Slow Route Research Articles

Exploring the frequency of public transport use among adolescents: a study in Yogyakarta, Indonesia

Despite the establishment of the Trans Jogja Bus (TJB) service in 2008 as a solution for the problems with conventional bus services in numerous Indonesian cities, public transport ridership in Yogyakarta has remained somewhat stagnant. On TJB, adolescents comprise the dominant demographic group. This study investigated the factors influencing the frequency of TJB use, including sociodemographic and household characteristics, the built environment, perception of TJB performance, pro-environmental attitudes, and health behaviors among adolescents aged 13 to 15 years old. A face-to-face interview survey was conducted to collect data on 774 adolescents. This study used both an ordered logit model in which the perception variables were set as the independent variables and an ordered hybrid choice model, which incorporated the latent variables on adolescents’ perception of TJB use. The model results reveal that age, the number of adults in a household, car ownership, and the distance to school correlate with the use of TJB. We found that positive perceptions of TJB such as safety, security, comfort, and low cost substantially influence the use of TJB compared with negative perceptions such as infrequent buses, scarce bus stops, and slow meandering bus routes. With this in mind, perceived benefits such as reduced congestion, improved health, and environmental advantages have no significant influence on the frequency of TJB use. The model results emphasize the need to improve route efficiency, enhance existing performance, and promote TJB as a healthy, green, and sustainable travel mode.

Dry Processing and Recycling of Thick Nacre–Mimetic Nanocomposites

AbstractBioinspired nanocomposites with high levels of reinforcement hold great promise for future, green lightweight, and functional engineering materials, but they suffer from slow, tedious, and nonscalable preparation routes, that typically only lead to very thin films. A rapid and facile dry powder processing technique is introduced to generate bioinspired nanocomposite materials at high fractions of reinforcements (50 wt%) and with millimeter scale thickness. The process uses powder drying of vitrimer‐coated nanoplatelets (nanoclay and MXene) from aqueous solution and subsequent hot‐pressing. As a method of choice in industrial lightweight composite materials engineering, hot‐pressing underscores a high potential to translate this approach to actual products. The use of the vitrimer chemistry with temperature‐activated bond shuffling is important to facilitate smooth integration into the nanocomposite design, leading to layered nacre‐inspired nanocomposites with nanoscale hard/soft order traced by X‐ray diffraction and excellent mechanical properties investigated using flexural tests. Recycling by grinding and hot‐pressing is possible without property loss. The compatibility with existing composite processing techniques, scalable thickness and dimensions, and recyclability open considerable opportunities for translating bioinspired nanocomposites to real‐life applications.

Operando Monitoring the Insulator-Metal Transition of LiCoO2.

LiCoO2 (LCO) is one of the most-widely used cathode active materials for Li-ion batteries. Even though the material undergoes an electronic two-phase transition upon Li-ion cell charging, LCO exhibits competitive performance in terms of rate capability. Herein the insulator-metal transition of LCO is investigated by operando Raman spectroscopy complemented with DFT calculations and a developed sampling volume model. We confirm the presence of a Mott insulator α-phase at dilute Li-vacancy concentrations (x > 0.87, x in LixCoO2), which gradually transitions to primarily a metallic β-phase as x approaches 0.75. In addition, we find that the charge-discharge intensity trends of LCO Raman-active bands exhibit a characteristic hysteresis, which, unexpectedly, narrows at higher cycling rates. When comparing these trends to our numerical model of laser penetration into a spatially heterogeneous particle we provide compelling evidence that the insulator-metal transition of LCO follows a two-phase route at very low cycling rates, which is suppressed in favor of a solid-solution route at rates above 20 mA/gLCO (∼C/10). The observations explain why LCO exhibits competitive rate capabilities despite being observed to undergo an intuitively slow two-phase transition route: a kinetically faster solid-solution transition route becomes available when the active material is cycled at rates >C/10. Operando Raman spectroscopy combined with sample volume modeling and DFT calculations is shown to provide unique insights into fundamental processes governing the performance of state-of-the-art cathode materials for Li-ion batteries.

Screening of slow pyrolysis routes for maximum biofuel production from Syzygium malaccense biomass by TGA-FSD and chemometric tools

The dependence of oil and its consequent commercial fluctuation make researchers to seek viable alternatives for their gradual replacement. The present work aims to evaluate the production of biofuels from the slow pyrolysis of the Syzygium malaccense biomass (Malay Apple) through thermogravimetric analysis (TGA-DTG), Fraser-Suzuki deconvolution and chemometric tools of multivariate analysis. Three chemical treatments (sodium hydroxide, sulfuric acid and phosphoric acid) were evaluated, as well as the variation in the heating rate and the consequent effects on the pyrolysis of biomass for the production of biofuels, totaling 16 pyrolysis routes (including the use of biomass no treatment). In the obtained data, multivariate analysis tools were used, looking for groups that presented favorable characteristics for the production of quality biofuels. Heatmap, k-means and SOM analysis indicated the routes that use phosphoric acid treatment and heating rates of 10 or 15 °C/min (Jap10 and Jap15, respectively) as relevant, because they have low lignin contents and high gaseous cellulose and hemicellulose contents.

Taking the slow route to decarbonisation? Developing climate governance for international transport

Despite their significant, growing contribution to global emissions, international aviation and shipping have avoided a significant climate governance response until recently. This paper outlines the urgent need for, but major barriers to, decarbonisation of these industries, including various market failures and sensitivities over restraining demand. The need and potential for international governance to address these issues is seen to vary across aviation and shipping, given different industry structures and characteristics. A range of relevant inter- and transnational governance institutions is highlighted and an assessment of their overall adequacy offered. With a 2018 commitment to significant emission reduction, maritime governance effort has progressed further, although significant implementation challenges remain. Meanwhile aviation-related commitments rely more on out-of-sector offsets. Options for enhancing governance for decarbonisation are outlined, highlighting the importance of, inter alia, coordination between the UNFCCC and sectoral bodies, mechanisms to finance R&D and incentivise investment, and openness in key decision-making fora.

The coal conundrum

The application to build a new coal mine in Cumbria highlights steel’s slow route to carbon neutrality

State-of-the-Art Char Production with a Focus on Bark Feedstocks: Processes, Design, and Applications

In recent years, there has been a surge of interest in char production from lignocellulosic biomass due to the fact of char’s interesting technological properties. Global char production in 2019 reached 53.6 million tons. Barks are among the most important and understudied lignocellulosic feedstocks that have a large potential for exploitation, given bark global production which is estimated to be as high as 400 million cubic meters per year. Chars can be produced from barks; however, in order to obtain the desired char yields and for simulation of the pyrolysis process, it is important to understand the differences between barks and woods and other lignocellulosic materials in addition to selecting a proper thermochemical method for bark-based char production. In this state-of-the-art review, after analyzing the main char production methods, barks were characterized for their chemical composition and compared with other important lignocellulosic materials. Following these steps, previous bark-based char production studies were analyzed, and different barks and process types were evaluated for the first time to guide future char production process designs based on bark feedstock. The dry and wet pyrolysis and gasification results of barks revealed that application of different particle sizes, heating rates, and solid residence times resulted in highly variable char yields between the temperature range of 220 °C and 600 °C. Bark-based char production should be primarily performed via a slow pyrolysis route, considering the superior surface properties of slow pyrolysis chars.

SMSEI‐SDN: A Suppression Method of Security Incident Impact for the Inter‐Domain Routing System Based on Software‐Defined Networking

Security incidents such as natural disasters and power outages can cause inter‐domain routing system regional failures, significantly impact the Internet’s safety. Reducing the impact of security incidents is essential for maintaining the stability of the Internet. One of the major impacts of security incidents is that many UPDATE messages will generate, which may easily cause network oscillations. This paper presents the UPDATE messages analysis during the six security incidents and finds that many duplicates and invalid messages are the leading cause of network instability. To effectively process these UPDATE messages, this paper proposes an UPDATE message preprocessing algorithm by analyzing the UPDATE operating mechanism to remove duplicate and invalid messages. Aiming at the problem of slow route search in existing route update methods using software‐defined networking (SDN), this paper designs a RIB hierarchical structure for multi‐level retrieval and proposes SMSEI‐SDN combination with current route update strategies. Experimental results show that when a security incident occurs, by removing duplicate and invalid messages, SMSEI‐SDN can reduce the total number of messages by an average of 19% and a maximum of 34.9% within the 60 s of caching time. Besides, SMSEI‐SDN can reduce the routing update time by more than 99.98% compared to existing methods. This work provides insights for network operators and researchers interested in security incident impact suppression in the inter‐domain routing system.

Effect of terbium and silver co-doping on the enhancement of photoluminescence in CaSO4 phosphors

Abstract In this work, the photoluminescence properties of CaSO4 crystals co-doped with terbium and silver from silver oxide or silver nanoparticles (NPs) in different concentrations are investigated. Phosphors are obtained by means of a slow evaporation route and calcined at 600 °C for 1 h. X-ray diffraction analysis shows the formation of a single-phase anhydrite structure with orthorhombic symmetry. The photoluminescence properties are investigated using vacuum ultraviolet, ultraviolet and X-ray excitation. All luminescent measurements reveal the characteristic emissions of Tb3+. The analyses using excitation with ultraviolet light show that the Ag NPs are able to generate structural defects more satisfactorily compared to CaSO4:Tb with silver oxide. We also observe that higher concentrations of Ag increase the Tb3+ emission intensity, while higher concentrations of Ag NPs decrease it. The good stability of CaSO4 results in an efficient energy transfer from the host lattice to the activator under X-ray excitation, with the NPs contributing to the increase in luminescent intensity. Investigation of the terbium valence in the CaSO4 host shows a complete reduction of the Tb4+ present in Tb4O7 to Tb3+, as indicated by the X-ray absorption near edge structure. The vacuum ultraviolet excitation spectra reveal three broad bands, attributed to the charge-transfer excitations within SO42− complexes and to the 4f8 → 4f75d1 transitions on Tb3+. Our results also reveal that silver particles are responsible for generating deeper capture centers.

Colloidal monolayers with cell-like tessellations via interface assisted evaporative assembly

Evaporating sessile drops containing surface active colloids is a promising route to self-assemble two-dimensional nanostructures. The standard protocol is to first self-assemble surface active nanoscale particles at the water-vapour interface and subsequently transfer it on to a solid surface. Colloidal monolayers with very few morphologies have been fabricated, exploiting this bottom-up self-assembly technique. However, the evaporation kinetics under controlled humidity conditions may dramatically alter the microstructure of self-assembled colloidal monolayers at the liquid-vapor interface and that on the solid surfaces, an aspect that has not been fully addressed in the prior studies. To this end, we present an experimental study of evaporation driven self-assembly of soft poly(N-isopropylacrylamide) (pNIPAM) microgel particles loaded in a sessile drop. The surface-active microgel particles spontaneously populate the water-vapour interface facilitating the suppression of the coffee-ring effect and the formation of monolayer stains. The role of evaporation kinetics under controlled humidity conditions on the colloid's microstructure adsorbed to the solvent-air interface and on the morphology of the colloidal monolayer transferred onto the solid surface are studied in detail. The formation of particle-free and particle-rich regions at the water-vapor interface is observed for sessile drops evaporated under saturated humidity conditions. We show that the evaporation induced shrinkage of the interface area and the enhancement of the areal density of microgel particles adsorbed onto the interface leads to a restructuring of the particle-laden interface. The rearrangement of microgel particles along the water-vapor interface resembling the de-wetting assisted patterns is transferred to the solid substrate upon complete evaporation of the solvent. The microgel particles in the deposit assemble into domains with enhanced crystalline order. The evolution of Voronoi entropy across the monolayer deposit patterns obtained by the standard and slow evaporation routes are presented.

Atomistic simulation and spectroscopic study of the [formula omitted] doped [formula omitted] crystal

The CaSO4:Eu3+ has been prepared by the slow evaporation route with different concentrations of the luminescent ion, characterized by XRD and emission spectra techniques and studied by atomistic simulation and crystal field theory. The lattice parameters were obtained with a new set of potentials which is proving to be more appropriate to simulate the lattice parameters and the local Eu3+ luminescent site than those published elsewhere. The Simple Overlap Model (SOM) was applied in the frame of the Method of Equivalent Nearest Neighbours (MENN) in order to predict the charge factors devoted do the Eu–O bond and the 7F1 energy sub-levels through the crystal field parameters. The central ion charge (gEu) was predicted by the Batista–Longo Improved Model (BLIM). Our calculations indicated that the Eu3+ prefers the Ca2+ site compensated by calcium vacancy or interstitial oxygen. Using the four simulated structures the 7F1 Stark levels were satisfactory reproduced. Thus, based on the simulations and the number of lines exhibited in the emission spectra, one has a strong indication that the Eu ion occupies a distorted local symmetry which is a combination of the D2 and C2v point groups.

TL/OSL signal of CaSO4:Eu,Ag samples produced by variations of the slow evaporation route

The aim of this work was to produce crystals of CaSO4 doped with europium (Eu) and silver (Ag) nanoparticles, by means of three different preparation routes, and to study their applicability in radiation dosimetry by the TL and OSL techniques. The crystals were produced by variations of the slow evaporation route. Samples of CaSO4:Eu,Ag(a) were obtained using europium oxide and silver particles as dopants. For the growth of the crystals of CaSO4:Eu,Ag(b), silver was incorporated in nitrate form. CaSO4:Eu,Ag(c) phosphorus were synthetized mixing europium oxide in a colloidal suspension of silver nanoparticles. Optical characterization confirmed the presence of Eu3+/Eu2+ in the crystal matrix. Dosimetric characteristics were evaluated after the exposure of the samples to a90Sr/90Y source. The CaSO4:Eu,Ag(a) and CaSO4:Eu,Ag(b) composites presented the most intense signals, the lowest detectable doses, and showed a linear and reproducible dose response, but the CaSO4:Eu,Ag(a) samples showed the best potential for application in TL/OSL dosimetry.

Structural, optical and dosimetric characterization of CaSO4:Tb, CaSO4:Tb, Ag and CaSO4:Tb,Ag(NP)

The proposal of this work was to produce and characterize CaSO4 crystals doped with terbium and silver nanoparticles for use in thermoluminescent (TL) and optically stimulated luminescent (OSL) dosimetry. The crystalline structure, morphology and optical properties of the phosphors were characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, and photoluminescence. The viability of the slow evaporation route used in the production was confirmed. The silver nanoparticles (Ag(NPs)) were prepared by the method proposed by Lee and Meisel and characterized by XRD and visible absorption spectroscopy (UV–Vis). The composites were obtained from the addition of Teflon to the phosphors. Through the analyses, it was observed that the presence of silver nanoparticles slightly increases the intensity of the emission of the phosphor and shifts the dosimetric TL peak from 185 °C to 310 °C, at a heating rate of 10 °C/s. The samples presented a typical exponential OSL decay curve with a very slow component (τ3 ≥ 152 s) that indicates that the traps have a low photoionization cross-section for blue LEDs. CaSO4:Tb,Ag(NP) presented a higher sensitivity to radiation than CaSO4:Tb,Ag. The lowest detectable dose (LDD) and the fading of the TL signal of the composites were also evaluated. All samples presented a luminescent signal reproducible and linear, with TL and OSL responses proportional to the absorbed doses in the range of 169 mGy to 10 Gy.

Pathways of the water masses exiting the Labrador Sea: The importance of boundary–interior exchanges

The water masses exiting the Labrador Sea, and in particular the dense water mass formed by convection (i.e. Labrador Sea Water, LSW), are important components of the Atlantic Meridional Overturning Circulation (AMOC). Several studies have questioned the connection of the LSW production to the AMOC variability. This is partly due to the limited understanding of how this locally formed water mass leaves the interior of the Labrador Sea. In this study, the pathways and the timescales of the water masses exiting the Labrador Sea via the boundary current are investigated by Lagrangian particle tracking. This method is applied to the output of a strongly-eddying idealized model that is capable of representing the essential physical processes involved in the cycle of convection and restratification in the Labrador Sea. The Lagrangian trajectories reveal that prior to exiting the domain the water masses follow either a fast route within the boundary current or a slower route that involves boundary current-interior exchanges. The densest water masses exiting the Labrador Sea stem from this slow route, where particles experience strong water mass transformation while in the interior. In contrast, the particles that follow the fast route experience water mass transformation in the boundary current at the western side of the domain only, yielding a lighter product. Although both routes carry roughly the same transport, we show that 60% of the overturning in density space is associated with the volume transport carried by particles that follow the slow route. This study further highlights that the export of dense water masses, which is governed by the eddy activity in the basin, yields export timescales that are usually longer than a year. This underlines the necessity of resolving the mesoscale features required to capture the interior–boundary current exchange in order to correctly represent the export of the LSW.

Dosimetric properties of thermoluminescent pellets of CaSO4 doped with rare earths at low doses

Thermoluminescent dosimeters are widely used in radiation dosimetry, including low dose applications such as personal dosimetry. This work aimed to manufacture thermoluminescent pellets using CaSO4:Tm; CaSO4:Dy,Tm; CaSO4:Dy, Tb and CaSO4:Dy, Eu phosphors and to study their dosimetric properties in comparison to commercially available CaSO4:Dy (TLD-900). The phosphors were synthesized by the slow evaporation route using a solution of sulfuric acid, calcium carbonate and the dopants. The pellets were manufactured using Teflon as aggregate agent. The glow curves of the different pellets were measured and the integral of the dosimetric peak was used as the dosimetric response for each material. The dose-response curves were measured in a dose range of 100 μG y to 50 mGy by 137Cs (γ-source) and X-rays (30 kVp up to 120 kVp). The energy dependence and fading of the pellets were also studied. Groups of 30 pellets were used to investigate the response homogeneity for the studied materials. The glow curves for all the studied materials (excluding CaSO4:Eu) showed the maximum luminescent emission at around 260 °C, but with different intensities. The CaSO4:Tm pellets showed the highest thermoluminescent emission among the studied materials. All the materials showed a linear response in the studied dose range, with CaSO4:Tm pellets showing the highest sensitivity at all radiation qualities. The highest energy dependence was found for the ISO N-40 beam quality (40 kVp X-rays) for all materials when compared to irradiations by the 137Cs source. A 7.7% fading for the CaSO4:Tm was found for a period of two months. All the manufactured pellets showed better dosimetric properties than the studied standard CaSO4:Dy.

Differential back‐pressure routing for single‐queue time‐varying wireless networks

Dynamic resource control and routing are important for realising the intelligent control of data transmission in wireless multi-hop networks. It is well known that back-pressure routing based on a max-weight policy maximises network throughput and optimises resource allocation in multi-hop wireless networks with time-varying channels. Due to the slow routing convergence and complex control of data queues, however, back-pressure routing also results in large end-to-end delays and a waste of network resources, particularly when the network loads are light or moderate. In this study, a differential back-pressure routing scheme with single-queue management is proposed to improve the packet delay performance and simplify the management of data queues. Unlike in traditional back-pressure routing, the authors use the differences in the rates of change in data queue length to calculate data pressure. Compared with the method of data backlog calculation based on queue length differences, this method achieves faster routing convergence. They also consider the ceiling problem for a single queue and enhance the effect of the queue cap on the routing metric by means of dynamic weighting. Simulation results show that the proposed routing algorithm achieves a 20% decrease in end-to-end delay in grid and random networks.

Dimensional ensemble and (topological) fracton thermodynamics: the slow route to equilibrium

The use of the dimensional-ensemble becomes compulsory when spatial dimensions are not well defined. Consequently, apart from temperature, thermodynamic equilibrium requires an additional configurational parameter. Two representative cases are considered in detail: oscillators with undefined spatial dimension and topological fractons. Spatial dimension and energy are determined as a function of temperature in both cases. At low temperatures, specific heat behaves exponentially, meaning it creates a slow route to equilibrium. In accordance with experiments, calculations suggest that the spatial dimension diminishes when temperature decreases. Parameter values are computed using data obtained from almost two-dimensional graphene and porous compounds.

MAPPING SPATIAL QUALITY OF SLOW ROUTES WITH A GIS-BASED METHOD A COMPARATIVE ASSESSMENT OF ALTERNATIVE ROUTES

Abstract. In the field of cultural tourism, slow routes, especially pedestrian and cycle routes, are considered important resources for sustainable, social and economic development of the territories. The cultural routes, defined by the Council of Europe, have extended the notion of conservation and valorization of cultural heritage to a wider territorial perspective, that allow to join tangible and intangible heritage dimensions, natural and built heritage, in a whole. In this framework, cultural routes, mainly used to rediscover the territory through slow-travel experience, need to be documented and ranked as a system of cultural heritage spread over the territory, by innovative and effective tools. The SQISR method (Spatial Quality Index of Slow Routes), at territorial level, allows to analyze the spatial features of slow routes through GIS-based mapping techniques, but also to compare alternative routes on the base of a set of heterogeneous indicators. The SQIRS method has been applied to evaluate two alternative itineraries of the Monks Route, that cross the agricultural landscape in southern Milan, with aim to document their spatial features and rank them in relation to their spatial quality. The SQISR method, that is based on a quantitative approach, allows to visualize the outcomes by different ways: graded GPS tracks, graphs, diagrams.

A Routing Protocol Combining Link State and Distance Vector for GEO-GEO Satellite Backbone Network

For the demand of GEO-GEO satellite backbone networking construction based on inter-satellite link and satellite-to-ground link, this study focuses on satellite routing protocol solution. At the beginning, the deficiency of terrestrial network routing protocol based on distance vector (for example: RIP) and link state (for example: OSPF) applied directly to GEO-GEO satellite backbone network is analyzed. It proves to have problems such as excessive link cost and slow routing convergence rate. Therefore a novel satellite routing protocol for GEO-GEO satellite backbone network is proposed, which is called SDSRP (the link State and Distance vector combined Satellite Routing Protocol). Then the cost of satellite-to-ground link and route convergence are analyzed and simulated. The simulation results indicate that the proposed protocol can greatly reduce the satellite-to-ground link cost, and can obviously improve the routing convergence rate, which meet the requirements of GEO-GEO satellite backbone network application scenarios.

Potential power generation on a small-scale separated-type biomass gasification system

A small-scale separated-type biomass gasification system composed of a screw pyrolyzer, a steam tar reformer, an air-steam char fluidized bed gasifier, and a spent char combustor with heat carrier particles circulating is designed to convert woody biomass into combustible gas which can be applied for gas-engine power generation. In this study, the simulation results of this system based on two biomass pyrolysis routes, i.e., fast and slow pyrolysis, are analyzed and compared. During the simulations, the empirical equations as well as the main experimental data from the published literature are applied to analyze the elemental, mass, and energy balances of each process by using sets of assumptions at a certain condition to predict final energy efficiency and the potential electricity generated from the system. As a result, 12.5 kg/h of wood biomass feeding to this system has power generation ability of 16.8 kWe and 16.3 kWe with cold gas efficiencies of 73.8% and 71.7% for the fast and slow pyrolysis routes respectively. Comparison of product yields and compositions obtained in the present system with the reported data shows that the prediction gives a reasonable accuracy which could indicate what occur within the system. The calculation methods presented in this study could be utilized for preliminary engineering design of comprehensive biomass thermal conversion processes.