95 research outputs found

    Remote preconditioning by aortic constriction: affords cardioprotection as classical or other remote ischemic preconditioning? Role of iNOS

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    Dose remote preconditioning by aortic constriction (RPAC) affords cardioprotection similar to classical or other remote ischemic preconditioning stimulus? Moreover study was also designed to investigate role of inducible nitric oxide synthase in remote preconditioning by aortic constriction. There are sufficient evidences that "ischemic preconditioning" has surgical applications and afford clinically relevant cardioprotection. Transient occlusion of circumflex artery, renal artery, limb artery or mesenteric artery preconditions the myocardium against ischemia reperfusion injury in case of ischemic heart disease leading to myocardial infraction. Here abdominal aorta was selected to produce RPAC. Four episodes of Ischemia-reperfusion of 5 min each to abdominal aorta produced RPAC by assessment of infract size, LDH and CK. These studies suggest RPAC produced acute (FWOP) and delayed (SWOP) cardioprotective effect. RPAC demonstrated a significant decrease in Ischemia-reperfusion induced release of LDH, CK and extent of myocardial infract size. L-NAME (10 mg/Kg i.v.), Aminoguanidine (150 mg/Kg s.c.), Aminoguanidine (300 mg/Kg s.c.), S-methyl isothiourea (3 mg/Kg i.v.), 1400W (1 mg/Kg i.v.) administered 10 min. before global ischemia reperfusion produced no marked effect. Aminoguanidine (150 mg/Kg s.c.), Aminoguanidine (300 mg/Kg s.c.), S-methyl isothiourea (3 mg/Kg i.v.), 1400W (1 mg/Kg i.v.) pretreatment after RPAC produced no significant effect on acute RPAC induced decrease in LDH, CK and infract size, whereas L-NAME (10 mg/Kg i.v.) increased RPAC induced decrease in LDH, CK and infract size. Most interesting observation is in delayed RPAC, where all NOS inhibitors pretreatment attenuate RPAC induced decrease in LDH, CK and infract size. In conclusions, "Remote preconditioning by aortic constriction" (RPAC) affords cardioprotection similar to classical or other remote ischemic preconditioning stimulus. Moreover, late or delayed phase of RPAC has been mediated by inducible nitric oxide synthase (iNOS) whereas it has not involved in acute RPAC

    Wind Energy Conversion System With Permanent Magnetic Synchronous Generator

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    This paper presents a study on grid-connected WECS with PMSG. The application of non-conventional energy resources develops much rapidly to improve low carbon energy resources in India. Nowadays, we are going to depend on solar, wind for the fulfillment of energy demand. Wind energy applications develop much more rapidly than other renewable resources such as solar, geothermal, and so on in the 21st century. It becomes the third core energy resource following non-conventional fuels as oil and chemical. The electrical energy generated by wind power plants is the best developing and most promising renewable energy source. The wind is a clean, free, and limitless energy source. Wind Energy Generation Systems (WECS) are confronted with increasing demands for power quality and harmonic distortion control. With the advance in power electronics technology, the fast growth of variable speed WECS is now witnessed

    Metal-organic frameworks-derived titanium dioxide-carbon nanocomposite for supercapacitor applications

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    The pyrolysis of metal-organic frameworks (MOFs) to derive porous nanocarbons and metal oxides has attracted scientific attention due to the advantageous properties of the final products (eg, high surface areas). In the present research, MIL-125 (MIL = Materials of Institute Lavoisier, a Ti-based MOF) has been subjected to a single-step pyrolysis treatment in argon atmosphere. The combination of uniformly linked titanium metal cluster and oxygen-enriched organic linker has acted as a template to yield a titanium dioxide (TiO2)-carbon nanocomposite. The TiO2 nanoparticles infused in carbon skeleton structure (TiO2/C) has been investigated as an electrode material for supercapacitor applications. TiO2/C electrodes have delivered an excellent electrochemical performance, for example, in terms of charging-discharging efficiency. Two equally weighed TiO2/C electrodes have been used to assemble a solid-state symmetrical supercapacitor (SC) device, containing a gel electrolyte (poly vinyl alcohol in 1 M H2SO4). The above device has delivered a high value of energy density (43.5 Wh/kg) and an excellent power output of 0.865 kW/kg. The symmetrical SC could retain almost 95% of its initial capacitance even after 2000 charging-discharging cycles. The electrochemical performance of the TiO2/C SC was better than most MOF-based SCs reported previously. Such performance is attributed to the synergistic combination of electrically conducting MOF-derived carbon and redox active TiO2 nanocrystals with a large specific surface area

    Inference of Resource Management Specifications

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    A resource leak occurs when a program fails to free some finite resource after it is no longer needed. Such leaks are a significant cause of real-world crashes and performance problems. Recent work proposed an approach to prevent resource leaks based on checking resource management specifications. A resource management specification expresses how the program allocates resources, passes them around, and releases them; it also tracks the ownership relationship between objects and resources, and aliasing relationships between objects. While this specify-and-verify approach has several advantages compared to prior techniques, the need to manually write annotations presents a significant barrier to its practical adoption. This paper presents a novel technique to automatically infer a resource management specification for a program, broadening the applicability of specify-and-check verification for resource leaks. Inference in this domain is challenging because resource management specifications differ significantly in nature from the types that most inference techniques target. Further, for practical effectiveness, we desire a technique that can infer the resource management specification intended by the developer, even in cases when the code does not fully adhere to that specification. We address these challenges through a set of inference rules carefully designed to capture real-world coding patterns, yielding an effective fixed-point-based inference algorithm. We have implemented our inference algorithm in two different systems, targeting programs written in Java and C#. In an experimental evaluation, our technique inferred 85.5% of the annotations that programmers had written manually for the benchmarks. Further, the verifier issued nearly the same rate of false alarms with the manually-written and automatically-inferred annotations

    Reusable, Instant and Private Payment Guarantees for Cryptocurrencies

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    Despite offering numerous advantages, public decentralized cryptocurrencies such as Bitcoin suffer from scalability issues such as high transaction latency and low throughput. The vast array of so-called Layer-2 solutions tackling the scalability problem focus on throughput, and consider latency as a secondary objective. However, in the context of retail payments, instant finality of transactions is arguably a more pressing concern, besides the overarching concern for privacy. In this paper, we provide an overlay network that allows privacy-friendly low latency payments in a retail market. Our approach follows that of a recent work called Snappy, which achieved low latency but exposed identities of customers and their transaction histories. Our construction ensures this data is kept private, while providing merchants with protection against double-spending attacks. Although our system is still based upon customers registering with a collateral, crucially this collateral is reusable over time. The technical novelty of our work comes from randomness-reusable threshold encryption (RRTE), a cryptographic primitive we designed specifically for the following features: our construction provably guarantees payments to merchants, preserves the secret identity of honest customers and prevents their transactions from being linked. We also present an implementation of our construction, showing its capacity for fast global payments in a retail setting with a delay of less than 1 second
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