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Microwave curing (MC) can facilitate rapid concrete repair in cold climates without using conventional accelerated curing technologies which are environmentally unsustainable. Accelerated curing of concrete under MC can contribute to the decarbonisation of the environment and provide economies in construction in several ways such as reducing construction time, energy efficiency, lower cement content, lower carbonation risk and reducing emissions from equipment.

The paper investigates moisture loss and pore properties of six cement-based proprietary concrete repair materials subjected to MC. The impact of MC on these properties is critically important for its successful implementation in practice and current literature lacks this information. Specimens were microwave cured for 40–45 min to surface temperatures between 39.9 and 44.1 °C. The fast-setting repair material was microwave cured for 15 min to 40.7 °C. MC causes a higher water loss which shows the importance of preventing drying during MC and the following 24 h.

Portland cement-based normal density repair mortars, including materials incorporating pfa and polymer latex, benefit from the thermal effect of MC on hydration, resulting in up to 24% reduction in porosity relative to normal curing. Low density and flowing repair materials suffer an increase in porosity up to 16% due to MC. The moisture loss at the end of MC and after 24h is related to the mix water content and porosity, respectively.

The research on the application of MC for rapid repair of concrete is original. The research was funded by the European commission following a very rigorous and competitive review process which ensured its originality. Original data on the parameters of porosity and moisture loss under MC are provided for different generic cementitious repair materials which have not been studied before. Application of MC to concrete construction especially in cold climates will provide environmental, economic and energy benefits.

The article addresses the optimization of safety stock service levels for parts in a repair kit. The work was undertaken to assist a public transit entity that stores thousands of parts used to repair equipment acquired over many decades. Demand is intermittent, procurement lead times are long, and the total inventory investment is significant.

Demand exists for repair kits, and a repair cannot start until all required parts are available. The cost model includes holding cost to carry the part being modeled as well as shortage cost that consists of the holding cost to carry all other repair kit parts for the duration of the part’s lead time. The model combines deterministic and stochastic approaches by assuming a fixed ordering cycle with Poisson demand.

The results show that optimal service levels vary as a function of repair demand rate, part lead time, and cost of the part as a percentage of the total part cost for the repair kit. Optimal service levels are higher for inexpensive parts and lower for expensive parts, although the precise levels are impacted by repair demand and part lead time.

The proposed model can impact society by improving the operational performance and efficiency of public transit systems, by ensuring that home repair technicians will be prepared for repair tasks, and by reducing the environmental impact of electronic waste consistent with the right-to-repair movement.

The optimization model is unique because (1) it quantifies shortage cost as the cost of unnecessary holding other parts in the repair kit during the shortage time, and (2) it determines a unique service level for each part in a repair kit bases on its lead time, its unit cost, and the total cost of all parts in the repair kit. Results will be counter-intuitive for many inventory managers who would assume that more critical parts should have higher service levels.

In this study, we employed a geometric process approach to resolve gearbox maintenance problems. The approach is realistic and direct in modelling the characteristics of a deteriorating system such as a gearbox since a decreasing geometric process can model a gearbox’s successive operating times and an increasing geometric process can model the corresponding consecutive repair times. First, two test statistics were used to check whether the process was geometric or not. Next, model parameters of the geometric process were estimated using the simple linear regression techniques. Finally, the optimal replacement policy based on minimising the long‐run average cost per day was determined for each type of gearbox.

Defines the significant role of the repair facility in customer satisfaction. Defines elements of the repair cost and discusses alternative repair strategies. Illustrates the relationship between repair strategies and total cost of repair and determines the strategy that provides the highest repair quality at a minimum total cost. Provides guidelines for implementing the optimal strategy.

When the system fails, the decision to repair or replace a failed unit may depend on the estimated repair cost. Such an idea is called repair limit replacement policy. The repair limit is a limit on the amount of money which can be spent on the repair of a system. The repair limits thus provide an economic replacement policy. Examines optimal repair‐cost limits for a Weibull‐distributed time to failure and an exponentially distributed repair cost. Derives bounds for the optimal repair cost limit that minimizes the average cost per unit time for repairs and replacement. With those bounds, develops a simple algorithm to obtain the optimal repair‐cost limit. Gives numerical examples to illustrate the algorithm.

In this paper, we consider a repair‐time limit replacement problem with imperfect repair and develop a graphical method to determine the optimal repair‐time limit which minimizes the expected total discounted cost over an infinite time horizon. The method proposed can be applied to an estimation problem of the optimal repair‐time limit from the empirical repair‐time data. Then, the modified scaled total time on test transform of the underlying repair‐time distribution function is used. Numerical examples are devoted to examine asymptotic properties of the nonparametric estimator for the optimal repair‐time limit.

THAT spar repairs were indeed needed, and not only for repairing damage caused by bullets, shells and “flak”, is evidenced by the fact that on one occasion a Hurricane had the bottom boom of the front spar severed when it flew into a balloon cable. Fortunately, the cable broke and the pilot succeeded in flying the aero‐plane back to his station. The wing was satisfactorily repaired at Hawker's Homewood works; some idea of the extent of the damage will be gained from FIG. 11.

The purpose of this work is to describe the effects of the length of cracks and the patch size on the stress intensity factors in a bonded composite repair structure containing multiple site damage.

Finite element method was applied to simulate a bonded repair of a cracked aluminum plate with multiple site damage. A two‐dimensional three‐layer technique was utilized to model damage in a typical aluminum plate with collinear twin cracks.

This research has found that the stress intensity factors of collinear twin cracks can be reduced significantly through bonded composite repair, and their values strongly depend on the relative position of the cracks. Moreover, the composite patch should be 1.5 to two times longer than the crack length and the patch thickness should be 30‐40 percent of the plate thickness for the best repair performance.

Patch debonding can significantly reduce the repair efficiency and should be avoided if possible.

It is seen that, instead of the three‐dimensional finite element model, which is computationally intense, the two‐dimensional three‐layer finite element model has an adequate accuracy to obtain stress intensity factors in a bonded composite repair structure with multiple site damage.

This chapter examines how libraries can help create socially and ecologically compassionate culture by hosting repair events. The introduction provides a general overview of repair events, as well as how they fit into the mission of public libraries and support sustainability goals. This chapter explores the impacts of repair events through the lens of the five conditions of collective success, doughnut economics, the right-to-repair movement, education, cultural practices, accessibility, and social infrastructure. The second part of the chapter provides a case study of Wellfleet Public Library on Cape Cod, Massachusetts, a library that has successfully implemented repair events. The final section offers an overview and step-by-step guide of how libraries can implement repair programs.

In 2015, Malaysia’s investment vehicle, 1Malaysia Development Berhad (1MDB), came under international scrutiny after it amassed a debt of US$11 billion (10.3 billion) (Wright & Clark, 2015), which it had difficulty repaying. More disturbingly, investigators found that US$700 million (658 million) was transferred into the personal bank account of Malaysia’s prime minister, Najib Razak, founder and chairman of 1MDB’s advisory board (Wright & Clark, 2015). Najib was also accused of embezzling state money (Reuters, 2015) and damaging the image of the country (“Najib tried to bribe me”, 2015). This chapter aims to examine the strategies used by the Malaysian prime minister to repair his image in the 1MDB scandal, the effectiveness of these strategies, and how these impacted Malaysia’s public diplomacy efforts in restoring the country’s image and reputation. Findings showed that the prime minister denied wrongdoing, and simultaneously bolstered his position and promised to turn 1MDB around. In contrast to the current explication of Benoit and Pang’s (2008) image repair strategies, Najib’s way of attacking the accusers sheds light into how image repair strategies may be operationalized in the Asian context. A new image repair strategy – diversion – is proposed to be added to the existing framework.