Development of manufacturing techniques for application of high performance cryogenic insulation Final report, Jun. 21 - Oct. 20, 1967

High performance insulation design, and manufacturing plan of torus tank for Saturn 5 vehicl

Experimental Replication of Relict "Dusty" Olivine in Type 1B Chondrules

Introduction: Relict "dusty" olivine is considered to be a remnants of previous chondrule forming events based on petrographic and chemical evidence. Dynamic crystallization experiments confirm that dusty olivine can be produced by reduction of FeO-rich olivine in Unequilibrated Ordinary Chondrite (UOC) material. The results of these experiments compliment those of who also produced dusty olivine, but from synthetic starting materials. Techniques: Dynamic crystallization experiments were conducted in which UOC material was reduced in presence of graphite. Starting material was coarsely ground GR095554 or WSG95300 that contained olivine of Fo 65-98. Approximately 75 mg. of UOC material was placed in a graphite crucible and sealed in an evacuated silica tube. The tube was suspended in a gas-mixing furnace operated at 1 log unit below the IW buffer. The experiments were as brief as 1.5 hrs up to 121 hrs. Results: Dusty olivine was produced readily in experiments melted at 1400 C for I hr. and cooled between 5 and 100 C/hr or melted at 1300-1400 C for 24 hours. Fe-rich olivine (dusty olivine precursors) that have been partially reduced were common in the experiments melted at 1400 C and cooled at 1000 C/hr or melted at 1200 C for 24 hrs. Relict olivine is absent in experiments melted at 1400 for 24 hrs, melted above 1400 C, or cooled more slowly than 10 C/hr. Relict olivine in the experiments has minimum Fo value of 83 . Thus even in the shortest experiments the most Fe-rich olivine has been altered significantly. The precursor olivine disappears in a few to many hours depending on temperature. The experiments show Fe-rich olivine in all stages of transition to the new dusty form. The olivine is reduced to form dusty olivine in a matter of a few hours at temperatures less than 1400 C and in minutes at higher temperatures. The reduction appears to proceed from the rim of the crystal inward with time. The reduction appears initially rectilinear as if controlled by crystallography, but with time Fe-metal blebs are randomly distributed throughout the olivine. In a given experiment, dusty olivine can be found in varying stages of development, but in the longest experiments, the Fe-metal blebs are dominant and they appear to be migrating out of the olivine. The composition of the dusty olivine ranges from Fo 94-99. The Cr, Mn, and Ca content of the newly formed, dusty olivine is slightly less on average that the precursor olivine, but is till with the range of type 1 olivine. Chadacrysts in the low Ca pyroxene are most common in the higher temperature, more slowly cooled experiments and range in composition from Fo 90-99. Application to chondrule formation: These experiments place time-temperature limits on the preservation of Fe-rich olivine and the production of dusty olivine during chondrule forming events. The reduction process proceeds in a few hours at temperatures above 1400 C and in 10's of hours at temperature between 1200 and 1300 C. This result further confirms th at chondrules form in a few hours to days as suggested earlier. The experiments also confirm that dusty olivine can form from typical Fe-rich olivine in UOC material during the recycling of such olivine in the chondrule forming process

Efficient Estimation of Heat Kernel PageRank for Local Clustering

Given an undirected graph G and a seed node s, the local clustering problem aims to identify a high-quality cluster containing s in time roughly proportional to the size of the cluster, regardless of the size of G. This problem finds numerous applications on large-scale graphs. Recently, heat kernel PageRank (HKPR), which is a measure of the proximity of nodes in graphs, is applied to this problem and found to be more efficient compared with prior methods. However, existing solutions for computing HKPR either are prohibitively expensive or provide unsatisfactory error approximation on HKPR values, rendering them impractical especially on billion-edge graphs. In this paper, we present TEA and TEA+, two novel local graph clustering algorithms based on HKPR, to address the aforementioned limitations. Specifically, these algorithms provide non-trivial theoretical guarantees in relative error of HKPR values and the time complexity. The basic idea is to utilize deterministic graph traversal to produce a rough estimation of exact HKPR vector, and then exploit Monte-Carlo random walks to refine the results in an optimized and non-trivial way. In particular, TEA+ offers practical efficiency and effectiveness due to non-trivial optimizations. Extensive experiments on real-world datasets demonstrate that TEA+ outperforms the state-of-the-art algorithm by more than four times on most benchmark datasets in terms of computational time when achieving the same clustering quality, and in particular, is an order of magnitude faster on large graphs including the widely studied Twitter and Friendster datasets.Comment: The technical report for the full research paper accepted in the SIGMOD 201

Experimentally reproduced relict enstatite in porphyritic chondrules of enstatite chondrite composition

Experiments are presented that test a model for the origin of porphyritic pyroxene (PP) chondrules in enstatite chondrites that contain phenocrysts of enstatite with blue cathodoluminescence (CL) set in a matrix of radial, dendritic enstatite with red CL. Established one-atmosphere, gas-mixing techniques were used. Relict enstatite phenocrysts with blue CL in a matrix of coarsely radial to dendritic enstatite with red CL were successfully produced. The relict crystals are preserved in runs with a melt time of 36 minutes or less at 1537 C. The relicts remain angular with smooth crystal/melt interfaces, and thus melting has occurred uniformly. Partial melting does occur along fractures produced when the blue CL enstatite was initially grown and cooled through the proto/ortho enstatite transition with the attendent volume change. There is either reaction with the melt and diffusion of Mn and Cr into the blue CL En, or there is an overgrowth of red CL En along the fractures. The bulk of the relicts remain blue. The melt enclosing the relicts crystalized to a coarsely radial to dendritic to micro porphyritic texture comprised of enstatite that has a bright red CL with decreasing melt time. The blue CL En has Mn and Cr contents at or below detection limits of the electron probe as described in earlier studies and in natural blue CL En. In the red CL En in this study, the Mn, Al2O3, and Cr are at previously observed levels and the levels change rapidly

Cattle Grubs and Their Control in South Dakota

The purposes of the research work carried on from 1947 to 1953 by the South Dakota Agricultural Experiment Station were: to study the distribution and seasonal abundance of cattle grubs in South Dakota; to measure effects of grub infestations and methods of control on rates of gain of feed lot cattle; to evaluate and improve methods of control; and to investigate the practicability of cattle grub control on an area or community-wide basis

The Green Eating Project: web-based intervention to promote environmentally conscious eating behaviours in US university students

Objective: To investigate the effectiveness of an online, interactive intervention, referred to as the Green Eating (GE) Project, to motivate university students to adopt GE behaviours. Design: The study was quasi-experimental and integrated into courses for credit/extra credit. Courses were randomly stratified into experimental or non-treatment control. The 5-week intervention consisted of four modules based on different GE topics. Participants completed the GE survey at baseline (experimental, n 241; control, n 367) and post (experimental, n 187; control, n 304). The GE survey has been previously validated and consists of Transtheoretical Model constructs including stage of change (SOC), decisional balance (DB: Pros and Cons) and self-efficacy (SE: School and Home) as well as behaviours for GE. Modules contained basic information regarding each topic and knowledge items to assess content learning. Setting: The GE Project took place at a public university in the north-eastern USA. Subjects: Participants were full-time students between the ages of 18 and 24 years. Results: The GE Project was effective in significantly increasing GE behaviours, DB Pros, SE School and knowledge in experimental compared with control, but did not reduce DB Cons or increase SE Home. Experimental participants were also more likely to be in later SOC for GE at post testing. Conclusions: The GE Project was effective in increasing GE behaviours in university students. Motivating consumers towards adopting GE could assist in potentially mitigating negative consequences of the food system on the environment. Future research could tailor the intervention to participant SOC to further increase the effects or design the modules for other participants

Lessons Learned: Recruiting Aging Adults for Research

Aging adults are the fastest-growing population in the United States, but they are underrepresented in health care research. Evidence-based decisions for aging adults need to be made using research done with this population. However, recruiting aging adults into research has many challenges. This article presents multiple cases of recruiting aging adults into nutrition research studies in 3 different US geographic locations. The challenges, successes, and lessons learned are presented. The lessons learned can provide guidance to others already doing research with aging adults and those clinical and community dietitians who want to start doing research with aging adults