extraction coefficient
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2021 ◽  
Vol 2064 (1) ◽  
pp. 012116
Author(s):  
S Yu Doroshkevich ◽  
M S Vorobyov ◽  
M S Torba ◽  
N N Koval ◽  
S A Sulakshin ◽  
...  

Abstract The use of a modern element base makes it possible to create power supplies with a transition from a direct mode of generation of an auxiliary discharge to a pulse-periodic mode with a pulse repetition rate at the level of several tens of kHz. This allows for a more flexible adjustment of the discharge parameters, keeping the average value of its current, but changing its amplitude with a corresponding change in the pulse duty cycle. In this work, using an electron accelerator based on ion-electron emission, generating a wide-aperture electron beam, we research the effect of auxiliary discharge generation mode (direct and pulse-periodic) on the efficiency of electron beam extraction into the ambient atmosphere. It is shown that, in a direct mode of electron beam generation at an accelerating voltage of 150 kV, the beam extraction coefficient does not exceed 0.25. The possibility of increasing the extraction coefficient to K = 0.55 at the same accelerating voltage of 150 kV was demonstrated without making changes to the design of the accelerator, but switching to a pulsed-periodic mode of emission plasma generation.



Author(s):  
Zahra Abbasi ◽  
Jan Bocianowski

AbstractThe objective of this study was to assess genotype by environment interaction for 21 physiological traits in sugar beet (Beta vulgaris L.) parents and hybrids grown in Rodasht Agricultural Research Station in Iran by the additive main effects and multiplicative interaction model. The study comprised of 51 sugar beet genotypes [10 multigerm pollen parents, four monogerm seed parents and 36 F1 hybrids], evaluated at four environments in a randomized complete block design, with three replicates. The additive main effects and multiplicative interaction analyses revealed significant environment main effects with respect to all observed traits, except extraction coefficient of sugar. The additive main effects and multiplicative interaction stability values ranged from 0.009 (G17 for leaf Ca2+) to 9.698 (G09 for extraction coefficient of sugar). The parental forms 2 7233-P.29 (G38) and C CMS (G49) as well as hybrids 2(6)*C (G27) and 5*C (G33) are recommended for further inclusion in the breeding programs because of their stability and good average values of observed traits.



2021 ◽  
pp. 60-64
Author(s):  
Геннадий Тимофеевич Земский ◽  
Владимир Александрович Зуйков ◽  
Наталья Валентиновна Кондратюк ◽  
Александр Владимирович Зуйков

Темой данной статьи является рассмотрение расчетного метода оценки пыленакопления в помещении с оборудованием, содержащим дисперсные материалы, а задача заключается в его совершенствовании на основании современных представлений. Витающие в воздухе мелкие пылинки постепенно осаждаются на горизонтальных поверхностях, создавая угрозу внезапного перехода в состояние аэровзвеси и взрывообразного сгорания с образованием волны давления. Для определения категории помещения по взрывопожарной и пожарной опасности и разработки профилактических противопожарных мероприятий необходимо иметь математический инструмент, позволяющий оценивать количество пыли, которое может участвовать во взрыве. В статье предлагается определять критический диаметр частиц пыли, исходя из равенства скорости осаждения частиц и скорости распространения пламени. При этом скорость осаждения частиц следует определять по известному соотношению Стокса, а скорость распространения пламени принимать или по данным эксперимента, или среднестатистическую, равную 3 м/с. The dust that settles on the horizontal surfaces of equipment and building structures is inevitably contained in the premises in which technological process is carried out with the presence of combustible dispersed materials. The amount of dust deposited in a room can be determined in several ways. 1. Weighing the dust collected during cleaning. 2. Experimentally by placing dust collectors on different surfaces for a certain period of time. It should be considered the incompleteness of the previous dust collection, which depends on the dust collection method when determining the amount of dust deposited in the room. The amount of the remaining uncollected dust is estimated as 10 % of the detected dust if the cleaning was carried out by a mechanized method (dust extraction coefficient K = 0.9, and insufficient decontamination coefficient n = 0.1). The amount of remaining uncollected dust is estimated as 40% of the detected dust if cleaning was carried out manually using a dry method (dust extraction coefficient K = 0.6 and insufficient decontamination coefficient n = 0.4). The amount of remaining uncollected dust is estimated as 30% of the detected dust if the cleaning is carried out manually with a wet method (K coefficient = 0.7, and insufficient decontamination coefficient n = 0.3). Dust factor is the ratio of amount of dust suspended in the airspace to the total amount of dust in the room. It should be taken equal to 0.5, if the diameter of dust particles is more critical, and equal to 1, if the diameter of dust particles is less than the critical diameter. The diameter of the dust particles is critical, above which the dust ceases to spread the flame. The critical diameter can be determined based on the following considerations. Flame propagation through the air suspension will not occur if the particle deposition rate exceeds the flame propagation rate from bottom to top. The deposition rate is easily determined by the Stokes coefficient. The flame propagation rate can be determined experimentally or estimated as slightly higher than the average for most industrial dusts. The authors obtain a formula for calculating the critical diameter of dust particles equating the terminal velocity to flame propagation rate (3 m/s) and solving the Stokes equations of the particle diameter. The critical particle diameter of air suspension of combustible materials in most cases does not exceed 300 microns at flame propagation speed of 3 m/s. The obtained calculated values of the critical diameters are in satisfactory agreement with the literature data, and also confirm the correctness of the choice of dust formation coefficient K = 1 for dust with dispersion of less than 350 mkm. The air suspension ready for a secondary explosion is formed when combustible particulate material leaves the equipment as a result of an internal explosion. The aerosol with a high concentration of solid phase is formed in case of free precipitation from the device or from damaged packaging located above the floor level of the room. In this case, the amount of fuel capable for explosive combustion is determined by the amount of oxygen in the cloud, since the diffusion supply of oxygen from the outside does not have time to ensure complete combustion of the fuel. When the product spills unhindered, the resulting cloud has the shape of a volumetric cone with a base diameter equal to the height of the cone. It is possible to determine the amount of burned dust knowing the stoichiometric concentration of dust (%) required for its combustion per unit of air volume, as well as the volume of the dust cloud (V). The Pc value can be determined by the combustion reaction if the chemical composition of the dust is known. There are proposed refined equations for determining the critical diameter of combustible dust, the stoichiometric concentration during its combustion in a unit of air volume as well as the mass of dust deposited in the room. It is recommended to estimate the value of the stoichiometric concentration according to the combustion heat of dust for dusts of indeterminate chemical composition.



2020 ◽  
Vol 3 (1) ◽  
pp. 84-94 ◽  
Author(s):  
Laura Carrara ◽  
Christian Giroud ◽  
Nicolas Concha-Lozano

Cannabis sativa is known for its recreational use, but also for its therapeutic potential. There has been wide discussion over the use of cannabis for medical purposes in recent years, especially because a consensus has not been reached regarding its risk/benefit balance. Among the more common modes of administration, vaping with a vaporiser is most frequently used for self-medication. Vaping seems to be a better alternative to preventing adverse health effects due to toxic compounds produced during combustion when cannabis is smoked. However, the delivery kinetics and efficiency of most portable vaporisers are not fully characterised with an appropriate vaping regime. This determination requires a specific vaping machine operating under realistic puffing conditions. In this study, a vaping machine was conceived to fit with the common uses of portable vaporisers that requires conditions different from those used for electronic cigarettes. The experimental setup in this study was optimised to sample aerosolised cannabinoids. The delivery kinetics, efficiency, and decarboxylation yields of two commercially available vaporisers (DaVinci® and Mighty Medic®) were evaluated for delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Among all tested sampling supports, the glass fibre filter is the most efficient medium to collect mixed THC and CBD aerosols. From the delivery kinetics of cannabinoids, a single-parameter model was used to calculate the extraction coefficient of each vaporiser. The results show that the Mighty Medic® vaporiser had a higher extraction coefficient (0.39) and a more immediate release of cannabinoids than the DaVinci® vaporiser (0.16), which had a gradual and slower rate of vaporisation. This parameter could be a quantitative input in pharmacokinetic models of administration of volatile compounds using vaporisers and a useful tool for the comparison of vaporisers.



Author(s):  
Amir Rahimi ◽  
Sina Siavash Moghaddam ◽  
Seyyed Ali Noorhosseini ◽  
Mortaza Hajyzadeh

Plants need different macro and micro nutrient elements to grow and reproduce. Their malnutrition results in unhealthy growth. The soils of Naqadeh area, Iran are deficient in micronutrient elements. The aim of the study was to evaluate the effects of micronutrients application on some qualitative and quantitative parameters of economically important monogerm sugar beet cv. Sonja. The plants were foliar sprayed with iron, boron, zinc, and manganese. The studied traits were potassium, sodium, nitrogen, extraction coefficient, sugar percent, recoverable sugar, alkalinity, molasses, root yield, and white sugar recovery yield. The effect of micronutrients was significant on all studied traits. The highest extraction coefficient of 89.31 was related to the foliar application of iron (Fe) and the highest recoverable sugar percent (16.91%) was obtained from Zn application. Also, the highest mean root yield (74.120 t ha-1) and white sugar yield (12.137 t ha-1) were noted after foliar treatments of boron (B) and Fe, respectively.



2018 ◽  
Vol 18 (3) ◽  
pp. 503 ◽  
Author(s):  
Naseer Inuwa Durumin Iya ◽  
Zaini Bin Assim ◽  
Isa Bin Ipor ◽  
Ajoke Omonrinoye Omolayo ◽  
Isaac John Umaru ◽  
...  

This study was to investigate survival, growth and accumulation potential of Acalypha wilkesiana in phytoextraction of heavy metals contaminated soil. Acalypha wilkesiana was tested to evaluate its tolerance and phytoextraction capacity in soils contaminated with metals. It was tested under 10 mL of 100 mg/kg of As, Cr, Cd, Co, Cu, Fe, Mn, Ni, Pb, and Zn solution, along 240 days in greenhouse experiment with harvesting period of 60 days interval. Twenty four cuttings from Acalypha wilkesiana were subjected to the same treatment. Plants roots stem and leaves were dry-digested and analyzed using Atomic Absorption Spectrophotometer (AAS). Results show that Fe was the most accumulated metal followed by Cu, Mn, As and Zn with 5002.4, 542.7, 492.2, 396.7 and 308.2 mg/kg, respectively. The concentration of Cr, Ni, and Co was 101.2, 99.09, and 89.63mg/kg respectively. The highest concentration of Pb was 46.44 mg/kg, Cd was not detected by the plant. Bioconcentration Factor (BCF) of metals were above unity in root, stem, and leaf except for Fe which showed a value below the unity, and Pb shows highest BF value of 7.79. The Translocation Factor (TF) of Cr, Co, Fe, Ni, and Pb were higher, while that of As, Cu, Mn, and Zn were below the unity, Co showed the highest value of 15.93. Furthermore, Extraction Coefficient (EC) of Cr, Co, Ni, and Pb were greater than 1, while for remaining metals were lower than unity, the highest EC was observed from Pb with a value 17.21.



2014 ◽  
Vol 1015 ◽  
pp. 476-479
Author(s):  
Du Shu Huang ◽  
Jin Hong Yin ◽  
Xian Shu Lv ◽  
Yan Xu ◽  
Jie Wu

The extraction process of cobalt using microemulsion system saponified with P507 as extracting agent was studied. The influences of initial concentration, the concentration of P507, initial pH, the extracting time and the volume ratio of organic phase to water phase on extraction coefficient were also studied. Experimental results show that the saponification microemulsion system using P507 as extractant is thermodynamic stable, and it can separate cobalt better. The optimum conditions were achieved as: the initial concentration is 0.04 mol/L, pH is 2; The concentration of P507 is 6%, extraction time is 6 min; The volume ratio of organic phase to water phase is 1.5:1.



2012 ◽  
Vol 496 ◽  
pp. 407-410
Author(s):  
Du Shu Huang ◽  
Jin Gang Yu ◽  
Rui Min Xiao ◽  
Zi Jing Li ◽  
Li Da Sun

The extraction process of cobalt using microemulsion system saponified with P204 as extracting agent was studied. The influence of initial concentration, the concentration of P204, initial pH, the extracting time and the concentration of cobalt and nickel on extraction coefficient were also studied. Experimental results show that the saponification microemulsion system using P204 as extractant is thermodynamic stable, and it can separate cobalt better. The optimum conditions were achieved as: the initial concentration is 0.05 mol/L, pH is 2; The concentration of P204 is 10%, extraction time is 10 min; The volume ratio of organic phase to water phase is 2:1.



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