title: Experimental investigation of timber-to-steel connection using self-drilling wing screws

authors: Mohanswamy, Gowrava

abstract: Self-drilling wing screws are well-suited for hardwood and pressed material boards and are explored as an alternative connector to traditional bolts for connecting thick hot-rolled steel with timber. The wing avoids force-feeding of the screw into the timber which prevents the timber from cracking. However, limited studies were found on the timber-to-steel connection using self-drilling wing screws under shear loading. This paper investigates the shear behaviour and capacity of self-drilling winged screw connections between radiata pine timber and hot rolled steel plate through the experimental test. In addition, tensile coupon tests, screw bending tests, moisture content tests, screw pullout tests, and screw bearing tests were performed to determine the material properties of the steel, timber, and screws. A total of 70 experimental tests were conducted on the timber to steel connection connections with different steel thicknesses (8mm-20mm), timber thickness (15mm-45mm), numbers of screws (1-3), and screw axis angle (45°-90°). The failure mode is theoretically analyzed using Johansen yield theory. The resulting data from Eurocode 5 [24] was compared with experimental results as current AS/NZ standards lack adequate guidance in addressing timber-to-steel connections. From the above comparison, it was found that the Eurocode 5 [24] was under-conservative by 90%. Based on the experimental results, new design equations for calculating the shear capacity of self-drilling winged screws are proposed.

text: Experimental investigation of timber-to-steel connection using self-drilling wing screws Self-drilling wing screws are well-suited for hardwood and pressed material boards and are explored as an alternative connector to traditional bolts for connecting thick hot-rolled steel with timber. The wing avoids force-feeding of the screw into the timber which prevents the timber from cracking. However, limited studies were found on the timber-to-steel connection using self-drilling wing screws under shear loading. This paper investigates the shear behaviour and capacity of self-drilling winged screw connections between radiata pine timber and hot rolled steel plate through the experimental test. In addition, tensile coupon tests, screw bending tests, moisture content tests, screw pullout tests, and screw bearing tests were performed to determine the material properties of the steel, timber, and screws. A total of 70 experimental tests were conducted on the timber to steel connection connections with different steel thicknesses (8mm-20mm), timber thickness (15mm-45mm), numbers of screws (1-3), and screw axis angle (45°-90°). The failure mode is theoretically analyzed using Johansen yield theory. The resulting data from Eurocode 5 [24] was compared with experimental results as current AS/NZ standards lack adequate guidance in addressing timber-to-steel connections. From the above comparison, it was found that the Eurocode 5 [24] was under-conservative by 90%. Based on the experimental results, new design equations for calculating the shear capacity of self-drilling winged screws are proposed.

year: 2024

title: Topical gradients in plant ecology

authors: Laughlin, Daniel C.

subjects: Community ecology

abstract: Plant ecology spans multiple levels of biological organization and spatio-temporal scales, and over four dozen plant ecology textbooks have been published since Warming's (1895) 'Oecology of Plants.' With increasing emphasis on specialization, students and teachers can feel paralyzed by the vast literature, and as such may lack an adequate appreciation of the history of the field. The objective of this study was to derive a comprehensive set of topics that are covered in plant ecology textbooks, and to ask (1) what are the most important topical gradients among textbooks, and (2) has the emphasis of topics changed over time? The NMS ordination determined that the first gradient represented a clear contrast in emphasis on physiological ecology versus community ecology. The second gradient represented a contrast in emphasis on abiotic environmental factors versus biotic factors. Negative interactions, growth, demography, gas exchange, mineral nutrition, stress, diversity, disturbance, herbivory, paleoecology, ecosystem ecology, pollution, and global change have increased in emphasis over time. The increasing reliance on data and the number of authors per textbook illustrates how the discipline has matured into a rigorous quantitative science that requires a diversity of specializations. These results can be used to inform the development of curricula within a single course or across several years of study, and to assist the development of new and revised textbooks. Plant ecologists need to be familiar with this core set of topics in addition to becoming an expert in a few of them.

text: Topical gradients in plant ecology Plant ecology spans multiple levels of biological organization and spatio-temporal scales, and over four dozen plant ecology textbooks have been published since Warming's (1895) 'Oecology of Plants.' With increasing emphasis on specialization, students and teachers can feel paralyzed by the vast literature, and as such may lack an adequate appreciation of the history of the field. The objective of this study was to derive a comprehensive set of topics that are covered in plant ecology textbooks, and to ask (1) what are the most important topical gradients among textbooks, and (2) has the emphasis of topics changed over time? The NMS ordination determined that the first gradient represented a clear contrast in emphasis on physiological ecology versus community ecology. The second gradient represented a contrast in emphasis on abiotic environmental factors versus biotic factors. Negative interactions, growth, demography, gas exchange, mineral nutrition, stress, diversity, disturbance, herbivory, paleoecology, ecosystem ecology, pollution, and global change have increased in emphasis over time. The increasing reliance on data and the number of authors per textbook illustrates how the discipline has matured into a rigorous quantitative science that requires a diversity of specializations. These results can be used to inform the development of curricula within a single course or across several years of study, and to assist the development of new and revised textbooks. Plant ecologists need to be familiar with this core set of topics in addition to becoming an expert in a few of them.

year: 2012

title: Barriers and facilitators of access to psychological services for indigenous populations: A scoping review and thematic analysis

authors: Plessas, Anna

abstract: Background:
The extent to which behavior-analytic interventions are offered to Indigenous populations across CANZUS in accessible and culturally appropriate ways is unknown. We conducted a scoping review with a thematic analysis of the extant literature to find: (1) what are the barriers and facilitators for providing effective and equitable delivery of psychological services (with a behavioral component) to Indigenous populations; and (2) what tools and practices exist for an effective and equitable service delivery.
Methods:
We systematically reviewed Medline, CINAHL, PubMed, PsycInfo, Web of science, Ovid and INNZ databases between 1990 and 2020. For the scoping review, we adhered to the JBI methodological approach (2015) and the PRISMA strategy for the identification, selection, and appraisal of the reviewed articles. A total of 1265 unique articles met the criteria for the screening by title; 238 by abstract; 57 were included for full text assessment; and 37 were included in the final analysis.
Results:
Three themes were revealed to account for the barriers and facilitators of culturally friendly practices: (1) connecting practices are about interactions shaping the relationship between service provider and service client; (2) innovative practices test new approaches and innovations that could facilitate access to psychological services and overcome barriers, and (3) reflective practices are about critically examining the processes and actions undertaken toward effective cultural adaptation of services.
Conclusions:
Our analysis suggests that the level of success in bringing together services and the recipients of treatment (connection), showing flexibility and persistence in finding solutions (innovation) and examining the role of our behaviors in reaching our goals (reflection) is determined by the providers' action in the aforementioned three dimensions of practice.

text: Barriers and facilitators of access to psychological services for indigenous populations: A scoping review and thematic analysis Background:
The extent to which behavior-analytic interventions are offered to Indigenous populations across CANZUS in accessible and culturally appropriate ways is unknown. We conducted a scoping review with a thematic analysis of the extant literature to find: (1) what are the barriers and facilitators for providing effective and equitable delivery of psychological services (with a behavioral component) to Indigenous populations; and (2) what tools and practices exist for an effective and equitable service delivery.
Methods:
We systematically reviewed Medline, CINAHL, PubMed, PsycInfo, Web of science, Ovid and INNZ databases between 1990 and 2020. For the scoping review, we adhered to the JBI methodological approach (2015) and the PRISMA strategy for the identification, selection, and appraisal of the reviewed articles. A total of 1265 unique articles met the criteria for the screening by title; 238 by abstract; 57 were included for full text assessment; and 37 were included in the final analysis.
Results:
Three themes were revealed to account for the barriers and facilitators of culturally friendly practices: (1) connecting practices are about interactions shaping the relationship between service provider and service client; (2) innovative practices test new approaches and innovations that could facilitate access to psychological services and overcome barriers, and (3) reflective practices are about critically examining the processes and actions undertaken toward effective cultural adaptation of services.
Conclusions:
Our analysis suggests that the level of success in bringing together services and the recipients of treatment (connection), showing flexibility and persistence in finding solutions (innovation) and examining the role of our behaviors in reaching our goals (reflection) is determined by the providers' action in the aforementioned three dimensions of practice.

year: 2021