The road surface quality can be assessed with ride comfort indices because of their strong correlation. Many studies on ride comfort have focused on cars and trucks, but their results are not applicable to buses, which are characterised by inherently different vehicle dynamics. In this study, a quarter-vehicle simulation concept was used to develop a Bus Ride Index (BRI) for evaluating the effect of road irregularities on bus ride comfort. A BRI model was developed to optimise ride comfort depending on seat configuration and air suspension and validated according to technical data. The results show a good regression relationship between BRI and the International Roughness Index (IRI). New IRI thresholds with regard to ride comfort and bus operating speeds were established to serve as a benchmark to develop better pavement maintenance strategies for bus lanes and to estimate road quality based on acceleration data.

The Bolton's analysis and Pont's analysis are very useful calculations for orthodontic diagnosis. In Nepal, there is no study about Bolton's and Pont's analysis. So here we examined 100 Nepalese subjects all subjects were with molar and canine class I relationship. We have measured the model to establish a normative standard of Bolton's OR and AR for Nepalese population and to find the reliability of Pont's index for Nepalese, and to comparing them between Caucasian and Chinese. The normative value on OR of Nepalese was found to be 91.22% with a standard deviation of 1.99 and AR was 78.04% with standard deviation of 2.72. The normative standard of OR for Nepalese is similar to that obtained by Bolton for Caucasian and that of Chinese, but the normative standard of AR obtained for Nepalese is significantly different than that obtained by Bolton for Caucasian and also that of Chinese. The correlation coefficient between the measured arch width values and the corresponding calculated values according to Pont's indexes were low in all cases with r values ranging from 0.07 to 0.29. Pont's Index is not reliable for predetermination of ideal arch width values for Nepalese.

BackgroundTo assess the anatomy of the mandibular buccal shelf (MBS) with cone-beam computed tomography (CBCT) and to identify the region of miniscrew implantation for the distalization of mandibular dentition.Materials and methodsThe MBS was assessed in 80 patients at four regions as follows: (i) between the buccal root of the mandibular second premolar and the mesiobuccal root of the first molar (L5b–L6mb), (ii) between the mesiodistal root of the first molar (L6mb–L6db), (iii) between the distobuccal root of the first molar and the mesiobuccal root of the second molar (L6db–L7mb), and (iv) between the mesiodistal roots of the second molar (L7mb–L7db). The buccal alveolar bone thickness, the narrowest inter-radicular space at the buccal side of the roots, and the distance between the implantation site and the mandibular neural tube were measured at horizontal planes of 3, 5, 7, and 9 mm from the alveolar crest.ResultsThe buccal alveolar bone thickness increased from the premolar to the molar and from the crest edge to the mandibular roots. The L7mb–L7db region had the thickest buccal alveolar bone of 7.61 mm at a plane of 9 mm. The buccal inter-radicular spaces were smallest in the L7mb–L7db region and greatest in the L6db–L7mb region. The distances from the implantation site to the mandibular neural tube at planes of 3, 5, 7, and 9 mm were all > 13 mm from the L6 region to the L7 region.ConclusionsThe L6db–L7mb region should be the first choice for miniscrew implantation in the MBS for the distalization of mandibular dentition.

Downloaded by [George Mason University] at 03:24 05 June 2016 2Up to now more than fourteen subway lines are in operation and some new lines are being built in the coastal city, Shanghai. The longitudinal settlement of shield tunnel has significant effect on the safety of the subway operation. In this paper, the deformation of the shield tunnel and the surrounding soil were analyzed by the establishment of a three-dimensional model. The vertical displacements of four paths (Path 1 is on the ground; Path 2 is at the top of tunnel; Path 3 is in the middle of tunnel; Path 4 is on the bottom of tunnel) are affected by the nature of the soil. The horizontal displacement is smaller than the vertical displacement and horizontal displacement of the clay is larger than that of the sand. The distribution of the pore pressure changes with soil properties around the tunnel. The pore pressure of the sand layer is larger than that of the clay layer at the same depth of underlying soil.

The long-term settlement of a subway tunnel, especially the differential settlement affects the safe operation of the subway. In this article, the settlement of a subway tunnel was studied from the theoretical and numerical analyses based on the monitoring data. According to the monitoring data, the deformation of segments at different locations is different, and the deformation around a channel is larger than other places. The settlements of tunnel calculated by two theoretical methods are consistent with that obtained in the centrifuge model test. The numerical simulation indicates that the vertical displacement is much bigger than the horizontal displacement.