scholarly journals Resistance of Polylactide Materials to Water Mediums of the Various Natures

2021 ◽  
Vol 15 (2) ◽  
pp. 191-197
Author(s):  
Volodymyr Levytskyi ◽  
◽  
Diana Katruk ◽  
Andriy Masyuk ◽  
Khrystyna Kysil ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Diffusion Coefficient ◽  
Water Absorption ◽  
Alkaline Media ◽  
Process Stability ◽  
Additional Heat ◽  
Heat Treated ◽  
Acidic And Alkaline Media ◽  
Water Diffusion Coefficient

The influence of talc filler, its content, as well as an additional heat treatment and temperature on the regularities of polylactide materials water-absorption has been researched. Based on the obtained data, the water diffusion coefficient in polylactide materials and the activation energy of the diffusion process were determined. It was found that the process of water absorption by the filled and heat-treated materials based on polylactide proceeds slower and requires more activation energy of the process. Stability of the developed polylactide materials to acidic and alkaline media has been determined, in particular, it was found that the destruction of polylactide samples occurs faster in an alkaline medium than in an acidic one

scholarly journals Performance characteristics of polylactide-talc composites

2020 ◽  
Vol 3 (2) ◽  
pp. 163-168
Author(s):  
D.S. Katruk ◽  
◽  
Kh.V. Kysil ◽  
B.I. Kulish ◽  
A.S. Masyuk ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Diffusion Coefficient ◽  
Diffusion Process ◽  
Heat Resistance ◽  
Thermophysical Properties ◽  
Surface Hardness ◽  
Additional Heat ◽  
Thermomechanical Characteristics ◽  
Heat Treated

The influence of the filler – talc, its content, additional heat treatment and temperature on the physical-mechanical and thermophysical properties of polylactide materials, in particular on the surface hardness, heat resistance according to Vick and thermomechanical characteristics has been studied. The influence of filler and temperature on the resistance of polylactide materials to the action of the aqueous medium is revealed. The diffusion coefficient of water in polylactide materials and the activation energy of the diffusion process were determined. It was found that the process of water absorption by filled and heat- treated materials based on polylactide is slower and requires more activation energy of the process.

scholarly journals Water Resistance and Creep Behavior of Heat-Treated Moso Bamboo Determined by the Stepped Isostress Method

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1264
Author(s):  
Teng-Chun Yang ◽  
Tung-Lin Wu ◽  
Chin-Hao Yeh
Keyword(s):  
Heat Treatment ◽  
Water Absorption ◽  
Creep Behavior ◽  
Heat Treatment Temperature ◽  
Water Resistance ◽  
Absorption Efficiency ◽  
Treatment Temperature ◽  
Moso Bamboo ◽  
Phyllostachys Pubescens ◽  
Heat Treated

The influence of heat treatment on the physico-mechanical properties, water resistance, and creep behavior of moso bamboo (Phyllostachys pubescens) was determined in this study. The results revealed that the density, moisture content, and flexural properties showed negative relationships with the heat treatment temperature, while an improvement in the dimensional stability (anti-swelling efficiency and anti-water absorption efficiency) of heat-treated samples was observed during water absorption tests. Additionally, the creep master curves of the untreated and heat-treated samples were successfully constructed using the stepped isostress method (SSM) at a series of elevated stresses. Furthermore, the SSM-predicted creep compliance curves fit well with the 90-day full-scale experimental data. When the heat treatment temperature increased to 180 °C, the degradation ratio of the creep resistance (rd) significantly increased over all periods. However, the rd of the tested bamboo decreased as the heat treatment temperature increased up to 220 °C.

THE EFFECT OF HEAT TREATMENT OF MILK UPON THE HYDROLYZABILITY OF LACTOSE BY THE ENZYME LACTASE1

1970 ◽  
Vol 33 (9) ◽  
pp. 377-379 ◽  
Author(s):  
W. L. Wendorff ◽  
C. H. Amundson ◽  
N. F. Olson
Keyword(s):  
Heat Treatment ◽  
Salt Solution ◽  
Milk Protein ◽  
Lactose Hydrolysis ◽  
Additional Heat ◽  
Total Solids ◽  
Heat Treated ◽  
Dry Milk ◽  
Double Heat Treatment ◽  
Spray Dried

Heat treated, condensed skimmilk and nonfat dry milk (NDM) were treated with lactase enzyme obtained from Saccharomyces fragilis. The effect of heat treatment on lactose hydrolysis was determined. Forewarming treatments of 62.8, 68.3, 73.9, 79.5, and 85.0 C resulted in 17, 17, 100, 59, and 156 g, respectively, of lactose hydrolyzed. Concentrates with forewarming treatments of 62.8, 73.9, and 85.0 C for 30 min were given additional heat treatments of 62.8, 73.9, or 85.0 C for 20 min. Activity was lower in all concentrates given the double heat treatment, except those heated at 85.0 C for 20 min after forewarming at 62.8 and 73.9 C. These showed a substantial increase in lactose hydrolysis. Portions of each concentrate, spray dried and reconstituted to 30% total solids, exhibited the same effect on lactose hydrolysis as the original concentrates. Additional studies were conducted with whey and a 5% lactose plus milk salt solution. Results indicated that heating lactose in the presence of milk protein had a great effect on lactose hydrolysis.

scholarly journals Enhancement of Durability Properties and Drying Shrinkage of Heat-treated Oil Palm Shell Species High-strength Lightweight Concrete

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Mingkun Yew ◽  
Mingchian Yew ◽  
Lip Huat Saw ◽  
Siongkang Lim ◽  
Jing Hang Beh ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Compressive Strength ◽  
Water Absorption ◽  
Oil Palm ◽  
Lightweight Concrete ◽  
Drying Shrinkage ◽  
Durability Properties ◽  
Palm Shell ◽  
Oil Palm Shell ◽  
Heat Treated

In this study, the effects of heat-treated and non-treated oil palm shell (OPS) species (dura and tenera) are investigated on the slump, density and compressive strength of oil palm shell concrete (OPSC). Two different species of OPS coarse aggregates are subjected to heat treatment at 65 and 130 °C with the duration of 1 h. The results show that the workability of the OPSC increases significantly with an increase in temperature of heat-treated of the tenera OPS aggregates. It is found that the maximum achievable 28-days and 180-days compressive strength is 51 and 54 MPa, respectively. Furthermore, rapid chloride penetration tests (RCPT), porosity measurement and water absorption tests were performance to signify the effects of heat treatment on different OPS species lightweight concrete (LWC). The use of heat-treated OPS LWC induced the advantageous of reducing the permeability and capillary porosity as well as water absorption. The results showed that the ideal of heat treatment method has enhanced the performance of drying shrinkage. Hence, the findings of this study are of primary importance as they revealed that the heat treatment on OPS species LWC can be used as a new environmentally friendly method to enhance the durability properties and drying shrinkage of OPS LWC.

Water absorption behavior of heat-treated and untreated red balau saw dust/LDPE composites: Its kinetics and effects on mechanical properties

2018 ◽  
Vol 32 (10) ◽  
pp. 1408-1426 ◽  
Author(s):  
Ruth A Lafia-Araga ◽  
Aziz Hassan ◽  
R Yahya ◽  
N Abd Rahman ◽  
Fauzani Md Salleh
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Water Absorption ◽  
Water Immersion ◽  
Treated Wood ◽  
Untreated Wood ◽  
Thermoplastic Composites ◽  
Wood Composites ◽  
Saw Dust ◽  
Heat Treated

The hygroscopic nature of wood limits the use of wood thermoplastic composites (WTC) in outdoor industrial and domestic applications. To reduce this tendency, red balau saw dust was heat treated at 180 and 200°C for 1 h and compounded with Low Density Poly(ethylene) (LDPE) into 20 and 37 wt% and then molded into test specimens by injection molding. Samples were immersed in distilled water at room temperature for 4 months. Heat-treated wood composites showed remarkable water resistance relative to untreated ones. Wood composites made from wood treated at 180 and 200°C exhibited almost similar water absorption pattern. Reduced water absorption of heat-treated wood composites relative to untreated ones indicates that heat treatment has resulted in a degree of modification of the wood. Most of the composites displayed the Fickian mode of water absorption with n values close to 0.5. Also, the diffusion coefficient reduced with wood content in untreated wood composites due to interaction of water with the polar groups in wood through hydrogen bonding. Untreated wood composites exhibited poorer mechanical properties with water immersion as a result of degradation due to moisture. The mechanical properties of the heat-treated wood composites were not adversely affected with water absorption. Therefore, heat treatment can reduce the proneness to water absorption in WTCs and alleviate the detrimental effects on mechanical properties.

scholarly journals Effects of fermentation and heating on the functional properties of processed flour from African oil bean (Pentaclethra macrophylla benth) seeds

2013 ◽  
Vol 13 (60) ◽  
pp. 8249-8257
Author(s):  
ESD Osagie-Eweka ◽  
◽  
TH Alaiya
Keyword(s):  
Heat Treatment ◽  
Water Absorption ◽  
Functional Properties ◽  
Emulsion Stability ◽  
Absorption Capacity ◽  
Oil Absorption ◽  
Water Absorption Capacity ◽  
Emulsion Capacity ◽  
Heat Treated ◽  
African Oil Bean Seeds

A comparative study was conducted to determine the effects of heat treatment and fermentation on the functional properties of African oil bean ( Pentaclethra macrophylla: Benth ) seeds. The objective was to determine the nutritional benefits inherent therein, and the possible utilization of this plant food source as a complement in food formulation and improvement. The bean seed was broken to obtain the cotyledon, locally processed by fermentation and heat treatment, after which it was milled to obtain flour from the African oil bean. The control group of day 0 was not subjected to fermentation, but heat - treated and all other experimental groups (Day 1 - 7) subjected to fermentation and heating. The following selected physio -chemical properties were analyzed for the African oil bean seeds: water absorption capacity, oil absorption capacity and bulk densities were determined; the emulsion capacity and whipping ability were also determined. The oil absorption capacity range d from 0.66 - 1.26 g/ml; water absorption capacity, 0.76 - 1.32 g/ml; emulsion capacity, 33.33 - 64.67 g/ml, emulsion stability after one hour, 6.00 - 63.33 g/ml, bulk density, 0.40 - 0.49 g/g and whipping ability, 0.00 - 0.93 g/ml. The processing methods adopted (fermentation and heating) to improve on the functional properties of the African oil bean seeds significantly affected (p<0.05) the bulk density, whipping ability, emulsion stability and Stability after one hour of experimental samples fermented and heat treated (Day 1 - 7) compared to the Day 0 sample that was only heated while there was , however , no statistical significance recorded for the oil absorption capacity and water absorption capacity in experimental Day 1 - 7 compared to the control (Day 0) . The treatment, demonstrated improved functional properties of the African Oil bean seeds; likely to enhance the palatability of formulated foods. The treatment did not show significant improvement on the oil absorption capacity and water absorption capacity of t he bean ; however, there was enhanced oil and water functionality.

The differentiation of curd made from heated and raw milk

1973 ◽  
Vol 40 (1) ◽  
pp. 1-6 ◽  
Author(s):  
K. C. Guha ◽  
B. R. Roy
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Microbial Growth ◽  
Whey Proteins ◽  
Raw Milk ◽  
First Order ◽  
Heat Treated ◽  
Native Whey ◽  
Indian Law ◽  
Kinetics Of

SummarySince Indian law requires curds to be made from heat-treated milk, a means for distinguishing between curds made from raw and from heat-treated milks was sought. Curds contain whey proteins that are partly or completely denatured by heat treatment; the kinetics of the reaction are first order. The concentrations of native whey proteins in raw and heat-treated milks and in curds made from those milks were measured. No difference was found between the concentrations in heattreated milk and in the curds made from it, so that identical values were obtained for the half-life on heating and for the activation energy of denaturation. The acidity and microbial growth occurring during the production of curd did not affect the whey proteins. On electrophoresis, curd from raw milk gave a few whey protein bands, but curd from milk boiled for 10 min gave none, showing complete denaturation of the whey proteins.

scholarly journals Effect of cobalt oxide on the sintering and grain growth of Al2O3-YAG composite nanopowder

2010 ◽  
Vol 42 (3) ◽  
pp. 321-328 ◽  
Author(s):  
S.A. Hassanzadeh-Tabrizi ◽  
E. Taheri-Nassaj
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Cobalt Oxide ◽  
Grain Growth ◽  
Average Particle Size ◽  
Average Particle ◽  
Boundary Mobility ◽  
Grain Boundary Mobility ◽  
Heat Treated ◽  
Cobalt Oxide Doping

In the present study, the effect of cobalt oxide on the densification of Al2O3-YAG composite nanopowder was investigated. An amorphous nanopowder was synthesized and crystallized to Al2O3-YAG after heat-treatment via a solid-state reaction. The average particle size of heat-treated powder at 800?C was about 80 nm. Cobalt oxide improved the sintering rate of Al2O3-YAG composite nanopowders and promoted grain boundary mobility. Cobalt oxide doping increased the ratio of densification/grain growth rate. The activation energy for grain growth decreased from 590 to 485 kJ/mol by adding cobalt oxide to the composite nanopowder.

scholarly journals Enhancement of Durability Properties and Drying Shrinkage of Heat-treated Oil Palm Shell Species High-strength Lightweight Concrete

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Mingkun Yew ◽  
Mingchian Yew ◽  
Lip Huat Saw ◽  
Siongkang Lim ◽  
Jing Hang Beh ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Compressive Strength ◽  
Water Absorption ◽  
Oil Palm ◽  
Lightweight Concrete ◽  
Drying Shrinkage ◽  
Durability Properties ◽  
Palm Shell ◽  
Oil Palm Shell ◽  
Heat Treated

In this study, the effects of heat-treated and non-treated oil palm shell (OPS) species (dura and tenera) are investigated on the slump, density and compressive strength of oil palm shell concrete (OPSC). Two different species of OPS coarse aggregates are subjected to heat treatment at 65 and 130 °C with the duration of 1 h. The results show that the workability of the OPSC increases significantly with an increase in temperature of heat-treated of the tenera OPS aggregates. It is found that the maximum achievable 28-days and 180-days compressive strength is 51 and 54 MPa, respectively. Furthermore, rapid chloride penetration tests (RCPT), porosity measurement and water absorption tests were performance to signify the effects of heat treatment on different OPS species lightweight concrete (LWC). The use of heat-treated OPS LWC induced the advantageous of reducing the permeability and capillary porosity as well as water absorption. The results showed that the ideal of heat treatment method has enhanced the performance of drying shrinkage. Hence, the findings of this study are of primary importance as they revealed that the heat treatment on OPS species LWC can be used as a new environmentally friendly method to enhance the durability properties and drying shrinkage of OPS LWC.

scholarly journals The Effect of Heat Treatment on the Properties of Ultra High Strength Concrete

2015 ◽  
Vol 1 ◽  
pp. 22 ◽  
Author(s):  
Girts Bumanis ◽  
Nikolajs Toropovs ◽  
Laura Dembovska ◽  
Diana Bajare ◽  
Aleksandrs Korjakins
Keyword(s):  
Heat Treatment ◽  
Compressive Strength ◽  
Water Absorption ◽  
High Strength Concrete ◽  
High Strength ◽  
Early Age ◽  
Strength Gain ◽  
Strength Concrete ◽  
Heat Treated ◽  
Early Strength

The influence of heat treatment during curing process of ultra high strength concrete (UHSC) was researched. Four different heat treatment temperatures ranging from 50 to 200 °C were studied and compared to the reference temperature regime (20 °C).  Two series of heat treatment were applied: (a) at the early age of UHSC (3 days) and (b) after 27 days of standard curing regime in water at 20 °C. Concrete compressive strength was tested at the early age (4 days) and at the age of 28 days. The water absorption and water penetration under pressure were tested for heat treated and untreated UHSC specimens. SEM and XRD investigations of the studied samples were performed. UHSC with the strength of 123 MPa at the age of 28 days was tested at the standard curing conditions. Results indicate that early age curing at elevated temperature increases early compressive strength from 123 to 189% while at the age of 28 days the compressive strength was only 95 to 117% from reference and depends on the heat treatment regime. The heat treatment of UHSC at the age of 27 days was beneficial with regard to the strength development. Heat-treated UHSC provided compressive strength gain from 112 to 124% from reference. The water absorption for all UHSC specimens was from 2.6 to 3.2 wt.% and it was not affected by the heat treatment. The calcite was detected with XRD in heat treated UHSC samples which indicates the carbonization of Portlandite. This could explain the strength gain of heat-treated samples and the reason for slow compressive strength increase in the case of early heat treatment application. SEM images reveal dense structure and unreacted silica fume particles. The early heat treatment initiated high early strength but the strength of concrete reduced at the age of 28 days comparing to the early strength; therefore late heat application was beneficial for strength gain of the UHSC.

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