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This study aims to investigate the acoustic roughness of rails on China’s high-speed railways, with a focus on short-wavelength irregularities (less than 80 cm), which are known to significantly contribute to noise. The goal is to develop a specific acoustic roughness spectrum tailored for China’s high-speed railway system, as no such spectrum currently exists.

A long-term tracking study was conducted on major railway lines in China, monitoring rail roughness throughout the initial operational period and the rails’ service life. Data preprocessing techniques such as peak removal and curvature correction were applied for acoustic adjustments. A spatial-wavelength domain transformation was performed, providing the distribution patterns and statistical characteristics of acoustic roughness on China’s high-speed rails. Based on these analyses, a model for constructing the acoustic roughness spectrum was developed.

The study found that the acoustic roughness of China’s high-speed railway rails follows a χ² distribution with six degrees of freedom. For wavelengths greater than 8 cm, the acoustic roughness spectrum remains below the ISO specified limits. In the wavelength range of 3.2 cm to 6.3 cm, the roughness is comparable to or within the limits specified by ISO 3095:2005 and ISO 3095:2013. However, for wavelengths shorter than 2.5 cm, the roughness exceeds ISO limits.

This research fills the gap in the lack of a specific acoustic roughness spectrum for China’s high-speed railways. By establishing a tailored spectrum based on long-term data analysis, the findings provide valuable insights for noise control and rail maintenance in the context of China’s high-speed rail system.

The purpose of this paper is to report the effects of radiation absorption and buoyancy forces on the boundary layer analysis of Casson nanofluid past a vertical plate in a porous enclosure filled with Al₅₀Cu₅₀ alloy nanoparticles.

The authors reconstructed the controlling equations as a group of nonlinear ODEs and solved analytically using perturbation technique. The vital interest in this analysis is to examine the influence of sundry physical parameters on the common profiles (velocity, temperature and concentration) conferred through the plots. Tabular values are listed to discuss the skin friction factor, heat and mass transfer rates. Dual solutions are observed for Newtonian and non-Newtonian fluid cases.

Acquired results indicate that the Casson fluid plays a major role in controlling heat and mass transfer rates as compared with Newtonian fluid. Also, raise in volume fraction of nanoparticles regulates the thermal fields, discerns the velocity fields. The authors established the comparison of present results with previously published results and they are found in good agreement for limited cases.

Because of the substantial properties of aluminium and its alloys such as, extreme corrosion resistance, exalted electrical and thermal conductivities and ease of fabrication they achieved tremendous applications in transportation especially in space and aircrafts, in the production of electrical transmission lines. In view of these, the current literature is perpetrated to probe the impact of radiation absorption and buoyancy forces on the heat and mass transfer analysis of Casson nanofluid in the presence of Al₅₀Cu₅₀ alloy nanoparticles.

The purpose of this study is to propose a Lean Six Sigma (LSS) roadmap to guide healthcare practitioners in the implementation of LSS along with a customized LSS tool kit for reducing medication errors.

The authors initially critically reviewed several frameworks/roadmaps of Lean, Six Sigma and LSS which have been proposed in healthcare sector from the existing literature. This review has led to an understanding of key characteristics, limitations and reasons behind the development of such frameworks/roadmaps. A conceptual roadmap was developed and then validated by a number of LSS experts and a healthcare practitioner. Based on the previous studies and taking LSS experts’ opinions into account, a revised roadmap for reducing medication is presented.

The roadmap for LSS in reducing medication errors is developed. This roadmap includes three phases: Phase 1 cultural readiness for LSS employment in reducing medication errors; Phase 2 preparation, initialization and implementation; and Phase 3 sustainability.

The roadmap has been tested with only a handful of practitioners of LSS. Moreover, only two case studies have been carried out in a Thai hospital setting which followed the roadmap. In order to improve the validity of research, more case studies need to be executed and more people should be used for testing the roadmap with varied cultures.

This is the first attempt in the development of a LSS roadmap that healthcare practitioners can follow to reduce medication errors using LSS methodology and sustaining LSS in their organizations.