scholarly journals Identifikasi Karakteristik Pengecilan Ukuran dengan Metode Sonikasi dari Formula Insektisida yang Ditambahkan Surfaktan Berbasis Sawit

2021 ◽  
Vol 5 (1) ◽  
pp. 85
Author(s):  
Eka Nur'azmi Yunira ◽  
Ani Suryani ◽  
Dadang Dadang ◽  
Silvester Tursiloadi
Keyword(s):  
Contact Angle ◽  
High Speed ◽  
Chemical Properties ◽  
Plant Size ◽  
Size Reduction ◽  
Dispersion Surface ◽  
Physico Chemical ◽  
Pesticide Formulation ◽  
Reduction Methods ◽  
Emulsion Particle

Size reduction of pesticide formulation can improve its performance to pest and disease control in plant.  Size reduction methods were high speed agitation, ultrasonic emulsification, high pressure homogenization, microfluidic and membrane emulsification. Homogenizer and sonication methods were most widely used because its high effectivity in size reduction. The purpose of this research was to identify the effect of size reduction on physico chemical properties of the insecticide formulation by adding palm oil surfactant. The method of this research was to make an emulsifiable concentrate (EC) formulation using 15% active ingredient of emamectin benzoate, xylene, cationic surfactant of 1%, nonionic surfactants of 6% with DEA and APG surfactant ratio of 2:3. This formulation was mixed using Homogenizer at a speed of 4000 rpm and sonication with frequencies of 42 kHz at various times of 15, 30 and 45 minutes. The best result of this research was using sonication method for 45 minutes. The best physico-chemical properties were emulsion stability after 2 hours, cream formation after 24 hours emulsion, particle size of 0.70 μm with homogenous dispersion, surface tension of 25.54 dyne/cm, contact angle at 0 minutes of 25.05⁰ and contact angle after 15 minutes of 0⁰.

scholarly journals Controllable synthesis of pomelo peel-based aerogel and its application in adsorption of oil/organic pollutants

2019 ◽  
Vol 6 (2) ◽  
pp. 181823 ◽  
Author(s):  
Guangyu Shi ◽  
Yizhu Qian ◽  
Fengzhi Tan ◽  
Weijie Cai ◽  
Yuan Li ◽  
...  
Keyword(s):  
High Speed ◽  
Chemical Properties ◽  
Absorption Capacity ◽  
High Porosity ◽  
X Ray Diffraction ◽  
Water Separation ◽  
Physico Chemical ◽  
Wide Range ◽  
Oil Water Separation ◽  
Oil Water

Oil/water separation is a field of high significance as it might efficiently resolve the contamination of industrial oily wastewater and other oil/water pollution. In this paper, an environmentally-friendly hydrophobic aerogel with high porosity and low density was successfully synthesized with renewable pomelo peels (PPs) as precursors. Typically, a series of sponge aerogels (HPSA-0, HPSA-1 and HPSA-2) were facilely prepared via high-speed dispersion, freeze-drying and silanization with methyltrimethoxysilane. Indeed, the physical properties of aerogel such as density and pore diameter could be tailored by different additives (filter paper fibre and polyvinyl alcohol). Hence, their physico-chemical properties including internal morphology and chemical structure were characterized in detail by Fourier transform infrared, Brunauer–Emmett–Teller, X-ray diffraction, scanning electron microscope, Thermal gravimetric analyzer (TG) etc. Moreover, the adsorption capacity was further determined and the results revealed that the PP-based aerogels presented excellent adsorption performance for a wide range of oil products and/or organic solvents (crude oil 49.8 g g −1 , soya bean oil 62.3 g g −1 , chloroform 71.3 g g −1 etc.). The corresponding cyclic tests showed the absorption capacity decreased slightly from 94.66% to 93.82% after 10 consecutive cycles, indicating a high recyclability.

scholarly journals Influence of Dispersing Method on the Quality of Nano-Admixtures Homogenization in Cement Matrix

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4865
Author(s):  
Elżbieta Horszczaruk ◽  
Paweł Łukowski ◽  
Cyprian Seul
Keyword(s):  
High Speed ◽  
Mechanical Performance ◽  
Chemical Properties ◽  
Cement Composite ◽  
Cement Matrix ◽  
Cement Composites ◽  
Nano Sio2 ◽  
Mechanical Stirring ◽  
Physico Chemical ◽  
Nano Fe3o4

In recent years, a nano-modification of the cement composites allowed to develop a number of new materials. The use of even small amount of nano-admixture makes possible not only to improve the physico-mechanical properties of the cement materials, but also to obtain the composite with high usability, optimised for the given application. The basic problem of nano-modification of the cement composites remains the effectiveness of dispersing the nanomaterials inside the cement matrix. This paper deals with the effect of the type and size of the nanoparticles on the tendency to their agglomeration in the cement matrix. The main techniques and methods of dispersing the nanomaterials are presented. It has been demonstrated, on the basis of the results of testing of three nanomodifiers of 0D type (nano-SiO2, nano-Fe3O4 and nano-Pb3O4), how the structure and properties of the nanomaterial affect the behaviour of the particles when dissolving in the mixing water and applying a superplasticiser. The nanoparticles had similar size of about 100 nm but different physico-chemical properties. The methods of dispersing covered the use of high-speed mechanical stirring and ultrasonication. The influence of the method of nano-modifier dispersing on the mechanical performance of the cement composite has been presented on the basis of the results of testing the cement mortars modified with 3% admixture of nano-SiO2.

PHYSICO-CHEMICAL PROPERTIES OF RECYCLED REFINED, BLEACHED AND DEODORIZED (RBDPO) PALM OLEIN: WHICH CYCLE SHOULD THE OLEIN CONSIDERED SPOILAGE?

2017 ◽  
Vol 79 (4) ◽  
Author(s):  
Ili Afiqa Kadir ◽  
Lailatul Syema Jurid ◽  
Saiful Irwan Zubairi
Keyword(s):  
Contact Angle ◽  
Moisture Content ◽  
Iodine Value ◽  
Peroxide Value ◽  
Palm Olein ◽  
Chemical Properties ◽  
Colour Measurement ◽  
Rbd Palm Olein ◽  
Physico Chemical ◽  
Starch Composition

Palm olein is widely used for domestic and commercial frying but its usage beyond recommended cycle might lead to spoilage. Therefore, this study focuses on the comprehensive analysis of chemical and physical properties of recycled palm olein. It was prepared by frying potato strips up to 5 cycles with potato (g)-to-oil (ml) ratio of 3/20 prior to physico-chemical analysis. The temperature profile of RBD palm olein throughout frying also been investigated. It was done by taking the palm olein temperature during the frying of potato strips within 15 minutes for each cycle. There were physico-chemical analyses included colour measurement, viscosity, iodine value, peroxide value, moisture content, contact angle and density. However, according to the present result, peroxide value and contact angle was quite unsuitable or weak for the oil spoilage analysis for the first 5 cycles. Whereas moisture content, colour measurement, density, viscosity and iodine value were insignificant (p>0.05) for all cycles. Thus, those results could not be considered as definite indicators for spoilage assessment. This might be due to the starch composition within the potato strips that shows no changes despite 5 frying cycles. For that reason, further analysis (greater than 5 cycles) is needed to confirm at which oil cycle of that oil should become spoiled.

Biosynthesis of poly(3-hydroxybutyrateco-3-hydroxy-4-methylvalerate) by Strain Azotobacter chroococcum 7B

Acta Naturae ◽  
2016 ◽  
Vol 8 (3) ◽  
pp. 77-87 ◽  
Author(s):  
A. P. Bonartsev ◽  
G. A. Bonartseva ◽  
V. L. Myshkina ◽  
V. V. Voinova ◽  
T. K. Mahina ◽  
...  
Keyword(s):  
Contact Angle ◽  
Effective Strain ◽  
Chemical Properties ◽  
Azotobacter Chroococcum ◽  
Resonance Spectroscopy ◽  
Molar Content ◽  
In Vitro Biocompatibility ◽  
Physico Chemical ◽  
Copolymer Poly

Production of novel polyhydroxyalkanoates (PHAs), biodegradable polymers for biomedical applications, and biomaterials based on them is a promising trend in modern bioengineering. We studied the ability of an effective strain-producer Azotobacter chroococcum 7B to synthesize not only poly(3-hydroxybutyrate) homopolymer (PHB) and its main copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), but also a novel copolymer, poly(3-hydroxybutyrate-co-3-hydroxy-4-methylvalerate) (PHB4MV). For the biosynthesis of PHB copolymers, we used carboxylic acids as additional carbon sources and monomer precursors in the chain of synthesized copolymers. The main parameters of these polymers biosynthesis were determined: strain-producer biomass yield, polymer yield, molecular weight and monomer composition of the synthesized polymers, as well as the morphology of A. chroococcum 7B bacterial cells. The physico-chemical properties of the polymers were studied using nuclear magnetic resonance spectroscopy (NMR), differential scanning calorimetry (DSC), contact angle test, and other methods. In vitro biocompatibility of the obtained polymers was investigated using stromal cells isolated from the bone marrow of rats with the XTT cell viability test. The synthesis of the novel copolymer PHB4MV and its chemical composition were demonstrated by NMR spectroscopy: the addition of 4-methylvaleric acid to the culture medium resulted in incorporation of 3-hydroxy-4-methylvalerate (3H4MV) monomers into the PHB polymer chain (0.6 mol%). Despite the low molar content of 3H4MV in the obtained copolymer, its physico-chemical properties were significantly different from those of the PHB homopolymer: it has lower crystallinity and a higher contact angle, i.e. the physico-chemical properties of the PHB4MV copolymer containing only 0.6 mol% of 3H4MV corresponded to a PHBV copolymer with a molar content ranging from 2.5% to 7.8%. In vitro biocompatibility of the obtained PHB4MV copolymer, measured in the XTT test, was not statistically different from the cell growth of PHB and PHBV polymers, which make its use possible in biomedical research and development.

Effect of antioxidants on physico-chemical properties of EURO-III HSD (high speed diesel) and Jatropha biodiesel blends

Energy ◽  
2013 ◽  
Vol 60 ◽  
pp. 222-229 ◽  
Author(s):  
Bhawna Yadav Lamba ◽  
Girdhar Joshi ◽  
Avanish K. Tiwari ◽  
Devendra Singh Rawat ◽  
Sudesh Mallick
Keyword(s):  
High Speed ◽  
Chemical Properties ◽  
Biodiesel Blends ◽  
Physico Chemical ◽  
High Speed Diesel

scholarly journals An actin-depolymerizing protein (depactin) from starfish oocytes: properties and interaction with actin.

1983 ◽  
Vol 97 (5) ◽  
pp. 1612-1621 ◽  
Author(s):  
I Mabuchi
Keyword(s):  
High Speed ◽  
Actin Polymerization ◽  
Critical Concentration ◽  
Chemical Properties ◽  
Water Soluble ◽  
Molar Ratio ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Denatured Protein ◽  
Physico Chemical

Physico-chemical properties and interaction with actin of an actin-depolymerizing protein from mature starfish oocytes were studied. This protein, which is called depactin, exists in a monomeric form under physiological conditions. Its molecular weight is approximately 20,000 for the native protein and approximately 17,000 for denatured protein. The Glu + Asp/Lys + Arg molar ratio of this protein is 1.55. The apparent pl of the denatured depactin is approximately 6. The extent of actin polymerization is reduced by the presence of depactin; however, the rate of polymerization seems to be accelerated as measured spectrophotometrically at 238nm. This effect is interpreted to indicate that depactin cut the newly formed filaments into small fragments, thereby increasing the number of the filament ends to which monomers are added. The apparent critical concentration of actin for polymerization, as determined by viscometry or flow birefringence measurement, is increased by the presence of depactin in a concentration-dependent manner. Raising the pH of the solution does not reverse the action of depactin. The molar ratio of actin and depactin, which interact with each other, is estimated to be 1:1 by means of a cross-linking experiment using a water-soluble carbodiimide. Depactin binds to a DNase I-Sepharose column via actin and is selectively eluted with 0.6 M KCl or 0.6 M Kl. The association constant between actin and depactin is estimated, using the column, to be 2-3 X 10(6) M-1. The content of depactin in the high-speed supernatant of the oocyte extract is determined to be 1%; this can act upon approximately 63% of the actin in the supernatant.

Decoration of specific sites on freeze-fractured membranes

1978 ◽  
Vol 36 (2) ◽  
pp. 140-141
Author(s):  
H. Gross ◽  
H. Moor
Keyword(s):  
Pure Water ◽  
Freeze Fracture ◽  
Chemical Properties ◽  
Surface Forces ◽  
Sulfate Pentahydrate ◽  
Copper Sulfate Pentahydrate ◽  
Physico Chemical ◽  
Water Of Hydration ◽  
Small Container ◽  
Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

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