Transport Capability Research Articles

Ultrathin H-MXM as An "Ion Freeway" for High-Performance Osmotic Energy Conversion.

Nanofluidic membranes are currently being explored as potential candidates for osmotic energy harvesting. However, the development of high-performance nanofluidic membranes remains a challenge. In this study, the ultrathin MXene membrane (H-MXM) is prepared by ultrathin slicing and realize the ion horizontal transportation. The H-MXM membrane, with a thickness of only 3 µm and straight subnanometer channels, exhibits ultrafast ion transport capabilities resembling an "ion freeway". By mixing artificial seawater and river water, a power output of 93.6 Wm-2 is obtained. Just as cell membranes have an ultrathin thickness that allows for excellent penetration, this straight nanofluidic membrane also possesses an ultrathin structure. This unique feature helps to shorten the ion transport path, leading to an increased ion transport rate and improveS performance in osmotic energy conversion.

Nonstoichiometric In–S group yielding efficient carrier transfer pathway in In2S3 photoanode for solar water oxidation

AbstractThe construction of high‐efficiency photoanodes is essential for developing outstanding photoelectrochemical (PEC) water splitting cells. Furthermore, insufficient carrier transport capabilities and sluggish surface water oxidation kinetics limit its application. Using a solvothermal annealing strategy, we prepared a nonstoichiometric In–S (NS) group on the surface of an In2S3 photoanode in situ and unexpectedly formed a type II transfer path of carrier, thereby reducing the interfacial recombination and promoting the bulk separation. First‐principles calculations and comprehensive characterizations demonstrated NS group as an excellent oxygen evolution cocatalyst (OEC) that effectively facilitated carrier transport, lowered the surface overpotential, increased the surface active site, and accelerated the surface oxygen evolution reaction kinetics by precisely altering the rate‐determining steps of * to *OH and *O to *OOH. These synergistic effects remarkably enhanced the PEC performance, with a high photocurrent density of 5.02 mA cm−2 at 1.23 V versus reversible hydrogen electrode and a negative shift in the onset potential by 310 mV. This work provides a new strategy for the in situ preparation of high‐efficiency OECs and provides ideas for constructing excellent carrier transfer and transport channels.

Modeling and enhancement of double perovskite solar cell using WO3 as electron transporting material and SrCu2O2 as hole transporting material

There is a growing necessity to develop renewable energy with cost-effective materials. In this work, a double perovskite-based solar cell design has been proposed. The proposed design is numerically simulated, and investigation of solar cell parameters has been carried out using SCAPS-1D simulation software. (FA)2BiCuI6 is an organic–inorganic double perovskite material employed as an absorber layer. SrCu2O2 is used as hole transporting material and WO3 is used as electron transporting material in proposed device model FTO/WO3/(FA)2BiCuI6/SrCu2O2/W. SrCu2O2 absorbs lower light due to its wide bandgap and provides better hole transport capability which reduces the recombination. WO3 has tunable bandgap and absorb light in visible spectrum and offer good conductivity and thus this combination improve the power conversion efficiency. The analysis and optimization of the various parameters of absorber layer such as thickness, shallow acceptor density, and operating temperature are done. At 500 nm absorber thickness for shallow acceptor density of 1.0 × 1018 cm−3 and 300 K operating temperature, the optimized results have been observed. The photo-voltaic parameters: open circuit voltage 1.04 V, short circuit current density 25.97 mA/cm2, fill factor 88.23 % and power conversion efficiency of the device 23.64 % are observed. The proposed configuration is a promising candidate for efficient, low-cost double perovskites-based solar cells.

Gasification of solid biomass or fast pyrolysis bio‐oil: Comparative energy and exergy analyses using AspenPlus®

AbstractThe conversion of biomass residues into syngas through gasification is attractive for energy and process industry applications. However, transportation, storage, and operational challenges limit the conventional direct solid biomass gasification process. To address these issues, the intermediate conversion of biomass to bio‐oil has emerged as a promising alternative. Bio‐oil offers improved transport and storage capabilities due to its higher mass and energy density, enabling the decoupling of solid biomass supply and syngas demand. This study compares two routes for syngas production: direct gasification of solid biomass and indirect gasification using bio‐oil from biomass pyrolysis as an intermediate with biochar and pyrolysis gas supplying thermal energy to the pyrolysis stage. Biochar combustion provides about 1.4 MJ kg−1 of dry biomass to maintain the pyrolysis temperature at 480°C. Using AspenPlus® simulations, the composition and Low Heating Value of the syngas produced by both routes are analyzed. Energy and exergy analysis at different equivalence ratios and temperatures revealed that direct gasification has higher efficiencies than indirect gasification. At 1000°C and an equivalence ratio of 0.4, the highest energy and exergy efficiencies occurred in direct gasification processes. The energy efficiency of direct and indirect gasification amounted to 62% and 53%, respectively. At the same time, the corresponding exergy efficiencies were 65% and 61%. The syngas of direct and indirect gasification processes is a starting point to produce energy, synthetic fuels, and chemicals; this study provides insights for designing and optimizing biomass gasification processes.

Study on the thermal performance of pulmonary vascular-inspired grooved vapor chamber

The increasing miniaturization and integration of electronic devices have led to higher requirements for heat dissipation. To further enhance the heat transfer performance of the vapor chamber, this study proposes a novel vapor chamber with a pulmonary vascular-inspired grooved wick. Through a combined approach of numerical simulation and experimental research, the thermal performance of the proposed vapor chamber is tested and compared with the radially grooved vapor chamber(RGVC) of the same size and copper plate. The results demonstrate that within the heating power range of 0 W-30 W, the pulmonary vascular-inspired grooved vapor chamber(PGVC) exhibits superior temperature uniformity and heat transport capability. Under a heat load of 25 W, its thermal resistance is reduced by 52.73 % and 21.21 % compared to the copper plate and RGVC, respectively, while the heat transfer coefficient is increased by 107.61 % and 25.86 %, respectively. Furthermore, the PGVC achieves optimum performance at a liquid filling ratio of 75 %, with a remarkably low thermal resistance of 0.23℃/W at a heat load of 30 W.

Grain boundary passivation by alkylammonium salt for highly stable perovskite solar cells

Perovskite solar cells (PSCs) are a strong candidate for next-generation photovoltaics, but their long-term stability poses challenges for use as a future renewable energy source. In particular, ambient moisture causes detrimental effects on not only the stability but also performance of PSCs. Herein, alkylammonium salts with perfluorinated long alkyl chains are introduced to passivate the grain boundaries and form hydrophobic surfaces. The perfluorinated alkyl chain moiety introduced into the perovskite layer reduces defect density and suppresses nonradiative recombination, thereby enhancing carrier transport capability and achieving a power conversion efficiency (PCE) of 20.31 %. Given the hydrophobic effects of fluorinated compounds on PSCs, about 90 % of the initial PCE can be retained after 1,000 h of continuous operation under a relative humidity of ∼ 40 % without encapsulation. The proposed additive strategy thus enables long-term operational stability of PSCs under humid conditions.

Numerical simulation of liquid water transport in ordered microstructures gas diffusion layer of proton exchange membrane fuel cell

The performance of the gas diffusion layer (GDL) plays a pivotal role in ensuring the efficient and stable operation of proton exchange membrane fuel cells (PEMFCs). Microstructure of the GDL significantly influences its internal water transport capabilities. In this article, the lattice array method is employed to construct ordered microstructures within GDLs, followed by the utilization of phase field method to numerically simulate water transport among these structures. The effects of lattice edge length, lattice height, and lattice shape on water transport throughout the GDL are investigated. The results reveal that excessively large or small lattice edge lengths detrimentally affect effective water transport within the GDL. Additionally, a smaller lattice height can accelerate the breakthrough of liquid water through the GDL. Notably, when the lattice height is smaller than the lattice edge length, it enhances the mass transfer. Moreover, the triangular lattice impedes the water flow, while the rectangular structure diminishes the transmission efficiency of liquid water. In contrast, hexagonal and octagonal structures exhibit the ability to alleviate the transport resistance of liquid water, with the octagonal lattice demonstrating superior mass transfer effectiveness. These findings underscore the paramount importance of meticulous structural design in further augmenting the mass transfer performance of ordered GDLs. The research provides meaningful guidance for the design of GDL structures.

Controlling a peristaltic robot inspired by inchworms

This study presents an innovative approach in soft robotics, focusing on an inchworm-inspired robot designed for enhanced transport capabilities. We explore the impact of various parameters on the robot’s performance, including the number of activated sections, object size and material, supplied air pressure, and command execution rate. Through a series of controlled experiments, we demonstrate that the robot can achieve a maximum transportation speed of 8.54 mm/s and handle loads exceeding 100 g, significantly outperforming existing models in both speed and load capacity. Our findings provide valuable insights into the optimization of soft robotic design for improved efficiency and adaptability in transport tasks. This research not only contributes to the advancement of soft robotics but also opens new avenues for practical applications in areas requiring precise and efficient object manipulation. The study underscores the potential of biomimetic designs in robotics and sets a new benchmark for future developments in the field.

Elucidating Morphology‐Mobility Relationships of Organic Thin Films Through Transfer Learning‐Assisted Multiscale Simulation

AbstractUnderstanding the relationship between morphology and charge transport capability in organic thin films is vital for advancements in organic electronics. However, accurately predicting charge mobility in these films is challenging due to the extensive evaluations of transfer integral required. To address this challenge, transfer learning techniques are employed to develop machine learning models capable of efficiently and accurately calculating transfer integrals in organic thin films with grain boundaries and polymorphs. Through machine learning‐assisted multiscale simulations of charge transport, the impact of solution shearing conditions is investigated on the morphology and mobility of organic thin films. The findings reveal that shearing‐induced molecular orientation and pre‐aggregation have a significant influence on film morphology, and a moderate shearing speed combined with a suitable solvent promotes the formation of extended transport networks, leading to higher mobility. The utilization of transfer learning‐accelerated simulation techniques opens up new possibilities for exploring the relationship between solution‐processing conditions, morphology, and charge transport properties of organic thin films. This research provides valuable insights that can be applied to optimize solution‐processing techniques in organic electronics.

Branchial CO2 and ammonia excretion in crustaceans: Involvement of an apical Rhesus-like glycoprotein.

To determine whether the crustacean Rh1 protein functions as a dual CO2 /ammonia transporter and investigate its role in branchial ammonia excretion and acid-base regulation. Sequence analysis of decapod Rh1 proteins was used to determine the conservation of amino acid residues putatively involved in ammonia transport and CO2 binding in human and bacterial Rh proteins. Using the Carcinus maenas Rh1 protein (CmRh1) as a representative of decapod Rh1 proteins, we test the ammonia and CO2 transport capabilities of CmRh1 through heterologous expression in yeast and Xenopus oocytes coupled with site-directed mutagenesis. Quantitative PCR was used to assess the distribution of CmRh1 mRNA in various tissues. Western blotting was used to assess CmRh1 protein expression changes in response to high environmental ammonia and CO2 . Further, immunohistochemistry was used to assess sub-cellular localization of CmRh1 and a membrane-bound carbonic anhydrase (CmCAg). Sequence analysis of decapod Rh proteins revealed high conservation of several amino acid residues putatively involved in conducting ammonia transport and CO2 binding. Expression of CmRh1 in Xenopus oocytes enhanced both ammonia and CO2 transport which was nullified in CmRh1 D180N mutant oocytes. Transport of the ammonia analog methylamine by CmRh1 is dependent on both ionized and un-ionized ammonia/methylamine species. CmRh1 was co-localized with CmCAg to the apical membrane of the crustacean gill and only experienced decreased protein expression in the anterior gills when exposed to high environmental ammonia. CmRh1 is the first identified apical transporter-mediated route for ammonia and CO2 excretion in the crustacean gill. Our findings shed further light on the potential universality of dual ammonia and CO2 transport capacity of Rhesus glycoproteins in both vertebrates and invertebrates.

To the history of pandemics: statistics and forecast.

The article is devoted to the study of human experience related to fight against a viral disease known as influenza infection. The outbreaks of the disease occurred over several millennia and described in the surviving documentary sources are considered. The main attention is paid to investigations of native epidemiologists on this problem. In particular, an analysis of works published more than 80 years ago is shown. It is emphasized that some elements of the influenza epidemic described in this publication are in many respects similar to the features of the modern coronavirus pandemic. History of studies devoted to mechanism of infection transmission is described. Significant attention is paid to the developments of scientists associated with the problem of identifying the causative agent of the disease. The contribution of native scientists in revealing the features of the pathogenesis of infection diseases is highlighted. It is noted that important factors in the spread of infection nowadays are globalization and migration processes. It is emphasized that the speed of infectious diseases spread is considerably caused by the capabilities of modern transport too. The history of studies related to the prevention of influenza by immunization and vaccination is reviewed. A comparative analysis of the application of these prophylactic arrangements in a historical retrospective is given. The possibility of preventing the spread of a viral infection by taking appropriate measures was emphasized. The important role of the mass media is indicated, which consists in timely and truthful information of the population. The position of leading modern scientists on this issue, in particular, M. Honigsbaum, K. G. Vasiliev, S. V. Komisarenko etc. is cited. It is summarized, that the works of native epidemiologists L. V. Hromashevskyi, N. F. Gamaleya, D. S. Samoilovych and others has not lost its relevance and can be the basis for the searching effective methods to combat influenza infection in future.

Element Diffusion Induced Carrier Transport Enhancement in High-Performance CZTSSe Self-Powered Photodetector.

Cu2ZnSn(S,Se)4 (CZTSSe) has attracted great interest in thin-film solar cells due to its excellent photoelectric performance in past decades, and recently is gradually expanding to the field of photodetectors. Here, the CZTSSe self-powered photodetector is prepared by using traditional photovoltaic device structure. Under zero bias, it exhibits the excellent performance with a maximum responsivity of 0.77 A W-1, a high detectivity of 8.78 × 1012 Jones, and a wide linear dynamic range of 103dB. Very fast response speed with the rise/decay times of 0.576/1.792 µs, and ultra-high switching ratio of 3.54 × 105 are obtained. Comprehensive electrical and microstructure characterizations confirm that element diffusion among ITO, CdS, and CZTSSe layers not only optimizes band alignment of CdS/CZTSSe, but also suppresses the formation of interface defects. Such a suppression of interface defects and spike-like band alignment significantly inhibit carrier nonradiative recombination at interface and promote carrier transport capability. The low trap density in CZTSSe and low back contact barrier of CZTSSe/Mo could be responsible for the very fast response time of photodetector. This work definitely provides guidance for designing a high performance self-powered photodetector with high photoresponse, high switching ratio, fast response speed, and broad linear dynamic range.

Li-Zn alloy patch for defect-free polymer interface film enables excellent protection effect towards stable Li metal anode

Constructing a smart polymer film with favorable lithium (Li) transport capability and mechanical flexibility for suppressing Li dendrite growth is an effective strategy. Unfortunately, the porosity and the swelling of the polymer membrane cannot completely prevent liquid electrolyte from sweeping through the artificial protection film, severely deteriorating the cyclic performance. Herein, we propose a defect-free hybrid film that consists of Li+ conductive lithium polyacrylate (LiPAA) polymer interface layer and Li-Zn alloy patch to tackle the critical problems of traditional polymer composite passivation film. The pinhole leaks of the polymer matrix are self-filled by Li-Zn alloy patches, enhancing the integrity of LiPAA film. Consequently, a defect-free hybrid film is nailed flat against the Li metal anode, exhibiting extraordinary stability in the liquid electrolyte and enabling perfect protection effect. This facile strategy produces a promising anode for next generation Li batteries.

A dual-height wick to improve capillary performance of vapor chambers

The wick performance is a crucial metric for ensuring the reliable and efficient operation of vapor chambers (VCs) away from dry-out. To enhance the performance of VC, a pitcher plant inspired enhanced wick characteristic dual-height microgrooves (DHMW) was fabricated on 6063 aluminum alloy by one-step picosecond laser texturing without chemical modification. This study describes the two-step capillary behavior of DHMW by high-speed camera and infrared camera. The effects of minor rib number, groove height ratio, length scale, and test liquids (water, acetone, ethanol) on the capillary performance were investigated. When using water as the working fluid, the DHMW achieved a K/Reff of 1.182 µm, which was about 71.3 % larger than that of normal microgroove wicks due to the liquid propagation effect and the flow resistance reduction effect. Furthermore, the maximum K/Reff could reach 1.819 µm of the sample with a minor rib depth of about 70 μm. However, the wetting results showed that the droplets of acetone and ethanol tend to spread laterally after contact with the surface, which is unfavorable for the formation of hierarchical transport in the DHMW. This study demonstrates that laser texturing is an effective and controllable method for the complex shaping of grooved aluminum wicks, with the potential to improve the heat transport capability of VCs.

Potassium doping for grain boundary passivation and defect suppression enables highly-efficient kesterite solar cells

The complicated and diverse deep defects, voids, and grain boundary in the CZTSSe absorber are the main reasons for carrier recombination and efficiency degradation. The further improvement of the open-circuit voltage and fill factor so as to increase the efficiency of CZTSSe device is urgent. In this work, we obtained K-doped CZTSSe absorber by a simple solution method. The medium-sized K atoms, which combine the advantages of light and heavy alkali metals, are able to enter the grain interior as well as segregate at grain boundary. The K-Se liquid phase can improve the absorber crystallinity. We find that the accumulation of the wide bandgap compound K2Sn2S5 at grain boundary can increase the contact potential difference of grain boundary, form more effective hole barriers, and enhance the charge separation ability. At the same time, K doping passivates the interface as well as bulk defects and suppresses the non-radiative recombination. The improved crystallinity, enhanced charge transport capability and reduced defect density due to K doping result in a significant enhancement of the carrier lifetime, leading to 13.04 % device efficiency. This study provides a new idea for simultaneous realization of grain boundary passivation and defect suppression in inorganic kesterite solar cells.

N-doped lithium titanium oxide for high power Li-ion rechargeable batteries with excellent cyclability

Lithium titanate, Li4Ti5O12 (LTO) is being explored as an anode in Li-ion batteries owing to its minimal structural change during lithiation/delithiation and excellent capacity retention at higher current rates. However, the lack of stable cyclability at higher applied currents owing to low electronic conductivity, restricts its widespread applications. Solid state anionic doping represents a convenient strategy to improve the intrinsic electronic conductivity of the LTO material. Hence, a facile and scalable solid state‐inspired protocol has primarily been devised aimingthe large-scale production of nitrogen-doped LTO. The structural analysis demonstrates the diffusion of nitrogen into the lattice without damaging the intrinsic microstructure of LTO. The 2% nitrogen-doped LTO as a working electrode in Li-ion half-cell, displays enhancement in Li-storage capacity by 30%. Moreover, it exhibits excellent rate performance (131 mAhg−1 @ 5C) and ultra-long cycling stability upto 1000 cycles retaining 82 % capacity. Further, full cell study of N@LTO with LiCoO2 exhibits specific capacities of more than 155 mAh/g at a 0.05C rate. Overall, the enhancement in performance attributes to N doping which is likely to improve not only the electrical conductivity but also the ion transport capabilities. Hence the N@LTO will have potential in high power Li-ion batteries.

Cu2ZnSnS4/N-MWCNTs hybrid systems as counter electrode substitutes for platinum in dye-sensitized solar cells

Copper zinc tin sulfide, Cu2ZnSnS4 (CZTS) is being considered a viable option for a counter electrode due to its abundance, cost-effectiveness, catalytic activity, and other advantageous properties. However, CZTS has low electron transport capabilities, a shortcoming that can be addressed by combining it with high electron mobility carbon nanomaterials. Nitrogen-doped multi-walled carbon nanotubes (N-MWCNTs) exhibit higher electron conductivities than their pristine counterparts. This improvement is attributed to the disruption of the sp2-hybridized carbon arrangement, as some of the carbon atoms are replaced by nitrogen atoms. In this study, a counter electrode composed of a 70% CZTS and 30% N-MWCNTs mixture produced a higher electrochemical current density compared to the individual materials. This suggests that it is more electrocatalytic than CZTS and N-MWCNTs alone, ultimately leading to the highest power conversion efficiency of 6.52%.Graphical abstract

Back interface engineering by 2D layered N–Ti3C2 in low-cost carbon based all-inorganic hole transport layer free perovskite solar cells

The mismatched energy level alignments, back interface defects in the perovskite/carbon back interface, as well as low conductivity of carbon counter electrode are the primary factors for the low photovoltaic behavior of all-inorganic hole transport layer (HTL)-free perovskite solar cells (C–PSCs) using carbon counter electrode-based. Herein, 2D layered Ti3C2 and N–Ti3C2 are proposed to form Ti3C2@carbon and N–Ti3C2@carbon counter electrodes for modifying the perovskite/carbon back interface. First, the appropriate work function of Ti3C2 can optimize the energy level alignments. Second, nitrogen doping can enhance the conductivity of Ti3C2 which can lower the total resistance of the device. Third, the specific 2D layered structure Ti3C2 and N–Ti3C2 can reduce back interface defects. Therefore, the perovskite/carbon back interface shows improved charge extraction and transport capabilities disclosed by photoluminescence measurements. Consequently, the power conversion efficiencies (PCE) of the C–PSCs are enhanced to 7.56 % from 5.94 % by using Ti3C2@carbon counter electrode, and further to 8.91 % by using N–Ti3C2 @carbon counter electrode, indicating remarkable PCE improvements of 27.3 % and 50.0 %. Moreover, the Ti3C2@carbon and N–Ti3C2@carbon-based C–PSCs show remarkable stabilities under ambient conditions for 30 days. This work is expected to provide a feasible path to optimize the back interface of the all-inorganic C–PSCs.

Trapping waste metal ions in a hydrogel/coal powder composite for boosting sewage purification via solar-driven interfacial water evaporation with long-term durability

The improper disposal of effluents contaminated with waste metal ions poses significant threats to clean water resources. Recently, solar-driven interfacial water evaporation has gained increasing interests for sustainable water purification, nevertheless, the presence of various hydrated metal ions from industrial effluents makes it challenging for conventional distillers to achieve efficient purification performances. Herein, a waste metal ion trapping strategy based on a novel solar vapor generator (SVG) toward highly efficient solar-driven sewage purification with prolonged durability is reported. This SVG is constructed based on a polyion complex (PIC) hydrogel/coal powder composite (PCC), where the PIC skeleton provides metal ion entrapment capabilities, and the low-cost coal powders act as solar absorbents. PCC enables improved solar-driven sewage purification from two aspects: first, the entrapped multivalent ions help to activate the water molecules inside PCC and lower water evaporation enthalpy, leading to enlarged evaporation rate; second, the strong interactions between the multivalent metal ions and polyelectrolyte chains aid in stabilizing their porous structure and maintaining continuous water transport capabilities. The resultant PCC-based SVG demonstrated high evaporation rate up to 3.6 kg · m−2· h−1 in simulated industrial sewage under one sun illumination, as well as stable and efficient clean water generation in actual coal washery wastewater even for three weeks. We envision that the rational design of SVG with ions trapping capabilities and cost-effective solar absorbers should broaden the practical applications of SVG for harsh wastewater treatment.

Development and verification of tritium transport code based on RELAP5/MOD3.3 with generic model towards COOL blanket

Tritium evaluation is a critical issue in fusion reactors. For the tritium self-sufficiency and safety concern, it is crucial to develop tritium analysis techniques to study its behavior in various conditions including steady states and dynamic states. The supercritical CO2 cOoled Lithium-Lead (COOL) blanket is an advanced blanket concept for the Chinese Fusion Engineering Testing Reactor (CFETR) and one of its major functions is to realize tritium self-sufficiency. Therefore, it is necessary to conduct comprehensive analyses for design and optimization from the perspective of tritium transport. In this work, the tritium transport module is integrated inside RELAP5/MOD3.3. Then the modified RELAP5 facilitates transient analyses to examine coupled thermal hydraulics and tritium transport responses. The code includes 1-D tritium permeation, tritium transport in fluid and tritium extraction, which are associated with thermodynamic parameters to cover the multi-physics processes of the COOL blanket. The modified RELAP5 is verified by the code-to-code benchmark. The results demonstrate the successful integration of the tritium transport capabilities in RELAP5. Furthermore, the code is applied to the heat exchanger and simplified PbLi loop to obtain tritium concentration to highlight its capability in both generic modeling and dynamic analysis.