scispace - formally typeset
Search or ask a question
Author

Maria A. Barrufet

Bio: Maria A. Barrufet is an academic researcher from Texas A&M University. The author has contributed to research in topics: Oil shale & Capillary pressure. The author has an hindex of 25, co-authored 133 publications receiving 3047 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: A simple cathode erosion model for the electrical discharge machining (EDM) process is presented in this article, where a constant fraction of the total power supplied to the gap is transferred to the cathode over a wide range of currents.
Abstract: A simple cathode erosion model for the electrical discharge machining (EDM) process is presented. This point heat‐source model differs from previous conduction models in that it accepts power rather than temperature as the boundary condition at the plasma/cathode interface. Optimum pulse times are predicted to within an average of 16% over a two‐decade range after the model is tuned to a single experimental point. A constant fraction of the total power supplied to the gap is transferred to the cathode over a wide range of currents. A universal, dimensionless model is then presented which identifies the key parameters of optimum pulse time factor (g) and erodibility (j) in terms of the thermophysical properties of the cathode material. Compton’s original energy balance for gas discharges is amended for EDM conditions. Here it is believed that the high density of the liquid dielectric causes plasmas of higher energy intensity and pressure than those for gas discharges. These differences of macroscopic diele...

559 citations

Journal ArticleDOI
TL;DR: In this paper, an erosion model for the anode material is presented, which is capable of showing, via determined migrating melt fronts, the rapid melting of the anodic material as well as the subsequent resolidification of the material foation from plasma dynamics modeling.
Abstract: As a second in a series of theoretical models for the electrical discharge machining (EDM) process, an erosion model for the anode material is presented As with our point heat‐source model in the previous article, the present model also accepts power rather than temperature as the boundary condition at the plasma/anode interface A constant fraction of the total power supplied to the gap is transferred to the anode The power supplied is assumed to produce a Gaussian‐distributed heat flux on the surface of the anode material Furthermore, the area upon which the flux is incident is assumed to grow with time The model is capable of showing, via the determined migrating melt fronts, the rapid melting of the anodic material as well as the subsequent resolidification of the material foation from plasma dynamics modeling could improve substantially our results

394 citations

Journal ArticleDOI
TL;DR: In this article, a variable mass, cylindrical plasma model (VMCPM) is developed for sparks created by electrical discharge in a liquid media, which consists of three differential equations: fluid dynamics, an energy balance, and the radiation equation combined with a plasma equation of state.
Abstract: A variable mass, cylindrical plasma model (VMCPM) is developed for sparks created by electrical discharge in a liquid media. The model consist of three differential equations—one each from fluid dynamics, an energy balance, and the radiation equation—combined with a plasma equation of state. A thermophysical property subroutine allows realistic estimation of plasma enthalpy, mass density, and particle fractions by inclusion of the heats of dissociation and ionization for a plasma created from deionized water. Problems with the zero‐time boundary conditions are overcome by an electron balance procedure. Numerical solution of the model provides plasma radius, temperature, pressure, and mass as a function of pulse time for fixed current, electrode gap, and power fraction remaining in the plasma. Moderately high temperatures (≳5000 K) and pressures (≳4 bar) persist in the sparks even after long pulse times (to ∼500 μs). Quantitative proof that superheating is the dominant mechanism for electrical discharge ma...

297 citations

Book
30 Jun 1999
TL;DR: In this article, the authors present a theoretical analysis of deep-fat and continuous-fryer control systems for low-fat tortilla chips, and a detailed analysis of Fried Product Quality.
Abstract: Introduction. Fried Product Processing and Characteristics. Frying Oil Characteristics. Fried Product Quality. Introductory Analysis of Frying Systems. Theory and Simulation of Frying. Oil Absorption in Fried Foods. Deep-Fat Frying Systems. Continuous Fryer Control Systems. Low-Fat Tortilla Chips. Packaging Fried Foods. Index.

225 citations

Journal ArticleDOI
TL;DR: In this paper, the mechanism of oil absorption of tortilla chips during cooling was analyzed using capillary pressure theory, and the experimental and theoretical results obtained with this mechanistic model agreed well.

106 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: Major research efforts in the future could focus on the optimization of current technologies and use of combined physico-chemical and/or biological treatment of produced water in order to comply with reuse and discharge limits.

1,862 citations

Journal ArticleDOI
TL;DR: In this article, the authors proposed a more efficient algorithm to achieve the results that includes Gibbs minimization when we know the number of phases, using the orthogonal derivatives, the tangent plane equation and mass balances, which is easier and faster than finding tangents or areas and appears to converge as fast as the K-value method.

1,145 citations

Journal ArticleDOI
TL;DR: Antioxidant decreases the frying oil oxidation, but the effectiveness of antioxidant decreases with high frying temperature, and lignan compounds in sesame oil are effective antioxidants in deep-fat frying.
Abstract: Deep-fat frying produces desirable or undesirable flavor compounds and changes the flavor stability and quality of the oil by hydrolysis, oxidation, and polymerization. Tocopherols, essential amino acids, and fatty acids in foods are degraded during deep-fat frying. The reactions in deep-fat frying depend on factors such as replenishment of fresh oil, frying conditions, original quality of frying oil, food materials, type of fryer, antioxidants, and oxygen concentration. High frying temperature, the number of fryings, the contents of free fatty acids, polyvalent metals, and unsaturated fatty acids of oil decrease the oxidative stability and flavor quality of oil. Antioxidant decreases the frying oil oxidation, but the effectiveness of antioxidant decreases with high frying temperature. Lignan compounds in sesame oil are effective antioxidants in deep-fat frying.

965 citations

Journal ArticleDOI
TL;DR: In this paper, the authors highlight the recent development of advanced membrane technology such as surface modification, addition of inorganic particles in polymer membrane and the development of ceramic membranes and discuss the effect of operating parameters on the membrane performance.

933 citations

Journal ArticleDOI
TL;DR: In this paper, the authors reviewed the research trends in electrical discharge machining on ultrasonic vibration, dry EDM machining with powder additives, EDM in water and modeling technique in predicting EDM performances.
Abstract: Electrical discharge machining (EDM) is one of the earliest non-traditional machining processes. EDM process is based on thermoelectric energy between the work piece and an electrode. A pulse discharge occurs in a small gap between the work piece and the electrode and removes the unwanted material from the parent metal through melting and vaporising. The electrode and the work piece must have electrical conductivity in order to generate the spark. There are various types of products which can be produced using EDM such as dies and moulds. Parts of aerospace, automotive industry and surgical components can be finished by EDM. This paper reviews the research trends in EDM on ultrasonic vibration, dry EDM machining, EDM with powder additives, EDM in water and modeling technique in predicting EDM performances.

785 citations