Types Of DG Research Articles

Selection of Sensitive Buses using the Firefly Algorithm for Optimal Multiple Types of Distributed Generations Allocation

Power loss is one aspect of an electric power system performance indicator. Loss of power can have an impact on poor voltage performance at the receiving end. DG integration in the network has become one of the more powerful methods. To get the maximum benefit from synchronizing the system with DG, it is necessary to ascertain the size, location, and type of DG. This study aims to determine the capacity and location of DG connections for DG type I and type II. To address the aim of this paper, a metaheuristic solution based on a firefly algorithm is used. FA can cover up the lack of metaheuristic algorithms that require a long computational time. To ensure that the load bus location solution is selected as the best DG connection location, the input of the load bus candidate has been filtered based on stability sensitivity. The proposed method is tested on IEEE 30 buses. The optimization results show a decrease in power loss and an increase in bus voltage, which affects an increase in system stability by integrating three DG units. FA validation of the evolution-based algorithm shows a significant reduction in computational time.

ИССЛЕДОВАНИЕ ВИБРАЦИИ ГАЗОПЕРЕКАЧИВАЮЩИХ АГРЕГАТОВ С СУДОВЫМ ГАЗОТУРБИННЫМ ПРИВОДОМ

The operation reliability of power units is defined to a great extent by their vibration state, where a basic source of exciting effects is shafting.
 For the thorough analysis of a vibration state of turbine units the special vibroacoustic investigations are necessary in the course of which there are must be defined: characters of vibration processes, increased vibration reasons, phenomena promoting the intensification of vibration processes in power units.
 With the purpose of systematization and accu-mulation of such materials there were carried out in-vestigations of vibro-activity of gas-compressor units (GCU) with marine gas turbine drive and working at compressor plants of gas-main pipelines. The plant of GPA-16MG90 type with the power of 16MWt was an object of investigations, where a marine convertible DG-90 manufactured by production company “Zarya” was used as a drive for a natural gas super-charger of 370-18-1 NZL type. 
 The results of measuring indicate the necessity for taking measures to eliminate an increase vibration of a supporting – thrust bearing of the supercharger and gas turbine engine of DG type.

A parallel Runge–Kutta discontinuous Galerkin solver for rarefied gas flows based on 2D Boltzmann kinetic equations

The high-order Runge–Kutta Discontinuous Galerkin (RKDG) method is applied to solve the 2D Boltzmann kinetic equations. A conservative DG type discretization of the non-linear collision relaxation term is formulated for both the Bhatnagar–Gross–Krook and the ellipsoidal statistical kinetic models. Verification is carried out for a steady and an unsteady oscillatory 1D Couette flows, a 2D conduction problem as well as for a 2D long microchannel flow by comparison with the DSMC and analytical solutions. The computational performance of the RKDG method is compared with a widely used second-order finite volume method. The RKDG method has up to 3rd-order spatial accuracy and up to 4th-order time accuracy and is more efficient than the finite volume approach. The parallelization by domain decomposition in physical space is implemented and parallel performance is evaluated. It is shown that 2nd order RKDG is over 15 times faster than the 2nd-order FVM method for the Couette flow test case. The high-order RKDG method is especially attractive for solution of low-speed and unsteady rarefied flows.

Multi types DG expansion dynamic planning in distribution system under stochastic conditions using Covariance Matrix Adaptation Evolutionary Strategy and Monte-Carlo simulation

This paper presents a dynamic DG planning problem considering uncertainties related to the intermittent nature of the DG technologies such as wind turbines and solar units in addition to the stochastic economic conditions. The stochastic economic situation includes the uncertainties related to the fuel and electricity price of each year. The Monte Carlo simulation is used to generate the possible scenarios of uncertain situations and the produced scenarios are reduced through backward reduction program. The aim of this paper is to maximize the revenue of the distribution system through the benefit cost analysis alongside the encouraging and punishment functions. In order to close to reality, the different growth rates for the planning period are selected. In this paper the Covariance Matrix Adaptation Evolutionary Strategy is introduced and is used to find the best planning scheme of the DG units. The different DG types are considered in the planning problem. The main assumption of this paper is that the DISCO is the owner of the distribution system and the DG units. The proposed method is tested on a 9 bus test distribution system and the results are compared with the known genetic algorithm and PSO methods to show the applicability of the CMAES method in this problem.

Histological phenotype is correlated with the wall-invasion pattern of gallbladder adenocarcinoma.

Gallbladder carcinoma (GBC) is one of the most aggressive malignancies, and frequently shows vascular invasion and lymph node metastasis. Our previous study has classified the wall-invasion pattern of GBC into two groups, i.e., infiltrative growth type (IG type) and destructive growth type (DG type). The DG type was significantly associated with poor clinical outcome. In this study, we analyzed the relationship between the wall-invasion pattern and the histological phenotype of GBC, using 61 surgically-resected primary gallbladder adenocarcinomas. Histologically, the 61 cases were classified into the biliary (44 cases, 72.1%), gastric foveolar (13 cases, 21.3%), and intestinal (4 cases, 6.6%) types. Biliary type frequently exhibited MUC1, but less frequently showed MUC2, MUC5AC, and MUC6. The biliary type and MUC1 expression were significantly correlated with DG type wall-invasion pattern (P = 0.020 and P < 0.001, respectively). In conclusion, histological phenotype and mucin expression were thought to be indicators of aggressiveness of GBC.

Local flux conservative numerical methods for the second order elliptic equations

A discontinuous Galerkin type nonconforming element method and a local flux matching nonconforming element method for the second order elliptic boundary value problems are presented. Both of these methods enjoy the local flux conservation property. The local flux matching method finds a numerical solution in the same solution space of the DG type nonconforming element method, but it achieves much faster iterative convergence speed by embedding continuity requirement in the approximation functions rather than using constraint equations that are used in the DG type nonconforming element method. The merits of the proposed local flux matching method are as follows: the formulation of the method is simple and the solution satisfies local flux conservation property. Moreover, it can be easily applied to general elliptic equations.

Multiple Distributed Generator Placement in Primary Distribution Networks for Loss Reduction

This paper investigates the problem of multiple distributed generator (DG units) placement to achieve a high loss reduction in large-scale primary distribution networks. An improved analytical (IA) method is proposed in this paper. This method is based on IA expressions to calculate the optimal size of four different DG types and a methodology to identify the best location for DG allocation. A technique to get the optimal power factor is presented for DG capable of delivering real and reactive power. Moreover, loss sensitivity factor (LSF) and exhaustive load flow (ELF) methods are also introduced. IA method was tested and validated on three distribution test systems with varying sizes and complexity. Results show that IA method is effective as compared with LSF and ELF solutions. Some interesting results are also discussed in this paper.

DG型电子加速器自校正扫描系统的研制

DG型电子加速器自校正扫描系统的研制

Clinical significance of wall invasion pattern of subserosa-invasive gallbladder carcinoma

We have previously classified wall invasion patterns of gallbladder carcinoma (GBC) cases into two groups, i.e., the infiltrative growth type (IG type) and destructive growth type (DG type). The DG type was significantly associated with poor differentiation, aggressive infiltration and decreased postoperative survival in terms of its histological differentiation, lymphatic invasion, venous invasion, lymph node status, neural invasion and mode of subserosal infiltration. In the present study, we analyzed 42 surgically-resected subserosal invasive gallbladder adenocarcinomas, invading the perimuscular connective tissue (pT2). The cumulative 5-year survival rate in the series was 48.7%. Lymphatic invasion (p=0.021), venous invasion (p=0.020), mode of subserosal infiltration (p<0.001), histological differentiation (p=0.030) and biliary infiltration (p=0.007) were noted, respectively, at a significantly higher incidence in more aggressive infiltration or poor differentiation in the DG type. The cumulative 5-year survival rate of curative resection cases was lower in patients with the DG type than in those with the IG type (68.9 versus 20.2%, respectively, p=0.006, log-rank test). On Cox’s proportional hazard regression modeling, the low degree of venous/perineural invasion and IG type of wall invasion pattern were associated with a significant improvement in overall survival. Our data suggest that the wall invasion pattern is an independent predictor of survival in subserosal invasive GBC. Regarding the clinical application of our concept, on the classification of patients with subserosal invasive GBC based on a combination of the wall invasion pattern and lymph node status, the overall survival rate in patients with the DG type and/or N2 metastasis (n=21) was lower than in patients with the IG type and N0, 1 metastasis (n=21) (p=0.0023, log-rank test). The wall invasion pattern could contribute to decision-making concerning curative resection for subserosal invasive GBC.

Stromal laminin-5γ2 chain expression is associated with the wall-invasion pattern of gallbladder adenocarcinoma

Our previous study demonstrated that the pT2 and pT3-4 gallbladder carcinomas can be classified into two groups, i.e. infiltrative growth type (IG type) and destructive growth type (DG type) and that the DG type is associated with poor differentiation, aggressive infiltration, and decreased postoperative survival. The present study focused on the clinicopathologic significance of laminin-5gamma2 chain expression as an indicator of local aggressiveness and Ki-67 labeling index (Ki-67 LI) as an indicator of the cell proliferation activity of gallbladder carcinoma. Ki-67 LI was higher in the DG type (26.3%) than in the IG type (21.4%), and the rate of high-grade cell proliferation cases (Ki-67 LI > or = 30%) was high in the DG type (P = 0.012). Gallbladder carcinoma cases with high Ki-67 LI were significantly associated with poorly differentiation (P = 0.089) and distant lymph node metastasis (P = 0.079). Laminin-5gamma2 expression patterns of gallbladder carcinoma were divided into two distinct types, extracellular staining and cytoplasmic staining. The extracellular staining was subclassified into two groups, basement membrane staining and stromal staining. In the basement membrane staining, laminin-5gamma2 was present in the basement membranes surrounding neoplastic glandular structures. The basement membrane staining of laminin-5gamma2 was more frequent in the IG type (40%) than in the DG type (12.9%) (P = 0.025). The stromal staining was more frequent in the DG type. Furthermore, the stroma-positive group was more closely associated with decreased overall survival than the stroma-negative group (P = 0.028). The cytoplasmic staining was not significantly correlated with invasion pattern in gallbladder carcinoma (P = 0.545). Univariate analysis demonstrated that laminin-5gamma2 stromal staining is a predictor of lymphatic invasion, venous invasion, neural invasion, the mode of subserosal infiltration, and lymph nodal status. Multivariate analysis revealed the mode of subserosal infiltration is the strongest predictor of stromal invasion (P = 0.068). In conclusion, high-grade cell proliferation and stromal laminin-5gamma2 staining were significantly correlated with a wall-invasion pattern of aggressive gallbladder carcinoma indicating destructive growth (DG type).

Distributed generation technologies, definitions and benefits

As a result of the application of deregulation in the electric power sector, a new identity appeared in the electric power system map known as “distributed generation” (DG). According to new technology, the electric power generation trend uses disbursed generator sized from kW to MW at load sits instead of using traditional centralized generation units sized from 100 MW to GW and located far from the loads where the natural recourses are available. This paper introduces a survey of this revolutionary approach of DGs, which will change the way electric power systems operate along with their types and operating technologies. Some important definitions of DGs and their operational constraints are discussed to help in understanding the concepts and regulations related to DGs. Furthermore, we will survey the operational and economical benefits of implementing DGs in the distribution network. Most DG literatures are based on studying the definitions, constructions or benefits of DGs separately. However, in our paper we aim to give a comprehensive survey by adding new classifications to relate the DG types, technologies and applications to each other.

Distributed generation technologies, definitions and benefits

As a result of the application of deregulation in the electric power sector, a new identity appeared in the electric power system map known as “distributed generation” (DG). According to new technology, the electric power generation trend uses disbursed generator sized from kW to MW at load sits instead of using traditional centralized generation units sized from 100 MW to GW and located far from the loads where the natural recourses are available. This paper introduces a survey of this revolutionary approach of DGs, which will change the way electric power systems operate along with their types and operating technologies. Some important definitions of DGs and their operational constraints are discussed to help in understanding the concepts and regulations related to DGs. Furthermore, we will survey the operational and economical benefits of implementing DGs in the distribution network. Most DG literatures are based on studying the definitions, constructions or benefits of DGs separately. However, in our paper we aim to give a comprehensive survey by adding new classifications to relate the DG types, technologies and applications to each other.

Chloroplast Composition and Structure Differences in a Soybean Mutant

A nuclear mutation of Glycine max (soybean) segregates 1:2:1 in regard to chlorophyll content. The heterozygous (LG) leaf blade contains about one-half the pigment content of the wild type (DG) per gram fresh weight. A lethal yellow (LY) type contains about 1 to 2% of the DG leaf pigment values. The chlorophyll a/b ratio in the LG is about 5 compared to about 2 in the DG. Protein/leaf values are lower in the LG and LY types when compared to DG. The LG plastid lamellae contain more protein/chlorophyll, cytochromes/chlorophyll, and quinones/chlorophyll than the DG. P(700)/chlorophyll values are similar in the DG and LG types.The chlorophyll-depleted LG and LY types had less total acyl lipids per leaf weight when compared to the DG type. Similar amounts of sulfolipid and phosphatidyl glycerol per protein residue weight were found in the LG and DG plastids; however, the monogalactosyl and digalactosyl diglycerides were reduced in the LG paralleling the chlorophyll depletion.Thin sections of leaf tissue show similar-sized LG and DG plastids but reduced grana formation in the LG. The LY has very few grana and very small grana compared to either DG or LG. The two characteristic particles revealed in higher plant chloroplasts by freeze-etching are about 15% smaller in the LG compared to the DG plants.