Iron Dominated Electromagnets: Design, Fabrication, Assembly and Measurements

Medium energy electron synchrotrons used for the production of high energy photons from synchrotron radiation is an accelerator growth industry. Many of these accelerators have been built or are under construction to satisfy the needs of synchrotron light users throughout the world. Because of the long beam lifetimes required for these synchrotrons, these medium energy accelerators require the highest quality magnets of various types. Other accelerators, for instance low and medium energy boosters for high energy physics machines and electron/positron colliders, require the same types of magnets. Because of these needs, magnet design lectures, were organized and presented periodically at biennual classes organized under the auspices of the US Particle Accelerator School (USPAS). These classes were divided among areas of magnet design from fundamental theoretical considerations, the design approaches and algorithms for permanent magnet wigglers and undulators and the design and engineering of conventional accelerator magnets. The conventional magnet lectures were later expanded for the internal training of magnet designers at LLNL at the request of Lou Bertolini. Because of the broad nature of magnet design, Dr. S. Y. Lee, the former Director of the Particle Accelerator School, saw the need for a specialized course covering the various aspects of the design, engineering and fabrication of conventional magnets. This section of the class was isolated and augmented using the LLNL developed material resulting in the class on conventional magnet design. Conventional magnets are defined (for the purposes of this publication) as magnets whose field shape is dominated by the shape of the iron magnet yoke and are excited by coils, usually wound from solid or hollow water-cooled copper or aluminum conductors. This publication collects the lecture notes, written for the first course in the USPAS conventional magnet design course and evolved over subsequent presentations of this same course, and organizes the material roughly divided among two parts. One part is theoretical and computational and attempts to provide a foundation for later chapters which exploit the expressions and algorithms for the engineering and design calculations required to specify magnet conceptual designs. A chapter is devoted to the description and use of one of many magnet codes used to characterize the two dimensional field resulting from various magnet cross-sections. A chapter is included which exploits the two-dimensional theory and applies the mathematics to techniques and systems for magnet measurement. The second part of this publication ranges to practical issues associated with the fabrication of components, assembly, installation and alignment of magnets. This section also includes fabrication practices which respond to personnel and equipment protection needs. Required design calculations are supplemented by examples and problems. A CD is included with tools provided to simplify the computation of some of the more tedious relationships. This CD also includes useful photographs and pictures describing the high volume production of typical magnet types, which if included in the publication will add too many pages and increase the cost of publication. Styles among those facing similar problems will result in a wide variation of individual magnet designs. Designs and technologies will evolve and improve. This publication provides a snapshot of the present technology and presents as examples the magnet designs developed in response to the needs of several projects, the Advanced Light Source at LBNL, PEPII Low Energy Ring and SPEAR3 synchrotron light source at SLAC and the Australian Light Source, currently under construction in Melbourne. In each example, the reasons for fabrication design decisions are itemized and rationalized as much as is reasonable. The examples presented in this publication are provided as starting points which can be used as a design basis for magnets required for future projects. It is hoped that the listing of some design choices and the motivation for these choices will be useful. It is the intention of the author to publish a document collecting and archiving the tools and techniques learned from the past masters in the craft and to provide a useful reference for future magnet designers

Annual variation in the levels of transcripts of sex-specific genes in the mantle of the common mussel, Mytilus edulis

Mytilus species are used as sentinels for the assessment of environmental health but sex or stage in the reproduction cycle is rarely considered even though both parameters are likely to influence responses to pollution. We have validated the use of a qPCR assay for sex identification and related the levels of transcripts to the reproductive cycle. A temporal study of mantle of Mytilus edulis found transcripts of male-specific vitelline coat lysin (VCL) and female-specific vitelline envelope receptor for lysin (VERL) could identify sex over a complete year. The levels of VCL/VERL were proportional to the numbers of sperm/ova and are indicative of the stage of the reproductive cycle. Maximal levels of VCL and VERL were found in February 2009 declining to minima between July - August before increasing and re-attaining a peak in February 2010. Water temperature may influence these transitions since they coincide with minimal water temperature in February and maximal temperature in August. An identical pattern of variation was found for a cryptic female-specific transcript (H5) but a very different pattern was observed for oestrogen receptor 2 (ER2). ER2 varied in a sex-specific way with male > female for most of the cycle, with a female maxima in July and a male maxima in December. Using artificially spawned animals, the transcripts for VCL, VERL and H5 were shown to be present in gametes and thus their disappearance from mantle is indicative of spawning. VCL and VERL are present at equivalent levels in February and July-August but during gametogenesis (August to January) and spawning (March to June) VCL is present at lower relative amounts than VERL. This may indicate sex-specific control mechanisms for these processes and highlight a potential pressure point leading to reduced reproductive output if environmental factors cause asynchrony to gamete maturation or release

A commonly carried genetic variant in the delta opioid receptor gene, OPRD1, is associated with smaller regional brain volumes: replication in elderly and young populations

Delta opioid receptors are implicated in a variety of psychiatric and neurological disorders. These receptors play a key role in the reinforcing properties of drugs of abuse, and polymorphisms in OPRD1 (the gene encoding delta opioid receptors) are associated with drug addiction. Delta opioid receptors are also involved in protecting neurons against hypoxic and ischemic stress. Here, we first examined a large sample of 738 elderly participants with neuroimaging and genetic data from the Alzheimer's Disease Neuroimaging Initiative. We hypothesized that common variants in OPRD1 would be associated with differences in brain structure, particularly in regions relevant to addictive and neurodegenerative disorders. One very common variant (rs678849) predicted differences in regional brain volumes. We replicated the association of this single-nucleotide polymorphism with regional tissue volumes in a large sample of young participants in the Queensland Twin Imaging study. Although the same allele was associated with reduced volumes in both cohorts, the brain regions affected differed between the two samples. In healthy elderly, exploratory analyses suggested that the genotype associated with reduced brain volumes in both cohorts may also predict cerebrospinal fluid levels of neurodegenerative biomarkers, but this requires confirmation. If opiate receptor genetic variants are related to individual differences in brain structure, genotyping of these variants may be helpful when designing clinical trials targeting delta opioid receptors to treat neurological disorders

Bar-Coded Pyrosequencing Reveals the Responses of PBDE-Degrading Microbial Communities to Electron Donor Amendments

Polybrominated diphenyl ethers (PBDEs) can be reductively degraded by microorganisms under anaerobic conditions. However, little is known about the effect of electron donors on microbial communities involved in PBDEs degradation. Here we employed 454 Titanium pyrosequencing to examine the phylogenetic diversity, composition, structure and dynamics of microbial communities from microcosms under the conditions of different electron donor amendments. The community structures in each of the five alternate electron donor enrichments were significantly shifted in comparison with those of the control microcosm. Commonly existing OTUs between the treatment and control consortia increased from 5 to 17 and more than 50% of OTUs increased around 13.7 to 186 times at least in one of the microcosms after 90-days enrichment. Although the microbial communities at different taxonomic levels were significantly changed by different environmental variable groups in redundancy analysis, significant correlations were observed between the microbial communities and PBDE congener profiles. The lesser-brominated PBDE congeners, tri-BDE congener (BDE-32) and hexa-BDE, were identified as the key factors shaping the microbial community structures at OTU level. Some rare populations, including the known dechlorinating bacterium, Dehalobacter, showed significant positive-correlation with the amounts of PBDE congeners in the consortia. The same results were also observed on some unclassified bacteria. These results suggest that PBDEs-degrading microbial communities can be successfully enriched, and their structures and compositions can be manipulated through adjusting the environmental parameters

Iron Dominated Electromagnets Design, Fabrication, Assembly and Measurements

Dedicated with Love to Sumi, for her support and devotion