A Fuzzy Expert System for Evaluation of Demand-Side Management Alternatives

It is believed that the onset of true competition in the electric power industry may result in the demise of demand-side management (DSM) as it is known today, which is primarily a means of optimizing a utility's load curve. If DSM is to survive, utilities will need to evaluate the large number of possible options more efficiently and effectively than ever before. To reach this goal, the subjective portion of the evaluation process has been formulated into a fuzzy expert system, yielding faster, more efficient, and consistent results. This paper outlines the development of FEDSM, a Fuzzy Expert system designed to evaluate D emand-Side Management alternatives. FEDSM is a user-friendly, visual basic, and spreadsheet-based evaluation tool which allows the user to develop a flexible expert system. FEDSM is tested and evaluated on actual DSM data collected by a public utility in Nebraska, generating promising results.     

CALCULATING PSEUDO-STEADY-STATE HORIZONTAL OIL WELL PRODUCTIVITY IN RECTANGULAR DRAINAGE AREAS USING A SIMPLE METHOD

To determine the economical feasibility of drilling a horizontal well, engineers need reliable methods to estimate its productivity. In this work, a simple-to-use method is developed to rapidly estimate a pseudo-steady-state horizontal well's productivity. Estimations are found to be in excellent agreement with the reliable data in the literature, with average absolute deviation being less than 1%. The tool developed in this study can be of immense practical value for petroleum engineers to make a quick check on a pseudo-steady-state horizontal well's productivity at various conditions without opting for any field trials. The predictive tool is simple and straightforward, and it can be readily implemented in a standard spreadsheet program. The prime application of the method is as a quick-and-easy evaluation tool in conceptual development and scoping studies where horizontal wells are being considered. The method may also serve as a benchmark in numerical reservoir simulation studies.     

Online measurement of particle size distribution during crystallization using ultrasonic spectroscopy

Particle growth during crystallization of paracetamol was monitored on-line using a new modified method based on ultrasonic spectroscopy. The model was earlier developed and tested with inert particles systems and accounts for low angle scattering and probe geometry. A graphic user interface was developed and integrated with the model based deconvolution algorithm for real-time data acquisition, analysis and display of results. The crystal growth and changes in size distribution were measured during the crystallization of paracetamol from paracetamol–isopropanol–water solution. A simplified pre-calibration procedure using acoustic velocity to estimate solution properties was established. The model based particle size distribution showed good agreement with offline measurements using laser diffraction analysis of a sample retrieved from the crystallizer.     

Effect of different precooking methods on chemical composition and lipid damage of silver carp (Hypophthalmichthys molitrix) muscle

The influence of three precooking methods (steaming, oven‐baking and microwave‐cooking) on the chemical composition and lipid quality of silver carp fillets was evaluated. The changes in protein, fat and moisture were found to be significant for all the treatments (P ≤ 0.05). The iron content in the samples subjected to steam‐cooking increased; however, the other precooking methods did not change the mineral contents (P ≥ 0.05). The free fatty acid content of the fillets did not change by the different precooking methods, while thiobarbituric acid (TBA) values increased for oven‐ and microwave‐cooked fillets and remained constant in the steam‐cooked samples. Conjugated diene and browning colour formation levels significantly increased in the oven‐baked fillets. Oven‐baking and microwave‐cooking marginally affected the fatty acid composition of the silver carp. On comparing the raw and precooked fillets, steam‐cooking was found to be the best precooking method on retaining nutritional constituents.     

Hybrid connectionist model determines CO_2–oil swelling factor

In-depth understanding of interactions between crude oil and CO_2 provides insight into the CO_2-based enhanced oil recovery(EOR) process design and simulation. When CO_2 contacts crude oil, the dissolution process takes place. This phenomenon results in the oil swelling, which depends on the temperature, pressure, and composition of the oil. The residual oil saturation in a CO_2-based EOR process is inversely proportional to the oil swelling factor. Hence, it is important to estimate this influential parameter with high precision. The current study suggests the predictive model based on the least-squares support vector machine(LS-SVM) to calculate the CO_2–oil swelling factor. A genetic algorithm is used to optimize hyperparameters(у and б~2) of the LS-SVM model. This model showed a high coefficient of determination(R~2= 0.9953) and a low value for the mean-squared error(MSE = 0.0003) based on the available experimental data while estimating the CO_2–oil swelling factor. It was found that LS-SVM is a straightforward and accurate method to determine the CO_2–oil swelling factor with negligible uncertainty. This method can be incorporated in commercial reservoir simulators to include the effect of the CO_2–oil swelling factor when adequate experimental data are not available.     

Dynamic modeling of continuous evaporative cooling KCl-NaCl crystallizers

Previous work on the modeling of potash crystallizers has been mainly limited to the estimation of crystal size distribution (CSD) in the presence of only one solid component (KCl). In the present study, an attempt has been made to develop a model that incorporates NaCl as a second component that may co-precipitate along with KCl under certain operating conditions. Addition of water to prevent co-saturation or as a means of internal fines dissolution is also taken into consideration. External fines dissolution using a heat exchanger is incorporated in the model. In addition to the CSD, the model is able to predict crystal impurity resulting from co-saturation with NaCl. The predictive capability of the model is tested using limited dynamic experimental data obtained from a 1 m³ pilot plant continuous evaporative crystallizer and the steady-state experimental data from a two-stage evaporative Swenson DTB industrial potash crystallizer circuit. In both cases, a good agreement between the model predictions and the experimental data was noticed.     

Investigation of styrene/1‐hexene copolymerization by homogeneous and heterogeneous bisindenyl ethane zirconium dichloride catalyst system

Homogeneous copolymerization of styrene and 1‐hexene was carried out in toluene at room temperature using bisindenyl ethane zirconium dichloride/methylaluminoxane (MAO). The supported catalyst was prepared with immobilization of Et(Ind)₂ZrCl₂/MAO on silica (calcinated at 500°C) with premixed method. Heterogeneous copolymerization of styrene/1‐hexene with different mole ratios was carried out in the presence of supported catalyst system. The copolymers obtained from homogeneous and heterogeneous catalyst system were characterized by ¹H NMR and ¹³C NMR. Composition of the resulting copolymers was determined by ¹H NMR data. Analysis of ¹³C NMR spectra of obtained copolymers by homogeneous and heterogeneous catalyst systems present isotactic olefin‐enriched copolymers. Molecular weight and thermal behavior of resulting copolymers was investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4008–4014, 2007