Additive Channel Research Articles

Microwave radiation of space and prospects for its use in quantum propulsors

Using the original approach developed in recent years – supramolecular physics of the environment, the results of considering the contribution of physical optics processes to the formation of induced microwave radiation are presented.The two most powerful cosmic thermal sources: the background (relict) flux in the absolute millimeter maximum of the spectrum, and the mm-wave radio flux from Sun are considered. The postulate of A. Einstein about the emergence of an induced emission quantum in a medium with established thermal equilibrium is taken into account. This made it possible to quantitatively substantiate, based on the principles of the similarity theory of G.S. Golitsyn, a scheme for the use of microwave energy of the interstellar/interplanetary medium during space flights. Based on the physics of collisions, in the proton transfer reaction of the main simple hydrides in interstellar/interplanetary molecular clouds, it is proposed to take into account the possibility of the manifestation of an additional channel for the maser effect in such a medium (first considered by V.A. Ambartsumian in 1979) due to the close location of electronically excited Rydberg levels for molecules in these clouds. The pioneering work of N.S. Kardashev on the study of Rydberg transitions during the emission of recombination radio lines was taken into account. Due to the efforts of astronomers from the Lebedev Physical Institute and the State Astronomical Observatory of the Russian Academy of Sciences (at Pulkovo), this work led to the discovery of the microwave flux from deep space objects. Real energy and schemes for using a microwave quantum propulsor device with the ability to choose the direction of flights are discussed.

Chat messenger use in the care of patients with Parkinson's disease

The demand for chat messaging apps for communication between physicians, therapists and patients is increasing. The expectations for this form of communication and uncertainties regarding introduction and use are heterogeneous. The implementation of chat messengers in the care of patients with Parkinson's disease should be facilitated by recommendations regarding introduction and usage. Semi-structured interviews with neurologists and physiotherapists were conducted to capture the expectations and needs regarding the use of chat messengers. From the data analysis, recommendations were derived. The expectations for technical functionality exceeded the chat messenger functions. This concerns, e.g., the connection of the chat messenger to the electronic patient file. There is agreat deal of uncertainty, particularly when it comes to the applicable General Data Protection Regulations (GDPR). The recommendations relating to the use of chat messengers, data protection aspects, the design of such tools and methodological considerations can help to implement the tool as an additional communication channel. Practical recommendations regarding functionality, the use of chat messengers in everyday life and in relation to data protection are derived from the results. By improving knowledge, physicians and therapists can contribute to the successful establishment of chat messengers as an additional communication tool.

Oxidizing Role of Cu Cocatalysts in Unassisted Photocatalytic CO2 Reduction Using p-GaN/Al2O3/Au/Cu Heterostructures.

Photocatalytic CO2 reduction to CO under unassisted (unbiased) conditions was recently demonstrated using heterostructure catalysts that combine p-type GaN with plasmonic Au nanoparticles and Cu nanoparticles as cocatalysts (p-GaN/Al2O3/Au/Cu). Here, we investigate the mechanistic role of Cu in p-GaN/Al2O3/Au/Cu under unassisted photocatalytic operating conditions using Cu K-edge X-ray absorption spectroscopy and first-principles calculations. Upon exposure to gas-phase CO2 and H2O vapor reaction conditions, the composition of the Cu nanoparticles is identified as a mixture of CuI and CuII oxide, hydroxide, and carbonate compounds without metallic Cu. These composition changes, indicating oxidative conditions, are rationalized by bulk Pourbaix thermodynamics. Under photocatalytic operating conditions with visible light excitation of the plasmonic Au nanoparticles, further oxidation of CuI to CuII is observed, indicating light-driven hole transfer from Au-to-Cu. This observation is supported by the calculated band alignments of the oxidized Cu compositions with plasmonic Au particles, where light-driven hole transfer from Au-to-Cu is found to be thermodynamically favored. These findings demonstrate that under unassisted (unbiased) gas-phase reaction conditions, Cu is found in carbonate-rich oxidized compositions rather than metallic Cu. These species then act as the active cocatalyst and play an oxidative rather than a reductive role in catalysis when coupled with plasmonic Au particles for light absorption, possibly opening an additional channel for water oxidation in this system.

Autonomous self-healing strategy for flexible fiber lithium-ion battery with ultra-high mechanical properties and volumetric energy densities

The development of wearable devices urgently requires flexible, lightweight, and high-performance power solutions. Flexible fiber batteries are flexible and deformable, which holds great potential in this field. However, it still face significant challenges in achieving excellent electrochemical performance and good mechanical properties. Herein, we developed a new method for preparing flexible fiber lithium-ion batteries by surface etching and in-situ chemical cross-linking strategies using direct ink writing-based 3D printing technology. On the one hand, the surface of graphene oxide undergoes oxidation and etching to form pores. This unique pore structure provides additional channels for ions, which increases the ion transmission rate. On the other hand, polyvinyl alcohol/sodium metaborate is introduced into the printing ink/coagulation bath. In-situ chemical cross-linking occurs during the printing and curing process, which exhibits self-healing properties. The flexible fiber electrode has excellent strain (∼30 %) at the macro level, and the assembled fiber lithium-ion battery exhibits impressive volumetric energy density (157.9 mWh cm−3), which exceeds previously reported flexible fiber batteries. And it is also integrated into wearable smart watches for use in daily life. This work proposes an innovative method to fabricate high-performance flexible fiber electrodes, which is of great significance for promoting the development of future portable/wearable electronics.

What does housing collateral mean for Hong Kong economy? From the perspective of modelling and policy implication

This paper studies the housing sector of Hong Kong and the role of collateral constraint in modelling Hong Kong economy, through the lens of a small open economy DSGE model with a currency board exchange rate commitment. By estimating and evaluating the model by Indirect Inference over the sample period of 1994Q1–2018Q3, it is found that the collateral model can match data behaviour. Comparing with the tests generated from the model without collateral, collateral model can match the housing price data better, while the model without collateral fits the general price better. Since collateral constraint acts like an additional transmission channel, it enhances the impact from shocks and housing price is highly determined by housing demand. We further investigate LTV policy, finding it could be applied as macroprudential policy, especially when addressing the problem caused by increase in the US interest rate and the burst in the domestic housing demand, but the government should watch closely to the crowding out effect from export to housing demand and housing investment.

Gender-based approaches for improving milk safety, value addition, and marketing among smallholder livestock farmers

In the context of Uganda, this study delves into gender-based strategies aimed at enhancing women’s engagement in milk safety, value addition, and marketing within smallholder livestock farming. The objectives were two-fold: first, to document the current practices of women in milk safety, value addition, and marketing channels; second, to examine the constraints, opportunities, and strategies related to the production of safe milk and milk products, along with accessing sustainable markets. Conducted in four sub-counties of the Kiruhura district, this research employed both qualitative participatory methods and structured questionnaires, including 12 focused group discussions and 20 key informant interviews with both women and men. Notably, 217 structured questionnaires were administered. The findings illuminate that women played a central role in milk processing, water provisioning, sanitation, and hygiene practices and were the primary contributors to milk value addition, particularly in the production of butter and ghee. Despite their active involvement, women face challenges in accessing adequate milk quantities, employ traditional labor-intensive procedures, and encounter difficulties in marketing their processed products. Men, often the household heads, held decision-making authority over milk consumption and controlled the selling of milk, contributing to gender disparities. Addressing these challenges necessitates comprehensive support, including training and capacity-building initiatives for both men and women in milk value addition, credit access, and market entry. The study underscores the potential for improved women’s access to milk quantities, particularly for butter and ghee production, to strengthen rural livelihoods and boost dairy production in Uganda.

High permeability Performance TFC Nanofiltration Membrane with Two dimensional Nanochannels Support Layer Fabricated by Dissolving of Nanosheets

A synthesized thin film composite (TFC) nanofiltration membrane was prepared by incorporating Mg(OH)2 nanosheets at different ratios (from 0 to 0.5 wt%) into polysulfone (PSf) support layer. The polypiperazinamide (PPA) layer was prepared on the polysulfone support layer by means of interfacial polymerization. Then TFC membrane was then etched with H2SO4 and a PPA selective layer was established using trimesoyl chloride (TMC) and piperazine (PIP). The characterization results show that the modifications of the PSf substrate with Mg(OH)2 alter the physicochemical properties of the poly(piperazine amide) selective layer. Through the introduction of Mg(OH)2, the hydrophilicity of the TFC membrane was increased (WCA: 20.5°), promoting more linear polypiperinamide. The addition of 0.4 wt% Mg(OH)₂ to the PSf substrate, followed by sulfuric acid etching, resulted in a 196 % increase in membrane flux and with Na₂SO₄ retention at 97.72 %. The change in matrix composition favoured the generation of a lighter and rougher selective layer. The two-dimensional nanochannels in the support layer provided additional channels for water molecule transport. The membrane with two-dimensional nanochannels exhibited excellent resistance to contamination, with a flux recovery of 92.8 % for bovine serum albumin (BSA).

A fully digital timing background calibration algorithm based on first-order auto-correlation for time-interleaved ADCs

This paper presents a fully digital background calibration method for time-interleaved (TI) analog-to-digital converters (ADCs). The timing detector employs a timing detection method based on an enhanced autocorrelation function, combined with matrix operations, to improve the accuracy of timing mismatch acquisition. The algorithm makes full use of the autocorrelation functions of each channel and proposes a more precise method for obtaining autocorrelation derivatives. Furthermore, the algorithm features a simple structure, low computational complexity, and can support timing calibration for any number of channels without requiring additional channels. The algorithm was validated using an ADC + FPGA combined system, with a 8-channel TI-ADC manufactured in 28 nm technology and a sampling rate of 20 GS/s. Results demonstrate that compared to the uncalibrated state, the algorithm significantly improves the SNDR and SFDR from 27.98 dB and 30.76 dB to 39.38 dB and 42.13 dB, respectively when the inputs are near the Nyquist frequency.

High Performance Flexible Supercapacitor Based on Single Precursor Derived NiFe2O4 Spinel with Tailored Cationic Distribution and Oxygen Vacancies in Acidic Medium

AbstractSpinel metal oxides are extensively studied for supercapacitors (SCs) in alkaline electrolytes, where charge storage capacity is limited by surface site availability due to surface reconstruction forming metal hydroxides/oxyhydroxides. The use of an acidic medium, which can boost the charge storage capacity of spinel oxides offering an additional channel of intercalation‐deintercalation of protons, is underexplored. Moreover, the impact of chemical compositions and the cationic distributions is crucial on the electrocatalysis performance of spinel oxides, however, such a correlation is first time reported for charge storage properties of spinel ferrite NiFe2O4 nanoparticles (NFO NPs). Besides, a low‐cost and scalable synthesis of NFO NPs involving the thermal decomposition of Ni‐Fe glycolate, followed by controlled air‐calcination is reported. Thus crafted NFO NPs‐based device shows impressive specific capacitance (2112 F g−1 at 10 A g−1) in half‐cell configuration. A flexible all‐solid‐state asymmetric device (full‐cell) configuration depicts impressive energy density (20.7 Wh kg−1), power density (4000 W kg−1), gravimetric capacitance (140 F g−1 at 2 A g−1), and retention of its performance (≈75% after 10,000 charging/discharging cycles). The results depict a new insight toward the tuning of electronic and charge storage properties in NFO, which otherwise are predominately attributed to only the crystallite size and morphological effects.

Aggregation promotes charge separation in fullerene-indacenodithiophene dyad

Fast photoinduced charge separation (CS) and long-lived charge-separated state (CSS) in small-molecules facilitate light-energy conversion, while simultaneous attainment of both remains challenging. Here we accomplish this through aggregation based on fullerene-indacenodithiophene dyads. Transient absorption spectroscopy reveals that, compared to solution, the CS time in aggregates is accelerated from 41.5 ps to 0.4 ps, and the CSS lifetime is prolonged from 311.4 ps to 40 μs, indicating that aggregation concomitantly promotes fast CS and long-lived CSS. Fast CS arises from the hot charge-transfer states dissociation, opening up additional resonant channels to free carriers (FCs); subsequently, charge recombination into intramolecular triplet CSS becomes favorable mediated by spin-uncorrelated FCs. Different from fullerene/indacenodithiophene blends, the unique CS mechanism in dyad aggregates reduces the long-lived CSS dependence on molecular order, resulting in a CSS lifetime 200 times longer than blends. This endows the dyad aggregates to exhibit both photoelectronic switch properties and superior photocatalytic capabilities.

Invariant flow rate measurement system for three-component oil-gas-water flow

The paper presents an invariant flow rate measurement system for individual components for a flow that consists of oil, water, and gas. The proposed flow measurement system is a continuation of the work of the authors, which is based on the application of the multichannelling principle of invariance theory. The paper proposes and discusses the structure of the invariant system for measuring the flow rate of oil-water-gas, analytical expressions are obtained for the implementation of algorithms for measuring the flow rate of individual substances that make up the flow. The uncertainty of the flow rate measurement results was assessed separately for oil, water, and gas. In this work, it is shown that by selecting flow meters of the main and additional channels with an uncertainty of less than 0.5 %, for almost any ratio of components in the additional pipeline, it is possible to measure the flow rate of water or oil with an uncertainty of less than 3 %, and the flow rate of the gas fraction in free form can be measured with an uncertainty value of less than 1 %. The paper discusses the practical aspects of the implementation of an industrial prototype of the system and the characteristics that affect its accuracy and efficiency.

Beyond social influence: Examining the efficacy of non-social recommendations

Do recommendations need to contain social information to change behaviour in allocation and risk tasks? We conducted two online experiments involving 1280 participants to compare the behavioural influence of recommendations based on normatively relevant information with that of recommendations that were transparently random. Although social recommendations generally shifted choices towards the recommended option, consistent with previous studies on norm compliance, their effects were statistically indistinguishable from those of random recommendations. This finding challenges the notion that norm compliance is the sole mechanism through which social recommendations exert their influence. In a follow-up study with 481 participants, we investigated four additional channels. Our results suggest that recommendations do not act as reminders of existing normative knowledge, but we find evidence partially consistent with recommendation following in order to deflect responsibility, because of an anchoring effect, and because of a social norm to follow recommendations.

Ultra-permeable thin-film nanocomposite membrane with an asymmetric structure harvested by a heterogeneous interlayer for brackish water desalination

Constructing interlayers has proven highly efficacious in augmenting the performance of polyamide (PA) NF membranes. However, the fabrication of highly-permeable interlayered RO membranes poses significant challenges. In this work, we propose a hydrophilic-hydrophobic heterogeneous interlayer strategy to fabricate an ultra-permeable thin-film nanocomposite membrane with asymmetric two-layered structures (a-TFN). This membrane comprises a dense PA upper layer doped with ordered ZIF-8 nanocrystals and a porous dendrimer lower layer. The heterogeneous interlayer, characterized by nonuniform wettability, is more supportive of the eruption and diffusion of MPD monomers compared to a hydrophilic interlayer, beneficial to the formation of a highly cross-linked PA layer replete with nanovoids. Additionally, the in-situ encapsulation of ZIF-8 nanocrystals within the dense PA layer provide additional transport channels, while the dendrimer layer serves as a gutter layer, collectively enhancing water transport. The resulting a-TFN membrane exhibits an unprecedented water permeance (8.67 ± 0.13 L·m−2·h−1·bar−1), outperforming state-of-the-art commercial and advanced structural RO membranes, while maintaining competitive NaCl rejection (98.1 ± 0.19 %). Furthermore, it demonstrates exceptional structural durability, resistance to compaction, and antifouling performance. This study provides valuable insights for the design of interlayered RO membranes with enhanced performance.

Controllable synthesis of 3D PdCu/Ti3C2Tx hierarchical nanostructures for chemiresistive room temperature H2 sensors

To enhance the detection performance of hydrogen (H2), we employed a self-sacrificing template method to prepare a three-dimensional (3D) PdCu-modified Ti3C2Tx nanocomposite, denoted as PdCu/Ti3C2Tx. Within 3D PdCu/Ti3C2Tx nanocomposite, PdCu as the active center component, was evenly distributed on Ti3C2Tx nanosheets. The unique architecture increased the exposure of active center sites, while the Ti3C2Tx nanosheets provided additional gas diffusion channels, thereby contributing to improved gas sensing performance. Comparing to PdCu nanoparticles, PdCu/Ti3C2Tx exhibited an enhancing response and a fast response time of 4 s to 0.5 % H2. PdCu/Ti3C2Tx also showed an ultra-low detection limit of 0.1 % H2 and excellent repeatability, selectivity and long-term stability. The outstanding gas sensing performance could be attributed to the 3D structure and the heterostructure between PdCu and Ti3C2Tx. The insights gained from this study provide novel perspectives for designing and synthesizing high-performance gas-sensitive materials.

Novel superjunction Fin-based NiO/β-Ga2O3 HJFET with additional surface drift region channels for record-high performance

—In this paper, a novel superjunction fin-based NiO/β-Ga2O3 heterojunction field-effect transistor (SJ Fin-HJFET) is proposed and studied by simulations. Compared with the conventional Ga2O3 SJ FinFET, Ga2O3 SJ Fin-HJFET can generate surface conduction channels instead of depletion zones near the p-n junction interface in the SJ drift region. The additional surface conduction channel significantly improves the specific on-resistance of the SJ Fin-HJFET (from 1.091 mΩ cm2 to 0.397 mΩ cm2, reduced by 63.6 %) and dramatically improves the Baliga figure of merit (BFOM, form 11.75 GW/cm2 to 32.28 GW/cm2) at the same breakdown voltage (3580 V). The effect of different conduction band offset (ΔEC) on the performance of the SJ Fin-HJFET is also investigated. The simulation results show that the on-resistance advantage of the SJ Fin-HJFET applies to a wide range of ΔEC, exhibiting strong applicability and stability. These results indicate that the SJ Fin-HJFET has record-high performance and promising application prospects.

Masked cross-domain self-supervised deep learning framework for photoacoustic computed tomography reconstruction

Accurate image reconstruction is crucial for photoacoustic (PA) computed tomography (PACT). Recently, deep learning has been used to reconstruct PA images with a supervised scheme, which requires high-quality images as ground truth labels. However, practical implementations encounter inevitable trade-offs between cost and performance due to the expensive nature of employing additional channels for accessing more measurements. Here, we propose a masked cross-domain self-supervised (CDSS) reconstruction strategy to overcome the lack of ground truth labels from limited PA measurements. We implement the self-supervised reconstruction in a model-based form. Simultaneously, we take advantage of self-supervision to enforce the consistency of measurements and images across three partitions of the measured PA data, achieved by randomly masking different channels. Our findings indicate that dynamically masking a substantial proportion of channels, such as 80%, yields meaningful self-supervisors in both the image and signal domains. Consequently, this approach reduces the multiplicity of pseudo solutions and enables efficient image reconstruction using fewer PA measurements, ultimately minimizing reconstruction error. Experimental results on in-vivo PACT dataset of mice demonstrate the potential of our self-supervised framework. Moreover, our method exhibits impressive performance, achieving a structural similarity index (SSIM) of 0.87 in an extreme sparse case utilizing only 13 channels, which outperforms the performance of the supervised scheme with 16 channels (0.77 SSIM). Adding to its advantages, our method can be deployed on different trainable models in an end-to-end manner, further enhancing its versatility and applicability.

Polarization-based target detection approach to enhance small surface object identification ensuring navigation safety

This research introduces a groundbreaking approach to significantly enhance the performance of navigation radars under adverse weather conditions. Traditional ship radars, relying on horizontal polarization, encounter difficulties in effectively suppressing rain interference. In response, this study proposed an innovative method employing circular polarization for detecting navigation targets. This technique capitalizes on the distinct polarization properties exhibited by stable navigation targets and fluctuating interfering objects. Theoretical analysis and model experiments substantiate consistent ellipticity parameter values of scattered waves, independent of rain intensity, for both rain interferers and surface metallic objects. The practical implications of our research are highly promising. They enable detection irrespective of the noise-to-signal ratio by integrating an additional channel of circularly polarized waves and applying straightforward mathematical functions. This advancement marks a significant stride towards overcoming the challenges posed by rainy conditions in maritime navigation radar systems.

Biomimetic and electrostatic self-assembled nanocellulose/MXene films constructed with sequential bridging strategy for flexible supercapacitor

Despite the two-dimensional titanium carbide MXene (Ti3C2Tx) has shown promising applications in energy storage, the inherent self-stacking and weak connectivity among nanosheets present a challenge in manufacturing robust MXene films for emerging flexible supercapacitors. Herein, inspired by the robust “soft-hard” structured exoskeletons of crustaceans, the biomimetic cellulose nanofibers (CNFs)/MXene-Al (CM-Al) film with integrated high mechanical toughness, electroconductivity and electrochemical behavior, sequential bridging with hydrogen and ionic bonds, is crafted via the facile electrostatic self-assembly strategy. The embedded CNFs guide the in-plane orientation of MXene through hydrogen bonding, forming a “soft-hard” microstructure and dramatically enhancing the mechanical toughness of CM-Al. The rigid ionic bonds established between the oxygen-containing groups on CNFs and MXene with Al3+ further elevate the mechanical strength (163.88 MPa) and act as additional electron transfer channels to impart the reinforced electroconductivity (82.63 S cm−1). Benefiting from the more active site exposure induced by the expanded MXene layer spacing after CNFs embedding and the weakened intrinsic resistance caused by the constructed ionic bonding, the assembled flexible quasi-solid-state symmetric supercapacitor with CM-Al as electrode delivers a high area capacitance (679 mF cm−2), energy density (16.2 μWh cm−2), cycling capability (85.3 % capacitance retention after 10,000 cycles) and intrinsic tolerance to various non-stretching deformations. Moreover, the selective principles for metal ions are summarized that involved a comprehensive consideration of ionic radius, charge density and basic chemical properties. This work demonstrates an accessible and feasible construction strategy for flexible composite films and provides an alternative pathway for wearable energy storage devices.

Designing a three-dimensional CoFe2O4 cross-frame wrapped with carbon nanotubes for monitoring the environmental pollutant nitrobenzene

In this study, we employ a catalytic system derived from a zeolitic imidazolate framework (ZIF), comprising carbon nanotube-wrapped CoFe2O4 with a modified 3D cross morphology. The seamless transition between ionic valence states in CoFe2O4 contributes to enhanced material conductivity, illustrating a significant synergistic coupling effect. The 3D matrix has the capacity to generate a greater number of active sites and exhibit a high surface area. The generation of nanotubes provides additional channels for electron transport, thereby improving the charge transfer efficiency and enhancing the electrochemical sensing capability of the system. The synthesized material demonstrates outstanding electrochemical sensing capabilities for nitrobenzene, exhibiting impressive sensitivity with a remarkably low limit of detection at 0.013 μM and a broad linear response range (0.06–414.9 μM), heightened sensitivity, excellent repeatability, and superior selectivity. Furthermore, the quantification of trace nitrobenzene in water samples demonstrates a recovery rate within the range of 96.0 %–102.8 %. Consequently, this material presents itself as a promising catalyst for electrochemical analysis and introduces a novel approach for detecting low concentrations of nitrobenzene.

Ultraviolet-cured heat-resistant and stretchable gel polymer electrolytes for flexible and safe semi-solid lithium-ion batteries

Lithium-ion (Li-ion) batteries assembled with gel polymer electrolytes (GPEs) are predicted to increase battery energy density while maintaining battery safety. In this work, poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) is successfully used as a polymer matrix to prepare a new kind of GPE (PHHNT) by ultraviolet (UV) curing technology. The polymer network structure formed by photopolymerization technology significantly enhances the tensile properties of the electrolyte. Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) improves the concentration and transport efficiency of lithium ions in the electrolyte as well as the ionic conductivity (1.22 × 10−3 S cm−1) of the GPEs. In addition, the unique tubular structure of the halloysite nanotube (HNT) and the opposite charges carried by the inner and outer surfaces provide additional channels for the lithium salt and facilitate its dissociation. This enhances the expedited movement of Li+ inside the electrolyte, while simultaneously improving the electrochemical and thermal durability of the electrolyte. The assembled LiFePO4 (LFP)/PHHNT/Li battery has an initial discharge-specific capacity of 140.5 mAhg−1 at a current density of 0.5C, showing a high capacity retention rate of 89 % after 120 cycles. The design of this composite material significantly improves the overall performance of the electrolyte and is more suitable for flexible and safe solid-state Li-ion batteries.