Investigation of fiber/matrix adhesion: test speed and specimen shape effects in the cylinder test

The cylinder test, developed from the microdroplet test, was adapted to assess the interfacial adhesion strength between fiber and matrix. The sensitivity of cylinder test to pull-out speed and specimen geometry was measured. It was established that the effect of test speed can be described as a superposition of two opposite, simultaneous effects which have been modeled mathematically by fitting two parameter Weibull curves on the measured datas. Effects of the cylinder size and its geometrical relation on the measured strength values have been analyzed by finite element method. It was concluded that the geometry has a direct influence on the stress formation. Based on the results achieved, recommendations were given on how to perform the novel single fiber cylinder test

Characterizing Sleep Spindles in Sheep.

Sleep spindles are distinctive transient patterns of brain activity that typically occur during non-rapid eye movement (NREM) sleep in humans and other mammals. Thought to be important for the consolidation of learning, they may also be useful for indicating the progression of aging and neurodegenerative diseases. The aim of this study was to characterize sleep spindles in sheep (Ovis aries). We recorded electroencephalographs wirelessly from six sheep over a continuous period containing 2 nights and a day. We detected and characterized spindles using an automated algorithm. We found that sheep sleep spindles fell within the classical range seen in humans (10-16 Hz), but we did not see a further separation into fast and slow bands. Spindles were detected predominantly during NREM sleep. Spindle characteristics (frequency, duration, density, topography) varied between individuals, but were similar within individuals between nights. Spindles that occurred during NREM sleep in daytime were indistinguishable from those found during NREM sleep at night. Surprisingly, we also detected numerous spindle-like events during unequivocal periods of wake during the day. These events were mainly local (detected at single sites), and their characteristics differed from spindles detected during sleep. These "wake spindles" are likely to be events that are commonly categorized as "spontaneous alpha activity" during wake. We speculate that wake and sleep spindles are generated via different mechanisms, and that wake spindles play a role in cognitive processes that occur during the daytime

Abnormally abrupt transitions from sleep-to-wake in Huntington's disease sheep (Ovis aries) are revealed by automated analysis of sleep/wake transition dynamics.

Sleep disturbance is a common and disruptive symptom of neurodegenerative diseases such as Alzheimer's and Huntington's disease (HD). In HD patients, sleep fragmentation appears at an early stage of disease, although features of the earliest sleep abnormalities in presymptomatic HD are not fully established. Here we used novel automated analysis of quantitative electroencephalography to study transitions between wake and non-rapid eye movement sleep in a sheep model of presymptomatic HD. We found that while the number of transitions between sleep and wake were similar in normal and HD sheep, the dynamics of transitions from sleep-to-wake differed markedly between genotypes. Rather than the gradual changes in EEG power that occurs during transitioning from sleep-to-wake in normal sheep, transition into wake was abrupt in HD sheep. Furthermore, transitions to wake in normal sheep were preceded by a significant reduction in slow wave power, whereas in HD sheep this prior reduction in slow wave power was far less pronounced. This suggests an impaired ability to prepare for waking in HD sheep. The abruptness of awakenings may also have potential to disrupt sleep-dependent processes if they are interrupted in an untimely and disjointed manner. We propose that not only could these abnormal dynamics of sleep transitions be useful as an early biomarker of HD, but also that our novel methodology would be useful for studying transition dynamics in other sleep disorders

Hydro-sedimentological Monitoring and Analysis for Material Sites on the Sagavanirktok River

Researchers from the Water and Environmental Research Center at the Institute of Northern Engineering, University of Alaska Fairbanks, are conducting a research project related to sediment transport conditions along the Sagavanirktok River. This report presents tasks conducted from summer 2015 to early winter 2016. Four hydrometeorological stations were installed in early July 2015 on the west bank of the river. The stations are spread out over a reach of approximately 90 miles along the Dalton Highway (from MP 405, the northernmost location, to MP 318, the southernmost location). These stations are equipped with pressure transducers and with air temperature, relative humidity, wind speed, wind direction, barometric pressure, and turbidity sensors. Cameras were installed at each station, and automatic water samplers were deployed during the open-water season. The stations have a telemetry system that allows for transmitting data in near-real time. Discharge measurements were performed three times: twice in July (early and late in the month), and once in mid-September. Measured discharges were in the order of 100 m3/s, indicating that measurements were performed during low flows. Suspended sediment concentrations ranged from 2 mg/l (nearly clear water) to 625 mg/l. The average grain size for suspended sediment from selected samples was 47.8 μm, which corresponds to silt. Vegetation was characterized at 27 plots near the stations. Measurements of basic water quality parameters, performed during winter, indicated no potential issues at the sampled locations. Dry and wet pits were excavated in the vicinity of each station. These trenches will be used to estimate average bedload sediment transport during spring breakup 2016. A change detection analysis of the period 1985–2007 along the area of interest revealed that during the present study period, the river was relatively stable.ABSTRACT ..................................................................................................................................... i LIST OF FIGURES ....................................................................................................................... iv LIST OF TABLES ......................................................................................................................... vi ACKNOWLEDGMENTS ............................................................................................................ vii DISCLAIMER .............................................................................................................................. vii CONVERSION FACTORS, UNITS, WATER QUALITY UNITS, VERTICAL AND HORIZONTAL DATUM, ABBREVIATIONS, AND SYMBOLS ........................................... viii ABBREVIATIONS, ACRONYMS, AND SYMBOLS ................................................................. x 1 INTRODUCTION AND STUDY AREA ............................................................................... 1 2 METHODOLOGY AND EQUIPMENT .............................................................................. 11 2.1 Pit Trenches .................................................................................................................... 12 2.2 Meteorology ................................................................................................................... 13 2.3 Water Level Measurements ............................................................................................ 13 2.4 Runoff............................................................................................................................. 14 2.5 Suspended Sediment ...................................................................................................... 15 2.6 Turbidity ......................................................................................................................... 15 2.7 Substrate and Floodplain Vegetation Survey ................................................................. 16 2.7.1 Site selection ........................................................................................................... 16 2.7.2 Quantifying substrate .............................................................................................. 16 2.7.3 Characterizing vegetation ....................................................................................... 17 3 RESULTS .............................................................................................................................. 19 3.1 Pit Trench Configuration ................................................................................................ 19 3.2 Meteorology ................................................................................................................... 27 3.3 Water Level Observations .............................................................................................. 27 3.4 Runoff............................................................................................................................. 31 3.4.1 Additional runoff observations ............................................................................... 31 3.5 Suspended Sediment ...................................................................................................... 32 3.6 Suspended Sediment Grain-Size Distribution ................................................................ 34 3.7 Turbidity ......................................................................................................................... 35 3.8 Water Quality ................................................................................................................. 37 4 ANALYSIS ........................................................................................................................... 39 4.1 Substrate and Vegetation ................................................................................................ 39 4.1.1 Substrate .................................................................................................................. 39 iii 4.1.2 Vegetation ............................................................................................................... 40 4.2 River Channel Stability .................................................................................................. 42 5 CONCLUSIONS ................................................................................................................... 56 6 REFERENCES ...................................................................................................................... 58 7 APPENDICES ....................................................................................................................... 6

Sagavanirktok River Spring Breakup Observations 2016

In 2015, spring breakup on the Sagavanirktok River near Deadhorse was characterized by high flows that destroyed extensive sections of the Dalton Highway, closing the road for nearly 3 weeks. This unprecedented flood also damaged infrastructure that supports the trans-Alaska pipeline, though the pipeline itself was not damaged. The Alaska Department of Transportation and Public Facilities (ADOT&PF) and the Alyeska Pipeline Service Company made emergency repairs to their respective infrastructure. In December 2015, aufeis accumulation was observed by ADOT&PF personnel. In January 2016, a research team with the University of Alaska Fairbanks began monitoring and researching the aufeis and local hydroclimatology. Project objectives included determining ice elevations, identifying possible water sources, establishing surface meteorological conditions prior to breakup, measuring hydrosedimentological conditions (discharge, water level, and suspended sediment concentration) during breakup, and reviewing historical imagery of the aufeis feature. Ice surface elevations were surveyed with Global Positioning System (GPS) techniques in late February and again in mid-April, and measureable volume changes were calculated. However, river ice thickness obtained from boreholes near Milepost 394 (MP394) in late February and mid-April revealed no significant changes. It appears that flood mitigation efforts by ADOT&PF in the area contributed to limited vertical growth in ice at the boreholes. End-of-winter snow surveys throughout the watershed indicate normal or below normal snow water equivalents (SWE 10 cm). An imagery analysis of the lower Sagavanirktok aufeis from late winter for the past 17 years shows the presence of ice historically at the MP393–MP396 area. Water levels and discharge were relatively low in 2016 compared with 2015. The mild breakup in 2016 seems to have been due to temperatures dropping below freezing after the flow began. Spring 2015 was characterized by warm temperatures throughout the basin during breakup, which produced the high flows that destroyed sections of the Dalton Highway. A comparison of water levels at the East Bank Station during 2015 and 2016 indicates that the 2015 maximum water level was approximately 1 m above the 2016 maximum water level. ii Maximum measured discharge in 2016 was approximately half of that measured in 2015 in the lower Sagavanirktok River. Representative suspended sediment sizes (D50) ranged from 20 to 50 microns (medium to coarse silt). An objective of this study was to determine the composition and possible sources of water in the aufeis at the lower Sagavanirktok River. During the winter months and prior to breakup in 2016, overflow water was collected, primarily near the location of the aufeis, but also at upriver locations. Simultaneously possible contributing water sources were sampled between January and July 2016, including snow, glacial meltwater, and river water. Geochemical analyses were performed on all samples. It was found that the overflow water which forms the lower Sagavanirktok aufeis is most similar (R2 = 0.997) to the water that forms the aufeis at the Sagavanirktok River headwaters (Ivishak River), thought to be fed by relatively consistent groundwater sources.ABSTRACT ..................................................................................................................................... i LIST OF FIGURES ........................................................................................................................ v LIST OF TABLES ......................................................................................................................... ix ACKNOWLEDGMENTS AND DISCLAIMER ........................................................................... x CONVERSION FACTORS, UNITS, WATER QUALITY UNITS, VERTICAL AND HORIZONTAL DATUM, ABBREVIATIONS, AND SYMBOLS ............................................. xi ABBREVIATIONS, ACRONYMS, AND SYMBOLS .............................................................. xiii 1 INTRODUCTION ................................................................................................................... 1 2 STUDY AREA ........................................................................................................................ 6 3 METHODOLOGY AND EQUIPMENT ................................................................................ 6 3.1 Aufeis Extent .................................................................................................................... 7 3.1.1 Field Methods ........................................................................................................... 7 3.1.2 Structure from Motion Imagery ................................................................................ 8 3.1.3 Imagery ..................................................................................................................... 8 3.2 Surface Meteorology ...................................................................................................... 10 3.3 Water Levels .................................................................................................................. 11 3.4 Discharge Measurements ............................................................................................... 13 3.5 Suspended Sediment ...................................................................................................... 16 3.6 Water Chemistry ............................................................................................................ 17 3.6.1 Sampling ................................................................................................................. 17 3.6.2 Trace Element Analysis .......................................................................................... 19 3.6.3 Data Analysis .......................................................................................................... 19 4 RESULTS .............................................................................................................................. 20 4.1 Air Temperature ............................................................................................................. 20 4.2 Wind Speed and Direction ............................................................................................. 29 4.3 Annual Precipitation ....................................................................................................... 30 4.4 Cold Season Precipitation .............................................................................................. 32 4.5 Warm Season Precipitation ............................................................................................ 36 4.6 Aufeis Extent .................................................................................................................. 40 4.6.1 Historical Aufeis at Franklin Bluffs ........................................................................ 40 4.6.2 Delineating Ice Surface Elevation with GPS and Aerial Imagery .......................... 46 4.6.3 Ice Boreholes .......................................................................................................... 55 iv 4.6.4 Ice Accumulation (SR50) ....................................................................................... 58 4.6.5 Ice Thickness and Volume ...................................................................................... 60 4.7 Surface Water Hydrology............................................................................................... 62 4.7.1 Sagavanirktok River at MP318 (DSS4) .................................................................. 67 4.7.2 Sagavanirktok River at Happy Valley (DSS3) ....................................................... 70 4.7.3 Sagavanirktok River Below the Ivishak River (DSS2)........................................... 73 4.7.4 Sagavanirktok River at East Bank (DSS5) Near Franklin Bluffs ........................... 76 4.7.5 Sagavanirktok River at MP405 (DSS1) West Channel .......................................... 85 4.7.6 Additional Field Observations ................................................................................ 86 4.8 Suspended Sediment ...................................................................................................... 87 4.9 Water Chemistry ............................................................................................................ 91 5 CONCLUSIONS ................................................................................................................... 96 6 REFERENCES ...................................................................................................................... 99 7 APPENDICES ..................................................................................................................... 10

The efficacy of two bupivacaine hydrochloride injection products

No Abstract