23 research outputs found

    Optimization of HNO3 leaching of copper from old AMD Athlon processors using response surface methodology

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    The present study investigates the optimization of HNO leaching of Cu from old AMD Athlon processors under the effect of nitric acid concentration (%), temperature (°C) and ultrasonic power (W). The optimization study is carried out using response surface methodology with central composite rotatable design (CCRD). The ANOVA study concludes that the second degree polynomial model is fitted well to the fifteen experimental runs based on p-value (0.003), R (0.97) and Adj-R (0.914). The study shows that the temperature is the most significant process variable to the leaching concentration of Cu followed by nitric acid concentration. However, ultrasound power shows no significant impact on the leaching concentration. The optimum conditions were found to be 20% nitric acid concentration, 48.89 °C temperature and 5.52 W ultrasound power for attaining maximum concentration of 97.916 mg/l for Cu leaching in solution

    The Development of Employees’ Knowledge Sharing Behavior through Team Innovation Climate and Organization Culture

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    The purpose of this research is to provide empirical evidence concerning the impact of team innovation climate on knowledge sharing behavior and individuals’ altruistic intentions in software sector. A survey base study was conducted. Survey based-data was collected from 319 employees at software center in Pakistan. The results of this study revealed that all the constructs of team innovation climate had positive impact on altruistic intention and knowledge sharing behavior. Moreover, altruistic intention and organization culture had positive impact on knowledge sharing behavior. However, it was found that one construct of team innovation climate (Participative safety) did not have impact on organization culture. The present research contributes to the literature pertaining to the psychosocial sides of knowledge sharing behaviors. Keywords: Team innovation climate, altruistic intention, organization culture, knowledge sharing behavior

    Hydrophobicity — A Green Technique for Enhancing Corrosion Resistance of Alloys

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    The corrosion phenomenon is as old as the age of the planet. The cost of corrosion has risen alarmingly with industrial progress and it is estimated to be around 300 billion dollars or 3 to 4.5% of the GNP of developed nations. Thousands of alloys have been developed to control corrosion, which is a major consideration in the development of new ferrous and non-ferrous alloys. Several corrosion control techniques such as inhibitor treatment, coatings, cathodic protection, alloying additions, and designing for corrosion protection have been developed to combat corrosion. Despite their merits, techniques such as inhibition treatment and coatings are limited by their adverse effect on the environment because of their volatile organic components. Due to an increasingly alarming carbon footprint, there is a growing global concern to keep the environment clean. Hence, a great need exists to replace the current control methods by eco-friendly methods. The potential of the green technology of hydrophobicity has therefore been exploited to control corrosion by fabricating hydrophobic surfaces on alloys and these surfaces have shown highly promising results. This technology offers a novel method to control corrosion of metals, alloys, polymers and composites

    Mechanism of Corrosion and Erosion Resistance of Plasma‐ Sprayed Nanostructured Coatings

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    There has been a dramatic increase in recent years in a demand for tough, wear‐resistant, abrasion, erosion, and corrosion‐resistant coatings for petroleum, chemical, aerospace industry, and processes encountering harsh environments such as paper and pulp equipment (the ball valve for high‐pressure leaching). Whereas sufficient information on mechanical properties, such as abrasion, wear, and fatigue, has been gathered over the years, work on the resistance of these coatings to erosion and corrosion is seriously lacking. In the work reported, it has been shown that nanostructured TiO2 coatings offer superior physical and mechanical properties compared to conventional TiO2 coatings. Three different types of plasma‐sprayed titanium dioxide coated samples on mild steel substrate were employed for investigation. The feedstocks used were Sulzer Metco nanopowders designated as AE 9340, AE 9342, and AE 9309. Powder 9340 was a precursor. The corrosion resistance of nanostructured TiO2 coating was dictated largely by surface structure and morphology. The distribution and geometry of splat lamellae, contents of unmelted nanoparticles, and magnitude of porosity are the important factors that affect corrosion resistance. TiO2 showed excellent resistance to corrosion in 3% NaCl. The maximum corrosion rate was observed to be 4 mils per year as shown by polarization potential and weight loss studies. The erosion‐corrosion resistance of the plasma‐sprayed nanostructured titanium dioxide coatings depends largely upon the characteristics of feed powder and its reconstitution. Dense, uniform, and evenly dispersed nanostructured constituents provide a high coating integrity, which offers high resistance to erosion‐corrosion. A mechanism of erosion‐corrosion is explained in the chapter with a schematic diagram. The findings show that the nanostructured TiO2 coatings offer superior resistance to corrosion, erosion, and environmental degradation

    Disease Pattern and Outcome among Neonates in Pediatric Ward of POF Hospital, Wah

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    Background: Neonatal period is the duration between 0-28 days of birth and it is the most susceptible period of life because of the large number of problems and diseases which a neonate is likely to face. The objective of the study was to determine the disease pattern and outcome among neonates in Pediatric ward of POF Hospital.Material and Methods: A descriptive study was carried out at Pediatric ward of POF Hospital Wah Cantt. Retrospective data regarding age, sex, reasons for admission, outcome and mode of delivery (from hospital record) was collected for all neonates admitted during the year 2016 from 1st January to 31st December. The data was analyzed by using SPSS V-19.Results: Among total neonates (n=887) admitted during the year, 63.2% were males and 36.8% were females. Mean weight of neonates was 2.54 + 0.75 kg while mean age was 2.39 + 5.8 days. Most common diseases were Prematurity, Respiratory Distress Syndrome, Seizures and Sepsis. Overall, 82.64% recovered from their illness while 17.02% expired.Conclusions: Prematurity, respiratory distress syndrome, seizures and sepsis were the major causes of neonatal admission in this study.Key words: Diagnostic value, Immature-to-total neutrophil ratio, Neonatal sepsi

    Low-Cost Single Chamber MFC Integrated With Novel Lignin-Based Carbon Fiber Felt Bioanode for Treatment of Recalcitrant Azo Dye

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    A flow through anaerobic microbial fuel cell (MFC) was designed and optimized for efficient treatment of recalcitrant textile wastewater. The membrane-less MFC was first time fabricated with a unique combination of electrodes, a novel bioanode of synthesized lignin-based electrospun carbon fiber supporting a biofilm of Geobacter sulfurreducens for acetate oxidation and an air-breathing cathode, consisting of a pyrolyzed macrocycle catalyst mixture on carbon bonded by polytetrafluoroethylene (PTFE). The effects of different organic loadings of acetate along with Acid Orange (AO5), operation time and ionic strength of auxiliary salts (conductivity enhancers) were investigated and responses in terms of polarization and degradation were studied. In addition, the decomposition of the organic species and the degradation of AO5 along with its metabolites and degraded products (2-aminobenzenesulfonic acid) were determined by chemical oxygen demand (COD) analysis, UV-Vis spectrophotometry and high-performance liquid chromatography (UV-HPLC) techniques. SEM and TEM images were also used to find out the biocompatibility of the microbes on lignin-based electrospun carbon felt anode and the morphology of the cathode. Reduction and breakage of the azo bond of AO5 occurs presumably as a side reaction, resulting in the formation of 2-aminobenzenesulfonic acid and unidentified aromatic amines. Maximum current density of anode 0.59 Am−2 and power density of 0.12 Wm−2 were obtained under optimized conditions. As a result, decolouration of AO5 and chemical oxygen demand (COD) removal efficiency was 81 and 58%, respectively. These results revealed that the low-cost MFC assembly can offer significant potential for anaerobic decolouration of recalcitrant textile wastewater

    NO and SO2 emissions in palm kernel shell catalytic steam gasification with in-situ CO2 adsorption for hydrogen production in a pilot-scale fluidized bed gasification system

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    The NO and SO2 emissions in enhanced hydrogen production from palm kernel shell (PKS) steam gasification with integrated catalytic adsorption steam gasification is investigated. The influence of steam and adsorbent to biomass ratios (1.5–2.5, 1.0–1.5), temperature (600–750 °C), biomass particle size (0.355–2.0 mm) and fluidization velocity (0.15–26 m/s) was reported. The results inferred that lower temperature (600 °C) contributed to emissions of NO (30 ppm) and SO2 (110 ppm) whereas high steam to biomass ratio (2.5 wt/wt) produced emissions of <30 ppm and <110 ppm, respectively, at experimental conditions of 675 °C, adsorbent to biomass ratio of 1.0 (wt/wt) and catalyst to biomass ratio of 0.1 (wt/wt). The lowest average minimum NO and SO2 concentration of 16 ppm and 46 ppm, respectively, was observed at 675 °C, steam to biomass ratio of 2.0 (wt/wt), adsorbent to biomass ratio of 1.5 (wt/wt) and catalyst to biomass ratio of 0.1(wt/wt). Nevertheless, emissions were prorportional to fluidization velocities and small particle size (0.3–0.5 mm) contributed to high NO and SO2. The comparative studies found that the present study produced similar emission of NO (30 ppm) when compared with commercial indirect heated fluidized bed gasifier using steam as an oxidizing agent. Besides, some other studies operated at high temperature reported high NO and SO2 concentration which might be due to the temperature being the most influential variable in the context

    Biological Wastewater Treatment and Resource Recovery

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    Biological treatment of wastewater is a low-cost solution for remediation of wastewater. This book focuses on the bioremediation of wastewater, its management, monitoring, role of biofilms on wastewater treatment and energy recovery. It emphasizes on organic, inorganic and micropollutants entering into the environment after conventional wastewater treatment facilities of industrial, agricultural and domestic wastewaters. The occurrence of persistent pollutants poses deleterious effects on human and environmental health. Simple solution for recovery of energy as well as water during biological treatment of wastewater is a viable option. This book provides necessary knowledge and experimental studies on emerging bioremediation processes for reducing water, air and soil pollution
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