• Title/Summary/Keyword: Kant

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Comparative study of finite element analysis and generalized beam theory in prediction of lateral torsional buckling

  • Sharma, Shashi Kant;Kumar, K.V. Praveen;Akbar, M. Abdul;Rambabu, Dadi
    • Advances in materials Research
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    • v.11 no.1
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    • pp.59-73
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    • 2022
  • In the construction industry, thin-walled frame elements with very slender open cross-sections and low torsional stiffness are often subjected to a complex loading condition where axial, bending, shear and torsional stresses are present simultaneously. Hence, these often fail in instability even before the yield capacity is reached. One of the most common instability conditions associated with thin-walled structures is Lateral Torsional Buckling (LTB). In this study, a first order Generalized Beam Theory (GBT) formulation and numerical analysis of cold-formed steel lipped channel beams (C80×40×10×1, C90×40×10×1, C100×40×10×1, C80×40×10×1.6, C90×40×10×1.6 and C100×40×10×1.6) subjected to uniform moment is carried out to predict pure Lateral Torsional Buckling (LTB). These results are compared with the Finite Element Analysis of the beams modelled with shell elements using ABAQUS and analytical results based on Euler's buckling formula. The mode wise deformed shape and modal participation factors are obtained for comparison of the responses along with the effect of varying the length of the beam from 2.5 m to 10 m. The deformed shapes of the beam for different modes and GBTUL plots are analyzed for comparative conclusions.

Influence of Anaerobically Digested Dairy Waste on Growth and Bio-Active Compounds of Spirulina subsalsa (Cyanobacteria) under Semi-Continuous Culture Conditions

  • Kuntal Sarma;Preeti Chavak;Doli;Manju Sharma;Narendra Kumar;Rama Kant
    • Microbiology and Biotechnology Letters
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    • v.52 no.2
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    • pp.114-121
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    • 2024
  • The present communication deals with the standardization of suitable medium formulation along with anaerobically digested cow's urine (ADCU) for growth of Spirulina subsalsa. Growth was evaluated on the basis of photosynthetic and non-photosynthetic pigment. The results obtained from the study indicated that, SSM-1 and SSM-2 media are suitable for maximum synthesis of chlorophyll-α and carotenoids. The obtained results also indicated that SSM-5 medium is suitable for maximum synthesis of accessory light harvesting pigments phycobiliprotein, total carbohydrate, total protein and total lipid in S. subsalsa. From the study it could be concluded that all the five media combinations (viz. SSM-1, SSM-2, SSM-3, SSM-4 and SSM-5) would be suitable for mass cultivation of S. subsalsa. But among them, SSM-5 medium combination could be the most suitable medium.

Oxidative Stress and Antioxidants in Disease and Cancer: A Review

  • Gupta, Rakesh Kumar;Patel, Amit Kumar;Shah, Niranjan;Choudhary, Arun Kumar;Jha, Uday Kant;Yadav, Uday Chandra;Gupta, Pavan Kumar;Pakuwal, Uttam
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.11
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    • pp.4405-4409
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    • 2014
  • Reactive oxygen species (ROS), highly reactive molecules, are produced by living organisms as a result of normal cellular metabolism and environmental factors, and can damage nucleic acids and proteins, thereby altering their functions. The human body has several mechanisms to counteract oxidative stress by producing antioxidants. A shift in the balance between oxidants and antioxidants in favor of oxidants is termed as "oxidative stress". Paradoxically, there is a large body of research demonstrating the general effect of oxidative stress on signaling pathways, less is known about the initial and direct regulation of signaling molecules by ROS, or what we term the "oxidative interface." This review focuses on the molecular mechanisms through which ROS directly interact with critical signaling molecules to initiate signaling in a broad variety of cellular processes, such as proliferation and survival (MAP kinases and PI3 kinase), ROS homeostasis, and antioxidant gene regulation (Ref-1 and Nrf-2). This review also deals with classification as well as mechanisms of formation of free radicals, examining their beneficial and deleterious effects on cellular activities and focusing on the potential role of antioxidants in preventing and repairing damage caused by oxidative stress. A discussion of the role of phytochemical antioxidants in oxidative stress, disease and the epigenome is included.

Investigating the use of wollastonite micro fiber in yielding SCC

  • Sharma, Shashi Kant;Ransinchung, G.D.;Kumar, Praveen
    • Advances in concrete construction
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    • v.6 no.2
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    • pp.123-143
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    • 2018
  • Self compacting concrete (SCC) has good flowability, passability and segregation resistance because of voluminous cementitious material & high coarse aggregate to fine aggregate ratio, and high free water availability. But these factors make it highly susceptible to shrinkage. Fibers are known to reduce shrinkage in concrete mixes. Until now for conserving cement, only pozzolanic materials are admixed in concrete to yield a SCC. Hence, this study compares the use of wollastonite micro fiber (WMF), a cheap pozzolanic easily processed raw mineral fiber, and flyash in yielding economical SCC for rigid pavement. Microsilica was used as a complimentary material with both admixtures. Since WMF has large surface area ($827m^2/kg$), is acicular in nature; therefore its use in yielding SCC was dubious. Binary and ternary mixes were constituted for WMF and flyash, respectively. Paste mixes were tested for compatibility with superplasticizer and trials were performed on a normal concrete mix of flexural strength 4.5 MPa to yield SCC. Flexural strength test and restrained shrinkage test were performed on those mixes, which qualified self compacting criteria. Results revealed that WMF admixed pastes have high water demand, and comparable setting times to flyash mixes. Workability tests showed that 20% WMF with microsilica (5-7.5%) is efficient enough in achieving SCC and higher flexural strength than normal concrete at 90 days. Also, stress rate due to shrinkage was lesser and time duration for final strain was higher in WMF admixed SCC which encourages its use in yielding a SCC than pozzolanic materials.

Digital Animation As a New Medium Taking a View of Bolz Media Theory (미디어미학에서 바라 본 뉴미디어로써 디지털 애니메이션 - 노르베르트 볼츠의 매체미학을 중심으로 -)

  • 이종한
    • Archives of design research
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    • v.16 no.4
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    • pp.225-232
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    • 2003
  • A German philosopher, Herbert Bolz predicted that the human way of thinking would be fundamentally and completely changed because of digital media and the 'Gutenberg-Galaxis', named by M.McLuhan which was symbolized of modern reason was doomed to be over. He thought that the limit of reason-centered European culture would be overcome by the up-to-date multimedia to revive the communication life. On this theory, he emphasized the emotional perception, 'aisthesis' which is original meaning of aesthetics. That is to say, he insisted on the restoration of communication media to enable the five senses' amusement condition mentioned by Kant. This thesis asserts that the representative hypermedia digital animation may play a key role to rehabilitate human sensibility pressed by reason centered modernism. Digital animation has the unique worth of Art that is firstly to deal with time and space and enable unlimited expressions and can communicate effectively as a characteristic synthetic medium which consists of intensive computer techniques. Based on the background, this thesis analyzes the possibility of the digital animation as a new medium. Especially, it is focused on the relations to the hypermedia theory of Norbert Bolz who is a media analyst and professor of a design college.

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A Liquid-Based Colorimetric Assay of Lysine Decarboxylase and Its Application to Enzymatic Assay

  • Kim, Yong Hyun;Sathiyanarayanan, Ganesan;Kim, Hyun Joong;Bhatia, Shashi Kant;Seo, Hyung-Min;Kim, Jung-Ho;Song, Hun-Seok;Kim, Yun-Gon;Park, Kyungmoon;Yang, Yung-Hun
    • Journal of Microbiology and Biotechnology
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    • v.25 no.12
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    • pp.2110-2115
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    • 2015
  • A liquid-based colorimetric assay using a pH indicator was introduced for high-throughput monitoring of lysine decarboxylase activity. The assay is based on the color change of bromocresol purple, measured at 595 nm in liquid reaction mixture, due to an increase of pH by the production of cadaverine. Bromocresol purple was selected as the indicator because it has higher sensitivity than bromothymol blue and pheonol red within a broad range and shows good linearity within the applied pH. We applied this for simple determination of lysine decarboxylase reusability using 96-well plates, and optimization of conditions for enzyme overexpression with different concentrations of IPTG on lysine decarboxylase. This assay is expected to be applied for monitoring and quantifying the liquid-based enzyme reaction in biotransformation of decarboxylase in a high-throughput way.

Optimization of Direct Lysine Decarboxylase Biotransformation for Cadaverine Production with Whole-Cell Biocatalysts at High Lysine Concentration

  • Kim, Hyun Joong;Kim, Yong Hyun;Shin, Ji-Hyun;Bhatia, Shashi Kant;Sathiyanarayanan, Ganesan;Seo, Hyung-Min;Choi, Kwon Young;Yang, Yung-Hun;Park, Kyungmoon
    • Journal of Microbiology and Biotechnology
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    • v.25 no.7
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    • pp.1108-1113
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    • 2015
  • Cadaverine (1,5-diaminopentane) is an important industrial chemical with a wide range of applications. Although there have been many efforts to produce cadaverine through fermentation, there are not many reports of the direct cadaverine production from lysine using biotransformation. Whole-cell reactions were examined using a recombinant Escherichia coli strain overexpressing the E. coli MG1655 cadA gene, and various parameters were investigated for the whole-cell bioconversion of lysine to cadaverine. A high concentration of lysine resulted in the synthesis of pyridoxal-5'-phosphate (PLP) and it was found to be a critical control factor for the biotransformation of lysine to cadaverine. When 0.025 mM PLP and 1.75 M lysine in 500 mM sodium acetate buffer (pH6) were used, consumption of 91% lysine and conversion of about 80% lysine to cadaverine were successfully achieved.

Nonlinear analysis of reinforced concrete beams strengthened with polymer composites

  • Pendhari, S.S.;Kant, T.;Desai, Y.M.
    • Structural Engineering and Mechanics
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    • v.24 no.1
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    • pp.1-18
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    • 2006
  • Strengthening of existing old structures has traditionally been accomplished by using conventional materials and techniques, viz., externally bonded steel plates, steel or concrete jackets, etc. Alternatively, fibre reinforced polymer composite (FRPC) products started being used to overcome problems associated with conventional materials in the mid 1950s because of their favourable engineering properties. Effectiveness of FRPC materials has been demonstrated through extensive experimental research throughout the world in the last two decades. However there is a need to use refined analytical tools to simulate response of strengthened system. In this paper, an attempt has been made to develop a numerical model of strengthened reinforced concrete (RC) beams with FRPC laminates. Material models for RC beams strengthened with FRPC laminates are described and verified through a nonlinear finite element (FE) commercial code, with the help of available experimental data. Three dimensional (3D) FE analysis has been performed by assuming perfect bonding between concrete and FRPC laminate. A parametric study has also been performed to examine effects of various parameters like fibre type, stirrup's spacing, etc. on the strengthening system. Through numerical simulation, it has been shown that it is possible to predict accurately the flexural response of RC beams strengthened with FRPC laminates by selecting an appropriate material constitutive model. Comparisons are made between the available experimental results in literature and FE analysis results obtained by the present investigators using load-deflection and load-strain plots as well as ultimate load of the strengthened beams. Furthermore, evaluation of crack patterns from FE analysis and experimental failure modes are discussed at the end.

Comparative Analysis of Oct4 in Different Histological Subtypes of Esophageal Squamous Cell Carcinomas in Different Clinical Conditions

  • Vaiphei, Kim;Sinha, Saroj Kant;Kochhar, Rakesh
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.8
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    • pp.3519-3524
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    • 2014
  • Background: Esophageal squamous cell carcinoma (ESCC) is a common cancer with poor prognosis. It has been hypothesized that Oct4 positive radioresistant stem cells may be responsible for tumor recurrence. Hence, we evaluated Oct4 expression in ESCC in pre-treatment, post neo-adjuvant residual and post-surgical recurrent tumours. Materials and Methods: Endoscopic mucosal biopsies were used to study Oct4 expression and the observations were correlated with histological tumor grades, patient data and clinical background. Results: All patients presented with dysphagia with male predominance and a wide age range. Majority of the patients had intake of mixed diet, history of alcohol and tobacco intake was documented in less than half of the patients. Oct 4 expression was significantly higher in poorly differentiated (PDSCC) and basaloid (BSCC) subtypes than the other better differentiated tumor morphology. Oct4 was also expressed by adjoining esophageal mucosa showing low grade dysplasia and basal cell hyperplasia (BCH). Biopsies in PDSCC and BSCC groups were more likely to show a positive band for Oct4 by polymerase chain reaction (PCR). Dysplasia and BCH mucosa also showed Oct4 positivity by PCR. All mucosal biopsies with normal morphology were negative for Oct4. Number of tissue samples showing Oct4 positivity by PCR was higher than that by the conventional immunohistochemistry (p>0.05). Oct4 expression pattern correlated only with tumor grading, not with other parameters including the clinical background or patient data. Conclusions: Our observations highlighted a possible role of Oct4 in identifying putative cancer stem cells in ESCC pathobiology and response to treatment. The implications are either in vivo existence of Oct4 positive putative cancer stem cells in ESCC or acquisition of cancer stem cell properties by tumor cells as a response to treatment given, resulting ultimately an uncontrolled cell proliferation and treatment failure.

Associations of CYP1A1, GSTM1 and GSTT1 Polymorphisms with Lung Cancer Susceptibility in a Northern Indian Population

  • Shukla, R.K.;Tilak, A.R.;Kumar, C.;Kant, S.;Kumar, A.;Mittal, B.;Bhattacharya, S.
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.5
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    • pp.3345-3349
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    • 2013
  • Background: Susceptibility to lung cancer has been shown to be modulated by inheritance of polymorphic genes encoding cytochrome P450 1A1 (CYP1A1) and glutathione S transferases (GSTM1 and GSTT1), which are involved in the bioactivation and detoxification of environmental toxins. This might be a factor in the variation in lung cancer incidence with ethnicity. Materials and Methods: We conducted a case-control study of 218 northern Indian lung cancer patients along with 238 healthy controls, to assess any association between CYP1A1, GSTM1 and GSTT1 polymorphisms, either separately or in combination, with the likelihood of development of Lung cancer in our population. Results: We observed a significant difference in the GSTT1 null deletion frequency in this population when compared with other populations (OR=1.87, 95%CI: 1.25-2.80-0.73, P=0.002). However, GSTM1 null genotype was found associated with lung cancer in the non-smoking subgroup. (P=0.170). Conclusions: Our study showed the GSTT1 null polymorphism to be associated with smoking-induced lung cancer and the GSTM1 null polymorphism to have a link with non-smoking related lung cancer.