61 research outputs found

    High Speed Railway (HSR): India And The World

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    India has one of the largest rail networks in the world but has no line which can be classified as HSR allowing operational speed of 125mph. The current fastest train runs at 100 mph over a distance of only around 100 miles. However, supported by a robust political willingness, a new HSR corporation has been set up to kick-start the HSR projects from ideation to reality. Four major corridors have been identified and pre-feasibility studies have been commissioned. The first in this ambitious program is the HSR between Mumbai and Ahmedabad, two major population and commercial centers in the west of India. The success or failure of this project could show the way for future road map of HSR in India. This paper identifies and analyses the countries where HSR systems are in operation – their political, economic and social conditions relevant to HSR systems and then the features of HSR systems themselves to understand the commonalities between the nations that have opted for HSR. The objective is to identify if there is a common character or a baseline characteristic in terms of geographical, economic, political and social conditions which are essential to be a member of this exclusive club? Is there a standard financial and business model that has been adopted by these countries?Theattempt is also to compare these baseline benchmarks with those in India, to assess its strengths and weaknesses and reaffirm the chances of its success in taking up this project, one of the biggestever in its history. The results would be relevant not only for India but for all countries who aspire to be HSR countries in near future

    Review Based Study On Risk Management Model For High Speed Indian Railway System

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    In this paper, a framework for risk management at railways has been studied and integrated into global safety management system of railways. Furthermore we studied how it was applied to a manually controlled full barrier road rail level crossing in Morocco. We studied different aspects that should be considered during the system definition phase where we suggested using functional diagrams for modeling operations at LC from the perspective of LC actors. It is a critical part for risk management and specifically for hazard identification where we provided different techniques that can be used; our experience shows that involvement of all stakeholders is a prerequisite to the success to this phase. Initiating events can be unveiled through brainstorming sessions and FTA can model complex interactions of events that have the potential to lead to accidents. Risk analysis can then be carried out provided that historical LC accident and incident data is available to estimate frequencies and consequences; ETA is the ideal tool for estimating consequences of hazards due to multiple causes. The existing risks are then classified and decisions are made regarding their tolerability, the ALARP principle can serve this purpose. A cost benefit analysis then helps prioritize risk treatment actions that should target intolerable risks. Control mechanisms should be also put in place to assess, monitor and review the risk control actions put in place. Finally, it is emphasized on the importance of having a database of historical accidents and incidents at LC for the success and efficiency for the suggested framework. Accidents at level crossings are the result of complex interactions between factors arising from the design and operations of level crossings. An important first step towards eliminating the causes of these accidents is thru understanding and assessing the risks associated with a given level crossing and acting on them. This paper presents review based study on risk management framework that serves this purpose

    How CSR is conducted in Zambia. What drivers, issues and processes are used? An Analysis of the Lusaka Stock Exchange (LSE) companies.

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    The notion corporate social responsibility developed from the western world is a new concept in Zambia. Researchers have suggested that the concept of CSR can make positive contributions to companies operating in African and developing countries as it has done in western countries. This research study aims to offer how companies listed in the Lusaka Stock Exchange (LSE) market in Zambia use CSR. Frameworks used in CSR will used to investigate this research with the main focus on institutional theory (IT). The research will evaluate CSR in Zambia by seeing which IT pressures (normative, regulative and cultural-cognitive) are adopted by Zambian companies. The study relies on secondary data done from web content analysis of websites of each company listed in the LSE as well as literature surrounding the adoption of CSR in the Zambian context. The findings from this research reveal that there are various types of CSR present in Zambian companies. Different institutional pressures encourage different companies. Specifically, normative and culture-cognitive pressures, where as, regulatory pressures by the government are very minimal. Companies all focus on different issues and processes. However there is isomorphism between companies leading to companies taking similar approaches of CSR. Zambian companies mainly focus on philanthropic CSR, which is mainly giving back to the society. This is very different in western countries as suggested by Carroll (1991) where priority is given to economic and legal responsibilities while philanthropic are given the least. So CSR in Zambia is developed to suit the needs of the community, hence, companies implement CSR activities accordingly. This research recommends that government needs to introduce regulations to companies in order to practice effective CSR the same recommendation given by Gilberts (2008) research on CSR in Kenya

    Return to play following spine surgery

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    Return to physical activity is a primary concern for adolescents with idiopathic scoliosis who are indicated for spinal fusion surgery. Preoperative counseling often addresses questions regarding ability to return to sport, postoperative restrictions, time away from play, and the safety of returning to activities. Previous works have shown that flexibility can noticeably decrease after surgery, and that the ability to return to the same level of play may be impacted by the levels of the spine included in the fusion. Equipoise remains on when patients should be allowed to return to non-contact, contact, and collision play; however, there is a trend toward earlier release to activities over the last few decades. Sources agree, though, that returning to play is safe, with rare instances of complications reported for patients with spinal fusion. Here, we review the literature on the function of spinal fusion levels on flexibility and biomechanics, address factors that may influence one's recovery of sports performance, and discuss safety considerations regarding return play following spine surgery

    Self-similar rupture of thin films of power-law fluids on a substrate

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    Thinning and rupture of a thin film of a power-law fluid on a solid substrate under the balance between destabilizing van der Waals pressure and stabilizing capillary pressure is analysed. In a power-law fluid, viscosity is not constant but is proportional to the deformation rate raised to the n−1 role= presentation style= box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; font-variant: inherit; font-stretch: inherit; line-height: normal; font-family: inherit; vertical-align: baseline; display: inline; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; position: relative; \u3en−1n−1 power, where 00n=1n=1 for a Newtonian fluid). In the first part of the paper, use is made of the slenderness of the film and the lubrication approximation is applied to the equations of motion to derive a spatially one-dimensional nonlinear evolution equation for film thickness. The variation with time remaining until rupture of the film thickness, the lateral length scale, fluid velocity and viscosity is determined analytically and confirmed by numerical simulations for both line rupture and point rupture. The self-similarity of the numerically computed film profiles in the vicinity of the location where the film thickness is a minimum is demonstrated by rescaling of the transient profiles with the scales deduced from theory. It is then shown that, in contrast to films of Newtonian fluids undergoing rupture for which inertia is always negligible, inertia can become important during thinning of films of power-law fluids in certain situations. The critical conditions for which inertia becomes important and the lubrication approximation is no longer valid are determined analytically. In the second part of the paper, thinning and rupture of thin films of power-law fluids in situations when inertia is important are simulated by solving numerically the spatially two-dimensional, transient Cauchy momentum and continuity equations. It is shown that as such films continue to thin, a change of scaling occurs from a regime in which van der Waals, capillary and viscous forces are important to one where the dominant balance of forces is between van der Waals, capillary and inertial forces while viscous force is negligible

    Inertial impedance of coalescence during collision of liquid drops

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    The fluid dynamics of the collision and coalescence of liquid drops has intrigued scientists and engineers for more than a century owing to its ubiquitousness in nature, e.g. raindrop coalescence, and industrial applications, e.g. breaking of emulsions in the oil and gas industry. The complexity of the underlying dynamics, which includes occurrence of hydrodynamic singularities, has required study of the problem at different scales – macroscopic, mesoscopic and molecular – using stochastic and deterministic methods. In this work, a multi-scale, deterministic method is adopted to simulate the approach, collision, and eventual coalescence of two drops where the drops as well as the ambient fluid are incompressible, Newtonian fluids. The free boundary problem governing the dynamics consists of the Navier–Stokes system and associated initial and boundary conditions that have been augmented to account for the effects of disjoining pressure as the separation between the drops becomes of the order of a few hundred nanometres. This free boundary problem is solved by a Galerkin finite element-based algorithm. The interplay of inertial, viscous, capillary and van der Waals forces on the coalescence dynamics is investigated. It is shown that, in certain situations, because of inertia two drops that are driven together can first bounce before ultimately coalescing. This bounce delays coalescence and can result in the computed value of the film drainage time departing significantly from that predicted from existing scaling theories

    Medicalization of sexuality and sexual health: A perspective review

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    Sexuality has become a medical issue in the context of aging due to a variety of aspects, such as growing life expectancy, an optimistic societal paradigm that indorses sexuality as significant for the superiority of life with age, and the medicalization of sexuality with the emergence of remedial medicines to extravagance sexual dysfunction. At any age, a reduction in the desire for sexual activity or inadequate performance of sexual intercourse is considered atypical and requires a medicinal treatment response. However, despite concerns that this is leading to an unhealthy obsession with sexuality from a medical perspective, this line of thinking is likely to continue. In this context, people can identify and take advantage of sexual problems. Sexual desire and performance are affected by normal physiological changes associated with aging in both genders. Medical experts must understand these changes to optimize sexual functioning in older patients. Sexual health can only be improved by addressing both sexual rights and enjoyment, even in the current politically charged context. Through legislation, programming, and lobbying, we may all work to enhance health, happiness, and quality of life by fostering more positive associations between sexual health, sexual rights, and sexual pleasure. This calls for not just a thorough understanding of the real-world consequences of these ideas' interconnectivity, but also conceptual, individual, and systemic approaches that properly acknowledge and alleviate the problems imposed on people's lives due to insufficient consideration of these links. This review describes the factors associated with aging and sexuality, the normalization and medicalization of sexual health, and unusual situations associated with aging, including institutionalized care and the prospects of elder abuse

    A meta-analysis on efficacy and safety: single-balloon vs. double-balloon enteroscopy

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    Background and aim: Double-balloon enteroscopy (DBE) and single-balloon enteroscopy (SBE) are new techniques capable of providing deep enteroscopy. Results of individual studies comparing these techniques have not been able to identify a superior strategy. Our aim was to systematically pool all available studies to compare the efficacy and safety of DBE with SBE for evaluation of the small bowel. Methods: Databases were searched, including PubMed, Embase, and the Cochrane Central Register of Controlled Trials. The main outcome measures were complete small-bowel visualization, diagnostic yield, therapeutic yield, and complication rate. Statistical analysis was performed using Review Manager (RevMan version 5.2). Meta-analysis was performed using fixed-effect or random-effect methods, depending on the absence or presence of significant heterogeneity. We used the χ2 and I2 test to assess heterogeneity between trials. Results were expressed as risk ratios (RR) or mean differences with 95% confidence intervals (CI). Results: Four prospective, randomized, controlled trials with a total of 375 patients were identified. DBE was superior to SBE for visualization of the entire small bowel [pooled RR = 0.37 (95% CI: 0.19–0.73; P = 0.004)]. DBE and SBE were similar in ability to provide diagnosis [pooled RR = 0.95 (95% CI: 0.77–1.17; P = 0.62)]. There was no significant difference between DBE and SBE in therapeutic yield [pooled RR = 0.78 (95% CI: 0.59–1.04; P = 0.09)] and complication rate [pooled RR = 1.08 (95% CI: 0.28–4.22); P = 0.91]. Conclusions: DBE was superior to SBE with regard to complete small bowel visualization. DBE was similar to SBE with regard to diagnostic yield, ability to provide treatment and complication rate, but these results should be interpreted with caution as they is based on very few studies and the overall quality of the evidence was rated as low to moderate, due to the small sample size
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