Measurement of Transport Number of Lithium in Glycerol Assisted by Fourier Transform Spectroscopy Analysis: Progress towards Elaboration of Optimal Electrolyte of Friendly Environmental Battery

Up to now, a great deal of research investigations on lithium ion conductors has been carried out, because they are potentially utilized in the solid electrolytes of the batteries and the electrochemical devices. However, in order to elaborate new ecological batteries of lithium, it becomes primordial to study and understand the properties of transport of the lithium electrolytes using eco-friendly solvents, with view perhaps to find out the best electrolyte for such devices. In fact, the electromotive forces (EMFs) of lithium chloride electrolyte in the hydrogen-bonded solvents glycerol, were measured using the concentration cells (CCs) 0.005/0.05 and 0.05/0.5. Then the transport numbers of the lithium-ion were deduced by means of the Nernst equation in combination with the Debye-Huckel limiting law. Whilst the activation energy values were calculated from the parameters of the fitting of the transference number data to the empirical power law, yielding a regression coefficient of 95.9% for the most concentrated concentration cell. The structure and interactions in the lithium electrolyte solution were studied by vibrational Infra-Red spectroscopy. The experimental data were discussed and compared to those obtained previously, using impedance spectroscopy of glass-forming glycerolate lithium electrolytes for the same purpose. Despite the enormous difference between their viscosities; glycerol shows similar activation energy (i.e. 31.40 kJ.mol–1) with water (i.e. 31.73 kJ.mol–1), in particular at very low concentration, confirming both solvents being hydrogen-bonded. Besides, this study suggests the utilization of the glycerol-lithium ion electrolyte for future conception of ecological lithium-ion battery, rather than those using ion electrolyte polymer currently on the market. Similarly to relaxation and conductivity, the transport number data suggests that the diffusion of conformational states is also monitoring the overall lithium ion transport mechanism.

A Study of Commuter’s Shift Behaviour Towards New Age Convenient Transport Services

This study identifies the determinants of commuter’s perception and shift behaviour towards new-age transport services. Convenience is an essential determinant in influencing consumer preferences. Multiple factors such as accessibility, convenience, cost of transport, number of transfers during the journey and waiting time are a few salient variables that influence the commuter’s shift to a new transport mode. Responses from ongoing commuters were collected by using a structured questionnaire from the users and non-users of the metro. The collected data were analysed. The study reveals that categorical variables such as age, gender and occupation have some degree of influence in commuters’ shift behaviour towards new-age transport services. The study will provide insights to formulate a future strategy to improve the acceptance of new-age transportation.

Using a microheterogeneous model to assess the applicability of ion-exchange membranes in the process of reverse electrodialysis

This paper shows the possibility of using a microheterogeneous model to describe the properties of ion-exchange membranes and calculate the characteristics of a reverse electrodialyzer from the data obtained. We studied the properties of eight samples of heterogeneous cation exchange membranes (two samples of each type of membrane). The samples differed in the year of issue and storage conditions. It is shown that for heterogeneous ion-exchange membranes MK-40 and MA-41, the samples' properties can differ significantly. The counterions transport numbers calculated within the framework of the microheterogeneous model for Ralex membranes differ insignificantly. The counterion transport number in 1 mol/L sodium chloride solution is 0.96 for Ralex CM and 0.98 ± 0.01 for Ralex AMH. For the MK-40 membrane, the transport number in the same solution is 0.94 ± 0.04, and for the MA-41 membrane, it is 0.85 ± 0.1. The possibility of calculating the transport numbers and predicting the open-circuit voltage based on simple physicochemical measurements allows selecting the best membrane pairs for the reverse electrodialysis process. Comparison of the open-circuit potential value calculated using the obtained transfer numbers with experimental data showed that in the case of using Ralex membranes, the difference between the experimental and calculated values is 2%. The calculated value of the open circuit potential was 0.19 V/membrane pair or 1.69 V for the investigated reverse electrodialyzer with nine pair chambers.

Impact Brazil Covid-19 Survey: a cross-sectional study on the mental health status of Brazilians

Background: Citizens’ mental health has been challenged by the advent of a new reality during the COVID-19 pandemic, which has imposed a new pattern of behavior on everyone. In this context, it is important to clarify how this new reality is impacting the mental health of Brazilian citizens. Design and setting: Cross-sectional study, Brazil. Methods: This work is part of the “IMPACT RESEARCH COVID19 BRAZIL: EVALUATING THE PANDEMIC BY COVID-19 THROUGH 24 QUESTIONS”. The implementation of the survey was carried out by distributing a questionnaire through social networks. Data collected was used to measure how much the experience of citizens in the pandemic period has impacted on their mental heath. All data analysis was performed using R. Results: Self-reported experience of negative symptoms and behaviors (sadness, loneliness, stress, anxiety, impatience), as well as exaggerated consumption of substances (alcohol, drugs) and use of electronic recreation (games), differs with age, with the youngest being the ones who most reported such experience, regardless of gender. However, no relevant statistical correlations were found between the variables mentioned above and others that could explain them, such as use of public transport, number of cohabitants, etc. Conclusions: other factors, related to distancing/social isolation, may be contributing to these negative manifestations.

Humidity Driven Transition from Insulator to Ionic Conductor in Portland Cement

This work aims to assess ionic conduction in anhydrous cement particles and hydrated cement pastes with aging periods of 5–25 days. When a cement sample was humidified (relative humidity = 100%) over the range of 50–100 °C, it exhibited bulk conductivities of 10−3–10−2 S cm−1, regardless of the hydration level, whereas the interfacial conductivities varied in the range of 10−7–10−3 S cm−1, depending on the structural defects or conduction pathways of the sample. Both the bulk and interfacial conductivities were increased to 0.01 S cm−1 or higher at 100 °C, although the sample required previous moistening with water mist. The major charge carrier in the sample was determined to be hydroxide ions, and the total ion transport number was approximately 1. Exposing the sample to a mixture of carbon dioxide and water vapor caused a decrease in the bulk and interfacial conductivities; however, the bulk conductivity was returned to the initial value by treatment with an acid.