From PET Bottles Waste to N-Doped Graphene as Sustainable Electrocatalyst Support for Direct Liquid Fuel Cells

Direct liquid fuel cells represent one of the most rapidly emerging energy conversion devices. The main challenge in developing fuel cell devices is finding low-cost and highly active catalysts. In this work, PET bottle waste was transformed into nitrogen-doped graphene (NG) as valuable catalyst support. NG was prepared by a one-pot thermal decomposition process of mineral water waste bottles with urea at 800 °C. Then, NG/Pt electrocatalysts with Pt loadings as low as 0.9 wt.% and 1.8 wt.% were prepared via a simple reduction method in aqueous solution at room temperature. The physical and electrochemical properties of the NG/Pt electrocatalysts are characterized and evaluated for application in direct borohydride peroxide fuel cells (DBPFCs). The results show that NG/Pt catalysts display catalytic activity for borohydride oxidation reaction, particularly the NG/Pt_1, with a number of exchanged electrons of 2.7. Using NG/Pt composite in fuel cells is anticipated to lower prices and boost the usage of electrochemical energy devices. A DBPFC fuel cell using NG/Pt_1 catalyst (1.8 wt.% Pt) in the anode achieved a power density of 75 mW cm−2 at 45 °C. The exceptional performance and economic viability become even more evident when expressed as mass-specific power density, reaching a value as high as 15.8 W mgPt−1

TRUST IN CROSS-CULTURAL B2B FINANCIAL SERVICE RELATIONSHIPS: THE ROLE OF SHARED VALUES

This is the accepted version of the following article: Houjeir, R. & Brennan, R. J, 'Trust in cross-cultural b2b financial service relationships: The role of shared values', Journal of Financial Services Marketing, June 2016, Vol 21(2): 90-102 The final publication is available at Springer via http://dx.doi.org/10.1057/fsm.2016.4Trust in business-to-business supplier–customer relationships in financial services is an area of considerable research interest. The bulk of prior empirical research in this field has concentrated on trust in business relationships within a Western cultural context. However, shared values are acknowledged to be an important antecedent to trust. The premise of this study is that in circumstances where there are substantial cultural differences between parties to a supplier–customer relationship, these differences will be reflected in shared values, which will in turn be reflected in differences in the nature of trust. A qualitative study was conducted among business bankers and their corporate clients in the context of the United Arab Emirates. In all 170 respondents were interviewed; of these, 160 were paired respondents, that is, where a client and banker from the same business relationship were interviewed (yielding 80 interview dyads). Substantial differences with respect to trust were found between relationships that involved only Emiratis, those that involved Emiratis and non-Emiratis, and those that involved only non-Emiratis. For Emiratis mutual trust is substantially based on family and clan ties and exhibits strongly affective characteristics. For non-Emiratis trust is largely based on business considerations, and exhibits strongly cognitive characteristics.Peer reviewedFinal Accepted Versio

The effect of adding long acting beta 2 agonists to inhaled corticosteroids versus increasing dose of inhaled corticosteroids in improving asthma control

To asthmatic patients with moderate to severe persistent asthma, two main treatment options are recommended: The combination of a long-acting inhaled β2-agonist with inhaled corticosteroids or the use of a higher dose of inhaled corticosteroids. The aim of this study was to evaluate which drug option is more favorable. Patients and methods: This study included 60 asthmatic patients uncontrolled on low doses of ICSs. They were randomized into two groups. Group (1): 30 patients received twice daily inhaled formetrol and budesonide in a dose of 12 mcg and 400 mcg, respectively. Group (2): 30 patients received two fold the previous dose of budesonide 800 mcg/BID alone. A comparative study was carried out at Outpatient Chest Clinic of Fayoum Hospital University for a period of 24 weeks using the spirometric data of patients of the two groups before and after treatment. Results: Results showed that the combination therapy of inhaled formetrol and budesonide is modestly more effective in the reduction of symptoms and in improving the lung functions than with a higher dose of budesonide alone. Conclusion: Adding formetrol in a dose of 12 μg plus budesonide in a dose 400 μg b.i.d. is more favorable in treatment of asthma than a higher dose of budesonide (800 μg b.i.d)

Diagnostic value of adenosine deaminase in tuberculous and malignant pleural effusion

Introduction: Tuberculous pleural effusion (TPE) is a common problem for differential diagnosis from malignant effusion (MPE) in epidemic areas of tuberculosis (TB). Prediction based on adenosine deaminase (ADA) is dependent on age as well as the tuberculosis incidence. Aim of the work: To estimate the value of cutoff point of ADA in MPE and TPE & to evaluate its role in differential diagnosis in Egypt a country with high incidence of TB. Subjects & methods: The study was conducted in Kaser El-Aini Hospital, Cairo University in the period from April 2011 to January 2012. It was carried on 30 patients. We retrospectively analyzed 30 patients with a definitive diagnosis of TPE (n = 19) and MPE (n = 11). The optimal cutoff value of ADA was determined using the receiver operating characteristic (ROC) curve. There was a statistically significant difference according to the levels of pleural fluid ADA between TPE and MPE groups. Result: Confirm that ADA is a very useful parameter for the differential diagnosis of TPE and MPE, specifically in younger with a higher incidence of tuberculosis

Clinical utility of interferon-γ compared to ADA in tuberculous pleural effusion

Introduction: Tuberculosis (TB), the single most frequent infectious cause of death worldwide, also is a major cause of pleural effusion, which in TB usually has lymphocytic and exudative characteristics. Differential diagnosis between TB and nontuberculous pleural effusion can be sometimes difficult, representing a critically important clinical problem. Aim of the work: To evaluate the clinical utility of pleural IFN-γ level in pleural fluid for diagnosing tuberculous pleuritis. Subject and methods: The study was conducted in kasr El-Aini hospital, Cairo University in the period from January 2011 to January 2012. It was carried on 40 patients. The patients included in the study were classified into group І (included 20 cases with tuberculous pleural effusion) and group II (included 20 cases with non tuberculous pleural effusion). All patients were subjected for complete history taking and clinical examination, chest X-rays PA and lateral views, pleural fluid aspiration and analysis. Result: Our results demonstrate that the pleural fluid concentrations of ADA, INF-γ in patients with tuberculous pleural effusions are significantly higher than in other effusions. Most importantly, ROC analysis clearly demonstrated ADA to be more sensitive and specific than INF-γ for diagnosis of tuberculous pleuritis

Effect of the Morphology of Tungsten Oxide Embedded in Sodium Alginate/Polyvinylpyrrolidone Composite Beads on the Photocatalytic Degradation of Methylene Blue Dye Solution

Tungsten oxide nanostructures were modified by oxygen vacancies through hydrothermal treatment. Both the crystalline structure and morphological appearance were completely changed. Spherical WO3·H2O was prepared from tungstic acid solution by aging at room temperature, while rod-like WO3·0.33H2O was prepared by hydrothermal treatment of tungstic acid solution at 120 °C. These structures embedded in sodium alginate (SA)/polyvinylpyrrolidone (PVP) were synthesized as novel porous beads by gelation method into calcium chloride solution. The performance of the prepared materials as photocatalysts is examined for methylene blue (MB) degradation in aqueous solutions. Different operation parameters affecting the dye degradation process, such as light intensity, illumination time, and photocatalyst dosage are investigated. Results revealed that the photocatalytic activity of novel nanocomposite changed with the change in WO3 morphology. Namely, the beads with rod nanostructure of WO3 have shown better effectiveness in MB removal than the beads containing WO3 in spherical form. The maximum degradation efficiency was found to be 98% for WO3 nanorods structure embedded beads, while the maximum removal of WO3 nanospheres structure embedded beads was 91%. The cycling-ability and reuse results recommend both prepared structures to be used as effective tools for treating MB dye-contaminated wastewaters. The results show that the novel SA/PVP/WO3 nanocomposite beads are eco-friendly nanocomposite materials that can be applied as photocatalysts for the degradation of cationic dyes in contaminated water

Polyvinyl Alcohol/Polyaniline/Carboxylated Graphene Oxide Nanocomposites for Coating Protection of Cast Iron in Simulated Seawater

In our daily lives and product manufacturing, metal corrosion causes significant economic losses. Numerous polymeric composite coatings have been shown to be resistant to harsh environments, such as those found in marine environments. In this study, a composite of polyvinyl alcohol/polyaniline blend loaded with carboxylated graphene was explored in the search for long-lasting coatings to resist electrochemical deterioration of cast iron in desalination systems of saltwater. Polyvinyl alcohol/polyaniline/carboxylated graphene oxide nanocomposite was spin-coated onto cast iron samples. Electrochemical impedance spectroscopy (EIS) and electrochemical DC corrosion testing with a three-electrode system were used to study corrosion resistance in uncoated and coated cast iron samples. The results exhibit effective corrosion protection properties. The EIS data indicated better capacitance and higher impedance values for coated samples than bare metal, depicting enhanced corrosion resistance against the saline environment. Tafel analysis confirmed a significant decrease in the corrosion rate of the PVA/PANI/GO-COOH coated sample

Novel Sodium Alginate/Polyvinylpyrrolidone/TiO2 Nanocomposite for Efficient Removal of Cationic Dye from Aqueous Solution

The combination of adsorption and photodegradation processes is an effective technique for the removal of dye contaminants from water, which is motivating the development of novel adsorbent-photocatalyst materials for wastewater treatment. Herein, novel nanocomposite porous beads were developed using titanium dioxide (TiO2) nanotubes embedded in a sodium alginate (SA)/polyvinylpyrrolidone (PVP) matrix using calcium chloride solution as a crosslinker. The prepared nanocomposite beads’ performance was examined as an adsorbent-photocatalyst for the breakdown of methylene blue in aqueous solutions. Several operation factors influencing the dye decomposition process, including photocatalyst dosage, illumination time, light intensity, and stability were investigated. The findings demonstrated that the removal activity of the beads changed with the TiO2 weight ratio in the composite. It was found that SA/PVP/TiO2-3 nanocomposite beads presented the greatest deterioration efficiency for methylene blue dye (98.9%). The cycling ability and reusability of the prepared SA/PVP/TiO2 nanocomposite beads recommend their use as efficient, eco-friendly materials for the treatment of wastewaters contaminated with cationic dyes