Aims: Flow over gravel dunes is investigated. Measured velocity and Reynolds stress distributions over gravel dunes are compared to those for sand bedforms under similar geometric and hydraulic conditions. Place and Duration of Study: Experiments were carried out at the hydraulics laboratory at Isfahan University of Technology, Iran, during the summer of 2012. Results: Results show that the dune surface roughness plays a significant role in the stream wise velocity near-bed region (z/H <0.3), but it has no influence on the velocity distribution in outer flow region (z/H>0.3). While flow separation is clear in the troughs of sand bedforms, it is not evident over gravel bedforms and this has important implications when considering drag and flow resistance. The convex shapes of the Reynolds shear stress distribution over the trough and stoss regions of gravel bedforms are comparable to those of sand bedforms for z/H>0.5, but significant differences are found for z/H<0.5. The greater surface roughness of gravel dunes increases peak values of Reynolds shear stresses over the trough, crest and stoss regions.
The corrosion performance of electrogalvanised steel sheets pre-treated with a Cr3+ or Cr+6-based conversion layer and then covered with polyurethane-waterborne topcoat paint has been studied. The pre-treated metallic panels were coated with one of the three tested polyurethane (PU) topcoat paints, in which the dispersion type was the formulation variable. The pigment was TiO2 (rutile) with a PVC value of 10. Before and after the immersion in 0.05 M NaCl (pH 5.70) or 0.1 M Na2SO4 (pH 6.36) solutions, replicates of the different samples were subjected to standardized tests (porosity, gloss and color, hardness, flexibility). During the immersion, blistering and rusting degrees were evaluated through periodical visual inspections, while the coated steel performance was monitored by Electrochemical Impedance Spectroscopy (EIS) measurements. Initial (dry) and final (wet) paint adhesion was also determined. EIS data were interpreted and discussed in terms of the time dependence of the electrical (paint coating) and electrochemical (steel substrate) parameters associated with interfacial processes describing the metal/paint system deterioration. According to the electrochemical properties, visual inspection and standardized tests results, it was concluded that the studied polyurethane-based polymeric films applied on pretreated electrogalvanised steel provided a very effective protection against corrosion as a result of their excellent barrier properties.
Hydrilla verticillata (L.f.) Royle twigs were subjected to HgCl2 (10, 50, 100 and 200 mg/L) for 3 h under light and dark conditions. There was significant loss in total chlorophyll, soluble protein and ascorbic acid contents in the twigs with increased Hg concentrations in the medium. Superoxide dismutase (SOD) activity increased in a concentration dependant manner indicating the increased protection against superoxide radical under Hg stress but at the same time the generation of higher amount of H2O2 as dismutation product was also favoured. At lower concentration, there was increase in catalase (CAT) activity but it declined significantly towards higher concentrations of Hg as a result the protection against H2O2weakened. Even though there was increase in peroxidase (POX) activity, it could not be attributed to efficient H2O2 scavenging. Malondialdehyde (MDA) content in the tissues increased which suggested that there was imposition of oxidative stress due to Hg. The addition of antioxidant (ascorbate) to the medium reduced the toxic effects. The results suggest that the Hg induced oxidative stress was probably due to alterations in the activities of key antioxidative enzymes viz SOD, CAT and POX. Therefore, increased antioxidant efficiency could increase the tolerance of the plant to the metal and thereby it could be a better candidate for Hg bioaccumulation in polluted water bodies.
Aims: Studies were conducted on the production and quality evaluation of glucose syrup from three different types of biomass: Eucalyptus sawdust (soft wood), Mahogany sawdust (hard wood), and Rice husk. Study Design: A 3x1x1x3 Factorial design was used. Place and Duration of Study: Department of Food science and Technology, University of Agriculture, Makurdi, Nigeria, between October 2009 and October 2013. Methodology: The biomass samples, after thorough cleaning, were pretreated with 1% Sodium hydroxide (NaOH) solution and then hydrolyzed with 5% Hydrogen tetraoxosulphate six (H2SO4) in an autoclave at 1200C for 30 min. The extract was filtered to obtain clear glucose solutions, which were evaluated for some physico – chemical and nutritional properties using standard methods of analysis. Results: There were significant differences (P = .05) in the yield and glucose content of the syrups, with values ranging from 59.33% to 70.40% and 21.63% to 25.20% respectively, with Eucalyptus sawdust having the least value and Rice husk the highest. There were also significant differences (P = .05) in the nutritional properties with values ranging from 1.60% to 2.01% (crude fat), 2.40% to 3.01% (ash), 4.50% to 5.08% (crude protein), 81.57% to 87.99% (moisture content), and 3.11% to 9.60% (carbohydrate). Rice husk had the highest moisture, protein and carbohydrate contents, while soft wood had the highest fat and ash contents. Mineral and heavy metal content also showed a similar trend. Toxicant content also differed significantly (P= .05) in the different biomass samples with soft wood and rice husk giving higher and lower values respectively. Conclusion: Biomass therefore has the potential of being converted to useful products such as glucose syrup. Rice husk produced the best quality glucose with higher yield, followed by soft wood and hard wood in that order.
Very Simple Optimization (VSO) is introduced as a new a new global search design and optimization algorithm that is applied to a seminal antenna optimization problem: achieving uniform hemispherical coverage in a dipole-loaded monopole. The VSO-optimized monopole's performance is compared to genetic algorithm and hill-climber designs, and VSO is tested against two suites of benchmark functions and several other algorithms.
Face recognition based only on the visible spectrum has shown difficulties in performing consistently in uncontrolled operating conditions. Face recognition using different imaging modalities, particularly infrared imaging sensors has become an area of growing interest in recent years. In this paper, we present a new technique for face recognition that exploits the local statistical characteristics of a thermal image. The “whole” face image is divided into components of different sizes. The statistical features of these components, beside the “whole” image are combined together using fusion methods. Decision level fusion finds a combination of multiple statistical patterns to produce an integrated result that is enhanced in terms of information content for pattern recognition and classification. Local representations offer robustness against variability due to the changes in localized regions of the objects. The proposed feature vector consists of different moments’ calculations and thermal components’ histograms. The features found from local analysis are less sensitive to illumination changes, easier for estimating the rotations, have less computational burden and have the potential to achieve higher correct recognition rates. The experimental results reveal that the new system can achieve a success rate of 96.4% when implemented on the AIAOU Database.
Aims: The aim of this investigation was to develop a methodology that provides insights to clean up environmental pollution caused by the ever increasing amount of waste plastic materials. The procedure, however, would be practical whenever it is economically advantageous. Thermal cracking of laboratory safety glove (LSG), without catalyst, to useful chemicals is an important part of this research which is reported here. Study Design: To design the experimental procedure, we primarily concentrated on the thermal stability of the LSG by bearing in mind the results of thermo gravimetric analysis (TGA). Based on such results the appropriate set-up for the decomposition of the LSG was designed. Place and Duration of Study: The study was done in the Department of Biological and Physical Sciences at South Carolina State University (SCSU), Orangeburg, SC, USA, during the summer of 2013. Methodology: The thermal cracking process without catalyst was used to convert LSGs into useful liquid and solid chemicals. The LSGs were pushed into the reactor one by one without cutting. Prior to pyrolysis, the thermal stability of materials were determined by thermo gravimetric analysis (from 50ºC to 800ºC) with a heating rate of 10ºC/min while the samples were purged with 10 mL/min argon. The condensed liquids were analyzed by a Shimadzu GC-MS model GCMS-QP 2010s using helium as the mobile phase. Results: The thermal stability of the LSG both powdered and powder-free was very similar as was expected since it depended on the nature of constituent polymers. The highest decomposition rates were observed at temperatures around 410ºC. The 15% leftover of the powder-free LSG were less than leftover of powered LSG (30%) at 500ºC, in the same way the 18% leftover ashes of powdered LSG was higher than 7% ashes of powdered free LSG at 800ºC. The GC-MS chromatogram of pyrolysis liquids indicated over 350 chemicals. The most abundant compound of pyrolysis was HCl, as was expected from the chemical constituents of chlorinated plastics, followed with eight member carbon isomers. Also, a variety of phthalic acid derivatives with high concentration were recognized in all samples. Conclusion: The liquids obtained from pyrolysis of LSGs were a complex mixture of hydrocarbons and cyclic compounds. Also, the liquids were saturated with inorganic and organic acids, esters and anhydrides. Therefore, the refinement of liquids resulting from pyrolysis is of necessity to obtain a quality fuel. Also, the condensed liquids contained highly reactive chemicals such as acids, alcohols and alkene, which made them unsuitable fuel for internal combustion engines prior to refinement.
Yellow Oleander (Thevetia Peruviana) oil has been extracted and analyzed relevant to lubrication. Oil was extracted from yellow oleander seeds using mechanical expression and solvent extraction methods. Samples generated from these oils were subjected to chemo-physical analysis. Analysis of chemo-physical properties (such as viscosity, specific gravity, viscosity-temperature coefficient and fire point among others) was carried out using simple laboratory equipment. Results obtained showed that yellow oleander oil have properties that fall within the range of standard oil lubricants. High flash and fire points of 350°C and 375°C respectively were obtained. Free fatty acids content of 5.61% against a standard range of 35%-50% for natural oils. Specific gravity of 0.89-0.92 was obtained against a standard range of 0.76-0.92 for oil lubricants. The oil can be used as lubricant in environmentally sensitive areas such as total loss lubrication and marine ecosystems with associated positive environmental and economic impact.
The variations in growth, powdery mildew and anthracnose incidence and biochemical changes in Thompson Seedless grapevines grafted onto Dog Ridge and 110-R rootstocks in comparison to the own rooted grape vines was investigated. Bud sprouting after pruning was achieved earlier in case of own-rooted vines. However, the vine growth pattern studied in terms of the shoot length, inter nodal length, shoot diameter and leaf area was highest in case of vines grafted onto Dog Ridge. Foliar powdery mildew and anthracnose incidence was highest in vines grafted onto Dog Ridge and own-rooted vines, respectively. The disease incidence was recorded least in vines grafted onto 110-R. The biochemical analysis was also influenced by the rootstocks. The leaves of vines grafted onto Dog Ridge recorded the highest reducing sugars and protein contents and the least total sugars and phenolic contents. The vines grafted onto 110-R topped in total phenolic contents and other phenolic derivatives.