Safety issues in PV systems: design choices for a secure fault detection and for preventing fire risk

Photovoltaic systems have played a key role over the last decade in the evolution of the electricity sector. In terms of safety design, it's important to consider that a PV plant constitutes a special system of generation, where the Direct Current (DC) presence results in changes to the technical rules. Moreover, if certain electrical faults occur, the plant is a possible source of fire. Choices regarding the grounding of the generator and its protection devices are fundamental for a design that evaluates fire risk. The subject of the article is the analysis of the relation between electrical phenomena in PV systems and the fire risk related to ensuring appropriate fault detection by the electrical protection system. A description of a grid-connected PV system is followed firstly by a comparison of the design solutions provided by international Standards, and secondly by an analysis of electrical phenomena which may trigger a fire. A study of two existing PV systems, where electrical faults have resulted in fires, is then presented. The study highlights the importance of checking all possible failure modes in a PV system design phase, to assess fire risk in advance. Some guidelines for the mitigation of electrical faults that may result in a fire are finally provided

Efficacy of tigecycline for the treatment of complicated intraabdominal infections in real-life clinical practice from five european observational studies

Objectives: Tigecycline is a broad-spectrum antibiotic approved for the treatment of complicated intra-abdominal infections (cIAIs). The efficacy of tigecycline when administered as monotherapy or in combination with other antibacterials in the treatment of cIAIs in routine clinical practice is described. Patients and methods: Individual patient-level data were pooled from five European observational studies (July 2006 to October 2011). Results: A total of 785 cIAI patients who received tigecycline were included (mean age 63.1+14.0 years). Of these, 56.6% were in intensive care units, 65.6% acquired their infection in hospital, 88.1% had at least one comorbidity and 65.7% had secondary peritonitis. The mean Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA) scores at the beginning of treatment were 16.9+7.6 (n=614) and 7.0+4.2 (n=108), respectively, indicating high disease severity. Escherichia coli (41.8%), Enterococcus faecium (40.1%) and Enterococcus faecalis (21.1%) were the most frequently isolated pathogens; 49.1% of infections were polymicrobial and 17.5% were due to resistant pathogens. Overall, 54.8% (n=430) received tigecycline as monotherapy and 45.2% (n=355) as combination therapy for a mean duration of 10.6 days. Clinical response rates at the end of treatment were 77.4% for all patients (567/733), 80.6% for patients who received tigecycline as monotherapy (329/408), 75.2% for patients with a nosocomial infection (354/471), 75.8% for patients with an APACHE II score .15 (250/330) and 54.2% (32/59) for patients with a SOFA score =7. Conclusions: In these real-life studies, tigecycline, alone and in combination, achieved favourable clinical response rates in patients with cIAI with a high severity of illness

Genetic Applications in Avian Conservation

A fundamental need in conserving species and their habitats is defining distinct entities that range from individuals to species to ecosystems and beyond (Table 1; Ryder 1986, Moritz 1994, Mayden and Wood 1995, Haig and Avise 1996, Hazevoet 1996, Palumbi and Cipriano 1998, Hebert et al. 2004, Mace 2004, Wheeler et al. 2004, Armstrong and Ball 2005, Baker 2008, Ellis et al. 2010, Winker and Haig 2010). Rapid progression in this interdisciplinary field continues at an exponential rate; thus, periodic updates on theory, techniques, and applications are important for informing practitioners and consumers of genetic information. Here, we outline conservation topics for which genetic information can be helpful, provide examples of where genetic techniques have been used best in avian conservation, and point to current technical bottlenecks that prevent better use of genomics to resolve conservation issues related to birds. We hope this review will provide geneticists and avian ecologists with a mutually beneficial dialogue on how this integrated field can solve current and future problems

Secure Faults Detection for Preventing Fire Risk in PV Systems.

Photovoltaic (PV) systems has been playing a key role during the last years in the evolution of electricity sector. Concerning the design issues for guaranteeing security and safety, it is particularly important to take into account that a PV plant is a "special" system of generation, in which the presence of a d.c. generator results in changings of the technical rules used for the design of electrical systems. Choices regarding the layout of the system, the grounding of the negative pole of the d.c. side and the means of protection are fundamental for the design of a PV system that takes into account the risk of fire. The subject of this article is the analysis of the relation between electrical phenomena that can occur inside of a PV system and the related means of protection (depending on the system’s architecture) that can guarantee the secure fault detection and so prevent the occurrence and development of a fire

@erasmus.it

@erasmus.it è un manuale di lingua italiana per studenti universitari di livello principiante, che propone situazioni di vita universitaria. L'approccio scelto, centrato sullo studente, intende favorire lo sciluppo delle abilità comunicative

Exploring the Role of Life Review Videos with Patients Diagnosed with Advanced Cancer

Background/Rationale Life Review Videos can provide patients with hope, help them finding meaning and value of life. Patients with cancer have limited opportunities to discuss their life before cancer. Insufficient research related to how patients would want their video to be used by family/friends and who they would chose to share their video with. Limited research regarding whether the relationship with the interviewer matters to participants of life review.https://jdc.jefferson.edu/medoncposters/1005/thumbnail.jp