bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biocompatibility of platinum-based bulk metallic glass in orthopedic applications
Authors: Loye Ayomiposi M , Kwon Hyuk-Kwon , Dellal David , Ojeda Rodrigo , Lee Sangmin , Davis Rose , Nagle Natalie , Doukas Panagiotis G , Schroers Jan , Lee Francis Y , Kyriakides Themis R 
Published: April 2021

Abstract
Bulk metallic glasses (BMGs) are a class of amorphous metals that exhibit high strength, ductility paired with wear and corrosion resistance. These properties suggest that they could serve as an alternative to conventional metallic implants that suffer wear and failure. In the present study, we investigated Platinum (Pt)-BMG biocompatibility in bone applications. Specifically, we investigated osteoclast formation on flat and nanopatterned Pt57.5Cu14.7Ni5.3P22.5 (atomic percent) as well as titanium (control). Specifically, receptor activator of NF-κB (RANK) ligand-induced murine bone marrow derived mononuclear cell fusion was measured on multiple nanopatterns and was found to be reduced on nanorods (80 and 200 nm in diameter) and was associated with reduced tartrate-resistant acid phosphatase (TRAP) and matrix metalloproteinase (MMP9) expression. Evaluation of mesenchymal stem cell (MSC) to osteoblast differentiation on nanopatterned Pt-BMG showed significant reduction in comparison to flat, suggesting that further exploration of nanopatterns is required to have simultaneous induction of osteoblasts and inhibition of osteoclasts.In vivo studies were also pursued to evaluate the biocompatibility of Pt-BMG in comparison to titanium. Rods of each material were implanted in the femurs of mice and evaluated by x-ray, mechanical testing, micro-computed tomography (micro-CT), and histological analysis. Overall, Pt-BMG showed similar biocompatibility with titanium suggesting that it has the potential to improve outcomes by further processing at the nanoscale.
Integrated assessment model diagnostics: key indicators and model evolution
Authors: Harmsen Mathijs , Kriegler Elmar , van Vuuren Detlef P , van der Wijst Kaj-Ivar , Luderer Gunnar , Cui Ryna , Dessens Olivier , Drouet Laurent , Emmerling Johannes , Morris Jennifer Faye , Fosse Florian , Fragkiadakis Dimitris , Fragkiadakis Kostas , Fragkos Panagiotis , Fricko Oliver , Fujimori Shinichiro , Gernaat David , Guivarch Céline , Iyer Gokul , Karkatsoulis Panagiotis , Keppo Ilkka , Keramidas Kimon , Köberle Alexandre , Kolp Peter , Krey Volker , Krüger Christoph , Leblanc Florian , Mittal Shivika , Paltsev Sergey , Rochedo Pedro , van Ruijven Bas J , Sands Ronald D , Sano Fuminori , Strefler Jessica , Arroyo Eveline Vasquez , Wada Kenichi , Zakeri Behnam 
Published: April 2021

Abstract
Integrated assessment models (IAMs) form a prime tool in informing about climate mitigation strategies. Diagnostic indicators that allow comparison across these models can help describe and explain differences in model projections. This increases transparency and comparability. Earlier, the IAM community has developed an approach to diagnose models (Kriegler (2015 Technol. Forecast. Soc. Change
90 45–61)). Here we build on this, by proposing a selected set of well-defined indicators as a community standard, to systematically and routinely assess IAM behaviour, similar to metrics used for other modeling communities such as climate models. These indicators are the relative abatement index, emission reduction type index, inertia timescale, fossil fuel reduction, transformation index and cost per abatement value. We apply the approach to 17 IAMs, assessing both older as well as their latest versions, as applied in the IPCC 6th Assessment Report. The study shows that the approach can be easily applied and used to indentify key differences between models and model versions. Moreover, we demonstrate that this comparison helps to link model behavior to model characteristics and assumptions. We show that together, the set of six indicators can provide useful indication of the main traits of the model and can roughly indicate the general model behavior. The results also show that there is often a considerable spread across the models. Interestingly, the diagnostic values often change for different model versions, but there does not seem to be a distinct trend.
Feynman-type representation of the scattering matrix on the line via a discrete-time quantum walk
Authors: Higuchi Kenta 
Published: April 2021

Abstract
The aim of this article is to relate the discrete quantum walk on

Z

with the continuous Schrödinger operator on

R

in the scattering problem. Each point of

Z

is associated with a barrier of the potential, and the coin operator of the quantum walk is determined by the transfer matrix between bases of WKB solutions on the classically allowed regions of both sides of the barrier. This correspondence enables us to represent each entry of the scattering matrix of the Schrödinger operator as a countable sum of probability amplitudes associated with the paths of the quantum walker. In particular, the barrier-top scattering corresponds to the Hadamard walk in the semiclassical limit.
Gel’fand–Yaglom type equations for calculating fluctuations around instantons in stochastic systems
Authors: Schorlepp Timo , Grafke Tobias , Grauer Rainer 
Published: April 2021

Abstract
In recent years, instanton calculus has successfully been employed to estimate tail probabilities of rare events in various stochastic dynamical systems. Without further corrections, however, these estimates can only capture the exponential scaling. In this paper, we derive a general, closed form expression for the leading prefactor contribution of the fluctuations around the instanton trajectory for the computation of probability density functions of general observables. The key technique is applying the Gel’fand–Yaglom recursive evaluation method to the suitably discretized Gaussian path integral of the fluctuations, in order to obtain matrix evolution equations that yield the fluctuation determinant. We demonstrate agreement between these predictions and direct sampling for examples motivated from turbulence theory.
A spatial prototype of natural ventilation in underground public spaces combining courtyard with wind tower
Authors: Wen Yueming , Leng Jiawei 
Published: April 2021

Abstract
Ventilation is the basis of controlling thermal comfort and air quality in underground spaces. Natural ventilation based on spatial designs can introduce wind, light, and scenery to improve environmental health and spatial experience, and reduce health risks and energy consumption of mechanical ventilation. This paper proposes a spatial prototype that combines courtyard with wind tower, two common spatial forms connecting aboveground and underground, and can provide effective natural ventilation to underground public spaces. Computational fluid dynamics simulations and genetic optimization were conducted in the common architectural software Rhinoceros and Grasshopper. First, spatial defects are identified and optimized by analysing the simulation results. Then, geometric variables of the spatial form that obviously affect the ventilation performance were selected and automatically optimized with the target of air volume per hour. Finally, three key issues for natural ventilation of underground public spaces are discussed including human comfort, air distribution, and ventilation reliability. This paper explores the coupling between the spatial form and ventilation performance of underground public spaces, which not only alleviates the potential conflict between energy saving and environmental health, but also provides an integrated design pattern to create more open, flexible, natural and sustainable underground spaces.
Ryazanskaya Transit Oriented Development
Authors: Ceccotto Arch. Stefano , Msaud  
Published: April 2021

Abstract
The Ryazanskaya Transit Oriented Development (TOD) is a large intervention included in Moscow’s 2030 urban planning, realizing a transit hub, commercial / retail spaces, an office tower and two metro/rail terminal buildings, to be built around a public park where ground transportation is also located. Within this master plan, the Terminal 2 integrates an underground transit hall to provide access for three mass transportation lines merging at Ryazanskaya TOD. Such urban-scale complex required international best practice architectural solutions, particularly focused onto the relationship between underground spaces and above-ground structures. The Ryazanskaya project is a case study useful to understand and explain the typical TOD urban design methodology, as a part of a large city-making process originated by the design of underground infrastructures and concluded with the architectural design of a strategic asset for the contemporary metropolis.
Study on Implementation Strategies of Multifunctional Linear Underground Space: A Case Study in Beijing’s sub-center
Authors: Wei Meng , Chen Pengbo , Su Yunlong 
Published: April 2021

Abstract
DEVELOPMENT CONTROL PLAN FOR THE SUB-CENTER OF BEIJING (2016-2035) says, a facility service ring with complex functions, balanced layout and integrated above ground and underground space will be constructed, which is efficient integrated underground infrastructure, with a total length of about 36.5 kilometers, coordinating the construction of circular underground systems such as subway, utility tunnel, urban underground logistics, and automatic garbage collection and transfer, and jointly building municipal facilities such as hidden municipal facilities, multi-level rainwater control and utilization facilities, emergency evacuation facilities, underground peak-storage and peak-regulation facilities. Aiming at the feasibility of the project, though analyzing in detail the present situation and planning of land use, pipeline and underground space along the ring and surrounding areas, and fully sorting out the functions and space demand characteristics of the major systems in the facility service ring, deeply explore the advanced technologies such as urban underground logistics and automatic garbage collection and transfer, and propose the inclusive and multifunctional underground space implementation strategies, for the meticulous use of underground space.
The main characteristics of urban underground space regulatory plan from the perspective of China’s spatial planning: A practice in Beijing Sub-Center
Authors: Chao Gao , Kejie Wu , Qin Chen 
Published: April 2021

Abstract
In order to better solve the new problems encountered in the national development, China is gradually establishing a new national territory spatial planning system. It can implement the requirements of whole-area and multi-element control of land and space. Underground space planning is a special planning in the new spatial planning system. We will explore how to scientifically and reasonably prepare underground space planning. Combined with the planning practice of Beijing and Sub-Center, we propose that the underground space planning system should be further improved, especially at the regulatory planning level. It can not only refine the master planning requirements of underground space, but also effectively guide the detailed planning and project construction of underground space. This paper attempts to put forward the main characteristics of underground space regulatory planning, hoping to provide reference for other cities’ underground space planning. The first is ecological priority and limited utilization. Detailed geological survey is the basis of underground space planning. In the Sub-Center, we evaluated the requirements of geological ecological protection and the impact of geological disasters, and delineated the three-dimensional utilization boundary of underground space and the influence scope of geological disasters. The second is the improvement of space management and space vitality. We explore the allocation method of underground space covered area, and divide the covered area into each construction site, giving priority to the key areas such as Universal Studios and metro station areas. The third is multi-dimensional utilization and planning integration. The underground facilities are planned in depth and intensively. The plan puts forward detailed in-depth layout guidance, focusing on the construction of Facility Service Ring, and coordinating the intensive construction of underground tunnels, metro and underground municipal facilities. The fourth is to encourage the application of new technologies. The planning will reserve sufficient space for future development, such as the construction of underground logistics, multistage rainwater collection and underground heat utilization in the Sub-Center.
The onset of underground urban planning in Flanders
Authors: Debrock S 
Published: April 2021

Abstract
Urban underground space (UUS) can be an effective means to meet the needs of the cities and simultaneously deal with societal and urban challenges. However, in Flanders the use of UUS remains to be one of the most forgotten urban assets and is characterised by a haphazard, uncoordinated ‘last resort’ practice detrimental to sustainable development. In a search for new possibilities for qualitative densification the Flemish Government instigated a policy exploration to investigate if efficient use of the UUS could be a possible solution for lowering the daily land take. This paper describes the process and content of the policy exploration and sets out policy recommendations. The paper concludes that although the merits of UUS have been thoroughly recognized and the significance of the subsurface in urban renewal is clear, the efficient use of UUS in Flanders and the fulfilment of Flemish policy objectives cannot be guaranteed without the development of UUS policy and the integration of UUS policy in the overall Flemish urban planning system. The research finds that a clear definition of planning factors for the use of UUS is necessary to support the transition from using the UUS to integration of the UUS into wider urban planning processes. It puts forward the need for a comprehensive list of planning factors, gathered in a holistic, integrated manner, necessary to transition from UUS projects to UUS planning.
Spatial accessibility and functional layout impacts on urban underground space development: a case study of Shanghai
Authors: Dong Yun-Hao , Peng Fang-Le , Xing Xiao , Wu Xiao-Lei 
Published: April 2021

Abstract
Over the past decade, China’s megacities such as Shanghai and Beijing have witnessed great progress in their metro networks. With the rapid development of metro system, urban underground space (UUS) in China has been widely utilized in a systematic manner, following the principles of transit-oriented development. A comprehensive understanding of the impacts of the built environment on UUS is doubtlessly conducive to the high-quality and sustainable urban development. However, there are fewer researches conducted to study the impacts on UUS compared with those studies focusing on ground level space. Moreover, quantitative researches using multi-source big data on underground space are limited, which makes it hard to reveal the development regulation with high-precision at a large scale. This paper aims to study the impacts of spatial accessibility and functional layout on UUS. Shanghai, as one of the most prosperous megacities in China with well-developed underground space, was selected as the case study. In this paper, open data from Open Street Map and Point of Interest (POI) in AMAP was adopted. Indices such as integration (index of space syntax) of metro line, road length, road density, POI density, and entropy of POI were chosen to reflect the spatial accessibility and functional layout. Underground POI (UPOI) density was set as a proxy of UUS development intensity. A quantitative analysis using multiple linear regression model was conducted. The results showed that both two kinds of indices strongly correlated to the underground space development, whereas the influences of selected indices on UUS were different. At last, the characteristics of UUS in Shanghai and further development strategies were discussed, which provided a perspective of smart growth for planners, designers and authorities.
Deformation characteristics of sedimentary rock due to continuous changes of moisture content in wetting process
Authors: Togashi Yota , Imano Takanobu , Osada Masahiko 
Published: April 2021

Abstract
In recent years, the number of cases where tunnels are constructed in sedimentary rock layers has increased. It is essential to investigate the deformation characteristics of sedimentary rocks for predicting tunnel deformation. The mechanical properties of sedimentary rocks are widely varied due to moisture content. The rocks are dried by tunnel excavation and wetted by groundwater gushing or backfilling. It is necessary to grasp the changes of deformation characteristics of sedimentary rocks due to moisture changes. In this study, soaking tests were conducted on Neogene period Japanese tuff sampled at Utsunomiya, Japan. In the test, the cylindrical tuff specimens are air dried by over 240 hours at first. Then the tuff specimens are taken in pure water with measuring deformations in detail. There are no effective stress increases by soaking and only uniform matric suction are acted on the specimen without any restraints. The results demonstrated that strain tensor was reached to stable state for 2 - 3 days, and the value of the normal strain perpendicular to the bedding plane is greater than the other normal components and shear strains are also observed in both cases. Although the orientation of the maximum principal strain is in the near of the bedding orientation at the initial dry state, the orientation are suddenly rotated to the normal orientation of the bedding plane. It means that the principal orientation of anisotropy are rotated due to continuous moisture changes.
Effects of the underground discharge channel/reservoir for small urban rivers in the Tokyo area
Authors: Nakamura H , Oosawa M 
Published: April 2021

Abstract
In the midst of global climate change, a large typhoon has hit Japan and unprecedented heavy rainfall is occurring. In large cities in Japan, underground discharge channels and underground regulating reservoirs are being developed to improve the flood control safety.
In this paper, we confirm the flood reduction effect of these underground facilities against the rainfall generated by Typhoon Hagibis in the Tokyo area in 2019.
In addition, the advantages of underground regulating reservoirs in the metropolitan area are discussed from two aspects: cost and land acquisition. It is confirmed that the underground reservoir type has remarkable advantages in both aspects.
Geothermal energy in urban planning
Authors: Akhmetzyanov Anvar , Bobylev Nikolai , Wende Wolfgang 
Published: April 2021

Abstract
Geothermal energy is a collective term referring to Earth heat extraction and use of the ground capacity to absorb and store thermal energy to supply heat or cold. Thermal ground exchange or shallow geothermal energy has been increasingly used in the housing sector to sustain comfortable room temperature. Increasing utilization of geothermal energy, particularly in urban areas, requires integration into urban planning processes. The question of subsurface planning, or underground space integration into land-use planning, or three-dimensional planning has been an emerging research theme in this decade. This paper will focus on specific issues that pertain to geothermal energy use in land use planning in urban areas. These issues include (1) holistic vision of underground space as a resource, (2) geothermal energy technologies in terms of using space, (3) multiple users and installations of heat pumps and their interaction, (4) possible conflicts and interference with other subsurface users and functions, (5) demand and suitability of geothermal use in housing, (6) urban densities and geothermal energy feasible use, (7) and general principles of urban geothermal land use planning. A feasibility case study of using heat pumps to provide heating for a typical historic residential multifamily building in the Petrogradsky district of the city of St. Petersburg, Russia is given.
Computer modeling analysis of METRO ticket gates impact to evacuation procedures
Authors: Rebecca Papakonstantinou , Anastasios Kallianiotis , Despina Papakonstantinou , Maria Menegaki 
Published: April 2021

Abstract
Subway rail system is considered the best choice for big cities to solve surface transportation problems in terms of congestion, efficiency, and speed. The increasing use of these facilities by more and more passengers has made vital the need to ensure high safety standards. The effective structure of the evacuation plan in an emergency event is essential. A critical factor for a successful evacuation is the proper functioning of the egress paths that must be clear of any obstacles.
To ensure the passengers’ proof-of-fare (POF) public transport organizations have installed ticket validation machines proportionally in the facilities. In Athens METRO system, ticket gates providing automatic fare collection have replaced these ticket validation machines. Both POF systems may be considered as egress path obstructions that need to be taken into account in the initial evacuation plan design, since these POF installations provide different available width on the evacuation paths.
The paper investigates the impact of prior ticket validator and modern automatic fare collector machines on evacuation procedures in Athens METRO stations. The impact evaluation is based on three factors: i) total evacuation time, ii) time spent in queues (overcrowding effect) and iii) egress path flow rate, evacuation obstruction, human behavior.
Parameters that affect tenability conditions during fire emergency in metro tunnels
Authors: Papakonstantinou D , Kallianiotis A , Benardos A 
Published: April 2021

Abstract
Underground spaces are characterized by special conditions and complexity, as well as by severe consequences in the event of an accident. Although the frequency of fire accidents in tunnels or metro stations is low, in worst cases they may lead to severe fatalities and damages. In order to have a more accurate prediction of fire impacts, most safety standards enforced worldwide suggest the development of special risk analyses. This needs to be made having in mind fire characteristics, geometrical and ventilation parameters so as to have an accurate view of the thermal and smoke propagation within the underground space. In this paper a parametric analysis is carried out, varying input values, crucial for fire risk analysis, like fire curve and heat release rate maximum (HRRmax), as well as ventilation and tunnel geometry. Key factors like visibility conditions, temperature and CO concentration are recorded through the fire dynamic simulation (FDS), in order to determine the conditions inside the metro tunnel. Furthermore, the fractional effective dose (FED) that occupants might receive in a period of time, in different positions inside the tunnel, is calculated. Based on the above, detailed data on the prevailing conditions are gathered and conclusions can be drawn regarding the influence of each parameter’s evolution on the tenability conditions inside the tunnel. Hence, the analysis can illuminate key issues to consider for performing an accurate risk analysis in an underground environment.