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The dielectric properties of a material determine its response of the material to the Electromagnetic field (EM field). It comprises dielectric constant (ε′), which is the ability to store energy of EM fields, and dielectric loss (ε′′) which is the amount of dissipated Electromagnetic energy in the form of heat. Dielectric properties are affected by various factors such as frequency, temperature, bulk density, moisture content, etc. Dielectric constant and dielectric loss were determined in this study for milk powders viz. Whole Milk Powder, Skim Milk Powder, and Infant Milk Powder at various microwave frequencies (5.68, 7.45, 10.25GHz). The method used to determine dielectric properties is the Two-point Method which is implemented on a microwave bench. It became apparent that when frequency increases dielectric constant decreases and dielectric loss first decreases and then increases. It was also observed that the fat content can have an impact on the milk powders’ dielectric properties. [ABSTRACT FROM AUTHOR]

Dielectric constant (ε′) and dielectric loss factor (ε′′) of gluten-free grains viz., Finger millet, Amaranth and Buckwheat in powder form were measured at room temperature (22∘C) at frequency 9.76GHz for different moisture content samples. The method used was the Two-Point method which is based on the transmission line technique. Microwaves were employed to investigate dielectric properties and their moisture dependence. The results showed that dielectric constant and dielectric loss of Gluten-free grains increase with the increase in moisture content. It shows that for higher moisture there are more free molecules in comparison to bound water molecules. This work can be an effective guide in designing a moisture meter for gluten-free grains. [ABSTRACT FROM AUTHOR]

Acinetobacter is emerging as one of the major nosocomial infectious pathogens, facilitated by tolerance to desiccation and multidrug resistance. Quorum sensing (autoinducer-receptor mechanism) plays role in biofilm formation in Acinetobacter, though its role in regulation of other virulence factors is yet to be established. Phylogenetic studies indicate that Acinetobacter baumannii is closely related to Burkholderia ambifaria but its quorum sensing genes ( abaI and abaR) were acquired horizontally from Halothiobacillus neapolitanus. The prospects of quorum quenching to control the infections caused by Acinetobacter have also been discussed. [ABSTRACT FROM AUTHOR]

Exploring the morphogical and structural properties along with gas sensing applications both pure and Ti-doped SnO2 ultra-thin films, were meticulously crafted on micromachined silicon substrate heater devices using a combination of classical soft chemical processes and hydrothermal techniques (SCPHTP). The fabrication process involved a two-step approach: initially, a 20nm layer of tin oxide was hydrothermally deposited onto the substrates, followed by annealing in wet air at 600∘C for 5h using a standardized temperature variation protocol. Subsequently, secondary layers with thicknesses of 20, 40 and 60nm were sequentially deposited onto the tin dioxide devices and oxidized in wet air at 550∘C and 600∘C for 20h each, using the same temperature modulation scheme. Throughout this process, the hydrothermal deposition temperature remained constant at 180∘C for both the initial and secondary layers of tin dioxide deposition. Additionally, Ti layers with thicknesses of 4 and 8nm were deposited onto the 20nm + 40nm system, subjected to annealing at 550∘C for 20h, followed by 1-min annealing in dry O2 at 700∘C and 800∘C, respectively, using a Rapid Thermal Annealing (RTA) system. Characterization of the crystalline and surface structures of the devices revealed a transformation of the soft chemical tin dioxide solution into the cassiterite structure of SnO2, resulting in uniform large surface areas for the sensor devices. Moreover, Ti metal layers of 4 and 8nm thicknesses were fully converted into TiO2 on the surface of the devices. Subsequent testing showcased higher current values in sandwich systems of 20nm + 60nm and 20nm + 40nm compared to the 20nm + 20nm configuration. Sensitivity and stability assessments for various volatile organic compounds (VOCs) and CO gases at a constant DC temperature of 400∘C indicated excellent performance, with sensitivity to CO gas being contingent on relative humidity (RH). Notably, RTA-annealed and Ti-8 nm-doped sensor devices exhibited superior sensitivity and reproducibility, particularly when treated at 800∘C in dry O2 for 1min. This heightened performance can be attributed to the occupation of chloride ions in the oxygen sites of the as-synthesized SnO2, resulting in enhanced sensing capabilities for VOC gases. [ABSTRACT FROM AUTHOR]

Acinetobacter baumannii and Pseudomonas aeruginosa are pathogens capable of colonizing the same infection sites and employing N-acyl homoserine lactone (AHL) based quorum-sensing systems to co-ordinate biofilm formation. Hence, the effect of P. aeruginosa AHLs on biofilm formation by A. baumannii and vice versa were investigated using the biofilm impaired quorum sensing mutants, A. baumannii M2 (abaI::Km) and P. aeruginosa PAO-JP2. Complementing the mutants with heterologous, extracted and pure AHLs increased biofilm mass significantly. The surface area coverage and biovolume also increased significantly as observed by confocal scanning laser microscopy which corroborated scanning electron microscope analysis. Autoinducer synthase gene promoters of A. baumannii, P( abaI)-lacZ, and P. aeruginosa, P( lasI)-lacZ, were induced (p < 0.05) by heterologous AHLs. Growth of A. baumannii was not inhibited by pyocyanin of P. aeruginosa which may allow their co-existence and interaction in the clinical setting, thereby affecting the severity of combined infections and therapeutic measures to control them.

Dielectric constant and loss factor of Raj-4120 variety of Indian wheat were determined in powder form (grain size 125 to 150 micron) at room temperature. Microwaves at three different frequencies were employed in C-band, X-band and Ku-band respectively for investigating frequency dependence of dielectric parameters of the sample. Bulk dielectric values of the sample were determined by employing the dielectric mixture relations, such as, half power mixture equation, Landau and Lifshitz, Looyenga equation etc.