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VLSI scaling methods and low power CMOS buffer circuit

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Journal of Semiconductors 2013年第9期34卷 92-99页

作者： vijay kumar sharma Manisha Pattanaik Department of Information Technology ABV-Indian Institute of Information Technology & Management

Device scaling is an important part of the very large scale integration （VLSI） design to boost up the success path of VLSI industry, which results in denser and faster integration of the devices. As technology node moves towards the very deep submicron region, leakage current and circuit reliability become the key issues. Both are increasing with the new technology generation and affecting the performance of the overall logic circuit. The VLSI designers must keep the balance in power dissipation and the circuit＇s performance with scaling of the devices. In this paper, different scaling methods are studied first. These scaling methods are used to identify the effects of those scaling methods on the power dissipation and propagation delay of the CMOS buffer circuit. For mitigating the power dissipation in scaled devices, we have proposed a reliable leakage reduction low power transmission gate （LPTG） approach and tested it on complementary metal oxide semiconductor （CMOS） buffer circuit. All simulation results are taken on HSPICE tool with Berkeley predictive technology model （BPTM） BSIM4 bulk CMOS files. The LPTG CMOS buffer reduces 95.16% power dissipation with 84.20% improvement in figure of merit at 32 nm technology node. Various process, voltage and temperature variations are analyzed for proving the robustness of the proposed approach. Leakage current uncertainty decreases from 0.91 to 0.43 in the CMOS buffer circuit that causes large circuit reliability.

关键词： LPTG buffer power dissipation propagation delay scaling nanoscale CMOS figure of merit

Improved thermoelectric property of cation-substituted CaMnO_3

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Chinese Physics B 2015年第9期24卷 542-547页

作者： Pradeep kumar Subhash C.Kashyap vijay kumar sharma H.C.Gupta Department of Physics Shyam Lal CollegeUniversity of Delhi Department of Physics Indian Institute of Technology Delhi

Single-phase pristine and cation-substituted calcium manganite（Ca1-xBixMn1-yVyO3-δ） polycrystalline samples were synthesized by the solid state reaction technique. Their thermoelectric properties were measured by a set up that was designed and assembled in the laboratory. The Ca1-x BixMn1-yVyO3-δsample with x = y = 0.04 has shown a power factor（S^2σ） of 176 μW/m/K^2 at 423 K, which is nearly two orders of magnitude higher than that of the pristine sample（2.1 μW/m/K2）. The power factor of the substituted oxide remains almost temperature independent as the Seebeck coefficient increases monotonically with temperature, along with the simultaneous decrease in electrical resistivity which is attributed to enhanced electron density due to co-doping of bismuth and vanadium and grain boundary scattering. These cation-substituted calcium manganites can be used as a potential candidate for an n-type leg in a thermoelectric generator（module）.

关键词： thermoelectric materials,solid state reaction,Seebeck coefficient,power factor

High-efficiency CdTe/CdS core/shell nanocrystals in water enabled by photo-induced colloidal hetero-epitaxy of CdS shelling at room temperature

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Nano Research 2015年第7期8卷 2317-2328页

作者： Hakimeh Zare Maziar Marandi Somayeh Fardindoost vijay kumar sharma Aydan Yeltik Omid Akhavan Hilmi Volkan Demir Nima Taghavinia Institute for Nanoscience and Nanotechnology Shafif University of Technology Tehran 14588 Iran Department of Physics Faculty of Sciences Arak University Arak 38156-8-8349 Iran Department of Physics Department of Electrical and Electronics Engineering and UNAM-Institute of Materials Science and Nanotechnology Bilkent University Ankara Turkey Luminous Center of Excellence for Semiconductor Lighting and Displays Microelectronics Division School of Electrical and Electronics Engineering and Physics and Applied Physics Division School of Physical and Mathematical Sciences Nanyang Technological University Singapore 639798 Singapore Physics Department ShafifUniversity of Technology Tehran 14588 Iran

We report high-efficiency CdTe/CdS core/shell nanocrystals synthesized in water by epitaxially growing CdS shells on aqueous CdTe cores at room temperature, enabled by the controlled release of S species under low-intensity ultraviolet （UV） light illumination. The resulting photo-induced dissociation of S2O2- ions conveniently triggers the formation of critical two-dimensional CdS epitaxy on the CdTe surface at room temperature, as opposed to initiating the growth of individual CdS core-only nanocrystals. This controlled colloidal hetero-epitaxy leads to a substantial increase in the photoluminescence （PL） quantum yield （QY） of the shelled nanocrystals in water （reaching 64%）. With a systematic set of studies, the maximum PL QY is found to be almost independent of the illuminating UV intensity, while the shell formation kinetics required for reaching the maximum QY linearly depends on the illuminating UV intensity. A stability study of the QD films in air at various temperatures shows highly improved thermal stability of the shelled QDs （up to 120 ℃ in ambient air）. These results indicate that the proposed aqueous CdTe/CdS core/shell nanocrystals hold great promise for applications requiring efficiency and stability.

关键词： CdTe/CDs,core/shell nanocrystal thermal stability photochemical

Cilostazol for secondary stroke prevention:systematic review and meta-analysis

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Stroke & Vascular Neurology 2021年第3期6卷 410-423,I0035-I0053页

作者： Choon Han Tan Andrew GR Wu Ching-Hui Sia Aloysius ST Leow Bernard PL Chan vijay kumar sharma Leonard LL Yeo Benjamin YQ Tan Department of Medicine Lee Kong Chian School of MedicineNanyang Technological UniversitySingapore Department of Medicine Yong Loo Lin School of MedicineNational University of SingaporeSingapore Department of Cardiology National University Heart CentreSingapore Division of Neurology Department of MedicineNational University Health SystemSingapore

Background Stroke is one of the leading causes of death worldwide.Cilostazol,an antiplatelet and phosphodiesterase 3 inhibitor,has not been clearly established for ischaemic stroke use.We aim to determine the efficacy and safety of cilostazol for secondary stroke prevention.Methods MEDLINE,EMBASE,Cochrane Library,Web of Science and ClinicalTrials.gov were searched from inception to 25 September 2020,for randomised trials comparing the efficacy and safety of cilostazol monotherapy or dual therapy with another antiplatelet regimen or placebo,in patients with ischaemic stroke.Version 2 of the Cochrane risk-of-bias tool for randomised trials(RoB 2)was used to assess study quality.This meta-analysis was reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)statement.Results Eighteen randomised trials comprising 11429 participants were included in this meta-analysis.Most trials possessed low risk of bias and were of low heterogeneity.Cilostazol significantly reduced the rate of ischaemic stroke recurrence(risk ratio,RR=0.69,95%CI 0.58 to 0.81),any stroke recurrence(RR=0.64,95%CI 0.54 to 0.74)and major adverse cardiovascular events(RR=0.67,95%CI 0.56 to 0.81).Cilostazol did not significantly decrease mortality(RR=0.90,95%CI 0.64 to 1.25)or increase the rate of good functional outcome(Modified Rankin Scale score of 0–1;RR=1.07,95%CI 0.95 to 1.19).Cilostazol demonstrated favourable safety profile,significantly reducing the risk of intracranial haemorrhage(RR=0.46,95%CI 0.31 to 0.68)and major haemorrhagic events(RR=0.49,95%CI 0.34 to 0.70).Conclusions Cilostazol demonstrated superior efficacy and safety profiles compared with traditional antiplatelet regimens such as aspirin and clopidogrel for secondary stroke prevention but does not appear to affect functional outcomes.Future randomised trials can be conducted outside East Asia,or compare cilostazol with a wider range of antiplatelet agents.

关键词： prevention Cilostazol regimen

Sweet plasmonics： Sucrose macrocrystals of metal nanoparticles

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Nano Research 2015年第3期8卷 860-869页

作者： Talha Erdem Zeliha Soran-Erdem Pedro Ludwig Hernandez-Martinez vijay kumar sharma Halil Akcali Ibrahim Akcali Nikolai Gaponik Alexander Eychmeller Hilmi Volkan Demir Departments of Electrical and Electronics Engineering Physics UNAM-National Nanotechnology Research Center and Institute ot Materials Science and Nanotechnology Bilkent University Ankara 06800 Turkey School of Electrical and Electronic Engineering and School of Physical and Mathematical Sciences Nanyang Technological University Singapore 639798 Singapore Physical Chemistry TU Dresden Bergstrasse 66b D-O 1062 Dresden Germany

plasmonic 结构的实现通常要求昂贵的制造技术，例如电子横梁和集中的离子横梁平版印刷术，允许低维的结构的自顶向下的制造。以一种自底向上的方式做 plasmonic 结构的另一条途径是胶体的合成，它对液体状态应用或聚集问题是重要挑战... 详细信息

plasmonic 结构的实现通常要求昂贵的制造技术，例如电子横梁和集中的离子横梁平版印刷术，允许低维的结构的自顶向下的制造。以一种自底向上的方式做 plasmonic 结构的另一条途径是胶体的合成，它对液体状态应用或聚集问题是重要挑战的很薄的稳固的电影方便。用这些方法准备的体系结构典型地不为容易的处理和方便集成是足够柔韧的。因此，开发没有不利地影响 plasmonic，有大规模尺寸的柔韧的站台展示的新 plasmonic 在高需求。作为一个答案，这里我们在场合成结构由金 nanoparticles (Au NP ) 组成在大规模上合并了到蔗糖 macrocrystals 的新 plasmonic，当保存 Au NP 的 plasmonic 性质并且在同时处理提供坚韧性时。作为概念示范的一个证明，我们在场经由在蔗糖晶体结合这些 Au NP 的 plasmonic 的绿 CdTe 量点(QD ) 的荧光改进。获得的合成材料展览厘米规模尺寸和产生的量效率(QE ) 被 58% 经由在 Au NP 和 CdTe QD 之间的相互影响提高(从 24% ～ 38%) 。而且，一从 11.0 ～ 7.40 在光致发光一生弄短 ns，对应于 2.4 的一个地改进因素，在 Au NP 的介绍之上被观察进 QD 合并 macrocrystals。这些结果建议如此的香甜的 plasmonic 晶体是有希望的让大规模柔韧的平台嵌入 plasmonic nanoparticles。

关键词：金属纳米颗粒等离子体蔗糖金纳米粒子制造技术复合结构 CdTe 离子晶体

Extent of mismatch between the period of circadian clocks and light/dark cycles determines time-to-emergence in fruit flies

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Insect Science 2015年第4期22卷 569-577页

作者： Pankaj Yadav Deepak Choudhury Madhumala K. Sadanandappa vijay kumar sharma Chronobiology Laboratory Evolutionary and Organismal Biology Unit Jawaharlal Nehru Centre for Advanced Scientific Research Bangalore 560064 Kamataka India

Circadian clocks time developmental stages of fruit flies Drosophila melanogaster, while light/dark （LD） cycles delimit emergence of adults, conceding only during the ＂allowed gate.＂ Previous studies have revealed that time-to-emergence can be altered by mutations in the core clock gene period （per）, or by altering the length of LD cycles. Since this evidence came from studies on genetically manipulated flies, or on flies maintained under LD cycles with limited range of periods, inferences that can be drawn are limited. Moreover, the extent of shortening or lengthening of time-to-emergence re- mains yet unknown. In order to pursue this further, we assayed time-to-emergence of D. rnelanogaster under 12 different LD cycles as well as in constant light （LL） and constant dark conditions （DD）. Time-to-emergence in flies occurred earlier under LL than in LD cycles and DD. Among the LD cycles, time-to-emergence occurred earlier under T4-T8, followed by T36-T48, and then T12-T32, suggesting that egg-to-emergence duration in flies becomes shorter when the length of LD cycles deviates from 24 h, bearing a strong positive and a marginally negative correlation with day length, for values shorter and longer than 24 h, respectively. These results suggest that the extent of mismatch between the period of circadian clocks and environmental cycles determines the time-to-emergence in Drosophila.

关键词： circadian Drosophila light/dark regimes period time-to-emergence

Effect of cooling media on bead geometry,microstructure,and mechanical properties of wire arc additive manufactured IN718 alloy

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Advances in Manufacturing 2024年第1期12卷 124-149页

作者： Parveen kumar Satish kumar sharma Ratnesh kumar Raj Singh Department of Mechanical Engineering Thapar Institute of Engineering and TechnologyPatialaPunjab147004India

This work aims to present and explore thermal management techniques for the wire arc additive manufacturing(WAAM)of IN718 components.Excessive heat can be mitigated via air or water cooling.In this study,the material was deposited under four different heat-input conditions with air or water cooling.In air cooling,the layer is deposited in a normal atmospheric air environment,whereas with water cooling,the material is deposited inside a water tank by varying the water level.To validate the air and water cooling thermal management techniques,IN718 single-pass and multilayer linear walls were deposited using the bidirectional gas metal arc welding based WAAM setup under four different heat input conditions.During the deposition of single layers,the temperature profiles were recorded,and the geometric and microstructural features were explored.For multilayer wall structures,the mechanical properties(hardness,tensile strength,and elongation)were determined and assessed using the corresponding microstructural features explored through scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),and electron backscatter diffraction(EBSD)analyses.The microstructure observed through SEM analysis in the building direction was found to be nonhomogenous compared with that in the deposition direction.Moreover,water cooling was found to govern bead characteristics,such as wall width and height.The grain size and anisotropy of the mechanical properties also decreased in the water-cooled case.Hence,water cooling is an economical and efficient method to mitigate excessive heat accumulation in WAAM-deposited IN718.

关键词： Air cooling Water cooling IN718 Bead characteristics Microstructure Electron backscatter diffraction(EBSD)

Autologous peripheral blood-derived orthobiologics:Different types and their effectiveness in managing knee osteoarthritis

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World Journal of Orthopedics 2024年第5期15卷 400-403页

作者： Ashim Gupta vijay kumar Jain Department of Orthopaedics and Regenerative Medicine Future BiologicsLawrencevilleGA 30043United States Department of Orthopaedics South Texas Orthopaedic Research Institute(STORI Inc.)LaredoTX 78045United States Department of Regenerative Medicine BioIntegrateLawrencevilleGA 30043United States Department of Orthopaedics and Regenerative Medicine Regenerative OrthopaedicsNoida 201301India Department of Orthopaedics Atal Bihari Vajpayee Institute of Medical SciencesDr.Ram Manohar Lohia HospitalDelhi 110001New DelhiIndia

Knees are the most commonly impacted weight-bearing joints in osteoarthritis(OA),affecting millions of people worldwide.With increasing life spans and obesity rates,the incidence of knee OA will further increase,leading to a significant increase in the economic burden.Conventional treatment modalities utilized to manage knee OA have limitations.Over the last decade,the role of various autologous peripheral blood-derived orthobiologics(APBOs)for the treatment of knee OA has been extensively investigated.This editorial provided an overview and focused on defining and shedding light on the current state of evidence based on the most recent published clinical studies concerning the use of APBO for the management of knee OA.While numerous studies have demonstrated promising results for these preparations,a notable gap exists in the comparative analysis of these diverse formulations.This absence of head-to-head studies poses a considerable challenge for physicians/surgeons in determining the optimal preparation for managing knee OA and achieving sustained longterm results.Thus,more adequately powered,multicenter,prospective,doubleblind,randomized controlled trials with longer follow-ups are needed to establish the long-term efficacy and to aid physicians/surgeons in determining the optimal APBO for the management of knee OA.

关键词： Knee osteoarthritis Platelet-rich plasma Platelet lysate Autologous conditioned serum Gold-induced cytokine Plasma rich in growth factors Growth factor concentrate Autologous protein solution Platelet-rich fibrin Hyperacute serum

Effect of weight-adjusted antimicrobial antibiotic prophylaxis on postoperative dosage and surgical site infection incidence in total joint arthroplasty

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World Journal of Orthopedics 2024年第4期15卷 318-320页

Surgical site infections(SSI)following total joint arthroplasty pose a significant concern for both providers and patients across the globe.Currently,administration of antimicrobial antibiotic prophylaxis is used throughout the world to reduce the incidence of SSI.However,the correct dosage and frequency of administration remains debatable.In this editorial,we emphasized the determination of the effect of administration of weight-adjusted antimicrobial antibiotic prophylaxis regime on the incidence of SSI and postoperative dosage reduction compared to the conventionally used regime during total joint arthroplasty.The results demonstrated similar efficacy between both regimes with respect to the incidence of SSI.In addition,weight-adjustment led to reduced postoperative dosage and has the potential to reduce chances of achieving lower therapeutic concentration,drug resistance,drug toxicity,and costs.

关键词： Antibiotics Antimicrobial prophylaxis Weight-adjusted Surgical site infections Total joint arthroplasty Knee arthroplasty Hip arthroplasty