The aim of the current study was to investigate biogas production from the slaughterhouse waste codigested with animal wastes. Slaughterhouses generate organic wastes that are environmentally hazardous due to high contents of biological contaminants. The use of anaerobic digestion of the slaughterhouse waste can achieve twin objectives of waste treatment and energy production as biogas. The process is however, limited by low biogas potential of slaughterhouse waste. The study evaluated the effect of co-digesting the slaughterhouse, chicken and pig wastes on biogas potential. The co-digestion test with combination ratio of 1:1, slaughterhouse waste and chicken waste produced the highest value of biogas potential of 636 L/kg-VS, which was almost double that from pure slaughterhouse waste. In addition, the substrate biodegradability, the biogas productivity and the yield were most improved at 1:1 co-digestion. The digestate from the process had high nutrient contents and a maximum of; 0.8, 2.6 and 2.7% of dry matter for total nitrogen, phosphate and Potassium respectively. The kinetic analysis of the co-digestion process using modified Gompertz equation indicated a correlation between the waste biodegradability and biogas yield. The enhancement of the C/N ratio in the slaughterhouse waste by co-digestion with these wastes could be responsible for the improvement of the biogas production and yield. Future studies should focus on how the nutrient rich digestate can be appropriately applied as bio-fertilizer and on how co-digestion affects the pathogens in slaughterhouse wastes.
This study aims at the physico-chemical characterization of Alchornea cordifolia oil isolated from the seed of this plant, to identify the bioavailability of epoxidized triglycerides. The ripe fruits of Alchornea cordifolia were harvested in southern Congo-Brazzaville in the localities of Goma-tsétsé and Dolisie. The oil is extracted from the seeds by three different methods: cold method (Folch), Soxhlet method, and water method. The fat contents are of the order of 18 to 28% by the water method, 30 to 37% by the Folch method and 45 to 56% by the Soxhlet method. All these methods exhibit similar fatty acid profiles. They are characterized by the presence of palmitic acids (C16: 0) 8 to 15%, stearic (C18: 0) 1 to 2%, oleic (C18: 1) 8 to 12%, linoleic (C18: 2) 8 to 12%, epoxidized fatty acid 48 to 63%, selacholeic (C24: 1) 2 to 3%. The epoxidized fatty acid contents are of the order of 50 to 63% by the water method, 50 to 61% by the Folch method and 48 to 58% by the Soxhlet method. The oil extracted with water has slightly higher epoxidized fatty acid contents than that extracted by other methods. The fatty acid composition of Alchornea cordifolia seed oil from Congo is characterized by high levels of epoxidized fatty acids in the order of 48-63%. This multi-functional acid has considerable commercial potential.
To determine the radon potential level and estimate the related exposure of the public, combined gamma dose rate and radon measurements were performed in 15 dwellings in Yopougon, the largest and inhabited commune of Côte d’Ivoire. Indoor gamma dose rates were measured using a gamma survey meter. Radon concentration measurements were performed using LR-115 films detectors (SSNTDs) for three months. The mean indoor gamma dose rate in air was 20 nSv/h whereas the mean radon concentration indoor was found to be 93.04 Bq/m 3 . The relationship between indoor radon measurements and gamma dose rates was also investigated. A very weak correlation between the two variables was observed.
This study aims to interpret the non-linear steady-state heat conduction for temperature-dependent thermal conductivity ($k$ ($T$)) using Element-Free Galerkin (EFG) method. In this present study, a one-dimensional heat conduction problem with uniform heat generation was explicated. Moving Least Squares (MLS) approximants were applied to estimate the unknown function of temperature $T$ ($x$) with $T^h$ ($x$) using linear basis and weight functions. The variational method has been used to develop discrete equations. Essential boundary conditions are enforced by using the Penalty method. The results have been obtained for the one-dimensional model using essential MATLAB codes. The results obtained by the EFG method are compared with the analytical and finite-element method results. The results are also studied by increasing the number of nodes to study the convergence which indicated that EFG has good convergence behavior. The results have also been obtained for different values of the scaling parameter ($α_s$) and any values of αs between 1.8 and 2.0 were found suitable for providing better results in the EFG method.
The seriousness of the phenomenon of negative skin friction on piles penetrating Basrah soil in Iraq is investigated via the finite element method. The most common (0.285×0.285 m) precast driven and (0.8 m diameter) bored piles, are analyzed under the structural loads and down drag forces due to recent fill. A two-dimensional program adopting nonlinear constitutive relations for soil layers is utilized. The results revealed a great decrease in negative skin stress and pile length on which the phenomenon is to act upon, due to the application of structural loads. Reductions in drag forces as much as (86%) for driven piles and (96%) for bored piles are recorded in some sites. It is also concluded that, overlooking the negative skin friction does not result in failure and that more economical pile capacities could be adopted.
The analysis of residual stresses generated during the injection molding process is crucial for the part quality assessment. The present study evaluates the generation of residual stress considering different variables that affect them. For that purpose, diverse part geometries were evaluated with different polymers (polycarbonate, ABS and polypropylene) and some Design of Experiments (DOE) were implemented in a simulation software of injection molding process (Moldex 3D). The results show higher residual stresses in thick wall parts due to unbalanced cooling through-thickness. For thin-wall parts, residual stresses were lower because of better cooling through its thickness. The polycarbonate was the more sensitive polymer to residual stresses upon its processing conditions, being the mold temperature and the packing stage the most critical variables to increase or reduce residual stresses.
The aim of this study was to determine optimum enzyme concentration and hydrolysis time needed to hydrolyze black soldier fly prepupae into a protein hydrolysate.The prepupae were homogenized with aquadest and papain enzyme (0-9% on a weight basis) at pH 7 for 24-72 h at 55°C.At optimum conditions (enzyme concentration of 6% on a weight basis and hydrolysis time of 24 h), the yield of protein hydrolysate was 31% on a dry weight basis.The protein content increased from 39.7 to 61% (dry weight basis) whereas the lipid content in the protein hydrolysate decreased from 30.3 to 0.5% (dry weight basis).Hydrolysis of the prepupae with a papain enzyme increased the amino acid content from 15.4 to 47.1% on a weight basis.The black soldier fly prepupae contains 15 detectable amino acids primarily consists of glutamic acid (10.7%), alanine (10.7%), leucine (10%) and valine (9%).After hydrolysis with a papain enzyme, the composition of the amino acid changed and primarily consists of glutamic acid (17.3%), tyrosine (9.4%), leucine (9.4%) and alanine (8.9%).The protein hydrolysate may find application as a supplement for feed and food for a better absorption of nutrients in animal intestine.
The aim of this study is to discuss the reasons behind introducing Building Information Modeling into the Architecture domain, an in-depth investigation of its application effects on the design process in architecture pedagogy in Jordanian Architecture schools is carried out. Technology is the new spine of modern societies; architecture discipline is an interconnected sector in which computer programs have boosted, through multi-functioning capabilities. BIM (Building Information Modeling) is the new movement toward linking the Architectural Engineering and Construction (AEC) industry. Its effects on changing the conventional design process, presentation, and communication have altered the architecture profession in addition to education. Many Architecture schools adopted BIM in their curriculum, and many did not, therefore, the evaluation standards for student’s work creativity have changed drastically. The research methodology consists of analyzing the fifth-year architecture student's work (at the Architecture Department/University of Jordan) in reference to their followed design process. The outcomes varied according to the followed design process (manual/Cad/BIM) revealing a pattern in the results. The students’ work was evaluated by several accredited architects in addition to architecture educators from the university itself. The findings were also a huge indicator of the students’ preference for using BIM in their designs. However, the students who adopted the manual method managed to achieve better.
Utilization of waste materials in geotechnical applications reduces the environmental problems of factories wastes.Silica fume is a by-product of the extraction of silicon or ferrosilicon manufacturing.Using silica fume as an additive to the soil can significantly increase the strength and decrease the permeability of the mixture.In this study silica fume is used to improve the mechanical properties of cohesionless soil, with special attention when used as backfill material for reinforced earth retaining walls.Biaxial geogrid prototype was used as reinforcement sheets in prepared bed of sand-silica fume mixture.The effect of adding silica fume was evaluated based on the results of Pull-out tests under various overburden pressures.From this study it was concluded that, adding silica fume to the sand had reduced the pull-out displacement of the geogrid by about 30% to 91% depending on the applied overburden pressure.That interlocking between the sand and silica fume particles is the main cause of densifying the sand by minimizing the lateral movement of the particles.Reduction in geogrid elongation reflects the increase in shear resistance interaction of the geogrid-backfill, and consequently the increase in the stability of the reinforced earth retaining walls under static and earthquake actions.
The aim of this study was to investigate the potential bioconversion of rice straw and tofu residue using larvae of Hermetia illucens assisted by microbes to produce protein-rich biomass and organic fertilizer. Larvae of Hermetia illucens were cultivated in rearing containers (25×20 cm) with three different types of substrate containing rice straw, tofu residue and solution containing consortium of microbes. The rice straw used in this study contains 22.1% hemicellulose, 30.3% cellulose, 8.0% lignin and 6.8% protein (weight basis) while the tofu residue contains 20.9% protein (weight basis). The substrate rate was set at 150 mg/larva/day and the ratio of rice straw: tofu residue was varied from 1:0 to 1:3. The highest prepupal biomass productivity of 179.8 g/m2/day on a dry weight basis with an assimilation efficiency of 21.5% and efficiency of conversion of digested substrate of 34.9% was obtained when the larvae were fed with rice straw and tofu residue (1:3) that had been pre-treated with a solution containing 107 cell/mL microbes. At this condition, the prepupal biomass has protein and fat content of 31.8 and 15.5% (weight basis), respectively. The cultivation residue contains a relative high amount of organic carbon (43-46%) with pH 7.16-7.82 and carbon to nitrogen ratio of 22-47 and a total macronutrient of 2.33-3.21% and functional microbes of 2.0-4.5×108 CFU/mL. The results highlight the potential of black soldier fly larvae as a bioconversion agent to convert agricultural waste into protein-rich biomass and organic fertilizer.
This study presents a complete model for RobotinoMD an omnidirectional mobile robot. This model includes the kinematics and dynamics. It is used for the simulation and design of an adaptive nonlinear control system. The hierarchical control system that is proposed has three levels. The level-one which is the inner loop is used to control the DC motors that drive the robot wheels. A control design method combining an adaptive feedback linearization technique and the Backstepping approach is used to find the controller equation. The adaptation module that is included in the control system maintains the performance of the system in the presence of uncertainties on the inertia, weight and other parameters in the robot dynamics. The level-one controller receives its reference signal from the level-two controller which converts the linear and rotational speeds into desired speeds. This level-two controller receives its reference signal from the level-three controller which is the outer loop controller. The level-three controller equation is found so that the robot can follow a desired path described in a Cartesian space. The proposed control system is evaluated in simulation in the MATLAB-SIMULINK environment. It is compared to a PID controller. Simulation results show that the nonlinear adaptive controller has better performances.
The recent study deals with the numerical analysis of an unsteady Maxwell nanofluid flow passing through a porous stretch surface with slip boundary condition with chemical reaction effect using Buongiorno's mathematical model. The water based fluid and the gold nanoparticles (Au) are preferred for this study. The similarity transformations are applied to renovate the governing model equations into a set of ordinary non-linear differential equations. The solutions of the coupled non-linear dimensionless equations are numerically decoded using the Nachtsheim-Swigert shooting method together with the Runge-Kutta iterative technique for various values of the flow control parameters. In addition, the built-in function bvp4c of MATLAB is used to enhance the consistency of numerical results. The numerical results are graphically demonstrated and narrated from the physical point of view for the non-dimensional velocity, temperature and concentration profiles, as well as the local coefficient of skin friction, Nusselt number and Sherwood number for different parameters of materials, such as the volume fraction parameter, Deborah number, unsteadiness, slip, stretching, suction and chemical reaction parameters. It is witnessed that the heat transfer rate is widely controlled by the Deborah number for Au-water nanofluid. The outcomes of this analysis clearly indicate the considerable influence of the suction imposed in the model.
Port Sudan city is a capital of the Red Sea State in the republic of Sudan in south-eastern Africa. The city has high consumption of power for street lighting. The lighting is needed for 12 h/day. This consumes about 11.5 Mw day. The aim of this paper is study the proposed system to reduce the streetlight power consumption use in Port Sudan City and to explore the renewable energy to work alternative energy sources. The present paper studies the proposed system called (all-in-one) street lighting system consisting of PV panel, lithium ion battery and light sensor with LED lamp, all connected and constructed in single unit. The proposed system is to be used in Port Sudan city to decrease the electricity consumption, especially in summer. The problem has been treated theoretically. The proposed system has been compared with two types of plant the first plant used 250W lamp Ac and the second plant used 100W LED lamp. The results show that the proposed system has low cost, about 80 USD and much better economically. The proposed system can solve the power loss in Port Sudan city, saving 11.5 Mw day for this city and more than 428,000 SUP/day. The results show that the proposed system could be utilized to reduce lighting consumption, save energy and developments on environment. We therefore recommended to uses the proposed system in many countries not only in Port Sudan City.
Aim of this study is to propose a control strategy based on Simulated Annealing (SA) as a metaheuristic algorithm and Fuzzy Logic Controller (FLC) for semi-active nonlinear control of structures equipped with Magnetorheological (MR) dampers to prevent damage from severe dynamic loads such as earthquakes. MR dampers as promising semi-active control mechanisms are focus of attention for reducing seismic response of structures in the world of structural engineering. A fuzzy controller is applied to establish interactive relationships between structural responses and input voltages to the MR damper. A modified simulated annealing algorithm is employed as an evolutionary algorithm to design the fuzzy controller, which is herein described as a Modified Simulated Annealing-Fuzzy Logic Controller (MSA-FLC). Results of numerical simulations demonstrated the efficiency of the proposed smart strategy compared to similar methodologies recommended by other researchers.
The adsorption of cobalt onto biomaterial of microalga Oscillatoria sp was investigated via batch experiment. Marine alga Oscillatoria sp was isolated from Teluk Jakarta Indonesia. The characterization of the functional group with FTIR spectrum showed microalgae have a functional group of $O-H, \>C = O, \>COO, \>C-O-C, \>N-H, \>C-S, \>C-H$ and $PO_4^{3-}$. Adsorption of cobalt ion was investigated as a function of time, pH, initial cobalt concentration, the dosage of biosorbent, salinity dan shaking. Equilibrium and kinetic adsorption were obtained from the batch experiment. The cobalt adsorption followed the Langmuir and Freundlich, isotherm models. The Freundlich constant (Kf) and n were $0.1186 \>(mg/g) (L.mol)^{\frac 1 n}$ and $8.43\>mg/L$, respectively. The maximum adsorption capacity was 4.71 mg/g at pH 8. Oscillatoria sp could adsorb cobalt even at a lower concentration, indicating a good affinity for metal. Kinetic studies showed that the adsorption of cobalt ion followed a pseudo-first-order with $k_1 \>= \>1.2×10^{-3} min^{-1}$.
The aim of this study was to investigate the effectiveness of heated black cotton soil as a precursor in lime-activated stabilization of black cotton soil in-place for use in flood-prone areas. Most methods used to improve expansive soils include the use of lime or lime-activated materials, cut to spoil followed by replacement and thermal treatment. Most lime treatment methods yield a material that cannot withstand high moisture levels and long flooding periods. Cut to spoil results in high costs and negative environmental consequences. Lime activated Ground Granulated Blast Furnace Slag (GGBS) has been found to be effective in flood conditions, but it has to be locally available. In this study, Unconfined Compressive Strength (UCS) tests were done on 50 mm diameter by 100 mm long stabilized soil specimens using various mixes of heated black cotton soil and lime which established an optimal mix of 14% heated black cotton soil at 400°C and 6% lime as the binders with 80% neat black cotton soil. Investigations of properties of this mix subjected to moist curing periods of 7, 14, 28, and 90 days followed by soaking them in water for 4 and 10 days after each curing period to simulate flash and severe flooding respectively were done. The durability reduction indices for each flooding scenario were computed. The mix yielded a strong durable product able to withstand flooding conditions. The heated black cotton soil at 400°C is, therefore, an effective low calcium aluminosilicate precursor with lime as the alkali activator.
This paper presents a theoretical study of the external magnetic field and the air mass effects on the carrier density, the transient open circuit voltage decay and the effective minority carrier’s lifetime in a polycrystalline silicon solar cell. From a theoretical approach based on the columnar model of the grains and the quasi-neutral base, the three-dimensional diffusion equation is established and the boundaries conditions are defined in order to use Green’s functions to solve this equation. New analytical expressions of carrier’s density and transient voltage are also found. The magnetic field and the air mass impacts on transient electrons density and transient open circuit voltage are then analyzed. The effective minority carrier lifetime is extracted from the curve versus time of transient open circuit voltage decay for different values of magnetic field and air mass.
The aim of this study is to improve the proprieties of the mixtures of rice straw and clay. Thus, we conduct this study related to the mixtures of rice straw, clay and cement for their use as building material. The clay formations represent abundant economical materials resources available in tropical and equatorial Africa. Rice straw is rich in cellulose. Consequently, few animals are able to use it as food. We have determined by experiments the mechanical and thermal properties of samples. The Interesting results obtained show that the integration of mixtures of rice straw, clay and cement in building materials are great opportunities to reduce the cost of social housing. It also improves the thermal comfort.
Permanent magnet synchronous motor as an actuator for ropeless elevator has several challenges that have to reduce to make the system stable and secure. Detent force as one of a problem for having stabilization system is going to investigate on how its performance under fuzzy logic controller with a nonlinear test such as variations on load and distance to get a policy that can be used for industrial field or other human activities. Preliminary research is presented in this study by making a simulation of control with a fuzzy logic application by Mamdani design and this also aims to compare the previous PI simulation paper. In this fuzzy controller, simulation made with parameters which can cause the existence of detent force such as load, speed, distance, current and power to analyze how the performance under variation situation. With this simulation yield that fuzzy can relatively minimize detent force without considering the impact of saturation or hysteresis on the controller. The simulation is done on 2018 in electrical department of Universitas Indonesia by using the MATLAB R2010a toolbox.
