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Journal of Electromagnetic Analysis and Applications 2010年第1期2卷 7-17页

作者： Afonso José do PRADO sérgio KUROKAWA José Pissolato FILHO luiz Fernando BOVOLATO 不详

Clarke’s matrix has been applied as a phase-mode transformation matrix to three-phase transmission lines substituting the eigenvector matrices. Considering symmetrical untransposed three-phase lines, an actual symmetrical three-phase line on untransposed conditions is associated with Clarke’s matrix for error and frequency scan analyses in this paper. Error analyses are calculated for the eigenvalue diagonal elements obtained from Clarke’s matrix. The eigenvalue off-diagonal elements from the Clarke’s matrix application are compared to the correspondent exact eigenvalues. Based on the characteristic impedance and propagation function values, the frequency scan analyses show that there are great differences between the Clarke’s matrix results and the exact ones, considering frequency values from 10 kHz to 1 MHz. A correction procedure is applied obtaining two new transformation matrices. These matrices lead to good approximated results when compared to the exact ones. With the correction procedure applied to Clarke’s matrix, the relative values of the eigenvalue matrix off-diagonal element obtained from Clarke’s matrix are decreased while the frequency scan results are improved. The steps of correction procedure application are detailed, investigating the influence of each step on the obtained two new phase-mode transformation matrices.

关键词： Clarke’s Matrix Eigenvector Eigenvalue Phase Mode Transformation Error Analysis Non symmetrical Lines Frequency Dependent Parameters

Melt Extrusion of Environmentally Friendly Poly(L-lactic acid)/sodium Metabisulfite Films for Antimicrobial Packaging Applications

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Journal of Renewable Materials 2021年第2期9卷 337-349页

作者： Norma M.P.Machado Gustavo C.Melo Matheus F.Camargo Giulianna G.Feijó Bruna M.s.Putton Clarice steffens Rogerio L.Cansian luiz A.Pessan Francys K.V.Moreira Department of Materials Engineering Federal University of São CarlosSão CarlosBrazil Department of Food Engineering Regional Integrated University of High Uruguay and Missions(URI)ErechimBrazil

Food packaging materials compounded with antimicrobial additives can substantially diminish the incidence of foodborne ***,poly(L-lactic acid)(PLA)films containing sodium metabisulfite(NaM)were produced by melt extrusion as an attempt to develop a new biodegradable material with antimicrobial properties for *** cycle assessment(LCA)simulations revealed that the environmental footprints of the PLA film did not change upon NaM addition,and that NaM is more eco-friendly than silver *** PLA/NaM films with NaM content varying from 0.5 to 5.0 wt.%were characterized by differential scanning calorimetry(DsC),thermogravimetric analysis(TGA),and optical and mechanical properties *** optical properties were sustained after the addition of NaM,but high NaM contents degraded the light transparence of the PLA matrix at some *** thermal stability and tensile properties of the PLA film decreased proportionally to the NaM content,while no changes were observed on Tg,Tm and Xc,as determined by *** diffusion tests revealed that the PLA/NaM films had no antimicrobial activity on saccharomyces cerevisiae at 35°C,which was related to the limited migration of NaM from the glassy PLA *** biodegradable PLA films compounded with NaM through melt extrusion display adequate optical,thermal,and mechanical properties to cover most food packaging applications,representing an essential step toward the development of eco-friendly packaging materials that can potentially exhibit an antimicrobially active surface.

关键词： Biobased packaging antimicrobial activity life cycle assessment

statistical Estimation of surface Heat Control and Exchange in Endotherms

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Open Journal of statistics 2018年第1期8卷 220-239页

作者： Barbara Henning Benilton de sá Carvalho José luiz Boldrini sérgio Furtado dos Reis Denis Otávio Vieira de Andrade Programa de Pós-Graduacao em Ecologia Universidade Estadual de Campinas Campinas Brazil Departamento de Estatística Universidade Estadual de Campinas Campinas Brazil Departamento de Matemática Universidade Estadual de Campinas Campinas Brazil Departamento de Biologia Animal Universidade Estadual de Campinas Campinas Brazil Departamento de Zoologia Universidade Estadual Paulista Rio Claro Brazil

In this paper, we combine polynomial functions, Generalized Estimating Equations, and bootstrap-based model selection to test for signatures of linear or nonlinear relationships between body surface temperature and ambient temperature in endotherms. Linearity or nonlinearity is associated with the absence or presence of cutaneous vasodilation and vasoconstriction, respectively. We obtained experimental data on body surface temperature variation from a mammalian model organism as a function of ambient temperature using infrared thermal imaging. The statistical framework of model estimation and selection successfully detected linear and nonlinear relationships between body surface temperature and ambient temperature for different body regions of the model organism. These results demonstrate that our statistical approach is instrumental to assess the complexity of thermoregulation in endotherms.

关键词： Gracilinanus microtarsus Infrared Thermography Thermal Window Thermoregulation in Homeothermic Endotherms Vasomotor Adjustment

Nanostructured 3-D Collagen/Nanotube Biocomposites for Future Bone Regeneration scaffolds

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Nano Research 2009年第6期2卷 462-473页

作者： Edelma E.da silva Heloisa H.M.Della Colleta Andre s.Ferlauto Roberto L.Moreira Rodrigo R.Resende sergio Oliveira Gregory T.Kitten Rodrigo G.Lacerda luiz O.Ladeira Universidade Federal de Minas Gerais Departamento de FísicaLaboratório de NanomateriaisAv.Antônio Carlos662730123-970Belo HorizonteMGBrazil Universidade Federal de Minas Gerais Departamento de MorfologiaAv.Antônio Carlos662730123-970Belo HorizonteMGBrazil

The fi eld of bionanotechnology has been rapidly growing during the last few years and we can now envision a controllable integration between biological and artificial matter,where new biomimetic structures with a wide range of chemical and physical properties will promote the development of a novel generation of medical *** this work we describe a collagen/carbon nanotube composite which has the potential to be used as a scaffold for tissue *** this biocomposite incorporates the advantageous properties of both collagen and carbon nanotubes,it has most of the characteristics that an ideal biomaterial requires in order to be used as an osteoinductive *** biocomposite is bioresorbable and biodegradable and has the desired mechanical rigidity while maintaining a three-dimensional(3-D)nanostructured *** stability and swelling were achieved under fluid environments by varying the amount of carbon nanotubes(CNTs)incorporated into the *** variations can dictate the degree of interaction between fibroblastic cells and the ***-of-concept was shown by performing an in vitro induced mineralization of hydroxylapatite crystals under physiological ***,the ability to attach biofunctional groups to the CNT walls can open a new road for tissue regeneration since the combination of CNTs with specific growth factors or cellular ligands can create an environment capable of signaling and infl uencing specifi c cell *** observations suggest that collagen/carbon nanotube biocomposites will have important uses in a wide range of biotechnological areas.

关键词： Biomaterials carbon nanotubes collagen tissue engineering biocompatibility

The Influence of Window Length Analysis on the Time and Frequency Domain of Mechanomyographic and Electromyographic signals of submaximal Fatiguing Contractions

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Open Journal of Biophysics 2013年第3期3卷 178-190页

作者： guilherme Nogueira-Neto Eduardo scheeren Eddy Krueger Percy Nohama Vera Lucia s.N.Button Departamento de Engenharia Biomedica/CEB Universidade Estadual de Campinas-UNICAMPCampinasBrazil Laboratorio de Engenharia de Reabilitacao Pontificia Universidade Catolica do Parana-PUCPRCuritibaBrazil CPGEI Universidade Tecnologica Federal do Parana-UTFPRCuritibaBrazil

Mechanomyography (MMG) acquires the oscillatory waves of contracting muscles. Electromyography (EMG) is a tool for monitoring muscle overall electrical activity. During muscle contractions, both techniques can investigate the changes that occur in the muscle properties. EMG and MMG parameters have been used for detecting muscle fatigue with diverse test protocols, sensors and filtering. Depending on the analysis window length (WLA), monitoring physiological events could be compromised due to imprecision in the determination of parameters. Therefore, this study investigated the influence of WLA variation on different MMG and EMG parameters during submaximal isometric contractions monitoring MMG and EMG parameters. Ten male volunteers performed isometric contractions of elbow joint. Triaxial accelerometer-based MMG sensor and EMG electrodes were positioned on the biceps brachii muscle belly. Torque was monitored with a load cell. Volunteers remained seated with hip and elbow joint at angles of 110° and 90°, respectively. The protocol consisted in maintaining torque at 70% of maximum voluntary contraction as long as they could. Parameter data of EMG and the modulus of MMG were determined for four segments of the signal. statistical analysis consisted of analyses of variance and Fisher’s least square differences post-hoc test. Also, Pearson’s correlation was calculated to determine whether parameters that monitor similar physiological events would have strong correlation. The modulus of MMG mean power frequency (MPF) and the number of crossings in the baseline could detect changes between fresh and fatigued muscle with 1.0 s WLA. MPF and the skewness of the spectrum (μ3), parameters related to the compression of the spectrum, behaved differently when monitored with a triaxial MMG sensor. The EMG results show that for the 1.0 s and 2.0 s WLAs have normalized RMs difference with fatigued muscle and that there was strong correlation between parameters of different domains.

关键词： Mechanomyography Electromyography Window Length Analysis Local Muscle Fatigue

Can Brazil Become a Green Hydrogen Powerhouse?

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Journal of Power and Energy Engineering 2020年第11期8卷 21-32页

作者： Rafael Kelman Luana de s. Gaspar Florian s. Geyer luiz A. N. Barroso Mario V. F. Pereira PsR-Energy Consulting and Analytics Rio de Janeiro Brazil Consultant of Renewable Energy and Green Hydrogen MSc/VU Amsterdam and MBA in Renewables/Beuth University Berlin Germany

This paper assesses the feasibility of green hydrogen production in Brazil. By green hydrogen, it is meant the hydrogen produced by the electrolysis of water by consuming electricity produced by renewable sources. The... 详细信息

This paper assesses the feasibility of green hydrogen production in Brazil. By green hydrogenspan>, it is meant the hydrogen produced by the electrolysis of water by consuming electricity produced by renewable sources. The country has large areas with high solar irradiation and favorable wind velocities that help to make wind power and solar PV economical alternatives. Other factors include lower investments and lower grid integration cost with respect to global average, because of the large share of hydropower. As known, hydro plants respond well to the short-term variability of renewable production. Local regulations also incentivize renewable energy. For example, it is possible, according to market rules, for a hydrogen producer to sign a financial Power Purchase Agreement (PPA) contract with a producer or trader to secure a firm,span style="font-family:Verdana;"> renewable energy supply for the electrolysis process. This market-driven factor, and other key factors, such as low price of electricity, are considered in an economic feasibility model. Results from this model suggest that Brazil could become a green hydrogen powerhouse for the internal market and potential exports to Germany and other European countries.

关键词： Green Hydrogen strategy Brazil Export

Numerical Analysis and study of the Dynamic Response of structural systems for Machinery Foundations

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Journal of Civil Engineering and Architecture 2020年第11期14卷 595-602页

作者： Douglas M.C.Rodrigues Rodrigo B.Burgos Joséguilherme s.da silva Civil Engineering Graduate Programme(PGECIV) State University of Rio de Janeiro(UERJ)Rio de Janeiro20550-900Brazil structural Engineering Department(EsTR) State University of Rio de Janeiro(UERJ)Rio de Janeiro20550-900Brazil

This work aims the deterministic dynamic analysis,in the time and frequency domain,of a reinforced concrete floor supported by a pre-cast pile foundation system,when subjected to the excitation produced by a large compressor installed in an industry for the production of air *** concrete slab presents a dimension of 12 m×15 m,required to support a compressor-motor assembly weighting 1,900 kN and positioned at a height of 4m of the investigated concrete *** this investigation,two numerical models were developed and the difference between these models is characterized by the discretization of the support points(pre-cast concrete piles).The developed numerical model adopted the usual mesh refinement techniques present in finite element method simulations implemented in the Csi sAP2000 V.17.2.0 *** on the developed analysis methodology,the dynamic structural response of the foundation system is evaluated in terms of natural frequencies,vibration modes,displacements,velocities,and *** maximum values of the dynamic response of the system are compared with the limit values recommended by standards and project recommendations,aiming a careful evaluation,regarding the performance of the structure in terms of excessive vibrations and the economic aspects involved in the design of the foundation ***,the obtained results of the two developed numerical models are compared,as to evaluate if there are benefits in refining the support points modelling.

关键词： Machinery foundation structural dynamics numerical analysis

Tributyrin in the Diet of Lambs and Its Impacts on Energy Metabolism and Oxidative status in the Liver and Intestine, as Well as the Fatty Acid Profile in Meat

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Food and Nutrition sciences 2024年第11期15卷 1065-1084页

作者： Ana Iris s. dos santos Julcemar D. Kessler Bruna Klein Andrei L. R. Brunetto guilherme L. Deolindo luiz Eduardo L. silva Roger Wagner Poliheny Martins da silva Matheus D. Baldissera Aleksandro s. da silva Programa de Ps-graduao Zootecnia Universidade do Estado de Santa Catarina (UDESC) Chapec Brasil Departamento de Zootecnia Universidade do Estado de Santa Catarina (UDESC) Chapec Brasil Programa de Ps-graduao Multicntrico em Bioqumica e Biologia Molecular Universidade do Estado de Santa Catarina (UDESC) Lages Brasil Departamento de Cincia de Alimentos Universidade Federal de Santa Maria Santa Maria Brasil Laboratrio de Bioprospeco e Biologia Experimental Universidade Franciscana (UFN) Santa Maria Brasil

This study aimed to determine whether adding tributyrin to the diet of lambs impacts health, energy metabolism, ruminal environment, and meat quality. Twelve lambs were used;the control group received a basal diet, while the tributyrin group received a diet with the additive mixed with concentrate (2 g/day/animal). The blood count was used for Leukocyte and lymphocyte counts, which were significantly higher in tributyrin-fed animals than in controls. The activity of the enzymes adenylate kinase and pyruvate kinase was higher in the liver and intestine of the tributyrin group than the controls;cytosolic creatine kinase activity was significantly higher in the intestine of lambs fed tributyrin. Glutathione s-transferase activity in the liver was significantly higher in animals in the tributyrin group. superoxide dismutase activity was significantly higher in the intestine, with a lower protein carbonyl concentration in the tributyrin group. Bacterial activity through ruminal fluid collection was significantly lower when tributyrin was consumed, unlike the protozoan count, which was significantly higher in animals in the tributyrin group than in the controls. Tributyrin intake caused lower levels of short-chain fatty acids without changing the proportion of volatile fatty acids. The water retention capacity measured using an external compression method was significantly higher in the meat of the tributyrin group. The treatment affected some fatty acids in the meat, these acids were separated by chromatography where a lower amount of saturated fatty acids and a higher amount of monounsaturated fatty acids in the group that consumed tributyrin. These findings suggest that tributyrin in lamb diet alters blood and rumen environment biomarkers and improves the fatty acid profile of the meat.

关键词： Additive Animal Production Tributyrin Fatty Acids Animal Health

starch Digestibility and Functional Properties of Rice starch subjected to Gamma Radiation

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Rice science 2018年第1期25卷 42-51页

作者： Luís Fernando POLEsI silene Bruder silveira sARMENTO solange Guidolin CANNIATTI-BRAZACA Center for Nuclear Energy in Agriculture University of Sao Paulo Department of Food Engineering Federal University of Rondonia Department of Agri-Food Industry Food and NutritionLuiz de Queiroz College of AgricultureUniversity of Sao Paulo

This study investigated the effect of gamma radiation on the digestibility and functional properties of rice *** cultivars IRGA417 and IAC202 were used for isolation of starch by the alkaline *** samples were irradiated with 1,2 and 5 k Gy doses of ^(60)Co at a rate of 0.4 k Gy/h.A control sample,which was not irradiated,was used for *** and control starches were characterized by in vitro starch digestibility,total dietary fiber,color,water absorption index,water solubility index,syneresis,swelling factor,amylose leaching,pasting properties and gel *** changed starch digestibility differently in either *** radiation doses promoted increase in the color parameter b*(yellow),elevation in the capacity to absorb water,and solubility in water as well as the amylose leached from granules for both *** properties showed a decrease that was proportional to the dose applied,caused by the depolymerization of starch *** firmness of the starch from IAC202 was inversely proportional to the radiation dose applied,whereas for IRGA417,there was a reduction at 5 k Gy *** starches can be modified by irradiation to exhibit different functional characteristics and they can be used by the food industries in products such as soups,desserts,flans,puddings and others.

关键词： Oryza sativa irradiation viscosity swelling amylose starch digestibility

On the Bump Tests of Cracked shafts Using Acoustic Emission Techniques

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Engineering（科研） 2016年第9期8卷 572-581页

作者： Gilberto luiz s. Pimentel-Junior Frederico B. Oliveira Marco Tulio C. Faria Department of Mechanical Engineering Universidade Federal de Minas Gerais Belo Horizonte Brazil

An investigation about the application of Acoustic Emission (AE) techniques to analyze the dynamic response of different cracked shafts rendered in bump tests is presented in this work. The experimental apparatus devised for this work complies of six shafts with different transverse crack sizes and a high-frequency data acquisition system. The AE signals generated in the bump tests performed on the different cracked shafts are captured by a wideband AE transducer. Those signals are treated by using statistical moments, wavelet transforms, and frequency- and time-domain procedures. A transverse crack of predetermined depth is etched into each shaft. The experimental results show that the values of kurtosis and skewness estimated for the AE signals can be used to identify the crack size.

关键词： Acoustic Emission Cracked Rotors Bump Tests shaft Crack