Transfer Method Research Articles

An End-User Evaluation of Blast Overpressure and Accelerative Impact Body-Worn Sensors.

Blast overpressure and accelerative impact can produce concussive-like symptoms in service members serving both garrison and deployed environments. In an effort to measure, document, and improve the response to these overpressure and impact events, the U.S. Army Medical Material Development Activity is evaluating body-worn sensors for use by the Joint Conventional Force. In support, the WRAIR completed a qualitative end-user evaluation with service members from high-risk mission occupational specialties to determine the potential needs, benefits, and challenges associated with adopting body-worn sensors into their job duties. WRAIR staff led hour-long semi-structured focus groups with 156 Army, Navy, and Marine Corps participants, primarily representing infantry, combat engineer, explosive ordnance disposal, artillery, mortar, and armor job specialties. Topics included their sensor needs, concepts of operations, and recommended design features for implementing sensors into the force. Dialogue from each focus group was audio recorded and resulting transcripts were coded for thematic qualitative analysis using NVivo software. Users recommended a single, unobtrusive, rugged, multi-directional sensor that could be securely mounted to the helmet and powered by a battery type (such as rechargeable lithium or disposable alkaline batteries) that was best suited for their garrison and field/deployed environments. The sensors should accurately measure low-level (∼1.0 pounds per square inch) blasts and maintain a record of cumulative exposures for each service member. Discussions supported the need for immediate, actionable feedback from the sensor with the option to view detailed blast or impact data on a computer. There were, however, divergent opinions on security issues regarding wireless versus wired data transfer methods. Participants also expressed a need for the exposure data to integrate with their medical records and were also willing to have their data shared with leadership, although opinions differed on the level of echelon and if the data should be identifiable. Regarding accountability, users did not want to be held fiscally liable for the sensors and recommended having the unit be responsible for maintenance and distribution. Concerns about being held fiscally liable, being overly burdened, and having one's career negatively impacted were listed as factors that could decrease usage. Finally, participants highlighted the importance of understanding the purpose and function of the sensors and supported a corresponding training module. Participating service members were generally willing to adopt body-worn sensors into their garrison and deployed activities. To maximize adoption of the devices, they should be convenient to use and should not interfere with service members' job tasks. Providing a clear understanding of the benefits (such as incorporating exposure data into medical records) and the function of sensors will be critical for encouraging buy-in among users and leaders. Incorporating end-user requirements and considering the benefits and challenges highlighted by end users are important for the design and implementation of body-worn sensors to mitigate the risks of blast overpressure and accelerative impact on service members' health.

The Impact of Land Transfer on Sustainable Agricultural Development from the Perspective of Green Total Factor Productivity

China’s agricultural sector is transitioning from extensive management to intensive management, and land transfer brings about changes in land use and management methods, which may encourage the agricultural sector to enter a sustainable development track, but this mechanism has not been effectively proven. Using the SBM-GML index to construct a green total factor productivity index to measure the level of sustainable agricultural development in each province (or autonomous region or municipality directly under the central government) and provincial panel data from 2010 to 2022, we applied a panel interactive fixed-effects model to empirically test the impact of land transfer on sustainable agricultural development, with a focus on analyzing the heterogeneity and related mechanisms of this impact. The results indicate that (1) land transfer significantly promotes sustainable agricultural development, and this conclusion still held true after robustness tests such as controlling for regional omitted variables, replacing dependent variables, changing the sample size, IV estimation, and GMM estimation. (2) The mechanism testing found that land transfer mainly promotes sustainable agricultural development by increasing the desirable output, and has no significant effect on reducing non-point source pollution. At the same time, land transfer mainly improves the desirable output through factor allocation effects rather than scale operation effects, thereby promoting sustainable agricultural development. (3) The heterogeneity analysis found that the higher the quantile of agricultural development level is, the weaker the role of land transfer in promoting sustainable agricultural development, indicating that land transfer has a greater impact on areas with poor agricultural development foundations, and areas with poor agricultural development foundations are more likely to obtain sustainable development space through land transfer. The impact of different land transfer methods and land transfer objects on sustainable agricultural development was heterogeneous. Compared with non-market transfer methods such as exchange and transfer, market-oriented transfer methods such as leasing and equity had a more significant impact on sustainable agricultural development. Compared to transferring land to ordinary farmers, transferring land to new business entities such as family farms, professional cooperatives, and enterprises can significantly promote sustainable agricultural development.

Land use transformation by urban informal settlements and ecosystem impact

The rapid expansion of informal settlements poses significant challenges to urban ecosystems and their services, a pressing issue that this study addresses by examining its impacts in Addis Ababa. This study delves into the impact of informal settlements on ecosystem services in Addis Ababa, comparing them with formal settlements. Utilizing geographic information systems (GIS) and remote sensing, it employed Landsat imagery, aerial photography, and base maps to track spatiotemporal changes and analyze trends. Through a GIS overlay approach, informal settlements and associated land use changes were identified, while the benefit transfer method assessed ecosystem service values. The findings revealed a significant increase in informal settlements on the city’s outskirts, expanding from 77 ha in 2009 (2% of the total area) to 765.6 ha in 2023 (21% of the total area). Nearly half (48.5%) of these informal settlements were established on previously natural land covers through encroachment. The research highlighted the ongoing conversion of agricultural land, forests, and urban green spaces into informal settlements, particularly on the city’s outskirts, leading to significant encroachment on these areas. This transformation caused an annual loss of $1,665,033.7 in ecosystem services from 2009 to 2023. Significant impacts were identified on food production, climate regulation, and habitat ecosystem services. Overall, the annual loss in ecosystem services due to land use changes amounted to $1,933,320.08. Informal settlements accounted for 86.1% of this total loss, highlighting the urgent need for targeted interventions to mitigate their disproportionate effects on ecosystem services. The study underscores the urgency of addressing the impact of informal settlements on ecosystem services through effective urban planning, sustainable land management practices, prevention of encroachment on natural land covers, and promotion of sustainable ecosystem management and utilization.

Advances in manufacturing chimeric antigen receptor immune cell therapies.

Biomedical research has witnessed significant strides in manufacturing chimeric antigen receptor T cell (CAR-T) therapies, marking a transformative era in cellular immunotherapy. Nevertheless, existing manufacturing methods for autologous cell therapies still pose several challenges related to cost, immune cell source, safety risks, and scalability. These challenges have motivated recent efforts to optimize process development and manufacturing for cell therapies using automated closed-system bioreactors and models created using artificial intelligence. Simultaneously, non-viral gene transfer methods like mRNA, CRISPR genome editing, and transposons are being applied to engineer T cells and other immune cells like macrophages and natural killer cells. Alternative sources of primary immune cells and stem cells are being developed to generate universal, allogeneic therapies, signaling a shift away from the current autologous paradigm. These multifaceted innovations in manufacturing underscore a collective effort to propel this therapeutic approach toward broader clinical adoption and improved patient outcomes in the evolving landscape of cancer treatment. Here, we review current CAR immune cell manufacturing strategies and highlight recent advancements in cell therapy scale-up, automation, process development, and engineering.

Manipulating energy transfer to achieve zero-thermal quenching luminescence in a white-emitting borotellurate phosphor

Energy transfer-induced white-emitting phosphor materials acquired much attention in white light-emitting diode (w-LED) domain. Nevertheless, how to obtain extremely high thermostable luminescence is one of the troubles, which is urgently solved. Diverse strategies were proposed to improve thermal quenching resistance of w-LED phosphors. Herein, a Tm3+−Dy3+ energy transfer (ET) method is manipulated to simultaneously achieve white-emitting and zero-thermal quenching luminescence in Na2Y2TeB2O10 (NYTB), which is constructed via the co-substitution of Tm3+/Dy3+ for Y3+. The ET mechanism and efficiency are determined. The color coordinates (0.3545, 0.3334) of the representative NYTB:0.07Tm3+,0.05Dy3+ phosphor closely resemble (0.33, 0.33) for the standard white light. It is employed to fabricate a w-LED device with low CCT. This work offers an in-depth insight of ET strategy for both obtaining white-emitting and developing extremely high thermostable luminescence.

Innovative reinforcement method for metal foam cell wall using CNTs

Carbon nanotubes (CNTs) and their composites are gaining popularity due to their exceptional strength qualities. It is well known that adding CNTs to metal foam composites boosts compressive strength. On the other hand CNT addition is still a costly process due to high cost of the CNTs. This study presents a novel and cost-effective solution by selectively adding CNTs to the structurally weakest regions of aluminum foam materials produced via powder metallurgy, employing a newly developed focused multi-step additive method. The cell borders of aluminum foam are strengthened with multiple spherical layers of CNTs, using a transfer method by initially coating the space holders used at the foaming process. The strength increase effect of this CNT addition method was compared with the widely known aluminum foam production parameters via a 4-parameter design of experiment (DOE) study. Compressive strength values of the samples were evaluated using a constant speed compression test acc. to ISO13314. The compacting pressure, CNT concentration, sintering temperature, and sintering period were chosen as DOE parameters, and 78% of the interactions effecting on final compressive strength could be explained with the model. As a result, it was established that, compared to the other parameters, sintering duration had the highest influence on compressive strength. But besides It has also been shown that adding 0.53% CNT by weight only to the cell border regions increases overall strength by 9%. This weight-strength increase ratio is compared with similar studies in the literature and found to be providing a production cost advantage due to the lower amount of CNT addition requirement for the comparable weight relative strength increase. Focused strength increase method has potential to enable controlled failure of foam materials by selectively strengthening strength critical areas of a component.

An unmanned aerial system benchmark object detection dataset for deep learning in outfall surveys

ABSTRACT Deep-learning-based object detection in UAS imagery is crucial for outfall surveys and basin environmental protection. Comprehensive UAS image datasets serve as a foundation for creating deep-learning-based outfall-detection models and evaluating outfall-detection algorithms. However, existing remote sensing deep learning datasets lack specific outfall data. This study introduces a benchmark UAS image dataset of outfalls, categorized into three main and seven subcategories. Over 10,000 labeled images were collected from UAS images with a 10 cm resolution for the Yangtze River, Yellow River, and other basins from 2019 to 2022, covering nearly all types of outfalls in China. Each sample was matched with digital surface model (DSM) data generated through photographometry or the DSM transfer method. Evaluation with seven widely used deep learning-based object detection algorithms demonstrated the dataset's viability, achieving an average precision ( A P 50 ) of 64.6, surpassing performance on Microsoft Common Objects in Context. Further experiments indicated that DSMs attached to this dataset could benefit from geo-deep-learning-based object detection algorithms for outfalls, achieving an A P 50 exceeding 70. This study presents a UAS benchmark image dataset for outfall surveys, potentially advancing the application of deep learning in environmental protection.

Cyclododecane-based high-intactness and clean transfer method for fabricating suspended two-dimensional materials

The high-intactness and ultraclean fabrication of suspended 2D materials has always been a challenge due to their atomically thin nature. Here, we present a universal polymer-free transfer approach for fabricating suspended 2D materials by using volatile micro-molecule cyclododecane as the transfer medium, thus ensuring the ultraclean and intact surface of suspended 2D materials. For the fabricated monolayer suspended graphene, the intactness reaches 99% for size below 10 µm and suspended size reaches 36 µm. Owing to the advantages of ultra-cleanness and large size, the thermal conductivity reaches 4914 Wm−1K−1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\rm{W}}\\,{{\\rm{m}}}^{-1}{{\\rm{K}}}^{-1}$$\\end{document} at 338 K. Moreover, this strategy can also realize efficient batch transfer of suspended graphene and is applicable for fabricating other 2D suspended materials such as MoS2. Our research not only establishes foundation for potential applications and investigations of intrinsic properties of large-area suspended 2D materials, but also accelerates the wide applications of suspended graphene grid in ultrahigh-resolution TEM characterization.

The Impact Analysis on Productivity Enhancement of Blackgram through Front Line Demonstration in Chandel District of Manipur State

Background: Blackgram is the major pulse crop cultivated all over the India. The crop is resistant to unfavourable weather patterns and helps in enhancing soil fertility. It is a significant component of the Indian diet since it provides vegetable protein and balances the diet. About 26 per cent of it is protein, which is nearly three times more than cereal and other vitamins and minerals. In addition, it is utilised as nutrient-rich fodder, particularly for dairy cattle. A significant obstacle to expanding blackgram production in Chandel district, Manipur State is the technology gap. Frontline demonstration (FLD), is one of the most significant and effective methods for technology transfer. By using the newest technologies, Krishi Vigyan Kendra Chandel’s interventions aim to boost productivity and production. Methods: The study on Blackgram var. PU-31 under rainfed farming situations of Chandel district, Manipur was carried out by ICAR-Krishi Vigyan Kendra-Chandel, during Kharif 2017 to 2022 with the objectives to increase production and productivity of pulse in the district conducted in the farmers’ field for 118 hectares of land with all the scientific package of practices. Result: The average grain yield of 776.50 kg/ha was obtained in the demonstration plot with 38.13 per cent increase in yield over farmers practices. The technological and extension gap were 723.50 kg/ha and 214.33 kg/ha respectively. Similarly, technological index was decreased from 50.33 percent to 44.53 percent during the study period, revealing satisfactory performance of technological interventions which can further be improved by bridging the gaps with more efficient research and extension services.

Impact on bandgap, electrical and magnetic properties of SnO2 nanoparticles by cerium and samarium

Synthesis of undoped, Samarium (Sm) and Cerium (Ce) co-doped SnO2 nanoparticles along with their enhancement in structural and physicochemical properties are reported. The samples have been prepared by co-precipitation method. The tetragonal rutile-type structure from PXRD pattern confirms the synthesized materials and obtained an average crystallite size of 23, 19 and 14 nm for the pure, 2 and 4 wt.% of Sm-Ce co-doped SnO2 NPs. The band at 620 cm−1 is assigned to the bonding of metal-oxygen as O-Sn-O bridging bond of SnO2 through FTIR-spectrum. From UV–DRS analysis, bandgap energy is found to be 3.45, 3.38 and 3.26 eV respectively for pure, 2 & 4 wt.% of Sm-Ce co-doped SnO2 NPs. Photoluminescence emission shows a sharp peak centered at 490 nm, a high intensity peaks at 521 and 538 nm due to blue and green emission. Addition of dopants narrowing the bandgap and reduces the dielectric constant as well as the dielectric loss. The dielectric constant and dielectric loss are directly proportional to temperature but inversely proportional to frequency, which shows that both polarizability and the method of charge transfer are impacted by the space charge polarization, which made the material could be a potential candidate in spintronics and high-performance dielectric materials. The effect of Sm-Ce co-dopants enhances the saturation magnetization value from 0.0049067 emu/g to 0.0072245 emu/g. The results exhibit that Sm-Ce (4 wt.%) co-doped SnO2 nanoparticles have strong dielectric and magnetic properties which is a potential candidate for spintronic devices.

A clean transfer approach to prepare centimetre-scale black phosphorus crystalline multilayers on silicon substrates for field-effect transistors

Recently reported direct growth of highly crystalline centimetre-sized black phosphorus (BP) thin films on mica substrates by pulsed laser deposition (PLD) has attracted considerable research interest. However, an effective and general transfer method to incorporate them into (opto-)electronic devices is still missing. Here, we show a wet transfer method utilizing ethylene-vinyl acetate (EVA) and an ethylene glycol (EG) solution to transfer high-crystalline large-area PLD-BP films onto SiO2/Si substrates. The transferred films were used to fabricate BP-based bottom-gate field-effect transistor (FET) arrays exhibiting good uniformity and continuity, with carrier mobility and current switching ratios comparable to those obtained in as-grown BP films on mica substrates. Our work presents a promising transfer strategy for scalable integration of on-substrate grown 2D BP into devices with more complex structures and further investigation of material properties.

Cryogenic Atom Probe Tomograph to Resolve Confined Electrochemical Interfaces

Atom Probe Tomography (APT) is an analysis technique capable of providing a 3-dimensional, element-sensitive map of needle-shaped samples (where the tip radius is about 50 nm) with sub-nanometre resolution [1]. APT analysis is carried out at temperatures in the range of 25-75 K to limit the thermal motion of surface atoms which improves the spatial and mass resolution. As a result, this enables the analysis of frozen liquids, and by extension solid-liquid interfaces, by so-called “cryo-APT”. While this was historically challenging, recent advancements in UHV-cryogenic transfer and sample preparation methods now make it possible for the atomic scale analysis of interfacial species in electrochemical systems [2-4].In this study, we will attempt to explore the effect of nanoscale geometrical confinement on the distribution of interfacial ions for the first time and to resolve the electric double layer, using cryo-APT. We will describe the workflow for cryo-APT sample preparation to study confined solid-liquid interfaces, using nanoporous gold as a template material with a frozen sodium iodide solution inside its pores. APT reconstructions will allow 3-dimensional mapping of aqueous interfacial species, helping to develop our understanding of the structure of the electric double layer under nanoscale geometrical confinement. The attached Figure shows an SEM image of the later stages of cryo-FIB milling of an APT tip of frozen deionised water and 50 mM sodium iodide and a segment of the related APT atom map reconstruction.

Polarization Characteristics of Massive HVI Debris Clouds Using an Improved Monte Carlo Ray Tracing Method for Remote Sensing Applications

As a signature phenomenon of massive hypervelocity impacts (HVIs) in space, debris clouds provide critical optical information for satellite remote sensing and the assessment of large-scale impacts. However, studies of the optical scattering properties of debris clouds remain limited, and existing vector radiative transfer (VRT) methods struggle to accurately simulate the optical characteristics of these complex scatterers. To address this gap, this paper presents an improved Monte Carlo VRT program (PGS–MC) for multicomponent polydisperse scatterers to precisely evaluate the radiation and polarization characteristics of complex scatterers. Based on the Monte Carlo ray tracing (MCRT) method, our program introduces a particle grouping strategy (PGS) to further emphasize the importance of accounting for optical property discrepancies between different materials and particle sizes, thus significantly improving the fidelity of VRT simulations. Moreover, our program, developed using the compute unified device architecture (CUDA), can be run parallelly on graphics processing units (GPUs), which effectively reduces the computational time. The validation results indicated that the developed PGS–MC program can accurately and efficiently simulate the polarization of complex 3D scatterers. A further investigation showed that the polarization characteristics of debris clouds are highly sensitive to parameters such as the angle between the incident and detection directions, number density, particle size distribution, debris material, and wavelength. In addition, the polarization imaging of debris clouds offers distinct advantages over intensity imaging. This study offers guidance for analyzing the VRT properties of massive HVI debris clouds. Additionally, it provides a practical tool and concrete ideas for modeling the polarization characteristics of various complex scatterers, such as aircraft contrails and clouds, etc.

(Invited) A Neural Compact Model Based on Transfer Learning for Organic FETs

Organic field-effect transistors (organic FETs) exhibit highly non-linear electrical characteristics due to their distinctive transport mechanism manifested by thermally-assisted hopping via localized states randomly distributed in both energy and space domains. This feature impedes the establishment of an analytical compact model. In this context, we present an approach to adopt artificial neural networks (ANN) for the development of a compact model, namely a neural compact model, by exploiting the powerful ability of the ANN to describe a non-linear function accurately. In addition, we evaluate the knowledge transfer method to reduce learning time and improve accuracy even when the data is scarce and costly. By technology computer-aided design simulation, we constructed a dataset of electrical characteristics of organic FETs with Gaussian disorder which is calibrated to the experimental measurement. Subsequently, we constructed and compared neural compact models based on conventional deep learning and transfer learning. We showed that the neural compact model with transfer learning provides an equivalent accuracy at a shorter modeling time. A complex dependence on the gate voltage, drain voltage, and temperature is successfully modeled over a wide range of operation regimes and temperatures.

Enhancing PEMFC Performance: Optimization of Hot-Pressed Decal Transfer Conditions for MEA Fabrication

Proton exchange membrane fuel cells (PEMFCs) hold significant promise in curbing greenhouse gas emissions within the transportation sector. While historically more expensive than conventional internal combustion engines, the cost per kW is poised to significantly drop as production volumes increase and the adoption of fuel cell electric vehicles progresses [1]. In heavy-duty vehicle applications, predictions suggest that hydrogen fuel cells will achieve a cost equivalence with diesel, potentially becoming the most cost-effective option when evaluating the total ownership expenses [2]. Membrane-electrode-assemblies (MEAs) serve as the core of fuel cells, where all reactions—proton and electron generation, distribution, and consumption occur. Their efficiency dictates both cell performance and lifespan. Various methods for fabricating MEAs have been developed, including decal transfer, catalyst-coated membrane (CCM), and catalyst-coated gas diffusion layer (CCG) techniques. Among these, the decal transfer method is widely regarded as the most appropriate for large-scale production of MEAs [3]. This study delves into an examination of diverse hot-pressed decal transfer conditions for the preparation of MEAs tailored for PEMFC application. Our investigation involves fabricating MEAs through hot-press decal transfer at temperatures spanning 115°C to 145°C and pressures ranging from 200 psi to 400 psi, each held for a 5-minute duration. Electrochemical characterizations were performed within a single-cell setup to assess MEA performance. Moreover, an accelerated stress test (AST) was carried out to scrutinize the stability of the fabricated MEAs concerning their decal transfer conditions and morphological variations. Our study extensively explored catalyst layers transferred under diverse hot-pressed decal transfer conditions, focusing on their fuel cell performance and transport properties. To comprehensively understand the influence of morphological alterations on electrochemical characteristics, additional morphological characterizations, including white light interferometer (WLI) imaging, field emission scanning electron microscopy (FESEM), Brunauer-Emmett-Teller (BET) surface area analysis, and nano-computed tomography (Nano-CT) were employed for MEA evaluation. Our findings indicate that the MEA produced at 145°C and 200 psi exhibited superior performance in both pre- and post-AST testing. Comprehensive experimental results and insights will be elaborated upon during the conference presentation.

Transport Effects in Electrochemical Biochip Sensors with Redox Cycling Amplification: Computational and Experimental Analysis

In the last few decades, and especially after the COVID-19 pandemic, point-of-care diagnostics and field-deployable biosensors have attracted significant attention. Key components of these instruments are microchips that integrate microfluidics with a sensor (e.g., optical or electrochemical) to provide rapid, low-cost, real-time detection of analyte molecules in very small volumes. Next-generation electrochemical sensors have been miniaturized on solid-state platforms (e.g., arrays and vectors) where the area is limited. However, as the active surface area of the sensors decreases from a few square microns to sub-micron and nanometric scales, the measured currents drop, hence affecting the limit of detection. As the concentration of many analytes in the physiological environment is low, low signal-to-noise ratios have limited the miniaturization of standard electrochemical sensors. One way to increase signal at the sensor output is by redox amplification. To achieve amplification, a second working electrode must be incorporated close to the first working electrode and proper bias must be applied to both. Micrometer-sized interdigitated electrode arrays have been fabricated using robust and scalable processes based on optical lithography and reactive ion-etching techniques. In some cases, IDAs have been integrated into microfluidics devices. The physical and electrochemical phenomena that occur in microfluidic channels under flow have been previously evaluated and showed an increase of current under flow. The effect of redox cycling in microfluidic and nanofluidic systems has also been qualitatively demonstrated. Some studies measured the amplification in the cases with and without flow and showed that the flow itself amplifies the measured electrochemical current, though in most cases, it reduces the amplification factor.Towards a more quantitative investigation, analytical and computational modeling were used, providing meaningful insights into the physics of IDAs without requiring numerous device fabrications. In this work, we used COMSOL Multiphysics to create a full three-dimensional simulation-based model of a real device in order to study the effect of laminar flow on redox cycling, as well as a simplified one-dimensional model for the analysis of transition velocity between different amplification regimes. IDAs with 5-10 mm for both electrodes width and gap were studied numerically and experimentally. The results of the 3D and 1D simulations were consistent between themselves, and also with those of the physical experiments. The relationship between the two mass transfer methods — diffusion and convection — were analyzed at different flow velocities and for different electrode geometries.Here we report a study of transport effects on a microfluidic sensor-chip in which electrochemical sensing is amplified by redox cycling using an interdigitated electrode array (IDA). Our models indicate that there exist two dominant regimes: one which is limited by redox cycling diffusion—a unique feature of IDAs— which is dominant at relatively low flow rates, and another which is limited by convection and has dominant flow effects which are effective at high flow rates (see Figure). The transition velocity between the two sensing regimes depends on the width of the electrode and spacing. It was found to be Vflow [mm/sec]=0.335/L[μm] + 0.04 which is similar to the prediction of Vflow∝1/L obtained from the one-dimensional model.An understanding of the combined effects of redox cycling and convection flow is critical as microfluidic chips with electrochemical sensing amplified by redox cycling using IDAs are becoming widely used in diagnostic assays. The method for prediction of current under any flow rate described here will support technological development of more efficient and accurate devices. Figure 1

Dissolution Stability of Graphene-Modified Pt(111)

Pt plays a leading role in electrocatalysis, being the best pure metal catalyst for the oxygen reduction reaction (ORR) taking place at the cathode of the commercial polymer electrolyte membrane fuel cells (PEMFCs). In addition, it is usually used in the cathode to catalyze the hydrogen evolution reaction (HER) in water electrolyzers for hydrogen production. Apart from activity, stability is another critical parameter to consider when evaluating the performance of electrochemical energy conversion devices. Even pure Pt catalysts degrade under real-life conditions due to electro-oxidation and dissolution processes. Fundamental studies with well-defined Pt surfaces are mandatory for understanding these phenomena and developing new electrocatalysts with improved activity and stability.1 Different types of protection on the surface of electrocatalysts, such as carbon layers or ceria surrounding metal nanoparticles,2-4 have been investigated to enhance their stability while maintaining or improving their activity towards a reaction of interest. Here, we propose the modification of Pt(111) single crystal electrode with an adlayer of graphene as a model system to evaluate the protection mechanism of carbon-capped catalysts.In this work, the stability of graphene-modified Pt(111) in 0.1 M HClO4 is studied by on-line inductively coupled plasma mass spectrometry (ICP-MS) measurements using an electrochemical scanning flow cell (SFC). The Pt(111) surface was modified by a fast and easy transfer method of a commercially available chemical vapor deposited (CVD) graphene single-layer. The cyclic voltammetry results are comparable to those previously reported for surfaces prepared by direct CVD on the Pt(111) electrode.5 To test the quality of the graphene adlayer we checked the electrocatalytic activities towards different reactions of interest, such as ORR, HER and hydrogen oxidation reaction (HOR), and compared the results with the previous works.6 The graphene-modified Pt(111) surface presents enhanced stability since no dissolution is detected for a cyclic voltammetry experiment at 10 mV s-1 with an upper potential limit (UPL) of 1.3 V vs. RHE. In contrast, evident Pt dissolution is observed for the unmodified surface. Different accelerated stress test (AST) protocols consisting in groups of 50 cyclic voltammetries at 200 mV s-1 were performed up to three different UPL, namely 1.3 V, 1.5 V and 1.7 V vs. RHE, showing almost no dissolution over the protocol when UPL = 1.3 V, while the integrity of the graphene adlayer was quickly compromised for UPL = 1.7 V as pointed out by the quick increase in Pt dissolution. The degradation of the graphene layer in the different conditions was additionally characterized by Raman spectroscopy and atomic force microscopy (AFM). The results from this work provide useful information about the behavior of carbon capping agents on Pt surfaces, which can help to design new electrocatalytic materials with improved stability. References (1) Fuchs, T.; Briega-Martos, V.; Drnec, J.; Stubb, N.; Martens, I.; Calle-Vallejo, F.; Harrington, D. A.; Cherevko, S.; Magnussen, O. M. Anodic and Cathodic Platinum Dissolution Processes Involve Different Oxide Species. Angew. Chem. Int. Edit. 2023, 62, e202304293.(2) Sgarbi, R.; Doan, H.; Martin, V.; Chatenet, M. Tailoring the Durability of Carbon-Coated Pd Catalysts Towards Hydrogen Oxidation Reaction (HOR) in Alkaline Media. Electrocatalysis 2023, 14 (2), 267-278.(3) Kim, H.; Kwon, G. H.; Han, S. O.; Robertson, A. Platinum Encapsulated within a Bacterial Nanocellulosic-Graphene Nanosandwich as a Durable Thin-Film Fuel Cell Catalyst. ACS Appl. Energy Mater. 2021, 4 (2), 1286-1293.(4) Miller, H. A.; Vizza, F.; Marelli, M.; Zadick, A.; Dubau, L.; Chatenet, M.; Geiger, S.; Cherevko, S.; Doan, H.; Pavlicek, R. K.; et al. Highly active nanostructured palladium-ceria electrocatalysts for the hydrogen oxidation reaction in alkaline medium. Nano Energy 2017, 33, 293-305.(5) Fu, Y. C.; Rudnev, A. V.; Wiberg, G. K. H.; Arenz, M. Single Graphene Layer on Pt(111) Creates Confined Electrochemical Environment via Selective Ion Transport. Angew. Chem. Int. Edit. 2017, 56 (42), 12883-12887.(6) Shih, A. J.; Arulmozhi, N.; Koper, M. T. M. Electrocatalysis under Cover: Enhanced Hydrogen Evolution via Defective Graphene-Covered Pt(111). ACS Catal. 2021, 11 (17), 10892-10901.

High-Q film bulk acoustic resonator with high quality AlN film based on transfer method

Thin film bulk acoustic resonator (FBAR) with high quality factor (Q) is preferred for many communication applications. AlN film deposited in conventional FBAR fabrication process is poor, resulting in unsatisfactory device performance. This study demonstrated the comparison of two Si-substrate FBARs, adopting the same AlN deposition process by physical vapor deposition (PVD) method, however using different device fabrication method. Instead of depositing AlN film on Mo/SiO2/Si substrate in existing fabrication process, we deposited AlN directly on Si substrate by PVD to get better crystal quality piezoelectric layer of the FBAR. The full width at half maximum (FWHM) of rocking curve and surface roughness of AlN directly deposited on Si substrate are 1.4° and 1.96 nm, while those of AlN deposited on Mo/SiO2/Si substrate are 8.5° and 5.54 nm, respectively, indicating AlN deposited directly on Si substrate has a better crystal quality than that on Mo/SiO2/Si substrate. The dielectric loss of FBAR using AlN developed on Si substrate decreases from 0.4 Ω to 0.11 Ω leading to the increase of Q m from 470 to 830. By preserving the high quality AlN deposited on Si substate with film transfer method, the FBAR device enjoys an increasing of Q-values as high as 76%.

Extended perilune rendezvous method for low Delta-V transition to NRHO for cargo transportation mission to gateway

The construction of Gateway in lunar orbit is planned as a post-ISS mission by NASA, and JAXA is considering a cargo supply mission to provide service. The Near-Rectilinear Halo Orbit (NRHO) is a candidate for a Gateway orbit, and several methods for the transfer trajectory are being researched. The In-Direct Transfer (IDT) has a short transition period of seven days, but the ΔV application is inefficient. The Weak Stability Boundary (WSB) transfer maintains a small ΔV, but the transition takes over 100 days. However, a trajectory intermediate between IDT and WSB has not yet been actively studied. This paper proposes the Extended Perilune Rendezvous Method (EPRM) of intermediate transfer to NRHO. This method reduces ΔV by orbiting in an elliptical lunar orbit for over two weeks. EPRM has several transition methods corresponding to ΔV and transition periods. This paper systematically reveals the transition mechanisms. Moreover, an effective TCM, considering several error types, is presented for an actual mission. Finally, the rendezvous accuracy with Gateway is discussed.

Reproductive outcomes in women with advanced endometriosis in fresh versus frozen embryo transfer cycles

BackgroundART in women with endometriosis is associated with poor quality of the retrieved oocytes and lower fertilization and pregnancy rates, reflecting that endometriosis may influence fertility by altering the quality of both the oocyte and embryo quality and also by impairing the endometrial receptivity. On comparing endometriosis-affected patients to healthy counterparts, many differences were demonstrated at the endometrial level. Thus, choosing the appropriate method of embryo transfer is of utmost importance, particularly for patients with advanced endometriosis.ObjectiveThe aim of the present study was to compare the reproductive outcomes between fresh and frozen embryo transfer cycles in women with advanced endometriosis.Material and methodsA retrospective cohort study was conducted in the period from January 2018 until December 2021 for patients recruited from two IVF centers, Alexandria, Egypt. Careful review of paper and electronic medical records of infertile women (primary, relative, or secondary infertility) aged 18–37 years who were diagnosed with advanced endometriosis by means of laparoscopy and were scheduled for ICSI followed by either fresh embryo transfer (group I) or freeze-all embryos and deferred embryo transfer (group II) of day 5 embryo(s) was included in the study.ResultsTwo-hundred and eleven women were eligible and included in the study. Women in each study group were matched regarding baseline characteristics. Clinical pregnancy, implantation, and ongoing pregnancy rates were statistically significantly higher in the group of frozen embryo transfer (p < 0.001). Miscarriage rate was found to be higher in the group of fresh transfer compared to FET group but without a statistical significance (20.9% vs 9.2%, p = 0.072).ConclusionIn women with advanced endometriosis, freeze-all policy seems to be associated with better implantation, ongoing pregnancy rates.