Effects of variable resistance on smart structures of cubic reconnaissance satellites in various thermal and frequency shocking conditions

Piezoelectric materials are widely used as smart structures in cubic reconnaissance satellites because of their sensing, actuating, and energy-harvesting abilities. In this study, an analytical model is developed in specific mechanical thermal shocking conditions. A special circuit and apparatus is designed for experimentation on the basis of the inverse piezoelectric effect. An equivalent circuit method is used to establish the relationship between the resistance and peak-to-peak voltage of lead zirconate titanate used as smart materials for cubic reconnaissance satellites. Various frequencies and resistance were applied in different mechanical thermal shocking conditions. Moreover, numerical simulations are conducted in various mechanical loading conditions to determine the accumulative effect. The model provides a novel mechanism to characterize the smart structures in cubic reconnaissance satellites. A rise in temperature increases peak-to-peak voltage; a rise in frequency decreases peak-to-peak voltage; and intensified resistance decreases peak-to-peak voltage. Based on experimentation and simulation, the optimum resistance is predicted for the various frequencies and temperatures. The various conditions may correspond to the different applications of smart structures for cubic reconnaissance satellites. The analytical calculations are in good agreement with experimental and numerical calculations. © 2017, The Korean Society of Mechanical Engineers and Springer-Verlag GmbH Germany

Generation of electrical energy using lead zirconate titanate (PZT-5A) piezoelectric material: Analytical, numerical and experimental verifications

Energy harvesting is the process of attaining energy from the external sources and transforming it into usable electrical energy. An analytical model of piezoelectric energy harvester has been developed to determine the output voltage across an electrical circuit when it is forced to undergo a base excitation. This model gives an easy approach to design and investigate the behavior of piezoelectric material. Numerical simulations have been carried out to determine the effect of frequency and loading on a Lead zirconate titanate (PZT-5A) piezoelectric material. It has been observed that the output voltage from the harvester increases when loading increases whereas its resonance frequency decreases. The analytical results were found to be in good agreement with the experimental and numerical simulation results

Recent Developments in Distribution Theory: A Brief Survey and Some New Generalized Classes of distributions

The generalization of the classical distributions is an old practice and has been considered as precious as many other practical problems in statistics. These generalizations started with the introduction of the additional location, scale or shape parameters. In the last couple of years, this branch of statistics has received a great deal of attention and quite a few new generalized classes of distributions have been introduced. We present a brief survey of this branch and introduce several new families as well

Study of Infertility in Females by Laparoscopy in Remote Area

Background: To evaluate the role of laparoscopy in diagnosis and management of problems related to infertility. Methods: The descriptive study was conducted on 40 patients of infertility over a period of one year and nine months from April 2007 to December 2008. After complete history and examination, basic endocrinological investigations and semen analysis were done in infertile couple. Laparoscopy was done after pre - operative fitness under general anaesthesia. Results: The average age of women was 30 years . About one third of patients were brought within 5years , another third in 10 years and remaining third more than 10 years after marriage . 82.5% case were of primary infertility ,5% secondary infertility ,and 12.5% presented with primary amenorrhoea and infertility .Tubal block was one of the major causes of infertility . Adhesionolysis was done in 7.5%cases.ATTwas given on clinical grounds in 2.5% cases. Six patients conceived after treatment with healthy outcome. Conclusion: Infertile couple should be thoroughly investigated . Laparoscopy in infertility can be used for a definite diagnosis and treatment with good outcome

Odd Generalized N-H Generated Family of Distributions With Application to Exponential Model

A new family of distributions called the odd generalized N-H is introduced and studied. Four new special models are presented. Some mathematical properties of the odd generalized N-H family are studied. Explicit expressions for the moments, probability weighted, quantile function, mean deviation, order statistics and Rényi entropy are investigated. Characterizations based on the truncated moments, hazard function and conditional expectations are presented for the generated family. Parameter estimates of the family are obtained based on maximum likelihood procedure. Two real data sets are employed to show the usefulness of the new family

STUDY TO REVEAL THE EFFECTIVE WAY TO MANAGE THE ABDOMINAL WALL DEHISCENCE

Objective: To investigate an effective way to separate the abdominal wound dehiscence following emergency and elective laparotomies. Study Design: A comparative cross-sectional study. Place and Duration: In the Surgical Unit II of Holy Family Hospital, Rawalpindi for one year duration from July 2017 to July 2018. Materials and Methods: In the emergency or elective surgeries, 100 consecutive patients undergoing midline incision and laparotomy were included in the study. In order to see normal recovery, a wound examination was performed from the second postoperative day and the findings were recorded. Group A wound injuries were managed with full abdominal lavage and deep tension sutures and B group applied with Bogota bag application and abdominal wash. Results: Fifteen (11.5%) of the 130 patients developed full wound dehiscence (trapped abdomen). The incidence of abdominal rupture was significantly higher after emergency laparotomies (14/94, 14.89%), whereas one patient underwent elective laparotomy (1/36, 2.7%). Group A (n = 8) was managed with deep tension sutures and group B (n = 7) was treated with Bogota Bag. The results of deep tension sutures were associated with less morbidity, less surgery and lower mortality. Conclusion: Complete abdominal lavage with normal saline and closure with deep tension sutures is still an effective treatment in patients with complete wound dehiscence. Cases of abdominal closure due to a generalized intestinal edema or the need for further reoperation. Key words: Midline laparotomy, Abdominal wound dehiscence, Bogota bag, deep tension suture, burst abdomen

Outcome of ganglion impar block in chronic coccydynia

Background: Chronic coccydynia is an annoying condition and is characterized by pain in the tail bone. Most cases are treated conservatively initially but failed conservative management calls for interventions of various type. One of the interventions in the armamentarium of the orthopaedic surgeon is a ganglion impar block. The present study aimed at assessing the outcome of ganglion impar block in chronic coccydynia.    Methods: This prospective study of five years duration included 27 patients with chronic coccydynia with failed conservative treatment. Visual analogue score (VAS) and Oswestry disability index (ODI) were used to quantify pain and the improvement in symptoms. Minimum final follow-up was two years. Results: The mean VAS and ODI scores pre-injection were 5.98±1.86 and 52.13±2.13, respectively. The mean VAS and ODI scores at final follow-up were 2.47±1.65 and 23.59±2.34, respectively. The improvement in the above objective scores was found to be statistically significant with a p=0.00257 for VAS score and 0.00425 for ODI score. One patient developed syncope post-injection and one patient complained of superficial injection site pain which persisted for three weeks. No significant or major complication was encountered. Conclusions: Ganglion impar block appears to be a very impressive modality of treatment for chronic coccydynia in view of the simplicity, ease and reproducibility of the technique along with minimal complication rates. However, randomized control trials with large sample size are recommended

Results of Resection of Giant Pituitary Adenomas through Endoscopic Endonasal Approach

Background/Objective:  A minimally invasive surgical method is in use to create endoscopic transsphenoidal surgery. Because of the intricate dissection of the sellar region, surgical treatment of large pituitary adenomas is challenging. The study focused to determine the frequency of complications after endonasal endoscopic transsphenoidal resection of giant pituitary macroadenomas. Materials and Methods:  A descriptive case series study was conducted at the Neurosurgical Department of Lahore General Hospital, Lahore. A total of 70 patients fulfilling the selection criteria were enrolled. Major vascular injury was noted when there is an injury to the internal carotid artery or cavernous sinus. After discharge, patients were followed-up in OPD for 3 months. After 3 months, patients were evaluated for CSF leak and vision. The presence of complications was recorded. During surgery, operative time was noted. Results:  Mean age of patients was 55.7 ± 6.5 years. 45.71% of patients were male while the remaining 54.29% of patients were female Total of 41.43% of patients had disease < 2 years, whereas the duration of surgery was ? 3 hours in 64.3% of patients. A total 15.71% had complications which included diabetes insipidus (8.57%), infections (5.71%), pituitary dysfunction (4.29%), CSF leak (2.8%) and vascular injury (1.43%). The mortality rate was 1.43%. Conclusion:  The complication rate after endonasal endoscopic transsphenoidal resection of giant pituitary macroadenomas was high. Keywords:  Endonasal Endoscopic, Transsphenoidal Resection, Pituitary Macroadenomas, Complication

The role of augmentative and alternative communication in speech and language therapy: a mini review

Augmentative and Alternative Communication is an aided or unaided means of communication which supports existing communication abilities of an individual or replaces natural speech due to any speech and language disorder. The deficit could be developmental or acquired such as autism spectrum disorder, cerebral palsy, learning difficulties, dysarthria, dyspraxia or due to any acquired neurological condition such as aphasia and other degenerative disorders. Furthermore, it may be due to surgical procedures such as laryngectomy. Alternate means of communication have also been successfully used with COVID-19 patients. These tools may include pictures, symbols, signs or voice output devices. Parents of children with special needs and medical professionals have been reluctant in implementing the approach due to certain misconceptions. The aim of this review is to summarize the current evidence for the use of Augmentative and Alternative Communication with a range of disorders in relation to in relation to Pakistan