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This paper aims to present spot pattern welding (SPW) as a scanning strategy for laser-foil-printing (LFP) additive manufacturing (AM) in place of the previously used continuous pattern welding (CPW) (line-raster scanning). The SPW strategy involves generating a sequence of overlapping spot welds on the metal foil, allowing the laser to form dense and uniform weld beads. This in turn reduces thermal gradients, promotes material consolidation and helps mitigate process-related risks such as thermal cracking, porosity, keyholing and Marangoni effects.

304L stainless steel (SS) feedstock is used to fabricate test specimens using the LFP system. Imaging techniques are used to examine the melt pool dimensions and layer bonding. In addition, the parts are evaluated for residual stresses, mechanical strength and grain size.

Compared to CPW, SPW provides a more reliable heating/cooling relationship that is less dependent on part geometry. The overlapping spot welds distribute heat more evenly, minimizing the risk of elevated temperatures during the AM process. In addition, the resulting dense and uniform weld beads contribute to lower residual stresses in the printed part.

To the best of the authors’ knowledge, this is the first study to thoroughly investigate SPW as a scanning strategy using the LFP process. In general, SPW presents a promising strategy for securing embedded sensors into LFP parts while minimizing residual stresses.

This study aims to improve detection efficiency of fluorescence biosensor or a graphene field-effect transistor biosensor. Graphene field-effect transistor biosensing and fluorescent biosensing were integrated and combined with magnetic nanoparticles to construct a multi-sensor integrated microfluidic biochip for detecting single-stranded DNA. Multi-sensor integrated biochip demonstrated higher detection reliability for a single target and could simultaneously detect different targets.

In this study, the authors integrated graphene field-effect transistor biosensing and fluorescent biosensing, combined with magnetic nanoparticles, to fabricate a multi-sensor integrated microfluidic biochip for the detection of single-stranded deoxyribonucleic acid (DNA). Graphene films synthesized through chemical vapor deposition were transferred onto a glass substrate featuring two indium tin oxide electrodes, thus establishing conductive channels for the graphene field-effect transistor. Using π-π stacking, 1-pyrenebutanoic acid succinimidyl ester was immobilized onto the graphene film to serve as a medium for anchoring the probe aptamer. The fluorophore-labeled target DNA subsequently underwent hybridization with the probe aptamer, thereby forming a fluorescence detection channel.

This paper presents a novel approach using three channels of light, electricity and magnetism for the detection of single-stranded DNA, accompanied by the design of a microfluidic detection platform integrating biosensor chips. Remarkably, the detection limit achieved is 10 pm, with an impressively low relative standard deviation of 1.007%.

By detecting target DNA, the photo-electro-magnetic multi-sensor graphene field-effect transistor biosensor not only enhances the reliability and efficiency of detection but also exhibits additional advantages such as compact size, affordability, portability and straightforward automation. Real-time display of detection outcomes on the host facilitates a deeper comprehension of biochemical reaction dynamics. Moreover, besides detecting the same target, the sensor can also identify diverse targets, primarily leveraging the penetrative and noninvasive nature of light.

This paper aims to investigate the bond strength of metakaolin-based geopolymer mortar with cement mortar.

The mortar-mortar bond strength is assessed by slant shear and split tensile tests; pure shear strength is evaluated by Mohr’s criterion for result validation. Metakaolin-based geopolymer mortar is cast over the cured cement mortar specimen with two levels of surface roughness: smooth or grooved interface. The influence of the alkaline solution to metakaolin ratio on geopolymer bond strength is studied. Compressive strength, ultrasonic pulse velocity, permeability and flow table tests are also performed.

The paper’s findings are highlighted as follows: (1) strong mortar-mortar bond properties achieved for geopolymer mortar in all tests and conditions and validated by Mohr’s criterion and pure shear, (2) a lower alkaline solution to metakaolin ratio achieves higher bond strength to Portland cement mortar and (3) geopolymer mortar has higher compressive strength and ultrasonic pulse velocity than cement mortar at all curing ages; additionally, it is more flowable and less permeable.

The full replacement of Portland cement with metakaolin, a more sustainable cementitious material, will contribute to the decarbonization of the construction industry.

Limited research has been carried out on the bond strength of metakaolin-based geopolymer mortar to Portland cement mortar. Also, computing the pure shear using Mohr’s circle criterion of metakaolin-based geopolymer to validate the results can be considered original.

The modern fairy tale hero identity falls into a general spectrum of tropes that spans from the charming prince who seals the fate of the beautiful princess with a kiss to borderline villains with little break in this spectrum. The Witcher's Geralt of Rivia brings to light an often overlooked hero's identity by representing neither ends of this heroic spectrum but rather a different breed of hero entirely. We argue that Geralt of Rivia differs from the typical representation of the fairy tale hero by embodying the spirit of the Huntsman archetype as depicted in stories such as Snow White and Little Red Riding Hood.

This creates a new means of exploring fairy tales as genres by giving perspective to the bloodier, messier sides of these tales which have since deviated from their darker origins. Geralt exists as neither hero nor antihero, but rather a sword-for-hire who cleans up messes that ‘heroes’ otherwise cannot or will not handle themselves. Across his depictions in the books, games, and show, Geralt involves himself as a witcher; hunter of monsters. Geralt's method in overcoming this style of quest is unlike the usual hero. Standing in for the Huntsman, Geralt understands the nature and balance of man and beast and carries this responsibility while looking to accomplish his goals. In this chapter, we seek to document and bring to light this underrepresented style of hero that the witcher has to offer to show that such a hero needs not be black nor white.

This paper aims to explore the current stage of biodiversity preservation in higher education institutions (HEIs), using samples from German universities and investigating three different dimensions, namely, existing approaches, challenges and future developments.

Semistructured expert interviews were conducted with employees from 14 German Universities. To analyze the data, both deductive and inductive methods of content analysis were conducted to systematically code the results.

This research shows that efforts for biodiversity preservation are frequently made in the areas of student and staff initiatives, green space management, as well as in research and teaching. However, German HEIs face numerous hurdles such as interest conflict, lack of prioritization and financial restrictions, some of which are difficult to overcome. In the future, HEIs should seek a deeper integration of biodiversity into curricula to further raise biodiversity awareness.

This study provides practical implications by providing good practices, which can serve as a guide for implementing measures for biodiversity preservation. By understanding the struggles and future expectations, stakeholders and policymakers could promote targeted measures and relevant policies to advance biodiversity initiatives at and beyond universities. Moreover, the research shows the importance of involving students and staff actively in the planning and executing stage for biodiversity preservation through initiatives to achieve green campuses.

The paper presents an essential research field which is still in its earlier stage. To the best of the authors’ knowledge, it is the first study that focuses on German Universities in this context. This study adds value in providing in-depth insights into this topic to raise awareness of biodiversity preservation in both practice and research.

Ensuring high water quality is crucial for safeguarding public health, as contaminated water can pose significant risks to consumers’ well-being. This study aims to evaluate the microbiological and chemical quality of bottled water brands commonly consumed in Dodoma, Tanzania.

A total of 36 samples from 12 brands were collected between January and March 2023 and analyzed for microbiological and general water quality parameters.

Microbial analysis found that 42% of brands tested positive for coliform bacteria, while opportunistic pathogens Aeromonas hydrophila and Pseudomonas aeruginosa were detected in 25% and 17% of samples, respectively. For chemical composition, 42% of brands exceeded the World Health Organization guideline value of 1.5 mg/L for fluoride. However, no other parameters exceeded national drinking water standards. Statistical analysis revealed significantly higher measured fluoride levels compared to values declared on product labels (paired t-test, p = 0.003). A moderate positive correlation between fluoride and conductivity (r = 0.52, p = 0.045) indicated possible geological influences on water chemistry.

To enhance the study’s comprehensiveness, exploring temporal and spatial variations among water brands, including samples from typically clean environments such as supermarkets, could have been beneficial in identifying underlying factors. Additionally, investigating the entire manufacturing process, from production to end-user, could have provided insights into unforeseen deviations in quality. Furthermore, the use of pour plating techniques at 37°C for microbial analysis, while suitable for resource-limited settings, may not have fully captured coliform diversity compared to membrane filtration and differential temperature incubation as per standard methods. This could partly explain the detection of heterotrophs without higher coliform counts in some samples.

This study provides baseline data on the bacteriological and inorganic chemical quality of bottled water in Dodoma. Detectable microbial contaminants and significant exceedances of fluoride guidelines in some products raise public health concerns.

While existing studies focus on bottled water quality at production facilities, this research highlights the overlooked risks at retail points, where consumers are directly affected.

Metal laser-powder-bed-fusion using laser-beam parts are particularly susceptible to contamination due to particles attached to the surface. This may compromise so-called technical cleanliness (e.g. in NASA RPTSTD-8070, ASTM G93, ISO 14952 or ISO 16232), which is important for many 3D-printed components, such as implants or liquid rocket engines. The purpose of the presented comparative study is to show how cleanliness is improved by design and different surface treatment methods.

Convex and concave test parts were designed, built and surface-treated by combinations of media blasting, electroless nickel plating and electrochemical polishing. After cleaning and analysing the technical cleanliness according to ASTM and ISO standards, effects on particle contamination, appearance, mass and dimensional accuracy are presented.

Contamination reduction factors are introduced for different particle sizes and surface treatment methods. Surface treatments were more effective for concave design features, however, the initial and resulting absolute particle contamination was higher. Results further indicate that there are trade-offs between cleanliness and other objectives in design. Design guidelines are introduced to solve conflicts in design when requirements for cleanliness exist.

This paper recommends designing parts and corresponding process chains for manufacturing simultaneously. Incorporating post-processing characteristics into the design phase is both feasible and essential. In the experimental study, electroless nickel plating in combination with prior glass bead blasting resulted in the lowest total remaining particle contamination. This process applied for cleanliness is a novelty, as well as a comparison between the different surface treatment methods.

This paper argues for an increased volume of references to Gabriel Tarde and Georg Simmel in the field of organization sociology. The text emphasizes the importance of these two sociologists in understanding the role of imperfection in organizing and the phenomena of fashion and imitation in contemporary organizations. Tarde’s theory challenged the antinomy between continuity and discontinuity, considering finite entities as cases of infinite processes and stable situations as transitory. Simmel’s theory of fashion explores the democratic and democratizing nature of fashion, which satisfies the demand for social adaptation and differentiation. They both saw fashion as a selection mechanism for organizational forms and managerial practices. Furthermore, referring to Tarde and Simmel can help counter the overemphasis on identity construction and the neglect of alterity in social sciences. The construction of identity often overlooks the inevitability of difference and alterity, which are essential aspects of collective projects. Lastly, this paper discusses Simmel’s concept of the stranger and its relevance in analyzing the experiences of foreigners and their potential advantages as “double strangers” in academia and society. The conclusion is that Tarde and Simmel’s contributions offer valuable insights for understanding the dynamics of management, organizing, and social interactions in contemporary organizations.