Towards overhead mitigation in state-free geographic forwarding protocols for wireless sensor networks

Wireless Networks - Routing has been the most consumptive of all processes engaged in the Wireless Sensor Network communications, thus improving this consumptive process by minimizing the number of...     

Thermal behavior of concentrated oil-in-water emulsions based on soybean oil and palm kernel olein blends

Droplet size distribution and thermal behavior of concentrated oil-in-water emulsions based on soybean oil (SBO)/palm kernel olein (PKO) blends were investigated. The emulsions were prepared using 70% (wt./wt.) oil blends of SBO/PKO as dispersed phases and stabilized by egg yolk. An increase in PKO level (0–40% wt./wt.) in the oil dispersed phase volume fraction caused significant increases (p < 0.05) in volume-weighted mean diameter (d_4,3). The DSC data suggested that crystallization of the emulsions was induced by a ‘template effect’ of yolk constituents via a surface heterogeneous nucleation. Emulsions with 0–20% (wt./wt.) PKO levels in the dispersed phase demonstrated a good cool–heat stability even after three successive thermal cycles (from 50 °C to ?70 °C at 10 min/°C). After the first thermal cycle, emulsions with 30% and 40% PKO levels in the oil dispersed phase were destabilized due to strong coalescence and crystallized via volume-surface heterogeneous nucleation. The unstable emulsions were attributable to high level of saturated triacylglycerols from PKO, with high droplet size characteristic, causing them to be more prone to partial coalescence.     

Effect of ethanol as gasoline additive on vehicle fuel delivery system corrosion

In this research, the effect of ethanol as gasoline additive has been investigated into metal corrosion of a fuel delivery system. Corrosion tests have been performed in gasoline with different percentages of ethanol, using weight loss (immersion test) and electrochemical impedance stereoscopy (EIS) procedures. Surface of test specimens were checked by scanning electron microscopy (SEM) after 144 days of immersion in test solution. Also corroded components were analyzed using energy‐dispersive X‐ray analysis (EDAX) method. Test results, investigations, and analyses, altogether show more corrosion with the increase in ethanol percentage and water content in gasoline. Test results show that among different materials in fuel delivery system, aluminum alloys and hard soldering alloys have less corrosion than the others. Also chloride and sulfide were recognized as the main compound of corrosion products; therefore, the control of these two elements in fuel delivery system is a must in case of using ethanol as fuel additive in near future.     

Genotoxicological Assessment of Nebuloside-A a Triterpenoid Saponin Compound on Whole Blood DNA

We investigated the genotoxic effect of nebuloside-A on whole blood DNA by using alkaline Single Cell Gel Electrophoresis Comet assay. Saponins are a widespread class of bioactive compounds produced by many plant species. Nebuloside A was isolated from baby’s-breath (Gypsophila arrostii) by high performance liquid chromatography method. Mass spectra obtained by electrospray ionization-time of flight-mass spectrometry in a negative ion mode to reduce the protonation. Complete nuclear magnetic resonance spectroscopy assignments of nebuloside A was achieved by using 2D-nuclear magnetic resonance spectroscopy techniques, such as double-quantum filtered correlation spectroscopy, heteronuclear single quanthum correlation, heteronuclear multiple-bond correlation, and total correlation spectroscopy. DNA damage was measured in total arbitrary units by visual scoring of comets in different concentrations of nebuloside A and H₂O₂ treatments. We found that significant dose dependent relationship between nebuloside A and its genotoxic effect.     

Assignment of 1H NMR spectrum and investigation of oxidative degradation of poly(ethylenimine) using 1H and 13C 1‐D and 2‐D NMR

The ¹H NMR spectrum of poly(ethylenimine) (PEI) has been assigned using two‐dimensional NMR correlation with the previously established assignment of the ¹³C spectrum. The oxidative thermal and UV degradation of PEI has been studied using mass loss measurements, and NMR and Fourier transform infrared spectroscopy. Analysis of the spectra of the degradation products shows that the degradation process may readily be monitored, particularly by ¹³C NMR. The major products are formamide and other amide groups which may be understood in terms of chain scission and dehydration reactions of hydroperoxides. Copyright © 2006 Society of Chemical Industry     

Lack of correlation between microscopic lesion scores and gross lesion scores in commercially grown broilers examined for small intestinal Eimeria spp. coccidiosis

Comparisons were made between microscopic lesion scores (MLSs) and gross lesion scores (GLSs) in sections from small intestine of broilers during three routine coccidiosis screenings. The duodenal and jejunal GLS were determined and recorded by different evaluators. During each screening, 2-cm sections of duodenum and jejunum were collected, and sections of intestine were then scored using a microscopic lesion scoring system. No correlation between MLS and GLS was observed in duodenum in two out of three coccidiosis screenings, and no correlation was observed between MLS and GLS in jejunum in three out of three screenings. Our findings demonstrate that, if used alone in coccidiosis screening, GLSs can underestimate infections and may not provide a true representation of the magnitude of Eimeria maxima infection within broiler flocks.     

Modelling of synthesis of waste cooking oil methyl esters by artificial neural network and response surface methodology

This present study was carried out to investigate the application of artificial neural network (ANN) and response surface methodology (RSM) as modelling tools for predicting the waste cooking oil methyl esters (WCOME) yield obtained from alkali-catalysed methanolysis of waste cooking oil (WCO). The impact of process parameters involved was studied by a central composite rotatable design. A comparison of the two developed models for the methanolysis process was carried out based on pertinent statistical parameters. The calculated values of coefficient of determination (R²) of 0.9950 and the average absolute deviation (AAD) of 0.4930 for the ANN model compared with R² of 0.9843 and AAD of 0.9376 for the RSM model demonstrated that the ANN model was more accurate than the RSM model. The actual maximum WCOME yield of 94?wt% was obtained at a reaction temperature of 55°C, a catalyst amount of 1?w/v, a reaction time of 70 min and a methanol-to-oil ratio of 6:1.

Abbreviations/Nomenclature CV: coefficient of variance; FFA: free-fatty acid; R: correlation coefficient; R²: coefficient of determination     

Abstraction and context in requirements engineering: Toward a synthesis

Most requirements engineering (RE) research and practice embodies a philosophy that we will call abstractionism, which involves the building of simplified models of domains of discourse and proposed systems. Abstractionists make much use of formal models, such as goal dependency networks. An alternative design philosophy is contextualism, according to which the particularities of the context of use of a system must be understood in detail before the requirements can be derived. Contextualists use qualitative methods to uncover and help interpret these particularities. In this paper, we analyze what it would mean to combine the best features of abstractionism and contextualism, and we ground our discussion in an illustration of abstractionist and contextualist thinking about RE through goal refinement (GR). In the context of the domain of meeting scheduling, we contrast a wholly abstractionist approach to GR with one that incorporates data gathered using two ethnographic methods. In doing so, we consider each step of the abstractionist approach, illustrating where ethnographic data obtained in our work environment affects the model produced. As we proceed, we summarize the general lessons learned. We then discuss how other abstractionist and contextualist methods could be integrated.     

Analysis of the radiation resistance and gain of a full-wave dipole

The full-wave-dipole antenna is very seldom used in communication systems, and yet this type of antenna offers a very high gain. This is due to the high input impedance for the center-tap feeding-point antenna. The analysis of short-length and half-wavelength dipole antennas has been reported, in great detail previously, in texts. However, an analysis of the full-wave dipole antenna has not been detailed nor reported, either in texts or journals. Such an analysis is very significant, in order to understand more about this antenna's properties and potential applications for exploiting its high-gain benefits. The paper presents an analysis of the radiation resistance and gain of the full-wave-dipole antenna. This involves special integrations in the mathematics     

Kinetic and regeneration studies of photocatalytic magnetic separable beads for chromium (VI) reduction under sunlight

Physical adsorption and photocatalytic reduction of Cr(VI) in magnetic separable beads were investigated. In order to elucidate the kinetics of photocatalytic process, operating parameters such as catalyst dosage and the initial concentration were examined in detail. It was observed that the reduction rate of Cr(VI) increased with an increase in the catalyst loading, as this translated into an increase in the number of available active sites. Critical scrutiny of the percentage of the initial reduction rate versus time at various initial concentration of Cr(VI) revealed that the rate of substrate conversion decreased as the initial concentration increased. The kinetic analysis of the photoreduction showed that the removal of Cr(VI) satisfactory obeyed the pseudo first-order kinetic according to the Langmuir-Hinshelwood (L-H) model and the absorption of Cr(VI) on the magnetic beads surfaces was the controlling step in the entire reduction process. Furthermore, desorption experiments by elution of the loaded gels with sodium hydroxide indicated that the magnetic photocatalyst beads could be reused without significant losses of their initial properties even after 3 adsorption-desorption cycles.