Solar heat and power with thermal energy storage in the UK

Solar energy has the potential to cover a high fraction of the demand for heat and electricity in residential buildings. Fig. 1 shows the variation in incident solar irradiation received across Europe. In London the annual solar irradiation is ~1100 kWh/m2 per year, while the typical domestic energy consumption per household is ~12000 kWh/year for heating and ~4000 kWh/year for electricity. Thus the solar energy received on a rooftop of ~15 m2 is enough potentially enough to provide the entire annual demand for domestic energy. Our research focuses on various aspects of two solar technologies for the combined provision of heating and power (CHP): solar organic Rankine cycle systems with low-to-medium temperature solar-thermal collectors (Figs. 2-3) and hybrid photovoltaic/thermal (PVT) systems. (Fig.4)

Dynamic testing and modelling of solar collectors

Solar-thermal collectors operating under real conditions rarely reach steady-state operation due to temporal fluctuations in the climate/environmental conditions and thermal loads. Figure 1 shows typical UK weather map. The incident irradiance, the ambient temperature and the wind speed can vary during the day as shown in Figures 2-4. These figures show the data collected in London at a temporal resolution of 1-minute. As a consequence of the time-varying inputs, collector models that describe dynamic behaviour are required for the accurate prediction of the thermal output and for optimising the control strategy of such systems. We develop detailed 3-D thermal sub-models that can be adapted to various geometries or collector configurations, including vacuum-tube thermal collectors, sheet-and-tube thermal and PV/T collectors

Some Considerations on the Behaviour of Bolted Stainless-Steel Beam-to-Column Connections: A Simplified Analytical Approach

Stainless-steel has proven to be a first-class material with unique mechanical properties for a variety of applications in the building and construction industry. High ductility, strain hardening, durability and aesthetic appeal are only a few of them. From a specific point of view, its nonlinear stress–strain behaviour appears capable of providing a significant increase in the rotational capacity of stainless-steel connections. This, in turn, may provide significant benefits for the overall response of a structure in terms of capacity and ductility. However, the bulk of the research on stainless-steel that has been published so far has mostly ignored the analysis of the deformation capabilities of the stainless-steel connections and has mostly focused on the structural response of individual members, such as beams or columns. For such a reason, the present study aims to contribute to the general understanding of the behaviour of stainless-steel connections from a conceptual, numerical and design standpoint. After a brief review of the available literature, the influence of the use of stainless-steel for column–beam connections is discussed from a theoretical standpoint. As a novel contribution, a different approach to compute the pseudo-plastic moment resistance that takes into account the post-elastic secant stiffness of the stainless-steel is proposed. Successively, a refined finite element model is employed to study the failure of stainless-steel column–beam connections. Finally, a critical assessment of the employment of carbon-steel-based design guidelines for stainless-steel connections provided by the Eurocode 3 design (EN 1993-1-8) is performed. The findings prove the need for the development of novel design approaches and more precise capacity models capable of capturing the actual stainless-steel joint response and their impact on the overall ductility and capacity of the whole structure

Multimodal assessment shows a mostly preserved cognitive status in incidentally discovered low grade gliomas: A single institution study

Incidentally discovered low-grade gliomas (iLGGs) are poorly reported in the literature. Still less is known about iLGG patients\u2019 neuropsychological profile: It is unclear whether iLGG patients are cognitively proficient, thus further confirming the concept of asymptomatic. From our monoinstitutional cohort of 332 patients operated for LGG from 2000 to 2017 we selected those who underwent a neuropsychological testing (n = 217, from 2008 to 2017), and identified 24 young (mean age 38.5 \ub1 1.06) patients with iLGGs (16 of 24, left hemisphere iLGGs, 8 of 24 right hemisphere iLGGs). The maximum lesions overlap occurred in the left inferior frontal gyrus and in the right anterior cingulate/superior medial frontal gyrus. Patients were cognitively preserved except mild to borderline difficulties in a few of them. The analysis of the equivalent scores (a score laying below or equal to the external nonparametric tolerance limit of adjusted scores corresponding to 0, 1, 2 and 3 are intermediate) highlighted the presence of additional borderline performances. Molecular class correlated with a normal function at visual\u2013spatial intelligence (p = 0.05) and at spatial short-term memory (p = 0.029). Results indicate that at this time of tumor growth, patients\u2019 cognitive abilities are still functional, but are slowly approaching the borderline level

A coupled thermal and electrical model of a sheet-and-tube hybrid photovoltaic/thermal (PV/T) collector

Papers presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 20-23 July 2015.The goal of this paper is to obtain the (pair of) efficiency curves of a hybrid PV/T collector with a sheet-and-tube design and to evaluate the effect of a non-uniform temperature distribution on the surface of the solar cell on its electrical power output. A 3-dimensional numerical model is developed to estimate the performance of such a collector. The model allows various design parameters of the PV/T to be varied so that the influence of each of these parameters can be studied on the overall system performance both at steady-state and at varying atmospheric conditions. The main parameters considered are the number of glass covers, ranging from an unglazed collector configuration to a double-glazed collector configuration, and the width-to-pipe diameter (W/D) ratio. The results show that, while the thermal efficiency increases with the additional glazing, the electrical efficiency deteriorates due to the higher temperature of the fluid and due to increased optical losses, as expected. The dynamic performance of the PV/T collector and system are also investigated. Results from the dynamic model and also from a simplified quasi-steady state model are reported. The results show that in the case of highly fluctuating incident radiation, e.g. from clouds, the quasi-steady solution can deviate by up to 20% from the dynamic solution in the evaluation of the thermal energy output in the case of low incident radiation with large fluctuations.am201

Risk Assessment by Pre-surgical Tractography in Left Hemisphere Low-Grade Gliomas

Background: Tracking the white matter principal tracts is routinely typically included during the pre-surgery planning examinations and has revealed to limit functional resection of low-grade gliomas (LGGs) in eloquent areas. Objective: We examined the integrity of the Superior Longitudinal Fasciculus (SLF) and Inferior Fronto-Occipital Fasciculus (IFOF), both known to be part of the language-related network in patients with LGGs involving the temporo-insular cortex. In a comparative approach, we contrasted the main quantitative fiber tracking values in the tumoral (T) and healthy (H) hemispheres to test whether or not this ratio could discriminate amongst patients with different post-operative outcomes. Methods: Twenty-six patients with LGGs were included. We obtained quantitative fiber tracking values in the tumoral and healthy hemispheres and calculated the ratio (HIFOF\u2013TIFOF)/HIFOF and the ratio (HSLF\u2013TSLF)/HSLF on the number of streamlines. We analyzed how these values varied between patients with and without post-operative neurological outcomes and between patients with different post-operative Engel classes. Results: The ratio for both IFOF and SLF significantly differed between patient with and without post-operative neurological language deficits. No associations were found between white matter structural changes and post-operative seizure outcomes. Conclusions: Calculating the ratio on the number of streamlines and fractional anisotropy between the tumoral and the healthy hemispheres resulted to be a useful approach, which can prove to be useful during the pre-operative planning examination, as it gives a glimpse on the potential clinical outcomes in patients with LGGs involving the left temporo-insular cortex

Some Considerations on the Behaviour of Bolted Stainless-Steel Beam-to-Column Connections: A Simplified Analytical Approach

Data Availability Statement: Data sharing not applicable. No new data were created or analyzed in this study.Stainless-steel has proven to be a first-class material with unique mechanical properties for a variety of applications in the building and construction industry. High ductility, strain hardening, durability and aesthetic appeal are only a few of them. From a specific point of view, its nonlinear stress–strain behaviour appears capable of providing a significant increase in the rotational capacity of stainless-steel connections. This, in turn, may provide significant benefits for the overall response of a structure in terms of capacity and ductility. However, the bulk of the research on stainless-steel that has been published so far has mostly ignored the analysis of the deformation capabilities of the stainless-steel connections and has mostly focused on the structural response of individual members, such as beams or columns. For such a reason, the present study aims to contribute to the general understanding of the behaviour of stainless-steel connections from a conceptual, numerical and design standpoint. After a brief review of the available literature, the influence of the use of stainless-steel for column–beam connections is discussed from a theoretical standpoint. As a novel contribution, a different approach to compute the pseudo-plastic moment resistance that takes into account the post-elastic secant stiffness of the stainless-steel is proposed. Successively, a refined finite element model is employed to study the failure of stainless-steel column–beam connections. Finally, a critical assessment of the employment of carbon-steel-based design guidelines for stainless-steel connections provided by the Eurocode 3 design (EN 1993-1-8) is performed. The findings prove the need for the development of novel design approaches and more precise capacity models capable of capturing the actual stainless-steel joint response and their impact on the overall ductility and capacity of the whole structure.This research received no external funding