The impact of thermal degradation on electrical machine winding insulation

The paper reports a study of the impact of moisture and age of pellets, as well as an external condition, on the thermal degradation of the thermoplastic polyurethane elastomers. Because thermoplastic polyurethane elastomers are hydroscopic polymer, moisture will have a significant impact on thermal degradation. For determination of the effect of moisture and age were used the thermo gravimetric analysis, differential scanning calorimeter and ISO STN 871: Plastics. Determination of ignition temperature using a hot-air furnace.

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Characteristics and mechanical properties changes due to incorporation of aloe vera in polyethylene-based film

Scientific Research Journal ◽

10.24191/srj.v17i2.9837 ◽

2020 ◽

Vol 17 (2) ◽

pp. 61

Author(s):

Siti Fatma Abd Karim ◽

Junaidah Binti Jai ◽

Ku Halim Ku Hamid ◽

Abdul Wafi Abdul Jalil

Keyword(s):

Mechanical Properties ◽

Thermal Degradation ◽

Aloe Vera ◽

Functional Materials ◽

Chain Structure ◽

Substantial Effect ◽

Scanning Calorimetry ◽

Degradation Temperature ◽

And Performance ◽

The Impact

Non-degradable properties of polyethylene (PE) films due to long-chain structure cause increment of solid waste plastic. Many researchers, with different purposes, have studied the incorporation of functional materials to PE. Studying the impact of incorporation of aloe vera (AV) into PE films in terms of its characteristic and mechanical properties is the main objective of this paper. The films were prepared using melt-blending and hot press technique. The characterization assessed for the PE and PE-AV films were spectroscopy, crystalline phase, thermal analysis and performance of mechanical properties of the sample. The functional group detected in spectroscopy studied did not show any changes for PE film or PE with the presence of AV. Lower thermal degradation temperature (Td) obtained for PE-AV3 while others film found no significant changes of Td value and only one peak of thermal degradation occurred for all film. The same goes to the analysis obtained from differential scanning calorimetry (DSC) data. However, the crystalline structure displayed momentous peak changes for PE with AV. The highest tensile strength (TS) obtained by PE-AV3, at once developing highest value of Young’s modulus (YM), modulus of resilience (UE) and modulus of toughness (UT). A certain amount of AV has substantial effect on changing the polymeric structure especially improving the mechanical properties of PE film. Therefore, AV has potential to become an additive for developing a new partially degradable PE film.

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Smart-Sensors to Estimate Insulation Health in Induction Motors via Analysis of Stray Flux

Energies ◽

10.3390/en12091658 ◽

2019 ◽

Vol 12 (9) ◽

pp. 1658 ◽

Cited By ~ 7

Author(s):

Israel Zamudio-Ramirez ◽

Roque Alfredo Osornio-Rios ◽

Miguel Trejo-Hernandez ◽

Rene de Jesus Romero-Troncoso ◽

Jose Alfonso Antonino-Daviu

Keyword(s):

Induction Motors ◽

Early Stage ◽

Industrial Sector ◽

Smart Sensors ◽

Discrete Wavelet ◽

Electrical Machine ◽

Smart Sensor ◽

Time Frequency ◽

Essential Components ◽

Winding Insulation

Induction motors (IMs) are essential components in industrial applications. These motors have to perform numerous tasks under a wide variety of conditions, which affects performance and reliability and gradually brings faults and efficiency losses over time. Nowadays, the industrial sector demands the necessary integration of smart-sensors to effectively diagnose faults in these kinds of motors before faults can occur. One of the most frequent causes of failure in IMs is the degradation of turn insulation in windings. If this anomaly is present, an electric motor can keep working with apparent normality, but factors such as the efficiency of energy consumption and mechanical reliability may be reduced considerably. Furthermore, if not detected at an early stage, this degradation could lead to the breakdown of the insulation system, which could in turn cause catastrophic and irreversible failure to the electrical machine. This paper proposes a novel methodology and its application in a smart-sensor to detect and estimate the healthiness of the winding insulation in IMs. This methodology relies on the analysis of the external magnetic field captured by a coil sensor by applying suitable time-frequency decomposition (TFD) tools. The discrete wavelet transform (DWT) is used to decompose the signal into different approximation and detail coefficients as a pre-processing stage to isolate the studied fault. Then, due to the importance of diagnosing stator winding insulation faults during motor operation at an early stage, this proposal introduces an indicator based on wavelet entropy (WE), a single parameter capable of performing an efficient diagnosis. A smart-sensor is able to estimate winding insulation degradation in IMs using two inexpensive, reliable, and noninvasive primary sensors: a coil sensor and an E-type thermocouple sensor. The utility of these sensors is demonstrated through the results obtained from analyzing six similar IMs with differently induced severity faults.

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The Evolving E-cigarette: Comparative Chemical Analyses of E-cigarette Vapor and Cigarette Smoke

Frontiers in Toxicology ◽

10.3389/ftox.2020.586674 ◽

2020 ◽

Vol 2 ◽

Author(s):

Anthony Cunningham ◽

Kevin McAdam ◽

Jesse Thissen ◽

Helena Digard

Keyword(s):

Thermal Decomposition ◽

Thermal Degradation ◽

Benzoic Acid ◽

Cigarette Smoke ◽

Iron Alloy ◽

Decomposition Products ◽

Nickel Iron ◽

Degradation Reactions ◽

Nickel Iron Alloy ◽

The Impact

Background: E-cigarette designs, materials, and ingredients are continually evolving, with cotton wicks and diverse coil materials emerging as the popular components of atomisers. Another recent development is the use of nicotine salts in e-liquids to replicate the form of nicotine found in cigarette smoke, which may help cigarette smokers to transition to e-cigarettes. However, scientific understanding of the impact of such innovations on e-cigarette aerosol chemistry is limited.Methods: To address these knowledge gaps, we have conducted a comparative study analyzing relevant toxicant emissions from five e-cigarettes varying in wick, atomiser coil, and benzoic acid content and two tobacco cigarettes, quantifying 97 aerosol constituents and 84 smoke compounds, respectively. Our focus was the potential for benzoic acid in e-liquids and cotton wicks to form aerosol toxicants through thermal degradation reactions, and the potential for nickel–iron alloy coils to catalyze degradation of aerosol formers. In addition, we analyzed e-cigarette emissions for 19 flavor compounds, thermal decomposition products, and e-liquid contaminants that the FDA has recently proposed adding to the established list of Harmful and Potentially Harmful Constituents (HPHCs) in tobacco products.Results: Analyses for benzene and phenol showed no evidence of the thermal decomposition of benzoic acid in the e-cigarettes tested. Measurements of cotton decomposition products, such as carbonyls, hydrocarbons, aromatics, and PAHs, further indicated that cotton wicks can be used without thermal degradation in suitable e-cigarette designs. No evidence was found for enhanced thermal decomposition of propylene glycol or glycerol by the nickel–iron coil. Sixteen of the 19 FDA-proposed compounds were not detected in the e-cigarettes. Comparing toxicant emissions from e-cigarettes and tobacco cigarettes showed that levels of the nine WHO TobReg priority cigarette smoke toxicants were more than 99% lower in the aerosols from each of five e-cigarettes as compared with the commercial and reference cigarettes.Conclusions: Despite continuing evolution in design, components and ingredients, e-cigarettes continue to offer significantly lower toxicant exposure alternatives to cigarette smoking.

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Physicochemical, Thermal and Spectroscopic Characterization of the Energy of Consciousness Healing Treated Withania somnifera (Ashwagandha) Root Extract

Journal of Natural & Ayurvedic Medicine ◽

10.23880/jonam-16000296 ◽

2021 ◽

Vol 5 (1) ◽

pp. 1-10

Author(s):

Snehasis Jana

Keyword(s):

Weight Loss ◽

Thermal Degradation ◽

Control Sample ◽

Analytical Techniques ◽

Spectroscopic Characterization ◽

Root Extract ◽

Degradation Temperature ◽

Physico Chemical ◽

Treated Sample ◽

The Impact

Ashwagandha root extract is widely used in nutraceutical preparations due to its broad range of pharmacological activities. The objective of this study was to analyse the impact of Biofield Energy Treatment (The Trivedi Effect ® ) on the physico- chemical, thermal and spectral properties of ashwagandha root extract by using various analytical techniques. The sample of ashwagandha root extract was divided into two parts in which one part was kept untreated and called as control sample; while the other part was provided with the Consciousness Energy Healing Treatment remotely by the Biofield Energy Healer, Mr. Mahendra Kumar Trivedi and termed as Biofield Energy Treated sample. The study reported that the particle size values at d 10 , d 50 , d 90 , and D (4,3) in the Biofield Energy Treated sample was significantly decreased by 9.23%, 9.04%, 11.86%, and 10.59%, respectively compared with the control sample. Thus, the surface area of the treated sample was significantly increased by 10.75% compared to the control sample. The PXRD analysis showed that the control as well as the Biofield Energy Treated samples was amorphous in nature. The DSC analysis showed that the onset evaporation temperature and latent heat of vaporization were significantly altered by 2.18% and-10.29%, respectively in the Biofield Energy Treated sample compared with the control sample. The TGA analysis indicated the four step thermal degradation of both the samples. The 1 st , 2 nd , 3 rd , and 4 th steps of thermal degradation of the treated sample showed an alteration in the weight loss by -6.59%, 1.97%, -1.80%, and -8.65%, respectively along with 0.81% reduction in the total weight loss, compared with the control sample. Besides, the maximum thermal degradation temperature (T max ) in the control sample was observed at 234.17°C and 365.12°C for the two broad peaks, which was decreased by 1.73% and 0.82%, respectively compared to the control sample. The overall analysis suggests that the Energy of Consciousness Healing Treatment might enhance the solubility, absorption, and bioavailability profile of ashwagandha root extract along with altered thermal stability. Such altered properties might help in designing better pharmaceutical and nutraceutical preparations; thereby provide better therapeutic response against various diseases such as amnesia, arthritis, anxiety, cancer, impotence, neurodegenerative, and cardiovascular diseases.

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Effects of Organic Based Heat Stabilizer on Properties of Polyvinyl Chloride for Pipe Applications: A Comparative Study with Pb and CaZn Systems

Polymers ◽

10.3390/polym14010133 ◽

2021 ◽

Vol 14 (1) ◽

pp. 133

Author(s):

Chanchira Jubsilp ◽

Aran Asawakosinchai ◽

Phattarin Mora ◽

Duangporn Saramas ◽

Sarawut Rimdusit

Keyword(s):

Thermal Degradation ◽

Impact Strength ◽

Color Change ◽

Heat Stabilizer ◽

Degradation Behaviors ◽

Initial Color ◽

Rigid Pvc ◽

Isothermal Kinetic ◽

The Impact ◽

Positive Effect

In this paper, the effects of organic based stabilizers (OBS) are investigated and compared with traditional lead (Pb) and calcium zinc (CaZn) heat stabilizers regarding their processability, mechanical property, and thermal degradation behaviors in rigid PVC pipe applications. In addition, the effects of repeated processing cycles on the degree of gelation and the impact strength of the PVC/OBS, PVC/CaZn, and PVC/Pb are also examined. A repeated processing cycle of those three types of the heat stabilizers up to four cycles was found to increase the degree of gelation and proved no significant effect on the impact strength and heat resistance of the resulting PVC samples. The OBS showed a positive effect on preventing the autocatalytic-typed thermal degradation of the PVC samples. This leads to a longer retention time for the initial color change of the PVC/OBS compared to PVC/Pb or PVC/CaZn systems. This characteristic was related to a more uniform fusion behavior of the PVC/OBS, i.e., the lowest gelation speed and the longest fusion time. The non-isothermal kinetic parameter determined by the Kissinger and Flynn–Wall–Ozawa methods of the dehydrochlorination stage of the PVC/OBS was in satisfactory agreement and continued to compare with the PVC/Pb and PVC/CaZn systems. The results indicated that the OBS might decrease the dehydrochlorination rate of PVC, implying that PVC/OBS was more stable than PVC/Pb and PVC/CaZn systems.

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Improvement of Poly(Lactic Acid) Properties by Using Acrylonitrile-Butadiene Rubber and Polyethylene-g-Maleic Anhydride

Materials Science Forum ◽

10.4028/www.scientific.net/msf.972.178 ◽

2019 ◽

Vol 972 ◽

pp. 178-184

Author(s):

Sirirat Wacharawichanant ◽

Chawisa Wisuttrakarn ◽

Kasana Chomphunoi ◽

Manop Phankokkruad

Keyword(s):

Lactic Acid ◽

Thermal Properties ◽

Maleic Anhydride ◽

Thermal Degradation ◽

Impact Strength ◽

Mass Loss ◽

Poly Lactic Acid ◽

Butadiene Rubber ◽

Acrylonitrile Butadiene Rubber ◽

The Impact

This research prepared poly(lactic acid) (PLA) and PLA/acrylonitrile-butadiene rubber (NBR) blends before and after adding polyethylene-g-maleic anhydride with 3 wt% of maleic anhydride (PE-g-MA3) 3 phr. The effects of NBR and PE-g-MA3 on morphological, mechanical and thermal properties of PLA and PLA blends were discussed. The morphological analysis observed the two-phase morphology of PLA/NBR blends, and it was observed the cavities generated due to NBR phase detachment during sample fracture, and droplets of NBR phase at higher NBR content. The PE-g-MA3 addition could improve adhesion between PLA and NBR phases due to the decrease of cavities in PLA matrix and droplet size of NBR. The mechanical properties showed the impact strength and strain at break of PLA/NBR blends dramatically increased when the amount of NBR increasing. The addition of PE-g-MA3 significantly improved the impact strength of PLA/NBR blends. The thermal properties showed the NBR addition had effect slightly on the melting temperature of PLA/NBR blends. The filling of NBR and PE-g-MA3 greatly decreased the percent crystallinity of PLA more than two times. The thermal degradation of pure PLA and NBR proceeds by one step, while the thermal degradation process of PLA/NBR and PLA/PE-g-MA3 proceeds by two steps. Which the first step showed a large mass loss of PLA degradation and the second step showed a small mass loss of PE-g-MA and NBR degradation.

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The Use of Transfer Functions for Estimating the Impact son the Transformer Winding Insulation due to Resonance Overvoltages

Elektrichestvo ◽

10.24160/0013-5380-2019-1-23-29 ◽

2019 ◽

Vol 1 (1) ◽

pp. 23-29

Author(s):

Vasilii S. LARIN ◽

Keyword(s):

Transfer Functions ◽

Transformer Winding ◽

Winding Insulation ◽

The Impact

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Rice Husk Demineralization: Effect of Washing Solution on Its Physicochemical Structure and Thermal Degradation

Jurnal Kimia Sains dan Aplikasi ◽

10.14710/jksa.24.2.37-42 ◽

2021 ◽

Vol 24 (2) ◽

pp. 37-42

Author(s):

Hesti Wijayanti ◽

Iryanti Fatyasari Nata ◽

Chairul Irawan ◽

Rinny Jelita

Keyword(s):

Nitric Acid ◽

Thermal Degradation ◽

Rice Husk ◽

Strong Acid ◽

Weak Acid ◽

Raw Material ◽

Ftir Analysis ◽

Thermochemical Process ◽

And Behavior ◽

The Impact

Generally, biomass consists of various amounts of minerals. These minerals influence the biomass characteristics and behavior during their use in a thermochemical process such as pyrolysis. The conversion during pyrolysis and its final product will be affected. This research was carried out to study the impact of washing treatment in water and acid solutions on the rice husk as the raw material for pyrolysis. Also, the effect of acid strength (citric acid as the weak acid while nitric acid as the strong acid) and its concentration (1, 5, and 10 wt.%) was investigated. The results confirmed from the thermogravimetry (TGA/DTG) analysis, surface analysis (SEM), and spectra (FTIR) analysis describe the treatment using water caused less change on the rice husk surface structure and its thermal degradation. However, it seems hard to reduce the minerals (proved from XRF analysis). Meanwhile, the treatment using acids solution resulted in lower mineral composition than the rice husk without treatment. This result is more visible for demineralization using a 5 wt.% nitric acid solution. However, for a higher concentration (washing treatment using 10 wt.% solutions of nitric acid), the degradation on rice husk structure was more occurred.

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