A Coordinated Framework of DG Allocation and Operating Strategy in Distribution System for Configuration Management under Varying Loading Patterns

Abstract

The distributed generation (DG) planning with the varying pattern of the practical load is difficult as it calls for the frequent changes in DG size and system configuration, which is neither feasible nor permissible. Rather such a DG size and a configuration, which can be utilized over a wider load pattern, are more acceptable. This work presents a coordinated approach for DG planning and system reconfiguration. While to operate a particular DG size and the system configuration over a wide range of loading pattern, the configurations are ranked under different probabilistic loading patterns. Based upon the ranking of the new configuration, the energy performance of the coordinated planning is evaluated. Further, the observations from coordinated planning are imposed on coordinated operation using harmony search algorithm (HSA). The proposed approach is tested for single as well as multi-objectives on a 33-node system. A significant improvement in the computational efforts and energy performance of the resulting configuration have been observed where losses have reduced to 81.11 and 53.77?kW with single DG and multi-DG allocation respectively.     

A mathematical model to describe the change in moisture distribution in maize starch during hydrothermal treatment

Instantaneous Controlled Pressure Drop, ' Détente Instantanée Contrôlée ' (DIC) was performed on standard maize starch at residual moisture content (∼12%). Changes in moisture distribution were observed during the treatment and modelled through a phenomenological model based on gravimetric data. The model proposes an exponential variation in the moisture content with processing time at various pressures. The predicted data were found to be in good agreement with experimental data. The values of water activity coefficient ( γ ) obtained from the model decrease, when processing pressure increases; 5.86, 3.71 and 3.36 (dry basis)⁻¹ for 1, 2 and 3 bar, respectively. The mass transfer coefficient decreases, when the pressure increases. Its value ranged from 5.89 × 10⁻⁵ m s⁻¹ for 1 bar down to 0.92 × 10⁻⁵ m s⁻¹ for 2 bar and 0.77 × 10⁻⁵ m s⁻¹ for 3 bar. This coefficient is not only controlled by a simple resistance to the mass transfer, but also by gelatinisation phenomenon that progresses when temperature increases.     

Lensfree color imaging on a nanostructured chip using compressive decoding

We demonstrate subpixel level color imaging capability on a lensfree incoherent on-chip microscopy platform. By using a nanostructured substrate, the incoherent emission from the object plane is modulated to create a unique far-field diffraction pattern corresponding to each point at the object plane. These lensfree diffraction patterns are then sampled in the far-field using a color sensor-array, where the pixels have three different types of color filters at red, green, and blue (RGB) wavelengths. The recorded RGB diffraction patterns (for each point on the structured substrate) form a basis that can be used to rapidly reconstruct any arbitrary multicolor incoherent object distribution at subpixel resolution, using a compressive sampling algorithm. This lensfree computational imaging platform could be quite useful to create a compact fluorescent on-chip microscope that has color imaging capability.     

Fault detection on robot manipulators using artificial neural networks

Nowadays, gas welding applications on vehicle’s parts with robot manipulators have increased in automobile industry. Therefore, the speed of end-effectors of robot manipulator is affected on each joint during the welding process with complex trajectory. For that reason, it is necessary to analyze the noise and vibration of robot’s joints for predicting faults. This paper presents an experimental investigation on a robot manipulator, using neural network for analyzing the vibration condition on joints. Firstly, robot manipulator’s joints are tested with prescribed of trajectory end-effectors for the different joints speeds. Furthermore, noise and vibration of each joint are measured. And then, the related parameters are tested with neural network predictor to predict servicing period. In order to find robust and adaptive neural network structure, two types of neural predictors are employed in this investigation. The results of two approaches improved that an RBNN type can be employed to predict the vibrations on industrial robots.     

编织机及编织工艺的发展

编织是一种重要的预制件成型技术。编织构件具有不分层整体结构、沿编织方向截面可连续变化、复杂结构构件一次成型等特点,具有耐冲击、抗分层、抗蠕变等优异性能。编织物在工程、航空航天、汽车制造等领域广泛应用。本文系统地介绍了编织机、工作原理、各种编织结构及编织结构中具有代表性的单胞结构,讨论了编织机的应用及主要研究方向。     

Two-layered micropolar fluid flow through stenosed artery: Effect of peripheral layer thickness

An unsteady analysis of a two-layered blood flow through a flexible artery under stenotic conditions has been carried out in the present study where the flowing blood is represented by the two-fluid model, consisting of a core region of suspension of all erythrocytes assumed to be Eringen’s micropolar fluid and a plasma layer free from cells of any kind as a Newtonian fluid. The artery has been treated as an elastic (moving wall) cylindrical tube. The equations governing the unsteady flow mechanism subject to pulsatile pressure gradient, has been solved numerically using finite difference scheme by exploiting the appropriate physically realistic prescribed conditions. An extensive quantitative analysis has been performed through numerical computations in order to estimate the effect of different micropolar fluid parameters and the Reynolds number on the flow velocity, the flux, the resistive impedance and the wall shear stress together with their dependencies with time, the input pressure gradient and the severity of the stenosis. The graphical representations of these results do illustrate the flow characteristics of blood under stenotic conditions with proper scientific reasoning and hence validate the applicability of the model under consideration. Special emphasis has duly been made to compare the present theoretical results with the existing ones including experimental results and good agreement between them has been achieved both qualitatively and quantitatively.     

Topotactic transformation of (T-T’) La1.8Nd0.2CuO4: Synthesis,structure, electrical properties and oxygen diffusion pathways simulation

The starting sample T-La_1.8Nd_0.2CuO₄ (SG: Bmab) has been synthesized by the conventional solid-state reaction at 900 °C. The T′-La_1.8Nd_0.2CuO₄ (SG: I4/mmm) sample has been obtained via a topotactic reduction reaction of T-La_1.8Nd_0.2CuO₄ (SG: Bmab) using CaH₂ (as reductor) followed by an oxidation at 400 °C in air. The temperature of the phase transition (T-T′) has been determined using the differential thermal analysis (DTA) and the temperature-dependent powder X-ray diffraction (TDXD). The crystal structures of the title compounds have been refined by using the Rietveld method and confirmed by the means of the charge distribution model (CHARDI). The electrical properties of the title compounds have been studied by impedance complex spectroscopy between 200 °C and 650 °C. This study shows two slopes in the Arrhenius plot with experimental activation energies 1.033 eV and 1.657 eV which correspond to the reduced phase and the T′ phase respectively. The simulation of oxygen diffusion in structures by using the Bond Valence Site Energy (BVSE) method shows three-dimensional pathways of oxygen diffusion. The calculated activation energies of the T′ and T structure are 1.619 and 2.369 eV, respectively.     

Psychological Symptoms Are Greater in Caregivers of Patients on Hemodialysis Than Those of Peritoneal Dialysis

Background: The purpose of this study was to evaluate and compare psychosocial characteristics in caregiving relatives (caregivers) of hemodialysis (HD) and peritoneal dialysis (PD) patients. Methods: Thirty‐three caregivers (17 women, 16 men) of HD patients, 27 caregivers (11 women, 16 men) of PD patients, and a control group of 49 subjects who do not care for family members with chronic illness (23 women, 26 men) are included in this study. The brief symptom inventory (BSI), social disability schedule (SDS), and brief disability questionnaire (BDQ) were used for the psychosocial evaluation. Results: The mean age, men‐to‐women ratios, duration of education, and distribution of marital status did not differ significantly among the three groups. In addition, dialysis duration and distribution of caregiver type were not different between the HD and PD groups. Although the mean global severity index scores of the three groups were similar, somatization and depression scores from BSI subitems were greater in the HD group than the scores of the PD and control groups. Although the mean SDS and BDQ scores were higher in the HD group, the differences did not achieve statistical significance. BSI subitems such as somatization, obsession–compulsion, interpersonal sensitivity, depression, and anxiety were positively correlated among themselves. Hostility and somatization were negatively correlated with age and education, respectively. Nevertheless, somatization was positively correlated with age. Social disability was negatively correlated with duration of education. Conclusion: Somatization and depression are greater in the caregivers of center HD patients compared to PD and control groups. According to the findings of this study, we suggest that caregiving family members of dialysis patients especially on HD also should be evaluated for psychosocial problems and supported as needed. Further studies are needed to explore whether psychosocial parameters of caregivers predict outcomes for caregivers and patients.     

Elastic stability of bi-axially loaded rectangular plates with a single circular hole

The finite-element method has been employed to determine the elastic buckling stresses of a bi-axially loaded perforated rectangular plate with dimensions a and b in the x- and y-directions, respectively. The considered perforation is a single circular hole whose center is located along the longitudinal axis of the plate. The considered plate has simply supported edges in the out-of-plane direction and is subjected to bi-axial uniformly distributed end loads (compressive load σ_x in the x-direction, and compressive or tensile load σ_y in the y-direction). Parameters considered in the study are the plate's aspect ratio a/b, the stress ratio ξ between the applied stresses in the y- and x-directions (ξ=σ_y/σ_x), the circular hole size d and location e_x.The study shows that, in most of the considered cases, the bigger the hole size d, the lesser the plate stability and the lesser the buckling stresses. It also shows that the plate aspect ratios, a/b, between 0.6 and 1.2 should be avoided for plates with large holes and negative ξ, due to the large reduction in the buckling stresses. The hole location should also be selected to be away from the loaded edge of the plate as much as possible (better to have e_x/b>1.0) to increase the buckling stresses and improve stability. The study demonstrates also that the increase in tension in the y-direction in bi-axially loaded plate with large hole (d/b>0.4) reduces its stability. This is in contrary to the expected increase in the stability due to the increase in tension which can be seen clearly in the cases of solid plates and plates with small holes.     

Effect of dynamical chemical etching on the porous structure parameters of superelastic medical Ti–Nb–Zr alloy foam

A dynamical chemical etching technique under pressure is developed and used to fabricate sintered foams based on a superelastic Ti–Nb–Zr alloy. This technique is shown to effectively control the characteristics of a porous structure and to increase the porosity and the permeability of the material.