: QKD integration into traditional telecommunication networks is anticipated in the upcoming decades in order to maintain adequate levels of communication security. QKD establishes ITS (Information-Theoretic secure) symmetric keys between the two parties, which they may use to sustain secure flow of data even in the post-quantum era. Since QKD-keys are a valuable and scarce resource, they must be carefully maintained. This paper investigates DoS attacks on actual QKD equipment, in which an adversary with access to QKD services depletes the reserves of QKD-keys maintained at the KMS system. As a result, safety precautions are proposed in order to prevent this scenario and maintain operational QKD service.
: Free Space Optics (FSO) represent a promising technology for secure communications in several types of architectures: from Quantum Key Distribution Networks (QKDNs) to satellite communications. In this paper, in particular, we take into account terrestrial point-to-point laser communications and evaluate the performance in terms of Signal-to-Noise Ratio (SNR) and Bit Error Rate (BER), taking into account different scenarios, that can reflect real situations in which long distances can be reached in a secure way, guaranteeing an acceptable level of BER. So, after a huge campaign of simulations, we would like to let the scientific community know which are the theoretical limits that such kind of communications can reach. We take into account standard telescopes parameters (available today in the market), while configuring several real situations, in function of, for example, bit-rate, visibility, link distance, etc. A brief survey of the existing works is given, then a clearer performance evaluation of terrestrial FSO links is proposed.
Background: Consuming a diet rich in natural foods that include oilseed products containing bioactive compounds and a diverse array of fatty acids is not just a dietary choice; it is a critical element of maintaining human health. Objective: This paper aims to review the current state of knowledge on minor bioactive compounds in vegetable cold pressed oils, these are substances that are found in small amounts in vegetable cold pressed oils. Methods: Intended as an indispensable resource, this review is designed to empower medical professionals in the fields of integrative medicine, nutrition, and dietetics. Results and Discussion: Cold-pressed oils extracted from various plant sources have emerged as vital allies in the battle against inflammation-related diseases, offering a versatile range of valuable compounds. These compounds contribute to the oils' multifaceted properties, which encompass potent anti-inflammatory, antioxidant, and anticancer effects, greatly enhancing their nutritional significance. This brief review delves deep into the intricate composition of cold-pressed oils, with a specific focus on the often overlooked but highly influential minor bioactive compounds, including phytosterols, phospholipids, tocols, phenols, squalene and pigments. Intended as an indispensable resource, this review is designed to empower medical professionals in the fields of integrative medicine, nutrition, and dietetics. It equips them with a wealth of knowledge to guide consumers in making informed choices when incorporating cold-pressed oils into their dietary plans, tailored to their individual health needs.. Conclusion: This paper highlights the importance of cold-pressed oils as a source of various minor bioactive compounds that have the potential to promote human health and prevent or manage a range of diseases. The findings presented in this paper serve as a valuable resource for medical professionals in the field of integrative medicine, nutrition, and dietetics, as well as for consumers looking to make informed choices about their dietary and health needs.
Background: Radiotherapy is one of the primary treatment options in cancer management, together with surgery and chemotherapy. Radiation therapy is technologically complex discipline involving professionals with various specialties, and using high energy radiation in treatment of wide range of different cancer types. Technical complexity, increasing number of patients, large workload, and delivery of radiation therapy treatment with lack of human, technical and financial resources in low and middle income countries creates environment with great potential to develop incidents. Emerging need of modern radiation therapy is to develop preventive approach to risk management i to improve the patient safety. Objective: The objective of this research is to identify and assess risk associated with radiation therapy practice in Bosnia and Herzegovina. Methods: An anonymous, voluntary electronic on-line radiation therapy incident reporting system (IRS) was created. IRS consists of four sections containing questions about working environment, incident occurrence, root causes and contributing factors, and incident severity assessment. Data collected using IRS were used to create taxonomy of incidents in radiation therapy. Risk assessment was made using Risk Matrix method. Research was made using the data collected from first 60 incidents reported to IRS. Results: Based on probability and frequency of incident occurrence and severity of consequences, it was assessed that 41.7% of incidents had low risk level (L), 50% of incidents had moderate risk level (M), and 8.3% of incidents had high risk level (H). Radiation therapy risk profile based on risk assessment results clearly shows that incidents with low frequency, low occurrence probability, but high consequences severity level have highest level of risk. Conclusion: The results of this research confirm that the electronic on-line radiation therapy IRS allows the identification and classification of the most significant risk factors in radiotherapy and prevention of serious incidents occurrence.
The energy transition towards increased electric power production from renewable energy (RE) resources creates new challenges to ensure the stability of power grids. In conventional power grids voltage fluctuations can be controlled locally. Here, it is explored whether this may be changed by the energy transition. It is well established that the increase of RE resources in power grids increases the amplitude of frequency deviations and the velocity with which these deviations spread throughout the power grid. However, its effect on voltage dynamics and propagation has not been systematically studied. Here, a systematic study is carried out of the transients of voltage amplitude, phase and frequency deviations due to local contingencies in dependence on system inertia, heterogeneity and topology. The 3rd order dynamic power grid model is studied numerically and analytically and compared with real grid simulations for the Nigerian (330 kV) power grid and other grid models, using DigSILENT PowerFactory software. A quantitative analysis of the parametric dependence of the velocity with which a disturbance propagates throughout the grid and of the period of oscillations of the frequency and voltage transients is provided. Beating patterns are found in the transients and are identified as footprints of the location of the fault bus, as caused by multiple reflections of propagating disturbances from the grid boundary. These may result in interarea oscillations. It is confirmed that voltage deviations remain local for realistic ranges of parameters, but that it can propagate by literally surfing on the frequency deviation wave. However, it is found that this no longer holds true when the electrical power in the grid approaches its critical value beyond which no stationary solution exists. Furthermore, time dependent second moments of the geodesic distance weighted with frequency deviations $S_{\delta \omega }(t)$ and voltage deviations $S_{\delta V}(t)$ , respectively are evaluated, confirming a ballistic disturbance propagation in homogeneous model grids. However, in real grid simulations, a linear time dependence of $S(t)$ is observed, indicating a diffusive propagation due to multiple scattering from the inhomogeneities in these power grids.
Application of a discrete time (DT) sliding mode controller (SMC) in the control structure of the primary controller of a three-phase LCL grid inverter is presented. The design of the inverter side current control loop is performed using a DT linear model of the grid inverter with LCL filter at output terminals. The DT quasi-sliding mode control was used due to its robustness to external and parametric disturbances. Additionally, in order to improve disturbance compensation, a disturbance compensator is also implemented. Also, a specific anti-windup mechanism has been implemented in the structure of the controller to prevent large overshoots in the inverter response in case of random disturbances of grid voltages, or sudden changes in the commanded power. The control of the grid inverter is realized in the reference system synchronized with the voltage of the power grid. The development of the digitally realized control subsystem is presented in detail, starting from theoretical considerations, through computer simulations to experimental tests. The experimental results confirm good static and dynamic performance.
Although there is clear dose-dependence of pulmonary toxicity caused by inhalation of normobaric oxygen in animal studies, the threshold of toxicity in humans remains largely unknown. The aim of this systematic review of published clinical studies was to establish threshold in terms of total oxygen dose administered under normal pressure by inhalation that causes first clinical signs of toxicity. MEDLINE, EBSCO, The Cochrane Central Register of Controlled Trials (Central), SCIndeks, Scopus, Google Scholar, and ClinicalTrials.gov were searched from their foundation to April 2022. The systematic review was performed according to the pre-registered protocol at PROSPERO. The studies were included if describing toxic effects of normobaric oxygen therapy in humans. In total 11 human studies of poor quality were found, with either experimental or observational design. In none of the analyzed studies did oxygen therapy cause toxic effects on the respiratory tract if the concentration of oxygen in the inhaled air was below 50%, regardless of the rate of administration. The toxic consequences of inhaling oxygen at a concentration of more than 50% occurred only after oxygen was administered for more than 6 hours, at a rate of more than 7 L/min, and were mainly reflected in inflammation of the tracheobronchial mucosa, with epithelial erosions. Normobaric oxygen therapy can have toxic effects in humans if the oxygen concentration in the inhaled air is higher than 50%, if the administration rate is above 7 L/min, and if the application lasts at least 6 hours.
The primary objective of this research paper is to investigate the potential impact of emergency remote teaching on the academic performance of undergraduate students, while also assessing the consistency of academic outcomes across various courses during the emergency transition to distance learning. The research methodology involves the collection of students' accomplishments and course passing rates spanning four consecutive academic years, from 2018/2019 to 2021/2022. The study identifies three distinct teaching environments: traditional, distance learning, and hybrid. The academic year 2018/2019 is designated as a pre-pandemic reference point. The subsequent years mark a transition from distance learning to a hybrid teaching model and a return to the traditional in-class environment. The analytical framework includes descriptive and correlation analyses, supplemented by an analysis of variance to derive meaningful insights. It is essential to highlight that the results obtained are further validated by the passing rates for the academic year 2022/2023, reinforcing the contemporary relevance and credibility of the research findings.
This paper investigates the absolute and conditional convergence process of the Western Balkan states toward the EU-27+1. The analyzed period is 2004–2018; therefore, we include the United Kingdom in the analysis. To test the effects of the 2008/2009 financial crisis on the absolute and conditional convergence process, we include three subperiods in this research: the precrisis period, the crisis period
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