Himalayan Physics https://www.nepjol.info/index.php/HP Published by the Department of Physics, PN Campus, Pokhara and the Nepal Physical Society, Western Regional Chapter, Nepal. Full text articles available. http://www.pncampus.edu.np/publication.php en-US Himalayan Physics 2542-2545 Retracted: Temperature and Mass Profile of Far-infrared Skeleton Nebula https://www.nepjol.info/index.php/HP/article/view/18348 <p>The following retraction notice for this article appears in Vol.6&amp;7 2017 <br />DOI: <a href="http://dx.doi.org/10.3126/hp.v6i0.18883">http://dx.doi.org/10.3126/hp.v6i0.18883</a></p><p>On 2<sup>nd</sup> January 2018 the Editorial Board of Himalayan Physics agreed to retract the article <strong>‘Temperature and Mass Profile of Far-infrared Skeleton Nebula’ </strong>published in Himalayan Physics, Vol.6&amp;7 pp.1-4 (DOI: <a href="http://dx.doi.org/10.3126/hj.v6i0.18348">http://dx.doi.org/10.3126/hj.v6i0.18348</a>) because it is a duplication of an article published in Himalayan Physics Vol.1 2010 pp.1-3 (DOI: <a href="http://dx.doi.org/10.3126/hj.v1i0.5162">http://dx.doi.org/10.3126/hj.v1i0.5162</a>).</p><p>Editorial Board, Himalayan Physics<br />2nd January 2018</p> Binil Aryal ##submission.copyrightStatement## 2017-10-12 2017-10-12 1 4 10.3126/hj.v6i0.18348 Thermodynamic and Transport Properties of Molten Bi-In Alloys https://www.nepjol.info/index.php/HP/article/view/18349 <p>We have used simple statistical theory to describe the mixing behavior of liquid Bi-In alloys in terms of energetic and structure through the study of their thermodynamic and transport properties. The structural characteristics of Bi-In melts are described by the two microscopic functions, i.e. the concentration fluctuation in long wavelength limit and the Warren-Cowley short range order parameter. The transport properties are analyzed through the diffusion coefficient ratio and viscosity. The Gibb’s free energy of mixing, enthalpy of mixing and entropy of mixing are the thermodynamic functions which are used to describe the thermodynamic behaviors. In whole analysis thermodynamic input parameter, i.e. interchange energy take important role which is temperature dependent. The computed results are in good agreement with experimental data and support a weak ordering tendency in molten Bi-In system.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (5-9)</p> B. P. Singh B. K. Singh I. S. Jha G. K. Shrestha I. Koirala ##submission.copyrightStatement## 2017-10-12 2017-10-12 5 9 10.3126/hj.v6i0.18349 Thermocouple: Facts and Theories https://www.nepjol.info/index.php/HP/article/view/18350 <p>In reality, thermocouples are extremely versatile and rugged. They are primarily simple devices and can be made to very small dimensions to convert heat into electricity. They are capable of operating over a wide range of temperatures. In addition, they are low in cost and are readily interchanged or replaced. However they do need to be tacit, so that they will measure the quantity that is desired with the precision that is required. In this context, the article presents an explanation about the thermocouple.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (10-14)</p> Krishna Raj Adhikari ##submission.copyrightStatement## 2017-10-12 2017-10-12 10 14 10.3126/hj.v6i0.18350 Assessment of Surface Tension and Viscosity of In-Zn melt https://www.nepjol.info/index.php/HP/article/view/18351 <p>A comparative study of the concentration dependence of surface tension and viscosity of molten In-Zn alloys at 700 K has been performed using energetics, obtained from thermodynamic analysis in the framework of self-association model. The surface tension of the alloys has been calculated from the two methods, layered structure approach and self associating mixture method, and viscosity from Moelwyn-Hughes equation and Kaptay equation. The theoretically computed results for the thermodynamic properties of the alloys are found in excellent agreement with the corresponding experimental results showing that the alloy is segregating in nature. Both surface tension and viscosity of the In-Zn alloy are found to increase with the addition of Zn atoms.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (15-19)</p> R. P. Koirala S. K. Yadav B. P. Singh I. S. Jha D Adhikari ##submission.copyrightStatement## 2017-10-12 2017-10-12 15 19 10.3126/hj.v6i0.18351 Enhancement of Electron Movement in Cytochrome c protein with Water Hydration https://www.nepjol.info/index.php/HP/article/view/18352 <p>Muon spin rotation and relaxation (µSR) measurements have been carried out on oxidized form of cytochrome c protein to understand the relation of electron transfer with water hydration at room temperature. Analysis of µSR data following the Risch-Kehr theory shows that intra- and inter-chain electron movement in the protein enhanced significantly. The three-dimensional diffusion of electron in wet sample (20% relative humidity) is increased around 75% with respect to that in dry sample (5% relative humidity).</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (20-23)</p> Amba Datt Pant ##submission.copyrightStatement## 2017-10-12 2017-10-12 20 23 10.3126/hj.v6i0.18352 Diurnal Variations of Total Ozone Over Kathmandu Measured by Brewer Spectrophotometer https://www.nepjol.info/index.php/HP/article/view/18353 <p>This study presents the diurnal variations of atmospheric total ozone (or ozone content) measurements over Kirtipur, Kathmandu (27.67°N, 83.295°E) using a Brewer Spectrophotometer during a one-year period from February 2001 to February 2002. The measurements of ozone content were made only on daytime period. Result illustrates the significant diurnal variations of total ozone with maximum at near noon and minimum in the early morning and evening hours. The observed increase in total ozone around the noontime is about 5–10% of average ozone value. The monthly averages of total ozone for corresponding times are estimated from the selective days of good data set throughout the measurement period and then the seasonal averages of ozone for corresponding times are determined. The result clearly reveals seasonal diurnal variations of the total ozone with maximum averages values of ozone in spring and summer seasons and moderate in autumn, while minimum value in winter season.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (24-30)</p> Narayan Prasad Chapagain ##submission.copyrightStatement## 2017-10-12 2017-10-12 24 30 10.3126/hj.v6i0.18353 Electronic and Magnetic Properties of Half Metallic Heusler Alloy Co2mnsi: A First-Principles Study https://www.nepjol.info/index.php/HP/article/view/18354 <p>Heusler alloys have been of great interest because of their application in the field of modern technological word. Electronic and magnetic properties of Co, Mn, Si and the Heusler alloy Co<sub>2</sub>MnSi have been studied using Density functional theory based Tight Binding Linear Muffin Tin Orbital with Atomic Sphere Approximation (TB-LMTO-ASA) approach. From the calculation lattice parameter of optimized structure of Co, Mn, Si and Co<sub>2</sub>MnSi are found to be 2.52A0 , 3.49A0 , 5.50A0 , 5.53A0 respectively. Band structure calculations show that Co and Mn are metallic, Si as semi-conducting while the Heusler alloy Co<sub>2</sub>MnSi as half-metallic in nature with band gap 0.29eV. The charge density plot indicates major bonds in Co<sub>2</sub>MnSi are ionic in nature. Magnetic property has been studied using the density of states (DOS), indicating that Co and Co<sub>2</sub>MnSi are magnetic with magnetic moment 2.85μ<sub>B</sub> and 4.91μ<sub>B</sub> respectively. The contribution of orbitals in band, DOS and magnetic moment are due to d-orbitals of Co and Mn and little from s and p-orbital of Si in Co<sub>2</sub>MnSi.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (31-36)</p> Prakash Sharma Gopi Chandra Kaphle ##submission.copyrightStatement## 2017-10-12 2017-10-12 31 36 10.3126/hj.v6i0.18354 Low-cost Instrument for Characterization of Solar Cells https://www.nepjol.info/index.php/HP/article/view/18355 <p>A low cost home-made instrument for characterization of solar cells has provided reliable data for drawing current versus voltage curves of the solar cells under test. The low cost instrument can be an alternative to high-cost standard instruments used for testing solar cells by determining light-to-electricity conversion efficiencies of the solar cells. Calibrations of commercially available mini-solar panels (silicon cells) with respect to a standard pyranometer (SolData) show that the mini-panels can measure solar radiation.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (37-40)</p> Prakash Joshi Joshi ##submission.copyrightStatement## 2017-10-12 2017-10-12 37 40 10.3126/hj.v6i0.18355 Dust Structure around two Asymptotic Giant Stars at Latitude 32&deg; & 40.67&deg; https://www.nepjol.info/index.php/HP/article/view/18356 <p>We studied the dust structures in 60μm and 100μm infrared image around the two asymptotic giant branch (AGB) stars. A systematic search of dust structure in the far infrared (100 μm and 60 μm) Infrared Astronomical Satellite (IRAS) survey was performed using Sky View Observatory. In order to find the possible candidate of cavity structure not yet studied, we used SIMBAD database to locate discrete sources in the region. A new relatively symmetric spherical cavity like structure (size: 1.354 pc × 0.971 pc) for candidate I and (size: 1.424 pc × 0.925pc) for candidate II at R.A.(J2000) =04<sup>h</sup>46<sup>m</sup>13.84<sup>s</sup>, Dec.(J2000) = +32°31’39.6’’ and 05<sup>h</sup>05<sup>m</sup>59.58<sup>s</sup>; +40°40’33.4’’ respectively was found at the distance of about 280 pc and 390 pc. In this present work we have calculated the dust color temperature, mass, outflow velocity, energy and size. We also studied the flux density variation and then calculated temperature and mass profile of the dust and outflow nature of AGB wind using data reduction software’s Aladin v2.5 and Aladinv8.0. Our aim was to test how outflow can be seen in this region. We have studied two cavity-like structures. The dust color temperature is found to lie in the range 21.7 K to 35.6 K for candidate I and 18.5 K to 19.3 K, with an offset of about 14 K and 0.8 K respectively. An offset of 14 K suggests that the AGB is hot in early AGB phase now in late AGB stage. We expect deviation from symmetrical outflow, i.e., AGB wind probably prefer polytropic behaviour implies bipolar type wind whereas the offset 0.8 K for candidate II suggests that the AGB is in the symmetric AGB phase, i.e., early AGB stage. The total mass of the dust in the cavity structure is found about 5.93×10<sup>25</sup> Kg (0.00003M<sub>ʘ</sub>) for candidate I and 1.95×10<sup>27</sup>Kg (0.001 M<sub>ʘ</sub>) for candidate II. In addition we have calculated outflow energy of C-rich AGB star along ISM using outflow velocity of our candidates. It is found that the outflow velocities are 12.96 ms<sup>-1</sup> and 10.71 ms<sup>-1</sup> respectively. For this we have calculated the value of speed of sound (Cs) and escape velocity (u<sub>esc</sub>). In this way we have determined outflow energy, i.e., 1.173×10<sup>25</sup>J and 2.766 × 10<sup>27</sup>J respectively.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (41-47)</p> A. K. Jha D. R. Upadhyay ##submission.copyrightStatement## 2017-10-12 2017-10-12 41 47 10.3126/hj.v6i0.18356 Dust Structure around AGB Star in 60μm and 100 μm IRAS Survey at Latitude 16.10&deg; https://www.nepjol.info/index.php/HP/article/view/18357 <p>A systematic search in the range of J2000 coordinate system provided by K.W. Shu &amp; Y.J. Kwon (2011) of dust structure in the far infrared (100 μm and 60 μm) IRAS (Infrared Astronomical Satellite) survey was performed using Sky View virtual Observatory (1) so that some interesting isolated cavity structures surrounding the cavity structure were expected. The FITS images downloaded from sky view (1) was processed using software Aladin v 2.5. A cavity like structure (major diameter ∼ 3.57 pc &amp; minor diameter ∼ 1.19 pc) lies in the coordinate of R.A. (J2000) 06h 31m 05s and DEC (J2000) 16d 06m 00s was found at the distance ∼ 310 pc (5). We studied the flux density variation and the temperature variation about major diameter, minor diameter and the distance between minimum temperature and minimum flux within the structure. We observed the variation of the temperature is 20.53 K to 21.42 K, with the offset of about 0.89 K, which shows the cavity is independently evolved. The mass profile of each pixel of the structure was also calculated using these temperature.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (48-53)</p> Arjun Kumar Gautam ##submission.copyrightStatement## 2017-10-12 2017-10-12 48 53 10.3126/hj.v6i0.18357 Construction of Dirac Delta Function from the Discrete Orthonormal Basis of the Function Space https://www.nepjol.info/index.php/HP/article/view/18360 <p>Orthonormal basis of the function space can be used to construct Dirac delta function. In particular, set of eigenfunctions of the Hamiltonian operator of a particle in one dimensional infinite potential well forms a non-degenerate discrete orthonormal basis of the function space. Such a simple basis set is suitable to study closure property of the basis and various properties of Dirac delta function in Physics graduate lab.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (54-57)</p> Hari Prasad Lamichhane ##submission.copyrightStatement## 2017-10-12 2017-10-12 54 57 10.3126/hj.v6i0.18360 Structural and Optical Properties of Fluorine Doped Tin Oxide Thin Film Deposited by Home Built Spray Pyrolysis Unit https://www.nepjol.info/index.php/HP/article/view/18361 <p>Fluorine doped Tin Oxide (FTO) thin films were deposited on glass substrates by home built spray pyrolysis setup at (400 ± 5)ºC. The method was found to be very economic and functional. The deposited FTO films were highly transparent and had low resistivity. The structural investigation of as-prepared films was performed using X-ray diffraction. Our results showed that a deposited FTO film was of polycrystalline nature with preferential orientation along (211) planes. The direct band gap value was found to be 3.25eV for 10% FTO film. The sheet resistance of this film was measured to be 68 Ω/ square. The effect of fluorine doping concentration on its band gap was also studied in this report.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (58-60)</p> Maha Prasad Koirala Leela Pradhan Joshi ##submission.copyrightStatement## 2017-10-12 2017-10-12 58 60 10.3126/hj.v6i0.18361 Assessment of Noise Pollution in Different Hatbazars of Butwal City, Rupandehi, Nepal https://www.nepjol.info/index.php/HP/article/view/18362 <p>The study was carried out to ascertain the level of noise pollution at five different hatbazars (periodic markets) of Butwal Sub-Metropolitan city by using Dick Smith Digital Sound Level Meter Q 1362 in the specific time from 4:00 PM to 5:00PM in the month of June 2016 on a hatbazar day and a usual day. The result shows that the heighest Leq of 79.8 dB(A) was observed on hatbazar day at Butwal hatbazar. However, on non hatbazar day the highest Leq of 71.9 dB(A) was observed at Purano bus park hatbazar. The lowest Leq of 64.9 dB(A) and 54.6 dB(A) were respectively observed on hatbazar day and non hatbazar day at Majhagaun hatbazar. The study shows that the noise level was found to be higher on hatbazar day as compared to non hatbazar day in all sampling sites. The commercial activities, crowd of people, unnecessary advertisement of goods, blasting of horns increase noise levels in hatbazars.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (61-64)</p> Kamal Bahadur Rayamajhi ##submission.copyrightStatement## 2017-10-12 2017-10-12 61 64 10.3126/hj.v6i0.18362 Geospatial Analysis of Land Use Land Cover Change Modeling in Phewa Lake Watershed of Nepal by Using GEOMOD Model https://www.nepjol.info/index.php/HP/article/view/18363 <p>Improper practices of land use/ land cover (LULC) are deteriorating watershed conditions. Remote sensing and GIS tools were used to study LULC dynamics using GEOMOD Model and predict the future LULC scenario for years 2015 and 2020, in terms of magnitude and direction, based on past trend in Phewa Lake watershed, Kaski district, Nepal. Due to the proximate and underlying causes, land use and land cover change has become the main challenge of the present world The analysis of LULC pattern during 1995, 2000, 2005 and 2010 using satellite-derived maps has shown that the biophysical and socio-economic drivers including slope, road network and settlements proximity have influenced the spatial pattern of the watershed LULC. These lead to an accretive linear growth of Medium to Fairly Dense Forest, Open Forest, Waste Land and Built-up Land but decrease in other LULC classes. Annual rates of increase from 1995 to 2010 in Medium to Fairly Dense Forest, Open Forest, Waste Land and Built-up land were 75.15, 32.7, 10.14 and 24.2 ha/ year respectively, while the rates decrease in Dense Forest, Terrace Agriculture, Valley Agriculture and Bush/Scrub land were 42.58, 58.17, 27.46 and 2.48 ha/year respectively. The predicted LULC scenario for 2015 and 2020, with reasonably good accuracy would provide useful inputs to the LULC planners for effective management of the watershed. The study is a maiden attempt that revealed the expansion of Waste and Built-up Land, which is the main driving force for loss of Agriculture Land and Grass Land, and an increase in Medium to Fairly Dense Forest and Open Forest leading to decrease in Dense Forest and Bush/Scrub Land in the watershed.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (65-72)</p> R. R. Regmi S. K. Saha D. S. Subedi ##submission.copyrightStatement## 2017-10-12 2017-10-12 65 72 10.3126/hj.v6i0.18363 Parametric Instability in Mathieu Equation in Earthquake Dynamics https://www.nepjol.info/index.php/HP/article/view/18364 <p>We propose an study of parametric resonance between P-waves and S-waves, which can be used to describe various nonlinear phenomena qualitatively and to obtain bifurcation diagrams quantitatively. We have shown that it is a good simulation of parametric phenomena, and our results are in good agreement with theoretical predictions. In particular, it may be used to study the influence of pump P waves on the instability’s threshold and amplitude of S waves in earthquake phenomena that could be simulated with an electronic model.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (73-75)</p> H. Torres-Silva J. López-Bonilla A. Iturri-Hinojosa D. Torres Cabezas ##submission.copyrightStatement## 2017-10-12 2017-10-12 73 75 10.3126/hj.v6i0.18364 Study of Far Infrared Nebula at Declination +53° (J2000) In Iras Map https://www.nepjol.info/index.php/HP/article/view/18365 <p>In this present work we studied the flux density variation, calculate temperature, dust mass and finally Jean’s mass of structure using data reduction software ALADIN2.5. Our aim was to test whether this region is star forming or not. Sky view observatory was used for the search of isolated nebular structure in the far infrared (100 μm and 60 μm) in IRAS (Infrared Astronomical Satellite) catalogue. Stellarium software was used to find coordinate of the structure. A far infrared dust structure (about ~ 11.99 × 3.14 pc.) at Right Ascension (J2000):01<sup>h</sup> 51<sup>m</sup> 56.02<sup>s</sup> Declination (J2000): +53<sup>deg</sup> 27<sup>m</sup> 39.0<sup>s</sup> found at the distance of about 550 pc. The dust color temperature was found to lie in the range 18.02 K to 39.56 K. An offset of about 21 K suggests that the structure is not independently evolved, discrete source may play significant role in structure formation mechanisms. The study of flux variation along major and minor axis of structure showed that mass is concentrate at the center of structure. The total mass of the gas structure was found to be about 1.1432× 10<sup>31</sup>Kg. The Jeans mass was found to be 1.17 x 10<sup>33</sup>Kg, more than that of the total mass of the structure, suggest no clue of star formation.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (76-79)</p> Sabin Gautam Suman Gautam Parashu Ram Poudel ##submission.copyrightStatement## 2017-10-12 2017-10-12 76 79 10.3126/hj.v6i0.18365 Variation of Solar Wind Parameters During Intense Geomagnetic Storms https://www.nepjol.info/index.php/HP/article/view/18366 <p>Geomagnetic disturbances are caused by enhanced solar wind magnetospheric energy coupling process. The principal cause of geomagnetic disturbance is the magnetic reconnection that establishes an electrodynamical coupling between the solar wind plasma and magnetosphere. Around solar maximum, the main structures emanating from the sun are sporadic Coronal Mass Ejection (CMEs) and their interplanetary counterparts (ICMEs). During the descending and minimum solar cycle phases, coronal holes occur more often. They appear as dark regions confined to Solar poles during the solar maximum but expand in size and moves toward the solar equator during the descending phase. In this work, we have taken three different geomagnetic storms during solar maxima. For the interpretation of events, we used interplanetary solar wind data and geomagnetic indices. These satellite data and Dst indices (ranging from -100nT to above) are interpreted by using the method of cross correlation. The values of Bz found approximately 20nT, -50nT and -20nT respectively. Similarly, the value of Dst is -250nT, -400nT and -300nT which shows very intense effect. Likewise, the correlation coefficient we obtained from this research work strongly suggest that interplanetary magnetic field Bz has strong impact for the cause of geomagnetic storms.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (80-85)</p> Ayush Subedi Binod Adhikari Roshan Kumar Mishra ##submission.copyrightStatement## 2017-10-12 2017-10-12 80 85 10.3126/hj.v6i0.18366 Siesmic Activity and its Periphery https://www.nepjol.info/index.php/HP/article/view/18367 <p>Earthquake is a series of vibrations within the earth's crust. It occurs when the earth's crust break due to geological forces on the rock and adjoining plate. Earthquake refers to a movement or tremor of the earth’s crust that originates naturally and below the surface. An earthquake is a vibration or oscillation of the surface of the earth caused by a transient disturbance of the elastic or gravitational equilibrium of the rocks at or beneath the surface. There are two causes of earthquakes. One is religious concept and the other is modern concept. Earthquakes are of different types according to their place of origin and location. There are so many effects of earthquakes.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (86-91)</p> Min Raj Lamsal ##submission.copyrightStatement## 2017-10-12 2017-10-12 86 91 10.3126/hj.v6i0.18367 A Study of Exposure of Overall Background Radiation In Syangja District of Nepal https://www.nepjol.info/index.php/HP/article/view/18368 <p>This study presents general exposure of background radiation to the people living or visiting nine places of Syangja district. A portable GM counter was used to quantify the total radiation at those places. The findings of this study show variation of radiation level at different places. Comparatively large values of radiation counts are observed at high altitude places (Gurung Dada: 70.23 cpm and Pokhari Dada: 64.77 cpm). The value of radiation count inside room is comparatively larger than that at outside room for these places. Moreover, small value of radiation count is observed at river side (Bank of Aandhikhola river: 21.63 cpm). Little large values are observed near Saligram stones and ancient statue than at other regions of one historical/religious place. Hence, results show fluctuations of background radiation level for different places. Some places have comparatively large value of radiation count while some places have comparatively small value. But there is no any abnormal value of radiation counts for all sample places. So there is, generally, no significant risk of public exposure to the background radiation for sample places.</p><p><br /><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (92-95)</p> T Timilsina K. R. Poudel P. R. Poudel ##submission.copyrightStatement## 2017-10-12 2017-10-12 92 95 10.3126/hj.v6i0.18368 Rupture Dynamics and Seismological Variables in Earthquake https://www.nepjol.info/index.php/HP/article/view/18369 <p>The Earthquake results by the movement of tectonic plates. There might be various causes of motion of these plates. Based on type of motion and speed of collision, the nature and strength of earthquake varies. It is difficult to present an unique model of physics to explain the earthquake since the nature and strength significantly varies with time and place.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (96-99)</p> Jeevan Regmi Regmi ##submission.copyrightStatement## 2017-10-12 2017-10-12 96 99 10.3126/hj.v6i0.18369 Study of Structural and Electronic Properties of Fluoride Perovskite KCaF3 using FP-LAPW Method https://www.nepjol.info/index.php/HP/article/view/18370 <p>To study the structural and electronic properties of cubical perovskite KCaF<sub>3</sub>, the first principles calculation within the full potential linearized augmented plane wave (FP-LAPW) method is applied. The exchange correlation effects are included through the GGA exchange potential. The calculated structural properties such as equilibrium lattice constant, the bulk modulus and its pressure derivative are in agreement with the published results of other authors. From our study we have found that the band gap of KCaF<sub>3</sub> is 6.4 eV which is the indication of insulating behavior.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (100-103)</p> K. Neupane R. K. Thapa ##submission.copyrightStatement## 2017-10-12 2017-10-12 100 103 10.3126/hj.v6i0.18370 Superconductivity and Cooper Pairs https://www.nepjol.info/index.php/HP/article/view/18371 <p>In this article, some crucial information is given in regard to superconductivity. The advancement in high temperature superconductivity is believed to solve the problem of energy crisis. So, intensive research in this part of physics is recommended. Actually, Cooper pairs of electrons are responsible for superconductivity.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (104-107)</p> Mitramani Subedi Subedi ##submission.copyrightStatement## 2017-10-12 2017-10-12 104 107 10.3126/hj.v6i0.18371 Topological Order in Physics https://www.nepjol.info/index.php/HP/article/view/18372 <p>In general, we know that there are four states of matter solid, liquid, gas and plasma. But there are much more states of matter. For e. g. there are ferromagnetic states of matter as revealed by the phenomenon of magnetization and superfluid states defined by the phenomenon of zero viscosity. The various phases in our colorful world are so rich that it is amazing that they can be understood systematically by the symmetry breaking theory of Landau. Topological phenomena define the topological order at macroscopic level. Topological order need new mathematical framework to describe it. More recently it is found that at microscopic level topological order is due to the long range quantum entanglement, just like the fermions fluid is due to the fermion-pair condensation. Long range quantum entanglement leads to many amazing emergent phenomena, such as fractional quantum numbers, non- Abelian statistics ad perfect conducting boundary channels. It can even provide a unified origin of light and electron i.e. gauge interactions and Fermi statistics. Light waves (gauge fields) are fluctuations of long range entanglement and electron (fermion) are defect of long range entanglements.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (108-111)</p> Ravi Karki Karki ##submission.copyrightStatement## 2017-10-12 2017-10-12 108 111 10.3126/hj.v6i0.18372 Interval and Speed of Convergence on Iterative Methods https://www.nepjol.info/index.php/HP/article/view/18373 <p>The iterative method is a tool of solving the non-linear equations to get their approximate roots with some errors of tolerance. Repetition of the similar process is applied successively on such iterations to compute a sequence of increasingly accurate estimates of the roots. In this paper, the construction of an iterative method for solving an equation, its convergence and the determination of interval of convergence for the approximate choice of initial guess and the speed of convergence are highlighted.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (112-114)</p> Iswarmani Adhikari ##submission.copyrightStatement## 2017-10-12 2017-10-12 112 114 10.3126/hj.v6i0.18373 Solid State Lightening Component LED: Role in Modern Lightening Technology https://www.nepjol.info/index.php/HP/article/view/18374 <p>An understanding of Light-Emitting Diode (LED) technology is an investment in future prosperity. This article tries to explain the development of LED and how the development of LED lightening technology became a superior business judgment for industrial lightening.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, April 2017 (115-118)</p> Babu Ram Sharma ##submission.copyrightStatement## 2017-10-12 2017-10-12 115 118 10.3126/hj.v6i0.18374 Background Radiation: Detection, Measurement and Hazards https://www.nepjol.info/index.php/HP/article/view/18375 <p>Radiation is a form of energy. It is of two types: non-ionizing and ionizing. Among them, ionizing radiations have hazardous health effects upon human beings. Different types of cancers may arise from the overexposure to ionizing radiations like alpha- particles, beta-particles, gamma- rays, x-rays etc. Further, ionizing radiations have very important utilities in case of paper handling and use. Radiations can be used for various beneficial purposes like medical imaging, radiation therapy, improvement of quality of agriculture, industry etc. The overall radiation from various sources on a specific location on earth's surface refers to the background radiation level of that zone. Exposure to background radiation is an inescapable feature of the environment. A portable GM counter was used to quantify the total radiation level at different places. The finding of this shows a variation of radiation level. Comparatively large values of radiation counts at high altitude and low values at river side. There is no any abnormal value of radiation counts for all sample places. So, there is, generally, no significant risk of public exposure to the background radiation for sample places.</p><p><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, 2017 (119-122)</p> Rajan Paudel Chhetri ##submission.copyrightStatement## 2017-10-12 2017-10-12 119 122 10.3126/hj.v6i0.18375 Fundamental Particle and Forces https://www.nepjol.info/index.php/HP/article/view/18376 The study of particle physics is indispensable not only to understand different branch of science but also to unleash the most profound mysteries in natures such as the mystery of the origin of the Universe. Fundamental particles and their interactions in nature come under the study of Particle Physics, which studies the physical processes that occurs at scales even smaller than atomic nuclei. This article introduces elementary particles and forces, and then focuses on a few promising and interesting area of the particle physics.<br /><br /><strong>The Himalayan Physics</strong> Vol. 6 &amp; 7, 2017 (123-125) Bhumi Raj Sharma ##submission.copyrightStatement## 2017-10-12 2017-10-12 123 125 10.3126/hj.v6i0.18376 Retraction notice for “Temperature and Mass Profile of Far-infrared Skeleton Nebula” https://www.nepjol.info/index.php/HP/article/view/18883 <p>On 2nd January 2018 the Editorial Board of Himalayan Physics agreed to retract the article ‘Temperature and Mass Profile of Far-infrared Skeleton Nebula’ published in Himalayan Physics, Vol.6&amp;7 pp.1-4 (DOI: <a href="http://dx.doi.org/10.3126/hj.v6i0.18348" target="_blank">http://dx.doi.org/10.3126/hj.v6i0.18348</a>) because it is a duplication of an article published in Himalayan Physics Vol.1 2010 pp.1-3 (DOI: <a href="http://dx.doi.org/10.3126/hj.v1i0.5162" target="_blank">http://dx.doi.org/10.3126/hj.v1i0.5162</a>)</p><p>Editorial Board, Himalayan Physics<br />2nd January 2018</p> Editorial Board ##submission.copyrightStatement## 2018-01-02 2018-01-02 10.3126/hp.v6i0.18883