Population Densities Of States Research Articles

Processes of Forest Cover Change since 1958 in the Coffee-Producing Areas of Southwest Ethiopia

We investigated the spatial relations of ecological and social processes to point at how state policies, population density, migration dynamics, topography, and socio-economic values of ‘forest coffee’ together shaped forest cover changes since 1958 in southwest Ethiopia. We used data from aerial photos, Landsat images, digital elevation models, participatory field mapping, interviews, and population censuses. We analyzed population, land cover, and topographic roughness (slope) data at the ‘sub-district’ level, based on a classification of the 30 lowest administrative units of one district into the coffee forest area (n = 17), and highland forest area (n = 13). For state forest sites (n = 6) of the district, we evaluated land cover and slope data. Forest cover declined by 25% between 1973 and 2010, but the changes varied spatially and temporally. Losses of forest cover were significantly higher in highland areas (74%) as compared to coffee areas (14%) and state forest sites (2%), and lower in areas with steeper slopes both in coffee and highland areas. Both in coffee and highland areas, forest cover also declined during 1958–1973. People moved to and converted forests in relatively low population density areas. Altitudinal migration from coffee areas to highland areas contributed to deforestation displacement due to forest maintenance for shade coffee production in coffee areas and forest conversions for annual crop production in highland areas. The most rapid loss of forest cover occurred during 1973–1985, followed by 2001–2010, which overlapped with the implementations of major land and forest policies that created conditions for more deforestation. Our findings highlight how crop ecology and migration have shaped spatial variations of forest cover change across different altitudinal zones whilst development, land, and forest policies and programs have driven the temporal variations of deforestation. Understanding the mechanisms of deforestation and forest maintenance simultaneously and their linkages is necessary for better biodiversity conservation and forest landscape management.

POLES AND AREAS OF INACCESSIBILITY IN THE LIGHT OF THE CONCEPT OF THE WORLD “POLARIZED LANDSCAPE”

Boris Rodoman’s concept of a polarized landscape is to create a universal model for the harmonious distribution on the planet of opposing environmental types: wildlife and large cities, between which transitional functional zones are located. In the case of landscape polarization, there will be a sustainable development of society. Further developing this concept, we can classify these territories that are opposite in function and study the dependence of their distribution on the population density of a particular state or region. Among the uninhabited territories, poles of inaccessibility stand out - the most remote points from the infrastructure. Around them the areas of inaccessibility are formed; they are limited by infrastructure facilities. They can be of different scales: micro level, meso level, macro level and mega level. Territorial systems modified by humans are called anthropogenic landscapes. In terms of extent, their levels correspond to the areas of inaccessibility: micro level, meso level, and macro level. To study the sizes of inaccessibility areas and sections of anthropogenic landscape, the methods of studying satellite images and GIS technology were used in the work. The territory of the Perm region has been analyzed as an example. As a result, it turned out that the area of anthropogenic landscape is 42% of the region’s territory, and 58% is inaccessible areas. Also, studying space images of other regions and countries of Eurasia, the dependence of the anthropogenic landscape area (% of the total area of region) on the population density in all the studied regions of Eurasia was revealed: 0-2 people/km² - 0 to 20 %, 2-10 people/km² - 20-40 %, 10-50 people/km² - 40-60 %, 50-100 people/km² - 60-80 %, more than 100 people/km² - 80-100 %.

COVID-19 prevalence and fatality rates in association with air pollution emission concentrations and emission sources

The novel coronavirus disease (COVID-19) is primarily respiratory in nature, and as such, there is interest in examining whether air pollution might contribute to disease susceptibility or outcome. We merged data on COVID-19 cumulative prevalence and fatality rates as of May 31, 2020 with 2014–2019 pollution data from the US Environmental Protection Agency Environmental Justice Screen (EJSCREEN), with control for state testing rates, population density, and population covariate data from the County Health Rankings. Pollution data included three types of air emission concentrations (particulate matter<2.5 μm (PM2.5), ozone and diesel particulate matter (DPM)), and four pollution source variables (proximity to traffic, National Priority List sites, Risk Management Plan (RMP) sites, and hazardous waste treatment, storage and disposal facilities (TSDFs)). Results of mixed model linear multiple regression analyses indicated that, controlling for covariates, COVID-19 prevalence and fatality rates were significantly associated with greater DPM. Proximity to TSDFs was associated to greater fatality rates, and proximity to RMPs was associated with greater prevalence rates. Results are consistent with previous research indicating that air pollution increases susceptibility to respiratory viral pathogens. Results should be interpreted cautiously given the ecological design, the time lag between exposure and outcome, and the uncertainties in measuring COVID-19 prevalence. Areas with worse prior air quality, especially higher concentrations of diesel exhaust, may be at greater COVID-19 risk, although further studies are needed to confirm these relationships.

Compressive behavior and electronic properties of ammonia ice: a first-principles study.

Understanding the compressive behavior of ammonia ice is an enduring topic due to its salient implications in planetology and the origin of life as well as its applications in agriculture and industry. Currently, the most stable crystal structures of ammonia ice with increasing pressure have been determined to be P213, P212121, Pma2, Pca21, P21/m and Pnma, respectively. Taking these six crystal structures for consideration, the pressure-induced structural and electronic behavior of ammonia ice was systematically investigated using density functional theory calculations. According to our calculations, the transition from molecular phase P212121 to ionic phase Pma2 can be ascribed to the bonds between H atoms and N atoms on adjacent NH3 molecules. Analysis of the Mulliken population and electron density of states implies decreased charge transfer between the N and H atoms and enhanced bonds with increasing pressure. In addition, charge overlap between NH3 molecules was found at high pressure in the molecular phases of ammonia ice, which is also observed between NH2− and NH4+ groups in ionic phases. With increasing pressure, the band gap of ammonia ice increases rapidly and then decreases gradually, which is a consequence of the subtle competition between the strong coupling in the H 1s and N 2p states and the charge overlap. These simulations help us understand the characteristics of ammonia ice under high pressure and further provide valuable insights into the evolution of planets.

Diagnostic Radiologists' Participation in the American Board of Radiology Maintenance of Certification Program.

OBJECTIVE. Physicians across specialties have expressed concerns about Maintenance of Certification (MOC) programs of American Board of Medical Specialties member boards, calling for research about MOC acceptance, adoption, and value. The purpose of this study was to characterize diagnostic radiologists' participation in the American Board of Radiology (ABR) MOC program, the framework for its new Online Longitudinal Assessment program. MATERIALS AND METHODS. Practicing U.S. radiologists were identified from the Centers for Medicare & Medicaid Services Physician and Other Supplier Public Use File. Corresponding ABR diplomate certification information was obtained through the ABR public search engine. Focused on diagnostic radiologists (defined as those whose only ABR certificate is in diagnostic radiology), MOC participation rates were calculated across various physician characteristics for those whose participation was mandated by the ABR (time-limited certificates) and for those whose participation was not mandated (lifetime certificates). RESULTS. Among 20,354 included diagnostic radiologists, 11,479 (56.4%) participated in MOC. Participation rates were 99.6% (10,058/10,099) among those whose MOC was ABR mandated and 13.9% (1421/10,225) among those whose participation was not mandated (p < 0.001). The rates of nonmandated participation were higher (all p < 0.001) for academic than for non-academic radiologists (28.0% vs 11.3%), subspecialists than for generalists (17.0% vs 11.5%), and those in larger practice groups (< 10 members, 5.0%; 10-49 members, 12.6%; ≥ 50 members, 20.7%). State-level rates of nonmandated participation varied from 0.0% (South Dakota, Montana) to 32.6% (Virginia) and positively correlated with state population density (r = 0.315). CONCLUSION. Although diagnostic radiologists with time-limited certificates nearly universally participate in MOC, those with lifetime certificates (particularly general radiologists and those in smaller and nonacademic practices) participate infrequently. Low rates of nonmandated participation may reflect diplomate dissatisfaction or negative perceptions about MOC.

Spectroscopic, quantum chemical, molecular docking and in vitro anticancer activity studies on 5-Methoxyindole-3-carboxaldehyde

The FT-IR and FT-Raman spectra of 5-Methoxyindole-3-carboxaldehyde (MICA) molecule were recorded. The experimental and theoretical vibrational wavenumbers were assigned and compared. The non-linear optical (NLO) activity of the molecule was confirmed using second harmonic generation test and compared with theoretical result. The natural bond orbital (NBO) analysis was carried out to evaluate the intramolecular stabilization interactions of the molecule, which are responsible for the bio-activity of the molecule. The molecular electrostatic potential surface, frontier molecular orbitals and Fukui function analysis reveal the charge transfer interactions in the molecule. The total density of states (TDOS), partial density of states (PDOS), and overlap population density of states (OPDOS) studies were performed in order to visualize the molecular orbital contributions of the molecule. The molecular docking analysis was carried out to explore the inhibitory nature of the molecule, which indicates that molecule can acts as a novel inhibitor of lung cancer causing VEGF receptor. In addition, the in vitro cytotoxicity of the molecule confirms the anticancer activity against the human pulmonary epithelial lung cancer cell lines (A549). Hence, the present investigations pave the way for the development of lung cancer drugs.

Synthesis, Characterization, Crystal Structure, and DFT Study of 4-Bromo-2-(4,6-Dichloro-Phenylimino)-Phenol

The experimental crystal structure of a Schiff base compound 4-bromo-2-(4,6-dichloro-phenylimino)-phenol 1 is determined by single crystal X-ray diffraction and also characterized by FT-IR and 1H NMR spectroscopy. The electronic structure in the gas phase is studied by density functional theory (DFT) calculations.The theoretical results have good agreement with the data obtained from the crystallographic analysis. In addition, theoretical configurations which refer to the title compound are relaxed and studied in terms of the combined analysis of HOMO-LUMO energy gap, total density of states (DOS), partial density of state (PDOS), overlap population density of state (OPDOS), molecular electrostatic potential (MEP), NMR spectra, and harmonic vibrational frequencies.

Molecular docking, spectroscopic studies on 4-[2-(Dipropylamino) ethyl]-1,3-dihydro-2H-indol-2-one and QSAR study of a group of dopamine agonists by density functional method.

Density functional theory is one of the most popular accepted computational quantum mechanical techniques used in the analysis of molecular structure and vibrational spectra. Experimental and theoretical investigations of the molecular structure, electronic and vibrational characteristics of 4-[2-(Dipropylamino) ethyl]-1,3-dihydro-2H-indol-2-one are presented in this work. The title compound was characterized using FT-IR, FT-Raman and UV-Vis spectroscopic techniques. The results were compared with the theoretical calculations obtained using DFT/B3LYP with 6-311++G(d,p) as basis sets and was found to be in good agreement. The complete optimization of the molecular geometry of the title compound was carried out. Further, the vibrational assignments and calculation of potential energy distribution (PED) were reported. NLO has emerged as a key factor in recent researches. Materials showing nonlinear optical properties form the basis of nonlinear optics and development of such materials plays an important role in the present scenario. The current work provides sufficient justification for the title compound to be selected as a good non-linear optical (NLO) candidate. The electronic properties were reported using TD-DFT approach. The HOMO (EHOMO = -5.96 eV), LUMO (ELUMO = -0.80 eV) energies, energy gap and electrophilicity (2.22) was calculated in order to understand the stability, reactivity and bioactivity of the compound under investigation. To comprehend the bonding interactions we have performed the total (TDOS), partial (PDOS) and overlap population or COOP (Crystal Orbital Overlap Population) density of states. The drug likeness values were analyzed to evaluate the potential of the title compound to be an active pharmaceutical component. As a positive proof the paper further explains the molecular docking studies of the said compound. In addition, the stereochemistry of the protein structure was checked using Ramachandran plot. The title compound is a directly acting dopamine D2 agonist. In order to establish relationship between molecular descriptors of compound and its biological activity, QSAR studies have been done within the framework of DFT for 10 dopamine agonist including the title compound. Hence, the research exploration provides requisite information pertaining to the geometry, stability, reactivity and bioactivity of the compound through spectroscopic and quantum chemical methods.

Theoretical study on Sn–Sb-based lead-free solder by ab initio molecular dynamics simulation

Abstract

Spectroscopic (FT-IR, FT-Raman, UV–Vis), quantum chemical calculation and molecular docking evaluation of liquiritigenin: an influenza A (H1N1) neuraminidase inhibitor

The vibrational spectroscopic analysis of anti-influenza agent liquiritigenin (LGN) was performed using Fourier-transform infrared (FT-IR) and Fourier-transform Raman (FT-Raman) spectra. The experimental values of the LGN molecule was compared with vibrational frequencies obtained from the quantum chemical calculations using density functional theory (DFT) method employing 6-31G, 6-31G(d,p) and 6-311G(d,p) basis sets with scaled frequency, and these values are in good agreement with the computational one. The time-dependent density functional theory method was employed to compute the HOMO–LUMO energy gap of the LGN molecule and their differences were compared with transitions of UV-absorption spectra. The reactivity and selectivity of LGN were analyzed using parameters such as molecular electrostatic potential, global reactivity descriptors, Fukui functions and natural bond orbitals. The molecular orbital contributions were considered using the total, partial and overlap population density of states. The suitability of a drug candidate for human intake can be evaluated by absorption, distribution, metabolism, excretion and toxicity (ADMET) properties. The drug likeness and toxicity properties of LGN were confirmed with Lipinski’s rule of five and ADMET properties, respectively. The LGN molecule exhibits good bioactive score and less toxicity. A molecular docking analysis of LGN was carried out with influenza neuraminidase enzyme, and these results show that LGN has lowest binding affinity with inhibition constant when present in the active site.

Real-time measurement of dynamic evolution of absorption and emission properties of chromophores in single conjugated polymer molecules

Conjugated polymers have been widely used in optical sensors, light-emitting diodes and solar cells, due to their attractive optical and semiconducting properties. It is widely accepted that the optical and electrical properties of conjugated polymer molecules depend on the conjugated segments, i.e., chromophores in conjugated polymer molecule. The study of the evolution of the absorption and emission properties of single conjugated polymer molecules is essential to provide complementary information for the influence of conformation of conjugated polymer on its energy transfer process, as well as on the performance of optoelectronic devices based on conjugated polymers. Although the extensive studies have been reported to elucidate the optical properties of conjugated polymers with single molecule spectroscopy, simultaneous revealing their absorption and emission properties and their real-time evolution are rarely reported. In this paper, we simultaneously measure the absorption and emission properties of chromophores in single Poly[2,7-(9,9-dioctylfluorene)-&lt;i&gt;alt&lt;/i&gt;-4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole](PFO-DBT) conjugated polymer molecules and their real-time evolution by frequency-domain reconstructed defocused wide-field imaging. The emission dipole orientation of chromophore is achieved by applying defocused wide-field fluorescence imaging. The change of defocused patterns of individual polymer chain describes the angular distribution of emitted light and thus the emitting dipole orientation. Meanwhile, the absorption dipole orientation of chromophore in single conjugated PFO-DBT polymer molecule can be clarified in reconstructed frequency-domain imaging by modulating the relative phase of the pulse pairs and performing Fourier transform to the photoluminescence response. The population density of excited state of absorbing chromophore depends both on the relative phase between the ultrashort pulse pairs and on the orientation of absorption transition dipole moment of the chromophore. By extracting the frequency-domain information of fluorescence that is proportional to the population density of excited state, the evolution of absorption dipole orientation of chromophore can be derived. We distinguish three cases for the evolution of chromophores of single PFO-DBT conjugated polymer molecules: the absorption and emission chromophores both keep constant in single PFO-DBT conjugated polymer molecules; one of the dipole orientations of absorption and emission changes, while the other remains unchanged; both of them change simultaneously. The results may pave the way for the further understanding of the role of conformation in the energy transfer pathway in both natural and artificial light harvesting systems at nano- and micro-level.

Synthesis, characterization, crystal structure, and DFT study of 4-bromo-2-(4,6-dichloro-phenylimino)-phenol

The experimental crystal structure of a Schiff base compound 4-bromo-2-(4,6-dichloro-phenyl­imino)-phenol 1 is determined by single crystal X-ray diffraction and also characterized by FT-IR and 1H NMR spectroscopy. The electronic structure in the gas phase is studied by density functional theory (DFT) calculations.The theoretical results have good agreement with the data obtained from the crystallographic analysis. In addition, theoretical configurations which refer to the title compound are relaxed and studied in terms of the combined analysis of HOMO-LUMO energy gap, total density of states (DOS), partial density of state (PDOS), overlap population density of state (OPDOS), molecular electrostatic potential (MEP), NMR spectra, and harmonic vibrational frequencies.

Mechanical properties and chemical bonding of M2B and M2B0.75C0.25(M = Fe, Cr, W, Mo, Mn) compounds

Abstract

Emergency Medical Services Response Times to Motor Vehicle Crashes Increased over the Period 1987 to 2015

Emergency Medical Services (EMS) response time to motor vehicle crashes (MVC’s) have been studied to determine if reducing the individual components of EMS response time (notification, arrival at the crash scene, and hospital arrival) may affect survival rates. It has been proposed that a reduction to 1 and 15- minute EMS notification and arrival times at the crash would result in 1.84% and 5.2% fewer fatalities. The aim of this study was to analyze the changes in EMS response times (notification, arrival at the crash scene, and hospital arrival) over the past three decades, both individually and overall. An important change in the past three decades is the increased use of cellular phones. Therefore, we hypothesized that EMSnotification time would have decreased over the timeframe, yielding an overall decrease in EMS response time. Our data are based on the Fatal Accident Reporting System (FARS) using the variables: Time of Crash, EMS Notification Time, EMS Arrival Time, EMS Hospital Arrival Time. This gives a total of 248,981 valid cases following the implementation of our inclusion criteria and truncation of the dataset to the 99th percentile to eliminate unexplainable outliers. We computed the individual and overall median EMS response times for each year from 1987 to 2015. Additionally, we analyzed the response times based on four separate crash factors: weather, total vehicles involved, time of day, and state population density. From 1987 to 2015 the individual EMS response times changed; while notification time has decreased, the arrival at both crash scene and hospital have steadily increased, resulting in overall increased total EMS response time.

The Nexus of Statutory Allocation to the Public Water Sector and Population Density of Nigerian States

This paper posits that lack of maintenance, planning and bad governance including corruption led to the failure of the Nigerian public water supply system. A reconnaissance literature survey showed that virtually every city has decayed public taps and infrastructure causing most rural dwellers to trek long distances to obtain water for use with spurious quality. These are inspite of grants and interventions from international donors and credit agencies including the World Bank. Against this backdrop, an investigation was caused to examine the correspondence between financial allocation to the sector and every swelling population. Using analysis of variance for a test population of 20 states from the 36 states in Nigeria with data from National Bureau of Statistics and National Planning Commission, results showed that linearity of statutory allocation was positive with the population density of states with R2 values at &lt; 10%. Also, financial allocations to water supply over the period (1994 – 1996) were unstable occasioned by political and economic instability in the country. Further, the study observed that the epileptic water supply gave to private participation to provide portable drinking water which was hitherto alien to developing economies. The paper recommends that state governments should adopt a responsive model that will adjust allocations to water projects

The Nexus of Statutory Allocation to the Public Water Sector and Population Density of Nigerian States

This paper posits that lack of maintenance, planning and bad governance including corruption led to the failure of the Nigerian public water supply system. A reconnaissance literature survey showed that virtually every city has decayed public taps and infrastructure causing most rural dwellers to trek long distances to obtain water for use with spurious quality. These are inspite of grants and interventions from international donors and credit agencies including the World Bank. Against this backdrop, an investigation was caused to examine the correspondence between financial allocation to the sector and every swelling population. Using analysis of variance for a test population of 20 states from the 36 states in Nigeria with data from National Bureau of Statistics and National Planning Commission, results showed that linearity of statutory allocation was positive with the population density of states with R2 values at &lt; 10%. Also, financial allocations to water supply over the period (1994 – 1996) were unstable occasioned by political and economic instability in the country. Further, the study observed that the epileptic water supply gave to private participation to provide portable drinking water which was hitherto alien to developing economies. The paper recommends that state governments should adopt a responsive model that will adjust allocations to water projects

Private sector tuberculosis prevention in the US: Characteristics associated with interferon-gamma release assay or tuberculin skin testing.

ObjectiveTo determine whether latent tuberculosis infection risk factors are associated with an increased likelihood of latent tuberculosis infection testing in the US private healthcare sector.Data sourceA national sample of medical and pharmacy claims representing services rendered January 2011 through December 2013 for 3,997,986 commercially insured individuals in the US who were 0 to 64 years of age.Study designWe used multivariable logistic regression models to determine whether TB/LTBI risk factors were associated with an increased likelihood of Interferon-Gamma Release Assay (IGRA) or Tuberculin Skin Test (TST) testing in the private sector.Principal findings4.31% (4.27–4.34%) received at least one TST/IGRA test between 2011 and 2013 while 1.69% (1.67–1.72%) received a TST/IGRA test in 2013. Clinical risk factors associated with a significantly increased likelihood of testing included HIV, immunosuppressive therapy, exposure to tuberculosis, a history of tuberculosis, diabetes, tobacco use, end stage renal disease, and alcohol use disorder. Other significant variables included gender, age, asthma, the state tuberculosis rate, population density, and percent of foreign-born persons in a county.ConclusionsPrivate sector TST/IGRA testing is not uncommon and testing varies with clinical risk indicators. Thus, the private sector can be a powerful resource in the fight against tuberculosis. Analyses of administrative data can inform how best to leverage private sector healthcare toward tuberculosis prevention activities.

Spectroscopic investigation, hirshfeld surface analysis and molecular docking studies on anti-viral drug entecavir

Entecavir, a new deoxyguanine nucleoside analogue, is a selective inhibitor of the replication of the hepatitis B virus. In the present study, Quantum mechanical approach was carried out on the title compound to study the vibrational spectrum, the stability of the compound, the intermolecular and intramolecular interactions by using Density Functional Theory (DFT) with B3LYP 6-311++G(d,p) basis set. The B3LYP/DFT method was chosen because diverse studies have shown that the results obtained with it are in good agreement with those determined by other costly computational methods. The computational methods were aided by the experimental spectroscopic techniques, namely FTIR and FT Raman spectroscopies. The optimized molecular geometry, vibrational wavenumbers, infrared intensities and Raman scattering activities were calculated. The calculated HOMO and LUMO energies were found to be −6.397 eV and −1.504 eV which indicate the charge transfer within the molecule. The maximum absorption wavelength and the band gap energy of the title compound were obtained from the UV absorption spectrum computed theoretically. Natural Bond Orbital analysis has been carried out to explain the charge transfer (or) delocalization of charge due to the intra molecular interactions. The molecule orbital contributions are studied by using the total (TDOS), partial (PDOS), and overlap population (OPDOS) density of states. Molecular electrostatic potential (MEP), First order hyperpolarizability, Hirshfield surface analysis and Fukui functions calculation were also performed. From the calculations the first order hyperpolarizability was found to be 2.3854 × 10−30 esu. The thermodynamic properties (heat capacity, entropy, and enthalpy) of the title compound at different temperatures have been calculated. Molecular docking studies were made on the title compound to study the hydrogen bond interactions and the minimum binding energy was calculated.

Investigation of iron adsorption on composite transition metal carbides in steel by first-principles calculation

The nucleation potential of transition metal (TM) carbides formed in steel can be predicted by the behavior of iron adsorption on their surface. Therefore, Fe adsorption on the (001) surface of (A1-xmx)C (A = Nb, Ti, m = Mo, V) was investigated by the first-principles method to reveal the initialization of Fe nucleation. The Mulliken population and partial density of state (PDOS) were also calculated and analyzed in this work. The results show that Fe adsorption depends on the composition and configuration of the composite carbides. The adsorption energy (Wads) of Fe on most of (A1-xmx)C is larger than that of Fe on pure TiC or NbC. The maximum Wads is found for Fe on (Nb0.5Mo0.5)C complex carbide, indicating that this carbide has the high nucleation capacity at early stage. The Fe adsorption could be improved by the segregation of Cr and Mn atoms on the surfaces of (Nb0.5Mo0.5)C and (Ti0.5Mo0.5)C. The PDOS analysis of (Cr, Mn)-doped systems further explains the strong interactions between Fe and Cr or Mn atoms.

Hydrogen Adsorption on (5,0) and (3,3) Na-decorated BNNTs

The storage capacity of hydrogen on Na-decorated born nitride nanotubes (BNNTs) is investigated by using density functional theory within Quantum Espresso and Gaussian 09. The results obtained predict that a single Na atom tends to occupy above the central region of the hexagonal rings in (5,0) and (3,3) BNNT structures with a binding energy of -2.67 and -4.28 eV/Na-atom respectively. When a single H2 molecule is absorbed by a Na decorated BNNT, electrostatic field around Na atom and consequently charge of the participating atoms in the interaction region also undergo change. According to Mulliken population and partial density of state (PDOS) analyses, it is observed that positive charge carried by Na atom decreases.Another result of this charge transfer is revealed as an increase in the magnitude of the dipole moment of BNNT-Na-1H2 with respect to BNNT-Na. The results of charge density, separation distance of atoms in adsorption region as well as the H2 binding energy show the hydrogen molecule adsorption is a physical adsorption (physisorption). In the adsorption process, a single sodium atom with losing about 0.4e of its net charge can adsorb up to six H2 molecules with the binding energy of -0.35 and -0.32 eV/ H2 molecule on (5,0) and (3,3) BNNTs respectively. A comparison of the H2 binding energy of two nanotubes implies that the (5,0) BNNT-Na is more favorable for the hydrogen molecule adsorption.