scholarly journals ИССЛЕДОВАНИЕ РАБОТЫ ГЕНЕРАТОРА  ГОРЯЧЕГО ТУМАНА ПРИ ОБРАБОТКЕ СТЕБЛЕСТОЯ

2019 ◽  
Author(s):  
M.Y. KOSTENKO ◽  
R.V. BEZNOSYUK ◽  
I.N. GORYACHKINA ◽  
G.K. REMBALOVICH ◽  
G.A. BORISOV ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Crystal Size ◽  
Universal Method ◽  
Protective Film ◽  
Large Drop ◽  
Concentration Of Solutions ◽  
Ultrafine Aerosols ◽  
Working Solution ◽  
Higher Temperature ◽  
Average Size

Опрыскивание представляет универсальный способ применения защитно-стимулирующих веществ. Эффективность опрыскивания зависит от концентрации растворов и размера капель и их осаждения на поверхности листьев. Множество мелких капель имеют такой же объем препарата, что и одна крупная капля, но контактируют с большей площадью растения, что обеспечивает наиболее быстрое и одновременное проникновение препарата. Обработка растений предъявляет определенные технические и технологические требования к техническим средствам, которые должны выполнять сразу несколько технологических операций одновременно - образование защитной пленки микроэлементов и биопрепаратов на их поверхности, равномерная доставка капель к растениям. Наиболее предъявляемым требованиям отвечают генераторы горячего тумана, которые позволяют получать ультрадисперсные аэрозоли. Исследование движения аэрозолей затруднено из-за взаимопроникновения двух сплошных сред горячего тумана и воздуха, а также обтекания препятствий в виде растений. Кроме того горячий туман имеет более высокую температуру в сравнение с окружающим воздухом и растениями, и поэтому применение классических положений аэродинамики затруднено. Распространение горячего тумана в стеблях растений возможно исследовать экспериментально. Так как капли горячего тумана имеют более высокую температуру, чем обрабатываемые объекты, они быстро испаряются. Поэтому в качестве рабочего раствора использовали 20 водный раствор соли NaCl. Распределение кристаллов по размерам исследовали с помощью статического анализа. Средний размер капель горячего тумана составляет 9,5 мкм. Расход рабочего раствора на данном режиме генератора составляет 3,0 л/ч, расход топлива 2,1 л/ч. Следует отметить, что наибольший размер капель наблюдается на краях поддона, что обусловлено инерционным распределением горячего тумана. Исследования распределения капель горячего тумана в стеблестое растений показали, что наибольшее покрытие каплями обрабатываемой поверхности происходит в непосредственной близости от генератора горячего тумана, при этом среднее значение количества кристаллов на 1 см2 составляет 41132 штук.Spraying is a universal method of application of protective and stimulating substances. The effectiveness of spraying depends on the concentration of solutions and the size of the drops and their deposition on the surface of the leaves. Many small drops have the same volume of the drug as one large drop, but contact a larger area of the plant, which provides the fastest and simultaneous penetration of the drug. Treatment of plants imposes certain technical and technological requirements to the technical means, which must perform several technological operations simultaneously-the formation of a protective film of trace elements and biological products on their surface, uniform delivery of drops to plants. The most demanding requirements are met by hot mist generators, which allow to obtain ultrafine aerosols. The study of the movement of aerosols is difficult because of the interpenetration of two continuous media-hot fog and air, as well as the flow of obstacles in the form of plants. In addition, the hot fog has a higher temperature in comparison with the surrounding air and plants, and therefore the application of the classical provisions of aerodynamics is difficult. The distribution of hot mist in the stems of plants can be investigated experimentally. Since hot mist droplets have a higher temperature than the objects being treated, they evaporate quickly. Therefore, a 20 aqueous solution of NaCl salt was used as a working solution. The crystal size distribution was studied by static analysis. The average size of hot mist droplets is 9.5 microns. The flow rate of the working solution in this mode of the generator is 3.0 l / h, fuel consumption-2.1 l / h. It should be noted that the largest size of drops is observed at the edges of the pallet, due to the inertial distribution of hot fog. Studies of the distribution of hot mist droplets in the stem of plants have shown that the greatest coating of the treated surface drops occurs in the immediate vicinity of the hot mist generator, with the average number of crystals per 1 cm2 is 41132 pieces.

Preparation of BSA Nanoparticles by Desolvation Technique Using Acetone as Desolvating Agent

2012 ◽  
Vol 5 (1) ◽  
pp. 1643-1647
Author(s):  
Krishna Sailaja A ◽  
Amareshwar P
Keyword(s):  
Aqueous Solution ◽  
Standard Deviation ◽  
Process Parameters ◽  
Self Assembly ◽  
Size Control ◽  
Polymeric Materials ◽  
Preparation Condition ◽  
Assembly Process ◽  
Average Size

In order to see the functionality and toxicity of nanoparticles in various food and drug applications, it is important to establish procedures to prepare nanoparticles of a controlled size. Desolvation is a thermodynamically driven self-assembly process for polymeric materials. In this study, we prepared BSA nanoparticles using the desolvation technique using acetone as desolvating agent. Acetone was added intermittently into 1% BSA solution at different pH under stirring at 700 rpm. Amount of acetone added, intermittent timeline of acetone addition, and pH of solution were considered as process parameters to be optimized. The effect of the process parameters on size of the nanoparticles was studied. The results indicated that the size control of BSA nanoparticles was achieved by adding acetone intermittently. The standard deviation of average size of BSA nanoparticles at each preparation condition was minimized by adding acetone intermittently. The intermittent addition in polymeric aqueous solution can be useful for size control for food or drug applications.  

Batch Precipitation of Lead Iodide

1994 ◽  
Vol 59 (6) ◽  
pp. 1301-1304
Author(s):  
Jaroslav Nývlt ◽  
Stanislav Žáček
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Crystal Size ◽  
Lead Nitrate ◽  
Lead Iodide ◽  
Constant Rate ◽  
Mean Size ◽  
The Mean

Lead iodide was precipitated by a procedure in which an aqueous solution of potassium iodide at a concentration of 0.03, 0.10 or 0.20 mol l-1 was stirred while an aqueous solution of lead nitrate at one-half concentration was added at a constant rate. The mean size of the PbI2 crystals was determined by evaluating the particle size distribution, which was measured sedimentometrically. The dependence of the mean crystal size on the duration of the experiment exhibited a minimum for any of the concentrations applied. The reason for this is discussed.

scholarly journals Synergistic and Antagonistic Effects of Sodium Molybdate-Zn2+System

2012 ◽  
Vol 9 (4) ◽  
pp. 1746-1752 ◽  
Author(s):  
J. Wilson Sahayaraj ◽  
A. John Amalraj ◽  
Susai Rajendran ◽  
N. Vijaya
Keyword(s):  
Aqueous Solution ◽  
Weight Loss ◽  
Inhibition Efficiency ◽  
Sodium Molybdate ◽  
Antagonistic Effect ◽  
Protective Film ◽  
Antagonistic Effects ◽  
Polarization Study ◽  
Weight Loss Method ◽  
Loss Method

The inhibition efficiency (IE) of sodium molybdate (SM) in controlling corrosion of carbon steel in an aqueous solution containing 120 ppm of Cl-, in the absence and presence of Zn2+has been evaluated by weight-loss method. A synergistic effect exists between SM and Zn2+when the concentration of Zn2+is 25 ppm and above. Inhibition efficiencies obtained are greater than 85%. Antagonistic effect exists between SM and Zn2+when the concentration of Zn2+is 10 ppm and below. The SM-Zn2+system shows excellent IE up to third day. Above third day IE decreases. Acceleration of corrosion takes place. Excellent IE is shown at pH 5,7 and 12. At pH 9, IE decreases since Zn2+is precipitated as Zn(OH)2in the bulk of the solution. Polarization study reveals that SM-Zn2+system functions as a mixed inhibitor. FTIR spectra reveal that the protective film consists of Fe2+-SM complex and Zn(OH)2.

A Convenient Method for Preparing Well-Dispersed Er2Zr2O7 Nanocrystals

2010 ◽  
Vol 123-125 ◽  
pp. 611-614 ◽  
Author(s):  
Yu Ping Tong ◽  
Rui Zhu Zhang ◽  
Shun Bo Zhao ◽  
Chang Yong Li
Keyword(s):  
Particle Size ◽  
Combustion Synthesis ◽  
Crystal Size ◽  
Lattice Distortion ◽  
Combustion Method ◽  
Treatment Temperature ◽  
Synthesis Process ◽  
Thermal Treatment Temperature ◽  
Average Size ◽  
Xrd And Tem

Well-dispersed fluorite Er2Zr2O7 nanocrystals have been successfully prepared by a convenient salt-assistant combustion method. The effects of calcinations temperature and salt category on the characteristics of the products were investigated by XRD and TEM. The thermal treatment temperature has an important effect on crystal size and lattice distortion of the nanocrystals. The experiment showed that the introduction of salt in the combustion synthesis process resulted in the formation of well-dispersed Er2Zr2O7 nanocrystals. The average size was 30 nm and was in agreement with the XRD result, which indicated that the nanocrystals were uniform in particle size distribution. Moreover, the possible formation process in the salt-assisted combustion synthesis was also analyzed.

Comparison of Coal Ash and Activated Carbon for Removal of Humic Acid from Aqueous Solution

2013 ◽  
Vol 864-867 ◽  
pp. 1509-1512
Author(s):  
Xue Mei Zhang ◽  
Yan Zhang ◽  
Di Fan
Keyword(s):  
Aqueous Solution ◽  
Humic Acid ◽  
Activated Carbons ◽  
Removal Rate ◽  
Coal Ash ◽  
Cost Effective ◽  
Solution Ph ◽  
Adsorption Behaviors ◽  
Calcium Loading ◽  
Working Solution

This paper presents the adsorption behaviors of humic acid (HA) on coal ashes and powdered activated carbons (PACs). A bituminous coal, with or without calcium-loading, was used as a feedstock for coal ash preparation. The working solution of HA with a concentration of 20 mg/L was used in all adsorption tests. The results showed that calcium-enriched coal ash (CECA) gave rise to the removal rate of HA as high as 84.05%, much higher than those of raw coal ash (RCA) and PACs. The impacts of solution pH and adsorbent dosage on HA adsorption capacity were also investigated. It was found that lower pH facilitated to the removal of HA from aqueous solution by means of CECA, and the optimal CECA dosage was about 1.0g/L at pH 7.00. The data obtained in this study suggested that calcium-enriched coal ash could be useful and cost-effective in the treatment of wastewaters containing HA-like organic macro-molecules.

scholarly journals Effect of Al Content in the Mg-Based Alloys on the Composition and Corrosion Resistance of Composite Hydroxide Films Formed by Steam Coating

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1188 ◽  
Author(s):  
Takahiro Ishizaki ◽  
Tomohiro Miyashita ◽  
Momo Inamura ◽  
Yuma Nagashima ◽  
Ai Serizawa
Keyword(s):  
Aqueous Solution ◽  
Corrosion Resistance ◽  
Treatment Time ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Potential Range ◽  
Protective Film ◽  
Al Content ◽  
Passive Behavior ◽  
Superior Corrosion Resistance

Mg alloys are expected to be used in fields of the transportation industry because of their lightweight property, however, they show low corrosion resistance. To improve the corrosion resistance, preparation of the protective film on Mg alloys is essential. In this study, composite hydroxide films were prepared on three types of Mg alloys with different aluminum contents—that is, AZ31, AZ61, and AZ91D—by steam coating to investigate the relationship between the Mg-Al layered double hydroxide (LDH) content in the film and the Al content in the Mg alloys. Scanning electron microscopy (SEM) observation demonstrated that films were formed densely on all Mg alloy surfaces. X-ray diffraction (XRD) analyses revealed that all films prepared on AZ61 and AZ91D were composed of Mg(OH)2, AlOOH, and Mg-Al LDH, while the film containing Mg(OH)2 and Mg-Al LDH were formed only on AZ31. The Mg-Al LDH content in the film prepared on AZ61 was relatively higher than those prepared on AZ31 and AZ91D. The content of AlOOH in the film increased with an increase in the Al content in the Mg alloys. The film thickness changed depending on the treatment time and type of Mg alloy. Polarization curve measurements in 5 mass% NaCl solution demonstrated that the film prepared on the AZ61 showed complete passive behavior within the potential range of −1.0 to −0.64 V. In addition, immersion tests in 5 mass% NaCl aqueous solution for 480 h demonstrated that the film on the AZ61 had superior durability against 5 mass% NaCl aqueous solution. These results indicated that the film on the AZ61 had the most superior corrosion resistance among all samples. The results obtained in this study suggest that the LDH content in the film could be related to the corrosion resistance of the film.

Synthesis and Dispersion of Ni-Doped Cu2ZnSnS4

2020 ◽  
Vol 860 ◽  
pp. 42-50
Author(s):  
Camellia Panatarani ◽  
Hera Redianti ◽  
Ferry Faizal ◽  
Eka Cahya Prima ◽  
Brian Yuliarto ◽  
...  
Keyword(s):  
Thin Film ◽  
Phase Transformation ◽  
Zeta Potential ◽  
Elemental Analysis ◽  
High Energy ◽  
Future Application ◽  
Dispersing Agent ◽  
Higher Temperature ◽  
Average Size ◽  
Dispersing Agents

This paper reports the preliminary study on the synthesis of Ni doped CZTS (Cu2ZnSnS4:Ni) particle 5 at.% of Cu by solution method and dispersion of the obtained particles by beads mill method at various dispersing agents (SDS, CTAB, and Tween80). The phase transformation of the obtained particles was analyzed from the XRD spectra and XRF elemental analysis. The phase transformation and amount of Ni-doped to particles was predicted employing commercially available analytical software tool Match! Version 2.x. Moreover, the dispersion characteristics were investigated includes size, size distribution, and zeta potential of bare particles in comparison to various dispersing agents. This characteristic related to the future application of CZTS as an absorber in a thin-film based PV. The XRD analysis showed that the obtained particle contained crystal structure of copper sulfate pentahydrate (75.9 %), Ni(HN2S2)2 (12.5 %), and Cu2ZnSnS4 (11.6%). The XRF elemental analysis showed that amount of Ni-doped was 6.8 at.%; it was higher than the initial design amount of Ni doping. The dispersion of suspended particles was the majority (90%) with an average size of 3.06 µm and only 10 % with size 255 nm. Beads-milling of particles without dispersing agents did not disintegrate agglomerated particles. It is highlighted dispersion only using magnetic stirred with SDS dispersing agent provides the best suspension with a majority (60%) in 166 nm and only 30 % with average size 3.06 µm with relatively high zeta potential (-17 mV). It was concluded that the presence of a multi-phase crystal needs to be resolved either by proper calcination at a higher temperature than 400°C or further heating at a higher temperature during film preparation. High-energy centrifugation of zirconia beads mill caused desorption of adsorbed steric stabilization of dispersing agent under investigation. Further investigation on the coating process to facilitated laboratory fabrication of thin-film absorber with SDS as a dispersing agent is necessary to carry out concerning the properties of the thin-film.

Preparation and Tribological Properties of Surface-Coated Nano-Copper Additives

2008 ◽  
Vol 373-374 ◽  
pp. 580-584 ◽  
Author(s):  
Yi Xu ◽  
He Long Yu ◽  
Bin Shi Xu ◽  
Xiao Li Wang ◽  
Qian Liu
Keyword(s):  
Electron Microscope ◽  
Tribological Properties ◽  
Protective Film ◽  
Cu Nanoparticles ◽  
Transmission Electron ◽  
Load Carrying ◽  
Modification Technique ◽  
Average Size ◽  
Worn Surface ◽  
Worn Surfaces

In the present work, surface-coated Cu nanoparticles with FCC structure and an average size of 40 nm were prepared by reducing reaction and surface modification technique. The morphology and phase structure of the nano-copper were characterized by transmission electron microscope (TEM). The ball-on-disc tester and ring-on-block tester were performed to study the tribological properties of surface-coated Cu nanoparticles as oil additive. The tests were carried out under the lubrication of 50CC oil alone and oil containing surface-coated nano-copper additives. The morphologies and elementary distributions of the worn surfaces were analyzed by scanning electron microscope (SEM) and energy dispersive spectrometry (EDS), respectively. Results indicate that surface-coated nano-copper additives can significantly improve the wear resistance and load-carrying abilities of 50CC oil, as well as reduce friction coefficient. A soft copper protective film is formed on the worn surface lubricated with oil containing nano-copper additives, which separates the worn surfaces, avoids their direct contact and reduces friction and adhesive wear. Besides, the grooves and small valleys on the worn surfaces are found to be partly filled and repaired by nano-copper, as makes the worn surface repaired and smoother.

Effect of Precipitation Method on Stoichiometry and Morphology of Hydroxyapatite Nanoparticles

2007 ◽  
Vol 330-332 ◽  
pp. 271-274 ◽  
Author(s):  
He Bin Shi ◽  
Hong Zhong ◽  
Yu Liu ◽  
Jin Yan Gu ◽  
Chang Sheng Yang
Keyword(s):  
Aqueous Solution ◽  
Crystal Size ◽  
Ostwald Ripening ◽  
Precursor Solution ◽  
Reaction Vessel ◽  
Reaction Process ◽  
Precipitation Method ◽  
Precipitation Reaction ◽  
Hydroxyapatite Nanoparticles ◽  
Coprecipitation Process

This paper reports synthesis of hydroxyapatite nanoparticles by three precipitation methods. Homogeneous aqueous solution of Ca(NO3)2 and H3PO4 was used as precursor solution, and NH3•H2O was precipitator. Calcium deficient hydroxyapatite nanorods were obtained by adding the precipitator into precursor solution, near stoichiometric hydroxyapatite nanoparticles were derived from adding precursor solution into the precipitator, and smaller hydroxyapatite nanoparticles were prepared by adding precipitator and precursor solution simultaneously into a reaction vessel. The stoichiometry of hydroxyapatite was mainly affected by pH at precipitation reaction process. The crystal size and shape of hydroxyapatite particles was related to Ostwald ripening. The stoichiometry and morphology of hydroxyapatite nanoparticles can be controllable by selecting suitable coprecipitation process.

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