Theoretical Study of the [4+2] Cycloaddition Reaction of Trifluoroethylene with Five-membered Chalcogens Heterocyclic Compounds

[4+2] cycloaddition reaction has enormous significant in organic chemistry synthesis reactions and yet remains unexplored for the synthesis of fluorine-containing compounds. A density functional theory study of the stereo- and regioselectivity of the [4+2] cycloaddition reaction of trifluoroethylene with furan, thiophene, and selenophene was carried out in the gas phase. The B3LYP functional is used throughout in combination with 6-31G(d) basis set. The analysis of stationary points and the energetic parameters indicates that the reaction mechanism is concerted and confirms that the exo-adducts are thermodynamically and kinetically more favored than endo-adducts. The calculated branching ratio indicates that the exo-adducts have the higher percent yield than endoadducts and the yield of endo-adducts is increased only slightly on proceeding from furan, through thiophene, and onto selenophene. The analysis of the frontier molecular highest occupied molecular orbital (MO) and lowest unoccupied MO orbitals indicates that the exo-adducts are more stable due to their higher energy gab. The reaction energies were compared to the MP2/6-31G(d) and CCSD(T)/6-31G(d) calculations

Preparation of Some Eco-friendly Corrosion Inhibitors Having Antibacterial Activity from Sea Food Waste

Chitosan is one of the important biopolymers and it is extracted from exoskeletons of crustaceans in sea food waste. It is a suitable eco-friendly carbon steel corrosion inhibitor in acid media; the deacetylation degree of prepared chitosan is more than 85.16 %, and the molecular weight average is 109 kDa. Chitosan was modified to 2-N,N-diethylbenzene ammonium chloride N-oxoethyl chitosan (compound I), and 12-ammonium chloride N-oxododecan chitosan (compound II) as soluble water derivatives. The corrosion inhibition efficiency for carbon steel of compound (I) in 1 M HCl at varying temperature is higher than for chitosan and compound (II). However, the antibacterial activity of chitosan for Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, and Candida albicans is higher than for its derivatives, and the minimum inhibition concentration and minimum bacterial concentration of chitosan and its derivatives were carried out with the same strain

Developing a Land Suitability Index for Agricultural Uses in Dry Lands From Geologic Point of View Using GIS - a Case Study From Jordan

DOI:10.17014/ijog.2.2.63-76In the context of the study, a Multi-criteria evaluation (MCE) in GIS was used in developing suitability index to optimize suitable lands for agricultural uses and seasonal farming in dry lands from geologic point of view. This study was performed in the areas between Mafraq and Zarqa Cities in Jordan which are classified as arid lands. The study aims at protecting groundwater from pollution, reducing soil salting, reducing irrigation water loss caused by evaporation, and increasing crop productivity. The geo-environmental parameters of the named area including geology, groundwater depths, soil depths and textures, climatic conditions, topographic settings, and groundwater vulnerability conditions were mapped and converted into layers with special rates, given weights, and then modeled using the multi criteria evaluation (MCE) option, using Decision Making Modeling in IDRISI (GIS software) to reach at the best choice of lands for agricultural activities, and also to determine which of these lands are suitable for summer farming and which are suitable for winter farming

Molecular scale cure rate dependence of thermoset matrix polymers

This manuscript demonstrates the molecular scale cure rate dependence of di-functional epoxide based thermoset polymers cured with amines. A series of cure heating ramp rates were used to determine the influence of ramp rate on the glass transition temperature (Tg) and sub-Tg transitions and the average free volume hole size in these systems. The networks were comprised of 3,3′-diaminodiphenyl sulfone (33DDS) and diglycidyl ether of bisphenol F (DGEBF) and were cured at ramp rates ranging from 0.5 to 20°C/min. Differential scanning calorimetry (DSC) and NIR spectroscopy were used to explore the cure ramp rate dependence of the polymer network growth, whereas broadband dielectric spectroscopy (BDS) and free volume hole size measurements were used to interrogate networks’ molecular level structural variations upon curing at variable heating ramp rates. It was found that although the Tg of the polymer matrices was similar, the NIR and DSC measurements revealed a strong correlation for how these networks grow in relation to the cure heating ramp rate. The free volume analysis and BDS results for the cured samples suggest differences in the molecular architecture of the matrix polymers due to cure heating rate dependence.Qatar University’s Center for Advanced Materials’ Start-Up grant. AFOSR Award Number FA9550-13-1-0103; and Dr. Gregg Bogucki and Dr. Stephen Heinz from Boeing Research and Technology for their kind financial support and collaboration

Natural fiber reinforced poly(vinyl chloride) composites : a review.

Materials from renewable resources – also called biomaterials or ‘green’ materials – are presently gaining in importance worldwide. In these times of continuous increases in the price of crude oil and discussion of carbon dioxide (CO2) emissions, conventional plastics have reached a price level and a questionable image which promotes the search of alternatives. Natural fibers are a renewable natural resource and are biodegradable, which is an important characteristic for components that must be disposed of at the end of their useful life. They are recyclable and can be easily converted into thermal energy through combustion without leaving residue. In this study, we will discuss the natural fiber reinforced polyvinyl chloride composites, reinforcing effect, plasticization effect along with modification by coupling agents, properties, and applications based on composite materials. Also, the polyvinyl chloride-based composite materials with specific emphasis on effect of coupling agent, foamed polyvinyl chloride composites, and the effect of natural fiber reinforcement on its material properties will be reviewed. One of the best alternatives is natural fiber reinforced plastics composites. These are composites that are typically filled or reinforced with plant fibers, as well as plastics such as polyvinyl chloride or recently, even bioplastics

The critical level of vitamin D in childhood asthma

Objectives: Studies have suggested a significant link between vitamin D status and asthma. We sought to determine the cutoff level of25 hydroxy (25-OH) vitamin D that is significantly linked to asthma status in children.Methods: Our cross-sectional study comprised 90 asthmatic children, aged 2-18 years. They were evaluated clinically and classified according to asthma severity and control. Asthma control test (ACT) was performed in those aged above 4 years.Pulmonary functions were performed in cooperative children (n=59). Serum 25-OH vitamin D levels were measured by ELISA in all patients.Results: The study comprised 52 boys (57.7%) and 38 girls (42.3%) with mean age 7.03±4.36 years. Thirty-six patients (40%) had mild asthma, 37 (41%) moderate asthma and 17 (19%) had severe asthma. Forty-two patients (46.6%) had controlled asthma; 14 (15.6%) partially controlled and 34 (37.8%) had uncontrolled asthma. ACT score ranged: 11-26, with mean score: 18.9 ± 4.3 SD. Serum 25-OHvitamin D levels ranged between 2-48 ng/ml (mean± SD: 12.2 ± 9 ng/ml); levels were comparable among different grades of asthma severity (f= 1.975, p=0.145), while the uncontrolled asthma group showed the lowest levels (f=8.511, p <0.001). 25-OH vitamin D levels correlated positively with ACT score (r= 0.369, p= <0.001) but not with inhaled steroids doses or any of the pulmonary function parameters. A level of 7.5 ng/ml was associated with partial/completeuncontrol of asthma with 81 % sensitivity and 53 % specificity.Conclusion: 25-OH vitamin D levels below 7.5 ng/ml are associated with poor asthma status in children.Keywords: Asthma, allergy, children, severity, inhaled steroids, 25 hydroxy vitamin D

Micro-encapsulation of asphalt rejuvenators using melamine-formaldehyde

Asphalt pavement roads are exposed to traffic loading and natural elements such as rain, sunlight and oxidation, which result in decreasing their relaxation capabilities and the initiation of cracks. Innovative maintenance techniques such as developing microcapsules with rejuvenators have emerged in order to reverse the aging process in asphalt binder. The objectives of this study were to assess the effectiveness of an asphalt rejuvenator to reverse the aging process in asphalt binder and to develop a microencapsulation procedure for the tested asphalt rejuvenator. Properties such as size, shell thickness and morphology of the prepared microcapsules were evaluated by varying the production parameters, i.e. agitation rate, heating temperature, and Ethyl Methyl Acrylate (EMA) concentration. Three binder types were considered in the experimental program, two virgin asphalt binders that were aged in the laboratory and a binder extracted from Reclaimed Asphalt Pavement (RAP). Based on the results of the experimental program, it was concluded that the binder Performance Grade (PG) 70-22 was partially restored at both high and low temperature grades with the use of the rejuvenator. In contrast, the low temperature grade of the binder PG 76-22 and the high temperature grade of the RAP binder were restored with the use of the tested rejuvenator product. Microcapsules containing the rejuvenator were synthesized and a characterization process was conducted based on microcapsule properties such as diameter, shell thickness and morphology of the prepared microcapsules

Tetra­guanidinium bis­[citrato(3−)]cuprate(II) dihydrate

The asymmetric unit of the title compound, (CH6N3)4[Cu(C6H5O7)2]·2H2O, contains one-half of a centrosymmetric CuII complex anion, two guanidinium cations and a water mol­ecule. The CuII ion, lying on a crystallographic inversion center, is hexa­coordinated with two citrate anions in a distorted octahedral geometry. An intra­molecular O—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal structure, mol­ecules are linked into a three-dimensional framework by inter­molecular N—H⋯O and O—H⋯O hydrogen bonds

In Vitro and In Silico Antioxidant Efficiency of Bio-Potent Secondary Metabolites From Different Taxa of Black Seed-Producing Plants and Their Derived Mycoendophytes

Oxidative stress is involved in the pathophysiology of multiple health complications, and it has become a major focus in targeted research fields. As known, black seeds are rich sources of bio-active compounds and widely used to promote human health due to their excellent medicinal and pharmaceutical properties. The present study investigated the antioxidant potency of various black seeds from plants and their derived mycoendophytes, and determined the total phenolic and flavonoid contents in different extracts, followed by characterization of major constituents by HPLC analysis. Finally, in silico docking determined their binding affinities to target myeloperoxidase enzymes. Ten dominant mycoendophytes were isolated from different black seed plants. Three isolates were then selected based on high antiradical potency and further identified by ITS ribosomal gene sequencing. Those isolated were Aspergillus niger TU 62, Chaetomium madrasense AUMC14830, and Rhizopus oryzae AUMC14823. Nigella sativa seeds and their corresponding endophyte A. niger had the highest content of phenolics in their n-butanol extracts (28.50 and 24.43 mg/g), flavonoids (15.02 and 11.45 mg/g), and antioxidant activities (90.48 and 81.48%), respectively, followed by Dodonaea viscosa and Portulaca oleracea along with their mycoendophytic R. oryzae and C. madrasense. Significant positive correlations were found between total phenolics, flavonoids, and the antioxidant activities of different tested extracts. The n-butanol extracts of both black seeds and their derived mycoendophytes showed reasonable IC50 values (0.81–1.44 mg/ml) compared to the control with significant correlations among their phytochemical contents. Overall, seventeen standard phenolics and flavonoids were used, and the compounds were detected in different degrees of existence and concentration in the examined extracts through HPLC analysis. Moreover, the investigation of the molecular simulation results of detected compounds against the myeloperoxidase enzyme revealed that, as a targeted antioxidant, rutin possessed a high affinity (−15.3184 kcal/mol) as an inhibitor. Taken together, the black seeds and their derived mycoendophytes are promising bio-prospects for the broad industrial sector of antioxidants with several valuable potential pharmaceutical and nutritional applications

Traffic congestion detection for smart and control transportation management

The modern terrain of asphalt and motorways have become a standard of everyday life in a developed and developing nation. The rise in usage of motor vehicles has lead to the need to better regulate their use. These roadways have always been a way to transport us, our goods, and ideas throughout the age of homo sapiens up on mud to stone to brick, and now to petroleum distilled hydrocarbons. The goal of this project has been to be able to detect traffic congestions presence and levels via the analysis of the images gathered from traffic cameras that would indicate to the system the current flow status and give warning to the operators that could then relay the information to drivers within the affected area or take action themselves to resolve any issue if possible. Since the implementation of traffic monitoring systems are largely based on visual acuity of human operators using video monitoring cameras in tandem with other secondary sensing and monitoring devices in traffic control centers throughout the grid, it would be sensible to use the same system however enhancing it by the automation of the task of identifying and tallying vehicles flowing through the field of view of the camera at any given time. This would require the use of image processing algorithms and techniques within the bounds of the software tool MATLAB and other companion tools that would automatically indicate the presence of vehicles within a certain frame to further deduce the concentration of vehicle within the area