3,908 research outputs found

    Heat Release Analysis and Modeling for a Common-Rail Diesel Engine

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    The main purpose of this study was to perform a heat release analysis in order to formulate a heat-release model for a common-rail diesel engine. The fundamental idea of the model is to describe the observed physical processes with empirical formulas based on the experimental data. A Fiat 2.4Liter common rail engine was used in the tests. A rotary incremental encoder with 0.1° resolution was coupled to the crankshaft pulley with a special adapter. The engine was operated at a number of different speeds and load conditions. Cylinder pressure data was recorded using a high-speed data acquisition system. The data acquisition was done at variable sampling speeds; encoder signal at every 0.1° dictated the sampling speed for data-acquisition. Cylinder pressure data was logged for 100 cycles at each operating condition. This raw data was averaged and used for further analysis. The actual rate of heat-release/crank angle was evaluated using the first law of thermodynamics. The heat release data was modeled using Weibe functions. Two such functions were used: one to describe the pilot burning and the other to describe the main burning stage of the combustion process. The coefficients and parameters in the model were adjusted to match the observed heat release diagram. Actual cylinder pressure versus crank angle traces were compared with predicted cylinder pressure versus crank angle traces for verification of the technique

    Continuous maintenance and the future – Foundations and technological challenges

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    High value and long life products require continuous maintenance throughout their life cycle to achieve required performance with optimum through-life cost. This paper presents foundations and technologies required to offer the maintenance service. Component and system level degradation science, assessment and modelling along with life cycle ‘big data’ analytics are the two most important knowledge and skill base required for the continuous maintenance. Advanced computing and visualisation technologies will improve efficiency of the maintenance and reduce through-life cost of the product. Future of continuous maintenance within the Industry 4.0 context also identifies the role of IoT, standards and cyber security

    An Object-Oriented Information Systems Course

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    An Object-oriented information systems course taught at the senior level is described. C++ is used as the language to teach object-orientation. In addition to the language, analysis and design concepts are integrated into the course. A topic outline for the course is described. Course materials used to teach such a course and the projects assigned are presented. Concepts that need to be stressed such as encapsulation, inheritance and polymorphism are reviewed. The impact of OO approaches on databases, software development are discussed. The teaching of C++ in a DOS based environment as opposed to using GUI based methods is briefly discussed

    Study on Characteristics and Outcome of Paediatric Eye Injuries (SCOPE)

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    The limitations in our study are, 1. The follow up is only for a brief period of time and the population size is small. Long term follow up of a larger population of children with eye injuries would provide information that is crucial to completely assess the public health impact of pediatric eye trauma and its associated ocular morbidity. 2. The Incidence of permanent visual loss cannot be predicted from the incidence rates of eye injuries because many of the vision-threatening complications of such injuries (eg. retinal detachment, cataract) develop months after the initial event. 3. Many of the patients in our study came from socioeconomic situations that did not allow for regular follow-up evaluation. 4. The current study included only children who presented to us with a primary diagnosis of ocular trauma excluding those with traumatic injury who would have sought neurosurgery or plastic surgery services. 5. This study did not investigate how the management of a condition should be adjusted or improved based on individual etiology. This topic requires an additional prospective study in the future. Though there are limitations, an important point that can be concluded from the data presented in this study is that it clearly indicates that the majority of pediatric eye injuries are preventable. Diwali crackers are more dangerous. The cornea shows the highest incidence of involvement because it is the most exposed part of the eye ball. The necessity of seeking professional medical help soon after the injury and the danger of delaying treatment should be stressed. To maximize outcomes, immediate and careful evaluation and treatment by ophthalmologists is advocated. The present survey confirms that elementary schoolchildren are the most vulnerable age group who cannot be fully responsible for their actions. Hence, parents and carers need education in preparing the home environment to be safe for children. Adequate supervision and appropriate ocular protection for children must be stressed especially when using sharp tool or scissors. Safer tools such as blunt nosed scissors should be provided and access to sharp or dangerous household utensils should be restricted. Plants with thorns are not suitable in gardens with children. Games involving throwing projectiles should be disallowed. The government should take action legally to abolish the habit of bursting crackers for Diwali. If it is not possible, children should be supervised by responsible adults while bursting crackers. Possible avenues of dissemination of this information would be through schools, medical practices and baby health clinics and through media

    Integrating Multimedia Topics in Graphics Courses

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    This paper specifies an approach to include multimedia topics in computer graphics courses in MIS programs. It identifies multimedia topics that need to be covered such as compression technology, system architecture, and the development of multimedia applications. It suggests a sequence of projects that introduce one media for each project, and culminates in a multimedia presentation. The paper also identifies the configuration of multimedia equipment required to support the course. Student perceptions and feedback are also discussed

    Spectra of generalized corona of graphs constrained by vertex subsets

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    In this paper, we introduce a generalization of corona of graphs. This construction generalizes the generalized corona of graphs (consequently, the corona of graphs), the cluster of graphs, the corona-vertex subdivision graph of graphs and the corona-edge subdivision graph of graphs. Further, it enables to get some more variants of corona of graphs as its particular cases. To determine the spectra of the adjacency, Laplacian and the signless Laplacian matrices of the above mentioned graphs, we define a notion namely, the coronal of a matrix constrained by an index set, which generalizes the coronal of a graph matrix. Then we prove several results pertain to the determination of this value. Then we determine the characteristic polynomials of the adjacency and the Laplacian matrices of this graph in terms of the characteristic polynomials of the adjacency and the Laplacian matrices of the constituent graphs and the coronal of some matrices related to the constituent graphs. Using these, we derive the characteristic polynomials of the adjacency and the Laplacian matrices of the above mentioned existing variants of corona of graphs, and some more variants of corona of graphs with some special constraints.Comment: 22 pages, 1 figur

    STUDIES ON ACUTE TOXICITY OF HEPTOPLUS IN EXPERIMENTAL RATS

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    Objective: To evaluate acute toxicity of Heptoplus (polyherbal drug) in Sprague-Dawley rats and to identify the active ingredients of the herbal drug.Methods: Heptoplus was subjected to preliminary phytochemical screening and the HPTLC fingerprint profile of herbal drug was documented. OECD guideline 423-Acute toxic class method was followed to evaluate the oral toxicity of Heptoplus in Sprague-Dawley rats. In acute toxicity studies, Group I (control) rats received 0.5% of carboxymethyl cellouse (Vehicle). Group II rats received 2000 mg/kg b. w of Heptoplus. The rats were observed on the day of dosing and thereafter for 14 d, for any toxic effect. Results: Preliminary phytochemical analysis of Heptoplus revealed total phenol, flavonoid, carbohydrate, and tannins as its major constituents. The total phenol and flavonoid content of Heptoplus was found to be 170 μg of gallic acid and 162 μg of quercetin equivalent. HPTLC analysis proved that phyllanthin is an active compound of Heptoplus. Acute oral toxicity assays showed Heptoplus administration did not result in any treatment-related mortality, abnormal clinical signs, and loss of body weight or gross pathological changes in rats. Hence, LD50 value of Heptoplus was found to be greater than 2000 mg/kg b. wt.Conclusion: Heptoplus contain phyllanthin as an active ingredient. LD50 value of Heptoplus was found to be greater than 2000 mg/kg b. wt

    Identification and description of Indian parasitic bee genus Sphecodes Latreille 1804, (Halictidae: Hymenoptera)

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    The present study provides an updated knowledge on taxonomy of three important species of Sphecodes Latreille, 1804 which were collected from different parts of India. Three species viz., Sphecodes iridipennis Smith 1879, S. gibbus Smith 1853, S. crassicornis Smith 1879 are redescribed with illustrations, genitalic features and measurements of their morphological features. An annotated checklist of species Sphecodes from India also provided

    Micromanagement: An Employee’s Adversary

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    Leadership is the ability of an individual to initiate guidance and influence a group or an organization in order to maximize its performance. Micromanagement leadership is one such form, where the managers closely monitor and direct their subordinates. Although a select few managers and employees could benefit from such a practice, micromanagement, as a leadership style has relatively more negative implications on an employee’s behavior and his engagement towards the work at hand. This creates a sense of perceived stress leading him to behave in a counterproductive manner. In this article, we have intended to develop a theoretical framework by investigating from an employee’s perspective. Thus, highlighting the various implications of micromanaging. Interrelating the concepts of employee disengagement, perceived stress and deviant behavior, our study provides several implications for organizations and managers alike apart from a theoretical literature base for further study. Keywords: Micromanagement, Employee Disengagement, Perceived Stress, Leadershi

    EFFECT OF HEPTOPLUS ON ISONIAZID AND RIFAMPICIN INDUCED HEPATOTOXICITY IN LIVER CELL LINES

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    Objective: To evaluate the hepato protective role of Heptoplus (HP), a ployherbal formulation as a supplementary agent for the Isoniazid and Rifampicin induced oxidative stress and apoptosis in liver. Methods: Liver cell lines were divided in to five groups. Group I is control, group II is treated with 30ng/ml of INH+RIF, group III, IV and V are supplemented with 50, 100 and 200 ng/ml of HP. At the end of the experimental period, biochemical tests for liver marker enzymes and antioxidant profile were studied. Gene expression for apoptosis and CYP2E1 was also studied.Result: Cells in group II suffer from severe oxidative stress and hepatotoxicity, as seen by significant decreases of (p≤0.001) reduced glutathione, catalase (p≤0.01) and superoxide dismutase (p≤0.001) and significant increase (p≤0.01) of liver marker enzymes. However, liver cell lines nourished with 50, 100 and 200 ng/ml of HP were protected from oxidative stress and maintained normal antioxidant profile and liver marker enzymes in a dose dependent manner. Hepatocytes in group II, displayed significant (p≤0.001) up regulation of CYP2E1, BAX, P53 and caspases 3 and significant (p≤0.001) down regulation of Bcl2 gene expression. Concomitant applications of HP protected the hepatocytes from programmed cell death by conserving normal CYP2E1expression and enhancing the protective action of Bcl2 by up regulating the expression on dose dependent manner. Conclusion: Heptoplus prevented oxidative stress and apoptosis, in hepatocytes.Â
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