scholarly journals The Choice of the Optimal Number of Discs in an MR Clutch from the Viewpoint of Different Criteria and Constraints

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6888
Author(s):  
Krzysztof Kluszczyński ◽  
Zbigniew Pilch
Keyword(s):  
Comparative Study ◽  
Mass Production ◽  
Manufacturing Process ◽  
Volume Ratio ◽  
Optimal Number ◽  
View Point ◽  
Mass Ratio ◽  
Active Materials ◽  
Materials Used ◽  
Mass Volume

This paper focuses on magnetorheological clutches (MR clutches) with a disc structure that can be designed as one-disc or multi-disc clutches (number of discs: N = 1, N > 2). The main goal of the paper is to compare their overall dimensions (lengths and radii), masses, volumes, and characteristic factors—torque per mass ratio and torque per volume ratio for MR clutches that develop the same given clutching torque Tc but differ in the number of discs (it is assumed that the number of discs of the primary member varies from one to four). This analysis develops charts and guidelines that will allow designers to choose the appropriate number of discs from the view point of various criteria, and with various limitations regarding geometry, geometric proportions, mass, volume, or restrictions on the amount of active materials used in the manufacturing process. The limitations on the active materials used are of particular importance in the case of mass production. Our methodology uses a comparative study, which can also be used when comparing design solutions of other electromechanical converters.

Preparation and Microstructure of Exfoliated Graphite with Large Expanding Volume by Two-Step Intercalation

2014 ◽  
Vol 852 ◽  
pp. 101-105 ◽  
Author(s):  
Ji Jin Zhao ◽  
Xiao Xia Li ◽  
Yu Xiang Guo ◽  
De Yue Ma
Keyword(s):  
Acetic Acid ◽  
Nitric Acid ◽  
Phosphoric Acid ◽  
Potassium Permanganate ◽  
Reaction Temperature ◽  
Volume Ratio ◽  
Exfoliated Graphite ◽  
Mass Ratio ◽  
Preparation Conditions ◽  
Mass Volume

Exfoliated graphite with large expanding volume (EV) was prepared by two-step intercalation, in which the mixture of nitric acid and phosphoric acid, and that of nitric acid and acetic acid were employed as intercalating agent step by step, and potassium permanganate was used as oxidant. Its preparation conditions were optimized by orthogonal experiment and parallel experiment, and its microstructure was analyzed by scanning electron microscope. The results show that the optimal preparation conditions for the first step intercalation are as follows: the mass-volume ratio of natural graphite (NG) to mixed acid is 1: 4, the volume ratio of nitric acid to phosphoric acid is 1: 2, the mass ratio of NG to potassium permanganate is 1: 0.2, and the reaction temperature is 20~30°C for 40~60 minutes. Those for the second step intercalation are as follows: the mass-volume ratio of acidized graphite (AG) to acetic acid is 1: 5, the mass-volume ratio of AG to nitric acid is 1: 1.5, the mass ratio of AG to potassium permanganate is 1: 0.15, and the reaction temperature is 20~30°C for 40~60 minutes, the EV is 450ml/g under the conditions listed above. The interlayers of graphite are fully opened and become a worm-like fluffy rope.

Preparation and Microstructure of Two Kinds of Exfoliated Graphite

2013 ◽  
Vol 706-708 ◽  
pp. 211-214
Author(s):  
Ji Jin Zhao ◽  
Xiao Xia Li ◽  
Yu Xiang Guo ◽  
Tong Sun ◽  
Sen Ma
Keyword(s):  
Potassium Permanganate ◽  
Volume Ratio ◽  
Graphite Powder ◽  
Exfoliated Graphite ◽  
Graphite Flake ◽  
Mass Ratio ◽  
Mixed Acid ◽  
Preparation Conditions ◽  
Orthogonal Experiments ◽  
Mass Volume

Two kinds of exfoliated graphite have been prepared from graphite flake and graphite powder, and their preparation conditions were respectively optimized by orthogonal experiments and parallel experiments. The effect of graphite size on the characteristics of exfoliated graphite was researched. The microstructure of two kinds of exfoliated graphite was measured by SEM. The results show that the optimal preparation conditions for exfoliated graphite flake are as following: the mass-volume ratio of graphite to mixed acid is 1: 4, the volume ratio of nitric acid to phosphoric acid is 1: 2, the mass ratio of graphite to potassium permanganate is 1: 0.1, and the reaction temperature is 25°C. For exfoliated graphite powder, the optimal mass ratio of graphite powder to potassium permanganate is 1: 0.22, and the consumption of oxidant for exfoliated graphite powder is more than that for exfoliated graphite flake. The longitudinal expansion of graphite flake is more apparent than that of graphite powder and leads to a worm-like fluffy rope.

Emerging Techniques for the Characterization of Nano-Mechanical Properties of Integrated Circuit Components

2008 ◽  
Author(s):  
Nicholas Randall ◽  
Rahul Premachandran Nair
Keyword(s):  
Mechanical Properties ◽  
Quality Control ◽  
Integrated Circuits ◽  
Integrated Circuit ◽  
Manufacturing Process ◽  
Solder Bumps ◽  
Initial Work ◽  
Circuit Components ◽  
Materials Used

Abstract With the growing complexity of integrated circuits (IC) comes the issue of quality control during the manufacturing process. In order to avoid late realization of design flaws which could be very expensive, the characterization of the mechanical properties of the IC components needs to be carried out in a more efficient and standardized manner. The effects of changes in the manufacturing process and materials used on the functioning and reliability of the final device also need to be addressed. Initial work on accurately determining several key mechanical properties of bonding pads, solder bumps and coatings using a combination of different methods and equipment has been summarized.

scholarly journals A Review on Enhancing the Antibacterial Activity of ZnO: Mechanisms and Microscopic Investigation

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Buzuayehu Abebe ◽  
Enyew Amare Zereffa ◽  
Aschalew Tadesse ◽  
H. C. Ananda Murthy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Antibacterial Activity ◽  
Field Emission ◽  
Volume Ratio ◽  
Electronic Configuration ◽  
Microscopic Investigation ◽  
Electron Microscopic ◽  
Active Materials ◽  
Scanning Electron

Abstract Metal oxide nanomaterials are one of the preferences as antibacterial active materials. Due to its distinctive electronic configuration and suitable properties, ZnO is one of the novel antibacterial active materials. Nowadays, researchers are making a serious effort to improve the antibacterial activities of ZnO by forming a composite with the same/different bandgap semiconductor materials and doping of ions. Applying capping agents such as polymers and plant extract that control the morphology and size of the nanomaterials and optimizing different conditions also enhance the antibacterial activity. Forming a nanocomposite and doping reduces the electron/hole recombination, increases the surface area to volume ratio, and also improves the stability towards dissolution and corrosion. The release of antimicrobial ions, electrostatic interaction, reactive oxygen species (ROS) generations are the crucial antibacterial activity mechanism. This review also presents a detailed discussion of the antibacterial activity improvement of ZnO by forming a composite, doping, and optimizing different conditions. The morphological analysis using scanning electron microscopy, field emission-scanning electron microscopy, field-emission transmission electron microscopy, fluorescence microscopy, and confocal microscopy can confirm the antibacterial activity and also supports for developing a satisfactory mechanism. Graphical abstract Graphical abstract showing the metal oxides antibacterial mechanism and the fluorescence and scanning electron microscopic images.

scholarly journals Are Biogenic and Pyrogenic Mesoporous SiO2 Nanoparticles Safe for Normal Cells?

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1427
Author(s):  
Katarzyna Solarska-Ściuk ◽  
Kinga Adach ◽  
Sylwia Cyboran-Mikołajczyk ◽  
Dorota Bonarska-Kujawa ◽  
Agnieszka Rusak ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Biological Effects ◽  
Mesoporous Silica Nanoparticles ◽  
Volume Ratio ◽  
Sio2 Nanoparticles ◽  
Amorphous Structure ◽  
Intracellular Ros ◽  
Materials Used ◽  
The Impact

Silicon dioxide, in the form of nanoparticles, possesses unique physicochemical properties (size, shape, and a large surface to volume ratio). Therefore, it is one of the most promising materials used in biomedicine. In this paper, we compare the biological effects of both mesoporous silica nanoparticles extracted from Urtica dioica L. and pyrogenic material. Both SEM and TEM investigations confirmed the size range of tested nanoparticles was between 6 and 20 nanometers and their amorphous structure. The cytotoxic activity of the compounds and intracellular ROS were determined in relation to cells HMEC-1 and erythrocytes. The cytotoxic effects of SiO2 NPs were determined after exposure to different concentrations and three periods of incubation. The same effects for endothelial cells were tested under the same range of concentrations but after 2 and 24 h of exposure to erythrocytes. The cell viability was measured using spectrophotometric and fluorimetric assays, and the impact of the nanoparticles on the level of intracellular ROS. The obtained results indicated that bioSiO2 NPs, present higher toxicity than pyrogenic NPs and have a higher influence on ROS production. Mesoporous silica nanoparticles show good hemocompatibility but after a 24 h incubation of erythrocytes with silica, the increase in hemolysis process, the decrease in osmotic resistance of red blood cells, and shape of erythrocytes changed were observed.

Haeckelite Phosphorous: An Emerging 2D Allotrope of Phosphorous for Potential Use in LIBs/SIBs

2021 ◽  
Author(s):  
Gayatree Barik ◽  
Sourav Pal
Keyword(s):  
2D Materials ◽  
Essential Feature ◽  
Volume Ratio ◽  
Promising Alternative ◽  
Materials Used ◽  
Potential Use

A large surface-to-volume ratio is an essential feature of 2D materials used in many potential electronic applications. This work proposed that the Haeckelite structured phosphorous can be another promising alternative...

scholarly journals A Comparative Review of Material Properties for Current and Future Dental Filling Nanomaterials

2021 ◽  
Vol 6 (4) ◽  
pp. 225-241
Author(s):  
Joshua Eisenstat ◽  
Dennis Gotthardt ◽  
Rebecca Assor ◽  
Liam Dempsey ◽  
Muhammad Hasibul Hasan
Keyword(s):  
Silica Nanoparticles ◽  
Antibacterial Properties ◽  
Volume Ratio ◽  
Dental Fillings ◽  
Dental Filling ◽  
Coated Nanoparticles ◽  
Comparative Review ◽  
Continued Use ◽  
Materials Used ◽  
Material Advantage

ABSTRACT Nanomaterials observe specialized properties relative to gross materials. Due to their small size, specialized nanomaterial properties include decreased reactivity, an increased surface area to volume ratio, heightened structural properties, and in some cases, antimicrobial and antibacterial effects. Current researchers are looking to use nanoparticle/nanomaterial properties to solve prevalent dental issues that cannot be addressed with traditionally used materials. This paper will serve as an extensive review of current nanomaterial applications as they pertain to dental fillings and dental filling processes. Comparative assessments of traditional materials used in dental fillings will be made as well as comparative assessments of currently used nanomaterials in dental fillings. Material comparisons are based on criteria pertaining to biocompatibility, toxicity, reactivity, cost, and antimicrobial/antibacterial properties. When comparing the three most currently used dental filling nanomaterials – Carbon-Based Nanotubes, Silica Nanoparticles and Silver-Coated Nanoparticles – it was observed that Silica Nanoparticles demonstrated the greatest material advantage and should be recommended for continued use. Issues regarding future developmental dental filling applications of graphene nanoparticles, organic nanoparticles and gold nanoparticles will also be discussed. Keywords: Nanomaterials, antibacterial, dental fillings, silica resins, biocompatibility.  

scholarly journals Susceptibility of earth-based construction materials to fungal proliferation: laboratory and in situ assessment

2019 ◽  
Vol 3 ◽  
pp. 140-149 ◽  
Author(s):  
Alexis Simons ◽  
Alexandra Bertron ◽  
Christophe Roux ◽  
Aurélie Laborel-Préneron ◽  
Jean-Emmanuel Aubert ◽  
...  
Keyword(s):  
Air Quality ◽  
Manufacturing Process ◽  
Building Materials ◽  
Construction Materials ◽  
Microbial Density ◽  
Microbial Proliferation ◽  
Materials Used ◽  
Ecological Construction ◽  
The Impact

The impact of building materials on the environment and the health of occupants is nowadays a priority issue. Ecological construction materials such as earthen materials are currently experiencing a regain of interest due to both ecological and economic factors. The microbial proliferation on indoor materials can induce a deterioration of the building air quality and lead to an increase of health risks for the occupants. The issue of indoor air quality raises questions about the use of earthen building materials and their possible susceptibility to fungal development. The microflora of earthen materials and their ability to grow on such support are indeed poorly studied. This study focused on the quantification of both bacterial and fungal microflora along the manufacturing process. The impact of extreme humidity, simulating a hydric accident, on microflora development was analyzed on the surface and inside earthen bricks. The initial microflora of these materials was dramatically reduced during the manufacturing process, especially after heat treatment for drying. Proliferation of remaining microorganisms was only observed under high humidity condition, in particular for earthen materials with vegetal aggregates. Moreover, in situ samplings were performed on naturally dried earthen materials used in buildings. The characterization of the microbial density revealed a higher microbial density than on manufactured specimens, while microbial concentration and detected taxa seemed mainly related to the room use and building history. These results provide a better understanding of microbial proliferation on these materials.

BiNem® manufacturing process for mass production

2003 ◽  
Vol 11 (3) ◽  
pp. 533 ◽  
Author(s):  
Jacques Angelé ◽  
Alain Boissier ◽  
Sylvain Lallemant ◽  
François Leblanc ◽  
Bertrand Pécout ◽  
...  
Keyword(s):  
Mass Production ◽  
Manufacturing Process
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