scholarly journals Special Issue on Recent High Efficiency and Heavy Grinding. Grinding of High Performance Materials-On Titanium Alloys and Stainless Steels.

1992 ◽  
Vol 58 (4) ◽  
pp. 601-603
Author(s):  
Hideho TANAKA ◽  
Nobuo KUMAGAI
2022 ◽  
Vol 16 (1) ◽  
pp. 3-4
Author(s):  
Takazo Yamada ◽  
Kazuhito Ohashi ◽  
Hirofumi Suzuki ◽  
Akinori Yui

Demand for the high-precision and high-efficiency machining of hard ceramics, such as silicon carbide for semiconductors and hardened steel for molding dies, has significantly increased for optical and medical devices as well as for powered devices in automobiles. Certain types of hard metals can be machined by deterministic precision-cutting processes. However, hard and brittle ceramics, hardened steel for molds, and semiconductor materials have to be machined using precision abrasive technologies, such as grinding, polishing, and ultrasonic vibration technologies that use diamond super abrasives. The machining of high-precision components and their molds/dies using abrasive processes is very difficult due to their complex and nondeterministic natures as well as their complex textured surfaces. Furthermore, the development of new cutting-edge tools or machining methods and the active use of physicochemical phenomena are key to the development of high-precision and high-efficiency machining. This special issue features 11 research papers on the most recent advances in precision abrasive technologies. These papers cover the following topics: - Characteristics of abrasive grains in creep-feed grinding - Quantitative evaluation of the surface profiles of grinding wheels - ELID grinding using elastic wheels - Nano-topographies of ground surfaces - Novel grinding wheels - Grinding characteristics of turbine blade materials - Polishing mechanisms - Polishing technologies using magnetic fluid slurries - Application of ultrasonic vibration machining - Turning and rotary cutting technologies This issue is expected to help its readers to understand recent developments in abrasive technologies and to lead to further research. We deeply appreciate the careful work of all the authors, and we thank the reviewers for their incisive efforts.


2016 ◽  
Vol 11 (9) ◽  
pp. 764
Author(s):  
Lella Aicha Ayadi ◽  
Nihel Neji ◽  
Hassen Loukil ◽  
Mouhamed Ali Ben Ayed ◽  
Nouri Masmoudi

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1034
Author(s):  
Ching-Chien Huang ◽  
Chin-Chieh Mo ◽  
Guan-Ming Chen ◽  
Hsiao-Hsuan Hsu ◽  
Guo-Jiun Shu

In this work, an experiment was carried out to investigate the preparation condition of anisotropic, Fe-deficient, M-type Sr ferrite with optimum magnetic and physical properties by changing experimental parameters, such as the La substitution amount and little additive modification during fine milling process. The compositions of the calcined ferrites were chosen according to the stoichiometry LaxSr1-xFe12-2xO19, where M-type single-phase calcined powder was synthesized with a composition of x = 0.30. The effect of CaCO3, SiO2, and Co3O4 inter-additives on the Sr ferrite was also discussed in order to obtain low-temperature sintered magnets. The magnetic properties of Br = 4608 Gauss, bHc = 3650 Oe, iHc = 3765 Oe, and (BH)max = 5.23 MGOe were obtained for Sr ferrite hard magnets with low cobalt content at 1.7 wt%, which will eventually be used as high-end permanent magnets for the high-efficiency motor application in automobiles with Br > 4600 ± 50 G and iHc > 3600 ± 50 Oe.


2021 ◽  
Vol 12 (11) ◽  
pp. 1692-1699
Author(s):  
Ji Hye Lee ◽  
Jinhyo Hwang ◽  
Chai Won Kim ◽  
Amit Kumar Harit ◽  
Han Young Woo ◽  
...  

New polystyrene-based polymers with high π-extended hole transport pendants were synthesized to obtain a low turn-on voltage and high efficiency in solution-processed green TADF-OLEDs.


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3716
Author(s):  
Francesco Causone ◽  
Rossano Scoccia ◽  
Martina Pelle ◽  
Paola Colombo ◽  
Mario Motta ◽  
...  

Cities and nations worldwide are pledging to energy and carbon neutral objectives that imply a huge contribution from buildings. High-performance targets, either zero energy or zero carbon, are typically difficult to be reached by single buildings, but groups of properly-managed buildings might reach these ambitious goals. For this purpose we need tools and experiences to model, monitor, manage and optimize buildings and their neighborhood-level systems. The paper describes the activities pursued for the deployment of an advanced energy management system for a multi-carrier energy grid of an existing neighborhood in the area of Milan. The activities included: (i) development of a detailed monitoring plan, (ii) deployment of the monitoring plan, (iii) development of a virtual model of the neighborhood and simulation of the energy performance. Comparisons against early-stage energy monitoring data proved promising and the generation system showed high efficiency (EER equal to 5.84), to be further exploited.


2021 ◽  
Vol 7 (10) ◽  
pp. eabe8130
Author(s):  
Shangshang Chen ◽  
Xun Xiao ◽  
Hangyu Gu ◽  
Jinsong Huang

Perovskite-based electronic materials and devices such as perovskite solar cells (PSCs) have notoriously bad reproducibility, which greatly impedes both fundamental understanding of their intrinsic properties and real-world applications. Here, we report that organic iodide perovskite precursors can be oxidized to I2 even for carefully sealed precursor powders or solutions, which markedly deteriorates the performance and reproducibility of PSCs. Adding benzylhydrazine hydrochloride (BHC) as a reductant into degraded precursor solutions can effectively reduce the detrimental I2 back to I−, accompanied by a substantial reduction of I3−-induced charge traps in the films. BHC residuals in perovskite films further stabilize the PSCs under operation conditions. BHC improves the stabilized efficiency of the blade-coated p-i-n structure PSCs to a record value of 23.2% (22.62 ± 0.40% certified by National Renewable Energy Laboratory), and the high-efficiency devices have a very high yield. A stabilized aperture efficiency of 18.2% is also achieved on a 35.8-cm2 mini-module.


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