The Strength of Partially Stiffened Stainless Steel Compression Members

The instability of partially stiffened stainless steel compression members due to local buckling of the flange element or flange and lip interaction has not been studied before. In this investigation the critical local buckling and post-buckling behaviour of cold-formed partially stiffened stainless steel compression elements is studied. It is concluded in this investigation that a plasticity reduction factor should be used to evaluate the critical local buckling stress as well as the effective width to calculate the ultimate capacity of partially stiffened stainless steel compression members

Out of Equilibrium Solutions in the XYXY-Hamiltonian Mean Field model

Out of equilibrium magnetised solutions of the $XY$-Hamiltonian Mean Field ($XY$-HMF) model are build using an ensemble of integrable uncoupled pendula. Using these solutions we display an out-of equilibrium phase transition using a specific reduced set of the magnetised solutions

Ground Truths in the Humanities

Ensuring a faithful interaction with data and its representation for humanities can and should depend on expert-constructed ground truths

Silicon micromachined hollow microneedles for transdermal liquid transfer

This paper presents an improved design and fabrication process [ 13 for hollow micro needles with the proper mechanical strength and sharpness to be applied for painless transdermal transfer of liquids. Tests have shown that liquids like blood are drawn into the needle by capillary forces, reducing the need for active pumping. The fabrication method allows different needle shapes like blades and pencils, is robust enough to be applied for largerscale production, and enables the development of a complete micro-TAS for e.g. blood analysis

On-site screening for syphilis at an antenatal clinic

Objective. To determine the validity, predictive value and accuracy of the rapid plasma reagin card test performed on site to diagnose active syphilis in pregnant women so that immediate treatment can be offered to prevent congenital syphilis.Design. Open, descriptive study.Setting. Antenatal clinic, Mamelodi Hospital, Pretoria.Patients. Four hundred and seventy-four pregnant women attending the antenatal clinic for the first time were entered into the study.Methods. A rapid plasma reagin test was performed on site with no specialised equipment and the results were compared with those of the reference laboratory.Results. In the event of rapid plasma reagin titres of 1:8 and higher, indicative of active syphilis, the on-site rapid plasma reagin test had a sensitivity of 90.5%. The test had a sensitivity of 100% if the rapid plasma reagin titres were 1:16 and higher.Conclusion. The on-site rapid plasma reagin test identified all women with rapid plasma reagin titres higher than 1:8. This implies that all women whose fetuses were in danger of acquiring congenital syphilis were identified at the clinic and could be treated immediately

Disseminating genetically modified (GM) maize technology to smallholder farmers in the Eastern Cape province of South Africa: extension personnel’s awareness of stewardship requirements and dissemination practices

Advice and technical information from extension services are critical in promoting new technologies and their adoption by farmers. This study determined extension personnel’s awareness of GM maize technology and the associated extension services they provide to smallholder GM maize farmers in the Eastern Cape province of South Africa. Face-to-face interviews were conducted with extension staff of the Department of Rural Development and Agrarian Reform (DRDAR) in the province. Results indicated that inadequate training of extension personnel on GM maize technology influenced their perceptions of GM maize technology and awareness of its stewardship requirements. Generally, personnel had a low level of awareness of GM maize technology as a pest control strategy. Awareness of GM maize stewardship requirements amongst extension personnel was also low. These extension personnel disseminated GM maize technology, which they generally perceived as a high-yield technology, to smallholder farmers using non-participatory approaches and media sourced from GM seed companies. The findings of this study suggest that ensuring safe and sustainable adoption of GM maize technology on smallholder farms will require a more participatory extension approach that emphasizes smallholder farmers’ access to information as well as the training of extension personnel on the stewardship requirements and dissemination practices associated with GM maize cultivation.Keywords: Dissemination, extension, GM maize technology, smallholders, stewardshi

Trajectory Deflection of Spinning Magnetic Microparticles, the Magnus Effect at the Microscale

The deflection due to the Magnus force of magnetic particles with a diameter of 80 micrometer dropping through fluids and rotating in a magnetic field was measured. With Reynolds number for this experiment around 1, we found trajectory deflections of the order of 1 degree, in agreement within measurement error with theory. This method holds promise for the sorting and analysis of the distribution in magnetic moment and particle diameter of suspensions of microparticles, such as applied in catalysis, or objects loaded with magnetic particles.Comment: 12 pages, 3 figures. Appendix with 6 figure