A multi-grid finite-volume method for free-surface flows
Abstract—A depth-averaged subcritical and/or supercritical, steady, free-surface flow numerical model is developed to calculate physical hydraulic flow parameters in open channels. The vertically averaged free-surface flow equations are numerically solved using an explicit finite-volume numerical scheme in integral form. The grid used may be irregular and conforms to the physical boundaries of any problem. A multi-grid algorithm has been developed and has subsequently been applied to accelerate the convergence solution. A grid clustering technique is also applied. The numerical approach is straight forward and the flow boundary conditions are easy enforced. The capabilities of the proposed method are demonstrated by analyzing subcritical flow in an abrupt converging-diverging open channel flume as well calculating supercritical flows in an expansion channel. The computed results are satisfactorily compared with available measurements as well as with other numerical technique results. Very coarse grid gives satisfactory comparison results. The explicit numerical code can be utilized, within the assumptions made about the nature of the flow, for various vertically averaged free-surface flow calculations. Scope is to simulate free-surface flows of practical interest in a straight forward way. It can be extended to channel designs.
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New Formula for Lasik Surgery on Myopic & Hypermetropic Eyes
Abstract— In this paper a new formula is derived for Lasik surgery on Myopic and Hypermetropic eyes. This article has given another formula to calculate the depth of cornea to be ablated, derived mathematically.
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Reducing the Amount of Hard Drive Memory Used For Storing Elements of Abstract Data Types
Abstract— This article proposes, presents and analyzes a new method of saving hard drive memory, used by Abstract Data Types. Abstract Data Types represents an important topic across a variety of application domains, but for several projects the method of memory allocation for the use of Abstract Data Types, presented in the built-in classes of the programming language C#, is not suitable by the reason oflarge possible memory loss. Method, reviewed in this article, can be implemented in other object-oriented programming languages. Sphere of application of represented method encompasses multiple types of Abstract Data Types, such as “list”, “stack”, “queue”, “deq” and several other. Implementation of reviewed solution requires usage of built-in class “array”. Realisated classes become alternative patterns for built-in classes. The ways of usage of a new solutions is similary to the previous ones. Implementation of reviewed solution is done using Microsoft Visual Studio 2017.The results include theoretical conclusions drawn on the basis of practical research.
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New Formula to Calculate the Size of the Corneal Flap for Autologous Ipsilateral Rotational Keratoplasty
Abstract— A new formula for autologous ipsilateral rotational keratoplasty has been designed and verified by surgical procedure on 19 eyes. The formula is found to be successful in all cases. The diameter (D) of the cornea to be rotated is equal to the length of scar from one side of pupillary margin in semidark room, nearest to the scar to the farthest end of the scar (L) nearest to center of pupil, added to the pupillary diameter (Pd) in semidarkness. The direction of rotation of scar is just opposite of radius under consideration and off center by 0.5mm (trephine is put on 0.5mm outside the pupillary margin.
D=L+Pd
Minimum clear cornea required for rotational flap is 4 mm on one side of the pupil. In eyes with eccentric corneal opacities partially involving the pupillary area, using a rotational corneal autograft, can revitalise vision. This procedure does not warrant immunological rejection associated with allografts.
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Value-at-Risk of JCP Stock and Analysis of Calendar Effects
Abstract— This paper presents the value-at-risk (VaR) analysis of J.C. Penney Company Inc. (JCP) stock daily negative log returns between 1993 and 2018. The statistical properties of JCP are thoroughly examined and a series of diagnostic tests are conducted to check the conditions of the time series data over the two decades. The GARCH and EGARCH models with normal distribution and Student’s t-distribution are used to estimate the volatility and VaR of the stock. By analyzing VaR, we show that there is currently a high risk of investing in JCP stock. In addition, this paper examines the calendar effects and seasonality of JCP stock through the fundamental properties of the data as well as the VaR. We compare the performance of the stock in four quarters which further confirms our result that JCP stock is at immense risk at this point in time. These results are valuable for anyone interested in evaluating and forecasting JCP stock. The methodology we use is applicable to any other stock that meets our test conditions and is more accurate and realistic in predicting volatility and VaR than the commonly used standard normal distribution based VaR model.
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Biological Removal of Nitrogen and Phosphorus using Activated Sludge Treatment in Meat Processing Wastewaters
Abstract—The main purpose of this study was to identify the best treatment techniques for wastewater discharged from meat processing. The organic matters in the meat industry wastewater are considerable and complex. To identify the organic component of wastewater we use the parameters to classify it. The most common parameters are the oxygen demand values. We have evaluated the two most common oxygen demand methods, the biochemical oxygen demand and the chemical oxygen demand. In this investigation thorough pretreatment studies were done using the activated sludge treatment.
This treatment was performed at optimal pH using different dosages of activated sludge.
Minimization of wastewaters discharges consist on keeping under continuous control: the quality of wastewaters; their treatment and disposal in an environmentally manner, optimization of processes, maintenance and respective design.