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In this study, the isothermal and cyclic corrosion behaviours of Haynes 282 and Haynes 214 in a lithium molten salt were investigated at 650°C for 168 h and 7 thermal cycles, respectively; this was...

This paper studies an innovation tournament in which an organizer seeks solutions to an innovation-related problem from a number of independent agents. While agents exert efforts to improve their solutions, their outcomes are uncertain. We call an agent whose ex-post output contributes to the organizer's utility a contributor. We analyze a general model of uncertainty and utility functions with multiple contributors, and we show that these two factors play a crucial role in decision-making of agents and the organizer. Specifically, contrary to existing theories, increased competition in a tournament can have a positive impact on agents' incentives to exert effort when agents expect good outcomes with high likelihood, and a free-entry open tournament should be encouraged only when the problem is highly uncertain or the organizer seeks diverse solutions from many contributors. Our results are consistent with recent empirical evidence, hence helping to close a gap in the extant literature between theory and practice.

The high-temperature corrosion behavior of anode current collectors in liquid Ag under an oxidizing atmosphere was investigated. The weight gain in oxygen was higher than that of liquid Ag because of the effective barrier formed by Ag-rich layer coated on the corrosion layer. The thickness of the corrosion layer under oxygen was approximately twice that of the layer developed under liquid Ag because of the effective barrier originating from the Ag-rich layer. The corrosion products on the surface of the specimens in both oxygen and liquid Ag were Al2O3 and FeAl2O4 from 24 to 168 h. The surface morphology that was developed on the scale of the corroded layer represented a buckle structure in liquid Ag and a convoluted structure in oxygen, which resulted from the lateral growth of the oxide. This study proved the improved stability and cost-effectiveness of using FeCrAl alloy as a current collector in a solid oxide membrane system.

In this study, hot corrosion behaviours of Haynes 282 (H282), Nimonic 90 (N90), and Haynes HR160 (HR160) in LiCl-Li2O molten salt were investigated at 650 °C under argon atmosphere. The corrosion rate was in the order of H282

The electrolytic reduction of a spent oxide fuel involves the liberation of oxygen in a molten salt LiCl–Li2O electrolyte, which creates a corrosive environment for typical structural materials. In this study, the corrosion behaviors of Al–Y-coated specimens in a Li molten salt kept under an oxidizing atmosphere at 650 °C for 72 and 168 h were investigated. The weight loss fraction of the coated specimen to bare specimen was approximately 60% for 3% Li2O and 54% for 8% Li2O at 72 h, and approximately 38% for 3% Li2O and 30% for 8% Li2O at 168 h. Corrosion was induced in the LiCl–Li2O molten salt by the basic oxide ion O2− via the basic flux mechanism, and the corrosion product was found to be dependent on the activity of the O2− ion. The increase in weight loss may have been caused by the increase in the O2− concentration due to the increase in the Li2O concentration rather than being because of the increased reaction time. The Al–Y coating was found to be beneficial for hot corrosion resistance, which can be useful for handling high-temperature lithium molten salt under an oxidizing atmosphere.

This paper investigates how autonomous vehicles (AVs) may change the morning commute travel pattern and improve downtown parking. We develop a continuous-time traffic model that takes into account key economic deterrents to driving, such as parking fee and traffic congestion, and characterize the departure time and parking location (downtown or outside downtown parking area) patterns of commuters in equilibrium. To illustrate our results, our model is calibrated to data from Pittsburgh. For the calibrated model, our analysis shows that all AV commuters choose to park outside downtown, increasing both vehicle hours and vehicle miles traveled as compared to the case with all human-driven vehicles. This change increases the total system cost and suggests a potential downtown land-use change (e.g., repurposing downtown parking spots to commercial and residential areas) in Pittsburgh after mass adoption of AVs. To reduce the total system cost, a social planner may be interested in regulating commuters’ decisions by adjusting parking fees and/or imposing congestion tolls as a short-term measure, or adjusting infrastructure, e.g., converting downtown parking spaces to curbside drop-off spots for AVs. Our results indicate that these measures can reduce the total system cost substantially (e.g., up to 70% in our calibrated model).

This study investigated the high-temperature stability of CSZ, YSZ, and MSZ specimens in a CaCl2-CaF2-CaO molten salt at 1200 °C for the application of the materials as oxygen-ion-conducting solid-oxide membrane anodes in the electroreduction process of metal oxides. YSZ exhibited the lowest degradation among the tested specimens in a high-temperature stability test, whereas CSZ showed the highest degradation. The weight loss was not severe with concentrations of CaO up to 10 wt%. CSZ showed peaks for m-ZrO2, YSZ showed peaks for t-ZrO2 and CaZrO3, and MSZ showed peaks for t-ZrO2 and m-ZrO2 in 0 wt% CaO. In the case of 5 wt% CaO, all specimens exhibited m-ZrO2 and CaZrO3 peaks, In the cases of 10 wt% and 20 wt% CaO, CSZ and MSZ showed peaks for CaZrO3, and YSZ showed peaks for m-ZrO2 and CaZrO3. While CSZ and MSZ became significantly looser as the CaO concentration was increased to 10 wt%, YSZ became significantly denser due to the formation of a protective layer and attack dependent on the solubility of CaO in the molten CaCl2. In terms of long-term operation, YSZ was demonstrated to possess superior high-temperature stability compared to CSZ and MSZ, and CaO concentrations from 5 wt% to 10 wt% were found to be significantly more stable than other concentrations.

The isothermal and cyclic corrosion behavior of yttria (Y2O3)-stabilized zirconia (ZrO2) in a LiCl-Li2O molten salt were investigated at 650 °C in an argon atmosphere. During isothermal and cyclic ...

The isothermal and cyclic corrosion behaviors of magnesia-stabilized zirconia in a LiCl-Li2O molten salt were investigated at 650 °C in an argon atmosphere. The weights of as-received and corroded specimens were measured and the microstructures, morphologies, and chemical compositions were analyzed by scanning electron microscopy, X-ray energy dispersive spectroscopy, and X-ray diffraction. For processes where Li is formed at the cathode during electrolysis, the corrosion rate was about five times higher than those of isothermal and thermal cycling processes. During isothermal tests, the corrosion product Li2ZrO3 was formed after 216 h. During thermal cycling, Li2ZrO3 was not detected until after the completion of 14 cycles. There was no evidence of cracks, pores, or spallation on the corroded surfaces, except when Li was formed. We demonstrate that magnesia-stabilized zirconia is beneficial for increasing the hot corrosion resistance of structural materials subjected to high temperature molten salts containing Li2O.

Problem Definition: This paper examines whether, and if so, how much an online-offline return partnership between online retailers and third-party retailers with physical stores (or, “location partners”) generates additional value to location partners. Academic/Practical Relevance: Online shoppers often prefer to return products to stores rather than mailing them back. Many online retailers have recently started to collaborate with location partners to offer the store return option to their customers, and we quantify its economic benefit to a location partner. Methodology: We analyze proprietary datasets from Happy Returns (which provides return services for over 30 online retailers) and one of its location partners, using a panel difference-in-differences (DID) model. In our study, a treatment is the initiation of the return service at each of the location partner’s stores, and an outcome is the store and online channel performance of the location partner. We then explore the mechanisms of underlying customer behavior that drive these outcomes. Results: We find that the partnership increases the number of unique customers, sales volume, and revenue in both store and online channels. We identify two drivers for this improved performance: (1) the location partner acquires new customers in both store and online channels, and (2) existing customers change their shopping patterns only in the store channel after using the return service; in particular, they visit stores more often, purchase more items, and generate higher revenue after their first return service. Managerial Implications: We provide the first, direct empirical evidence of value to location partners from a return partnership, and as these partnerships become more prevalent, our findings have important managerial implications for location partners and online retailers alike.

Online shoppers often prefer to return items to stores (or “offline return”) than to mail them back. We study a new business practice, return partnership, wherein online retailers partner with store retailers to offer offline returns. We seek to identify when return partnerships benefit both store and online retailers. Customers are heterogeneous in their distance to a store, and they choose between the online and store channels for their initial purchase, and if needed, for exchanging or returning an online purchase. We find that online retailers have incentives to choose a store retailer who has a low overlap with the online retailer’s product range as in the case of Happy Returns – a service provider that partners with apparel online retailers and mostly housewares store retailers – since this limits the loss of online customers to the store retailer at the time of their offline return. We show that, contrary to initial intuition, return partnerships may also feature retailers with high product overlap as in the case of Amazon-Kohl’s. In this case, the high overlap causes some store customers to migrate to shopping online, thereby keeping an online retailer’s incentive to partner. However, this migration of store customers to online limits the incentive of a store retailer with many stores because the added convenience induces a store visit from these customers only if they need to return items. Thus, we caution that with large overlap in product offerings, offline returns should not be too convenient for a partnership to form.

Measures to limit the spread of COVID-19 have impacted retailers greatly. While many retailers temporarily closed their physical stores – due to stay-at-home orders and mandatory non-essential business closures – some online-only retailers witnessed higher sales. An omnichannel retailer is exposed to both of these effects, and in addition, may be affected by the channel-shift of its existing customers from stores to online. Using a proprietary dataset, we provide the first empirical evidence of the impact of COVID-19, particularly government interventions, on an omnichannel retailer’s performance. We find that online sales increase, driven both by the acquisition of new customers and by online purchases from existing customers who previously purchased items primarily at physical stores. In contrast to the latter effect, online purchases from existing customers who used to purchase primarily online did not change. The retailer also benefits significantly from introducing an essential product (e.g., hand sanitizer) into its portfolio, even though it is not part of its core assortment: the essential product helps the retailer acquire new customers and induces previously offline-leaning customers to shop online. Our study reiterates how being omnichannel can help the retailer adapt during a pandemic, and offers useful tactical suggestions for managers; for example, targeted advertising of the retailer’s online channel could be combined with new customer promotions in high-income areas.

In this study, the isothermal and cyclic corrosion behaviors of custom-made nickel-based alloys (N105, N107, and N108) with various elemental compositions in a LiCl-Li2O molten salt were investigated at 650 °C in argon atmosphere. The isothermal and cyclic corrosion behaviors were studied by measuring the mass changes, surface morphologies, cross-sectional morphologies with elemental distribution, and the compositional changes of the subscale and substrate as well as the spalled oxide scale. Under the isothermal and cyclic corrosion test, the corrosion rate was in the order of N108

In this study, the feasibility of yttria-stabilized zirconia (YSZ) was investigated for use as a ceramic material, which can be commonly used for both electrolytic reduction and electrorefining. First, the stability of YSZ in salts for electrolytic reduction and electrorefining was examined. Then, its stability was demonstrated by a series of pyroprocessing tests, such as electrolytic reduction, LiCl distillation, electrorefining, and LiCl KCl distillation, using a single stainless steel wire mesh basket containing fuel and YSZ. A single basket was used by its transportation from one test to subsequent tests without the requirements for unloading.

This paper reports a promising method to decrease the operating temperature during electrolysis of natural ilmenite to produce a porous and laminar flake-type intermetallic ferrotitanium (FexTi, x = 1, 2) with a thickness of less than 1 μm by choosing a LiCl-Li2O electrolyte with a lower operating temperature (625 °C) under an inert atmosphere. Results indicate that the Li2O content in the electrolyte has a key effect on the phase transformation of natural ilmenite occurring in the electrochemical reduction process. Full conversion of natural ilmenite into ferrotitanium products can be achieved when the Li2O amount in the electrolyte and the cell voltage are approximately 1 wt.% and −2.5 V, respectively. In addition, the electrochemical reduction mechanism of natural ilmenite is proposed and discussed based on our experimental results and thermodynamic analysis.

The electrochemical behavior of Nd fluoride complexes for Nd electrowinning has been investigated according to the electrolyte composition in the LiF-NdF3 system. The electrochemical characteristics of the LiF-NdF3 electrolyte at low oxygen potential under acidic conditions and the LiF-NdF3-Nd2O3 electrolyte at high oxygen potential under basic conditions were also studied. The Nd fluoride complex behavior in the electrolyte was investigated by cyclic voltammetry for a concentration change of NdF3 with LiF at 1100 °C from 10 wt% to 64.6 wt%. The experimental results indicated that NdF3 is reduced to Nd(0) via a multi-step process. NdF2 could be produced by the comproportionation reaction between NdF3 and Nd metal. Additionally, the rate equation for NdF2 generation was derived through a reactivity test between the metal and the Nd2O3-free electrolyte. However, NdF2 production was suppressed in LiF-NdF3-Nd2O3 electrolyte.

The hot corrosion behaviour of YSZ specimens sintered at 1500 °C (6 and 11 h) and 1600 °C (11 h) was evaluated in CaCl2-CaF2-CaO molten salt at 1150 °C. YSZ sintered at 1600 °C for 11 h exhibited the lowest corrosion, whereas YSZ sintered at 1500 °C for 6 h showed the most corrosion, with a grain size dependency. XRD analysis showed that all YSZ contained mainly CaZrO3 with a small t-ZrO2 peak. To use SOM anodes for the electrowinning of various metals, the corrosion resistance of YSZ can be improved by adjusting the grain size instead of adding stabilizers.

Among metal waste generated during the dismantling of a nuclear power plant, the steam generator, which is the main component of nickel alloy contaminated by Co-60, is classified as large-scale waste. Therefore, for the decontamination of cobalt in a contaminated nickel alloy, the separation behavior of nickel and cobalt in a LiCl-KCl molten salt containing NiCl2 was investigated at 550 °C. Cyclic voltammetry (CV) measurements were recorded for determining the electrochemical properties of Ni and Co in molten salt. As CoCl2 was added into the salt, the reduction peak of cobalt was observed. However, the oxidation peak of cobalt could not be observed owing to the dissolution of the cobalt resulting from the chemical reaction with NiCl2. The highest separation factor of Co to Ni was calculated to be 1394 when the Ni2+/Co2+ ratio was 4, which indicated that Ni and Co can be separated. Therefore, the possibility of its application in the radioactive waste of Ni alloys from a steam generator via electrorefining using molten salt technology was confirmed.

Rising supply chain costs are one of the major factors that have caused rapid growth in overall healthcare spending. Supply chains in the healthcare industry are difficult to manage particularly due to their complexity and the uncertainties involved. This chapter starts with an overview of the unique challenges in healthcare supply chains, followed by an extensive review of past research in this area. We then demonstrate how inefficiency in healthcare supply chains can be improved through contract redesign, using two specific research examples: one for generic injectable drugs and the other for influenza vaccines. The chapter concludes with discussions of future research opportunities and directions.