A transmission electron microscopy study of defect generation and microstructure development in ultrasonic wire bonding

Ultrasonic wire bonding is widely used in the electronic industry to connect semiconductor chips to packages. Even though the popularity of the technique has increased in recent times, questions remain about the bonding mechanism, and factors affecting bondability and reliability. In this thesis, answers were provided to many of these questions using TEM to examine bonded cross section and plan view specimens. A detailed investigation of the Al wire and substrate showed dynamically annealed well recovered grains while microstructural observations of other substrates revealed wide varieties of response mechanisms. For example, Ni formed a dislocation cell structure, Cu formed a partially recovered structure, while Cu alloys and stainless steel formed planar dislocation arrays. These observed transformations were correlated with basic material properties and literature reported cyclic deformation studies to determine factors contributing to substrate plastic deformation during bonding. It appeared that the plastic deformation of the substrate is not a requirement for good bonding, but since extensive plastic deformation can occur during bonding, it could have important implications in bond strength and reliability. A model developed to estimate microstructural transformations was effective when applied to different metal substrates but somewhat less effective with Cu alloys. The extent and type of intermetallic phases that formed at the wire-substrate interface after thermal aging, thermal cycling and in the as-bonded conditions were characterized for different Au and NiB plated substrates using EDS. Specimens were also examined for the extent of Kirkendall porosity and the conditions of the unreacted portions of the wire and substrate. It was found that the extent of interfacial reactions depended strongly on substrate metallurgy. For example, in the NiP/immersion Au specimen the original Au layer was still present after bonding, and transformed completely to Al-Au intermetallics after only 1.5 h at 90\sp\circC. The same treatment resulted in no intermetallic phase formation for Ni-B specimens with the interface remaining chemically and structurally sharp. Finally, mechanisms of bonding and microstructural development were proposed

Transcending the Digital Divide: Paving Itinerary for Conducive Digital Economy

In recent years, due to dynamic evolution of information and communication technologies (ICTs) and the increasing importance of ICT diffusion in the process of economic growth, there exists the need for a broad and systematic comparison of the ICT framework development of countries around the globe. The Information Age that is upon us holds out the promise of a new world of shared prosperity, a global renaissance. At the same time, it also holds out the danger of economic exploitation, societal devastation and a new era of imperialism and colonialism. It can be spurned if we can bridge the economic and development gap, the information and knowledge gap and the great divide within. A key element to extending the information revolution is identification, development and utilization of information assets. Information and knowledge is the new fuel of the economy. In this information economy, economic development means harnessing the information and knowledge assets of a community to help local businesses succeed in the new environment

Prevalence of haptic feedback in robot-mediated surgery : a systematic review of literature

© 2017 Springer-Verlag. This is a post-peer-review, pre-copyedit version of an article published in Journal of Robotic Surgery. The final authenticated version is available online at: https://doi.org/10.1007/s11701-017-0763-4With the successful uptake and inclusion of robotic systems in minimally invasive surgery and with the increasing application of robotic surgery (RS) in numerous surgical specialities worldwide, there is now a need to develop and enhance the technology further. One such improvement is the implementation and amalgamation of haptic feedback technology into RS which will permit the operating surgeon on the console to receive haptic information on the type of tissue being operated on. The main advantage of using this is to allow the operating surgeon to feel and control the amount of force applied to different tissues during surgery thus minimising the risk of tissue damage due to both the direct and indirect effects of excessive tissue force or tension being applied during RS. We performed a two-rater systematic review to identify the latest developments and potential avenues of improving technology in the application and implementation of haptic feedback technology to the operating surgeon on the console during RS. This review provides a summary of technological enhancements in RS, considering different stages of work, from proof of concept to cadaver tissue testing, surgery in animals, and finally real implementation in surgical practice. We identify that at the time of this review, while there is a unanimous agreement regarding need for haptic and tactile feedback, there are no solutions or products available that address this need. There is a scope and need for new developments in haptic augmentation for robot-mediated surgery with the aim of improving patient care and robotic surgical technology further.Peer reviewe

Learning curve of laparoscopic hysterectomy in a zonal hospital setting: a retrospective analysis of 102 cases operated by a single surgeon

Background: The aim of this study was to analyse the learning curve and clinical efficacy of the art of laparoscopic hysterectomy in a zonal hospital setting.Methods: We conducted a retrospective analysis of 102 women who underwent laparoscopic hysterectomy (LAVH/ TLH) by a single surgeon after post-graduation for benign uterine pathology in a zonal hospital setting. They were divided into two groups of first 50 cases (Group I) and next 52 cases (Group II). The primary outcome was the learning curve of the operating gynaecologist in terms of reduction in duration of surgery, reduced perioperative complications, increasing percentage of TLHs with time.Results: 102 women underwent laparoscopic hysterectomy for the benign uterine pathology successfully. Surgical outcomes of laparoscopic hysterectomy in terms of mean operative time was 135 mins (Group I) vs 93 mins (Group II), estimated blood loss 255 ml (Group I) vs 140 ml (Group II), hospital stay 05 days (Group I) vs 03 days (Group II), duration of postoperative analgesia 07 days (Group I) vs 05 days (Group II). As the surgical experience increased, patients with bigger uterine size (>10-week size) were taken up for hysterectomy, percentage of TLH increased in Group II as compared to Group I (42.31% vs 18%), with decreasing complications and shorter recovery time.Conclusions: Laparoscopic hysterectomy (LAVH/ TLH) has a short learning curve and it's a feasible and beneficial surgical modality for treating benign uterine pathology even in a zonal hospital setting (low resource setting)

Statistical Analysis of Twin Populations using Dissimilarity Measurements in Hippocampus Shape Space

By analyzing interpoint comparisons, we obtain significant results describing the relationship in “hippocampus shape space” of clinically depressed, high-risk, and control populations. In particular, our analysis demonstrates that the high-risk population is closer in shape space to the control population than to the clinically depressed population

Covid-19 and Tobacco Cessation:Lessons from India

OBJECTIVES: The Government of India prohibited the sale of tobacco products during the COVID-19 lockdown to prevent spread of the SARS-CoV-2 virus. This study assessed the tobacco cessation behaviour and its predictors among adult tobacco users during the initial COVID-19 lockdown period in India. STUDY DESIGN: : Cross-sectional study. METHODS: A cross-sectional study was conducted with 801 adult tobacco users (both smoking and smokeless tobacco) in two urban metropolitan cities of India over a 2-month period (July–August 2020). The study assessed complete tobacco cessation and quit attempts during the lockdown period. Logistic and negative binomial regression models were used to study correlates of tobacco cessation and quit attempts, respectively. RESULTS: In total, 90 (11.3%) tobacco users reported that they had quit using tobacco after the COVID-19 lockdown period. Overall, a median of two quit attempts (interquartile range [IQR] 0–6) were made by tobacco users. Participants with good knowledge on the harmful effects of tobacco use and COVID-19 were significantly more likely to quit tobacco use (odds ratio [OR] 2.2; 95% confidence interval [CI] 1.2–4.0) and reported more quit attempts (incidence risk ratio [IRR] 5.7; 95% CI 2.8-11.8] compared with those with poor knowledge. Participants who had access to tobacco products were less likely to quit tobacco use compared with those who had no access (OR 0.3; 95% CI 0.2–0.5]. CONCLUSIONS: Access restrictions and correct knowledge on the harmful effects of tobacco use and COVID-19 can play an important role in creating a conducive environment for tobacco cessation among users

Cu/Pd Bimetallic Supported on Mesoporous TiO2 for Suzuki Coupling Reaction

Generally bimetallic catalysts are more superior to monometallic catalysts and provide a better platform for the development of novel catalysts with enhanced activity, selectivity, and stability. In the current work we have prepared Cu/Pd bimetallic supported on mesoporous TiO2 by hydrothermal method. The prepared system was characterized by various physico-chemical techniques such as XRD, TG-DTG, SEM, EDAX, BJH isotherm, and XPS. Thermal stability and complete electronic structure were identified from TG and XPS measurements respectively. The bimetallic system was found to be very active in Suzuki cross-coupling reaction using different substrates. The products were separated and purified by column chromatography and the resultant products were characterized thoroughly by 1H NMR, and FT-IR analysis.

Early detection of chronic kidney disease in low-income and middle-income countries: development and validation of a point-of-care screening strategy for India.

INTRODUCTION: Although deaths due to chronic kidney disease (CKD) have doubled over the past two decades, few data exist to inform screening strategies for early detection of CKD in low-income and middle-income countries. METHODS: Using data from three population-based surveys in India, we developed a prediction model to identify a target population that could benefit from further CKD testing, after an initial screening implemented during home health visits. Using data from one urban survey (n=8698), we applied stepwise logistic regression to test three models: one comprised of demographics, self-reported medical history, anthropometry and point-of-care (urine dipstick or capillary glucose) tests; one with demographics and self-reported medical history and one with anthropometry and point-of-care tests. The 'gold-standard' definition of CKD was an estimated glomerular filtration rate <60 mL/min/1.73 m2 or urine albumin-to-creatinine ratio ≥30 mg/g. Models were internally validated via bootstrap. The most parsimonious model with comparable performance was externally validated on distinct urban (n=5365) and rural (n=6173) Indian cohorts. RESULTS: A model with age, sex, waist circumference, body mass index and urine dipstick had a c-statistic of 0.76 (95% CI 0.75 to 0.78) for predicting need for further CKD testing, with external validation c-statistics of 0.74 and 0.70 in the urban and rural cohorts, respectively. At a probability cut-point of 0.09, sensitivity was 71% (95% CI 68% to 74%) and specificity was 70% (95% CI 69% to 71%). The model captured 71% of persons with CKD and 90% of persons at highest risk of complications from untreated CKD (ie, CKD stage 3A2 and above). CONCLUSION: A point-of-care CKD screening strategy using three simple measures can accurately identify high-risk persons who require confirmatory kidney function testing