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Article
Publication date: 18 October 2021

Miloš Stanković, Nenad Kolarević, Nikola Davidovic and Marko Miloš

The purpose of this paper is to improve the lubrication and remove as much as possible of the heat generated in the bearing assembly, embedded in the jet engine.

Abstract

Purpose

The purpose of this paper is to improve the lubrication and remove as much as possible of the heat generated in the bearing assembly, embedded in the jet engine.

Design/methodology/approach

To determine the necessary values of the air pressure and oil amount, an experimental approach is used. For that purpose, a custom made test rig is developed.

Findings

Less amount of oil makes better lubrication conditions, reflected in the smaller temperature of the bearings. Concerning the air pressure, too high and too low air pressure deteriorates the lubrication parameters. An optimum value should be determined experimentally. The influence of oil amount is remarkably bigger than the influence of air pressure.

Originality/value

This experimental investigation provides an easy and fast way to improve the high-speed bearings lubrication parameters.

Details

Industrial Lubrication and Tribology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0036-8792

Keywords

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Book part
Publication date: 28 December 2016

Bhaskar Bagchi, Dhrubaranjan Dandapat and Susmita Chatterjee

Abstract

Details

Dynamic Linkages and Volatility Spillover
Type: Book
ISBN: 978-1-78635-554-6

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Book part
Publication date: 25 March 2010

Helen Xu

This study presents evidence of a statistically significant negative correlation between crude oil and equities over the past 20 years. Including proper proportions of…

Abstract

This study presents evidence of a statistically significant negative correlation between crude oil and equities over the past 20 years. Including proper proportions of negatively correlated assets in a diversified portfolio can improve the ratio of reward relative to risk, and therefore, adding crude oil with equities into a diversified portfolio can provide superior portfolio performance, compared with equities alone. Because crude oil prices held stable for nearly a century before the oil crisis of 1973, and oil derivatives did not begin trading actively on public markets until the 1980s, the diversification value of oil is a relatively new phenomenon. Also contributing to the phenomenon, the majority of oil reserves and the majority of crude oil production capacity worldwide are held by entities that are not traded in public equity markets, and therefore, the diversification benefits of oil cannot be fully realized by holding a portion of the global market portfolio of equities.

Details

Research in Finance
Type: Book
ISBN: 978-1-84950-726-4

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Book part
Publication date: 12 February 2021

Munirah Khamarudin, Norkhazzaina Salahuddin and Normalisa Md Isa

The Malaysian oil palm has seen steady progress. Started in Malaysia as an ornamental plant, it has turned into a huge industry. Oil palm production has yielded unlimited…

Abstract

The Malaysian oil palm has seen steady progress. Started in Malaysia as an ornamental plant, it has turned into a huge industry. Oil palm production has yielded unlimited economic profits and is currently an emerging Malaysian economic sector. Malaysia currently accounts for an overwhelming contribution to the production and export of palm oil worldwide, which is 39% and 44%, respectively. From around 4.49 million hectares of land, a massive 17.73 million tons of palm oil and 2.13 tons of palm kernel oil were produced. It has been widely use as food products, cosmetics, livestock feed, as well as in bioenergy industry. This is in line with the fast-growing global demand for the palm oil products. Nevertheless, it is currently experiencing a period of slow or less growth in terms of contributing naturally to gross national productivity. Issues such as extreme weather, aging trees, and plant diseases are most prominent among the natural factors that are hindering the growth of the industry. The global pandemic of COVID-19 is also contributing to the current slow growth of palm oil sector. Malaysia has a crucial role to play in meeting the growing global need for oils and fats, as Malaysia is one of the palm oil and palm oil products' major producers and exporting countries.

Details

Modeling Economic Growth in Contemporary Malaysia
Type: Book
ISBN: 978-1-80043-806-4

Keywords

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Book part
Publication date: 4 March 2008

T.J. O’Neill, J. Penm and R.D. Terrell

The primary aim of this chapter is to examine whether the recent increase in world oil prices has affected inflation expectations and stock market returns in major OECD…

Abstract

The primary aim of this chapter is to examine whether the recent increase in world oil prices has affected inflation expectations and stock market returns in major OECD countries. The key findings are as follows. First, we found no evidence to support the presence of a long term relationship between oil prices and inflation expectations – measured by the difference between yields of inflation indexed and non-inflation indexed government bonds – over the sample between early 2003 and late 2006. Second, higher oil prices are found to lead to expectations of higher inflation. This evidence is stronger over the period where oil prices had been higher and signs of capacity constraints in the economy were emerging. Third, the impact of higher oil prices on stock market returns differs among countries. While higher oil prices are found to adversely affect stock market returns in the United States, the United Kingdom and France, the effects are positive in Canada and Australia as these countries are significant exporters of energy resources.

Details

Research in Finance
Type: Book
ISBN: 978-1-84950-549-9

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Article
Publication date: 1 March 2021

Viju Subramoniapillai and G. Thilagavathi

The most widely recycled plastic in the world is recycled polyethylene terephthalate (rPET). To minimize the environmental related issues associated with synthetic fibers…

Abstract

Purpose

The most widely recycled plastic in the world is recycled polyethylene terephthalate (rPET). To minimize the environmental related issues associated with synthetic fibers, several researchers have explored the potential use of recycled polyester fibers in developing various technical textile products. This study aims to develop needle-punched nonwoven fabrics from recycled polyester fibers and investigate its suitability in oil spill cleanup process.

Design/methodology/approach

According to Box and Behnken factorial design, 15 different needle-punched nonwoven fabrics from recycled polyester fibers were prepared by changing the parameters, namely, needle punch density, needle penetration depth and fabric areal weight. Several featured parameters such as oil sorption, oil retention, oil sorption kinetics, wettability and reusability performance were systematically elucidated.

Findings

The maximum oil sorption of recycled nonwoven polyester is found to be 24.85 g/g and 20.58 g/g for crude oil and vegetable oil, respectively. The oil retention is about 93%–96% in case of crude oil, whereas 87%–91% in case of vegetable oil. Recycled polyester nonwoven possesses good hydrophobic–oleophilic properties with static contact angle of 138° against water, whereas 0° against crude oil and vegetable oil. The reusability test results indicate that recycled polyester nonwoven fabric can be used several times because of its reusability features.

Originality/value

There is no detailed study on the oil sorption features of needle-punched nonwoven fabrics developed from recycled polyester fibers. This study is expected to help in developing fabrics for oil spill cleanups.

Details

Research Journal of Textile and Apparel, vol. 25 no. 2
Type: Research Article
ISSN: 1560-6074

Keywords

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Article
Publication date: 17 February 2021

Liangwei Qiu, Xiaoyang Chen and Fakai Dong

This paper aims to experimentally investigate the film-forming capability of base oils containing poly-methacrylate (PMA) and poly-isobutene (PIB), in a point contact…

Abstract

Purpose

This paper aims to experimentally investigate the film-forming capability of base oils containing poly-methacrylate (PMA) and poly-isobutene (PIB), in a point contact under pure rolling.

Design/methodology/approach

By using the relative light intensity method, the film thickness is calculated from the interferometer images which are captured by multiple-contact optical elastohydrodynamic lubricated test rig.

Findings

The test results reveal that polymers, both PMA and PIB, have a significant contribution to the film-forming capability of base oils and the film thickness increases with concentration. The forming-film capabilities for PMA and PIB in base oils are similar at low concentration, while PIB gives a higher film thickness than PMA at high concentration. Shear-thinning phenomenon are observed in all polymer-based oils.

Originality/value

The polymer usually as an additive is added into the low viscosity base oils to improve the properties of lubricant oil. This paper reports the lubricated properties of PMA and PIB with different concentrations in base oils and to evaluate their functional mechanism in a point contact.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0263/

Details

Industrial Lubrication and Tribology, vol. 73 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 6 October 2021

Shailesh Rastogi, Adesh Doifode, Jagjeevan Kanoujiya and Satyendra Pratap Singh

Crude oil, gold and interest rates are some of the key indicators of the health of domestic as well as global economy. The purpose of the study is to find the shock…

Abstract

Purpose

Crude oil, gold and interest rates are some of the key indicators of the health of domestic as well as global economy. The purpose of the study is to find the shock volatility and price volatility effects of gold and crude oil market on interest rates in India.

Design/methodology/approach

This study finds the mutual and directional association of the volatility of gold, crude oil and interest rates in India. The bi-variate GARCH models (Diagonal VEC GARCH and BEKK GARCH) are applied on the sample data of gold price, crude oil price and yield (interest rate) gathered from November 30, 2015 to November 16, 2020 (weekly basis) to investigate the volatility association including the volatility spillover effect in the three markets.

Findings

The main findings of the study focus on having a long-term conditional correlation between gold and interest rates, but there is no evidence of volatility spillover from gold and crude oil on the interest rates. The findings of the study are of great importance especially to the policymakers, as they state that the fluctuations in prices of gold and crude oil do not adversely impact the interest rates in India. Therefore, the fluctuations in prices of gold and crude may generally impact the economy, but it has nothing to do with interest rate in particular. This implies that domestic and foreign investments in the country will not be affected by gold and crude oil that are largely driven by interest rates in the country.

Practical implications

Gold and crude oil are two very important commodities that have their importance not only for domestic affairs but also for international business. They veritably influence the economy including forex exchange for any nation. In addition to this, the researchers believe the findings will provide insights to policymakers, stakeholders and investors.

Originality/value

Gold and crude oil undoubtedly influence the exchange rates but their impact on the interest rates in an economy is not definite and remains ambiguous owing to the mixed findings of the studies. The lack of studies related to the impact of gold and crude oil on the interest rates, despite them being essentials for the health of any economy is the main motivation of this study. This study is novel as it investigates the volatility impact of crude oil and gold on interest rates and contributes to the existing literature with its findings.

Details

South Asian Journal of Business Studies, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2398-628X

Keywords

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Article
Publication date: 18 September 2020

Fuying Zhang and Yuanhao Zhang

The purpose of this paper is to study the pumping efficiency of oil seals with different surface textures at different speeds, and the influence of the rotation direction…

Abstract

Purpose

The purpose of this paper is to study the pumping efficiency of oil seals with different surface textures at different speeds, and the influence of the rotation direction of triangular texture on the sealing performance was further analyzed.

Design/methodology/approach

Based on the theory of elastohydrodynamic lubrication and the pumping mechanism of rotary shaft seals, establishing a numerical model of mixed lubrication in oil seal sealing area. The model is coupled with the lip surface texture parameters and the two-dimensional average Reynolds equation considering the surface roughness.

Findings

The results show that the application of lip surface texture technology has obvious influence on the oil film thickness, friction torque and pumping rate of oil seal. The triangular texture has the most significant effect on the increase of pump suction rate. When the rotation direction of triangular texture is 315 degrees, the pumping rate of oil seal is the largest compared with the other seven directions.

Originality/value

The model has a comprehensive theoretical guidance for the design of new oil seal products, which provides a certain basis for the application of surface texture technology in the field of sealing in the future.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2020-0198/

Details

Industrial Lubrication and Tribology, vol. 73 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

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Expert briefing
Publication date: 16 March 2020

Oil market dynamics.

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