scholarly journals Effective Laboratory Method of Chromite Content Estimation in Reclaimed Sands

2016 ◽  
Vol 16 (3) ◽  
pp. 162-166
Author(s):  
Z. Ignaszak ◽  
J-B. Prunier
Keyword(s):  
Quartz Sand ◽  
Permanent Magnets ◽  
Separation Efficiency ◽  
Original Method ◽  
Laboratory Method ◽  
Current Ratio ◽  
Moulding Sand ◽  
Chemical Hardening ◽  
And Control ◽  
Production Conditions

Abstract The paper presents an original method of measuring the actual chromite content in the circulating moulding sand of foundry. This type of material is applied for production of moulds. This is the case of foundry which most frequently perform heavy casting in which for the construction of chemical hardening mould is used, both the quartz sand and chromite sand. After the dry reclamation of used moulding sand, both types of sands are mixed in various ratios resulting that in reclaimed sand silos, the layers of varying content of chromite in mixture are observed. For chromite recuperation from the circulating moulding sand there are applied the appropriate installations equipped with separate elements generating locally strong magnetic field. The knowledge of the current ratio of chromite and quartz sand allows to optimize the settings of installation and control of the separation efficiency. The arduous and time-consuming method of determining the content of chromite using bromoform liquid requires operational powers and precautions during using this toxic liquid. It was developed and tested the new, uncomplicated gravimetric laboratory method using powerful permanent magnets (neodymium). The method is used in the production conditions of casting for current inspection of chromite quantity in used sand in reclamation plant.

scholarly journals A Laboratory Method to Measure Skin Surface Staining by Cigarette Smoke, Tobacco Heating Products and E-Cigarettes

2021 ◽  
Vol 30 (4) ◽  
pp. 158-166
Author(s):  
Annette Dalrymple ◽  
Emma-Jayne Bean ◽  
Jesse Thissen ◽  
Holger Behrsing ◽  
Steven Coburn ◽  
...  
Keyword(s):  
Cigarette Smoke ◽  
Skin Surface ◽  
Laboratory Method ◽  
Porcine Skin ◽  
Skin Sample ◽  
Side Stream ◽  
Air Control ◽  
And Control ◽  
Skin Samples

Summary Exhaled or side-stream cigarette smoke (CS) may visually stain a consumer's skin over time. Tobacco heating products (THPs) and e-cigarettes (ECs) have reduced staining potential because they do not produce side-stream aerosols and their exhaled aerosols have significantly reduced levels of toxicants, particles and odour. Here we assess discolouration of porcine skin in vitro after exposure to particulate matter (PM) or aerosols from CS (3R4F), two THPs (glo and glo sens) and an EC (iSwitch Maxx). PM was prepared by capturing aerosols on Cambridge filter pads and eluting with dimethyl sulfoxide (DMSO). Abattoir-obtained porcine skin samples were incubated with PM or DMSO control at 37 °C between 0 and 6.0 h. For aerosol assessment, porcine skin samples were exposed to between 50 and 400 puffs of the products, or air control, using a smoking machine. Colour profiles and staining levels of each skin sample were measured at different timepoints and puff thresholds using a spectrophotometer. Staining increased with time and dose, the greatest changes being observed following exposure to aerosols and PM from CS. THP, EC and control values were significantly different from CS after 0.5 h exposure to PM or 50 puffs of aerosols. The minimal staining induced by THPs and EC was comparable to controls. These data suggest that THPs and ECs could offer hygiene benefits to consumers who switch from smoking cigarettes. Further studies are required to assess the longer-term effects of THPs and ECs on skin discoloration. [Contrib. Tob. Nicotine Res. 30 (2021) 158–166]

scholarly journals New Type of Linear Magnetostrictive Motor Designed for Outer Space Applications, from Concept to End-Product

Actuators ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 266
Author(s):  
Lucian Pîslaru-Dănescu ◽  
Alexandru-Mihail Morega ◽  
Rareş-Andrei Chihaia ◽  
Ionel Popescu ◽  
Mihaela Morega ◽  
...  
Keyword(s):  
Permanent Magnets ◽  
Fuel Injection ◽  
Outer Space ◽  
Rocket Engines ◽  
Space Applications ◽  
Power Sources ◽  
Pulse Width Modulated ◽  
Power And Control ◽  
Technical Solutions ◽  
And Control

The use of the linear magnetostrictive motor (LMM) in outer space, in the absence of Earth’s gravitational field and where extreme temperatures manifest, involves innovative technical solutions that result in significant construction changes. This paper highlights these constructive changes and presents the mathematical modeling followed by the numerical simulation of different operating regimes of LMM. The novelty of the design resides in using a bias coil instead, in addition to permanent magnets, to magnetize the magnetostrictive core and pulse width modulated (PWM) power sources to control the two coils of the LMM (bias and activation). The total absorbed current is less than 2 A, which results in the reduction of Joule losses. Moreover, a PWM source is provided to power and control a set of three Peltier elements aimed at cooling the device. The experiments validate the design of the LMM, which elicits it to power and control devices that may modulate fuel injection for rocket engines or for machines used to adjust positioning on circumterrestrial orbits.

Design and control of the miniature maglev using electromagnets and permanent magnets in magnetic levitation system

ICCAS 2010 ◽  
2010 ◽  
Author(s):  
Jeong-Min Jo ◽  
Young-Jae Han ◽  
Chang-Young Lee ◽  
Bu-Byung Kang ◽  
Kyung-Min Kim ◽  
...  
Keyword(s):  
Permanent Magnets ◽  
Magnetic Levitation ◽  
Levitation System ◽  
Magnetic Levitation System ◽  
And Control

Superconductive Property and Microstructure of MgB2 Particle-Dispersed Aluminum Based Composite Materials

2010 ◽  
Vol 654-656 ◽  
pp. 2759-2762
Author(s):  
Manabu Mizutani ◽  
Kenji Matsuda ◽  
Kazuya Makino ◽  
Katsuhiko Nishimura ◽  
Tokimasa Kawabata ◽  
...  
Keyword(s):  
Composite Materials ◽  
Control Volume ◽  
Superconducting Magnets ◽  
Three Dimensional ◽  
Original Method ◽  
Superconducting Transition ◽  
Superconducting Wires ◽  
Al Composite ◽  
The Matrix ◽  
And Control

Superconducting wires have been applied for the fabrication of superconducting magnets in nuclear magneto-resonance (NMR), Magneto-resonance imaging (MRI) and so on. MgB2 has the highest critical temperature of superconducting transition (TC39K) among intermetallic compound superconductive materials. This means that MgB2 Superconductive wire doesn’t need expensive liquid He for cooling. We used the original method of the three-dimensional penetration casting (3DPC) in this laboratory to fabricate the MgB2/Al composite. Our 3DPC method for fabricating composite materials can disperse particles in the matrix homogenously without any aggregation and control volume fractions of composites within the range of 4 – 40%, even when particle size is less than 1 m. Thus, these composite materials can be processed by machining, extrusion and rolling. In the composite material we made, MgB2 particles dispersed to the Al matrix uniformly. The TC was determined by electrical resistivity and magnetization to be about 37 – 39K. We succeeded in extruding MgB2/Al composite billet to 1mm wire. Microstructures of these samples have been confirmed by SEM method. MgB2/Al composite billet and extruded wire were showed there no cracks inside the materials.

Modeling and Control of Proportional Valve with Synchronous Motor

2015 ◽  
Vol 220-221 ◽  
pp. 457-462 ◽  
Author(s):  
Andrzej Milecki ◽  
Dominik Rybarczyk
Keyword(s):  
Permanent Magnets ◽  
Dead Zone ◽  
Flow Characteristics ◽  
Synchronous Motor ◽  
Hydraulic Actuator ◽  
Servo Drive ◽  
Proportional Valve ◽  
Modeling And Control ◽  
Basic Characteristics ◽  
And Control

The paper describes the research results of modeling and control of proportional valve with synchronous motor type PMSM (Permanent Magnets Synchronous Motor). In the paper, a simulation model of the proposed valve was developed and described. The model included the square root flow characteristics, nonlinearity of the hydraulic actuator, valve dead zone and saturation of the flow. The study included the investigations of the basic characteristics, such as valve flow characteristic and step responses. In order to determine the basic parameters of the valve, the test stand was built, on which the new valve and the servo drive with this valve were tested. A servo drive control system was based on PLC with touch panel and inverter module. In the paper, the chosen investigations results of the valve and the servo drive system are presented and shortly discussed.

scholarly journals ORTHODONTIC TREATMENT WITH Nd-Fe-B MAGNETS

2020 ◽  
Vol 3 ◽  
pp. 54-62
Author(s):  
Valerii Kutsevlyak ◽  
Vladyslav Starikov ◽  
Volodymyr Samofalov ◽  
Vadym Starikov
Keyword(s):  
Corrosion Resistance ◽  
Permanent Magnets ◽  
Mutual Influence ◽  
Electrochemical Corrosion ◽  
Magnetic Interaction ◽  
Original Method ◽  
Physiological Solution ◽  
Protective Oxide ◽  
Corrosion Properties ◽  
Interaction Forces

The aim. The development of methodology for experimental and theoretical assessment of interaction forces between magnets in an orthodontic apparatus, the test of corrosion resistance of protective oxide and nitride coatings deposited on Nd-Fe-B magnets surface. Materials and methods. The Nd-Fe-B permanent magnets with saturation magnetization Ms≈1100 G and bilayer ZrN / ZrO2 coatings were used. To experimental measure of interaction forces between magnets the device was assembled on the base of analytical balance. The distance between the magnets was varied using non-magnetic plates. The ZrO2 and ZrN coatings have been analyzed for their corrosion properties in 0.9 % NaCl quasi-physiological solution. Results. An original method was proposed for calculating of magnetic interaction forces for materials with high magnetic anisotropy, which has good agreement with experimental measurement of forces. The theoretical model takes into account the size of the magnets and the mutual influence of their opposite faces. An increase of corrosion resistance of magnetic materials can be provided by zirconium oxide or nitride compounds, which contribute to inhibition of electrochemical corrosion of Nd-Fe-B magnets. Conclusions. A method for calculating of interaction forces between permanent magnets, which are used for correction of malocclusion in orthodontic, has been developed. The passivation of the Nd-Fe-B permanent magnets surface can be achieved by applying of bilayer ZrN / ZrO2 coating.

scholarly journals Design and Control of Field-Free Region Using Two Permanent Magnets for Selective Magnetic Hyperthermia

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 96094-96104 ◽  
Author(s):  
Armando Ramos Sebastian ◽  
Se Hwan Ryu ◽  
Haye Min Ko ◽  
Sung Hoon Kim
Keyword(s):  
Permanent Magnets ◽  
Magnetic Hyperthermia ◽  
Free Region ◽  
Field Free Region ◽  
And Control

IDENTIFICATION OF CONSTANTLY OPERATING MATHEMATICAL MODELS FOR QUALITY CONTROL OF UNIVERSITY STUDENTS’ KNOWLEDGE

10.12737/6079 ◽  
2014 ◽  
Vol 7 (2) ◽  
pp. 36-40
Author(s):  
Стародубцев ◽  
V. Starodubtsev ◽  
Фарафонов ◽  
A. Farafonov
Keyword(s):  
Quality Control ◽  
University Students ◽  
Mathematical Models ◽  
Original Method ◽  
Self Organization ◽  
Control Parameters ◽  
Effective Management ◽  
Knowledge Quality ◽  
The Face ◽  
And Control

Based on the theory of self-organization has developed an original method for identification of target functions students’ knowledge quality (SKQ) in the face of influencing factors uncertainty. The proposed system of external criteria for the models selection and control parameters allows to use the model for the effective management of the SKQ

Statistical modeling of significant diagnostic methods used in the treatment ofprimary forms of inflammatory periodontal diseases

10.12737/6674 ◽  
2014 ◽  
Vol 8 (1) ◽  
pp. 0-0
Author(s):  
Коровкина ◽  
A. Korovkina
Keyword(s):  
Inflammatory Diseases ◽  
Periodontal Diseases ◽  
Laboratory Method ◽  
Diagnostic Methods ◽  
Laser Doppler ◽  
Doppler Flowmetry ◽  
Clinical Methods ◽  
Microsoft Office ◽  
And Control ◽  
Initial Forms

In the article the ground of choice of meaningful methods of diagnostics is carried out on the basis of statistical analysis of data got during realization of photo-radiotherapy of initial forms of inflammatory diseases of paradontium. For this purpose inspection was conducted in 100 patients with gingivitis of easy and middle degree, periodontitis of easy degree by means of an offer algorithm of diagnostics – clinical and laboratory me-thods. The clinical methods were indexes, stomatoscopy and the laboratory method was the laser Doppler flow-metry. All patients were divided into 2 groups: basic (50 patients), which was applied photo-radiotherapy using a device Uzor-А-2К by power 18 W; and control (50 patients) to them medical treatment was recommended. Sta-tistical analysis of data, obtained in the study, was performed using SAS 9.3. and Microsoft Office 2010 - analysis of contingency tables and logistic regression.Significant diagnostic methods when conducting contin-gency tables were stomatoscope and the CPITN index. Laser Doppler flowmetry and significant parameters of microcirculation were determined using the method of logical regression. This is testified to optimally proposed algorithm for diagnosis of early forms of inflammatory periodontal diseases.

scholarly journals An Optimized Adsorbent Sampling Combined to Thermal Desorption GC-MS Method for Trimethylsilanol in Industrial Environments

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Jae Hwan Lee ◽  
Chunrong Jia ◽  
Yong Doo Kim ◽  
Hong Hyun Kim ◽  
Tien Thang Pham ◽  
...  
Keyword(s):  
Thermal Desorption ◽  
Semiconductor Industry ◽  
Mass Range ◽  
Laboratory Method ◽  
Semiconductor Wafer ◽  
Satisfactory Precision ◽  
Method Optimization ◽  
And Control ◽  
Wafer Manufacturing ◽  
Dual Bed

Trimethylsilanol (TMSOH) can cause damage to surfaces of scanner lenses in the semiconductor industry, and there is a critical need to measure and control airborne TMSOH concentrations. This study develops a thermal desorption (TD)-gas chromatography (GC)-mass spectrometry (MS) method for measuring trace-level TMSOH in occupational indoor air. Laboratory method optimization obtained best performance when using dual-bed tube configuration (100 mg of Tenax TA followed by 100 mg of Carboxen 569), n-decane as a solvent, and a TD temperature of 300°C. The optimized method demonstrated high recovery (87%), satisfactory precision (<15% for spiked amounts exceeding 1 ng), good linearity (R2=0.9999), a wide dynamic mass range (up to 500 ng), low method detection limit (2.8 ng m−3for a 20-L sample), and negligible losses for 3-4-day storage. The field study showed performance comparable to that in laboratory and yielded first measurements of TMSOH, ranging from 1.02 to 27.30 μg/m3, in the semiconductor industry. We suggested future development of real-time monitoring techniques for TMSOH and other siloxanes for better maintenance and control of scanner lens in semiconductor wafer manufacturing.

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