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Piezomagnetic vibration energy harvester with an amplifier

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Theoretical & Applied Mechanics Letters 2023年第6期13卷 481-483页

作者： joão Pedro Norenberg Americo Cunha jr.Piotr Wolszczak Grzegorz Litak Department of Mechanical Engineering São Paulo State UniversityIlha SolteiraSPBrazil Department of Applied Mathematics Rio de Janeiro State UniversityRio de JaneiroRJBrazil Department of Automation Lublin University of TechnologyLublinPoland

We study the effect of an amplification mechanism in a nonlinear vibration energy harvesting system where a ferromagnetic beam resonator is attached to the vibration source through an additional linear spring with a *** beam moves in the nonlinear double-well potential caused by interaction with two *** piezoelectric patches with electrodes attached to the electrical circuit support mechanical energy transduction into electrical *** results show that the additional spring can improve energy *** changing its stiffness,we observed various *** the point of the optimal stiffness of the additional spring,the power output is amplified a few times depending on the excitation amplitude.

关键词： Nonlinear energy harvesting Piezoelectric Displacement amplifier bistable potential

Generalized Jackiw-Teitelboim gravity in presence of block brane-like models

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Chinese Physics C 2022年第12期46卷 258-270页

作者： I.Andrade D.bazeia A.S.Lobão jr. R.Menezes Departamento de Física Universidade Federal da Paraíba58051-970 João PessoaPBBrazil Escola Técnica de Saúde de Cajazeiras Universidade Federal de Campina Grande58900-000 CajazeirasPBBrazil Departamento de Ciências Exatas Universidade Federal da Paraíba58297-000 Rio TintoPBBrazil

We investigate generalized Jackiw-Teitelboim gravity,coupling the dilaton field with two scalar matter *** obtain the equations of motion for the fields and investigate a linear perturbation of the solutions in *** study two specific situations that allow for analytic solutions with topological behavior and check how the dilaton field,the warp factor and the Ricci scalar *** particular,we show how the parameters can be used to modify the structure of the ***,the perturbations are,in general,described by intricate coupled differential equations,but in some specific cases,we can construct the corresponding zero modes analytically.

关键词： Dilaton 2D gravity Multifield

buzz-pollination in Neotropical bees:genus-dependent frequencies and lack of optimal frequency for pollen release

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Insect Science 2020年第1期27卷 133-142页

作者： Conrado Augusto Rosi-Denadai Priscila Cassia Souza Araujo Lucio Antonio de oliveira Campos Lirio Cosme jr. Raul Narciso Carvalho Guedes Departamento de Entomologia Universidade Federal de VigosaVigosaMinas GeraisBrazil Departamento de biologia Geral Universidade Federal de VigosaVigosaMinas GeraisBrazil

over 50 genera of bees release pollen from flower anthers using thoracic vibrations,a phenomenon known as *** efficiency of this process is directly affected by the mechanical properties of the buzzes,namely the duration,amplitude,and ***,although the effects of the former two properties are well described,the role of buzz frequency on pollen release remains ***,nearly all of the existing studies describing vibrational properties of natural buzz-pollination are limited to bumblebees(bombus)and carpenter bees(Xvlocopa)constraining our current understanding of this behavior and its ***,we attempted to minimize this shortcoming by testing whether flower anthers exhibit optimal frequency for pollen release and whether bees tune their buzzes to match these(optimal)*** true,certain frequencies will trigger more pollen release and lighter bees will reach buzz frequencies closer to this optimum to compensate their smaller buzz *** strategies were used to test these hypotheses:(i)the use of(artificial)vibrational playbacks in a broad range of buzz frequencies and amplitudes to assess pollen release by tomato plants(Solarium Ivcopersicum L.)and(ii)the recording of natural buzzes of Neotropical bees visiting tomato plants during *** playback experiment indicates that although buzz frequency does affect pollen release,no optimal frequency exists for *** addition,the recorded results of natural buzz-pollination reveal that buzz frequencies vary with bee genera and are not correlated with body ***,neither bees nor plants are tuned to optimal pollen release *** frequency of buzz-pollination is a likely consequence of the insect flight machinery adapted to reach higher accelerations,while flower plant response to buzz-pollination is the likely result of its pollen granular properties.

关键词： buzz amplitude buzz frequency floral sonication pollination stingless bees vibration

Treating Insomnia in older Adult Patients: Limiting benzodiazepine Use

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Pharmacology & Pharmacy 2019年第3期10卷 116-129页

作者： joseph V. Pergolizzi jr. Robert Taylor jr. jo Ann LeQuang Errol Gould Robert b. Raffa NEMA Research Inc. Naples FL USA Neumentum Palo Alto CA USA LeQ Medical Angleton TX USA Pernix Therapeutics Morristown NJ USA University of Arizona College of Pharmacy Tucson AZ USA Temple University School of Pharmacy Philadelphia PA USA

As aging comes, an increased prevalence of medical maladies and chronic pain independently or interactively disrupt sleep, which in turn can exacerbate either one. Furthermore, anxiety about pain can further negatively impact sleep. Fortunately, good quality sleep can improve pain management. because benzodiazepine receptor agonists (including the “Z” drugs) can reduce anxiety and improve sleep, they seem a convenient choice. However, their use in this population, particularly for more than short-term (guidelines range from 2 to 6 weeks max), is not recommended because of increased likelihood of falls, further disruption of sleep, dependence, and problems with discontinuation (withdrawal). besides, this population is often likely to take concomitant medication for pain or other central nervous system depressants leading to potentially serious and even life-threatening interactions involving synergistic amplification of respiratory depression (opioids being a particularly dangerous interaction). Therefore, insomnia in older adults should ideally be treated with a non-benzodiazepine receptor agonist;if indicated, they may be used, but should be closely monitored and tapered to avoid long-term adverse problems (direct or from withdrawal). older adult patients with insomnia may be more optimally treated with sleep aids that do not interact with the GAbAA receptor.

关键词： Pain Insomnia older Adults benzodiazepines “Z”-Drugs GAbAA Receptor

New Approach to the Strain Analysis of bragg Grating Sensors

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Photonic Sensors 2013年第1期3卷 74-80页

作者： josé R. Alves da CUNHA Petrus Alcantara jr. Angela Santa bRJGIDA Gilvan boRGES joāo Weyl CoSTA Programa de Pós-Graduacāo em Fisica Universidade Federal do Pará Belém 66075-11 O Brazil Programa de Pós Graduacāo em Engenharia Elétrica Universidade Federal do Pará Belém 66075-11 O Brazil

The response of an optical strain sensor based on the fiber bragg grating is theoretically analyzed with a different approach of that found usually in the literature. In this model, geometrical changes suffered by the grating itself are taken into account. The results are compared with those from experiments, showing very good agreement.

关键词： bragg grating sensor strain sensor bragg wavelength

Hormone Replacement Therapy for Restoring the HPG Axis in Pain Patients Treated with Long-Term opioid Analgesics

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Pharmacology & Pharmacy 2018年第11期9卷 473-480页

作者： Srinivas Nalamachu joseph V. Pergolizzi jr. Robert Taylor jr. jo Ann Le Quang joseph V. Pergolizzi III Robert b. Raffa International Clinical Research Institute and Pain Management Institute Overland Park KS USA NEMA Research Inc. Naples FL USA LeQ Medical Angleton TX USA College of Pharmacy University of Arizona Tucson AZ USA School of Pharmacy Temple University Philadelphia PA USA

opioids are a treatment option for a variety of chronic pain conditions. but long-term opioid use can be associated with side effects, including hypogonadism. opioid-induced hypogonadism (oIhG) is associated with the alteration of the hypothalamic-pituitary-gonadal axis (HPG). In males, hypogonadism can result in erectile dysfunction, reduced libido, fatigue, worsening mood, and increased risk of osteoporosis;in females, it can result in changes in the menstrual cycle and reduced libido, among other effects. A current treatment option for these patients is hormone replacement therapy. In this report, we discuss the problem of opioid-induced hypogonadism, and the therapeutic approach and the potential complications of treating pain patients using hormone replacement therapy.

关键词： opioid Therapy Chronic Pain HPG Axis Hormone Replacement Therapy

Neutrino masses,cosmological inflation and dark matter in a variant U(1)b-L model with type II seesaw mechanism

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Chinese Physics C 2021年第2期45卷 621-630页

作者： J.G.Rodrigues A.C.o.Santos J.G.Ferreira jr.C.A.de S.Pires Departamento de Física Universidade Federal da ParaíbaCaixa Postal 500858051-970João PessoaPBBrasil Departamento de Física Universidade Federal do Rio Grande do Norte59078-970NatalRNBrasil

In this study,we implemented the type Ⅱ seesaw mechanism into the framework of the U(l)b-L gauge *** achieve this,we added a scalar triplet,A,to the canonical particle content of the U(l)b-Lgauge *** imposing that the U(l)b-L gauge symmetry be spontaneously broken at TeV scale,we show that the type Ⅱ seesaw mechanism is realized at an intermediate energy scale,more precisely,at approximately 109 *** prevent heavy right-handed neutrinos from disturbing the mechanism,we evoke a Z2 discrete ***,as a result,we have standard neutrinos with mass around eV scale and right-handed neutrinos with mass in TeV scale,with the lightest one fulfilling the condition of dark *** developed all of these in this *** addition,we show that the neutral component of Δ may perform unproblematic non-minimal inflation with loss of unitarity.

关键词： models beyond the standard model particle-theory and field-theory models of the early universe neutrino mass and mixing

Development of a New bio-based Insulating Fluid from <i>Jatropha curcas</i>oil for Power Transformers

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Advances in Chemical Engineering and Science 2017年第2期7卷 235-255页

作者： josé M. G. Evangelista jr. Fabrício E. bortot Coelho Juliana A. o. Carvalho Estê vã o M. R. Araújo Tania L. S. Miranda Adriane Salum Chemical Engineering Department Federal University of Minas Gerais (UFMG) Belo Horizonte Brazil

The present work aims to develop a new vegetable insulating fluid for power transformers based on Jatropha curcas oil. besides its technical benefits, Jatropha curcas oil has a socio-economic role by promoting income to rural families, contributing to the countryside development and avoiding rural exodus. Thus, the entire transformer oil production (extraction, processing, characterization and accelerated aging) was covered and a new process was developed. For oil extraction, the most suitable process was the solvent extraction (5 mL of hexane per gram of crushed non-peeled seeds during 30 minutes) with an oil yield of 32%. In raw oil processing stage, the degumming, with 0.4 g of phosphoric acid per 100 g of oil, at 70°C, was used to remove phosphatides. Then, free fatty acids were 96% neutralized with a sodium hydroxide solution (0.5% w/w) at room temperature. For the oil clarification, the combination of 5% w/woil of activated carbon and 1% w/woil of Mgo resulted in a bright, odorless and clear oil with an acid number of 0.04 mgKoH·g﹣1. The oil drying in a vacuum rotary evaporator, at 70°C, for 2 hours reduced the water content to 177 ppm. The processed oil was characterized following ASTM D6871 methods. This oil presented higher dielectric breakdown voltage (55 kV) than commercial transformer fluids (bIoTEMP?, EnvirotempFR3?, and bivolt?), which increases transformer safety, capacity and lifetime. In addition, the processed oil has a lower viscosity than bIoTEMP? fluid, which can enhance the heat dissipation efficiency in the transformer. Moreover, the processed oil flash and fire points of 310°C and >340°C, respectively, confirm the great security of vegetable insulating fluids. The analyzed properties of the processed oil fulfill all the ASTM D6871, AbNT NbR 15422 and IEC 62770 specifications. Therefore, Jatropha curcas oil is a potential substitute formineral insulating fluids.

关键词： Vegetable Insulating oil Jatropha curcas Transformer oil biodegradable oil Renewable Material Dielectric breakdown

3D printed millireactors for process intensification

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Chinese journal of Chemical Engineering 2020年第1期28卷 180-190页

作者： Harrson S.Santana Alan C.Rodrigues Mariana G.M.Lopes Felipe N.Russo joao L.Silva jr.osvaldir P.Taranto School of Chemical Engineering University of CampinasBrazil Federal Institute of Education Science and Technology of South of Minas GeraisBrazil

The scope of the present research aims at demonstrating the 3D printing use in the manufacturing of microchannels for chemical process applications. A comparison among digital model processing applications for 3D print(slicers) and a print layer thickness analysis were performed. The 3D print fidelity was verified in several devices, including the microchannels’ printing with and without micromixer zones. In order to highlight the 3D print potential in Chemical Engineering, the biodiesel synthesis was also carried out in a millireactor manufactured by 3D printing. The millireactor operated under laminar flow regime with a total flow rate of 75.25 ml·min^-1(increment of about 130 times over traditional microdevices used for biodiesel production).The printed millireactor provided a maximum yield of Ethyl Esters of 73.51% at 40 ℃, ethanol:oil molar ratio of7 and catalyst concentration of 1.25 wt% and residence time about 10 s. As a result of flow rate increment attained in the millireactor, the number of required units for scaling-up the chemical processes is reduced. Using the approach described in the present research, anyone could produce their own millireactor for chemical process in a simple way with the aid of a 3D printer.

关键词： Process intensification 3D printer Millireactors Micromixers Microdevices biodiesel