Designing novel chalcone single crystals with ultrafast nonlinear optical responses and large multi-photon absorption coefficients

Kiran, A.J.,Lee, H.W.,Ravindra, H.J.,Dharmaprakash, S.M.,Kim, K.,Lim, H.,Rotermund, F. Elsevier 2010 Current Applied Physics Vol.10 No.5

A chalcone single crystal, 1-(4-chlorophenyl)-3-(4-methoxyphenyl)prop-2-en-1-one that is transparent over the visible to infrared region is introduced as a new potential material to third-order nonlinear optical applications. The crystal exhibits ultrafast optical response (@?90 fs) and large optical nonlinearity in the wavelength range 800-1200 nm. A very large effective two-photon absorption coefficient β<SUB>eff</SUB>exceeding 120 cm/GW can be obtained with this chalcone crystal, at a low intensity threshold of 41 MW/cm<SUP>2</SUP> The mechanism of nonlinear absorption at different levels of intensity has been discussed. The crystal shows no damage against the laser pulse intensity as high as 8 GW/cm<SUP>2</SUP> We discuss the molecular and crystal designing of chalcones with large and ultrafast optical nonlinearity combined with low optical cut-off (<450 nm).

Variation of embryonic diapause induction in bivoltine silkworm Bombyx mori L (Lepidoptera: Bombycidae) under controlled conditions

( Kiran Rudramuni ),( Bharath Kumar Neelaboina ),( Shivkumar ),( Mir Nisar Ahmad ),( Sukhen Roy Chowdhury ) 한국잠사학회 2021 International Journal of Industrial Entomology Vol.43 No.2

Mulberry silkworm is classified into uni, bi and multivoltine based on the frequency of diapause incidence. The variation in the incidence of diapause in bivoltine silkworm provides a unique opportunity to study the process of evolution of adaptive plasticity towards seasonal variations. The diapause expression in bivoltine silkworm is highly variable and is determined by environmental factors experienced by the maternal generation. Diapause in natural populations is functionally associated with the overwintering mechanism that facilitates survival in harsh winter conditions. In contrast, under standard commercial rearing conditions, the domesticated bivoltine silkworm is known to enter diapause in every generation. This paper presents a short review of the literature dealing with the role of temperature, photoperiod, diapause hormone and its receptor in diapause induction. Also, we briefly review the incidence of non-diapause eggs in bivoltine silkworm under controlled conditions.

Arc behavior in two wire tandem submerged arc welding

Kiran, D.V.,Cho, D.W.,Song, W.H.,Na, S.J. Elsevier 2014 Journal of materials processing technology Vol.214 No.8

Free vibration and static analysis of functionally graded skew magneto-electro-elastic plate

Kiran, M.C.,Kattimani, S.C. Techno-Press 2018 Smart Structures and Systems, An International Jou Vol.21 No.4

This article presents a finite element (FE) model to assess the free vibration and static response of a functionally graded skew magneto-electro-elastic (FGSMEE) plate. Through the thickness material grading of FGSMEE plate is achieved using power law distribution. The coupled constitutive equations along with the total potential energy approach are used to develop the FE model of FGSMEE plate. The transformation matrix is utilized in bringing out the element matrix corresponding to the global axis to a local axis along the skew edges to specify proper boundary conditions. The effect of skew angle on the natural frequency of an FGSMEE plate is analysed. Further, the study includes the evaluation of the static behavior of FGSMEE plate for various skew angles. The influence of skew angle on the primary quantities such as displacements, electric potential, and magnetic potential, and secondary quantities such as stresses, electric displacement and magnetic induction is studied in detail. In addition, the effect of power-law gradient, thickness ratio, boundary conditions and aspect ratio on the free vibration and static response characteristics of FGSMEE plate has been investigated.

Physics-based Interactive Virtual Grasping

Kiran Nasim,Young J. Kim 한국HCI학회 2016 한국HCI학회 학술대회 Vol.2016 No.1

In this paper, we propose an interactive virtual grasping system, enabling physically-realistic interaction between a user and virtual objects, using kinematic hand models whose motions are tracked and controlled in real-time by the user. Since hand tracking devices provide only one-way coupling between the user and kinematic hands resulting in penetrations and friction-less interaction, our method implements the contacts as Coulomb’s friction model and includes a dynamic proxy hand in the system which follows the kinematic virtual hand to provide a two-way control loop for the physics interactions. Our system, taking advantage of the graphics and physics engine of Unity3D, presently allows us to interact with 3D objects in the virtual space in real-time with no visible latency. Moreover, to visually assist the user’s grasping we render the hand model as transparent and provide visual markers at the contact locations. We demonstrate how the use of these tools helps us to perform real-time grasping tasks in complicated virtual environment.

Glycine-assisted Combustion Synthesis and Magnetocaloric Properties of Polycrystalline La0.8Ca0.2MnO3

Kiran P. Shinde,오상수,백승규,김호섭,Bhavesh B. Sinha,정국채 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.61 No.12

A facile and rapid Glycine-assisted combustion method was developed to synthesize polycrystalline La<SUB>0.8</SUB>Ca<SUB>0.2</SUB>MnO<SUB>3</SUB> (LCMO) powder using dissolution of lanthanum nitrate, calcium nitrate, manganese nitrate (oxidant) and Glycine (fuel) as the starting materials and water as solvent, then heating the resulting solution on a heating plate. The x-ray diffraction and FTIR analysis confirms the orthorhombic crystal structure and morphological study shows the polycrystalline form of LCMO powder. The calculated lattice constant a = 5.46, b = 7.73 and c = 5.49 Å are well in agreement with standard values. The magnetic measurements show the paramagnetic behavior of LCMO at room temperature. The maximum change in entropy observed for the LCMO sample is -1.95 J/kgK at an applied magnetic field 2T at Curie temperature of 165 K.

Applications of fixed point theory in Hilbert spaces

Kiran Dewangan 강원경기수학회 2024 한국수학논문집 Vol.32 No.1

In the presented paper, the first section contains strong convergence and demiclosedness property of a sequence generated by Karakaya et al. iteration scheme in a Hilbert space for quasi-nonexpansive mappings and also the comparison between the iteration scheme given by Karakaya et al. with well-known iteration schemes for the convergence rate. The second section contains some applications of the fixed point theory in solution of different mathematical problems.

Biocompatability of carbon nanotubes with stem cells to treat CNS injuries

Kiran Kumar Bokara,Jong Youl Kim,Young Il Lee,Kyungeun Yun,Tom J Webster,Jong Eun Lee 대한해부학회 2013 Anatomy & Cell Biology Vol.46 No.2

Cases reporting traumatic injuries to the brain and spinal cord are extended range of disorders that affect a large percentage of the world's population. But, there are only few effective treatments available for central nervous system (CNS) injuries because the CNS is refractory to axonal regeneration and relatively inaccessible to many pharmacological treatments. The use of stem cell therapy in regenerative medicine has been extensively examined to replace lost cells during CNS injuries. But, given the complexity of CNS injuries oxidative stress, toxic byproducts, which prevails in the microenvironment during the diseased condition, may limit the survival of the transplanted stem cells affecting tissue regeneration and even longevity. Carbon nanotubes (CNT) are a new class of nanomaterials, which have been shown to be promising in different areas of nanomedicine for the prevention, diagnosis and therapy of certain diseases, including CNS diseases. In particular, the use of CNTs as substrates/scaffolds for supporting the stem cell differentiation has been an area of active research. Single-walled and multi-walled CNT's have been increasingly used as scaffolds for neuronal growth and more recently for neural stem cell growth and differentiation. This review summarizes recent research on the application of CNT-based materials to direct the differentiation of progenitor and stem cells toward specific neurons and to enhance axon regeneration and synaptogenesis for the effective treatment of CNS injuries. Nonetheless, accumulating data support the use of CNTs as a biocompatible and permissive substrate/scaffold for neural cells and such application holds great potential in neurological research.

Disaster And Humanitarian Services for Women’s Health in Nepal

Kiran Bajracharya 위기관리 이론과 실천 2016 위기관리 이론과 실천 학술대회 Vol.2016 No.08

In Nepal, natural calamities such as earthquake, floods, landslides, lightening and fire are mostly noticeable disasters that threat to socio-economic loss of the country and people as well. Its effect is observed as even more severe on women, especially to young girls.The earthquake of 2015 affected 5.6 million people including 93,000 pregnant women. Although different governmental and non-government organizations participated actively in post-disaster management, UNFPA particularly focused on its activities towards vulnerable groups such as women, newborns and adolescents. These groups were supported by Minimal Initial Service Package (MISP) that included dignity kits, female-friendly spaces, psychosocial support, reproductive health kits and protection and awareness messages. Life-saving reproductive health camps were organized in the 14 disaster affected districts by partner organizations of UNFPA. Similarly, 14 transition homes were established specially for pregnant and postpartum mothers and health service providers were trained on Clinical Management of Rape as well. Adolescent girls and women were supported through psychosocial counseling and psychological first aid.To conclude, these group must be address further with additional support in terms of capacity building and resource management during reconstruction and rehabilitation phase.

Arc interaction and molten pool behavior in the three wire submerged arc welding process

Kiran, Degala Venkata,Cho, Dae-Won,Song, Woo-Hyun,Na, Suck-Joo Elsevier 2015 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER - Vol.87 No.-

<P><B>Abstract</B></P> <P>A three-dimensional numerical heat transfer and fluid flow model is developed to understand the temperature distribution and molten pool behavior in a three wire submerged arc welding process. The model solves the equations of the conservation of mass, momentum, and energy along with the volume of fluid method. The volume of fluid method is used to track the shape of the free surface. Further, a physical model is developed to estimate the arc center displacement. For a given welding condition, connecting the leading electrode with direct current electrode positive polarity, the middle and trailing electrodes with trapezoidal alternating current waveform displayed deeper weld pools when compared to the sine waveforms. Within the range of welding conditions considered in the present work, weld width is significantly influenced by the leading arc whereas the penetration by the middle and trailing arcs. The computed weld width and penetration are in fair agreement with the corresponding experimental results.</P>