Okka Adiyanto, Pandu Sandi Pratama and Wonsik Choi
This paper aims to examine the friction coefficient and wear rate characteristics of SCM 440 bearing steel used in the cylinder block of a tractor engine with gas lubrication and…
Abstract
Purpose
This paper aims to examine the friction coefficient and wear rate characteristics of SCM 440 bearing steel used in the cylinder block of a tractor engine with gas lubrication and oil lubrication.
Design/methodology/approach
Friction tests were performed using a pin-on-disc tester with loads of 2 to 10 N and sliding velocities of 0.06 to 0.34 m/s. The experiment was done with and without nitrogen, and paraffin oil lubricant was used to prevent wear during process.
Findings
The nondimensional characteristic number from the Stribeck curves indicated that the lubrication regime is hydrodynamic. As the velocity and load increased, the friction coefficient of the SCM 440 increased and greater applied load resulted in a smaller friction coefficient. The range of the friction coefficient was 0.017001 to 0.092904 with paraffin oil lubrication and 0.01614 to 0.4555 with nitrogen lubrication. Nitrogen is effective in reducing the friction coefficient of materials that are in contact and subjected to a load and velocity.
Originality/value
The experiments confirm that nitrogen is effective for reducing the friction coefficient of SCM 440 materials that are in contact with each other and subjected to a load and velocity.
Hyang Mi Choi, Wonsik Sul and Sang Kee Min
This paper seeks to explore such questions as: “What are the impacts of foreign investors and what are the channels through which foreign investors contribute to or detracts from…
Abstract
Purpose
This paper seeks to explore such questions as: “What are the impacts of foreign investors and what are the channels through which foreign investors contribute to or detracts from firm value in Korea?” It aims to discuss how foreign investors and foreign outside directors interact to enhance firm value.
Design/methodology/approach
Using longitudinal data from the KOSPI200 index in Korea during 2004‐2007, the study examined the direct and interaction effect of foreign blockholders and foreign board members. To address the representativeness of foreign investors, the authors verified the mandates of foreign board members though telephone interviews.
Findings
Foreign block shareholders and foreign outside directors respectively provide expertise and independent monitoring over management. Foreign blockholders' management control via board membership is likely to mitigate leverage of value enhancement when foreign outside directors represent private interests of foreign blockholders. The moderating effect is also supported since foreign ownership concentration has an inverted U‐shaped relationship with value enhancement. The paper confirms that board independence reinforces the positive impact of foreign outside directors on firm value.
Research limitations/implications
This study offers a key to understanding corporate governance in that mutual monitoring and a balance among various types of stakeholders are crucial to value enhancement.
Originality/value
The paper provides clues to the extant diverse findings concerning the impact of foreign investors on firm value. It applies an integrated perspective to the empirical analyses of the impact of foreign investors by giving consideration to the agency – foreign outside directors – to implement management control on behalf of foreign blockholders.