Nanocatalysts for the electrochemical reduction of carbon dioxide to fuels

This thesis focuses on the synthesis of nanocatalysts for the electroreduction of CO¬2 to useful fuels such as formic acid, methanol, methane and carbon monoxide. Copper-based materials were synthesised via a continuous hydrothermal flow synthesis process (CHFS). This method involved mixing pressurised precursor solutions with supercritical water to rapidly form ultra-fine nanocatalysts. CuO synthesis was investigated by varying experimental parameters, such as mixer types, temperature, pH, metal salt precursor and H¬2O¬2. Particle size was modulated by controlling these parameters and sub-15 nm particle sizes were possible. This has not been previously observed or reported in the literature in flow synthesis for CuO. The as-prepared CuO nanoparticles were formulated into Nafion based inks. The influence of the Nafion fraction on the Faradaic efficiencies and overpotential was explored. The highest Faradaic efficiency for formic acid production (61%) was observed with the optimum Nafion fraction. Insights into the significant increase in the Faradaic efficiency with the optimum Nafion content was elucidated with electrochemical impedance spectroscopy (EIS). Ni doped CuO synthesised via CHFS, was reported here for the first time, where higher inclusion of Ni was possible compared to co-precipitation. The Ni doped CuO samples were evaluated for their electrocatalytic properties and showed higher Faradaic efficiency at lower overpotential (<1.2 V) and below 11 at % Ni, compared to the undoped CuO. The catalysts were evaluated by EIS, Tafel analysis and structural characterisation. Rotating Ring Disk Electrode (RRDE), a hydrodynamic technique, was validated as a high-throughput tool to screen catalysts prior to bulk electrolysis. The Pt ring was successfully used to electrochemically detect formic acid, as it was formed in situ on copper-based catalysts. This was confirmed by conducting product calibration and understanding the oxidation behaviour on Pt as a function of rotation and scan rate

Resource allocation for D2D links in the FFR and SFR aided cellular downlink

Device-to-device (D2D) communication underlying cellular networks, allows direct transmission between two devices in each other's proximity that reuse the cellular resource blocks in an effort to increase the network capacity and spectrum efficiency. However, this imposes severe interference that degrades the system's performance. This problem may be circumvented by incorporating fractional frequency reuse (FFR) or soft frequency reuse (SFR) in OFDMA cellular networks. By carefully considering the downlink resource reuse of the D2D links, we propose beneficial frequency allocation schemes, when the macrocell has employed FFR or SFR as its frequency reuse technique. The performance of these schemes is quantified using both the analytical and simulation results for characterizing both the coverage probability and the capacity of D2D links under the proposed schemes that are benchmarked against the radical unity frequency reuse scheme. The impact of the D2D links on the coverage probability of macrocellular users (CUs) is also quantified, revealing that the CUs performance is only modestly affected under the proposed frequency allocation schemes. Finally, we provide insights concerning the power control design in order to strike a beneficial tradeoff between the energy consumption and the performance of D2D lin

Cataract and its risk factor among adults residing in South Bihar, India

Background: Cataract is considered as one of the most common causes of visual impairment and the leading cause of blindness in the world. Age related cataract occurs in people above 50 years of age and the its pathogenesis is multifactorial. Therefore, the present study was aimed to assess the prevalence and risk factors for cataract.Methods: Community based cross sectional study was conducted among adults residing at urban areas of South Bihar. The data was collected by interview method, using pre-tested semi-structured questionnaire which contains socio-demographic data, dietary habits, history of diabetes or hypertension, family history of cataract and long-term sun exposure.Results: Among 240 participants, 94 (39.2%) were male and 146 (60.8%) were female. Maximum participants were aged more than 70 years. The prevalence of cataract was 52.1%.Conclusions: The prevalence of cataract was quite high and was significantly associated with age, long term sun exposure and family history of cataract

Combined EXAFS, XRD, DRIFTS, and DFT Study of Nano Copper-Based Catalysts for CO2 Hydrogenation

Highly monodispersed CuO nanoparticles (NPs) were synthesized via continuous hydrothermal flow synthesis (CHFS) and then tested as catalysts for CO2 hydrogenation. The catalytic behavior of unsupported 11 nm sized nanoparticles from the same batch was characterized by diffuse reflectance infrared fourier transform spectroscopy (DRIFTS), extended X-ray absorption fine structure (EXAFS), X-ray diffraction (XRD), and catalytic testing, under CO2/H2 in the temperature range 25–500 °C in consistent experimental conditions. This was done to highlight the relationship among structural evolution, surface products, and reaction yields; the experimental results were compared with modeling predictions based on density functional theory (DFT) simulations of the CuO system. In situ DRIFTS revealed the formation of surface formate species at temperatures as low as 70 °C. DFT calculations of CO2 hydrogenation on the CuO surface suggested that hydrogenation reduced the CuO surface to Cu2O, which facilitated the formation of formate. In situ EXAFS supported a strong correlation between the Cu2O phase fraction and the formate peak intensity, with the maxima corresponding to where Cu2O was the only detectable phase at 170 °C, before the onset of reduction to Cu at 190 °C. The concurrent phase and crystallite size evolution were monitored by in situ XRD, which suggested that the CuO NPs were stable in size before the onset of reduction, with smaller Cu2O crystallites being observed from 130 °C. Further reduction to Cu from 190 °C was followed by a rapid decrease of surface formate and the detection of adsorbed CO from 250 °C; these results are in agreement with heterogeneous catalytic tests where surface CO was observed over the same temperature range. Furthermore, CH4 was detected in correspondence with the decomposition of formate and formation of the Cu phase, with a maximum conversion rate of 2.8% measured at 470 °C (on completely reduced copper), supporting the indication of independent reaction pathways for the conversion of CO2 to CH4 and CO that was suggested by catalytic tests. The resulting Cu NPs had a final crystallite size of ca. 44 nm at 500 °C and retained a significantly active surface

Comparison on efficiency of various techniques in treatment of waste and sewage water – A comprehensive review

AbstractIn the present scenario, environmental laws have become stringent towards health, economy and reduction of pollution. The pollution is a result of discharge of various organic and inorganic substances into the environment. The sources of pollution include domestic agricultural and industrial water. Conventional techniques such as chemical precipitation, carbon adsorption, ion exchange, evaporations and membrane processes are found to be effective in treatment of waste and sewage water. Recently, biological treatments have gained popularity to remove toxic and other harmful substances. The objective of the paper is to make comprehensive review including the performance of each technique in treatment of waste and sewage water. The research directions are also suggested based on the review

Sex and age differences and outcomes in acute coronary syndromes

Background: There is conflicting information about sex differences in presentation, treatment, and outcome after acute coronary syndromes (ACS) in the era of reperfusion therapy and percutaneous coronary intervention. The aim of this study was to examine presentation, acute therapy, and outcomes of men and women with ACS with special emphasis on their relationship with younger age ( lt = 65 years). Methods: From January 2010 to June 2015, we enrolled 5140 patients from 3 primary PCI capable hospitals. Patients were registered according to the International Survey of Acute Coronary Syndrome in Transitional Countries (ISACS-TC) registry protocol (ClinicalTrials.gov: NCT01218776). The primary outcome was the incidence of in-hospital mortality. Results: The study population was constituted by 2876 patients younger than 65 years and 2294 patients older. Women were older than men in both the young (56.2 +/- 6.6 vs. 54.1 +/- 7.4) and old (74.9 +/- 6.4 vs. 73.6 +/- 6.0) age groups. There were 3421 (66.2%) patients with ST elevation ACS (STE-ACS) and 1719 (33.8%) patients without ST elevation ACS (NSTE-ACS). In STE-ACS, the percentage of patients who failed to receive reperfusion was higher in women than in men either in the young (21.7% vs. 15.8%) than in the elderly (35.2% vs. 29.6%). There was a significant higher mortality in women in the younger age group (age-adjusted OR 1.52, 95% CI: 1.01-2.29), but there was no sex difference in the older group (age-adjusted OR 1.10, 95% CI: 0.87-1.41). Significantly sex differences in mortality were not seen in NSTE-ACS patients. Conclusions: In-hospital mortality from ACS is not different between older men and women. A higher short-term mortality can be seen only in women with STEMI and age of 65 or less

Metabolic Syndrome and Benign Prostatic Hyperplasia: Evidence of a Potential Relationship, Hypothesized Etiology, and Prevention

Benign prostatic hyperplasia (BPH) is highly prevalent in older men and causes substantial adverse effects on health. The pathogenesis of this disease is not totally clear. Recent reports have suggested a possible relationship between metabolic syndrome (MetS) and BPH. Single components of MetS (obesity, dyslipidemia, hypertension, and insulin resistance) as well as the syndrome itself may predispose patients to a higher risk of BPH and lower urinary tract symptoms (LUTS). This may stem from changes in insulin resistance, increased autonomic activity, impaired nitrergic innervation, increased Rho kinase activity, pro-inflammatory status, and changes in sex hormones that occur in association with MetS. However, the exact underlying mechanisms that regulate the potential relationship between MetS and BPH/LUTS still need to be clarified. Increased physical activity and dietary strategies may help in decreasing the incidence of MetS and its impact on BPH/LUTS. However, differences in the definitions used to address the examined predictors and endpoints preclude the possibility of arriving at definitive conclusions

Type 2 Diabetes Modifies the association of Cad Genomic Risk Variants With Subclinical atherosclerosis

BACKGROUND: Individuals with type 2 diabetes (T2D) have an increased risk of coronary artery disease (CAD), but questions remain about the underlying pathology. Identifying which CAD loci are modified by T2D in the development of subclinical atherosclerosis (coronary artery calcification [CAC], carotid intima-media thickness, or carotid plaque) may improve our understanding of the mechanisms leading to the increased CAD in T2D. METHODS: We compared the common and rare variant associations of known CAD loci from the literature on CAC, carotid intima-media thickness, and carotid plaque in up to 29 670 participants, including up to 24 157 normoglycemic controls and 5513 T2D cases leveraging whole-genome sequencing data from the Trans-Omics for Precision Medicine program. We included first-order T2D interaction terms in each model to determine whether CAD loci were modified by T2D. The genetic main and interaction effects were assessed using a joint test to determine whether a CAD variant, or gene-based rare variant set, was associated with the respective subclinical atherosclerosis measures and then further determined whether these loci had a significant interaction test. RESULTS: Using a Bonferroni-corrected significance threshold of CONCLUSIONS: These results highlight T2D as an important modifier of rare variant associations in CAD loci with CAC

Development and Validation of Palliative Care Bundle for Advanced Gallbladder Cancer “PALLICR”

Abstract Kusum K. Rohilla Background The aim of this study was to develop and validate a comprehensive palliative care bundle “PALLICR” for advanced gallbladder cancer (GBC) patients. Materials and Methods The present study was an exploratory study with instrument validation design which was conducted at All India Institute of Medical Sciences, Rishikesh, India. A total of 25 advance cancer patients were selected using the purposive sampling technique. Results The newly developed PALLICR bundle consists of six items under three subfactors, that is, functional recovery, resilience, and quality of life. The final version of bundle with six items of PALLICR bundle was validated and showed a good fit to provide palliative care to advanced GBC patients. Standardized scales, that is, palliative care outcome scale, European Organization for Research and Treatment of Cancer quality-of-life scale for patients and caregiver strain index for caregivers were used for evaluation of PALLICR bundle effectiveness. Conclusion PALLICR bundle is valid and reliable methods to provide palliative care to advanced GBC patients