Magnetic impurities in the honeycomb Kitaev model

We study the effect of coupling magnetic impurities to the honeycomb lattice spin-1/2 Kitaev model in its spin liquid phase. We show that a spin-S impurity coupled to the Kitaev model is associated with an unusual Kondo effect with an intermediate coupling unstable fixed point K_c J/S separating topologically distinct sectors of the Kitaev model. We also show that the massless spinons in the spin liquid mediate an interaction of the form S_{i\alpha}^{2}S_{j\beta}^{2}/R_{ij}^{3} between distant impurities unlike the usual dipolar RKKY interaction S_{i\alpha}S_{j\alpha}/R_{ij}^{3} noted in various 2D impurity problems with a pseudogapped density of states of the spin bath. Furthermore, this long-range interaction is possible only if the impurities (a) couple to more than one neighboring spin on the host lattice and (b) the impurity spin is not a spin-1/2.$Comment: 4 pages, 3 figures, Published versio

Forest Cover Change Pattern after the Intervention of Community Forestry Management System in the Mid-Hill of Nepal : A Case Study

An account of widespread degradation and deforestation in Nepal has been noticed in various literature sources. Although the contribution of community forests (CF) on the improvement of forest cover and condition in the Mid-hill of Nepal is positive, detailed study to understand the current situation seems important. The study area (Tanahun District) lies in the Gandaki Province of western Nepal. The objective of this study was to estimate the forest cover change over the specified period and to identify factors influencing the change. We used Landsat images from the years 1976, 1991, and 2015 to classify land use and land cover. We considered community perception in addition to the forest cover map to understand the different causes of forest cover change. Forest cover decreased from 1976 to 1991 annually at a rate of 0.96%. After 1991, the forest increased annually at a rate of 0.63%. The overall forest cover in the district regained its original status. Factors related to increasing forest cover were emigration, occupation shift, agroforestry practices, as well as particularly by plantation on barren lands, awareness among forest users, and conservation activities conducted by local inhabitants after the government forest was handed over to community members as a community forest management system.Peer reviewe

Geospatial approach to the risk assessment of climate-induced disasters (drought and erosion) and impacts on out-migration in Nepal

Out-migration is one of the most recognized adaptation practices when dealing with scarce resources and disasters. With the general objective of exploring migration as an impact of climate-induced disasters, our study was conducted in Khaniyapani, in the Sunapati rural municipality of Ramechhap district, Nepal. Disaster prioritization was conducted using the pair-wise ranking method, with results suggesting that drought and soil erosion are the most severe disasters in the study area. The severity maps were prepared using remotely sensed data. A Normalized Difference Drought Index and the Revised Universal Soil Loss Equation were used to produce the drought and erosion severity maps, respectively. Approximately 46.2% of the total study area was found to experience severe droughts, and almost 10% of the area had high soil erosion rates. In total, 100 out of 794 households were interviewed for a semi-structured questionnaire. Drought severity was found to directly impact livelihoods due to a decline in agricultural productivity, a decline in livestock, and drying of water sources. Out of 100 families, 64 practiced seasonal migration. A decline in agricultural productivity and livestock, and water scarcity were identified as the most influencing push factors. Excessive seasonal migration has reduced the resilience of these families. Drought-resistant land, water, and crop management techniques and practices, and alternative income-generating activities should be promoted to curb the seasonal migration.Peer reviewe

Habitat suitability and threat analysis of Greater One-horned Rhinoceros Rhinoceros unicornis Linnaeus, 1758 (Mammalia: Perissodactyla: Rhinocerotidae) in Rautahat District, Nepal

The Greater One-horned Rhinoceros Rhinoceros unicornis has been listed as a Vulnerable species on IUCN Red List, Appendix I of CITES, and a protected animal under the National Parks and Wildlife Conservation Act 2029 B.S., 1973. In Nepal, it was found only in Chitwan, Bardia, Shuklaphanta and Parsa national parks, but it has recently been also reported from the forests of Rautahat. The main objectives of the study were to assess habitat suitability and threats for rhinoceros in Rautahat at an elevation range of approximately 300-1,000 m. Remote sensing data and geospatial modeling techniques were used to assess habitat suitability of rhinoceros. Vegetation assessment was carried out for tree, shrubs, and herbs of plot size 10m × 10m, 5m × 5m, 1m × 1m respectively for habitat suitability. Threat analysis was carried out using purposive sampling among local people and their perceptions were collected on the movement of rhinoceros and threats. The integration of nine explanatory variables showed that about 0.06%, 29.18%, 20.45%, and 50.31% of the study area was found to be most suitable, suitable, moderately suitable and unsuitable habitat respectively for rhinoceros. Out of 30 respondents, 37%, 23%, 20%, and 20% identified the main threat to rhinoceros to be unmanaged habitat, poaching, human-wildlife conflict and environmental factors, respectively. This study recommends parts of the Rautahat District to be extended as the habitat of rhinoceros and starting of immediate conservation initiatives in the area. © Rimal et al. 2018.Peer reviewe

Domestic Violence against Women during the Covid-19: A Case Study of Bihar (India)

The Covid-19 pandemic revealed that the socioeconomic challenges in developing countries intersect within and beyond the dynamics of caste, class, space, and most importantly, gender. The recent outbreak of the Covid-19 pandemic compelled the entire human population to survive on the brink of uncertainty. The subsequent lockdown witnessed an upsurge in domestic abuse cases across the globe, making us realize how the four walls of the familial space turned into a hotbed of the \u27shadow pandemic\u27 resulting from the socioeconomic disparities and individual frustration during difficult times. India also witnessed a sudden surge in domestic violence cases, often called a shadow pandemic. While some got reported, many went without being documented in any forum. In this regard, this research is a case study of Bihar (India), which encountered a higher rate of domestic violence during the pandemic than other states such as Delhi, Haryana, Uttar Pradesh, and Himanchal Pradesh. This empirical study examines the economic, psychological, and social factors responsible for the surge in domestic abuse in Bihar during the Covid-19 pandemic

大面積リボン状浮遊膜の分子配向制御による共役高分子系有機FETにおける異方性電荷輸送の検討

九州工業大学博士学位論文（要旨）学位記番号：生工博甲第335号 学位授与年月日：平成31年3月25

大面積リボン状浮遊膜の分子配向制御による共役高分子系有機FETにおける異方性電荷輸送の検討

Conjugated polymers (CPs) have emerged as one of the potential candidates as active semiconducting elements in organic electronics owing to their low cost device fabrication in the area of organic field effect transistors, organic light emitting diodes and solar cells etc. The main feature of this class material lies in the preparation of the thin film via facile solution processing. CPs are susceptible to anisotropic charge transport owing to their inherent one-dimensional nature. In order to delineate optical anisotropy and anisotropic charge transport various techniques for molecular alignment of CPs have been attempted in the recent past. Existing problems like mechanical damage, solubility of under-layer and difficulty in multilayer film fabrication during molecular alignments needs the development of suitable methods. To circumvent these issues, floating film transfer method (FTM) having capability of anisotropic thin film fabrication have been proposed in the recent past. Although in the proposed FTM oriented films could be easily obtained, most commonly observed circular orientation hinders further upscaling of this method for the large area applications. In this thesis, a new improvisation for unidirectional film spreading during FTM have been made by implementing a newly designed PTFE slider leading to ribbon-shaped floating films and named as Ribbon-shaped FTM. A number of most widely used CPs such as PQT-C12, F8T2, non-regiocontrolled (NR) P3HT, PBTTT-C14, PTB7 and regioregular (RR) P3ATs etc. have been successfully oriented using ribbon-shaped FTM. These oriented films have been characterized by a number of techniques like polarized electronic absorption spectroscopy, atomic force microscopy, X-ray diffraction. Parametric optimization for film casting conditions such as viscosity/temperature of the liquid substrate, temperature and concentration polymer solution were amicably carried out. Influence of these casting conditions on the nature of ribbon-shaped FTM in terms of extent of macroscopic film formation, variation on the optical anisotropy and film thickness were investigated in detail. Amongst several CPs used for investigation, PQT-C12 exhibited not only the optical anisotropy but also the pronounced anisotropic charge transport with highest charge carrier mobility for OFETs based on oriented CPs. PQT-C12 was utilized for in-depth investigation pertaining to the implication molecular weight and its distribution on the optoelectronic anisotropies by synthetizing polymers with different molecular weight and polydispersity index (PDI). It has been found too high or low molecular weights or not favorable for promoting molecular orientation and relatively smaller PDI promotes the facile anisotropic charge transport. One of the batch of synthesized PQT-C12 and large area thin film by ribbon-shape FTM exhibited remarkably high optical anisotropy (DR?22) under at optimized casting condition. Microstructural investigation of these highly oriented films as probed by in plane GIXD exhibited edge-on orientation for the films fabricated under ambient conditions. A clear dependence of extent of molecular orientation on charge carrier mobility and anisotropic charge transport was demonstrated. Intractability of polythiophene led to development of RR-poly(3-alkylthiophene) derivatives but drastic decrease (4-5 orders) in mobility as function increasing alkyl chain length and enforced maximum research on hexyl substituted derivative (P3HT). Efforts were directed to prepare large area oriented thin films of RR-P3ATs by ribbon shaped FTM and influence of molecular orientation on alkyl chain length was investigated. A decease in DR with increasing alkyl chain length substitution was explained by increasing extent of interdigitating alkyl chains as confirmed by XRD results. Moreover, drastic hampering of charge carrier mobility as function of alkyl chain was not observed for FTM oriented films, which was explained by edge-on orientation as evidenced by in-plane GIXD investigations.九州工業大学博士学位論文 学位記番号：生工博甲第335号 学位授与年月日：平成31年3月25日1 Introduction|2 Experimental|3 Ribbon-shaped FTM: parametric optimizations|4 Charge transport in poly(quarterthiophene): Implication of optical anisotropy and molecular weight|5 Optoelectronic properties of conjugated polymers prepared by ribbon-shaped FTM|6 Orientation and anomalous charge transport in regioregular poly (3-alkylthiophenes)|7 General conclusion and future work九州工業大学平成30年

Habitat suitability modeling of Asian Elephant Elephas maximus (Mammalia: Proboscidea: Elephantidae) in Parsa National Park, Nepal and its buffer zone

Asian Elephants Elephas maximus in Nepal are known to have habitats and movement corridors in Parsa National Park (PNP) and its buffer zone (BZ), located east of Chitwan National Park. A study was conducted in this area to assess the suitability of PNP and BZ as elephant use areas, and to determine factors relevant to the presence of elephants in PNP. Field measurements were carried out in 67 plots for vegetation analysis. Boosted Regression Tree (BRT) analysis was used to examine the relationship of habitat suitability and variables including topography (slope, aspect, altitude), climate (precipitation, temperature), habitat preference, ground cover and crown cover. The results indicate that elephant habitat suitability is mainly determined by the dominant plant species, temperature, altitude, habitat preference and precipitation. Slope, ground cover, crown cover and substrate have lesser effects. Elephants were recorded up to 400m in the northeast and southeast aspects of the study area. Most suitable habitats were low slope forest dominated by Acacia catechu and Myrsine semicerate that received 300mm annual precipitation. The model emphasizes environmental suitability, and contributes to knowledge for conservation of elephants in PNP and BZ by delineating sites that require specific planning and management.Peer reviewe

Role of vitamin C on hormonal and pathological changes in Heteropneustes fossilis (Bloch) due to exposure to sodium fluoride

706-713Fluoride is an essential trace element for humans and animals. Here, we explored the effects of sodium fluoride (NaF) on morphological, hormonal and histological changes in ovary of Asian stinging catfish Heteropneustes fossilis (Bloch) after exposure to 1/10th mg and 1/5th mg F/L of LC50 of fluoride in water for 45 and 90 days. Activities of follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T) and estradiol (E) were measured using an enzyme-linked immunosorbent assay. Histological evaluation of the ovaries was conducted after staining with haematoxylin-eosin (HE). Reproductive hormones were significantly decreased after NaF-treated groups. Ovary was found to be adversely effected by exposure to NaF. Maturation of follicles was inhibited by exposure after observation of GSI and histology in ovary. These results suggest that female reproductive system is adversely affected by NaF. NaF may thus significantly reduce the fertility of female fish. This study encompasses alteration in hormonal assay to evaluate the role of vitamins C in the recovery of fluoride toxicity in fish. Vitamin C is a water-soluble ROS scavenger with high potency