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As an example of structure-efficiency relationship study, this paper aims to evaluate the corrosion inhibition effect of two cationic surfactants, cetyl-trimethyl ammonium chloride (CTAC) and cetyl-dimethyl-hydroxyethyl ammonium chloride (CDHAC), and to discuss the effect of structure on the performance by thermodynamics methods.

The effect of the two cationic surfactants, CTAC and CDHAC, on the corrosion of the mild steel in HCl solution was investigated by using weight loss measurements, and the activation energies of CTAC and CDHAC involved in the corrosion inhibition were calculated and discussed.

The weight loss measurements showed that the corrosion inhibition efficiency of CDHAC was higher than that of CTAC in any case. The effects of the structure on performance were discussed, and the following data are available from the results, all of ΔS are positive, the values of ΔG are both close to −40 kJ·mol-1 and the values of ΔH are 10.960 and 36.996 kJ·mol-1, which indicate that the surfactant molecules are spontaneously adsorbed on the surface of the steel surface, and the adsorption on the steel plate is endothermic chemical adsorption.

The available data show that most organic inhibitors undergo physisorption on the metal surface, while in the presence of non-bonded and p-electrons, the inhibitor molecules may undergo chemisorption. This work showed that the two surfactant molecules are spontaneously adsorbed on the surface of the steel surface, and the adsorption on the steel plate is endothermic chemical adsorption.

The purpose of this paper is to examine the impact of the regulatory-driven market structure on firm pricing behaviour by testing the structure-conduct-performance (S-C-P) hypothesis for both life and non-life insurance markets in Ghana.

Using a panel data on 14 life and 22 non-life insurers from 2007 to 2011, the authors employed the Herfindahl Hirschman Index and concentration ratio as proxies for the S-C-P hypothesis while efficiency scores were estimated using the data envelopment analysis technique to proxy for the efficient structure (ES) hypothesis. The dependent variable, profitability was measured as return on assets while controlling for size, underwriting risk, leverage, GDP growth rate and inflation. The models were estimated using the panel corrected standard errors of Beck and Katz (1995) and random effects estimations.

The results from the empirical estimation provide ample evidence in support for ES hypothesis for both life and non-life insurance markets. While conflicting results was found for SCP hypothesis in the non-life insurance market, it was rejected in the life insurance market. The findings also point to an increasing level of competition in both life and non-life insurance industry in Ghana though they still remain concentrated with the life insurance sector having high levels of efficiency compared to the non-life sector.

The findings of the study will enhance the understanding of firm behaviour in the new markets created to shape regulatory and competition policies of the regulator to promote consumer welfare while ensuring a stable industry to enhance its role in economic development.

This is the first study to test the market power and efficient hypotheses on the insurance industry in Ghana. To the best of the author’s knowledge, this study is the first to examine the determinants of profitability in the non-life insurance market.

The purpose of this paper is is to identify the main determinants of insurance profitability on life and non-life segments to obtain which variables affect in each market of the Ecuadorian insurance sector.

The authors use a large panel data set with financial information from 2001 to 2017 and estimate the determinants through a panel corrected standard errors regression.

The authors found that net premiums, technical reserves, capital ratio and score efficiency are micro-determinants in the life insurance sector, whereas in the non-life sector, the micro-determinants include also claim level and liquidity ratio; moreover, the authors found that HHI is a determinant of profitability only in the life insurance. Among the macro determinants set, the authors found that the interest rate has also a significant impact both in the life and non-life insurance.

The authors analyze a dollarized emerging country, which is the first time in this kind of studies. The authors also include the structure-conduct-performance and relative market power paradigm as well as the ES hypothesis, calculated through the data envelopment analysis, as determinants of insurance profitability. Finally, this is the first research to examine the determinants of profitability in Latin American and Caribbean insurers.

In China, engineering insurance has been questioned as not being beneficial as expected. This paper seeks to further understand how China's engineering insurance industry functions and to provide a macro perspective explanation for engineering insurance's underdevelopment.

Three industrial organization hypotheses were extended to the engineering insurance context: structure conduct performance (SCP), relative market power (RMP) and efficiency structure (ES) hypotheses. This paper employed the Generalized Method of Moments (GMM) and Data Envelopment Analysis (DEA) bootstrap to test the hypotheses using panel data from 2008 to 2017.

The results suggest that the SCP paradigm is validated in China's engineering insurance market, indicating a concentrated market where the welfare of consumers (e.g. owners, contractors and designers) may be eroded. Several factors are identified to have significant impacts on engineering insurers' performance, such as the investment return, percentage of engineering business, the ratio of outstanding claims, the number of large contractors, market rivalry and entry barriers.

Despite the sheer size of China's construction industry and the urgent need to improve risk management, the insurance industry that serves construction firms engineering insurance is underdeveloped. Engineering insurance is yet to be understood from a macro perspective, which may reveal the underlying reasons for engineering insurance's underdevelopment. The industrial organization theories provided a theoretical framework to test the functioning of this specific industry. The disaggregated data (engineering line specific) is employed to ensure effective regulation and policymaking.

This chapter discusses a survey of literature on efficiency, productivity and other issues related to pharmaceutical industry in India and across the globe. Econometric theoretical literature on technical efficiency (TE) as well as econometric theoretical literature on total factor productivity growth (TFPG) are discussed in separate sections. Individual sections discuss studies on the performance of the pharmaceutical industries in the Indian context, studies on the performance of the pharmaceutical industries in the international context, studies on the efficiency of Indian pharmaceutical industry (IPI), studies on the TFPG of the IPI, other studies on IPI and also studies on the performance of the pharmaceutical industries in the international context (other than India). This chapter discusses the existing study highlighting the gaps and presents the connection of the present study with the existing literature in the conclusion section.

This paper explores the issue of efficiency in European banking. It tries to distinguish among the market‐structure and efficient‐structure hypotheses by incorporating into our empirical analysis measures of X‐efficiency and scale‐efficiency. Tests of the four hypotheses (the two market power hypotheses and the two efficient structure hypotheses) were performed by regressing measures of concentration, market share, X‐efficiency and scale efficiency against profits. Our empirical findings seem to suggest that the two efficient structure variables do not help in the explanation of the variability of bank profits and, hence, these results do not provide any support for the two efficient structure hypotheses. Our findings also indicate that big banks are more X‐efficient than small banks. This result seems to suggest that there are cost advantages associated with greater bank size.

The aim of this study is to evaluate the corrosion inhibitory properties of three piperazine derivatives – Ethyl 5-(piperazine-1-yl) benzofuran-2-carboxylate (EPBC), 5-[4–(1-tert-butoxyethenyl) piperazin-1-yl]-1-benzofuran-2-carboxamide (BBPC) and Tert-butyl-4–(2-(ethoxycarbonyl)benzofuran-5-yl)-piperazine-1-carboxylate (TBPC) – on Al surfaces in the presence of hydrochloric acid (HCl). The research uses density functional theory (DFT) and molecular dynamics simulations to explore the effectiveness of these derivatives as corrosion inhibitors and to understand their adsorption behavior at the molecular level.

This study uses a computational approach using DFT at various levels (B3LYP/6–31+G(d,p), B3LYP/6–311+G(d,p), WB97XD/DGDZVP) to calculate essential quantum chemical parameters such as energy gap (ΔE), ionization energy (I), absolute electronegativity (χ), electron affinity (E), dipole moment (µ), absolute softness (s), fraction of electron transferred (ΔN) and absolute hardness (η). The Fukui function and local softness indices are used to assess the sites for electrophilic and nucleophilic attacks on the inhibitors. Molecular dynamics simulations are performed to analyze the adsorption behavior of these derivatives on the Al (110) surface using the adsorption locator method. Theoretical methods like DFT provide quantum chemical parameters, explaining inhibitor reactivity, whereas molecular dynamics simulate adsorption behavior on Al (110), both supporting and correlating with experimental inhibition efficiency trends.

This study demonstrates that all three piperazine derivatives exhibit strong adsorption on the Al surface, with high adsorption energies, good solubility and low toxicity, making them effective corrosion inhibitors in acidic environments. Among the three, TBPC showed superior inhibitory performance, particularly in the presence of HCl, due to its optimal electronic properties and stable adsorption on the Al (1 1 0) surface.

This research contributes to the field by combining DFT calculations and molecular dynamic simulations to evaluate the corrosion inhibition potential of piperazine derivatives comprehensively. This work advances the understanding of the adsorption mechanisms of organic inhibitors on metal surfaces and offers a detailed quantum chemical and adsorption behavior analysis.

This study aims to synthesize two organic heterocyclic compounds, (2E,3E)-6-chloro-2,3-dihydrazinylidene-1-methyl-1,2,3,4-tetrahydroquinoxaline (MR1) and (2E,3E)-2,3-dihydrazinylidene-1-methyl-1,2,3,4-tetrahydroquinoxaline (MR2), characterize them using nuclear magnetic resonance spectroscopy (1H-NMR and 13C-NMR) and evaluate their effectiveness as corrosion inhibitors in an acidic environment (15% HCl).

The synthesized compounds, MR1 and MR2, were tested for their corrosion inhibition properties using potentiodynamic polarization and electrochemical impedance spectroscopy. Post-corrosion, the steel surface was analyzed with scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM) to confirm the adsorption of the compounds. The experimental findings were further supported by density functional theory calculations and molecular dynamics simulations.

The results indicated that both MR1 and MR2 exhibit significant anticorrosive activity in a 15% HCl environment. The analyses performed with SEM, EDX and AFM confirmed the effective adsorption of the inhibitors on the steel surface, forming a protective layer. Theoretical studies provided additional insights into the adsorption mechanisms and stability of the inhibitors.

This work introduces novel organic heterocyclic compounds based on quinoxalinone as effective corrosion inhibitors in acidic environments. The combined experimental and theoretical approach provides a comprehensive understanding of their anticorrosive behavior.

This paper aims to explore organizational structure, efficiency and evolution, and its relationship to bureaucracy. A new mathematical model is utilized to generate theoretically consistent relationships between economic performance and organizational scale and structure, and to develop a taxonomy of organizational structure.

A systems approach is used to model structural evolution and generate consistent, testable hypotheses concerning organizational sustainability and financial performance. This theoretical treatment seeks to reconcile contradictory views of bureaucracy, modeling both positive and negative impacts on performance and behavior. A variant of agency theory is used as an organizing paradigm, based on three competing organizational needs: control, autonomy and ownership of consequences.

Simulations reveal that organizations evolve through five stages of development: from an entry (flat/parallel) stage, through a hybrid or mixed stage, to the massively serial (hierarchical) stage. As firms evolve, the risk/return ratio first falls as employment expands, but later rises as higher levels of hierarchy appear. Eventually, organizational complexity rises sufficiently to produce lower levels of managerial ownership of consequences and professional autonomy, as well as higher levels of control, leading to a collapse of organizational efficiency. A subtle variation of agency theory is revealed: upper-management may maximize organizational depth, increasing salary differences between levels.

This paper uses an internally consistent, deductive framework to elucidate relationships between task complexity, skill level, industry life-cycle and firm age – providing the first known attribute-based metric for organizational complexity. This approach is reminiscent of Perrow’s (1999) non-mathematical treatment of organizational systems complexity.

The study examines the synthesized influences of institutional governance and the scale effects of agricultural credits on the sustainability of microfinance institutions (MFIs) in Sub-Saharan Africa.

Using a sample of 840 MFIs (300 independent and 540 networked), the study applied Generalized Method of Moments (GMM) and Lewbel’s estimator.

Results indicate positive effects of financial structure, efficiency and agricultural credit scale on sustainability, with a non-linear U-shaped relationship between agricultural credit size and microfinance sustainability. Depending on institutional governance quality, a threshold is identified where agricultural credit scale significantly enhances the quality of Portfolio at Risk (lnPAR) in independent MFIs and Returns on Assets (lnROA) in networked MFIs.

Study suggests strengthening governance for transparency and operating within optimal size for enduring sustainable performance. While focused on Sub-Saharan Africa, future research could expand to various economies or introduce additional variables for a comprehensive analysis.

MFIs can achieve sustainability by implementing management guided by better institutional norms, innovative financial transformations better suited to financing agricultural activities and techniques and an organizational structure more aligned with their performance targets.

Broader and more reliable access to financial services, particularly in the agricultural sector, can stimulate production and alleviate poverty.

The study’s originality lies in its contribution to the literature by examining the role of institutional governance in microfinance institution performance and evaluating microfinance in a broader Sub-Saharan African context, proposing threshold limits where agricultural microcredit compromises performance.