1,905 research outputs found
SHI induced nano track polymer filters and characterization
Swift heavy ion irradiation produces damage in polymers in the form of latent tracks. Latent
tracks can be enlarged by etching it in a suitable etchant and thus nuclear track etch membrane can be formed
for gas permeation / purification in particular for hydrogen where the molecular size is very small. By applying
suitable and controlled etching conditions well defined tracks can be formed for specific applications of the
membranes. After etching gas permeation method is used for characterizing the tracks. In the present work
polycarbonate (PC) of various thickness were irradiated with energetic ion beam at Inter University Accelerator
Centre (IUAC), New Delhi. Nuclear tracks were modified by etching the PC in 6N NaOH at 60 (±1) oC from both
sides for different times to produce track etch membranes. At critical etch time the etched pits from both the sides
meet a rapid increase in gas permeation was observed. Permeability of hydrogen and carbon dioxide has been
measured in samples etched for different times. The latent tracks produced by SHI irradiation in the track etch
membranes show enhancement of free volume of the polymer. Nano filters are separation devices for the
mixture of gases, different ions in the solution and isotopes and isobars separations. The polymer thin films with
controlled porosity finding it self as best choice. However, the permeability and selectivity of these polymer
based membrane filters are very important at the nano scale separation. The Swift Heavy Ion (SHI) induced
nuclear track etched polymeric films with controlled etching have been attempted and characterized as nano
scale filters.E-mail : [email protected] of Physics, University of Rajasthan,Jaipur-302 004, Indi
Synthesis of Al and Ag nanoparticles through ultra-sonic dissociation of thermal evaporation deposited thin films for promising clinical applications as polymer nanocomposite
Nanoparticles (NPs) having well-defined shape, size and clean surface serve as ideal model system to investigate surface/interfacial reactions. Ag and Al NPs are receiving great interest due to their wide applications in bio-medical field, aerospace and space technology as combustible additives in propellants and hydrogen generation. Hence, in this study, we have synthesized Ag and Al NPs using an innovative approach of ultra-sonic dissociation of thin films. Phase and particle size distributions of the Ag and Al NPs have been determined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Thin film dissociation/dissolution mechanism, hence conversion into NPs has been characterized by SEM- scanning electron microscope. EDXA & ICPMS have been performed for chemical analysis of NPs. Optical properties have been characterized by UV-Vis and PL spectroscopy. These NPs have also been investigated for their anti-bacterial activity against Escherichia coli bacteria. To the best of our knowledge, this is the first time when NPs has been synthesized by ultra-sonic dissociation of thin films. As an application, these NPs were used further for synthesis of nanocomposite polymer membranes, which show excellent activity against bio film formation
IVACS: Intelligent Voice Assistant for Coronavirus Disease (COVID-19) Self-Assessment
At the time of writing this paper, the world has around eleven million cases
of COVID-19, scientifically known as severe acute respiratory syndrome
corona-virus 2 (SARS-COV-2). One of the popular critical steps various health
organizations are advocating to prevent the spread of this contagious disease
is self-assessment of symptoms. Multiple organizations have already pioneered
mobile and web-based applications for self-assessment of COVID-19 to reduce
this global pandemic's spread. We propose an intelligent voice-based assistant
for COVID-19 self-assessment (IVACS). This interactive assistant has been built
to diagnose the symptoms related to COVID-19 using the guidelines provided by
the Centers for Disease Control and Prevention (CDC) and the World Health
Organization (WHO). The empirical testing of the application has been performed
with 22 human subjects, all volunteers, using the NASA Task Load Index (TLX),
and subjects performance accuracy has been measured. The results indicate that
the IVACS is beneficial to users. However, it still needs additional research
and development to promote its widespread application
Prognostic factors in primary adenocarcinoma of the small intestine: 13-year single institution experience
<p>Abstract</p> <p>Background</p> <p>Adenocarcinoma of the small bowel is a relatively rare malignancy as compared to the other malignancies of the gastrointestinal tract. Nonspecific presentation and infrequent occurrence often leads to a delay in diagnosis and consequent poor prognosis. Various other factors are of prognostic importance while managing these tumors.</p> <p>Methods</p> <p>The medical records of a total of 27 patients treated for adenocarcinoma of the small bowel at Providence Hospital and Medical Centers from year 1990 through 2003 were reviewed retrospectively. Data were analyzed using SPSS software (version 10.0; SPSS, Inc., Chicago, IL). Survival analyses were calculated using the Kaplan Meier method with the log rank test to assess the statistical significance. The socio-demographics (age, gender) were calculated using frequency analyses.</p> <p>Results</p> <p>The patients included nine males and eighteen females with a median age at diagnosis of 62 years. Only 48% of the patients had an accurate preoperative diagnosis while another 33% had a diagnosis suspicious of small bowel malignancy. None of the patients presented in stage 1. The cumulative five-year survival was 30% while the median survival was 3.3 years. There was no 30-day mortality in the postoperative period in our series.</p> <p>Conclusion</p> <p>The univariate analysis demonstrated that tumor grade, stage at presentation, lymph nodal metastasis and resection margins were significant predictors of survival.</p
Droplet microactuator system
The present invention relates to a droplet microactuator system. According to one embodiment, the droplet microactuator system includes: (a) a droplet microactuator configured to conduct droplet operations; (b) a magnetic field source arranged to immobilize magnetically responsive beads in a droplet during droplet operations; (c) a sensor configured in a sensing relationship with the droplet microactuator, such that the sensor is capable of sensing a signal from and/or a property of one or more droplets on the droplet microactuator; and (d) one or more processors electronically coupled to the droplet microactuator and programmed to control electrowetting-mediated droplet operations on the droplet actuator and process electronic signals from the sensor
Concurrent Development and Certification of SOFTCOMAG 49AA Alloy for Aeronautical Applications
Softcomag 49AA alloy consisting of 49 wt per cent Fe, 49 wt. per cent Co and 2 wt per cent V is a soft magnetic alloy with a combination of very high saturation magnetisation and high magnetostriction and used for several aeronautical applications such as generators (stators and rotors), fixed iron moving armature units etc. Though this alloy is brittle in nature, it can be formed into hot rolled bars and cold rolled sheets by adopting suitable thermo mechanical treatments. In order to indigenise and subsequent type certification for aeronautical applications, the alloy was produced using 100 per cent virgin raw materials in a vacuum induction melting (VIM) furnace which not only ensures substantial reduction of inclusions, but also the production of homogeneous alloy as a result of induction stirring. The chemical composition was examined and hot working parameters of the alloy were so optimised that they would result in the best combination of magnetic, physical and mechanical properties for the end use, which forms the central theme behind the developmental activity that was simultaneously covered by a comprehensive certification process. The material thus produced is subjected to stringent quality control checks in accordance with stipulated airworthiness norms. The paper discusses in detail the indigenisation efforts and airworthiness certification of the alloy Softcomag 49AA and its comparison with equivalent grades, namely PERMENDUR 49 and VACOFLUX 50.Defence Science Journal, 2012, 62(1), pp.67-72, DOI:http://dx.doi.org/10.14429/dsj.62.1093
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