Comprehensive topography characterization of polycrystalline diamond coatings

Abhijeet Gujrati,

Tevis D. B. Jacobs,

Antoine Sanner,

Subarna R. Khanal,

Nicolaie Moldovan,

Hongjun Zeng,

Lars Pastewka

Опубликована Янв. 1, 2021

The surface topography of diamond coatings strongly affects surface properties such as adhesion, friction, wear, and biocompatibility. However, the understanding of multi-scale topography, and its effect on properties, has been hindered by conventional measurement methods, which capture only a single length scale. Here, four different polycrystalline diamond coatings are characterized using transmission electron microscopy to assess the roughness down to the sub-nanometer scale. Then these measurements are combined, using the power spectral density (PSD), with conventional methods (stylus profilometry and atomic force microscopy) to characterize all scales of topography. The results demonstrate the critical importance of measuring topography across all …

New permafrost feature - deep crater in central Yamal (west Siberia, Russia) as a response to local climate fluctuations

Marina О. Leibman,

Alexander I. Kizyakov,

Andrei V. Plekhanov,

Irina D. Streletskaya

Опубликована Янв. 1, 2014

This paper is based on field data obtained during short visits to a newly formed permafrost feature in a form of relatively narrow, deep crater. Excluding impossible and improbable versions of the crater's development, the authors conclude that it originated from warmer ground temperatures and an increase in unfrozen water content, leading to an increase in pressure from gas emissions from permafrost and ground ice. This conclusion is also supported by known processes in the palaeo-geography of Yamal lakes and recent studies of gas-hydrate behavior and subsea processes in gas-bearing provinces.

Tribological performance of surface texturing in mechanical applications—a review

Ping Lu,

Robert J K Wood

Опубликована Янв. 1, 2020

Surface textures have been of great interest within the tribology community with nearly 1500 papers published on this topic in the past two decades. With the pursuit of low emissions and environmental sustainability, the application of surface texturing to mechanical systems to lower friction and control wear is attracting increasing attention. There is no doubt that certain textured surfaces can have a beneficial effect on tribological performance but it is widely agreed that the optimization of textures should be carried out based on specific requirements of applications. The purpose of this review article is to summarize the current state of …

Pan Eurasian experiment (peex) - a research initiative meeting the grand challenges of the changing environment of the northern pan-Eurasian arctic- boreal areas

Hanna К. Lappalainen,

Nina Zaitseva,

Olga Glezer,

Mikhail Arshinov,

Antti Lauri,

Taina Ruuskanen,

Vladimir B. Lapshin,

Tuukka Petäjä,

Joni Kujansuu,

Veli-Matti Kerminen,

Anatoly Shvidenko,

Jaana Bäck,

Timo Vesala,

Gerrit de Leeuw,

Dominick V. Spracklen,

Steve R. Arnold,

Sirkku Juhola,

Heikki Lihavainen,

Yrjö Viisanen,

Natalia Chubarova,

Sergey Chalov,

Nikolay Filatov,

Andrey Skorokhod,

Nikolay Elansky,

Egor Dyukarev,

Igor Esau,

Pertti Hari,

Vladimir Kotlyakov,

Nikolay Kasimov,

Valery Bondur,

Gennady Matvienko,

Alexander Baklanov,

Evgeny Mareev,

Yuliya Troitskaya,

Aijun Ding,

Huadong Guo,

Sergej Zilitinkevich,

Markku Kulmala

Опубликована Янв. 1, 2014

The Pan-Eurasian Experiment (PEEX) is a new multidisciplinary, global change research initiative focusing on understanding biosphere-ocean- cryosphere-climate interactions and feedbacks in Arctic and boreal regions in the Northern Eurasian geographical domain. PEEX operates in an integrative way and it aims at solving the major scientific and society relevant guestions in many scales using tools from natural and social sciences and economics. The research agenda identifies the most urgent large scale research guestions and topics of the landatmosphere-aquatic-anthropogenic systems and interactions and feedbacks between the systems for the next decades. Furthermore PEEX actively develops and designs a coordinated and coherent ground …

Analysis of Financial Statements Based on Financial Ratio and Vertical-Horizontal Method in PT Unilever, Tbk, 2016-2017 Period

Nova Tri Anggraini

Опубликована Янв. 1, 2022

This research aims to horizontally and vertically determine the financial performance of PT Unilever, Tbk, especially by observing the development of assets and financial statements through the calculation of financial ratios. Based on the research results, it can be observed that based on the analysis of the ratio of Liquidity, Profitability and Leverage tend to fluctuate. The liquidity ratio has increased, Profitability ratio has increased in GPM and NPM but decreased in Cash Ratio, ROA, and ROE. The Leverage Ratio has decreased; thus, the financial performance of PT Unilever, Tbk has not been fully optimal. Based on the horizontal analysis, …

Contribution of Inventory Accounting Systems in Improving Inventory Internal Control

Ade Onny Siagian

Опубликована Янв. 1, 2020

The purpose of this study was to determine the Role of Inventory Accounting Systems in Improving the Inventory Internal Control Structure at Putri Mayasari Cilandak. The research method used in this study is a qualitative research method with a case study approach and the data collected consists of primary and secondary data. Then Primary Data is collected through interviews, observations, and documentation, while Secondary Data is collected through library research to determine the role of the inventory accounting system in improving the structure of internal inventory control. The results of the study found that the role of the inventory accounting …

The Effect of Investment, Free Cash Flow, Earnings Management, and Interest Coverage Ratio on Financial Distress

Meryana,

Erna Setiany

Опубликована Янв. 1, 2021

The purpose of this research is to test investments, free cash flow, earnings management, and interest coverage ratio are affecting the risk of financial distress in healthy enterprises.. Healthy companies can be seen from how large the value of working capital, retained earnings, income before tax, market value and sales implemented in the measurement of the financial difficulties model with the Altman Z-score method. Collection of data by purposive sampling and number of samples as many as 33 companies in the category of healthy companies. The results show that free cash flows and interest coverage ratio significant effect on the …

Material ratio curve of 3D surface topography of additively manufactured parts: an attempt to characterise open surface pores

S Lou,

Z Zhu,

W Zeng,

C Majewski,

P J Scott,

X Jiang

Опубликована Сен. 1, 2021

Surface topography of additively manufactured components often contains 3D features, e.g. particles, open surface pores. X-ray computed topography can capture these features, allowing measurement data to be used for 3D surface texture characterisation. On the basis of the newly developed 3D surface texture parameters, this paper investigates material ratio curves of the surfaces produced by additive manufacturing processes, i.e. selective laser melting and high speed sintering. The material ratio curves of these surfaces vary in their shapes, depending on the specific process and associated process parameters, as well as surface orientations. Re-entrant topography features can result in recess shapes on …

3D tooth microwear texture analysis in fishes as a test of dietary hypotheses of durophagy

Mark A Purnell,

Laurent P G Darras

Опубликована Янв. 1, 2015

An understanding of how extinct animals functioned underpins our understanding of past evolutionary events, including adaptive radiations, and the role of functional innovation and adaptation as drivers of both micro- and macroevolution. Yet analysis of function in extinct animals is fraught with difficulty. Hypotheses that interpret molariform teeth in fishes as evidence of durophagous (shell-crushing) diets provide a good example of the particular problems inherent in the methods of functional morphology. This is because the assumed close coupling of form and function upon which the approach is based is weakened by, among other things, behavioural flexibility and the absence of …

Природно-ресурсные отрасли Дальнего Востока: новые факторы развития

Наталья Евгеньевна Антонова,

Наталья Валентиновна Ломакина

Опубликована Янв. 1, 2018

Целью данной статьи выступает исследование проявления институциональных новаций, реализуемых в настоящее время в рамках новой модели развития экономики Дальнего Востока, в природно-ресурсных отраслях региона, а также направлений российско-китайского сотрудничества, которые влияют на текущее состояние и перспективы развития этих отраслей. Исследование базируется на теориях ресурсной экономики, пространственной экономики, включающей региональную экономику. Основная научная проблема, затронутая в статье, находится на стыке исследований, связанных с оценкой эффективности государственной политики, системных эффектов ресурсных проектов и их локализации на региональном уровне в условиях влияния внешнеэкономических факторов. Новизна исследования состоит в теоретической постановке и практической реализации исследовательской задачи совместного рассмотрения институциональных новаций и внешнего фактора, определяющих …