Scaling behavior in the convection-driven Brazil-nut effect

The Brazil-nut effect is the phenomenon in which a large intruder particle immersed in a vertically shaken bed of smaller particles rises to the top, even when it is much denser. The usual practice, while describing these experiments, has been to use the dimensionless acceleration \Gamma=a \omega^2/g, where a and \omega are respectively the amplitude and the angular frequency of vibration and g is the acceleration due to gravity. Considering a vibrated quasi-two-dimensional bed of mustard seeds, we show here that the peak-to-peak velocity of shaking v= a\omega, rather than \Gamma, is the relevant parameter in the regime where boundary-driven granular convection is the main driving mechanism. We find that the rise-time \tau of an intruder is described by the scaling law \tau ~ (v-v_c)^{-\alpha}, where v_c is identified as the critical vibration velocity for the onset of convective motion of the mustard seeds. This scaling form holds over a wide range of (a,\omega), diameter and density of the intruder.Comment: 4 pages, 5 figures + supplementary informatio

Matrix Transform Imager Architecture for On-Chip Low-Power Image Processing

Camera-on-a-chip systems have tried to include carefully chosen signal processing units for better functionality, performance and also to broaden the applications they can be used for. Image processing sensors have been possible due advances in CMOS active pixel sensors (APS) and neuromorphic focal plane imagers. Some of the advantages of these systems are compact size, high speed and parallelism, low power dissipation, and dense system integration. One can envision using these chips for portable and inexpensive video cameras on hand-held devices like personal digital assistants (PDA) or cell-phones In neuromorphic modeling of the retina it would be very nice to have processing capabilities at the focal plane while retaining the density of typical APS imager designs. Unfortunately, these two goals have been mostly incompatible. We introduce our MAtrix Transform Imager Architecture (MATIA) that uses analog floating--gate devices to make it possible to have computational imagers with high pixel densities. The core imager performs computations at the pixel plane, but still has a fill-factor of 46 percent - comparable to the high fill-factors of APS imagers. The processing is performed continuously on the image via programmable matrix operations that can operate on the entire image or blocks within the image. The resulting data-flow architecture can directly perform all kinds of block matrix image transforms. Since the imager operates in the subthreshold region and thus has low power consumption, this architecture can be used as a low-power front end for any system that utilizes these computations. Various compression algorithms (e.g. JPEG), that use block matrix transforms, can be implemented using this architecture. Since MATIA can be used for gradient computations, cheap image tracking devices can be implemented using this architecture. Other applications of this architecture can range from stand-alone universal transform imager systems to systems that can compute stereoscopic depth.Ph.D.Committee Chair: Hasler, Paul; Committee Member: David Anderson; Committee Member: DeWeerth, Steve; Committee Member: Jackson, Joel; Committee Member: Smith, Mar

Quantum change point and entanglement distillation

We study the quantum change point problem within the paradigm of local operations and classical communication (LOCC). Specifically, we consider a source that emits entangled pairs in a default state but undergoes mutation at some stage and begins producing an orthogonal entangled state. A sequence of entangled pairs prepared from such a source and shared between distant observers cannot be used for quantum information processing tasks as the identity of each entangled pair remains unknown. Assuming every point of a given sequence is equally likely to be the change point, including the possibility that no change occurs, we present a pretty-good LOCC protocol that identifies the change point and distills free entangled pairs. Next, we consider a variation of this problem where the source switches to an unknown entangled state that belongs to a known set. Here we show the local distinguishability of the collection of states, containing the default and all possible mutations, plays a crucial role: if they are locally distinguishable, the problem reduces to the previous one, but if not, one may still identify the mutated state, the change point, and distill entanglement, as we illustrate with a concrete example.Comment: 14 pages, 2 figure

Renal Tuberculosis Presenting as a Mass Lesion in a Two-year-old Girl : Report of a rare case

Genitourinary tuberculosis usually occurs in young adults and the middle-aged and is very uncommon in the paediatric population. It generally presents with haematuria, pyuria, irritative voiding symptoms and flank pain; presentation as a renal mass is highly unusual. We report a two-year-old girl who was referred to the Nil Ratan Sircar Medical College, Kolkata, India, in June 2014 with abdominal pain. Subsequent radiological investigations revealed a left renal hypoechoic mass lesion. A left nephroureterectomy was performed on suspicion of a Wilms’ tumour. Histopathology indicated an epithelioid granuloma with lymphocytic infiltration, suggestive of a tubercular aetiology. A Mantoux tuberculin skin test was positive; however, there was no evidence of tuberculosis detected elsewhere in the body and the source of the infection could not be identified. A diagnosis of renal tuberculosis was made and the child was treated with antitubercular drugs. The patient was asymptomatic at a six-month follow-up

Anesthetic Management of a Patient with Reactive Thrombocytosis due to Post-Trauma Splenectomy in a Patient Requiring Further Corrective Surgeries: A Case Report

Thrombocytosis poses hemostatic and bleeding risks, especially in the perioperative period and in the presence of other risk factors. There is no defined upper cut-off limit for platelet count for elective surgeries and ideal mode of anesthesia in these patients, especially in reactive thrombocytosis. A 22-year-old male will be described with thrombocytosis post-splenectomy after trauma and was scheduled to undergo an open reduction and internal fixation (ORIF) procedure for the shaft of a femur fracture. Hematology evaluation was sought and the decision to go ahead with the surgery was taken since the patient had no symptoms or signs of thrombosis or bleeding and the surgery was urgent which would help the patient to mobilize early and prevent further risk. Informed written risk consent was obtained from the patient about the risk of thromboembolism perioperatively. Perioperative measures for thromboprophylaxis were taken and the procedure was done uneventfully under spinal anesthesia. Postoperatively Hydroxyurea was started and after an uneventful hospital course, he was discharged and asked to follow up in the hematology outpatient department (OPD). There are conflicts on the use of neuraxial anesthesia in patients with thrombocytosis. The risk of bleeding and thrombosis is considerably less in reactive etiology and hence we decided to go ahead with spinal anesthesia. Also, none of the studies have defined the upper safe limit of platelet count that is to be accepted for elective surgeries. Further studies are needed in patients with thrombocytosis undergoing urgent or emergent surgeries where deferring surgeries for optimizing platelet count is not an option to understand the risks associated and the suitable method of anesthesia

ASSESSMENT OF LEAN BODY TISSUE COMPOSITION IN YOUNG ELITE MALE PLAYERS OF DIFFERENT SPORTS

Purpose: The present study was aimed to investigate the characteristics of lean body tissue composition in a group of young (mean age 16.7 ± 2.31 yrs) male athletes of different sports and the effect of sports specific physical activity on body tissue composition. Methods: Three hundred forty two (n= 342) male players of different sports viz., football, hockey, table tennis and badminton along with seventy two (n=72) sedentary school boys were also evaluated for various anthropometric and body composition parameters. Body composition including, body fat % (BF %), fat free mass (FFM), body cell mass (BCM) and extra cellular mass (ECM) was determined by whole body bio impedance measurements using a multi-frequency analyzer (Maltron Bioscan 920-2, Maltron International, Rayleigh, Essex, UK). Relative BCM, BCM Index (BCMI) and the ECM /BCM ratio were also calculated. Results: One-way ANOVA reveals significant differences (p<0.01) in BF%, FFM, BCM and ECM when compared among the group. BCM% related to body weight was also differed significantly (p<0.01) and found highest value in hockey players and lowest value in control group followed by the table tennis players. However, only significant difference was observed in case of BCMI when table tennis players were compared to their badminton counterparts. Scatter plot of BMI and BCMI predicted that both soccer and hockey players had greater lean mass variations whereas table tennis players exhibited lower lean mass variations. Conclusions: Differences in BCM, relative BCM, ECM/BCM, BCM/FFM and BCMI could be the potential indicators for the evaluation of qualitative and quantitative alterations in imposed training load of the athletes from different sports. The findings of present study may be useful to the players and their trainers to formulate the systematic training programme to enhance the sports performance.  Article visualizations

A preliminary report on newborn screening of inborn metabolic disorders

Background: Newborn screening (NBS) for metabolic and genetic disorders, which can be treated or modified if detected early in life, can help to prevent potentially disastrous consequences and save a precious life. However, there is no nationwide consensus on neonatal screening in India; hence, several treatable cases may be missed. Objective: The objective of this study was to detect the prevalence of selected metabolic disorders among neonates and to diagnose them as early as possible to minimize the morbidity and mortality. Materials and Methods: This prospective study included all live newborns delivered during period 2015–2016 in a tertiary care neonatal unit in Kolkata. On the 3rd day of life, newborns were subjected to detailed history, with special emphasis on family history and history of consanguinity. This was followed by thorough clinical examination and metabolic screening for congenital hypothyroidism (CH), G6PD deficiency, phenylketonuria (PKU), congenital adrenal hyperplasia (CAH), galactosemia, and cystic fibrosis with heel prick blood sample collected on blotting paper. Results: Of 1373 babies, four babies were screened positive of CH, G6PD deficiency, CAH, and PKU, respectively. However, confirmatory test for PKU came out to be negative. Conclusion: NBS can be an important preventive public health program. Application of tandem mass spectrometry to newborn screening for metabolic disorders offers rapid results and covers a wide range of disorders. However, the screen-positive tests need to be confirmed by actual enzyme assay (for deficiency), chromatography/mass spectroscopy analysis, or DNA testing

Allocation and Inventory Policies for Reels in Printed Circuit Board Assemblies

In Printed Circuit Board (PCB) assemblies, various types of reels loaded with different components are extensively utilized. We examine the inventory and allocation policies across assembly lines when the number and size of the reels substantially affect the assembly efficiency (e.g., when the number of available slots in a chip shooter is relatively limited). Critical features of the policies are illustrated via numerical examples

Multilayered and Chemiresistive Thin and Thick Film Gas Sensors for Air Quality Monitoring

Selective detection of gases such as nitrogen dioxide (NO2), carbon monoxide (CO), carbon dioxide (CO2), and various volatile organic components (VOCs) is necessary for air quality monitoring. Detection of hydrogen (H2) is equally important as it is a flammable gas and poses serious threat of explosion when exposed to oxygen gas. We have studied the sensing characteristics of these gases using thin film deposited by chemical solution deposition as well as relatively thicker films deposited by atmospheric plasma spray (APS) process. The chapter starts with the sensing mechanism of chemiresistive sensors followed by the definition of gas sensing parameters. Subsequently, we have demonstrated selective NO2 sensing characteristics of zinc oxide-graphene (ZnO-G) multilayered thin film followed by CO and H2 sensing characteristics of ZnO thin film and SnO2 thick film. Cross-sensitivity among CO and H2 gases has been addressed through the analysis of conductance transients with the determination of activation energy, Ea, and heat of adsorption, Q. The concepts of reversible and irreversible sensing have also been discussed in relation to CO and H2 gases. CO2 sensing characteristics of LaFe0.8Co0.2O3 (LFCO)-ZnO thin film have been elucidated. Interference from CO has been addressed with principal component analyses and the ascertaining of Ea and Q values. Additionally, the variation of response with temperature for each gas was simulated to determine distinct parameters for the individual gases. Further, VOC sensing characteristics of copper oxide (CuO) thin film and WO3-SnO2 thick film were investigated. Principal component analysis was performed to discriminate the gases in CuO thin film. The interaction of WO3-SnO2 thick film with various VOCs was found to obey the Freundlich adsorption isotherm based on which Ea and Q values were determined