Intelligent compaction (IC) procedures have been gaining popularity as a way to measure mechanistic soil material properties (e.g. stiffness) during the compaction process for earthwork projects. IC ...procedures involve the interpretation of roller measured soil stiffness from vibratory roller drum accelerations and offer an advantage over current spot testing methods, as IC provides real-time continuous feedback during the compaction process and 100% test coverage of the earthwork site. The objective of this study is to provide the first detailed analysis of IC field data from vibratory roller compaction of layered soil systems. The interpretation of roller measured soil stiffness is currently ambiguous for two main reasons: (1) IC vibratory rollers provide a composite measure of soil stiffness in layered earthwork situations and (2) roller measured soil stiffness from edge mounted (EM) accelerometers can vary significantly due to rocking motion of the drum. To investigate these issues, left and right EM acceleration data from a vibratory roller are used to compute a composite roller measured soil stiffness at the center of gravity (CG) of the drum. CG soil stiffness, which is not subject to the variations associated with drum rocking, are used to evaluate data from two field sites with multiple 15 – 30 cm thick base/subbase/subgrade lifts to investigate their sensitivities to variable lift materials and thicknesses. CG soil stiffness increases with the addition of subbase and base lifts, showing sensitivity to changes in soil materials. CG soil stiffness also increases with the addition of multiple base lifts, showing sensitivity to an increase in the overall thickness of the base material. CG soil stiffness is not sensitive to small variations in the subbase and base lift thicknesses, showing CG soil stiffness is sensitive to the addition of 15 – 30 cm thick subbase and base lifts but not the small variations in lift thickness associated with each of these lifts.
The authors' reply Brannon, Ernest L.; Collins, Keya M.; Brown, John S. ...
Environmental toxicology and chemistry,
July 2008, Volume:
27, Issue:
7
Journal Article
The authors' reply Brannon, Ernest L.; Collins, Keya M.; Brown, John S. ...
Environmental toxicology and chemistry,
07/2008, Volume:
27, Issue:
7
Journal Article
The authors' reply Brannon, Ernest L.; Collins, Keya M.; Brown, John S. ...
Environmental toxicology and chemistry,
07/2008, Volume:
27, Issue:
7
Journal Article
This paper reports on the results of weathering studies conducted on four light crude oils from production platforms on the northwest shelf of Australia. The laboratory weathering included both ...evaporative weathering and emulsification studies. The fresh oils and their topped residues were subjected to a battery of physical and chemical characterization analyses. Detailed analyses were performed for
n-alkanes by GC/FID and for mono- and polycyclic aromatic hydrocarbons and phenols by GC/MS. The water-in-oil emulsion formation properties of these oils and their topped residues were investigated at two environmentally significant temperatures (13 and 20°C). The results of the analyses indicate that these oils are very different compositionally and have a wide range of physical and chemical properties. The emulsification properties of these oils and their weathered residues ranged from oils that have very rapid water uptake to oils having no water uptake. Unexpectedly, the very waxy oils had very little water uptake and did not form stable water-in-oil emulsions.
Abstract Purpose 1. Describe the presentation, imaging, and outcome of two cases of paraganglioma of the facial canal at our institution. 2. Summarize existing literature to better understand this ...lesion. 3. Clarify terminology. Methods Retrospective chart review at single tertiary academic referral center. Literature review using the PubMed electronic database. Results There are 12 cases of histologically-proven paraganglioma of the facial canal published in the English literature. We present two additional cases that were encountered at our institution. We also include three additional cases from a separate institution that have been accepted for publication in a different journal. We found that patients most commonly present with slowly progressive facial paralysis; though paralysis can be acute. The second most common symptom was pulsatile tinnitus, which was the only symptom in one patient. Radiographically, tumor location was in the descending segment in all but one case. The mass was often centered directly over the stylomastoid foramen, mimicking a parotid mass. We found circumferential widening of the proximal fallopian canal, and a “moth-eaten” bony destruction distally on CT imaging in several patients. In patients with poor facial nerve function (HB IV-VI), complete tumor removal with nerve sacrifice followed by great auricular or sural nerve grafting was performed with acceptable facial function results. Conclusions Paraganglioma of the facial canal remains a rare etiology of progressive facial paralysis. The lesions are found in the distal descending segment, or centered over the stylomastoid foramen 94% of the time. In patients with poor facial function, surgical removal with nerve sacrifice, followed by great auricular or sural nerve grafting, yields an acceptable functional result.
Technology and Youth Sampson Lee Blair, Patricia Neff Claster, Samuel M. Claster
2015, 2015-10-06, Volume:
19
eBook
This volume focuses on the theme of Technology and Youth; advancements in communication and leisure technologies over the past decade have radically transformed the role of technology in the lives of ...youth. Around the globe, children and adolescents are often seen as being the first to embrace new technologies, such as new forms of social media. Having a cell phone, once regarded as an adult technology, has become a necessity within youth culture in many societies. Even video games, once limited to stand-alone computers, have become a venue for social gatherings of youth. The rapid pace of technological advancement has brought about profound changes in the very nature of childhood and adolescence.This volume of examines the role of technology in the lives of children and adolescents. Topics addressed include: cyberbullying, video games and aggressive behavior, online gaming and the development of social skills, sexuality, child pornography, virtual communities for children, social networking and peer relations, and other related issues.
