Scale Manipulation Research Articles

Anisotropic porosity and interface synergy enhanced gas permselectivity in heterolayer metal-organic framework membrane.

The pursuit of sustainable, carbon-free separation technology hinges on the efficient separation of gas mixtures with high separation factors and flow rates, i.e. high permselectivity. However, achieving this objective is arduous due to the meticulous engineering at the angstrom scale and intricate chemical manipulation required to design the pores within membranes. To address this challenge, a proof-of-concept for an anisotropic porous membrane has been devised. Employing a meticulous step-by-step methodology, two distinct porous metal-organic frameworks (MOFs) are integrated to form a monolithic anisotropic membrane. By harnessing pore anisotropy (3.4 to 6 Å) aligned with the gas permeation direction and a unique interface characterized by cross-linked pores derived from the two distinct MOFs, this membrane transcends the performance limitations inherent in the individual MOF membranes (~45% enhanced selectivity). This approach not only sheds light on the heterolayer membrane design strategy but also elucidates the intricate CO2/N2 permselectivity relationship inherent in the interface structure.

Microstructural length scale manipulation via solidification and its influence on mechanical behavior in a high-strength intermetallic-based eutectic alloy

Microstructural length scale manipulation via solidification and its influence on mechanical behavior in a high-strength intermetallic-based eutectic alloy

Crouching the tiger, or hiding the dragon? scale in China’s heritage production

In the built heritage studies, the intricate web of social and selective processes that define heritage is evident. These processes are, in many cases, intertwined with the notion of scale, examplified through the production of heritage sites at the local, national, and transnational scales. While heritage and geography scholars have articulated the role played by scale in heritage-making and argue against a rigid, fixed, and hierarchical understanding of scale, they highlight the constant reproduction of scale. There is, so far, limited explanation of how the perception of scale gets reproduced and how crucial actors manipulate scalar power and resources for heritage making and the reproduction of scale. To fill this gap, this paper delves into mainland China’s heritage-making, using the southern Anhui historical villages as an example. Based on intensive 5-month field research, this paper has three findings: 1) The nomination process for a World Heritage Site is notably influenced by politics and selectivity; 2) Diverse stakeholders are pivotal in shaping heritage narratives; 3) Individual contributions to heritage creation directly interact with, and subsequently reshape, ‘scale’, an entity that is simultaneously discursive and tangible. By integrating the notion of ‘scale’ into heritage discussions, we illuminate two concurrent processes: creating hierarchies through rule assimilation by interpreting the UNESCO standard internally and evolving socio-spatial dynamics via the manifestation of individual agency with resource manipulation, scale jumping, and reproduction of scale. This approach aligns with the material orientation in human geography and repositions ‘scale’. Here, it’s not just an epistemological framework but also a tangible force that steers individual perceptions and actions and yields measurable material impacts.

Accurate Wide-Range Scaling Manipulation of the Model with a 6-DOF Tracking Device

In virtual reality applications, translation, orientation, and scaling are the three basic properties of 3D model manipulation. The 6-DOF tracking device can be used to directly manipulate the former two properties. However, the scaling property cannot be directly mapped with a hand-held tracking device because it is physically impossible. In this study, we first compare various schemes for mapping the translation and orientation of a handheld tracking device to the 3D model’s scaling property. Next, we propose a scaling manipulation framework that combines the advantages of different schemes. This enables accurate and natural wide-range scaling with the orthogonal combination design of the translation and orientation data of the tracking device. The efficiency and accuracy of the proposed framework were examined in a user study, which verified that it improved the scaling error of wide-range scaling by over 55% without a significant decrease in time performance. Finally, two scaling scenarios for the application of this framework were presented.

Moderate nitrogen retention in temperate heath ecosystem after elevated CO2, drought and warming through 7 years

AbstractNitrogen (N) dynamic is one of the main controlling factors of responses to climate change in N‐limited terrestrial ecosystems, which rely on nutrient recycling and retention. In this study we investigate the N partitioning in ecosystem compartments of a grassland heath, and the impact of multiple climate change factors on long‐term N retention after 15N pulse labelling. The impacts of elevated carbon dioxide (eCO2), warming and drought and the treatments in combination on ecosystem N retention were investigated in a field scale manipulation experiment. A 6‐year time‐course was assessed by pulse‐labelling with the stable N isotope 15N and by sampling after 1 day, 1 year and 6 years. After 6 years we observed that the total ecosystem retained 42% of the amended 15N across treatments (recovery of the amended 15N in the pool). The fate of the applied 15N was mainly stabilization in soil, with 36% 15N recovery in soil, while the plant compartment and microbial biomass each retained only 1%–2% of the added 15N. This suggests a moderate retention of N, for all treatments, as compared to similar long‐term studies of forest ecosystems. A decreased ammonium and vegetation N pool combined with higher 15N retention in the soil under eCO2 treatments suggests that eCO2 promoted processes that immobilize N in soil, while warming counteracted this when combined with eCO2. Drought treatments contrastingly increased the vegetation N pool. We conclude that as the organic soil layer has the main capacity for N storage in a temperate heathland‐grassland, it is important for buffering nutrient availability and maintaining a resilient ecosystem. However, the full treatment combination of drought, warming and eCO2 did not differ in 15N recovery from the control, suggesting unchanged long‐term consequences of climate change on retention of pulse added N in this ecosystem.

Border Formation

This doctoral thesis examines the militarisation of the Southern border of Hungary as a process of spatial formation, expanding the debate on borders from the political to the architectural arena. Combining spatial theory with empirical research on the case study, the thesis rethinks the border as a complex spatial system, with an agency of its own. From this perspective, it contests the enforcement of spatial boundaries from the above and related ideas of fixity. It brings attention to the agency of space in the advancement of a material becoming; the role of migration in the radical redefinition of meanings and functions of space; and the action of technologies in the strategic manipulation of measures and scales. While conceptualising the border as a space in formation, this thesis builds a diagrammatic method of study and moves the research in an ontoepistemological direction. With the aim of fostering a change in those structures that control the partition and governance of space, this doctoral study calls the discipline of architecture to review its questions, methods, and practices. It invites to use architectural knowledge to engage with borders’ complexity and challenge their established meanings and makings.

Optical redshift and blueshift spectra in monolayer β12 -borophene: Inversion symmetry breaking effects

We have calculated the optical conductivity of monolayer ${\ensuremath{\beta}}_{12}$-borophene in the presence of an inversion symmetry breaking (ISB) field. We theoretically formulate such a field to effectively be induced by a substrate through an orbital hybridization effect in the experimental growth process. In the electronic band structure, the effect of the ISB field on the anisotropic dispersion appears as a perturbed manipulation of the energy scale. Different orientations of dispersion of triplet and Dirac fermions in ${\ensuremath{\beta}}_{12}$-borophene cause anisotropic optical interband transitions. Simulated ISB-induced optical conductivity using the Kubo formula produces various optical redshift and blueshift spectra. The longitudinal (Hall) component of optical conductivity presents a pure redshift (blueshift) spectrum with the ISB field, whereas the coexistence of both redshift and blueshift spectra emerge for the transverse component. This paper is a handful for practical applications in two-dimensional-based optoelectronic devices.

The Effect of the Investigative Report Learning Model on Student’s Perception of Anti-Corruption Behavior Development

This study investigates changes in students' perceptions of anti-corruption behavior in the religious education. This qualitative research analyzes the application of investigative report as a learning model through field observation and in-depth group interviews focusing on religious education subject in high schools. The results of this study showed differences in students’ perceptions before and after the investigation; the investigative report learning model made the high school students have a wider understanding of anti-corruption actions and behavior. By filling out the investigation sheet, students could identify such actions directly in the field, such as at home and the markets. Some of the actions they identified were manipulation of scales, stockpiling of staples, and provision of inappropriate materials. In addition to the investigative report learning model, the religious teachers also made a huge contribution by providing explanations about the relation between the Qur'an and the story of the Prophet Muhammad to stuff findings that are considered acts of corruption.

Secure Digital Voting System Based on Blockchain Technology - A Survey

Online voting is a trend that is gaining momentum in modern society. It has great potential to decrease organizational costs and increase voter turnout. It eliminates the need to print ballot papers or open polling stations— voters can vote from wherever there is an Internet connection. Despite these benefits, online voting solutions are viewed with a great deal of caution because they introduce new threats. A single vulnerability can lead to large- scale manipulations of votes. Electronic voting systems must be legitimate, accurate, safe, and convenient when used for elections. Nonetheless, adoption may be limited by potential problems associated with electronic voting systems. Blockchain technology came into the ground to overcome these issues and offers decentralized nodes for electronic voting and is used to produce electronic voting systems mainly because of their end-to-end verification advantages. On the other hand, the most often mentioned issues in blockchain applications are privacy protection and transaction speed. For a sustainable blockchain- based electronic voting system, the security of remote participation must be viable, and for scalability, transaction speed must be addressed. Due to these concerns, it was determined that the existing frameworks need to be improved to be utilized in voting system.

Augmented Perception Through Spatial Scale Manipulation in Virtual Reality for Enhanced Empathy in Design-Related Tasks

This research explores augmented perception by investigating the effects of spatial scale manipulation in Virtual Reality (VR) to simulate multiple levels of virtual eye height (EH) and virtual interpupillary distance (IPD) of the VR users in the design context. We have developed a multiscale VR system for design applications, which supports a dynamic scaling of the VR user’s EH and IPD to simulate different perspectives of multiple user’s groups such as children or persons with disabilities. We strongly believe that VR can improve the empathy of VR users toward the individual sharing or simulating the experience. We conducted a user study comprising two within-subjects designed experiments for design-related tasks with seventeen participants who took on a designer’s role. In the first experiment, the participants performed hazards identification and risks assessment tasks in a virtual environment (VE) while experiencing four different end-user perspectives: a two-year-old child, an eight-year-old child, an adult, and an adult in a wheelchair. We hypothesized that experiencing different perspectives would lead to different design outcomes and found significant differences in the perceived level of risks, the number of identified hazards, and the average height of hazards found. The second experiment had the participants scale six virtual chairs to a suitable scale for different target end-user groups. The participants experienced three perspectives: a two-year-old child, an eight-year-old child, and an adult. We found that when the designer’s perspective matched that of the intended end-user of the product, it yielded significantly lower variance among the designs across participants and more precise scales suitable for the end-user. We also found that the EH and IPD positively correlate with the resulting scales. The key contribution of this work is the evidence to support that spatial scale manipulation of EH and IPD could be a critical tool in the design process to improve the designer’s empathy by allowing them to experience the end-user perspectives. This could influence their design, making a safer or functionally suitable design for various end-user groups with different needs.

Green synthesis, characterization and biomedical potential of Ag@Au core–shell noble metal nanoparticles

In the current times, nanotechnology has emerged as a field that promises scientific advancement with the manipulation, improvement, and application of near-atomic scale materials.Bimetallic nanoparticles (NPs) have been explored for their wide range of applications owing to their multi-functionalilty. The present study included the synthesis of bimetallic silver@gold (Ag@Au) NPs from aqueous chloroauric acid (HAuCl4) and silver nitrate (AgNO3) making use of ‘green chemistry’ with the extract of Acacia nilotica husk as a reducing and capping agent. The formed bimetallic NPs were characterized by various spectrometry and electron microscopy techniques and devices, including ultraviolet–visible spectroscopy (UV/VIS), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS) attached to scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and the particle size distribution was analyzed by dynamic light scattering (DLS) technique. FTIR results identified the functional groups that are involved in and interact with biomolecules and nanoparticles surfaces through extensive screening on synthesized colloidal bimetallic NPs. The synthesized core – shell had mean size and monodispersity index (PDI) values of 0.223 and 61 nm, respectively. TEM micrographs clearly indicated that the Au NPs were coating and surrounding the Ag NPs and their size, distribution and shapes were homogeneous and uniform. Anticancer activity of the synthesized Ag@Au NPs was explored using MTT assay; the recorded cell viability was 500 μg/ml and the cytotoxicity (IC50) was 74.6 ± 7.43 µg/ml for HeLa cell line. This anticancer activity of the Ag@Au NPs opens the window wide for their use in cancer therapy and other biomedical applications.

Integration modeling and control of a 12-degree-of-freedom macro–micro dual parallel manipulator

Parallel manipulator systems with large workspace and high-accuracy positioning are attractive for a variety of accuracy engineering applications. In this article, a new 12-DOF macro–micro dual parallel manipulator is presented, which comprises a 6-PSU macro symmetrical parallel manipulator and a 6-SPS micro orthogonal parallel manipulator. This novel mechanism can not only realize a large range of movement but also accurate positioning. To achieve high-accuracy control, a macro–micro integrated model of the macro–micro dual parallel mechanism is proposed, including a mechanical system model and drive system model. Aiming at the trajectory planning for a multi-degree-of-freedom (DOF) manipulator, a smooth optimization trajectory planner for the 12-DOF macro–micro dual parallel manipulator is presented to realize smooth trajectory generation. A high-accuracy motion controller combining feedback and feedforward is developed based on the drive system model. Finally, the experiment well validates the correctness of the integrated model and motion control algorithm and reveals that the proposed mechanism is expected to be adopted into micro scale manipulations.

Manipulation of fish community structure effectively restores submerged aquatic vegetation in a shallow subtropical lake

Fish community manipulation and regulation has been largely overlooked as a mitigation strategy for restoring submerged aquatic vegetation (SAV) in shallow lakes of the middle and lower Yangtze River Basin (MLYRB). An in-situ fish exclusion experiment and a large-scale lake manipulation were conducted to test the hypothesis that the reasonable removal of benthivorous and herbivorous fish would facilitate the restoration and reconstruction of SAV in shallow lakes within the MLYRB. The in-situ exclusion experiment was conducted from April to October in 2017. Electrofishing was used to remove benthivorous and herbivorous fish from the exclosures. SAV were then artificially planted in the same pattern and density in both exclosures and adjacent open sites, and responses were measured for seven consecutive months. The mean percent coverage and biomass of SAV in the exclosures increased quickly and remained significantly higher than those in open sites over the duration of the experiment. Water quality also improved as turbidity, chlorophyll-a, total phosphorus and total nitrogen in the exclosures remained significantly lower than those in the open sites. After the in-situ experiment, a larger scale manipulation of fish in the entire submerged macrophyte zone (SMZ) was implemented from 2017 to 2020. After removing more than 2/3 of the benthivorous and herbivorous fish biomass by October 2020 in the SMZ, both the species richness and spatial coverage of SAV increased from 2 to 9 and from 1.7% to 32.2%, respectively. Our results provided clear evidence that fish are strong regulators of SAV productivity and that their reasonable removal facilitates ecological recovery. Therefore, we propose that fish community manipulation as implemented in this study be given more attention in addition to the reduction of external nutrient loading when designing projects to restore SAV in shallow lakes of the MLYRB.

Advanced Scanning Probe Nanolithography Using GaN Nanowires.

A fundamental understanding and advancement of nanopatterning and nanometrology are essential in the future development of nanotechnology, atomic scale manipulation, and quantum technology industries. Scanning probe-based patterning/imaging techniques have been attractive for many research groups to conduct their research in nanoscale device fabrication and nanotechnology mainly due to its cost-effective process; however, the current tip materials in these techniques suffer from poor durability, limited resolution, and relatively high fabrication costs. Here, we report on employing GaN nanowires as a robust semiconductor material in scanning probe lithography (SPL) and microscopy (SPM) with a relatively low-cost fabrication process and the capability to provide sub-10 nm lithography and atomic scale (<1 nm) patterning resolution in field-emission scanning probe lithography (FE-SPL) and scanning tunneling microscopy (STM), respectively. We demonstrate that GaN NWs are great candidates for advanced SPL and imaging that can provide atomic resolution imaging and sub-10 nm nanopatterning on different materials in both vacuum and ambient operations.

Initiating Research into Adapting Rural Hedging Techniques, Hedge Types, and Hedgerow Networks as Novel Urban Green Systems

This article seeks to initiate research into traditional rural hedging techniques, hedge types, and hedgerow networks for the purpose of their potential adaptation as urban green systems (UGS). The research involves three scales: (1) the plant scale and related manipulation techniques; (2) hedgerows and their context-specific types, ecosystem function, and ecosystem services; and (3) hedgerow networks as continuous green systems that characterize and support specific landscapes. This research required an interdisciplinary approach. The analysis was conducted by applying different modes of research including: (a) an extensive literature review, (b) analysis and systematization of hedge types and manipulation methods, (c) field experiments, (d) design experiments, and (e) examination of real-life projects that use hedges or hedging techniques as distinct design features. The initial research indicates that traditional hedges can be adapted to vitally contribute to UGS by providing a broad range of urban ecosystem services. Furthermore, the research includes initial proposals on future applications of adapted rural hedge types and techniques. On the larger scale, anticipated difficulties regarding implementation, such as land allocation in cities and resource-intensive planting, management, and maintenance, are discussed and further research questions are outlined.

Modification of modal characteristics in wakes of square cylinders with multi-scale porosity

Wake flows behind porous patches are complex and host several spatiotemporal features associated with multi-scale excitation. This is in stark contrast to flow past a square cylinder dominated by nonlinear energy cascade stemming from primary vortex shedding instability. In this study, we analyze wakes created by multi-scale patches containing three iterations while maintaining a constant plan porosity. The results are compared to flows obstructed by a square cylinder and a single-scale patch of uniformly distributed elements from the second iteration having the same footprint. Multi-scale porous patches show a protracted wake having a greater spanwise dimension compared to square cylinder. The characteristics are dependent on the arrangement of elements within the patch which affect the extent of bleed flow through the configuration. Besides, we use proper orthogonal decomposition and dynamic mode decomposition to elucidate instability mechanisms at different scales. Distributions of spatial modes reveal element-scale flow structures in the near-wake region with patch-scale turbulence further downstream. Our analysis confirms manipulation of characteristic scales and the associated high-energy events driven by the arrangement of elements within a given patch despite having the same plan porosity.

Increasing woody cover facilitates competitive exclusion of a savanna specialist

Anthropogenically modified systems tend to have homogenous wildlife communities. While this process is well documented, the mechanisms driving the convergence of species in human-modified systems are unclear. There are at least two compelling ecological explanations for the loss of specialized species in these settings; changes to the distribution and quality of resources (i.e. environmental conditions) and changes to competitive interactions. Without a better understanding of the mechanisms behind biotic homogenization, it is difficult to take appropriate conservation and management actions to maintain diverse communities.We investigated the roles of environmental conditions and competition in driving biotic homogenization in one of the world's most imperiled ecosystems; the longleaf pine (Pinus palustris) savanna of the American Southeast. Specifically, we investigated how generalist gray squirrels (Sciurus carolinensis) are replacing the more specialized fox squirrels (S. niger) in shrub and hardwood encroached Southeastern savannas. To test how changes to habitat and competition affect the specialist fox squirrel, we undertook a landscape scale manipulation. We experimentally manipulated competition by removing gray squirrels from closed-canopy patches embedded in longleaf pine savanna.Fox squirrels showed a strong response to gray squirrel removal, increasing their activity by 300% in the interior of closed-canopy patches. Fox squirrels in control patches did not use the interior of closed-canopy patches.Our experimental results support the hypothesis that biotic homogenization occurs when human-induced changes to the environment alter competitive interactions.

Atomic scale characterization of three-dimensional structure, magnetic properties and dynamic evolutions of materials by transmission electron microscopy

Atomic scale characterization and manipulation is one of the physical bottlenecks, which needs to be broken when realizing atom manufacturing. The aberration-corrected transmission electron microscopy (TEM) is a powerful tool for structural characterization due to its exceptional spatial resolution. Therefore, it is very crucial to co-characterize atomic-scale three-dimensional structure and properties of atomic manufacturing materials by using TEM, which allows us to further understand the physics mechanism of atomic manipulation of materials. Nano-clusters and nanoparticles are two of the main objects in the studies of atomic manufacturing materials and devices, and possess rich physical and chemical properties and high manoeuverability. In this paper, we summarize the recent progress of quantitatively determining three-dimensional structures and magnetic properties of nanocluster, nanoparticles and nanograins, as well as their dynamic evolutions under the working conditions. The methodological breakthrough and development of electron microscopy techniques provide a solid foundation for precisely controlling atomic manufacturing materials.

Effects of nutrient enrichments on oligotrophic phytoplankton communities: a mesocosm experiment near Hawai‘i, USA

A large-volume mesocosm-based nutrient perturbation experiment was conducted off the island of Hawai‘i, USA, to investigate the response of surface ocean phytoplankton communities to the addition of macronutrients, trace metals, and vitamins and to assess the feasibility of using mesocosms in the open ocean. Three free-drifting mesocosms (~60 m3) were deployed: one mesocosm served as a control (no nutrient amendments); a second (termed +P) was amended with nitrate (N), silicate (Si), phosphate (P), and a trace metal + vitamin mixture; and a third (termed -P) was amended with N, Si, and a trace metal + vitamin mixture but no P. These mesocosms were unreplicated due to logistical constraints and hence differences between treatments are qualitative. After 6 d, the largest response of the phytoplankton community was observed in the +P mesocosm, where chlorophyll a and 14C-based primary production were 2-3× greater than in the -P mesocosm and 4-6× greater than in the control. Comparison between mesocosm and ‘microcosm’ incubations (20 l) revealed differences in the magnitude and timing of production and marked differences in community structure with a reduced response of diatoms in microcosm treatments. Notably, we also observed pronounced declines in Prochlorococcus populations in all treatments, although these were greater in microcosms (up to 99%). Overall, this study confirmed the feasibility of deploying free-drifting mesocosms in the open ocean as a potentially powerful tool to investigate ecological impacts of nutrient perturbations and constitutes a valuable first step towards scaling plankton manipulation experiments.

Cover-Lossless Robust Image Watermarking Against Geometric Deformations.

Cover-lossless robust watermarking is a new research issue in the information hiding community, which can restore the cover image completely in case of no attacks. Most countermeasures proposed in the literature usually focus on additive noise-like manipulations such as JPEG compression, low-pass filtering and Gaussian additive noise, but few are resistant to challenging geometric deformations such as rotation and scaling. The main reason is that in the existing cover-lossless robust watermarking algorithms, those exploited robust features are related to the pixel position. In this article, we present a new cover-lossless robust image watermarking method by efficiently embedding a watermark into low-order Zernike moments and reversibly hiding the distortion due to the robust watermark as the compensation information for restoration of the cover image. The amplitude of the exploited low-order Zernike moments are: 1) mathematically invariant to scaling the size of an image and rotation with any angle; and 2) robust to interpolation errors during geometric transformations, and those common image processing operations. To reduce the compensation information, the robust watermarking process is elaborately and luminously designed by using the quantized error, the watermarked error and the rounded error to represent the difference between the original and the robust watermarked image. As a result, a cover-lossless robust watermarking system against geometric deformations is achieved with good performance. Experimental results show that the proposed robust watermarking method can effectively reduce the compensation information, and the new cover-lossless robust watermarking system provides strong robustness to those content-preserving manipulations including scaling, rotation, JPEG compression and other noise-like manipulations. In case of no attacks, the cover image can be recovered without any loss.