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Can We Estimate the Impacts of Fixed Links Using Current Transport Models?Experiences from Concept Evaluations of Fixed Links on E39
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作者 Trude Tørset 《Journal of Traffic and Transportation Engineering》 2024年第2期92-106,共15页
Transport analysis and impact evaluations are important input for decisions about infrastructure projects.The impacts on transport from fjord crossing tunnels or bridges are the foundation for the cost benefit analysi... Transport analysis and impact evaluations are important input for decisions about infrastructure projects.The impacts on transport from fjord crossing tunnels or bridges are the foundation for the cost benefit analysis,and also the basis for estimating the income from toll collection.Based on experiences from concept evaluations of several fixed link projects on E39,and an ongoing overall analysis,we question the results from transport analysis made by the official tools for such analysis:the RTM(regional transport model)which estimates the demand for trips below 10 km,the NTM(national transport model),for trips of 10 km or more,and the freight transport model.Both the NTM and the freight transport model are integrated in the RTM in the net assignment stage.We will demonstrate strengths and weaknesses in the transport models by showing contra intuitive or questionable results using the model as it is.The following questions arose as the initial results from the transport model were presented:Are the transport models able to capture immediate as well as long-term impacts?How would different assumptions about the monetary costs on these projects affect the forecasted demand and the cost benefit analysis?Are there other and wider ranges of impacts,if the analysis covers the total coastal highway as a whole,compared to evaluating impacts of each fixed link project individually?Do we have enough data to include transport effects of wider impacts of the fixed link projects?We had to deal with these questions in the concept evaluations carried out for the various fixed links project and in the current overall evaluation.We would like to suggest improvements in the analysis tools and emphasize requirements for knowledge about impacts of fixed links projects. 展开更多
关键词 transport models transport analysis evaluation
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A multiscale 3D finite element analysis of fluid/solute transport in mechanically loaded bone 被引量:3
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作者 Lixia Fan Shaopeng Pei +1 位作者 X Lucas Lu Liyun Wang 《Bone Research》 SCIE CAS CSCD 2016年第3期154-163,共10页
The transport of fluid, nutrients, and signaling molecules in the bone lacunar-canalicular system (LCS) is critical for osteocyte survival and function. We have applied the fluorescence recovery after photobleaching... The transport of fluid, nutrients, and signaling molecules in the bone lacunar-canalicular system (LCS) is critical for osteocyte survival and function. We have applied the fluorescence recovery after photobleaching (FRAP) approach to quantify load-induced fluid and solute transport in the LCS in situ, but the measurements were limited to cortical regions 30-50 μm underneath the periosteum due to the constrains of laser penetration. With this work, we aimed to expand our understanding of load-induced fluid and solute transport in both trabecular and cortical bone using a multiscaled image-based finite element analysis (FEA) approach. An intact murine tibia was first re-constructed from microCT images into a three-dimensional (3D) linear elastic FEA model, and the matrix deformations at various locations were calculated under axial loading. A segment of the above 3D model was then imported to the biphasic poroelasticity analysis platform (FEBio) to predict load-induced fluid pressure fields, and interstitial solute/fluid flows through LCS in both cortical and trabecular regions. Further, secondary flow effects such as the shear stress and/or drag force acting on osteocytes, the presumed mechano-sensors in bone, were derived using the previously developed ultrastructural model of Brinkman flow in the canaliculi. The material properties assumed in the FEA models were validated against previously obtained strain and FRAP transport data measured on the cortical cortex. Our results demonstrated the feasibility of this computational approach in estimating the fluid flux in the LCS and the cellular stimulation forces (shear and drag forces) for osteocytes in any cortical and trabecular bone locations, allowing further studies of how the activation of osteocytes correlates with in vivo functional bone formation. The study provides a promising platform to reveal potential cellular mechanisms underlying the anabolic power of exercises and physical activities in treating patients with skeletal deficiencies. 展开更多
关键词 A multiscale 3D finite element analysis of fluid/solute transport in mechanically loaded bone FIGURE
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An Analysis of the Air Parcel Trajectories of Long-Range Transport at Shanghai
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作者 邵德民 张维 +3 位作者 沈爱华 陈雪琴 付哲民 何珍珍 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1992年第3期346-350,共5页
1.INTRODUCTION Acid rain observations show that acid cloud water in Shanghai region appears not only
关键词 ACID An analysis of the Air Parcel Trajectories of Long-Range transport at Shanghai
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Physical vapor transport crystal growth of ZnO
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作者 刘洋 马剑平 +2 位作者 刘富丽 臧源 刘艳涛 《Journal of Semiconductors》 EI CAS CSCD 2014年第3期11-15,共5页
Zinc oxide(ZnO) has a wide band gap, high stability and a high thermal operating range that makes it a suitable material as a semiconductor for fabricating light emitting diodes(LEDs) and laser diodes, photodiodes... Zinc oxide(ZnO) has a wide band gap, high stability and a high thermal operating range that makes it a suitable material as a semiconductor for fabricating light emitting diodes(LEDs) and laser diodes, photodiodes, power diodes and other semiconductor devices. Recently, a new crystal growth for producing ZnO crystal boules was developed, which was physical vapor transport(PVT), at temperatures exceeding 1500 ?C under a certain system pressure. ZnO crystal wafers in sizes up to 50 mm in diameter were produced. The conditions of ZnO crystal growth, growth rate and the quality of ZnO crystal were analyzed. Results from crystal growth and material characterization are presented and discussed. Our research results suggest that the novel crystal growth technique is a viable production technique for producing ZnO crystals and substrates for semiconductor device applications. 展开更多
关键词 ZnO crystal boules physical vapor transport(PVT) sublimation impurity analysis growth rate
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Performance Enhancement in Dye-Sensitized Solar Cells with Composite Mixtures of TiO_2 Nanoparticles and TiO_2 Nanotubes 被引量:5
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作者 D.Maheswari P.Venkatachalam 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2015年第3期354-361,共8页
In the present investigation,a new composite nanostructured photoanodes were prepared using TiO_2 nanotubes(TNTs) with TiO_2 nanoparticles(TNPs).TNPs were synthesized by sol-gel method,and TNTs were prepared throu... In the present investigation,a new composite nanostructured photoanodes were prepared using TiO_2 nanotubes(TNTs) with TiO_2 nanoparticles(TNPs).TNPs were synthesized by sol-gel method,and TNTs were prepared through alkali hydrothermal method.Dye-sensitized solar cells(DSSCs) were fabricated with different photoanodes comprising of various ratios of TNTs + TNPs,synthetic indigo dye as photosensitizer,PMII(l-propyl-3-methylimidazolium iodide) as ionic liquid electrolyte and cobalt sulfide as counter electrode.The structures and morphologies of TNPs and TNTs were analyzed through X-ray diffractometer,transmission electron microscope and scanning electron microscopes.The results of the investigation showed that the DSSC-4 made with composite photoanode structure(TNTs/TNPs)(90% of TNPs + 10% of TNTs) had improved photocurrent efficiency(2.11%) than pure TNPs(1.00%) and TNT film(0.78%).Electrochemical impedance spectra revealed that the composite TNTs/TNPs film-based DSSCs possessed the lowest charge-transfer resistances and longest electron lifetime.Hence,it could be concluded that the composite TNTs/TNPs photoanode facilitates the charge transport rate and enhances the efficiencies of DSSCs. 展开更多
关键词 TNPs/TNTs composite mixtures Charge recombination Electron transport Photovoltaic parameters EIS analysis
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Estimating traffic volume on Wyoming low volume roads using linear and logistic regression methods 被引量:1
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作者 Dick Apronti Khaled Ksaibati +1 位作者 Kenneth Oerow Jaime Jo Hepner 《Journal of Traffic and Transportation Engineering(English Edition)》 2016年第6期493-506,共14页
Traffic volume is an important parameter in most transportation planning applications. Low volume roads make up about 69% of road miles in the United States. Estimating traffic on the low volume roads is a cost-effect... Traffic volume is an important parameter in most transportation planning applications. Low volume roads make up about 69% of road miles in the United States. Estimating traffic on the low volume roads is a cost-effective alternative to taking traffic counts. This is because traditional traffic counts are expensive and impractical for low priority roads. The purpose of this paper is to present the development of two alternative means of cost- effectively estimating traffic volumes for low volume roads in Wyoming and to make recommendations for their implementation. The study methodology involves reviewing existing studies, identifying data sources, and carrying out the model development. The utility of the models developed were then verified by comparing actual traffic volumes to those predicted by the model. The study resulted in two regression models that are inexpensive and easy to implement. The first regression model was a linear regression model that utilized pavement type, access to highways, predominant land use types, and population to estimate traffic volume. In verifying the model, an R^2 value of 0.64 and a root mean square error of 73.4% were obtained. The second model was a logistic regression model that identified the level of traffic on roads using five thresholds or levels. The logistic regression model was verified by estimating traffic volume thresholds and determining the percentage of roads that were accurately classified as belonging to the given thresholds. For the five thresholds, the percentage of roads classified correctly ranged from 79% to 88%. In conclusion, the verification of the models indicated both model types to be useful for accurate and cost-effective estimation of traffic volumes for low volume Wyoming roads. The models developed were recommended for use in traffic volume estimations for low volume roads in pavement management and environmental impact assessment studies. 展开更多
关键词 Traffic volume estimation Low volume road Wyoming county roads transportation planning Regression analysis
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Lithium ion conduction and ion-polymer interaction in poly(vinyl pyrrolidone) based electrolytes blended with different plasticizers 被引量:2
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作者 K.Kesavan Chithra M.Mathew S.Rajendran 《Chinese Chemical Letters》 SCIE CAS CSCD 2014年第11期1428-1434,共7页
Poly(ethylene oxide), poly(vinyl pyrrolidone)(PEO/PVP), lithium perchlorate salt(Li Cl O4) and different plasticizer based, gel polymer electrolytes were prepared by the solvent casting technique. XRD results ... Poly(ethylene oxide), poly(vinyl pyrrolidone)(PEO/PVP), lithium perchlorate salt(Li Cl O4) and different plasticizer based, gel polymer electrolytes were prepared by the solvent casting technique. XRD results show that the crystallinity decreases with the addition of different plasticizers. Consequently, there is an enhancement in the amorphousity of the samples responsible for the process of ion transport. FTIR spectroscopy is used to characterize the structure of the polymer and confirms the complexation of plasticizer with host polymer matrix. The ionic conductivity has been calculated using the bulk impedance obtained through impedance spectroscopy. Among the various plasticizers, the ethylene carbonate(EC) based complex exhibits a maximum ionic conductivity value of the order of2.7279 10 4S cm 1. Thermal stability of the prepared electrolyte films shows that they can be used in batteries at elevated temperatures. PEO(72%)/PVP(8%)/Li Cl O4(8%)/EC(12%) has the maximum ionic conductivity value which is supported by the lowest optical band gap and lowest intensity in photoluminescence spectroscopy near 400–450 nm. Two and three dimensional topographic images of the sample having a maximum ionic conductivity show the presence of micropores. 展开更多
关键词 Polymers Thermogravimetric analysis(TGA) X-ray diffraction Luminescence transport properties
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