bluuebunny/crossref_metadata_2025 huggingface dataset:
Mamíferos não voadores (Mammalia) da Estação Ecológica Serra Geral do Tocantins
Authors: Carmignotto Ana Paula , Aires Caroline Cotrim
Published: September 2011

A comunidade de mamíferos terrestres foi amostrada em três localidades (1-Mateiros, TO; 2- Rio da Conceição, TO e 3- Formosa do Rio Preto, BA) no interior da Estação Ecológica Serra Geral do Tocantins. Para o registro dos marsupiais e pequenos roedores foram utilizadas armadilhas convencionais (5.396 armadilhas.noite) e armadilhas de queda (5.300 pitfalls.noite) nas diferentes fitofisionomias encontradas, entre elas: campo úmido, campo limpo, campo sujo, campo cerrado, cerrado sensu stricto, cerrado com afloramentos rochosos, mata de galeria e mata de galeria úmida. No caso dos mamíferos de médio e grande porte, foram obtidos registros casuais através de observação direta e evidências indiretas (rastros, fezes, crânios e carcaças de animais encontrados mortos). Foram amostradas 24 espécies de pequenos mamíferos e 17 espécies de mamíferos de médio e grande porte, totalizando 41 espécies para a região. Considerando-se os pequenos mamíferos, a comunidade foi representada por várias espécies raras e de abundância intermediária, e poucas espécies muito abundantes. Os roedores cricetídeos dominaram tanto em número de espécies (14) quanto em abundância (50% da comunidade). As espécies se distribuíram, basicamente, em dois tipos de fisionomias: um grupo esteve restrito aos ambientes florestais, e outro às formações abertas, demonstrando a grande seletividade de hábitats e a importância de se amostrar o mosaico de hábitats presente na região para uma melhor caracterização da diversidade deste grupo de mamíferos. Em termos biogeográficos, a fauna de pequenos mamíferos amostrada apresentou certa sobreposição com a fauna da Caatinga e da Amazônia, evidenciando a importância destes domínios para a composição de espécies das comunidades que habitam a porção norte do Cerrado, além da presença de espécies endêmicas e de distribuição geográfica restrita ao norte do domínio, caracterizando uma comunidade distinta de outras regiões do Cerrado. Em relação aos mamíferos de médio e grande porte, a presença de um elevado número de espécies ameaçadas de extinção (10) também ressalta a importância da preservação desta região.
Borboletas (Lepidoptera: Papilionoidea e Hesperioidea) do Sudoeste do Pampa Brasileiro, Uruguaiana, Rio Grande do Sul, Brasil
Authors: Rosa Pamela Laiz Paré da , Chiva Enrique Querol , Iserhard Cristiano Agra
Published: September 2011

O Pampa é o único bioma Brasileiro que ocorre em apenas um estado. Além de formações campestres, possui uma variedade de ecossistemas associados. Este trabalho tem como objetivo realizar um inventário das borboletas do Parque Natural Municipal de Uruguaiana, contribuindo com o conhecimento deste grupo de insetos desta região. Foram percorridas três transecções em cada ocasião amostral: Mata Ciliar (MC), Margem do Rio Uruguai (MR), e Campo Sujo (CS). Após quatro amostragens ao longo de um ano e um total de 99 horas-rede de esforço amostral foram registradas 46 espécies, ocorrendo dois registros novos para o Rio Grande do Sul e um registro novo para o Brasil.
Ictiofauna associada às raízes de mangue do estuário do Rio Pacoti - CE, Brasil
Authors: Osório Frederico Moreira , Godinho Wander Oliveira , Lotufo Tito Monteiro da Cruz
Published: September 2011

Margens de estuários com a vegetação de manguezal formam um importante hábitat para peixes, pois são zonas de alimentação, abrigo e berçário. O presente trabalho tem como objetivo caracterizar a ictiofauna associada às raízes de mangue do estuário do Rio Pacoti (CE). Foram realizados 10 censos visuais com duração de 90 minutos cada. Foram feitas 671 avistagens, com densidade média de 0,74 avistagens/minuto. Os indivíduos pertencem a 22 espécies e 18 famílias. Todas as espécies registradas são de origem marinha, apesar das amostragens serem realizadas principalmente no período chuvoso. As famílias que apresentaram um maior número de espécies foram Gerreidae e Lutjanidae. As espécies que apresentaram maior frequência de ocorrência foram Lutjanus alexandrei, Lutjanus jocu e Bathygobius soporator, estando presentes em todos os censos. As duas espécies mais abundantes foram L. alexandrei (48%) e L. jocu (17%). Levando-se em consideração as estimativas de tamanho destas espécies, foi verificado que as raízes de mangue são habitadas principalmente por indivíduos jovens de ambas as espécies, o que leva a supor que estas utilizam tal habitat como área de berçário. Contudo, na estação de coleta com menor complexidade estrutural foi avistado o maior número de indivíduos do gênero Lutjanus, em praticamente todas as faixas de comprimento, o que sugere que no Rio Pacoti a quantidade de raízes pode não influenciar na quantidade de indivíduos abrigados. Aproximadamente 70% das espécies avistadas também ocorrem em ambientes recifais, o que demonstra a existência de fortes conexões entre esses dois ecossistemas. Os resultados encontrados enfatizam a importância do habitat estudado para a conservação da ictiofauna costeira e apontam a necessidade de pesquisas relacionadas principalmente ao recrutamento, padrões reprodutivos e tróficos das duas espécies mais representativas.
Analysis of self-fertilization and meiotic behavior of eleven Brazilian triticale cultivars at two sowing dates
Authors: Guerra Divanilde , Pacheco Marcelo Teixeira , Federizzi Luiz Carlos
Published: September 2011

Eleven Brazilian hexaploid triticale cultivars (2n = 6x = 42), from three breeding programs, were evaluated for their ability of self-fertilization in 2006 and for meiotic behavior, meiotic index and pollen viability at two sowing dates in 2007. High potential of self-fertilization was observed, with values up to 89.52 %. Many irregularities were found in the meiotic analysis, such as the presence of univalents, laggard chromosomes and micronuclei in tetrads, which compromised both meiotic behavior and meiotic index. At the first sowing date, more suitable for normal plant development, overall mean values of 52.68 % for normal cells and 64.95 % for meiotic index were observed. At the second sowing date, less appropriate for the crop, overall means of 52.23 % for normal cells and 58.24 % for meiotic index were obtained. Despite all the irregularities, considerable pollen viability was observed, reaching overall means of 92.08 % and 91.07 % for the first and second sowing dates, respectively.
Stratified mass selection of promising Spondias mombin clones in a commercial crop
Authors: Nunes José Airton Rodrigues , Santana Francisco Ferreira , Gomes Regina Lúcia Ferreira , Lopes Ângela Celis de Almeida , Pereira Maria Marlúcia Gomes , Soares Edson Basílio
Published: September 2011

This study aimed to estimate genetic parameters and identify promising clones of Spondias mombin in ungrafted commercial crop by stratified mass selection, based on the average of two harvests, using mixed models. The base population growing on a private farm in Teresina/PI comprised 82 plants, which were evaluated in the growing seasons 2008 and 2009. Total titratable acidity (TTA), total soluble solids (Brix), Brix/TTA, fruit weight (FW), seed weight (SW), pulp yield (PuY), and processing yield (PrY) were measured. Significant genetic variation among plants was detected for all traits. The coefficients of repeatability were 0.97 (TTA), 0.39 (Brix), 0.86 (Brix/TTA), 0.84 (FW), 0.82 (SW), 0.35 (PuY), and 0.39 (PrY). The chemical were generally not correlated with the physical fruit traits. Ranking by predicted phenotypic values associated with PrY and Brix/TTA identified nine promising plants (PrY>6.9% and Brix/TTA>10).
Pozzolanic additions for durability of concrete structures
Authors: Bertolini Luca , Carsana Maddalena , Frassoni Massimiliano , Gelli Massimo
Published: September 2011

Pozzolanic additions, used for partial replacement of Portland cement clinker, can improve the strength and durability of concrete structures. Most of pozzolanas used nowadays are residues of industrial processes and their use in concrete technology has the added advantage of improving the sustainability of the cement and concrete industries. For this reason, there is great interest in studying the behaviour of new materials with potential pozzolanic activity. With this regard, several tests have been proposed in the literature to assess different aspects of the pozzolanic behaviour of mineral additions, but these often do not give the same results when used to compare various additions. This paper presents the results of a study aimed at the evaluation of the beneficial effects of different mineral additions (natural pozzolanas, industrial residues and recycled materials such as ground glass) in relation to concrete performance, using different methods of testing. The role of the different additions is analysed, showing lower performance for natural pozzolanas and good behaviour of the finely ground glass. The possibility of using measurement of electrical resistivity as a non-destructive method capable of evaluating the pozzolanic activity of mineral additions at different curing time is discussed.
Controls on carbon dynamics by ecosystem structure and climate for southeastern U.S. slash pine plantations
Authors: Bracho Rosvel , Starr Gregory , Gholz Henry L. , Martin Timothy A. , Cropper Wendell P. , Loescher Henry W.
Published: September 2011

Planted pine forests (plantations) in the southeastern United States are an important component of the continent's carbon balance. Forest carbon dynamics are affected by a range of factors including climatic variability. Multiyear droughts have affected the region in the past, and an increase in the frequency of drought events has been predicted. How this increased climatic variability will affect the capacity of the region's pine plantations to sequester carbon is not known. We used eddy covariance and biometric approaches to measure carbon dynamics over nine years in two slash pine plantations (Pinus elliottiivarelliottiiEnglm) in north Florida, consisting of a newly planted and a mid‐rotation stand. During this time, the region experienced two multiyear droughts (1999–2002 and 2006–2008), separated by a three‐year wet period. Net ecosystem carbon accumulation measured using both approaches showed the same trends and magnitudes during plantation development. The newly planted site released 15.6 Mg C/ha during the first three years after planting, before becoming a carbon sink in year 4. Increases in carbon uptake during the early stages of stand development were driven by the aggrading leaf area index (LAI). After canopy closure, both sites were continuous carbon sinks with net carbon uptake (NEE) fluctuating between 4 and ∼8 Mg C·ha−1·yr−1, depending on environmental conditions. Drought reduced NEE by ∼25% through its negative effects on both LAI and radiation‐use efficiency, which resulted in a larger impact on gross ecosystem carbon exchange than on ecosystem respiration. While results indicate that responses to drought involved complex interactions among water availability, LAI, and radiation‐use efficiency, these ecosystems remain carbon sinks under current management strategies and climatic variability. Variation within locations is primarily due to major disturbances, such as logging in the current study and, to a much lesser extent, local environmental fluctuations. When data from this study are compared to flux data from a broad range of forests worldwide, these ecosystems fill a data gap in the warm‐temperate zone and support a broad maximum NEE (for closed‐canopy forests) between 8°C and 20°C mean annual temperature.
New Standard for Evaluating Casing Connections for Thermal-Well Applications
Authors: Nowinka Jaroslaw , Dall'Acqua Dan
Published: September 2011

Casing connections in thermal wells experience extreme loads owing to exposure to high temperatures ranging as high as 200 to 350°C, stresses exceeding the elastic limit, and cyclic plastic deformation. To date, no standard procedure has been adopted by the industry to qualify casing connections for such conditions. In particular, the existing evaluation standard published jointly by the International Organization for Standardization (ISO) and American Petroleum Institute (API) ISO 13679/API 5C5 (ISO 2002) does not apply to tubular loads beyond pipe body yield and temperatures above 180°C. Proprietary procedures have been used to qualify connections for individual thermal operations, but none of those has been accepted as an industry standard.

This paper introduces a new protocol for evaluating casing connections for thermal applications: Thermal Well Casing Connection Evaluation Protocol (TWCCEP). While founded on longstanding work in the thermal-well arena, TWCCEP was developed through a multiclient project sponsored by several major operators and connection manufacturers. Following project completion, TWCCEP was released to the public domain and submitted to ISO for adoption as an international standard.

TWCCEP uses both analytical and experimental procedures to assess performance of a candidate connection under conditions typical of service in thermally stimulated wells. The objective of the analytical component is to assess sensitivities of the candidate connection to selected design variables, and identify worst-case combinations of those variables for configuration of specimens for physical testing. The purpose of the physical testing is to verify performance of the connection specimens under assembly-and- loading conditions simulating thermal-well service.

In addition to an overview of TWCCEP, this paper illustrates how engineering analysis, numerical simulation, and reduced-scale physical testing were used to examine the impacts of various design and loading variables on connection strength and sealability, and subsequently to formulate the analysis-and-test matrix prescribed in the TWCCEP evaluation procedure.

Adoption and consistent use of TWCCEP is expected to increase operational reliability and decrease failure potential of casing strings in thermal wells. Learnings from the protocol development process will also help in the formulation of guidelines for connection requalification for thermal applications, in cases when one or more of the design variables change.
Understanding the Roles of Inflow-Control Devices in Optimizing Horizontal-Well Performance
Authors: Li Zhuoyi , Fernandes Preston , Zhu D..
Published: September 2011

An inflow-control device (ICD) is completion hardware that is deployed as part of well completions aimed at distributing the inflow evenly. Even though the detailed structures vary from one design to another, the principle for different ICDs is the same—restrict flow by creating additional pressure drop and therefore adjusting wellbore pressure distribution to achieve an evenly distributed flow profile along a horizontal well. With a more evenly distributed flow profile, one can reduce water or gas coning, prevent sand production, and solve other drawdown-related production problems. In general, ICDs are not adjustable; once installed in the well, the location of the device and the relationship between rate and pressure drop are fixed. This makes the design of a well completion and ICDs extremely critical for production. ICDs can be either beneficial or detrimental to production, depending on the reservoir condition, well structure, and completion design. Realizing that reservoir conditions will change during the life of a well, the impact of an ICD is a function of time. Reservoir heterogeneity and uncertainty can complicate the situation easily. The ICDs sometimes can be overlooked if the design is based only on reservoir flow simulations at initial conditions.

In this paper, we will investigate how and when an ICD should be used. An integrated analysis method of inflow (reservoir) and outflow (wellbore) is used to generate the flow profile of a horizontal well, and additional frictional pressure drop created by ICDs will be considered. Two conditions that result in production problems, wellbore pressure drop and reservoir heterogeneity, will be addressed. The focus will be on when and how an ICD can optimize production. Examples will be used to illustrate that it is critical to understand the reservoir conditions and wellbore dynamics together when designing a well completion with ICDs. The observations from this study show that overdesigned ICDs will not just increase the cost of well completion, but also will impact the well performance negatively. ICDs are not a universal solution of production problems. The application requires a thorough understanding of long-term reservoir behavior and upfront reservoir characterization for implementation.
Estimates of Fracture Lengths in an Injection Well by History Matching Bottomhole Pressures and Injection Profile
Authors: Suri Ajay , Sharma Mukul M. , Peters Ekwere J.
Published: September 2011

An injection-well model is presented and used to history match a field injector's bottomhole pressures (BHPs) and injection profile (injection rate into each layer), taking into account plugging of formation caused by suspended solids in the injection water, poro- and thermoelastic stresses, injector shut-ins/restarts, and changes in both the injection rates and the average reservoir pressure. Fracture lengths and injection profile are estimated for a field injector as a case study. The injection-well fracture model is very similar to the Perkins and Gonzalez (1985) model except that it has integrated a more comprehensive and experimentally tested internal filtration model (Rajagopalan and Tien 1976; Pang and Sharma 1997; Gadde and Sharma 2001; Suri 2000; Wennberg and Sharma 1997) for calculating permeability reduction. It has also added a pressure-transient model that makes the earlier reservoir flow models more accurate.

The solids deposition is modeled using a filtration model (Rajagopalan and Tien 1976). The fluid flow in the reservoir is modeled using three approximated composite zones with uniform saturations and average mobilities, and the pressure for the fractured wellbore is calculated with the help of Gringarten's (1974) infinite-conductivity solution. The induced-fracture lengths are calculated on the basis of the Perkins and Gonzalez fracture-propagation model (1985) that accounts for the thermal and poroelastic stresses. The model is developed into a semianalytical numerical simulator that can predict and history match an injector's daily BHP, fracture lengths, and injection profile. Future estimates of pump pressures, BHP, injectivity, skin, front locations, fracture lengths, and injection profile can be obtained from this model. Both short-term pressure transients and long-term pseudosteady pressures observed over several years of injection can be history matched to capture effects that are important at both short and long time scales.

Finally a field-case injection-well study is presented in which BHP and injectivity are history matched over a period of 3 years. We show that the model can be used to estimate the minimum horizontal stresses in the layers if they are not known. Estimates of fracture lengths, fraction of flow, permeability reduction, and skin and front locations are also obtained. There is significant uncertainty in the results because of uncertainty in the model inputs and in the completeness of the physics of the model of fracturing itself. Both the solids deposition and the opening/closing of the injection-induced fractures had to be accounted for to obtain the history match. The layer/sand stresses and the water quality are the most important parameters that determine the well's injectivity, fracture growth, and injection profile. Microseismic surveys and PLTs are needed to confirm fracture lengths in injection wells.
Best Practices in the Allocation, Commissioning, and Maintenance of Ultrasonic Gas-Leak Detectors
Authors: Naranjo Edward , Neethling Gregory A.
Published: September 2011

Ultrasonic gas-leak detection (UGLD) is gaining broader acceptance in the oil and gas industry as a means for detecting combustible-gas leaks. UGLD responds to high-pressure leaks by measuring the airborne ultrasound emitted, which when detected by the sensor provides a measure that is proportional to the leak rate. Principal advantages of the technology are that it does not require gas to be transported to the detector and it provides coverage for a relatively large area, up to 20 m in radius, suggesting that UGLD is suitable for detecting gas releases in open, well-ventilated sections of offshore platforms.

Despite such advantages, the location criteria and commissioning and routine-maintenance procedures for UGLD are not as well understood as those for conventional gas detectors. A reason might be that UGLD requires the establishment of an ambient ultrasonic background-noise level to decide the alarm level and assist with selection of optimal location, a requirement that has no parallel with point infrared (IR) or catalytic sensors. Location of ultrasonic gas-leak detectors is also based on identifying the potential sources of leaks and taking into account acoustic reflections and interferences caused by continuous or short-time-scale background ultrasonic noise.

Such newness might be enough to give some would-be users pause. They may believe that UGLD is for people with high technical competence or that mapping, commissioning, and maintenance are best left to UGLD-equipment manufacturers. Experience by one of the authors of this monograph suggests the contrary. UGLD, for its reliance on ultrasound as a proxy for a gas leak, is a simple concept to understand. Over the course of more than 3,000 installations during the last 10 years, offshore-platform personnel have developed best practices that reduce the time and cost required for installing and commissioning ultrasonic gas monitors and that ease the burden on maintenance. In this report, we examine several of these procedures and highlight the simplicity of installation and maintenance of this method of gas detection.
LNG for Petroleum Engineers
Authors: Choi Michael S.
Published: September 2011

While remote parts of the world are awash with hundreds of trillions of cubic feet (Tcf) of natural gas, the industrialized West and emerging economies of the East cannot get enough of the clean-burning, environmentally friendly fuel. The problem is transporting this compressible fluid long distances and across major bodies of water. For markets more than 1,500 miles distant, liquefied natural gas (LNG) has proved to be the most economic option. By refrigerating natural gas (primarily methane) to–260°F (–162°C), thereby shrinking its volume by 600:1, natural gas in the form of LNG can be transported in large insulated cryogenic tankers at a reasonable cost.

Natural-gas liquefaction is a series of refrigeration systems similar to home air-conditioning (AC) systems, consisting of a compressor, condenser, and evaporator to chill and condense the gas. The difference is in the scale and magnitude of the refrigeration. A typical single-train LNG plant may cost USD 1.5 billion and consume 6 to 8% of the inlet gas as fuel. Because many of the impurities (e.g., water vapor, carbon dioxide, hydrogen sulfide) and heavier hydrocarbon compounds in natural gas would freeze at LNG temperatures, they must first be removed and disposed of or marketed as separate products.

This paper will provide an overview of LNG liquefaction facilities, from inlet gas receiving to LNG storage and loading. However, the focus is on the liquefaction process and equipment. Differences among the commercially available liquefaction processes (e.g., cascade, single mixed refrigerant, propane precooled mixed refrigerant, double-mixed refrigerant, nitrogen) will be discussed. The aim is to provide SPE members with a clear understanding of the technologies, equipment, and process choices required for a successful LNG project.
Leveraging a Common Infrastructure To Support Qatar's Rapid LNG Expansion
Authors: Al-Amoodi Ahmed , Felton Keith C. , Kasim Kamal , Whitehead Mike , Kouki Khaled
Published: September 2011

The State of Qatar is rapidly expanding to capture almost one-third of the world's liquefied-natural-gas (LNG) market. By 2010, LNG exports from the State of Qatar are projected to reach 77 million tonnes per annum (Mt/a) (This was the outlook in late 2009). In addition to the LNG production, there will be a sizeable quantity of byproducts (condensate, propane, butane, and sulfur) as a result of the LNG production. These byproducts are expected to reach production rates of approximately 80 000 m3/d [500,000 barrels per day (B/D)] of condensate, 20 000 tonnes per day (t/d) of propane, 13 000 t/d of butane, and 12 000 t/d of sulfur.

To support this expansion, the State of Qatar has embarked on a pioneering approach to the storage and loading of LNG and its byproducts that will serve as an example of significant capital-investment savings, operational flexibility, and reduced land requirements. Traditionally, dedicated storage and loading facilities (infrastructure) have been designed and built to support a specific LNG production train and its associated byproducts. The State of Qatar's innovative approach has been the design and construction of a fully integrated common infrastructure to support all of the joint-venture-owned LNG production trains and other gas-related projects in Ras Laffan Industrial City (RLC). This paper will describe the unique aspects of this fully integrated infrastructure, its benefits, and the complexities and challenges associated with making the vision of a fully integrated LNG infrastructure come to fruition.
Commissioning and Operational History of Nkossa II LPG FSO
Authors: McLean David , Stott Conor , Foster Stephen , Hesse Emmanuelle
Published: September 2011

In the mid-1990s, our client realized that their recent offshore find would yield viable liquefied-petroleum-gas (LPG) content. With the proposed field located more than 20 nautical miles offshore from an underdeveloped area, the option of exploitation on site was identified. Oil floating storage/offloading (FSO) units, usually adaptations of existing oil tankers, were already an established alternative to piping product ashore at that time. Therefore, tenders were invited for the provision of an LPG FSO unit. Any party tendering for this task would be covering new ground because this installation would be among the first of its kind. In particular, the physical properties of LPG demand different handling systems and techniques compared to oil.

In tendering, we drew from the diverse marine enterprises within our group. We also engaged a partner specialized in offshore solutions. We had access to existing LPG tonnage of suitable capacity and our own yard for conversion work. We also had a competent technical support structure and potential within our personnel base for operational requirements. As with any new project, once tender requirements were met and accepted, evolution occurred. This evolution is of course not limited to the period leading up to commissioning but has continued through to the present.

It is often the case that delivery of a specialized service holds a narrow spectrum of interest. However, it is our hope that this project, although relatively specialized, may also have value for any concern engaged in offshore storage and offloading. By this time, we have operated the unit for almost 15 years and can share some valuable experience.
Kinetic Modeling of Fischer-Tropsch Synthesis over Fe/Ce/Al2O3
Authors: Atashi Hossein , Fazlollahi Farhad , Sarkari Majid , Mirzaei Ali A. , Allahyari Shahrasb Mohsen
Published: September 2011

In this experimental study, a kinetic model has been developed for Fischer-Tropsch synthesis reactions by using Fe/Ce/Al2O3 as the catalyst (80% Fe/20% Ce/5wt%Al2O3) in a fixed-bed micro reactor assuming no internal or external diffusion. Operating conditions of the reactor are as follows: reactor total pressure 6-22 atm; Temperature 543-573 K; H2/CO feed ratio 1.5-2 and space velocity 4200 hr-1. Light alkenes were successfully produced due to high activity and selectivity of the catalyst. Considering the mechanism of the process and Langmuir-Hinshelwood- Hogan-Watson (LHHW) approach, four different mechanisms, namely carbide, enol, combined carbide-enol, and parallel carbide-enol were defined for CO consumption rate equations. The rate expressions for the CO hydrogenation reactions are based on elementary reaction corresponding to the carbid-enol mechanism. The obtained rate expressions for the CO hydrogenation reactions from nonlinear regression analysis and Levenberg-Marquardt method demonstrate that the formation of monomer species (HCOs) due to CO hydrogenation reaction has controlled the FTS reaction rate. The activation energy and adsorption enthalpy were calculated as 58.38 kJ/mol and -22.26 kJ/mol, respectively. Also, the effects of temperature and pressure variation on selectivity and production rate of light products are presented.
Modeling, Simulation and Optimization of a Three-Phase Catalytic Slurry Intensified Continuous Reactor
Authors: Shi Li
Published: September 2011

A dynamic model of three-phase catalytic slurry intensified continuous reactor is proposed, performing the o-cresol hydrogenation. Dynamic simulations are performed to describe the reactor behaviors from start-up to steady-state operating point, and also dynamic behaviors in response of steps disturbances of three effective input variables. An off-line optimization is solved through non-linear programming used of Sequential Quadratic Programming (SQP), a new operating point is obtained with higher productivity and conversion.
Critical Analysis of Kinetic Modeling Procedures
Authors: Pinto José Carlos , Lobao Marcos W. , Alberton Andre L. , Schwaab Marcio , Embiruçu Marcelo , Vieira de Melo Silvio
Published: September 2011

In this work, issues related to the mathematical modeling and statistical analyses of kinetic data are discussed. Firstly, problems related to the combinatorial explosion of the number of plausible kinetic models are analyzed, when complex reaction mechanisms are taken into consideration and distinct rate determining steps are assumed. Although modeling procedures based on rate-determining steps can lead to oversimplification of kinetic models, these procedures are still very popular because the existence of multiple rate-determining steps usually renders the analytical derivation of kinetic rate expressions impossible. However, if the derived kinetic models are too simple, one can face serious difficulties to fit the proposed models to available experimental data. Secondly, problems related to the statistical analyses of experimental data are discussed. Particularly, very often statistical tools are used even when some of the fundamental assumptions required for their validity are violated. For this reason, the fundamental grounds that support some of the most popular statistical tools are discussed in the framework of the kinetic analysis.
Cervical arthroplasty in two dogs with disk-associated cervical spondylomyelopathy
Authors: Adamo Pietro Filippo
Published: September 2011

Case Description—A 4-year-old sexually intact male Doberman Pinscher (dog 1) was evaluated for signs of recurrent cervical pain and ataxia, and a 12-year-old neutered male mixed-breed dog (dog 2) was evaluated for a 4-month history of ataxia and tetraparesis.

Clinical Findings—Examination via magnetic resonance imaging (MRI) revealed spinal cord compression due to disk-associated cervical spondylomyelopathy at C6–7 in dog 1 and at C5–6 in dog 2.

Treatment and Outcome—Both dogs were surgically treated with a ventral slot procedure and spinal cord decompression, followed by insertion of a titanium cervical disk prosthesis at the affected site. Evaluation of radiographs obtained immediately after surgery indicated that each prosthesis was appropriately placed and provided adequate distraction. Radiographic and neurologic evaluations were performed 2 weeks and 3, 6, and 12 months after surgery in both dogs and 18 months after surgery in dog 1. Distraction of the vertebral bodies decreased moderately over time in both dogs. Intervertebral mobility determined via radiographic assessment of the prosthetic disk during neutral positioning, flexion, and traction of the cervical vertebral column was lost over time in dog 1 and was not achieved in dog 2. Eighteen months after surgery, results of MRI in dog 1 indicated adequate spinal cord decompression with no degeneration in other cervical disks.

Clinical Relevance—Cervical arthroplasty was well tolerated with no complications, and outcome was excellent in both dogs; prosthesis presence did not affect ability to reassess the area via MRI. Studies of cervical arthroplasty in dogs with disk-associated cervical spondylomyelopathy are warranted.
Dysuria caused by a partially obstructing urethral membrane in a female dog
Authors: Lechner Elizabeth S. , Cooke Kirsten L.
Published: September 2011

Case Description—A 3.5-year-old spayed female Labrador Retriever was examined for dysuria of unknown duration.

Clinical Findings—Urogenital examination revealed a recessed vulva and a persistent hymen. The hymen was broken down digitally. Results of urinalysis at the referral examination were unremarkable, and no clinically relevant abnormalities were detected on clinicopathologic analysis of blood and serum samples or cytologic evaluation of a vaginal smear. After clinical signs persisted, retrograde contrast vaginourethrocystography was performed; results were considered normal. During uroendoscopic examination, a translucent membranous structure was detected that partially obstructed the urethral lumen near the junction of the urethra and bladder.

Treatment and Outcome—Passage of the endoscope into the urinary bladder ruptured the membranous structure. The dog recovered from the procedure uneventfully and was treated with colchicine (0.03 mg/kg [0.014 mg/lb], PO, q 24 h for 14 days). One month later, the owner reported resolution of clinical signs. Fourteen months later, the patient was evaluated for recurrence of dysuria of several months' duration. Uroendoscopic examination revealed a membranous structure similar to that originally detected; this tissue was also ruptured during endoscopy. The patient was discharged and the owner was instructed to administer colchicine at the same dosage. Recurrence of dysuria was reported again 10 months following the second procedure.

Clinical Relevance—To the authors' knowledge, this type of membranous urethral obstruction has not been previously described in a dog. Administration of colchicine did not prevent recurrence, but potential effects of drug administration on time to recurrence could not be evaluated.
A case of almagel-induced methemoglobinemia after pancreatoduodenal resection
Authors: Gudaityte Jurate , Borodiciene Jurgita , Zalys Ricardas , Rugyte Danguole , Macas Andrius , Latkauskas Tadas
Published: September 2011

We are reporting the case of severe methemoglobinemia resulting from Almagel which was given for treatment of gastrointestinal ulcers after pancreatoduodenal resection. A 64 year old man was treated with Almagel A postoperatively. One day after treatment began, the patient reported what appeared to be cyanotic discolorations of his lips and fingers. (SpO2 80%, normal pO2). Two days later, the patient was diagnosed with methemoglobinemia via co-oximetry and treated with methylene blue. The causes of methemoglobinemia remained unclear, and Almagel A was reinitiated until the second episode of methemoglobinemia, was diagnosed and treated promptly. The dose of benzocaine in Almagel A (100 mg/5 ml) was sufficient enough to cause methemoglobinemia, confirmed using multiwavelength co-oximeter and successfully treated with methylene blue.
Functional characterization of human Kindlin-2 core promoter identifies a key role of SP1 in Kindlin-2 transcriptional regulation
Authors: Khan Ammad , Shimokawa Takashi , Strömblad Staffan , Zhang Hongquan
Published: September 2011

Kindlin-2 is a recently identified FERM and PH domain containing integrin interacting protein. Kindlin-2 is ubiquitously expressed in normal tissues. So far, much effort has been spent exploring the functional aspects of Kindlin-2. However, the transcriptional regulation of Kindlin-2 has not yet been investigated. In this study we identified and functionally characterized the promoter of the human Kindlin-2 gene. We show that the core promoter of Kindlin-2 is a 39 base pair long GC rich fragment located −122/-83 upstream of the Kindlin-2 transcription start site. Functional characterization of this core promoter region by both in silico as well as in vitro/in vivo analysis shows that the transcription factor SP1 plays an important role in regulation of Kindlin-2 expression.
Operating Speed Model for Low-Speed Rural Two-Lane Highways
Authors: Banihashemi Mohamadreza , Dimaiuta Michael , Wang Hui
Published: September 2011

Operating speed, with its deviations along tangent and curve segments of highways, is one of the most common measures to evaluate the consistency of rural two-lane highways. Several models, including the Design Consistency Module (DCM) of FHWA's Interactive Highway Safety Design Model, estimate operating speeds on higher-speed rural two-lane highways. The DCM includes operating speed models for evaluating design consistency on rural two-lane highways. Through 2009 the DCM was limited to higher-speed highways (posted speeds of 45 mph and higher). The goal of the research presented in this paper was to extend the capabilities of the DCM by developing an operating speed model for lower-speed rural two-lane highways (i.e., those with posted speeds of 25 to 40 mph) using data collected by FHWA for that purpose. To determine the operating speed profile along a highway, models to estimate the 85th percentile speeds on tangents and curves were developed, and existing DCM models for acceleration and deceleration rates for transitions between preferred speeds on horizontal design elements were expanded to apply to lower-speed highways. This paper documents the model development process and provides a case study to illustrate application of the model.
Analysis of Platoon Impacts on Left-Turn Delay at Unsignalized Intersections
Authors: Wan Feng , Zhang Yunlong , Fitzpatrick Kay
Published: September 2011

This research aimed to develop a methodology for analyzing the platoon impacts on major-street left-turn (MSLT) delay at two-way stop-controlled intersections. The main idea was to use a microscopic simulation tool to simulate different platoon scenarios in opposing through traffic and then to apply regression models to capture the impacts of platoons on the delay of MSLT. Two platoon variables were adopted as a simplification of the complex platoon scenarios to make analysis of the platoon effects on MSLT delay practical. The first two steps were to build simulation models for real-world unsignalized intersections and simulate scenarios with a combination of various factors related to platoons in VISSIM simulation. The models were calibrated with field data before simulation started. The next step was to define, derive, and calibrate two platoon variables for describing the duration and intensity of platoon arrivals in the opposing through traffic. This process effectively simplified the large combination of various factors. Finally, the two platoon variables and their relationship with the change factor of MSLT delay were modeled with regression tools. A relationship between the two variables and the delay change factor was established. The relationship indicated a positive effect by upstream platoons on MSLT delay and made it possible to quantify the impacts. The findings in this research could be used for research on platoon or signal impacts on left-turn treatments.
Should the Diverging Diamond Interchange Always be Considered a Diamond Interchange Form?
Authors: Chlewicki Gilbert
Published: September 2011

The diverging diamond interchange (DDI) has proved to be an ideal interchange solution because of its safety features, low costs, and operational benefits in different scenarios of turning movement volume. Pre vious studies have compared the DDI with other interchange forms by using the same number of through lanes for each interchange design. Those studies used microsimulation software for the analysis and had a limited number of turning movement combinations to sample. This study considered a large sample of turning movement combinations and compared more interchange configurations to determine whether the DDI might have more applications than previous studies have indicated. A basic form of the critical lane volume method was used to evaluate the different interchange configurations. Although this method is not the most perfect method, there is reason to believe that the results are accurate enough to indicate that the DDI may be a viable option in many more scenarios than previously thought. This study concludes that it is worthwhile for practitioners to consider the DDI for any interchange improvement when comparing it with other diamond interchange forms.
Evaluating the Michigan Access Management Program
Authors: Eisele William L. , Frawley William E. , Doyle Tom
Published: September 2011

As state departments of transportation (DOTs) and local transportation agencies make difficult funding decisions in these financially constrained times, access management improvements provide a cost-effective alternative for improving the safety and operation of roadways. Mindful of the benefits of implementing access management treatments, the Michigan DOT has conducted an access management program since 2002. The Michigan DOT contracted with the Texas Transportation Institute (TTI) to provide recommendations for adjustments to the Michigan access management program. As a result of the evaluation, TTI identified lessons learned related to the importance of (a) continuing support and funding for the access management program, (b) a clear access management policy statement, (c) coordination and cooperation between state and local transportation agencies, (d) continued training, (e) interagency coordination across state DOT divisions, (f) continued review and update of technical documentation and guidance, and (g) continued objective program evaluations. The lessons learned that are documented and described in this paper are invaluable reminders to practitioners in state DOTs with established programs and excellent points to consider for practitioners in state DOTs just beginning to foster access management implementation. Practitioners from local transportation agencies (e.g., cities, villages, counties, and townships) that are implementing access management or planning to implement access management will also find these lessons learned invaluable. The research community will also benefit from the lessons learned identified in this paper because the findings validate the procedural, political, and institutional considerations often touted as imperative to successful implementation of access management.
Strictly Dominated Strategies in the Replicator-Mutator Dynamics
Authors: Izquierdo Segismundo S. , Izquierdo Luis R.
Published: September 2011

The replicator-mutator dynamics is a set of differential equations frequently used in biological and socioeconomic contexts to model evolutionary processes subject to mutation, error or experimentation. The replicator-mutator dynamics generalizes the widely used replicator dynamics, which appears in this framework as the extreme case where replication is perfectly precise. This paper studies the influence of strictly dominated strategies on the location of the rest points of the replicator-mutator dynamics, at the limit where the mutation terms become arbitrarily small. It can be proved that such limit rest points for small mutation are Nash equilibria, so strictly dominated strategies do not occur at limit stationary points. However, we show through a simple case how strictly dominated strategies can have an influence on the location of the limit rest points for small mutation. Consequently, the characterization of the limit rest points of the replicator-mutator dynamics cannot in general proceed safely by readily eliminating strictly dominated strategies.
Bioactive Compounds and Biological Activities of Jatropha curcas L. Kernel Meal Extract
Authors: Oskoueian Ehsan , Abdullah Norhani , Ahmad Syahida , Saad Wan Zuhainis , Omar Abdul Rahman , Ho Yin Wan
Published: September 2011

Defatted Jatropha curcas L. (J. curcas) seed kernels contained a high percentage of crude protein (61.8%) and relatively little acid detergent fiber (4.8%) and neutral detergent fiber (9.7%). Spectrophotometric analysis of the methanolic extract showed the presence of phenolics, flavonoids and saponins with values of 3.9, 0.4 and 19.0 mg/g DM, respectively. High performance liquid chromatography (HPLC) analyses showed the presence of gallic acid and pyrogallol (phenolics), rutin and myricetin (flavonoids) and daidzein (isoflavonoid). The amount of phorbol esters in the methanolic extract estimated by HPLC was 3.0 ± 0.1 mg/g DM. Other metabolites detected by GC-MS include: 2-(hydroxymethyl)-2 nitro-1,3-propanediol, β-sitosterol, 2-furancarboxaldehyde, 5-(hydroxymethy) and acetic acid in the methanolic extract; 2-furancarboxaldehyde, 5-(hydroxymethy), acetic acid and furfural (2-furancarboxaldehyde) in the hot water extract. Methanolic and hot water extracts of kernel meal showed antimicrobial activity against both Gram positive and Gram negative pathogenic bacteria (inhibition range: 0–1.63 cm) at the concentrations of 1 and 1.5 mg/disc. Methanolic extract exhibited antioxidant activities that are higher than hot water extract and comparable to β-carotene. The extracts tended to scavenge the free radicals in the reduction of ferric ion (Fe3+) to ferrous ion (Fe2+). Cytotoxicity assay results indicated the potential of methanolic extract as a source of anticancer therapeutic agents toward breast cancer cells.
Pearson-Fisher Chi-Square Statistic Revisited
Authors: Bolboacă Sorana D. , Jäntschi Lorentz , Sestraş Adriana F. , Sestraş Radu E. , Pamfil Doru C.
Published: September 2011

The Chi-Square test (χ2 test) is a family of tests based on a series of assumptions and is frequently used in the statistical analysis of experimental data. The aim of our paper was to present solutions to common problems when applying the Chi-square tests for testing goodness-of-fit, homogeneity and independence. The main characteristics of these three tests are presented along with various problems related to their application. The main problems identified in the application of the goodness-of-fit test were as follows: defining the frequency classes, calculating the X2 statistic, and applying the χ2 test. Several solutions were identified, presented and analyzed. Three different equations were identified as being able to determine the contribution of each factor on three hypothesizes (minimization of variance, minimization of square coefficient of variation and minimization of X2 statistic) in the application of the Chi-square test of homogeneity. The best solution was directly related to the distribution of the experimental error. The Fisher exact test proved to be the “golden test” in analyzing the independence while the Yates and Mantel-Haenszel corrections could be applied as alternative tests.