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This paper investigates the degree of competitiveness within the Turkish cement industry, employing firm-level quarterly data spanning from 2008 to 2016.

To assess the level and trajectory of competition among Turkish cement firms, we employ the Boone indicator (β) as formulated by Boone (2008). This indicator, rooted in the concept of relative profit differences (RPD), serves as a robust metric for gauging competitive dynamics. According to the ß indicator, firms exhibiting higher relative efficiency are expected to secure greater profits and market shares in a fiercely competitive market. Additionally, we utilize concentration indices for the purpose of revealing comparable findings.

Empirical findings reveal that an enhancement in firms' efficiency corresponds to a proportionally modest increase in either market share or profits, implying a lower degree of competition within the Turkish cement industry. Although the specific magnitudes of ß estimates exhibit temporal fluctuations, we may conclude that the Turkish cement industry does not conform to the ideals of perfect competition. The concentration indices calculated on the sample also support this result.

This research is limited to the Turkish cement companies over the period 2008–2016.

The studies measuring the level of competition in the Turkish cement sector are generally based on concentration ratios. In this study, we assess the competition level by using a different methodology based on parametric procedures.

This study aims to evaluate and compare by 100 hours engine bench tests the tribological performances of two types of lubrication oils, which were sulfur-based, boron succinimide-containing antiwear package (NP-3) oil and conventional zinc dialkyldithiophosphate (ZDDP)-containing (R-1) oil.

The tribological performances of the oils were evaluated in three main contexts, including engine tests, physical/chemical changes and surface analysis.

Results showed that NP-3 lubrication oil, which was environment- and catalyst-friendly, can be an alternative lubrication oil with its tribological performance due to similar antiwear characteristics with the ZDDP.

Attempts to develop catalysis- and environment-friendly antiwear additive packages have not presented popular or commonly used ZDDP-free products for the vehicle industry. This study presents tribological characterization of a newly developed ZDDP-free lubricating oil by engine bench tests.

Despite developments in the fields of technology and health, some people may still have congenital or acquired disabilities. In our world, where one in every seven consumers is disabled, these consumers also have the right to utilize the services offered to them in the best way as the other six. With the developed technology and innovations, it has become easier and more inexpensive for disabled consumers to access products and services. The number of disabled consumers is also increasing day by day in the tourism sector. However, the designs of touristic products are not suitable for every type of disability. The concept in disabled tourism that is known as “Quiet Tourism” in the literature represents the group including consumers with hearing and speech loss. This section aims to present consumers with hearing and speech loss who have to continue their lives this way becoming a new market for accommodation firms and what types of difficulties and opportunities may be encountered. It is aimed to show that the existing infrastructure at accommodation firms is not adequate, but there is a considerable potential.

This study aims to investigate the tribological characteristics of a Napier-type second piston ring against a cylinder liner in the presence of graphene nano-additives mixed into 5W40 fully synthetic engine oil.

Wear tests were carried out in the boundary lubrication condition using a reciprocating tribometer, and real engine tests were performed using a single spark ignition Honda GX 270 test engine for a duration of 75 h.

The experimental results of the tribometer tests revealed that the nano-additives formed a layer on the rubbed surfaces of both the piston ring and the cylinder liner. However, this layer was only formed at the top dead center of the cylinder liner during the engine tests. The accumulation of carbon (C) from the graphene was heavily detected on the rubbed surface of piston ring/cylinder liner, mixed with other additive elements such as Ca, Zn, S and P. Overall, the use of graphene nano-additives in engine oil was found to improve the frictional behavior in the boundary and mixed lubrication regimes. Abrasive wear was found to be the main mechanism occurring on the surface of both piston rings and cylinder liners.

Though many researchers have discussed the potential benefits of graphene as a nano-additive in oil to reduce the friction and wear in laboratory tests using tribometers, to date, no actual engine tests have been performed. In this paper, both tribometer and real engine tests were performed on a piston ring and cylinder liner using a fully formulated oil with and without graphene nano-additives in the boundary lubrication condition. It was found that a graphene nano-additive plays an active role in lowering the coefficient of friction and increasing surface protection and lubrication by forming a protective layer on the rubbing surfaces.

The purpose of this technical paper is to investigate the friction and wear behavior of inexpensive and durable cutting tools, developed for wood machining using duplex treatment.

Cr–(WC–Co) coatings were deposited onto carburized low-alloy steel substrate by a reactive magnetron sputtering. The total coating thickness was approximately 2 μm. Unlubricated wear tests have been performed using a disc sample sliding against an alumina ball (Al₂O₃) and a wood (beech) pin.

The paper provides information about the effect of duplex treatment on the surface properties of low-alloy steel against wood and offers practical help for the researchers in coating topic.

Experimental results showed that sliding wear properties of the selected coatings are strongly dependent on the counter-face material. When tested against alumina balls, the wear mechanisms are oxidative wear followed by a combination of adhesive and abrasive wear, while a combination of an oxidative and adhesive wear was the main wear mechanism observed against a wood pin.

Introduction – As a financial instrument, tax has always been one of the policy support instruments that governments apply to solve problems. The issue of the environment, on the other hand, is a notion that has gained more importance over the past years and governments struggle to create solutions to environmental problems on the global scale. Climate change is one of the most important parts of this issue. Especially in our modern day, as a result of natural disasters, forest fires and landslides, climate change has become a field in which serious political measures should be taken. Although it has become necessary to implement tax as a tool to decrease carbon emissions and to open new fields for works with less carbon emission, the expected/desired results about carbon emissions have not been obtained throughout the world.

Purpose – The aim of this chapter is to examine carbon taxes, which are the tax applied against climate change, and to draw attention to the multiple policy approach in the face of global environmental problems.

Methodology – This chapter, in which qualitative research method is adopted, has descriptive elements. In this context, an evaluation has been put forward in the light of the data obtained from various reports and scientific articles.

Findings – Though tax is indeed considered as an effective political tool among the precautions to be taken, one-dimensional approach might bring along a deadlock in the solution of this problem. In order to improve this approach and the perception towards the environment across society, it is necessary to include other factors that can play an important role in this process such as non-governmental organisations. Consequently, in order to solve the environmental problems which have occurred as a result of human activities, it is essential to minimise the destruction caused by these human activities (although it is not possible to restore it completely). Therefore, a multi-dimensional policy instead of a one-dimensional policy, an environmentally conscious society and state, and cooperation of policy actors on a global scale are basic elements which can play an important role in the solution of the problem.

The study is called for to eliminate the noise between the significant macro variables from the perspective of the cause-and-effect approach to indicate why and how the return of solar projects is being affected by these.

The study aims to investigate the spread between unit selling electricity prices of a monthly production of 250 KW solar project installed in Türkiye and USD/TRY.

A relational framework is designed by drawing on the variables determined as crude oil prices, United States (US) 2-year yield, Dollar Index (DXY), USD/TRY, the annual inflation rate of Türkiye, and unit selling electricity prices. Then, a multivariate approach is performed through Matlab to analyse the correlational relationships and structure the curve estimation models.

The observations show that the gradually rising spread between unit selling electricity price and USD/TRY signals the reduction in return-on-investment rate of solar energy projects because of the particular causes of the European energy crisis by the reason of Russia and Ukraine war and escalating risks in DXY and US treasury yields as a result of federal fund rate hikes against inflationary pressures. Solar energy investments are delicate instruments to global oil shocks and higher DXY in controlling Inflation and currency volatility; therefore, resilient policies should solicit the demand because of environmental and economic reasons to reduce the external dependency of Türkiye.