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ToF ?????? ????????? ?????? ?????? ?????? ??????????????? ????????? ????????? ????????? ???????????? ??????(AngGo) ??????
No full textMany shared mobility services, such as electric scooters and bicycles, are available for outdoor use. However, finding a suitable shared mobility vehicle for indoor environments still presents a significant challenge. In this paper, we propose AngGo, a shared indoor smart mobility vehicle that can move conveniently in indoor spaces and communicate user intentions through interactions. AngGo is a chair-shaped mobility vehicle that has four modes: semi-autonomous driving mode, footplate manual driving mode, joystick manual driving mode, and standby mode. In the semi-autonomous mode, AngGo can search for potential users and navigate indoor spaces using six time-of-flight (ToF) distance sensors. Upon noticing that it was difficult for a user to board a moving AngGo, we developed a two-way mode switching interaction using ToF distance sensors: following and blocking. This allows AngGo to change its mode to the standby mode through certain movements of the user. In the standby mode, when the user boards the AngGo, it switches to the footplate manual driving mode. Thereafter, the user can change AngGo's mode to the joystick manual mode by pressing a joystick button. We also conducted a user experiment to evaluate the workload of the two methods in terms of switching mode interaction. The results showed no significant difference in workloads. However, based on the interviews, users preferred the following methods to blocking method
Room-Temperature Solid-State Synthesis of Cs3Cu2I5 Thin Films and Formation Mechanism for Its Unique Local Structure
No full textBlue-emitting Cs3Cu2I5 has attracted attention owing to its near-unity PL quantum yield and applications in DUV photodetectors and scintillators. Its PL properties originate from the unique local structure around the luminescent center, the [Cu2I5]3??? polyhedron iodocuprate anion consisting of the edge-shared CuI3 triangle and the CuI4 tetrahedron dimer, which is isolated by Cs+ ions. We found that solid-state reactions between CsI and CuI occur near room temperature (RT) to form Cs3Cu2I5 and/or CsCu2I3 phases. High-quality thin films of these phases were obtained by the sequential deposition of CuI and CsI by thermal evaporation. We elucidated that the formation of interstitial Cu+ and the antisite of I??? at the Cs+ site in the CsI crystal through Cu+ and I??? diffusion results in the RT synthesis of Cs3Cu2I5. The unique structure formation of the luminescent center was revealed using a model based on the low packing density of the CsCl-type crystal structure, similar sizes of Cs+ and I??? ions, and the high diffusivity of Cu+. The self-aligned patterning of the luminous regions on thin films was demonstrated
Response of granular anammox process under mainstream conditions to continuous and transient organic loads
No full textEven small fluctuations in the amount of organic matter in wastewater significantly affect the structure and function of anammox microbial communities under mainstream conditions with low ammonium concentrations, because a high organic C/N ratio causes heterotrophic denitrifying bacteria to outcompete anammox bacteria. This paper presents a comprehensive investigation of the effects of different levels of continuous and transient organic loads on nitrogen removal and sludge characteristics in upflow granular anammox reactors under mainstream conditions. Continuous organic load at 30 mg chemical oxygen demand (COD)/L influent improved nitrogen removal efficiency without compromising anammox performance. However, exposure to higher levels of continuous organic load (>= 60 mg COD/L) caused significant inhibition of anammox activity (complete inhibition at 150 mg COD/L). The performance degradation was accompanied by the destabilization of anammox granular sludge, with a decrease in tightly bound protein and increase in loosely bound polysaccharide contents in the sludge extracellular polymeric substances. Further, DNA sequencing analysis showed that heterotrophic denitrifying Rhodocyclaceae and Pseudomonadaceae bacteria collectively accounted for 36.8-61.3% of the total bacterial reads. These bacteria emerged and outcompeted anammox Ca. Brocadiaceae (accounting for less than 8.4% of the total reads) with increasing organic load, resulting in a significant decrease in anammox activity. Meanwhile, the inhibitory effect of transient organic load (one-day shock loading) was fully reversed within one day at both 150 and 300 mg COD/L shock levels, although the latter caused a sudden fall in anammox performance. The overall results suggest that loading an appropriately low amount of organic matter can provide a means to improve the nitrogen removal performance of anammox granular sludge without sacrificing anammox activity and granule stability under mainstream conditions
The risk assessment of arsenic contamination in the urbanized coastal aquifer of Rayong groundwater basin, Thailand using the machine learning approach
No full textThe rapid expansion of urbanization has resulted in an insufficient of groundwater resource. In order to use groundwater more efficiently, a risk assessment of groundwater pollution should be proposed. The present study used machine learning with three algorithms consisting of Random Forest (RF), Support Vector Machine (SVM), and Artificial Neural Network (ANN) to locate risk areas of arsenic contamination in Rayong coastal aquifers, Thailand and selected the suitable model based on model performance and uncertainty for risk assessment. The parameters of 653 groundwater wells (Deep=236, Shallow=417) were selected based on the correlation of each hydrochemical parameters with arsenic concentration in deep and shallow aquifer environments. The models were validated with arsenic concentration collected from 27 well data in the field. The model's performance indicated that the RF algorithm has the highest performance as compared to those of SVM and ANN in both deep and shallow aquifers (Deep: AUC=0.72, Recall=0.61, F1 =0.69; Shallow: AUC=0.81, Recall=0.79, F1 =0.68). In addition, the uncertainty from the quantile regression of each model confirmed that the RF algorithm has the lowest uncertainty (Deep: PICP=0.20; Shallow: PICP=0.34). The result of the risk map obtained from the RF reveals that the deep aquifer, in the northern part of the Rayong basin has a higher risk for people to expose to As. In contrast, the shallow aquifer revealed that the southern part of the basin has a higher risk, which is also supported by the location of the landfill and industrial estates in the area. Therefore, health surveillance is important in monitoring the toxic effects on the residents who use groundwater from these contaminated wells. The outcome of this study can help policymakers in regions to manage the quality of groundwater resources and enhance the sustainable use of groundwater resources. The novelty process of this research can be used to further study other groundwater aquifers contaminated and increase the effectiveness of groundwater quality management
ALH-E: A Deformable and Flexible Robot that provides Tangible Interaction for Pain Communication
No full textGrowth of high-density single-wall carbon nanotubes with a uniform structure using a CoRu catalyst
No full textThe inefficient production of structurally uniform single-wall carbon nanotubes (SWCNTs) is an obstacle to their practical use in high-performance electronic devices. We have synthesized SWCNTs with a narrow diameter distribution (1.35 +/- 0.25 nm) using a CoRu catalyst. Monodispersed nanoparticles with a narrow size dis-tribution (2.4 +/- 0.6 nm) and different compositions were prepared and used as catalysts for SWCNT growth. A furnace with an 80 cm-long uniform temperature zone (+/- 10 degrees C) was designed and used to study the effect of catalyst composition on the growth of SWCNTs under the same conditions. By optimizing the composition of the bimetallic CoRu catalyst, SWCNTs with a uniform structure were efficiently synthesized. In addition, the effect of the growth conditions of temperature and carbon feed rate was investigated, and it was found that with an increase in yield, the structural uniformity of SWCNTs usually became worse. Both catalysts with elements in the suitable proportions and appropriate growth conditions are critical to achieving the high-efficiency structure-controlled growth of SWCNTs
Mapping microbial dynamics in anaerobic digestion system linked with organic composition of substrates: Protein and lipid
No full textConsidering the energy potential and anaerobic biodegradability, protein and lipid are among the most significant organic components of many biogas feedstocks. Although the two core organics have typical structures, each category has compositional variations according to the source, and thus has different biogas potential and catabolic microbes. Therefore, this study analyzed the characteristics and biogas potential of ten model substrates: casein, gelatin, gluten, whey and pork liver as protein-rich (60.1 +/- 42.6%) substrates and glycerol, fish oil, soybean oil, butter and pork fat as lipid-rich (72.1 +/- 40.5%) substrates. During the digestion process, the maximum methane production and its production rate were 2 and 1.6 times higher in the lipid-rich group, while the lag phase was >2 times longer in the same group. The microbial community structure, determined by highthroughput sequencing, was clustered depending on the organic majority (either protein or lipid), with minor differences within the cluster. The protein-rich and lipid-rich substrates were estimated to generate energy up to 19910 and 7781.8 kJ/kg, respectively, based on the energy analysis. Overall, the complex biochemical process of anaerobic digestion will be better understood based on the proposed microbial dynamics concerning different organic substrate compositions
Entropy minimization of the non-Newtonian bio-hybrid (Fe3O4-CuO/blood) nanofluid flow over a linear extending sheet by means of induced magnetic field
No full textThe physiological system loses heat energy through the bloodstream to nearby cells. Such energy loss can lead to a quick death, anemia, severe hypothermia and high or low blood pressure to heart surgery. As a result, biomedical engineers and physicians are increasingly attracted to the study of entropy production to calculate the energy loss of biological systems. Furthermore, the thermodynamic state of entropy production is used to access cancer cells during chemotherapy treatment and heat transfer in tissues. The current model intends to explore the significance of the non-Fourier heat flux model on Eyring-Powell/Maxwell hybrid nanofluid (Fe3O4-CuO/blood) flow in a linear extending sheet with induced magnetic field and entropy generation. Suitable self-similarity variables are performed to convert momentum and thermal equations determined using the homotopy perturbation method into ordinary differential equations. The significance of distinct physical parameters such as thermal relaxation parameter, volume fraction, fluid parameter, magnetic Prandtl number, Biot number, Brinkman number, heat source, Eckert number, radiation and heat source on velocity, temperature, skin friction coefficient, Nusselt number, entropy production, streamlines and isotherm are represented through figures. It is recognized that the fluid friction irreversibility is comparatively higher than thermal irreversibility and highly dominates the total entropy generation. The nanoparticle volume fraction diminishes the velocity and induced magnetic field of both Eyring-Powell and Maxwell hybrid nanofluid. Fluid friction irreversibility is more in Maxwell fluid compared to the Eyring-Powell fluid
Theory of sigma bond resonance in flat boron materials
No full textIn chemistry, theory of aromaticity or pi bond resonance plays a central role in intuitively understanding the stability and properties of organic molecules. Here we present an analogue theory for sigma bond resonance in flat boron materials, which allows us to determine the distribution of two-center two-electron and three-center two-electron bonds without quantum calculations. Based on this theory, three rules are proposed to draw the Kekule-like bonding configurations for flat boron materials and to explore their properties intuitively. As an application of the theory, a simple explanation of why neutral borophene with similar to 1/9 hole has the highest stability and the effect of charge doping on borophene's optimal hole concentration is provided with the assumption of sigma and pi orbital occupation balance. Like the aromaticity theory for carbon materials, this theory greatly deepens our understanding on boron materials and paves the way for the rational design of various boron-based materials
Room-Temperature Hydrogen Sensor with High Sensitivity and Selectivity using Chemically Immobilized Monolayer Single-Walled Carbon Nanotubes
No full textAlthough semiconducting single-walled carbon nanotubes (sc-SWNTs) exhibit excellent sensing properties for various gases, commercialization is hampered by several obstacles. Among these, the difficulty in reproducibly fabricating sc-SWNT films with uniform density and thickness is the main one. Here, a facile fabrication method for sc-SWNT-based hydrogen (H-2) sensors with excellent reproducibility, high sensitivity, and selectivity against CO, CO2, and CH4 is reported. Uniform-density and monolayer sc-SWNT films are fabricated using chemical immobilized through the click reaction between azide-functionalized polymer-wrapped sc-SWNTs and immobilized alkyne polymer on a substrate before decorating with Pd nanoparticles (0.5-3.0 nm). The optimized sc-SWNT sensor has a high room-temperature response of 285 with the response and recovery times of 10 and 3 s, respectively, under 1% H-2 gas in air. In particular, this sensor demonstrates highly selective H-2 detection at room temperature (25 degrees C), compared to other gases and humidity. Therefore, the chemical immobilization of the monolayer SWNT films with reproducible and uniform density has the potential for large-scale fabrication of robust room-temperature H-2 sensors