Male-female literacy differential in India--1981     

Sagar P 《Population geography : a journal of the Association of Population Geographers of India》1989,11(1-2):21-39

The author examines inequalities in the literacy rates between males and females in India. Regional variations in literacy are examined by district using maps. "The male-female literacy differential is low in coastal, peripheral and metropolitan areas and is high in inland and mountainous areas. These regional disparities are the product of differences in length of educational background, age at marriage, level of urbanisation, standard of living and proportion of socially conservative and backward sections of society.... The study in spatial dimension provides a strong base for the removal of sex biased discrimination in society."  相似文献   

Physical and optical characteristics of atmospheric aerosols during ICARB at Manora Peak,Nainital: A sparsely inhabited,high-altitude location in the Himalayas     

U. C. Dumka  K. Krishna Moorthy  P. Pant  P. Hegde  Ram Sagar  K. Pandey 《Journal of Earth System Science》2008,117(1):399-405

Collocated measurements of the optical and physical properties of columnar and near-surface aerosols were carried out from Manora Peak, Nainital (a sparsely inhabited, high altitude location, ～2 km above mean sea level, in the Himalayas), during the Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB) under the Geosphere Biosphere Programme of the Indian Space Research Organization (ISRO-GBP). Under this, observational data of spectral aerosol optical depths (AOD), mass concentration of aerosol black carbon (M _B ), mass concentration (M _T ) and number concentration (N _t ) of composite (total) aerosols near the surface and meteorological parameters were collected during the period February 15 to April 30, 2006. Though very low (<0.1 at 500 nm) AODs were observed during clear days, as much as a four-fold increase was seen on hazy days. The Ångström exponent (α), deduced from the spectral AODs, revealed high values during clear days, while on hazy days α was low; with an overall mean value of 0.69 ± 0.06 for the campaign period. BC mass concentration varied between 0.36 and 2.87 μg m^?3 and contributed in the range 0.7 to 1.8% to the total aerosol mass. Total aerosol number concentration and BC mass concentration showed diurnal variation with a midnight and early morning minimum and a late afternoon maximum; a pattern quite opposite to that seen in low altitude stations. These are attributed to the dynamics of the atmospheric boundary layer.  相似文献   

Broad-band optical polarimetric study of IC 1805     

Biman J. Medhi  G. Maheswar  K. Brijesh  J. C. Pandey  T. S. Kumar  R. Sagar 《Monthly notices of the Royal Astronomical Society》2007,378(3):881-887

We present the BVR broad-band polarimetric observations of 51 stars belonging to the young open cluster IC 1805. Along with the photometric data from the literature, we have modelled and subtracted the foreground dust contribution from the maximum polarization ( P _max) and colour excess [ E ( B − V )]. The mean value of the P _max for intracluster medium and the foreground are found to be 5.008 ± 0.005 and 4.865 ± 0.022 per cent, respectively. Moreover, the mean value of the wavelength of maximum polarization (λ_max) for intracluster medium is 0.541 ± 0.003 μ m, which is quite similar as the general interstellar medium (ISM). The resulting intracluster dust component is found to have negligible polarization efficiency as compared to interstellar dust. Some of the observed stars in IC 1805 have shown the indication of intrinsic polarization in their measurements.  相似文献   

CCD photometric and mass function study of nine young Large Magellanic Cloud star clusters     

B. Kumar  R. Sagar  J. Melnick 《Monthly notices of the Royal Astronomical Society》2008,386(3):1380-1397

We present a CCD photometric and mass function study of nine young Large Magellanic Cloud star clusters, namely NGC 1767, 1994, 2002, 2003, 2006, SL 538, NGC 2011, 2098 and 2136. BV RI data, reaching down to   V ∼ 21  mag, were collected from the 3.5-m NTT/EFOSC2 in subarcsec seeing conditions. For NGC 1767, 1994, 2002, 2003, 2011 and 2136, broad-band photometric CCD data are presented for the first time. Seven of the nine clusters have ages between 16 and 25 Myr, and the other two have ages of  32 ± 4 Myr  (NGC 2098) and  90 ± 10 Myr  (NGC 2136). For the seven youngest clusters, the age estimates based on a recent model and the integrated spectra are found to be systematically lower (∼10 Myr) than the present estimates. In the mass range  ∼2–12 M_⊙  , the mass function slopes for eight out of nine clusters were found to be similar, with the value of γ ranging from  −1.90 ± 0.16  to  −2.28 ± 0.21  . For NGC 1767 the slope is flatter, with  γ=−1.23 ± 0.27  . Mass segregation effects are observed for NGC 2002, 2006, 2136 and 2098. This is consistent with the findings of Kontizas and colleagues for NGC 2098. The presence of mass segregation in these clusters could be an imprint of the star formation process, as their ages are significantly smaller than their dynamical evolution time. The mean mass function slope of  γ=−2.22 ± 0.16  derived for a sample of 25 young (≤100 Myr) dynamically unevolved Large Magellanic Cloud stellar systems provides support for the universality of the initial mass function in the intermediate-mass range  ∼2–12 M_⊙  .  相似文献   

A general approach for porosity estimation using artificial neural network method: a case study from Kansas gas field   总被引：1，自引：0，他引：1  

Sagar Singh  Ali Ismet Kanli  Selcuk Sevgen 《Studia Geophysica et Geodaetica》2016,60(1):130-140

This study aims to design a back-propagation artificial neural network (BP-ANN) to estimate the reliable porosity values from the well log data taken from Kansas gas field in the USA. In order to estimate the porosity, a neural network approach is applied, which uses as input sonic, density and resistivity log data, which are known to affect the porosity. This network easily sets up a relationship between the input data and the output parameters without having prior knowledge of petrophysical properties, such as porefluid type or matrix material type. The results obtained from the empirical relationship are compared with those from the neural network and a good correlation is observed. Thus, the ANN technique could be used to predict the porosity from other well log data.  相似文献   

澜沧江和怒江流域的气候变化及其对径流的影响     

刘苏峡丁文浩  莫兴国王盛  刘昌明罗贤  何大明Sagar Ratna Bajracharya Arun Bhakta Shrestha Nand Kishor Agrawal 《气候变化研究进展》2017,13(4):356-365

采用VIP（Vegetation Interface Processes）模型和HIMS（Hydro-Informatic Modeling System）模型,模拟分析了1957-2012年澜沧江和怒江流域（简称两江流域）水资源量的演变。根据CMIP5 RCP2.6,RCP4.5和RCP8.5情景预测,模拟了2030年代和2050年代流域水资源的变化。研究发现,过去50年间,两江流域的气温都呈升高趋势,但海拔较高的上游地区升幅大于下游。年总降水量的变化趋势不明显,但春季降水增加趋势明显。两江流域年总水资源量为650亿～ 850亿m3,水资源总量长期变化趋势不明显,其中澜沧江的波动性（1.884,最大与最小之比）大于怒江。空间上水资源量呈现北低－南高的格局。在未来,两江流域气温仍呈增加趋势,降水呈增加趋势,径流呈增加趋势,空间变异性趋小,但较强的季节性变化对水资源安全仍具有较大的挑战性。  相似文献   

Groundwater contamination in parts of Nalgonda district,Telangana, India as revealed by trace elemental studies     

D. Purushotham  D. Linga  Netramani Sagar  Sibasish Mishra  G. Naga Vinod  K. Venkatesham  K. Saikrishna 《Journal of the Geological Society of India》2017,90(4):447-458

The present paper deals with major and trace elements geochemistry of the groundwater from Nalgonda district, Telangana. The study area is very important in terms of anthropogenic activity like rapid industrial, urban development, pesticides, pharmaceutical, granite polishing and agro based industries. Inductively coupled plasma mass spectrometer (ICPMS) was employed to determine the concentration of trace elements in collected groundwater samples (bore well). These probe elements were further categorized as toxic elements (Pb, As, Cd, and V), alkaline earths (Sr and Ba), alkali metals (Li, Rb), transition metals (Cr, Mo and Ni), metallic elements (Cu, Fe, Zn, Al, Co), and other non-metallic elements (Se and Si). The groundwater quality was examined in perspective of Indian as well as World Health Organization drinking water standards. Based on the analytical results, groundwater in the study area is found to be slightly alkaline in nature and very hard, the average abundance of the major cations and anions is in the order of Ca⁺<Na⁺<Mg⁺<K⁺ and Cl^-<HCO₃ ^?<CO₃ ^?<SO₄ ^?<NO₃ ^?<F^– respectively. The dominant hydro chemical facies of groundwater is Na⁺ - HCO ₃ ^– – Cl^– and Na⁺ - Cl^– – HCO^– ₃ types.The results of trace elements shows that concentration of Pb, As, Cd, V in collected samples exceeding the desirable limits, and in the case of alkaline, alkali, transition, non-metallic elements, seventy per cent of the samples crossed the desirable limits, but all metallic elements viz. Cu, Fe, Zn, Al, Co is within the limits as per Indian as well as World Health Organizations drinking water standards. Factor analysis results shows that seven factors emerged as a significant contributor to the groundwater contamination is about 65.32 per cent. The spatial variation maps decipher trace elemental concentrations both geogenic and anthropogenic origin, by three zones i.e. ‘low’, ‘moderate’ and ‘high’ of the study area based on environment using Arc-GIS. High concentrations of trace elements are indicative of phenomenal rise in chemical composition and likely to have its origin from silicate weathering reactions and dissolution/precipitation processes supported by rainfall and anthropogenic activities, indiscriminate use of fertilizers/pesticides, and disposal of waste and sewage, release of reactive pollutants into the atmosphere by industries. Hence, this work is of immense societal benefit in terms of prevailing human health hazards in the study area with a direct relevance to such industrially populated regions elsewhere.  相似文献   

Multiband optical monitoring of the blazars S5 0716+714 and BL Lacertae     

C. S. Stalin  Gopal-Krishna  Ram Sagar  Paul J. Wiita  V. Mohan  A. K. Pandey 《Monthly notices of the Royal Astronomical Society》2006,366(4):1337-1345

  相似文献   

Study of the galactic cluster NGC 6823     

Ram Sagar  U. C. Joshi 《Astrophysics and Space Science》1981,75(2):465-472

PhotoelectricUBV magnitudes have been determined for 41 stars in NGC 6823. The reddening across the cluster field is determined and found that it varies fromE(B-V)=0.60 to 1.16 mag. The true distance modulus to the cluster is estimated at 12.7±0.3 mag. It is found that cluster stars are not co-equal in age.  相似文献   

Stellar contents and star formation in the young cluster Stock 18     

Himali Bhatt  Ram Sagar J.C. Pandey 《New Astronomy》2012,17(2):160-166

We have carried out deep (V ∼ 21 mag) UBVRI photometric study of the star cluster Stock 18. These along with archival Infrared data have been used to derive the basic cluster parameters and also to study the star formation processes in and around the cluster region. The distance to the cluster is derived as 2.8 ± 0.2 kpc while its age is estimated as 6.0 ± 2.0 Myr. Present study indicates that interstellar reddening is normal in the direction of the cluster. The mass function slope is found to be −1.37 ± 0.27 for the mass range 1 < M/M_⊙ < 11.9. There is no evidence found for the effect of mass segregation in main-sequence stars of the cluster. A young stellar population with age between 1-2 Myr have been found in and around the cluster region. The presence of IRAS and AKARI sources with MSX intensity map also show the youth of the Sh2-170 region.  相似文献