F(1)-ATPase is an ATP-driven rotary molecular motor in which the central gamma-subunit rotates inside the cylinder made of alpha(3)beta(3) subunits. The amino and carboxy termini of the gamma-subunit form the axle, an alpha-helical coiled coil that deeply penetrates the stator cylinder. We previously truncated the axle step by step, starting with the longer carboxy terminus and then cutting bot...

Increasing axle loads of today’s North American heavy haul freight trains have presented numerous engineering challenges for the design and performance of concrete crossties and fastening systems. Several research studies have been conducted to understand the path of the vertical load from the wheel/rail interface through the fastening system and into the crosstie with successful results. Howev...

soil compaction can occur as a result of a number of factors. one of the most important factors is soil response to pressures imposed by wheels and soil engaging tools. this research investigated the effect of tyre load and inflation pressure on soil compaction-related factors. these factors include rut width, rut depth, cone index and horizontal force in different layers of soil profile. in th...

In the framework of an ongoing national research project involving the University of Minho, the National Laboratory of Civil Engineering and the New University of Lisbon, different commercial FEM codes (DIANA, PLAXIS and ANSYS) were tested to model the dynamic performance of a high speed train track. Initially a plain strain model is considered in a robin test using experimental data from a wel...

Texas currently has approximately 17,000 miles of load-zoned roads, the majority of which are posted at 58,420 lbs. These roads consist predominantly of thin pavement structures constructed in the 1940s and 1950s, originally designed to carry the lighter loads of those times. In 1989, the 71st Texas Legislature passed House Bill 2060 (HB 2060), which established a $75-per-county permit that all...

T total cost of moving goods by truck over a highway system involves two basic compon~nts: -the public costs associated with construction and maintenance of the road network, and the privately financed costs of acquiring, operating, and maintaining a fleet of trucks. These publicly and privately financed costs are directly linked in many ways. For instance, the more trucks there are, the more w...

This paper presents a probabilistic load model for fatigue assessment of old metallic railway bridges. The traffic basis of the model consists of trains obtained from past records and present-day trains obtained from codes. The traffic is divided into four distinct time periods each associated with particular characteristics in rail traffic. Traffic evolution scenarios for the future, in terms ...

This study determined the effect of system tilt angle (STA) and seat-to-backrest angle (SBA) changes on the load sustained by the shoulder during manual wheelchair propulsion. Fourteen elderly participants (mean +/- standard deviation age 68.2 +/- 5.2 years) were recruited. Combinations of three STAs (0 degrees , 5 degrees , and 10 degrees ) and three SBAs (95 degrees , 100 degrees , and 105 de...