bluuebunny/crossref_metadata_2025 huggingface dataset:
Vortical characteristics of the corner separation flow in a high-speed compressor cascade
Authors: Wang Bo , Wu Yanhui
Published: May 2022

In aero-engine compressors, corner separations cause blockage, loss generation, and flow instabilities. The aim of the current study is to gain better knowledge of the vortical structures in corner separation flows and their resultant blockage and loss. Numerical simulations at different incidences have been performed for a high-speed linear compressor cascade. First, vortical structures have been visualized with the help of the Q-criterion and eigenvector method, and those associated with the corner separation have been focused on. It was found that the corner separation occurring on either the pressure surface or suction surface corner region was characterized by a large-scale streamwise vortex, named as the corner separation vortex in this paper. The pressure-side corner separation vortex is observed at a great negative incidence initiated from a focus point on the pressure surface, while the suction-side corner separation vortex observed at all concerned incidences originated from a focus on the endwall near the suction surface. Then, the mechanism by which corner separation vortices resulted in blockage and loss has been uncovered. The results showed that low-momentum fluids inside the core region of corner separation vortices led to the flow blockage and the viscous friction between them, and mainstream was responsible for the entropy generation. One major contributor of low-momentum fluids in the suction-side corner region was an off-wall reversed-flow region which was attributed to the breakdown of the suction-side corner separation vortex. Finally, multi-vortex structures in the leading region of the suction-side corner separation at two high positive incidences have been analyzed. It was found that the horseshoe vortex influenced the formation of the suction-side corner separation vortex, which induced a multi-vortex structure, and prevented the onset location of suction-side corner separation vortex from moving upstream with the increased incidence.
Design, analysis, and simulation of a new variable stiffness joint based on antagonist principle
Authors: Contreras-Calderón María Guadalupe , Laribi Med Amine , Arsicault Marc , Castillo-Castañeda Eduardo
Published: May 2022

In robotics, the variable stiffness joints have been developed as an alternative to include flexibility to a rigid mechanism. Variable Stiffness Joint (VSJ) allows for varying the stiffness in a mechanism during the performance of a trajectory. The development of this joint has increased, and various applications have emerged, most to improve human-robot interaction. This paper presents a VSJ based on the principle of antagonistic springs with a set of gears and racks that allow the extension or compression of the springs. The joint provides constant torque or variable torque to obtain a constant or variable force at the output of the link, so a relationship is between the torque provided by the spring’s effort and the output force; however, it is possible to achieve a desired variable force with this joint design. Simulations are realized to obtain the behavior for both a constant and a variable force.
Three dimensional extended finite element simulation of cracked functionally graded pipe and pipe bend
Authors: Sonkar Vaibhav , Bhattacharya Somnath , Sharma Kamal
Published: May 2022

In this work, extended finite element method (XFEM) is used to simulate the fracture mechanics problems of part-through semi-elliptical circumferential crack in functionally graded pipe and pipe bend. Part-through semi-elliptical circumferential crack present in functionally graded pipe and pipe bend at different location has been subjected to internal pressure. Higher order shape function is used to model the crack with level set functions. The inner surface of the functionally graded pipe/pipe bend contains 100% steel alloy and outer surface contains 100% alumina ceramic. The material property gradation is followed by exponential law from inner surface to outer surface of the pipe and pipe bend in radial direction. Domain-based interaction integral approach has been used to determine the stress intensity factor at different location of the crack front.
A precision prediction model for the transmission system of swing angle milling head considering machining and assembly errors
Authors: Su Lihang , Yang Congbin , Zhao Yongsheng , Niu Nana , Chen Kui
Published: May 2022

The performance of the milling head is affected by the machining and assembly process of the parts. The key to improving machining accuracy and reliability of swing angle milling head is to establish the precision prediction model. Therefore, a precision prediction model of swing angle milling head under the influence of multiple errors’ sources is built. The transmission and accumulation of machining and assembly errors along the assembly sequence path for the transmission system are carried out. All essential components on the assembly sequence path are considered. In addition, the secondary impact of the bearing seat hole is also taken into account. The source of the gear assembly errors is explained. The predicted range of transmission error based on the coupling relationship between assembly errors and transmission error is obtained. A precision experiment is carried out, and the result is within the predicted range. This research demonstrates that the errors' coupling relationship considered in this paper does exist and has an effect on transmission error, which provides a new idea for calculating transmission error of other gear systems.
Artificial neural network and numerical analysis for performance enhancement of hybrid microchannel-pillar-jet impingement heat sink using Al2O3-water and CuO-water nanofluids
Authors: Pandey Jyoti , Husain Afzal , Ansari Mohd Zahid
Published: May 2022

This study investigates the effects of nanofluids and its particle volume fractions on performance enhancement of hybrid microchannel-pillar-jet impingement heat sink. The nanofluids used are Al2O3-water and CuO-water. A three-dimensional numerical model is applied to determine the fluid flow and heat transfer performance parameters such as pressure drop, temperature distribution, heat transfer coefficient, pumping power, and thermal resistance. Fluid flow through the jets and channel is assumed to be incompressible steady and laminar for a small range of low Reynolds number (Re ≤ 1000). The results obtained using nanofluid as the working fluid are compared with pure water, which shows that the performance is significantly increased using nanofluids as the heat transfer coefficient is increased and temperature-rise is reduced, however, the pumping power requirement is elevated. Moreover, CuO-water nanofluid provided better thermal management than Al2O3-water, and it is further improved with the increase in particle volume fractions in the base fluid. A trade-off between thermal resistance and pumping power has been obtained and discussed in view of energy consumption and capacity. Empirical correlations and artificial neural network model are developed to predict heat sink performance using water and Al2O3/CuO-water nanofluids as coolant. The model predictions are found within 15% deviation from the numerical data for nanofluids with particle volume fraction from 2-10% and Reynolds number from 100-1000.
Comprehensive analytical framework for optimal sizing of louvered fin flat tube car radiators
Authors: Hadidi Amin
Published: May 2022

In the present research, a comprehensive analytical framework is proposed for optimal sizing of louvered fin flat tube car radiators. In order to perform optimal sizing, eleven geometric variables, which are all geometric parameters of the radiator, were selected as the design parameters. These variables include large and small diameters of tubes, length and wall thickness of tubes, fins’ pitch, louvers’ pitch on each fin, length of the fin, louver length and height, fin thickness, number of fins and louver angle on fins. The effects of all of these parameters on the cooling capacity and total weight of the radiator are investigated in the form of single objective optimization problems in which cooling capacity should be maximized and total weight of the radiator should be minimized. Using the proposed framework, the cooling capacity of the radiator has increased by about 8.8% compared to the base design. It is shown that some geometric parameters have the opposite effect on objective functions. Therefore, an analytical multi-objective optimization procedure is proposed to satisfy both of the goals, simultaneously. The values of the geometric parameters determined in this paper are more practical in terms of manufacturing than the values suggested in the base design.
Determination of abrasion resistance of Fe28Cr5C1Mn coating applied to 30MnB5 boron alloy cultivator blades via electric arc spray
Authors: Güney Bekir , Dilay Yusuf
Published: May 2022

The poor abrasive wear behavior of agricultural machinery affects the farmers all over the world, rendering their activities more inefficient and negatively affecting their productivity. Therefore, innovation in the manufacture of soil cultivation machinery and the selection of wear-resistant materials has been of great importance. Recently, boron alloys, in particular, have been used in the manufacture of machinery parts that work the soil. The aim of this was to investigate the behavior of the blades of the machines widely used in soil cultivation in agricultural production following a surface treatment technique. For this purpose, the blades made of 30MnB5, a material widely used in the production of cultivator blades, were used as substrate samples in the trials as well as blades of the same substrate coated with Fe28Cr5C1Mn alloy wire via the electric arc spray technique. The morphologies and structures of the uncoated and coated samples were comprehensively analyzed by light microscopy, scanning electron microscopy, energy dispersive spectrometry and X-ray diffraction. In addition, their microhardness, porosity, and surface roughness properties were assessed separately before and after plowing. These prepared blades were tested under in the same conditions by plowing the same field at two different soil moisture. Although the weight loss was measured as 9.4 g and 5.4 g in the uncoated and in the coated sample at 9% moisture level, respectively, the weight losses were at 14% humidity level were 10.6 g and 5.9 g in the uncoated and coated samples, respectively. Although the amount of wear increased with increasing humidity levels in both groups, the mass wear loss in cultivator blades coated with Fe25Cr5C1Mn alloy wire was found to be lower in all trials. The results suggest that coating the cultivator blades using electric arc spray would increase agricultural productivity and reduce factors that cause environmental pollution.
Analysis of fluid-solid-thermal coupling characteristics of axial-symmetric vectoring exhaust nozzle
Authors: Yao Si-bo , Luo Zhong , Wei Kai , Sun Yong-Hang , Xu Chun-yang
Published: May 2022

Aiming at the problems of axial-symmetric vectoring exhaust nozzle (AVEN) mechanism due to its complex structure, which leads to the large amount of digital simulation calculation under the coupling of multi-physics, and it is difficult to establish the fluid domain model, a complex AVEN structure is proposed as the research object, the method of AVEN flow field simplify model in cylindrical coordinate system. This method simplifies the contact domain between the expansion regulator plate, the cruciform joint, the convergent regulator plate and the flow field into a cylindrical overall physical model, and constructs a fluid-solid coupling heat transfer physical model. The feasibility of the model is verified. The AVEN fluid-solid-thermal coupling digital simulation calculation is carried out using the sequential one-way coupling method. First, based on computational fluid dynamics, the AVEN fluid-solid coupling heat transfer calculation is carried out to calculate the coupling surface temperature and pressure field. Second, the calculated coupling surface temperature is used as the thermal analysis boundary condition. Then, the temperature field calculated by the thermal analysis and the pressure field calculated by the fluid-solid coupling heat transfer analysis are used as the boundary conditions of the structural strength analysis. Finally, fluid-solid-thermal coupling analysis of AVEN including aerodynamic load and thermal load is carried out. The calculation results show that the digital simulation method proposed in this paper can be used in engineering practice. The temperature and pressure of the AVEN coupling surface show a trend of first decreasing, then increasing, and then decreasing with the change of the position from the throat. Some AVEN mechanical components and parts have stress singular phenomena. The deformation of the AVEN structure is obviously affected by the thermal load, and the minimum change of rate is 9.54%, the maximum change of rate is 1845.37%.
Design of compliant mechanisms with piecewise stiffness variation using self-contact
Authors: Hu Junfeng , Chen Weilong , Niu Jingda
Published: May 2022

Compliant mechanisms with stiffness variation are required in engineering applications. But most studies in the field of compliant mechanisms have only focused on a mechanism with a single stiffness. This paper presents a design method of compliant mechanisms with multi-level stiffness variation using internal self-contact between rigid parts. The contact changes the reconfigurations of compliant mechanisms to vary their stiffness for a specific motion range. We avoid the need for an external control to achieve piecewise stiffness variation. We derived the general design guideline by which the desired multiple stiffness and motion ranges can be acquired through rational design of the structural parameter. To illustrate the effectiveness of the design idea, we fabricated proof-of-concept prototypes for experimental investigations, and the experimental results demonstrated that the designed compliant mechanism has a multiple-motion range corresponding to different stiffness. The design ideas can also be extended to the multi-axis spatial compliant mechanisms. This design idea enriches the theory and application of compliant mechanisms.
Experimental study on electric corrosion damage of bearing and solution
Authors: Huan Jie , Li Songhua , Xia Zhongxian , Wang Yonghua , Wang Weinan , Shi Guangda
Published: May 2022

During the operation of the bearing in the motor, the induced current will inevitably be generated. The bearing raceway will be damaged by current. In this paper, the oil film thickness and capacitance in the bearing are analyzed in detail, and the relationship between oil film thickness, rotational speed, and load is obtained. The oil film thickness increases with the increase of bearing rotation speed and decreases slightly with the increase of load. The minimum oil film thickness of the bearing is between 0.4 μm and 2.9 μm. The capacitance of bearing is influenced by Hertz contact area, oil film thickness, and lubricant quality. It is between 1.9 pF and 34.7 pF. A shaft current test rig was developed. Based on the analysis results, orthogonal tests are set up to study the influence of voltage, rotation speed, and load on bearing operation. By using range analysis and variance analysis, the same conclusion is obtained: the most dominant factors affecting the raceway damage width, surface roughness, and vibration amplitude are voltage, load, and rotation speed, respectively. The mixed ceramic bearing and full-ceramic bearing are used instead of steel bearing to solve the problem of shaft current. Add conductive grease and non-conductive grease, respectively, and analyze and compare the advantages and disadvantages of different combinations from the perspective of temperature and friction and wear. The order from inferior to superior is steel bearing, hybrid ceramic bearing with ceramic outer ring, hybrid ceramic bearing with ceramic inner ring, hybrid ceramic bearing with ceramic ball and full-ceramic bearing. By using non-conductive grease, the damage is reduced by 16%–29%, surface roughness is reduced by 90%–122%, and vibration is reduced by 23%–176%. Under the same conditions, the bearings using non-conductive grease are better than those using conductive grease.
Mechanical properties and energy absorption capability of a topology-optimized lattice structure manufactured via selective laser melting under axial and offset loading
Authors: Wang Xi , Qin Ruixian , Chen Bingzhi
Published: May 2022

Intricate lattice structures can be fabricated by the selective laser melting method, which decreases the production limitations effectively and significantly provides more design freedom. In the present work, additive manufacturing and topological optimization are integrated to develop a novel body- and edge-centered 12 vertices lattice structure with modified triangular prismatic strut pattern (MTP-lattice). Finite element models of MTP-lattice were first established in PAM-CRASH and then experimentally verified via compressive test. The validated finite element models were then employed to investigate the novel MTP-lattice’s energy absorption and mechanical behavior under axial and offset loading. The results show that topology-optimized MTP-lattice has a superior energy absorption performance compared with competing unit cells. Besides, its mechanical performance is greatly influenced by the strut pattern and shape parameters. Furthermore, the deformation evolution from the overall structure to the strut level during the entire compression process was analyzed. The observations illustrate that the MTP-lattice exhibits a steady deformation mode with optimal shape parameters, which appears to have a promising prospect for the application of crashworthy components. The research results provide excellent guidance for the application of novel lightweight energy-absorbing lattice.
Characterization of a chiral metamaterial depending on the type of connection between unit cells
Authors: Akhmetshin Linar , Smolin Igor
Published: May 2022

The main focus in the development of metamaterials is on the design of multiscale structures, rather than on the chemical composition and properties of the base materials. In this work, a mechanical metamaterial is studied by mathematical modeling and computer simulations. A tetrachiral metamaterial structure is chosen due to its specific rotational behavior under uniaxial loading. Special attention is paid to the efficient use of the base material in the design of metamaterial samples. Two types of connection between unit cells in a macrobody are discussed: adjoining and overlapping. It is shown that a much less amount of the base material is used in 1D, 2D, and 3D samples consisting of overlapping cells. Numerical calculations of uniaxial loading of a system of two adjoining and overlapping cells showed that the adjoining cells act on each other, their contacting walls rotate in opposite directions due to chiral structure, and the sample is twisted. The overlapping cells have one common wall that rotates in one direction only, leading to a more pronounced twisting of the sample.
A sustainability approach to vehicle modular platform design: A mathematical model
Authors: Omidzadeh Davood , Sajadi Seyed Mojtaba , Bozorgi-Amiri Ali , Movahedi Sobhani Farzad
Published: May 2022

Today, sustainability and its economic, social, and environmental pillars are the main elements of new product market development. Therefore, manufacturers, considering all stages of a product life-cycle, consider it necessary to have a framework for producing sustainable products. Moreover, new product design and development processes especially sub-process of product definition and detailed design processes can play a very critical role in developing product sustainability. This paper considers the role that the car platform can play in creating a family of products and with regard to various data related to the environmental, economic, and social pillars of each of the 15 modules of a car platform and also, using the best–worst method technique and multi-objective mathematical programming with the augmented epsilon constraint method, we were able to achieve a set of platforms with maximum sustainability. The present study explores the possibility of determining the most efficient combinations of modules for every one of the 23 cars’ platforms to produce a collection of products. Through these methods, the 54 efficient solutions in the Pareto front were achieved, and out of this number, after considering all the factors and weights of the objective functions, solution no. 51 was selected as the most efficient. Subsequently, all the 15 module variants of the 23 platforms were determined for solution no. 51. Finally, these variants were ranked on the basis of the SAW technique, and finally, sensitivity analysis is done.
Hydrophobic properties and chemical state analysis of wear resistant coating prepared by electrical discharge process
Authors: Tyagi Rashi , Das Alok Kumar , Mandal Amitava , Saxena Kuldeep Kumar , Tripathi Ashutosh
Published: May 2022

Electrical discharge coating (EDC) process has been used to prepare a corrosion and wear resistant super-hydrophobic coating on the steel substrate. The coating process has been carried out by using three types of green compact tool electrodes (WS2/Cu, MoS2/Cu, and hBN/Cu). In these tool electrodes, powder mixing ratios (40:60, 50:50, 60:40) are varied, and their effect on coating characteristics (surface morphology, wettability, corrosion, and wear behaviour) has been studied. In this investigation, the morphology and chemical state of coating has been observed by using a scanning electron microscopy (SEM) and X-ray photoemission spectroscopy (XPS). SEM images of the applied coating show a porous and hierarchical structure. This hierarchical structure helps in raising the contact angle (CA) to 165.6° (super-hydrophobic state). The XPS analysis reveals that the deposition of solid lubricants takes place with their negligible disintegration into non-lubricating compounds. In addition, the prepared coating exhibits excellent resistance to wear and corrosion.
Influence of heat input on microstructure and mechanical behaviour of austenitic stainless steel 316L processed in wire and arc additive manufacturing
Authors: PS Gowthaman , S Jeyakumar , DT Sarathchandra
Published: May 2022

Wire arc additive manufacturing (WAAM) has long been considered an efficient method for producing medium- and large-sized components, due to its minimal material consumption, high deposition, superior structural quality and environmental friendliness. The ER 316L wire was employed as the filler metal in the fabrication process with varying heat input by altering welding current (C), wire feed speed (WFS) and travel speed (TS). The first portion of the studies involved producing single-bead welds by adjusting the heat input condition, while the second part involved fabricating three single-bead walls using optimum parameters determined in the first part of the research. The mechanical properties of SS316L samples remained impressively constant when WFS and TS were varied. The macroscopic morphology and microstructure of a thick-walled component were studied using a metallurgical microscope and optical electron microscopy. The mechanical properties of tensile study and micro-hardness analysis were reported. From a microstructural study, it can be observed that the deposited weld beads consist of a columnar structure with primary dendrites. The cooling rate and heat dissipation during the weld deposition process affect the variance of microstructure in different areas. The average micro-hardness value of various linear heat input manufactured components demonstrated stability, with values of 313, 249 and 398 HV, respectively. The hardness results of as-deposited walls provide a higher value in bottom regions due to heat accumulation. Tensile properties were determined parallel and perpendicular to the deposition directions; decreased heat input resulted in superior mechanical properties in terms of tensile characteristics. From the tensile properties, the mean values of various heat input SS 316L ultimate tensile strength, yield strength and elongation were found to be 426 MPa, 304 MPa and 20%, respectively. Fractography showed typical dimple fracture characteristics in all the specimens. It is clear from the current research that parts made by WAAM exceed their 316L casting parts and wrought alloy.
Experimental investigation of a novel magnetorheological process based on three revolving curved tip tools for finishing of mild steel
Authors: Singh Gagandeep , Jayant Arvind
Published: May 2022

High-quality surface of the cylindrical workpieces would have to be very precise when used in automobile industries, vane pumps, turbines, gears, mild steel dies and punches for plastic industries. The magnetorheological finishing process based on three revolving curved tip tools has been developed for external cylindrical components to address the above issues. Three electromagnetics tools have been used in this magnetorheological method that can move radially inwards or outwards according to the external diameter of the workpiece. During finishing, the workpiece rotates in the anti-clockwise direction, and three curved tip tools revolve around the workpiece in a clockwise direction resulting in more interaction between the workpiece and active abrasive particles. Reciprocating movement is also provided to the workpiece that helps to produce the axial force on the active abrasive particles. The proposed method has been applied to a mild steel shaft to investigate the surface finish of its external surface. Response surface methodology (RSM) has been used to plan and analyse the impacts of different process factors on the percentage change in surface roughness value of the finished surface of the mild steel stepped cylindrical shaft. The optimal combination of process parameters is magnetising current 3.4A, revolving speed of tools 26 rpm, the rotational speed of workpiece 440 rpm, and transverse speed of workpiece 20 cm/min, which shows the maximum percentage change in the surface roughness value. Confirmation experiments have been performed at optimal combination. The lowest Ra value of 85 nm (nanometre) has been achieved from the initial value of 410 nm (nanometre) in the finishing duration of 90 min. The roughness profiles, scanning electron microscopy (SEM) test and reflection test show that the current finishing process can meet high standards for surface quality that aren't possible with conventional methods.
Thermal radiation and melting phenomena in bio-convective flow of third-grade nanomaterial
Authors: Hayat T. , Ullah Inayat , Muhammad Khursheed , Alsaedi A.
Published: May 2022

In this article flow of third grade, nanofluid in presence of bioconvection by a stretched sheet is examined. Motile microorganism is addressed. Surface is subject to melting effect. Heat transfer is examined through viscous dissipation and thermal radiation. Buongiorno model elaborated nanofluid features. Uniform applied magnetic field is taken normal to the flow. Mathematical modeling of the considered problem is formulated by constructing PDEs. Such system of PDEs is then transmitted into ODEs through suitable transformations. The nonlinear (ODEs) are then tackled through ND solve (numerically). Influences of considered variables on temperature distribution, velocity profile, concentration, and microorganism density are expressed and presented graphically.
Multi objective ant Colony Optimisation to obtain efficient metro speed profiles
Authors: Fernández Pablo Martínez , Font Torres Juan B , Sanchís Ignacio Villalba , Franco Ricardo Insa
Published: May 2022

Obtaining efficient speed profiles for metro trains is a multi-objective optimisation problem where energy consumption and travel time must be balanced. Automatic Train Operation (ATO) systems may handle a great number of possible speed profiles; hence optimisation algorithms are required to find efficient ones in a timely manner. This paper aims to assess the performance of a particular meta-heuristic optimisation algorithm, a variation of the traditional Ant Colony (ACO) modified to deal with multi-objective problems with continuous variables: MOACOr. This algorithm is used to obtain efficient speed profiles in up to 32 interstation sections in the metro network of Valencia (Spain), and the convergence and diversity of these solution sets is evaluated through metrics such as Inverse Generational Distance (GD) and Normalised Hypervolume (NH). The results are then compared to those obtained with a conventional genetic algorithm (NSGA-II), including a statistical analysis to identify significant differences. It has been found that MOACOr shows a better performance than NSGA-II in terms of convergence, regularity and diversity of the solution. These results indicate that MOACOr is a good alternative to the widely used genetic algorithm and could be a better tool for rail operation managers trying to improve energy efficiency.
Vertical thrust-based effective flat-spin recovery of aircraft restricting altitude loss
Authors: Salahudden Salahudden , Ghosh Ajoy K
Published: May 2022

Among the various modes of aircraft spin, flat-spin being the most ruthless form, the severity and the flight parameters govern the recovery success rate. This paper presents a novel approach for utilizing vertical thrust to reduce the fatality of the flat-spin in terms of excessive altitude loss regulating the survivability post aircraft recovery. F-18 High Alpha Research Vehicle is considered for the present study to demonstrate effectiveness of the proposed method. The dynamics of vertical thrust add-on is conceptualized and incorporated to the standard aircraft. Subsequently, to validate the effectiveness of this mode of recovery as compared to the conventional primary control based method, standard sliding-mode control technique is adopted. Closed-loop simulation shows that vertical thrust restricts altitude loss and minimizes spin recovery time compared to the conventional mode of recovery from flat-spin. The outcome of the present study ensures the use of vertical thrust as a potential solution for minimizing aircraft flat-spin-related fatal accidents.
The effect of rocker sole shoes on ground reaction force in the elderly
Authors: Hemmati Fatemeh , Karimi Mohammad Taghi
Published: May 2022

Aging is associated with decreases in gait performance and mobility. Toe-only rocker sole is prescribed as a common shoe modification in restricted foot and ankle joints mobility. Therefore, this study aimed to determine the effect of toe-only rocker sole shoes on the ground reaction force (GRF) in the elderly. Twenty-one older adults walked on a walkway equipped with one force plate under six different conditions including barefoot (BF), normal shoe (NS), and four types of toe-only rocker sole shoes (RS) with various degrees of rocker angle (RS10, RS20, RS30, and RS40). The peaks of the GRFs in three planes were obtained. Different rocker angles could affect GRF parameters. The first peak of GRF (FZ1) significantly increased with both RS30 and RS40 compared to BF, NS, RS10, and RS20. FZ1 significantly decreased with RS30 compared to RS40. The braking force (FX1) was significantly lower with NS compared to RS30 and RS40. FX1 was significantly higher with RS40 compared to the other shoe conditions. The propulsive force (FX2) significantly decreased during walking with BF compared to NS, RS20, RS30, and RS40. A higher FX2 was observed in RS40 than the other shoe conditions except RS30. Also, FX2 was significantly lower with RS10 compared to RS30. Increasing rocker angle may result in an increase in the peak magnitude of FZ1, FX1, FX2 in the elderly without any improvement in walking speed.
Neurotoxic 18-kDa apolipoprotein E fragment production contributes to anesthetic sevoflurane-induced tau phosphorylation and neuroinflammation in vitro
Authors: Yu Yang , Yang M , Zhuang X , Pan J , Feng J , Yu J , Yu Yonghao
Published: May 2022

Anesthesia may induce neuronal tau phosphorylation and neurotoxicity in the developing brain. Apolipoprotein E (ApoE) may play a protective role in neuronal activity and injury repair, whereas its 18-kDa fragments are reported to induce neurodegeneration and neuroinflammation in Alzheimer’s disease patients. We aimed to test the hypothesis that differences in 18-kDa ApoE fragment levels, but not full-length ApoE, in primary neurons contribute to differences in tau phosphorylation and neuroinflammation with or without sevoflurane administration. Neurons extracted from wild-type (WT), ApoE knockout (ApoE-KO), and ApoE ε3-and ε2-targeted replacement (ApoE ε3, ApoE ε2) mice were divided into control and sevoflurane groups. Neurons in the sevoflurane group were treated with 21% O2, 5% CO2, and 4.1% sevoflurane, whereas those in the control group were treated with 21% O2 and 5% CO2 only on day 5 of neuronal culture. ApoE mRNA, full-length ApoE, 18-kDa ApoE fragments, Tau-PS202/PT205 (AT8), Tau-PSer396/404 (PHF1), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 and IL-1β levels were measured. The data showed that sevoflurane-induced AT8 and PHF1 increases, and TNF-α, IL-6, and IL-1β increases in WT or ApoE ε3 neurons (both expressing full-length and 18-kDa fragmented ApoE) could be mitigated in ApoE ε2 (only expressing full-length ApoE), but not in ApoE-KO neurons, indicating that differences in 18-kDa ApoE fragments, but not full-length ApoE, in primary mouse neurons contributed to differences in tau phosphorylation and neuroinflammation with or without 4.1% sevoflurane administration.
‘It’s just a Band-Aid!’: Public engagement with geoengineering and the politics of the climate crisis
Authors: Carvalho António , Riquito Mariana
Published: May 2022

Geoengineering consists of a set of techniques whose aim is to avoid the disastrous consequences of global warming, such as solar radiation management and carbon dioxide removal. Due to its controversial nature, over the past decade various exercises of public participation with geoengineering have been put in place, particularly in the Global North. This article draws on empirical data stemming from six online focus groups on public engagement with geoengineering conducted in Portugal. In contrast to previous research, we included situated publics to emphasize the political implications of geoengineering, bringing to the debate those with a potential stake in the matter – environmentalists, activists, university students, science communicators and promoters of holistic practices. We suggest that the elusive and uncertain character of geoengineering moves the discussion away from its technological specificity, bringing to the fore some of the socio-political, economic and ethical tensions underpinning the climate crisis.
Porosity Is the Heart of Religion
Authors: Luhrmann Tanya Marie , Weisman Kara
Published: May 2022

When scholars and scientists set out to understand religious commitment, the sensation that gods and spirits are real may be at least as important a target of inquiry as the belief that they are real. The sensory and quasisensory events that people take to be the presence of spirit—the voice of an invisible being, a feeling that a person who is dead is nonetheless in the room—are found both in the foundational stories of faith and surprisingly often in the lives of the faithful. These events become evidence that gods and spirits are there. We argue that at the heart of such spiritual experiences is the concept of a porous boundary between mind and world, and that people in all human societies have conflicting intuitions about this boundary. We have found that spiritual experiences are facilitated when people engage their more porous modes of understanding and that such experiences are easier for individuals who cultivate an immersive orientation toward experience ( absorption) and engage in practices that enhance inner experience (e.g., prayer, meditation). To understand religion, one needs to explore not just how people come to believe in gods and spirits, but how they come to understand and relate to the mind.
Disrupting Disruptions: Charting and Challenging Notions of Gender in Philippine Feminist Theologizing
Authors: Sanchez Rae
Published: May 2022

The growing discipline of feminist theology in Asia and in the world, which involves many Filipinas, entails an increasing attentiveness to gender diversity beyond heteronormative expectations and a broader sense of solidarity among women and others who have experienced exclusion due to gender. An analysis of writings by Philippine feminist theologians Mary John Mananzan, Judette Gallares, and Agnes Brazal, using a threefold schema of “inclusion/addition,” “deconstruct and transform,” and “critique, reject, and start again,” reveals heteronormative gender assumptions and a pattern of moving beyond these. This shows that feminist theologizing is a very dynamic activity that adapts and responds to new ideas flexibly. One common theme that emerges out of feminist theologizing is the image of the babaylan, which provides an opportunity for greater solidarity with various gender identities as a vernacular resource and root metaphor.
Massacre at Tambach: American War Criminals and the Limits of Military Justice, 1945
Authors: Schneider Benjamin M.
Published: May 2022

In April of 1945, members of the U.S. army massacred twenty unarmed prisoners near Tambach, Germany. This paper examines the army's response, and why despite abundant evidence and multiple confessions the military justice system failed to convict anyone for the crime. The system faltered due to an incomplete shift in the nature of military justice, one that sought to turn it from a disciplinary tool into one capable of punishing war criminals. The incident at Tambach was not unique, and instead shows a system in crisis – one unable to hold soldiers accountable for illegal violence on the battlefield.
Moral experiences in caring for voluntary pregnancy losses: A meta-ethnography
Authors: Fernández Basanta Sara , Bouzas-González Iria , Coronado Carmen , Movilla-Fernández María-Jesús
Published: May 2022

Voluntary abortions are relatively frequent and their care is complex due to the social stigma that surrounds these losses. This interpretive meta-ethnography of 11 original qualitative articles aims to synthesize the moral experiences of nurses and midwives who cared for women and couples that decided to abort or terminate the pregnancy due to foetal abnormalities. Lines of argument synthesis emerged after reciprocal and refutational translations, together with the metaphor, ‘Going with the flow or swimming against the tide’. Caring in these situations was an ethical dilemma when a conflict existed between their professional duty and their moral principles. In these instances, care was associated with a significant emotional cost. They did not feel sufficiently prepared or with adequate resources, which favoured avoidance behaviours. However, the feeling of professional duty was stronger than their prejudices, and they became engaged in caring. These results could improve knowledge, clinical practice and education, being a (highly) reasonable representation of the phenomenon of interest.
Professional values in student nurse education: An integrative literature review
Authors: Antoniou Carolyn , Clifton Ross , Wilson Valerie
Published: May 2022

Aim

The aim is to understand current research into the impact of undergraduate nursing education on the development of professional values.

Background

Values are evident in the professional standards for nurses and the guidelines and healthcare policies of many countries. These professional values guide decisions and behaviour and are recognised as an essential component in the professions ability to provide safe and professional care. This literature review presents the current research on the impact of education on professional values in undergraduate nurse education.

Design

An integrative review of the findings was conducted to provide insight into the current research on the professional value development in undergraduate nurses.

Data sources

CINAHL, PubMed and Scopus.

Review methods

A literature search was undertaken within defined date parameters 2010–2021 using a systematic approach. The Preferred Reporting Items for Systematic Reviews and Meta-analysis guide PRISMA was used to guide and illustrate the process. Papers were assessed for quality using the Mixed Methods Appraisal Tool.

Results

Two distinct areas of inquiry were identified. (a) Changes in professional values as an outcome of undergraduate nursing education or (b) changes in professional values as an outcome of specifically designed educational content. These areas were further explored to better understand the influences of undergraduate education on students’ professional values.

Conclusion

There is a lack of evidence in the literature to support the premise that professional values develop in line with academic year progression; however, there is strong evidence to support the inclusion of explicit learning in undergraduate education that engages students in education specifically designed to explore and develop professional values.
The Hiring of Labour for Field Cultivation: A Study in the Brahmaputra Valley of Northeast India
Authors: Das Anup Kumar
Published: May 2022

On the basis of household-level data, the present study examines the hiring of farm labour in the Brahmaputra Valley of Assam in the north-eastern part of India. By adopting a multi-stage sampling technique, the primary data were collected from 237 randomly selected field crop cultivating households located in the lower, upper and central parts of the Brahmaputra Valley. The hiring of labour for field cultivation is extensive among the sample farm households of all size groups, but it varies across locations and activities. There are three forms of farm labour hiring, among which the hiring of labour on daily basis is common and pre-dominant. The wage of farm labourers is not same across activities, sex and locations. The estimation of independent double hurdle model depicts the farm size, type of cultivator and age of head of the household as the common factors that affect both the adoption and the extent of hiring of farm labour. The availability of family labour is another factor that affects the extent of hiring of farm labour.
The Growth Volatility Relationship: A Spatial Panel Analysis of the States of India
Authors: Patnaik Anuradha
Published: May 2022

The impressive growth rate of the Indian economy and the subsequent signs of slowdown in the last few years have warranted the need to revisit the issue of determinants of growth. While most of the studies on economic growth in India focus on the demand and supply factors, which determine the growth rate, volatility as a major determinant of long-run growth (Kydland & Prescott, 1982, Econometrica: Journal of the Econometric Society, 1345–1370) has been ignored by most researchers. The present study attempts to fill the gap using data from 17 major states of India in a spatial panel data framework for the period 1995–2015. The results of empirical analysis clearly reveal that a significant and inverse relationship exists between volatility and growth in India. Also, the significant spatial effects in the growth regressions, highlight the importance of the role played by spillovers from adjoining areas, in the growth process. The results clearly highlight the important role that countercyclical policies can play in improving the growth rate of India.
A longer duration from injury to surgery is associated with preoperative deterioration of an isolated meniscal tear in patients aged 40 years or older
Authors: Yokoe Takuji , Tajima Takuya , Yamaguchi Nami , Morita Yudai , Chosa Etsuo
Published: May 2022

Purpose

To evaluate the preoperative deterioration of an isolated meniscal tear in patients aged 40 years or older, and whether time from injury to surgery is associated with worsening of a meniscal tear.

Methods

Patients aged 40 years or older who underwent arthroscopic surgery for isolated meniscal tear between 2014 and 2019 were retrospectively reviewed. The diagnostic magnetic resonance imaging (MRI) findings and arthroscopic findings were compared to evaluate the deterioration of meniscal tears. Predictors of the development of meniscal tears; patient demographic factors, duration from injury to surgery (injury to MRI and MRI to surgery), and image findings were assessed.

Results

A total of 58 patients (58 knees) were included (mean age, 55.9 ± 8.5 years; male/female, 31/27). An isolated meniscal tear deteriorated in 28 (48.3%). Compared patients with and without deteriorated meniscal tear, significant differences were found in the MRI grade of meniscal tear ( p = 0.03), duration from injury to MRI (164.2 ± 167.9 vs 45.2 ± 48.7 days, p < 0.001), and from MRI to surgery (148.8 ± 91.1 vs 67.6 ± 56.7 days, p < 0.001). A multivariate regression analysis showed that the duration from injury to MRI (odds ratio [OR], 1.03; p < 0.001) and from MRI to surgery (OR, 1.02; p < 0.001) were independent predictors.

Conclusion

Approximately 50% of isolated meniscal tears deteriorated preoperatively in patients aged 40 years or older. The duration from injury to surgery was an independent predictor of worsening of an isolated meniscal tear.
Trans tibial amputation with or without a tourniquet in patients with diabetic foot infection and peripheral vascular disease: Comparison of postoperative outcomes
Authors: Gurel Ron , Elbaz Etay , Ashkenazi Itay , Rotman Dani , Factor Shai , Chechik Ofir , Warschawski Yaniv , Albagli Assaf
Published: May 2022

Background: Transtibial amputation (TTA) due to complications of diabetic foot infection (DFI) or peripheral vascular disease (PVD) is a high-risk procedure in fragile patients. The risks of reoperation, blood loss requiring blood transfusion, and mortality are high. The use of a tourniquet in this procedure is controversial and scarcely reported. Objective: this study aimed to compare the outcomes of TTAs with or without a tourniquet in a single tertiary medical center. Methods: We retrospectively identified all patients who had undergone TTA in our institution (1/2019-1/2020) and included only those who underwent the procedure due to complications of DFI or PVD ( n = 69). The retrieved data included demographics, comorbidities, ASA score, the use of a tourniquet, operation duration, pre- and postoperative hemoglobin levels, administration of blood transfusions, hospitalization length, surgical site infection and 60-days reoperation and mortality rates. Results: TTA with a tourniquet was superior to TTA without a tourniquet in reducing the average operation length by 11 min ( p = 0.05), the median postoperative hospitalization by 6 days ( p = 0.04), and the use of blood transfusions (odds ratio [OR] = 0.176, 95% confidence interval [CI]: 0.031–0.996). Conclusions: Our findings demonstrated advantages in operative time, hospitalization length, and blood transfusion requirement for TTA with a tourniquet compared to TTA without a tourniquet.