scholarly journals Establishment of the regularities of the polymer cover influence on the wood bio destruction

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Yu. V. Tsapko ◽  
O. Yu. Horbachova ◽  
S. M. Mazurchuk
Keyword(s):  
Weight Loss ◽  
Untreated Wood ◽  
Water Repellent ◽  
Maximum Weight ◽  
Polymer Shell ◽  
Wood Protection ◽  
Thermally Modified Wood ◽  
Wooden Structures ◽  
Modified Wood ◽  
Maximum Weight Loss

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.

Thermal Analysis of Plastic Contained Decorative Materials under Different Oxygen Concentration

2012 ◽  
Vol 550-553 ◽  
pp. 2786-2790
Author(s):  
Zhen Zhao ◽  
Feng Liu ◽  
Qiang Zhang ◽  
Lei Wang
Keyword(s):  
Thermal Analysis ◽  
Weight Loss ◽  
Oxygen Concentration ◽  
Integral Method ◽  
Combustion Process ◽  
Order Reaction ◽  
Maximum Weight ◽  
Ignition Point ◽  
First Order ◽  
Maximum Weight Loss

The combustion characteristics of decorative materials were studied by thermal analysis. The experiments were performed in three kind of oxygen concentration (7%, 14%, 21%), the heating rate were 15°C/min and 30°C/min respectively. The ignition point and maximum weight loss rated were analyzed. Based on the Coats-Redfern integral method, the results show that the combustion process were first order reaction.

Hygroscopic properties of thermally modified false Iroko [Antiaris toxicara (Lesch)]

2021 ◽  
Vol 18 (1) ◽  
pp. 51-57
Author(s):  
F.A. Faruwa ◽  
K. Duru
Keyword(s):  
Weight Loss ◽  
Dimensional Stability ◽  
Thermal Process ◽  
Colour Change ◽  
Wood Properties ◽  
Thermal Modification ◽  
Hygroscopic Properties ◽  
Different Temperatures ◽  
Thermally Modified Wood ◽  
Modified Wood

The study investigated the use of thermal modification to improve the hygroscopic properties of False Iroko [Antiaris toxicaria (Lesch)]. Samples of Antiaris toxicara Lesch wood were subjected to thermal modification in a furnace at temperatures of 160, 180 and 200°C for 30 and 60 minutes. Results showed that wood properties were improved with exposure to different temperatures. Subsequent to the thermal process, a colour change from pale yellow to darkish brown was observed progressively with increase in temperature, accompanied by a weight loss in the range of 12.08% to 23.67%. The outcome of these treatments resulted in a decrease in volumetric swelling and increase in dimensional stability of modified wood; this can be attributed to observed decrease in moisture intake. The thermal modification of Antiaris toxicara Lesch wood affected the dimensional stability properties. Thus, due to significant changes via modification carried out on the selected species which is classified as lesser utilized wood species, lesser utilized wood,Antiaristoxicara Lesch wood is recommended for use due to its efficient dimensional stability after modification . keywords:, Thermally modified wood ;False Iroko

Effects of Catalysts on Pyrolysis of Chlorella

2012 ◽  
Vol 433-440 ◽  
pp. 161-165
Author(s):  
Gui Ju Li ◽  
Ru Yu Zhao ◽  
Li Ping Bai
Keyword(s):  
Weight Loss ◽  
Loss Rate ◽  
Inorganic Compounds ◽  
Optimal Dosage ◽  
Maximum Weight ◽  
Weight Loss Rate ◽  
Two Factors ◽  
Catalytic Effects ◽  
Derivative Thermogravimetry ◽  
Maximum Weight Loss

Sodium compounds, Na2CO3，Na2SO4，NaCl, have been investigated with regard to their catalytic effects on chlorella pyrolysis by thermal analysis experiments. The influence of catalyst categories and dosage on chlorella pyrolysis were studied by the comparison and analysis of the TG（thermogravimetry）and DTG(derivative thermogravimetry) curves derived from tests of differential thermal balance of untreated chlorelal and chlorella mixed with three inorganic compounds of certain scale.The results show that the catalytic effect of the sodium compounds follow Na2CO3>Na2SO4>NaCl, Catalysts of Na2SO4，NaCl decreased the maximum weight loss rates while Na2CO3 increased them. And all the three additives lowered the pyrolysis temperature of chlorella，of which Na2CO3 made the highest conversion of chlorella pyrolysis. As the dosage of carbonate increased, the pyrolysis temperatures decreases and the maximum weight loss rate increases, but the conversion rate of chlorella pyrolysis decreases, considering these two factors, 5%wt is chosen as the optimal dosage of the catalysts.

scholarly journals Patterns and Predictors of Weight Loss with Exenatide Treatment in Overweight and Obese Women

2020 ◽  
Author(s):  
Jody Dushay ◽  
Eleftheria Maratos Flier ◽  
Robert E Gerzsten ◽  
Megan Rodgers ◽  
Brent Heineman ◽  
...  
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Placebo Group ◽  
Obese Women ◽  
Metabolomic Analysis ◽  
Maximum Weight ◽  
Dietary Counseling ◽  
Treatment Groups ◽  
Predictors Of Weight Loss ◽  
Maximum Weight Loss

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.

scholarly journals Establishment of moisture diffusion regularities through the polymer shell of thermally modified wood

2021 ◽  
Vol 12 (1) ◽  
pp. 41-47
Author(s):  
Yu. V. Tsapko ◽  
O. Yu. Horbachova
Keyword(s):  
Dimensional Stability ◽  
Experimental Studies ◽  
Treated Wood ◽  
Moisture Diffusion ◽  
Wood Products ◽  
Heating Process ◽  
Polymer Shell ◽  
Coating Application ◽  
Thermally Modified Wood ◽  
Modified Wood

An analysis of the process of thermal modification of wood, which was obtained by a controlled heating process, was done. The unique technological properties (durability, low hygroscopicity and dimensional stability) of thermomodified wood make it possible to use it in various scope. Due to the influence of temperature there are some chemical changes in the structures of the wood cell wall components (lignin, cellulose and hemicellulose). This leads to an increase in density, hardness, improved hydrophobicity (water repellency), thereby reducing their ability to absorb moisture and swell. The products absorb moisture gradually, are less prone to swelling and shrinkage, but still need the elastic coatings application. It is proved that heat-treated wood turns gray over time under the influence of sunlight, and therefore requires additional surface treatment with a coating. Additional protective substances application on the thermo-modified wood products surface promotes dimensional stability and protects against rapid weathering of the surface in open air conditions. The use of transparent coatings and oils does not protect the surface from discoloration during weathering. They are recommended for products are manufactured from thermomodified wood, which are operated away from direct sunlight and rain. The parameters of moisture penetration into wood are mathematically modeled on the basis of the moisture diffusion quasi-stationary equation through the polymer coating on the flat sample surface. The dynamics of moisture content changes in thermally modified wood by different schedules parameters has been experimentally studied. The obtained mathematical relations based on the experimental studies results make it possible to calculate the moisture diffusion coefficient in thermally modified wood in the presence of a polymer shell. It is established that the wax coating application on the surface of the product reduces the moisture diffusion process more than 10 times for surfaces treated at a temperature of 160 °C for 1 hour. That is, such products can be used on objects with high humidity.

Influence of Different Modifications on Bending Strength of Wood

2019 ◽  
Vol 800 ◽  
pp. 240-245
Author(s):  
Andis Antons ◽  
Dace Cīrule ◽  
Ingeborga Andersone ◽  
Anrijs Verovkins ◽  
Edgars Kuka
Keyword(s):  
Thermal Treatment ◽  
Bending Strength ◽  
Treatment Method ◽  
Thermal Modification ◽  
Wood Products ◽  
Bending Properties ◽  
Wood Protection ◽  
Thermally Modified Wood ◽  
Mild Temperature ◽  
Modified Wood

Despite intensive research in wood protection, no simple wood treatment method is available for satisfactory wood protection that could ensure appropriate strength and bio-resistance of wood products during their service life. The present study is a part of a project that is aimed to improve wood service properties by combining wood thermal treatment and impregnation with copper containing preservatives. The objective of the present study was to investigate the effect of conventional modifications (thermal modification at relatively mild temperature range (150 - 180°C) and impregnation) and double-treatments (impregnation after thermal treatment and vice versa) on the bending properties of birch (Betula spp.) and pine (Pinussylvestris L.) wood. Bending strength considerably decreased after thermal modification of wood, however MOE values generally did not significantly change. Moreover, impregnation had no effect on the bending properties for both unmodified and thermally modified wood specimens. For double-treatment in which impregnation was carried out before thermal modification no changes in bending strength were observed comparing to thermally modified wood. However, MOE values of these specimens were 10 % for birch and 19 % for pine smaller comparing to just thermally modified wood. The results of double-treatment tests imply that, regarding wood bending properties, wood impregnation after thermal modification is more appropriate.

scholarly journals Weight Loss during Calcination and Sintering Process of Na0.5Bi0.5TiO3–Bi1/2(Mg2/3Nb1/3)O3 Composite Lead-Free Piezoelectric Ceramics

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 676
Author(s):  
Syed Ali Afzal ◽  
Fayaz Hussain ◽  
Sajid Hussain Siyal ◽  
Muhammad Sufyan Javed ◽  
Muhammad Saleem ◽  
...  
Keyword(s):  
Weight Loss ◽  
Sintering Temperature ◽  
Perovskite Phase ◽  
Minimum Weight ◽  
Processing Technique ◽  
Maximum Weight ◽  
Low Frequencies ◽  
Holding Period ◽  
Maximum Loss ◽  
Maximum Weight Loss

(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.

scholarly journals STADY OF SURFACE TENSION OF MODIFIED WOOD

2021 ◽  
Author(s):  
Nataliya Khodosova ◽  
A. Dmitrenkov ◽  
V. Zayats
Keyword(s):  
Surface Tension ◽  
Liquid Drop ◽  
Metal Salt ◽  
Wood Flour ◽  
Untreated Wood ◽  
Water Repellent ◽  
Birch Wood ◽  
Drying Time ◽  
Coniferous Wood ◽  
Modified Wood

The study of the surface tension of wood of various tree species impregnated with used sunflower oil was carried out. Samples of birch, pine and linden wood were used for oil treatment. Impregnation of wood materials was carried out by the method of “hot-cold baths”. As an impregnating material, used refined fryer oil was used. In more detail, the paper examines the effect of an impregnating composition based on used fryer oil, with a filler and a desiccant on birch wood. Wood flour of coniferous wood species and a metal salt-based drier were used as a filler. The surface tension for all images was determined by the edge angle of wetting. For this purpose, the method of a liquid drop on the surface of a solid body was used. It was found that the impregnation of untreated wood with deep-frying oil leads to an increase in the surface tension on all samples, to a greater extent this is typical for pine wood. The introduction of a 1% siccative in the impregnating composition together with wood flour reduces the drying time and improves the water-repellent properties of birch wood.

scholarly journals Maternal Intravenous Fluids and Infant Weight

2012 ◽  
Vol 3 (2) ◽  
pp. 59-63 ◽  
Author(s):  
Robin Hirth ◽  
Tina Weitkamp ◽  
Alok Dwivedi
Keyword(s):  
Weight Loss ◽  
Birth Weight ◽  
Medical Records ◽  
Healthcare Providers ◽  
Intravenous Fluids ◽  
Maximum Weight ◽  
Cross Sectional ◽  
Relationship Of ◽  
The Relationship ◽  
Maximum Weight Loss

Healthcare providers typically use an infant’s weight loss in the first days of life as a measurement of effective feeding. Additional feeding volumes are often recommended when the infant reaches weight loss of seven to ten percent of their birth weight. This study examined the relationship of the amount of maternal intravenous fluids (IV) given during labor, and infant maximum weight loss during hospital admission. The method was a retrospective cross-sectional review of medical records for 186 healthy mothers and their infants who delivered at a Baby Friendly™ certified hospital in southwest Ohio. Maternal average IV mL per hour positively correlated with infant maximum weight loss.

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