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Recently, perovskite solar cells (PSCs) emerged and promise to break the prevailing solar energy paradigm by combining both low-cost and high-efficiency. PSC technology actually shivered the solar photovoltaic (PV) community as a strong candidate to rival the efficiency of traditional PV devices; in less than 12 years its efficiency was improved from 3.8% to almost 26%. Despite the tremendous and successful effort for obtaining PSC devices with high power conversion efficiencies, little efforts have been devoted to study fundamental engineering aspects essential for future industrial production. In particular, this work makes an analysis of the energy consumed and the carbon footprint of producing a 3-mesoscopic PSC 8 × 8 cm2module with an 8.7% efficiency in a life cycle perspective. A “cradle-to-gate” study was performed, using as much as possible primary data. Considering the PSC module as the functional unit the results show that the mesoporous layer deposition is the dominant term concerning the energy consumption. Regarding the carbon footprint, the gold layer, in particular gold, is the main factor. Changing the electricity source to renewable photovoltaic energy reduces significantly the carbon footprint. The results stress the need to replace gold, and use less severe operational conditions in the module production.

Pancreatic ductal adenocarcinoma (PDAC) is a common and lethal cancer. From diagnosis to disease staging, response to neoadjuvant therapy assessment and patient surveillance after resection, imaging plays a central role, guiding the multidisciplinary team in decision-planning.

Hematite photoelectrode is a promising candidate for photoelectrochemical (PEC) water splitting. However, the high density of surface defects and slow kinetics for oxygen evolution have restricted the PEC performance of hematite photoelectrodes, mainly their low photovoltage. This study provides the hematite surface modification combining two strategies, annealing at high temperatures (800°C) and coating with RuO2and IrO2/RuO2co-catalysts. IrO2/RuO2-coated hematite thin film exhibited a low turn-on potential of 0.48 VRHEand a final photovoltage of 1.20V, which is the highest photovoltage reported for hematite-based photoelectrodes. A photocurrent density of ca.1.52mAcm−2was obtained at 1.23 VRHE, corresponding to ca.140% increase compared to bare hematite; the photocurrent obtained at 0.60 VRHEwas 0.34mAcm−2, the highest value ever reported. The IrO2/RuO2-coated hematite photoelectrode showed a quite stable performance at 0.80 VRHEfor over 72h. The water oxidation efficiency was therefore enhanced with values above 90% for potentials higher than 1.00 VRHEdue to faster charge transfer and reduced electron-hole recombination at its surface.

Photoelectrodes that are efficient, highly stable, made from low cost materials and easily prepared using inexpensive techniques are required for commercially viable solar photoelectrochemical (PEC) water-splitting technology. Hematite is one of few materials that is being considered for this application. In this work, bare hematite thin films prepared by spray pyrolysis were systematically optimized following a design of experiments approach. A response surface methodology was applied to factors: (i) sprayed volume of solution; (ii) temperature of the glass substrate during the deposition; and (iii) time gap between sprays and the optimized operating conditions obtained were v=42mL, T=425°C and t=35s. The optimized hematite photoelectrode showed a photocurrent density of ca. 0.94mAcm−2at 1.45VRHE, without dopants or co-catalysts, which is remarkable for a thin film of ca. 19nm. The stability of this photoelectrode was assessed over 1000h of PEC operation under 1-sun of simulated sunlight. A record-breaking result was obtained with no evidences of hematite film degradation neither of current density loss. These results open the door to turn PEC cells into a competitive technology in the solar fuel economy.

To review the most common disorders depicted with conventional videodefecography, and to compare the defecographic abnormalities between symptomatic patients according to their gender and age.

Abstract: Corrosion of steel rebars in reinforced concrete is one of the major problems in the construction industry. Carbonation reactions of concrete with carbon dioxide and, mainly, the chloride salts action are the main causes responsible for concrete degradation. Protective coatings help to improve the durability of concrete structures by acting as a physical barrier against the corrosion agents. Waterborne paints are usually used for concrete protection rather than solvent-based paints since they are less pollutant. The aim of this work is to investigate the influence of the pore size and porosity on the permeability of the paints films toward sodium chloride. Three characterization methods from membrane science were implemented to characterize paint coatings. The time-lag method was used to determine the permeability toward the sodium chloride and toward helium and argon, these for approximately 100% relative humidity. From the seven waterborne paints formulated, only one was found to be suitable for surface protection of reinforced concrete, since its permeability toward NaCl was smaller than 10−14 m2 s−1, the threshold value required by National Laboratory of Civil Engineering (LNEC) in Portugal. For the formulated paints, it was observed that the average pore size correlates well with the permeability toward sodium chloride. This is an important result since obtaining the permeability toward sodium chloride of corrosion protective paints is very time consuming, while the average pore size can be obtained in a much shorter time.

Perovskite solar cells (PSCs) have experienced a rapid development during the past decade. For regular PSCs, device efficiency has reached already a power conversion efficiency (PCE) of 25.5%. Inverted PSCs have been attracting increasing attention owing to their easy fabrication, cost‐effectiveness, and suppressed hysteresis characteristics. A maximum PCE of 23.72% for these types of devices is already achieved and some recent progresses in their performance suggest that inverted PSCs are still far from being fully optimized. Great opportunities for reaching simultaneously high stability and efficiency are forecast. Within this work, the most recent developments concerning solar device structure, fabrication of perovskite films, hole and electron transport materials, and electrode contacts in inverted PSCs are overviewed. This work also focuses on stability issues, fabrication methods for large‐area inverted PSCs, encapsulation techniques, economic assessment, and environmental opportunities for hastening inverted PSCs for commercialization. This state‐of‐the‐art brings together the recent developments concerning perovskite structures, deposition methods, charge transport materials, and electrode contacts in inverted perovskite solar cells. Strategies to reach simultaneously high stability and efficiency are also forecast. Additionally, environmental opportunities, stability issues, fabrication methods for large‐area inverted perovskite solar cells, encapsulation techniques, and economic evaluation are also discussed.