Geometry of screw compressor rotors and their tools

This paper presents a method of general geometrical definitions of screw machine rotors and their manufacturing tools. It describes the details of lobe shape specification, and focuses on a new lobe profile, which yields a larger cross-sectional area and shorter sealing lines resulting in higher delivery rates for the same tip speed. A well proven mathematical model was used to determine the optimum profile, compressor housing size, and compressor ports to achieve the superior compressors.     

Taking Students Seriously: Their rights to be safe at school

In a broader study of students' rights at school, high school students in New Zealand were asked about whether gay/lesbian/bisexual students would feel safe at their school. Data are reported from a nationwide survey of 107 high schools involving 821 students (aged 15-16 years) and 438 staff who responded to a questionnaire. The article focuses on how students and staff describe attitudes to lesbian/gay/bisexual students, and identifies the most prevalent discourses, including a counter-discourse of acceptance. Although attention to a discourse of acceptance risks the effect of undermining the implications of extreme violence against lesbian/gay/bisexual students, it also challenges the pervasive construction of lesbian/gay/bisexual students as victims. The authors argue that attention to discourses of acceptance might open up further discursive and material strategies for working towards the safety of all school students, including lesbian/gay/bisexual students.