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

Optimization of 6-Gingerol Extraction Assisted by Microwave From Fresh Ginger Using Response Surface Methodology

The present study investigates optimum conditions for Microwave assisted extraction (MAE) of 6-gingerol. Ginger was dried using a cross flow dryer at 55 ± 2 0C for eight hours. Ginger powder was extracted at three different watts (400 W, 500 W, and 600 W), temperatures (50 0C, 60 0C, 70 0C) and time (10, 20, 30 min) for optimum yield.  6-gingerol content was found to be 21.15 ± 0.13 and 18.81 ± 0.15 mg/g in fresh ginger and dried ginger, respectively.  Optimized condition obtained by RSM for 6-gingerol was 400 W, 70 0C at 10 min extraction time.  The results of MAE are expressed by 2-D contour plot and response surface curve by keeping one variable constant which showed highest yield at 600 W, 70 0C for 30 min extraction time.  Microwave assisted extracts exhibited higher antioxidant activity in comparison with conventional extracts

Analysis and Optimization of Machining Process Parameters Using Design of Experiments

In any machining process, apart from obtaining the accurate dimensions, achieving a good surface quality and maximized metal removal are also of utmost importance. A machining process involves many process parameters which directly or indirectly influence the surface roughness and metal removal rate of the product in common. Surface roughness and metal removal in turning process are varied due to various parameters of which feed, speed, depth of cut are important ones. A precise knowledge of these optimum parameters would facilitate reduce the machining costs and improve product quality. Extensive study has been conducted in the past to optimize the process parameters in any machining process to have the best product. Current investigation on turning process is a Response Surface Methodology applied on the most effective process parameters i.e. feed, cutting speed and depth of cut while machining Aluminium alloy and resin as the two types of work pieces with HSS cutting tool. The main effects (independent parameters), quadratic effects (square of the independent variables), and interaction effects of the variables have been considered separately to build best subset of the model. Three levels of the feed, three levels of speed, three values of the depth of cut, two different types of work materials have been used to generate a total 20 readings in a single set. After having the data from the experiments, the performance measures surface roughness (Ra) of the test samples was taken on a profilometer and MRR is calculated using the existing formulae. To analyze the data set, statistical tool DESIGN EXPERT-8 (Software) has been used to reduce the manipulation and help to arrive at proper improvement plan of the Manufacturing process & Techniques. Hypothesis testing was also done to check the goodness of fit of the data. A comparison between the observed and predicted data was made, which shows a close relationship. Key words: Surface Roughness and Metal Removal Rate, Turning, Response Surface    Methodology, Aluminium Alloy, Resin.

Development and Evaluation of Palmyrah (Borassus Flabellifer L.) Fruit Pulp

Palmyrah(Borassus flabellifer L) fruit pulp is available abundantly and has high potential for food in rural areas, useful for pharmaceutical and cosmetic applications, however, the main hindrance for these pulp is lack of mechanisation and availability of pulp in sufficient quantity at one place. The pulp of this fruit is usually used by rural communities where the processors use manual pulping, which are not only time-consuming but yields seasonal during July and August in India. Therefore, the objective of this work was to develop and evaluate the efficiency of fruit pulp extractor. The pulper was developed to be compact and easy to operate, consisting of main housing with stainless steel teeth on rotating shaft and pulping performed by beating and shearing. The performance evaluation of the machine was carried out with different rpm (320, 360, 410) input capacity(8,10 and 12 kg) for fixed time of operation is 6 minutes.. The pulp weight was evaluated during the pulping process period. The highest pulping efficiency (84.78%) and pulp recovery (33.9%) was obtained rpm of 410, with 6 minutes of pulping, and batch capacity of 10 kg of fruits which resulted in a capacity of 50 kg fruits per hour. This high efficiency makes this mechanized effective for pulping palmyrah fruits and, thus, it can replace manual pulping, especially in rural communities involved with the palmyrah fruit pulping. &nbsp

Correlation of clinical and radiological outcome of distal radius fractures treated with volar plating

Background: Distal radius fractures are one of the most common injuries treated by an orthopaedic surgeon, accounting for approximately one sixth of all fractures. Due to increase in incidence of high velocity trauma, the injury is seen occurring in young patients more often. A displaced fracture deranges the wrist anatomy causing deformity and loss of function at the wrist joint. Open reduction and internal fixation with plate using a volar approach allows anatomical reduction of the fracture, stable fixation aiding in early mobilization.Methods: Our study was a hospital-based study conducted during the period June 2016 to November 2018. A total of 30 patients with distal radius fracture were treated with ORIF with a volar plate. They were followed up for a year and clinical and radiological outcomes were evaluated.Results: Among the 30 patients studied 25 were males and 5 were females with mean age of 36.23 years. According to Gartland and Werley demerit scoring system, 15 of them had excellent result at the end of one year. 13 Of them had good and 2 of them had fair results. Radiological assessment was done by Sarmiento’s modification of the Lind storm criteria and 15 of them had excellent results. 15 patients had good radiological outcome.Conclusions: From this study we conclude that ORIF with volar plating can provide good clinical and functional outcome in distal radius fractures. Anatomical reduction of the fracture fragments is the key in achieving good results

Orientational distribution function in nematic liquid crystals by x-rays: Fourier method

The existing methods for the determination of the orientational distribution function f(beta) in the nematic liquid crystals using X-rays have been reviewed. A simple Fourier method which gives f(beta) in terms of the measured intensity is analysed. Using this distribution function, the accuracy with which the order parameters could be evaluated is discussed and the results show the elegance of the Fourier method used here

Human XPC-hHR23B interacts with XPA-RPA in the recognition of triplex-directed psoralen DNA interstrand crosslinks

DNA interstrand crosslinks (ICLs) represent a severe form of damage that blocks DNA metabolic processes and can lead to cell death or carcinogenesis. The repair of DNA ICLs in mammals is not well characterized. We have reported previously that a key protein complex of nucleotide excision repair (NER), XPA-RPA, recognizes DNA ICLs. We now report the use of triplex technology to direct a site-specific psoralen ICL to a target DNA substrate to determine whether the human global genome NER damage recognition complex, XPC-hHR23B, recognizes this lesion. Our results demonstrate that XPC-hHR23B recognizes psoralen ICLs, which have a structure fundamentally different from other lesions that XPC-hHR23B is known to bind, with high affinity and specificity. XPC-hHR23B and XPA-RPA protein complexes were also observed to bind psoralen ICLs simultaneously, demonstrating not only that psoralen ICLs are recognized by XPC-hHR23B alone, but also that XPA-RPA may interact cooperatively with XPC-hHR23B on damaged DNA, forming a multimeric complex. Since XPC-hHR23B and XPA-RPA participate in the recognition and verification of DNA damage, these results support the hypothesis that interplay between components of the global genome repair sub-pathway of NER is critical for the recognition of psoralen DNA ICLs in the mammalian genome

Hysterosalpingographic findings in infertile women diagnosed with genital tuberculosis

Background: Objectives of the study were to describe the hysterosalpingographic (HSG) findings among infertile women with genital tuberculosis (GTB).Methods: This is a retrospective analytical study conducted at Sri Muthu Kumaran Medical College Hospital and Research Institute, Chennai, from January 2016 to January 2020. Study population included 51 infertile women with genital tuberculosis. GTB was diagnosed by either culture/histopathological examination (HPE) or polymerase chain reaction (PCR) studies. In these proved cases of tuberculosis, HSG findings were analysed. Permission from the institutional review board was obtained for the retrospective analysis of the hospital data.Results: Among 113 women who underwent hysterosalpingography, 51 were diagnosed with GTB. In these 51 women, the HSG finding were normal in 23.5% and were abnormal in 76.5% of cases. The abnormal HSG findings noted in association with GTB were calcification (3.9%) , distorted uterine cavity (3.9%), beaded tubes, intravasation with blocked tubes (5.9%), fimbrial block with hydrosalpinx (15.6%), cornual block (35.3%) and mid tubal block.Conclusions: Though imaging findings may be highly suggestive of tuberculosis, some of the features such as tubal block and hydrosalpinx are not specific for tuberculosis and may be seen in other infective causes of tubal damage also. Therefore, specific investigations for tuberculosis are still required to make a de­finite diagnosis. The presence of HSG features indicate that considerable tubal damage has occurred