Magnetotransport properties of a magnetically modulated two-dimensional electron gas with the spin-orbit interaction

We study the electrical transport properties of a two-dimensional electron gas with the Rashba spin-orbit interaction in presence of a constant perpendicular magnetic field $(B_0 \hat z)$ which is weakly modulated by ${\bf B_1} = B_1 \cos (q x) \hat z$, where $B_1 \ll B_0$ and $q = 2 \pi/a$ with $a$ is the modulation period. We obtain the analytical expressions of the diffusive conductivities for spin-up and spin-down electrons. The conductivities for spin-up and spin-down electrons oscillate with different frequencies and produce beating patterns in the amplitude of the Weiss and Shubnikov-de Haas oscillations. We show that the Rashba strength can be determined by analyzing the beating pattern in the Weiss oscillation. We find a simple equation which determines the Rashba spin-orbit interaction strength if the number of Weiss oscillations between any two successive nodes is known from the experiment. We compare our results with the electrically modulated 2DEG with the Rashba interaction. For completeness, we also study the beating pattern formation in the collisional and the Hall conductivities.Comment: 11 pages, 5 figures, re-written with new result

Inset Fed Rectangular Patch Antenna Design for ISM Band Applications

Wireless communication systems rely on efficient and compact antennas to transmit and receive signals. Microstrip patch antennas have gained popularity due to their small size, low profile, and ease of fabrication. In this study, an inset fed microstrip rectangular patch antenna using a partial ground plane is designed for ISM band applications in the frequency range of 2.4 - 2.4835 GHz. The antenna is made on a low-cost FR4 substrate with a dielectric constant of 4.3 and a thickness of 1.6 mm. The dimensions of the antenna is 28.35 × 37.58  mm2. The antenna is fed by an inset feedline, which provides a compact and efficient feeding mechanism. The design of the antenna is carried out using CST Microwave Studio software. The performance of the antenna is evaluated based on various parameters such as return loss, bandwidth, VSWR, directivity, gain, and radiation pattern. The simulation results indicate that the proposed antenna achieves a return loss (S11) of -27.339 dB, a bandwidth of 0.01478 GHz (147.8 MHz), and a VSWR of 1.09. Additionally, the antenna provides a gain of 2.97 dBi, a directivity of 4.7 dBi, and an efficiency of -1.726 dB (67.20%). Overall, this design meets the requirements of decreased antenna size, lightweight, low profile, cost-effectiveness, simple manufacturing, and good performance for ISM band applications

New Sufficient Conditions for Hamiltonian Paths

A Hamiltonian path in a graph is a path involving all the vertices of the graph. In this paper, we revisit the famous Hamiltonian path problem and present new sufficient conditions for the existence of a Hamiltonian path in a graph

Pomegranate juice attenuates acetaminophen induced hepatotoxicity in rat model of experiment

Background: Pomegranate fruit has high contents of various polyphenols and antioxidants due to which it possesses variety of therapeutic properties. In particular, pomegranate fruit peel and flowers have exhibited high antioxidant activity in different studies. Acetaminophen (APAP) overdose is the most common cause of drug induced liver toxicity including both accidental and intentional types. In our study, we investigated the protecting mechanism of pomegranate fruit juice (PJ) against toxicity caused by APAP in Wistar rats.Methods: Rats were fed with 0.2% (w/v) pomegranate fruit extract as prophylaxis to counter single dose of APAP (2 g/kg, p.o). After that variation in levels of glutathione, glutathione peroxidase (GPx), and glutathione reductase (GR) were marked.Results: A single dose of APAP elevated serum toxicity markers including lipid peroxidation. A simultaneous sharp depletion of glutathione and its metabolizing enzymes glutathione peroxidase (GPx), glutathione reductase (GR) was observed. Oral doses of PJ at (0.1% & 0.2% w/v) caused a significant (P<0.001) reduction in toxicity marker enzymes. A striking elevation in antioxidant armory was seen as in response to PJ.Conclusion: The results provide a clear picture of the defensive effect of PJ against APAP induced hepatic toxicity

IN VITRO ANTI-INFLAMMATORY AND HEPATOPROTECTIVE ACTIVITY OF TURMESAC®

Objective: In this study, we investigated the hepatoprotective activity of Turmesac® on Human liver cells (HepG2 cell line) and anti-inflammatory effect on Murine macrophages (Raw 264.7 cell line) by flow Cytometry. Methods: Cell viability of HepG2 and Raw 264.7 cells determined by the MTT&nbsp;[3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] assay to identify a non-cytotoxic concentration of Turmesac® for the respective cell lines after 24 h exposure period. Further hepatoprotective effect of Turmesac® was performed in H2O2 treated liver cells using H2DCF-DA staining by flow cytometry. The anti-inflammatory potency of Turmesac® was evaluated in Lipopolysaccharide (LPS 2µg/ml) stimulated Murine Raw 264.7 macrophages by measuring the relative fluorescence intensity of 2 cytokines, Interleukin-8(IL-8) and (Interleukin-12) IL-12 by flow cytometric analysis. Results: Turmesac® concentrations of less than 50μg/ml did not show significant cytotoxicity on both HepG2 and Raw 264.7, cell lines following the treatment period of 24 h and selected 50μg/ml as the optimum concentration for hepatoprotective and anti-inflammatory models. The reactive oxygen species (ROS) study revealed that Turmesac® (50μg/ml) effectively suppressed the H2DCF-DA expression in HepG2 cells. Secondly, Turmesac® significantly suppressed the anti-inflammatory cytokine expressions of IL-8 and IL-12 in LPS pre-stimulated cells categorising as a potentially potent anti-inflammatory drug. The mean fluorescence intensity percentage of IL-8 is control 8.86, LPS 50.49, Turmesac® 19.63 and IL12 is control 10.41, LPS 68.94, and Turmesac® 15.79 respectively. Conclusion: This study highlighted that Turmesac® could be considered as a promising hepatoprotective and anti-inflammatory compound and a therapeutic agent in curing liver-related and inflammation-related diseases

Zero-field spin splitting in a two-dimensional electron gas with the spin-orbit interaction revisited

We consider a two-dimensional electron gas (2DEG) with the Rashba spin-orbit interaction (SOI) in presence of a perpendicular magnetic field. We derive analytical expressions of the density of states (DOS) of a 2DEG with the Rashba SOI in presence of magnetic field by using the Green's function technique. The DOS allows us to obtain the analytical expressions of the magnetoconductivities for spin-up and spin-down electrons. The conductivities for spin-up and spin-down electrons oscillate with different frequencies and gives rise to the beating patterns in the amplitude of the Shubnikov de Hass (SdH) oscillations. We find a simple equation which determines the zero-field spin splitting energy if the magnetic field corresponding to any beat node is known from the experiment. Our analytical results reproduce well the experimentally observed non-periodic beating patterns, number of oscillations between two successive nodes and the measured zero-field spin splitting energy.Comment: 5 pages, 2 figure

Detection of crystal structure of chemically-deposited copper selenide thin films

A low cost Chemical Bath Deposition (CBD) system has been developed in our laboratory for the preparation of copper selenide thin film. Good quality thin films of smooth surface of copper selenide thin films of compositions Cu2-xSe (x = 0.1–0.5) and Cu3Se2 were deposited using sodium selenosulfate as a source of selenide ions. Crystal structure of copper selenide (Cu1.8Se and Cu3Se2) thin films has been identified by X-ray diffraction (XRD) method. When the film is annealed at 250ºC in air, the phases of Cu1.8Se and Cu3Se2 become crystalline, with structures of cubic (berzelianite) and tetragonal, respectively, whereas the as-deposited film was found to be disorder. The crystallinity is very low in as-deposited samples, which improves on annealing in air at 250ºC. The grain size of the as-deposited samples was very small, which was increased about 30% owing to annealing in air at 250ºC.Author Affiliation: Al-Mamun, S H Firoz and A B M O Islam 1.Department of Physics, University of Dhaka, Dhaka-1000, Bangladesh 2.Institute of Glass and Ceramic Research and Testing Bangladesh Council for Scientific and Industrial Research (BCSIR), Dhaka-1205, Bangladesh E-mail : [email protected] of Physics, University of Dhaka, Dhaka-1000, Bangladesh 2.Institute of Glass and Ceramic Research and Testing Bangladesh Council for Scientific and Industrial Research (BCSIR), Dhaka-1205, Banglades