scholarly journals THE EFFECT OF HYDROGEL DRESSING COPOLYMER POLI(VINYLPIRROLIDONE) (PVP) - k- CARRAGEENAN PREPARED BY RADIATION AND HEALING TIMES ON THE RADIUS REDUCTIONS BURN INJURIED OF WISTAR WHITE RAT

2010 ◽  
Vol 8 (2) ◽  
pp. 271-278
Author(s):  
Erizal Erizal
Keyword(s):  
Tensile Strength ◽  
Clinical Study ◽  
Aqueous Solutions ◽  
Water Absorption ◽  
Water Content ◽  
Wound Dressing ◽  
Chemical Properties ◽  
Physico Chemical ◽  
Time Observation ◽  
Sterilization Dose

The pre-clinical study of poly (vinyl pirrolidone) (PVP)-k- carrageenan hydrogel has been carried out. The aim of this study is to investigate the effect of hydrogel for healing burn injuried in the rats. The hydrogels were prepared by g-irradiation of aqueous solutions of 15 wt.-% PVP and 2 wt.-% k- carrageenan at a sterilization dose of 25 kGy. The physico-chemical properties of hydrogels were investigated. The results showed that the hydrogels suitable as candidate for wound dressing with gel fraction of 90 ± 5 (%), the water absorption was 4500 ± 55 (w/w), the water content was 83 ± 2 (%), tensile strength was 1,5 ± 0,1 kg/cm2 and adhesiveness was 0. The effect of the hydrogel as wound dressing was evaluated by attaching to a burn of the back skin of rats as a function of time observation. Advantages of the hydrogel were slightly faster rate of reducing radius diameter of injured burn skin, easy removal without damage to renewed skin.   Keywords: hydrogel, irradiation, copolymer, PVP, k carrageenan, diameter

scholarly journals The Simultaneous Removal of Zinc and Cadmium from Multicomponent Aqueous Solutions by Their Sorption onto Selected Natural and Synthetic Zeolites

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 343 ◽  
Author(s):  
Bożena Kozera-Sucharda ◽  
Barbara Gworek ◽  
Igor Kondzielski
Keyword(s):  
Aqueous Solutions ◽  
Low Cost ◽  
Environmental Pollutants ◽  
Chemical Properties ◽  
Simultaneous Removal ◽  
Physico Chemical ◽  
Synthetic Zeolites ◽  
Sorption Mechanisms ◽  
Synthetic Aluminosilicate ◽  
Natural And Synthetic

Natural and synthetic aluminosilicate minerals, in particular zeolites, are considered to be very useful in remediation processes, such as purification of waters polluted with heavy metals. That is due to their unique and outstanding physico-chemical properties, rendering them highly efficient, low-cost, and environmentally friendly sorbents of various environmental pollutants. The aim of this study was to examine the sorption capacity of four selected zeolites: A natural zeolite and three synthetic zeolites (3A, 10A, and 13X), towards zinc and cadmium present in multicomponent aqueous solutions, in relation to identified sorption mechanisms. It was stated that synthetic zeolites 3A and 10A were the most efficient in simultaneous removal of zinc and cadmium from aqueous solutions. Additionally, zeolite 10A was demonstrated to be the mineral best coping with prolonged pollution of water with those elements. The mechanism of sorption identified for tested minerals was physisorption.

Permanent physico-chemical properties of extremely diluted aqueous solutions of homeopathic medicines

Homeopathy ◽  
2004 ◽  
Vol 93 (3) ◽  
pp. 144-150 ◽  
Author(s):  
V. Elia ◽  
S. Baiano ◽  
I. Duro ◽  
E. Napoli ◽  
M. Niccoli ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Chemical Properties ◽  
Physico Chemical ◽  
Extremely Diluted Aqueous Solutions

scholarly journals Physico-Chemical Properties of Aqueous Solutions of Cn−1H2n−1OCH2COONa

1976 ◽  
Vol 49 (5) ◽  
pp. 1257-1259 ◽  
Author(s):  
Masakatsu Hato ◽  
K\={o}z\={o} Shinoda ◽  
T\={o}ru Miyagawa
Keyword(s):  
Aqueous Solutions ◽  
Chemical Properties ◽  
Physico Chemical

scholarly journals Influence of Polymer-Silicate Nucleator on the Structure and Properties of Polyamide 6

2020 ◽  
Vol 14 (4) ◽  
pp. 496-503
Author(s):  
Volodymyr Levytskyi ◽  
◽  
Andrii Masyuk ◽  
Diana Katruk ◽  
Rafał Kuzioła ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Crystallite Size ◽  
Softening Point ◽  
Surface Hardness ◽  
Chemical Properties ◽  
Polyamide 6 ◽  
Structure And Properties ◽  
Crystallinity Degree ◽  
Physico Chemical ◽  
Silicate Materials

Physico-chemical properties of developed nickel-containing modified silicate materials as the nucleators for composites based on polyamide 6 are presented. As it was established, additive of the nucleator modified by polyvinylpyrrolidone promotes the increase of crystallinity degree of polyamide 6 and the decrease of crystallite size. It was found that changes in the structure of the material cause the increase of its tensile strength, surface hardness and Vicat softening point.

scholarly journals Effect of Potassium Carbonate (K2CO3) on the Viscosity and Related Physico – Chemical Properties of Genger (Bombax costatum) Powder during Storage

2013 ◽  
Vol 1 (1) ◽  
pp. 77-82 ◽  
Author(s):  
D Gernah ◽  
P Gbakaan
Keyword(s):  
Water Absorption ◽  
Potassium Carbonate ◽  
Chemical Properties ◽  
Absorption Capacity ◽  
Gel Strength ◽  
Water Absorption Capacity ◽  
Fresh Sample ◽  
Plastic Container ◽  
Physico Chemical ◽  
Gelation Concentration

Effect of storage and concentration of potassium carbonate (K2CO3) on the viscosity and related physico – chemical properties of genger (Bombax costatum) powder was determined. Genger powder was stored for a period of four (4) months (May-August) at 30oc ± 5oc under varying concentrations of K2CO3: 0%, 5%, 10% and 15% in two containers (plastic, giving samples A – D and metal tins, giving samples A1 – D1). Thereafter, the moisture and crude fat contents, water absorption capacity, least gelation concentration, effect of K2CO3 concentration on gel strength and viscosity of the stored powders were determined, using standard methods of analysis, with fresh powder (analyzed before storage) as control. Moisture content decreased significantly (p < 0.05) from 8.37% to 3.04% and 2.00% in samples D and D1 respectively, while crude fat content increased significantly (p < 0.05) from 2.50% to 7.50% and 10.05% in the same samples. Water absorption capacity also increased significantly (p < 0.05) from 6.4g/g to 6.40g/g in the fresh sample to 7.30g/g and 8.30g/g in samples D and D1 respectively. Gelation capacity increased considerably, with 15% K2CO3 giving very strong gels at 1.50% concentration. The overall viscosity increased significantly (p < 0.05) with increase in concentration of (K2CO3) from 64.00FN to 110.00FN after storage. Generally, samples stored in metal tin gave better results than those in the plastic container.

scholarly journals The influence of the freezing rate on the physico-chemical properties of pork meat (M. Longissimus dorsi)

2019 ◽  
pp. 228-235
Author(s):  
Danica Savanovic ◽  
Radoslav Grujic ◽  
Jovo Savanovic
Keyword(s):  
Water Content ◽  
Ph Value ◽  
Chemical Properties ◽  
Storage Period ◽  
Freezing Rate ◽  
Longissimus Dorsi ◽  
Pork Meat ◽  
Physico Chemical ◽  
Meat Samples ◽  
Water Holding

The meat freezing, as a method of preservation, aims to maximize the storage period with preserving the quality and nutritional value of the product. However, freezing causes certain changes in the foodstuff. These changes are the result of ice formation and lead to a change in meat quality after thawing. The aim of this paper was to examine the effect of freezing rates on the physicochemical properties of pork meat (M. Longissimus dorsi). The meat samples were frozen at 10 different rates and after 24 hours of storage at -18?C, thawed at +4?C. Samples frozen at the lowest freezing rate (0.23 cm/h) had the lowest water content (72.02%), while for the samples frozen at the highest rate (1.43 cm/h), significantly higher (p<0.05) water content was recorded (73.85%). The protein content ranged from 23.34% (rate 0.50 cm/h) to 23.76% (rate 1.43 cm/h). The increase in freezing rates from 0.23 cm/h to 1.43 cm/h statistically significantly (p<0.05) affected the increase in the pH value (from 5.41 to 5.72). By measuring water holding capacity (WHC) the least amounts of released liquid (2.27 cm2 and 2.23 cm2) were recorded at higher freezing rate (1.00 cm/h and 1.43 cm/h, respectively). The highest thawing loss was determined in pork samples frozen at slower rate (0.23 cm/h) (3.61%).

Physico-chemical properties of C70-l-threonine bisadduct (C70(C4H9NO2)2) aqueous solutions

2019 ◽  
Vol 279 ◽  
pp. 687-699 ◽  
Author(s):  
Evgeny B. Serebryakov ◽  
Dmitry N. Zakusilo ◽  
Konstantin N. Semenov ◽  
Nikolay A. Charykov ◽  
Aleksandr V. Akentiev ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Chemical Properties ◽  
Physico Chemical

scholarly journals Variations in Soil Physico-Chemical Properties along Slope Position Gradient in Secondary Vegetation of the Hilly Region, Guilin, Southwest China

2020 ◽  
Vol 12 (4) ◽  
pp. 1303 ◽  
Author(s):  
Runhong Liu ◽  
Yuanfang Pan ◽  
Han Bao ◽  
Shichu Liang ◽  
Yong Jiang ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Southwest China ◽  
Chemical Properties ◽  
Slope Position ◽  
Secondary Vegetation ◽  
Physico Chemical ◽  
Hilly Region ◽  
Total Potassium

Understanding the variation of soil physico-chemical properties along slope position gradients is essential for vegetation restoration and reconstruction, but how slope positions impact the soil physico-chemical properties in the secondary vegetation of hilly regions is poorly understood. To address these uncertainties, we examined the changes in soil physico-chemical properties and their relationships along the slope position gradient in secondary vegetation of the hilly region in Guilin, southwest China. The results showed that except for the soil water content, soil total phosphorus and soil total potassium which reached the highest value at the footslope, other soil physico-chemical properties reached the highest content in the middle slope, and most of the soil physico-chemical properties showed the lowest content in the upper slope or footslope. Moreover, Pearson’s correlation analysis revealed that there were no significant correlations between most of the soil physico-chemical properties and that the correlations between soil physico-chemical properties were not consistent across different slope positions. Additionally, the principal component analysis showed that the first 4 principal components together explained 84.32% of the total variation and might be interpreted as the change of soil total nitrogen, soil organic matter, soil available nitrogen, soil available potassium, soil water content and soil total potassium. Overall, our results strongly demonstrated that slope positions showed significant effects on most of the soil physico-chemical properties and would provide an important reference for the formulation of restoration strategies in different slope positions to facilitate vegetation restoration and reconstruction and the sustainable development of the ecological environment in the hilly region.

scholarly journals Effect of Modifying Shellac with Citric Acid on Shellac-Bagasse Biocomposite

2019 ◽  
Vol 32 (1) ◽  
pp. 13-16
Author(s):  
Nanik Dwi Nurhayati ◽  
Karna Wijaya ◽  
Triyono ◽  
Eddy Heraldy
Keyword(s):  
Tensile Strength ◽  
Citric Acid ◽  
Intrinsic Viscosity ◽  
Testing Machine ◽  
Chemical Properties ◽  
Low Density ◽  
Universal Testing Machine ◽  
Universal Testing ◽  
Physico Chemical ◽  
Mechanical Tensile

This study was aimed at modifying local Shellac with citric acid in varied concentrations of 2, 4, 6, 8 and 10 % (w/w) to prepare Shellac-Bagasse (Sh-Bg) biocomposite and determining its physico-chemical properties. The biocomposite was made from the natural Shellac matrices and Bagasse fibers. Physico-chemical properties of non-modified Shellac and Shellac modified with citric acid including functional groups, intrinsic viscosity, density, and mechanical tensile strength were characterized using Fourier transform infrared spectrometer (FTIR), Oswald viscometer and Universal Testing Machine (UTM). The analysis results showed an optimum modification of shellac-citric acid at a concentration of 4% (w/w). FTIR analysis of the modified Shellac showed a broad absorption at 3448 cm–1 which indicated the presence of hydroxyl groups (-OH). The presence of C=O ester groups was indicated by the absorption appearing at 1712 cm–1. The absorption at 1251-1250 cm–1 indicated the presence of C-O groups, while the presence of -CH2 methylene groups was indicated by the absorption at 1465 cm–1. The modified Shellac with its optimal intrinsic viscosity of 169.97 mL/g indicated that there was a reaction between citric acid and Shellac to form an ester, so that the polymer chains formed were longer with a low density of 0,6662-0,8168 mg/L when compared to Shellac without modification. The low density indicated that the citric acid-modified Shellac could be processed to be biocomposite. The biocomposite was made with various compositions of Shellac and Bagasse with hot press at 80 °C and under a pressure of 6 Kgf/cm2. The optimum ratio of Shellac to Bagasse in Shellac-Bagasse (Sh-Bg) biocomposite was of 60:40 %. While, the analysis using Universal testing machine resulted a mechanical tensile strength of 0.6 MPa and an elongation at break of 0.45 %.

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