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Correct and well-planned maintenance based on modern global methods directly affects efficiency, quality, direct production costs, reliability and profitability. The selection of an optimal policy for maintenance can be a good solution for industrial units. In fact, by managing constraints such as costs, working hours and human workforce causing sudden equipment failure, production and performance can increase.

Therefore, in this research a model was presented to select the best maintenance strategy at Kaghaz Kar Kasra Co of Iran. In this study, it was tried to integrate the two techniques of goal programming and the technique for order of preference by similarity to ideal solution (TOPSIS) to prioritize maintenance strategies. First, all factors affecting maintenance were identified, and based on the Best Worst Method (BWM) the degree of their importance was determined.

After the evaluation, only 14 criteria in the 4 dimensions of cost, added value, safety and feasibility were selected. The highest points were given to the criteria of equipment cost and depreciation, equipment and personnel performance, equipment installation time and technical feasibility, respectively. In the next stage, using the TOPSIS method the item of maintenance strategy was ranked, and the 3 strategies of preventive maintenance (PM), predictive maintenance (PDM) and corrective maintenance (CM) were chosen. Modeling was performed utilizing a goal programming approach to select the optimal maintenance strategy for 13 devices. All the technical specifications, cost limits and the device time were extracted. After the model was finished and solved the best item for each device was specified.

1. Developing a goal programming model and decision-making dashboard. 2. Identifying the criteria and factors affecting the selection of the maintenance strategy for paper production Industry

Historically, man's efforts to resist the effects of corrosion can be traced back several hundred years. Sir Hugh Platt (1552–1611) noted that an ‘oily substance’ prevented iron work rusting. The famous Dr. Angus Smith (1817–1884) patented a technique for coating heated metal pipes with ‘coal oil’ to resist corrosion. We have in the above some of the fundamental requirements of a coating, namely: 1. Surface preparation, aiming to clean the pipe surfaces of corrosion products, moisture and foreign matter. 2. Material having a water‐resistant quality.

Summary A new technology for electropainting fabrications such as car bodies, by reversing the conventional polarity, was introduced into the U.K. market in 1979. It was claimed that the new method greatly increased the resistance to corrosive attack in service of such items, but the implementation of the acid paint system used was recognised as a potential source of failure for customary and proven electropaint tank linings used with the original basic protection primer. It was essential that a newly formulated resin tank lining was provided to meet the needs of major consumers of the new cathodic painting process and this dissertation outlines the method chosen and the constraints and risks which applied. A series of trial formulations were prepared incorporating the theory and practice of polymer technology for a new and novel development which would meet the challenge of a brand new technology. The high financial risk involved in possible failure together with the limited time available for assessment was weighted against the potential of a new market, and both commercial and technical requirements were satisfied by extending the theory of surface coating science into practice, through laboratory evaluation.

Synopsis A brief introduction is given to the theory of cathodic protection. Principles and design procedures are described for both sacrificial anode and impressed current cathodic protection with a comparative assessment of both systems and the anodes used in them.

While monetary autonomy is self-explanatory for cryptocurrencies such as Bitcoin with predetermined supply path, it is of great interest to probe into the monetary structures of Stablecoins. In these supply contracts and expands and capital restrictions apply due to the existence of reserves as the exchange rate arrangement adheres to a price rule.

Ever since the launch of Bitcoin and its offspring, examination of cryptocurrencies' trading activity from the empirical finance viewpoint has received much attention and continues to do so. The particular monetary arrangements found in Stable cryptocurrencies (colloquially referred to as Stablecoins), however, have not been properly (1) classified and (2) studied within an empirical international finance and banking context. This paper provides an empirical framework analogous to Impossible Trinity for exploring monetary arrangements across Stablecoins wherein reserves are held as price stability is targeted.

The study findings of existence of the degree of achievement along the three dimensions of the Impossible Trinity hypothesis, namely monetary independence, exchange rate stability and financial openness for a representative sample able to cover all varieties of Stablecoins, provide fresh empirical insights and arguments to this growing literature with respect to the success of their embedded exchange rate stabilization mechanisms. While the hypothesis can be supported for all cryptocurrencies in question, the trade-off combination among exchange rate stability, capital openness and monetary independence varies with the categorical types of Stablecoins.

If Stable cryptocurrencies, therefore, claim the role of global monetary assets freed from sovereign limits and national boundaries, it is critical to explore whether they adhere to traditional monetary frameworks. It goes without saying that in this work the author does not use a complete catalogue of all the available Stablecoins, rather a complete catalogue of all the possible asset classes of Stablecoins. While there is a significant difficulty in finding Algorithmic Stablecoins and, so far, there is plethora of Stable Token initiatives, a broader sample to further examine these under this paper's empirical framework is suggested. Enrichment of the robustness analysis by constructing additional proxies, possibly building time series for the proposed cmo1 subindex and using additional estimation methods is encouraged.

Stablecoins have been developed aiming to address the issue of excessive price variation in cryptocurrencies such as Bitcoin. Holders of Stablecoins enjoy the combined advantages of using a blockchain-based digital infrastructure in fulfilling the functions of store of value and media of exchange and of using a traditional currency, which merely plays the role of the unit of account (and in some circumstances the trusted reserve to which is convertible to). Understanding the varieties of Stablecoins and quantifying the components for success of their price stabilization may result in designing better Stablecoins.

Blockchain and cryptocurrencies have introduced new challenges to money and banking. Cryptocurrencies, which independently float such as Bitcoin, have gained the interest so far due to price variation that allows for gains. But these should be by far not considered to be a substitute to traditional means of payment. Lately, Stablecoins have increasingly gained attention for that USD Tether/Bitcoin pair (a Stablecoin pegged to the US dollar at parity) has outrun the US dollar/Bitcoin pair as the most traded pair in digital exchanges marking the strong position and high demand for Stablecoins.

This approach uncovers the varieties of Stablecoins with respect to their monetary constraints compared to the rest of the cryptocurrencies, which independently float. In this paper, the author provides a conceptual framework for the analysis of the exchange rate mechanisms conditional on Stablecoin asset classes accompanied with an empirical study from the monetary viewpoint. This is the first work in this attempt. The empirical framework employed is analogous to the traditional theory of international monetary economics referred to as Impossible Trinityz.

The peer review history for this article is available at: https://publons.com/publon/10.1108/JES-06-2020-0279

INTRODUCTION All off‐shore operations are subjected to limited space. These activities, normally carried out in unlimited area when oil/gas is extracted on‐shore, are subject to a small platform area requiring considerable ingenuity for their incorporation. Apart from the well, power‐generating facilities and living accommodation for the crew, space is required on the platform for oil/gas separation, condensate storage, waterflood equipment and transportation equipment.

3. Unsolved problems and future developments The previous sections may indicate that cathodic protection, at least if installed to the best standard practice, will solve all immersed corrosion problems offshore. This would be incorrect. However, the history of those structures in the North Sea with complete records of effective cathodic protection indicates that the existing techniques do largely result in safe structures for long periods.

Of the many unrelated types of microbes that can initiate or stimulate the corrosion of metals, the most important economically are the sulphate‐reducing bacteria. They flourish in the soil, in fresh and salt water (including heating and cooling systems) and in oil storage tanks and associated pipelines; and they have been found in all the continents including Antarctica.

The erosion‐corrosion of metal surfaces in a fluid flow environment is accelerated by four factors:

There are three reasons for installing a deep hole groundbed by which it is meant inserting power impressed anodes at a depth greater than 50 ft. The three reasons are:— 1. To minimise interference problems. 2. To circumvent the problem of high surface soil resistivities. 3. To overcome wayleave difficulties. This account is concerned with 1 above.