Sulfur-bearing species in Sagittarius B2 (Main)

The search for interstellar molecules and the effect of physical and chemical properties of the interstellar medium (ISM) on the abundance of molecules lie at the heart of Astrochemistry. One essential motivation is to understand how the molecules can be found and the physical properties of the ISM can be affected and traced by the chemistry of the high-mass star-forming region. While the number of species detected in the interstellar medium is increasing, we require an understanding of the chemistry inside the interstellar medium. In high-mass star-forming regions, the density and temperature of molecules are high, leading to more complex molecules such as methanol, ethanol, Nitrogen-bearing molecules, and Sulfur-bearing molecules. In particular, Sagittarius B2 (Sgr B2) is the most active high mass star-forming region in our Galaxy. Moreover, Sgr B2 is embedded in the Center Molecular Zone (CMZ) region, which leads to Sgr B2 being an excellent target for studying the production of complex molecules under extreme physical conditions (high densities, strong radiation field, high cosmic-ray flux) has long been a favorite region to search for new molecules. In this research, we take advantage of the high angular resolution and high sensitivity of the Atacama Large Millimeter/submillimeter Array (ALMA). In astonishing detail, the observed ALMA data allow us to examine the spatial distribution and structure of molecules in the massive star-forming regions Sgr B2 (Main). I concentrate on sulfur-bearing molecules and derive the physical and chemical properties of the molecules in Sgr B2(Main). The second part of the thesis analyzes their physical evolution from the cold pre-stellar phase to the warm-up phase. Using the astrochemical code Saptarsy, we simulate the chemical evolution of selected sulfur-bearing molecules in 106 years and analyze the impacts of physical conditions of the molecular cloud. We can constrain the physical parameter of the cloud, such as the cosmic rays, the density distribution of the molecular cloud, the thermal evolution of the cloud, and the minor impacts of the molecules’ abundance: the binding energy of species to water ice surfaces, which is the intrinsic parameter of the molecules and impact the gas-grain chemical models. In addition, among the physical parameters of the cloud that we have constrained, we found that cosmic rays ionization is essential, which significantly influences the cloud chemistry producing the ions H+, H3+, H2+, and He+. These ions take part in the formation and destruction processes of COMs. We ran the astrochemical models and investigated the dependence of the abundances on the cosmic-ray ionization rate inside the molecules cloud. We compared the astrochemical model results to the abundance of molecules derived from the observations of the hot cores. Our results showed that cosmic-ray ionization rates of 1.3 10^{−16} s^{-1} match the observed abundance of Sulfur-bearing molecules in Sgr B2(Main)

Entrepreneurial orientation and social ties in transitional economies

Recent research suggests that entrepreneurial orientation (EO) has a more complex effect on performance (i.e. non-linear instead of linear) than previously considered. We extend this view by examining the non-linear effect of each individual dimension of EO (i.e. innovativeness, proactiveness, and risk-taking) on firm performance in the context of a transitional, collectivist economy. Drawing upon social capital theory, we also examine under which social capital conditions (i.e., business and political ties) each dimension of EO is most effective. Using survey data from 137 firms in Vietnam Top 500 Companies, this study shows that innovativeness and proactiveness have inverted U-shaped relationships with firm performance, while the effect of risk-taking on firm performance is also non-linear but in the form of increasing returns. Findings also show that social capital from business ties differentially moderates the effects of EO dimensions on performance. Similarly, social capital from political ties has different moderating effects on the innovativeness-performance and proactivenessperformance linkages. The findings urge managers of firms operating in transitional economies to take the levels of social capital from business ties and political ties into consideration when making their decision on which entrepreneurial strategy to pursue

Key determinants of relationship value gap: a conceptual framework

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Value synergy and value asymmetry in relationship marketing programs

Prior research advocates a positive, linear association between relationship investments and relationship performance. Our study challenges this conventional wisdom and advances the extant literature by investigating the potential curvilinear effects of suppliers' different relationship marketing programs (i.e., social, financial, and structural) on dyadic perceptions of relationship value. From an analysis of 113 buyer-supplier dyads, we found that social programs enhance relationship value synergy, but their effect on relationship value asymmetry between suppliers and buyers follows a U-shaped curve. On the other hand, we observe a positive and increasing returns-to-scale effect of financial programs on relationship value synergy and its inverted U-shaped association with supplier's relationship value asymmetry. Interestingly, structural programs increase relationship value synergy and have a stronger effect on increasing relationship value for the supplier than for the buyer. In addition, we find that structural programs are more effective in creating value in long-term relationships than in short-term relationships; therefore, as the relationship with a buying firm ages, managers should consider investing more in structural programs to develop their relationship. However, in long-term relationships, managers should avoid investing too much in financial programs because financial programs are less effective in increasing creation of relationship value as a relationship ages

The dark side of formal and informal governance

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Outcome versus process value in service delivery

Purpose: This study is embedded in social exchange and transaction cost theories. The objective is twofold: First, to compare the relative importance of process value and outcome value in building affective and cognitive relationship strength; and second, to compare the relative effects of each type of relationship strength on attitudinal and behavioral loyalty. Design/methodology/approach: This empirical study features a quantitative approach. The sample comprises 167 business-to-business (B2B) customers of a large transportation and logistics company in Vietnam. Findings: Process value and outcome value have different effects on affective relationship strength: The effect of process value is greater than that of outcome value. In addition, cognitive strength has a stronger impact on both attitudinal and behavioral loyalty than affective strength. Research limitations/implications: These insights extend extant literature regarding the process and outcome components of the service assessment. Further studies also should employ a cross-industry, cross-country sample to examine the potential moderating effects of country- or industry-specific factors. These findings show B2B managers how to make appropriate resource allocation and investment decisions to enhance relationship strength and resulting customer loyalty. Originality/value: To clarify the links among customer value, relationship strength and customer loyalty, this study examines the relative importance of rational and non-rational factors (i.e., process value vs. outcome value; affective strength vs. cognitive strength) for relationship performance. Unlike most prior research, this study is set in the B2B context of a developing country

The Improvement Model of Navigational Safety for Inland Waterway Transport

This paper aims at evaluating navigational safety for inland waterway transport (IWT). In doing so, the literature and operational features of IWT were initially reviewed to figure out risk elements (REs) influencing the navigational safety for IWT. After that, a fuzzy Analytic Hierarchical Process (AHP) approach was adopted to estimate the weight for the likelihood and consequence measures of REs. Then, continuous risk matrix (RM) was introduced to identify REs\u27 risk level. Lastly, to test the proposed research model\u27s applicability, IWT operators across Vietnam were empirically surveyed. The empirical findings could be useful for IWT operators in launching managerial policies to boost their navigational safety. Furthermore, the proposed risk evaluation framework may serve as a methodological reference in relevant literature

Governance mechanisms and total relationship value: the interaction effect of information sharing

Purpose: The objectives of this study are to examine how contractual and relational governance mechanisms influence total value created in a buyer-supplier relationship and to investigate how supplier's information sharing and information sharing asymmetry between two exchange parties differentially moderate these associations. Design/methodology/approach: The study is conducted with a sample of 110 buyer-supplier matched dyads in various industries in Vietnam. Findings: This study confirms that contractual governance and relational governance have curvilinear effects on total relationship value. Governance mechanisms have distinct interactions with supplier’s information sharing and information sharing asymmetry to influence total relationship value. Research limitations/implications: Future study could expand the sample to various countries to investigate the role of cultural factors in the effects of contractual and relational governance. Practical implications: The study draws implications for supplying managers about how to govern a relationship with a buying firm with which they are sharing information. It also provides implications about how to use contractual and relational governance to control the effects of supplier’s information sharing, information sharing asymmetry, on total relationship value. Originality/value: The study extends the information sharing literature by looking into the effect of supplier’s information sharing on both parties’ relationship value. It contributes to the governance literature by investigating curvilinear effects of contractual and relational governance on relationship performance