Mineral scaling is one of the primary factors that constrain the performance of membrane desalination. However, compared to numerous studies on organic and biological fouling, less effort has been ...invested in understanding the mechanisms of mineral scaling. Although anti-fouling membranes have been successfully fabricated to mitigate organic and biological fouling, little progress has been made on the design and fabrication of scaling-resistant membranes. In this review, we discuss the occurrence and consequences of mineral scaling in different membrane desalination processes, and emphasize the complex nature of membrane scaling regulated by feedwater chemistry. We describe established theories associated with mineral scaling, and highlight the knowledge and technology advances in the field of biomineralization that demonstrates the important role of surface chemistry in controlling mineral formation. Current strategies of scaling mitigation are predominantly independent of membrane materials, while the feasibility of developing scaling-resistant membranes has been indicated but not fully achieved in the literature. Accordingly, potential design strategies and challenges associated with the development of novel membrane materials with improved scaling resistance are discussed, and future research needs are proposed.
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•Membrane scaling varies according to feedwater chemistry and desalination technologies.•Surface chemistry regulates mineral formation in biomineralization.•Current strategies of scaling control are dominantly independent of membrane materials.•Membrane scaling can be altered via tuning membrane surface chemistry or topology.•The design of scaling-resistant membrane is challenging due to the complexity of scaling.
Parmi les différents procédés d’élaboration de minigranules, le procédé d’extrusion-sphéronisation présente de nombreux avantages, puisqu’il permet notamment d’élaborer des minigranules fortement ...chargées en principe actif et d’éviter l’emploi de solvants organiques. Ce travail a pour objectif de comparer les performances de plusieurs systèmes d’extrusion à vis, de l’échelle du laboratoire jusqu’à la transposition à l’échelle industrielle. Pour cela, des plans d’expériences ont été construits afin d’identifier les variables critiques et de sélectionner l’extrudeur le plus favorable selon différentes approches spécifiques à cette étude. En effet, le système d’extrusion idéal est défini dans ce travail comme celui donnant les meilleurs résultats en termes de productivité et de caractéristiques des minigranules (« qualité »), entraînant le moins d’impact sur le produit après transposition d’échelle (« transposabilité »), montrant le moins d’influence sur le produit lorsque la formule utilisée change (« robustesse »), et permettant d’ajuster ou d’améliorer la qualité des minigranules lorsque les conditions opératoires varient (« flexibilité »). Quelle que soit l’approche étudiée, les résultats ont permis de mettre en évidence l’influence de paramètres critiques et de leurs interactions sur les différentes réponses et ont montré des différences entre les différents systèmes d’extrusion. L’étude à l’échelle du laboratoire a permis de comparer les extrudeurs radial, dôme et frontal et a mis en évidence l’intérêt des systèmes frontal et dôme en termes de qualité des minigranules, et du système radial en termes de robustesse et de flexibilité du procédé. L’étude à l’échelle industrielle a permis de comparer les extrudeurs radial et frontal, et a permis d’identifier l’extrudeur frontal comme étant le plus favorable en termes de qualité des minigranules, de robustesse, de flexibilité et de transposabilité. Les conclusions observées à l’échelle industrielle sont donc différentes de celles considérées à l’échelle du laboratoire, pour l’étude comparative des différents systèmes. Cela confirme l’importance de tester les systèmes à échelle industrielle avant l’acquisition d’un équipement.
Among the various methods of developing minigranules, extrusion-spheronization has many advantages, particularly since it allows to develop minigranules highly charged with active pharmaceutical ingredient and to avoid the use of organic solvents. This work aims to compare the performance of several extrusion screws systems, from the lab to the scale-up at industrial scale. Designs of experiments were built to identify critical variables and compare the extruder in terms of different approaches specific to this study. As a matter of fact, the ideal extrusion system is defined in this work as the one which gives the best results in terms of productivity and pellets characteristics (“quality”), the one which shows less impact on the product after scaling-up (“scalability”), the one which shows the less influence on these same properties when the formula used changes (“robustness”), and the one which allows the possibility to adjust or improve pellets properties with operating variables (“flexibility”). Whatever the approach studied, the results allowed to highlight the influence of critical parameters and their interactions on the different responses and showed differences between the different extrusion systems. The study at lab scale compared radial, dome and axial extruders and underlined the interest of axial and dome systems in terms of pellets quality, and radial system in terms of process robustness and flexibility. The study at industrial scale compared radial and axial systems, and identified the axial system as the most favorable in terms of pellets quality , robustness, flexibility and scalability. The conclusions observed at industrial scale are different from those observed at lab scale for the different systems comparative study. This confirms the importance to test systems at industrial scale before investing in one equipment.
•A review of the management literature identifies four different uses of “scaling”.•Research distinguishes between market, volume, financial, organizational scaling.•We develop an inclusive ...definition of scaling.•We propose measures to assess the scaling performance of organizations.•We propose avenues for future research on scaling.
Scaling has recently found its way into the academic discourse. However, the term has been used inconsistently and mixed up with other terms such as growth. To overcome these impediments to knowledge accumulation, we review the literature, identifying four broad applications of the scaling concept: market scaling, volume scaling, financial scaling, and organizational scaling. Building on their commonalities and setting scaling apart from growth, we develop an inclusive definition of scaling: Scaling describes an increase in the size of a focal subject that is accompanied by a larger-than-proportional increase in the performance resulting from the said subject. We further propose a set of measures that makes it possible to compare the scaling performance of organizations and track their scaling performance over time. Based on our insights as well as a list of “hot topics” in the management literature, we conclude by identifying promising areas for further research.
This open access textbook offers a practical guide into research ethics for undergraduate students in the social sciences. A step-by-step approach of the most viable issues, in-depth discussions of ...case histories and a variety of didactical tools will aid the student to grasp the issues at hand and help him or her develop strategies to deal with them. This book addresses problems and questions that any bachelor student in the social sciences should be aware of, including plagiarism, data fabrication and other types of fraud, data augmentation, various forms of research bias, but also peer pressure, issues with confidentiality and questions regarding conflicts of interest. Cheating, ‘free riding’, and broader issues that relate to the place of the social sciences in society are also included. The book concludes with a step-by-step approach designed to coach a student through a research application process.
Edible food packaging, produced from edible polymers, is a kind of packaging suitable for human consumption along with the contained food. Despite many advantages, the edible films are still produced ...in laboratory scale due to problems, such as lack of poor elongation, safety and health issues, high cost, processing difficulties, etc. It is essential to overcome these difficulties for scaling up the production to industrial scale and making the edible films commercially successful.
Even though some reviews on edible films and coatings have little discussed, there is no dedicated article on scaling up difficulties and commercial aspects of edible films. This article reviews the research progress, confronting problems, and research opportunities ahead for the industrial scaling up and commercial success for edible films in food packaging.
Incorporation of plasticizer, production of multilayers, composites, and nanocomposite films improved the properties significantly, but some fundamental research on the key factors are still not investigated. Current laboratory scale production of edible films has problems like inability to make continuous films, long drying time and inaccurate thickness control, which must be addressed before the industrial scaling up production. Lack of evidence on edibility, biodegradability, toxicological and health effects, inadequate marketing, lack of awareness, cultural issues, can affect the food safety and customer acceptance. Future research must address all these problems from the view of industrial scaling up and commercial aspects in order to make the industrially viable and commercially successful edible films.
•Composite films are stronger and effective than neat and multi-layer edible films.•Continuous film forming and fast drying are essential for industrial scale-up.•Nanotechnology offers competitive film properties but needs more research.•Lack of biodegradability and edibility tests questions film consumer's safety.•Marketing strategies and low cost production increase consumer acceptance.
Most of the planet’s population currently lives in urban areas, and urban land expansion is one of the most dramatic forms of land conversion. Understanding how cities evolve temporally, spatially, ...and organizationally in a rapidly urbanizing world is critical for sustainable development. However, few studies have examined the coevolution of urban attributes in time and space simultaneously and the adequacy of power law scaling across cities and through time, particularly in countries that have experienced abrupt, widespread, political and economic changes. Here, we show the temporal coevolution of multiple physical, demographic, socioeconomic, and environmental attributes in individual cities, and the cross-city scaling of urban attributes at six time points (i.e., 1978, 1990, 1995, 2000, 2005, and 2010) in 32 major Chinese cities. We found that power law scaling could adequately characterize both the cross-city scaling of urban attributes across cities and the longitudinal scaling describing the temporal coevolution of urban attributes within individual cities. The cross-city scaling properties demonstrated substantial changes over time signifying evolved social and economic forces. A key finding was that the cross-city linear or superlinear scaling of urban area with population contradicts the theoretical sublinear power law scaling proposed between infrastructure and population. Furthermore, the cross-city scaling between area and population transitioned from linear to superlinear over time, and the superlinear scaling in recent times suggests decreased infrastructure efficiency. Our results demonstrate a diseconomy of scale in urban areal expansion that indicates a significant waste of land resources in the urbanization process. Future planning efforts should focus on policies that increase urban land use efficiency before continuing expansion.
Testing the ν max scaling relation Coelho, H. R.; Chaplin, W. J.; Basu, S. ...
EPJ Web of Conferences,
01/2015, Letnik:
101
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
Two key global seismic quantities are relevant to estimate the fundamental properties of a star: the frequency of maximum power (νmax) and the large frequency separation (Δν). The focus of this work ...is to test the νmax scaling relation in order to ascertain it’s level of accuracy. Here we report our results using artificial data and real Kepler data, based on a grid-modelling approach.
Abstract 1358 Scaling relationships in animal nervous systems Marin, Ana Sutulov; Arroyo, Jose; Hernandez, Juan ...
Journal of biological chemistry/The Journal of biological chemistry,
March 2024, 2024-03-00, Letnik:
300, Številka:
3
Journal Article
The smacof package offers a comprehensive implementation of multidimensional scaling (MDS) techniques in R. Since its first publication (De Leeuw and Mair 2009b) the functionality of the package has ...been enhanced, and several additional methods, features and utilities were added. Major updates include a complete re-implementation of multidimensional unfolding allowing for monotone dissimilarity transformations, including row-conditional, circular, and external unfolding. Additionally, the constrained MDS implementation was extended in terms of optimal scaling of the external variables. Further package additions include various tools and functions for goodness-of-fit assessment, unidimensional scaling, gravity MDS, asymmetric MDS, Procrustes, and MDS biplots. All these new package functionalities are illustrated using a variety of real-life applications.
While there is some recent empirical research on scale-ups, how digitalized start-ups transition to scale-up remains largely unexplored. Our research furthers our understanding of digitalized ...scale-ups and their growth process by examining how digitalized start-ups transform during scaling. We focus on internal workings of digitalized scale-ups and the transformation therein distinct from the firms' start-up phase. Drawing on firm growth literature, we use a qualitative methodology consisting of in-depth, semi-structured interviews with digitalized scale-up founders, finding commonality in their scaling process. We find scaling in digitalized firms is a complex mix of related internal activities, priorities, and trade-offs in pursuit of scaling process goals. Four priorities, goals, and related tensions relevant to their scaling process emerge from our analysis. We also find balancing tensions to optimize trade-offs require dynamic capabilities during scaling in digitalized firms. We conclude that although their growth patterns may be heterogeneous, digitalized scale-ups have commonality in their scaling process. The study furthers our understanding of the firm growth process and nascent literature specific to scaling digitalized firms, contributing towards a scaling process framework for digitalized scale-ups. We uncover opportunities to further develop theory, sharpening it with greater operative insight based on today's digitalized scale-ups.
•Digitalized scale-ups share commonality in scaling processes despite heterogeneity.•Scaling involves a complex mix of internal activities, priorities, and trade-offs.•Capacity building, process innovation and scale economics are prioritized.•In-depth interviews with scale-up founders inform a scaling process framework.•Explore founder learning agility and scaling process tensions in future research
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