710 research outputs found
2.5D Playgrounds for Bogota: Stimulate Playful Actions in Public Spaces by Redesigning Ground Surfaces into 2.5D Architectural Compositions
No full textHow to construct the commons with the power of play? How to reactivate leftover public spaces in central Bogota by architectural interventions that stimulate playful actions? I shift my focus from buildings to the ground surfaces, and redesign them into a constellation of “2.5D architectural composition”. “2.5D” refers to an abstract composition of the ground surface, including composing different ground materials on the planer dimension (2D), and create minor vertical level difference by sinking, elevating, folding and undulating (0.5D).These compositions become abstract playgrounds. They should be unconventional as the playful quality is achieved by manipulating the ground surface rather than adding playful objects. Yet, they are humble as the minor level difference and usage of familiar materials enable them to merge into the local context. I expect that these “2.5D playgrounds” will bring Bogota citizens together, stimulate their playful actions, and enable them to recognize the scattered playgrounds in the city as a constellation of “playful commons”.1. Johan Huizinga, Homo Ludens 2. Quentin Stevens, The Ludic City 3. Liane Lefaivre, Ground-up City: Play as a Design Tool 4. Liane Lefaivre and Alexander Tzonis, Aldo van Eyck: Humanist Rebel 5. Astrid Zimmermann, Constructing Landscape: Materials, Techniques, Structural Componentsconstructing the commons; position in practiceArchitecture, Urbanism and Building Sciences | Methods and Analysis | Positions in Practic
Colored Water: Designing a resilient landscape framework that facilitates water safety and batik development in Pekalongan city
No full textAs one of the most important ecosystems on the planet, the coastal zone accommodates a denser population than the hinterland and faces faster urbanization and higher population growth. Meanwhile, the coastal zone is exposed to several climate change disasters in the context of a sensitive environment dominated by water. It is considered with limited resources and capacities to respond to stress, thus the coastal zone is also one of the most vulnerable ecosystems. This master thesis in Landscape Architecture focuses on the Northern Java island, specifically Pekalongan city, Indonesia. The local see a dilemma between natural resources and batik development, for this dominant industry is highly reliant on water. Pekalongan people actively fight against natural disasters and try to boom the cultural significance. But, without understanding the natural process and resilience thinking, the interventions are slightly ineffective, and even could be counterproductive from a long-term perspective. Therefore the objective of the thesis is to create a resilient landscape framework to facilitate water safety and batik development in Pekalongan city by focusing on the three dominant water-related design assignments, known as water circulation, discharge capacity, and coastal protection. Moreover, the project aims to consolidate and enhance the cultural significance of batik and raise awareness of landscape potentials. Under the resilient landscape theoretical framework, with the guidance of landscape- based solutions, the project seeks to build a new relationship between people and nature to mitigate the threats of climate change disasters and batik development from a long term and sustainable perspective. Design research and research by design provide the methods to conduct the investigations. The design work is conducted in three different scales, proposing strategies on a regional scale; detailed elaboration on selected sites; infrastructure design. Besides, a toolbox is also included to provide inspirations and glues for coastal zones which face similar threats and dilemmas as Pekalongan city.Architecture, Urbanism and Building Sciences | Landscape Architectur
Molecular dynamics simulation of clay hydration inhibition of deep shale
No full textIn the process of the exploitation of deep oil and gas resources, shale wellbore stability control faces great challenges under complex temperature and pressure conditions. It is difficult to reflect the micro mechanism and process of the action of inorganic salt on shale hydration with the traditional experimental evaluation technology on the macro effect of restraining shale hydration. Aiming at the characteristics of clay minerals of deep shale, the molecular dynamics models of four typical cations (K+, NH4+, Cs+ and Ca2+) inhibiting the hydration of clay minerals have been established by the use of the molecular dynamics simulation method. Moreover, the micro dynamics mechanism of typical inorganic cations inhibiting the hydration of clay minerals has been systematically evaluated, as has the law of cation hydration inhibition performance in response to temperature, pressure and ion type. The research indicates that the cations can promote the contraction of interlayer spacing, compress fluid intrusion channels, reduce the intrusion ability of water molecules, increase the negative charge balance ability and reduce the interlayer electrostatic repulsion force. With the increase in temperature, the inhibition of the cations on montmorillonite hydration is weakened, while the effect of pressure is opposite. Through the molecular dynamics simulation under different temperatures and pressures, we can systematically understand the microcosmic dynamics mechanism of restraining the hydration of clay in deep shale and provide theoretical guidance for the microcosmic control of clay hydration.</p
Surface galvanic formation of Co-OH on Birnessite and its catalytic activity for the oxygen evolution reaction
No full textLow cost, high-efficient catalysts for water splitting can be potentially fulfilled by developing earth abundant metal oxides. In this work, surface galvanic formation of Co-OH on K0.45MnO2 (KMO) was achieved via the redox reaction of hydrated Co2+ with crystalline Mn4+. The synthesis method takes place at ambient temperature without using any surfactant agent or organic solvent, providing a clean, green route for the design of highly efficient catalysts. The redox reaction resulted in the formation of ultrathin Co-OH nanoflakes with high electrochemical surface area. X-ray adsorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) analysis confirmed the changes in the oxidation state of the bulk and surface species on the Co-OH nanoflakes supported on the KMO. The effect of the anions, chloride, nitrate and sulfate, on the preparation of the catalyst was evaluated by electrochemical and spectrochemical means. XPS and Time of flight secondary ion mass spectrometry (ToF-SIMS) analysis demonstrated that the layer of CoOxHy deposited on the KMO and its electronic structure strongly depends on the anion of the precursor used during the synthesis of the catalyst. In particular, it was found that Cl favors the formation of Co-OH, changing the rate determining step of the reaction, which enhances the catalytic activity towards the OER, producing the most active OER catalyst in alkaline media
The Reinforcement and Reproduction of Gender Stereotypes in High Schools in Mainland China
No full textNickel confined in 2D earth-abundant oxide layers for highly efficient and durable oxygen evolution catalysts
No full textLow cost, high-efficiency catalysts towards water splitting are urgently required to fulfil the increasing demand for energy. In this work, low-loading (<20 wt%) Ni-confined in layered metal oxide anode catalysts (birnessite and lepidocrocite titanate) have been synthesized by facile ion exchange methodology and subjected to systematic electrochemical studies. It was found that Ni-intercalated on K-rich birnessite (Ni-KMO) presents an onset overpotential (ηonset) as low as 100 mV and overpotential at 10 mA cm-2 (η10) of 206 mV in pH = 14 electrolyte. By combining electrochemical methods and X-ray absorption and emission spectroscopies (XAS and XES), we demonstrate Ni sites are the active sites for OER catalysis and that the Mn3+ sites facilitate Ni intercalation during the ion-exchange process, but display no observable contribution towards OER activity. The effect of the pH and the nature of the supporting electrolyte on the electrochemical performance was also evaluated.</p
Relationship between cultivated land use functions and land rental behavior of rural households: empirical evidence from different dominant functional regions in central China
No full textPredicaments and Countermeasures of Multimodal Application for English Teaching in Higher Vocational Colleges
No full textIn the intelligent learning era, multimodal data is an important carrier to accurately depict learners learning situations. Studying the teaching of multimodal learning analytics is helpful to restore original teaching process, reveal teaching rules, and help learners grow. This paper reviews the current situation of multimodal learning analytics at home and abroad, and points out that multimodal application for English teaching in higher vocational colleges currently faces difficulties such as the weighting and proportion of multiple data sources, the protection of ethical privacy, and the acquisition of platform data. With the learners needs based on a questionnaire survey, the research believes that a multi-modal and data-driven English teaching system should be built, a reasonable learning ability evaluation system should be created, and the characteristics of the development of English teaching in higher vocational education should also be integrated, so as to promote the empowerment of education big data technology, and high-quality development of intelligent education project and higher vocational education
Rotational dynamics of a particle in a turbulent stream
No full textThe paper presents results for the resolved numerical simulation of a turbulent flow past a homogeneous sphere and a spherical shell of equal mass and radius (and, therefore, with a larger moment of inertia) free to rotate around a fixed center. This situation approximates the behavior of a particle whose relative motion with respect to the fluid is driven by external forces, such as a density difference in a gravitational field. Holding the center fixed makes it possible to have precise information on the turbulent flow incident on the particle by repeating the same simulations without the particle. Two particle Reynolds numbers based on the mean velocity,
Re
p
=
80
and 150, are investigated; the incident turbulence has
Re
?
=
36
and 31, respectively. The particle diameter is an order of magnitude larger than the Kolmogorov length scale and close to the integral length scale. The turbulent eddies that interact most strongly with the particle are characterized. Their size is found to increase with
Re
p
due to the interplay of the convection timescale, the particle timescale, and the eddy timescale, but it remains of the order of the particle diameter. The sign of the hydrodynamic torque is likely to persist much less than the convection time, although longer durations are also found, revealing the effect of occasional interactions with larger eddies. The autocorrelation of the torque changes sign at shorter and shorter fractions of the convection time as the Reynolds number increases. Significant cross-stream forces are found. An analysis of their magnitude shows that they are mostly due to induced vortex shedding combined with a weaker Magnus-like mechanism
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