Impact of thermoelectric cooling modules on the efficiency of a single-phase asynchronous machine

In this paper, the authors present the impact of thermoelectric cooling modules (TECMs) on the efficiency of a single-phase asynchronous machine. TECMs are used to lower the stator winding temperature and core temperature of the single-phase asynchronous machine. A similar effect might be possible by operating the asynchronous machine in a controlled lower temperature environment or by using other means of improved controlled cooling. An overview on the materials and method used during the experimental setup of the single-phase asynchronous machine with the TECMs is provided. Experimental results on the efficiency analysis, temperature analysis and equivalent circuit parameter analysis are provided. It is shown that the efficiency of the single-phase asynchronous machine can be increased by 4.44% when cooled by TECMs.

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PSII-2 Daily patterns for respiration rates and internal temperatures of heat stressed lactating sows with or without electronically controlled cooling pads

Journal of Animal Science ◽

10.1093/jas/skab235.589 ◽

2021 ◽

Vol 99 (Supplement_3) ◽

pp. 321-321

Author(s):

Jason R Graham ◽

Michaiah J Galvin ◽

Taylor L Jansen ◽

Tyler C Field ◽

Robert M Stwalley ◽

...

Keyword(s):

Single Phase ◽

Mixed Model ◽

Random Effect ◽

Regression Equations ◽

Controlled Cooling ◽

Study Objective ◽

Final Model ◽

Lactating Sows ◽

Periodic Regression ◽

The Impact

Abstract Lactating sows are especially sensitive to heat stress (HS) due to high metabolic demands resulting from milk output. Therefore, there is a need to develop effective cooling technologies that reduce the impact of HS on lactating sows. The study objective was to determine whether electronically controlled cooling pads (ECP) would allow sows to remain euthermic under HS conditions. Twelve multiparous (2.69 ± 0.85) lactating sows (265.4 ± 26.1 kg) and litters (11.4 ± 0.7 piglets/litter) were assigned to either a non-functional ECP (NECP; n = 6) or an ECP (n = 6), housed in farrowing crates, and tested over two repetitions. Sows were provided feed and water ad libitum and all sows were exposed to HS (28.27 ± 1.42°C nighttime to 35.14 ± 0.70°C daytime). Body temperature (TB), was measured hourly using vaginal implants, and respiration rate (RR) was measured in 30 min intervals from 0600 to 2100 hrs over 2 d representing mid- and late lactation. Mixed model periodic regression equations were fitted to the TB and RR to time. The final model for TB included the effect of replicate, random effect of sow, day of lactation as a covariate, single-phase sine and cosine variables for each treatment and 2-phase sine and cosine periodic regression variables. The final model for RR included the random effect of sow, effect of treatment, replicate, day of lactation, sleeping, and single-phase sine and cosine functions for each treatment. An interaction (P < 0.05) between treatment and sine or cosine was observed for TB. For RR there was no interaction for treatment and cosine (P = 0.07), but an interaction (P < 0.05; -9.94) was observed for sine. The significant treatment by wavelength interactions observed indicate a change in RR and TB patterns when sows are placed on ECPs.

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EFFECT OF MEAN ION SIZE AND SPATIAL SPIN DISORDERS FOR (La1-xYx)2/3Ca1/3MnO3 MANGANITES

International Journal of Modern Physics B ◽

10.1142/s0217979204026615 ◽

2004 ◽

Vol 18 (26) ◽

pp. 3451-3464 ◽

Cited By ~ 1

Author(s):

JINCANG ZHANG ◽

YUFENG ZHANG ◽

SHIXUN CAO ◽

CHAO JING

Keyword(s):

Single Phase ◽

Bond Angle ◽

Gradual Increase ◽

High Concentration ◽

Magnetic Studies ◽

Metal Insulator Transition ◽

Metal Insulator ◽

Average Ionic Radius ◽

Lower Temperature ◽

Ion Size

The structure and transport properties of perovskite ( La 1-x Y x)2/3 Ca 1/3 MnO 3 (0≤x≤0.3) systems are systematically investigated. It is found that all the specimens show a single-phase structure and reveal a direct relationship between the Curie temperature Tc and the average ionic radius <rA> of La site. With increasing Y 3+ doped content, the metal-insulator transition temperature T MI (M-I) shifts to lower temperature. While the relevant resistivity peak ρp is sharp increased, for the specimens with large doping content, x=0.3, it has enhanced eight orders of magnitudes larger than the non-doped samples (x=0.0). At high concentration area, that is to say, when x>0.1, magnetic studies show a gradual increase of antiferromagnetic interaction with an increase of x, ultimately leading to a spatial-spin disorders, that is, spin-glass-like state for x=0.2 and x=0.3 compounds at about 35 K. The results show that it has connected a reduction of Tc and an increase in magnetoresistance with a decrease in the microstructural Mn - O - Mn bond angle.

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Improved equivalent circuit parameter estimation of induction motor using H-G diagram and PSO

2017 IEEE Calcutta Conference (CALCON) ◽

10.1109/calcon.2017.8280772 ◽

2017 ◽

Cited By ~ 4

Author(s):

Diptarshi Bhowmick ◽

Mithun Manna ◽

Suparna Kar Chowdhury

Keyword(s):

Parameter Estimation ◽

Equivalent Circuit ◽

Induction Motor ◽

Circuit Parameter ◽

Equivalent Circuit Parameter

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A Review on Non-Asbestos Friction Materials: Material Composition and Manufacturing

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1150.22 ◽

2018 ◽

Vol 1150 ◽

pp. 22-42

Author(s):

Dinesh Shinde ◽

Kishore N. Mistry ◽

Suyog Jhavar ◽

Sunil Pathak

Keyword(s):

Composite Materials ◽

Material Properties ◽

Single Phase ◽

Friction Material ◽

Material Surface ◽

Surface Wear ◽

Friction Modifier ◽

Friction Materials ◽

Morphological Studies ◽

The Impact

The peculiar feature of friction materials to absorb the kinetic energy of rotating wheels of an automobile to control the speed makes them remarkable in automobile field. The regulation of speed cannot be achieved with the use of single phase material as a friction material. Consequently, the friction material should be comprised of composite materials which consist of several ingredients. Incidentally, the friction materials were formulated with friction modifier, binders, fillers and reinforcements. Due to its pleasant physical properties, asbestos was being used as a filler. Past few decades, it is found that asbestos causes dangerous cancer to its inhaler, which provides a scope its replacement. Several attempts have been made to find an alternative to the hazardous asbestos. The efforts made by different researchers for the impact of every composition of composite friction material in the field are reviewed and studied for their effect on the properties of friction material. Surface morphological studies of different friction material are compared to interpret the concept of surface wear and its correlation with material properties.

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Comparative kinetics of the alkali-catalyzed sunflower oil methanolysis with co-solvent under conventional and microwave heating with controlled cooling

Green Processing and Synthesis ◽

10.1515/gps-2017-0038 ◽

2018 ◽

Vol 7 (5) ◽

pp. 441-452

Author(s):

Biljana B. Beljic Durkovic ◽

Jelena D. Jovanovic ◽

Borivoj K. Adnadjevic

Keyword(s):

Microwave Heating ◽

Sunflower Oil ◽

Conventional Heating ◽

Controlled Cooling ◽

Pseudo First Order Reaction ◽

Reaction Rate Constants ◽

Cooling Conditions ◽

Exponential Factors ◽

The Impact ◽

Kinetics Of

Abstract The kinetics of the alkali-catalyzed transesterification of sunflower oil with methanol in the presence of co-solvent (TSMPC) were investigated. The kinetics curves of the alkali-catalyzed TSMPC, in the temperature range of 26°C–55°C, were measured for conventional heating (CH) and microwave heating with controlled cooling. The results showed that for both heating modes, the kinetics of the alkali-catalyzed TSMPC reaction can be described with the kinetic model of the pseudo first-order reaction with respect to the concentration of the triglycerides. The values of apparent reaction rate constants, activation energies, and pre-exponential factors are also calculated. The existence of a linear correlation (compensation effect) between the values of apparent kinetic parameters determined for CH and microwave heating with controlled cooling conditions is established. The results confirmed that the increase in the transesterification rate in the microwave heating with controlled cooling conditions is not caused by overheating nor by the existence of hotspots. The model of mechanism of the impact of microwave heating on the kinetics of transesterification is hereby proposed.

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Erosion Mechanism and Sensitivity Parameter Analysis of Natural Gas Curved Pipeline

Journal of Pressure Vessel Technology ◽

10.1115/1.4043011 ◽

2019 ◽

Vol 141 (3) ◽

Cited By ~ 2

Author(s):

Jie Zhang ◽

Hao Yi ◽

Zhuo Huang ◽

Jiadai Du

Keyword(s):

Natural Gas ◽

Wear Rate ◽

Shape Factor ◽

Great Influence ◽

Solid Particles ◽

Parameter Analysis ◽

Particle Collision ◽

Erosion Wear ◽

Gas Wells ◽

The Impact

With the deepening of natural gas exploitation, the problem of sand production in gas wells is becoming more and more serious, especially in high-yield gas wells. The solid particles in natural gas are very likely to cause erosion and wear of downstream pipelines and throttling manifolds, which makes the pipeline ineffective. Once the pipeline is damaged, the natural gas leaks, which may cause serious catastrophic accidents. In this paper, the impact of sand particles on the pipeline wall is predicted by the analysis of the research on bent and continuous pipeline combined with particle collision model. The parameters of different particles (particle shape factor, particle velocity, and particle diameter), different bent parameters (angle, diameter, and curvature-to-diameter ratio), and the influence of different continuous pipeline parameters (assembly spacing and angle) are explored on the erosion and wear mechanism of curved pipeline. The results show that the shape of the particles has a great influence on the wear of the curved pipeline. As the shape factor of the particles decreases, the wear tends to decrease. The bent area is subject to erosion changes as the particle parameters and piping parameters. The increase in pipeline diameter is beneficial to reduce the maximum and the average erosion wear rate. When the bent angle of the pipeline is less than 90 deg, the maximum erosion wear rate is basically the same. But when it is greater than 90 deg, it decreases with the increase in the bent angle. When the assembly angle of double curved pipeline is between 0 deg and 60 deg, the elbow is subject to severe erosion wear. At the same time, increasing the assembly spacing is beneficial to reduce the erosion wear rate. The research can provide a theoretical support for subsequent engineering applications.

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Comparative Analysis of Autoxidation of Haemoglobin

Journal of Experimental Biology ◽

10.1242/jeb.204.11.2029 ◽

2001 ◽

Vol 204 (11) ◽

pp. 2029-2033

Author(s):

Frank B. Jensen

Keyword(s):

Temperature Sensitivity ◽

Oxidation Rate ◽

Protective Role ◽

Yellowfin Tuna ◽

Histidine Residue ◽

River Lamprey ◽

Different Temperatures ◽

Lower Temperature ◽

The Impact

SUMMARY Autoxidation of oxyhaemoglobin (oxyHb) to methaemoglobin was measured at different temperatures in haemoglobin solutions from Atlantic hagfish, river lamprey, common carp, yellowfin tuna and pig. The aims were to evaluate the impact of the absent distal histidine in hagfish haemoglobin, the importance of oxyHb being either monomeric (hagfish and lamprey) or tetrameric (carp, tuna and pig) and to gain information on the temperature-sensitivity of autoxidation. The rate of autoxidation was lower in hagfish than in carp, yellowfin tuna and lamprey haemoglobins at any given temperature. Substitution of the distal histidine residue (His E7) with glutamine in hagfish haemoglobin was therefore not associated with an accelerated autoxidation, as might be expected on the basis of the normal protective role of His E7. Glutamine may have similar qualities to histidine and be involved in the low susceptibility to autoxidation. The low oxidation rate of hagfish haemoglobin, together with an oxidation rate of lamprey haemoglobin that did not differ from that of carp and yellowfin tuna haemoglobins, also revealed that autoxidation was not accelerated in the monomeric oxyhaemoglobins. Pig haemoglobin was oxidised more slowly than fish haemoglobins, demonstrating that fish haemoglobins are more sensitive to autoxidation than mammalian haemoglobins. The rate of autoxidation of hagfish haemoglobin was, however, only significantly greater than that of pig haemoglobin at high temperatures. Autoxidation was accelerated by rising temperature in all haemoglobins. Arrhenius plots of carp and yellowfin tuna haemoglobin revealed a break at 25°C, reflecting a lower temperature-sensitivity between 5 and 25°C than between 25 and 40°C.

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Influence of Soil Parameters on Detecting Voids behind a Tunnel Lining Using an Impact Echo Method

Applied Sciences ◽

10.3390/app9245403 ◽

2019 ◽

Vol 9 (24) ◽

pp. 5403

Author(s):

Meng Ma ◽

Rongning Cao ◽

Chao Niu ◽

Hougui Zhang ◽

Weining Liu

Keyword(s):

Element Model ◽

Tunnel Lining ◽

Parameter Analysis ◽

Soil Parameters ◽

Impact Echo ◽

Time Frequency ◽

Box Counting ◽

Box Counting Dimension ◽

Frequency Domains ◽

The Impact

Tunnel lining cavities are a common problem that may affect the bearing capacity of the tunnel-supporting structure, as well as the tunnel service life. The impact echo (IE) method can be used to detect voids behind tunnel linings. For a long tunnel, the surrounding rocks/soils are inhomogeneous and anisotropic, with parameters that vary with tunnel mileages. It is interesting to analyse whether alterations of the soil parameters affect the non-destructive test results. A laboratory experiment was performed in this study, in which voids behind a concrete plate, representing the tunnel lining, were designed to model the ineffective contact between the soil and the tunnel. The IE method was employed to inspect the existence of the void using different signal analysis approaches in the time, frequency and time–frequency domains. Furthermore, the fractal box-counting dimension was calculated for the purpose of quantitative evaluation. Different soil parameters and void sizes were considered, and finally, a finite element model was built and parameter analysis was accomplished using the software ABAQUS. The results demonstrated that: (1) A comprehensive analysis of vibration signals in the time, frequency and time–frequency domains was useful for identifying voids, while the box-counting dimension was useful for evaluating voids quantitatively. (2) Soils with large density and Young’s modulus differences had a certain influence on void detection, while those with large water content and Poisson’s ratio differences had little influence. (3) The box-counting dimension value was stable within the area where the void existed behind the tunnel; when the detection point was beyond twice that of the void dimension, it was difficult to locate the void.

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