377 research outputs found
Electrochemical determination of Cd2+ in some Al-Madinah water samples and human plasma by cathodic stripping voltammetry in the presence of oxine as a chelating agent
AbstractA fast, simple, sensitive cathodic adsorptive stripping voltammetric procedure for quantitative analysis of Cdâoxine complex in al-Madinah city water samples and human plasma is described. The technique involves adsorptive accumulation of the complex on the working electrode, followed by square wave voltammetric determination of the preconcentrated analyte. In basic media, a cathodic electrochemical process involving the elimination of two protons occurs, and a mechanism for the reduction process is suggested. The optimal experimental parameters for assay of this complex are: carbonate supporting electrolyte pH 8, accumulation time 30s, accumulation potential â0.1V, scan rate 200mVsâ1, pulse amplitude 80mV, frequency 40Hz, surface area of working electrode 0.6mm2 and convection rate 1000rpm. The calibration graph for determination of Cdâoxine was linear over the concentration range 5Ă10â8 to 4Ă10â7mollâ1 (r=0.998), with a detection limit of 3.5Ă10â9mollâ1. The precision of the proposed procedure was estimated by 10 successive voltammetric measurements of 2Ă10â6mollâ1 Cd with 4Ă10â6mollâ1 oxine, and the calculated relative standard deviation was 0.39%. The percentage recovery, indicating the accuracy of the analytical method, was 94±1.0%. Possible interference by several substances, including metals and ligands, was also evaluated. The electroanalytical method was successfully applied to assaying cadmium in water samples and biological fluids such as plasma
Electrochemical determination of rosiglitazone by square-wave adsorptive stripping voltammetry method
AbstractSquare-wave adsorptive stripping voltammetry technique was used to determine rosiglitazone (ROS) on the hanging mercury dropping electrode (HMDE) surface, in Britton Robinson buffer, pH=5. The voltammetric cathodic peak was observed at â1520mV vs. Ag/AgCl reference electrode. The voltammetric peak response was characterized with respect to pH, supporting electrolyte, accumulation potential, preconcentration time, scan rate, frequency, pulse amplitude, surface area of the working electrode and the convection rate. Under optimal conditions, the voltammetric current is proportional to the concentration of ROS over the concentration range of 5Ă10â8â8Ă10â7mollâ1 (r=0.9899) with a detection limit of 3.2Ă10â11mollâ1 using 120s accumulation time. The developed SW-AdSV procedure showed a good reproducibility, the relative standard deviation RSD% (n=10) at a concentration level of 5Ă10â7mollâ1 was 0.33%, whereas the accuracy was 101%±1.0. The proposed method was successfully applied to assay the drug in the human urine and plasma samples with mean recoveries of 90±0.71% and 86±1.0%, respectively
General characteristics and common practices for ICT projects: Evaluation perspective
In today's business world, organizations are more dependent on Information and Communication Technologies (ICT) resources. Cloud services, communication services and software services are most common resources, enterprises are spending large amount. To install new services and upgrade existing services, ICT project are essential part of organization's business strategies. Researchers highlighted the real problem for the organization is to initiate new ICT projects and its evaluation after implementation. This research investigated the common approaches organizations using to start with ICT projects and how to evaluate its impact on after implementation. For this, we have extracted the number of steps with the help of literature review. To validate those steps, six case studies are selected for collecting the samples. The findings of this study elaborate that every ICT project has list of objectives i.e. strategic, informational, IT infrastructure and others. Furthermore, the results highlight that organizations believe on both financial and non-financial evaluation methods based on the type of organization i.e. public or private. Moreover, measurement process applied on project wise, monthly and yearly bases. Importantly, we have found that currently outsourcing plays significant role in success of ICT projects. The results of this study can be helpful for the organization to understand the type of ICT investments, approaches and possible impact on the organizations goals
Studies on wings symmetry and honey bee races discrimination by using standard and geometric morphometrics
Abstract: Morphometric is an essential tool for honey bee races discrimination and characterization. Such vital tool has been applied widely in honey bee researches. Unfortunately there is no available literature for confirming honey bee wings symmetry. Therefore, standard and geometric morphometric analyses were employed for investigating wings symmetry as well as for discriminating between Carniolan and Yemeni honey bees. Moreover, three angles of hind wings (H1, H2 and H3) were evaluated in the discrimination between the two races. Results of morphometric analyses strongly confirmed the symmetry of honey bee wings. Standard and geometric morphometric analyses successfully discriminate between the two races. Hind wing length and angle H3 could be incorporated in honey bee races discrimination
Insomnia in chronic renal patients on dialysis in Saudi Arabia
<p>Abstract</p> <p>Background</p> <p>Studies have shown that insomnia is a common sleep disorder among patients with end-stage renal disease (ESRD). This study aimed to assess the prevalence of insomnia in Saudi patients with ESRD who are on maintenance dialysis.</p> <p>Methods</p> <p>This was an observational cross-sectional study carried out over a period of five months in two hemodialysis centers in Saudi Arabia. To assess the prevalence of insomnia, we used the ICSD-2 definition. We also examined the association between insomnia and other sleep disorders, the underlying causes of renal failure, dialysis duration, dialysis shift, and other demographic data.</p> <p>Results</p> <p>Out of 227 enrolled patients, insomnia was reported by 60.8%. The mean patient age was 55.7 ± 17.2 years; 53.7% were male and 46.3% were female. Insomnia was significantly associated with female gender, afternoon hemodialysis, Restless Legs Syndrome, high risk for obstructive Sleep Apnea Syndrome and excessive daytime sleepiness (<it><b>P-values: </b></it>0.05, 0.01, < 0.0001, < 0.0001, and < 0.0001, respectively). No significant association was found between insomnia and other variables, including BMI, smoking habits, underlying etiology of renal failure, dialysis duration, association with hemoglobin, ferritin, and phosphorus or dialysis adequacy as measured by the Kt/V index.</p> <p>Conclusion</p> <p>Insomnia is common in dialysis patients and was significantly associated with other sleep disorders. Greater attention needs to be given to the care of dialysis patients with regard to the diagnosis and management of insomnia and associated sleep disorders.</p
Characteristics of the ïŹssion fragments induced by the 129Xe + natSn reactions at E = 8â15A MeV
The study of nuclear multifragmentation is important for understanding the reaction mechanisms in heavy-ion collisions. In the present work, we study the nuclear reaction 129Xe + natSn in the energy range E = 8 to 15 AMeV. This experiment was performed at GANIL with the multidetector INDRA. We study the charge distributions produced in this reaction, which are broad and cover a large atomic number range. By using the data of this experiment, we identify four channels diïŹering by the number of fragments: 1, 2, 3 and 4 fragments. In this contribution we will show a method to reconstruct the average size and excitation energy of the primary ïŹssion fragments, before their decay. The method employed is based on the fragment-light charged particles relative velocity correlation functions. Preliminary results will be presented
Controlling of crystal size and optical band gap of CdO nanopowder semiconductors by low and high Fe contents
The CdO:Fe nanopowder semiconductors were
synthesized by the solâgel calcination for the first time.
The structural properties of Fe doped CdO samples were
analyzed by AFM and XRD measurements. XRD patterns
of the pure and Fe-doped CdO samples reveal that the pure
and Fe doped CdO nanopowders are polycrystalline of cubic
CdO structure. The crystallite size of undoped and Fe-doped
CdO samples is changed unsystematically with a regular
increase of Fe content. The optical band gaps of Fe doped
CdO samples were determined for the first time by diffused
reflectance measurements. The optical band gap of the samples is increased with the increase of Fe dopant inside the
host matrix (CdO) up to 15 % followed by a decrease in its
value. It is evaluated that Fe doped CdO nanopowder semiconductors can be producted by solâgel calcination for
advanced technological application
Adsorption Sites of Hydrogen Atom on Pure and Mg-Doped Multi-Walled Carbon Nanotubes
Hydrogen adsorption sites on pure multiwalled carbon nanotube (MWCNT) and Mg-doped MWCNTs material system have been investigated using molecular dynamics (MD) simulations as well as quantum chemical calculations. Through combining MWCNTs with Mg, the hydrogen adsorption sites energy on this Mg-MWCNTs system is found to be larger than that of the pure MWCNTs. Additionally, it was found that, through Mg-doping, new adsorption sites for hydrogen molecules are created in comparison with undoped nanotubes. It is also found that H atom is preferably adsorbed at every place near magnesium atom
A novel barium oxide-based Iraqi sand glass to attenuate the low gamma-ray energies: Fabrication, mechanical, and radiation protection capacity evaluation
In the present work, untreated Iraqi sand with grain sizes varied between 100 and 200 ÎŒm was used to produce a colored glass sample that has shielding features against the low gamma-ray energy. Therefore, a weight of 70â60 wt % sand was mixed with 9â14 wt% B2O3, 8â10 wt% Na2O, 4â6 wt% of CaO, 3â6 wt% Al2O3, in addition to 0.3% of Co2O3. After melting and annealing the glass sample, the X-ray diffraction spectrometry was applied to affirm the amorphous phase of the fabricated glass samples. Moreover, the X-ray dispersive energy spectrometry was used to measure the chemical composition, and the MH-300A densimeter was applied to measure the fabricated sample's density. The Makishima-Makinzie model was applied to predict the mechanical properties of the fabricated glass. Besides, the Monte Carlo simulation was used to estimate the fabricated glass sample's radiation shielding capacity in the low-energy region between 22.1 and 160.6 keV. Therefore, the simulated linear attenuation coefficient changed between 10.725 and 0.484 cmâ1, raising the gamma-ray energy between 22.1 and 160.6 keV. Also, other shielding parameters such as a half-value layer, pure lead equivalent thickness, and buildup factors were calculated. © 2022 Korean Nuclear SocietyPrincess Nourah Bint Abdulrahman University, PNU: PNURSP2022R28The authors express their gratitude to Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2022R28), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
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