PSC

Objective: To evaluate the incidence of deep vein thrombosis (DVT) in a rural area of Iceland and the prevalence of post thrombotic syndrome (PTS) in patients with history of DVT. Material and methods: A retrospective study where all phlebographies (n=177) performed at the department of radiology, Akureyri Hospital, during the period 1975-1990 were re-evaluated. Information on patients with DVT (n=32) were taken both from the Hospital and the Health Center records. All patients alive in December 1997 (n=17), 10.5 years after the diagnosis of DVT were interviewed concerning PTS. Results: The incidence of DVT during the period 1975-1990 was 1/10,000 inhabitants/year, but was 2.3/10,000/ year for the period 1986-1996. The mean age was 60 years and 62% of the patients were males. In 37.5% cases DVT was localized below the popliteal vein, in another 34.4% below the inguinal ligament and 28.1% of the thrombosis extended to the pelvic vein system. Of the patients 23.3% had a history of mal...

Every year a substantial number of children are affected by natural disasters worldwide. However, data are scarce on long-term psychological impact of natural disasters on children's health. Identifying risk factors and outcomes associated with the long-term sequelae of posttraumatic stress disorder (PTSD) can provide a gateway to recovery as well as enhancement of preventive measures. Among childhood avalanche survivors, we aimed to investigate risk factors for PTSD symptoms and the relationship between socioeconomic status (SES) and PTSD symptoms in adulthood. Childhood survivors (aged 2-19 at the time of exposure) of two avalanches were identified through nationwide registers 16 years later. The Posttraumatic Diagnostic Scale was used to assess current PTSD symptoms. One-way ANOVA was used to explore PTSD symptoms by background and trauma-specific factors, as well as associations with current SES. Predictors of PTSD symptoms were examined by multivariable regression analysis....

In recent years, the European Space Agency (ESA) has seen a gradual expansion in its mission to now include ensuring space security. Such a change may have been favoured by the evolving needs of the EU, which is one of the ESA’s main partners and has become more and more concerned with the security and resilience of its space assets, as well as increasingly relevant in the ESA’s funding. Accordingly, ESA might be transitioning from a purely civilian and scientific organization to an institution entrusted with developing the security of space facilities against natural hazards and collision with man-made objects, both deliberate and unintended. While ESA’s new ‘defence for space’ approach has surely increased the institution’s military relevance, it is still unclear whether such a transition will benefit or impede European defence. On the one hand, profiting from the consolidated technical expertise of the ESA could afford European the armed forces the opportunity to increasingly rely on high-quality space facilities. On the other hand, institutional overlap and ensuring coordination with other EU bodies could present serious challenges, ones which could eventually hamper the efficacy of European space assets for military activities.

Perovskite solar cells (PSCs) have now achieved efficiencies in excess of 22%, but very little is known about their long-term stability under thermal stress. So far, stability reports have hinted at the importance of substituting the organic components, but little attention has been given to the metal contact. We investigated the stability of state-of-the-art PSCs with efficiencies exceeding 20%. Remarkably, we found that exposing PSCs to a temperature of 70 °C is enough to induce gold migration through the hole-transporting layer (HTL), spiro-MeOTAD, and into the perovskite material, which in turn severely affects the device performance metrics under working conditions. Importantly, we found that the main cause of irreversible degradation is not due to decomposition of the organic and hybrid perovskite layers. By introducing a Cr metal interlayer between the HTL and gold electrode, high-temperature-induced irreversible long-term losses are avoided. This key finding is essential in ...

In free market conditions, if public passenger transport services are commercially unprofitable, there will be no interest for transport companies to perform them. However, directly because of the citizens’ interests, on the one hand, and indirectly because of the economy, passenger public transport services have become of a general public interest. The authorities must prepare appropriate legal fair market conditions, based on which public transport will be subsidized and conducted. In order to achieve that, for the mutual benefit of the public, users and transport companies, it is necessary that the right Public Service Obligation Model (PSO model or in some literature PCS—Public Service Compensation) be defined. Within this study, the optimal approach to assigning a PSC contract to transport companies for performing the PSO in integrated and regular public passenger transport systems is determined. A novel model, presented in this paper, can help national, regional and local auth...

In free market conditions, if public passenger transport services are commercially unprofitable, there will be no interest for transport companies to perform them. However, directly because of the citizens’ interests, on the one hand, and indirectly because of the economy, passenger public transport services have become of a general public interest. The authorities must prepare appropriate legal fair market conditions, based on which public transport will be subsidized and conducted. In order to achieve that, for the mutual benefit of the public, users and transport companies, it is necessary that the right Public Service Obligation Model (PSO model or in some literature PCS—Public Service Compensation) be defined. Within this study, the optimal approach to assigning a PSC contract to transport companies for performing the PSO in integrated and regular public passenger transport systems is determined. A novel model, presented in this paper, can help national, regional and local auth...

The complexity of conflicts on the African continent has left the African Union (AU) at the center of addressing the peace and security challenges on the continent. Peacekeeping has been a prevailing subject of the African Union for decades thereby assigning this organization the steering wheel for major operations in the region. This article takes into viewpoint an assessment of the AU peacekeeping operations, amidst its challenges and politics within the context of continental peace and security. Furthermore, it seeks to probe into the effectiveness of the Organization as a lead regional security actor in terms of its peacekeeping operations with preference given to the missions in Somalia and Sudan

Kwame Nkrumah’s Pan-African dream of establishing African High Command meant to protect the newly created postcolonial African states in 1961 did not borne fruit because most of African states opposed and rejected it due to the perceived threat it posed on their sovereignty. However, the failure of the Organization of African Unity (OAU) dealing with the prolonged conflicts in the continent, the horrific Rwandan genocide incident of 1994, and the belief that without peace, development and prosperity could not take root in Africa provided reasons for the shift from the OAU to the African Union (AU) in 2001 and revived Nkrumah’s idea of African wide security force, which eventually brought to existence the African Standby Force (ASF) in 2002. Since then the ASF has achieved some successes in responding timely to conflicts in Africa despite the fact that its efforts were largely concealed by various challenges that it faced. Research works that have so far been done in the subject lack...

Limited data exist on the association between trauma and sleep across developmental stages, particularly trauma experienced in childhood and sleep in adulthood. We assessed sleep quality across the developmental spectrum among avalanche survivors 16 years after exposure as compared to a matched comparison cohort. Participants were survivors of two avalanche-affected towns (n = 286) and inhabitants of non-exposed towns (n = 357). Symptoms were assessed with respect to the survivors' developmental stage at the time of the disaster: childhood (2-12), adolescence (13-19), young adult (20-39), and adult (≥ 40). The Posttraumatic Diagnostic Scale, Pittsburgh Sleep Quality Index and Pittsburgh Sleep Quality Index PTSD Addendum were used. Overall PTSD symptoms were not associated with avalanche exposure in any age groups under study. However, survivors who were children at the time of the disaster were 2.58 times (95% CI 1.33-5.01) more likely to have PTSD-related sleep disturbances (PS...

Every year a substantial number of children are affected by natural disasters worldwide. However, data are scarce on long-term psychological impact of natural disasters on children's health. Identifying risk factors and outcomes associated with the long-term sequelae of posttraumatic stress disorder (PTSD) can provide a gateway to recovery as well as enhancement of preventive measures. Among childhood avalanche survivors, we aimed to investigate risk factors for PTSD symptoms and the relationship between socioeconomic status (SES) and PTSD symptoms in adulthood. Childhood survivors (aged 2-19 at the time of exposure) of two avalanches were identified through nationwide registers 16 years later. The Posttraumatic Diagnostic Scale was used to assess current PTSD symptoms. One-way ANOVA was used to explore PTSD symptoms by background and trauma-specific factors, as well as associations with current SES. Predictors of PTSD symptoms were examined by multivariable regression analysis....

There are various types of Multilevel Converters (MCs) in addition to various types of modulation techniques for these types of MCs; the challenges in selecting the best one of them with regard to the amount of the required of components, and its harmonics content. So, a comparison study among these types has been done in this paper. For comparison study, the simulation of seven level of two popular topologies of MCs: Neutral Point Clamped (NPC) converter, and Cascaded-MCs were carried out with Matlab/Simulink software program. These converters are used to drive a single phase capacitor start motor drive. Multicarrier modulation control techniques are used for controlling the MCs; these techniques involve two main type: Level Shifted Carrier (LSC), and Phase Shifted Carrier (PSC). The comparison is made with respect to the performance factors as, the amplitude of  the Total Harmonic Distortion (THD), and the DC-bus utilization performance which measured by Root Mean Square of the ou...

In free market conditions, if public passenger transport services are commercially unprofitable, there will be no interest for transport companies to perform them. However, directly because of the citizens’ interests, on the one hand, and indirectly because of the economy, passenger public transport services have become of a general public interest. The authorities must prepare appropriate legal fair market conditions, based on which public transport will be subsidized and conducted. In order to achieve that, for the mutual benefit of the public, users and transport companies, it is necessary that the right Public Service Obligation Model (PSO model or in some literature PCS—Public Service Compensation) be defined. Within this study, the optimal approach to assigning a PSC contract to transport companies for performing the PSO in integrated and regular public passenger transport systems is determined. A novel model, presented in this paper, can help national, regional and local auth...

This paper identifies the partial shading problem of a PV module using the one-diode model and simulating the characteristics exhibiting multiple-peak power output condition that is similar to a PV array. A modified particle swarm optimization (PSO) algorithm based on the suggested search-agent deployment, retracking condition, and multicore operation is proposed in order to continuously locate the global maximum power point for the PV system. Partial shading simulation results for up to 16 modules in series/parallel formats are presented. A distributed PV system consisting of up to 8 a-silicon thin film PV panels and also having a dedicated DC/DC buck converter on each of the modules is tested. The converter reaches its steady state voltage output in 10 ms. However for MPPT operation, voltage, and current measurement interval is set to 20 ms to avoid unnecessary noise from the entire electric circuit. Based on the simulation and experiment results, each core of the proposed PSO ope...

Low circulating levels of total 25-hydroxyvitamin D (25(OH)D) have been associated with an increased risk of adverse effects after cardiac surgery. The metabolites, 25(OH)D2 and 25(OH)D3, provide a good index of vitamin D status. In this study, we examined the association between preoperative plasma levels of total 25(OH)D, 25(OH)D2 and 25(OH)D3 and the risk of postoperative atrial fibrillation (POAF) following open heart surgery. The levels of plasma 25(OH)D2 and 25(OH)D3 in 118 patients, who underwent coronary artery bypass grafting and/or valvular surgery, were measured immediately prior to surgery and on postoperative day 3 by liquid chromatography–tandem mass spectrometry. Patients who developed POAF had higher median plasma levels of 25(OH)D2 than those who remained in sinus rhythm (SR) (P = 0·003), but no significant difference was noted in levels of 25(OH)D3 or total 25(OH)D between the two groups (P > 0·05). By univariate analysis, patients with total 25(OH)D and 25(OH)D...

Optimization of the interface between the electron transport layer (ETL) and the hybrid perovskite is crucial to achieve high-performance perovskite solar cell (PSC) devices. Fullerene-based compounds have attracted attention as modifiers on the surface properties of TiO2, the archetypal ETL in regular n-i-p PSCs. However, the partial solubility of fullerenes in the aprotic solvents used for perovskite deposition hinders its application to low-temperature solution-processed PSCs. In this work, we introduce a new method for fullerene modification of TiO2 layers derived from nanoparticles (NPs) inks. Atomic force microscopy characterization reveals that the resulting ETL is a network of TiO2-NPs interconnected by fullerenes. Interestingly, this surface modification enhances the bottom interface of the perovskite by improving the charge transfer as well as the top perovskite interface by reducing surface trap states enhancing the contact with the p-type buffer layer. As a result, rigid...

High power capacity and reliability are characteristics of multilevel inverters. The using a collection of DC sources can produce a terminal voltage that is very close to sinusoidal. The power quality can be improved by adding more levels, but this makes the control system more complicated and expensive. The number of power components in a multilevel inverter has been studied for decades. So, research needs to be done on multilevel inverter configurations to find ways to add levels with fewer power switches than with traditional topologies and those that have already been proposed. In this research, a new power-efficient arrangement of a flying-capacitor inverter is introduced. In order to illustrate the suggested topology, a sevenlevel multilevel inverter is constructed and demonstrated in a simplified form. Fewer power components, including power switches, capacitors, and gate driver circuits, are required in this topology than in other topologies described in the recent literature, which is one of its main advantages. The improvement mentioned above can be seen in the way this topology works, which is shown by the characteristics of the circuit. MATLAB/Simulink R2021a is used to simulate and verify the circuit to ensure the proposed topology is correct.