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Assessment of cargo handling operation efficiency in the Clarion-Clipperton Zone for standard bulk carriers in the view of significant amplitudes of roll as a limiting criterion

Kacprzak Paweł

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2023

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nr 74 (146)

55--64

EN

Experienced ship roll during loading is the easiest parameter to observe and measure on board of a loaded ship. Therefore, the ship’s significant roll amplitudes should be the key limiting factor in view of the safety and efficiency of cargo handling operations at sea. For the example of three standard bulk carriers, the authors prepared a method of assessment of bulk carrier suitability to perform safe and efficient cargo handling operations in the Clarion-Clipperton Zone in view of significant amplitudes of roll. Via a calculation of the efficiency index for a set of limiting amplitudes of roll during loading simulation, we are able to analyze ship effectiveness. The application of the above-mentioned method can be employed as a useful tool to predict the lowest allowable significant amplitudes of roll when the required efficiency level is specified. Additionally, a calculation is made for the operable days where cargo operations are possible. Investigations show that, according to applied criteria, the effectiveness drops, and not every bulk carrier can perform safe cargo handling operations at sea.

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Effectiveness factors in interim management projects – research concept

Skowron-Mielnik Beata, Sobiecki Grzegorz

Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska

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2020

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z. 149

575--593

EN

Purpose: The aim of studies undertaken in the article is to identify factors that may have an effect on the relationship between the results of interim management projects and increasing their effectiveness. Design/methodology/approach: An empirical-inductive approach – the literature studies and secondary empirical data analyses. Findings: The authors point to the following three key factors: trust, power and knowledge. In the future, the results of the studies presented here will form the foundations to develop an empirical-inductive research program with the aim to verify the significance of the identified factor, the relationships between them and their effect on the effectiveness of the process. It applies not only to commercial organizations, but also to non-profit institutions, political organizations and public utility organizations, such as health care institutions. Practical implications: This article refers to the effectiveness of the implementation process of interim management projects. The effectiveness of the whole process is strongly conditioned by both the competence of the interim manager and the perception of the client. Research results can be used to improve these competences and to improve the effectiveness of IM projects. Originality/value: The pioneering nature of work aimed at filling the existing research gap and answering the research question made the authors opt for an empirical-inductive approach.

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Effectiveness factor of two-dimensional ring-shaped catalyst pellets

Asif M., Ibrahim A. A., Mohammed Y. A., Al-Ghurabi E. H.

Polish Journal of Chemical Technology

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2017

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Vol. 19, nr 3

99--105

EN

The use of hollow catalytic support improves the utilization of the catalytic material because of the absence of the pellet core, and moreover ensures low reactor pressure drop owing to enhanced bed voidage. In this study, the expressions for the efficient computation of the effectiveness factor are derived for a ring-shaped catalyst pellet undergoing first-order irreversible reaction. The methodology consists of using solutions of one-dimensional problems to remove non-homogeneous boundary conditions. The expressions obtained exhibit significantly faster convergence behavior than those reported in literature. The shape parameters, namely, the height-to-diameter ratio and the inner-to-outer radii ratio, significantly affect the catalyst utilization, such that several-fold improvement in the effectiveness factor is achievable.

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Prognozowanie przebiegu rozkładu H2O2 w reaktorze rurowym ze stałym złożem katalazy Terminox Ultra. Cz. I, Ocena oporów dyfuzyjnych

Grubecki I.

Inżynieria i Aparatura Chemiczna

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2017

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Nr 3

74--75

PL

Przeprowadzono ocenę oporów dyfuzyjnych dla procesu rozkładu nadtlenku wodoru przez komercyjną katalazę Terminox Ultra immobilizowaną na powierzchni nieporowatych kulek szklanych. Oceny dokonano w oparciu o wcześniejszą analizę, na podstawie której określono model zewnętrznego transportu masy oraz wartości stałych szybkości reakcji (kR). Pokazano, że dla Q ≥ 15 cm3min-1 najwolniejszym etapem jest dyfuzja wewnątrz biokatalizatora, natomiast dla Q < 15 cm3min-1 transport masy w warstwie ciekłej otaczającej biokatalizator. Przeprowadzona ocena w pełni uzasadnia zastosowanie globalnego współczynnika efektywności jako wielkości wyrażającej wpływ oporów dyfuzyjnych.

EN

Evaluation of diffusive resistance for hydrogen peroxide decomposition by Terminox Ultra catalase immobilized on the surface of nonporous glass beads was carried out. The evaluation was made on basis of earlier analysis in which the external mass transfer model was developed with the intrinsic constant rate for reaction and deactivation. It was shown that the slowest step is the internal diffusive resistance inside the biocatalyst forQ ≥ 15 cm3min-1 and the external diffusive resistance in the liquid layer surrounding the biocatalyst for Q < 15 cm3min-1'. The conducted analysis justifies the introduction of global effectiveness factor expressing the effect of diffusive resistance.