Nepal Academy of Science and Technology (NAST)

Science & Technology for National Development

Science for Society : Innovation for Prosperity

Physical Science Laboratory

Buddha Ram Shah, PhD

Tel : +97715547715
Email: ;




Physical Science research laboratory mainly focussed on Radiation Research and Nanomaterilas Research. Radiation Research is centred on ionizing radiation and covering radiofrequency radiation as well as a part of non-ionizing radiation. Major work of radiation research laboratory is to provide Occupational Radiation Dosimetry to the radiation workers especially in various public/private hospitals of Nepal. Under environmental radioactivity measurement program monitoring of background radiation and Radon level assessment are being carried out. Futher Nanomaterials Research is focussed in synthesis and characterization of nano materials.

Current Programs

1. Personal Dosimetry Service

Under this program currently more than 600 radiation professionals from more than 30 hospitals and institutions are being monitored periodically for their absorbed radiation dose using Thermoluminiscent Dosimeter (TLD). Primarily TLD technique uses a TL phosphor of LiF.MgTi in the form of TLD card. A TLD card is normally worn by an individual for a period of three months during one's duty hour. At the end of three months the distributed TLDs are collected for the analysis of exposure and at the same time a new set of TLDs is provided to wear. A project NEP9005 'Strenthening Radiation Safety through Regulatory Infrasructure, Occupational and Medical Exposure control' for four years (2018-21) has been supported by the International Atomic Energy Agency (IAEA). Under Quality Management System (QMS) of our Dosimetry, the calibration of the Reader is being maintained in collaboration with Secondary Standard Dosimetry Laboratory (SSDL) of Nuclear Agency of Malaysia.





Dr. Buddha Ram Shah ( ;

Mr. Bipin Rijal (

Mr. Agni Dhakal (


2. Environmental Radioactivity Measurement

Radioactivity due to decay series of U, Th and K-40 in the environmental samples is being carried out. Using passive radon dosimeters (LR 115 and CR-39) based on Solid State Nuclear Track Detector (SSNTD), indoor radon level study is being carried out in the various locations of the country. Currently Radon level study is under progress in the  earthquake (2015) affected  areas of Sindhupalchowk and Gorkha districts. For real time monitoring of environmental radioactivity, the installation of Micro Gamma Dose Rate Meter is in progress in the NAST Laboratory premises.





Dr. Buddha Ram Shah (

Mr. Bipin Rijal (

Mr. Dinesh Chaudhary, Research Student (


3. Nanomaterials Research

Nanomaterials research is primarily focused onsynthesis, characterization and application of metal oxidenanomaterials. Many metal oxides are very important due to their wide range of electronic and optical properties. These properties can be further altered by appropriate doping processes. In this project metal oxide nanomaterialsare synthesized by the chemical route. Their crystalline properties are examined by X-ray Diffractometer. The optical properties are determined using UV- Visible and FTIR spectroscopy. The electrical properties are measured between room and high temperature using Four Probe method. And the samples are sent elsewhere for morphological studies using Scanning Electron Microscopy and Atomic Force Microscopy.


Photocatalytic effect:

Photocatalytic property of TiO2 has drawn much attention because it is one of the promising materials for the photocatalytic degradation of pollutants. This property is used to treat waste water containing organic contaminants.




Gas sensors:

Nanostructure metal oxides are utilized for sensing applications. Gas sensorsare based on the fact that conductance changes with the reversiblechemisorption process of reactivegases on the surface of metal oxide.In this study, first stable thin films are fabricated from the spin coating technique. The thickness of film can be controlled by the repeatingspin coating procedures. And the resulting structureand electrical conductivity of the filmsare studied.




Dye sensitized solar cells (DSSCs)

Natural dye sensitized solar cells have gained considerable attention in solar energy technology due to their simple fabrication, good efficiency and low production cost. DSSCs are prepared and sensitized by dye extracted from locally available plants.




Biomedical application:

Nanoparticles for biomedical applicationsaresynthesized following simple method in aqueous solution without applying any complicated process, instruments, high temperature and high pressure. These prepared samples are characterized and their antibacterial activity against Gram-positive and Gram-negative bacteria are investigated observing the survivability of bacteria.




            Dr. Deependra Das Mulmi (;


List of Equipments

  • Harshaw 6600 Plus TLD Reader and TLD Cards
  • Berthold Microgamma LB 111 Dose Rate Meter
  • ORTEC Digital Gamma Ray Spectrometer
  • RF Field Strength Meter (TM-196)
  • Kodalpha Radon Dosimeters
  • RadAlert 100TM Dose Rate Meter
  • Spin Coater
  • UV- vis spectrophotometer
  • Four probe resistivity measurement system
  • Hydrothermal reactor

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