共查询到20条相似文献,搜索用时 0 毫秒
1.
Yu. V. Kosmodem'yanskii A. P. Fokin A. N. Planovskii 《Journal of Engineering Physics and Thermophysics》1968,14(1):19-22
A comparison is made between the processes of adiabatic evaporation of a polydisperse system of droplets and a monodisperse system with droplets equal in size to the largest droplet of the polydisperse system. The process takes place in air with the same initial and final parameters in both cases. 相似文献
3.
A. M. Abramets I. I. Lishtvan A. A. Terent'ev N. V. Churaev 《Journal of Engineering Physics and Thermophysics》1982,42(2):192-196
A study has been made of the effects of surfactants SA of various types on the drying kinetics and structuring in peat.Translated from Inzhenerno-Fizicheskli Zhurnal, Vol. 42, No. 2, pp. 279–285, February, 1982. 相似文献
4.
In a new design of printhead with ER fluid acting as a working medium, the actuating element and the ER fluid valve control the ink droplet ejection [Smart Mater. Struct. 9 (2000) 839–847]. In this paper, the transient behavior of the ER valve printhead incorporated with ink chamber is investigated. The pattern of ink droplet ejected from the printhead is examined by using the digital optical system for visualization. A quasi-static modeling of the system based on the bulk compressibility of the fluid and the stiffness of the elastic membrane is performed. The fluid pressure in the ink chamber is investigated, both theoretically and experimentally under the following controlled parameters: the actuating voltage and frequency of the piezoelectric transducer; and the controlled electric field strength of the ER value. It is found that the velocity of the ejected ink droplet increases with actuation voltage applied to the piezoelectric transducer. And a better ink droplet without satellite can be obtained with voltage impulse of magnitude 4 V, and pulse width of 6.5 ms. On the other hand, by applying 200 V/mm electric field on the ER valve, the ink ejection can be effectively stopped. Although the frequency of the ink ejection is limited to less than 10 Hz, due to the dynamic resonance of the system, it is believed that the operating bandwidth can be further raised by minimizing the dimensions of the system. 相似文献
5.
The microstructure of spray-dried model granules, comprising silica microspheres and poly (vinylalcohol), was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) with an ultramicrotome technique. Disintegration of granules was characterized by a shear method for granular beds, and by a compression test for single granules. The internal structure changed significantly with the pH of the slurry from which the granules were spray-dried. Granules from pH 7 slurry showed the smallest apparent density, and were disintegrated under the smallest applied load. By analysing the relationship between microstructure, apparent density and flow behaviour of the slurries, it was possible to obtain a guideline for preparation of appropriate granules with controlled microstructure and strength. 相似文献
6.
We have directly imaged the formation of a GaAs quantum ring (QR) using droplet epitaxy followed by annealing in arsenic ambient. Based on the atomic force micrograph measurement and the analysis of surface energy, we determine that the formation of self-assembled GaAs QRs is due to the gallium atom's diffusion and crystallization driven by the gradient of surface energy. The phenomenon that GaAs is etched by the gallium droplets is reported and analyzed. It has been demonstrated that the epitaxy layers, such as AlAs and InGaP, can be used as the etching stop layer and hence can be used to control the shape and height of the QRs. 相似文献
7.
V. A. Lashkov E. I. Levashko R. G. Safin 《Journal of Engineering Physics and Thermophysics》2006,79(3):539-546
The heat and mass transfer in the process of drying of high-humidity materials by their depressurization has been investigated.
The results of experimental investigation and mathematical simulation of the indicated process are presented. They allow one
to determine the regularities of this process and predict the quality of the finished product. A technological scheme and
an engineering procedure for calculating the drying of the liquid base of a soap are presented.
__________
Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 79, No. 3, pp. 116–122, May–June, 2006. 相似文献
8.
L. S. Slobodkin N. A. Prudnikov 《Journal of Engineering Physics and Thermophysics》1972,22(6):744-749
A procedure is described by which the method of optical simulation for determining the angular irradiation coefficients in the active zone of various heat-radiation dryers can be evaluated. 相似文献
9.
《Advanced Powder Technology》2020,31(11):4491-4499
Dynamic rheological behaviors of concentrated slurry and wet granules made of graphite, carboxymethyl cellulose, and water have been investigated, because there are few studies on wet granules despite the importance of controlling them. The internal structure and the rheological behaviors of the wet granules were compared with those of the concentrated slurry through the X-ray computed tomography (CT) observation and large amplitude oscillatory shear (LAOS) measurement. At small strain (1%), the concentrated slurry showed larger storage modulus G′ than loss modulus G″, that is, tanδ (=G″/G′) less than 1.0. In contrast, the wet granules indicated larger G″ than G′, that is, tanδ more than 1.0. This rheological behavior of wet granules seems to be attributed to the voids that was suggested to exist in the granular layer. On the other hand, at large strain (100%), the tanδ values of the wet granules were extremely higher than those of the slurry. It appears that this behavior of wet granules is due to the collapse of the granular layer indicated by the high second-harmonic intensities observed in the LAOS measurement. These results elucidated the change of rheological behavior from slurry to wet granules with increasing solid content. 相似文献
10.
11.
A. I. Grigor'ev S. O. Shiryaeva 《Journal of Engineering Physics and Thermophysics》1991,60(4):481-488
A model is proposed for electrical discharge from a water droplet, which explains the experimentally observed formation of a sharp projection at the top of the droplet and emission therefrom of highly dispersed charged droplets and ions.Translated from Inzhenerno-fizicheskii Zhurnal, Vol. 60, No. 4, pp. 632–641, April, 1991. 相似文献
12.
Self-organization of colloidal particles during drying of a droplet: Modeling and experimental study
Katarzyna Jabłczyńska Jakub M. Gac Tomasz R. Sosnowski 《Advanced Powder Technology》2018,29(12):3542-3551
Formation of structurized micro/nanoparticle aggregates in spray drying process is analyzed theoretically and experimentally. Colloids of mono- and bimodal particle size distribution are used as the precursors to demonstrate different patterns of particle self-organization inside the drying droplet. In case of monodisperse primary particles their self-organization in the final aggregate results in either a hollow or a full (packed) spherical structure. For primary particles with bimodal size distribution, either the layered structure of aggregates is formed (with smaller particles forming outer layer and the bigger particles captured inside) or the ordering of bigger particles on the aggregate surface is observed, depending on process parameters. Numerical investigations allow to predict and explain the conditions at which self-assembling of particles within powder aggregates takes place. 相似文献
13.
ZnO powders were synthesized by heating precursors, prepared by the addition of ethylene diamine tetraacetate to an aqueous solution of zinc acetate, at 500?°C in air. A ZnO slurry was prepared by adding distilled water to the synthesized ZnO powder. X-ray diffraction studies confirmed that the ZnO slurry adsorbed CO2 at 25?°C under a CO2 gas flow to produce Zn5(CO3)2(OH)6. The CO2 adsorption ratio of the ZnO slurry was influenced by the amount of added water. When the weight ratio of water/ZnO was 1, the ZnO slurry had the largest CO2 adsorption ratio. Scanning electron microscopy and thermal gravimetry showed that the plate-like Zn5(CO3)2(OH)6 particles thermally decomposed at 300?°C in air leading to a single-phase ZnO powder consisting of nanoparticles with approximately 20?nm in diameter. The specific surface area of the reformed ZnO powder increased to approximately 82?m2/g through the thermal decomposition of Zn5(CO3)2(OH)6. The ZnO slurry was capable of adsorbing CO2 under a CO2 flow at 25?°C and desorbing CO2 under an air flow at 300?°C. The CO2 adsorption ratio of the ZnO slurry reached 80%–90% at 25?°C even after the fifth CO2 adsorption and desorption cycle. 相似文献
14.
A two-dimensional unsteady numerical simulation with a detailed chemical reaction mechanism that considers 158 species and 1804 reactions is applied to pulverized coal combustion in a mixing layer and the soot formation behavior is investigated in detail. The computational conditions and ignition process are the same as those in our previous work (Muto et al., 2017). The results show that the peak of the mass density of the soot is distributed in the region where the gas temperature is higher than the unburned gas temperature of the mixture of volatile matter and air (1300–1400?K) and lower than the flame temperature (2000?K ). This is due to the fact that soot formation from the precursors (C2H2 and C6H6) is enhanced as the gas temperature increases, whereas the quantities of the precursors and the produced soot are reduced due to oxidation at the higher gas temperature condition that exists close to the flame. The peak value of the mass density of the soot is also distributed in the region between the peak values of the gas temperature and the probability density function of the number of coal particles. 相似文献
15.
16.
Ivan G. Marchenko 《Vacuum》2007,81(5):700-707
Computer simulation is explored to study the formation of the niobium film nanostructure by low-temperature deposition. The dependence of dynamical evolution of surface morphology with respect to film thickness is investigated. Calculations of the film density variation at 300 and 800 K are performed. It has been established that the formation of the microcracks elongated along the crystallographic 〈1 0 0〉 direction was the result of surface instabilities during film growth. The internal microstresses arising in the films were evaluated. It has become apparent that the whole complex of phenomena: the porosity formations, the block structure development, the internal microstresses, taking place in the low-temperature deposition, are involved in surface instabilities during niobium film growth. 相似文献
17.
Dmitry Ivanov 《国际生产研究杂志》2018,56(10):3507-3523
Dynamics of structures and processes is one of the underlying challenges in supply chain management, where multiple dimensions of economic efficiency, risk management and sustainability are interconnected. One of the substantiated issues in supply chain dynamics is resilience. Resilience has a number of intersections with supply chain sustainability. This paper aims at analysing disruption propagation in the supply chain with consideration of sustainability factors in order to design resilient supply chain structure in regard to ripple effect mitigation and sustainability increase. Ripple effect in the supply chain occurs if a disruption at a supplier cannot be localised and cascades downstream impacting supply chain performance. This simulation-based study helps to identify what sustainability factors mitigate the ripple effect in the supply chain and what sustainability factors enhance this effect. The results indicate that (i) sustainable single sourcing enhances the ripple effect; (ii) facility fortification at major employers in regions mitigates the ripple effect and enhances sustainability; and (iii) a reduction in storage facilities in the supply chain downstream of a disruption-risky facility increases sustainability but causes the ripple effect. 相似文献
18.
Ice accretion on power lines is a random natural phenomenon and may seriously harm to the safety of power network. However, the mechanism of the freezing process of supercooled water droplet impacting on wires is still not fully understood. In this study, an experimental investigation on the freezing mechanism of the supercooled water droplet impinging on cold metal surfaces was performed. The morphological characters and the dynamics of a single supercooled droplet collide on the cylindrical metal surfaces had been revealed with high-speed photographing. The experimental data for the surfaces of stainless steel, copper and aluminum, on which the supercooled droplets impinging with speeds of 2.3 m s−1 and 4.3 m s−1 had been plotted. The phenomena of instantaneous and non-instantaneous freezing of the supercooled impinging droplet were identified and the conditional boundaries for these two kinds of freezing were found statistically. 相似文献
19.
V. V. Kamenkovich A. S. Zheleznov E. P. Mednikov 《Journal of Engineering Physics and Thermophysics》1967,13(5):399-403
We present the results of an experimental investigation into the kinetics of acoustic drying of silica gel and felt at a frequency of 500 cps; we examine the mechanism of the intensifying effect of acoustic energy on the drying process. 相似文献
20.
A W/O (water-in-oil) emulsion was made from a water–lamp oil mixture with higher water content and a small amount of an additive of amino group-modified silicone oil, and the emulsion could be changed into an ice slurry by cooling with stirring. By using a new continuous ice formation system proposed by one of the authors of this paper, the ice slurry could be formed continuously and stably in an ice formation vessel made of stainless steel. From the experimental results, the conditions were clarified for realizing continuous ice formation for 10 h without ice adhesion to the cooling wall. Moreover, in order to propagate supercooling dissolution of the emulsion effectively and to decrease viscosity in the ice slurry, voltages were applied to the emulsion and ice slurry formed, respectively, and it was clarified that the voltage impression was effective for both. 相似文献