carrier medium
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2021 ◽  
Vol 2 (3) ◽  
pp. 548-552
Author(s):  
Ni Putu Wirastha Wisnuswari ◽  
I Nyoman Putu Budiartha ◽  
Desak Gede Dwi Arini

The practice of applying chemical substances to fruits to keep them fresh and look fresh is still being discovered. This form of fraud can occur and can pass into the fruit market in Indonesia in the absence of an agency that specifically pays attention to and carries out quarantine. The purposes of this study are to reveal the plant quarantine arrangements in the provisions of the legislation on the supervision and model for imported fruit that will be marketed and consumed by the public. The type of research used in this research is normative legal research. Sources of legal materials used are primary, secondary and tertiary sources of law. The technique of collecting legal materials used in this research is the technique of document study and literature study. After the data is collected, then it is analyzed descriptively. The results of the study show that the regulation of plant quarantine is in the Law of the Republic of Indonesia Number 21 of 2019 concerning Animal, Fish and Plant Quarantine and is also regulated in Government Regulation Number 14 of 2002 concerning Plant Quarantine. The control model for imported fruit to be marketed and consumed by the public is carried out according to the procedure, namely that each carrier medium (plants and their parts and/or other objects) is subject to plant quarantine, physical/visual inspection is carried out and continued with health checks according to the OPTK target.


Author(s):  
М.Г. Бергер

Начальная массовая скорость компактного движения выброшенного ледово-каменного материала ледника Колка, достигнутая на стадии газового ускорения в эпицентральной зоне взрывоподобного внезапного газодинамического выброса ледника, составляла около 300 м/с. Именно столь высокие значения величины начальной массовой скорости выброса основного количества ледово-каменного материала определили возможность образования сопутствовавшей выбросу ударной воздушной волны, которая и на большом расстоянии от эпицентра выброса (порядка 15 км) все еще имела значительную интенсивность. Воздушным был характер несущей среды для всего Геналдонского лавинообразного потока в пределах выделенной прежде всего по этому признаку зоны транзита на всем многокилометровом ее протяжении, а для начальной и основной стадий выброса – и за пределами этой зоны (до Скалистого хребта). Дальность же действия взрывоподобного внезапного газодинамического выброса ледника Колка 20 сентября 2002 года, безусловно, не ограничивалась лишь вместилищем ледника Колка или Колкинским цирком, как иногда полагают, а захватывала огромную территорию Колкинского и Геналдонского ущелий и была ограничена (да и то не полностью) лишь непреодолимой механической преградой Скалистого хребта. Цель работы. В плане сопоставления с взрывоподобными направленными газодинамическими выбросами ледников рассматривается вопрос об истории изучения направленных вулканических взрывов, установленных полстолетием ранее. Методы работы. Проведен анализ имеющихся данных и существующих походов их оценок. Результаты работы. Показана огромная мощность взрывоподобных направленных газодинамических выбросов ледника Колка, вполне сопоставимых в данном отношении с крупными направленными вулканическими взрывами. The initial mass velocity of the compact movement of the ejected glacial-stone material of the Kolka glacier, reached at the stage of gas acceleration in the epicentral zone of the sudden explosion-like gas-dynamic surge of the glacier, was about 300 m/s. Exactly such high values of the initial mass velocity of the surge of the main amount of glacial-stone material that determined the possibility of the formation of an accompanying ejection of the air-blast, which had a significant intensity even at a great distance from the surge epicenter (about 15 km). The nature of the carrier medium for the entire Genaldon avalanche flow was aerial within the transit zone distinguished primarily according this character along its entire length of many kilometers; and for the initial and main stages of the surge the nature was the same outside this zone (up to the Skalisty (Rocky) Ridge). The range of action of the sudden explosion-like gas-dynamic surge of the Kolka glacier on September 20, 2002, was certainly not limited only by the reservoir of the Kolka glacier or the Kolka cirque, as it is sometimes supposed, but captured the vast territory of the Kolka and Genaldon gorges and was limited (and even then not completely) only by the insurmountable mechanical barrier of the Skalisty (Rocky Ridge). Aim. In terms of the comparison with explosion-like directional gas-dynamic surges of glaciers, the article considers an issue of the history of study of directional volcanic explosions determined half a century earlier. Methods. The analysis of the available data and the existing approaches for their assessments was carried out. Results. The results of the work show the enormous power of explosion-like directed gas-dynamic surges of the Kolka glacier, which are quite comparable in this respect with large directed volcanic explosions.


Author(s):  
D. A. Tukmakov ◽  
N. A. Tukmakova

The study is devoted to the study of the effect of coagulation of dispersed phase droplets on aerosol oscillations in an acoustic resonator. The mathematical model of aerosol dynamics implements a continuous mathematical model of the dynamics of a multiphase medium, taking into account the velocity and thermal inhomogeneity of the mixture components. To describe the dynamics of the carrier medium, a two-dimensional unsteady system of Navier – Stokes equations for a compressible gas is used, written taking into account the interphase force interaction and interphase heat transfer. To describe the dynamics of the dispersed phase, a system of equations is solved for each of its fractions, including the continuity equation for the «average density» of the fraction, the equations for the conservation of the spatial components of the momentum and the equation for the conservation of thermal energy of the fraction of the dispersed phase of the gas suspension. The interphase force interaction included the Archimedes force, the force of the added masses and the force of aerodynamic drag. The heat exchange between the carrier medium - gas and each of the dispersed phase fractions was also taken into account. The mathematical model of the dynamics of a polydisperse aerosol was supplemented by a mathematical model of collisional aerosol coagulation. For the velocity components of the mixture components, uniform Dirichlet boundary conditions were specified. For the remaining functions of the dynamics of the multiphase mixture, homogeneous Neumann boundary conditions were specified. The equations were solved by the explicit McCormack method with a nonlinear correction scheme that allows obtaining a monotonic solution. As a result of numerical calculations, it was determined that a region with an increased content of coarse particles is formed in the vicinity of the oscillating piston. The coagulation process leads to a monotonic increase in the volumetric content of the fraction of coarse particles and a monotonic decrease in the volumetric content of fine particles.


2021 ◽  
Vol 1 (1) ◽  
pp. 73-80
Author(s):  
D.A. Tukmakov ◽  

The paper is devoted to the study of the effect of the intensity of aerosol fluctuations on the dis-tribution of fractions of the dispersed component of the coagulating aerosol. Oscillations of aerosol in closed channel are numerically modeled in operation. To describe the dynamics of the carrier medium, a two-dimensional non-stationary system of Navier-Stokes equations for compressed gas is used. They are written taking into account interfacial power interaction and interfacial heat ex-change. To describe the dynamics of the dispersed phase, a system of equations is solved for each of its fractions. It includes an equation of continuity for the “average density” of the fraction, equa-tions of preservation of spatial components of the pulse and an equation of preservation of thermal energy of the fraction of the dispersed phase of the gas suspension. Phase-to-phase power interac-tion included Archimedes force, attached mass force, and aerodynamic drag force. Heat exchange between the carrier medium-gas and each of the fractions of the dispersed phase was also taken into account. The mathematical model of dynamics of polydisperse aerosol was supplemented by the mathematical model of collision coagulation of aerosol. For the velocity components of the mixture, uniform Dirichlet boundary conditions were set. For the remaining functions of the dynamics of the multiphase mixture, uniform Neumann boundary conditions were set. The equations were solved by the explicit McCormack method with a nonlinear correction scheme that allows to obtain a mono-tone solution. As a result of numerical calculations, it was determined that in the vicinity of the os-cillating piston, an area with an increased content of coarse particles is formed. The coagulation process results in a monotonous increase in volume content of the coarse particle fraction and a mo-notonous decrease in volume content of fine particles. Increasing the intensity of gas fluctuations leads to intensification of the process of coagulation of aerosol droplets.


Author(s):  
V.A. Arkhipov ◽  
◽  
S.A. Basalaev ◽  
K.G. Perfilieva ◽  
A.S. Usanina ◽  
...  

The results of an experimental study of gravitational settling of a cooled (T = 82 K, 250 K) and a heated (T = 373 K, 473 K, 573 K) steel ball in glycerin and polymethylsiloxane liquids (PDMS-10000, PDMS-30000) in the range of the Reynolds numbers Re = 10−3–1 are presented. It is shown that the stationary velocity of gravitational settling of a particle decreases with its cooling and, conversely, it increases with heating of the particle. A time dependence of the distance traveled by the particle is found to be linear for both heated, cooled, and etalon (T = Tl) solid spheres. The effect of the difference in the particle and carrier medium temperatures on the drag coefficient of the solid sphere is analyzed. For the considered Reynolds numbers, it is revealed that the drag coefficient of a single solid sphere is determined by CD = a /Re , where a is the empirical coefficient depending on the ratio of the particle and liquid temperatures T = T /Tl . Using the regression analysis method, the expression for a drag coefficient of a solid particle under non-isothermal conditions at T >> 1 is found to be similar to the Hadamard –Rybczynski expression CD = 16/Re, which is obtained for a spherical bubble (or a drop). The empirical dependences of the drag coefficient for a cooled and a heated solid sphere on the difference in the particle and liquid temperatures δТ = 1− T are obtained.


2020 ◽  
Vol 22 ◽  
Author(s):  
Majdi Al-Amili ◽  
Zhu Jin ◽  
Zhongmin Wang ◽  
Shengrong Guo

: Generally, poor solubility and imprecise delivery of chemotherapeutic drugs can compromise their efficacies for clinical cancer treatment. In order to address such concerns, poor water-soluble drugs are conjugated with poly(ethylene glycol) (PEG) to obtain PEGylated drugs, which have improved water solubility and can also self-assemble in aqueous solution to form micelles (PEGylated drug micelles). The surface PEG layer enhances the micelles’ colloidal stability and reduces the interaction with physiological surroundings. Meanwhile, PEGylated drug micelles are tumor-targeting via the enhanced permeation and retention (EPR) effect to improve antitumor efficacy in comparison with free drugs. PEGylated drug micelles employ drugs as parts of the carrier medium, which increases the micelles’ drug loading capacity relatively. The development of stimuli-responsive PEGylated drug micelles facilitates the drug release to be smart and controllable. Moreover, the PEGylated drug micelles show great potentials in overcoming the challenges of cancer therapy, such as multidrug resistance (MDR), angiogenesis, immunosuppression, and so on. In this review, we highlight the research progresses of PEGylated drug micelles, including the structures and properties, smart stimuli-responsive PEGylated drug micelles, and the challenges that have been overcome by PEGylated drug micelles.


Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5317
Author(s):  
Siti Khumaira Mohd Jamari ◽  
Nur Azmah Nordin ◽  
Ubaidillah ◽  
Siti Aishah Abdul Aziz ◽  
Nurhazimah Nazmi ◽  
...  

Magnetorheological (MR) material is a type of magneto-sensitive smart materials which consists of magnetizable particles dispersed in a carrier medium. Throughout the years, coating on the surface of the magnetic particles has been developed by researchers to enhance the performance of MR materials, which include the improvement of sedimentation stability, enhancement of the interaction between the particles and matrix mediums, and improving rheological properties as well as providing extra protection against oxidative environments. There are a few coating methods that have been employed to graft the coating layer on the surface of the magnetic particles, such as atomic transfer radical polymerization (ATRP), chemical oxidative polymerization, and dispersion polymerization. This paper investigates the role of particle coating in MR materials with the effects gained from grafting the magnetic particles. This paper also discusses the coating methods employed in some of the works that have been established by researchers in the particle coating of MR materials.


Author(s):  
Muhammad Akhsan Akib ◽  
Andi Nuddin ◽  
Retno Prayudyaningsih

Utilization of arbuscular mycorrhizal spores carrier media which has heavyweight, not optimal utilization of organic material as arbuscular mycorrhiza inoculant carrier, and founded of arbuscular mycorrhizal spores which have wide adaptability and tolerance on land contaminated with heavy metals are the basis for implementation of this research. The aim of this research was to determine combination of organic culture media which is good for increasing the abundance and diameter of indigenous Gigaspora sp. This research was carried out at Universitas Muhammadiyah Parepare, and Balai Penelitian dan Pengembangan Lingkungan Hidup dan Kehutanan Makassar. The research was compiled using a completely randomized design. The combination treatment of organic culture media used was a combination of rice husk charcoal, sand, zeolite; rice husk charcoal, sand, sawdust; rice husk charcoal, sand, cocopeat; rice husk charcoal, sand, paddy soil; rice husk charcoal, sand, cold larva. The results showed that combination of rice husk charcoal, sand, cocopeat; and combination of rice husk charcoal, sand, paddy soil gives the best results on growth and development of Gigaspora spores. Combination of rice husk charcoal, sand, and cocopeat, can be recommended as media an effective, efficient, and inexpensive spore carrier medium, but should be used after decomposing into compost.


BioControl ◽  
2020 ◽  
Vol 65 (6) ◽  
pp. 737-749
Author(s):  
Lisa Joos ◽  
Gisèle L. Herren ◽  
Marjolein Couvreur ◽  
Isabelle Binnemans ◽  
Feyisara Eyiwumi Oni ◽  
...  

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