Behavior of Osteoclast Cells Response on Dicalcium Phosphate Dihydrate Layer-Coated β-Tricalcium Phosphate Granular

The aim of this study is to investigate the behavior of osteoclast cells response on dicalcium phosphate dihydrate (DCPD) layer-coated β-TCP granules. β-TCP granules with 300-600 μm were exposed to acidic calcium phosphate solution for 30 mins in order to get 10 mol% DCPD layer-coated β-TCP granular. DCPD free-coated β-TCP granular had used as control specimen. Both specimens were implant in 9 mm of rat calvarial bone defect for 4 weeks. After 4 weeks, the block section of rat calvarial containing specimen were removed for Tatrate-Resistance Acid Phosphatase (TRAP) analysis. Results of TRAP staining reveal that the number of osteoclast cells attached on 10 mol% layer-coated β-TCP granular is higher than DCPD free-coated β-TCP granular. Since remodeling of new bone formation involved simultaneous osteoclast and osteoblast cells response, therefore, the results obtained in this study indicated that the presence of DCPD layer-coated on β-TCP granular helps to improve osteoclast cells response that contribute in stimulating new bone formation.

Modeling and simulation of intersection quasi-moving block speed guidance based on connected vehicles

Purpose This study aims to propose a speed guidance model of the CV environment to alleviate traffic congestion at intersections and improve traffic efficiency. By introducing the theory of moving block section for high-speed train control, a speed guidance model based on the quasi-moving block speed guidance (QMBSG) is proposed to direct platoon including human-driven vehicles and connected vehicles (CV) through the intersection coordinately. Design/methodology/approach In this model, the green time of the intersection is divided into multiple block intervals according to the minimal safety headway. Connected vehicles can pass through the intersection by following the block interval using the QMBSG model. The block interval is assigned dynamically according to the traveling relation of HV and CV, when entering the communication range of the intersection. To validate the comprehensive guidance effect of the proposed model, a general evaluation function (GEF) is established. Compared to CVs without speed guidance, the simulation results show that the GEF of QMBSG model has an obvious improvement. Findings Compared to CVs without speed guidance, the simulation results show that the GEF of QMBSG model has an obvious improvement. Also, compared to the single intersection speed guidance model, the GEF value of the QMBSG model improves over 17.1%. To further explore the guidance effect, the impact of sensitivity factors of the CVs’ environment, such as intersection environment, communication range and penetration rate (PR) is analyzed. When the PR reaches 75.0%, the GEF value will change suddenly and the model guidance effect will be significantly improved. This paper also analyzes the impact of the length of block interval under different PR and traffic demands. It is found that the proposed model has a better guidance effect when the length of the block section is 2 s, which facilitates traffic congestion alleviation of the intersection in practice. Originality/value Based on the aforementioned discussion, the contributions of this paper are three-fold. Based on the traveling information of HV/CV and the signal phase and timing plans, the QMBSG model is proposed to direct platoon consisting of HV and CV through the intersection coordinately, by following the block interval assigned dynamically. Considering comprehensively the indexes of mobility, safety and environment, a GEF is provided to evaluate the guidance effect of vehicles through the intersection. Sensitivity analysis is carried out on the QMBSG model. The key communication and traffic parameters of the CV environment are analyzed, such as path attenuation, PR, etc. Finally, the effect of the length of block interval is explored.

A Discrete-Space Train Movement Model for a High-Speed Train under Temporary Speed Restriction

This paper constructs a discrete-space train movement model to evaluate the impact of a temporary speed restriction (TSR) for a high-speed railway train. The established model can demonstrate train movement under different TSR conditions. The proposed model can reveal whether a train is affected by the block section influenced by the TSR within a time duration. Moreover, the model can output detailed train trajectories and the minimal train running time between two adjacent stations to analyse the impact of the TSR. Based on the experimental results, we carry out a comprehensive analysis of the impact of several factors on the running time and train trajectories, including the length of the affected area (i.e., number of affected block sections), the location of the TSR, the limited speed value, and the stopping patterns of the train at two adjacent stations. The experiments show that the proposed discrete-space train movement model can be used to analyse the impact of the TSR on a high-speed railway train under various considered TSR conditions.

Peculiarities of residential buildings deformation with connected block-sections collision as a result of uneven settlement on collapsible soils

Instrumental inspections and studies experience and results of nine-storeyed residential buildings block-sections actual strained-deformed state under the conditions of their collision in territories of 25 to 35 m thick collapsible soils in Zaporizhzhia city and the subsidence value of 100 cm and more are summarized. It is shown that depending on the process of uneven settlement in the time value of deviation vectors is stabilized over time along with the stabilization of subsidence and deformation of block-section structures on the collision area. It has been established that uneven settlement growth processes stabilization, block-sections deviation from vertical and collision forces is achieved at equilibrium between subsidence values, collision forces of block-sections and resistance of wall sections.

Verification of Puffin Modelling Using VISSIM

Puffin crossing is the most recent signalised crossings in UK. The operation of Puffin signal control is mainly based on traffic condition hence could impose longer waiting time on pedestrian. Therefore there is a need to review on the operation of the signal control strategy of Puffin crossings to make it more pedestrian responsive without imposing significant delay to other road users. Research to date has shown that VISSIM model is more suitable for the evaluation of signal control improvement. The latest signal controlled pedestrian crossing facility, the Puffin, has been modelled and tested in VISSIM micro-simulation model. The objective of this study is to verify the Puffin coding using VISSIM microsimulation software. It is to ensure that the Puffin signal control in VISSIM is working as in a real traffic condition. For this purpose a suitable mid-block section was selected at Market Street, United Kingdom. Pedestrians' characteristics, vehicular characteristics, geometric layout of the site were retrieved from video recording. All these characteristics were coded in Puffin model using VISSIM micro-simulation. The results proved that the Puffin model in VISSIM is able to reproduce site representative condition. The findings in this study are significant in the whole modelling process.