High-energy processing of materials-technologies of the 21st century

2013 ◽  
pp. 179-184
Keyword(s):  
21St Century ◽  
High Energy ◽  
Energy Processing

A Comparative Study between Low and High-Energy Milling Processes for the Production of HD PrFeCoBNb Sintered Magnets

2008 ◽  
Vol 591-593 ◽  
pp. 114-119 ◽  
Author(s):  
E.A. Périgo ◽  
E.P. Soares ◽  
Hidetoshi Takiishi ◽  
C.C. Motta ◽  
Rubens Nunes de Faria Jr.
Keyword(s):  
Ball Milling ◽  
Permanent Magnets ◽  
High Energy ◽  
Maximum Energy ◽  
Maximum Energy Product ◽  
High Energy Milling ◽  
Energy Product ◽  
Energy Processing ◽  
Hydrogen Decrepitation ◽  
High Degree

Roller-ball milling (RBM) or planetary ball milling (PBM) have been used together with the hydrogen decrepitation (HD) process to produce sintered permanent magnets based on a mixture of Pr16Fe76B8 and Pr14.00Fe63.90Co16.00B6.00Nb0.10 magnetic alloys. Five distinct compositions have been studied comparing low- and high-energy milling. Magnets with a particular composition and prepared using these two routes exhibited similar magnetic properties. Modifications have been carried out in the procedure of the HD stage for PBM in order to guarantee a high degree of crystallographic alignment. Pr15.00Fe69.95Co8.00B7.00Nb0.05 magnets showed the best maximum energy product for both processing routes (~ 247 kJm-3). A significant reduction in the milling time (93%) has been achieved with high-energy processing, the greatest advantage over the low-energy route.

Designing Energy-Storage Devices from Textile Materials

2012 ◽  
Vol 441 ◽  
pp. 231-234 ◽  
Author(s):  
Xiang Wu Zhang ◽  
Li Wen Ji ◽  
Zhan Lin ◽  
Ying Li
Keyword(s):  
Energy Storage ◽  
Lithium Ion Batteries ◽  
21St Century ◽  
Lithium Ion ◽  
Electrospun Nanofibers ◽  
High Energy ◽  
Energy Storage Devices ◽  
Textile Materials ◽  
Storage Devices ◽  
Energy Science

Research and development in textiles have gone beyond the conventional applications as clothing and furnishing materials; for example, the convergence of textiles, nanotechnologies, and energy science opens up the opportunity to take on one of the major challenges in the 21st century energy. This presentation addresses the development of high-energy lithium-ion batteries using electrospun nanofibers.

scholarly journals Growth and Maturation: The Connection with Physical Activity to Obese Children

2001 ◽  
Vol 7 (1) ◽  
pp. 42-48
Author(s):  
Patrick LAU
Keyword(s):  
Physical Activity ◽  
21St Century ◽  
Physical Inactivity ◽  
High Energy ◽  
Obesity Management ◽  
Obese Children ◽  
High Energy Intake ◽  
Prevention And Treatment ◽  
Health Related ◽  
Unrealistic Expectations

LANGUAGE NOTE | Document text in English; abstract also in Chinese.Childhood obesity is expected more serious in the 21st century. The etiology of obesity has been investigated for more than decades and nobody will argue that physical inactivity and high-energy intake are the two core factors. For the sake of prevention and treatment, it is imperative to look into the nature and health-related effects of physical activity towards obesity management. The objective of this chapter is to clarify the effects of physical activity participation on adolescents' body changes and avoid unrealistic expectations from it. The content is mainly focus upon the growth and maturation characteristics of adolescents who are regularly active in physical activity and the cardiovascular changes through physical activity.兒童肥胖問題在廿一世紀將會愈趨嚴重，在過去十多年來研究一直探討其成因，基本上運動與營養控制兩者一致被確認為決定性的因素。因此在預防與治療而言，運動對肥胖處理及治療的效果及性質上，深入的研究探討是必要的，本文旨在釐清兒童在成長過程中參與運動對身體變化的影響，以防止肥胖兒童對身體產生不切實際的期望。

Modern technologies of forming

2019 ◽  
Author(s):  
Валерий Лебедев ◽  
Valeriy Lebedev ◽  
Михаил Тамаркин ◽  
Mihail Tamarkin ◽  
Юрий Анкудимов ◽  
...  
Keyword(s):  
Electrical Energy ◽  
High Energy ◽  
Machine Building ◽  
Processing Methods ◽  
Power Sources ◽  
The Third ◽  
Processed Material ◽  
Energy Processing ◽  
Physical And Chemical ◽  
Modern Technologies

The textbook presents modern technologies of forming parts by high-energy processing methods based on the use of physical and chemical effects. High-energy processing methods should be considered as one of the areas of modern electrical engineering, which is based on the use of electrical energy for direct or indirect use in the formation of surfaces. It is shown that depending on the type of impact on the processed material they can be divided into four large groups. The first, the most numerous group, is electrophysical methods using highly concentrated power sources. This group includes EDM, electric, plasma, beam and laser processing. The second group – electrochemical methods based on the simultaneous conversion of the entire surface of the treated electrical energy into chemical energy. It includes numerous types of electrochemical treatment based on anodic dissolution of the material and chemical milling methods based on dissolution of the material by acids and alkalis. The third group – combined processing processes, which combines simultaneously or sequentially the use of several types of processes that effectively complement each other's own energy effects. The fourth group includes methods of pulsed mechanical action on the processed material. It's magnetic pulse, explosive., ultrasonic treatment. Methodically, the textbook is built as follows. The first Chapter presents physical and chemical methods forming parts with the use of the tool. In the second - electrophysical methods of forming parts using highly concentrated energy sources. In the third, integrated technologies of forming parts and scientific approaches to the creation of new high-efficient methods of forming parts. For each method, revealed its essence, technological capabilities, means of technological equipment, as well as the conditions for the rational use and methods of designing in different variants of technological processes of manufacturing products. In conclusion, a set of control questions for students to learn the material set out in the textbook. The proposed manual is prepared in accordance with the educational programs in the direction of 150405 "Design and technological support of machine-building industries" and is intended for masters of the above areas, as well as for specialists involved in technological training of machine-building industries.

scholarly journals Rates of energy processing by blowflies: the uses for a joule vary with food quality and quantity

1990 ◽  
Vol 150 (1) ◽  
pp. 257-268
Author(s):  
F. R. Hainsworth ◽  
G. Fisher ◽  
E. Precup
Keyword(s):  
High Energy ◽  
Meal Size ◽  
Phormia Regina ◽  
Cube Root ◽  
Long Term Storage ◽  
Energy Processing ◽  
High Concentrations ◽  
Process Energy ◽  
Term Storage

Data on the variation of crop volumes with time for blowflies (Phormia regina Meigen) fed various volumes and concentrations of fructose or sucrose (from Gelperin, 1966, and Edgecomb et al. 1987) were used to characterize energy processing rates to test the assumption of food energy addivity of optimal foraging theories. Six regression models (linear, square root, cube root, hyperbolic, inverse cube root and exponential) were compared for data from Edgecomb et al. (1987) with measurements of crop volumes from 10 min to 5 h after blowflies were fed 9.7 or 14.5 microliters of 0.25 moll-1 sucrose. Only the hyperbolic regression could be discriminated as statistically different, and the linear model was selected as most parsimonious for examining rates of energy processing. About the same volume bypassed the crop for flies fed 9.7 or 14.5 microliters. Volume rates of crop emptying (from Gelperin, 1966) did not change at intermediate concentrations but decreased from lowest and to highest concentrations. Energy processing patterns indicate that long-term storage rates increase with meal size and at intermediate concentrations and decrease (3.0 moll-1 fructose) or remain constant (2.0 moll-1 sucrose) at high concentrations, so the uses for a unit of energy are not additive across concentrations and meal sizes. Animals that process energy in this way should attempt to maximize meal size and include high-energy foods in their diet out of proportion to the amount of energy gained for the time spent foraging.

scholarly journals Modification of surface layers by high energy treatment

2019 ◽  
pp. 109-116
Author(s):  
M. N. Vereschagin ◽  
S. N. Tselueva ◽  
M. Yu. Tseluev
Keyword(s):  
Laser Radiation ◽  
Crystallization Process ◽  
High Energy ◽  
Rate Of Change ◽  
Surface Layers ◽  
Surface Areas ◽  
Precision Alloys ◽  
Wide Range ◽  
Energy Processing ◽  
Metal Products

Exposure to laser radiation leads to a change in the temperature field of the substance being treated. The nature of heating, which is determined by the rate of change of temperature, temperature gradients, the time to reach the temperatures of structural and phase transitions, is different depending on the properties of the material being processed and the processing conditions.When modifying the surface layers by high-energy processing by changing the power and time of exposure to laser radiation, you can get a wide range of structural states of the treated surface areas of the material.It is shown that the shape of TVP diagrams and cooling curves of precision alloys on the surface of a two-layer metal system after heating them with laser radiation are determined by the competition of two processes acting in opposite directions: an increase in the driving force of the crystallization process with an increase in supercooling and a decrease in the surface of atoms.The method of surface modification by moving laser radiation allows to obtain amorphous functional layers of precision alloys on the surface of metal products.

scholarly journals A Chance for the Climate. Fuel of the 21st Century – Analysis of the Perspective of Climate Neutrality on the Example of the Polish Hydrogen Strategy

2021 ◽  
Vol 58 (2) ◽  
pp. 120-138
Author(s):  
Krzysztof Cygańczuk ◽  
Paweł Wolny
Keyword(s):  
Renewable Energy ◽  
Natural Gas ◽  
21St Century ◽  
Alternative Fuels ◽  
High Energy ◽  
Green Energy ◽  
Sustainable Growth ◽  
High Energy Density ◽  
Oil Refining ◽  
Gas Emissions

Aim: This article attempts to present the issues related to the search for alternatives to energy resources in all sectors of the economy. The direction of the search is to choose “green energy” (in this case hydrogen), which, due to its potential wide application, is already beginning to be treated as an instrument of carbon neutrality. Most EU countries have agreed that they will be carbon-neutral by 2050, which should result in the reduction of greenhouse gas emissions to the atmosphere by around 95% compared to the beginning of the gas emissions calculation in 1990. However, achieving emission neutrality will require a far-reaching elimination of emissions not only in the power sector, but also in other sectors (including industry, transport and heating). These areas still rely on emission fossil fuels (coal, crude oil and natural gas), which cannot be directly replaced with electricity from RES. Introduction: Hydrogen is not a source of energy, but it is a very effective carrier. Although it is practically not in the free state, it is very often found in the form of chemical compounds such as CH4 (methane) or H2O (water). In order to extract the energy it contains, it must be isolated from the molecules it is composed of. Hydrogen can be transported via gas pipelines (gaseous) or tankers (liquefied). It is currently used in the petrochemical industry, in - cluding for oil refining and chemical industry for the production of fertilizers, ammonia or methanol. Recently, hydrogen has become a topic that is often discussed in the public space in the context of climate protection (and thus decarbonisation of the economy). This fuel is credited with extraordinary potential and applicability in so many areas that it should be widely regarded as oil of the 21st century and a key element of the new energy policy. Moreover, the investment in hydrogen should support sustainable growth and job creation, which will be critical when recovering from the COVID-19 pandemic. Methodology: The article provides an overview of research questions and the most recent results of considerations. It presents a multidimensional and interdisciplinary analysis of the suitability of alternative fuels and the implementation of the related projects. The analysis of the topic was based on, among others, on the project of the Polish Hydrogen Strategy, which is important for the further development of research topics and cooperation in this field. Conclusions: For the energy sector that processes available forms of energy, hydrogen is probably a good choice for the future. It can be an alternative to natural gas in providing backup capacity for renewable energy sources that produce energy dependent on weather conditions (i.e. sun and wind). Hy- drogen, which has the advantage of high energy density, is also a good tool for storing renewable energy and for transmitting and distributing renewable energy over long distances. Due to this, green energy from regions of the world with high insolation and wind energy, such as Australia, Latin America or North Africa, could be transferred over long distances (taking into account losses in energy networks it would be a much more economical solution). It would not require high-cost investments in new infrastructure. The article deals with the aspects relating to all parts of the value chain – production, transmission, storage and use of hydrogen, taking into account the legal conditions at the national (Polish Hydrogen Strategy) and the EU level, and proposing sustainable support systems and measurable goals. Keywords: green hydrogen, synthetic fuel, renewable energy, solar fuel, hydrogen Article type: review article

Sign in / Sign up

Export Citation Format

Share Document