Mechanistic pavement design procedures based on elastic layer theory require characterization of all pavement layer materials including subgrade soil. This paper discusses the subgrade stiffness obtained from a new compaction device called the Intelligent Compaction (IC) roller on highway embankment projects in Kansas. Three test sections on two routes were compacted using a single, smooth stee...

The yield of rainfed crops is commonly limited by the availability of soil water during the summer growing season. Channels produced by cover crop roots in fall/winter when soils are relatively moist may facilitate the penetration of compacted soils by subsequent crop roots in summer when soils are relatively dry and hard. Our objective was to determine the effects of fall cover crops on maize ...

BACKGROUND Condensin is thought to contribute to large-scale DNA compaction during mitotic chromosome assembly. It remains unknown, however, how the complex reconfigures DNA structure at a mechanistic level. RESULTS We have performed single-molecule DNA nanomanipulation experiments to directly measure in real-time DNA compaction by the Xenopus laevis condensin I complex. Condensin can bind to...

Bone remodeling is a localized process, but regulated by systemic signals such as hormones, cytokines, and mechanical loading. The mechanism by which bone cells convert these systemic signals into local signals is not completely understood. It is broadly accepted that the "prestress" in cytoskeleton of cells affects the magnitude of cellular responses to mechanical stimuli. Prestress derives fr...

The complications of impaction bone grafting in revision hip replacement includes fracture of the femur and subsidence of the prosthesis. In this in vitro study we aimed to investigate whether the use of vibration, combined with a perforated tamp during the compaction of morsellised allograft would reduce peak loads and hoop strains in the femur as a surrogate marker of the risk of fracture and...

Issue: The moisture content of a fill material will affect its compaction characteristics and needs to be evaluated during quality control of the fill operation. When the fill is drier than its optimum moisture content, any moisture in the fill serves as a lubricant and helps the relative movement of the particles when densifying under vibratory compaction. When the fill is wetter than its opti...

In the cyanobacterium Synechococcus elongatus (PCC 7942) the kai genes A, B, and C and the sasA gene encode the functional protein core of the timing mechanism essential for circadian clock regulation of global gene expression. The Kai proteins comprise the central timing mechanism, and the sensor kinase SasA is a primary transducer of temporal information. We demonstrate that the circadian clo...

Tillage studies have shown that maximum, tillage-induced, aggregate breakdown occurs near the optimum water content on a Proctor compaction curve for the soil. Many soil databases do not contain Proctor data; therefore, prediction equations were developed to estimate the optimum water content, peak Proctor dry bulk density, and the Proctor compaction curve for a soil based on common intrinsic p...

Warm compaction takes advantage of temperature to favor densification during compaction. However, this technique requires powder mixes with specific physical characteristics to be adequately processed in the temperature range involved in warm pressing. The mix formulation, especially the lubricant/binder system, should provide good flowability and compressibility and lubrication of the die wall...