New Approach for Versatile Self Piercing Riveting: Joining System and Auxiliary Part

2021 ◽  
Vol 883 ◽  
pp. 3-10
Author(s):  
Fabian Kappe ◽  
Mathias Bobbert ◽  
Gerson Meschut
Keyword(s):  
Boundary Conditions ◽  
Research Work ◽  
High Load ◽  
Continuous Increase ◽  
New Approach ◽  
Load Bearing ◽  
Mechanical Joining ◽  
Wide Range ◽  
Riveting Process

The increasing use of multi-material constructions lead to a continuous increase in the use of mechanical joining techniques due to the wide range of joining possibilities as well as the high load-bearing capacities of the joints. Nevertheless, the currently rigid tool systems are not able to react to changing boundary conditions, like changing the material-geometry-combination. Therefore research work is crucial with regard to versatile joining systems. In this paper, a new approach for a versatile self-piercing riveting process considering the joining system as well as the auxiliary joining part is presented.

scholarly journals Influence of rivet length on joint formation on self-piercing riveting process considering further process parameters

2021 ◽  
Author(s):  
Fabian Kappe ◽  
Christian Roman Bielak ◽  
Vadim Sartisson ◽  
Mathias Bobbert ◽  
Gerson Meschut
Keyword(s):  
Process Parameters ◽  
Automotive Industry ◽  
Raw Materials ◽  
Numerical Study ◽  
Research Work ◽  
High Load ◽  
Continuous Increase ◽  
Wide Range ◽  
Riveting Process ◽  
The Individual

Driven by the CO2-emission law by the European government and the increasing costs for raw materials as well as energy, the automotive industry is increasingly using multi-material constructions. This leads to a continuous increase in the use of mechanical joining techniques and especially the self-piercing riveting is of particular importance. The reason for this is the wide range of joining possibilities as well as the high load-bearing capacities of the joints. To be able to react to changing boundary conditions, like material thickness or strength variation of the sheets, research work is crucial with regard to the increase of versatility. In this paper, a numerical study of the influences on the selfpiercing riveting process is presented. For this purpose, the influence of different process parameters such as rivet length and die depth on various quality-relevant characteristics were investigated. With the help of the design of experiment, significant influences were determined and interactions between the individual parameters are shown.

scholarly journals Constructing a biomimetic robust bi-layered hydrophilic lubrication coating on surface of silicone elastomer

Friction ◽  
2021 ◽  
Author(s):  
Luyao Gao ◽  
Xiaoduo Zhao ◽  
Shuanhong Ma ◽  
Zhengfeng Ma ◽  
Meirong Cai ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Composite Layer ◽  
High Load ◽  
Silicone Elastomer ◽  
Aqueous Lubrication ◽  
Low Friction ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Lubrication Performance ◽  
Wide Range

AbstractSilicone elastomers-based materials have been extensively involved in the field of biomedical devices, while their use is extremely restricted due to the poor surface lubricity and inherent hydrophobicity. This paper describes a novel strategy for generating a robust layered soft matter lubrication coating on the surface of the polydimethylsiloxane (PDMS) silicone elastomer, by entangling thick polyzwitterionic polyelectrolyte brush of poly (sulfobetaine methacrylate) (PSBMA) into the sub-surface of the initiator-embedded stiff hydrogel coating layer of P(AAm-co-AA-co-HEMA-Br)/Fe, to achieve a unified low friction and high load-bearing properties. Meanwhile, the stiff hydrogel layer with controllable thickness is covalently anchored on the surface of PDMS by adding iron powder to provide catalytic sites through surface catalytically initiated radical polymerization (SCIRP) method and provides high load-bearing capacity, while the topmost brush/hydrogel composite layer is highly effective for aqueous lubrication. Their synergy effects are capable of attaining low friction coefficient (COFs) under wide range of loaded condition in water environment with steel ball as sliding pair. Furthermore, the influence of mechanical modulus of the stiff hydrogel layer on the lubrication performance of layered coating is investigated, for which the COF is the lowest only when the modulus of the stiff hydrogel layer well matches the PDMS substrate. Surprisingly, the COF of the modified PDMS could remain low friction (COF < 0.05) stably after encountering 50,000 sliding cycles under 10 N load. Finally, the surface wear characterizations prove the robustness of the layered lubricating coating. This work provides a new route for engineering lubricious silicon elastomer with low friction, high load-bearing capacity, and considerable durability.

scholarly journals A contribution on versatile process chains: joining with adaptive joining elements, formed by friction spinning

2021 ◽  
Author(s):  
Christian Wischer ◽  
Werner Homberg
Keyword(s):  
Current Knowledge ◽  
Research Work ◽  
Sheet Thickness ◽  
Experimental Investigations ◽  
Initial Material ◽  
Ongoing Research ◽  
Mechanical Joining ◽  
Process Chains ◽  
Wide Range ◽  
Joining Process

AbstractNowadays, manufacturing of multi-material structures requires a variety of mechanical joining techniques. Mechanical joining processes and joining elements are used to meet a wide range of requirements, especially on versatile process chains. Most of these are explicitly adapted to only one, specific application. This leads to a less flexibility process chain due to many different variants and high costs. Changes in the boundary conditions like sheet thickness, or layers, lead to a need of re-design over the process and thus to a loss of time. To overcome this drawback, an innovative approach can be the use of individually manufactured and application-adapted joining elements (JE), the so-called Friction Spun Joint Connectors (FSJC). This new approach is based on defined, friction-induced heat input during the manufacturing and joining of the FSJC. This effect increases the formability of the initial material locally and permits them to be explicitly adapted to its application area. To gain a more detailed insight into the new process design, this paper presents a detailed characterization of the new joining technique with adaptive joining elements. The effects and interactions of relevant process variables onto the course and joining result is presented and described. The joining process comprises two stages: the manufacturing of FSJC from uniform initial material and the adaptive joining process itself. The following contribution presents the results of ongoing research work and includes the process concept, process properties and the results of experimental investigations. New promising concepts are presented and further specified. These approaches utilize the current knowledge and expand it systematically to open new fields of application.

Robust genetically optimized skew laminates

2018 ◽  
Vol 233 (1) ◽  
pp. 146-159 ◽  
Author(s):  
Kanak Kalita ◽  
Partha Dey ◽  
Salil Haldar
Keyword(s):  
Genetic Algorithm ◽  
Boundary Conditions ◽  
Optimization Algorithm ◽  
Research Work ◽  
Extensive Study ◽  
Stacking Sequence ◽  
Different Boundary Conditions ◽  
Fundamental Frequencies ◽  
Wide Range ◽  
Safe Limit

The present research work explores genetically optimized skew laminates, whose stacking sequence has been varied to maximize their fundamental frequencies with the help of an efficient optimization algorithm. Genetic algorithm, rather than being applied blindly with empirical parameters, is tuned with respect to the problem at hand. Following an extensive study, genetic algorithm parameters are selected carefully so as to ensure a robust optimized stacking sequence. The sensitivity of ply angles is also investigated so as to warrant against marginal manufacturing perturbations. The safe limit for variation of ply angles without much hampering the frequency is also recommended. Validation with existing solutions illustrates the efficiency of the procedure. A wide range of results with rectangular/ skew plates of different layers having symmetric/ antisymmetric ply-orientations, subject to different boundary conditions are solved, which demonstrate the efficacy of the approach.

Justification of the need to improve the legal, regulatory and methodological framework for the spread of parasitic infections in the provision of medical care

2020 ◽  
Vol 99 (5) ◽  
pp. 493-497
Author(s):  
M. M. Aslanova ◽  
T. V. Gololobova ◽  
K. Yu. Kuznetsova ◽  
Tamari R. Maniya ◽  
D. V. Rakitina ◽  
...  
Keyword(s):  
Medical Care ◽  
Research Work ◽  
Hospital Environment ◽  
Parasitic Infections ◽  
Infusion Therapy ◽  
Methodological Framework ◽  
Production Environment ◽  
Medical Institutions ◽  
Medical Network ◽  
Wide Range

Introduction. The purpose of our work was to justify the need to improve the legislative, regulatory and methodological framework and preventative measures in relation to the spread of parasitic infections in the provision of medical care. There is a wide range of pathogens of parasitic infestations that are transmitted to humans through various medical manipulations and interventions carried out in various medical institutions. Contaminated care items and furnishings, medical instruments and equipment, solutions for infusion therapy, medical personnel’s clothing and hands, reusable medical products, drinking water, bedding, suture and dressing materials can serve as a major factor in the spread of parasitic infections in the provision of medical care. Purpose of research is the study of the structure and SMP of parasitic origin, circulating on the objects of the production environment in multi-profile medical and preventive institutions of stationary type in order to prevent the occurrence of their spread within medical institutions. Material and methods. The material for the study was flushes taken from the production environment in 3 multi-profile treatment and prevention institutions of inpatient type: a multi-specialty hospital, a maternity hospital and a hospital specializing in the treatment of patients with intestinal diseases for the eggs of worms and cysts of pathogenic protozoa. Results. During the 2-year monitoring of medical preventive institutions, a landscape of parasitic contamination was found to be obtained from the flushes taken from the production environment objects in the premises surveyed as part of the research work. Discussions. In the course of research, the risk of developing ISMP of parasitic origin was found to be determined by the degree of epidemiological safety of the hospital environment, the number and invasiveness of treatment and diagnostic manipulations and various medical technologies. Conclusion. It is necessary to conduct an expert assessment of regulatory and methodological documents in the field of epidemiological surveillance and sanitary and hygienic measures for the prevention of medical aid related infections of parasitic origin, to optimize the regulatory and methodological base, to develop a number of preventive measures aimed at stopping the spread of parasitic infections in the medical network.

Factors Affecting Molecular Self-Assembly and Its Mechanism

2012 ◽  
Vol 9 (1) ◽  
pp. 43 ◽  
Author(s):  
Hueyling Tan
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
Molecular Engineering ◽  
Molecular Structures ◽  
Polymer Science ◽  
New Approach ◽  
Factors Affecting ◽  
Dna Structures ◽  
Self Assembling ◽  
Wide Range

Molecular self-assembly is ubiquitous in nature and has emerged as a new approach to produce new materials in chemistry, engineering, nanotechnology, polymer science and materials. Molecular self-assembly has been attracting increasing interest from the scientific community in recent years due to its importance in understanding biology and a variety of diseases at the molecular level. In the last few years, considerable advances have been made in the use ofpeptides as building blocks to produce biological materials for wide range of applications, including fabricating novel supra-molecular structures and scaffolding for tissue repair. The study ofbiological self-assembly systems represents a significant advancement in molecular engineering and is a rapidly growing scientific and engineering field that crosses the boundaries ofexisting disciplines. Many self-assembling systems are rangefrom bi- andtri-block copolymers to DNA structures as well as simple and complex proteins andpeptides. The ultimate goal is to harness molecular self-assembly such that design andcontrol ofbottom-up processes is achieved thereby enabling exploitation of structures developed at the meso- and macro-scopic scale for the purposes oflife and non-life science applications. Such aspirations can be achievedthrough understanding thefundamental principles behind the selforganisation and self-synthesis processes exhibited by biological systems.

Extraction of DNA from a Wide Range of Objects by Treatment with Ammonium Salts

2020 ◽  
Vol 36 (6) ◽  
pp. 98-106
Author(s):  
E.I. Levitin ◽  
B.V. Sviridov ◽  
O.V. Piksasova ◽  
T.E. Shustikova
Keyword(s):  
Dna Extraction ◽  
Dna Isolation ◽  
Tissue Samples ◽  
New Approach ◽  
Cell Wall Disruption ◽  
Wide Range ◽  
Low Salt ◽  
Mammalian Blood ◽  
Plasmid Extraction ◽  
Two Hybrid

Currently, simple, rapid, and efficient techniques for DNA isolation from a wide range of organisms are in demand in biotechnology and bioinformatics. A key (and often limiting) step is the cell wall disruption and subsequent DNA extraction from the disintegrated cells. We have developed a new approach to DNA isolation from organisms with robust cell walls. The protocol includes the following steps: treatment of cells or tissue samples with ammonium acetate followed by cell lysis in low-salt buffer with the addition of SDS. Further DNA extraction is carried out according to standard methods. This approach is efficient for high-molecular native DNA isolation from bacteria, ascomycetes, yeast, and mammalian blood; it is also useful for express analysis of environmental microbial isolates and for plasmid extraction for two-hybrid library screening. express method for DNA isolation; ammonium salt treatment (в русских ключевых такой порядок), osmotic breakage of cells This study was financially supported by the NRC "Kurchatov Institute"-GOSNIIGENETIKA Kurchatov Genomic Center.

Development and Evaluation of Sustained Release Lipid Nanocarriers for Curcumin

2020 ◽  
Vol 5 (3) ◽  
pp. 224-235
Author(s):  
Harshal A. Pawar ◽  
Bhagyashree D. Bhangale
Keyword(s):  
Drug Delivery ◽  
Sustained Release ◽  
Drug Delivery Systems ◽  
Biological Activities ◽  
Curcuma Longa ◽  
Research Work ◽  
Elimination Rate ◽  
Delivery Systems ◽  
Physicochemical Stability ◽  
Wide Range

Background: Lipid based excipients have increased acceptance nowadays in the development of novel drug delivery systems in order to improve their pharmacokinetic profiles. Drugs encapsulated in lipids have enhanced stability due to the protection they experience in the lipid core of these nano-formulations. Phytosomes are newly discovered drug delivery systems and novel botanical formulation to produce lipophilic molecular complex which imparts stability, increases absorption and bioavailability of phytoconstituent. Curcumin, obtained from turmeric (Curcuma longa), has a wide range of biological activities. The poor solubility and wettability of curcumin are responsible for poor dissolution and this, in turn, results in poor bioavailability. To overcome these limitations, the curcumin-loaded nano phytosomes were developed to improve its physicochemical stability and bioavailability. Objective: The objective of the present research work was to develop nano-phytosomes of curcumin to improve its physicochemical stability and bioavailability. Methods: Curcumin-loaded nano phytosomes were prepared by using phospholipid Phospholipon 90 H using a modified solvent evaporation method. The developed curcumin nano phytosomes were evaluated by particle size analyzer and differential scanning calorimetry (DSC). Results: Results indicated that phytosomes prepared using curcumin and lipid in the ratio of 1:2 show good entrapment efficiency. The obtained curcumin phytosomes were spherical in shape with a size less than 100 nm. The prepared nano phytosomal formulation of curcumin showed promising potential as an antioxidant. Conclusion: The phytosomal complex showed sustained release of curcumin from vesicles. The sustained release of curcumin from phytosome may improve its absorption and lowers the elimination rate with an increase in bioavailability.

ESRC Review

2020 ◽  
pp. 657-698
Author(s):  
Simeon J. Yates ◽  
Jordana Blejmar
Keyword(s):  
Social Research ◽  
Social Science Research ◽  
Research Work ◽  
Science Research ◽  
Wide Range ◽  
The Us ◽  
Levels Of Automation ◽  
The Uk ◽  
Technological World ◽  
Ways Of Being

Two workshops were part of the final steps in the Economic and Social Research Council (ESRC) commissioned Ways of Being in a Digital Age project that is the basis for this Handbook. The ESRC project team coordinated one with the UK Defence Science and Technology Laboratory (ESRC-DSTL) Workshop, “The automation of future roles”; and one with the US National Science Foundation (ESRC-NSF) Workshop, “Changing work, changing lives in the new technological world.” Both workshops sought to explore the key future social science research questions arising for ever greater levels of automation, use of artificial intelligence, and the augmentation of human activity. Participants represented a wide range of disciplinary, professional, government, and nonprofit expertise. This chapter summarizes the separate and then integrated results. First, it summarizes the central social and economic context, the method and project context, and some basic definitional issues. It then identifies 11 priority areas needing further research work that emerged from the intense interactions, discussions, debates, clustering analyses, and integration activities during and after the two workshops. Throughout, it summarizes how subcategories of issues within each cluster relate to central issues (e.g., from users to global to methods) and levels of impacts (from wider social to community and organizational to individual experiences and understandings). Subsections briefly describe each of these 11 areas and their cross-cutting issues and levels. Finally, it provides a detailed Appendix of all the areas, subareas, and their specific questions.

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