540 research outputs found

    Importance of etiologic diagnosis of hydrocephalus as illustrated by a case of Walker Warburg syndrome

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    Suprasellar epidermoid cyst: a rare cause of painless progressive bilateral vision loss-case report with clinico-radiological correlation

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    Intracranial epidermoid cysts are relatively rare lesions. They result from inclusion of ectodermal elements during time of neural tube closure. This lesion could rarely be acquired due to post-surgical or post traumatic implantation of the ectodermal components. They typically present in middle age group patients with evidence of loco-regional mass effect on adjacent structures. We present a clinico-radiological case report of the 27-year-old female patient who presented with painless progressive bilateral vision loss for last 4 months

    Studies on Physico-Mechanical and Explosive Characteristics of RDX/HMX-Based Castable Plastic-Bonded Explosives

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    Conventional cast explosives (RDX/TNT) have major drawbacks of poor mechanical properties,shrinkages and higher sensitivity .These properties can be improved by applying plastic bindersystems. The plastic-bonded explosive (PBX) is a composite material in which solid explosive particles are dispersed in a polymer matrix. The present paper describes the development of anitramine/hydroxy-terminated polybutadiene (HTPB)-based castable PBX. The PBXs were processed as per standard procedures. Bimodal/trimodal particle size system was selected to reach asolid loading of 88 wt per cent. High solid loading was made possible through proper combination ofcoarse/fine ratio of solid ingredients, which was based on a number of tap density experiments.Processability of the binder system was studied by using various wetting agents as well as by selectingbinder/plasticizer ratios. Mechanical properties of the PBXs were enhanced by different crosslinkingagents. The explosive properties ofPBXs including detonation velocity , processability and sensitivityto different types of stimuli, were studied. The results show that PBXs can be manufactured withdetonation properties better than those of composition B/octol with the added advantages of superiorthermal and sensitivity characteristics

    The Porcellini test: a novel test for accurate diagnosis of posterior labral tears of the shoulder: comparative analysis with the established tests

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    Questions/purposes: Although the posterior labral tears of the shoulder are known for their disabling clinical course, especially in overhead athletes, no clinical test used in isolation can diagnose it accurately in the preoperative period. We wanted to: (1) introduce “Porcellini test” with its radiological verification furnishing the anatomical basis of its mechanism; (2) determine its accuracy; and (3) compare its accuracy with that of the other established tests for diagnosing posterior labral tears of the shoulder. Methods: To determine the anatomical basis, we initially performed radiological verification of our test. Then, we evaluated its accuracy in a retrospective case-controlled study on 310 consecutive patients who underwent shoulder arthroscopic procedures at our hospital between January 2013 and December 2013. All patients were examined preoperatively for Porcellini test, and the presence of posterior labral tear was confirmed on arthroscopy. Later, in a cohort study on 91 consecutive patients who underwent shoulder arthroscopic procedures, we compared its accuracy with O’Brien’s test, the Kim test, the Jerk test, and the Load and Shift test. The accuracy was interpreted in terms of sensitivity, specificity, and predictive values. Results: The radiological verification conferred the anatomical basis for the mechanism of the Porcellini test. This new test showed high accuracy for posterior labral tears with sensitivity of 100 %, specificity of 99.3 %, the positive and negative predictive values of 92.6 and 100 %, respectively. Also, it had superior accuracy results than every other test. The interexaminer reliability for all test results was found to be >0.80. Conclusions: We propose “Porcellini test” as a simple, accurate, reproducible, and reliable test for the preoperative diagnosis of posterior labral tears of shoulder

    Curious case of corpus callosal hematoma in a normotensive post-partum female patient: a case report of reversible post-partum angiopathy with clinico-radiological correlation

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    Postpartum cerebral angiopathy (PCA) is a rare cause of stroke in the puerperium. It usually presents with episodes of headache, seizures and neurological deficits in early post-partum period in normotensive females. CT, MRI and catheter angiography may demonstrate segmental vasoconstriction that often resolves spontaneously. PPA is generally regarded as a benign, non-relapsing and reversible disease process. We present a clinico-radiological correlative case of isolated corpus callosal hematoma in a post-partum normotensive female with evidence of intracranial vascular spasm and luminal irregularity on CT and catheter angiography. Follow up MR angiography showed resolution of the vasospasm and luminal irregularity. Patient was managed conservatively and showed resolution of the symptoms in follow up visit on 8th week.

    Simplified Burn-Rate Model for CMDB Propellants

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    A single model has been proposed to predict the burning rates of bimodal AP,RDX and aluminum containing CMDB propellants. This is done in terms of the respective physical constants on the basis of a recently developed model of combustion of CMDB propellants. The study has been carried out to examine the effects of changes in propellants composition, AP particle size and pressures on burning rate. Computer programs were developed for this purpose and the results obtained for typical sets of input data have been presented and compared with the actual results

    Vulnerability analysis of satellite-based synchronized smart grids monitoring systems

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    The large-scale deployment of wide-area monitoring systems could play a strategic role in supporting the evolution of traditional power systems toward smarter and self-healing grids. The correct operation of these synchronized monitoring systems requires a common and accurate timing reference usually provided by a satellite-based global positioning system. Although these satellites signals provide timing accuracy that easily exceeds the needs of the power industry, they are extremely vulnerable to radio frequency interference. Consequently, a comprehensive analysis aimed at identifying their potential vulnerabilities is of paramount importance for correct and safe wide-area monitoring system operation. Armed with such a vision, this article presents and discusses the results of an experimental analysis aimed at characterizing the vulnerability of global positioning system based wide-area monitoring systems to external interferences. The article outlines the potential strategies that could be adopted to protect global positioning system receivers from external cyber-attacks and proposes decentralized defense strategies based on self-organizing sensor networks aimed at assuring correct time synchronization in the presence of external attacks

    Percutaneous tricuspid valvotomy for pacemaker lead-induced tricuspid stenosis

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    AbstractPermanent pacemaker lead-induced tricuspid regurgitation is extremely uncommon. We report a patient with severe tricuspid stenosis detected 10 years after permanent single chamber pacemaker implantation in surgically corrected congenital heart disease. The loop at the level of the tricuspid valve may have caused endothelial injury and eventually led to stenosis. Percutaneous balloon valvotomy for such stenosis has not been reported from India

    A REVIEW ON INDIRECT SOLAR DRYERS

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    ABSTRACT Solar drying is one of the most ancient and simplest forms of drying known to mankind. Even today, most of the agricultural produce such as grains, spices, fruits and vegetables are dried under the sun. However, drying these products directly under the open sun has many drawbacks such as debris, rain, blowing wind, insect infestation, human and animal interference etc. which leads to contamination of the products. By the use of solar dryers, such problems can be easily overcome. Thus, there is a need to make the solar dryers more efficient and cheaper. There are various types of solar dryers developed and are classified based on the mode of air circulation, such as, natural circulation and forced circulation solar dryers; based on the type of drying, like, direct solar drying, indirect solar drying and mixed mode solar drying; material to be dried; types of operation e.g., batch or continuous, etc. In case of direct type solar dryers, the products are exposed directly to solar radiation which reduces the quality of the products. Also, the drying rate is very low in direct type solar dryers. These disadvantages are overcome by indirect type solar dryers. In this paper, we did a comprehensive review of various new technologies in indirect type solar dryers. We reviewed how these dryers fare against open sun drying and against each other and also, all the different enhancement techniques applied to them, in order to improve their efficiency and reduce the drying times

    Quality engineering of a traction alternator by robust design

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    Robust design is an engineering methodology for improving productivity during research and development so that high-quality products can be developed and produced quickly and at low cost. A large electrical company was developing traction alternators for a diesel electrical engine. Customer requirement was to obtain very high efficiency which, in turn, was influenced by several design parameters. The usual approach of the 'design-build-test' cycle was considered time-consuming and costly; it used to take anywhere from 4 months to 1 year before finalizing the product design parameters as it involved physical assembly and also testing. Instead, the authors used Taguchi's parameter design approach. This approach took about 8 weeks to arrive at optimum design parameter values; clearly demonstrating the cutting edge of this methodology over the traditional design-build-test approach. The prototype built and tested accordingly gave satisfactory overall performance, meeting and even exceeding customer requirements
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