Competitive Paths Research Articles

Theoretical investigations on the properties of graphene supported metal (Al, Zn, Fe) catalysts and the reaction mechanism of catalyzing water to hydrogen peroxide

AbstractIn this paper, density functional theory (DFT) was used to study the reaction mechanism of the production of hydrogen peroxide from oxygen and water catalyzed by graphene supported metal (Al, Zn, and Fe) catalysts. By comparing the supported stability of metal at different sites on graphene surface, the optimal support sites are determined and then a stable catalyst model is selected. Two different reaction paths for the synthesis of hydrogen peroxide and a competitive reaction path for the generation of hydrogen are discussed, the microscopic reaction mechanism of the synthesis of hydrogen peroxide catalyzed by water and oxygen is investigated in detail. The stable structures of reactants, intermediates, and products in each path are optimized. By comparing the activation energies of different reaction paths, the optimal reaction paths are obtained, and the possibility of side reaction products is predicted. At the same time, the electron density, band structure, and density of states characteristics of these graphene supported metal catalysts are studied. The correlation between the physical properties of the three catalysts and their catalytic performances is analyzed. It is predicted that Al, Zn, and Fe catalysts supported by graphene may have the ability to directly generate hydrogen peroxide in industrial wastewater treatment.

Investigation of the oxygen coverage of propylene epoxidation on Ag(1 1 1) surfaces from DFT

The direct epoxidation of propylene on Ag(111) under different oxygen coverage conditions was systemically studied on the basis of density functional theory calculation and the general trends of oxygen coverage on the two parallel competitive reaction paths in propylene oxide (PO) formation: α-H stripping versus epoxidation and the generation of PO versus acetone (AC) were explored. Then, the PO formation selectivity was investigated. Results showed that increase in oxygen coverage enhanced the adsorption strength of adsorbed species, except the O* species. In the primary reaction of propylene epoxidation, high oxygen coverage facilitates the first α-H stripping process, and opposite trend was observed in epoxidation process. As for the secondary chemistry in propylene epoxidation, increase in oxygen coverage benefits PO and AC formation. The coverage of O* has considerable influences on the primary reaction but small influence on the secondary reaction. Although a high oxygen coverage benefits the first α-H stripping, the second α-H stripping has higher barrier than that in secondary chemistry, and thus the PO formation would be better than that of acrolein formation at higher oxygen coverage.

FM2 Path Planner for UAV Applications with Curvature Constraints: A Comparative Analysis with Other Planning Approaches.

This paper studies the Fast Marching Square () method as a competitive path planner for UAV applications. The approach fulfills trajectory curvature constraints together with a significantly reduced computation time, which makes it overperform with respect to other planning methods of the literature based on optimization. A comparative analysis is presented to demonstrate how the approach can easily adapt its performance thanks to the introduction of two parameters, saturation and exponent , that allow a flexible configuration of the paths in terms of curvature restrictions, among others. The main contributions of the method are twofold: first, a feasible path is directly obtained without the need of a later optimization process to accomplish curvature restrictions; second, the computation speed is significantly increased, up to 220 times faster than other optimization-based methods such as, for instance, Dubins, Euler–Mumford Elastica and Reeds–Shepp. Simulation results are given to demonstrate the superiority of the method when used for UAV applications in comparison with the three previously mentioned methods.

Moisture‐Induced Non‐Equilibrium Phase Segregation in Triple Cation Mixed Halide Perovskite Monitored by In Situ Characterization Techniques and Solid‐State NMR

Environmental stability is a major bottleneck of perovskite solar cells. Only a handful of studies are investigating the effect of moisture on the structural degradation of the absorber. They mostly rely on ex situ experiments and on completely degraded samples, which restrict the assessment on initial and final stage. By combining in situ X‐ray diffraction under controlled 85% relative humidity, and live observations of the water‐induced degradation using liquid‐cell transmission electron microscopy, we reveal two competitive degradation paths leading on one hand to the decomposition of state‐of‐the‐art mixed cation/anion (Cs0.05(MA0.17FA0.83)0.95Pb(Br0.17I0.83)3 (CsMAFA) into PbI2 through a dissolution/recrystallization mechanism and, on the other hand, to a non‐equilibrium phase segregation leading to CsPb2Br5 and a Cesium‐poor/iodide‐rich Cs0.05‐x(MA0.17FA0.83)0.95Pb(Br0.17−2yI0.83+2y)3 perovskite. This degradation mechanism is corroborated at atomic‐scale resolution through solid‐state 1H and 133Cs NMR analysis. Exposure to moisture leads to a film containing important heterogeneities in terms of morphology, photoluminescence intensities, and lifetimes. Our results provide new insights and consensus that complex perovskite compositions, though very performant as champion devices, are comparatively metastable, a trait that limits the chances to achieve long‐term stability.

Research on the improvement path of international competitiveness of China's agricultural product supply chain from the perspective of machine learning

AbstractIn order to explore the international competitiveness of China's agricultural product supply chain, this paper combines machine learning algorithms to optimize the data processing process of agricultural product supply chain, and proposes a data processing method for agricultural product supply chain based on the intra‐column rules and inter‐column rules. According to the problems of my country's agricultural product supply chain, this paper establishes a new agricultural product supply chain management model based on the various modules of the supply chain link, and constructs a corresponding intelligent analysis model. Moreover, this paper combines machine learning algorithms to study the improvement path of the international competitiveness of China's agricultural product supply chain, and builds an intelligent model to improve the international competitiveness of China's agricultural products. Finally, after constructing the model, this paper obtains the path to improve the international competitiveness of China's agricultural products through the simulation operation model, which also verifies the effectiveness of the intelligent algorithm of this paper from the side.

Competitiveness in meso-level of biofortified foods in the south of Brazil

The dichotomy of micro and macro competitiveness presents some limitations as a result of the business arrangements experienced in the contemporary period. The systemic competitiveness in meso-level makes it possible to understand the interconnection between actors, involving private companies, nongovernmental entities and public policies for a particular arrangement or sector of the economy. The present study aims to analyze the Value Chain of biofortified foods in Southern Brazil, which enables to look at the link among players, based on the theory of competitiveness in meso-level approach. For that, a qualitative research was developed, with interviews being conducted, seeking to understand the participation of each player in the context of biofortified foods and the interactions and interrelationships to sustain the competitiveness of this segment in the south of Brazil. As a result, it is identified that the evolutionary path of competitiveness in bio-feed foods is found in the so-called origin phase, due to the development of initial rules, defined the meso-level conceptions with the interaction between the different actors, typical of the origin phase, but that needed to be adjusted, remodeling the relations and the insertion of new actors to maximize the competitiveness of the analyzed sector. The results also showed Meso-level activities in technology, training and education, finance, infrastructure, trading and associations have been contemplated by several of the studied players. There are also associations among the three main studied actors (Fundetec, Biolabore and Fundação Itaipu) for supporting rural producers. In relation to trade, it is carried out with multiple sources, including institutional purchases, as well as sales to industry and the final consumer. Technology is strongly being used in developing genetic material, monitoring systems and production and point of sales monitoring, as well as in the industrialization process. Despite several requirements in regard to meso-level competitiveness being met currently, its constitution is still pretty fragile, and several players perceived risks in the Project.

Prevailing charge transfer in the reaction of protonated and neutral nitric oxide: A theoretical and experimental study

The thermal gas-phase reaction of [NOH]+ with nitric oxide (NO) has been studied using FT-ICR mass spectrometry complemented by high level quantum chemical calculations. Among different competitive paths that may be envisioned, using D- and 15N labelling in the reagent species has allowed to unequivocally observe an exclusive electron transfer (ET) reactivity. This outcome is well accounted by the energy profile for the envisioned plausible pathways calculated at UCCSD(T)/aug-ccpVTZ//UB3LYP/def2-TZVP level of theory. The seemingly barrierless ET process (as predicted by classical Marcus theory) is exoergonic by 20.8 kcal/mol. The two reaction partners may alternatively yield an adduct, where a large extent of charge transfer has taken place. This [HNO⋅⋅⋅NO]+ adduct may proceed by undergoing transfer of hydrogen, entailing largely hydride character. However, in agreement with a calculated barrier of ca. 12 kcal/mol, no experimental evidence is obtained for the occurrence of this alternative route.

Explaining cost escalation on Ireland's national broadband plan: A path dependency perspective

Ireland's national broadband plan (NBP), announced in 2012, aimed to provide access to a minimum of 30 Mbps download speed to all households in the country ahead of the EU's Digital Agenda for Europe 2020 target for such speeds. The projected cost of the government subsidy was originally €175 million. However, when the contract for the procurement of the NBP was eventually signed in 2019 the estimated subsidy had risen to between €2.2 and €2.9 billion. Using a path dependency framework, this paper finds that the escalation in the cost of subsidy was driven by two main factors. First, the decision to roll out fibre-to-the-premises (FTTP) technology was inconsistent with the geographic/legacy path dependencies related to Ireland's low-density rural population. Second, the gap-funding/PPP procurement model adopted for the intervention failed to attract competitive bids and was at odds with the competitive path dependency and the dominant role of the incumbent operator.

Demystifying the role of internal dynamics in the path of innovative competitiveness: a serial mediation model of international joint ventures

PurposeThe study proposes and evaluates a parsimonious research framework by integrating the major strategic theories related to an international firm's internal dynamics. This research's essence lies in the proposition that organizational competencies, knowledge resources and processes, absorptive capacity and innovativeness form the underlying base for sustainable competitive advantage in this dynamic world.Design/methodology/approachA cross-sectional explanatory research design is adopted. Using the quantitative data obtained from the sample of Indian international joint ventures (IJVs), partial least squares structural equation modeling (PLS-SEM) is deployed to confirm the proposed relationships among the research constructs. Finally, qualitative interviews helped in triangulating the primary survey's results.FindingsA well-established relationship between knowledge transfer and innovation is negated by the Indian IJVs' data, which is delved deeper with cross-industry qualitative analysis. The novel hierarchical model with multiple mediations has nurtured quite exciting results for the business world with some significant theoretical and managerial implications.Research limitations/implicationsThis study has investigated the nexus between multi-dimensional organizational competencies, knowledge transfer, absorptive capacity and venture innovativeness in the context of Indian IJVs. It has emphasized the role of internal dynamics in cross-cultural joint ventures to attain sustainable competitiveness through strategic and technological efficiency.Originality/valueThe study has addressed the specific research gap of under-investigation of dynamic capabilities and sustainable competitiveness in international joint ventures. It has investigated a complex model of multiple mediations, yielding interesting quantitative results with qualitative insights; which is rare to match in literature.

The Design of Firms: Part 2 - Competitive Advantage

Abstract One of the essential aspects of a company's design is its source of competitive advantage. Extrapolating from Raymond Loewy's famous design strategy acronym, MAYA—the Most Advanced Yet Acceptable Principle—and treating the firm as the object of design, this article explains the competitive advantage of firms from a design perspective. Our design-based recommendation for the competitive advantage of firms is to focus on shaping heterogeneity-based advantages of the firm in ways its paying customers would deem valuable. The novelty and conventionality dynamics of its industry will influence the degree of heterogeneity of the firm. Firms can shape their heterogeneity-based advantages through policies relating to organizational structure, routines, and product portfolio to name a few. Going beyond the role of a design in creating rents above and beyond what other firms can imagine, our claim focuses on the ways in which heterogeneity is a fundamental driver of its competitive advantage. If correct, the design-based view suggests that the ideal level of heterogeneity of the firm relative to current competitive conditions and evolution paths adopted by the firm and its competitors is more fundamental to firm profitability than its resources.

A comprehensive review on catalytic O-alkylation of phenol and hydroquinone

ABSTRACT The alkylation process involves two competitive paths of O- and C-alkylation and achieving better selectivity for desired products is a very challenging problem. The development of new process for synthesis of O-methylated products of phenol and dihydric phenols is a subject of high industrial and academic interest. Alkyl phenyl ethers, especially anisole and 4-methoxyphenol, have captivated significant interest due to their increasing applications in pharmaceutical industries. The main emphasis of the present review is to explore the recent development in two catalytic O-alkylation processes. The first process is O-methylation of phenol into anisole and another is selective mono O-methylation of hydroquinone into 4-methoxyphenol. The present article covers O-alkylation methods with methanol and dimethyl carbonate as alkylating agent over various acidic and basic catalytic systems. The catalyst systems analyzed involves Bronsted and Lewis acidic and basic ionic liquids, conventional acids, metal oxides, solid acid and basic catalysts, hydrotalcites, various zeolites and heteropolyacids. The mechanistic behavior of alkylation reactions in presence of different catalytic system is reviewed critically which is important to design new and/or modified catalyst in order to maximize the yield of desired product. Additionally, an influence of reaction parameters, role of catalyst and their active sites on product distribution is described. The review paper gives useful insight for researchers in the field of catalysis and reaction engineering of alkylation reactions. Understandings of the reaction pathways will help in developing reliable kinetic models necessary for process scale-up to industrial scale reactor system.

IT Process Alignment in Business Strategy: Examining the Role of Transactional Leadership and Organization Culture

Information technology (IT) is a competitive path and offers the entrepreneurial opportunity of accumulating business knowledge in capturing consumer behavior. This study employed a conceptual framework to investigate the information processing facet of IT–business alignment under the impact mechanism of transactional leadership in the manufacturing sector of Yunnan Province, China. Specifically, organization culture is taken as a moderating factor extracted from situational theory and has been highlighted as important in previous organizational research. This study aimed at investigating the impact of transactional leadership on IT–business process alignment and studying the moderating effect of organizational culture on the relationship between transactional leadership and IT–business process alignment. The empirical findings reveal that contingent reward and management by exception behaviors of entrepreneurs are significant drivers of IT–business process alignment. Furthermore, market culture had a moderating effect on the relationship between entrepreneurs’ transactional behaviors and IT–business process alignment. Similarly, hierarchy culture exerts a moderating effect on the path between contingent rewarding behavior and IT–business process alignment. Here, it exerts an insignificant moderating effect on the management by exception behavior and IT–business process alignment path. The study findings mainly reveal the association of transactional leadership with IT–business process alignment, along with the moderating role of organizational culture. This study contributes to the literature on business knowledge by showcasing empirical evidence—how information processing aids entrepreneurial behavior to capture market opportunities and consumer behavior.

Radical Mechanism of Ir III /Ni II -Metallaphotoredox-Catalyzed C(sp 3 )–H Functionalization Triggered by Proton-Coupled Electron Transfer: Theoretical Insight

Photoredox catalysis can be induced to activate organic substrates or to modulate the oxidation state of transition-metal catalysts via unique single-electron transfer processes, so as to achieve c...

Locomotive Model for International Competitive Advantages Paths of High-Speed Railway Contractors

The high-speed railway (HSR) sector has been projected to experience exponential growth in the near future, and many HSR projects are being or will be implemented under international contracts. However, the huge international market also gives rise to fierce international competition. This study aims to explore the formation paths of international competitive advantages (ICAs) for HSR contractors. Through a comprehensive literature review, this paper firstly identified the 10 categories of 21 factors at the three covering levels (industry, firm, and project levels) that affect the ICAs of HSR contractors. The factors, categories, hypothetical paths model, and the preliminary questionnaire were refined and verified by the pilot study. Then the proposed paths model was verified through the methods of the partial least squares structural equation modeling and postsurvey interviews. The result validated the 10 significant ICAs paths (named the locomotive model), which could be further classified into two groups: the economic performance-oriented paths and the international reputation oriented paths. Moreover, the result showed the fundamental roles of the industrial triangle engine to the ICAs. This paper contributes to the competitive advantage theory in the field of international HSRs by proposing a verified locomotive model, which is important for the HSR practitioners to recognize in forming paths of ICAs and further developing their competitive strategic plans.

Mechanistic insight into B(C6F5)3 catalyzed imine reduction with PhSiH3 under stoichiometric water conditions.

A DFT and experimental study on the mechanism of B(C6F5)3 catalyzed imine reduction is performed using PhSiH3 as reductant under stoichiometric water conditions. Ingleson’s path B is reconfirmed here. And four novel (C6F5)3B–OH2 induced pathways (paths C2, C3, D2 and D3) entirely different from all the previous mechanisms were determined for the first time. They are all B(C6F5)3 and water/amine catalyzed cycles, in which the nucleophilic water or amine catalyzed addition step between PhSiH3 and the N-silicon amine cation is the rate-determining step of paths C2/D2 and C3/D3 with activation Gibbs free energy barriers of 23.9 and 18.3 kcal mol−1 in chloroform, respectively, while the final desilylation of the N-silicon amine cation depends on an important intermediate, (C6F5)3B–OH−. The competitive behavior of the 5 paths can explain the experimental facts perfectly; if all the reactants and catalysts are added into the system simultaneously, water amount and nucleophiles (excess water and produced/added amine) provide on–off selectivity of the pathways and products. 1 eq. water leads to quick formation of (C6F5)3B–OH−, leading to B-II being turned off, and nucleophiles like excess water and produced/added amine switch on CD-II, leading to production of the amine. B-I′ of Ingleson’s path B is the only mechanism for anhydrous systems, giving N-silicon amine production only; B-I and C-I are competitive paths for systems with no more than 1 eq. water, producing the N-silicon amine and the [PhHC Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]> NHPh]+[(C6F5)3B–OH]− ion pair; and paths C2, C3, D2 and D3 are competitive for systems with 1 eq. water and nucleophiles like excess water or added/produced amine, directly giving amination products.

Deactivation of Industrial Pd/Al2O3 Catalysts by Ethanol: A Spectroscopic Study

AbstractThe chemical processes involved in the decomposition of ethanol over two industrial Pd/Al2O3 catalysts characterized by different Pd dispersions, particles morphology and reducibility of the active metal phase was thoroughly investigated in gas‐phase and in liquid‐phase by transmission FT‐IR and ATR‐IR spectroscopies, respectively. In both cases, two main products were detected, arising from two competitive paths: acetates from ethanol oxidation and carbonyls from acetaldehyde decarbonylation. The regularity of the Pd particles greatly affects the relative proportion of the two products, while the initial Pd oxidation state influences the kinetics of the two processes. Ethanol oxidation to acetates is the kinetically favored reaction path both in gas‐phase and in liquid‐phase. In contrast, the presence of a solvent dampens the decarbonylation process to very low levels, because the solvent competes with ethanol in occupying the available surface sites. Since adsorbed carbonyls are considered as surface poisons of industrial Pd/Al2O3 catalysts in processes involving aliphatic as well as aromatic alcohols, the rationalization of the experimental variables affecting alcohols decomposition can help in establishing working protocols and in designing preparation procedures that minimize the unwanted poisoning effects.

Theoretical investigation on the mechanism and enantioselectivity of organocatalytic asymmetric Povarov reactions of anilines and aldehydes

AbstractThe mechanism is investigated for organocatalytic asymmetric Povarov reaction of anilines and aldehydes using M06‐2X functional. Two molecule of aldehyde condense with aniline and catalyst giving N‐arylimine and enamine. The reaction is stepwise involving [2 + 2] cycloaddition and ring‐opening/cyclization. Four competitive paths exist in step 1 leading to isomers of quaternary nitrogen heterocycle as cycloadduct. Step 2 is sequential with proton transfer and concerted ring‐opening/cyclization in two feasible orders. Each path in step 1 divides into two in step 2 producing isomers of tetrahydroquinoline (THQ) bonded with catalyst as cyclization product. The reactive nucleophilic adduct with two charge centers in step 1 supports the recovery of catalyst and generation of aldehyde assisted by water. THQ alcohol is obtained in the following intramolecular Friedel–Crafts reaction. The enantio‐ and diastereoselectivity are both thermodynamic control with preferred path yielding the most stable isomer with 2S3S or 1R2S3S configuration. The path bias is in line with the reduction degree of energy barrier in solvent compared with gas phase. Our conclusion is verified by Multiwfn analysis and the predicted ee, dr value of THQ scaffold in experiment.

A case study of the mechanism of unfolding and aggregation of a monoclonal antibody in ion exchange chromatography

A mechanistic model for describing unfolding of a monoclonal antibody (mAb) in ion exchange chromatography has been developed. The model reproduced retention behavior characteristic for conformational changes of antibodies upon adsorption, including: multi-peak elution, aggregate formation, and recovery reduction. Two competitive paths in the adsorption mechanism of the unfolded protein were assumed: refolding in the adsorbed phase to the native form followed by its desorption, or direct desorption followed by instantaneous aggregation in the liquid phase. The reduction in recovery of the eluted protein was attributed to spreading of the unfolded protein on the adsorbent surface, which enhanced the binding affinity.The model was formulated based on the analysis of retention behavior of a model mAb that was eluted in pH gradients on a strong cation exchange resin.The pH profile was found to be distorted in the presence of the protein, which was ascribed to dissociation of ionizable groups of the protein in the adsorbed phase. Since the protein retention was strongly pH dependent, that phenomenon was also accounted for in mathematical modeling. A series of independent experiments was designed to evaluate the model parameters that quantified the process thermodynamics and kinetics: the Henry constants of the native, unfolded, spread and aggregated forms of the protein along with underlying kinetic coefficients. The model was efficient in reproducing the retention pattern of the protein and the aggregate content in eluting band profiles. After proper calibration, the model can potentially be used to quantify protein unfolding and elution in other ion exchange systems.

Education for Sustainable Development Review

Education for Sustainable Development Review

GIS Spatial Optimization for Corridor Alignment Using Simulated Annealing

Planning corridors for new facilities such as pipeline or transmission lines through geographical spaces is a topographical constraint optimization problem. The corridor planning problem requires finding an optimal route or a set of alternative paths between two locations. This article presents a simulated-annealing-based (SA) approach applying a variable neighborhood strategy in a continuous space to generate competitive and different alternative paths to solve the corridor planning problem. The variable neighborhood method randomly selects two points from a variable interval of the current solution generated by SA creating pseudo-random paths inside a corridor and finding spatially different alternatives. The proposed approach is evaluated with three practical problems using real topographic data from the Veracruz Basin in Mexico. The experimental results show that this approach obtains efficient and competitive solutions with improvements above 18% over those gotten by the compared method.