41 research outputs found
Modeling and Simulation of Machining-induced Surface Integrity Characteristicsof NiTi Alloy
AbstractNiTi shape memory alloys have gained increased interest in various industries, including biomedical and aerospace applications due to their unique properties such as shape memory effect and superelasticity. Martensitic phase transformation in NiTi significantly affects the surface integrity characteristics. This phase transformation needs to be better understood to control and enhance the shape memory and microstructural properties of NiTi shape memory alloys. This study presents results of combined experimentation and simulation of cutting-induced phase transformation in orthogonal machining of NiTi shape memory alloys. A phenomenological modeling approach was utilized to model machining-induced phase transformation. NiTi shape memory alloys alloy were in austenite phases at room temperature. The transformation during dry machining process from austenite to martensite phases, and the resulting volume fraction was successfully simulated using DEFORM 2-D software by implementing a user-defined subroutine. The developed model is capable of capturing the trend of variationsinvolume fracture and the depth of transformed layer as a function of cutting speed
Psychometric properties and measurement invariance across gender of the Compulsive Online Shopping Scale (COSS) among Iranians.
The present study aimed to investigate the psychometric properties and measurement invariance of the Compulsive Online Shopping Scale (COSS) in an Iranian population. The total sample of 802 participants (257 females; Mean age = 22.27, SD = 2.83) were selected via convenience sampling from Tehran, Iran. Confirmatory Factor Analysis supported the 7-factor structure of the COSS as proposed in the original study. The measurement invariance found in this study suggests that the COSS provides sufficiently unbiased use among males and females. The current findings also support the concurrent validity of the Persian COSS, which exhibited positive and significant associations with loneliness, impulsivity, obsession, internalized symptoms, and Internet use. Furthermore, results confirm the convergent validity of the Persian COSS and showcased acceptable internal consistency for all factors, and the total score. The findings of the present study indicate that compulsive online shopping could be assessed adequately in Iranian samples using the COSS. [Abstract copyright: Crown Copyright © 2023 Published by Elsevier Ltd.
CEO Inside Debt and Earnings Management
This study examines the impact of CEO inside debt on earnings management. Theory predicts that CEOs with higher inside debt holdings adopt less risky corporate policies and choose investment policies that result in less volatile earnings. Under such circumstances, CEOs would face weaker demand for income smoothing. Consistent with these expectations, our results reveal that CEO inside debt is negatively associated with both accrual- and real activities-based earnings management. We also find that firms with higher levels of CEO inside debt are less likely to meet or slightly beat analysts’ earnings forecasts. Furthermore, the capital market response to positive earnings surprises is greater when CEOs hold higher positions of inside debt. Overall, our findings suggest that inside debt counteracts CEOs’ incentives to smooth earnings through earnings management and investors understand the deterrence effect of inside debt on earnings management
An Assessment of Productivity Patterns of Grass-Dominated Rangelands in the Hindu Kush Karakoram Region, Pakistan
Rangelands in the Hindu Kush Karakoram region provide a resource base for nomadic livestock grazing, which is one of the major traditional livelihood practices in the area. The present study assessed the spatiotemporal patterns and trends of rangelands using satellite remote-sensing time-series data. Moderate resolution imaging spectroradiometer (MODIS)-based normalized difference vegetation index (NDVI) data, collected at fortnightly intervals over 12 years (2001–2012), were used as a proxy for the vegetation conditions of the grasslands. The analysis revealed that rangeland productivity increased with increasing elevation up to the sub-alpine zone, which had a higher productivity than the moist temperate zone and humid sub-tropical zone. The high sub-alpine productivity was attributed to seasonal amplitude and the extended length of the growing season in the phenological cycle. In the temporal analysis of productivity, the majority of the area exhibited improvements in vegetation conditions, which were strongest in the humid sub-tropical zones and weakest in the alpine zones. The sub-alpine grasslands were found to be the most productive and heterogeneous habitat; however, the relatively strong negative temporal trend in productivity in this zone indicates ongoing degradation in these rangelands. Thus, special attention is needed for the sustainable management of rangelands in the sub-alpine zones of the Hindu Kush Karakoram region