The White Rabbit Project

Reliable, fast and deterministic transmission of control information in a network is a need formany distributed systems. One example is timing systems, where a reference frequency is used to accurately schedule time-critical messages. TheWhite Rabbit (WR) project is a multi-laboratory and multi-company effort to bring together the best of the data transfer and timing worlds in a completely open design. It takes advantage of the latest developments for improving timing over Ethernet, such as IEEE 1588 (Precision Time Protocol) and Synchronous Ethernet. The presented approach aims for a general purpose, fieldbus-like transmission system, which provides deterministic data and timing (sub-ns accuracy and ps jitter) to around 1000 stations. It automatically compensates for fiber lengths in the order of 10 km. This paper describes the WR design goals and the specification used for the project. It goes on to describe the central component of the WR system structure - the WR switch - with theoretical considerations about the requirements. Finally, it presents real timing measurements for the first prototypes of WR hardware

Central nervous system mast cells in peripheral inflammatory nociception

<p>Abstract</p> <p>Background</p> <p>Functional aspects of mast cell-neuronal interactions remain poorly understood. Mast cell activation and degranulation can result in the release of powerful pro-inflammatory mediators such as histamine and cytokines. Cerebral dural mast cells have been proposed to modulate meningeal nociceptor activity and be involved in migraine pathophysiology. Little is known about the functional role of spinal cord dural mast cells. In this study, we examine their potential involvement in nociception and synaptic plasticity in superficial spinal dorsal horn. Changes of lower spinal cord dura mast cells and their contribution to hyperalgesia are examined in animal models of peripheral neurogenic and non-neurogenic inflammation.</p> <p>Results</p> <p>Spinal application of supernatant from activated cultured mast cells induces significant mechanical hyperalgesia and long-term potentiation (LTP) at spinal synapses of C-fibers. Lumbar, thoracic and thalamic preparations are then examined for mast cell number and degranulation status after intraplantar capsaicin and carrageenan. Intradermal capsaicin induces a significant percent increase of lumbar dural mast cells at 3 hours post-administration. Peripheral carrageenan in female rats significantly increases mast cell density in the lumbar dura, but not in thoracic dura or thalamus. Intrathecal administration of the mast cell stabilizer sodium cromoglycate or the spleen tyrosine kinase (Syk) inhibitor BAY-613606 reduce the increased percent degranulation and degranulated cell density of lumbar dural mast cells after capsaicin and carrageenan respectively, without affecting hyperalgesia.</p> <p>Conclusion</p> <p>The results suggest that lumbar dural mast cells may be sufficient but are not necessary for capsaicin or carrageenan-induced hyperalgesia.</p

Processes and Economics for Energetic Use of Cotton Plant Residues

Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a Technical article from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 3 (2001): T. Fischer, M. Gaderer, P. Lamp, W. Schoelkopf, and R. Ziegler. Processes and Economics for Energetic Use of Cotton Plant Residues. Vol. III, February 2001

influence of torrefaction and hydrothermal carbonisation on fuel and ash properties

In this work, torrefied as well as hydrothermal carbonised biomass have been examined. To evaluate the torrefaction process, grindability, ash melting behaviour and fuel as well as ash composition of untreated and torrefied woods were analysed. For that purpose populus, alder, spruce and birch have been used. Significant differences in heating values and particle size distributions could be observed. For spruce and birch a mean increase in the heating value of 15 % has been observed. For poplar and alder the heating value slightly increased by 7-9 %. The increase in heating value can be mainly explained with the decrease in oxygen and hydrogen containing compounds. The median values of the ground fractions for the torrefied woody biomass were within the range from 80 to 95 µm, whereas the nontorrefied woody biomass showed median values ranging from 180 to 230 µm. Main components of the ash of all analysed wooden biomass are potassium oxide, silicon oxide and calcium oxide. Torrefied biomass shows a broader melting range and a more pronounced melting peak. Analysis of ash melting, ash characteristic numbers and FactSage simulations of the untreated and torrefied wood, show a lower melting range at lower melting temperatures reffering to the untreated biomass. The H/C and the O/C ratio of the HTC coals show similar results as lignite. Except for the hydrothermal carbonised green waste, the HTC-coals of spent grains and compost show a high melting range in the field of the torrefied woods. Keywords: torrefaction, ashes, calorific value, biocha