Objective, Structured Proforma to Score the Merit of Scientific Presentations.

PubMed

Agarwal, Nayan; Thawani, Rajat; Gupta, Setu; Sharma, Arun; Dhaliwal, Upreet

2015-12-01

Around 100,000 medical conferences are organized all over the world and hence, they form an integral part of a medical professional's life. Oral presentations, especially award sessions, are judged by a panel of faculty judges who score individual presentations on various aspects including content, delivery and submission. Our objective was to compare the scores given by student-judges and faculty-judges for scientific presentations using the standardized score sheet. An objective, structured score-sheet was designed using existing literature. Five presentations, all made using PowerPoint, were judged using the structured score-sheet by seven student-judges and two-faculty judges. The mean score of all the score-sheets (n = 45) was 38.5 + 5.4 (out of a maximum score of 50). There was no statistical difference between mean scores assigned by students or faculty (p = 0.2). Thus, an objective, structured score sheet like ours, when used to judge scientific presentations, gave uniform results even when judges hailed from different levels of the medical hierarchy.

Intraoperative use of a reflective blanket (Sirius rescue sheet) for temperature management in dogs less than 10 kg.

PubMed

Tünsmeyer, J; Bojarski, I; Nolte, I; Kramer, S

2009-07-01

To compare the effects of the Sirius rescue sheet with gel pads versus gel pads alone on intraoperative body temperature in dogs less than 10 kg. Forty small breed dogs undergoing elective surgical procedures were randomly assigned to two groups. One group was intraoperatively laid on warmed gel pads, and the other group was additionally wrapped in a Sirius rescue sheet. Oesophageal body temperature was determined every 10 minutes and compared between groups. Temperature of gel pads was measured preoperatively and postoperatively to compare heat loss of the gel pads between groups. The body temperature of dogs wrapped with the Sirius rescue sheet increased intraoperatively. In dogs just lying on warmed gel pads, a decrease in mean body temperature was revealed and mean body temperatures differed between groups after 40 minutes. Extent of heat loss from the gel pads did not differ between the groups. The Sirius rescue sheet, used in addition to warmed gel pads, led to higher intraoperative body temperatures in small breed dogs undergoing surgical procedures to the extremities and the head. The cost-effectiveness and ease of handling make this a useful addition to clinical practice.

3D 14N/1H Double Quantum/1H Single Quantum Correlation Solid-State NMR for Probing Parallel and Anti-Parallel Beta-Sheet Arrangement of Oligo-Peptides at Natural Abundance.

PubMed

Hong, You-Lee; Asakura, Tetsuo; Nishiyama, Yusuke

2018-05-08

β-sheet structure of oligo- and poly-peptides can be formed in anti-parallel (AP)- and parallel (P)-structure, which is the important feature to understand the structures. In principle, P- and AP-β-sheet structures can be identified by the presence (AP) and absence (P) of the interstrand 1HNH/1HNH correlations on a diagonal in 2D 1H double quantum (DQ)/1H single quantum (SQ) spectrum due to the different interstrand 1HNH/1HNH distances between these two arrangements. However, the 1HNH/1HNH peaks overlap to the 1HNH3+/1HNH3+ peaks, which always give cross peaks regardless of the β-sheet arrangement. The 1HNH3+/1HNH3+ peaks disturb the observation of the presence/absence of 1HNH/1HNH correlations and the assignment of 1HNH and 1HNH3+ is not always available. Here, 3D 14N/1H DQ/1H SQ correlation solid-state NMR experiments at fast magic angle spinning (70 kHz) are introduced to distinguish AP and P β-sheet structure. The 14N dimension allows the separate observation of 1HNH/1HNH peaks from 1HNH3+/1HNH3+ peaks with clear assignment of 1HNH and 1HNH3+. In addition, the high natural abundance of 1H and 14N enables 3D 14N/1H DQ/1H SQ experiments of oligo-alanines (Ala3-6) in four hours without any isotope labelling. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Incorporation of ice sheet models into an Earth system model: Focus on methodology of coupling

NASA Astrophysics Data System (ADS)

Rybak, Oleg; Volodin, Evgeny; Morozova, Polina; Nevecherja, Artiom

2018-03-01

Elaboration of a modern Earth system model (ESM) requires incorporation of ice sheet dynamics. Coupling of an ice sheet model (ICM) to an AOGCM is complicated by essential differences in spatial and temporal scales of cryospheric, atmospheric and oceanic components. To overcome this difficulty, we apply two different approaches for the incorporation of ice sheets into an ESM. Coupling of the Antarctic ice sheet model (AISM) to the AOGCM is accomplished via using procedures of resampling, interpolation and assigning to the AISM grid points annually averaged meanings of air surface temperature and precipitation fields generated by the AOGCM. Surface melting, which takes place mainly on the margins of the Antarctic peninsula and on ice shelves fringing the continent, is currently ignored. AISM returns anomalies of surface topography back to the AOGCM. To couple the Greenland ice sheet model (GrISM) to the AOGCM, we use a simple buffer energy- and water-balance model (EWBM-G) to account for orographically-driven precipitation and other sub-grid AOGCM-generated quantities. The output of the EWBM-G consists of surface mass balance and air surface temperature to force the GrISM, and freshwater run-off to force thermohaline circulation in the oceanic block of the AOGCM. Because of a rather complex coupling procedure of GrIS compared to AIS, the paper mostly focuses on Greenland.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wemmer, D.E.; Kumar, N.V.; Metrione, R.M.

Toxin II from Radianthus paumotensis (Rp/sub II/) has been investigated by high-resolution NMR and chemical sequencing methods. Resonance assignments have been obtained for this protein by the sequential approach. NMR assignments could not be made consistent with the previously reported primary sequence for this protein, and chemical methods have been used to determine a sequence with which the NMR data are consistent. Analysis of the 2D NOE spectra shows that the protein secondary structure is comprised of two sequences of ..beta..-sheet, probably joined into a distorted continuous sheet, connected by turns and extended loops, without any regular ..cap alpha..-helical segments.more » The residues previously implicated in activity in this class of proteins, D8 and R13, occur in a loop region.« less

Improving the knowledge of labour and delivery nurses in India: a randomized controlled trial of mentoring and case sheets in primary care centres.

PubMed

Bradley, Janet; Jayanna, Krishnamurthy; Shaw, Souradet; Cunningham, Troy; Fischer, Elizabeth; Mony, Prem; Ramesh, B M; Moses, Stephen; Avery, Lisa; Crockett, Maryanne; Blanchard, James F

2017-01-07

Birthing in health facilities in India has increased over the last few years, yet maternal and neonatal mortality rates remain high. Clinical mentoring with case sheets or checklists for nurses is viewed as essential for on-going knowledge transfer, particularly where basic training is inadequate. This paper summarizes a study of the effect of such a programme on staff knowledge and skills in a randomized trial of 295 nurses working in 108 Primary Health Centres (PHCs) in Karnataka, India. Stratifying by district, half of the PHCs were randomly assigned to be intervention sites and provided with regular mentoring visits where case sheet/checklists were a central job and teaching aid, and half to be control sites, where no support was provided except provision of case sheets. Nurses' knowledge and skills around normal labour, labour complications and neonate issues were tested before the intervention began and again one year later. Univariate and multivariate analyses were conducted to examine the effect of mentoring and case sheets. Overall, on none of the 3 measures, did case sheet use without mentoring add anything to the basic nursing training when controlling for other factors. Only individuals who used both case-sheets and received mentoring scored significantly higher on the normal labour and neonate indices, scoring almost twice as high as those who only used case-sheets. This group was also associated with significantly higher scores on the complications of labour index, with their scores 2.3 times higher on average than the case sheet only control group. Individuals from facilities with 21 or more deliveries in a month tended to fare worse on all 3 indices. There were no differences in outcomes according to district or years of experience. This study demonstrates that provision of case sheets or checklists alone is insufficient to improve knowledge and practices. However, on-site mentoring in combination with case sheets can have a demonstrable effect on improving nurse knowledge and skills around essential obstetric and neonatal care in remote rural areas of India. We recommend scaling up of this mentoring model in order to improve staff knowledge and skills and reduce maternal and neonatal mortality in India. This study is registered at clinicaltrials.gov, Identifier No. NCT02004912 , November 27, 2013.

A Multidisciplinary First-Year Seminar about Tuberculosis.

ERIC Educational Resources Information Center

Fluck, Richard A.

2001-01-01

Describes a writing intensive seminar for college freshman. Includes goals, reading assignments, writing assignments, and group projects. Provides web-based resources on tuberculosis along with an evaluation sheet for web site reviews. Concludes that students exhibited great interest in the topic and course feedback was positive. (DLH)

AVAILABLE INSTRUCTIONAL MATERIALS.

ERIC Educational Resources Information Center

Indiana State Univ., Terre Haute.

THE INSTRUCTIONAL MATERIALS INCLUDE PROGRAM BROCHURES, CHARTS, COURSE OUTLINES, OVERHEAD TRANSPARENCIES, ASSIGNMENT SHEETS, STUDENT MANUALS, TEACHER MANUALS, TECHNICAL INFORMATION, AND RELATED INFORMATION IN VOCATIONAL EDUCATION. A BRIEF NOTE DESCRIBES EACH. (EM)

The Effect on One's Own Performance of Evaluating Peers.

ERIC Educational Resources Information Center

Cohen, Stuart J.

Fifty-three high school males took a minicourse on library usage. All were randomly assigned a topic and given response sheets requiring the use of dictionaries, encyclopedias, periodicals, and books. In a discussion session, all received instructional handouts. Students were assigned either to evaluating two peers' pretests (experimental) or…

ELECTRICAL AND ELECTRONIC INDUSTRIAL CONTROL. BASIC ELECTRICITY, UNIT 3, ASSIGNMENTS.

ERIC Educational Resources Information Center

SUTTON, MACK C.

THIS GUIDE IS FOR INDIVIDUAL STUDENT USE IN STUDYING BASIC ELECTRICAL FUNDAMENTALS IN ELECTRICAL-ELECTRONIC PROGRAMS. IT WAS DEVELOPED BY AN INSTRUCTIONAL MATERIALS SPECIALIST AND ADVISERS. THE COURSE OBJECTIVE IS TO DEVELOP AN UNDERSTANDING OF DIRECT CURRENT FUNDAMENTALS. EACH OF THE 10 ASSIGNMENT SHEETS PROVIDES THE LESSON SUBJECT, PURPOSE,…

ELECTRICAL AND ELECTRONIC INDUSTRIAL CONTROL. D-C MAGNETIC MOTOR CONTROL, UNIT 7, ASSIGNMENTS.

ERIC Educational Resources Information Center

SUTTON, MACK C.

THIS GUIDE IS FOR INDIVIDUAL STUDENT USE IN STUDYING DIRECT CURRENT MAGNETIC MOTOR CONTROL IN ELECTRICAL-ELECTRONIC PROGRAMS. IT WAS DEVELOPED BY AN INSTRUCTIONAL MATERIALS SPECIALIST AND ADVISERS. EACH OF THE 15 ASSIGNMENT SHEETS PROVIDES THE LESSON SUBJECT, PURPOSE, INTRODUCTORY INFORMATION, STUDY REFERENCES, AND PROBLEMS. SOME OF THE LESSONS…

ELECTRICAL AND ELECTRONIC INDUSTRIAL CONTROL. A-C CONVENTIONAL MAGNETIC MOTOR CONTROL, PART I, UNIT 5, ASSIGNMENTS.

ERIC Educational Resources Information Center

SUTTON, MACK C.

THIS GUIDE IS FOR INDIVIDUAL STUDENT USE IN STUDYING ALTERNATING CURRENT CONVENTIONAL MAGNETIC MOTOR CONTROL IN ELECTRICAL-ELECTRONIC PROGRAMS. IT WAS DEVELOPED BY AN INSTRUCTIONAL MATERIALS SPECIALIST AND ADVISERS. EACH OF THE 10 ASSIGNMENT SHEETS PROVIDES THE LESSON SUBJECT, PURPOSE, INTRODUCTORY INFORMATION, STUDY REFERENCES, SUPPLEMENTARY…

ELECTRICAL AND ELECTRONIC INDUSTRIAL CONTROL. BASIC ELECTRICITY, UNIT 2, ASSIGNMENTS.

ERIC Educational Resources Information Center

SUTTON, MACK C.

THIS GUIDE IS FOR INDIVIDUAL STUDENT USE IN STUDYING BASIC ELECTRICAL FUNDAMENTALS IN ELECTRICAL-ELECTRONIC PROGRAMS. IT WAS DEVELOPED BY AN INSTRUCTIONAL MATERIALS SPECIALIST AND ADVISERS. THE COURSE OBJECTIVE IS TO DEVELOP AN UNDERSTANDING OF DIRECT CURRENT FUNDAMENTALS. EACH OF THE 15 ASSIGNMENT SHEETS PROVIDES THE LESSON SUBJECT, PURPOSE,…

Prevention of postsurgical scars: comparsion of efficacy and convenience between silicone gel sheet and topical silicone gel.

PubMed

Kim, Sue-Min; Choi, Jung-Sik; Lee, Jung-Ho; Kim, Young-Jin; Jun, Young-Joon

2014-11-01

To date, few studies have compared the effectiveness of topical silicone gels versus that of silicone gel sheets in preventing scars. In this prospective study, we compared the efficacy and the convenience of use of the 2 products. We enrolled 30 patients who had undergone a surgical procedure 2 weeks to 3 months before joining the study. These participants were randomly assigned to 2 treatment arms: one for treatment with a silicone gel sheet, and the other for treatment with a topical silicone gel. Vancouver Scar Scale (VSS) scores were obtained for all patients; in addition, participants completed scoring patient questionnaires 1 and 3 months after treatment onset. Our results reveal not only that no significant difference in efficacy exists between the 2 products but also that topical silicone gels are more convenient to use. While previous studies have advocated for silicone gel sheets as first-line therapies in postoperative scar management, we maintain that similar effects can be expected with topical silicone gel. The authors recommend that, when clinicians have a choice of silicone-based products for scar prevention, they should focus on each patient's scar location, lifestyle, and willingness to undergo scar prevention treatment.

Composite biaxially textured substrates using ultrasonic consolidation

DOEpatents

Blue, Craig A; Goyal, Amit

2013-04-23

A method of forming a composite sheet includes disposing an untextured metal or alloy first sheet in contact with a second sheet in an aligned opposing position; bonding the first sheet to the second sheet by applying an oscillating ultrasonic force to at least one of the first sheet and the second sheet to form an untextured intermediate composite sheet; and annealing the untextured intermediate composite sheet at a temperature lower than a primary re-crystallization temperature of the second sheet and higher than a primary re-crystallization temperature of the first sheet to convert the untextured first sheet into a cube textured sheet, wherein the cube texture is characterized by a .phi.-scan having a FWHM of no more than 15.degree. in all directions, the second sheet remaining untextured, to form a composite sheet.

College Algebra I.

ERIC Educational Resources Information Center

Benjamin, Carl; And Others

Presented are student performance objectives, a student progress chart, and assignment sheets with objective and diagnostic measures for the stated performance objectives in College Algebra I. Topics covered include: sets; vocabulary; linear equations; inequalities; real numbers; operations; factoring; fractions; formulas; ratio, proportion, and…

Developing effective assignment feedback for an interprofessional learning module-An action research project.

PubMed

Strudwick, Ruth; Day, Jane

2015-09-01

The first year interprofessional learning module at University Campus Suffolk (UCS) is delivered to 300 students and the students' assignments are marked by 20 members of staff from different health and social care professions. We were keen to find a way to reduce any inconsistencies and work with both staff and students to ensure that the essay and subsequent feedback were useful for all involved. The aims of the project were to evaluate the current marking process and feedback sheets used for year one inter-professional learning (IPL) marking, and to develop an appropriate marking tool and feedback sheet that would enable markers to provide more consistent feedback to the students. Participatory action research was used with both students and staff members being involved. Focus group and questions were used to ascertain views about the assignment feedback. The feedback from this action learning project helped us to enhance the feedback for students. There was also an increase in engagement with the assessment and feedback process amongst both staff and students. Copyright © 2015 Elsevier Ltd. All rights reserved.

Enhanced osseointegration of titanium implants in a rat model of osteoporosis using multilayer bone mesenchymal stem cell sheets

PubMed Central

Duan, Yan; Ma, Wei; Li, Dehua; Wang, Tongfei; Liu, Baolin

2017-01-01

The present study aimed to investigate whether bone marrow-derived mesenchymal stem cell (BMSC) sheets combined with titanium implants enhanced implant osseointegration in an ovariectomized (OVX) rat model of osteoporosis. Sprague-Dawley rats were randomly assigned into a test group and control group. Allogenic BMSCs were collected from the rats, cultured and stored via cryopreservation. At 6 months post-ovariectomy, establishment of the OVX model was confirmed by micro-computed tomography (CT) measurements. BMSC sheets were subsequently layered and wrapped over titanium implants for implantation. Unmodified implants served as the control. At 8 weeks post-implantation, samples were observed by micro-CT reconstruction and histomorphometric evaluation. Micro-CT reconstruction identified a marked improvement in the surrounding bone volume following treatment, with data analyses indicating a significant increase in bone volume in the BMSC-implant group compared with the control implant group (P<0.05). In addition, histological staining identified new bone formation and an increased rate of bone-implant contact surrounding the BMSC-implant constructs. These results indicate that the use of BMSC sheets as a novel tissue engineering approach improves the osseointegration of titanium implants in an osteoporosis model. This method may expand the operative indications in patients with osteoporosis and improve the success rate of clinical dental implant treatments. PMID:29250137

The cosmic web and the orientation of angular momenta

NASA Astrophysics Data System (ADS)

Libeskind, Noam I.; Hoffman, Yehuda; Knebe, Alexander; Steinmetz, Matthias; Gottlöber, Stefan; Metuki, Ofer; Yepes, Gustavo

2012-03-01

We use a 64 h-1 Mpc dark-matter-only cosmological simulation to examine the large-scale orientation of haloes and substructures with respect to the cosmic web. A web classification scheme based on the velocity shear tensor is used to assign to each halo in the simulation a web type: knot, filament, sheet or void. Using ˜106 haloes that span ˜3 orders of magnitude in mass, the orientation of the halo's spin and the orbital angular momentum of subhaloes with respect to the eigenvectors of the shear tensor is examined. We find that the orbital angular momentum of subhaloes tends to align with the intermediate eigenvector of the velocity shear tensor for all haloes in knots, filaments and sheets. This result indicates that the kinematics of substructures located deep within the virialized regions of a halo is determined by its infall which in turn is determined by the large-scale velocity shear, a surprising result given the virialized nature of haloes. The non-random nature of subhalo accretion is thus imprinted on the angular momentum measured at z= 0. We also find that the haloes' spin axis is aligned with the third eigenvector of the velocity shear tensor in filaments and sheets: the halo spin axis points along filaments and lies in the plane of cosmic sheets.

37 CFR 1.76 - Application data sheet.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 37 Patents, Trademarks, and Copyrights 1 2012-07-01 2012-07-01 false Application data sheet. 1.76... Application data sheet. (a) Application data sheet. An application data sheet is a sheet or sheets, that may... bibliographic data, arranged in a format specified by the Office. An application data sheet must be titled...

Microwave. Instructor's Edition. Louisiana Vocational-Technical Education.

ERIC Educational Resources Information Center

Blanton, William

This publication contains related study assignments and job sheets for a course in microwave technology. The course is organized into 12 units covering the following topics: introduction to microwave, microwave systems, microwave oscillators, microwave modulators, microwave transmission lines, transmission lines, detectors and mixers, microwave…

Micro-fluidic partitioning between polymeric sheets for chemical amplification and processing

DOEpatents

Anderson, Brian L.

2017-01-24

A system for fluid partitioning for chemical amplification or other chemical processing or separations of a sample, comprising a first dispenser of a first polymeric sheet, wherein the first polymeric sheet contains chambers; a second dispenser of a second polymeric sheet wherein the first dispenser and the second dispenser are positioned so that the first polymeric sheet and the second polymeric sheet become parallel; a dispenser of the fluid positioned to dispense the fluid between the first polymeric sheet and the second polymeric sheet; and a seal unit that seals the first polymeric sheet and the second polymeric sheet together thereby sealing the sample between the first polymeric sheet and the second polymeric sheet and partitioning the fluid for chemical amplification or other chemical processing or separations.

Micro-fluidic partitioning between polymeric sheets for chemical amplification and processing

DOEpatents

Anderson, Brian L.

2015-05-26

A system for fluid partitioning for chemical amplification or other chemical processing or separations of a sample, comprising a first dispenser of a first polymeric sheet, wherein the first polymeric sheet contains chambers; a second dispenser of a second polymeric sheet wherein the first dispenser and the second dispenser are positioned so that the first polymeric sheet and the second polymeric sheet become parallel; a dispenser of the fluid positioned to dispense the fluid between the first polymeric sheet and the second polymeric sheet; and a seal unit that seals the first polymeric sheet and the second polymeric sheet together thereby sealing the sample between the first polymeric sheet and the second polymeric sheet and partitioning the fluid for chemical amplification or other chemical processing or separations.

The Cryosphere Model Comparison Tool (CmCt): Ice Sheet Model Validation and Comparison Tool for Greenland and Antarctica

NASA Astrophysics Data System (ADS)

Simon, E.; Nowicki, S.; Neumann, T.; Tyahla, L.; Saba, J. L.; Guerber, J. R.; Bonin, J. A.; DiMarzio, J. P.

2017-12-01

The Cryosphere model Comparison tool (CmCt) is a web based ice sheet model validation tool that is being developed by NASA to facilitate direct comparison between observational data and various ice sheet models. The CmCt allows the user to take advantage of several decades worth of observations from Greenland and Antarctica. Currently, the CmCt can be used to compare ice sheet models provided by the user with remotely sensed satellite data from ICESat (Ice, Cloud, and land Elevation Satellite) laser altimetry, GRACE (Gravity Recovery and Climate Experiment) satellite, and radar altimetry (ERS-1, ERS-2, and Envisat). One or more models can be uploaded through the CmCt website and compared with observational data, or compared to each other or other models. The CmCt calculates statistics on the differences between the model and observations, and other quantitative and qualitative metrics, which can be used to evaluate the different model simulations against the observations. The qualitative metrics consist of a range of visual outputs and the quantitative metrics consist of several whole-ice-sheet scalar values that can be used to assign an overall score to a particular simulation. The comparison results from CmCt are useful in quantifying improvements within a specific model (or within a class of models) as a result of differences in model dynamics (e.g., shallow vs. higher-order dynamics approximations), model physics (e.g., representations of ice sheet rheological or basal processes), or model resolution (mesh resolution and/or changes in the spatial resolution of input datasets). The framework and metrics could also be used for use as a model-to-model intercomparison tool, simply by swapping outputs from another model as the observational datasets. Future versions of the tool will include comparisons with other datasets that are of interest to the modeling community, such as ice velocity, ice thickness, and surface mass balance.

Method for heating, forming and tempering a glass sheet

DOEpatents

Boaz, Premakaran Tucker; Sitzman, Gary W.

1998-01-01

A method for heating, forming and tempering a glass sheet including the steps of heating at least one glass sheet to at least a first predetermined temperature, applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature, forming the glass sheet to a predetermined configuration, and cooling an outer surface of the glass sheet to at least a third predetermined temperature to temper the glass sheet.

Method for heating, forming and tempering a glass sheet

DOEpatents

Boaz, P.T.; Sitzman, G.W.

1998-10-27

A method for heating, forming and tempering a glass sheet is disclosed including the steps of heating at least one glass sheet to at least a first predetermined temperature, applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature, forming the glass sheet to a predetermined configuration, and cooling an outer surface of the glass sheet to at least a third predetermined temperature to temper the glass sheet. 2 figs.

Dehydration of main-chain amides in the final folding step of single-chain monellin revealed by time-resolved infrared spectroscopy

PubMed Central

Kimura, Tetsunari; Maeda, Akio; Nishiguchi, Shingo; Ishimori, Koichiro; Morishima, Isao; Konno, Takashi; Goto, Yuji; Takahashi, Satoshi

2008-01-01

Kinetic IR spectroscopy was used to reveal β-sheet formation and water expulsion in the folding of single-chain monellin (SMN) composed of a five-stranded β-sheet and an α-helix. The time-resolved IR spectra between 100 μs and 10 s were analyzed based on two consecutive intermediates, I1 and I2, appearing within 100 μs and with a time constant of ≈100 ms, respectively. The initial unfolded state showed broad amide I′ corresponded to a fluctuating conformation. In contrast, I1 possessed a feature at 1,636 cm−1 for solvated helix and weak features assignable to turns, demonstrating the rapid formation of helix and turns. I2 possessed a line for solvated helix at 1,637 cm−1 and major and minor lines for β-sheet at 1,625 and 1,680 cm−1, respectively. The splitting of the major and minor lines is smaller than that of the native state, implying an incomplete formation of the β-sheet. Furthermore, both major and minor lines demonstrated a low-frequency shift compared to those of the native state, which was interpreted to be caused by hydration of the CO group in the β-sheet. Together with the identification of solvated helix, the core domain of I2 was interpreted as being hydrated. Finally, slow conversion of the water-penetrated core of I2 to the dehydrated core of the native state was observed. We propose that both the expulsion of water, hydrogen-bonded to main-chain amides, and the completion of the secondary structure formation contribute to the energetic barrier of the rate-limiting step in SMN folding. PMID:18757727

Interface between hospital and fire authorities--a concept for management of incidents in hospitals.

PubMed

Gretenkort, Peter; Harke, Henning; Blazejak, Jan; Pache, Bernd; Leledakis, Georgios

2002-01-01

Although every hospital needs a security plan for the support of immobile patients who do not possess autonomous escape capabilities, little information exists to assist in the development of practical patient evacuation methods. 1) In hospitals during disasters, incident leadership of the fire authorities can be supported effectively by hospital executives experienced in the management of mass casualties; and 2) As an alternative for canvas carry sheets, rescue drag sheets can be employed for emergency, elevator-independent, patient evacuation. A hospital evacuation exercise was planned and performed to obtain experiences in incident command and to permit calculation of elevator-independent patient transport times. Performance of incident leadership was observed by means of pre-defined checklists. The effectiveness and efficiency of carrying teams with five persons each were compared to those with a rescue drag sheet employed by a single person. Incident command for hospitals during a disaster is enhanced considerably by pre-defined and trained executives who are placed at the immediate disposal of the fire authorities. For elevator-independent patient transport, the rescue drag sheet was superior to conventional carrying measures because of a reduced number of transport personnel required to move each patient. With this method, patient transport times averaged 54 m/min. flat and 18 seconds for one floor descent. Experiences from a hospital during an evacuation exercise provided decision criteria for changes in the disaster preparedness plan. Hospital incident leadership was assigned to executives-in-charge in close co-operation with the fire authorities. All beds were equipped with a rescue drag sheet. Both concepts may help to cope with an emergency evacuation of a hospital.

Higher-order molecular packing in amyloid-like fibrils constructed with linear arrangements of hydrophobic and hydrogen-bonding side-chains.

PubMed

Saiki, Masatoshi; Honda, Shinya; Kawasaki, Kazunori; Zhou, Deshan; Kaito, Akira; Konakahara, Takeo; Morii, Hisayuki

2005-05-13

Various mutants of the protein fragment, barnase module-1 (1-24) were investigated in order to reveal the structural principle of amyloid-like fibrils. By means of circular dichroism spectroscopy, X-ray diffraction, electron microscopy, and thioflavin T binding assay, we found that the molecules containing two beta-strands and an intervening turn structure are assembled to form a cross-beta structure. Stabilization by both the hydrophobic interactions and hydrogen bonding between the respective paired side-chains on the coupled beta-strands was essential for fibril formation. These two types of interaction can also arrange the corresponding residues in lines on both sheet surfaces of protofilaments with a cross-beta structure. This leads to the most probable fibril structure constructed with the line-matching interactions between protofilaments. Consideration of the geometrical symmetry resulted in our finding that a limited number of essential models for molecular packing in fibril structure are stable, which would rationally explain the occurrence of two or three morphologies from an identical molecular species. The ribbon-like fibrils exhibited striped texture along the axis, which was assigned to a stacked two-sheet repeat as a structural unit. The comprehensively proposed structural model, that is, the sheet-sheet interaction between left-handed cross-beta structures, results in a slightly right-handed twist of beta-sheet stacking, which reasonably elucidates the intrinsic sizes of the fibril width and its helical period along the fibril axis, as the bias in the orientation of the hydrogen-bonded beta-strand pair at the lateral edge is larger than that at the central protofilament.

Polymer based nanocomposites with nanofibers and exfoliated clay

NASA Technical Reports Server (NTRS)

Meador, Michael A.; Reneker, Darrell H.

2005-01-01

Polymer solutions, containing clay sheets, were electrospun into nanofibers and microfibers that contained clay sheets inside. Controllable removal of polymer by plasma etching from the surface of fibers revealed the arrangement of clay. The shape, flexibility, size distribution and arrangement of clay sheets were observed by transmission and scanning electron microscopy. The clay sheets were partially aligned in big fibers with normal direction of clay sheets perpendicular to fiber axis. Crumpling of clay sheets inside fibers was observed when the fiber diameter was comparable to the lateral size of clay sheets. Single sheets of clay were observed both by catching clay sheets dispersed in water with electrospun nanofiber mats and by the deliberate removal of most of the polymer in the fibers. Thin, flexible gas barrier films, that are reasonably strong, were assembled from clay sheets and polymer nanofibers. Structure of composite films was characterized with scanning electron microscopy. Continuous film of clay sheets were physically attached to the surface of fiber mats. Spincoating film of polymer and clay sheets was reinforced by electrospun fiber scaffold. Certain alignment of clay sheets was observed in the vicinity of fibers.

Validation of Welding Curriculum Manual.

ERIC Educational Resources Information Center

Stone, Sheila D.

A study was conducted to validate the welding curriculum materials developed and published by the Oklahoma State Department of Vocational and Technical Education. Twelve instructors collected achievement data (unit tests, assignment sheets, and evaluation forms) concerning the performance of 280 students on a total of 46 instructional units. Item…

Horizontal electromagnetic casting of thin metal sheets

DOEpatents

Hull, John R.; Lari, Robert J.; Praeg, Walter F.; Turner, Larry R.

1987-01-01

Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.

Horizontal electromagnetic casting of thin metal sheets

DOEpatents

Hull, John R.; Lari, Robert J.; Praeg, Walter F.; Turner, Larry R.

1988-01-01

Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.

Method for heating a glass sheet

DOEpatents

Boaz, Premakaran Tucker

1998-01-01

A method for heating a glass sheet includes the steps of heating a glass sheet to a first predetermined temperature and applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature to allow the glass sheet to be formed.

46 CFR 232.4 - Balance sheet accounts.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 8 2010-10-01 2010-10-01 false Balance sheet accounts. 232.4 Section 232.4 Shipping... ACTIVITIES UNIFORM FINANCIAL REPORTING REQUIREMENTS Balance Sheet § 232.4 Balance sheet accounts. (a.... (b) Purpose of balance sheet accounts. The balance sheet accounts are intended to disclose the...

46 CFR 232.4 - Balance sheet accounts.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 8 2011-10-01 2011-10-01 false Balance sheet accounts. 232.4 Section 232.4 Shipping... ACTIVITIES UNIFORM FINANCIAL REPORTING REQUIREMENTS Balance Sheet § 232.4 Balance sheet accounts. (a.... (b) Purpose of balance sheet accounts. The balance sheet accounts are intended to disclose the...

Repair Mechanism of Osteochondral Defect Promoted by Bioengineered Chondrocyte Sheet

PubMed Central

Kamei, Naosuke; Adachi, Nobuo; Hamanishi, Michio; Kamei, Goki; Mahmoud, Elhussein Elbadry; Nakano, Tomohiro; Iwata, Takanori; Yamato, Masayuki; Okano, Teruo; Ochi, Mitsuo

2015-01-01

Cell sheet engineering has developed as a remarkable method for cell transplantation. In the field of cartilage regeneration, several studies previously reported that cartilage defects could be regenerated by transplantation of a chondrocyte sheet using cell sheet engineering. However, it remains unclear how such a thin cell sheet could repair a deep cartilage defect. We, therefore, focused on the mechanism of cartilage repair using cell sheet engineering in this study. Chondrocyte sheets and synovial cell sheets were fabricated using cell sheet engineering, and these allogenic cell sheets were transplanted to cover an osteochondral defect in a rat model. Macroscopic and histological evaluation was performed at 4 and 12 weeks after transplantation. Analysis of the gene expression of each cell sheet and of the regenerated tissue at 1 week after transplantation was performed. In addition, green fluorescent protein (GFP) transgenic rats were used as donors (transplanted chondrocyte sheets) or recipients (osteochondral defect models) to identify the cell origin of regenerated cartilage. Cartilage repair was significantly better in the group implanted with a chondrocyte sheet than in that with a synovial cell sheet. The results of gene expression analysis suggest that the possible factor contributing to cartilage repair might be TGFβ1. Cell tracking experiments using GFP transgenic rats showed that the regenerated cartilage was largely composed of cells derived from the transplanted chondrocyte sheets. PMID:25396711

Identification of Biomarkers for Footpad Dermatitis Development and Wound Healing

PubMed Central

Chen, Juxing; Tellez, Guillermo; Escobar, Jeffery

2016-01-01

Footpad dermatitis (FPD) is a type of skin inflammation that causes necrotic lesions on the plantar surface of the footpads in commercial poultry, with significant animal welfare, and economic implications. To identify biomarkers for FPD development and wound healing, a battery cage trial was conducted in which a paper sheet was put on the bottom of cages to hold feces to induce FPD of broilers. Day-of-hatch Ross 308 male broiler chicks were fed a corn–soybean meal diet and assigned to 3 treatments with 8 cages per treatment and 11 birds per cage. Cages without paper sheets were used as a negative control (NEG). Cages with paper sheets during the entire growth period (d 0–30) were used as a positive control (POS) to continually induce FPD. Cages with paper sheets during d 0–13 and without paper sheets during d 14–30 were used to examine the dynamic of FPD development and lesion wound healing (LWH). Footpad lesions were scored to grade (G) 1–5 with no lesion in G1 and most severe lesion in G5. Covering with paper sheets in POS and LWH induced 99% incidence of G3 footpads on d 13. Removing paper sheets from LWH healed footpad lesions by d 30. One representative bird, with lesions most close to pen average lesion score, was chosen to collect footpad skin samples for biomarker analysis. Total collagen protein and mRNA levels of tenascin X (TNX), type I α1 collagen (COL1A1), type III α1 collagen (COL3A1), tissue inhibitor of metalloproteinase 3 (TIMP3), and integrin α1 (ITGA1) mRNA levels were decreased (P < 0.05), while mRNA levels of tenascin C (TNC), tumor necrosis factor (TNF) α, Toll-like receptor (TLR) 4 and vascular endothelial growth factor (VEGF), IL-1β, and the ratio of MMP2 to all TIMP were increased (P < 0.03) in G3 footpads in POS and LWH compared to G1 footpads in NEG on d 14. These parameters continued to worsen with development of more severe lesions in POS. After paper sheets were removed (i.e., LWH), levels of these parameters gradually or rapidly returned to levels measured in NEG. Regression analysis indicated significant quadratic changes of these parameters to footpad lesion scores. In summary, these biomarkers were interrelated with dynamic changes of footpad lesion scores, suggesting they may be used as potential biomarkers for footpad lesion development and wound healing process. PMID:26973819

Method for heating a glass sheet

DOEpatents

Boaz, P.T.

1998-07-21

A method for heating a glass sheet includes the steps of heating a glass sheet to a first predetermined temperature and applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature to allow the glass sheet to be formed. 5 figs.

Method for heating and forming a glass sheet

DOEpatents

Boaz, Premakaran Tucker

1997-01-01

A method for heating and forming a glass sheet includes the steps of heating a glass sheet to at least a first predetermined temperature, applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature, cooling an outer surface of the glass sheet to at least a third predetermined temperature and forming the glass sheet using forming rollers to a predetermined configuration.

Wave-induced drift of large floating sheets

NASA Astrophysics Data System (ADS)

Christensen, K. H.; Weber, J. E.

In this article we study the wave-induced drift of large, flexible shallow floating objects, referred to as sheets. When surface waves propagate through a sheet, they provide a mean stress on the sheet, resulting in a mean drift. In response, the sheet generates an Ekman current. The drift velocity of the sheet is determined by (i) the wave-induced stress, (ii) the viscous stress due to the Ekman current, and (iii) the Coriolis force. The sheet velocity and the current beneath the sheet are determined for constant and depth-varying eddy viscosities.

FDTD modeling of thin impedance sheets

NASA Technical Reports Server (NTRS)

Luebbers, Raymond; Kunz, Karl

1991-01-01

Thin sheets of resistive or dielectric material are commonly encountered in radar cross section calculations. Analysis of such sheets is simplified by using sheet impedances. It is shown that sheet impedances can be modeled easily and accurately using Finite Difference Time Domain (FDTD) methods. These sheets are characterized by a discontinuity in the tangential magnetic field on either side of the sheet but no discontinuity in tangential electric field. This continuity, or single valued behavior of the electric field, allows the sheet current to be expressed in terms of an impedance multiplying this electric field.

Self-Pierce Riveting of Three Aluminium Alloy and Mild Steel Sheets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mori, K.; Abe, Y.; Sakai, S.

2010-06-15

Three aluminium alloy and steel sheets were joined with a self-piercing rivet. Self-pierce riveting has the function of joining steel and aluminium alloys having very different melting points due to plastic joining. The requisites for joining the three sheets are the driving of the rivet leg through the middle sheet, the flaring of the rivet leg in the lower sheet and the prevention of the fracture of the lower sheet. The joinability for various combinations of the three sheets was determined. When the rivet leg is small, no driving through the middle sheet occurs, the lower sheet ruptures for amore » large rivet leg. In addition, 980 MPa high strength steel, mild steel and aluminium alloy sheets were joined by the self-pierce riveting.« less

Method for heating and forming a glass sheet

DOEpatents

Boaz, P.T.

1997-08-12

A method for heating and forming a glass sheet includes the steps of heating a glass sheet to at least a first predetermined temperature, applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature, cooling an outer surface of the glass sheet to at least a third predetermined temperature and forming the glass sheet using forming rollers to a predetermined configuration. 5 figs.

Solar Energy Applications for Agriculture. A Curriculum Guide.

ERIC Educational Resources Information Center

Nebraska Univ., Lincoln. Dept. of Agricultural Education.

This curriculum guide contains five units for a course in solar energy applications for vocational agriculture. Each unit is organized in a format containing some or all of the following materials: unit objective, specific objectives, suggested instructor and student activities, list of instructional materials, assignment sheets, answers to…

Introduction to Natural Resources: Advanced Applications.

ERIC Educational Resources Information Center

Crummett, Dan

This guide, which is designed for use with student and teacher guides to a 10-unit secondary-level course in natural resources, contains a series of student supplements and advanced assignment and job sheets that provide students with additional opportunities to explore the following areas of natural resources and conservation education: outdoor…

Computer-Assisted Law Instruction: Clinical Education's Bionic Sibling

ERIC Educational Resources Information Center

Henn, Harry G.; Platt, Robert C.

1977-01-01

Computer-assisted instruction (CAI), like clinical education, has considerable potential for legal training. As an initial Cornell Law School experiment, a lesson in applying different corporate statutory dividend formulations, with a cross-section of balance sheets and other financial data, was used to supplement regular class assignments.…

Small Business Course for Older Americans. Student Handbook.

ERIC Educational Resources Information Center

American Association of Community and Junior Colleges, Washington, DC.

This student handbook was designed for a course which offers people aged 55 and older guidance in starting and operating a small business. Following introductory remarks concerning small businesses, information and assignment sheets related to each of the course's basic units are presented. Course units include the following: (1) Small Business…

Surgical Techniques. Second Edition. Teacher Edition.

ERIC Educational Resources Information Center

Bushey, Vicki; And Others

This instructor's manual contains 18 units of instruction for a course on surgical technology designed to include the entry-level competencies students need as a surgical technologist. Each unit includes some or all of the following basic components of a unit of instruction: objective sheet, suggested activities for the teacher, assignment sheets…

System for harvesting water wave energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhong Lin; Su, Yanjie; Zhu, Guang

A generator for harvesting energy from water in motion includes a sheet of a hydrophobic material, having a first side and an opposite second side, that is triboelectrically more negative than water. A first electrode sheet is disposed on the second side of the sheet of a hydrophobic material. A second electrode sheet is disposed on the second side of the sheet of a hydrophobic material and is spaced apart from the first electrode sheet. Movement of the water across the first side induces an electrical potential imbalance between the first electrode sheet and the second electrode sheet.

Investigation of the magnetic properties of Si-gradient steel sheet by comparison with 6.5%Si steel sheet

NASA Astrophysics Data System (ADS)

Hiratani, T.; Zaizen, Y.; Oda, Y.; Yoshizaki, S.; Senda, K.

2018-05-01

In this study, we investigated the magnetic properties of Si-gradient steel sheet produced by CVD (chemical vapor deposition) siliconizing process, comparing with 6.5% Si steel sheet. The Si-gradient steel sheet having silicon concentration gradient in the thickness direction, has larger hysteresis loss and smaller eddy current loss than the 6.5% Si steel sheet. In such a loss configuration, the iron loss of the Si-gradient steel sheet becomes lower than that of the 6.5% Si steel sheet at high frequencies. The experiment suggests that tensile stress is formed at the surface layer and compressive stress is formed at the inner layer in the Si gradient steel sheet. The magnetic anisotropy is induced by the internal stress and it is considered to affect the magnetization behavior of the Si-gradient steel sheet. The small eddy current loss of Si-gradient steel sheet can be explained as an effect of magnetic flux concentration on the surface layer.

46 CFR 160.060-1 - Incorporation by reference.

Code of Federal Regulations, 2010 CFR

2010-10-01

...-1: Sheet 1—Cutting Pattern and General Arrangement, Model AY. Sheet 2—Cutting Pattern and General Arrangement, Model CYM. Sheet 3—Cutting Pattern and General Arrangement, Model CYS. Sheet 4—Insert Pattern, Model AY. Sheet 5—Insert Pattern, Model CYM. Sheet 6—Insert Pattern, Model CYS. (c) Copies on file...

Fatigue Micromechanism Characterization in Carbon Fibre Reinforced Polymers Using Synchrotron Radiation Computed Tomography

DTIC Science & Technology

2014-12-18

Resources/DataSheets/ Prepreg -Data- Sheets/M21_global.pdf. [20] Hexcel HexPly 8552. http://www.hexcel.com/Resources/DataSheets/ Prepreg -Data- Sheets...8552_eu.pdf [21] 3501-6 Epoxy Matrix, Hexcel. http://www.hexcel.com/Resources/DataSheets/ Prepreg -Data- Sheets/3501-6_eu.pdf [22] B.A. Dowd, G.H

How might the North American ice sheet influence the northwestern Eurasian climate?

NASA Astrophysics Data System (ADS)

Beghin, P.; Charbit, S.; Dumas, C.; Kageyama, M.; Ritz, C.

2015-10-01

It is now widely acknowledged that past Northern Hemisphere ice sheets covering Canada and northern Europe at the Last Glacial Maximum (LGM) exerted a strong influence on climate by causing changes in atmospheric and oceanic circulations. In turn, these changes may have impacted the development of the ice sheets themselves through a combination of different feedback mechanisms. The present study is designed to investigate the potential impact of the North American ice sheet on the surface mass balance (SMB) of the Eurasian ice sheet driven by simulated changes in the past glacial atmospheric circulation. Using the LMDZ5 atmospheric circulation model, we carried out 12 experiments under constant LGM conditions for insolation, greenhouse gases and ocean. In these experiments, the Eurasian ice sheet is removed. The 12 experiments differ in the North American ice-sheet topography, ranging from a white and flat (present-day topography) ice sheet to a full-size LGM ice sheet. This experimental design allows the albedo and the topographic impacts of the North American ice sheet onto the climate to be disentangled. The results are compared to our baseline experiment where both the North American and the Eurasian ice sheets have been removed. In summer, the sole albedo effect of the American ice sheet modifies the pattern of planetary waves with respect to the no-ice-sheet case, resulting in a cooling of the northwestern Eurasian region. By contrast, the atmospheric circulation changes induced by the topography of the North American ice sheet lead to a strong decrease of this cooling. In winter, the Scandinavian and the Barents-Kara regions respond differently to the American ice-sheet albedo effect: in response to atmospheric circulation changes, Scandinavia becomes warmer and total precipitation is more abundant, whereas the Barents-Kara area becomes cooler with a decrease of convective processes, causing a decrease of total precipitation. The gradual increase of the altitude of the American ice sheet leads to less total precipitation and snowfall and to colder temperatures over both the Scandinavian and the Barents and Kara sea sectors. We then compute the resulting annual surface mass balance over the Fennoscandian region from the simulated temperature and precipitation fields used to force an ice-sheet model. It clearly appears that the SMB is dominated by the ablation signal. In response to the summer cooling induced by the American ice-sheet albedo, high positive SMB values are obtained over the Eurasian region, leading thus to the growth of an ice sheet. On the contrary, the gradual increase of the American ice-sheet altitude induces more ablation over the Eurasian sector, hence limiting the growth of Fennoscandia. To test the robustness of our results with respect to the Eurasian ice sheet state, we carried out two additional LMDZ experiments with new boundary conditions involving both the American (flat or full LGM) and high Eurasian ice sheets. The most striking result is that the Eurasian ice sheet is maintained under full-LGM North American ice-sheet conditions, but loses ~ 10 % of its mass compared to the case in which the North American ice sheet is flat. These new findings qualitatively confirm the conclusions from our first series of experiments and suggest that the development of the Eurasian ice sheet may have been slowed down by the growth of the American ice sheet, offering thereby a new understanding of the evolution of Northern Hemisphere ice sheets throughout glacial-interglacial cycles.

Geometry of thin liquid sheet flows

NASA Technical Reports Server (NTRS)

Chubb, Donald L.; Calfo, Frederick D.; Mcconley, Marc W.; Mcmaster, Matthew S.; Afjeh, Abdollah A.

1994-01-01

Incompresible, thin sheet flows have been of research interest for many years. Those studies were mainly concerned with the stability of the flow in a surrounding gas. Squire was the first to carry out a linear, invicid stability analysis of sheet flow in air and compare the results with experiment. Dombrowski and Fraser did an experimental study of the disintegration of sheet flows using several viscous liquids. They also detected the formulation of holes in their sheet flows. Hagerty and Shea carried out an inviscid stability analysis and calculated growth rates with experimental values. They compared their calculated growth rates with experimental values. Taylor studied extensively the stability of thin liquid sheets both theoretically and experimentally. He showed that thin sheets in a vacuum are stable. Brown experimentally investigated thin liquid sheet flows as a method of application of thin films. Clark and Dumbrowski carried out second-order stability analysis for invicid sheet flows. Lin introduced viscosity into the linear stability analysis of thin sheet flows in a vacuum. Mansour and Chigier conducted an experimental study of the breakup of a sheet flow surrounded by high-speed air. Lin et al. did a linear stability analysis that included viscosity and a surrounding gas. Rangel and Sirignano carried out both a linear and nonlinear invisid stability analysis that applies for any density ratio between the sheet liquid and the surrounding gas. Now there is renewed interest in sheet flows because of their possible application as low mass radiating surfaces. The objective of this study is to investigate the fluid dynamics of sheet flows that are of interest for a space radiator system. Analytical expressions that govern the sheet geometry are compared with experimental results. Since a space radiator will operate in a vacuum, the analysis does not include any drag force on the sheet flow.

Magma transport in sheet intrusions of the Alnö carbonatite complex, central Sweden.

PubMed

Andersson, Magnus; Almqvist, Bjarne S G; Burchardt, Steffi; Troll, Valentin R; Malehmir, Alireza; Snowball, Ian; Kübler, Lutz

2016-06-10

Magma transport through the Earth's crust occurs dominantly via sheet intrusions, such as dykes and cone-sheets, and is fundamental to crustal evolution, volcanic eruptions and geochemical element cycling. However, reliable methods to reconstruct flow direction in solidified sheet intrusions have proved elusive. Anisotropy of magnetic susceptibility (AMS) in magmatic sheets is often interpreted as primary magma flow, but magnetic fabrics can be modified by post-emplacement processes, making interpretation of AMS data ambiguous. Here we present AMS data from cone-sheets in the Alnö carbonatite complex, central Sweden. We discuss six scenarios of syn- and post-emplacement processes that can modify AMS fabrics and offer a conceptual framework for systematic interpretation of magma movements in sheet intrusions. The AMS fabrics in the Alnö cone-sheets are dominantly oblate with magnetic foliations parallel to sheet orientations. These fabrics may result from primary lateral flow or from sheet closure at the terminal stage of magma transport. As the cone-sheets are discontinuous along their strike direction, sheet closure is the most probable process to explain the observed AMS fabrics. We argue that these fabrics may be common to cone-sheets and an integrated geology, petrology and AMS approach can be used to distinguish them from primary flow fabrics.

Magma transport in sheet intrusions of the Alnö carbonatite complex, central Sweden

PubMed Central

Andersson, Magnus; Almqvist, Bjarne S. G.; Burchardt, Steffi; Troll, Valentin R.; Malehmir, Alireza; Snowball, Ian; Kübler, Lutz

2016-01-01

Magma transport through the Earth’s crust occurs dominantly via sheet intrusions, such as dykes and cone-sheets, and is fundamental to crustal evolution, volcanic eruptions and geochemical element cycling. However, reliable methods to reconstruct flow direction in solidified sheet intrusions have proved elusive. Anisotropy of magnetic susceptibility (AMS) in magmatic sheets is often interpreted as primary magma flow, but magnetic fabrics can be modified by post-emplacement processes, making interpretation of AMS data ambiguous. Here we present AMS data from cone-sheets in the Alnö carbonatite complex, central Sweden. We discuss six scenarios of syn- and post-emplacement processes that can modify AMS fabrics and offer a conceptual framework for systematic interpretation of magma movements in sheet intrusions. The AMS fabrics in the Alnö cone-sheets are dominantly oblate with magnetic foliations parallel to sheet orientations. These fabrics may result from primary lateral flow or from sheet closure at the terminal stage of magma transport. As the cone-sheets are discontinuous along their strike direction, sheet closure is the most probable process to explain the observed AMS fabrics. We argue that these fabrics may be common to cone-sheets and an integrated geology, petrology and AMS approach can be used to distinguish them from primary flow fabrics. PMID:27282420

A web-based fact sheet series for grandparents raising grandchildren and the professionals who serve them.

PubMed

Brintnall-Peterson, Mary; Poehlmann, Julie; Morgan, Kari; Shlafer, Rebecca

2009-04-01

To develop and evaluate a series of web-based fact sheets for grandparents raising grandchildren. The fact sheets focus on child development issues that grandparents may face when raising their grandchildren. The fact sheets were developed using research on attachment theory, child development, and the needs of grandparents raising grandchildren. The fact sheets can be viewed online or downloaded for free. Evaluation data for the fact sheets were gathered using an online survey. Results of the survey revealed that the fact sheets are used by grandparents and professionals. Respondents reported sharing the fact sheets with others and using them for personal use, in support groups, and as a general agency resource. The fact sheet series is a useful way to reach both grandparents and professionals working with this audience in a variety of settings. Modifications to the fact sheet series are suggested to address additional needs of grandparents raising grandchildren.

Solid oxide fuel cell with multi-unit construction and prismatic design

DOEpatents

McPheeters, Charles C.; Dees, Dennis W.; Myles, Kevin M.

1999-01-01

A single cell unit of a solid oxide fuel cell that is individually fabricated and sintered prior to being connected to adjacent cells to form a solid oxide fuel cell. The single cell unit is comprised of a shaped anode sheet positioned between a flat anode sheet and an anode-electrolyte-cathode (A/E/C) sheet, and a shaped cathode sheet positioned between the A/E/C sheet and a cathode-interconnect-anode (C/I/A) sheet. An alternate embodiment comprises a shaped cathode sheet positioned between an A/E/C sheet and a C/I/A sheet. The shaped sheets form channels for conducting reactant gases. Each single cell unit is individually sintered to form a finished sub-assembly. The finished sub-assemblies are connected in electrical series by interposing connective material between the end surfaces of adjacent cells, whereby individual cells may be inspected for defects and interchanged with non-defective single cell units.

Scaling results for the liquid sheet radiator

NASA Technical Reports Server (NTRS)

Chubb, Donald L.; Calfo, Frederick D.

1989-01-01

Surface tension forces at the edges of a thin liquid (approx 100 micrometers) sheet flow result in a triangularly shaped sheet. Such a geometry is ideal for an external flow radiator. The experimental investigation of such sheet flows was extended to large sheets (width = 23.5 cm, length = 3.5 m). Experimental L/W results are greater than the calculated results. However, more experimental results are necessary for a complete comparison. The calculated emissivity of a sheet of Dow-Corning 705 silicone oil, which is low temperature (300-400 K) candidate for a liquid sheet radiator (LSR), is greater than 0.8 for sheet thicknesses greater than 100 micrometers.

Field evaluation of ZeroFly--an insecticide incorporated plastic sheeting against malaria vectors & its impact on malaria transmission in tribal area of northern Orissa.

PubMed

Sharma, S K; Upadhyay, A K; Haque, M A; Tyagi, P K; Mohanty, S S; Mittal, P K; Dash, A P

2009-10-01

Insecticide incorporated plastic sheeting is a new technology to control mosquitoes in emergency shelter places and also temporary habitations in different locations. Therefore, field studies were conducted to assess the efficacy of ZeroFly plastic sheeting treated with deltamethrin on prevailing disease vectors Anopheles culicifacies and An. fluviatilis and its impact on malaria transmission in one of the highly endemic areas of Orissa. The study was conducted in Birkera block of Sundargarh district, Orissa state. The study area comprised 3 villages, which were randomized as ZeroFly plastic sheet, untreated plastic sheet and no sheet area. ZeroFly plastic sheets and untreated plastic sheets were fixed in study and control villages respectively covering all the rooms in each household. Longitudinal studies were conducted on the bioefficacy with the help of cone bioassays, monitoring of the mosquito density through hand catch, floor sheet and exit trap collections and fortnightly domiciliary active surveillance in all the study villages. In ZeroFly plastic sheeting area, there was a significant reduction of 84.7 per cent in the entry rate of total mosquitoes in comparison to pre-intervention phase. There was 56.2 per cent immediate mortality in total mosquitoes in houses with ZeroFly sheeting. The overall feeding success rate of mosquitoes in the trial village was only 12.5 per cent in comparison to 49.7 and 51.1 per cent in villages with untreated plastic sheet and no sheet respectively. There was a significant reduction of 65.0 and 70.5 per cent in malaria incidence in ZeroFly plastic sheeting area as compared to untreated plastic sheet and no sheet area respectively. Our study showed that introduction of ZeroFly plastic sheets in a community-based intervention programme is operationally feasible to contain malaria especially in the high transmission difficult areas.

Experimental investigation of a 1 kA/cm² sheet beam plasma cathode electron gun.

PubMed

Kumar, Niraj; Pal, Udit Narayan; Pal, Dharmendra Kumar; Prajesh, Rahul; Prakash, Ram

2015-01-01

In this paper, a cold cathode based sheet-beam plasma cathode electron gun is reported with achieved sheet-beam current density ∼1 kA/cm(2) from pseudospark based argon plasma for pulse length of ∼200 ns in a single shot experiment. For the qualitative assessment of the sheet-beam, an arrangement of three isolated metallic-sheets is proposed. The actual shape and size of the sheet-electron-beam are obtained through a non-conventional method by proposing a dielectric charging technique and scanning electron microscope based imaging. As distinct from the earlier developed sheet beam sources, the generated sheet-beam has been propagated more than 190 mm distance in a drift space region maintaining sheet structure without assistance of any external magnetic field.

The GLAS Standard Data Products Specification--Level 2, Version 9. Volume 14

NASA Technical Reports Server (NTRS)

Lee, Jeffrey E.

2013-01-01

The Geoscience Laser Altimeter System (GLAS) is the primary instrument for the ICESat (Ice, Cloud and Land Elevation Satellite) laser altimetry mission. ICESat was the benchmark Earth Observing System (EOS) mission for measuring ice sheet mass balance, cloud and aerosol heights, as well as land topography and vegetation characteristics. From 2003 to 2009, the ICESat mission provided multi-year elevation data needed to determine ice sheet mass balance as well as cloud property information, especially for stratospheric clouds common over polar areas. It also provided topography and vegetation data around the globe, in addition to the polar-specific coverage over the Greenland and Antarctic ice sheets.This document defines the Level-2 GLAS standard data products. This document addresses the data flow, interfaces, record and data formats associated with the GLAS Level 2 standard data products. The term standard data products refers to those EOS instrument data that are routinely generated for public distribution. The National Snow and Ice Data Center (NSDIC) distribute these products. Each data product has a unique Product Identification code assigned by the Senior Project Scientist. The Level 2 Standard Data Products specifically include those derived geophysical data values (i.e., ice sheet elevation, cloud height, vegetation height, etc.). Additionally, the appropriate correction elements used to transform the Level 1A and Level 1B Data Products into Level 2 Data Products are included. The data are packaged with time tags, precision orbit location coordinates, and data quality and usage flags.

A pilot study of simple interventions to improve informed consent in clinical research: feasibility, approach, and results.

PubMed

Kass, Nancy E; Taylor, Holly A; Ali, Joseph; Hallez, Kristina; Chaisson, Lelia

2015-02-01

Research suggests that participants do not always adequately understand studies. While some consent interventions increase understanding, methodologic challenges have been raised in studying consent outside of actual trial settings. This study examined the feasibility of testing two consent interventions in actual studies and measured effectiveness of interventions in improving understanding. Participants enrolling in any of eight ongoing clinical trials were sequentially assigned to one of three different informed consent strategies for enrollment in their clinical trial. Control participants received standard consent procedures for their trial. Participants in the first intervention arm received a bulleted fact sheet summarizing key study information. Participants in the second intervention arm received the bulleted fact sheet and also engaged in a feedback Q&A session. Later, patients answered closed- and open-ended questions to assess patient understanding and literacy. Descriptive statistics, Wilcoxon -Mann -Whitney and Kruskal-Wallis tests were generated to assess correlations; regression analysis determined predictors of understanding. 144 participants enrolled. Using regression analysis, participants receiving the second intervention scored 7.6 percentage points higher (p = .02) on open-ended questions about understanding than participants in the control, although unadjusted comparisons did not reach statistical significance. Our study supports the hypothesis that patients receiving both bulleted fact sheets and a Q&A session had higher understanding compared to standard consent. Fact sheets and short structured dialog are quick to administer and easy to replicate across studies and should be tested in larger samples. © The Author(s) 2014.

New directions in the science and technology of advanced sheet explosive formulations and the key energetic materials used in the processing of sheet explosives: Emerging trends.

PubMed

Talawar, M B; Jangid, S K; Nath, T; Sinha, R K; Asthana, S N

2015-12-30

This review presents the work carried out by the international community in the area of sheet explosive formulations and its applications in various systems. The sheet explosive is also named as PBXs and is a composite material in which solid explosive particles like RDX, HMX or PETN are dispersed in a polymeric matrix, forms a flexible material that can be rolled/cut into sheet form which can be applied to any complex contour. The designed sheet explosive must possess characteristic properties such as flexible, cuttable, water proof, easily initiable, and safe handling. The sheet explosives are being used for protecting tanks (ERA), light combat vehicle and futuristic infantry carrier vehicle from different attacking war heads etc. Besides, sheet explosives find wide applications in demolition of bridges, ships, cutting and metal cladding. This review also covers the aspects such as risks and hazard analysis during the processing of sheet explosive formulations, effect of ageing on sheet explosives, detection and analysis of sheet explosive ingredients and the R&D efforts of Indian researchers in the development of sheet explosive formulations. To the best of our knowledge, there has been no review article published in the literature in the area of sheet explosives. Copyright © 2015 Elsevier B.V. All rights reserved.

Magnetic Configurations of the Tilted Current Sheets and Dynamics of Their Flapping in Magnetotail

NASA Astrophysics Data System (ADS)

Shen, C.; Rong, Z. J.; Li, X.; Dunlop, M.; Liu, Z. X.; Malova, H. V.; Lucek, E.; Carr, C.

2009-04-01

Based on multiple spacecraft measurements, the geometrical structures of tilted current sheet and tail flapping waves have been analyzed and some features of the tilted current sheets have been made clear for the first time. The geometrical features of the tilted current sheet revealed in this investigation are as follows: (1) The magnetic field lines (MFLs) are generally plane curves and the osculating planes in which the MFLs lie are about vertical to the magnetic equatorial plane, while the tilted current sheet may lean severely to the dawn or dusk side. (2) The tilted current sheet may become very thin, its half thickness is generally much less than the minimum radius of the curvature of the MFLs. (3) In the neutral sheet, the field-aligned current density becomes very large and has a maximum value at the center of the current sheet. (4) In some cases, the current density is a bifurcated one, and the two humps of the current density often superpose two peaks in the gradient of magnetic strength, indicating that the magnetic gradient drift current is possibly responsible for the formation of the two humps of the current density in some tilted current sheets. Tilted current sheets often appear along with tail thick current sheet flapping waves. It is found that, in the tail flapping current sheets, the minimum curvature radius of the MFLs in the current sheet is rather large with values around 1RE, while the neutral sheet may be very thin, with its half thickness being several tenths ofRE. During the flapping waves, the current sheet is tilted substantially, and the maximum tilt angle is generally larger than 45

Emittance Measurements for a Thin Liquid Sheet Flow

NASA Technical Reports Server (NTRS)

Englehart, Amy N.; McConley, Marc W.; Chubb, Donald L.

1996-01-01

The Liquid Sheet Radiator (LSR) is an external flow radiator that uses a triangular-shaped flowing liquid sheet as the radiating surface. It has potentially much lower mass than solid wall radiators such as pumped loop and heat pipe radiators, along with being nearly immune to micrometeoroid penetration. The LSR has an added advantage of simplicity. Surface tension causes a thin (100-300 microns) liquid sheet to coalesce to a point, causing the sheet flow to have a triangular shape. Such a triangular sheet is desirable since it allows for simple collection of the flow at a single point. A major problem for all external flow radiators is the requirement that the working fluid be of very low (approx. 10(sup -8) torr) vapor pressure to keep evaporative losses low. As a result, working fluids are limited to certain oils (such as used in diffusion pumps) for low temperatures (300-400 K) and liquid metals for higher temperatures. Previous research on the LSR has been directed at understanding the fluid mechanics of thin sheet flows and assessing the stability of such flows, especially with regard to the formation of holes in the sheet. Taylor studied extensively the stability of thin liquid sheets both theoretically and experimentally. He showed that thin sheets in a vacuum are stable. The latest research has been directed at determining the emittance of thin sheet flows. The emittance was calculated from spectral transmittance data for the Dow Corning 705 silicone oil. By experimentally setting up a sheet flow, the emittance was also determined as a function of measurable quantities, most importantly, the temperature drop between the top of the sheet and the temperature at the coalescence point of the sheet. Temperature fluctuations upstream of the liquid sheet were a potential problem in the analysis and were investigated.

Scaling results for the Liquid Sheet Radiator (LSR)

NASA Technical Reports Server (NTRS)

Chubb, Donald L.; Calfo, Frederick D.

1989-01-01

Surface tension forces at the edges of a thin liquid (approx. 100 micrometers) sheet flow result in a triangularly shaped sheet. Such a geometry is ideal for an external flow radiator. The experimental investigation of such sheet flows was extended to large sheets (width = W = 23.5 cm, length = L approx. = 3.5 m). Experimental L/W results are greater than the calculated results. However, more experimental results are necessary for a complete comparison. The calculated emissivity of a sheet of Dow-Corning 705 silicone oil, which is a low temperature (300 to 400K) candidate for a liquid sheet radiator (LSR), is greater than .8 for sheet thicknesses greater than 100 micrometers.

Methods for Using Durable Adhesively Bonded Joints for Sandwich Structures

NASA Technical Reports Server (NTRS)

Smeltzer, Stanley S., III (Inventor); Lundgren, Eric C. (Inventor)

2016-01-01

Systems, methods, and apparatus for increasing durability of adhesively bonded joints in a sandwich structure. Such systems, methods, and apparatus includes an first face sheet and an second face sheet as well as an insert structure, the insert structure having a first insert face sheet, a second insert face sheet, and an insert core material. In addition, sandwich core material is arranged between the first face sheet and the second face sheet. A primary bondline may be coupled to the face sheet(s) and the splice. Further, systems, methods, and apparatus of the present disclosure advantageously reduce the load, provide a redundant path, reduce structural fatigue, and/or increase fatigue life.

Buckling and stretching of thin viscous sheets

NASA Astrophysics Data System (ADS)

O'Kiely, Doireann; Breward, Chris; Griffiths, Ian; Howell, Peter; Lange, Ulrich

2016-11-01

Thin glass sheets are used in smartphone, battery and semiconductor technology, and may be manufactured by producing a relatively thick glass slab and subsequently redrawing it to a required thickness. The resulting sheets commonly possess undesired centerline ripples and thick edges. We present a mathematical model in which a viscous sheet undergoes redraw in the direction of gravity, and show that, in a sufficiently strong gravitational field, buckling is driven by compression in a region near the bottom of the sheet, and limited by viscous resistance to stretching of the sheet. We use asymptotic analysis in the thin-sheet, low-Reynolds-number limit to determine the centerline profile and growth rate of such a viscous sheet.

Systems, Apparatuses, and Methods for Using Durable Adhesively Bonded Joints for Sandwich Structures

NASA Technical Reports Server (NTRS)

Smeltzer, III, Stanley S. (Inventor); Lundgren, Eric C. (Inventor)

2014-01-01

Systems, methods, and apparatus for increasing durability of adhesively bonded joints in a sandwich structure. Such systems, methods, and apparatus includes an first face sheet and an second face sheet as well as an insert structure, the insert structure having a first insert face sheet, a second insert face sheet, and an insert core material. In addition, sandwich core material is arranged between the first face sheet and the second face sheet. A primary bondline may be coupled to the face sheet(s) and the splice. Further, systems, methods, and apparatus of the present disclosure advantageously reduce the load, provide a redundant path, reduce structural fatigue, and/or increase fatigue life.

Experimental investigation of a 1 kA/cm{sup 2} sheet beam plasma cathode electron gun

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Niraj, E-mail: niraj.ceeri@gmail.com; Narayan Pal, Udit; Prajesh, Rahul

In this paper, a cold cathode based sheet-beam plasma cathode electron gun is reported with achieved sheet-beam current density ∼1 kA/cm{sup 2} from pseudospark based argon plasma for pulse length of ∼200 ns in a single shot experiment. For the qualitative assessment of the sheet-beam, an arrangement of three isolated metallic-sheets is proposed. The actual shape and size of the sheet-electron-beam are obtained through a non-conventional method by proposing a dielectric charging technique and scanning electron microscope based imaging. As distinct from the earlier developed sheet beam sources, the generated sheet-beam has been propagated more than 190 mm distance inmore » a drift space region maintaining sheet structure without assistance of any external magnetic field.« less

Observing the Heterogeneous Electro-redox of Individual Single-Layer Graphene Sheets.

PubMed

Chen, Tao; Zhang, Yuwei; Xu, Weilin

2016-09-27

Electro-redox-induced heterogeneous fluorescence of an individual single-layer graphene sheet was observed in real time by a total internal reflection fluorescence microscope. It was found that the fluorescence intensity of an individual sheet can be tuned reversibly by applying periodic voltages to control the redox degree of graphene sheets. Accordingly, the oxidation and reduction kinetics of an individual single-layer graphene sheet was studied at different voltages. The electro-redox-induced reversible variation of fluorescence intensity of individual sheets indicates a reversible band gap tuning strategy. Furthermore, correlation analysis of redox rate constants on individual graphene sheets revealed a redox-induced spatiotemporal heterogeneity or dynamics of graphene sheets. The observed controllable redox kinetics can rationally guide the precise band gap tuning of individual graphene sheets and then help their extensive applications in optoelectronics and devices for renewable energy.

Cell Sheet Stiffness Sensing without taking out from culture liquid.

PubMed

Uchida, Ryohei; Tanaka, Nobuyuki; Higashimori, Mitsuru; Tadakuma, Kenjiro; Kaneko, Makoto; Kondo, Makoto; Yamato, Masayuki

2010-01-01

Stiffness could be an important index for evaluating the vitality of cell sheet. This paper challenges the measurement of stiffness of transparent cell sheet in culture liquid without taking it out from petri dish. The system is composed of a micro air nozzle for supplying an air jet and a regular reflective type laser sensor for measuring the the deformation of transparent cell sheet. This system is called as Cell Sheet Stiffness Sensing system (CS(3) system). When an air jet is given to a cell sheet in culture liquid, it pushes away the liquid toward the outer direction at initial phase and reaches the surface of cell sheet. Without any switching motion, the air jet continuously imparts a force to the surface of cell sheet so that the sensor can measure the stiffness of the cell sheet.

FDTD modeling of thin impedance sheets

NASA Technical Reports Server (NTRS)

Luebbers, Raymond J.; Kunz, Karl S.

1991-01-01

Thin sheets of resistive or dielectric material are commonly encountered in radar cross section calculations. Analysis of such sheets is simplified by using sheet impedances. In this paper it is shown that sheet impedances can be modeled easily and accurately using Finite Difference Time Domain (FDTD) methods.

A novel gelatin hydrogel carrier sheet for corneal endothelial transplantation.

PubMed

Watanabe, Ryou; Hayashi, Ryuhei; Kimura, Yu; Tanaka, Yuji; Kageyama, Tomofumi; Hara, Susumu; Tabata, Yasuhiko; Nishida, Kohji

2011-09-01

We examined the feasibility of using gelatin hydrogels as carrier sheets for the transplantation of cultivated corneal endothelial cells. The mechanical properties, transparency, and permeability of gelatin hydrogel sheets were compared with those of atelocollagen sheets. Immunohistochemistry (ZO-1, Na(+)/K(+)-ATPase, and N-cadherin), hematoxylin and eosin staining, and scanning electron microscopy were performed to assess the integrity of corneal endothelial cells that were cultured on gelatin hydrogel sheets. The gelatin hydrogel sheets displayed greater transparency, elastic modulus, and albumin permeability compared to those of atelocollagen sheets. The corneal endothelial cells on gelatin hydrogel sheets showed normal expression levels of ZO-1, Na(+)/K(+)-ATPase, and N-cadherin. Hematoxylin and eosin staining revealed the formation of a continuous monolayer of cells attached to the gelatin hydrogel sheet. Scanning electron microscopy observations showed that the corneal endothelial cells were arranged in a regular, mosaic, and polygonal pattern with normal cilia. These results indicate that the gelatin hydrogel sheet is a promising material to transport corneal endothelial cells during transplantation.

Solid oxide fuel cell with multi-unit construction and prismatic design

DOEpatents

McPheeters, C.C.; Dees, D.W.; Myles, K.M.

1999-03-16

A single cell unit of a solid oxide fuel cell is described that is individually fabricated and sintered prior to being connected to adjacent cells to form a solid oxide fuel cell. The single cell unit is comprised of a shaped anode sheet positioned between a flat anode sheet and an anode-electrolyte-cathode (A/E/C) sheet, and a shaped cathode sheet positioned between the A/E/C sheet and a cathode-interconnect-anode (C/I/A) sheet. An alternate embodiment comprises a shaped cathode sheet positioned between an A/E/C sheet and a C/I/A sheet. The shaped sheets form channels for conducting reactant gases. Each single cell unit is individually sintered to form a finished sub-assembly. The finished sub-assemblies are connected in electrical series by interposing connective material between the end surfaces of adjacent cells, whereby individual cells may be inspected for defects and interchanged with non-defective single cell units. 7 figs.

A panel method study of vortex sheets with special emphasis on sheets of axisymmetric geometry. M.S. Thesis

NASA Technical Reports Server (NTRS)

Sugioka, I.; Widnall, S. E.

1985-01-01

The self induced evolution of a vortex sheet was simulated by modeling the sheet using an integration of discrete elements of vorticity. Replacing small sections of a vortex sheet by flat panels of constant vorticity is found to reproduce more accurately the initial conditions for the Lagrangian simulation technique than replacement by point vortices. The flat panel method for the vortex sheet was then extended to model axisymmetric vortex sheets. The local and far field velocities induced by the axisymmetric panels were obtained using matched asymptotic analysis, and some of the uncertainties involved in other models of the axisymmetric vortex sheet have been eliminated. One important result of this analysis is the determination of the proper choice of core size for a circular vortex filament which may replace a section of an axisymmetric vortex sheet. Roll-up of both two dimensional and axisymmetric vortex sheets was computed using the panel methods developed in the report.

Modeling the effect of doping on the catalyst-assisted growth and field emission properties of plasma-grown graphene sheet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, Neha; Sharma, Suresh C.; Sharma, Rinku

A theoretical model describing the effect of doping on the plasma-assisted catalytic growth of graphene sheet has been developed. The model accounts the charging rate of the graphene sheet, kinetics of all the plasma species, including the doping species, and the growth rate of graphene nuclei and graphene sheet due to surface diffusion, and accretion of ions on the catalyst nanoparticle. Using the model, it is observed that nitrogen and boron doping can strongly influence the growth and field emission properties of the graphene sheet. The results of the present investigation indicate that nitrogen doping results in reduced thickness andmore » shortened height of the graphene sheet; however, boron doping increases the thickness and height of the graphene sheet. The time evolutions of the charge on the graphene sheet and hydrocarbon number density for nitrogen and boron doped graphene sheet have also been examined. The field emission properties of the graphene sheet have been proposed on the basis of the results obtained. It is concluded that nitrogen doped graphene sheet exhibits better field emission characteristics as compared to undoped and boron doped graphene sheet. The results of the present investigation are consistent with the existing experimental observations.« less

Texture and mechanical properties of Al-0.5Mg-1.0Si-0.5Cu alloy sheets manufactured via a cross rolling method

NASA Astrophysics Data System (ADS)

Jeon, Jae-Yeol; Son, Hyeon-Taek; Woo, Kee-Do; Lee, Kwang-Jin

2012-04-01

The relationship between the texture and mechanical properties of 6xxx aluminum alloy sheets processed via cross rolling was investigated. The microstructures of the conventional rolled and cross rolled sheets after annealing were analyzed using optical micrographs (OM). The texture distribution across the thickness in the Al-Mg-Si-Cu alloy, conventional rolled sheets, and cross rolled sheets both before and after annealing was investigated via X-ray texture measurements. The texture was analyzed in three layers from the surface to the center of the sheet. The β-fiber texture of the conventional rolled sheet was typical of the texture obtained using aluminumoll ring. After annealing, the typical β-fiber orientations were changed to recrystallization textures: cube{001}<100> and normal direction (ND)-rotated cubes. However, the texture of the cross rolled sheet was composed of an asymmetrical, rolling direction (RD)-rotated cubes. After annealing, the asymmetrical orientations in the cross rolled sheet were changed to a randomized texture. The average R-value of the annealed cross rolled sheets was higher than that of the conventional rolled sheets. The limit dome height (LDH) test results demonstrated that cross rolling is effective in improving the formability of the Al-Mg-Si-Cu alloy sheets.

Nonlinear distortion of thin liquid sheets

NASA Astrophysics Data System (ADS)

Mehring, Carsten Ralf

Thin planar, annular and conical liquid sheets or films are analyzed, in a unified manner, by means of a reduced- dimension approach providing governing equations for the nonlinear motion of planar and swirling annular thin inviscid and incompressible liquid sheets in zero gravity and with axial disturbances only. Temporal analyses of periodically disturbed infinite sheets are considered, as well as spatial analyses of semi-infinite sheets modulated at the nozzle exit. Results on planar and swirling annular or conical sheets are presented for a zero density ambient gas. Here, conical sheets are obtained in the nearfield of the nozzle exit by considering sheets or films with swirl in excess of that needed to stabilize the discharging stream in its annular configuration. For nonswirling annular sheets a spatially and/or temporally constant gas-core pressure is assumed. A model extension considering the influence of aerodynamic effects on planar sheets is proposed. For planar and annular sheets, linear analyses of the pure initial- and pure boundary-value problem provide insight into the propagation characteristics of dilational and sinuous waves, the (linear) coupling between both wave modes, the stability limits for the annular configuration, as well as the appearance of particular waves on semi-infinite modulated sheets downstream from the nozzle exit. Nonlinear steady-state solutions for the conical configuration (without modulation) are illustrated. Comparison between nonlinear and linear numerical and linear analytical solutions for temporally or spatially developing sheets provides detailed information on the nonlinear distortion characteristics including nonlinear wave propagation and mode-coupling for all the considered geometric configurations and for a variety of parameter configurations. Sensitivity studies on the influence of Weber number, modulation frequency, annular radius, forcing amplitude and sheet divergence on breakup or collapse length and times are reported for modulated semi-infinite annular and conical sheets. Comparisons between the different geometric configurations are made. For periodically disturbed planar sheets, accuracy of the employed reduced-dimension approach is demonstrated by comparison with more accurate two-dimensional vortex dynamics simulations.

Measuring Discrimination in Education. NBER Working Paper No. 15057

ERIC Educational Resources Information Center

Hanna, Rema; Linden. Leigh

2009-01-01

In this paper, we illustrate a methodology to measure discrimination in educational contexts. In India, we ran an exam competition through which children compete for a large financial prize. We recruited teachers to grade the exams. We then randomly assigned child "characteristics" (age, gender, and caste) to the cover sheets of the…

The Effects of a Computerized Study Program on the Acquisition of Science Vocabulary

ERIC Educational Resources Information Center

Rollins, Karen F.

2012-01-01

The following study examined the difference in science vocabulary acquisition comparing computer-assisted learning and a traditional study review sheet. Fourth and fifth grade students from a suburban school in central Texas were randomly selected and randomly assigned to either experimental group or control group. Both groups were given a…

40 CFR 370.42 - What is Tier II inventory information?

Code of Federal Regulations, 2013 CFR

2013-07-01

... common name of the chemical as provided on the Material Safety Data Sheet and its Chemical Abstract....64(a). (2) Indicate whether the chemical is: pure or mixture; solid, liquid, or gas; and whether the... Inventory (TRI) and Risk Management Program. If your facility has not been assigned an identification number...

Exploring Norms and Moral Authority through Content Analysis of Classic Texts.

ERIC Educational Resources Information Center

Wallace, Richard Cheever

1993-01-01

Describes a class assignment for a college-level sociology course in which students read from religious texts to identify norms and sanctions. Reports that students expressed positive comments about the activity. Includes suggestions for preparing materials, instructions for implementing the activity, and a coding sheet to be used by students.…

Thermal analysis and vibrational spectroscopic characterization of the boro silicate mineral datolite - CaBSiO4(OH)

NASA Astrophysics Data System (ADS)

Frost, Ray L.; Xi, Yunfei; Scholz, Ricardo; Lima, Rosa Malena Fernandes; Horta, Laura Frota Campos; Lopez, Andres

2013-11-01

The objective of this work is to determine the thermal stability and vibrational spectra of datolite CaBSiO4(OH) and relate these properties to the structure of the mineral. The thermal analysis of datolite shows a mass loss of 5.83% over a 700-775 °C temperature range. This mass loss corresponds to 1 water (H2O) molecules pfu. A quantitative chemical analysis using electron probe was undertaken. The Raman spectrum of datolite is characterized by bands at 917 and 1077 cm-1 assigned to the symmetric stretching modes of BO and SiO tetrahedra. A very intense Raman band is observed at 3498 cm-1 assigned to the stretching vibration of the OH units in the structure of datolite. BOH out-of-plane vibrations are characterized by the infrared band at 782 cm-1. The vibrational spectra are based upon the structure of datolite based on sheets of four- and eight-membered rings of alternating SiO4 and BO3(OH) tetrahedra with the sheets bonded together by calcium atoms.

14 CFR Section 6 - Objective Classification of Balance Sheet Elements

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Objective Classification of Balance Sheet... AIR CARRIERS Balance Sheet Classifications Section 6 Objective Classification of Balance Sheet...) Record here all general and working funds available on demand as of the date of the balance sheet which...

14 CFR Section 6 - Objective Classification of Balance Sheet Elements

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Objective Classification of Balance Sheet... AIR CARRIERS Balance Sheet Classifications Section 6 Objective Classification of Balance Sheet...) Record here all general and working funds available on demand as of the date of the balance sheet which...

47 CFR 32.101 - Structure of the balance sheet accounts.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 2 2011-10-01 2011-10-01 false Structure of the balance sheet accounts. 32.101... UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.101 Structure of the balance sheet accounts. The Balance Sheet accounts shall be maintained as follows...

47 CFR 32.101 - Structure of the balance sheet accounts.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Structure of the balance sheet accounts. 32.101... UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.101 Structure of the balance sheet accounts. The Balance Sheet accounts shall be maintained as follows...

Transporter for Treated Sheet Materials

NASA Technical Reports Server (NTRS)

Pollack, M., H.

1983-01-01

Plastic spacers keep parts separated during transport or storage. Cart with rods and spacers holds sheets with delicate finishes for storage or transport. Sheets supported vertically by rods, or horizontally. Spacers keep sheets separated. Designed to eliminate time and expense of tapping, wrapping, and sometimes refinishing aluminum sheets with delicate anodized finished.

Highly Conductive Flexible Multi-Walled Carbon Nanotube Sheet Films for Transparent Touch Screen

NASA Astrophysics Data System (ADS)

Jung, Daewoong; Lee, Kyung Hwan; Kim, Donghyun; Burk, Dorothea; Overzet, Lawrence J.; Lee, Gil Sik

2013-03-01

Highly conductive and transparent thin films were prepared using highly purified multi-walled carbon nanotube (MWCNT) sheets. The electrical properties of the MWCNT sheet were remarkably improved by an acid treatment, resulting in densely packed MWCNTs. The morphology of the sheets reveals that continuous electrical pathways were formed by the acid treatment, greatly improving the sheet resistance all the while maintaining an excellent optical transmittance. These results encourage the use of these MWCNT sheets with low sheet resistance (450 Ω/sq) and high optical transmittance (90%) as a potential candidate for flexible display applications.

Stacked endoplasmic reticulum sheets are connected by helicoidal membrane motifs

PubMed Central

Terasaki, Mark; Shemesh, Tom; Kasthuri, Narayanan; Klemm, Robin W.; Schalek, Richard; Hayworth, Kenneth J.; Hand, Arthur R.; Yankova, Maya; Huber, Greg; Lichtman, Jeff W.; Rapoport, Tom A.; Kozlov, Michael M.

2013-01-01

The endoplasmic reticulum (ER) often forms stacked membrane sheets, an arrangement that is likely required to accommodate a maximum of membrane-bound polysomes for secretory protein synthesis. How sheets are stacked is unknown. Here, we used novel staining and automated ultra-thin sectioning electron microscopy methods to analyze stacked ER sheets in neuronal cells and secretory salivary gland cells of mice. Our results show that stacked ER sheets form a continuous membrane system in which the sheets are connected by twisted membrane surfaces with helical edges of left- or right-handedness. The three-dimensional structure of tightly stacked ER sheets resembles a parking garage, in which the different levels are connected by helicoidal ramps. A theoretical model explains the experimental observations and indicates that the structure corresponds to a minimum of elastic energy of sheet edges and surfaces. The structure allows the dense packing of ER sheets in the restricted space of a cell. PMID:23870120

Sheet, ligament and droplet formation in swirling primary atomization

NASA Astrophysics Data System (ADS)

Shao, Changxiao; Luo, Kun; Chai, Min; Fan, Jianren

2018-04-01

We report direct numerical simulations of swirling liquid atomization to understand the physical mechanism underlying the sheet breakup of a non-turbulent liquid swirling jet which lacks in-depth investigation. The volume-of-fluid (VOF) method coupled with adapted mesh refinement (AMR) technique in GERRIS code is employed in the present simulation. The mechanisms of sheet, ligament and droplet formation are investigated. It is observed that the olive-shape sheet structure is similar to the experimental result qualitatively. The numerical results show that surface tension, pressure difference and swirling effect contribute to the contraction and extension of liquid sheet. The ligament formation is partially at the sheet rim or attributed to the extension of liquid hole. Especially, the movement of hairpin vortex exerts by an anti-radial direction force to the sheet surface and leads to the sheet thinness. In addition, droplet formation is attributed to breakup of ligament and central sheet.

Method of fabricating metal- and ceramic- matrix composites and functionalized textiles

DOEpatents

Maxwell, James L [Jemez Springs, NM; Chavez, Craig A [Los Alamos, NM; Black, Marcie R [Lincoln, MA

2012-04-17

A method of manufacturing an article comprises providing a first sheet, wetting the first sheet with a liquid precursor to provide a first wet sheet, and irradiating the first wet sheet in a pattern corresponding to a first cross section of the article such that the liquid precursor is at least partially converted to a solid in the first cross section. A second sheet is disposed adjacent to the first sheet. The method further comprises wetting the second sheet with the liquid precursor to provide a second wet sheet, and irradiating the second wet sheet in a pattern corresponding to a second cross section of the article such that the liquid precursor is at least partially converted to a solid in the second cross section. In particular the liquid precursor may be converted to a metal, ceramic, semiconductor, semimetal, or a combination of these materials.

Dual circuit embossed sheet heat transfer panel

DOEpatents

Morgan, G.D.

1984-02-21

A heat transfer panel provides redundant cooling for fusion reactors or the like environment requiring low-mass construction. Redundant cooling is provided by two independent cooling circuits, each circuit consisting of a series of channels joined to inlet and outlet headers. The panel comprises a welded joinder of two full-size and two much smaller partial-size sheets. The first full-size sheet is embossed to form first portions of channels for the first and second circuits, as well as a header for the first circuit. The second full-sized sheet is then laid over and welded to the first full-size sheet. The first and second partial-size sheets are then overlaid on separate portions of the second full-sized sheet, and are welded thereto. The first and second partial-sized sheets are embossed to form inlet and outlet headers, which communicate with channels of the second circuit through apertures formed in the second full-sized sheet. 6 figs.

Dual-circuit embossed-sheet heat-transfer panel

DOEpatents

Morgan, G.D.

1982-08-23

A heat transfer panel provides redundant cooling for fusion reactors or the like environment requiring low-mass construction. Redundant cooling is provided by two independent cooling circuits, each circuit consisting of a series of channels joined to inlet and outlet headers. The panel comprises a welded joinder of two full-size and two much smaller partial-size sheets. The first full-size sheet is embossed for form first portions of channels for the first and second circuits, as well as a header for the first circuit. The second full-sized sheet is then laid over and welded to the first full-size sheet. The first and second partial-size sheets are then overlaid on separate portions of the second full-sized sheet, and are welded thereto. The first and second partial-sized sheets are embossed to form inlet and outlet headers, which communicate with channels of the second circuit through apertures formed in the second full-sized sheet.

Dual circuit embossed sheet heat transfer panel

DOEpatents

Morgan, Grover D.

1984-01-01

A heat transfer panel provides redundant cooling for fusion reactors or the like environment requiring low-mass construction. Redundant cooling is provided by two independent cooling circuits, each circuit consisting of a series of channels joined to inlet and outlet headers. The panel comprises a welded joinder of two full-size and two much smaller partial-size sheets. The first full-size sheet is embossed to form first portions of channels for the first and second circuits, as well as a header for the first circuit. The second full-sized sheet is then laid over and welded to the first full-size sheet. The first and second partial-size sheets are then overlaid on separate portions of the second full-sized sheet, and are welded thereto. The first and second partial-sized sheets are embossed to form inlet and outlet headers, which communicate with channels of the second circuit through apertures formed in the second full-sized sheet.

Sectional Finite Element Analysis on Viscous Pressure Forming of Sheet Metal

NASA Astrophysics Data System (ADS)

Liu, Jianguang; Wang, Zhongjin; Liu, Yan

2007-05-01

Viscous pressure forming (VPF) is a recently developed sheet flexible-die forming process, which uses a kind of semi-solid, flowable and viscous material as pressure-carrying medium that typically applied on one side of the sheet metal or on both sides of sheet metal. Different from traditional sheet metal forming processes in which sheet metal is the unique deformation-body, VPF is a coupling process of visco-elastoplastic bulk deformation of viscous medium and elasto-plastic deformation of sheet metal. A sectional finite element model for the coupled deformation between visco-elastoplastic body and elasto-plastic sheet metal was proposed to analyze VPF. The resolution of the Updated Lagrangian formulation is based on a static approach. By using static-explicit time integration strategy, the deformation of elasto-plastic sheet metal and visco-elastoplastic body can keep stable. The frictional contact between sheet metal and visco-elastoplastic body is treated by penalty function method. Using the proposed algorithm, sheet metal viscous pressure bulging (VPB) process is analyzed and compared with experiments. A good agreement between numerical simulation results and experimental ones proved the efficiency and stability of this algorithm.

Study of GO-Cu2O and RGO-Cu nanocomposite monolayer sheets prepared by modified Langmuir Blodgett route

NASA Astrophysics Data System (ADS)

Botcha, V. Divakar; Sutar, D. S.; Major, S. S.

2018-07-01

The modified Langmuir-Blodgett (MLB) technique has been improvised and extended to transfer GO-Cu2O nanocomposite monolayer sheets, by introducing Cu2+ ions into the subphase at room temperature. Morphological studies of as-transferred sheets revealed the presence of closely spaced GO monolayer sheets, with slightly enhanced roughness. XPS studies of as-transferred sheets confirmed the presence of copper, either as metallic Cu or Cu2O, along with significant Cu(OH)2 component, but TEM results confirmed the formation of Cu2O nanocrystallites of size (7 ± 2) nm, distributed uniformly over GO sheets. After heat treatment in vacuum at 400 °C, the nanocomposite sheets were covered with a uniform distribution of larger size nanoparticles. Based on Raman, XPS and TEM studies it has been confirmed that heat treatment at 400 °C in vacuum results in the formation of agglomerated Cu nanoparticles of size (23 ± 9) nm distributed uniformly over reduced graphene oxide (RGO) sheets. The electrical characterization of nanocomposite sheets on SiO2/Si in back-gated FET geometry revealed that the electrical conductivity of as-transferred GO-Cu2O sheets was similar to that usually observed for GO monolayer sheets. The RGO-Cu sheets also displayed electrical conductivity and field effect mobility values comparable to those reported for RGO sheets obtained by chemical/thermal reduction, and was unaffected by the presence of Cu nanoparticles.

Electromagnetic augmentation for casting of thin metal sheets

DOEpatents

Hull, John R.

1989-01-01

Thin metal sheets are cast by magnetically levitating molten metal deposited in a mold within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled by the water-cooled walls of the mold to form a solid metal sheet. A conducting shield is electrically coupled to the molten metal sheet to provide a return path for eddy currents induced in the metal sheet by the current in the AC conducting coils. In another embodiment, a DC conducting coil is coupled to the metal sheet for providing a direct current therein which interacts with the magnetic field to levitate the moving metal sheet. Levitation of the metal sheet in both molten and solid forms reduces its contact pressure with the mold walls while maintaining sufficient engagement therebetween to permit efficient conductive cooling by the mold through which a coolant fluid may be circulated. The magnetic fields associated with the currents in the aforementioned coils levitate the molten metal sheet while the mold provides for its lateral and vertical confinement. A leader sheet having electromagnetic characteristics similar to those of the molten metal sheet is used to start the casing process and precedes the molten metal sheet through the yoke/coil arrangement and mold and forms a continuous sheet therewith. The yoke/coil arrangement may be either U-shaped with a single racetrack coil or may be rectangular with a pair of spaced, facing bedstead coils.

Magnetic configurations of the tilted current sheets in magnetotail

NASA Astrophysics Data System (ADS)

Shen, C.; Rong, Z. J.; Li, X.; Dunlop, M.; Liu, Z. X.; Malova, H. V.; Lucek, E.; Carr, C.

2008-11-01

In this research, the geometrical structures of tilted current sheet and tail flapping waves have been analysed based on multiple spacecraft measurements and some features of the tilted current sheets have been made clear for the first time. The geometrical features of the tilted current sheet revealed in this investigation are as follows: (1) The magnetic field lines (MFLs) in the tilted current sheet are generally plane curves and the osculating planes in which the MFLs lie are about vertical to the equatorial plane, while the normal of the tilted current sheet leans severely to the dawn or dusk side. (2) The tilted current sheet may become very thin, the half thickness of its neutral sheet is generally much less than the minimum radius of the curvature of the MFLs. (3) In the neutral sheet, the field-aligned current density becomes very large and has a maximum value at the center of the current sheet. (4) In some cases, the current density is a bifurcated one, and the two humps of the current density often superpose two peaks in the gradient of magnetic strength, indicating that the magnetic gradient drift current is possibly responsible for the formation of the two humps of the current density in some tilted current sheets. Tilted current sheets often appear along with tail current sheet flapping waves. It is found that, in the tail flapping current sheets, the minimum curvature radius of the MFLs in the current sheet is rather large with values around 1 RE, while the neutral sheet may be very thin, with its half thickness being several tenths of RE. During the flapping waves, the current sheet is tilted substantially, and the maximum tilt angle is generally larger than 45°. The phase velocities of these flapping waves are several tens km/s, while their periods and wavelengths are several tens of minutes, and several earth radii, respectively. These tail flapping events generally last several hours and occur during quiet periods or periods of weak magnetospheric activity.

Comparison of efficacy of silicone gel, silicone gel sheeting, and topical onion extract including heparin and allantoin for the treatment of postburn hypertrophic scars.

PubMed

Karagoz, Huseyin; Yuksel, Fuat; Ulkur, Ersin; Evinc, Rahmi

2009-12-01

We compared the efficacy of silicone gel (Scarfade), silicone gel sheet (Epi-Derm), and topical onion extract including heparin and allantoin (Contractubex) for the treatment of hypertrophic scars. Forty-five postburn scars were included in the study. Patients with scars less than 6 months from injury were assigned at random to three groups each containing 15 scars, and their treatment was continued for 6 months. Scars were treated with Scarfade, Epiderm and Contractubex. Scar assessment was performed at the beginning of the treatment, and at the end of the sixth month when the treatment was completed by using the Vancouver scar scale. The difference between before and after treatment scores for each three groups was statistically significant. The difference between Scarfade group and Epi-Derm group was not significant; however, the differences of the other groups (Scarfade-Contractubex, Epiderm-Contractubex) were significant. Silicone products, either in gel or sheet, are superior to Contractubex in the treatment of the hypertrophic scar. The therapist should select the most appropriate agent according to the patient's need and guidelines of these signs.

Analysis of low-dose radiation shield effectiveness of multi-gate polymeric sheets

NASA Astrophysics Data System (ADS)

Kim, S. C.; Lee, H. K.; Cho, J. H.

2014-07-01

Computed tomography (CT) uses a high dose of radiation to create images of the body. As patients are exposed to radiation during a CT scan, the use of shielding materials becomes essential in CT scanning. This study was focused on the radiation shielding materials used for patients during a CT scan. In this study, sheets were manufactured to shield the eyes and the thyroid, the most sensitive parts of the body, against radiation exposure during a CT scan. These sheets are manufactured using silicone polymers, barium sulfate (BaSO4) and tungsten, with the aim of making these sheets equally or more effective in radiation shielding and more cost-effective than lead sheets. The use of barium sulfate drew more attention than tungsten due to its higher cost-effectiveness. The barium sulfate sheets were coated to form a multigate structure by applying the maximum charge rate during the agitator and subsequent mixing processes and creating multilayered structures on the surface. To measure radiation shielding effectiveness, the radiation dose was measured around both eyes and the thyroid gland using sheets in three different thicknesses (1, 2 and 3 mm). Among the 1 and 2 mm sheets, the Pb sheets exhibited greater effectiveness in radiation shielding around both eyes, but the W sheets were more effective in radiation shielding around the thyroid gland. In the 3 mm sheets, the Pb sheet also attenuated a higher amount of radiation around both eyes while the W sheet was more effective around the thyroid gland. In conclusion, the sheets made from barium sulfate and tungsten proved highly effective in shielding against low-dose radiation in CT scans without causing ill-health effects, unlike lead.

Ice stream activity scaled to ice sheet volume during Laurentide Ice Sheet deglaciation.

PubMed

Stokes, C R; Margold, M; Clark, C D; Tarasov, L

2016-02-18

The contribution of the Greenland and West Antarctic ice sheets to sea level has increased in recent decades, largely owing to the thinning and retreat of outlet glaciers and ice streams. This dynamic loss is a serious concern, with some modelling studies suggesting that the collapse of a major ice sheet could be imminent or potentially underway in West Antarctica, but others predicting a more limited response. A major problem is that observations used to initialize and calibrate models typically span only a few decades, and, at the ice-sheet scale, it is unclear how the entire drainage network of ice streams evolves over longer timescales. This represents one of the largest sources of uncertainty when predicting the contributions of ice sheets to sea-level rise. A key question is whether ice streams might increase and sustain rates of mass loss over centuries or millennia, beyond those expected for a given ocean-climate forcing. Here we reconstruct the activity of 117 ice streams that operated at various times during deglaciation of the Laurentide Ice Sheet (from about 22,000 to 7,000 years ago) and show that as they activated and deactivated in different locations, their overall number decreased, they occupied a progressively smaller percentage of the ice sheet perimeter and their total discharge decreased. The underlying geology and topography clearly influenced ice stream activity, but--at the ice-sheet scale--their drainage network adjusted and was linked to changes in ice sheet volume. It is unclear whether these findings can be directly translated to modern ice sheets. However, contrary to the view that sees ice streams as unstable entities that can accelerate ice-sheet deglaciation, we conclude that ice streams exerted progressively less influence on ice sheet mass balance during the retreat of the Laurentide Ice Sheet.

Effect of Cell Sheet Manipulation Techniques on the Expression of Collagen Type II and Stress Fiber Formation in Human Chondrocyte Sheets.

PubMed

Wongin, Sopita; Waikakul, Saranatra; Chotiyarnwong, Pojchong; Siriwatwechakul, Wanwipa; Viravaidya-Pasuwat, Kwanchanok

2018-03-01

Cell sheet technology is applied to human articular chondrocytes to construct a tissue-like structure as an alternative treatment for cartilage defect. The effect of a gelatin manipulator, as a cell sheet transfer system, on the quality of the chondrocyte sheets was investigated. The changes of important chondrogenic markers and stress fibers, resulting from the cell sheet manipulation, were also studied. The chondrocyte cell sheets were constructed with patient-derived chondrocytes using a temperature-responsive polymer and a gelatin manipulator as a transfer carrier. The properties of the cell sheets, including sizes, expression levels of collagen type II and I, and the localization of the stress fibers, were assessed and compared with those of the cell sheets harvested without the gelatin manipulator. Using the gelatin manipulator, the original size of the chondrocyte cell sheets was retained with abundant stress fibers, but with a decrease in the expression of collagen type II. Without the gelatin manipulator, although the cell shrinkage occurred, the cell sheet with suppressed stress fiber formation showed significantly higher levels of collagen type II. These results support our observations that stress fiber formation in chondrocyte cell sheets affected the production of chondrogenic markers. These densely packed tissue-like structures possessed a good chondrogenic activity, indicating their potential for use in autologous chondrocyte implantation to treat cartilage defects.

46 CFR 160.055-1 - Incorporation by reference.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... 160.055-IA: Sheet 1—Construction and Arrangement, Vinyl Dip Coated, Model 62, Adult. Sheet 2—Construction and Arrangement, Vinyl Dip Coated, Model 66, Child. Dwg. No. 160.055-IB: Sheet 1—Construction and Arrangement, Cloth Covered, Model 63, Adult. Sheet 2—Buoyant Inserts, Model 63. Sheet 3—Construction and...

Ice Sheet Model Intercomparison Project (ISMIP6) contribution to CMIP6

PubMed Central

Nowicki, Sophie M.J.; Payne, Tony; Larour, Eric; Seroussi, Helene; Goelzer, Heiko; Lipscomb, William; Gregory, Jonathan; Abe-Ouchi, Ayako; Shepherd, Andrew

2018-01-01

Reducing the uncertainty in the past, present and future contribution of ice sheets to sea-level change requires a coordinated effort between the climate and glaciology communities. The Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6) is the primary activity within the Coupled Model Intercomparison Project – phase 6 (CMIP6) focusing on the Greenland and Antarctic Ice Sheets. In this paper, we describe the framework for ISMIP6 and its relationship to other activities within CMIP6. The ISMIP6 experimental design relies on CMIP6 climate models and includes, for the first time within CMIP, coupled ice sheet – climate models as well as standalone ice sheet models. To facilitate analysis of the multi-model ensemble and to generate a set of standard climate inputs for standalone ice sheet models, ISMIP6 defines a protocol for all variables related to ice sheets. ISMIP6 will provide a basis for investigating the feedbacks, impacts, and sea-level changes associated with dynamic ice sheets and for quantifying the uncertainty in ice-sheet-sourced global sea-level change. PMID:29697697

Strain and mechanical properties of the VCM multilayer sheet and their composites using the digital speckle correlation method.

PubMed

Zhang, Dehai; Xie, Guizhong; Li, Yanqin; Liu, Jianxiu

2015-09-01

The digital speckle correlation method (DSCM) is introduced to solve the challenging problems in the related geometric measurement. Theoretical calculations of strain are deduced using the DSCM. Corresponding strains along x and y directions are obtained from uniaxial tension experiments and digital speckle measurements, using the VCM nondeep drawing multilayer sheet, the VCM deep-drawing multilayer sheet, clad films, nondeep drawing substrate, and deep-drawing substrate sheet as the targeted experimental objects. The results show that the maximum strains along the x direction of the VCM nondeep drawing multilayer sheet, the VCM deep-drawing multilayer sheet, clad film, nondeep drawing substrate, and deep-drawing substrate sheet are 68.473%, 48.632%, 91.632%, 50.784% and 40.068%, respectively, while the maximum strains along the y direction are -2.657%, -15.381%, 2.826%, -9.780% and -7.783%, respectively. The mechanical properties of the VCM multilayer sheet are between those of the substrate and clad film, while mechanical properties of the VCM deep-drawing multilayer sheet are superior to those of the VCM nondeep drawing multi-layer sheet.

Triple-glazed insulating unit with improved edge insulation

DOEpatents

Goodwin, George B.; Buchanan, Michael J.

2016-06-07

An insulating unit includes a first spacer frame between first and second sheets, e.g. glass sheets, and a second spacer frame between the second sheet and a third sheet. A first surface of the first spacer frame is adhered to inner surface of the first sheet, and an opposite second surface of the first spacer frame is adhered to a first surface of the second sheet, by a moisture impervious adhesive layer. A first outer surface of the second spacer frame is adhered to a second surface of the second sheet, and an opposite second outer surface of the second spacer frame is adhered to an inner surface of the third sheet, by the adhesive layer. The first spacer frame and the second spacer frame have an offset of greater than zero.

Lateral dimension-dependent antibacterial activity of graphene oxide sheets.

PubMed

Liu, Shaobin; Hu, Ming; Zeng, Tingying Helen; Wu, Ran; Jiang, Rongrong; Wei, Jun; Wang, Liang; Kong, Jing; Chen, Yuan

2012-08-21

Graphene oxide (GO) is a promising precursor to produce graphene-family nanomaterials for various applications. Their potential health and environmental impacts need a good understanding of their cellular interactions. Many factors may influence their biological interactions with cells, and the lateral dimension of GO sheets is one of the most relevant material properties. In this study, a model bacterium, Escherichia coli ( E. coli ), was used to evaluate the antibacterial activity of well-dispersed GO sheets, whose lateral size differs by more than 100 times. Our results show that the antibacterial activity of GO sheets toward E. coli cells is lateral size dependent. Larger GO sheets show stronger antibacterial activity than do smaller ones, and they have different time- and concentration-dependent antibacterial activities. Large GO sheets lead to most cell loss after 1 h incubation, and their concentration strongly influences antibacterial activity at relative low concentration (<10 μg/mL). In contrast, when incubating with small GO sheets up to 4 h, the inactivation rate of E. coli cells continues increasing. The increase of small GO sheet concentration also results in persistent increases in their antibacterial activity. In this study, GO sheets with different lateral sizes are all well dispersed, and their oxidation capacity toward glutathione is similar, consistent with X-ray photoelectron spectroscopy and ultraviolet-visible absorption spectroscopy results. This suggests the lateral size-dependent antibacterial activity of GO sheets is caused by neither their aggregation states, nor oxidation capacity. Atomic force microscope analysis of GO sheets and cells shows that GO sheets interact strongly with cells. Large GO sheets more easily cover cells, and cells cannot proliferate once fully covered, resulting in the cell viability loss observed in the followed colony counting test. In contrast, small GO sheets adhere to the bacterial surfaces, which cannot effectively isolate cells from environment. This study highlights the importance of tailoring the lateral dimension of GO sheets to optimize the application potential with minimal risks for environmental health and safety.

Twin-Mirrored-Galvanometer Laser-Light-Sheet Generator

NASA Technical Reports Server (NTRS)

Rhodes, David B.; Franke, John M.; Jones, Stephen B.; Leighty, Bradley D.

1991-01-01

Multiple, rotating laser-light sheets generated to illuminate flows in wind tunnels. Designed and developed to provide flexibility and adaptability to wide range of applications. Design includes capability to control size and location of laser-light sheet in real time, to generate horizontal or vertical sheets, to sweep sheet repeatedly through volume, to generate multiple sheets with controllable separation, and to rotate single or multiple laser-light sheets. Includes electronic equipment and laser mounted on adjustable-height platform. Twin-mirrored galvanometer unit supported by tripod to reduce vibration. Other possible applications include use in construction industry to align beams of building. Artistic or display applications also possible.

The use of platelet-rich fibrin combined with periodontal ligament and jaw bone mesenchymal stem cell sheets for periodontal tissue engineering.

PubMed

Wang, Zhong-Shan; Feng, Zhi-Hong; Wu, Guo-Feng; Bai, Shi-Zhu; Dong, Yan; Chen, Fa-Ming; Zhao, Yi-Min

2016-06-21

Periodontal regeneration involves the restoration of at least three unique tissues: cementum, periodontal ligament tissue (PDL) and alveolar bone tissue. Here, we first isolated human PDL stem cells (PDLSCs) and jaw bone mesenchymal stem cells (JBMSCs). These cells were then induced to form cell sheets using an ascorbic acid-rich approach, and the cell sheet properties, including morphology, thickness and gene expression profile, were compared. Platelet-rich fibrin (PRF) derived from human venous blood was then fabricated into bioabsorbable fibrin scaffolds containing various growth factors. Finally, the in vivo potential of a cell-material construct based on PDLSC sheets, PRF scaffolds and JBMSC sheets to form periodontal tissue was assessed in a nude mouse model. In this model, PDLSC sheet/PRF/JBMSC sheet composites were placed in a simulated periodontal space comprising human treated dentin matrix (TDM) and hydroxyapatite (HA)/tricalcium phosphate (TCP) frameworks. Eight weeks after implantation, the PDLSC sheets tended to develop into PDL-like tissues, while the JBMSC sheets tended to produce predominantly bone-like tissues. In addition, the PDLSC sheet/PRF/JBMSC sheet composites generated periodontal tissue-like structures containing PDL- and bone-like tissues. Further improvements in this cell transplantation design may have the potential to provide an effective approach for future periodontal tissue regeneration.

The Steady Flow Resistance of Perforated Sheet Materials in High Speed Grazing Flows

NASA Technical Reports Server (NTRS)

Syed, Asif A.; Yu, Jia; Kwan, H. W.; Chien, E.; Jones, Michael G. (Technical Monitor)

2002-01-01

A study was conducted to determine the effects of high speed grazing air flow on the acoustic resistance of perforated sheet materials used in the construction of acoustically absorptive liners placed in commercial aircraft engine nacelles. Since DC flow resistance of porous sheet materials is known to be a major component of the acoustic resistance of sound suppression liners, the DC flow resistance of a set of perforated face-sheets and linear 'wiremesh' face-sheets was measured in a flow duct apparatus (up to Mach 0.8). Samples were fabricated to cover typical variations in perforated face-sheet parameters, such as hole diameter, porosity and sheet thickness, as well as those due to different manufacturing processes. The DC flow resistance data from perforated sheets were found to correlate strongly with the grazing flow Mach number and the face-sheet porosity. The data also show correlation against the boundary layer displacement thickness to hole-diameter ratio. The increase in resistance with grazing flow for punched aluminum sheets is in good agreement with published results up to Mach 0.4, but is significantly larger than expected above Mach 0.4. Finally, the tests demonstrated that there is a significant increase in the resistance of linear 'wiremesh' type face-sheet materials.

Non-Evolutionarity of a Reconnecting Current Sheet as a Cause of Its Splitting into MHD Shocks

NASA Astrophysics Data System (ADS)

Markovsky, S. A.; Somov, B. V.

1995-04-01

Numerical simulations of the magnetic reconnection process in a current sheet show that, in some cases, MHD shocks appear to be attached to edges of the sheet. The appearance of the shocks may be considered to be a result of splitting of the sheet. In the present paper we suppose that this splitting takes place in consequence of non-evolutionarity of the reconnecting current sheet as a discontinuity. The problem of time evolution of small perturbations does not have a unique solution for a non-evolutionary discontinuity, and it splits into other (evolutionary) discontinuities. Such an approach allows us to determine conditions under which the splitting of the-sheet occurs. The main difficulty of this approach is that a current sheet is not reduced to a classified 1D discontinuity, because inhomogeneity of flow velocity inside the sheet is two-dimensional. To formulate the non-evolutionarity problem, we solve the linear MHD equations inside and outside the sheet and deduce linearized 1D boundary conditions at its surface. We show that for large enough conductivity, small perturbations exist which interact with the sheet as with a discontinuity. Then we obtain a non-evolutionarity criterion, with respect to these perturbations, in the form of a restriction on the flow velocity across the surface of the sheet.

Development and evaluation of adsorption sheet (HD safe sheet-U) using active carbon for the purpose of the preventing the contamination diffusion of urinary excreted anticancer drug.

PubMed

Sato, Junya; Ohkubo, Haruka; Sasaki, Yuki; Yokoi, Makoto; Hotta, Yasunori; Kudo, Kenzo

2017-01-01

Certain amount of anticancer drugs is excreted in the urine of patients receiving anticancer drugs, and urinary scattering including anticancer drugs at excretion has become a route of anticancer drug contamination. Therefore, we developed an active carbon sheet (HD safe sheet-U) that prevented diffusion by adsorbing anticancer drugs including that excreted in urine. The present study conducted a performance evaluation of this sheet. The adsorption performance of active carbon to anticancer drug in the urine was evaluated by determining concentration changes in the active carbon suspension (5 mg/mL) of 14 kinds of anticancer drugs (cyclophosphamide, ifosfamide, carboplatin, cisplatin, methotrexate, 5-fluorouracil, cytarabine, gemcitabine, doxorubicin, epirubicin, paclitaxel, docetaxel, etoposide, and irinotecan) diluted with artificial urine. Adhesion of the anticancer drug dropping on the sheet to a slipper sole was evaluated because urine including anticancer drugs is scattered on the floor, which can spread by adhering to shoe soles of patients and healthcare workers. The performance of the active carbon sheet was compared with two other types of medical adsorption sheets used as control sheets. Anticancer drugs diluted with artificial urine (1 mL) were dropped on the active carbon sheet and the two control sheets. The sheets were trod with slippers made by polyvinyl chloride. The adhered anticancer drug was wiped off and its quantity was determined. A remarkable decrease in anticancer drug concentrations, except for cisplatin, was detected by mixture of active carbon in the artificial urine (0-79.6%). The quantity of anticancer drug adhesion to slipper soles from the active carbon sheet was significantly lower compared with that observed for the two control sheets for eight kinds of anticancer drugs (cyclophosphamide, ifosfamide, carboplatin, methotrexate, cytarabine, gemcitabine, doxorubicin, and docetaxel). There was no adhesion in cyclophosphamide and docetaxel. Furthermore, the quantities of adhesion in cytarabine, gemcitabine, doxorubicin, paclitaxel, and irinotecan were lower than determination limit. Active carbon might be effective in adsorbing urinary anticancer drugs. The active carbon sheet adsorbed urinary excreted anticancer drugs, and use of such sheets might prevent diffusion of contamination due to urinary excreted anticancer drugs.

12 CFR 615.5212 - Credit conversion factors-off-balance sheet items.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Credit conversion factors-off-balance sheet... Credit conversion factors—off-balance sheet items. (a) The face amount of an off-balance sheet item is generally incorporated into risk-weighted assets in two steps. For most off-balance sheet items, the face...

12 CFR 615.5212 - Credit conversion factors-off-balance sheet items.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 6 2011-01-01 2011-01-01 false Credit conversion factors-off-balance sheet... Credit conversion factors—off-balance sheet items. (a) The face amount of an off-balance sheet item is generally incorporated into risk-weighted assets in two steps. For most off-balance sheet items, the face...

19 CFR 123.23 - Train sheet for in-transit rail shipments.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 19 Customs Duties 1 2011-04-01 2011-04-01 false Train sheet for in-transit rail shipments. 123.23 Section 123.23 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY... at the port of exit a train sheet, sometimes called a consist, bridge sheet or trip sheet, listing...

Machine Shop Suggested Job and Task Sheets. Part I. 25 Elementary Jobs.

ERIC Educational Resources Information Center

Texas A and M Univ., College Station. Vocational Instructional Services.

This volume consists of elementary job and task sheets adaptable for use in the regular vocational industrial education programs for the training of machinists and machine shop operators. Twenty-five simple machine shop job sheets are included. Some or all of this material is provided for each job sheet: an introductory sheet with aim, checking…

Fact Sheets from the ERIC Clearinghouse on Handicapped and Gifted Children, 1980.

ERIC Educational Resources Information Center

ERIC Clearinghouse on Handicapped and Gifted Children, Reston, VA.

The document is a compilation of 15 fact sheets developed during 1980 by the ERIC Clearinghouse on Handicapped and Gifted Children. Fact sheets are single sheets which provide basic information in a question-answer format and include additional resources and references. The fact sheets have the following titles: "Sex Education for Retarded…

Thin current sheets observation by MMS during a near-Earth's magnetotail reconnection event

NASA Astrophysics Data System (ADS)

Nakamura, R.; Varsani, A.; Nakamura, T.; Genestreti, K.; Plaschke, F.; Baumjohann, W.; Nagai, T.; Burch, J.; Cohen, I. J.; Ergun, R.; Fuselier, S. A.; Giles, B. L.; Le Contel, O.; Lindqvist, P. A.; Magnes, W.; Schwartz, S. J.; Strangeway, R. J.; Torbert, R. B.

2017-12-01

During summer 2017, the four spacecraft of the Magnetospheric Multiscale (MMS) mission traversed the nightside magnetotail current sheet at an apogee of 25 RE. They detected a number of flow reversal events suggestive of the passage of the reconnection current sheet. Due to the mission's unprecedented high-time resolution and spatial separation well below the ion scales, structure of thin current sheets is well resolved both with plasma and field measurements. In this study we examine the detailed structure of thin current sheets during a flow reversal event from tailward flow to Earthward flow, when MMS crossed the center of the current sheet . We investigate the changes in the structure of the thin current sheet relative to the X-point based on multi-point analysis. We determine the motion and strength of the current sheet from curlometer calculations comparing these with currents obtained from the particle data. The observed structures of these current sheets are also compared with simulations.

Stacked endoplasmic reticulum sheets are connected by helicoidal membrane motifs.

PubMed

Terasaki, Mark; Shemesh, Tom; Kasthuri, Narayanan; Klemm, Robin W; Schalek, Richard; Hayworth, Kenneth J; Hand, Arthur R; Yankova, Maya; Huber, Greg; Lichtman, Jeff W; Rapoport, Tom A; Kozlov, Michael M

2013-07-18

The endoplasmic reticulum (ER) often forms stacked membrane sheets, an arrangement that is likely required to accommodate a maximum of membrane-bound polysomes for secretory protein synthesis. How sheets are stacked is unknown. Here, we used improved staining and automated ultrathin sectioning electron microscopy methods to analyze stacked ER sheets in neuronal cells and secretory salivary gland cells of mice. Our results show that stacked ER sheets form a continuous membrane system in which the sheets are connected by twisted membrane surfaces with helical edges of left- or right-handedness. The three-dimensional structure of tightly stacked ER sheets resembles a parking garage, in which the different levels are connected by helicoidal ramps. A theoretical model explains the experimental observations and indicates that the structure corresponds to a minimum of elastic energy of sheet edges and surfaces. The structure allows the dense packing of ER sheets in the restricted space of a cell. Copyright © 2013 Elsevier Inc. All rights reserved.

Wrapping a liquid drop with a thin elastic sheet

NASA Astrophysics Data System (ADS)

Paulsen, Joseph; Démery, Vincent; Davidovitch, Benny; Santangelo, Chris; Russell, Thomas; Menon, Narayanan

2014-11-01

We study the wrapping of a liquid drop by an initially-planar ultrathin (~ 100 nm) circular sheet. These elastic sheets can completely relax compressive stresses by forming wrinkles. In the experiment, we find that when a small fraction of the drop is covered, the overall shape of the sheet (i.e. averaging over the wrinkles) is axisymmetric. As we shrink the drop further, the sheet develops radial folds that break the axisymmetry of the sheet and the drop. Our data are consistent with a model where the sheet selects the shape that minimizes the exposed liquid surface area. We thus identify a ``geometric wrapping'' regime, where the partially-wrapped shape depends only on the relative radii of the sheet and the drop; the global breaking of axisymmetry is independent of the elastic energy of the deformed sheet. This regime requires that bending energy is negligible compared to surface energy, in contrast to the ``capillary origami'' regime where the static shape of the drop comes from a balance of bending and capillary forces.

71. PALMDALE WATER COMPANY, EASTWOOD MULTIPLEARCHED DAM: STRESS SHEET, SHEET ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

71. PALMDALE WATER COMPANY, EASTWOOD MULTIPLE-ARCHED DAM: STRESS SHEET, SHEET 3; DECEMBER 20, 1918. Littlerock Water District files. - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

Thermomechanical processing of HAYNES alloy No. 188 sheet to improve creep strength

NASA Technical Reports Server (NTRS)

Klarstrom, D. L.

1978-01-01

Improvements in the low strain creep strength of HAYNES alloy No. 188 thin gauge sheet by means of thermomechanical processing were developed. Processing methods designed to develop a sheet with strong crystallographic texture after recrystallization and to optimize grain size were principally studied. The effects of thickness-to-grain diameter ratio and prestrain on low strain creep strength were also briefly examined. Results indicate that the most significant improvements were obtained in the sheets having a strong crystallographic texture. The low strain creep strength of the textured sheets was observed to be superior to that of standard production sheets in the 922 K to 1255 K temperature range. Tensile, stress rupture, fabricability, and surface stability properties of the experimental sheets were also measured and compared to property values reported for the baseline production sheets.

Determining Beta Sheet Crystallinity in Fibrous Proteins by Thermal Analysis and Infrared Spectroscopy

NASA Astrophysics Data System (ADS)

Hu, Xiao; Kaplan, David; Cebe, Peggy

2007-03-01

We report a study of self-assembled beta pleated sheets in Bombyx mori silk fibroin films using thermal analysis and infrared spectroscopy. Crystallization of beta pleated sheets was effected either by heating the films above the glass transition temperature (Tg) and holding isothermally, or by exposure to methanol. The fractions of secondary structural components including random coils, alpha helices, beta pleated sheets, turns, and side chains, were evaluated using Fourier self-deconvolution (FSD) of the infrared absorbance spectra. As crystalline beta sheets form, the heat capacity increment from the TMDSC trace at Tg is systematically decreased and is linearly well correlated with beta sheet content determined from FSD. This analysis of beta sheet content can serve as an alternative to X-ray methods and may have wide applicability to other crystalline beta sheet forming proteins.

Flat-plate solar array project. Volume 3: Silicon sheet: Wafers and ribbons

NASA Technical Reports Server (NTRS)

Briglio, A.; Dumas, K.; Leipold, M.; Morrison, A.

1986-01-01

The primary objective of the Silicon Sheet Task of the Flat-Plate Solar Array (FSA) Project was the development of one or more low cost technologies for producing silicon sheet suitable for processing into cost-competitive solar cells. Silicon sheet refers to high purity crystalline silicon of size and thickness for fabrication into solar cells. Areas covered in the project were ingot growth and casting, wafering, ribbon growth, and other sheet technologies. The task made and fostered significant improvements in silicon sheet including processing of both ingot and ribbon technologies. An additional important outcome was the vastly improved understanding of the characteristics associated with high quality sheet, and the control of the parameters required for higher efficiency solar cells. Although significant sheet cost reductions were made, the technology advancements required to meet the task cost goals were not achieved.

Microchannel laminated mass exchanger and method of making

DOEpatents

Martin, Peter M [Kennewick, WA; Bennett, Wendy D [Kennewick, WA; Matson, Dean W [Kennewick, WA; Stewart, Donald C [Richland, WA; Drost, Monte K [Pasco, WA; Wegeng, Robert S [Richland, WA; Perez, Joseph M [Richland, WA; Feng, Xiangdong [West Richland, WA; Liu, Jun [West Richland, WA

2003-03-18

The present invention is a microchannel mass exchanger having a first plurality of inner thin sheets and a second plurality of outer thin sheets. The inner thin sheets each have a solid margin around a circumference, the solid margin defining a slot through the inner thin sheet thickness. The outer thin sheets each have at least two header holes on opposite ends and when sandwiching an inner thin sheet. The outer thin sheets further have a mass exchange medium. The assembly forms a closed flow channel assembly wherein fluid enters through one of the header holes into the slot and exits through another of the header holes after contacting the mass exchange medium.

Microchannel laminated mass exchanger and method of making

DOEpatents

Martin, Peter M.; Bennett, Wendy D.; Matson, Dean W.; Stewart, Donald C.; Drost, Monte K.; Wegeng, Robert S.; Perez, Joseph M.; Feng, Xiangdong; Liu, Jun

2000-01-01

The present invention is a microchannel mass exchanger having a first plurality of inner thin sheets and a second plurality of outer thin sheets. The inner thin sheets each have a solid margin around a circumference, the solid margin defining a slot through the inner thin sheet thickness. The outer thin sheets each have at least two header holes on opposite ends and when sandwiching an inner thin sheet. The outer thin sheets further have a mass exchange medium. The assembly forms a closed flow channel assembly wherein fluid enters through one of the header holes into the slot and exits through another of the header holes after contacting the mass exchange medium.

Microchannel laminated mass exchanger and method of making

DOEpatents

Martin, Peter M [Kennewick, WA; Bennett, Wendy D [Kennewick, WA; Matson, Dean W [Kennewick, WA; Stewart, Donald C [Richland, WA; Drost, Monte K [Pasco, WA; Wegeng, Robert S [Richland, WA; Perez, Joseph M [Richland, WA; Feng, Xiangdong [West Richland, WA; Liu, Jun [West Richland, WA

2002-03-05

The present invention is a microchannel mass exchanger having a first plurality of inner thin sheets and a second plurality of outer thin sheets. The inner thin sheets each have a solid margin around a circumference, the solid margin defining a slot through the inner thin sheet thickness. The outer thin sheets each have at least two header holes on opposite ends and when sandwiching an inner thin sheet. The outer thin sheets further have a mass exchange medium. The assembly forms a closed flow channel assembly wherein fluid enters through one of the header holes into the slot and exits through another of the header holes after contacting the mass exchange medium.

Protein unfolding versus β-sheet separation in spider silk nanocrystals

NASA Astrophysics Data System (ADS)

Alam, Parvez

2014-03-01

In this communication a mechanism for spider silk strain hardening is proposed. Shear failure of β-sheet nanocrystals is the first failure mode that gives rise to the creation of smaller nanocrystals, which are of higher strength and stiffness. β-sheet unfolding requires more energy than nanocrystal separation in a shear mode of failure. As a result, unfolding occurs after the nanocrystals separate in shear. β-sheet unfolding yields a secondary strain hardening effect once the β-sheet conformation is geometrically stable and acts like a unidirectional fibre in a fibre reinforced composite. The mechanism suggested herein is based on molecular dynamics calculations of residual inter-β-sheet separation strengths against residual intra-β-sheet unfolding strengths.

Sheet production apparatus for removing a crystalline sheet from the surface of a melt using gas jets located above and below the crystalline sheet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kellerman, Peter L.; Thronson, Gregory D.

In one embodiment, a sheet production apparatus comprises a vessel configured to hold a melt of a material. A cooling plate is disposed proximate the melt and is configured to form a sheet of the material on the melt. A first gas jet is configured to direct a gas toward an edge of the vessel. A sheet of a material is translated horizontally on a surface of the melt and the sheet is removed from the melt. The first gas jet may be directed at the meniscus and may stabilize this meniscus or increase local pressure within the meniscus.

47 CFR 32.103 - Balance sheet accounts for other than regulated-fixed assets to be maintained.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 2 2011-10-01 2011-10-01 false Balance sheet accounts for other than regulated... for Balance Sheet Accounts § 32.103 Balance sheet accounts for other than regulated-fixed assets to be maintained. Balance sheet accounts to be maintained by Class A and Class B telephone companies for other than...

47 CFR 32.103 - Balance sheet accounts for other than regulated-fixed assets to be maintained.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Balance sheet accounts for other than regulated... for Balance Sheet Accounts § 32.103 Balance sheet accounts for other than regulated-fixed assets to be maintained. Balance sheet accounts to be maintained by Class A and Class B telephone companies for other than...

78 FR 14270 - Stainless Steel Sheet and Strip in Coils From Mexico: Notice of Settlement of NAFTA Proceedings

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-05

... DEPARTMENT OF COMMERCE International Trade Administration [A-201-822] Stainless Steel Sheet and... stainless steel sheet and strip in coils from Mexico (SSSS from Mexico). See Stainless Steel Sheet and Strip..., 2010, as a result of a sunset review. See Stainless Steel Sheet and Strip in Coils from Germany, Italy...

Predicting pulsar scintillation from refractive plasma sheets

NASA Astrophysics Data System (ADS)

Simard, Dana; Pen, Ue-Li

2018-07-01

The dynamic and secondary spectra of many pulsars show evidence for long-lived, aligned images of the pulsar that are stationary on a thin scattering sheet. One explanation for this phenomenon considers the effects of wave crests along sheets in the ionized interstellar medium, such as those due to Alfvén waves propagating along current sheets. If these sheets are closely aligned to our line of sight to the pulsar, high bending angles arise at the wave crests and a selection effect causes alignment of images produced at different crests, similar to grazing reflection off of a lake. Using geometric optics, we develop a simple parametrized model of these corrugated sheets that can be constrained with a single observation and that makes observable predictions for variations in the scintillation of the pulsar over time and frequency. This model reveals qualitative differences between lensing from overdense and underdense corrugated sheets: only if the sheet is overdense compared to the surrounding interstellar medium can the lensed images be brighter than the line-of-sight image to the pulsar, and the faint lensed images are closer to the pulsar at higher frequencies if the sheet is underdense, but at lower frequencies if the sheet is overdense.

Do You Prefer to Have the Text or a Sheet with Your Physics Exams?

NASA Astrophysics Data System (ADS)

Hamed, Kastro M.

2008-05-01

Many high school and introductory college physics instructors ponder the choice between "open text" exams versus "facts and formulae sheet" exams. Other alternatives are closed book/closed notes exams or an instructor-prepared sheet of facts and relevant formulas. There is no agreement on merit. Rehfuss strongly opposes allowing students to use formula sheets while taking physics exams despite acknowledging that such use is common practice. Cone2 responded to Rehfuss by defending the use of such sheets and outlining the benefits of a "cheat sheet." Debate over the use of a "cheat sheet" or other resources during exams is not limited to the physics community. Skidmore and Aagaard3 studied the relationship between testing conditions and student test scores for students in teacher education. Two decades earlier Boniface,4 Dorsal and Cundiff,5 and Hindman6 published papers on the use of texts and/or sheets during examinations in psychology and education. Others, such as Pullen et al.7 focused on studying the discarded cheat sheets themselves. Humorously, in October 2005 The New York Times8 reported an unusual museum exhibit of "cheat sheets" and the different ways students had cheated at a particular university.

A comparison of coronal and interplanetary current sheet inclinations

NASA Technical Reports Server (NTRS)

Behannon, K. W.; Burlaga, L. F.; Hundhausen, A. J.

1983-01-01

The HAO white light K-coronameter observations show that the inclination of the heliospheric current sheet at the base of the corona can be both large (nearly vertical with respect to the solar equator) or small during Cararington rotations 1660 - 1666 and even on a single solar rotation. Voyager 1 and 2 magnetic field observations of crossing of the heliospheric current sheet at distances from the Sun of 1.4 and 2.8 AU. Two cases are considered, one in which the corresponding coronameter data indicate a nearly vertical (north-south) current sheet and another in which a nearly horizontal, near equatorial current sheet is indicated. For the crossings of the vertical current sheet, a variance analysis based on hour averages of the magnetic field data gave a minimum variance direction consistent with a steep inclination. The horizontal current sheet was observed by Voyager as a region of mixed polarity and low speeds lasting several days, consistent with multiple crossings of a horizontal but irregular and fluctuating current sheet at 1.4 AU. However, variance analysis of individual current sheet crossings in this interval using 1.92 see averages did not give minimum variance directions consistent with a horizontal current sheet.

Predicting Pulsar Scintillation from Refractive Plasma Sheets

NASA Astrophysics Data System (ADS)

Simard, Dana; Pen, Ue-Li

2018-05-01

The dynamic and secondary spectra of many pulsars show evidence for long-lived, aligned images of the pulsar that are stationary on a thin scattering sheet. One explanation for this phenomenon considers the effects of wave crests along sheets in the ionized interstellar medium, such as those due to Alfvén waves propagating along current sheets. If these sheets are closely aligned to our line-of-sight to the pulsar, high bending angles arise at the wave crests and a selection effect causes alignment of images produced at different crests, similar to grazing reflection off of a lake. Using geometric optics, we develop a simple parameterized model of these corrugated sheets that can be constrained with a single observation and that makes observable predictions for variations in the scintillation of the pulsar over time and frequency. This model reveals qualitative differences between lensing from overdense and underdense corrugated sheets: Only if the sheet is overdense compared to the surrounding interstellar medium can the lensed images be brighter than the line-of-sight image to the pulsar, and the faint lensed images are closer to the pulsar at higher frequencies if the sheet is underdense, but at lower frequencies if the sheet is overdense.

Valuing Exercises for the Middle School. Resource Monograph No. 11.

ERIC Educational Resources Information Center

Casteel, J. Doyle; And Others

One of the major goals of the middle school is to help students gain and refine skills in the area of values clarification. One way of securing such value clarification is to plan and assign value sheets--carefully planned and written activities designed to elicit value clarification patterns of language usage from students. Six different formats…

Military Curriculum Materials for Vocational and Technical Education. Fundamentals of Electricity, 3-7.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus. National Center for Research in Vocational Education.

This self-paced correspondence course for independent study in electricity was adapted from military curriculum materials for use in vocational education. This basic course is designed to provide the student with some fundamentals of electricity--not with specific job skills. The seven lessons of the course each have a lesson assignment sheet with…

Supplying osteogenesis to dead bone using an osteogenic matrix cell sheet.

PubMed

Uchihara, Yoshinobu; Akahane, Manabu; Okuda, Akinori; Shimizu, Takamasa; Masuda, Keisuke; Kira, Tsutomu; Kawate, Kenji; Tanaka, Yasuhito

2018-02-22

To evaluate whether osteogenic matrix cell sheets can supply osteogenesis to dead bone. Femur bone fragments (5 mm in length) were obtained from Fisher 344 rats and irradiated by a single exposure of 60 Gy to produce bones that were no longer viable. Osteogenic matrix cell sheets were created from rat bone marrow-derived stromal cells (BMSCs). After wrapping the dead bone with an osteogenic matrix cell sheet, it was subcutaneously transplanted into the back of a rat and harvested after 4 weeks. Bone formation around the dead bone was evaluated by X-ray imaging and histology. Alkaline phosphatase (ALP) and osteocalcin (OC) mRNA expression levels were measured to confirm osteogenesis of the transplanted bone. The contribution of donor cells to bone formation was assessed using the Sry gene and PKH26. After the cell sheet was transplanted together with dead bone, X-ray images showed abundant calcification around the dead bone. In contrast, no newly formed bone was seen in samples that were transplanted without the cell sheet. Histological sections also showed newly formed bone around dead bone in samples transplanted with the cell sheet, whereas many empty lacunae and no newly formed bone were observed in samples transplanted without the cell sheet. ALP and OC mRNA expression levels were significantly higher in dead bones transplanted with cell sheets than in those without a cell sheet (P < 0.01). Sry gene expression and cells derived from cell sheets labeled with PKH26 were detected in samples transplanted with a cell sheet, indicating survival of donor cells after transplantation. Our study indicates that osteogenic matrix cell sheet transplantation can supply osteogenesis to dead bone. Copyright © 2018. Published by Elsevier B.V.

Diffuse light-sheet microscopy for stripe-free calcium imaging of neural populations.

PubMed

Taylor, Michael A; Vanwalleghem, Gilles C; Favre-Bulle, Itia A; Scott, Ethan K

2018-06-19

Light-sheet microscopy is used extensively in developmental biology and neuroscience. One limitation of this approach is that absorption and scattering produces shadows in the illuminating light sheet, resulting in stripe artifacts. Here, we introduce diffuse light-sheet microscopes that use a line diffuser to randomize the light propagation within the image plane, allowing the light sheets to reform after obstacles. We incorporate diffuse light sheets in two existing configurations: selective plane illumination microscopy (SPIM) in which the sample is illuminated with a static sheet of light, and digitally scanned light sheet (DSLS) in which a thin Gaussian beam is scanned across the image plane during each acquisition. We compare diffuse light-sheet microscopes to their conventional counterparts for calcium imaging of neural activity in larval zebrafish. We show that stripe artifacts can cast deep shadows that conceal some neurons, and that the stripes can flicker, producing spurious signals that could be interpreted as biological activity. Diffuse light sheets mitigate these problems, illuminating the blind spots produced by stripes and removing artifacts produced by the stripes' movements. The upgrade to diffuse light sheets is simple and inexpensive, especially in the case of DSLS, where it requires the addition of one optical element. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Development of a new surgical sheet containing both silk fibroin and thermoplastic polyurethane for cardiovascular surgery.

PubMed

Shimada, Ryo; Konishi, Hayato; Ozawa, Hideki; Katsumata, Takahiro; Tanaka, Ryou; Nakazawa, Yasumoto; Nemoto, Shintaro

2018-05-01

The surgical sheets that are currently used for congenital cardiovascular surgery have several drawbacks, including material deterioration, calcification, and pseudo-intimal proliferation resulting in hemodynamic disturbance. The aim of this study was to evaluate a newly developed sheet made from a combination of silk fibroin (SF) and a synthetic polymer, thermoplastic polyurethane (TPU), for surgical use. The hybrid SF/TPU sheet was a non-woven fabric with nanofibers that was made using the electrospinning method. The mechanical properties of the SF/TPU sheet were characterized. To determine its biocompatibility, part of the wall of the canine descending aorta was replaced with a SF/TPU sheet as a patch. The patches were removed after 3 months and a histological examination was performed. The flexibility, water permeability, and suture retention strength of the SF/TPU sheet were excellent and equivalent to those of existing sheets. The SF/TPU sheet had excellent handling properties and fit well into the vascular wall without needle hole bleeding. The histological examination revealed that the intimal tissue was restored well over the intraluminal surface of the explanted SF/TPU sheet, the absence of calcium deposition, and minimal inflammatory reaction, without signs of degradation. The SF/TPU sheet had excellent mechanical properties and tissue biocompatibility. These favorable features and possible biodegradability of the SF portion warrant a long-term follow-up study.

The use of platelet-rich fibrin combined with periodontal ligament and jaw bone mesenchymal stem cell sheets for periodontal tissue engineering

PubMed Central

Wang, Zhong-Shan; Feng, Zhi-Hong; Wu, Guo-Feng; Bai, Shi-Zhu; Dong, Yan; Chen, Fa-Ming; Zhao, Yi-Min

2016-01-01

Periodontal regeneration involves the restoration of at least three unique tissues: cementum, periodontal ligament tissue (PDL) and alveolar bone tissue. Here, we first isolated human PDL stem cells (PDLSCs) and jaw bone mesenchymal stem cells (JBMSCs). These cells were then induced to form cell sheets using an ascorbic acid-rich approach, and the cell sheet properties, including morphology, thickness and gene expression profile, were compared. Platelet-rich fibrin (PRF) derived from human venous blood was then fabricated into bioabsorbable fibrin scaffolds containing various growth factors. Finally, the in vivo potential of a cell-material construct based on PDLSC sheets, PRF scaffolds and JBMSC sheets to form periodontal tissue was assessed in a nude mouse model. In this model, PDLSC sheet/PRF/JBMSC sheet composites were placed in a simulated periodontal space comprising human treated dentin matrix (TDM) and hydroxyapatite (HA)/tricalcium phosphate (TCP) frameworks. Eight weeks after implantation, the PDLSC sheets tended to develop into PDL-like tissues, while the JBMSC sheets tended to produce predominantly bone-like tissues. In addition, the PDLSC sheet/PRF/JBMSC sheet composites generated periodontal tissue-like structures containing PDL- and bone-like tissues. Further improvements in this cell transplantation design may have the potential to provide an effective approach for future periodontal tissue regeneration. PMID:27324079

Keratinocyte cytoskeletal roles in cell sheet engineering

PubMed Central

2013-01-01

Background There is an increasing need to understand cell-cell interactions for cell and tissue engineering purposes, such as optimizing cell sheet constructs, as well as for examining adhesion defect diseases. For cell-sheet engineering, one major obstacle to sheet function is that cell sheets in suspension are fragile and, over time, will contract. While the role of the cytoskeleton in maintaining the structure and adhesion of cells cultured on a rigid substrate is well-characterized, a systematic examination of the role played by different components of the cytoskeleton in regulating cell sheet contraction and cohesion in the absence of a substrate has been lacking. Results In this study, keratinocytes were cultured until confluent and cell sheets were generated using dispase to remove the influence of the substrate. The effects of disrupting actin, microtubules or intermediate filaments on cell-cell interactions were assessed by measuring cell sheet cohesion and contraction. Keratin intermediate filament disruption caused comparable effects on cell sheet cohesion and contraction, when compared to actin or microtubule disruption. Interfering with actomyosin contraction demonstrated that interfering with cell contraction can also diminish cell cohesion. Conclusions All components of the cytoskeleton are involved in maintaining cell sheet cohesion and contraction, although not to the same extent. These findings demonstrate that substrate-free cell sheet biomechanical properties are dependent on the integrity of the cytoskeleton network. PMID:23442760

Characteristics of the aluminum alloy sheets for forming and application examples

NASA Astrophysics Data System (ADS)

Uema, Naoyuki; Asano, Mineo

2013-12-01

In this paper, the characteristics and application examples of aluminum alloy sheets developed for automotive parts by Sumitomo Light Metal are described. For the automotive closure panels (ex., hood, back-door), an Al-Mg-Si alloy sheet having an excellent hemming performance was developed. The cause of the occurrence and the propagation of cracks by bending were considered to be the combined effect of the shear bands formed across several crystal grains and the micro-voids formed around the second phase particles. By reducing the shear band formation during bending by controlling the crystallographic texture, the Al-Mg-Si alloy sheets showed an excellent hemming performance. For the automotive outer panels (ex., roof, fender, trunk-lid), an Al-Mg alloy sheet, which has both a good hot blow formability and excellent surface appearance after hot blow forming was developed, and hot blow forming technology was put to practical use using this developed Al-Mg alloy sheet. For automotive heat insulators, a high ductile Al-Fe alloy sheet was developed. The heat insulator, which integrated several panels, was put into practical use using this developed Al-Fe alloy sheet. The textured sheet was often used as a heat insulator in order to reduce the thickness of the aluminum alloy sheet and obtain good press formability. The new textured sheet, which has both high rigidity and good press formability for heat insulators, was developed by FE analysis.

5. Historic American Buildings Survey Taken from drawing sheet, SHEET ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. Historic American Buildings Survey Taken from drawing sheet, SHEET #21, Showing the house as restored since Survey. (Dormer windows omitted as not authentic) - Samuel des Marest House, River Road, New Milford, Bergen County, NJ

Validation of Modelled Ice Dynamics of the Greenland Ice Sheet using Historical Forcing

NASA Astrophysics Data System (ADS)

Hoffman, M. J.; Price, S. F.; Howat, I. M.; Bonin, J. A.; Chambers, D. P.; Tezaur, I.; Kennedy, J. H.; Lenaerts, J.; Lipscomb, W. H.; Neumann, T.; Nowicki, S.; Perego, M.; Saba, J. L.; Salinger, A.; Guerber, J. R.

2015-12-01

Although ice sheet models are used for sea level rise projections, the degree to which these models have been validated by observations is fairly limited, due in part to the limited duration of the satellite observation era and the long adjustment time scales of ice sheets. Here we describe a validation framework for the Greenland Ice Sheet applied to the Community Ice Sheet Model by forcing the model annually with flux anomalies at the major outlet glaciers (Enderlin et al., 2014, observed from Landsat/ASTER/Operation IceBridge) and surface mass balance (van Angelen et al., 2013, calculated from RACMO2) for the period 1991-2012. The ice sheet model output is compared to ice surface elevation observations from ICESat and ice sheet mass change observations from GRACE. Early results show promise for assessing the performance of different model configurations. Additionally, we explore the effect of ice sheet model resolution on validation skill.

Geohydrology of the glacial-outwash aquifer in the Baldwinsville area, Seneca River, Onondaga County, New York

USGS Publications Warehouse

Pagano, Timothy S.; Terry, David B.; Ingram, Arlynn W.

1986-01-01

Seven sheets of map data comprise this geohydrologic report. Sheet 1, surficial geology, illustrates the distribution of: open water areas; artificial fill; made land; urban land; alluvial silt and sand; alluvial sand and gravel; peat, marl, muck and clay; lake silt and/or clay; delta sand and gravel; beach sand and gravel; outwash sand and gravel; ice contact sand and ground; thick till cover bedrock; and thin till over bedrock over the Baldwinsville Area. Sheet 2, geologic sections, shows the layering of the aforementioned components below the surface layer. Sheet 3 illustrates the water infiltration of soil zone. Sheet 4 depicts the aquifer thickness. Sheet 5 illustrates the potentiometric surface, and Sheet 6 the well yield. Finally, Sheet 7 shows the land use in the region, specifically: industrial and extractive; commercial and services; transportation; farmland; forestland; residential; open public land; and water and wetlands. (Lantz-PTT)

Chest wall abscesses due to continuous application of silicone gel sheets for keloid management

PubMed Central

Tang, Hon-Lok; Lau, Keith K; Sam, Ramin; Ing, Todd S

2015-01-01

A patient with three episodes of chest wall abscesses as a result of 6 years of round-the-clock, uninterrupted (except during bathing) application of silicone gel sheets to a chest wall keloid is described. Two of the episodes occurred during hot weather. It is suggested that, in the space beneath the silicone sheet, the higher humidity and temperature, both generated as a result of prolonged sheeting, especially during hot weather, might have caused the keloid and its neighbouring skin to become soggy. This sogginess might have facilitated bacterial invasion. It is suggested that some sheeting-free time during a 24 h period might be indicated so that a keloid and its adjacent skin have the time to recover from their sheeting-induced sogginess. A sheeting-free period might especially be needed in the face of sweat accumulation beneath the silicone sheet. PMID:25920733

Chest wall abscesses due to continuous application of silicone gel sheets for keloid management.

PubMed

Tang, Hon-Lok; Lau, Keith K; Sam, Ramin; Ing, Todd S

2015-04-28

A patient with three episodes of chest wall abscesses as a result of 6 years of round-the-clock, uninterrupted (except during bathing) application of silicone gel sheets to a chest wall keloid is described. Two of the episodes occurred during hot weather. It is suggested that, in the space beneath the silicone sheet, the higher humidity and temperature, both generated as a result of prolonged sheeting, especially during hot weather, might have caused the keloid and its neighbouring skin to become soggy. This sogginess might have facilitated bacterial invasion. It is suggested that some sheeting-free time during a 24 h period might be indicated so that a keloid and its adjacent skin have the time to recover from their sheeting-induced sogginess. A sheeting-free period might especially be needed in the face of sweat accumulation beneath the silicone sheet. 2015 BMJ Publishing Group Ltd.

Electromagnetic augmentation for casting of thin metal sheets

DOEpatents

Hull, J.R.

1987-10-28

Thin metal sheets are cast by magnetically levitating molten metal deposited in a model within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled by the water-cooled walls of the mold to form a solid metal sheet. A conducting shield is electrically coupled to the molten metal sheet to provide a return path for eddy currents induced in the metal sheet by the current in the AC conducting coils. In another embodiment, a DC conducting coil is coupled to the metal sheet for providing a direct current therein which interacts with the magnetic field to levitate the moving metal sheet. Levitation of the metal sheet in both molten and solid forms reduces its contact pressure with the mold walls while maintaining sufficient engagement therebetween to permit efficient conductive cooling by the mold through which a coolant fluid may be circulated. 8 figs.

Experimental formability analysis of bondal sandwich sheet

NASA Astrophysics Data System (ADS)

Kami, Abdolvahed; Banabic, Dorel

2018-05-01

Metal/polymer/metal sandwich sheets have recently attracted the interests of industries like automotive industry. These sandwich sheets have superior properties over single-layer metallic sheets including good sound and vibration damping and light weight. However, the formability of these sandwich sheets should be enhanced which requires more research. In this paper, the formability of Bondal sheet (DC06/viscoelastic polymer/DC06 sandwich sheet) was studied through different types of experiments. The mechanical properties of Bondal were determined by uniaxial tensile tests. Hemispherical punch stretching and hydraulic bulge tests were carried out to determine the forming limit diagram (FLD) of Bondal. Furthermore, cylindrical and square cup drawing tests were performed in dry and oil lubricated conditions. These tests were conducted at different blank holding forces (BHFs). An interesting observation about Bondal sheet deep drawing was obtaining of higher drawing depths at dry condition in comparison with oil-lubricated condition.

Continuous development of current sheets near and away from magnetic nulls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Sanjay; Bhattacharyya, R.

2016-04-15

The presented computations compare the strength of current sheets which develop near and away from the magnetic nulls. To ensure the spontaneous generation of current sheets, the computations are performed congruently with Parker's magnetostatic theorem. The simulations evince current sheets near two dimensional and three dimensional magnetic nulls as well as away from them. An important finding of this work is in the demonstration of comparative scaling of peak current density with numerical resolution, for these different types of current sheets. The results document current sheets near two dimensional magnetic nulls to have larger strength while exhibiting a stronger scalingmore » than the current sheets close to three dimensional magnetic nulls or away from any magnetic null. The comparative scaling points to a scenario where the magnetic topology near a developing current sheet is important for energetics of the subsequent reconnection.« less

Multilayer radiation shield

DOEpatents

Urbahn, John Arthur; Laskaris, Evangelos Trifon

2009-06-16

A power generation system including: a generator including a rotor including a superconductive rotor coil coupled to a rotatable shaft; a first prime mover drivingly coupled to the rotatable shaft; and a thermal radiation shield, partially surrounding the rotor coil, including at least a first sheet and a second sheet spaced apart from the first sheet by centripetal force produced by the rotatable shaft. A thermal radiation shield for a generator including a rotor including a super-conductive rotor coil including: a first sheet having at least one surface formed from a low emissivity material; and at least one additional sheet having at least one surface formed from a low emissivity material spaced apart from the first sheet by centripetal force produced by the rotatable shaft, wherein each successive sheet is an incrementally greater circumferential arc length and wherein the centripetal force shapes the sheets into a substantially catenary shape.

Polycrystalline silicon sheets for solar cells by the spinning method

NASA Astrophysics Data System (ADS)

Maeda, Y.; Yokoyama, T.; Hide, I.

1984-03-01

A new method has been developed in which polycrystalline silicon sheets are formed directly from molten silicon on a spinning wheel. The sheet is 5 cm x 5 cm, 0.1-0.5 mm thick, and made at a rate of four sheets per 15 s; power conversion rate of a solar cell assembled with these silicon sheets is more than 10 percent.

Topical Application of a Silicone Gel Sheet with Verapamil Microparticles in a Rabbit Model of Hypertrophic Scar.

PubMed

Rha, Eun Young; Kim, Yun Ho; Kim, Tae-Jung; Yoo, Gyeol; Rhie, Jong Won; Kim, Hyun-Jung; Park, Il-Kyu

2016-01-01

The authors developed a novel treatment based on the topical application of a silicone gel sheet containing verapamil microparticles. The ability of these silicone gel sheets to inhibit hypertrophic scar in a rabbit ear wound model was examined. Ten New Zealand White rabbits with a total of 80 wounds in both ears were used in this study. The rabbits were divided into five groups (control; silicone gel sheet; and silicone gel sheet plus 0.25, 2.5, and 25 mg of verapamil per gram). Histopathologic findings were quantified. The mean scar elevation index, fibroblast counts, and capillary counts differed significantly among the five groups (p < 0.05). The median scar elevation index was significantly lower in the silicone gel sheet plus 2.5 mg of verapamil per gram group than in the silicone gel sheet group (1.2 versus 2.2). The median number of fibroblasts was significantly lower in the silicone gel sheet plus 0.25 mg of verapamil per gram group than in the silicone gel sheet group (172.5 versus 243). In the median number of capillary lumina, there was no significant difference between the silicone gel sheet group and the silicone gel sheet plus 0.25, 2.5, and 25 mg of verapamil per gram groups (28.5, 18, 20, and 18, respectively). Topical application of a silicone gel sheet with verapamil microparticles may be a novel, effective treatment method for hypertrophic scar, but its safety and efficacy in humans must be tested in clinical trials.

Micro-Scale Mechanical Testing of Non-Woven Carbon Nanotube Sheets and Yarns

NASA Technical Reports Server (NTRS)

Magargee, J.; Morestin, F.; Cao, J.; Jones, J. S.

2013-01-01

Non-woven carbon nanotube (CNT) sheets and yarns were tested using a novel micro-scale mechanical testing system. CNT sheets were observed to delaminate during uniaxial testing using an adbesive gripping method, resulting from a higher proportion of load bearing in the outer sheets versus internal sheets and an apparently low interlaminar shear strength. In response to this, a new spool-grip method was used to alleviate non-uniform through-thickness stresses, circumvent premature delamination, and allow the sheet material to sustain a 72% increase in measured tensile strength. Furthermore, tension tests of CNT yarns showed that the yarn-structure was approximaiely 7 times stronger than the sheet structure, owing to a higher degree of CNT alignment in the test direction.

Spiral wound extraction cartridge

DOEpatents

Wisted, Eric E.; Lundquist, Susan H.

1999-01-01

A cartridge device for removing an analyte from a fluid comprises a hollow core, a sheet composite comprising a particulate-loaded porous membrane and optionally at least one reinforcing spacer sheet, the particulate being capable of binding the analyte, the sheet composite being formed into a spiral configuration about the core, wherein the sheet composite is wound around itself and wherein the windings of sheet composite are of sufficient tightness so that adjacent layers are essentially free of spaces therebetween, two end caps which are disposed over the core and the lateral ends of the spirally wound sheet composite, and means for securing the end caps to the core, the end caps also being secured to the lateral ends of the spirally wound sheet composite. A method for removing an analyte from a fluid comprises the steps of providing a spirally wound element of the invention and passing the fluid containing the analyte through the element essentially normal to a surface of the sheet composite so as to bind the analyte to the particulate of the particulate-loaded porous membrane, the method optionally including the step of eluting the bound analyte from the sheet composite.

Durability improvements of two-dimensional metal nanoparticle sheets by molecular cross-linked structures between nanoparticles

NASA Astrophysics Data System (ADS)

Saito, Noboru; Ryuzaki, Sou; Wang, Pangpang; Park, Susie; Sakai, Nobuyuki; Tatsuma, Tetsu; Okamoto, Koichi; Tamada, Kaoru

2018-03-01

The durability of two-dimensional metal nanoparticle sheets is a crucial factor for realizing next-generation optoelectronic devices based on plasmonics such as organic light-emitting diodes. Here, we report improvements in the durability of Ag nanoparticle sheets by forming alkanedithiol (DT16) cross-linked structures between the nanoparticles. The cross-linked structures in a sheet were fabricated by the self-assembly of DT16-capped Ag nanoparticles with 10% coverage (AgDT16). The durabilities for thermal, organic solvent, and oxidation reactions of AgDT16 sheets were found to be improved owing to the cross-linked structures by comparing Ag nanoparticle sheets without the cross-linked structures. The absorbance spectra revealed that the Ag nanoparticle sheets without the structure are markedly damaged by each durability test, whereas the AgDT16 sheets remain. The molecular cross-linked structures between nanoparticles in two-dimansional metal nanoparticle sheets were found to have the potential to play a key role in the realization of plasmonic optoelectronic devices including metal nanoparticles.

Custom-shaping system for bone regeneration by seeding marrow stromal cells onto a web-like biodegradable hybrid sheet.

PubMed

Tsuchiya, Kohei; Mori, Taisuke; Chen, Guoping; Ushida, Takashi; Tateishi, Tetsuya; Matsuno, Takeo; Sakamoto, Michiie; Umezawa, Akihiro

2004-05-01

New bone for the repair or the restoration of the function of traumatized, damaged, or lost bone is a major clinical need, and bone tissue engineering has been heralded as an alternative strategy for regenerating bone. A novel web-like structured biodegradable hybrid sheet has been developed for bone tissue engineering by preparing knitted poly(DL-lactic-co-glycolic acid) sheets (PLGA sheets) with collagen microsponges in their openings. The PLGA skeleton facilitates the formation of the hybrid sheets into desired shapes, and the collagen microsponges in the pores of the PLGA sheet promote cell adhesion and uniform cell distribution throughout the sheet. A large number of osteoblasts established from marrow stroma adhere to the scaffolds and generate the desired-shaped bone in combination with these novel sheets. These results indicate that the web-like structured novel sheet shows promise for use as a tool for custom-shaped bone regeneration in basic research on osteogenesis and for the development of therapeutic applications. Copyright 2004 Springer-Verlag

Current state and future perspectives on coupled ice-sheet - sea-level modelling

NASA Astrophysics Data System (ADS)

de Boer, Bas; Stocchi, Paolo; Whitehouse, Pippa L.; van de Wal, Roderik S. W.

2017-08-01

The interaction between ice-sheet growth and retreat and sea-level change has been an established field of research for many years. However, recent advances in numerical modelling have shed new light on the precise interaction of marine ice sheets with the change in near-field sea level, and the related stability of the grounding line position. Studies using fully coupled ice-sheet - sea-level models have shown that accounting for gravitationally self-consistent sea-level change will act to slow down the retreat and advance of marine ice-sheet grounding lines. Moreover, by simultaneously solving the 'sea-level equation' and modelling ice-sheet flow, coupled models provide a global field of relative sea-level change that is consistent with dynamic changes in ice-sheet extent. In this paper we present an overview of recent advances, possible caveats, methodologies and challenges involved in coupled ice-sheet - sea-level modelling. We conclude by presenting a first-order comparison between a suite of relative sea-level data and output from a coupled ice-sheet - sea-level model.

The dynamics and shapes of a viscous sheet spreading on a moving liquid bath

NASA Astrophysics Data System (ADS)

Sebilleau, J.; Lebon, L.; Limat, L.; Quartier, L.; Receveur, M.

2010-10-01

We investigate the shape and dynamics of a floating viscous sheet formed by a jet falling on a static or moving bath under partial wetting conditions. For a static bath, the viscous sheet has a circular shape and spreads with a uniform thickness that is surprisingly larger than the static Langmuir equilibrium thickness. This thickening effect seems to be linked to a peculiarity of the oil used for the bath, which is in situation of total wetting on the sheet surface, and climbs the sheet a bit like a macroscopic "precursor film" that increases dissipation at the sheet perimeter. For a moving bath, the viscous sheet evolves from an ellipse to a ribbon, a transient remarkable pear shape being observed between these two states. A simple kinematic model of advection of the spreading sheet by the bath predicts very well the characteristics of the ribbon regime. Convected sheets whose shape is reminiscent of pendant drops in 2D are also observed at higher bath velocity, with interesting pinch off phenomena.

The Impact of Geothermal Heat on the Scandinavian Ice Sheet's LGM Extent

NASA Astrophysics Data System (ADS)

Szuman, Izabela; Ewertowski, Marek W.; Kalita, Jakub Z.

2016-04-01

The last Scandinavian ice sheet attained its most southern extent over Poland and Germany, protruding c. 200 km south of the main ice sheet mass. There are number of factors that may control ice sheet dynamics and extent. One of the less recognised is geothermal heat, which is heat that is supplied to the base of the ice sheet. A heat at the ice/bed interface plays a crucial role in controlling ice sheet stability, as well as impacting basal temperatures, melting, and ice flow velocities. However, the influence of geothermal heat is still virtually neglected in reconstructions and modelling of paleo-ice sheets behaviour. Only in a few papers is geothermal heat recalled though often in the context of past climatic conditions. Thus, the major question is if and how spatial differences in geothermal heat had influenced paleo-ice sheet dynamics and in consequence their extent. Here, we assumed that the configuration of the ice sheet along its southern margin was moderately to strongly correlated with geothermal heat for Poland and non or negatively correlated for Germany.

On the balance of stresses in the plasma sheet.

NASA Technical Reports Server (NTRS)

Rich, F. J.; Wolf, R. A.; Vasyliunas, V. M.

1972-01-01

The stress resulting from magnetic tension on the neutral sheet must, in a steady state, be balanced by any one or a combination of (1) a pressure gradient in the direction along the axis of the tail, (2) a similar gradient of plasma flow kinetic energy, and (3) the tension resulting from a pressure anisotropy within the plasma sheet. Stress balance in the first two cases requires that the ratios h/LX and BZ/BX be of the same order of magnitude, where h is the half-thickness of the neutral sheet, LX is the length scale for variations along the axis of the tail, and BZ and BX are the magnetic field components in the plasma sheet just outside the neutral sheet. The second case requires, in addition, that the plasma flow speed within the neutral sheet be of the order of or larger than the Alfven speed outside the neutral sheet. Stress balance in the third case requires that just outside the neutral sheet the plasma pressure obey the marginal firehose stability condition.

ISMIP6 - initMIP: Greenland ice sheet model initialisation experiments

NASA Astrophysics Data System (ADS)

Goelzer, Heiko; Nowicki, Sophie; Payne, Tony; Larour, Eric; Abe Ouchi, Ayako; Gregory, Jonathan; Lipscomb, William; Seroussi, Helene; Shepherd, Andrew; Edwards, Tamsin

2016-04-01

Earlier large-scale Greenland ice sheet sea-level projections e.g. those run during ice2sea and SeaRISE initiatives have shown that ice sheet initialisation can have a large effect on the projections and gives rise to important uncertainties. This intercomparison exercise (initMIP) aims at comparing, evaluating and improving the initialization techniques used in the ice sheet modeling community and to estimate the associated uncertainties. It is the first in a series of ice sheet model intercomparison activities within ISMIP6 (Ice Sheet Model Intercomparison Project for CMIP6). The experiments are conceived for the large-scale Greenland ice sheet and are designed to allow intercomparison between participating models of 1) the initial present-day state of the ice sheet and 2) the response in two schematic forward experiments. The latter experiments serve to evaluate the initialisation in terms of model drift (forward run without any forcing) and response to a large perturbation (prescribed surface mass balance anomaly). We present and discuss first results of the intercomparison and highlight important uncertainties with respect to projections of the Greenland ice sheet sea-level contribution.

Ice Sheet Model Intercomparison Project (ISMIP6) Contribution to CMIP6

NASA Technical Reports Server (NTRS)

Nowicki, Sophie M. J.; Payne, Tony; Larour, Eric; Seroussi, Helene; Goelzer, Heiko; Lipscomb, William; Gregory, Jonathan; Abe-Ouchi, Ayako; Shepherd, Andrew

2016-01-01

Reducing the uncertainty in the past, present, and future contribution of ice sheets to sea-level change requires a coordinated effort between the climate and glaciology communities. The Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6) is the primary activity within the Coupled Model Intercomparison Project phase 6 (CMIP6) focusing on the Greenland and Antarctic ice sheets. In this paper, we describe the framework for ISMIP6 and its relationship with other activities within CMIP6. The ISMIP6 experimental design relies on CMIP6 climate models and includes, for the first time within CMIP, coupled ice-sheetclimate models as well as standalone ice-sheet models. To facilitate analysis of the multi-model ensemble and to generate a set of standard climate inputs for standalone ice-sheet models, ISMIP6 defines a protocol for all variables related to ice sheets. ISMIP6 will provide a basis for investigating the feedbacks, impacts, and sea-level changes associated with dynamic ice sheets and for quantifying the uncertainty in ice-sheet-sourced global sea-level change.

Theoretical and experimental emittance measurements for a thin liquid sheet flow

NASA Technical Reports Server (NTRS)

Englehart, Amy N.; Mcconley, Marc W.; Chubb, Donald L.

1995-01-01

Surface tension forces at the edges of a thin liquid (approximately 200 microns) sheet flow result in a triangularly shaped sheet. Such a geometry is ideal for an external flow radiator. Since the fluid must have very low vapor pressure, Dow Corning 705 silicone oil was used and the emittance of a flowing sheet of oil was determined by two methods. The emittance was derived as a function of the temperature drop between the top of the sheet and the coalescence point of the sheet, the sink temperature, the volumetric flow and the length of the sheet. the emittance for the oil was also calculated using an extinction coefficient determined from spectral transmittance data of the oil. The oil's emittance ranges from .67 to .87 depending on the sheet thickness and sheet temperature. The emittance derived from the temperature drop was slightly less than the emittance calculated from transmittance data. An investigation of temperature fluctuation upstream of the slit plate was also done. The fluctuations were determined to be negligible, not affecting the temperature drop which was due to radiation.

NMR analysis of cross strand aromatic interactions in an 8 residue hairpin and a 14 residue three stranded β-sheet peptide.

PubMed

Sonti, Rajesh; Rai, Rajkishor; Ragothama, Srinivasarao; Balaram, Padmanabhan

2012-12-13

Cross strand aromatic interactions between a facing pair of phenylalanine residues in antiparallel β-sheet structures have been probed using two structurally defined model peptides. The octapeptide Boc-LFV(D)P(L)PLFV-OMe (peptide 1) favors the β-hairpin conformation nucleated by the type II' β-turn formed by the (D)Pro-(L)Pro segment, placing Phe2 and Phe7 side chains in proximity. Two centrally positioned (D)Pro-(L)Pro segments facilitate the three stranded β-sheet formation in the 14 residue peptide Boc-LFV(D)P(L)PLFVA(D)P(L)PLFV-OMe (peptide 2) in which the Phe2/Phe7 orientations are similar to that in the octapeptide. The anticipated folded conformations of peptides 1 and 2 are established by the delineation of intramolecularly hydrogen bonded NH groups and by the observation of specific cross strand NOEs. The observation of ring current shifted aromatic protons is a diagnostic of close approach of the Phe2 and Phe7 side chains. Specific assignment of aromatic proton resonances using HSQC and HSQC-TOCSY methods allow an analysis of interproton NOEs between the spatially proximate aromatic rings. This approach facilitates specific assignments in systems containing multiple aromatic rings in spectra at natural abundance. Evidence is presented for a dynamic process which invokes a correlated conformational change about the C(α)-C(β)(χ(1)) bond for the pair of interacting Phe residues. NMR results suggest that aromatic ring orientations observed in crystals are maintained in solution. Anomalous temperature dependence of ring current induced proton chemical shifts suggests that solvophobic effects may facilitate aromatic ring clustering in apolar solvents.

Ohm's law for a current sheet

NASA Technical Reports Server (NTRS)

Lyons, L. R.; Speiser, T. W.

1985-01-01

The paper derives an Ohm's law for single-particle motion in a current sheet, where the magnetic field reverses in direction across the sheet. The result is considerably different from the resistive Ohm's law often used in MHD studies of the geomagnetic tail. Single-particle analysis is extended to obtain a self-consistency relation for a current sheet which agrees with previous results. The results are applicable to the concept of reconnection in that the electric field parallel to the current is obtained for a one-dimensional current sheet with constant normal magnetic field. Dissipated energy goes directly into accelerating particles within the current sheet.

Tensile property improvement of TWIP-cored three-layer steel sheets fabricated by hot-roll-bonding with low-carbon steel or interstitial-free steel

PubMed Central

Park, Jaeyeong; Kim, Jung-Su; Kang, Minju; Sohn, Seok Su; Cho, Won Tae; Kim, Hyoung Seop; Lee, Sunghak

2017-01-01

TWIP-cored three-layer steel sheets were newly fabricated by hot rolling of TWIP steel sheet surrounded by low-carbon (LC) or interstitial-free (IF) steel sheets. TWIP/LC or TWIP/IF interfaces were well bonded without pores or voids, while a few pearlites were thinly formed along the interfaces. The strengths and elongation of the TWIP-cored sheets increased as the volume fraction of TWIP-cored region increased, and were also well matched with the ones calculated by a rule of mixtures based on volume fraction or force fraction. According to digital image correlation and electron back-scatter diffraction analyses, very high strain hardening effect in the initial deformation stage and active twin formation in the interfacial region beneficially affected the overall homogeneous deformation in the TWIP-cored sheets without any yield point phenomenon occurring in the LC sheet and serrations occurring in the TWIP sheet, respectively. These TWIP-cored sheets can cover a wide range of yield strength, tensile strength, and ductility levels, e.g., 320~498 MPa, 545~878 MPa, and 48~54%, respectively, by controlling the volume fraction of TWIP-cored region, and thus present new applications to multi-functional automotive steel sheets requiring excellent properties. PMID:28067318

Tensile property improvement of TWIP-cored three-layer steel sheets fabricated by hot-roll-bonding with low-carbon steel or interstitial-free steel

NASA Astrophysics Data System (ADS)

Park, Jaeyeong; Kim, Jung-Su; Kang, Minju; Sohn, Seok Su; Cho, Won Tae; Kim, Hyoung Seop; Lee, Sunghak

2017-01-01

TWIP-cored three-layer steel sheets were newly fabricated by hot rolling of TWIP steel sheet surrounded by low-carbon (LC) or interstitial-free (IF) steel sheets. TWIP/LC or TWIP/IF interfaces were well bonded without pores or voids, while a few pearlites were thinly formed along the interfaces. The strengths and elongation of the TWIP-cored sheets increased as the volume fraction of TWIP-cored region increased, and were also well matched with the ones calculated by a rule of mixtures based on volume fraction or force fraction. According to digital image correlation and electron back-scatter diffraction analyses, very high strain hardening effect in the initial deformation stage and active twin formation in the interfacial region beneficially affected the overall homogeneous deformation in the TWIP-cored sheets without any yield point phenomenon occurring in the LC sheet and serrations occurring in the TWIP sheet, respectively. These TWIP-cored sheets can cover a wide range of yield strength, tensile strength, and ductility levels, e.g., 320~498 MPa, 545~878 MPa, and 48~54%, respectively, by controlling the volume fraction of TWIP-cored region, and thus present new applications to multi-functional automotive steel sheets requiring excellent properties.

Magneto-hydrodynamics of coupled fluid-sheet interface with mass suction and blowing

NASA Astrophysics Data System (ADS)

Ahmad, R.

2016-01-01

There are large number of studies which prescribe the kinematics of the sheet and ignore the sheet's mechanics. However, the current boundary layer analysis investigates the mechanics of both the electrically conducting fluid and a permeable sheet, which makes it distinct from the other studies in the literature. One of the objectives of the current study is to (i) examine the behaviour of magnetic field effect for both the surface and the electrically conducting fluid (ii) investigate the heat and mass transfer between a permeable sheet and the surrounding electrically conducting fluid across the hydro, thermal and mass boundary layers. Self-similar solutions are obtained by considering the RK45 technique. Analytical solution is also found for the stretching sheet case. The skin friction dual solutions are presented for various types of sheet. The influence of pertinent parameters on the dimensionless velocity, shear stress, temperature, mass concentration, heat and mass transfer rates on the fluid-sheet interface is presented graphically as well as numerically. The obtained results are of potential benefit for studying the electrically conducting flow over various soft surfaces such as synthetic plastics, soft silicone sheet and soft synthetic rubber sheet. These surfaces are easily deformed by thermal fluctuations or thermal stresses.

Structure, burial history, and petroleum potential of frontal thrust belt and adjacent foreland, southwest Montana.

USGS Publications Warehouse

Perry, W.J.; Wardlaw, B.R.; Bostick, N.H.; Maughan, E.K.

1983-01-01

The frontal thrust belt in the Lima area of SW Montana consists of blind (nonsurfacing) thrusts of the Lima thrust system beneath the Lima anticline and the Tendoy thrust sheet to the W. The Tendoy sheet involves Mississippian through Cretaceous rocks of the SW-plunging nose of the Mesozoic Blacktail-Snowcrest uplift that are thrust higher (NE) onto the uplift. The front of the Tendoy sheet W of Lima locally has been warped by later compressive deformation which also involved synorogenic conglomerates of the structurally underlying Beaverhead Formation. To the N, recent extension faulting locally has dropped the front of the Tendoy sheet beneath Quaternary gravels. Rocks of the exposed Tendoy sheet have never been deeply buried, based on vitrinite relectance of = or <0.6%, conodont CAI (color alteration index) values that are uniformly 1, and on supporting organic geochemical data from Paleozoic rocks from the Tendoy thrust sheet. Directly above and W of the Tendoy sheet lie formerly more deeply buried rocks of the Medicine Lodge thrust system. Their greater burial depth is indicated by higher conodont CAI values. W-dipping post-Paleocene extension faults truncate much of the rear part of the Tendoy sheet and also separate the Medicine Lodge sheet from thrust sheets of the Beaverhead Range still farther W. -from Authors

Commercial scale production of Fe-6.5 wt. % Si sheet and its magnetic properties

NASA Astrophysics Data System (ADS)

Takada, Y.; Abe, M.; Masuda, S.; Inagaki, J.

1988-11-01

Commercial scale production of a Fe-6.5 wt. % Si sheet has been successfully developed. Presently manufactured sheets are in coil form, whose thickness ranges from 0.1 to 0.5 mm with a maximum width of 400 mm. Magnetic properties of the manufactured sheet have been investigated. The permeability of Fe-6.5 wt. % Si sheet is about 10 times higher than the conventional nonoriented silicon steel sheet. The core losses are less than half the conventional, and even less than that of the grain-oriented silicon steel sheet at frequencies over 400 Hz. Superior soft magnetic properties are attributed to the low magnetostriction and high electric resistivity of this alloy. It is well known that the Fe-6.5 wt. % Si alloy has poor ductility in conventional mechanical work. But investigation of the forming conditions has enabled the stamping and bending of alloy sheets. Low core losses and high permeability make Fe-6.5 wt. % Si sheet adequate for motor cores, transformer cores operating at high frequencies, and magnetic shielding. Application to the micromotor core shows that Fe-6.5 wt. % Si sheet reduces the consumption of no-load electric current by 25% in comparison with the conventional silicon steel.

Tensile property improvement of TWIP-cored three-layer steel sheets fabricated by hot-roll-bonding with low-carbon steel or interstitial-free steel.

PubMed

Park, Jaeyeong; Kim, Jung-Su; Kang, Minju; Sohn, Seok Su; Cho, Won Tae; Kim, Hyoung Seop; Lee, Sunghak

2017-01-09

TWIP-cored three-layer steel sheets were newly fabricated by hot rolling of TWIP steel sheet surrounded by low-carbon (LC) or interstitial-free (IF) steel sheets. TWIP/LC or TWIP/IF interfaces were well bonded without pores or voids, while a few pearlites were thinly formed along the interfaces. The strengths and elongation of the TWIP-cored sheets increased as the volume fraction of TWIP-cored region increased, and were also well matched with the ones calculated by a rule of mixtures based on volume fraction or force fraction. According to digital image correlation and electron back-scatter diffraction analyses, very high strain hardening effect in the initial deformation stage and active twin formation in the interfacial region beneficially affected the overall homogeneous deformation in the TWIP-cored sheets without any yield point phenomenon occurring in the LC sheet and serrations occurring in the TWIP sheet, respectively. These TWIP-cored sheets can cover a wide range of yield strength, tensile strength, and ductility levels, e.g., 320~498 MPa, 545~878 MPa, and 48~54%, respectively, by controlling the volume fraction of TWIP-cored region, and thus present new applications to multi-functional automotive steel sheets requiring excellent properties.

Controlling microstructure and texture in magnesium alloy sheet by shear-based deformation processing

NASA Astrophysics Data System (ADS)

Sagapuram, Dinakar

Application of lightweight Mg sheet is limited by its low workability, both in production of sheet (typically by multistep hot and cold-rolling) and forming of sheet into components. Large strain extrusion machining (LSEM), a constrained chip formation process, is used to create Mg alloy AZ31B sheet in a single deformation step. The deformation in LSEM is shown to be intense simple shear that is confined to a narrow zone, which results in significant deformation-induced heating up to ~ 200°C and reduces the need for pre-heating to realize continuous sheet forms. This study focuses on the texture and microstructure development in the sheet processed by LSEM. Interestingly, deep, highly twinned steady-state layer develops in the workpiece subsurface due to the compressive field ahead of the shear zone. The shear deformation, in conjunction with this pre-deformed twinned layer, results in tilted-basal textures in the sheet with basal planes tilted well away from the surface. These textures are significantly different from those in rolled sheet, where basal planes are nearly parallel to the surface. By controlling the strain path, the basal plane inclination from the surface could be varied in the range of 32-53°. B-fiber (basal plane parallel to LSEM shear plane), associated with basal slip, is the major texture component in the sheet. An additional minor C2-fiber component appears above 250°C due to the thermal activation of pyramidal slip. Together with these textures, microstructure ranges from severely cold-worked to (dynamically) recrystallized type, with the corresponding grain sizes varying from ultrafine- (~ 200 nm) to fine- (2 mum) grained. Small-scale limiting dome height (LDH) confirmed enhanced formability (~ 50% increase in LDH) of LSEM sheet over the conventional rolled sheet. Premature, twinning-driven shear fractures are observed in the rolled sheet with the basal texture. In contrast, LSEM sheet with a tilted-basal texture favorably oriented for basal slip exhibits ductile tensile-type fracture. A two-fold increase in ductility is also observed for the LSEM sheet under uniaxial tensile testing without significant changes in the strength. Among texture and microstructure (grain size), texture is shown to be more critical for Mg sheet formability. However, in conjunction with a favorable texture, fine recrystallized microstructure provides for additional enhancement of strain-hardening capacity and formability. In-situ imaging of material flow during uniaxial tensile testing revealed new, interesting flow localization phenomena and fracture behavior. It is shown that the deformation behavior of Mg sheet is highly texture dependent, and also radically different from that of conventional ductile metals both in terms of necking and fracture. The implications of these observations for the LDH test results and formability of Mg sheet, in general, are briefly discussed.

THE DYNAMICAL GENERATION OF CURRENT SHEETS IN ASTROPHYSICAL PLASMA TURBULENCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Howes, Gregory G.

2016-08-20

Turbulence profoundly affects particle transport and plasma heating in many astrophysical plasma environments, from galaxy clusters to the solar corona and solar wind to Earth's magnetosphere. Both fluid and kinetic simulations of plasma turbulence ubiquitously generate coherent structures, in the form of current sheets, at small scales, and the locations of these current sheets appear to be associated with enhanced rates of dissipation of the turbulent energy. Therefore, illuminating the origin and nature of these current sheets is critical to identifying the dominant physical mechanisms of dissipation, a primary aim at the forefront of plasma turbulence research. Here, we presentmore » evidence from nonlinear gyrokinetic simulations that strong nonlinear interactions between counterpropagating Alfvén waves, or strong Alfvén wave collisions, are a natural mechanism for the generation of current sheets in plasma turbulence. Furthermore, we conceptually explain this current sheet development in terms of the nonlinear dynamics of Alfvén wave collisions, showing that these current sheets arise through constructive interference among the initial Alfvén waves and nonlinearly generated modes. The properties of current sheets generated by strong Alfvén wave collisions are compared to published observations of current sheets in the Earth's magnetosheath and the solar wind, and the nature of these current sheets leads to the expectation that Landau damping of the constituent Alfvén waves plays a dominant role in the damping of turbulently generated current sheets.« less

Preliminary Investigation of Impact on Multiple-Sheet Structures and an Evaluation of the Meteoroid Hazard to Space Vehicles

NASA Technical Reports Server (NTRS)

Nysmith, C. Robert; Summers, James L.

1961-01-01

Small pyrex glass spheres, representative of stoney meteoroids, were fired into 2024-T3 aluminum alclad multiple-sheet structures at velocities to 11,000 feet per second to evaluate the effectiveness of multisheet hull construction as a means of increasing the resistance of a spacecraft to meteoroid penetrations. The results of these tests indicate that increasing the number of sheets in a structure while keeping the total sheet thickness constant and increasing the spacing between sheets both tend to increase the penetration resistance of a structure of constant weight per unit area. In addition, filling the space between the sheets with a light filler material was found to substantially increase structure penetration resistance with a small increase in weight. An evaluation of the meteoroid hazard to space vehicles is presented in the form of an illustrative-example for two specific lunar mission vehicles, a single-sheet, monocoque hull vehicle and a glass-wool filled, double-sheet hull vehicle. The evaluation is presented in terms of the "best" and the "worst" conditions that might be expected as determined from astronomical and satellite measurements, high-speed impact data, and hypothesized meteoroid structures and compositions. It was observed that the vehicle flight time without penetration can be increased significantly by use of multiple-sheet rather than single-sheet hull construction with no increase in hull weight. Nevertheless, it is evident that a meteoroid hazard exists, even for the vehicle with the selected multiple-sheet hull.

History of the Greenland Ice Sheet: paleoclimatic insights

USGS Publications Warehouse

Alley, Richard B.; Andrews, John T.; Brigham-Grette, J.; Clarke, G.K.C.; Cuffey, Kurt M.; Fitzpatrick, J.J.; Funder, S.; Marshall, S.J.; Miller, G.H.; Mitrovica, J.X.; Muhs, D.R.; Otto-Bliesner, B. L.; Polyak, L.; White, J.W.C.

2010-01-01

Paleoclimatic records show that the GreenlandIce Sheet consistently has lost mass in response to warming, and grown in response to cooling. Such changes have occurred even at times of slow or zero sea-level change, so changing sea level cannot have been the cause of at least some of the ice-sheet changes. In contrast, there are no documented major ice-sheet changes that occurred independent of temperature changes. Moreover, snowfall has increased when the climate warmed, but the ice sheet lost mass nonetheless; increased accumulation in the ice sheet's center has not been sufficient to counteract increased melting and flow near the edges. Most documented forcings and ice-sheet responses spanned periods of several thousand years, but limited data also show rapid response to rapid forcings. In particular, regions near the ice margin have responded within decades. However, major changes of central regions of the ice sheet are thought to require centuries to millennia. The paleoclimatic record does not yet strongly constrain how rapidly a major shrinkage or nearly complete loss of the ice sheet could occur. The evidence suggests nearly total ice-sheet loss may result from warming of more than a few degrees above mean 20th century values, but this threshold is poorly defined (perhaps as little as 2 °C or more than 7 °C). Paleoclimatic records are sufficiently sketchy that the ice sheet may have grown temporarily in response to warming, or changes may have been induced by factors other than temperature, without having been recorded.

Triggering of explosive reconnection in a thick current sheet via current sheet compression: Less current sheet thinning, more temperature anisotropy

NASA Astrophysics Data System (ADS)

Shimizu, K.; Shinohara, I.; Fujimoto, M.

2016-12-01

Two-dimensional kinetic simulations of compression of thick current sheets are performed to see how it can lead to triggering of explosive magnetic reconnection. The current sheet under study is simply in a Harris-like anti-paralell and symmetric geometry. A one-dimensional pre-study shows that the compression is more effective to make the plasma anisotropy than to thin the current sheet width. When the lobe magnetic field is amplified by a factor of 2, the plasma temperature anisotropy inside the current sheet reaches 2 but the current sheet thickness is reduced only by 1/sqrt(2). If a current sheet thickness needs to be comparable to the ion inertial scale for reconnection triggering take place, as is widely and frequently mentioned in the research community, the initial thickness cannot be more than a few ion scale for reconnection to set-in. On the other hand, the temperature anisotropy of 2 can be significant for the triggering problem. Two-dimensional simulations show explosive magnetic reconnection to take place even when the initial current sheet thickness more than an order of magnitude thicker than the ion scale, indicating the resilient triggering drive supplied by the temperature anisotropy. We also discuss how the reconnection triggering capability of the temperature anisotropy boosted tearing mode for thick current sheets compares with the instabilities in the plane orthogonal to the reconnecting field.

3D modelling of the Tejeda Caldera cone-sheet swarm, Gran Canaria, Canary Islands, Spain

NASA Astrophysics Data System (ADS)

Samrock, Lisa K.; Jensen, Max J.; Burchardt, Steffi; Troll, Valentin R.; Mattsson, Tobias; Geiger, Harri

2015-04-01

Cone-sheet swarms provide vital information on the interior of volcanic systems and their plumbing systems (e.g. Burchardt et al. 2013). This information is important for the interpretation of processes and dynamics of modern and ancient volcanic systems, and is therefore vital for assessing volcanic hazards and to reduce risks to modern society. To more realistically model cone-sheet emplacement an approximation of their 3D shape needs to be known. Most cone-sheet swarms are not sufficiently exposed laterally and/or vertically, however, which makes it difficult to determine the geometry of a cone-sheet swarm at depth, especially since different shapes (e.g. convex, straight or concave continuations) would produce a similar trace at the surface (cf. Burchardt et al. 2011, and references therein). The Miocene Tejeda Caldera on Gran Canaria, Canary Islands, Spain, hosts a cone-sheet swarm that was emplaced into volcaniclastic caldera infill at about 12.3-7.3 Ma (Schirnick et al. 1999). The dyke swarm displays over 1000 m of vertical exposure and more than 15 km of horizontal exposure, making it a superb locality to study the evolution of cone-sheet swarms in detail and to determine its actual geometry in 3D space. We have used structural data of Schirnick (1996) to model the geometry of the Tejeda cone-sheet in 3D, using the software Move® by Midland Valley Ltd. Based on previous 2D projections, Schirnick et al. (1999) suggested that the cone-sheet swarm is formed by a stack of parallel intrusive sheets which have a truncated dome geometry and form a concentric structure around a central axis, assuming straight sheet-intrusions. Our 3D model gives insight into the symmetries of the sheets and the overall geometry of the cone-sheet swarm below the surface. This visualization now allows to grasp the complexity of the Tejeda cone-sheet swarm at depth, particularly in relation to different possible cone-sheet geometries suggested in the literature (cf. Burchardt et al. 2011, and references therein), and we discuss the implications of this architecture for the feeding system of the Tejeda volcano and the associated temporal variations of cone-sheet emplacement. References: Burchardt, S., Tanner, D.C., Troll, V.R., Krumbholz, M., Gustafsson, L.E. (2011) Three-dimensional geometry of concentric intrusive sheet swarms in the Geitafell and the Dyrfjöll volcanoes, eastern Iceland. Geochemistry, Geophysics, Geosystems 12(7): Q0AB09. Burchardt, S., Troll, V.R., Mathieu, L., Emeleus, H.C., Donaldson, C.H. (2013) Ardnamruchan 3D cone-sheet architecture explained by a single elongate magma chamber. Scientific Reports 3:2891. Schirnick, C. (1996) Formation of an intracaldera cone sheet dike swarm (Tejeda Caldera, Gran Canaria) (Dissertation). Christian-Albrechts-Universität, Kiel, Germany. Schirnick, C., van den Bogaard, P., Schmincke, H.-U. (1999) Cone-sheet formation and intrusive growth of an oceanic island - The Miocene Tejeda complex on Gran Canaria (Canary Islands). Geology, 27: 207-210.

40 CFR 427.20 - Applicability; description of the asbestos-cement sheet subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... asbestos-cement sheet subcategory. 427.20 Section 427.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Asbestos-Cement Sheet Subcategory § 427.20 Applicability; description of the asbestos-cement sheet...

40 CFR 427.20 - Applicability; description of the asbestos-cement sheet subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... asbestos-cement sheet subcategory. 427.20 Section 427.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Asbestos-Cement Sheet Subcategory § 427.20 Applicability; description of the asbestos-cement sheet...

40 CFR 426.20 - Applicability; description of the sheet glass manufacturing subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... sheet glass manufacturing subcategory. 426.20 Section 426.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Sheet Glass Manufacturing Subcategory § 426.20 Applicability; description of the sheet glass...

40 CFR 426.20 - Applicability; description of the sheet glass manufacturing subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... sheet glass manufacturing subcategory. 426.20 Section 426.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Sheet Glass Manufacturing Subcategory § 426.20 Applicability; description of the sheet glass...

49 CFR 224.5 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., as where a layer of paint or dense chemical residue blocks all incoming light); this term does not... of American Railroads. Unqualified Retroreflective Sheeting means engineering grade sheeting, super engineering grade sheeting (enclosed lens) or high-intensity type sheeting (ASTM Type I, II, III, or IV...

Development of a highly transparent superamphiphobic plastic sheet by nanoparticle and chemical coating.

PubMed

Wong, Ten It; Wang, Hao; Wang, Fuke; Sin, Sau Leng; Quan, Cheng Gen; Wang, Shi Jie; Zhou, Xiaodong

2016-04-01

A highly transparent superamphiphobic plastic sheet was developed. The plastic sheet polymethyl methacrylate (PMMA) was spin-coated on a glass substrate. Synthesized silica nanoparticles were sprayed on PMMA, followed by fluorosilane drop-coating. The results of contact angle measurements show that the developed PMMA sheet has superamphiphobic properties with high advancing contact angles for water (154°), toluene (139°), and silicone oil (132.9°). The amphiphobicity of the plastic sheet can be tuned by the surface coverage of the silica nanoparticles distributed on the PMMA surface. The surface coverage of the nanoparticles on our PMMA sheet is about 20%, and it agrees with our contact angle calculations for the sheet with and without nanoparticles. Copyright © 2016 Elsevier Inc. All rights reserved.

Dynamics of Radially Expanding Liquid Sheets

NASA Astrophysics Data System (ADS)

Majumdar, Nayanika; Tirumkudulu, Mahesh S.

2018-04-01

The process of atomization often involves ejecting thin liquid sheets at high speeds from a nozzle that causes the sheet to flap violently and break up into fine droplets. The flapping of the liquid sheet has long been attributed to the sheet's interaction with the surrounding gas phase. Here, we present experimental evidence to the contrary and show that the flapping is caused by the thinning of the liquid sheet as it spreads out from the nozzle exit. The measured growth rates of the waves agree remarkably well with the predictions of a recent theory that accounts for the sheet's thinning but ignores aerodynamic interactions. We anticipate these results to not only lead to more accurate predictions of the final drop-size distribution but also enable more efficient designs of atomizers.

Interhemispheric ice-sheet synchronicity during the last glacial maximum

USGS Publications Warehouse

Weber, Michael E.; Clark, Peter U.; Ricken, Werner; Mitrovica, Jerry X.; Hostetler, Steven W.; Kuhn, Gerhard

2011-01-01

The timing of the last maximum extent of the Antarctic ice sheets relative to those in the Northern Hemisphere remains poorly understood. We develop a chronology for the Weddell Sea sector of the East Antarctic Ice Sheet that, combined with ages from other Antarctic ice-sheet sectors, indicates that the advance to and retreat from their maximum extent was within dating uncertainties synchronous with most sectors of Northern Hemisphere ice sheets. Surface climate forcing of Antarctic mass balance would probably cause an opposite response, whereby a warming climate would increase accumulation but not surface melting. Our new data support teleconnections involving sea-level forcing from Northern Hemisphere ice sheets and changes in North Atlantic deep-water formation and attendant heat flux to Antarctic grounding lines to synchronize the hemispheric ice sheets.

Interhemispheric ice-sheet synchronicity during the Last Glacial Maximum.

PubMed

Weber, Michael E; Clark, Peter U; Ricken, Werner; Mitrovica, Jerry X; Hostetler, Steven W; Kuhn, Gerhard

2011-12-02

The timing of the last maximum extent of the Antarctic ice sheets relative to those in the Northern Hemisphere remains poorly understood. We develop a chronology for the Weddell Sea sector of the East Antarctic Ice Sheet that, combined with ages from other Antarctic ice-sheet sectors, indicates that the advance to and retreat from their maximum extent was within dating uncertainties synchronous with most sectors of Northern Hemisphere ice sheets. Surface climate forcing of Antarctic mass balance would probably cause an opposite response, whereby a warming climate would increase accumulation but not surface melting. Our new data support teleconnections involving sea-level forcing from Northern Hemisphere ice sheets and changes in North Atlantic deep-water formation and attendant heat flux to Antarctic grounding lines to synchronize the hemispheric ice sheets.

Interhemispheric ice-sheet synchronicity during the Last Glacial Maximum

NASA Astrophysics Data System (ADS)

Weber, M. E.; Clark, P. U.; Ricken, W.; Mitrovica, J. X.; Hostetler, S. W.; Kuhn, G.

2012-04-01

The timing of the last maximum extent of the Antarctic ice sheets relative to those in the Northern Hemisphere remains poorly understood because only a few findings with robust chronologies exist for Antarctic ice sheets. We developed a chronology for the Weddell Sea sector of the East Antarctic ice sheet that, combined with ages from other Antarctic ice-sheet sectors, indicates the advance to their maximum extent at 29 -28 ka, and retreat from their maximum extent at 19 ka was nearly synchronous with Northern Hemisphere ice sheets (Weber, M.E., Clark, P. U., Ricken, W., Mitrovica, J. X., Hostetler, S. W., and Kuhn, G. (2011): Interhemispheric ice-sheet synchronicity during the Last Glacial Maximum. - Science, 334, 1265-1269, doi: 10.1126:science.1209299). As for the deglaciation, modeling studies suggest a late ice-sheet retreat starting around 14 ka BP and ending around 7 ka BP with a large impact of an unstable West Antarctic Ice Sheet (WAIS) and a small impact of a stable East Antarctic Ice Sheet (EAIS). However, the Weddell Sea sites studied here, as well as sites from the Scotia Sea, provide evidence that specifically the EAIS responded much earlier, possibly provided a significant contribution to the last sea-level rise, and was much more dynamic than previously thought. Using the results of an atmospheric general circulation we conclude that surface climate forcing of Antarctic ice mass balance would likely cause an opposite response, whereby a warming climate would increase accumulation but not surface melting. Furthermore, our new data support teleconnections involving a sea-level fingerprint forced from Northern Hemisphere ice sheets as indicated by gravitational modeling. Also, changes in North Atlantic Deepwater formation and attendant heat flux to Antarctic grounding lines may have contributed to synchronizing the hemispheric ice sheets.

Design and results of the ice sheet model initialisation experiments initMIP-Greenland: an ISMIP6 intercomparison

NASA Astrophysics Data System (ADS)

Goelzer, Heiko; Nowicki, Sophie; Edwards, Tamsin; Beckley, Matthew; Abe-Ouchi, Ayako; Aschwanden, Andy; Calov, Reinhard; Gagliardini, Olivier; Gillet-Chaulet, Fabien; Golledge, Nicholas R.; Gregory, Jonathan; Greve, Ralf; Humbert, Angelika; Huybrechts, Philippe; Kennedy, Joseph H.; Larour, Eric; Lipscomb, William H.; Le clec'h, Sébastien; Lee, Victoria; Morlighem, Mathieu; Pattyn, Frank; Payne, Antony J.; Rodehacke, Christian; Rückamp, Martin; Saito, Fuyuki; Schlegel, Nicole; Seroussi, Helene; Shepherd, Andrew; Sun, Sainan; van de Wal, Roderik; Ziemen, Florian A.

2018-04-01

Earlier large-scale Greenland ice sheet sea-level projections (e.g. those run during the ice2sea and SeaRISE initiatives) have shown that ice sheet initial conditions have a large effect on the projections and give rise to important uncertainties. The goal of this initMIP-Greenland intercomparison exercise is to compare, evaluate, and improve the initialisation techniques used in the ice sheet modelling community and to estimate the associated uncertainties in modelled mass changes. initMIP-Greenland is the first in a series of ice sheet model intercomparison activities within ISMIP6 (the Ice Sheet Model Intercomparison Project for CMIP6), which is the primary activity within the Coupled Model Intercomparison Project Phase 6 (CMIP6) focusing on the ice sheets. Two experiments for the large-scale Greenland ice sheet have been designed to allow intercomparison between participating models of (1) the initial present-day state of the ice sheet and (2) the response in two idealised forward experiments. The forward experiments serve to evaluate the initialisation in terms of model drift (forward run without additional forcing) and in response to a large perturbation (prescribed surface mass balance anomaly); they should not be interpreted as sea-level projections. We present and discuss results that highlight the diversity of data sets, boundary conditions, and initialisation techniques used in the community to generate initial states of the Greenland ice sheet. We find good agreement across the ensemble for the dynamic response to surface mass balance changes in areas where the simulated ice sheets overlap but differences arising from the initial size of the ice sheet. The model drift in the control experiment is reduced for models that participated in earlier intercomparison exercises.

Design and results of the ice sheet model initialisation experiments initMIP-Greenland: an ISMIP6 intercomparison

DOE PAGES

Goelzer, Heiko; Nowicki, Sophie; Edwards, Tamsin; ...

2018-04-19

Earlier large-scale Greenland ice sheet sea-level projections (e.g. those run during the ice2sea and SeaRISE initiatives) have shown that ice sheet initial conditions have a large effect on the projections and give rise to important uncertainties. Here, the goal of this initMIP-Greenland intercomparison exercise is to compare, evaluate, and improve the initialisation techniques used in the ice sheet modelling community and to estimate the associated uncertainties in modelled mass changes. initMIP-Greenland is the first in a series of ice sheet model intercomparison activities within ISMIP6 (the Ice Sheet Model Intercomparison Project for CMIP6), which is the primary activity within themore » Coupled Model Intercomparison Project Phase 6 (CMIP6) focusing on the ice sheets. Two experiments for the large-scale Greenland ice sheet have been designed to allow intercomparison between participating models of (1) the initial present-day state of the ice sheet and (2) the response in two idealised forward experiments. The forward experiments serve to evaluate the initialisation in terms of model drift (forward run without additional forcing) and in response to a large perturbation (prescribed surface mass balance anomaly); they should not be interpreted as sea-level projections. We present and discuss results that highlight the diversity of data sets, boundary conditions, and initialisation techniques used in the community to generate initial states of the Greenland ice sheet. We find good agreement across the ensemble for the dynamic response to surface mass balance changes in areas where the simulated ice sheets overlap but differences arising from the initial size of the ice sheet. The model drift in the control experiment is reduced for models that participated in earlier intercomparison exercises.« less

Design and results of the ice sheet model initialisation experiments initMIP-Greenland: an ISMIP6 intercomparison

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goelzer, Heiko; Nowicki, Sophie; Edwards, Tamsin

Earlier large-scale Greenland ice sheet sea-level projections (e.g. those run during the ice2sea and SeaRISE initiatives) have shown that ice sheet initial conditions have a large effect on the projections and give rise to important uncertainties. Here, the goal of this initMIP-Greenland intercomparison exercise is to compare, evaluate, and improve the initialisation techniques used in the ice sheet modelling community and to estimate the associated uncertainties in modelled mass changes. initMIP-Greenland is the first in a series of ice sheet model intercomparison activities within ISMIP6 (the Ice Sheet Model Intercomparison Project for CMIP6), which is the primary activity within themore » Coupled Model Intercomparison Project Phase 6 (CMIP6) focusing on the ice sheets. Two experiments for the large-scale Greenland ice sheet have been designed to allow intercomparison between participating models of (1) the initial present-day state of the ice sheet and (2) the response in two idealised forward experiments. The forward experiments serve to evaluate the initialisation in terms of model drift (forward run without additional forcing) and in response to a large perturbation (prescribed surface mass balance anomaly); they should not be interpreted as sea-level projections. We present and discuss results that highlight the diversity of data sets, boundary conditions, and initialisation techniques used in the community to generate initial states of the Greenland ice sheet. We find good agreement across the ensemble for the dynamic response to surface mass balance changes in areas where the simulated ice sheets overlap but differences arising from the initial size of the ice sheet. The model drift in the control experiment is reduced for models that participated in earlier intercomparison exercises.« less

Rotator cuff repair using cell sheets derived from human rotator cuff in a rat model.

PubMed

Harada, Yoshifumi; Mifune, Yutaka; Inui, Atsuyuki; Sakata, Ryosuke; Muto, Tomoyuki; Takase, Fumiaki; Ueda, Yasuhiro; Kataoka, Takeshi; Kokubu, Takeshi; Kuroda, Ryosuke; Kurosaka, Masahiro

2017-02-01

To achieve biological regeneration of tendon-bone junctions, cell sheets of human rotator-cuff derived cells were used in a rat rotator cuff injury model. Human rotator-cuff derived cells were isolated, and cell sheets were made using temperature-responsive culture plates. Infraspinatus tendons in immunodeficient rats were resected bilaterally at the enthesis. In right shoulders, infraspinatus tendons were repaired by the transosseous method and covered with the cell sheet (sheet group), whereas the left infraspinatus tendons were repaired in the same way without the cell sheet (control group). Histological examinations (safranin-O and fast green staining, isolectin B4, type II collagen, and human-specific CD31) and mRNA expression (vascular endothelial growth factor; VEGF, type II collagen; Col2, and tenomodulin; TeM) were analyzed 4 weeks after surgery. Biomechanical tests were performed at 8 weeks. In the sheet group, proteoglycan at the enthesis with more type II collagen and isolectin B4 positive cells were seen compared with in the control group. Human specific CD31-positive cells were detected only in the sheet group. VEGF and Col2 gene expressions were higher and TeM gene expression was lower in the sheet group than in the control group. In mechanical testing, the sheet group showed a significantly higher ultimate failure load than the control group at 8 weeks. Our results indicated that the rotator-cuff derived cell sheet could promote cartilage regeneration and angiogenesis at the enthesis, with superior mechanical strength compared with the control. Treatment for rotator cuff injury using cell sheets could be a promising strategy for enthesis of tendon tissue engineering. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:289-296, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

A recipe for designing water-soluble, beta-sheet-forming peptides.

PubMed Central

Mayo, K. H.; Ilyina, E.; Park, H.

1996-01-01

Based on observations of solubility and folding properties of peptide 33-mers derived from the beta-sheet domains of platelet factor-4 (PF4), interleukin-8 (IL-8), and growth related protein (Gro-alpha), as well as other beta-sheet-forming peptides, general guidelines have been developed to aid in the design of water soluble, self-association-induced beta-sheet-forming peptides. CD, 1H-NMR, and pulsed field gradient NMR self-diffusion measurements have been used to assess the degree of folding and state of aggregation. PF4 peptide forms native-like beta-sheet tetramers and is sparingly soluble above pH 6. IL-8 peptide is insoluble between pH 4.5 and pH 7.5, yet forms stable, native-like beta-sheet dimers at higher pH. Gro-alpha peptide is soluble at all pH values, yet displays no discernable beta-sheet structure even when diffusion data indicate dimer-tetramer aggregation. A recipe used in the de novo design of water-soluble beta-sheet-forming peptides calls for the peptide to contain 40-50% hydrophobic residues, usually aliphatic ones (I, L, V, A, M) (appropriately paired and mostly but not always alternating with polar residues in the sheet sequence), a positively charged (K, R) to negatively charged (E, D) residue ratio between 4/2 and 6/2, and a noncharged polar residue (N, Q, T, S) composition of about 20% or less. Results on four de novo designed, 33-residue peptides are presented supporting this approach. Under near physiologic conditions, all four peptides are soluble, form beta-sheet structures to varying degrees, and self-associate. One peptide folds as a stable, compact beta-sheet tetramer, whereas the others are transient beta-sheet-containing aggregates. PMID:8819163

Ice sheet climate modeling: past achievements, ongoing challenges, and future endeavors

NASA Astrophysics Data System (ADS)

Lenaerts, J.

2017-12-01

Fluctuations in surface mass balance (SMB) mask out a substantial portion of contemporary Greenland and Antarctic ice sheet mass loss. That implies that we need accurate, consistent, and long-term SMB time series to isolate the mass loss signal. This in turn requires understanding of the processes driving SMB, and how they interplay. The primary controls on present-day ice sheet SMB are snowfall, which is regulated by large-scale atmospheric variability, and surface meltwater production at the ice sheet's edges, which is a complex result of atmosphere-surface interactions. Additionally, wind-driven snow redistribution and sublimation are large SMB contributors on the downslope areas of the ice sheets. Climate models provide an integrated framework to simulate all these individual ice sheet components. Recent developments in RACMO2, a regional climate model bound by atmospheric reanalyses, have focused on enhancing horizontal resolution, including blowing snow, snow albedo, and meltwater processes. Including these physics not only enhanced our understanding of the ice sheet climate system, but also enabled to obtain increasingly accurate estimates of ice sheet SMB. However, regional models are not suitable to capture the mutual interactions between ice sheet and the remainder of the global climate system in transient climates. To take that next step, global climate models are essential. In this talk, I will highlight our present work on improving ice sheet climate in the Community Earth System Model (CESM). In particular, we focus on an improved representation of polar firn, ice sheet clouds, and precipitation. For this exercise, we extensively use field observations, remote sensing data, as well as RACMO2. Next, I will highlight how CESM is used to enhance our understanding of ice sheet SMB, its drivers, and past and present changes.

Using an extreme bony prominence anatomical model to examine the influence of bed sheet materials and bed making methods on the distribution of pressure on the support surface.

PubMed

Iuchi, Terumi; Nakajima, Yukari; Fukuda, Moriyoshi; Matsuo, Junko; Okamoto, Hiroyuki; Sanada, Hiromi; Sugama, Junko

2014-05-01

Bed sheets generate high surface tension across the support surface and increase pressure to the body through a process known as the hammock effect. Using an anatomical model and a loading device characterized by extreme bony prominences, the present study compared pressure distributions on support surfaces across different bed making methods and bed sheet materials to determine the factors that influence pressure distribution. The model was placed on a pressure mapping system (CONFORMat; NITTA Corp., Osaka, Japan), and interface pressure was measured. Bed sheet elasticity and friction between the support surface and the bed sheets were also measured. For maximum interface pressure, the relative values of the following methods were higher than those of the control method, which did not use any bed sheets: cotton sheets with hospital corners (1.28, p = 0.02), polyester with no corners (1.29, p = 0.01), cotton with no corners (1.31, p = 0.003), and fitted polyester sheets (1.35, p = 0.002). Stepwise multiple regression analysis indicated that maximum interface pressure was negatively correlated with bed sheet elasticity (R(2) = 0.74). A statistically significant negative correlation was observed between maximum interface pressure and immersion depth, which was measured using the loading device (r = -0.40 and p = 0.04). We found that several combinations of bed making methods and bed sheet materials induced maximum interface pressures greater than those observed for the control method. Bed sheet materials influenced maximum interface pressure, and bed sheet elasticity was particularly important in reducing maximum interface pressure. Copyright © 2014 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

Estimating the impact of internal climate variability on ice sheet model simulations

NASA Astrophysics Data System (ADS)

Tsai, C. Y.; Forest, C. E.; Pollard, D.

2016-12-01

Rising sea level threatens human societies and coastal habitats and melting ice sheets are a major contributor to sea level rise (SLR). Thus, understanding uncertainty of both forcing and variability within the climate system is essential for assessing long-term risk of SLR given their impact on ice sheet evolution. The predictability of polar climate is limited by uncertainties from the given forcing, the climate model response to this forcing, and the internal variability from feedbacks within the fully coupled climate system. Among those sources of uncertainty, the impact of internal climate variability on ice sheet changes has not yet been robustly assessed. Here we investigate how internal variability affects ice sheet projections using climate fields from two Community Earth System Model (CESM) large-ensemble (LE) experiments to force a three-dimensional ice sheet model. Each ensemble member in an LE experiment undergoes the same external forcings but with unique initial conditions. We find that for both LEs, 2m air temperature variability over Greenland ice sheet (GrIS) can lead to significantly different ice sheet responses. Our results show that the internal variability from two fully coupled CESM LEs can cause about 25 35 mm differences of GrIS's contribution to SLR in 2100 compared to present day (about 20% of the total change), and 100m differences of SLR in 2300. Moreover, only using ensemble-mean climate fields as the forcing in ice sheet model can significantly underestimate the melt of GrIS. As the Arctic region becomes warmer, the role of internal variability is critical given the complex nonlinear interactions between surface temperature and ice sheet. Our results demonstrate that internal variability from coupled atmosphere-ocean general circulation model can affect ice sheet simulations and the resulting sea-level projections. This study highlights an urgent need to reassess associated uncertainties of projecting ice sheet loss over the next few centuries to obtain robust estimates of the contribution of ice sheet melt to SLR.

A Statistical Model of the Magnetotail Neutral Sheet

NASA Astrophysics Data System (ADS)

Xiao, Sudong; Zhang, Tielong; Baumjohann, Wolfgang; Nakamura, Rumi; Ge, Yasong; Du, Aimin; Wang, Guoqiang; Lu, Quanming

2015-04-01

The neutral sheet of the magnetotail is characterized by weak magnetic field, strong cross tail current, and a reversal of the magnetic field direction across it. The dynamics of the earth's magnetosphere is greatly influenced by physical processes that occur near the neutral sheet. However, the exact position of the neutral sheet is variable in time. It is therefore essential to have a reliable estimate of the average position of the neutral sheet. Magnetic field data from ten years of Cluster, nineteen years of Geotail, four years of TC 1, and seven years of THEMIS observations have been incorporated to obtain a model of the magnetotail neutral sheet. All data in aberrated GSM (Geocentric Solar Magnetospheric) coordinate system are normalized to the same solar wind pressure condition. The shape and position of the neutral sheet, illustrated directly by the separator of positive and negative Bx on the YZ cross sections, are fitted with a displaced ellipse model. It is consistent with previous studies that the neutral sheet becomes curvier in the YZ cross section when the dipole tilt increases, yet our model shows the curviest neutral sheet compared with previous models. The new model reveals a hinging distance very close to 10 RE at a reference solar wind dynamic pressure of 2 nPa. We find that the earth dipole tilt angle not only affects the neutral sheet configuration in the YZ cross section but also in the XZ cross section. The neutral sheet becomes more tilting in the XZ cross section when the dipole tilt increases. The effect of an interplanetary magnetic field (IMF) penetration is studied, and an IMF By-related twisting of about 3° is found. Anticlockwise twisting of the neutral sheet is observed, looking along the downtail direction, for a positive IMF By, and clockwise twisting of the neutral sheet for a negative IMF By.

Probability based hydrologic catchments of the Greenland Ice Sheet

NASA Astrophysics Data System (ADS)

Hudson, B. D.

2015-12-01

Greenland Ice Sheet melt water impacts ice sheet flow dynamics, fjord and coastal circulation, and sediment and biogeochemical fluxes. Melt water exiting the ice sheet also is a key term in its mass balance. Because of this, knowledge of the area of the ice sheet that contributes melt water to a given outlet (its hydrologic catchment) is important to many ice sheet studies and is especially critical to methods using river runoff to assess ice sheet mass balance. Yet uncertainty in delineating ice sheet hydrologic catchments is a problem that is rarely acknowledged. Ice sheet catchments are delineated as a function of both basal and surface topography. While surface topography is well known, basal topography is less certain because it is dependent on radar surveys. Here, I a present a Monte Carlo based approach to delineating ice sheet catchments that quantifies the impact of uncertain basal topography. In this scheme, over many iterations I randomly vary the ice sheet bed elevation within published error bounds (using Morlighem et al., 2014 bed and bed error datasets). For each iteration of ice sheet bed elevation, I calculate the hydraulic potentiometric surface and route water over its path of 'steepest' descent to delineate the catchment. I then use all realizations of the catchment to arrive at a probability map of all major melt water outlets in Greenland. I often find that catchment size is uncertain, with small, random perturbations in basal topography leading to large variations in catchments size. While some catchments are well defined, others can double or halve in size within published basal topography error bars. While some uncertainty will likely always remain, this work points to locations where studies of ice sheet hydrology would be the most successful, allows reinterpretation of past results, and points to where future radar surveys would be most advantageous.

40 CFR 427.20 - Applicability; description of the asbestos-cement sheet subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... asbestos-cement sheet subcategory. 427.20 Section 427.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Asbestos-Cement Sheet Subcategory § 427.20 Applicability; description of the asbestos-cement sheet...

40 CFR 427.20 - Applicability; description of the asbestos-cement sheet subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... asbestos-cement sheet subcategory. 427.20 Section 427.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Asbestos-Cement Sheet Subcategory § 427.20 Applicability; description of the asbestos-cement sheet...

40 CFR 427.20 - Applicability; description of the asbestos-cement sheet subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... asbestos-cement sheet subcategory. 427.20 Section 427.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Asbestos-Cement Sheet Subcategory § 427.20 Applicability; description of the asbestos-cement sheet...

49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

Code of Federal Regulations, 2012 CFR

2012-10-01

... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect. ...

49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

Code of Federal Regulations, 2014 CFR

2014-10-01

... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect. ...

49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

Code of Federal Regulations, 2013 CFR

2013-10-01

... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect. ...

49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

Code of Federal Regulations, 2011 CFR

2011-10-01

... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect. ...

47 CFR 32.3000 - Instructions for balance sheet accounts-Depreciation and amortization.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Instructions for balance sheet accounts-Depreciation and amortization. 32.3000 Section 32.3000 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... for Balance Sheet Accounts § 32.3000 Instructions for balance sheet accounts—Depreciation and...

47 CFR 32.3000 - Instructions for balance sheet accounts-Depreciation and amortization.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 2 2011-10-01 2011-10-01 false Instructions for balance sheet accounts-Depreciation and amortization. 32.3000 Section 32.3000 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... for Balance Sheet Accounts § 32.3000 Instructions for balance sheet accounts—Depreciation and...

75 FR 45144 - Recovery Fact Sheet 9580.203, Debris Monitoring

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-02

...] Recovery Fact Sheet 9580.203, Debris Monitoring AGENCY: Federal Emergency Management Agency, DHS. ACTION... accepting comments on Recovery Fact Sheet 9580.203, Debris Monitoring. DATES: Comments must be received by... guidelines. Specifically, the fact sheet provides information on debris monitoring roles and responsibilities...

49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

Code of Federal Regulations, 2010 CFR

2010-10-01

... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect. ...

Method and apparatus for assessing material properties of sheet-like materials

DOEpatents

Telschow, Kenneth L.; Deason, Vance A.

2002-01-01

Apparatus for producing an indication of a material property of a sheet-like material according to the present invention may comprise an excitation source for vibrating the sheet-like material to produce at least one traveling wave therein. A light source configured to produce an object wavefront and a reference wavefront directs the object wavefront toward the sheet-like material to produce a modulated object wavefront. A modulator operatively associated with the reference wavefront modulates the reference wavefront in synchronization with the traveling wave on the sheet-like material to produce a modulated reference wavefront. A sensing medium positioned to receive the modulated object wavefront and the modulated reference wavefront produces an image of the traveling wave in the sheet-like material, the image of the anti-symmetric traveling wave being related to a displacement amplitude of the anti-symmetric traveling wave over a two-dimensional area of the vibrating sheet-like material. A detector detects the image of the traveling wave in the sheet-like material.

Stability of Thin Liquid Sheet Flows

NASA Technical Reports Server (NTRS)

McConley, Marc W.; Chubb, Donald L.; McMaster, Matthew S.; Afjeh, Abdollah A.

1997-01-01

A two-dimensional, linear stability analysis of a thin nonplanar liquid sheet flow in vacuum is carried out. A sheet flow created by a narrow slit of W and tau attains a nonplanar cross section as a consequence of cylinders forming on the sheet edge under the influence of surface tension forces. The region where these edge cylinders join the sheet is one of high curvature, and this is found to be the location where instability is most likely to occur. The sheet flow is found to be unstable, but with low growth rates for symmetric wave disturbances and high growth rates for antisymmetric disturbances. By combining the symmetric and antisymmetric disturbance modes, a wide range of stability characteristics is obtained. The product of unstable growth rate and flow time is proportional to the width-to-thickness ratio of the sift generating the sheet Three-dimensional effects can alter these results, particularly when the sheet length-to-width ratio is not much greater than unity.

Research on Al-alloy sheet forming formability during warm/hot sheet hydroforming based on elliptical warm bulging test

NASA Astrophysics Data System (ADS)

Cai, Gaoshen; Wu, Chuanyu; Gao, Zepu; Lang, Lihui; Alexandrov, Sergei

2018-05-01

An elliptical warm/hot sheet bulging test under different temperatures and pressure rates was carried out to predict Al-alloy sheet forming limit during warm/hot sheet hydroforming. Using relevant formulas of ultimate strain to calculate and dispose experimental data, forming limit curves (FLCS) in tension-tension state of strain (TTSS) area are obtained. Combining with the basic experimental data obtained by uniaxial tensile test under the equivalent condition with bulging test, complete forming limit diagrams (FLDS) of Al-alloy are established. Using a quadratic polynomial curve fitting method, material constants of fitting function are calculated and a prediction model equation for sheet metal forming limit is established, by which the corresponding forming limit curves in TTSS area can be obtained. The bulging test and fitting results indicated that the sheet metal FLCS obtained were very accurate. Also, the model equation can be used to instruct warm/hot sheet bulging test.

The Promiscuity of [beta]-Strand Pairing Allows for Rational Design of [beta]-Sheet Face Inversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makabe, Koki; Koide, Shohei

2009-06-17

Recent studies suggest the dominant role of main-chain H-bond formation in specifying {beta}-sheet topology. Its essentially sequence-independent nature implies a large degree of freedom in designing {beta}-sheet-based nanomaterials. Here we show rational design of {beta}-sheet face inversions by incremental deletions of {beta}-strands from the single-layer {beta}-sheet of Borrelia outer surface protein A. We show that a {beta}-sheet structure can be maintained when a large number of native contacts are removed and that one can design large-scale conformational transitions of a {beta}-sheet such as face inversion by exploiting the promiscuity of strand-strand interactions. High-resolution X-ray crystal structures confirmed the success ofmore » the design and supported the importance of main-chain H-bonds in determining {beta}-sheet topology. This work suggests a simple but effective strategy for designing and controlling nanomaterials based on {beta}-rich peptide self-assemblies.« less

Experimental realization of two-dimensional boron sheets

NASA Astrophysics Data System (ADS)

Feng, Baojie; Zhang, Jin; Zhong, Qing; Li, Wenbin; Li, Shuai; Li, Hui; Cheng, Peng; Meng, Sheng; Chen, Lan; Wu, Kehui

2016-06-01

A variety of two-dimensional materials have been reported in recent years, yet single-element systems such as graphene and black phosphorus have remained rare. Boron analogues have been predicted, as boron atoms possess a short covalent radius and the flexibility to adopt sp2 hybridization, features that favour the formation of two-dimensional allotropes, and one example of such a borophene material has been reported recently. Here, we present a parallel experimental work showing that two-dimensional boron sheets can be grown epitaxially on a Ag(111) substrate. Two types of boron sheet, a β12 sheet and a χ3 sheet, both exhibiting a triangular lattice but with different arrangements of periodic holes, are observed by scanning tunnelling microscopy. Density functional theory simulations agree well with experiments, and indicate that both sheets are planar without obvious vertical undulations. The boron sheets are quite inert to oxidization and interact only weakly with their substrate. We envisage that such boron sheets may find applications in electronic devices in the future.

Enhanced ice sheet melting driven by volcanic eruptions during the last deglaciation.

PubMed

Muschitiello, Francesco; Pausata, Francesco S R; Lea, James M; Mair, Douglas W F; Wohlfarth, Barbara

2017-10-24

Volcanic eruptions can impact the mass balance of ice sheets through changes in climate and the radiative properties of the ice. Yet, empirical evidence highlighting the sensitivity of ancient ice sheets to volcanism is scarce. Here we present an exceptionally well-dated annual glacial varve chronology recording the melting history of the Fennoscandian Ice Sheet at the end of the last deglaciation (∼13,200-12,000 years ago). Our data indicate that abrupt ice melting events coincide with volcanogenic aerosol emissions recorded in Greenland ice cores. We suggest that enhanced ice sheet runoff is primarily associated with albedo effects due to deposition of ash sourced from high-latitude volcanic eruptions. Climate and snowpack mass-balance simulations show evidence for enhanced ice sheet runoff under volcanically forced conditions despite atmospheric cooling. The sensitivity of past ice sheets to volcanic ashfall highlights the need for an accurate coupling between atmosphere and ice sheet components in climate models.

ISEE-1 and 2 observations of field-aligned currents in the distant midnight magnetosphere

NASA Technical Reports Server (NTRS)

Elphic, R. C.; Kelly, T. J.; Russell, C. T.

1985-01-01

Magnetic field measurements obtained in the nightside magnetosphere by the co-orbiting ISEE-1 and 2 spacecraft have been examined for signatures of field-aligned currents (FAC). Such currents are found on the boundary of the plasma sheet both when the plasma sheet is expanding and when it is thinning. Evidence is often found for the existence of waves on the plasma sheet boundary, leading to multiple crossings of the FAC sheet. At times the boundary layer FAC sheet orientation is nearly parallel to the X-Z GSM plane, suggesting 'protrusions' of plasma sheet into the lobes. The boundary layer current polarity is, as expected, into the ionosphere in the midnight to dawn local time sector, and outward near dusk. Current sheet thicknesses and velocities are essentially independent of plasma sheet expansion or thinning, having typical values of 1500 km and 20-40 km/s respectively. Characteristic boundary layer current densities are about 10 nanoamps per square meter.

A Transient Initialization Routine of the Community Ice Sheet Model for the Greenland Ice Sheet

NASA Astrophysics Data System (ADS)

van der Laan, Larissa; van den Broeke, Michiel; Noël, Brice; van de Wal, Roderik

2017-04-01

The Community Ice Sheet Model (CISM) is to be applied in future simulations of the Greenland Ice Sheet under a range of climate change scenarios, determining the sensitivity of the ice sheet to individual climatic forcings. In order to achieve reliable results regarding ice sheet stability and assess the probability of future occurrence of tipping points, a realistic initial ice sheet geometry is essential. The current work describes and evaluates the development of a transient initialization routine, using NGRIP 18O isotope data to create a temperature anomaly field. Based on the latter, surface mass balance components runoff and precipitation are perturbed for the past 125k years. The precipitation and runoff fields originate from a downscaled 1 km resolution version of the regional climate model RACMO2.3 for the period 1961-1990. The result of the initialization routine is a present-day ice sheet with a transient memory of the last glacial-interglacial cycle, which will serve as the future runs' initial condition.

[Early prenatal interview: implementation of a sheet link "carried" by patient. The Aurore perinatal network experience].

PubMed

Dupont, C; Gonnaud, F; Touzet, S; Luciani, F; Perié, M-A; Molenat, F; Evrard, A; Fernandez, M-P; Roy, J; Rudigoz, R-C

2008-11-01

Early prenatal interview has needed the implementation of a new communication tool between follow-up pregnancy professionals: a link sheet filled and carried by patients. To assess the utilization of link sheet by trained professionals, the contribution of the interview and the patient acceptation of the link sheet. Descriptive survey from the database of link sheets returned by professionals to Aurore perinatal network and semi-guided interviews with 100 randomized patients. One thousand one hundred and nineteen link sheets were sent to Aurore perinatal network by 55 professionals out of 78 trained. For primipare, precocious prenatal interview contribution has concerned health care security (60%) and emotional security (56%). For multipare, this contribution has concerned mainly emotional security (80%). No interviewed patient has refused link sheet principle. Link sheet principle, like implemented by Aurore perinatal network, seems pertinent to professionals and patients but it constitutes only one of the elements of network elaboration of personalized care.

Supercritical fluid extraction of bi & multi-layer graphene sheets from graphite by using exfoliation technique

NASA Astrophysics Data System (ADS)

Xavier, Gauravi; Dave, Bhoomi; Khanna, Sakshum

2018-05-01

In recent times, researchers have turned to explore the possibility of using Supercritical Fluid (SCFs) system to penetrate into the inert-gaping of graphite and exfoliate it into a number of layer graphene sheets. The supercritical fluid holds excellent wetting surfaces with low interfacial tension and high diffusion coefficients. Although SCFs exfoliation approach looks promising to developed large scale & low-cost graphene sheet but has not received much attention. To arouse interest and reflection on this approach, this review is organized to summarize the recent progress in graphene production by SCF technology. Here we present the simplest route to obtained layers of graphene sheets by intercalating and exfoliating graphite using supercritical CO2 processing. The layers graphene nano-sheets were collected in dichloromethane (DCM) solution which prevents the restocking of sheets. The obtained graphene sheets show the desired characteristics and thus can be used in physical, chemical and biological sciences. Thus this method provides an effortless and eco-friendly approach for the synthesis of layers of graphene sheets.

Polar ice-sheet contributions to sea level during past warm periods

NASA Astrophysics Data System (ADS)

Dutton, A.

2015-12-01

Recent sea-level rise has been dominated by thermal expansion and glacier loss, but the contribution from mass loss from the Greenland and Antarctic ice sheets is expected to exceed other contributions under future sustained warming. Due to limitations of existing ice sheet models and the lack of relevant analogues in the historical record, projecting the timing and magnitude of polar ice sheet mass loss in the future remains challenging. One approach to improving our understanding of how polar ice-sheet retreat will unfold is to integrate observations and models of sea level, ice sheets, and climate during past intervals of warmth when the polar ice sheets contributed to higher sea levels. A recent review evaluated the evidence of polar ice sheet mass loss during several warm periods, including interglacials during the mid-Pliocene warm period, Marine Isotope Stage (MIS) 11, 5e (Last Interglacial), and 1 (Holocene). Sea-level benchmarks of ice-sheet retreat during the first of these three periods, when global mean climate was ~1 to 3 deg. C warmer than preindustrial, are useful for understanding the long-term potential for future sea-level rise. Despite existing uncertainties in these reconstructions, it is clear that our present climate is warming to a level associated with significant polar ice-sheet loss in the past, resulting in a conservative estimate for a global mean sea-level rise of 6 meters above present (or more). This presentation will focus on identifying the approaches that have yielded significant advances in terms of past sea level and ice sheet reconstruction as well as outstanding challenges. A key element of recent advances in sea-level reconstructions is the ability to recognize and quantify the imprint of geophysical processes, such as glacial isostatic adjustment (GIA) and dynamic topography, that lead to significant spatial variability in sea level reconstructions. Identifying specific ice-sheet sources that contributed to higher sea levels is a challenge that is currently hindered by limited field evidence at high latitudes. Finally, I will explore the concept of how increasing the quantity and quality of paleo sea level and ice sheet reconstructions can lead to improved quantification of contemporary changes in ice sheets and sea level.

An elastic analysis of stresses in a uniaxially loaded sheet containing an interference-fit bolt

NASA Technical Reports Server (NTRS)

Crews, J. H., Jr.

1972-01-01

The stresses in a sheet with an interference-fit bolt have been calculated for two sheet-bolt interface conditions: a frictionless interface and a fixed (no-slip) interface. The stress distributions were calculated for various combinations of sheet and bolt moduli. The results show that for repeated loading the local stress range is significantly smaller if an interference bolt is used instead of a loosely fitting one. This reduction in local stress range is more pronounced when the ratio of bolt modulus to sheet modulus is large. The analysis also indicates that currently used standard values of interference cause yielding in the sheet.

Calculations of axisymmetric vortex sheet roll-up using a panel and a filament model

NASA Technical Reports Server (NTRS)

Kantelis, J. P.; Widnall, S. E.

1986-01-01

A method for calculating the self-induced motion of a vortex sheet using discrete vortex elements is presented. Vortex panels and vortex filaments are used to simulate two-dimensional and axisymmetric vortex sheet roll-up. A straight forward application using vortex elements to simulate the motion of a disk of vorticity with an elliptic circulation distribution yields unsatisfactroy results where the vortex elements move in a chaotic manner. The difficulty is assumed to be due to the inability of a finite number of discrete vortex elements to model the singularity at the sheet edge and due to large velocity calculation errors which result from uneven sheet stretching. A model of the inner portion of the spiral is introduced to eliminate the difficulty with the sheet edge singularity. The model replaces the outermost portion of the sheet with a single vortex of equivalent circulation and a number of higher order terms which account for the asymmetry of the spiral. The resulting discrete vortex model is applied to both two-dimensional and axisymmetric sheets. The two-dimensional roll-up is compared to the solution for a semi-infinite sheet with good results.

Silicone sheet containing all-trans retinoic acid and hydroquinone for the treatment of epidermal melanosis.

PubMed

Iida, Shoko; Takushima, Akihiko; Ohura, Norihiko; Sato, Suguru; Kurita, Masakazu; Harii, Kiyonori

2013-08-01

Although bleaching treatment using all-trans retinoic acid (RA) and hydroquinone (HQ) improves epidermal melanosis, the application of two medications and the irritant dermatitis induced by RA inconvenience patients. To overcome these problems, we developed a silicone sheet containing RA and HQ. To compare the efficacy of a silicone sheet containing RA and HQ with that of conventional bleaching treatment. Silicone sheets containing 1% RA and 5% HQ were applied at night during the bleaching phase of 4 weeks, followed by application of sheets containing 5% HQ during the healing phase of 4 weeks. Hemifacial epidermal melanosis, for which the sheets were applied, was compared with a contralateral face which was treated conventionally using RA and HQ. Twenty-four Japanese women who were enrolled in this study and followed up for more than 6 months were analyzed. RA/HQ sheets improved epidermal melanosis, as did the conventional bleaching method, but irritant dermatitis occurred less in patients treated using silicone sheets. RA/HQ sheets, which are easily applied to face skin, can improve epidermal melanosis to the same extent as conventional bleaching. © 2013 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

Spiral wound extraction cartridge

DOEpatents

Wisted, E.E.; Lundquist, S.H.

1999-04-27

A cartridge device for removing an analyte from a fluid comprises a hollow core, a sheet composite comprising a particulate-loaded porous membrane and optionally at least one reinforcing spacer sheet, the particulate being capable of binding the analyte, the sheet composite being formed into a spiral configuration about the core, wherein the sheet composite is wound around itself and wherein the windings of sheet composite are of sufficient tightness so that adjacent layers are essentially free of spaces therebetween, two end caps which are disposed over the core and the lateral ends of the spirally wound sheet composite, and means for securing the end caps to the core, the end caps also being secured to the lateral ends of the spirally wound sheet composite. A method for removing an analyte from a fluid comprises the steps of providing a spirally wound element of the invention and passing the fluid containing the analyte through the element essentially normal to a surface of the sheet composite so as to bind the analyte to the particulate of the particulate-loaded porous membrane, the method optionally including the step of eluting the bound analyte from the sheet composite. 4 figs.

Structure and Dynamics of Current Sheets in 3D Magnetic Fields with the X-line

NASA Astrophysics Data System (ADS)

Frank, Anna G.; Bogdanov, S. Yu.; Bugrov, S. G.; Markov, V. S.; Dreiden, G. V.; Ostrovskaya, G. V.

2004-11-01

Experimental results are presented on the structure of current sheets formed in 3D magnetic fields with singular lines of the X-type. Two basic diagnostics were used with the device CS - 3D: two-exposure holographic interferometry and magnetic measurements. Formation of extended current sheets and plasma compression were observed in the presence of the longitudinal magnetic field component aligned with the X-line. Plasma density decreased and the sheet thickness increased with an increase of the longitudinal component. We succeeded to reveal formation of the sheets taking unusual shape, namely tilted and asymmetric sheets, in plasmas with the heavy ions. These current sheets were obviously different from the planar sheets formed in 2D magnetic fields, i.e. without longitudinal component. Analysis of typical plasma parameters made it evident that plasma dynamics and current sheet evolution should be treated on the base of the two-fluid approach. Specifically it is necessary to take into account the Hall currents in the plane perpendicular to the X-line, and the dynamic effects resulting from interaction of the Hall currents and the 3D magnetic field. Supported by RFBR, grant 03-02-17282, and ISTC, project 2098.

Results of the Greenland Ice Sheet Model Initialisation Experiments ISMIP6 - initMIP-Greenland

NASA Astrophysics Data System (ADS)

Goelzer, H.; Nowicki, S.; Edwards, T.; Beckley, M.; Abe-Ouchi, A.; Aschwanden, A.; Calov, R.; Gagliardini, O.; Gillet-chaulet, F.; Golledge, N. R.; Gregory, J. M.; Greve, R.; Humbert, A.; Huybrechts, P.; Larour, E. Y.; Lipscomb, W. H.; Le ´h, S.; Lee, V.; Kennedy, J. H.; Pattyn, F.; Payne, A. J.; Rodehacke, C. B.; Rückamp, M.; Saito, F.; Schlegel, N.; Seroussi, H. L.; Shepherd, A.; Sun, S.; Vandewal, R.; Ziemen, F. A.

2016-12-01

Earlier large-scale Greenland ice sheet sea-level projections e.g. those run during ice2sea and SeaRISE initiatives have shown that ice sheet initialisation can have a large effect on the projections and gives rise to important uncertainties. The goal of this intercomparison exercise (initMIP-Greenland) is to compare, evaluate and improve the initialization techniques used in the ice sheet modeling community and to estimate the associated uncertainties. It is the first in a series of ice sheet model intercomparison activities within ISMIP6 (Ice Sheet Model Intercomparison Project for CMIP6). Two experiments for the large-scale Greenland ice sheet have been designed to allow intercomparison between participating models of 1) the initial present-day state of the ice sheet and 2) the response in two schematic forward experiments. The forward experiments serve to evaluate the initialisation in terms of model drift (forward run without any forcing) and response to a large perturbation (prescribed surface mass balance anomaly). We present and discuss final results of the intercomparison and highlight important uncertainties with respect to projections of the Greenland ice sheet sea-level contribution.

Laser Indirect Shock Welding of Fine Wire to Metal Sheet.

PubMed

Wang, Xiao; Huang, Tao; Luo, Yapeng; Liu, Huixia

2017-09-12

The purpose of this paper is to present an advanced method for welding fine wire to metal sheet, namely laser indirect shock welding (LISW). This process uses silica gel as driver sheet to accelerate the metal sheet toward the wire to obtain metallurgical bonding. A series of experiments were implemented to validate the welding ability of Al sheet/Cu wire and Al sheet/Ag wire. It was found that the use of a driver sheet can maintain high surface quality of the metal sheet. With the increase of laser pulse energy, the bonding area of the sheet/wire increased and the welding interfaces were nearly flat. Energy dispersive spectroscopy (EDS) results show that the intermetallic phases were absent and a short element diffusion layer which would limit the formation of the intermetallic phases emerging at the welding interface. A tensile shear test was used to measure the mechanical strength of the welding joints. The influence of laser pulse energy on the tensile failure modes was investigated, and two failure modes, including interfacial failure and failure through the wire, were observed. The nanoindentation test results indicate that as the distance to the welding interface decreased, the microhardness increased due to the plastic deformation becoming more violent.

Thermal properties of highly structured composite and aluminium sheets in an aerodynamic tunnel

NASA Astrophysics Data System (ADS)

Kulhavy, Petr; Egert, Josef

This article deals with the thermodynamic behaviour of heat shields - structured metal and composite plates. Experiments have been carried out in a wind tunnel with an additional heating, which simulates the heat source from engine or exhaust pipe and simultaneously the airflow generated during a car movement. The tested sheets with hexagonal structure were a standard commercial made of aluminium and a second manufactured by replication (lamination, diffusion) from glass fabric. The airflow in a parallel way along the sheets was analysed experimentally in order to determine the heat transfer efficiency between surfaces of sheets and surrounding airflow. The temperature on the sheets was chosen to observe the effects of different sheets material, various heat power and airflow velocity. During the experiment a thermal input below the sheets and airflow velocity through the tunnel have been changed. The thermal field distribution on the metal sheet is different than in case of composite sheet. For the composite material the thermal field distribution was more homogeneous. This article describe briefly also methods of obtaining real composite geometry based on scanned data and their reconstruction for using in some future numerical models.

Rapid fabricating technique for multi-layered human hepatic cell sheets by forceful contraction of the fibroblast monolayer.

PubMed

Sakai, Yusuke; Koike, Makiko; Hasegawa, Hideko; Yamanouchi, Kosho; Soyama, Akihiko; Takatsuki, Mitsuhisa; Kuroki, Tamotsu; Ohashi, Kazuo; Okano, Teruo; Eguchi, Susumu

2013-01-01

Cell sheet engineering is attracting attention from investigators in various fields, from basic research scientists to clinicians focused on regenerative medicine. However, hepatocytes have a limited proliferation potential in vitro, and it generally takes a several days to form a sheet morphology and multi-layered sheets. We herein report our rapid and efficient technique for generating multi-layered human hepatic cell (HepaRG® cell) sheets using pre-cultured fibroblast monolayers derived from human skin (TIG-118 cells) as a feeder layer on a temperature-responsive culture dish. Multi-layered TIG-118/HepaRG cell sheets with a thick morphology were harvested on day 4 of culturing HepaRG cells by forceful contraction of the TIG-118 cells, and the resulting sheet could be easily handled. In addition, the human albumin and alpha 1-antitrypsin synthesis activities of TIG-118/HepaRG cells were approximately 1.2 and 1.3 times higher than those of HepaRG cells, respectively. Therefore, this technique is considered to be a promising modality for rapidly fabricating multi-layered human hepatocyte sheets from cells with limited proliferation potential, and the engineered cell sheet could be used for cell transplantation with highly specific functions.

Widespread Refreezing of Both Surface and Basal Melt Water Beneath the Greenland Ice Sheet

NASA Astrophysics Data System (ADS)

Bell, R. E.; Tinto, K. J.; Das, I.; Wolovick, M.; Chu, W.; Creyts, T. T.; Frearson, N.

2013-12-01

The isotopically and chemically distinct, bubble-free ice observed along the Greenland Ice Sheet margin both in the Russell Glacier and north of Jacobshavn must have formed when water froze from subglacial networks. Where this refreezing occurs and what impact it has on ice sheet processes remain unclear. We use airborne radar data to demonstrate that freeze-on to the ice sheet base and associated deformation produce large ice units up to 700 m thick throughout northern Greenland. Along the ice sheet margin, in the ablation zone, surface meltwater, delivered via moulins, refreezes to the ice sheet base over rugged topography. In the interior, water melted from the ice sheet base is refrozen and surrounded by folded ice. A significant fraction of the ice sheet is modified by basal freeze-on and associated deformation. For the Eqip and Petermann catchments, representing the ice sheet margin and interior respectively, extensive airborne radar datasets show that 10%-13% of the base of the ice sheet and up to a third of the catchment width is modified by basal freeze-on. The interior units develop over relatively subdued topography with modest water flux from basal melt where conductive cooling likely dominates. Steps in the bed topography associated with subglacial valley networks may foster glaciohydraulic supercooling. The ablation zone units develop where both surface melt and crevassing are widespread and large volumes of surface meltwater will reach the base of the ice sheet. The relatively steep topography at the upslope edge of the ablation zone units combined with the larger water flux suggests that supercooling plays a greater role in their formation. The ice qualities of the ablation zone units should reflect the relatively fresh surface melt whereas the chemistry of the interior units should reflect solute-rich basal melt. Changes in basal conditions such as the presence of till patches may contribute to the formation of the large basal units near the Northeast Ice Stream. The contrasting rheology of glacial and interglacial ice may also enhance the deformation associated with freeze-on beneath large ice sheets. The occurrence of basal units both in the ice sheet interior and in the thermally very different ablation zone indicates refreezing is widespread and can occur in many environments beneath an ice sheet. This process appears to influence the morphology and behavior of the ice sheet from top to bottom.

Reconstructing the last Irish Ice Sheet 2: a geomorphologically-driven model of ice sheet growth, retreat and dynamics

NASA Astrophysics Data System (ADS)

Greenwood, Sarah L.; Clark, Chris D.

2009-12-01

The ice sheet that once covered Ireland has a long history of investigation. Much prior work focussed on localised evidence-based reconstructions and ice-marginal dynamics and chronologies, with less attention paid to an ice sheet wide view of the first order properties of the ice sheet: centres of mass, ice divide structure, ice flow geometry and behaviour and changes thereof. In this paper we focus on the latter aspect and use our new, countrywide glacial geomorphological mapping of the Irish landscape (>39 000 landforms), and our analysis of the palaeo-glaciological significance of observed landform assemblages (article Part 1), to build an ice sheet reconstruction yielding these fundamental ice sheet properties. We present a seven stage model of ice sheet evolution, from initiation to demise, in the form of palaeo-geographic maps. An early incursion of ice from Scotland likely coalesced with local ice caps and spread in a south-westerly direction 200 km across Ireland. A semi-independent Irish Ice Sheet was then established during ice sheet growth, with a branching ice divide structure whose main axis migrated up to 140 km from the west coast towards the east. Ice stream systems converging on Donegal Bay in the west and funnelling through the North Channel and Irish Sea Basin in the east emerge as major flow components of the maximum stages of glaciation. Ice cover is reconstructed as extending to the continental shelf break. The Irish Ice Sheet became autonomous (i.e. separate from the British Ice Sheet) during deglaciation and fragmented into multiple ice masses, each decaying towards the west. Final sites of demise were likely over the mountains of Donegal, Leitrim and Connemara. Patterns of growth and decay of the ice sheet are shown to be radically different: asynchronous and asymmetric in both spatial and temporal domains. We implicate collapse of the ice stream system in the North Channel - Irish Sea Basin in driving such asymmetry, since rapid collapse would sever the ties between the British and Irish Ice Sheets and drive flow configuration changes in response. Enhanced calving and flow acceleration in response to rising relative sea level is speculated to have undermined the integrity of the ice stream system, precipitating its collapse and driving the reconstructed pattern of ice sheet evolution.

Construction of osteochondral-like tissue graft combining β-tricalcium phosphate block and scaffold-free centrifuged chondrocyte cell sheet.

PubMed

Niyama, Kouhei; Ide, Naoto; Onoue, Kaori; Okabe, Takahiro; Wakitani, Shigeyuki; Takagi, Mutsumi

2011-09-01

The combination of a β-tricalcium phosphate (βTCP) block with a scaffold-free chondrocyte sheet formed by the centrifugation of chondrocytes in a well was investigated with the aim of constructing an osteochondral-like structure. Human and porcine articular cartilage chondrocytes were respectively centrifuged in a 96-well plate or cell culture insert (0.32 cm(2)) that was set in a 24-well plate, cultivated in the respective vessel for 3 weeks, and the cell sheets were harvested. In some cases, a cylindrical βTCP block (diameter 5 mm, height 3 mm) was placed on the sheet on days 1-7. The sheet size, cell number, and sulfated glycosaminoglycan accumulation were determined. The use of a 96-well plate for not suspension but adhesion culture and the initial centrifugation of a well containing cells were crucial to obtaining a uniformly thick cell sheet. The glycosaminoglycan density of the harvested cell sheet was comparable to that of the pellet culture. An inoculum cell number of more than 31 × 10(5) cells tended to result in a curved cell sheet. Culture involving 18.6 × 10(5) cells and the 96-well plate for adhesion culture showed no curving of the cell sheet (thickness of 0.85 mm), and these were found to be the best of the culture conditions tested. The timing of the addition of a βTCP block to the cell sheet (1-7 days) markedly affected the balance between the thickness of cell sheet parts on and in the βTCP block. Centrifugation and subsequent cultivation of chondrocytes (18.6 × 10(5) cells) in a 96-well plate for adhesion culture led to the production of a scaffold-free cartilage-like cell sheet with a thickness of 0.85 mm. A combined osteochondral-like structure was produced by putting a βTCP block on the cell sheet. The thickness of the cell sheet on the βTCP block and the binding strength between the cell sheet and the βTCP block could be optimized by adjusting the inoculum cell number and timing of βTCP block addition.

Spectroscopic studies on the conformational transitions of a bovine growth hormone releasing factor analog

NASA Astrophysics Data System (ADS)

Sarver, Ronald W.; Friedman, Alan R.; Thamann, Thomas J.

1997-10-01

The secondary structure of the bovine growth hormone releasing factor analog, [Ile 2, Ser 8,28, Ala 15, Leu 27, Hse 30] bGRF(1-30)-NH-Ethyl, acetate salt (U-90699F) was studied in solution by Fourier transform infrared and Raman spectroscopies. Spectroscopic studies revealed that concentrated aqueous solutions of U-90699F (100 mg ml -1) undergo a secondary structure transition from disordered coil/α-helix to intermolecular β-sheet. Disordered coil and α-helical structure were grouped together in the infrared and Raman studies since the amide I vibrations are close in frequency and overlap in assignments was possible. Before the conformational transition, the facile exchange of the peptide's amide hydrogens for deuterium indicated that the majority of amide hydrogens were readily accessible to solvent. The kinetics of the conformational transition coincided with an increase in solution viscosity and turbidity. An initiation phase preceded the conformational transition during which only minor spectral changes were observed by infrared spectroscopy. The initiation phase and reaction kinetics were consistent with a highly cooperative nucleation ultimately leading to a network of intermolecular β-sheet structure and gel formation. Increased temperature accelerated the conformational transition. The conformational transition was thermally irreversible but the β-sheet structure of aggregated or gelled peptide could be disrupted by dilution and agitation.

Image Classification of Ribbed Smoked Sheet using Learning Vector Quantization

NASA Astrophysics Data System (ADS)

Rahmat, R. F.; Pulungan, A. F.; Faza, S.; Budiarto, R.

2017-01-01

Natural rubber is an important export commodity in Indonesia, which can be a major contributor to national economic development. One type of rubber used as rubber material exports is Ribbed Smoked Sheet (RSS). The quantity of RSS exports depends on the quality of RSS. RSS rubber quality has been assigned in SNI 06-001-1987 and the International Standards of Quality and Packing for Natural Rubber Grades (The Green Book). The determination of RSS quality is also known as the sorting process. In the rubber factones, the sorting process is still done manually by looking and detecting at the levels of air bubbles on the surface of the rubber sheet by naked eyes so that the result is subjective and not so good. Therefore, a method is required to classify RSS rubber automatically and precisely. We propose some image processing techniques for the pre-processing, zoning method for feature extraction and Learning Vector Quantization (LVQ) method for classifying RSS rubber into two grades, namely RSS1 and RSS3. We used 120 RSS images as training dataset and 60 RSS images as testing dataset. The result shows that our proposed method can give 89% of accuracy and the best perform epoch is in the fifteenth epoch.

Rainfall and sheet power equation for interrill erosion on steep hillslope

USDA-ARS?s Scientific Manuscript database

Splash and sheet erosion processes dominate on most undisturbed hillslopes of rangeland. Interrill soil erosion should consider the influence of both raindrop and sheet flow to work of soil particles detached by raindrop impact and transported by rainfall-disturbed sheet flow. Interrill erosion equa...

47 CFR 32.3999 - Instructions for balance sheet accounts-liabilities and stockholders' equity.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Instructions for balance sheet accounts-liabilities and stockholders' equity. 32.3999 Section 32.3999 Telecommunication FEDERAL COMMUNICATIONS... Instructions for Balance Sheet Accounts § 32.3999 Instructions for balance sheet accounts—liabilities and...

47 CFR 32.3999 - Instructions for balance sheet accounts-liabilities and stockholders' equity.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 2 2011-10-01 2011-10-01 false Instructions for balance sheet accounts-liabilities and stockholders' equity. 32.3999 Section 32.3999 Telecommunication FEDERAL COMMUNICATIONS... Instructions for Balance Sheet Accounts § 32.3999 Instructions for balance sheet accounts—liabilities and...

From Tragedy to Triumph - Rebuilding Green Homes after Disaster (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2009-04-01

Energy Efficiency/Renewable Energy Fact Sheets, No. 1. Series to include practical, useful info to help people change their behavior around energy usage and "greenness". Greensburg is hanging its future on sustainable development; these fact sheet sheets should help citizens understand what they can do to be a part of that focus. Fact Sheets cover: saving energy and water, using renewable energy (particular interest in small wind), driving "green", general sustainability, living green.

Residual stress measurement in silicon sheet by shadow moire interferometry

NASA Technical Reports Server (NTRS)

Kwon, Y.; Danyluk, S.; Bucciarelli, L.; Kalejs, J. P.

1987-01-01

A shadow moire interferometry technique has been developed to measure residual strain in thin silicon sheet. The curvature of a segment of sheet undergoing four-point bending is analyzed to include the applied bending moments, the in-plane residual stresses, and the 'end effect' of the sheet since it is of finite length. The technique is applied to obtain residual stress distributions for silicon sheet grown by the edge-defined film-fed growth technique.

Hypsometric amplification and routing moderation of Greenland ice sheet meltwater release

NASA Astrophysics Data System (ADS)

van As, Dirk; Mikkelsen, Andreas Bech; Holtegaard Nielsen, Morten; Box, Jason E.; Claesson Liljedahl, Lillemor; Lindbäck, Katrin; Pitcher, Lincoln; Hasholt, Bent

2017-06-01

Concurrent ice sheet surface runoff and proglacial discharge monitoring are essential for understanding Greenland ice sheet meltwater release. We use an updated, well-constrained river discharge time series from the Watson River in southwest Greenland, with an accurate, observation-based ice sheet surface mass balance model of the ˜ 12 000 km2 ice sheet area feeding the river. For the 2006-2015 decade, we find a large range of a factor of 3 in interannual variability in discharge. The amount of discharge is amplified ˜ 56 % by the ice sheet's hypsometry, i.e., area increase with elevation. A good match between river discharge and ice sheet surface meltwater production is found after introducing elevation-dependent transit delays that moderate diurnal variability in meltwater release by a factor of 10-20. The routing lag time increases with ice sheet elevation and attains values in excess of 1 week for the upper reaches of the runoff area at ˜ 1800 m above sea level. These multi-day routing delays ensure that the highest proglacial discharge levels and thus overbank flooding events are more likely to occur after multi-day melt episodes. Finally, for the Watson River ice sheet catchment, we find no evidence of meltwater storage in or release from the en- and subglacial environments in quantities exceeding our methodological uncertainty, based on the good match between ice sheet runoff and proglacial discharge.

A comprehensive study of the electrically conducting water based CuO and Al2O3 nanoparticles over coupled nanofluid-sheet interface

NASA Astrophysics Data System (ADS)

Ahmad, R.

2016-02-01

Many studies on nanofluid flow over a permeable/impermeable sheet prescribe the kinematics of the sheet and disregard the sheet’s mechanics. However, the current study is one of the infrequent contributions that anticipate the mechanics of both the electrically conducting nanofluid (a homogeneous mixture of nanoparticles and base fluid) and the sheet. Two types of nanoparticles, alumina and copper, with water as a base fluid over the sheet are considered. With the help of the similarity transformations, the corresponding partial differential equations for the coupled nanofluid-sheet interface are transformed into a system of ordinary differential equations. The simulations are done by using the experimentally verified results from the previous studies for viscosity and thermal conductivity. Self-similar solutions are attained by considering both analytical and numerical techniques. Dual skin friction coefficients are attained with different copper and alumina nanoparticles over both the stretching and viscous sheets. The influence of the Eckert number, magnetic and mass suction/blowing parameters on the dimensionless velocity, temperature, skin friction and heat transfer rates over the nanofluid-sheet interface are presented graphically as well as numerically. The obtained results are of potential benefit for studying nanofluid flow over various soft surfaces such as synthetic plastics, soft silicone sheet and soft synthetic rubber sheet. These surfaces are easily deformed by thermal fluctuations.

A flexible tactile sensitive sheet using a hetero-core fiber optic sensor

NASA Astrophysics Data System (ADS)

Fujino, S.; Yamazaki, H.; Hosoki, A.; Watanabe, K.

2014-05-01

In this report, we have designed a tactile sensitive sheet based on a hetero-core fiber-optic sensor, which realize an areal sensing by using single sensor potion in one optical fiber line. Recently, flexible and wide-area tactile sensing technology is expected to applied to acquired biological information in living space and robot achieve long-term care services such as welfare and nursing-care and humanoid technology. A hetero-core fiber-optic sensor has several advantages such as thin and flexible transmission line, immunity to EMI. Additionally this sensor is sensitive to moderate bending actions with optical loss changes and is independent of temperature fluctuation. Thus, the hetero-core fiber-optic sensor can be suitable for areal tactile sensing. We measure pressure characteristic of the proposed sensitive sheet by changing the pressure position and pinching characteristic on the surface. The proposed tactile sensitive sheet shows monotonic responses on the whole sensitive sheet surface although different sensitivity by the position is observed at the sensitive sheet surface. Moreover, the tactile sensitive sheet could sufficiently detect the pinching motion. In addition, in order to realize the discrimination between pressure and pinch, we fabricated a doubled-over sensor using a set of tactile sensitive sheets, which has different kinds of silicon robbers as a sensitive sheet surface. In conclusion, the flexible material could be given to the tactile sensation which is attached under proposed sensitive sheet.

Preforming of polydioxanone sheets for orbital wall fractures - A technical note.

PubMed

Kruber, Daniel; Hierl, Thomas; Doerfler, Hans-Martin; Huempfner-Hierl, Heike; Krause, Matthias

2018-07-01

Polydioxanone (PDS) sheets are commonly used in the treatment of orbital wall fractures. A potential drawback of PDS is that it may be difficult to adapt to the anatomy of the orbital walls. Therefore a study was conceived to test the feasibility of preforming PDS sheets. PDS sheet material was water-heated and preformed using a template based on a statistical anatomical model. Then the deformed sheet was cooled, stored and compared to the original model to investigate post-deformation changes. PDS sheet material could easily be deformed using a mould. No significant post-cooling shape changes were noticed. PDS sheet material can be preformed into complex geometric shapes. This could be a benefit in the treatment of orbital wall fractures. Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Osteoblastic mesenchymal stem cell sheet combined with Choukroun platelet-rich fibrin induces bone formation at an ectopic site.

PubMed

Wang, Zhifa; Weng, Yanming; Lu, Shengjun; Zong, Chunlin; Qiu, Jianyong; Liu, Yanpu; Liu, Bin

2015-08-01

To analyze the effects of platelet-rich fibrin (PRF) on mesenchymal stem cells (MSCs) in vitro and investigate in vivo bone formation by MSC sheets with PRF. Cell proliferation and expression of osteogenesis-related genes within MSC sheets were assessed upon exposure to PRF from the same donors. We then injected MSC sheet fragments with or without PRF subcutaneously in nude mice and assessed bone formation by micro-computed tomography and histological analyses. PRF significantly stimulated MSC proliferation and osteogenesis in vitro. MSC sheets injected with or without PRF formed new bone, but those with PRF produced significantly more and denser bone. MSC sheets can be used to generate tissue engineered bone upon injection, and PRF increases the osteogenic capacity of MSC sheets in vitro and in vivo. © 2014 Wiley Periodicals, Inc.

Scanning light-sheet microscopy in the whole mouse brain with HiLo background rejection.

PubMed

Mertz, Jerome; Kim, Jinhyun

2010-01-01

It is well known that light-sheet illumination can enable optically sectioned wide-field imaging of macroscopic samples. However, the optical sectioning capacity of a light-sheet macroscope is undermined by sample-induced scattering or aberrations that broaden the thickness of the sheet illumination. We present a technique to enhance the optical sectioning capacity of a scanning light-sheet microscope by out-of-focus background rejection. The technique, called HiLo microscopy, makes use of two images sequentially acquired with uniform and structured sheet illumination. An optically sectioned image is then synthesized by fusing high and low spatial frequency information from both images. The benefits of combining light-sheet macroscopy and HiLo background rejection are demonstrated in optically cleared whole mouse brain samples, using both green fluorescent protein (GFP)-fluorescence and dark-field scattered light contrast.

Scanning light-sheet microscopy in the whole mouse brain with HiLo background rejection

NASA Astrophysics Data System (ADS)

Mertz, Jerome; Kim, Jinhyun

2010-01-01

It is well known that light-sheet illumination can enable optically sectioned wide-field imaging of macroscopic samples. However, the optical sectioning capacity of a light-sheet macroscope is undermined by sample-induced scattering or aberrations that broaden the thickness of the sheet illumination. We present a technique to enhance the optical sectioning capacity of a scanning light-sheet microscope by out-of-focus background rejection. The technique, called HiLo microscopy, makes use of two images sequentially acquired with uniform and structured sheet illumination. An optically sectioned image is then synthesized by fusing high and low spatial frequency information from both images. The benefits of combining light-sheet macroscopy and HiLo background rejection are demonstrated in optically cleared whole mouse brain samples, using both green fluorescent protein (GFP)-fluorescence and dark-field scattered light contrast.

Experimental analysis of Nd-YAG laser cutting of sheet materials - A review

NASA Astrophysics Data System (ADS)

Sharma, Amit; Yadava, Vinod

2018-01-01

Cutting of sheet material is considered as an important process due to its relevance among products of everyday life such as aircrafts, ships, cars, furniture etc. Among various sheet cutting processes (ASCPs), laser beam cutting is one of the most capable ASCP to create complex geometries with stringent design requirements in difficult-to-cut sheet materials. Based on the recent research work in the area of sheet cutting, it is found that the Nd-YAG laser is used for cutting of sheet material in general and reflective sheet material in particular. This paper reviews the experimental analysis of Nd-YAG laser cutting process, carried out to study the influence of laser cutting parameters on the process performance index. The significance of experimental modeling and different optimization approaches employed by various researchers has also been discussed in this study.

Development of anti-adhesive spongy sheet composed of hyaluronic acid and collagen containing epidermal growth factor.

PubMed

Kuroyanagi, Misato; Yamamoto, Akiko; Shimizu, Nahoko; Toi, Ayako; Inomata, Tomonori; Takeda, Akira; Kuroyanagi, Yoshimitsu

2014-01-01

Anti-adhesive products need to be designed while considering the concept of wound healing. Two main events must proceed simultaneously: facilitating wound healing in surgically excised tissue, as well as preventing injured tissue from adhering to the surrounding tissue. The present study aimed to develop an anti-adhesive spongy sheet composed of hyaluronic acid and collagen (Col) containing epidermal growth factor, and to investigate the potential of this spongy sheet using an in vitro wound surface model (placing a spongy sheet on a fibroblast-incorporating Col gel sheet) and an in vitro inter-tissue model (placing a spongy sheet between two fibroblast-incorporating Col gel sheets). These in vitro experiments demonstrated that this spongy sheet effectively stimulates fibroblasts to release an increased amount of vascular endothelial growth factor and hepatocyte growth factor, which are essential for wound healing to proceed succesfully. In addition, anti-adhesive performance of this spongy sheet was evaluated in animal experiments using Sprague Dawley rats. Under anesthesia, a 1 cm × 2 cm segment of peritoneum was superficially excised from walls, and the cecum was then abraded by scraping with a scalpel blade over a 1 cm × 2 cm area. A piece of spongy sheet was placed on the peritoneal defect. Both defects were placed in contact, and the incision was closed by suturing. Peritoneal condition was evaluated after one week. This spongy sheet was capable of facilitating the wound healing of surgically excised tissue and preventing surgically excised tissue from adhering to surrounding tissues.

Electro-thermo-mechanical coupling analysis of deep drawing with resistance heating for aluminum matrix composites sheet

NASA Astrophysics Data System (ADS)

Zhang, Kaifeng; Zhang, Tuoda; Wang, Bo

2013-05-01

Recently, electro-plastic forming to be a focus of attention in materials hot processing research area, because it is a sort of energy-saving, high efficient and green manufacturing technology. An electro-thermo-mechanical model can be adopted to carry out the sequence simulation of aluminum matrix composites sheet deep drawing via electro-thermal coupling and thermal-mechanical coupling method. The first step of process is resistance heating of sheet, then turn off the power, and the second step is deep drawing. Temperature distribution of SiCp/2024Al composite sheet by resistance heating and sheet deep drawing deformation were analyzed. During the simulation, effect of contact resistances, temperature coefficient of resistance for electrode material and SiCp/2024Al composite on temperature distribution were integrally considered. The simulation results demonstrate that Sicp/2024Al composite sheet can be rapidly heated to 400° in 30s using resistances heating and the sheet temperature can be controlled by adjusting the current density. Physical properties of the electrode materials can significantly affect the composite sheet temperature distribution. The temperature difference between the center and the side of the sheet is proportional to the thermal conductivity of the electrode, the principal cause of which is that the heat transfers from the sheet to the electrode. SiCp/2024Al thin-wall part can be intactly manufactured at strain rate of 0.08s-1 and the sheet thickness thinning rate is limited within 20%, which corresponds well to the experimental result.

Potential subglacial lake locations and meltwater drainage pathways beneath the Antarctic and Greenland ice sheets

NASA Astrophysics Data System (ADS)

Livingstone, S. J.; Clark, C. D.; Woodward, J.; Kingslake, J.

2013-11-01

We use the Shreve hydraulic potential equation as a simplified approach to investigate potential subglacial lake locations and meltwater drainage pathways beneath the Antarctic and Greenland ice sheets. We validate the method by demonstrating its ability to recall the locations of >60% of the known subglacial lakes beneath the Antarctic Ice Sheet. This is despite uncertainty in the ice-sheet bed elevation and our simplified modelling approach. However, we predict many more lakes than are observed. Hence we suggest that thousands of subglacial lakes remain to be found. Applying our technique to the Greenland Ice Sheet, where very few subglacial lakes have so far been observed, recalls 1607 potential lake locations, covering 1.2% of the bed. Our results will therefore provide suitable targets for geophysical surveys aimed at identifying lakes beneath Greenland. We also apply the technique to modelled past ice-sheet configurations and find that during deglaciation both ice sheets likely had more subglacial lakes at their beds. These lakes, inherited from past ice-sheet configurations, would not form under current surface conditions, but are able to persist, suggesting a retreating ice-sheet will have many more subglacial lakes than advancing ones. We also investigate subglacial drainage pathways of the present-day and former Greenland and Antarctic ice sheets. Key sectors of the ice sheets, such as the Siple Coast (Antarctica) and NE Greenland Ice Stream system, are suggested to have been susceptible to subglacial drainage switching. We discuss how our results impact our understanding of meltwater drainage, basal lubrication and ice-stream formation.

A statistical study on the shape and position of the magnetotail neutral sheet

NASA Astrophysics Data System (ADS)

Xiao, Sudong; Zhang, Tielong; Ge, Yasong; Wang, Guoqiang; Baumjohann, Wolfgang; Nakamura, Rumi

2016-02-01

We study the average shape and position of the magnetotail neutral sheet based on magnetic field data obtained by Cluster, Geotail, TC-1, and THEMIS from the years 1995 to 2013. All data in the aberrated GSM (geocentric solar magnetospheric) coordinate system are normalized to the same solar wind pressure 2 nPa and downtail distance X ˜ -20RE. Our results show characteristics of the neutral sheet, as follows. (1) The neutral sheet assumes a greater degree of curve in the YZ cross section when the dipole tilt increases, the Earth dipole tilt angle affects the neutral sheet configuration not only in the YZ cross section but also in the XY cross section, and the neutral sheet assumes a more significant degree of tilt in the XY cross section when the dipole tilt increases. (2) Counterclockwise twisting of the neutral sheet with 3.10° is observed, looking along the downtail direction, for the positive interplanetary magnetic field (IMF) BY with a value of 3 to 8 nT, and clockwise twisting of the neutral sheet with 3.37° for the negative IMF BY with a value of -8 to -3 nT, and a northward IMF can result in a greater twisting of the near-tail neutral sheet than southward. The above results can be a reference to the neutral sheet model. Our large database also shows that the displaced ellipse model is effective to study the average shape of the neutral sheet with proper parameters when the dipole tilt angle is larger (less) than 10° (-10° ).

Glaciological constraints on current ice mass changes from modelling the ice sheets over the glacial cycles

NASA Astrophysics Data System (ADS)

Huybrechts, P.

2003-04-01

The evolution of continental ice sheets introduces a long time scale in the climate system. Large ice sheets have a memory of millenia, hence the present-day ice sheets of Greenland and Antarctica are still adjusting to climatic variations extending back to the last glacial period. This trend is separate from the direct response to mass-balance changes on decadal time scales and needs to be correctly accounted for when assessing current and future contributions to sea level. One way to obtain estimates of current ice mass changes is to model the past history of the ice sheets and their underlying beds over the glacial cycles. Such calculations assist to distinguish between the longer-term ice-dynamic evolution and short-term mass-balance changes when interpreting altimetry data, and are helpful to isolate the effects of postglacial rebound from gravity and altimetry trends. The presentation will discuss results obtained from 3-D thermomechanical ice-sheet/lithosphere/bedrock models applied to the Antarctic and Greenland ice sheets. The simulations are forced by time-dependent boundary conditions derived from sediment and ice core records and are constrained by geomorphological and glacial-geological data of past ice sheet and sea-level stands. Current simulations suggest that the Greenland ice sheet is close to balance, while the Antarctic ice sheet is still losing mass, mainly due to incomplete grounding-line retreat of the West Antarctic ice sheet since the LGM. The results indicate that altimetry trends are likely dominated by ice thickness changes but that the gravitational signal mainly reflects postglacial rebound.

A novel closed cell culture device for fabrication of corneal epithelial cell sheets.

PubMed

Nakajima, Ryota; Kobayashi, Toyoshige; Moriya, Noboru; Mizutani, Manabu; Kan, Kazutoshi; Nozaki, Takayuki; Saitoh, Kazuo; Yamato, Masayuki; Okano, Teruo; Takeda, Shizu

2015-11-01

Automation technology for cell sheet-based tissue engineering would need to optimize the cell sheet fabrication process, stabilize cell sheet quality and reduce biological contamination risks. Biological contamination must be avoided in clinical settings. A closed culture system provides a solution for this. In the present study, we developed a closed culture device called a cell cartridge, to be used in a closed cell culture system for fabricating corneal epithelial cell sheets. Rabbit limbal epithelial cells were cultured on the surface of a porous membrane with 3T3 feeder cells, which are separate from the epithelial cells in the cell cartridges and in the cell-culture inserts as a control. To fabricate the stratified cell sheets, five different thicknesses of the membranes which were welded to the cell cartridge, were examined. Multilayered corneal epithelial cell sheets were fabricated in cell cartridges that were welded to a 25 µm-thick gas-permeable membrane, which was similar to the results with the cell-culture inserts. However, stratification of corneal epithelial cell sheets did not occur with cell cartridges that were welded to 100-300 µm-thick gas-permeable membranes. The fabricated cell sheets were evaluated by histological analyses to examine the expression of corneal epithelial-specific markers. Immunohistochemical analyses showed that a putative stem cell marker, p63, a corneal epithelial differentiation maker, CK3, and a barrier function marker, Claudin-1, were expressed in the appropriate position in the cell sheets. These results suggest that the cell cartridge is effective for fabricating corneal epithelial cell sheets. Copyright © 2012 John Wiley & Sons, Ltd.

24 CFR 1710.117 - Cost sheet, signature of Senior Executive Officer.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Cost sheet, signature of Senior... REGISTRATION Reporting Requirements § 1710.117 Cost sheet, signature of Senior Executive Officer. (a) Cost... description of our subdivision and development plans. Signature of Senior Executive Officer (2) Cost sheet...

46 CFR 160.005-1 - Incorporation by reference.

Code of Federal Regulations, 2014 CFR

2014-10-01

... makes reference to the following documents: (1) Federal Specification: L-P-375C—Plastic Film, Flexible....005-1: (Sheet 1) Cutting Pattern and General Arrangement (Adult). (Sheet 2) Alternate Stitching of Tapes and Webbing (Adult and Child). (Sheet 3) Pad Detail (Adult). (Sheet 4) Cutting Pattern and General...

46 CFR 160.005-1 - Incorporation by reference.

Code of Federal Regulations, 2013 CFR

2013-10-01

... makes reference to the following documents: (1) Federal Specification: L-P-375C—Plastic Film, Flexible....005-1: (Sheet 1) Cutting Pattern and General Arrangement (Adult). (Sheet 2) Alternate Stitching of Tapes and Webbing (Adult and Child). (Sheet 3) Pad Detail (Adult). (Sheet 4) Cutting Pattern and General...

46 CFR 160.005-1 - Incorporation by reference.

Code of Federal Regulations, 2012 CFR

2012-10-01

... makes reference to the following documents: (1) Federal Specification: L-P-375C—Plastic Film, Flexible....005-1: (Sheet 1) Cutting Pattern and General Arrangement (Adult). (Sheet 2) Alternate Stitching of Tapes and Webbing (Adult and Child). (Sheet 3) Pad Detail (Adult). (Sheet 4) Cutting Pattern and General...

46 CFR 160.005-1 - Incorporation by reference.

Code of Federal Regulations, 2011 CFR

2011-10-01

... makes reference to the following documents: (1) Federal Specification: L-P-375C—Plastic Film, Flexible....005-1: (Sheet 1) Cutting Pattern and General Arrangement (Adult). (Sheet 2) Alternate Stitching of Tapes and Webbing (Adult and Child). (Sheet 3) Pad Detail (Adult). (Sheet 4) Cutting Pattern and General...

17. INTAKE PIER, BRIDGE STRESS SHEET, SHEET 8 OF 117, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

17. INTAKE PIER, BRIDGE STRESS SHEET, SHEET 8 OF 117, 1920. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

76 FR 48122 - Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-08

... Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping Duty Administrative Review... on polyethylene terephthalate film, sheet, and strip (PET film) from Brazil. This administrative... antidumping duty order on PET film from Brazil. See Polyethylene Terephthalate Film, Sheet, and Strip From...

75 FR 49900 - Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-16

... Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping Duty Administrative Review... on polyethylene terephthalate film, sheet, and strip (PET film) from Brazil. This administrative... on PET film from Brazil. See Polyethylene Terephthalate Film, Sheet, and Strip From Brazil, the...

17 CFR 210.6-04 - Balance sheets.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Balance sheets. 210.6-04... 1940, AND ENERGY POLICY AND CONSERVATION ACT OF 1975 Registered Investment Companies § 210.6-04 Balance sheets. This rule is applicable to balance sheets filed by registered investment companies except for...

14 CFR Section 3 - Chart of Balance Sheet Accounts

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Chart of Balance Sheet Accounts Section 3 Section 3 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION... Balance Sheet Classifications Section 3 Chart of Balance Sheet Accounts [See footnotes at end of table...

49 CFR 1243.2 - Condensed balance sheet.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 9 2010-10-01 2010-10-01 false Condensed balance sheet. 1243.2 Section 1243.2... § 1243.2 Condensed balance sheet. Commencing with reports for the 3 months beginning January 1, 1972, and... hereby, required to compile and file quarterly reports of balance sheet items in accordance with...

49 CFR 1243.2 - Condensed balance sheet.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 9 2011-10-01 2011-10-01 false Condensed balance sheet. 1243.2 Section 1243.2... § 1243.2 Condensed balance sheet. Commencing with reports for the 3 months beginning January 1, 1972, and... hereby, required to compile and file quarterly reports of balance sheet items in accordance with...

14 CFR Section 3 - Chart of Balance Sheet Accounts

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Chart of Balance Sheet Accounts Section 3 Section 3 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION... Balance Sheet Classifications Section 3 Chart of Balance Sheet Accounts [See footnotes at end of table...

17 CFR 210.6-04 - Balance sheets.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Balance sheets. 210.6-04... 1940, AND ENERGY POLICY AND CONSERVATION ACT OF 1975 Registered Investment Companies § 210.6-04 Balance sheets. This rule is applicable to balance sheets filed by registered investment companies except for...

Skill Sheets for Agricultural Mechanics.

ERIC Educational Resources Information Center

Iowa State Univ. of Science and Technology, Ames. Dept. of Agricultural Education.

This set of 33 skill sheets for agricultural mechanics was developed for use in high school and vocational school agricultural mechanics programs. Some sheets teach operational procedures while others are for simple projects. Each skill sheet covers a single topic and includes: (1) a diagram, (2) a step-by-step construction or operational…

17 CFR 229.1001 - (Item 1001) Summary term sheet.

Code of Federal Regulations, 2010 CFR

2010-04-01

... sheet that is written in plain English. The summary term sheet must briefly describe in bullet point format the most material terms of the proposed transaction. The summary term sheet must provide security... transaction. The bullet points must cross-reference a more detailed discussion contained in the disclosure...

75 FR 55340 - Recovery Fact Sheet 9580.100, Mold Remediation

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-10

...] Recovery Fact Sheet 9580.100, Mold Remediation AGENCY: Federal Emergency Management Agency, DHS. ACTION... accepting comments on Recovery Fact Sheet RP9580.100, Mold Remediation. DATES: Comments must be received by... 20472-3100. II. Background The Recovery Fact Sheet RP9580.100, Mold Remediation, identifies the expenses...

Perforating Thin Metal Sheets

NASA Technical Reports Server (NTRS)

Davidson, M. E.

1985-01-01

Sheets only few mils thick bonded together, punched, then debonded. Three-step process yields perforated sheets of metal. (1): Individual sheets bonded together to form laminate. (2): laminate perforated in desired geometric pattern. (3): After baking, laminate separates into individual sheets. Developed for fabricating conductive layer on blankets that collect and remove ions; however, perforated foils have other applications - as conductive surfaces on insulating materials; stiffeners and conductors in plastic laminates; reflectors in antenna dishes; supports for thermal blankets; lightweight grille cover materials; and material for mockup of components.

Characterizing the Secondary Protein Structure of Black Widow Dragline Silk Using Solid-State NMR & X-ray Diffraction

PubMed Central

Jenkins, Janelle E.; Sampath, Sujatha; Butler, Emily; Kim, Jihyun; Henning, Robert W.; Holland, Gregory P.; Yarger, Jeffery L.

2013-01-01

This study provides a detailed secondary structural characterization of major ampullate dragline silk from Latrodectus hesperus (black widow) spiders. X-ray diffraction results show that the structure of black widow major ampullate silk fibers is comprised of stacked β-sheet nanocrystallites oriented parallel to the fiber axis and an amorphous region with oriented (anisotropic) and isotropic components. The combination of two-dimensional (2D) 13C-13C through-space and through-bond solid-state NMR experiments provide chemical shifts that are used to determine detailed information about amino acid motif secondary structure in black widow spider dragline silk. Individual amino acids are incorporated into different repetitive motifs that make up the majority of this protein-based biopolymer. From the solid-state NMR measurements, we assign distinct secondary conformations to each repetitive amino acid motif and hence to the amino acids that make up the motifs. Specifically, alanine is incorporated in β-sheet (poly(Alan) and poly(Gly-Ala)), 31-helix (poly(Gly-Gly-Xaa), and α-helix (poly(Gln-Gln-Ala-Tyr)) components. Glycine is determined to be in β-sheet (poly(Gly-Ala)) and 31-helical (poly(Gly-Gly-Xaa)) regions, while serine is present in β-sheet (poly(Gly-Ala-Ser)), 31-helix (poly(Gly-Gly-Ser)), and β-turn (poly(Gly-Pro-Ser)) structures. These various motif-specific secondary structural elements are quantitatively correlated to the primary amino acid sequence of major ampullate spidroin 1 and 2 (MaSp1 and MaSp2) and are shown to form a self-consistent model for black widow dragline silk. PMID:24024617

Interfacial Strength and Physical Properties of Functionalized Graphene - Epoxy Nanocomposites

NASA Technical Reports Server (NTRS)

Miller, Sandi G.; Heimann, Paula; Scheiman, Daniel; Adamson, Douglas H.; Aksay, Iihan A.; Prud'homme, Robert K.

2006-01-01

The toughness and coefficient of thermal expansion of a series of functionalized graphene sheet - epoxy nanocomposites are investigated. Functionalized graphene sheets are produced by splitting graphite oxide into single graphene sheets through a rapid thermal expansion process. These graphene sheets contain approx. 10% oxygen due to the presence of hydroxide, epoxide, and carboxyl functional groups which assist in chemical bond formation with the epoxy matrix. Intrinsic surface functionality is used to graft alkyl amine chains on the graphene sheets, and the addition of excess hardener insures covalent bonding between the epoxide matrix and graphene sheets. Considerable improvement in the epoxy dimensional stability is obtained. An increase in nanocomposite toughness is observed in some cases.

Solid/melt interface studies of high-speed silicon sheet growth

NASA Technical Reports Server (NTRS)

Ciszek, T. F.

1984-01-01

Radial growth-rate anisotropies and limiting growth forms of point nucleated, dislocation-free silicon sheets spreading horizontally on the free surface of a silicon melt have been measured for (100), (110), (111), and (112) sheet planes. Sixteen-millimeter movie photography was used to record the growth process. Analysis of the sheet edges has lead to predicted geometries for the tip shape of unidirectional, dislocation-free, horizontally growing sheets propagating in various directions within the above-mentioned planes. Similar techniques were used to study polycrystalline sheets and dendrite propagation. For dendrites, growth rates on the order of 2.5 m/min and growth rate anisotropies on the order of 25 were measured.

Impact verification of space suit design for space station

NASA Technical Reports Server (NTRS)

Fish, Richard H.

1987-01-01

The ballistic limits of single sheet and double sheet structures made of 6061 T6 Aluminum of 1.8 mm and larger nominal thickness were investigated for projectiles of 1.5 mm diameter fired in the Vertical Gun Range Test Facility and NASA Ames Research Center. The hole diameters and sheet deformation behavior were studied for various ratios of sheet spacing to projectile diameter. The results indicate that for projectiles of less than 1.5 mm diameter the ballistic limit exceeds the nominal 10 km/sec orbital debris encounter velocity, if a single-sheet suit of 1.8 mm thickness is behind a single bumper sheet of 1 mm thickness spaced 12.5 mm apart.

Fabrication method for cores of structural sandwich materials including star shaped core cells

DOEpatents

Christensen, Richard M.

1997-01-01

A method for fabricating structural sandwich materials having a core pattern which utilizes star and non-star shaped cells. The sheets of material are bonded together or a single folded sheet is used, and bonded or welded at specific locations, into a flat configuration, and are then mechanically pulled or expanded normal to the plane of the sheets which expand to form the cells. This method can be utilized to fabricate other geometric cell arrangements than the star/non-star shaped cells. Four sheets of material (either a pair of bonded sheets or a single folded sheet) are bonded so as to define an area therebetween, which forms the star shaped cell when expanded.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erkaev, N. V.; Siberian Federal University, Krasnoyarsk; Semenov, V. S.

A new kind of magnetohydrodynamic instability and waves are analyzed for a current sheet in the presence of a small normal magnetic field component varying along the sheet. These waves and instability are related to the existence of two gradients of the tangential (B{sub {tau}}) and normal (B{sub n}) magnetic field components along the normal ({nabla}{sub n}B{sub {tau}}) and tangential ({nabla}{sub {tau}}B{sub n}) directions with respect to the current sheet. The current sheet can be stable or unstable if the multiplication of two magnetic gradients is positive or negative. In the stable region, the kinklike wave mode is interpreted asmore » so-called flapping waves observed in Earth's magnetotail current sheet. The kink wave group velocity estimated for the Earth's current sheet is of the order of a few tens of kilometers per second. This is in good agreement with the observations of the flapping motions of the magnetotail current sheet.« less

Infused polymers for cell sheet release

NASA Astrophysics Data System (ADS)

Juthani, Nidhi; Howell, Caitlin; Ledoux, Haylea; Sotiri, Irini; Kelso, Susan; Kovalenko, Yevgen; Tajik, Amanda; Vu, Thy L.; Lin, Jennifer J.; Sutton, Amy; Aizenberg, Joanna

2016-05-01

Tissue engineering using whole, intact cell sheets has shown promise in many cell-based therapies. However, current systems for the growth and release of these sheets can be expensive to purchase or difficult to fabricate, hindering their widespread use. Here, we describe a new approach to cell sheet release surfaces based on silicone oil-infused polydimethylsiloxane. By coating the surfaces with a layer of fibronectin (FN), we were able to grow mesenchymal stem cells to densities comparable to those of tissue culture polystyrene controls (TCPS). Simple introduction of oil underneath an edge of the sheet caused it to separate from the substrate. Characterization of sheets post-transfer showed that they retain their FN layer and morphology, remain highly viable, and are able to grow and proliferate normally after transfer. We expect that this method of cell sheet growth and detachment may be useful for low-cost, flexible, and customizable production of cellular layers for tissue engineering.

Effect of a large-sized silicone sheet upon recovery of mastoid aeration after mastoidectomy.

PubMed

Kazama, Kyosuke; Takahashi, Haruo; Kaieda, Satoru; Iwanaga, Tetsu; Yamamoto-Fukuda, Tomomi; Yoshida, Haruo; Kumagami, Hidetaka; Takasaki, Kenji

2008-06-01

To evaluate the effect of our large-sized silicone sheet upon postoperative recovery of mastoid aeration in ears after surgery including mastoidectomy and soft-wall reconstruction (SWR). Retrospective chart review in a tertiary care center. Recovery of mastoid aeration was assessed by CT 4 to 12 months after surgery on 72 ears (69 patients), in which the silicone sheet covering from the eustachian tube (ET) to the mastoid was placed after SWR procedure with mastoidectomy were done for their chronic otitis media. Results were compared with those with a small silicone sheet. Recovery of mastoid aeration was significantly better in the large-silicone-sheet group than in the small-silicone-sheet group (chi(2) value = 11.7146, P = 0.0006). This preliminary study suggested that our large-sized silicone sheet may be effective for postoperative recovery of mastoid aeration even in ears operated with SWR procedure.

Infused polymers for cell sheet release

PubMed Central

Juthani, Nidhi; Howell, Caitlin; Ledoux, Haylea; Sotiri, Irini; Kelso, Susan; Kovalenko, Yevgen; Tajik, Amanda; Vu, Thy L.; Lin, Jennifer J.; Sutton, Amy; Aizenberg, Joanna

2016-01-01

Tissue engineering using whole, intact cell sheets has shown promise in many cell-based therapies. However, current systems for the growth and release of these sheets can be expensive to purchase or difficult to fabricate, hindering their widespread use. Here, we describe a new approach to cell sheet release surfaces based on silicone oil-infused polydimethylsiloxane. By coating the surfaces with a layer of fibronectin (FN), we were able to grow mesenchymal stem cells to densities comparable to those of tissue culture polystyrene controls (TCPS). Simple introduction of oil underneath an edge of the sheet caused it to separate from the substrate. Characterization of sheets post-transfer showed that they retain their FN layer and morphology, remain highly viable, and are able to grow and proliferate normally after transfer. We expect that this method of cell sheet growth and detachment may be useful for low-cost, flexible, and customizable production of cellular layers for tissue engineering. PMID:27189419

Infused polymers for cell sheet release.

PubMed

Juthani, Nidhi; Howell, Caitlin; Ledoux, Haylea; Sotiri, Irini; Kelso, Susan; Kovalenko, Yevgen; Tajik, Amanda; Vu, Thy L; Lin, Jennifer J; Sutton, Amy; Aizenberg, Joanna

2016-05-18

Tissue engineering using whole, intact cell sheets has shown promise in many cell-based therapies. However, current systems for the growth and release of these sheets can be expensive to purchase or difficult to fabricate, hindering their widespread use. Here, we describe a new approach to cell sheet release surfaces based on silicone oil-infused polydimethylsiloxane. By coating the surfaces with a layer of fibronectin (FN), we were able to grow mesenchymal stem cells to densities comparable to those of tissue culture polystyrene controls (TCPS). Simple introduction of oil underneath an edge of the sheet caused it to separate from the substrate. Characterization of sheets post-transfer showed that they retain their FN layer and morphology, remain highly viable, and are able to grow and proliferate normally after transfer. We expect that this method of cell sheet growth and detachment may be useful for low-cost, flexible, and customizable production of cellular layers for tissue engineering.

Intermittent magnetic reconnection in TS-3 merging experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ono, Y.; Hayashi, Y.; Ii, T.

2011-11-15

Ejection of current sheet with plasma mass causes impulsive and intermittent magnetic reconnection in the TS-3 spherical tokamak (ST) merging experiment. Under high guide toroidal field, the sheet resistivity is almost classical due to the sheet thickness much longer than the ion gyroradius. Large inflow flux and low current-sheet resistivity result in flux and plasma pileup followed by rapid growth of the current sheet. When the pileup exceeds a critical limit, the sheet is ejected mechanically from the squeezed X-point area. The reconnection (outflow) speed is slow during the flux/plasma pileup and is fast during the ejection, suggesting that intermittentmore » reconnection similar to the solar flare increases the averaged reconnection speed. These transient effects enable the merging tokamaks to have the fast reconnection as well as the high-power reconnection heating, even when their current-sheet resistivity is low under high guide field.« less

Increases in plasma sheet temperature with solar wind driving during substorm growth phases

NASA Astrophysics Data System (ADS)

Forsyth, C.; Watt, C. E. J.; Rae, I. J.; Fazakerley, A. N.; Kalmoni, N. M. E.; Freeman, M. P.; Boakes, P. D.; Nakamura, R.; Dandouras, I.; Kistler, L. M.; Jackman, C. M.; Coxon, J. C.; Carr, C. M.

2014-12-01

During substorm growth phases, magnetic reconnection at the magnetopause extracts ~1015 J from the solar wind which is then stored in the magnetotail lobes. Plasma sheet pressure increases to balance magnetic flux density increases in the lobes. Here we examine plasma sheet pressure, density, and temperature during substorm growth phases using 9 years of Cluster data (>316,000 data points). We show that plasma sheet pressure and temperature are higher during growth phases with higher solar wind driving, whereas the density is approximately constant. We also show a weak correlation between plasma sheet temperature before onset and the minimum SuperMAG AL (SML) auroral index in the subsequent substorm. We discuss how energization of the plasma sheet before onset may result from thermodynamically adiabatic processes; how hotter plasma sheets may result in magnetotail instabilities, and how this relates to the onset and size of the subsequent substorm expansion phase.

Scanning light-sheet microscopy in the whole mouse brain with HiLo background rejection

PubMed Central

Mertz, Jerome; Kim, Jinhyun

2010-01-01

It is well known that light-sheet illumination can enable optically sectioned wide-field imaging of macroscopic samples. However, the optical sectioning capacity of a light-sheet macroscope is undermined by sample-induced scattering or aberrations that broaden the thickness of the sheet illumination. We present a technique to enhance the optical sectioning capacity of a scanning light-sheet microscope by out-of-focus background rejection. The technique, called HiLo microscopy, makes use of two images sequentially acquired with uniform and structured sheet illumination. An optically sectioned image is then synthesized by fusing high and low spatial frequency information from both images. The benefits of combining light-sheet macroscopy and HiLo background rejection are demonstrated in optically cleared whole mouse brain samples, using both green fluorescent protein (GFP)-fluorescence and dark-field scattered light contrast. PMID:20210471

Method for shaping sheet thermoplastic and the like

NASA Technical Reports Server (NTRS)

Akilian, Mireille K. (Inventor); Schattenburg, Mark L. (Inventor)

2011-01-01

Processes and apparati for shaping sheet glass or thermoplastic materials use force from a layer of a flowing fluid, such as air, between the sheet and a mandrel at close to the softening temperature of the thermoplastic. The shape is preserved by cooling. The shape of the air bearing mandrel and the pressure distribution of the fluid contribute to the final shape. A process can be conducted on one or two surfaces such that the force from the air layer is on one or two surfaces of the sheet. The gap size between the sheet and mandrel determines the pressure profile in the gap, which also determines the final sheet shape. In general, smaller gaps lead to larger viscous forces. The pressure profile depends on the shape of the mandrel, the size of the fluid gap and the sheet and the fluid supply pressure.

Large patternable metal nanoparticle sheets by photo/e-beam lithography

NASA Astrophysics Data System (ADS)

Saito, Noboru; Wang, Pangpang; Okamoto, Koichi; Ryuzaki, Sou; Tamada, Kaoru

2017-10-01

Techniques for micro/nano-scale patterning of large metal nanoparticle sheets can potentially be used to realize high-performance photoelectronic devices because the sheets provide greatly enhanced electrical fields around the nanoparticles due to localized surface plasmon resonances. However, no single metal nanoparticle sheet currently exists with sufficient durability for conventional lithographical processes. Here, we report large photo and/or e-beam lithographic patternable metal nanoparticle sheets with improved durability by incorporating molecular cross-linked structures between nanoparticles. The cross-linked structures were easily formed by a one-step chemical reaction; immersing a single nanoparticle sheet consisting of core metals, to which capping molecules ionically bond, in a dithiol ethanol solution. The ligand exchange reaction processes were discussed in detail, and we demonstrated 20 μm wide line and space patterns, and a 170 nm wide line of the silver nanoparticle sheets.

Thin sheets achieve optimal wrapping of liquids

NASA Astrophysics Data System (ADS)

Paulsen, Joseph; Démery, Vincent; Davidovitch, Benny; Santangelo, Christian; Russell, Thomas; Menon, Narayanan

2015-03-01

A liquid drop can wrap itself in a sheet using capillary forces [Py et al., PRL 98, 2007]. However, the efficiency of ``capillary origami'' at covering the surface of a drop is hampered by the mechanical cost of bending the sheet. Thinner sheets deform more readily by forming small-scale wrinkles and stress-focussing patterns, but it is unclear how coverage efficiency competes with mechanical cost as thickness is decreased, and what wrapping shapes will emerge. We place a thin (~ 100 nm) polymer film on a drop whose volume is gradually decreased so that the sheet covers an increasing fraction of its surface. The sheet exhibits a complex sequence of axisymmetric and polygonal partially- and fully- wrapped shapes. Remarkably, the progression appears independent of mechanical properties. The gross shape, which neglects small-scale features, is correctly predicted by a simple geometric approach wherein the exposed area is minimized. Thus, simply using a thin enough sheet results in maximal coverage.

Ultraviolet photodetectors based on ZnO sheets: The effect of sheet size on photoresponse properties

NASA Astrophysics Data System (ADS)

Ghasempour Ardakani, Abbas; Pazoki, Meysam; Mahdavi, Seyed Mohammad; Bahrampour, Ali Reza; Taghavinia, Nima

2012-05-01

In this work, ultraviolet photodetectors based on electrodeposited ZnO sheet thin films were fabricated on a glass substrate. Before electrodeposition, a thin buffer layer of ZnO was deposited on the glass by pulsed laser deposition method. This layer not only acted as a nucleation site for ZnO sheet growth, but also made it possible to use cheap glass substrate instead of conventional fluorine-doped tin oxide (FTO) substrate. Our results showed that photoresponse properties of the photodetectors strongly depend on the sheet sizes. The smaller sheets exhibited enhanced photosensitivity, shortened fall times and decreased gain compared to larger ones. We showed that photodetectors based on ZnO sheets have a faster response than ones based on polycrystalline films. It was also shown that even less response time could be obtained by using comb-like electrodes instead of two-electrode.

Increases in plasma sheet temperature with solar wind driving during substorm growth phases

PubMed Central

Forsyth, C; Watt, C E J; Rae, I J; Fazakerley, A N; Kalmoni, N M E; Freeman, M P; Boakes, P D; Nakamura, R; Dandouras, I; Kistler, L M; Jackman, C M; Coxon, J C; Carr, C M

2014-01-01

During substorm growth phases, magnetic reconnection at the magnetopause extracts ∼1015 J from the solar wind which is then stored in the magnetotail lobes. Plasma sheet pressure increases to balance magnetic flux density increases in the lobes. Here we examine plasma sheet pressure, density, and temperature during substorm growth phases using 9 years of Cluster data (>316,000 data points). We show that plasma sheet pressure and temperature are higher during growth phases with higher solar wind driving, whereas the density is approximately constant. We also show a weak correlation between plasma sheet temperature before onset and the minimum SuperMAG AL (SML) auroral index in the subsequent substorm. We discuss how energization of the plasma sheet before onset may result from thermodynamically adiabatic processes; how hotter plasma sheets may result in magnetotail instabilities, and how this relates to the onset and size of the subsequent substorm expansion phase. PMID:26074645

Increases in plasma sheet temperature with solar wind driving during substorm growth phases.

PubMed

Forsyth, C; Watt, C E J; Rae, I J; Fazakerley, A N; Kalmoni, N M E; Freeman, M P; Boakes, P D; Nakamura, R; Dandouras, I; Kistler, L M; Jackman, C M; Coxon, J C; Carr, C M

2014-12-28

During substorm growth phases, magnetic reconnection at the magnetopause extracts ∼10 15  J from the solar wind which is then stored in the magnetotail lobes. Plasma sheet pressure increases to balance magnetic flux density increases in the lobes. Here we examine plasma sheet pressure, density, and temperature during substorm growth phases using 9 years of Cluster data (>316,000 data points). We show that plasma sheet pressure and temperature are higher during growth phases with higher solar wind driving, whereas the density is approximately constant. We also show a weak correlation between plasma sheet temperature before onset and the minimum SuperMAG AL (SML) auroral index in the subsequent substorm. We discuss how energization of the plasma sheet before onset may result from thermodynamically adiabatic processes; how hotter plasma sheets may result in magnetotail instabilities, and how this relates to the onset and size of the subsequent substorm expansion phase.

Comparative study on predicting Young's modulus of graphene sheets using nano-scale continuum mechanics approach

NASA Astrophysics Data System (ADS)

Rafiee, Roham; Eskandariyun, Amirali

2017-06-01

In this research, nano-scale continuum modeling is employed to predict Young's modulus of graphene sheet. The lattice nano-structure of a graphene sheet is replaced with a discrete space-frame structure simulating carbon-carbon bonds with either beam or spring elements. A comparative study is carried out to check the influence of employed elements on estimated Young's moduli of graphene sheets in both horizontal and vertical directions. A detailed analysis is also conducted to investigate the influence of graphene sheet sizes on its Young's modulus and corresponding aspect ratios that unwelcomed end effects disappear on the results are extracted. At the final stage, defected graphene sheets suffering from vacancy defects are investigated through a stochastic analysis taking into account both number of defects and their locations as random parameters. The reduction level in the Young's moduli of defected graphene sheets compared with non-defected ones is analyzed and reported.

Ceramic substrate including thin film multilayer surface conductor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolf, Joseph Ambrose; Peterson, Kenneth A.

2017-05-09

A ceramic substrate comprises a plurality of ceramic sheets, a plurality of inner conductive layers, a plurality of vias, and an upper conductive layer. The ceramic sheets are stacked one on top of another and include a top ceramic sheet. The inner conductive layers include electrically conductive material that forms electrically conductive features on an upper surface of each ceramic sheet excluding the top ceramic sheet. The vias are formed in each of the ceramic sheets with each via being filled with electrically conductive material. The upper conductive layer includes electrically conductive material that forms electrically conductive features on anmore » upper surface of the top ceramic sheet. The upper conductive layer is constructed from a stack of four sublayers. A first sublayer is formed from titanium. A second sublayer is formed from copper. A third sublayer is formed from platinum. A fourth sublayer is formed from gold.« less

Potential Climatic Effects on the Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Bindschadler, R. A.

1984-01-01

The Greenland Ice Sheet covers an area of 1,720,000 sq. km and contains approximately 2,600,000 cu km of ice. Most of the ice sheet receives an excess of snow accumulation over the amount of ice lost to wind, meltwater run-off or other ablative processes. The majority of mass loss occurs at the margin of the ice sheet as either surface melt, which flows into the sea or calving of icebergs from the tongues of outlet glaciers. Many estimates of these processes were published. An average of five published estimates is summarized. If these estimates are correct, then the Greenland Ice Sheet is in approximate equilibrium and contributes 490 cu km/a of fresh water to the North Atlantic and Arctic Oceans. Climate effects, ice sheet flow, and application of remote sensing to tracking of the ice sheet are discussed.

Evolution of tholeiitic diabase sheet systems in the eastern United States: examples from the Culpeper Basin, Virginia-Maryland, and the Gettysburg Basin, Pennsylvania

USGS Publications Warehouse

Woodruff, L.G.; Froelich, A.J.; Belkin, H.E.; Gottfried, D.

1995-01-01

High-TiO2, quartz-normative (HTQ) tholeiite sheets of Early Jurassic age have intruded mainly Late Triassic sedimentary rocks in several early Mesozoic basins in the eastern US. Field observations, petrographic study, geochemical analyses and stable isotope data from three HTQ sheet systems were used to develop a general model of magmatic differentiation and magmatic-hydrothermal interaction for HTQ sheets. The three sheet systems have remarkably similar major-oxide and trace-element compositions. Cumulus and evolved diabase in comagmatic sheets separated by tens of kilometers are related by igneous differentiation. Differentiated diabase in all three sheets have petrographic and geochemical signatures and fluid inclusions indicating hydrothermal alteration beginning near magmatic temperatures and continuing to relatively low temperatures. Sulfur and oxygen isotope data are consistent with a magmatic origin for the hydrothermal fluid. -from Authors

Effects of flow sheet implementation on physician performance in the management of asthmatic patients.

PubMed

Ruoff, Gary

2002-01-01

This project focused on increasing compliance, in a large family practice group, with quality indicators for the management of asthma. The objective was to determine if use of a flow sheet incorporating the Global Initiative for Asthma (GINA) guidelines could improve compliance with those guidelines if the flow sheet was placed in patients' medical records. After review and selection of 14 clinical quality indicators, physicians in the practice implemented a flow sheet as an intervention. These flow sheets were inserted into the records of 122 randomly selected patients with asthma. Medical records were reviewed before the flow sheets were placed in the records, and again approximately 6 months later, to determine if there was a change in compliance with the quality indicators. Improvement of documentation was demonstrated in 13 of the 14 quality indicators. The results indicate that compliance with asthma management quality indicators can improve with the use of a flow sheet.

75 FR 69629 - Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic of China: Extension...

Federal Register 2010, 2011, 2012, 2013, 2014

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... Film, Sheet, and Strip From the People's Republic of China: Extension of Time Limit for the Final... the initiation of the antidumping duty administrative review on polyethylene terephthalate film, sheet... the preliminary results of this review. See Polyethylene Terephthalate Film, Sheet, and Strip From the...

16 CFR 460.13 - Fact sheets.

Code of Federal Regulations, 2012 CFR

2012-01-01

... heat flow. The higher the R-value, the greater the insulating power. Compare insulation R-values before... INSULATION § 460.13 Fact sheets. If you are a manufacturer, you must give retailers and installers fact sheets for the insulation products you sell to them. Each sheet must contain what is listed here. You can...

16 CFR 460.13 - Fact sheets.

Code of Federal Regulations, 2010 CFR

2010-01-01

... heat flow. The higher the R-value, the greater the insulating power. Compare insulation R-values before... INSULATION § 460.13 Fact sheets. If you are a manufacturer, you must give retailers and installers fact sheets for the insulation products you sell to them. Each sheet must contain what is listed here. You can...

16 CFR 460.13 - Fact sheets.

Code of Federal Regulations, 2014 CFR

2014-01-01

... heat flow. The higher the R-value, the greater the insulating power. Compare insulation R-values before... INSULATION § 460.13 Fact sheets. If you are a manufacturer, you must give retailers and installers fact sheets for the insulation products you sell to them. Each sheet must contain what is listed here. You can...

16 CFR 460.13 - Fact sheets.

Code of Federal Regulations, 2013 CFR

2013-01-01

... heat flow. The higher the R-value, the greater the insulating power. Compare insulation R-values before... INSULATION § 460.13 Fact sheets. If you are a manufacturer, you must give retailers and installers fact sheets for the insulation products you sell to them. Each sheet must contain what is listed here. You can...

16 CFR 460.13 - Fact sheets.

Code of Federal Regulations, 2011 CFR

2011-01-01

... heat flow. The higher the R-value, the greater the insulating power. Compare insulation R-values before... INSULATION § 460.13 Fact sheets. If you are a manufacturer, you must give retailers and installers fact sheets for the insulation products you sell to them. Each sheet must contain what is listed here. You can...

46 CFR 160.002-1 - Incorporation by reference.

Code of Federal Regulations, 2014 CFR

2014-10-01

.... General Purpose, Natural or in Colors. (2) Federal Specification: L-P-375—Plastic Film, Flexible, Vinyl...: (Sheet 1) Cutting Pattern and General Arrangement (adult). (Sheet 1A) Alternate stitching of tapes and webbing (adult and child). (Sheet 2) Pad Detail (adult). Dwg. No. F-49-6-5: (Sheet 1) Cutting Pattern and...

46 CFR 160.002-1 - Incorporation by reference.

Code of Federal Regulations, 2013 CFR

2013-10-01

.... General Purpose, Natural or in Colors. (2) Federal Specification: L-P-375—Plastic Film, Flexible, Vinyl...: (Sheet 1) Cutting Pattern and General Arrangement (adult). (Sheet 1A) Alternate stitching of tapes and webbing (adult and child). (Sheet 2) Pad Detail (adult). Dwg. No. F-49-6-5: (Sheet 1) Cutting Pattern and...

46 CFR 160.002-1 - Incorporation by reference.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... General Purpose, Natural or in Colors. (2) Federal Specification: L-P-375—Plastic Film, Flexible, Vinyl...: (Sheet 1) Cutting Pattern and General Arrangement (adult). (Sheet 1A) Alternate stitching of tapes and webbing (adult and child). (Sheet 2) Pad Detail (adult). Dwg. No. F-49-6-5: (Sheet 1) Cutting Pattern and...

46 CFR 160.002-1 - Incorporation by reference.

Code of Federal Regulations, 2011 CFR

2011-10-01

.... General Purpose, Natural or in Colors. (2) Federal Specification: L-P-375—Plastic Film, Flexible, Vinyl...: (Sheet 1) Cutting Pattern and General Arrangement (adult). (Sheet 1A) Alternate stitching of tapes and webbing (adult and child). (Sheet 2) Pad Detail (adult). Dwg. No. F-49-6-5: (Sheet 1) Cutting Pattern and...

46 CFR 160.002-1 - Incorporation by reference.

Code of Federal Regulations, 2012 CFR

2012-10-01

.... General Purpose, Natural or in Colors. (2) Federal Specification: L-P-375—Plastic Film, Flexible, Vinyl...: (Sheet 1) Cutting Pattern and General Arrangement (adult). (Sheet 1A) Alternate stitching of tapes and webbing (adult and child). (Sheet 2) Pad Detail (adult). Dwg. No. F-49-6-5: (Sheet 1) Cutting Pattern and...

Wind and Water Power Fact Sheets | Wind | NREL

Science.gov Websites

Advanced Control Turbine Systems to Increase Performance, Decrease Structural Loading of Wind Turbines and and Water Power Fact Sheets Wind and Water Power Fact Sheets The capabilities for research at the National Wind Technology Center (NWTC) are numerous. Below you will find fact sheets about the many

76 FR 30908 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results of Antidumping Duty...

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78 FR 79400 - Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic of China: Initiation...

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75 FR 69400 - Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of Time Limit for...

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76 FR 18519 - Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Amended Final Results of...

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77 FR 14501 - Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of Time Limit for...

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76 FR 57715 - Polyethylene Terephthalate Film, Sheet, and Strip From the Republic of Korea: Revocation of...

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... Film, Sheet, and Strip From the Republic of Korea: Final Results of Antidumping Duty Administrative... administrative review of the antidumping order on polyethylene terephthalate film, sheet and strip (PET film) from the Republic of Korea (Korea). See Polyethylene Terephthalate Film, Sheet, and Strip from the...

78 FR 35245 - Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic of China: Final...

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17 CFR 210.3-01 - Consolidated balance sheets.

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2011-04-01

... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Consolidated balance sheets... Statements § 210.3-01 Consolidated balance sheets. (a) There shall be filed, for the registrant and its subsidiaries consolidated, audited balance sheets as of the end of each of the two most recent fiscal years. If...

17 CFR 210.5-02 - Balance sheets.

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2010-04-01

... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Balance sheets. 210.5-02... Balance sheets. The purpose of this rule is to indicate the various line items and certain additional... face of the balance sheets or related notes filed for the persons to whom this article pertains (see...

17 CFR 210.9-03 - Balance sheets.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Balance sheets. 210.9-03... 1940, AND ENERGY POLICY AND CONSERVATION ACT OF 1975 Bank Holding Companies § 210.9-03 Balance sheets... face of the balance sheets or in the notes thereto. Assets 1. Cash and due from banks. The amounts in...

17 CFR 210.3-01 - Consolidated balance sheets.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Consolidated balance sheets... Statements § 210.3-01 Consolidated balance sheets. (a) There shall be filed, for the registrant and its subsidiaries consolidated, audited balance sheets as of the end of each of the two most recent fiscal years. If...

17 CFR 210.9-03 - Balance sheets.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Balance sheets. 210.9-03... 1940, AND ENERGY POLICY AND CONSERVATION ACT OF 1975 Bank Holding Companies § 210.9-03 Balance sheets... face of the balance sheets or in the notes thereto. Assets 1. Cash and due from banks. The amounts in...

17 CFR 210.7-03 - Balance sheets.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Balance sheets. 210.7-03... 1940, AND ENERGY POLICY AND CONSERVATION ACT OF 1975 Insurance Companies § 210.7-03 Balance sheets. (a... otherwise permitted by the Commission, should appear on the face of the balance sheets and in the notes...

17 CFR 210.7-03 - Balance sheets.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Balance sheets. 210.7-03... 1940, AND ENERGY POLICY AND CONSERVATION ACT OF 1975 Insurance Companies § 210.7-03 Balance sheets. (a... otherwise permitted by the Commission, should appear on the face of the balance sheets and in the notes...

17 CFR 210.5-02 - Balance sheets.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Balance sheets. 210.5-02... Balance sheets. The purpose of this rule is to indicate the various line items and certain additional... face of the balance sheets or related notes filed for the persons to whom this article pertains (see...

The Physics of Ice Sheets

ERIC Educational Resources Information Center

Bassis, J. N.

2008-01-01

The great ice sheets in Antarctica and Greenland are vast deposits of frozen freshwater that contain enough to raise sea level by approximately 70 m if they were to completely melt. Because of the potentially catastrophic impact that ice sheets can have, it is important that we understand how ice sheets have responded to past climate changes and…

Introduction to Sheet Metal. Instructor Edition. Introduction to Construction Series.

ERIC Educational Resources Information Center

Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

This instructor's guide contains the materials required to teach a competency-based introductory course in sheet metal work to students who have chosen to explore careers in construction. The following topics are covered in the course's three instructional units: sheet metal materials, sheet metal tools, and applied skills. Each unit contains some…

19 CFR 123.6 - Train sheet for arriving railroad trains.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Train sheet for arriving railroad trains. 123.6 Section 123.6 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY..., sometimes called a consist, bridge sheet, or trip sheet, listing each car and showing the car numbers and...

19 CFR 123.6 - Train sheet for arriving railroad trains.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 19 Customs Duties 1 2011-04-01 2011-04-01 false Train sheet for arriving railroad trains. 123.6 Section 123.6 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY... called a consist, bridge sheet, or trip sheet, listing each car and showing the car numbers and initials. ...

Clinching for sheet materials

PubMed Central

He, Xiaocong

2017-01-01

Abstract Latest developments in the clinching of sheet materials are reviewed in this article. Important issues are discussed, such as tool design, process parameters and joinability of some new lightweight sheet materials. Hybrid and modified clinching processes are introduced to a general reader. Several unaddressed issues in the clinching of sheet materials are identified. PMID:28656065

Computer-aided light sheet flow visualization using photogrammetry

NASA Technical Reports Server (NTRS)

Stacy, Kathryn; Severance, Kurt; Childers, Brooks A.

1994-01-01

A computer-aided flow visualization process has been developed to analyze video images acquired from rotating and translating light sheet visualization systems. The computer process integrates a mathematical model for image reconstruction, advanced computer graphics concepts, and digital image processing to provide a quantitative and a visual analysis capability. The image reconstruction model, based on photogrammetry, uses knowledge of the camera and light sheet locations and orientations to project two-dimensional light sheet video images into three-dimensional space. A sophisticated computer visualization package, commonly used to analyze computational fluid dynamics (CFD) results, was chosen to interactively display the reconstructed light sheet images with the numerical surface geometry for the model or aircraft under study. The photogrammetric reconstruction technique and the image processing and computer graphics techniques and equipment are described. Results of the computer-aided process applied to both a wind tunnel translating light sheet experiment and an in-flight rotating light sheet experiment are presented. The capability to compare reconstructed experimental light sheet images with CFD solutions in the same graphics environment is also demonstrated.

Computer-Aided Light Sheet Flow Visualization

NASA Technical Reports Server (NTRS)

Stacy, Kathryn; Severance, Kurt; Childers, Brooks A.

1993-01-01

A computer-aided flow visualization process has been developed to analyze video images acquired from rotating and translating light sheet visualization systems. The computer process integrates a mathematical model for image reconstruction, advanced computer graphics concepts, and digital image processing to provide a quantitative and visual analysis capability. The image reconstruction model, based on photogrammetry, uses knowledge of the camera and light sheet locations and orientations to project two-dimensional light sheet video images into three-dimensional space. A sophisticated computer visualization package, commonly used to analyze computational fluid dynamics (CFD) data sets, was chosen to interactively display the reconstructed light sheet images, along with the numerical surface geometry for the model or aircraft under study. A description is provided of the photogrammetric reconstruction technique, and the image processing and computer graphics techniques and equipment. Results of the computer aided process applied to both a wind tunnel translating light sheet experiment and an in-flight rotating light sheet experiment are presented. The capability to compare reconstructed experimental light sheet images and CFD solutions in the same graphics environment is also demonstrated.

Implementation of a Diabetes Management Flow Sheet in a Long-Term Care Setting.

PubMed

Williams, Evelyn; Curtis, Ashley

2015-08-01

Physicians lack clear guidance about adaptation of clinical practice guidelines for elderly institutionalized patients with diabetes. In a large long-term care facility, a diabetes management flow sheet was trialed to determine which clinical parameters were found useful by clinicians in the management of diabetes in that setting. Clinical practice guidelines for diabetes management were reviewed with attending physicians. Diabetes management flow sheets were distributed for all patients coded as having diabetes on their most recent minimum data sets. After a period of 14 months, flow sheet completion rates were ascertained and physicians were surveyed regarding the utility of the flow sheet. Initial flow sheet data were completed in full or in part for only 57% of the 121 study subjects; 39% of the subjects died within 14 months. Quarterly follow-up data were completed for 58% of the flow sheets. The diabetes management flow sheet was not found to be useful by attending physicians as a chronic-disease management tool. Copyright © 2015 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

Preparation of Caco-2 cell sheets using plasma polymerised acrylic acid as a weak boundary layer.

PubMed

Majani, Ruby; Zelzer, Mischa; Gadegaard, Nikolaj; Rose, Felicity R; Alexander, Morgan R

2010-09-01

The use of cell sheets for tissue engineering applications has considerable advantages over single cell seeding techniques. So far, only thermoresponsive surfaces have been used to manufacture cell sheets without chemically disrupting the cell-surface interactions. Here, we present a new and facile technique to prepare sheets of epithelial cells using plasma polymerised acrylic acid films. The cell sheets are harvested by gentle agitation of the media without the need of any additional external stimulus. We demonstrate that the plasma polymer deposition conditions affect the viability and metabolic activity of the cells in the sheet and relate these effects to the different surface properties of the plasma polymerised acrylic acid films. Based on surface analysis data, a first attempt is made to explain the mechanism behind the cell sheet formation. The advantage of the epithelial cell sheets generated here over single cell suspensions to seed a PLGA scaffold is presented. The scaffold itself, prepared using a mould fabricated via photolithography, exhibits a unique architecture that mimics closely the dimensions of the native tissue (mouse intestine). Copyright 2010 Elsevier Ltd. All rights reserved.

Results of the Greenland ice sheet model initialisation experiments: ISMIP6 - initMIP-Greenland

NASA Astrophysics Data System (ADS)

Goelzer, Heiko; Nowicki, Sophie; Edwards, Tamsin; Beckley, Matthew

2017-04-01

Ice sheet model initialisation has a large effect on projected future sea-level contributions and gives rise to important uncertainties. The goal of this intercomparison exercise for the continental-scale Greenland ice sheet is therefore to compare, evaluate and improve the initialisation techniques used in the ice sheet modelling community. The initMIP-Greenland project is the first in a series of ice sheet model intercomparison activities within ISMIP6 (Ice Sheet Model Intercomparison Project for CMIP6). The experimental set-up has been designed to allow comparison of the initial present-day state of the Greenland ice sheet between participating models and against observations. Furthermore, the initial states are tested with two schematic forward experiments to evaluate the initialisation in terms of model drift (forward run without any forcing) and response to a large perturbation (prescribed surface mass balance anomaly). We present and discuss results that highlight the wide diversity of data sets, boundary conditions and initialisation techniques used in the community to generate initial states of the Greenland ice sheet.

Two-and-one-half-dimensional magnetohydrodynamic simulations of the plasma sheet in the presence of oxygen ions: The plasma sheet oscillation and compressional Pc 5 waves

NASA Astrophysics Data System (ADS)

Lu, Li; Liu, Zhen-Xing; Cao, Jin-Bin

2002-02-01

Two-and-one-half-dimensional magnetohydrodynamic simulations of the multicomponent plasma sheet with the velocity curl term in the magnetic equation are represented. The simulation results can be summarized as follows: (1) There is an oscillation of the plasma sheet with the period on the order of 400 s (Pc 5 range); (2) the magnetic equator is a node of the magnetic field disturbance; (3) the magnetic energy integral varies antiphase with the internal energy integral; (4) disturbed waves have a propagating speed on the order of 10 km/s earthward; (5) the abundance of oxygen ions influences amplitude, period, and dissipation of the plasma sheet oscillation. It is suggested that the compressional Pc 5 waves, which are observed in the plasma sheet close to the magnetic equator, may be caused by the plasma sheet oscillation, or may be generated from the resonance of the plasma sheet oscillation with some Pc 5 perturbation waves coming from the outer magnetosphere.

Application of sintered titanium alloys to metal denture bases: a study of titanium powder sheets for complete denture base.

PubMed

Doi, H; Harrori, M; Hasegawa, K; Yoshinari, M; Kawada, E; Oda, Y

2001-02-01

The purpose of this study was the fabrication of titanium powder sheets to enable the application of sintered titanium alloys as metal denture bases. The effects of titanium particle shape and size, binder content, and plasticizer content on the surface smoothness, tensile strength and elongation of titanium powder sheets was investigated. To select a suitable ratio of powdered metal contents for application as a metal denture base, the effects of aluminum content in Ti sheets and various other powder metal contents in Ti-Al sheets on the density, sintering shrinkage, and bending strength were evaluated. Based on the results of the above experiments, we developed a mixed powder sheet composed of 83Ti-7Al-10Cr with TA45 titanium powder (atomized, -45 microm), and 8 mass% binder content. This titanium alloy sheet had good formability and ductility. Its sintered titanium alloy had a density of 3.2 g/cm3, sintering shrinkage of 3.8%, and bending strength of 403 MPa. The titanium alloy sheet is clinically acceptable for fabricating denture bases.

Ice sheet margins and ice shelves

NASA Technical Reports Server (NTRS)

Thomas, R. H.

1984-01-01

The effect of climate warming on the size of ice sheet margins in polar regions is considered. Particular attention is given to the possibility of a rapid response to warming on the order of tens to hundreds of years. It is found that the early response of the polar regions to climate warming would be an increase in the area of summer melt on the ice sheets and ice shelves. For sufficiently large warming (5-10C) the delayed effects would include the breakup of the ice shelves by an increase in ice drainage rates, particularly from the ice sheets. On the basis of published data for periodic changes in the thickness and melting rates of the marine ice sheets and fjord glaciers in Greenland and Antarctica, it is shown that the rate of retreat (or advance) of an ice sheet is primarily determined by: bedrock topography; the basal conditions of the grounded ice sheet; and the ice shelf condition downstream of the grounding line. A program of satellite and ground measurements to monitor the state of ice sheet equilibrium is recommended.

Monitoring southwest Greenland's ice sheet melt with ambient seismic noise.

PubMed

Mordret, Aurélien; Mikesell, T Dylan; Harig, Christopher; Lipovsky, Bradley P; Prieto, Germán A

2016-05-01

The Greenland ice sheet presently accounts for ~70% of global ice sheet mass loss. Because this mass loss is associated with sea-level rise at a rate of 0.7 mm/year, the development of improved monitoring techniques to observe ongoing changes in ice sheet mass balance is of paramount concern. Spaceborne mass balance techniques are commonly used; however, they are inadequate for many purposes because of their low spatial and/or temporal resolution. We demonstrate that small variations in seismic wave speed in Earth's crust, as measured with the correlation of seismic noise, may be used to infer seasonal ice sheet mass balance. Seasonal loading and unloading of glacial mass induces strain in the crust, and these strains then result in seismic velocity changes due to poroelastic processes. Our method provides a new and independent way of monitoring (in near real time) ice sheet mass balance, yielding new constraints on ice sheet evolution and its contribution to global sea-level changes. An increased number of seismic stations in the vicinity of ice sheets will enhance our ability to create detailed space-time records of ice mass variations.

Computer-aided light sheet flow visualization

NASA Technical Reports Server (NTRS)

Stacy, Kathryn; Severance, Kurt; Childers, Brooks A.

1993-01-01

A computer-aided flow visualization process has been developed to analyze video images acquired from rotating and translating light sheet visualization systems. The computer process integrates a mathematical model for image reconstruction, advanced computer graphics concepts, and digital image processing to provide a quantitative and visual analysis capability. The image reconstruction model, based on photogrammetry, uses knowledge of the camera and light sheet locations and orientations to project two-dimensional light sheet video images into three-dimensional space. A sophisticated computer visualization package, commonly used to analyze computational fluid dynamics (CFD) data sets, was chosen to interactively display the reconstructed light sheet images, along with the numerical surface geometry for the model or aircraft under study. A description is provided of the photogrammetric reconstruction technique, and the image processing and computer graphics techniques and equipment. Results of the computer aided process applied to both a wind tunnel translating light sheet experiment and an in-flight rotating light sheet experiment are presented. The capability to compare reconstructed experimental light sheet images and CFD solutions in the same graphics environment is also demonstrated.

Time Evolution of the Macroscopic Characteristics of a Thin Current Sheet in the Course of Its Formation in the Earth's Magnetotail

NASA Astrophysics Data System (ADS)

Domrin, V. I.; Malova, H. V.; Popov, V. Yu.

2018-04-01

A numerical model is developed that allows tracing the time evolution of a current sheet from a relatively thick current configuration with isotropic distributions of the pressure and temperature in an extremely thin current sheet, which plays a key role in geomagnetic processes. Such a configuration is observed in the Earth's magnetotail in the stage preceding a large-scale geomagnetic disturbance (substorm). Thin current sheets are reservoirs of the free energy released during geomagnetic disturbances. The time evolution of the components of the pressure tensor caused by changes in the structure of the current sheet is investigated. It is shown that the pressure tensor in the current sheet evolves in two stages. In the first stage, a current sheet with a thickness of eight to ten proton Larmor radii forms. This stage is characterized by the plasma drift toward the current sheet and the Earth and can be described in terms of the Chu-Goldberger-Low approximation. In the second stage, an extremely thin current sheet with an anisotropic plasma pressure tensor forms, due to which the system is maintained in an equilibrium state. Estimates of the characteristic time of the system evolution agree with available experimental data.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhamu, Aruna; Shi, Jinjun; Guo, Jiusheng

An electrically conductive laminate composition for fuel cell flow field plate or bipolar plate applications. The laminate composition comprises at least a thin metal sheet having two opposed exterior surfaces and a first exfoliated graphite composite sheet bonded to the first of the two exterior surfaces of the metal sheet wherein the exfoliated graphite composite sheet comprises: (a) expanded or exfoliated graphite and (b) a binder or matrix material to bond the expanded graphite for forming a cohered sheet, wherein the binder or matrix material is between 3% and 60% by weight based on the total weight of the firstmore » exfoliated graphite composite sheet. Preferably, the first exfoliated graphite composite sheet further comprises particles of non-expandable graphite or carbon in the amount of between 3% and 60% by weight based on the total weight of the non-expandable particles and the expanded graphite. Further preferably, the laminate comprises a second exfoliated graphite composite sheet bonded to the second surface of the metal sheet to form a three-layer laminate. Surface flow channels and other desired geometric features can be built onto the exterior surfaces of the laminate to form a flow field plate or bipolar plate. The resulting laminate has an exceptionally high thickness-direction conductivity and excellent resistance to gas permeation.« less

Transfer of fibroblast sheets cultured on thermoresponsive dishes with membranes.

PubMed

Kawecki, Marek; Kraut, Małgorzata; Klama-Baryła, Agnieszka; Łabuś, Wojciech; Kitala, Diana; Nowak, Mariusz; Glik, Justyna; Sieroń, Aleksander L; Utrata-Wesołek, Alicja; Trzebicka, Barbara; Dworak, Andrzej; Szweda, Dawid

2016-06-01

In cell or tissue engineering, it is essential to develop a support for cell-to-cell adhesion, which leads to the generation of cell sheets connected by extracellular matrix. Such supports must be hydrophobic and should result in a detachable cell sheet. A thermoresponsive support that enables the cultured cell sheet to detach using only a change in temperature could be an interesting alternative in regenerative medicine. The aim of this study was to evaluate plates covered with thermoresponsive polymers as supports for the formation of fibroblast sheets and to develop a damage-free procedure for cell sheet transfer with the use of membranes as transfer tools. Human skin fibroblasts were seeded on supports coated with a thermoresponsive polymer: commercial UpCell™ dishes (NUNC™) coated with thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) and dishes coated with thermoresponsive poly(tri(ethylene glycol) monoethyl ether methacrylate) (P(TEGMA-EE)). Confluent fibroblast sheets were effectively cultured and harvested from both commercial PNIPAM-coated dishes and laboratory P(TEGMA-EE)-coated dishes. To transfer a detached cell sheet, two membranes, Immobilon-P(®) and SUPRATHEL(®), were examined. The use of SUPRATHEL for relocating the cell sheets opens a new possibility for the clinical treatment of wounds. This study established the background for implementing thermoresponsive supports for transplanting in vitro cultured fibroblasts.

Fabrication of corneal epithelial cell sheets maintaining colony-forming cells without feeder cells by oxygen-controlled method.

PubMed

Nakajima, Ryota; Takeda, Shizu

2014-01-01

The use of murine 3T3 feeder cells needs to be avoided when fabricating corneal epithelial cell sheets for use in treating ocular surface diseases. However, the expression level of the epithelial stem/progenitor cell marker, p63, is down-regulated in feeder-free culture systems. In this study, in order to fabricate corneal epithelial cell sheets that maintain colony-forming cells without using any feeder cells, we investigated the use of an oxygen-controlled method that was developed previously to fabricate cell sheets efficiently. Rabbit limbal epithelial cells were cultured under hypoxia (1-10% O2) and under normoxia during stratification after reaching confluence. Multilayered corneal epithelial cell sheets were fabricated using an oxygen-controlled method, and immunofluorescence analysis showed that cytokeratin 3 and p63 was expressed in appropriate localization in the cell sheets. The colony-forming efficiency of the cell sheets fabricated by the oxygen-controlled method without feeder cells was significantly higher than that of cell sheets fabricated under 20% O2 without feeder cells. These results indicate that the oxygen-controlled method has the potential to achieve a feeder-free culture system for fabricating corneal epithelial cell sheets for corneal regeneration. Copyright © 2013 Elsevier Ltd. All rights reserved.

Scanning thin-sheet laser imaging microscopy (sTSLIM) with structured illumination and HiLo background rejection.

PubMed Central

Schröter, Tobias J.; Johnson, Shane B.; John, Kerstin; Santi, Peter A.

2011-01-01

We report replacement of one side of a static illumination, dual sided, thin-sheet laser imaging microscope (TSLIM) with an intensity modulated laser scanner in order to implement structured illumination (SI) and HiLo image demodulation techniques for background rejection. The new system is equipped with one static and one scanned light-sheet and is called a scanning thin-sheet laser imaging microscope (sTSLIM). It is an optimized version of a light-sheet fluorescent microscope that is designed to image large specimens (<15 mm in diameter). In this paper we describe the hardware and software modifications to TSLIM that allow for static and uniform light-sheet illumination with SI and HiLo image demodulation. The static light-sheet has a thickness of 3.2 µm; whereas, the scanned side has a light-sheet thickness of 4.2 µm. The scanned side images specimens with subcellular resolution (<1 µm lateral and <4 µm axial resolution) with a size up to 15 mm. SI and HiLo produce superior contrast compared to both the uniform static and scanned light-sheets. HiLo contrast was greater than SI and is faster and more robust than SI because as it produces images in two-thirds of the time and exhibits fewer intensity streaking artifacts. PMID:22254177

Laser Indirect Shock Welding of Fine Wire to Metal Sheet

PubMed Central

Wang, Xiao; Huang, Tao; Luo, Yapeng; Liu, Huixia

2017-01-01

The purpose of this paper is to present an advanced method for welding fine wire to metal sheet, namely laser indirect shock welding (LISW). This process uses silica gel as driver sheet to accelerate the metal sheet toward the wire to obtain metallurgical bonding. A series of experiments were implemented to validate the welding ability of Al sheet/Cu wire and Al sheet/Ag wire. It was found that the use of a driver sheet can maintain high surface quality of the metal sheet. With the increase of laser pulse energy, the bonding area of the sheet/wire increased and the welding interfaces were nearly flat. Energy dispersive spectroscopy (EDS) results show that the intermetallic phases were absent and a short element diffusion layer which would limit the formation of the intermetallic phases emerging at the welding interface. A tensile shear test was used to measure the mechanical strength of the welding joints. The influence of laser pulse energy on the tensile failure modes was investigated, and two failure modes, including interfacial failure and failure through the wire, were observed. The nanoindentation test results indicate that as the distance to the welding interface decreased, the microhardness increased due to the plastic deformation becoming more violent. PMID:28895900

Optimization of Surface Roughness and Wall Thickness in Dieless Incremental Forming Of Aluminum Sheet Using Taguchi

NASA Astrophysics Data System (ADS)

Hamedon, Zamzuri; Kuang, Shea Cheng; Jaafar, Hasnulhadi; Azhari, Azmir

2018-03-01

Incremental sheet forming is a versatile sheet metal forming process where a sheet metal is formed into its final shape by a series of localized deformation without a specialised die. However, it still has many shortcomings that need to be overcome such as geometric accuracy, surface roughness, formability, forming speed, and so on. This project focus on minimising the surface roughness of aluminium sheet and improving its thickness uniformity in incremental sheet forming via optimisation of wall angle, feed rate, and step size. Besides, the effect of wall angle, feed rate, and step size to the surface roughness and thickness uniformity of aluminium sheet was investigated in this project. From the results, it was observed that surface roughness and thickness uniformity were inversely varied due to the formation of surface waviness. Increase in feed rate and decrease in step size will produce a lower surface roughness, while uniform thickness reduction was obtained by reducing the wall angle and step size. By using Taguchi analysis, the optimum parameters for minimum surface roughness and uniform thickness reduction of aluminium sheet were determined. The finding of this project helps to reduce the time in optimising the surface roughness and thickness uniformity in incremental sheet forming.

Data assimilation and prognostic whole ice sheet modelling with the variationally derived, higher order, open source, and fully parallel ice sheet model VarGlaS

NASA Astrophysics Data System (ADS)

Brinkerhoff, D. J.; Johnson, J. V.

2013-07-01

We introduce a novel, higher order, finite element ice sheet model called VarGlaS (Variational Glacier Simulator), which is built on the finite element framework FEniCS. Contrary to standard procedure in ice sheet modelling, VarGlaS formulates ice sheet motion as the minimization of an energy functional, conferring advantages such as a consistent platform for making numerical approximations, a coherent relationship between motion and heat generation, and implicit boundary treatment. VarGlaS also solves the equations of enthalpy rather than temperature, avoiding the solution of a contact problem. Rather than include a lengthy model spin-up procedure, VarGlaS possesses an automated framework for model inversion. These capabilities are brought to bear on several benchmark problems in ice sheet modelling, as well as a 500 yr simulation of the Greenland ice sheet at high resolution. VarGlaS performs well in benchmarking experiments and, given a constant climate and a 100 yr relaxation period, predicts a mass evolution of the Greenland ice sheet that matches present-day observations of mass loss. VarGlaS predicts a thinning in the interior and thickening of the margins of the ice sheet.

Rapid Fabricating Technique for Multi-Layered Human Hepatic Cell Sheets by Forceful Contraction of the Fibroblast Monolayer

PubMed Central

Sakai, Yusuke; Koike, Makiko; Hasegawa, Hideko; Yamanouchi, Kosho; Soyama, Akihiko; Takatsuki, Mitsuhisa; Kuroki, Tamotsu; Ohashi, Kazuo; Okano, Teruo; Eguchi, Susumu

2013-01-01

Cell sheet engineering is attracting attention from investigators in various fields, from basic research scientists to clinicians focused on regenerative medicine. However, hepatocytes have a limited proliferation potential in vitro, and it generally takes a several days to form a sheet morphology and multi-layered sheets. We herein report our rapid and efficient technique for generating multi-layered human hepatic cell (HepaRG® cell) sheets using pre-cultured fibroblast monolayers derived from human skin (TIG-118 cells) as a feeder layer on a temperature-responsive culture dish. Multi-layered TIG-118/HepaRG cell sheets with a thick morphology were harvested on day 4 of culturing HepaRG cells by forceful contraction of the TIG-118 cells, and the resulting sheet could be easily handled. In addition, the human albumin and alpha 1-antitrypsin synthesis activities of TIG-118/HepaRG cells were approximately 1.2 and 1.3 times higher than those of HepaRG cells, respectively. Therefore, this technique is considered to be a promising modality for rapidly fabricating multi-layered human hepatocyte sheets from cells with limited proliferation potential, and the engineered cell sheet could be used for cell transplantation with highly specific functions. PMID:23923035

Human platelet lysate supports the formation of robust human periodontal ligament cell sheets.

PubMed

Tian, Bei-Min; Wu, Rui-Xin; Bi, Chun-Sheng; He, Xiao-Tao; Yin, Yuan; Chen, Fa-Ming

2018-04-01

The use of stem cell-derived sheets has become increasingly common in a wide variety of biomedical applications. Although substantial evidence has demonstrated that human platelet lysate (PL) can be used for therapeutic cell expansion, either as a substitute for or as a supplement to xenogeneic fetal bovine serum (FBS), its impact on cell sheet production remains largely unexplored. In this study, we manufactured periodontal ligament stem cell (PDLSC) sheets in vitro by incubating PDLSCs in sheet-induction media supplemented with various ratios of PL and FBS, i.e. 10% PL without FBS, 7.5% PL + 2.5% FBS, 5% PL + 5% FBS, 2.5% PL + 7.5% FBS or 10% FBS without PL. Cultures with the addition of all the designed supplements led to successful cell sheet production. In addition, all the resultant cellular materials exhibited similar expression profiles of matrix-related genes and proteins, such as collagen I, fibronectin and integrin β1. Interestingly, the cell components within sheets generated by media containing both PL and FBS exhibited improved osteogenic potential. Following in vivo transplantation, all sheets supported significant new bone formation. Our data suggest that robust PDLSC sheets can be produced by applying PL as either an alternative or an adjuvant to FBS. Further examination of the relevant influences of human PL that benefit cell behaviour and matrix production will pave the way towards optimized and standardized conditions for cell sheet production. Copyright © 2017 John Wiley & Sons, Ltd.

Cartilage engineering using chondrocyte cell sheets and its application in reconstruction of microtia.

PubMed

Zhou, Libin; Ding, Ruiying; Li, Baowei; Han, Haolun; Wang, Hongnan; Wang, Gang; Xu, Bingxin; Zhai, Suoqiang; Wu, Wei

2015-01-01

The imperfections of scaffold materials have hindered the clinical application of cartilage tissue engineering. The recently developed cell-sheet technique is adopted to engineer tissues without scaffold materials, thus is considered being potentially able to overcome the problems concerning the scaffold imperfections. This study constructed monolayer and bilayer chondrocyte cell sheets and harvested the sheets with cell scraper instead of temperature-responsive culture dishes. The properties of the cultured chondrocyte cell sheets and the feasibility of cartilage engineering using the chondrocyte cell sheets was further investigated via in vitro and in vivo study. Primary extracellular matrix (ECM) formation and type II collagen expression was detected in the cell sheets during in vitro culture. After implanted into nude mice for 8 weeks, mature cartilage discs were harvested. The morphology of newly formed cartilage was similar in the constructs originated from monolayer and bilayer chondrocyte cell sheet. The chondrocytes were located within evenly distributed ovoid lacunae. Robust ECM formation and intense expression of type II collagen was observed surrounding the evenly distributed chondrocytes in the neocartilages. Biochemical analysis showed that the DNA contents of the neocartilages were higher than native human costal cartilage; while the contents of the main component of ECM, glycosaminoglycan and hydroxyproline, were similar to native human costal cartilage. In conclusion, the chondrocyte cell sheet constructed using the simple and low-cost technique is basically the same with the cell sheet cultured and harvested in temperature-responsive culture dishes, and can be used for cartilage tissue engineering.

Antifibrotic effect of dexamethasone/alginate-coated silicone sheet in the abraded middle ear mucosa.

PubMed

Jang, Chul Ho; Ahn, Seung Hyun; Kim, Geun Hyung

2016-12-01

Silicone sheet is a material which is commonly used in middle ear surgery to prevent the formation of adhesions between the tympanic membrane and the medial bony wall of the middle ear cavity. However, silicone sheet can induce a tight and hard fibrous capsule in the region of the stapes, and this is particularly common in cases of eustachian tube dysfunction. As a result of the fibrous encapsulation around the silicone sheet, postoperative aeration of the stapes can be interrupted causing poor hearing gain. In this study, we performed an in vitro and in vivo evaluation of the antifibrotic effects of a dexamethasone and alginate (Dx/alginate) coating on silicone sheet. The Dx/alginate-coated silicone sheets were fabricated using a plasma-treatment and coating method. The Dx/alginate-coated silicone sheets effectively limited in vitro fibroblast attachment and proliferation due to the controlled release of Dx, which can be modified by manipulation of the alginate coating. For the in-vivo evaluation, guinea pigs (albino, male, weighing 250g) were divided into two groups, with the control group (n=5) implanted with silicone sheet and the test group (n=5) receiving Dx/alginate-coated silicone sheet. Animals were sacrificed 3 weeks after implantation, and histological analysis was performed using hematoxylin and eosin (H&E) and immunohistochemical staining techniques. Dx/alginate-coated silicone sheets showed marked inhibition of fibrosis in both the in vitro and in vivo studies. Silicone sheet that incorporates a Dx/alginate coating can release Dx and inhibit fibrosis in the middle ear. This material could be utilized in middle ear surgery as a means of preserving proper aeration and hearing gain following ossiculoplasty. Copyright © 2016 Elsevier B.V. All rights reserved.

Microstructure evolution of a dissimilar junction interface between an Al sheet and a Ni-coated Cu sheet joined by magnetic pulse welding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Itoi, Takaomi, E-mail: itoi@faculty.chiba-u.jp

An Al sheet and a Ni-coated Cu sheet were lap joined by using magnetic pulse welding (MPW). Tensile tests were performed on the joined sheets, and a good lap joint was achieved at a discharge energy of > 0.9 kJ. The weld interface exhibited a wavy morphology and an intermediate layer along the weld interface. Microstructure observations of the intermediate layer revealed that the Ni coating region consisted of a Ni–Al binary amorphous alloy and that the Al sheet region contained very fine Al nanograins. Ni fragments indicative of unmelted residual Ni from the coating were also observed in partsmore » of the intermediate layer. Formation of these features can be attributed to localize melting and a subsequent high rate cooling of molten Al and Ni confined to the interface during the MPW process. In the absence of an oxide film, atomic-scale bonding was also achieved between the intermediate layer and the sheet surfaces after the collision. MPW utilises impact energy, which affects the sheet surfaces. From the obtained results, good lap joint is attributed to an increased contact area, the anchor effect, work hardening, the absence of an oxide film, and suppressed formation of intermetallic compounds at the interface. - Highlights: •Good lap joint of an Al sheet and a Ni-coated Cu sheet was achieved by using magnetic pulse welding. •A Ni–Al binary amorphous alloy was formed as an intermediate layer at weld interface. •Atomic-scale bonding was achieved between the intermediate layer and the sheet surfaces.« less

Greenland Ice Sheet Surface Temperature, Melt, and Mass Loss: 2000-2006

NASA Technical Reports Server (NTRS)

Hall, Dorothy K.; Williams, Richard S., Jr.; Luthcke, Scott B.; DiGirolamo, Nocolo

2007-01-01

Extensive melt on the Greenland Ice Sheet has been documented by a variety of ground and satellite measurements in recent years. If the well-documented warming continues in the Arctic, melting of the Greenland Ice Sheet will likely accelerate, contributing to sea-level rise. Modeling studies indicate that an annual or summer temperature rise of 1 C on the ice sheet will increase melt by 20-50% therefore, surface temperature is one of the most important ice-sheet parameters to study for analysis of changes in the mass balance of the ice-sheet. The Greenland Ice Sheet contains enough water to produce a rise in eustatic sea level of up to 7.0 m if the ice were to melt completely. However, even small changes (centimeters) in sea level would cause important economic and societal consequences in the world's major coastal cities thus it is extremely important to monitor changes in the ice-sheet surface temperature and to ultimately quantify these changes in terms of amount of sea-level rise. We have compiled a high-resolution, daily time series of surface temperature of the Greenland Ice Sheet, using the I-km resolution, clear-sky land-surface temperature (LST) standard product from the Moderate-Resolution Imaging Spectroradiometer (MODIS), from 2000 - 2006. We also use Gravity Recovery and Climate Experiment (GRACE) data, averaged over 10-day periods, to measure change in mass of the ice sheet as it melt and snow accumulates. Surface temperature can be used to determine frequency of surface melt, timing of the start and the end of the melt season, and duration of melt. In conjunction with GRACE data, it can also be used to analyze timing of ice-sheet mass loss and gain.

Antarctic ice sheet thickness estimation using the horizontal-to-vertical spectral ratio method with single-station seismic ambient noise

NASA Astrophysics Data System (ADS)

Yan, Peng; Li, Zhiwei; Li, Fei; Yang, Yuande; Hao, Weifeng; Bao, Feng

2018-03-01

We report on a successful application of the horizontal-to-vertical spectral ratio (H / V) method, generally used to investigate the subsurface velocity structures of the shallow crust, to estimate the Antarctic ice sheet thickness for the first time. Using three-component, five-day long, seismic ambient noise records gathered from more than 60 temporary seismic stations located on the Antarctic ice sheet, the ice thickness measured at each station has comparable accuracy to the Bedmap2 database. Preliminary analysis revealed that 60 out of 65 seismic stations on the ice sheet obtained clear peak frequencies (f0) related to the ice sheet thickness in the H / V spectrum. Thus, assuming that the isotropic ice layer lies atop a high velocity half-space bedrock, the ice sheet thickness can be calculated by a simple approximation formula. About half of the calculated ice sheet thicknesses were consistent with the Bedmap2 ice thickness values. To further improve the reliability of ice thickness measurements, two-type models were built to fit the observed H / V spectrum through non-linear inversion. The two-type models represent the isotropic structures of single- and two-layer ice sheets, and the latter depicts the non-uniform, layered characteristics of the ice sheet widely distributed in Antarctica. The inversion results suggest that the ice thicknesses derived from the two-layer ice models were in good concurrence with the Bedmap2 ice thickness database, and that ice thickness differences between the two were within 300 m at almost all stations. Our results support previous finding that the Antarctic ice sheet is stratified. Extensive data processing indicates that the time length of seismic ambient noise records can be shortened to two hours for reliable ice sheet thickness estimation using the H / V method. This study extends the application fields of the H / V method and provides an effective and independent way to measure ice sheet thickness in Antarctica.

Experimental Study of Deformation and of Effective Width in Axially Loaded Sheet-stringer Panels

NASA Technical Reports Server (NTRS)

Ramberg, Walter; MCPHERSON ALBERT E; Levy, Sam

1939-01-01

The deformation of two sheet-stringer panels subjected to end compression under carefully controlled end conditions was measured at a number of points and at a number of loads, most of which were above the load at which the sheet had begun to buckle. The two panels were identical except for the sheet, which was 0.70-inch 24st alclad for specimen 1 and 0.025-inch 24st aluminum alloy for specimen 6. A technique was developed for attaching Tuckerman optical strain gauges to the sheet without disturbing the strain distribution in the sheet by the method of attachment. This technique was used to explore the strain distribution in the sheet at various loads. The twisting and the bending of the stringers was measured by means of pointers attached to the stringers. The shape of the buckles in the sheet of specimen 6 was recorded at two loads by means of plaster casts. The sheet and the stringer loads at failure are compared with the corresponding loads for five similar panels tested at the Navy Model Basin. A detailed comparison is made between the measured deformation of the buckled sheet and the deformation calculated from approximate theories for the deformation in a rectangular sheet with freely supported edges buckling under end compression advanced by Timoshenko, Frankland, and Marguerre. The measured effective width for the specimens is compared with the effective width given by nine different relations for effective width as a function of the edge stress divided by the buckling stress of the sheet. The analysis of the measured stringer deformation is confined to an application of Southwell's method of plotting deformation against deformation over load. It was concluded that the stringer failure in both specimens were due to an instability in which the stringer was simultaneously twisted and bent as a column.

Modelled Growth and Decay of the Cordilleran Ice Sheet Through the Last Glacial Cycle

NASA Astrophysics Data System (ADS)

Marshall, S. J.; Banwell, A.

2015-12-01

The Cordilleran Ice Sheet in western North America had an enigmatic evolution during the last glacial cycle, developing out of sync with the larger Laurentide and global glaciation. The geological record suggests that the ice sheet emerged late, ca. 45 ka, growing to be a fully-established ice sheet in isotope stages 3 and 2 and deglaciating late in the glacial cycle. This has been a challenge to model, and is a paleoclimatic curiosity, because the western Cordillera of North America is heavily glacierized today, and one would intuitively expect it to act as an inception centre for the Pleistocene ice sheets. The region receives heavy precipitation, and modest cooling should induce large-scale glacier expansion. Indeed, a Cordilleran Ice Sheet quickly nucleates in isotope substage 5d in most ice sheet modeling studies to date, and is a resilient feature throughout the glaciation. The fact that a full-scale Cordilleran Ice Sheet did not develop until relatively late argues for either: (a) ice sheet models that have been inadequate in resolving the process of alpine-style glaciation, i.e., the coalescence of alpine icefields, or (b) a climatic history in western North America that deviated strongly from the hemispheric-scale cooling which drove the growth of the Laurentide and Scandinavian Ice Sheets, as recorded in Greenland. We argue that reasonable reconstructions of Cordilleran Ice Sheet growth and decay implicate a combination of these two considerations. Sufficient model resolution is required to capture the valley-bottom melt that suppresses icefield coalescence, while early-glacial cooling must have been modest in the Pacific sector of North America. We argue for a persistent warm, dry climate relative to that in eastern North America and the Atlantic sector, likely associated with positive feedbacks between atmospheric circulation and the nascent Laurentide Ice Sheet (i.e., peristent circulation patterns similar to those of 2014-2015). This must have been disrupted as the Laurentide thickened and advanced southward, allowing the Cordilleran Ice Sheet to emerge from numerous isolated icefield complexes.

Sheet Probability Index (SPI): Characterizing the geometrical organization of the white matter with diffusion MRI

PubMed Central

Tax, Chantal M.W.; Haije, Tom Dela; Fuster, Andrea; Westin, Carl-Fredrik; Viergever, Max A.; Florack, Luc; Leemans, Alexander

2017-01-01

The question whether our brain pathways adhere to a geometric grid structure has been a popular topic of debate in the diffusion imaging and neuroscience society. Wedeen et al. (2012a b) proposed that the brain’s white matter is organized like parallel sheets of interwoven pathways. Catani et al. (2012) concluded that this grid pattern is most likely an artifact, resulting from methodological biases that cause the tractography pathways to cross in orthogonal angles. To date, ambiguities in the mathematical conditions for a sheet structure to exist (e.g. its relation to orthogonal angles) combined with the lack of extensive quantitative evidence have prevented wide acceptance of the hypothesis. In this work, we formalize the relevant terminology and recapitulate the condition for a sheet structure to exist. Note that this condition is not related to the presence or absence of orthogonal crossing fibers, and that sheet structure is defined formally as a surface formed by two sets of interwoven pathways intersecting at arbitrary angles within the surface. To quantify the existence of sheet structure, we present a novel framework to compute the sheet probability index (SPI), which reflects the presence of sheet structure in discrete orientation data (e.g. fiber peaks derived from diffusion MRI). With simulation experiments we investigate the effect of spatial resolution, curvature of the fiber pathways, and measurement noise on the ability to detect sheet structure. In real diffusion MRI data experiments we can identify various regions where the data supports sheet structure (high SPI values), but also areas where the data does not support sheet structure (low SPI values) or where no reliable conclusion can be drawn. Several areas with high SPI values were found to be consistent across subjects, across multiple data sets obtained with different scanners, resolutions, and degrees of diffusion weighting, and across various modeling techniques. Under the strong assumption that the diffusion MRI peaks reflect true axons, our results would therefore indicate that pathways do not form sheet structures at every crossing fiber region but instead at well-defined locations in the brain. With this framework, sheet structure location, extent, and orientation could potentially serve as new structural features of brain tissue. The proposed method can be extended to quantify sheet structure in directional data obtained with techniques other than diffusion MRI, which is essential for further validation. PMID:27456538

Collective epithelial cell sheet adhesion and migration on polyelectrolyte multilayers with uniform and gradients of compliance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martinez, Jessica S.; Schlenoff, Joseph B.; Keller, Thomas C.S., E-mail: tkeller@bio.fsu.edu

Polyelectrolyte multilayers (PEMUs) are tunable thin films that could serve as coatings for biomedical implants. PEMUs built layer by layer with the polyanion poly(acrylic acid) (PAA) modified with a photosensitive 4-(2-hydroxyethoxy) benzophenone (PAABp) group and the polycation poly(allylamine hydrochloride) (PAH) are mechanically tunable by UV irradiation, which forms covalent bonds between the layers and increases PEMU stiffness. PAH-terminated PEMUs (PAH-PEMUs) that were uncrosslinked, UV-crosslinked to a uniform stiffness, or UV-crosslinked with an edge mask or through a neutral density optical gradient filter to form continuous compliance gradients were used to investigate how differences in PEMU stiffness affect the adhesion andmore » migration of epithelial cell sheets from scales of the fish Poecilia sphenops (Black Molly) and Carassius auratus (Comet Goldfish). During the progressive collective cell migration, the edge cells (also known as ‘leader’ cells) in the sheets on softer uncrosslinked PEMUs and less crosslinked regions of the gradient formed more actin filaments and vinculin-containing adherens junctions and focal adhesions than formed in the sheet cells on stiffer PEMUs or glass. During sheet migration, the ratio of edge cell to internal cell (also known as ‘follower’ cells) motilities were greater on the softer PEMUs than on the stiffer PEMUs or glass, causing tension to develop across the sheet and periods of retraction, during which the edge cells lost adhesion to the substrate and regions of the sheet retracted toward the more adherent internal cell region. These retraction events were inhibited by the myosin II inhibitor Blebbistatin, which reduced the motility velocity ratios to those for sheets on the stiffer PEMUs. Blebbistatin also caused disassembly of actin filaments, reorganization of focal adhesions, increased cell spreading at the leading edge, as well as loss of edge cell-cell connections in epithelial cell sheets on all surfaces. Interestingly, cells throughout the interior region of the sheets on uncrosslinked PEMUs retained their actin and vinculin organization at adherens junctions after treatment with Blebbistatin. Like Blebbistatin, a Rho-kinase (ROCK) inhibitor, Y27632, promoted loss of cell-cell connections between edge cells, whereas a Rac1 inhibitor, NSC23766, primarily altered the lamellipodial protrusion in edge cells. Compliance gradient PAH-PEMUs promoted durotaxis of the cell sheets but not of individual keratocytes, demonstrating durotaxis, like plithotaxis, is an emergent property of cell sheet organization. - Highlights: • Fish scale cell sheets migrate on PAH-PAABp polyelectrolyte multilayers. • Sheets migrating on softer PEMUs periodically retract. • Sheets durotax on modulus gradients. • Myosin II inhibitors inhibit sheet integrity and migration.« less

Mycobacterium Avium Complex (MAC)

MedlinePlus

... Sheet Categories Internet Bookmarks on AIDS Have Questions? Printing & Downloading Fact Sheets Permission to Use Fact Sheets Sponsors and Advertising Privacy Policy Project Staff Contact Us This site ...

The Effective Width of Curved Sheet After Buckling

NASA Technical Reports Server (NTRS)

Wenzek, W A

1938-01-01

This report describes experiments made for the purpose of ascertaining the effective width of circularly curved sheet under pure flexural stress. A relation for the effective width of curved sheets is established. Experiments were made with circular cylinders compressed in longitudinal direction. The sheets were rigidly built in at the sides parallel to the axis of the cylinder.

Manifold free multiple sheet superplastic forming

DOEpatents

Elmer, John W.; Bridges, Robert L.

2001-01-01

Fluid-forming compositions in a container attached to enclosed adjacent sheets are heated to relatively high temperatures to generate fluids (gases) that effect inflation of the sheets. Fluid rates to the enclosed space between the sheets can be regulated by the canal from the container. Inflated articles can be produced by a continuous, rather than batch-type, process.

Spina Bifida: General Information. Fact Sheet Number 12 = La Espina Bifida: Informacion General. Fact Sheet Number 12.

ERIC Educational Resources Information Center

National Information Center for Children and Youth with Disabilities, Washington, DC.

This fact sheet offers definitions of the three types of spina bifida, outlines their incidence, describes characteristics of individuals with spina bifida, and reviews educational implications. The fact sheet emphasizes that school programs should be flexible to accommodate these students' special needs and frequent absences, that children with…

Exploring Deliberate Practice & the Use of Skill Sheets in the Collegiate Leadership Competition

ERIC Educational Resources Information Center

Allen, Scott J.; Jenkins, Daniel M.; Krizanovic, Bela

2018-01-01

Little has been written about the use of skill sheets in leadership education and this paper demonstrates how they have been implemented in one specific context. Used in a number of domains (e.g., karate, cardiopulmonary resuscitation) skill sheets are checklists or rubrics that record skill performance. The use of skill sheets in leadership…

76 FR 1135 - Polyethylene Terephthalate Film, Sheet, and Strip From the Republic of Korea: Final Results of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-07

... Film, Sheet, and Strip From the Republic of Korea: Final Results of the Expedited Third Five-Year...) initiated the third sunset review of the antidumping duty order on polyethylene terephthalate film, sheet... order on polyethylene terephthalate film, sheet, and strip from the Republic of Korea, pursuant to...

75 FR 10774 - Certain Coated Paper Suitable For High-Quality Print Graphics Using Sheet-Fed Presses from the...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-09

... Suitable For High-Quality Print Graphics Using Sheet-Fed Presses from the People's Republic of China...-quality print graphics using sheet-fed presses from the People's Republic of China (``PRC''). For... Graphics Using Sheet-Fed Presses from the People's Republic of China: Initiation of Countervailing Duty...

76 FR 71512 - Polyethylene Terephthalate Film, Sheet, and Strip From Korea: Final Results of Antidumping Duty...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-18

... Film, Sheet, and Strip From Korea: Final Results of Antidumping Duty Administrative Review and... terephthalate film, sheet, and strip (PET film) from Korea, covering the June 1, 2009, to May 31, 2010, period of review (POR).\\1\\ \\1\\ See Polyethylene Terephthalate Film, Sheet, and Strip from the Republic of...

76 FR 12938 - Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of Time Limit for Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-09

... Film, Sheet and Strip From India: Extension of Time Limit for Final Results of Countervailing Duty New... terephthalate film, sheet and strip from India for SRF Limited (SRF), covering the period January 1, 2009, through December 31, 2009. See Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary...

76 FR 12937 - Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of Time Limit for Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-09

... Film, Sheet and Strip From India: Extension of Time Limit for Final Results of Antidumping Duty New... terephthalate film, sheet and strip from India for SRF Limited (SRF) covering the period July 1, 2009, through December 31, 2009. See Polyethylene Terephthalate Film, Sheet and Strip from India: Preliminary Results of...

Aircraft Sheet Metal Practices; Sheet Metal Work 2: 9855.01.

ERIC Educational Resources Information Center

Dade County Public Schools, Miami, FL.

The course outline will serve as a guide to the 11th grade student interested in sheet metal occupations. Requiring 135 clock hours, the basic course covers orientation and techniques in aircraft sheet metal. Emphasis will be placed on the proper use of tools and machines, safety, fabrication methods, aircraft materials, basic layout, and special…

17 CFR 210.6-06 - Special provisions applicable to the balance sheets of issuers of face-amount certificates.

Code of Federal Regulations, 2011 CFR

2011-04-01

... to the balance sheets of issuers of face-amount certificates. 210.6-06 Section 210.6-06 Commodity and... balance sheets of issuers of face-amount certificates. Balance sheets filed by issuers of face-amount... balances. 3. Receivables. (a) State separately amounts receivable from (1) sales of investments; (2...

17 CFR 210.6-06 - Special provisions applicable to the balance sheets of issuers of face-amount certificates.

Code of Federal Regulations, 2010 CFR

2010-04-01

... to the balance sheets of issuers of face-amount certificates. 210.6-06 Section 210.6-06 Commodity and... balance sheets of issuers of face-amount certificates. Balance sheets filed by issuers of face-amount... balances. 3. Receivables. (a) State separately amounts receivable from (1) sales of investments; (2...

Manifold free multiple sheet superplastic forming

DOEpatents

Elmer, John W.; Bridges, Robert L.

2004-01-13

Fluid-forming compositions in a container attached to enclosed adjacent sheets are heated to relatively high temperatures to generate fluids (gases) that effect inflation of the sheets. Fluid rates to the enclosed space between the sheets can be regulated by the canal from the container. Inflated articles can be produced by a continuous, rather than batch-type, process.

75 FR 59744 - Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-28

...)] Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan AGENCY: United States... duty orders on stainless steel sheet and strip from Germany, Italy, Japan, Korea, Mexico, and Taiwan... stainless steel sheet and strip from Germany, Italy, Japan, Korea, Mexico, and Taiwan would be likely to...

76 FR 46323 - Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-02

...)] Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan Determination On the... antidumping duty orders on stainless steel sheet and strip from Japan, Korea, and Taiwan \\3\\ would be likely... Commissioner Daniel R. Pearson dissenting with respect to stainless steel sheet and strip from Japan, Korea...

Machine Shop Suggested Job and Task Sheets. Part II. 21 Advanced Jobs.

ERIC Educational Resources Information Center

Texas A and M Univ., College Station. Vocational Instructional Services.

This volume consists of advanced job and task sheets adaptable for use in the regular vocational industrial education programs for the training of machinists and machine shop operators. Twenty-one advanced machine shop job sheets are included. Some or all of this material is provided for each job: an introductory sheet with aim, checking…

33 CFR 150.627 - Must material safety data sheets be available to all personnel?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Must material safety data sheets... Health Hazard Communication Program § 150.627 Must material safety data sheets be available to all personnel? (a) The person in charge must ensure that a material safety data sheet (MSDS) for each hazardous...

33 CFR 150.627 - Must material safety data sheets be available to all personnel?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Must material safety data sheets... Health Hazard Communication Program § 150.627 Must material safety data sheets be available to all personnel? (a) The person in charge must ensure that a material safety data sheet (MSDS) for each hazardous...

33 CFR 150.627 - Must material safety data sheets be available to all personnel?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Must material safety data sheets... Health Hazard Communication Program § 150.627 Must material safety data sheets be available to all personnel? (a) The person in charge must ensure that a material safety data sheet (MSDS) for each hazardous...

33 CFR 150.627 - Must material safety data sheets be available to all personnel?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Must material safety data sheets... Health Hazard Communication Program § 150.627 Must material safety data sheets be available to all personnel? (a) The person in charge must ensure that a material safety data sheet (MSDS) for each hazardous...

Dimensional Analysis and Electric Potential Due to a Uniformly Charged Sheet

ERIC Educational Resources Information Center

Aghamohammadi, Amir

2011-01-01

Dimensional analysis, superposition principle, and continuity of electric potential are used to study the electric potential of a uniformly charged square sheet on its plane. It is shown that knowing the electric potential on the diagonal and inside the square sheet is equivalent to knowing it everywhere on the plane of the square sheet. The…

21 CFR 880.5180 - Burn sheet.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Burn sheet. 880.5180 Section 880.5180 Food and... Burn sheet. (a) Identification. A burn sheet is a device made of a porous material that is wrapped aroung a burn victim to retain body heat, to absorb wound exudate, and to serve as a barrier against...

21 CFR 880.5180 - Burn sheet.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Burn sheet. 880.5180 Section 880.5180 Food and... Burn sheet. (a) Identification. A burn sheet is a device made of a porous material that is wrapped aroung a burn victim to retain body heat, to absorb wound exudate, and to serve as a barrier against...

21 CFR 880.5180 - Burn sheet.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Burn sheet. 880.5180 Section 880.5180 Food and... Burn sheet. (a) Identification. A burn sheet is a device made of a porous material that is wrapped aroung a burn victim to retain body heat, to absorb wound exudate, and to serve as a barrier against...

21 CFR 880.5180 - Burn sheet.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Burn sheet. 880.5180 Section 880.5180 Food and... Burn sheet. (a) Identification. A burn sheet is a device made of a porous material that is wrapped aroung a burn victim to retain body heat, to absorb wound exudate, and to serve as a barrier against...

21 CFR 880.5180 - Burn sheet.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Burn sheet. 880.5180 Section 880.5180 Food and... Burn sheet. (a) Identification. A burn sheet is a device made of a porous material that is wrapped aroung a burn victim to retain body heat, to absorb wound exudate, and to serve as a barrier against...

Crib Sheets and Exam Performance in a Data Structures Course

ERIC Educational Resources Information Center

Hamouda, Sally; Shaffer, Clifford A.

2016-01-01

In this paper, we study the relationship between the use of "crib sheets" or "cheat sheets" and performance on in-class exams. Our extensive survey of the existing literature shows that it is not decisive on the questions of when or whether crib sheets actually help students to either perform better on an exam or better learn…

Dynamics of poroelastocapillary rise

NASA Astrophysics Data System (ADS)

Nasouri, Babak; Elfring, Gwynn

2017-11-01

The surface-tension-driven rise of a liquid between two elastic sheets can result in their deformation or coalescence depending on their flexibility. When the sheets are poroelastic, the flexibility of the immersed parts of the sheets can change considerably thereby altering the dynamical behavior of the system. To better understand this phenomenon, we study the poroelastocapillary rise of a wetting liquid between poroelastic sheets. Using the lubrication theory and linear elasticity, we quantify the effects of the change in material properties of the wet sheets on the capillary rise and the equilibrium state of the system.

Fluid Dynamic and Stability Analysis of a Thin Liquid Sheet

NASA Technical Reports Server (NTRS)

McMaster, Matthew S.

1992-01-01

Interest in thin sheet flows has recently been renewed due to their potential application in space radiators. Theoretical and experimental studies of the fluid dynamics and stability of thin liquid sheet flows have been carried out in this thesis. A computer program was developed to determine the cross-sectional shape of the edge cylinder given the cross-sectional area of the edge cylinder. A stability analysis was performed on a non-planer liquid sheet. A study was conducted to determine the effects of air resistance on the sheet.

How To Cut a Round and a Square Inside Opening in a Piece of Sheet Metal Using Aviation Snips. Sheet Metal 1-001. Lesson Plan No. 2.

ERIC Educational Resources Information Center

Shibayama, Guy T.

As part of a 90-hour community college course in sheet metal working, this 50-minute lesson was designed to enable a student to: (1) identify and use right and left hand aviation snips; (2) cut out a 6-inch round opening in a piece of sheet metal using aviation snips; and (3) cut out a 6-by-6 inch square opening in a piece of sheet metal using…

Preparation of multilayer graphene sheets and their applications for particle accelerators

NASA Astrophysics Data System (ADS)

Tatami, Atsushi; Tachibana, Masamitsu; Yagi, Takashi; Murakami, Mutsuaki

2018-05-01

Multilayer graphene sheets were prepared by heat treatment of polyimide films at temperatures of up to 3000 °C. The sheets consist of highly oriented graphite layers with excellent mechanical robustness and flexibility. Key features of these sheets include their high thermal conductivity in the in-plane direction, good mechanical properties, and high carbon purity. The results suggest that the multilayer graphene sheets have great potential for charge stripping foils that persist even under the highest ion beam intensities irradiation and can be used for accelerator applications.

Bipolar battery plate

NASA Technical Reports Server (NTRS)

Rowlette, John J. (Inventor)

1987-01-01

A liquid-impermeable plate (10) having through-plate conductivity with essentially zero resistance comprises an insulator sheet (12) having a series of spaced perforations (14) each of which contains a metal element (16) sealingly received into the perforation (14). A low-cost plate can readily be manufactured by punching a thermoplastic sheet (40) such as polypropylene with a punching tool (52), filling the apertures with led spheres (63) having a diameter smaller than the holes (50) but larger than the thickness of the sheet, sweeping excess spheres (62) off the sheet with a doctor blade (60) and then pressing a heated platen (74) onto the sheet to swage the spheres into a cylindrical shape and melt the surrounding resin to form a liquid-impermeable collar (4) sealing the metal into the sheet.

Bipolar battery plate

NASA Technical Reports Server (NTRS)

Rowlette, John J. (Inventor)

1985-01-01

A liquid-impermeable plate (10) having throughplate conductivity with essentially zero resistance comprises an insulator sheet (12) having a series of spaced perforations (14) each of which contains a metal element (16) sealingly received into the perforation (14). A low-cost plate can readily be manufactured by punching a thermoplastic sheet (40) such as polypropylene with a punching tool (52), filling the apertures with lead spheres (63) having a diameter smaller than the holes (50) but larger than the thickness of the sheet, sweeping excess spheres (62) off the sheet with a doctor blade (60) and then pressing a heated platen (74) onto the sheet to swage the spheres into a cylindrical shape and melt the surrounding resin to form a liquid-impermeable collar (4) sealing the metal into the sheet.

Fabrication method for cores of structural sandwich materials including star shaped core cells

DOEpatents

Christensen, R.M.

1997-07-15

A method for fabricating structural sandwich materials having a core pattern which utilizes star and non-star shaped cells is disclosed. The sheets of material are bonded together or a single folded sheet is used, and bonded or welded at specific locations, into a flat configuration, and are then mechanically pulled or expanded normal to the plane of the sheets which expand to form the cells. This method can be utilized to fabricate other geometric cell arrangements than the star/non-star shaped cells. Four sheets of material (either a pair of bonded sheets or a single folded sheet) are bonded so as to define an area therebetween, which forms the star shaped cell when expanded. 3 figs.

The Pleistocene evolution of the East Antarctic Ice Sheet in the Prydz bay region: Stable isotopic evidence from ODP Site 1167

USGS Publications Warehouse

Theissen, K.M.; Dunbar, R.B.; Cooper, A. K.; Mucciarone, D.A.; Hoffmann, D.

2003-01-01

Ocean Drilling Program Leg 188, Prydz Bay, East Antarctica is part of a larger initiative to explore the Cenozoic history of the Antarctic Ice Sheet through direct drilling and sampling of the continental margins. In this paper, we present stable isotopic results from Ocean Drilling Program (ODP) Site 1167 located on the Prydz Channel Trough Mouth Fan (TMF), the first Antarctic TMF to be drilled. The foraminifer-based ??18O record is interpreted along with sedimentary and downhole logging evidence to reconstruct the Quaternary glacial history of Prydz Bay and the adjacent Lambert Glacier Amery Ice Shelf System (LGAISS). We report an electron spin resonance age date of 36. 9 ?? 3.3 ka at 0.45 m below sea floor and correlate suspected glacial-interglacial cycles with the global isotopic stratigraphy to improve the chronology for Site 1167. The ??18O record based on planktonic (Neogloboquadrina pachyderma (s.)) and limited benthic results (Globocassidulina crassa), indicates a trend of ice sheet expansion that was interrupted by a period of reduced ice volume and possibly warmer conditions during the early-mid-Pleistocene (0.9-1.38 Ma). An increase in ?? 18O values after ??? 900 ka appears to coincide with the mid-Pleistocene climate transition and the expansion of the northern hemisphere ice sheet. The ??18O record in the upper 50 m of the stratigraphic section indicates as few as three glacial-interglacial cycles, tentatively assigned as marine isotopic stages (MIS) 16-21, are preserved since the Brunhes/Matuyama paleomagnetic reversal (780 ka). This suggests that there is a large unconformity near the top of the section and/or that there may have been few extreme advances of the ice sheet since the mid-Pleistocene climate transition resulting in lowered sedimentation rates on the Prydz Channel TMF. The stable isotopic record from Site 1167 is one of the few available from the area south of the Antarctic Polar Front that has been linked with the global isotopic stratigraphy. Our results suggest the potential for the recovery of useful stable isotopic records in other TMFs. ?? 2003 Elsevier B.V. All rights reserved.

Final NPDES Electronic Reporting Rule Fact Sheet

EPA Pesticide Factsheets

Fact sheet explaining the National Pollution Discharge Elimination System (NPDES) Electronic Reporting Rule. The fact sheet provides information on the purpose of the rule, benefits and implementation.

An Amino Acid Code for β-sheet Packing Structure

PubMed Central

Joo, Hyun; Tsai, Jerry

2014-01-01

To understand the relationship between protein sequence and structure, this work extends the knob-socket model in an investigation of β-sheet packing. Over a comprehensive set of β-sheet folds, the contacts between residues were used to identify packing cliques: sets of residues that all contact each other. These packing cliques were then classified based on size and contact order. From this analysis, the 2 types of 4 residue packing cliques necessary to describe β-sheet packing were characterized. Both occur between 2 adjacent hydrogen bonded β-strands. First, defining the secondary structure packing within β-sheets, the combined socket or XY:HG pocket consists of 4 residues i,i+2 on one strand and j,j+2 on the other. Second, characterizing the tertiary packing between β-sheets, the knob-socket XY:H+B consists of a 3 residue XY:H socket (i,i+2 on one strand and j on the other) packed against a knob B residue (residue k distant in sequence). Depending on the packing depth of the knob B residue, 2 types of knob-sockets are found: side-chain and main-chain sockets. The amino acid composition of the pockets and knob-sockets reveal the sequence specificity of β-sheet packing. For β-sheet formation, the XY:HG pocket clearly shows sequence specificity of amino acids. For tertiary packing, the XY:H+B side-chain and main-chain sockets exhibit distinct amino acid preferences at each position. These relationships define an amino acid code for β-sheet structure and provide an intuitive topological mapping of β-sheet packing. PMID:24668690

A Description of Local Time Asymmetries in the Kronian Current Sheet

NASA Astrophysics Data System (ADS)

Nickerson, J. S.; Hansen, K. C.; Gombosi, T. I.

2012-12-01

Cassini observations imply that Saturn's magnetospheric current sheet is displaced northward above the rotational equator [C.S. Arridge et al., Warping of Saturn's magnetospheric and magnetotail current sheets, Journal of Geophysical Research, Vol. 113, August 2008]. Arridge et al. show that this hinging of the current sheet above the equator occurs over the noon, midnight, and dawn local time sectors. They present an azimuthally independent model to describe this paraboloid-like geometry. We have used our global MHD model, BATS-R-US/SWMF, to study Saturn's magnetospheric current sheet under various solar wind dynamic pressure and solar zenith angle conditions. We show that under reasonable conditions the current sheet does take on the basic shape of the Arridge model in the noon, midnight, and dawn sectors. However, the hinging distance parameter used in the Arridge model is not a constant and does in fact vary in Saturn local time. We recommend that the Arridge model should be adjusted to account for this azimuthal dependence. Arridge et al. does not discuss the shape of the current sheet in the dusk sector due to an absence of data but does presume that the current sheet will assume the same geometry in this region. On the contrary, our model shows that this is not the case. On the dusk side the current sheet hinges (aggressively) southward and cannot be accounted for by the Arridge model. We will present results from our simulations showing the deviation from axisymmetry and the general behavior of the current sheet under different conditions.

Coupled ice sheet-ocean modelling to investigate ocean driven melting of marine ice sheets in Antarctica

NASA Astrophysics Data System (ADS)

Jong, Lenneke; Gladstone, Rupert; Galton-Fenzi, Ben

2017-04-01

Ocean induced melting below the ice shelves of marine ice sheets is a major source of uncertainty for predictions of ice mass loss and Antarctica's resultant contribution to future sea level rise. The floating ice shelves provide a buttressing force against the flow of ice across the grounding line into the ocean. Thinning of these ice shelves due to an increase in melting reduces this force and can lead to an increase in the discharge of grounded ice. Fully coupled modelling of ice sheet-ocean interactions is key to improving understanding the influence of the Southern ocean on the evolution of the Antarctic ice sheet, and to predicting its future behaviour under changing climate conditions. Coupling of ocean and ice sheet models is needed to provide more realistic melt rates at the base of ice shelves and hence make better predictions of the behaviour of the grounding line and the shape of the ice-shelf cavity as the ice sheet evolves. The Framework for Ice Sheet - Ocean Coupling (FISOC) has been developed to provide a flexible platform for performing coupled ice sheet - ocean modelling experiments. We present preliminary results using FISOC to couple the Regional Ocean Modelling System (ROMS) with Elmer/Ice in idealised experiments Marine Ice Sheet-Ocean Model Intercomparison Project (MISOMIP). These experiments use an idealised geometry motivated by that of Pine Island glacier and the adjacent Amundsen Sea in West Antarctica, a region which has shown shown signs of thinning ice and grounding line retreat.

Dynamics of the last glacial maximum Antarctic ice-sheet and its response to ocean forcing

PubMed Central

Golledge, Nicholas R.; Fogwill, Christopher J.; Mackintosh, Andrew N.; Buckley, Kevin M.

2012-01-01

Retreat of the Last Glacial Maximum (LGM) Antarctic ice sheet is thought to have been initiated by changes in ocean heat and eustatic sea level propagated from the Northern Hemisphere (NH) as northern ice sheets melted under rising atmospheric temperatures. The extent to which spatial variability in ice dynamics may have modulated the resultant pattern and timing of decay of the Antarctic ice sheet has so far received little attention, however, despite the growing recognition that dynamic effects account for a sizeable proportion of mass-balance changes observed in modern ice sheets. Here we use a 5-km resolution whole-continent numerical ice-sheet model to assess whether differences in the mechanisms governing ice sheet flow could account for discrepancies between geochronological studies in different parts of the continent. We first simulate the geometry and flow characteristics of an equilibrium LGM ice sheet, using pan-Antarctic terrestrial and marine geological data for constraint, then perturb the system with sea level and ocean heat flux increases to investigate ice-sheet vulnerability. Our results identify that fast-flowing glaciers in the eastern Weddell Sea, the Amundsen Sea, central Ross Sea, and in the Amery Trough respond most rapidly to ocean forcings, in agreement with empirical data. Most significantly, we find that although ocean warming and sea-level rise bring about mainly localized glacier acceleration, concomitant drawdown of ice from neighboring areas leads to widespread thinning of entire glacier catchments—a discovery that has important ramifications for the dynamic changes presently being observed in modern ice sheets. PMID:22988078

Dynamics of the last glacial maximum Antarctic ice-sheet and its response to ocean forcing.

PubMed

Golledge, Nicholas R; Fogwill, Christopher J; Mackintosh, Andrew N; Buckley, Kevin M

2012-10-02

Retreat of the Last Glacial Maximum (LGM) Antarctic ice sheet is thought to have been initiated by changes in ocean heat and eustatic sea level propagated from the Northern Hemisphere (NH) as northern ice sheets melted under rising atmospheric temperatures. The extent to which spatial variability in ice dynamics may have modulated the resultant pattern and timing of decay of the Antarctic ice sheet has so far received little attention, however, despite the growing recognition that dynamic effects account for a sizeable proportion of mass-balance changes observed in modern ice sheets. Here we use a 5-km resolution whole-continent numerical ice-sheet model to assess whether differences in the mechanisms governing ice sheet flow could account for discrepancies between geochronological studies in different parts of the continent. We first simulate the geometry and flow characteristics of an equilibrium LGM ice sheet, using pan-Antarctic terrestrial and marine geological data for constraint, then perturb the system with sea level and ocean heat flux increases to investigate ice-sheet vulnerability. Our results identify that fast-flowing glaciers in the eastern Weddell Sea, the Amundsen Sea, central Ross Sea, and in the Amery Trough respond most rapidly to ocean forcings, in agreement with empirical data. Most significantly, we find that although ocean warming and sea-level rise bring about mainly localized glacier acceleration, concomitant drawdown of ice from neighboring areas leads to widespread thinning of entire glacier catchments-a discovery that has important ramifications for the dynamic changes presently being observed in modern ice sheets.

Nonlinear Dynamics of Non-uniform Current-Vortex Sheets in Magnetohydrodynamic Flows

NASA Astrophysics Data System (ADS)

Matsuoka, C.; Nishihara, K.; Sano, T.

2017-04-01

A theoretical model is proposed to describe fully nonlinear dynamics of interfaces in two-dimensional MHD flows based on an idea of non-uniform current-vortex sheet. Application of vortex sheet model to MHD flows has a crucial difficulty because of non-conservative nature of magnetic tension. However, it is shown that when a magnetic field is initially parallel to an interface, the concept of vortex sheet can be extended to MHD flows (current-vortex sheet). Two-dimensional MHD flows are then described only by a one-dimensional Lagrange parameter on the sheet. It is also shown that bulk magnetic field and velocity can be calculated from their values on the sheet. The model is tested by MHD Richtmyer-Meshkov instability with sinusoidal vortex sheet strength. Two-dimensional ideal MHD simulations show that the nonlinear dynamics of a shocked interface with density stratification agrees fairly well with that for its corresponding potential flow. Numerical solutions of the model reproduce properly the results of the ideal MHD simulations, such as the roll-up of spike, exponential growth of magnetic field, and its saturation and oscillation. Nonlinear evolution of the interface is found to be determined by the Alfvén and Atwood numbers. Some of their dependence on the sheet dynamics and magnetic field amplification are discussed. It is shown by the model that the magnetic field amplification occurs locally associated with the nonlinear dynamics of the current-vortex sheet. We expect that our model can be applicable to a wide variety of MHD shear flows.

The effect of mesenchymal stem cell sheets on structural allograft healing of critical-sized femoral defects in mice

PubMed Central

Long, Teng; Zhu, Zhenan; Awad, Hani A.; Schwarz, Edward M.; Hilton, Matthew J.; Dong, Yufeng

2014-01-01

Structural bone allografts are widely used in the clinic to treat critical sized bone defects, despite lacking the osteoinductive characteristics of live autografts. To address this, we generated revitalized structural allografts wrapped with mesenchymal stem/progenitor cell (MSC) sheets, which were produced by expanding primary syngenic bone marrow derived cells on temperature-responsive plates, as a tissue engineered periosteum. In vitro assays demonstrated maintenance of the MSC phenotype in the sheets, suggesting that short-term culturing of MSC sheets is not detrimental. To test their efficacy in vivo, allografts wrapped with MSC sheets were transplanted into 4-mm murine femoral defects and compared to allografts with direct seeding of MSCs and allografts without cells. Evaluations consisted of x-ray plain radiography, 3D microCT, histology, and biomechanical testing at 4- and 6-weeks post-surgery. Our findings demonstrate that MSC sheets induce prolonged cartilage formation at the graft-host junction and enhanced bone callus formation, as well as graft-host osteointegration. Moreover, a large periosteal callus was observed spanning the allografts with MSC sheets, which partially mimics live autograft healing. Finally, biomechanical testing showed a significant increase in the structural and functional properties of MSC sheet grafted femurs. Taken together, MSC sheets exhibit enhanced osteogenicity during critical sized bone defect repair, demonstrating the feasibility of this tissue engineering solution for massive allograft healing. PMID:24393269

Scanning thin-sheet laser imaging microscopy (sTSLIM) with structured illumination and HiLo background rejection.

PubMed

Schröter, Tobias J; Johnson, Shane B; John, Kerstin; Santi, Peter A

2012-01-01

We report replacement of one side of a static illumination, dual sided, thin-sheet laser imaging microscope (TSLIM) with an intensity modulated laser scanner in order to implement structured illumination (SI) and HiLo image demodulation techniques for background rejection. The new system is equipped with one static and one scanned light-sheet and is called a scanning thin-sheet laser imaging microscope (sTSLIM). It is an optimized version of a light-sheet fluorescent microscope that is designed to image large specimens (<15 mm in diameter). In this paper we describe the hardware and software modifications to TSLIM that allow for static and uniform light-sheet illumination with SI and HiLo image demodulation. The static light-sheet has a thickness of 3.2 µm; whereas, the scanned side has a light-sheet thickness of 4.2 µm. The scanned side images specimens with subcellular resolution (<1 µm lateral and <4 µm axial resolution) with a size up to 15 mm. SI and HiLo produce superior contrast compared to both the uniform static and scanned light-sheets. HiLo contrast was greater than SI and is faster and more robust than SI because as it produces images in two-thirds of the time and exhibits fewer intensity streaking artifacts. 2011 Optical Society of America

First principles study of structural, vibrational and electronic properties of graphene-like MX 2 (M=Mo, Nb, W, Ta; X=S, Se, Te) monolayers

NASA Astrophysics Data System (ADS)

Ding, Yi; Wang, Yanli; Ni, Jun; Shi, Lin; Shi, Siqi; Tang, Weihua

2011-05-01

Using first principles calculations, we investigate the structural, vibrational and electronic structures of the monolayer graphene-like transition-metal dichalcogenide (MX 2) sheets. We find the lattice parameters and stabilities of the MX 2 sheets are mainly determined by the chalcogen atoms, while the electronic properties depend on the metal atoms. The NbS 2 and TaS 2 sheets have comparable energetic stabilities to the synthesized MoS 2 and WS 2 ones. The molybdenum and tungsten dichalcogenide (MoX 2 and WX 2) sheets have similar lattice parameters, vibrational modes, and electronic structures. These analogies also exist between the niobium and tantalum dichalcogenide (NbX 2 and TaX 2) sheets. However, the NbX 2 and TaX 2 sheets are metals, while the MoX 2 and WX 2 ones are semiconductors with direct-band gaps. When the Nb and Ta atoms are doped into the MoS 2 and WS 2 sheets, a semiconductor-to-metal transition occurs. Comparing to the bulk compounds, these monolayer sheets have similar structural parameters and properties, but their vibrational and electronic properties are varied and have special characteristics. Our results suggest that the graphene-like MX 2 sheets have potential applications in nano-electronics and nano-devices.

Centennial-scale Holocene climate variations amplified by Antarctic Ice Sheet discharge

NASA Astrophysics Data System (ADS)

Bakker, Pepijn; Clark, Peter U.; Golledge, Nicholas R.; Schmittner, Andreas; Weber, Michael E.

2017-01-01

Proxy-based indicators of past climate change show that current global climate models systematically underestimate Holocene-epoch climate variability on centennial to multi-millennial timescales, with the mismatch increasing for longer periods. Proposed explanations for the discrepancy include ocean-atmosphere coupling that is too weak in models, insufficient energy cascades from smaller to larger spatial and temporal scales, or that global climate models do not consider slow climate feedbacks related to the carbon cycle or interactions between ice sheets and climate. Such interactions, however, are known to have strongly affected centennial- to orbital-scale climate variability during past glaciations, and are likely to be important in future climate change. Here we show that fluctuations in Antarctic Ice Sheet discharge caused by relatively small changes in subsurface ocean temperature can amplify multi-centennial climate variability regionally and globally, suggesting that a dynamic Antarctic Ice Sheet may have driven climate fluctuations during the Holocene. We analysed high-temporal-resolution records of iceberg-rafted debris derived from the Antarctic Ice Sheet, and performed both high-spatial-resolution ice-sheet modelling of the Antarctic Ice Sheet and multi-millennial global climate model simulations. Ice-sheet responses to decadal-scale ocean forcing appear to be less important, possibly indicating that the future response of the Antarctic Ice Sheet will be governed more by long-term anthropogenic warming combined with multi-centennial natural variability than by annual or decadal climate oscillations.

Endogenous Sheet-Averaged Tension Within a Large Epithelial Cell Colony.

PubMed

Dumbali, Sandeep P; Mei, Lanju; Qian, Shizhi; Maruthamuthu, Venkat

2017-10-01

Epithelial cells form quasi-two-dimensional sheets that function as contractile media to effect tissue shape changes during development and homeostasis. Endogenously generated intrasheet tension is a driver of such changes, but has predominantly been measured in the presence of directional migration. The nature of epithelial cell-generated forces transmitted over supracellular distances, in the absence of directional migration, is thus largely unclear. In this report, we consider large epithelial cell colonies which are archetypical multicell collectives with extensive cell-cell contacts but with a symmetric (circular) boundary. Using the traction force imbalance method (TFIM) (traction force microscopy combined with physical force balance), we first show that one can determine the colony-level endogenous sheet forces exerted at the midline by one half of the colony on the other half with no prior assumptions on the uniformity of the mechanical properties of the cell sheet. Importantly, we find that this colony-level sheet force exhibits large variations with orientation-the difference between the maximum and minimum sheet force is comparable to the average sheet force itself. Furthermore, the sheet force at the colony midline is largely tensile but the shear component exhibits significantly more variation with orientation. We thus show that even an unperturbed epithelial colony with a symmetric boundary shows significant directional variation in the endogenous sheet tension and shear forces that subsist at the colony level.

A Robust Method to Generate Mechanically Anisotropic Vascular Smooth Muscle Cell Sheets for Vascular Tissue Engineering.

PubMed

Backman, Daniel E; LeSavage, Bauer L; Shah, Shivem B; Wong, Joyce Y

2017-06-01

In arterial tissue engineering, mimicking native structure and mechanical properties is essential because compliance mismatch can lead to graft failure and further disease. With bottom-up tissue engineering approaches, designing tissue components with proper microscale mechanical properties is crucial to achieve the necessary macroscale properties in the final implant. This study develops a thermoresponsive cell culture platform for growing aligned vascular smooth muscle cell (VSMC) sheets by photografting N-isopropylacrylamide (NIPAAm) onto micropatterned poly(dimethysiloxane) (PDMS). The grafting process is experimentally and computationally optimized to produce PNIPAAm-PDMS substrates optimal for VSMC attachment. To allow long-term VSMC sheet culture and increase the rate of VSMC sheet formation, PNIPAAm-PDMS surfaces were further modified with 3-aminopropyltriethoxysilane yielding a robust, thermoresponsive cell culture platform for culturing VSMC sheets. VSMC cell sheets cultured on patterned thermoresponsive substrates exhibit cellular and collagen alignment in the direction of the micropattern. Mechanical characterization of patterned, single-layer VSMC sheets reveals increased stiffness in the aligned direction compared to the perpendicular direction whereas nonpatterned cell sheets exhibit no directional dependence. Structural and mechanical anisotropy of aligned, single-layer VSMC sheets makes this platform an attractive microstructural building block for engineering a vascular graft to match the in vivo mechanical properties of native arterial tissue. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Silicon on ceramic process. Silicon sheet growth development for the large-area silicon sheet task of the low-cost silicon solar array project

NASA Technical Reports Server (NTRS)

Zook, J. D.; Heaps, J. D.; Maciolek, R. B.; Koepke, B. G.; Butter, C. D.; Schuldt, S. B.

1977-01-01

The technical and economic feasibility of producing solar-cell-quality sheet silicon was investigated. The sheets were made by coating one surface of carbonized ceramic substrates with a thin layer of large-grain polycrystalline silicon from the melt. Significant progress was made in all areas of the program.

Effects of transverse temperature field nonuniformity on stress in silicon sheet growth

NASA Technical Reports Server (NTRS)

Mataga, P. A.; Hutchinson, J. W.; Chalmers, B.; Bell, R. O.; Kalejs, J. P.

1987-01-01

Stress and strain rate distributions are calculated using finite element analysis for steady-state growth of thin silicon sheet temperature nonuniformities imposed in the transverse (sheet width) dimension. Significant reductions in residual stress are predicted to occur for the case where the sheet edge is cooled relative to its center provided plastic deformation with high creep rates is present.

75 FR 13777 - Disaster Assistance Fact Sheet DAP9580.107, Child Care Services

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-23

...] Disaster Assistance Fact Sheet DAP9580.107, Child Care Services AGENCY: Federal Emergency Management Agency... (FEMA) is providing notice of the availability of the final Disaster Assistance Fact Sheet DAP9580.107...'s Web site at http://www.fema.gov . You may also view a hard copy of the fact sheet at the Office of...

13. Photograph of sheet 1 (index and title sheet) of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. Photograph of sheet 1 (index and title sheet) of the Indiana State Highway Commission repair plans of 1969 for the Cicott Street Bridge. Photograph of a 24' by 36' print made from microfilm in the archives of the Indiana Department of Transportation in Indianapolis. - Cicott Street Bridge, Spanning Wabash River at State Road 25, Logansport, Cass County, IN

9. Photograph of sheet 1 (index and title sheet) of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. Photograph of sheet 1 (index and title sheet) of the State Highway Department of Indiana repair plans of 1957 for the Cicott Street Bridge. Photograph of a 24' by 36' print made from microfilm in the archives of the Indiana Department of Transportation in Indianapolis. - Cicott Street Bridge, Spanning Wabash River at State Road 25, Logansport, Cass County, IN

75 FR 76396 - Stainless Steel Sheet and Strip in Coils From Mexico: Extension of Time Limit for Final Results...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-08

... DEPARTMENT OF COMMERCE International Trade Administration [A-201-822] Stainless Steel Sheet and... administrative review of the antidumping duty order on stainless steel sheet and strip in coils (S4 in coils) from Mexico for the period July 1, 2008, through June 30, 2009. See Stainless Steel Sheet and Strip in...

Partial regeneration of uterine horns in rats through adipose-derived stem cell sheets.

PubMed

Sun, Huijun; Lu, Jie; Li, Bo; Chen, Shuqiang; Xiao, Xifeng; Wang, Jun; Wang, Jingjing; Wang, Xiaohong

2018-06-20

Severe uterine damage and infection lead to intrauterine adhesions, which result in hypomenorrhea, amenorrhea and infertility. Cell sheet engineering has shown great promise in clinical applications. Adipose-derived stem cells (ADSCs) are emerging as an alternative source of stem cells for cell-based therapies. In the present study, we investigated the feasibility of applying ADSCs as seed cells to form scaffold-free cell sheet. Data showed that ADSC sheets expressed higher levels of FGF, Col I, TGFβ and VEGF than ADSCs in suspension, while increased expression of this gene set was associated with stemness, including Nanog, Oct4 and Sox2. We then investigated the therapeutic effects of 3D ADSCs sheet on regeneration in a rat model. We found that ADSCs were mainly detected in the basal layer of the regenerating endometrium in the cell sheet group at 21 days after transplantation. Additionally, some ADSCs differentiated into stromal-like cells. Moreover, ADSC sheets transplanted into partially excised uteri promoted regeneration of the endometrium cells, muscle cells and stimulated angiogenesis, and also resulted in better pregnancy outcomes. Therefore, ADSC sheet therapy shows considerable promise as a new treatment for severe uterine damage.

Topical Silicone Sheet Application in the Treatment of Hypertrophic Scars and Keloids.

PubMed

Westra, Iris; Pham, Hth; Niessen, Frank B

2016-10-01

Objective: Since the early 1980s, topical silicone sheets have been used in the treatment of hypertrophic scars and keloids.This study aimed to determine the optimal duration and application of these sheets. Design: multi-centered therapeutic study. Setting and participants: A total of 224 patients were included in this study; 205 patients with hypertrophic scars and 19 patients with keloids. Patients received treatment with a topical silicone sheet. Treated scars varied in age, ranging from two weeks to 62 years and treatment time ranged from one month to 16 months. Assessment of the scars was performed by the use of standardized study forms and digital photography. Measurements: Skin therapists objectively assessed the scars on its color, thickness, and elasticity. Patients themselves subjectively assessed their perception of their scar and their experience with the usage of the topical silicone sheet. Results: After applying the topical silicone sheet, all scars, regardless of type of scar and maturity, improved significantly in color, thickness, and elasticity. Conclusion: In this study, treatment with the topical silicone sheet showed significant improvement on both hypertrophic scars and keloids. Best results were reached when the silicone sheet was applied at least four hours per day.

Relative sea-level rise around East Antarctica during Oligocene glaciation

NASA Astrophysics Data System (ADS)

Stocchi, Paolo; Escutia, Carlota; Houben, Alexander J. P.; Vermeersen, Bert L. A.; Bijl, Peter K.; Brinkhuis, Henk; Deconto, Robert M.; Galeotti, Simone; Passchier, Sandra; Pollard, David; Brinkhuis, Henk; Escutia, Carlota; Klaus, Adam; Fehr, Annick; Williams, Trevor; Bendle, James A. P.; Bijl, Peter K.; Bohaty, Steven M.; Carr, Stephanie A.; Dunbar, Robert B.; Flores, Jose Abel; Gonzàlez, Jhon J.; Hayden, Travis G.; Iwai, Masao; Jimenez-Espejo, Francisco J.; Katsuki, Kota; Kong, Gee Soo; McKay, Robert M.; Nakai, Mutsumi; Olney, Matthew P.; Passchier, Sandra; Pekar, Stephen F.; Pross, Jörg; Riesselman, Christina; Röhl, Ursula; Sakai, Toyosaburo; Shrivastava, Prakash Kumar; Stickley, Catherine E.; Sugisaki, Saiko; Tauxe, Lisa; Tuo, Shouting; van de Flierdt, Tina; Welsh, Kevin; Yamane, Masako

2013-05-01

During the middle and late Eocene (~ 48-34Myr ago), the Earth's climate cooled and an ice sheet built up on Antarctica. The stepwise expansion of ice on Antarctica induced crustal deformation and gravitational perturbations around the continent. Close to the ice sheet, sea level rose despite an overall reduction in the mass of the ocean caused by the transfer of water to the ice sheet. Here we identify the crustal response to ice-sheet growth by forcing a glacial-hydro isostatic adjustment model with an Antarctic ice-sheet model. We find that the shelf areas around East Antarctica first shoaled as upper mantle material upwelled and a peripheral forebulge developed. The inner shelf subsequently subsided as lithosphere flexure extended outwards from the ice-sheet margins. Consequently the coasts experienced a progressive relative sea-level rise. Our analysis of sediment cores from the vicinity of the Antarctic ice sheet are in agreement with the spatial patterns of relative sea-level change indicated by our simulations. Our results are consistent with the suggestion that near-field processes such as local sea-level change influence the equilibrium state obtained by an ice-sheet grounding line.

Hypervelocity impact shield

NASA Technical Reports Server (NTRS)

Cour-Palais, Burton G. (Inventor); Crews, Jeanne Lee (Inventor)

1991-01-01

A hypervelocity impact shield and method for protecting a wall structure, such as a spacecraft wall, from impact with particles of debris having densities of about 2.7 g/cu cm and impact velocities up to 16 km/s are disclosed. The shield comprises a stack of ultra thin sheets of impactor disrupting material supported and arranged by support means in spaced relationship to one another and mounted to cover the wall in a position for intercepting the particles. The sheets are of a number and spacing such that the impacting particle and the resulting particulates of the impacting particle and sheet material are successively impact-shocked to a thermal state of total melt and/or vaporization to a degree as precludes perforation of the wall. The ratio of individual sheet thickness to the theoretical diameter of particles of debris which may be of spherical form is in the range of 0.03 to 0.05. The spacing between adjacent sheets is such that the debris cloud plume of liquid and vapor resulting from an impacting particle penetrating a sheet does not puncture the next adjacent sheet prior to the arrival thereat of fragment particulates of sheet material and the debris particle produced by a previous impact.

Controllable curvature from planar polymer sheets in response to light.

PubMed

Hubbard, Amber M; Mailen, Russell W; Zikry, Mohammed A; Dickey, Michael D; Genzer, Jan

2017-03-22

The ability to change shape and control curvature in 3D structures starting from planar sheets can aid in assembly and add functionality to an object. Herein, we convert planar sheets of shape memory polymers (SMPs) into 3D objects with controllable curvature by dictating where the sheets shrink. Ink patterned on the surface of the sheet absorbs infrared (IR) light, resulting in localized heating, and the material shrinks locally wherever the temperature exceeds the activation temperature, T a . We introduce two different mechanisms for controlling curvature within SMP sheets. The 'direct' mechanism uses localized shrinkage to induce curvature only in regions patterned with ink. The 'indirect' mechanism uses localized shrinkage in regions patterned with ink to induce curvature in neighboring regions without ink through a balance of internal stresses. Finite element analysis predicts the final shape of the polymer sheets with excellent qualitative agreement with experimental studies. Results from this study show that curvature can be controlled by the distribution and darkness of the ink pattern on the polymer sheet. Additionally, we utilize the direct and indirect curvature mechanisms to demonstrate the formation and actuation of gripper devices, which represent the potential utility of this approach.

Synthesis and Characterization of High Energy Sheet Materials Based on HMX / RDX and Hydroxyl Terminated Polybutadiene

NASA Astrophysics Data System (ADS)

Elsharkawy, Karim; Guo, Lin; Taha, Elhussein; Fouda, Hany

2017-07-01

In this paper three types of thin sheets of highly energetic materials were prepared and characterized. The first based on 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX). The second type based on 1,3,5-trinitro-1,3,5-triazinane (RDX). Both types contain polyurethane (PU), formulated by hydroxyl terminated polybutadiene (HTPB) and Isophorondiisocyanate (IPDI). The third type based on (RDX) and polyisoprene (PI) as high elastomeric material. The first and second types of thin sheets were prepared by applying the casting technique while the third type was prepared by slurry technique then followed by rolling of the prepared beads of the RDX coated by PI. These high energy sheet materials were cured in oven at 60°C. The measured explosive properties of the prepared sheets were discussed and showed that the sensitivity to impact and friction of the prepared sheets explosives materials were markedly decreased when compared to pure HMX or pure RDX, but the sensitivity to heat was close to that of pure RDX. In spite of the markedly decrease in the sensitivity of these sheets, the explosive characteristics were nearly not affected the sheets have very good stress-strain values.

Initial rigid response and softening transition of highly stretchable kirigami sheet materials.

PubMed

Isobe, Midori; Okumura, Ko

2016-04-27

We study, experimentally and theoretically, the mechanical response of sheet materials on which line cracks or cuts are arranged in a simple pattern. Such sheet materials, often called kirigami (the Japanese words, kiri and gami, stand for cut and paper, respectively), demonstrate a unique mechanical response promising for various engineering applications such as stretchable batteries: kirigami sheets possess a mechanical regime in which sheets are highly stretchable and very soft compared with the original sheets without line cracks, by virtue of out-of-plane deformation. However, this regime starts after a transition from an initial stiff regime governed by in-plane deformation. In other words, the softness of the kirigami structure emerges as a result of a transition from the two-dimensional to three-dimensional deformation, i.e., from stretching to bending. We clarify the physical origins of the transition and mechanical regimes, which are revealed to be governed by simple scaling laws. The results could be useful for controlling and designing the mechanical response of sheet materials including cell sheets for medical regeneration and relevant to the development of materials with tunable stiffness and mechanical force sensors.

Theoretical modeling of the plasma-assisted catalytic growth and field emission properties of graphene sheet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Suresh C.; Gupta, Neha

2015-12-15

A theoretical modeling for the catalyst-assisted growth of graphene sheet in the presence of plasma has been investigated. It is observed that the plasma parameters can strongly affect the growth and field emission properties of graphene sheet. The model developed accounts for the charging rate of the graphene sheet; number density of electrons, ions, and neutral atoms; various elementary processes on the surface of the catalyst nanoparticle; surface diffusion and accretion of ions; and formation of carbon-clusters and large graphene islands. In our investigation, it is found that the thickness of the graphene sheet decreases with the plasma parameters, numbermore » density of hydrogen ions and RF power, and consequently, the field emission of electrons from the graphene sheet surface increases. The time evolution of the height of graphene sheet with ion density and sticking coefficient of carbon species has also been examined. Some of our theoretical results are in compliance with the experimental observations.« less

Prevention of crack in stretch flanging process using hot stamping technique

NASA Astrophysics Data System (ADS)

Syafiq, Y. Mohd; Hamedon, Z.; Azila Aziz, Wan; Razlan Yusoff, Ahmad

2017-10-01

Demand for enhancing of passenger safety as well as weight reduction of automobiles has increased the use of high strength steel sheets. As a sheet metal is a lightweight having high strength is suitable for producing automotive parts such as white body panel. The stretch flanging of the high strength steel sheet is a problem due to high springback and easy to crack. This study uses three methods to stretch flange the sheets; using lubricants, shear-edge polishing and hot stamping. The effectiveness of these methods will be measured by comparing the flange length of each methods can achieved. For stretch flange with lubricant and polished sheared edge, the flange length failed to achieve the target 15 mm while hot stamping improved the formability of the sheet and preventing the occurrence of the springback and crack. Hot stamping not only improved formability of the sheet but also transformed the microstructure into martensite thus improve the hardness and the strength of the sheet after been quenched with the dies.

Shape of the terrestrial plasma sheet in the near-Earth magnetospheric tail as imaged by the Interstellar Boundary Explorer

DOE PAGES

Dayeh, M. A.; Fuselier, S. A.; Funsten, H. O.; ...

2015-04-11

We present remote, continuous observations from the Interstellar Boundary Explorer of the terrestrial plasma sheet location back to -16 Earth radii (R E) in the magnetospheric tail using energetic neutral atom emissions. The time period studied includes two orbits near the winter and summer solstices, thus associated with large negative and positive dipole tilt, respectively. Continuous side-view images reveal a complex shape that is dominated mainly by large-scale warping due to the diurnal motion of the dipole axis. Superposed on the global warped geometry are short-time fluctuations in plasma sheet location that appear to be consistent with plasma sheet flappingmore » and possibly twisting due to changes in the interplanetary conditions. We conclude that the plasma sheet warping due to the diurnal motion dominates the average shape of the plasma sheet. Over short times, the position of the plasma sheet can be dominated by twisting and flapping.« less

Altitude, depth, and thickness of the Galena-Platteville Bedrock Unit in the subcrop area of Illinois and Wisconsin

USGS Publications Warehouse

Brown, Timothy A.; Dunning, Charles P.; Sharpe, Jennifer B.

2000-01-01

The report series will enable investigators involved in site-specific studies within the subcrop area to understand the regional geologic framework of the unit and to find additional reference sources. This report consists of four sheets that show the altitude (sheet 1), depth from land surface (sheet 2), total thickness (sheet 3), and location of altitude data (sheet 4) of the lithologic units that constitute the Galena-Platteville bedrock unit within the subcrop area. The sheets also show major known geologic features within the Galena-Platteville study area in Illinois and Wisconsin. A geographic information system (GIS) was used to generate data layers (coverages) from point data and from published and unpublished contour maps at various scales and detail. Standard GIS procedures were used to change the coverages into the maps shown on the sheets presented in this report. A list of references for the data used to prepare the maps is provided. 

Biological studies and electrical conductivity of paper sheet based on PANI/PS/Ag-NPs nanocomposite.

PubMed

Youssef, A M; Mohamed, S A; Abdel-Aziz, M S; Abdel-Aziz, M E; Turky, G; Kamel, S

2016-08-20

Polyaniline (PANI) with/without polystyrene (PS), was successfully manufactured in the occurrence of dispersed pulp fibers via the oxidative polymerization reaction of aniline monomer to produce conductive paper sheets containing PANI, PANI/PS composites. Additionally, sliver nitrate (Ag-NO3) was added by varied loadings to the oxidative polymerization of aniline monomer to provide sliver nanoparticles (Ag-NPs) emptied into the prepared paper sheets. The prepared paper sheets were examined using scanning electron microscopy (SEM), X-ray diffraction (XRD) and infrared spectroscopy (IR), the mechanical properties of the prepared paper sheets were evaluated. Moreover, the electrical conductivity and biological studies such as cellulases assay, Microorganism & culture condition and detection of the released of Ag-NPs were evaluated. Furthermore, the prepared paper sheets were displayed good antibacterial properties contrary to gram positive and gram negative bacteria. Consequently, the prepared paper sheet may be used as novel materials for packaging applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Vitamin C treatment promotes mesenchymal stem cell sheet formation and tissue regeneration by elevating telomerase activity.

PubMed

Wei, Fulan; Qu, Cunye; Song, Tieli; Ding, Gang; Fan, Zhipeng; Liu, Dayong; Liu, Yi; Zhang, Chunmei; Shi, Songtao; Wang, Songlin

2012-09-01

Cell sheet engineering has been developed as an alternative approach to improve mesenchymal stem cell-mediated tissue regeneration. In this study, we found that vitamin C (Vc) was capable of inducing telomerase activity in periodontal ligament stem cells (PDLSCs), leading to the up-regulated expression of extracellular matrix type I collagen, fibronectin, and integrin β1, stem cell markers Oct4, Sox2, and Nanog as well as osteogenic markers RUNX2, ALP, OCN. Under Vc treatment, PDLSCs can form cell sheet structures because of increased cell matrix production. Interestingly, PDLSC sheets demonstrated a significant improvement in tissue regeneration compared with untreated control dissociated PDLSCs and offered an effective treatment for periodontal defects in a swine model. In addition, bone marrow mesenchymal stem cell sheets and umbilical cord mesenchymal stem cell sheets were also well constructed using this method. The development of Vc-mediated mesenchymal stem cell sheets may provide an easy and practical approach for cell-based tissue regeneration. Copyright © 2011 Wiley Periodicals, Inc.

Beating the Heat - Fast Scanning Melts Silk Beta Sheet Crystals

NASA Astrophysics Data System (ADS)

Cebe, Peggy; Hu, Xiao; Kaplan, David L.; Zhuravlev, Evgeny; Wurm, Andreas; Arbeiter, Daniela; Schick, Christoph

2013-01-01

Beta-pleated-sheet crystals are among the most stable of protein secondary structures, and are responsible for the remarkable physical properties of many fibrous proteins, such as silk, or proteins forming plaques as in Alzheimer's disease. Previous thinking, and the accepted paradigm, was that beta-pleated-sheet crystals in the dry solid state were so stable they would not melt upon input of heat energy alone. Here we overturn that assumption and demonstrate that beta-pleated-sheet crystals melt directly from the solid state to become random coils, helices, and turns. We use fast scanning chip calorimetry at 2,000 K/s and report the first reversible thermal melting of protein beta-pleated-sheet crystals, exemplified by silk fibroin. The similarity between thermal melting behavior of lamellar crystals of synthetic polymers and beta-pleated-sheet crystals is confirmed. Significance for controlling beta-pleated-sheet content during thermal processing of biomaterials, as well as towards disease therapies, is envisioned based on these new findings.

Efficient natural-convective heat transfer properties of carbon nanotube sheets and their roles on the thermal dissipation.

PubMed

Jiang, Shaohui; Liu, Changhong; Fan, Shoushan

2014-03-12

In this work, we report our studies related to the natural-convective heat transfer properties of carbon nanotube (CNT) sheets. We theoretically derived the formulas and experimentally measured the natural-convective heat transfer coefficients (H) via electrical heating method. The H values of the CNT sheets containing different layers (1, 2, 3, and 1000) were measured. We found that the single-layer CNT sheet had a unique ability on heat dissipation because of its great H. The H value of the single-layer CNT sheet was 69 W/(m(2) K) which was about twice of aluminum foil in the same environment. As the layers increased, the H values dropped quickly to the same with that of aluminum foil. We also discussed its roles on thermal dissipation, and the results indicated that the convection was a significant way of dissipation when the CNT sheets were applied on macroscales. These results may give us a new guideline to design devices based on the CNT sheets.

Why S, Not X, Marks the Spot for CME/Flare Eruptions

NASA Technical Reports Server (NTRS)

Moore, Ronald L.; Sterling, Alphonse; Gary, Allen; Cirtain, Jonathan; Falconer, David

2010-01-01

For any major CME/flare eruption: I. The field that erupts is an arcade in which the interior is greatly sheared and twisted. Most of the free magnetic energy to be released: a) Is in the shear and twist of the interior field. b) Is Not due to a big current sheet. The eruption is unleashed by reconnection at a growing current sheet. The current sheet is still little when the reconnection turns on. The unleashed eruption then makes the current sheet much bigger by building it up faster than the reconnection can tear it down. II. Most X-ray jets work the opposite way: a) Tapped free energy is in the field of a pre-jet current sheet. b) Current sheet built by small arcade emerging into ambient field. c) Current sheet still much smaller than the arcade when reconnection turns on and tears it down, producing a jet. III. These rules reflect the low-beta condition in the eruptive magnetic field

Anatomy of an amyloidogenic intermediate: conversion of beta-sheet to alpha-sheet structure in transthyretin at acidic pH.

PubMed

Armen, Roger S; Alonso, Darwin O V; Daggett, Valerie

2004-10-01

The homotetramer of transthyretin (TTR) dissociates into a monomeric amyloidogenic intermediate that self-assembles into amyloid fibrils at low pH. We have performed molecular dynamics simulations of monomeric TTR at neutral and low pH at physiological (310 K) and very elevated temperature (498 K). In the low-pH simulations at both temperatures, one of the two beta-sheets (strands CBEF) becomes disrupted, and alpha-sheet structure forms in the other sheet (strands DAGH). alpha-sheet is formed by alternating alphaL and alphaR residues, and it was first proposed by Pauling and Corey. Overall, the simulations are in agreement with the available experimental observations, including solid-state NMR results for a TTR-peptide amyloid. In addition, they provide a unique explanation for the results of hydrogen exchange experiments of the amyloidogenic intermediate-results that are difficult to explain with beta-structure. We propose that alpha-sheet may represent a key pathological conformation during amyloidogenesis. Copyright 2004 Elsevier Ltd.

Zinc oxide nanorod clusters deposited seaweed cellulose sheet for antimicrobial activity.

PubMed

Bhutiya, Priyank L; Mahajan, Mayur S; Abdul Rasheed, M; Pandey, Manoj; Zaheer Hasan, S; Misra, Nirendra

2018-06-01

Seaweed cellulose was isolated from green seaweed Ulva fasciata using a common bleaching agent. Sheet containing porous mesh was prepared from the extracted seaweed crystalline cellulose along with zinc oxide (ZnO) nanorod clusters grown over the sheet by single step hydrothermal method. Seaweed cellulose and zinc oxide nanorod clusters deposited seaweed cellulose sheet was characterized by FT-IR, XRD, TGA, and SEM-EDX. Morphology showed that the diameter of zinc oxide nanorods were around 70nm. Zinc oxide nanorod clusters deposited on seaweed cellulose sheet gave remarkable antibacterial activity towards gram-positive (Staphylococcus aureus, Bacillus ceresus, Streptococcus thermophilis) and gram-negative (Escherichia coli, Pseudomonas aeruginous) microbes. Such deposited sheet has potential applications in pharmaceutical, biomedical, food packaging, water treatment and biotechnological industries. Copyright © 2018 Elsevier B.V. All rights reserved.

Method of fabricating an article with cavities. [with thin bottom walls

NASA Technical Reports Server (NTRS)

Dale, W. J.; Jurscaga, G. M. (Inventor)

1974-01-01

An article having a cavity with a thin bottom wall is provided by assembling a thin sheet, for example, a metal sheet, adjacent to the surface of a member having one or more apertures. A bonding adhesive is interposed between the thin sheet and the subadjacent member, and the thin sheet is subjected to a high fluid pressure. In order to prevent the differential pressure from being exerted against the thin sheet, the aperture is filled with a plug of solid material having a linear coefficient of thermal expansion higher than that of the member. When the assembly is subjected to pressure, the material is heated to a temperature such that its expansion exerts a pressure against the thin sheet thus reducing the differential pressure.

Utilization of a Biodegradable Mulch Sheet Produced from Poly(Lactic Acid)/Ecoflex®/Modified Starch in Mandarin Orange Groves

PubMed Central

Tachibana, Yuya; Maeda, Takuya; Ito, Osamu; Maeda, Yasukatsu; Kunioka, Masao

2009-01-01

We have developed a mulch sheet made by inflation molding of PLA, Ecoflex® and modified starch, which all have different biodegradabilities. A field test of use as an agricultural mulch sheet for mandarin oranges was carried out over two years. The mechanical properties of the mulch sheet were weakened with time during the field test, but the quality of the mandarin oranges increased, a result of the controlled degradation of the sheet. The most degradable modified starch degraded first, allowing control of the moisture on the soil. Accelerator mass spectroscopy was used for evaluation of the biomass carbon ratio. The biomass carbon ratio decreased by degradation of the biobased materials, PLA and modified starch in the mulch sheet. PMID:19812715

ISMIP6: Ice Sheet Model Intercomparison Project for CMIP6

NASA Technical Reports Server (NTRS)

Nowicki, S.

2015-01-01

ISMIP6 (Ice Sheet Model Intercomparison Project for CMIP6) targets the Cryosphere in a Changing Climate and the Future Sea Level Grand Challenges of the WCRP (World Climate Research Program). Primary goal is to provide future sea level contribution from the Greenland and Antarctic ice sheets, along with associated uncertainty. Secondary goal is to investigate feedback due to dynamic ice sheet models. Experiment design uses and augment the existing CMIP6 (Coupled Model Intercomparison Project Phase 6) DECK (Diagnosis, Evaluation, and Characterization of Klima) experiments. Additonal MIP (Model Intercomparison Project)- specific experiments will be designed for ISM (Ice Sheet Model). Effort builds on the Ice2sea, SeaRISE (Sea-level Response to Ice Sheet Evolution) and COMBINE (Comprehensive Modelling of the Earth System for Better Climate Prediction and Projection) efforts.

Effect of Electron Beam Irradiation on the Tensile Properties of Carbon Nanotubes Sheets and Yarns

NASA Technical Reports Server (NTRS)

Williams, Tiffany S.; Miller, Sandi G.; Baker, James S.; McCorkle, Linda S.; Meador, Michael A.

2013-01-01

Carbon nanotube sheets and yarns were irradiated using electron beam (e-beam) energy to determine the effect of irradiation dose on the tensile properties. Results showed that a slight change in tensile strength occurred after irradiating as-received CNT sheets for 20 minutes, and a slight decrease in tensile strength as the irradiation time approached 90 minutes. On the other hand, the addition of small molecules to the CNT sheet surface had a greater effect on the tensile properties of e-beam irradiated CNT sheets. Some functionalized CNT sheets displayed up to a 57% increase in tensile strength following 90 minutes of e-beam exposure. In addition, as-received CNT yarns showed a significant increase in tensile strength as the irradiation time increased.

The use of smoke acid as an alternative coagulating agent for natural rubber sheets' production.

PubMed

Ferreira, Vanda S; Rêgo, Ione N C; Pastore, Floriano; Mandai, Mariana M; Mendes, Leonardo S; Santos, Karin A M; Rubim, Joel C; Suarez, Paulo A Z

2005-03-01

A comparative study of rubber sheets obtained using formic, acetic, and smoke acid as coagulants is shown for latex obtained from native Amazonian trees and also from commercial cultivated trees. The evaluation of both processes of coagulation was carried out by spectroscopic and physical-chemical analysis, showing no differences in the rubber sheets obtained. This new method of rubber sheet preparation was introduced into Amazonian rainforest rubber tapper communities, which are actually producing in large scale. The physical-mechanical properties were similar among a large sheets made by different rubber tapper communities using this new method.

On the instability of a liquid sheet moving in vacuum

NASA Astrophysics Data System (ADS)

Sisoev, G. M.; Osiptsov, A. N.; Koroteev, A. A.

2018-03-01

A linear stability analysis of a non-isothermal liquid sheet moving in vacuum is studied taking into account the temperature dependencies of the liquid viscosity, thermal conductivity, and surface tension coefficients. It is found that there are two mechanisms of instability. The short-wave instability is caused by viscosity stratification across the sheet due to nonuniform temperature profiles developed downstream in the cooling sheet. The long-wave thermocapillary instability is caused by the temperature gradient along the sheet surfaces. Computed examples of steady flows and their instabilities demonstrated that the unstable short waves have much larger amplification factors.

Synthesis of nanometre-thick MoO3 sheets

NASA Astrophysics Data System (ADS)

Kalantar-Zadeh, Kourosh; Tang, Jianshi; Wang, Minsheng; Wang, Kang L.; Shailos, Alexandros; Galatsis, Kosmas; Kojima, Robert; Strong, Veronica; Lech, Andrew; Wlodarski, Wojtek; Kaner, Richard B.

2010-03-01

The formation of MoO3 sheets of nanoscale thickness is described. They are made from several fundamental sheets of orthorhombic α-MoO3, which can be processed in large quantities via a low cost synthesis route that combines thermal evaporation and mechanical exfoliation. These fundamental sheets consist of double-layers of linked distorted MoO6 octahedra. Atomic force microscopy (AFM) measurements show that the minimum resolvable thickness of these sheets is 1.4 nm which is equivalent to the thickness of two double-layers within one unit cell of the α-MoO3 crystal.

Particle and field characteristics of the high-latitude plasma sheet boundary layer

NASA Technical Reports Server (NTRS)

Parks, G. K.; Mccarthy, M.; Fitzenreiter, R. J.; Ogilvie, K. W.; Etcheto, J.; Anderson, K. A.; Lin, R. P.; Anderson, R. R.; Eastman, T. E.; Frank, L. A.

1984-01-01

Particle and field data obtained by eight ISEE spacecraft experiments are used to define more precisely the characteristics of the high-latitude boundary region of the plasma sheet. A region immediately adjacent to the high-latitude plasma sheet boundary has particle and field characteristics distinctly different from those observed in the lobe and deeper in the central plasma sheet. Electrons over a broad energy interval are 'field-aligned' and bidirectional, whereas in the plasma sheet the distributions are more isotropic. The region supports intense ion flows, large-amplitude electric fields, and enhanced broad-band electrostatic noise.

Quality Control: (Material) Safety Data Sheets.

PubMed

Allen, Loyd V

2017-01-01

Safety Data Sheets (formerly Material Safety Data Sheets) are a system for cataloging information on chemicals, chemical compounds, and chemical mixtures and include instructions for the safe use and potential hazards associated with a particular material or product. At present, there are 16 sections of Safety Data Sheets, and these sections are discussed in this article. Two United States Pharmacopeia compounding-related chapters (<795> and <800>) refer to Safety Data Sheets, and this article provides a brief discussion on the terminology contained within those chapters. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

Rainfall and Sheet Power Equation for Interrill Erosion on Steep Hillslope

NASA Astrophysics Data System (ADS)

Shin, S.; Park, S.; Pierson, F. B.; Al-Hamdan, O. Z.; Williams, C. J.

2012-12-01

Splash and sheet erosion processes dominate on most undisturbed hillslopes of rangeland. Interrill soil erosion should consider the influence of both raindrop and sheet flow to work of soil particles detached by raindrop impact and transported by rainfall-disturbed sheet flow. Interrill erosion equations that combine the influence of both rainfall and runoff have been proposed by several researchers. However most approaches to modeling interrill erosion have been based on statistical relationships given the inherent complexity in derivation of broadly-applicable physically-based erosion parameters. In this study, a rainfall and sheet power equation to evaluate interrill sediment yields (Qs) was derived from the sum of rainfall power and sheet power expressed by rainfall intensity: Qs=a(cosθ/L){α sinθ ∑ I(t)^(11/9)+β tanθ^(1/2) ∑ (1-fr(t))^(5/3) I(t)^(5/3)}^b, where I(t) is rainfall intensity, θ is slope angle, fr(t) is infiltration rate, a, b, α, and β are coefficients, sinθ I(t)^(11/9) is the rainfall power term, and tanθ^(1/2) (1-fr(t))^(5/3) I(t)^(5/3) is the sheet power term. The rainfall power ratio and sheet power ratio decreased and increased with increased rainfall intensity, respectively. The sheet power term depended greatly on infiltration rate controlled by rainfall intensity, vegetation cover, and soil condition. The rainfall and sheet power equation assuming that α and β is 0 was evaluated using field data from plots on steep hillslopes and showed the better correlation with sediment yields than rainfall kinetic energy, runoff discharge, or interrill equations based on rainfall intensity and runoff discharge founded in the literature. This equation successfully explained physical processes for soil erosion that rainfall power is dominant under low rainfall and sheet power is dominant under heavy rainfall. Additional experimental data is needed to assess coefficients of the power equation to determine the relative quantities of rainfall power and sheet power and to evaluate the erosion efficiency of interactions between raindrop impact and sheet flow and soil erodibility. Acknowledgements: This work was supported by a grant (Code#'08 RTIP B-01) from Regional Technology Innovation Program funded by Ministry of Land, Transport and Maritime Affairs of Korean government.;

Culture-expanded mesenchymal stem cell sheets enhance extraction-site alveolar bone growth: An animal study.

PubMed

Mu, S; Tee, B C; Emam, H; Zhou, Y; Sun, Z

2018-04-06

Impaired bone formation of the buccal alveolar plate after tooth extraction during adolescence increases the difficulty of future implant restoration. This study was undertaken to assess the feasibility and efficacy of transplanting autogenous scaffold-free culture-expanded mesenchymal stem cell (MSC) sheets to the buccal alveolar bone surface to stimulate local bone growth. Mandibular bone marrow was aspirated from 3-month-old pigs (n = 5), from which MSCs were isolated and culture expanded. Triple-layer MSC sheets were then fabricated using temperature-responsive tissue culture plates. One month after bone marrow aspirations, the same pigs underwent bilateral extraction of mandibular primary molars, immediately followed by transplantation of 3 autogenous triple-layer MSC sheets on to the subperiosteal buccal alveolar surface of 1 randomly chosen side. The contralateral side (control) underwent the same periosteal reflection surgery without receiving MSC sheet transplantation. Six weeks later, the animals were killed and specimens from both sides were immediately harvested for radiographic and histological analysis. Buccal alveolar bone thickness, tissue mineral density (TMD), mineral apposition and bone volume fraction (BV/TV) were quantified and compared between the MSC sheet and control sides using paired t-tests. Triple-layer MSC sheets were reliably fabricated and the majority of cells remained vital before transplantation. The thickness of buccal bone tended to increase with MSC sheet transplantation (P = .18), with 4 of 5 animals showing an average of 1.82 ± 0.73 mm thicker bone on the MSC sheet side than the control side. After being normalized by the TMD of intracortical bone, the TMD of surface cortical bone was 0.5-fold higher on the MSC sheet side than the control side (P < .05). Likewise, the BV/TV measurements of the buccal surface region were also 0.4-fold higher on the MSC sheet side than the control side (P < .05) after being normalized by measurements from the intracortical region. Mineral apposition measurements were not different between the 2 sides. Mandibular marrow-derived MSCs can be fabricated into cell sheets and autogenous transplantation of MSC sheets onto the subperiosteal buccal alveolar bone surface at the tooth-extraction site may increase local bone density. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Sensitivities of Greenland ice sheet volume inferred from an ice sheet adjoint model

NASA Astrophysics Data System (ADS)

Heimbach, P.; Bugnion, V.

2009-04-01

We present a new and original approach to understanding the sensitivity of the Greenland ice sheet to key model parameters and environmental conditions. At the heart of this approach is the use of an adjoint ice sheet model. Since its introduction by MacAyeal (1992), the adjoint method has become widespread to fit ice stream models to the increasing number and diversity of satellite observations, and to estimate uncertain model parameters such as basal conditions. However, no attempt has been made to extend this method to comprehensive ice sheet models. As a first step toward the use of adjoints of comprehensive three-dimensional ice sheet models we have generated an adjoint of the ice sheet model SICOPOLIS of Greve (1997). The adjoint was generated by means of the automatic differentiation (AD) tool TAF. The AD tool generates exact source code representing the tangent linear and adjoint model of the nonlinear parent model provided. Model sensitivities are given by the partial derivatives of a scalar-valued model diagnostic with respect to the controls, and can be efficiently calculated via the adjoint. By way of example, we determine the sensitivity of the total Greenland ice volume to various control variables, such as spatial fields of basal flow parameters, surface and basal forcings, and initial conditions. Reliability of the adjoint was tested through finite-difference perturbation calculations for various control variables and perturbation regions. Besides confirming qualitative aspects of ice sheet sensitivities, such as expected regional variations, we detect regions where model sensitivities are seemingly unexpected or counter-intuitive, albeit ``real'' in the sense of actual model behavior. An example is inferred regions where sensitivities of ice sheet volume to basal sliding coefficient are positive, i.e. where a local increase in basal sliding parameter increases the ice sheet volume. Similarly, positive ice temperature sensitivities in certain parts of the ice sheet are found (in most regions it is negativ, i.e. an increase in temperature decreases ice sheet volume), the detection of which seems highly unlikely if only conventional perturbation experiments had been used. An effort to generate an efficient adjoint with the newly developed open-source AD tool OpenAD is also under way. Available adjoint code generation tools now open up a variety of novel model applications, notably with regard to sensitivity and uncertainty analyses and ice sheet state estimation or data assimilation.

Modelling the Climate - Greenland Ice Sheet Interaction in the Coupled Ice-sheet/Climate Model EC-EARTH - PISM

NASA Astrophysics Data System (ADS)

Yang, S.; Madsen, M. S.; Rodehacke, C. B.; Svendsen, S. H.; Adalgeirsdottir, G.

2014-12-01

Recent observations show that the Greenland ice sheet (GrIS) has been losing mass with an increasing speed during the past decades. Predicting the GrIS changes and their climate consequences relies on the understanding of the interaction of the GrIS with the climate system on both global and local scales, and requires climate model systems with an explicit and physically consistent ice sheet module. A fully coupled global climate model with a dynamical ice sheet model for the GrIS has recently been developed. The model system, EC-EARTH - PISM, consists of the EC-EARTH, an atmosphere, ocean and sea ice model system, and the Parallel Ice Sheet Model (PISM). The coupling of PISM includes a modified surface physical parameterization in EC-EARTH adapted to the land ice surface over glaciated regions in Greenland. The PISM ice sheet model is forced with the surface mass balance (SMB) directly computed inside the EC-EARTH atmospheric module and accounting for the precipitation, the surface evaporation, and the melting of snow and ice over land ice. PISM returns the simulated basal melt, ice discharge and ice cover (extent and thickness) as boundary conditions to EC-EARTH. This coupled system is mass and energy conserving without being constrained by any anomaly correction or flux adjustment, and hence is suitable for investigation of ice sheet - climate feedbacks. Three multi-century experiments for warm climate scenarios under (1) the RCP85 climate forcing, (2) an abrupt 4xCO2 and (3) an idealized 1% per year CO2 increase are performed using the coupled model system. The experiments are compared with their counterparts of the standard CMIP5 simulations (without the interactive ice sheet) to evaluate the performance of the coupled system and to quantify the GrIS feedbacks. In particular, the evolution of the Greenland ice sheet under the warm climate and its impacts on the climate system are investigated. Freshwater fluxes from the Greenland ice sheet melt to the Arctic and North Atlantic basin and their influence on the ocean stratification and ocean circulation are analysed. The changes in the surface climate and the atmospheric circulation associated with the impact of the Greenland ice sheet changes are quantified. The interaction between the Greenland ice sheet and Arctic sea ice is also examined.

Cerebral Palsy: General Information. Fact Sheet Number 2 = La Paralisis Cerebral: Informacion General. Fact Sheet Number 18.

ERIC Educational Resources Information Center

Interstate Research Associates, McLean, VA.

This fact sheet on cerebral palsy is offered in both English and Spanish. First, it provides a definition and considers various causes (e.g., an insufficient amount of oxygen reaching the fetal or newborn brain). The fact sheet then offers incidence figures and explains characteristics of the three main types of cerebral palsy: spastic, athetoid,…

A Novel Method for Producing Light GMT Sheets by a Pneumatic Technique

NASA Astrophysics Data System (ADS)

Dai, H.-L.; Rao, Y.-N.

2015-09-01

A novel method for producing a kind of light glass-mat- reinforced thermoplastic (GMT) sheets by using a pneumatic technique is presented. The tensile and flexural properties of produced light GMT sheets, with various lengths of glass fibers and PP content, were determined experimentally. Results of the experimental investigation show that the light GMT sheets are fully suitable for engineering applications.

Effect of tail plasma sheet conditions on the penetration of the convection electric field in the inner magnetosphere: RCM simulations with self-consistent magnetic field

NASA Astrophysics Data System (ADS)

Gkioulidou, M.; Wang, C.; Lyons, L. R.; Wolf, R.

2009-12-01

Transport of plasma sheet particles into the inner magnetosphere is strongly affected by the penetration of the convection electric field, which is the result of the large-scale magnetosphere ionosphere electromagnetic coupling. This transport, on the other hand, results in plasma heating and magnetic field stretching, which become very significant in the inner plasma sheet (inside 20 RE). We have previously run simulations with the Rice Convection Model (RCM), using the Tsyganenko 96 magnetic field model, to investigate how the earthward penetration of electric field depends on plasma sheet conditions. Outer proton and electron sources at r ~20 RE, are based on 11 years of Geotail data, and realistically represent the mixture of cold and hot plasma sheet population as a function of MLT and interplanetary conditions. We found that shielding of the inner magnetosphere electric field is more efficient for a colder and denser plasma sheet, which is found following northward IMF, than for the hotter and more tenuous plasma sheet found following southward IMF. Our simulation results so far indicate further earthward penetration of plasma sheet particles in response to enhanced convection if the preceding IMF is southward, which leads to weaker electric field shielding. Recently we have integrated the RCM with a magnetic field solver to obtain magnetic fields that are in force balance with given plasma pressures in the equatorial plane. We expect the self-consistent magnetic field to have a pronounced dawn dusk asymmetry due to the asymmetric inner magnetospheric pressure. This should affect the radial distance and MLT of plasma sheet penetration into the inner magnetosphere. We are currently using this force-balanced and self-consistent model with our realistic boundary conditions to evaluate the dependence of the shielding timescale on pre-existing plasma sheet number density and temperature and to more quantitatively determine the correlation between the plasma sheet conditions and spatial distribution of the penetrating particles. Our results are potentially crucial to understanding the contribution of plasma sheet penetration to the development of the storm-time ring current.

Automated Rapid Prototyping of 3D Ceramic Parts

NASA Technical Reports Server (NTRS)

McMillin, Scott G.; Griffin, Eugene A.; Griffin, Curtis W.; Coles, Peter W. H.; Engle, James D.

2005-01-01

An automated system of manufacturing equipment produces three-dimensional (3D) ceramic parts specified by computational models of the parts. The system implements an advanced, automated version of a generic rapid-prototyping process in which the fabrication of an object having a possibly complex 3D shape includes stacking of thin sheets, the outlines of which closely approximate the horizontal cross sections of the object at their respective heights. In this process, the thin sheets are made of a ceramic precursor material, and the stack is subsequently heated to transform it into a unitary ceramic object. In addition to the computer used to generate the computational model of the part to be fabricated, the equipment used in this process includes: 1) A commercially available laminated-object-manufacturing machine that was originally designed for building woodlike 3D objects from paper and was modified to accept sheets of ceramic precursor material, and 2) A machine designed specifically to feed single sheets of ceramic precursor material to the laminated-object-manufacturing machine. Like other rapid-prototyping processes that utilize stacking of thin sheets, this process begins with generation of the computational model of the part to be fabricated, followed by computational sectioning of the part into layers of predetermined thickness that collectively define the shape of the part. Information about each layer is transmitted to rapid-prototyping equipment, where the part is built layer by layer. What distinguishes this process from other rapid-prototyping processes that utilize stacking of thin sheets are the details of the machines and the actions that they perform. In this process, flexible sheets of ceramic precursor material (called "green" ceramic sheets) suitable for lamination are produced by tape casting. The binder used in the tape casting is specially formulated to enable lamination of layers with little or no applied heat or pressure. The tape is cut into individual sheets, which are stacked in the sheet-feeding machine until used. The sheet-feeding machine can hold enough sheets for about 8 hours of continuous operation.

Energized Oxygen : Speiser Current Sheet Bifurcation

NASA Astrophysics Data System (ADS)

George, D. E.; Jahn, J. M.

2017-12-01

A single population of energized Oxygen (O+) is shown to produce a cross-tail bifurcated current sheet in 2.5D PIC simulations of the magnetotail without the influence of magnetic reconnection. Treatment of oxygen in simulations of space plasmas, specifically a magnetotail current sheet, has been limited to thermal energies despite observations of and mechanisms which explain energized ions. We performed simulations of a homogeneous oxygen background, that has been energized in a physically appropriate manner, to study the behavior of current sheets and magnetic reconnection, specifically their bifurcation. This work uses a 2.5D explicit Particle-In-a-Cell (PIC) code to investigate the dynamics of energized heavy ions as they stream Dawn-to-Dusk in the magnetotail current sheet. We present a simulation study dealing with the response of a current sheet system to energized oxygen ions. We establish a, well known and studied, 2-species GEM Challenge Harris current sheet as a starting point. This system is known to eventually evolve and produce magnetic reconnection upon thinning of the current sheet. We added a uniform distribution of thermal O+ to the background. This 3-species system is also known to eventually evolve and produce magnetic reconnection. We add one additional variable to the system by providing an initial duskward velocity to energize the O+. We also traced individual particle motion within the PIC simulation. Three main results are shown. First, energized dawn- dusk streaming ions are clearly seen to exhibit sustained Speiser motion. Second, a single population of heavy ions clearly produces a stable bifurcated current sheet. Third, magnetic reconnection is not required to produce the bifurcated current sheet. Finally a bifurcated current sheet is compatible with the Harris current sheet model. This work is the first step in a series of investigations aimed at studying the effects of energized heavy ions on magnetic reconnection. This work differs significantly from previous investigations involving heavy ions in that they are energized as opposed to being simply thermal. This is a variation based firmly on published in-situ measurements. It also differs in that a complete population is used as opposed to simply test particles in a magnetic field model.

Analysis of Magnetic Flux Rope Chains Embedded in Martian Current Sheets Using MAVEN Data

NASA Astrophysics Data System (ADS)

Bowers, C. F.; DiBraccio, G. A.; Brain, D.; Hara, T.; Gruesbeck, J.; Espley, J. R.; Connerney, J. E. P.; Halekas, J. S.

2017-12-01

The magnetotail of Mars is formed as the interplanetary magnetic field (IMF) drapes around the planet's conducting ionosphere and localized crustal magnetic fields. In this scenario, a cross-tail current sheet separates the sunward and anti-sunward tail lobes. This tail current sheet is a highly dynamic region where magnetic reconnection is able to occur between the oppositely oriented fields. Magnetic flux ropes, a by-product of magnetic reconnection in the tail or in the ionosphere characterized by their helical outer wraps and strong axial core field, are commonly observed in the Martian magnetotail. An initial study using Mars Global Surveyor measurements reported a chain of flux ropes in the tail. During this event, 3 flux ropes were observed during a single traversal of the tail current sheet with a duration of 4 minutes. Here, we perform a statistical survey of these chain-of-flux-rope events to characterize their occurrence in the tail current sheet using Mars Atmosphere and Volatile EvolutioN (MAVEN) data. We implement the well-established technique of Minimum Variance Analysis to confirm the helical structure of the flux ropes and also determine local current sheet orientation. Thorough visual examination of more than 1600 orbits has resulted in the identification of 784 tail current sheet traversals. We determine the current sheet thickness to be on the order of 100-1000 km. From these current sheet observations, a subset of 30 events include embedded chain of flux ropes within the current sheet structure. We find that 87% of these flux rope chain events are identified in the southern latitude regions of Mars, associated with crustal fields. Their location suggests that magnetic reconnection occurring near crustal fields may be the source of these flux ropes. These statistical measurements of both current sheets and associated flux rope chains provide information about the complex magnetospheric dynamics at Mars, and how these dynamics affect atmospheric loss to space.

Synthesis of porous sheet-like Co{sub 3}O{sub 4} microstructure by precipitation method and its potential applications in the thermal decomposition of ammonium perchlorate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu Shanshan; Jing Xiaoyan; Liu Jingyuan

2013-01-15

Porous sheet-like cobalt oxide (Co{sub 3}O{sub 4}) were successfully synthesized by precipitation method combined with calcination of cobalt hydroxide precursors. The structure, morphology and porosity properties of the products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption-desorption measurement. The as-prepared sheet-like microstructures were approximately 2-3 {mu}m in average diameter, and the morphology of the cobalt hydroxide precursors was retained after the calcination process. However, it appeared a large number of uniform pores in the sheets after calcination. In order to calculate the potential catalytic activity, the thermal decomposition of ammoniummore » perchlorate (AP) has been analyzed, in which cobalt oxide played a role of an additive and the porous sheet-like Co{sub 3}O{sub 4} microstructures exhibited high catalytic performance and considerable decrease in the thermal decomposition temperature of AP. Moreover, a formation mechanism for the sheet-like microstructures has been discussed. - Graphical abstract: Porous sheet-like Co{sub 3}O{sub 4} were synthesized by facile precipitation method combined with calcination of {beta}-Co(OH){sub 2} precursors. Thermogravimetric-differential scanning calorimetric analysis indicates potential catalytic activity in the thermal decomposition of ammonium perchlorate. Highlights: Black-Right-Pointing-Pointer Synthesis of sheet-like {beta}-Co(OH){sub 2} precursors by precipitation method. Black-Right-Pointing-Pointer Porous sheet-like Co{sub 3}O{sub 4} were obtained by calcining {beta}-Co(OH){sub 2} precursors. Black-Right-Pointing-Pointer The possible formation mechanism of porous sheet-like Co{sub 3}O{sub 4} has been discussed. Black-Right-Pointing-Pointer Porous sheet-like Co{sub 3}O{sub 4} decrease the thermal decomposition temperature of ammonium perchlorate.« less

Effect of cryopreservation on proliferation and differentiation of periodontal ligament stem cell sheets.

PubMed

Li, Mengying; Feng, Cheng; Gu, Xiuge; He, Qin; Wei, Fulan

2017-04-17

Cryopreservation has been extensively applied to the long-term storage of a diverse range of biological materials. However, no comprehensive study is currently available on the cryopreservation of periodontal ligament stem cell (PDLSC) sheets which have been suggested as excellent transplant materials for periodontal tissue regeneration. The aim of this study is to investigate the effect of cryopreservation on the structural integrity and functional viability of PDLSC sheets. PDLSC sheets prepared from extracted human molars were divided into two groups: the cryopreservation group (cPDLSC sheets) and the freshly prepared control group (fPDLSC sheets). The cPDLSC sheets were cryopreserved in a solution consisting of 90% fetal bovine serum and 10% dimethyl sulfoxide for 3 months. Cell viability and cell proliferation rates of PDLSCs in both groups were evaluated by cell viability assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, respectively. The multilineage differentiation potentials of the cells were assessed by von Kossa staining and Oil Red O staining. The chromosomal stability was examined by karyotype analysis. Moreover, the cell sheets in each group were transplanted subcutaneously into the dorsal site of nude mice, after which Sirius Red staining was performed to analyze the efficiency of tissue regeneration. The PDLSCs derived from both groups of cell sheets showed no significant difference in their viability, proliferative capacities, and multilineage differentiation potentials, as well as chromosomal stability. Furthermore, transplantation experiments based on a mouse model demonstrated that the cPDLSC sheets were equally effective in generating viable osteoid tissues in vivo as their freshly prepared counterparts. In both cases, the regenerated tissues showed similar network patterns of bone-like matrix. Our results offer convincing evidence that cryopreservation does not alter the biological properties of PDLSC sheets and could enhance their clinical utility in tissue regeneration.

Creation and Transplantation of an Adipose-derived Stem Cell (ASC) Sheet in a Diabetic Wound-healing Model.

PubMed

Kato, Yuka; Iwata, Takanori; Washio, Kaoru; Yoshida, Toshiyuki; Kuroda, Hozue; Morikawa, Shunichi; Hamada, Mariko; Ikura, Kazuki; Kaibuchi, Nobuyuki; Yamato, Masayuki; Okano, Teruo; Uchigata, Yasuko

2017-08-04

Artificial skin has achieved considerable therapeutic results in clinical practice. However, artificial skin treatments for wounds in diabetic patients with impeded blood flow or with large wounds might be prolonged. Cell-based therapies have appeared as a new technique for the treatment of diabetic ulcers, and cell-sheet engineering has improved the efficacy of cell transplantation. A number of reports have suggested that adipose-derived stem cells (ASCs), a type of mesenchymal stromal cell (MSC), exhibit therapeutic potential due to their relative abundance in adipose tissue and their accessibility for collection when compared to MSCs from other tissues. Therefore, ASCs appear to be a good source of stem cells for therapeutic use. In this study, ASC sheets from the epididymal adipose fat of normal Lewis rats were successfully created using temperature-responsive culture dishes and normal culture medium containing ascorbic acid. The ASC sheets were transplanted into Zucker diabetic fatty (ZDF) rats, a rat model of type 2 diabetes and obesity, that exhibit diminished wound healing. A wound was created on the posterior cranial surface, ASC sheets were transplanted into the wound, and a bilayer artificial skin was used to cover the sheets. ZDF rats that received ASC sheets had better wound healing than ZDF rats without the transplantation of ASC sheets. This approach was limited because ASC sheets are sensitive to dry conditions, requiring the maintenance of a moist wound environment. Therefore, artificial skin was used to cover the ASC sheet to prevent drying. The allogenic transplantation of ASC sheets in combination with artificial skin might also be applicable to other intractable ulcers or burns, such as those observed with peripheral arterial disease and collagen disease, and might be administered to patients who are undernourished or are using steroids. Thus, this treatment might be the first step towards improving the therapeutic options for diabetic wound healing.

Effect of Inductive Coil Geometry and Current Sheet Trajectory of a Conical Theta Pinch Pulsed Inductive Plasma Accelerator

NASA Technical Reports Server (NTRS)

Hallock, Ashley K.; Polzin, Kurt A.; Bonds, Kevin W.; Emsellem, Gregory D.

2011-01-01

Results are presented demonstrating the e ect of inductive coil geometry and current sheet trajectory on the exhaust velocity of propellant in conical theta pinch pulsed induc- tive plasma accelerators. The electromagnetic coupling between the inductive coil of the accelerator and a plasma current sheet is simulated, substituting a conical copper frustum for the plasma. The variation of system inductance as a function of plasma position is obtained by displacing the simulated current sheet from the coil while measuring the total inductance of the coil. Four coils of differing geometries were employed, and the total inductance of each coil was measured as a function of the axial displacement of two sep- arate copper frusta both having the same cone angle and length as the coil but with one compressed to a smaller size relative to the coil. The measured relationship between total coil inductance and current sheet position closes a dynamical circuit model that is used to calculate the resulting current sheet velocity for various coil and current sheet con gura- tions. The results of this model, which neglects the pinching contribution to thrust, radial propellant con nement, and plume divergence, indicate that in a conical theta pinch ge- ometry current sheet pinching is detrimental to thruster performance, reducing the kinetic energy of the exhausting propellant by up to 50% (at the upper bound for the parameter range of the study). The decrease in exhaust velocity was larger for coils and simulated current sheets of smaller half cone angles. An upper bound for the pinching contribution to thrust is estimated for typical operating parameters. Measurements of coil inductance for three di erent current sheet pinching conditions are used to estimate the magnetic pressure as a function of current sheet radial compression. The gas-dynamic contribution to axial acceleration is also estimated and shown to not compensate for the decrease in axial electromagnetic acceleration that accompanies the radial compression of the plasma in conical theta pinches.

SU-E-T-76: Comparing Homogeneity Between Gafchromic Film EBT2 and EBT3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mizuno, H; Sumida, I; Ogawa, K

2014-06-01

Purpose: We found out that homogeneity of EBT2 was different among lot numbers in previous study. Variation in local homogeneity of EBT3 among several lot numbers has not been reported. In this study, we investigated film homogeneity of Gafcrhomic EBT3 films compared with EBT2 films. Methods: All sheets from five lots were cut into 12 pieces to investigate film homogeneity, and were irradiated at 0.5, 2, and 3 Gy. To investigate intra- and inter-sheet uniformity, five sheets from five lots were exposed to 2 Gy: intra-sheet uniformity was evaluated by the coefficient of variation of homogeneity for all pieces ofmore » a single sheet, and inter-sheet uniformity was evaluated by the coefficient of variation of homogeneity among the same piece numbers in the five sheets. To investigate the difference of ADC value in various doses, a single sheet from each of five lots was irradiated at 0.5 Gy and 3 Gy in addition to 2 Gy. A scan resolution of 72 dots per inch (dpi) and color depth of 48-bit RGB were used. Films were analyzed by the inhouse software; Average of ADC value in center ROI and profile X and Y axis were measured. Results and Conclusion: Intra-sheet uniformity of non-irradiated EBT2 films were ranged from 0.1% to 0.4%, however that of irradiated EBT2 films were ranged from 0.2% to 1.5%. On the other hand, intra-sheet uniformity of irradiated and non-irradiated EBT3 films were from 0.2% to 0.6%. Inter-sheet uniformity of all films were less than 0.5%. It was interesting point that homogeneity of EBT3 between no-irradiated and irradiated films were similar value, whereas EBT2 had dose dependence of homogeneity in ADC value evaluation. These results suggested that EBT3 homogeneity was corrected by this feature.« less

Culturing bone marrow cells with dexamethasone and ascorbic acid improves osteogenic cell sheet structure.

PubMed

Akahane, M; Shimizu, T; Kira, T; Onishi, T; Uchihara, Y; Imamura, T; Tanaka, Y

2016-11-01

To assess the structure and extracellular matrix molecule expression of osteogenic cell sheets created via culture in medium with both dexamethasone (Dex) and ascorbic acid phosphate (AscP) compared either Dex or AscP alone. Osteogenic cell sheets were prepared by culturing rat bone marrow stromal cells in a minimal essential medium (MEM), MEM with AscP, MEM with Dex, and MEM with Dex and AscP (Dex/AscP). The cell number and messenger (m)RNA expression were assessed in vitro, and the appearance of the cell sheets was observed after mechanical retrieval using a scraper. β-tricalcium phosphate (β-TCP) was then wrapped with the cell sheets from the four different groups and subcutaneously implanted into rats. After mechanical retrieval, the osteogenic cell sheets from the MEM, MEM with AscP, and MEM with Dex groups appeared to be fragmented or incomplete structures. The cell sheets cultured with Dex/AscP remained intact after mechanical retrieval, without any identifiable tears. Culture with Dex/AscP increased the mRNA and protein expression of extracellular matrix proteins and cell number compared with those of the other three groups. More bridging bone formation was observed after transplantation of the β-TCP scaffold wrapped with cell sheets cultured with Dex/AscP, than in the other groups. These results suggest that culture with Dex/AscP improves the mechanical integrity of the osteogenic cell sheets, allowing retrieval of the confluent cells in a single cell sheet structure. This method may be beneficial when applied in cases of difficult tissue reconstruction, such as nonunion, bone defects, and osteonecrosis.Cite this article: M. Akahane, T. Shimizu, T. Kira, T. Onishi, Y. Uchihara, T. Imamura, Y. Tanaka. Culturing bone marrow cells with dexamethasone and ascorbic acid improves osteogenic cell sheet structure. Bone Joint Res 2016;5:569-576. DOI: 10.1302/2046-3758.511.BJR-2016-0013.R1. © 2016 Akahane et al.

Numerical simulation for the magnetic force distribution in electromagnetic forming of small size flat sheet

NASA Astrophysics Data System (ADS)

Chen, Xiaowei; Wang, Wenping; Wan, Min

2013-12-01

It is essential to calculate magnetic force in the process of studying electromagnetic flat sheet forming. Calculating magnetic force is the basis of analyzing the sheet deformation and optimizing technical parameters. Magnetic force distribution on the sheet can be obtained by numerical simulation of electromagnetic field. In contrast to other computing methods, the method of numerical simulation has some significant advantages, such as higher calculation accuracy, easier using and other advantages. In this paper, in order to study of magnetic force distribution on the small size flat sheet in electromagnetic forming when flat round spiral coil, flat rectangular spiral coil and uniform pressure coil are adopted, the 3D finite element models are established by software ANSYS/EMAG. The magnetic force distribution on the sheet are analyzed when the plane geometries of sheet are equal or less than the coil geometries under fixed discharge impulse. The results showed that when the physical dimensions of sheet are less than the corresponding dimensions of the coil, the variation of induced current channel width on the sheet will cause induced current crowding effect that seriously influence the magnetic force distribution, and the degree of inhomogeneity of magnetic force distribution is increase nearly linearly with the variation of induced current channel width; the small size uniform pressure coil will produce approximately uniform magnetic force distribution on the sheet, but the coil is easy to early failure; the desirable magnetic force distribution can be achieved when the unilateral placed flat rectangular spiral coil is adopted, and this program can be take as preferred one, because the longevity of flat rectangular spiral coil is longer than the working life of small size uniform pressure coil.

The Svalbard-Barents Sea ice-sheet - Historical, current and future perspectives

NASA Astrophysics Data System (ADS)

Ingólfsson, Ólafur; Landvik, Jon Y.

2013-03-01

The history of research on the Late Quaternary Svalbard-Barents Sea ice sheet mirrors the developments of ideas and the shifts of paradigms in glacial theory over the past 150 years. Since the onset of scientific research there in the early 19th Century, Svalbard has been a natural laboratory where ideas and concepts have been tested, and played an important (but rarely acknowledged) role in the break-through of the Ice Age theory in the 1870's. The history of how the scientific perception of the Svalbard-Barents sea ice sheet developed in the mid-20th Century also tells a story of how a combination of fairly scattered and often contradictory observational data, and through both deductive and inductive reasoning, could outline a major ice sheet that had left but few tangible fingerprints. Since the 1980's, with increased terrestrial stratigraphical data, ever more marine geological evidence and better chronological control of glacial events, our perception of the Svalbard-Barents Sea ice sheet has changed. The first reconstructions depicted it as a static, concentric, single-domed ice sheet, with ice flowing from an ice divide over the central northern Barents Sea that expanded and declined in response to large-scale, Late Quaternary climate fluctuations, and which was more or less in tune with other major Northern Hemisphere ice sheets. We now increasingly perceive it as a very dynamic, multidomed ice sheet, controlled by climate fluctuations, relative sea-level change, as well as subglacial topography, substrate properties and basal temperature. In this respect, the Svalbard-Barents Sea ice sheet will increasingly hold the key for understanding the dynamics and processes of how marine-based ice sheets build-up and decay.

Comparing Sources of Storm-Time Ring Current O+

NASA Astrophysics Data System (ADS)

Kistler, L. M.

2015-12-01

The first observations of the storm-time ring current composition using AMPTE/CCE data showed that the O+ contribution to the ring current increases significantly during storms. The ring current is predominantly formed from inward transport of the near-earth plasma sheet. Thus the increase of O+ in the ring current implies that the ionospheric contribution to the plasma sheet has increased. The ionospheric plasma that reaches the plasma sheet can come from both the cusp and the nightside aurora. The cusp outflow moves through the lobe and enters the plasma sheet through reconnection at the near-earth neutral line. The nightside auroral outflow has direct access to nightside plasma sheet. Using data from Cluster and the Van Allen Probes spacecraft, we compare the development of storms in cases where there is a clear input of nightside auroral outflow, and in cases where there is a significant cusp input. We find that the cusp input, which enters the tail at ~15-20 Re becomes isotropized when it crosses the neutral sheet, and becomes part of the hot (>1 keV) plasma sheet population as it convects inward. The auroral outflow, which enters the plasma sheet closer to the earth, where the radius of curvature of the field line is larger, does not isotropize or become significantly energized, but remains a predominantly field aligned low energy population in the inner magnetosphere. It is the hot plasma sheet population that gets accelerated to high enough energies in the inner magnetosphere to contribute strongly to the ring current pressure. Thus it appears that O+ that enters the plasma sheet further down the tail has a greater impact on the storm-time ring current than ions that enter closer to the earth.

How and when to terminate the Pleistocene ice ages?

NASA Astrophysics Data System (ADS)

Abe-Ouchi, A.; Saito, F.; Kawamura, K.; Takahashi, K.; Raymo, M. E.; Okuno, J.; Blatter, H.

2015-12-01

Climate change with wax and wane of large Northern Hemisphere ice sheet occurred in the past 800 thousand years characterized by 100 thousand year cycle with a large amplitude of sawtooth pattern, following a transition from a period of 40 thousand years cycle with small amplitude of ice sheet change at about 1 million years ago. Although the importance of insolation as the ultimate driver is now appreciated, the mechanism what determines timing and strength of terminations are far from clearly understood. Here we show, using comprehensive climate and ice-sheet models, that insolation and internal feedbacks between the climate, the ice sheets and the lithosphere-asthenosphere system explain the 100,000-year periodicity. The responses of equilibrium states of ice sheets to summer insolation show hysteresis, with the shape and position of the hysteresis loop playing a key part in determining the periodicities of glacial cycles. The hysteresis loop of the North American ice sheet is such that after inception of the ice sheet, its mass balance remains mostly positive through several precession cycles, whose amplitudes decrease towards an eccentricity minimum. The larger the ice sheet grows and extends towards lower latitudes, the smaller is the insolation required to make the mass balance negative. Therefore, once a large ice sheet is established, a moderate increase in insolation is sufficient to trigger a negative mass balance, leading to an almost complete retreat of the ice sheet within several thousand years. We discuss further the mechanism which determine the timing of ice age terminations by examining the role of astronomical forcing and change of atmospheric carbon dioxide contents through sensitivity experiments and comparison of several ice age cycles with different settings of astronomical forcings.

Influence of nanotopography on periodontal ligament stem cell functions and cell sheet based periodontal regeneration

PubMed Central

Gao, Hui; Li, Bei; Zhao, Lingzhou; Jin, Yan

2015-01-01

Periodontal regeneration is an important part of regenerative medicine, with great clinical significance; however, the effects of nanotopography on the functions of periodontal ligament (PDL) stem cells (PDLSCs) and on PDLSC sheet based periodontal regeneration have never been explored. Titania nanotubes (NTs) layered on titanium (Ti) provide a good platform to study this. In the current study, the influence of NTs of different tube size on the functions of PDLSCs was observed. Afterward, an ectopic implantation model using a Ti/cell sheets/hydroxyapatite (HA) complex was applied to study the effect of the NTs on cell sheet based periodontal regeneration. The NTs were able to enhance the initial PDLSC adhesion and spread, as well as collagen secretion. With the Ti/cell sheets/HA complex model, it was demonstrated that the PDLSC sheets were capable of regenerating the PDL tissue, when combined with bone marrow mesenchymal stem cell (BMSC) sheets and HA, without the need for extra soluble chemical cues. Simultaneously, the NTs improved the periodontal regeneration result of the ectopically implanted Ti/cell sheets/HA complex, giving rise to functionally aligned collagen fiber bundles. Specifically, much denser collagen fibers, with abundant blood vessels as well as cementum-like tissue on the Ti surface, which well-resembled the structure of natural PDL, were observed in the NT5 and NT10 sample groups. Our study provides the first evidence that the nanotopographical cues obviously influence the functions of PDLSCs and improve the PDLSC sheet based periodontal regeneration size dependently, which provides new insight to the periodontal regeneration. The Ti/cell sheets/HA complex may constitute a good model to predict the effect of biomaterials on periodontal regeneration. PMID:26150714

Progressive failure of sheeted rock slopes: the 2009–2010 Rhombus Wall rock falls in Yosemite Valley, California, USA

USGS Publications Warehouse

Stock, Greg M.; Martel, Stephen J.; Collins, Brian D.; Harp, Edwin L.

2012-01-01

Progressive rock-fall failures in natural rock slopes are common in many environments, but often elude detailed quantitative documentation and analysis. Here we present high-resolution photography, video, and laser scanning data that document spatial and temporal patterns of a 15-month-long sequence of at least 14 rock falls from the Rhombus Wall, a sheeted granitic cliff in Yosemite Valley, California. The rock-fall sequence began on 26 August 2009 with a small failure at the tip of an overhanging rock slab. Several hours later, a series of five rock falls totaling 736 m3progressed upward along a sheeting joint behind the overhanging slab. Over the next 3 weeks, audible cracking occurred on the Rhombus Wall, suggesting crack propagation, while visual monitoring revealed opening of a sheeting joint adjacent to the previous failure surface. On 14 September 2009 a 110 m3 slab detached along this sheeting joint. Additional rock falls between 30 August and 20 November 2010, totaling 187 m3, radiated outward from the initial failure area along cliff (sub)parallel sheeting joints. We suggest that these progressive failures might have been related to stress redistributions accompanying propagation of sheeting joints behind the cliff face. Mechanical analyses indicate that tensile stresses should occur perpendicular to the cliff face and open sheeting joints, and that sheeting joints should propagate parallel to a cliff face from areas of stress concentrations. The analyses also account for how sheeting joints can propagate to lengths many times greater than their depths behind cliff faces. We posit that as a region of failure spreads across a cliff face, stress concentrations along its margin will spread with it, promoting further crack propagation and rock falls.

Method of manufacturing aluminide sheet by thermomechanical processing of aluminide powders

DOEpatents

Hajaligol, Mohammad R.; Scorey, Clive; Sikka, Vinod K.; Deevi, Seetharama C.; Fleishhauer, Grier; Lilly, Jr., A. Clifton; German, Randall M.

2003-12-09

A powder metallurgical process of preparing a sheet from a powder having an intermetallic alloy composition such as an iron, nickel or titanium aluminide. The sheet can be manufactured into electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 4 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.0.05% Zr .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Ni, .ltoreq.0.75% C, .ltoreq.0.1% B, .ltoreq.1% submicron oxide particles and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1% rare earth metal, and/or .ltoreq.3% Cu. The process includes forming a non-densified metal sheet by consolidating a powder having an intermetallic alloy composition such as by roll compaction, tape casting or plasma spraying, forming a cold rolled sheet by cold rolling the non-densified metal sheet so as to increase the density and reduce the thickness thereof and annealing the cold rolled sheet. The powder can be a water, polymer or gas atomized powder which is subjecting to sieving and/or blending with a binder prior to the consolidation step. After the consolidation step, the sheet can be partially sintered. The cold rolling and/or annealing steps can be repeated to achieve the desired sheet thickness and properties. The annealing can be carried out in a vacuum furnace with a vacuum or inert atmosphere. During final annealing, the cold rolled sheet recrystallizes to an average grain size of about 10 to 30 .mu.m. Final stress relief annealing can be carried out in the B2 phase temperature range.

Thermomechanical processing of plasma sprayed intermetallic sheets

DOEpatents

Hajaligol, Mohammad R.; Scorey, Clive; Sikka, Vinod K.; Deevi, Seetharama C.; Fleischhauer, Grier; Lilly, Jr., A. Clifton; German, Randall M.

2001-01-01

A powder metallurgical process of preparing a sheet from a powder having an intermetallic alloy composition such as an iron, nickel or titanium aluminide. The sheet can be manufactured into electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 4 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.0.05% Zr .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Ni, .ltoreq.0.75% C, .ltoreq.0.1% B, .ltoreq.1% submicron oxide particles and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1% rare earth metal, and/or .ltoreq.3% Cu. The process includes forming a non-densified metal sheet by consolidating a powder having an intermetallic alloy composition such as by roll compaction, tape casting or plasma spraying, forming a cold rolled sheet by cold rolling the non-densified metal sheet so as to increase the density and reduce the thickness thereof and annealing the cold rolled sheet. The powder can be a water, polymer or gas atomized powder which is subjecting to sieving and/or blending with a binder prior to the consolidation step. After the consolidation step, the sheet can be partially sintered. The cold rolling and/or annealing steps can be repeated to achieve the desired sheet thickness and properties. The annealing can be carried out in a vacuum furnace with a vacuum or inert atmosphere. During final annealing, the cold rolled sheet recrystallizes to an average grain size of about 10 to 30 .mu.m. Final stress relief annealing can be carried out in the B2 phase temperature range.

Method of manufacturing aluminide sheet by thermomechanical processing of aluminide powders

DOEpatents

Hajaligol, Mohammad R.; Scorey, Clive; Sikka, Vinod K.; Deevi, Seetharama C.; Fleischhauer, Grier; Lilly, Jr., A. Clifton; German, Randall M.

2000-01-01

A powder metallurgical process of preparing a sheet from a powder having an intermetallic alloy composition such as an iron, nickel or titanium aluminide. The sheet can be manufactured into electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 4 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.0.05% Zr.ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Ni, .ltoreq.0.75% C, .ltoreq.0.1% B, .ltoreq.1% submicron oxide particles and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1% rare earth metal, and/or .ltoreq.3% Cu. The process includes forming a non-densified metal sheet by consolidating a powder having an intermetallic alloy composition such as by roll compaction, tape casting or plasma spraying, forming a cold rolled sheet by cold rolling the non-densified metal sheet so as to increase the density and reduce the thickness thereof and annealing the cold rolled sheet. The powder can be a water, polymer or gas atomized powder which is subjecting to sieving and/or blending with a binder prior to the consolidation step. After the consolidation step, the sheet can be partially sintered. The cold rolling and/or annealing steps can be repeated to achieve the desired sheet thickness and properties. The annealing can be carried out in a vacuum furnace with a vacuum or inert atmosphere. During final annealing, the cold rolled sheet recrystallizes to an average grain size of about 10 to 30 .mu.m. Final stress relief annealing can be carried out in the B2 phase temperature range.

Influence of nanotopography on periodontal ligament stem cell functions and cell sheet based periodontal regeneration.

PubMed

Gao, Hui; Li, Bei; Zhao, Lingzhou; Jin, Yan

2015-01-01

Periodontal regeneration is an important part of regenerative medicine, with great clinical significance; however, the effects of nanotopography on the functions of periodontal ligament (PDL) stem cells (PDLSCs) and on PDLSC sheet based periodontal regeneration have never been explored. Titania nanotubes (NTs) layered on titanium (Ti) provide a good platform to study this. In the current study, the influence of NTs of different tube size on the functions of PDLSCs was observed. Afterward, an ectopic implantation model using a Ti/cell sheets/hydroxyapatite (HA) complex was applied to study the effect of the NTs on cell sheet based periodontal regeneration. The NTs were able to enhance the initial PDLSC adhesion and spread, as well as collagen secretion. With the Ti/cell sheets/HA complex model, it was demonstrated that the PDLSC sheets were capable of regenerating the PDL tissue, when combined with bone marrow mesenchymal stem cell (BMSC) sheets and HA, without the need for extra soluble chemical cues. Simultaneously, the NTs improved the periodontal regeneration result of the ectopically implanted Ti/cell sheets/HA complex, giving rise to functionally aligned collagen fiber bundles. Specifically, much denser collagen fibers, with abundant blood vessels as well as cementum-like tissue on the Ti surface, which well-resembled the structure of natural PDL, were observed in the NT5 and NT10 sample groups. Our study provides the first evidence that the nanotopographical cues obviously influence the functions of PDLSCs and improve the PDLSC sheet based periodontal regeneration size dependently, which provides new insight to the periodontal regeneration. The Ti/cell sheets/HA complex may constitute a good model to predict the effect of biomaterials on periodontal regeneration.

Cultures of Schwann-like cells differentiated from adipose-derived stem cells on PDMS/MWNT sheets as a scaffold for peripheral nerve regeneration.

PubMed

Han, In Ho; Sun, Fangfang; Choi, Yoon Ji; Zou, Fengming; Nam, Kyoung Hyup; Cho, Won Ho; Choi, Byung Kwan; Song, Geun Sung; Koh, Kwangnak; Lee, Jaebeom

2015-11-01

Carbon nanotubes (CNTs) are promising candidates as novel scaffolds for peripheral nerve regeneration. Schwann cells (SCs) are attractive therapeutic targets due to their pivotal role in peripheral nerve regeneration, but primary SCs have limitations for clinical application. However, adipose-derived stem cells (ASCs) may differentiate into Schwann-like cells. The present study assesses the potential applicability of multiwall CNTs (MWNTs) composited with polydimethylsiloxane (PDMS), which were then seeded with differentiated adipose-derived stem cells (dASCs) to promote neuronal differentiation and growth. Aqueous MWNT dispersion was filtered, and the PDMS/MWNT sheets were prepared using a simple printing-transfer method. Characterization of PDMS/MWNT sheets indicated their unique physical properties, such as superior mechanical strength and electroconductivity, compared with bare PDMS sheets. ASCs were differentiated into Schwann-like cells using a mixture of glial growth factors. Dorsal root ganglion (DRG) neurons were co-cultured with SCs and dASCs on PDMS/MWNTs sheets or noncoated dishes. An alamar blue proliferation assay of dASC and SCs showed significantly more dASC and SCs cultured on PDMS/MWNT sheets at 48 h and 72 h than when cultured on noncoated dishes (p < 0.05). Additionally, when DRG were cultured on PDMS/MWNT sheets seeded with dASCs, the proliferation of DRG neurons and the longest neurite outgrowth length per neuron were significantly greater than when DRG were cultured on PDMS/MWNT sheets alone or on noncoated dishes seeded with SCs or dASCs (p < 0.05). Overall, PDMS/MWNT sheets exhibited excellent biocompatibility for culturing Schwann-like cells differentiated from ASCs. Seeding the dASCs on PDMS/MWNT sheets may produce synergistic effects in peripheral nerve regeneration, similarly to SCs. © 2015 Wiley Periodicals, Inc.

Development of a Cell Sheet Transportation Technique for Regenerative Medicine

PubMed Central

Oie, Yoshinori; Nozaki, Takayuki; Takayanagi, Hiroshi; Hara, Susumu; Hayashi, Ryuhei; Takeda, Shizu; Mori, Keisuke; Moriya, Noboru; Soma, Takeshi; Tsujikawa, Motokazu; Saito, Kazuo

2014-01-01

Purpose: A transportation technique for cell sheets is necessary to standardize regenerative medicine. The aim of this article is to develop and evaluate a new transportation technique for cell sheets. Material and Methods: We developed a transportation container with three basic functions: the maintenance of interior temperature, air pressure, and sterility. The interior temperature and air pressure were monitored by a recorder. Human oral mucosal epithelial cells obtained from two healthy volunteers were cultured on temperature-responsive culture dishes. The epithelial cell sheets were transported via an airplane between the Osaka University and Tohoku University using the developed cell transportation container. Histological and immunohistochemical analyses and flow cytometric analyses for cell viability and cell purity were performed for the cell sheets before and 12 h after transportation to assess the influence of transportation on the cell sheets. Sterility tests and screening for endotoxin and mycoplasma in the cell sheets were performed before and after transportation. Results: During transportation via an airplane, the temperature inside the container was maintained above 32°C, and the changes in air pressure remained within 10 hPa. The cell sheets were well stratified and successfully harvested before and after transportation. The expression patterns of keratin 3/76, p63, and MUC16 were equivalent before and after transportation. However, the expression of ZO-1 in the cell sheet after transportation was slightly weaker than that before transportation. The cell viability was 72.0% before transportation and 77.3% after transportation. The epithelial purity was 94.6% before transportation and 87.9% after transportation. Sterility tests and screening for endotoxin and mycoplasma were negative for all cell sheets. Conclusion: The newly developed transportation technique for air travel is essential technology for regenerative medicine and promotes the standardization and spread of regenerative therapies. PMID:24044382

The use of cell-sheet technique eliminates arrhythmogenicity of skeletal myoblast-based therapy to the heart with enhanced therapeutic effects.

PubMed

Narita, Takuya; Shintani, Yasunori; Ikebe, Chiho; Kaneko, Masahiro; Harada, Narumi; Tshuma, Nomathamsanqa; Takahashi, Kunihiko; Campbell, Niall G; Coppen, Steven R; Yashiro, Kenta; Sawa, Yoshiki; Suzuki, Ken

2013-09-20

Clinical application of skeletal myoblast transplantation has been curtailed due to arrhythmogenicity and inconsistent therapeutic benefits observed in previous studies. However, these issues may be solved by the use of a new cell-delivery mode. It is now possible to generate "cell-sheets" using temperature-responsive dishes without artificial scaffolds. This study aimed to validate the safety and efficacy of epicardial placement of myoblast-sheets (myoblast-sheet therapy) in treating heart failure. After coronary artery ligation in rats, the same numbers of syngeneic myoblasts were transplanted by intramyocardial injection or cell-sheet placement. Continuous radio-telemetry monitoring detected increased ventricular arrhythmias, including ventricular tachycardia, after intramyocardial injection compared to the sham-control, while these were abolished in myoblast-sheet therapy. This effect was conjunct with avoidance of islet-like cell-cluster formation that disrupts electrical conduction, and with prevention of increased arrhythmogenic substrates due to exaggerated inflammation. Persistent ectopic donor cells were found in the lung only after intramyocardial injection, strengthening the improved safety of myoblast-sheet therapy. In addition, myoblast-sheet therapy enhanced cardiac function, corresponding to a 9.2-fold increase in donor cell survival, compared to intramyocardial injection. Both methods achieved reduced infarct size, decreased fibrosis, attenuated cardiomyocyte hypertrophy, and increased neovascular formation, in association with myocardial upregulation of a group of relevant molecules. The pattern of these beneficial changes was similar between two methods, but the degree was more substantial after myoblast-sheet therapy. The cell-sheet technique enhanced safety and therapeutic efficacy of myoblast-based therapy, compared to the current method, thereby paving the way for clinical application. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Resistance spot welding of ultra-fine grained steel sheets produced by constrained groove pressing: Optimization and characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khodabakhshi, F.; Kazeminezhad, M., E-mail: mkazemi@sharif.edu; Kokabi, A.H.

2012-07-15

Constrained groove pressing as a severe plastic deformation method is utilized to produce ultra-fine grained low carbon steel sheets. The ultra-fine grained sheets are joined via resistance spot welding process and the characteristics of spot welds are investigated. Resistance spot welding process is optimized for welding of the sheets with different severe deformations and their results are compared with those of as-received samples. The effects of failure mode and expulsion on the performance of ultra-fine grained sheet spot welds have been investigated in the present paper and the welding current and time of resistance spot welding process according to thesemore » subjects are optimized. Failure mode and failure load obtained in tensile-shear test, microhardness, X-ray diffraction, transmission electron microscope and scanning electron microscope images have been used to describe the performance of spot welds. The region between interfacial to pullout mode transition and expulsion limit is defined as the optimum welding condition. The results show that optimum welding parameters (welding current and welding time) for ultra-fine grained sheets are shifted to lower values with respect to those for as-received specimens. In ultra-fine grained sheets, one new region is formed named recrystallized zone in addition to fusion zone, heat affected zone and base metal. It is shown that microstructures of different zones in ultra-fine grained sheets are finer than those of as-received sheets. - Highlights: Black-Right-Pointing-Pointer Resistance spot welding process is optimized for joining of UFG steel sheets. Black-Right-Pointing-Pointer Optimum welding current and time are decreased with increasing the CGP pass number. Black-Right-Pointing-Pointer Microhardness at BM, HAZ, FZ and recrystallized zone is enhanced due to CGP.« less

Antarctic climate and ice-sheet configuration during the early Pliocene interglacial at 4.23 Ma

NASA Astrophysics Data System (ADS)

Golledge, Nicholas R.; Thomas, Zoë A.; Levy, Richard H.; Gasson, Edward G. W.; Naish, Timothy R.; McKay, Robert M.; Kowalewski, Douglas E.; Fogwill, Christopher J.

2017-07-01

The geometry of Antarctic ice sheets during warm periods of the geological past is difficult to determine from geological evidence, but is important to know because such reconstructions enable a more complete understanding of how the ice-sheet system responds to changes in climate. Here we investigate how Antarctica evolved under orbital and greenhouse gas conditions representative of an interglacial in the early Pliocene at 4.23 Ma, when Southern Hemisphere insolation reached a maximum. Using offline-coupled climate and ice-sheet models, together with a new synthesis of high-latitude palaeoenvironmental proxy data to define a likely climate envelope, we simulate a range of ice-sheet geometries and calculate their likely contribution to sea level. In addition, we use these simulations to investigate the processes by which the West and East Antarctic ice sheets respond to environmental forcings and the timescales over which these behaviours manifest. We conclude that the Antarctic ice sheet contributed 8.6 ± 2.8 m to global sea level at this time, under an atmospheric CO2 concentration identical to present (400 ppm). Warmer-than-present ocean temperatures led to the collapse of West Antarctica over centuries, whereas higher air temperatures initiated surface melting in parts of East Antarctica that over one to two millennia led to lowering of the ice-sheet surface, flotation of grounded margins in some areas, and retreat of the ice sheet into the Wilkes Subglacial Basin. The results show that regional variations in climate, ice-sheet geometry, and topography produce long-term sea-level contributions that are non-linear with respect to the applied forcings, and which under certain conditions exhibit threshold behaviour associated with behavioural tipping points.

Deep drawability of Ti/resin/Ti laminated sheet

NASA Astrophysics Data System (ADS)

Hardada, Yasunroi; Hattori, Shuji

2017-10-01

Aiming to enhance functionality of titanium cup, the formability of titanium/resin/titanium laminated sheet by deep drawing was investigated. Although pure titanium has excellent corrosion resistance, the density of titanium is higher than that of light metals, such as aluminum and magnesium. Part of the titanium cup made of resin allows for weight reduction of the cup. Furthermore, the clad cup is more likely to have heat retention and protection against vibration characteristics. In the experiment, the materials were pure titanium and polycarbonate. The initial thickness of the sheet was 0.2 to 0.5 mm in thickness. A total plate thickness of the blank was 1.0 to 1.5 mm in thickness. The blank diameter is 70 mm. The laminated sheet was constituted by interposing resin between two titanium sheets. Each sheet in stacked condition was not joined each other. In the deep drawing process, the laminated sheet was employed and a flat sheet blank was formed into a circle by a punch. For the prevention of seizure in contact area between a drawing tool and titanium, titanium blank was treated by oxide coating. By this method, the fresh and clean titanium is not in direct contact with the die during the forming due to the existence of the oxide layer. The deep drawing was carried out to investigate the formability. The laminated sheet was successfully drawn without the cracks. The section of the drawn cup was observed to examine a formability of the resin sheet. The reduction rate of the thickness was less than 10%. It was found that the titanium/resin/titanium clad cup was successfully drawn.