n-th power signed graphs

Siva Kota Reddy,Vijay,Lokesha 장전수학회 2009 Proceedings of the Jangjeon mathematical society Vol.12 No.3

A signed graph (marked graph) is an ordered pair S = (G, σ) (S = (G, μ)), where G = (V,E) is a graph called the underlying graph of S and σ : E → {+, −} (μ : V → {+, −}) is a function. The n-th power graph of a graph G = (V,E) is a graph Gn = (V,E'), with same vertex set as G, and has two vertices u and v are adjacent if their distance in G is n or less. Analogously, one can define the nth power signed graph of a signed graph S = (G, σ). Consider the marking μ on vertices of S defined as follows: each vertex v ∈ V , μ(v) is the product of the signs on the edges incident at v. The nth power signed graph of S is a signed graph Sn = (Gn, σ') where Gn is the underlying graph of Sn, where for any edge e = uv 2 Gn, 0(uv) = μ(u)μ(v). It is shown that for any signed graph S, its nth power signed graph Sn is balanced. We then give structural characterization of n-th power signed graphs. Two signed graphs S1 and S2 are switiching equivalent written S1 ~ S2, whenever there exists a marking μ of S1 such that the signed graph Sμ(S1) obtained by changing the sign of every edge of S1 to its opposite whenever its end vertices are of opposite signs, is isomorphic to S2. Further, we present solutions of some signed graph switching equations involving the line signed graph, complement and n-th power signed graph operations. One such equation (L(S))n ~ S generalizes a result of P. Siva Kota Reddy and M. S. Subramanya (L(S) ~ S) [11].

Study on low frequency energy harvesting system in laminated aluminum beam structures with delamination

Siva Subba Rao Patange,S. Raja,Vijayakumar M. P.,V. R. Ranganath 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.5

Piezoelectric material based energy harvesting system (EHS) has been designed and developed to study the influence of delamination on EHS in low frequency vibrating beam structures. The stiffness reduction due to the presence of delamination of specified size and its location is evaluated using the harvested energy in different vibrating elastic modes. Four aluminium beam specimens were fabricated, each having two layers of 1 mm thickness and a specified dimension of delamination was introduced by using a thin Teflon film. The beam without delamination is considered to be healthy and served as the reference structure. The PZT-5H patches were surface bonded on the beams to work as energy harvesting transducers. A suitable electronic circuit is developed to receive the energy from the vibrating beam. The experimental results in terms of energy generated by the four laminated beams have been compared with analytical results at resonant conditions and correlated to assess the effect of delamination on energy produced by low frequency vibration modes. The location of delamination has made a significant change in the harvested energy of second and third bendings; in particular, the delaminations at edge and root have displayed a clear trend. Resonant and off-resonant excitations have revealed that the edge delaminated beam produces lower energy output. The current work has demonstrated that energy harvesting from different elastic modes and with a variable frequency at constant force excitation can be a useful health monitoring technique, employing low frequency vibration, besides utilising the harvested energy itself.

Interplay of Vitamin D and CYP3A4 Polymorphisms in Endocrine Disorders and Cancer

Siva Swapna Kasarla,Vannuruswamy Garikapati,Yashwant Kumar,Sujatha Dodoala 대한내분비학회 2022 Endocrinology and metabolism Vol.37 No.3

Vitamin D has received considerable optimistic attention as a potentially important factor in many pathological states over the past fewdecades. However, the proportion of the active form of vitamin D metabolites responsible for biological activity is highly questionablein disease states due to flexible alterations in the enzymes responsible for their metabolism. For instance, CYP3A4 plays a crucial rolein the biotransformation of vitamin D and other drug substances. Food-drug and/or drug-drug interactions, the disease state, geneticpolymorphism, age, sex, diet, and environmental factors all influence CYP3A4 activity. Genetic polymorphisms in CYP450-encodinggenes have received considerable attention in the past few decades due to their extensive impact on the pharmacokinetic and dynamicproperties of drugs and endogenous substances. In this review, we focused on CYP3A4 polymorphisms and their interplay with vitamin D metabolism and summarized the role of vitamin D in calcium homeostasis, bone diseases, diabetes, cancer, other diseases, anddrug substances. We also reviewed clinical observations pertaining to CYP3A4 polymorphisms among the aforementioned diseaseconditions. In addition, we highlighted the future perspectives of studying the pharmacogenetics of CYP3A4, which may have potential clinical significance for developing novel diagnostic genetic markers that will ascertain disease risk and progression.

Gibberellin Treatment Delays Metabolic Shift during Tomato Ripening

Siva Kumar Malka,Yeo Eun Yun,Me-Hea Park 한국원예학회 2022 한국원예학회 학술발표요지 Vol.2022 No.11

A Brief Review on Variables and Test Priorities of Photovoltaic Module Life Expectancy

Siva Parvathi Padi,Sanchari Chowdhury,Muhammad Aleem Zahid,Jaeun Kim,Eun-Chel Cho,Junsin Yi 한국태양광발전학회 2021 Current Photovoltaic Research Vol.9 No.2

To endorse the reliability and durability of the solar photovoltaic (PV) device several tests were conducted before exposing to the outdoor field in a non-ideal condition. The PV module has high probability that intend to perform adequately for 30 years under operating conditions. To evaluate the long term performance of the PV module in diversified terrestrial conditions, one should use the outdoor performance data. However, no one wants to wait for 25 years to determine the module reliability. The accelerating stress tests performing in the laboratory by mimicking different field conditions are thus important to understand the performance of a PV module. In this review, we will discuss briefly about different accelerating stress types, levels and prioritization that are used to evaluate the PV module reliability and durability before using them in real field.

Human Adipose Tissue Derivatives as a Potent Native Biomaterial for Tissue Regenerative Therapies

Siva Sankari Sharath,Janarthanan Ramu,Shantikumar Vasudevan Nair,Subramaniya Iyer,Ullas Mony,Jayakumar Rangasamy 한국조직공학과 재생의학회 2020 조직공학과 재생의학 Vol.17 No.2

Background: Human adipose tissue is a great source of translatable biomaterials owing to its ease of availability and simple processing. Reusing discardable adipose tissue for tissue regeneration helps in mimicking the exact native microenvironment of tissue. Over the past 10 years, extraction, processing, tuning and fabrication of adipose tissue have grabbed the attention owing to their native therapeutic and regenerative potential. The present work gives the overview of next generation biomaterials derived from human adipose tissue and their development with clinical relevance. Methods: Around 300 articles have been reviewed to widen the knowledge on the isolation, characterization techniques and medical applications of human adipose tissue and its derivatives from bench to bedside. The prospective applications of adipose tissue derivatives like autologous fat graft, stromal vascular fraction, stem cells, preadipocyte, adipokines and extracellular matrix, their behavioural mechanism, rational property of providing native bioenvironment, circumventing their translational abilities, recent advances in featuring them clinically have been reviewed extensively to reveal the dormant side of human adipose tissue. Results: Basic understanding about the molecular and structural aspect of human adipose tissue is necessary to employ it constructively. This review has nailed the productive usage of human adipose tissue, in a stepwise manner from exploring the methods of extracting derivatives, concerns during processing and its formulations to turning them into functional biomaterials. Their performance as functional biomaterials for skin regeneration, wound healing, soft tissue defects, stem cell and other regenerative therapies under in vitro and in vivo conditions emphasizes the translational efficiency of adipose tissue derivatives. Conclusion: In the recent years, research interest has inclination towards constructive tissue engineering and regenerative therapies. Unravelling the maximum utilization of human adipose tissue derivatives paves a way for improving existing tissue regeneration and cellular based therapies and other biomedical applications.

Nanoscale SiOx Tunnel Oxide Deposition Techniques and Their Infl uence on Cell Parameters of TOPCon Solar Cells

Siva Parvathi Padi,Muhammad Quddamah Khokhar,Sanchari Chowdhury,조은철,이준신 한국전기전자재료학회 2021 Transactions on Electrical and Electronic Material Vol.22 No.5

The main goal of solar cell technology is to attain high efficiency, long durability, mass-production, cost-effectiveness, and made with eco-friendly materials. Among the various crystalline silicon solar cell technologies, Tunneling Oxide Passivated Contact (TOPCon) solar cell has its unique style in terms of the structure and carrier transport manner, which predominately decreases the metal contact recombination and gives 1-D carrier transport. A very high efficiency of 26% for TOPCon solar cells has been achieved with the industrial screen print technology and obtained high cell parameter values of V oc and fill factor as 732.3 mV and 84.3% respectively. The tunnel oxide thickness (maintaining < 2 nm) in the TOPCon has its prior impact on the efficiency and electrical parameters of the cell. To obtain the preferable thickness of the tunnel oxide layer various deposition techniques have been reported in the literature. SiOx is the most widely used tunnel oxide material for TOPCon solar cells to date. In this review, different deposition methods that were used for the SiOx tunnel oxide layer such as chemical oxidation, ozone oxidation, thermal oxidation, and plasma-enhanced chemical vapor deposition (PECVD) are elaborated. Moreover, the effect of the deposition conditions on the cell parameters in different techniques are also discussed briefly. Furthermore, the development of TOPCon solar cells and the latest reports that were used diff erent tunnel oxide materials in finding an alternative to SiOx tunnel oxide is discussed.

Simulations for the flow of viscoplastic fluids in a cavity driven by the movement of walls by Lattice Boltzmann Method

Siva Subrahmanyam Mendu,Prasanta Kumar Das 한국유변학회 2020 Korea-Australia rheology journal Vol.32 No.3

The current paper is focused on analyzing the flow of viscoplastic fluid in a cavity that is driven by the two walls. The Lattice Boltzmann method (LBM) is used to solve the discrete Boltzmann equation. To represent the stress-strain rate relationship of viscoplastic fluids, the Bingham Papanastasiou constitutive model is considered. Cavity flow filled with Bingham fluids is considered for validating the present LBM code. After successful validation of the code, the analysis is extended for three dissimilar wall motions- simultaneous and opposed movement of the parallel facing walls, and the simultaneous motion of non-facing walls. The flow dynamics of Bingham fluid is influenced by Reynolds and Bingham numbers which can be studied using velocity and streamline plots. Subsequently, the yielded and un-yielded zones in a cavity have been effectively tracked using the limiting condition of yield stress. Further, the effect of wall motion on the variation of those zones inside a cavity has been studied. Finally, the drag coefficient for considered wall motions is presented.

Overexpressed CYP450 mediated apoptosis evaluates cytotoxicity and teratotoxicity of Cucumis callosus

Siva Prasad Panda,Bikash Ranjan Jena,Gade Kalyani,Uttam Prasad Panigrahy 경희대학교 융합한의과학연구소 2018 Oriental Pharmacy and Experimental Medicine Vol.18 No.4

Fruits of Cucumis callosus (Rottl.) Cogn. (Family: Cucurbitaceae) plant, are commonly known as “bitter cucumber” (English) and “Kachri” (Hindi) in India and have been traditionally used for antioxidant, rich source of vitamin C, antidiabetic and anticancer actions. Tribal peoples of Odissa and West-Bengal are using these fruits during worship and as a vegetable. In vitro cytotoxicity of methanolic seed extract of C. callosus (MSCC) at different concentrations (25, 50, 100, 200, 400) μg/ ml and methanolic pericarp extract of C. callosus (MPCC) at (30, 60, 120, 240, 360) μg/ml on Ehrlich Ascites Carcinoma (EAC) cell line, has been evaluated by using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and Trypan blue dye exclusion assay for a period of 3 h treatment. Acute toxicity and in vivo teratotoxicity of both extracts were also evaluated using the Zebrafish embryo developmental assay. The MSCC and MPCC showed the direct cytotoxic effect on EAC cells in a dose-dependent manner with IG50 value 273.17 and 235.08 μg/ml respectively. The MPCC in 240 and 360 μg/ml showed a strong teratotoxic effect on Zebrafish embryo in a dose-dependent manner. The cytotoxicity and teratotoxicity of MPCC were due to overexpressed CYP450 mediated apoptosis in μthe tissue.

Influence of electrode on the liquid metal embrittlement cracking in the resistance spot welding of Zn coated advanced high strength steels

Siva Prasad Murugan,Kaisar Mahmud,Yeong-Do Park 대한용접·접합학회 2018 대한용접학회 특별강연 및 학술발표대회 개요집 Vol.2018 No.4