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Land-cover change in Cuba and implications for the area of distribution of a specialist's host-plant
No full textChanges in land cover directly affect biodiversity. Here, we assessed land-cover change in Cuba in the past 35 years and analyzed how this change may affect the distribution of plants and moths. We analyzed the vegetation cover of the Cuban archipelago for 1985 and 2020. We used Google Earth Engine to classify two satellite image compositions into seven cover types: forest and shrubs, mangrove, soil without vegetation cover, wetlands, pine forest, agriculture, and water bodies. We considered four different areas for quantifications of land-cover change: (1) Cuban archipelago, (2) protected areas, (3) areas of potential distribution of , and (4) areas of potential distribution of the plant within the protected areas. We found that "forest and shrubs", which is cover type in which populations have been reported, has increased significantly in Cuba in the past 35 years, and that most of the gained forest and shrub areas were agricultural land in the past. This same pattern was observed in the areas of potential distribution of ; whereas almost all cover types were mostly stable inside the protected areas. The transformation of agricultural areas into forest and shrubs could represent an interesting opportunity for biodiversity conservation in Cuba. Other detailed studies about biodiversity composition in areas of forest and shrubs gain would greatly benefit our understanding of the value of such areas for conservation
Deformation Capacity of Reinforced Concrete Column-to-Foundation Connections with Anchorage/Breakout Failures
No full textResults from these tests can be found at this reference:
Neupane, U., Niyonyungu, F., Lequesne, R. D., Lepage, A., and Darwin, D., DATASET: Results from Cyclic Tests of Reinforced Concrete Column-Foundation Connections, KU Scholarworks, Lawrence, KS, January 2025. https://hdl.handle.net/1808/35803Recent tests of column-foundation connections showed that these types of connections are prone to fail by concrete breakout at low deformation demands when subjected to cyclic loading. This report describes tests of four large-scale reinforced concrete column-foundation connections that were designed to investigate how foundation reinforcement details affect deformation capacity. Primary variables were the amount of foundation flexural reinforcement (spaced at 5.5 in., 9 in., or 12 in. in two directions), whether foundation transverse reinforcement was provided around the column, and foundation depth (18 in. or 30 in.). All specimens had the same column nominal dimensions, column reinforcement, concrete compressive strength (6000 psi), and nominal reinforcing bar yield stress (60 ksi). Lateral loads were applied to the column, while the foundations had vertical simple supports located 10 ft apart and a horizontal support 9 in. from the top of the foundation. The foundations were designed for the shear and flexural demands associated with the expected flexural strength of the column.
All specimens exhibited similar strengths, which were limited by column flexural yielding, and failed by breakout within the foundation that limited the deformation capacity. The results show that deformation capacity of column-foundation connections is sensitive to the amount of foundation longitudinal reinforcement, and that adding longitudinal bars or small quantities of foundation shear reinforcement delays breakout in specimens like those tested. Conversely, increasing the foundation depth without also increasing column bar embedment length led to somewhat earlier breakout and reduced deformation capacity. Strain measurements suggested that initiation of breakout is linked to bond strength decay along the straight portion of the column hooked bars, which in turn may be linked to the magnitude of strains in the top mat of foundation longitudinal reinforcement. Strains in the top mat of foundation longitudinal bars were larger than in the bottom mat and larger than expected based on strength calculations, suggesting that the top mat was more active in resisting transfer moment than the bottom mat.Electric Power Research Institut
Development Length and Splice Strength of High-Strength Reinforcing Bars in High-Strength Concrete
No full textThirty-nine tension lap-splice tests of high-strength reinforcement in high-strength concrete were performed and combined with test results in a large database to develop and evaluate design criteria for splice and development length. The experimental study included spliced No. 5, No. 8, No. 11, and No. 14 (16, 25, 36, and 43 mm) bars loaded to stresses at splice failure ranging from 70 to 150 ksi (483 to 1034 MPa) in concrete with compressive strengths between 6 and 16 ksi (41 to 110 MPa), with all but one specimen with strengths above 10 ksi (69 MPa). Other variables include the quantity of confining transverse reinforcement; minimum concrete cover [1 to 3.1 in. (25 to 79 mm)]; and splice lengths [17db to 54db], where db is the bar diameter. ASTM A1035 (Grade 120 (830)) bars were used to ensure splice failure prior to yielding.
The development/splice strength criteria developed in this study account for the effect of concrete cover, bar spacing, bar geometry, bar size, splice/development length, confining transverse reinforcement, and concrete compressive strength. The design expression incorporates a strength reduction factor based on a reliability-based approach and the Monte Carlo technique.
The contribution of concrete strength to bond for bars not confined by transverse reinforcement is best represented by the ¼ power of concrete compressive strength, and for bars confined by transverse reinforcement, the increase in bond strength due to transverse reinforcement is best represented by ½ power of concrete compressive strength. Increases in splice/development lengths above 60db are ineffective for bars not confined by transverse reinforcement.
The design criteria in ACI 318-19 for the development length of straight reinforcement are unconservative for bars not confined by transverse reinforcement, regardless of bar size and bar stress, and are unconservative for No. 18 (57 mm) bars confined by transverse reinforcement. ACI 318-19 is also unconservative for No. 6 (19 mm) and smaller bars confined by transverse reinforcement when (1) the smaller of the concrete side cover to the center of the bar or half the center-to-center bar spacing is less than the bottom (or top) cover to the center of the bar and (2) the clear distance of a splice to the nearest vertical leg of confining transverse reinforcement is greater than 4db. The descriptive equation in ACI 408R-03 progressively overpredicts bond strength as bar size increases, regardless of the presence of confining transverse reinforcement and for bars not confined by transverse reinforcement with an increase in splice length. The descriptive equation developed in this study is not biased with respect to bar size and not biased with respect to splice length for bars not confined by transverse reinforcement. It slightly underpredicts the bond strength with increased splice length for bars confined by transverse reinforcement. The descriptive equation and design criteria developed in this study are applicable for concrete compressive strengths up to 16 ksi (110 MPa) and bar stresses up to 125 ksi (862 MPa) for bars not confined by transverse reinforcement and 155 ksi (1069 MPa) for bars confined by transverse reinforcement.
Four modifications are proposed to reduce the unconservative nature of ACI 318-19 design criteria: (1) limit maximum splice/development length to 60db for bars without confining transverse reinforcement; (2) use a confinement factor of 1.15 and 1.0 for bars without and with confining transverse reinforcement, respectively; (3) use a bar size factor of 1.2 for bars larger than No. 11 (36 mm) not confined by transverse reinforcement and bars larger than No. 14 (43 mm) confined by transverse reinforcement; and (4) do not consider vertical confining reinforcement, and thus, take Ktr = 0, for No. 6 (19 mm) and smaller bars when (i) the smaller of the concrete side cover to the center of the bar and half the center-to-center bar spacing is less than the bottom (or top) cover to the center of the bar, and (ii) the clear distance of a splice to the nearest vertical leg of confining transverse reinforcement is greater than 4db.CRSI Education and Research Foundatio
Proceedings of the 2024 Hawk Talks
No full textThis volume contains the proceedings of the 2024 Hawk Talk Conference held on April 26th at the University of Kansas Edwards Campus in Overland Park, Kansas.The 2024 Hawk Talks Conference Proceedings showcase works from students representing a diverse range of programs, including Applied Biological Sciences, Exercise Science, Health Sciences, Environmental Science, Psychology, and Biotechnology. The Hawk Talks Conference is an opportunity for students to present year-end capstone, honors, and independent research projects. The agenda of talks and poster presentations are on pages four and five. Abstracts and short biographies appear in the remaining pages organized by the order of the talks. These are followed by the abstracts and bios of our poster presentations
Social Identity and Voting Behavior in a Deeply Divided Society: The Case of Israel
No full textThis paper examines what best explains political behavior in a deeply divided society. Despite the democratic nature of the Israeli political system, we suggest that Israel’s society is characterized by social affiliations mainly defined by social identity that include race, ethnicity, and religion and amount to tribalism. Based on the results of the 2020 election, we examined whether these social affiliations or other socioeconomic characteristics better explain voting behavior. First, we found a significant correlation between tribalism and voting behavior in Israel and socioeconomic characteristics and voting behavior in Israel. When comparing tribalism’s correlation versus other socioeconomic characteristics, we found that the correlation between tribalism and voting behavior in Israel trumps the correlation between socioeconomic characteristics and voting behavior in Israel, except for the Ashkenazi Jews. In other words, voting behavior is better explained by affiliation to the social group, that is, by kinship, race, ethnicity, and religion, than by other socioeconomic characteristics such as education level, economic status, or geographic location. This extends the idea of “in-group favoritism”
One Hundred and Fifty Years of Change on the Great Plains
No full textThis book presents pairs of photographs from across the Great Plains, taken in 1873-1874 and in 2021-2023. It has been presented as an open-access ebook, and is also available in hard-copy format on a print-on-demand basis at https://www.lulu.com/shop/a-townsend-peterson/one-hundred-and-fifty-years-of-change-on-the-great-plains/hardcover/product-gjg74wm.html
Note: This ebook is best viewed in two-page spreads, so you can compare the old and new photographs side-by-side.Robert Benecke (1835-1903) was a St. Louis photographer who was hired by the Kansas Pacific Railroad to take promotional photographs along the entire length of the Railroad. Benecke traveled from Kansas City to Denver in the early 1870s, creating a rich legacy of views of the Great Plains at a very early date. In this book, Benecke's landscape photographs are paired with new photographs of the same views. Comparing the old and new photographs, the reader can appreciate how the region has changed in terms of its landscape, vegetation, and human and natural systems over the 150 year time span
Steady state solutions of the Ericksen-Leslie model
No full textThese are the slides from a presentation given at AMS Sectional on 09/14/2024.In this talk we consider nematic liquid crystal placed between two parallel plates. We investigate this set-up by use of the Ericksen-Leslie model with certain boundary conditions to describe this physical system. This model provides us with very rich phenomena. We will first look into steady states in the system and then study the stability of these steady states using numerical methods. These steady states fall into a variety of cases which the study of shows a variety of dynamics including the presence of a saddle node bifurcation and further dynamics of the unstable states shows the evidence of the existence of heteroclinic orbit
Enhancing Tacit Knowledge Construction in Architectural Engineering Education Through 4E Cognition and Virtual Reality
No full textThis is the paper from a presentation given at Frontiers in Education (FIE) Conference on 10/15/2024.This innovative practice paper describes a novel educational framework that combines 4E cognition (embodied, embedded, enactive, and extended) with Virtual Reality (VR) technology to improve tacit knowledge (TK) acquisition in Architectural Engineering Education (AEE). In AEE studio courses, students solve and experience real-world design problems, experiment with solutions, and engage in reflective practices and cognitive processes in collaborative settings. This facilitates the rich development of TK, which includes intuition, practical skills, and lived experiences. However, in theoretical and technical courses, which rely heavily on passive learning of abstract concepts, there is not the same opportunity for students to cultivate TK, resulting in a disconnect between theoretical knowledge and practical applications. This gap can be bridged by leveraging VR's immersive and interactive capabilities, which the 4E cognition principles can strengthen. The 4E cognition emphasizes active learning experiences that mirror the “doing and reflecting” cycle found in AEE studio courses. This synergy between VR and 4E creates an engaging and effective learning environment for students to develop both explicit and tacit knowledge. This approach provides an opportunity for students, digital natives, to improve their intuitive ability to apply, analyze, evaluate, and create architectural knowledge. While only a few studies have used VR environments for AEE, there is no educational framework for designing experiences and sequences that immerse students in their learning processes for TK development. As a result, this paper proposes a VR-based theoretical framework with eight stages for developing immersive and interactive experiences that promote embodied learning, social interaction, and a deeper understanding of theoretical principles. Furthermore, a case study from a structural building course demonstrates how the framework facilitates building TK by simulating scenarios that promote deep cognitive engagement and intuitive problem-solving. This approach aligns with digital natives' learning preferences and aims to provide future architects with both theoretical knowledge and practical, innovative design skills necessary for professional success
Rapid Macrocell Tests of 2304 Reinforcing Bars
No full textThe corrosion resistance of 2304 stainless steel reinforcing bars produced by Raajratna Metal Industries Ltd. was tested in accordance with Annexes A1 and A2 of ASTM 955. The 2304 stainless steel reinforcing bars evaluated in this report met the requirements of ASTM A955.Raajratna Metal Industries Ltd
Sovereignty and Sobriety: The Intersection of Temperance, Statehood, and Native American Disenfranchisement in Oklahoma
No full textSubmitted to the Department of History of the University of Kansas in partial fulfillment of the requirements for departmental honorsOn November 16, 1907, Oklahoma was admitted to the Union, merging Oklahoma Territory and Indian Territory into a singular, unified state. While Oklahoma’s journey to statehood might appear rather straightforward, a complex story lies beneath the surface of its history. This study examines the story of Oklahoma statehood and the effects it had on Indigenous peoples through the lens of the Temperance Movement. Oklahoma, unlike any other state, had Prohibition inscribed in its constitution, a crucial factor in this complicated history. Temperance actors were pivotal factors in influencing statewide Prohibition in Oklahoma, but it also ended up playing a part in the infringement on Indigenous peoples. Thus, the impact of Temperance on Indigenous peoples then became extremely convoluted. Temperance was first utilized by Native Americans to leverage sovereignty and in hopes to secure statehood separate from Oklahoma, but as statehood was achieved and Native nations were dispossessed and had their self-governance eliminated Temperance was then utilized more so as a tool of control of Indigenous bodies. Native peoples, however, resisted these attacks by advocating for themselves at both the Sequoyah and Oklahoma Constitutional conventions