Electrochemical Behavior of Carbon Nanostructured Electrodes: Graphene, Carbon Nanotubes, and Nanocrystalline Diamond

<p>The primary goals of this research were to investigate the electrochemical behavior of carbon nanostructures of varying morphology, identify morphological characteristics that improve electrochemical capacitance for applications in energy storage and neural stimulation, and engineer and characterize a boron-­doped diamond (BDD) electrode based electrochemical system for disinfection of human liquid waste. </p><p>Carbon nanostructures; ranging from vertically aligned multiwalled carbon nanotubes (MWCNTs), graphenated carbon nanotubes (g-­CNTs) to carbon nanosheets (CNS); were synthesized using a MPECVD system. The nanostructures were characterized by using scanning electron microscopy (SEM) and Raman spectroscopy. In addition to employing commonly used electrochemical techniques such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), a new technique was developed to evaluate the energy and power density of individual electrodes. This facilitated comparison of a variety of electrode materials without having to first develop complex device packaging schemes. It was found that smaller pore size and higher density of carbon foliates on a three-dimensional scaffold of carbon nanotubes increased specific capacitance. A design of experiments (DOE) study was conducted to explore the parametric space of the MWCNT system. A range of carbon nanostructures of varying morphology were obtained. It was observed that the capacitance was dependent on defect density. Capacitance increased with defect density.</p><p>A BDD electrode was characterized for use in a module designed to disinfect human liquid waste as a part of a new advanced energy neutral, water and additive-free toilet designed for treating waste at the point of source. The electrode was utilized in a batch process system that generated mixed oxidants from ions present in simulated urine and inactivated E. Coli bacteria. Among the mixed oxidants, the concentration of chlorine species was measured and was found to correlate to the reduction in E. Coli concentration. Finally, a new operating mode was developed that involved pulsing the voltage applied to the BDD anode led to 66% saving in energy required for disinfection and yet successfully reduced E. Coli concentration to less than the disinfection threshold.</p>Dissertatio

A problem of self-isolation in Japan: The relationship between self-isolation and COVID-19 community case

Background: The Japanese government advised mild or asymptomatic　coronavirus disease-2019 (COVID-19) cases to self-isolate at home, while more severe individuals were treated at health posts. Poor compliance with self-isolation could be a potential reason for the new outbreak. Our study aimed to find out the correlation between the rising new cases of COVID-19 and home-based patients in Japan.Methods: A secondary data analysis study was conducted with the data from COVID-19-involved databases collected from Johns Hopkins University, Japanese Ministry of Health, Labour and Welfare, and Community Mobility Reports of Google. New community cases, stringency index, number of tests, and active cases were analyzed. Using a linear regression model, an independent variable was utilized for a given date to predict the future number of community cases.Results: Research results show that outpatient cases, the stringency, and Google Mobility Trend were all significantly associated with the number of COVID-19 community cases from the sixth day to the ninth day. The model predicting community cases on the eighth day (R2=0.8906) was the most appropriate showing outpatients, residential index, grocery and pharmacy index, retail and recreation index, and workplaces index were positively related (β1=24.2, 95% CI: 20.3–26.3, P<0.0001; β2=277.7, 95% CI: 171.8–408.2, P<0.0001; β3=112.4, 95% CI: 79.8–158.3, P<0.0001; β4=73.1, 95% CI: 53- 04.4, P<0.0001; β5=57.2, 95% CI: 25.2–96.8, P=0.001, respectively). In contrast, inpatients, park index, and adjusted stringency index were negatively related to the number of community cases (β6=-2.8, 95% CI: -3.9 – -1.6, P<0.0001; β7=-33, 95% CI: -43.6 – -27, P<0.0001; β8=-14.4, 95% CI: -20.1– -12, P<0.0001, respectively).Conclusion: Outpatient cases and indexes of Community Mobility Reports were associated with COVID-19 community cases

Identifying SARS-CoV2 transmission cluster category: An analysis of country government database

Background: As a result of the high contagiousness and transmissibility of SARS-CoV-2, studying the location of the case clusters that will follow, will help understand the risk factors related to the disease transmission. In this study, we aim to identify the transmission cluster category and settings that can guide decision-makers which areas to be opened again.Methods: A thorough review of the literature and the media articles were performed. After data verification, we included cluster data from eight countries as of 16th May 2020. Clusters were further categorized into 10 categories and analysis was performed. The data was organized and presented in an easily accessible online sheet.Results: Among the eight included countries, we have found 3905 clusters and a total number of 1,907,944 patients. Indoor settings (mass accommodation and residential facilities) comprised the highest number of both number of clusters (3315/3905) and infected patients (1,837,019/1,907,944), while the outdoor ones comprised 590 clusters and 70,925 patients. Mass accommodation was associated with the highest number of cases in 5 of the 7 countries with data available. Social events and residential settings were responsible for the highest number of cases in the two remaining countries. In the USA, workplace facilities have reported 165 clusters of infection including 122 food production facilities.Conclusions: Lockdown could truly be a huge burden on a country’s economy. However, with the proper knowledge concerning the transmissibility and the behaviour of the disease, better decisions could be made to guide the appropriate removal of lockdown across the different fields and regions

Reactivity of carbenes with Lewis acids

In dieser Arbeit wurden die Reaktionen von zweiwertigen Kohlenstoffintermediaten, wie Carbene, mit Lewis-Säuren unter kryogenen Bedingungen unter Verwendung der Matrixisolationstechnik in Kombination mit quantenmechanischen Berechnungen untersucht. Die Lewis-Säuren-Carben-Wechselwirkungen bieten einen einzigartigen Ansatz zur Steuerung der Spinzustandsreaktivität (Singulett oder Triplett) von Carben. Darüber hinaus wurde die Basizität eines der reaktiven Carbene in der Gasphase auch im Hinblick auf seine Protonenaffinität unter Verwendung von Massenspektrometrie mittels der Bracketing-Methode abgeschätzt. Die wichtigsten Ergebnisse lassen sich wie folgt zusammenfassen: Die Reaktivität von Carbenen wird durch verschiedene Deskriptoren wie Geometrie, Singulett-Triplett-Energieunterschied, Philizität und Protonenaffinität bestimmt

Recrudescence of measles in India: an emerging threat

Pathogens and Global Health, 117(4), pp.326-327; 202

Investigation into Behavior of Tall Building Using Belt Truss and Outrigger Systems to Control Deflection

In this paper, the comparative study was carried out to compare the use of belt truss and outrigger in tall building to control deflection. To this end 40-storey analysis model structures composed of reinforced concrete core walls with flat slab were prepared. Models are individually analyzed with outrigger and belt truss. The static wind and earthquake analysis on building models showed that first and second optimum position of belt truss as well as outrigger was same and the third position of outrigger and belt truss was different. Based on the analysis results it was concluded that the belt truss was efficient as that of outrigger to control deflection in tall building subjected to lateral loads

Matrix Isolation Infrared and <i>Ab Initio</i> Study of the Interaction of N‑Heterocyclic Carbene with Water and Methanol: A Case Study of a Strong Hydrogen Bond

This study reports, for the first time, the experimental study of the hydrogen-bonded complexes of H₂O and MeOH with 1,3-dimethylimidazol-2-ylidene, which is a dimethyl-substituted N-heterocyclic carbene, using matrix isolation infrared spectroscopy. The hydrogen bond was found to be established between the carbene carbon and the hydrogen in the O–H group of H₂O or MeOH. The hydrogen-bonded complexes of N-heterocyclic carbenes are significantly stronger than many conventional hydrogen-bonded systems, as is evidenced by the large red shifts observed in the infrared frequencies of complexed H₂O and MeOH. The experimental results were corroborated by computations performed at MP2 and M06-2X levels of theory, using 6-311++G­(d,p) and aug-cc-pVDZ basis sets, which indicated large interaction energies (∼9 kcal mol^–1) for these complexes. Single-point calculations at the CCSD level of theory were also performed. Atoms-in-molecules (AIM), NBO, and LMOEDA analyses were also performed to understand the nature of the intermolecular interactions in these complexes. The dominant interaction was the electron delocalization from the carbene carbon to the σ* orbital of O–H of H₂O or MeOH