Bundle Configurations Research Articles

Polyimide Aerogel Fiber Bundles for Extreme Thermal Management Systems in Aerospace Applications.

Aerogel fibers are an emerging class of ultralightweight materials, which, compared to conventional bulk monolithic and aerogel films, provide better flexibility and extensibility. Despite the recent advancements in this field, due to their highly porous structure, their mechanical properties can be deteriorated. Inspired by the textile industry, we report the development of aerogel fiber bundles with twisted structures as a promising strategy to enhance the mechanical performance and practicality of aerogel fibers. Polyimide (PI) aerogel fibers were prepared via the sol-gel confined transition method. The fibers showed a unique nanostructured assembly with high specific surface area, excellent optical transparency, outstanding flexibility at diverse extreme conditions, self-extinguishing behavior, and superior thermal insulation performance. Using PI aerogel fibers as the backbone, aerogel fiber bundles in various configurations were designed and fabricated. A systematic study was performed to analyze the effect of design parameters on the mechanical performance of the bundles. Results revealed an optimal twist level for bundles, leading to a peak in mechanical properties across various bundle configurations. The observed improvement in mechanical properties was attributed to increased fiber-to-fiber binding strength, enhanced friction, and interlocking mechanism of fibers, underscoring the potential of the optimized twist level for enhancing the performance of aerogel fiber bundles. Overall, the development of aerogel fiber bundles holds great promise in revolutionizing the production of high-performance ultralightweight materials for thermal management applications.

Multi-scale collaborative prediction of optimal configuration for carbon fiber woven composites based on deep learning neural networks

Since carbon fiber woven composite panels contain complex fiber bundle structures, the aim of this paper is to investigate the factors influencing the macro-equivalent properties and topological flexibility of composite panels resulting from variations in fiber bundle configuration. Firstly, the structural topology optimization design of carbon fiber composite plates was achieved using a multi-scale modeling approach with the variable density method. Nonlinear relationships between carbon fiber bundle configuration parameters and macroscopic equivalent properties, as well as macroscale topological flexibility, were determined using deep learning methods, respectively. The maximum error in the predicted values of the deep learning network model does not exceed 0.5% when compared with the results of the finite element calculations. In addition, utilizing deep learning networks to predict macro-equivalent properties of composites can significantly decrease computational time. The impact of varying the number of filaments in fiber bundles and the spacing of the fiber bundles on the flexibility of the topology was determined using a deep learning network. The optimal topological flexibility, along with its corresponding fiber bundle spacing and number of fiber bundle filaments, are globally searched within the design domain using an adaptive genetic algorithm. The study in this paper can provide a reference for designing fiber bundle configurations of composites for practical applications.

Pool boiling heat transfer characteristics of low-GWP refrigerants in a horizontal tube bundle configuration

Heat transfer enhancement techniques have been adapted on the shell side to improve the overall performance of the flooded evaporators, such as finned tubes. In recent years, it has been demonstrated that the metal foam structure can offer enhanced heat transfer performance under pool boiling conditions. However, there are not much research in the open literature that examine the feasibility of metal foam embedded tubes in horizontal tube bundle configurations. Therefore, this paper proposed a novel metal foam embedded tube (i.e., foam embedded outside the tube) to improve the heat transfer behavior of flooded evaporators. The experiments were performed on a horizontal tube bundle with a staggered arrangement. Moreover, the performance of low global warming potential (GWP) refrigerants (R-1234yf and R-1234ze(E)) is compared against R-134a for both plain tubes and metal foam tubes with porosities of 81%, 75%, and 62%. The results showed that a metal foam tube with a porosity of 62% showed a maximum heat transfer coefficient (HTC) enhancement of 291% compared to the plain tube. As compared with R-134a, the HTCs of R-1234yf and R-1234ze(E) are nearly 10% higher and 5% lower, respectively.

Transient characterisation and analysis of shape memory alloy wire bundles for the actuation of finger joints in prosthesis design

Most current lower arm/hand prosthesis designs incorporate relatively bulky, heavy dc motors that produce substantial noise when performing actuation which rendersthem uncomfortable for the end-user. The engineering challenge is to produce more effective powered upper limb prosthetic solutions. Identification, characterisation and testing of actuation methods with better force to weight ratios are essential pre-requisites for this. The main aim of this work is to carry out a comprehensive study to establish conclusively the feasibility of employing Shape Memory Alloys (SMA’s) in the actuation of prosthetic finger designs. A comprehensive review of existing literature has been undertaken in order to establish the maximum grip forces at each phalanx of the human hand under different loading conditions. An experiment was developed in conjunction with this review to estimate the time response of the hand during a gripping/releasing action. These results, in combination with physical dimensions, will be used to drive the design of a prosthetic limb.
 A test rig has been developed which can facilitate complete transient and steady-state characterisation of a range of SMA wire diameters and bundle configurations. Anumber of different configurations were tested, each configuration having a different combination of 150 μm and 300 μm diameter nitinol wires. A data acquisition systemwas used to capture and retain data pertaining to the full characterisation of the bundles and in particular the strain and force capabilities of the various arrangements. A direct comparison is made between the actuator capabilities and the requirements of a working limb for basic gripping actions. This work will contribute to the development of an improved powered prosthetic solution.

Risky choice and diminishing sensitivity in MaaS context: A nonlinear logit analysis of traveler behavior

In the rapidly transforming landscape of urban transportation, Mobility-as-a-Service (MaaS) has emerged as a potentially transformative solution to adapt to fluctuating travel demand. However, despite arguments in the literature suggesting that uncertainty in travel plans may influence travelers’ preferences for MaaS, the extent and mechanisms of this impact remain relatively underexplored. This study aims to bridge this gap by evaluating travelers’ preferences toward MaaS subscriptions, mode choices, and their reactions to uncertainty within a risky-choice modeling framework. We incorporate a linear-specified benchmark model and two nonlinear models (one based on Expected Utility Theory with Constant Absolute Risk Aversion adjustments, and the other on Prospect Theory), to estimate travelers’ risk perceptions and their valuation of gains and losses associated with travel time and costs caused by occasional activities during commute trips. The data utilized in our study originates from a specifically designed stated preference survey carried out in Hong Kong. Our findings present insightful observations into MaaS bundle configurations, socio-demographic patterns, and notably, behaviors under uncertain circumstances. In the face of uncertainty, we observe a noticeable increase in reluctance to adopt MaaS, and a heightened preference for taxis. The models also underscore significant risk aversion and diminishing sensitivity concerning travel time and cost, with these tendencies proving more pronounced for travel time compared to cost. These insights are valuable for policymakers and MaaS operators, offering an enhanced understanding of users’ risk attitudes and the intricate interplay between travelers’ preferences for MaaS and the uncertainties inherent in daily travel.

Experimental investigation of in-flow fluidelastic instability for rotated triangular tube bundles subjected to single-phase and two-phase transverse flows

The in-flow fluidelastic instability of tube bundles prompted renewed interest since the recent unanticipated failure of the replacement steam generators at the San Onofre nuclear power station. A literature review on the topic discloses contrasting views, depending on the tube bundle and flow configuration addressed. In a recent paper, the authors reported experiments using square bundles, subjected to single and two-phase flows. No streamwise instability was observed, for the tested bundle configurations and the flow velocity ranges explored. In the present paper, experimental results obtained at CEA-Saclay for a rotated triangular tube bundle are presented, providing new in-flow fluidelastic data for both single-phase and two-phase transverse flows. The bundle consists of 50 tubes, with reduced pitch P/D = 1.44 and tube diameter D = 30 mm. It was subjected to single-phase (air or water) and two-phase air-water (with homogeneous void fraction in the range 40% to 98%) transverse flows. In the upper region of the bundle, several different flexibility configurations were tested, with up to 15 flexible tubes, mounted using anisotropic supports, which allow for in-flow vibrations. Results presented in the paper include in-flow fluidelastic stability data obtained for both single-phase and two-phase transverse flows. A detailed complex modal identification of the bundle under natural turbulence excitation was performed, at several flow velocities, highlighting the modeshapes which are prone to in-flow instability. Moreover, local void fraction and identified flow regimes are also presented. These results are discussed and compared to those obtained by previous authors, for similar tested configurations.

Enhancing heat exchanger performance through hybrid angle of attack control for drop-shaped tubes

In this study, a numerical investigation was conducted to explore the potential improvement in the overall performance of heat exchangers comprising drop-shaped tubes through the control of the angle of attack. A comprehensive analysis was conducted, evaluating eight distinct configurations of 20-row bundles consisting of drop-shaped tubes in both staggered and in-line arrangements. A thorough comparison was made against corresponding bundles with circular tubes. The study covered a range of Reynolds numbers Re = 1.78 × 103–1.87 × 104 and angles of attack θi−j = 0°–360°. Two methods were employed to evaluate the thermal-hydraulic performance. The findings indicated that the friction factor of case 6 of drop-shaped tube bundle (θ1−5 = 0°, θ6−10 = 330°, θ11−15 = 30°, θ16−20 = 0°) exhibited a reduction of approximately 27%–43% and 42%–46% compared to the staggered (case 3) and in-line (case 1) configurations of drop-shaped tube bundles at zero angles of attack, respectively. Additionally, case 6 achieved the highest thermal-hydraulic performance, surpassing the staggered bundles of circular tubes (case 3) by 1.4–1.8 times and the in-line bundles of circular tubes (case 1) by 2.9–3.5 times. Novel equations were derived to estimate the mean Nusselt number, effectiveness, and friction factor for case 6, exhibiting a maximum deviation of 0.74%, 0.48%, and 0.73% correspondingly.

Numerical treatment of heat recovery steam generator harps constructed from multiple tube bundle configurations

The heat recovery steam generator (HRSG) can be regarded as a heat exchanger, which uses the heat rejected from the gas cycle to supply steam for the vapor cycle. HRSGs are consisted of many tube bundles (or harps). Supplying a duct burner in the upstream of an HRSG necessitates constructing the first bundle using different finned-tube materials with dissimilar fin configurations including unequal fin-pitch sizes. The computational fluid dynamics (CFD) has been widely used to study the flow through tube bundles; however, considering a fixed fin-pitch size for all rows of the finned-tubes. There is no trace of numerical analyses to treat tube bundles with unequal fin pitch sizes, apparently, because there are major challenges for the classical strategies, say unified-domain approach, to simulate tube bundles constructed from tubes with different fin configurations. This work introduces the splitted-domain approach as an innovative strategy to pass over the challenges with using the unified-domain approach. Then, these two approaches are used to model the superheater module of a real HRSG with available online measured data. The calculated Nusselt numbers and pressure drops indicate that the splitted-domain approach provides more accurate results than the unified one in simulating tube bundles constructed from tubes with dissimilar fin configurations.

Strongly coupled QFT dynamics via TQFT coupling

We consider a class of quantum field theories and quantum mechanics, which we couple to ℤN topological QFTs, in order to classify non-perturbative effects in the original theory. The ℤN TQFT structure arises naturally from turning on a classical background field for a ℤN 0- or 1-form global symmetry. In SU(N) Yang-Mills theory coupled to ℤN TQFT, the non-perturbative expansion parameter is exp[−SI/N] = exp[−8π2/g2N] both in the semi-classical weak coupling domain and strong coupling domain, corresponding to a fractional topological charge configurations. To classify the non-perturbative effects in original SU(N) theory, we must use PSU(N) bundle and lift configurations (critical points at infinity) for which there is no obstruction back to SU(N). These provide a refinement of instanton sums: integer topological charge, but crucially fractional action configurations contribute, providing a TQFT protected generalization of resurgent semi-classical expansion to strong coupling. Monopole-instantons (or fractional instantons) on T3 × {S}_L^1 can be interpreted as tunneling events in the ’t Hooft flux background in the PSU(N) bundle. The construction provides a new perspective to the strong coupling regime of QFTs and resolves a number of old standing issues, especially, fixes the conflicts between the large-N and instanton analysis. We derive the mass gap at θ = 0 and gaplessness at θ = π in mathbbm{CP} 1 model, and mass gap for arbitrary θ in mathbbm{CP} N−1, N ≥ 3 on ℝ2.

Double-pass shell-and-tube heat exchanger performance enhancement with new combined baffle and elliptical tube bundle arrangement

Optimization of shell-side fluid flow and heat transfer of heat exchangers could be done by reforming the baffle and tube bundle structures. In this study, a new arrangement of baffles and tube bundles in the operation of the shell-and-tube heat exchanger is investigated. In the present research, the effect of the segmental baffle (SB), single-pass helical baffle (SPHB), double-pass helical baffle (DPHB), and double-pass combined helical-segmental baffle (DPCHSB) accompanied with the various elliptical tube bundles were studied and compared. Various tube bundle arrangement effects such as vertical, horizontal, and angled were studied. The fluid domain was simulated by CFD Software (Solid work Flow Simulation). By comparing the evaluation characteristics such as Q/Δp, and the efficiency evaluation coefficient (EEC) for all proposed baffle and tube bundle configurations, the angled-elliptical tube bundles showed the best performance rather than other studied tube bundles layouts. For the SPHB, the angled-elliptical tube bundle improved the EEC by 20.9 and 10.7% rather than the horizontal-elliptical and vertical-elliptical tube bundle arrangement, respectively. For the DPHB, the EEC of angled-elliptical increased by 15.7 and 22.4% rather than the horizontal-elliptical and vertical-elliptical tube bundle arrangement, respectively. For the DPCHSB, the EEC of angled-elliptical enhanced 30.3 and 14.8% rather than horizontal-elliptical and vertical-elliptical arrangement, respectively.

Coupled porous media approaches in sub-channel CFD

In this paper, the porous media method is introduced into a recently developed Computational Fluid Dynamics (CFD)-based sub-channel analysis tool, Sub-Channel CFD (SubChCFD) through direct coupling to improve its capability in modelling complex structures, such as spacers or distorted fuel rod bundles. Two coupling methods have been developed, namely, embedding and interfacing coupling. The former is suitable for rod bundles with attached fine structures which do not change the basic geometry of the sub-channels, so a SubChCFD baseline model can be created based on the bare bundle configuration. Porous media sub-models can then be embedded in this model at locations where fine structures are installed to account for their influence on the flow and pressure drop. The interfacing method is more general and flexible, and used in a wider range of applications. In this method, separate meshes are used for the sub-domains where the porous media method is applied. These sub-domains are then interfaced with the domain covered by SubChCFD using a meshing joining technique and they are simulated together using a single set of governing equations. The methods developed are tested and validated with simulations of two rod bundle configurations, a 7 × 7 rod bundle with locally ballooned fuel rods and a 5 × 5 rod bundle equipped with simple support grids. It has been shown that a suitably selected method of the coupling can greatly simplify the modelling of complex structures using SubChCFD, thus providing additional flexibility and functionality to this newly developed CFD-based sub-channel framework.

The configurations of HRM bundles in MNCs by their contributions to subsidiaries’ performance and cultural dimensions

The main goal of the paper is to determine whether the HQs of MNCs evaluate the significances of particular HRM subfunctions to their foreign subsidiaries’ performance differently depending on a specific cultural context and—as a consequence—various configurations of HRM subfunctions may be identified in different cultural contexts. The theoretical assumptions are based on a combination of the configurational and contextual perspectives through a cross-cultural lens. In the empirical research an abductive reasoning process is applied. The research sample covers 200 headquarters of MNCs. To analyze the collected data both descriptive and correlational statistical methods are used. Two patterns of configurational bundle of HRM have been identified: A and B. Pattern A tends to be more system oriented and Pattern B more centralization oriented. Pattern A covers the subsidiaries which, with comparison to their HQ, are of lower power distance, higher individualism, higher masculinity, lower uncertainty avoidance, longer time orientation, and higher indulgence. Pattern B is composed of the subsidiaries with the opposite signs of the cultural distance index. The originality of the study consists in the application of the abductive research model. Thanks to it, we were able to search and find the simplest and most probable explanations for our observations. And the value of the research itself lies in the evidence that the contextual perspective with its configurational implications in the HRM research field is useful in identifying the phenomena that are difficult to identify or unidentifiable otherwise. The findings of the present study provide some knowledge on how cultural distance (external variable) and the significance of HRM to the subsidiary’s performance results (internal variable) interact in impacting on different configurational bundles of HRM subfunctions, their centralization practices and knowledge flows in MNCs.

Flagellar arrangements in elongated peritrichous bacteria: bundle formation and swimming properties

The surface distribution of flagella in peritrichous bacterial cells has been traditionally assumed to be random. Recently, the presence of a regular grid-like pattern of basal bodies has been suggested. Experimentally, the manipulation of the anchoring points of flagella in the cell membrane is difficult, and thus, elucidation of the consequences of a particular pattern on bacterial locomotion is challenging. We analyze the bundle formation process and swimming properties of Bacillus subtilis-like cells considering random, helical, and ring-like arrangements of flagella by means of mesoscale hydrodynamics simulations. Helical and ring patterns preferentially yield configurations with a single bundle, whereas configurations with no clear bundles are most likely for random anchoring. For any type of pattern, there is an almost equally low probability to form V-shaped bundle configurations with at least two bundles. Variation of the flagellum length yields a clear preference for a single major bundle in helical and ring patterns as soon as the flagellum length exceeds the body length. The average swimming speed of cells with a single or two bundles is rather similar, and approximately 50% larger than that of cells of other types of flagellar organization. Considering the various anchoring patterns, rings yield the smallest average swimming speed independent of the type of bundle, followed by helical arrangements, and largest speeds are observed for random anchoring. Hence, a regular pattern provides no advantage in terms of swimming speed compared to random anchoring of flagella, but yields more likely single-bundle configurations.Graphic abstract

Signal integrity analysis of bundled carbon nanotubes as futuristic on-chip interconnects

Rigorous technology scaling of integrated circuits to nanometer range aids to acquire prodigious operational speed and versatile functionality in system-on-chip. However, this leads to escalation in interconnect parasitics and non-ideal issues that have become primary bottleneck in the existing copper based on-chip interconnect system. Graphene based carbon nanotube bundle has emerged as prospective interconnect for high speed applications. This paper focuses on bundled carbon nanotubes and their different spatial arrangements viz. single wall CNTs (SWCNTs), multiwall CNTs (MWCNTs) and mixed CNT bundles (MCBs). Such bundle configurations boost the performance of system in terms of reducing system latency and power consumption in addition providing system reliability. The significant novel contribution of this paper lies in executing eye-diagram analysis of the futuristic bundled CNT structures as interconnects. Eye-diagram is an important tool for analysing signal integrity effects. The several performance analyses have been performed in SPICE and ADS EDA tools at 22 nm technology node.

Numerical simulation of the mechanical behavior of a carbon nanotube bundle

Due to their outstanding mechanical properties, carbon nanotubes (CNTs) are very promising materials for further applications in the field of lightweight construction. Carbon nanotube fibers, whose structure consists of a multitude of load-bearing carbon nanotube bundles interconnected by threads, are an excellent possibility to utilize these properties as engineering material. In the present research, a new method for the prediction of the mechanical properties of carbon nanotube bundles is presented. Within this, the complex structure is transformed into a simplified model based on suitable assumptions. Several parameters of the bundle are taken into account such as different types of nanotubes and various nanotube lengths. The model is applied to different configurations of carbon nanotube bundles by using a molecular mechanics approach. The interactions between the nanotubes are investigated by analyzing the Lennard–Jones potential in a virtual tensile loading test. For different configurations, the resulting forces and stresses are obtained. The results give a clear insight into the influencing parameters and demonstrate their effect on the mechanical behavior. In conclusion, the present approach is an excellent method to analyze the mechanical behavior of CNT bundles.

A New Capacitance Sensor for Measuring the Void Fraction of Two-Phase Flow Through Tube Bundles.

Evaluating the two-phase flow parameters across tube bundles is crucial to the analysis of vibration excitation mechanisms. These parameters include the temporal and local variation of void fraction and phase redistribution. Understanding these two-phase parameters is essential to evaluating the stability threshold of tube bundle configurations. In this work, capacitance sensor probes were designed using finite element analysis to ensure high sensor sensitivity and optimum response. A simulation-based approach was used to calibrate and increase the accuracy of the void fraction measurement. The simulation results were used to scale the normalized capacitance and minimize the sensor uncertainty to ±5%. The sensor and required conditioning circuits were fabricated and tested for measuring the instantaneous void fraction in a horizontal triangular tube bundle array under both static and dynamic two-phase flow conditions. The static calibration of the sensor was able to reduce the uncertainty to ±3% while the sensor conditioning circuit was able to capture instantaneous void fraction signals with frequencies up to 2.5 kHz.

Pulling Simulations and Hydrogen Sorption Modelling on Carbon Nanotube Bundles

Recent progress in molecular simulation technology has developed an interest in modernizing the usual computational methods and approaches. For instance, most of the theoretical work on hydrogen adsorption on carbon nanotubes was conducted a decade ago. It should be insightful to reinvestigate the field and take advantage of code improvements and features implemented in contemporary software. One example of such features is the pulling simulation modules now available in many molecular dynamics programs. We conduct pulling simulations on pairs of carbon nanotubes and measure the inter-tube distance before they dissociate in water. We use this distance to set the interval size between adjacent nanotubes as we arrange them in bundle configurations. We consider bundles with triangular, intermediate and honeycomb patterns, and armchair nanotubes with a chiral index from n = 5 to n = 10. Then, we simulate low pressure hydrogen adsorption isotherms at 77 K, using the grand canonical Monte Carlo method. The different bundle configurations adsorb great hydrogen amounts that may exceed 2% wt at ambient pressures. The computed hydrogen capacities are considered large for physisorption on carbon nanostructures and attributed to the ultra-microporous network and extraordinary high surface area of the configured models.

Mathematical Framework of Tetramorphic MWCNT Configuration for VLSI Interconnect

Having a 1D material like Multiwall Carbon Nanotube (MWCNT) as a potential candidate for high speed Very Large Scale Integration (VLSI) interconnect creates a good scope to reduce the delay by estimating the parasitic elements i.e. Resistance ( $R$ ), Inductance ( $L$ ) and Capacitance ( $C$ ) properly. We have contrived an innovative configuration namely Tetramorphic (TM) for the bundle of MWCNTs with four different diameters. We have focused on 45 nm, 22 nm, 11 nm and 7 nm technology nodes to justify the novelty of our proposed configuration over the existing MWCNT bundle configurations. Having the parasitic $RLC$ elements for a specific technology node, the diameter optimization took place in this work. Subsequently, we obtain the propagation delay results for local, semi-global and global level interconnect. Finally, we compare the results with the other existing configuration to show the supremacy of our introduced configuration for MWCNT bundle to explore high speed VLSI interconnect and represent crosstalk delay and power dissipation. Moreover, this configuration is highly dense which will offer the size shrinkage feature in a substantial manner.

Corona inception field of typical overhead line conductors under variable atmospheric conditions

Corona inception field of line conductors is of major importance for assessing corona performance of overhead transmission lines. Using computational models that consider the ionization processes in corona discharge, the corona inception field of ACSR conductors typically utilized in overhead transmission lines is estimated. The interactive effects of line conductor geometry, voltage polarity as well as atmospheric conditions on corona inception field are assessed and discussed based on the ionization area around the conductor. It is shown that the corona inception field of bundle configurations can be satisfactorily approximated by that of the subconductor when considered single. Generally, the inception field of negative corona is slightly lower than that of positive corona and lesser affected by variations in atmospheric conditions. An empirical expression for the straightforward estimation of the corona inception field of line conductors has been introduced, accounting well for the effects of conductor geometry, voltage polarity and atmospheric conditions.

Bundling, pricing schemes and extra features preferences for mobility as a service: Sequential portfolio choice experiment

Mobility as a Service (MaaS) represents an innovative solution expected to induce people abandoning their cars in favor of more sustainable ways of travelling. However, a precondition for the successful implementation and diffusion of MaaS is public acceptance. In this paper, the latent demand for MaaS is estimated using a choice model based on a stated preference survey, conducted in the Netherlands. Specifically, a sequential experimental design approach based on portfolio choice is developed. It consists of two steps aimed to investigate (i) individual intention to subscribe to MaaS and preferences for bundle configurations, (ii) willingness to pay for extra features of the service. This article reports results of the analysis of the first step of the experiment. Two different mixed logit models are estimated to capture unobserved heterogeneity in individual’s preferences. First, a binary mixed logit model is formulated to estimate the effect of service attributes, social influence, socio-demographics and transportation-related characteristics on the decision to subscribe. Then, a mixed logit model is formulated to analyze the effects of transportation mode pricing schemes, and cross effects between transportation modes and individual characteristics on the choice which transportation modes to include in the subscription. The estimation results indicate that, overall, respondents are not yet inclined to subscribe to this new service. The service attribute characteristics, especially the price of the monthly subscription, and the social influence variables have an important effect on the subscription intention. The results also show that public transportation is the most preferred transportation mode, revealing that it may play a key role in MaaS platforms. The decision to subscribe and the choice which transportation modes to include in the bundle, appear to be significantly related to socio-demographic profiles and individuals’ transportation-related characteristics. The findings can be used as a valuable source of information for transportation planners and policy makers.