Avanti Publishers
Not a member yet
711 research outputs found
Sort by
Efficient Cooperative Particle Swarm Optimization for TSK-Type Neural Fuzzy Systems and Its Classification Applications
Get PDFThis study proposes a cooperative particle swarm optimization (CPSO) to optimize the parameters of the TSK-type neural fuzzy system (TNFS) for classification applications. The proposed CPSO uses cooperative behavior among multiple subswarms to decompose the neural fuzzy systems into rule-based subswarms, and each particle within each subswarm evolves by a specific particle swarm optimization (PSO) separately. Therefore, the CPSO can accelerate the search and increase global search capacity. Finally, the TNFS with CPSO (TNFS-CPSO) is adopted in several classification applications. Experimental results demonstrate that the proposed TNFS-CPSO method has a higher accuracy rate and a faster convergence rate than the other methods
Potential of Cattle Manure Ash to Improve Soil Fertility and Groundnut (Arachis hypogea L.) Growth in the Adamawa Region (Cameroon)
Get PDFGroundnut (Arachis hypogea L.) production is a key farming activity in Cameroon, since it substantially contributes to human nutrition, economic wealth of farmers and soil fertility. Most cropping systems in sub Saharan Africa are limited by low soil fertility and subjected to the slash-and-burn agriculture. A study was conducted to investigate the potential of cattle manure ash, derived from cooking activities as soil conditioner in order to improve soil fertility and groundnut performances in two sites in the Adamawa region (Cameroon). The results showed that cattle manure ash slightly increased soil pH, soil moisture, SOM, Corg and C/N ratio in amended plots. Cattle manure ash improved nodule weight and increased arbuscular mycorrhizal fungi colonization in one site, that was translated to better N assimilation, and dry weight of both groundnut varieties used in the study. Future studies are needed to evaluate the full potential of cattle manure ash application, alone and/or associated with others organic wastes for sustainable agriculture in the tropics
Nuclear Desalination: An Alternative Solution to the Water Shortage
Get PDFGlobal water shortage is one of the rising problems that, nowadays and worldwide, Countries and governments have to face. People from many countries have to deal with scarcity of water supply and aquifer pollution that could jeopardize their health and agriculture. Desalination process could be one of the most promising method to hinder such phenomenon. During this work we analyzed different desalination processes and the state of art of the technology. In this paper we carried on a deep evaluation of the state of art of desalination processes. Obviously all these methods need a driving force in terms of energy. With the aim of a more environmental friendly scenario, nuclear energy has been chosen as energy source for different desalination processes, implementing the so called nuclear desalination. Moreover a nuclear scenario analysis has been studied for the UAE (United Arab Emirates), one of the countries that have to deal with water shortage and that presents today an ambitious nuclear program
CFD Benchmark Tests for Indoor Environmental Problems: Part 4 Air-conditioning Airflows, Residential Kitchen Airflows and Fire-Induced Flow
Get PDFComputational Fluid Dynamics (CFD) has become practical design tool for indoor environment recent years and the application cases have been increasing. Though the improvement of the prediction accuracy of CFD is needed in connection with the upgrade of design quality in indoor environment and Heating, Ventilation and air-conditioning (HVAC) system, the prediction accuracy of CFD simulation depends on the understanding for the fundamentals of fluid dynamics and the setting of appropriate boundary and numerical conditions as well. Additionally, deeper understanding to a specific problem regarding indoor environment is also required. The series of this study aimed to provide with the practical information such as prediction accuracy and problematic areas related to CFD applications in air conditioning and ventilation, then performed benchmark tests and reported the results. Especially in this Part 4, benchmark test results for Air-conditioning airflows, Residential kitchen airflows and Fire-induced flow were introduced and discussed
Petroleum Geology: Science and Practice in the 21st Century. New Ideas and Paradigms
Get PDFOil-and-gas-saturated stratum is an integral interrelated system of rocks (minerals) and fluids (oil, gas, and water). Being a «living» fluid-rock system, it is subject to the laws of auto regulation. It is necessary that research and practical efforts be focused on study and control of the oilfield «life»
Influence of Two Steps Sintering Parameters on Tribological Behaviour of Hybrid Hydroxyapatite-Based Biocomposites
Get PDFThe nanostructured biocomposites with hydroxyapatite (HAP) matrix reinforced by titanium (Ti), processed by two steps sintering (TSS) route in argon atmosphere, provide excellent wear behaviour when they are elaborated in specific sintering parameters. The wear tests, developed in steel ball-on-disc dry conditions, show low wear rates about 2x10-4 [mm3/Nm] when the biocomposites are processed at 750...8000oC for 450...600 min. in comparison with high wear rates 7x10-4 [mm3/Nm] in 700...7500oC for 300 min. as TSS parameters. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis outline the structural features that explain this wear behaviour
Synthesis and Characterization of Novel Nano-,Micro- and Macroporous Lignin Sorbents for Purification of Biological Fluids
Get PDFNovel nano-, micro- and macroporous ion-exchangers based on hydrolytic lignin of cotton husk have been synthesized by two-step process including o-alkylation of biopolymer with diglycidyl ether of dioxydiphenylpropane and subsequent amination of formed glycidyl derivative. The optimal conditions of synthesis, composition, structure and physical, chemical properties of ion-exchangers were investigated by FTIR, SEM, porosimetry and potentiometric titration method. Textural characteristics of lignin and sorbents were also studied. It has been established that alkaline activated lignin shows an increase of SBET from 17.7 to 20.9 m2/g while modification leads to decrease of SBET more than double (from 14.5 to 9.2-5.2 m2/g) that of an untreared sample. Synthesized ion-exchangers are characterized by approximately identical porous structure and mainly contained a pore size of 10-14 nm. The results show the efficiency of lignin based sorbents for the removal of water and lipid soluble toxic metabolites from blood serum of diabetic retinopathy patients. Considerable detoxication effects of sorbents have potential for prevention and treatment of diabetes
Swelling Kinetics and Diffusion Coefficients of Polyacrylamide Hydrogels Via Different Drying Methods
Get PDFIn the present study, polyacrylamide (PAAm) hydrogels were formed by copolymerization of acrylamide (AAm) and N,N' methylenebisacrylamide. The reaction is a vinyl addition polymerization initiated by a free radical generating system. N,N' methylenebisacrylamide, N,N,N',N'-tetramethylethylenediamine (TEMED) and ammonium persulfate (APS) were used as the cross linking agent, catalyzer and initiator, respectively. Hydrogels were dried with two drying methods: the former is the poor solvent method, the latter is the freze dryer method. The effects of the drying methods on swelling behavior were investigated as a function of time. A variety of hydrogel swelling kinetic modelling techniques were applied on the dynamic swelling rates of PAAm hydrogels. For all the hydrogels, the diffusion coefficient of kinetic parameters such as the diffusion mechanism (Fickian or non-Fickian mechanism), initial and equilibrium swelling ratios, the penetration rate of the solvent and diffusion coefficient were determined
Assessment on the Stability and Speciation of Phosphorus in River Sediments
Get PDFSediments are heterogeneous mixtures of assorted soil separates and organic matter that serve as repositories of many pollutants. This study investigated phosphorus (P) stability in river sediments as controlled by P speciation and environmental conditions, such as temperature (T), dissolved oxygen (DO), redox conditions (Eh), and pH. It attempted to evaluate the experimental conditions under which P could potentially be tied-up in river sediments. Sediment cores samples were collected from James River, in Virginia, U.S.A. near a former dairy farm and analyzed for T, pH, Eh, carbon (C) and pertinent metal ions. Results indicated that high P concentration correlated well with Fe and had non-uniform correlations with clay, Al and Ca, which changed with depth of cores. At low pH, P concentration was higher in anaerobic than aerobic sediments and aluminum (Al) precipitation was highest at low pH, which indicated Al phosphate stability in reduced (anaerobic) conditions. Above pH 7, in aerobic environments, the Minteqa2 speciation model predicted a high stability for Al-OH species. The minerals variscite, vivianite, strengite hydroxyapatite, and two forms of magnesium hydroxide species were predicted to exist in the pH ranges used in this study. Elemental P distribution assessment using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX) inferred that P could be bound either to C and Al, Fe or Mn depending on their relative abundances
Approximation Properties of Bivariate Extension of q-Stancu-Kantorovich Operators
Get PDFIn this paper we introduce a new q-Stancu-Kantorovich operators and we study some of their approximation properties. Furthermore, a Voronovskaja type theorem is also proven