Mechanism of saline deposition and surface flashover on high-voltage insulators near shoreline:mathematical models and experimental validations

This paper deals with sea salt transportation and deposition mechanisms and discusses the serious issue of degradation of outdoor insulators resulting from various environmental stresses and severe saline contaminant accumulation near the shoreline. The deterioration rate of outdoor insulators near the shoreline depends on the concentration of saline in the atmosphere, the influence of wind speed on the production of saline water droplets, moisture diffusion and saline penetration on the insulator surface. This paper consists of three parts: first a model of saline transportation and deposition, as well as saline penetration and moisture diffusion on outdoor insulators, is presented; second, dry-band initiation and formation modelling and characterization under various types of contamination distribution are proposed; finally, modelling of dry-band arcing validated by experimental investigation was carried out. The tests were performed on a rectangular surface of silicone rubber specimens (12 cm × 4 cm × 8 cm). The visualization of the dry-band formation and arcing was performed by an infrared camera. The experimental results show that the surface strength and arc length mainly depend upon the leakage distance and contamination distribution. Therefore, the model can be used to investigate insulator flashover near coastal areas and for mitigating saline flashover incidents.</p

Market Chain Analysis of High Value Fruits in Bench Maji Zone, Southwest Ethiopia

This research aimed at assessing the market chain of banana, avocado and mango fruits in Bench Maji zone. Both primary and secondary data were collected from 2 purposively selected fruits producing districts namely North Bench and South Bench districts. Primary data were collected through semi-structured questionnaire and focus group discussion. A total of 150 households were selected by using systematic random sampling technique. In addition, 40 traders were selected by using simple random sampling technique. Market structure-conduct-performance analysis model was used to assess the performance of the fruits market. The result revealed that the participants in the fruits markets were identified as primary actors and secondary actors. Primary actors in the fruits market chain were producers, brokers/agents/, farmer traders, collectors, and wholesalers. Whereas, local tax authority, local police, transporters, and district Trade and Industry office were identified as secondary actors.  Fruits market in the area was characterized by non-competitive nature with concentration ratio ranging from 42 to 91.10% indicating the existence of oligopoly market structure. Entrance and exit in the fruits market was blocked by licensing and access to channel. A channel that links producers to local wholesalers through brokers was more efficient in terms of large volumes of sales. However, performance of the fruits market was affected by seasonality, the existence of few big traders, limited access to information, absence of organized market center and brokers’ interference. Therefore, attention has to be given to alleviate the problems so as to improve the performance of the fruits market. Keywords: Market chain, oligopoly, market concentration ratio and market performanc

Influence of National Indicators on KSE Stock Index Variation

The aim of this research article is investigates perceptions of Karachi Stock Exchange (KSE) stake holders regarding  influence of national indictors affecting on Karachi Stock Exchange index. Self-administered structured questionnaire distributed conveniently among 140 stake holders of Karachi Stock Exchange. Data analysed through SPSS version 20 and descriptive statistics mean frequency and % exposed; Karachi Stock Exchange stake holders perceived that national indicators have significant influence on Karachi Stock Exchange index variation. Results determine that due to political uncertainty in Pakistan effect on Karachi Stock Exchange Index variation. Conclusion matched with findings of previous studies also

INTELLECTUAL CAPITAL PRACTICES AND FINANCIAL EFFICIENCY: A MEDIATING ROLE OF BANKS’ PERFORMANCE: EVIDENCE FROM THE BANKING SECTOR OF PAKISTAN

The study attempts to examine the impact of intellectual capital(IC) practices (i.e. human capital, structural capital and relationalcapital practices) on financial efficiency through mediating the roleof bank performance. We collected data for 518 banks’ professionalsthrough questionnaire and use the direct path way and multipleregression to examine the impact of IC practices on mediating variable(bank performance) and mediating variable on dependent variable(financial efficiency). The results reveal that the proposed hypothesesare statistically significant (p&lt;0.01) and that banks’ performancepartially mediates the relationship between IC practices and banks’financial efficiency. This study provides valuable insights on theimpact of IC practices on financial efficiency of banks throughmediation of bank performance. The tested theoretical relationshipreveals that banks which are more involved in IC practices get betterresults than their competitors

Influence of control mechanism on the flow field of duct at Mach 1.2 for area ratio 2.56

In this paper, the outcome of the experimental investigation and the flow field development in the duct at a supersonic Mach number of 1.2 is presented. The experiments were conducted at various NPR which covers the condition of correct expansion and under expansion. A Convergent-divergent (C-D) nozzle which is connected with the suddenly expanded duct of the diameter of 16 mm of area ratio 2.56. The recirculation zone is controlled by using the microjets of 1 mm of orifice diameter which is placed at 90 degrees interval at 6.5 mm from the central axis of the main jet. The L/D of the duct was used in the investigation was from 1 to 10, and the NPR at which the experiments were conducted considered are in the range from 3, 5, 7, 9 and 1

Modeling and analysis of convergent divergent nozzle with sudden expansion duct using finite element method

n most of the engineering problems, the sudden expansion at the base is encountered in automobile industries, at the base of the fuselage of the aircraft, at the base of the artillery shells, at the base of the unguided rockets and missiles. At transonic Mach numbers, the contribution of the base drag is more than sixty percent. Hence it is mandatory on the part of the researcher to control the base pressure, depending upon the situation. For external aerodynamics, the base pressure should be closed to the ambient pressure to make base drag almost zero. However, for combustion chambers, the base pressure should be very low so that fuel-air mixing is so that the combustor is efficient. With this idea in mind, this study was undertaken. A finite element (FE) the method has been used to investigate the effectiveness of the microjets on wall pressure distribution in a convergent-divergent (CD) nozzle with sudden expansion. For control of the base pressure, four microjets of 1 mm orifice diameter placed at 90- degree intervals along a pitch circle distance (PCD) of 1.3 in the base region were used as a control mechanism. The variables considered are the Mach number, area ratio, and length-to-diameter ratio (L/D) as 2.2, 2.56, and 8. The simulation was done for nozzle pressure ratio (NPR) 3, 5, 7, 9, and 11 with and without the presence of the microjets. The current results for all the cases of this study indicate that one can identify the Mach number, NPR, and the L/D, which will result in a maximum increase in the pressure. Moreover, the results also proved that the influence of microjet control does not affect the flow field in the duct adversely. The two-dimensional planar CD nozzle with sudden expansion duct has been modeled, and analyses using the K-ε turbulence model independently checked with the ANSYS tool

Modelling and analysis of convergent divergent nozzle with sudden expansion duct using finite element method

In most of the engineering problems, the sudden expansion at the base is encountered in automobile industries, at the base of the fuselage of the aircraft, at the base of the artillery shells, at the base of the unguided rockets and missiles. At transonic Mach numbers, the contribution of the base drag is more than sixty percent. Hence it is mandatory on the part of the researcher to control the base pressure, depending upon the situation. For external aerodynamics, the base pressure should be closed to the ambient pressure to make base drag almost zero. However, for combustion chambers, the base pressure should be very low so that fuel-air mixing is so that the combustor is efficient. With this idea in mind, this study was undertaken. A finite element (FE) method has been used to investigate the effectiveness of the microjets on wall pressure distribution in a convergent-divergent (CD) nozzle with sudden expansion. For control of the base pressure, four microjets of 1 mm orifice diameter placed at 90- degree intervals along a pitch circle distance (PCD) of 1.3 in the base region were used as a control mechanism. The variables considered are the Mach number, area ratio, and length-to-diameter ratio (L/D) as 2.2, 2.56, and 8. The simulation was done for nozzle pressure ratio (NPR) 3, 5, 7, 9, and 11 with and without the presence of the microjets. The current results for all the cases of this study indicate that one can identify the Mach number, NPR, and the L/D, which will result in a maximum increase in the pressure. Moreover, the results also proved that the influence of microjet control does not affect the flow field in the duct adversely. The two-dimensional planar CD nozzle with sudden expansion duct has been modelled, and analyses using the K-ε turbulence model independently checked with the ANSYS tool

The Arab Journal of Forensic Sciences and Forensic Medicine (AJFSFM): A new era of sharing knowledge and research

Education and research are indispensable tools for the scientific and economic growth of a nation, and it is of the greatest importance to have effective mechanisms which provide the academic and scientific community with the latest research and recent developments in their respective fields of expertise. This rapid broadcasting of scientific information not only facilitates their research but also contributes towards exciting new discoveries. Scientific journals and magazines are one of the best means to facilitate the dissemination of vital research and other information essential to the academic and scientific community. At present, there are more than 28,000 scholarly journals serving the scientific community, researchers, students, and professionals worldwide

Market Chain Analysis of High Value Fruits in Multan Region

This research aimed at assessing the market chain of banana, avocado and mango fruits in Multan zone. Both primary and secondary data were collected from 2 purposively selected fruits producing districts namely North Multan and South Multan areas. Primary data were collected through semi-structured questionnaire and focus group discussion. A total of 150 households were selected by using systematic random sampling technique. In addition, 40 traders were selected by using simple random sampling technique. Market structure-conduct-performance analysis model was used to assess the performance of the fruits market. The result revealed that the participants in the fruits markets were identified as primary actors and secondary actors. Primary actors in the fruits market chain were producers, brokers/agents/, farmer traders, collectors, and wholesalers. Whereas, local tax authority, local police, transporters, and district Trade and Industry office were identified as secondary actors.  Fruits market in the area was characterized by non-competitive nature with concentration ratio ranging from 42 to 91.10% indicating the existence of oligopoly market structure. Entrance and exit in the fruits market was blocked by licensing and access to channel. A channel that links producers to local wholesalers through brokers was more efficient in terms of large volumes of sales. However, performance of the fruits market was affected by seasonality, the existence of few big traders, limited access to information, absence of organized market center and brokers’ interference. Therefore, attention must be given to alleviate the problems to improve the performance of the fruits market.