Roofing Materials

Describes some of the many materials and systems available for residential roofing, typical application details and some of the problems encountered. Included are properties of roofing types, including shingles and rolled roofing, and selection of materials

Brick and Concrete Masonry

Describes the various materials used in brick and concrete masonry construction: some of the more common masonry systems, and the details that go into making rna onry walls strong durable and weather-resistant

Site blocking effects on adsorbed polyacrylamide conformation

The use of polymers as flocculating additives is a common practice in many manufacturing environments. However, exactly how these polymers interact with surfaces is relatively unknown. One specific topic which is thought to be very important to flocculation is an adsorbed polymer's conformation. Substantial amounts of previous work, mainly using simulations, have been performed to elucidate the theory surrounding adsorbed polymer conformations. Yet, there is little experimental work which directly verifies current theory. In order to optimize the use of polymer flocculants in industrial applications, a better understanding of an adsorbed polymer's conformation on a surface beyond theoretical simulations is necessary. This work looks specifically at site blocking, which has a broad impact on flocculation, adsorption, and surface modification, and investigated its effects on the resulting adsorbed polymer conformation. Experimental methods which would allow direct determination of adsorbed polymer conformational details and be comparable with previous experimental results were first determined or developed. Characterization of an adsorbed polymer's conformation was then evaluated using dynamic light scattering, a currently accepted experimental technique to examine this. This commonly used technique was performed to allow the comparison of this works results with past literature. Next, a new technique using atomic force microscopy was developed, building on previous experimental techniques, to allow the direct determination of an adsorbed polymer's loop lengths. This method also was able to quantify changes in the length of adsorbed polymer tails. Finally, mesoscopic simulation was attempted using dissipative particle dynamics. In order to determine more information about an adsorbed polymer's conformation, three different environmental factors were analyzed: an adsorbed polymer on a surface in water, an adsorbed polymer on a surface in aqueous solutions of varying ionic strength, and an adsorbed polymer on a surface functionalized with site blocking additives. This work investigated these scenarios using a low charge density high molecular weight cationic polyacrylamide. Three different substrates, for polymer adsorption were analyzed: mica, anionic latex, and glass. It was determined that, similar to previous studies, the adsorbed polymer layer thickness in water is relatively small even for high molecular weight polymers, on the order of tens of nanometers. The loop length distribution of a single polymer, experimentally verified for the first time, revealed a broad span of loop lengths as high as 1.5 microns. However, the bulk of the distribution was found between 40 and 260 nanometers. For the first time, previous theoretical predictions regarding the salt effect on adsorbed polymer conformation were confirmed experimentally. It was determined that the adsorbed polymer layer thickness expanded with increasing ionic strength of the solvent. Using atomic force microscopy, it was determined that the adsorbed polymer loop lengths and tail lengths increased with increasing ionic strength, supporting the results found using dynamic light scattering. The effect of the addition of site blocking additives on a single polymer's conformation was investigated for the first time. It was determined that the addition of site blocking additives caused strikingly similar results as the addition of salt to the medium. The changes in an adsorbed polymer's loop lengths was found to be inconsistent and minimal. However, the changes in an adsorbed polymer's free tail length was found to increase with increasing site blocking additive levels. These results were obtained using either PDADMAC or cationic nanosilica as site blocking additives.Ph.D.Committee Chair: Yulin Deng; Committee Co-Chair: Peter Ludovice; Committee Member: James Frederick; Committee Member: Lawrence Bottomley; Committee Member: Preet Sing

Helpful Resouces for Family Caregivers

Formerly published under the HE seriesFS-68

The End of Angkor? The Modification and Re-use of Angkor Wat

Angkor Wat, the largest religious monument in the world, was built in the mid 12th century AD and has been continuously occupied ever since. Angkor Wat was the jewel in the crown of Greater Angkor, the capital of the Khmer Empire. Over 800 years have passed since its construction and during this long period the context of Angkor Wat and Greater Angkor has changed significantly. Once the capital of the Khmer Empire, in the 15th and 16th centuries as the apparatus of the state moved to the Southeast, Greater Angkor came to be on the periphery of the Khmer world. In a similar manner, as Khmer society changed, the originally Vaisnavite temple Angkor Wat came to be hallowed by Theravada Buddhist monks. Throughout these political and social changes Angkor Wat itself has changed – the temple features modifications which postdate the original construction phase. The fourth enclosure wall is one such component which has undergone several modifications. The wall, which clearly demonstrates more than one construction phase, is covered in several thousand postholes. The postholes, which are located along the upper part of the inside face and on top of the wall, have never been studied before. This thesis seeks to answer two questions: 1) What was the purpose of the postholes?, and 2) When were the postholes made? To answer these questions the postholes were surveyed. The results of a detailed survey show that the distribution of and relationship between the postholes is consistent over a considerable distance. The relationship between the postholes and the construction phases of the wall establishes a relative chronology. The nature of the modifications to the wall and the location of the postholes indicate that they were supports for the framework of a defensive platform and palisade. The absolute date of these defensive works is as yet unknown, however the likely historical context suggests they were installed sometime between the late 16th century and the early 17th century AD

The End of Angkor? The Modification and Re-use of Angkor Wat

Angkor Wat, the largest religious monument in the world, was built in the mid 12th century AD and has been continuously occupied ever since. Angkor Wat was the jewel in the crown of Greater Angkor, the capital of the Khmer Empire. Over 800 years have passed since its construction and during this long period the context of Angkor Wat and Greater Angkor has changed significantly. Once the capital of the Khmer Empire, in the 15th and 16th centuries as the apparatus of the state moved to the Southeast, Greater Angkor came to be on the periphery of the Khmer world. In a similar manner, as Khmer society changed, the originally Vaisnavite temple Angkor Wat came to be hallowed by Theravada Buddhist monks. Throughout these political and social changes Angkor Wat itself has changed – the temple features modifications which postdate the original construction phase. The fourth enclosure wall is one such component which has undergone several modifications. The wall, which clearly demonstrates more than one construction phase, is covered in several thousand postholes. The postholes, which are located along the upper part of the inside face and on top of the wall, have never been studied before. This thesis seeks to answer two questions: 1) What was the purpose of the postholes?, and 2) When were the postholes made? To answer these questions the postholes were surveyed. The results of a detailed survey show that the distribution of and relationship between the postholes is consistent over a considerable distance. The relationship between the postholes and the construction phases of the wall establishes a relative chronology. The nature of the modifications to the wall and the location of the postholes indicate that they were supports for the framework of a defensive platform and palisade. The absolute date of these defensive works is as yet unknown, however the likely historical context suggests they were installed sometime between the late 16th century and the early 17th century AD

The Effect of Varying Environmental Conditions on Phytolith Morphometries in Two Species of Grass (Bouteloua curtipendula and Panicum virgatum)

Solid deposits of SiO2 (phytoliths) accumulate in many plants in specific intracellular and extracellular locations. Phytoliths have morphological characteristics unique to some taxa and therefore have taxonomic significance. Phytoliths persist and maintain their morphological integrity long after a plant has died, thus becoming a microfossil of the plant that produced them. Development of phytolith sytematics for microfossil phytoliths has traditionally followed a typological approach based on simple verbal descriptions of shape. A new method for use in phytolith sytematics is the morphometric approach which employs computer-based Image Analysis Systems to make quantified measurements of morphological parameters (size, shape, texture, etc.) which can be used as discriminators between taxa. These parameters, called morphometrics, or morphometries, are potentially important for improved phytolith sytematics. This study evaluates the effect of varying environmental conditions on 18 different phytolith morphometries relative to shape and size as a prerequisite to the further development of a morphometric based phytolith taxonomy. Results indicate that environmental conditions do indeed effect phytolith morphometries for the silica cell phytoliths produced by the two grass species considered in this study. However, the effects are not usually significant (p ≤ 0.05). Moreover, results of discriminant analyses using the morphometric data obtained indicate that the varying environmental conditions did not hinder the potential of phytolith morphometries to discriminate between plant taxa

Reaching Fathers in Parent Education: Perceptions of Newsletter Value Among Fathers and Father Figures

Does parent education pay attention to fathers and their perceptions of educational resources? Not often enough. The NDSU Extension Service developed a parenting newsletter for fathers of young children--Father Times. Findings focused on how fathers of children in kindergarten perceive and value the newsletter as a resource. Results showed that fathers: (1) appreciated the layout, readability, and usefulness of the newsletter; (2) valued the newsletter more highly than other formal sources of information; and (3) indicated the features and topics most valuable to them. A newsletter for fathers can be a unique resource for reaching fathers in parent education

Older Adult Knowledge and Behavior Change in the Stepping On Fall Prevention Program in a Community Setting

One out of every three Americans age 65 and over falls at least once annually. Fall-related injuries among older adults are a major public health concern, and prevention of falls has emerged as a key issue in avoiding the risks to mobility and health that exist due to falls. Stepping On is an evidence-based fall prevention program designed to help older adults take control of their fall risk factors, explore different behavioral steps, and reduce their fall risk. This study shares findings from evaluation efforts conducted with 182 older adult participants in Stepping On from 2013 to 2015. Older adults in the program demonstrated (1) high satisfaction with program quality; (2) positive impacts on knowledge related to fall risk factors and prevention; and (3) substantial followthrough on behavioral steps designed to minimize fall risk. Program participants also shared positive feedback on the program in response to open-ended questions. Implications of the findings for fall risk reduction and programs to enhance fall prevention among older adults are discussed. Programs designed to reduce fall risk factors and enhance quality of life can be a critical tool to assist older adults, educators, and community leaders in addressing this public health issue