Instability analysis and suppression of instability in low-density gas jets

A numerical study is conducted to understand the global instability of very low-density jets (as encountered in thermal plasmas). The simulations have been carried out for different parameters of density ratios, S = ƒÏj /ƒÏ‡ ranging from 0.5 to 0.03, different Reynolds numbers ranging from 500 to 4000 and different momentum thickness obtained by different extension tube length ranging from 3 to 6 diameter long. The flow parameters and vortex structures has been visualized to understand the details of the evolution of the flow field. The axisymmetric shear layer rolls up in the near field of the jet forming vortex rings. The rings merged, formed secondary mode of instability in the near field before they interacts with each other to form turbulence. Spectra results show that a global instability exists in the range of density ratios investigated. An envelope of the absolutely globally unstable region has been defined in a 3D space of Reynolds number, density ratio and momentum thickness space. A strategy for reducing the instability by altering the density profile of the surrounding gas stream is explored. Specifically, a ramp density profile or a step shape with an outward offset was explored, and it was observed that there was a reduction in the instability amplitude with the modified density profiles. Such a lowering in the instability fluctuations can be beneficial in stabilizing the thermal plasma behavior

Affinity Classification Problem by Stochastic Cellular Automata

This work introduces a new problem, named as, affinity classification problem which is a generalization of the density classification problem. To solve this problem, we introduce temporally stochastic cellular automata where two rules are stochastically applied in each step on all cells of the automata. Our model is defined on 2-dimensional grid having affection capability. We show that this model can be used in several applications like modeling self-healing systems

A Framework for Automated Correctness Checking of Biochemical Protocol Realizations on Digital Microfluidic Biochips

Recent advances in digital microfluidic (DMF) technologies offer a promising platform for a wide variety of biochemical applications, such as DNA analysis, automated drug discovery, and toxicity monitoring. For on-chip implementation of complex bioassays, automated synthesis tools have been developed to meet the design challenges. Currently, the synthesis tools pass through a number of complex design steps to realize a given biochemical protocol on a target DMF architecture. Thus, design errors can arise during the synthesis steps. Before deploying a DMF biochip on a safety critical system, it is necessary to ensure that the desired biochemical protocol has been correctly implemented, i.e., the synthesized output (actuation sequences for the biochip) is free from any design or realization errors. We propose a symbolic constraint-based analysis framework for checking the correctness of a synthesized biochemical protocol with respect to the original design specification. The verification scheme based on this framework can detect several post-synthesis fluidic violations and realization errors in 2D-array based or pin-constrained biochips as well as in cyberphysical systems. It further generates diagnostic feedback for error localization. We present experimental results on the polymerase chain reaction (PCR) and in-vitro multiplexed bioassays to demonstrate the proposed verification approach

Science with the Daksha High Energy Transients Mission

We present the science case for the proposed Daksha high energy transients mission. Daksha will comprise of two satellites covering the entire sky from 1~keV to $>1$~MeV. The primary objectives of the mission are to discover and characterize electromagnetic counterparts to gravitational wave source; and to study Gamma Ray Bursts (GRBs). Daksha is a versatile all-sky monitor that can address a wide variety of science cases. With its broadband spectral response, high sensitivity, and continuous all-sky coverage, it will discover fainter and rarer sources than any other existing or proposed mission. Daksha can make key strides in GRB research with polarization studies, prompt soft spectroscopy, and fine time-resolved spectral studies. Daksha will provide continuous monitoring of X-ray pulsars. It will detect magnetar outbursts and high energy counterparts to Fast Radio Bursts. Using Earth occultation to measure source fluxes, the two satellites together will obtain daily flux measurements of bright hard X-ray sources including active galactic nuclei, X-ray binaries, and slow transients like Novae. Correlation studies between the two satellites can be used to probe primordial black holes through lensing. Daksha will have a set of detectors continuously pointing towards the Sun, providing excellent hard X-ray monitoring data. Closer to home, the high sensitivity and time resolution of Daksha can be leveraged for the characterization of Terrestrial Gamma-ray Flashes.Comment: 19 pages, 7 figures. Submitted to ApJ. More details about the mission at https://www.dakshasat.in

Study of Clinicodemographic Profile of Adverse Cutaneous Drug Reactions in Indian Perspective

Background: Cutaneous adverse drug reactions are an important group of disorders which pose considerable amount of diagnostic and therapeutic challenges. The incidence of CADRs is estimated to be 1–2% in the general population. Newer insights have been developing in the field of factors affecting CADRs and the need for studies in the Indian population regarding the newer trends in cutaneous adverse effects. Materials and Methods: A prospective and observational study was conducted in the Department of Pharmacology and Collaboration with Department of Dermatology in MGM Medical College and LSK Hospital. All cases of suspected CADRs in patients with systemically administered drugs were actively screen by a senior dermatologist. Causality assessment was done by a Pharmacologist using WHO UMC scale. Only those cases where the causality was certain probable/likely were recorded. Results: This sampling comprised of 77 CADRs over a period of 1 year from June 2012 to May 2013. The clinical pattern and spectrum of CADRs were studied in 77 subjects. A wide clinical spectrum of CADRs ranging fixed drug eruptions to serious Stevens Johnson syndrome (SJS) was observed. The predominant pattern of reactions observed was fixed drug eruptions FDE (35.1%) followed by acneiform eruptions (23.4%), erythema multiforme (9.1%), and phototoxic drug reactions (7.8%). The antimicrobials causing FDE were macrolides, cephalosporins, and fluoroquinolones. Among the NSAIDs causing FDE, most were due to diclofenac (70%). CADRs were seen most commonly in the 31–40 (26%) years age group followed by 11–20 (24.7%) years and 41–50 (19.5%) years with mean age 32.09 years. Only 5.2% patients were more than 60 years, oldest being 67 years. Antimicrobials were the most common drug group incriminated in 34% patients followed by NSAIDs in 29% cases and steroids in 25% cases. Among NSAIDs, maximum number of CADRs were caused by ibuprofen (40.9%) followed by diclofenac (36.4%), paracetamol (9%), aceclofenac (9%), and nimesulide (4.5%). Serious reactions were infrequent. Conclusion: Most of the reactions were mild (53%) to moderate (42%) requiring no major medical intervention. However, a larger and multi-centric study needs to be conducted across the state to obtain more information about CADRs among the state population