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A Modern Approach to the Solution and Analysis of the Simha-Somcynsky Model for the Description of Pressure-Volume-Temperature Properties of Polymer Fluids

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Chinese Journal of Polymer Science 2015年第4期33卷 523-523,524-539页

作者： gustavo A.Carri Department of Polymer Science College of Polymer Science and Polymer EngineeringThe University of Akron

We revisit the Simha-Somcynsky model of polymer fluids with the purpose of developing novel theoretical and computational approaches to simplify and speed up its solution as well as the fitting of experimental data, and decrease its level of mathematical complexity. We report a novel method that allows us to solve one of the two equations of the model exactly, thus putting the level of mathematical difficulty on a par with the one of other models for polymer fluids. Moreover, we describe a computational algorithm capable of fitting all five parameters of the model in an unbiased way. The results obtained reproduce literature results and fit experimental pressure-volume-temperature and solubility parameter data for three polymers very accurately. Moreover, the new techniques allow for the investigation of the model at very low temperatures. Unexpectedly, the model predicts behaviors that could be interpreted as a glass transition, as routinely observed in dilatometry and differential scanning calorimetry, and a glass phase. We compared the predicted and experimental Tg＇s for cis poly（1,4-butadiene） and found an excellent quantitative agreement.

关键词： Simha-Somcynsky model PVT properties Polymer fluids.

Serum testosterone levels and excessive erythrocytosis during the process of adaptation to high altitudes

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Asian Journal of Andrology 2013年第3期15卷 368-374页

作者： gustavo F Gonzales high Altitude Research Institute and Department of Biological and Physiological Sciences Faculty of Sciences and Philosophy Universidad Peruana Cayetano Heredia Lima 31 Peru

Populations living at high altitudes （hAs）, particularly in the Peruvian Andes, are characterized by a mixture of subjects with erythrocytosis （16 g dl-1〈haemoglobin （hb）≤21 gdl-1） and others with excessive erythrocytosis （EE）（hb〉21 g dl-1）. Elevated haemoglobin values （EE） are associated with chronic mountain sickness, a condition reflecting the lack of adaptation to hA. According to current data, native men from regions of hA are not adequately adapted to live at such altitudes if they have elevated serum testosterone levels. This seems to be due to an increased conversion of dehydroepiandrosterone sulphate （Dh EAS） to testosterone. Men with erythrocytosis at hAs show higher serum androstenedione levels and a lower testosterone/androstenedione ratio than men with EE, suggesting reduced 17beta-hydroxysteroid dehydrogenase （17beta-hSD） activity. Lower 17beta-hSD activity via A4-steroid production in men with erythrocytosis at hA may protect against elevated serum testosterone levels, thus preventing EE. The higher conversion of DhEAS to testosterone in subjects with EE indicates increased 17beta-hSD activity via the A5-pathway. Currently, there are various situations in which people live （human biodiversity） with low or high haemoglobin levels at hA. Antiquity could be an important adaptation component for life at hA, and testosterone seems to participate in this process.

关键词： chronic mountain sickness DhEA haemoglobin high altitudes men oestradiol women

Modularity and specialization in bat-fly interaction networks are remarkably consistent across patches within urbanized landscapes and spatial scales

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Current Zoology 2021年第4期67卷 403-410页

作者： gustavo Lima Urbieta gustavo Graciolli Jeferson Vizentin-Bugoimi Programa de Pós-Graduação em Ciencias Biológicas Departamento de Sistematica e EcologiaUniversidade Federal da ParaibaCidade Jardim Universitários/nCastelo BrancoJoão Pessoa 58051-900Brazil Programa de Pós-Graduação em Biologia Anim.l Laboratorio de SistematicaEcologia e Evoluqao(LSEE)Instituto de BiocienciasUniversidade Federal de Mato Grosso do Sul(UFMS)Campo Grande 79090-900Brazil Department of Natural Resources and Environmental Sciences University of Illinois at Urbana-ChampaignUrbanaIL 61801USA

Patterns of specialization and the structure of interactions between bats and ectoparasitic flies have been studied mostly on non-urban environments and at local ***,how anthropogenic disturbances influence species interactions and network structure in this system remain poorly ***,we investigated patterns of interaction between Phyllostomidae bats and ectoparasitic Streblidae flies,and variations in network specialization and structure across Cerrado patches within urbanized landscapes in Brazil and between local and regional *** found high similarity in the richness and composition of bat and fly species across communities,associated with low turnover of interactions between *** high specialization of bat-streblid interactions resulted in little connected and modular networks,with the emergence of modules containing subsets of species that interact exclusively or primarily with each *** similarities in species and interaction composition and network structure across communities and scales suggest that bat-fly interactions within Cerrado patches are little affected by the degree of human modification in the surrounding *** remarkable consistency is likely promoted by specific behaviors,the tolerance of Phyllostomidae bats to surrounding urbanized landscapes as well as by the specificity of the streblid-bat interactions shaped over evolutionary time.

关键词： Chiroptera ectoparasites host-parasite network neotropics Streblidae urbanization

Function of seminal vesicles and their role on male fertility

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Asian Journal of Andrology 2001年第4期3卷 251-258页

作者： gustavo F.Gonzales Department of Physiological Sciences Faculty of Sciences and Philosophy and Instituto de Invertigaciones de la Altura Universidad Peruana Cayetano Heredia Lima Peru

The present review has been designed to update the recent developments on the function of seminal vesicles andtheir role on male fertility. It is indicated that the true corrected fructose level is a simple method for the assessment ofthe seminal vesicular function. Measurement of seminal fructose used universally as a marker of the seminal vesiclefunction is not an appropriate approach due to its inverse relationship with the sperm count. The true corrected fructosedefined as [log. motile sperm concentration] multiplied by [seminal fructose concentration] has been shown to be abetter marker of the seminal vesicle function. Seminal vesicular secretion is important for semen coagulation, sperm motility, and stability of sperm chromatinand suppression of the immune activity in the female reproductive tract. In conclusion, the function of seminal vesicle is important for fertility. Parameters as sperm motility, sperm chro-matin stability, and immuno-protection may be changed in case of its hypofunction. (Asian J Androl 2001 Dec; 3:251 -258)

关键词： seminal vesicles male fertility male infertility true corrected fructose

Artificial neural network with a cross-validation approach to blast-induced ground vibration propagation modeling

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Underground Space 2021年第3期6卷 281-289页

作者： gustavo Paneiro Manuel Rafael DECivil/CERENA Tecnico LisboaULisboaPortugal Orica Mining Services Portugal Portugal

Given their technical and economic advantages,the application of explosive substances to rock mass excavation is widely ***,because of serious environmental restraints,there has been an increasing need to use complex tools to control environmental effects due to blast-induced ground *** the present study,an artificial neural network(ANN)with k-fold cross-validation was applied to a dataset containing 1114 observations that was obtained from published results;furthermore,quantitative and qualitative parameters were considered for ground vibration amplitude *** best ANN model obtained has a maximum coefficient of determination of 0.840 and a mean absolute error of 5.59 and it comprises 17 input parameters,12 neurons in a one-layer hidden layer,and a sigmoid transfer *** with the traditional models,the model obtained using the proposed methodology demonstrated better generalization ***,the proposed methodology offers an ANN model with higher prediction ability.

关键词： Rock blasting Excavation Ground vibrations Artificial neural network K-fold cross-validation Modeling

Physicochemical properties of Li_(3)Ba_(2)La_(3)(MoO_(4))_(8):Eu,Tb red-emitting phosphor for solid state white lamps

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Journal of Rare Earths 2023年第9期41卷 1279-1287,I0001页

作者： Kora Lu Rojas Baldivia gustavo A.hirata Center for Scientific Research and higher Education of Ensenada Ensenada Baja California 22860Mexico Center for Nanoscience and Nanotechnology National Autonomous University of Mexico EnsenadaBaja Califomia 22860Mex

In this work,combustion synthesis was used for the first time to fabricate a phosphor material with red emission for applications in solid-state white-light *** synthesized a material with emission wavelength at λ_(em)=617 nm,excited under long UV-blue wavelength based on Eu^(3+),Tb^(3+)-activated molybdates Li_(3)Ba_(2)(La_(1-x-y)Eu_(x)Tb_(y))_(3)(MoO_(4))_(8) with 0 ≤ x ≤1 and 0 ≤ y ≤ 1.A series of powder samples were produced by the combustion method and post-annealed at 800℃ in *** crystalline phase formation was investigated by X-ray diffraction,which reveals the monoclinic C2/c(15) space *** is observed that crystalline structure and morphology are preserved when the host lattice is doped with Eu^(3+) or Tb^(3+) single ions and co-doped with both ions at different doping concentrations.A detailed characterization by scanning electron microscopy(SEM) and transmission electron microscopy(TEM)shows a similar morphology in all samples:rather large(1-7 μm) agglomerate particles with irregular shapes and surrounded by smaller nanoparticles of 50 nm in ***-visible absorption spectra confirm the presence of Eu^(3+) and Tb^(3+) *** luminescent properties of the obtained phosphors were studied in *** measurements indicate that the best emission intensity is for Eu^(3+):Tb^(3+)doping ratios of 80:0,90:0 and 20:*** the other hand,samples with 80:0,60:40,and 20:80 doping ratios show the highest intensity in a detailed photoluminescence analysis and they exhibit the highest quantum yield values.A complete and efficient energy transfer from the sensitizer Tb^(3+) to the activator Eu^(3+) is observed in all co-doped phosphors post-annealed at 800℃ for 4 ***,the Li_(3)Ba_(2)La_(3)(MaO_(4))_(8):Eu^(3+),Tb^(3+) materials fabricated by combustion synthesis are excellent phosphors for being applied as red-emitting component in solid-state white-light lamps due to an improved color rendering index(CRI) that can be obtained under lo

关键词： Molybdate Europium Terbium Luminescence Phosphor-converted LED Rare earths

On the uncertainty of interwell connectivity estimations from the capacitance-resistance model

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Petroleum Science 2014年第2期11卷 265-271页

作者： gustavo A Moreno Larry W Lake YPF Macacha Güemes 515 YPF-Tecnología Baradero S/N (1925) Center for Petroleum and Geosystems Engineering University of Texas at Austin

The capacitance-resistance model （CRM） is an alternative to conventional reservoir simulation. CRM, a simplification of complex numerical models, uses production and injection rates to infer a reservoir description. There is no prior geologic model. The principal output of CRM fitting is the fraction of injected fluid （usually water） that is produced at a producer at steady-state. These fractions are interwell connectivities. Interwell connectivities are fundamental information needed to manage waterfloods in oil reservoirs. The data-driven CRM is a fast tool to estimate these parameters in mature fields and allows one to make full use of the dynamic data available. This paper considers the problem of setting an upper bound on the uncertainty of interwell connectivities for linear-constrained models. Using analytical bounds and numerical simulations, we derive a consistent upper limit on the uncertainty of interwell connections that can be used to quantify the information content of a given dataset.

关键词： Data-driven models capacitance-resistance model secondary recovery waterfloodoptimization interwell connectivities

Analyses of Sexual Reproductive Success in Transgenic and/or Mutant Plants

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Journal of Integrative Plant Biology 2009年第8期51卷 719-726页

作者： Cristiane P. G. Calixto gustavo h. Goldman Maria helena S. Goldman Departamento de Biologia Faculdade de Filosofia Ciências e Letras de Ribeirao PretoUniversidade de So Paulo 14040-901 Brazil PPG Departamento de Gentica Faculdade de Medicina de Ribeiro PretoUniversidade de So Paulo 14049-900 Brazil Departamento de C. Farmacêuticas Faculdade de Ciências Farmacêuticas de Ribeiro PretoUniversidade de So Paulo 14040-903 Brazil Departamento de Biologia Faculdade de Filosofia Ciências e Letras de Ribeirao Preto Universidade de So Paulo 14040-901 Brazil

The pistil, the female reproductive organ of plants, is a key player in the success of sexual plant reproduction. Ultimately, the production of fruits and seeds depends on the proper pistil development and function. Therefore, the identification and characterization of pistil expressed genes is essential for a better understanding and manipulation of the plant reproduction process. For studying the function of pistil expressed genes, transgenic and/or mutant plants for the genes of interest are used. The present article provides a review of methods already exploited to analyze sexual reproductive success. We intend to supply useful information and to guide future experiments in the study of genes affecting pistil development and function.

关键词： knockout mutant plants overexpression transgenic plants pistil expressed genes plant sexual reproduction reproductive success silenced transgenic plants.

The expansion of Brazilian agriculture:Soil erosion scenarios

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International Soil and Water Conservation Research 2013年第3期1卷 37-48页

作者： gustavo h.Merten Jean P.G.Minella V isiting Research Professor Dept.of Civil EngineeringL Diversity of MinnesotaMNLSA Department of Soils Federal Lniversity of Santa MariaZip Code 97105900Santa MariaRSBrazil

During the next 10 years Brazil's agricultural area will expand to meet increased domestic and worldwide demand for food,fuel,and *** choices regarding land use will determine to what degree this expansion will have adverse effects that include soil erosion,reservoir siltation,water quality problems,loss of biodiversity and social conflict,especially around indigenous *** paper presents an up-to-date inventory of soil erosion in Brazil caused by crop and livestock activities and provides estimates based on three different hypothetical land-use scenarios to accommodate the expansion of Brazilian agricultural activity by 2020:Scenario 1-expansion of cropping into areas of natural vegetation,without adoption of conservation practices;Scenario 2-expansion of cropping into areas of degraded pasture,without adoption of conservation practices;Scenario 3-expansion of cropping into areas of degraded pasture,together with conservation practices in 100%of the expanded *** worst-case scenario involves expansion of agriculture into areas of native vegetation in the Brazilian Savannah(Cerrado)and Brazilian rainforest(Amazon)biomes,and could increase total soil erosion in Brazil(currently about 800 million metric tons a year)by as much as 20%.In the best-case scenar-io,crop expansion under a conservation agriculture model would utilize currently degraded pasture,especially in the Savannah(circa 40 million hectares),reducing soil erosion in Brazil by around 20%.For this to occur,however,a national soil and water conservation policy needs to be implemented in Brazil to support a sustainable model of agriculture in which the environment can be preserved as much as possible.

关键词： Land use Conservation agriculture Degraded pasture Soil and water conservation policy