Over the past decades, construction delays have been perceived as a global challenge that hinders the time delivery, budget, and quality of construction projects. It is the most common, expensive, and risky problem associated with both private and public construction projects. Within this context, the aim of this study is to investigate the significant factors that influence delays in construction projects in Hargeisa, using the road and building projects as a baseline. Through a questionnaire survey with 51 critical delay factors that are categorized into seven major groups, data were collected from 51 construction stakeholders selected based on simple random sampling from the different construction companies. Feedback from the respondents was analyzed using Relative Importance Index (RII) for ranking purposes. Results showed that delay in honoring payment progressively, underestimation or overestimation of the project cost, and delay in the approval of major changes in the work scope were ranked as the three major causes of delays in construction projects in Hargeisa. The implications of these results are vital to future projects as they clearly demonstrate how less attention is given to the application of project management tools such as robust cost, scope and risk management in construction projects. As such, construction stakeholders are recommended to make efforts to use the appropriate project management practices needed to manage the 16 identified critical delay factors, when executing future construction projects. Although, the current study focused on Somaliland construction projects, it expands and improves the understanding of delay factors in the global context, and as such can be applied to other countries and future studies.

Following the increasing global awareness of the dangers posed by the present state of climate change, many countries such as Uganda have adapted long-term plans for a transition to decarbonised economies. A major strategy for decarbonisation is to replace fossil fuels with renewable energy (RE) sources as the fundamental energy source. Uganda has substantial RE resources for the provision of energy services and production, yet these resources remain untapped. It is therefore crucial that the use of these abundant resources should be heightened. This paper examines and discusses the potential and current RE utilization and development in Uganda from the perspective of sustainable development. The status of the different RE resources and their application/utilization, including details of existing projects in the country, are carefully explored and discussed. The possible drivers for a huge advancement of RE applications and development in Uganda are also discussed before elucidating the major barriers and challenges faced by the energy sector as regards RE. Measures and policies required to facilitate the utilization of RE in Uganda are proposed. These evidence-based policies could guide the delivery of affordable and sustainable energy solutions for all by 2030 in Uganda.

This paper presents the results of experimental and theoretical/computational micro-wrinkles and buckling on the surfaces of stretchable poly-dimethylsiloxane (PDMS) coated with nano-scale Gold (Au) layers. The wrinkles and buckles are formed by the unloading of pre-stretched PDMS/Au structure after the evaporation of nano-scale Au layers. They are then characterized using atomic force microscopy and scanning electron microscopy. The critical stresses required for wrinkling and buckling are analyzed using analytical models. The possible interfacial cracking that can occur along with film buckling is also studied using finite element simulations of the interfacial crack growth. The implications of the results are discussed for potential applications of micro-wrinkles and micro-buckles in stretchable electronic structures and biomedical devices.

This paper presents the results of an experimental study of the adhesion between bi-material pairs that are relevant to organic light emitting devices, hybrid organic/inorganic light emitting devices, organic bulk heterojunction solar cells, and hybrid organic/inorganic solar cells on flexible substrates. Adhesion between the possible bi-material pairs is measured using force microscopy (AFM) techniques. These include: interfaces that are relevant to organic light emitting devices, hybrid organic/inorganic light emitting devices, bulk heterojunction solar cells, and hybrid combinations of titanium dioxide (TiO₂) and poly(3-hexylthiophene). The results of AFM measurements are incorporated into the Derjaguin-Muller-Toporov model for the determination of adhesion energies. The implications of the results are then discussed for the design of robust organic and hybrid organic/inorganic electronic devices.

This paper presents the results of an experimental study of the effects of surface texture on the optical and light trapping properties of silicon wafers. Surface texture is controlled by anisotropic etching with potassium hydroxide (KOH) and isopropyl alcohol (IPA) solutions. The anisotropic etching of (001) crystalline silicon wafers is shown to result in the formation of {111} pyramidal facets on the surfaces of the wafers. A combination of profilometry, optical microscopy, scanning electron microscopy, and atomic force microscopy is used to study the effects of KOH/IPA etching on the morphology and roughness of the textured surfaces. The results show that IPA concentration has the strongest effect on the surface roughness of (001)-single crystal crystals at temperatures up to 80 °C. Above this value, evidence of temperature-induced cracking was revealed on the silicon substrate. The best volume concentration ratio of KOH:IPA is also found to be 2:4. The implications of the study are discussed for the design of light trapping in silicon solar cells.

For centuries now, building codes have been a vital instrument for minimizing susceptibility to natural hazards. These codes are guides to architects and engineers when designing new buildings or renovating existing buildings in vulnerable areas. However, the productive implementation of building codes demands a good institutional structure and training of construction practitioners including artisan. This implies that the introduction of building codes and its proper administration will not be effective unless there is a strategic plan for its enforcement process. This is because the deficiencies and violations of building codes/regulations could lead to a large number of shortcomings, particularly regarding the minimum requirements for public health, safety, general welfare, building quality and environmental protection. It is thus clear that there is a need to explore the barriers associated with the implementation and enforcement of building codes/regulations in different countries. This paper seeks to provide a better understanding on the major barriers to the enforcement and violation of building codes and regulations from a global perspective by reviewing building codes, exploring how they are enforced and the penalties for non-compliances in different countries. Finally, this paper concludes that some of the building codes and regulations are too complex for construction and building professional, and as such, many countries still struggle to understand the proper enforcement of building codes. Â