Terahertz Slonczewski propagating spin waves and large output voltage in antiferromagnetic spin-Hall nano-oscillators

We study theoretically antiferromagnet (AFM) based spin-Hall nano-oscillators (SHNOs) consisting of a nano-constriction (NC) in a thin-film uniaxial AFM. By solving the derived SW equation we evidence radially propagating spin waves (SWs) at THz frequencies similar to the Slonczewski SWs known at GHz frequencies for a ferromagnet-based SHNO. We predict a minimum threshold current for a specific NC radius accessible by the state-of-the-art nanotechnology. The exchange interaction enhanced spin pumping for AFMs leads to a strong thickness dependent threshold frequency. We show that the uniaxial AFMs generate ac electrical fields via spin pumping that are three orders of magnitude larger than reported for biaxial AFMs. Our work enhances the fundamental understanding of current-driven SWs in AFM-SHNOs and enables optimization of practical devices in terms of material choice, device geometry, and frequency tunability. The propagating SWs offer remote THz signal generation and an efficient means for synchronization of SHNOs when aiming at high power

The Effect of Real Exchange Rate on Current Account

This research studies the impact of real Gross Domestic Production (GDP) and real exchange rate on the Current Account position in Jordan, during the quarterly periods from 2008 to 2022. The study reviews the literature on the theoretical framework around the impact of real GDP and fluctuations of the real exchange rate on the current account status. This study describes the performance of the current account during the study period and applies the appropriate econometric tests to an economic model. The main results show a significant, positive effect of real GDP growth in improving the status and sustainability of the current account; output growth indicates an increase in production leading to higher levels of exports and lower levels of imports. The results did not show a significant effect of the real exchange rate on the current account position, which is largely attributed to the stabilization policy of exchange rate pursued by the Central Bank of Jordan since October 1995

Micromorphological studies on leaf, fruit and pollen of four species from Typhaceae (Typha laxmannii, T. azerbaijanensis, T. minima and T. lugdunensis) from Iran, and their thematic significance

Previous research has made it clear that the intrinsic taxonomy encountered difficulties in identifying speciesin the genus Typha. Therefore, in the present study we have tried to investigate the micromorphological characteristics of pollens, achenes and leaves as well as their systematic utility. Four Typha species identified from the Iranian flora i.e. Typha minima Funk in Hoppe, Typha lugdunensis Chab., Typha azerbaijanensis Hamdi & Assadi and Typha laxmannii Lepechin were taken into consideration. Three of them are easily distinguishable with their closest relative i.e. T. laxmannii Lepechin. Scanning electron microscopy was used to examine pollens, achenes and leaves of the four taxa of the proposed Typha from Iran. A part of these micromorphological studies attempted to investigate achenes, pollens and leaf characteristics of these species under SEM. Interestingly, Typha martini Jordan is also considered as a synonym of T. lugdunensis. The study does not only discuss relationships between close species but it also clarifies their geographical patterns. Finally, a diagnostic key is provided for the distribution of the four Typha species in Iran. The results show that the ornamentation characters of pollens, achenes and leaf cells prove to be very helpful. Ornamentation of pollens and achenes could be used to distinguish between the four morphological types. Micromorphological studies on achenes, pollens and leaves of Typha were found useful with respect to taxa differentiation, hence it provides a key to make distinctions between species orgroups of species

Civil disobedience during reformation era

The removal of Anwar Ibrahim as Deputy Prime Minister of Malaysia in September 1998 was a shock to the nation. This is because there were a series of street demonstrations in 1998 until 2001 that gave birth to reformasi (reform) movement. People thought that the dismissal was unfair due to personal conflict between the Prime Minister, Dr. Mahathir and Anwar Ibrahim. The purpose of this paper is to analyze the emergence of civil disobedience during reform movement and to identify the actors involved in mobilizing civil disobedience. The analysis shows what the main reason behind the outbreak of civil disobedience was the result of government actions that weakened democracy through the restriction of political rights and civil liberties. In this respect, the removal of Anwar Ibrahim was only a triggering factor. Furthermore, the actors who were involved in acts of civil disobedience include students, young people, opposition parties, non government organizations (NGOs) and activists. These groups cooperated to seek justice for Anwar Ibrahim and also raised issues related to corruption, cronyism and abuse of power in the government. Consequently, support for the Barisan Nasional (National Front) coalition, especially the United Malays National Organization (UMNO) declined dramatically in the 1999 general election

How to Increase Energy Efficiency in Cognitive Radio Networks

In this paper, we investigate the achievable energy efficiency of cognitive radio networks where two main modes are of interest, namely, spectrum sharing (known as underlay paradigm) and spectrum sensing (or interweave paradigm). In order to improve the energy efficiency, we formulate a new multiobjective optimization problem that jointly maximizes the ergodic capacity and minimizes the average transmission power of the secondary user network while limiting the average interference power imposed on the primary user receiver. The multiobjective optimization will be solved by first transferring it into a single objective problem (SOP), namely, a power minimization problem, by using the ε-constraint method. The formulated SOP will be solved using two different methods. Specifically, the minimum power allocation at the secondary transmitter in a spectrum sharing fading environment are obtained using the iterative search-based solution and augmented Lagrangian approach for single and multiple secondary links, respectively. The significance of having extra side information and also imperfect side information of cross channels at the secondary transmitter are investigated. The minimum power allocations under perfect and imperfect sensing schemes in interweave cognitive radio networks are also found. Our numerical results provide guidelines for the design of future cognitive radio networks

Phytochemicals Analysis and Antioxidant Potential of Hydroalcoholic Extracts of Fresh Fruits of Pistacia atlantica and Pistacia khinjuk

Medicinal plants are known for containing potent antioxidants, primarily due to the presence of phytochemical components with diverse biological properties. In this study, we assessed the chemical constituents and antioxidant potential of Pistacia atlantica and P. khinjuk. The essential oils from P. atlantica and P. khinjuk oleoresin were obtained through hydrodistillation, and their chemical constituents were identified using gas chromatography-mass spectrometry (GC-MS). Additionally, we evaluated the total phenolic and flavonoid contents, total antioxidant activity, and free radical quenching potentials of hydroalcoholic extracts from P. atlantica and P. khinjuk. These assessments were performed using the Folin-Ciocalteu method, aluminum chloride method, phosphomolybdate test, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition assay (Half-maximal inhibitory concentration (IC50 value)), respectively. The results revealed that the major phytochemical components in P. atlantica essential oil were ?-pinene, camphene, ?-pinene, D-limonene, cyclohexene, and careen. Additionally, P. khinjuk essential oil contained ?-pinene, ?-Pinene, trans-verbnol, bicyclo(3.1.1.)heptan, verbenene, camphene, D-limonene, and ?-campholenal. Furthermore, the total phenols and flavonoids content of P. atlantica were higher than those of P. khinjuk. However, the total antioxidant capacity was significantly greater in P. khinjuk than in P. atlantica. The IC50 value (DPPH assay) was also significantly higher in P. khinjuk compared to P. atlantica. Although the essential oils of both plants exhibited antioxidant effects, P. atlantica essential oils demonstrated superior antioxidant effects compared to P. khinjuk. In conclusion, the presence of abundant phytochemical components, such as monoterpenes, was observed in both the plants. These findings suggest that P. atlantica and P. khinjuk generally possess considerable antioxidant activity

The Rampancy of Multiple-Drug Resistant Bacteria Isolated from Surface Water of Satow Waterfall, Bau Sarawak

Antimicrobial resistance (AMR) is universally acknowledged as a serious threat to human health, wellbeing, and prosperity. Many therapeutically important antibiotic resistance genes are thought to have arisen in the environment. Antibiotics are no longer effective in treating infections caused by multi-and pan-resistant bacteria (dubbed "superbugs") that have spread rapidly around the world [1]. Furthermore, AMR bacteria and antimicrobial resistant genes can thrive and proliferate in natural waterbodies because they can act as both recipients and natural reservoirs for the bacteria and genes. Toxic exposure to AMR bacteria and ARGs puts recreationists in danger, reducing their ability to combat illnesses. Considering Satow Waterfall, Bau is a renowned water-based recreational destination, an assessment of their physiochemical water quality characteristics and the prevalence of AMR bacteria was conducted to corroborate the safety of the water. A total of nine water samples were collected at the surface water (0–30 cm depth) of the upstream, midstream, and downstream. The water quality index (WQI) of the sampling stations ranged from 92.60 to 95, classifying the water under Class I. However, the water is microbiologically polluted. During Trip 2, the highest level of coliform was found in the middle stream at 2.59x105 cfu/mL, which is above the regulatory standard set by the Malaysian Department of Environment (DOE). A total of 100 isolated bacteria were subjected to (GTG)5- genomic fingerprinting analysis to evaluate the degree of genetic similarity among the samples and thus enable the selection of appropriate clonal representatives. Fifty-four bacterial isolates were chosen as representatives and identified by 16SrDNA sequencing, which confirmed the existence of 21 bacterial genera as shown in Figure 1. All identified isolates were tested against 15 antibiotics of various classes, namely, streptomycin (S), Kanamycin (K), cefotaxime (CTX), cephalothin (KF), tetracycline (TE), doxycycline (DO), carbenicillin (CAR), sulfamethoxazole (SXT), ofloxacin (OFX), levofloxacin (LEV), erythromycin (E), meropenem (MEM), ertapenem (ETP), vancomycin (VA) and chloramphenicol (C) employing the Clinical and Laboratory Standards Institute (CLSI) protocols. The antibiotic susceptibility test (AST) demonstrated substantial resistance to SXT (41%), E (41%) and CAR (39%), as well as high susceptibility to C (85%), followed by LEV (78%) and OFX (72%). The Multiple Antibiotic Resistance Index (MARI) evaluation demonstrated the MARI varied from 0–0.60, with 33% of the isolates having a MARI greater than 0.20

Evaluation of antibacterial and antifungal activities of Pistacia atlantica and Pistacia khinjuk

Medicinal plants are renowned for their various therapeutic properties, including antibacterial and antifungal activities. This study aimed to investigate the antibacterial and antifungal activities of P. atlantica and P. khinjuk. Hydroalcoholic extracts of P. atlantica and P. khinjuk were prepared to assess their antibacterial and antifungal activities. Standard strains of Bacillus cereus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Klebsiella pneumonia, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Aspergillus flavus were utilized for the evaluation of antibacterial and antifungal activities. The inhibitory effects of the extracts on the growth of bacterial and fungal strains were evaluated using minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) through a 96-well microplate analysis following CLSI guidelines. Our findings revealed that the MICs and MBCs of P. atlantica and P. khinjuk for bacterial strains ranged from 0 to 64 mg/mL. Additionally, the MIC and MFC values for fungal strains ranged from 16 to 64 mg/mL. The results indicated that Pseudomonas aeruginosa and Klebsiella pneumonia were the most sensitive bacterial strains to P. atlantica. Furthermore, Aspergillus flavus was identified as the most sensitive fungal strain to P. atlantica. In conclusion, these findings suggest that P. atlantica and P. khinjuk possess antibacterial and antifungal effects. The paper argues that these plant extracts could be used as a supplementary treatment alongside conventional antibacterial and antifungal drugs

Antiferromagnetic droplet soliton driven by spin current

We demonstrate that a spin current flowing through a nano-contact into a uniaxial antiferromagnet with first- and second-order anisotropy can excite a self-localized dynamic magnetic soliton, known as a spin-wave droplet in ferromagnets. The droplet nucleates at a certain threshold current with the frequency of the N\'eel vector precession laying below the antiferromagnetic resonance. The frequency exhibits nonlinear behavior with the increasing of applied current. At the high value of applied torque, the soliton mode transforms, and the oscillator emits spin waves propagating in the antiferromagnetic layer.Comment: 6 pages, 5 figure

Machine learning-based multi-target regression to effectively predict turning movements at signalized intersections

Effective prediction of turning movement counts at intersections through efficient and accurate methods is essential and needed for various applications. Commonly predictive methods require extensive data collection, calibration, and modeling efforts to estimate turning movements. In this study, three models were proposed to estimate turning movements at signalized intersections using approach volumes. Two sets of data from the United States and Canada were obtained to develop and test the proposed models. Machine learning-based regression models, including random forest regressor (RFR) and multioutput regressor (MOR) in addition to an artificial neural network (ANN) model, were developed and trained to analyze the relationship between approach volumes and corresponding turning movements. Multiple evaluation measurements were utilized to compare the models. All models produced satisfactory results. The RFR regression model outperformed the MOR model. However, the ANN model had the best performance when compared to the other models. The proposed models provide traffic engineers and planners with reliable and fast methods to estimate turning movements. 2022 Tongji University, Tongji University PressThe authors would like to thank the reviewers for their dedicated work and insightful comments and recommendations.Scopu