NEW APPROACHES FOR VERY SHORT-TERM STEADY-STATE ANALYSIS OF AN ELECTRICAL DISTRIBUTION SYSTEM WITH WIND FARMS

Distribution networks are undergoing radical changes due to the high level of penetration of dispersed generation. Dispersed generation systems require particular attention due to their incorporation of uncertain energy sources, such as wind farms, and due to the impacts that such sources have on the planning and operation of distribution networks. In particular, the foreseeable, extensive use of wind turbine generator units in the future requires that distribution system engineers properly account for their impacts on the system. Many new technical considerations must be addressed, including protection coordination, steady-state analysis, and power quality issues. This paper deals with the very short-term, steady-state analysis of a distribution system with wind farms, for which the time horizon of interest ranges from one hour to a few hours ahead. Several wind-forecasting methods are presented in order to obtain reliable input data for the steady-state analysis. Both deterministic and probabilistic methods were considered and used in performing deterministic and probabilistic load-flow analyses. Numerical applications on a 17-bus, medium-voltage, electrical distribution system with various wind farms connected at different busbars are presented and discusse

A New Ensemble Probabilistic Method for Short-Term Photovoltaic Power Forecasting

The high penetration of photovoltaic (PV) systems led to their growing impact on the planning and operation of actual distribution systems. However, the uncertainties due to the intermittent nature of solar energy complicate these tasks. Therefore, high-quality methods for forecasting the PV power are now essential, and many tools have been developed in order to provide useful and consistent forecasts. This chapter deals with probabilistic forecasting methods of PV system power, since they have recently drawn the attention of researchers as appropriate tools to cope with the unavoidable uncertainties of solar source. A new multi-model probabilistic ensemble is proposed; it properly combines a Bayesian-based and a quantile regression-based probabilistic method as individual predictors. Numerical applications based on actual irradiance data give evidence of the probabilistic performances of the proposed method in terms of both sharpness and calibration

Distributed Energy Resources to Improve the Power Quality and to Reduce Energy Costs of a Hybrid AC/DC Microgrid

This chapter deals with microgrids (μGs), i.e., a group of interconnected loads and distributed energy resources that act as a single controllable entity with respect to the grid. The μGs can be classified into AC and DC μGs depending on the characteristics of the supply voltage, with both solutions characterized by advantages and challenges. Recently, hybrid AC/DC μGs have been developed with the aim to exploit the advantages of both AC and DC solutions. Hybrid μGs require being properly controlled to guarantee their optimal behavior, in both grid-connected and islanding mode. In this chapter, we propose an optimal control strategy for a hybrid μG to be realized in an actual Italian industrial facility. The control strategy operates with the aim to simultaneously minimize the energy costs and to compensate waveform distortions. The key result of the chapter consists in evidencing the technical and economic advantages of the proposed solution by means of real-time simulations of the hybrid μG performed through Matlab/Simulink development tool in the different conditions (grid-connected and islanding mode)

Association between Anthropometric Measurements and Vascular Disease: A Cross Sectional Study

The aim of this article is to assess the most studied anthropometric measurements in a population of patients with vascular disease (VD) such as chronic venous disease (CVD), carotid stenosis (CS), abdominal aortic aneurysm (AAA), and peripheral artery disease (PAD). This is a cross sectional study that recruited consecutive patients with VD (CVD, CS, AAA, PAD) referred to Vascular Surgery Units of two hospitals in the period July 2019–March 2022. Several anthropometric measurements such as height, weight, body mass index (BMI), waist circumference, waist-to-BMI, waist-to-hip ratio (WHR), A Body Shape Index (ABSI), waist-to-stature ratio (WSR) were recorded. In a one-way ANOVA test, no statistical significance for all anthropometric variables were found, but the post hoc analysis performed with Tuckey test, show significant difference for height (p-value: 0.017) and WHR (p-value: 0.005) when compared AAA and CS groups with CVD, respectively. Height seems positively associated with AAA, and negatively associated with CVD. WHR seems positively associated with CS and negatively associated with CVD. Further studies are needed to clarify the role of anthropometric measures as independent predictors for vascular disease onset, progression, and response to treatments

Adding immersive virtual reality laboratory simulations to traditional teaching methods enhances biotechnology learning outcomes

Immersive virtual reality (VR) simulations are increasingly being used in diverse educational and training contexts to supplement traditional learning methods. The high versatility of virtual laboratories allows students to take advantage of many benefits, like experiencing dangerous reactions, time-consuming protocols, or expensive equipment without the necessity of a real science laboratory. However, little research is currently available to support the efficacy and efficiency of this new learning tool. In this context, the main objective of this study was to assess the influence of biotechnology training by using immersive VR technologies on the student’s motivational and learning outcomes as compared with learning with conventional methods only. To this aim we tested two diverse strategies, respectively VR simulations were used in place of or in addition to the teacher’s introductory lesson of a hands-on laboratory experience. Aligned questionaries were administered before and after the proposed activities to assess theoretical knowledge, self-efficacy, interest in biotechnology, and engagement of the participants. We found that when the introductory lesson to a biotechnology hands-on laboratory is replaced with an equivalent immersive VR simulation, the student’s learning outcomes are lower with respect to the traditional approach. On the contrary, when VR simulations are integrated as an additional tool to the existing learning methods, higher learning outcomes were observed demonstrating a deeper understanding of the learning contents. Furthermore, our study showed that learning with immersive VR simulations motivates students more than the traditional methods, thus, using this new technology in addition to the existing educational methods in biotechnology could be considered as a win-win strategy to raise the attention of the students while increasing the learning outcomes

Treatment of de novo femoro-popliteal lesions with a new Drug Coated Balloon: early experience of a single Center in the first 50 patients

Angioplasty with drug-coated balloon (DCB) is an emerging and reliable method for the treatment of femoro-popliteal lesions. We report our experience with the Stellarex™ DCB in the first 50 patients. Methods - From July 2015 to November 2017, 50 patients (41 M, 9F), medium age (64 ± 7.4 year) were subject to 33 angioplasties (PTAs) for femoro-popliteal lesions with a paclitaxel-coated balloon (Stellarex™). Based upon clinical data sixteen patients had severe claudication (56% - Rutherford class 3); ten patients suffered from ischemic rest pain (34% - Rutherford class 4); and five presented minor tissue loss (10% - Rutherford class 5). 42% of patients showed femoro-popliteal lesion TASC-II B, and 58% presented lesions pertaining to TASC-II C. Results - Immediate technical success was 100% without perioperative complications. Primary patency rate was 94% at twelve months. In three cases restenosis (6%) was detected within a year from procedure, and a further PTA DCB was performed with primary assisted patency rates of 100% at twelve months. Two patients underwent major lower limb amputation. Three patients died during follow-up and one patient was lost at follow-up. Conclusion - DCB angioplasty with Stellarex™ is a viable alternative to traditional endovascular procedures proving satisfactory primary patency rates at twelve months. Based on our experience, treatment with DCB is a first choice technique for non-complex de novo lesions of the femoro – popliteal tract

Wound Care Self-Efficacy Assessment of Italian Registered Nurses and Wound Care Education in Italian Nursing Education System: A Cross-Sectional Study

Wounds are a major public health challenge for nurses, and poor wound care has important implications for patients and health care systems. The aim of this study is to assess the Italian registered nurses’ (RNs) perception in the area of wound care, regarding their knowledge, tasks of care delivery, wound management, values, and attitudes, exploring also the previous specific education received during nursing education. An observational online web-based survey was used to assess learning goals and content for wound care education in undergraduate nursing education and the skills and level of self-efficacy in this area during clinical practice. The data were collected between April and May 2022. A total of 210 RNs were interviewed and divided into five national geographic areas. Northwestern RNs showed a better education about the wound care area during university courses: the rate of RNs that did not receive any training in the wound care area was lower than in other Italian geographical areas. Southern RNs presented a better knowledge about factors that expose the wound to becoming chronic, wound drains care, and the ability to assess diabetic foot. This study showed that, in Italy, education in wound care among nursing students is relatively poor, and many skills are achieved during an RN’s career in an empirical way