880 research outputs found

    Optimization of Electrostatically Actuated Miniature Compressors for Electronics Cooling

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    This paper explores the feasibility of using electrostatically actuated diaphragm compressors in a miniature-scale refrigeration system for electronics cooling. A previously developed experimentally validated analytical model for the diaphragm compressor is used in conjunction with an optimization approach to determine the required dimensions for the compressor. The analysis reveals that the pressure rise and volume flow rate required for the electronics cooling application are not achieved using a single compressor because of material property limitations. A three-dimensional array of compressors is proposed instead with which the cooling requirements and the size restrictions for electronics cooling applications may be simultaneously satisfied

    Effect of Cooling Conditions, Retrofitting on Strength of Concrete Subjected to Elevated Temperature

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    Concrete has a high degree of fire resistance at moderate temperatures. High temperatures, however, cause concrete to lose its stiffness and strength. The effects of cooling techniques and retrofitting on the strength of concrete exposed to high temperatures have not been synchronized in previous studies. This experimental research aims to evaluate the effect of cooling conditions and the effectiveness of retrofitting concrete subjected to elevated temperatures. Four types of concrete: M 20 normal concrete (NC); M 20 metakaolin concrete (MC); M 40 standard concrete (SC); and M 40 self-compacting concrete (SCC) are considered in this study. A total of 864 samples consisting of cube, beam, and cylinder specimens are subjected to sustained elevated temperatures of 400oC, 600oC, and 800oC for 2 hours rating. The weight and strength of half of the heat-damaged samples are assessed following natural air cooling (NAC) and water jet cooling (WJC). The remaining 50% of samples retrofitted with carbon fiber reinforced polymer (CFRP) are tested to evaluate the upgraded strength. The experimental findings demonstrate that water jet cooling (WJC) causes more strength degradation, and CFRP proves to be effective in restoring the strength of heat-deteriorated specimens. Overall, self-compacting concrete (SCC) has shown high resistance to elevated temperatures. Doi: 10.28991/CEJ-2023-09-07-013 Full Text: PD

    Smart Attendance System

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    N day - to - day lives there are different types of identification system are present For the detection of Animals, students , products and also for transportation. The system like Barcode system, Smart - card and Bio - metric technology are present. As compare to them RFID is faster than barcode and smart card system and cheaper than bio - metric system, Hence we preferred to the RFI D for our Project. Our project is Smart Attendance System using RFID. RFID stands for Radio Frequency Identification and Detection. In this we are using RFID reader and passive RFID chips. Reader is located on fixed location sends signal to passive RFID ch ip detected in range of reader. Chip re - transmits the acknowledgement signal with its unique Identifier code, hence chip is identified. Also, a single reader can identify many no of chips in very short period of time. So, we are using these properties of R FID reader and tag to monitor the students

    Sigmoid volvulus in pregnancy: a rare case

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    Sigmoid volvulus in pregnancy is an extremely uncommon condition, with only 84 cases to have been reported in the English literature. Sigmoid volvulus is the most common cause of bowel obstruction complicating pregnancy, accounting for up to 44 per cent of cases. Overall bowel obstruction in pregnancy varies from 1 in 1500 to 1 in 66,431 deliveries. Intestinal obstruction in pregnancy can be caused by many factors including congenital or postoperative adhesions, volvulus, intussusceptions, hernia and appendicitis, history of intestinal tuberculosis. Patient presented with acute onset abdominal distension associated with multiple episodes of vomiting. When history and clinical examination was suggestive of acute abdomen, diagnosis was confirmed with imaging modalities like abdominal ultrasound, CT (Computerized tomography) scan. Sigmoid volvulus is a surgical emergency and is to be treated promptly. Here we presented a case report on sigmoid volvulus in third trimester pregnancy which was managed by emergency exploration

    A Novel Technique of Uterine Manipulation in Laparoscopic Pelvic Oncosurgical Procedures: “The Uterine Hitch Technique”

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    Aim. To describe a new technique of uterine manipulation in laparoscopic management of pelvic cancers. Material and Methods. We used a novel uterine hitch technique in 23 patients from May 2008 to October 2008. These patients underwent pelvic oncologic surgery including laparoscopic radical hysterectomy (n = 7), laparoscopic anterior resection (n = 4), laparoscopic abdominoperineal resection (n = 3), laparoscopic posterior exenteration (n = 4), or laparoscopic anterior exenteration (n = 5). The uterus was hitched to the anterior abdominal.wall by either a single suture in the fundus or by sutures through the round ligaments. Results. The uterine hitch technique was successfully accomplished in all procedures. It was performed in less than 5 minutes in all cases. It obviated the need for vaginal manipulation. An extra port for retraction could be avoided. There were no intraoperative complications. Conclusion. A practical, cheap and reproducible method for uterine manipulation, during pelvic oncologic surgery is described. It improves the stability of the uterus and also obviates the need for keeping an additional assistant for vaginal manipulation in any of the procedures

    Pregnancy in rudimentary horn of unicornuate uterus: a rare case

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    Congenital malformations of the female genital tract result from embryological maldevelopment of Mullerian or paramesonephric ducts. Mullerian duct anomalies (MDAs) are due to agenesis, defective fusion or resorption during embryological development. Unicornuate uterus results due to defective lateral fusion of Mullerian duct. This report discussed a case of pregnancy in rudimentary horn of unicornuate uterus which resulted in rupture of the horn. A patient 35 year old G2A1 with spontaneous conception with 4 months pregnancy came to emergency room with complaints of pain in abdomen and giddiness. On examination her general condition was moderate with pulse rate of 128 bpm, blood pressure of 90/60 mmHg, pallor was present. On per abdomen examination guarding, rigidity and diffuse tenderness was present. On per vaginum examination, uterus size could not be appreciated. Her haemoglobin level was 6 gm%. Ultrasonography of abdomen showed presence of unicornuate uterus with ruptured right horn with fetus in the abdominal cavity and presence of hemoperitoneum. Immediate resuscitative measures were performed, blood transfusion was started and simultaneously patient was shifted to operation theatre for exploratory laparotomy. Intraoperatively hemoperitoneum with unicornuate uterus with non communicating ruptured accessory horn on right side was present and foetus in peritoneal cavity was seen. Ruptured horn was excised and uterus was repaired. The accessory horn and foetus were sent for histopathology examination which was suggestive of placenta increta with gestational hypertrophy and hyperplasia of myometrium with normal tube and ovary. Patient tolerated the procedure well

    Effect of physiotherapy on single breath count and breath holding time in COVID-19 patients

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    Background: The novel Coronavirus is known to primarily affect the respiratory system and physiotherapy treatment is integral to combat this infection. However, the assessment of pulmonary function poses a difficult challenge considering the risk of spread of infection and sanitisation of the devices used. Single breath count (SBC) and breath holding time (BHT) can be thus adopted as bedside assessment tests for pulmonary function following physiotherapy treatment.Method: In this a retrospective observational study of 51 COVID-19 patients, mean age 51.7±14.56 years, on room air, admitted in the step-down units of a tertiary care hospital. Patients received standard physiotherapy treatment, within safe hemodynamic limits. Pre and post treatment session SBC was recorded in 32 patients and BHT in 19 patients. Three reading were noted and the best of three readings were used for analysis.Results: The paired t test was used to analyse SBC and BHT. Mean pre and post SBC was 18.25±8.96 and 23.31±9.96 respectively with a mean difference of 5.06 and p<0.0001. Mean pre and post BHT were 19.37 and 23.05 seconds respectively with a mean difference of 3.68 and p<0.0001.  Statistically significant difference in the pre and post treatment session SBC and BHT was observed, indicating a positive effect of physiotherapy treatment on pulmonary function.Conclusion: Physiotherapy treatment shows significant improvement in the pulmonary function in COVID-19 patients. SBC and BHT tests can be used as assessment and prognostic tools for pulmonary function in COVID-19 patients

    Kinetically Decoupled Electrical and Structural Phase Transitions in VO2

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    Vanadium dioxide (VO2) has drawn significant attention for its near room temperature insulator to metal transition and associated structural phase transition. The underlying Physics behind the temperature induced insulator to metal and concomitant structural phase transition in VO2 is yet to be fully understood. We have investigated the kinetics of the above phase transition behaviors of VO2 with the help of resistivity measurements and Raman spectroscopy. Resistance thermal hysteresis scaling and relaxation measurements across the temperature induced insulator to metal transition reveal the unusual behaviour of this first-order phase transition, whereas Raman relaxation measurements show that the temperature induced structural phase transition in VO2 follows usual behaviour and is consistent with mean field prediction. At higher temperature sweeping rates decoupling of insulator to metal transition and structural phase transition have been confirmed. The observed anomalous first order phase transition behavior in VO2 is attributed to the unconventional quasi particle dynamics, i.e. significantly lowered electronic thermal conductivity across insulator to metal transition, which is confirmed by ultrafast optical pump-probe time domain thermoreflectance measurements.Comment: 25 pages, 8 figure

    Author Correction: Increased lactate dehydrogenase activity is dispensable in squamous carcinoma cells of origin.

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    The original version of this Article contained an error in the spelling of the authors J. H. Joly and N. A. Graham, which were incorrectly given as J. Jolly and N. Graham. Additionally, the affiliation of both authors with 'Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089' and N. A. Graham with 'Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90089' was inadvertently omitted. This has now been corrected in both the PDF and HTML versions of the Article
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