Optimization and life-cycle cost of health clinic PV system for a rural area in southern Iraq using HOMER software

This paper addresses the need for electricity of rural areas in southern Iraq and proposes a photovoltaic (PV) solar system to power a health clinic in that region. The total daily health clinic load is 31.6 kW h and detailed loads are listed. The National Renewable Energy Laboratory (NREL) optimization computer model for distributed power, “HOMER,” is used to estimate the system size and its life-cycle cost. The analysis shows that the optimal system’s initial cost, net present cost, and electricity cost is US$ 50,700, US$ 60,375, and US$ 0.238/kW h, respectively. These values for the PV system are compared with those of a generator alone used to supply the load. We found that the initial cost, net present cost of the generator system, and electricity cost are US$ 4500, US$ 352,303, and US$ 1.332/kW h, respectively. We conclude that using the PV system is justified on humanitarian, technical, and economic grounds.     

One-step purification of lactoperoxidase from bovine milk by affinity chromatography

Sulphanilamide was determined to be a new inhibitor of lactoperoxidase (LPO) with an IC₅₀ of 0.848.10⁻⁵ M. The K_i for sulphanilamide was determined to be 3.57.10⁻⁵ M and sulphanilamide showed competitive inhibition, which makes it a suitable ligand for constructing a Sepharose 4B-l-tyrosine affinity matrix. The affinity matrix was synthesised by coupling sulphanilamide as the ligand and l-tyrosine as the spacer arm to a cyanogen bromide (CNBr)-activated-Sepharose 4B matrix. Lactoperoxidase was purified 409-fold from the synthesized affinity matrix in a single step, with a yield of 62.3% and a specific activity of 40.9 EU/mg protein. The enzyme activity was measured using ABTS as a chromogenic substrate (pH 6.0). The degree of LPO purification was monitored by SDS–PAGE and its R_z (A₄₁₂/A₂₈₀) value. The R_z value for the purified LPO was found to be 0.7. Maximum binding was achieved and K_m and V_max values were determined.     

Distributed Simulation and Middleware for Networked UAS

As a result of the advances in solid state, electronics, sensor, wireless communication technologies, as well as evolutions in the material science and manufacturing technologies, unmanned aerial vehicles (UAVs) and unmanned aerial systems (UAS) have become more accessible by civilian entities, industry, as well as academia. There is a high level of market driven standardisation in the electronics and mechanical components used on UAVs. However, the implemented software of a UAS does not exhibit the same level of standardisation and compartmentalisation. This is a major bottleneck limiting software maintenance, and software reuse across multiple UAS programs. This paper addresses the software development processes adapted by the Australian Centre for Field Robotics (ACFR) in major UAS projects. The presented process model promotes software reuse without sacrificing the reliability and safety of the networked UAS with particular emphasis on the role of distributed simulation and middleware in the development and maintenance processes.     

Discrete dynamic convexized method for nonlinearly constrained nonlinear integer programming

This paper considers the nonlinearly constrained nonlinear integer programming problem over a bounded box. An auxiliary function is constructed based on a penalty function. By increasing the value of a parameter, minimization of the function by a discrete local search method can escape successfully from a previously converged discrete local minimizer. An algorithm is designed based on minimizing the auxiliary function with increasing values of the parameter. Numerical experiments show that the algorithm is robust and efficient.     

Production of in situ aluminum-titanium diboride master alloy formed by slag-metal reaction

Al-TiB₂ master alloys have received much attention in recent years owing to their potential as efficient grain refiners for aluminum foundry alloys. In this study, the process of production of master alloys was investigated to develop a low cost method, namely, slag-metal reaction. This method can be used to fabricate Al-TiB₂ master alloy in situ from the TiO₂-H₃BO₃-Na₃AlF₆ and Al system. Since the price of the raw materials is low and the technology is simple, the processing technique appears to reduce the cost of the master alloy. Because of exothermic reactions, not much energy is needed to melt materials. In this process, Titanium diboride particles were formed in situ through the reactions of TiO₂, H₃BO₃ and Na₃AlF₆. Results showed that when the aluminum melted, the condensed TiB₂ particles that formed in situ were spherical with an average diameter of 1 μm. Furthermore, these TiB₂ particles were distributed uniformly through the master alloy.     

Effect of some BED blends on the equivalence ratio, exhaust oxygen fraction and water and oil temperature of a diesel engine

Nowadays, natural-based oxygenated fuels, especially biodiesel and ethanol, have been considered as substitutes for fossil fuels. Because of relatively lower energy content of oxygenated fuels, it is necessary to blend them with fossil ones. In this research, authors conducted an investigation on some BED blends to determine and compare their effects on equivalence ratio, exhaust oxygen fraction and water and oil temperature in a diesel engine. For this purpose, 18 different blendes of ethanol and biodiesel with net diesel fuel were tested in a MT4-244 engine¹ considering two engine speeds in full load condition. In almost all samples the equivalence ratio decreased with increasing of biodiesel and ethanol percents. Exhaust oxygen fraction in all of samples increased with increasing of biodiesel and ethanol percents, whereas the engine water and oil temperatures slightly reduced.     

Preparation,FTIR spectroscopic characterization and isothermal stability of differently doped conductive fibers based on polyaniline and polyacrylonitrile

Conductive fibers based on polyaniline (PANI) and polyacrylonitrile (PAN) were obtained by stirring with magnetic bar. This research was conducted to investigate conducting fibers of polyaniline:polyacrylonitrile (PANI:PAN) composite with different weight ratios of aniline in PAN matrix. The fibers were prepared by stirring process. The best conductivity behavior of the fibers was obtained with 5 mL of aniline. The fibers obtained were characterized using Fourier-transform infrared spectra (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The variation of electrical conductivity with different type doping agents (HCl, H₂SO₄ and HClO₄) and the stability in terms of DC electrical conductivity retention was studied in an oxidative environment by isothermal characteristics.     

The effect of pH and calcium ion on rheological behaviour of β‐lactoglobulin‐basil seed gum mixed gels

Effect of pH (4.5–7.5) and Ca²⁺ (0.01–0.5 m ) on gelation of single and mixed systems of 10% β‐lactoglobulin (BLG) and 1% basil seed gum (BSG) was investigated. The gelling point of BLG and BSG gels was strongly pH‐dependent, and stiffer gels formed at higher pH. The BLG gels were formed upon heating to 90 °C and reinforced on cooling to 20 °C; however, the gelation of BSG occurred at temperatures below 70 °C. By increasing Ca²⁺ concentration, storage modulus of BLG and BSG gels were increased, although pH had a greater effect than Ca²⁺. In contrast, mixed systems showed two distinct types of behaviour: BLG gel formation and BSG network, suggesting that phase‐separated gels were formed. In addition, higher strength was obtained for BLG‐BSG mixture at higher Ca²⁺ concentration.     

Performance and thermo-economic assessments of geothermal district heating system: A case study in Afyon,Turkey

In this study energy, exergy and exergoeconomic analysis of the Afyon geothermal district heating system (AGDHS) in Afyon, Turkey is performed through thermodynamic performances and thermo-economic assessments. In the analysis, actual system data are used to assess the district heating system performance, energy and exergy efficiencies, exergy losses and loss cost rates. Energy and exergy losses throughout the AGDHS are quantified and illustrated in the flow diagram. The energy and exergy efficiencies of the overall system are found to be 37.59% and 47.54%, respectively. The largest exergy loss occurs in the heat exchangers with 14.59% and then in the reinjection wells with 14.09%. Besides, thermo-economic evaluations of the AGDHS are given in table. Energy and exergy loss rates for the AGDHS are estimated to be 5.36 kW/$ and 0.2  kW/$, respectively.