Open Access Short Research Article

Geometry and Topology-based Segmentation of 2-Manifold Triangular Meshes in R3

Stella Orozco, Arno Formella, Carlos A. Cadavid, Oscar Ruiz - Salguero, Maria Osorno

Current Journal of Applied Science and Technology, Page 1-14
DOI: 10.9734/BJAST/2017/32827

This manuscript reports a geometrical and a topological methods to segment a closed triangular 2-manifold mesh M ⊂ R3. The mesh M does not self-intersect) and has no border (i.e. watertight. Geometrical and topological segmentation methods require a Boundary Representation (BRep) from M. Building the BRep for M uniforms the triangle orientations, and makes explicit triangle and edge - counter edge adjacency. In the context of Reverse Engineering, the sub-meshes produced by the segmentation are subsequently used to fit parametric surfaces, which are in turn trimmed by the sub-mesh boundaries (forming FACEs). A Full Parametric Boundary Representation requires a seamless set of FACEs, to build watertight SHELLs. The fitting of parametric surfaces to the triangular sub-meshes (i.e. sub-mesh parameterization) requires quasi-developable sub-meshes.As a result, our geometric segmentation places 2 neighboring triangles in the same sub-mesh if their dihedral angle is π ± η for a small η (angle between their triangle normal vectors is a small η angle). On the other hand, our topological segmentation heuristic classifies triangles in a common sub-mesh if the value of the First eigenfunction of the triangulation graph Laplacian in these triangles falls in the same bin of a histogram formed with the eigenfunction values. The segmentation will obviously depend on the histogram bin distribution. The data sets processed indicate that geometrical segmentation is more convenient for mechanical parts with analytical surfaces. Conversely, topological segmentation works better for organic or artistic shapes. Future work is needed on the tuning of both the dihedral threshold η (for geometrical segmentation) and on the bin distributions of the eigenfunction (for topological segmentation).

Open Access Original Research Article

Effect of Vegetable Based Lubricants on Equal Channel Angular Extrusion Pressure

T. M. Azeez, I. Uchegbu, O. L. Rominiyi

Current Journal of Applied Science and Technology, Page 1-8
DOI: 10.9734/BJAST/2017/32584

This research aimed at investigating vegetable based lubricant as a replacement for chemical based lubricants on extrusion pressure of equal channel angular extrusion of Aluminum. In the process, aluminum alloy (Al 6063) was heated at 350°C for one hour, machined and cut to billets size of 11.95 m x 11.95 m x 40 m (l × b × h). The billets were extruded through die of 12 mm x 12 mm channel cross-section area, the channel angle was 60°. Four vegetable based lubricants namely jatropha, neem, castor and cotton seed oils were used. The die was centrally located on the bed of vertical hydraulic testing machine and the billet was inserted into the entrance channel. Lubrication was applied to the billet to decrease its friction and with the channel inner wall. The ram displacement per plunger speed was 1 mm per 1 second respectively. For each lubricant, four samples were extruded through ECAE die to confirm the repeatability of the results and the average values of the extrusion pressure were computed. The results were compared to the sample extruded via conventional lubricants. It was discovered of all the extruded samples, jatropha oil gave the least extrusion pressure of 83 kN, cottonseed oil extruded at 104 kN  and castor oil at 151.4 kN while neem oil require the highest pressure at 220.9 kN. The chemical based lubricants that serve as the control from the literature gave the extrusion pressure of 81 kN. It can be concluded that the oil from jatropha seed is the best in terms of extrusion pressure and can effectively replace the chemical based lubricants.

Open Access Original Research Article

Soil Organic Carbon Concentrations and Stocks under Maize/Legume Cropping System in Alfisols of a Savanna Zone, Nigeria

Odunze Azubuike Chidowe, Musa Yusuf Destiny, Abdulkadir Aisha

Current Journal of Applied Science and Technology, Page 1-12
DOI: 10.9734/BJAST/2017/32538

Carbon sequestration in soil aggregates and Carbon stock (SOC) under Maize-Legume Cropping system in a Northern Guinea Savanna Alfisol, Nigeria trial was conducted in 2014 and 2015 cropping seasons. The experiment was a randomized complete block design (RCBD), replicated three times and treatments used were: Sole Maize (M), Desmodium (D) and Soybeans (S); Maize-soybeans intercrop (MS), Maize-Desmodiumintercrop (MD), Maize Strip cropped with Soybean (MS 2:4) and Maize Strip cropped with Desmodium (MD 2:4). Data obtained were evaluated for Organic carbon, carbon stock, Bulk density and mean weight diameter of aggregates in the soil. Results obtained show that Mono-crop (Sole) Maize treatment gave significantly higher BD than other treatments at 8WAP and 16WAP, suggesting that soils under sole maize were degraded for sustainable crop production. Organic carbon sequestered over 2014 to 2015 was least under MD and highest under MD2:4 treatments and mean carbon stock sequestered in the macro and micro aggregates was highest under MD 2:4 (28.35 t Cha-1) and least under MD (8.82 t Cha-1). Soil organic carbon (SOC) sequestered in macro aggregates under MS (1.38 gkg-1) were significantly higher than the other treatments. Maize/Desmodium 2:4 treatment was inferred to have best improved soil conditions (quality/health) for sustainable crop production, mitigate climate change and global warming by sequestering carbon better than the other treatments.

Open Access Original Research Article

A Comparative Study of the Glycating Power of Simple Carbohydrates in the Maillard Reaction by Means of Conceptual DFT Descriptors

Juan Frau, Daniel Glossman-Mitnik

Current Journal of Applied Science and Technology, Page 1-12
DOI: 10.9734/BJAST/2017/32795

This study features an assessment of multiple density functionals in calculating the molecular structures and inherent properties in simple carbohydrates participating in nonenzymatic glycation involving amino acids and proteins in Maillard reactions. Calculations of chemical reactivity descriptors is attained in each molecular system using Conceptual DFT. A cross-sectional comparison of results obtained through ∆SCF procedure is attained to check for accuracy and validity of the density functional in “Koopmans in DFT" (KID) procedure. The Fukui function indices and condensed dual descriptor ∆f(r) are used to examine the active sites where nucleophilic and electrophilic attacks occur. The assessment identifies several relationships involving glycating power and reactivity descriptors. The latter are found capable for predicting glycating behavior in complex carbohydrates.

Open Access Original Research Article

Evaluation of Stem Biomass and Carbon Density of Four Deciduous Tree Species in Northern Plains of India Using Regression Modeling

Naseer A. Mir, P. A. Sofi, Gowher N. Parrey, T. A. Rather, Hilal A. Bhat

Current Journal of Applied Science and Technology, Page 1-9
DOI: 10.9734/BJAST/2017/31829

Assessment of carbon stock in trees is generally based on allometric equations relating either volume, or biomass, or carbon to DBH. The carbon density of different tree parts is not often measured directly, but generally assumed to be 50% of dry weight. In this study we try to analyze those assumptions and determined the effect different regression equations on carbon sequestration for Tectona grandis, Vachellia nilotica, Madhuca indica, Dalbergia sissoo. The present study aims to estimate the above-ground biomass (AGB) and carbon sequestration in 18 sampling plots of 30 × 30 m2 size, at different sites in northern plains (Uttar Pradesh) India. Two regression models were used for each species; one using DBH only (Method 1) and the other using DBH and height (Method 2). The best fit models were chosen on the basis of highest R2. The DBH, AGB and carbon density yielded a positive relationship for all the species. Apart from Model D1h, all R2 values for models developed with our data (both DBH and height) were above 99%. The R2 values for models developed with DBH only were below 90%, least for model M1 (77.6%) The co-efficient for DBH was not significant in Model D1h and M1h, but the co-efficient for DBH and height was significant at the 5% level of significance for all other coefficients in all other models. The estimated stem AGB was maximum for Tectona grandis with 376.2 and 355.63 t/tree with carbon sequestration of 621.25 and 587.50 kg/ha for the equation T1 and T2H respectively; whereas minimum AGB was recorded for Dalbergia sisoo with 221.55 and 211.58 t/ha and carbon sequestration of 362.93 and 349.65 kg/ha. The AGB and carbon sequestration estimation obtained in this study represents a more realistic picture of biomass of region.

Open Access Original Research Article

Evaluation of Noise Levels in Oil Mill Market and Its Environs, Port Harcourt, Nigeria

John N. Ugbebor, B. Yorkor, Joy N. Nwogu

Current Journal of Applied Science and Technology, Page 1-11
DOI: 10.9734/BJAST/2017/33248

Noise in market places can be a matter of public concern to traders and other close residents. Exposure to excessive noise has the ability to cause both physiological and psychological effects in humans. A systematic noise survey was conducted at different locations within Oil Mill Market and Eleme Junction in Port Harcourt, Rivers State, Nigeria. Modelling of noise levels within the market area is presented. A cumulative noise level of 108.6dB (A) was obtained along East-West Road between Oil mill market and Eleme junction; Eleme junction showed cumulative noise level of 105.4dB (A); also, Elelenwo by Oil-Mill market showed noise level of 103.8dB (A); while, Oil-Mill Market showed cumulative noise level of 108.2dB (A). Computed mean noise value is 109±3dB (A), computed Leq index is 123.6±2.3dB (A), while computed noise pollution level is 117.1dB (A). Findings showed that use of grinding machines and generators within the market accounted for 27% of noise within the market; mobile sellers contributed 26%; while vehicular movement along the East-West highway and Eleme junction constituted 19% of the noise produced in the area. High noise pollution prevails within the market environment withpotentialhealth effects on traders and the public. State and/or Local Governments should carry out awareness campaigns among traders on the effects of noise on their health. Noise control by-laws or regulations should be enforced so as to regulate the activities of mobile advertisers or sellers.

Open Access Original Research Article

Nursery Performance of Male Clones of Poplar (Populus deltoides Bartr.) under Temperate Conditions of Kashmir Valley

Ashfaq A. Mir, T. H. Masoodi, Naseer A. Mir, T. A. Rather, P. A. Sofi

Current Journal of Applied Science and Technology, Page 1-8
DOI: 10.9734/BJAST/2017/32669

Fifteen (15) male clones of Populus deltoides (Twelve clones procured from WIMCO and three local clones) were evaluated in nursery to study their growth performance. The investigations revealed that significant interclonal variation exists for all the selected growth characters. The plant height varied from 179 to 284 cm, collar diameter 17.13 to 27.51 mm, number of branches 3 to 14 and number of leaves 59 to 272 plant-1. The leaf area plant-1 also varied between a minimum of 50 to a maximum of 118 cm2 and the internodal length between 3.28 to 5.77 cm. Significant interclonal variation also exhibited in fresh and dry total biomass of seedlings. Based on the morphological growth, the ranking index for these clones was developed and the clones viz., L-34 (TC), L-34 and 65/27 performed best in terms of ranking index with values 133, 126 and 123 respectively. These clones can be used for mass multiplication and for gradual replacement of female cultivars in the Kashmir Valley.