bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improvement of weld quality in electromagnetic welding of aluminum‐stainless steel sheets
Authors: Khandaei M. , Vahidshad Y. , Ayaz M. 
Published: October 2020

AbstractIn this paper, the electromagnetic welding of two dissimilar metals was simulated using LS‐Dyna software. Results of finite element simulations were used to obtain a high quality weld between the aluminum and stainless steel by the minimum discharge energy. The experiments were designed according to a Box‐Behnken response surface methodology to extract the regression models from the significant parameters of voltage, standoff distance and thickness of driver. Possibility of weld formation were predicted by using the weldability window of aluminum‐stainless steel. According to the results of analysis of variance, the quality of weld can be improved by applying the following values of parameters: voltage of 15 kV, standoff distance of 1.5 mm and driver thickness of 1 mm. The results of the finite element simulations were confirmed by conducting the electromagnetic welding at the optimal condition of parameters. In order to evaluate the quality of joints, the microstructure of weld interface was studied using the optical and scanning electron microscope.
Effects of various tool plunge depths on microstructure evolution, mechanical properties and dome structure features of friction stir spot welded AA5052‐H32 similar joints
Authors: Bozkurt M. , Öztoprak N. , Sayer S. , Yeni Ç. 
Published: October 2020

AbstractThe solid‐state nature of friction stir spot welding process provides outstanding advantages for the sound joining of aluminum alloys. Within this study, 3 mm‐thick AA5052‐H32 sheets are successfully joined by friction stir spot welding using 2344 hot‐worked steel pin to investigate the effects of various tool plunge depths on the microstructure, mechanical and metallurgical properties of similar welds. Therefore, the experiments are performed at different plunge depths in the range of 3 mm–4 mm. Accordingly, the relationships between the process parameter (tool plunge depth) and the responses (microstructure, dome structure, microhardness and lap shear tensile load) are established. Microstructure analyses demonstrate that the increase in the plunge depth leads to more grain refinement within the stir zone, which significantly affects the mechanical performance of the similar joints. This study also indicates that the tool plunge depth in friction stir spot welding process has a noteworthy influence on the characteristic features of the 5052 aluminum alloy joints, such as the dome structure. Moreover, an explicit increase in the microhardness towards the weld stir zone is observed in all specimens. It is found that the average maximum tensile‐shear force enhances with the increment in the tool plunge depth from 3 mm to 4 mm.
Effect of cut‐outs shape and position on the axial compression behavior of aluminum thin‐walled structures
Authors: Wang G. , Li W. , Xue L. , Kou L. , Zhu X. , Xu Y. 
Published: October 2020

AbstractThe effect of cut‐outs positions and shapes on deformation behaviors and energy absorption of automobile thin‐walled structures is researched by quasi‐static axial compression, using MTS machine and digital image correlation method. The accuracy of finite element modeling is verified by axial compression test. The relationship between variation characteristics of different time and sections and deformation of the sample is analyzed. The results show that the number of surface deformation concentrated areas is affected by position of circular cut‐outs. Peak load of sample could be effectively reduced by slotted‐shaped cut‐outs. The energy absorption of slotted‐shaped cut‐outs with different aspect ratios and directions is different, horizontally‐long‐slotted cut‐outs is increased by 5.13 %. The position of deformation concentration region is affected by compression half‐wavelength. Deformation concentration region of sample less than half‐wavelength is below cut‐outs. By digital image correlation method, strain of horizontally‐long‐slotted cut‐outs is more concentrated. Peak load is effectively reduced. The results of finite element analysis show that when the thin‐walled structure is bulking, the section of sample is deformed from top to bottom. The initial area of cross‐section at center of cut‐outs is linear with peak load. These achievements may serve as guideline for enhancing compression performance of thin‐walled structures.
Effect of erbium on microstructure and mechanical properties of Al‐Si‐Mg‐Cu alloy
Authors: Lei X. , Zhang Z. , Dong H. , Wang C. , Du X. 
Published: October 2020

AbstractThe effect of erbium addition at different ratios (0.2 wt.%, 0.4 wt.%, 0.6 wt.%) on microstructure evolution and mechanical properties of the Al−Si‐Mg−Cu alloy have been investigated. The results show that adding erbium can refine the primary α‐aluminum grains in the as‐cast alloys to a diverse extent. In addition, the coarse and long plate‐like eutectic silicon can be modified into a fine short rod‐like structure, and the distribution of eutectic silicon can be optimized. During the solidification of the alloy, erbium and other elements will form primary erbium‐rich precipitates of different sizes and shapes, including primary erbium‐silicon‐rich and erbium‐copper‐silicon‐rich precipitates, which can change the distribution of solute atoms and promote the evolution of microstructure. But the coarse primary precipitates will embrittle the alloys and consume more solute atoms (erbium, copper, magnesium), having a certain inhibitory effect. After heat treatment, the solid solution decomposes to form secondary Al3Er precipitates, which further strengthens the alloy. In particular, the alloy with the highest erbium content shows the best comprehensive tensile properties at as‐cast and heat‐treatment conditions.
Raman spectra‐based deep learning: A tool to identify microbial contamination
Authors: Maruthamuthu Murali K. , Raffiee Amir Hossein , De Oliveira Denilson Mendes , Ardekani Arezoo M. , Verma Mohit S. 
Published: October 2020

AbstractDeep learning has the potential to enhance the output of in‐line, on‐line, and at‐line instrumentation used for process analytical technology in the pharmaceutical industry. Here, we used Raman spectroscopy‐based deep learning strategies to develop a tool for detecting microbial contamination. We built a Raman dataset for microorganisms that are common contaminants in the pharmaceutical industry for Chinese Hamster Ovary (CHO) cells, which are often used in the production of biologics. Using a convolution neural network (CNN), we classified the different samples comprising individual microbes and microbes mixed with CHO cells with an accuracy of 95%–100%. The set of 12 microbes spans across Gram‐positive and Gram‐negative bacteria as well as fungi. We also created an attention map for different microbes and CHO cells to highlight which segments of the Raman spectra contribute the most to help discriminate between different species. This dataset and algorithm provide a route for implementing Raman spectroscopy for detecting microbial contamination in the pharmaceutical industry.
Single‐institutional reference values for concentric needle jitter analysis using the extrapolated reference values procedure: Comparison to published reference values
Authors: Lee Ikjae , Sanders Donald B. , Nandedkar Sanjeev D. , Kazamel Mohamed 
Published: October 2020

AbstractBackgroundThe extrapolated reference values procedure (E‐Ref) was used to compare data from a single institution with the recently published reference value (RV) for concentric electrode jitter.MethodsData from voluntarily activated concentric needle jitter studies in the frontalis muscle were obtained using retrospective chart review. All measured signals were reviewed for acceptable quality. Cutoff values for increased jitter were calculated using E‐Ref, and compared with the published RVs.ResultsAt total of 1501 apparent single‐fiber action potential (ASFAP) pairs were reviewed; 1371 ASFAP pairs were determined to have acceptable quality. The cutoff value identified by E‐Ref from all reviewed ASFAP pairs was 36 microseconds and the cutoff for acceptable pairs was 35 microseconds. Using either of these cutoff values (36 or 35 microseconds) did not result in a significant difference in percentage of jitter recordings considered normal when compared with the recently published RV (38 microseconds).DiscussionThe single‐institution jitter cutoff value obtained by E‐Ref gives results that are not significantly different from the reported RV.
Predicting myofiber cross‐sectional area and triglyceride content with electrical impedance myography: A study in db/db mice
Authors: Pandeya Sarbesh R. , Nagy Janice A. , Riveros Daniela , Semple Carson , Taylor Rebecca S. , Mortreux Marie , Sanchez Benjamin , Kapur Kush , Rutkove Seward B. 
Published: October 2020

AbstractBackgroundElectrical impedance myography (EIM) provides insight into muscle composition and structure. We sought to evaluate its use in a mouse obesity model characterized by myofiber atrophy.MethodsWe applied a prediction algorithm, ie, the least absolute shrinkage and selection operator (LASSO), to surface, needle array, and ex vivo EIM data from db/db and wild‐type mice and assessed myofiber cross‐sectional area (CSA) histologically and triglyceride (TG) content biochemically.ResultsEIM data from all three modalities provided acceptable predictions of myofiber CSA with average root mean square error (RMSE) of 15% in CSA (ie, ±209 μm2for a mean CSA of 1439 μm2) and TG content with RMSE of 30% in TG content (ie, ±7.3 nmol TG/mg muscle for a mean TG content of 25.4 nmol TG/mg muscle).ConclusionsEIM combined with a predictive algorithm provides reasonable estimates of myofiber CSA and TG content without the need for biopsy.
Cine magnetic resonance imaging provides novel predictors of early continence recovery after radical prostatectomy: Assessment of the dynamics of pelvic floor muscles
Authors: Shimura Hiroshi , Kuwahara Yoshitaka , Aikawa Junki , Watanabe Nozomu , Nakamura Kenzo , Tsukamoto Takuji , Terada Shigehiko , Mitsui Takahiko , Takeda Masayuki 
Published: October 2020

AbstractAimsPostprostatectomy incontinence is a major complication of prostatectomy. Although pelvic floor muscle training can successfully treat postprostatectomy incontinence, evidence for how muscle movement affects continence recovery is lacking. We evaluated dynamic factors of prostatectomy patients using cine magnetic resonance imaging to identify risk factors for postprostatectomy incontinence and reveal the contribution of pelvic floor muscles to continence recovery.MethodsA total of 128 prostate cancer patients who underwent robot‐assisted laparoscopic surgery were enrolled. Cine magnetic resonance imaging was performed preoperatively and 6 months after surgery. Continence was defined as pad‐free or use of safety pads. We defined the bladder neck elevation distance during pelvic floor muscle training as the bladder elevation distance. Patients with continence recovery within 1 month comprised the continence group (n = 48); other patients comprised the incontinence group (n = 80).ResultsThe preoperative bladder elevation distance was significantly longer in the continence group than in the incontinence group (10.4 vs. 8.2 mm; p < .001). The postoperative bladder elevation distance of the continence group tended to be longer (9.9 vs. 8.9 mm; p = .057). Multivariate analysis showed that the preoperative bladder elevation distance significantly contributed to continence recovery (p = .016). Patients with a longer preoperative bladder elevation distance (>8.5 mm) experienced continence recovery significantly faster than patients with a shorter distance (<8.5mm) (p = .038).ConclusionsBladder elevation distance, a novel dynamic parameter, was strongly associated with early continence recovery. Cine magnetic resonance imaging can assess a patient's risk of postprostatectomy incontinence and guide pelvic floor muscle training.
New results concerning to approximate controllability of Hilfer fractional neutral stochastic delay integro‐differential systems
Authors: Dineshkumar C. , Udhayakumar R. 
Published: October 2020

AbstractThis manuscript is mainly focusing on the approximate controllability of Hilfer fractional neutral stochastic integro‐differential equation with infinite delay. We study our primary outcomes by utilizing the theoretical concepts related to the fractional calculus and Krasnoselskii's fixed point theorem. First, we prove the approximate controllability of the fractional evolution system. Then, we extend our results to the concept of nonlocal conditions. Last, we provide a theoretical application to assist in the effectiveness of the discussion.
Use of non‐vitamin K antagonist oral anticoagulants in Colombia: A descriptive study using a national administrative healthcare database
Authors: Machado‐Alba Jorge E. , Gaviria‐Mendoza Andrés , Machado‐Duque Manuel E. , Tovar‐Yepes Carlos , Ruigómez Ana , García Rodríguez Luis Alberto 
Published: October 2020

AbstractPurposeWe aimed to describe time‐trends in the use of NOACs among a group of ambulatory patients with nonvalvular atrial fibrillation (NVAF) in Colombia and to describe treatment patterns and user characteristics.MethodsUsing the Audifarma S.A administrative healthcare database in Colombia, we identified 10 528 patients with NVAF aged at least 18 years between July 2009 and June 2017 with a first prescription (index date) for apixaban, dabigatran or rivaroxaban (index NOAC) and followed them for at least year (max, 8.0 years, mean 2.2 years). We described patient characteristics, NOAC use over time, and the dose of the first NOAC prescription.ResultsA total of 2153 (20.5%) patients started on apixaban, 3089 (29.3%) on dabigatran and 5286 (50.2%) on rivaroxaban. The incidence of new users of apixaban and rivaroxaban increased over study years while for dabigatran it decreased. Mean age at the index date was: 78.5 years (apixaban), 76.5 years (dabigatran), 76.0 years (rivaroxaban). The percentage of patients started NOAC therapy on the standard dose was: apixaban 38.0%, dabigatran 30.9%, rivaroxaban 56.9%. The percentage still prescribed their index NOAC at 6 months was apixaban 44.6%, dabigatran 51.4%, rivaroxaban 52.7%. Hypertension was the most common comorbidity (>80% in each NOAC cohort).ConclusionDuring the last decade, the incidence of NOAC use in patients with NVAF affiliated with a private healthcare regime in Colombia has markedly increased. Future studies should evaluate whether the large number of patients with NVAF starting NOAC treatment on a reduced dose are done so appropriately.
Evaluation of the DC bus link capacitors and power transistor modules in the qualification testing of PV inverters
Authors: Hacke Peter , Clemens Daniel , Thiagarajan Ramanathan , Flicker Jack , Igarashi Hironobu 
Published: October 2020

AbstractTo achieve useful, fair, and cost‐effective design qualification and type approval testing for PV inverters, two procedures were developed and demonstrated to evaluate the bus link capacitors and power transistor—and where applicable, its module—for long‐term reliability. We evaluate the inverter under simulated use conditions with heat run tests to find the highest operating temperatures reached by these components. The procedures are demonstrated in this study with a 4‐kVA class string inverter. The maximum temperature of the DC bus link capacitors was determined to be 76.4°C when the ambient temperature was at the inverter's maximum rated temperature of 60°C with derating occurring. On the other hand, the power transistor module's maximum temperature using the heat sink temperature as the index, 92.6°C, occurred in an ambient of 40.8°C when derating was not occurring. The conditions found for upper temperatures exhibited by these components are, respectively, proposed for implementation in the dry heat and thermal cycling tests in the IEC 62093 “Power conversion equipment for photovoltaic systems – Design qualification testing” international standard draft so that the levels applied in the tests are in proportion to those experienced in the field. As a result, fairer evaluation of inverter reliability is realized.
On the catastrophic explosion of the AZF plant in Toulouse
Authors: Guiochon Georges 
Published: October 2020

AbstractOn September 21, 2001, around 10:17 am, a warehouse containing about 300 metric tons of ammonium nitrate rejects exploded in the AZF/Grande Paroisse plant in Toulouse (France), causing 31 deaths, hundreds of casualties, and enormous damages. The criminal investigation focused exclusively on the explosion itself and neglected the long chain of precursor events that took place in the previous hours, and suggest that a complex cascade of successive events was triggered by some unknown event. These strange, unusual phenomena were never investigated. The prosecution adopted an unlikely chemical scenario that cannot explain the origin of the catastrophe. The official investigation and the first instance trial were inconclusive. The judge found insufficient ground for criminal liability. A detailed examination of the different precursor events suggests a tentative explanation for the succession of events that linked to lead to the catastrophe. A strong thermal inversion caused pollutants from local plants to affect a high voltage electric line downwind from the plants, generating strong flames and arcs without triggering the current breakers and perturbing the computers that control the plants. Rogue orders caused a chain of explosions in the neighbor SNPE plant and finally that of a WW II bomb under AZF.
Assessing goodness‐of‐fit for evaluation of dose‐proportionality
Authors: Wolfsegger Martin J. , Bauer Alexander , Labes Detlew , Schütz Helmut , Vonk Richardus , Lang Benjamin , Lehr Stephan , Jaki Thomas F. , Engl Werner , Hale Michael D. 
Published: October 2020

SUMMARYFor the clinical development of a new drug, the determination of dose‐proportionality is an essential part of the pharmacokinetic evaluations, which may provide early indications of non‐linear pharmacokinetics and may help to identify sub‐populations with divergent clearances. Prior to making any conclusions regarding dose‐proportionality, the goodness‐of‐fit of the model must be assessed to evaluate the model performance. We propose the use of simulation‐based visual predictive checks to improve the validity of dose‐proportionality conclusions for complex designs. We provide an illustrative example and include a table to facilitate review by regulatory authorities.
Matrix‐assisted laser desorption/ionization mass spectrometry biotyping, an approach for deciphering and assessing the identity of the honeybee pathogen Nosema
Authors: Houdelet Camille , Bocquet Michel , Bulet Philippe 
Published: October 2020

RationaleThe microsporidia are obligate intracellular pathogenic fungi that parasitize a wide range of invertebrate and vertebrate hosts and have important impacts on health, food security and the economy. In this paper, we focus on Nosema ceranae and N. apis, which chronically infect the digestive tract of honeybees, altering their physiology and lifespan.MethodsWe applied matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) for rapid molecular profiling of extracts of Nosema spores in order to identify the species and the geographical origin, and assess the viability status of Nosema microsporidia in conjunction with a flow cytometric approach. Pure solutions of spores were prepared for flow cytometric analysis and MALDI‐MS profiling. A mechanical extraction of viable or heat‐killed Nosema spores was conducted to obtain mass fingerprints of peptides/proteins for samples of microsporidia from different geographical origins (MBO.NC01, MBO.NC02 and MBO.NA01).ResultsA distinction in the peptide/protein profiles between two isolates with different geographical origins was observed. Mass fingerprints of viable and experimentally killed spores were also clearly distinguishable, regardless of Nosema species. Finally, using our computational models on the different Nosema species, we were able to classify five independent isolates of Nosema microsporidia.ConclusionsWe have shown that MALDI‐MS is a rapid, cost‐effective and simple method for identifying Nosema species. We demonstrated that MALDI Biotyping could represent a valuable surveillance tool of nosemosis in apiaries for sanitary services and beekeepers.
Adaptive active disturbance rejection control guaranteeing uniformly ultimate boundedness and simplicity
Authors: Nie Zhuo‐Yun , Zhang Bing , Wang Qing‐Guo , Liu Rui‐Juan , Luo Ji‐Liang 
Published: October 2020

SummaryThe active disturbance rejection control (ADRC) scheme requires a high bandwidth in the extended state observer (ESO), causing heavy noise pollution in the control system. This article develops an effective and simple adaptive ADRC scheme to realize high performance control when ESO bandwidth is limited. The adaptative law is generated by the state tracking error such that all the feedback loops and feedforward channels are activated for active disturbance rejection. An “attached” and “quantified” adaptation is developed to guarantee the easy usage of the proposed scheme. The uniformly ultimate boundedness of all the signals in the closed‐loop system is proved in the sense of Lyapunov theory. Finally, two simulation examples are given to demonstrate the results.
Sampled‐data based resilient consensus of heterogeneous multiagent systems
Authors: Zhu Yunru , Zhou Liqi , Zheng Yuanshi , Liu Jian , Chen Shiming 
Published: October 2020

SummaryThis article studies consensus of a group of heterogeneous agents with first‐order and second‐order integrator dynamics in presence of malicious agents. We employ the algorithm where each normal agent ignores large and small relative state values of its neighbors to mitigate the effects of malicious agents. Assuming that the maximum number of malicious agents in the neighborhood of each agent is known, sufficient topological condition is obtained to guarantee resilient consensus in directed networks. The result is further extended to heterogeneous multiagent systems with bounded communication delays. Moreover, impulsive control strategy is introduced in the update schemes and sufficient condition in terms of graph robustness is provided for resilient consensus. Numerical examples are provided to illustrate the effectiveness of the theoretical results.
Sampled‐data exponential stabilization of switched nonlinear delayed systems with asynchronous switching
Authors: Huang Xia , Wang Jikai , Wang Zhen , Xia Jianwei , Shen Hao 
Published: October 2020

SummaryIn this article, the exponential stabilization for a class of switched nonlinear delayed systems is addressed via aperiodic sampled‐data control with asynchronous switching. A new type of looped multiple Lyapunov‐Krasovskii functionals (LKFs) is developed, which depend both on the system modes and on the controller modes. Moreover, the constructed looped LKFs are discontinuous and relax restrictions on positive definiteness that is only required at the sampling instants and at the switching instants of system modes. Based on the looped multiple LKFs, the average dwell time approach, and some estimation techniques, a less conservative stability criterion is derived to ensure the exponential stability of the closed‐loop system. Furthermore, by decoupling the matrix inequalities in the stability criterion, a LMI‐based design algorithm for the control gains is developed, which gets further refined and becomes more flexible due to the introduction of the two adjustable parameters. Two simulation examples are finally provided to validate the effectiveness and superiority of the proposed functionals and the obtained results over some existing ones.