Evaluation and improvement of total transfer capability - A case study

With deregulation, the total transfer capability (TTC) calculation, which is the basis for evaluating available transfer capability (ATC), has become very significant. TTC is an important index in power markets with large volume of inter-area power exchanges and wheeling transactions taking place on an hourly basis. Its computation helps to achieve a viable technical and commercial transmission operation. The aim of the paper is to evaluate TTC in the interconnections and also to improve it using reactive optimization technique and UPFC devices. Computations are carried out for normal and contingency cases such as single line, tie line and generator outages. Base and optimized results are presented, and the results show how reactive optimization and unified power flow controller help to improve the system conditions. In this paper repeated power flow method is used to calculate TTC due to its ease of implementation. A case study is carried out on a 205 bus equivalent system, a part of Indian Southern grid. Parameters like voltage magnitude, L-index, minimum singular value and MW losses are computed to analyze the system performance.

Performance evaluation of nonthermal plasma reactors for NO oxidation in diesel engine exhaust gas treatment

The discharge plasma-chemical hybrid process for NOinfinity removal from the flue gas emissions is an extremely effective and economical approach in comparison with the conventional selective catalytic reduction system. In this paper we bring out a relative comparison of several discharge plasma reactors from the point of NO removal efficiency. The reactors were either energized by ac or by repetitive pulses. Ferroelectric pellets were used to study the effect of pellet assisted discharges on gas cleaning. Diesel engine exhaust, at different loads; is used to approximately simulate the flue gas composition. Investigations were carried out at room temperature with respect to the variation of reaction products against the discharge power. Main emphasis is laid on the oxidation of NO to NO2, without reducing NOx concentration (i.e., minimum reaction byproducts), with least power consumption. The produced NO2 will be totally converted to N-2 and Na-2 SO4 using Na-2 SO3. The ac packed-bed reactor and pelletless pulsed corona reactor showed better performance, with minimum reaction products for a given power, when the NO concentration was low (similar to 100 ppm). When the engine load exceeds 50% (NO > 300 ppm) there was not much decrease in NO reduction and more or less all the reactors performed equally. The total operating cost of the plasma-chemical hybrid system becomes $4010/ton of NO, which is 1/3-1/5 of the conventional selective catalytic process.

Command Tracking in High Performance Aircrafts: A New Dynamic Inversion Design

This paper proposes a new straight forward technique based on dynamic inversion, which is applied for tracking the pilot commands in high performance aircrafts.Pilot commands assumed in longitudinal mode are normal acceleration and total velocity(while roll angle and lateral acceleration are maintained at zero). In lateral mode, roll rate and total velocity are used as pilot commands (while climb rate and lateral acceleration are maintained at zero). Ensuring zero lateral acceleration leads to a better turn co-ordination. A six degree-of-freedom model of F-16 aircraft is used for both control design as well as simulation studies. Promising results are obtained which are found to be superior as compared to an existing approach (which is also based on dynamic inversion). The new approach has two potential benefits, namely reduced oscillatory response and reduced control magnitude. Another advantage of this approach is that it leads to a significant reduction of tuning parameters in the control design process.

Scheduling identical parallel machines with machine eligibility restrictions to minimize total weighted flowtime in automobile gear manufacturing

In this paper, we address a scheduling problem for minimizing total weighted flowtime, observed in automobile gear manufacturing. Specifically, the bottleneck operation of the pre-heat treatment stage of gear manufacturing process has been dealt with in scheduling. Many real-life scenarios like unequal release times, sequence dependent setup times, and machine eligibility restrictions have been considered. A mathematical model taking into account dynamic starting conditions has been proposed. The problem is derived to be NP-hard. To approach the problem, a few heuristic algorithms have been proposed. Based on planned computational experiments, the performance of the proposed heuristic algorithms is evaluated: (a) in comparison with optimal solution for small-size problem instances and (b) in comparison with the estimated optimal solution for large-size problem instances. Extensive computational analyses reveal that the proposed heuristic algorithms are capable of consistently yielding near-statistically estimated optimal solutions in a reasonable computational time.

Antitumor and antioxidant status of Terminalia catappa against Ehrlich ascites carcinoma in Swiss albino mice

Objective: The present study was undertaken to evaluate the antitumor and antioxidant status of ethanol extract of Terminalia catappa leaves against Ehrlich ascites carcinoma (EAC) in Swiss albino mice. Materials and Methods: The leaves powder was extracted with Soxhlet apparatus and subjected to hot continuous percolation using ethanol (95% v/v). Tumor bearing animals was treated with 50 and 200 mg/kg of ethanol extract. EAC induced in mice by intraperitoneal injection of EAC cells 1 x 10(6) cells/mice. The study was assed using life span of EAC-bearing hosts, hematological parameters, volume of solid tumor mass and status of antioxidant enzymes such as lipid peroxidation (LPO), reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) activities. Total phenolics and flavonoids contents from the leaves extract were also determined. Results: Total phenolics and flavonoids contents from the leaves extract were found 354.02 and 51.67 mg/g extract. Oral administration of ethanol extract of T. catappa (50 and 200 mg/kg) increased the life span (27.82% and 60.59%), increased peritoneal cell count (8.85 +/- 0.20 and 10.37 +/- 0.26) and significantly decreased solid tumor mass (1.16 +/- 0.14 cm(2)) at 200 mg/kg as compared with EAC-tumor bearing mice (P < 0.01). Hematological profile including red blood cell count, white blood cell count, hemoglobin (11.91 +/- 0.47 % g) and protein estimation were found to be nearly normal levels in extract-treated mice compared with tumor bearing control mice. Treatment with T. catappa significantly decreased levels of LPO and GSH, and increased levels of SOD and CAT activity (P < 0.01). Conclusion: T. catappa exhibited antitumor effect by modulating LPO and augmenting antioxidant defense systems in EAC bearing mice. The phenolic and flavonoid components in this extract may be responsible for antitumor activity.

Minimizing total weighted tardiness on heterogeneous batch processors with incompatible job families

In this paper, we address a scheduling problem for minimizing total weighted tardiness. The background for the paper is derived from the automobile gear manufacturing process. We consider the bottleneck operation of heat treatment stage of gear manufacturing. Real-life scenarios like unequal release times, incompatible job families, nonidentical job sizes, heterogeneous batch processors, and allowance for job splitting have been considered. We have developed a mathematical model which takes into account dynamic starting conditions. The problem considered in this study is NP-hard in nature, and hence heuristic algorithms have been proposed to address it. For real-life large-size problems, the performance of the proposed heuristic algorithms is evaluated using the method of estimated optimal solution available in literature. Extensive computational analyses reveal that the proposed heuristic algorithms are capable of consistently obtaining near-optimal statistically estimated solutions in very reasonable computational time.

Matrix-Assisted Refolding, Purification and Activity Assessment Using a `Form Invariant' Assay for Matrix Metalloproteinase 2 (MMP2)

Matrix metalloproteinases expression is used as biomarker for various cancers and associated malignancies. Since these proteinases can cleave many intracellular proteins, overexpression tends to be toxic; hence, a challenge to purify them. To overcome these limitations, we designed a protocol where full length pro-MMP2 enzyme was overexpressed in E. coli as inclusion bodies and purified using 6xHis affinity chromatography under denaturing conditions. In one step, the enzyme was purified and refolded directly on the affinity matrix under redox conditions to obtain a bioactive protein. The pro-MMP2 protein was characterized by mass spectrometry, CD spectroscopy, zymography and activity analysis using a simple in-house developed `form invariant' assay, which reports the total MMP2 activity independent of its various forms. The methodology yielded higher yields of bioactive protein compared to other strategies reported till date, and we anticipate that using the protocol, other toxic proteins can also be overexpressed and purified from E. coli and subsequently refolded into active form using a one step renaturation protocol.

Synthesis and antioxidant activity study of pyrazoline carrying an arylfuran/arylthiophene moiety

A novel series of N-acetyl-3-aryl-5-(5-(p/o-nitrophenyl)-2-furyl//thienyl)-substituted pyrazolines (3a-o) were synthesized by the reaction of 1-aryl-3-(5-(p/o-nitrophenyl)-2-furyl/thienyl)-2-propene-1-ones with hydrazine hydrate in acetic acid medium. The structures of the newly synthesized compounds were established by IR, H-1-NMR, mass spectra and a single-crystal X-ray study. The antioxidant activities of the synthesized compounds were determined using the DPPH scavenging assay. The compounds 3a, 3f, 3h and 3o showed moderate activity.

Investigations on Optimal Pulse-Width Modulation to Minimize Total Harmonic Distortion in the Line Current

PWM waveforms with positive voltage transition at the positive zero crossing of the fundamental voltage (type-A) are generally considered for PWM waveform with even number of switching angles per quarter whereas, waveforms with negative voltage transition at the positive zero crossing (type-B) are considered for odd number of switching angles per quarter. Optimal PWM, for minimization of total harmonic distortion of line to line (VWTHD), is generally solved with the aforementioned criteria. This paper establishes that a combination of both types of waveforms gives better performance than any individual type in terms of minimum VWTHD for complete range of modulation index (M). Optimal PWM for minimum VWTHD is solved for PWM waveforms with pulse numbers (P) of 5 and 7. Both type-A and type-B waveforms are found to be better in different ranges of M. The theoretical findings are confirmed through simulation and experimental results on a 3.7 kW squirrel cage induction motor in an open-loop V/f drive. Further, the optimal PWM is analysed from a space vector point of view.

An enzyme-linked immuno focus assay for rapid detection and enumeration, and a newborn mouse model for human non-polio enteroviruses associated with acute diarrhea

We have recently reported significant association of non-polio enteroviruses (NPEVs) with acute and persistent diarrhea (18-21% of total diarrheal cases), and non-diarrheal Increased Frequency of Bowel Movements (IFoBM-ND) (about 29% of the NPEV infections) in children and that the NPEV-associated diarrhea was as significant as rotavirus diarrhea. However, their diarrhea-causing potential is yet to be demonstrated in an animal model system. Since the determination of virus titers by the traditional plaque assay takes 4-7 days, there is a need for development of a rapid method for virus titer determination to facilitate active clinical research on enterovirus-associated diarrhea. The goal of this study is to develop a cell-based rapid detection and enumeration method and to demonstrate the diarrhea-inducing potential of purified and characterized non-polio enteroviruses, which were isolated from diarrheic children. Here we describe generation of monoclonal and polyclonal antibodies against purified strains belonging to different serotypes, and development of an enzyme-linked immuno focus assay (ELIFA) for detection and enumeration of live NPEV particles in clinical and purified virus samples, and a newborn mouse model for NPEV diarrhea. Plaque-purified NPVEs, belonging to different serotypes, isolated from children with diarrhea, were grown in cell culture and purified by isopycnic CsCl density gradient centrifugation. By ELIFA, NPEVs could be detected and enumerated within 12 h post-infection. Our results demonstrated that Coxsackievirus B1 (CVB1) and CVB5 strains, isolated from diarrheic children, induced severe diarrhea in orally-inoculated 9-12 day-old mouse pups, fulfilling Koch's postulates. The methods described here would facilitate studies on NPEV-associated gastrointestinal disease. (C) 2015 Elsevier B.V. All rights reserved.

Study on the Performance of a Compact Compound Oil/Gas/Water Separator for Offshore Oil Industry

High-efficiency separation of the oil/gas/water mixtures is a significant issue in offshore oil industry. To reduce the total cost by means of reduction in weight and space compared with conventional separators, a novel compact compound oil/gas/water separator is developed. The research works on oil-gas-water separation by compound separating techniques is described in this paper. The innovative separator is a gravity settling tank with helical pipes within and T-shaped pipes outside. Both experiments and numerical simulations are presented to study the separating performance and efficiency of the helical pipes, which are the main part of the separator.

A fully-nonlocal energy-based formulation and high-performance realization of the quasicontinuum method

The quasicontinuum (QC) method was introduced to coarse-grain crystalline atomic ensembles in order to bridge the scales from individual atoms to the micro- and mesoscales. Though many QC formulations have been proposed with varying characteristics and capabilities, a crucial cornerstone of all QC techniques is the concept of summation rules, which attempt to efficiently approximate the total Hamiltonian of a crystalline atomic ensemble by a weighted sum over a small subset of atoms. In this work we propose a novel, fully-nonlocal, energy-based formulation of the QC method with support for legacy and new summation rules through a general energy-sampling scheme. Our formulation does not conceptually differentiate between atomistic and coarse-grained regions and thus allows for seamless bridging without domain-coupling interfaces. Within this structure, we introduce a new class of summation rules which leverage the affine kinematics of this QC formulation to most accurately integrate thermodynamic quantities of interest. By comparing this new class of summation rules to commonly-employed rules through analysis of energy and spurious force errors, we find that the new rules produce no residual or spurious force artifacts in the large-element limit under arbitrary affine deformation, while allowing us to seamlessly bridge to full atomistics. We verify that the new summation rules exhibit significantly smaller force artifacts and energy approximation errors than all comparable previous summation rules through a comprehensive suite of examples with spatially non-uniform QC discretizations in two and three dimensions. Due to the unique structure of these summation rules, we also use the new formulation to study scenarios with large regions of free surface, a class of problems previously out of reach of the QC method. Lastly, we present the key components of a high-performance, distributed-memory realization of the new method, including a novel algorithm for supporting unparalleled levels of deformation. Overall, this new formulation and implementation allows us to efficiently perform simulations containing an unprecedented number of degrees of freedom with low approximation error.

Estudo de eventos amparado em métricas contábeis: detectando performance operacional anormal em firmas brasileiras

O estudo de eventos amparado em métricas contábeis pode ser considerado como aquele que investiga se os retornos anormais no mercado acionário possuem uma contrapartida no lado real, ou seja, se a performance operacional da firma sofreu modificação decorrente de um determinado evento econômico. O presente estudo tem como foco as escolhas que um pesquisador deve fazer na hora da modelagem de um estudo de evento amparado em métricas contábeis, tais como: que medida de performance utilizar, que modelo de expectativa de performance operacional servirá como benchmark, e que teste estatístico poderia detectar com mais eficiência as anormalidades. Um exemplo de estudo que testa empiricamente, nos EUA, o efeito das escolhas acima nas especificações e poder dos testes estatísticos é o de Barber e Lyon (1996). O presente trabalho pretende testar empiricamente os modelos, analisados por esses autores, nas empresas brasileiras. Para tal, foram extraídas da base de dados da Economática todas as empresas listadas na Bolsa de Valores de São Paulo BOVESPA, com dados contábeis disponíveis para os anos de 2004 a 2010, sendo que foram objeto de análise os anos de 2005 a 2010. Obtiveram-se dados para 605 empresas, e uma média de 1606 observações por métrica contábil. Foram testadas 6 medidas contábeis de performance operacional e 13 modelos de expectativa de desempenho. Para atingir o objetivo, a pesquisa foi dividida em três fases. Fase I Elaboração dos Modelos de Expectativa e formação dos Grupos de Controle; Fase II Teste do Poder explicativo dos Modelos de Expectativa; Fase III Testes para Detectar Performance Operacional Anormal. Para o caso brasileiro, pode-se dizer que a melhor medida para detectar performances operacionais anormais é o ROA2 (Ebitda/Ativo Total), já que foi a que apresentou mais modelos que atenderam a todos os testes estabelecidos, em todas as fases da pesquisa. Quanto ao benchmark, o melhor apontado pelos resultados foi o filtro indústria, classificação Economática. O modelo de desempenho defasado da firma, também apresentou resultados satisfatórios. Por fim, o teste estatístico mais apropriado para detectar performances operacionais anormais é o de Wilcoxon.

Cultura de tecidos e análise do potencial antioxidante de Passiflora alata Curtis

Passiflora alata Curtis, comumente conhecida como maracujá-doce, é uma das espécies do gênero Passiflora cultivadas comercialmente, sendo consumida in natura devido ao seu gosto adocicado. Ela também é utilizada em todo o mundo como ornamental e na medicina popular. O objetivo deste trabalho foi o estabelecimento de diferentes estratégias para a cultura in vitro de P. alata e a análise da produção de substâncias antioxidantes nos materiais obtidos in vitro, em comparação com as plantas in vivo. Diferentes tratamentos visando à quebra da dormência das sementes foram avaliados para a germinação in vitro ou in vivo, além da incubação das sementes sob tipos distintos de luz. Para o estabelecimento das culturas primárias, apices caulinares e segmentos nodais das plântulas derivadas da germinação in vitro foram cultivados em meio MSM . A taxa de alongamento dos brotos e o número de nós por brotos das culturas primárias foram aumentados pela adição de água de coco ao meio. Plantas derivadas dessas culturas foram utilizadas como fontes de explantes nodais, internodais e foliares. O potencial morfogênico de sementes sem tegumento foi também avaliado. Calos friáveis foram induzidos a partir de segmentos nodais e foliares na presença de PIC, e aqueles obtidos a partir de folhas em meio suplementado com PIC a 28,9 μM foram selecionados para o estabelecimento de culturas de células em suspensão. Após o desenvolvimento de diferentes estratégias in vitro para P. alata, folhas de plantas in vivo foram utilizadas para a avaliação de parâmetros que afetam a extração de substâncias antioxidante. O potencial antioxidante foi determinado pelo ensaio DPPH e o conteúdo de fenóis totais foi determinado utilizando o método Folin-Ciocalteau. Após o desenvolvimento do protocolo de extração, a atividade antioxidante dos diferentes materiais in vitro foi também avaliada. A eficiência antirradicalar variou entre os sistemas de cultura estudados, sendo diretamente proporcional ao conteúdo de fenóis totais dos extratos. Esses resultados indicam que as estratégias para cultura in vitro de P. alata desenvolvidas neste trabalho representam alternativas para a multiplicação de plantas e produção de substâncias fenólicas com ação antioxidante.

Apurando os sentidos: sonoridades, performance e imagens nos rituais de Umbanda em Corumbá

O principal objetivo deste trabalho é investigar o ponto de vista nativo do conceito de sonoridades que constituem os rituais de Umbanda em Corumbá, município situado no Estado de Mato Grosso do Sul, Centro-Oeste brasileiro, pouco presente na literatura sobre o tema. Para a execução da pesquisa, foi utilizada a concepção de Seeger, na qual é preciso observar todo o contexto em que a manifestação musical ocorre, ou seja, o fato social musical total, com o intuito de compreender mais profundamente seus significados. Como metodologia, a pesquisa lançou mão da observação participante e entrevistas em profundidade com alguns dos importantes personagens inseridos no contexto umbandista local. O campo foi, igualmente, registrado por meio de fotografias, vídeos e gravações em áudio, a fim de viabilizar a criação de um acervo e, ainda, facilitar a transcrição e análise do material coletado e quiçá, viabilizar desdobramentos deste trabalho. Concluiu-se que a sua matéria-prima, as frequências sonoras, representam um instrumento ideal para a Umbanda, pelas seguintes razões: em primeiro lugar, as sonoridades, por sua natureza etérea, podem, assim como os orixás e as entidades espirituais, constituir vibrações invisíveis aos olhos dos leigos, mas não dos fiéis, que penetram os corpos e podem ser percebidos tanto no mundo espiritual quanto no mundo físico; em segundo lugar e, em decorrência do primeiro aspecto, é um perfeito meio para a comunicação tanto partindo do mundo espiritual em direção aos seus adeptos quanto vice-versa. É por meio das curimbas ou pontos que os orixás cantam as suas dijinas, ou seja, os seus nomes, realizando a continuidade de uma tradição ancestral. A pulsação promovida pelas vibrações sonoras traz consigo toda a simbologia cosmológica presente na Umbanda, revestida por um complexo e belo universo de narrativas, vestimentas, cores, cheiros, coreografias, afetos, intenções, realizações e afirmações identitárias dos componentes dos rituais vivenciados. Chegou-se, ainda, à conclusão de que podemos considerar o que os umbandistas da Tenda Nossa Senhora da Guia, principal grupo estudado, entendem por sonoridade, um fato social total, clássico conceito cunhado por Mauss. Estrategicamente e borrando as fronteiras entre resistência e comunhão com a comunidade maior em que está inserida na cidade, a Tenda aprofunda a cada dia as suas raízes, fincadas por Maria Theodora Gonçalves de Paula nos idos de 1920, ainda escrava. Apesar de ter findado oficialmente em 1888, a escravidão permaneceu nos rincões do País que resistia às mudanças sociais, econômicas e políticas que ocorriam em território nacional. A Tenda, hoje, é uma instituição que estabelece importantes trocas simbólicas, econômicas, políticas, sociais, culturais e espirituais, a partir de um território quilombola reconhecido pela Fundação Palmares e na esfera religiosa, pela a Federação dos Cultos Afro-Brasileiros e Ameríndios de Mato Grosso do Sul (FECAMS)