The peptidoglycan layer of Vitreoscilla stercoraria, ATCC 15218, was isolated from intact cells after treatment with sodium lauryl sulfate (SLS) and digestion with Pronase. Amino acid and amino sugar content was analyzed and 67% of the total present was made up of glutamic acid, alanine, diaminopimelic acid (DAP), and glucosamine in a molar ratio of 1:1.7:1:0.7. Electron microscopy of the final peptidoglycan product showed a thin, delicately folded sacculus which exhibited a morphology different from that of the intact vegetative cells. Within these sacculi occurred electron-dense structures which were assayed and found to be poly- 3-hydroxybutyrate (PHB) granules. The final yield of peptidoglycan was 2.9% of the dry weight of the intact vegetative cell.

The purpose of this study was to extract galvanized steel wire reinforcement coupons from mechanically stabilized earth (MSE) walls along I-15 and determine the rate of corrosion that has taken place since Phase I, which was conducted by Gerber and Billings (2010). The galvanized steel reinforcement analyzed in this study has been in place for 19 to 20 years at the time of extraction. A total of 85 coupons were extracted and laboratory analysis was performed to determine the thickness of remaining zinc galvanization on each coupon. Soil samples were obtained from each one-stage wall extraction location to determine moisture content for correlation with corrosion. After laboratory testing was performed, the measured zinc coating thickness was compared to that determined in Phase I. An average corrosion rate of approximately 0.032 oz/ft²/year has occurred since Phase I. According to the AASHTO (2017) design corrosion rate of 0.35 oz/ft²/year for the first two years and 0.09 oz/ft²/year until the depletion of the zinc, the zinc coating would have been completely depleted after 16 years. Based on the results of laboratory testing, the initial galvanization coating was likely greater than the specified thickness of 2.0 oz/ft² (86 μm). The zinc galvanization is corroding at a slower rate than the AASHTO design rate. The AASHTO design rate for depletion of zinc coating and subsequent corrosion of the steel reinforcement is conservative for the corrosion conditions present in the MSE wall reinforcement coupons tested. The integrity of the steel reinforcement that is currently in place is not likely to be compromised by corrosion.

Well-detailed reinforced concrete (RC) shear walls did not achieve the expected seismic performance in the 2011 Christchurch earthquake as per the Canterbury earthquake royal commission report. Similarly, RC shear walls showed low seismic performance in the 2010 Maule earthquake. The two major seismic events intrigued this research dissertation, where six half-scaled RC shear walls were constructed and tested. The six walls were split into two phases, each phase had different end configurations (i.e., rectangular, flanged, and boundary elements). Phase II RC walls had 2.4 times the vertical reinforcement ratio of Phase I walls. The walls were detailed as per CSA A23.3-19, and they were tested laterally under a quasi-static cyclic fully-reversed loading while maintaining a constant axial load through the full test of the walls. The overall seismic performance of the six walls is evaluated in Chapters 2 and 3 in terms of their load-displacement relationships, crack patterns, displacement ductility capacities, stiffness degradation trends, curvature profiles, end strains, energy dissipation capabilities, and equivalent viscous damping ratios. In addition, damage states are specified according to the Federal Emergency Management Assessment (FEMA P58) guidelines. The results came in agreement with the Canterbury earthquake royal commission report, where the test walls with low vertical reinforcement ratios showed lower-than-expected seismic performance due to the concentration of their plastic hinges at the primary crack locations. Moreover, the results validated the Christchurch (2011) and Maule (2010) earthquake findings as concentrating the rebars at the end zones and providing adequate confinement enhanced the seismic performance of the test walls, which was the case for Phase II flanged and boundary element walls. The displacement ductility variations of the test walls inspired the work of Chapter 4, where the objective is to develop a data-driven expression for RC shear walls to better quantify their displacement ductility capacities. In this respect, an analytical model is developed and experimentally validated using several RC walls. The analytical model is then used to generate a dataset of RC walls with a wide range of geometrical configurations and design parameters, including cross-sectional properties, aspect ratios, axial loads, vertical reinforcement ratio, and concrete compressive strengths. This dataset is utilized to develop two data-driven prediction expressions for the displacement ductility of RC walls with rectangular and flanged/boundary element end configurations. The developed data-driven expressions accurately predicted the displacement ductility of such walls and they should be adopted by relevant building codes and design standards, instead of assigning a single ductility-related modification factor for all ductile RC shear walls, as per the 2020 National Building Code of Canada. Several researchers tested well-detailed Reinforced Masonry (RM) shear walls and the results concluded that RM shear walls showed high seismic performance similar to that of RC shear walls. This intrigued the research efforts presented in Chapter 5, where a comparative analysis is performed between the six RC walls tested in this dissertation and three RM walls tested in a previous experimental program. The analysis focuses on comparing the seismic performance of both wall systems in terms of their crack patterns, load-displacement envelopes, curvature profiles, displacement ductility, normalized periods, and equivalent viscous damping ratios. In addition, an economic assessment is performed to compare such RC and RM shear walls using their total rebar weights and the total construction costs. Overall, RM shear walls achieved an acceptable seismic performance coupled with low rebar weights and low construction costs when compared to their RC counterparts. / Thesis / Doctor of Philosophy (PhD)

The idea of tilt-up construction started in America in the early I900’s. In the beginning, this technique was mainly used on structures such as industrial warehouses and factories. However, recent developments and improvements in tilt-up construction technique and accessories have enabled this building method to be applied to many architecturally appealing offices and residential structures. There are many details the design-build team must consider to ensure the success of a tilt-up project. The floor slab must be designed for panel casting and to withstand the loading of the mobile crane which will be used to lift the panel. The crane capacity affects the panel size and weight. Proper curing and bondbreaker application are very important to reduce bonding and to ensure clear cleavage between concrete surfaces. Changing rigging configuration consumes expensive crane time and must be reduced to minimum possible. The availability of ground-release quick connect/disconnect tilt—up hardware improves workers safety and speeds up the erection process substantially. Although the stress analysis of simple wall panels during erection can be done by hand, panels with more complicated geometry or with openings, are more efficiently analysed with a computer. Many manufacturers have technical services to help in the design of insert layout so that the concrete will not be over stressed when the panel is tilted into position. After the panel is plumbed, it is braced temporarily before the final connection is made. For in-place loading there are now design aids available which ease the design process. When properly designed and built, tilt—up has proved to be a fast, efficient, and economical building construction technique. / Master of Science

Pile-supported T-walls, which are concrete floodwalls that are shaped like an inverted "T" and supported by batter piles, are commonly used by the United States Army Corps of Engineers (USACE) to protect low-lying portions of New Orleans and other areas. The design of a T-wall in southern Louisiana is complex, as the structure needs to resist both 1) large settlements caused by fill placed beneath and beside the T-wall before T-wall construction or by fill placed beside the T-wall after T-wall construction, and 2) large lateral flood loads that are imposed during a hurricane. As a result of these loading conditions, large bending moments can develop in the batter piles and these moments need to be accounted for as part of the T wall design. The goal of this research is to develop a more complete understanding of the pile bending moments in T wall systems, specifically for cross sections where large settlements may occur. As a first step towards this goal, Rensselaer Polytechnic Institute (RPI) performed a series of eight centrifuge tests to investigate and physically model the effects of settlement-induced bending moments on pile-supported T-walls. The centrifuge tests were evaluated and interpreted, and in order to better capture uncertainty, upper and lower bounds were estimated for the interpreted data. The centrifuge results offered some valuable insights on their own, but were ultimately used as the basis for validating and calibrating corresponding numerical models. The numerical models were developed following a rigorous modeling approach and using rational and reasonable assumptions based on widely-accepted and well-justified procedures. The numerical model results were in good agreement with the centrifuge results without the need for significant calibration or modifications. This good agreement indicates that similar numerical models can be developed to reliably analyze actual T-wall cross sections. Detailed recommendations were developed for using numerical models to analyze pile-supported T walls, and an example problem is presented herein that illustrates the application of this approach. These same techniques were then used to perform a parametric study to analyze the combined and separate effects of flood loading for a wide range of different T-wall cross sections. The range was selected in collaboration with the USACE in order to reasonably cover cross sections and conditions that 1) are typically encountered in practice, and 2) were expected to generate both upper and lower bound pile bending moments. In total, 3,648 cross sections were analyzed, and 29,184 sets of analysis results were generated since each cross section was analyzed for eight different loading conditions. Summary results are provided to show the influence of the loading conditions and parameters on T-wall response, including the influence of flood loading, new fill symmetry, pile fixity, number of piles, subsurface profile, pile batter, pile type, levee slope, T-wall elevation, and the presence of existing levee fill. In addition, the key results for all of the analyses are provided in the appendices and in an electronic database. Based on the parametric study results, a simplified analysis procedure was developed that can be used to calculated maximum pile bending moments for T walls installed directly on foundation soils due to settlements. In this procedure, the loads from new fill placed during or after T-wall construction are distributed onto the pile, and the pile response is analyzed using traditional p-y curves and a beam on elastic foundation formulation. This procedure shows good agreement with the numerical model results for a range of conditions. To demonstrate the application of the procedure, the same example problem that is analyzed numerically is reanalyzed using the simplified analysis procedure. Due to the complexity of the problem, it was not possible to modify this procedure or develop a similar procedure for T-walls installed on top of new or existing levees. Overall, this research demonstrates that numerical models can be used to calculate the bending moments that can develop in pile-supported T-walls due to settlements and flood loading, provides valuable insights into the behavior of T-walls and the influence of various parameters on T-wall response, presents a large database of T-wall analysis results, and recommends a simplified analysis procedure that can be used in some cases to calculate pile bending moments due to settlements. / Ph. D.

Syfte: En långsam utveckling av levande väggar i Sverige beror bland annat på bristande erfarenhet och kunskap inom byggbranschen. Tidigare studier visar bland annat utmaningar gällande teknikens anpassning till ett svenskt klimat och ett krävande underhåll beroende av kompetens, planering och samverkan. Målet med studien är att analysera ett hållbart underhåll utifrån teknik och underhållsplanering av systemet levande väggar för att kunna besvara dessa problem. Metod: Studien är av kvalitativ karaktär där använda metoder är dokumentanalys, intervju och observation. Dokumentanalys ger en lägesbild av implementerade lösningar i södra Sverige och strategier för underhållsplanering. Intervju med relevanta aktörer bidrar med erfarenheter om teknik, underhåll och planering. Observation bekräftar information om teknik. Resultat: Studien visar på att ingen av de studerade konstruktionslösningarna kan anses fullständigt hållbara, men det finns systemlösningar som har mer eller mindre hållbara egenskaper. Levande väggar har starka sociala och ekologiska fördelar, där växtligheten bidrar till att öka ekosystemtjänsterna i urban miljö. En mindre resursanvändning är nödvändig för en hållbar teknik, där naturlig bevattning, lokala tåliga växter, varaktig konstruktion samt återvunna materialkomponenter främjar hållbar miljö och ekonomi. Filtdukssystem är enklare i design medan modulsystem är mer flexibelt. Ett gemensamt mål bland studerade projekt är att skapa ett så underhållsfritt system som möjligt där väggen får leva på naturlig väg. Acceptans för vilande växter under vinterhalvåret kan sänka krav på underhållet. Teknisk övervakning underlättar men manuell tillsyn är vital för väggens överlevnad. Frekvensen på underhållet varierar från projekt till projekt där kundens önskemål, placering, typ av vägg, storlek, växtval och årstid påverkar. Därför är det viktigt med planering och kontinuerlig utvärdering av behov. Majoriteten av studerade projekt har ingen tydlig underhållplanering, men studien visar på framgångar av ett tydligt gemensamt mål, tidig involvering av driftpersonal, platsanalys, målinriktad underhållsplan och erfarenhetsåterkoppling. Konsekvenser: Studiens slutsats är att tekniken för levande väggar behöver utvecklas för att för att lämna ett mindre fotavtryck på miljö och ekonomi. Utvecklingen går mot ett så underhållsfritt system som möjligt, men den manuella tillsynen kan inte ersättas helt av avancerad teknik. Varje anläggnings unika förutsättningar kräver noggrann planering och kontinuerlig utvärdering av behov. Begränsningar: Studien behandlar levande väggar i ett svenskt urbant klimat, där resultatet baseras på erfarenheter från projekt utförda i södra Sverige. Annan geografisk placering skapar andra förutsättningar för teknik och underhåll. Mer generella antaganden kan göras gällande underhållsplanering. Fler intervjuer med underhållstekniker kan bidra med andra aspekter i analysen. / Purpose: A slow development of living walls in Sweden is partly due to lack of experience and knowledge in the construction industry. Former studies point at challenges of adapting the technique in a Swedish climate and the importance of planning, knowledge and cooperation for the maintenance. The objective of the study is to analyse a sustainable maintenance by technique and maintenance planning of the system living walls in order to answer these challenges.   Method: The study is based on a qualitative approach where the methods are document analysis, interview and observation. Document analysis gives a status report of the implemented living walls in Sweden and introduces strategies for maintenance planning. Interview with relevant participants contributes with experiences concerning technique, maintenance and maintenance planning. Observation confirms the information about the technique. Findings: The study shows that none of the observed solutions can be considered completely sustainable, though they do have some sustainable qualities. Living walls have strong social and ecological benefits, where the vegetation contributes to increase ecosystem services in urban environment. A less use of resources is necessary for a sustainable technique where the use of stormwater, local resistant plants, lasting construction and recycled components promotes a sustainable environment and economy. The felt system is simpler in its design while the modular system is more flexible. A common objective among the observed projects is to create a maintenance-free solution as possible. Acceptance for resting plants during winter can lower the demands of the maintenance. Technical monitoring facilitates the maintenance but the manual handling of living walls is crucial. The frequency of the maintenance varies from each project where the client’s choice, placement of the wall, type of solution, size, plant choice and season affect. Therefore, it is important with planning and constantly evaluating a walls needs. The majority of the observed projects do not have a maintenance plan but the study shows success by a common objective, site analysis, goal-oriented maintenance plan and experience feedback. Implications: The conclusion of the study is that the technique of living walls needs to be evolved to leave a smaller footprint on the environment and the economy. The development is towards a maintenance-free solution but the manual handling can not be replaced by advanced technique. Every projects individual conditions demands thorough planning and continuous evaluation of the wall. Limitations: The study discuss living walls in the Swedish urban climate, where the result is based on experiences from projects developed in the southern part of Sweden. Other geographical placement causes different conditions for technique and maintenance. General assumptions can be made concerning the maintenance planning. More interviews with maintenance staff can contribute with other aspects to the analysis.

Design of retaining structures depends upon the load which is transferred from backfill soil as well as external loads and also the resisting capacity of the structure. The traditional safety factor approach of the design of retaining structures does not address the variability of soils and loads. The properties of backfill soil are inherently variable and influence the design decisions considerably. A rational procedure for the design of retaining structures needs to explicitly consider variability, as they may cause significant changes in the performance and stability assessment. Reliability based design enables identification and separation of different variabilities in loading and resistance and recommends reliability indices to ensure the margin of safety based on probability theory. Detailed studies in this area are limited and the work presented in the dissertation on the Optimum design of retaining structures under static and seismic conditions: A reliability based approach is an attempt in this direction. This thesis contains ten chapters including Chapter 1 which provides a general introduction regarding the contents of the thesis and Chapter 2 presents a detailed review of literature regarding static and seismic design of retaining structures and highlights the importance of consideration of variability in the optimum design and leads to scope of the investigation. Targeted stability is formulated as optimization problem in the framework of target reliability based design optimization (TRBDO) and presented in Chapter 3. In Chapter 4, TRBDO approach for cantilever sheet pile walls and anchored cantilever sheet pile walls penetrating sandy and clayey soils is developed. Design penetration depth and section modulus for the various anchor pulls are obtained considering the failure criteria (rotational, sliding, and flexural failure modes) as well as variability in the back fill soil properties, soil-steel pile interface friction angle, depth of the water table, total depth of embedment, yield strength of steel, section modulus of sheet pile and anchor pull. The stability of reinforced concrete gravity, cantilever and L-shaped retaining walls in static conditions is examined in the context of reliability based design optimization and results are presented in Chapter 5 considering failure modes viz. overturning, sliding, eccentricity, bearing, shear and moment failures in the base slab and stem of wall. Optimum wall proportions are proposed for different coefficients of variation of friction angle of the backfill soil and cohesion of the foundation soil corresponding to different values of component as well as lower bounds of system reliability indices. Chapter 6 presents an approach to obtain seismic passive resistance behind gravity walls using composite curved rupture surface considering limit equilibrium method of analysis with the pseudo-dynamic approach. The study is extended to obtain the rotational and sliding displacements of gravity retaining walls under passive condition when subjected to sinusoidal nature of earthquake loading. Chapter 7 focuses on the reliability based design of gravity retaining wall when subjected to passive condition during earthquakes. Reliability analysis is performed for two modes of failure namely rotation of the wall about its heel and sliding of the wall on its base are considering variabilities associated with characteristics of earthquake ground motions, geometric proportions of wall, backfill soil and foundation soil properties. The studies reported in Chapter 8 and Chapter 9 present a method to evaluate reliability for external as well as internal stability of reinforced soil structures (RSS) using reliability based design optimization in the framework of pseudo static and pseudo dynamic methods respectively. The optimum length of reinforcement needed to maintain the stability against four modes of failure (sliding, overturning, eccentricity and bearing) by taking into account the variabilities associated with the properties of reinforced backfill, retained backfill, foundation soil, tensile strength and length of the geosynthetic reinforcement by targeting various component and system reliability indices is computed. Finally, Chapter 10 contains the important conclusions, along with scope for further work in the area. It is hoped that the methodology and conclusions presented in this study will be beneficial to the geotechnical engineering community in particular and society as a whole.

This master´s thesis is focused on suitable design of a new nursery school building. Nursery school is situated in suburban area, and as such two level design was chosen. The building has U shape outline. Ground floor is intended for basic operation of the nursery school, while the second floor is designed to accommodate various extra-curricular activities. Foundations of the building are made of plain concrete. Porotherm system is used for all walling. Ceilings are made of precast hollow core slabs - Spiroll. Object is covered with a flat roof.

Cell walls of Bacillus subtilis macrofibers have been biochemically analyzed to determine the contribution of various surface polymers in the twist regulation. Helix hand inversion was induced by a variation in either the growth temperature or the nutritional composition of the culture medium. Initial experiments had demonstrated a fivefold difference in the sensitivity of right- and left-handed forms to muramidases indicating modifications of peptidoglycan as a possible mechanism underlaying inversion. An examination of lysozyme susceptibility of purified cell walls and whole cells derived from the two structural forms, however, exhibited no significant difference suggesting loss of the relevant component(s), perhaps biomechanical in nature, during disintegration of macrofibers. The effect of various twist modulators such as trypsin, ammonium sulfate and D-alanine on the development of helical twist in both switchable and "fixed" mutants were studied. The interaction matrices have established D-alanine as the most potent of right-factors. Intestinal alkaline phosphatase is reported as a newly discovered antagonist to the development of leftward twist. Heat inactivation and protein purification experiments strongly indicated that twist modulation was due to the phosphatase activity rather than minor protease contaminants. The chemical composition of cell walls purified from right- and left-handed structures was determined. No twist correlated differences in the overall content of peptidoglycan, teichoic acid and teichuronic acid were detected. Evidence is presented for the absence of correlation between the extent of ester-linked alanine substitution and twist state. These findings suggest that gross changes in wall composition is perhaps not the mechanism for hand inversion. From the profiles of the wall associated proteins, a 200 Kdal band has been identified whose presence is strongly correlated with the development of leftward twist. This polypeptide was found to be highly sensitive to trypsin; a property it shares with a previously proposed left-twist protein. Preliminary evidence for isolation of left-hand specific polyclonal antibodies is also presented. FJ7, a switchable mutant, was successfully transformed with a plasmid containing the Streptococcus transposon Tn917. A small bank of insertional mutants has been constructed for the isolation of mutants impaired in helix hand inversion.

I have explored the combination of sound, textile and space. How can one create textiles to use as sound dampening material in an arts and craft practice? To enhance the architectural aspect of textile as one of the five building materials I have chosen to weave walls. Walls don´t have to be straight or go from floor to ceiling but they should somehow create room and divide the space. I felt the need of walls working within Konstfack because of the distraction of fellow students in the open space classroom. Torn walls tells a story, we see the left traces. These traces I wanted to convert into woven textile. Sounds of people and objects in public spaces bounces between hard surfaces often without dampening, this creates an environment that causes stress and distraction. In Virginia Wolf´s essay “A room of Ones Own” (1929) she points at how important it is to create a workspace for the professional you, to take place and be part of the public realm. A big part of this master project has been making the actual materials to build with and executing fibre. Does the material do the job of sound absorption? Wool and silk both have a fibrous cell, which is suitable for sound absorption they also have low flammability and is biodegradable; therefore I chose to work mainly with these fibres. I share my knowledge through the experience of the space I create. How to create o Room of one´s own in an open office.