Thermosetting polymer-matrix composites for structural repair applications

Several classes of thermosetting polymer matrix composites were evaluated for use in structural repair applications. Initial work involved the characterization and evaluation of woven carbon fiber/epoxy matrix composites for structural pipeline repair. Cyanate ester resins were evaluated as a replacement for epoxy in composites for high-temperature pipe repair applications, and as the basis for adhesives for resin infusion repair of high-temperature composite materials. Carbon fiber/cyanate ester matrix composites and fumed silica/cyanate ester nanocomposites were evaluated for their thermal, mechanical, viscoelastic, and rheological properties as they relate to their structure, chemistry, and processing characteristics. The bisphenol E cyanate ester under investigation possesses a high glass transition temperature, excellent mechanical properties, and unique ambient temperature processability. The incorporation of fumed silica served to enhance the mechanical and rheological properties of the polymer and reduce thermal expansion without sacrificing glass transition or drastically altering curing kinetics. Characterization of the composites included dynamic mechanical analysis, thermomechanical analysis, differential scanning calorimetry, thermogravimetric analysis, rheological and rheokinetic evaluation, and transmission electron microscopy

Impact of configuration variations on small modular reactor core performance

One of the most promising new reactor designs is the Small Modular Reactor (SMR). These reactors, which operate under 300 MWe, will help bring cheap and safe nuclear energy to remote and centralized locations alike. Their ease of construction, advanced passive safety features, and cost effectiveness make these reactors an intriguing option for the near future. In the work presented here, a neutronics analysis of the Westinghouse SMR was performed. Westinghouse\u27s SMR design is a scaled down version of their AP1000 plant and will produce about 225 MWe of power. Though the parameters of the reactor core will be modeled after the AP1000, the exact layout of the core has not been released. For this research project, six initial core configurations have been proposed. The Monte Carlo method was used to calculate several reactor parameters by means of the MCNP6 code. Beginning of life calculations such as effective multiplication factor, delayed neutron fraction, temperature coefficients of reactivity, and neutron flux profile have been performed. Three refueling cycles have then been completed to observe how the six cores perform within the cycle up to the point when an equilibrium fuel cycle has been reached, while extracting data pertaining to multiplication factor, burnup, composition of spent fuel, and flux profile. These calculations will help to determine the feasibility and the effectiveness of the six potential core configurations. --Abstract, page iii

Visual and Expressive Form Qualities Attainable in Thrown Pottery Vessels by Use of Various Lips and Feet

It was the purpose of this study to discover the number of various form qualities that it is possible to achieve within pottery vessels that are closely related by similar feet, bodies, and lips. The variety of form qualities sought for were of a visual nature; the entire pot seeming to appear more or less vertical or more or less horizontal than others with the same type of body but with different shapes of lips and feet selected to be used

A chapter in the history of Orange County, Virginia

In 1753 Orange County could hardly have still been oalled a frontier region, but its society remained like that of the more exposed communities to the west for some time. It was neither overpopulated nor was the land intensively cultivated. The flora and fauna had hardly been affected, and wolves frequently howling at night reminded the inhabitants that the job of taming their environment was yet unfinished. These wolves were suffi­ ciently destruotive to demand bounties, and many farmers, planters and. gentlemen eked out their income by presenting the head of a wolf to the sheriff, who paid a hundred pounds of tobacco for the trophy

A system of industrialized housing for developing countries

Thesis (M.Arch)--Massachusetts Institute of Technology, Dept. of Architecture, 1962.Accompanying drawings held by MIT Museum.Includes bibliographical references (leaves 30-31).by William Kirby Lockard.M.Arc

The Golden Dog (Le Chien D\u27or)

https://commons.und.edu/settler-literature/1139/thumbnail.jp

Up to D[eb]ate on Raising and Control, Part 2: The Empirical Range of the Constructions and Research on their Acquistion

This is the second part of a two-part article that reviews a number of the current debates regarding raising and control constructions. The issues addressed in this part include the spectrum of related raising (e.g. possessor raising, further raising) and control (partial, split, generic, super-equi) phenomena; cross-linguistic typology, including backward and copy constructions; and their acquisition in child language

Young people's views on accelerometer use in physical activity research : findings from a user involvement investigation

The use of accelerometers to objectively measure physical activity is important in understanding young people's behaviours, as physical activity plays a key part in obesity prevention and treatment. A user-involvement qualitative study with young people aged 7–18years (n = 35) was carried out to investigate views on accelerometer use to inform an obesity treatment research study. First impressions were often negative, with issues related to size and comfort reported. Unwanted attention from wearing an accelerometer and bullying risk were also noted. Other disadvantages included feeling embarrassed and not being able to wear the device for certain activities. Positive aspects included feeling "special" and having increased attention from friends. Views on the best time to wear accelerometers were mixed. Advice was offered on how to make accelerometers more appealing, including presenting them in a positive way, using a clip rather than elastic belt to attach, personalising the device, and having feedback on activity levels. Judgements over the way in which accelerometers are used should be made at the study development stage and based on the individual population. In particular, introducing accelerometers in a clear and positive way is important. Including a trial wearing period, considering practical issues, and providing incentives may help increase compliance

Pacific Southwest United States Holocene Droughts and Pluvials Inferred From Sediment δ18O (calcite) and Grain Size Data (Lake Elsinore, California)

Records of past climate can inform us on the natural range and mechanisms of climate change. In the arid Pacific southwestern United States (PSW), which includes southern California, there exist a variety of Holocene records that can be used to infer past winter conditions (moisture and/or temperature). Holocene records of summer climate, however, are rare from the PSW. In the future, climate changes due to anthropogenic forcing are expected to increase the severity of drought in the already water stressed PSW. Hot droughts are of considerable concern as summer temperatures rise. As a result, understanding how summer conditions changed in the past is critical to understanding future predictions under varied climate forcings. Here, we present a c. 10.9 kcal BP δ18O(calcite) record from Lake Elsinore, California, interpreted to reflect δ18O(lake water) values as controlled by over-water evaporation from summer-to-early fall. Our results reveal three millennial scale intervals: (1) the highly evaporative Early Holocene (10.55–6.65 kcal BP), (2) the less evaporative Mid-Holocene (6.65–2.65 kcal BP); and (3) the evaporative Late Holocene (2.65–0.55 kcal BP). These results are coupled with an inferred winter precipitation runoff (sand content) record from Kirby et al. (2010). Using these data together, we estimate the duration and severity of centennial-scale Holocene droughts and pluvials (e.g., high δ18O(calcite) values plus low sand content = drought and vice versa). Furthermore, the coupled δ18O(calcite) and sand data provide a generalized Holocene lake level history. The most severe, long-lasting droughts (i.e., maximum summer-to-early fall evaporation and minimum winter precipitation runoff) occur in the Early Holocene. Fewer, less severe, and shorter duration droughts occurred during the Mid-Holocene as pluvials became more common. Droughts return with less severity and duration in the Late Holocene. Notably, the Little Ice Age is characterized as the wettest period during the Late Holocene