Equilibrium Product Research Articles

Carbon-neutral synfuel production via continuous solar H2O and CO2 gasification of oil palm empty fruit bunch

Solar gasification offers a promising carbon-neutral pathway to thermochemically convert waste biomass and solar energy into synfuel. In this study, a thermodynamic analysis of solar gasification of oil palm empty fruit bunch (EFB) with H2O and CO2 gasifying agents was first performed to predict equilibrium product distribution. Subsequently, on-sun continuous solar gasification of EFB was experimentally carried out in a solar particle-fed gasifier to evaluate the influence of gasifying agent types (H2O and CO2), gasifying agent/EFB molar ratios (1.8–3.4), temperatures (1050–1350 °C), and to assess overall process feasibility and reliability. As a result, solar EFB gasification performed efficiently with both H2O and CO2 gasifying agents under continuous on-sun operation. Syngas product composition and gasification reaction rate strongly depended on gasifying agent type. Increasing temperature enhanced syngas yield and quality, and changed the CO/H2 mole ratio, especially in EFB + CO2 gasification. A gasifying agent/EFB molar ratio of 2.6 (slight excess of gasifying agents) and a temperature of 1300 °C were shown to be optimal for continuous solar EFB gasification. The maximum total syngas yield above 76 mmol/gdry_EFB, syngas lower heating value above 22 kJ/gdry_EFB, and energy upgrade factor above 1.37 were achieved from both EFB + H2O and EFB + CO2 gasification, which closely approached their theoretical equilibrium values. The maximum carbon conversion exceeding 93% and solar-to-fuel energy conversion efficiency up to 19.3% were achieved, demonstrating efficient EFB-to-synfuel conversion performance. Continuous solar EFB gasification with both H2O and CO2 was thus established to be a reliable process for EFB waste biomass valorization into high-quality and carbon-neutral synfuel.

Predicting the Equilibrium Product Formation in Oxy-fuel Combustion of Octane (C8H18) using Numerical Modeling

Preserving the environment is a major challenge for modern society, and reducing the greenhouse effect caused by combustion processes is a primary concern. It is known that nitrogen compounds (NOx) negatively impact air quality and public health. Internal combustion engines, responsible for nearly half of the atmosphere's pollutants, have prompted public policymakers to phase out gasoline and diesel-powered vehicles in the near future. Carbon capture and storage technologies, including oxy-fuel combustion, are being developed to address these environmental challenges. To predict exhaust pollutants such as NO and CO, assuming that the exhaust gases resulting from fuel and air combustion are in chemical equilibrium is a useful approximation. In the current case study, a numerical investigation on the impact of modifying the oxygen content of the reaction mixture from 21% to 100% on the equilibrium composition of C8H18 air-enriched combustion was conducted. Specifically, the equilibrium-constant approach routines were tailored for 10 species reported in the literature to the conditions of oxy-fuel combustion. Additionally, a comprehensive analysis was performed by varying the temperature and equivalence ratio alongside the oxygen level. The results emphasize the intricate interplay between various factors in oxy-combustion and provide valuable insight into the equilibrium product formation in oxy-fuel combustion. Notably, the non-uniform reduction of N2 as a function of O2 is highlighted, with an overall reduction rate of 0.93 observed across the range of O2 percentages from 21% to 99%.

Climate change and river water pollution: An application to the Ganges in Kanpur

AbstractWe provide a theoretical framework to analyze how climate change influences the Ganges and how this influence affects pollution in the river caused by tanneries in Kanpur, India. We focus on two tanneries, and that are situated on the same bank of the Ganges in Kanpur. Both produce leather and leather production requires the use of noxious chemicals. Tannery is situated upstream from tannery Tannery leather production depends on labor use but tannery leather production depends on labor use, the chemical waste generated by tannery and the natural pollution absorbing capacity of the Ganges. In this setting, we perform four tasks. First, we construct a metric that measures the climate change induced mean reduction in the natural capacity of the Ganges to absorb pollution in the time interval Second, we use this metric and determine the equilibrium production of leather by both tanneries in the benchmark case in which there is no pollution. Third, we ascertain how the benchmark equilibrium is altered when tannery accounts for the negative externality foisted upon it by tannery Finally, we study the impact on leather production and on labor use when the two tanneries merge and then discuss the policy implications stemming from our research.

Information sharing and production timing strategy in a platform‐based supply chain

AbstractThe e‐commerce platform has been adopting the agency mode to sell the products of the national brand manufacturer (NBM) while introducing its own store brand and obtaining the consumer's preference information (CPI) to reinforce the competitiveness of the store‐brand products. This paper investigates the platform's decisions on whether to share the CPI with the NBM and its impact on the production timing decisions of the platform and the NBM. The results show that the platform may benefit from CPI sharing which may also change the equilibrium production timing of the platform and the NBM from sequential decision to simultaneous decision. In addition, the equilibria of the joint decision between the CPI sharing and the production timing are obtained, which is related to the market acceptance uncertainties of the products and the competitiveness of the national brands.

Evaluation of Re/99mTc-labeled somatostatin receptor-targeting peptide complexes synthesized via direct metal cyclization

Abstract With interest in the development of somatostatin receptor (SSTR) targeting agents for potential application in diagnostic SPECT imaging (99mTc) or Peptide Radionuclide Receptor Therapy (PRRT, 186Re or 188Re) of neuroendocrine tumors, we present herein 99mTc/Re (radio)complexes synthesized by the integrated (radio)labeling approach of peptide cyclization via metal complexation. In particular, we utilized the potent SSTR2 peptide antagonist sequence DOTA-4-NO2-Phe-c(DCys-Tyr-DTrp-Lys-Thr-Cys)-DTyr-NH2 (DOTA-sst2-ANT) and report the syntheses and in vitro evaluations of its respective [99mTc]Tc/Re-cyclized peptides ([99mTc]Tc/Re-cyc-DOTA-sst2-ANT). The Re-cyc-DOTA-sst2-ANT complex was synthesized via an on-resin Re(V)-cyclization reaction using the ReOCl3(PPh3)2 precursor and consisted of three isomers characterized by LC–ESI-MS. The [99mTc]Tc-cyclized analogue was prepared via a ligand exchange reaction of the [99mTc][TcO]3+ core through a [99mTc]Tc-glucoheptonate intermediate with linear DOTA-sst2-ANT and was characterized by comparative HPLC studies against Re-cyc-DOTA-sst2-ANT. Good in vitro binding affinity was demonstrated in SSTR-expressing cells (AR42J) by the Re-cyc-DOTA-sst2-ANT major isomer, similar to the potent binder Lu-DOTA-sst2-ANT, in which the Lu metal was complexed by the bifunctional chelator DOTA versus via peptide cyclization. [99mTc]Tc-cyc-DOTA-sst2-ANT was obtained in high radiochemical yield, also with an elution pattern of three isomers observed by HPLC analysis, which were comparable yet not identical to those of Re-cyc-DOTA-sst2-ANT. The [99mTc]Tc-tracer complex was shown to be hydrophilic, and stability studies at 4 h demonstrated that it remained intact in both PBS and in rat serum, with low non-specific rat serum protein binding, while exhibiting more moderate stability in 1 mM cysteine. These findings demonstrate that direct Re/[99mTc]Tc-cyclization of DOTA-sst2-ANT is feasible and may be used as an alternative approach to the bifunctional chelate labeling strategy. However, given that the non-radioactive (Re) and radiotracer (99mTc) analogues are not identical and both form isomeric products in equilibrium, additional design modifications will be necessary prior to in vivo application of [99mTc]Tc/Re-cyc-DOTA-sst2-ANT.

Economic Feasibility of Management of Fertilization in the Soybean-Corn System Cultivated in Succession

Fertilization management is one of the agricultural practices that demand high investment. Thus, the objective was to evaluate the economic viability of using combinations of fertilizers applied to soybean and corn cultivated in succession in Goiás Savanna soil. The experiment was carried out in the field, in randomized blocks. The fertilization management consisted of the combination of monoammonium phosphate fertilizers; urea; 08:40:00 +9.3%S and 3.2% Ca; simple superphosphate; potassium chloride; elemental sulfur; polyhalite (37% K2O + 9.2% S, 5.8% Ca and 1.7% Mg) and polyhalite S (14% K2O + 19.2% S, 12% Ca and 3.6% Mg) which were applied in soybean sowing and evaluated the residual effect on corn. The economic assessment took into account crop productivity and fertilizer prices in the 2018/2019 agricultural year. For each treatment, the operating cost (COi) and profitability indicators were calculated: gross revenue (GRi); net revenue (NRi); profitability index (PITi); equilibrium production (Yei) and equilibrium price (Pei). Crop productivity was not influenced by fertilizer management, showing that economic indicators can help producers choose the management with the best return and that adjusts to the financial situation of the rural company. Thus, it is concluded that the management of MAP + KCl fertilization was economically outstanding in soybean cultivation and the MAP/S + KCl applied to soybeans, associated with nitrogen fertilization in corn coverage was the most viable for off-season corn. The economic indicators showed that the MAP+KCl fertilization performed on soybean, associated with urea in corn coverage, is the most viable management system for the soybean-corn production system cultivated in succession.

Shape-Selectivity of Cyclopentenyl Cation Isomerization: Investigating Kinetic Control in Medium-Pore Zeolites

We performed periodic density functional theory (DFT) calculations to study the dynamics of alkyl substituents on cyclopentenyl cations in medium-pore acid zeolites, H-ZSM-5 and H-ZSM-22. Our study seeks to shed light on how zeolite shape selectivity can influence key reaction intermediates in the methanol-to-hydrocarbon process, which can lead to both value-added products and coke species. We considered the isomerization of 4-ethyl-4,5,5-trimethylcyclopentenyl cation (A), which has been shown by Hernandez et al. [ACS Catal.2021, 11, 12893–12914] to lead to IR spectra and alkyl substitution patterns that vary with zeolite pore structure, in contrast to DFT-predicted thermodynamics. Here, we investigate the role of kinetic control on zeolite shape-selectivity by computing exhaustive DFT dynamics of substituent rearrangement in medium-pore zeolites starting with cation A. We used the Rule Input Network Generator (RING) code to enumerate isomerization pathways from A to five product isomers that differ mainly in the presence or absence of an alkyl substituent on the central allylic carbon of the cyclopentenyl ring, yielding a reaction network with a total of 24 distinct species. We combined metadynamics and climbing-image nudged elastic band (CI-NEB) methods to compute the free-energy landscapes, including barriers for all species in H-ZSM-5 and H-ZSM-22 zeolites. Integrating kinetic equations for the reaction network in the two zeolites predicts that equilibrium product distributions are obtained after 103 s in H-ZSM-5, while 108–109 s is required for equilibration in H-ZSM-22, suggesting the clear possibility of kinetic control depending on zeolite structure.

R&D investments with spillovers and endogenous horizontal differentiation

We investigate the implications of cost-reducing R&D activities with spillovers in a Hotelling model with endogenous product differentiation driven by quadratic transportation costs. We consider two different three-stage games: in the first, firms choose locations, then R&D efforts and finally prices; in the second, R&D strategies are decided at the first stage and locations are chosen at the second, with price competition taking place at the third. We identify the conditions whereby process innovation brings about a reduction of product differentiation in equilibrium, consequently implying lower profits. Equilibrium product differentiation and profits are increasing in R&D spillovers. Then, transforming the structure into a twofold version of a four-stage game, we allow firms to commit not to invest in R&D, to show the presence of an underlying prisoners’ dilemma affecting R&D decisions. Finally, we illustrate R&D cartels’ ability to eliminate wasteful sunk costs, and outline policy prescriptions.

Tanneries in Kanpur and pollution in the Ganges: A theoretical analysis

AbstractWe study pollution in the Ganges River caused by tanneries in the City of Kanpur in India. Two tanneries, and , are located on the same bank of the Ganges in Kanpur. Both produce leather, and the production of leather requires the use of chemicals that are toxic to humans. Tannery is located upstream from tannery Tannery 's leather production directly depends only on labor use, while tannery 's leather production depends on labor use, the chemical waste generated by tannery and the natural pollution‐absorbing capacity of the Ganges. In this setting, we accomplish three tasks. First, we determine the equilibrium production of leather by both tanneries in the benchmark case in which there is no pollution. Second, we ascertain how the benchmark equilibrium is altered when tannery accounts for the negative externality imposed on it by tannery Finally, we analyze what happens to leather production and to labor use when the two tanneries merge and discuss some policy implications stemming from our research.

Enhancing the online buyer perception of consumer experience products in a dual-channel supply chain: A new role of free-riding

Asymmetries in consumer perceptions about the quality of a consumer experience product are prevalent between online (direct) and offline (brick-and-mortar) retail channels of a manufacturer. Often, online customers underrate product quality due to a lack of firsthand (touch-and-feel) experience, while retail (offline) customers not only experience the product at the stores but also enjoy retail services. In a dual-channel supply chain, we investigate a new role of free-riding under which online customers improve their perception of product quality and explore its effect on product quality and retail service level decisions. We analytically derive equilibrium product quality, retail service level, and pricing strategies in both the centralized and decentralized supply chains. Free-riding not only improves online customers’ perception of product quality but could also induce the manufacturer to improve product quality in both centralized and decentralized models. Although free-riding can lower the level of retail services in the decentralized model, it can produce higher retail services in the centralized model when the degree of free-riding is higher. We develop an effective contract to coordinate the decentralized supply chain, which allows the manufacturer and retailer to share not only the profits from both channels but also the costs of product quality and retail services. Additionally, we extend the study to incorporate demand disruptions into the model and examine their impact.

A Maximum Principle Approach to a Deterministic Mean Field Game of Control with Absorption

We study a deterministic mean field game on finite and infinite time horizons arising in models of optimal exploitation of exhaustible resources. The main characteristic of our game is an absorption constraint on the players' state process. As a result of the state constraint the optimal time of absorption becomes part of the equilibrium. Using Pontryagin's maximum principle, we prove the existence and uniqueness of equilibria and solve the infinite horizon models in closed form. As players may drop out of the game over time, equilibrium production rates need not be monotone nor smooth.

Resonance production in partial chemical equilibrium

In high energy collisions, a dense, strongly interacting medium could be created, the quark gluon plasma. In rapid expansion, from the soup of quarks and gluons a gas of resonance and stable particles is formed at the chemical freeze-out and after that, as the system cools down, the kinetic freeze-out takes place and interaction between particles ceases. By measuring resonance ratios one could get information about the dominant physical processes in the intermediate temperature ranges, i.e. between the chemical and kinetic freeze-out. These quantities are measured at RHIC and LHC energies. In the present analysis we employ the hadron resonance gas model assuming partial chemical equilibrium to characterize these measured data. We calculate the ratios of several resonances to their stable counterpart and compare these model calculations to available experimental data.

Implications of Online-Buying to Store-Pickup (O2S) for End-to-End Supply Chain Strategy

A growing body of literature examines the demand effects of the increasingly popular retailing strategies of integrating digital sales channels with brick-and-mortar stores, allowing customers to buy goods online and pick them up in a store (termed BOPS) or by the store’s curbside. Typically, however, implications of such strategies are explored for the retail channel alone while ignoring the sourcing strategy, which affects a key driver of their influence: product availability. We study such online-to-store (O2S) strategies using an analytical model of the end-to-end supply chain for two cases: a brick-and-mortar retailer expanding its market via O2S, and a retailer integrating its independent brick-and-mortar and online channels via O2S. We derive rational expectations equilibrium product availability, involving sourcing strategy and consumer choice, in pre and post-O2S cases to provide three insights about the interdependence of O2S and sourcing strategies. First, market expansion via O2S is moderated by the retailer’s sourcing strategy: it is achieved only if the equilibrium pre-O2S product availability is below a certain threshold. Second, introduction of an O2S strategy can affect the feasibility of retailer’s suppliers: it can render an existing supplier economically infeasible and make a previously-infeasible supplier feasible. Third, cost-efficient processing of goods returned by the retailer’s O2S and online consumers is necessary not just for retail profitability but also to ensure supplier feasibility. For practice, this highlights the need to plan the retail and sourcing strategies in a multi-channel environment jointly as interdependent components of an end-to-end supply chain. Managers are thus forewarned of pitfalls from separating the decision-making in retailing and sourcing strategies.

Equilibrium CEO contract with belief heterogeneity

Consider a firm owned by shareholders with heterogeneous beliefs and run by a manager who chooses random production plans. Shareholders do not observe the chosen plan but only its realization. The financial market consists of assets contingent on production realizations. A contract for the manager specifies her compensation as a function of the firm’s production and possibly some restrictions to trade in the financial market. Shareholders are unrestricted. We define a concept of equilibrium between the manager and shareholders such that the equilibrium production plan is unanimously preferred by the manager and the shareholders, markets clear and the manager has no incentive to cheat. We first analyze the properties of such equilibria and in particular show that the contract should restrict the manager from trading. We next provide a framework where such equilibria exist. We lastly study the properties of equilibrium compensations when shareholders have beliefs that can be ranked in terms of optimism towards the equilibrium plan. Specific attention is given to their departure from linear compensations.

A General Framework for Learning Mean-Field Games

This paper presents a general mean-field game (GMFG) framework for simultaneous learning and decision making in stochastic games with a large population. It first establishes the existence of a unique Nash equilibrium to this GMFG, and it demonstrates that naively combining reinforcement learning with the fixed-point approach in classical mean-field games yields unstable algorithms. It then proposes value-based and policy-based reinforcement learning algorithms (GMF-V and GMF-P, respectively) with smoothed policies, with analysis of their convergence properties and computational complexities. Experiments on an equilibrium product pricing problem demonstrate that two specific instantiations of GMF-V with Q-learning and GMF-P with trust region policy optimization—GMF-V-Q and GMF-P-TRPO, respectively—are both efficient and robust in the GMFG setting. Moreover, their performance is superior in convergence speed, accuracy, and stability when compared with existing algorithms for multiagent reinforcement learning in the N-player setting. Funding: X. Guo acknowledges the generous support from Coleman Fung Chair endowment fund and the Tsinghua-Berkeley-Shenzhen-Institute.

Effects of Reactive Capacity on Product Quality and Firm Profitability in an Uncertain Market

How Reactive Capacity Affects Product Quality and Firm Profitability The COVID-19 pandemic exacerbates both supply and demand uncertainties, which have strategically influenced firms’ product quality and targeting decisions. For example, during the pandemic, automakers faced supply shortages for automotive chips because of the upstream suppliers’ limited parts inventory and production capacities, which have prompted the automakers to increase the quality (e.g., producing higher trims with more optional upgrade features) and price of their products to target fewer (high-valuation) consumers. In “Effects of Reactive Capacity on Product Quality and Firm Profitability in an Uncertain Market,” Jiang and Tian study the impacts of the supplier’s reactive capacity and demand uncertainty on product quality and firm profitability under pull contracts in the supply chain. They find that an increase in the supplier’s reactive capacity can lead to higher or lower equilibrium product quality, benefiting the retailer but potentially reducing the supplier’s profit. Interestingly, both the retailer and the supplier can be worse off with a higher probability for the high market state (with more high-valuation consumers). Further, a higher probability for the high market state can lead to lower product quality.

Capacity Investment and Process Efficiency at Flexible Firms

When firms are endowed with volume flexibility, capacity investment may influence the subsequent production process via affecting the structure of production cost. Yet, the strategic interaction between capacity and production decisions has not been adequately addressed. In this paper, we consider two firms serving one market under price sensitive and uncertain demand. Firms incur costs to build capacity and produce. The firm’s capacity affects production cost through its influence on process efficiency, while the specific effects on the two firms differ. We establish a two-stage game-theoretical framework to characterize the problem and obtain two firms’ equilibrium capacity and production decisions. The results show that the firm whose process efficiency is more prone to improving as capacity expands will invest in more capacity and achieve a more efficient process, provided that production is not overly labor and material intensive. However, its competitor will spin off capacity and suffer profit reduction. Moreover, the firms are encouraged to scale up capacity investment to achieve a more efficient process in an expanding and more volatile market.

A Supplier Selection Model Using Alternative Ranking Process by Alternatives’ Stability Scores and the Grey Equilibrium Product

Supply chain management begins with supplier evaluation and selection. The supplier selection deals with various criteria with different contexts which makes it a complex multi-criteria decision-making (MCDM) method. In this paper, a novel MCDM method, called the alternative ranking process by alternatives’ stability scores (ARPASS), is proposed to solve supplier selection problems. ARPASS considers each alternative as a system that is constructed on integrated components. To perform properly, a system requires high integrity and stability. ARPASS utilizes the stability of alternatives as an effective element for ranking the alternatives. The ARPASS is developed in two forms, ARPASS and ARPASS*. The new method utilizes standard deviations and Shannon’s entropy to compute the alternatives’ stabilities. In this paper, in addition to the new MCDM methods, a new method called the grey equilibrium product (GEP) is introduced to convert grey linguistic variables into crisp values, using decision makers’ subjective perceptions and judgments. To highlight and validate the novel methods’ performance, they are applied to two sustainable supplier selection problems. For evaluation of the reliability of ARPASS and ARPASS*, their results were compared with the results of the popular MCDM methods. We compared the methods in terms of calculation time, simplicity, transparency, and information type.

Equilibrium Composition of Products Formed by Non-catalytic Conversion of Hydrocarbons

The kinetic patterns of the attainment of the equilibrium product composition in non-catalytic processes of partial oxidation and of steam and carbon dioxide reforming of hydrocarbons in the temperature range 1400–1800 K, characteristic of these processes, were analyzed. The need for such analysis is caused by the rapidly increasing consumption of natural gas as a chemical feedstock and by growing attention to environmental problems, in particular, to a decrease in СО2 emissions or to partial CO2 utilization. The forward and reverse water gas shift reactions (WGSRs) play an important role in approach to the equilibrium product composition in these processes. Analysis has shown that the elementary reactions characteristic of forward and reverse WGSRs start to play a significant role long before the equilibrium in the system is attained. Already in the intermediate steps of the process, the distribution of the major reaction products, Н2, СО, Н2О, and СО2, almost corresponds to the equilibrium value of Kt = ([H2][CO2])/([CO][H2O]), close to the WGSR equilibrium constant Keq, and further conversion of the products occurs at Kt values close to Keq.

Rethinking Varieties of Capitalism and growth theory in the ICT era*

Going beyond the Varieties of Capitalism comparative analysis, a theory of advanced capitalism is developed to explain what has been driving advanced capitalism through the massive creative destruction of the information and communication technologies (ICT) revolution of recent decades. Second, it is argued – reconfiguring Varieties of Capitalism – that the advanced capitalist economies should be seen not just in terms of comparative capitalisms, but as an advanced world innovation system of interacting advanced economies. Critically, the dominant position in that system is the (hegemonic but also fragile, problematic and handicapped) United States as the world driver of radical innovation: this reflects the key role of its top research universities, their diasporas and associated deregulated high-risk-taking venture capitalist and investment banking ecosystems; its decentralised and business-porous political and legal systems; and its dominance ab initio of digitalisation. Problematic has been the major reduction since the early 1990s in Federal R&D, itself a consequence of the anti-public-expenditure Republican gridlock in Congress, and in turn the result of the political, geographical and socioeconomic polarisation associated with technological creative destruction more dramatically in the US than elsewhere. Third, it addresses the paradox – in the contemporary technologically revolutionary age – of productivity growth falling below that of the Fordist era. It is argued that Schumpeterian growth expectations play a much larger role in R&D investment in the high-sunk-cost and high-risk US-centred ICT era than in the relative stability of Fordism and Chandlerian corporations; the author sets out a simple Keynesian–Kaldorian expectations-based multiple equilibrium productivity growth model, where major crashes shift economies down to lower growth equilibria. The conclusion raises six areas of future work which stem from the approaches outlined above.