Commercial Exchange Research Articles

Influence of ionomer concentration and membrane thickness on membrane electrode assembly in alkaline fuel cell performance

AbstractThe alkaline fuel cell is subject to extensive research owing to its fast kinetic response relative to acidic media. However, the efficiency of the catalytic layer at the electrodes depends on the amount and distribution of ionomers present there. It is crucial to have the right ionomer concentration to have the best cell performance. Additionally, the membrane thickness is a significant parameter that affects the system performance in alkaline fuel cells. This research studies the best alkaline fuel cell performance using the membrane electrode assembly preparation parameters. The prepared membrane electrode assembly consists of catalyst layers containing Fumion, a commercial anion exchange ionomer, as a binding agent, sandwiched a Fumasep, a well‐known commercial anion exchange membrane. This work elucidates the single‐cell alkaline fuel cell performance by quantifying the influence of Fumion concentrations (~20–60 wt.%) within the catalytic layer and Fumasep thicknesses (30, 75 and 130 μm). The best concentration of Fumion was found to be 50 wt.%, culminating in the maximum peak power density of 67 mW cm−2 achieved by the FAA‐3‐PK‐75. Meanwhile, FAA‐3‐PK‐130 exhibited the highest open‐circuit potential with lowest power density at 53 mW cm−2. These findings may serve as a valuable guide for membrane electrode assembly preparation in alkaline fuel cells.

Impact of digital burnout on the use of digital consumer platforms

As digital transition processes occur at a high speed, new models and business opportunities are emerging. One such phenomenon is the explosion of digital consumer platforms that are changing consumption patterns, as well as the boundaries of commercial exchange. The onset of the COVID-19 pandemic resulted in exponential growth of this consumption model, while the motivation for the use of digital platforms intensified. The intensive use of digital devices also threatens the mental health of digital users, enhancing states of stress, anxiety, and digital burnout. Therefore, this study analyses the effects of motivators and digital burnout on customers' use of digital platforms in a post-pandemic context. The sample comprised 202 participants who voluntarily completed a web-based survey. The digital burnout level of the study participants was lower than the theoretical midpoint of the scale and was significantly influenced by their Internet Addiction. Contrary to expectations, digital burnout has a significant positive effect on the use of digital consumer platforms, which is partially mediated by utilitarian motivation. The results highlight the need to consider predictors that potentially lead to digital burnout in consumers and the subsequent identification of the necessary factors to ensure the prevention and management of digital burnout.

Trade between the United States and Indochinese Union in the First Half of the 20th Century

This article aims to analyze the commercial activities between the Indochinese Union (Indochina) and the United States in the first half of the XX century. The study focuses on three fundamental issues: The US efforts to seek markets in the Indochina region; commercial exchanges between the French-controlled Indochina and the US in the first half of the XX century; and the commercial benefits that the parties obtained. The results show that the commercial exchange between the Indochina and the US was under the strict management and control of the French colonial government. The policies that France conducted in Indochina during this period caused many disadvantages for the Indochina - US commercial relationship. The Indochinese Union did not have much freedom in choosing trade partners and was highly dependent on France's policies in the colonies. Apart from the subjection to France’s manipulation, commercial exchanges between the Indochina and the US had different rules compared to other European and American countries. Starting from merely commercial activities, the US intervened more deeply in the region by launching a military invasion of Indochina. This study contributes to clarifying the commercial policies of France towards the Indochina during the colonial period, the commercial activities of the US in the Far East region, as well as the history of Vietnam in the first half of the XX century.

Phytosanitary Risk Analysis for Anoplophora chinensis (Forster, 1771) on fruit crops, broadleaved ornamental and forest tree species for Bulgaria

Bulgaria is a traditional agricultural country, where various types of fruit crops, such as apple (Malus), pear (Pyrus), peach, apricot and plum (Prunus), are hosts to Anoplophora chinensis (citrus longhorned beetle). In addition, Anoplophora chinensis is a serious pest of ornamental and forest tree species, such as poplar (Populus), willow (Salix), maple (Acer), alder (Alnus), birch (Betula), chestnut (Castanea), beech (Fagus), oak (Quercus), rose (Rosa), etc. Anoplophora chinensis (citrus longhorned beetle) is a widespread pest in Southeast Asia with climate types ranging from tropical to temperate. It has been introduced to the United States, but it has been successfully eradicated. In Europe, outbreaks of Anoplophora chinensis have been reported from Italy, Croatia, Denmark, France, Germany, the Netherlands, Switzerland, Turkey and the United Kingdom. The pest has been successfully eradicated in Denmark, Germany, Switzerland, the Netherlands and the United Kingdom. At this moment, there is no evidence that Anoplophora chinensis is present in the area for which the phytosanitary risk analysis is being carried out. The main routes for the entry of Anoplophora chinensis into the EU and Bulgaria are through the commercial exchange and movement of planting material (plant material including bonsai plants) and wood products (including logs, timber, wooden packaging material from solid wood without bark and pallets) from host plants originating in countries with established infestation. The probability of Anoplophora chinenis entering Bulgaria naturally is relatively low, despite the fact that outbreaks of the pest have been found in the Black Sea region of Turkey, since the maximum distance of natural spread of the pest in one year is about 194 m. The presence of host plants, as well as the climatic conditions in Bulgaria, are not a limiting factor, which is why the pest has great potential to enter new areas and/or to adapt to new climatic and/or ecological conditions. In case of entry, establishment and spread of Anoplophora chinensis in Bulgaria, it can have a negative impact, both on fruit production and timber harvesting, as well as on ecology, biodiversity in broadleaved forests and urban landscapes, and last but not least, on the development of the resort industry and tourism. The effect on exports of agricultural produce and timber would also be negative. A possible entry, establishment and spread of Anoplophora chinensis in our country would also affect the financial situation of farmers.

Influence of Donnan and dielectric exclusion on ion sorption in sulfonated polysulfones

The Donnan – Manning model accurately describes the thermodynamic properties (e.g., ion sorption) of many charged polymers equilibrated with aqueous electrolytes, such as the commercial ion exchange membranes CR61 and Nafion. It less accurately describes the ion sorption properties of sulfonated polysulfone, which is a promising desalination membrane polymer. One possible explanation is that other ionic interactions that are not included in the Donnan – Manning model, e.g., dielectric exclusion (or ion solvation effects) that can be described via the Born model, may have a significant influence on ion sorption in sulfonated polysulfones. We developed a model to account for the influence of both Donnan – Manning and dielectric exclusion factors on ion sorption properties and applied it to sulfonated polysulfones and Nafion. This Donnan – Manning – Born model described the ion sorption properties of sulfonated polysulfones more accurately than the Donnan – Manning model alone. The Donnan – Manning – Born model also predicted ion sorption properties in Nafion with improved accuracy relative to Donnan – Manning predictions, but the improvement was less significant than in the sulfonated polysulfone case. These results provide an approach for quantifying the influence of dielectric exclusion on ion sorption in charged polymers and could be particularly important for materials where dielectric exclusion is relevant.

Accounts Receivable Reform and Financing Constraints: Evidence from China’s A-Share Market

ABSTRACT The commercial bill, as a regulated commercial credit mode, offers better creditor protection, more financing channels, and stronger bargaining power in financing. This paper creatively constructs bills receivable index in the micro level of enterprises and examines the potential impact of billing of accounts receivable on the financing constraints faced by enterprises. This paper also explores the mechanism that causes the impact and check whether the establishment of the Shanghai Commercial Paper Exchange Corporation (SHCPE) has had positive effects. The results show that billing can alleviate the financing constraints of enterprises due to its benefits offered by the commercial bill. Furthermore, the establishment of the Shanghai Commercial Paper Exchange Corporation (SHCPE) can lead to the development of a standardized and transparent bill market, further alleviating the financing constraints. The study also reveals that billing of accounts receivable affects financing constraints mainly by enhancing the quality of debt-like assets and reducing information asymmetry between enterprises and the outside world. For enterprises with longer maturity structure, the effect of billing on the alleviation of financing constraints is more significant.

Closing is more than a list of tactics: how to build rapport while facilitating a commercial exchange

Closing is an essential part of selling. However, academic research related to closing has been quite limited and detailed observational research has not yet been conducted. This research analyzes the closing process in a series of 111 buyer-seller sales interactions using a combination of observational research and a follow-up survey about the customers’ experience. The results of a qualitative analysis suggest that the closing process consists of three stages: (1) the preamble, the lead up or approach to the ask, (2) the closing moment, when the ask is made, and (3) post-sale assurance, the moments directly following the close in which the salesperson debriefs the sales encounter. The closing process impacts customers’ assessment of salesperson responsiveness and empathy, which ultimately leads to relationship commitment. The findings indicate that sufficient post-sale assurance improves both perceived responsiveness and empathy. Meanwhile, the efficacy of the preamble and closing moment techniques depends on customer amicability. For amicable customers, a preamble tactic with a direct close improves perceived responsiveness, while for less amicable customers, indirect closing tactics improve responsiveness. In sum, this research provides a theoretical framework for the closing process and explains the underlying mechanisms by which the closing process impacts sales outcomes.

Hydrogen Production with Seawater-Resilient Bipolar-Membrane Electrolyzers

Commercial proton exchange membrane water electrolyzers (PEMWEs) are highly efficient when operating in ultra-pure de-ionized water. However, introduction of additional ions leads to a reduction in device durability and efficiency. Chloride (Cl-) ions, typically found in high concentrations in seawater, lead to device performance issues driven in part by the chlorine evolution reaction at the anode. At the acidic anode-cation exchange layer interface, corrosive chlorine species (OCl-, HOCl, Cl-) are readily generated due to the facile kinetics of the 2-electron oxidation reaction relative to the desired 4-electron water oxidation reaction. Bipolar membrane water electrolyzers (BPMWEs), however, contain a locally basic anode-anion exchange layer interface, leading to improved thermodynamic favorability for O2 production rather than corrosive chlorine species production. Furthermore, the bipolar membrane can readily block anions and cations from accessing the desired reaction spaces. In this work, we evaluated ion transport, chloride oxidation, and durability of BPMWEs and PEMWEs operating in salt water. BPMWEs exhibit a low Faradaic efficiency of 0.005% for the oxidation of Cl− to corrosive chlorine species at the anode, compared to PEMWEs that can reach a Faradaic efficiency of up to 10% under similar conditions. In addition, BPMWEs demonstrate a device lifetime that is 140 times longer than that of PEMWEs operating in direct seawater electrolysis conditions. Failure modes for each membrane type have been investigated under both ultra-pure and impure water electrolysis conditions and are discussed in this work.

Manufacturing Challenges, Opportunities, and Successes for PEM Electrolysis at Scale

Hydrogen generation via electrolysis has gained much attention internationally as not only a sustainable source of fuel for the transportation, but as a carrier of energy to capture stranded renewable energy due to the carbon-free chemical cycle and response characteristics of the technology. The barrier to entry preventing this technology from being widely adopted is the overall cost associated with both the upfront capital expense as well as the operating cost incurred over the product life. The majority of this cost is driven by 1) low electrical efficiencies due to the high ohmic resistance of thicker membranes required by electrolysis systems to electrochemically compress generated hydrogen for storage and the overpotential associated with the water splitting oxygen evolution reaction (OER) catalysts typically used, 2) high cost of system and cell stack materials, which need to be durable for up to 100,000hrs at potentials approaching 2V in both reducing and oxidizing environments, and 3) the lack of a robust supply chain for high volume manufacturing to further drive down cost through economies of scale.With 95% of hydrogen currently being produced through the reformation of cheap natural gas, significant cost reductions are necessary for electrolysis to become a viable alternative to the incumbent. Commercial proton exchange membrane (PEM)-based electrolysis has reached scales of several hundred kg/day, providing a relevant pathway for industrial scale hydrogen generation with tremendous opportunity for continuing cost reduction by leveraging system and manufacturing scaling laws and advancements in PEM fuel cell materials, manufacturing, and analysis tools. Order of magnitude improvements in some of the highest cost elements are easily achievable and with more research funding being directed towards hydrogen production, the realization of these reductions is occurring at a faster rate. While many improvements in stack design and materials of construction have been identified and implemented, there are still numerous opportunities to explore that would move electrolysis towards a viable, cost-effective alternative to natural gas reformation. This talk will describe some of the areas of success, where research is still needed, and ultimately how each of these improvements translate into cost and the path to reformation parity.

Investigating Proton Exchange Membrane Fuel Cell Durability at Intermediate Temperatures (80 – 120 °C)

For several applications the low operating temperature of 60-80 °C of proton exchange membrane fuel cells (PEMFCs) limit their potential use. Increasing this temperature above 100 °C would simplify the water management and increase the temperature of the produced heat which would allow for more effective cooling systems [1,2]. Further, increasing the operating temperature could potentially allow for other benefits, such as the employment of more affordable catalysts, as the reaction kinetics are enhanced at elevated temperatures. However, operating at higher temperatures can cause increased degradation on the utilized components [3].In this work we investigated how commercial proton exchange membrane electrode assemblies (MEA) aged at various temperatures when operating either using a load cycle (based on the New European Drive Cycle) or constant load. The state of health of the MEA was continuously monitored through cyclic voltammetry, electrochemical impedance spectroscopy, linear sweep voltammetry, CO-stripping measurements and polarization curves. The obtained ageing results were evaluated using a physics-based model using COMSOL to better understand what aging mechanisms were pronounced at higher operating temperatures. Finally, the aged MEA were characterized with SEM and TEM analysis.The results show that all samples underwent an ageing process and that the ageing was accelerated at higher temperatures, as can be seen in the figure . Further, the ageing was more pronounced at a higher load. The measurements showed that the main ageing is occurring at the cathode catalyst layer and a drastic reduction in the electrochemical active surface area of the catalyst was observed. The membrane properties were also altered by the ageing, and a minor reduction in the membrane conductivity was observed. Surprisingly, no significant increase in the hydrogen crossover was observed, suggesting that the elevated temperature does not cause significant pinhole formation.The results shed light on the rate and mechanisms for ageing at various temperatures and can be used to determine the cost and benefits of operating at elevated temperatures.

Reinforced Membranes with PTFE Matrix and Sulfonated Hydrocarbon Electrolyte for PEM Fuel Cells

Proton exchange membrane fuel cells (PEMFCs) have emerged as a promising technology for clean energy conversion with various potential applications. Due to its cost-effectiveness, sulfonated hydrocarbon has been researched as an alternative to Nafion, a commercial proton exchange membrane. However, sulfonated hydrocarbon's mechanical and chemical stability remains a critical challenge that needs to be addressed, as the membrane must withstand harsh operating conditions, such as wet-dry mechanisms in high-temperature operations. To compete with perfluorosulfonic acid (PFSA), sulfonated hydrocarbon should be reinforced with a polytetrafluoroethylene (PTFE) substrate. However, there are significant issues with incompatibility between sulfonated hydrocarbon and PTFE substrate.To improve the impregnation, simple and reproducible chemical treatment has been developed to enhance the hydrophilicity of PTFE using a mixture of acids and oxidizing agents. Moreover, surfactant was added to increase compatibility and improve impregnation. After the reinforced membrane was fabricated, the membranes were characterized, including their water uptake and dimensional stability. The reinforced membrane also showed superior mechanical properties, including gas permeability, tensile strength, and dynamic mechanical analysis. To evaluate the degree of impregnation, the transparency of the reinforced membrane was checked for haziness and further analyzed with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) mapping to quantify the impregnation degree. Finally, the performance and durability of the reinforced membrane were measured by single-cell and wet-dry cycling tests.

Traditional Knowledge Evolution over Half of a Century: Local Herbal Resources and Their Changes in the Upper Susa Valley of Northwest Italy.

Susa Valley, located in the Italian Western Alps, has served as a meeting point for cultural, spiritual, and commercial exchange for a long period of history. The valley's role as one of the main connecting routes between south and southwestern Europe resulted in its acquisition of a rich traditional ecological knowledge. However, like other Italian mountainous valleys, this valley has suffered from abandonment and depopulation in the past 50 years. Our study aims to investigate the current ethnobotanical medicinal knowledge in the valley and to compare our findings with a study conducted over 50 years ago in the same area. In 2018, we conducted 30 in-depth semi-structured interviews on medicinal plants and food-medicines used in the Susa Valley. We documented 36 species, of which 21 species were used for medical purposes and 15 species were used as food-medicine. The comparison with the previous study on medicinal herbs conducted in 1970 in the valley demonstrated a significant decrease in both the knowledge and use of medicinal plants, which could be attributed to socioeconomic, cultural, and possibly environmental changes that occurred in the past half-century. Our study highlights several promising species for future use as nutraceuticals, food, and medicinal products, such as Taraxacum officinale, Urtica dioica, and Artemisia genipi.

Frank Partial Dislocations in Coplanar Ir/C Ultrathin Nanosheets Boost Hydrogen Evolution Reaction.

Developing highly active and stable acidic hydrogen evolution catalysts is of great significance and challenge for the long-term operation of commercial proton exchange membrane (PEM) electrolyzers. In this work, coplanar ultrathin nanosheets composed of rich-Frank partial dislocations (FPDs) are first synthesized. Ir nanoparticles and carbon (Dr-Ir/C NSs) use a nonequilibrium high-temperature thermal shock method (>1200 °C) and KBr template-assisted techniques. Dr-Ir/C NSs exhibit excellent hydrogen evolution reaction (HER) performance with a remarkably high mass activity of 6.64 A mg-1 at 50 mV, which is among the best Ir-based catalysts.In addition, Dr-Ir/C NSs are able to operate stably at 1.0 A cm-2 for 200 h as a cathode in a PEM electrolyser, and the original coplanar ultrathin nanosheets structure are maintained after the test, demonstrating excellent stability against stacking and agglomeration. Geometrical phase analysis and theoretical calculations show that the FPDs produce a 4% compressive strain in the Dr-Ir/C NSs, and the compressive strain weaken the adsorption of H* by Ir, thus increasing the intrinsic activity of the catalyst.

Anion Exchange Ionomers: Design Considerations and Recent Advances - An Electrochemical Perspective.

Alkaline-based electrochemical devices, such as anion exchange membrane (AEM)fuel cells and electrolyzers, are receiving increasing attention. However, while the catalysts and membrane are methodically studied, the ionomer is largely overlooked. In fact, most of the studies in alkaline electrolytes are conducted using the commercial proton exchange ionomer Nafion. The ionomer provides ionic conductivity; it is also essential for gas transport and water management, as well as for controlling the mechanical stability and the morphology of the catalyst layer. Moreover, the ionomer has distinct requirements that differ from those of anion-exchange membranes, such as a high gas permeability, and that depend on the specific electrode, such as water management. As a result, it is necessary to tailor the ionomer structure to the specific application in isolation and as part of the catalyst layer. In this review, an overview of the current state of the art for anion exchange ionomers is provided, summarizing their specific requirements and limitations in the context of AEM electrolyzers and fuel cells.

Application of Artificial Intelligence in E-commerce

The rapid development of artificial intelligence in recent years is directly reflected in commercial activity, where a large number of transactions are carried out, a significant amount of data is formed and processed about deliveries made, sales made, and customers served. This is also true of e-commerce, which is establishing itself as the dominant non-store form of commercial exchange. The rise of artificial intelligence is changing the way businesses approach e-commerce. The algorithms and systems powered by it enable e-retailers to make data-driven decisions, automate processes and offer personalized experiences that match the unique preferences of individual customers. The purpose of this paper is to present the essence, advantages and guidelines for the application of artificial intelligence in e-commerce, and on this basis, the challenges for online merchants in its implementation are presented. The paper provides a brief analysis of data from Statista on the areas where artificial intelligence is helping e-commerce.

Modulating Cation and Water Transports for Enhanced CO Electrolysis via Ionomer Coating.

Electrification of the chemical industry has been considered an enabler for energy transition on a massive scale. In this context, carbon monoxide electroreduction (COR) to produce multi-carbon (C2+ ) products is considered one of the forefront emerging technologies. The key challenge in COR comes from the excessive cation crossover to the cathode via electromigration and water diffusion, which limits CO availability and impedes product selectivity. Commercial anion exchange membrane (AEM) suppresses the electromigration of cations, however, suffers from water diffusion which facilitates cation crossover. Here, we tackled these problems emerging from cation crossover and water diffusion by directly depositing an ultrathin Nafion ionomer on the cathode (sputtered Cu) surface. Our approach enables full-cell energy efficiency of 21 % for converting CO into ethylene (C2 H4 ) at 100 mA/cm2 with over 200 hours of stable operation. We also exhibited record high energy efficiency for ethanol (C2 H5 OH) production with CO-to-C2 H5 OH electrolysis efficiency of 17 %. This approach to directly depositing ultrathin ionomer on the cathode to enhance system performance may benefit other electrochemical systems to overcome challenges associated with scalability, stability, and efficiency to produce high-value chemicals.

All-scale investigation of a commercial proton exchange membrane fuel cell with partially narrow channels

Flow field design and optimization are critical for the proton exchange membrane (PEM) fuel cells to meet the requirement of ultra-high power density commercial applications. However, the multi-physics transport mechanism inside such large-scale PEM fuel cells has not been fully understood. In this study, we have developed a three-dimensional (3D) PEM fuel cell model. It is first validated against the experimental data obtained from a small-size cell. Thereafter, based on this model, the performance characteristics of a large fuel cell (cell area: 245.76 cm2) assembled with a partially narrow flow field are elucidated, while the full bipolar plate (BP) and cell morphology are also considered. It is found that the partially narrow flow field can not only significantly increase the net power density of PEM fuel cells, but also effectively improve the uniform distribution of species with the staggered partially narrow (SPN) zone arrangement between adjacent channels. While this flow field can improve the cell performance, the blindly increasing of the narrow zone numbers may play a negative impact on the net power density due to the dramatic increase in pressure drop. Finally, the partially narrow channel can indeed provide improved drainage capacity.

Application of Public Service Dominant Logic Through Value Cocreation in the Commercial Exchange Program

This study examines a regional television broadcasting media company operating in Riau, Malay. This research was conducted to evaluate the problems in the company, especially the marketing used by the Riau Television company to provide facilities that support marketing in the Niaga Niaga Program. The research method is descriptive qualitative with primary and secondary data. This study used observation, interviews, and documentation as data collection methods. This study provides the results of an evaluation of the Bursa Niaga program from Riau Televisi, which creates shared value between broadcasters and users using the Public Service Dominant Logic or PDSL theory with the concept of Value Co-Creation implemented as an effort to develop marketing media from Riau Televisi. This research is expected to encourage Riau Television to degrowth the company, especially in marketing, which creates value on the social media that Riau Televisi uses.

Nitrate Uptake by Cellulose-Based Anion Exchange Polymers Derived from Wheat Straw

Nitrate contamination of ground water is a serious problem due to the intensive agricultural activities needed to feed the world’s growing population. While effective, drinking water treatment using commercial ion exchange polymers is often too expensive to be employed. At the same time, lignocellulosic waste from crop production—an abundant source of the renewable polymer cellulose—is often burned to clear fields. This results in not only adverse health outcomes, but also wastes a valuable resource. In this study, wheat straw was pretreated to extract cellulose, then selectively oxidized with periodate, crosslinked with an alkyl diamine (1,7-diaminoheptane or 1,10-diaminodecane), and functionalized with a quaternary ammonium compound ((2-aminoethyl)trimethyl ammonium chloride) to generate a cellulose-based anion exchange polymer. This polymer lowered aqueous nitrate concentrations to health-based drinking water standards. Unlike commercial ion exchange polymers, its synthesis did not require the use of toxic epichlorohydrin or flammable solvents. The pretreatment conditions did not significantly affect nitrate uptake, but the crosslinker chain length did, with polymers crosslinked with 1,10-diaminodecane showing no nitrate uptake. Agricultural-waste-based anion exchange polymers could accelerate progress toward the sustainable development goals by providing low-cost materials for nitrate removal from water.

Sorption and separation of Er and Y from phosphoric acid using commercial cation exchange resin; Amberlite IR-120

Sorption and separation of Er and Y from phosphoric acid using commercial cation exchange resin; Amberlite IR-120