Energy transfer and charge transfer between semiconducting nanocrystals and transition metal dichalcogenide monolayers

: Nowadays, as a result of the emergence of low-dimensional hybrid structures, the scientific community is interested in their interfacial carrier dynamics, including charge transfer and energy transfer. By combining the potential of transition metal dichalcogenides (TMDs) and nanocrystals (NCs) with low-dimensional extension, hybrid structures of semiconducting nanoscale matter can lead to fascinating new technological scenarios. Their characteristics make them intriguing candidates for electronic and optoelectronic devices, like transistors or photodetectors, bringing with them challenges but also opportunities. Here, we will review recent research on the combined TMD/NC hybrid system with an emphasis on two major interaction mechanisms: energy transfer and charge transfer. With a focus on the quantum well nature in these hybrid semiconductors, we will briefly highlight state-of-the-art protocols for their structure formation and discuss the interaction mechanisms of energy versus charge transfer, before concluding with a perspective section that highlights novel types of interactions between NCs and TMDs

Examining queue-jumping phenomenon in heterogeneous traffic stream at signalized intersection using UAV-based data

© 2020, Springer-Verlag London Ltd., part of Springer Nature. This research presents an in-depth microscopic analysis of heterogeneous and undisciplined traffic at the signalized intersection. Traffic data extracted from the video recorded using an unmanned aerial vehicle (UAV) at an approach of a signalized intersection is analyzed to study the within green time dynamics of traffic flow. Various parameters of Wiedemann 74, Wiedemann 99, and lateral behavior models used in microscopic traffic simulation package, Vissim, are calibrated for the local heterogeneous traffic. This research is aimed at exploring the queue-jumping phenomenon of motorbikes at signalized intersections and its impact on the saturation flow rate, travel time, and delay. The study of within green time flow dynamics shows that the flow of traffic within green time is not uniform. Surprisingly, the results indicate that the traffic flow for the first few seconds of the green time is significantly higher than the remaining period of green time, which shows a contradiction to the fact that traffic flow for the first few seconds is lower due to accelerating vehicles. Mode-wise traffic counted per second shows that this anomaly is attributed to the presence of motorbikes in front of the queue. Consequently, the outputs of simulation results obtained from calibrated Vissim show that the simulated travel time for motorbikes is significantly lower than the field-observed travel times even though the average simulated traffic flow matches accurately with the field-observed traffic flow. The findings of this research highlight the need to incorporate the queue-jumping behavior of motorbikes in the microsimulation packages to enhance their capability to model heterogeneous and undisciplined traffic

Electrochemical treatment of simulated sugar industrial effluent: Optimization and modeling using a response surface methodology

The removal of organic compounds from a simulated sugar industrial effluent was investigated through the electrochemical oxidation technique. Effect of various experimental parameters such as current density, concentration of electrolyte and flow rate in a batch electrochemical reactor was studied on the percentage of COD removal and power consumption. The electrochemical reactor performance was analyzed based on with and without recirculation of the effluent having constant inter-electrodes distance. It was found out that the percentage removal of COD increased with the increase of electrolyte concentration and current density. The maximum percentage removal of COD was achieved at 80.74% at a current density of 5 A/dm2 and 5 g/L of electrolyte concentration in the batch electrochemical reactor. The recirculation electrochemical reactor system parameters like current density, concentration of COD and flow rate were optimized using response surface methodology, while COD removal percents were maximized and power consumption minimized. It has been observed from the present analysis that the predicted values are in good agreement with the experimental data with a correlation coefficient of 0.9888

Continuous fixed bed adsorption studies of Rhodamine-B dye using polymer bound adsorbent

53-58<span style="font-size:11.0pt;mso-bidi-font-size: 10.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:"times="" roman";letter-spacing:-.1pt;mso-ansi-language:="" en-gb;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="" lang="EN-GB">An eco-friendly adsorbent is developed by coating polyaniline over an activated carbon prepared from the seeds of Prosopis Juliflora using ZnCl2 as an activating agent (PPAC). The polymer bound adsorbent has good adsorption characteristics with a surface area of 1028 m2/g. A continuous flow fixed bed study is carried out by using PPAC as an adsorbent packed in a column for the removal of Rhodamine-B dye from aqueous solution. The effect of operating parameters such as flow rate, bed height and inlet dye concentration on the sorption characteristics of RB <span style="font-size:11.0pt; mso-bidi-font-size:10.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:="" "times="" roman";mso-bidi-font-family:times-roman;letter-spacing:-.1pt;="" mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:ta"="" lang="EN-GB">have been investigated at room temperature (30°C) and the natural pH of dye solution. On increasing the influent concentration from 25 to 75 mg/L, the volume of effluent treated decreases from 3800 to 2950 mL. The kinetic models suggested by Bohart-Adam, Thomas and Yoon-Nelson are employed to study this adsorption system. The YN model fits exceptionally well for the adsorption of RB onto PPAC with respect to all of the calculated parameters with high correlation coefficient (0.9431 to 0.9668) and low standard deviation (0.04 to 0.75). </span

Analysis of 17 beta-estradiol (E-2) role in the regulation of corpus luteum function in pregnant rats: Involvement of IGFBP5 in the E-2-mediated actions

Background: In several species, considerably higher levels of estradiol-17 (E-2) are synthesized in the CL. E-2 has been suggested to participate in the regulation of luteal steroidogenesis and luteal cell morphology. In pregnant rats, several experiments have been carried out to examine the effects of inhibition of luteal E-2 synthesis on CL structure and function. Methods: During days 12-15 of pregnancy in rats, luteal E-2 was inhibited by way of daily oral administration of anastrozole (AI), a selective non-steroidal aromatase inhibitor, and experiments were also performed with E-2 replacement i. e. AI+ E-2 treatments. Luteal tissues from different treatment groups were subjected to microarray analysis and the differentially expressed genes in E-2 treated group were further examined for expression of specific E-2 responsive genes. Additional experiments were carried out employing recombinant growth hormone preparation and flutamide, an androgen receptor antagonist, to further address the specificity of E-2 effects on the luteal tissue. Results: Microarray analysis of CL collected on day 16 of pregnancy post AI and AI+ E-2 treatments showed significantly lowered cyp19a1 expression, E-2 levels and differential expression of a number of genes, and several of them were reversed in E-2 replacement studies. From the differentially expressed genes, a number of E-2 responsive genes were identified. In CL of AI pregnant rats, non-significant increase in expression of igf1, significant increase in igbp5, igf1r and decrease in expression of Era were observed. In liver of AI treated rats, igf1 expression did not increase, but GH treatment significantly increased expression that was further increased with AI treatment. In CL of GH and AI+ GH treated rats, expression of igfbp5 was higher. Administration of flutamide during days 12-15 of pregnancy resulted in non-significant increase in igfbp5 expression, however, combination of flutamide+ AI treatments caused increased protein expression. Expression of few of the molecules in PI3K/Akt kinase pathway in different treatments was determined. Conclusions: The results suggest a role for E-2 in the regulation of luteal steroidogenesis, morphology and proliferation. igfbp5 was identified as one the E-2 responsive genes with important role in the mediation of E-2 actions such as E-2-induced phosphorylation of PI3K/Akt kinase pathway

Mathematical analysis of the effects of operating conditions and rheological behaviour of reaction medium on biodiesel synthesis under ultrasound irradiation

Ultrasound assisted transesterification has recently been introduced as an effective technology for biodiesel synthesis. However, the behaviour of micro bubbles under ultrasound is affected by operating conditions or rheological properties of reaction mixtures. This paper aims at investigating the changes of micro bubbles characteristics when operating conditions or rheological behaviour of the reaction medium are altered. The mechanistic simulation of micro bubbles was combined with the CFD simulation of reaction mixture to achieve the aims of this work. Continuity and momentum equations of Keller-Miksis model were employed along with reaction, mass and energy balances to simulate different characteristics of micro bubbles such as temperature, pressure, oscillation velocity, maximum radius of micro bubble, equilibrium state of bubble content, diffusion rates of reaction compounds towards bubbles and reaction within bubbles. It was found that among different combinations of reaction temperature, reactants ratio and intensity of ultrasound irradiation, the last one played the most important role. Radius, internal temperature and pressure of bubbles significantly increased with power amplitude due to stronger expansion and greater energy accumulation. At the same time, increase in reaction temperature and alcohol concentration made the bubbles characteristics rather moderate. It was also found that the growth of bubbles radius was reduced by about 4 times as the reaction progressed and the reaction mixture became more viscous and dense. The maximum internal temperature and pressure decreased by about 178 K and 220 bar due to moderate expansion of bubbles. Oscillation velocity was also restricted in this situation