1,720,956 research outputs found
IMPROVEMENT OF WEAR AND CORROSION RESISTANCE OF THE H13 TOOL STEEL BY USING THERMAL SURFACE TREATMENT
No full textBoriding, Scanning Electron Microscope (SEM), Energy Dispersive X-ray analysis (EDX), Transmission Electron Microscopy (TEM), American Iron and Steel Institute (AISI), Severe Plastic Deformation (SPD), Surface Treatment of Metals (STM), Wear resistance, Stress Corrosion Cracking (SCC),Surface Engineering (SE), Coefficient Of Friction (COF), Mechanical Properties, Surface Mechanical Attrition Treatment (SMAT), Charge Coupled Device (CCD), Corrosion resistance, XRD analysis, surface quality, Composition Structure, Erosion, Corrosion behaviour, Metal matrix composite, Mechanical surface treatments, Tribology properties, Thermal surface treatments, High temperature corrosion, Wear rate, Sliding wear, Tool steel, Micro hardness, Wear behaviour, Corrosion rate. Surface damage, Microstructure, Surface treatments, Toughness, Wear mechanisms, Structural steel
Plastic Deformation, Mechanical and Adhesive Properties of Bio-Plastic Material
No full textGiven the added need for eco-friendly material, environmental scientists are constantly on the look-out for new solutions. In this respect, biodegradable polymer proved to be a promising one. The Selfix material, being a bioplastic, is biodegradable and, unlike other plastic products, can be considered feasible for the industry as a smart material capable of biodegrading at the end of its life cycle. Using Selfix, waste paper can be re-used, thus eliminating the need for recycling and helping to reduce the CO2 emissions. The present paper develops 3D models with Selfix material to offer benefits such as easy-cutting and sticking properties in a way that can be educational for children. We examine the mechanical properties of this material using tensile testing, laser-cutting, CNC milling, surface roughness and also scanning electron microscope or SEM
INVESTIGATION OF MECHANICAL PROPERTIES AND ADHESION BEHAVIOUR OF BIO-PLASTIC SHEET MATERIAL
Get PDFهدف علماء البيئة هو إيجاد حل لمشكلة البيئة ويبدو أن البوليمر القابل للتحلل هو أحد هذه الحلول. البلاستيك الحيوي قابل للتحلل. يختلف عن غيره من البلاستيك غير القابل للتحلل. يوفر حلًا للصناعة كمواد ذكية وقدرة على التحلل البيولوجي في نهاية دورة حياة المنتج وباستخدام مادة البلاستيك الحيوي يمكن إعادة استخدام ورق النفايات وهذا سيساعد على التخلص من الحاجة إلى إعادة التدوير وتقليل انبعاث الغاز .()
أشارت مراجعة الأدبيات إلى أن مادة البلاستيك الحيوي عبارة عن بوليمر، منتج بلاستيكي حيوي من خليط من المكونات (بوليمرات قابلة للتحلل) ويتم إنتاج هذه المادة بتقنية القولبة بالحقن ، ويتم استخدام القولبة بالحقن في إنتاج قطع من المواد المرنة مثل البلاستيك وهي طريقة سريعة لإنتاج أنواع مختلفة من المواد البلاستيكية بجودة عالية وبصورة دقيقة. ومن الممكن خلال هذا البحث تطوير نماذج ثلاثية الأبعاد باستخدام مادة البلاستيك الحيوي التي توفر آلية تتضمن سهولة القطع والالتصاق حتى يستفيد ويتعلم الأطفال من هذه المادة ، والبلاستيك الحيوي مثل أي مادة أخرى له مزايا وعيوب.
يبحث هذا البحث في الخواص الميكانيكية لمادة البلاستيك الحيوي عن طريق اختبار الشد في المختبر واستخدام القطع بالليزر ، وقياس خشونة السطح ، وقدم البحث توصيات لتطبيق مادة البلاستيك الحيوي.Abstract
The aim of environmental scientists is to find solution of environment problem and is appears that biodegradable polymer is one of these solutions. Bio-Plastic is biodegradable; it differs from other plastic which are non-degradable. It provide solution for industry as a smart material and ability to biodegrade in the end of life cycle for product and by use Bio-Plastic material can reuse waste paper and this will help to eliminate need for recycling and reduction of the emission of gas.
Literature review has indicated that Bio-Plastic material is a smart polymer, Bio-Plastic produce from a mixture of components (Biodegradable polymers) and this material is generated by injection molding technique, and injection molding is used in the production of pieces of elastic material such as plastic and it is rapid way of producing varieties of plastic materials in a high quality precision manner. It has been possible during this research to develop 3D models using Bio-Plastic material which offers automata including easy cutting and sticking so children learning will benefit from this material, Bio-Plastic like any other material has its advantages and disadvantages.
The research has looked into mechanical properties of Bio-Plastic material via tensile testing in the lab and using laser cutting, and Measurement of Surface Roughness. The research has made recommendation for application of Bio-Plastic material.
Investigation of wear behavior of boronized H13 steel under environment of nano-silver-added lubricants coated with different ligands
No full textH13 hot work tool steels are subject to high wear and surface deformation. For this reason, it is important to coat H13 steels and to protect the surface forms with lubricants that can be used in the working environment. This study aimed to increase the wear resistance of H13 hot work tool steel by boronizing and to use nano-silver-doped lubricants under working conditions. The boronizing process was carried out at 700, 800, and 900 degrees C for 2, 4, and 8 h in a nano-boron powder atmosphere. Wear tests were conducted under dry conditions and with nano-silver-doped colloidal suspension prepared with three different ligands. Analyses of the experimental results examined the parameters of friction coefficient, weight loss, microhardness and surface roughness. Ultra-violet (UV), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive x-ray (EDX) spectroscopy, x-ray diffraction (XRD) and 3D topography methods were used for visual and elemental analysis of the surfaces. According to the experimental results, an average coating thickness of 26.5 mu m and hardness value of 2001 HV were obtained under conditions of 900 degrees C for 4 h. The nano-silver-doped colloidal suspension prepared with gelatin yielded 52% better friction coefficient, 88% better weight loss and 51.42% better surface roughness results than the dry wear conditions. It was determined that nano-silver-doped colloidal suspensions prepared with different ligands exhibited different characteristics in the wear environment
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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