Time dependent viscoelastic rheological response of pure, modified and synthetic bituminous binders

Bitumen is a viscoelastic material that exhibits both elastic and viscous components of response and displays both a temperature and time dependent relationship between applied stresses and resultant strains. In addition, as bitumen is responsible for the viscoelastic behaviour of all bituminous materials, it plays a dominant role in defining many of the aspects of asphalt road performance, such as strength and stiffness, permanent deformation and cracking. Although conventional bituminous materials perform satisfactorily in most highway pavement applications, there are situations that require the modification of the binder to enhance the properties of existing asphalt material. The best known form of modification is by means of polymer modification, traditionally used to improve the temperature and time susceptibility of bitumen. Tyre rubber modification is another form using recycled crumb tyre rubber to alter the properties of conventional bitumen. In addition, alternative binders (synthetic polymeric binders as well as renewable, environmental-friendly bio-binders) have entered the bitumen market over the last few years due to concerns over the continued availability of bitumen from current crudes and refinery processes. This paper provides a detailed rheological assessment, under both temperature and time regimes, of a range of conventional, modified and alternative binders in terms of the materials dynamic (oscillatory) viscoelastic response. The rheological results show the improved viscoelastic properties of polymer- and rubber-modified binders in terms of increased complex shear modulus and elastic response, particularly at high temperatures and low frequencies. The synthetic binders were found to demonstrate complex rheological behaviour relative to that seen for conventional bituminous binders

The ARID1B spectrum in 143 patients: from nonsyndromic intellectual disability to Coffin–Siris syndrome

Purpose: Pathogenic variants in ARID1B are one of the most frequent causes of intellectual disability (ID) as determined by large-scale exome sequencing studies. Most studies published thus far describe clinically diagnosed Coffin–Siris patients (ARID1B-CSS) and it is unclear whether these data are representative for patients identified through sequencing of unbiased ID cohorts (ARID1B-ID). We therefore sought to determine genotypic and phenotypic differences between ARID1B-ID and ARID1B-CSS. In parallel, we investigated the effect of different methods of phenotype reporting. Methods: Clinicians entered clinical data in an extensive web-based survey. Results: 79 ARID1B-CSS and 64 ARID1B-ID patients were included. CSS-associated dysmorphic features, such as thick eyebrows, long eyelashes, thick alae nasi, long and/or broad philtrum, small nails and small or absent fifth distal phalanx and hypertrichosis, were observed significantly more often (p < 0.001) in ARID1B-CSS patients. No other significant differences were identified. Conclusion: There are only minor differences between ARID1B-ID and ARID1B-CSS patients. ARID1B-related disorders seem to consist of a spectrum, and patients should be managed similarly. We demonstrated that data collection methods without an explicit option to report the absence of a feature (such as most Human Phenotype Ontology-based methods) tended to underestimate gene-related features

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Evaluation of geologic structure guiding ground water flow south and west of Frenchman Flat, Nevada Test Site

Ground water flow through the region south and west of Frenchman Flat, in the Ash Meadows subbasin of the Death Valley ground water flow system, is controlled mostly by the distribution of permeable and impermeable rocks. Geologic structures such as faults are instrumental in arranging the distribution of the aquifer and aquitard rock units. Most permeability is in fractures caused by faulting in carbonate rocks. Large faults are more likely to reach the potentiometric surface about 325 meters below the ground surface and are more likely to effect the flow path than small faults. Thus field work concentrated on identifying large faults, especially where they cut carbonate rocks. Small faults, however, may develop as much permeability as large faults. Faults that are penetrative and are part of an anastomosing fault zone are particularly important. The overall pattern of faults and joints at the ground surface in the Spotted and Specter Ranges is an indication of the fracture system at the depth of the water table. Most of the faults in these ranges are west-southwest-striking, high-angle faults, 100 to 3500 meters long, with 10 to 300 /meters of displacement. Many of them, such as those in the Spotted Range and Rock Valley are left-lateral strike-slip faults that are conjugate to the NW-striking right-lateral faults of the Las Vegas Valley shear zone. These faults control the ground water flow path, which runs west-southwest beneath the Spotted Range, Mercury Valley and the Specter Range. The Specter Range thrust is a significant geologic structure with respect to ground water flow. This regional thrust fault emplaces siliceous clastic strata into the north central and western parts of the Specter Range

Evaluation of faults and their effect on ground-water flow southwest of Frenchman Flat, Nye and Clark Counties, Nevada

Ground-water flow through the region south and west of Frenchman Flat, in the Ash Meadows subbasin of the Death Valley ground-water flow system, is controlled mostly by faults which arrange the distribution of permeable and impermeable rocks. In addition, most permeability is along fractures caused by faulting in carbonate rocks. Large faults are more likely to reach the potentiometric surface as deep as 325 meters below the ground surface and are more likely to effect the flow path than small faults. This study concentrated on identifying large faults, especially where they cut carbonate rocks. Small faults, however, may develop as much permeability as large faults if they are penetrative and are part of an anastomosing fault zone. The overall pattern of faults and joints at the ground surface in the Spotted and Specter Ranges is an indication of the fracture system at the depth of the water table. Most of the faults in these ranges are west-southwest-striking high-angle faults, 100 to 3,500 meters long, with 10 to 300 meters of displacement. Many of them, such a those in the Spotted Range and Rock Valley are left-lateral strike-slip faults that are conjugate to the NW-striking right-lateral faults of the Las Vegas Valley shear zone. These faults control the ground-water flow path, which runs west-southwest beneath the Spotted Range, Mercury Valley, and the Specter Range. The Specter Range thrust is a significant geologic structure with respect to ground-water flow. This regional thrust fault emplaces siliceous clastic strata into the north-central and western parts of the Specter Range. These rocks act as a barrier that confines ground-water flow to the southern part of the range, directing it southwestward toward springs at Ash Meadows. These siliceous clastic aquitard rocks and overlying Cenozoic deposits probably also block westward flow of ground water in Rock Valley, diverting it southward to the flow path beneath the southern part of Specter Range

Compilation of Unpublished USGS and University of Arizona K-Ar Dates of Volcanic Rocks of the San Francisco Volcanic Field, Northern Arizona

This compilation reports 174 K-Ar dates from the San Francisco Volcanic Field in northern Arizona. Of these dates, 112 are from the US Geological Survey in Menlo Park, California, and 62 are from the Laboratory of Isotope Geochemistry at the Department of Geosciences, University of Arizona. Most of these dates have not been previously published and none are in the compilation by Reynolds and others (1986). Those that have been published have not included analytical data. Some of these dates have not been released because, for various reasons, it seemed likely that they did not accurately represent rock age. Dates reported here have all been recalculated using lUGS decay and abundance constants (Table 1; Steiger and Jager, 1977; see also Dalrymple, 1979). Potassium was measured by flame photometry using a lithium internal standard. Uncertainty in potassium analysis is either sample standard deviation or 0.5%, whichever is greater. Uncertainty of date, representing one standard deviation, was calculated by the method of Cox and Dalrymple (1967) assuming a standard deviation of 0.3 % for tracer calibration.Documents in the AZGS Document Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact [email protected]

Improvement of parenteral nutrition-associated cholestasis in an adult using fish oil-based parenteral nutrition

Parenteral nutrition-associated cholestasis (PNAC) is a severe complication of parenteral nutrition. Standard feed preparations contain soybean and olive oil that are rich in ω-6 polyunsaturated fats, and which studies suggest can be hepatotoxic. Preparations containing fish oil, rich in ω-3 polyunsaturated fats, may be hepatoprotective and have been used in the critical care setting as immunotherapy. A case demonstrating dramatic improvement in liver function and overall clinical condition in an adult with PNAC and intestinal failure within 8 weeks of changing to a fish oil-based parenteral feed is reported. As far as is known, this is the first report of an adult patient whose parenteral nutrition-associated liver disease resolved after a parenteral nutrition lipid emulsion was changed to the fish oil-containing emulsion, SMOFlipid