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2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Yu. V. Tsapko ◽  
O. Yu. Horbachova ◽  
S. M. Mazurchuk

The process of wood biological destruction is analyzed. It was found that the neglect of environmentally friendly means of bioprotection, leads to the destruction of wooden structures under the action of microorganisms. It is established that the study of wood protection conditions leads to the creation of new types of protective materials that reduce water absorption, as well as reduce the amount of substances that are the environment for the development of wood-destroying fungi. In this regard, a computational and experimental method for determining the proportion of destroyed material under the action of microorganisms using an antiseptic has been developed. The analysis of the results shows that the maximum weight loss in the case of biodegradation of untreated wood samples ranged from 7,6 to 16 %, and the weight loss of thermally modified wood samples did not exceed 3 %, antiseptic-hydrophobicizer – was less than 2 %. It was found that the protection when treated with thermally modified wood with oil-wax and azure exceeds (compared to untreated) more than 4 times in terms of biodegradation, and treatment with antiseptic-water repellent for untreated oil-wax and azure – more than 8 times. It should be noted that the presence of oil-wax and azure leads to blockage of the wood surface from the penetration of moisture or microorganisms. Therefore, the intensity of wood-destroying fungus development on the surface of various samples are differed. Obviously, such a mechanism of the protective coating influence is the factor regulating the process, which preserves the integrity of the object. On the experimental data basis and by modeling the equations, the microorganisms population dynamics in the volume of material and the function of increasing the number of dead organisms are derived. Thus, a polymer shell was created on the surface of the sample, which significantly reduced the penetration of microorganisms into the wood, and the weight loss of wood during biodegradation did not exceed 2,5 %. Additional application of protective substances on the surface increases the protection level of untreated pine wood by 72 %, thermomodified at 190 °C – 25 %, at 220 °C – by 37 %. Similar results for hornbeam wood – 60; 37 and 28 %, for oak – 50; 37 and 37 % respectively.


2021 ◽  
Vol 8 ◽  
Author(s):  
Jiaqian Li ◽  
Yaru Yang ◽  
Yunchao Xiao ◽  
Bolin Tang ◽  
Yaming Ji ◽  
...  

To improve the flame retardant properties of polyethylene terephthalate (PET), glucose-derived carbon nanospheres (CNSs) were synthesized and introduced into PET matrix. The thermal property and flame retardancy of CNSs/PET composites were thoroughly investigated. Results showed that CNSs displayed good flame-retardant performance for PET. When blended with only 1.0 wt.% of CNSs, CNSs/PET exhibited a limiting oxygen index (LOI) of 26.3 and a vertical combustion class of V-2, and its peak-heat release rate (pk-HRR) was reduced by 41.6%. Importantly, the initial decomposition temperature and the maximum weight loss temperature of CNSs/PET were 52°C and 199°C higher than those of PET, respectively. Furthermore, a condensed phase flame-retardant mechanism appeared in CNSs/PET, which formed a dense and thermally stable protective char layer during combustion. Overall, this study disclosed the flame-retardant potential and possible mechanism of CNSs for polyesters, which would benefit the development of carbon-based materials and flame-retardant polymers.


2021 ◽  
Vol 9 ◽  
Author(s):  
Ye Yuan ◽  
Yong He ◽  
Jiaxin Tan ◽  
Yongmeng Wang ◽  
Sunel Kumar ◽  
...  

In this study, the co-combustion characteristics of coal and biomass blends (20, 40, 60, 80, and 100 wt%) were investigated by thermogravimetric analysis. All the samples were operated under an oxidative atmosphere, with a heating rate of 20 C/min. The reaction stages, ignition and burnout temperature, maximum weight loss rate, and different combustion indices were determined. When the percentage of biomass in the blends was increased, the maximum mass loss rate was enhanced in the second region, and the ignition and burnout temperature was lowered, indicating the higher reactivity and better combustion performance of the samples. The comprehensive performance index presented an N shape with the increasing biomass blending ratio. Based on various combustion indices, 20% was an optimum percentage for the co-utilization of coal-biomass blends. A significant promoting interaction was observed between corn straw and rice straw blends, while inhibiting effects occurred between rice husk and coal. The kinetic parameters of the blends were evaluated by the Coats and Redfern method using the nth-order reaction model. The value of activation energy and the pre-exponential factor increased with the decreasing biomass percentage in the blends.


2021 ◽  
Vol 897 ◽  
pp. 45-50
Author(s):  
Salina Budin

Development of polylactic acid (PLA) composites using various filler have extensively being been in focus. One of the possible natural filler is eggshell (ES) which are abundantly available derived from food industry waste. This work attempted to investigate the effect of eggshell (ES) filler on the degradation of virgin-PLA and recycled-PLA. The virgin-PLA/ES composites and recycled-PLA/ES composites were prepared using solvent casting method. The content of eggshell filler varied in the range of 0 – 20 wt%. Degradation of virgin-PLA/ES composites and recycled-PLA/ES composites were evaluated by soil buried test. After soil buried for 10 weeks, the maximum weight loss for virgin-PLA/ES composites was 14 wt% which noted at the composition of 95 wt% virgin-PLA/5 wt% ES. Nevertheless, for recycled-PLA/ES composites, the maximum weight loss observed at the composition of 90 wt% recycled-PLA/ 10 wt% ES at the value of 21 wt%. However, further addition of eggshell filler content in PLA/ES composites led to lower weight loss. Hence, the degradation of recycled-PLA/ES composites were more accelerated as compared to virgin-PLA/ES composites. The results revealed the potential of eggshell waste as a bio-filler in PLA matrix.


2021 ◽  
Vol 7 (7) ◽  
pp. 3001-3006
Author(s):  
Chidiebere Anab-Atulomah ◽  
◽  
Ejikeme Nwachukwu ◽  

The bio-scouring of cotton using protease and pectinase produced from Bacillus subtilis was investigated. Protease and pectinase were produced from Bacillus subtilis in a liquid medium using the submerged fermentation technique. Both enzymes were purified, and their scouring potential was tested on raw cotton fabrics. Pectinase was more effective than protease under optimised conditions. The optimum scouring temperature for both enzymes was between 40 °C and 50 °C, with pectinase bio-scoured fabric showing 15.5% weight loss while protease bio-scoured fabric had 14.3% weight loss. The optimum pH for pectinase scouring was pH 9 with 14.8% weight loss in the fabric, while the optimum pH for protease scoured fabric was pH 7 with 12.3% weight loss in fabric. After 120 minutes of bio-scouring, maximum weight loss was recorded for both pectinase and protease treated fabrics. The application of protease and pectinase for cotton fabric scouring revealed that they could be used as bio-scouring agents to treat textile materials.


Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 676
Author(s):  
Syed Ali Afzal ◽  
Fayaz Hussain ◽  
Sajid Hussain Siyal ◽  
Muhammad Sufyan Javed ◽  
Muhammad Saleem ◽  
...  

(1 − x)(Na0.5Bi0.5)TiO3–xBi(Mg2/3Nb1/3)O3 ceramics with x = 0.00 mol.% (0BMN), 0.01 mol.% (1BMN), 0.03 mol.% (3BMN), and 0.05 mol.% (5BMN) were synthesized using a solid-state processing technique. The thermogravimetric analysis (TGA) of uncalcined samples up to 730 °C showed that the maximum weight loss was observed for 3BMN, whereas the minimum weight loss was attributed to the 0BMN sample. After that, calcination was performed at 800 °C for 4 h. The XRD of calcined samples showed the successful formation of the perovskite phase with no impurity phases. 1BMN and 3BMN samples showed some of the lattice strain; however, a morphotropic phase boundary (MPB) existed around x = 0.03 between the rhombohedral and tetragonal structure. The TGA of the green pellets showed weight loss up to the sintering temperature (1100 °C) and during the 3 h holding period. 5BMN showed the maximum weight loss up to sintering temperature, as well as during the holding period, whereas 0BMN displayed the minimum weight loss up to sintering temperature, as well as some weight gain during the holding period. The relative permittivity (εr) was maximum at low frequencies, but the addition of BMN improved the εr. The frequency dependence of dielectric loss (tanδ) showed that the maximum loss was observed for 3BMN at lower frequencies, and 5BMN showed the maximum loss at higher frequency among all samples.


Nutrients ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2116
Author(s):  
Xiao Wei Ma ◽  
Wei Qi Fan

This study aimed to evaluate jaundice outcomes of low-birthweight premature infants commenced on earlier versus later nutrient supplementation (80 mL/kg/day vs. 160 mL/kg/day; total fluid intake, F80 vs. F160). Demographics, feeding regimens, and clinical outcomes data were collected. Infant and maternal characteristics were similar. Earlier nutrient supplementation was associated with multiple improved jaundice outcomes: total (TSBR), unconjugated and conjugated (CSBR) serum bilirubin values (196 ± 46 vs. 228 ± 52, 184 ± 44 vs. 212 ± 50, 12 ± 4 vs. 16 ± 5, respectively, all p < 0.001); phototherapy (39% vs. 64%, p < 0.0001). % CSBR/TSBR ratio was similar between groups. For those on phototherapy, duration and median irradiance were similar. F80 infants experienced reduced: feeding intolerance (26.0% vs. 45.2%, p = 0.007); length of stay (16.0 ± 0.64 vs. 18.8 ± 0.74 days, p = 0.03), maximum weight loss as % birth weight (5% vs. 6%, p = 0.03); decrease in weight Z-score at 10 days (−0.70 ± 0.03 vs. −0.79 ± 0.03, p = 0.01). F80 infants regained birthweight earlier (10.0 ± 0.3 days vs. 11.5 ± 0.3 days, p < 0.0001) and had no differences in adverse clinical outcomes. We speculate that earlier nutrient supplementation improved jaundice outcomes due to enhanced excretion/elimination of bilirubin.


2020 ◽  
Author(s):  
Jody Dushay ◽  
Eleftheria Maratos Flier ◽  
Robert E Gerzsten ◽  
Megan Rodgers ◽  
Brent Heineman ◽  
...  

AbstractIn the medical management of obesity, treating physicians observe significant heterogeneity in responses to pharmacotherapy. Indeed one of the most important clinical questions in obesity medicine is whether we can predict how an individual will respond to a particular pharmacotherapeutic agent. The present study examines patterns and predictors of weight loss among overweight and obese women who demonstrated early robust response to twice daily exenatide treatment.182 women were assigned using single-blind randomization to either treatment with twice daily exenatide injections or to matched placebo injections with dietary counseling. Women who demonstrated > 5% weight loss after 12 weeks of treatment were deemed high responders and remained on study treatment for up to 52 weeks; women who lost < 5% body weight at 12 weeks were deemed low responders and stopped study treatment. We additionally characterized individuals who lost > 10% of body weight as super responders. Our primary outcome was change in body weight; secondary outcomes included changes in metabolic parameters including lipids, waist circumference, resting energy expenditure, and response to a meal tolerance test. We also performed an exploratory metabolomic analysis.Consistent with published literature, we observed individual heterogeneity in the weight loss response to exenatide and diet/placebo. Although there was no significant difference between treatment groups in the percentage of participants who achieved > 5% weight loss (56% of exenatide group and 76% of diet/placebo group), or those who achieved > 10% weight loss (43% of exenatide group and 55% of diet/placebo group), in both cases there was a trend toward a higher response rate in the group that received placebo with dietary counseling. In addition to achieving similar average weight loss, both treatment groups also demonstrated similar maximum weight loss. The range of maximum weight loss was greater in the diet/placebo group and there was more weight regain among individuals in the exenatide group compared to the diet/placebo group. In our exploratory metabolomic analysis, we observed lower baseline circulating cysteine concentrations in the exenatide responder group and we also found a trend toward higher baseline levels of serotonin, aminoisobutyric acid, anandamide, and sarcosine in the exenatide super responder group. We did not identify any metabolic predictors of weight loss in either the exenatide or the diet/placebo treatment group.


An industrial waste removal process plays main roles in all production industries, in this paper discussed about the sugar industry waste i.e. bagasse used as fuel along with coal in thermal power plant. After combustion of Coal-Bagasse, it produces bulk amount of ash and clay from the local fire brick manufacturers and expanded perlite from the thermal insulation powders suppliers. Coal-Bagasse ash, clay and perlite were performed to brick manufacturing. These three constituents with different ratios (10:5:1) on weight basis, mix properly with little addition of water for required plasticity. This mixture poured into moulds for required shape of sample (120mmx60mmx50mm) according to the laboratory requirements. Prepared samples were dried in atmosphere until the removal of wet content in samples. For final curing, dried samples heated in electrical furnace, at different temperature ranges. Scanning Electron Microscope with Energy Dispersive Spectrum (SEM-EDS) was performed to study the microstructures and chemical composition (on mass & weight basis) of samples, Thermo gravimetric-Differential Thermal Analysis (TG-DTA) to study the variation in mass of samples at different temperatures with respective time. The result shown maximum weight loss obtained at more quantity of coal, high compressive strength and low thermal conductivity at more amount of clay-bagasse ash.


2019 ◽  
Vol 103 ◽  
pp. 02004
Author(s):  
Vivian Beltrán ◽  
Laura V. Martínez ◽  
Andrés López ◽  
María F. Gómez

Thermal degradation and kinetic for biomass materials wood residues and Gorse (Ulex europaeus) have been evaluated under pyrolysis (N2) conditions, using a non-isothermal thermogravimetric method (TGA) from 25°C to 900°C at different heating rates of 10, 20, 30 and 40°C min-1. In DTG curves the temperature peaks at maximum weight loss rate changed with increasing heating rate. The maximum rate of weight loss (%s-1) was obtained at a heating rate of 40°C/min of 0,38 and 0,46 (%s-1) for wood residues and Gorse, respectively. Activation energy calculations were based on selected non-isothermal methods (Kissinger, FWO, KAS, and Starink). For Gorse, the energy activation was 195.41, 194.44, 214.39 and 179.42 kJmol-1 by Kissinger, FWO, KAS, and Starink methods, respectively. In the other hand, the energy activation for wood residues was 176.03, 221.75, 243.08 and 198.26 kJmol-1 by Kissinger, FWO, KAS, and Starink methods, respectively. The results showed that Gorse has a lower activation energy than wood residues, which represents a great potential to be used as a feedstock in thermochemical technologies. The Levelized Cost of Electricity (LCOE) was calculated for gasification of wood residues and Gorse, which was 186 and 169 USD/MWh, respectively.


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