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31.
A universal, second-order, digital-filter structure is proposed, which realises simultaneously a lowpass, a highpass, a bandpass, a notch and allpass transfer function. The structure uses two unit-delays and four multipliers, and is quite attractive for VLSI implementation since a versatile universal chip can be fabricated, which can be used for the implementation of Butterworth, Cheby?shev and elliptic digital filters as well as digital equalisers. 相似文献
32.
Sreepradha Eswaran Anshu Babbar Hannah K. Drescher Thomas C. A. Hitch Thomas Clavel Moritz Muschaweck Thomas Ritz Daniela C. Kroy Christian Trautwein Norbert Wagner Angela Schippers 《International journal of molecular sciences》2021,22(14)
(1) Background: Non-alcoholic fatty liver disease (NAFLD) is a growing global health problem. NAFLD progression involves a complex interplay of imbalanced inflammatory cell populations and inflammatory signals such as reactive oxygen species and cytokines. These signals can derive from the liver itself but also from adipose tissue or be mediated via changes in the gut microbiome. We analyzed the effects of a simultaneous migration blockade caused by L-selectin-deficiency and an enhancement of the anti-oxidative stress response triggered by hepatocytic Kelch-like ECH-associated protein 1 (Keap1) deletion on NAFLD progression. (2) Methods: L-selectin-deficient mice (Lsel−/−Keap1flx/flx) and littermates with selective hepatic Keap1 deletion (Lsel−/−Keap1Δhepa) were compared in a 24-week Western-style diet (WD) model. (3) Results: Lsel−/−Keap1Δhepa mice exhibited increased expression of erythroid 2-related factor 2 (Nrf2) target genes in the liver, decreased body weight, reduced epidydimal white adipose tissue with decreased immune cell frequencies, and improved glucose response when compared to their Lsel−/−Keap1flx/flx littermates. Although WD feeding caused drastic changes in fecal microbiota profiles with decreased microbial diversity, no genotype-dependent shifts were observed. (4) Conclusions: Upregulation of the anti-oxidative stress response improves metabolic changes in L-selectin-deficient mice but does not prevent NAFLD progression and shifts in the gut microbiota. 相似文献
33.
Perumal Selvaraj Kumaresan Natesan Karuppanna Velusamy Thirumalachari Sundararajan 《传热工程》2019,40(1-2):193-201
To study the effect of irradiation on materials, sample coupons are irradiated in cyclotron facilities. During the irradiation process, these samples produce significant heat. This heat needs to be continuously removed from the samples in order to avoid melting of the samples as well as to keep the samples at a particular temperature during irradiation. The area available for heat transfer is limited due to small size of the samples. To increase the heat transfer rate, jet cooling is used as it provides large heat transfer co-efficient. To understand the heat transfer characteristics of jet cooling under these conditions, experiments have been carried out. Two inclined jets hitting on both sides of the target plate give maximum cooling and uniform temperature distribution. This paper gives the details of the numerical and experimental studies carried out and the discussions about the results obtained. 相似文献
34.
Raasti Naseem Liguo Zhao Vadim V. Silberschmidt Yang Liu Senthil K. Eswaran Syed Hossainy 《Polymer Engineering and Science》2019,59(5):1084-1091
Measurement of mechanical parameters of polymeric scaffolds presents a significant challenge due to their intricate shape and small characteristics dimensions of their elements—around 100 μm. In this study, mechanical properties of polymeric tubing and scaffold, made of biodegradable poly(l ‐lactic) acid (PLLA), were characterized using atomic force microscopy (AFM) and nanoindentation, complemented with tensile testing. AFM was employed to assess the properties of the tube and scaffold locally, while nanoindentation produced results with a dependency on the depth of indentation. As a result, the AFM‐measured elastic modulus differs from the nanoindentation data due to a substantial difference in indentation depth between the two methods. With AFM, a modulus between 2 and 2.5 GPa was measured, while a wide range was obtained from nanoindentation on both the tube and scaffold, depending on the indentation scale. Changes in the elastic modulus with in‐vitro degradation and aging were observed over the 1‐year period. To complement the indentation measurements, tensile testing was used to study the structural behavior of the tube, demonstrating the yielding, hardening and fracture properties of the material. POLYM. ENG. SCI., 59:1084–1091, 2019. © 2019 Society of Plastics Engineers 相似文献
35.
R. Jayasree T.S. Sampath Kumar Govindaraj Perumal Mukesh Doble 《Ceramics International》2018,44(8):9227-9235
Calcium phosphate cements (CPCs) are ideally suited for the local delivery of antibiotics in infected bone defects as they have multiple binding sites for loading various drugs. CPCs can also be substituted with ions such as Ag+, Zn2+, Mg2+, Sr2+, etc., to exhibit extended broad-spectrum antimicrobial activity. Strontium (Sr) in particular is known to enhance the new bone formation and decrease bone resorption. The current work aims to develop a dual action tetracalcium phosphate (TTCP) based cement which releases both the Sr2+ ion and ornidazole antibiotic drug for the treatment of bone infections. The TTCP with Sr2+ ion substitution was prepared by the solid state reaction method and it was used to form ornidazole loaded CPC. The ornidazole loaded cement prepared using 8?at% Sr substituted TTCP (8SCPC-O) showed complete hydroxyapatite (HA) formation in phosphate buffered solution at the end of 1 week. Fine needle-shaped HA crystals were observed in 8SCPC-O cement. In vitro drug release studies showed an accelerated ornidazole release from the 8SCPC-O sample when compared to samples without Sr substitution. Ornidazole releasing cements were found to be biocompatible with skeletal myoblast (L6) cells. Antibacterial activity of ornidazole releasing cement was evident from day 1 onwards against E. coli. The above results suggest 8SCPC-O as a good candidate for treating local bone infections. 相似文献
36.
Experiments were conducted on bronze sintered bearings to determine the effect of bearing wall thickness and bearing length on the coefficient of friction. Parameters such as the radial clearance, the surface roughness of the shaft and the lubricating oil were kept constant in all the test bearings during the experiments. It was found that the coefficient of friction increases with the wall thickness and decreases with an increase in bearing length. It is felt that the above result will be useful for the users of sintered bearings in making a judicious selection of the wall thickness and the length of the bearing such that the selection results in a larger bearing metal volume to store more lubricating oil giving a longer life and a reduced coefficient of friction. 相似文献
37.
The Journal of Supercomputing - Wireless sensor networks (WSN) are expected to cover the major portion of the earth’s surface in the coming years. In the era of IoT, the WSN is the major data... 相似文献
38.
Jinming Hu Shengyi Yang Zhenheng Zhang Hailong Li Chandrasekar Perumal Veeramalai Muhammad Sulaman Muhammad Imran Saleem Yi Tang Yurong Jiang Libin Tang Bingsuo Zou 《材料科学技术学报》2021,68(9):216-226
Due to their promising applications in foldable displays,optical communication equipment and environmental monitoring systems,flexible and broadband optoelectronic devices have gained extensive attention in recent years.Here,a flexible and broadband photodetector based on CsPbBr3/PbSe quantum dot(QD) heterostructures is firstly presented.The integrated QD heterostructures possess consecutive detection range from ultraviolet(UV) to long-wave length infrared(LW-IR) regions with efficient light absorption and chemical stability,in comparison with the pristine PbSe QDs.Systematic material characterizations reveal the improved exciton dissociation,carrier transport and carrier lifetime of the QD heterostructures.Flexible photodetector Ag/CsPbBr3/PbSe/Ag demonstrate a high responsivity of 7.17 A/W with a specific detectivity of 8.97 × 1012 Jones under 25 μW/cm2 365 nm illumination at 5 V.Furthermore,it could maintain 91.2 %(or 94.9 %) of its initial performance even after bending for thousands of times(or exposing in ambient air for 4 weeks).More importantly,its re s ponse time is shortened more than three orders of magnitude as that of pristine PbSe QDs-based photodetectors.Therefore,it provides a feasible and promising method for the next-generation high-performance broadband photodetectors via constructing heterostructures of various QDs. 相似文献
39.
Santhosh Kumar S. V. N. Palanichamy Yogesh Selvi M. Ganapathy Sannasi Kannan Arputharaj Perumal Sankar Pariserum 《Wireless Networks》2021,27(6):3873-3894
Wireless Networks - Wireless Sensor Networks (WSNs) is a collection of tiny distributed sensor nodes that have been used to sense the physical parameters of the environment where it has been... 相似文献
40.
Bonghyun Jo Hansol Park Eswaran Kamaraj Sewook Lee Bumho Jung Sivaraman Somasundaram Gyeong G. Jeon Kyu-Tae Lee Namdoo Kim Jong H. Kim Bong-Gi Kim Tae Kyu Ahn Sanghyuk Park Hui Joon Park 《Advanced functional materials》2021,31(5):2007180
Intrinsic characteristics of organic semiconductor-based hole transport materials (HTMs) such as facile synthesizability, energy level tunability, and charge transport capability have been highlighted as crucial factors determining the performances of perovskite photovoltaic (PV) cells. However, their properties in the excited state have not been actively studied, although PVs are operated under solar illumination. Here, the characteristics of organic HTMs in their excited state such as transition dipole moment can be a decisive factor that can improve built-in potential of PVs, consequently enhancing their charge extraction property as well as reducing carrier recombination. Moreover, the aggregation property of organic semiconductors, which has been an essential factor for high-performance organic HTMs to improve their carrier transport property, can induce a synergistic effect with their excited state property for the high-efficiency perovskite PVs. Additionally, it is also confirmed that their optical bandgaps, manipulated to have their absorption in the UV region, are beneficial to block UV light that degrades the quality of perovskite, consequently improving the stability of perovskite PV in p–i–n configuration. As a proof-of-concept, a model system, composed of triarylamine and imidazole-based organic HTMs, is designed, and it is believed that this strategy paves a way toward high-performance and stable perovskite PV devices. 相似文献