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In order to create alloys with exceptional properties for orthopedic uses, this study focuses on the impact of zirconium (Zr) content on the structural, electrochemical, and tribological qualities of nanostructured Ti–25NbxZr [x = 5, 10, 15, 20, 25, and 30 atomic (at.) %] alloys. The structural evolution was investigated using XRD and SEM techniques. The mechanical characteristics of the produced alloys, including Vickers hardness and Young’s modulus, were measured. In addition, the corrosion tests were performed using the OCP, EIS, and PD methods in Ringer’s solution within the independent pH range at 37°C. A ball-on-disc tribometer was used to investigate the tribological behavior of the alloys under various loads and wet conditions using the Ringer solution. It has been verified that Zr content (at. %) in the alloys had an impact on their morphologies, structural evolution, and mechanical characteristics. According to the morphological analysis, the particle and crystallite size decreases with increasing Zr content. Young’s modulus and Vickers hardness show the same tendency. The EIS data demonstrated that a single passive film formed on the alloy surfaces, and the addition of Zr enhanced the corrosion resistance of the passive films. The polarization curves demonstrate that the alloys had low corrosion current densities and large passive areas without the passive films disintegrating. Likewise, the inclusion of Zr resulted in a reduction in the corrosion and passive current density values. All of these results suggested that the titanium alloys exhibit a more noble electrochemical activity caused by Zr. From the tribological perspective, it was found that the friction coefficient of the alloys reduced with increasing Zr content.
Infections with COVID-19 in enclosed public spaces, where virus-laden aerosol particles can accumulate over time, have significantly contributed to the rapid spread of the virus. It is therefore of great importance to understand the transport and dispersion process of aerosol particles in such spaces, especially against the background of future pandemics. In this work, we present a Lagrangian-Particle-Tracking experiment to assess the mixed convective flow in a classroom with different ventilation strategies. For this purpose, thermal plumes were created by heated dummies, and a collimated LED light-sheet with ~0.4 m thickness was used for illumination of helium filled soap bubbles (HFSB) acting as passive tracer particles. In this way, the Lagrangian trajectories of the particles were recorded at two approximately 4.2 m × 2.8 m large fields using the novel 2D-Shake-The-Box-Method. As a result, time-resolved trajectories of over 300,000 simultaneously tracked HFSB have been reconstructed, so that both small-scale and large-scale properties of the flow are visualized quantitatively across the entire cross-section of the room. The trajectories show that the thermal plumes create lengthwise circulating vortices, which cannot be destroyed across the entire cross-section of the room by opening or tilting a window. Furthermore, the mixing in the room through the operation of an air purifier is higher compared to opening a window, which suggests that this strategy in combination with its air filtering capability is the most effective strategy to prevent infections.
This publication has been written in response to the 8th Sino-German Conference held from June 15 to 17, 2023 at the Brandenburg University of Technology in Cottbus, Germany. Contextualising "SARS-CoV-2 in technology and environment in science, engineering and art", the conference sought to exchange on researching current evolving technoscientific lifeworlds, on pandemic socio-technical environments, and on relations of transcultural political economies. Drawn on the various concerns running through the conference's lively variety of topics, the essay addresses problematic ways of scientific knowledge productions through visual materials. Mostly used decoratively, rarely adequately referenced, these materials reveal risky imprints. Consequently, it is well worth taking a closer look at where, how, and for which reasons visual materials are mobilized in academia.
The accumulation of heavy metal in oil palm plantation soils is a growing concern due to its potential environmental and health implications. This study aimed to investigate the accumulation of heavy metal on oil palm plantation soil fertilized with palm oil mill effluent POME. The research appraised the extent of contamination in oil palm plantation soil in Ikpoba Okha local government area of Edo state Nigeria. Soil sample were collected from different soil depth ranges 0-15cm, 15-30cm, 30-45cm, 45-60cm and 60-70cm of POME treated soil at five locations (2-6) and the control location 1 within oil palm plantations. The concentrations of the heavy metals (Cu, Mn, Zn, Ni, Pb, Cd, Cr, As, Hg) were analyzed using the atomic absorption spectrometry (AAS). The results show that the application of POME as fertilizer led to increased concentration of heavy metals. Significant difference at (p < 0.05) level in concentration was obtained across the different depths of the treated locations for the metals compared to the background location. However, As and Hg were not significantly different between the POME treated soil and control location. The impacts of POME treatment have greater effects on the concentration of the essential metal (Cu, Mn, Zn, Ni) compare to the non-essential metal (Pb, Cr, Cd, As, Hg). The concentration of the metals was below the permissible limits of regulatory standards. The increase concentration of the essential metal could have potential implications of soil contamination due to accumulation over time. The soil had contamination factor and pollution load index of low to moderate contamination and pollution. The control location 1 had the closest similarity with the location 6. The study proposed recommendation for POME usage as organic fertilizer in agricultural soil but with close monitory.
While urban life can be characterized by endeavors to settle stable and safe environments, for many people, urban space is rarely stable or safe; it is uncertain, troubled, imbued with challenges and perpetually under pressure. As the concept of unsettled appears to define the contemporary urban experience, this multidisciplinary book investigates the conflicts and possibilities of settling and unsettling through open and speculative analysis. The analytical prism of unsettled renders urban space an indeterminate ground unfolding through routines, temporalities and contestations in constant tension between settling and unsettling. Such contrasting experiences are contingent on how urban societies confront, undergo and overcome turbulence and difficulties in time and space. Contributions drawing on theoretical reflections and empirical accounts—from Argentina, Austria, Germany, Greece, Italy, the Netherlands, the UAE, the UK, the USA and Vietnam—give insights into plural occurrences of the unsettled, which might tie down or unleash transformative, liberatory and emancipatory potentials. This book is for students, professionals and researchers interested in the uncertainties, foundations, disturbances, inconsistencies, residuals and blind fields, which constitute the urban both as lived space and as social, cultural and political ideal.
Assessing alternative agricultural water management strategies requires long-term field trials or vast data collection for model calibration and simulation. This work aims to assess whether an uncalibrated agro-hydrological model using global input datasets for climate, soil and crop information can serve as a decision support tool for crop water management under data scarcity. This study employs the Cool Farm Tool Water (CFTW) at eight eddy covariance sites of the FLUXNET2015 dataset. CFTW is tested using global (CFTWglobal) and local (CFTWlocal) input datasets under current and alternative management scenarios. Results show that the use of global datasets for estimating daily evapotranspiration had little effect on the median Root Mean Square Error (RMSE) (CFTWglobal: 1.70 mm, CFTWlocal: 1.79 mm), while, however, the median model bias is much greater (CFTWglobal: - 18.6%, CFTWlocal: - 4.3%). Furthermore, the periods of water stress were little affected by the use of local or global data (median accuracy: 0.84), whereas the use of global data inputs led to a significant overestimation of irrigation water requirements (median difference: 110 mm). The model performance improves predominantly through the use of more representative local precipitation data, followed by local reference evapotranspiration and soil for some European growing seasons. We identify model outputs that can support decision-making when relying on global data, such as periods of water stress and the daily dynamics of water use. However, our findings also emphasize the difficulty of overcoming data scarcity in decision-making in agricultural water management. Furthermore, we provide recommendations for enhancing model performance and thus may increase the accessibility of reliable decision support tools in the future.
Lösungen zu Magazin 1 – Dreiecke : alles zu den Themen rechtwinkliges und allgemeines Dreieck
(2022)
Beim Magazin „Lösungen zu Magazin 1“ zum Serious Game re:construction handelt es sich um das Lösungsheft zum Thema Dreiecke. Neben spannend verpackter Theorie zu den Themen rechtwinkliges und allgemeines Dreieck befinden sich in diesem Heft auch die Lösungen zu Übungsaufgaben, Rätseln und Experimenten zum Nachmachen. Ebenso gibt es wissenswerte Fakten, Witze sowie Verweise (via Link und QR-Code) zu Lernvideos und anderen interessanten Quellen, um sich das Thema der Dreiecke zu erschließen. Das Magazin 1 ohne Lösungen finden Sie im „Magazin 1“. Zu den Lernzielen gehören: Eigenschaften des rechtwinkligen Dreiecks erkennen; Seiten im rechtwinkligen Dreieck benennen; Sinus, Cosinus, Tangens im rechtwinkligen Dreieck anwenden; Satz des Pythagoras anwenden; Eigenschaften des allgemeinen Dreiecks kennen; Cosinussatz im allgemeinen Dreieck anwenden; Sinussatz im allgemeinen Dreieck anwenden.
Im Magazin 3 zum Serious Game re:construction geht es um das Thema Kraft zerlegen: grafische und analytische Kräftezerlegung. Neben spannend verpackter Theorie zu beiden Themen befinden sich in diesem Heft auch Witze, Übungsaufgaben, Rätsel und Experimente zum Nachmachen. Ebenso gibt es Verweise (via Link und QR-Code) zu Lernvideos und anderen interessanten Quellen, um sich das Thema der Kräftezerlegung zu erschließen. In diesem Magazin sind keine Lösungen enthalten. Diese sind im Magazin „Lösungen zu Magazin 3“ enthalten. Zu den Lernzielen gehören: Definition der Kraftzerlegung kennen; Grund für die Zerlegung von Kräften kennen; Kraftzerlegung mit Koordinatensystem, Maßstab & Kraftvektor durchführen; Kraftzerlegung mit Winkelfunktionen Sinus & Cosinus durchführen; Kraftzerlegung mit analytische Methode durchführen; Zusammenhang zwischen rechtwinkligem Dreieck & Kraftkomponenten erkennen.