Prediction of water table in an alluvial aquifer using modflow

Groundwater is the main source of water in the Kingdom of Saudi Arabia (KSA). A larger part of groundwater is founded in alluvial (unconfined) aquifers. Prediction of water table elevations in unconfined aquifers is very useful in water resources planning and management. During the last two decades, many aquifers in different regions of the KSA experienced significant groundwater decline. The declines in these aquifers raised concerns over the quantity and quality of groundwater, as well as concerns over the planning and management policies used in KSA. The main objective of this study was to predict water table fluctuations and to estimate the annual change in water table at an alluvial aquifer at wadi Hada Al Sham near Makkah, KSA. The methodology was achieved using numerical groundwater model (MODFLOW). The model was calibrated and then used to predict water table elevations due to pumping for a period of 5 years. The output of the model was found to be in agreement with the previous records. Moreover, the simulation results also show reasonable declination of water table elevations in the study area during the study period

Nonlinear Parameter Estimation for Multiple Site-Type Polyolefin Catalysts Using an Integrated Microstructure Deconvolution Methodology

The microstructure of polyolefins determines their macroscopic properties. Consequently, it is essential to predict how polymerization conditions will affect polyolefin microstructure. The most important microstructural distributions of ethylene/alfa-olefin copolymers made with coordination catalysts are their molecular weight (MWD), chemical composition (CCD), and comonomer sequence length (CSLD). Several mathematical models have been developed to predict these microstructural distributions; reliable techniques to estimate parameters for these models, however, are still poorly developed, especially for catalysts that have multiple site types, such as heterogeneous Ziegler-Natta complexes. Most commercial polyolefins are made with heterogeneous Ziegler-Natta catalysts, which make polyolefins with broad MWD, CCD, and CSLD. This behavior is attributed to the presence of several active site types, leading to a final product that can be seen as a blend of polymers made on the different catalyst site types. The main objective of this project is to develop a methodology to estimate the most important parameters needed to describe the microstructure of ethylene/alfa-olefin copolymers made with these multiple site-type catalysts. To accomplish this objective, we developed the Integrated Deconvolution Estimation Model (IDEM). IDEM estimates ethylene/alf-olefin reactivity ratios for each site type in two-steps. In the first step, the copolymer MWD, measured by high-temperature gel permeation chromatography, is deconvoluted into several Flory’s most probable distributions to determine the number of site types and the weight fractions of copolymer made on each of them. In the second estimation step, the model uses the MWD deconvolution information to fit the copolymer triad distributions measured by 13C NMR and estimate the reactivity ratios per site type. This is the first time that MWD and triad distribution information is integrated to estimate the reactivity ratio per site type of multiple site-type catalysts used to make ethylene/alfa-olefin copolymers. IDEM was applied to two sets of ethylene-co-1-butene copolymers made with a commercial Ziegler-Natta catalyst, covering a wide range of 1-butene fractions. In the first set of samples (EBH), hydrogen was used as a chain transfer agent, whereas it was absent in the second set (EB). Comparison of the reactivity ratio estimates for the sets of samples permitted the quantification of the hydrogen effect on the reactivity ratios of the different site types present in the Ziegler-Natta catalyst used in this thesis. Since 13C NMR it is an essential analytical step in IDEM, triad distributions for the EB and EBH copolymers were measured in two different laboratories (Department of Chemistry at the University of Waterloo, and Dow Chemical Research Center at Freeport, Texas). IDEM was applied to both set of triad measurements to find out the effect of interlaboratory 13C NMR analysis on reactivity ratio estimation

MODELING OLEFIN POLYMERIZATION USING MONTE CARLO SIMULATION: DETAILED COMONOMER DISTRIBUTION

In recent years there have been many efforts to develop and expand the ability of mathematical models capable of describing polymerization systems. Models can provide a key competitive advantage for the industry and research in terms of production and technology development. As new resins are continuously produced to meet the requirement of final applications and processability, it is imperative to pursue strong polymer characterization with special attention to detailed analysis of polymer microstructure. The microstructure of polyolefin is defined by its distribution of molecular weight, chemical composition, branching topology, and stereoregularity. In this work, a Monte Carlo simulation model was developed to describe the polymerization mechanisms of olefin homopolymerization and copolymerization using single-site coordination catalyst. The mathematical model is meant to describe molecular weight and chemical composition distribution in copolymerization system. More specifically, this research work gives a detailed study of the molecular structure for ethylene- alfa-olefin copolymer. The chemical and physical properties of copolymers are influenced not only by their average composition, but also by the monomer sequence distribution along the polymer chains. Predicting the molecular weight and comonomer distributions can lead to a better understanding of the possible morphology in solid stated because they are considered to be the main structural parameters that affect the crystallinity of polymeric materials. As a consequence, final physical properties such as the tensile properties of a copolymer could be controlled by the ratio of crystalline species in the polymer. This work is considered to be a useful tool that enables us to understand and explore specific polymerization catalytic system. Being able to describe the short chain branching and the monomer sequence distribution as a function of chain length enables us to have a better control over semi-batch polymerization reactors

Probable Accumulation of Heavy Metals in Some Long-Term Irrigated Soils with Zarga River Water in Jordan

Heavy metals are bio-accumulated and bio-transferred both by natural and anthropogenic sources. The contamination by heavy metals in plants and water is one of the major issues to be faced throughout the world and requires attention because heavy metals above their normal ranges are extremely threatened to both plant and animal life. It was therefore of interest to conduct study to estimate levels of heavy metals in water and soil at Zarga River. Soil and water samples were also analyzed for physico-chemical parameters such as pH, and electrical conductivity. The aims of this study were to determine level of some heavy metals in water of Zarga River and to examine the probable accumulation of heavy metals in soils irrigated with Zarga river water in contrast with adjacent soils in the area. Results showed that the pH, EC, and water electrolytes (Ca, Mg, Na, K, Cl, HCO3, SO4) of water samples at the middle of the river (B) were higher than that at the beginning or at the end of the river . On the other hand, it was shown that the pH, EC, Cd, Pb, and Ni values of soil samples near the river (location A) were higher than other samples that were away including (B location) and (C location). Keywords: Soil, Heavy metals, Water, pH, Electrical conductivit

Synthesis of Multiwalled Carbon Nanotubes-Titania Nanomaterial for Desulfurization of Model Fuel

This work reported on the development of novel nanomaterials of multiwalled carbon nanotubes doped with titania (CNT/TiO2) for the adsorptive desulfurization of model fuel oils. Various analytical techniques such as field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR) were used for the characterization of the nanomaterials. The initial results indicated the effectiveness of the prepared CNT/TiO2 nanomaterials in removing sulfur compounds from model fuel oil. The adsorption of DBT, BT, and thiophene from model fuel onto the derived sorbents was performed using batch mode system. These CNT/TiO2 nanomaterials initially afforded approximately 45% removal of DBT, 55% BT, and more than 65% thiophene compounds from model fuels. The CNT/TiO2 nanomaterials provided an excellent activity towards interaction with organosulfur compounds. More experiments are underway to optimize the parameters for the adsorptive desulfurization processes. We believe that these nanomaterials as adsorbents will find useful applications in petroleum industry because of their operational simplicity, high efficiency, and high capacity

Observations of hydrographic properties, dissolved oxygen (DO) and chlorophyll-A (Chl-a) (phytoplankton biomass) within the exclusive economic zone (EEZ) of Qatar (central Arabian Gulf)

In situ observations of physical, chemical, and biological parameters of the Qatari water column were conducted to understand the temporal (seasonal) and spatial (regional) variability in the vertical and horizontal distribution of oceanographic properties within the exclusive economic zone (EEZ) of Qatar. Samples were collected from 5 different offshore shallow and deep stations covering the northern and eastern marine regions of the Qatar EEZ during two seasons: late summer (September 2014) and winter (January 2015). Eighteen (18) water samples were analyzed for temperature, salinity, density, dissolved oxygen concentration, dissolved oxygen saturation (DO%), and chlorophyll-a concentration (Chl-a). These data reveal several interesting and unique features that are related to surface warming that give rise to a large excess of evaporation over precipitation, resulting in the formation of several high salinity water masses. The deep offshore EEZ of Qatar was characterized by stratification (seasonal thermocline and pycnocline) during summer when deep water temperature was about 23.5°C (colder than the surface 32.6°C) where reduced stratification appeared to dominate in winter. Well-oxygenated water exists within the surface layer (0-23 m) during both summer and winter. Oxygen saturation layer (concentration 4.53 ml/l; saturation 94.49%) in the deep water extends to bottom (63 m) in winter however oxygen level falls below the summer thermocline (1.35 ml/l corresponding to 28.95% saturation) at Station 5 (63 m depth). Chl-a concentration was high in summer due to high primary productivity but remained sustained at moderate levels in winter. The procedures and methods were carefully applied to ensure the accuracy of the study results. In-situ measurements have high reliability in detecting hydrographic properties; however, it is costly, time consuming, requires ship time and as well as large number of scientific personnel and resources.qscienc

Evaluation of structural behavior of externally prestressed segmented bridge with shear key under torsion

Externally Prestressed Segmented (EPS) concrete beams are generally used in the construction of bridge structures. External Prestressed technique uses tendons that are placed completely outside the concrete section and attached to the concrete at anchorages and deviators only. Segmented bridge is a bridge built in short sections. Segmented bridge applies smart technique that is a part of an engineering management. EPS bridges are affected by combined stresses i.e., bending, shear, normal, and torsion stresses especially at the segments interface joints. Previous studies on EPS bridges did not include the effect of torsion in the load carrying capacity and other structural behavior. This paper presents an experimental investigation of the structural behavior of EPS bridged under combined bending, shear, normal, and torsion stresses. The aim of this paper is to improve the existing equation to include the effect of torsion in estimating the failure load of EPS bridge. A parametric study was carried out to investigate the effect of different external tendon layouts and different levels of torsion

ORAL CANDIDA ALBICANS COLONIZATION RATE IN FIXED ORTHODONTICS PATIENTS

Objectives:  The objective of this study was to assess the oral Candida albicans colonization ( OCAC)  in a cluster of teenagers and young adults while being treated with a fixed orthodontic appliance (FOA). Subjects and methods:  The investigational group was selected from orthodontic patients whom were examined clinically as soon as to get baseline information before active treatment.  The cluster included 210 patients; 45 males, 165 females (mean age 21.6 ± 4.5 years).  Clinical, demographic data and risk factors were collected in standard questionnaire then each individual was directed to carry out oral wash by a phosphate-buffered saline solution, which was expectorated and processed intended for the isolation of Candida species on Sabouraud’s dextrose agar. The isolated Candida species were identifying by culturing on chromogenic Candida agar and notice species-specific colony natures. Results:  The predominant Candida species isolated was C. albicans with OCAC rate equal to 13.8% extensively enhanced after the insertion of a FOA, as revealed by the oral rinse (P < 0.05) techniques. The results also revealed an increase of OCAC in male patients (24.4%) than female patients (10.9%),   21-25 years patients (17.1%), and regular smoking and Qat chewing were significant associated risk factors (OR=28.6, OR=10.7 respectively , P < 0.0001).  There was no significant association between C. albicans  colonization with oral hygiene in fixed Orthodontic patients. Conclusion:  As a whole, the current data suggest that the introduction of FOA is likely to promote OCAC. Moreover, it becomes visible that the routine oral hygiene procedures performed by these patients may not necessarily reduce OCAC while smoking and chewing Qat habits significantly increased OCAC in FOA. Also smoking and Qat chewing during FOA treatment should be banned if potential harmful effects are to be prevented. Further work with a larger sample size is required to confirm or deny these results.                      Peer Review History: Received 27 March 2020; Revised 20 April; Accepted 8 May, Available online 15 May 2020 Academic Editor: Ahmad Najib, Universitas Muslim Indonesia, Makassar, Indonesia, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 6.5/10 Average Peer review marks at publication stage: 8.0/10 Reviewer(s) detail: Dr. A.A. Mgbahurike, University of Port Harcourt, Nigeria, [email protected] Dr. Tamer Mohamed Ali El Habibi, Suez Canal University, Egypt, [email protected] Similar Articles: ORAL C. ALBICANS COLONIZATION AND NON-CANDIDA ALBICANS CANDIDA COLONIZATION AMONG UNIVERSITY STUDENTS, YEMEN PREVALENCE AND ASSOCIATED FACTORS OF ORAL NON-CANDIDA ALBICANS CANDIDA CARRIAGE IN DENTURE WEARERS IN SANA'A CITY- YEME

A lack of a definite correlation between male sub-fertility and single nucleotide polymorphisms in sperm mitochondrial genes MT-CO3, MT-ATP6 and MT-ATP8

Background An inability of a man to conceive a potentially fertile woman after a year of unprotected intercourse is defned as male infertility. It is reported that 30–40% of males in their reproductive years have abnormalities in sperm production, either qualitatively or quantitatively, or both. However, genetic factors result in up to 15% of male infertility cases. The present study aimed to analyze the possible correlations between sub-fertility and polymorphisms in sperm mitochondrial CO3, ATP6 and ATP8 genes in sub-fertile men. Methods and results For 67 sub-fertile and 44 fertile male samples, Sanger sequencing of selected mitochondrial DNA genes was done. A total of twelve SNPs in the MT-CO3 gene: rs2248727, rs7520428, rs3134801, rs9743, rs28358272, rs2853824, rs2856985, rs2854139, rs41347846, rs28380140, rs3902407, and 28,411,821, fourteen SNPs in the MT-ATP6: rs2001031, rs2000975, rs2298011, rs7520428, rs9645429, rs112660509, rs6650105, rs6594033, rs6594034, rs6594035, rs3020563, rs28358887, rs2096044, and rs9283154, and ten SNPs in the MT-ATP8: rs9285835, rs9285836, rs9283154, rs8179289, rs121434446, rs1116906, rs2153588, rs1116905, rs1116907, and rs3020563 were detected in the case and control groups at diferent nucleotide positions. Only the rs7520428 in the MT-CO3 and MT-ATP6 showed a statistically signifcant diference between sub-fertile and fertile groups in the genotype’s and allele’s frequency test (P<0.0001 for both). Conclusion The results of our study suggest that male sub-fertility is linked with rs7520428 SNP in MT-CO3 and MT-ATP6. The studied polymorphic variations in the MT-ATP8 gene, on the contrary, did not reveal any signifcant association with male sub-fertility

THE ROLE OF THE GEOPOLITICAL POSITION OF THE HASHEMITE KINGDOM OF JORDAN TOWARDS AMERICAN FOREIGN POLICY FROM 1990 TO 2017

The role of the geopolitical location of the Hashemite Kingdom of Jordan towards United States (US) foreign policy from 1990 to 2017 is the focus of this study, which addressed the impact of important regional and international political events, positively or negatively, on the development of relations between the two countries in terms of political and security aspects. The study adopted a qualitative approach, and primary data was collected through interviews with 16 participants from political, economic, and security experts in Jordan and the US. Thematic analysis was used to analyze the data obtained. The study concluded that US foreign policy recognizes Jordan as a close ally and considers its stability extremely important; Jordan has a suitable location to defend Israel because critical Arab countries surround it, and Jordan enjoys a unique geographical location in the Middle East. Some political events play an essential role in US foreign policy concerning security aid to Jordan, as the US links its aid to Jordan to political events.