Advanced Characterization and Optimization of NiOx:Cu-SAM Hole-Transporting Bi-Layer for 23.4% Efficient Monolithic Cu(In,Ga)Se2-Perovskite Tandem Solar Cells

The performance of five hole-transporting layers (HTLs) is investigated in both single-junction perovskite and Cu(In, Ga)Se₂ (CIGSe)-perovskite tandem solar cells: nickel oxide (NiO_x,), copper-doped nickel oxide (NiO_x:Cu), NiO_x+SAM, NiO_x:Cu+SAM, and SAM, where SAM is the [2-(3,-6Dimethoxy-9H-carbazol-9yl)ethyl]phosphonic acid (MeO-2PACz) self-assembled monolayer. The performance of the devices is correlated to the charge-carrier dynamics at the HTL/perovskite interface and the limiting factors of these HTLs are analyzed by performing time-resolved and absolute photoluminescence ((Tr)PL), transient surface photovoltage (tr-SPV), and X-ray/UV photoemission spectroscopy (XPS/UPS) measurements on indium tin oxide (ITO)/HTL/perovskite and CIGSe/HTL/perovskite stacks. A high quasi-Fermi level splitting to open-circuit (QFLS-V_oc) deficit is detected for the NiO_x-based devices, attributed to electron trapping and poor hole extraction at the NiO_x-perovskite interface and a low carrier effective lifetime in the bulk of the perovskite. Simultaneously, doping the NiO_x with 2% Cu and passivating its surface with MeO-2PACz suppresses the electron trapping, enhances the holes extraction, reduces the non-radiative interfacial recombination, and improves the band alignment. Due to this superior interfacial charge-carrier dynamics, NiO_x:Cu+SAM is found to be the most suitable HTL for the monolithic CIGSe-perovskite tandem devices, enabling a power-conversion efficiency (PCE) of 23.4%, V_oc of 1.72V, and a fill factor (FF) of 71%, while the remaining four HTLs suffer from prominent V_oc and FF losses.     

Key Performance Indicators for Strategic Healthcare Facilities Maintenance

The salient phases in a facility’s service life that are most decisive for the effectiveness of its facilities management (FM) are the preliminary design, construction, and maintenance. The effectiveness of facilities is vastly affected by decisions pertaining to the strategy of the organization that owns or uses the facilities. The goal of this study was to develop key performance indicators (KPIs) for strategic FM that will provide a conclusive approach towards the facility’s service life conditions. Parameters were developed by means of field surveys and statistical analyses, and were validated by means of case studies. The research resulted in a series of 11 KPIs for strategic healthcare FM, which can be classified into four categories: development, organization and management, performance, and maintenance efficiency parameters. The study proposes age and occupancy coefficients as essential parameters for the assessment of large healthcare facilities needs, as an effective measure for long term facility maintenance planning, and for measuring FM effectiveness. The paper stresses that strategic healthcare facilities management must integrate quantitative performance, manpower, and maintenance indicators.     

Changes in chemical constituents during the maturation and ripening of two commercially important pomegranate accessions

Pomegranate juice is well known for its health beneficial compounds. This study was undertaken to investigate changes in the major chemical composition in arils and peels during fruit maturation in two Israeli commercial accessions, ‘Wonderful’ and ‘Rosh-Hapered.’ In both accessions, the levels of total phenolic, antioxidant activity and hydrolysable tannins were reduced in the peels during maturation, while the anthocyanin level increased. The results show that the sugar content in the aril juice increased in both accessions while the levels of acidity and of citric acid decreased. However, these two accessions differed in other parameters in the aril juice, i.e., while the antioxidant and total phenolic contents significantly decreased in ‘Rosh-Hapered’, these changes were not observed in ‘Wonderful’. The anthocyanin level, however, increased in ‘Wonderful’ but did not change in ‘Rosh-Hapered.’ This knowledge could help establish the optimum harvest date ensuring the maximum nutritional properties of pomegranates.     

Pure CuBi2O4 Photoelectrodes with Increased Stability by Rapid Thermal Processing of Bi2O3/CuO Grown by Pulsed Laser Deposition

A new method for enhancing the charge separation and photo‐electrochemical stability of CuBi₂O₄ photoelectrodes by sequentially depositing Bi₂O₃ and CuO layers on fluorine‐doped tin oxide substrates with pulsed laser deposition (PLD), followed by rapid thermal processing (RTP), resulting in phase‐pure, highly crystalline films after 10 min at 650 °C, is reported. Conventional furnace annealing of similar films for 72 h at 500 °C do not result in phase‐pure CuBi₂O₄. The combined PLD and RTP approach allow excellent control of the Bi:Cu stoichiometry and results in photoelectrodes with superior electronic properties compared to photoelectrodes fabricated through spray pyrolysis. The low photocurrents of the CuBi₂O₄ photocathodes fabricated through PLD/RTP in this study are primarily attributed to their low specific surface area, lack of CuO impurities, and limited, slow charge transport in the undoped films. Bare (without protection layers) CuBi₂O₄ photoelectrodes made with PLD/RTP shows a photocurrent decrease of only 26% after 5 h, which represents the highest stability reported to date for this material. The PLD/RTP fabrication approach offers new possibilities of fabricating complex metal oxides photoelectrodes with a high degree of crystallinity and good electronic properties at higher temperatures than the thermal stability of glass‐based transparent conductive substrates would allow.     

Design methodology of refractive index engineering by implantation of high-energy particles in electro-optic materials

Slab waveguides were constructed in K(1-x)Li(x)Ta(1-y)Nb(y)O(3) crystals by the implantation of (12)C(+4) ions at 30 MeV and (16)O(+5) ions at 30 and 40 MeV. The waveguides were characterized by a prism coupler setup. A refractive index drop of 10.9% was observed in a layer formed by the implantation of (16)O(+5) ions at 30 MeV. The carbon-implanted waveguides were found to be thermally stable after annealing at 450 degrees C. A semiempirical formula for predicting the change in the refractive index given the parameters of the implantation process was developed. It is argued that the combination of the basic implantation process with the semiempirical formula can be developed to become a generic method for constructing complex electro-optic circuits with a wave-guided architecture.     

Identification of Main Lipid Components of Mole Rat Harderian Gland

The Harderian gland of the mole rat has been demonstrated to have appeasement qualities on conspecifics. In this study total lipid content of the Harderian gland of the mole rat was evaluated and analyzed by means of thin-layer chromatography (TLC), densitometry, gas chromatography–mass spectrometry (GC-MS), FAB-MS, and NMR. More than 50% of the gland's fresh weight is composed of lipids, making it the highest Harderian gland lipid content ever found in rodents. Male and female lipid components differ considerably. Both have wax esters as the main lipid component, but in females the alcohol components were usually chains of 12 carbons, while in males they were mostly chains of 16 carbons. In addition, while in females the fatty acid residues were usually saturated, in males there was a double bond in the middle of the chain. As many as 25 different esters were found in females, and only seven in males. However, in the male an unusual volatile compound identified as 1-(3)-hexenyl-benzene was found. This sexual dimorphism may show that the gland function is sex-specific, and gives support to our earlier reports that the mole rat Harderian gland may be a source of pheromones.     

A dual functional staged hydrogen purifier for an integrated fuel processor–fuel cell power system

This paper describes the operation of a dual functional, membrane/catalytic CO_x methanator, hydrogen purifier that is well-suited for an integrated fuel processor/fuel cell power system. In combination with a pressure swing reformer (PSR) and a PEMFC, the system provides high overall efficiency and portability for distributed power or onboard vehicle use. Gas testing results illustrate the ability of the purifier to produce fuel cell purity hydrogen at peak power flux. The durability of this purifier is shown by its ability to meet target hydrogen purity even with a membrane that permeates >3000 ppm CO. Gas purge streams from both fuel cell electrodes are combined with the membrane retentate and combusted in the PSR combustion cycle to provide heat for the reforming reaction leading to high thermal efficiency. Most significantly, it is shown that staging of this purifier, enables recovery of some fraction of the purified hydrogen at pressures substantially approaching that of the feed hydrogen partial pressure. This creates an onboard source of high pressure hydrogen to be optionally fed to a storage device for use during vehicle startup, or to the fuel cell, either directly or via the storage device, under high power load conditions. The beneficial impact of this two-stage, dual functional purifier on membrane cost, dependability and fuel processor/fuel cell integration, will be discussed.     

Hepatic Δ9, Δ6, and Δ5 desaturations in non-insulin-dependent diabetes mellitus eSS rats

Both diabetes mellitus type 1 and diabetes mellitus type 2 are widespread diseases that alter carbohydrate and lipid metabolism. e Stilmann-Salgado (eSS) rats are experimental animals that spontaneously evolve to a state similar to that of young people affected by non-insulin-dependent diabetes mellitus (NIDDM; type 2). Using 6-mon-old eSS rats that, according to the literature [Martinez, S.M., Tarrés, M.C., Montenegro, S, Milo, R., Picena, J.C., Figueroa, N., and Rabasa, S.R. (1988) Spontaneous Diabetes in eSS Rats, Acta Diabetol. Lat. 25, 303–313], had already developed insulin resistance, we investigated the changes evoked on Δ9, Δ6, and Δ5 liver desaturases. The abundance of mRNA and enzymatic activities were measured, as well as the FA composition of liver microsomal lipids. Compared to control rats, the mRNA content and activity of SCD-1 (stearoyl CoA-desaturase, isoform of the Δ9 desaturase) were significantly higher, urase, isoform of the Δ9 desaturase) were significantly higher, whereas the mRNA and activities of Δ6 and Δ5 desaturases were not significantly modified. Correspondingly, the proportion of 18∶1n−9 and the ratios of 18∶1n−9/18∶0 and 16∶1/16∶0 in lipids were significantly increased, whereas the proportion of 20∶4n−6 was unaltered. These effects were found while glycemia was constant or increased. The results are completely opposite those described in insulin-dependent diabetes mellitus (type 1), in which a depression of all the desaturases is found. They suggest that in eSS rats, the activities of the desaturases were not modified by an insulin-resistance effect. Moreover, we suggest that the enhancement of SCD-1 activity might be considered as another typical sign of the NIDDM syndrome, because it has also been found in other animal models of NIDDM, for example, the ones evoked by the sucrose-rich diet and in the Zucker rat.