Growth Rate Of Deposit Research Articles

Experimental study on the scaling law of the heat exchange tube surface in the process of low-temperature single-effect distillation of high-mineralized mine water

High-mineralized mine water, due to its characteristics such as high mineralization degree, will have scaling phenomena on the surface of the heat exchange tube during the desalination treatment process, resulting in a reduction in the water production efficiency of the equipment and affecting the normal operation. To reduce the cost of water production and improve the service life of distillation equipment, this paper independently designs and builds a low-temperature single-effect distillation high-mineralized mine water experimental system to study the influence of operating parameters (temperature, spray density, concentration ratio, and system pressure) on the scaling law on the surface of the heat exchange tube. The distribution and characteristics of scale deposits on the surface of the heat exchange tube are analyzed through the growth rate and microscopic morphology of the scale deposit. The results indicate that the scaling on the surface of the titanium plate is mainly in the needle-like and rod-like morphology of CaCO3 aragonite, and a small amount of CaSO4 and calcite are generated with the increase of temperature. It was found that within the range of spray density from 0.0509 kg/(m·s) to 0.0625 kg/(m·s), concentration ratio from 2.3 to 2.7, and system pressure at 36.3 kPa, it is beneficial to the evaporation heat transfer of the heat exchange tube and the reduction of scaling generation. At the same time, it is found that the scaling of the first row of heat exchange tubes is mainly within the range of circumferential angle from 0 to 100 degrees, and the scaling of the second row and the third row of heat exchange tubes is mainly within the range of circumferential angle from 110 to 170 degrees. The research results of this paper provide support for the design and operation of the low-temperature multi-effect treatment system for mine water in engineering, promote the process of zero discharge of high-mineralized mine water in Xinjiang, China, and improve the resource utilization rate of high-mineralized mine water.

Towards Real-Time Simulation of Two-Dimensional Models for Electrodeposition/Stripping in Lithium-Metal Batteries

Lithium metal anode has been tipped to be the most likely successor of graphite anode in the next generation lithium-based batteries. However, this has not been translated into commercialized lithium metal batteries. While there has been remarkable progress in the experimental design of lithium metal batteries with improved performance1-3, there is limited work on accurate models and robust simulation to study microstructure evolution in lithium metal anode. There also lacks a modeling framework that relates morphological changes with corresponding system-level response in a simultaneous manner. Such a framework can prove to be key in designing lithium metal batteries with long life and high performance. The challenges in developing the same has been discussed in our perspective article4. We also recently reported a simple 1D model to study plating and stripping in lithium metal anode5.In this work, a simple 2D geometry is considered to formulate the model equations and analyze the numerical challenges in (1) spatial discretization, (2) time evolution of the moving boundary to capture deposition/stripping, and (3) optimal discretization scheme in time. A detailed analysis will be presented to compare the standard finite difference/finite element methods and hybrid in-house schemes optimized for the electrochemical model based on coordinate transformation and combination of different numerical schemes. Cycling simulations are performed under different operating conditions considering various cases with surface inhomogeneities, singularity, and initial lithium nuclei.Depending on the geometric, kinetic, and transport parameters, the growth rate and shape of the lithium deposit varies, which in turn affect the cyclability and rate capability of the battery. Our proposed model for predicting metal deposition and stripping in lithium metal batteries brings together the mesoscale and electrochemical models and can pave the path towards achieving tailored morphological characteristics to make lithium metal anodes viable in commercial systems. In this talk, we will present results on computational efficiency and numerical accuracy of different formulations and spatial and temporal discretization methods. We will also discuss the real-time simulation of the proposed model for deriving optimal charging profiles. Acknowledgments This research was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the US Department of Energy (DoE) through the Advanced Battery Materials Research Program (Battery500 Consortium). References K. N. Wood, E. Kazyak, A. F. Chadwick, K. H. Chen, J. G. Zhang, K. Thornton, and N. P. Dasgupta, ACS Cent. Sci., 2, 790-801 (2016).J. Liu, Z. Bao, Y. Cui, E. Dufek, J. B. Goodenough, P. Khalifah, Q. Li, B. Liaw, P. Liu, A. Manthiram, Y. S. Meng, V. R. Subramanian, M. F. Toney, V. V. Viswanathan, M. S. Whittingham, J. Xiao, W. Xu, J. Yang, X. Yang, and J. Zhang, Nat. Nanotechnol., 14 180-186 (2019).A. Pei, G. Zheng, F. Shi, Y. Li, and Y. Cui., Nano Lett., 17(2), 1132-1139 (2017).K. Shah, A. Subramaniam, L. Mishra, T. Jang, M. Z. Bazant, R. D. Braatz, and V. R. Subramanian, J. Electrochem. Soc., 167, 133501 (2020).M. Uppaluri, A. Subramaniam, L. Mishra, V. Viswanathan, and V. R. Subramanian, J. Electrochem. Soc., 167, 160547 (2020).T. Jang, L. Mishra, K. Shah, P. Mittal, A. Subramaniam, M. P. Gururajan, S. A. Roberts, and V. R. Subramanian, 2021 ECS Meet. Abstr. (239th Meeting, in progress)

Electronic Banking and Growth of Deposit Money Banks Operations: Nigeria Experience

The study examined the Nigeria experience of the influence of electronic banking on the growth of deposit money banks in Nigeria. The research design used for the study was the expost-facto research design. The data used in this study were obtained from the annual reports and statements of accounts of Nigeria deposit insurance corporation. CBN annual report and account, CBN statistical bulletin; various online journals and literature. In order to achieve the objective of this study, a linear regression was adopted on both functional and statistical models. The study found that internet banking has a negative impact on growth rate of total deposit of deposit money banks in Nigeria with a regression coefficient of -10.09143. Automated Teller Machine (ATM) operation has a positive impact on asset growth of deposit money banks in Nigeria with a regression coefficient 37.13510 and Point of Sale (POS) transaction has a positive impact on asset growth of deposit money banks in Nigeria with a regression coefficient 1.334829. The study therefore recommends among others that due to the insignificant relationship that exists between internet banking and deposit growth banks that are yet to fully adopt internet banking should do so as a matter of urgency if they must grow, remain relevant, competitive and profitable. Banks that seek to improve their deposit growth performance and offer numerous products / services in an effective, efficient and cost effective manner. There should be increased awareness creation about the use of smart cards for banking operations and banks should also improve the number of services that ATM can offer the banking public. The Central Bank of Nigeria should ensure that guidelines with respect to POS transactions are properly adhered to.

Has Internet Finance Decreased the Profitability of Commercial Banks?: Evidence from China

ABSTRACT This paper explores the popularity of internet finance and its potential shocks to the business of traditional commercial banking in China. Using data on 200 commercial banks in China during the period 2011 to 2016, this paper investigates whether internet finance, measured by P2P (peer-to-peer lending) lending and third-party payment, has a negative impact on the profitability of commercial banks. It concludes that P2P lending and third-party payment has significant negative influence on the profitability of loans and deposits at China’s commercial banks. By intensifying competition, the development of internet finance has decreased the interest income of loans, increased the interest cost of deposits, lowered the growth rate of loans and deposit, and brought about more risk. City and rural banks and unlisted banks are more vulnerable to internet finance than large government-owned and joint-stock banks.

Experimental study on ash deposition of Zhundong coal in oxy-fuel combustion

To facilitate the large-scale utilization of high-alkali and -alkaline earth metals (AAEMs) coals in power generation, the ash deposition behaviors of a typical Zhundong coal in oxy-fuel combustion were experimentally investigated using a drop tube furnace. A wall-temperature-controlled ash deposition probe by which the bulk gas temperature could be measured simultaneously was designed and employed in the experiments. The deposition tendencies, ash morphologies, chemical compositions of deposited ash particles were studied respectively under various oxygen concentrations, bulk gas temperatures, probe surface temperatures and probe exposure times. The experimental results revealed that the oxygen concentration had a significant influence on the deposition behavior during oxy-fuel combustion of high-alkali coal. Compared with air case, more fine ash particles were generated during the combustion of Zhundong coal in 21% O2/79% CO2 atmosphere but the deposition tendency was weaker. However, a higher oxygen concentration could aggravate the tendency of ash deposition. The high contents of iron (Fe), calcium (Ca), sulfur (S), and sodium (Na) in Zhundong coal could result in the generations of low-melting point compounds. Calcium in flue gas existed as CaO and was captured prior to SO3 by the probe surface during the ash deposition process. At the initial 30 min of the ash deposition process, the dark spherical fine ash particles rich in Fe, Na, oxygen (O), and S were largely produced, while in the range of 60–90 min the light spherical fine ash particles with high contents of Ca, barium (Ba), O, and S were generated on the other hand. The deposition mechanisms at different stages were different and the melted CaO (BaO)/CaSO4 (BaSO4) would give rise to a fast growth rate of ash deposit.

Analysis of Growth Rate of Deposits and Advance: A Study of Selected Banks in India

Banks play a fundamental role in the growth of the economy of the country. A bank is an institution engaged in accepting deposits and granting loans. One of the important roles of the banking industry is to channelize the deposit money for the purpose of the lending activity. A pattern of deposit and lending is one of the important factors which affect the profitability and risk management of a bank. The objective of the research study is to analyze the difference between the growth rate of deposits and advances of selected banks. Two banks from each sector (Public, Private and Foreign Sector) are selected for the study and the research period is from 2011 to 2015. The Kruskal-Wallis W test was used for the purpose of hypothesis testing. The result shows that W-Kruskal-Wallis test value is greater than table value, it means that there is significant difference between the growth rate of deposit and advance of selected banks under the study.

Counterintuitive Effects of the Oil Flow Rate on Wax Deposition

The experimental trend of a reduced deposit with an increasing flow rate has been observed in a series of wax studies. Despite the fact that many previous studies intuitively attribute the reason to the “shear removal”, the role of heat and mass transfer was frequently overlooked as the true explanation. In the current study, the Michigan Wax Predictor (MWP) was applied to elucidate this trend by analyzing the growth rate of the wax deposit in a series of flowloop experiments from first principles. The model was able to predict the experimentally observed decrease in deposit thickness with an increasing oil flow rate without any adjustable parameters. It was found that three effects exist to affect wax deposition when the oil flow rate is changed, and each one can either increase or decrease the growth rate of the deposit. These effects focus on the heat- and mass-transfer phenomena at the oil–deposit interface. In addition, this study also revealed that the dynamics of the competition between all of thes...

Separation of fatty acids from binary melts using physical vapour deposition (PVD)

BACKGROUND: The use of fatty acid mixtures, natural biochemical compounds, will be extended to various chemical industries for the production of a wide variety of products, and various mixtures of fatty acids are necessary for production. Separation of a binary fatty acid mixture of lauric acid and myristic acid using physical vapour deposition (PVD) on a cold quartz crystal resonator is examined. The extremely small amount of deposits can be measured with the quartz crystal resonator. The vapour phase is prepared by vaporizing a calculated composition of melt according to the vapour-liquid equilibrium (VLE). RESULTS: The composition of lauric acid in the melt and the melt temperature were utilized as operating variables in the PVD. The growth rate of deposit increases when melt temperature and the composition of lauric acid in the melt are increased. The composition of lauric acid in the deposit is significantly lower than that of the melt of 19% lauric acid, but the composition of lauric acid in the deposit is much higher than that of the melts of 50% and 75% lauric acid. CONCLUSION: The distribution coefficient of lauric acid between solid and vapour phases can be correlated as a function of the growth rate of deposit. The possibility of separation of fatty acid mixtures by PVD is suggested experimentally and theoretically. Copyright © 2008 Society of Chemical Industry

PVD of fatty acids on a cold quartz crystal sensor

A fatty acid mixture of lauric acid and myristic acid was deposited on a cold quartz crystal sensor from the binary vapor phase of the mixture by physical vapor deposition (PVD). The cold quartz crystal sensor could detect a small amount of deposit in real time, and provided the growth rate of the thin solid deposit by the PVD. The composition of lauric acid in vapor phase was fixed at a mole fraction of about 0.5 by controlling the composition of lauric acid in melt phase computed from the vapor–liquid equilibrium (VLE). The growth rate of solid phase in the PVD increased with the elevation of the melt temperature, because the vapor pressure of the melt raised by the temperature elevation was the driving force of the PVD. The composition of lauric acid in the solid phase was considerably lower than that in the vapor, and it was increased as the growth rate in the solid phase rose. The distribution coefficient of lauric acid between solid and vapor phases was much less than that between solid and melt phases. We compared the separation capacity in melt crystallization with that in the PVD using the effective distribution coefficient, and found that the PVD had higher separation capacity.

Growth behavior of copper metalorganic chemical vapor deposition using the (hfac)Cu(VTMOS) precursor on titanium nitride substrates

Metalorganic chemical vapor deposition of copper using the thermally stable (hfac)Cu(VTMOS) [C10H13O5CuF6Si: 1,1,1,5,5,5-hexafluoro-2,4 pentadionato(vinyltrimethoxysilane) copper (I)] precursor has been carried out on TiN substrates prepared by physical vapor deposition (PVD) and rapid thermal processing (RTP). The apparent activation energies over substrate temperatures ranging from 160 to 220 °C were about 7.5 kcal/mol on the PVD-TiN and 9.7 kcal/mol on the RTP-TiN. The higher growth rate of the copper deposit on the RTP-TiN could be ascribed to the increase in nucleation sites and the higher electron catalytic reactivity, resulting in enhancement of copper nucleation density in the initial stages of film growth. The copper deposits revealed polycrystalline phases with a preferred orientation of (111), and impurities within the films were below the detection limit of Auger electron spectroscopy. As substrate temperature increased, the copper films on the PVD-TiN developed as a columnar structure according to the Volmer–Weber growth mode, and on the RTP-TiN a nearly equiaxed structure was formed presumably by Stranski–Krastanov grain growth. The electrical resistivity of the deposits on the PVD-TiN and the RTP-TiN was in the range 2.8–5.4 μΩ cm for 1500–3100 Å film thicknesses and 4.4–6.2 μΩ cm for 2300–4300 Å film thicknesses, respectively. With increasing film thickness, the electrical resistivity of the copper layers linearly increased on the PVD-TiN, while it gradually decreased on the RTP-TiN. Consequently, the variations in the electrical resistivity of the deposits could be explained by changes in microstructures of the copper films, due to different growth behavior of copper on the two types of substrates.

The effect of buoyancy on the formation of a solid deposit freezing onto a vertical surface

The growth rate and spatial distribution of a solid deposit freezing onto a vertical surface is analytically predicted for the case in which there is heat transfer at the moving phase interface due to natural convection in the fluid. It is shown that under certain conditions the problem may be treated as involving a transient, one-dimensional conduction process and a quasi-steady two-dimensional convection process which are coupled through the requirements of conservation of mass and energy at the phase interface. An approximate solution is obtained using integral techniques and results are in agreement with those limiting cases for which exact solutions are known.

Tungsten shadow casting for electron microscopical specimens

A method is described for the controlled sublimation of tungsten wire at a temperature just below the melting point. The variance in light reflectivity with the thickness of the tungsten film condensed on a flat polished glass surface provides a sensitive indicator for the accurate control and maintenance of the filament temperature during evaporation and thus for the controlled growth rate of the deposit. This latter is tungsten and not a tungsten oxide, as has been verified by X-ray and transmission electron diffraction analyses. As many vacuum evaporators are equipped with an optical film thickness measuring device, it is possible to use them, slightly modified, for the controlled evaporation of tungsten.

Effect of Growth Rate on Stacking-Fault Density in Epitaxial Silicon Layers

The growth rate of an epitaxial silicon deposit affects the stacking-fault density of the deposited layer in a linear manner over the deposition range of 0.1 to 1.0 μ/min. The stacking-fault density is also inversely related to the substrate dislocation density for dislocation densities up to 5×103 cm−2. The conditions for the formation of stacking faults, as described by various authors to date, seem sufficient but not necessary for fault formation. The present work supports a vacancy condensation mechanism by which the low stacking-fault energy of the material creates a natural condensation of vacancies into stacking faults.