Metallic Copper as Dehalogenation Catalyst in the Treatment of Water and Wastewaters

Most halogenated organic compounds (HOCs) are toxic and carcinogenic, hence unwanted in the environment. Several technologies exist for the treatment of both legacy and newly contaminated zones. In many contaminated subsurface environments, nano zero-valent iron (nZVI) as a reagent is the tool of choice, while palladium (Pd) as a catalyst faces technical challenges. A system comprising metallic copper and borohydride as a reducing agent (referred herein as copper-borohydride system, CBHS) provides an alternative to nZVI and Pd. This chapter presents a deeper understanding of the CBHS for the treatment of HOCs by highlighting the state of knowledge related to the i) type and classes of compounds that are treatable, ii) possible reaction pathways for their transformation, iii) specific metal activities for transformation of selected classes of HOCs, iv) influence of common water constituents on catalyst stability, and v) future perspectives regarding its application in water treatment applications. Furthermore, an up-to-date discussion is presented regarding the available techniques for the synthesis of copper nanoparticles. Based on the evaluation criteria including product selectivity patterns, amount and the fate of intermediates, and metal cost and stabilities in water, the most suitable application areas for Cu, Pd, and nZVI are presented as recommendations

Methylene Blue Adsorption onto Coconut husks/Polylactide Blended Films: Equilibrium and Kinetic Studies

The removal of cationic methylene blue (MB) from aqueous solutions by coconut husks/polylactide blended films was studied in a batch system. Experiments were modeled as a function of contact time, initial dye concentration, ionic strength, adsorbent dose, temperature and initial solution pH. Equilibrium data fitted the Langmuir isotherm model (R2>0.9866) with monolayer adsorption capacity qm = 16.34mg/g at 296K. Adsorption kinetics followed the pseudo-second model (R2>0.9997) hence chemisorption rate limiting step was dominant. The results have shown viability of coconut husks/polylactide blended films for the removal of recalcitrant MB from both domestic and industrial wastewaters. Key words: coconut husks, polylactide, methylene blue, isotherm, kinetic

Students' experiential motives and intention to play online games

This study aims to examine the linkages between students' multi-dimensional experiential motives and intention to use online games. The study uses convenience sampling technique for sample selection of 210 respondents. Their participation was purely voluntary. Social affiliation was found as the most influential factor in the objective to play online games among students. However, enjoyment insignificantly related with the purpose to play online games. This research contributes significantly to the online gaming industry, and marketers in boosting their profit within undergraduate by know which aspect they look into when having an intention on online gaming. The proposed framework can be the basis for further research to investigate again the intention to play online games

A critical review on polyvinylidene fluoride (PVDF)/zinc oxide (ZnO) based piezoelectric and triboelectric nanogenerators

In the recent era of energy crisis, piezoelectric and triboelectric effects are surfacing out of several research topics. Polyvinylidene fluoride (PVDF) and its copolymers are well known piezoelectric polymers due to their high piezoelectricity and widely used in flexible devices. PVDF is greatly utilized in preparation of triboelectric layer also due to its higher electronegative nature amongst common polymers. On the other hand, zinc oxide (ZnO) has been studied widely to investigate its multifunctional properties including piezoelectricity, pyroelectricity and antibacterial activity. This versatile material can be prepared, using low cost and environmental friendly routes, in various morphologies. Various research is already performed to capture the synergistic effect of reinforcing ZnO within PVDF polymeric matrix. This work firstly describes the basic principles of piezoelectric and triboelectric effects. Thereafter, piezoelectric and triboelectric performances of PVDF and ZnO based materials are briefly depicted based on their structures. Finally, challenges and future scopes, associated with the mechanical energy harvesting from such materials, are highlighted

Emirati Engagement Within an Emiratised Organizational Context: A Public Sector Analysis

This research paper aims to identify the factors tha possibly augment the placement and retention of UAE nationals in Dubai's workplaces and proposes policies for greater job opportunitie

Renoprotective effect of highdose N-Acetylcysteine in patients who underwent cardiac surgery: an observational study

Background: The effect of N-acetylcysteine (NAC) on the prevention of acute kidney injury postcardiac surgery remains controversial. This study was designed to evaluate the effect of highdose NAC on the renal function of patients who underwent cardiac surgery. Materials and Methods: A comparative cross-sectional study involving retrospective record review. One hundred and twenty-three adult patients who underwent cardiac surgery with cardiopulmonary bypass (CPB) were recruited. The study group (n = 40) received NAC 600 mg tablets a day prior to surgery and intravenous NAC 10 g into the CPB machine, and the control group (n = 83) did not receive any supplemental NAC. We evaluated the mean serum creatinine level at 24 and 48 h postoperatively and compared the prevalence of acute kidney injury using Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Results: There was no significant difference between serum creatinine and estimated glomerular filtration rate (eGFR) across the preoperation, 24, and 48 h postoperatively between the NAC and control groups (P > 0.05). There was no significant difference in the prevalence of acute kidney injury between the two groups (58 [47.2%] vs. 37 [44.6%]; P = 0.41). No difference was observed in the two groups’ need for renal replacement therapy, duration of ventilation, length of stay in the intensive care unit, and duration of hospitalization (P > 0.05). Conclusion: In this study, we did not detect statistically significant protection of renal function in patients who received NAC for cardiac surgery. A further randomized controlled trial in this area is needed to minimize confounding factors

Ultralong wavelength operation of a tunable multiwavelength Brillouin-Raman fiber laser in 1.65 μm band

A tunable multiwavelength Brillouin-Raman fiber laser (MW-BRFL) operated at an ultralong wavelength band (U-band) is presented in this work. The MW-BRFL was configured in a full-open linear cavity consisting of 11.2 km long dispersion compensating fiber that functioned as a Brillouin frequency shifter and Raman amplification gain medium. At Raman and Brillouin pump powers of 930 mW and 11.8 dBm, respectively, a stable multiwavelength generation with wavelength spacing of 0.17 nm was generated over a wavelength span of 53 nm. The generated channels covered a spectral range of 1630–1683 nm corresponding to 314 channels. The channels could also be tuned over 10 nm with an average optical signal-to-noise ratio greater than 26 dB. The laser system exhibited power fluctuation of less than 0.25 dB over 3 h. In a nutshell, the proposed MW-BRFL is promising with respect to its performance, simplicity and flexibility

A critical review on polyvinylidene fluoride (PVDF)/zinc oxide (ZnO)-based piezoelectric and triboelectric nanogenerators

In this current energy crisis era, piezoelectric and triboelectric effects are emerging as promising technologies for energy harvesting. Polyvinylidene fluoride (PVDF) and its copolymers are well-known piezoelectric materials with high piezoelectric coefficients, which are widely used in flexible electronic devices. PVDF is also greatly utilized in the preparation of triboelectric layer due to its higher electronegative nature amongst common polymers. On the other hand, zinc oxide (ZnO) has been widely studied to investigate its multifunctional properties, including piezoelectricity, pyroelectricity and antibacterial activity. This versatile material can be prepared, using low cost and environmentally friendly routes, in various morphologies. Various research has already been performed to capture the synergistic effects of reinforcing ZnO within the PVDF polymeric matrix. This work first describes the basic principles of piezoelectric and triboelectric effects. Thereafter, the piezoelectric and triboelectric performances of PVDF and ZnO-based materials are briefly depicted based on their structures. Finally, the challenges and future scope associated with the mechanical energy harvesting from such materials are highlighted

Biodegradable based TENGs for self-sustaining implantable medical devices

Biodegradable Triboelectric Nanogenerators (B-TENGs) have emerged as a groundbreaking technology with the potential to revolutionize healthcare, particularly in the field of self-powered implanted medical devices. This review explains the fundamental role of B-TENGs in addressing the critical need for sustainable energy sources to power implantable devices. Beginning with an exploration of the significance of implantable devices in healthcare, the review emphasizes the necessity for biodegradable and sustainable energy solutions. Through an in-depth examination of the principles of TENGs and their integration with both traditional and biodegradable materials, the review highlights the design considerations essential for B-TENGs development. The review discusses the diverse array of biodegradable materials employed in various layers of B-TENGs, including active layers, electrodes, and associated signal conditioning circuits. Through critical evaluation of their potential performance in enabling self-sustaining medical devices, the review explains the promising outlook for healthcare advancement through these innovative technologies. Moreover, the review critically assesses the lifespan of B-TENG materials and addresses concerns regarding device durability. By identifying challenges in the practical implementation and commercialization of B-TENGs, offers insights into overcoming barriers to widespread adoption, thereby facilitating their integration into mainstream healthcare practices. Despite significant progress, the review acknowledges current challenges facing B-TENGs as implantable medical devices and provides perspectives on potential solutions. Finally, this review paper underscores the transformative potential of B-TENGs in advancing healthcare, predicting a future where self-powered and sustainable implanted medical devices could greatly impact patient care while reducing reliance on conventional power sources.</p