Knowledge and Economic Growth: Evidence from Some Developing Countries

The purpose of this paper is to estimate the impact of Knowledge Index consist of R&D, human resources and diffusion of ICT on economic growth in developing countries. To do so we have used a sample of 16 developing countries for which the necessary data were available for the period 2000- 2008. In this paper knowledge economy index (R&D, human resources and diffusion of ICT), Investment (Gross fixed capital formation), general government consumption and labor force considered as explanatory variables and GDP as a dependent variable. Our findings based on panel data econometrics method indicate that the impact of knowledge index on economic growth in the countries under consideration is positive and significance. Therefore, the expansion of knowledge in these countries is suggested

Mites of the genus Anomaloppia Subías (Acari: Oppiidae) from Alborz province, northern Iran, with one new species and a key to the known species

In the course of a faunistic survey on oribatidmites in Alborz province, northern Iran, four species belonging to the genus Anomaloppia were collected: A. iranica, A. mazandaranica, A. differens and a hitherto unknown species which is named as A. alborzi sp. n. The new species is characterized by the rostral setae which are situated close to each other and by long sensilli, with a fusiform head and four long barbs and by smooth notogastral setae. Anomaloppia differens is recorded for the first time from Iran and a supplementary description is provided for this species on the basis of Iranian materials. An identification key to the species of Anomaloppia is given

Wettability of fully hydroxylated and alkylated (001) α-quartz surface in carbon dioxide atmosphere

Wettability of alkylated quartz surfaces is of primary importance in several technological applications, including the development of oil and gas reservoirs and carbon geo-sequestration. It is intuitively understood and experimentally confirmed that hydroxylated quartz surfaces are hydrophilic. By gradually saturating a hydroxylated (001) α-quartz surface with pentyl groups, we show using molecular dynamics simulations that the surface can also exhibit extreme hydrophobicity. Within a range of surface pentyl group density from 0.29 to 3.18/nm2, the contact angle of a water droplet under 10 MPa pressure of carbon dioxide at 300 K changes from 10–20 to 180°. This study has shown that a complete description of wettability of alkylated quartz surfaces requires three contact angles—one at the tip level of pentyl groups and two at the level of the quartz surface. The latter two are the contact angle of the spherical droplet and the hidden contact angle of a water “skirt” formed between the tip level of pentyl groups and the quartz surface. Analysis of the hidden contact angle unveils a binary wettability, where the surface relatively abruptly transforms from hydrophilic (the contact angle is less than 90°) to hydrophobic (the contact angle is 180°) with an increase in surface pentyl group concentration

Neutron scattering: A subsurface application review

Geomaterials and filling fluids properties that are pertinent to a geologic porous media can be characterized using a range of methods, such as nuclear magnetic resonance, X-rays, infrared spectroscopy, and neutron scattering (NS). In this context, NS features as an important tool elucidate key properties of a porous medium, which has recently gained significant attention. Key rock properties that can be measured by NS include: rock texture (i.e. crystallographic preferred orientation), mechanical properties (i.e. stress and strain) as well as porous medium properties (pore porosity, pore size and connectivity). In addition, NS imaging can help elucidate the phase behaviour of confined reservoir fluids in rock matrix under prevailing pressures and temperatures. Thus, a precise characterization of these properties (amongst other multiphase flow attributes) is critical for several applications in varied fields such as hydrocarbon reservoirs, geothermal systems, crystallography, geomechanics and geochemistry. Low neutron attenuation by most substances (deep sample penetration) and strong neutron attenuation by hydrogen are essential features of neutrons that allow NS to collect high-quality data across a wide variety of subsurface conditions. These features enable NS to be ideally suited to some applications as compared to other techniques such as X-rays and magnetic resonance imaging (MRI). For example, X-rays may not have sufficient resolutions for examining nanopore structures and confined fluids. Contrastingly, MRI is limited by the visualization of a range of pore sizes. However, NS can capture angstrom-to-micron-scale information of atomic to meso-to-macro-scale structures of rocks and fluids (i.e. hydrogen-rich fluids) inside a porous medium. These insights are vital for predictive reservoir models, where meaningful reservoir-scale (hectometre-scale) predictions can be performed. However, when compared to X-rays, neutrons have weak sources and/or low signals; therefore, experimental time can be quite long and samples need to be relatively large. Other limitations of NS (some may be also true of other techniques) include problems like accessing neutron sources (e.g. complicated nuclear processes for neutron production and small number of available instruments when compared to X-rays), high costs, and the strong absorption of neutron signals by some elements [e.g. cadmium (Cd), boron (B), and gadolinium (Gd)]. Despite the potential of NS, a review that considers key NS subsurface applications, limitations, and outlooks is currently lacking. Thus, in this review, we describe the basic concepts, experiments, methods, requirements, restrictions, and applications of NS for rock and fluid characterization. This study finds that despite its overall challenges, NS is a promising technique for characterizing subsurface rock and fluid systems, opening diverse avenues for future technological and scientific research within this area