A comparative study of automotive trip characteristics between older drivers and others among densely inhabited district and other areas

This paper examines older driver＇s automotive trip （abbreviation： trip） characteristics which include trip frequency, trip length, destination distribution, and non- home-based （NHB） trips. A two-month experiment of 108 participants was carried out to collect GPS tracking data in Aichi Prefecture, Japan. To identify the effect of living area, a comparative analysis between older drivers and others is conducted in densely inhabited district （DID, i.e., urban） and other areas （non-DID, i.e., suburban, rural, etc）, separately. The present study found that there was no sig- nificant difference between the trip characteristics of older drivers and others who were living in DID. Thus, we suggest that the education of safety driving and the rec- ommendation of public transportation should be given to DID-living older drivers. However, the results of non-DID reflected that older drivers＇ trip frequency, trip length, destination, and NHB trips rate were shorter and lower than others＇. This implies that electric vehicles may be suit- able for promotion among older drivers in suburban and rural area. Furthermore, the regression analysis confirmed that ＂older driver＂ was a significant independent variable on trip frequency, trip length, and NHB trips, and there were interaction effects between ＂older driver＂ and ＂living areas＂ on all trip characteristics.

Surface Modification of PEEK and Its Osteoconductivity and Anti-Inflammatory Properties

Polyetheretherketone (PEEK) is known as one of the “super-engineering plastics” and is used as an intervertebral disk spacer in the body. PEEK has a hydrophobic surface (water contact angle (WCA) > 80°) and high chemical resistance, and it is thus difficult to perform any surface treatment, such as hydrophilization. In this study, we aimed to form a hydrophilic surface on PEEK without coating layers by using hydroprocessing (aqueous solution processing), and we examined the osteoconductivity and anti-inflammatory properties of surface-treated PEEK in vivo compared with Ti implants. The WCA value of PEEK reached ~20° using a combination of immersion in a solution of >16.2 M H2SO4 and ultraviolet irradiation (172 nm). In in vivo testing, the hydrophilization of PEEK by surface modification without a coating layer improved the osteoconductivity and anti-inflammatory properties. The relationship between the bone-implant contact ratio and the WCA values of the surface-modified PEEK agreed well with that of the surface-treated Ti.

Numerical Simulation of Jet Issuing Diagonally Upward into Density-Stratified Fluid in Cylindrical Tank

This study simulates the behavior of a jet issuing into a two-layer density-stratified fluid in a cylindrical tank and the resulting mixing phenomena. The upper and lower fluids are water and an aqueous solution of sodium chloride (NaCl), respectively, with the lower fluid issuing diagonally upward from a nozzle on the bottom of the tank. The angle between the centerline of the jet and the tank bottom is 60°. The phenomena when the Reynolds number Re of the jet is 475, 1426, and 2614 are simulated. The mass concentration of the aqueous solution of NaCl is 0.02. The simulation successfully grasps the jet behavior and the resulting mixing, which agree with the authors’ experimental results at the corresponding Re value. The secondary flows that appear in the horizontal cross-sections consist of a pair of vortices and flows along the tank wall. The secondary flow at the density interface represents the intrusion of an internal density current, which gives rise to mixing along the interface.

Behavior of a Jet Issuing Diagonally Upward into Two-Layer Density-Stratified Fluid in a Cylindrical Tank

This study is concerned with the experimental investigation of a jet issuing diagonally upward into a two-layer density-stratified fluid in a cylindrical tank and the resulting mixing phenomena. The upper and lower fluids are water and an aqueous solution of sodium chloride (NaCl), respectively, and the lower fluid issues from a nozzle on the bottom of the tank. The angle between the centerline of the jet and the bottom of the tank is 60o, and the mass concentration of the NaCl solution is 0.02. The investigation reveals that secondary flow is caused by the jet in the horizontal cross-sections of the tank and that it is composed of a pair of vortices. It confirms that the secondary flow at the density interface corresponds to an internal density current. The investigation also clarifies the effect of the Reynolds number of the jet on mixing between the lower and upper fluids.

Experimental Study of Flow around a Circular Cylinder inside a Bubble Plume

This study experimentally explores the flow around a cylinder with circular cross-section placed inside a bubble plume. Small gas bubbles with diameter smaller than 0.06 mm are released from electrodes on the bottom of a water tank by electrolysis of water. The bubbles induce water flow around them as they rise because of buoyancy. Inside the generated bubble plume, a cylinder with diameter D of 30 mm is placed at 6.5D above the electrodes. The bubbles and water flow around the cylinder are visualized, and the bubble velocity distribution is measured. The experiments elucidate the bubble behavior around the cylinder, the separated shear layers originating at the cylinder surface, their roll-up, the bubble entrainment in the resultant large-scale eddies behind the cylinder, and the vortex shedding from the cylinder.

Modeling of the impurity-induced silicon nanocone growth by low energy helium plasma irradiation

The formation mechanism of nanocone structure on silicon(Si)surface irradiated by helium plasma has been investigated by experiments and simulations.Impurity(molybdenum)aggregated as shields on Si was found to be a key factor to form a high density of nanocone in our previous study.Here to concrete this theory,a simulation work has been developed with SURO code based on the impurity concentration measurement of the nanocones by using electron dispersive x-ray spectroscopy.The formation process of the nanocone from a flat surface was presented.The modeling structure under an inclining ion incident direction was in good agreement with the experimental result.Moreover,the redeposition effect was proposed as another important process of nanocone formation based on results from the comparison of the cone diameter and sputtering yield between cases with and without the redeposition effect.

A Feasibility Study of Power Generation from Sewage Using a Hollowed Pico-Hydraulic Turbine

This study is concerned with the feasibility of power generation using a pico-hydraulic turbine from sewage flowing in pipes. First, the sewage flow rate at two connection points to the Toyogawa River-Basin Sewerage, Japan, was explored for over a year to elucidate the hydraulic energy potential of the sewage. Second, the performance of the pico-hydraulic turbine was investigated via laboratory experiments that supposed the turbine to be installed in the sewage pipe at the connection points. This study indicates that the connection points have hydraulic potential that can be used for power generation throughout the year. It also demonstrates that the pico-hydraulic turbine can be usefully employed for power generation from sewage flowing in the pipe at the connection points.

Osteoconductivity Control Based on the Chemical Properties of the Implant Surface

Metallic materials, such as Ti, Zr, Nb, Ta, and their alloys, and also stainless steels are widely attractive as osteoconductive materials in the dental and orthopedic fields. Ceramics and polymers are also commonly used as biomaterials. However, they do not have high osteoconductivity in their pure form, and surface coatings with bioactive substances, such as hydroxyapatite or TiO2, are needed before implantation into the bone. Many reports claim that the surface chemical properties of implants, in particular, hydrophilicity and hydrophobicity, strongly affect the biological reactions. However, the effect of surface properties on osteoconductivity is not clear. In this review, we focus on the relationship between the surface hydrophilicity of metallic implants and osteoconductivity using in vivo evaluation, and the control of the osteoconductivity is discussed from the viewpoint of protein adsorption in implants.

Effect of Li Ions on Al Electrodeposition from Dimethylsulfone

The influence of LiCl coexistence with Al electrodeposition was investigated in a dimethyl sulfone, DMSO2, bath containing AlCl3 at 403 K. The electrochemical behaviors of Li and Al ions were examined using Pt electrodes in the bath and the deposition mechanism was analyzed by cyclic voltammetry, CV, with an Al reference electrode in the bath. The coexistence of LiCl in the AlCl3-DMSO2 bath inhibited the cathodic current corresponding to Al deposition in the CV experiment. The amount of ca. 500 μmol Al deposits was obtained in constant potential electrolysis for 1 h at –2 V in the bath with 10 mol% AlCl3. However, it decreased to 140 μmol Al in the bath with 10 mol% AlCl3 and 5 mol% LiCl. It was clarified that LiCl addition led to the formation of Li(DMSO2)+ more than the formation of ?from NMR measurement for the baths. This results in the suppression of Al deposition because LiCl inhibits the formation of complex ions, which is said to be necessary for Al electrodeposition.

Numerical Simulation of Mixing by Interaction of a Vortex Ring with a Density Interface

This study numerically explores the mixing caused by a vortex ring launched upward into a two-layer density-stratified fluid in a rectangular tank so as to search for a highly efficient mixing method.The upper and lower fluid layers are an aqueous glycerol solution and an aqueous solution of potassium dihydrogen phosphate(KH2PO4),respectively.The phenomena of vortex rings with Reynolds numbers of 4000,6000,and 8000 were simulated.The vortex-in-cell method is used to calculate the dynamics of the upper and lower fluids,and the CIP method is used to trace the concentration of the lower fluid.The simulations reproduce the mixing process successfully and elucidate the relationship between mixing efficiency and the Reynolds number of the vortex ring.

Mixing of Density-Stratified Fluid in a Cylindrical Tank by a Diagonal Jet

This study experimentally investigates the mixing of two-layer density-stratified fluid in a cylindrical tank by a diagonal jet.The upper and lower fluids are water and an aqueous solution of sodium chloride(NaCl),respectively,and the lower fluid issues from a nozzle on the tank bottom.The angle between the jet centerline and the tank bottom is 60°,and the mass concentration of the NaCl solution is 0.02.The mixing in cases that the Reynolds numbers of the jets are 713,2319,and 3565 is investigated.The velocity fields in the central vertical cross-section are measured with a PIV(particle imaging velocimetry)system by tracing nylon particles with the diameter of 80μm.The concentration fields in the section are visualized using Rhodamine B as the fluorescent dye.They are also measured using PLIF(planer laser induced fluorescence)from visualized images and the progresses of the mixing are evaluated quantitatively.The investigation clarifies the relationship between the mixing phenomena and the Reynolds number of the jet.

Molecules with a TEMPO-based head group as high-performance organic friction modifiers

High-performance organic friction modifiers(OFMs)added to lubricating oils are crucial for reducing energy loss and carbon footprint.To establish a new class of OFMs,we measured the friction and wear properties of N-(2,2,6,6-tetramethyl-1-oxyl-4-piperidinyl)dodecaneamide referred to as C12Amide-TEMPO.The effect of its head group chemistry,which is characterized by a rigid six-membered ring sandwiched by an amide group and a terminal free oxygen radical,was also investigated with both experiments and quantum mechanical(QM)calculations.The measurement results show that C12Amide-TEMPO outperforms the conventional OFMs of glyceryl monooleate(GMO)and stearic acid,particularly for load-carrying capacity,wear reduction,and stability of friction over time.The friction and wear reduction effect of C12Amide-TEMPO is also greatly superior to those of C12Ester-TEMPO and C12Amino-TEMPO,in which ester and amino groups replace the amide group,highlighting the critical role of the amide group.The QM calculation results suggest that,in contrast to C12Ester-TEMPO,C12Amino-TEMPO,and the conventional OFMs of GMO and stearic acid,C12Amide-TEMPO can form effective boundary films on iron oxide surfaces with a unique double-layer structure:a strong surface adsorption layer owing to the chemical interactions of the amide oxygen and free radical with iron oxide surfaces,and an upper layer owing to the interlayer hydrogen-bonding between the amide hydrogen and free radical or between the amide hydrogen and oxygen.Moreover,the intralayer hydrogen-bonding in each of the two layers is also possible.We suggest that in addition to strong surface adsorption,the interlayer and intralayer hydrogen-bonding also increases the strength of the boundary films by enhancing the cohesion strength,thereby resulting in the high tribological performance of C12Amide-TEMPO.The findings in this study are expected to provide new hints for the optimal molecular design of OFMs.

An analysis on older driver＇s driving behavior by GPS tracking data： Road selection, left/right turn, and driving speed

With the high older-related accident ratio and increasing population aging problem, understanding older drivers＇ driving behaviors has become more and more important for building and improving transportation system. This paper examines older driver＇s driving behavior which includes road selection, left/right turn and driving speed. A two-month experiment of 108 participants was carried out in Aichi Prefecture, Japan. Since apparently contradictory statements were often drawn in survey-based or simulators-based studies, this study collected not only drivers＇ basic information but also GPS data. Analysis of road selection demonstrates that older drivers are reluctant to drive on expressway not only in short trips but also in long trips. The present study did not find significant difference be- tween older drivers and others while turning at the intersections. To investigate the impact factors on driving speed, a random-effects regression model is constructed with explan- atory variables including age, gender, road types and the interaction terms between age and road types. Compared with other variables, it fails to find that age （60 years old or over） has significant impact on driving speed. Moreover, the results reflect that older drivers drive even faster than others at particular road types： national road and ordinary municipal road. The results in this study are expected to help improve transportation planning and develop driving assistance systems for older drivers.

Recent progress in tar removal by char and the applications:A comprehensive analysis

Tar catalytic removal by char is a promising technology for gasification process because of its porous structure,good catalytic activity,low cost,and easy to treatment after deactivation.To provide comprehensive information on the tar catalytic removal by char,this study focuses on the ongoing efforts and advances from fundamental researches to the industrial applications.The tar removal efficiency by char much depends on reaction conditions and char property,such as char origin,porous structure,the functional group on char surface,carbon structure,and AAEM components.The typical reaction kinetics,reaction mechanism,and the deactivation,will be introduced.Then,for the different gasification processes,the potential or typical applications of tar removal by char are discussed and compared.Finally,a comprehensive analysis and improvement in scaling up,commercializing tar removal technologies and integrating the gasification process,are also evaluated and analyzed in this review.

No external load measurement strategy for micro thermoelectric generator based on high-performance Si_(1-x-y)Ge_(x)Sn_(y) film

In this study,a micro in-plane p-type thermoelectric generator(TEG),which consists of thin-film Si_(1-x-y)Ge_(x)Sn_(y) ternary alloy semiconductor on insulator,is developed to make efficient use of waste heat such as human body.A power factor value as high as 1095 mWm^(-1) K^(-2) had been achieved using Bion implanted and short-term rapid thermal annealing(RTA)process.In addition,a measuring scheme for micro TEG without external load resistance was designed.In one measuring session,multiple parameters can be measured.The micro single-arm TEG prepared by semiconductor process can output 0.29 nW power at a temperature difference of 15 K,and a cross-sectional power density has reached up to 0.58 mW/cm^(2),which is a superior value for wearable device.The findings of this study have important reference value for wearable device performance improvement and output power measuring of micro TEG.

Modeling the degradation mechanisms of AlGaN-based UV-C LEDs:from injection efficiency to mid-gap state generation

In this work,we analyze and model the effect of a constant current stress on an ultraviolet light-emitting diode with a nominal wavelength of 285 nm.By carrying out electrical,optical,spectral,and steady-state photocapacitance(SSPC)analysis during stress,we demonstrate the presence of two different degradation mechanisms.The first one occurs in the first 1000 min of stress,is ascribed to the decrease in the injection efficiency,and is modeled by considering the defect generation dynamics related to the de-hydrogenation of gallium vacancies,according to a system of three differential equations;the second one occurs after 1000 min of stress and is correlated with the generation of mid-gap defects,for which we have found evidence in the SSPC measurements.Specifically,we detected the presence of deep-level states(at 1.6 eV)and mid-gap states(at 2.15 eV),indicating that stress induces the generation of non-radiative recombination centers.

Full-duplex light communication with a monolithic multicomponent system

A monolithic multicomponent system is proposed and implemented on a III-nitride-on-silicon platform,whereby two multiple-quantum-well diodes(MQW-diodes)are interconnected by a suspended waveguide.Both MQW-diodes have an identical low-In-content InGaN/Al0.10Ga0.90N MQW structure and are produced by the same fabrication process flow.When appropriately biased,both MQW-diodes operate under a simultaneous emission-detection mode and function as a transmitter and a receiver at the same time,forming an in-plane full-duplex light communication system.Real-time full-duplex audio communication is experimentally demonstrated using the monolithic multicomponent system in combination with an external circuit.

Autonomous Dual Active Power-frequency Control in Power System with Small-scale Photovoltaic Power Generation

Active power control of the photovoltaic(PV)power generation system is a promising solution to regulate frequency fluctuation in a power system with high penetration of renewable energy.This paper proposes an autonomous active power control of a small-scale PV system for supporting the inertial response of synchronous generators and power-frequency control.In the proposed control approach,an effective grid frequency regulation scheme is realized using slow-and fast-frequency responses.A low-pass filter based frequency measurement is used for slow-frequency response,while direct frequency measurement is used for fast-frequency response.The designed dual droop characteristic-based control is shaped to achieve a smooth transition between slow-and fast-frequency responses.The performance of the proposed control approach is demonstrated for serious disturbance scenarios,i.e.,considerable power-load imbalance and generation trip.In the powerload imbalance test scenario,the proposed control approach works properly within the normal frequency deviation region even when the frequency deviation exceeds that region occasionally.In the generation trip test,the frequency deviation is mitigated quickly,and the employed droop control is smoothly transferred from the slow-to fast-frequency responses.

Examining unobserved factors associated with red light running in Vietnam:A latent class model analysis

Red-light running(RLR)is a crucial violation that causes traffic accidents and injuries.Understanding factors that affect RLR is very significant to reduce the potential of this violation.Current studies have paid considerable attention to the observable factors,but not to unobservable factors.This study aims to examine the effects of observable and unobservable factors on RLR.This study uses a latent class model(LCM)to assign individuals into two classes—red-light-respectful and red-light-disrespectful road users—by surveying 751 respondents who use private transportation modes.This study incorporates psychological determinants into the LCM to account for unobservable factors.The contribution of this study is the in-depth investigation into law-respectful and law-disrespectful behaviours and intentional and unintentional violators.Such a study has not yet been conducted in the existing literature.In addition,a comprehensive comparison of the LCM and a traditional ordered probit model was conducted.Overall,the results suggest that the LCM is superior to the model that does not consider latent classes.Our estimation results are in alignment with previous studies on RLR:males,younger drivers/riders,less educated road users and motorcyclists are more likely to run red lights.An analysis of the latent variables shows that surrounding conditions—the behaviour of other violators,the absence of traffic police,and long waiting times—increase the possibility of violations.Based on these results,we provide suggestions to policymakers and traffic engineers:the implementation of enforcement cameras and penalties for violators are critical countermeasures to minimize the potential of RLR.