bluuebunny/crossref_metadata_2025 huggingface dataset:
Coupled Electromagnetic and Lattice Structure Optimization for the Rotor and Stator of Large Electric Machines
Authors: Hayes Austin C. , Whiting Gregory L.
Published: August 2021

Permanent magnet direct drive (PMDD) electric machines are advantageous due to higher efficiencies and lower maintenance concerns. For wind turbine generators, especially offshore turbines, this is advantageous to geared machines and is currently implemented by manufacturers such as GE, Siemens and Enercon. By nature, a direct drive machine must be larger than its geared counterpart in order to output the same power. As a result, the structural mass is larger and makes the machine prohibitively large. However, the structural mass and electromagnetic design is coupled and the electromagnetic criteria are an important consideration in the structural design. In this analysis, the electromagnetic design of a 5 MW PMDD generator was coupled to a triply periodic minimal surface (TPMS) lattice generator through means of an evolutionary algorithm. Finite element analysis (FEA) was used to determine the radial, torsional, and axial deformations under simulated wind turbine generator loading conditions subject to critical deflection criteria. Lattice functional grading was completed with the FEA deflection data in order to further optimize the structural mass. For the 5 MW test case, functional graded TPMS support structures maintained stiffness for a generator with a 32% higher force density with inactive mass 4% lower than baseline. This study suggests functional grading of TPMS lattice structures for wind turbine generators has the potential at significant mass savings.
Performance Optimization of Thermal Energy Storage Based Solar Collector
Authors: Pawar Vivek R. , Sobhansarbandi Sarvenaz
Published: August 2021

The application of solar collectors in water heating systems has attracted attention in recent years, however, due to the inconsistency of solar radiation, performance of such systems will fluctuate over time. In this study, performance optimization of a heat pipe evacuated tube solar collector integrated with phase change materials (PCMs), is investigated under normal and on-demand operations. In phase-I, the effect of heat pipe position and in phase-II, the effect of various PCMs are investigated. The results from phase-I show phase change process of PCM was expedited by 48 minutes under on-demand operation compared with conventional system. Additionally, in normal operation, thermal storage enhancement is achieved by 24% increase in PCM’s melting fraction. In Phase-II, the selected PCMs are tritriacontane paraffin, xylitol, and erythritol. In normal mode, the paraffin tube exhibited highest total energy storage of 295.39 kJ/kg, however, the fin temperature of xylitol tube was around 10° C higher compared with the other tubes throughout the day. In on-demand operation, erythritol tube shows energy storage of 413.15 kJ/kg, however, the paraffin tube shows fin temperature difference of 14°C compared with other tubes. Consequently, utilization of paraffin/xylitol in normal and paraffin/erythritol in on-demand operation is recommended to enhance system’s thermal performance.
Through-Building Ducts for Mounting Wind Turbines: A Numerical Study
Authors: Mirian Hadi , Anbarsooz Morteza , Hoshyar Abbas , ArabGolarcheh Alireza
Published: August 2021

Yet, several locations for mounting the wind turbines in urban areas have been proposed, which can be categorized into four main groups; (a) on the rooftops, (b) between the buildings, (c) integrated into the buildings’ skin and (d) inside a though-building hole. Through-building holes take advantage of the pressure difference between the windward and leeward facades of the building to generate a high-speed velocity zone for mounting the wind turbine. In the current study, three-dimensional numerical simulations of atmospheric turbulent boundary layer flow around high-rise buildings are carried out to determine the optimum location and size of the duct. For this purpose, square cross-section buildings (20 × 20 m) with heights of H0 = 60, 120 and 180 m are considered. Numerical results showed that the difference of the pressure coefficient on the windward and leeward facades of the building without the hole can predict the best location for mounting the wind turbine with acceptable accuracy. Then, circular holes with various diameters of D = 2.5, 5.0, 7.5, 10 and 12.5m are created at z/H0 = 0.8, where the maximum pressure difference is close to the maximum. It is found that the maximum velocity increment occurs for D = 10 m and it is 31% greater than the U10 velocity of the incident wind profile. This means that the available wind power inside the duct is 2.25 times greater than the incident wind power.
Experimental Investigation of a Novel Combined Rapid Compression-Ignition Combustion and Solid Oxide Fuel Cell System Format Operating on Diesel
Authors: Ahn Andrew , Stone Welles Thomas , Akih-Kumgeh Benjamin , Milcarek Ryan J.
Published: August 2021

Climate change concerns have forced the automotive industry to develop more efficient powertrain technologies, including the potential for fuel cell systems. Solid oxide fuel cells (SOFCs) demonstrate exceptional fuel flexibility and can operate on conventional, widely available hydrocarbon fuels with limited requirements for fuel reformation. Current hybrid powertrains combining fuel cell systems with internal combustion engines (ICEs) fail to mitigate the disadvantages of requiring fuel reformation by placing the engine downstream of the fuel cell system. This work, thus investigates the upstream placement of the engine, eliminating the need for fuel processing catalysts and the heating of complex fuel reformers. The ICE burns a fuel-rich mixture through rapid compression ignition, performing partial oxidation fuel reformation. To test the feasibility of a fuel cell system operating on such ICE exhaust, chemical kinetic model simulations were performed, creating model exhaust containing ∼43.0% syngas. A micro-tubular SOFC (μT-SOFC) was tested for power output with this exhaust, and generated ∼730 mW/cm2 (∼86% of its maximum output obtained with pure hydrogen fuel). Combustion testing was subsequently performed in a test chamber, and despite insufficient equipment limiting the maximum pressure of the combustion chamber, began to validate the model. The exhaust from these tests contained all of the predicted chemical species and, on average, ∼21.8% syngas, but would have resembled the model more closely given higher pressures. This work examines the viability of a novel combined ICE and fuel cell hybrid system, displaying potential for a more cost-effective/efficient solution than current fuel cell systems.
Influence of Some Emulsifiers in Improving the Biofuel Characteristics
Authors: Radulescu Victorita
Published: August 2021

Molecules’ characteristics of the active surface, such as low molecular weight fatty acids, asphaltene, and naphthenic acids determine the properties of emulsified fuels. They can interact with surfaces from other oils, water from liquid mixtures, solid surfaces from mechanical systems, or with pipes walls in case of long distances transport. For heavy oils which contain large amounts of asphaltene, these effects are very important. The characteristics of the emulsified fuels are determined mainly by the properties and nature of the emulsifier. In the present paper, some tests for heavy fuels emulsification with monoglycerides and cosurfactants are mentioned, due to their significant contributions in clean fuels combustion. This first proposed solution, presented in this paper is generally preferred, due to its small cost. The second tested solution consists in nonionic polymer obtained from the solid wastes of PET (polyethylene terephthalate) conversion and glycol. The main advantages of this raw material are the PET’s low cost and its large availability. The PET has high content of oxygen so the combustion of emulsified fuels with this type of surfactants assures low pollution emission. The preparation of the nonionic polymer associated with the glycerol recovery as additives for emulsified fuels is also mentioned. As the first stage, the PET transesterification with glycol at 200°C–210°C with ethylene glycol elimination was mentioned. For experiments, ten samples of emulsified fuels with different emulsifying agents were prepared, being tested their influence on fuel characteristics. Some physical properties of the emulsified fuel as the density at 20°C, viscosity at 90°C, flash point, and the freezing points were also determined. If the emulsifier proportion or the water quantity increase in the emulsified fuel the flash point increases also. Other experiments were realized referring to the freezing point and viscosity’s dependence with temperature. Finally, are presented some remarks concerning the proper report between emulsifier and final fuel properties.
New Solution With Syntheses Inhibitors for the Chemical Cleaning of Organic Pollutants From the Water Supply System Of Generators
Authors: Radulescu Victorita
Published: August 2021

In thermal power plants, during the boilers functioning, heterogeneous deposits of substances must often be removed in order to prolong their operation and avoid their deterioration. The nature, type and quantity of deposits depend on the characteristics of the water supply systems and the chemical operating regime. For boilers with high deposits of copper and iron, the utilization of mineral acids for chemical cleaning is not quite effective, because their surfaces may be covered with a metal copper film. Organic impurities in the water supply affect the operation of steam generators, increasing electrical conductivity and lowering the pH. The heterogeneous composition of the deposits is unevenly distributed in the combustion system, making its cleaning a complex problem. For efficient chemical cleaning, the agents must have a minimal corrosive action on the metal surfaces, ensuring only the dissolution of the compounds on the surface of the boilers. To prevent corrosion of metals, inhibitors are introduced to diminish the reactions on the metal surface or at least to delay the kinetics of the reaction. This paper analyzes the implications of organic pollutants in the corrosion phenomena and chemical processes where they are involved. As an example, the power plant Borzesti affiliated to the Petrochemical Platform, Bacau County, Romania is presented. The adopted solution uses as an inhibitor, a synthesis between amino alcohol and a thiazole, in the presence of water. This inhibitor has been tested in the laboratory on different steels used in energy pipes, in different areas of the thermal circuits in the boiler, as pure steel or with different alloys. The methods used to reduce the effects of corrosion are briefly presented. Four classes of organic substances with properties of corrosion inhibitors in the organic acid environment were analyzed. The experimental results obtained, associated with a comparative analysis of corrosion rates, for different concentrations of inhibitors for a time interval of 4 hours are mentioned. In the second stage, the inhibitor behavior was analyzed for 6h and 8h. Corrosion rates are estimated by measuring the weight loss of the tested probes. Finally, the most suitable types of inhibitors, adapted at different metal compositions are presented, with a result in the cleaning of more than 98% of the surface of the boilers.
Modelling and Performance Analysis of Stationary Gas Turbines Operating Under Rotational Speed Transients
Authors: Andade André L. S. , Venturini Osvaldo J. , Cobas Vladimir R. M. , Silva Vinicius Zimmerman
Published: August 2021

In order to increase the flexibility and performance of gas turbines, generally their manufacturers and research centers involved in their development are constantly seeking the expansion of their operational envelope as well as their efficiency, making the engine more dynamic, less polluting and able to respond promptly to variations in load demands. An important aspect that should be considered when analyzing these prime movers is the assessment of its behavior under transients due to load changes, which can be accomplished through the development of a detailed, accurate and effective computational model. Considering this scenario, the present work aims to develop a model for the simulation and analysis of the dynamic behavior of stationary gas turbines. The engine considered in this analysis has a nominal capacity of 30.7 MW (ISO conditions) and is composed by a two-spool gas generator and a free power turbine. The model was developed using T-MATS, an integrated Simulink/Matlab toolbox, develop by NASA. The gas turbine was evaluated under both permanent and transient regimes and each one of its component was analyzed individually. The assessment made it possible to determine the engine performance parameters such as efficiency, heat rate and specific fuel consumption and its operational limits (surge limits, stall, turbine inlet temperatures, etc.) under different load conditions and regimes. The results obtained were compared with available field data, and the relative deviations for the considered parameters were all lower than 1%.
A Comparison of Different Fluid-Structure Interaction Analysis Techniques for the Marine Propeller
Authors: Rehman Wajiha , Paboeuf Stephane , Tomy Joseph Praful
Published: August 2021

The performance of the propeller is crucial to determine the energy-efficiency of a vessel. Fluid-Structure Interactions (FSI) analysis is one of the widely used methods to determine the hydrodynamic performance of marine propellers. This article is about the validation of a design assessment tool known as ComPropApp which is developed by Cooperative Research Ships (CRS) partners. ComPropApp is a specially designed tool for the FSI analysis of isotropic and composite marine propellers by doing explicit two-way coupling of the BEM-FEM solvers. The Boundary Element Method (BEM) solver of ComPropApp gives it an edge over Reynolds Averaged Navier Stokes Equations (RANSE) solvers in terms of computation time and cost. Hence, it is suitable for the initial design stage. The propeller used in this study is developed under the French Research Project; FabHeli.

The validation is done by performing different types of FSI analysis through commercial RANSE solver (STAR-CCM+) and FEM solver (FEMAP) for only one inflow velocity of the open water case which is 10.3 m/s. The fluid solver of ComPropApp (PROCAL) is a Boundary Element Method (BEM) solver that is based on the potential flow theory while the structural solver (TRIDENT) is a FEM solver. The study is divided into four different cases; BEM-FEM one-way coupled FSI analysis, RANSE-FEM one-way coupled FSI analysis, BEM-FEM explicit two-way coupled FSI analysis with ComPropApp and RANSE-FEM implicit two-way coupled FSI analysis with STAR-CCM+. The calculated values of stresses, displacement, and forces from all the methods are compared and the conclusion is drawn.
Energy Saving Assessment of Triple-Hybrid Vapor Absorption Building Cooling System Under Hot-Dry Climate
Authors: Singh Gaurav , Das Ranjan
Published: August 2021

Thermally driven vapor absorption-based air-conditioning systems possess many advantages over the compression based systems. However, intermittent availability of input resources affects the operation of these absorption systems which causes discontinuous working. This study aims at examining the electrical and thermodynamic performance of a triple-hybrid vapor absorption-assisted air-conditioning system against a conventional system with the aid of EnergyPlus simulations for a small office building. The outside weather is subjected to hot-dry climatic condition. The heat input source includes biomass and solar energy-based resources. Auxiliary heat input is also used to ensure smooth operation. The performance of the absorption system is assessed at different generator temperature (70 °C–80 °C) and solar collector area (400 m2–500 m2). The results show that, by using absorption-based systems, a maximum of 34.1% electrical energy savings can be ensured at 500 m2 collector area with 70 °C generator temperature. The coefficient of performance of the absorption system escalates from 0.50 to 0.52 by increasing the generator temperature form 70 °C to 80 °C. Under the condition of 70 °C generator temperature and 500 m2 collector area, the absorption system can be made fully renewable energy dependent.
Optimizing Water Harvesting on Bioinspired Surfaces: A Mesoscopic Perspective
Authors: Chakraborty Souparna , Chaudhuri Abhirup , Bakli Chirodeep
Published: August 2021

The water crisis affects the lives of millions over the world. Minimizing water losses in major water-consuming industries like power plants is of utmost importance. Since cooling towers lead to huge amounts of water loss, implementing modifications for recovering a fraction of this lost water in the exhaust has been a topic of active research. These modifications are often inspired by biological species, especially in arid regions, which have adapted in different ways by collecting water from fog, and hence biomimetic has become popular for water harvesting techniques. We revisit the fog collection technique most commonly used in nature and compare the relative merits of the same with surface texture and wettability. Arrays of spines of three different configurations were considered in this study — namely cuboidal, cylindrical and conical shapes. A theoretical model is developed to carry out a comparative analysis of these configurations considered. The effects of Laplace pressure gradient, gravity, topography and tilt angle on droplet transportation along the spines were explored to decipher the most efficient water transport and collection route. The observations are explained by performing extensive Molecular Dynamics (MD) simulations to bring out the interplay of surface tension and roughness at the contact line verifying the proposed formulations. The conical-shaped spines exhibited maximum transport and collection efficiency for zero tilt angle. Both cuboidal and cylindrical shaped spines showed little or no water collection when the spines are oriented horizontally. This is due to the Laplace pressure gradient which arises from varying radii of curvature of the conical shaped spine which drives the water droplets towards the base but is absent for the other two cases considered. On the contrary, when there is some finite tilt angle, the contribution of gravity comes into consideration and the water collection rate of the conical and cylindrical spines becomes comparable. Both Laplace pressure gradient and gravity help in water transport in the conical case whereas only gravity assists the water transport process for cylindrical spines. Still, the water collection rate is almost the same for these two scenarios due to enhanced coalescence of liquid droplets for the cylindrical case as is observed from MD simulations. As the droplets coalesce, they get larger and gravity aids the transport process by overcoming the solid-liquid interaction strength. Cuboidal shaped spines show the least efficiency with only gravity to assist the transport process and no coalescence is observed in this case. Moreover, the geometrical disparity makes the tips of conical spines more hydrophobic compared to the others which further ameliorates the water collection efficiency.
Control of Wave Energy Converter With Losses in Electrical Power Take-Off System
Authors: Zhou Xiang , Zou Shangyan , Weaver Wayne W. , Abdelkhalik Ossama
Published: August 2021

A permanent magnet linear electrical machine power takeoff (PTO) unit is simulated on the direct drive wave energy converter in this paper, which is controlled to provide the required reactive power. A shape-based control is implemented to maximize the wave energy production (mechanical PTO) with the limiting constraints on the electric drive. Further, the linear electrical machine design is optimized such that the electrical power output is maximized (e.g., reduced power losses). The numerical simulations are conducted using MATLAB/Simulink and the Simscape toolbox. Linear wave theory is applied in modeling the buoy dynamics. Additionally, the PTO unit is composed of a linear electrical machine, an ideal inverter, and an ideal energy storage system. The results show the proposed PTO tracks the reference control accurately. The electrical power output is significantly improved by limiting the current in the PTO compared to a passive control.
Investigation of Air Extraction and Carbon Capture in an Integrated Gasification Combined Cycle (IGCC) System
Authors: Acharya Shisir , Wang Ting
Published: August 2021

Coal is one of the major sources of energy currently as it provides up to 38.5% of the total electricity produced in the world. Burning coal produces pollutants and large amounts of CO2, which contribute to climate change, environmental pollution, and health hazards. Therefore, it is our obligation to utilize coal in a cleaner way. Cleaner coal energy can be produced by using an ultra-supercritical Pulverized Coal (PC) power plant, or by employing the Integrated Gasification Combined Cycle (IGCC). Since the 1970s, the IGCC technology has been developed and demonstrated, but it has still not been widely commercialized. One of the methods to improve IGCC performance is to save the compression power of the air separation unit (ASU) by extracting the compressed air from the exit of the gas turbine as a portion of or the entire air input to the ASU. This paper investigates the effect of various levels of air integration on the IGCC performance. The results show that a moderate air integration ranging from 15% to 20% provides the most effective air-integration. An analysis of implementing a sour-shift pre-combustion carbon capture results in a significant loss of about 5.5 points in efficiency. This study also provides the effect of air integration and carbon capture on emissions including NOx, SOx, CO2, and water consumption.
Investigation of Phase Change Material Integrated With High Thermal Conductive Carbon Foam Inside Heat Sinks for Thermal Management of Electronic Components
Authors: Kumar Anuj , Kothari Rohit , Sahu Santosh K. , Kundalwal Shailesh I. , Sharma Akhalesh
Published: August 2021

In recent years phase change materials (PCMs) have emerged as a promising material for various thermal management applications. However, the lower thermal conductivity of PCM is a major hindrance in its widespread use. In the present study, an experimental investigation is carried out using high thermal conductive carbon foam (CF) embedded with PCM inside heat sink for thermal management of electronic components. Various configurations of heat sinks such as unfinned heat sink without PCM, unfinned heat sink integrated with PCM, unfinned heat sink integrated with CF-PCM composite, two finned heat sink integrated with PCM, and two finned heat sink integrated with CF-PCM composite are investigated. The vacuum impregnation technique is employed to infiltrate the PCM inside the CF. Heat flux is varied in the range of 1.5 to 2.5 kW/m2. Temperature variation of the heat sink base is used to compare the performance of various heat sinks. Unfinned heat sink without and with PCM is used for baseline comparison. Enhancement ratios are presented for various set point temperatures (SPT) such as 65 and 75°C. The highest enhancement ratio of 4.98 is obtained for two fin CF-PCM composite heat sink.
An Inverse Method for Parameter Retrieval in Solar Thermal Collector With a Single Glass Cover
Authors: Das Ranjan
Published: August 2021

The present article highlights the implementation of differential evolution (DE)-assisted metaheuristic optimizer to provide the solution of an inverse multi-variable problem related to a flat absorber solar collector consisting of a single glass. For satisfying a given heating requirement from the solar collector, the necessary tilt angle and the thickness of the glass cover are simultaneously predicted using the proposed DE methodology. The existing study of inverse multi-variable optimization analysis has been done for dynamic values of solar energy radiation and different ambient conditions commonly encountered in various geographical locations of India. Formulation of the current research involves the minimization of a newly proposed cost function involving the required and the acquired heat transfer rates from the solar collector in Euclidean space. The solution approach then utilizes a dynamic exchange between evolutionary metaheuristic DE and a well-validated forward solver containing analytical expressions of heat energy balance within the solar collector. Variations of cost function and the estimated design variables are mainly studied to visualize the algorithm’s behavior for a single gazing-based solar thermal device. Multiple possible groupings of the unknown parameters of the solar collector are revealed, which always collectively result in a desired heating requirement from the solar collector. Sensitivity indices related to the design variables are evaluated for ascertaining the relative importance of parameter selection. Encouraging opportunity is found towards the system’s size reduction through sparing selection of inclination angle. The current study provides a convenient and cost-effective tool to select the necessary inclination and glass covers to obtain low to medium heating requirements from the available incident solar energy.
Experimental Investigation of Ammonia and Sulfur Deposition Characteristics in Rotary Air Preheater
Authors: Gao Rongze , Sun Haojia , Wang Limin , Bu Yufan , Wang Chao , Che Defu
Published: August 2021

With the application of selective catalytic reduction (SCR) technology, the operation of rotary air preheaters is faced with a challenge, the fouling problem caused by ammonium bisulfate (ABS). In previous studies, within the operational temperature range of the preheater, the gaseous ammonia and sulfur trioxide (or H2SO4) in the flue gas can react to form ABS and ammonium sulfate (AS). The initial condensation temperature of ABS might be over predicted due to the effect of the formation of AS, which has a higher initial formation temperature than ABS. In this study, the effects of the deposition temperature, ammonia-sulfur molar ratio and molar product of inlet flue gas on the deposition characteristics of inducing ash deposition compounds were experimentally studied to provide guidance to prevent fouling and corrosion of rotary air preheaters. The results show that the main path to generate ABS is the reaction between H2SO4 and NH3. With the increase in the deposition temperature, the contents of NH4+ and SO42− in the sediments decrease continuously, and the proportion of AS deposition increases. On the contrary, with temperature decreasing, more ABS is deposited. When the molar ratio of ammo-sulfur in the inlet flue gas increases, the proportion of AS in the sediments increases, and the deposition rate also gradually increases. When the ammo-sulfur product in the inlet flue gas increases, the concentrations of both NH4+ and SO42− in the sediments increased in a nearly consistent trend. The variations of the ratio and deposition rates of the two ions in the sediments were not obvious. The ratio of NH4+ and SO42− remains at about 1.2, and the sediment is mainly ABS.
A Plan for Biomass Power Generation With Negative Carbon Emissions
Authors: Parker Marc A.
Published: August 2021

Worldwide energy consumption is accelerating at an unprecedented rate while humanity comes to understand the effects of climate change. Renewable resources such as wind and solar supply more energy every year, but the overwhelming majority of energy consumed is still from fossil fuels. The transition to zero carbon emission sources is important, but carbon negative energy could also become necessary in ensuring a sustainable global environment and economy. The most technically and commercially viable carbon negative solution is biomass-fueled power generation with carbon capture and sequestration. A conceptual design based on a biomass-fired circulating fluidized-bed boiler and developed using the Thermoflex software package (Thermoflow, Inc.) is presented that can be evaluated and pursued by the research, engineering, and business communities. Recommendations are proposed for siting and fuel supply in the Southeastern U.S., with an evaluation of some of the impacts from wood harvesting, processing, and transportation to the lifecycle carbon emissions. An economic analysis of this carbon negative concept indicates that certain policy proposals in the U.S. could make biomass power generation with carbon capture and sequestration an economically feasible resource. Results show that an owner and/or the public could realize a net benefit of up to $332/MWh above and beyond marginal energy or capacity values under aggressive carbon pricing.
Characterizing the Transitional Behavior of Wind Turbine Wake From Near to Far Wake Regimes
Authors: Kumar Ravi , Siram Ojing , Sahoo Niranjan , Saha Ujjwal K.
Published: August 2021

Knowledge of wind energy harvesting is an ever-growing process, and to meet the enormous energy demand, wind farms shall have a significant role. An efficient wind farm is required to have an in-depth knowledge of turbine wake characteristics. This article presents an experimental investigation of the wake expansion process defined by the transition of wake from near to far wake regimes. The study has been performed on models horizontal axis wind turbine (HAWT) composed of NACA 0012 profile, keeping the ratio of root chord to tip chord length is 5:2. A constant temperature hot-wire anemometer (HWA) has been used to examine the rotor’s fluctuating flow field. The subsequent time-averaged normalizes velocity deficit, and vortex shedding frequency are used for the flow characteristics. Time-averaged velocity deficit measurement suggests a drop in upstream velocity by 20–30% within the vicinity of rotor tip downstream of the rotor plane. The study shows that flow recovery is initiating from the near wake regime around 1.08R. Further, the spectral findings indicates the low frequency dominance within 4R (R being the rotor radius), and the Strouhal number falls close to 0.23. The present wind tunnel study on wake characteristics throws significant insight into further enhancing the WT wake modeling.
Helen Safa: "Muchos aspectos de la política pública son inconscientemente patriarcales."
Authors:   Universidad Autónoma de Madrid, Gonzálvez Torralbo Herminia , Rodriguez Cuevas Lydia ,   Universidad Autónoma de Madrid
Published: August 2021

Presentamos en este número a la antropóloga Helen Safa, catedrática emérita de la Universidad de Florida y referencia mundial en materias de migración, pobreza, género y desarrollo urbano. Safa es autora de más de una docena de libros y de casi un centenar de artículos. Ha impartido y compartido experiencias en universidades de Europa, Latinoamérica y Estados Unidos desde la década de los cincuenta. Durante un ciclo de conferencias en la Universidad Autónoma de Madrid, quiso compartir con Herminia Gonzálvez y Lydia Rodríguez intensas impresiones de su dilatada experiencia en gran número de países, especialmente latinoamericanos, como Puerto Rico, Cuba, República Dominicana o México.
Fernando García, FLACSO (Ecuador): “En países como los nuestros es muy difícil que los antropólogos seamos indiferentes”
Authors:   Universidad Autónoma de Madrid, Rodriguez Cuevas Lydia
Published: August 2021

Fernando García Serrano es uno de los pioneros de la antropología en Ecuador. Fue uno de los primeros en graduarse en dicha disciplina, desde que la carrera comenzó a impartirse en la Pontificia Universidad Católica de Ecuador en 1972. Realizó su postgrado en la Universidad Iberoamericana de México donde fue alumno del antropólogo español Ángel Palerm. Ha trabajado como docente e investigador en la Universidad Católica, en temas de desarrollo en varias ONGs y en el Fondo Ecuatoriano-Canadiense de Desarrollo. Ha sido consultor de varios organismos internacionales. Actualmente es coordinador del programa de antropología de la Facultad Latinoamericana de Ciencias Sociales sede Ecuador (FLACSO). Sus áreas de interés son los temas étnicos, movimientos sociales, cultura y poder y antropología jurídica. En esta entrevista, nos habla de una gran diversidad de temas de actualidad que desarrollan tanto la antropología académica latinoamericana como la europea: indigenismo, la visión de “El Otro” o el desarrollo, los derechos humanos, la perspectiva de las culturas hegemónicas y el compromiso de nuestra disciplina ante el conflicto cultural.
Ángeles Díaz Ojeda: "En cooperación al desarrollo debería exigirse que la gente tuviera un mínimo de conocimiento de antropología"
Authors:   Universidad Autónoma de Madrid, Rodriguez Cuevas Lydia
Published: August 2021

Ángeles Díaz Ojeda es actualmente Consejera Técnica de la Subdirección General de Cooperación con los Países de América del Sur de la Agencia Española de Cooperación Internacional (AECI). Es responsable del Programa Indígena, que gestiona y coordina la cooperación española con los pueblos indígenas. Ángeles Díaz se licenció en Sociología (especialidad en Antropología) a finales de los 70 y participó activamente en la implantación de los actuales departamentos de antropología y en la creación de la Federación de Asociaciones de Antropología del Estado Español (FAAEE). Además, ha sido conservadora en el Museo Nacional de Antropología (España) y desde principios de los 90 es responsable de la cooperación española con diversos países africanos y latinoamericanos. En esta entrevista Ángeles Díaz nos habla sobre el nacimiento de la FAAEE y sobre la institucionalización de la antropología en España, así como de la relación entre la antropología y la cooperación para el desarrollo.
“Being” an Older Adult Skier: The Phenomenology of Masters Alpine Ski Racers
Authors: Litchfield Carly , Connelly Denise M. , Hay Melissa E. , Kinsella Elizabeth Anne
Published: August 2021

This research examined the lived experience of older adult Alpine skiers in their continued participation in competitive ski racing. The aim was to gain an understanding of the meaning of the experiences for older adults as they continued to compete in Alpine ski racing. Masters skiers between the ages of 69 and 82 years participated in individual interviews. Data collection and analysis were iterative processes informed by phenomenological methods and visual mind mapping. The overarching theme identified in participants’ accounts was the significance of the identity of “Being”a Ski Racer. Supporting subthemes wereEnjoying the Feeling of Ski Racing,Adapting in the Sport, andSkiing as a Lifestyle. These insights offer the opportunity to encourage and support the holistic experiences of older adults who maintain their athletic identity as they age. This research highlights how inclusion of older adults’ stories may foster critical reflexivity and challenge assumptions about aging.
Rate of Torque Development and Torque Steadiness of the Lower Limb and Future Falls Among Community-Dwelling Older Adults Without Previous Falls: A Longitudinal 1-Year Study
Authors: Porto Jaqueline Mello , Freire Júnior Renato Campos , Capato Luana Letícia , Spilla Sállua Berlanga , Nakaishi Ana Paula Midori , Braz e Silva Elisa , Faccio Andrea Fernanda Forestieri , Abreu Daniela Cristina Carvalho de
Published: August 2021

The objective was to investigate the association between rate of torque development (RTD) and torque steadiness (TS) of the lower limb and the occurrence of prospective falls in community-dwelling older adults without falls in the previous year. One hundred older adults performed the tests to obtain the RTD and TS of the hip, knee, and ankle. New episodes of falls were monitored through telephone contact for a prospective period of 12 months. The association of RTD and TS with the occurrence of prospective falls was verified by multiple logistic regression adjusted for confounding variables. There was no association between RTD of hip, knee, and ankle and prospective falls. Only the TS at 50% of the peak torque of the hip flexors was associated with the occurrence of future falls (p = .023). Identifying modifiable risk factors for the first fall in older adults is essential for the development of adequate prevention programs.
Home-Based Exercise for People With Chronic Kidney Disease: A Systematic Review and Meta-Analysis
Authors: Pedroso Renata Valle , Sanchez-Lastra Miguel Adriano , Comesaña Laura Iglesias , Ayán Carlos
Published: August 2021

Background: Exercise performed at home could be a useful therapy for people with chronic kidney disease. This systematic review and meta-analysis aimed at describing the characteristics, main findings, methodological quality, and adherence rate reported in the existent randomized controlled trials that have provided information regarding the impact of home-based exercise programs on people with chronic kidney disease. Methods: Electronic databases (MEDLINE/PubMed, SPORTDiscus, Scopus, and CENTRAL) were searched up to April 2021, using the keywords: “Exercise”; “Home”; “Kidney Disease.” Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement was adopted. Jadad scale and Cochrane’s tool were used to assess the methodological quality and risk of bias. Results: Out of the 14 studies finally selected, 11 were included in the meta-analysis and most presented high methodological quality. The meta-analysis showed significant effects of home-based exercise on fitness and quality of life, but a little impact on renal function. Although exercise performed at home was mostly feasible and safe, adherence was not high and a considerable number of dropouts were observed. Conclusion: Home-based exercise has positive effects on the fitness’ level and on the quality of life on people with chronic kidney disease. Future studies are needed to identify whether exercise performed at home is a better physical therapy option than center-based exercise.
Quantification of fast molecular adhesion by fluorescence footprinting
Authors: Yasunaga Adam B. , Li Isaac T. S.
Published: August 2021

Short DNA duplexes are pulled apart as a sensor to measure the molecular force in fast cell adhesion.
Theta oscillations synchronize human medial prefrontal cortex and amygdala during fear learning
Authors: Chen Si , Tan Zheng , Xia Wenran , Gomes Carlos Alexandre , Zhang Xilei , Zhou Wenjing , Liang Shuli , Axmacher Nikolai , Wang Liang
Published: August 2021

Direct electrophysiological recordings reveal how theta oscillations synchronize human mPFC and amygdala during fear learning.
Immune checkpoint inhibitors increase T cell immunity during SARS-CoV-2 infection
Authors: Yatim Nader , Boussier Jeremy , Tetu Pauline , Smith Nikaïa , Bruel Timothée , Charbit Bruno , Barnabei Laura , Corneau Aurélien , Da Meda Laetitia , Allayous Clara , Baroudjian Barouyr , Jebali Majdi , Herms Florian , Grzelak Ludivine , Staropoli Isabelle , Calmettes Vincent , Hadjadj Jerome , Peyrony Olivier , Cassius Charles , LeGoff Jerome , Kramkimel Nora , Aractingi Selim , Fontes Magnus , Blanc Catherine , Rieux-Laucat Frederic , Schwartz Olivier , Terrier Benjamin , Duffy Darragh , Lebbé Celeste
Published: August 2021

Immune checkpoint inhibitors for melanoma improve adaptive T cell immunity during COVID-19 without exacerbating inflammation.
Magnetomicrometry
Authors: Taylor C. R. , Srinivasan S. S. , Yeon S. H. , O’Donnell M. K. , Roberts T. J. , Herr H. M.
Published: August 2021

We demonstrate real-time in vivo muscle tissue length tracking via implanted magnetic beads.
Organic Hydroperoxide Resistance Gene
ohr
(VPA1681) Confers Protection against Organic Peroxides in the Presence of Alkyl Hydroperoxide Reductase Genes in Vibrio parahaemolyticus
Authors: Chen Ning-Xin , Chu Ying-Jr , Ni Bin , Hsu Paula , Wong Hin-chung
Published: August 2021

Vibrio parahaemolyticus
is the most prevalent foodborne pathogen in Taiwan and some other coastal Asian countries, and its antioxidative activity contributes to the tolerance of this bacterium to different environmental stresses. This study reports on the function of the organic hydroperoxide resistance gene (
ohr
; VPA1681) and its gene regulator
ohrR
(VPA1682) in this pathogen.
Equine Intestinal O-Seroconverting Temperate Coliphage Hf4s: Genomic and Biological Characterization
Authors: Kulikov Eugene E. , Golomidova Alla K. , Efimov Alexandr D. , Belalov Ilya S. , Letarova Maria A. , Zdorovenko Evelina L. , Knirel Yuriy A. , Dmitrenok Andrei S. , Letarov Andrey V.
Published: August 2021

The relationships between virulent and temperate bacteriophages and their impact on high-density symbiotic microbial ecosystems of animals are not always clear and may vary between species or even between individuals. The horse intestinal virome is dominated by virulent phages, and Hf4s is the first temperate equine intestinal coliphage characterized.
Genome Typing and Epidemiology of Human Listeriosis in New Zealand, 1999 to 2018
Authors: Rivas Lucia , Paine Shevaun , Dupont Pierre-Yves , Tiong Audrey , Horn Beverley , Moura Alexandra , Gilpin Brent J.
Published: August 2021

This study describes the epidemiology of listeriosis in New Zealand between 1999 and 2018 as well as the retrospective whole-genome sequencing (WGS) of 453
Listeria monocytogenes
isolates corresponding to 95% of the human cases within this period. The average notified rate of listeriosis was 0.5 cases per 100,000 population, and non-pregnancy-associated cases were more prevalent than pregnancy-associated cases (averages of 19 and 5 cases per annum, respectively).
Aminopeptidase N Is an Entry Co-factor Triggering Porcine Deltacoronavirus Entry via an Endocytotic Pathway
Authors: Yang Yue-Lin , Liu Jianbo , Wang Tong-Yun , Chen Meng , Wang Gang , Yang Yong-Bo , Geng Xin , Sun Ming-Xia , Meng Fandan , Tang Yan-Dong , Feng Li
Published: August 2021

PDCoV is a pathogen with the potential for transmission across diverse species, although the mechanism of such host-switching events (from swine to other species) is poorly understood. Here, we show that PDCoV enters nonsusceptible cells but without efficient replication.
Proteorhodopsin Phototrophy in Antarctic Coastal Waters
Authors: Cifuentes-Anticevic Jerónimo , Alcamán-Arias María E. , Alarcón-Schumacher Tomás , Tamayo-Leiva Javier , Pedrós-Alió Carlos , Farías Laura , Díez Beatriz
Published: August 2021

Proteorhodopsin-bearing microorganisms in the Southern Ocean have been overlooked since their discovery in 2000. The present study identify taxonomy and quantify the relative abundance of proteorhodopsin-bearing bacteria and proteorhodopsin gene transcription in the West Antarctic Peninsula’s coastal waters.
A Unique Dual-Readout High-Throughput Screening Assay To Identify Antifungal Compounds with Aspergillus fumigatus
Authors: Beattie Sarah R. , Krysan Damian J.
Published: August 2021

Fungal infections caused by molds have the highest mortality rates of human fungal infections. These devastating infections are hard to treat and available antifungal drugs are often not effective.
Haploid Genome Analysis Reveals a Tandem Cluster of Four
HSP20
Genes Involved in the High-Temperature Adaptation of
Coriolopsis trogii
Authors: Wang Lining , Liao Baosheng , Gong Lu , Xiao Shuiming , Huang Zhihai
Published: August 2021

Heat stress is one of the most frequently encountered environmental stresses for most mushroom-forming fungi. Currently available fungal genomes are mostly haploid because high heterozygosity hinders diploid genome assembly.
Protocol for a scoping review to evaluate the extent of utilisation of healthcare services by asthma patients in sub-Saharan African countries
Authors: Ndarukwa Pisirai , Chimbari Moses John , Sibanda Elopy
Published: August 2021

Introduction

Health systems in sub-Saharan African (SSA) countries are fragile and centralised. Consequently, majority of people have restricted access to healthcare services. Given the rise in the prevalence and burden of asthma in SSA, it is imperative to scrutinise the utilisation of healthcare services by people with asthma. We aim to understand, through this review, the extent of utilisation of healthcare services by asthma patients in SSA countries.

Methods and analysis

Arksey and O’Malley’s scoping review methodology framework will be used to guide the conduct of this scoping review. We will conduct a search of the literature on the electronic databases: Medline, (using PubMed interface), EMBASE, EBSCOHOST, Web of Science and Google Scholar, grey literature sources and the reference lists of key studies to identify studies appropriate for inclusion. Two reviewers will independently screen all abstracts and full-text studies for inclusion. Registration of the proposed scoping review on the PROSPERO has indicated that no similar work has been or is being done elsewhere. We will review studies published on the subject from January 2009 to May 2020 in SSA.

Ethics and dissemination

The proposed scoping review will contribute towards the knowledge base on utilisation of healthcare services particularly for people with asthma. This will provide a better understanding of the extent of utilisation of healthcare services by asthma patients and ultimately contribute to improvement of quality of care for people suffering from asthma. The results from the review will enlighten and guide healthcare practitioners and researchers on developing appropriate and feasible interventions to increase the utilisation of healthcare services by asthma patients in resource-constrained settings in SSA countries. Results of this scoping review will be disseminated through a peer-reviewed publication, conference presentations and a 1-day stakeholder meeting.

PROSPERO registration number

CRD42020154127.
Prevalence and factors associated with missed hospital appointments: a retrospective review of multiple clinics at Royal Hospital, Sultanate of Oman
Authors: Alawadhi Ahmed , Palin Victoria , van Staa Tjeerd
Published: August 2021

Objectives

Missed hospital appointments pose a major challenge for healthcare systems. There is a lack of information about drivers of missed hospital appointments in non-Western countries and extent of variability between different types of clinics. The aim was to evaluate the rate and predictors of missed hospital appointments and variability in drivers between multiple outpatient clinics.

Setting

Outpatient clinics in the Royal hospital (tertiary referral hospital in Oman) between 2014 and 2018.

Participants

All patients with a scheduled outpatient clinic appointment (N=7 69 118).

Study design

Retrospective cross-sectional analysis.

Primary and secondary outcome measures

A missed appointment was defined as a patient who did not show up for the scheduled hospital appointment without notifying or asking for the appointment to be cancelled or rescheduled. The outcomes were the rate and predictors of missed hospital appointments overall and variations by clinic. Conditional logistic regression compared patients who attended and those who missed their appointment.

Results

The overall rate of missed hospital appointments was 22.3%, which varied between clinics (14.0% for Oncology and 30.3% for Urology). Important predictors were age, sex, service costs, patient’s residence distance from hospital, waiting time and appointment day and season. Substantive variability between clinics in ORs for a missed appointment was present for predictors such as service costs and waiting time. Patients aged 81–90 in the Diabetes and Endocrine clinic had an adjusted OR of 0.53 for missed appointments (95% CI 0.37 to 0.74) while those in Obstetrics and Gynaecology had OR of 1.70 (95% CI 1.11 to 2.59). Adjusted ORs for longer waiting times (>120 days) were 2.22 (95% CI 2.10 to 2.34) in Urology but 1.26 (95% CI 1.18 to 1.36) in Oncology.

Conclusion

Predictors of a missed appointment varied between clinics in their effects. Interventions to reduce the rate of missed appointments should consider these factors and be tailored to clinic.