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Integrating photovoltaics into windows provides the possibility of including an additional function of energy production to a conventional building fenestration component. There is no doubt that electrical power can be generated on-site. However, the effect of PV windows on the indoor luminous environment of the space served by them has not been comprehensively researched. This paper investigated the daylight performance of integrating four types of photovoltaics (semi-transparent thin film Cadmium telluride (CdTe) solar cells with 10% and 50% transparency, crystalline silicon solar cells with and without crossed compound parabolic concentrators (CCPC)) to a window of a typical south-facing office under different Window-to-Wall Ratios (WWRs). Annual useful daylight illuminance (UDI), daylight uniformity ratio (UR) and daylight glare probability (DGP) have been analysed based on dynamic simulation using RADIANCE. The simulation results show that windows integrated with crystalline silicon cells and CCPC optics have the potential to provide best daylight availability when compared with standard double glazed windows and other tested PV window prototypes, if it is applied to rooms with large WWRs (e.g. 60% or 75% WWR) at high latitudes (e.g. city of Harbin). Its application also improves the uniformity of daylight spatial distribution and eliminates the risk of glare. Semi-transparent CdTe PV window with 10% transparency can also improve the percentage of working hours that fall into UDI 500–2000lux range, however, it will result in the most sharp illuminance contrasts within the room. Applying all of these tested PV windows can effectively reduce the possibility of glare. • Window integrated PV provides daylight control in addition to energy generation. • Comprehensive daylight analysis was undertaken for four different PV windows. • Dynamic daylight metrics UDI, UR and DGP have been investigated using RADIANCE. • The effect of different WWRs on PV windows' daylight performance was explored. • PV windows can reduce the possibility of glare and maximise use the daylight. [ABSTRACT FROM AUTHOR]

Building-integrated semi-transparent photovoltaic windows (PV windows) have been considered as a potential candidate to replace conventional windows to improve building energy efficiency and hence reduce carbon emissions. With the integration of PV windows, the indoor luminous environment may be significantly affected. The presence of solar cells may cause undesirable shading, low illuminance levels and affect colour quality of the transmitted daylight. Therefore, it is important to comprehensively assess daylight performance of PV windows to ensure a comfortable luminous environment. In this study, the daylight performance of Cadmium telluride (CdTe) PV window with four different transparencies (i.e. 20%, 30%, 40% and 50%) applied to a cellular office space has been assessed in terms of daylight quantity and daylight quality. RADIANCE was selected to predict the annual daylight performance through advanced dynamic metrics including Useful Daylight Illuminance (UDI), simplified Daylight Glare Probability (DGPs) and Illuminance Uniformity (Uo). Correlated Colour Temperature (CCT) and Colour Rendering Index (CRI), which are two attributes to characterise the colour quality of transmitted daylight were used to evaluate performance of the selected PV windows. CCT and CRI were calculated under three CIE standard daylight scenarios (CCT of 4000 K, 6500 K and 25000 K respectively). It is found that CdTe PV windows can significantly improve the homogeneity of daylight distribution on a task area located close to the window and reduce the risk of daylight glare when compared with the performance of a conventional double glazing. Moreover, the recommended CCT (i.e. 3000–7500 K) can be achieved with the employment of CdTe PV windows under 4000 K and 6500 K daylight scenarios. All of the CdTe PV windows examined were able to maintain CRI at a comfortable level i.e. above 90 under the three daylight scenarios. • To evaluate the indoor luminous environment with semi-transparent CdTe window installed. • To assess the UDI, DGPs and U O using RADIANCE with CdTe windows installed. • To evaluate CCT and CRI influenced by CdTe windows using CIE standard. • The semi-transparent CdTe window offers good daylight quality and quantity. [ABSTRACT FROM AUTHOR]

Abstract Building-Integrated Photovoltaic Window can potentially improve building energy efficiency. However, with the integration of solar cells, the colour properties of daylight passing through PV windows may be affected. It is important to explore the colour properties of the transmitted daylight to ensure a comfort luminous environment for its occupants. In this study, the spectral transmittances of four types CdTe PV window have been measured, subsequently the colour properties of the tested windows are examined and evaluated by Correlated Colour Temperature (CCT) and Colour Rendering Index (CRI). It was found that CdTe PV windows can achieve recommended CCT (i.e. 3300-5000K) when the daylight source is in the range of 4000K and 6500K. The general CRI of all the CdTe PV windows can be maintained in a comfort range, which is higher than 90, under different daylight scenarios. [ABSTRACT FROM AUTHOR]

Highlights • Switchable ETFE cushions has been employed in building envelope for daylight and solar heat control. • Ray-tracing techniques were used to investigate the effects of various design aspects of the ETFE. • A parametric study was carried out investigating the optical performance of switchable ETFE. • The impact of switchable ETFE cushions on building performance were studied. Abstract A pneumatic multilayer foil construction with a kinetic shading mechanism has the potential to be an effective response to dynamic climatic factors, such as solar radiation, and therefore moderate the energy consumption of buildings. A parametric study was carried out on a switchable ethylene-tetrafluoroethylene (ETFE) foil cushion with the purpose of investigating the optical performance of an adaptive building envelope and its impact on building energy performance regarding heating, cooling and lighting. Ray-tracing techniques were used to investigate the effects of surface curvature, frit layout and frit properties, on the optical performance of the cushion in open and closed mode. A range of incidence angles for solar radiation were simulated. The results of the simulation showed an angle dependent optical behaviour for both modes. The influence of the dynamic shading mechanism on building energy performance was further evaluated by integrating the optical data obtained for the ETFE foil cushions in a comprehensive energy simulation of a generic atrium building using EnergyPlus. Results suggested that switchable ETFE foil cushions have a higher potential to reduce cooling and heating loads in different climatic regions, compared to conventional glazing solutions (i.e. uncoated double-glazing and reflective double-glazing), while providing good conditions of natural daylighting. Annual energy savings of up to 44.9% were predicted for the switchable ETFE foil cushion in comparison to reflective double glazing. As such, this study provides additional insight into the optical behaviour of multilayer foil constructions and the factors of design and environment that potentially have a major impact on buildings energy performance. [ABSTRACT FROM AUTHOR]

A novel series of in - situ dendrite Ti-based bulk metallic glass composites (BMGCs) were obtained. The Mo content of the dendrites monotonically increases from nil to 10.5 at% while the dendrite volume fraction and the composition of the amorphous matrix remain nearly invariant. It was found that the mechanical behaviors varied tremendously simply by changing the Mo content. Thus, the correlation between the composition and the mechanical behaviors under tension has been determined for in - situ dendrite Ti-based BMGCs for the first time. [ABSTRACT FROM AUTHOR]

Daylighting has been associated with improved mood, enhanced morale, increased visual comfort and reduced fatigue. Glazing with varying transmittance, colour or configuration may have significant effects on the quality and quantity of daylight within a building, thus good glazing design has posed significant challenges for building designers. Coloured glazing is broadly applied in modern offices worldwide and many studies have explored the effect of this glazing on human performance. Commonly studied are chromatic glazing typologies which offer a unidirectional shift in the colour of light to either bronze or blue. This alters the spectral ability of the glazing and thus changes the indoor luminous environment. It is reported that although occupants prefer warm light, people perform better under cool light condition. This project aims to implement patterns in chromatic glazing to introduce a two-directional colour distortion to alter the colorimetric characteristics of the glazing, heavily affecting the user's perception and performance in the luminous environment. More specifically, seven different indoor luminous conditions were created using various patterned chromatic glazing (100% CAR Blue, 70% CAR Blue, 30% CAR Blue, neutral clear glazing, 30% CAR Bronze, 70% CAR Bronze, and 100% CAR Bronze) to investigate their effect on human perception using a scaled test room (1:3 scaling) to simulate office working conditions. Both subjective (questionnaire on pleasantness, comfort, alertness) and objective (an achromatic Landolt ring test and a chromatic Landolt ring test) evaluations were carried out for the proposed window conditions. The results suggest that the patterned chromatic glazing conditions create a more desirable luminous indoor environment, as well as a more efficient working environment. The 30% blue and 70% blue glazing improved feelings of visual comfort compared to the 100% blue, whilst retaining the efficiency of task completion. Meanwhile the 30% bronze glazing increased the efficiency of task completion compared to the 100% bronze, whilst retaining the ratings for comfort and pleasantness. This implies that the design of patterned chromatic glazing which introduces the combination of two chromatic glazing may be a feasible solution to improve the indoor luminous environment. • To introduce chromatic glazing with designed patterns for two-directional colour distortion. • To investigate the effects of patterned chromatic glazing on participants' perception. • 30% bronze, 30% blue and 70% blue were the most appealing choice by occupants. [ABSTRACT FROM AUTHOR]

The Trombe wall (T-wall) has gained significant attention as an advanced building envelope capable effectively harvest solar energy. Improving the functionality and performance of the T-wall is critical for achieving energy-saving and positive energy buildings. This study focuses on enhancing the functionality and performance of the T-wall by incorporating with photovoltaic (PV) panels and aluminum panels in the T-wall chamber. Additionally, the PV panels and aluminum panels are laminated with photocatalyst and thermal materials to optimize their energy harvesting capabilities. In this photo/thermal catalytic Trombe wall system, the air within the wall system moves upwards due to thermal pressure and sweeps over the surface of the catalytic material when exposed to solar irradiation. Through the combined effects of solar energy and catalytic oxidation, the cold and dirty air in the chamber undergoes heating and purification processes, resulting in the desired heating effect while significantly improving the overall air quality within the environment. The experimental results highlight that the novel T-wall system offers a multifunctional solution that addresses electricity generation, heating, and improvement of indoor air quality. The main findings of this study are as follows: (1) During the period from 9:00 to16:00, the T-wall system demonstrates the ability to provide a range of 6.25 kJ/mol to 17.74 kJ/mol of heat and 0.075 kWh to 0.372 kWh of electricity per day. (2) In terms of indoor air quality improvement, the T-wall system exhibits a one-way sterilization efficiency of bacterial aerosols ranging from 0.204 to 0.347. (3) The comprehensive performance of the system was found to be optimal when the system spacing is 25 cm. (4) In terms of the layout of UV light, it was observed that at the top and bottom of the system yielded better sterilization efficiency. [ABSTRACT FROM AUTHOR]

Lightweight materials with good combinations of properties, such as high strength, ductility and damage tolerance, are highly desirable in engineering applications; nevertheless, it remains a challenge to "defeat" the generally exclusive relationships between different properties for structural materials. One viable means is to construct complicated architectures in materials. Here, we employ a lightweight Ti-based metallic glass (MG) and pure Ti as constituents and assemble them into a hierarchically-structured multiphase composite with tailored heterogeneity. The Ti-rich multiphase composite exhibits a relatively low density of 4.95 g ∙ c m − 3 owing to its high Ti content and a high strength of ∼1408 MPa derived primarily from the MG phase. The hierarchical architecture with tailored heterogeneity promotes the formation of abundant shear bands and microcracks in MG, yet inhibits their extension to avoid catastrophic fracture, thereby endowing the Ti-rich multiphase composite with a remarkable tensile ductility of ∼7.1% which is nearly two times that of the MG composite having similar phase constitution but a uniform structure. Moreover, this architecture causes crack-tip blunting by promoting plastic deformation, together with crack bifurcation and microcracking ahead of the crack tip, which bestows a high (notched) fracture toughness of ∼109 M P a ∙ m 1 / 2 which is around three times that of its counterpart. This study is intended to give insight for the architectural design of new materials by offering a viable means for their architectural construction to achieve good combinations of properties. [ABSTRACT FROM AUTHOR]

Impact deformed TiAl polysynthetic twinned crystal was investigated by scanning and transmission electron microscopy including aberration-corrected scanning transmission electron microscopy. Shear bands, deformation twins and dislocations were observed in γ-TiAl phase. Deformation twins were identified on both primary (11 1 ¯ ) and secondary (1 1 ¯ 1 ¯ ) twin planes, and dislocation structures were resolved on the coherent {111} twin boundaries. Among them, 1/6 < 211] pseudo-twin dislocations were observed on the coherent twin boundaries co-existing with 1/2 < 101] super-partial dislocations. Two types of shear bands were identified, one was composed of (11 1 ¯ ) twin lamellae inclined to the propagation direction of shear bands, while the other was composed of curved (1 1 ¯ 1 ¯ ) twin lamellae and its propagation is nearly parallel to the (1 1 ¯ 1 ¯ ) twin plane. [ABSTRACT FROM AUTHOR]