The Masteralloy Concept for Sintered Steels - New Impetus for a Classical Approach

2021 ◽  
Vol 42 ◽  
pp. 9-16
Author(s):  
Herbert Danninger ◽  
Raquel de Oro Calderon ◽  
Stefan Geroldinger ◽  
Christian Gierl-Mayer ◽  
John J. Dunkley
Keyword(s):  
Large Scale ◽  
Oxygen Affinity ◽  
Cost Effective ◽  
The Other ◽  
Water Atomization ◽  
The Matrix ◽  
Recent Developments ◽  
Long Time ◽  
Pressure Water ◽  
High Oxygen Affinity

Among the various alloying techniques used in powder metallurgy, the masteralloy concept has been known for a long time. However, its use for production of ferrous precision parts has been hampered by several obstacles such as poor output of the useful fine fractions, high tool wear and slow homogenization kinetics of the alloy elements in the matrix. On the other hand, the masteralloy concept is particularly interesting for introducing cost-effective alloy elements such as Cr, Mn and Si since the masteralloy approach at least alleviates the problems caused by the high oxygen affinity of these elements. In the present study it is shown that recent developments have given a boost to this classical concept, one of these developments being powder manufacturing by high pressure water atomization which dramatically increases the yield of fine masteralloy fractions. The other progress is availability of thermodynamic software that enables defining masteralloy compositions with low melting range and thus fast homogenization also at moderate sintering temperatures. Combined, these new developments open the door for implementation of the masteralloy route in large scale PM parts production.

Microwave Assisted Synthesis of Ru3Pd6Pt Cathode Catalyst in a PEM Fuel Cell

2013 ◽  
Vol 16 (3) ◽  
pp. 147-150 ◽  
Author(s):  
F. Leyva-Noyola ◽  
O. Solorza-Feria
Keyword(s):  
Fuel Cell ◽  
Large Scale ◽  
High Pressures ◽  
Cost Effective ◽  
Pem Fuel Cell ◽  
Reduction Reaction ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Long Time ◽  
Set Up

Nanoparticles of Ru3Pd6Pt have been previously produced by different synthesis routes that involve high temperatures and relative high pressures and long time. The usage of a conventional microwave assisted synthesis reduces environmental risk impact as well as the cost effective production in large scale with minimum set up modifications. These features are the motivations for the use of microwaves in the synthesis of the Ru3Pd6Pt catalyst for PEM fuel cell applications to reduce the Pt loading. In this communication a tri-metallic electrocatalyst was produced by the reduction of the corresponding metallic salts, RuCl3, PdCl2, and H2PtCl6 in ethylene glycol using a modified conventional microwave device. Oxygen reduction reaction kinetic analysis results conducted to a Tafel slope, (-b = 41.2 ± 1.7 mV dec-1) at low overpotential, and exchange current density (i0 = 3.01 ± 0.39 × 10-5 mA cm-2) in 0.5M H2SO4. This electrocatalyst exhibited good performance and stability in a single H2/O2PEM fuel cell.

scholarly journals Electrochemical Biosensors in Food Safety: Challenges and Perspectives

2021 ◽  
Author(s):  
Antonella Curulli
Keyword(s):  
Food Chain ◽  
Electrochemical Sensors ◽  
Cost Effective ◽  
Electrochemical Biosensors ◽  
Sensing Systems ◽  
Highly Sensitive ◽  
Skilled Personnel ◽  
Recent Developments ◽  
Long Time ◽  
Key Issues

Safety and quality are key issues for the food industry. Consequently, there is a growing demand to preserve the food chain and products against substances toxic, harmful to human health such as contaminants, allergens, toxins, or pathogens. For this reason, it is mandatory to develop highly sensitive, reliable, rapid, and cost-effective sensing systems/devices such as electrochemical sensors/biosensors. Generally, conventional techniques are limited by long time of analyses, expensive and complex procedures, and they require skilled personnel. Therefore, the development of performant electrochemical biosensors can significantly support the screening of food chain and products. Here, we report some of the recent developments in this area and analyze the contributions produced by electrochemical biosensors in the food screening and the challenges to address.

Recent developments in heterogeneous photocatalysts for solar-driven overall water splitting

2019 ◽  
Vol 48 (7) ◽  
pp. 2109-2125 ◽  
Author(s):  
Zheng Wang ◽  
Can Li ◽  
Kazunari Domen
Keyword(s):  
Solar Energy ◽  
Water Splitting ◽  
Large Scale ◽  
Cost Effective ◽  
Hydrogen Energy ◽  
Overall Water Splitting ◽  
Effective Technology ◽  
Recent Developments ◽  
Renewable Hydrogen

Overall water splitting based on particulate photocatalysts is an easily constructed and cost-effective technology for the conversion of abundant solar energy into clean and renewable hydrogen energy on a large scale.

Mechanics and Physics of Brittle to Ductile Transitions in Fracture1

2000 ◽  
Vol 123 (1) ◽  
pp. 1-11 ◽  
Author(s):  
A. S. Argon
Keyword(s):  
World War Ii ◽  
Large Scale ◽  
Atomic Level ◽  
World War ◽  
Alloy Development ◽  
Brittle To Ductile Transition ◽  
Recent Developments ◽  
Macroscopic Fracture ◽  
Long Time ◽  
Bifurcation Behavior

The mechanisms of brittle-to-ductile transition of fracture in intrinsically brittle crystalline solids such as structural steel have been of great technological interest for a long time. While much useful phenomenology on this important bifurcation behavior has evolved through material testing and alloy development throughout the period following the large scale fractures in Liberty ships during and after World War II, fundamental mechanistic understanding has been lacking until recent times. Over the past decade or so, a renewed level of interest has resulted in a number of fundamental studies of both experimental nature and modeling of crack-tip response which demonstrated a remarkable connection of atomic level processes at tips of cleavage cracks and the macroscopic fracture transitions. These mechanistic connections have not only gone a long way in providing basic rationale for some of the successful empirical practices in alloy design and microstructure control, but clear the way for further advances based on basic atomic level processes governing crystal plasticity. Here we give an overview of some recent developments in this area emanating from our own researches.

scholarly journals Composting: A Sustainable Route for Processing of Biodegradable Waste in India

2020 ◽  
pp. 39-60
Author(s):  
Ashootosh Mandpe ◽  
Sweta Kumari ◽  
Sunil Kumar
Keyword(s):  
Large Scale ◽  
Cost Effective ◽  
Well Being ◽  
Small Scale ◽  
Cost Ratio ◽  
Biodegradable Waste ◽  
Benefit Cost Ratio ◽  
Recent Developments ◽  
The Government ◽  
Increasing Demand

AbstractSurging populations, coupled with the ever-increasing demand for sustenance, have led to the generation of behemoth proportions of wastes throughout the globe. The processing of such a considerable amount of waste has raised concerns for environmental planners, policymakers, and researchers in regard to maintaining sustainability. Biodegradable waste is a part of the total waste stream. Consideration should be given to the importance of making better use of biodegradable waste. The technology that is adopted for the management of biodegradable waste should be ecologically sustainable and cost-effective, as well as beneficial to social well-being. The most efficient way of managing biodegradable waste must include different methods for the optimal utilisation of such waste, ranging from the small scale (single household) to the very large scale (entire city). Amid all the other waste processing technologies, composting stands out as a most potent option because of its ability to maintain and restore soil fertility, along with the transformation of waste into a resource. Composting is one of the few technologies which has a benefit–cost ratio higher than 1 at all scales of operation. This chapter analyses the most significant aspects of the composting process, including the recent developments and dynamics involved in it. The chapter discusses various aspects of composting via analysis of the integrated waste management system and composting-related projects implemented at the community level in the Indian context. Finally, the chapter presents policies and the efforts put in place by the Government of India with the aim of encouraging composting practice and related activities.

scholarly journals A Review on Microbial Fuel Cells

2021 ◽  
Vol 39 (1A) ◽  
pp. 1-8
Author(s):  
Baidaa A. Kitafa ◽  
Afaf J. Obaid Al-saned
Keyword(s):  
Organic Matter ◽  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Microbial Fuel Cells ◽  
Large Scale ◽  
Cost Effective ◽  
Electricity Production ◽  
Anaerobic Conditions ◽  
Long Time ◽  
Micro Organisms

The Microbial Fuel Cell (MFC) is a bioreactor with which the chemical energy in chemical bonds of organic compounds are converted to electricity under anaerobic conditions through catalytic reactions of micro-organisms. It has been familiar for a long time that electricity can be generated directly through using bacteria to break organic matter. A microbial fuel cell can also serve in different wastewater treatment to destroy organic matter. The development of MFC technology requires a greater understanding of the microbial processes  for MFCs, and their components, limitations, factors and design this system, to be simpler and large scale system developed; so that it would increase electricity production while being cost-effective. This review discusses, what is the MFCs and the basic principle of how MFC operate, the most essential MFC components and their relevance, multiple MFC designs that have been presented as efficient configurations, Applications of MFCs, and several types of wastewater as substrates in MFC also highlighted.

HIGH-ORDER EXPLICIT TIME-INTEGRATORS FOR DISCONTINUOUS GALERKIN DISCRETIZATIONS OF THE MAXWELL EQUATIONS

2012 ◽  
Vol 04 (01) ◽  
pp. 1250029
Author(s):  
H. FAHS ◽  
M. SAFA
Keyword(s):  
Discontinuous Galerkin ◽  
Large Scale ◽  
Formal Solution ◽  
High Order ◽  
Practical Implementation ◽  
Test Problems ◽  
Time Integrators ◽  
The Matrix ◽  
Long Time ◽  
Exponential Formula

We investigate the practical implementation of a high-order explicit time-stepping method based on polynomial approximations, for possible application to large-scale problems in electromagnetics. After the spatial discretization by a high-order discontinuous Galerkin method, we obtain a linear system of differential equations of the form, [Formula: see text], where [Formula: see text] is a matrix containing the spatial derivatives and t is the time variable. The formal solution can be written in terms of the matrix exponential, [Formula: see text], acting on some vectors. We introduce a general family of time-integrators based on the approximation of [Formula: see text] by Jacobi polynomial expansions. We discuss the efficient implementation of this technique, and based on some test problems, we compare the virtues and shortcomings of the algorithm. We also demonstrate how these schemes provide an efficient alternative to standard explicit integrators for computing solutions over long time intervals.

scholarly journals Future CO2 emissions from shipping: four-scenarios using a multi-level perspective – a proposed methodology

2018 ◽  
Vol 58 ◽  
pp. 01031
Author(s):  
Peter Wells ◽  
Stephen Pettit ◽  
Wessam Abouarghoub ◽  
Jane Haider ◽  
Anthony Beresford
Keyword(s):  
Large Scale ◽  
The Other ◽  
Potential Range ◽  
Shipping Industry ◽  
Limited Impact ◽  
Transitions Theory ◽  
Recent Developments ◽  
Multi Level ◽  
Business As Usual ◽  
Over Time

Previous work by Pettit et al (2017) drew on Socio-technical Transitions Theory (STT) to contextualise recent developments in the technological and operational eco-efficiency of ships which may ameliorate sustainability issues in shipping. Within STT the Multi-Level Perspective (MLP) is a framework used to explain the permeation of innovations into society (Geels, 2014). The framework has three levels: Landscape; Regime and Niche. In order to develop a better understanding of changes that may take place in the future, this paper uses the MLP to assess the broad range of challenges facing the shipping industry with respect to future CO2 emissions at each of the three levels. The framework is applied to four scenarios for global shipping in order to understand the potential range of outcomes for CO2 emissions. The four scenarios are: ‘Business as Usual’; ‘Managed Transition’; ‘Chaotic Transition’; and ‘Managed Degrowth’. It is contended that changes in the shipping industry alone are unlikely to lead to large-scale changes in its CO2 emissions. Under ‘Business as Usual’ conditions, CO2 emissions will continue to rise as the changes required at all three levels, but primarily at the regime level, will have limited impact. Under the other three scenarios, it is suggested that there is room for optimism that CO2 emissions will decline over time.

scholarly journals Kashmiri Crafts - A Fascination for Tourists

2021 ◽  
Vol VI (II) ◽  
pp. 44-48
Author(s):  
Junaid Bashir ◽  
Anas Mahmud Arif ◽  
Owais Khan
Keyword(s):  
Large Scale ◽  
The Other ◽  
European Countries ◽  
Atmospheric Conditions ◽  
Long Time ◽  
The One ◽  
At Home ◽  
Making Art

Kashmir has different brightening prestigious expressions and specialities which have been famous for quite a long time for their fine work and magnificence. To be sure, Kashmiri speciality items are unbelievable. Artwork is the primary wellspring of pay for the Kashmiris. Speciality work or essentially make is a kind of embellished work hand made utilizing just basic apparatuses. Things made by large-scale manufacturing or using machines are not handiwork items. The Kashmiri specialists are consistently alive to the beautiful encompassing. It communicates a reaction to the excellence around the formation of an enormous assortment of pursuing or decorating flower themes interlaced into multifaceted examples. The art items are promoted in Asia as well as in European countries. This article is to portray the significance of Kashmiri craftsmanship and artworks from hundreds of years. It additionally portrays how Kashmiris are imaginatively and customarily associated with their conventional artwork. The center on the traditional heritage is built on neighborhood uniqueness on the one hand and social tourism on the other. Kashmir could be a visitor range and can win significant income from yearly visits, although the majority of tourists head for the greatly attractive coast during the summer and winter. In Kashmir, with its freezing winter when atmospheric conditions are semi-arctic, the artisans use their time at home as inventive knowledge in making art crafts of stunning excellence. Regal support empowered these painstaking works from early occasions till these items, light in weight and wealthy in workmanship, found attraction and magnetism for tourists, locals, and abroad.

2D Color-Intensity Representation of Ultrasonic Thickness Gauge Measurements

2020 ◽  
pp. 1192-1198
Author(s):  
M.S. Mohammad ◽  
Tibebe Tesfaye ◽  
Kim Ki-Seong
Keyword(s):  
Cost Effective ◽  
The Other ◽  
Thickness Gauge ◽  
Color Intensity ◽  
Digital Readout ◽  
Flat Surfaces ◽  
Video Cameras ◽  
Wide Range ◽  
Cost Effective Alternative ◽  
Ultrasonic Thickness

Ultrasonic thickness gauges are easy to operate and reliable, and can be used to measure a wide range of thicknesses and inspect all engineering materials. Supplementing the simple ultrasonic thickness gauges that present results in either a digital readout or as an A-scan with systems that enable correlating the measured values to their positions on the inspected surface to produce a two-dimensional (2D) thickness representation can extend their benefits and provide a cost-effective alternative to expensive advanced C-scan machines. In previous work, the authors introduced a system for the positioning and mapping of the values measured by the ultrasonic thickness gauges and flaw detectors (Tesfaye et al. 2019). The system is an alternative to the systems that use mechanical scanners, encoders, and sophisticated UT machines. It used a camera to record the probe’s movement and a projected laser grid obtained by a laser pattern generator to locate the probe on the inspected surface. In this paper, a novel system is proposed to be applied to flat surfaces, in addition to overcoming the other limitations posed due to the use of the laser projection. The proposed system uses two video cameras, one to monitor the probe’s movement on the inspected surface and the other to capture the corresponding digital readout of the thickness gauge. The acquired images of the probe’s position and thickness gauge readout are processed to plot the measured data in a 2D color-coded map. The system is meant to be simpler and more effective than the previous development.

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