water pvt collectors performance comparison

Abstract Flat plate PVT water based technology presents many advantages in terms of overall performance and space saving than the PV modules and the solar thermal collectors installed separately. However, the electrical and the thermal performances of the PVT technologies are more deeply related to different influences factors, among which: the presence or absence of the air gap formed by the transparent frontal cover, the absorber configuration and the adopted PV technology. For that reasons, the proposed research is aimed to assess, under the energy point of view, a comparison between a covered and an uncovered PVT water collectors, realized with different PV cells coupled to two aluminium roll-bond absorbers characterized also by different channel arrangements. The performance analysis is based on energy simulations carried out with two mathematical models validated on experimental data at the Test Facility of the Politecnico di Milano

Long-term reliability of photovoltaic c-Si modules - A detailed assessment based on the first Italian BIPV project

Assessing the long-term reliability of PV systems is important for understanding their energy and cost efficiency. Typically, estimates and predictions are based on indoor tests and accelerated ageing. However, fluctuating and differently interacting outdoor factors such as solar radiation, dust, and shadowing in real environment can impact the actual performance. This paper examines alterations related to ageing of c-Si PV modules, firstly by classifying the main factors that affect aged c-Si PV modules and then assessing the impact on their performance degradation by analysing a pilot BIPV system at Politecnico di Milano after 20 years of actual operation. Such system, which is highly representative since is the first public BIPV plant funded in Italy, was carefully and continuously monitored during its operating life. In particular, according to the visual/IR inspection carried out after the 20th year of operation, the main observed alteration in the modules were discoloration of the encapsulant, delamination, and chalking of the backsheet. The I-V characterization shown that all sampled modules had an overall degradation rate of less than 20 %, which is within the warranty limit, although in many cases the degradation rate over time shows a non-linear trend. Only one module experienced a severe fault that caused the complete loss of functionality. Obtained results confirm the reliability of c-Si technology, stressing the importance of a careful monitoring especially after the 15th year, when an increase of the degradation rate might occur

Overheating Risks and Adaptation Strategies of Energy Retrofitted Historic Buildings under the Impact of Climate Change: Case Studies in Alpine Region

Energy retrofits can enhance the liveability and efficiency of historic buildings while preserving their historic and aesthetic values. However, measures like improved insulation and airtightness may increase their vulnerability to overheating and climate change may further worsen their performance in the future. This paper investigates indoor overheating risks brought by climate change in retrofitted historic buildings and proposes effective adaptation strategies. Firstly, local weather conditions are analysed to identify homogenous climatic zones. For each climatic zone, "a business-as-usual" emissions scenario is adopted, and most representative regional climate models are selected to obtain hourly output of future climate projection. A comparative study is adopted where typical alpine residential buildings, "Portici house", are simulated with regard to future energy use and indoor thermal state using the dynamic model in EnergyPlus. Energy use and indoor thermal conditions are compared before and after energy retrofit, as well as under present and future climate conditions. The results demonstrate that retrofit interventions could significantly improve energy efficiency of historic buildings in both present and future scenarios. A change in climate together with retrofit interventions will, however, result in higher risk of indoor overheating in South Tyrol. Potential negative side effects of energy retrofit could be controlled by adopting adequate shading and ventilation approaches that minimise, or eliminate, the risk of overheating during high temperature periods while optimising historic buildings' energy performance

Towards Sustainability Assessment of the Built Environment: A Classification of the Existing Challenges

The application of sustainability assessment in a decision context is associated with various challenges that explain why the transition to action-oriented knowledge still needs to be fulfilled. Therefore, this paper aims to explore the associated challenges in sustainability assessment in the decision context of the built environment. Several publications are reviewed to provide a systemic understanding of the associated complexities. The challenges in sustainability assessment in the built environment are categorized at different levels, from understanding to measurement and implementation. The challenges are further categorized into definition, context, interpretation, data, measurement methods, uncertainties, indicators and indices, results, coordination, conflicts, and action-oriented knowledge. Moreover, according to the nature of each challenge, they are classified into epistemological, methodological, and procedural challenges. The novelty of this review is that it reviews and reports almost all fragmentedly reported challenges in sustainability assessment of the built environment in the literature within a holistic framework that provides a clear understanding of the state of the art and second discusses them within an integrated framework (the Sustainability Assessment Network) including the position of active-role players to resolve them, including strategists, scientist, and stakeholders

POZ-, AT-hook-, and Zinc Finger-containing Protein (PATZ) Interacts with Human Oncogene B Cell Lymphoma 6 (BCL6) and Is Required for Its Negative Autoregulation.

The PATZ1 gene encoding a POZ/AT-hook/Kruppel zinc finger (PATZ) transcription factor, is considered a cancer-related gene because of its loss or misexpression in human neoplasias. As for other POZ/domain and Kruppel zinc finger (POK) family members, the transcriptional activity of PATZ is due to the POZ-mediated oligomer formation, suggesting that it might be not a typical transactivator but an architectural transcription factor, thus functioning either as activator or as repressor depending on the presence of proteins able to interact with it. Therefore, to better elucidate PATZ function, we searched for its molecular partners. By yeast two-hybrid screenings, we found a specific interaction between PATZ and BCL6, a human oncogene that plays a key role in germinal center (GC) derived neoplasias. We demonstrate that PATZ and BCL6 interact in germinal center-derived B lymphoma cells, through the POZ domain of PATZ. Moreover, we show that PATZ is able to bind the BCL6 regulatory region, where BCL6 itself acts as a negative regulator, and to contribute to negatively modulate its activity. Consistently, disruption of one or both Patz1 alleles in mice causes focal expansion of thymus B cells, in which BCL6 is up-regulated. This phenotype was almost completely rescued by crossing Patz1(+/-) with Bcl6(+/-) mice, indicating a key role for Bcl6 expression in its development. Finally, a significant number of Patz1 knock-out mice (both heterozygous and homozygous) also develop BCL6-expressing lymphomas. Therefore, the disruption of one or both Patz1 alleles may favor lymphomagenesis by activating the BCL6 pathway

Behavior Discovery and Alignment of Articulated Object Classes from Unstructured Video

We propose an automatic system for organizing the content of a collection of unstructured videos of an articulated object class (e.g. tiger, horse). By exploiting the recurring motion patterns of the class across videos, our system: 1) identifies its characteristic behaviors; and 2) recovers pixel-to-pixel alignments across different instances. Our system can be useful for organizing video collections for indexing and retrieval. Moreover, it can be a platform for learning the appearance or behaviors of object classes from Internet video. Traditional supervised techniques cannot exploit this wealth of data directly, as they require a large amount of time-consuming manual annotations. The behavior discovery stage generates temporal video intervals, each automatically trimmed to one instance of the discovered behavior, clustered by type. It relies on our novel motion representation for articulated motion based on the displacement of ordered pairs of trajectories (PoTs). The alignment stage aligns hundreds of instances of the class to a great accuracy despite considerable appearance variations (e.g. an adult tiger and a cub). It uses a flexible Thin Plate Spline deformation model that can vary through time. We carefully evaluate each step of our system on a new, fully annotated dataset. On behavior discovery, we outperform the state-of-the-art Improved DTF descriptor. On spatial alignment, we outperform the popular SIFT Flow algorithm.Comment: 19 pages, 19 figure, 3 tables. arXiv admin note: substantial text overlap with arXiv:1411.788

Acute otitis externa: Consensus definition, diagnostic criteria and core outcome set development.

OBJECTIVE: Evidence for the management of acute otitis externa (AOE) is limited, with unclear diagnostic criteria and variably reported outcome measures that may not reflect key stakeholder priorities. We aimed to develop 1) a definition, 2) diagnostic criteria and 3) a core outcome set (COS) for AOE. STUDY DESIGN: COS development according to Core Outcome Measures in Effectiveness Trials (COMET) methodology and parallel consensus selection of diagnostic criteria/definition. SETTING: Stakeholders from the United Kingdom. SUBJECTS AND METHODS: Comprehensive literature review identified candidate items for the COS, definition and diagnostic criteria. Nine individuals with past AOE generated further patient-centred candidate items. Candidate items were rated for importance by patient and professional (ENT doctors, general practitioners, microbiologists, nurses, audiologists) stakeholders in a three-round online Delphi exercise. Consensus items were grouped to form the COS, diagnostic criteria, and definition. RESULTS: Candidate COS items from patients (n = 28) and literature (n = 25) were deduplicated and amalgamated to a final candidate list (n = 46). Patients emphasised quality-of-life and the impact on daily activities/work. Via the Delphi process, stakeholders agreed on 31 candidate items. The final COS covered six outcomes: pain; disease severity; impact on quality-of-life and daily activities; patient satisfaction; treatment-related outcome; and microbiology. 14 candidate diagnostic criteria were identified, 8 reaching inclusion consensus. The final definition for AOE was 'diffuse inflammation of the ear canal skin of less than 6 weeks duration'. CONCLUSION: The development and adoption of a consensus definition, diagnostic criteria and a COS will help to standardise future research in AOE, facilitating meta-analysis. Consulting former patients throughout development highlighted deficiencies in the outcomes adopted previously, in particular concerning the impact of AOE on daily life

ANCA-associated vasculitis.

The anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) are a group of disorders involving severe, systemic, small-vessel vasculitis and are characterized by the development of autoantibodies to the neutrophil proteins leukocyte proteinase 3 (PR3-ANCA) or myeloperoxidase (MPO-ANCA). The three AAV subgroups, namely granulomatosis with polyangiitis (GPA), microscopic polyangiitis and eosinophilic GPA (EGPA), are defined according to clinical features. However, genetic and other clinical findings suggest that these clinical syndromes may be better classified as PR3-positive AAV (PR3-AAV), MPO-positive AAV (MPO-AAV) and, for EGPA, by the presence or absence of ANCA (ANCA+ or ANCA-, respectively). Although any tissue can be involved in AAV, the upper and lower respiratory tract and kidneys are most commonly and severely affected. AAVs have a complex and unique pathogenesis, with evidence for a loss of tolerance to neutrophil proteins, which leads to ANCA-mediated neutrophil activation, recruitment and injury, with effector T cells also involved. Without therapy, prognosis is poor but treatments, typically immunosuppressants, have improved survival, albeit with considerable morbidity from glucocorticoids and other immunosuppressive medications. Current challenges include improving the measures of disease activity and risk of relapse, uncertainty about optimal therapy duration and a need for targeted therapies with fewer adverse effects. Meeting these challenges requires a more detailed knowledge of the fundamental biology of AAV as well as cooperative international research and clinical trials with meaningful input from patients