Influence of photo-initiator concentration on residual mechanical stress in SU-8 thin films

In this paper, experimental results on the residual mechanical stress generated during the different steps of the photolithography process of SU-8 thin films using different photo-initiator concentrations are presented. The main aim of the reported research work has been firstly to investigate and identify the causes for the generation of residual stresses and secondly to optimise the fabrication process in order to minimise the residual stresses. It was found that the major parameters that influence the generation of internal stresses were the exposure time, the post-baking temperature and time and the concentration of the photoinitiator which is used (Cyracure UVI). At lower concentrations of the photo-initiator, the measured stress levels after the post-baking step were consistently found to be significantly lower than the ones corresponding to higher photo-initiator concentrations. In addition, there was an additional improvement by using a ramping hot-plate. Finally, preliminary experiments were carried out in order to encapsulate nanoparticles in these low stress SU-8 thin films

A review of diagnostic and functional imaging in headache

The neuroimaging of headache patients has revolutionised our understanding of the pathophysiology of primary headaches and provided unique insights into these syndromes. Modern imaging studies point, together with the clinical picture, towards a central triggering cause. The early functional imaging work using positron emission tomography shed light on the genesis of some syndromes, and has recently been refined, implying that the observed activation in migraine (brainstem) and in several trigeminal-autonomic headaches (hypothalamic grey) is involved in the pain process in either a permissive or triggering manner rather than simply as a response to first-division nociception per se. Using the advanced method of voxel-based morphometry, it has been suggested that there is a correlation between the brain area activated specifically in acute cluster headache — the posterior hypothalamic grey matter — and an increase in grey matter in the same region. No structural changes have been found for migraine and medication overuse headache, whereas patients with chronic tension-type headache demonstrated a significant grey matter decrease in regions known to be involved in pain processing. Modern neuroimaging thus clearly suggests that most primary headache syndromes are predominantly driven from the brain, activating the trigeminovascular reflex and needing therapeutics that act on both sides: centrally and peripherally

Saturn Atmospheric Structure and Dynamics

2 Saturn inhabits a dynamical regime of rapidly rotating, internally heated atmospheres similar to Jupiter. Zonal winds have remained fairly steady since the time of Voyager except in the equatorial zone and slightly stronger winds occur at deeper levels. Eddies supply energy to the jets at a rate somewhat less than on Jupiter and mix potential vorticity near westward jets. Convective clouds exist preferentially in cyclonic shear regions as on Jupiter but also near jets, including major outbreaks near 35°S associated with Saturn electrostatic discharges, and in sporadic giant equatorial storms perhaps generated from frequent events at depth. The implied meridional circulation at and below the visible cloud tops consists of upwelling (downwelling) at cyclonic (anti-cyclonic) shear latitudes. Thermal winds decay upward above the clouds, implying a reversal of the circulation there. Warm-core vortices with associated cyclonic circulations exist at both poles, including surrounding thick high clouds at the south pole. Disequilibrium gas concentrations in the tropical upper troposphere imply rising motion there. The radiative-convective boundary and tropopause occur at higher pressure in the southern (summer) hemisphere due to greater penetration of solar heating there. A temperature “knee ” of warm air below the tropopause, perhaps due to haze heating, is stronger in the summer hemisphere as well. Saturn’s south polar stratosphere is warmer than predicted by radiative models and enhanced in ethane, suggesting subsidence-driven adiabatic warming there. Recent modeling advances suggest that shallow weather laye

Experience of 3 Types of Commercially Available Photodiode Array in the Daresbury Laboratory Energy Dispersive EXAFS Detector System

The technique of Energy Dispersive EXAFS is well established as an excellent tool for dynamic measurements. Daresbury Laboratory has developed a photodiode array based detector system for synchrotron radiation Energy Dispersive EXAFS experiments which allows high quality data to be collected in time scales of less than a second [1]. In order to provide the highest quality system the performance of 3 different commercially available photodiode arrays has been evaluated. This paper presents the results of these evaluations and indicates the future direction of this project

Simultaneous time resolved X-ray scattering experiments in the small and wide angle region

A SAXS synchrotron beam line is equipped with a second detector system so that simultaneous WAXS experiments can be performed. Modular sample environment cells give the possibility to obtain extra thermodynamical information. Experiments have been performed on a variety of samples

Caracterização bioquímica de cultivares de cana-de-açúcar (Saccharum spp.): isoenzimas, proteína solúvel e valor brix Biochemical characterization of sugarcane (Saccharum spp.) cultivars: isoenzymes, solubre protein and brix value

No presente trabalho foram determinados o perfil isoenzimático diferencial de esterase e peroxidase, a proteína total solúvel e os sólidos solúveis (sacarose) em graus brix, de 10 cultivares de cana-de-açúcar (Saccharum spp.) atualmente cultivados no Brasil. Os cultivares estudados foram: NA 56-79, IAC 52-150, IAC 64-257, SP 70-1143, SP 71-3146, SP 71-3149, SP 71-1406, SP 71-6163, SP 71-61-68 e SP 71-799. Com os dados obtidos foi possível comprovar o valor taxonômico das características bioquímicas que representam uma inovação em taxonomia de cana-de-açúcar no Brasil. As isoenzimas de esterase apresentaram um padrão eletroforético específico para cada cultivar estudado, enquanto que as isoenzimas de peroxidase só permitiram agrupar os cultivares por apresentarem o mesmo padrão eletroforético para cada grupo formado. Tanto as isoenzimas de esterase como peroxidase apresentaram-se constantes em um mesmo cultivar. Os sólidos solúveis (sacarose) em Graus Brix e a determinação da proteína solúvel, mesmo sendo pouco variáveis, apresentaram-se úteis para a caracterização dos cultivares estudados.<br>In the present work the isoenzyme profiles of the enzymes esterase and peroxidase, the level of total soluble protein and the soluble solids (sucrose) were determined of the following sugarcane (Saccharum spp.) cultivare: NA 56-79; IAC 52-150; IAC 64-257; SP 70-1143; SP 71-3146; SP 71-3149; SP 71-1406; SP 71-6163; SP 71-61-68 and SP 71-799. Esterase isoenzymes showed a specific electrophoretic pattern for each one of the cultivare, while the peroxidase allowed to arrange the cultivare in groups, each one with a specific electrophoretic pattern. The isoenzymes of both esterase and peroxidase were constant in a given cultivar. Total soluble protein levels and soluble solids (sucrose, Brix value) varied among the cultivare. Statistical analysis showed that these biochemical parameters are useful for the characterization of the cultivare under study