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Journal of Civil Engineering and Architecture 2024年第4期18卷 186-198页

作者： Bianca Bispo dos Reis Jorge Daniel de Melo Moura Marcos Vinício de Camargo Everaldo Pletz Graduate Program in Architecture and Urbanism Londrina State UniversityJardim Portal de Versalhes 1Londrina 86057-970PRBrazil Department of Civil Engineering Federal Technological University of Paraná(UTFPR)Apucarana 86812-460PRBrazil Retired professor Department of Structural Engineering Londrina State UniversityLondrina 86057-970PRBrazil

This article presents a study on the structural behavior of transversely prestressed laminated timber slabs,focusing on an innovative approach:vertically misaligned *** misalignment,achieved by sliding vertically the wooden lamellae rather than aligning them,enhances the slab’s cross-section moment of inertia,thereby improving load-bearing capacity and *** involved two groups of structural size specimens:one with vertically aligned lamellae(control group)and the other with misaligned lamellae(study group).Results showed the study group exhibited 42%superior stiffness and 10%less load capacity compared to the *** typically occurred individually in the lamellae,particularly in those with defects or lower modulus of elasticity,concentrated in the middle third of the slabs’free span where tensile stresses *** a higher number of failed lamellae,the study group demonstrated promising *** of prestressing bar indicated no damage at all in the thread,suggesting potential for reducing bar *** findings offer crucial insights into applying these slabs in timber construction as well as to any kind of construction.

关键词： Transversal prestressed slabs wooden construction plantation wood flexural testing design methodology

Improving the Thermal Efficiency and Performance of Refrigeration Systems:Numerical-Experimental Analysis of Minimization of Frost Formation

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Energy Engineering 2022年第5期119卷 1771-1788页

作者： Felipe Mercês Biglia Raquel da Cunha Ribeiro da Silva Fátima deMoraes Lino Kamal Abdel Radi Ismail Thiago Antonini Alves Federal University of Technology-Parana(utfpr) CuritibaBrazil Federal University of Technology-Parana(utfpr) GuarapuavaBrazil University of Campinas(UNICAMP) CampinasBrazil Federal University of Technology-Parana(utfpr) Ponta GrossaBrazil

The frost growth on cold surfaces in evaporators is an undesirable phenomenon which becomes a problem for the thermal efficiency of the refrigeration systems because the ice layer acts as a thermal insulation,drastically reducing the rate of heat transfer in the *** accumulation implies an increase in energy demand and a decrease in the performance of various components involved in the refrigeration process,reducing its efficiency and making it necessary to periodically remove the frost,resulting in expenses for the defrost *** the present work,a numerical-experimental analysis was performed in order to understand the formation process of porous ice in flat plates with different surface treatments and *** understanding is of utmost importance to minimize the formation of porous ice on cold surfaces and improve equipment efficiency and *** this context,a low-cost experimental apparatus was developed,enabling an experimental analysis of the phenomenon under *** environmental conditions evaluated are the temperature of the cold surface,roomtemperature,humidity,and air *** material of the surfaces under study are aluminum,copper,and brass with different surface finishes,designated as smooth,grooved(hydrophilic),and varnished(hydrophobic).The numerical-experimental analysis demonstrates measurements and simulations of the thickness,surface temperature,and growth rate of the porous ice layer as a function of the elapsed *** numerical results were in good agreement with the experimental results,indicating that the varnished surface,with hydrophobic characteristics,presents greater difficulty in providing the ***,the results showed that application of a coating allowed a significant reduction on the frost formation process contributing to the improvement of thermal efficiency and performance of refrigeration systems.

关键词： Frost layer growth frost thickness minimization of frost hydrophobic surface refrigeration systems

Experimental Thermal Performance of Different Capillary Structures for Heat Pipes

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Energy Engineering 2021年第1期118卷 1-14页

作者： L.Krambeck G.A.Bartmeyer D.O.Souza D.Fusão P.H.D.Santos T.Antonini Alves Federal University of Technology—Parana(utfpr) Ponta Grossa84.017-220Brazil Federal University of Technology-Parana(utfpr) Curitiba81.280-340Brazil

The temperature control in electronic packaging is the key in numerous applications,to avoid overheating and hardware *** to high capability of heat transfer,good temperature uniformity,and no power consumption,heat pipes can be widely used for heat dissipation of electronic *** paper reports an experimental thermal analysis of different capillary structures for heat *** wicks considered are metal screens,axial microgrooves,and sintered metal *** heat pipes are made of copper,a 200 mm length tube and a 9.45 mm external *** fluid used was distilled *** devices are investigated in three positions:0,90,and 270°to the horizontal under powers of 5 up to 45 *** results show that in horizontal(0°)and with the evaporator under the condenser(270°),the heat pipes showed similar ***,in the reverse condition(the position against the gravity with the evaporator above the condenser,90°),the heat pipe with sintered wick presented the best thermal performance,as it has the lowest thermal resistance and supported a higher *** that,the sintered powder capillary structure demonstrates the most homogeneous thermal behavior for every position,making the most suitable for applications susceptible to diverse inclinations.

关键词： Heat pipes capillary structure thermal performance sintered wick

REVIEW Digitalization and Big data in smart farming-a review

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Journal of Management Analytics 2021年第2期8卷 333-349页

作者： Jaqueline Iaksch Ederson Fernandes Milton Borsato Universidade Tecnológica Federal do Paraná(utfpr) CuritibaBrazil

Agriculture is facing increasing challenges due to several factors such as population growth and climate *** Farming is enabling the use of detailed digital information to guide decisions along the agricultural value *** technologies and solutions have been applied to provide alternatives to assist in information gathering and processing,and thereby contribute to increased agricultural ***,the main objective of this article is to present a bibliometric analysis regarding digitalization and Big Data applications in Smart Farming.A total of 2401 articles were found and,based on ProKnow-C methodology criteria,thirty-nine publications were selected and ***,the main solutions and opportunities about the topic were recognized aiming to direct future research.

关键词： Agriculture smart farming intelligent systems smart technologies

Structural Optimization of Metal and Polymer Ore Conveyor Belt Rollers

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Computer Modeling in Engineering & Sciences 2022年第12期133卷 601-618页

作者： Joao Pedro Ceniz Rodrigo de Sá Martins Marco Antonio Luersen Tiago Cousseau Department of Mechanical Engineering Federal University of Technology-Parana(UTFPR)Curitiba81280-340Brazil

Ore conveyor belt rollers operate in harsh environments,making them prone to premature *** service lives are highly dependent on the stress field and bearing misalignment angle,for which limit values are defined in a *** this work,an optimization methodology using metamodels based on radial basis functions is implemented to reduce themass of twomodels of *** a structural point of view,one of the rollers ismade completely of metal,while the other also has some components made of polymeric *** objective of this study is to develop and apply a parametric structural optimization methodology to minimize the mass of the two models of *** represent the mechanical behavior of the rollers,simulations were performed using the finite element *** the numerical optimization process,the variable parameters were the dimensions of the shaft and external *** geometric configuration that corresponded at the same time to the lowest mass and acceptable ranges for the stress and bearingmisalignment angle was *** the proposed methodology,a 32.3% reduction in mass was obtained for a metal roller design and an 18.9% reduction for a polymer *** both cases,the constraints were not *** the all-metal roller,the safety factors for the maximum stress and bearingmisalignment angle were 1.44 and 1.75,respectively,while for the polymer roller the corresponding figures were 1.50 and *** work describes a low-computational-cost optimization methodology for roller designs that have been little studied in the ***,the methodology could be adapted for use with other types of rollers and rollers made of different materials.

关键词： Conveyor belt rollers structural optimization surrogate models radial basis functions

Sorption and desorption behavior of residual antidepressants and caffeine in freshwater sediment and sewage sludge

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International Journal of Sediment Research 2022年第3期37卷 346-354页

作者： Ismael Laurindo Costa Junior Christiane Schinneider Machado Adelmo Lowe Pletsch Yohandra Reyes Torres Department of Chemistry Federal University of Technology-Paraná (UTFPR) Department of Chemistry State University of Midwest (UNICENTRO)

The use of antidepressants is widespread in modern times. Thus, they present a potential risk for ecosystems due to occurrence in domestic sewage containing unaltered metabolites and structures, even after the treatment plants have processed the sewage. The current research investigated the sorption and desorption of antidepressants(citalopram, venlafaxine, fluoxetine, sertraline, and amitriptyline) and caffeine from freshwater sediment and sewage sludge. The samples of freshwater sediment were collected in a river spring in an area with few anthropogenic sources of pollution and samples of sewage sludge were taken from stabilization ponds of a sewage treatment. The matrices were mainly composed of organic fractions, sediment of humic nature, and aliphatic biomolecules in sludges. The presence of silt and clay in the sediment proved to be important for the sorption process when compared to the flocs and colloidal structure of the sludge. The kinetic study indicated pseudo-first order behavior. The Freundlich isotherm was satisfactorily used in the interpretation of sorption and desorption for all analytes and matrices. The high percentages obtained for desorption suggest analyte mobility, which is more intense in the sludge than in the sediment since each matrix has a different composition. It can be considered that the information obtained here reinforces the ecotoxicological concern with respect to pharmacological residues in the environment, as processes of retention by sorption in the sludge and the sediment have been confirmed, as well as the preferential partition of some analytes by the aqueous phase.

关键词： Emerging pollutants Drugs Persistence Partition Mobility Sorption

A Finite Element Study of the Influence of Graphite Nodule Characteristics on a Subsurface Crack in a Ductile Cast Iron Matrix under a Contact Load

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Computer Modeling in Engineering & Sciences 2018年第10期117卷 59-71页

作者： Guilherme Suguinoshita Carlos Henrique da Silva Marco Antonio Luersen Department of Mechanical Engineering Federal University of Technology-Parana(UTFPR)Rua Deputado Heitor Alencar Furtado5000CEP 81280-340CuritibaBrazil

This paper describes a study of the effects of graphite nodule characteristics on a subsurface crack in austempered ductile iron(ADI).A representative specimen of ADI,subjected to sliding contact load,is modeled using finite elements aiming to obtain the shear stress intensity factor(KII).The parameters varied were(i)the nodule diameter(two different values were considered),(ii)the distance between the nodule and the tip of the crack and(iii)the position of the load relative to the tip of the *** results of the numerical simulations show that the smaller diameter nodule has a larger influence on KII,suggesting a higher contact fatigue crack propagation rate in the material with the smaller *** results are the opposite of those observed in experimental studies and would appear to indicate that other factors should be also considered to ensure realistic estimates of the contact fatigue strength of ADI.

关键词： Austempered ductile iron subsurface crack stress intensity factor finite element analysis graphite nodule

Bactericidal activity of hydrogel beads based on N,N,N-trimethyl chitosan/alginate complexes loaded with silver nanoparticles

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Chinese Chemical Letters 2015年第9期26卷 1129-1132页

作者： Alessandro F.Martins Johny P.Monteiro Elton G.Bonaf Adriana P.Gerola Cleiser T.P.Silva Emerson M.Girotto Adley F.Rubira Edvani C.Muniz Departamento de Quimica Universidade Tecnologica Federal do Parana(UTFPR) Grupo de Materials Polimericos e Compositos Universidade Estadual de Maringa(UEM)

Polysaccharide-based composite materials（beads） containing silver nanoparticles（AgNPs） were successfully *** beads acted as an efficient vehicle for Ag＊ *** promoted the AgNPs protection and inhibited their *** assays showed that the beads/AgNPs concentration can be modulated to deliver an amount of Ag＊ necessary for kill Escherichia coli cells.

关键词： N N N-Trimethyl chitosan Alginate Silver nanoparticles Antimicrobial activity Delivery

Remarks on the application of two-dimensional shape factors under severe wear conditions

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Friction 2016年第1期4卷 65-71页

作者： Giuseppe PINTAUDE Mario COSEGLIO Programa de Pós-Gradua(a)(a)o em Engenharia Mec(a)nica e de Materiais UTFPR Curitiba PR Brazil University of Birmingham Birmingham UK

The use of two-dimensional shape parameters to characterize abrasive particles is a potential approach to express their angularity. Nevertheless, in sliding abrasion, especially in pin abrasion testing, these descriptors could not be suitable for characterizing severe wear of engineering materials such as steels and cast irons. This work compares the applicability of two-dimensional shape parameters in describing severe wear of metals in recent pin abrasion tests with cases where they could have been correlated with the wear rates. Considering these aspects, this work puts in evidence the importance of clogging occurrence and the coated paper structure for a carefully application of shape parameters. In addition, it is proposed a possible relation between the shape parameters and one of the components of the abrasion factor.

关键词： wear particle shape sliding abrasion coated papers

Strategies to Promote Regional Innovation

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Chinese Business Review 2016年第10期15卷 466-478页

作者： Andriele De Pra Carvalho Paula Regina Zarelli Marco Antonio Harms Dias utfpr Francisco Beltrao Brasil UNIVALI Itajai Brasil

A favorable environment for the exchange of information and innovation is able to provide the economic and social progress. Thus, this article aims to propose a study methodology to develop strategies for promoting technological innovation, to answer the research question： What actions to leverage the innovative potential of a region？ Data were collected through qualitative and quantitative approaches. The study was characterized as exploratory, descriptive, and inventory. The study sample was composed of the industrial spectrum of Francisco Beltrao region. Innovation indexes were identified companies operating in areas of greatest economic importance. Representatives of the companies were interviewed for the researcher could analyze their knowledge of the laws that encourage innovation and actions imposed by the interested parties and the municipal government. Interested parties were also interviewed to verify the effectiveness of actions. The main results indicated a low overall rate of innovation of companies in the Francisco Beltrao region. Another point was the very low number of companies they knew about laws and incentives. The higher content of knowledge of these laws and actions of stakeholders were among the companies participating in the single business hub of the city looking for technological innovation. The main conclusions brought proposed strategies to promote technological innovation.

关键词： regional development innovation management sustainable development innovation sustainable management