Policy challenges and food security in Alqadarif State, Sudan

Food security is under focused issue in Sudan as a whole and AlQadarif State is not apart from that. According to the integrated food security phases classification (IPC) report April (2015), about 60% of the population suffering from food insecurity in the State. This problem needs to be solved by clear and sound policies and strategies.  The main objective of this study is to investigate and evaluate the Food Security and Nutrition (FSN) policies and strategies in the State. To achieve this objective secondary data such as annual reports, policy documents were collected from all key line institutions and primary data were collected by the mean of a questionnaire the main results of this research are that: there were no clear food security and nutrition policy documents for the key line institutions in the State.  Also, there was a gap between the policymakers at the State level and the locality level. 42% of the policymakers at the locality level did not aware of the existence of the FSN body in the State. About 94% of the policymakers in the localities believed that the Chamber of Zakat plays a very important role in helping at FSN situations. About 92% of policymakers in the state said that finance is not sufficient. The majority of the localities policymakers, 94%, do not have any (FSN) database in their localities. Finally, the main recommendation of this study is to build a food security and nutrition policy/strategy putting the conservation of the natural resources in consideration

A hydrodynamic model for biomass gasification in a circulating fluidized bed riser

This study presents a three-dimensional Computational Fluid Dynamic (CFD) model and experimental measurements of the hydrodynamics in the riser section of a Circulating Fluidized Bed (CFB) biomass gasifier consisting of a binary mixture of polydisperse particles. The model is based on multi-fluid (Eulerian-Eulerian) approach with constitutive equations adopted from the Kinetic Theory of Granular Flow (KTGF). The study first presents an assessment of the various options of the constitutive and closure equations for a binary mixture followed by sensitivity analysis of the model to the solution time step, cell size, turbulence and the alternative formulations of the granular energy equation. Accordingly, a robust and reliable hydrodynamic model is recommended and validated using conventional pressure measurements and Positron Emission Particle Tracking (PEPT) technique. Furthermore, the model predictions and experiments revealed evidence of the particle re-circulation within the lower part of the riser, which is an important feature contributing to rapid mass and heat transfer in a CFB gasifier. The present hydrodynamic model can be further developed; by incorporating appropriate reactions and heat transfer equations, in order to fully predict the performance and products of a CFB biomass gasifier

Solving Robin problems in bounded doubly connected regions via an integral equation with the eneralized Neumann Kernel

This paper presents a boundary integral equation method for finding the solution of Robin problems in bounded multiply connected regions. The Robin problems are formulated as a Riemann-Hilbert problems which lead to systems of integral equations and the related differential equations are also constructed that give rise to unique solutions are shown. Numerical results on several test regions are presented to illustrate that the approximate solution when using this method for the Robin problems when the boundaries are sufficiently smooth are accurate

Feasibility Study for Water-Electricity Cogeneration Using Integrated System of Concentrated Solar Power and Biofuel as Renewable Energy

Although Concentrated Solar Power (CSP) is one of the promising renewable energy technologies, several technical and economic challenges should be addressed. One of the major issues associated with Concentrated Solar Power technologies is the reliability limitation of the plant in the stand-alone configuration. Therefore, Concentrated Solar Power systems can be integrated with either thermal energy storage (TES) or a fossil-fuelled power assist FFPA). However, initial and maintenance costs and emission production are the main challenges for the developing countries. Integrating biofuel/biogas with CSP increases the renewability while solar irradiation is in absent. The paper main objective is to perform a feasibility study of integrating a biofuel based gas turbine power units in a Concentrated Solar Power plant for electricity and water cogeneration. The study includes the thermodynamics analysis and assessment of three biofuels, namely, Jatropha oil, castor oil, and palm oil. In addition, a cost lifecycle, sensitivity, and Monte Carlo analyses were performed. The results showed that Castor oil had a better performance in terms of efficiency and carbon dioxide emissions with a maximum daily freshwater production of 181,000 m3/day. The proposed integration resulted in a levelized cost of water that is lower than the water tariff in the UAE by $1.39/m3 with a payback period of 5 years

Electricity and Water Cogeneration Utilizing Aluminium Furnaces Waste Heat Integrating Thermal Storage Organic Rankine Cycle

High energy-intensive industries, including steel, chemicals, cement, and aluminium, contribute to about 75% of the industrial emissions of carbon dioxide globally and expelling large amounts of unrecovered waste heat into the atmosphere. Yet, there has been a challenge of studies that are conducted on recovering waste heat in the aluminium industry, especially in cast-house facilities, due to technical difficulties such as energy fluctuations in mass flow rate and temperature. In this study, the waste heat to power system is designed to generate power and freshwater in a cast-house facility with 18 furnaces by evaluating three methods in which the temporal waste heat from holding furnaces can be damped and exploited. These methods are: (1) implementing a temporal air injection, (2) optimising furnaces operation time shift, and (3) integrating sensible thermal heat storage. Organic Rankine Cycle is used for the waste heat to power conversion. The appropriate thermal energy storage design and a thermodynamic model of an Organic Rankine Cycle are investigated using temporal flue gas data that are collected on site from three furnaces. Reverse Osmosis technology is applied to produce water using the generated electricity. Results show that sensible heat thermal energy storage is the most suitable technology for damping the fluctuations of waste heat. By utilising waste heat from 18 remelting furnaces, a net power output of 323 kW can be produced to operate a Reverse Osmosis plant supplying 2419 m3 of fresh water daily, saving up to 2000 metric tons of carbon dioxide emissions annually. This study gives a comprehensive approach to deal with temporal waste heat in aluminium furnaces for smooth cogeneration

Synthesis, Characterization and Application of Nano-adsorbent Materials in the Sorption of Pb(II), Ni(II), Co(II), Mn(II), Li(I) from Aqueous Solution

In this study, nano-adsorbent materials were synthesized from two different precursors by thermal activation technique. The first was the synthesizing of nano-zinc silicate from chemical reagents of zinc oxide and commercial silica gel. The second was the preparation of nano-pore size activated carbon from different biomass. The synthesized nano-adsorbent materials were characterized by different techniques; Surface Area, FTIR, XRD and SEM. The prepared nano-adsorbent materials were applied in the sorption and separation of some heavy metals from aqueous solution. These metals includes; Pb (II), Ni(II), Co(II), Mn(II) and Li(I). Some factors affecting on the sorption process (e.g. contact time and pH) were investigated. It was found that: the nano-zinc silicate (of ratio 1:1 thermally treated at 700 0C) and nano-pores activated carbon (prepared from saw dust impregnated with 70% H3PO4 overnight, then heated to 500 0C in presence of steam for 80 min.) were the best samples for sorption and separation of concerned heavy metals

Effect of Tire Lug Height, Forward Speed and Cast Iron Ballast on Tractor Performance

The study was conducted at El Rahad Agricultural Scheme (Block 8( Sudan, during the period Feb.-May 1996 where the soil is a heavy cracking clay. The objective of the study was to improve the performance of the tractor when worn tires were used. The performance of the tractor, wheel slippage, fuel consumption and field capacity of the tractor were measured. Three levels of tire lug height were used, namely, 35 mm (new tire), 20 mm (medium worm tire) and zero mm (fully worn tire). Four levels of cast iron ballast were used, namely, zero, 63, 126 and 252 kg were distributed between rear tires. Moreover, three levels of tractor forward speed (5.6, 6.9 and 10.6 km/hr) were employed. The results indicated that there was a significant improvement in tractor performance when using worn tires through the use of cast iron ballast on the rear wheels. It was found that tires with zero mm lug height and 252 kg cast iron ballast decreased tractor wheel slippage and fuel consumption by34% and 18%, respectively, and increased tractor field capacity by 16.2 % Moreover, when tires with 20 mm lug height and 252 kg cast iron ballast were used, the slippage and fuel consumption were decreased by 41.7 % and 18.2%, respectively, and tractor field capacity was increased by 14.5%. The tractor with tires lug height of 35 mm and 252 kg cast iron ballast, decreased slippage and fuel consumption by 22% and 11.5%, respectively, and increased tractor field capacity by 13.5%

Modeling In-Cylinder Water Injection in a 2-Stroke Internal Combustion Engine

AbstractIn this study, we apply Computational Fluid Dynamics (CFD) models in investigating the effect of injecting water into the combustion chamber of a 2-stroke Internal Combustion Engine (ICE). Using the commercial code, Star-CD, 3-D models for a port scavenging, in-cylinder fuel-injection; 2-Stroke engine is developed.The adapted engine's effective compression ratio (CR), crank Revolution per Minute (RPM) and fuel type are 8.5, 2000rpm and Heptane (C7H16) respectively. Two types of water mixing techniques are investigated: homogenous pre-mixing with the reactants, and direct injection around the walls of the combustion chamber. The engine's pressure, temperature, and pollutant mass fraction are estimated as a function of crank angle and injected water to fuel mass ratio, for both mixing techniques. The calculated indicated work (area under P-V diagrams) is used to estimate other engine performance indicated parameters. Results showed that although the homogenous mixing of water has an effect of reducing the combustion temperature and resulting NOx emissions, the pressure exerted on the piston is greatly diminished by this technique. However, when water vapor is injected around the chamber walls, the resulting reduction in temperature and NOx emissions has a minimum effect on the engine's P-V diagram.This is as a result of a water vapor blanket formed around the combustion zone, by the injected water vapor, which cools down the cylinder's wall with a minimum influence on the combustion process. Further analysisshowed that the water injection technique could increase the power/torque per engine size and hence, increase energy efficiency. Ultimately, the study presents the advantages of using water injection for enhancing fuel efficiency and reducing pollutant emission

A Mobile BS and Multi-Hop LEACH-C Extension for WSNs

It is critical for wireless sensor networks (WSNs) to have an uninterrupted power source. Increasing the lifetime of WSNs will require employing an energy preservation mechanism. In many WSN applications, sensors are used to detect events and collect environmental data, which are then delivered to a sink node or a base station node (BS) through a communication link. Sensors consume energy during wireless data communication, which is higher than the computational energy. This paper proposes an enhanced LEACH-C protocol that manages the network energy consumption and prolongs sensors lifetime. The proposed protocol is named Leach-C Multihop and Mobile (LEACH-CM). The proposed LEACH-CM protocol distributes the energy consumption between the network nodes and enables more data to be transmitted over a WSN. The proposed LEACH-CM protocol is simulated in the NS2 simulation, which is supported by the μ-AMPS project and is developed by MIT researchers. The simulation result shows that the proposed LEACH-CM protocol can decrease the energy consumption, and increase the amount of transmitted data compared to the LEACH-C protocol. Furthermore, the LEACH-CM protocol outperforms the LEACH-C protocol when comparing the dead time of the first node, which is a good indication of network stability