Genotypic and Phenotypic Characterization of Antimicrobial Resistance Profiles in Non-typhoidal Salmonella enterica Strains Isolated From Cambodian Informal Markets

Non-typhoidal Salmonella enterica is a pathogen of global importance, particularly in low and middle-income countries (LMICs). The presence of antimicrobial resistant (AMR) strains in market environments poses a serious health threat to consumers. In this study we identified and characterized the genotypic and phenotypic AMR profiles of 81 environmental S. enterica strains isolated from samples from informal markets in Cambodia in 2018–2019. AMR genotypes were retrieved from the NCBI Pathogen Detection website (https://www.ncbi.nlm.nih.gov/pathogens/) and using ResFinder (https://cge.cbs.dtu.dk/services/) Salmonella pathogenicity islands (SPIs) were identified with SPIFinder (https://cge.cbs.dtu.dk/services/). Susceptibility testing was performed by broth microdilution according to the Clinical and Laboratory Standards Institute (CLSI) standard guidelines M100-S22 using the National Antimicrobial Resistance Monitoring System (NARMS) Sensititre Gram Negative plate. A total of 17 unique AMR genes were detected in 53% (43/81) of the isolates, including those encoding tetracycline, beta-lactam, sulfonamide, quinolone, aminoglycoside, phenicol, and trimethoprim resistance. A total of 10 SPIs (SPI-1, 3–5, 8, 9, 12–14, and centisome 63 [C63PI]) were detected in 59 isolates. C63PI, an iron transport system in SPI-1, was observed in 56% of the isolates (n = 46). SPI-1, SPI-4, and SPI-9 were present in 13, 2, and 5% of the isolates, respectively. The most common phenotypic resistances were observed to tetracycline (47%; n = 38), ampicillin (37%; n = 30), streptomycin (20%; n = 16), chloramphenicol (17%; n = 14), and trimethoprim-sulfamethoxazole (16%; n = 13). This study contributes to understanding the AMR genes present in S. enterica isolates from informal markets in Cambodia, as well as support domestic epidemiological investigations of multidrug resistance (MDR) profiles.

Controlling the corrosion and hydrogen gas liberation inside lead-acid battery via PANI/Cu-Pp/CNTs nanocomposite coating

The liberation of hydrogen gas and corrosion of negative plate (Pb) inside lead-acid batteries are the most serious threats on the battery performance. The present study focuses on the development of a new nanocomposite coating that preserves the Pb plate properties in an acidic battery electrolyte. This composite composed of polyaniline conductive polymer, Cu-Porphyrin and carbon nanotubes (PANI/Cu-Pp/CNTs). The structure and morphology of PANI/Cu-Pp/CNTs composite are detected using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Based on the H2 gas evolution measurements and Tafels curves, the coated Pb (PANI/Cu-Pp/CNTs) has a high resistance against the liberation of hydrogen gas and corrosion. Electrochemical impedance spectroscopy (EIS) results confirm the suppression of the H2 gas evolution by using coated Pb (PANI/Cu-Pp/CNTs). The coated Pb (PANI/Cu-Pp/CNTs) increases the cycle performance of lead-acid battery compared to the Pb electrode with no composite.

Direct re-usability of lead-plated tin bronze as negative plate for lightweight lead-acid battery

Lead-plated tin bronze mesh was adopted as the negative grid to assembly 2V-DZM-20Ah lead-acid battery. Compared with the conventional negative plate, the weight of each tin bronze plate reduced by about 17 g, the weight of the single-cell was reduced by 13.67%, and the mass specific capacity of the single-cell was increased by about 7 Wh·Kg−1. The sulfation of the negative side was suppressed due to the high electronic conductivity of bronze-based negative plate. The failure expansion of the positive side was also restricted due to the strong negative structure. The dissembled negative grid of lead-plated tin bronze after 450 cycles of 100% discharge of degree was still intact and dense. After the dissembled negative grid was reassembled into a 2V single cell, the battery exhibited similar performance to that with a new one. Generally speaking, direct re-usability of tin bronze based grid sharply simplifies the grid recovery and opens an greatly attracting direction for developing lightweight, high energy technique of lead-acid batteries.

Review on Laminated Busbars used in High Frequency Inverters

Improvement in the efficiency and cost in the high frequency inverter will play a major role in its applications like electrical vehicles (EV). A high voltage IGBTs are used in inverters to bear the voltage peaks across the IGBT switch at the turning off period of switch. By decreasing the value of voltage peak, can reduce the voltage rating of IGBT switch, by which the system cost will decrease. Decreasing the value of voltage peak can be achieved by decreasing the inductance of the inverter circuit which includes turned on switch inductance, DC link capacitors inductance and connecting wires inductance. By replacing the connecting wires with a laminated busbar in an inverter, the inductance value of a connecting wires can be reduced. Laminated bus bar is a parallel conductor plates separated by a dielectric medium. Upper plate is considered as positive plate and lower plate is a negative plate. In this paper it gives a detailed information about laminated busbar with different designs, using different conductive materials, their calculated inductance in ANSYS 3D FEM software and concluding with suitable laminated busbar for high frequency inverter.

Behavior Modification of Nanostructured PbO2 Electrodes in Lead Acid Batteries Changing Electrolyte Concentration and Separator

Currently, lead acid battery is extensively investigated owing to its prevalent use as a startinglighting and ignition device. An essential role for electrochemical reactions is played by the surface area available for conversion reactions and a possible approach is the use of nanostructured electrodes. In this work, lead dioxide nanostructured electrodes were tested in order to investigate the dependence of the charge and discharge behaviour on some parameters such as electrolyte concentration, and a new type of thin separator. In this last case, it is possible to reduce the size of the cell by using a very thin separator comparable to the nanostructured electrode thickness. Besides, a low concentration of electrolyte was also tested for studying its influence on the performance of a nanostructured electrode. Lead dioxide electrodes were cycled at 1C-rate and discharged to a cutoff voltage of 1.2 V up to 90% of the gravimetric capacity. Electrodes were assembled in a zero gap configuration using a commercial negative plate as counter-electrode with a large excess of active mass in comparison to the nanostructured one. Tests were conducted in very stressful conditions, in order to compare the behaviour of this new type of battery with that of the commercial one.

Next Generation Transparent Supercapacitor Materials Poster

Supercapacitor utilizes the nano-scaled pores to increase the surface area indefinitely and shortens the distance between the positive and negative plate, on the account that some larger particles cannot fit into the pores. According to the capacitance equation “capacitance = εrε0(area/distance),” as the distance decreasing and area increasing, the magnitude of the capacitance is tremendously magnified. A transparent supercapacitor describes a supercapacitor that has a high optical transmittance. If the intensity of light that transmits across the substance is higher than the rate that it is blocked or reflected. The substance possesses transparency. The flexibility of transparent supercapacitors is another important area of study. It generalizes a combination of stretchability, bendability, or compressibility. In real life, it’s important to obtain the optimal optical transmittance, flexibility, and electrical conductivity for future devices such as smart glasses. These characteristics enable us to develop something more complex and advanced in the future.