We identified a single putative PKS type III encoding gene in S. peucetius ATCC 27952 and named sp-rppA. Sequence alignment of the deduced Sp-RppA sequence with the known type III PKSs provided strong bootstrap support for heterologous expression. Thus, we set out to determine the in vitro and in vivo function of the Sp-RppA gene. Our result showed that Sp-RppA is a key enzyme,1,3,6,8tetrahydroxynaphthalene synthase (THNS) that catalyzes the condensation of five molecules of malonyl-CoA to form THN, which readily oxidizes to give 2,5,7-trihydroxy-1,4naphthoquinone (flaviolin).
*Gopal Prasad Ghimire is an associate professor in Chemistry at the Institute of Engineering, Western Region Campus, Tribhuvan University, Lamachaur, Pokhara. He has a PhD from the Department of Life Science and Biochemical Engineering, Sun Moon University, Republic of Korea. He has also served as a visiting professor at Sun Moon University, Korea. He has over 20 articles published in national and international peer reviewed journals. His research area include genetic engineering, isolation and purification of natural products, combinatorial biosynthesis etc.
Date: 05 August, 2017
21 Shrawan, 2074
Complex metal oxides having good dielectric properties are being used as dielectric resonators in mobile phone communications. Currently, commercially used materials at various frequency ranges are oxide material with complex perovskite structure. Ceramic oxides with perovskite structure, in particular A(B’1/3B”2/3)03, exhibit excellent microwave properties. Ceramic pucks suitable for resonator applications are designed to sustain a standing wave within its body of a specific resonant frequency to get hassle free network connectivity. One of the solutions to the network hassle is related to the chemical aspect i.e. quality of the resonator used in the base station of the mobile phone network. The rapid progress in microwave telecommunication generated a huge demand for such dielectric resonators. New dielectric ceramics are required as components of base-station filters for next-generation microwave communication networks. As a result, the production of dielectric resonators emerged as one of the fastest growing area today in the electronic ceramic manufacturing. Synthesis of various composites and solid solution involving eight layered Perovskites are in progress. These composites are highly promising and can be tuned to zero Γf values.
*Ram Jeewan Yadav is an Assistant Professor of Chemistry at Department of Chemistry, PN Campus. He has more than two decades of working experience in academia as a science educator and a researcher in various capacities. He has PhD degree in Chemistry from Delhi University India. His research interest and expertise includes, but not limited to Material Science, Microwave dielectrics, Mobile/Wireless Communications, Dye Sensitized Solar Cells (DSSC), Nanomaterials etc. He has authored more than 13 research articles in national and international journals. He has served as Executive Director of Open University Infrastructure Development Board, Ministry of Education, Government of Nepal.
Date: 22 July, 2017
07 Shrawan, 2074
There has been an explosive growth of interest in various kinds low-dimensional structures in recent decades. Low dimensional systems are of tremendous importance not only from their practical applications in various field but also from fundamental science point of view. Until very recently, the field of low-dimensional physics was dominated by purely carbon based systems such as Fullerene(OD), carbon nanotubes (1D) and graphene (2D). An interesting candidate for nanoworld is silicon carbide (SIC) which, in bulk form, is one of the hardest materials and is very suitable for electronic devices designed for operations in extreme environments. In addition to the properties due to quantum size effect, silicon carbide nanostructures have some of these unique properties of bulk silicon carbide. Studies have shown that the silicon carbide nanostructures have even more additional unique properties as compared to the bulk. The talk will mainly focus on computational studies on various nanostructures of silicon carbide.
*Kapil Adhikari is Coordinator of Physics Research Initiative (PRI) Pokhara and Adjunct Faculty of Physics at Department of Physics, PN Campus. He completed his M.Sc. from Tribhuvan University and Ph.D. in Computational Condensed Matter Physics from University of Texas at Arlington, USA. He has over four years of experience as a postdoctoral researcher, lecturer and visiting scientist in various institutes in the USA and in Qatar Foundation in Qatar. He has authored more than 15 articles in international peer reviewed journals. His research has focused on theoretical and computational nanoscience, actinides and their oxides, active pharmaceutical ingredients, energetic materials, computational crystal engineering and benchmarking of quantum chemistry softwares in high performance computing environment.
Date: 08 July, 2017
24 Asar, 2074
Space Weather is the concept of changing the environment in near-Earth Space. The environment in near earth space is greatly affected by plasma particles, radiations, and other matters in space. The space environment is also greatly influenced by the speed and density of solar wind and the Interplanetary magnetic field (IMF). Coronal mass ejections and their associated shock waves are also important drivers of space weather as they can compress the magnetosphere and trigger geomagnetic storms. These particles and masses when interact in ionosphere, compress the ionosphere and Increases the total electron content(TEC), which affects the radio propagation. This presentation focus on the dynamics of sun and the various ejected components that threatens the near-Earth space environment. In addition, the effects of space weather and the key ways of obtaining the data to minimize the space weather effects will be highlighted.
*Suman Gautam is a faculty at Department of Physics, PN Campus, Pokhara. He works as a science communicator at Nepal Astronomical Society (NASO). He is an emerging space leader for International Astronautical Congress (IAC-2014). He has experiences working in PRL India and in various programs conducted by United Nations as an attendee and presenter. His research focuses on Space weather and its effects on ionosphere.
Date: 03 June, 2017
20 Jestha, 2074
Layered van der Waals materials including transitional metal dichalcogenides (TMDs) have emerged as potential alternative materials for ultra-thin and low power nanoelectronics and optoelectronics devices. Highly tunable and unique electronic properties of TMDs enable them as promising novel materials for various other applications as well. However, in order to realize the superior performance of devices based on TMDs, the physical and chemical properties need to be understood, in particular, their defect chemistries and stabilities under various chemical environments. In this talk, I will present our attempt to understand the nature of defect structures, oxidation mechanism, alloying, TMD-oxide interfaces and their corresponding electronic properties. In addition, the effects of the dielectric environment on the electronic and optical properties of a single layer TMDs will be discussed. Moreover, the impact of various interfacial defects on electronic properties will be included, which in fact help to simulate the realistic interfacial phenomenon and optimize the properties of the semiconducting devices.
*Santosh KC is a post-doctoral research associate at the theory group in the Materials Science and Technology Division at Oak Ridge National Laboratory (ORNL), USA. He has obtained his Ph.D. in Materials Science and Engineering in 2014. His research focuses on computational materials and condensed matter physics using first principles based quantum mechanical computations. He has conducted several research projects in order to understand the atomic level descriptions of bulk, surface, and interfacial properties of compound semiconductors, two dimensional (2D) materials like transition-metal dichalcogenides (TMDs) for electronic device applications. In addition, he has investigated various solid electrolytes and electrode-electrolyte interfaces for Li-ion battery applications.
Date: 27 April, 2017
14 Baisakh, 2074