The roller is one of the fundamental elements of ore belt conveyor systems since it supports,guides,and directs material on the belt.This component comprises a body(the external tube)that rotates around a fixed shaft ...The roller is one of the fundamental elements of ore belt conveyor systems since it supports,guides,and directs material on the belt.This component comprises a body(the external tube)that rotates around a fixed shaft supported by easels.The external tube and shaft of rollers used in ore conveyor belts are mostly made of steel,resulting in high mass,hindering maintenance and replacement.Aiming to achieve mass reduction,we conducted a structural optimization of a roller with a polymeric external tube(hereafter referred to as a polymeric roller),seeking the optimal values for two design parameters:the inner diameter of the external tube and the shaft diameter.The optimization was constrained by admissible values for maximum stress,maximum deflection and misalignment angle between the shaft and bearings.A finite element model was built in Ansys Workbench to obtain the structural response of the system.The roller considered is composed of an external tube made of high-density polyethylene(HDPE),bearing seats of polyamide 6(PA6),and a steel shaft.To characterize the polymeric materials(HDPE and PA6),stress relaxation tests were conducted,and the data on shear modulus variation over time were inserted into the model to calculate Prony series terms to account for viscoelastic effects.The roller optimization was performed using surrogate modeling based on radial basis functions,with the Globalized Bounded Nelder-Mead(GBNM)algorithm as the optimizer.Two optimization cases were conducted.In the first case,concerning the roller’s initial material settings,the designs found violated the constraints and could not reduce mass.In the second case,by using PA6 in both bearing seats and the tube,a design configuration was found that respected all constraints and reduced the roller mass by 15.5%,equivalent to 5.15 kg.This study is among the first to integrate experimentally obtained viscoelastic data into the surrogate-based optimization of polymeric rollers,combining methodological innovation with industrial relevance.展开更多
Food waste and by-products are generated throughout the food processing and storage chain.In a world facing climate collapse and limited space for expanding cultivable land needed to feed a growing global population,u...Food waste and by-products are generated throughout the food processing and storage chain.In a world facing climate collapse and limited space for expanding cultivable land needed to feed a growing global population,utilizing food from sustainable production chains has become a significant challenge.Additionally,there is a worldwide trend towards consuming natural and healthy foods that are as free from chemical compounds as possible during production,processing,and preparation.Gradually,eating habits have adapted to these new trends,and new foods are being introduced into diets.In this context,research into sustainable practices has emerged worldwide,promoting the increased consumption of plant-based foods.The central idea of this article is connected to global concerns regarding food sources,minimizing waste,and innovatively using every ingredient.Fermentation,a traditional and natural food preservation technique,can be a vital tool for enhancing flavours and textures while increasing nutritional value through the action of specific enzymes.This article aims to highlight the main challenges of using food processing by-products in human nutrition and explore possible strategies to improve their quality through the enzymatic action of microorganisms.展开更多
An individual's mental health influences their capacity to think effectively,feel emotionally stable,and perform daily activities.As mental health concerns become more prevalent worldwide,new awareness and diagnos...An individual's mental health influences their capacity to think effectively,feel emotionally stable,and perform daily activities.As mental health concerns become more prevalent worldwide,new awareness and diagnostic and treatment tactics are needed.Digital tools and technology are helping solve these problems by providing scalable,tailored solutions for large populations.This detailed review examines mental health‐promoting internet tools.Smartphone applications,web‐based therapy systems,wearable tech,artificial intelligence‐powered resources,and virtual reality(VR)technologies were evaluated for efficacy and side effects.PubMed,PsycINFO,Scopus,IEEE Xplore,and Google Scholar were carefully searched.Search terms included“digital mental health tools,”“online therapy,”and“AI in mental health.”Randomized controlled trials,cohort studies,cross‐sectional studies,systematic reviews,and meta‐analyses of digital technology and mental health were included from among the literature published after 2010.Cognitive behavioral therapy methods,mood monitoring,and mindfulness exercises are among the numerous features of smartphone applications that have been demonstrated to mitigate symptoms of anxiety,depression,and tension.Online therapy platforms let marginalized individuals obtain therapy remotely.Wearable technology may detect heart rate,blood pressure,and sleep length,which may reveal mental health difficulties.Chatbots employ machine learning algorithms and natural language processing to deliver customized support and show promise for quick intervention.Exposure therapy for anxiety and trauma is increasingly using virtual reality environments.Although digital mental health therapies face challenges in relation to data privacy,limited long‐term efficacy,and technological inequality,digital technologies are modernizing mental healthcare.By offering inexpensive and effective alternatives to traditional therapies,digital technologies may help healthcare systems meet the growing demand for mental health services and overall well‐being.展开更多
The temperature control in electronic packaging is the key in numerous applications,to avoid overheating and hardware failure.Due to high capability of heat transfer,good temperature uniformity,and no power consumptio...The temperature control in electronic packaging is the key in numerous applications,to avoid overheating and hardware failure.Due to high capability of heat transfer,good temperature uniformity,and no power consumption,heat pipes can be widely used for heat dissipation of electronic components.This paper reports an experimental thermal analysis of different capillary structures for heat pipes.The wicks considered are metal screens,axial microgrooves,and sintered metal powder.The heat pipes are made of copper,a 200 mm length tube and a 9.45 mm external diameter.Working fluid used was distilled water.The devices are investigated in three positions:0,90,and 270°to the horizontal under powers of 5 up to 45 W.The results show that in horizontal(0°)and with the evaporator under the condenser(270°),the heat pipes showed similar results.Nevertheless,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 power.Besides 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.展开更多
Polysaccharide-based composite materials（beads） containing silver nanoparticles（AgNPs） were successfully prepared.Hydrogel beads acted as an efficient vehicle for Ag＊ delivery.Beads promoted the AgNPs protection ...Polysaccharide-based composite materials（beads） containing silver nanoparticles（AgNPs） were successfully prepared.Hydrogel beads acted as an efficient vehicle for Ag＊ delivery.Beads promoted the AgNPs protection and inhibited their aggregation.Antimicrobial assays showed that the beads/AgNPs concentration can be modulated to deliver an amount of Ag＊ necessary for kill Escherichia coli cells.展开更多
DC plasma is a very promising technology for processing different materials, and is becoming especially interesting when low environmental impact and high-performance treatments are needed. Some of the intrinsic chara...DC plasma is a very promising technology for processing different materials, and is becoming especially interesting when low environmental impact and high-performance treatments are needed. Some of the intrinsic characteristics of DC plasma technology, which make it suitable for powder metallurgy （PM） and powder injection molding （PIM） parts production, are low- pressure processing and plasma environment high reactivity. Moreover it can be considered as a highly competitive green technology. In this work, an overview of some of the important DC plasma techniques applied to PM and PIM parts processing is presented. Emphasis is given to the descriptions of the main characteristics and the technique potentials of plasma-assisted nitriding, plasma-assisted thermal debinding, plasma-assisted sintering, and simultaneously plasma-assisted sintering and surface alloying. The aspects presented and discussed in this paper indicate that DC plasma processes are promising and competitive techniques for PM and PIM parts processing.展开更多
Management of discarded tires is a compelling environmental issue worldwide.Although there are several approaches developed to recycle waste tire rubbers,their application in solid-state cooling is still unexplored.Co...Management of discarded tires is a compelling environmental issue worldwide.Although there are several approaches developed to recycle waste tire rubbers,their application in solid-state cooling is still unexplored.Considering the high barocaloric potential verified for elastomers,the use of waste tire rubber(WTR)as a refrigerant in solid-state cooling devices is very promising.Herein,we investigated the barocaloric effects in WTR and polymer blends made of vulcanized natural rubber(VNR)and WTR,to evaluate its feasibility for solid-state cooling technologies.The adiabatic temperature changes and the isothermal entropy changes reach giant values,as well as the performance parameters,being comparable or even better than most barocaloric materials in literature.Moreover,pure WTR and WTR-based samples also present a faster thermal exchange than VNR,consisting of an additional advantage of using these discarded materials.Thus,the present findings evidence the encouraging perspectives of employing waste rubbers in solid-state cooling based on barocaloric effects,contributing to both the recycling of polymers and the sustainable energy technology field.展开更多
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...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 crack.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 nodule.These 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.展开更多
The study evaluated the effect of sodium chloride (1.5%), sodium erythorbate (0.5% and 1.0%) and ascorbic acid (0.1% and 0.2%) on inhibiting lipid oxidation in mechanically deboned chicken meat (MDCM). The peroxide, a...The study evaluated the effect of sodium chloride (1.5%), sodium erythorbate (0.5% and 1.0%) and ascorbic acid (0.1% and 0.2%) on inhibiting lipid oxidation in mechanically deboned chicken meat (MDCM). The peroxide, acidity, pH, color and odor values of the samples were determined on the 1st, 3rd and 5th days. Treatments with sodium erythorbate and ascorbic acid had significant influence (p ≤ 0.05) on the peroxide, acidity and pH values. Ascorbic acid and erythorbate sodium were especially effective in reducing lipid oxidation in mechanically deboned chicken meat.展开更多
Ore conveyor belt rollers operate in harsh environments,making them prone to premature failure.Their service lives are highly dependent on the stress field and bearing misalignment angle,for which limit values are def...Ore conveyor belt rollers operate in harsh environments,making them prone to premature failure.Their service lives are highly dependent on the stress field and bearing misalignment angle,for which limit values are defined in a standard.In this work,an optimization methodology using metamodels based on radial basis functions is implemented to reduce themass of twomodels of rollers.From a structural point of view,one of the rollers ismade completely of metal,while the other also has some components made of polymeric material.The objective of this study is to develop and apply a parametric structural optimization methodology to minimize the mass of the two models of rollers.To represent the mechanical behavior of the rollers,simulations were performed using the finite element method.During the numerical optimization process,the variable parameters were the dimensions of the shaft and external tube.The geometric configuration that corresponded at the same time to the lowest mass and acceptable ranges for the stress and bearingmisalignment angle was determined.With the proposed methodology,a 32.3% reduction in mass was obtained for a metal roller design and an 18.9% reduction for a polymer roller.In both cases,the constraints were not violated.For 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 2.23.This work describes a low-computational-cost optimization methodology for roller designs that have been little studied in the literature.Furthermore,the methodology could be adapted for use with other types of rollers and rollers made of different materials.展开更多
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,drastica...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 system.Its 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 process.In 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 parameters.This understanding is of utmost importance to minimize the formation of porous ice on cold surfaces and improve equipment efficiency and performance.In this context,a low-cost experimental apparatus was developed,enabling an experimental analysis of the phenomenon under study.The environmental conditions evaluated are the temperature of the cold surface,roomtemperature,humidity,and air velocity.The 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 time.The numerical results were in good agreement with the experimental results,indicating that the varnished surface,with hydrophobic characteristics,presents greater difficulty in providing the phenomenon.Therefore,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.展开更多
In view of the growth of retail, as well as the performance of large multinational supermarket branch in the Brazilian market, the purpose of this article is an analysis of the strategies of Casino, Carrefour, Walmart...In view of the growth of retail, as well as the performance of large multinational supermarket branch in the Brazilian market, the purpose of this article is an analysis of the strategies of Casino, Carrefour, Walmart and open in the country capital, analyzing their operational, financial indicators socio-environmental initiatives. In order to achieve the main objective of this work, the construction of a method that validates this search was necessary. The main strategies and indicators of the three groups in four areas： corporate strategy, operational areo, financial areo, social and environmental issue, were analyzed. Study of qualitative, descriptive and exploratory character is realised through the importance of these three companies worldwide. As conclusions, it has been the expansion strategies that geared toward developing countries, adherence to new store formats, specializing in electronic commerce, as well as the superiority of Walmart （net sales） and Casino （Profitability）.展开更多
Objectives: The overall aim is to propose a general framework to build any kind of interactive digital atlas. It can be used either as pedagogical support to study human anatomy or as a tool to aid health professional...Objectives: The overall aim is to propose a general framework to build any kind of interactive digital atlas. It can be used either as pedagogical support to study human anatomy or as a tool to aid health professionals improving the quality of the human resources formation. Methods: To illustrate the use of the proposed methodology was build an atlas of intracranial human anatomy. We used 3D surface rendering techniques to create a brain atlas that would allow us to correlate bi-dimensional MRI images with 3D brain structures. Results: The system was coded in Java and distributed under GNU/GLP license, making it available to use and/or to expand and serve as an educational tool allow medical students to use it to evaluate the special relationships among structures. Conclusions: The characteristics of the obtained Atlas are essential in the Brazilian public health context, where professionals in several different geographical locations (submitted to distinct informatics infrastructure) need to be trained.展开更多
In a preceding work we have reported experiments showing that an hydroalcoholic exctract of Agaricus blazei is able to exert purinergic effects in the isolated perfused rat liver when it is infused into the portal vei...In a preceding work we have reported experiments showing that an hydroalcoholic exctract of Agaricus blazei is able to exert purinergic effects in the isolated perfused rat liver when it is infused into the portal vein in monovascular perfusion (entry: portal vein;exit: hepatic vein). In the present communication we are presenting and discussing experiments done with the bivascularly perfused rat liver (entry: portal vein + hepatic artery;exit: hepatic vein) in order to verify if the hemodynamic effects also occur in the arterial bed. It was found that the A. blazei extract is also active when infused into the hepatic arterial bed, with differences in both sensitivity and nature of the effects on either perfusion pressure or oxygen consumption. Constriction of the arterial bed required much higher concentrations of the extract than the portal bed. The kinetics of the response was also different, with a biphasic instead of a monophasic response. These results provide a promising starting point for future studies aiming to bring to light more mechanistic details about these and possibly other effects.展开更多
Toward improving reforestation of Brazilian pine(Araucaria angustifolia),two contrasting sapling sizes in either full sun or in the shade of a mixed plantation and the effect of opening the canopy were evaluated for s...Toward improving reforestation of Brazilian pine(Araucaria angustifolia),two contrasting sapling sizes in either full sun or in the shade of a mixed plantation and the effect of opening the canopy were evaluated for survival,growth,gas exchange,photosynthetic pigments,and leaf anatomy 18 months after being planted.At 23 months after planting,a partial opening was made in the canopy in the mixed plantation,then the saplings were evaluated again after 2 months for the same morphophysiological traits.After 18 months,saplings planted in the full sun had higher survival,growth,pigments,and photosynthesis compared to the shaded saplings.Large saplings had higher survival and growth compared to the small ones.Shaded leaves were thinner and little differentiation of palisade parenchyma and hypodermis.After opening of the canopy,photo synthetically active radiation was 10 times higher,and the saplings quickly grew in height due to increased photosynthesis.Thus,although the species can tolerate shade,growth in the shade is limited.We recommend that for reforestation purposes of Brazilian pine,large saplings should be selected and planted in the open for better development.展开更多
The aim of the present study was to present the wealth, ecological characteristics and the floristic similarity of ferns and lycophytes from two forest areas of the municipality of Campo Mour?o, PR, Brazil. The vegeta...The aim of the present study was to present the wealth, ecological characteristics and the floristic similarity of ferns and lycophytes from two forest areas of the municipality of Campo Mour?o, PR, Brazil. The vegetation of the municipality is characterized mainly by an ecotone between the Seasonal Semideciduous Forest and Mixed Ombrophilous Forest. We recorded 56 species, distributed in 31 genera and 16 families. The most representative families were Pteridaceae (14) and Polypodiaceae (11) and the wealthier genre was Thelypteris (6). The terricolous species were predominant (72%) and the preferential environments were riparian vegetation and forest interior (70%). The flora of Campo Mour?o was more similar to the studies conducted in the state of Rio Grande do Sul, and the cophenetic correlation coefficient (r = 0.9058) showed a consistent adjust. In the principal components analysis (PCA) the variance explained by the two principal components was 72.99%. The wealth found in this study corresponds to approximately 11.4% of the flora of ferns and lycophytes of Paraná. Future contributions are needed to increase the knowledge about the flora of ferns and lycophytes in areas of ecotone, mainly in the region of Campo Mour?o, where the studies are scarce.展开更多
Techniques of production of enthomopatogenic bacteria are developed aiming to increase the productivity and to reduce the costs of the fermentative process. Like this, it has been using agroindustrial wastes or by-pro...Techniques of production of enthomopatogenic bacteria are developed aiming to increase the productivity and to reduce the costs of the fermentative process. Like this, it has been using agroindustrial wastes or by-products as nutrient sources in culture medium, having been used, in this study, the manipueira, a by-product of the processing of the cassava flour. Fermentations were performed in flasks of Erlenmeyer of 500 mL containing 250 mL of culture media, conditioned in shaker at 180 r.p.m. and 28°C, and the media were composed by manipueira, in concentrations that varied between 400 and 1000 mL/L. The time of the process varied between 48 and 120 hours. They appraised the following parameters: cellular growth, the production of spores, the reduction of organic matter (COD analysis) and the variation of reduction sugar. Although there was a proportional cellular growth to the manipueira concentration, the production of spores was similar in all the cases, at the end of the process, in spite of the smallest speed of production of the same ones in the highest concentrations. In relation to the variation of COD, it has, also, a percentile minor of reduction in the highest concentrations. In the analysis of variation of reduction sugars, the higher concentrations are the ones that they present larger slowness in the reduction of this.展开更多
This article presents a study on the structural behavior of transversely prestressed laminated timber slabs,focusing on an innovative approach:vertically misaligned lamellae.This misalignment,achieved by sliding verti...This article presents a study on the structural behavior of transversely prestressed laminated timber slabs,focusing on an innovative approach:vertically misaligned lamellae.This 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 stiffness.Testing 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 control.Failures 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 peak.Despite a higher number of failed lamellae,the study group demonstrated promising performance.Analysis of prestressing bar indicated no damage at all in the thread,suggesting potential for reducing bar diameter.These findings offer crucial insights into applying these slabs in timber construction as well as to any kind of construction.展开更多
Nonlinear system identification concerns the determination of the model structure and its parameters.Although the designers often seek the best model for each system,it can be tricky to determine,at the same time,the ...Nonlinear system identification concerns the determination of the model structure and its parameters.Although the designers often seek the best model for each system,it can be tricky to determine,at the same time,the best structure and the parameters which optimize the model performance.This paper proposes the use of a Genetic Algorithm,GA,and the Levenberg-Marquardt,LM,method to obtain the model parameters,as well as perform the order reduction of the model.In order to validate the proposed methodology,the identification of a magnetic levitator,operating in closed loop,was performed.The class NARX-OBF,Nonlinear Auto Regressive with eXogenous input-Orthonormal Basis Function,was used.The use of OBF functions aims to reduce the number of terms in NARX models.Once the model is found,the order reduction is performed using GA and LM,in a hybrid application,capable of determining the model parameters and reducing the original model order,simultaneously.The results show,considering the inherent trade-of between accuracy and computational effort,the proposed methodology provided an implementation with good mean square error,when compared with the full NARX-OBF model.展开更多
This paper presents a new programming paradigm named Notification Oriented Paradigm (NOP) and analyses performance aspects of NOP programs by means of an experiment. NOP provides a new manner to conceive, structure, a...This paper presents a new programming paradigm named Notification Oriented Paradigm (NOP) and analyses performance aspects of NOP programs by means of an experiment. NOP provides a new manner to conceive, structure, and execute software, which allows better performance, causal-knowledge organization, and entity decoupling than standard solutions based upon current paradigms. These paradigms are essentially Imperative Paradigm (IP) and Declarative Paradigm (DP). In short, DP solutions are considered easier to use than IP solutions thanks to the concept of high-level programming. However, they are considered slower to execute and lesser flexible to program than IP. Anyway, both paradigms present similar drawbacks like causal-evaluation redundancies and strongly coupled entities, which decrease software performance and processing distribution feasibility. These problems exist due to an orientation to monolithic inference mechanism based upon sequential evaluation by means of searches over passive computational entities. NOP proposes another manner to structure software and make its inferences, which is based upon small, smart, and decoupled collaborative entities whose interaction happen by means of precise notifications. This paper discusses NOP as a paradigm and presents certain comparison of NOP against IP. Actually, performance is evaluated by means of IP and NOP programs with respect to a same application, which allow demonstrating NOP superiority.展开更多
基金funded by Vale S.A.company(www.vale.com)and the Institute of Technology Vale(ITV—www.itv.org),grant number SAP 4600048682.
文摘The roller is one of the fundamental elements of ore belt conveyor systems since it supports,guides,and directs material on the belt.This component comprises a body(the external tube)that rotates around a fixed shaft supported by easels.The external tube and shaft of rollers used in ore conveyor belts are mostly made of steel,resulting in high mass,hindering maintenance and replacement.Aiming to achieve mass reduction,we conducted a structural optimization of a roller with a polymeric external tube(hereafter referred to as a polymeric roller),seeking the optimal values for two design parameters:the inner diameter of the external tube and the shaft diameter.The optimization was constrained by admissible values for maximum stress,maximum deflection and misalignment angle between the shaft and bearings.A finite element model was built in Ansys Workbench to obtain the structural response of the system.The roller considered is composed of an external tube made of high-density polyethylene(HDPE),bearing seats of polyamide 6(PA6),and a steel shaft.To characterize the polymeric materials(HDPE and PA6),stress relaxation tests were conducted,and the data on shear modulus variation over time were inserted into the model to calculate Prony series terms to account for viscoelastic effects.The roller optimization was performed using surrogate modeling based on radial basis functions,with the Globalized Bounded Nelder-Mead(GBNM)algorithm as the optimizer.Two optimization cases were conducted.In the first case,concerning the roller’s initial material settings,the designs found violated the constraints and could not reduce mass.In the second case,by using PA6 in both bearing seats and the tube,a design configuration was found that respected all constraints and reduced the roller mass by 15.5%,equivalent to 5.15 kg.This study is among the first to integrate experimentally obtained viscoelastic data into the surrogate-based optimization of polymeric rollers,combining methodological innovation with industrial relevance.
文摘Food waste and by-products are generated throughout the food processing and storage chain.In a world facing climate collapse and limited space for expanding cultivable land needed to feed a growing global population,utilizing food from sustainable production chains has become a significant challenge.Additionally,there is a worldwide trend towards consuming natural and healthy foods that are as free from chemical compounds as possible during production,processing,and preparation.Gradually,eating habits have adapted to these new trends,and new foods are being introduced into diets.In this context,research into sustainable practices has emerged worldwide,promoting the increased consumption of plant-based foods.The central idea of this article is connected to global concerns regarding food sources,minimizing waste,and innovatively using every ingredient.Fermentation,a traditional and natural food preservation technique,can be a vital tool for enhancing flavours and textures while increasing nutritional value through the action of specific enzymes.This article aims to highlight the main challenges of using food processing by-products in human nutrition and explore possible strategies to improve their quality through the enzymatic action of microorganisms.
文摘An individual's mental health influences their capacity to think effectively,feel emotionally stable,and perform daily activities.As mental health concerns become more prevalent worldwide,new awareness and diagnostic and treatment tactics are needed.Digital tools and technology are helping solve these problems by providing scalable,tailored solutions for large populations.This detailed review examines mental health‐promoting internet tools.Smartphone applications,web‐based therapy systems,wearable tech,artificial intelligence‐powered resources,and virtual reality(VR)technologies were evaluated for efficacy and side effects.PubMed,PsycINFO,Scopus,IEEE Xplore,and Google Scholar were carefully searched.Search terms included“digital mental health tools,”“online therapy,”and“AI in mental health.”Randomized controlled trials,cohort studies,cross‐sectional studies,systematic reviews,and meta‐analyses of digital technology and mental health were included from among the literature published after 2010.Cognitive behavioral therapy methods,mood monitoring,and mindfulness exercises are among the numerous features of smartphone applications that have been demonstrated to mitigate symptoms of anxiety,depression,and tension.Online therapy platforms let marginalized individuals obtain therapy remotely.Wearable technology may detect heart rate,blood pressure,and sleep length,which may reveal mental health difficulties.Chatbots employ machine learning algorithms and natural language processing to deliver customized support and show promise for quick intervention.Exposure therapy for anxiety and trauma is increasingly using virtual reality environments.Although digital mental health therapies face challenges in relation to data privacy,limited long‐term efficacy,and technological inequality,digital technologies are modernizing mental healthcare.By offering inexpensive and effective alternatives to traditional therapies,digital technologies may help healthcare systems meet the growing demand for mental health services and overall well‐being.
文摘The temperature control in electronic packaging is the key in numerous applications,to avoid overheating and hardware failure.Due to high capability of heat transfer,good temperature uniformity,and no power consumption,heat pipes can be widely used for heat dissipation of electronic components.This paper reports an experimental thermal analysis of different capillary structures for heat pipes.The wicks considered are metal screens,axial microgrooves,and sintered metal powder.The heat pipes are made of copper,a 200 mm length tube and a 9.45 mm external diameter.Working fluid used was distilled water.The devices are investigated in three positions:0,90,and 270°to the horizontal under powers of 5 up to 45 W.The results show that in horizontal(0°)and with the evaporator under the condenser(270°),the heat pipes showed similar results.Nevertheless,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 power.Besides 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.
基金the financial support (Nos.481424/2010-5 and 308337/2013-1)
文摘Polysaccharide-based composite materials（beads） containing silver nanoparticles（AgNPs） were successfully prepared.Hydrogel beads acted as an efficient vehicle for Ag＊ delivery.Beads promoted the AgNPs protection and inhibited their aggregation.Antimicrobial assays showed that the beads/AgNPs concentration can be modulated to deliver an amount of Ag＊ necessary for kill Escherichia coli cells.
文摘DC plasma is a very promising technology for processing different materials, and is becoming especially interesting when low environmental impact and high-performance treatments are needed. Some of the intrinsic characteristics of DC plasma technology, which make it suitable for powder metallurgy （PM） and powder injection molding （PIM） parts production, are low- pressure processing and plasma environment high reactivity. Moreover it can be considered as a highly competitive green technology. In this work, an overview of some of the important DC plasma techniques applied to PM and PIM parts processing is presented. Emphasis is given to the descriptions of the main characteristics and the technique potentials of plasma-assisted nitriding, plasma-assisted thermal debinding, plasma-assisted sintering, and simultaneously plasma-assisted sintering and surface alloying. The aspects presented and discussed in this paper indicate that DC plasma processes are promising and competitive techniques for PM and PIM parts processing.
基金The authors acknowledge financial support from FAPESP(No.2012/03480-0),CNPq and CAPES.The authors also thank LNLS and CNPEM.
文摘Management of discarded tires is a compelling environmental issue worldwide.Although there are several approaches developed to recycle waste tire rubbers,their application in solid-state cooling is still unexplored.Considering the high barocaloric potential verified for elastomers,the use of waste tire rubber(WTR)as a refrigerant in solid-state cooling devices is very promising.Herein,we investigated the barocaloric effects in WTR and polymer blends made of vulcanized natural rubber(VNR)and WTR,to evaluate its feasibility for solid-state cooling technologies.The adiabatic temperature changes and the isothermal entropy changes reach giant values,as well as the performance parameters,being comparable or even better than most barocaloric materials in literature.Moreover,pure WTR and WTR-based samples also present a faster thermal exchange than VNR,consisting of an additional advantage of using these discarded materials.Thus,the present findings evidence the encouraging perspectives of employing waste rubbers in solid-state cooling based on barocaloric effects,contributing to both the recycling of polymers and the sustainable energy technology field.
文摘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 crack.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 nodule.These 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.
基金the Research Sup-port Program of the Federal Technological University of Paraná(UTFPR)-Campus Francisco Beltrão.
文摘The study evaluated the effect of sodium chloride (1.5%), sodium erythorbate (0.5% and 1.0%) and ascorbic acid (0.1% and 0.2%) on inhibiting lipid oxidation in mechanically deboned chicken meat (MDCM). The peroxide, acidity, pH, color and odor values of the samples were determined on the 1st, 3rd and 5th days. Treatments with sodium erythorbate and ascorbic acid had significant influence (p ≤ 0.05) on the peroxide, acidity and pH values. Ascorbic acid and erythorbate sodium were especially effective in reducing lipid oxidation in mechanically deboned chicken meat.
基金financed by Vale S.A.Company(www.vale.com)and the Institute of Technology Vale(ITV-www.itv.org)through the Project No.SAP 4600048682.
文摘Ore conveyor belt rollers operate in harsh environments,making them prone to premature failure.Their service lives are highly dependent on the stress field and bearing misalignment angle,for which limit values are defined in a standard.In this work,an optimization methodology using metamodels based on radial basis functions is implemented to reduce themass of twomodels of rollers.From a structural point of view,one of the rollers ismade completely of metal,while the other also has some components made of polymeric material.The objective of this study is to develop and apply a parametric structural optimization methodology to minimize the mass of the two models of rollers.To represent the mechanical behavior of the rollers,simulations were performed using the finite element method.During the numerical optimization process,the variable parameters were the dimensions of the shaft and external tube.The geometric configuration that corresponded at the same time to the lowest mass and acceptable ranges for the stress and bearingmisalignment angle was determined.With the proposed methodology,a 32.3% reduction in mass was obtained for a metal roller design and an 18.9% reduction for a polymer roller.In both cases,the constraints were not violated.For 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 2.23.This work describes a low-computational-cost optimization methodology for roller designs that have been little studied in the literature.Furthermore,the methodology could be adapted for use with other types of rollers and rollers made of different materials.
文摘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 system.Its 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 process.In 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 parameters.This understanding is of utmost importance to minimize the formation of porous ice on cold surfaces and improve equipment efficiency and performance.In this context,a low-cost experimental apparatus was developed,enabling an experimental analysis of the phenomenon under study.The environmental conditions evaluated are the temperature of the cold surface,roomtemperature,humidity,and air velocity.The 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 time.The numerical results were in good agreement with the experimental results,indicating that the varnished surface,with hydrophobic characteristics,presents greater difficulty in providing the phenomenon.Therefore,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.
文摘In view of the growth of retail, as well as the performance of large multinational supermarket branch in the Brazilian market, the purpose of this article is an analysis of the strategies of Casino, Carrefour, Walmart and open in the country capital, analyzing their operational, financial indicators socio-environmental initiatives. In order to achieve the main objective of this work, the construction of a method that validates this search was necessary. The main strategies and indicators of the three groups in four areas： corporate strategy, operational areo, financial areo, social and environmental issue, were analyzed. Study of qualitative, descriptive and exploratory character is realised through the importance of these three companies worldwide. As conclusions, it has been the expansion strategies that geared toward developing countries, adherence to new store formats, specializing in electronic commerce, as well as the superiority of Walmart （net sales） and Casino （Profitability）.
文摘Objectives: The overall aim is to propose a general framework to build any kind of interactive digital atlas. It can be used either as pedagogical support to study human anatomy or as a tool to aid health professionals improving the quality of the human resources formation. Methods: To illustrate the use of the proposed methodology was build an atlas of intracranial human anatomy. We used 3D surface rendering techniques to create a brain atlas that would allow us to correlate bi-dimensional MRI images with 3D brain structures. Results: The system was coded in Java and distributed under GNU/GLP license, making it available to use and/or to expand and serve as an educational tool allow medical students to use it to evaluate the special relationships among structures. Conclusions: The characteristics of the obtained Atlas are essential in the Brazilian public health context, where professionals in several different geographical locations (submitted to distinct informatics infrastructure) need to be trained.
文摘In a preceding work we have reported experiments showing that an hydroalcoholic exctract of Agaricus blazei is able to exert purinergic effects in the isolated perfused rat liver when it is infused into the portal vein in monovascular perfusion (entry: portal vein;exit: hepatic vein). In the present communication we are presenting and discussing experiments done with the bivascularly perfused rat liver (entry: portal vein + hepatic artery;exit: hepatic vein) in order to verify if the hemodynamic effects also occur in the arterial bed. It was found that the A. blazei extract is also active when infused into the hepatic arterial bed, with differences in both sensitivity and nature of the effects on either perfusion pressure or oxygen consumption. Constriction of the arterial bed required much higher concentrations of the extract than the portal bed. The kinetics of the response was also different, with a biphasic instead of a monophasic response. These results provide a promising starting point for future studies aiming to bring to light more mechanistic details about these and possibly other effects.
基金financed by Brazilian agencies CAPES,FUNDAÇÃO ARAUCÁRIA and CNPq.
文摘Toward improving reforestation of Brazilian pine(Araucaria angustifolia),two contrasting sapling sizes in either full sun or in the shade of a mixed plantation and the effect of opening the canopy were evaluated for survival,growth,gas exchange,photosynthetic pigments,and leaf anatomy 18 months after being planted.At 23 months after planting,a partial opening was made in the canopy in the mixed plantation,then the saplings were evaluated again after 2 months for the same morphophysiological traits.After 18 months,saplings planted in the full sun had higher survival,growth,pigments,and photosynthesis compared to the shaded saplings.Large saplings had higher survival and growth compared to the small ones.Shaded leaves were thinner and little differentiation of palisade parenchyma and hypodermis.After opening of the canopy,photo synthetically active radiation was 10 times higher,and the saplings quickly grew in height due to increased photosynthesis.Thus,although the species can tolerate shade,growth in the shade is limited.We recommend that for reforestation purposes of Brazilian pine,large saplings should be selected and planted in the open for better development.
文摘The aim of the present study was to present the wealth, ecological characteristics and the floristic similarity of ferns and lycophytes from two forest areas of the municipality of Campo Mour?o, PR, Brazil. The vegetation of the municipality is characterized mainly by an ecotone between the Seasonal Semideciduous Forest and Mixed Ombrophilous Forest. We recorded 56 species, distributed in 31 genera and 16 families. The most representative families were Pteridaceae (14) and Polypodiaceae (11) and the wealthier genre was Thelypteris (6). The terricolous species were predominant (72%) and the preferential environments were riparian vegetation and forest interior (70%). The flora of Campo Mour?o was more similar to the studies conducted in the state of Rio Grande do Sul, and the cophenetic correlation coefficient (r = 0.9058) showed a consistent adjust. In the principal components analysis (PCA) the variance explained by the two principal components was 72.99%. The wealth found in this study corresponds to approximately 11.4% of the flora of ferns and lycophytes of Paraná. Future contributions are needed to increase the knowledge about the flora of ferns and lycophytes in areas of ecotone, mainly in the region of Campo Mour?o, where the studies are scarce.
文摘Techniques of production of enthomopatogenic bacteria are developed aiming to increase the productivity and to reduce the costs of the fermentative process. Like this, it has been using agroindustrial wastes or by-products as nutrient sources in culture medium, having been used, in this study, the manipueira, a by-product of the processing of the cassava flour. Fermentations were performed in flasks of Erlenmeyer of 500 mL containing 250 mL of culture media, conditioned in shaker at 180 r.p.m. and 28°C, and the media were composed by manipueira, in concentrations that varied between 400 and 1000 mL/L. The time of the process varied between 48 and 120 hours. They appraised the following parameters: cellular growth, the production of spores, the reduction of organic matter (COD analysis) and the variation of reduction sugar. Although there was a proportional cellular growth to the manipueira concentration, the production of spores was similar in all the cases, at the end of the process, in spite of the smallest speed of production of the same ones in the highest concentrations. In relation to the variation of COD, it has, also, a percentile minor of reduction in the highest concentrations. In the analysis of variation of reduction sugars, the higher concentrations are the ones that they present larger slowness in the reduction of this.
文摘This article presents a study on the structural behavior of transversely prestressed laminated timber slabs,focusing on an innovative approach:vertically misaligned lamellae.This 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 stiffness.Testing 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 control.Failures 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 peak.Despite a higher number of failed lamellae,the study group demonstrated promising performance.Analysis of prestressing bar indicated no damage at all in the thread,suggesting potential for reducing bar diameter.These findings offer crucial insights into applying these slabs in timber construction as well as to any kind of construction.
文摘Nonlinear system identification concerns the determination of the model structure and its parameters.Although the designers often seek the best model for each system,it can be tricky to determine,at the same time,the best structure and the parameters which optimize the model performance.This paper proposes the use of a Genetic Algorithm,GA,and the Levenberg-Marquardt,LM,method to obtain the model parameters,as well as perform the order reduction of the model.In order to validate the proposed methodology,the identification of a magnetic levitator,operating in closed loop,was performed.The class NARX-OBF,Nonlinear Auto Regressive with eXogenous input-Orthonormal Basis Function,was used.The use of OBF functions aims to reduce the number of terms in NARX models.Once the model is found,the order reduction is performed using GA and LM,in a hybrid application,capable of determining the model parameters and reducing the original model order,simultaneously.The results show,considering the inherent trade-of between accuracy and computational effort,the proposed methodology provided an implementation with good mean square error,when compared with the full NARX-OBF model.
文摘This paper presents a new programming paradigm named Notification Oriented Paradigm (NOP) and analyses performance aspects of NOP programs by means of an experiment. NOP provides a new manner to conceive, structure, and execute software, which allows better performance, causal-knowledge organization, and entity decoupling than standard solutions based upon current paradigms. These paradigms are essentially Imperative Paradigm (IP) and Declarative Paradigm (DP). In short, DP solutions are considered easier to use than IP solutions thanks to the concept of high-level programming. However, they are considered slower to execute and lesser flexible to program than IP. Anyway, both paradigms present similar drawbacks like causal-evaluation redundancies and strongly coupled entities, which decrease software performance and processing distribution feasibility. These problems exist due to an orientation to monolithic inference mechanism based upon sequential evaluation by means of searches over passive computational entities. NOP proposes another manner to structure software and make its inferences, which is based upon small, smart, and decoupled collaborative entities whose interaction happen by means of precise notifications. This paper discusses NOP as a paradigm and presents certain comparison of NOP against IP. Actually, performance is evaluated by means of IP and NOP programs with respect to a same application, which allow demonstrating NOP superiority.
