149 research outputs found

    Controllable magnon-induced transparency in a ferromagnetic material via cross- and self-Kerr effects

    Full text link
    Nonlinear interactions between optical fields and magnetic modes in cavity magnonics constitute a rich source of various nontrivial effects in optics and quantum information processing. In cavity magnonics, the nonlinear cross-Kerr effect, which shifts the cavity's central frequency when a magnetic material is pumped, causes the system to exhibit both Kittle and magnetostatic modes. Here, we propose a new scheme for the investigation of probe fields transmission profiles in cavity magnonic systems composed of a microwave cavity and a ferromagnetic material (Yttrium iron garnet sphere). We report single-to-double magnon-induced transparency (MIT) dips and a sharp magnon-induced absorption (MIA) peak, and demonstrate how nonlinear cross- and self-Kerr interactions can significantly enhance or suppress these phenomena. It is observed that the splitting of the MIT window occurs when we incorporate magnon-magnon modes coupling, which helps introducing a new degree of freedom to light-matter interaction problems. Moreover, we investigate the propagation of group delay in the vicinity of transparency and demonstrate how a sharp dip allows the realization of slow light for a longer period of time. We found that both the cavity-Kittle and magnon-magnon modes coupling parameters influence the propagation of group delay, which demonstrates how subluminal-to-superluminal (and vice versa) propagation phenomena may occur and transform. These findings could pave the way for future research into nonlinear effects with novel applications in cavity magnonics devices, which might be exploited for several applications such as quantum computing devices and quantum memories

    A Social Custom “Vani”: Introduction And Critical Analysis

    Get PDF
    This paper reflects an introduction and critical analysis of a custom called Vani. It is widely practiced with diverse names in different areas of Pakistan. This ancient tradition is tied to blood feuds among the various tribes and clans, where the females are forcibly married to the members of different tribes for the dispute settlement. Habitually Vani is affected in the cases of murder, kidnapping and robbery. Inequality/discrimination, law disregard, poor education, poverty, landlord system etc. are fundamental reasons for existence of such type norms. It has become an evil of the society. This is an un-Islamic practice as Islam does not allow a forced marriage. Having different comprehensive laws about every clash Islam has no example/direction to give Vani to settle a heated discussion. It is necessary only to awake the heartfelt public about such type of customs and to allocate their influence to stop it

    Detection and Localization of Firearm Carriers in Complex Scenes for Improved Safety Measures

    Full text link
    Detecting firearms and accurately localizing individuals carrying them in images or videos is of paramount importance in security, surveillance, and content customization. However, this task presents significant challenges in complex environments due to clutter and the diverse shapes of firearms. To address this problem, we propose a novel approach that leverages human-firearm interaction information, which provides valuable clues for localizing firearm carriers. Our approach incorporates an attention mechanism that effectively distinguishes humans and firearms from the background by focusing on relevant areas. Additionally, we introduce a saliency-driven locality-preserving constraint to learn essential features while preserving foreground information in the input image. By combining these components, our approach achieves exceptional results on a newly proposed dataset. To handle inputs of varying sizes, we pass paired human-firearm instances with attention masks as channels through a deep network for feature computation, utilizing an adaptive average pooling layer. We extensively evaluate our approach against existing methods in human-object interaction detection and achieve significant results (AP=77.8\%) compared to the baseline approach (AP=63.1\%). This demonstrates the effectiveness of leveraging attention mechanisms and saliency-driven locality preservation for accurate human-firearm interaction detection. Our findings contribute to advancing the fields of security and surveillance, enabling more efficient firearm localization and identification in diverse scenarios.Comment: This paper is accepted in IEEE Transactions on Computational Social System

    Nitrate and nitrogen oxides: sources, health effects and their remediation

    Get PDF
    Increased use of nitrogenous (N) fertilizers in agriculture has significantly altered the global N-cycle because they release nitrogenous gases of environmental concerns. The emission of nitrous oxide (N2O) contributes to the global greenhouse gas accumulation and the stratospheric ozone depletion. In addition, it causes nitrate leaching problem deteriorating ground water quality. The nitrate toxicity has been reported in a number of studies showing the health hazards like methemoglobinemia in infants and is a potent cause of cancer. Despite these evident negative environmental as well as health impacts, consumption of N fertilizer cannot be reduced in view of the food security for the teeming growing world population. Various agronomic and genetic modifications have been practiced to tackle this problem. Some agronomic techniques adopted include split application of N, use of slow-release fertilizers, nitrification inhibitors and encouraging the use of organic manure over chemical fertilizers. As a matter of fact, the use of chemical means to remediate nitrate from the environment is very difficult and costly. Particularly, removal of nitrate from water is difficult task because it is chemically non-reactive in dilute aqueous solutions. Hence, the use of biological means for nitrate remediation offers a promising strategy to minimize the ill effects of nitrates and nitrites. One of the important goals to reduce N-fertilizer application can be effectively achieved by choosing N-efficient genotypes. This will ensure the optimum uptake of applied N in a balanced manner and exploring the molecular mechanisms for their uptake as well as metabolism in assimilatory pathways. The objectives of this paper are to evaluate the interrelations which exist in the terrestrial ecosystems between the plant type and characteristics of nutrient uptake and analyze the global consumption and demand for fertilizer nitrogen in relation to cereal production, evaluate the various methods used to determine nitrogen use efficincy (NUE), determine NUE for the major cereals grown across large agroclimatic regions, determine the key factors that control NUE, and finally analyze various strategies available to improve the use efficiency of fertilizer nitrogen

    A CROSS-SECTIONAL RESEARCH TO EVALUATE THE AWARENESS AND KNOWLEDGE OF LHVs ABOUT THE WORKING OF RESUSCITATION

    Get PDF
    Objective: For evaluation of the midwives and lady health visitor’s knowledge about neonatal resuscitation working at primary healthcare facilities. Methods: In September – October 2018, a cross-sectional survey was carried out at Services Hospital, Lahore comprising on the midwives and lady health visitors at primary level healthcare facilities. The data was assembled by using a close-ended questionnaire. Results: Out of 103 health workers interviewed, 49% were midwives and 54% were midwives. Overall, 71% of health workers were trained for neonatal resuscitation, while 32% were not formally trained. Arrangements for basic neonatal resuscitative were available at all the 54 (100%) basic health units and 7 (100%) rural health centres. Basic neonatal care knowledge was found appropriate, but midwives have the poor knowledge on the subject as only 24 (49%) answered correctly. Conclusion: Regular in-service training of midwives and lady health visitors is required concerning Basic Neonatal Resuscitation. Keywords: Knowledge, Neonatal resuscitation, Primary healthcare, Health workers, Pakistan

    The evaluation of hepatocellular carcinoma with biphasic contrast enhanced helical CT scan

    Get PDF
    Objective: To evaluate the role of biphasic contrast-enhanced helical CT including Hepatic Arterial Phase (HAP) imaging with Portal Venous Phase (PVP) imaging, in the detection and characterization of hepatocellular carcinomas.Methods: The study included 40 patients (M = 26, F = 14) with histopathologically proven HCC. Age range was between 30-85 years (mean = 55) by following consecutive patients with cirrhosis in whom Hepatocellular carcinoma was diagnosed or suspected either by raised serum a (alpha)-fetoprotein level or Ultrasound.Results: Biphasic contrast-enhanced examination revealed a total of 85 lesions in these 40 patients, out of which 13 were unifocal, 12 showed a dominant mass with satellite lesions, 2 showed cluster of contiguous nodules and 13 were multifocal HCCs. Mean diameter was 3.1 cm, ranging from 0.8 to 14 cm. On HAP imaging 85% were detected. (hyperattenuating = 69, hypoattenuating = 3) while on PVP imaging detectibility was only 48% (hyperattenuating = 2, hypoattenuating = 39). Hence detectibility was significantly (p = 0.008) superior in HAP as compared to PVP imaging. In 7 patients (17%) tumor was visible only on HAP images. Venous invasion was present in 12 patients (30%) while arterio-portal shunting was seen in 5 patients (13%).CONCLUSION: Biphasic contrast enhanced helical CT is a useful method in detection and characterization of HCC

    Control and Protection of MMC-Based HVDC Systems: A Review

    Get PDF
    The voltage source converter (VSC) based HVDC (high voltage direct current system) offers the possibility to integrate other renewable energy sources (RES) into the electrical grid, and allows power flow reversal capability. These appealing features of VSC technology led to the further development of multi-terminal direct current (MTDC) systems. MTDC grids provide the possibility of interconnection between conventional power systems and other large-scale offshore sources like wind and solar systems. The modular multilevel converter (MMC) has become a popular technology in the development of the VSC-MTDC system due to its salient features such as modularity and scalability. Although, the employment of MMC converter in the MTDC system improves the overall system performance. However, there are some technical challenges related to its operation, control, modeling and protection that need to be addressed. This paper mainly provides a comprehensive review and investigation of the control and protection of the MMC-based MTDC system. In addition, the issues and challenges associated with the development of the MMC-MTDC system have been discussed in this paper. It majorly covers the control schemes that provide the AC system support and state-of-the-art relaying algorithm/ dc fault detection and location algorithms. Different types of dc fault detection and location algorithms presented in the literature have been reviewed, such as local measurement-based, communication-based, traveling wave-based and artificial intelligence-based. Characteristics of the protection techniques are compared and analyzed in terms of various scenarios such as implementation in CBs, system configuration, selectivity, and robustness. Finally, future challenges and issues regarding the development of the MTDC system have been discussed in detail
    corecore