bluuebunny/crossref_metadata_2025 huggingface dataset:
Influencing Factors of Teachers’ Sharing Behaviors of Digital Teaching Resources in Online Teaching Activities
Authors: Wen LiWen
Published: March 2022

Abstract—A scale for the influencing factors of teachers’ sharing behaviors of digital teaching resources in online teaching activities based on IMBP (Integrative Model of Behavioral Prediction) theoretical model and behavioral motivation theory was designed in this study. Then, the major influencing factors were explored. Results demonstrate that the Cronbach α and KMO values are 0.935 and 0.831, indicating good reliability and validity of the designed questionnaire. Sharing motivation and sense of self-efficacy significantly and positively affect the teachers’ sharing behaviors in online teaching activities. In contrast to work stress with no significantly negative effects, awareness of knowledge protection has significantly negative effects on teachers’ sharing behaviors. Sharing atmosphere provides complete and partial mediating effects on the negative effects of work stress and awareness of knowledge protection. The effects of school location (urban or rural), school type, and teaching age on teachers’ sharing behaviors are all significant on the 0.05 level. The obtained conclusions provide important references to the strengthening of technological and teaching supports to teachers, create a generous sharing atmosphere of digital resources, and contribute to the deep and wide propagation of digital resource sharing.
Optimal Allocation of Mobile Learning Resources Based on a Complex Network
Authors: Han Ling , Zhao Jing
Published: March 2022

Currently, centralized online learning can no longer meet the fragmented learning needs of learners. It is a hot topic in mobile learning to allocate reasonable mobile learning resources (MLRs) for user terminals and servers. However, the existing studies have rarely discussed the matching relationship between the MLR features of user terminals and servers. To fill up the gap, this paper tries to optimize the allocation of MLRs based on the theory of mobile knowledge complex network. Firstly, a local bidirectional fitness model was established to optimize MLR allocation, and the core nodes were mined from the complex network of MLRs. Next, the authors clarified the causality between the density of MLR complex network and resource integration, constructed an evaluation index system (EIS) for MLR integration ability, and evaluated the overall resource integration ability of MLR network resources. The proposed network was proved effective in optimizing the resource allocation of mobile learning networks through experiments.
Exhiber le crime vaincu : les fourches patibulaires et la justice criminelle sous l’Ancien Régime
Authors: Regina Christophe
Published: March 2022

S’intéresser à la question des fourches patibulaires consiste à étudier avant tout l’histoire du pouvoir et de ses représentations, la mise en scène symbolique de ce dernier et son ancrage physique dans l’espace et le temps. Les fourches patibulaires participent à l’affirmation du pouvoir royal, depuis que la monarchie a entrepris la reconquête de son autorité de façon plus marquée sous les Valois et les Bourbon qui ont réorganisé profondément l’administration du royaume et plus particulièrement celle de la justice. Cette réorganisation se manifeste avec éclat sous le règne de Louis XIV et souligne de fait un redéploiement des prérogatives judiciaires des seigneurs du royaume. L’objet de cet article est de montrer de quelles manières l’usage des fourches patibulaires permet au monarque d’affirmer son autorité, non seulement en domestiquant une noblesse qui ne remplit plus vraiment ses fonctions premières, à savoir celles de la guerre, jalouse de ses privilèges, mais aussi en domestiquant ses sujets qu’il faut éduquer afin de préserver le repos public. Il s’agira également de penser en terme de représentations : Les fourches patibulaires, si elles étaient redoutables, étaient-elles pour autant redoutées ?
Development of Eco-Friendly Bio-Oil-Bitumen from Local Materials
Authors: Hassan Hassan N. , Ahmed Taher M. , Abd Duraid M.
Published: March 2022

The substantial increases in bitumen pricing due to increasing in demand for petroleum derived products in line with decreasing world crude resources has suggested that all industries, including the asphalt pavement industry, should be exploring economically, socially, and environmentally sustainable approaches either to enhance the performance of asphalt mixture using some recycled materials or developing eco-friendly asphalt mixture. The current study presents new development of eco-friendly bio-oil-bitumen produced using some local materials. Two bitumen sources 40-50 Pen were used, Dora and Nasiriyah, obtained from Dora and Nasiriyah refineries. Waste cooking oil was collected from local households and cafeterias without financial cost. Methanol, Sulfuric acid (as a catalyst), and Zeolite were considered in the development process. Initial results highlighted that the modified bio-oil-bitumen has shown superior performance compared to that of traditional bitumen. The current successful development has an encouragement to further characterization of such production.
Polyethylene Glycol Propargyl Ethers Based Curing Agents for Glycidyl Azide Polymer
Authors: Yan Zheng Feng , Gao Fu Lei , Zhao Bao Dong , Chen Bin , Hu Lan , Wang Ying Dei
Published: March 2022

Three polyethylene glycol propargyl ethers (PGPEs), namely 4,7,10-trioxatrideca-1,12-diyne (TOTDY), 4,7,10,13-tetraoxahexadeca-1,15-diyne (TOHDY) and 4,7,10,13,16-pentaoxanonadeca-1,18-diyne (TONDY) were designed and successfully synthesized as curing agents for glycidyl azide polymer (GAP). Their structures were characterized by FT-IR, 1H NMR, 13C NMR and elemental analysis, and their glass transition temperatures (Tg) were measured by DSC. The films of GAP cured by the title compounds were prepared via 1,3 dipolar cycloaddition, and then the influences of PGPEs on the Tg, decomposition temperature (Td) and mechanical properties of the films were studied accordingly. The results showed that the Tg of GAP cured by TOTDY and TOHDY were-38.1 oC and-38.2 oC, respectively. The Td of GAP cured by PGPEs was in the range of 235.5 oC - 241.0 oC. The results of tensile tests showed that the maximum stress of GAP films cured with PGPEs were in the range of 0.11 MPa to 0.52 MPa at elongation from 29% to 48%. These results indicated that PGPEs would have potential application in GAP based high energy solid propellant formulations.
Facet-Dependent Electrocatalytic Reduction of CO2 to HCOOH over Pd Nanoparticles
Authors: Rao Hou Dong , Lin Chong , Wang Wen Fei , Wang Bing , Cheng Wei , Lin Xin Zhi
Published: March 2022

Pd is one of the most promising catalysts for carbon dioxide electroreduction (CO2RR) to formate (HCOO-). However, the lack of understanding of the active phase remains remains obscure with the role of different crystal facets in the formation of formic acid. Herein, Pd nanocubes and nanooctahedra particles with Pd (100) and (111) facets were, respectively, prepared. Compared with ordinary Pd nanoparticles and Pd octahedra, Pd nanocubes exhibited the most excellent electrocatalytic performance of carbon dioxide reduction, achieving a Faraday efficiency of 96% for formate production at a low applied potential of-0.20 V (vs RHE) in 0.5 M KHCO3. At the same time, first-principles theoretical calculations also showed that the Pd (100) surface is more conducive to the conversion of CO2 to HCOO* intermediates, thereby promoting the formation of formic acid. This result indicates that the Pd (100) crystal plane is more conducive to the reduction of CO2 to formate. This research has important guiding significance for exploring the efficient reduction of carbon dioxide to formic acid catalyst.
A Financial Resource but a Disloyal Group: Inquiring Sri Lankans’ Perceptions towards ‘Sri Lankan Migrants’
Authors: Jayawardena P.
Published: March 2022

Sri Lankan emigrants are a heterogeneous community comprised by nearly three million different types of temporary and permanent migrants from refugees, domestic workers, irregular boar migrants, skilled migrants to students. However, Sri Lankans who are living in Sri Lanka do not know much about their emigrants’ lives, their migratory experiences or their diversity. The objective of this study is to explore the Sri Lankan society’s imagining of the Sri Lankan migrant and the factors that affect such imaginations. The data is collected through a range of methods such as observations, interviews with migrants and natives, and discourse analyses of debates, discussions and policy documents. Thematic analysis is used to analyse the data. The study reveals that Sri Lankan society has a contradictory dual approach in viewing their migrants: on one hand they view migrants positively - as a financial resource and on the other hand they view them negatively - as a group of disloyals. Non-migrant Sri Lankans have arrived into the latter assumption based on a nation-state premise. They consider a person’s physical residence of a territory as the marker of his or her loyalty. Referring to the transnational literature, I show that this is an outdated home country perspective through which migrants’ newer realities are not adequately captured. With the developments of migration laws, transportation and telecommunication, the conventional physical distance between migrants’ host and home lives has been radically reduced today. Thus, I highlight the need for the Sri Lankan society to view their migrants within a transnational frame, instead of the traditional nation-state frame they still use. Transnational framework would facilitate the Sri Lankan society to see migrants’ newer realities through updated lenses and consequently to establish a more meaningful relationship with them.
Impact of Labor Costs and Investment in Human Capital on Financial Performance: Evidence from Listed Companies in Sri Lanka
Authors: Kantha W. N. R. A. , Weligamage S. S.
Published: March 2022

The wealth of a company depends on physical assets and intangible assets. The objective of this study is to identify the impact of labor costs and investment in human capital on the financial performance of listed companies in Sri Lanka.   The study is based on secondary data and collected from published annual reports of the selected listed companies in Sri Lanka over the period of 2014 and 2018. The sample consists of fifty-nine (59) companies selected using stratified sampling covering both high and low market capitalization companies in each sector for a period of five (05) years. Labor cost, Investment in human Capital, Return on Assets (ROA) and Earning per share are the variables included in the study. Findings proved that there is a significant positive impact of average Labor Cost on ROA and there is a weak positive correlation between earning per share and average labour cost. Companies with high market capitalization show a moderate positive correlation and companies with low market capitalization are not statistically significant. This study concluded that labour cost and investment in human capital have a positive impact on the financial performance of Sri Lankan listed companies and this relationship is varied based on market capitalization. So, the efforts taken by companies to improve human capital is encouraging and those may directly influence the value creation process of an organization.
Retinal vessel diameters: Can they predict future risk of infertility in patients with varicocele?
Authors: Ghanem Mazen A. , Adawi Essa A. , Ghanem Ahmed M. , Safan Manal A. , Ghanem Asaad A.
Published: March 2022

Objective: The objective of this study was to assess the relationship between retinal vessel diameters, such as retinal arteriolar diameter, retinal venular diameter, and arteriolar/venular ratio (AVR), as clinical parameters of fertility in varicocele patients. Materials and methods: Sixty-eight (68) infertile varicocele men with abnormal semen parameters and sixty-one (61) varicocele normozoospermic men were included in the study. Moreover, fifty-eight (58) healthy normozoospermic men without varicocele were enrolled as a control group. For each participant, retinal vascular diameters were measured from the digital retinal photographs as a central retinal arteriolar equivalent (CRAE), central retinal venular equivalent (CRVE), and AVR. In addition, hormones (total testosterone and FSH), and semen parameters were assessed and correlated with retinal vessel diameters. Results: The mean CRAE, CRVE, and AVR values were 147.8 ± 15.8 μm, 198.3 ± 39.3 μm, and 0.61 ± 0.01 in infertile varicocele patients, respectively. Significant difference of CRAE, CRVE, and AVR were found when comparing infertile varicocele patients with both varicocele and control normozoospermic male groups (p = 0.01, p = 0.006, and p = 0.007; respectively). Larger retinal venular caliber and smaller AVR ratio showed a significant inverse correlation with both sperm parameters and hormones (total testosterone and FSH) (p < 0.05). No significant correlations were found between CRAE with both sperm parameters and hormonal values (total testosterone and FSH) (p > 0.05). Conclusions: Infertile patients with varicocele showed a significant relationship with the retinal vascular diameter (CRVE and AVR ratio). This finding supports recommendation for regular eye examinations in the varicocele population.
Infectious complications of endourological treatment of kidney stones: A meta-analysis of randomized clinical trials
Authors: Bapir Rawa , Bhatti Kamran Hassan , Eliwa Ahmed , García-Perdomo Herney Andrés , Gherabi Nazim , Hennessey Derek , Mourmouris Panagiotis , Ouattara Adama , Perletti Gianpaolo , Philipraj Joseph , Trinchieri Alberto , Buchholz Noor
Published: March 2022

Objective: Endourological treatment is associated with a risk of postoperative febrile urinary tract infections and sepsis. The aim of this study was to review the reported rate of infectious complications in relation to the type and modality of the endourologic procedure. Methods: This systematic review was conducted in accordance with the PRISMA guidelines. Two electronic databases (PubMed and EMBASE) were searched. Out of 243 articles retrieved we included 49 studies after full-text evaluation. Results: Random-effects meta-analysis demonstrated that retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) were associated with not significantly different odds of getting fever (OR = 1.54, 95% CI: 0.99 to 2.39; p = 0.06) or sepsis (OR = 1.52, 95% CI: 0.37 to 6.20, p = 0.56). The odds of getting fever were not significantly different for mini PCNL compared to standard PCNL (OR = 1.11, 95% CI: 0.85 to 1.44; p = 0.45) and for tubeless PCNL compared to standard PCNL (OR = 1.34 95% CI: 0.61 to 2.91, p = 0.47). However, the odds for fever after PCNL with suctioning sheath were lower than the corresponding odds for standard PCNL (OR = 0.37, 95% CI: 0.20 to 0.70, p = 0.002). The odds of getting fever after PCNL with perioperative prophylaxis were not different from the corresponding odds after PCNL with perioperative prophylaxis plus a short oral antibiotic course (before or after the procedure) (OR = 1.31, 95% CI: 0.71 to 2.39, p = 0.38). Conclusions: The type of endourological procedure does not appear to be decisive in the onset of infectious complications, although the prevention of high intrarenal pressure during the procedure could be crucial in defining the risk of infectious complications.

 

on behalf of U-merge Ltd. (Urology for emerging countries), London-Athens-Dubai
Emergency medicine residents in Italy: Data from a national survey
Authors: Piazza Isabelle , Barcella Bruno , D'Ercole Adriana , Zaccaria Gianpiero , CoSMEU group
Published: March 2022

CoSMEU group (Italian Society of Emergency Medicine Residents): Cascio Michela, Ceschi Ludovica, Di Cristoforo Monica, La Spina Letizia, Malacarne Cecilia, Pons Sofia, Silvestri Giulia.

 

Emergency Medicine (EM) is a novel specialty in Italy. It exists only since 2009, and CoSMEU (Coordinamento Specializzandi Medicina d’Emergenza-Urgenza) is the national association of EM residents. On behalf of CoSMEU, we conducted an electronic survey open to all the Italian EM residents, with the aim to assess their awareness about the acquisition of technical skills and clinical knowledge during the academic year 2019-2020. Out of 1666 EM residents, 434 (26%) responded to the survey, in representation of all the 33 medical school programs. For 63.6% of them EM was their first-choice program. A high percentage of EM residents have denounced a lack of education and hands-on opportunities to fully complete their training as planned, in the absence of simulation and certifications, and with not-standardized educational programs across the EM schools. Although the Italian EM and specialty are currently facing a crisis, all the EM residents are working hard to support EM system optimization.
Mixed Witt rings of algebras with involution
Authors: Garrel Nicolas
Published: March 2022

Although there is no natural internal product for hermitian forms over an algebra with involution of the first kind, we describe how to multiply two
$\varepsilon $
-hermitian forms to obtain a quadratic form over the base field. This allows to define a commutative graded ring structure by taking together bilinear forms and
$\varepsilon $
-hermitian forms, which we call the mixed Witt ring of an algebra with involution. We also describe a less powerful version of this construction for unitary involutions, which still defines a ring, but with a grading over
$\mathbb {Z}$
instead of the Klein group.

We first describe a general framework for defining graded rings out of monoidal functors from monoidal categories with strong symmetry properties to categories of modules. We then give a description of such a strongly symmetric category
$\mathbf {Br}_h(K,\iota )$
which encodes the usual hermitian Morita theory of algebras with involutions over a field K.

We can therefore apply the general framework to
$\mathbf {Br}_h(K,\iota )$
and the Witt group functors to define our mixed Witt rings, and derive their basic properties, including explicit formulas for products of diagonal forms in terms of involution trace forms, explicit computations for the case of quaternion algebras, and reciprocity formulas relative to scalar extensions.

We intend to describe in future articles further properties of those rings, such as a
$\lambda $
-ring structure, and relations with the Milnor conjecture and the theory of signatures of hermitian forms.
Impact of the Vehicle Environment on the Thermal Behavior of the Electrical Wiring
Authors: Brabetz Ludwig , Ayeb Mohamed , Koppe Christian , Hesse Benjamin
Published: March 2022

The thermal behavior of wires within the electrical distribution system (EDS) has a strong impact on the conductor cross section, the type of insulation, the derating, and the fusing system, and therefore on weight, cost, and reliability. Consequently, significant efforts have been made to develop sound static and dynamic thermal models for single wires and wire bundles. However, these models are based on the simplifying assumption that the object is completely surrounded by air, where, with the exception of free convection, airflow can be neglected, and where no interaction with other objects is considered.

The approach presented in this paper takes into account the actual environment and routing within a vehicle, where some objects such as metal sheets can be considered as heat sinks and other objects, e.g. a motor block, as heat sources. For this reason, measurements were performed using an experimental set-up that allows any desired positioning and alignment of the DuT (device under test, here: wire, cable, bundle) and of two temperature-controlled heat source/sink objects. These objects are a large rectangular surface and a small sphere, in order to be able to emulate as many spatial configurations as possible. The overall set-up is protected against externally-induced airflows. Because the exact modelling of the heat transfer processes (radiation, conduction, and free/forced convection) would require time-consuming FEM calculations for the investigated complex geometries, a simplified and partially data-driven model is proposed. The paper describes the theory and the modeling approach, and presents initial simulation and measurement results.
Development and Application of J3112: A/C Compressor Oil Separator Effectiveness Test Standard
Authors: Taylor Dwayne
Published: March 2022

SAE Standard J3112 – “A/C Compressor Oil Separator Effectiveness Test Standard” - has been developed to provide an analytical means of determining if an a/c compressor with oil separator functionality meets the U.S. EPA criteria of a minimum 50% effectiveness in order to qualify for menu credits for greenhouse gas reduction, as specified in the U.S Government Code of Federal Regulations (CFR) Title 40, §86.1868-12. At the start of the EPA’s a/c efficiency credit program in 2017 OEMs could qualify for greenhouse gas menu credits without providing data on the effectiveness of the product being implemented, but EPA regulations required supporting data from 2020 MY through the end of the current published regulations in 2026 MY. J3112 was developed by the SAE Interior Climate Control MVAC Supplier Committee (TEVBES2E) in order to provide a standardized procedure for determining oil separator effectiveness in order to comply with the EPA requirements for 2020-2026 model years. This paper provides background on how J3112 was developed, and how it is used in order to provide documentation necessary to apply for Oil Separator credits with the EPA, in conjunction with SAE Recommended Practice J3174, “Recommended Practice for an Engineering Analysis for A/C Efficiency Credits”.
Copyright Statement
This paper puts into writing the material presented by the author in an on-demand online format for the SAE Thermal Management Systems Symposium on October 12-14, 2021. All figures contained in this paper are from the TMSS presentation, material which SAE holds the copyrights. Additionally, passages from SAE J3112 and J3174 are used in this paper, which is also SAE copyrighted material. Finally, any passages from the U.S. Government Code of Federal Regulations (CFR) included in this paper is public domain material.
Computing Complexity Reduction for Predictive Control of Engine Thermal Management System
Authors: Chen Yue-Ming , Holmer Justin , Lee Jason , Ha Jinho
Published: March 2022

This paper presents the design, implementation, and performance evaluation of a reduced complexity algorithm for a predictive control which is based on our previously published SAE paper (2021-01-0225) titled, “Model Predictive Control for Engine Thermal Management System.” That paper presented a model predictive control (MPC) design concept and demonstrated energy efficiency improvements by enabling engine pre-cooling based on GPS/Navigation data to recognize future vehicle speed limit and road grade in anticipation of high engine load demand.

When compared to conventional control, the predictive control demonstrated considerable energy and fuel savings due to delayed timing of both knock mitigation and activation of radiator cooling fan during high engine load demand. However, this predictive control strategy is much more complicated due to its highly coupled nonlinear behavior. Also, in reality, the previous developed MPC strategies are limited to the computational resources in engine control units (ECU). Therefore, to address these challenges, a reduced-complexity MPC controller for the powertrain thermal system is developed in this paper where, by “reduced-complexity,” it is meant that the MPC controller achieves control objectives and to be executed on a modern ECU within a computation budget.

To maximize fuel economy, one of the key control logics in the previously published SAE paper is to use estimated radiator outlet coolant temperature as an indicator to determine when to lower the target engine coolant temperature. Since the heat transfer coefficients (HTC) of the thermal system are time varying, the computation load is high if the inputs to the plant models are physics-based. Therefore, lookup table (LUT)-based and mean value model (MVM) modeling approaches are developed and combined in order to reduce computational burden.

The complexity reduction is obtained via lookup tables and mean value models, which lightens the computational load of the algorithm with a minimal loss in precision. Experimental results showed that the proposed approach is able to deliver performance similar to originally proposed approaches. At the same time, the proposed algorithm is able to cut the computational complexity of the physics-based algorithm by an 18% factor.
3D CFD Simulation of Hydraulic Test of an Engine Coolant System
Authors: Ballani Abhishek , Bhagat Meghraj , Srinivasan Chiranth , Pasunurthi ShyamSundar , Maiti Dipak , Zhang Yi , Motin Abdul
Published: March 2022

Designing an efficient vehicle coolant system depends on meeting target coolant flow rate to different components with minimum energy consumption by coolant pump. The flow resistance across different components and hoses dictates the flow supplied to that branch which can affect the effectiveness of the coolant system. Hydraulic tests are conducted to understand the system design for component flow delivery and pressure drops and assess necessary changes to better distribute the coolant flow from the pump. The current study highlights the ability of a complete 3D Computational Fluid Dynamics (CFD) simulation to effectively mimic a hydraulic test. The coolant circuit modeled in this simulation consists of an engine water-jacket, a thermostat valve, bypass valve, a coolant pump, a radiator, and flow path to certain auxiliary components like turbo charger, rear transmission oil cooler etc. A commercial CFD software, Simerics-MP+®, is used to simulate the hydraulic test for two different positions of the poppet valve of the thermostat, viz. a closed position and an 50% opening, at different speeds of the engine. In the CFD model, the complete geometrical details of water-jacket, thermostat, and pump are considered. The remaining components are approximated as pipes with flow resistance models to account for flow and pressure drop at different engine speeds. Firstly, the standalone pump performance is validated in the operating regime of interest, followed by the calibration of the resistance models for the simplified components. At the end, complete system level 3D simulations are conducted and validated for the above mentioned two positions of the poppet valve. The flow distribution and pressure drop across different components show good comparison with the hydraulic test data within 7% error band.
Development of a Transmission-Illumination-Based Crack Detection Method Using Translucent Tools for Testing of Thin-Walled Metal Sheets and Foils
Authors: Staupendahl Daniel , Schneider Jan-Luca , Wahlers Ludger
Published: March 2022

In sheet metal testing, in-situ crack detection is either performed manually by purely visual inspection by the machine operator or automatically by a crack detection system. The automatic crack detection method, commonly integrated in sheet metal testing machines, evaluates the drawing force during forming. However, friction, vibration, and machine noise prevent reliable crack detection in thin sheets and foils. The same disturbance variables also prevent robust crack identification in thin sheets and foils by systems that analyze structure-borne sound. Crack detection systems that use reflected light methods, on the other hand, necessitate homogeneous illumination and are interfered by highly reflective as well as inhomogeneous sheet surfaces. In order to avoid the above-mentioned disadvantages of the currently existing crack detection methods, a procedure based on transmission-illumination was developed. Fundamental to this new development is the use of a translucent punch, which incorporates a light source and a camera connected to an image-processing unit. Building up on previous research performed with a 3D printed punch made from PVB, a punch made from alumina-based ceramics is investigated. The detection process works as follows: the translucent punch draws the sheet. As soon as a crack is formed, light penetrates the fracture and falls onto the image sensor of the camera. The image-processing unit detects the jump in illumination and triggers the immediate stop of the forming process. Forming tests were conducted to confirm the stable and operator independent performance of the newly developed detection process and the toughness of the translucent alumina-based ceramics punch.
Improving Keyhole Stability during Laser Welding of AA5xxx Alloys
Authors: Clarke Jo Ann M. , Hetrick Elizabeth T.
Published: March 2022

Laser welding of the magnesium-bearing AA5xxx aluminum alloys is often beset by keyhole instability, especially in the lap through joint configuration. This phenomenon is characterized by periodic collapse of the keyhole leaving large voids in the weld zone. In addition, the top surface can exhibit undercut and roughness. In full penetration welds, keyhole instability can also produce a spikey root and severe top surface concavity. These discontinuities could prevent a weld from achieving engineering specification compliance, pose a craftsmanship concern, or reduce the strength and fatigue performance of the weld. In the case of a full penetration weld, a spikey root could compromise part fit-up and corrosion protection, or damage adjacent sheet metal, wiring, interior components, or trim.

Previous work at Ford Research and Advanced Engineering evaluated the potential of a number of factors and techniques to improve keyhole stability in laser welding AA5xxx alloys without filler wire, including penetration, travel speed, laser beam inclination angle in the direction of travel, shield gas composition and delivery method, beam diameter, and beam oscillation frequency.[1] It was found that higher travel speeds improved keyhole stability and thereby weld strength.

The objective of the present investigation was to evaluate the effect of travel speed on keyhole stability during laser welding of AA5xxx alloys with filler wire in lap through joint configuration. The investigation found that higher travel speeds reduce voids and other concomitant keyhole instability discontinuities, thereby increasing weld strength.
Padded Self-Piercing Riveting (P-SPR) on Magnesium High Pressure Die Casting
Authors: Liu Yuchao , Wang Gerry , Weiler Jonathan
Published: March 2022

Padded self-piercing riveting (P-SPR) is a newly developed multi-material joining technology to enable less ductile materials to be joined by self-piercing riveting (SPR) without cracking. A deformable and disposable pad was employed to reduce the stress distribution on the bottom surface by supporting the whole bottom sheet continuously during rivet setting process. To verify the P-SPR process, 2.0mm thick 6061-T6 wrought aluminum was joined with 3.2mm thick coated AM60B magnesium high pressure die casting (HPDC) by using 1.0mm thick dual-phase 600 (DP600) steel as the pad. Regular SPR processes with 2 different die geometries were studied as a comparison. Compared to the regular SPR processes, P-SPR demonstrated advantages on coating protection, crack mitigation and joint strength.
Modeling Method of Dynamic Characteristics of Hydraulic Damping Rubber Isolator
Authors: Jiang Jian , Yin Zhihong , Li Ruilong , Zhen Ran , Shangguan Wenbin
Published: March 2022

The dynamic characteristics of hydraulic damping rubber isolators (such as hydraulic bushing and hydraulic mount) are related to excitation amplitude and frequency. Based on the lumped parameter model of hydraulic damping rubber isolator, a unified linear model of complex stiffness is derived and its deficiency is pointed out. Based on the derived linear model, this paper considers the nonlinear damping of inertia channel and the nonlinear stiffness of the upper chamber of the hydraulic damping rubber isolator, so as to establish a new nonlinear model, which can reflect the amplitude and frequency dependence of the dynamic characteristics of the hydraulic damping rubber isolator. Finally, the nonlinear model is used to analyze the dynamic response of hydraulic damping rubber isolator under harmonic excitation and random excitation respectively, and the results are compared with the test results. The results show that the proposed model can characterize the amplitude and frequency dependence of the dynamic characteristics of the hydraulic damping rubber isolator, and can accurately calculate the dynamic response of the hydraulic damping rubber isolator under harmonic excitation and random excitation.
Vibration Analysis and Optimization of Rock Drilling Arm
Authors: Yue Kai , Liu Feixiang , Liao Jinjun , Wang Yongsheng , Wu Jinglai , Zhang Yunqing
Published: March 2022

When the drill arm reaches the specified position, the rubber top disk of the propelling beam is pressed against the rock surface by the hydraulic cylinder force and the rock drill starts drilling. Because of the reaction force and the deformation of the drill arm, the propelling beam will be offset from its target position and vibrate, which will affect the drilling accuracy. To analyze the vibration of the propelling beam, the rigid-flexible coupled model is established. The minimum displacement offset of the propelling beam from the initial position is used as the optimization function and the parameters of the rubber top disk are used as optimization variables. The amplitude of the propelling beam at a steady state is used as the constraint. From the simulation results, the rigid-flexible coupled model can describe the vibration of the propelling beam better than the rigid model, especially during the rock drill working stage. After optimization, the offset value of the propelling beam is reduced, and the vibration amplitude at a steady state is also in a small range.
A Neural Network NARMA-L2 Tracking Control for Electronic Throttle System*
Authors: Al-Assadi Salem
Published: March 2022

In this paper, the Artificial Neural Network (ANN) control strategy based on the Nonlinear Auto Regressive Moving Average-Level 2 (NARMA-L2) technique has been used for tracking control of an electronic throttle body. The NARMA-L2 nonlinear plant model is first identified offline by training using a set of input-output data pairs measured at different operating conditions. This data was collected from an actual operation of the throttle body running in a closed-loop control system on a prototype vehicle. The identified NARMA-L2 plant model was then inverted and used to force the throttle output position to approximately track any reference inputs with multiple set-point changes at different operating conditions. The NARMA-L2 model was reconfigured to be an equivalent model of a feed-forward controller that can cancel not only the actual dynamic behavior of the throttle body but also the nonlinearity effects. This type of controller has great potential to overcome the difficulty of developing an inverse dynamic model of the throttle body [1] and has the ability to compensate any un-modeled nonlinear dynamic changes that may be excited due to environmental changes. These changes can include load, temperature, humidity, and external disturbances with noise effects that may be introduced into the closed-loop control of the throttle body during real time operation in the vehicle. The resulting closed loop control system used the NARMA-L2 architecture that have a multilayer perceptron neural network structure with the dynamic back-propagation algorithm becomes an implicit algebraic model that perfectly tracks any multiple set-point changes at different operating conditions. Testing results from real time implementation are provided to illustrate the new controller performance for tracking controls during actual operation on a prototype vehicle. The identified NARMA-L2 neuro-controller shows more robustness and better performs as compared to other controllers developed in previous work [1-3].

* This work was done while the author was at IAV Automotive Engineering Inc, 15620 Technology Drive, Northville, MI 48168.

† Currently working with MAHLE Powertrain LLC, 14900 GalleonCourt, Plymouth, MI 48170.
A Comparative Study of Lithium-Ion Cathode Chemistry Correlations with Emissions Initiated by Nail Penetration Abuse in the Presence of an Immersive Coolant
Authors: Surampudi Bapiraju , Jones Kevin , Shuvodeep Bhattacharyya Bhattacharyya
Published: March 2022

Internal short-circuit in cells/batteries is a phenomenon where there is direct electrical contact between the positive and negative electrodes leading to thermal runaway. The nail penetration tests were used to simulate an internal short circuit within the battery, where a conductive nail was used to pierce the battery cell separator membrane which provided direct electrical contact between the positive and negative electrodes. The batteries tested during this work were common batteries used in existing automotive applications, and they included a nickel manganese cobalt (NMC) battery from a Chevrolet Bolt, a lithium manganese oxide (LMO) battery from a Chevrolet Volt, and a lithium iron phosphate (LFP) battery in a hybrid transit bus. The battery abuse and emissions tests were designed to intentionally drive the three different battery chemistries into thermal runaway while measuring battery temperatures, battery voltages and gaseous emissions. During this testing, the batteries were submerged in an immersive coolant, NOVEC 7300, in order to judge how effective, the immersive coolant was in preventing additional thermal propagation. The emissions data collected from FTIR (Fourier Transform Infrared Spectroscopy), GC-FID (Gas Chromatography and Flame Ionization Detection) and AES (Atomic Emission Spectroscopy) are reported in appropriate units flagging any transgression of health-related safety limits. The emissions collected during the nail penetration testing are summarized in tabular and graphic formats. The NMC showed a higher thermal runaway intensity; it was the only chemistry that continued to have thermal propagation after the initial nail penetration and it had marginally higher temperatures recorded. In contrast, the LFP produced the least number of harmful emissions while the LMO recorded the lowest temperatures.
Proposed Standards and Methods for Leak Testing Lithium-Ion Battery Packs Using Glycol-Based Coolant with Empirically Derived Rejection Limits
Authors: Blaufuß Marc , Wetzig Daniel
Published: March 2022

Lithium-ion battery systems are an energy source for a variety of electric-vehicle applications due to their high energy density and low discharge rates. Battery packs, whether made of prismatic, cylindrical or pouch cells, are cooled by common automotive thermal management systems. The rapid detection of battery pack coolant-system leaks during production operations is essential for meeting necessary safety and service-life requirements. Industry standards for measuring leak rates for both glycol-based and refrigerant-based cooling systems, however, currently do not exist. This presentation will discuss how leaks in water-glycol cooling circuits can be detected reliably and quantitatively through detection of escaping test gas as an indicator of ethylene glycol leaks and how the test gas leak rates correlate to the liquid leakage of the cooling liquid. Influencing variables such as leakage channel diameter, pressure difference and viscosity are considered, and go/no-go leak rates are described.
Prediction of Crash Performance of Adhesively-Bonded Vehicle Front Rails
Authors: Ramachandra Sanketh , Deb Anindya , Chou Clifford
Published: March 2022

Adhesive bonding provides a versatile strategy for joining metallic as well as non-metallic substrates, and also offers the functionality for joining dissimilar materials. In the design of unibody vehicles for NVH (Noise, Vibration and Harshness) performance, adhesive bonding of sheet metal parts along flanges can provide enhanced stiffening of body-in-white (BIW) leading to superior vibration resistance at low frequencies and improved acoustics due to sealing of openings between flanges. However, due to the brittle nature of adhesives, they remain susceptible to failure under impact loading conditions. The viability of structural adhesives as a sole or predominant mode of joining stamped sheet metal panels into closed hollow sections such as hat-sections thus remains suspect and requires further investigation. As modern vehicle design is primarily driven by CAE (Computer-Aided Engineering), it is important to ensure that the experimental behaviors of adhesively-bonded components can be satisfactorily predicted. With the stated issues in mind i.e. gathering insight into the performance of adhesively-bonded steel hat-section components under impact loading and simulation of its behavior using an explicit FEA code such as LS-DYNA, a systematic experimental and numerical study is carried out comprising: (a) testing of single lap shear joints in a UTM and prediction of the average mechanical behavior of the joints till failure using a cohesive zone material modeling approach for the adhesive with independent Mode I and Mode II fracture criteria; (b) axial impact testing of double-hat section components with conventional spot welds, the same components with purely adhesively-bonded flanges in lieu of spot welds, and hybrid components with adhesive-bonding as well as sparse spot welds, and prediction of the detailed impact responses of the components mentioned; and (c) finally, implementation of the adhesive-based joining strategies in front rails of a validated finite element model of a commercially produced unibody passenger car and assessment of its performance vis-à-vis the baseline vehicle in full frontal NCAP test mode against a rigid barrier.
Conference of the States Parties to the United Nations Convention against Corruption: Opportunities for International Cooperation and Results of Activities
Authors: Kovtun E. A.
Published: March 2022

The format of international cooperation of the Conference of the Countries Participating in the UN Convention against Corruption, on the one hand, continues the traditions of international intergovernmental organizations, and on the other hand, represents a new format of interaction between states in the fi eld of anti-corruption activities, which has distinctive features. The Conference has a pivotal role in international cooperation on the prevention and combating of corruption due to the wide area of activities and the number of participants. The purpose of this paper is to analyze the features of the functioning of the Conference of the Countries Participating in the UN Convention against Corruption and the results of its activities since 2006. Using the analysis of documents and scientifi c publications, the author concludes that despite the importance of the Conference as a platform for multilateral dialogue, the countries participating in the United Nations Convention against Corruption failed to achieve signifi cant progress in the declared areas of activity. The author highlights the main diffi culties faced by states in implementing anti-corruption measures based on the norms of international law.
Verkörperung des Politischen
Authors: Hänel Jonas
Published: March 2022

Was hat politische Bildung überhaupt mit Körperlichkeit zu tun? Diese politikdidaktische Untersuchung beschäftigt sich mit der Frage welche Rolle der Körper hinsichtlich der Darstellung und Wahrnehmung des Politischen spielt und welche Implikationen sich daraus für politische Bildungsprozesse ergeben. Die Rezeption der pragmatischen Philosophie der Somästhetik (Richard Shusterman) dient als Heuristik, um somästhetische Perspektiven im Kontext verschiedener Handlungsfelder politischer Bildung herauszuarbeiten.
Inklusiven Geschichtsunterricht planen
Authors: Barsch Sebastian
Published: March 2022

Inklusion bringt neue Herausforderungen für die Planung von Geschichtsunterricht mit sich. Die zunehmende Heterogenität der Schülerschaft fordert auch von Geschichtslehrkräften neue Wege der Differenzierung und Subjektorientierung. Für diese Herausforderungen trägt der Band Ideen und Praxisbeispiele zusammen, um Lehrerinnen und Lehrern Orientierung bei der Konzeption von Geschichtsunterricht in inklusiven Klassen zu geben.
Schwerpunkte sind Diagnostik und individuelle Förderplanung. Darüber hinaus werden allgemeine Prinzipien inklusiven Unterrichts wie das Universal Design of Learning,Sprachsensibilität und ästhetische Zugänge zum historischen Lernen vorgestellt. Der Band ist nicht allein auf den inklusiven Unterricht bei Kindern und Jugendlichen mitsonderpädagogischem Förderbedarf ausgerichtet. Vielmehr basiert er auf einem breiten Verständnis von Inklusion, welche die schulische Vielfalt in ihrer Gesamtheit in denBlick nimmt.
Der 8. Mai 1945 in den Reden deutscher Bundespräsidenten, nur Buch
Authors: Huneke Friedrich
Published: March 2022

Der Geschichtsunterricht muss Schülern fachliche, ästhetische und politische Kompetenzen vermitteln, damit sie an der Traditionsbildung ihrer Gesellschaft kritisch reflektierend mitwir-ken können.
Die Unterrichtsreihe thematisiert den 8. Mai 1945 im Wandel der Geschichtskultur: Mit dem Generationswechsel geht das erlebte Gedächtnis über in vermittelte Formen der Erinnerungs-kultur. Schüler erarbeiten Familienerinnerungen und Kernaussagen vom Vieraugengespräch Heuss – Adenauer 1955 bis zu den wegweisenden Reden von Bundespräsidenten zum 8. Mai 1945.
Währungs- und Wirtschaftskrisen in der Weimarer Republik
Authors: Nieß Ottmar
Published: March 2022

Zum Heft Die Inflation des Jahres 1923 und die 1929 hereinbrechende Wirtschaftskrise waren zwei der maßgeblichen Schlüsselprobleme der Weimarer Republik. Zugleich zeigt sich an ihnen, wie wirtschaftliche Entwicklungen, soziale Probleme und politische Lösungsversuche miteinander verknüpft sind. Otmar Nieß legt mit diesem Heft ein Unterrichtsvorhaben vor, welches diese Zusammenhänge für den Geschichtsunterricht erschließt. Nicht zuletzt hat das Thema angesichts der gegenwärtigen Finanz- und Wirtschaftskrise einen deutlichen Gegenwartsbezug. Der Unterrichtsvorschlag folgt dabei den Prinzipien historischer Projektarbeit. Anhand zahlreicher für die Gruppenarbeit gestalteter Arbeitsaufträge und Unterrichtsmaterialien wird die Erschließung des Themas als binnendifferenziertes und individualisiertes Lernen ermöglicht. Zur Reihe Die Reihe „Geschichtsunterricht praktisch“ bietet neue didaktisch-methodische Zugriffe zu bekannten Themen und erschließt gleichzeitig wenig bekannte Quellen zu aktuellen Fragestellungen. Die einzelnen Hefte bieten neben einer kurzen Einführung in das jeweilige Thema Quellen und Darstellungen mit kompetenzorientierten Aufgabenstellungen für einen differenzierenden Geschichtsunterricht. Hinzu kommen Vorschläge für Tafelbilder, Tests und Klausuren, Arbeitsmaterialien sowie weiterführende Literaturhinweise. Die Kopiervorlagen sollen der raschen und unkomplizierten Vorbereitung und dem direkten Einsatz in einem Unterricht dienen.
Gender in der Sozialen Arbeit
Authors: Ehlert Gudrun
Published: March 2022

Worüber wird eigentlich gesprochen wird, wenn von „Geschlecht“ oder „Gender“ die Rede ist? In diesem Buch werden theoretische Grundlagen zur Kategorie Geschlecht aus der Frauen- und Geschlechterforschung erläutert und der Bedeutung von Geschlecht für die Soziale Arbeit nachgegangen. Dazu gehören auch eine Bestandsaufnahme von Sozialer Arbeit als Profession im Kontext von Geschlechterhierarchien und –differenzen, eine Reflexion geschlechterbewusster Sozialer Arbeit und des Gender Mainstreamings sowie der Verankerung von Geschlechterperspektiven in der Sozialen Arbeit.