C. coli (50.8%) isolated from chickens. Among strains of C. jejuni obtained from bovine hide highest resistance rate was observed to streptomycin (32%), followed by erythromycin (16%) and nalidixic acid (14%).

O objetivo do presente estudo foi avaliar o desempenho, características de carcaça e qualidade de carne de bovinos Nelore com diferentes potenciais genéticos para crescimento pós-desmama pela diferença esperada na progênie (DEP). Foram utilizados 147 machos não-castrados da raça Nelore, com peso corporal médio inicial de 412 ± 54kg e média de idade de 19 meses, provenientes de recria em sistema de pastejo contínuo. Os animais foram distribuídos em um delineamento inteiramente casualizado e divididos dois tratamentos em função do potencial genético para crescimento: 1) alta taxa de crescimento (TC+) representada pela média de 11,50 kg e 2) baixa taxa de crescimento (TC-) representada pela média de -1,0 kg. Os animais foram confinados por um período de 100 dias, sendo os primeiros 21 dias de adaptação à dieta e as instalações. A dieta continha 73% de concentrado e 27% de volumoso (silagem de milho). No início do período experimental e a cada 28 dias todos os animais foram pesados e submetidos a avaliações de ultrassonografia. A ingestão de matéria seca foi avaliada diariamente, para ajuste da oferta e avaliação da eficiência alimentar. Ao fim do período de confinamento, todos animais foram abatidos, o peso de carcaça quente e a gordura pélvica, renal e inguinal foram pesados. Após 24 horas, foi avaliado o pH final e a meia carcaça esquerda foi seccionada entre a 12ª e 13ª costelas. As meias carcaças seguiram para desossa completa para análise de rendimentos dos cortes cárneos comerciais, em seguida amostras foram retiradas do contrafilé para posterior análise de cor, perdas de peso por cozimento, força de cisalhamento, comprimento de sarcômero e análise sensorial. Houve efeito da TC sobre o peso corporal final (P = 0,04), sendo que os animais de alta TC apresentaram maiores pesos. Não houve efeito da TC para AOL, EGS e espessura de gordura da picanha (Biceps femoris) avaliados pela ultrassonografia; no entanto, houve diferença significativa para o período de coleta das imagens (P &lt; 0,05). Com relação ao rendimento dos cortes cárneos comerciais, animais de alta TC tiveram a ponta de peito (P = 0,01) e músculo traseiro (P = 0,07) mais pesados em relação aos animais de baixa TC. A DEP não influenciou a qualidade das características sensoriais da carne dos animais exceto para a cor, sendo que os valores de L* (P = 0,03) foram maiores para animais de baixa TC, no entanto, os maiores valores de a* (P = 0,06) foram expressados pelo grupo de alta TC. Além disso, para todas as variáveis de qualidade, houve efeito do tempo de maturação (P &gt; 0,05). Em conclusão, o potencial genético para o crescimento pós-desmama não afetou a maioria das características, incluindo desempenho, produção de carne e qualidade no final do período de terminação. / The aim of this study was to evaluated the performance, carcass characteristics and meat quality of Nellore young bulls with different genetics potentials for post-weaning growth for expected progeny differences (EPD\'s). A total of 147 Nellore bulls with average initial body weight (412 ± 54kg) and 19 months old, were distributed in a completely randomized design and divided into two groups according with growth rate: 1) high growth rate (GR+) represented by the mean of 11.50 kg and 2) low growth rate (GR-) represented by the average of -1.0 kg . The animals were in a feedlot system for a total 100 days, with the first 21 days of adaptation to the diet and facilities. The finishing diet was composed by 73 % concentrate and 27 % corn silage. At the beginning of the experimental period and every 28 days all animals were weighed and submitted to ultrasound evaluations. Dry matter intake was measured daily. At the end of the feedlot period, all animals were slaughtered and the hot carcass weigth and internal fat were recorded. After 24 hours, the final pH was evaluated and the left half carcass was sectioned between the 12 th and 13 th ribs. The half carcass was completely deboning to analyze the wholesale cuts. In addition, longissimus was sampled to analyze color, cooking loss, tenderness, sarcomere length and sensory property. There was an effect of GR on the final body weight (P = 0.04), where the group of animals with high EPD presented higher weights. There was no effect of GR for longissimus muscle area (LMA), fat thickness (FAT) and rump fat (Biceps femoris) evaluated by ultrasonography; however, there was a significant difference for the collection period (P &gt; 0.05). Regarding the wholesale cuts, animals of higher GR had the heavier (P = 0.01) and hind muscle (P = 0.07) weights than the animals of lower GR. The GR did not influence the quality sensory characteristics of the meat of the animals except for the color, and the values of L* (P = 0.03) were higher for animals with low GR, however, the highest values of a* (P = 0.06) were expressed by the high GR group. In addition, for all quality variables, there was an effect of maturation time (P &gt; 0.05). In conclusion, the potential genetic for growth measured post-weaning did not affect most traits, including performance, meat production and quality at the end of finishing period.

Atualmente os supermercados vêm utilizando para a exposição de carnes frescas, bandejas rígidas revestidas de filmes plásticos permeáveis a gases. Esse sistema protege a superfície da carne de possíveis contaminações e permite a seleção dos cortes pelo consumidor. No entanto, essa forma de acondicionamento limita a vida útil da carne, especialmente dos cortes com osso. Dessa maneira, o presente trabalho de pesquisa objetivou estudar a interação entre as diferentes tecnologias - embalagem com atmosfera modificada, ácidos orgânicos e antioxidante - aplicando-se diferentes concentrações de dióxido de carbono (CO2) combinado com o nitrogênio (N2) e monóxido de carbono (CO) (composições gasosas: C1: 99,6%CO2/0,4CO; C2: 19,6%N2/80%CO2/0,4%CO; C3: 49,6%N2/50%CO2/0,4%CO e C4: 50%CO2/50%N2;) e seus efeitos nas características físico-químicas, sensoriais e microbiológicas de bisteca e de costela suína, armazenadas a temperatura de 2+ 2 ºC por um período de 32 dias. Após a obtenção dos referidos cortes na sala de desossa, metade foram pulverizados com a solução de ácidos orgânicos (1% de ácido acético, 1% de ácido lático e 1% de ácido cítrico) e antioxidante (0,8% de ácido ascórbico), e a outra metade não foi pulverizada. A seguir, as amostras pulverizadas ou não, foram colocadas em bandejas plásticas rígidas dentro de saco-filme impermeável a gases. O conjunto, produto mais bandeja foi submetido a três diferentes misturas gasosas, sendo C1, C2 e C3 para costela e C2, C3 e C4 para bisteca. Foram realizadas avaliações físico-químicas, microbiológicas e sensoriais nos 0 (caracterização da matéria-prima), 1º, 5º, 13º, 19º, 25º e 32º dias. Concluiu-se que o uso das composições gasosas: 19,6%N2/80%CO2/0,4%CO e 49,6%N2/50%CO2/0,4%CO, para a bisteca, e a três composições para costela, mantiveram a estabilidade da cor visual e instrumental da carne, do osso e da gordura durante todo o período de estudo. O odor foi predominantemente ácido em todas as amostras desde o primeiro dia de análise. As concentrações de CO2 usadas não foram efetivas na redução das contagens microbianas devido a elevada carga microbiana inicial da matéria-prima. Houve prevalência de bactérias láticas em todas as amostras após o 19º dia, e a vida útil foi de no mínimo 13 dias para todos os tratamentos. / Supermarkets have been using rigid trays covered with gas permeable films to expose fresh meat. This system keeps the meat surface free from contamination and allows the consumer choice, although this type of packaging shortens the meat shelf life, especially cuts with bone in. Thus, the aim of the present was to evaluate the interaction among the followed different technologies: modified atmosphere and spraying of organic acids with antioxidants solution in the meat surface. The effect of four types of modified atmosphere containing different carbon dioxide concentrations combined with nitrogen (N2) and carbon monoxide (CO) (C1: 99,6%CO2/0,4CO; C2: 19,6%N2/80%CO2/0,4%CO; C3: 49,6%N2/50%CO2/0,4%CO e C4: 50%CO2/50%N2) on physical, chemical, sensory and microbiological characteristics were evaluated in portioned pork chops and pork ribs stored during 32 days in a cooling chamber at 2+ 2 ºC. Half of the cuts obtained from the carcasses deboned at CTC were randomly assigned for spraying with a solution containing acetic acid (1%), lactic acid (1%), citric acid (1%) and ascorbic acid (0,8%) while the rest was not sprayed. Following, the samples were packaged in rigid plastic trays covered with impermeable film/bag and subjected to three different atmospheres (pork chops - C1, C2 and C3 and pork ribs - C2, C3 and C4). During storage the physical, chemical, microbiological and sensory evaluations were conducted in the following periods: 0 (raw material), 1, 5, 13, 19, 25 e 32 days. It was concluded that the use of following gas composition: 19,6%N2/80%CO2/0,4%CO and 49,6%N2/50%CO2/0,4%CO kept the color stability for pork chops and the three compositions for pork ribs, either subjective or objective, of the meat, bone and fat during all the period of the experiment. The odor was acid in all samples from the first day of analysis. The percentages of CO2 used in the experiment were not effective to reduce bacterial count because the raw material had high initial count. There was prevalence of lactic acid bacteria in all samples after the 19º day and shelf life was at least 13 days for all treatments.

Resumo: Objetivou-se comparar genótipos de suínos relativos ao desempenho, parâmetros e características de carcaça e da carne em animais abatidos aos 161 dias de idade. Utilizaram-se os seguintes genótipos: G1 - ½ Topigs© (Toppi) x ½ Naïma®; G2 - ½ DB Danbred© (Frederik) x ½ Naïma®; G3 - ½ PIC© (AGPIC 412) x ½ Naïma®; G4 - ½ SG 2030© (Duroc) x ½ Naïma®; e G5 - ½ Pen Ar Lan© (P76) x ½ Naïma®. Estudaram-se o ganho de peso total (GPT), consumo de ração total (CRT), conversão alimentar (CA) e eficiência alimentar (EA). As meias carcaças esquerdas foram, inicialmente, avaliadas quanto ao peso da carcaça quente (PCQ) e fria (PCF), comprimento (CC), área do olho de lombo (AOL), comprimento de olho do lombo (COL) e profundidade do toucinho (PT10ª). Foram feitas ainda, com a pistola de tipificação eletrônica Hennessy, medidas de espessura do músculo (EM1 e EM2) e profundidade do toucinho (PT1 e PT2). Foram feitas medidas de espessura de toucinho na altura da primeira costela (ET1), última costela (ET2), última lombar (ET3) e máxima lombar (ETM), com o auxílio de paquímetro digital. A carcaça foi desdobrada em seus cortes primários: pernil, carré, barriga, barriga ventral, fraldinha, paleta, sobre paleta, ponta do peito, filezinho, antebraço, perna e papada. Após a pesagem desses cortes, foi realizada a desossa dos mesmos, para se determinar os pesos da carne, gordura interna, ossos, pele e gordura subcutânea de cada um. A porcentagem de carne magra (PCM) foi determinada dividindo-se o total de carne magra desossada pelo peso da carcaça fria. Foram estudados os seguintes parâmetros físico-químicos da carne: pH post-mortem, perda de líquido por gotejamento, cor da carne, ...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this work it was to compare different swine genotypes with the performance, characteristics of carcass and meat quality in swine slaughtered at 161 days of age. The following genotypes had been used: G1 - ½ Topigs© (Toppi) x ½ Naïma©; G2 - ½ DB Danbred© (Frederik) x ½ Naïma©; G3 - ½ PIC© (AGPIC 412) x ½ Naïma©; G4 - ½ SG 2030© (Duroc) x ½ Naïma©; e G5 - ½ Pen Ar Lan© (P76) x ½ Naïma©. They had been studied the profit of all up weight (BW), consumption of total ration (CTR), feed conversion (FC) and alimentary efficiency (AE). The half left carcasses had been, initially, evaluated to the hot carcass weight (HCW) and cold weight (CCW), carcass length (CL), loin eye area (LEA), loin eye length (LEL) and backfat thickness in tenth rib (BT10th). They had been made still, with the pistol electronic Hennessy, measures of muscle depth (MD1 and MD2) and fat depth (FD1 and FD2). Backfat thickness was measured at four locations: in the first rib (BT1), last rib (BT2), last lumbar (BT3) and maximum lumbar (BTM), with digital paquimeter. The carcass was unfolded in these cuts: ham, loin, belly, ventral belly, cranial belly, shoulder, neck, jowl, tenderloin, front shank, hind shank and cheek. After the weight of these cuts, the composition of each one was determined by physical dissection into lean, fat, bone, and skin. The lean meat percentage (LMP) was determined, dividing the total of boned lean meat by the weight of the cold carcass. The following parameters had been studied in the meat: pH post-mortem, ...(Complete abstract click electronic access below) / Orientador: Jeffrey Frederico Lui / Coorientador: Expedito Tadeu Facco Silveira / Banca: Pedro Eduardo de Felício / Banca: Roberto de Oliveira Roça / Banca: Otto Mack Junqueira / Banca: Hirasilva Borba Alves de Souza / Doutor

The aim in this thesis is to develop efficient enumeration algorithms to solve certain strongly NP-hard scheduling problems. These algorithms were developed using a combination of ideas from Integer Programming, Constraint Programming and Scheduling Theory. In order to combine different techniques in one algorithm, decomposition methods are applied. The main idea on which the first part of our results is based is to separate the optimality and feasibility components of the problem and let different methods tackle these components. Then IP is ``responsible' for optimization, whereas specific combinatorial algorithms tackle the feasibility aspect. Branch-and-cut and branch-and-price algorithms based on this idea are proposed to solve the single-machine and multi-machine variants of the scheduling problem to minimize the sum of the weights of late jobs. Experimental research shows that the algorithms proposed outperform other algorithms available in the literature. Also, it is shown that these algorithms can be used, after some modification, to solve the problem of minimizing the maximum tardiness on unrelated machines. The second part of the thesis deals with the one-machine scheduling problem to minimize the weighted total tardiness. To tackle this problem, the idea of a partition of the time horizon into intervals is used. A particularity of this approach is that we exploit the structure of the problem to partition the time horizon. This particularity allowed us to propose two new Mixed Integer Programming formulations for the problem. The first one is a compact formulation and can be used to solve the problem using a standard MIP solver. The second formulation can be used to derive lower bounds on the value of the optimal solution of the problem. These lower bounds are of a good quality, and they can be obtained relatively fast.

The current economic situation in the U.S. has demanded budget cuts in all areas of American life, including education. Faced with these unprecedented cuts, many arts programs are losing their funding. Many art educators are finding it a challenge to provide art education without compromising the quality of the curriculum and program. Through a comparative analysis of materials and fundraisers and a document analysis of money saving tips, strategies are suggested for art teachers to save and find money.