KINETICS OF EVAPORATION OF DISTILLED WATER BY DRYING FROM WATER–PROTEIN MIXTURE IN ISOTHERMAL CONDITIONS

2018 ◽  
Author(s):  
А.С. ДАНИЛЬЧЕНКО ◽  
Т.Г. КОРОТКОВА ◽  
С.Ю. КСАНДОПУЛО
Keyword(s):  
Petri Dish ◽  
Moisture Loss ◽  
Distilled Water ◽  
Protein Film ◽  
Protein Mixture ◽  
Isothermal Conditions ◽  
Petri Dishes ◽  
Conformational Rearrangements ◽  
Rate Of Evaporation ◽  
Kinetics Of

Приведены результаты исследований кинетики испарения воды при сушке смеси вода–белок при 60°С в изотермических условиях. Смесь готовили из дистиллированной воды, предварительно доведенной до кипения при атмосферном давлении, которую заливали в две чашки Петри по 20 мл в каждую, и яичного белка, добавленного в количестве 0,2 и 0,6 мл соответственно. Чашки Петри помещали в сушильный шкаф Memmert, оснащенный принудительной конвекцией и устройством контроля температуры. Навеску с чашкой Петри взвешивали через каждые 5 мин на аналитических весах Discovery. Установлено, что увеличение количества белка снижает скорость испарения воды в периоде постоянной скорости сушки, скорость испарения зависит от природы растворенного вещества. По окончании процесса испарения на дне чашки Петри обнаружена полупрозрачная высохшая пленка белка, что свидетельствует о конформационных перестройках белка в процессе убыли влаги и частичном растворении белка в воде в процессе испарения. The results of studies of the kinetics of evaporation of water during drying of the water–protein mixture at 60°C in isothermal conditions are given. The mixture was prepared from distilled water, pre-boiled at atmospheric pressure, which was poured into two Petri dishes of 20 ml each, and egg white added in an amount of 0,2 and 0,6 ml, respectively. Petri dishes were placed in a Memmert drying Cabinet equipped with forced convection and a temperature control equipment. The overhang with a Petri dish was weighed every 5 min on the analytical scales of Discovery. It was found that an increase in the amount of egg protein reduces the rate of evaporation of water in a period of constant drying rate and the rate of evaporation depends on the nature of the dissolved substance. At the end of the evaporation process, a translucent dried protein film is found at the bottom of the Petri dish, which indicates the conformational rearrangements of the protein in the process of moisture loss and partial dissolution of the protein in the water during evaporation.

scholarly journals Germination of seeds and growth of seedlings of selected grass species under the influence of blastokolins from germinating grass seeds

2012 ◽  
Vol 59 (2) ◽  
pp. 253-262
Author(s):  
Halina Lipińska
Keyword(s):  
Seed Germination ◽  
Poa Pratensis ◽  
Petri Dish ◽  
Phleum Pratense ◽  
Grass Species ◽  
Festuca Pratensis ◽  
Distilled Water ◽  
Petri Dishes ◽  
Randomization Method ◽  
Growth Of Seedlings

Experiments were carried out under laboratory conditions in Department of Grass Science and Greenland Shaping in 2002-2004. Studies included six experiment series on Petri dishes set by means of complete randomization method in four replications. Following species were tested: <i>Festulolium</i>, <i>Festuca pratensis</i>, <i>Lolium perenne</i>, <i>Phleum pratense</i> and <i>Poa pratensis</i> making one or two-species combinations. Fifteen seeds of two species were arranged alternately in 1- centimeter distance on a Petri dish. Objects where seeds germinated with no neighborhood of other species (30 seeds on a dish), were control. The filter's humidity on Petri dishes was maintained by wetting it with distilled water. Achieved results revealed significant influence of blastokolins of tested grass species on seed germination and initial seedling growth. Secretion of germinating <i>Festulolium</i> seeds showed the highest activity. Reaction of tested grass species to allelochemicals varied. In reference to control objects, <i>Phleum pratense</i> among tested species was distinguished with the highest susceptibility to allelochemicals released during seed germination.

scholarly journals Toxicity of Three Formulations of Bacillus Thuringiensis Against Diamondback Moth, 1996

1998 ◽  
Vol 23 (1) ◽  
pp. 369-369
Author(s):  
P. W. Ivey ◽  
S. J. Johnson ◽  
Richard Story
Keyword(s):  
Bacillus Thuringiensis ◽  
Untreated Control ◽  
Room Temperature ◽  
Diamondback Moth ◽  
Petri Dish ◽  
Test Solution ◽  
Leaf Disk ◽  
Distilled Water ◽  
Dilution Series ◽  
Petri Dishes

Abstract A leaf-dip assay was used to test three commercial formulations of B. thuringiensis Berliner: Agree 50 WP, Dipel ES, and XenTari AS, against diamondback moth. Concentrations ([AI]/liter) were based on dilution series using the recommended “field” rates of the three formulations of B. thuringiensis. Dipel and Xen-Tari were tested at concentrations of 2.5, 0.25, 0.025, 0.0025, and 0.00025 [ml (AI)/liter]; Agree was tested at concentrations of 3.0, 0.3, 0.03, 0.003, and 0.0003 [g(AI)/liter]. Disks (20 mm diam) were cut from leaves of the above cabbage cultivar. Each disk was dipped into each test solution and hung vertically to dry at room temperature for about 1 h and then placed in petri dishes (100 X 15 mm) on top of a moistened filter peper (90 mm diameter). Five third instars were placed on each leaf disk in each petri dish and allowed to feed for 96 h, after which mortality was recorded. A larva was considered dead if it did not move when prodded with forceps. Tests with each concentration and the untreated control (distilled water) were replicated five times.

scholarly journals A slit sampler for collecting and counting air-borne bacteria

1941 ◽  
Vol 41 (2) ◽  
pp. 197-224 ◽  
Author(s):  
R. B. Bourdillon ◽  
O. M. Lidwell ◽  
John C. Thomas
Keyword(s):  
Collection Efficiency ◽  
Petri Dish ◽  
Narrow Slit ◽  
Sampling Efficiency ◽  
Distilled Water ◽  
Selective Effect ◽  
Great Caution ◽  
Petri Dishes ◽  
Made In

1. A slit sampler for air-borne bacteria is described, in which air is sucked through a narrow slit on to the surface of agar in an ordinary Petri dish.2. This method has proved very rapid and simple in use, and has appeared more efficient than other methods against which it has been tested.3. The collection efficiency for an aerosol consisting of Staph. albus, sprayed from distilled water as single cocci, is about 96%. The method thus collects the finest bacteria-carrying, particles almost as efficiently as coarser ones.4. In contrast to this, the exposure of plain open Petri dishes appears to collect the larger particles in the air of crowded rooms at least 200 times as efficiently as it does single washed bacteria. This highly selective effect renders it advisable to use great caution in evaluating tests made in plain open dishes.5. The methods of determining sampling efficiency, and their errors are discussed in detail.

scholarly journals Pyrolysis and Oxidation of PAN in Dry Air. Thermoanalytical Methods

1970 ◽  
Vol 17 (1) ◽  
pp. 38-42
Author(s):  
Anna BIEDUNKIEWICZ ◽  
Pawel FIGIEL ◽  
Marta SABARA
Keyword(s):  
Temperature Increase ◽  
Heating Rates ◽  
Linear Change ◽  
Dry Air ◽  
Isothermal Conditions ◽  
Gaseous Products ◽  
Heterogeneous Processes ◽  
Temperature Ranges ◽  
Higher Temperature ◽  
Kinetics Of

The results of investigations on pyrolysis and oxidation of pure polyacrylonitrile (PAN) and its mixture with N,N-dimethylformamide (DMF) under non-isothermal conditions at linear change of samples temperature in time are presented. In each case process proceeded in different way. During pyrolysis of pure PAN the material containing mainly the product after PAN cyclization was obtained, while pyrolysis of PAN+DMF mixture gave the product after cyclization and stabilization. Under conditions of measurements, in both temperature ranges, series of gaseous products were formed.For the PAN-DMF system measurements at different samples heating rates were performed. The obtained results were in accordance with the kinetics of heterogeneous processes theory. The process rates in stages increased along with the temperature increase, and TG, DTG and HF function curves were shifted into higher temperature range. This means that the process of pyrolysis and oxidation of PAN in dry air can be carried out in a controlled way.http://dx.doi.org/10.5755/j01.ms.17.1.246

scholarly journals Response of Mexican Corn Rootworm to Insecticides, 1991

1995 ◽  
Vol 20 (1) ◽  
pp. 329-329
Author(s):  
E. Guerrero-Rodriguez ◽  
S. Davalos-Luna ◽  
J. Corrales-Reynaga
Keyword(s):  
Petri Dish ◽  
Mortality Data ◽  
Corn Rootworm ◽  
Field Corn ◽  
Paper Towel ◽  
Percent Mortality ◽  
Petri Dishes ◽  
Mexican Corn Rootworm ◽  
Corn Plants ◽  
Commercial Field

Abstract Populations of MCR of commercial field corn from Arenal, Jalisco were exposed to nine insecticides of organophosphorous (OP), cabamate, organo chlorinated and pyrethroid groups. Larvae were collected from the roots of corn plants daily, and confined in polyethylene black bags of two kg capacity with humidity and germinated corn as food for larvae. Insects were taken to the laboratory of Sanidad Vegetal in Guadalajara, Jalisco. Dilutions of the insecticides tested were prepared using acetone from 500 to 5000 ppm (6 to 9 dosage/product). For this study 20 larvae of last instar were selected and 1 u, liter of the solution was placed topically on the thorax, after this, each larva was placed in a petri dish with a moistened paper towel and the petri dishes confined in a cardboard box to eliminate light. Mortality counts were carried out at 24 hours. Percent mortality was corrected by Abbott’s formula. The mortality data were analyzed by probit to obtain LC50 and LC,5 values for each insecticide.

scholarly journals Filamentous fungi isolated from sand and water of "Bairro Novo" and "Casa Caiada" beaches, Olinda, Pernambuco, Brazil

2008 ◽  
Vol 68 (3) ◽  
pp. 577-582 ◽  
Author(s):  
DNF. Gomes ◽  
MAQ. Cavalcanti ◽  
MJS. Fernandes ◽  
DMM. Lima ◽  
JZO. Passavante
Keyword(s):  
Water Samples ◽  
Water Surface ◽  
High Tide ◽  
Sand Sample ◽  
Distilled Water ◽  
Sabouraud Agar ◽  
Sand Surface ◽  
Heterotrophic Microorganisms ◽  
Petri Dishes ◽  
Dry And Rainy Seasons

Fungi comprehend a heterogeneous group of heterotrophic microorganisms that act as saprobes or parasites or, less frequently, as symbionts living in association with other organisms. They are cosmopolitan and important components of ecosystems. Considering the small number of Brazilian papers on the filamentous mycota in marine environments, and the need to improve knowledge of the diversity of these microfungi in "Casa Caiada" and "Bairro Novo" beaches, Olinda, PE, the aim of this work was to isolate and identify the fungi from sand and water samples of these ecosystems. Thirty two samplings of sand (surface and 20 cm deep) and water (surface and 1 m deep) were carried out during the dry and rainy seasons, in low and high tide. From each sand sample, a suspension was made with 50 g of sand diluted in 90 mL of sterilized distilled water. From each sand suspension and water sample, 0.5 mL was spread, in triplicate, onto Petri dishes containing Sabouraud Agar added of chloramphenicol. The plates were incubated at 28 °C (±2 °C). Fifty seven species were isolated, identified, and classified in 20 genera. Aspergillus and Penicillium were the most frequent genera in both sand and water, with a total of 11 and 19 species, respectively.

Kinetics of tungsten carbidization under non-isothermal conditions

2008 ◽  
Vol 43 (4) ◽  
pp. 897-906 ◽  
Author(s):  
S.L. Kharatyan ◽  
H.A. Chatilyan ◽  
L.H. Arakelyan
Keyword(s):  
Isothermal Conditions ◽  
Kinetics Of

Kinetics of synthesizing process for obtaining iron nanopowder by chemical-metallurgical method under isothermal conditions

2021 ◽  
pp. 72-77
Author(s):  
Tien Hiep Nguyen ◽  
◽  
Van Minh Nguyen ◽  
Keyword(s):  
Hydrogen Reduction ◽  
Average Particle Size ◽  
Chemical Deposition ◽  
Reduction Process ◽  
Nitrogen Adsorption ◽  
Specific Rate ◽  
Average Particle ◽  
Isothermal Conditions ◽  
Electron Microscopes ◽  
Kinetics Of

In this work the kinetics of synthesizing process of metallic iron nanopowder by hydrogen reduction from α-FeOOH hydroxide under isothermal conditions were studied. α-FeOOH nanopowder was prepared in advance by chemical deposition from aqueous solutions of iron nitrate Fe(NO3)3 (10 wt. %) and alkali NaOH (10 wt. %) at room temperature, pH = 11, under the condition of continuous stirring. The hydrogen reduction process of α-FeOOH nanopowder under isothermal conditions was carried out in a tube furnace in the temperature range from 390 to 470 °C. The study of the crystal structure and composition of the powders was performed by X-ray phase analysis. The specific surface area S of the samples was measured using BET method by low-temperature nitrogen adsorption. The average particle size D of powders was determined via the measured S value. The size characteristics and morphology of the particles were investigated by transmission and scanning electron microscopes. The calculation of the kinetic parameters of the hydrogen reduction process of α-FeOOH under isothermal conditions was carried out by the Gray-Weddington model and Arrhenius equation. It is shown that the rate constant of reduction at 470 °C is approximately 2.2 times higher than in the case at 390 °C. The effective activation energy of synthesizing process of iron nanopowder by hydrogen reduction from α-FeOOH was ~38 kJ/mol, which indicates a mixed reaction mode. In this case, the kinetics overall process is limited by both the kinetics of the chemical reaction and the kinetics of diffusion, respectively, an expedient way to accelerate the process by increasing the temperature or eliminate the diffusion layer of the reduction product by intensive mixing. It is show that Fe nanoparticles obtained by hydrogen reduction of its hydroxide at 410 °C, corresponding to the maximum specific rate of the reduction process, are mainly irregular in shape, evenly distributed, the size of which ranges from several dozens to 100 nm with an average value of 75 nm.

Study on the kinetics of process for obtaining cobalt nanopowder by hydrogen reduction under isothermal conditions

2021 ◽  
Vol 1 (1) ◽  
pp. 49-56
Author(s):  
Hieр Nguyen Tien
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Hydrogen Reduction ◽  
Average Particle Size ◽  
Chemical Deposition ◽  
Average Particle ◽  
Isothermal Conditions ◽  
Electron Microscopes ◽  
Kinetics Of

The kinetics of metallic cobalt nanopowder synthesizing by hydrogen reduction from Co(OH)2 nanopowder under isothermal conditions were studied. Co(OH)2 nanopowder was prepared in advance by chemical deposition from aqueous solutions of Co(NO3)2 cobalt nitrate (10 wt.%) and NaOH alkali (10 wt.%) at room temperature, pH = 9 under continuous stirring. The hydrogen reduction of Co(OH)2 nanopowder under isothermal conditions was carried out in a tube furnace in the temperature range from 270 to 310 °C. The crystal structure and composition of powders was studied by X-ray phase analysis. The specific surface area of samples was measured using the BET method by low-temperature nitrogen adsorption. The average particle size of powders was determined by the measured specific surface area. Particles size characteristics and morphology were investigated by transmission and scanning electron microscopes. Kinetic parameters of Co(OH)2 hydrogen reduction under isothermal conditions were calculated using the Gray–Weddington model and Arrhenius equation. It was found that the rate constant of reduction at t = 310 °C is approximately 1.93 times higher than at 270 °C, so the process accelerates by 1.58 times for 40 min of reduction. The activation energy of cobalt nanopowder synthesizing from Co(OH)2 by hydrogen reduction is ~40 kJ/mol, which indicates a mixed reaction mode. It was shown that cobalt nanoparticles obtained by the hydrogen reduction of its hydroxide at 280 °C are aggregates of equiaxed particles up to 100 nm in size where individual particles are connected to several neighboring particles by contact isthmuses.

scholarly journals Laboratory Bioassay of Beauveria Bassiana, Spinosad, Garlic, and Neem-Derived Products for Control of Grasshoppers

1998 ◽  
Vol 23 (1) ◽  
pp. 372-372
Author(s):  
Nihat Demirel ◽  
Whitney Cranshaw
Keyword(s):  
Beauveria Bassiana ◽  
Petri Dish ◽  
Neem Oil ◽  
Laboratory Bioassay ◽  
Neem Extract ◽  
Late Instar ◽  
Petri Dishes

Abstract Trials were conducted with adult, field collected migratory grasshoppers to determine susceptibility to ingestion expo sure to Beauveria bassiana Strain GHA (BotaniGard WP), spinosad (Conserve SC) a garlic-derived insecticide/repellent (Garlic Barrier), neem oil (Tril ogy) and a neem extract (BioNeem). Field collected late instar grasshoppers were confined, 8 per petri dish (100 mm X 15 mm), with 6 petri dishes usetl per treatment. Treatments involved dipping alfalfa leaves into the insecticide solutions and allowing them to air dry before feeding these to the grasshop pers. After the originally treated foliage were consumed, untreated foliage was used to maintain grasshoppers in all treatments. Mortality was assessed a 24, 48, 96, and 192 h after exposure.

Sign in / Sign up

Export Citation Format

Share Document