The sufficient descent condition of nonlinear conjugate gradient method

Non-linear conjugate gradient methods has been widely used instrumental in solving large scale optimization. These methods has been proved that only required very low memory other than its numerical efficiency. Thus, many studies have been conducted to improve these methods to find the most efficient method. In this paper, we proposed a new non-linear conjugate gradient coefficient that guarantees sufficient descent condition. Numerical tests indicate that the proposed coefficient is better than the three classical conjugate gradient coefficients

Biodegradation of hydrocarbons in soil by microbial consortium

The bioremediation of hydrocarbon in contaminated soils by mixed cultures of hydrocarbon-degrading bacteria was investigated. The mixtures or consortia of bacteria, denoted as Consortium 1 and Consortium 2 consisted of 3 and 6 bacterial strains, respectively. Bacterial strains used in this study were from the Center for Research in Enzymes and Microbiology (CREAM) collection of strains, at Universiti Putra Malaysia, and were isolated from hydrocarbon-contaminated soil samples by enrichments on either crude oil or individual hydrocarbons as the sole carbon source. The strains were selected based on the criteria that they were able to display good growth in crude oil, individual hydrocarbon compounds or both. Their ability to degrade hydrocarbon contamination in the environment was investigated using soil samples that were contaminated with diesel, crude oil or engine oil. Consortium 2, which consisted of 6 bacterial strains, was more efficient at removing the medium- and long-chain alkanes in the diesel-contaminated soil compared to Consortium 1. Further, Consortium 2 could effectively remove the medium- and long-chain alkanes in the engine oil such that the alkanes were undetectable after a 30-day incubation period. Consortium 2 consisted predominantly of Bacillus and Pseudomonas spp

Development of coating materials from liquid wax esters for wood top-based coating

Of late, UV-curable products are gaining attention in the wood industry because of the effectiveness and efficiency of this method. UV-curable surface coatings are widely used because of their excellent properties and because they are environmentally friendly products. In this study, immobilized Candida antarctica lipase B was used to catalyze formation of liquid wax esters, such as adipate esters, via a solvent-free process. The adipate esters formed were then used as UV-curable reactants in the wood coating formulations, consisting of epoxy acrylate, additives, and a photoinitiator. The performance of the products was evaluated by coating them onto glass tiles (using gel content, hardness, and scratch resistance tests) and wood panels (using adhesion, impact, and heat resistance tests). The coated film from this formulation performed well during the evaluation tests. The gel content exhibited more than 90% polymerization, while the pendulum hardness gave a value of 55.25%. Both analyses were significant in determining the effect of irradiation cycles. A scratch test was also carried out to verify the resistance of the coating. The maximum weight load which can be resisted by the wax esters formulation is 4.5 N

Fatty acids and terpenoids from Canarium odontophyllum MIQ. Leaf and their antioxidant and cytotoxic effects on UVB-induced immortalized human keratinocytes cells (HACAT)

The study evaluated the antioxidant capacity of hexane extract of Canarium odontophyllum Miq. leaf; its fatty acids and terpenoids content; and cytotoxic effects on UVB-induced human keratinocytes (HaCaT). FRAP assay was used to determine antioxidant capacity. GC-MS analysis to identify the fatty acids and terpenoids’ in the hexane extract of Canarium odontophyllum Miq. leaf. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was carried out to measure the cytotoxic effects of the extract on UVB-induced human keratinocytes. Serial doses of up to 1000 µg/mL extract were administered before UVB irradiation of the cells. FRAP assay showed the extract was found to exhibit antioxidant activity but no significant difference in ascorbic acid equivalent antioxidant capacity (AEAC) between dose 500 µg/mL (5.00 ± 0.35 AEAC) and 1000 µg/ mL (5.70 ± 0.29 AEAC) extract. GC-MS analysis showed the extract contained 88.93% of fatty acids and terpenoids, especially n-hexadecanoic acid, spathulenol, and phytol. MTT assay showed no IC50 value for the tested extract dose on UVB-induced HaCaT. Thus, the results suggest the potential application of hexane extract of C. odontophyllum Miq. leaf in terpenoids’ studies. In-depth research and isolation of compounds of interest should be done to develop it as a viable medical phytotherapeutic agent

GC-MS ANALYSIS OF TERPENOIDS FROM LEAVES OF Canarium odontophyllum Miq.(DABAI)

Terpenoids are defined as secondary metabolites with carbon backbone molecular structures consisting of isoprene (2-methylbuta-1, 3-diene) units. They demonstrate important biological activities, such as antibacterial, antiviral, antimalarial, antiinflammatory, anticancer and cholesterol synthesis inhibition activities. Canarium odontophyllum Miq. or locally known as “dabai” is an endemic plant in Sarawak, Malaysia. Its leaf compositions were examined by using the GC-MS analysis in order to compare and contrast their volatile terpenoids constituents. The terpenoids content were 36.67% and 14% for hexane and ethanol extracts, respectively. nHexadecanoic acid, phytol and octadecanoic acid were the major terpenoids constituents from the leaves of C. odontophyllum Miq. n-Hexadecanoic acid (20.22%), phytol (8.74%) and octadecanoic acid (7.54%) were found to be predominant in the hexane extract, while phytol(21.02%) and n-hexadecanoic acid (14.52%) were major constituents in the ethanol extract. The C.odontophyllum Miq. leaf constituents are also related to their biological activities and would offer promising therapeutic effects. Further investigation should be conducted to develop it as apotential therapeutic drug

GC-MS ANALYSIS OF TERPENOIDS FROM LEAVES OF Canarium odontophyllum Miq.(DABAI)

Terpenoids are defined as secondary metabolites with carbon backbone molecular structures consisting of isoprene (2-methylbuta-1, 3-diene) units. They demonstrate important biological activities, such as antibacterial, antiviral, antimalarial, antiinflammatory, anticancer and cholesterol synthesis inhibition activities. Canarium odontophyllum Miq. or locally known as “dabai” is an endemic plant in Sarawak, Malaysia. Its leaf compositions were examined by using the GC-MS analysis in order to compare and contrast their volatile terpenoids constituents. The terpenoids content were 36.67% and 14% for hexane and ethanol extracts, respectively. nHexadecanoic acid, phytol and octadecanoic acid were the major terpenoids constituents from the leaves of C. odontophyllum Miq. n-Hexadecanoic acid (20.22%), phytol (8.74%) and octadecanoic acid (7.54%) were found to be predominant in the hexane extract, while phytol(21.02%) and n-hexadecanoic acid (14.52%) were major constituents in the ethanol extract. The C.odontophyllum Miq. leaf constituents are also related to their biological activities and would offer promising therapeutic effects. Further investigation should be conducted to develop it as apotential therapeutic drug

Mechanical degradation model of porous fe scaffold: simulation approach

This paper proposes a simple degradation model that estimates morphological changes in pure iron scaffolding due to surface erosion. The main contribution of this work is to estimate the degradation of porous pure iron scaffolding and analyze the impact of morphological changes on mechanical properties. In this study, the pure iron scaffolding model was designed in CAD software with 3 different porosity such as 30%, 41%, and 55% respectively. The geometry images of CAD models with a resolution of 3316 x 5530 pixels are captured layer by layer with a thickness of 0.02 mm. The purpose of this method is to replace the function of the u-CT scanning technique. Two-dimensional morphological erosion is applied to reduce the number of pixels of the image model. This erosion process is adjusted iteratively with increasing number of pixels to erode the image model until the volume of the scaffold after reconstruction matches the volume of the model undergoing mathematical calculations. Their changes in the volume of scaffold geometry and degradation of mechanical properties were evaluated using finite element analysis. This study found that mechanical properties such as elastic modulus and yield strength decreased systematically during the 19 week degradation period. In addition, deformation analysis is performed on models based on finite element analysis