Flatness optimization of micro-injection moulded parts: The case of a PMMA microfluidic component

Micro-injection moulding (µ-IM) has attracted a lot of interest because of its potential for the production of low-cost, miniaturized parts in high-volume. Applications of this technology are, amongst others, microfluidic components for lab-on-a-chip devices and micro-optical components. In both cases, the control of the part flatness is a key aspect to maintaining the component's functionality. The objective of this work is to determine the factors affecting the flatness of a polymer part manufactured by µ-IM and to control the manufacturing process with the aim of minimizing the in-process part deformation. As a case study, a PMMA microfluidic substrate with overall dimensions of 10 mm diameter and 1 mm thickness was investigated by designing a µ-IM experiment having flatness as the experimental response. The part flatness was measured using a micro-coordinate measuring machine. Finite elements analysis was also carried out to study the optimal ejection pin configuration. The results of this work show that the control of the µ-IM process conditions can improve the flatness of the polymer part up to about 15 µm. Part flatness as low as 4 µm can be achieved by modifying the design of the ejection system according to suggested guideline

A Vineyard in a Law Clinic: The Practical Application of a Therapeutic Jurisprudence Philosophy in a UK Law Clinic

In late 2015, the British Red Cross approached the lead author. It was increasingly evident that given the austerity-driven political agenda of the UK government in cutting public funding to advisory services, coupled with the developing refugee crisis and its impact on countries and regions, refugees in many parts of the UK were in need of legal and non-legal assistance. University law clinics were an obvious source of support given their objectives of developing students’ understanding and engagement with community groups. As our law clinic, based in the Helena Kennedy Centre for International Justice (HKC), was developed specifically to address the needs of groups such as refugees, and given the ground-breaking work of Wexler and Winick (in Therapeutic Jurisprudence) and Gould and Perlin (on its application to clinical legal education) on providing a therapeutically positive experience for users, we sought to base our clinic aligned with Therapeutic Jurisprudence (TJ) principles. This paper examines the development and practical operation of a law clinic from a TJ perspective

Multi-wavelength visibility measurements of the red giant R Doradus

We present visibility measurements of the nearby Mira-like star R Doradus taken over a wide range of wavelengths (650--990 nm). The observations were made using MAPPIT (Masked APerture-Plane Interference Telescope), an interferometer operating at the 3.9-m Anglo-Australian Telescope. We used a slit to mask the telescope aperture and prism to disperse the interference pattern in wavelength. We observed in R Dor strong decreases in visibility within the TiO absorption bands. The results are in general agreement with theory but differ in detail, suggesting that further work is needed to refine the theoretical models.Comment: 8 pages; SPIE Conf. 4006 "Interferometry in Optical Astronomy

Domino Michael-aldol annulations for the stereocontrolled synthesis of bicyclo[3.3.1]nonane and bicyclo[3.2.1]octane derivatives

Domino Michael-aldol annulation of cycloalkane-1,3-diones with enals affords a general route to 6-hydroxybicyclo[3.3.1]nonane-2,9-diones and 2-hydroxybicyclo[3.2.1]octane-6,8-diones, notably in one-pot procedures under convenient conditions. The annulation is shown to be compatible with one or more substituents at six positions of the bicyclo[3.3.1]nonane-2,9-dione scaffold. In some cases, the relative configuration of the product can be controlled by the appropriate choice of solvent, base and temperature for the annulation. In contrast to the chair–chair conformations usually adopted, the bicyclo compounds derived from 2,4,4-trimethylcyclohexane-1,3-dione possessed boat-chair conformations. Oxidation of the annulation products gave the corresponding bicyclo triketones