Exploring the future impacts of urbanization and climate change on groundwater in Arusha,Tanzania

ABSTRACT

We combine satellite imagery, urban growth modelling, groundwater modelling and hydrogeological field expeditions to estimate the potential impacts in 2050 of rapid urbanization and climate change on groundwater in Arusha, Tanzania, and by extension similar areas in Sub-Saharan Africa. Our analysis suggests that a reduction of groundwater recharge by 30–44% will cause groundwater levels to drop by up to 75 m, mainly due to increased evapotranspiration and to an expansion in paved surface. If this scenario becomes reality, we predict that wells will run dry, creating health, social and environmental risks.     

Computer Aided Model for Casting Aluminium Using Die-Casting

Computer aided casting of aluminum using die-casting was developed. A piston, which is an automobile part and very important in internal combination engine, was chosen for the research. Pistons are made of aluminum alloy. Models of the products were developed to aid the casting process. Mathematical models that show the dimensions of the casting were also developed. Since the project is about using computer to aid casting process, a program using visual basic （VB） Language was developed. The program was used to incorporate die-casting process into computer system. The written program was tested and the model of the casting product （piston） was displayed. The result shows that computer which is faster with accurate result can be used as an aid in the production of aluminum piston using die-casting process, for accurate planning in the manufacture of the product.     

Effect of CdO addition on photon,electron, and neutron attenuation properties of boro-tellurite glasses

This research article aims to study the effect of CdO addition on the radiation shielding characteristics of boro-tellurite glasses in the composition of 50B₂O₃ - (50-x) TeO2- xCdO, where x = 0, 10, 20, 30, 40 and 50 mol%. These glasses were exposed to gamma radiation and the transmitted gamma photons were evaluated for energies varying from 15 keV to 15 MeV using Geant4 simulation toolkit. The number of transmitted photons was then used to characterize the gamma shielding for the studied glasses in terms of linear/mass attenuation coefficients, MFP, Z_eff, and HVL. The simulation outcomes were theoretically confirmed by using Phy-X software. The beta (electron) shielding characterization of the involved glasses was also investigated by determining the projectile range and stopping power using ESTAR software. Additionally, the fast neutron shielding characterization of the glasses was achieved by evaluating removal cross-section (Σ_R). The results reveal that the CdO has a small influence on the shielding performance of the boro-tellurite glasses against gamma, beta, and neutron radiations. The shielding performance of the boro-tellurite glasses was compared with that of common shielding materials in terms of MFP. It can be concluded that the boro-tellurite glasses regardless of the concentration of CdO content have promising shielding performance to be used for radiation applications.     

Zinc Nutrition and Inflammation in the Aging Retina

Zinc is an essential nutrient for human health. It plays key roles in maintaining protein structure and stability, serves as catalytic factor for many enzymes, and regulates diverse fundamental cellular processes. Zinc is important in affecting signal transduction and, in particular, in the development and integrity of the immune system, where it affects both innate and adaptive immune responses. The eye, especially the retina‐choroid complex, has an unusually high concentration of zinc compared to other tissues. The highest amount of zinc is concentrated in the retinal pigment epithelium (RPE) (RPE‐choroid, 292 ± 98.5 µg g^?1 dry tissue), followed by the retina (123 $\pm$62.2 µg g^?1 dry tissue). The interplay between zinc and inflammation has been explored in other parts of the body but, so far, has not been extensively researched in the eye. Several lines of evidence suggest that ocular zinc concentration decreases with age, especially in the context of age‐related disease. Thus, a hypothesis that retinal function could be modulated by zinc nutrition is proposed, and subsequently trialled clinically. In this review, the distribution and the potential role of zinc in the retina‐choroid complex is outlined, especially in relation to inflammation and immunity, and the clinical studies to date are summarized.     

The role of PbF2 on the gamma-ray photon,charged particles,and neutron shielding prowess of novel lead fluoro bismuth borate glasses

Journal of Materials Science: Materials in Electronics - The radiation shielding characterization of glasses is vital in establishing their role in nuclear protection applications. This study...     

Sodium Alginate—Natural Microencapsulation Material of Polymeric Microparticles

From the multitude of materials currently available on the market that can be used in the development of microparticles, sodium alginate has become one of the most studied natural anionic polymers that can be included in controlled-release pharmaceutical systems alongside other polymers due to its low cost, low toxicity, biocompatibility, biodegradability and gelatinous die-forming capacity in the presence of Ca²⁺ ions. In this review, we have shown that through coacervation, the particulate systems for the dispensing of drugs consisting of natural polymers are nontoxic, allowing the repeated administration of medicinal substances and the protection of better the medicinal substances from degradation, which can increase the capture capacity of the drug and extend its release from the pharmaceutical form.     

Entropy generation on MHD flow of a Casson fluid over a curved stretching surface with exponential space-dependent heat source and nonlinear thermal radiation

The present model concentrates on entropy generation on a steady incompressible flow of a Casson liquid past a permeable stretching curve surface through chemical reaction and magnetic field effects. The exponential space-dependent heat source cum heat and mass convective boundary conditions are accounted for. The resulting nonlinear boundary layer model is simplified by the transformation of similarity. Chebyshev spectral technique is involved for obtaining numerical results of the converted system of the mathematical models. Behavior of the determining thermo-physical parameters on the profiles of velocity, temperature, concentration, skin friction, heat, mass transfer rate, rate of entropy generation, and finally the Bejan number are presented. The major point of the present investigation show that the curvature term weakens the mass transfer profile as the fluid temperature reduces all over the diffusion regime. A decrease in heat generation strengthens the species molecular bond, which prevents free Casson particle diffusion. Furthermore, the mass transfer field diminishes in suction and injection flow medium.     

Kaduna

Compared with other ancient towns like Kano, Ile-Ife or Oyo, Kaduna is relatively new in the hierarchy of towns in Nigeria. It has, however, the distinction of having being established in the large northern protectorate solely for colonial administrative purposes. Kaduna was originally built on a grid pattern, with all roads intersecting and properly named. Facilities were well planned and most town planning rules obeyed. But the pressure of urbanization, the existence of many development agencies whose activities are not coordinated and political interference in planning functions are threatening to deface the beauty of the city. The government is constantly evolving strategies to maintain and enhance the beauty of the town through various land management procedures.