Low Resistance Research Articles

Synthesis of nitrogen-doped carbon dot/tin disulfide nanosheet composite electro-catalysts for dye-sensitized solar cells.

Nitrogen-doped carbon dots (N-CDs) and vertically-grown tin disulfide (SnS2) nanosheets are synthesized via hydrothermal method and chemical vapor deposition technique, respectively. The SnS2nanosheets are directly fabricated on flexible carbon cloth (CC), and then their basal planes are decorated with N-CDs. The as-prepared composite electrodes are used as the counter electrode for the application in dye-sensitized solar cells (DSSCs). The characterizations of N-CDs and SnS2nanosheets are studied by high resolution transmission electron microscopy, scanning electron microscopic, energy dispersive x-ray spectrometer, Raman spectrometer and x-ray photoelectron spectroscopy etc. Moreover, the cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and photocurrent-density voltage are utilized to understand the electro-catalytic performance of N-CDs/SnS2/CC composite counter electrode. The N-CDs/SnS2/CC composite electrode shows higher cathodic reduction current density and lower charge transfer resistance in CV and EIS measurements, respectively, as compared to those of the electrodes with N-CDs or SnS2alone. Meanwhile, the DSSC using N-CDs/SnS2/CC exhibits cell efficiency (η) of 7.68%, which is higher than those of cells having SnS2/CC (η= 7.54%) and N-CDs/CC (η= 5.66%) counter electrodes, respectively; it also reaches 94% cell efficiency of the cell using Pt/CC counter electrode (η= 8.15%). The design concept of the modification of the basal planes by defect-rich carbon dots (i.e. N-CDs) and highly-exposed edge sites (i.e. vertically-grown SnS2nanosheets) makes promising route to enhance the performance of two-dimensional electro-catalysts.

Exploring the Lifeline: Unpacking the Complexities of Placental Vascular Function in Normal and Preeclamptic Pregnancies.

The proper development and function of the placenta are essential for the success of pregnancy and the well-being of both the fetus and the mother. Placental vascular function facilitates efficient fetal development during pregnancy by ensuring adequate gas exchange with low vascular resistance. This review focuses on how placental vascular function can be compromised in the pregnancy pathology preeclampsia, and conversely, how placental vascular dysfunction might contribute to this condition. While the maternal endothelium is widely recognized as a key focus in preeclampsia research, this review emphasizes the importance of understanding how this condition affects the development and function of the fetal placental vasculature. The placental vascular bed, consisting of microvasculature and macrovasculature, is discussed in detail, as well as structural and functional changes associated with preeclampsia. The complexity of placental vascular reactivity and function, its mediators, its impact on placental exchange and blood distribution, and how these factors are most affected in early-onset preeclampsia are further explored. These factors include foremost lipoproteins and their cargo, oxygen levels and oxidative stress, biomechanics, and shear stress. Challenges in studying placental pathophysiology are discussed, highlighting the necessity of innovative research methodologies, including ex vivo experiments, in vivo imaging tools, and computational modeling. Finally, an outlook on the potential of drug interventions targeting the placental endothelium to improve placental vascular function in preeclampsia is provided. Overall, this review highlights the need for further research and the development of models and tools to better understand and address the challenges posed by preeclampsia and its effects on placental vascular function to improve short- and long-term outcomes for the offspring of preeclamptic pregnancies. © 2024 American Physiological Society. Compr Physiol 14:5763-5787, 2024.

Cas12f1 gene drives propagate efficiently in herpesviruses and induce minimal resistance

BackgroundSynthetic CRISPR-Cas9 gene drive has been developed to control harmful species. However, resistance to Cas9 gene drive can be acquired easily when DNA repair mechanisms patch up the genetic insults introduced by Cas9 and incorporate mutations to the sgRNA target. Although many strategies to reduce the occurrence of resistance have been developed so far, they are difficult to implement and not always effective.ResultsHere, Cas12f1, a recently developed CRISPR-Cas system with minimal potential for causing mutations within target sequences, has been explored as a potential platform for yielding low-resistance in gene drives. We construct Cas9 and Cas12f1 gene drives in a fast-replicating DNA virus, HSV1. Cas9 and Cas12f1 gene drives are able to spread among the HSV1 population with specificity towards their target sites, and their transmission among HSV1 viruses is not significantly affected by the reduced fitness incurred by the viral carriers. Cas12f1 gene drives spread similarly as Cas9 gene drives at high introduction frequency but transmit more slowly than Cas9 gene drives at low introduction frequency. However, Cas12f1 gene drives outperform Cas9 gene drives because they reach higher penetration and induce lower resistance than Cas9 gene drives in all cases.ConclusionsDue to lower resistance and higher penetration, Cas12f1 gene drives could potentially supplant Cas9 gene drives for population control.

Designing and Optimizing Electrode Materials for Energy Harvesting in CAPMIX Cells

The growing demand for clean, decentralized energy has increased interest in blue energy, which generates power from water with different salt concentrations. Despite its potential as a renewable, low-cost energy source, optimizing electrode materials remains a challenge. This work presents a nanomaterial developed via microwave-assisted sol-gel methodology for blue energy applications, where ion diffusion and charge storage are critical. AX-7 carbon, designed for this study, features wide pores, enhancing ion diffusion. Compared to commercial NORIT carbon, AX-7 has a higher mesopore volume and external surface area, improving its overall performance. The synthesis process has been optimized and scaled up for evaluation in CAPMIX electrochemical cell stacks. Moreover, the lower series resistance (Rs) significantly boosts energy recovery, with AX-7 demonstrating superior performance. This advantage is especially evident during fresh-water cycles, where this material achieves significantly lower Rs compared to the commercial one.

Development of blue-light GaN based micro light-emitting diodes using ion implantation technology

This study fabricated 10 μm chip size μLEDs of blue-light GaN based epilayers structure with different mesa processes using dry etching and ion implantation technology. Two ion sources, As and Ar, were applied to implant into the LED structure to achieve material isolation and avoid defects on the mesa sidewall caused by the plasma process. Excellent turn-on behavior was obtained in both ion-implanted samples, which also exhibited lower leakage current compared to the sample fabricated by the dry etching process. Additionally, lower dynamic resistance (Rd) and series resistance (Rs) were obtained with Ar implantation, leading to a better wall-plug efficiency of 10.66% in this sample. Consequently, outstanding external quantum efficiency (EQE) values were also present in both implant samples, particularly in the sample implanted with Ar ions. This study proves that reducing defects on the mesa sidewall can further enhance device properties by suppressing non-radiative recombination behavior in small chip size devices. Overall, if implantation is used to replace the traditional dry etching process for mesa fabrication, the ideality factor can decrease from 11.89 to 2.2, and EQE can improve from 8.67 to 11.03%.

Novel Dynamic Organ Storage System Enhances Liver Graft Function in a Porcine Donation After Circulatory Death Model.

Donation after circulatory death (DCD) livers face increased risks of critical complications when preserved with static cold storage (SCS). Although machine perfusion (MP) may mitigate these risks, its cost and logistical complexity limit widespread application. We developed the Dynamic Organ Storage System (DOSS), which delivers oxygenated perfusate at 10°C with minimal electrical power requirement and allows real-time effluent sampling in a portable cooler. In a porcine DCD model, livers were preserved using DOSS or SCS for 10 hours and evaluated with 4 hours of normothermic MP, with n = 5 per group. After 4 hours of normothermic MP, the DOSS group demonstrated significantly lower perfusate lactate (p = 0.023), increased perfusate fibrinogen (p = 0.005), higher oxygen consumption (p = 0.018), greater bile production (p = 0.013), higher bile bicarbonate levels (p = 0.035) and bile/perfusate sodium ratio (p = 0.002), and lower hepatic arterial resistance after phenylephrine administration (p = 0.018). Histological analysis showed lower apoptotic markers in DOSS-preserved livers, with fewer cleaved caspase-3 (p = 0.039) and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL; p = 0.009) positive cells. These findings suggest that DOSS can enhance DCD allograft function during transport, offering potential clinical benefits and contributing to the expansion of the donor pool.

Tailoring Ga‐Doped ZnO Thin Film Properties for Enhanced Optoelectric Device Performance: Argon Flow Rate Modulation and Dynamic Sputtering Geometry Analysis

The impact of dynamic sputtering geometry on the properties of ZnO: Ga (GZO) thin film nanomaterials is investigated by systematically varying Ar flow rates and substrate positions during the film growth. The structural, optical, and electrical characteristics of GZO layers, deposited from a ZnO: Ga (5.7 wt%) ceramic‐type sputtering target, are comprehensively evaluated to reveal the relationship between the sputtering geometry and material properties. The obtained electrical properties, comparatively high carrier mobility 11.3 × 101 cm2 V−1 s−1 and the lowest resistivity 1.13 × 10−3 Ω‐cm, together with a moderately high optoelectric figure of merit with the films prepared using around 6 sccm Ar‐flow rate (corresponding to around 4.92 mTorr Ar partial pressure) reveal distinct correlations between the sputtering conditions and thin film properties, providing insights into the optimization of sputtering parameters for tailored material synthesis required for advanced and emerging applications. The GZO thin film (prepared with the optimal setting of 6 sccm Ar flow rate) exhibits remarkable optoelectronic capabilities as a transport layer in solar cells, reaching peak efficiencies of 26.34% for CIGS, 14.142% for CdTe, and 24.289% for Cs2AgBiBr6 perovskite in SCAPS‐1D simulated models. This study advances sputtering techniques for precise engineering of functional nanomaterials with enhanced performance and versatility, contributing to material synthesis optimization for emerging applications.

Ultra-thin p-AlGaN insert layer for enhancing the electrical performance of AlGaN-based deep-ultraviolet light-emitting diodes

A composite p-contact structure is proposed to enhance the electrical performance of AlGaN-based deep-ultraviolet light-emitting diodes (DUV-LEDs). With the insertion of a 1 nm-thick p-AlGaN layer prior to the contact layer, the operating voltage at 100 mA is significantly reduced by 0.2–0.3 V in 277 nm DUV-LEDs, leading to a maximum wall-plug efficiency of 10.7%. It is experimentally demonstrated that the reduction of operating voltage is mainly attributed to the lower specific contact resistivity of p-contact. The improvement mechanism of contact property is further explored by the theoretical calculations of energy band, where the hole accumulation in the contact layer, owing to the greater valence band offset induced by the p-AlGaN insert one, is speculated to promote the tunneling at the metal/semiconductor interface. The composite p-contact structure in this study is compatible with the present commercial DUV-LED epitaxial structure, enabling it to promote further development of this field.

Perspectives for improving deironing technologies groundwater for local drinking systems

In order to provide the population with high-quality drinking water, it is more expedient to focus on the use of underground sources of water supply, which are better protected from pollution in comparison with surface waters. However, a significant part of the underground sources of water supply is characterized by a high iron content, and the water from them needs to be deironed before being supplied to consumers. Removal of excessive iron content from underground water can be carried out by reagent or reagent-free methods, using water deiron installations of various design schemes and resorting to measures that increase the efficiency of their work. On the basis of the analysis of existing technologies for removing iron from groundwater and modern trends in the field of water purification, it is proposed for local water supply systems to use a filter with an automatic control valve and a technology that provides for reagent-free iron removal of groundwater due to the oxidation of dissolved iron with air cushion oxygen and further detention of the sediment formed in the layer of the multicomponent filter load. This technology is characterized by low cost and wear resistance of natural filter materials, ease of operation, environmental friendliness, which excludes secondary contamination of purified water with reagents, compactness and automation of control processes, which is especially relevant for small settlements.

Synthesis of porous carbon xerogel adsorbents with tailored hierarchical porosity and morphology for the selective removal of sulfamethoxazole from water.

In this work, pellet-type carbon xerogel adsorbents (CXCs) were synthesized through sol-gel polymerization of resorcinol (R) and formaldehyde (F) using Cs2CO3 (Cs) as a catalyst for the removal of sulfamethoxazole (SMX), a hazardous water pollutant. The R/Cs ratio was varied at 100, 500, 1000, and 2000 (denoted CXCs100, CXCs500, CXCs1000, and CXCs2000), resulting in CXCs with a well-defined hierarchical porous structure composed of interconnected spherical particles. Increasing the R/Cs ratio led to larger spherical particle sizes, with pore diameters ranging from 60.7 to 126.6nm, providing accessible and low flow resistance macroporosity. The maximum adsorption capacity was achieved in the CXCs100 sample (87.8mg/g), which decreased with increasing R/Cs ratios due to a reduction in total pore volume and meso and macropore areas, indicating that adsorption occurred in macropores and wide mesopores, driven by π-π dispersive interactions. CXCs500 emerged as the optimal adsorbent, with a favorable adsorption capacity (72.0mg/g) and adequate rigidity (315.9MPa) to prevent adsorbent breakdown. The adsorption capacity decreased with increasing pH due to electrostatic interactions, and increased with temperature, indicating an endothermic process.

Mechanical Performance and Tribological Behavior of WC-ZrO2 Composites with Different Content of Graphene Oxide Fabricated by Spark Plasma Sintering

This paper presents research on the effects of the addition of various contents of graphene oxide and sintering temperature on the mechanical, tribological, and electrical characteristics of WC-ZrO2 composites. Wet processing and spark plasma sintering provided dense samples with simultaneous reduction of graphene oxide (rGO) during sintering. The obtained results showed that the best mechanical properties were observed at a sintering temperature of 1700 °C in samples with 0.5 vol.% rGO content; namely, indentation fracture toughness (5.8 ± 0.4 MPa·m1/2) and flexural strength (872 ± 43 MPa) increased by 9% and 24.3% compared with the sample without rGO. In addition to improved mechanical performance, rGO-reinforced composites exhibited lower wear rates and friction coefficients than non-rGO composites, due to the formation of a graphitic lubricating tribolayer on worn surfaces and counterbodies in a friction pair, which provided sufficient lubrication to reduce the coefficient of friction and wear rate. The resulting composites also showed low electrical resistivity, suggesting the possibility of using electrical discharge machining to manufacture ceramic products of complex shapes from them.

Effects of Anisotropic Microstructure and Load Ratio on Fatigue Crack Propagation Rate in Additively Manufactured Ti-6Al-4V Alloy

Additive manufacturing (AM) refers to advanced technologies for building 3D objects by adding material layer upon layer using either electron beam melting (EBM) or selective laser melting. AM allows us to produce lighter and more complex parts. However, various defects are created during the AM process, which severely affect fatigue behavior. In the current research, the effects of the anisotropic microstructure in the in-plane and out-of-plane orientations and defects on the fatigue crack propagation rate (FCPR) and crack path were studied. A resonance machine was used to determine the fatigue crack propagation rate (da/dN vs. ΔK) from the near-threshold up to the final fracture, accompanied by in situ Acoustic Emission (AE) monitoring. Micro-Computerized Tomography (µCT) enabled us to characterize surface and microstructural defects. Metallography was used to determine the microstructure vs. orientations and fractography to classify the fatigue fracture propagation modes. Calculations of the local stress distribution were performed to determine the interactions of the cracks with the defects. In the out-of-plane direction, the material exhibited high fatigue fracture toughness accompanied by a slightly lower fatigue crack propagation rate as compared to in-plane orientations. The near-threshold stress intensity factor was slightly higher in the out-of-plane orientation as compared to that in the in-plane one, accompanied by a lower exponent of the Paris law regime. The threshold decreased with an increasing load ratio as expected for both orientations. The crack propagation direction that crosses the elongated grains plays an important role in increasing fatigue resistance in the out-of-plane direction. In the in-plane directions, the crack propagates parallel to the grain boundary, interacts with more defects and exhibits more brittle striations on the fracture surface, resulting in lower fatigue resistance.

Synergism of Arc Spraying, Laser Processing, and Hydrophobization for Long‐Lasting Corrosion Protection of MA8 Magnesium Alloy

Due to a number of unique properties, magnesium and its alloys are attractive for use in mechanical engineering, medicine, aviation, the automotive industry, etc. Unfortunately, the widespread use of these materials is limited by their low corrosion resistance. Traditional surface modification techniques have struggled to simultaneously enhance both the mechanical durability and corrosion resistance of magnesium‐based materials. Herein, a method synergistically combining the advantages of arc spraying, laser processing, and hydrophobization is developed. This finely tuned combination results in the production of an aluminum coating with superhydrophobic properties formed on top of magnesium alloy that has very high mechanical and chemical resistance. The results presented in this article demonstrate that such coatings preserve a constant contact angle exceeding 165° during a year of laboratory storage, withstand long‐lasting humid and salt fog atmosphere, demonstrate corrosion current lower than 3 × 10−8 A cm−2 during 120 days of its continuous contact with chloride‐containing corrosive environments, and preserve the superhydrophobic state after sand abrasion test. The corrosion inhibition mechanisms of the designed coating are discussed. The developed innovative approach addresses a critical challenge in enhancing the corrosion resistance of magnesium‐based materials, paving the way for their broader application across various industrial sectors.

Structural, Optical, Magnetic and Electrical Properties of Zinc Oxide Doped with Iron: A Review

This study reviewed the structural, optical, magnetic and electrical properties of zinc oxide (ZnO) nano-particles doped with iron relative to zinc oxide. ZnO is an excellent nanomaterial in semiconductor industries because of its properties such as low cost, high stability and high absorbance. However, its application has been limited because of some undesirable characteristics. Hence, doping with iron has proven essential in overcoming these limitations. The X-ray diffraction studies show that the structure is hexagonal with wurtzite structure, ZnO films prefer to grow in the (002) direction. This is because each apex is parallel to the c-axis in the wurtzite structure. This review reported that optical band gap ZnO nano-particles doped with iron was found to be in the range to (3.26 - 3.35) eV. The electrical properties of these films indicated low resistivity and consequently high electrical conductivity at high dopant iron concentration. Consequently, higher electrical resistivity was observed with lower conductivity at lower iron dopant concentration. Higher iron-doped ZnO (x=0.10 and 0.20) samples exhibited obvious ferromagnetic behaviors suggesting that saturation magnetization of Zn1-xFexO nano-particles increases with the increasing of Fe doping concentration compared with pure ZnO. Hence the SEM of iron-doped zinc oxide nano-particles consists of ellipsoidal shape particles, which are well dispersed with smooth surface and uniform size.

Development of High Strength, High Water Resistant, Low‐Formaldehyde Emission Urea‐Formaldehyde Adhesive and Its Effect on the Properties of Wood Composites

ABSTRACTUrea–formaldehyde (UF) resin adhesive is one of the most widely applied in wood composite materials. However, it suffers from issues related to low water resistance and elevated levels of formaldehyde emission. In this study, polyamide–epichlorohydrin resin (PAE) was used as a modifier and crosslinking agent to prepare modified UF resin adhesives with high strength and water resistance using low molar ratio UF resin. The interaction between PAE, UF, and wood surface and the effect of PAE on the chemical structure, thermal stability, bonding strength, water resistance, adhesive layer characteristics, and formaldehyde emission of UF adhesive were studied. Compared with the pure UF adhesive, after adding 5% PAE, the dry bonding strength reached 1.405 MPa, which was 20.70% higher than that of the pure UF adhesive. At the same time, the wet bonding strength reached 1.188 MPa, which was increased by 33.33%. In addition, the formaldehyde emission of the prepared plywood was less than 1.5 mg/L, which met the E1 standard. This work presents a novel approach to address the challenge of balancing water resistance and formaldehyde emissions in UF resin adhesives, expanding the industrial utilization of UF resin wood adhesives.

Pivmecillinam for Uncomplicated Acute Cystitis: A Contemporary Review.

To review the evidence and discuss use of pivmecillinam in uncomplicated acute cystitis. A literature search was conducted utilizing PubMed (from 2000 through August 2024) and ClinicalTrials.gov. Medical Subject Headings (MeSH) terms, such as mecillinam or pivmecillinam and urinary tract infections, were utilized. Additional references were identified by reviewing literature citations. Articles were limited to English language publications evaluating the efficacy or safety of pivmecillinam for urinary tract infections (UTIs) in adult populations. Data from 6 randomized controlled trials support pivmecillinam for acute uncomplicated cystitis at doses of 200 to 400 mg 3 times daily for 3 to 7 days, with more consistent clinical and bacteriologic cure observed with 400 mg doses and longer therapy durations. Clinical evaluation of 400 mg 2 to 3 times daily is available with use more common in non-US Food and Drug Administration (FDA)-approved populations, such as men, pregnancy, and multidrug resistant infections. There are limited data supporting pivmecillinam for pyelonephritis; routine use is cautioned until further clinical data are available. As resistance to first-line antimicrobials rises, the need for safe and effective treatment options remains high. Pivmecillinam represents a new therapeutic option available in the United States for outpatient management of uncomplicated acute cystitis. Pivmecillinam could be a key agent for uncomplicated acute cystitis. Utilization will likely be cost driven, but the promise of low resistance encourages the place in therapy when other agents are not susceptible to infecting uropathogens.

SEX DIFFERENCES IN SYSTEMIC INFLAMMATORY RESPONSE IN LOW HYPOXIA-RESISTANT RATS

OBSERVATION. Individual differences in hypoxia tolerance and expression of the hypoxia-inducible factor, HIF-1α, were found in humans and laboratory animals. This allowed us to distinguish groups of animals with low and high resistance to oxygen deficiency. It was shown that low hypoxia-resistant animals are characterized by a more severe course of the systemic inflammatory response (SIR). Sex differences in the severity of SIRS in animals with low hypoxia tolerance have not been studied. OBJECTIVE To characterize morphological and molecular-biological features of lipopolysaccharide (LPS)-induced SIR in low hypoxia-resistant male and female Wistar rats. MATERIALS AND METHODS. Low hypoxia-resistant animals were distinguished by the time of “life” in a hypobaric barocamera at an altitude of 11500 m (less than 60 s). SWO was modeled by intraperitoneal injection of LPS at a dose of 1.5 mg/kg. One day later, morphologic changes in the lungs, liver, and thymus, as well as endotoxin levels, corticosterone, HIF1-α, and TGFβ concentrations in serum from low hypoxia-resistant female and male Wistar rats were evaluated. RESULTS. Differences were found in control groups in females and males of low hypoxia-resistant rats, characterized by higher HIF1-α, corticosterone and endotoxin levels in serum in females. Thus, in females 24 h after LPS injection the number of neutrophils in interalveolar septa of lungs was higher and acute accidental involution of thymus with narrowing of subcapsular zone without changes in volumetric fraction of cortical substance developed. Whereas in males widespread pathological changes in the liver and more pronounced manifestations of accidental involution accompanied by narrowing of the volume fraction of the thymus cortical substance were revealed. In the blood serum of females with SWO, the content of corticosterone increased, while in males the concentration of HIF1-α and the level of endotoxin increased, and the content of TGFβ decreased. CONCLUSIONS. Although female and male rats were characterized by low resistance to hypoxia, the course of LPS-induced SWO and the development of immune reactions in animals have sex differences.

A Gravity-Driven Membrane Bioreactor in Treating Real Fruit Juice Wastewater: Response Relationship Between Filtration Behavior and Microbial Community Evolution

The issue of environmental pollution caused by wastewater discharge from fruit juice production has attracted increasing attention. However, the cost-effectiveness of conventional treatment technology remains insufficient. In this study, a gravity-driven membrane bioreactor (GDMBR) was developed to treat real fruit juice wastewater from secondary sedimentation at pressures ranging from 0.01 to 0.04 MPa without requiring backwashing or chemical cleaning, with the aim of investigating flux development and contaminant removal under low-energy conditions. The results demonstrate an initial decrease in flux followed by stabilization during long-term filtration. Moreover, the stabilized flux level achieved with the GDMBR at pressures of 0.01 and 0.02 MPa was observed to surpass that obtained at 0.04 MPa, ranging from 4 to 4.5 L/m−2 h−1. The stability of flux was positively associated with the low membrane fouling resistance observed in the GDMBR system. Additionally, the GDMBR system provided remarkable efficiencies in removing the chemical oxygen demand (COD), biological oxygen demand (BOD), ammonia (NH4+-N), and total nitrogen (TN), with average removal rates of 82%, 80%, 83%, and 79%, respectively. The high biological activity and microbial community diversity within the sludge and biofilm are expected to enhance its biodegradation potential, thereby contributing to the efficient removal of contaminants. Notably, a portion of total phosphorus (TP) can be effectively retained in the reactor, which highlighted the promising application of the GDMBR process for actual fruit juice wastewater based on these findings.

Exploring Raw Red Clay as a Supplementary Cementitious Material: Composition, Thermo-Mechanical Performance, Cost, and Environmental Impact

This study explored the potential of natural red clay as a supplementary cementitious material (SCM) to reduce greenhouse gas emissions and costs associated with the cement industry. Given that cement production is one of the largest contributors to global greenhouse gas emissions, developing sustainable alternatives is of paramount importance. Recognizing the environmental impact of cement production, this research investigates the substitution of conventional cement with raw red clay, aiming to balance mechanical performance with enhanced thermal properties and a lower environmental footprint. Through chemical characterization using X-ray Fluorescence (XRF), along with comprehensive mechanical and thermal performance testing, this study identifies the dual role of raw clay in mortar. It was found that incorporating up to 5% by weight of raw clay slightly impacted compressive strength while significantly improving thermal conductivity and diffusivity, cost-efficiency, and environmental sustainability, making it an appealing option for structural applications requiring high mechanical resistance. Conversely, a higher proportion of clay (beyond 5%) compromises compressive strength, but further enhances thermal properties and environmental benefits, suggesting its suitability for applications where low mechanical resistance is acceptable. This investigation highlights the viability of raw clay as a promising SCM, offering a pathway to more sustainable construction materials without the need for energy-intensive processing, thereby contributing to the reduction in the construction sector’s carbon footprint and energy demand.

TOPCon Solar Cells With Al-Free Ag and Cu Metallization

This work presents an approach to lower the silver consumption of screen printed TOPCon (Tunnel Oxide Passivated Contact) solar cells by reducing and partially replacing the silver by low cost copper metallization paste. On the solar cells front side an adapted process sequence enables the use of a pure Ag paste, which compared to the industrially established AgAl paste offers a better conductivity and respectively requires less laydown to enable similarly low grid resistance. On the solar cells rear side the conductivity of the metal grid is accomplished by a copper paste which is realized within a print-on-print step on top of the Ag contact layer with minimized laydown. A reduction in Ag paste consumption by 40% to less than 9 mg/ Wp without sacrificing conversion efficiency seems achievable and can enable a significant cost reduction for TOPCon solar cells.