检索结果-南通市图书馆

维普期刊数据库

Experimental investigation on slip conditions during thread rolling with flat dies

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第1期12卷 136-143页

作者： stefan VOLZ Peter GROCHE Institute for Production Engineering and Forming Machines Technical University DarmstadtOtto-Berndt Straße 2Darmstadt 64287Germany

The process design of flat die rolling operations can be a tedious and costly process due to the challenges posed by small process windows.Within this work,an effort is made to closely investigate and understand the process limits caused by excessive slippage of the workpiece.Optical measurements are carried out to capture the characteristics of excessive slippage and the influence of the stroke rate and the tribological system on this process limit.Large differences in slippage were observed,depending on the tribological system.While systems with polymer based lubricants showed excessive slippage at low stroke rates,systems using oil or no lubricant endured higher stroke rates before process limits were reached.The optical measurements revealed three major forms of slippage:successful rolling without slippage,failure due to excessive slippage at process start,and failure due to excessive slippage at around one workpiece rotation.

关键词： rolling incremental forming thread rolling slippage profile rolling

The big data challenge-and how polypharmacology supports the translation from pre-clinical research into clinical use against neurodegenerative diseases and beyond

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第8期19卷 1647-1648页

作者： Sven Marcel stefan Muhammad Rafehi Drug Development and Chemical Biology Lübeck Institute of Experimental Dermatology(LIED)University of Lübeck and University Medical Center Schleswig-HolsteinLübeckGermany Department of Pathology Section of NeuropathologyTranslational Neurodegeneration Research and Neuropathology LabUniversity of Oslo and Oslo University HospitalOsloNorway School of Medical Sciences Faculty of Medicine and HealthUniversity of SydneySydneyNSWAustralia Institute of Clinical Pharmacology University Medical Center GöttingenGöttingenGermany Department of Medical Education Augsburg University MedicineAugsburgGermany

Introductory comments:The identification and validation of disease-modifying proteins are fundamental aspects in drug development.However,the m ultifactority of n eurodegen era tive diseases poses a real challenge for targeted therapies.Furthermore,the behavior of individually(over-)expressed to rget proteins in vitro is likely to differ from their actual functional behavior when embedded in cascades and pathways in vivo.

关键词： translation beyond likely

维普期刊数据库

Artificial intelligence analysis of videos to augment clinical assessment:an overview

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第4期19卷 717-718页

作者： David C.Wong stefan Williams University of Leeds Leeds Teaching Hospitals Trust LeedsUK

Observation is a fundamental part of the practice of clinical medicine.Observation of movement is particularly important for the neurologist.Conditions such as Parkinson’s disease,multiple sclerosis,stroke,epilepsy,and many others affect a person’s movement in characteristic ways.In some conditions,changes in the patient’s voice can be included in this-changes in sound caused by changes in the movements of speech.The clinician’s detection of a characteristic abnormality,and their judgment of its severity,plays a central role in both diagnosis and the assessment of prognosis or response to treatment.However,that practice depends upon a limited resource of experienced experts.In addition,these experts are limited by human visual judgment,which cannot reliably or precisely detect and measure small or subtle changes in movement(Williams et al.,2023).

关键词： clinical epilepsy diagnosis

维普期刊数据库

Implementation and validation of a bonded particle model to predict rheological properties of viscoelastic materials

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第6期89卷 198-210页

作者： Michael Mascara Arno Mayrhofer stefan Radl Christoph Kloss Institute of Process and Particle Engineering Graz University of TechnologyInffeldgasse 13Graz8010Austria DCS Computing GmbH Industriezeile 35Linz4020Austria

This work focuses on implementing a particle-based method able to characterize viscoelastic materials whose rheological properties,such as storage modulus G′and loss modulus G″,are known.It is based on the bonded particle model,with the elastic constitutive relation here substituted with a viscoelastic one to capture time-scale effects.The Burgers model,vastly used in literature to model viscoelastic systems,is discretized and implemented.The test case used for calibration comprises of a cubic lattice,sheared with a periodic motion,to mimic the effect of a shear rheometer.After appropriate filtering of the stress response,the rheological properties are obtained,highlighting the effect of the lattice geometry,as well as the particle size,on the accuracy of the model.Moreover,the Burgers parameters are calibrated by analytically fitting the experimental dataset,showing the limitation of the Burgers model.The micro-contact parameters are obtained from the macro parameters through appropriate scaling.After completing a frequency sweep,the simulated G′and G″show a relatively large error,around 25%for G’for example.For this reason,a more robust model,namely the generalized Maxwell model,has been implemented.The calibration procedure is performed in the same fashion as for the Burgers model.Moreover,the tangential micro-contact parameters are scaled w.***.t.the normal ones.This scaling parameter,calledα,is calibrated by minimizing the root mean square error between simulation and experimental data,giving errors below 10%in both G′and G″for a large dataset.Additionally,a full ring plate-plate rheometer setup is simulated,and the simulation is compared with the given experimental dataset,again finding a good agreement.

关键词： DEM Rheology Numerical modeling Viscoelasticity

In situ characterization of particle formation in spray flame synthesis using wide-angle light scattering

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第3期86卷 304-312页

作者： Simon Aβmann Franz J.T.Huber stefan Will Lehrstuhl für Technische Thermodynamik(LTT) Friedrich-Alexander-Universitat Erlangen-Nürnberg(FAU)Erlangen91058Germany Erlangen Graduate Schoolin Advanced Optical Technologies(SAOT) Friedrich-Alexander-Universitat Erlangen-Nurnberg(FAU)Erlangen91052Germany Competence Unit Engineering of Advanced Materials(EAM) Friedrich-Alexander-Universitat Erlangen-Nürnberg(FAU)Erlangen91052Germany

Wide-angle light scattering(WALS)was used for in situ measurements of droplet and nanoparticle size distributions during the synthesis of titania and iron oxide particles from liquid precursor solutions in the standardized SpraySyn burner for spray flame synthesis.Titania was synthesized from titanium tetraisopropoxide(TTIP)and iron oxide from iron(II)nitrate nonahydrate(INN)using ethanol(EtOH)as solvent.Scattering images were taken at heights up to 120 mm above the burner surface and classified into droplet and particle scattering.Droplet size distributions were derived from a sequential analysis of scattering data containing the oscillating Mie pattern,the lognormal size distribution parameters for spherical and fractal particle fractions from a multivariate approach on averaged particle scattering data.The results show that the precursor addition leads to altered evaporation behavior and even droplet disruption probably induced by puffing or micro-explosions compared to pure EtOH.In the case of TTIP(a hygroscopic alkoxide),the synthesis of a large fraction of spheres was observed,while the nitrate INN leads to the formation of mostly fractal aggregates.

关键词： Spray flame synthesis Metal oxide particles Elastic light scattering Droplet size distribution Nanoparticle morphology Particle size distribution

Quality assessment of surgery for colorectal cancer:Where do we stand?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Surgery 2024年第4期16卷 982-987页

作者： stefan Morarasu Cristian Livadaru Gabriel-Mihail Dimofte The Second Department of Surgical Oncology Regional Institute of OncologyIasi 707483Romania

Quality assurance in surgery has been one of the most important topics of debate among colorectal surgeons in the past decade.It has produced new surgical standards that led in part to the impressive oncological outcomes we see in many units today.Total mesorectal excision,complete mesocolic excision(CME),and the Japanese D3 lymphadenectomy are now benchmark techniques embraced by many surgeons and widely recommended by surgical societies.However,there are still ongoing discrepancies in outcomes largely based on surgeon performance.This is one of the main reasons why many countries have shifted colorectal cancer surgery only to high volume centers.Defining markers of surgical quality is thus a perquisite to ensure that standards and oncological outcomes are met at an institutional level.With the evolution of CME surgery,various quality markers have been described,mostly based on measurements on the surgical specimen and lymph node yield,while others have proposed radiological markers(i.***.arterial stumps)measured on postoperative scans as part of the routine cancer follow-up.There is no ideal marker;however,taken together and assembled into a new score or set of criteria may become a future point of reference for reporting outcomes of colorectal cancer surgery in research studies and defining subspecialization requirements both at an individual and hospital level.

关键词： Colorectal cancer Colon surgery Arterial stump Complete mesocolic excision Surgical quality

Mechanically Joined Extrusion Profiles for Battery Trays

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Automotive Innovation 2024年第1期7卷 182-193页

作者： Florian Kneuper stefan Neumann AndréSchulze Mortaza Otroshi A.Erman Tekkaya Gerson Meschut Institute of Forming Technology and Lightweight Components(IUL) TU Dortmund University44227 DortmundGermany Laboratory for Material and Joining Technology(LWF) Paderborn UniversityPaderbornGermany

In the context of electromobility,ensuring the leak tightness of assemblies is of paramount importance,particularly in bat-tery housings.Current battery housings,often featuring base assemblies crafted from extruded aluminum profiles,address the challenge of leak tightness at joints through methods like friction stir welding,a process known for its time and cost intensiveness.The aim of this study is to develop and implement a new type of extruded profile concept to produce tight base assemblies for battery housings by a longitudinal mechanical single stroke joining process.The geometry,the process and the properties of the aluminum profiles are investigated to get a joint that meets the tightness requirements and achieve high load-bearing capacities in agreement with the high homologation requirements set to vehicles with high-voltage systems.The joint is formed by means of a single stage press stroke,which eliminates the need for complex tool designs that are neces-sary for continuous joining(roll joining).Flat steel contact surfaces are used as joining tools.To evaluate the joint quality,force curves from the joining process are analyzed and the resulting joint geometries are assessed using micrographs.The resulting leak tightness of the linear joints is measured by a helium sniffer leak detector and the load-bearing capacities are investigated by shear lap and bending tests and fatigue strength test.The study also explores whether a difference in strength between the two joining partners has a positive effect on the joint properties.

关键词： Joining by plastic deformation Aluminum Leak Tightness

Getting the Most Out of Every Training Day: The Influence of Instructors on Self-Regulated Learning During Firefighter Leadership Courses

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Disaster Risk Science 2024年第3期15卷 332-345页

作者： stefan R?seler Micha Hilbert Guido Hertel Meinald T.Thielsch Department of Psychology University of Münster

Leadership courses in the fire services are highly challenging, and they can seriously exhaust trainees and hamper their selfregulated learning efforts(for example, setting goals, focusing attention, seeking feedback). We theorize that experiences of failure or overload can curtail trainees' available energy resources on subsequent training days, which, in turn, should affect trainees' learning efforts. Given instructors' central role in leadership courses, we hypothesize that supportive and humble instructor behaviors decrease experiences of failure and overload and, thus, increase self-regulated learning. Moreover, we argue that supportive instructor behavior may amplify the positive effects of high energy resources, while humble behavior may alleviate the negative impact of low resource levels. We tested preregistered hypotheses with 118 firefighters participating in two-week leadership courses at a German fire academy. The participants completed short web-based questionnaires before and after classes each day. Multilevel analyses confirmed that perceived daily supportive and humble instructor behavior predicted trainees' reports of daily self-regulated learning activity. Notably, this effect was independent from positive effects of trainees' reported energy resources in the morning. Supportive and humble behavior did not moderate the eff ect of energy resources. Our findings suggest that instructors play a crucial role in facilitating effective learning under challenging training conditions. Furthermore, we offer implications for leaders in fire services, who often conduct trainings with their subordinates.

关键词： Diary study Fire services Instructor behavior Leadership training Resource investment

Septic shock due to Capnocytophaga canimorsus treated with IgM-enriched immunoglobulin as adjuvant therapy in an immunocompetent woman

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Intensive Medicine 2024年第2期4卷 265-268页

作者： Josephine Braunsteiner Stephanie Siedler Dominik Jarczak stefan Kluge Axel Nierhaus Department of Intensive Care Medicine University Medical Centre Hamburg-EppendorfHamburgGermany

Background Capnocytophaga canimorsus(C.canimorsus)belongs to the family Flavobacteriaceae.It is a facultative anaerobic Gram-negative bacillus and belongs to the normal oral microbiota of some mammals,such as cats and dogs.Transmission to humans can occur through the skin after skin abrasion caused by a scratch or a bite.[1]Based on polymerase chain reaction(PCR)analysis,C.canimorsus is present in saliva in 70%-74%of dogs and 55%-57%of cats.

关键词： belongs enriched scratch