440 research outputs found
Measuring Financial Development in the Middle East and North Africa: A New Database
This paper develops a methodology to construct detailed indices of financial sector development across countries and uses it to create a new panel database of finan-cial sector development in Middle East and North Africa (MENA) countries. It combines existing quantitative data with information from comprehensive surveys undertaken in 2000-01 and 2002-03. The data show that some MENA countries have relatively well-developed banking sectors and regulatory and supervisory regimes. However, across the region, the nonbank financial sectors and sup-porting institutions are in need of reform. The MENA region ranks far behind industrialized countries and East Asia in financial sector development. Copyright 2006, International Monetary Fund
Predictable Models and Experimental Measurements for Electric Properties of Polypropylene Nanocomposite Films
This paper processed and characterized cost-fewer polypropylene (PP) nanocomposite films; an experimental work has been investigated for studying the electric properties of the new nanocomposite materials and compared with unfilled industrial materials in a frequency range up to 1 kHz. A small addition of nanoparticles (clay, and fumed silica) to polypropylene showed appreciable improvement in the electric reactance and conductance at different frequency up to 1kHz, in addition, an electric spectroscopy has been measured the electric properties of polypropylene with and without nanoparticles under variant temperatures (20°C, and 60°C). Cambridge Engineering Selector (CES) program were carried out the electrical/mechanical predictable models for the suggested materials. Finally, this paper leads to synthesize electrical insulating polypropylene nanocomposite films where the electrical properties are properly maintained in order to achieve more cost-effective, energy-effective and hence environmentally better materials for the electrical insulation technology
Vaccination of biological cellulose fibers with glucose: A gateway to novel nanocomposites
This work introduces, for the first time worldwide, the means to preserve and protect the natural nanoporous structure of the never-dried plant cell wall, against the irreversible collapse, which occurs due to drying. Simultaneously, these means, used for the above-mentioned aim, provide a gateway to novel nanocomposite materials, which retain the super reactive and super absorbent properties of the never-dried biological cellulose fibers. The present work showed, for the first time worldwide, that glucose can be vaccinated into the cell wall micropores or nanostructure of the never-dried biological cellulose fibers, by simple new techniques, to create a reactive novel nanocomposite material possessing surprising super absorbent properties. Inoculation of the never dried biological cellulose fibers, with glucose, prevented the collapse of the cell wall nanostructure, which normally occurs due to drying. The nanocomposite, produced after drying of the glucose inoculated biological cellulose, retained the super absorbent properties of the never dried biological cellulose fibers. It was found that glucose under certain circumstances grafts to the never dried biological cellulose fibers to form a novel natural nanocomposite material. About 3-8% (w/w) glucose remained grafted in the novel nanocomposite
Advanced nano-based manipulations of molasses in the cellulose and paper discipline: Introducing a master cheap environmentally safe retention aid and strength promoter in papermaking
This work introduces, for the first time worldwide, molasses – a byproduct of the sugar industry – as a master retention aid and strength promoter in papermaking. The paper nanocomposites produced in the present work – involving molasses, natural cellulose fibers, and kaolin – retained larger amounts of kaolin while exhibiting greater strength, as compared to their molasses-free counterparts. Recently, the authors have shown, for the first time, that the nanoadditive sucrose can overcome the ultimate fate of deterioration in strength of paper, due to addition of inorganic fillers such as kaolin. This deterioration was counteracted by incorporating the nanoporous structure of cellulose fibers with sucrose, which leads to incorporation beating of the fibers, and thus increases the strength of the produced paper nanocomposites. In addition, the nanoadditive sucrose was proven – for the first time – to act as retention aid for inorganic fillers such as kaolin. We called this phenomenon incorporation retention to differentiate it from the conventional types of retention of inorganic fillers. On the other hand, it is well established in the literature that using gums (including starch) as additives in papermaking enhances the strength of paper. Molasses contains both the nanoadditive (sucrose), and gums (including starch). Molasses is a byproduct of sugar industry, which is cheaper than sucrose; and a major part of sucrose lost in sugar industry resides in molasses. Moreover, molasses is an environmentally safe additive. Therefore, the nanoadditive (molasses) was chosen, in the present work, to be manipulated as a master strength promoting retention aid for inorganic fillers used in papermaking, such as kaolin
Design modern structure for heterojunction quantum dot solar cells
This paper proposal new structure for improving the optical, electrical characteristics and efficiency of 3rd generation heterojunction quantum dot solar cell (HJQDSC) (ITO/CdS/QDPbS/Au) model by using the quantum dot window layer instead of bulk structure layers cell. Also, this paper presents theoretically analysis for the performance of the proposal HJQDSC (ITO/QDCdS/QDPbS/Au) structure. The new design structure was applied on traditional (SnO2/CdS/CdTe/Cu) and (ZnO/CdS/CIGS/Mo) thin film solar cells which based on sub-micro absorber layer thickness models by replacing the bulk CdTe, CIGS absorber layers and CdS window layer with quantum dot size materials to achieve higher efficiency with lesser usage layer material. Also, it has been studied the effect of using semiconductors layers in quantum dots size on electric and optical properties of thin film solar cells and the effect of window and absorber layers quantum dots radii on the performance of solar cells. Finally, a thermal efficiency analysis has been investigated for explaining the importance of new structure HJQD solar cells
MICROBICIDAL AND CYTOTOXIC ACTIONS OF METHANOLIC CRUDE EXTRACTS OF A. MULTIFLORA.-ROXB
Objective: The study presented here was carried out for the evaluation of microbicidal and cytotoxic potential of methanolic extract of leaves of Ammannia multiflora. The microbicidal activity was tested against 16 bacteria. The cytotoxic activity was tested against brine shrimp species Artemia salina.
Methods: The microbicidal effect of the plant extracts was tested in vitro by the disc diffusion method with 16 standard bacterial strains. Artemia salina; a brine shrimp species; was used to assess cytotoxic activity.
Results: Among the subjected 16 different bacteria; in case of S. boydii; the zone of inhibition was higher (22.0 mm) at 500 µg/ml concentration. Whereas in the case of E. foecalis, the zone of inhibition was higher (8.0 mm) at 250 µg/ml concentration. In S. pyogenes; zone of inhibition was higher at 500 µg/ml concentration (13.0 mm). The growth of S. saprophyticus (9 mm), S. agalactiae (7 mm) and S. sonnei (7 mm) was also moderately inhibited. The extract exhibited effectiveness against 7 different species of bacteria out of 16. Cytotoxic effect was determined in lethality bioassay of brine shrimp species Artemia salina. The plant extracts exhibited significant cytotoxic property which was reflected in LC50 and LC90values of 20.42µg/ml and 229.09 µg/ml respectively. Cytotoxic property was found as dose dependent manner.
Conclusion: These results suggest that, Ammania multiflora can effectively be used for its significant microbicidal action. It is also effective as cytotoxic agent and thus, could justify its use in traditional medicine
Returns to International Migration: Evidence from a Bangladesh-Malaysia Visa Lottery
We follow 3,512 (of 1.4 million) applicants to a government lottery that randomly allocated visas to Bangladeshis for low-skilled, temporary labor contracts in Malaysia. Most lottery winners migrate, and their remittance substantially raises their family’s standard of living in Bangladesh. The migrant’s absence pauses demographic changes (marriage, childbirth, household formation), and shifts decision-making power towards females. Migration removes enterprising individuals, lowering household entrepreneurship, but does not crowd out other family members’ labor supply. One group of applicants were offered deferred migration that never materialized. Improved migration prospects induce pre-migration investments in skills that generate no returns in the domestic market
The Productivity Consequences of Pollution-Induced Migration in China
Migration and pollution are two defining features of China\u27s impressive growth performance over the last 30 years. In this paper we study the migration response to pollution in Chinese cities, and its consequences for productivity and welfare. We document a robust pattern in which skilled workers emigrate more in response to pollution than the unskilled. Their greater sensitivity to air quality holds up in cross-sectional variation across cities, panel variation with individual fixed-effects, and when instrumenting for pollution using distant power-plants upwind of cities, or thermal inversions that trap pollution. Pollution therefore changes the spatial distribution of skilled and unskilled workers, which results in higher returns to skill in cities that the educated migrate away from. We quantify the loss in aggregate productivity due to this re-sorting by estimating a model of demand and supply of skilled and unskilled workers across Chinese cities. Counterfactual simulations from the estimated model show that reducing pollution would increase productivity through spatial re-sorting by approximately as much as the direct health benefits of clean air. Physical and institutional restrictions on mobility exacerbate welfare losses. People\u27s dislike of pollution explains a substantial portion of the wage gap between cities
Is Habit a Powerful Policy Instrument to Induce Prosocial Behavioral Change?
Recent literature suggests the power of interventions to change habits. In a dense slum in Nairobi, we adopt best practices from the habit literature to encourage toilet use instead of alternatives that damage community health. Offering subsidies increased toilet usage, effects continue for one month after discounts end, but erode thereafter. Treatments designed to induce habit formation (marketing, time-limited discounts encouraging repetition, discounts for longer periods, targeting `habitual types’) generated no greater persistence. We see some persistent behavior change due to learning about the new toilet option. It appears difficult to induce pro-social behavior without private benefits through habit change
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