Standard Conditions Research Articles

Post-fire bond-slip performance of concrete-filled stainless steel tube columns

Concrete-filled stainless steel tube (CFSST) structures exhibit superior strength, durability, and fire resistance. These attributes, coupled with their aesthetic appeal and corrosion resistance, make them highly suitable for a broad range of civil engineering applications, ensuring long-term performance and safety across diverse environments. This study investigates the post-fire bond-slip performance of CFSST structures to facilitate the strengthening and retrofitting of fire-damaged CFSST structures. The paper reviews the bond-slip performance and fire resistance of CFSST. A series of fire tests and push-out tests were conducted on 99 circular CFSST stub columns, considering variables such as fire duration, wall thickness of the stainless steel tube, and concrete strength. The analysis covers the slip mechanism, load-slip relationship, sliding load, ultimate displacement, and ultimate bond strength of specimens post-fire. The bonding force between interfaces transitions from cementation to mechanical interlock and ultimately to friction, with some overlap among these mechanisms. A positive correlation exists between sliding load and wall thickness when fire duration is short. For shorter fire durations, fire exposure reduces the ultimate displacement while increasing bond-slip stiffness. Finally, a formula is proposed to predict the ultimate bond strength of CFSST stub columns following exposure to ISO 834 standard fire conditions.

Unexpected changes in source apportioned results derived from different ambient VOC metrics

Although most source apportionments of VOCs use mixing ratios, about 23 % of published studies use mass concentrations. Thus, systematically exploring the changes in VOC source apportioned results caused by metric differences is important to assess the differences in key precursor apportionment results given the observed increases in O3 pollution situation. Different monitoring instruments measured hourly VOC volumetric concentrations in three typical Chinese cities (i.e., Qingdao, Shijiazhuang, and Zhumadian). Converting volumetric to mass concentrations under standard and/or actual temperature–pressure conditions, VOC values with different metrics were obtained. The impacts of different metrics on the source apportionments were then investigated. Compared to the positive matrix factorization of the volumetric data (VC-PMF), the VOC species concentrations with low relative molecular mass (RMM) in the factor profiles substantially decreased in mass data analyses (MC-PMF). However, those species with high RMM substantially increased. There were no substantial differences in the apportioned source contributions based on standard and actual condition mass concentrations. However, the high-low rankings of percent contributions apportioned using the volumetric and mass data produced substantial differences. Compared with the VC-PMF results, the percent contributions of sources dominated by species with low RMM (e.g., natural gas usage and mixed sources containing natural gas usage) apportioned by MC-PMF decreased, while those of sources that emitted high RMM species (e.g., solvent usage and mixed sources containing solvent usage) increased. Source apportionments based on the volumetric concentration data had more practical significance compared to the mass concentration data results for control strategy development since the mass data analyses created issues.

Implementation of a fluid balance control strategy in critically ill patients: POINCARE-2 trial process evaluation

BackgroundPOINCARE-2 trial aimed to assess the effectiveness of a strategy designed to tackle fluid overload through daily weighing and subsequent administration of treatments in critically ill patients. Even in highly standardized care settings, such as intensive care units, effectiveness of such a complex intervention depends on its actual efficacy but also on the extent of its implementation. Using a process evaluation, we aimed to provide understanding of the implementation, context, and mechanisms of change of POINCARE-2 strategy during the trial, to gain insight on its effectiveness and inform the decision regarding the dissemination of the intervention.MethodsWe conducted a mixed-method process evaluation following the Medical Research Council guideline. Both quantitative data derived from the trial, and qualitative data from semi-structured interviews with professionals were used to explain implementation, mechanisms of change of the POINCARE-2 strategy, as well as contextual factors potentially influencing implementation of the strategy.ResultsScore of actual exposure to the strategy ranged from 29.1 to 68.2% during the control period, and from 61.9 to 92.3% during the intervention period, suggesting both potential contamination and suboptimal fidelity to the strategy. Lack of appropriate weighing devices, lack of human resources dedicated to research, pre-trial rooted prescription habits, and anticipated knowledge of the strategy have been identified as the main barriers to optimal implementation of the strategy in the trial context.ConclusionsBoth contamination and suboptimal fidelity to POINCARE-2 strategy raised concerns about a potential bias towards the null of intention-to-treat (ITT) analyses. However, optimal fidelity seemed reachable. Consequently, a clinical strategy should not be rejected solely on the basis of the negativity of ITT analyses’ results. Our findings showed that, even in highly standardized care conditions, the implementation of clinical strategies may be hindered by numerous contextual factors, which demonstrates the critical importance of assessing the viability of an intervention, prior to any evaluation of its effectiveness.Trial registrationNumber NCT02765009

Polyurethane-Type Poly[3]rotaxanes Synthesized from Cyclodextrin-Based [3]Rotaxane Diol and Diisocyanates.

Synthesis of polyurethane-type poly[3]rotaxanes is achieved by polyaddition between a cyclodextrin (CD)-based [3]rotaxane diol and various diisocyanate species, which provide a more defined structure compared to conventional polyrotaxane syntheses. In this study, hydroxyl groups on CDs of [3]rotaxane diol are initially acetylated, and deprotected after the polyaddition to introduce polyurethane backbone structure into polyrotaxane framework. Despite a relatively complicated chemical structure, [3]rotaxane diol monomer is successfully synthesized in a high yield (overall 67%) without any taxing purification process, which is beneficial for practical applications. The polymerization itself proceeds well under a standard polyaddition reaction condition to afford corresponding polyurethanes around 80% yield with Mn > 30kDa. The poly[3]rotaxanes show different aggregation behavior or optical properties, whether or not acetyl groups are present, and are analyzed by XRD, SEM, and fluorescence measurements.

Comparative content analysis and biological activity studies of fatty and essential oils from some garlic products sold in Turkish community pharmacies, natural, and fermented garlic

AbstractGarlic (Alliaceae), an annual herb, is renowned not only for its distinctive flavor but also for its extensive therapeutic applications in managing various ailments and health conditions. In this study, garlic products identified as the best‐selling items in Turkish pharmacies for various purposes were compared with garlic grown under standard conditions in terms of chemical composition and antidiabetic, anticholinesterase, antimicrobial, and antioxidant properties. Three of garlic samples were prepared by researchers. According to survey results, the most commonly sold garlic‐related products in pharmacies are black garlic extract tablets (4), capsules (5), garlic oil (6), garlic oil pearls (7), and fermented garlic (8). Diallyl disulfide (DADS) was identified as a predominant compound in sampled oils, ranging from 4.9% to 48.6%. Another noteworthy finding is the identification of allyl methyl disulfide and allyl methyl trisulfide as major components in sampled oils, with concentrations spanning from 2.9% to 9.8% and 0.4% to 17.5%, respectively. In both 2,2′‐azino‐bis‐(3‐ethylbenzothiazoline‐6‐sulfonic) acid (ABTS·+) and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH•) tests, Sample 1 (fermented) exhibited the highest antioxidant activity. Sample 3 (cultivated) was richer in total phenol–total tannin content. Sample 6 exhibited the highest α‐glucosidase inhibition among antidiabetic activities, reaching 28.93%. Sample 5 capsules demonstrated the highest α‐amylase inhibition at 51.50%. Sample 7 exhibited the most notable inhibition against both acetylcholinesterase (22.92%) and butyrylcholinesterase (13.37%). Samples 3, 6, and 8 were found to be more effective against Candida tropicalis with minimum inhibitory concentration (MIC) = 625 μg/mL. A comprehensive study on garlic products, including popular items from Turkish pharmacies and those grown under standard conditions, revealed diverse chemical compositions and multifaceted health properties.

A critical Kirchhoff equation with a logarithmic type perturbation in dimension 4

In this paper, a critical Kirchhoff type elliptic equation involving a logarithmic type perturbation is considered in a bounded domain in . Three main features of the problem bring essential difficulties when proving the existence of weak solutions. The first one is the nonlocal term which makes the structure of the corresponding energy functional more complicated, the second one is that the problem is critical in the sense that the energy functional lacks compactness, and the third one is the appearance of the logarithmic term which satisfies neither the standard monotonicity condition nor the Ambrosetti–Rabinowitz condition. Moreover, the boundedness of the sequence is hard to obtain for Kirchhoff problems in dimension 4. By combining a result by Jeanjean (Proc. Roy. Soc. Edinburgh Sect. A, 1999, 129: 787–809) and a recent estimate by Deng et al. (Adv. Nonlinear Stud., 2023, 23: No. 20220049) with the mountain pass lemma and Brézis‐Lieb's lemma, it is proved that either the norm of the sequence of approximation solution goes to infinity or the problem admits a nontrivial weak solution, under appropriate assumptions on the parameters.

Comparison between Liquid Immersion, Laser Diffraction, PDPA, and Shadowgraphy in Assessing Droplet Size from Agricultural Nozzles

Spray droplet diameters play a key role in the field of liquid plant protection product (PPP) application technology. However, the availability of various measurement techniques, each with its unique operating principles for evaluating droplet size spectra, can lead to different interpretations of spray characteristics. Therefore, in this study, four measurement techniques—Liquid Immersion (LI), Laser Diffraction (LD), Phase Doppler Particle Analysis (PDPA), and Shadowgraphy (SG)—were utilized to evaluate the droplet size distribution of agricultural spray nozzles. Additionally, PDPA and SG were used to assess the average velocity of spray droplets. Experiments were conducted in three different laboratories with the main aim of comparing results obtained with various types of equipment utilized under ordinary practical conditions. Spraying tests were carried out using three flat fan nozzles and an air-induction flat fan nozzle. As a general trend, the lowest values for droplet diameters were measured using the Laser Diffraction technique, followed by Shadowgraphy. The PDPA technique provided the highest values for mean diameters (D10, D20, and D30) and the numeric median diameter (Dn0.5), whereas the Liquid Immersion method yielded the highest values for the Sauter mean diameter (D32) and volumetric diameters (Dv0.1, Dv0.5, and Dv0.9). Importantly, all measurement techniques were able to discriminate the four nozzles based on their Dv0.5 diameter. Average droplet velocities showed a similar pattern across the four nozzles with the PDPA and the SG measurement techniques. The differences in diameter values observed with the four measurement techniques underline the necessity of always including reference nozzles in spray quality assessments to base classifications on relative rather than absolute values.

Chemical Diversity of Aspergillus alliaceus Phenotypes: Discovery of brominated bianthrones with activity against triple-negative breast cancer cell lines.

Marine-derived fungi have emerged as a source for novel metabolites with a broad range of bioactivities. However, accessing the full potential of fungi under standard laboratory conditions remains challenging. LC-MS-based metabolomics in combination with varied culture conditions is a fast and powerful tool to detect new metabolites. Here, three developmental forms of the marine-derived fungusAspergillus alliaceuswere analyzed and 14 fungal metabolites, including new brominated polyketides (11-14) were isolated.Structure elucidation relied mainly on 1D and 2D NMR techniques and was supported by low- and high-resolution mass spectrometry and DFT-based computations. We sequenced theA. alliaceusgenome, identified the bianthrone-producing biosynthetic gene cluster, and conducted expression analysis on genes involved in sexual development and biosynthesis. TheNCI-60 cell line panel revealed selectivein vitroactivity against triple-negative breast cancer (TNBC) for the halogenated allianthrones and their full anti-proliferative and cytotoxic effects were evaluated in fiveTNBCcell lines.

Effects of Resting Conditions on Tensile Properties of Acid Aggregate Hydraulic Asphalt Concrete.

This study addresses the issue of construction stagnation affecting the adhesion and tensile properties of hydraulic asphalt concrete with acid aggregate. It investigates the impact of rest periods on the tensile characteristics of such materials under standard construction conditions. The influence of varying rest durations and asphalt temperatures on the tensile behavior of the concrete is assessed through indoor experiments. The bonding between asphalt and aggregate is examined, along with the tensile property variations of the concrete. The study found that the standstill time significantly affects the adhesion of asphalt, with the adhesion decreasing progressively with increased temperature and rest time, irrespective of the addition of anti-stripping agents. However, the inclusion of these agents can mitigate the reduction in adhesion. Furthermore, the study identified that rest duration has a more substantial impact on adhesion than temperature. The splitting tests demonstrate that the tensile properties of asphalt concrete are considerably affected by the resting time. Over a period of 0, 10, 20, and 30 days of rest, an increase in splitting strength and a decrease in splitting displacement were observed. The findings offer valuable insights for predicting the tensile performance of asphalt concrete in practical engineering applications after a period of rest.

Dosed Failure Increases Older Adult's Motivation for an Exergame.

We investigated whether dosed failure motivates older adults to perform more repetitions in an exergame that involves hitting targets with stepping movements. The effect of dosed failure was studied in a within-participants design in which all participants performed this exergame in both a Standard condition, in which one never fails, and in a Dosed Failure condition, in which we introduced about 30% failures. The order of conditions (Standard First or Dosed Failure first) was chosen randomly for each participant. Results showed that participants performed more repetitions in the Dosed Failure condition compared with the Standard condition, while play duration and subjective motivation at the moment of quitting did not differ. This shows that dosed failure motivated older adults to put a greater amount of effort to perform the exercise without affecting play duration or subjective motivation.

Enhancing Internal and External Stability of Perovskite Solar Cells Through Polystyrene Modification of the Perovskite and Rapid Open‐Air Deposition of ZnO/AlOx Nanolaminate Encapsulation

In this study, the internal and external stabilities of a p–i–n methylammonium lead iodide perovskite solar cell (PSC) are improved. Polystyrene (PS) is introduced into the perovskite layer to form a cross‐linked polymer–perovskite network, which enhances the nucleation and growth of the perovskite grains. Moreover, for the first time, 60 nm thick ZnO/AlOx nanolaminate (NL) thin‐film encapsulation (TFE) is deposited directly on the PSC using an atmospheric‐pressure (AP) spatial atomic layer deposition system operated in AP spatial chemical vapor deposition (AP–SCVD) mode. The rapid nature of AP–SCVD enables encapsulation of the PSCs in open air at 130 °C without damaging the perovskite. The PS additive improves the performance and internal stability of the PSCs by reducing ion migration. Both the PS additive and the ZnO/AlOx NL TFEs improve the external stability under standard test conditions (dark, 65 °C, 85% relative humidity [RH]) by preventing water ingress. The number and thickness of the ZnO/AlOx NL layers are optimized, resulting in a water–vapor transmission rate as low as 5.1 × 10−5 g m−2 day−1 at 65 °C and 85% RH. A 14‐fold increase in PSC lifetime is demonstrated; notably, this is achieved using PS, a commodity‐scale polymer, and AP–SCVD, a scalable, open‐air encapsulation method.

Assessment of the impact of physical and chemical factors of the production environment on the morphological state of target organs in an animal experiment

The study of the morphological state of target organs of outbred (nonlinear) laboratory mice ICR (CD-1), which were under prolonged dynamic influence of physical and chemical factors of the production environment under model conditions, is of wide research interest, as it allows to assess the impact of these factors at the tissue and cellular level and to identify the presence of pathological changes in relation to the group control that was not exposed to the studied factors of the production environment during the 90-day experiment, which has clinical and practical significance. When assessing the 90-day dynamics (from 0 days – 6 months (background) to 30–60–90 days – 7–8–9 months) of the impact of environmental factors on the morphological state of tissues and organs of outbred (nonlinear) laboratory mice ICR (CD-1), generally accepted and unified methods were used. Animals (weighing 45–50 gr., sexually mature age – 6 months) were divided into 3 experimental groups (vibration exposure, noise exposure, chemical exposure) of 30 individuals each (15 females and 15 males) and 1 control group (15 females and 15 males), kept in standard comfortable conditions, and not exposed to the factors of the production environment. The experiment was conducted in accordance with the rules adopted by the European Convention for the Protection of Animals Used for Experimental Scientific Purposes (Strasbourg, 1986), after approval by the Ethical commission of the Novosibirsk Research Institute of Hygiene of Rospotrebnadzor. Statistical processing of the research materials was carried out using standard Statistica 10.0 application programs. The morphological analysis of the target organs of experimental animals revealed the presence of a complex of pathological changes in the 90-day dynamics of the impact of factors of the production environment, compared with the morphological state of the organs in the control group. The results obtained have clinical and practical significance, as they allow us to justify preventive measures aimed at preventing the negative impact of long-term production factors on the labor contingent. Further study of the morphological state of target organs of ICR laboratory mice exposed to prolonged dynamic exposure to physical and chemical factors of the production environment under model conditions will contribute to the establishment of mechanisms for the development of occupational diseases and the development of scientifically based medical and hygienic measures aimed at preserving the health of the labor contingent in the management of labor longevity.

Theoretical insights into gas-sensitive properties of B, Ga and In doped WS2 monolayer towards oxygen-containing toxic gases

Oxygen-containing toxic gases such as CO and NOx (x = 1, 2) have presented significant challenges to both the atmospheric environment and human well-being, thus prompting the development of efficient gas sensors for their detection at room temperature. In this work, we investigated the feasibility of B, Ga, In-doped WS2 (B-WS2, Ga-WS2 and In-WS2) monolayers as potential gas-sensitive materials for monitoring CO and NOx based on first-principles calculations, with a specific focus on analyzing the adsorption energy, electronic properties and recovery time. The results show that the doping of B, Ga, In atoms enhances the conductivity of WS2 monolayer and significantly improves the adsorption properties of WS2 towards CO and NOx. With the exception of the CO@In-WS2 system, all the systems exhibit chemisorption with adsorption energies ranging from −0.56 eV to −3.18 eV. Interestingly, the presence of H2O, CO and N2 in the atmosphere does not affect the capturing ability of B-WS2, Ga-WS2 and In-WS2 towards the target gases. Moreover, with the exception of the CO@In-WS2 system, the critical desorption temperatures of CO and NOx all exceed 300 K, highlighting the potential of the B/Ga/In-WS2 as effective adsorbents for NO and NO2 at room temperature and standard atmospheric pressure. Finally, the sensitivity and recovery time of CO and NOx on doped WS2 are evaluated. The findings confirm that Ga-WS2 exhibits a well-balanced combination of sensitivity and response speed, making it suitable as a reusable gas sensor for the detection of CO and NO, while In-WS2 is suitable for detecting NO and NO2. This study offers valuable theoretical insights into the design of innovative gas nanosensors for the detection of oxygen-containing toxic gases.

Structure-function analysis of nucleotide housekeeping protein HAM1 from human malaria parasite Plasmodium falciparum.

Non-canonical nucleotides, generated as oxidative metabolic by-products, significantly threaten the genome integrity of Plasmodium falciparum and thereby, their survival, owing to their mutagenic effects. PfHAM1, an evolutionarily conserved inosine/xanthosine triphosphate pyrophosphohydrolase, maintains nucleotide homeostasis in the malaria parasite by removing non-canonical nucleotides, although structure-function intricacies are hitherto poorly reported. Here, we report the X-ray crystal structure of PfHAM1, which revealed a homodimeric structure, additionally validated by size-exclusion chromatography-multi-angle light scattering analysis. The two monomeric units in the dimer were aligned in a parallel fashion, and critical residues associated with substrate and metal binding were identified, wherein a notable structural difference was observed in the β-sheet main frame compared to human inosine triphosphate pyrophosphatase. PfHAM1 exhibited Mg++-dependent pyrophosphohydrolase activity and the highest binding affinity to dITP compared to other non-canonical nucleotides as measured by isothermal titration calorimetry. Modifying the pfham1 genomic locus followed by live-cell imaging of expressed mNeonGreen-tagged PfHAM1 demonstrated its ubiquitous presence in the cytoplasm across erythrocytic stages with greater expression in trophozoites and schizonts. Interestingly, CRISPR-Cas9/DiCre recombinase-guided pfham1-null P. falciparum survived in culture under standard growth conditions, indicating its assistive role in non-canonical nucleotide clearance during intra-erythrocytic stages. This is the first comprehensive structural and functional report of PfHAM1, an atypical nucleotide-cleansing enzyme in P. falciparum.

Modelling ultrasonic cavitation onset in spiral-wound reverse osmosis modules

A model was developed to predict the onset of inertial cavitation within a spiral-wound reverse osmosis module sonicated along its axis from within its pressure vessel. The aim was to investigate the scalability of ultrasonic antifouling for reverse osmosis applications. The model employs a one-dimensional discretization to represent the module feed channel, calculating each element's pressure, flow rate, permeate flux, and sonication intensity. The Blake threshold assesses whether the pressure amplitude at each element is sufficient to produce inertial cavitation. When applied with parameters from a typical small-scale reverse osmosis module, the model identified a linear relationship between inlet pressure and inertial cavitation onset location, with a constant inlet flow rate and sonication power. With a sonication power of 120 W and a flow rate of 8.796 × 10−5 m3 s−1, the model predicted that inertial cavitation could be induced throughout the reverse osmosis module with inlet pressures ranging from 335 kPa to 355 kPa. While these pressures may be inefficient from a permeate production standpoint compared to standard operating pressure, they could be produced temporarily as part of a regular membrane cleaning operation. The model estimates the system's power consumption during cleaning to be 134.8 W, approximately equal to the estimated system energy requirements under recommended operating conditions of 134.3 W. This suggests that this technology could integrate effectively with existing reverse osmosis systems.

Association between self-reported and objectively assessed physical functioning in the general population

Knowledge about a patient’s physical fitness can aid in medical decision-making, but objective assessment can be challenging and time-consuming. We aimed to investigate the concordance of self-reported health status and physical functioning with the 6 minute walking distance (6MWD) as objective measure of physical performance. The prospective characteristics and course of heart failure stages A/B and determinants of progression (STAAB) cohort study iteratively follows a representative sample of residents of the city of Würzburg, Germany, aged 30–79 years, without a history of heart failure (HF). The 6MWD was measured in 2752 individuals (aged 58 ± 11 years, 51% women) from a population-based cohort under strictly standardized conditions. Self-reported health status and physical functioning were assessed from items of the short form 36 (SF-36). After the respective classification of self-reported health status and physical functioning into ‘good’, ‘moderate’, and ‘poor’, we determined the association of these categories with 6MWD by applying a generalized linear model adjusted for age and sex. Prevalence of self-reported good/moderate/poor general health and physical functioning was 41/52/7% and 45/48/7%, respectively. Mean 6MWD in the respective categories was 574 ± 70/534 ± 76/510 ± 87 m, and 574 ± 72/534 ± 73/490 ± 82 m, with significant sex-specific differences between all categories (all p < 0.001) as well as significant differences between the respective groups except for the categories ‘moderate’ and ‘poor’ health status in men. This cross-sectional analysis revealed a strong association between self-reported health status and physical functioning with the objective assessment of 6MWD, suggesting that physicians can rely on their patients’ respective answers. Nevertheless, sex-specific perception and attribution of general health and physical functioning deserve further in-depth investigation. Decision-making based on self-reported health requires prospective evaluation in population-based cohorts as well as adult inpatients.

The Vps21 signalling pathway regulates white-opaque switching and mating in Candida albicans

ABSTRACT Candida albicans is able to switch between two epigenetic cell types, namely white and opaque. Multiple conserved signalling pathways control the switch between white and opaque cell types in response to environmental changes. Here, we report the regulatory roles of the endosomal Rab family GTPase Vps21 and associated key components of the Vps21 signalling pathway in white-opaque switching and mating in C. albicans. Deletion of VPS21 promoted a switch from the white to the opaque phenotype in the presence of N-acetyl-glucosamine (GlcNAc). Consistently, inactivation of the guanine nucleotide exchange factor of Vps21 (Vps9) and downstream components in the Vps21 pathway (Vps3, Vac1, and Pep12) had similar promoting effects on phenotypic switching. The mating efficiency of opaque cells is much higher than that of white cells under standard laboratory culture conditions. However, compared to the wildtype strain, the vps21/vps21, vps9/vps9, vps3/vps3, vac1/vac1, and pep12/pep12 mutant strains exhibited dramatically reduced mating efficiencies. Quantitative RT-PCR assays demonstrated that inactivation of the Vps21 signalling pathway led to downregulation of pheromone expression and mating response pathway associated genes. Taken together, our findings indicate that the conserved Vps21 signalling pathway plays critical roles in the regulation of cell-type switching and mating in C. albicans.

A filling rig for liquid and gas working fluids for two-phase thermal management systems

Two-phase cooling devices are used to remove and dissipate heat from high power-density electronic systems to maintain them within their operating temperature limits. The manufacture of these devices, such as heat pipes, thermosyphons or vapour chambers, involves firstly removing any internal air or non-condensable gases before charging with the required volume of working fluid. This paper presents detailed designs and operating instructions for a single bench-top station for use in a laboratory environment for the vacuum evacuation, degassing and charging of these devices. Two configurations allow for the filling of fluids which are either liquids or gases at standard temperature and pressure conditions. For liquids, the dispensed volume can be measured directly on an integrated burette, while the method of vapour transfer is used for gases.The hardware was demonstrated by filling multiple thermosyphon devices with a number of common working fluids used in two-phase systems, including water, acetone and ammonia. It was shown to deliver precise and repeatable filling volumes with average differences compared to target volumes of 1.7% and 10.5% for liquids and gases respectively. The design is intended to be highly customisable where its size can be modified to accommodate filling volume requirements for different applications.

High-temperature erosion behavior of Al2O3 reinforced Inconel625 high velocity oxy-fuel sprayed and direct-aged composite coatings

In this study, Inconel625+30%Al2O3 (IN30AL) blended powders were sprayed on a commercially used boiler steel ASTM SA210 GrA1 using high-velocity oxy-fuel approach (HVOF). The microstructure, mechanical properties and elevated temperature erosion behavior of post-processed coatings and as-sprayed IN30ALcoatings were investigated. The elevated temperature erosion studies on IN30AL coatings both as-sprayed and post-processed were investigated at 900 °C temperature at two impact angles 30° and 90° using standard high temperature erosion test rig. Phase composition, interface of substrate/coating, and morphologies of eroded coatings were examined using x-ray diffraction, x-ray maps, scanning electron microscope, & energy dispersive spectrometer techniques. Compared with the as-sprayed IN30AL coatings, the heat-treated coatings have refined microstructure, better mechanical properties which improve the elevated temperature erosion resistance of IN30ALcoatings.

Unexpected Ag-H bond in the predictive silver hydride phase under high pressure

Silver, typically acknowledged for its inertness toward hydrogen under standard conditions, exhibits a noteworthy shift in reactivity under elevated pressures. Employing first-principles variable-composition evolutionary search calculations, our investigation unveils the presence of thermodynamically stable Ag-H compounds. A novel stoichiometry, Ag2H, characterized by P3¯m1 symmetry, emerges as the thermodynamically stable phase at 100 GPa. Notably, the trigonal-Ag2H phase at 100 GPa demonstrates both mechanical and dynamic stability, as ascertained through the computation of elastic constants and phonon dispersions, respectively. Examination of the electronic band structure and density of states manifests the metallic nature of the resulting Ag2H compound. A comprehensive analysis involving crystal orbital bond index, Bader charge, and charge density plots substantiates the ionic character of Ag2H, attributable to effective charge transfer from silver atoms to hydrogen. Furthermore, application of the Allen-Dynes modified McMillan equation indicates the absence of superconducting behavior in Ag-H systems at the elevated pressure of 100 GPa.