CCEER 23-01: Guidelines For Circular Rebar Cage Assembly With U-BOLT Connectors

Report No. CCEER 23-01This guideline presents a systematic fabrication and design approach for rebar cages using mechanical U-bolt connectors to ensure their stability and safety during the lifting process. The purpose of this guideline is to provide a straightforward tool for determining the layout of U-bolts and lifting points, and to quickly estimate rebar cage deflection during lifting. The guideline is based on a comprehensive experimental and analytical research campaign that investigated the behavior of rebar cages reinforced with U-bolt connectors. The research aimed to promote the adoption of U-bolt connectors as a viable solution to improve the overall safety of rebar cages not only during lifting, but in the future for all phases of construction

Linker Engineering of Ligand‐Decorated DNA Origami Nanostructures Affects Biological Activity

News from an old acquaintance: The streptavidin (STV)-biotin binding system is frequently used for the decoration of DNA origami nanostructures (DON) to study biological systems. Here, a surprisingly high dynamic of the STV/DON interaction is reported, which is affected by the structure of the DNA linker system. Analysis of different mono- or bi-dentate linker architectures on DON with a novel high-speed atomic force microscope (HS-AFM) enabling acquisition times as short as 50 ms per frame gave detailed insights into the dynamics of the DON/STV interaction, revealing dwell times in the sub-100 millisecond range. The linker systems are also used to present biotinylated epidermal growth factor on DON to study the activation of the epidermal growth factor receptor signaling cascade in HeLa cells. The studies confirm that cellular activation correlated with the binding properties of linker-specific STV/DON interactions observed by HS-AFM. This work sheds more light on the commonly used STV/DON system and will help to further standardize the use of DNA nanostructures for the study of biological processes

Socioeconomic inequality in domains of health: results from the World Health Surveys

<p>Abstract</p> <p>Background</p> <p>In all countries people of lower socioeconomic status evaluate their health more poorly. Yet in reporting overall health, individuals consider multiple domains that comprise their perceived health state. Considered alone, overall measures of self-reported health mask differences in the domains of health. The aim of this study is to compare and assess socioeconomic inequalities in each of the individual health domains and in a separate measure of overall health.</p> <p>Methods</p> <p>Data on 247,037 adults aged 18 or older were analyzed from 57 countries, drawn from all national income groups, participating in the World Health Survey 2002-2004. The analysis was repeated for lower- and higher-income countries. Prevalence estimates of poor self-rated health (SRH) were calculated for each domain and for overall health according to wealth quintiles and education levels. Relative socioeconomic inequalities in SRH were measured for each of the eight health domains and for overall health, according to wealth quintiles and education levels, using the relative index of inequality (RII). A RII value greater than one indicated greater prevalence of self-reported poor health among populations of lower socioeconomic status, called pro-rich inequality.</p> <p>Results</p> <p>There was a descending gradient in the prevalence of poor health, moving from the poorest wealth quintile to the richest, and moving from the lowest to the highest educated groups. Inequalities which favor groups who are advantaged either with respect to wealth or education, were consistently statistically significant in each of the individual domains of health, and in health overall. However the size of these inequalities differed between health domains. The prevalence of reporting poor health was higher in the lower-income country group. Relative socioeconomic inequalities in the health domains and overall health were higher in the higher-income country group than the lower-income country group.</p> <p>Conclusions</p> <p>Using a common measurement approach, inequalities in health, favoring the rich and the educated, were evident in overall health as well as in every health domain. Existent differences in averages and inequalities in health domains suggest that monitoring should not be limited only to overall health. This study carries important messages for policy-making in regard to tackling inequalities in specific domains of health. Targeting interventions towards individual domains of health such as mobility, self-care and vision, ought to be considered besides improving overall health.</p

Encouraging female entrepreneurship in Jordan: environmental factors, obstacles and challenges

The number of female entrepreneurs and their contribution to the economy is steadily rising. Yet research suggests that female entrepreneurs face more challenges and barriers than their male counterparts. This is expected to be even more prevalent in Islamic contexts, which are characterised by conservative and patriarchal societies. In this research, 254 female business students from a private and a public university responded to a questionnaire that gauges their perceptions about potential barriers to entrepreneurship in Jordan and whether the business education they are receiving helps to prepare them for future entrepreneurial activity. Our results help to form a basis on which a deeper understanding of the phenomena can be achieved through more in depth future research. Among the main environmental factors that worry potential female entrepreneurs are the weakness of Jordanian economy, lack of finance, fear of risk, gender inequality and inability to maintain a work and private life balance. Our results also show that students are really not aware of the opportunities available to them and are unable to make a proper assessment. We call on both universities and the Jordanian government to put more emphasis on practical entrepreneurial education and encouraging women to play a much more active role within the workforce

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Studies of Seismic Behavior of Steel Base Plates

Report No. CCEER-99-7This report summarizes studies conducted on steel base plates and their effect on the overall seismic response and behavior of a steel building. A two part program, experimental and analytical, was carried out to determine the cyclic behavior of column-base plates assemblies under large deformations and the response of a steel building designed with several base plate configurations. Based on this investigation a design procedure that limits the inelastic activity, during severe ground motions, to the steel plate is recommended. Six one-half scale column-base plates with various plate sizes and thickness were tested under constant gravity load and lateral cyclic deformations. The base plate assemblies were designed according to the recommended design procedure. The test results showed that the column base plate assemblies were able to dissipate significant amount of energy by plate bending. In addition, these tests showed the vulnerability of the welded connection between the column and the base plate. The failure mode for all six columns was the fracture of the weld between the column and base plate. Nonlinear finite element analyses using ADINA program were conducted on column base plate assemblies to determine the stress distribution profile underneath the base plate. In addition, Drain-3DX program was utilized to determine the seismic response of a four-story building with several base configurations. The base of this building was modeled as fixed, pinned, and semi-rigid to study its effect on the overall seismic response of the building

Seismic Analysis of the AISI LRFD Design Example of Steel Highway Bridges

Report No. CCEER 00-8The seismic specifications for highway bridges went through changes as a result of damaging earthquakes. In 1956, bridge specifications included a static load approach for the design of bridges in seismic zones. This approach was mainly based on the Structural Engineering Association of California (SEAOC) Blue Book, which specifies a percentage of the dead load and use it as lateral loads to account for seismic forces [l]. Recognizing the shortcomings of static forces in accounting for dynamic seismic forces, the California Department of Transportation (Caltrans), in 1968, included the effect of dynamic characteristics of bridges in the seismic design process [2]. Elastic dynamic analyses were performed during the seismic design of California bridges. However, after the significant highway damage during the 1971 San Fernando earthquake, Caltrans adopted in 1973, new seismic design criteria that included: � Seismicity � Soil Effect � Dynamic Characteristics � Ductility/Risk Reduction Facto

Cyclic Behavior of Built Up Steel Members and their Connections

Report No. CCEER-99-10-BThis report presents the results of the cyclic tests of six one-half scale double gusset plate connections, one built-up laced steel member, and one built-up perforated steel member. The test specimens were representative of connections and members of the San Francisco-Oakland Bay Bridge. The main objectives were to investigate the cyclic behavior of the specimens, determine their ultimate capacities, and determine their failure modes. The study concluded that edge buckling of double gusset plates is not a primary failure mode since the tested plates were capable of supporting additional loads after buckling occurred. The study also concluded that the lacing and rivet capacities of the laced member were not sufficient to maintain the integrity of the cross section, and as a result, the sectional properties, specifically the moment of inertia, need to be reduced to predict the axial compression capacity. (by authors

Cyclic Behavior of Double Gusset Plate Connections

Report No. CCEER-98-7This document presents the results of cyclic tests of eight 1/2. scale double gusset plate connections. The specimens represented diagonal member of the Western Spans of SFOBB. The specimens were subjected to lateral, axial, and eccentric load to determine their cyclic behavior and failure mode. The main objective of this research and development program was to investigate the actual cyclic behavior of double gusset plate connection and determine their ultimate capacities. An additional goal of this research program was to establish M-P curves for double gusset plate connections. The main conclusions of this research that edge buckling of double gusset plate is not primary failure mode since the tested plates were capable of supporting additional loads after buckling occurred. However, the post-buckling strength was accompanied by large lateral deflection, which causes concern if serviceability was a limiting concern. This report contains moment-axial interaction curves and procedures in determining the ultimate capacity of double gusset plate connections (Abstract by authors)

Cyclic Behavior of Laced and Perforated Steel Members on the San Francisco-Oakland Bay Bridge

Report No. CCEER-99-9This document presents the results of cyclic tests of two steel members, one laced and one perforated. The members represented 1/2 scale models of diagonal member TB2 on Bents A and B of the Western Spans of the San Francisco-Oakland Bay Bridge. The specimens were subjected to cyclic loads to determine their cyclic behavior and failure mode. The main objective of this research was to investigate the actual cyclic behavior of built-up laced and perforated members with their end connections as well as evaluate their ultimate capacities and post-buckling behavior. An additional goal of this research program was to determine the displacement ductility and energy dissipation capabilities of the members. One conclusion of this research is that the moment of inertia of laced members should be reduced according to Caltrans specifications to correctly predict the member capacity. Another conclusion is that the effective area of a perforated member that is connected by end gusset plates should be reduced due to a shear-lag effect. This report outlines procedures for determining the ultimate capacity of laced and perforated members connected to end gusset plates. (by authors