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In laser powder bed fusion (L-PBF) additive manufacturing, spatter particles are ejected from the melt pool and can be detrimental to material performance and powder recycling. Quantifying spatter generation with respect to processing conditions is a step toward mitigating spatter and better understanding the phenomenon. This paper reveals process insights of spatter phenomena by automatically annotating spatter particles in high-speed video observations using machine learning.

A high-speed camera was used to observe the L-PBF process while varying laser power, laser scan speed and scan strategy on a constant geometry on an EOSM290 using Ti-6Al-4V powder. Two separate convolutional neural networks were trained to segment and track spatter particles in captured high-speed videos for spatter characterization.

Spatter generation and ejection angle significantly differ between keyhole and conduction mode melting. High laser powers lead to large ejections at the beginning of scan lines. Slow and fast build rates produce more spatter than moderate build rates at constant energy density. Scan strategies with more scan vectors lead to more spatter. The presence of powder significantly increases the amount of spatter generated during the process.

With the ability to automatically annotate a large volume of high-speed video data sets with high accuracy, an experimental design of observed parameter changes reveals quantitively stark changes in spatter morphology that can aid process development to mitigate spatter occurrence and impacts on material performance.

The purpose of this investigation is to look at four organisations to see whether they meet the criteria of learning communities. Two are involved with higher education, one is an army unit, and the fourth is an organisation responsible for aviation safety.

The research was based on qualitative analyses of what made the four organisations learning communities. This comprised interviews with key personnel and responding to a 15‐item questionnaire.

In the Australian example, specialised areas of responsibility were established to facilitate change. In the Indonesian example, a colonial past, a political/cultural divide, a feudalistic approach to modern day problems and a rich tradition presented a challenge to innovation. In the army unit, highly specialised knowledge had to be acquired, adapted and applied. In the aviation safety organisation, technological issues specifying flight operations were the main focus. This organisation was akin to both a learning organisation and an innovative knowledge community, although working within a bureaucratic structure.

One limitation was access to personnel such as CEOs. Another was translating the questionnaire into Indonesian. A third was related to confidentiality, i.e. should participants reveal the identity of their parent organisation, and their own?

The study identified the need to re‐define strategic objectives. Organisations must undertake this task when faced with changing circumstances.

The paper has value because it looks at effective, learning communities and the formal and the informal learning process.

The purpose of this paper is to analyse the signal dependency of the camera-based coaxial monitoring system QMMeltpool 3D (Concept Laser GmbH, Lichtenfels, Germany) for laser powder bed fusion (LPBF) under the variation of process parameters, position, direction and layer thickness to determine the capability of the system. Because such and similar monitoring systems are designed and presented for quality assurance in series production, it is important to present the dominant signal influences and limitations.

Hardware of the commercially available coaxial monitoring QMMeltpool 3D is used to investigate the thermal emission of the interaction zone during LPBF. The raw images of the camera are analysed by means of image processing to bypass the software of QMMeltpool 3D and to gain a high level of signal understanding. Laser power, scan speed, laser spot diameter and powder layer thickness were varied for single-melt tracks to determine the influence of a parameter variation on the measured sensory signals. The effects of the scan direction and position were also analysed in detail. The influence of surface roughness on the detected sensory signals was simulated by a machined substrate plate.

Parameter variations are confirmed to be detectable. Because of strong directional and positional dependencies of the melt-pool monitoring signal a calibration algorithm is necessary. A decreasing signal is detected for increasing layer thickness. Surface roughness is identified as a dominating factor with major influence on the melt-pool monitoring signal exceeding other process flaws.

This work was performed with the hardware of a commercially available QMMeltpool 3D system of an LPBF machine M2 of the company Concept Laser GmbH. The results are relevant for all melt-pool monitoring research activities connected to LPBF, as well as for end users and serial production.

Surface roughness has not yet been revealed as being one of the most important origins for signal deviations in coaxial melt-pool monitoring. To the best of the authors’ knowledge, the direct comparison of influences because of parameters and environment has not been published to this extent. The detection, evaluation and remelting of surface roughness constitute a plausible workflow for closed-loop control in LPBF.

The use of indoor living plants for enhancement of indoor relative humidity and the general environment of a large, modern, open plan office building are studied using a mixed-methods paradigm.

The quantitative element involved designated experimental and control zones within the building, selected using orientation, user density and users’ work roles criteria. For a period of six months, relative humidity was monitored using data loggers at 30 min intervals, and volatile organic compounds were measured using air sampling. Qualitative “perception data” of the building’s users were collected via a structured questionnaire survey among both experimental and control zones.

Study findings include that living plants did not achieve the positive effect on relative humidity predicted by (a-priori) theoretical calculations and that building users’ perceived improvements to indoor relative humidity, temperature and background noise levels were minimal. The strongest perceived improvement was for work environment aesthetics. Findings demonstrate the potential of indoor plants to reduce carbon emissions of the [as] built environment through elimination or reduction of energy use and capital-intensive humidification air-conditioning systems.

The study’s practical value lies in its unique application of (mainly laboratory-derived) existing theory in a real-life work environment.

The purpose of this paper is to analyse the macro‐factors and contextual variables surrounding the recent introduction of compulsory bilingual schooling in Abu Dhabi in the United Arab Emirates, in order to generate informed discussion, and in order for stakeholders to understand the sociocultural, linguistic and pedagogical issues involved.

This paper is an analytic one which examines language‐in‐education in Abu Dhabi through a framework of the operational, situational and outcomes factors involved in bilingual education, as identified by Spolsky et al. and Beardsmore. Insights gained from international empirical research into bilingual education are applied to the Abu Dhabi context, and key questions about the specific model of bilingual education selected are posed for future local research to answer.

The paper concludes that bilingual education is likely to confer linguistic, academic and socioeconomic benefits on future generations of Emirati school leavers. However, the acquisition of biliteracy is likely to be challenging because of the diglossic features of Arabic, as well as the linguistic distance between Arabic and English. Because of the ambiguity of international research findings with regard to the appropriate age to begin second language learning, as well as uncertainty about the merits of simultaneous versus sequential teaching of biliteracy, research must be undertaken in Abu Dhabi schools into the effects of bilingual education under conditions of early Arabic/English immersion.

This paper is timely given the recent announcement of compulsory and universal bilingual state schooling from an early age in Abu Dhabi, and necessary given the dearth of discussion and research on language‐in‐education matters in the Arab world. While the paper is contextualised within the school system of Abu Dhabi, it has resonance for adjacent Gulf States and for the many expatriates from across the Middle East who teach and study in Abu Dhabi's schools.