scholarly journals EFFECT OF OXIDANT RELATIVE FLOW RATE ON OBTAINING RAW MATERIAL FOR PULVERIZED COAL PRODUCTION FROM HIGH-SULFURIC LOW GRADE COAL

2017 ◽  
Vol 11 (2) ◽  
pp. 236-241 ◽  
Author(s):  
Mariіa Shved ◽  
◽  
Serhiy Pyshyev ◽  
Yuriy Prysiazhnyi ◽  
◽  
...  
2020 ◽  
pp. 69-73
Author(s):  
Svetlana Mikhailovna Dragunova ◽  
Yevgeniy Vladimirovich, Кuznetsov ◽  
Anna Yevgenievna Khadzhidi

The article solves the problem of increasing the level of protection of juvenile fish to a standard indicator by the modernization of individual elements of fish protection of ameliorative water intake of irrigation systems. The design of an integrated fish-protecting structure with a logging boom adapted to hydrology and the rhythm of migration of juvenile fish from irrigation sources has been proposed. The results of studies on a physical model, taking into account the costs of the reclamation system, show an increase in the efficiency of the combined fish protection structure with a harbor for reclamation water intakes in the range of 78,5–84,0 %, depending on the relative flow rate on the shelf of the sanctuary.


1969 ◽  
Vol 47 (3) ◽  
pp. 261-265 ◽  
Author(s):  
Peter Gaskell ◽  
Kathleen L. Long

One hand of each of 10 subjects was immersed in stirred water at 4 °C for 1 h per day, 5 days per week, for 3 weeks, to produce local acclimatization to cold. The opposite hand was immersed at the same time in water at 32 °C. The reactivity of digital vessels in a finger of each hand was measured as the increase in the critical opening pressure of the vessels in response to an intravenous infusion of noradrenaline at 2 and 5 μg/min. The reactivity of digital vessels in the test hand was compared with that in the control hand both before and after the repeated cold exposure of the test hand to see whether the cold exposure altered the reactivity of vessels in the test hand relative to that in the control hand. No evidence of such a relative change was obtained. Resting blood flow at 21 and 32 °C in the test hand was compared with that in the control hand both before and after the repeated cold exposure. No change in the relative flow rate in the two hands was observed as a result of the cold exposure. Roentgen studies of the hands did not reveal any effect of the repeated cold exposure on the mineralization of the bones of the hands.


2021 ◽  
Vol 2(50) ◽  
Author(s):  
Nikolay Bachev ◽  
◽  
Alena Shilova ◽  
Oleg Matyunin ◽  
Oksana Betinskaya ◽  
...  

An integral part of any open-type gas turbine plant is a low-emission combustion chamber, which is usually two-zone and cooled. One of the ways to reduce emission of harmful substanc-es is organizing low-emission low-temperature lean combustion with external heating of compo-nents. This paper investigates the effect of external heating of air and fuel gas on expansion of the lower combustion limit and stable flame position in a single-zone uncooled combustion chamber of a microgas turbine power plant. Stable position of the flame front in combustion chambers of this type mainly depends on the ratio between the average flow rate of the combus-tible-air mixture and the rate of turbulent combustion. This ratio depends on thermal, gas-dynamic, thermochemical and geometric factors. The purpose of this work is to substantiate the possibility of using the relative flow rate as a generalized characteristic. This goal was achieved in processing a large amount of published experimental data and numerical modeling of low-temperature combustion of lean mixtures. The most significant research result is determination of the range of relative flow rate (gk = 0.3…3.5·10-4 kg⁄s∙N), at which it is possible to ensure sta-ble flame position in a single-zone combustion chamber. Significance of the obtained results lies in the fact that using the relative flow rate makes it possible to quickly determine and analyze the geometric and gas-dynamic parameters and characteristics of turbulent combustion in com-bustion chambers of micro-gas turbine power plants.


Author(s):  
Danniely O. Costa ◽  
Rafael O. Batista ◽  
Hudson S. M. Vale ◽  
Amanda B. de Sousa ◽  
Solange A. G. Dombroski ◽  
...  

ABSTRACT This study aimed to recover the flow rate of clogged drippers with different doses and permanence times of the product MaxBio. The experiment was conducted in a completely randomized design in split-split-plot scheme, where the plots corresponded to product doses (80, 160, 240 and 320 mg L-1), subplots to the applied treatments (T1 - without biological treatment, T2 - 1st application of the product, and T3 - 2nd application of the product) and in sub-subplots the types of emitters (Plastro Hydrodrip Super, Netafim Tiran and Netafim PCJ-CNJ), with three replicates. The four irrigation units operated with treated domestic wastewater for 400 h in order to clog the emitters. After applying the product MaxBio, the flow rate of the drippers and the relative flow rate reduction were determined to express the unclogging levels. There was significant effect of T2 and T3 on the recovery of the flow rate of the drippers, while for the reduction of relative flow rate, the doses of the product did not show statistical difference regarding the types of drippers.


2012 ◽  
Vol 134 (8) ◽  
Author(s):  
Muheng Zhang ◽  
Yongsheng Lian ◽  
Cindy Harnett ◽  
Ellen Brehob

The Coulter technique enables rapid analysis of particles or cells suspended in a fluid stream. In this technique, the cells are suspended in an electrically conductive solution, which is hydrodynamically focused by nonconducting sheath flows. The cells produce a characteristic voltage signal when they interrupt an electrical path. The population and size of the cells can be obtained through analyzing the voltage signal. In a microfluidic Coulter counter device, the hydrodynamic focusing technique is used to position the conducting sample stream and the cells and also to separate close cells to generate distinct signals for each cell and avoid signal jam. The performance of hydrodynamic focusing depends on the relative flow ratio between the sample stream and sheath stream. We use a numerical approach to study the hydrodynamic focusing in a microfluidic Coulter counter device. In this approach, the flow field is described by solving the incompressible Navier-Stokes equations. The sample stream concentration is modeled by an advection-diffusion equation. The motion of the cells is governed by the Newton-Euler equations of motion. Particle motion through the flow field is handled using an overlapping grid technique. A numerical model for studying a microfluidic Coulter counter has been validated. Using the model, the impact of relative flow rate on the performance of hydrodynamic focusing was studied. Our numerical results show that the position of the sample stream can be controlled by adjusting the relative flow rate. Our simulations also show that particles can be focused into the stream and initially close particles can be separated by the hydrodynamic focusing. From our study, we conclude that hydrodynamic focusing provides an effective way to control the position of the sample stream and cells and it also can be used to separate cells to avoid signal jam.


Author(s):  
Ye. І. Kryzhanivskyi ◽  
D. О. Panevnyk

The article presents the sequence of deriving the equations which characterize the hydraulic system of jet pumps that carry out suction and injection-suction bottom flushing while drilling the production wells. The nature of flow distribution in the borehole ejection systems of the suction and injection-suction types is analyzed. The analysis is carried out taking into consideration the peculiarities of the calculation of branched hydraulic systems. While studying the movement of the flows in the bottom circulation circuits, the authors take into account the equation of the balance of the flow-rate at nodal points and hydraulic losses in parallel parts of the system. The developed mathematical models are based on the study of the changes in hydrodynamic pressures which occur in characteristic sections of a jet pump. The pressure ratio of mixed, injected and operating flows is presented as non-dimensional relative pressure of the ejection system. The dependence of non-dimensional relative pressure on the relative flow rate determines the characteristic of the hydraulic system of a jet pump. The relative flow rate or injection ratio of a jet pump is defined as the ratio of flow rate to injected and work flow. While analyzing the developed mathematical models, the authors specify the relation between the design and operating parameters of a jet pump. These parameters ensure its operation with maximum efficiency. Based on the study of the influence of the correlation between the diameters of the jet pump nozzles and the flushing system of the bit, the authors specify parameters which are optimal in terms of energy performance. The article provides the example of graphical determination of the operating point of a pumping unit. This determination is based on a simultaneous solution of the equations of the characteristics of the jet pump and the hydraulic system in which it operates. The improved techniques allow to predict the mode parameters of ejection systems and to determine the size of flowing part of the jet pump. They provide maximum energy performance of its workflow.


Processes ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 290 ◽  
Author(s):  
Courtney van Ballegooie ◽  
Alice Man ◽  
Irene Andreu ◽  
Byron D. Gates ◽  
Donald Yapp

The synthesis of Zein nanoparticles (NPs) using conventional methods, such as emulsion solvent diffusion and emulsion solvent evaporation, is often unreliable in replicating particle size and polydispersity between batch-to-batch syntheses. We have systematically examined the parameters for reproducibly synthesizing Zein NPs using a Y-junction microfluidics chip with staggered herringbone micromixers. Our results indicate that the total flow rate of the fluidics system, relative flow rate of the aqueous and organic phase, concentration of the base material and solvent, and properties of the solvent influence the polydispersity and size of the NPs. Trends such as increasing the total flow rate and relative flow rate lead to a decrease in Zein NP size, while increasing the ethanol and Zein concentration lead to an increase in Zein NP size. The solvent property that was found to impact the size of the Zein NPs formed the most was their hydropathy. Solvents that had a hydropathy index most similar to that of Zein formed the smallest Zein NPs. Synthesis consistency was confirmed within and between sample batches. Stabilizing agents, such as sodium caseinate, Tween 80, and Pluronic F-68, were incorporated using the microfluidics system, necessary for in vitro and in vivo use, into Zein-based NPs.


Author(s):  
Marinaldo F. Pinto ◽  
Bruno Molle ◽  
Dinara G. Alves ◽  
Nassim Ait-Mouheb ◽  
Antonio P. de Camargo ◽  
...  

ABSTRACT The clogging dynamics of pressure-compensating drippers is still poorly addressed, and its understanding is quite important to control clogging. The aim of this study was to evaluate the flow performance of pressure-compensating drippers under clogging effect. Eight pressure-compensating emitters, model J-SC Jain PC-PLUS with nominal flow rate of 2.2 L h-1 were evaluated. The tests were run for 8 h d-1 for 4 weeks, a total of 160 h. Every 40 h, the concentration and granulometry of suspended particles were increased, by adding 125 mg L-1 of solids, composed of sand. The flow rate of the emitters was determined using a weight measurement system. Flow rate variations of the emitters did not follow a defined pattern. Clogging seems to occur randomly and abruptly. Sometimes the flow rate exceeded the nominal value (maximum relative flow rate of 182%) and other times it was lower than the nominal value (minimum relative flow rate of 0%).


2020 ◽  
Vol 07 ◽  
Author(s):  
Li Qiannan ◽  
Ling Yeqing ◽  
Zheng Hewen ◽  
Yang Zhi

: Manganese ore is an important metallurgical raw material that holds an important strategic position in the national economy of China. However, the grade of manganese ore in the country is mostly low, and the utilization efficiency of lowgrade manganese ore resources is low, which seriously restrict the healthy and stable development of China’s metallurgical industry. As a new green heating method, microwave is expected to address the problems of conventional methods and realize the effective utilization of low-grade manganese ore. In this paper, the research status of the microwave composite reduction of pyrolusite in recent years is reviewed. Microwave plays an important role in metallurgy, and it is the current direction pursued to improve the research intensity of microwave heating and extend it to actual industrial processes.


Sign in / Sign up

Export Citation Format

Share Document