154 research outputs found
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
When the End Justifies the Means: Raphaël Lemkin and the Shaping of a Popular Discourse on Genocide
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)
Guest editorial introduction to the special issue on “advanced signal processing techniques and telecommunications network infrastructures for smart grid analysis, monitoring, and management”
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
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
Social Aspects of Diabetic Foot: A Scoping Review
Diabetic foot ulcer (DFU) is a severe complication of diabetes mellitus (DM). Patients with DFU have increased mortality and morbidity as well as decreased quality of life (QoL). The present scoping review aims to study the social issues of diabetic foot. Following PRISMA guidelines, the review was conducted in two databases (Scopus and Pubmed) with the use of the following keywords: “social aspects and diabetic foot”, “social characteristics and diabetic foot”, “social issues and diabetic foot”, “demographic profiles and diabetic foot”, “social determinants and diabetic foot”, “social capital and diabetic foot”, “social characteristics and gender and diabetic foot”, “social profiles and diabetic foot”, “social relationships and diabetic foot” and “social risk and diabetic foot”, from July to August 2021. Predetermined exclusion and inclusion criteria were selected. Forty-five studies (quantitative and qualitative) were eligible for inclusion in this review. Gender problems, socioeconomic status, social capital, and medical problems were the most important negative variables for diabetic foot. All the included variables reveal that the social impact of diabetic foot is the most important factor for management and prevention, in terms of aggravation and more, of the diabetic foo
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