Measurements of SCRF cavity dynamic heat load in horizontal test system

The Horizontal Test System (HTS) at Fermilab is currently testing fully assembled, dressed superconducting radio frequency (SCRF) cavities. These cavities are cooled in a bath of superfluid helium at 1.8K. Dissipated RF power from the cavities is a dynamic heat load on the cryogenic system. The magnitude of heat flux from these cavities into the helium is also an important variable for understanding cavity performance. Methods and hardware used to measure this dynamic heat load are presented. Results are presented from several cavity tests and testing accuracy is discussed.Comment: 6 pp. Cryogenic Engineering Conference and International Cryogenic Materials Conference 28 Jun - 2 Jul 2009. Tucson, Arizon

Dynamic PID loop control

The Horizontal Test Stand (HTS) SRF Cavity and Cryomodule 1 (CM1) of eight 9-cell, 1.3GHz SRF cavities are operating at Fermilab. For the cryogenic control system, how to hold liquid level constant in the cryostat by regulation of its Joule-Thompson JT-valve is very important after cryostat cool down to 2.0 K. The 72-cell cryostat liquid level response generally takes a long time delay after regulating its JT-valve; therefore, typical PID control loop should result in some cryostat parameter oscillations. This paper presents a type of PID parameter self-optimal and Time-Delay control method used to reduce cryogenic system parameters' oscillation.Comment: 7 pp. Cryogenic Engineering Conference and International Cryogenic Materials Conference CEC-ICMC 2011, 13-17 June 2011. Spokane, Washingto

Comparison of regulatory regions in the mitochondrial genomes of grasses

Abstract only availableRegulation of transcription in plant mitochondria is not well understood. The recent sequencing of the mitochondrial genomes of 10 closely related grasses allowed a comparative analysis of regulatory regions. To look for conserved regions and potential “swapped” regulatory regions, we have performed a comparative analysis of the upstream and downstream regions of all of the protein-coding genes in the mitochondrial genomes of eleven grasses: five mitochondrial types of maize (two fertile and three cytoplasmic male sterile), three other taxa within the genus (Zea mays ssp. parviglumis, Z. luxurians, Z. perennis), two close relatives (Tripsacum dactyloides, Sorghum bicolor), and an outgroup, rice. These genomes contain an average of 35 protein-coding genes, composed of 40 transcriptional units. Our analyses examined 1000 base pairs (bp) upstream of the first exon of each transcriptional unit and 1000 bp downstream of its last exon. The reference genome was NB, the most common fertile maize mitochondrial genotype. Compared with the genes from NB, more than half of the mitochondrial genes in the other genomes contain sequences that flank different genes in NB; we refer to these as “swapped” regions. More than 25% of the translocated sequences are longer than 100 bp, and 21 are greater than 500 bp. The longer sequences are more likely to have a regulatory function. In addition, some of these regions were found multiple times: 12 of the translocated gene-flanking regions were found flanking five or more other genes; four had sequences that were flanking ten or more. Furthermore, in Z. luxurians, Z. perennis and T. dactyloides, the co-transcribed 18S and 5S ribosomal RNA genes have been translocated immediately upstream of the start of cox1, with the 5S rRNA 3' end only 80 bp from the start of cox1 exon 1. This is a position that is difficult to rectify with the divergent transcriptional needs of the two types of genes.Plant Genomics Internship @ M

Establishing the ratio of rock salts and organic compounds to reduce the number of Chloride and Sodium ions in the soil when de-icing roads

The research analyzes the amount of salt being dumped onto roads and its effect on trees, specifically the Red Maple and Eastern Hemlock. The goal is to find an alternative to rock salt without completely eliminating its use. The experiment involves using three different alternatives-volcanic mineral, beet juice, cheese brine-and constructing a ratio between a baseline amount of salt and alternative. The result of this is to find the smallest amount of salt needed to efficiently melt ice and cause least damage to trees. Analyzing leaf water content will show which alternative works best

Fermilab SRF cryomodule operational experience

Fermi National Accelerator Laboratory is constructing an Advanced Accelerator Research and Development facility at New Muon Lab. The cryogenic infrastructure in support of the initial phase of the facility consists of two Tevatron style standalone refrigerators, cryogenic distribution system as well as an ambient temperature pumping system to achieve 2 K operations with supporting purification systems. During this phase of the project a single Type III plus 1.3 GHz cryomodule was installed, cooled and tested. Design constraints of the cryomodule required that the cryomodule individual circuits be cooled at predetermined rates. These constraints required special design solutions to achieve. This paper describes the initial cooldown and operational experience of a 1.3 GHz cryomodule using the New Muon Lab cryogenic system.Comment: 7 pp. Cryogenic Engineering Conference and International Cryogenic Materials Conference CEC-ICMC 2011 13-17 June 2011, Spokane, Washingto

Diversity, competition, extinction: the ecophysics of language change

As early indicated by Charles Darwin, languages behave and change very much like living species. They display high diversity, differentiate in space and time, emerge and disappear. A large body of literature has explored the role of information exchanges and communicative constraints in groups of agents under selective scenarios. These models have been very helpful in providing a rationale on how complex forms of communication emerge under evolutionary pressures. However, other patterns of large-scale organization can be described using mathematical methods ignoring communicative traits. These approaches consider shorter time scales and have been developed by exploiting both theoretical ecology and statistical physics methods. The models are reviewed here and include extinction, invasion, origination, spatial organization, coexistence and diversity as key concepts and are very simple in their defining rules. Such simplicity is used in order to catch the most fundamental laws of organization and those universal ingredients responsible for qualitative traits. The similarities between observed and predicted patterns indicate that an ecological theory of language is emerging, supporting (on a quantitative basis) its ecological nature, although key differences are also present. Here we critically review some recent advances lying and outline their implications and limitations as well as open problems for future research.Comment: 17 Pages. A review on current models from statistical Physics and Theoretical Ecology applied to study language dynamic

Assistive tool for collaborative learning of conceptual structures

The final publication is available at link.springer.comThere is a demand for computational methods assisting learners to generate relevantassociations for current context. Many concepts in natural language have ambiguous meaningsimplying alternative ways to define associations for them. It is crucial to develop collaborativemethods that support free experiments with promising conceptual structures in learning.Methods for evaluating these structures in respect to the person’s needs are also required. Wepropose a new collaborative ideation scheme and based on that we have implemented anassistive tool for learning conceptual structures in a collaborative Web environment.Peer reviewe