Non-Destructive Evaluation—A Pivotal Technology for Qualification of Composite Aircraft Structures

Tremendous advances in composite materials and a deeper understanding of their behavior have been responsible for the increased use of composites in the development of advanced, new generation civil and military aircraft. Composites play an important role in any aircraft development programme and are strong contenders to their metal counterparts due to their significant contributions towards improving strength, stiffness, fatigue properties & weight reduction. As materials, structural design & processing have evolved, strong emphasis is placed on effective & reliable damage detection, durability and damage tolerance. As a consequence, Non-destructive Evaluation (NDE) has also undergone significant advances towards meeting the growing demands of quality assurance. Advanced Composites Division (ACD) of National Aerospace Laboratories (NAL), has been involved in the development of composite structures for both civil and military aircraft for over a decade and a half. Innovative composite processing methods like co-curing/co-bonding have been successfully employed to realize airworthy structures. The role of NDE in the development of these structures has been critical and not limited to damage detection alone. On several occasions, NDE has provided valuable inputs towards improving design and process parameters. In-spite of the complexity of the structures, stringent quality requirements and tight delivery schedules, NDE has been successful in certifying these composite structures for airworthiness. This paper discusses the implementation of key NDE techniques like ultrasonics, radiography, acoustic emission and thermography for reliable flaw detection, characterization and quality assurance of composite aircraft structures

C-reactive protein/albumin ratio as a predictor of 28 day mortality in patients with sepsis

Background: Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Sepsis remains a major cause of morbidity and mortality worldwide. Important biomarkers that can be used as prognostic markers in sepsis are C Reactive Protein (CRP) and serum Albumin levels. CRP levels markedly elevate in response to infection whereas albumin levels decrease in response to acute phase infection. We want to ascertain the value of CRP/albumin ratio as an independent predictor of 28-day mortality in sepsis patients.Methods: A prospective study was conducted including 150 patients satisfying the criteria for sepsis according to SOFA score of more than 2. Initial CRP/Albumin ratio was assessed to determine its significance in assessing the 28-day mortality, primary end point of our study. Secondary end points assessed were length of ICU stay, need for inotropic support, need for ventilator support and renal replacement therapy.Results: In the analysis of CRP/Albumin ratio as a predictor of 28-day mortality, patients were followed up from day of admission till 28 days to assess primary outcome. Among study subjects survivors were 92 in whom mean CRP/ALB ratio was 0.1197 and non survivors were 58 patients with mean CRP/ALB ratio was 0.0426. p-value <0.001, there was statistically significant difference found between survivor and Non-Survivor with respect to CRP/Albumin ratio. In assessing secondary outcome statistically significant association was found for need for ventilator and inotropic support, whereas it was insignificant in assessing need for dialysis and length of ICU stay.Conclusions: CRP/albumin ratio, which indicates the extent of residual inflammation, could be used as a prognostic marker in predicting mortality in patients with sepsis and septic shock

Prevalence and treatment patterns of dysmenorrhea among female medical students: a questionnaire based study at KIMS, Koppal

Background: Dysmenorrhea is a common gynaecological condition which causes physical pain, affects mental well-being and quality of life. The aim of the present study was to evaluate the prevalence, severity and the treatment patterns of primary dysmenorrhea among female medical students.Methods: The present study was a prospective, questionnaire based study conducted during March-April 2020 at KIMS, Koppal. The willing participants were given a time period of 30 minutes to fill the questionnaire.Results: Among the total of 211 female medical students, 180 students were suffering from dysmenorrhea. Almost 78.3% of those suffering from dysmenorrhea belonged to the age group of 19-21 years. Most of the students suffering from dysmenorrhea achieved menarche at the age of 13-14 years.  A majority (48.8%)  of the dysmenorrhic females had dysmenorrhea of mild degree. 73.8% of dysmenorrhic females did not seek any medical advice for the management of the symptoms of dysmenorrhea. 76 (42.2%) of the dysmenorrhic participant females missed their classes due to the symptoms of dysmenorrhea. The most favoured drug for the management of the symptoms of dysmenorrhea was the combination of mefenamic acid and dicyclomine (56.8%). 56.6% of the subjects utilized pharmacological measures, while the rest 43.3% utilized non-pharmacological measures for the relief from the symptoms of dysmenorrhea.Conclusions: The present study recognized that dysmenorrhea is a common menstrual disorder among young females. There should be an effort at mass education of the young females regarding the management of dysmenorrhea

Quality Assurance through Process Improvement - A Concise Review

The past two decades has seen the realization of the manufacturing firms towards quality consciousness. The various firms worldwide employed the statistical tools for minimizing the deviations and subsequently the number of rejects of the manufactured parts. In this process, more prominence is laid on prevention of defects rather than detecting and rejecting the defect in the usual traditional end inspection quality check. This review paper witnesses the procedures involved in the improvement of the manufacturing process capability and focuses on achieving quality assurance through sustained improvement in the manufacturing process. The different methodologies for sustained improvement in manufacturing process across varied industrial sectors, are identified, discussed and presented. The nuances of enhanced product quality levels through process capability improvement work performed in varied areas of industrial manufacturing are also captured

An end-to-end, interactive Deep Learning based Annotation system for cursive and print English handwritten text

With the surging inclination towards carrying out tasks on computational devices and digital mediums, any method that converts a task that was previously carried out manually, to a digitized version, is always welcome. Irrespective of the various documentation tasks that can be done online today, there are still many applications and domains where handwritten text is inevitable, which makes the digitization of handwritten documents a very essential task. Over the past decades, there has been extensive research on offline handwritten text recognition. In the recent past, most of these attempts have shifted to Machine learning and Deep learning based approaches. In order to design more complex and deeper networks, and ensure stellar performances, it is essential to have larger quantities of annotated data. Most of the databases present for offline handwritten text recognition today, have either been manually annotated or semi automatically annotated with a lot of manual involvement. These processes are very time consuming and prone to human errors. To tackle this problem, we present an innovative, complete end-to-end pipeline, that annotates offline handwritten manuscripts written in both print and cursive English, using Deep Learning and User Interaction techniques. This novel method, which involves an architectural combination of a detection system built upon a state-of-the-art text detection model, and a custom made Deep Learning model for the recognition system, is combined with an easy-to-use interactive interface, aiming to improve the accuracy of the detection, segmentation, serialization and recognition phases, in order to ensure high quality annotated data with minimal human interaction.Comment: 17 pages, 8 figures, 2 table

Design and Implementation of Novel High Performance Domino Logic

This dissertation presents design and implementation of novel high performance domino logic techniques with increased noise robustness and reduced leakages. The speed and overhead area became the primary parameters of choice for fabrication industry that led to invention of clocked logic styles named as Dynamic logic and Domino logic families. Most importantly, power consumption, noise immunity, speed of operation, area and cost are the predominant parameters for designing any kind of digital logic circuit technique with effective trade-off amongst these parameters depending on the situation and application of design. Because of its high speed and low overhead area domino logic became process of choice for designing of high speed application circuits. The concerning issues are large power consumption and high sensitivity towards noise. Hence, there is a need for designing new domino methodology to meet the requirements by overcoming above mentioned drawbacks which led to ample opportunities for diversified research in this field. Therefore, the outcome of research must be able to handle the primary design parameters efficiently. Besides this, the designed circuit must exhibit high degree of robustness towards noise.In this thesis, few domino logic circuit techniques are proposed to deal with noise and sub-threshold leakages. Effect of signal integrity issues on domino logic techniques is studied. Furthermore, having been subjected to process corner analysis and noise analysis, the overall performance of proposed domino techniques is found to be enhanced despite a few limitations that are mentioned in this work. Besides this, lector based domino and dynamic node stabilized techniques are also proposed and are investigated thoroughly. Simulations show that proposed circuits are showing superior performance. In addition to this, domino based Schmitt triggers with various hysteresis phenomena are designed and simulated. Pre-layout and post-layout simulation results are compared for proposed Schmitt trigger. Simulations reveal that proposed Schmitt trigger techniques are more noise tolerant than CMOS counterparts. Moreover, a test chip for domino based Schmitt trigger is done in UMC 180 nm technology for fabrication

Improved Techniques for High Performance Noise-Tolerant Domino CMOS Logic Circuits

Domino CMOS logic circuit family finds a wide variety of applications in microprocessors, digital signal processors, and dynamic memory due to their high speed and low device count. However, there are inevitable problems that degrade the noise immunity of this family; they are the inevitable leakage current and the charge sharing. Added to the drawbacks is the relatively large power consumption, especially if compared to the static complementary CMOS logic family. To make the matter worse, these drawbacks are more tactile with the scaling of CMOS technology. In my thesis, An introduction to domino logic, The impact of CMOS technology scaling on the performance of domino CMOS logic, Three Phase Domino Logic Circuit, High-performance noise-tolerant circuit techniques for CMOS dynamic logic and other Domino logic techniques are studied and corresponding Domino logic techniques have been designed and simulated. Specifically, the need to decrease the dynamic power consumption forces the designer to use a lower power-supply voltage. This in turn necessitates the reduction of threshold voltage to maintain the performance with the associated increase in sub threshold leakage current. So, a properly sized PMOS keeper must be used to compensate for this leakage. It will be found that the speed, which is the major advantage of domino logic compared to other logic styles, will degrade with CMOS technology scaling due to the contention current of the keeper. To assure high performance in noise tolerant techniques, the inevitable effects like leakage currents and charge distribution have to be minimized. In this thesis few modifications have also been made to already existing domino techniques and different Domino logic circuits are simulated in both Cadence virtuoso (implemented using GPDK090- library of 90nm technology) and Mentor graphics (implemented at different technologies like Tsmc 035.mod, Tsmc 025.mod, Tsmc 018.mod) environments. The performance parameters are also compared with other standard architectures of Domino logic