893 research outputs found
Below replacement-level fertility in Iran: progress and prospects
In 1996, four provinces of Iran experienced below replacement level fertility. Since the early 1980s, these provinces have recorded lower fertility than the national level. How and under what condition has fertility declined to such a low level in these provinces? It may be of considerable interest to examine whether these provinces can be regarded as the leaders of the fertility transition in Iran. What are the likely effects of below-replacement fertility on population growth in Iran in the short term? Will Iran, as a whole, experience below replacement fertility in the near future? What would be the reaction of the government if below-replacement level fertility is reached in the near future? This paper will first, assess and analyse the fertility trends in the provinces of Isfahan, Gilan, Semnan and Tehran as compared with the national level during the period 1972-1996. Using available data, an attempt will also be made to estimate recent fertility levels for these provinces. Second, demographic and socio-economic characteristics, as well as contraceptive use, in these provinces will be reviewed; female singulate mean age at marriage and age-specific proportions married for 1976, 1986 and 1996 will then be examined. Third, the prospects of low fertility in Iran as well as the likely reaction of the government on low fertility will be discussed thereafter
Women\u27s Human Capital and Economic Growth in the Middle East and North Africa
The process of demographic transition has increased the share of the working-age population in Middle East and North Africa (MENA). This situation has created an opportunity for economic growth, called the demographic dividend. Global comparisons show that a favorable age structure has not always resulted in a boost in economic growth. In order to take a full advantage of the MENA’s demographic dividend, it is important to identify different factors contributing to economic growth in this region. Investment in women’s human capital is expected to have important implications for the region’s economic growth and for maximizing the benefits created by the demographic dividend. Using a range of data sources, this paper aims to determine the association between women’s human capital (measured by adult educational attainment and health status) and economic growth (measured by gross national income per capita) in MENA. The findings show a positive association between these two. Specifically, the national-level income is generally higher in countries with lower maternal mortality and higher female literacy, female tertiary education, female life and healthy life expectancies at birth and professional childbirth attendance. Thus, investment in women’s human capital can accelerate the pace of development in MENA
Selective Toxicity of Persian Gulf Stonefish (Pseudosynanceia Melanostigma) Venom on Human Acute Lymphocytic Leukemia B Lymphocytes
Persian Gulf Stonefish (Pseudosynanceia melanostigma) is one of the poisonous fish which is naturally found in Indian Ocean and Persian Gulf. The venom, which is isolated from this species, is suspected to use as an anticancer agent. In this study, we showed the cytotoxic effect of stonefish crude venom on lymphocytes, which obtained from acute lymphoblastic leukemia (ALL) patients and normal donors. Our results demonstrated that crude venom of Persian Gulf Stonefish could affect cancerous lymphocytes by reactive oxygen species (ROS) generation and mitochondrial membrane damage without any significant effect on normal cells.Highlights Persian Gulf Stonefish (Pseudosynanceia melanostigma) is one of the poisonous fishThis venom is composed of various proteins with cardiotoxic and the hemolytic activityCrude venom of Persian Gulf Stonefish can affect cancerous lymphocytes by ROS generation
Severe Dyspnea due to Pulmonary Metastasis of Renal Cell Carcinoma: Is Cytoreductive Surgery of Value?
Here, we present a case in which cytoreductive surgery, like left radical nephrectomy, was effective in the treatment of pulmonary metastases and para-aortic metastases from renal cell carcinoma. A 28-year-old man underwent left radical nephrectomy with pulmonary metastasectomy for the diagnosis of metastatic left renal cell carcinoma. The histologic diagnosis was clear cell carcinoma G2, pT3N1M1. He subsequently underwent i.m. administration of IFN-α, 5 million units per day for 30 days. The nasal oxygen mask was weaned gradually, and the chest tube was removable due to cessation of the continuous production of pleural fluid. The patient was well until one year after operation
A CFD and experimental approach for simulating the coupled flow dynamics of near wellbore and reservoir
The modeling of simultaneous flow behavior through a reservoir and wellbore is important
and an integrated model is needed which accounts for the transient multiphase flow in the
wellbore and its surrounding region. In addition, reservoir and wellbore interface modeling
and cost-effective Computational Fluid Dynamics (CFD) methodology are required to
simulate the flow behavior in that region.
The study outlines the development of an experimental prototype to study multiphase
flow in the near wellbore region. To the best of my knowledge, this facility has the capability
to accommodate a larger length scale compared to similar facilities available in
the research organizations. This experimental setup can be used for investigating a wide
variety of multiphase flow problems which have been considered in the present research.
A CFD methodology has been developed using the 3D Navier-Stokes equations to simulate
an integrated wellbore-reservoir flow. The CFD methodology has been verified for the
fluid flow mechanism at near wellbore. The simulation results have been compared to the
analytical solutions. Then, this model is extended to establish a coupled wellbore-reservoir
framework which is based on 3D Navier-Stokes equations. The simulations have been performed
to validate the newly developed CFD algorithm and various scenarios of a reservoir
have been taken into consideration. The same process has been applied to investigate flow
through a perforated tunnel and a new method of perforation has been discussed. The study
indicates standard CFD techniques use a “numerical approach” such as the volume of fluid accounts for capillary pressure and surface tension force needs to be improved for more
understanding of the flow through porous media. In this regards, Allen-Chan phase-field
method has been combined with the Navier-Stokes equations to simulate multiphase flow
in porous media. The simulations performed with the phase-field method have been verified
with the experimental data. The experimental and CFD approach of this thesis make
a unique contribution in the field of the petroleum industry and multiphase flow in porous
media
Integrated optical filters using Bragg gratings and resonators
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.Includes bibliographical references (p. [207]-213).This thesis provides an in-depth study of optical filters made using integrated Bragg gratings and Bragg resonators. Various topologies for making add/drop filters using integrated gratings are outlined. Each class of devices is studied in detail and the theoretical tools needed for designing the add/drop are developed. First-order filters using Bragg resonators do not meet WDM add/drop filter specifications. Consequently, schemes to design higher-order filters are derived. The relative advantages and disadvantages of the various possiblities are outlined. Preliminary integrated Bragg grating devices, in InP, were designed using the tools developed. The fabricated devices were measured. The measurements revealed low-loss structures with a 40, 000. Measurements on higher-order inline coupled Bragg resonator filters showed flat-top and fast roll-offs. The results of the measurements and comparison with the theory are presented for the various devices. The results reveal that Bragg grating based devices offer tremendous potential for use as add/drop filters in WDM systems.by Mohammad Jalal Khan.Ph.D
Numerical simulation of miscible fluid flows in porous media
The study of miscible
ow in porous media is an important topic in many disciplines
of science and engineering, especially in the field of petroleum engineering.
For example, Carbon dioxide (COâ‚‚) may be injected into an oil reservoir in order
to improve the oil recovery rates, which is called enhanced oil recovery (EOR). This
thesis focuses on the study of a miscible displacement of two
fluids, such as COâ‚‚ and
oil, in a porous medium. An upscaling methodology for modeling multiscale features
of the
ow and the porous medium has been studied, where the overall pressure drag
and skin friction exerted on the porous medium has been modelled by combining the
Darcy's law with a statistical mechanical theory of viscosity, which is an important
contribution of this thesis.
A numerical methodology for capturing the multiphysics and multiscale nature
of the governing motion has been studied. The temporal discretization employs the
second order Crank-Nicolson scheme for viscous and diffusive phenomena, and an
explicit method for all other terms. The nonlinear advection terms in the momentum
equation has been treated with an Euler explicit
flux form central finite difference
method; however, the advection of the CO2 mass
flux has been treated with a streamline
based Lagrangian method. In order to implement the Marker-and-Cell (MAC)
scheme for resolving the incompressibility, a staggered arrangement of the velocity
and pressure has been presented on a collocated grid. This approach enhances the
implementation of a multigrid solver, and is a novel computational model for simulating
miscible displacement processes. The performance of the Lagrangian method
has been assessed with respect to an equivalent
flux form upwind method.
The results indicate that the viscous forces play a signicant role compared to the
effect of permeability on miscible displacement of COâ‚‚ and oil, where the injected COâ‚‚ displaces the residual oil without being distorted, thereby enhancing the recovery
of hydrocarbon. Although the present results with an idealized model lacks from
verifications with field measurements, findings of this thesis provide useful feedback
to further investigations on COâ‚‚ based EOR techniques
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