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Abstract: The effect of catalyst loading, operation temperature and co-infiltration of the palladium-based catalysts on the performance and stability of La0.8Sr0.2MnO3 (LSM) cathode of solid oxide fuel cells (SOFCs) is investigated. The result shows that adding a small amount of Pd catalyst (0.08mgcm−2) has a remarkable effect on the reduction of overpotential of LSM cathodes and high palladium loading is detrimental to the electrochemical activity of LSM cathodes. The performance and stability of the Pd-impregnated LSM cathodes can be enhanced significantly by co-infiltration of palladium with either 20 mol% of silver or 5 mol% of cobalt. Increased stability of the co-infiltrated catalyst materials is probably related to the enhanced resistance of the co-impregnated Pd0.95Co0.05 and Pd0.8Ag0.2 nanoparticles against agglomeration and sintering at SOFC operation temperatures. The results indicate the co-impregnation is effective not only to enhance the electrochemical activity but also to improve the stability of LSM cathodes for the O2 reduction reaction of SOFCs. [Copyright &y& Elsevier]

Abstract: La0.7Ca0.3Cr0.5Mn0.5O2.6/Gd-doped ceria (LCCM)/GDC composite oxides are developed as anodes for the hydrogen and methane oxidation reactions of solid oxide fuel cells (SOFCs). The composite anodes are sintered in temperatures range from 1150 to 1350°C and the lowest ohmic and polarization resistances of the cells are obtained on the anodes sintered at 1300°C. Electrode polarization resistance or area specific resistance (ASR) of the LCCM/GDC anode is 0.47Ωcm2 for the hydrogen oxidation reaction and ~2.2Ωcm2 for the methane oxidation reaction at 850°C. Addition of the Pd nanoparticles via a wet impregnation to the LCCM/GDC anodes decreases the ASR substantially to 0.15 and 0.23Ω cm2 for the hydrogen and methane oxidation reaction at 850°C, respectively. The reduction of the ASR is more pronounced for the methane oxidation reaction. The results indicate that the addition of Pd nanoparticles mainly affects the electrode process associated with the low frequencies, revealing the significant promotion effect of the impregnated Pd catalyst for the dissociation and diffusion processes of the hydrogen and methane oxidation reactions. The Pd-Impregnated LCCM/GDC composite anodes show a good stability in H2 and CH4 under conditions studied. [ABSTRACT FROM AUTHOR]

Introduction: Loss of the penis can have a devastating effect on the lives of sufferers with significant psychogenic implications. Penile reconstruction or phallus construction poses a difficult challenge and a demanding problem to the urologists and plastic surgeons. Different techniques have been used for construction of a total penis and reconstruction of severely injured penis. The objective of this review was to determine the efficacy, advantages and disadvantages of the most popular penile reconstruction (PR) and phallus construction techniques. Materials and Methods: We searched without language restriction MEDLINE, Pre-MEDLINE EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) from January 1960 to January 2009. In addition, we searched the citation lists of relevant articles and book chapters. Studies evaluating the functional and cosmetic results of different techniques of total phallus construction (TPC) and penile reconstruction (PR) were identified. Two authors independently evaluated studies for selection, study quality, and extracted data. The primary outcome was creation of a sensate and cosmetically acceptable phallus. The secondary outcomes were competent neourethra that allows voiding in comfortable position, sexual intercourse, and the rate of complications. Results: One hundred and forty-six studies with a total of 1 622 patients were included in this review. Conclusion: Data from the available studies are insufficient to recommend any technique for TPC or PR. In the absence of evidence to support any method, the review authors recommend the one-stage TPC or PR. Further studies are warranted, preferably multi-centered studies. [ABSTRACT FROM AUTHOR]

Solid Oxide Cells (SOC), as a key energy-conversion technology, require sintering at temperatures exceeding 1200 °C, which tend to coarsen the structure of the fuel electrode. Nanostructured electrodes with high surface areas can help to decrease the electrode resistance and facilitate the operation of the SOC stacks at low temperatures with current collectors made from cheaper steel types. In this paper, we demonstrate and carefully evaluate a novel low-temperature manufacturing method for nanostructured Strontium Iron Molybdenum Oxide (SFM)/Gadolinium Doped Ceria (CGO) composite electrodes. The composite electrodes are applied on both sides of a Zr-based electrolyte with CGO barrier layers and sintered at 800 °C for 3 h in a 5% H 2 /N 2 atmosphere. The preparation parameters, thermal behavior, and electrode microstructure are studied to improve electrochemical performance. Based on the fitting of Nyquist plots, the electrochemical performance is mainly limited by two reactions in series at low frequency, in the 0.08–1 Hz and 1–50 Hz ranges. The electrode polarization resistance is almost constant at 1.24 Ω cm2 for 110 h at 750 °C in 60 vol% CO/CO 2. Unlabelled Image • A crack-free SFM/CGO composite fuel electrode prepared at 800 °C without formation of the SrZrO 3 insulator phase. • The electrochemical behavior obtained in CO/CO 2 and H 2 with 3 to 50 vol% H 2 O. • The relatively small polarization resistance makes it a candidate for substitution of the state-of-art Ni/YSZ electrode. • The quite dense and thin CGO barrier layer is applied via Radio-frequency magnetron sputtering. [ABSTRACT FROM AUTHOR]

Mixed ionic-electronic conductor LSCF is a popular cathode material for intermediate to low temperature solid oxide fuel cells; nevertheless, there are concerns about its surface-limited oxygen reduction reaction. In this work, Ruddlesden-Popper-structured La 2 NiO 4+δ (LNO) nanoparticles are introduced onto the surface of (La 0.6 Sr 0.4) 0.995 Co 0.2 Fe 0.8 O 3-δ (LSCF) cathode and the electrode performance is examined by means of electrochemical impedance spectroscopy (EIS) in the temperature range of 550–750 °C. Impedance spectra analysis shows that an 81% reduction in polarization resistance can be achieved by infiltration of LNO nanoparticles. The distribution of relaxation times (DRT) technique is used to gain insights on the physicochemical properties of the system under study. Obtained results reveal that by correlating oxygen surface exchange, bulk diffusivity, ionic conduction, and particle size of nano-structured LNO with the electronic and ionic conductivity of LSCF, the electrochemical behavior of the cathodes is improved. [ABSTRACT FROM AUTHOR]

• Facile route was developed to produce nanostructured LiFePO 4 olivine phase. • Medium milling energy decreased the formation temperature of LiFePO 4 well below 500 °C. • Activated carbon coating improved the capacity, rate capability and stability of battery. Nanostructured olivine LiFePO 4 was successfully synthesized by mechanical activation of powder obtained by co-precipitation. The effects of mechanical activation energy, calcination temperature and carbon coating on the LiFePO 4 characteristics were investigated. X-ray diffraction results revealed that mechanical activation has facilitated the formation of pure, fully crystallized and nano-structured LiFePO 4. Scanning electron microscope observations showed that the average particle size of LiFePO 4 powder is approximately 70 nm. Fourier transform infrared spectra analysis revealed the existence of no extra peak in the carbon coated LiFePO 4 samples compared to the pure one. Raman spectra demonstrated high quality of the obtained carbon layer with sp2/sp3 ratio of about 0.9 which proves the existence of highly conductive graphite like carbon in the cathode materials. Electrochemical analyses showed superior properties in the fields of capacity (163 mA h g−1 at 0.1C), rate capability, and battery stability over 50 cycles for mechanically activated LiFePO 4 /C cathode materials. [ABSTRACT FROM AUTHOR]

In this article, we report the effects of slurry formulation and sintering conditions on the microstructure and permeability of porous titania sheets prepared by tape casting. It was found that solid concentration and binder content in the titania slurry play a vital role in the porosity and microstructure of the sintered titania sheets. Solid concentration and binder content were optimized based on the green tape quality and open porosity of the sintered titania sheets. The optimum solid concentration with the lowest surface roughness was obtained at 0.61 g/cm3. The effects of temperature and sintering time on the open porosity and crystal structure of the final product were also investigated. Increasing the sintering temperature from 1000 to 1100 °C resulted in increasing the pore size from 170 to 264 nm and decreasing the open porosity. Finally, water permeability of the porous titania sheets was studied to evaluate the permeation flux and maximum operating pressure. The results revealed that the permeability of the porous titania sheet is increased not only by increasing the open porosity but also by increasing the pore size. [ABSTRACT FROM AUTHOR]

As the solid oxide cells (SOCs) are becoming durable, their air electrode materials require investigation for their tolerance against chromium (Cr) poisoning. Herein, La 2 NiO 4±δ (LNO), a highly electroactive and nucleation agent-free material, is infiltrated into the (La,Sr)MnO 3-δ (LSM) backbone to diagnose its' influence on the Cr-poisoning of LSM. While the non-impregnated LSM's degrades by Cr contaminant, LNO-infiltrated LSM (LSM.LNO) shows less sensitivity to Cr presence specifically during the electrolysis mode. LNO's presence inhibits the formation of detrimental phases at the electrode/electrolyte interface during the anodic polarization in Cr-containing ambient. Moreover, surface promotion by LNO nanoparticles reduces, but not inhibits, the formation of undesirable phases during the cathodic polarization in the Cr presence. According to the electrodes' overpotential trends, the electrochemical impedance spectroscopy (EIS) responses in addition to the distribution of the relaxation times (DRT) analysis, the presence of Cr alters the LSM.LNO's electrochemical characteristics via reacting with the nanoparticles. As the XRD analysis proves, LaCrO 3 formation on the LNO nanoparticles' surface gradually decays the LSM.LNO's cathodic performance. However, LNO's higher activity for oxygen evolution than oxygen reduction reaction accompanied by slower LNO/Cr reaction kinetics during anodic polarization improve and stabilize the LSM.LNO's anodic performance in Cr-containing environment. [Display omitted] • LNO impregnation improved LSM's ORR and OER performance. • LaCrO 3 formation was detected after LNO/Cr reaction. • LSM.LNO anode showed a stable behavior against Cr-poisoning. • Gradual formation of LaCrO 3 continuously impeded the ORR activity of the LSM.LNO cathode. • Detrimental phase formation was totally inhibited in the LSM.LNO anode. [ABSTRACT FROM AUTHOR]

Metal-air rechargeable batteries are being studied as an alternative to lithium-ion batteries. MnCo 2 O 4 as a ternary mixed metal oxide appeared as a promising oxygen electrocatalyst in metal-air batteries due to relatively high electrocatalytic activity and electronic conductivity. The effects of surface facets and calcination temperature on the electrochemical properties of MnCo 2 O 4 in zinc-air batteries are investigated experimentally and theoretically. The results show that by increasing calcination temperature, the surface facet is changing from the high index {112} to the low index {110}. Concurrently, the oxygen vacancy concentration rises with calcination temperature. Electrochemical results and first principle calculations indicate that the oxygen-deficient {110} facet has superior electrochemical activity over the {112} facet in terms of oxygen evolution reaction and oxygen reduction reaction. These results are essential for designing high performance spinel structured electrocatalyst materials. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • The equivalent circuit of LR Ω (QR H)G was proposed based on the EIS response and DRT analysis of SFM/GDC cathode. • The LF part of EIS were related to the Gerischer response of SFM/GDC composite electrode. • Pd infiltration reduced the R G by 48% and 10% at 650 °C and 800 °C, respectively. • Surface exchange kinetics of SFM/GDC air electrode needs enhancement at intermediate temperatures. Employing potent advanced materials to perform as the cathode of SOFC requires a profound investigation on the material's electrochemical response within the oxygen reduction reaction. Accordingly, in this research, electrochemical characteristics of Sr 2 Fe 1.5 Mo 0.5 O 6-δ /Gd 0.1 Ce 0.9 O 1.5 (SFM/GDC) air electrode was studied using electrochemical impedance spectroscopy (EIS) and distribution of relaxation time (DRT) technique. SFM/GDC composite electrode sintered at 1050 °C shows the lowest polarization resistance of 0.23 Ω.cm2 at 800 °C. Three DRT peaks determined, and an LR Ω (QR H)G equivalent circuit is proposed for the EIS response, in which the Gerischer element was related to the low-frequency part. Two of the peaks indicated by DRT were associated to the Gerischer response, which reveals simultaneous occurrence of oxygen surface reaction and diffusion sub-processes during ORR. By temperature rising from 650 °C to 800 °C, Gerischer resistance (R G) reduces by 91%. Introduction of Pd nanoparticles into the electrode reduces the R G by 48% and 10% at 650 °C and 800 °C, respectively. The results demonstrate that at the intermediate temperature range, the SFM/GDC composite electrode requires improvement by surface decoration due to its insufficient surface exchange kinetics; however, significantly improved surface exchange kinetics is observed at higher temperature range without any surface modification. [ABSTRACT FROM AUTHOR]

The mechanism of non-stoichiometric MnCo 2 O 4+δ to stoichiometric MnCo 2 O 4 structural transformation in the calcination temperature range of 350–650 °C and its morphology evolution from nanoplates with {112} facets to quasi nanoplates with {110} facets in the preferential orientation of [220] direction is investigated in detail and confirmed using XPS, HRTEM, TGA, and XRD analysis. By having a profound understanding of this mechanism, MnCo 2 O 4 with a well-controlled structure and morphology was synthesized via co-precipitation as the anode for Li-ion batteries to overcome the capacity fading issue. Moreover, the anode microstructure was optimized based on the correlation between Li+ storage, electrode durability, and interfacial resistance through the electrochemical response of electrode components, including MnCo 2 O 4 , carbon black, and binder. The optimum electrode exhibited a high initial discharge capacity of 2063 mAh g−1 at 400 mA g−1, excellent rate capability (807 mAh g−1 at 1000 mA g−1), and outstanding cycling performance (709 mAh g−1 at 400 mA g−1 after 150 cycles). These are attributed to the balance between the high surface area and robust architecture of MnCo 2 O 4 , and the stability, conductivity, and porosity of the electrode. [Display omitted] • Phase studies show that increasing the temperature to 650 °C resulted in the evacuation of excess oxygen in MnCo 2 O 4+δ. • By increasing the temperature, {112} facets alter to {110} facets in the preferential orientation of [220] direction. • The optimized electrode exhibited a stable reversible capacity of 709.5 mAh g−1 over 150 cycles at 400 mA g−1. [ABSTRACT FROM AUTHOR]

In the present study, the effect of different aluminum and vanadium precursors on the formation and physical properties of the V 2 AlC MAX phase were studied. The results showed that the synthesis of V 2 AlC is more favorable by elemental precursors than carbide precursors, and at least the presence of one metallic element is essential to accelerate the phase formation. The highest electrical conductivity (254 ± 12 Sm − 1) was for the sample with fine powders of VC and aluminum as precursors. The purest sample (76.2% wt. V 2 AlC) had metallic elemental precursors for both vanadium and aluminum sources and showed electrical conductivity of 188 ± 9 Sm − 1. The results showed that the specific surface area had no direct effect on the electrical conductivity because its increase can improve the electrical contacts between the powder particles and on the other side, it increases the surface resistivity. [Display omitted] • The V 2 AlC MAX phases were synthesized successfully using different precursors. • The presence of at least one metallic element is essential to form the V 2 AlC phase. • The surface area has a "double-edged sword" effect on electrical conductivity. [ABSTRACT FROM AUTHOR]

In this research, an experimental method for measuring the clamping force as a result of tightening torque in double lap simple bolted and hybrid (bolted-bonded) joints is proposed. Two types of joints, i.e. double lap simple and hybrid (bolted-bonded) joints were prepared for testing. In order to measure the clamping force or pretension resulting from the tightening torque at different applied torques, for both types of joints, a special experimental method was designed using a steel bush that was placed between the nut and the plate. Two strain gauges were stuck to the outer surface of the bush to measure the compressive axial strain and also the stress in the bush using Hooke's law. Finally, the axial force in the bush and subsequently the clamping force were determined. The test was repeated three times for each case to obtain the mean value of compressive strains and to determine the corresponding clamping forces. The relationship between the applied tightening torques and the mean value of compressive strains for both types of joints are shown in graphs. [ABSTRACT FROM AUTHOR]

Medical image segmentation is a critical task in computer vision because of facilitating precise identification of regions of interest in medical images. This task plays an important role in disease diagnosis and treatment planning. In recent years, deep learning algorithms have exhibited remarkable performance in this domain. However, it is important to note that there are still unresolved issues, including challenges related to class imbalance and achieving higher levels of accuracy. Considering the challenges, we propose a novel approach to the semantic segmentation of medical images. In this study, a new sampling method to handle class imbalance in the medical datasets is proposed that ensures a comprehensive understanding of both abnormal tissues and background characteristics. Additionally, we propose a novel loss function inspired by exponential loss, which operates at the pixel level. To enhance segmentation performance further, we present an ensemble model comprising two UNet models with ResNet backbone. The initial model is trained on the primary dataset, while the second model is trained on the dataset obtained through our sampling method. The predictions of both models are combined using an ensemble model. We have assessed the effectiveness of our approach using three publicly available datasets: Kvasir-SEG, FLAIR MRI Low-Grade Glioma (LGG), and ISIC 2018 datasets. In our evaluation, we have compared the performance of our loss function against four different loss functions. Furthermore, we have showcased the excellence of our approach by comparing it with various state-of-the-art methods., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest regarding the publication of this article. The research was conducted without any external funding support., (Copyright © 2024. Published by Elsevier Ltd.)

Iran supports a great share of exotic and/or endemic plant genera and species. The genus Fritillaria (Liliaceae) is a precious part of this botanical richness with 19 species, of which 10 are endemic to the country. However, signs are mounting that the country is truly at a crossroads when it comes to preservation of this national wealth. In this regard, an effective conservation strategy should thoroughly consider the classification of Fritillaria , as conservation practices are compromised by knowledge gaps in systematics and taxonomy. As published studies on Fritillaria in Iran have been sporadic and limited in scope, the aim of this review is to provide information necessary to help bridge these information gaps. Our objective is to facilitate increased understanding of the geographic, taxonomic, cytogenetic and phylogenetic status of Iranian Fritillaria , which is vital to meeting the goal of sustainable conservation of the genus in Iran and neighboring areas.