A Modern Take on the RV Classics: N-body Analysis of GJ 876 and 55 Cnc

NASA Astrophysics Data System (ADS)

Nelson, Benjamin E.; Ford, E. B.; Wright, J.

2013-01-01

Over the past two decades, radial velocity (RV) observations have uncovered a diverse population of exoplanet systems, in particular a subset of multi-planet systems that exhibit strong dynamical interactions. To extract the model parameters (and uncertainties) accurately from these observations, one requires self-consistent n-body integrations and must explore a high-dimensional 7 x number of planets) parameter space, both of which are computationally challenging. Utilizing the power of modern computing resources, we apply our Radial velocity Using N-body Differential Evolution Markov Chain Monte Carlo code (RUN DEMCMC) to two landmark systems from early exoplanet surveys: GJ 876 and 55 Cnc. For GJ 876, we analyze the Keck HIRES (Rivera et al. 2010) and HARPS (Correia et al. 2010) data and constrain the distribution of the Laplace argument. For 55 Cnc, we investigate the orbital architecture based on a cumulative 1086 RV observations from various sources and transit constraints from Winn et al. 2011. In both cases, we also test for long-term orbital stability.

Recyclable organic solar cells on cellulose nanocrystal substrates

PubMed Central

Zhou, Yinhua; Fuentes-Hernandez, Canek; Khan, Talha M.; Liu, Jen-Chieh; Hsu, James; Shim, Jae Won; Dindar, Amir; Youngblood, Jeffrey P.; Moon, Robert J.; Kippelen, Bernard

2013-01-01

Solar energy is potentially the largest source of renewable energy at our disposal, but significant advances are required to make photovoltaic technologies economically viable and, from a life-cycle perspective, environmentally friendly, and consequently scalable. Cellulose nanomaterials are emerging high-value nanoparticles extracted from plants that are abundant, renewable, and sustainable. Here, we report on the first demonstration of efficient polymer solar cells fabricated on optically transparent cellulose nanocrystal (CNC) substrates. The solar cells fabricated on the CNC substrates display good rectification in the dark and reach a power conversion efficiency of 2.7%. In addition, we demonstrate that these solar cells can be easily separated and recycled into their major components using low-energy processes at room temperature, opening the door for a truly recyclable solar cell technology. Efficient and easily recyclable organic solar cells on CNC substrates are expected to be an attractive technology for sustainable, scalable, and environmentally-friendly energy production. PMID:23524333

Recyclable organic solar cells on cellulose nanocrystal substrates.

PubMed

Zhou, Yinhua; Fuentes-Hernandez, Canek; Khan, Talha M; Liu, Jen-Chieh; Hsu, James; Shim, Jae Won; Dindar, Amir; Youngblood, Jeffrey P; Moon, Robert J; Kippelen, Bernard

2013-01-01

Solar energy is potentially the largest source of renewable energy at our disposal, but significant advances are required to make photovoltaic technologies economically viable and, from a life-cycle perspective, environmentally friendly, and consequently scalable. Cellulose nanomaterials are emerging high-value nanoparticles extracted from plants that are abundant, renewable, and sustainable. Here, we report on the first demonstration of efficient polymer solar cells fabricated on optically transparent cellulose nanocrystal (CNC) substrates. The solar cells fabricated on the CNC substrates display good rectification in the dark and reach a power conversion efficiency of 2.7%. In addition, we demonstrate that these solar cells can be easily separated and recycled into their major components using low-energy processes at room temperature, opening the door for a truly recyclable solar cell technology. Efficient and easily recyclable organic solar cells on CNC substrates are expected to be an attractive technology for sustainable, scalable, and environmentally-friendly energy production.

Building an open-source robotic stereotaxic instrument.

PubMed

Coffey, Kevin R; Barker, David J; Ma, Sisi; West, Mark O

2013-10-29

This protocol includes the designs and software necessary to upgrade an existing stereotaxic instrument to a robotic (CNC) stereotaxic instrument for around $1,000 (excluding a drill), using industry standard stepper motors and CNC controlling software. Each axis has variable speed control and may be operated simultaneously or independently. The robot's flexibility and open coding system (g-code) make it capable of performing custom tasks that are not supported by commercial systems. Its applications include, but are not limited to, drilling holes, sharp edge craniotomies, skull thinning, and lowering electrodes or cannula. In order to expedite the writing of g-coding for simple surgeries, we have developed custom scripts that allow individuals to design a surgery with no knowledge of programming. However, for users to get the most out of the motorized stereotax, it would be beneficial to be knowledgeable in mathematical programming and G-Coding (simple programming for CNC machining). The recommended drill speed is greater than 40,000 rpm. The stepper motor resolution is 1.8°/Step, geared to 0.346°/Step. A standard stereotax has a resolution of 2.88 μm/step. The maximum recommended cutting speed is 500 μm/sec. The maximum recommended jogging speed is 3,500 μm/sec. The maximum recommended drill bit size is HP 2.

Molecular engineering of fracture energy dissipating sacrificial bonds into cellulose nanocrystal nanocomposites.

PubMed

McKee, Jason R; Huokuna, Johannes; Martikainen, Lahja; Karesoja, Mikko; Nykänen, Antti; Kontturi, Eero; Tenhu, Heikki; Ruokolainen, Janne; Ikkala, Olli

2014-05-12

Even though nanocomposites have provided a plethora of routes to increase stiffness and strength, achieving increased toughness with suppressed catastrophic crack growth has remained more challenging. Inspired by the concepts of mechanically excellent natural nanomaterials, one-component nanocomposites were fabricated involving reinforcing colloidal nanorod cores with polymeric grafts containing supramolecular binding units. The concept is based on mechanically strong native cellulose nanocrystals (CNC) grafted with glassy polymethacrylate polymers, with side chains that contain 2-ureido-4[1H]-pyrimidone (UPy) pendant groups. The interdigitation of the grafts and the ensuing UPy hydrogen bonds bind the nanocomposite network together. Under stress, UPy groups act as sacrificial bonds: simultaneously providing adhesion between the CNCs while allowing them to first orient and then gradually slide past each other, thus dissipating fracture energy. We propose that this architecture involving supramolecular binding units within side chains of polymer grafts attached to colloidal reinforcements opens generic approaches for tough nanocomposites. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Camp Upshur, Marine Corps Base Quantico, VA Architectural Survey

DTIC Science & Technology

2009-08-01

MIPR) M9301509MPFE007, dated 21 November 2008. The MCB Quantico technical monitor was John Haynes, Archeologist. The work was performed by the...Manager was Adam Smith. Dr. Christopher White is Chief, CN-C, and Dr. John Bandy is Chief, CN. The Deputy Director of CERL is Dr. Kirankumar V...Previous work reported in “Historical Resource Survey and Evaluation, Marine Corps Base Quantico, Virginia” John Milner Associates, 2008 and on

Concurrent Collections (CnC): A new approach to parallel programming

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

Knobe, Kathleen

2010-05-07

A common approach in designing parallel languages is to provide some high level handles to manipulate the use of the parallel platform. This exposes some aspects of the target platform, for example, shared vs. distributed memory. It may expose some but not all types of parallelism, for example, data parallelism but not task parallelism. This approach must find a balance between the desire to provide a simple view for the domain expert and provide sufficient power for tuning. This is hard for any given architecture and harder if the language is to apply to a range of architectures. Either simplicitymore » or power is lost. Instead of viewing the language design problem as one of providing the programmer with high level handles, we view the problem as one of designing an interface. On one side of this interface is the programmer (domain expert) who knows the application but needs no knowledge of any aspects of the platform. On the other side of the interface is the performance expert (programmer or program) who demands maximal flexibility for optimizing the mapping to a wide range of target platforms (parallel / serial, shared / distributed, homogeneous / heterogeneous, etc.) but needs no knowledge of the domain. Concurrent Collections (CnC) is based on this separation of concerns. The talk will present CnC and its benefits. About the speaker. Kathleen Knobe has focused throughout her career on parallelism especially compiler technology, runtime system design and language design. She worked at Compass (aka Massachusetts Computer Associates) from 1980 to 1991 designing compilers for a wide range of parallel platforms for Thinking Machines, MasPar, Alliant, Numerix, and several government projects. In 1991 she decided to finish her education. After graduating from MIT in 1997, she joined Digital Equipment’s Cambridge Research Lab (CRL). She stayed through the DEC/Compaq/HP mergers and when CRL was acquired and absorbed by Intel. She currently works in the Software and Services Group / Technology Pathfinding and Innovation.« less

Concurrent Collections (CnC): A new approach to parallel programming

ScienceCinema

Knobe, Kathleen

2018-04-16

A common approach in designing parallel languages is to provide some high level handles to manipulate the use of the parallel platform. This exposes some aspects of the target platform, for example, shared vs. distributed memory. It may expose some but not all types of parallelism, for example, data parallelism but not task parallelism. This approach must find a balance between the desire to provide a simple view for the domain expert and provide sufficient power for tuning. This is hard for any given architecture and harder if the language is to apply to a range of architectures. Either simplicity or power is lost. Instead of viewing the language design problem as one of providing the programmer with high level handles, we view the problem as one of designing an interface. On one side of this interface is the programmer (domain expert) who knows the application but needs no knowledge of any aspects of the platform. On the other side of the interface is the performance expert (programmer or program) who demands maximal flexibility for optimizing the mapping to a wide range of target platforms (parallel / serial, shared / distributed, homogeneous / heterogeneous, etc.) but needs no knowledge of the domain. Concurrent Collections (CnC) is based on this separation of concerns. The talk will present CnC and its benefits. About the speaker. Kathleen Knobe has focused throughout her career on parallelism especially compiler technology, runtime system design and language design. She worked at Compass (aka Massachusetts Computer Associates) from 1980 to 1991 designing compilers for a wide range of parallel platforms for Thinking Machines, MasPar, Alliant, Numerix, and several government projects. In 1991 she decided to finish her education. After graduating from MIT in 1997, she joined Digital Equipment’s Cambridge Research Lab (CRL). She stayed through the DEC/Compaq/HP mergers and when CRL was acquired and absorbed by Intel. She currently works in the Software and Services Group / Technology Pathfinding and Innovation.

Improvement of Polylactide Properties through Cellulose Nanocrystals Embedded in Poly(Vinyl Alcohol) Electrospun Nanofibers.

PubMed

López de Dicastillo, Carol; Garrido, Luan; Alvarado, Nancy; Romero, Julio; Palma, Juan Luis; Galotto, Maria Jose

2017-05-11

Electrospun nanofibers of poly (vinyl alcohol) (PV) were obtained to improve dispersion of cellulose nanocrystals (CNC) within hydrophobic biopolymeric matrices, such as poly(lactic acid) (PLA). Electrospun nanofibers (PV/CNC) n were successfully obtained with a final concentration of 23% ( w / w ) of CNC. Morphological, structural and thermal properties of developed CNC and electrospun nanofibers were characterized. X-ray diffraction and thermal analysis revealed that the crystallinity of PV was reduced by the electrospinning process, and the incorporation of CNC increased the thermal stability of biodegradable nanofibers. Interactions between CNC and PV polymer also enhanced the thermal stability of CNC and improved the dispersion of CNC within the PLA matrix. PLA materials with CNC lyophilized were also casted in order to compare the properties with materials based on CNC containing nanofibers. Nanofibers and CNC were incorporated into PLA at three concentrations: 0.5%, 1% and 3% (CNC respect to polymer weight) and nanocomposites were fully characterized. Overall, nanofibers containing CNC positively modified the physical properties of PLA materials, such as the crystallinity degree of PLA which was greatly enhanced. Specifically, materials with 1% nanofiber 1PLA(PV/CNC) n presented highest improvements related to mechanical and barrier properties; elongation at break was enhanced almost four times and the permeation of oxygen was reduced by approximately 30%.

Improvement of Polylactide Properties through Cellulose Nanocrystals Embedded in Poly(Vinyl Alcohol) Electrospun Nanofibers

PubMed Central

López de Dicastillo, Carol; Garrido, Luan; Alvarado, Nancy; Romero, Julio; Palma, Juan Luis; Galotto, Maria Jose

2017-01-01

Electrospun nanofibers of poly (vinyl alcohol) (PV) were obtained to improve dispersion of cellulose nanocrystals (CNC) within hydrophobic biopolymeric matrices, such as poly(lactic acid) (PLA). Electrospun nanofibers (PV/CNC)n were successfully obtained with a final concentration of 23% (w/w) of CNC. Morphological, structural and thermal properties of developed CNC and electrospun nanofibers were characterized. X-ray diffraction and thermal analysis revealed that the crystallinity of PV was reduced by the electrospinning process, and the incorporation of CNC increased the thermal stability of biodegradable nanofibers. Interactions between CNC and PV polymer also enhanced the thermal stability of CNC and improved the dispersion of CNC within the PLA matrix. PLA materials with CNC lyophilized were also casted in order to compare the properties with materials based on CNC containing nanofibers. Nanofibers and CNC were incorporated into PLA at three concentrations: 0.5%, 1% and 3% (CNC respect to polymer weight) and nanocomposites were fully characterized. Overall, nanofibers containing CNC positively modified the physical properties of PLA materials, such as the crystallinity degree of PLA which was greatly enhanced. Specifically, materials with 1% nanofiber 1PLA(PV/CNC)n presented highest improvements related to mechanical and barrier properties; elongation at break was enhanced almost four times and the permeation of oxygen was reduced by approximately 30%. PMID:28492470

cncRNAs: Bi-functional RNAs with protein coding and non-coding functions

PubMed Central

Kumari, Pooja; Sampath, Karuna

2015-01-01

For many decades, the major function of mRNA was thought to be to provide protein-coding information embedded in the genome. The advent of high-throughput sequencing has led to the discovery of pervasive transcription of eukaryotic genomes and opened the world of RNA-mediated gene regulation. Many regulatory RNAs have been found to be incapable of protein coding and are hence termed as non-coding RNAs (ncRNAs). However, studies in recent years have shown that several previously annotated non-coding RNAs have the potential to encode proteins, and conversely, some coding RNAs have regulatory functions independent of the protein they encode. Such bi-functional RNAs, with both protein coding and non-coding functions, which we term as ‘cncRNAs’, have emerged as new players in cellular systems. Here, we describe the functions of some cncRNAs identified from bacteria to humans. Because the functions of many RNAs across genomes remains unclear, we propose that RNAs be classified as coding, non-coding or both only after careful analysis of their functions. PMID:26498036

Formulation and Stabilization of Concentrated Edible Oil-in-Water Emulsions Based on Electrostatic Complexes of a Food-Grade Cationic Surfactant (Ethyl Lauroyl Arginate) and Cellulose Nanocrystals.

PubMed

Bai, Long; Xiang, Wenchao; Huan, Siqi; Rojas, Orlando J

2018-05-14

We report on high-internal-phase, oil-in-water Pickering emulsions that are stable against coalescence during storage. Viscous, edible oil (sunflower) was emulsified by combining naturally derived cellulose nanocrystals (CNCs) and a food-grade, biobased cationic surfactant obtained from lauric acid and L-arginine (ethyl lauroyl arginate, LAE). The interactions between CNC and LAE were elucidated by isothermal titration calorimetry (ITC) and supplementary techniques. LAE adsorption on CNC surfaces and its effect on nanoparticle electrostatic stabilization, aggregation state, and emulsifying ability was studied and related to the properties of resultant oil-in-water emulsions. Pickering systems with tunable droplet diameter and stability against oil coalescence during long-term storage were controllably achieved depending on LAE loading. The underlying stabilization mechanism was found to depend on the type of complex formed, the LAE structures adsorbed on the cellulose nanoparticles (as unimer or as adsorbed admicelles), the presence of free LAE in the aqueous phase, and the equivalent alkane number of the oil phase (sunflower and dodecane oils were compared). The results extend the potential of CNC in the formulation of high-quality and edible Pickering emulsions. The functional properties imparted by LAE, a highly effective molecule against food pathogens and spoilage organisms, open new opportunities in food, cosmetics, and pharmaceutical applications, where the presence of CNC plays a critical role in achieving synergistic effects with LAE.

Cellulose nanocrystals as templates for cetyltrimethylammonium bromide mediated synthesis of Ag nanoparticles and their novel use in PLA films.

PubMed

Yalcinkaya, E E; Puglia, D; Fortunati, E; Bertoglio, F; Bruni, G; Visai, L; Kenny, J M

2017-02-10

In the present paper, we reported how cellulose nanocrystals (CNC) from microcrystalline cellulose have the capacity to assist in the synthesis of metallic nanoparticles chains. A cationic surfactant, cetyltrimethylammonium bromide (CTAB), was used as modifier for CNC surface. Silver nanoparticles were synthesized on CNC, and nanoparticle density and size were optimized by varying concentrations of nitrate and reducing agents, and the reduction time. The experimental conditions were optimized for the synthesis and the resulting Ag grafted CNC (Ag-g-CNC) were characterized by means of TGA, SEM, FTIR and XRD, and then introduced in PLA matrix. PLA nanocomposite containing silver grafted cellulose nanocrystals (PLA/0.5Ag-g-1CNC) was characterized by optical and thermal analyses and the obtained data were compared with results from PLA nanocomposites containing 1% wt. of CNC (PLA/1CNC), 0.5% wt. of silver nanoparticles (PLA/0.5Ag) and hybrid system containing CNC and silver in the same amount (PLA/1CNC/0.5Ag). The results demonstrated that grafting of silver nanoparticles on CNC positively affected the thermal degradation process and cold crystallization processes of PLA matrix. Finally, the antibacterial activity of the different systems was studied at various incubation times and temperatures, showing the best performance for PLA/1CNC/0.5Ag based nanocomposite. Copyright © 2016 Elsevier Ltd. All rights reserved.

Computer-Numerical-Control and the EMCO Compact 5 Lathe.

ERIC Educational Resources Information Center

Mullen, Frank M.

This laboratory manual is intended for use in teaching computer-numerical-control (CNC) programming using the Emco Maier Compact 5 Lathe. Developed for use at the postsecondary level, this material contains a short introduction to CNC machine tools. This section covers CNC programs, CNC machine axes, and CNC coordinate systems. The following…

Preparation and physical properties of tara gum film reinforced with cellulose nanocrystals.

PubMed

Ma, Qianyun; Hu, Dongying; Wang, Lijuan

2016-05-01

Cellulose nanocrystals (CNC) prepared from microcrystalline cellulose were blended in tara gum solution to prepare nanocomposite films. The morphology, crystallinity, and thermal properties of the CNC and films were evaluated by using transmission electron microscopy, X-ray diffractometry, and thermogravimetric analysis, respectively. The resultant CNC was rod-shaped with diameters of around 8.6 nm. The effect of CNC content on physical and thermal properties of films was studied. The composite film tensile strength increased from 27.86 to 65.73 MPa, elastic modulus increased from 160.98 MPa to 882.49 MPa and the contact angle increased from 55.8° to 98.7° with increasing CNC content from 0 to 6 wt%. However, CNC addition increased the thermal stability slightly and CNC content above 6 wt% decreased the tensile strength by CNC aggregation in the matrix. The nanocomposite film containing 6 wt% CNC possessed the highest light transmittance, mechanical properties, and lowest oxygen permeability. CNC addition is a suitable method to modify tara gum matrix polymer properties. Copyright © 2016 Elsevier B.V. All rights reserved.

Postotic and preotic cranial neural crest cells differently contribute to thyroid development.

PubMed

Maeda, Kazuhiro; Asai, Rieko; Maruyama, Kazuaki; Kurihara, Yukiko; Nakanishi, Toshio; Kurihara, Hiroki; Miyagawa-Tomita, Sachiko

2016-01-01

Thyroid development and formation vary among species, but in most species the thyroid morphogenesis consists of five stages: specification, budding, descent, bilobation and folliculogenesis. The detailed mechanisms of these stages have not been fully clarified. During early development, the cranial neural crest (CNC) contributes to the thyroid gland. The removal of the postotic CNC (corresponding to rhombomeres 6, 7 and 8, also known as the cardiac neural crest) results in abnormalities of the cardiovascular system, thymus, parathyroid glands, and thyroid gland. To investigate the influence of the CNC on thyroid bilobation process, we divided the CNC into two regions, the postotic CNC and the preotic CNC (from the mesencephalon to rhombomere 5) regions and examined. We found that preotic CNC-ablated embryos had a unilateral thyroid lobe, and confirmed the presence of a single lobe or the absence of lobes in postotic CNC-ablated chick embryos. The thyroid anlage in each region-ablated embryos was of a normal size at the descent stage, but at a later stage, the thyroid in preotic CNC-ablated embryos was of a normal size, conflicting with a previous report in which the thyroid was reduced in size in the postotic CNC-ablated embryos. The postotic CNC cells differentiated into connective tissues of the thyroid in quail-to-chick chimeras. In contrast, the preotic CNC cells did not differentiate into connective tissues of the thyroid. We found that preotic CNC cells encompassed the thyroid anlage from the specification stage to the descent stage. Finally, we found that endothelin-1 and endothelin type A receptor-knockout mice and bosentan (endothelin receptor antagonist)-treated chick embryos showed bilobation anomalies that included single-lobe formation. Therefore, not only the postotic CNC, but also the preotic CNC plays an important role in thyroid morphogenesis. Copyright © 2015 Elsevier Inc. All rights reserved.

Synthesis and Fabrication of Nanocomposite Fibers of Collagen-Cellulose Nanocrystals by Coelectrocompaction.

PubMed

Cudjoe, Elvis; Younesi, Mousa; Cudjoe, Edward; Akkus, Ozan; Rowan, Stuart J

2017-04-10

An electrochemical process has been used to compact cellulose nanocrystals (CNC) and access aligned micron-sized CNC fibers. Placing a current across aqueous solutions of carboxylic acid functionalized CNCs (t-CNC-COOH) or carboxylic acid/primary amine functionalized CNCs (t-CNC-COOH-NH 2 ) creates a pH gradient between the electrodes, which results in the migration and concentration of the CNC fibers at their isoelectric point. By matching the carboxylic acid/amine ratio of CNCs and collagen (ca. 30:70 carboxylic acid:amine ratio), it is possible to coelectrocompact both nanofibers and access aligned nanocomposite fibers. t-CNC-COOH-NH 2 /collagen fibers showed a maximum increase in mechanical properties at 5 wt % of t-CNC-COOH-NH 2 . Compared to collagen/CNC films which have no alignment in the plane of the films, the tensile properties of the aligned fibers show a significant enhancement in the wet mechanical properties (40 MPa vs 230 MPa) for the 5 wt % of t-CNC-COOH-NH 2 /collagen films and fiber, respectively.

Investigation into the role of canopy structure traits and plant functional types in modulating the correlation between canopy nitrogen and reflectance in a temperate forest in northeast China

NASA Astrophysics Data System (ADS)

Yu, Quanzhou; Wang, Shaoqiang; Zhou, Lei

2017-10-01

A precise estimate of canopy leaf nitrogen concentration (CNC, based on dry mass) is important for researching the carbon assimilation capability of forest ecosystems. Hyperspectral remote sensing technology has been applied to estimate regional CNC, which can adjust forest photosynthetic capacity and carbon uptake. However, the relationship between forest CNC and canopy spectral reflectance as well as its mechanism is still poorly understood. Using measured CNC, canopy structure and species composition data, four vegetation indices (VIs), and near-infrared reflectance (NIR) derived from EO-1 Hyperion imagery, we investigated the role of canopy structure traits and plant functional types (PFTs) in modulating the correlation between CNC and canopy reflectance in a temperate forest in northeast China. A plot-scale forest structure indicator, named broad foliar dominance index (BFDI), was introduced to provide forest canopy structure and coniferous and broadleaf species composition. Then, we revealed the response of forest canopy reflectance spectrum to BFDI and CNC. Our results showed that leaf area index had no significant effect on NIR (P>0.05) but indicated that there was a significant correlation (R2=0.76, P<0.0001) between CNC and BFDI. NIR had a more significant correlation with BFDI than with CNC for all PFTs, but it had no obvious correlation with CNC for single PFT. Partial correlation analysis showed that four VIs had better correlations with BFDI than with CNC. When the effect of BFDI was removed, the partial correlation between CNC and NIR was insignificant (R=0.273, P>0.05). On the contrary, removing the CNC effect, the partial correlation between BFDI and NIR was positively significant (R=0.69, P<0.0001). These findings proved that canopy structure and coniferous and broadleaf species composition had a greater influence on the remote sensing signal than canopy nitrogen concentration. The functional convergence of plant traits resulted in the relation of CNC and canopy structure and determined the positive correlation between CNC and NIR. We maintain that the repeatable relationship between CNC and NIR can be used in the remote sensing retrieval of CNC during various forest types. Nevertheless, the relationship cannot be considered as a feasible approach of CNC estimation for a single PFT.

An Open-Access Educational Tool for Teaching Motion Dynamics in Multi-Axis Servomotor Control

ERIC Educational Resources Information Center

Rivera-Guillen, J. R.; de Jesus Rangel-Magdaleno, J.; de Jesus Romero-Troncoso, R.; Osornio-Rios, R. A.; Guevara-Gonzalez, R. G.

2012-01-01

Servomotors are widely used in computerized numerically controlled (CNC) machines, hence motion control is a major topic covered in undergraduate/graduate engineering courses. Despite the fact that several syllabi include the motion dynamics topic in their courses, there are neither suitable tools available for designing and simulating multi-axis…

Stable Aqueous Foams from Cellulose Nanocrystals and Methyl Cellulose.

PubMed

Hu, Zhen; Xu, Richard; Cranston, Emily D; Pelton, Robert H

2016-12-12

The addition of cellulose nanocrystals (CNC) greatly enhanced the properties of methylcellulose (MC) stabilized aqueous foams. CNC addition decreased air bubble size, initial foam densities and drainage rates. Mixtures of 2 wt % CNC + 0.5 wt % MC gave the lowest density foams. This composition sits near the onset of nematic phase formation and also near the overlap concentration of methylcellulose. More than 94% of the added CNC particles remained in the foam phase, not leaving with the draining water. We propose that the nanoscale CNC particles bind to the larger MC coils both in solution and with MC at the air/water interface, forming weak gels that stabilize air bubbles. Wet CNC-MC foams were sufficiently robust to withstand high temperature (70 °C for 6 h) polymerization of water-soluble monomers giving macroporous CNC composite hydrogels based on acrylamide (AM), 2-hydroxyethyl methacrylate (HEMA), or polyethylene glycol diacrylate (PEGDA). At high temperatures, the MC was present as a fibrillar gel phase reinforced by CNC particles, explaining the very high foam stability. Finally, our CNC-MC foams are based on commercially available forms of CNC and MC, already approved for many applications. This is a "shovel-ready" technology.

Effect of cellulose nanocrystals (CNC) on rheological and mechanical properties and crystallization behavior of PLA/CNC nanocomposites.

PubMed

Kamal, Musa R; Khoshkava, Vahid

2015-06-05

In earlier work, we reported that spray freeze drying of cellulose nanocrystals (CNC) yields porous agglomerate structures. On the other hand, the conventional spray dried CNC (CNCSD) and the freeze dried CNC (CNCFD) produce compact solid structures with very low porosity. As it is rather difficult to obtain direct microscopic evidence of the quality of dispersion of CNC in polymer nanocomposites, it was shown that supporting evidence of the quality and influence of dispersion in a polypropylene (PP)/CNC nanocomposite could be obtained by studying the rheological behavior, mechanical properties and crystallization characteristics of PP/CNC nanocomposites. In an effort to produce a sustainable, fully biosourced, biodegradable nanocomposite, this manuscript presents the results of a study of the rheological, mechanical and crystallization behavior of PLA/CNCSFD nanocomposites obtained by melt processing. The results are analyzed to determine CNC network formation, rheological percolation threshold concentrations, mechanical properties in the rubbery and glassy states, and the effect of CNCSFD on crystalline nucleation and crystallization rates of PLA. These results suggest that the porosity and network structure of CNCSFD agglomerates contribute significantly to good dispersion of CNC in the PLA matrix. Copyright © 2015 Elsevier Ltd. All rights reserved.

Research on ARM Numerical Control System

NASA Astrophysics Data System (ADS)

Wei, Xu; JiHong, Chen

Computerized Numerical Control (CNC) machine tools is the foundation of modern manufacturing systems, whose advanced digital technology is the key to solve the problem of sustainable development of machine tool manufacturing industry. The paper is to design CNC system embedded on ARM and indicates the hardware design and the software systems supported. On the hardware side: the driving chip of the motor control unit, as the core of components, is MCX314AL of DSP motion control which is developed by NOVA Electronics Co., Ltd. of Japan. It make convenient to control machine because of its excellent performance, simple interface, easy programming. On the Software side, the uC/OS-2 is selected as the embedded operating system of the open source, which makes a detailed breakdown of the modules of the CNC system. Those priorities are designed according to their actual requirements. The ways of communication between the module and the interrupt response are so different that it guarantees real-time property and reliability of the numerical control system. Therefore, it not only meets the requirements of the current social precision machining, but has good man-machine interface and network support to facilitate a variety of craftsmen use.

An overview on STEP-NC compliant controller development

NASA Astrophysics Data System (ADS)

Othman, M. A.; Minhat, M.; Jamaludin, Z.

2017-10-01

The capabilities of conventional Computer Numerical Control (CNC) machine tools as termination organiser to fabricate high-quality parts promptly, economically and precisely are undeniable. To date, most CNCs follow the programming standard of ISO 6983, also called G & M code. However, in fluctuating shop floor environment, flexibility and interoperability of current CNC system to react dynamically and adaptively are believed still limited. This outdated programming language does not explicitly relate to each other to have control of arbitrary locations other than the motion of the block-by-block. To address this limitation, new standard known as STEP-NC was developed in late 1990s and is formalized as an ISO 14649. It adds intelligence to the CNC in term of interoperability, flexibility, adaptability and openness. This paper presents an overview of the research work that have been done in developing a STEP-NC controller standard and the capabilities of STEP-NC to overcome modern manufacturing demands. Reviews stated that most existing STEP-NC controller prototypes are based on type 1 and type 2 implementation levels. There are still lack of effort being done to develop type 3 and type 4 STEP-NC compliant controller.

Polymer composites reinforced by locking-in a liquid-crystalline assembly of cellulose nanocrystallites.

PubMed

Tatsumi, Mio; Teramoto, Yoshikuni; Nishio, Yoshiyuki

2012-05-14

An attempt was made to synthesize novel composites comprising poly(2-hydroxyethyl methacrylate) (PHEMA) and cellulose nanocrystallites (CNC) (acid-treated cotton microfibrils) from suspensions of CNC in an aqueous 2-hydroxyethyl methacrylate (HEMA) monomer solution. The starting suspensions (∼5 wt % CNC) separated into an isotropic upper phase and an anisotropic bottom one in the course of quiescent standing. By way of polymerization of HEMA in different phase situations of the suspensions, we obtained films of three polymer composites, PHEMA-CNC(iso), PHEMA-CNC(aniso), and PHEMA-CNC(mix), coming from the isotropic phase, anisotropic phase, and embryonic nonseparating mixture, respectively. All the composites were transparent and, more or less, birefringent under a polarized optical microscope. A fingerprint texture typical of cholesteric liquid crystals of longer pitch spread widely in PHEMA-CNC(aniso) but rather locally appeared in PHEMA-CNC(iso). Any of the CNC incorporations into the PHEMA matrix improved the original thermal and mechanical properties of this amorphous polymer material. In dynamic mechanical measurements, the locking-in of the respective CNC assemblies gave rise to an increase in the glass-state modulus E' of PHEMA as well as a marked suppression of the E'-falling at temperatures higher than T(g) (≈ 110 °C) of the vinyl polymer. It was also observed for the composites that their modulus E' rerose in a range of about 150-190 °C, which was attributable to a secondary cross-linking formation between PHEMA chains mediated by the acidic CNC filler. The mechanical reinforcement effect of the CNC dispersions was ensured in a tensile test, whereby PHEMA-CNC(aniso) was found to surpass the other two composites in stiffness and strength.

Curcumin-carboxymethyl chitosan (CNC) conjugate and CNC/LHR mixed polymeric micelles as new approaches to improve the oral absorption of P-gp substrate drugs.

PubMed

Ni, Jiang; Tian, Fengchun; Dahmani, Fatima Zohra; Yang, Hui; Yue, Deren; He, Shuwang; Zhou, Jianping; Yao, Jing

2016-11-01

The low oral bioavailability of numerous drugs has been mostly attributed to the significant effect of P-gp-mediated efflux on intestinal drug transport. Herein, we developed mixed polymeric micelles (MPMs) comprised of curcumin-carboxymethyl chitosan (CNC) conjugate, as a potential inhibitor of P-gp-mediated efflux and gastrointestinal absorption enhancer, and low-molecular-weight heparin-all-trans-retinoid acid (LHR) conjugate, as loading material, with the aim to improve the oral absorption of P-gp substrate drugs. CNC conjugate was synthesized by chemical bonding of curcumin (Cur) and carboxymethyl chitosan (CMCS) taking advantage of the inhibition of intestinal P-gp-mediated secretion by Cur and the intestinal absorption enhancement by CMCS. The chemical structure of CNC conjugate was characterized by 1 H NMR with a degree of substitution of Cur of 4.52-10.20%. More importantly, CNC conjugate markedly improved the stability of Cur in physiological pH. Cyclosporine A-loaded CNC/LHR MPMs (CsA-CNC/LHR MPMs) were prepared by dialysis method, with high drug loading 25.45% and nanoscaled particle size (∼200 nm). In situ single-pass perfusion studies in rats showed that both CsA + CNC mixture and CsA-CNC/LHR MPMs achieved significantly higher K a and P eff than CsA suspension in the duodenum and jejunum segments (p <  0.01), which was comparable to verapamil coperfusion effect. Similarly, CsA + CNC mixture and CsA-CNC/LHR MPMs significantly increased the oral bioavailability of CsA as compared to CsA suspension. These results suggest that CNC conjugate might be considered as a promising gastrointestinal absorption enhancer, while CNC/LHR MPMs had the potential to improve the oral absorption of P-gp substrate drugs.

ADAM13 function is required in the 3 dimensional context of the embryo during cranial neural crest cell migration in Xenopus laevis

PubMed Central

Cousin, Hélène; Abbruzzese, Genevieve; McCusker, Catherine; Alfandari, Dominique

2012-01-01

The cranial neural crest (CNC) is a population of cells that arises from the lateral part of the developing brain, migrates ventrally and coordinates the entire craniofacial development of vertebrates. Many molecules are involved in CNC migration including the transmembrane metalloproteases ADAM13 and 19. We have previously shown that these ADAMs cleave a number of extracellular proteins and modify the transcription of a number of genes, and that both of these activities are important for cell migration. Here we show that the knock down of ADAM13 inhibits CNC migration in vivo but not in vitro, indicating that ADAM13 function is required in the 3-dimentional context of the embryo. We further show that the migration of CNC that do not express ADAM13 and ADAM19 can be rescued in vivo by co-grafting wild type CNC. Furthermore, the migration of CNC lacking ADAM13 can be rescued by mechanically separating the CNC from the surrounding ectoderm and mesoderm. Finally, we show that ADAM13 function is autonomous to CNC tissue, as the migration of morphant CNC can only be rescued by ADAM13 expression in the CNC and not the surrounding tissues. Together our results suggest that ADAM13 changes CNC interaction with the extracellular environment and that this change is necessary for their migration in vivo. PMID:22683825

Adsorption of polyethylene glycol (PEG) onto cellulose nano-crystals to improve its dispersity.

PubMed

Cheng, Dong; Wen, Yangbing; Wang, Lijuan; An, Xingye; Zhu, Xuhai; Ni, Yonghao

2015-06-05

In this work, the adsorption of polyethylene glycol (PEG) onto cellulose nano-crystals (CNC) was investigated for preparing re-dispersible dried CNC. Results showed that the re-dispersity of CNC in water can be significantly enhanced using a PEG1000 dosage of 5wt% (based on the dry weight of CNC). The elemental analysis confirmed the adsorption of PEG onto the CNC surface. Transmission electron microscopy (TEM) was used to characterize the dry powder and indicated that the irreversible agglomeration of CNC after drying was essentially eliminated based on the PEG adsorption concept. Thermo-gravimetric analysis (TGA) and X-ray diffraction (XRD) suggested that CNC crystallinity and thermal stability were not affected by the adsorption of PEG. Thus, the adsorption of PEG has great potential for producing re-dispersible powder CNC. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fabrication of cellulose nanocrystal from Carex meyeriana Kunth and its application in the adsorption of methylene blue.

PubMed

Yang, Xue; Liu, Hui; Han, Fuyi; Jiang, Shuai; Liu, Lifang; Xia, Zhaopeng

2017-11-01

Cellulose nanocrystal (CNC) was extracted from Carex meyeriana Kunth (CMK) by a combination of TEMPO oxidation and mechanical homogenization method, and used to remove methylene blue (MB) from aqueous solution. After alkali-oxygen treatment, the aqueous biphasic system (polyethylene glycol/inorganic salt) was applied to further remove lignin from CMK. The characteriazation of CNC, and the effects of H 2 O 2 dosage, CNC dosage, adsorption time, and initial MB concentration on the MB removal capacity of CNC were investigated. The results showed that the removal percentage of MB by CNC was raised with the increase of H 2 O 2 and CNC dosage. The adsorption kinetics of prepared CNC followed the pseudo-second-order model, and the adsorption isotherms fitted well to the Langmuir model with a calculated maximum adsoption capacity of 217.4mg/g, which was higher than those of CNC extracted by acid hydrolysis method, indicating CNC extracted from CMK had promising potentials in the field of MB adsorption. Copyright © 2017 Elsevier Ltd. All rights reserved.

Accelerating Industrial Adoption of Metal Additive Manufacturing Technology

NASA Astrophysics Data System (ADS)

Vartanian, Kenneth; McDonald, Tom

2016-03-01

While metal additive manufacturing (AM) technology has clear benefits, there are still factors preventing its adoption by industry. These factors include the high cost of metal AM systems, the difficulty for machinists to learn and operate metal AM machines, the long approval process for part qualification/certification, and the need for better process controls; however, the high AM system cost is the main barrier deterring adoption. In this paper, we will discuss an America Makes-funded program to reduce AM system cost by combining metal AM technology with conventional computerized numerical controlled (CNC) machine tools. Information will be provided on how an Optomec-led team retrofitted a legacy CNC vertical mill with laser engineered net shaping (LENS®—LENS is a registered trademark of Sandia National Labs) AM technology, dramatically lowering deployment cost. The upgraded system, dubbed LENS Hybrid Vertical Mill, enables metal additive and subtractive operations to be performed on the same machine tool and even on the same part. Information on the LENS Hybrid system architecture, learnings from initial system deployment and continuing development work will also be provided to help guide further development activities within the materials community.

Gelation Kinetics and Network Structure of Cellulose Nanocrystals in Aqueous Solution.

PubMed

Peddireddy, Karthik R; Capron, Isabelle; Nicolai, Taco; Benyahia, Lazhar

2016-10-10

Cellulose nanocrystals (CNC) are rod-like biosourced nanoparticles that are widely used in a range of applications. Charged CNC was obtained by acid extraction from cotton and dispersed in aqueous solution using ultrasound and characterized by light scattering. Aggregation and gelation of CNC induced by addition of NaCl was investigated by light scattering as a function of the NaCl concentration (30-70 mM), the CNC concentration (0.5-5 g/L), and the temperature (10-60 °C). Formation of fractal aggregates was observed that grow with time until they percolate and form a weak system spanning network. The aggregation rate and gel time were found to decrease very steeply with increasing NaCl concentration and more weakly with increasing CNC concentration. A decrease of the gel time was also observed with increasing temperature for T > 20 °C. The structure of the CNC networks was studied using confocal laser scanning microscopy and light scattering. The local structure of the networks was fractal and reflected that of the constituting aggregates. The gels were homogeneous on length scales larger than the correlation length, which decreased with increasing CNC concentration. The CNC gels flowed when tilted for C < 12 g/L and sedimentation was observed macroscopically for C < 4 g/L due to the collapse of the CNC network under gravity. The speed and extent of sedimentation was investigated as a function of the ionic strength and the CNC concentration. Gelled CNC could be completely redispersed by applying ultrasound.

Table-driven software architecture for a stitching system

NASA Technical Reports Server (NTRS)

Thrash, Patrick J. (Inventor); Miller, Jeffrey L. (Inventor); Pallas, Ken (Inventor); Trank, Robert C. (Inventor); Fox, Rhoda (Inventor); Korte, Mike (Inventor); Codos, Richard (Inventor); Korolev, Alexandre (Inventor); Collan, William (Inventor)

2001-01-01

Native code for a CNC stitching machine is generated by generating a geometry model of a preform; generating tool paths from the geometry model, the tool paths including stitching instructions for making stitches; and generating additional instructions indicating thickness values. The thickness values are obtained from a lookup table. When the stitching machine runs the native code, it accesses a lookup table to determine a thread tension value corresponding to the thickness value. The stitching machine accesses another lookup table to determine a thread path geometry value corresponding to the thickness value.

Remote estimation of canopy nitrogen content in winter wheat using airborne hyperspectral reflectance measurements

NASA Astrophysics Data System (ADS)

Zhou, Xianfeng; Huang, Wenjiang; Kong, Weiping; Ye, Huichun; Luo, Juhua; Chen, Pengfei

2016-11-01

Timely and accurate assessment of canopy nitrogen content (CNC) provides valuable insight into rapid and real-time nitrogen status monitoring in crops. A semi-empirical approach based on spectral index was extensively used for nitrogen content estimation. However, in many cases, due to specific vegetation types or local conditions, the applicability and robustness of established spectral indices for nitrogen retrieval were limited. The objective of this study was to investigate the optimal spectral index for winter wheat (Triticum aestivum L.) CNC estimation using Pushbroom Hyperspectral Imager (PHI) airborne hyperspectral data. Data collected from two different field experiments that were conducted during the major growth stages of winter wheat in 2002 and 2003 were used. Our results showed that a significant linear relationship existed between nitrogen and chlorophyll content at the canopy level, and it was not affected by cultivars, growing conditions and nutritional status of winter wheat. Nevertheless, it varied with growth stages. Periods around heading stage mainly worsened the relationship and CNC estimation, and CNC assessment for growth stages before and after heading could improve CNC retrieval accuracy to some extent. CNC assessment with PHI airborne hyperspectra suggested that spectral indices based on red-edge band including narrowband and broadband CIred-edge, NDVI-like and ND705 showed convincing results in CNC retrieval. NDVI-like and ND705 were sensitive to detect CNC changes less than 5 g/m2, narrowband and broadband CIred-edge were sensitive to a wide range of CNC variations. Further evaluation of CNC retrieval using field measured hyperspectra indicated that NDVI-like was robust and exhibited the highest accuracy in CNC assessment, and spectral indices (CIred-edge and CIgreen) that established on narrow or broad bands showed no obvious difference in CNC assessment. Overall, our study suggested that NDVI-like was the optimal indicator for winter wheat CNC retrieval.

Gold nanoparticles stabilized by poly(4-vinylpyridine) grafted cellulose nanocrystals as efficient and recyclable catalysts.

PubMed

Zhang, Zhen; Sèbe, Gilles; Wang, Xiaosong; Tam, Kam C

2018-02-15

pH-responsive poly(4-vinylpyridine) (P4VP) grafted cellulose nanocrystals (P4VP-g-CNC) were prepared by Surface-Initiated Atom Transfer Radical Polymerization (SI-ATRP) and subsequently used to stabilize gold nanoparticles (Au NPs) as efficient and recyclable nanocatalysts for the reduction of 4-nitrophenol (4NP). The presence of P4VP brushes on the CNC surface controlled the growth of Au NPs yielding smaller averaged diameter compared to Au NPs deposited directly on pristine CNC. The catalytic performances of pristine Au NPs, Au@CNC and Au@P4VP-g-CNC were compared by measuring the turnover frequency (TOF) for the catalytic reduction of 4NP. Compared to pristine Au NPs, the catalytic activity of Au@CNC and Au@P4VP-g-CNC were 10 and 24 times better. Moreover, the Au@P4VP-g-CNC material could be recovered via flocculation at pH>5, and the recycled nanocatalyst remained highly active. Copyright © 2017 Elsevier Ltd. All rights reserved.

Improvement of antifouling performances for modified PVDF ultrafiltration membrane with hydrophilic cellulose nanocrystal

NASA Astrophysics Data System (ADS)

Lv, Jinling; Zhang, Guoquan; Zhang, Hanmin; Zhao, Chuanqi; Yang, Fenglin

2018-05-01

Hydrophilic cellulose nanocrystal (CNC) was incorporated into hydrophobic poly(vinylidene fluoride) (PVDF) membrane via phase inversion process to improve membrane antifouling property. The effects of CNC on membrane morphology, hydrophilicity, permeability and antifouling property were investigated in-detail. Results indicated that the introduction of CNC into PVDF membrane enhanced the permeability by optimizing membrane microstructure and improving membrane hydrophilicity. A higher pure water flux of 206.9 L m-2 h-1 was achieved for CNC/PVDF membrane at 100 kPa, which was 20 times that of PVDF membrane (9.8 L m-2 h-1). In bovine serum albumin filtration measurements, the permeation flux and flux recovery ratio of CNC/PVDF membrane were increased remarkably, while the irreversible fouling-resistance of CNC/PVDF membrane decreased by 48.8%. These results indicated that the CNC/PVDF membrane possessed superior antifouling property due to the hydrophilicity of CNC that formed a hydration layer on the membrane surface to effectively reduce contaminants adsorption/deposition.

Subdivision of arthropod cap-n-collar expression domains is restricted to Mandibulata

PubMed Central

2014-01-01

Background The monophyly of Mandibulata - the division of arthropods uniting pancrustaceans and myriapods - is consistent with several morphological characters, such as the presence of sensory appendages called antennae and the eponymous biting appendage, the mandible. Functional studies have demonstrated that the patterning of the mandible requires the activity of the Hox gene Deformed and the transcription factor cap-n-collar (cnc) in at least two holometabolous insects: the fruit fly Drosophila melanogaster and the beetle Tribolium castaneum. Expression patterns of cnc from two non-holometabolous insects and a millipede have suggested conservation of the labral and mandibular domains within Mandibulata. However, the activity of cnc is unknown in crustaceans and chelicerates, precluding understanding of a complete scenario for the evolution of patterning of this appendage within arthropods. To redress these lacunae, here we investigate the gene expression of the ortholog of cnc in Parhyale hawaiensis, a malacostracan crustacean, and two chelicerates: the harvestman Phalangium opilio, and the scorpion Centruroides sculpturatus. Results In the crustacean P. hawaiensis, the segmental expression of Ph-cnc is the same as that reported previously in hexapods and myriapods, with two distinct head domains in the labrum and the mandibular segment. In contrast, Po-cnc and Cs-cnc expression is not enriched in the labrum of either chelicerate, but instead is expressed at comparable levels in all appendages. In further contrast to mandibulate orthologs, the expression domain of Po-cnc posterior to the labrum is not confined within the expression domain of Po-Dfd. Conclusions Expression data from two chelicerate outgroup taxa suggest that the signature two-domain head expression pattern of cnc evolved at the base of Mandibulata. The observation of the archetypal labral and mandibular segment domains in a crustacean exemplar supports the synapomorphic nature of mandibulate cnc expression. The broader expression of Po-cnc with respect to Po-Dfd in chelicerates further suggests that the regulation of cnc by Dfd was also acquired at the base of Mandibulata. To test this hypothesis, future studies examining panarthropod cnc evolution should investigate expression of the cnc ortholog in arthropod outgroups, such as Onychophora and Tardigrada. PMID:24405788

Nonvolatile memory behavior of nanocrystalline cellulose/graphene oxide composite films

NASA Astrophysics Data System (ADS)

Valentini, L.; Cardinali, M.; Fortunati, E.; Kenny, J. M.

2014-10-01

With the continuous advance of modern electronics, the demand for nonvolatile memory cells rapidly grows. In order to develop post-silicon electronic devices, it is necessary to find innovative solutions to the eco-sustainability problem of materials for nonvolatile memory cells. In this work, we realized a resistive memory device based on graphene oxide (GO) and GO/cellulose nanocrystals (CNC) thin films. Aqueous solutions of GO and GO with CNC have been prepared and drop cast between two metal electrodes. Such thin-film based devices showed a transition between low and high conductivity states upon the forward and backward sweeping of an external electric field. This reversible current density transition behavior demonstrates a typical memory characteristic. The obtained results open an easy route for electronic information storage based on the integration of nanocrystalline cellulose onto graphene based devices.

Hygroscopic Swelling Determination of Cellulose Nanocrystal (CNC) Films by Polarized Light Microscopy Digital Image Correlation.

PubMed

Shrestha, Shikha; Diaz, Jairo A; Ghanbari, Siavash; Youngblood, Jeffrey P

2017-05-08

The coefficient of hygroscopic swelling (CHS) of self-organized and shear-oriented cellulose nanocrystal (CNC) films was determined by capturing hygroscopic strains produced as result of isothermal water vapor intake in equilibrium. Contrast enhanced microscopy digital image correlation enabled the characterization of dimensional changes induced by the hygroscopic swelling of the films. The distinct microstructure and birefringence of CNC films served in exploring the in-plane hygroscopic swelling at relative humidity values ranging from 0% to 97%. Water vapor intake in CNC films was measured using dynamic vapor sorption (DVS) at constant temperature. The obtained experimental moisture sorption and kinetic profiles were analyzed by fitting with Guggenheim, Anderson, and deBoer (GAB) and Parallel Exponential Kinetics (PEK) models, respectively. Self-organized CNC films showed isotropic swelling, CHS ∼0.040 %strain/%C. By contrast, shear-oriented CNC films exhibited an anisotropic swelling, resulting in CHS ∼0.02 and ∼0.30 %strain/%C, parallel and perpendicular to CNC alignment, respectively. Finite element analysis (FEA) further predicted moisture diffusion as the predominant mechanism for swelling of CNC films.

Highly Modified Cellulose Nanocrystals and Formation of Epoxy-CNC Nanocomposites.

PubMed

Abraham, Eldho; Kam, Doron; Nevo, Yuval; Slattegard, Rikard; Rivkin, Amit; Lapidot, Shaul; Shoseyov, Oded

2016-10-05

This work presents an environmentally friendly, iodine-catalysed chemical modification method to generate highly hydrophobic, optically active cellulose nanocrystals (CNC). The high degree of ester substitution (DS=2.18), hydrophobicity, crystalline behaviour and optical activity of the generated acetylated CNC (Ac-CNC) were quantified by TEM, FTIR, solid 13C NMR, contact angle, XRD and POM analyses. Ac-CNC possessing substantial enhancement in thermal stability (16.8%) and forms thin films with interlayer distance of 50-150 nm, presenting cavities suitable for entrapping nano and micro particles. Generated Ac-CNC proved as an effective reinforcing agent in hydrophobic polymer matrices for fabricating high performance nanocomposites. When integrated at a very low weight percentage (0.5%) in an epoxy matrix, Ac-CNC provided for a 73% increase in tensile strength and a 98% increase in modulus, demonstrating its remarkable reinforcing potential and effective stress transfer behaviour. The method of modification and the unique properties of the modified CNC (hydrophobicity, crystallinity, reinforcing ability and optical activity) render them a novel bionanomaterial for a range of multipurpose applications.

Crystallization, structural relaxation and thermal degradation in Poly(L-lactide)/cellulose nanocrystal renewable nanocomposites.

PubMed

Lizundia, E; Vilas, J L; León, L M

2015-06-05

In this work, crystallization, structural relaxation and thermal degradation kinetics of neat Poly(L-lactide) (PLLA) and its nanocomposites with cellulose nanocrystals (CNC) and CNC-grafted-PLLA (CNC-g-PLLA) have been studied. Although crystallinity degree of nanocomposites remains similar to that of neat homopolymer, results reveal an increase on the crystallization rate by 1.7-5 times boosted by CNC, which act as nucleating agents during the crystallization process. In addition, structural relaxation kinetics of PLLA chains has been drastically reduced by 53% and 27% with the addition of neat and grafted CNC, respectively. The thermal degradation activation energy (E) has been determined from thermogravimetric analysis in the light of Kissinger's and Ozawa-Flynn-Wall theoretical models. Results reveal a reduction on the thermal stability when in presence of CNC-g-PLLA, while raw CNC slightly increases the thermal stability of PLLA. Fourier transform infrared spectroscopy and energy dispersive X-ray spectroscopy results confirm that the presence of residual catalyst in CNC-g-PLLA plays a pivotal role in the thermal degradation behavior of nanocomposites. Copyright © 2015 Elsevier Ltd. All rights reserved.

Generation of 1:1 Carbamazepine:Nicotinamide cocrystals by spray drying.

PubMed

Patil, Shashank P; Modi, Sameer R; Bansal, Arvind K

2014-10-01

The present study investigates the potential of spray drying as a technique for generation of pharmaceutical cocrystals. Carbamazepine-Nicotinamide cocrystal (CNC) was chosen as model cocrystal system for this study. Firstly, CNC was generated using liquid assisted grinding and used for generation of phase solubility diagram (PSD) and ternary phase diagram (TPD). Both PSD and TPD were carefully evaluated for phase behavior of CNC when equilibrated with solvent. The undersaturated region with respect to CNC, as depicted by TPD, was selected as target region to initiate cocrystallization experiments. Various points in this region, representative of different compositions of Carbamazepine, Nicotinamide and CNC, were selected and spray drying was carried out. The spray dried product was characterized for solid state properties and was compared with CNC generated by liquid assisted grinding. Spray drying successfully generated CNC of similar quality as those generated by liquid assisted grinding. Moreover, there was no significant impact of process variables on formation of CNC. Spray drying, owing to its simplicity and industrial scalability, can be a promising method for large scale cocrystal generation. Copyright © 2014 Elsevier B.V. All rights reserved.

FGF8 signaling sustains progenitor status and multipotency of cranial neural crest-derived mesenchymal cells in vivo and in vitro

PubMed Central

Shao, Meiying; Liu, Chao; Song, Yingnan; Ye, Wenduo; He, Wei; Yuan, Guohua; Gu, Shuping; Lin, Congxin; Ma, Liang; Zhang, Yanding; Tian, Weidong; Hu, Tao; Chen, YiPing

2015-01-01

The cranial neural crest (CNC) cells play a vital role in craniofacial development and regeneration. They are multi-potent progenitors, being able to differentiate into various types of tissues. Both pre-migratory and post-migratory CNC cells are plastic, taking on diverse fates by responding to different inductive signals. However, what sustains the multipotency of CNC cells and derivatives remains largely unknown. In this study, we present evidence that FGF8 signaling is able to sustain progenitor status and multipotency of CNC-derived mesenchymal cells both in vivo and in vitro. We show that augmented FGF8 signaling in pre-migratory CNC cells prevents cell differentiation and organogenesis in the craniofacial region by maintaining their progenitor status. CNC-derived mesenchymal cells with Fgf8 overexpression or control cells in the presence of exogenous FGF8 exhibit prolonged survival, proliferation, and multi-potent differentiation capability in cell cultures. Remarkably, exogenous FGF8 also sustains the capability of CNC-derived mesenchymal cells to participate in organogenesis such as odontogenesis. Furthermore, FGF8-mediated signaling strongly promotes adipogenesis but inhibits osteogenesis of CNC-derived mesenchymal cells in vitro. Our results reveal a specific role for FGF8 in the maintenance of progenitor status and in fate determination of CNC cells, implicating a potential application in expansion and fate manipulation of CNC-derived cells in stem cell-based craniofacial regeneration. PMID:26243590

Thermal degradation kinetics of polylactic acid/acid fabricated cellulose nanocrystal based bionanocomposites.

PubMed

Monika; Dhar, Prodyut; Katiyar, Vimal

2017-11-01

Cellulose nanocrystals (CNC) are fabricated from filter paper (as cellulosic source) by acid hydrolysis using different acids such as sulphuric (H 2 SO 4 ), phosphoric (H 3 PO 4 ), hydrochloric (HCl) and nitric (HNO 3 ) acid. The resulting acid derived CNC are melt mixed with Polylactic acid (PLA) using extruder at 180°C. Thermogravimetric (TGA) result shows that increase in 10% and 50% weight loss (T 10 , T 50 ) temperature for PLA-CNC film fabricated with HNO 3 , H 3 PO 4 and HCl derived CNC have improved thermal stability in comparison to H 2 SO 4 -CNC. Nonisothermal kinetic studies are carried out with modified-Coats-Redfern (C-R), Ozawa-Flynn-Wall (OFW) and Kissinger method to predict the kinetic and thermodynamic parameters. Subsequently prediction of these parameter leads to the proposal of thermal induced degradation mechanism of nanocomposites using Criado method. The distribution of E a calculated from OFW model are (PLA-H 3 PO 4 -CNC: 125-139 kJmol -1 ), (PLA-HNO 3 -CNC: 126-145 kJmol -1 ), (PLA-H 2 SO 4 -CNC: 102-123 kJmol -1 ) and (PLA-HCl-CNC: 140-182 kJmol -1 ). This difference among E a for the decomposition of PLA-CNC bionanocomposite is probably due to various acids used in this study. The E a calculated by these two methods are found in consonance with that observed from Kissinger method. Further, hyphenated TG-Fourier transform infrared spectroscopy (FTIR) result shows that gaseous products such as CO 2 , CO, lactide, aldehydes and other compounds are given off during the thermal degradation of PLA-CNC nanocomposite. Copyright © 2017 Elsevier B.V. All rights reserved.

Sono-chemical synthesis of cellulose nanocrystals from wood sawdust using Acid hydrolysis.

PubMed

Shaheen, Th I; Emam, Hossam E

2018-02-01

Cellulose nanocrystal (CNC) is a unique material obtained from naturally occurring cellulose fibers. Owing to their mechanical, optical, chemical, and rheological properties, CNC gained significant interest. Herein, we investigate the potential of commercially non-recyclable wood waste, in particular, sawdust as a new resource for CNC. Isolation of CNC from sawdust was conducted as per acid hydrolysis which induced by ultrasonication technique. Thus, sawdust after being alkali delignified prior sodium chlorite bleaching, was subjected to sulfuric acid with concentration of 65% (w/w) at 60 ° C for 60min. After complete reaction, CNC were collected by centrifugation followed by dialyzing against water and finally dried via using lyophilization technique. The CNC yield attained values of 15% from purified sawdust. Acid hydrolysis mechanism exactly referred that, the amorphous regions along with thinner as well as shorter crystallites spreaded throughout the cellulose structure are digested by the acid leaving CNC suspension. The latter was freeze-dried to produce CNC powder. A thorough investigation pertaining to nanostructural characteristics of CNC was performed. These characteristics were monitored using TEM, SEM, AFM, XRD and FTIR spectra for following the changes in functionality. Based on the results obtained, the combination of sonication and chemical treatment was great effective in extraction of CNC with the average dimensions (diameter×length) of 35.2±7.4nm×238.7±81.2nm as confirmed from TEM. Whilst, the XRD study confirmed the crystal structure of CNC is obeyed cellulose type I with crystallinity index ∼90%. Cellulose nanocrystals are nominated as the best candidate within the range studied in the area of reinforcement by virtue of their salient textural features. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of post-treatments and concentration of cotton linter cellulose nanocrystals on the properties of agar-based nanocomposite films.

PubMed

Oun, Ahmed A; Rhim, Jong-Whan

2015-12-10

Cellulose nanocrystals (CNCs) were prepared by acid hydrolysis of cotton linter pulp fibers and three different purification methods, i.e., without post purification (CNC1), dialyzed against distilled water (CNC2), and neutralized with NaOH (CNC3), and their effect on film properties was evaluated by preparation of agar/CNCs composite films. All the CNCs were rod in shape with diameter of 15-50 nm and length of 210-480 nm. FTIR result indicated that there was no distinctive differences in the chemical structure between CNCs and cotton linter cellulose fiber. No significant relationship was observed between the sulfate content and crystallinity index of CNCs. The CNC3 showed higher thermal stability than the other type of CNCs due to the less adverse effect on the thermal stability of sulfate groups induced by the neutralization with NaOH. The tensile strength (TS) of agar film increased by 15% with incorporation of 5 wt% of CNC3, on the contrary, it decreased by 10% and 15% with incorporation of CNC1 and CNC2, respectively. Other performance properties of agar/CNCs composite films such as optical and water vapor barrier properties showed that the CNC3 was more effective filler than the other CNCs. In the range of concentration of CNC3 tested (1-10 wt%), inclusion of 5 wt% of CNC3 was the maximum concentration for improving or maintaining film properties of the composite films. The neutralization of acid hydrolyzed cellulose using NaOH was simple and convenient for the preparation of CNC and bionanocomposite films. Copyright © 2015 Elsevier Ltd. All rights reserved.

Surface modification and antimicrobial properties of cellulose nanocrystals

NASA Astrophysics Data System (ADS)

Bespalova, Yulia A.

Surface modification of cellulose nanocrystals (CNC) was performed by acetylation and subsequent reaction with various tertiary amines with different lengths of alkyl groups. Chloroacetic anhydride (95%) was used for acetylation. The acetylation of CNC was confirmed using IR spectroscopy. The bands associated with C=0 stretching (1740 cm-1) and C-Cl stretching (793 cm -1) was present in the acetylated CNC but they were absent in the neat CNC. It has been suggested that the primary hydroxyl groups of CNC are substituted by chloro acetyl groups during acetylation reaction. Subsequent reaction of chloro acetylated CNC with N, N - Dimethyl ethylamine, N, N - Dimethyl hexylamine, N, N - Dimethyl dodecylamine, N, N - Dimethyl hexadecylamine and N, N - Dimethyl decylamine formed quaternary ammonium salts. These quaternary ammonium salts were characterized by FTIR and solid state13C NMR spectroscopy. FTIR spectra of five types of quaternary ammonium salts of CNC are similar and they showed infrared bands at 2905 -1 and 2850 cm-1, attributed to symmetrical and unsymmetrical C-H stretching vibration. The absence of C-Cl band at 793 cm-1 proves that quaternary salt formation was successful. The 13C NMR spectrum of quaternary ammonium modified CNC with N, N - Dimethyl dodecylamine shows several additional resonances ranging from 14.5 ppm to 58.0 ppm when compared to 13C NMR spectrum of pure CNC. This evidence proves that long alkyl chains have been added to the pure CNC. The disc diffusion method confirmed that quaternary ammonium modified CNCs with a chain longer than ten carbons are effective antimicrobial agents against Staphylococcus aureus and E. coli bacteria. Pure CNC and quaternary ammonium modified CNCs with an alkyl chain length of ten or less were not able to inhibit bacteria growth.

Introducing cellulose nanocrystals in sheet molding compounds (SMC)

Treesearch

Amir Asadi; Mark Miller; Sanzida Sultana; Robert J. Moon; Kyriaki Kalaitzidou

2016-01-01

The mechanical properties of short glass fiber/epoxy composites containing cellulose nanocrystals (CNC) made using sheet molding compound (SMC) manufacturing method as well as the rheological and thermomechanical properties of the CNC-epoxy composites were investigated as a function of the CNC content. CNC up to 1.4 wt% were dispersed in the epoxy to produce the resin...

Physicochemical characterization of cellulose nanocrystal and nanoporous self-assembled CNC membrane derived from Ceiba pentandra.

PubMed

Mohamed, Mohamad Azuwa; W Salleh, W N; Jaafar, Juhana; Ismail, A F; Abd Mutalib, Muhazri; Mohamad, Abu Bakar; M Zain, M F; Awang, Nor Asikin; Mohd Hir, Zul Adlan

2017-02-10

This research involves the rare utilisation of the kapok fibre (Ceiba pentandra) as a raw material for the fabrication of cellulose nanocrystal (CNC) and self-assembled CNC membranes. The isolation of CNC from Ceiba pentandra began with the extraction of cellulose via the chemical alkali extraction by using 5wt% NaOH, followed by the typical acidified bleaching method and, finally, the CNC production through acid hydrolysis with 60wt% H 2 SO 4 at the optimum time of 60min. The prepared CNC was then employed for the preparation of self-assembled membrane through the water suspension casting evaporation technique. The obtained CNC membrane was characterised in terms of its composition, crystallinity, thermal stability, as well as, structural and morphological features with the use of several techniques including FTIR, XRD, AFM, TEM, FESEM, and TGA. The FESEM and AFM analyses had illustrated the achievement of a self-assembled CNC membrane with a smooth surface and a well-distributed nano-porous structure, with the porosity of 52.82±7.79%. In addition, the findings proved that the self-assembled CNC membrane displayed good adsorption capability indicated by the recorded efficiency of 79% and 85% for 10mg/L and 5mg/L of methylene blue in an aqueous solution, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of different carboxylic acids in cyclodextrin functionalization of cellulose nanocrystals for prolonged release of carvacrol.

PubMed

Castro, D O; Tabary, N; Martel, B; Gandini, A; Belgacem, N; Bras, J

2016-12-01

Current investigations deal with new surface functionalization strategy of nanocrystalline cellulose-based substrates to impart active molecule release properties. In this study, cellulose nanocrystals (CNC) were surface-functionalized with β-cyclodextrin (β-CD) using succinic acid (SA) and fumaric acid (FA) as bridging agents. The main objective of this surface modification performed only in aqueous media was to obtain new active materials able to release antibacterial molecules over a prolonged period of time. The reactions were conducted by immersing the CNC film into a solution composed of β-CD, SA and FA, leading to CNC grafting. The materials were characterized by infrared spectroscopy (FT-IR), Quartz crystal microbalance-dissipation (QCM-D), AFM and phenolphthalein (PhP) was used to determine the efficiency of CNC grafting with β-CD. The results indicated that β-CD was successfully attached to the CNC backbone through the formation of ester bonds. Furthermore, carvacrol was entrapped by the attached β-CD and a prolonged release was confirmed. In particular, CNC grafted to β-CD in the presence of FA was selected as the best solution. The antibacterial activity and the controlled release were studied for this sample. Considerably longer bacterial activity against B. subtilis was observed for CNC grafted to β-CD compared to CNC and CNC-FA, confirming the promising impact of the present strategy. Copyright © 2016 Elsevier B.V. All rights reserved.

Visualization of the Drosophila dKeap1-CncC interaction on chromatin illumines cooperative, xenobiotic-specific gene activation

PubMed Central

Deng, Huai; Kerppola, Tom K.

2014-01-01

Interactions among transcription factors control their physiological functions by regulating their binding specificities and transcriptional activities. We implement a strategy to visualize directly the genomic loci that are bound by multi-protein complexes in single cells in Drosophila. This method is based on bimolecular fluorescence complementation (BiFC) analysis of protein interactions on polytene chromosomes. Drosophila Keap1 (dKeap1)-CncC complexes localized to the nucleus and bound chromatin loci that were not bound preferentially by dKeap1 or CncC when they were expressed separately. dKeap1 and CncC binding at these loci was enhanced by phenobarbital, but not by tert-butylhydroquinone (tBHQ) or paraquat. Endogenous dKeap1 and CncC activated transcription of the Jheh (Jheh1, Jheh2, Jheh3) and dKeap1 genes at these loci, whereas CncC alone activated other xenobiotic response genes. Ectopic dKeap1 expression increased CncC binding at the Jheh and dKeap1 gene loci and activated their transcription, whereas dKeap1 inhibited CncC binding at other xenobiotic response gene loci and suppressed their transcription. The combinatorial chromatin-binding specificities and transcriptional activities of dKeap1-CncC complexes mediated the selective activation of different sets of genes by different xenobiotic compounds, in part through feed-forward activation of dKeap1 transcription. PMID:25063457

Nonvolatile memory behavior of nanocrystalline cellulose/graphene oxide composite films

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

Valentini, L., E-mail: luca.valentini@unipg.it; Cardinali, M.; Fortunati, E.

2014-10-13

With the continuous advance of modern electronics, the demand for nonvolatile memory cells rapidly grows. In order to develop post-silicon electronic devices, it is necessary to find innovative solutions to the eco-sustainability problem of materials for nonvolatile memory cells. In this work, we realized a resistive memory device based on graphene oxide (GO) and GO/cellulose nanocrystals (CNC) thin films. Aqueous solutions of GO and GO with CNC have been prepared and drop cast between two metal electrodes. Such thin-film based devices showed a transition between low and high conductivity states upon the forward and backward sweeping of an external electricmore » field. This reversible current density transition behavior demonstrates a typical memory characteristic. The obtained results open an easy route for electronic information storage based on the integration of nanocrystalline cellulose onto graphene based devices.« less

Preparation of CNC-dispersed Fe3O4 nanoparticles and their application in conductive paper.

PubMed

Liu, Kai; Nasrallah, Joseph; Chen, Lihui; Huang, Liulian; Ni, Yonghao

2015-08-01

Well-dispersed Fe3O4 nanoparticles (NPs) were synthesized by a co-precipitation method in the presence of cellulose nano-crystals (CNC) as the template. The thus prepared Fe3O4 NPs were then used as a coating agent for the preparation of conductive paper. Fourier transform infrared spectroscopy (FTIR) results revealed that the Fe3O4 NPs were immobilized on the CNC through interactions between the hydroxyl groups of CNC and Fe3O4. Scanning transmission electron microscopy (STEM) images showed that the Fe3O4 NPs prepared in the presence of CNC can be dispersed in the CNC network, while the Fe3O4 NPs prepared in the absence of CNC tended to aggregate in aqueous solutions. The conductivity of the Fe3O4 NPs coated paper can reach to 0.0269 S/m at the coating amount of 14.75 g/m(2) Fe3O4/CNC nanocomposites. Therefore, the thus obtained coated paper can be potentially used as anti-static packaging material in the packaging field. Copyright © 2015 Elsevier Ltd. All rights reserved.

Polyurethane nanocomposites incorporating biobased polyols and reinforced with a low fraction of cellulose nanocrystals.

PubMed

Kong, Xiaohua; Zhao, Liyan; Curtis, Jonathan M

2016-11-05

High solids content polyurethane (PU) nanocomposites with enhanced thermal and mechanical properties were produced by incorporating of low fractions of cellulose nanocrystals (CNC) in a solvent-free process. This involved the use of a simple procedure to produce well dispersed and stable suspensions of CNC in biobased polyols, which were then used to produce PU-CNC nanocomposites. Transmission electron microscopy revealed that individual CNC particles were dispersed homogenously within the PU matrix. FTIR results suggested that CNC particles are covalently bonded to the PU molecular chains during polymerization. The thermal mechanical properties of the nanocomposites are significantly improved over pure PU as indicated by differential scanning calorimetry and dynamic mechanical analysis. Compared to pure PU, the PU nanocomposites made with the addition of only 0.5% of CNC had glass transition temperatures that were 6°C higher, their Young's moduli were about 10% higher and their abrasion resistance was higher by about 25%. The optimal composition contains only 0.5% CNC (w/w) which indicates that there is good potential for utilization of low levels of CNC for reinforcement of PU composites made using biobased polyols. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preparation of hybrid nano biocomposite κ-carrageenan/cellulose nanocrystal/nanoclay

NASA Astrophysics Data System (ADS)

Zakuwan, Siti Zarina; Ahmad, Ishak; Ramli, Nazaruddin

2013-11-01

Biodegradable composites film based on κ-carrageenan and nano particles as filler was prepared to study the mechanical strength of carrageenan composites. Solution casting technique was used to prepare_this biocomposite. Preparation of composite film and nano filler involve two stages, preparation of cellulose nanocrystals (CNC) from kenaf with alkali treatment, bleaching, and hydrolysis followed by the preparation of two types of nano composite. Tensile test was carried on the composite film based on κ-carrageenan with the variation percentage of CNC and nano clay to obtain the optimum CNC and nano clay loading. After that hybrid nano-biocomposite film based on κ-carrageenan with the variation percentage of CNC/nano clay (OMMT) according to optimum value of composite carrageenan/CNC and composite carrageenan/nano clay film was prepared. The effect of nano filler on the mechanical properties of carrageenan films was examined. κ-carrageenan biocomposite increased with the optimum at 4% CNC and nano clay composition. Additional improvement of tensile strength with hybridization of CNC and nanoclay indicated better mechanical properties.

A comparative study on cellulose nanocrystals extracted from bleached cotton and flax and used for casting films with glycerol and sorbitol plasticisers.

PubMed

Csiszár, Emilia; Nagy, Sebestyén

2017-10-15

Cellulose nanocrystals (CNCs) were released from bleached cotton and flax by a sulphuric acid hydrolysis with about 40 and 34% yield, respectively. The rod-like cotton-CNC particles were slightly longer and wider and had a less pronounced aggregation ability in aqueous suspension than the flax-CNC ones. Films were cast from the CNC suspensions with sorbitol and glycerol plasticisers. The concept behind this research was to explore how the plasticisers - with similar structure but different molecular weight - and their concentrations affect the perceptible and measured properties of CNC films. Results revealed that the type of plasticiser determined the morphology and the optical and tensile properties of films. The best quality CNC film with an averaged thickness of 50μm was obtained with 20% sorbitol from cotton-CNC. It was proved that behaviour of sorbitol and glycerol plasticisers in CNC films was very similar to that reported previously for starch films. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tunable organization of cellulose nanocrystals for controlled thermal and optical response

NASA Astrophysics Data System (ADS)

Diaz A., Jairo A.

The biorenewable nature of cellulose nanocrystals (CNCs) has opened up new opportunities for cost-effective, sustainable materials design. By taking advantage of their distinctive structural properties and self-assembly, promising applications have started to nurture the fields of flexible electronics, biomaterials, and nanocomposites. CNCs exhibit two fundamental characteristics: rod-like morphology (5-20 nm wide, 50-500 nm long), and lyotropic behavior (i.e., liquid crystalline mesophases formed in solvents), which offer unique opportunities for structural control and fine tuning of thermal and optical properties based on a proper understanding of their individual behavior and interactions at different length scales. In the present work, we attempt to provide an integral description of the influence of single crystals in the thermal and optical response exhibited by nanostructured films. Our approach involved the connection of experimental evidence with predictions of molecular dynamics (MD) simulations. In order to assess the effect of CNC orientation in the bulk response, we produced cellulose nanostructured films under two different mechanisms, namely, self-organization and shear orientation. Self-organized nanostructured films exhibited the typical iridescent optical reflection generated by chiral nematic organization. Shear oriented films disrupted the cholesteric organization, generating highly aligned structures with high optical transparency. The resultant CNC organization present in all nanostructured films was estimated by a second order statistical orientational distribution based on two- dimensional XRD signals. A new method to determine the coefficient of thermal expansion (CTE) in a contact-free fashion was developed to properly characterize the thermal expansion of thin soft films by excluding other thermally activated phenomena. The method can be readily extended to other soft materials to accurately measure thermal strains in a non-destructive way. By evaluating the magnitude of film CTEs relative to those of individual CNC crystals, we highlighted the significant role played by crystalline interfaces. Likewise, after measuring the thermal conductivity of a single crystal and CNC films having multiple organizations, the interfacial thermal resistance arose as a governing factor for heat transport. We will offer further insights into the intricate connection of thermal and optical properties towards a future efficient manufacture and optimal CNC based-materials design.

Carney complex (CNC).

PubMed

Bertherat, Jérôme

2006-06-06

The Carney complex (CNC) is a dominantly inherited syndrome characterized by spotty skin pigmentation, endocrine overactivity and myxomas. Skin pigmentation anomalies include lentigines and blue naevi. The most common endocrine gland manifestations are acromegaly, thyroid and testicular tumors, and adrenocorticotropic hormone (ACTH)-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD). PPNAD, a rare cause of Cushing's syndrome, is due to primary bilateral adrenal defect that can be also observed in some patients without other CNC manifestations or familial history of the disease. Myxomas can be observed in the heart, skin and breast. Cardiac myxomas can develop in any cardiac chamber and may be multiple. One of the putative CNC genes located on 17q22-24, (PRKAR1A), has been identified to encode the regulatory subunit (R1A) of protein kinase A. Heterozygous inactivating mutations of PRKAR1A were reported initially in 45 to 65% of CNC index cases, and may be present in about 80% of the CNC families presenting mainly with Cushing's syndrome. PRKAR1A is a key component of the cAMP signaling pathway that has been implicated in endocrine tumorigenesis and could, at least partly, function as a tumor suppressor gene. Genetic analysis should be proposed to all CNC index cases. Patients with CNC or with a genetic predisposition to CNC should have regular screening for manifestations of the disease. Clinical work-up for all the manifestations of CNC should be performed at least once a year in all patients and should start in infancy. Cardiac myxomas require surgical removal. Treatment of the other manifestations of CNC should be discussed and may include follow-up, surgery, or medical treatment depending on the location of the tumor, its size, the existence of clinical signs of tumor mass or hormonal excess, and the suspicion of malignancy. Bilateral adrenalectomy is the most common treatment for Cushing's syndrome due to PPNAD.

E-cadherin is required for cranial neural crest migration in Xenopus laevis.

PubMed

Huang, Chaolie; Kratzer, Marie-Claire; Wedlich, Doris; Kashef, Jubin

2016-03-15

The cranial neural crest (CNC) is a highly motile and multipotent embryonic cell population, which migrates directionally on defined routes throughout the embryo, contributing to facial structures including cartilage, bone and ganglia. Cadherin-mediated cell-cell adhesion is known to play a crucial role in the directional migration of CNC cells. However, migrating CNC co-express different cadherin subtypes, and their individual roles have yet to be fully explored. In previous studies, the expression of individual cadherin subtypes has been analysed using different methods with varying sensitivities, preventing the direct comparison of expression levels. Here, we provide the first comprehensive and comparative analysis of the expression of six cadherin superfamily members during different phases of CNC cell migration in Xenopus. By applying a quantitative RT-qPCR approach, we can determine the copy number and abundance of each expressed cadherin through different phases of CNC migration. Using this approach, we show for the first time expression of E-cadherin and XB/C-cadherin in CNC cells, adding them as two new members of cadherins co-expressed during CNC migration. Cadherin co-expression during CNC migration in Xenopus, in particular the constant expression of E-cadherin, contradicts the classical epithelial-mesenchymal transition (EMT) model postulating a switch in cadherin expression. Loss-of-function experiments further show that E-cadherin is required for proper CNC cell migration in vivo and also for cell protrusion formation in vitro. Knockdown of E-cadherin is not rescued by co-injection of other classical cadherins, pointing to a specific function of E-cadherin in mediating CNC cell migration. Finally, through reconstitution experiments with different E-cadherin deletion mutants in E-cadherin morphant embryos, we demonstrate that the extracellular domain, but not the cytoplasmic domain, of E-cadherin is sufficient to rescue CNC cell migration in vivo. Copyright © 2016 Elsevier Inc. All rights reserved.

Carney complex (CNC)

PubMed Central

Bertherat, Jérôme

2006-01-01

The Carney complex (CNC) is a dominantly inherited syndrome characterized by spotty skin pigmentation, endocrine overactivity and myxomas. Skin pigmentation anomalies include lentigines and blue naevi. The most common endocrine gland manifestations are acromegaly, thyroid and testicular tumors, and adrenocorticotropic hormone (ACTH)-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD). PPNAD, a rare cause of Cushing's syndrome, is due to primary bilateral adrenal defect that can be also observed in some patients without other CNC manifestations or familial history of the disease. Myxomas can be observed in the heart, skin and breast. Cardiac myxomas can develop in any cardiac chamber and may be multiple. One of the putative CNC genes located on 17q22-24, (PRKAR1A), has been identified to encode the regulatory subunit (R1A) of protein kinase A. Heterozygous inactivating mutations of PRKAR1A were reported initially in 45 to 65 % of CNC index cases, and may be present in about 80 % of the CNC families presenting mainly with Cushing's syndrome. PRKAR1A is a key component of the cAMP signaling pathway that has been implicated in endocrine tumorigenesis and could, at least partly, function as a tumor suppressor gene. Genetic analysis should be proposed to all CNC index cases. Patients with CNC or with a genetic predisposition to CNC should have regular screening for manifestations of the disease. Clinical work-up for all the manifestations of CNC should be performed at least once a year in all patients and should start in infancy. Cardiac myxomas require surgical removal. Treatment of the other manifestations of CNC should be discussed and may include follow-up, surgery, or medical treatment depending on the location of the tumor, its size, the existence of clinical signs of tumor mass or hormonal excess, and the suspicion of malignancy. Bilateral adrenalectomy is the most common treatment for Cushing's syndrome due to PPNAD. PMID:16756677

Facile one-pot synthesis of cellulose nanocrystal-supported hollow CuFe2O4 nanoparticles as efficient catalyst for 4-nitrophenol reduction

NASA Astrophysics Data System (ADS)

Zhang, Sufeng; Zhao, Dongyan; Hou, Chen; Liang, Chen; Li, Hao

2018-06-01

A facile and efficient one-pot method for the synthesis of well-dispersed hollow CuFe2O4 nanoparticles (H-CuFe2O4 NPs) in the presence of cellulose nanocrystals (CNC) as the support was described. Based on the one-pot solvothermal condition control, magnetic H-CuFe2O4 NPs were in-situ grown on the CNC surface uniformly. TEM images indicated good dispersity of H-CuFe2O4 NPs with uniform size of 300 nm. The catalytic activity of H-CuFe2O4/CNC was tested in the catalytic reduction of 4-nitrophenol (4-NP) in aqueous solution. Compared with most CNC-based ferrite catalysts, H-CuFe2O4/CNC catalyst exhibited an excellent catalytic activity toward the reduction of 4-NP. The catalytic performance of H-CuFe2O4/CNC catalyst was remarkably enhanced with the rate constant of 3.24 s-1 g-1, which was higher than H-CuFe2O4 NPs (0.50 s-1 g-1). The high catalytic activity was attributed to the introduction of CNC and the special hollow mesostructure of H-CuFe2O4 NPs. In addition, the H-CuFe2O4/CNC catalyst promised good conversion efficiency without significant decrease even after 10 cycles, confirming relatively high stability. Because of its environmental sustainability and magnetic separability, H-CuFe2O4/CNC catalyst was shown to indicate that the ferrite nanoparticles supported on CNC were acted as a promising catalyst and exhibited potential applications in numerous ferrite based catalytic reactions.

Cap 'n' collar C regulates genes responsible for imidacloprid resistance in the Colorado potato beetle, Leptinotarsa decemlineata.

PubMed

Gaddelapati, Sharath Chandra; Kalsi, Megha; Roy, Amit; Palli, Subba Reddy

2018-08-01

The Colorado potato beetle (CPB), Leptinotarsa decemlineata developed resistance to imidacloprid after exposure to this insecticide for multiple generations. Our previous studies showed that xenobiotic transcription factor, cap 'n' collar isoform C (CncC) regulates the expression of multiple cytochrome P450 genes, which play essential roles in resistance to plant allelochemicals and insecticides. In this study, we sought to obtain a comprehensive picture of the genes regulated by CncC in imidacloprid-resistant CPB. We performed sequencing of RNA isolated from imidacloprid-resistant CPB treated with dsRNA targeting CncC or gene coding for green fluorescent protein (control). Comparative transcriptome analysis showed that CncC regulated the expression of 1798 genes, out of which 1499 genes were downregulated in CncC knockdown beetles. Interestingly, expression of 79% of imidacloprid induced P450 genes requires CncC. We performed quantitative real-time PCR to verify the reduction in the expression of 20 genes including those coding for detoxification enzymes (P450s, glutathione S-transferases, and esterases) and ABC transporters. The genes coding for ABC transporters are induced in insecticide resistant CPB and require CncC for their expression. Knockdown of genes coding for ABC transporters simultaneously or individually caused an increase in imidacloprid-induced mortality in resistant beetles confirming their contribution to insecticide resistance. These studies identified CncC as a transcription factor involved in regulation of genes responsible for imidacloprid resistance. Small molecule inhibitors of CncC or suppression of CncC by RNAi could provide effective synergists for pest control or management of insecticide resistance. Copyright © 2018 Elsevier Ltd. All rights reserved.

The effect of cellulose nanocrystal (CNC) from rattan biomass as filler and citric acid as co-plasticizer on tensile properties of sago starch biocomposite

NASA Astrophysics Data System (ADS)

Nasution, Halimatuddahliana; Harahap, Hamidah; Afandy, Yayang; Fath, M. Thoriq Al

2017-11-01

Biocomposite containing cellulose nanocrystals (CNC) from rattan biomass as fillers and citric acid as co-plasticizer. Rattan biomass is a fiber waste from processing industry of rattan which contains 37.6% cellulose. Isolation of alpha cellulose from rattan biomass was prepared by using three stages: delignification, alkalization, and bleaching. It was delignificated with 3.5% HNO3 and NaNO2, precipitated with 17.5% NaOH, bleaching process with 10% H2O2. The preparation of CNC includes acid hydrolysis using 45% H2SO4 and followed by mechanical processes of ultrasonication, centrifugation, and filtration with a dialysis membrane. Biocomposite was prepared using a solution casting method, which includes 1-4 wt % CNC as fillers, 10-40 wt% citric acid as co-plasticizer and 30 wt% glycerol as plasticizer. The results of TGA, SEM and XRD characteristic of CNC show that CNC has low residue mass, rod like and network like shape with crystallinity index 84.46%. Biocomposite characteristic consists of SEM, tensile strength and elongation at break. The resultshows that biocomposites by addition of CNC and citric acid have a smooth surface and homogeneous distribution of fillers. The tensile strength of biocomposites was increased by addition CNC and citric acid. The addition of CNC decreases the elongation at break but by addition of citric acid, the elongation at break was increased.

Neurotensin-loaded PLGA/CNC composite nanofiber membranes accelerate diabetic wound healing.

PubMed

Zheng, Zhifang; Liu, Yishu; Huang, Wenhua; Mo, Yunfei; Lan, Yong; Guo, Rui; Cheng, Biao

2018-04-13

Diabetic foot ulcers (DFUs) are a threat to human health and can lead to amputation and even death. Recently neurotensin (NT), an inflammatory modulator in wound healing, was found to be beneficial for diabetic wound healing. As we demonstrated previously, polylactide-polyglycolide (PLGA) and cellulose nanocrystals (CNCs) (PLGA/CNC) nanofiber membranes show good cytocompatibility and facilitate fibroblast adhesion, spreading and proliferation. PLGA/CNC nanofiber membranes are novel materials that have not been used previously as NT carriers in diabetic wounds. This study aims to explore the therapeutic efficacy and possible mechanisms of NT-loaded PLGA/CNC nanofiber membranes in full-thickness skin wounds in spontaneously diabetic mice. The results showed that NT could be sustained released from NT-loaded PLGA/CNC composite nanofiber membranes for 2 weeks. NT-loaded PLGA/CNC composite nanofiber membranes induced more rapid healing than other control groups. After NT exposure, the histological scores of the epidermal and dermal regeneration and the ratios of the fibrotic area to the whole area were increased. NT-loaded PLGA/CNC composite nanofiber membranes also decreased the expressions of the inflammatory cytokines IL-1β and IL-6. These results suggest that NT-loaded PLGA/CNC composite nanofiber membranes for sustained delivery of NT should effectively promote tissue regeneration for the treatment of DFUs.

Processing and Characterization of Cellulose Nanocrystals/Polylactic Acid Nanocomposite Films

PubMed Central

Sullivan, Erin M.; Moon, Robert J.; Kalaitzidou, Kyriaki

2015-01-01

The focus of this study is to examine the effect of cellulose nanocrystals (CNC) on the properties of polylactic acid (PLA) films. The films are fabricated via melt compounding and melt fiber spinning followed by compression molding. Film fracture morphology, thermal properties, crystallization behavior, thermo-mechanical behavior, and mechanical behavior were determined as a function of CNC content using scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, dynamic mechanical analysis, and tensile testing. Film crystallinity increases with increasing CNC content indicating CNC act as nucleating agents, promoting crystallization. Furthermore, the addition of CNC increased the film storage modulus and slightly broadened the glass transition region. PMID:28793701

Modifying Mechanical, Optical Properties and Thermal Processability of Iridescent Cellulose Nanocrystal Films Using Ionic Liquid.

PubMed

Liu, Ping; Guo, Xin; Nan, Fuchun; Duan, Yongxin; Zhang, Jianming

2017-01-25

Iridescent films formed from the self-assembly of cellulose nanocrystals (CNCs) are brittle and difficult to handle or integrate within an industrial process. Here we present a simple approach to prepare iridescent CNC films with tunable pliability and coloration through the addition of ionic liquids (ILs) of 1-allyl-3-methylimidazolium chloride (AmimCl) as plasticizers. By using the undried CNC film as a filter membrane and ILs solution as a leaching liquid, it was found that the filtration process made ILs uniformly interpenetrate into CNC film due to the strong ionic interaction between CNC and AmimCl. Unexpectedly, the filtration process also gave rise to partial desulfurization of CNC film, which is conducive to the improvement of thermal stability. Benefiting from the improved thermal stability and the dissolving capacity of AmimCl for cellulose at high temperature, the incorporated ILs enable the cholesteric CNC film to be further toughened via a hot-pressing treatment. This study demonstrates that ionic liquids have great potential to modify the mechanical, optical properties as well as the thermal stability of iridescent CNC films.

Extraction of cellulose nano-crystals from old corrugated container fiber using phosphoric acid and enzymatic hydrolysis followed by sonication.

PubMed

Tang, Yanjun; Shen, Xiaochuang; Zhang, Junhua; Guo, Daliang; Kong, Fangong; Zhang, Nan

2015-07-10

Due to its amazing physicochemical properties and high environmental compatibility, cellulose nano-crystals (CNC) hold great promise for serving as a strategic platform for sustainable development. Now, there has been growing interest in the development of processes using waste or residual biomass as CNC source for addressing economic and environmental concerns. In the present work, a combined process involving phosphoric acid hydrolysis, enzymatic hydrolysis and sonication was proposed aiming to efficiently exact CNC from low-cost old corrugated container (OCC) pulp fiber. The effect of enzymatic hydrolysis on the yield and microstructure of resulting CNC was highlighted. Results showed that the enzymatic hydrolysis was effective in enhancing CNC yield after phosphoric acid hydrolysis. CNC was obtained with a yield of 23.98 wt% via the combined process with phosphoric acid concentration of 60 wt%, cellulase dosage of 2 mL (84 EGU) per 2g fiber and sonication intensity of 200 W. Moreover, the presence of enzymatic hydrolysis imparted the obtained CNC with improved dispersion, increased crystallinity and thermal stability. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lignin-coated cellulose nanocrystal filled methacrylate composites prepared via 3D stereolithography printing: Mechanical reinforcement and thermal stabilization.

PubMed

Feng, Xinhao; Yang, Zhaozhe; Chmely, Stephen; Wang, Qingwen; Wang, Siqun; Xie, Yanjun

2017-08-01

Various contents of lignin-coated cellulose nanocrystals (L-CNC) were incorporated into methacrylate (MA) resin and their mixture was used to prepare nanocomposites via 3D stereolithography (3D-SL) printing. Gaps were found between the L-CNC and MA matrix in 3D-SL printed nanocomposites before postcure. However, gaps decreased after postcure due to interactions between the L-CNC and MA molecules. Mechanical properties increased with the addition of 0.1% and 0.5% L-CNC after postcure, and the thermal stability was improved at 0.5% L-CNC. Dynamic mechanical analysis demonstrated that incorporation of L-CNC increased the storage modulus in the rubbery plateau. The loss factor had two transition regions, which gradually changed by merging together with increasing L-CNC content, and a broadening of the transition region was observed after postcure. In particular, the mechanical and thermal properties of 3D-SL printed nanocomposites, after postcure, exhibited higher improvement than those before postcure. Copyright © 2017 Elsevier Ltd. All rights reserved.

Improving the interfacial and mechanical properties of short glass fiber/epoxy composites by coating the glass fibers with cellulose nanocrystals

Treesearch

A. Asadi; M. Miller; Robert Moon; K. Kalaitzidou

2016-01-01

In this study, the interfacial and mechanical properties of cellulose nanocrystals (CNC) coated glass fiber/epoxy composites were investigated as a function of the CNC content on the surface of glass fibers (GF). Chopped GF rovings were coated with CNC by immersing the GF in CNC (0–5 wt%) aqueous suspensions. Single fiber fragmentation (SFF) tests showed that the...

Investigation of influence of errors of cutting machines with CNC on displacement trajectory accuracy of their actuating devices

NASA Astrophysics Data System (ADS)

Fedonin, O. N.; Petreshin, D. I.; Ageenko, A. V.

2018-03-01

In the article, the issue of increasing a CNC lathe accuracy by compensating for the static and dynamic errors of the machine is investigated. An algorithm and a diagnostic system for a CNC machine tool are considered, which allows determining the errors of the machine for their compensation. The results of experimental studies on diagnosing and improving the accuracy of a CNC lathe are presented.

An Investigation of the Potential Antifungal Properties of CNC-2 in Caenorhabditis elegans

PubMed Central

Zehrbach, Angelina M. D.; Rogers, Alexandra R.; Tarr, D. Ellen K.

2017-01-01

Caenorhabditis elegans responds to infections by upregulating specific antimicrobial peptides. The caenacin-2 (cnc-2) gene is consistently upregulated in C. elegans by infection with the filamentous fungus Drechmeria coniospora, but there have been no direct studies of the CNC-2 peptide’s in vivo or in vitro role in defending the nematode against this pathogen. We compared infection of wild-type and cnc-2 knockout nematode strains with four potential pathogens: D. coniospora, Candida albicans, Staphylococcus aureus, and Bacillus subtilis. There was no significant difference in survival between strains for any of the pathogens or on the maintenance strain of Escherichia coli. While we were unable to demonstrate definitively that CNC-2 is integral to fungal defenses in C. elegans, we identified possible explanations for these results as well as future work that is needed to investigate CNC-2’s potential as a new antifungal treatment. PMID:29353937

Structural isomers of C2N(+) - A selected-ion flow tube study

NASA Technical Reports Server (NTRS)

Knight, J. S.; Petrie, S. A. H.; Freeman, C. G.; Mcewan, M. J.; Mclean, A. D.

1988-01-01

Reactivities of the structural isomers CCN(+) and CNC(+) were examined in a selected-ion flow tube at 300 + or - 5 K. The less reactive CNC(+) isomer was identified as the product of the reactions of C(+) + HCN and C(+) + C2N2; in these reactions only CNC(+) can be produced because of energy constraints. Rate coefficients and branching ratios are reported for the reactions of each isomer with H2, CH4, NH3, H2O, C2H2, HCN, N2, O2, N2O, and CO2. Ab initio calculations are presented for CCN(+) and CNC(+); a saddle point for the reaction CCN(+) yielding CNC(+) is calculated to be 195 kJ/mol above CNC(+). The results provide evidence that the more reactive CCN(+) isomer is unlikely to be present in measurable densities in interstellar clouds.

An Investigation of the Potential Antifungal Properties of CNC-2 in Caenorhabditis elegans.

PubMed

Zehrbach, Angelina M D; Rogers, Alexandra R; Tarr, D Ellen K

2017-12-01

Caenorhabditis elegans responds to infections by upregulating specific antimicrobial peptides. The caenacin-2 ( cnc-2 ) gene is consistently upregulated in C. elegans by infection with the filamentous fungus Drechmeria coniospora , but there have been no direct studies of the CNC-2 peptide's in vivo or in vitro role in defending the nematode against this pathogen. We compared infection of wild-type and cnc-2 knockout nematode strains with four potential pathogens: D. coniospora , Candida albicans , Staphylococcus aureus , and Bacillus subtilis . There was no significant difference in survival between strains for any of the pathogens or on the maintenance strain of Escherichia coli . While we were unable to demonstrate definitively that CNC-2 is integral to fungal defenses in C. elegans , we identified possible explanations for these results as well as future work that is needed to investigate CNC-2's potential as a new antifungal treatment.

Binary PVA bio-nanocomposites containing cellulose nanocrystals extracted from different natural sources: part I.

PubMed

Fortunati, E; Puglia, D; Luzi, F; Santulli, C; Kenny, J M; Torre, L

2013-09-12

PVA bio-nanocomposites reinforced with cellulose nanocrystals (CNC) extracted from commercial microcrystalline cellulose (MCC) and from two types of natural fibres, Phormium tenax and Flax of the Belinka variety, were produced by solvent casting in water. Morphological, thermal, mechanical and transparency properties were studied while the respective efficiency of the extraction process of CNC from the three sources was evaluated. The effect of CNC types and content on PVA properties and water absorption capacity were also evaluated. Natural fibres offered higher levels of extraction efficiency when compared with MCC hydrolysis yield. Thermal analysis proved that CNC promotes the crystallization of the PVA matrix, while improving its plastic response. It was also clarified that all PVA/CNC systems remain transparent due to CNC dispersion at the nanoscale, while being all saturated after the first 18-24h of water absorption. Copyright © 2013 Elsevier Ltd. All rights reserved.

Basic leucine zipper protein Cnc-C is a substrate and transcriptional regulator of the Drosophila 26S proteasome.

PubMed

Grimberg, Kristian Björk; Beskow, Anne; Lundin, Daniel; Davis, Monica M; Young, Patrick

2011-02-01

While the 26S proteasome is a key proteolytic complex, little is known about how proteasome levels are maintained in higher eukaryotic cells. Here we describe an RNA interference (RNAi) screen of Drosophila melanogaster that was used to identify transcription factors that may play a role in maintaining levels of the 26S proteasome. We used an RNAi library against 993 Drosophila transcription factor genes to identify genes whose suppression in Schneider 2 cells stabilized a ubiquitin-green fluorescent protein reporter protein. This screen identified Cnc (cap 'n' collar [CNC]; basic region leucine zipper) as a candidate transcriptional regulator of proteasome component expression. In fact, 20S proteasome activity was reduced in cells depleted of cnc. Immunoblot assays against proteasome components revealed a general decline in both 19S regulatory complex and 20S proteasome subunits after RNAi depletion of this transcription factor. Transcript-specific silencing revealed that the longest of the seven transcripts for the cnc gene, cnc-C, was needed for proteasome and p97 ATPase production. Quantitative reverse transcription-PCR confirmed the role of Cnc-C in activation of transcription of genes encoding proteasome components. Expression of a V5-His-tagged form of Cnc-C revealed that the transcription factor is itself a proteasome substrate that is stabilized when the proteasome is inhibited. We propose that this single cnc gene in Drosophila resembles the ancestral gene family of mammalian nuclear factor erythroid-derived 2-related transcription factors, which are essential in regulating oxidative stress and proteolysis.

Reinforcement effect of poly(butylene succinate) (PBS)-grafted cellulose nanocrystal on toughened PBS/polylactic acid blends.

PubMed

Zhang, Xuzhen; Zhang, Yong

2016-04-20

Poly(butylene succinate) (PBS)/polylactic acid (PLA) blends modified with dicumyl peroxide (DCP) were reinforced by PBS-g-cellulose nanocrystal (CNC) through melt mixing. PBS-g-CNC was prepared through in situ polymerization and its structure was confirmed by FTIR, (13)C NMR, XPS and GPC analysis after saponification. The morphological analysis of PBS/PLA/PBS-g-CNC composites before and after etched by CH2Cl2 shows that the addition of DCP and PBS-g-CNC could decrease the size of PBS as a dispersed phase in PLA matrix and improve the dispersion of PBS-g-CNC in both PBS and PLA phases, which could affect the crystallization and mechanical properties of composites. The crystallinity of PLA α'-phase crystal in PBS/PLA/PBS-g-CNC composites is increased obviously by the addition of PBS-g-CNC, leading to an increase of the crystallinity of the composites. PBS/PLA blends modified by DCP have high Notched Izod impact strength and moduli, and the values are increased by the addition of PBS-g-CNC. Both storage modulus and glass translation temperature of PBS/PLA blend are increased by DCP and PBS-g-CNC, which is proved by DMA results, showing a weak molecular segment mobility of PBS/PLA matrix. The addition of DCP decreases the crystallization temperature and crystallinity of PBS/PLA composite, but increases the thermal stability of composites, mostly because of the crosslink effect of DCP on PBS/PLA matrix. Copyright © 2015 Elsevier Ltd. All rights reserved.

Processing and properties of eco-friendly bio-nanocomposite films filled with cellulose nanocrystals from sugarcane bagasse.

PubMed

El Achaby, Mounir; El Miri, Nassima; Aboulkas, Adil; Zahouily, Mohamed; Bilal, Essaid; Barakat, Abdellatif; Solhy, Abderrahim

2017-03-01

Novel synthesis strategy of eco-friendly bio-nanocomposite films have been exploited using cellulose nanocrystals (CNC) and polyvinyl alcohol/carboxymethyl cellulose (PVA/CMC) blend matrix as a potential in food packaging application. The CNC were extracted from sugarcane bagasse using sulfuric acid hydrolysis, and they were successfully characterized regarding their morphology, size, crystallinity and thermal stability. Thereafter, PVA/CMC-CNC bio-nanocomposite films, at various CNC contents (0.5-10wt%), were fabricated by the solvent casting method, and their properties were investigated. It was found that the addition of 5wt% CNC within a PVA/CMC increased the tensile modulus and strength by 141% and 83% respectively, and the water vapor permeability was reduced by 87%. Additionally, the bio-nanocomposites maintained the same transparency level of the PVA/CMC blend film (transmittance of ∼90% in the visible region), suggesting that the CNC were dispersed at the nanoscale. In these bio-nanocomposites, the adhesion properties and the large number of functional groups that are present in the CNC's surface and the macromolecular chains of the PVA/CMC blend are exploited to improve the interfacial interactions between the CNC and the blend. Consequently, these eco-friendly structured bio-nanocomposites with superior properties are expected to be useful in food packaging applications. Copyright © 2016. Published by Elsevier B.V.

The role and functions of Clinical Nurse Consultants, an Australian advanced practice role: a descriptive exploratory cohort study.

PubMed

Baldwin, Richard; Duffield, Christine Margaret; Fry, Margaret; Roche, Michael; Stasa, Helen; Solman, Annette

2013-03-01

The NSW Health Policy Directive (NSW Department of Health, 2000) lists clinical service and consultancy; clinical leadership; research; education; clinical services planning and management as the five domains of practice for nurses appointed as Clinical Nurse Consultants (CNCs), an Australian advanced practice nurse (APN) role. However, there is no clear definition of what is meant by advanced practice in the Australian nursing context. Nowhere is this more evident than in differentiating between the roles of Clinical Nurse Consultants (CNCs) and Nurse Practitioners (NP) in NSW. To date, limited empirical research has been done to characterise or delineate CNC role activity and responsibility. To investigate (i) the nature of CNC roles, activities and responsibilities, (ii) differentiate between CNCs by their work patterns and activities, and (iii) empirically conceptualize and differentiate ways CNCs practice in terms of an APN typology. The study sample was 56 CNCs at one tertiary level public hospital in Australia. A descriptive exploratory cohort study was conducted to explore CNC role characteristics and patterns of activity. Data were triangulated using an online survey, a follow-up survey, and semi-structured interviews. The data were analysed using descriptive statistics to examine differences between CNC work patterns and role activities. The survey data and the individual reports were thematically analysed to investigate for difference across the population of CNCs. Interpretation of survey and interview data led to an analyst-developed CNC typology of four CNC categories based on the work patterns and activities of Sole Practitioner, Clinic Coordinator, Clinical Team Coordinator and Clinical Leader. The typology was based on the themes interprofessional, role focus, clinical focus and setting as these themes distinguished and differentiated CNC roles. The study provides evidence of great diversity and prioritization within CNC roles. The CNC typology identified in this study is similar to the categorisation of the roles of APNs reported by other researchers. With further testing, the CNC typology could be useful to service managers and policy makers in making decision on the category of CNC required for a position and may also be able to be applied to other APN roles. Copyright © 2012 Elsevier Ltd. All rights reserved.

New estradiol-linked nitrosoureas: can the pharmacokinetic properties help to explain the pharmacodynamic activities?

PubMed

Betsch, B; Berger, M R; Spiegelhalder, B; Eisenbrand, G; Schmähl, D

1989-01-01

The pharmacokinetics of 1-(2-chloroethyl)-1-nitrosocarbamoyl-L-alanine-estradiol-17-ester (CNC-alanine-estradiol-17-ester) a new estradiol-linked anticancer drug and the unlinked DNA-crosslinking agent 1-(2-chloroethyl)-1-nitrosocarbamoyl-L-alanine (CNC-alanine) have been studied in methylnitrosourea-induced female Sprague-Dawley rats after equimolar intravenous and oral administration. In comparison with the unlinked single agent, the CNC-alanine-estradiol-17-ester showed a 3-fold longer halflife in plasma and a three times larger volume of distribution. The distribution after intravenous administration was nearly three times faster. The absorption after peroral administration was likewise two times faster. The bioavailability of the estradiol-linked drug was determined to be 52%. After application of CNC-alanine-estradiol-17-ester the cytostatic metabolite CNC-alanine was found, indicating the cleavage of the ester bond. CNC-alanine generated from CNC-alanine-estradiol-17-ester showed a 50% longer halflife than when applied directly. The results indicate that linking 2-chloroethyl-nitrosoureas to estradiol can result in new anticancer agents with modified properties in comparison to the unlinked single agent. The higher antineoplastic activity of the hormone-linked drug can mainly be attributed to differences in the pharmacokinetic behaviour.

CNC Programming I.

ERIC Educational Resources Information Center

Casey, Joe

This document contains five units for a course in computer numerical control (CNC) for computer-aided manufacturing. It is intended to familiarize students with the principles and techniques necessary to create proper CNC programs manually. Each unit consists of an introduction, instructional objectives, learning materials, learning activities,…

Very low luminosity stars with very large amplitude flares

NASA Technical Reports Server (NTRS)

Schaefer, Bradley E.

1990-01-01

CCD frames of CZ Cnc, KY Cep, the gamma-ray burster optical transient, and NSV 12006 are analyzed. Also studied are 549 archival photographic plates of the CZ Cnc field. These observations are compared with the data of Lovas (1976). Flare events on CZ Cnc are examined. Based on the data it is noted that CZ Cnc is a main-sequence star, has a magnitude of 16.1, a distance of 100 pc, occasional large-amplitude flares, and frequent flares with amplitudes greater than 4 mag.

Representation of critical natural capital in China.

PubMed

Lü, Yihe; Zhang, Liwei; Zeng, Yuan; Fu, Bojie; Whitham, Charlotte; Liu, Shuguang; Wu, Bingfang

2017-08-01

Traditional means of assessing representativeness of conservation value in protected areas depend on measures of structural biodiversity. The effectiveness of priority conservation areas at representing critical natural capital (CNC) (i.e., an essential and renewable subset of natural capital) remains largely unknown. We analyzed the representativeness of CNC-conservation priority areas in national nature reserves (i.e., nature reserves under jurisdiction of the central government with large spatial distribution across the provinces) in China with a new biophysical-based composite indicator approach. With this approach, we integrated the net primary production of vegetation, topography, soil, and climate variables to map and rank terrestrial ecosystems capacities to generate CNC. National nature reserves accounted for 6.7% of CNC-conservation priority areas across China. Considerable gaps (35.2%) existed between overall (or potential) CNC representativeness nationally and CNC representation in national reserves, and there was significant spatial heterogeneity of representativeness in CNC-conservation priority areas at the regional and provincial levels. For example, the best and worst representations were, respectively, 13.0% and 1.6% regionally and 28.9% and 0.0% provincially. Policy in China is transitioning toward the goal of an ecologically sustainable civilization. We identified CNC-conservation priority areas and conservation gaps and thus contribute to the policy goals of optimization of the national nature reserve network and the demarcation of areas critical to improving the representativeness and conservation of highly functioning areas of natural capital. Moreover, our method for assessing representation of CNC can be easily adapted to other large-scale networks of conservation areas because few data are needed, and our model is relatively simple. © 2017 Society for Conservation Biology.

MR Spectroscopy to Distinguish between Supratentorial Intraventricular Subependymoma and Central Neurocytoma.

PubMed

Ueda, Fumiaki; Aburano, Hiroyuki; Ryu, Yasuji; Yoshie, Yuichi; Nakada, Mitsutoshi; Hayashi, Yutaka; Matsui, Osamu; Gabata, Toshifumi

2017-07-10

The purpose of this study was to discriminate supratentorial intraventricular subependymoma (SIS) from central neurocytoma (CNC) using magnetic resonance spectroscopy (MRS). Single-voxel proton MRS using a 1.5T or 3T MR scanner from five SISs, five CNCs, and normal controls were evaluated. They were examined using a point-resolved spectroscopy. Automatically calculated ratios comparing choline (Cho), N-acetylaspartate (NAA), myoinositol (MI), and/or glycine (Gly) to creatine (Cr) were determined. Evaluation of Cr to unsuppressed water (USW) was also performed. Mann-Whitney U test was carried out to test the significance of differences in the metabolite ratios. Detectability of lactate (Lac) and alanine (Ala) was evaluated. Although a statistically significant difference (P < 0.0001) was observed in Cho/Cr among SIS, control spectra, and CNC, no statistical difference was noted between SIS and control spectra (P = 0.11). Statistically significant differences were observed in NAA/Cr between SIS and CNC (P = 0.04) or control spectra (P < 0.0001). A statistically significant difference was observed in MI and/or Gly to Cr between SIS and control spectra (P = 0.03), and CNC and control spectra (P < 0.0006). There were no statistical differences between SIS and CNC for MI and/or Gly to Cr (P = 0.32). Significant statistical differences were found between SIS and control spectra (P < 0.0053), control spectra and CNC (P < 0.0016), and SIS and CNC (P < 0.0083) for Cr to USW. Lac inverted doublets were confirmed in two SISs. Triplets of Lac and Ala were detected in four spectra of CNC. The present study showed that MRS can be useful in discriminating SIS from CNC.

Improving Energy Efficiency in CNC Machining

NASA Astrophysics Data System (ADS)

Pavanaskar, Sushrut S.

We present our work on analyzing and improving the energy efficiency of multi-axis CNC milling process. Due to the differences in energy consumption behavior, we treat 3- and 5-axis CNC machines separately in our work. For 3-axis CNC machines, we first propose an energy model that estimates the energy requirement for machining a component on a specified 3-axis CNC milling machine. Our model makes machine-specific predictions of energy requirements while also considering the geometric aspects of the machining toolpath. Our model - and the associated software tool - facilitate direct comparison of various alternative toolpath strategies based on their energy-consumption performance. Further, we identify key factors in toolpath planning that affect energy consumption in CNC machining. We then use this knowledge to propose and demonstrate a novel toolpath planning strategy that may be used to generate new toolpaths that are inherently energy-efficient, inspired by research on digital micrography -- a form of computational art. For 5-axis CNC machines, the process planning problem consists of several sub-problems that researchers have traditionally solved separately to obtain an approximate solution. After illustrating the need to solve all sub-problems simultaneously for a truly optimal solution, we propose a unified formulation based on configuration space theory. We apply our formulation to solve a problem variant that retains key characteristics of the full problem but has lower dimensionality, allowing visualization in 2D. Given the complexity of the full 5-axis toolpath planning problem, our unified formulation represents an important step towards obtaining a truly optimal solution. With this work on the two types of CNC machines, we demonstrate that without changing the current infrastructure or business practices, machine-specific, geometry-based, customized toolpath planning can save energy in CNC machining.

Cellulose Nanocrystal Membranes as Excipients for Drug Delivery Systems

PubMed Central

Barbosa, Ananda M.; Robles, Eduardo; Ribeiro, Juliana S.; Lund, Rafael G.; Carreño, Neftali L. V.; Labidi, Jalel

2016-01-01

In this work, cellulose nanocrystals (CNCs) were obtained from flax fibers by an acid hydrolysis assisted by sonochemistry in order to reduce reaction times. The cavitation inducted during hydrolysis resulted in CNC with uniform shapes, and thus further pretreatments into the cellulose are not required. The obtained CNC exhibited a homogeneous morphology and high crystallinity, as well as typical values for surface charge. Additionally, CNC membranes were developed from CNC solution to evaluation as a drug delivery system by the incorporation of a model drug. The drug delivery studies were carried out using chlorhexidine (CHX) as a drug and the antimicrobial efficiency of the CNC membrane loaded with CHX was examined against Gram-positive bacteria Staphylococcus aureus (S. Aureus). The release of CHX from the CNC membranes is determined by UV-Vis. The obtaining methodology of the membranes proved to be simple, and these early studies showed a potential use in antibiotic drug delivery systems due to the release kinetics and the satisfactory antimicrobial activity. PMID:28774122

Cr(OH)3-NPs-CNC hybrid nanocomposite: a sorbent for adsorptive removal of methylene blue and malachite green from solutions.

PubMed

Nekouei, Farzin; Nekouei, Shahram; Keshtpour, Farzaneh; Noorizadeh, Hossein; Wang, Shaobin

2017-11-01

In this article, Cr(OH) 3 nanoparticle-modified cellulose nanocrystal (CNC) as a novel hybrid nanocomposite (Cr(OH) 3 -NPs-CNC) was prepared by a simple procedure and used as a sorbent for adsorptive removal of methylene blue (MB) and malachite green (MG) from aqueous solution. Different kinetic models were tested, and the pseudo-second-order kinetic model was found more suitable for the MB and MG adsorption processes. The BET and Langmuir models were more suitable for the adsorption processes of MB and MG. Thermodynamic studies suggested that the adsorption of MB and MG onto Cr(OH) 3 -NPs-CNC nanocomposite was a spontaneous and endothermic process. The maximum adsorption capacities for MB and MG were reached 106 and 104 mg/g, respectively, which were almost two times higher than unmodified CNC. The chemical stability and leaching tests of the Cr(OH) 3 -NPs-CNC hybrid nanocomposite showed that only small amounts of chromium were leached into the solution.

Synthesis and Swelling Behavior of pH-Sensitive Semi-IPN Superabsorbent Hydrogels Based on Poly(acrylic acid) Reinforced with Cellulose Nanocrystals

PubMed Central

Lim, Lim Sze; Rosli, Noor Afizah; Ahmad, Ishak; Mat Lazim, Azwan; Mohd Amin, Mohd Cairul Iqbal

2017-01-01

pH-sensitive poly(acrylic acid) (PAA) hydrogel reinforced with cellulose nanocrystals (CNC) was prepared. Acrylic acid (AA) was subjected to chemical cross-linking using the cross-linking agent MBA (N,N-methylenebisacrylamide) with CNC entrapped in the PAA matrix. The quantity of CNC was varied between 0, 5, 10, 15, 20, and 25 wt %. X-ray diffraction (XRD) data showed an increase in crystallinity with the addition of CNC, while rheology tests demonstrated a significant increase in the storage modulus of the hydrogel with an increase in CNC content. It was found that the hydrogel reached maximum swelling at pH 7. The potential of the resulting hydrogels to act as drug carriers was then evaluated by means of the drug encapsulation efficiency test using theophylline as a model drug. It was observed that 15% CNC/PAA hydrogel showed the potential to be used as drug carrier system. PMID:29156613

PRKAR1A mutation causing pituitary-dependent Cushing disease in a patient with Carney complex.

PubMed

Kiefer, Florian W; Winhofer, Yvonne; Iacovazzo, Donato; Korbonits, Márta; Wolfsberger, Stefan; Knosp, Engelbert; Trautinger, Franz; Höftberger, Romana; Krebs, Michael; Luger, Anton; Gessl, Alois

2017-08-01

Carney complex (CNC) is an autosomal dominant condition caused, in most cases, by an inactivating mutation of the PRKAR1A gene, which encodes for the type 1 alpha regulatory subunit of protein kinase A. CNC is characterized by the occurrence of endocrine overactivity, myxomas and typical skin manifestations. Cushing syndrome due to primary pigmented nodular adrenocortical disease (PPNAD) is the most frequent endocrine disease observed in CNC. Here, we describe the first case of a patient with CNC and adrenocorticotropic hormone (ACTH)-dependent Cushing disease due to a pituitary corticotroph adenoma. Loss-of-heterozygosity analysis of the pituitary tumour revealed loss of the wild-type copy of PRKAR1A , suggesting a role of this gene in the pituitary adenoma development. PRKAR1A loss-of-function mutations can rarely lead to ACTH-secreting pituitary adenomas in CNC patients. Pituitary-dependent disease should be considered in the differential diagnosis of Cushing syndrome in CNC patients. © 2017 European Society of Endocrinology.

A3-Coupling catalyzed by robust Au nanoparticles covalently bonded to HS-functionalized cellulose nanocrystalline films

PubMed Central

Huang, Jian-Lin

2013-01-01

Summary We decorated HS-functionalized cellulose nanocrystallite (CNC) films with monodisperse Au nanoparticles (AuNPs) to form a novel nanocomposite catalyst AuNPs@HS-CNC. The uniform, fine AuNPs were made by the reduction of HAuCl4 solution with thiol (HS-) group-functionalized CNC films. The AuNPs@HS-CNC nanocomposites were examined by X-ray photoelectron spectroscopy (XPS), TEM, ATR-IR and solid-state NMR. Characterizations suggested that the size of the AuNPs was about 2–3 nm and they were evenly distributed onto the surface of CNC films. Furthermore, the unique nanocomposite Au@HS-CNC catalyst displayed high catalytic efficiency in promoting three-component coupling of an aldehyde, an alkyne, and an amine (A3-coupling) either in water or without solvent. Most importantly, the catalyst could be used repetitively more than 11 times without significant deactivation. Our strategy also promotes the use of naturally renewable cellulose to prepare reusable nanocomposite catalysts for organic synthesis. PMID:23946833

PVA bio-nanocomposites: a new take-off using cellulose nanocrystals and PLGA nanoparticles.

PubMed

Rescignano, N; Fortunati, E; Montesano, S; Emiliani, C; Kenny, J M; Martino, S; Armentano, I

2014-01-01

The formation of a new generation of hybrid bio-nanocomposites is reported: these are intended at modulating the mechanical, thermal and biocompatibility properties of the poly(vinyl alcohol) (PVA) by the combination of cellulose nanocrystals (CNC) and poly (D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs) loaded with bovine serum albumin fluorescein isothiocynate conjugate (FITC-BSA). CNC were synthesized from microcrystalline cellulose by hydrolysis, while PLGA nanoparticles were produced by a double emulsion with subsequent solvent evaporation. Firstly, binary bio-nanocomposites with different CNC amounts were developed in order to select the right content of CNC. Next, ternary PVA/CNC/NPs bio-nanocomposites were developed. The addition of CNC increased the elongation properties without compromising the other mechanical responses. Thermal analysis underlined the nucleation effect of the synergic presence of cellulose and nanoparticles. Remarkably, bio-nanocomposite films are suitable to vehiculate biopolymeric nanoparticles to adult bone marrow mesenchymal stem cells successfully, thus representing a new tool for drug delivery strategies. Copyright © 2013 Elsevier Ltd. All rights reserved.

Two different techniques of manufacturing TMJ replacements - A technical report.

PubMed

Kozakiewicz, Marcin; Wach, Tomasz; Szymor, Piotr; Zieliński, Rafał

2017-09-01

Presently, during the surgical treatment of the patients in maxillofacial surgery, one can use various medical implants. Moreover custom made implants are being used. Replacements may be fitted to the structure and shape of the human skull owing to CAD/CAM (custom aided design/manufacture) called customized implants. This study was aimed to report for the first time clinical material from which custom implants, using two different techniques, were manufactured to reconstruct the temporomandibular joint (TMJ). In this study, eleven patients with an average age of 54 years were included. All of the patients underwent TMJ reconstruction using direct metal laser sintering (DMLS) or computer numerical control milling (CNC) techniques for implant manufacture. Four of the eleven patients had a malignancy diagnosis, and seven had a benign diagnosis. Patients complained of hypomobility of the TMJ, facial asymmetry, pain and swelling of the preauricular region. Treatment included 7 CNC milled implants and 4 implants in DMLS. More metallic implant parts with a rough surface were associated with the DMLS technique. Post operational, uneventful healing was observed in all clinical cases during an average of 26.8 months of follow-up. Three months post-operation, facial nerve palsy, swallowing disturbances and pain were not observed. Infections, allergic reactions to materials and re-ankylosis were also not observed. Replacements received correct forms and functions owing to the CAM techniques. Post-operational maximal interincisal opening improved (p < 0.01) and was not significantly related to preoperational opening, age, sex, diagnosis or adjuvant radiotherapy. Considering both methods, the feature that differentiates the manufacture technique is the more subtractive surface finishing required for the DMLS implant than the CNC implant. Both techniques resulted the same clinical outcomes and can be used successfully in patients with neoplastic lesions and other TMJ disorders. Unfortunately, DMLS is more vulnerable to fracture. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Cellulose nanocrystal zero-valent iron nanocomposites for groundwater remediation†

PubMed Central

Bossa, Nathan; Carpenter, Alexis Wells; Kumar, Naresh; de Lannoy, Charles-François

2018-01-01

Zero-valent iron nanoparticles (nano-ZVIs) have been widely studied for in situ remediation of groundwater and other environmental matrices. Nano-ZVI particle mobility and reactivity are still the main impediments in achieving efficient in situ groundwater remediation. Compared to the nano-ZVI “coating” strategy, nano-ZVI stabilization on supporting material allows direct contact with the contaminant, reduces the electron path from the nano-ZVI to the target contaminant and increases nano-ZVI reactivity. Herein, we report the synthesis of nano-ZVI stabilized by cellulose nanocrystal (CNC) rigid nanomaterials (CNC-nano-ZVI; Fe/CNC = 1 w/w) with two different CNC functional surfaces (–OH and –COOH) using a classic sodium borohydride synthesis pathway. The final nanocomposites were thoroughly characterized and the reactivity of CNC-nano-ZVIs was assessed by their methyl orange (MO) dye degradation potential. The mobility of nanocomposites was determined in (sand/glass bead) porous media by utilizing a series of flowthrough transport column experiments. The synthesized CNC-nano-ZVI provided a stable colloidal suspension and demonstrated high mobility in porous media with an attachment efficiency (α) value of less than 0.23. In addition, reactivity toward MO increased up to 25% compared to bare ZVI. The use of CNC as a delivery vehicle shows promising potential to further improve the capability and applicability of nano-ZVI for in situ groundwater remediation and can spur advancements in CNC-based nanocomposites for their application in environmental remediation. PMID:29725541

Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)

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

Lim, Lim Sze; Ahmad, Ishak; Lazim, Mohd Azwani Shah Mat

2014-09-03

The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied.more » The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37°C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towards pH and temperature can be developed further as drug carrier.« less

Free radical grafting of gallic acid (GA) on cellulose nanocrystals (CNCS) and evaluation of antioxidant reinforced gellan gum films

NASA Astrophysics Data System (ADS)

Criado, P.; Fraschini, C.; Salmieri, S.; Becher, D.; Safrany, A.; Lacroix, M.

2016-01-01

Antiradical properties were introduced on cellulose nanocrystals (CNCs) by redox pair (RP) initiator and γ-radiation treatments. Different procedures were tested on CNC, first a 2 h reaction of hydrogen peroxide (H2O2)/ascorbic acid (AA) was performed on CNC solution. γ-Radiation treatment at 20 kGy dose was then applied and immediately after GA was reacted during 24 h with the pretreated CNCs, giving CNC-H2O2-AA-γ-GA. The formation of new carboxylic acids and carbonyl groups were characterized by FT-IR at 1650 and 1730 cm-1 respectively. Carboxylic acid functionalities were also analyzed by conductometric titration where an increase from 49 to 134 mmol COOH kg-1 was found from native to irradiated CNCs. A similar increase in the carboxylic acid content (132 mmol kg-1) was observed for CNC-H2O2-AA-γ-GA, showing the highest radical scavenging properties (8 mM Trolox eq/mg CNC). Thermogravimetric analysis confirmed the structural changes onto CNC. Film packaging containing 20% of CNC-H2O2-AA-γ-GA was then added to a gellan-based film packaging. A significant improvement (p<0.05) of the tensile strength (TS), the tensile modulus (TM) and the elongation at break (EB) and water vapor permeability reduction was observed when CNC-H2O2-AA-γ-GA was added to the film packaging formulation.

Advanced CNC Programming (EZ-CAM). 439-366.

ERIC Educational Resources Information Center

Casey, Joe

This document contains two units for an advanced course in computer numerical control (CNC) for computer-aided manufacturing. It is intended to familiarize students with the principles and techniques necessary to create proper CNC programs using computer software. Each unit consists of an introduction, instructional objectives, learning materials,…

Effect of cellulose nanocrystals (CNC) particle morphology on dispersion and rheological and mechanical properties of polypropylene/CNC nanocomposites.

PubMed

Khoshkava, Vahid; Kamal, Musa R

2014-06-11

Polypropylene (PP) nanocomposites containing spray-dried cellulose nanocrystals (CNC), freeze-dried CNC, and spray-freeze-dried CNC (CNCSFD) were prepared via melt mixing in an internal batch mixer. Polarized light, scanning electron, and atomic force microscopy showed significantly better dispersion of CNCSFD in PP/CNC nanocomposites compared with the spray-dried and freeze-dried CNCs. Rheological measurements, including linear and nonlinear viscoelastic tests, were performed on PP/CNC samples. The microscopy results were supported by small-amplitude oscillatory shear tests, which showed substantial rises in the magnitudes of key rheological parameters of PP samples containing CNCSFD. Steady-shear results revealed a strong shear thinning behavior of PP samples containing CNCSFD. Moreover, PP melts containing CNCSFD exhibited a yield stress. The magnitude of the yield stress and the degree of shear thinning behavior increased with CNCSFD concentration. It was found that CNCSFD agglomerates with a weblike structure were more effective in modifying the rheological properties. This effect was attributed to better dispersion of the agglomerates with the weblike structure. Dynamic mechanical analysis showed considerable improvement in the modulus of samples containing CNCSFD agglomerates. The percolation mechanical model with modified volume percolation threshold and filler network strength values and the Halpin-Kardos model were used to fit the experimental results.

Structure and sorption properties of CNC reinforced PVA films.

PubMed

Popescu, Maria-Cristina

2017-08-01

Bio-nanocomposite films based on cellulose nanocrystals reinforced poly(vinyl alcohol) were obtained by solvent casting method. To assess the structural features of the films, different spectral techniques (FTIR, 2D COS and XRD) have been used. Infrared and 2D correlation spectroscopy evidenced the presence of H-bond interactions between the PVA and CNC, and the variation in the conformational rearrangements, while XRD showed that the crystallite size and the crystallinity degree were affected by the incorporation of CNC. At low content of CNC in the PVA matrix, the crystallinity degree decreased to 29.9%, while at higher CNC content increased to 80.6%, comparing to PVA (35.4%). To evaluate the interaction with water, contact angle measurement, water sorption and NIR spectroscopy were used, respectively. The increase of the CNC content induced a reduction in water sorption ability from 93% for PVA to 75% for PVA/CNC films, indicating the involvement of the hydroxyl groups in new hydrogen bonded interactions. By analyzing the variation of the NIR bands from 1930, 1902 and 1985nm, was observed that the water molecules interact with the polymer matrix through moderate hydrogen bond before diffusing into the free volume of the matrix and form stronger hydrogen bonds. Copyright © 2017 Elsevier B.V. All rights reserved.

Calcitonin secretion in congenital nongoitrous cretinism.

PubMed

Carey, D E; Jones, K L; Parthemore, J G; Deftos, L J

1980-04-01

Plasma calcitonin (CT) was measured in the basal state and/or during provocative tests of hormone secretion in 11 children with congenital non-goitrous cretinism (CNC), in 1 girl with a lingual thyroid, and in 11 normal children. Basal and stimulated CT concentrations were significantly lower in the patients with CNC than in the normal subjects. Mean basal CT (+/- SE) was 41 +/- 4 pg/ml in the normal children, 24 +/- 3 pg/ml in the children with CNC, and 20 +/- 2 pg/ml in the patient with the lingual thyroid. The mean incremental CT responses to calcium infusion were 7.0 +/- 2 pg/ml in the children with CNC, 6.0 pg/ml in the patient with the lingual thyroid, and 146 +/- 47 pg/ml in the normal children. The children with CNC also demonstrated a significant delay in the return of the total serum calcium to basal level after the calcium infusion. The mean incremental CT response after infusion of pentagastrin was 7.6 +/- 2 pg/ml in the children with CNC, 10.0 pg/ml in the child with the lingual thyroid, and 34.4 +/- 11 pg/ml in the normal children. These data indicate that CT deficiency is present in children with CNC and suggest that the deficiency is a consequence of the defective embryologic development of the thyroid gland.

Characterization of bionanocomposite films prepared with agar and paper-mulberry pulp nanocellulose.

PubMed

Reddy, Jeevan Prasad; Rhim, Jong-Whan

2014-09-22

Crystallized nanocellulose (CNC) was separated from paper-mulberry (Broussonetia kazinoki Siebold) bast pulp by sulfuric acid hydrolysis method and they were blended with agar to prepare bionanocomposite films. The effect of CNC content (1, 3, 5 and 10 wt% based on agar) on the mechanical, water vapor permeability (WVP), and thermal properties of the nanocomposites were studied. Changes of the cellulose fibers in structure, morphology, crystallinity, and thermal properties of the films were evaluated using FT-IR, TEM, SEM, XRD, and TGA analysis methods. The CNC was composed of fibrous and spherical or elliptic granules of nano-cellulose with sizes of 50-60 nm. Properties of agar film such as mechanical and water vapor barrier properties were improved significantly (p<0.05) by blending with the CNC. The tensile modulus and tensile strength of agar film increased by 40% and 25%, respectively, in the composite film with 5 wt% of CNC, and the WVP of agar film decreased by 25% after formation of nanocomposite with 3 wt% of CNC. The CNC obtained from the paper-mulberry bast pulp can be used as a reinforcing agent for the preparation of bio-nanocomposites, and they have a high potential for the development of completely biodegradable food packaging materials. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cellulose nanocrystals (CNC) as carriers for a spirooxazine dye and its effect on photochromic efficiency.

PubMed

Sun, Bo; Hou, Qingxi; He, Zhibin; Liu, Zehua; Ni, Yonghao

2014-10-13

Nanocrystalline cellulose (CNC) as a renewable/sustainable material, has received much attention. Herein we studied CNC as carriers for a hydrophobic spirooxazine (SO)-based dye, 1,3-dihydro-1,3,3-trimethylspiro[2H-indole-2,3'-[3H]naphtha[2,1-b][1,4]oxazine], which may have potential applications in reversible memory photo-devices, textiles, photo-sensitive paper coatings, and inkjet printing inks. Due to the high cost and water-insolubility of this dye, it is desirable to improve its coloration efficiency and water-dispersibility. The experimental approach was to use CNC as carriers for the SO dye, thus obtaining a stable photochromic dye in aqueous systems. Transmission electron microscope (TEM) observation confirmed that the SO dye adsorbed on the surface of the CNC, which functioned as carriers for the photochromic dye. An impregnation process was adopted to anchor the dye onto cellulosic paper. It was found that the use of CNC resulted in a significant improvement in the SO coloration efficiency. The color stability and fatigue resistance were also studied. The use of CNC as carriers for a hydrophobic compound, its enhancement of associated properties, and its subsequent application were demonstrated. Copyright © 2014 Elsevier Ltd. All rights reserved.

Thickness dependence of curvature, strain, and response time in ionic electroactive polymer actuators fabricated via layer-by-layer assembly

NASA Astrophysics Data System (ADS)

Montazami, Reza; Liu, Sheng; Liu, Yang; Wang, Dong; Zhang, Qiming; Heflin, James R.

2011-05-01

Ionic electroactive polymer (IEAP) actuators containing porous conductive network composites (CNCs) and ionic liquids can result in high strain and fast response times. Incorporation of spherical gold nanoparticles in the CNC enhances conductivity and porosity, while maintaining relatively small thickness. This leads to improved mechanical strain and bending curvature of the actuators. We have employed the layer-by-layer self-assembly technique to fabricate a CNC with enhanced curvature (0.43 mm-1) and large net intrinsic strain (6.1%). The results demonstrate that curvature and net strain of IEAP actuators due to motion of the anions increase linearly with the thickness of the CNC as a result of the increased volume in which the anions can be stored. In addition, after subtracting the curvature of a bare Nafion actuator without a CNC, it is found that the net intrinsic strain of the CNC layer is independent of thickness for the range of 20-80 nm, indicating that the entire CNC volume contributes equivalently to the actuator motion. Furthermore, the response time of the actuator due to anion motion is independent of CNC thickness, suggesting that traversal through the Nafion membrane is the limiting factor in the anion motion.

Cellulose nanocrystal-based composite electrolyte with superior dimensional stability for alkaline fuel cell membranes

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

Lu, Yuan; Artmentrout, Aaron A.; Li, Juchuan

2015-05-13

Cellulose nanocrystal (CNC)-based composite films were prepared as a solid electrolyte for alkaline fuel cells. Poly (vinyl alcohol) (PVA) and silica gel hybrid was used to bind the CNCs to form a robust composite film. The mass ratio (i.e., 1 : 1, 1 : 2) of PVA and silica gel was tuned to control the hydrophobicity of the resulting films. Composite films with a range of CNC content (i.e., 20 to 60%) were prepared to demonstrate the impact of CNC on the performance of these materials as a solid electrolyte for alkaline fuel cells. Different from previously reported cross-linked polymermore » films, CNC-based composite films with 40% hydrophobic binder (i.e., PVA : silica gel=1 : 2) exhibited simultaneous low water swelling (e.g., ~5%) and high water uptake (e.g., ~80%) due to the hydrophilicity and extraordinary dimensional stability of CNC. It also showed a conductivity of 0.044 and 0.065 S/cm at 20 and 60 oC, respectively. To the best of our knowledge, the film with 60% CNC and 40% binder is characterized by the lowest hydroxide conductivity-normalized swelling ratio. Decreased CNC content (i.e., 40 and 20%) resulted in comparable hydroxide conductivity but a greater swelling ratio. Finally, these results demonstrate the advantage of CNC as a key component for a solid electrolyte for alkaline fuel cells over conventional polymers, suggesting the great potential of CNCs in improving the dimensional stability while maintaining the conductivity of existing anion exchange membranes.« less

Virtual Planning, Control, and Machining for a Modular-Based Automated Factory Operation in an Augmented Reality Environment

PubMed Central

Pai, Yun Suen; Yap, Hwa Jen; Md Dawal, Siti Zawiah; Ramesh, S.; Phoon, Sin Ye

2016-01-01

This study presents a modular-based implementation of augmented reality to provide an immersive experience in learning or teaching the planning phase, control system, and machining parameters of a fully automated work cell. The architecture of the system consists of three code modules that can operate independently or combined to create a complete system that is able to guide engineers from the layout planning phase to the prototyping of the final product. The layout planning module determines the best possible arrangement in a layout for the placement of various machines, in this case a conveyor belt for transportation, a robot arm for pick-and-place operations, and a computer numerical control milling machine to generate the final prototype. The robotic arm module simulates the pick-and-place operation offline from the conveyor belt to a computer numerical control (CNC) machine utilising collision detection and inverse kinematics. Finally, the CNC module performs virtual machining based on the Uniform Space Decomposition method and axis aligned bounding box collision detection. The conducted case study revealed that given the situation, a semi-circle shaped arrangement is desirable, whereas the pick-and-place system and the final generated G-code produced the highest deviation of 3.83 mm and 5.8 mm respectively. PMID:27271840

Virtual Planning, Control, and Machining for a Modular-Based Automated Factory Operation in an Augmented Reality Environment.

PubMed

Pai, Yun Suen; Yap, Hwa Jen; Md Dawal, Siti Zawiah; Ramesh, S; Phoon, Sin Ye

2016-06-07

This study presents a modular-based implementation of augmented reality to provide an immersive experience in learning or teaching the planning phase, control system, and machining parameters of a fully automated work cell. The architecture of the system consists of three code modules that can operate independently or combined to create a complete system that is able to guide engineers from the layout planning phase to the prototyping of the final product. The layout planning module determines the best possible arrangement in a layout for the placement of various machines, in this case a conveyor belt for transportation, a robot arm for pick-and-place operations, and a computer numerical control milling machine to generate the final prototype. The robotic arm module simulates the pick-and-place operation offline from the conveyor belt to a computer numerical control (CNC) machine utilising collision detection and inverse kinematics. Finally, the CNC module performs virtual machining based on the Uniform Space Decomposition method and axis aligned bounding box collision detection. The conducted case study revealed that given the situation, a semi-circle shaped arrangement is desirable, whereas the pick-and-place system and the final generated G-code produced the highest deviation of 3.83 mm and 5.8 mm respectively.

Virtual Planning, Control, and Machining for a Modular-Based Automated Factory Operation in an Augmented Reality Environment

NASA Astrophysics Data System (ADS)

Pai, Yun Suen; Yap, Hwa Jen; Md Dawal, Siti Zawiah; Ramesh, S.; Phoon, Sin Ye

2016-06-01

This study presents a modular-based implementation of augmented reality to provide an immersive experience in learning or teaching the planning phase, control system, and machining parameters of a fully automated work cell. The architecture of the system consists of three code modules that can operate independently or combined to create a complete system that is able to guide engineers from the layout planning phase to the prototyping of the final product. The layout planning module determines the best possible arrangement in a layout for the placement of various machines, in this case a conveyor belt for transportation, a robot arm for pick-and-place operations, and a computer numerical control milling machine to generate the final prototype. The robotic arm module simulates the pick-and-place operation offline from the conveyor belt to a computer numerical control (CNC) machine utilising collision detection and inverse kinematics. Finally, the CNC module performs virtual machining based on the Uniform Space Decomposition method and axis aligned bounding box collision detection. The conducted case study revealed that given the situation, a semi-circle shaped arrangement is desirable, whereas the pick-and-place system and the final generated G-code produced the highest deviation of 3.83 mm and 5.8 mm respectively.

Conversion economics of forest biomaterials: risk and financial analysis of CNC manufacturing

Treesearch

Camilla Abbati de Assis; Carl Houtman; Richard Phillips; E.M. Ted Bilek; Orlando J. Rojas; Lokendra Pal; Maria Soledad Peresin; Hasan Jameel; Ronalds Gonzalez

2017-01-01

Commercialization of cellulose nanocrystals (CNC) presents opportunities for a wide range of new products. Techno-economic assessments can provide insightful information for the effi cient design of conversion processes, drive cost-saving efforts, and reduce fi nancial risks. In this study, we conducted techno-economic assessments for CNC production using information...

Thermal Expansion of Self-Organized and Shear-Oriented Cellulose Nanocrystal Films

Treesearch

Jairo A. Diaz; Xiawa Wu; Ashlie Martini; Jeffrey P. Youngblood; Robert J. Moon

2013-01-01

The coefficient of thermal expansion (CTE) of cellulose nanocrystal (CNC) films was characterized using novel experimental techniques complemented by molecular simulations. The characteristic birefringence exhibited by CNC films was utilized to calculate the in-plane CTE of selforganized and shear-oriented self-standing CNC films from room temperature to 100 °...

Preparation of cellulose nanocrystals from asparagus (Asparagus officinalis L.) and their applications to palm oil/water Pickering emulsion.

PubMed

Wang, Wenhang; Du, Guanhua; Li, Cong; Zhang, Hongjie; Long, Yunduo; Ni, Yonghao

2016-10-20

Nano cellulosic materials as promising emulsion stabilizers have attracted great interest in food industry. In this paper, five different sized cellulose nanocrystals (CNC) samples were prepared from stem of Asparagus officinalis L. using the same sulfuric acid hydrolysis conditions but different times (1.5, 2, 2.5, 3.0, and 3.5h). The sizes of these CNC ranged from 178.2 to 261.8nm, with their crystallinity of 72.4-77.2%. The CNC aqueous dispersions showed a typical shear thinning behavior. In a palm oil/water (30/70, v/v) model solution, stable Pickering emulsions were formed with the addition of CNC, and their sizes are in the range of 1-10μm based on the optical and confocal laser scanning microscopy (CLSM) observation. The CNC sample prepared at 3h hydrolysis time, showed a relative efficient emulsion capacity for palm oil droplets, among these CNCs. Other parameters including the CNC, salt, and casein concentrations on the emulsion stability were studied. Copyright © 2016 Elsevier Ltd. All rights reserved.

Review on CNC-Rapid Prototyping

NASA Astrophysics Data System (ADS)

Z, M. Nafis O.; Y, Nafrizuan M.; A, Munira M.; J, Kartina

2012-09-01

This article reviewed developments of Computerized Numerical Control (CNC) technology in rapid prototyping process. Rapid prototyping (RP) can be classified into three major groups; subtractive, additive and virtual. CNC rapid prototyping is grouped under the subtractive category which involves material removal from the workpiece that is larger than the final part. Richard Wysk established the use of CNC machines for rapid prototyping using sets of 2½-D tool paths from various orientations about a rotary axis to machine parts without refixturing. Since then, there are few developments on this process mainly aimed to optimized the operation and increase the process capabilities to stand equal with common additive type of RP. These developments include the integration between machining and deposition process (hybrid RP), adoption of RP to the conventional machine and optimization of the CNC rapid prototyping process based on controlled parameters. The article ended by concluding that the CNC rapid prototyping research area has a vast space for improvement as in the conventional machining processes. Further developments and findings will enhance the usage of this method and minimize the limitation of current approach in building a prototype.

Repurposing mainstream CNC machine tools for laser-based additive manufacturing

NASA Astrophysics Data System (ADS)

Jones, Jason B.

2016-04-01

The advent of laser technology has been a key enabler for industrial 3D printing, known as Additive Manufacturing (AM). Despite its commercial success and unique technical capabilities, laser-based AM systems are not yet able to produce parts with the same accuracy and surface finish as CNC machining. To enable the geometry and material freedoms afforded by AM, yet achieve the precision and productivity of CNC machining, hybrid combinations of these two processes have started to gain traction. To achieve the benefits of combined processing, laser technology has been integrated into mainstream CNC machines - effectively repurposing them as hybrid manufacturing platforms. This paper reviews how this engineering challenge has prompted beam delivery innovations to allow automated changeover between laser processing and machining, using standard CNC tool changers. Handling laser-processing heads using the tool changer also enables automated change over between different types of laser processing heads, further expanding the breadth of laser processing flexibility in a hybrid CNC. This paper highlights the development, challenges and future impact of hybrid CNCs on laser processing.

Utilization of flax (Linum usitatissimum) cellulose nanocrystals as reinforcing material for chitosan films.

PubMed

Mujtaba, Muhammad; Salaberria, Asier M; Andres, María A; Kaya, Murat; Gunyakti, Ayse; Labidi, Jalel

2017-11-01

Use of plastic based packaging tools is causing both health and economic problems. To overcome this situation, researchers are focusing on the use of different biomaterials such as chitosan and cellulose. The current study was conducted to check the effect of flax (Linum usitatissimum) cellulose nanocrystals (CNC) on mechanical and barrier properties of chitosan-based films. CNC was incorporated in different concentrations (5, 10, 20 and 30%). CNC was isolated from flax fiber using acid hydrolysis method. Tensile strength (TS) and young modulus (YM) values increased with the increase of CNC concentration. Chitosan film with 20% CNC revealed the highest YM value as 52.35MPa. No significant improvement was recorded in water vapor permeability due to overall lower film crystallinity. All the films were observed to be transparent up to an acceptable level. SEM and AFM analysis confirmed the homogeneity of films. A gradual enhancement was recorded in the antimicrobial activity of chitosan/CNC composite films. No significant improvement revealed in the thermal stability of composites. Copyright © 2017 Elsevier B.V. All rights reserved.

Pulsation, binarity and close frequency spacing in $delta Scuti ta$ Scuti stars: BQ and BW Cancri. Results of the STEPHI VI campaign in Praesepe Cluster

NASA Astrophysics Data System (ADS)

Alvarez, M.; Hernandez, M. M.; Michel, E.; Jiang, S. Y.; Belmonte, J. A.; Chevreton, M.; Massacrier, G.; Liu, Y. Y.; Li, Z. P.; Goupil, M. J.; Cortes, T. Roca; Mangeney, A.; Dolez, N.; Valtier, J. C.; Vidal, I.; Sperl, M.; Talon, S.

1998-12-01

New pulsation modes in two delta Scuti stars of Praesepe cluster, BQ and BW Cnc, have been detected during the STEPHI VI campaign in 1995. In particular, 3 frequencies for BQ Cnc and 9 frequencies for BW Cnc have been found above a 99% confidence level. The possibility of the presence of a g-mode present in BQ Cnc is discussed, considering its binarity. The effect of mutual interference between very close detected frequencies in BW Cnc during the observations, is also considered. This last effect reveals the necessity of long-period observing runs, in order to avoid its influence in the final number of detected modes. In such situation, studies of secular amplitude changes can be strongly affected.

Open architecture design and approach for the Integrated Sensor Architecture (ISA)

NASA Astrophysics Data System (ADS)

Moulton, Christine L.; Krzywicki, Alan T.; Hepp, Jared J.; Harrell, John; Kogut, Michael

2015-05-01

Integrated Sensor Architecture (ISA) is designed in response to stovepiped integration approaches. The design, based on the principles of Service Oriented Architectures (SOA) and Open Architectures, addresses the problem of integration, and is not designed for specific sensors or systems. The use of SOA and Open Architecture approaches has led to a flexible, extensible architecture. Using these approaches, and supported with common data formats, open protocol specifications, and Department of Defense Architecture Framework (DoDAF) system architecture documents, an integration-focused architecture has been developed. ISA can help move the Department of Defense (DoD) from costly stovepipe solutions to a more cost-effective plug-and-play design to support interoperability.

An Investigation into the Properties and Microstructure of Cement Mixtures Modified with Cellulose Nanocrystal

PubMed Central

Flores, Jessica; Kamali, Mahsa; Ghahremaninezhad, Ali

2017-01-01

This paper aims to examine the effect of cellulose nanocrystals (CNC) on the hydration, transport behavior, and microstructure of cement mixtures. The addition of CNC delayed hydration at an early age but improved hydration at later ages. A small increase in the electrical resistivity of the cement mixtures with CNC was observed. Statistical nanoindentation showed a small tendency to a larger volume fraction of high density calcium-silicate-hydrate (C-S-H) and a smaller volume fraction of low-density C-S-H in the mixture with CNC. PMID:28772857

Integration and diversity of the regulatory network composed of Maf and CNC families of transcription factors.

PubMed

Motohashi, Hozumi; O'Connor, Tania; Katsuoka, Fumiki; Engel, James Douglas; Yamamoto, Masayuki

2002-07-10

Recent progress in the analysis of transcriptional regulation has revealed the presence of an exquisite functional network comprising the Maf and Cap 'n' collar (CNC) families of regulatory proteins, many of which have been isolated. Among Maf factors, large Maf proteins are important in the regulation of embryonic development and cell differentiation, whereas small Maf proteins serve as obligatory heterodimeric partner molecules for members of the CNC family. Both Maf homodimers and CNC-small Maf heterodimers bind to the Maf recognition element (MARE). Since the MARE contains a consensus TRE sequence recognized by AP-1, Jun and Fos family members may act to compete or interfere with the function of CNC-small Maf heterodimers. Overall then, the quantitative balance of transcription factors interacting with the MARE determines its transcriptional activity. Many putative MARE-dependent target genes such as those induced by antioxidants and oxidative stress are under concerted regulation by the CNC family member Nrf2, as clearly proven by mouse germline mutagenesis. Since these genes represent a vital aspect of the cellular defense mechanism against oxidative stress, Nrf2-null mutant mice are highly sensitive to xenobiotic and oxidative insults. Deciphering the molecular basis of the regulatory network composed of Maf and CNC families of transcription factors will undoubtedly lead to a new paradigm for the cooperative function of transcription factors.

Tailoring the yield and characteristics of wood cellulose nanocrystals (CNC) using concentrated acid hydrolysis

Treesearch

Liheng Chen; Qianqian Wang; Kolby Hirth; Carlos Baez; Umesh P. Agarwal; J. Y. Zhu

2015-01-01

Cellulose nanocrystals (CNC) have recently received much attention in the global scientific community for their unique mechanical and optical properties. Here, we conducted the first detailed exploration of the basic properties of CNC, such as morphology, crystallinity, degree of sulfation and yield, as a function of production condition variables. The rapid cellulose...

Negative results of growing titania nanotubes on cellulose nanocrystals - Effect of hydrothermal reaction

NASA Astrophysics Data System (ADS)

Chamakh, Mariem Mohamed; Ponnamma, Deepalekshmi; Al-Maadeed, Mariam Al Ali

Titania nanotubes (TiO2 nanotubes or TNT) are grown hydrothermally on cellulose nanocrystals (CNC) synthesized from microcrystalline cellulose. It is observed that the CNC are lost during synthesis due to its low thermal stability. This negative result of metal growth on CNC and its influence on thermal degradation are reported here.

76 FR 39156 - C&NC Railroad, LLC-Lease Renewal Exemption-Norfolk Southern Railway Company

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-05

... taking a close look at this transaction, the affected shippers, and the traffic flows, rather than... increase traffic levels. According to C&NC, the interchange point with NSR is New Castle. C&NC certifies... ``invest in improvements on the leased lines to increase traffic levels.'' But there is no reason to...

CNC Turning Center Advanced Operations. Computer Numerical Control Operator/Programmer. 444-332.

ERIC Educational Resources Information Center

Skowronski, Steven D.; Tatum, Kenneth

This student guide provides materials for a course designed to introduce the student to the operations and functions of a two-axis computer numerical control (CNC) turning center. The course consists of seven units. Unit 1 presents course expectations and syllabus, covers safety precautions, and describes the CNC turning center components, CNC…

Cap’n’collar differentiates the mandible from the maxilla in the beetle Tribolium castaneum

PubMed Central

2012-01-01

Background The biting mandible of the arthropods is thought to have evolved in the ancestor of the insects, crustaceans and myriapods: the Mandibulata. A unique origin suggests a common set of developmental genes will be required to pattern the mandible in different arthropods. To date we have functional studies on patterning of the mandibular segment of Drosophila melanogaster showing in particular the effects of the gene cap’n’collar (cnc), however, the dipteran head is far from representative of insects or of more distantly related mandibulates; Drosophila does not even possess a mandibular appendage. To study the development of a more representative insect mandible, we chose the red flour beetle Tribolium castaneum and investigated the function of the Tribolium orthologs of cap’n’collar (Tc-cnc) and the Hox gene Deformed (Tc-Dfd). In order to determine the function of Tc-cnc and Tc-Dfd, transcripts were knocked down by maternal RNA interference (RNAi). The effects of gene knockdown were examined in the developing embryos and larvae. The effect of Tc-cnc and Tc-Dfd knockdown on the expression of other genes was determined by using in situ hybridization on Tribolium embryos. Results Our analyses show that Tc-cnc is required for specification of the identity of the mandibular segment of Tribolium and differentiates the mandible from maxillary identity. Loss of Tc-cnc function results in a transformation of the mandible to maxillary identity as well as deletion of the labrum. Tc-Dfd and the Tribolium homolog of proboscipedia (Tc-mxp = maxillopedia), Hox genes that are required to pattern the maxillary appendage, are expressed in a maxilla-like manner in the transformed mandible. Tribolium homologs of paired (Tc-prd) and Distal-less (Tc-Dll) that are expressed in the endites and telopodites of embryonic appendages are also expressed in a maxilla-like manner in the transformed mandible. We also show that Tc-Dfd is required to activate the collar of Tc-cnc expression in the mandibular segment but not the cap expression in the labrum. Tc-Dfd is also required for the activation of Tc-prd in the endites of the mandible and maxillary appendages. Conclusions Tc-cnc is necessary for patterning the mandibular segment of Tribolium. Together, Tc-cnc and Tc-Dfd cooperate to specify mandibular identity, as in Drosophila. Expression patterns of the homologs of cnc and Dfd are conserved in mandibulate arthropods suggesting that the mandible specifying function of cnc is likely to be conserved across the mandibulate arthropods. PMID:23114106

Investigating the role of Clinical Nurse Consultants in one health district from multiple stakeholder perspectives: a cooperative inquiry.

PubMed

Walsh, Kenneth; Bothe, Janine; Edgar, Denise; Beaven, Geraldine; Burgess, Bernadette; Dickson, Vhari; Dunn, Stephen; Horning, Lynda; Jensen, Janice; Kandl, Bronia; Nonu, Miriam; Owen, Fran; Moss, Cheryle

2015-01-01

The impetus for this research came from a group of 11 Clinical Nurse Consultants (CNCs) within a health service in NSW, Australia, who wanted to investigate the CNC role from multiple stakeholder perspectives. With support from academic researchers, the CNCs designed and implemented the study. The aim of this research project was to investigate the role of the CNC from the multiple perspectives of CNCs and other stakeholders who work with CNCs in the Health District. This was a co-operative inquiry that utilised qualitative descriptive research approach. Co-operative inquiry methods enabled 11 CNCs to work as co-researchers and to conduct the investigation. The co-researchers implemented a qualitative descriptive design for the research and used interviews (7) and focus groups (16) with CNC stakeholders (n = 103) to gather sufficient data to investigate the role of the CNC in the organisation. Thematic analysis was undertaken to obtain the results. The CNC role is invaluable to all stakeholders and it was seen as the "glue" which holds teams together. Stakeholder expectations of the CNC role were multiple and generally agreed. Five themes derived from the data are reported as "clinical leadership as core", "making a direct difference to patient care", "service development as an outcome", "role breadth or narrowness and boundaries", and "career development". There was clear appreciation of the work that CNCs do in their roles, and the part that the CNC role plays in achieving quality health outcomes. The role of the CNC is complex and the CNCs themselves often negotiate these complexities to ensure beneficial outcomes for the patient and organisation. For the wider audience this study has given further insights into the role of these nurses and the perspectives of those with whom they work.

Inverse thermoreversible mechanical stiffening and birefringence in methylcellulose/cellulose nanocrystal hydrogel.

PubMed

Hynninen, Ville; Hietala, Sami; McKee, Jason Robert; Murtomäki, Lasse; Rojas, Orlando J; Ikkala, Olli; Nonappa, Nonappa

2018-05-07

We show that composite hydrogels comprising methyl cellulose (MC) and cellulose nanocrystal (CNC) colloidal rods display a reversible and enhanced rheological storage modulus and optical birefringence upon heating, i.e., inverse thermoreversibility. Dynamic rheology, quantitative polarized optical microscopy (POM), isothermal titration calorimetry (ITC), circular dichroism (CD), and scanning and transmission electron microscopy (SEM and TEM) were used for characterization. The concentration of CNC in aqueous media was varied up to 3.5 wt % (i.e, keeping the concentration below the critical aq. concentration) while maintaining the MC aq. concentration at 1.0 wt %. At 20 °C, MC/CNC underwent gelation upon passing the CNC concentration of 1.5 wt %. At this point the storage modulus (G´) reached a plateau, and the birefringence underwent a stepwise increase, thus suggesting a percolative phenomenon. The storage modulus (G´) of the composite gels was an order of magnitude higher at 60 °C compared to that at 20 °C. ITC results suggested that at 60 °C, the CNC rods were entropically driven to interact with MC chains, which according to recent studies, collapse at this temperature into ring-like, colloidal-scale persistent fibrils with hollow cross-section. Consequently, the increased requirement for space and mutual alignment of components results in enhanced birefringence. At room temperature, ITC shows enthalpic binding between CNCs and MC with the latter comprising an aqueous, molecularly dispersed polymer chains that lead to looser and less birefringent material. TEM, SEM, and CD indicated CNC chiral fragments within MC/CNC composite gel. Thus, their space-filling, thermoreversible assembly within the MC network can be used to tune the rheological properties and to access liquid crystalline properties at low CNC concentrations.

Growth Hormone and Risk for Cardiac Tumors in Carney Complex

PubMed Central

Bandettini, W. Patricia; Karageorgiadis, Alexander S.; Sinaii, Ninet; Rosing, Douglas R.; Sachdev, Vandana; Schernthaner-Reiter, Marie Helene; Gourgari, Evgenia; Papadakis, Georgios Z.; Keil, Meg F.; Lyssikatos, Charalampos; Carney, J. Aidan; Arai, Andrew E.; Lodish, Maya; Stratakis, Constantine A.

2016-01-01

Carney Complex (CNC) is a multiple neoplasia syndrome that is caused mostly by PRKAR1A mutations. Cardiac myxomas are the leading cause of mortality in CNC patients who, in addition, often develop growth hormone (GH) excess. We studied patients with CNC who were observed for over a period of 20 years (1995–2015) for the development of both GH excess and cardiac myxomas. GH secretion was evaluated by standard testing; dedicated cardiovascular imaging was used to detect cardiac abnormalities. Four excised cardiac myxomas were tested for expression of insulin-like growth factor-1 (IGF-1). A total of 99 CNC patients (97 with a PRKAR1A mutation) were included in the study with a mean age of 25.8 ± 16.6 years at presentation. Over an observed follow-up mean of 25.8 years, 60% of patients with GH excess (n=46) developed a cardiac myxoma compared to only 36% of those without GH excess (n=54) (p=0.016). Patients with GH excess were also overall more likely to have a tumor versus those with normal GH secretion (OR=2.78, 95% CI: 1.23–6.29; p=0.014). IGF-1 mRNA and protein were higher in CNC myxomas than in normal heart tissue. We conclude that the development of cardiac myxomas in CNC may be associated with increased GH secretion, in a manner analogous to the association between fibrous dysplasia and GH excess in McCune Albright syndrome, a condition similar to CNC. We speculate that treatment of GH excess in patients with CNC may reduce the likelihood of cardiac myxoma formation and/or recurrence of this tumor. PMID:27535175

The ectodomain of cadherin-11 binds to erbB2 and stimulates Akt phosphorylation to promote cranial neural crest cell migration

PubMed Central

Mathavan, Ketan; Khedgikar, Vikram; Bartolo, Vanessa

2017-01-01

During development, a multi-potent group of cells known as the cranial neural crest (CNC) migrate to form craniofacial structures. Proper migration of these cells requires proteolysis of cell adhesion molecules, such as cadherins. In Xenopus laevis, preventing extracellular cleavage of cadherin-11 impairs CNC migration. However, overexpression of the soluble cleavage product (EC1-3) is capable of rescuing this phenotype. The mechanism by which EC1-3 promotes CNC migration has not been investigated until now. Here we show that EC1-3 stimulates phosphorylation of Akt, a target of PI3K, in X.laevis CNC. Through immunoprecipitation experiments, we determined that EC1-3 interacts with all ErbB receptors, PDGFRα, and FGFR1. Of these receptors, only ErbB2 was able to produce an increase in Akt phosphorylation upon treatment with a recombinant EC1-3. This increase was abrogated by mubritinib, an inhibitor of ErbB2. We were able to recapitulate this decrease in Akt phosphorylation in vivo by knocking down ErbB2 in CNC cells. Knockdown of the receptor also significantly reduced CNC migration in vivo. We confirmed the importance of ErbB2 and ErbB receptor signaling in CNC migration using mubritinib and canertinib, respectively. Mubritinib and the PI3K inhibitor LY294002 significantly decreased cell migration while canertinib nearly prevented it altogether. These data show that ErbB2 and Akt are important for CNC migration and implicate other ErbB receptors and Akt-independent signaling pathways. Our findings provide the first example of a functional interaction between the extracellular domain of a type II classical cadherin and growth factor receptors. PMID:29190819

An essential role of variant histone H3.3 for ectomesenchyme potential of the cranial neural crest.

PubMed

Cox, Samuel G; Kim, Hyunjung; Garnett, Aaron Timothy; Medeiros, Daniel Meulemans; An, Woojin; Crump, J Gage

2012-09-01

The neural crest (NC) is a vertebrate-specific cell population that exhibits remarkable multipotency. Although derived from the neural plate border (NPB) ectoderm, cranial NC (CNC) cells contribute not only to the peripheral nervous system but also to the ectomesenchymal precursors of the head skeleton. To date, the developmental basis for such broad potential has remained elusive. Here, we show that the replacement histone H3.3 is essential during early CNC development for these cells to generate ectomesenchyme and head pigment precursors. In a forward genetic screen in zebrafish, we identified a dominant D123N mutation in h3f3a, one of five zebrafish variant histone H3.3 genes, that eliminates the CNC-derived head skeleton and a subset of pigment cells yet leaves other CNC derivatives and trunk NC intact. Analyses of nucleosome assembly indicate that mutant D123N H3.3 interferes with H3.3 nucleosomal incorporation by forming aberrant H3 homodimers. Consistent with CNC defects arising from insufficient H3.3 incorporation into chromatin, supplying exogenous wild-type H3.3 rescues head skeletal development in mutants. Surprisingly, embryo-wide expression of dominant mutant H3.3 had little effect on embryonic development outside CNC, indicating an unexpectedly specific sensitivity of CNC to defects in H3.3 incorporation. Whereas previous studies had implicated H3.3 in large-scale histone replacement events that generate totipotency during germ line development, our work has revealed an additional role of H3.3 in the broad potential of the ectoderm-derived CNC, including the ability to make the mesoderm-like ectomesenchymal precursors of the head skeleton.

Servo-controlling structure of five-axis CNC system for real-time NURBS interpolating

NASA Astrophysics Data System (ADS)

Chen, Liangji; Guo, Guangsong; Li, Huiying

2017-07-01

NURBS (Non-Uniform Rational B-Spline) is widely used in CAD/CAM (Computer-Aided Design / Computer-Aided Manufacturing) to represent sculptured curves or surfaces. In this paper, we develop a 5-axis NURBS real-time interpolator and realize it in our developing CNC(Computer Numerical Control) system. At first, we use two NURBS curves to represent tool-tip and tool-axis path respectively. According to feedrate and Taylor series extension, servo-controlling signals of 5 axes are obtained for each interpolating cycle. Then, generation procedure of NC(Numerical Control) code with the presented method is introduced and the method how to integrate the interpolator into our developing CNC system is given. And also, the servo-controlling structure of the CNC system is introduced. Through the illustration, it has been indicated that the proposed method can enhance the machining accuracy and the spline interpolator is feasible for 5-axis CNC system.

Supramolecular aggregates of metallo-organic acids with stilbazoles. Formation of columnar mesophases and Langmuir films.

PubMed

Domínguez, Cristina; Donnio, Bertrand; Coco, Silverio; Espinet, Pablo

2013-11-28

Supramolecular metal complexes formed through hydrogen bonding between tris(3,4,5-decyloxy)stilbazole and several metallo-organic acids of the type [Au(R)(CNC6H4CO2H)] (R = C6F5, C6F4OC10H21), [cis-[MCl2(CNC6H4COOH)2] and [trans-[MI2(CNC6H4COOH)2] (M = Pd, Pt) have been synthesized. All the supramolecular palladium and platinum polycatenar aggregates display a hexagonal columnar mesophase at temperatures close to room temperature. Most of the supramolecular trisalkoxystilbazole complexes exhibit luminescent behaviour. Aggregates of [Au(C6F4OC10H21)(CNC6H4CO2H)] and [trans-[MI2(CNC6H4COOH)2] (M = Pd, Pt) form stable Langmuir films at the air-water interface.

Understanding and Writing G & M Code for CNC Machines

ERIC Educational Resources Information Center

Loveland, Thomas

2012-01-01

In modern CAD and CAM manufacturing companies, engineers design parts for machines and consumable goods. Many of these parts are cut on CNC machines. Whether using a CNC lathe, milling machine, or router, the ideas and designs of engineers must be translated into a machine-readable form called G & M Code that can be used to cut parts to precise…

Lightweight sheet molding compound (SMC) composites containing cellulose nanocrystals

Treesearch

Amir Asadi; Mark Miller; Arjun V. Singh; Robert J. Moon; Kyriaki Kalaitzidou

2017-01-01

A scalable technique was introduced to produce high volume lightweight composites using sheet molding compound (SMC) manufacturing method by replacing 10 wt% glass fibers (GF) with a small amount of cellulose nanocrystals (CNC). The incorporation of 1 and 1.5 wt% CNC by dispersing in the epoxy matrix of short GF/epoxy SMC composites with 25 wt% GF content (25GF/CNC-...

Visual Times of Maxima for Short Period Pulsating Stars III

NASA Astrophysics Data System (ADS)

Samolyk, G.

2018-06-01

Abstract This compilation contains 524 times of maxima of 9 short period pulsating stars (primarily RR Lyrae stars; RW Cnc, TT Cnc, VZ Cnc, RR Cet, XZ Cyg, DM Cyg, RW Dra, XZ Dra, RR Gem). These were reduced from a portion of the visual observations made from 1966 to 2014 that are included in the AAVSO International Database.

Strategic Alliances: Making a Difference One Warfighter At a Time

DTIC Science & Technology

2011-03-12

Prototype Integration Planning Machining / CNC / Metals Welding Assembly / Paint Integration •Field-Experienced Veterans •Component, Subsystems...Wiring Harness •CAD/CAM CNC Programming •Quick reaction of parts - CNC , Lathes, Mills, Water Jet/Laser Cutting Design •Mechanical, Electrical...DEFORMATION RESISTANCE WELDING • Tubular Structural welding, Light weight structures COMBINED PLASMA -MIG ARC WELDING • Faster than any other

TACOM LCMC Industrial Base Networking Summit

DTIC Science & Technology

2010-03-25

CAD/CAM CNC Programming •Quick reaction of parts - CNC , Lathes , Mills, Water Jet/Laser Cutting Design •Mechanical, Electrical, Electronics...system that can efficiently fabricate standard and unique parts at the point of need • Lathe modules deployed at 4 strategic SWA locations • Concepts...Prototype Integration Planning Machining / CNC / Metals Welding Assembly / Paint Integration •Field-Experienced Veterans •Component, Subsystems

Biosensors from conjugated polyelectrolyte complexes

PubMed Central

Wang, Deli; Gong, Xiong; Heeger, Peter S.; Rininsland, Frauke; Bazan, Guillermo C.; Heeger, Alan J.

2002-01-01

A charge neutral complex (CNC) was formed in aqueous solution by combining an orange light emitting anionic conjugated polyelectrolyte and a saturated cationic polyelectrolyte at a 1:1 ratio (per repeat unit). Photoluminescence (PL) from the CNC can be quenched by both the negatively charged dinitrophenol (DNP) derivative, (DNP-BS−), and positively charged methyl viologen (MV2+). Use of the CNC minimizes nonspecific interactions (which modify the PL) between conjugated polyelectrolytes and biopolymers. Quenching of the PL from the CNC by the DNP derivative and specific unquenching on addition of anti-DNP antibody (anti-DNP IgG) were observed. Thus, biosensing of the anti-DNP IgG was demonstrated. PMID:11756675

Ruthenium(II) Complexes Containing Lutidine-Derived Pincer CNC Ligands: Synthesis, Structure, and Catalytic Hydrogenation of C-N bonds.

PubMed

Hernández-Juárez, Martín; López-Serrano, Joaquín; Lara, Patricia; Morales-Cerón, Judith P; Vaquero, Mónica; Álvarez, Eleuterio; Salazar, Verónica; Suárez, Andrés

2015-05-11

A series of Ru complexes containing lutidine-derived pincer CNC ligands have been prepared by transmetalation with the corresponding silver-carbene derivatives. Characterization of these derivatives shows both mer and fac coordination of the CNC ligands depending on the wingtips of the N-heterocyclic carbene fragments. In the presence of tBuOK, the Ru-CNC complexes are active in the hydrogenation of a series of imines. In addition, these complexes catalyze the reversible hydrogenation of phenantridine. Detailed NMR spectroscopic studies have shown the capability of the CNC ligand to be deprotonated and get involved in ligand-assisted activation of dihydrogen. More interestingly, upon deprotonation, the Ru-CNC complex 5 e(BF4 ) is able to add aldimines to the metal-ligand framework to yield an amido complex. Finally, investigation of the mechanism of the hydrogenation of imines has been carried out by means of DFT calculations. The calculated mechanism involves outer-sphere stepwise hydrogen transfer to the C-N bond assisted either by the pincer ligand or a second coordinated H2 molecule. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

On the polymorphic and morphological changes of cellulose nanocrystals (CNC-I) upon mercerization and conversion to CNC-II.

PubMed

Jin, Ersuo; Guo, Jiaqi; Yang, Fang; Zhu, Yangyang; Song, Junlong; Jin, Yongcan; Rojas, Orlando J

2016-06-05

Polymorphic and morphological transformations of cellulosic materials are strongly associated to their properties and applications, especially in the case of emerging nanocelluloses. Related changes that take place upon treatment of cellulose nanocrystals (CNC) in alkaline conditions are studied here by XRD, TEM, AFM, and other techniques. The results indicate polymorphic transformation of CNC proceeds gradually in a certain range of alkali concentrations, i.e. from about 8% to 12.5% NaOH. In such transition alkali concentration, cellulose I and II allomorphs coexists. Such value and range of the transition concentration is strongly interdependent with the crystallite size of CNCs. In addition, it is distinctively lower than that for macroscopic fibers (12-15% NaOH). Transmission electron microscopy and particle sizing reveals that after mercerization CNCs tend to associate. Furthermore, TEMPO-oxidized mercerized CNC reveals the morphology of individual nanocrystal of the cellulose II type, which is composed of some interconnected granular structures. Overall, this work reveals how the polymorphism and morphology of individual CNC change in alkali conditions and sheds light onto the polymorphic transition from cellulose I to II. Copyright © 2016 Elsevier Ltd. All rights reserved.

Needs of ergonomic design at control units in production industries.

PubMed

Levchuk, I; Schäfer, A; Lang, K-H; Gebhardt, Hj; Klussmann, A

2012-01-01

During the last decades, an increasing use of innovative technologies in manufacturing areas was monitored. A huge amount of physical workload was replaced by the change from conventional machine tools to computer-controlled units. CNC systems spread in current production processes. Because of this, machine operators today mostly have an observational function. This caused increasing of static work (e.g., standing, sitting) and cognitive demands (e.g., process observation). Machine operators have a high responsibility, because mistakes may lead to human injuries as well as to product losses - and in consequence may lead to high monetary losses (for the company) as well. Being usable often means for a CNC machine being efficient. An intuitive usability and an ergonomic organization of CNC workplaces can be an essential basis to reduce the risk of failures in operation as well as physical complaints (e.g. pain or diseases because of bad body posture during work). In contrast to conventional machines, CNC machines are equipped both with hardware and software. An intuitive and clear-sighted operating of CNC systems is a requirement for quick learning of new systems. Within this study, a survey was carried out among trainees learning the operation of CNC machines.

Additively Manufactured Titanium and Cobalt-Chromium Implant Frameworks: Fit and Effect of Ceramic Veneering.

PubMed

Svanborg, Per; Eliasson, Alf; Stenport, Victoria

The purpose of this study was to evaluate the fit of additively manufactured cobalt-chromium and titanium and CNC-milled titanium frameworks before and after ceramic veneering. Ten stone casts simulating an edentulous maxilla provided with six abutment analogs were produced. For each stone cast, one additively manufactured cobalt-chromium framework (AM CoCr) and one titanium framework (AM Ti) were fabricated. The fit was analyzed with a coordinate measuring machine in three dimensions (x, y, and z axes) using best-fit virtual matching of center point coordinates, before and after ceramic veneering. CNC-milled titanium frameworks (CNC Ti) and earlier results from CNC-milled cobalt-chromium frameworks (CNC CoCr) were used for comparison. All frameworks presented minor misfit before and after veneering in the horizontal plane (x- and y-axes) between 2.9 and 13.5 μm and in the vertical plane (z-axis) between 1.6 and 5.4 μm. Ceramic veneering affected the fit of all groups of frameworks. Both AM Ti and AM CoCr presented significantly smaller distortion in the vertical plane compared with the CNC-milled frameworks. Implant-supported frameworks can be produced in either Ti or CoCr using either CNC milling or additive manufacturing with a fit well within the range of 20 μm in the horizontal plane and 10 μm in the vertical plane. The fit of frameworks of both materials and production techniques are affected by the ceramic veneering procedure to a small extent.

Open System Architecture design for planet surface systems

NASA Technical Reports Server (NTRS)

Petri, D. A.; Pieniazek, L. A.; Toups, L. D.

1992-01-01

The Open System Architecture is an approach to meeting the needs for flexibility and evolution of the U.S. Space Exploration Initiative program of the manned exploration of the solar system and its permanent settlement. This paper investigates the issues that future activities of the planet exploration program must confront, defines the basic concepts that provide the basis for establishing an Open System Architecture, identifies the appropriate features of such an architecture, and discusses examples of Open System Architectures.

Tearing-off method based on single carbon nanocoil for liquid surface tension measurement

NASA Astrophysics Data System (ADS)

Wang, Peng; Pan, Lujun; Deng, Chenghao; Li, Chengwei

2016-11-01

A single carbon nanocoil (CNC) is used as a highly sensitive mechanical sensor to measure the surface tension coefficient of deionized water and alcohol in the tearing-off method. The error can be constrained to within 3.8%. Conversely, the elastic spring constant of a CNC can be accurately measured using a liquid, and the error is constrained to within 3.2%. Compared with traditional methods, the CNC is used as a ring and a sensor at the same time, which may simplify the measurement device and reduce error, also all measurements can be performed under a very low liquid dosage owing to the small size of the CNC.

Bio-inspired hydrophobic modification of cellulose nanocrystals with castor oil.

PubMed

Shang, Qianqian; Liu, Chengguo; Hu, Yun; Jia, Puyou; Hu, Lihong; Zhou, Yonghong

2018-07-01

This work presents an efficient and environmentally friendly approach to generate hydrophobic cellulose nanocrystals (CNC) using thiol-containing castor oil (CO-SH) as a renewable hydrophobe with the assist of bio-inspired dopamine at room temperature. The modification process included the formation of the polydopamine (PDA) buffer layer on CNC surfaces and the Michael addition reaction between the catechol moieties of PDA coating and thiol groups of CO-SH. The morphology, crystalline structure, surface chemistry, thermal stability and hydrophobicity of the modified CNC were charactered by TEM, XRD, FT-IR, solid-state 13 C NMR, XPS, TGA and contact angle analysis. The modified CNC preserved cellulose crystallinity, displayed higher thermal stability than unmodified CNC, and was highly hydrophobic with a water contact angle of 95.6°. The simplicity and versatility of the surface modification strategy inspired by adhesive protein of mussel may promote rapid development of hydrophobic bio-based nanomaterials for various applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

Water barrier properties of starch films reinforced with cellulose nanocrystals obtained from sugarcane bagasse.

PubMed

Slavutsky, Aníbal M; Bertuzzi, María A

2014-09-22

Water transport in edible films based on hydrophilic materials such as starch, is a complex phenomenon due to the strong interaction of sorbed water molecules with the polymeric structure. Cellulose nanocrystals (CNC) were obtained from sugarcane bagasse. Starch and starch/CNC films were formulated and their water barrier properties were studied. The measured film solubility, contact angle, and water sorption isotherm indicated that reinforced starch/CNC films have a lower affinity to water molecules than starch films. The effects that the driving force and the water activity (aw) values at each side of the film have on permeability were analyzed. Permeability, diffusivity, and solubility coefficients indicated that the permeation process depends mostly on the tortuous pathway formed by the incorporation of CNC and therefore were mainly controlled by water diffusion. The interaction between CNC and starch chain is favoured by the chemical similarities of both molecules. Copyright © 2014 Elsevier Ltd. All rights reserved.

Water adsorption on surface-modified cellulose nanocrystals

NASA Astrophysics Data System (ADS)

Wei, Zonghui; Sinko, Robert; Keten, Sinan; Luijten, Erik

Cellulose nanocrystals (CNCs) have attracted much attention as a filler phase for polymer nanocomposites due to their impressive mechanical properties, low cost, and environmental sustainability. Despite their promise for this application, there are still numerous obstacles that prevent optimal performance of CNC-polymer nanocomposites, such as poor filler dispersion and high levels of water absorption. One way to mitigate these negative effects is to modify CNC surfaces. Computational approaches can be utilized to obtain direct insight into the properties of modified CNC surfaces and probe the interactions of CNCs with other materials to facilitate the experimental design of nanocomposites. We use atomistic grand-canonical Monte Carlo simulations to study how surface modification of ion-exchanged sulfated cellulose nanocrystals (Na-CNCs) impacts water adsorption. We find that methyl(triphenyl)phosphonium-exchanged CNCs adsorb less water than Na-CNCs at the same relative humidity, supporting recent experimental dynamic vapor sorption measurements. By characterizing the distribution and configuration of water molecules near the modified CNC surfaces we determine how surface modifications disrupt CNC-water interactions.

Preparation of silver nano-particles immobilized onto chitin nano-crystals and their application to cellulose paper for imparting antimicrobial activity.

PubMed

Li, Zhihan; Zhang, Ming; Cheng, Dong; Yang, Rendang

2016-10-20

Immobilized silver nano-particles (Ag NPs) possess excellent antimicrobial properties due to their unique surface characteristics. In this paper, immobilized silver nano-particles were synthesized in the presence of chitin nano-crystals (CNC) based on the Tollens mechanism (reduction of silver ion by aldehydes in the chitosan oligosaccharides (COS)) under microwave-assisted conditions. The prepared Ag NPs-loaded CNC nano-composites were then applied onto the paper surface via coating for the preparation of antibacterial paper. Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) results confirmed that the Ag NPs were immobilized onto the CNC. The transmission electron microscope (TEM) and scanning electron microscopy (SEM) results further revealed that the spherical Ag NPs (5-12nm) were well dispersed on the surface of CNC. The coated paper made from the Ag NPs-loaded CNC nano-composites exhibited a high effectiveness of the antibacterial activity against E. coli or S. aureus. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preparation of the CNC/Ag/beeswax composites for enhancing antibacterial and water resistance properties of paper.

PubMed

Liu, Kai; Liang, Hunan; Nasrallah, Joseph; Chen, Lihui; Huang, Liulian; Ni, Yonghao

2016-05-20

An effective method of preparing composites containing inorganic (Ag) and organic (beeswax) particles was established in this study. Ag nanoparticles were first immobilized on the cellulose nanocrystals (CNC) during the reduction of AgNO3 in the presence of CNC, then mixed with beeswax by high speed stirring. Scanning transmission electron microscopy (STEM) images indicated that Ag and beeswax particles were uniformly dispersed and stable in the network structure formed by CNC. Upon coating on a paper surface, a layer of beeswax film was evident based on scanning electron microscopy (SEM) images. The dynamic contact angle and antibacterial activity tests indicated that the contact angle of coated paper reached 113.06° and the growth inhibition of Escherichia coli increased to 99.96%, respectively, at a coating amount of 21.53 g/m(2). When applied onto paper surface by coating, the CNC/Ag/beeswax composites can impact paper with antibacterial property and improved water resistance. Copyright © 2016 Elsevier Ltd. All rights reserved.

The N-Methyl-D-Aspartate Receptor in Heart Development: A Gene Knockdown Model Using siRNA

PubMed Central

Lie, Octavian V.; Bennett, Gregory D.; Rosenquist, Thomas H

2009-01-01

Antagonists of the N-methyl-D-aspartate receptor (NMDAR) may disrupt the development of the cardiac neural crest (CNC) and contribute to conotruncal heart defects. To test this interaction, a loss-of-function model was generated using small interfering RNAs (siRNA) directed against the critical NR1-subunit of this receptor in avian embryos. The coding sequence of the chicken NR1-gene and predicted protein sequences were characterized and found to be homologous with other vertebrate species. Analysis of its spatiotemporal expression demonstrated its expression within the neural tube at pre-migratory CNC sites. siRNA targeted to the NR1-mRNA in pre-migratory CNC lead to a significant decrease in NR1 protein expression. However, embryo survival and heart development were not adversely affected. These results indicate that the CNC may function normally in the absence of functional NMDAR, and that NMDAR antagonists may have a complex impact upon the CNC that transcends impairment of a single receptor type. PMID:19737608

Torsion fracture of carbon nanocoils

NASA Astrophysics Data System (ADS)

Yonemura, Taiichiro; Suda, Yoshiyuki; Tanoue, Hideto; Takikawa, Hirofumi; Ue, Hitoshi; Shimizu, Kazuki; Umeda, Yoshito

2012-10-01

We fix a carbon nanocoil (CNC) on a substrate in a focused ion beam instrument and then fracture the CNC with a tensile load. Using the CNC spring index, we estimate the maximum to average stress ratio on the fractured surface to range from 1.3 to 1.7, indicating stress concentration on the coil wire inner edge. Scanning electron microscopy confirms a hollow region on the inner edge of all fractured surfaces.

Occupational Noise Reduction in CNC Striping Process

NASA Astrophysics Data System (ADS)

Mahmad Khairai, Kamarulzaman; Shamime Salleh, Nurul; Razlan Yusoff, Ahmad

2018-03-01

Occupational noise hearing loss with high level exposure is common occupational hazards. In CNC striping process, employee that exposed to high noise level for a long time as 8-hour contributes to hearing loss, create physical and psychological stress that reduce productivity. In this paper, CNC stripping process with high level noises are measured and reduced to the permissible noise exposure. First condition is all machines shutting down and second condition when all CNC machine under operations. For both conditions, noise exposures were measured to evaluate the noise problems and sources. After improvement made, the noise exposures were measured to evaluate the effectiveness of reduction. The initial average noise level at the first condition is 95.797 dB (A). After the pneumatic system with leakage was solved, the noise reduced to 55.517 dB (A). The average noise level at the second condition is 109.340 dB (A). After six machines were gathered at one area and cover that area with plastic curtain, the noise reduced to 95.209 dB (A). In conclusion, the noise level exposure in CNC striping machine is high and exceed the permissible noise exposure can be reduced to acceptable levels. The reduction of noise level in CNC striping processes enhanced productivity in the industry.

ADAM13 cleavage of cadherin-11 promotes CNC migration independently of the homophilic binding site.

PubMed

Abbruzzese, Genevieve; Becker, Sarah F; Kashef, Jubin; Alfandari, Dominique

2016-07-15

The cranial neural crest (CNC) is a highly motile population of cells that is responsible for forming the face and jaw in all vertebrates and perturbing their migration can lead to craniofacial birth defects. Cell motility requires a dynamic modification of cell-cell and cell-matrix adhesion. In the CNC, cleavage of the cell adhesion molecule cadherin-11 by ADAM13 is essential for cell migration. This cleavage generates a shed extracellular fragment of cadherin-11 (EC1-3) that possesses pro-migratory activity via an unknown mechanism. Cadherin-11 plays an important role in modulating contact inhibition of locomotion (CIL) in the CNC to regulate directional cell migration. Here, we show that while the integral cadherin-11 requires the homophilic binding site to promote CNC migration in vivo, the EC1-3 fragment does not. In addition, we show that increased ADAM13 activity or expression of the EC1-3 fragment increases CNC invasiveness in vitro and blocks the repulsive CIL response in colliding cells. This activity requires the presence of an intact homophilic binding site on the EC1-3 suggesting that the cleavage fragment may function as a competitive inhibitor of cadherin-11 adhesion in CIL but not to promote cell migration in vivo. Copyright © 2015. Published by Elsevier Inc.

Harvey Cushing Treated the First Known Patient With Carney Complex.

PubMed

Tsay, Cynthia J; Stratakis, Constantine A; Faucz, Fabio Rueda; London, Edra; Stathopoulou, Chaido; Allgauer, Michael; Quezado, Martha; Dagradi, Terry; Spencer, Dennis D; Lodish, Maya

2017-10-01

Carney complex (CNC) is a syndrome characterized by hyperplasia of endocrine organs and may present with clinical features of Cushing syndrome and acromegaly due to functional adrenal and pituitary gland tumors. CNC has been linked to mutations in the regulatory subunit of protein kinase A type I-alpha ( PRKAR1A ) gene. Tissue samples were taken from the hypothalamus or thalamus or tumors of patients with pituitary adenomas seen and operated on by neurosurgeon Harvey Cushing between 1913 and 1932. Following DNA extraction, sequencing for genes of interest was attempted, including PRKAR1A , AIP , USP8 , GNAS1 , and GPR101 , to explore the possibility that these mutations associated with acromegaly, CNC, and Cushing syndrome have been conserved over time. We report a patient described by Dr. Cushing in 1914 with a clinical presentation and postmortem findings suggestive of CNC. Genetic sequencing of the hypothalamus and pituitary adenoma revealed a germline heterozygous p.Arg74His mutation in the PRKAR1A gene, a codon previously described as mutated in CNC, but with a novel amino acid change. This patient is, to our knowledge, the first molecularly confirmed individual with CNC. This case demonstrates the power of modern genetics in studying archived tissues and the importance of recording detailed clinical notes in the diagnosis of disease.

ADAM13 cleavage of cadherin-11 promotes CNC migration independently of the homophilic binding site

PubMed Central

Kashef, Jubin; Alfandari, Dominique

2015-01-01

The cranial neural crest (CNC) is a highly motile population of cells that is responsible for forming the face and jaw in all vertebrates and perturbing their migration can lead to craniofacial birth defects. Cell motility requires a dynamic modification of cell–cell and cell-matrix adhesion. In the CNC, cleavage of the cell adhesion molecule cadherin-11 by ADAM13 is essential for cell migration. This cleavage generates a shed extracellular fragment of cadherin-11 (EC1-3) that possesses pro-migratory activity via an unknown mechanism. Cadherin-11 plays an important role in modulating contact inhibition of locomotion (CIL) in the CNC to regulate directional cell migration. Here, we show that while the integral cadherin-11 requires the homophilic binding site to promote CNC migration in vivo, the EC1-3 fragment does not. In addition, we show that increased ADAM13 activity or expression of the EC1-3 fragment increases CNC invasiveness in vitro and blocks the repulsive CIL response in colliding cells. This activity requires the presence of an intact homophilic binding site on the EC1-3 suggesting that the cleavage fragment may function as a competitive inhibitor of cadherin-11 adhesion in CIL but not to promote cell migration in vivo. PMID:26206614

Nobeyama 45 m Cygnus-X CO Survey. I. Photodissociation of Molecules Revealed by the Unbiased Large-scale CN and C18O Maps

NASA Astrophysics Data System (ADS)

Yamagishi, M.; Nishimura, A.; Fujita, S.; Takekoshi, T.; Matsuo, M.; Minamidani, T.; Taniguchi, K.; Tokuda, K.; Shimajiri, Y.

2018-03-01

We present an unbiased large-scale (9 deg2) CN (N = 1–0) and C18O (J = 1–0) survey of Cygnus-X conducted with the Nobeyama 45 m Cygnus-X CO survey. CN and C18O are detected in various objects toward the Cygnus-X North and South (e.g., DR17, DR18, DR21, DR22, DR23, and W75N). We find that CN/C18O integrated intensity ratios are systematically different from region to region, and are especially enhanced in DR17 and DR18, which are irradiated by the nearby OB stars. This result suggests that CN/C18O ratios are enhanced via photodissociation reactions. We investigate the relation between the CN/C18O ratio and strength of the UV radiation field. As a result, we find that CN/C18O ratios correlate with the far-UV intensities, G 0. We also find that CN/C18O ratios decrease inside molecular clouds, where the interstellar UV radiation is reduced due to the interstellar dust extinction. We conclude that the CN/C18O ratio is controlled by the UV radiation, and is a good probe of photon-dominated regions.

Are computer numerical control (CNC)-manufactured patient-specific metal templates available for posterior thoracic pedicle screw insertion? Feasibility and accuracy evaluation.

PubMed

Kong, Xiangxue; Tang, Lei; Ye, Qiang; Huang, Wenhua; Li, Jianyi

2017-11-01

Accurate and safe posterior thoracic pedicle insertion (PTPI) remains a challenge. Patient-specific drill templates (PDTs) created by rapid prototyping (RP) can assist in posterior thoracic pedicle insertion, but pose biocompatibility risks. The aims of this study were to develop alternative PDTs with computer numerical control (CNC) and assess their feasibility and accuracy in assisting PTPI. Preoperative CT images of 31 cadaveric thoracic vertebras were obtained and then the optimal pedicle screw trajectories were planned. The PDTs with optimal screw trajectories were randomly assigned to be designed and manufactured by CNC or RP in each vertebra. With the guide of the CNC- or RP-manufactured PDTs, the appropriate screws were inserted into the pedicles. Postoperative CT scans were performed to analyze any deviations at entry point and midpoint of the pedicles. The CNC group was found to be significant manufacture-time-shortening, and cost-decreasing, when compared with the RP group (P < 0.01). The PDTs fitted the vertebral laminates well while all screws were being inserted into the pedicles. There were no significant differences in absolute deviations at entry point and midpoint of the pedicle on either axial or sagittal planes (P > 0.05). The screw positions were grade 0 in 90.3% and grade 1 in 9.7% of the cases in the CNC group and grade 0 in 93.5% and grade 1 in 6.5% of the cases in the RP group (P = 0.641). CNC-manufactured PDTs are viable for assisting in PTPI with good feasibility and accuracy.

pH-Responsive Shape Memory Poly(ethylene glycol)-Poly(ε-caprolactone)-based Polyurethane/Cellulose Nanocrystals Nanocomposite.

PubMed

Li, Ying; Chen, Hongmei; Liu, Dian; Wang, Wenxi; Liu, Ye; Zhou, Shaobing

2015-06-17

In this study, we developed a pH-responsive shape-memory polymer nanocomposite by blending poly(ethylene glycol)-poly(ε-caprolactone)-based polyurethane (PECU) with functionalized cellulose nanocrystals (CNCs). CNCs were functionalized with pyridine moieties (CNC-C6H4NO2) through hydroxyl substitution of CNCs with pyridine-4-carbonyl chloride and with carboxyl groups (CNC-CO2H) via 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) mediated surface oxidation, respectively. At a high pH value, the CNC-C6H4NO2 had attractive interactions from the hydrogen bonding between pyridine groups and hydroxyl moieties; at a low pH value, the interactions reduced or disappeared due to the protonation of pyridine groups, which are a Lewis base. The CNC-CO2H responded to pH variation in an opposite manner. The hydrogen bonding interactions of both CNC-C6H4NO2 and CNC-CO2H can be readily disassociated by altering pH values, endowing the pH-responsiveness of CNCs. When these functionalized CNCs were added in PECU polymer matrix to form nanocomposite network which was confirmed with rheological measurements, the mechanical properties of PECU were not only obviously improved but also the pH-responsiveness of CNCs could be transferred to the nanocomposite network. The pH-sensitive CNC percolation network in polymer matrix served as the switch units of shape-memory polymers (SMPs). Furthermore, the modified CNC percolation network and polymer molecular chains also had strong hydrogen bonding interactions among hydroxyl, carboxyl, pyridine moieties, and isocyanate groups, which could be formed or destroyed through changing pH value. The shape memory function of the nanocomposite network was only dependent on the pH variation of the environment. Therefore, this pH-responsive shape-memory nancomposite could be potentially developed into a new smart polymer material.

Atomic-scale modeling of cellulose nanocrystals

NASA Astrophysics Data System (ADS)

Wu, Xiawa

Cellulose nanocrystals (CNCs), the most abundant nanomaterials in nature, are recognized as one of the most promising candidates to meet the growing demand of green, bio-degradable and sustainable nanomaterials for future applications. CNCs draw significant interest due to their high axial elasticity and low density-elasticity ratio, both of which are extensively researched over the years. In spite of the great potential of CNCs as functional nanoparticles for nanocomposite materials, a fundamental understanding of CNC properties and their role in composite property enhancement is not available. In this work, CNCs are studied using molecular dynamics simulation method to predict their material' behaviors in the nanoscale. (a) Mechanical properties include tensile deformation in the elastic and plastic regions using molecular mechanics, molecular dynamics and nanoindentation methods. This allows comparisons between the methods and closer connectivity to experimental measurement techniques. The elastic moduli in the axial and transverse directions are obtained and the results are found to be in good agreement with previous research. The ultimate properties in plastic deformation are reported for the first time and failure mechanism are analyzed in details. (b) The thermal expansion of CNC crystals and films are studied. It is proposed that CNC film thermal expansion is due primarily to single crystal expansion and CNC-CNC interfacial motion. The relative contributions of inter- and intra-crystal responses to heating are explored. (c) Friction at cellulose-CNCs and diamond-CNCs interfaces is studied. The effects of sliding velocity, normal load, and relative angle between sliding surfaces are predicted. The Cellulose-CNC model is analyzed in terms of hydrogen bonding effect, and the diamond-CNC model compliments some of the discussion of the previous model. In summary, CNC's material properties and molecular models are both studied in this research, contributing to the present understanding of this material and leading to some possible future work.

Understanding Portability of a High-Level Programming Model on Contemporary Heterogeneous Architectures

DOE PAGES

Sabne, Amit J.; Sakdhnagool, Putt; Lee, Seyong; ...

2015-07-13

Accelerator-based heterogeneous computing is gaining momentum in the high-performance computing arena. However, the increased complexity of heterogeneous architectures demands more generic, high-level programming models. OpenACC is one such attempt to tackle this problem. Although the abstraction provided by OpenACC offers productivity, it raises questions concerning both functional and performance portability. In this article, the authors propose HeteroIR, a high-level, architecture-independent intermediate representation, to map high-level programming models, such as OpenACC, to heterogeneous architectures. They present a compiler approach that translates OpenACC programs into HeteroIR and accelerator kernels to obtain OpenACC functional portability. They then evaluate the performance portability obtained bymore » OpenACC with their approach on 12 OpenACC programs on Nvidia CUDA, AMD GCN, and Intel Xeon Phi architectures. They study the effects of various compiler optimizations and OpenACC program settings on these architectures to provide insights into the achieved performance portability.« less

Risk, Uncertainty and Open Architecture in the DoD Acquisition System

DTIC Science & Technology

2011-09-01

OPEN ARCHITECTURE IN THE DoD ACQUISITION SYSTEM by Scott F. Cole September 2011 Thesis Advisor: Thomas Housel Second Reader...DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE Risk, Uncertainty and Open Architecture in the DoD Acquisition System 5. FUNDING NUMBERS N...A number of risks and uncertainties will be identified and a determination will be made if Service Oriented Architecture (SOA) and Open

Metric Use in the Tool Industry. A Status Report and a Test of Assessment Methodology.

DTIC Science & Technology

1982-04-20

Weights and Measures) CIM - Computer-Integrated Manufacturing CNC - Computer Numerical Control DOD - Department of Defense DODISS - DOD Index of...numerically-controlled ( CNC ) machines that have an inch-millimeter selection switch and a corresponding dual readout scale. S -4- The use of both metric...satisfactorily met the demands of both domestic and foreign customers for metric machine tools by providing either metric- capable machines or NC and CNC

The in-situ 3D measurement system combined with CNC machine tools

NASA Astrophysics Data System (ADS)

Zhao, Huijie; Jiang, Hongzhi; Li, Xudong; Sui, Shaochun; Tang, Limin; Liang, Xiaoyue; Diao, Xiaochun; Dai, Jiliang

2013-06-01

With the development of manufacturing industry, the in-situ 3D measurement for the machining workpieces in CNC machine tools is regarded as the new trend of efficient measurement. We introduce a 3D measurement system based on the stereovision and phase-shifting method combined with CNC machine tools, which can measure 3D profile of the machining workpieces between the key machining processes. The measurement system utilizes the method of high dynamic range fringe acquisition to solve the problem of saturation induced by specular lights reflected from shiny surfaces such as aluminum alloy workpiece or titanium alloy workpiece. We measured two workpieces of aluminum alloy on the CNC machine tools to demonstrate the effectiveness of the developed measurement system.

Structural Reorganization of CNC in Injection-Molded CNC/PBAT Materials under Thermal Annealing.

PubMed

Mariano, Marcos; El Kissi, Nadia; Dufresne, Alain

2016-10-04

Composite materials were prepared by extrusion and injection molding from polybutyrate adipate terephthalate (PBAT) and high aspect ratio cellulose nanocrystals (CNCs) extracted from capim dourado fibers. Three CNC contents were used, corresponding to 0.5, 1, and 2 times the theoretical percolation threshold. Small-amplitude oscillary shear (SAOS) experiments show that as the CNC content increases, a more elastic behavior is observed but no percolating network can form within the polymeric matrix as a result of the high shear rates involved during the injection-molding process. Annealing of the samples at 170 °C was performed, and the possible reorganization of the nanofiller was investigated. This reorganization was further elucidated using 2D-SAOS and creep experiments.

Predictive Multiscale Modeling of Nanocellulose Based Materials and Systems

NASA Astrophysics Data System (ADS)

Kovalenko, Andriy

2014-08-01

Cellulose Nanocrysals (CNC) is a renewable biodegradable biopolymer with outstanding mechanical properties made from highly abundant natural source, and therefore is very attractive as reinforcing additive to replace petroleum-based plastics in biocomposite materials, foams, and gels. Large-scale applications of CNC are currently limited due to its low solubility in non-polar organic solvents used in existing polymerization technologies. The solvation properties of CNC can be improved by chemical modification of its surface. Development of effective surface modifications has been rather slow because extensive chemical modifications destabilize the hydrogen bonding network of cellulose and deteriorate the mechanical properties of CNC. We employ predictive multiscale theory, modeling, and simulation to gain a fundamental insight into the effect of CNC surface modifications on hydrogen bonding, CNC crystallinity, solvation thermodynamics, and CNC compatibilization with the existing polymerization technologies, so as to rationally design green nanomaterials with improved solubility in non-polar solvents, controlled liquid crystal ordering and optimized extrusion properties. An essential part of this multiscale modeling approach is the statistical- mechanical 3D-RISM-KH molecular theory of solvation, coupled with quantum mechanics, molecular mechanics, and multistep molecular dynamics simulation. The 3D-RISM-KH theory provides predictive modeling of both polar and non-polar solvents, solvent mixtures, and electrolyte solutions in a wide range of concentrations and thermodynamic states. It properly accounts for effective interactions in solution such as steric effects, hydrophobicity and hydrophilicity, hydrogen bonding, salt bridges, buffer, co-solvent, and successfully predicts solvation effects and processes in bulk liquids, solvation layers at solid surface, and in pockets and other inner spaces of macromolecules and supramolecular assemblies. This methodology enables rational design of CNC-based bionanocomposite materials and systems. Furthermore, the 3D-RISM-KH based multiscale modeling addresses the effect of hemicellulose and lignin composition on nanoscale forces that control cell wall strength towards overcoming plant biomass recalcitrance. It reveals molecular forces maintaining the cell wall structure and provides directions for genetic modulation of plants and pretreatment design to render biomass more amenable to processing. We envision integrated biomass valorization based on extracting and decomposing the non-cellulosic components to low molecular weight chemicals and utilizing the cellulose microfibrils to make CNC. This is an important alternative to approaches of full conversion of lignocellulose to biofuels that face challenges arising from the deleterious impact of cellulose crystallinity on enzymatic processing.

Reuse of red algae waste for the production of cellulose nanocrystals and its application in polymer nanocomposites.

PubMed

El Achaby, Mounir; Kassab, Zineb; Aboulkas, Adil; Gaillard, Cédric; Barakat, Abdellatif

2018-01-01

Red algae is widely available around the world and its exploitation for the production of agar products has become an important industry in recent years. The industrial processing of red algae generates a large quantity of solid fibrous wastes, which constitutes a source of serious environmental problems. In the present work, the utilization of red algae waste as raw material to produce high-quality cellulose nanocrystals (CNC) has been investigated, and the ability of the as-isolated CNC to reinforce polymer has been studied. Red algae waste was chemically treated via alkali, bleaching and acid hydrolysis treatments, in order to obtain pure cellulose microfibers and CNC. The raw waste and the as-extracted cellulosic materials were successively characterized at different stages of treatments using serval analysis techniques. It was found that needle-like shaped CNC were successfully isolated at nanometric scale with diameters and lengths ranged from 5.2±2.9 to 9.1±3.1nm, and from 285.4±36.5 to 315.7±30.3nm, respectively, and the crystallinity index ranged from 81 to 87%, depending on the hydrolysis time (30, 40 and 80min). The as-extracted CNC were used as nanofillers for the production of polyvinyl alcohol (PVA)-based nanocomposite films with improved thermal and tensile properties, as well as optical transparency. It is shown that the addition of 8wt% CNC into the PVA matrix increased the Young's modulus by 215%, the tensile strength by 150%, and the toughness by 45%. Additionally, the nanocomposite films maintained the same transparency level of the neat PVA film (transmittance of ∼90% in the visible region), suggesting that the CNC were dispersed at the nanoscale. Copyright © 2017 Elsevier B.V. All rights reserved.

Conscientious personality and young drivers’ crash risk

PubMed Central

Ehsani, Johnathon P.; Li, Kaigang; Simons-Morton, Bruce; Tree-McGrath, Cheyenne Fox; Perlus, Jessamyn; O’Brien, Fearghal; Klauer, Sheila G.

2015-01-01

Introduction Personality characteristics are associated with many risk behaviors. However, the relationship between personality traits, risky driving behavior, and crash risk is poorly understood. The purpose of this study was to examine the association between personality, risky driving behavior and crashes and near-crashes, using naturalistic driving research methods. Method Participants’ driving exposure, kinematic risky driving (KRD), high-risk secondary task engagement, and the frequency of crashes and near-crashes (CNC) were assessed over the first 18 months of licensure using naturalistic driving methods. A personality survey (NEO-Five Factor Inventory) was administered at baseline. The association between personality characteristics, KRD rate, secondary task engagement rate and CNC rate was estimated using a linear regression model. Mediation analysis was conducted to examine if participants’ KRD rate or secondary task engagement rate mediated the relationship between personality and CNC. Data were collected as part of the Naturalistic Teen Driving Study. Results Conscientiousness was marginally negatively associated with CNC (path c = −0.034, p = .09) and both potential mediators KRD (path a = −0.040, p = .09) and secondary task engagement while driving (path a = −0.053, p = .03). KRD, but not secondary task engagement, was found to mediate (path b = 0.376, p = .02) the relationship between conscientiousness and CNC (path c’ = −0.025, p = .20). Conclusions Using objective measures of driving behavior and a widely used personality construct, these findings present a causal pathway through which personality and risky driving are associated with CNC. Specifically, more conscientious teenage drivers engaged in fewer risky driving maneuvers, suffered fewer CNC. Practical Applications Part of the variability in crash-risk observed among newly licensed teenage drivers can be explained by personality. Parents and driving instructors may take teenage drivers’ personality into account when providing guidance, and establishing norms and expectations about driving. PMID:26403906

Conscientious personality and young drivers' crash risk.

PubMed

Ehsani, Johnathon P; Li, Kaigang; Simons-Morton, Bruce G; Fox Tree-McGrath, Cheyenne; Perlus, Jessamyn G; O'Brien, Fearghal; Klauer, Sheila G

2015-09-01

Personality characteristics are associated with many risk behaviors. However, the relationship between personality traits, risky driving behavior, and crash risk is poorly understood. The purpose of this study was to examine the association between personality, risky driving behavior, and crashes and near-crashes, using naturalistic driving research methods. Participants' driving exposure, kinematic risky driving (KRD), high-risk secondary task engagement, and the frequency of crashes and near-crashes (CNC) were assessed over the first 18months of licensure using naturalistic driving methods. A personality survey (NEO-Five Factor Inventory) was administered at baseline. The association between personality characteristics, KRD rate, secondary task engagement rate, and CNC rate was estimated using a linear regression model. Mediation analysis was conducted to examine if participants' KRD rate or secondary task engagement rate mediated the relationship between personality and CNC. Data were collected as part of the Naturalistic Teen Driving Study. Conscientiousness was marginally negatively associated with CNC (path c=-0.034, p=.09) and both potential mediators KRD (path a=-0.040, p=.09) and secondary task engagement while driving (path a=-0.053, p=.03). KRD, but not secondary task engagement, was found to mediate (path b=0.376, p=.02) the relationship between conscientiousness and CNC (path c'=-0.025, p=.20). Using objective measures of driving behavior and a widely used personality construct, these findings present a causal pathway through which personality and risky driving are associated with CNC. Specifically, more conscientious teenage drivers engaged in fewer risky driving maneuvers, and suffered fewer CNC. Part of the variability in crash risk observed among newly licensed teenage drivers can be explained by personality. Parents and driving instructors may take teenage drivers' personality into account when providing guidance, and establishing norms and expectations about driving. Published by Elsevier Ltd.

Novel hydrophilic nanostructured microtexture on direct metal laser sintered Ti-6Al-4V surfaces enhances osteoblast response in vitro and osseointegration in a rabbit model.

PubMed

Hyzy, Sharon L; Cheng, Alice; Cohen, David J; Yatzkaier, Gustavo; Whitehead, Alexander J; Clohessy, Ryan M; Gittens, Rolando A; Boyan, Barbara D; Schwartz, Zvi

2016-08-01

The purpose of this study was to compare the biological effects in vivo of hierarchical surface roughness on laser sintered titanium-aluminum-vanadium (Ti-6Al-4V) implants to those of conventionally machined implants on osteoblast response in vitro and osseointegration. Laser sintered disks were fabricated to have micro-/nano-roughness and wettability. Control disks were computer numerical control (CNC) milled and then polished to be smooth (CNC-M). Laser sintered disks were polished smooth (LST-M), grit blasted (LST-B), or blasted and acid etched (LST-BE). LST-BE implants or implants manufactured by CNC milling and grit blasted (CNC-B) were implanted in the femurs of male New Zealand white rabbits. Most osteoblast differentiation markers and local factors were enhanced on rough LST-B and LST-BE surfaces in comparison to smooth CNC-M or LST-M surfaces for MG63 and normal human osteoblast cells. To determine if LST-BE implants were osteogenic in vivo, we compared them to implant surfaces used clinically. LST-BE implants had a unique surface with combined micro-/nano-roughness and higher wettability than conventional CNC-B implants. Histomorphometric analysis demonstrated a significant improvement in cortical bone-implant contact of LST-BE implants compared to CNC-B implants after 3 and 6 weeks. However, mechanical testing revealed no differences between implant pullout forces at those time points. LST surfaces enhanced osteoblast differentiation and production of local factors in vitro and improved the osseointegration process in vivo. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2086-2098, 2016. © 2016 Wiley Periodicals, Inc.

An Essential Role of Variant Histone H3.3 for Ectomesenchyme Potential of the Cranial Neural Crest

PubMed Central

Cox, Samuel G.; Kim, Hyunjung; Garnett, Aaron Timothy; Medeiros, Daniel Meulemans; An, Woojin; Crump, J. Gage

2012-01-01

The neural crest (NC) is a vertebrate-specific cell population that exhibits remarkable multipotency. Although derived from the neural plate border (NPB) ectoderm, cranial NC (CNC) cells contribute not only to the peripheral nervous system but also to the ectomesenchymal precursors of the head skeleton. To date, the developmental basis for such broad potential has remained elusive. Here, we show that the replacement histone H3.3 is essential during early CNC development for these cells to generate ectomesenchyme and head pigment precursors. In a forward genetic screen in zebrafish, we identified a dominant D123N mutation in h3f3a, one of five zebrafish variant histone H3.3 genes, that eliminates the CNC–derived head skeleton and a subset of pigment cells yet leaves other CNC derivatives and trunk NC intact. Analyses of nucleosome assembly indicate that mutant D123N H3.3 interferes with H3.3 nucleosomal incorporation by forming aberrant H3 homodimers. Consistent with CNC defects arising from insufficient H3.3 incorporation into chromatin, supplying exogenous wild-type H3.3 rescues head skeletal development in mutants. Surprisingly, embryo-wide expression of dominant mutant H3.3 had little effect on embryonic development outside CNC, indicating an unexpectedly specific sensitivity of CNC to defects in H3.3 incorporation. Whereas previous studies had implicated H3.3 in large-scale histone replacement events that generate totipotency during germ line development, our work has revealed an additional role of H3.3 in the broad potential of the ectoderm-derived CNC, including the ability to make the mesoderm-like ectomesenchymal precursors of the head skeleton. PMID:23028350

A binary catalyst system of a cationic Ru-CNC pincer complex with an alkali metal salt for selective hydroboration of carbon dioxide.

PubMed

Ng, Chee Koon; Wu, Jie; Hor, T S Andy; Luo, He-Kuan

2016-09-27

Binary catalyst systems comprising a cationic Ru-CNC pincer complex and an alkali metal salt were developed for selective hydroboration of CO 2 utilizing pinacolborane at r.t. and 1 atm CO 2 , with the combination of [Ru(CNC Bn )(CO) 2 (H)][PF 6 ] and KOCO 2 t Bu producing formoxyborane in 76% yield. A bicyclic catalytic mechanism was proposed and discussed.

Design of Multi-Order Diffractive THz Lenses

DTIC Science & Technology

2012-09-23

surface. This makes the fabrication process easier and more accurate, thereby improving optical quality. A CNC lathe can be used to carve the lens out...for low-end THz operation (200-800 GHz). The lens was fabricated in Teflon with a small CNC lathe and can be seen in Fig. 3. With only 4 zones...excellent THz transparency and is readily available. Once the CNC turning was complete, the lens was separated from its substrate with a band-saw and

Bull’s-Eye Structure with a Sub-Wavelength Circular Aperture

DTIC Science & Technology

2013-08-30

experimentation. Bull’s-eye structures were fabricated with high precision using a CNC lathe machine and a thermal evaporator. Then, quality of...periodic grooves in the 3-mm-wavelength bull’s-eye structure were created with a CNC lathe on a Teflon or high-density polyethylene (HDPE) substrate... CNC lathe . Figure 26 (far right) shows the cross section of the bull’s-eye structure with six periodic grooves. By clicking on “Preferences” in

DIMP: an interoperable solution for software integration and product data exchange

NASA Astrophysics Data System (ADS)

Wang, Xi Vincent; Xu, Xun William

2012-08-01

Today, globalisation has become one of the main trends of manufacturing business that has led to a world-wide decentralisation of resources amongst not only individual departments within one company but also business partners. However, despite the development and improvement in the last few decades, difficulties in information exchange and sharing still exist in heterogeneous applications environments. This article is divided into two parts. In the first part, related research work and integrating solutions are reviewed and discussed. The second part introduces a collaborative environment called distributed interoperable manufacturing platform, which is based on a module-based, service-oriented architecture (SOA). In the platform, the STEP-NC data model is used to facilitate data-exchange among heterogeneous CAD/CAM/CNC systems.

Chitosan nanoparticles/cellulose nanocrystals nanocomposites as a carrier system for the controlled release of repaglinide.

PubMed

Abo-Elseoud, Wafaa S; Hassan, Mohammad L; Sabaa, Magdy W; Basha, Mona; Hassan, Enas A; Fadel, Shaimaa M

2018-05-01

The aim of the present work was to study the use of cellulose nanocrystals (CNC) and chitosan nanoparticles (CHNP) for developing controlled-release drug delivery system of the anti-hyperglycemic drug Repaglinide (RPG). CNC was isolated from palm fruit stalks by sulfuric acid hydrolysis; the dimensions of the isolated nanocrystals were 86-237 nm in length and 5-7 nm in width. Simple and economic method was used for the fabrication of controlled release drug delivery system from CNC and CHNP loaded with RPG drug via ionic gelation of chitosan in the presence of CNC and RPG. The prepared systems showed high drug encapsulation efficiency of about ~98%. Chemical modification of CNC by oxidation to introduce carboxylic groups on their surface (OXCNC) was also carried out for further controlling of RPG release. Particles size analysis showed that the average size of CHNP was about 197 nm while CHNP/CNC/RPG or CHNP/OXCNC/RPG nanoparticles showed average size of 215-310 nm. Compatibility studies by Fourier transform infrared (FTIR) spectroscopy showed no chemical reaction between RPG and the system's components used. By studying the drug release kinetic, all the prepared RPG formulations followed Higuchi model, indicating that the drug released by diffusion through the nanoparticles polymeric matrix. Copyright © 2018 Elsevier B.V. All rights reserved.

Interactions between Lactobacillus sakei and CNC (Staphylococcus xylosus and Kocuria varians) and their influence on proteolytic activity.

PubMed

Tremonte, P; Reale, A; Di Renzo, T; Tipaldi, L; Di Luccia, A; Coppola, R; Sorrentino, E; Succi, M

2010-11-01

To evaluate interactions between Lactobacillus sakei and coagulase negative cocci (CNC) (Staphylococcus xylosus and Kocuria varians) and to investigate the influence of these interactions on their own proteolytic activity. Interactions occurring between strains of Lact. sakei and CNC were assessed by spectrophotometric analysis. The growth of 35 strains of Lact. sakei, used as indicators, was compared to that obtained combining the same strains with growing cells or cell-free supernatants of 20 CNC (18 Staph. xylosus and 2 K. varians). The proteolytic activity expressed by single strains or by their combinations was assessed on sarcoplasmic protein extracts by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The results evidenced that interactions are able to affect not only the growth but also the in vitro proteolytic activity of Lact. sakei and CNC used in combination. A relationship between the presence of interactions among useful strains and the strength of technological characteristics, such as proteolysis, was defined. The study highlighted that CNC are able to stimulate the growth of some Lact. sakei strains. At the same time, this interaction positively influences the proteolytic activity of strains used in combination. Given the importance of proteolysis during the ripening of fermented meats, this phenomenon should be taken into account to select meat starter cultures. © 2010 The Authors. © 2010 The Society for Applied Microbiology.

Harvey Cushing Treated the First Known Patient With Carney Complex

PubMed Central

Tsay, Cynthia J.; Stratakis, Constantine A.; Faucz, Fabio Rueda; London, Edra; Stathopoulou, Chaido; Allgauer, Michael; Quezado, Martha; Dagradi, Terry; Spencer, Dennis D.

2017-01-01

Context: Carney complex (CNC) is a syndrome characterized by hyperplasia of endocrine organs and may present with clinical features of Cushing syndrome and acromegaly due to functional adrenal and pituitary gland tumors. CNC has been linked to mutations in the regulatory subunit of protein kinase A type I-alpha (PRKAR1A) gene. Design: Tissue samples were taken from the hypothalamus or thalamus or tumors of patients with pituitary adenomas seen and operated on by neurosurgeon Harvey Cushing between 1913 and 1932. Following DNA extraction, sequencing for genes of interest was attempted, including PRKAR1A, AIP, USP8, GNAS1, and GPR101, to explore the possibility that these mutations associated with acromegaly, CNC, and Cushing syndrome have been conserved over time. Results: We report a patient described by Dr. Cushing in 1914 with a clinical presentation and postmortem findings suggestive of CNC. Genetic sequencing of the hypothalamus and pituitary adenoma revealed a germline heterozygous p.Arg74His mutation in the PRKAR1A gene, a codon previously described as mutated in CNC, but with a novel amino acid change. Conclusions: This patient is, to our knowledge, the first molecularly confirmed individual with CNC. This case demonstrates the power of modern genetics in studying archived tissues and the importance of recording detailed clinical notes in the diagnosis of disease. PMID:29264456

Synthesis and characterization of cellulose nanocrystals as reinforcing agent in solely palm based polyurethane foam

NASA Astrophysics Data System (ADS)

Septevani, Athanasia Amanda; Annamalai, Pratheep K.; Martin, Darren J.

2017-11-01

The increasing awareness of the environment and the economy of petroleum resources has driven the development of alternative processes and raw materials based on sustainable and renewable biomaterials with excellent properties. This study is aimed to use biologically renewable cellulose nanocrystals (CNC) as reinforcing agent to enhance the properties of polyurethane foams (PUF) based on solely palm-polyol. Rod-like shape cellulose nanocrystals (CNC) was successfully isolated from cotton based resources via strong acid hydrolysis with the average width, length and aspect ratio about 14.7 ± 4.9 nm, 167.7 ± 23.2 nm and 11.4, respectively. The crystallinity of CNC was confirmed by using X-ray diffraction (XRD) and differential scanning calorimetry (DSC) and was found at 82.8% and 83.8%, respectively. This obtained cellulose nanocrystals (CNC) at a loading of 0.4 wt. % was then incorporated via solvent-free sonication method in the model of palm based polyurethane foam. The preliminary results showed that the effect of CNC on the mechanical properties afforded a significant improvement on the compressive strength and modulus without affecting much their tensile strength. The results on thermal stability and thermal transitions were found unchanged whereas the storage modulus revealed substantial improvement with the presence of CNC with almost two fold from 0.7 MPa to 1.3 MPa (˜86 %).

Revalorization of sunflower stalks as novel sources of cellulose nanofibrils and nanocrystals and their effect on wheat gluten bionanocomposite properties.

PubMed

Fortunati, E; Luzi, F; Jiménez, A; Gopakumar, D A; Puglia, D; Thomas, S; Kenny, J M; Chiralt, A; Torre, L

2016-09-20

Novel gluten based bionanocomposites reinforced with cellulose nanofibrils (CNF) and cellulose nanocrystals (CNC) extracted from sunflower stalks by respectively a steam explosion treatment and a hydrolysis procedure, were prepared by casting/evaporation. The extracted cellulose nanomaterials, both CNC and CNF, were embedded in gluten matrix and their effect was investigated. Morphological investigations highlighted that gluten based bionanocomposites showed a homogenous morphology, the absence of visible cellulose nanoreinforcements, and the presence of holes for Gluten_CNF nanocomposites. Gluten_CNF showed a reduction of water vapour permeability coefficients but the values are higher respect to gluten reinforced with CNC. This behaviour could be related to the ability of CNC to increase the tortuous path of gas molecules. Moreover, the results from thermal, mechanical and barrier properties confirmed the strong interactions obtained between CNC and gluten matrix during the process. The study suggested the possibility to re-valorise agricultural wastes with potential applications as reinforcement in polymer matrix bionanocomposites. Copyright © 2016 Elsevier Ltd. All rights reserved.

New multi-site observations of the delta Scuti stars BS and BT Cancri. Results of the STEPHI VII campaign on the Praesepe cluster

NASA Astrophysics Data System (ADS)

Hernandez, M. M.; Michel, E.; Belmonte, J. A.; Jiang, S. Y.; Alvarez, M.; Chevreton, M.; Paparo, M.; Kjeldsen, H.; Bauduin, D.; Fromage, J.; Goupil, M. J.; Li, Z. P.; Liu, Y. Y.; Mangeney, A.; Massacrier, G.; Ringot, O.; Cortes, T. Roca; Servan, B.; Vidal, I.

1998-09-01

New observations of BS and BT Cnc were performed during the STEPHI VII campaign in 1996 February. An overall run of 115 hours of data was collected. Different methods have been used to analyse the time series, bringing the detection of 2 frequencies for BT Cnc and 3 frequencies for BS Cnc above the 99% confidence level. A comparison with the literature reveals that the dominant mode of BT Cnc ( ~ 9.8 c/d) has kept excited over tens of years, while the secondary modes have not been the same all the time. However, during the very last years the two frequencies detected by us have been the only ones noticeably excited in the spectrum.

Electrochemical and morphological studies of ionic polymer metal composites as stress sensors

DOE PAGES

Hong, Wangyujue; Almomani, Abdallah; Montazami, Reza

2016-10-04

Ionic polymer metal composites (IPMCs) are the backbone of a wide range of ionic devices. IPMC mechanoelectric sensors are advanced nanostructured transducers capable of converting mechanical strain into easily detectable electric signal. Such attribute is realized by ion mobilization in and through IPMC nanostructure. In this study we have investigated electrochemical and morphological characteristics of IPMCs by varying the morphology of their metal composite component (conductive network composite (CNC)). We have demonstrated the dependence of electrochemical properties on CNC nanostructure as well as mechanoelectrical performance of IPMC sensors as a function of CNC morphology. Lastly, it is shown that themore » morphology of CNC can be used as a means to improve sensitivity of IPMC sensors by 3–4 folds.« less

Renner-Teller effects in the photoelectron spectra of CNC, CCN, and HCCN.

PubMed

Coudert, Laurent H; Gans, Bérenger; Garcia, Gustavo A; Loison, Jean-Christophe

2018-02-07

The line intensity of photoelectron spectra when either the neutral or cationic species display a Renner-Teller coupling is derived and applied to the modeling of the photoelectron spectra of CNC, CCN, and HCCN. The rovibronic energy levels of these three radicals and of their cations are investigated starting from ab initio results. A model treating simultaneously the bending mode and the overall rotation is developed to deal with the quasilinearity problem in CNC + , CCN + , and HCCN and accounts for the large amplitude nature of their bending mode. This model is extended to treat the Renner-Teller coupling in CNC, CCN, and HCCN + . Based on the derived photoelectron line intensity, the photoelectron spectra of all three molecules are calculated and compared to the experimental ones.

Structure and properties of composite films formed by cellulose nanocrystals and charged latex nanoparticles

NASA Astrophysics Data System (ADS)

Thérien-Aubin, Héloïse; Lukach, Ariella; Pitch, Natalie; Kumacheva, Eugenia

2015-04-01

We report the structural and optical properties of composite films formed from mixed suspensions of cellulose nanocrystals (CNCs) and fluorescent latex nanoparticles (NPs). We explored the effect of NP concentration, size, surface charge, glass transition temperature and film processing conditions on film structure and properties. The chiral nematic order, typical of CNC films, was preserved in films with up to 50 wt% of negatively-charged latex NPs. Composite films were characterized by macroscopically close-to-uniform fluorescence, birefringence, and circular dichroism properties. In contrast, addition of positively charged latex NPs led to gelation of CNC-latex suspensions and disruption of the chiral nematic order in the composite films. Large latex NPs disrupted the chiral nematic order to a larger extend than small NPs. Furthermore, the glass transition of latex NPs had a dramatic effect on the structure of CNC-latex films. Latex particles in the rubbery state were easily incorporated in the ordered CNC matrix and improved the structural integrity of its chiral nematic phase.We report the structural and optical properties of composite films formed from mixed suspensions of cellulose nanocrystals (CNCs) and fluorescent latex nanoparticles (NPs). We explored the effect of NP concentration, size, surface charge, glass transition temperature and film processing conditions on film structure and properties. The chiral nematic order, typical of CNC films, was preserved in films with up to 50 wt% of negatively-charged latex NPs. Composite films were characterized by macroscopically close-to-uniform fluorescence, birefringence, and circular dichroism properties. In contrast, addition of positively charged latex NPs led to gelation of CNC-latex suspensions and disruption of the chiral nematic order in the composite films. Large latex NPs disrupted the chiral nematic order to a larger extend than small NPs. Furthermore, the glass transition of latex NPs had a dramatic effect on the structure of CNC-latex films. Latex particles in the rubbery state were easily incorporated in the ordered CNC matrix and improved the structural integrity of its chiral nematic phase. Electronic supplementary information (ESI) available: Detailed latex synthesis. Additional characterization of the nanoparticles and films. See DOI: 10.1039/c5nr00660k

Frequent phosphodiesterase 11A gene (PDE11A) defects in patients with Carney complex (CNC) caused by PRKAR1A mutations: PDE11A may contribute to adrenal and testicular tumors in CNC as a modifier of the phenotype.

PubMed

Libé, Rossella; Horvath, Anelia; Vezzosi, Delphine; Fratticci, Amato; Coste, Joel; Perlemoine, Karine; Ragazzon, Bruno; Guillaud-Bataille, Marine; Groussin, Lionel; Clauser, Eric; Raffin-Sanson, Marie-Laure; Siegel, Jennifer; Moran, Jason; Drori-Herishanu, Limor; Faucz, Fabio Rueda; Lodish, Maya; Nesterova, Maria; Bertagna, Xavier; Bertherat, Jerome; Stratakis, Constantine A

2011-01-01

Carney complex (CNC) is an autosomal dominant multiple neoplasia, caused mostly by inactivating mutations of the regulatory subunit 1A of the protein kinase A (PRKAR1A). Primary pigmented nodular adrenocortical disease (PPNAD) is the most frequent endocrine manifestation of CNC with a great inter-individual variability. Germline, protein-truncating mutations of phosphodiesterase type 11A (PDE11A) have been described to predispose to a variety of endocrine tumors, including adrenal and testicular tumors. Our objective was to investigate the role of PDE11A as a possible gene modifier of the phenotype in a series of 150 patients with CNC. A higher frequency of PDE11A variants in patients with CNC compared with healthy controls was found (25.3 vs. 6.8%, P < 0.0001). Among CNC patients, those with PPNAD were significantly more frequently carriers of PDE11A variants compared with patients without PPNAD (30.8 vs. 13%, P = 0.025). Furthermore, men with PPNAD were significantly more frequently carriers of PDE11A sequence variants (40.7%) than women with PPNAD (27.3%) (P < 0.001). A higher frequency of PDE11A sequence variants was also found in patients with large-cell calcifying Sertoli cell tumors (LCCSCT) compared with those without LCCSCT (50 vs. 10%, P = 0.0056). PDE11A variants were significantly associated with the copresence of PPNAD and LCCSCT in men: 81 vs. 20%, P < 0.004). The simultaneous inactivation of PRKAR1A and PDE11A by small inhibitory RNA led to an increase in cAMP-regulatory element-mediated transcriptional activity under basal conditions and after stimulation by forskolin. We demonstrate, in a large cohort of CNC patients, a high frequency of PDE11A variants, suggesting that PDE11A is a genetic modifying factor for the development of testicular and adrenal tumors in patients with germline PRKAR1A mutation.

CAD/CAM/CNC.

ERIC Educational Resources Information Center

Domermuth, Dave; And Others

1996-01-01

Includes "Quick Start CNC (computer numerical control) with a Vacuum Filter and Laminated Plastic" (Domermuth); "School and Industry Cooperate for Mutual Benefit" (Buckler); and "CAD (computer-assisted drafting) Careers--What Professionals Have to Say" (Skinner). (JOW)

ADAM13 Induces Cranial Neural Crest by Cleaving Class B Ephrins and Regulating Wnt Signaling

PubMed Central

Wei, Shuo; Xu, Guofeng; Bridges, Lance C.; Williams, Phoebe; White, Judith M.; DeSimone, Douglas W.

2010-01-01

SUMMARY The cranial neural crest (CNC) are multipotent embryonic cells that contribute to craniofacial structures and other cells and tissues of the vertebrate head. During embryogenesis, CNC is induced at the neural plate boundary through the interplay of several major signaling pathways. Here we report that the metalloproteinase activity of ADAM13 is required for early induction of CNC in Xenopus. In both cultured cells and X. tropicalis embryos, membrane-bound Ephrins (Efns) B1 and B2 were identified as substrates for ADAM13. ADAM13 upregulates canonical Wnt signaling and early expression of the transcription factor snail2, whereas EfnB1 inhibits the canonical Wnt pathway and snail2 expression. We propose that by cleaving class B Efns, ADAM13 promotes canonical Wnt signaling and early CNC induction. PMID:20708595

Bionanocomposite films based on polysaccharides from banana peels.

PubMed

Oliveira, Túlio Ítalo S; Rosa, Morsyleide F; Ridout, Michael J; Cross, Kathryn; Brito, Edy S; Silva, Lorena M A; Mazzetto, Selma E; Waldron, Keith W; Azeredo, Henriette M C

2017-08-01

Pectin and cellulose nanocrystals (CNCs) isolated from banana peels were used to prepare films. The effects of a reinforcing phase (CNCs) and a crosslinker (citric acid, CA) on properties of pectin films were studied. Glycerol-plasticized films were prepared by casting, with different CNC contents (0-10wt%), with or without CA. Overall tensile properties were improved by intermediate CNC contents (around 5wt%). The water resistance and water vapor barrier properties were also enhanced by CNC. Evidences were found from Fourier Transform Infrared (FTIR) spectra supporting the occurrence of crosslinking by CA. Additionally, the tensile strength, water resistance and barrier to water vapor were improved by the presence of CA. The 13 C ssNMR spectra indicated that both CA and CNC promoted stiffening of the polymer chains. Copyright © 2017 Elsevier B.V. All rights reserved.

Catalytic Hydrogenation Activity and Electronic Structure Determination of Bis(arylimidazol-2-ylidene)pyridine Cobalt Alkyl and Hydride Complexes

PubMed Central

Yu, Renyuan Pony; Darmon, Jonathan M.; Milsmann, Carsten; Margulieux, Grant W.; E. Stieber, S. Chantal; DeBeer, Serena

2013-01-01

The bis(arylimidazol-2-ylidene)pyridine cobalt methyl complex, (iPrCNC)CoCH3, was evaluated for the catalytic hydrogenation of alkenes. At 22 °C and 4 atm of H2 pressure, (iPrCNC)CoCH3 is an effective pre-catalyst for the hydrogenation of sterically hindered, unactivated alkenes such as trans-methylstilbene, 1-methyl-1-cyclohexene and 2,3-dimethyl-2-butene, representing one of the most active cobalt hydrogenation catalysts reported to date. Preparation of the cobalt hydride complex, (iPrCNC)CoH was accomplished by hydrogenation of (iPrCNC)CoCH3. Over the course of 3 hours at 22 °C, migration of the metal-hydride to the 4-position of the pyridine ring yielded (4-H2-iPrCNC)CoN2. Similar alkyl migration was observed upon treatment of (iPrCNC)CoH with 1,1-diphenylethylene. This reactivity raised the question as to whether this class of chelate is redoxactive, engaging in radical chemistry with the cobalt center. A combination of structural, spectroscopic and computational studies was conducted and provided definitive evidence for bis(arylimidazol-2-ylidene)pyridine radicals in reduced cobalt chemistry. Spin density calculations established that the radicals were localized on the pyridine ring, accounting for the observed reactivity and suggest a wide family of pyridine-based pincers may also be redox active. PMID:23968297

Cadherin-11 Mediates Contact Inhibition of Locomotion during Xenopus Neural Crest Cell Migration

PubMed Central

Becker, Sarah F. S.; Mayor, Roberto; Kashef, Jubin

2013-01-01

Collective cell migration is an essential feature both in embryonic development and cancer progression. The molecular mechanisms of these coordinated directional cell movements still need to be elucidated. The migration of cranial neural crest (CNC) cells during embryogenesis is an excellent model for collective cell migration in vivo. These highly motile and multipotent cells migrate directionally on defined routes throughout the embryo. Interestingly, local cell-cell interactions seem to be the key force for directionality. CNC cells can change their migration direction by a repulsive cell response called contact inhibition of locomotion (CIL). Cell protrusions collapse upon homotypic cell-cell contact and internal repolarization leads to formation of new protrusions toward cell-free regions. Wnt/PCP signaling was shown to mediate activation of small RhoGTPase RhoA and inhibition of cell protrusions at the contact side. However, the mechanism how a cell recognizes the contact is poorly understood. Here, we demonstrate that Xenopus cadherin-11 (Xcad-11) mediated cell-cell adhesion is necessary in CIL for directional and collective migration of CNC cells. Reduction of Xcad-11 adhesive function resulted in higher invasiveness of CNC due to loss of CIL. Additionally, transplantation analyses revealed that CNC migratory behaviour in vivo is non-directional and incomplete when Xcad-11 adhesive function is impaired. Blocking Wnt/PCP signaling led to similar results underlining the importance of Xcad-11 in the mechanism of CIL and directional migration of CNC. PMID:24392028

Catalytic hydrogenation activity and electronic structure determination of bis(arylimidazol-2-ylidene)pyridine cobalt alkyl and hydride complexes.

PubMed

Yu, Renyuan Pony; Darmon, Jonathan M; Milsmann, Carsten; Margulieux, Grant W; Stieber, S Chantal E; DeBeer, Serena; Chirik, Paul J

2013-09-04

The bis(arylimidazol-2-ylidene)pyridine cobalt methyl complex, ((iPr)CNC)CoCH3, was evaluated for the catalytic hydrogenation of alkenes. At 22 °C and 4 atm of H2 pressure, ((iPr)CNC)CoCH3 is an effective precatalyst for the hydrogenation of sterically hindered, unactivated alkenes such as trans-methylstilbene, 1-methyl-1-cyclohexene, and 2,3-dimethyl-2-butene, representing one of the most active cobalt hydrogenation catalysts reported to date. Preparation of the cobalt hydride complex, ((iPr)CNC)CoH, was accomplished by hydrogenation of ((iPr)CNC)CoCH3. Over the course of 3 h at 22 °C, migration of the metal hydride to the 4-position of the pyridine ring yielded (4-H2-(iPr)CNC)CoN2. Similar alkyl migration was observed upon treatment of ((iPr)CNC)CoH with 1,1-diphenylethylene. This reactivity raised the question as to whether this class of chelate is redox-active, engaging in radical chemistry with the cobalt center. A combination of structural, spectroscopic, and computational studies was conducted and provided definitive evidence for bis(arylimidazol-2-ylidene)pyridine radicals in reduced cobalt chemistry. Spin density calculations established that the radicals were localized on the pyridine ring, accounting for the observed reactivity, and suggest that a wide family of pyridine-based pincers may also be redox-active.

Reproductive disturbances in multiple neuroendocrine tumor syndromes.

PubMed

Lytras, Aristides; Tolis, George

2009-12-01

In the context of multiple neuroendocrine tumor syndromes, reproductive abnormalities may occur via a number of different mechanisms, such as hyperprolactinemia, increased GH/IGF-1 levels, hypogonadotropic hypogonadism, hypercortisolism, hyperandrogenism, hyperthyroidism, gonadotropin hypersecretion, as well as, tumorigenesis or functional disturbances in gonads or other reproductive organs. Precocious puberty and/or male feminization is a feature of McCune-Albright syndrome (MAS), neurofibromatosis type 1 (NF1), Carney complex (CNC), and Peutz-Jeghers syndrome (PJS), while sperm maturation and ovulation defects have been described in MAS and CNC. Although tumorigenesis of reproductive organs due to a multiple neuroendocrine tumor syndrome is very rare, certain lesions are characteristic and very unusual in the general population. Awareness leading to their recognition is important especially when other endocrine abnormalities coexist, as occasionally they may even be the first manifestation of a syndrome. Lesions such as certain types of ovarian cysts (MAS, CNC), pseudogynecomastia due to neurofibromas of the nipple-areola area (NF1), breast disease (CNC and Cowden disease (CD)), cysts and 'hypernephroid' tumors of the epididymis or bilateral papillary cystadenomas (mesosalpinx cysts) and endometrioid cystadenomas of the broad ligament (von Hippel-Lindau disease), testicular Sertoli calcifying tumors (CNC, PJS) monolateral or bilateral macroochidism and microlithiasis (MAS) may offer diagnostic clues. In addition, multiple neuroendocrine tumor syndromes may be complicated by reproductive malignancies including ovarian cancer in CNC, breast and endometrial cancer in CD, breast malignancies in NF1, and malignant sex-cord stromal tumors in PJS.

Development of a QFD-based expert system for CNC turning centre selection

NASA Astrophysics Data System (ADS)

Prasad, Kanika; Chakraborty, Shankar

2015-12-01

Computer numerical control (CNC) machine tools are automated devices capable of generating complicated and intricate product shapes in shorter time. Selection of the best CNC machine tool is a critical, complex and time-consuming task due to availability of a wide range of alternatives and conflicting nature of several evaluation criteria. Although, the past researchers had attempted to select the appropriate machining centres using different knowledge-based systems, mathematical models and multi-criteria decision-making methods, none of those approaches has given due importance to the voice of customers. The aforesaid limitation can be overcome using quality function deployment (QFD) technique, which is a systematic approach for integrating customers' needs and designing the product to meet those needs first time and every time. In this paper, the adopted QFD-based methodology helps in selecting CNC turning centres for a manufacturing organization, providing due importance to the voice of customers to meet their requirements. An expert system based on QFD technique is developed in Visual BASIC 6.0 to automate the CNC turning centre selection procedure for different production plans. Three illustrative examples are demonstrated to explain the real-time applicability of the developed expert system.

Linear positioning laser calibration setup of CNC machine tools

NASA Astrophysics Data System (ADS)

Sui, Xiulin; Yang, Congjing

2002-10-01

The linear positioning laser calibration setup of CNC machine tools is capable of executing machine tool laser calibraiotn and backlash compensation. Using this setup, hole locations on CNC machien tools will be correct and machien tool geometry will be evaluated and adjusted. Machien tool laser calibration and backlash compensation is a simple and straightforward process. First the setup is to 'find' the stroke limits of the axis. Then the laser head is then brought into correct alignment. Second is to move the machine axis to the other extreme, the laser head is now aligned, using rotation and elevation adjustments. Finally the machine is moved to the start position and final alignment is verified. The stroke of the machine, and the machine compensation interval dictate the amount of data required for each axis. These factors determine the amount of time required for a through compensation of the linear positioning accuracy. The Laser Calibrator System monitors the material temperature and the air density; this takes into consideration machine thermal growth and laser beam frequency. This linear positioning laser calibration setup can be used on CNC machine tools, CNC lathes, horizontal centers and vertical machining centers.

Empowering open systems through cross-platform interoperability

NASA Astrophysics Data System (ADS)

Lyke, James C.

2014-06-01

Most of the motivations for open systems lie in the expectation of interoperability, sometimes referred to as "plug-and-play". Nothing in the notion of "open-ness", however, guarantees this outcome, which makes the increased interest in open architecture more perplexing. In this paper, we explore certain themes of open architecture. We introduce the concept of "windows of interoperability", which can be used to align disparate portions of architecture. Such "windows of interoperability", which concentrate on a reduced set of protocol and interface features, might achieve many of the broader purposes assigned as benefits in open architecture. Since it is possible to engineer proprietary systems that interoperate effectively, this nuanced definition of interoperability may in fact be a more important concept to understand and nurture for effective systems engineering and maintenance.

Effect of a gelatin-based edible coating containing cellulose nanocrystals (CNC) on the quality and nutrient retention of fresh strawberries during storage

NASA Astrophysics Data System (ADS)

Fakhouri, F. M.; Casari, A. C. A.; Mariano, M.; Yamashita, F.; Innocnentini Mei, L. H.; Soldi, V.; Martelli, S. M.

2014-08-01

Strawberry is a non-climacteric fruit with a very short postharvest shelf-life. Loss of quality in this fruit is mostly due to its relatively high metabolic activity and sensitivity to fungal decay, meanly grey mold (Botrytis cinerea). In this study, the ability of gelatin coatings containing cellulose nanocrystals (CNC) to extend the shelf-life of strawberry fruit (Fragaria ananassa) over 8 days were studied. The filmogenic solution was obtained by the hydration of 5 g of gelatin (GEL) in 100 mL of distillated water containing different amounts of CNC dispersion (10 mg CNC/g of GEL or 50 mg of CNC/g of GEL) for 1 hour at room temperature. After this period, the solution was heated to 70 °C and maintained at this temperature for 10 minutes. The plasticizer (glycerol) (10g/100g of the GEL) was then added with constant, gentle stirring in order to avoid forming air bubbles and also to avoid gelatin denaturation until complete homogenization. Strawberries (purchased at the local market) were immersed in the filmogenic solution for 1 minute and after coated were dried at 15 °C by 24 hours. The strawberries were then kept under refrigeration and characterized in terms of their properties (weight loss, ascorbic acid content, titratable acidity, water content). The results have shown that samples covered with GEL/CNC had a significant improvement in its shelf- life. For instance, for the control sample (without coating) the weight loss after 8 days of storage was around 65%, while covered samples loss in the range of 31-36%. Edible coating was also effective in the retention of ascorbic acid (AA) in the strawberries, while control sample presented a fast decay in the AA content, covered samples showed a slow decay in the AA concentration. Moreover, the use of GEL/CNC edible coating had an antimicrobial effect in the fruits.

Protocadherin PAPC is expressed in the CNC and can compensate for the loss of PCNS.

PubMed

Schneider, Martina; Huang, Chaolie; Becker, Sarah F S; Gradl, Dietmar; Wedlich, Doris

2014-02-01

Protocadherins represent the biggest subgroup within the cadherin superfamily of transmembrane glycoproteins. In contrast to classical type I cadherins, protocadherins in general exhibit only moderate adhesive activity. During embryogenesis, they are involved in cell signaling and regulate diverse morphogenetic processes, including morphogenetic movements during gastrulation and neural crest migration. The two protocadherins paraxial protocadherin (PAPC) and axial protocadherin (AXPC) are indispensable for proper gastrulation movements in Xenopus and zebrafish. The closest relative PCNS instead, is required for neural crest and somite formation. Here, we show that cranial neural crest (CNC) cells in addition to PCNS express PAPC, but not AXPC. Overexpression of PAPC resulted in comparable migration defects as knockdown of PCNS. Moreover, reconstitution experiments revealed that PAPC is able to replace PCNS in CNC cells, indicating that both protocadherins can regulate CNC migration. Copyright © 2013 Wiley Periodicals, Inc.

Poly(glycerol sebacate urethane)-cellulose nanocomposites with water-active shape-memory effects.

PubMed

Wu, Tongfei; Frydrych, Martin; O'Kelly, Kevin; Chen, Biqiong

2014-07-14

Biodegradable and biocompatible materials with shape-memory effects (SMEs) are attractive for use as minimally invasive medical devices. Nanocomposites with SMEs were prepared from biodegradable poly(glycerol sebacate urethane) (PGSU) and renewable cellulose nanocrystals (CNCs). The effects of CNC content on the structure, water absorption, and mechanical properties of the PGSU were studied. The water-responsive mechanically adaptive properties and shape-memory performance of PGSU-CNC nanocomposites were observed, which are dependent on the content of CNCs. The PGSU-CNC nanocomposite containing 23.2 vol % CNCs exhibited the best SMEs among the nanocomposites investigated, with the stable shape fixing and shape recovery ratios being 98 and 99%, respectively, attributable to the formation of a hydrophilic, yet strong, CNC network in the elastomeric matrix. In vitro degradation profiles of the nanocomposites were assessed with and without the presence of an enzyme.

Simple citric acid-catalyzed surface esterification of cellulose nanocrystals.

PubMed

Ávila Ramírez, Jhon Alejandro; Fortunati, Elena; Kenny, José María; Torre, Luigi; Foresti, María Laura

2017-02-10

A simple straightforward route for the surface esterification of cellulose nanocrystals (CNC) is herein proposed. CNC obtained from microcrystalline cellulose were acetylated using as catalyst citric acid, a α-hydroxy acid present in citrus fruits and industrially produced by certain molds in sucrose or glucose-containing medium. No additional solvent was added to the system; instead, the acylant (acetic anhydride) was used in sufficient excess to allow CNC dispersion and proper suspension agitation. By tuning the catalyst load, CNC with two different degree of substitution (i.e. DS=0.18 and 0.34) were obtained. Acetylated cellulose nanocrystals were characterized in terms of chemical structure, crystallinity, morphology, thermal decomposition and dispersion in a non-polar solvent. Results illustrated for the first time the suitability of the protocol proposed for the simple surface acetylation of cellulose nanocrystals. Copyright © 2016 Elsevier Ltd. All rights reserved.

An iterative learning control method with application for CNC machine tools

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

Kim, D.I.; Kim, S.

1996-01-01

A proportional, integral, and derivative (PID) type iterative learning controller is proposed for precise tracking control of industrial robots and computer numerical controller (CNC) machine tools performing repetitive tasks. The convergence of the output error by the proposed learning controller is guaranteed under a certain condition even when the system parameters are not known exactly and unknown external disturbances exist. As the proposed learning controller is repeatedly applied to the industrial robot or the CNC machine tool with the path-dependent repetitive task, the distance difference between the desired path and the actual tracked or machined path, which is one ofmore » the most significant factors in the evaluation of control performance, is progressively reduced. The experimental results demonstrate that the proposed learning controller can improve machining accuracy when the CNC machine tool performs repetitive machining tasks.« less

Multi-objective optimization model of CNC machining to minimize processing time and environmental impact

NASA Astrophysics Data System (ADS)

Hamada, Aulia; Rosyidi, Cucuk Nur; Jauhari, Wakhid Ahmad

2017-11-01

Minimizing processing time in a production system can increase the efficiency of a manufacturing company. Processing time are influenced by application of modern technology and machining parameter. Application of modern technology can be apply by use of CNC machining, one of the machining process can be done with a CNC machining is turning. However, the machining parameters not only affect the processing time but also affect the environmental impact. Hence, optimization model is needed to optimize the machining parameters to minimize the processing time and environmental impact. This research developed a multi-objective optimization to minimize the processing time and environmental impact in CNC turning process which will result in optimal decision variables of cutting speed and feed rate. Environmental impact is converted from environmental burden through the use of eco-indicator 99. The model were solved by using OptQuest optimization software from Oracle Crystal Ball.

Preparation of raspberry-like γ-Fe2O3/crackled nitrogen-doped carbon capsules and their application as supports to improve catalytic activity.

PubMed

Zhang, Junshuai; Yao, Tongjie; Zhang, Hui; Zhang, Xiao; Wu, Jie

2016-11-10

In this manuscript, we have introduced a novel method to improve the catalytic activity of metal nanoparticles via optimizing the support structure. To this end, raspberry-like γ-Fe 2 O 3 /crackled nitrogen-doped carbon (CNC) capsules were prepared by a two-step method. Compared with traditional magnetic capsules, in γ-Fe 2 O 3 /CNC capsules, the γ-Fe 2 O 3 nanoparticles were embedded in a CNC shell; therefore, they neither occupied the anchoring sites for metal nanoparticles nor came into contact with them, which was beneficial for increasing the metal nanoparticle loading. Numerous tiny cracks appeared on the porous CNC shell, which effectively improved the mass diffusion and transport in catalytic reactions. Additionally, the coordination interaction could be generated between the precursor metal ions and doped-nitrogen atoms in the capsule shell. With the help of these structural merits, γ-Fe 2 O 3 /CNC capsules were ideal supports for Pd nanoparticles, because they were beneficial for improving the Pd loading, reducing the nanoparticle size, increasing their dispersity and maximizing the catalytic performance of Pd nanoparticles anchored on the inner shell surface. As expected, γ-Fe 2 O 3 /CNC@Pd catalysts exhibited a dramatically enhanced catalytic activity towards hydrophilic 4-nitrophenol and hydrophobic nitrobenzene. The reaction rate constant k was compared with recent work and the corresponding reference samples. Moreover, they could be easily recycled by using a magnet and reused without an obvious loss of catalytic activity.

Keep Your Eyes on the Road: Young Driver Crash Risk Increases According to Duration of Distraction

PubMed Central

Simons-Morton, Bruce; Guo, Feng; Klauer, Sheila G; Ehsani, Johnathon P; Pradhan, Anuj K

2014-01-01

Purpose Secondary task engagement that distracts the driver is a contributing factor to motor vehicle crashes among adults. However, the association between eye glance duration and crash risk with novice teenage drivers has not been determined. Methods Vehicles of 42 newly-licensed teenage drivers were instrumented with cameras, accelerometers, GPS, and other devices. Data were collected continuously for 18 months. Crashes and near crashes (CNCs) were identified by examining highly elevated gravitational force events. Video footage of the 6 seconds prior to each CNC and randomly sampled non-CNC road segments were coded for the duration of eye glances off the forward roadway and the presence of secondary task engagement. The likelihood (odds ratios) of CNC due to eye glance behavior was calculated by comparing the prevalence of secondary task engagement and duration of eyes off road prior to CNC with the prevalence and duration of eyes off road during non-CNC road segments. Results Crash risk increased with the duration of single longest glance during all secondary tasks (OR=3.8 for >2s) and wireless secondary task engagement (OR=5.5 for >2s). Single longest glance provided a more consistent estimate of crash risk than total time eyes off the forward roadway. Conclusions Eyes glances away from forward roadway involving secondary tasks increased the likelihood of CNC. The longer the duration of eye glance away from the road the greater the risk, regardless of type of secondary task. Education and policy discouraging secondary task engagement, particularly for prolonged periods, is warranted. PMID:24759443

Developing Performance Based Requirements for Open Architecture Design

DTIC Science & Technology

2006-04-30

Åèìáëáíáçå= oÉëÉ~êÅÜ=póãéçëáìã= DEVELOPING PERFORMANCE BASED REQUIREMENTS FOR OPEN ARCHITECTURE DESIGN Published: 30 April 2006 by Brad Naegle...for Open Architecture Design 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f...Ñçê=áåÑçêãÉÇ=ÅÜ~åÖÉ======= = - 174 - = = Developing Performance Based Requirements for Open Architecture Design Presenter: Brad Naegle, Lieutenant

Achieving Better Buying Power through Acquisition of Open Architecture Software Systems for Web-Based and Mobile Devices

DTIC Science & Technology

2015-05-01

Achieving Better Buying Power through Acquisition of Open Architecture Software Systems for Web-Based and Mobile Devices Walt Scacchi and Thomas...2015 to 00-00-2015 4. TITLE AND SUBTITLE Achieving Better Buying Power through Acquisition of Open Architecture Software Systems for Web-Based and...architecture (OA) software systems  Emerging challenges in achieving Better Buying Power (BBP) via OA software systems for Web- based and Mobile devices

Seminar for High School Students “Practice on Manufacturing Technology by Advanced Machine Tools”

NASA Astrophysics Data System (ADS)

Marui, Etsuo; Yamawaki, Masao; Taga, Yuken; Omoto, Ken'ichi; Miyaji, Reiji; Ogura, Takahiro; Tsubata, Yoko; Sakai, Toshimasa

The seminar ‘Practice on Manufacturing Technology by Advanced Machine Tools’ for high school students was held at the supporting center for technology education of Gifu University, under the sponsorship of the Japan Society of Mechanical Engineers. This seminar was held, hoping that many students become interested in manufacturing through the experience of the seminar. Operating CNC milling machine and CNC wire-cut electric discharge machine, they made original nameplates. Participants made the program to control CNC machine tools themselves. In this report, some valuable results obtained through such experience are explained.

When does an old nova become a dwarf nova? Kinematics and age of the nova shell of the dwarf nova AT Cancri

NASA Astrophysics Data System (ADS)

Shara, Michael M.; Drissen, Laurent; Martin, Thomas; Alarie, Alexandre; Stephenson, F. Richard

2017-02-01

The Z Cam-type dwarf nova AT Cancri (AT Cnc) displays a classical nova (CN) shell, demonstrating that mass transfer in cataclysmic binaries decreases substantially after a CN eruption. The hibernation scenario of cataclysmic binaries predicts such a decrease, on a time-scale of a few centuries. In order to measure the time since AT Cnc's last CN eruption, we have measured the radial velocities of a hundred clumps in its ejecta with SITELLE, Canada-France-Hawaii Telescope's recently commissioned imaging Fourier transform spectrometer. These range from -455 to +490 km s-1. Coupled with the known distance to AT Cnc of 460 pc, the size of AT Cnc's shell, and a simple model of nova ejecta deceleration, we determine that the last CN eruption of this system occurred 330_{-90}^{+135} yr ago. This is the most rapid transition from a high mass-transfer rate, nova-like variable to a low mass-transfer rate, dwarf nova yet measured, and in accord with the hibernation scenario of cataclysmic binaries. We conclude by noting the similarity in the deduced outburst date (within a century of 1686 CE) of AT Cnc to a `guest star' reported in the constellation Cancer by Korean observers in 1645 CE.

Dental glass ionomer cement reinforced by cellulose microfibers and cellulose nanocrystals.

PubMed

Silva, Rafael M; Pereira, Fabiano V; Mota, Felipe A P; Watanabe, Evandro; Soares, Suelleng M C S; Santos, Maria Helena

2016-01-01

The aim of this work was to evaluate if the addition of cellulose microfibers (CmF) or cellulose nanocrystals (CNC) would improve the mechanical properties of a commercial dental glass ionomer cement (GIC). Different amounts of CmF and CNC were previously prepared and then added to reinforce the GIC matrix while it was being manipulated. Test specimens with various concentrations of CmF or CNC in their total masses were fabricated and submitted to mechanical tests (to evaluate their compressive and diametral tensile strength,modulus, surface microhardness and wear resistance) and characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The incorporation of CmF in the GIC matrix did not greatly improve the mechanical properties of GIC. However, the addition of a small amount of CNC in the GIC led to significant improvements in all of the mechanical properties evaluated: compressive strength (increased up to 110% compared with the control group), elastic modulus increased by 161%, diametral tensile strength increased by 53%, and the mass loss decreased from 10.95 to 3.87%. Because the composites presented a considerable increase in mechanical properties, the modification of the conventional GIC with CNC can represent a new and promising dental restorative material.

GSK3 and Polo-like kinase regulate ADAM13 function during cranial neural crest cell migration

PubMed Central

Abbruzzese, Genevieve; Cousin, Hélène; Salicioni, Ana Maria; Alfandari, Dominique

2014-01-01

ADAMs are cell surface metalloproteases that control multiple biological processes by cleaving signaling and adhesion molecules. ADAM13 controls cranial neural crest (CNC) cell migration both by cleaving cadherin-11 to release a promigratory extracellular fragment and by controlling expression of multiple genes via its cytoplasmic domain. The latter activity is regulated by γ-secretase cleavage and the translocation of the cytoplasmic domain into the nucleus. One of the genes regulated by ADAM13, the protease calpain8, is essential for CNC migration. Although the nuclear function of ADAM13 is evolutionarily conserved, it is unclear whether the transcriptional regulation is also performed by other ADAMs and how this process may be regulated. We show that ADAM13 function to promote CNC migration is regulated by two phosphorylation events involving GSK3 and Polo-like kinase (Plk). We further show that inhibition of either kinase blocks CNC migration and that the respective phosphomimetic forms of ADAM13 can rescue these inhibitions. However, these phosphorylations are not required for ADAM13 proteolysis of its substrates, γ-secretase cleavage, or nuclear translocation of its cytoplasmic domain. Of significance, migration of the CNC can be restored in the absence of Plk phosphorylation by expression of calpain-8a, pointing to impaired nuclear activity of ADAM13. PMID:25298404

Cooperative ordering and kinetics of cellulose nanocrystal alignment in a magnetic field

DOE PAGES

De France, Kevin J.; Yager, Kevin G.; Hoare, Todd; ...

2016-07-13

Cellulose nanocrystals (CNCs) are emerging nanomaterials that form chiral nematic liquid crystals above a critical concentration (C*) and additionally orient within electromagnetic fields. The control over CNC alignment is significant for materials processing and end use; to date, magnetic alignment has been demonstrated using only strong fields over extended or arbitrary time scales. This work investigates the effects of comparatively weak magnetic fields (0–1.2 T) and CNC concentration (1.65–8.25 wt %) on the kinetics and degree of CNC ordering using small-angle X-ray scattering. Interparticle spacing, correlation length, and orientation order parameters (η and S) increased with time and field strengthmore » following a sigmoidal profile. In a 1.2 T magnetic field for CNC suspensions above C*, partial alignment occurred in under 2 min followed by slower cooperative ordering to achieve nearly perfect alignment in under 200 min (S = –0.499 where S = –0.5 indicates perfect antialignment). At 0.56 T, nearly perfect alignment was also achieved, yet the ordering was 36% slower. Outside of a magnetic field, the order parameter plateaued at 52% alignment (S = –0.26) after 5 h, showcasing the drastic effects of relatively weak magnetic fields on CNC alignment. For suspensions below C*, no magnetic alignment was detected.« less

Lorentz invariance violation and charge (non)conservation: A general theoretical frame for extensions of the Maxwell equations

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

Laemmerzahl, Claus; Macias, Alfredo; Mueller, Holger

2005-01-15

All quantum gravity approaches lead to small modifications in the standard laws of physics which in most cases lead to violations of Lorentz invariance. One particular example is the extended standard model (SME). Here, a general phenomenological approach for extensions of the Maxwell equations is presented which turns out to be more general than the SME and which covers charge nonconservation (CNC), too. The new Lorentz invariance violating terms cannot be probed by optical experiments but need, instead, the exploration of the electromagnetic field created by a point charge or a magnetic dipole. Some scalar tensor theories and higher dimensionalmore » brane theories predict CNC in four dimensions and some models violating special relativity have been shown to be connected with CNC. Its relation to the Einstein Equivalence Principle has been discussed. Because of this upcoming interest, the experimental status of electric charge conservation is reviewed. Up to now there seem to exist no unique tests of charge conservation. CNC is related to the precession of polarization, to a modification of the 1/r-Coulomb potential, and to a time dependence of the fine structure constant. This gives the opportunity to describe a dedicated search for CNC.« less

Comprehensive reliability allocation method for CNC lathes based on cubic transformed functions of failure mode and effects analysis

NASA Astrophysics Data System (ADS)

Yang, Zhou; Zhu, Yunpeng; Ren, Hongrui; Zhang, Yimin

2015-03-01

Reliability allocation of computerized numerical controlled(CNC) lathes is very important in industry. Traditional allocation methods only focus on high-failure rate components rather than moderate failure rate components, which is not applicable in some conditions. Aiming at solving the problem of CNC lathes reliability allocating, a comprehensive reliability allocation method based on cubic transformed functions of failure modes and effects analysis(FMEA) is presented. Firstly, conventional reliability allocation methods are introduced. Then the limitations of direct combination of comprehensive allocation method with the exponential transformed FMEA method are investigated. Subsequently, a cubic transformed function is established in order to overcome these limitations. Properties of the new transformed functions are discussed by considering the failure severity and the failure occurrence. Designers can choose appropriate transform amplitudes according to their requirements. Finally, a CNC lathe and a spindle system are used as an example to verify the new allocation method. Seven criteria are considered to compare the results of the new method with traditional methods. The allocation results indicate that the new method is more flexible than traditional methods. By employing the new cubic transformed function, the method covers a wider range of problems in CNC reliability allocation without losing the advantages of traditional methods.

Transcriptional regulation of xenobiotic detoxification in Drosophila

PubMed Central

Misra, Jyoti R.; Horner, Michael A.; Lam, Geanette; Thummel, Carl S.

2011-01-01

Living organisms, from bacteria to humans, display a coordinated transcriptional response to xenobiotic exposure, inducing enzymes and transporters that facilitate detoxification. Several transcription factors have been identified in vertebrates that contribute to this regulatory response. In contrast, little is known about this pathway in insects. Here we show that the Drosophila Nrf2 (NF-E2-related factor 2) ortholog CncC (cap ‘n’ collar isoform-C) is a central regulator of xenobiotic detoxification responses. A binding site for CncC and its heterodimer partner Maf (muscle aponeurosis fibromatosis) is sufficient and necessary for robust transcriptional responses to three xenobiotic compounds: phenobarbital (PB), chlorpromazine, and caffeine. Genetic manipulations that alter the levels of CncC or its negative regulator, Keap1 (Kelch-like ECH-associated protein 1), lead to predictable changes in xenobiotic-inducible gene expression. Transcriptional profiling studies reveal that more than half of the genes regulated by PB are also controlled by CncC. Consistent with these effects on detoxification gene expression, activation of the CncC/Keap1 pathway in Drosophila is sufficient to confer resistance to the lethal effects of the pesticide malathion. These studies establish a molecular mechanism for the regulation of xenobiotic detoxification in Drosophila and have implications for controlling insect populations and the spread of insect-borne human diseases. PMID:21896655

Preliminary Development of Real Time Usage-Phase Monitoring System for CNC Machine Tools with a Case Study on CNC Machine VMC 250

NASA Astrophysics Data System (ADS)

Budi Harja, Herman; Prakosa, Tri; Raharno, Sri; Yuwana Martawirya, Yatna; Nurhadi, Indra; Setyo Nogroho, Alamsyah

2018-03-01

The production characteristic of job-shop industry at which products have wide variety but small amounts causes every machine tool will be shared to conduct production process with dynamic load. Its dynamic condition operation directly affects machine tools component reliability. Hence, determination of maintenance schedule for every component should be calculated based on actual usage of machine tools component. This paper describes study on development of monitoring system to obtaining information about each CNC machine tool component usage in real time approached by component grouping based on its operation phase. A special device has been developed for monitoring machine tool component usage by utilizing usage phase activity data taken from certain electronics components within CNC machine. The components are adaptor, servo driver and spindle driver, as well as some additional components such as microcontroller and relays. The obtained data are utilized for detecting machine utilization phases such as power on state, machine ready state or spindle running state. Experimental result have shown that the developed CNC machine tool monitoring system is capable of obtaining phase information of machine tool usage as well as its duration and displays the information at the user interface application.

Order and gelation of cellulose nanocrystal suspensions: an overview of some issues

NASA Astrophysics Data System (ADS)

Gray, Derek G.

2017-12-01

Cellulose nanocrystals (CNCs) are polydisperse rod-shaped particles of crystalline cellulose I, typically prepared by sulfuric acid hydrolysis of natural cellulose fibres to give aqueous colloidal suspensions stabilized by sulfate half-ester groups. Sufficiently dilute suspensions are isotropic fluids, but as the concentration of CNC in water is increased, a critical concentration is reached where a spontaneously ordered phase is observed. The (equilibrium) phase separation of the ordered chiral nematic phase is in competition with a tendency of the CNC suspension to form a gel. Qualitatively, factors that reduce the stability of the CNC suspension favour the onset of gelation. The chiral nematic structure is preserved, at least partially, when the suspension dries. Solid chiral nematic films of cellulose are of interest for their optical and templating properties, but the preparation of the films requires improvement. The processes that govern the formation of solid chiral nematic films from CNC suspensions include phase separation, gelation and also the effects of shear on CNC orientation during evaporation. Some insight into these processes is provided by polarized light microscopy, which indicates that the relaxation of shear-induced orientation to give a chiral nematic structure may occur via an intermediate twist-bend state. This article is part of a discussion meeting issue `New horizons for cellulose nanotechnology'.

Novel Lignocellulosic Composites

NASA Astrophysics Data System (ADS)

Peresin, Maria Soledad

2011-12-01

Obtained by acid hydrolysis of ramie fibers, cellulose nanocrystals (CNC) were used to reinforce nanofiber webs of different polymeric matrices via electrospinning. Poly vinyl acetate (PVA) with different degrees of hydrolysis was chosen due to its biodegradability and ease of processability. Homogeneous webs of smooth, defect-free and continuous fibers were prepared presenting diameters on the nanoscale, containing from 5 to 15% wt of CNC. The webs were characterized in terms of chemical, morphological, and thermo-mechanical properties. Strong interaction between PVA matrix with CNC, mainly via hydrogen bond network was evidenced; however, it was reduced in samples with higher content of acetyl groups. Most interestingly, the elastic modulus of the nanocomposite mats increased significantly as a consequence of the reinforcing effect of CNC, via the percolation network held by hydrogen bonds and the efficient stress transfer between the reinforcing CN and the fully hydrolyzed PVA electrospun fibers. Reduction in the degree of crystallinity of CN-loaded webs was observed as a result of transnucleation effect of the nanoparticles. Due to the hydrophilicity of the matrix, the effect of different relative humidities on the morphological and thermo-mechanical properties of the electrospun was also studied. The incorporation of CNC was shown to improve the morphological stability of the webs even at high humidity levels. The thermo-mechanical behavior of the electrospun fiber webs was drastically affected by the balance between the moisture-induced plasticization and the rigidity of the reinforcing CNC. Results indicated that water absorption might have a negative effect on the stabilizing effect of CNC in the PVA matrix due to a disruption of the hydrogen bond network within the structure. Humidity- induced reduction in tensile strength of neat PVA fiber webs was shown to be significantly prevented by the presence of CNC in the webs; and a fully reversible recovery in mechanical strength after cycling of relative humidity was observed in the CN-loaded PVA webs. Target applications for these ultra high surface area webs include the manufacture of sensors and selectively permeable membranes, in which case, their high hydrophilicity can be detrimental in applications were aqueous media is involved. In order to overcome this problem, we proposed a vapor phase, acid catalyzed crosslinking reaction, using maleic anhydride and posterior temperature curing. Interactions of the modified composite webs with solvent of different polarities were analyzed, as well as their mechanical integrity after water immersion, morphological, thermal, and chemical properties before and after modification. Finally, mixtures of cellulose acetate, dissolved in a mixture of acetone and dimethylacetamide, with different degrees of substitution were electrospun, obtaining nanofiber webs of various compositions. The fibers were reinforced with CNC, and also effectively deacetylated via alkaline hydrolysis, to obtain purely cellulosic webs. The effect of deacetylation on morphology and thermal behavior was evaluated using a variety of techniques. Results showed that thermal, surface and chemical properties of the fibers were drastically changed after deacetylation to cellulose; however, the morphological structure was preserved. Finally, the presence of CNC in the CA and regenerated cellulose polymeric matrix induced an increase in hydrophilicity on the electrospun webs, as revealed by water contact angle results.

Open Source Service Agent (OSSA) in the intelligence community's Open Source Architecture

NASA Technical Reports Server (NTRS)

Fiene, Bruce F.

1994-01-01

The Community Open Source Program Office (COSPO) has developed an architecture for the intelligence community's new Open Source Information System (OSIS). The architecture is a multi-phased program featuring connectivity, interoperability, and functionality. OSIS is based on a distributed architecture concept. The system is designed to function as a virtual entity. OSIS will be a restricted (non-public), user configured network employing Internet communications. Privacy and authentication will be provided through firewall protection. Connection to OSIS can be made through any server on the Internet or through dial-up modems provided the appropriate firewall authentication system is installed on the client.

Generation of gear tooth surfaces by application of CNC machines

NASA Technical Reports Server (NTRS)

Litvin, F. L.; Chen, N. X.

1994-01-01

This study will demonstrate the importance of application of computer numerically controlled (CNC) machines in generation of gear tooth surfaces with new topology. This topology decreases gear vibration and will extend the gear capacity and service life. A preliminary investigation by a tooth contact analysis (TCA) program has shown that gear tooth surfaces in line contact (for instance, involute helical gears with parallel axes, worm gear drives with cylindrical worms, etc.) are very sensitive to angular errors of misalignment that cause edge contact and an unfavorable shape of transmission errors and vibration. The new topology of gear tooth surfaces is based on the localization of bearing contact, and the synthesis of a predesigned parabolic function of transmission errors that is able to absorb a piecewise linear function of transmission errors caused by gear misalignment. The report will describe the following topics: description of kinematics of CNC machines with six degrees of freedom that can be applied for generation of gear tooth surfaces with new topology. A new method for grinding of gear tooth surfaces by a cone surface or surface of revolution based on application of CNC machines is described. This method provides an optimal approximation of the ground surface to the given one. This method is especially beneficial when undeveloped ruled surfaces are to be ground. Execution of motions of the CNC machine is also described. The solution to this problem can be applied as well for the transfer of machine tool settings from a conventional generator to the CNC machine. The developed theory required the derivation of a modified equation of meshing based on application of the concept of space curves, space curves represented on surfaces, geodesic curvature, surface torsion, etc. Condensed information on these topics of differential geometry is provided as well.

Surgical Management of Carney Complex-Associated Pituitary Pathology.

PubMed

Lonser, Russell R; Mehta, Gautam U; Kindzelski, Bogdan A; Ray-Chaudhury, Abhik; Vortmeyer, Alexander O; Dickerman, Robert; Oldfield, Edward H

2017-05-01

Carney complex (CNC) is a familial neoplasia syndrome that is associated with pituitary-associated hypersecretion of growth hormone (GH) (acromegaly). The underlying cause of pituitary GH hypersecretion and its management have been incompletely defined. To provide biological insight into CNC-associated pituitary pathology and improve management, we analyzed findings in CNC patients who underwent transsphenoidal surgery. Consecutive CNC patients at the National Institutes of Health with acromegaly and imaging evidence of a pituitary adenoma(s) who underwent transsphenoidal resection of tumor(s) were included. Prospectively acquired magnetic resonance imaging and biochemical, surgical, and histological data were analyzed. Seven acromegalic CNC patients (2 male, 5 female) were included. The mean age at surgery was 29.7 years (range, 18-44 years). The mean follow-up was 4.7 years (range, 0.2-129 months). Magnetic resonance imaging revealed a single pituitary adenoma in 4 patients and multiple pituitary adenomas in 3 patients. Whereas patients with single discrete pituitary adenomas underwent selective adenomectomy, patients with multiple adenomas underwent selective adenomectomy of multiple tumors, as well as partial or total hypophysectomy. All adenomas were either GH and prolactin positive or exclusively prolactin positive. Pituitary tissue surrounding the adenomas in patients with multiple adenomas revealed hyperplastic GH- and prolactin-positive tissue. CNC-associated acromegaly results from variable pituitary pathology, including a single GH-secreting adenoma or multiple GH-secreting adenomas and/or GH hypersecretion of the pituitary gland surrounding multiple adenomas. Although selective adenomectomy is the preferred treatment for cases of GH-secreting adenomas, multiple adenomas with associated pituitary gland GH hypersecretion may require partial or complete hypophysectomy to achieve biochemical remission. Copyright © 2017 by the Congress of Neurological Surgeons

Surgical Management of Carney Complex–Associated Pituitary Pathology

PubMed Central

Mehta, Gautam U.; Kindzelski, Bogdan A.; Ray-Chaudhury, Abhik; Vortmeyer, Alexander O.; Dickerman, Robert; Oldfield, Edward H.

2017-01-01

Abstract BACKGROUND: Carney complex (CNC) is a familial neoplasia syndrome that is associated with pituitary-associated hypersecretion of growth hormone (GH) (acromegaly). The underlying cause of pituitary GH hypersecretion and its management have been incompletely defined. OBJECTIVE: To provide biological insight into CNC-associated pituitary pathology and improve management, we analyzed findings in CNC patients who underwent transsphenoidal surgery. METHODS: Consecutive CNC patients at the National Institutes of Health with acromegaly and imaging evidence of a pituitary adenoma(s) who underwent transsphenoidal resection of tumor(s) were included. Prospectively acquired magnetic resonance imaging and biochemical, surgical, and histological data were analyzed. RESULTS: Seven acromegalic CNC patients (2 male, 5 female) were included. The mean age at surgery was 29.7 years (range, 18-44 years). The mean follow-up was 4.7 years (range, 0.2-129 months). Magnetic resonance imaging revealed a single pituitary adenoma in 4 patients and multiple pituitary adenomas in 3 patients. Whereas patients with single discrete pituitary adenomas underwent selective adenomectomy, patients with multiple adenomas underwent selective adenomectomy of multiple tumors, as well as partial or total hypophysectomy. All adenomas were either GH and prolactin positive or exclusively prolactin positive. Pituitary tissue surrounding the adenomas in patients with multiple adenomas revealed hyperplastic GH- and prolactin-positive tissue. CONCLUSION: CNC-associated acromegaly results from variable pituitary pathology, including a single GH-secreting adenoma or multiple GH-secreting adenomas and/or GH hypersecretion of the pituitary gland surrounding multiple adenomas. Although selective adenomectomy is the preferred treatment for cases of GH-secreting adenomas, multiple adenomas with associated pituitary gland GH hypersecretion may require partial or complete hypophysectomy to achieve biochemical remission. PMID:27509071

Space Generic Open Avionics Architecture (SGOAA): Overview

NASA Technical Reports Server (NTRS)

Wray, Richard B.; Stovall, John R.

1992-01-01

A space generic open avionics architecture created for NASA is described. It will serve as the basis for entities in spacecraft core avionics, capable of being tailored by NASA for future space program avionics ranging from small vehicles such as Moon ascent/descent vehicles to large ones such as Mars transfer vehicles or orbiting stations. The standard consists of: (1) a system architecture; (2) a generic processing hardware architecture; (3) a six class architecture interface model; (4) a system services functional subsystem architectural model; and (5) an operations control functional subsystem architectural model.

A Standard Platform for Testing and Comparison of MDAO Architectures

NASA Technical Reports Server (NTRS)

Gray, Justin S.; Moore, Kenneth T.; Hearn, Tristan A.; Naylor, Bret A.

2012-01-01

The Multidisciplinary Design Analysis and Optimization (MDAO) community has developed a multitude of algorithms and techniques, called architectures, for performing optimizations on complex engineering systems which involve coupling between multiple discipline analyses. These architectures seek to efficiently handle optimizations with computationally expensive analyses including multiple disciplines. We propose a new testing procedure that can provide a quantitative and qualitative means of comparison among architectures. The proposed test procedure is implemented within the open source framework, OpenMDAO, and comparative results are presented for five well-known architectures: MDF, IDF, CO, BLISS, and BLISS-2000. We also demonstrate how using open source soft- ware development methods can allow the MDAO community to submit new problems and architectures to keep the test suite relevant.

Restudy of malformations of the internal auditory meatus, cochlear nerve canal and cochlear nerve.

PubMed

Li, Youjin; Yang, Jun; Liu, Jinfen; Wu, Hao

2015-07-01

The present study aims to restudy the correlation between the internal auditory meatus (IAM), the cochlear nerve canal (CNC), the cochlear nerve (CN) and inner ear malformations. In this retrospective study design, the abnormal diameter of the IAM, CNC and CN in patients with any kind of inner ear malformations was evaluated using multi-slice spiral computed tomography (MSCT) (37 patients) and magnetic resonance imaging (MRI) (18 patients). Of 37 MSCT-diagnosed patients, 2 had IAM atresia, 11 IAM stenosis, 22 enlarged IAM, and 2 normal IAM with an abnormal CN. MRI diagnoses of 18 patients revealed 8 cases of aplastic CN, 6 hypoplastic CN, and 4 normal CN. CNC stenosis was associated with CN hypoplasia (P < 0.001). Patients with absent or stenotic IAM had less CN development than those with normal or enlarged IAM (P = 0.001). We propose a modification of the existing classification systems with a view to distinguishing malformations of the IAM, CNC and CN.

Photonic-structured fibers assembled from cellulose nanocrystals with tunable polarized selective reflection.

PubMed

Meng, Xin; Pan, Hui; Lu, Tao; Chen, Zhixin; Chen, Yanru; Zhang, Di; Zhu, Shenmin

2018-08-10

Fibers with self-assembled photonic structures are of special interest due to their unique photonic properties and potential applications in the smart textile industry. Inspired by nature, the photonic-structured fibers were fabricated through the self-assembly of chiral nematic cellulose nanocrystals (CNCs) and the fibers showed tunably brilliant and selectively reflected colors under crossed-polarization. A simple wet-spinning method was applied to prepare composite fibers of the mixed CNC matrix and polyvinyl alcohol (PVA) additions. During the processing, a cholesteric CNC phase formed photonic fibers through a self-assembly process. The selective color reflection of the composite fibers in the polarized condition showed a typical red-shift tendency with an increase in the PVA content, which was attributed to the increased helical pitch of the CNC. Furthermore, the polarized angle could also alter the reflected colors. Owing to their excellent selective reflection properties under the polarized condition, CNC-based photonic fibers are promising as the next-generation of smart fibers, applied in the fields of specific display and sensing.

Alginate based nanocomposite for microencapsulation of probiotic: Effect of cellulose nanocrystal (CNC) and lecithin.

PubMed

Huq, Tanzina; Fraschini, Carole; Khan, Avik; Riedl, Bernard; Bouchard, Jean; Lacroix, Monique

2017-07-15

Probiotic (Lactobacillus rhamnosus ATCC 9595) was encapsulated in alginate-CNC-lecithin microbeads to produce nutraceutical microcapsules. Addition of CNC and lecithin in alginate microbeads (ACL-1) improved the viability of L. rhamnosus during gastric passage and storage. The compression strength of the freeze-dried ACL-1 microbeads improved 40% compared to alginate microbeads alone. Swelling studies revealed that addition of CNC and lecithin in alginate microbeads decreased (around 47%) the gastric fluid absorption but increased the dissolution time by 20min compared to alginate microbeads (A-0). During transition through the gastric passage, the viability of L. rhamnosus in dried ACL-1 microbeads was increased 37% as compared to A-0 based beads. At 25 and 4°C storage conditions, the viability of L. rhamnosus encapsulated in ACL-1 microbeads decreased by 1.23 and 1.08 log respectively, whereas the encapsulation with A-0 microbeads exhibited a 3.17 and 1.93 log reduction respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Wnt receptor Frizzled-4 modulates ADAM13 metalloprotease activity

PubMed Central

Abbruzzese, Genevieve; Gorny, Anne-Kathrin; Kaufmann, Lilian T.; Cousin, Hélène; Kleino, Iivari; Steinbeisser, Herbert; Alfandari, Dominique

2015-01-01

ABSTRACT Cranial neural crest (CNC) cells are a transient population of stem cells that originate at the border of the neural plate and the epidermis, and migrate ventrally to contribute to most of the facial structures including bones, cartilage, muscles and ganglia. ADAM13 is a cell surface metalloprotease that is essential for CNC cell migration. Here, we show in Xenopus laevis embryos that the Wnt receptor Fz4 binds to the cysteine-rich domain of ADAM13 and negatively regulates its proteolytic activity in vivo. Gain of Fz4 function inhibits CNC cell migration and can be rescued by gain of ADAM13 function. Loss of Fz4 function also inhibits CNC cell migration and induces a reduction of mature ADAM13, together with an increase in the ADAM13 cytoplasmic fragment that is known to translocate into the nucleus to regulate gene expression. We propose that Fz4 associates with ADAM13 during its transport to the plasma membrane to regulate its proteolytic activity. PMID:25616895

Pseudo-random tool paths for CNC sub-aperture polishing and other applications.

PubMed

Dunn, Christina R; Walker, David D

2008-11-10

In this paper we first contrast classical and CNC polishing techniques in regard to the repetitiveness of the machine motions. We then present a pseudo-random tool path for use with CNC sub-aperture polishing techniques and report polishing results from equivalent random and raster tool-paths. The random tool-path used - the unicursal random tool-path - employs a random seed to generate a pattern which never crosses itself. Because of this property, this tool-path is directly compatible with dwell time maps for corrective polishing. The tool-path can be used to polish any continuous area of any boundary shape, including surfaces with interior perforations.

39 CFR 501.7 - Postage Evidencing System requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Performance Criteria for Information-Based Indicia and Security Architecture for Open IBI Postage Evidencing Systems or Performance Criteria for Information-Based Indicia and Security Architecture for Closed IBI... Information-Based Indicia and Security Architecture for Open IBI Postage Evidencing Systems or Performance...

39 CFR 501.7 - Postage Evidencing System requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Performance Criteria for Information-Based Indicia and Security Architecture for Open IBI Postage Evidencing Systems or Performance Criteria for Information-Based Indicia and Security Architecture for Closed IBI... Information-Based Indicia and Security Architecture for Open IBI Postage Evidencing Systems or Performance...

Pulmonary exposure to cellulose nanocrystals caused deleterious effects to reproductive system in male mice

PubMed Central

Farcas, Mariana T.; Kisin, Elena R.; Menas, Autumn L.; Gutkin, Dmitriy W.; Star, Alexander; Reiner, Richard S.; Yanamala, Naveena; Savolainen, Kai; Shvedova, Anna A.

2016-01-01

Over the past several years there has been an increased number of applications of cellulosic materials in many sectors, including the food industry, cosmetics, and pharmaceuticals. However, to date, there are few studies investigating the potential adverse effects of cellulose nanocrystals (CNC). The objective of this study was to determine long-term outcomes on the male reproductive system of mice upon repeated pharyngeal aspiration exposure to CNC. To achieve this, cauda epididymal sperm samples were analyzed for sperm concentration, motility, morphological abnormalities, and DNA damage. Testicular and epididymal oxidative damage was evaluated, as well as histopathology examination of testes. In addition, changes in levels of testosterone in testes and serum and of luteinizing hormone (LH) in serum were determined. Three months after the last administration, CNC exposure significantly altered sperm concentration, motility, cell morphology, and sperm DNA integrity. These parameters correlated with elevated proinflammatory cytokines levels and myeloperoxidase (MPO) activity in testes, as well as oxidative stress in both testes and epididymis. Exposure to CNC also produced damage to testicular structure, as evidenced by presence of interstitial edema, frequent dystrophic seminiferous tubules with arrested spermatogenesis and degenerating spermatocytes, and imbalance in levels of testosterone and LH. Taken together, these results demonstrate that pulmonary exposure to CNC induces sustained adverse effects in spermatocytes/spermatozoa, suggesting male reproductive toxicity. PMID:27558875

Modified cellulose nanocrystal for vitamin C delivery.

PubMed

Akhlaghi, Seyedeh Parinaz; Berry, Richard M; Tam, Kam Chiu

2015-04-01

Cellulose nanocrystal grafted with chitosan oligosaccharide (CNC-CSOS) was used to encapsulate vitamin C and prepare CNCS/VC complexes using tripolyphosphte via ionic complexation. The stability of vitamin C and the antioxidant activity of the CNCS/VC complexes were elucidated. The formation of the complex was confirmed using DSC and UV-vis spectrophotometry, and TEM was used to study the morphology of the complexes. The encapsulation efficiency of vitamin C at pH 3 and 5 was 71.6% ± 6.8 and 91.0 ± 1.0, respectively. Strong exothermic peaks observed in isothermal titration calorimetric (ITC) studies at pH 5 could be attributed to additional electrostatic interactions between CNC-CSOS and vitamin C at pH 5. The in vitro release of vitamin C from CNCS/VC complexes showed a sustained release of up to 20 days. The vitamin C released from CNCS/VC complex displayed higher stability compared with the control vitamin C solution, and this was also confirmed from the ITC thermograms. CNC-CSOS possessed a higher scavenging activity and faster antioxidant activity compared with its precursors, i.e., oxidized CNC and CSOS and their physical mixtures. Complexing vitamin C into CNC-CSOS particles yielded a dynamic antioxidant agent, where the vitamin C is released over time and displayed sustained antioxidant properties. Therefore, CNCS/VC can potentially be used in cosmeceutical applications as topical formulations.

Modeling of Geometric Error in Linear Guide Way to Improved the vertical three-axis CNC Milling machine’s accuracy

NASA Astrophysics Data System (ADS)

Kwintarini, Widiyanti; Wibowo, Agung; Arthaya, Bagus M.; Yuwana Martawirya, Yatna

2018-03-01

The purpose of this study was to improve the accuracy of three-axis CNC Milling Vertical engines with a general approach by using mathematical modeling methods of machine tool geometric errors. The inaccuracy of CNC machines can be caused by geometric errors that are an important factor during the manufacturing process and during the assembly phase, and are factors for being able to build machines with high-accuracy. To improve the accuracy of the three-axis vertical milling machine, by knowing geometric errors and identifying the error position parameters in the machine tool by arranging the mathematical modeling. The geometric error in the machine tool consists of twenty-one error parameters consisting of nine linear error parameters, nine angle error parameters and three perpendicular error parameters. The mathematical modeling approach of geometric error with the calculated alignment error and angle error in the supporting components of the machine motion is linear guide way and linear motion. The purpose of using this mathematical modeling approach is the identification of geometric errors that can be helpful as reference during the design, assembly and maintenance stages to improve the accuracy of CNC machines. Mathematically modeling geometric errors in CNC machine tools can illustrate the relationship between alignment error, position and angle on a linear guide way of three-axis vertical milling machines.

Achieving Better Buying Power through Acquisition of Open Architecture Software Systems for Web and Mobile Devices

DTIC Science & Technology

2016-02-22

SPONSORED REPORT SERIES Achieving Better Buying Power through Acquisition of Open Architecture Software Systems for Web and Mobile Devices 22...ACQUISITION RESEARCH PROGRAM SPONSORED REPORT SERIES Achieving Better Buying Power through Acquisition of Open Architecture Software Systems for Web ...Policy Naval Postgraduate School Executive Summary Many people within large enterprises rely on up to four Web -based or mobile devices for their

Low-dose, Chronic Exposure to Silver Nanoparticles Causes Mild Mitochondrial Alterations in the Liver of Sprague-Dawley Rat

DTIC Science & Technology

2014-05-10

of Sprague-Dawley rat CARLOS PALMEIRA CENTRO DE NEUROCIENCIAS E BIOLOGIA CELULAR (CNC) DEPARTAMENTO DE ZOOLOGIA COIMBRA 3000 - 329...CENTRO DE NEUROCIENCIAS E BIOLOGIA CELULAR (CNC) DEPARTAMENTO DE ZOOLOGIA COIMBRA 3000 - 329 PORTUGAL 8. PERFORMING ORGANIZATION REPORT NUMBER

CNC Preparation Meets Manufacturing Opportunity

ERIC Educational Resources Information Center

Cassola, Joel

2006-01-01

This article features the machining technology program at Cape Fear Community College (CFCC) of Wilmington, North Carolina. North Carolina's Cape Fear Community College is working to meet diverse industry needs through its CNC training. The school's program has gained the attention of the local manufacturing community and students when it shifted…

Hydrogenation of imines catalysed by ruthenium(II) complexes based on lutidine-derived CNC pincer ligands.

PubMed

Hernández-Juárez, Martín; Vaquero, Mónica; Álvarez, Eleuterio; Salazar, Verónica; Suárez, Andrés

2013-01-14

The preparation of new Ru(II) complexes incorporating fac-coordinated lutidine-derived CNC ligands is reported. These derivatives are selectively deprotonated by (t)BuOK at one of the methylene arms of the pincer, leading to catalytically active species in the hydrogenation of imines.

Correction: A binary catalyst system of a cationic Ru-CNC pincer complex with an alkali metal salt for selective hydroboration of carbon dioxide.

PubMed

Ng, Chee Koon; Wu, Jie; Hor, T S Andy; Luo, He-Kuan

2016-12-22

Correction for 'A binary catalyst system of a cationic Ru-CNC pincer complex with an alkali metal salt for selective hydroboration of carbon dioxide' by Chee Koon Ng et al., Chem. Commun., 2016, 52, 11842-11845.

Improved estimation of nitrogen uptake in grasslands using the nitrogen dilution curve

USDA-ARS?s Scientific Manuscript database

The critical nitrogen concentration (CNC) is a simple yet robust relationship that describes the changes in crop N during growth. We applied the concept of CNC to calculate N uptake across various cutting regimes. While it is well-established that decreasing cutting frequency changes growth rates, t...

CNC Turning Technician. A Competency-Based Instructional System.

ERIC Educational Resources Information Center

Sloan, Kelly; Hilley, Robert

This competency-based curriculum guide for instructing students in using computer numerically controlled (CNC) turning machines is one of a series of instructional guides for the machinist field developed in Oklahoma. Although developed jointly with Baxter Technologies Corporation and oriented toward the Baxter Vo-Tec 2000 Future Builder CNC…

Cadherin-11 regulates protrusive activity in Xenopus cranial neural crest cells upstream of Trio and the small GTPases.

PubMed

Kashef, Jubin; Köhler, Almut; Kuriyama, Sei; Alfandari, Dominique; Mayor, Roberto; Wedlich, Doris

2009-06-15

Xenopus Cadherin-11 (Xcad-11) is expressed when cranial neural crest cells (CNC) acquire motility. However, its function in stimulating cell migration is poorly understood. Here, we demonstrate that Xcad-11 initiates filopodia and lamellipodia formation, which is essential for CNC to populate pharyngeal pouches. We identified the cytoplasmic tail of Xcad-11 as both necessary and sufficient for proper CNC migration as long as it was linked to the plasma membrane. Our results showing that guanine nucleotide exchange factor (GEF)-Trio binds to Xcad-11 and can functionally substitute for it like constitutively active forms of RhoA, Rac, and cdc42 unravel a novel cadherin function.

Mechanical and thermal properties of waterborne epoxy composites containing cellulose nanocrystals

Treesearch

Shanhong Xu; Natalie Girouard; Gregory Schueneman; Meisha L. Shofner; J. Carson Meredith

2013-01-01

Cellulose nanocrystals (CNCs) are reinforcing fillers of emerging interest for polymers due to their high modulus and potential for sustainable production. In this study, CNC-based composites with a waterborne epoxy resin matrix were prepared and characterized to determine morphology, water content, and thermal and mechanical properties. While some CNC aggregation was...

Effect of particle Alignment on mechanical properties of neat cellulose nanocrystal films

Treesearch

Alexander B. Reising; Robert J. Moon; Jeffrey P. Youngblood

2012-01-01

Shear-based film casting methods were used to cast neat films from wood-based cellulose nanocrystal (CNC) suspensions. The degree of CNC alignment in dried films was characterized using the Hermans order parameter (S), and the film elastic modulus (E), ultimate tensile strength (σf ), elongation at failure (εf...

78 FR 50135 - CNC Development, Ltd., Exousia Advanced Materials, Inc., and South American Minerals, Inc.; Order...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-16

... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] CNC Development, Ltd., Exousia Advanced Materials, Inc., and South American Minerals, Inc.; Order of Suspension of Trading August 14, 2013. It... securities of South American Minerals, Inc. because it has not filed any periodic reports since it filed a...

Water vapor sorption properties of cellulose nanocrystals and nanofibers using dynamic vapor sorption apparatus.

PubMed

Guo, Xin; Wu, Yiqiang; Xie, Xinfeng

2017-10-27

Hygroscopic behavior is an inherent characteristic of nanocellulose which strongly affects its applications. In this study, the water vapor sorption behavior of four nanocellulose samples, such as cellulose nanocrystals and nanofibers with cellulose I and II structures (cellulose nanocrystals (CNC) I, CNC II, cellulose nanofibers (CNF) I, and CNF II) were studied by dynamic vapor sorption. The highly reproducible data including the running time, real-time sample mass, target relative humidity (RH), actual RH, and isotherm temperature were recorded during the sorption process. In analyzing these data, significant differences in the total running time, equilibrium moisture content, sorption hysteresis and sorption kinetics between these four nanocellulose samples were confirmed. It was important to note that CNC I, CNC II, CNF I, and CNF II had equilibrium moisture contents of 21.4, 28.6, 33.2, and 38.9%, respectively, at a RH of 95%. Then, the sorption kinetics behavior was accurately described by using the parallel exponential kinetics (PEK) model. Furthermore, the Kelvin-Voigt model was introduced to interpret the PEK behavior and calculate the modulus of these four nanocellulose samples.

The Wnt receptor Frizzled-4 modulates ADAM13 metalloprotease activity.

PubMed

Abbruzzese, Genevieve; Gorny, Anne-Kathrin; Kaufmann, Lilian T; Cousin, Hélène; Kleino, Iivari; Steinbeisser, Herbert; Alfandari, Dominique

2015-03-15

Cranial neural crest (CNC) cells are a transient population of stem cells that originate at the border of the neural plate and the epidermis, and migrate ventrally to contribute to most of the facial structures including bones, cartilage, muscles and ganglia. ADAM13 is a cell surface metalloprotease that is essential for CNC cell migration. Here, we show in Xenopus laevis embryos that the Wnt receptor Fz4 binds to the cysteine-rich domain of ADAM13 and negatively regulates its proteolytic activity in vivo. Gain of Fz4 function inhibits CNC cell migration and can be rescued by gain of ADAM13 function. Loss of Fz4 function also inhibits CNC cell migration and induces a reduction of mature ADAM13, together with an increase in the ADAM13 cytoplasmic fragment that is known to translocate into the nucleus to regulate gene expression. We propose that Fz4 associates with ADAM13 during its transport to the plasma membrane to regulate its proteolytic activity. © 2015. Published by The Company of Biologists Ltd.

Grafting polycaprolactone diol onto cellulose nanocrystals via click chemistry: Enhancing thermal stability and hydrophobic property.

PubMed

Zhou, Ling; He, Hui; Li, Mei-Chun; Huang, Siwei; Mei, Changtong; Wu, Qinglin

2018-06-01

Hydrophobic and thermally-stable cellulose nanocrystals (CNCs) were synthesized by polycarpolactone diol (PCL diol) grafting via click chemistry strategy. The synthesis was designed as a three-step procedure containing azide-modification of CNCs, alkyne-modification of PCL diol and sequent copper(I)-catalyzed azide-alkyne cycloaddition reaction. The structure of azide-modified CNCs and alkyne-modified PCL diol, the structure, hydrophobic ability and thermal stability of click products CNC-PCL were characterized. FTIR, XPS and H 1 NMR results indicated a successful grafting of the N 3 groups onto the CNCs, synthesis of PCL diol-CCH, and formation of the CNC-PCL material. CNC-PCL had enhanced dispersion in the non-polar solvent chloroform owing to the well-maintained microscale size and PCL-induced hydrophobic surface. The thermal stability of CNC-PCL was largely increased due to the grafting of thermally-stable PCL. This work demonstrates that click chemistry is an attractive modification strategy to graft CNCs with polyester chains for further potential application in polymer composites. Copyright © 2018 Elsevier Ltd. All rights reserved.

VizieR Online Data Catalog: Radial velocities and BVIc LCs of the EB* CU Cnc (Wilson+, 2017)

NASA Astrophysics Data System (ADS)

Wilson, R. E.; Pilachowski, C. A.; Terrell, D.

2017-09-01

Infrared spectra of CU Cnc were obtained with the Phoenix spectrometer on the 2.1 and 4m telescopes at Kitt Peak National Observatory in 2013 December, and 2014 January and February (λc=2.33um, R=50000). The primary star is defined here as the slightly hotter and more massive one that is eclipsed near zero phase according to the ephemeris. High-resolution optical spectra of CU Cnc were obtained for estimation of elemental abundances. An 1800s observation was obtained on 2014 May 17 with the Astrophysical Research Consortium (ARC) echelle spectrograph (ARCES) at a phase near quadrature. A second spectrum was obtained with the same instrument on 2015 November 21 with an exposure time of 3600s at a phase near conjunction. The spectra cover the wavelength range from 3500 to 10000Å and resolving power is about 31500. The CU Cnc field was observed at the Sonoita Research Observatory with Johnson-Cousins BVIC and SDSS g'r'i' filters. (2 data files).

Mission Systems Open Architecture Science and Technology (MOAST) program

NASA Astrophysics Data System (ADS)

Littlejohn, Kenneth; Rajabian-Schwart, Vahid; Kovach, Nicholas; Satterthwaite, Charles P.

2017-04-01

The Mission Systems Open Architecture Science and Technology (MOAST) program is an AFRL effort that is developing and demonstrating Open System Architecture (OSA) component prototypes, along with methods and tools, to strategically evolve current OSA standards and technical approaches, promote affordable capability evolution, reduce integration risk, and address emerging challenges [1]. Within the context of open architectures, the program is conducting advanced research and concept development in the following areas: (1) Evolution of standards; (2) Cyber-Resiliency; (3) Emerging Concepts and Technologies; (4) Risk Reduction Studies and Experimentation; and (5) Advanced Technology Demonstrations. Current research includes the development of methods, tools, and techniques to characterize the performance of OMS data interconnection methods for representative mission system applications. Of particular interest are the OMS Critical Abstraction Layer (CAL), the Avionics Service Bus (ASB), and the Bulk Data Transfer interconnects, as well as to develop and demonstrate cybersecurity countermeasures techniques to detect and mitigate cyberattacks against open architecture based mission systems and ensure continued mission operations. Focus is on cybersecurity techniques that augment traditional cybersecurity controls and those currently defined within the Open Mission System and UCI standards. AFRL is also developing code generation tools and simulation tools to support evaluation and experimentation of OSA-compliant implementations.

Complexity of CNC transcription factors as revealed by gene targeting of the Nrf3 locus.

PubMed

Derjuga, Anna; Gourley, Tania S; Holm, Teresa M; Heng, Henry H Q; Shivdasani, Ramesh A; Ahmed, Rafi; Andrews, Nancy C; Blank, Volker

2004-04-01

Cap'n'collar (CNC) family basic leucine zipper transcription factors play crucial roles in the regulation of mammalian gene expression and development. To determine the in vivo function of the CNC protein Nrf3 (NF-E2-related factor 3), we generated mice deficient in this transcription factor. We performed targeted disruption of two Nrf3 exons coding for CNC homology, basic DNA-binding, and leucine zipper dimerization domains. Nrf3 null mice developed normally and revealed no obvious phenotypic differences compared to wild-type animals. Nrf3(-/-) mice were fertile, and gross anatomy as well as behavior appeared normal. The mice showed normal age progression and did not show any apparent additional phenotype during their life span. We observed no differences in various blood parameters and chemistry values. We infected wild-type and Nrf3(-/-) mice with acute lymphocytic choriomeningitis virus and found no differences in these animals with respect to their number of virus-specific CD8 and CD4 T cells as well as their B-lymphocyte response. To determine whether the mild phenotype of Nrf3 null animals is due to functional redundancy, we generated mice deficient in multiple CNC factors. Contrary to our expectations, an absence of Nrf3 does not seem to cause additional lethality in compound Nrf3(-/-)/Nrf2(-/-) and Nrf3(-/-)/p45(-/-) mice. We hypothesize that the role of Nrf3 in vivo may become apparent only after appropriate challenge to the mice.

Polyurethane acrylate networks including cellulose nanocrystals: a comparison between UV and EB- curing

NASA Astrophysics Data System (ADS)

Furtak-Wrona, K.; Kozik-Ostrówka, P.; Jadwiszczak, K.; Maigret, J. E.; Aguié-Béghin, V.; Coqueret, X.

2018-01-01

A water-based polyurethane (PUR) acrylate water emulsion was selected as a radiation curable matrix for preparing nanocomposites including cellulose nanocrystals (CNC) prepared by controlled hydrolysis of Ramie fibers. Cross-linking polymerization of samples prepared in the form of films or of 1 mm-thick bars was either initiated by exposure to the 395 nm light of a high intensity LED lamp or by treatment with low energy electron beam (EB). The conversion level of acrylate functions in samples submitted to increasing radiation doses was monitored by Fourier Transform Infrared Spectroscopy (FTIR). Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) were used to characterize changes in the glass transition temperature of the PUR-CNC nanocomposites as a function of acrylate conversion and of CNC content. Micromechanical testing indicates the positive effect of 1 wt% CNC on Young's modulus and on the tensile strength at break (σ) of cured nanocomposites. The presence of CNC in the PUR acrylate matrix was shown to double the σ value of the nanocomposite cured to an acrylate conversion level of 85% by treatment with a 25 kGy dose under EB, whereas no increase of σ was observed in UV-cured samples exhibiting the same acrylate conversion level. The occurrence of grafting reactions inducing covalent linkages between the polysaccharide nanofiller and the PUR acrylate matrix during the EB treatment is advanced as an explanation to account for the improvement observed in samples cured under ionizing radiation.

Sustained Local Release of NGF from a Chitosan-Sericin Composite Scaffold for Treating Chronic Nerve Compression.

PubMed

Zhang, Lei; Yang, Wen; Tao, Kaixiong; Song, Yu; Xie, Hongjian; Wang, Jian; Li, Xiaolin; Shuai, Xiaoming; Gao, Jinbo; Chang, Panpan; Wang, Guobin; Wang, Zheng; Wang, Lin

2017-02-01

Chronic nerve compression (CNC), a common form of peripheral nerve injury, always leads to chronic peripheral nerve pain and dysfunction. Current available treatments for CNC are ineffective as they usually aim to alleviate symptoms at the acute phase with limited capability toward restoring injured nerve function. New approaches for effective recovery of CNC injury are highly desired. Here we report for the first time a tissue-engineered approach for the repair of CNC. A genipin cross-linked chitosan-sericin 3D scaffold for delivering nerve growth factor (NGF) was designed and fabricated. This scaffold combines the advantages of both chitosan and sericin, such as high porosity, adjustable mechanical properties and swelling ratios, the ability of supporting Schwann cells growth, and improving nerve regeneration. The degradation products of the composite scaffold upregulate the mRNA levels of the genes important for facilitating nerve function recovery, including glial-derived neurotrophic factor (GDNF), early growth response 2 (EGR2), and neural cell adhesion molecule (NCAM) in Schwann cells, while down-regulating two inflammatory genes' mRNA levels in macrophages, tumor necrosis factor alpha (TNF-α), and interleukin-1 beta (IL-1β). Importantly, our tissue-engineered strategy achieves significant nerve functional recovery in a preclinical CNC animal model by decreasing neuralgia, improving nerve conduction velocity (NCV), accelerating microstructure restoration, and attenuating gastrocnemius muscles dystrophy. Together, this work suggests a promising clinical alternative for treating chronic peripheral nerve compression injury.

A whole-of-curriculum approach to improving nursing students' applied numeracy skills.

PubMed

van de Mortel, Thea F; Whitehair, Leeann P; Irwin, Pauletta M

2014-03-01

Nursing students often perform poorly on numeracy tests. Whilst one-off interventions have been trialled with limited success, a whole-of-curriculum approach may provide a better means of improving applied numeracy skills. The objective of the study is to assess the efficacy of a whole-of-curriculum approach in improving nursing students' applied numeracy skills. Two cycles of assessment, implementation and evaluation of strategies were conducted following a high fail rate in the final applied numeracy examination in a Bachelor of Nursing (BN) programme. Strategies included an early diagnostic assessment followed by referral to remediation, setting the pass mark at 100% for each of six applied numeracy examinations across the programme, and employing a specialist mathematics teacher to provide consistent numeracy teaching. The setting of the study is one Australian university. 1035 second and third year nursing students enrolled in four clinical nursing courses (CNC III, CNC IV, CNC V and CNC VI) were included. Data on the percentage of students who obtained 100% in their applied numeracy examination in up to two attempts were collected from CNCs III, IV, V and VI between 2008 and 2011. A four by two χ(2) contingency table was used to determine if the differences in the proportion of students achieving 100% across two examination attempts in each CNC were significantly different between 2008 and 2011. The percentage of students who obtained 100% correct answers on the applied numeracy examinations was significantly higher in 2011 than in 2008 in CNC III (χ(2)=272, 3; p<0.001), IV (χ(2)=94.7, 3; p<0.001) and VI (χ(2)=76.3, 3; p<0.001). A whole-of-curriculum approach to developing applied numeracy skills in BN students resulted in a substantial improvement in these skills over four years. Copyright © 2013 Elsevier Ltd. All rights reserved.

Achieving Better Buying Power through Acquisition of Open Architecture Software Systems. Volume 2 Understanding Open Architecture Software Systems: Licensing and Security Research and Recommendations

DTIC Science & Technology

2016-01-06

of- breed software components and software products lines (SPLs) that are subject to different IP license and cybersecurity requirements. The... commercially priced closed source software components, to be used in the design, implementation, deployment, and evolution of open architecture (OA... breed software components and software products lines (SPLs) that are subject to different IP license and cybersecurity requirements. The Department

A comparison between customized clear and removable orthodontic appliances manufactured using RP and CNC techniques.

PubMed

Martorelli, Massimo; Gerbino, Salvatore; Giudice, Michele; Ausiello, Pietro

2013-02-01

Aim of the research is to compare the orthodontic appliances fabricated by using rapid prototyping (RP) systems, in particular 3D printers, with those manufactured by using computer numerical control (CNC) milling machines. 3D printing is today a well-accepted technology to fabricate orthodontic aligners by using the thermoforming process, instead the potential of CNC systems in dentistry have not yet been sufficiently explored. One patient, with mal-positioned maxillary central and lateral incisors, was initially selected. In the computer aided virtual planning was defined that, for the treatment, the patient needed to wear a series of 7 removable orthodontic appliances (ROA) over a duration of 21 weeks, with one appliance for every 3 weeks. A non-contact reverse engineering (RE) structured-light 3D scanner was used to create the 3D STL model of the impression of the patient's mouth. Numerical FEM simulations were performed varying the position of applied forces (discrete and continuous forces) on the same model, simulating, in this way, 3 models with slice thickness of 0.2 mm, 0.1 mm (RP staircase effect) and without slicing (ideal case). To define the areas of application of forces, two configuration "i" and "i-1" of the treatment were overlapped. 6 patients to which for three steps (3rd, 4th and 5th step) were made to wear aligners fabricated starting from physical models by 3D printing (3DP-ROA) and afterwards, for the next steps (6th, 7th and 8th step), aligners fabricated starting from physical models by CNC milling machine (CNC-ROA), were selected. For the 6 patients wearing the CNC-ROA, it was observed a best fitting of the aligner to the teeth and a more rapid teeth movement than the 3DP-ROA (2 weeks compared to 3 weeks for every appliance). FEM simulations showed a more uniform stress distribution for CNC-ROA than 3DP-ROA. In this research, 6 different case studies and CAD-FEM simulations showed that, to fabricate an efficient clear and removable orthodontic aligner, it is necessary to consider a compromise of several factors. A lower staircase effect (lower layer thickness) and a higher physical prototype accuracy allow a better control of tooth movement. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

An Open Specification for Space Project Mission Operations Control Architectures

NASA Technical Reports Server (NTRS)

Hooke, A.; Heuser, W. R.

1995-01-01

An 'open specification' for Space Project Mission Operations Control Architectures is under development in the Spacecraft Control Working Group of the American Institute for Aeronautics and Astro- nautics. This architecture identifies 5 basic elements incorporated in the design of similar operations systems: Data, System Management, Control Interface, Decision Support Engine, & Space Messaging Service.

LCA Study for Pilot Scale Production of Cellulose Nano Crystals (CNC) from Wood Pulp

Treesearch

Hongmei Gu; Richard Reiner; Richard Bergman; Alan Rudie

2015-01-01

Interest in cellulose nanocrystals (CNC)/cellulose nanofibrils (CNF) made from woody biomass has been growing rapidly with close attention from pulp and paper industry, governments, universities, and research institutes. Many new products development with CNCs have been studied intensively. However, little life-cycle analysis (LCA) has been conducted for the...

Chapter 1.4: Spatially Resolved Characterization of CNC-Polypropylene composite by Confocal Raman Microscopy

Treesearch

Umesh Agarwal; Ronald Sabo; Richard Reiner; Craig Clemons; Alan Rudie

2013-01-01

Raman spectroscopy was used to analyze cellulose nanocrystal (CNC)-polypropylene (PP) composites and to investigate the spatial distribution of CNCs in extruded composite filaments. Three composites were made from two forms of nanocellulose (CNCs from wood pulp and the nanoscale fraction of microcrystalline cellulose), and two of the three composites...

Technical and Symbolic Knowledge in CNC Machining: A Study of Technical Workers of Different Backgrounds.

ERIC Educational Resources Information Center

Martin, Laura M. W.; Beach, King

Performances of 45 individuals with varying degrees of formal and informal training in machining and programming were compared on tasks designed to tap intellectual changes that may occur with the introduction of computer numerical control (CNC). Participants--30 machinists, 8 machine operators, and 7 engineers--were asked background questions and…

Infrared laser spectroscopy of CNC(+)

NASA Astrophysics Data System (ADS)

Feher, Miklos; Salud, Carlos; Maier, John P.

1991-04-01

The CNC(+) ion has been detected in the gas phase by tunable diode-laser spectroscopy in a hallow cathode discharge. The (001)-(000), (011)-(010), (021)-(020), and the (031)-(030) transitions were observed and analyzed. The derived spectroscopic constants for the ground vibrational state are: nu(0) = 1974.07172(65)/cm and B(0) = 0.460 609(39)/cm.

78 FR 67215 - Norfolk Southern Railway Company-Abandonment Exemption-in Fayette and Wayne Counties, Ind.; C&NC...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-08

... Wayne Counties, Ind.; C&NC Railroad Corporation-- Discontinuance of Service Exemption--in Fayette and...-Exempt Abandonments and Discontinuances of Service for NSR to abandon, and for CNUR to discontinue service over, approximately 0.61 miles of rail line between milepost CB 4.80 (near East County Road 450N...

Fidget with Widgets: CNC Activity Introduces the Flatbed Router

ERIC Educational Resources Information Center

Tryon, Daniel V.

2006-01-01

The computer numerical control (CNC) flatbed router is a powerful tool and a must-have piece of equipment for any technology education program in which students will produce a product--whether it involves Manufacturing, Materials Processing, or any of the vast array of Project Lead the Way courses. This article describes an activity--producing a…

A strategy for prediction of the elastic properties of epoxy-cellulose nanocrystal-reinforced fiber networks

Treesearch

Johnathan E. Goodsell; Robert J. Moon; Alionso Huizar; R. Byron Pipes

2014-01-01

The reinforcement potential of cellulose nanocrystal (CNC) additions on an idealized 2-dirmensional (2-D) fiber network structure consisting of micron sized fiber elements was investigated. The reinforcement mechanism considered in this study was through the stiffening of the micron sized fiber elements via a CNC-epoxy coating. A hierarchical analytical modeling...

Influence of high loading of cellulose nanocrystals in polyacrylonitrile composite films

Treesearch

Jeffrey Luo; Huibin Chang; Amir A. Bakhtiary Davijani; H. Clive Liu; Po-Hsiang Wang; Robert J. Moon; Satish Kumar

2017-01-01

Polyacrylonitrile-co-methacrylic acid (PAN-co-MAA) and cellulose nanocrystal (CNC) composite films were produced with up to 40 wt% CNC loading through the solution casting method. The rheological properties of the solution/suspensions and the structural, optical, thermal, and mechanical properties of the resulting films were investigated. The viscosity of the composite...

Polyimide Cellulose Nanocrystal Composite Aerogels

NASA Technical Reports Server (NTRS)

Nguyen, Baochau N.; Meador, Mary Ann; Rowan, Stuart; Cudjoe, Elvis; Sandberg, Anna

2014-01-01

Polyimide (PI) aerogels are highly porous solids having low density, high porosity and low thermal conductivity with good mechanical properties. They are ideal for various applications including use in antenna and insulation such as inflatable decelerators used in entry, decent and landing operations. Recently, attention has been focused on stimuli responsive materials such as cellulose nano crystals (CNCs). CNCs are environmentally friendly, bio-renewable, commonly found in plants and the dermis of sea tunicates, and potentially low cost. This study is to examine the effects of CNC on the polyimide aerogels. The CNC used in this project are extracted from mantle of a sea creature called tunicates. A series of polyimide cellulose nanocrystal composite aerogels has been fabricated having 0-13 wt of CNC. Results will be discussed.

Cadherin-11 regulates protrusive activity in Xenopus cranial neural crest cells upstream of Trio and the small GTPases

PubMed Central

Kashef, Jubin; Köhler, Almut; Kuriyama, Sei; Alfandari, Dominique; Mayor, Roberto; Wedlich, Doris

2009-01-01

Xenopus Cadherin-11 (Xcad-11) is expressed when cranial neural crest cells (CNC) acquire motility. However, its function in stimulating cell migration is poorly understood. Here, we demonstrate that Xcad-11 initiates filopodia and lamellipodia formation, which is essential for CNC to populate pharyngeal pouches. We identified the cytoplasmic tail of Xcad-11 as both necessary and sufficient for proper CNC migration as long as it was linked to the plasma membrane. Our results showing that guanine nucleotide exchange factor (GEF)-Trio binds to Xcad-11 and can functionally substitute for it like constitutively active forms of RhoA, Rac, and cdc42 unravel a novel cadherin function. PMID:19528317

Morphological and spectroscopic analysis of cellulose nanocrystals extracted from oil palm empty fruit bunch fiber

NASA Astrophysics Data System (ADS)

Dasan, Y. K.; Bhat, A. H.; Faiz, A.

2015-07-01

This work evaluates the use of oil palm empty fruit bunch (OPEFB) fiber as a source of cellulose to obtain nanocrystalline cellulose (CNC) by acid hydrolysis reaction. The raw OPEFB fibers were pretreated with aqueous Sodium hydroxide at 80°C followed by bleaching treatment and further hydrolyzed with Sulphuric acid at 45°C with limited range of hydrolysis time and acid concentration. The resulting CNC's were characterized for spectroscopic, crystallographic and morphological properties using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffractometer (XRD), Transmission Electron Microscope (TEM) and Atomic Force Microscopy (AFM). Finding of this study shows that the properties of CNC's are strongly dependent on the hydrolysis time and acid concentration.

Accuracy Improvement of Multi-Axis Systems Based on Laser Correction of Volumetric Geometric Errors

NASA Astrophysics Data System (ADS)

Teleshevsky, V. I.; Sokolov, V. A.; Pimushkin, Ya I.

2018-04-01

The article describes a volumetric geometric errors correction method for CNC- controlled multi-axis systems (machine-tools, CMMs etc.). The Kalman’s concept of “Control and Observation” is used. A versatile multi-function laser interferometer is used as Observer in order to measure machine’s error functions. A systematic error map of machine’s workspace is produced based on error functions measurements. The error map results into error correction strategy. The article proposes a new method of error correction strategy forming. The method is based on error distribution within machine’s workspace and a CNC-program postprocessor. The postprocessor provides minimal error values within maximal workspace zone. The results are confirmed by error correction of precision CNC machine-tools.

Motion Simulation Analysis of Rail Weld CNC Fine Milling Machine

NASA Astrophysics Data System (ADS)

Mao, Huajie; Shu, Min; Li, Chao; Zhang, Baojun

CNC fine milling machine is a new advanced equipment of rail weld precision machining with high precision, high efficiency, low environmental pollution and other technical advantages. The motion performance of this machine directly affects its machining accuracy and stability, which makes it an important consideration for its design. Based on the design drawings, this article completed 3D modeling of 60mm/kg rail weld CNC fine milling machine by using Solidworks. After that, the geometry was imported into Adams to finish the motion simulation analysis. The displacement, velocity, angular velocity and some other kinematical parameters curves of the main components were obtained in the post-processing and these are the scientific basis for the design and development for this machine.

A Field Programmable Gate Array-Based Reconfigurable Smart-Sensor Network for Wireless Monitoring of New Generation Computer Numerically Controlled Machines

PubMed Central

Moreno-Tapia, Sandra Veronica; Vera-Salas, Luis Alberto; Osornio-Rios, Roque Alfredo; Dominguez-Gonzalez, Aurelio; Stiharu, Ion; de Jesus Romero-Troncoso, Rene

2010-01-01

Computer numerically controlled (CNC) machines have evolved to adapt to increasing technological and industrial requirements. To cover these needs, new generation machines have to perform monitoring strategies by incorporating multiple sensors. Since in most of applications the online Processing of the variables is essential, the use of smart sensors is necessary. The contribution of this work is the development of a wireless network platform of reconfigurable smart sensors for CNC machine applications complying with the measurement requirements of new generation CNC machines. Four different smart sensors are put under test in the network and their corresponding signal processing techniques are implemented in a Field Programmable Gate Array (FPGA)-based sensor node. PMID:22163602

A field programmable gate array-based reconfigurable smart-sensor network for wireless monitoring of new generation computer numerically controlled machines.

PubMed

Moreno-Tapia, Sandra Veronica; Vera-Salas, Luis Alberto; Osornio-Rios, Roque Alfredo; Dominguez-Gonzalez, Aurelio; Stiharu, Ion; Romero-Troncoso, Rene de Jesus

2010-01-01

Computer numerically controlled (CNC) machines have evolved to adapt to increasing technological and industrial requirements. To cover these needs, new generation machines have to perform monitoring strategies by incorporating multiple sensors. Since in most of applications the online Processing of the variables is essential, the use of smart sensors is necessary. The contribution of this work is the development of a wireless network platform of reconfigurable smart sensors for CNC machine applications complying with the measurement requirements of new generation CNC machines. Four different smart sensors are put under test in the network and their corresponding signal processing techniques are implemented in a Field Programmable Gate Array (FPGA)-based sensor node.

Placebo-Controlled Trial of Familiar Auditory Sensory Training for Acute Severe Traumatic Brain Injury: A Preliminary Report.

PubMed

Pape, Theresa Louise-Bender; Rosenow, Joshua M; Steiner, Monica; Parrish, Todd; Guernon, Ann; Harton, Brett; Patil, Vijaya; Bhaumik, Dulal K; McNamee, Shane; Walker, Matthew; Froehlich, Kathleen; Burress, Catherine; Odle, Cheryl; Wang, Xue; Herrold, Amy A; Zhao, Weihan; Reda, Domenic; Mallinson, Trudy; Conneely, Mark; Nemeth, Alexander J

2015-07-01

Sensory stimulation is often provided to persons incurring severe traumatic brain injury (TBI), but therapeutic effects are unclear. This preliminary study investigated neurobehavioral and neurophysiological effects related to sensory stimulation on global neurobehavioral functioning, arousal, and awareness. A double-blind randomized placebo-controlled trial where 15 participants in states of disordered consciousness (DOC), an average of 70 days after TBI, were provided either the Familiar Auditory Sensory Training (FAST) or Placebo of silence. Global neurobehavioral functioning was measured with the Disorders of Consciousness Scale (DOCS). Arousal and awareness were measured with the Coma-Near-Coma (CNC) scale. Neurophysiological effect was measured using functional magnetic resonance imaging (fMRI). FAST (n = 8) and Placebo (n = 7) groups each showed neurobehavioral improvement. Mean DOCS change (FAST = 13.5, SD = 8.2; Placebo = 18.9, SD = 15.6) was not different, but FAST patients had significantly (P = .049; 95% confidence interval [CI] = -1.51, -.005) more CNC gains (FAST = 1.01, SD = 0.60; Placebo = 0.25, SD = 0.70). Mixed-effects models confirm CNC findings (P = .002). Treatment effect, based on CNC, is large (d = 1.88, 95% CI = 0.77, 3.00). Number needed to treat is 2. FAST patients had more fMRI activation in language regions and whole brain (P values <.05) resembling healthy controls' activation. For persons with DOC 29 to 170 days after TBI, FAST resulted in CNC gains and increased neural responsivity to vocal stimuli in language regions. Clinicians should consider providing the FAST to support patient engagement in neurorehabilitation. © The Author(s) 2015.

Valence shell threshold photoelectron spectroscopy of the CHxCN (x = 0-2) and CNC radicals.

PubMed

Garcia, Gustavo A; Krüger, Julia; Gans, Bérenger; Falvo, Cyril; Coudert, Laurent H; Loison, Jean-Christophe

2017-07-07

We present the photoelectron spectroscopy of four radical species, CH x CN (x = 0-2) and CNC, formed in a microwave discharge flow-tube reactor by consecutive H abstractions from CH 3 CN (CH x CN + F → CH x-1 CN + HF (x = 1-3)). The spectra were obtained combining tunable vacuum ultraviolet synchrotron radiation with double imaging electron/ion coincidence techniques, which yielded mass-selected threshold photoelectron spectra. The results obtained for H 2 CCN complement existing ones while for the other radicals the data represent the first observation of their (single-photon) ionizing transitions. In the case of H 2 CCN, Franck-Condon calculations have been performed in order to assign the vibrational structure of the X + 1 A 1 ←X 2 B 1 ionizing transition. A similar treatment for the HCCN, CCN, and CNC radicals appeared to be more complicated mainly because a Renner-Teller effect strongly affects the vibrational levels of the ground electronic state of the HCCN + , CCN, and CNC species. Nevertheless, the first adiabatic ionization energies of these radicals are reported and compared to our ab initio calculated values, leading to new values for enthalpies of formation (Δ f H 298 0 (HCCN + (X 2 A ' ))=1517±12kJmol -1 ,Δ f H 298 0 (CCN(X 2 Π))=682±13kJmol -1 , and Δ f H 298 0 (CNC(X 2 Πg))=676±12kJmol -1 ), which are of fundamental importance for astrochemistry.

A Novel Role for VICKZ Proteins in Maintaining Epithelial Integrity during Embryogenesis

PubMed Central

Carmel, Michal Shoshkes; Kahane, Nitza; Oberman, Froma; Miloslavski, Rachel; Sela-Donenfeld, Dalit; Kalcheim, Chaya; Yisraeli, Joel K.

2015-01-01

Background VICKZ (IGF2BP1,2,3/ZBP1/Vg1RBP/IMP1,2,3) proteins bind RNA and help regulate many RNA-mediated processes. In the midbrain region of early chick embryos, VICKZ is expressed in the neural folds and along the basal surface of the neural epithelium, but, upon neural tube closure, is down-regulated in prospective cranial neural crest (CNC) cells, concomitant with their emigration and epithelial-to-mesenchymal transition (EMT). Electroporation of constructs that modulate cVICKZ expression demonstrates that this down-regulation is both necessary and sufficient for CNC EMT. These results suggest that VICKZ down-regulation in CNC cell-autonomously promotes EMT and migration. Reduction of VICKZ throughout the embryo, however, inhibits CNC migration non-cell-autonomously, as judged by transplantation experiments in Xenopus embryos. Results and Conclusions Given the positive role reported for VICKZ proteins in promoting cell migration of chick embryo fibroblasts and many types of cancer cells, we have begun to look for specific mRNAs that could mediate context-specific differences. We report here that the laminin receptor, integrin alpha 6, is down-regulated in the dorsal neural tube when CNC cells emigrate, this process is mediated by cVICKZ, and integrin alpha 6 mRNA is found in VICKZ ribonucleoprotein complexes. Significantly, prolonged inhibition of cVICKZ in either the neural tube or the nascent dermomyotome sheet, which also dynamically expresses cVICKZ, induces disruption of these epithelia. These data point to a previously unreported role for VICKZ in maintaining epithelial integrity. PMID:26317350

Immunoadjuvant Chemotherapy of Visceral Leishmaniasis in Hamsters Using Amphotericin B-Encapsulated Nanoemulsion Template-Based Chitosan Nanocapsules

PubMed Central

Asthana, Shalini; Jaiswal, Anil K.; Gupta, Pramod K.; Pawar, Vivek K.; Dube, Anuradha

2013-01-01

The accessible treatment options for life-threatening neglected visceral leishmaniasis (VL) disease have problems with efficacy, stability, adverse effects, and cost, making treatment a complex issue. Here we formulated nanometric amphotericin B (AmB)-encapsulated chitosan nanocapsules (CNC-AmB) using a polymer deposition technique mediated by nanoemulsion template fabrication. CNC-AmB exhibited good steric stability in vitro, where the chitosan content was found to be efficient at preventing destabilization in the presence of protein and Ca2+. A toxicity study on the model cell line J774A and erythrocytes revealed that CNC-AmB was less toxic than commercialized AmB formulations such as Fungizone and AmBisome. The results of in vitro (macrophage-amastigote system; 50% inhibitory concentration [IC50], 0.19 ± 0.04 μg AmB/ml) and in vivo (Leishmania donovani-infected hamsters; 86.1% ± 2.08% parasite inhibition) experiments in conjunction with effective internalization by macrophages illustrated the efficacy of CNC-AmB at augmenting antileishmanial properties. Quantitative mRNA analysis by real-time PCR (RT-PCR) showed that the improved effect was synergized with the upregulation of tumor necrosis factor alpha (TNF-α), interleukin-12 (IL-12), and inducible nitric oxide synthase and with the downregulation of transforming growth factor β (TGF-β), IL-10, and IL-4. These research findings suggest that a cost-effective CNC-AmB immunoadjuvant chemotherapeutic delivery system could be a viable alternative to the current high-cost commercial lipid-based formulations. PMID:23357762

Open-systems Architecture of a Standardized Command Interface Chip-set for Switching and Control of a Spacecraft Power Bus

NASA Technical Reports Server (NTRS)

Ruiz, B. Ian; Burke, Gary R.; Lung, Gerald; Whitaker, William D.; Nowicki, Robert M.

2004-01-01

This viewgraph presentation reviews the architecture of the The CIA-AlA chip-set is a set of mixed-signal ASICs that provide a flexible high level interface between the spacecraft's command and data handling (C&DH) electronics and lower level functions in other spacecraft subsystems. Due to the open-systems architecture of the chip-set including an embedded micro-controller a variety of applications are possible. The chip-set was developed for the missions to the outer planets. The chips were developed to provide a single solution for both the switching and regulation of a spacecraft power bus. The Open-Systems Architecture allows for other powerful applications.

Learning Control: Sense-Making, CNC Machines, and Changes in Vocational Training for Industrial Work

ERIC Educational Resources Information Center

Berner, Boel

2009-01-01

The paper explores how novices in school-based vocational training make sense of computerized numerical control (CNC) machines. Based on two ethnographic studies in Swedish schools, one from the early 1980s and one from 2006, it analyses change and continuity in the cognitive, social, and emotional processes of learning how to become a machine…

Manufacturing Laboratory for Next Generation Engineers

DTIC Science & Technology

2013-12-16

automated CNC machines, rapid prototype systems, robotic assembly systems, metrology , and non-traditional systems such as a waterjet cutter, EDM machine...CNC machines, rapid prototype systems, robotic assembly systems, metrology , and non-traditional systems such as a waterjet cutter, EDM machine, plasma...System Metrology and Quality Control Equipment - This area already had a CMM and other well known quality control instrumentation. It has been enhanced

CNC Turning Center Operations and Prove Out. Computer Numerical Control Operator/Programmer. 444-334.

ERIC Educational Resources Information Center

Skowronski, Steven D.

This student guide provides materials for a course designed to instruct the student in the recommended procedures used when setting up tooling and verifying part programs for a two-axis computer numerical control (CNC) turning center. The course consists of seven units. Unit 1 discusses course content and reviews and demonstrates set-up procedures…

Advanced CNC and CAM Series. Educational Resources for the Machine Tool Industry. Course Syllabi, Instructor's Handbook [and] Student Laboratory Manual.

ERIC Educational Resources Information Center

Texas State Technical Coll. System, Waco.

This package consists of course syllabi, an instructor's handbook, and student laboratory manual for a 1-year vocational training program to prepare students for entry-level positions as advanced computer numerical control (CNC) and computer-assisted manufacturing (CAM) technicians.. The program was developed through a modification of the DACUM…

Basic CNC Operation. Training Workbook [and] Assessment and Training Guide [and] Hands-on Assessment.

ERIC Educational Resources Information Center

Anoka-Hennepin Technical Coll., Minneapolis, MN.

This workbook is intended for students taking a course in basic computer numerical control (CNC) operation that was developed during a project to retrain defense industry workers at risk of job loss or dislocation because of conversion of the defense industry. The workbook contains daily training guides for each of the course's 13 sessions. Among…

Bmp signaling regulates a dose-dependent transcriptional program to control facial skeletal development.

PubMed

Bonilla-Claudio, Margarita; Wang, Jun; Bai, Yan; Klysik, Elzbieta; Selever, Jennifer; Martin, James F

2012-02-01

We performed an in depth analysis of Bmp4, a critical regulator of development, disease, and evolution, in cranial neural crest (CNC). Conditional Bmp4 overexpression, using a tetracycline-regulated Bmp4 gain-of-function allele, resulted in facial skeletal changes that were most dramatic after an E10.5 Bmp4 induction. Expression profiling uncovered a signature of Bmp4-induced genes (BIG) composed predominantly of transcriptional regulators that control self-renewal, osteoblast differentiation and negative Bmp autoregulation. The complimentary experiment, CNC inactivation of Bmp2, Bmp4 and Bmp7, resulted in complete or partial loss of multiple CNC-derived skeletal elements, revealing a crucial requirement for Bmp signaling in membranous bone and cartilage development. Importantly, the BIG signature was reduced in Bmp loss-of-function mutants, indicating Bmp-regulated target genes are modulated by Bmp dose. Chromatin immunoprecipitation (ChIP) revealed a subset of the BIG signature, including Satb2, Smad6, Hand1, Gadd45γ and Gata3, that was bound by Smad1/5 in the developing mandible, revealing direct Smad-mediated regulation. These data support the hypothesis that Bmp signaling regulates craniofacial skeletal development by balancing self-renewal and differentiation pathways in CNC progenitors.

Effect of drying on the porosity of the hydroxyapatite and cellulose nata de coco compositeas bone graft candidate

NASA Astrophysics Data System (ADS)

Anitasari, S.; Mu’ti, A.; Hutahaean, YO

2018-04-01

Bone graft is used to replace bone parts damaged by illness and accident. As a bone replacement material, the bone graft should be able to stimulate the process of the osteogenesis. The process of osteogenesis is influenced by the osteoconductive properties of a biomaterial, that porosity affects this process. The shells of blood scallop (Anadaragranosa) are producing hydroxyapatite (HAp),having high compressive strength, biocompatibility and osteoconductive properties, but low porosity while cellulose nata de coco (Cnc) have low compressive strength but high porosity. Therefore, the combination of two biomaterials are expected to produce composite that have high osteoconductive properties. The purpose of this research wasknowing the porosity of HAp/Cnc composite which wasbeingprecipitated for 5 hours, 15 hours, 25 hours and wasdried for 24 hours, 48 hours and 72 hours. This research usedwise drop technique to synthesis HAp powder and cellulose immersion technique for synthesis of HAp/Cnc. Results of this research, there was difference in porosity between HAp/Cnc that was precipitated for 5 hours, 15 hours and 25 hours, as well as was dried for 1 day, 2 days and 3 days. The conclusion, the synthesis of HAp/Cncwasuseful as bone graft candidate.

Counting particles emitted by stratospheric aircraft and measuring size of particles emitted by stratospheric aircraft

NASA Technical Reports Server (NTRS)

Wilson, James Charles

1994-01-01

The ER-2 condensation nuclei counter (CNC) has been modified to reduce the diffusive losses of particles within the instrument. These changes have been successful in improving the counting efficiency of small particles at low pressures. Two techniques for measuring the size distributions of particles with diameters less than 0.17 micrometers have been evaluated. Both of these methods, the differential mobility analyzer (DMA) and the diffusion battery, have fundamental problems that limit their usefulness for stratospheric applications. We cannot recommend either for this application. Newly developed, alternative methods for measuring small particles include inertial separation with a low-loss critical orifice and thin-plate impactor device. This technique is now used to collect particles in the multisample aerosol collector housed in the ER-2 CNC-2, and shows some promise for particle size measurements when coupled with a CNC as a counting device. The modified focused-cavity aerosol spectrometer (FCAS) can determine the size distribution of particles with ambient diameters as small as about 0.07 micrometers. Data from this instrument indicates the presence of a nuclei mode when CNC-2 indicates high concentrations of particles, but cannot resolve important parameters of the distribution.

Cellulose nanoparticles as modifiers for rheology and fluid loss in bentonite water-based fluids.

PubMed

Li, Mei-Chun; Wu, Qinglin; Song, Kunlin; Qing, Yan; Wu, Yiqiang

2015-03-04

Rheological and filtration characteristics of drilling fluids are considered as two critical aspects to ensure the success of a drilling operation. This research demonstrates the effectiveness of cellulose nanoparticles (CNPs), including microfibrillated cellulose (MFC) and cellulose nanocrystals (CNCs) in enhancing the rheological and filtration performances of bentonite (BT) water-based drilling fluids (WDFs). CNCs were isolated from MFC through sulfuric acid hydrolysis. In comparison with MFC, the resultant CNCs had much smaller dimensions, more negative surface charge, higher stability in aqueous solutions, lower viscosity, and less evident shear thinning behavior. These differences resulted in the distinctive microstructures between MFC/BT- and CNC/BT-WDFs. A typical "core-shell" structure was created in CNC/BT-WDFs due to the strong surface interactions among BT layers, CNCs, and immobilized water molecules. However, a similar structure was not formed in MFC/BT-WDFs. As a result, CNC/BT-WDFs had superior rheological properties, higher temperature stability, less fluid loss volume, and thinner filter cakes than BT and MFC/BT-WDFs. Moreover, the presence of polyanionic cellulose (PAC) further improved the rheological and filtration performances of CNC/BT-WDFs, suggesting a synergistic effect between PAC and CNCs.

OpenCL: A Parallel Programming Standard for Heterogeneous Computing Systems.

PubMed

Stone, John E; Gohara, David; Shi, Guochun

2010-05-01

We provide an overview of the key architectural features of recent microprocessor designs and describe the programming model and abstractions provided by OpenCL, a new parallel programming standard targeting these architectures.

NDE Process Development Specification for SRB Composite Nose Cap

NASA Technical Reports Server (NTRS)

Suits, M.

1999-01-01

The Shuttle Upgrade program is a continuing improvement process to enable the Space Shuttle to be an effective space transportation vehicle for the next few decades. The Solid Rocket Booster (SRB), as a component of that system, is currently undergoing such an improvement. Advanced materials, such as composites, have given us a chance to improve performance and to reduce weight. The SRB Composite Nose Cap (CNC) program aims to replace the current aluminum nose cap, which is coated with a Thermal Protection System and poses a possible debris hazard, with a lighter, stronger, CNC. For the next 2 years, this program will evaluate the design, material selection, properties, and verification of the CNC. This particular process specification cites the methods and techniques for verifying the integrity of such a nose cap with nondestructive evaluation.

Experimental and numerical study on optimization of the single point incremental forming of AINSI 304L stainless steel sheet

NASA Astrophysics Data System (ADS)

Saidi, B.; Giraud-Moreau, L.; Cherouat, A.; Nasri, R.

2017-09-01

AINSI 304L stainless steel sheets are commonly formed into a variety of shapes for applications in the industrial, architectural, transportation and automobile fields, it’s also used for manufacturing of denture base. In the field of dentistry, there is a need for personalized devises that are custom made for the patient. The single point incremental forming process is highly promising in this area for manufacturing of denture base. The single point incremental forming process (ISF) is an emerging process based on the use of a spherical tool, which is moved along CNC controlled tool path. One of the major advantages of this process is the ability to program several punch trajectories on the same machine in order to obtain different shapes. Several applications of this process exist in the medical field for the manufacturing of personalized titanium prosthesis (cranial plate, knee prosthesis...) due to the need of product customization to each patient. The objective of this paper is to study the incremental forming of AISI 304L stainless steel sheets for future applications in the dentistry field. During the incremental forming process, considerable forces can occur. The control of the forming force is particularly important to ensure the safe use of the CNC milling machine and preserve the tooling and machinery. In this paper, the effect of four different process parameters on the maximum force is studied. The proposed approach consists in using an experimental design based on experimental results. An analysis of variance was conducted with ANOVA to find the input parameters allowing to minimize the maximum forming force. A numerical simulation of the incremental forming process is performed with the optimal input process parameters. Numerical results are compared with the experimental ones.

A reference architecture for integrated EHR in Colombia.

PubMed

de la Cruz, Edgar; Lopez, Diego M; Uribe, Gustavo; Gonzalez, Carolina; Blobel, Bernd

2011-01-01

The implementation of national EHR infrastructures has to start by a detailed definition of the overall structure and behavior of the EHR system (system architecture). Architectures have to be open, scalable, flexible, user accepted and user friendly, trustworthy, based on standards including terminologies and ontologies. The GCM provides an architectural framework created with the purpose of analyzing any kind of system, including EHR system´s architectures. The objective of this paper is to propose a reference architecture for the implementation of an integrated EHR in Colombia, based on the current state of system´s architectural models, and EHR standards. The proposed EHR architecture defines a set of services (elements) and their interfaces, to support the exchange of clinical documents, offering an open, scalable, flexible and semantically interoperable infrastructure. The architecture was tested in a pilot tele-consultation project in Colombia, where dental EHR are exchanged.

OpenCL: A Parallel Programming Standard for Heterogeneous Computing Systems

PubMed Central

Stone, John E.; Gohara, David; Shi, Guochun

2010-01-01

We provide an overview of the key architectural features of recent microprocessor designs and describe the programming model and abstractions provided by OpenCL, a new parallel programming standard targeting these architectures. PMID:21037981

National Airspace System (NAS) open system architecture and protocols

DOT National Transportation Integrated Search

2003-08-14

This standard establishes the open systems data communications architecture and authorized protocol standards for the National Airspace System (NAS). The NAS will consist of various types of processors and communications networks procured from a vari...

Modular Open System Architecture for Reducing Contamination Risk in the Space and Missile Defense Supply Chain

NASA Technical Reports Server (NTRS)

Seasly, Elaine

2015-01-01

To combat contamination of physical assets and provide reliable data to decision makers in the space and missile defense community, a modular open system architecture for creation of contamination models and standards is proposed. Predictive tools for quantifying the effects of contamination can be calibrated from NASA data of long-term orbiting assets. This data can then be extrapolated to missile defense predictive models. By utilizing a modular open system architecture, sensitive data can be de-coupled and protected while benefitting from open source data of calibrated models. This system architecture will include modules that will allow the designer to trade the effects of baseline performance against the lifecycle degradation due to contamination while modeling the lifecycle costs of alternative designs. In this way, each member of the supply chain becomes an informed and active participant in managing contamination risk early in the system lifecycle.

Squishy nanotraps: hybrid cellulose nanocrystal-zirconium metallogels for controlled trapping of biomacromolecules.

PubMed

Sheikhi, A; van de Ven, T G M

2017-08-11

A brick-and-mortar-like ultrasoft nanocomposite metallogel is formed by crosslinking cellulose nanocrystals (CNC) with ammonium zirconium carbonate (AZC) to trap and reconfigure dextran, a model biomacromolecule. The bricks (CNC) reinforce the metallogel, compete with dextran in reacting with AZC, and decouple long-time dextran dynamics from network formation, while the mortar (AZC) imparts bimodality to the dextran diffusion.

Nozzles for Focusing Aerosol Particles

DTIC Science & Technology

2009-10-01

Fabrication of the nozzle with the desired shape was accomplished using EDM technology. First, a copper tungsten electrode was turned on a CNC lathe . The...small (0.9-mm diameter). The external portions of the nozzles were machined in a more conventional manner using computer numerical control ( CNC ... lathes and milling machines running programs written by computer aided machining (CAM) software. The close tolerance of concentricity of the two

Evaluation of metal-ceramic bond characteristics of three dental Co-Cr alloys prepared with different fabrication techniques.

PubMed

Wang, Hongmei; Feng, Qing; Li, Ning; Xu, Sheng

2016-12-01

Limited information is available regarding the metal-ceramic bond strength of dental Co-Cr alloys fabricated by casting (CAST), computer numerical control (CNC) milling, and selective laser melting (SLM). The purpose of this in vitro study was to evaluate the metal-ceramic bond characteristics of 3 dental Co-Cr alloys fabricated by casting, computer numerical control milling, and selective laser melting techniques using the 3-point bend test (International Organization for Standardization [ISO] standard 9693). Forty-five specimens (25×3×0.5 mm) made of dental Co-Cr alloys were prepared by CAST, CNC milling, and SLM techniques. The morphology of the oxidation surface of metal specimens was evaluated by scanning electron microscopy (SEM). After porcelain application, the interfacial characterization was evaluated by SEM equipped with energy-dispersive spectrometry (EDS) analysis, and the metal-ceramic bond strength was assessed with the 3-point bend test. Failure type and elemental composition on the debonding interface were assessed by SEM/EDS. The bond strength was statistically analyzed by 1-way ANOVA and Tukey honest significant difference test (α=.05). The oxidation surfaces of the CAST, CNC, and SLM groups were different. They were porous in the CAST group but compact and irregular in the CNC and SLM groups. The metal-ceramic interfaces of the SLM and CNC groups showed excellent combination compared with those of the CAST group. The bond strength was 37.7 ±6.5 MPa for CAST, 43.3 ±9.2 MPa for CNC, and 46.8 ±5.1 MPa for the SLM group. Statistically significant differences were found among the 3 groups tested (P=.028). The debonding surfaces of all specimens exhibited cohesive failure mode. The oxidation surface morphologies and thicknesses of dental Co-Cr alloys are dependent on the different fabrication techniques used. The bond strength of all 3 groups exceed the minimum acceptable value of 25 MPa recommended by ISO 9693; hence, dental Co-Cr alloy fabricated with the SLM techniques could be a promising alternative for metal ceramic restorations. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Mechanical oscillatory behavior of a C60 fullerene tunneling through open carbon nanocones

NASA Astrophysics Data System (ADS)

Sadeghi, F.; Ansari, R.

2017-07-01

This paper deals with the mechanical oscillatory behavior of a C60 fullerene inside open carbon nanocones (CNCs). The fullerene molecule is assumed to enter the nanocone through its small end or wide end. Following our previously published study, semi-analytical expressions for the evaluation of vdW interactions are presented which facilitate obtaining a formula for oscillation frequency. The equation of motion is numerically solved to attain the time histories of separation distance and velocity of the fullerene molecule. Based on the conservation of the mechanical energy law, a new semi-analytical formula is also derived to accurately evaluate the oscillation frequency of the system. With respect to the present formulation, a detailed parametric study is conducted to gain an insight into the effects of both geometrical parameters (small-end radius, wide-end radius and vertex angle of nanocone) and initial conditions (initial separation distance and initial velocity) on the oscillatory behavior of C60 fullerene-open CNC oscillators. For given geometrical parameters and initial conditions, it is shown that higher oscillation frequencies can be achieved when the fullerene molecule enters the open nanocone through its small end.

An open architecture motion controller

NASA Technical Reports Server (NTRS)

Rossol, Lothar

1994-01-01

Nomad, an open architecture motion controller, is described. It is formed by a combination of TMOS, C-WORKS, and other utilities. Nomad software runs in a UNIX environment and provides for sensor-controlled robotic motions, with user replaceable kinematics. It can also be tailored for highly specialized applications. Open controllers such as Nomad should have a major impact on the robotics industry.

Director, Platform and Audience.

ERIC Educational Resources Information Center

Meyer, Richard D.

The open stage is discussed both as architecture and as part of a new theatrical style. In reference to use of the open stage, emphasis is given to specifics with which the director must deal, to special problems of the actor, to the approach to blocking a play, and to the open stage as "theatrical experience". The architectural advantage of the…

Putting Teeth into Open Architectures: Infrastructure for Reducing the Need for Retesting

DTIC Science & Technology

2007-04-30

the test and evaluation team. This paper outlines new approaches to quality assurance and testing that are better suited for providing...reconfiguration. Testing of reusable subsystems is also subject to the above considerations and, similarly, requires new methods for effectively achieving...architectural model. Thus, fully realizing the open architecture vision requires a new paradigm for test and evaluation. We propose such a

GBU-X bounding requirements for highly flexible munitions

NASA Astrophysics Data System (ADS)

Bagby, Patrick T.; Shaver, Jonathan; White, Reed; Cafarelli, Sergio; Hébert, Anthony J.

2017-04-01

This paper will present the results of an investigation into requirements for existing software and hardware solutions for open digital communication architectures that support weapon subsystem integration. The underlying requirements of such a communication architecture would be to achieve the lowest latency possible at a reasonable cost point with respect to the mission objective of the weapon. The determination of the latency requirements of the open architecture software and hardware were derived through the use of control system and stability margins analyses. Studies were performed on the throughput and latency of different existing communication transport methods. The two architectures that were tested in this study include Data Distribution Service (DDS) and Modular Open Network Architecture (MONARCH). This paper defines what levels of latency can be achieved with current technology and how this capability may translate to future weapons. The requirements moving forward within communications solutions are discussed.

A comparison of fit of CNC-milled titanium and zirconia frameworks to implants.

PubMed

Abduo, Jaafar; Lyons, Karl; Waddell, Neil; Bennani, Vincent; Swain, Michael

2012-05-01

Computer numeric controlled (CNC) milling was proven to be predictable method to fabricate accurately fitting implant titanium frameworks. However, no data are available regarding the fit of CNC-milled implant zirconia frameworks. To compare the precision of fit of implant frameworks milled from titanium and zirconia and relate it to peri-implant strain development after framework fixation. A partially edentulous epoxy resin models received two Branemark implants in the areas of the lower left second premolar and second molar. From this model, 10 identical frameworks were fabricated by mean of CNC milling. Half of them were made from titanium and the other half from zirconia. Strain gauges were mounted close to the implants to qualitatively and quantitatively assess strain development as a result of framework fitting. In addition, the fit of the framework implant interface was measured using an optical microscope, when only one screw was tightened (passive fit) and when all screws were tightened (vertical fit). The data was statistically analyzed using the Mann-Whitney test. All frameworks produced measurable amounts of peri-implant strain. The zirconia frameworks produced significantly less strain than titanium. Combining the qualitative and quantitative information indicates that the implants were under vertical displacement rather than horizontal. The vertical fit was similar for zirconia (3.7 µm) and titanium (3.6 µm) frameworks; however, the zirconia frameworks exhibited a significantly finer passive fit (5.5 µm) than titanium frameworks (13.6 µm). CNC milling produced zirconia and titanium frameworks with high accuracy. The difference between the two materials in terms of fit is expected to be of minimal clinical significance. The strain developed around the implants was more related to the framework fit rather than framework material. © 2011 Wiley Periodicals, Inc.

Normative data for the Maryland CNC Test.

PubMed

Mendel, Lisa Lucks; Mustain, William D; Magro, Jessica

2014-09-01

The Maryland consonant-vowel nucleus-consonant (CNC) Test is routinely used in Veterans Administration medical centers, yet there is a paucity of published normative data for this test. The purpose of this study was to provide information on the means and distribution of word-recognition scores on the Maryland CNC Test as a function of degree of hearing loss for a veteran population. A retrospective, descriptive design was conducted. The sample consisted of records from veterans who had Compensation and Pension (C&P) examinations at a Veterans Administration medical center (N = 1,760 ears). Audiometric records of veterans who had C&P examinations during a 10 yr period were reviewed, and the pure-tone averages (PTA4) at four frequencies (1000, 2000, 3000, and 4000 Hz) were documented. The maximum word-recognition score (PBmax) was determined from the performance-intensity functions obtained using the Maryland CNC Test. Correlations were made between PBmax and PTA4. A wide range of word-recognition scores were obtained at all levels of PTA4 for this population. In addition, a strong negative correlation between the PBmax and the PTA4 was observed, indicating that as PTA4 increased, PBmax decreased. Word-recognition scores decreased significantly as hearing loss increased beyond a mild hearing loss. Although threshold was influenced by age, no statistically significant relationship was found between word-recognition score and the age of the participants. RESULTS from this study provide normative data in table and figure format to assist audiologists in interpreting patient results on the Maryland CNC test for a veteran population. These results provide a quantitative method for audiologists to use to interpret word-recognition scores based on pure-tone hearing loss. American Academy of Audiology.

Carbon and oxygen abundances in cool metal-rich exoplanet hosts: A case study of the C/O ratio of 55 Cancri

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

Teske, Johanna K.; Cunha, Katia; Schuler, Simon C.

2013-12-01

The super-Earth exoplanet 55 Cnc e, the smallest member of a five-planet system, has recently been observed to transit its host star. The radius estimates from transit observations, coupled with spectroscopic determinations of mass, provide constraints on its interior composition. The composition of exoplanetary interiors and atmospheres are particularly sensitive to elemental C/O ratio, which to first order can be estimated from the host stars. Results from a recent spectroscopic study analyzing the 6300 Å [O I] line and two C I lines suggest that 55 Cnc has a carbon-rich composition (C/O = 1.12 ± 0.09). However, oxygen abundances derivedmore » using the 6300 Å [O I] line are highly sensitive to a Ni I blend, particularly in metal-rich stars such as 55 Cnc ([Fe/H] =0.34 ± 0.18). Here, we further investigate 55 Cnc's composition by deriving the carbon and oxygen abundances from these and additional C and O absorption features. We find that the measured C/O ratio depends on the oxygen lines used. The C/O ratio that we derive based on the 6300 Å [O I] line alone is consistent with the previous value. Yet, our investigation of additional abundance indicators results in a mean C/O ratio of 0.78 ± 0.08. The lower C/O ratio of 55 Cnc determined here may place this system at the sensitive boundary between protoplanetary disk compositions giving rise to planets with high (>0.8) versus low (<0.8) C/O ratios. This study illustrates the caution that must applied when determining planet host star C/O ratios, particularly in cool, metal-rich stars.« less

New MOST Photometry of the 55 Cancri System

NASA Astrophysics Data System (ADS)

Dragomir, Diana; Matthews, Jaymie M.; Winn, Joshua N.; Rowe, Jason F.

2014-04-01

Since the discovery of its transiting nature, the super-Earth 55 Cnc e has become one of the most enthusiastically studied exoplanets, having been observed spectroscopically and photometrically, in the ultraviolet, optical and infrared regimes. To this rapidly growing data set, we contribute 42 days of new, nearly continuous MOST photometry of the 55 Cnc system. Our analysis of these observations together with the discovery photometry obtained in 2011 allows us to determine the planetary radius (1.990+0.084 -0.080) and orbital period (0.7365417+0.0000025 -0.0000028) of 55 Cnc e with unprecedented precision. We also followed up on the out-of-transit phase variation first observed in the 2011 photometry, and set an upper limit on the depth of the planet's secondary eclipse, leading to an upper limit on its geometric albedo of 0.6.

Improved oxidation resistance of organic/inorganic composite atomic layer deposition coated cellulose nanocrystal aerogels

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

Smith, Sean W.; Matthews, David J.; Conley, John F., E-mail: jconley@eecs.oregonstate.edu

2014-07-01

Cellulose nanocrystal (CNC) aerogels are coated with thin conformal layers of Al{sub 2}O{sub 3} using atomic layer deposition to form hybrid organic/inorganic nanocomposites. Electron probe microanalysis and scanning electron microscopy analysis indicated the Al{sub 2}O{sub 3} penetrated more than 1500 μm into the aerogel for extended precursor pulse and exposure/purge times. The measured profile of coated fiber radius versus depth from the aerogel surface agrees well with simulations of precursor penetration depth in modeled aerogel structures. Thermogravimetric analysis shows that Al{sub 2}O{sub 3} coated CNC aerogel nanocomposites do not show significant thermal degradation below 295 °C as compared with 175 °C for uncoatedmore » CNC aerogels, an improvement of over 100 °C.« less

A 60-NIGHT Campaign on Dwarf Novae - Part One - Photometric Variability of Su-Ursae and Yz-Cancri

NASA Astrophysics Data System (ADS)

van Paradijs, J.; Charles, P. A.; Harlaftis, E. T.; Arevalo, M. J.; Baruch, J. E. F.; Callanan, P. J.; Casares, J.; Dhillon, V. S.; Gimenez, A.; Gonzalez, R.; Matinez-Pais, I. G.; Jones, D. H. P.; Hassall, B. J. M.; Hellier, C.; Kidger, M. R.; Lazaro, C.; Marsh, T. R.; Mason, K. O.; Mukai, K.; Naylor, T.; Reglero, V.; Rutten, R. G. M.; Smith, R. C.

1994-04-01

A 60-night campaign on SU UMa, YZ Cnc and some secondary targets was carried out during 1988 December and 1989 January at the Observatorio del Roque de Los Muchachos (the 1988 International Time Project). The aim was to study the behaviour of these dwarf novae through their outburst cycle. Here we present the overall light curves of the main targets, SU UMa and YZ Cnc, which show that the optical fluxes continue to decrease after the end of the outburst. For YZ Cnc we find that, during quiescence, orbital variability is present, which may be interpreted as modulation caused by the bright-spot region. Near the end of an outburst, a weak, sinusoidal variation is observed; we discuss the possibility that this arises either from the secondary star or the accretion disc.

Absolute and geometric parameters of contact binary GW Cnc

NASA Astrophysics Data System (ADS)

Gürol, B.; Gökay, G.; Saral, G.; Gürsoytrak, S. H.; Cerit, S.; Terzioğlu, Z.

2016-07-01

We present the results of our investigation on the geometrical and physical parameters of the W UMa type binary system GW Cnc. We analyzed the photometric data obtained in 2010 and 2011 at Ankara University Observatory (AUO) and the spectroscopic data obtained in 2010 at TUBITAK National Observatory (TUG) by using the Wilson-Devinney (2013 revision) code to obtain the absolute and geometrical parameters. We derived masses and radii of the eclipsing system to be M1 = 0.257M⊙ , M2 = 0.971M⊙ , R1 = 0.526R⊙ and R2 = 0.961R⊙ with an orbital inclination i(∘) = 83.38 ± 0.25 and we determined the GW Cnc system to be a W-type W UMa over-contact binary with a mass ratio of q = 3.773 ± 0.007 .

Architecture for Survivable Systems Processing (ASSP). Technology benefits for Open System Interconnects

NASA Technical Reports Server (NTRS)

Wood, Richard J.

1992-01-01

The Architecture for Survivable Systems Processing (ASSP) program is a two phase program whose objective is the derivation, specification, development and validation of an open system architecture capable of supporting advanced processing needs of space, ground, and launch vehicle operations. The output of the first phase is a set of hardware and software standards and specifications defining this architecture at three levels. The second phase will validate these standards and develop the technology necessary to achieve strategic hardness, packaging density, throughput requirements, and interoperability/interchangeability.

Making sense of mobile health data: an open architecture to improve individual- and population-level health.

PubMed

Chen, Connie; Haddad, David; Selsky, Joshua; Hoffman, Julia E; Kravitz, Richard L; Estrin, Deborah E; Sim, Ida

2012-08-09

Mobile phones and devices, with their constant presence, data connectivity, and multiple intrinsic sensors, can support around-the-clock chronic disease prevention and management that is integrated with daily life. These mobile health (mHealth) devices can produce tremendous amounts of location-rich, real-time, high-frequency data. Unfortunately, these data are often full of bias, noise, variability, and gaps. Robust tools and techniques have not yet been developed to make mHealth data more meaningful to patients and clinicians. To be most useful, health data should be sharable across multiple mHealth applications and connected to electronic health records. The lack of data sharing and dearth of tools and techniques for making sense of health data are critical bottlenecks limiting the impact of mHealth to improve health outcomes. We describe Open mHealth, a nonprofit organization that is building an open software architecture to address these data sharing and "sense-making" bottlenecks. Our architecture consists of open source software modules with well-defined interfaces using a minimal set of common metadata. An initial set of modules, called InfoVis, has been developed for data analysis and visualization. A second set of modules, our Personal Evidence Architecture, will support scientific inferences from mHealth data. These Personal Evidence Architecture modules will include standardized, validated clinical measures to support novel evaluation methods, such as n-of-1 studies. All of Open mHealth's modules are designed to be reusable across multiple applications, disease conditions, and user populations to maximize impact and flexibility. We are also building an open community of developers and health innovators, modeled after the open approach taken in the initial growth of the Internet, to foster meaningful cross-disciplinary collaboration around new tools and techniques. An open mHealth community and architecture will catalyze increased mHealth efficiency, effectiveness, and innovation.

Making Sense of Mobile Health Data: An Open Architecture to Improve Individual- and Population-Level Health

PubMed Central

Chen, Connie; Haddad, David; Selsky, Joshua; Hoffman, Julia E; Kravitz, Richard L; Estrin, Deborah E

2012-01-01

Mobile phones and devices, with their constant presence, data connectivity, and multiple intrinsic sensors, can support around-the-clock chronic disease prevention and management that is integrated with daily life. These mobile health (mHealth) devices can produce tremendous amounts of location-rich, real-time, high-frequency data. Unfortunately, these data are often full of bias, noise, variability, and gaps. Robust tools and techniques have not yet been developed to make mHealth data more meaningful to patients and clinicians. To be most useful, health data should be sharable across multiple mHealth applications and connected to electronic health records. The lack of data sharing and dearth of tools and techniques for making sense of health data are critical bottlenecks limiting the impact of mHealth to improve health outcomes. We describe Open mHealth, a nonprofit organization that is building an open software architecture to address these data sharing and “sense-making” bottlenecks. Our architecture consists of open source software modules with well-defined interfaces using a minimal set of common metadata. An initial set of modules, called InfoVis, has been developed for data analysis and visualization. A second set of modules, our Personal Evidence Architecture, will support scientific inferences from mHealth data. These Personal Evidence Architecture modules will include standardized, validated clinical measures to support novel evaluation methods, such as n-of-1 studies. All of Open mHealth’s modules are designed to be reusable across multiple applications, disease conditions, and user populations to maximize impact and flexibility. We are also building an open community of developers and health innovators, modeled after the open approach taken in the initial growth of the Internet, to foster meaningful cross-disciplinary collaboration around new tools and techniques. An open mHealth community and architecture will catalyze increased mHealth efficiency, effectiveness, and innovation. PMID:22875563

Feasibility of Underwater Friction Stir Welding of Hardenable Alloy Steel

DTIC Science & Technology

2010-12-01

Base Material CNC – Computer Numerical Controlled EDM – Electrical Discharge Machining FSP – Friction Stir Processing FSW – Friction Stir Welding...Hydrogen content was determined through vacuum hot extraction according to ASTM E 146-83. All other components were analyzed by direct current plasma ...emission spectroscopy according to ASTM E 1097-07. C. MICROSTRUCTURE ANALYSIS 1. Specimen Preparation A Charmilles Andrew EF630 CNC Wire EDM

Tailored and integrated production of carboxylated cellulose nanocrystals (CNC) with nanofibrils (CNF) through maleic acid hydrolysis

Treesearch

Ruibin Wang; Liheng Chen; J.Y. Zhu; Rendang Yang

2017-01-01

This study demonstrates the feasibility of tailored and integrated production of carboxylated cellulose nanocrystals (CNC) with nanofibrils (CNF) from bleached pulp fibers through hydrolysis using a recyclable dicarboxylic acid. Hydrolysis experiments were conducted using ranges of 15–75 wt% maleic acid concentrations, 60–120°C temperatures, and 5–300 min reaction...

Prosthetics & Orthotics Manufacturing Initiative (POMI)

DTIC Science & Technology

2012-12-21

the two materials. The rod was then put onto a lathe machine, allowing a thin sheet, with stripes of alternating materials, to be cut from the rod...tooling from. Mentis determined a method to use Aquacore, which involved machining blanks via CNC , followed by coating the mold to prevent resin...infusion into the mold. Mentis also attempted to use plaster combined with CNC machining, however, these molds did not survive the machining process

Approaching zero cellulose loss in cellulose nanocrystal (CNC) production: recovery and characterization of cellulosic solid residues (CSR) and CNC

Treesearch

Q.Q. Wang; J.Y. Zhu; R.S. Reiner; S.P. Verrill; U. Baxa; S.E. McNeil

2012-01-01

This study demonstrated the potential of simultaneously recovering cellulosic solid residues (CSR) and producing cellulose nanocrystals (CNCs) by strong sulfuric acid hydrolysis to minimize cellulose loss to near zero. A set of slightly milder acid hydrolysis conditions than that considered as “optimal” were used to significantly minimize the degradation of cellulose...

Polyelectrolyte brushes grafted from cellulose nanocrystals using Cu-mediated surface-initiated controlled radical polymerization.

PubMed

Majoinen, Johanna; Walther, Andreas; McKee, Jason R; Kontturi, Eero; Aseyev, Vladimir; Malho, Jani Markus; Ruokolainen, Janne; Ikkala, Olli

2011-08-08

Herein we report the synthesis of cellulose nanocrystals (CNCs) grafted with poly(acrylic acid) (PAA) chains of different lengths using Cu-mediated surface initiated-controlled radical polymerization (SI-CRP). First, poly(tert-butylacrylate) (PtBA) brushes were synthesized; then, subsequent acid hydrolysis was used to furnish PAA brushes tethered onto the CNC surfaces. The CNCs were chemically modified to create initiator moieties on the CNC surfaces using chemical vapor deposition (CVD) and continued in solvent phase in DMF. A density of initiator groups of 4.6 bromine ester groups/nm(2) on the CNC surface was reached, suggesting a dense functionalization and a promising starting point for the controlled/living radical polymerization. The SI-CRP of tert-butylacrylate proceeded in a well-controlled manner with the aid of added sacrificial initiator, yielding polymer brushes with polydispersity values typically well below 1.12. We calculated the polymer brush grafting density to almost 0.3 chains/nm(2), corresponding to high grafting densities and dense polymer brush formation on the nanocrystals. Successful rapid acid hydrolysis to remove the tert-butyl groups yielded pH-responsive PAA-polyelectrolyte brushes bound to the CNC surface. Individually dispersed rod-like nanoparticles with brushes of PtBA or PAA were clearly visualized by AFM and TEM imaging.

A liver enhancer in the fibrinogen gene cluster.

PubMed

Fort, Alexandre; Fish, Richard J; Attanasio, Catia; Dosch, Roland; Visel, Axel; Neerman-Arbez, Marguerite

2011-01-06

The plasma concentration of fibrinogen varies in the healthy human population between 1.5 and 3.5 g/L. Understanding the basis of this variability has clinical importance because elevated fibrinogen levels are associated with increased cardiovascular disease risk. To identify novel regulatory elements involved in the control of fibrinogen expression, we used sequence conservation and in silico-predicted regulatory potential to select 14 conserved noncoding sequences (CNCs) within the conserved block of synteny containing the fibrinogen locus. The regulatory potential of each CNC was tested in vitro using a luciferase reporter gene assay in fibrinogen-expressing hepatoma cell lines (HuH7 and HepG2). 4 potential enhancers were tested for their ability to direct enhanced green fluorescent protein expression in zebrafish embryos. CNC12, a sequence equidistant from the human fibrinogen alpha and beta chain genes, activates strong liver enhanced green fluorescent protein expression in injected embryos and their transgenic progeny. A transgenic assay in embryonic day 14.5 mouse embryos confirmed the ability of CNC12 to activate transcription in the liver. While additional experiments are necessary to prove the role of CNC12 in the regulation of fibrinogen, our study reveals a novel regulatory element in the fibrinogen locus that is active in the liver and may contribute to variable fibrinogen expression in humans.

Effect of Catnip Charcoal on the In Vivo Pharmacokinetics of the Main Alkaloids of Rhizoma Coptidis.

PubMed

He, Yanfei; Chen, Siyu; Yu, Hai; Zhu, Long; Liu, Yayun; Han, Chunyang; Liu, Cuiyan

2016-01-01

This study aims to explore the effect of catnip Nepeta cataria (CNC) charcoal on the pharmacokinetics of the main alkaloids of Rhizoma Coptidis in vivo. Twenty-four rabbits were randomly divided into four groups and given oral administration of an aqueous extract of Rhizoma Coptidis (RCAE), RCAE plus CNC, RCAE plus activated carbon (AC), or distilled water, respectively. Plasma samples were collected after administration. The concentrations of berberine, coptisine, palmatine, and epiberberine in plasma were measured by high-performance liquid chromatography (HPLC). The pharmacokinetics data were calculated using pharmacokinetic DAS 2.0 software. The results showed that the area under the concentration-time curve (AUC) of berberine increased, while the AUC of coptisine, palmatine, and epiberberine decreased in the rabbits that received RCAE plus CNC. Meanwhile, the AUC of berberine, coptisine, palmatine, and epiberberine decreased in the group given RCAE plus AC. The difference of main pharmacokinetics parameters among the four groups was significant (P < 0.05). This study showed that CNC improved the bioavailability of berberine in comparison to AC and prolonged its release in comparison to RCAE alone. However, it decreased the bioavailability of coptisine, palmatine, and epiberberine. In comparison, AC uniformly declined the bioavailability of berberine, coptisine, palmatine, and epiberberine.

Effect of Catnip Charcoal on the In Vivo Pharmacokinetics of the Main Alkaloids of Rhizoma Coptidis

PubMed Central

He, Yanfei; Chen, Siyu; Yu, Hai; Zhu, Long; Liu, Yayun; Han, Chunyang; Liu, Cuiyan

2016-01-01

This study aims to explore the effect of catnip Nepeta cataria (CNC) charcoal on the pharmacokinetics of the main alkaloids of Rhizoma Coptidis in vivo. Twenty-four rabbits were randomly divided into four groups and given oral administration of an aqueous extract of Rhizoma Coptidis (RCAE), RCAE plus CNC, RCAE plus activated carbon (AC), or distilled water, respectively. Plasma samples were collected after administration. The concentrations of berberine, coptisine, palmatine, and epiberberine in plasma were measured by high-performance liquid chromatography (HPLC). The pharmacokinetics data were calculated using pharmacokinetic DAS 2.0 software. The results showed that the area under the concentration-time curve (AUC) of berberine increased, while the AUC of coptisine, palmatine, and epiberberine decreased in the rabbits that received RCAE plus CNC. Meanwhile, the AUC of berberine, coptisine, palmatine, and epiberberine decreased in the group given RCAE plus AC. The difference of main pharmacokinetics parameters among the four groups was significant (P < 0.05). This study showed that CNC improved the bioavailability of berberine in comparison to AC and prolonged its release in comparison to RCAE alone. However, it decreased the bioavailability of coptisine, palmatine, and epiberberine. In comparison, AC uniformly declined the bioavailability of berberine, coptisine, palmatine, and epiberberine. PMID:27313645

Optimization of cellulose nanocrystal length and surface charge density through phosphoric acid hydrolysis

NASA Astrophysics Data System (ADS)

Vanderfleet, Oriana M.; Osorio, Daniel A.; Cranston, Emily D.

2017-12-01

Cellulose nanocrystals (CNCs) are emerging nanomaterials with a large range of potential applications. CNCs are typically produced through acid hydrolysis with sulfuric acid; however, phosphoric acid has the advantage of generating CNCs with higher thermal stability. This paper presents a design of experiments approach to optimize the hydrolysis of CNCs from cotton with phosphoric acid. Hydrolysis time, temperature and acid concentration were varied across nine experiments and a linear least-squares regression analysis was applied to understand the effects of these parameters on CNC properties. In all but one case, rod-shaped nanoparticles with a high degree of crystallinity and thermal stability were produced. A statistical model was generated to predict CNC length, and trends in phosphate content and zeta potential were elucidated. The CNC length could be tuned over a relatively large range (238-475 nm) and the polydispersity could be narrowed most effectively by increasing the hydrolysis temperature and acid concentration. The CNC phosphate content was most affected by hydrolysis temperature and time; however, the charge density and colloidal stability were considered low compared with sulfuric acid hydrolysed CNCs. This study provides insight into weak acid hydrolysis and proposes `design rules' for CNCs with improved size uniformity and charge density. This article is part of a discussion meeting issue `New horizons for cellulose nanotechnology'.

Well-dispersed cellulose nanocrystals in hydrophobic polymers by in situ polymerization for synthesizing highly reinforced bio-nanocomposites.

PubMed

Geng, Shiyu; Wei, Jiayuan; Aitomäki, Yvonne; Noël, Maxime; Oksman, Kristiina

2018-04-20

In nanocomposites, dispersing hydrophilic nanomaterials in a hydrophobic matrix using simple and environmentally friendly methods remains challenging. Herein, we report a method based on in situ polymerization to synthesize nanocomposites of well-dispersed cellulose nanocrystals (CNCs) and poly(vinyl acetate) (PVAc). We have also shown that by blending this PVAc/CNC nanocomposite with poly(lactic acid) (PLA), a good dispersion of the CNCs can be reached in PLA. The outstanding dispersion of CNCs in both PVAc and PLA/PVAc matrices was shown by different microscopy techniques and was further supported by the mechanical and rheological properties of the composites. The in situ PVAc/CNC nanocomposites exhibit enhanced mechanical properties compared to the materials produced by mechanical mixing, and a theoretical model based on the interphase effect and dispersion that reflects this behavior was developed. Comparison of the rheological and thermal behaviors of the mixed and in situ PVAc/CNC also confirmed the great improvement in the dispersion of nanocellulose in the latter. Furthermore, a synergistic effect was observed with only 0.1 wt% CNCs when the in situ PVAc/CNC was blended with PLA, as demonstrated by significant increases in elastic modulus, yield strength, elongation to break and glass transition temperature compared to the PLA/PVAc only material.

Small Maf proteins (MafF, MafG, MafK): History, structure and function.

PubMed

Katsuoka, Fumiki; Yamamoto, Masayuki

2016-07-25

The small Maf proteins (sMafs) are basic region leucine zipper (bZIP)-type transcription factors. The basic region of the Maf family is unique among the bZIP factors, and it contributes to the distinct DNA-binding mode of this class of proteins. MafF, MafG and MafK are the three vertebrate sMafs, and no functional differences have been observed among them in terms of their bZIP structures. sMafs form homodimers by themselves, and they form heterodimers with cap 'n' collar (CNC) proteins (p45 NF-E2, Nrf1, Nrf2, and Nrf3) and also with Bach proteins (Bach1 and Bach2). Because CNC and Bach proteins cannot bind to DNA as monomers, sMafs are indispensable partners that are required by CNC and Bach proteins to exert their functions. sMafs lack the transcriptional activation domain; hence, their homodimers act as transcriptional repressors. In contrast, sMafs participate in transcriptional activation or repression depending on their heterodimeric partner molecules and context. Mouse genetic analyses have revealed that various biological pathways are under the regulation of CNC-sMaf heterodimers. In this review, we summarize the history and current progress of sMaf studies in relation to their partners. Copyright © 2016 Elsevier B.V. All rights reserved.

OpenMM 4: A Reusable, Extensible, Hardware Independent Library for High Performance Molecular Simulation.

PubMed

Eastman, Peter; Friedrichs, Mark S; Chodera, John D; Radmer, Randall J; Bruns, Christopher M; Ku, Joy P; Beauchamp, Kyle A; Lane, Thomas J; Wang, Lee-Ping; Shukla, Diwakar; Tye, Tony; Houston, Mike; Stich, Timo; Klein, Christoph; Shirts, Michael R; Pande, Vijay S

2013-01-08

OpenMM is a software toolkit for performing molecular simulations on a range of high performance computing architectures. It is based on a layered architecture: the lower layers function as a reusable library that can be invoked by any application, while the upper layers form a complete environment for running molecular simulations. The library API hides all hardware-specific dependencies and optimizations from the users and developers of simulation programs: they can be run without modification on any hardware on which the API has been implemented. The current implementations of OpenMM include support for graphics processing units using the OpenCL and CUDA frameworks. In addition, OpenMM was designed to be extensible, so new hardware architectures can be accommodated and new functionality (e.g., energy terms and integrators) can be easily added.

OpenMM 4: A Reusable, Extensible, Hardware Independent Library for High Performance Molecular Simulation

PubMed Central

Eastman, Peter; Friedrichs, Mark S.; Chodera, John D.; Radmer, Randall J.; Bruns, Christopher M.; Ku, Joy P.; Beauchamp, Kyle A.; Lane, Thomas J.; Wang, Lee-Ping; Shukla, Diwakar; Tye, Tony; Houston, Mike; Stich, Timo; Klein, Christoph; Shirts, Michael R.; Pande, Vijay S.

2012-01-01

OpenMM is a software toolkit for performing molecular simulations on a range of high performance computing architectures. It is based on a layered architecture: the lower layers function as a reusable library that can be invoked by any application, while the upper layers form a complete environment for running molecular simulations. The library API hides all hardware-specific dependencies and optimizations from the users and developers of simulation programs: they can be run without modification on any hardware on which the API has been implemented. The current implementations of OpenMM include support for graphics processing units using the OpenCL and CUDA frameworks. In addition, OpenMM was designed to be extensible, so new hardware architectures can be accommodated and new functionality (e.g., energy terms and integrators) can be easily added. PMID:23316124

Architecture for Survivable System Processing (ASSP)

NASA Astrophysics Data System (ADS)

Wood, Richard J.

1991-11-01

The Architecture for Survivable System Processing (ASSP) Program is a multi-phase effort to implement Department of Defense (DOD) and commercially developed high-tech hardware, software, and architectures for reliable space avionics and ground based systems. System configuration options provide processing capabilities to address Time Dependent Processing (TDP), Object Dependent Processing (ODP), and Mission Dependent Processing (MDP) requirements through Open System Architecture (OSA) alternatives that allow for the enhancement, incorporation, and capitalization of a broad range of development assets. High technology developments in hardware, software, and networking models, address technology challenges of long processor life times, fault tolerance, reliability, throughput, memories, radiation hardening, size, weight, power (SWAP) and security. Hardware and software design, development, and implementation focus on the interconnectivity/interoperability of an open system architecture and is being developed to apply new technology into practical OSA components. To insure for widely acceptable architecture capable of interfacing with various commercial and military components, this program provides for regular interactions with standardization working groups (e.g.) the International Standards Organization (ISO), American National Standards Institute (ANSI), Society of Automotive Engineers (SAE), and Institute of Electrical and Electronic Engineers (IEEE). Selection of a viable open architecture is based on the widely accepted standards that implement the ISO/OSI Reference Model.

Architecture for Survivable System Processing (ASSP)

NASA Technical Reports Server (NTRS)

Wood, Richard J.

1991-01-01

The Architecture for Survivable System Processing (ASSP) Program is a multi-phase effort to implement Department of Defense (DOD) and commercially developed high-tech hardware, software, and architectures for reliable space avionics and ground based systems. System configuration options provide processing capabilities to address Time Dependent Processing (TDP), Object Dependent Processing (ODP), and Mission Dependent Processing (MDP) requirements through Open System Architecture (OSA) alternatives that allow for the enhancement, incorporation, and capitalization of a broad range of development assets. High technology developments in hardware, software, and networking models, address technology challenges of long processor life times, fault tolerance, reliability, throughput, memories, radiation hardening, size, weight, power (SWAP) and security. Hardware and software design, development, and implementation focus on the interconnectivity/interoperability of an open system architecture and is being developed to apply new technology into practical OSA components. To insure for widely acceptable architecture capable of interfacing with various commercial and military components, this program provides for regular interactions with standardization working groups (e.g.) the International Standards Organization (ISO), American National Standards Institute (ANSI), Society of Automotive Engineers (SAE), and Institute of Electrical and Electronic Engineers (IEEE). Selection of a viable open architecture is based on the widely accepted standards that implement the ISO/OSI Reference Model.

Implementing the space shuttle data processing system with the space generic open avionics architecture

NASA Technical Reports Server (NTRS)

Wray, Richard B.; Stovall, John R.

1993-01-01

This paper presents an overview of the application of the Space Generic Open Avionics Architecture (SGOAA) to the Space Shuttle Data Processing System (DPS) architecture design. This application has been performed to validate the SGOAA, and its potential use in flight critical systems. The paper summarizes key elements of the Space Shuttle avionics architecture, data processing system requirements and software architecture as currently implemented. It then summarizes the SGOAA architecture and describes a tailoring of the SGOAA to the Space Shuttle. The SGOAA consists of a generic system architecture for the entities in spacecraft avionics, a generic processing external and internal hardware architecture, a six class model of interfaces and functional subsystem architectures for data services and operations control capabilities. It has been proposed as an avionics architecture standard with the National Aeronautics and Space Administration (NASA), through its Strategic Avionics Technology Working Group, and is being considered by the Society of Aeronautic Engineers (SAE) as an SAE Avionics Standard. This architecture was developed for the Flight Data Systems Division of JSC by the Lockheed Engineering and Sciences Company, Houston, Texas.

An Open Avionics and Software Architecture to Support Future NASA Exploration Missions

NASA Technical Reports Server (NTRS)

Schlesinger, Adam

2017-01-01

The presentation describes an avionics and software architecture that has been developed through NASAs Advanced Exploration Systems (AES) division. The architecture is open-source, highly reliable with fault tolerance, and utilizes standard capabilities and interfaces, which are scalable and customizable to support future exploration missions. Specific focus areas of discussion will include command and data handling, software, human interfaces, communication and wireless systems, and systems engineering and integration.

The OPEN Migration Platform Architecture

NASA Astrophysics Data System (ADS)

Martin, Miquel

This chapter establishes a common understanding of the meaning of migration, and introduces the OPEN functionalities, which enable application migration. We start by discussing the various definitions of migration, before focusing on the OPEN take on the concept. The chapter then covers our proposed architecture , as well as the functionality required, both from the server and the client side (i.e. the applications) in order to enable application migration.

Open Space, Open Education, and Pupil Performance.

ERIC Educational Resources Information Center

Lukasevich, Ann; Gray, Roland F.

1978-01-01

Explores the relationship between instructional style (open and non-open programs), architectural style (open and non-open facilities) and selected cognitive and affective outcomes of third grade pupils. (CM)

Blue guardian: an open architecture for rapid ISR demonstration

NASA Astrophysics Data System (ADS)

Barrett, Donald A.; Borntrager, Luke A.; Green, David M.

2016-05-01

Throughout the Department of Defense (DoD), acquisition, platform integration, and life cycle costs for weapons systems have continued to rise. Although Open Architecture (OA) interface standards are one of the primary methods being used to reduce these costs, the Air Force Rapid Capabilities Office (AFRCO) has extended the OA concept and chartered the Open Mission System (OMS) initiative with industry to develop and demonstrate a consensus-based, non-proprietary, OA standard for integrating subsystems and services into airborne platforms. The new OMS standard provides the capability to decouple vendor-specific sensors, payloads, and service implementations from platform-specific architectures and is still in the early stages of maturation and demonstration. The Air Force Research Laboratory (AFRL) - Sensors Directorate has developed the Blue Guardian program to demonstrate advanced sensing technology utilizing open architectures in operationally relevant environments. Over the past year, Blue Guardian has developed a platform architecture using the Air Force's OMS reference architecture and conducted a ground and flight test program of multiple payload combinations. Systems tested included a vendor-unique variety of Full Motion Video (FMV) systems, a Wide Area Motion Imagery (WAMI) system, a multi-mode radar system, processing and database functions, multiple decompression algorithms, multiple communications systems, and a suite of software tools. Initial results of the Blue Guardian program show the promise of OA to DoD acquisitions, especially for Intelligence, Surveillance and Reconnaissance (ISR) payload applications. Specifically, the OMS reference architecture was extremely useful in reducing the cost and time required for integrating new systems.

Data Architecture in an Open Systems Environment.

ERIC Educational Resources Information Center

Bernbom, Gerald; Cromwell, Dennis

1993-01-01

The conceptual basis for structured data architecture, and its integration with open systems technology at Indiana University, are described. Key strategic goals guiding these efforts are discussed: commitment to improved data access; migration to relational database technology, and deployment of a high-speed, multiprotocol network; and…

Analysis OpenMP performance of AMD and Intel architecture for breaking waves simulation using MPS

NASA Astrophysics Data System (ADS)

Alamsyah, M. N. A.; Utomo, A.; Gunawan, P. H.

2018-03-01

Simulation of breaking waves by using Navier-Stokes equation via moving particle semi-implicit method (MPS) over close domain is given. The results show the parallel computing on multicore architecture using OpenMP platform can reduce the computational time almost half of the serial time. Here, the comparison using two computer architectures (AMD and Intel) are performed. The results using Intel architecture is shown better than AMD architecture in CPU time. However, in efficiency, the computer with AMD architecture gives slightly higher than the Intel. For the simulation by 1512 number of particles, the CPU time using Intel and AMD are 12662.47 and 28282.30 respectively. Moreover, the efficiency using similar number of particles, AMD obtains 50.09 % and Intel up to 49.42 %.

CNC Machining Of The Complex Copper Electrodes

NASA Astrophysics Data System (ADS)

Popan, Ioan Alexandru; Balc, Nicolae; Popan, Alina

2015-07-01

This paper presents the machining process of the complex copper electrodes. Machining of the complex shapes in copper is difficult because this material is soft and sticky. This research presents the main steps for processing those copper electrodes at a high dimensional accuracy and a good surface quality. Special tooling solutions are required for this machining process and optimal process parameters have been found for the accurate CNC equipment, using smart CAD/CAM software.

Neural crest development and craniofacial morphogenesis is coordinated by nitric oxide and histone acetylation

PubMed Central

Kong, Yawei; Grimaldi, Michael; Curtin, Eugene; Dougherty, Max; Kaufman, Charles; White, Richard M.; Zon, Leonard I.; Liao, Eric C.

2015-01-01

Cranial neural crest (CNC) cells are patterned and coalesce to facial prominences that undergo convergence and extension to generate the craniofacial form. We applied a chemical genetics approach to identify pathways that regulate craniofacial development during embryogenesis. Treatment with the nitric oxide synthase inhibitor TRIM abrogated first pharyngeal arch structures and induced ectopic ceratobranchial formation. TRIM promoted a progenitor CNC fate and inhibited chondrogenic differentiation, which were mediated through impaired nitric oxide (NO) production without appreciable effect on global protein S-nitrosylation. Instead, TRIM perturbed hox gene patterning and caused histone hypoacetylation. Rescue of TRIM phenotype was achieved with over-expression of histone acetyltransferase kat6a, inhibition of histone deacetylase, and complimentary NO. These studies demonstrate that NO signaling and histone acetylation are coordinated mechanisms that regulate CNC patterning, differentiation and convergence during craniofacial morphogenesis. PMID:24684905

Water Vapor Uptake of Ultrathin Films of Biologically Derived Nanocrystals: Quantitative Assessment with Quartz Crystal Microbalance and Spectroscopic Ellipsometry.

PubMed

Niinivaara, Elina; Faustini, Marco; Tammelin, Tekla; Kontturi, Eero

2015-11-10

Despite the relevance of water interactions, explicit analysis of vapor adsorption on biologically derived surfaces is often difficult. Here, a system was introduced to study the vapor uptake on a native polysaccharide surface; namely, cellulose nanocrystal (CNC) ultrathin films were examined with a quartz crystal microbalance with dissipation monitoring (QCM-D) and spectroscopic ellipsometry (SE). A significant mass uptake of water vapor by the CNC films was detected using the QCM-D upon increasing relative humidity. In addition, thickness changes proportional to changes in relative humidity were detected using SE. Quantitative analysis of the results attained indicated that in preference to being soaked by water at the point of hydration each individual CNC in the film became enveloped by a 1 nm thick layer of adsorbed water vapor, resulting in the detected thickness response.

Research on carrying capacity of hydrostatic slideway on heavy-duty gantry CNC machine

NASA Astrophysics Data System (ADS)

Cui, Chao; Guo, Tieneng; Wang, Yijie; Dai, Qin

2017-05-01

Hydrostatic slideway is a key part in the heavy-duty gantry CNC machine, which supports the total weight of the gantry and moves smoothly along the table. Therefore, the oil film between sliding rails plays an important role on the carrying capacity and precision of machine. In this paper, the oil film in no friction is simulated with three-dimensional CFD. The carrying capacity of heavy hydrostatic slideway, pressure and velocity characteristic of the flow field are analyzed. The simulation result is verified through comparing with the experimental data obtained from the heavy-duty gantry machine. For the requirement of engineering, the oil film carrying capacity is analyzed with simplified theoretical method. The precision of the simplified method is evaluated and the effectiveness is verified with the experimental data. The simplified calculation method is provided for designing oil pad on heavy-duty gantry CNC machine hydrostatic slideway.

VORTEX: Versatile and open subsea robot for technical experiment: Prototyping software architecture for the next AUV and ROV generation

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

Rigaud, V.; Le Rest, E.; Marce, L.

1994-12-31

This paper describes a new experimental vehicle named V.O.R.T.E.X. (Versatile and Open subsea Robot for Technical EXperiment) built by the Subsea Robotics Laboratory at the French institute for Sea exploitation (Ifremer). The aim of this project is to work out the metamorphosis of a classical ROV architecture into an AUV architecture in particular for the control and programming architecture design. This vehicle is also designed to emulate the new IFREMER ROV6000 and the future Abyssal Survey Vehicle AUV, from a functional point of view.

Joint Common Architecture Demonstration (JCA Demo) Final Report

DTIC Science & Technology

2016-07-28

approach for implementing open systems [16], formerly known as the Modular Open Systems Approach (MOSA). OSA is a business and technical strategy to... TECHNICAL REPORT RDMR-AD-16-01 JOINT COMMON ARCHITECTURE DEMONSTRATION (JCA DEMO) FINAL REPORT Scott A. Wigginton... Modular Avionics .......................................................................... 5 E. Model-Based Engineering

Finding Services for an Open Architecture: A Review of Existing Applications and Programs in PEO C4I

DTIC Science & Technology

2011-01-01

2004) Two key SOA success factors listed were as follows: 1. Shared Services Strategy: Existence of a strategy to identify overlapping business and...model Architectural pattern 22 Finding Services for an Open Architecture or eliminating redundancies and overlaps through use of shared services 2...Funding Model: Existence of an IT funding model aligned with and supportive of a shared services strategy. (Sun Micro- systems, 2004) Become Data

Architecture of the Yeast RNA Polymerase II Open Complex and Regulation of Activity by TFIIF

PubMed Central

Fishburn, James

2012-01-01

To investigate the function and architecture of the open complex state of RNA polymerase II (Pol II), Saccharomyces cerevisiae minimal open complexes were assembled by using a series of heteroduplex HIS4 promoters, TATA binding protein (TBP), TFIIB, and Pol II. The yeast system demonstrates great flexibility in the position of active open complexes, spanning 30 to 80 bp downstream from TATA, consistent with the transcription start site scanning behavior of yeast Pol II. TFIIF unexpectedly modulates the activity of the open complexes, either repressing or stimulating initiation. The response to TFIIF was dependent on the sequence of the template strand within the single-stranded bubble. Mutations in the TFIIB reader and linker region, which were inactive on duplex DNA, were suppressed by the heteroduplex templates, showing that a major function of the TFIIB reader and linker is in the initiation or stabilization of single-stranded DNA. Probing of the architecture of the minimal open complexes with TFIIB-FeBABE [TFIIB–p-bromoacetamidobenzyl–EDTA-iron(III)] derivatives showed that the TFIIB core domain is surprisingly positioned away from Pol II, and the addition of TFIIF repositions the TFIIB core domain to the Pol II wall domain. Together, our results show an unexpected architecture of minimal open complexes and the regulation of activity by TFIIF and the TFIIB core domain. PMID:22025674

The Dependence of the Circumnuclear Coma Structure on the Properties of the Nucleus

NASA Astrophysics Data System (ADS)

Crifo, J. F.; Rodionov, A. V.

1997-06-01

A new step of development of the 3-D circumnuclear coma (“CNC”) model described in Crifoet al.(1995) is presented: now the gas and dust production are computed from an explicit dusty-ice sublimation model and a realistic dust mass spectrum is used. For the first time, (1) a clear distinction is made betweennucleus active area fraction gandactive surface icy area fraction f; (2) the dependence of the dusty ice sublimation rate onfand that offon the heliocentric distancerhdue to the evolution of the dust cover are explicitly taken into account; (3) the 3-D structure of the CNC is described thoroughly instead of only in one symmetry plane; (4) the 3-D CNC model is quantitatively fitted to observational data; (5) a detailed comparison is made between the CNC structures resulting from two alternative assumptions concerning the nucleus. The first assumed nucleus is a homogeneous sphere of dusty ice (g= 1). We show that, in this case: (1) The maximum ejectable mass of spherical dust grains has a ∝f(rh) cosz/r2hdependence upon solar zenith anglezand uponrh. (2) The terminal ejected dust velocities have an approximate ∝coszdependence onzand a strong ∝f(rh)/rhdependence onrh. Fitting-for definiteness-the model to the light curve of the weak Comet P/Wirtanen (P/W), target of the future Rosetta mission, we find, assuming an upper limit nucleus radius of 1.4 km, that: (1)fdecreases from about 14% at perihelion to possibly 0.025% atrh= 3 AU; (2) forrh≤ 2.5 AU all or most of the sunward circumnuclear CNC is in fluid regime; (3) for 2.5 ≤rh≤ 3 AU, most of the sunward CNC is in the so-called “transition regime”; (4) due to their dependence uponf, the dust velocities are in absolute value much smaller than expected from the usually accepted algorithms (which assumef≡ 1) and decrease strongly with increasingrh. The physical significance of these results is discussed. The second assumed nucleus fitted to P/W is an inhomogeneous sphere of dusty ice, most of the gas and dust production being due to four identical active areas separated by a background area, and covering a fractiong= 0.43 of the surface. It is found that, up to at least 2 AU, the structure of the CNC is, in such a case complex. (1) Owing to the difference in solar zenith angle, identical active areas produce differing CNC gas and dust distributions: therefore, in an inhomogeneous rotating nucleus, an active region is not characterized by a fixed corotating CNC pattern. (2) As with more productive comets, the interaction between gas issuing from different active regions leads to the formation of three-dimensional quasi stationary shock structures. (3) In particular, the weaker active areas cannot expand freely in the sunward hemisphere, but are surrounded by a low-altitude concave sheath of shocked gas and deflected dust. (4) Near to the shock surfaces, the dust density distribution is characterized, as in more productive comets, by density patterns that mimic dust jets. (5) Over the background areas, and close to the surface, the gas flows transverse to the vertical, and exhibits steepincreasesin density outwards. (6) The results reveal a fast smoothing-out of the CNC near-surface patterns with increasing distance to the surface. The implications of the present results for (1) the general physical characterization of comet nuclei on the basis of their coma-averaged properties, and (2) the assessment of the environmental parameters of future cometary close encounter missions are discussed. In particular, we show that simple, unidimensional heuristic models based on observations of a comet from the Earth are unable to provide relevant predictions concerning the physical conditions near to its nucleus. This conclusion is further enforced by the companion paper-Crifo and Rodionov (1996)-in which anasphericalhomogeneous nucleus is assumed.

Final Report: CNC Micromachines LDRD No.10793

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

JOKIEL JR., BERNHARD; BENAVIDES, GILBERT L.; BIEG, LOTHAR F.

2003-04-01

The three-year LDRD ''CNC Micromachines'' was successfully completed at the end of FY02. The project had four major breakthroughs in spatial motion control in MEMS: (1) A unified method for designing scalable planar and spatial on-chip motion control systems was developed. The method relies on the use of parallel kinematic mechanisms (PKMs) that when properly designed provide different types of motion on-chip without the need for post-fabrication assembly, (2) A new type of actuator was developed--the linear stepping track drive (LSTD) that provides open loop linear position control that is scalable in displacement, output force and step size. Several versionsmore » of this actuator were designed, fabricated and successfully tested. (3) Different versions of XYZ translation only and PTT motion stages were designed, successfully fabricated and successfully tested demonstrating absolutely that on-chip spatial motion control systems are not only possible, but are a reality. (4) Control algorithms, software and infrastructure based on MATLAB were created and successfully implemented to drive the XYZ and PTT motion platforms in a controlled manner. The control software is capable of reading an M/G code machine tool language file, decode the instructions and correctly calculate and apply position and velocity trajectories to the motion devices linear drive inputs to position the device platform along the trajectory as specified by the input file. A full and detailed account of design methodology, theory and experimental results (failures and successes) is provided.« less

From GCode to STL: Reconstruct Models from 3D Printing as a Service

NASA Astrophysics Data System (ADS)

Baumann, Felix W.; Schuermann, Martin; Odefey, Ulrich; Pfeil, Markus

2017-12-01

The authors present a method to reverse engineer 3D printer specific machine instructions (GCode) to a point cloud representation and then a STL (Stereolithography) file format. GCode is a machine code that is used for 3D printing among other applications, such as CNC routers. Such code files contain instructions for the 3D printer to move and control its actuator, in case of Fused Deposition Modeling (FDM), the printhead that extrudes semi-molten plastics. The reverse engineering method presented here is based on the digital simulation of the extrusion process of FDM type 3D printing. The reconstructed models and pointclouds do not accommodate for hollow structures, such as holes or cavities. The implementation is performed in Python and relies on open source software and libraries, such as Matplotlib and OpenCV. The reconstruction is performed on the model’s extrusion boundary and considers mechanical imprecision. The complete reconstruction mechanism is available as a RESTful (Representational State Transfer) Web service.

Exploiting the CNC side chain in heterocyclic rearrangements: synthesis of 4(5)-acylamino-imidazoles.

PubMed

Piccionello, Antonio Palumbo; Buscemi, Silvestre; Vivona, Nicolò; Pace, Andrea

2010-08-06

A new variation on the Boulton-Katritzky reaction is reported, namely, involving use of a CNC side chain. A novel Montmorillonite-K10 catalyzed nonreductive transamination of a 3-benzoyl-1,2,4-oxadiazole afforded a 3-(alpha-aminobenzyl)-1,2,4-oxadiazole, which was condensed with benzaldehydes to afford the corresponding imines. In the presence of strong base, these imines underwent Boulton-Katritzky-type rearrangement to afford novel 4(5)-acylaminoimidazoles.

High-temperature Superconductivity in Diamond Films - from Fundamentals to Device Applications

DTIC Science & Technology

2014-12-20

film is later removed by acid boiling in nitric acid. The laser cutting process is completely based on CNC machine language. Therefore arbitrary...designed Hall bar shapes and converted them in CNC language. Fig 6. Laser Cutter (Alpha) to create holes in the diamond plates (Oxford Lasers). [5...diamond density is not uniform throughout the plate as it appears lighter on the right side. This could be caused by the plasma being of different

Discomfort analysis in computerized numeric control machine operations.

PubMed

Muthukumar, Krishnamoorthy; Sankaranarayanasamy, Krishnasamy; Ganguli, Anindya Kumar

2012-06-01

The introduction of computerized numeric control (CNC) technology in manufacturing industries has revolutionized the production process, but there are some health and safety problems associated with these machines. The present study aimed to investigate the extent of postural discomfort in CNC machine operators, and the relationship of this discomfort to the display and control panel height, with a view to validate the anthropometric recommendation for the location of the display and control panel in CNC machines. The postural discomforts associated with CNC machines were studied in 122 male operators using Corlett and Bishop's body part discomfort mapping, subject information, and discomfort level at various time intervals from starting to end of a shift. This information was collected using a questionnaire. Statistical analysis was carried out using ANOVA. Neck discomfort due to the positioning of the machine displays, and shoulder and arm discomfort due to the positioning of controls were identified as common health issues in the operators of these machines. The study revealed that 45.9% of machine operators reported discomfort in the lower back, 41.8% in the neck, 22.1% in the upper-back, 53.3% in the shoulder and arm, and 21.3% of the operators reported discomfort in the leg. Discomfort increased with the progress of the day and was highest at the end of a shift; subject age had no effect on patient tendency to experience discomfort levels.

Discomfort Analysis in Computerized Numeric Control Machine Operations

PubMed Central

Sankaranarayanasamy, Krishnasamy; Ganguli, Anindya Kumar

2012-01-01

Objectives The introduction of computerized numeric control (CNC) technology in manufacturing industries has revolutionized the production process, but there are some health and safety problems associated with these machines. The present study aimed to investigate the extent of postural discomfort in CNC machine operators, and the relationship of this discomfort to the display and control panel height, with a view to validate the anthropometric recommendation for the location of the display and control panel in CNC machines. Methods The postural discomforts associated with CNC machines were studied in 122 male operators using Corlett and Bishop's body part discomfort mapping, subject information, and discomfort level at various time intervals from starting to end of a shift. This information was collected using a questionnaire. Statistical analysis was carried out using ANOVA. Results Neck discomfort due to the positioning of the machine displays, and shoulder and arm discomfort due to the positioning of controls were identified as common health issues in the operators of these machines. The study revealed that 45.9% of machine operators reported discomfort in the lower back, 41.8% in the neck, 22.1% in the upper-back, 53.3% in the shoulder and arm, and 21.3% of the operators reported discomfort in the leg. Conclusion Discomfort increased with the progress of the day and was highest at the end of a shift; subject age had no effect on patient tendency to experience discomfort levels. PMID:22993720

FAF1, a Gene that Is Disrupted in Cleft Palate and Has Conserved Function in Zebrafish

PubMed Central

Ghassibe-Sabbagh, Michella; Desmyter, Laurence; Langenberg, Tobias; Claes, Filip; Boute, Odile; Bayet, Bénédicte; Pellerin, Philippe; Hermans, Karlien; Backx, Liesbeth; Mansilla, Maria Adela; Imoehl, Sandra; Nowak, Stefanie; Ludwig, Kerstin U.; Baluardo, Carlotta; Ferrian, Melissa; Mossey, Peter A.; Noethen, Markus; Dewerchin, Mieke; François, Geneviève; Revencu, Nicole; Vanwijck, Romain; Hecht, Jacqueline; Mangold, Elisabeth; Murray, Jeffrey; Rubini, Michele; Vermeesch, Joris R.; Poirel, Hélène A.; Carmeliet, Peter; Vikkula, Miikka

2011-01-01

Cranial neural crest (CNC) is a multipotent migratory cell population that gives rise to most of the craniofacial bones. An intricate network mediates CNC formation, epithelial-mesenchymal transition, migration along distinct paths, and differentiation. Errors in these processes lead to craniofacial abnormalities, including cleft lip and palate. Clefts are the most common congenital craniofacial defects. Patients have complications with feeding, speech, hearing, and dental and psychological development. Affected by both genetic predisposition and environmental factors, the complex etiology of clefts remains largely unknown. Here we show that Fas-associated factor-1 (FAF1) is disrupted and that its expression is decreased in a Pierre Robin family with an inherited translocation. Furthermore, the locus is strongly associated with cleft palate and shows an increased relative risk. Expression studies show that faf1 is highly expressed in zebrafish cartilages during embryogenesis. Knockdown of zebrafish faf1 leads to pharyngeal cartilage defects and jaw abnormality as a result of a failure of CNC to differentiate into and express cartilage-specific markers, such as sox9a and col2a1. Administration of faf1 mRNA rescues this phenotype. Our findings therefore identify FAF1 as a regulator of CNC differentiation and show that it predisposes humans to cleft palate and is necessary for lower jaw development in zebrafish. PMID:21295280

Kangaroo Mother Care: four years of experience in very low birth weight and preterm infants.

PubMed

Tuoni, C; Scaramuzzo, R T; Ghirri, P; Boldrini, A; Bartalena, L

2012-08-01

Kangaroo Mother Care (KMC) is a method of providing care for preterm infants through skin-to-skin contact with the mother and, preferably, exclusive breastfeeding. The growing interest in KMC at the Neonatology Unit of Pisa has provided the occasion for a retrospective analysis of the last four years, comparing the clinical effects of the kangaroo method vs. those obtained with conventional care (CNC) with respect to indicators of the general health of the infants (indices of growth, and duration of breastfeeding and hospitalization). A total of 213 infants, aged <37 gestational weeks and weighing ≤1500 g were enrolled for the study; these were divided into two groups for the purpose of comparison (91 in KMC vs. 71 in CNC). The indices of growth and the duration of the infants in hospital were not significantly different in the two groups. Nevertheless, it is worth noting how KMC is more efficacious in the very tiny VLBW infants, and that the means of the growth parameters in the KMC infants are greater than those referring to the CNC subjects, body temperatures taken at the beginning and end of a KMC session are higher, and that the mother-child relationship facilitates better sucking-feeding. While KMC is equivalent to CNC in terms of safety, thermal protection, morbidity and auxologic development, it appears to promote humanisation of infant care and mother-child bond more quickly.

Open mHealth Architecture: A Primer for Tomorrow's Orthopedic Surgeon and Introduction to Its Use in Lower Extremity Arthroplasty.

PubMed

Ramkumar, Prem N; Muschler, George F; Spindler, Kurt P; Harris, Joshua D; McCulloch, Patrick C; Mont, Michael A

2017-04-01

The recent private-public partnership to unlock and utilize all available health data has large-scale implications for public health and personalized medicine, especially within orthopedics. Today, consumer based technologies such as smartphones and "wearables" store tremendous amounts of personal health data (known as "mHealth") that, when processed and contextualized, have the potential to open new windows of insight for the orthopedic surgeon about their patients. In the present report, the landscape, role, and future technical considerations of mHealth and open architecture are defined with particular examples in lower extremity arthroplasty. A limitation of the current mHealth landscape is the fragmentation and lack of interconnectivity between the myriad of available apps. The importance behind the currently lacking open mHealth architecture is underscored by the offer of improved research, increased workflow efficiency, and value capture for the orthopedic surgeon. There exists an opportunity to leverage existing mobile health data for orthopaedic surgeons, particularly those specializing in lower extremity arthroplasty, by transforming patient small data into insightful big data through the implementation of "open" architecture that affords universal data standards and a global interconnected network. Copyright © 2016 Elsevier Inc. All rights reserved.

Space Generic Open Avionics Architecture (SGOAA) reference model technical guide

NASA Technical Reports Server (NTRS)

Wray, Richard B.; Stovall, John R.

1993-01-01

This report presents a full description of the Space Generic Open Avionics Architecture (SGOAA). The SGOAA consists of a generic system architecture for the entities in spacecraft avionics, a generic processing architecture, and a six class model of interfaces in a hardware/software system. The purpose of the SGOAA is to provide an umbrella set of requirements for applying the generic architecture interface model to the design of specific avionics hardware/software systems. The SGOAA defines a generic set of system interface points to facilitate identification of critical interfaces and establishes the requirements for applying appropriate low level detailed implementation standards to those interface points. The generic core avionics system and processing architecture models provided herein are robustly tailorable to specific system applications and provide a platform upon which the interface model is to be applied.

Open architecture of smart sensor suites

NASA Astrophysics Data System (ADS)

Müller, Wilmuth; Kuwertz, Achim; Grönwall, Christina; Petersson, Henrik; Dekker, Rob; Reinert, Frank; Ditzel, Maarten

2017-10-01

Experiences from recent conflicts show the strong need for smart sensor suites comprising different multi-spectral imaging sensors as core elements as well as additional non-imaging sensors. Smart sensor suites should be part of a smart sensor network - a network of sensors, databases, evaluation stations and user terminals. Its goal is to optimize the use of various information sources for military operations such as situation assessment, intelligence, surveillance, reconnaissance, target recognition and tracking. Such a smart sensor network will enable commanders to achieve higher levels of situational awareness. Within the study at hand, an open system architecture was developed in order to increase the efficiency of sensor suites. The open system architecture for smart sensor suites, based on a system-of-systems approach, enables combining different sensors in multiple physical configurations, such as distributed sensors, co-located sensors combined in a single package, tower-mounted sensors, sensors integrated in a mobile platform, and trigger sensors. The architecture was derived from a set of system requirements and relevant scenarios. Its mode of operation is adaptable to a series of scenarios with respect to relevant objects of interest, activities to be observed, available transmission bandwidth, etc. The presented open architecture is designed in accordance with the NATO Architecture Framework (NAF). The architecture allows smart sensor suites to be part of a surveillance network, linked e.g. to a sensor planning system and a C4ISR center, and to be used in combination with future RPAS (Remotely Piloted Aircraft Systems) for supporting a more flexible dynamic configuration of RPAS payloads.

Advanced biomaterials from renewable resources: An investigation on cellulose nanocrystal composites and carbon dioxide extraction of rendered materials

NASA Astrophysics Data System (ADS)

Orellana, Jose Luis

The annual global consumption of petroleum-based plastics is approximately 280 million tons and is impacting the sustainability of our planet and prosperity of future generations. One solution is the development of bio-based polymer materials with advanced properties for commercial applications. Therefore, the ultimate goal of this dissertation is to investigate the properties of new bio-based materials for broader applications. This dissertation includes two research areas: cellulose nanocomposites, and CO2 extractions of rendered fat. In the first half, cellulose nanocrystals (CNCs), which exhibit excellent mechanical and optical properties, were investigated for the reinforcement of a biodegradable polymer. The properties of these nanocomposites were studied to intellectually contribute to the understanding of the reinforcement mechanisms of CNC nanocomposites. In the second half, a more efficient and greener extraction of fat from rendered materials (RMs) was explored to broaden their potential applications, which include protein-based polymers and biofuels. Since CNCs are hydrophilic, surface modification with various surfactants was first accomplished in this research, increasing the dispersion stability in non-polar solvents by at least a month. Only 1 wt.% of surfactant with respect to CNCs was needed to afford a significant increase in the CNC stability, representing a much lower percentage than the values reported in the literature. Moreover, these CNCs showed the ability to selfassemble into local liquid crystal structures, a potential advantage for polymer reinforcement. CNCs were subsequently investigated as an additive for polylactic acid (PLA), which is the most widely used synthetic biopolymer in the market. CNC addition yielded a 61% increase in toughness at 1 wt.% CNC load. The tensile strength and modulus were not affected by the CNC addition, addressing one of the most frequent issues in the toughening of polymers. In addition, polarized microscopy revealed selfassembly formation of the enhanced composites indicating that the reinforcement was influenced by the CNC nanoscale structure on the matrix. These structures were found to be distributed in different directions along the extrusion line, suggesting that an angled CNC orientation favored a higher toughness as observed in natural cellulose fibers. PLA was also modified by grafting polyacrylic acid (PAA), which provided a stiffer and more hydrophilic surface for the addition of unmodified CNCs. In this case, the toughness of the PLA copolymer decreased with CNC concentration, while the tensile modulus increased. This effect was attributed to an increase of polymer crystallinity upon addition of CNCs, probably due to an enhanced compatibility provided by the PAA chains. For the purpose of obtaining a more efficient separation of proteins and fats from RMs, liquid and supercritical CO2 (LCO2 and SCCO2) were explored as solvents for the extraction, demonstrating the ability to extract up to 97% of the fat in the RMs. Higher fat solubilities in LCO2 were obtained compared to SCCO2, a result attributed to a retrograde phenomenon. These results are advantageous for the separation of rendered fats at relatively low temperatures and pressures, obtaining higher yields than screw pressing currently used in the industry. However, this extraction requires high amounts of CO2 due to low fat solubilities. This issue was addressed using CO2-assisted mechanical extraction, resulting in yields up to 81%, representing a 98% increase compared to conventional extraction, and significantly reducing the amount of CO2 for the extraction.

Higher Crash and Near-Crash Rates in Teenaged Drivers With Lower Cortisol Response

PubMed Central

Ouimet, Marie Claude; Brown, Thomas G.; Guo, Feng; Klauer, Sheila G.; Simons-Morton, Bruce G.; Fang, Youjia; Lee, Suzanne E.; Gianoulakis, Christina; Dingus, Thomas A.

2014-01-01

IMPORTANCE Road traffic crashes are one of the leading causes of injury and death among teenagers worldwide. Better understanding of the individual pathways to driving risk may lead to better-targeted intervention in this vulnerable group. OBJECTIVE To examine the relationship between cortisol, a neurobiological marker of stress regulation linked to risky behavior, and driving risk. DESIGN, SETTING, AND PARTICIPANTS The Naturalistic Teenage Driving Study was designed to continuously monitor the driving behavior of teenagers by instrumenting vehicles with kinematic sensors, cameras, and a global positioning system. During 2006–2008, a community sample of 42 newly licensed 16-year-old volunteer participants in the United States was recruited and driving behavior monitored. It was hypothesized in teenagers that higher cortisol response to stress is associated with (1) lower crash and near-crash (CNC) rates during their first 18 months of licensure and (2) faster reduction in CNC rates over time. MAIN OUTCOMES AND MEASURES Participants’ cortisol response during a stress-inducing task was assessed at baseline, followed by measurement of their involvement in CNCs and driving exposure during their first 18 months of licensure. Mixed-effect Poisson longitudinal regression models were used to examine the association between baseline cortisol response and CNC rates during the follow-up period. RESULTS Participants with a higher baseline cortisol response had lower CNC rates during the follow-up period (exponential of the regression coefficient, 0.93; 95%CI, 0.88–0.98) and faster decrease in CNC rates over time (exponential of the regression coefficient, 0.98; 95%, CI, 0.96–0.99). CONCLUSIONS AND RELEVANCE Cortisol is a neurobiological marker associated with teenaged-driving risk. As in other problem-behavior fields, identification of an objective marker of teenaged-driving risk promises the development of more personalized intervention approaches. PMID:24710522

The effect of instantaneous input dynamic range setting on the speech perception of children with the nucleus 24 implant.

PubMed

Davidson, Lisa S; Skinner, Margaret W; Holstad, Beth A; Fears, Beverly T; Richter, Marie K; Matusofsky, Margaret; Brenner, Christine; Holden, Timothy; Birath, Amy; Kettel, Jerrica L; Scollie, Susan

2009-06-01

The purpose of this study was to examine the effects of a wider instantaneous input dynamic range (IIDR) setting on speech perception and comfort in quiet and noise for children wearing the Nucleus 24 implant system and the Freedom speech processor. In addition, children's ability to understand soft and conversational level speech in relation to aided sound-field thresholds was examined. Thirty children (age, 7 to 17 years) with the Nucleus 24 cochlear implant system and the Freedom speech processor with two different IIDR settings (30 versus 40 dB) were tested on the Consonant Nucleus Consonant (CNC) word test at 50 and 60 dB SPL, the Bamford-Kowal-Bench Speech in Noise Test, and a loudness rating task for four-talker speech noise. Aided thresholds for frequency-modulated tones, narrowband noise, and recorded Ling sounds were obtained with the two IIDRs and examined in relation to CNC scores at 50 dB SPL. Speech Intelligibility Indices were calculated using the long-term average speech spectrum of the CNC words at 50 dB SPL measured at each test site and aided thresholds. Group mean CNC scores at 50 dB SPL with the 40 IIDR were significantly higher (p < 0.001) than with the 30 IIDR. Group mean CNC scores at 60 dB SPL, loudness ratings, and the signal to noise ratios-50 for Bamford-Kowal-Bench Speech in Noise Test were not significantly different for the two IIDRs. Significantly improved aided thresholds at 250 to 6000 Hz as well as higher Speech Intelligibility Indices afforded improved audibility for speech presented at soft levels (50 dB SPL). These results indicate that an increased IIDR provides improved word recognition for soft levels of speech without compromising comfort of higher levels of speech sounds or sentence recognition in noise.

GiPSi:a framework for open source/open architecture software development for organ-level surgical simulation.

PubMed

Cavuşoğlu, M Cenk; Göktekin, Tolga G; Tendick, Frank

2006-04-01

This paper presents the architectural details of an evolving open source/open architecture software framework for developing organ-level surgical simulations. Our goal is to facilitate shared development of reusable models, to accommodate heterogeneous models of computation, and to provide a framework for interfacing multiple heterogeneous models. The framework provides an application programming interface for interfacing dynamic models defined over spatial domains. It is specifically designed to be independent of the specifics of the modeling methods used, and therefore facilitates seamless integration of heterogeneous models and processes. Furthermore, each model has separate geometries for visualization, simulation, and interfacing, allowing the model developer to choose the most natural geometric representation for each case. Input/output interfaces for visualization and haptics for real-time interactive applications have also been provided.

More steps towards process automation for optical fabrication

NASA Astrophysics Data System (ADS)

Walker, David; Yu, Guoyu; Beaucamp, Anthony; Bibby, Matt; Li, Hongyu; McCluskey, Lee; Petrovic, Sanja; Reynolds, Christina

2017-06-01

In the context of Industrie 4.0, we have previously described the roles of robots in optical processing, and their complementarity with classical CNC machines, providing both processing and automation functions. After having demonstrated robotic moving of parts between a CNC polisher and metrology station, and auto-fringe-acquisition, we have moved on to automate the wash-down operation. This is part of a wider strategy we describe in this paper, leading towards automating the decision-making operations required before and throughout an optical manufacturing cycle.

Spatially Targeted Activation of a Shape Memory, Polymer-Based, Reconfigurable Skin System

DTIC Science & Technology

2014-02-01

bone samples described in ASTM Standard D638 using a CNC router. Compression test samples were cured in an aluminum cylinder mold treated with mold...release with Teflon end plugs and cut to length with a small lathe . 2.2 Tensile/Compressive Tests Tensile tests were conducted on a MTS QTest/1L...fixture with a CNC mill and a decal applied to the front surface for tracking by the DIC system. Figure 10: Shear Test Sample with DIC Decal 10

State-of-the-Art in Improved Parts Programming for Numerically Controlled Machines

DTIC Science & Technology

1976-10-01

than expected let sizes for IIC. Cincinnati lilbcron, Inc., has built a $1.25 million Computer Ilumerical Control ( CNC ) 1,4nufacturing Center to "rw’ t...point-to- point user. Lathe and other turning operations are essentially two-axis opera- tions, and there has been some dissatisfaction over APT’s...a.particular machi-ne (50)." "Software is the key to CNC , the costs of which are easily overlooked. The cost of software development is growing in relation to

Reducing maintenance costs in agreement with CNC machine tools reliability

NASA Astrophysics Data System (ADS)

Ungureanu, A. L.; Stan, G.; Butunoi, P. A.

2016-08-01

Aligning maintenance strategy with reliability is a challenge due to the need to find an optimal balance between them. Because the various methods described in the relevant literature involve laborious calculations or use of software that can be costly, this paper proposes a method that is easier to implement on CNC machine tools. The new method, called the Consequence of Failure Analysis (CFA) is based on technical and economic optimization, aimed at obtaining a level of required performance with minimum investment and maintenance costs.

Performance evaluation of OpenFOAM on many-core architectures

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

Brzobohatý, Tomáš; Říha, Lubomír; Karásek, Tomáš, E-mail: tomas.karasek@vsb.cz

In this article application of Open Source Field Operation and Manipulation (OpenFOAM) C++ libraries for solving engineering problems on many-core architectures is presented. Objective of this article is to present scalability of OpenFOAM on parallel platforms solving real engineering problems of fluid dynamics. Scalability test of OpenFOAM is performed using various hardware and different implementation of standard PCG and PBiCG Krylov iterative methods. Speed up of various implementations of linear solvers using GPU and MIC accelerators are presented in this paper. Numerical experiments of 3D lid-driven cavity flow for several cases with various number of cells are presented.

An avionics scenario and command model description for Space Generic Open Avionics Architecture (SGOAA)

NASA Technical Reports Server (NTRS)

Stovall, John R.; Wray, Richard B.

1994-01-01

This paper presents a description of a model for a space vehicle operational scenario and the commands for avionics. This model will be used in developing a dynamic architecture simulation model using the Statemate CASE tool for validation of the Space Generic Open Avionics Architecture (SGOAA). The SGOAA has been proposed as an avionics architecture standard to NASA through its Strategic Avionics Technology Working Group (SATWG) and has been accepted by the Society of Automotive Engineers (SAE) for conversion into an SAE Avionics Standard. This architecture was developed for the Flight Data Systems Division (FDSD) of the NASA Johnson Space Center (JSC) by the Lockheed Engineering and Sciences Company (LESC), Houston, Texas. This SGOAA includes a generic system architecture for the entities in spacecraft avionics, a generic processing external and internal hardware architecture, and a nine class model of interfaces. The SGOAA is both scalable and recursive and can be applied to any hierarchical level of hardware/software processing systems.

Vertical marginal gap evaluation of conventional cast and computer numeric controlled-milled titanium full-arch implant-supported frameworks.

PubMed

Alfadda, Sara A

2014-01-01

To use a novel approach to measure the amount of vertical marginal gap in computer numeric controlled (CNC)-milled titanium frameworks and conventional cast frameworks. Ten cast frameworks were fabricated on the mandibular master casts of 10 patients. Then, 10 CNC-milled titanium frameworks were fabricated by laser scanning the cast frameworks. The vertical marginal gap was measured and analyzed using the Contura-G2 coordinate measuring machine and special computer software. The CNC-milled titanium frameworks showed an overall reduced mean vertical gap compared with the cast frameworks in all five analogs. This difference was highly statistically significant in the distal analogs. The largest mean gap in the cast framework was recorded in the most distal analogs, and the least amount was in the middle analog. Neither of the two types of frameworks provided a completely gap-free superstructure. The CNCmilled titanium frameworks showed a significantly smaller vertical marginal gap than the cast frameworks.

Observations of condensation nuclei in the 1987 airborne Antarctic ozone experiment

NASA Technical Reports Server (NTRS)

Wilson, J. C.; Smith, S. D.; Ferry, G. V.; Loewenstein, M.

1988-01-01

The condensation nucleus counter (CNC) flown of the NASA ER-2 in the Airborne Antarctic Ozone Experiment provides a measurement of the number mixing ratio of particles which can be grown by exposure to supersaturated n-butyl alcohol vapor to diameters of a few microns. Such particles are referred to as condensation nuclei (CN). The ER-2 CNC was calibrated with aerosols of known size and concentration and was found to provide an accurate measure of the number concentration of particles larger than about 0.02 micron. Since the number distribution of stratospheric aerosols is usually dominated by particles less than a few tenths of micron in diameter, the upper cutoff of the ER-2 CNC has not been determined experimentally. However, theory suggests that the sampling and counting efficiency should remain near one for particles as large as 1 micron in diameter. Thus, the CN mixing ratio is usually a good measure of the mixing ratio of submicron particles.

Investigation on Effect of Material Hardness in High Speed CNC End Milling Process.

PubMed

Dhandapani, N V; Thangarasu, V S; Sureshkannan, G

2015-01-01

This research paper analyzes the effects of material properties on surface roughness, material removal rate, and tool wear on high speed CNC end milling process with various ferrous and nonferrous materials. The challenge of material specific decision on the process parameters of spindle speed, feed rate, depth of cut, coolant flow rate, cutting tool material, and type of coating for the cutting tool for required quality and quantity of production is addressed. Generally, decision made by the operator on floor is based on suggested values of the tool manufacturer or by trial and error method. This paper describes effect of various parameters on the surface roughness characteristics of the precision machining part. The prediction method suggested is based on various experimental analysis of parameters in different compositions of input conditions which would benefit the industry on standardization of high speed CNC end milling processes. The results show a basis for selection of parameters to get better results of surface roughness values as predicted by the case study results.

Site-Selective Modification of Cellulose Nanocrystals with Isophorone Diisocyanate and Formation of Polyurethane-CNC Composites.

PubMed

Girouard, Natalie M; Xu, Shanhong; Schueneman, Gregory T; Shofner, Meisha L; Meredith, J Carson

2016-01-20

The unequal reactivity of the two isocyanate groups in an isophorone diisocyante (IPDI) monomer was exploited to yield modified cellulose nanocrystals (CNCs) with both urethane and isocyanate functionality. The chemical functionality of the modified CNCs was verified with ATR-FTIR analysis and elemental analysis. The selectivity for the secondary isocyanate group using dibutyl tin dilaurate (DBTDL) as the reaction catalyst was confirmed with (13)C NMR. The modified CNCs showed improvements in the onset of thermal degradation by 35 °C compared to the unmodified CNCs. Polyurethane composites based on IPDI and a trifunctional polyether alcohol were synthesized using unmodified (um-CNC) and modified CNCs (m-CNC). The degree of nanoparticle dispersion was qualitatively assessed with polarized optical microscopy. It was found that the modification step facilitated superior nanoparticle dispersion compared to the um-CNCs, which resulted in increases in the tensile strength and work of fracture of over 200% compared to the neat matrix without degradation of elongation at break.

Cellulose nanocrystal-reinforced keratin bioadsorbent for effective removal of dyes from aqueous solution.

PubMed

Song, Kaili; Xu, Helan; Xu, Lan; Xie, Kongliang; Yang, Yiqi

2017-05-01

High-efficiency and recyclable three-dimensional bioadsorbents were prepared by incorporating cellulose nanocrystal (CNC) as reinforcements in keratin sponge matrix to remove dyes from aqueous solution. Adsorption performance of dyes by CNC-reinforced keratin bioadsorbent was improved significantly as a result of adding CNC as filler. Batch adsorption results showed that the adsorption capacities for Reactive Black 5 and Direct Red 80 by the bioadsorbent were 1201 and 1070mgg -1 , respectively. The isotherms and kinetics for adsorption of both dyes on bioadsorbent followed the Langmuir isotherm model and pseudo-second order model, respectively. Desorption and regeneration experiments showed that the removal efficiencies of the bioadsorbent for both dyes could remain above 80% at the fifth recycling cycles. Moreover, the bioadsorbent possessed excellent packed-bed column operation performance. Those results suggested that the adsorbent could be considered as a high-performance and promising candidate for dye wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Naturalistic Teenage Driving Study: Findings and Lessons Learned

PubMed Central

Simons-Morton, Bruce G.; Klauer, Sheila G.; Ouimet, Marie Claude; Guo, Feng; Albert, Paul S.; Lee, Suzanne E.; Ehsani, Johnathon P.; Pradhan, Anuj K.; Dingus, Thomas A.

2015-01-01

Problem This paper summarizes the findings on novice teenage driving outcomes (e.g., crashes and risky driving behaviors) from the Naturalistic Teenage Driving Study. Method Survey and driving data from a data acquisition system (Global Positioning System, accelerometers, cameras) were collected from 42 newly-licensed teenage drivers and their parents during the first 18 months of teenage licensure; stress responsivity was also measured in teenagers. Result Overall teenage crash and near crash (CNC) rates declined over time, but were >4 times higher among teenagers than adults. Contributing factors to teenage CNC rates included secondary task engagement (e.g., distraction), kinematic risky driving, low stress responsivity, and risky social norms. Conclusion The data support the contention that the high novice teenage CNC risk is due both to inexperience and risky driving behavior, particularly kinematic risky driving and secondary task engagement. Practical Applications Graduated driver licensing policy and other prevention efforts should focus on kinematic risky driving, secondary task engagement, and risky social norms. PMID:26403899

Multiband Photometric and Spectroscopic Analysis of HV Cnc

NASA Astrophysics Data System (ADS)

Gökay, G.; Gürol, B.; Derman, E.

2013-11-01

In this paper, radial velocity and VI- and JHKS - (Two Micron All Sky Survey) band photometric data of the detached system HV Cnc have been analyzed. The primary component of HV Cnc, which is a member of the M67 cluster, is suspected to be either a blue straggler or turn-off star. The system is a single-lined spectroscopic binary and its light curve shows a total eclipse. Spectroscopic observations of the system revealed the third component, which shows contribution to the total light of the system. Light curve and radial velocity data have been analyzed using the Wilson-Devinney (W-D) code and JHKS filter definitions computed for the W-D code in this work. Our analysis shows that the mass and radius of the primary and secondary components are 1.31 M ⊙, 0.52 M ⊙, 1.87 R ⊙, and 0.48 R ⊙, respectively. All results are compared with previously published literature values and discussed.

MULTIBAND PHOTOMETRIC AND SPECTROSCOPIC ANALYSIS OF HV Cnc

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

Gökay, G.; Gürol, B.; Derman, E., E-mail: ggokay@science.ankara.edu.tr

2013-11-01

In this paper, radial velocity and VI- and JHK{sub S} - (Two Micron All Sky Survey) band photometric data of the detached system HV Cnc have been analyzed. The primary component of HV Cnc, which is a member of the M67 cluster, is suspected to be either a blue straggler or turn-off star. The system is a single-lined spectroscopic binary and its light curve shows a total eclipse. Spectroscopic observations of the system revealed the third component, which shows contribution to the total light of the system. Light curve and radial velocity data have been analyzed using the Wilson-Devinney (W-D)more » code and JHK{sub S} filter definitions computed for the W-D code in this work. Our analysis shows that the mass and radius of the primary and secondary components are 1.31 M {sub ☉}, 0.52 M {sub ☉}, 1.87 R {sub ☉}, and 0.48 R {sub ☉}, respectively. All results are compared with previously published literature values and discussed.« less

Translocation of the cytoplasmic domain of ADAM13 to the nucleus is essential for Calpain-8 expression and cranial neural crest cell migration

PubMed Central

Cousin, Hélène; Abbruzzese, Genevieve; Kerdavid, Erin; Gaultier, Alban; Alfandari, Dominique

2011-01-01

Summary ADAMs are transmembrane metalloproteases that control cell behavior by cleaving both cell adhesion and signaling molecules. The cytoplasmic domain of ADAMs can regulate the proteolytic activity by controlling the subcellular localization and/or the activation of the protease domain. Here we show that the cytoplasmic domain of ADAM13 is cleaved and translocates into the nucleus. Preventing this translocation renders the protein incapable of promoting cranial neural crest (CNC) cell migration in vivo, without affecting its proteolytic activity. In addition, the cytoplasmic domain of ADAM13 regulates the expression of multiple genes in CNC, including the protease Calpain8-a. Restoring the expression of Calpain8-a is sufficient to rescue CNC migration in the absence of the ADAM13 cytoplasmic domain. This study shows that the cytoplasmic domain of ADAM metalloproteases can perform essential functions in the nucleus of cells and may contribute substantially to the overall function of the protein. PMID:21316592

Preparation and Properties of Electrospun Poly (Vinyl Pyrrolidone)/Cellulose Nanocrystal/Silver Nanoparticle Composite Fibers

PubMed Central

Huang, Siwei; Zhou, Ling; Li, Mei-Chun; Wu, Qinglin; Kojima, Yoichi; Zhou, Dingguo

2016-01-01

Poly (vinyl pyrrolidone) (PVP)/cellulose nanocrystal (CNC)/silver nanoparticle composite fibers were prepared via electrospinning using N,N′-dimethylformamide (DMF) as a solvent. Rheology, morphology, thermal properties, mechanical properties, and antimicrobial activity of nanocomposites were characterized as a function of material composition. The PVP/CNC/Ag electrospun suspensions exhibited higher conductivity and better rheological properties compared with those of the pure PVP solution. The average diameter of the PVP electrospun fibers decreased with the increase in the amount of CNCs and Ag nanoparticles. Thermal stability of electrospun composite fibers was decreased with the addition of CNCs. The CNCs help increase the composite tensile strength, while the elongation at break decreased. The composite fibers included Ag nanoparticles showed improved antimicrobial activity against both the Gram-negative bacterium Escherichia coli (E. coli) and the Gram-positive bacterium Staphylococcus aureus (S. aureus). The enhanced strength and antimicrobial performances of PVP/CNC/Ag electrospun composite fibers make the mat material an attractive candidate for application in the biomedical field. PMID:28773644

Investigation on Effect of Material Hardness in High Speed CNC End Milling Process

PubMed Central

Dhandapani, N. V.; Thangarasu, V. S.; Sureshkannan, G.

2015-01-01

This research paper analyzes the effects of material properties on surface roughness, material removal rate, and tool wear on high speed CNC end milling process with various ferrous and nonferrous materials. The challenge of material specific decision on the process parameters of spindle speed, feed rate, depth of cut, coolant flow rate, cutting tool material, and type of coating for the cutting tool for required quality and quantity of production is addressed. Generally, decision made by the operator on floor is based on suggested values of the tool manufacturer or by trial and error method. This paper describes effect of various parameters on the surface roughness characteristics of the precision machining part. The prediction method suggested is based on various experimental analysis of parameters in different compositions of input conditions which would benefit the industry on standardization of high speed CNC end milling processes. The results show a basis for selection of parameters to get better results of surface roughness values as predicted by the case study results. PMID:26881267

Multifunctional PLA-PHB/cellulose nanocrystal films: processing, structural and thermal properties.

PubMed

Arrieta, M P; Fortunati, E; Dominici, F; Rayón, E; López, J; Kenny, J M

2014-07-17

Cellulose nanocrystals (CNCs) synthesized from microcrystalline cellulose by acid hydrolysis were added into poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB) blends to improve the final properties of the multifunctional systems. CNC were also modified with a surfactant (CNCs) to increase the interfacial adhesion in the systems maintaining the thermal stability. Firstly, masterbatch pellets were obtained for each formulation to improve the dispersion of the cellulose structures in the PLA-PHB and then nanocomposite films were processed. The thermal stability as well as the morphological and structural properties of nanocomposites was investigated. While PHB increased the PLA crystallinity due to its nucleation effect, well dispersed CNC and CNCs not only increased the crystallinity but also improved the processability, the thermal stability and the interaction between both polymers especially in the case of the modified CNCs based PLA-PHB formulation. Likewise, CNCs were better dispersed in PLA-CNCs and PLA-PHB-CNCs, than CNC. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of sacrificial support fixture using deflection analysis

NASA Astrophysics Data System (ADS)

Ramteke, Ashwini M.; Ashtankar, Kishor M.

2018-04-01

Sacrificial support fixtures are the structures used to hold the part during machining while rotating the part about the fourth axis of CNC machining. In Four axis CNC machining part is held in a indexer which is rotated about the fourth axis of rotation. So using traditional fixturing devices to hold the part during machining such as jigs, v blocks and clamping plates needs a several set ups, manufacturing time which increase the cost associated with it. Since the part is rotated about the axis of rotation in four axis CNC machining so using traditional fixturing devices to hold the part while machining we need to reorient the fixture each time for particular orientation of part about the axis of rotation. So our proposed methodology of fixture design eliminates the cost associate with the complicated fixture design for customized parts which in turn reduces the time of manufacturing of the fixtures. But while designing the layout of the fixtures it is found out that the machining the part using four axis CNC machining the accurate machining of the part is directly proportional to the deflection produced in a part. So to machine an accurate part the deflection produced in a part should be minimum. We assume that the deflection produced in a part is a result of the deflection produced in a sacrificial support fixture while machining. So this paper provides the study of the deflection checking in a part machined using sacrificial support fixture by using FEA analysis.

Modeling and Analysis of CNC Milling Process Parameters on Al3030 based Composite

NASA Astrophysics Data System (ADS)

Gupta, Anand; Soni, P. K.; Krishna, C. M.

2018-04-01

The machining of Al3030 based composites on Computer Numerical Control (CNC) high speed milling machine have assumed importance because of their wide application in aerospace industries, marine industries and automotive industries etc. Industries mainly focus on surface irregularities; material removal rate (MRR) and tool wear rate (TWR) which usually depends on input process parameters namely cutting speed, feed in mm/min, depth of cut and step over ratio. Many researchers have carried out researches in this area but very few have taken step over ratio or radial depth of cut also as one of the input variables. In this research work, the study of characteristics of Al3030 is carried out at high speed CNC milling machine over the speed range of 3000 to 5000 r.p.m. Step over ratio, depth of cut and feed rate are other input variables taken into consideration in this research work. A total nine experiments are conducted according to Taguchi L9 orthogonal array. The machining is carried out on high speed CNC milling machine using flat end mill of diameter 10mm. Flatness, MRR and TWR are taken as output parameters. Flatness has been measured using portable Coordinate Measuring Machine (CMM). Linear regression models have been developed using Minitab 18 software and result are validated by conducting selected additional set of experiments. Selection of input process parameters in order to get best machining outputs is the key contributions of this research work.

Far Ultraviolet Spectroscopy of Three Long Period Nova-Like Variables, V363 Aur, AC Cnc and RZ Gru

NASA Astrophysics Data System (ADS)

Bisol, Alexandra; Sion, E. M.

2011-01-01

We have selected three nova-like variables: V363 Aur, RZ Gru and AC Cnc, all of which are UX UMa types, having similar orbital periods well beyond the 3 to 4 hour range where most nova-likes are found. All should have very similar secondary stars given the fact that they their physical parameters are so similar. V363 Aur is a bona fide SW Sex star, and AC Cnc is a probable one, while RZ Gru is not a member of the SW Sex subclass. Our objective is to carry out the first synthetic spectral analysis of far ultraviolet spectra of the three systems using state-of-the-art models both of accretion disks and photospheres. Therefore we shall compare the distances we obtain from the best fitting synthetic spectral models to other distance estimates in the literature. We present model-derived accretion rates and distances for all three systems. The FUV flux range of RZ Gru and V363 Aur is dominated by radiation from an optically thick, steady state, accretion but for AC Cnc, we find that a hot white dwarf accounts for 70% of the FUV flux. We compare the FUV characteristics and physical properties of these three long period nova-like systems to the properties of other nova-likes at shorter periods. This work was supported in part by NSF grant AST0807892 to Villanova University.

Superhumps and Repetitive Rebrightenings of the WZ Sge-Type Dwarf Nova, EG Cancri

NASA Astrophysics Data System (ADS)

Kato, Taichi; Nogami, Daisaku; Matsumoto, Katsura; Baba, Hajime

2004-03-01

We report on time-resolved photometric observations of the WZ Sge-type dwarf nova, EG Cnc (Huruhata's variable), during its superoutburst in 1996-1997. EG Cnc, after the main superoutburst accompanied by the development of superhumps typical of a WZ Sge-type dwarf nova, exhibited a series of six major rebrightenings. During these rebrightenings and the following long fading tail, EG Cnc persistently showed superhumps having a period equal to the superhump period observed during the main superoutburst. The persistent superhumps had a constant superhump flux with respect to the rebrightening phase. These findings suggest that the superhumps observed during the rebrightening stage and the fading tail are a ``remnant'' of the usual superhumps, and are not newly triggered by rebrightenings. By a comparison with the 1977 outburst of this object and outbursts of other WZ Sge-type dwarf novae, we propose an activity sequence of WZ Sge-type superoutbursts, in which the current outburst of EG Cnc is placed between a single-rebrightening event and distinct outbursts separated by a dip. The post-superoutburst behavior of WZ Sge-type dwarf novae can be understood in the presence of a considerable amount of remnant matter behind the cooling front in the outer accretion disk, even after the main superoutburst. We consider that a premature quenching of the hot state due to the weak tidal effect under the extreme mass ratio of the WZ Sge-type binary is responsible for the origin of the remnant mass.

Bioengineered Renal Cell Therapy Device for Clinical Translation

PubMed Central

Pino, Christopher J.; Westover, Angela J.; Buffington, Deborah A.; Humes, H. David

2016-01-01

The Bioartificial Renal Epithelial Cell System (BRECS), is a cell-based device to treat acute kidney injury through renal cell therapy from an extracorporeal circuit. To enable widespread implementation of cell therapy, the BRECS was designed to be cryopreserved as a complete device, cryostored, cryoshipped to an end-use site, thawed as a complete device, and employed in a therapeutic extracorporeal hemofiltration circuit. This strategy overcomes storage and distribution issues that have been previous barriers to cell therapy. Previous BRECS housings produced by Computer Numerical Control (CNC) machining, a slow process taking hours to produce one bioreactor, was also prohibitively expensive (>$600/CNC-BRECS); major obstacles to mass production. The goal of this study was to produce a BRECS to be mass produced by injection molding (IM-BRECS), decreasing cost (<$20/unit) and improving manufacturing speed (hundreds of units/hr), while maintaining the same cell therapy function as the previous CNC-BRECS, first evaluated through prototypes produced by stereolithography (SLA-BRECS). The finalized IM-BRECS design had a significantly lower fill volume (10 mL), mass (49 g) and footprint (8.5 cm×8.5 cm×1.5 cm), and was demonstrated to outperform the previous BRECS designs with respect to heat transfer, significantly improving control of cooling during cryopreservation and reducing thaw times during warming. During in vitro culture, IM-BRECS performed similarly to previous CNC-BRECS with respect to cell metabolic activity (lactate production, oxygen consumption and glutathione metabolism) and amount of cells supported. PMID:27922886

The study of optimization on process parameters of high-accuracy computerized numerical control polishing

NASA Astrophysics Data System (ADS)

Huang, Wei-Ren; Huang, Shih-Pu; Tsai, Tsung-Yueh; Lin, Yi-Jyun; Yu, Zong-Ru; Kuo, Ching-Hsiang; Hsu, Wei-Yao; Young, Hong-Tsu

2017-09-01

Spherical lenses lead to forming spherical aberration and reduced optical performance. Consequently, in practice optical system shall apply a combination of spherical lenses for aberration correction. Thus, the volume of the optical system increased. In modern optical systems, aspherical lenses have been widely used because of their high optical performance with less optical components. However, aspherical surfaces cannot be fabricated by traditional full aperture polishing process due to their varying curvature. Sub-aperture computer numerical control (CNC) polishing is adopted for aspherical surface fabrication in recent years. By using CNC polishing process, mid-spatial frequency (MSF) error is normally accompanied during this process. And the MSF surface texture of optics decreases the optical performance for high precision optical system, especially for short-wavelength applications. Based on a bonnet polishing CNC machine, this study focuses on the relationship between MSF surface texture and CNC polishing parameters, which include feed rate, head speed, track spacing and path direction. The power spectral density (PSD) analysis is used to judge the MSF level caused by those polishing parameters. The test results show that controlling the removal depth of single polishing path, through the feed rate, and without same direction polishing path for higher total removal depth can efficiently reduce the MSF error. To verify the optical polishing parameters, we divided a correction polishing process to several polishing runs with different direction polishing paths. Compare to one shot polishing run, multi-direction path polishing plan could produce better surface quality on the optics.

Design and optimization of a portable LQCD Monte Carlo code using OpenACC

NASA Astrophysics Data System (ADS)

Bonati, Claudio; Coscetti, Simone; D'Elia, Massimo; Mesiti, Michele; Negro, Francesco; Calore, Enrico; Schifano, Sebastiano Fabio; Silvi, Giorgio; Tripiccione, Raffaele

The present panorama of HPC architectures is extremely heterogeneous, ranging from traditional multi-core CPU processors, supporting a wide class of applications but delivering moderate computing performance, to many-core Graphics Processor Units (GPUs), exploiting aggressive data-parallelism and delivering higher performances for streaming computing applications. In this scenario, code portability (and performance portability) become necessary for easy maintainability of applications; this is very relevant in scientific computing where code changes are very frequent, making it tedious and prone to error to keep different code versions aligned. In this work, we present the design and optimization of a state-of-the-art production-level LQCD Monte Carlo application, using the directive-based OpenACC programming model. OpenACC abstracts parallel programming to a descriptive level, relieving programmers from specifying how codes should be mapped onto the target architecture. We describe the implementation of a code fully written in OpenAcc, and show that we are able to target several different architectures, including state-of-the-art traditional CPUs and GPUs, with the same code. We also measure performance, evaluating the computing efficiency of our OpenACC code on several architectures, comparing with GPU-specific implementations and showing that a good level of performance-portability can be reached.

The Pedagogic Architecture of MOOC: A Research Project on Educational Courses in Spanish

ERIC Educational Resources Information Center

Fernández-Díaz, Elia; Rodríguez-Hoyos, Carlos; Salvador, Adelina Calvo

2017-01-01

This study has been carried out within the context of the ECO European Project (E-learning, Communication Open-Data: Massive Mobile, Ubiquitous, and Open Learning) which is being financed by the European Union over four years (2014-17). It analyses the pedagogic architecture of MOOC on pedagogic/educational subjects in Spanish over one academic…

Delivering Savings with Open Architecture and Product Lines

DTIC Science & Technology

2011-04-30

p.m. Chair: Christopher Deegan , Executive Director, Program Executive Office for Integrated Warfare Systems Delivering Savings with Open...Architectures Walt Scacchi and Thomas Alspaugh, Institute for Software Research Christopher Deegan —Executive Director, Program Executive Officer...Integrated Warfare Systems (PEO IWS). Mr. Deegan directs the development, acquisition, and fleet support of 150 combat weapon system programs managed by 350

Advanced Bio-Based Nanocomposites and Manufacturing Processes

NASA Astrophysics Data System (ADS)

Spinella, Stephen Matthew

The aim of the PhD thesis concerns with the modification of cellulose nanocrystals (CNCs) via esterification or a radical grafting "from" approach to achieve polymeric nanocomposites of exceptional properties (Chapters 1 to 4). In addition to CNCs modification, other green routes have been introduced in this thesis in order to environmentally friendly polyester-based materials, i.e. Chapters five and six. The second chapter focuses on expanding on a one-pot cellulose acid hydrolysis/Fischer esterification to produce highly compatible CNCs without any organic solvent. It consists of modifying CNCs with acetic- and lactic- acid and exploring how such surface chemistry has an effect of dispersion in the case of polylactide (PLA)-based nanocomposites. The degree of substitution for AA-CNCs and LA-CNCs, determined by FTIR, are 0.12 and 0.13, respectively. PLA-based materials represent the best bioplastics relating to its high stiffness and biodegradability, but suffer from its poor thermal performances, namely its Heat Deflection Temperature (HDT). To improve the HDT of PLA, nanocomposites have been therefore prepared with modified cellulose nanocrystals (CNCs) by melt blending. After blending at 5 wt-% loading of CNCs, LA-CNCs gives superior reinforcement below and above the glass temperature of PLA. An increase in PLA's heat deflection temperature by 10°C and 20°C is achieved by melt-blending PLA with 5 and 20 wt-% LA-CNCs, respectively. Chapter three concerns with expanding this process to a series of hydrophilic and hydrophobic acids yielding functional CNCs for electronic and biomedical applications. Hydrophilic acids include citric-, malonic- and malic acid. Modification with the abovementioned organic acids allows for the introduction of free acids onto the surface of CNCs. Modification with citric-, malonic- and malic- acid is verified by Fourier Transform Infrared Spectroscopy and 13C solid state magic-angle spinning (MAS) NMR experiments. The degree of substation of modified CNCs is determined by quantitative direct carbon MAS NMR for malonate CNCs, malate CNCs and Citrate CNCs are found to be 0.16, 0.22 and 0.18, respectively. Re-hydrolysis experiments are performed and the yield of citrate CNCs was increased to 55% with little effect on CNC crystallinity or morphology. Citrate CNCs are then used for a myriad of applications such as polymer reinforcement (polyvinyl alcohol (PVOH) and bio-temptation of inorganic nanoparticles. Introduction of just 1% citrate CNCs results in a 40°C increase in PVOH's thermal stability (T50%). Appendant citrate groups are used for the direct reduction of silver nanoparticles without any external reducing agents. Finally citrate CNCs are used to reinforce collagen hydrogels. Chapter four builds on "grafting from" reactions of poly(methyl methacrylate) (PMMA) onto the surface of CNCs to further increase the HDT of PLAs above 100°C. Taking advantage of the PMMA-PLLA miscibility, the presence of PMMA grafts on the CNC surface clearly improves CNC dispersion in PLLA, and reduces CNC aggregation thus enhancing the PLAs HDT. Herein "grafting from" reactions of poly(methyl methacrylate) (PMMA) on the surface of CNCs was is performed by free-radical grafting in water using two different redox initiators: Fe2+/H2O2 (Fenton's reagent) and ceric ammonium nitrate (CAN). The amount of grafted PMMA could be easily tuned according to the initiator and CAN clearly represents the most efficient initiator. From rheological data, high grafting levels favor the percolation of CNC with the development of a long-range 3D network. PLA's (HDT) higher was increased to over 130°C. Chapter five reports blending PLA with another renewable poly(o-hydroxytetradecanoic acid) (PC14).The goal of this chapter is to enhance the poor brittleness of PLA by blending with a rubbery polymer such as PC14. Like most polymer blends, PLA and PC14 are however found to be immiscible by simple blending. To achieve this goal, a fully bio-sourced PLA based polymer blend is conceived by incorporating small quantities of poly(o-hydroxytetradecanoic acid) (PC14). PC14 is produced by polycondensation, thus we explore ring opening polymerization of poly(w-pentadecalactone) using enzymatic reactive extrusion. The final chapter of this thesis concerns the feasibility of conducting an enzymatic ring-opening polymerization on the basis of lipase enzymes by reactive extrusion (REX) at high shear and temperature conditions. The ability of lipases to catalyze ring-opening and condensation polymerizations at relatively low temperatures (e.g. 70--90°C) is advantageous to reduce energy input and to preserve thermally sensitive chemical moieties. However, when high molecular weight polymer synthesis is desired, corresponding diffusional constraints must be overcome by either running reactions at higher temperatures (e.g. 150--220°C) or by adding solvent. Reactive extrusion (REX) has been used to overcome the aforementioned problems of bulk polymerizations that slows chain growth. In the chapter using immobilized Candida antarctica Lipase B (CALB) as catalyst at temperatures ranging from 90 to 130°C is investigated. (Abstract shortened by UMI.).

High-Power Copper Gratings for a Sheet-Beam Traveling-Wave Amplifier at G-Band

DTIC Science & Technology

2013-01-01

respectively). A. Two-Port CTF The CTF was CNC machined from OFHC copper. The gratings were tightly clamped into place in the fixture. The results of the... CNC machined such that only ten slots were exposed, followed by a short for the rest of the grating. Adaptors to standard WR5 and WR10 waveguides were...of low-voltage grating Cerenkov amplifiers,” Phys. Plasmas , vol. 1, no. 1, pp. 176–188, Jan. 1994. [11] C. D. Joye, J. P. Calame, K. T. Nguyen, and M

Coupled Chiral Structure in Graphene-Based Film for Ultrahigh Thermal Conductivity in Both In-Plane and Through-Plane Directions.

PubMed

Meng, Xin; Pan, Hui; Zhu, Chengling; Chen, Zhixin; Lu, Tao; Xu, Da; Li, Yao; Zhu, Shenmin

2018-06-21

The development of high-performance thermal management materials to dissipate excessive heat both in plane and through plane is of special interest to maintain efficient operation and prolong the life of electronic devices. Herein, we designed and constructed a graphene-based composite film, which contains chiral liquid crystals (cellulose nanocrystals, CNCs) inside graphene oxide (GO). The composite film was prepared by annealing and compacting of self-assembled GO-CNC, which contains chiral smectic liquid crystal structures. The helical arranged nanorods of carbonized CNC act as in-plane connections, which bridge neighboring graphene sheets. More interestingly, the chiral structures also act as through-plane connections, which bridge the upper and lower graphene layers. As a result, the graphene-based composite film shows extraordinary thermal conductivity, in both in-plane (1820.4 W m -1 K -1 ) and through-plane (4.596 W m -1 K -1 ) directions. As a thermal management material, the heat dissipation and transportation behaviors of the composite film were investigated using a self-heating system and the results showed that the real-time temperature of the heater covered with the film was 44.5 °C lower than a naked heater. The prepared film shows a much higher efficiency of heat transportation than the commonly used thermal conductive Cu foil. Additionally, this graphene-based composite film exhibits excellent mechanical strength of 31.6 MPa and an electrical conductivity of 667.4 S cm -1 . The strategy reported here may open a new avenue to the development of high-performance thermal management films.

An OER Architecture Framework: Needs and Design

ERIC Educational Resources Information Center

Khanna, Pankaj; Basak, P. C.

2013-01-01

This paper describes an open educational resources (OER) architecture framework that would bring significant improvements in a well-structured and systematic way to the educational practices of distance education institutions of India. The OER architecture framework is articulated with six dimensions: pedagogical, technological, managerial,…

Open architecture CMM motion controller

NASA Astrophysics Data System (ADS)

Chang, David; Spence, Allan D.; Bigg, Steve; Heslip, Joe; Peterson, John

2001-12-01

Although initially the only Coordinate Measuring Machine (CMM) sensor available was a touch trigger probe, technological advances in sensors and computing have greatly increased the variety of available inspection sensors. Non-contact laser digitizers and analog scanning touch probes require very well tuned CMM motion control, as well as an extensible, open architecture interface. This paper describes the implementation of a retrofit CMM motion controller designed for open architecture interface to a variety of sensors. The controller is based on an Intel Pentium microcomputer and a Servo To Go motion interface electronics card. Motor amplifiers, safety, and additional interface electronics are housed in a separate enclosure. Host Signal Processing (HSP) is used for the motion control algorithm. Compared to the usual host plus DSP architecture, single CPU HSP simplifies integration with the various sensors, and implementation of software geometric error compensation. Motion control tuning is accomplished using a remote computer via 100BaseTX Ethernet. A Graphical User Interface (GUI) is used to enter geometric error compensation data, and to optimize the motion control tuning parameters. It is shown that this architecture achieves the required real time motion control response, yet is much easier to extend to additional sensors.

Defense Against National Vulnerabilities in Public Data

DTIC Science & Technology

2017-02-28

ingestion of subscription based precision data sources ( Business Intelligence Databases, Monster, others).  Flexible data architecture that allows for... Architecture Objective: Develop a data acquisition architecture that can successfully ingest 1,000,000 records per hour from up to 100 different open...data sources.  Developed and operate a data acquisition architecture comprised of the four following major components:  Robust website

Distributed chemical computing using ChemStar: an open source java remote method invocation architecture applied to large scale molecular data from PubChem.

PubMed

Karthikeyan, M; Krishnan, S; Pandey, Anil Kumar; Bender, Andreas; Tropsha, Alexander

2008-04-01

We present the application of a Java remote method invocation (RMI) based open source architecture to distributed chemical computing. This architecture was previously employed for distributed data harvesting of chemical information from the Internet via the Google application programming interface (API; ChemXtreme). Due to its open source character and its flexibility, the underlying server/client framework can be quickly adopted to virtually every computational task that can be parallelized. Here, we present the server/client communication framework as well as an application to distributed computing of chemical properties on a large scale (currently the size of PubChem; about 18 million compounds), using both the Marvin toolkit as well as the open source JOELib package. As an application, for this set of compounds, the agreement of log P and TPSA between the packages was compared. Outliers were found to be mostly non-druglike compounds and differences could usually be explained by differences in the underlying algorithms. ChemStar is the first open source distributed chemical computing environment built on Java RMI, which is also easily adaptable to user demands due to its "plug-in architecture". The complete source codes as well as calculated properties along with links to PubChem resources are available on the Internet via a graphical user interface at http://moltable.ncl.res.in/chemstar/.

[CNC proteins in physiology and pathology].

PubMed

Gęgotek, Agnieszka; Skrzydlewska, Elżbieta

2015-07-06

CNC proteins consist of Bach1, Bach2 and 4 homologous transcription factors: Nrf1, Nrf2, Nrf3 and p45NF-E2. Transcription factors belonging to this group of proteins play a crucial role in protection of cells against oxidative stress. Under physiological conditions, they remain in the cytoplasm in the inactive form or are degraded. However, in oxidative stress conditions, they are translocated to the nucleus, and bind to DNA in the ARE sequence. Consequently, there is transcription of genes encoding cytoprotective proteins, such as phase II enzymes, or low molecular weight antioxidant proteins (i.e., thioredoxin, ferritin, metallothionein) responsible for protecting cells from reactive oxygen species (ROS) action. The activity of transcriptional proteins depends directly on the redox state of the cell. ROS as second messenger signals, control inhibitors of cytoplasmic CNC proteins or potentiate the activity of kinases (MAPK, PKC, PI3K, PERK), leading to phosphorylation of transcription factors. This is conducive to translocation of these molecules into the nucleus and to formation of complexes that initiate the gene expression. Disorders of regulation of the activity of transcription factors belonging to the CNC proteins caused by gene mutations, epigenetic modifications or increased activity of p62, p21, or k-Ras, B-Raf and c-Myc oncogenes, induce changes in the level of ARE-dependent gene expression, which can lead even to the development of carcinogenesis. On the other hand, Nrf transcription factors, inducing the expression of antioxidants and enzymes responsible for the detoxification of xenobiotics, can be considered as a potential target of the action of chemopreventive factors in anticancer therapy.

Genotoxic and immunotoxic effects of cellulose nanocrystals in vitro.

PubMed

Catalán, Julia; Ilves, Marit; Järventaus, Hilkka; Hannukainen, Kati-Susanna; Kontturi, Eero; Vanhala, Esa; Alenius, Harri; Savolainen, Kai M; Norppa, Hannu

2015-03-01

Nanocellulosics are among the most promising innovations for a wide-variety of applications in materials science. Although nanocellulose is presently produced only on a small scale, its possible toxic effects should be investigated at this early stage. The aim of the present study was to examine the potential genotoxicity and immunotoxicity of two celluloses in vitro - cellulose nanocrystals (CNC; mean fibril length 135 nm, mean width 7.3 nm) and a commercially available microcrystalline (non-nanoscale) cellulose (MCC; particle size ∼50 µm). Both celluloses showed 55% cytotoxicity at approximately 100 µg/ml after 4-h, 24-h, and 48-h treatment of human bronchial epithelial BEAS 2B cells, as determined by luminometric detection of ATP and cell count (dead cells identified by propidium iodide). Neither of the materials was able to induce micronuclei (MN) in binucleate or mononucleate BEAS 2B cells after a 48-h treatment (2.5-100 µg/ml). In human monocyte-derived macrophages, MCC induced a release (measured by enzyme-linked immunosorbent assay; ELISA) of the pro-inflammatory cytokines tumor necrosis factor α (TNF-α) and (after lipopolysaccharide-priming) interleukin 1β (IL-1β) after a 6-h exposure to a dose of 300 µg/ml, but CNC (30-300 µg/ml) did not. In conclusion, our results show that nanosized CNC is neither genotoxic nor immunotoxic under the conditions tested, whereas non-nanosized MCC is able to induce an inflammatory response. More studies are needed, especially in vivo, to further assess if CNC and other nanocelluloses induce secondary genotoxic effects mediated by inflammation. © 2014 Wiley Periodicals, Inc.

A new comprehensive technique of catheterisation, blood sampling, sample preparation and sample analysis by means of high-pressure liquid chromatography for pharmacokinetic studies with estradiol-linked nitrosoureas and their metabolites.

PubMed

Betsch, B; Berger, M R; Spiegelhalder, B

1990-09-01

Estradiol-linked nitrosoureas are offering new perspectives in the antineoplastic chemotherapy of estradiol-receptor positive mammary carcinomas. In such a molecule estradiol has the function of a carrier which brings about a specific accumulation of the anticancer drug in estradiol-receptor containing tumor cells. However, there is only little knowledge about the pharmacokinetic behavior of this new group of anticancer agents. For that reason a new comprehensive technique of catheterisation, blood sampling, sample preparation and sample analysis with high-pressure liquid chromatography (HPLC) for preclinical pharmacokinetic studies with estradiol-linked nitrosoureas and their metabolites has been developed. N-(2-Chloroethyl)-N-nitroso-carbamoyl-L-alanine-estradiol-17-ester (CNC-alanine-estradiol-17-ester) and N-(2-chloroethyl)-N-nitroso-carbamoyl-L-alanine (CNC-alanine) were used as test compounds. The drugs were tested in female Sprague-Dawley rats with chemically induced mammary carcinomas. The laboratory animals were supplied with two catheters prior to the pharmacokinetic experiments. The blood samples were drawn from the vena cava catheter after the drug had been applied through a vena jugularis catheter. The compounds were extracted from plasma with C18 silicagel reversed phase cartridges. The clean-up technique delivered clear samples only slightly contaminated with the biological matrix. The recovery from plasma was 75 +/- 5% for the hormone-linked CNC-alanine-estradiol-17-ester and 70 +/- 5% for the unlinked CNC-alanine. The analysis was carried out by means of HPLC.(ABSTRACT TRUNCATED AT 250 WORDS)

Chiral nematic porous germania and germanium/carbon films

NASA Astrophysics Data System (ADS)

Xu, Jing; Nguyen, Thanh-Dinh; Xie, Kai; Hamad, Wadood Y.; MacLachlan, Mark J.

2015-07-01

We report our extensive attempts and, ultimately, success to produce crack-free, chiral nematic GeO2/cellulose nanocrystal (CNC) composite films with tunable photonic properties from the controlled assembly of germanium(iv) alkoxides with the lyotropic liquid-crystalline CNCs in a mixed solvent of water/DMF. With different pyrolysis conditions, the photonic GeO2/CNC composites can be converted into freestanding chiral nematic films of amorphous GeO2, and semiconducting mesoporous GeO2/C and Ge/C replicas. These new materials are promising for chiral separation, enantioselective adsorption, catalysis, sensing, optoelectronics, and lithium ion batteries. Furthermore, the new, reproducible synthesis strategies developed may be applicable for constructing other composites and porous materials with chiral nematic ordering.We report our extensive attempts and, ultimately, success to produce crack-free, chiral nematic GeO2/cellulose nanocrystal (CNC) composite films with tunable photonic properties from the controlled assembly of germanium(iv) alkoxides with the lyotropic liquid-crystalline CNCs in a mixed solvent of water/DMF. With different pyrolysis conditions, the photonic GeO2/CNC composites can be converted into freestanding chiral nematic films of amorphous GeO2, and semiconducting mesoporous GeO2/C and Ge/C replicas. These new materials are promising for chiral separation, enantioselective adsorption, catalysis, sensing, optoelectronics, and lithium ion batteries. Furthermore, the new, reproducible synthesis strategies developed may be applicable for constructing other composites and porous materials with chiral nematic ordering. Electronic supplementary information (ESI) available: TGA, IR, Raman, TEM, SEM, BET. See DOI: 10.1039/c5nr02520f

Architectural Terms for Educational Planners.

ERIC Educational Resources Information Center

1997

This booklet is designed to facilitate open, clear communication between educational facility planners and the architects hired to oversee building design and construction. It provides a list of architectural, electrical, plumbing, and topographical symbols; a glossary of architectural terms; and a list of public agencies and relevant codes and…

Full Chain Benchmarking for Open Architecture Airborne ISR Systems: A Case Study for GMTI Radar Applications

DTIC Science & Technology

2015-09-15

middleware implementations via a common object-oriented software hierarchy, with library -specific implementations of the five GMTI benchmark ...Full-Chain Benchmarking for Open Architecture Airborne ISR Systems A Case Study for GMTI Radar Applications Matthias Beebe, Matthew Alexander...time performance, effective benchmarks are necessary to ensure that an ARP system can meet the mission constraints and performance requirements of

Advances in the Acquisition of Secure Systems Based on Open Architectures

DTIC Science & Technology

2011-04-30

2011 11:15 a.m. – 12:45 p.m. Chair: Christopher Deegan , Executive Director, Program Executive Office for Integrated Warfare Systems Delivering...Systems Based on Open Architectures Walt Scacchi and Thomas Alspaugh, Institute for Software Research Christopher Deegan —Executive Director, Program...Executive Officer, Integrated Warfare Systems (PEO IWS). Mr. Deegan directs the development, acquisition, and fleet support of 150 combat weapon system

Canes Implementation: Analysis of Budgetary, Business, and Policy Challenges

DTIC Science & Technology

2014-12-01

Concept of Operations COTS Commercial Off the Shelf DAG Defense Acquisitions Guidebook DAS Defense Acquisitions System DOD Department of Defense...and Integration NSS National Security Strategy OA Open Architecture OCO Overseas Contingency Operations OEF Operation Enduring Freedom OIF...and software and civilian-type open architecture ( OA ) presents a series of challenges. The purpose of this report is to provide the Navy with a

Step-and-Repeat Nanoimprint-, Photo- and Laser Lithography from One Customised CNC Machine.

PubMed

Greer, Andrew Im; Della-Rosa, Benoit; Khokhar, Ali Z; Gadegaard, Nikolaj

2016-12-01

The conversion of a computer numerical control machine into a nanoimprint step-and-repeat tool with additional laser- and photolithography capacity is documented here. All three processes, each demonstrated on a variety of photoresists, are performed successfully and analysed so as to enable the reader to relate their known lithography process(es) to the findings. Using the converted tool, 1 cm(2) of nanopattern may be exposed in 6 s, over 3300 times faster than the electron beam equivalent. Nanoimprint tools are commercially available, but these can cost around 1000 times more than this customised computer numerical control (CNC) machine. The converted equipment facilitates rapid production and large area micro- and nanoscale research on small grants, ultimately enabling faster and more diverse growth in this field of science. In comparison to commercial tools, this converted CNC also boasts capacity to handle larger substrates, temperature control and active force control, up to ten times more curing dose and compactness. Actual devices are fabricated using the machine including an expanded nanotopographic array and microfluidic PDMS Y-channel mixers.

Electrospun Nanofibers Made of Silver Nanoparticles, Cellulose Nanocrystals, and Polyacrylonitrile as Substrates for Surface-Enhanced Raman Scattering

PubMed Central

Ren, Suxia; Dong, Lili; Zhang, Xiuqiang; Lei, Tingzhou; Ehrenhauser, Franz; Song, Kunlin; Li, Meichun; Sun, Xiuxuan; Wu, Qinglin

2017-01-01

Nanofibers with excellent activities in surface-enhanced Raman scattering (SERS) were developed through electrospinning precursor suspensions consisting of polyacrylonitrile (PAN), silver nanoparticles (AgNPs), silicon nanoparticles (SiNPs), and cellulose nanocrystals (CNCs). Rheology of the precursor suspensions, and morphology, thermal properties, chemical structures, and SERS sensitivity of the nanofibers were investigated. The electrospun nanofibers showed uniform diameters with a smooth surface. Hydrofluoric (HF) acid treatment of the PAN/CNC/Ag composite nanofibers (defined as p-PAN/CNC/Ag) led to rougher fiber surfaces with certain pores and increased mean fiber diameters. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results confirmed the existence of AgNPs that were formed during heat and HF acid treatment processes. In addition, thermal stability of the electrospun nanofibers increased due to the incorporation of CNCs and AgNPs. The p-PAN/CNC/Ag nanofibers were used as a SERS substrate to detect p-aminothiophenol (p-ATP) probe molecule. The results show that this substrate exhibited high sensitivity for the p-ATP probe detection. PMID:28772428

The effect of CNC and manual laser machining on electrical resistance of HDPE/MWCNT composite

NASA Astrophysics Data System (ADS)

Mohammadi, Fatemeh; Farshbaf Zinati, Reza; Fattahi, A. M.

2018-05-01

In this study, electrical conductivity of high-density polyethylene (HDPE)/multi-walled carbon nanotube (MWCNT) composite was investigated after laser machining. To this end, produced using plastic injection process, nano-composite samples were laser machined with various combinations of input parameters such as feed rate (35, 45, and 55 mm/min), feed angle with injection flow direction (0°, 45°, and 90°), and MWCNT content (0.5, 1, and 1.5 wt%). The angle between laser feed and injected flow direction was set via either of two different methods: CNC programming and manual setting. The results showed that the parameters of angle between laser line and melt flow direction and feed rate were both found to have statistically significance and physical impacts on electrical resistance of the samples in manual setting. Also, maximum conductivity was seen when the angle between laser line and melt flow direction was set to 90° in manual setting, and maximum conductivity was seen at feed rate of 55 mm/min in both of CNC programming and manual setting.

Step-and-Repeat Nanoimprint-, Photo- and Laser Lithography from One Customised CNC Machine

NASA Astrophysics Data System (ADS)

Greer, Andrew IM; Della-Rosa, Benoit; Khokhar, Ali Z.; Gadegaard, Nikolaj

2016-03-01

The conversion of a computer numerical control machine into a nanoimprint step-and-repeat tool with additional laser- and photolithography capacity is documented here. All three processes, each demonstrated on a variety of photoresists, are performed successfully and analysed so as to enable the reader to relate their known lithography process(es) to the findings. Using the converted tool, 1 cm2 of nanopattern may be exposed in 6 s, over 3300 times faster than the electron beam equivalent. Nanoimprint tools are commercially available, but these can cost around 1000 times more than this customised computer numerical control (CNC) machine. The converted equipment facilitates rapid production and large area micro- and nanoscale research on small grants, ultimately enabling faster and more diverse growth in this field of science. In comparison to commercial tools, this converted CNC also boasts capacity to handle larger substrates, temperature control and active force control, up to ten times more curing dose and compactness. Actual devices are fabricated using the machine including an expanded nanotopographic array and microfluidic PDMS Y-channel mixers.

Photo-driven nanoactuators based on carbon nanocoils and vanadium dioxide bimorphs.

PubMed

Ma, He; Zhang, Xinping; Cui, Ruixue; Liu, Feifei; Wang, Meng; Huang, Cuiying; Hou, Jiwei; Wang, Guang; Wei, Yang; Jiang, Kaili; Pan, Lujun; Liu, Kai

2018-06-06

Photo-driven actuators are highly desirable in various smart systems owing to the advantages of wireless control and possible actuation by solar energy. Miniaturization of photo-driven actuators is particularly essential in micro-robotics and micro-/nano-electro-mechanical systems. However, it remains a great challenge to build up nano-scale photo-driven actuators with competitive performance in amplitude, response speed, and lifetime. In this work, we developed photo-driven nanoactuators based on bimorph structures of vanadium dioxides (VO2) and carbon nanocoils (CNCs). Activated by the huge structural phase transition of VO2, the photo-driven VO2/CNC nanoactuators deliver a giant amplitude, a fast response up to 9400 Hz, and a long lifetime more than 10 000 000 actuation cycles. Both experimental and simulation results show that the helical structure of CNCs enables a low photo-driven threshold of VO2/CNC nanoactuators, which provides an effective method to construct photo-driven nanoactuators with low power consumption. Our photo-driven VO2/CNC nanoactuators would find potential applications in nano-scale electrical/optical switches and other smart devices.

Development of three-axis inkjet printer for gear sensors

NASA Astrophysics Data System (ADS)

Iba, Daisuke; Rodriguez Lopez, Ricardo; Kamimoto, Takahiro; Nakamura, Morimasa; Miura, Nanako; Iizuka, Takashi; Masuda, Arata; Moriwaki, Ichiro; Sone, Akira

2016-04-01

The long-term objective of our research is to develop sensor systems for detection of gear failure signs. As a very first step, this paper proposes a new method to create sensors directly printed on gears by a printer and conductive ink, and shows the printing system configuration and the procedure of sensor development. The developing printer system is a laser sintering system consisting of a laser and CNC machinery. The laser is able to synthesize micro conductive patterns, and introduced to the CNC machinery as a tool. In order to synthesize sensors on gears, we first design the micro-circuit pattern on a gear through the use of 3D-CAD, and create a program (G-code) for the CNC machinery by CAM. This paper shows initial experiments with the laser sintering process in order to obtain the optimal parameters for the laser setting. This new method proposed here may provide a new manufacturing process for mechanical parts, which have an additional functionality to detect failure, and possible improvements include creating more economical and sustainable systems.

The Multi-Scale Environment of RS Cnc from CO and HI Observations

NASA Astrophysics Data System (ADS)

Hoai, D. T.; Matthews, L. D.; Winters, J. M.; Nhung, P. T.; Gérard, E.; Libert, Y.; Le Bertre, T.

2015-08-01

We present a detailed study of the circumstellar gas distribution and kinematics of the semi-regular variable star RS Cnc on spatial scales ranging from ˜1″ (˜150 AU) to ˜6' (˜0.24 pc). The close environment of RS Cnc (from 1 to 20″) can be described with a model in which the density and velocity vary smoothly from the equatorial plane to the polar axis. In this model the mass loss rate is higher along the polar directions than in the equatorial plane, which does not favor current models invoking stellar rotation or a magnetic field as the cause of the axi-symmetry. Outside this region, the study of which is limited by the photo-dissociation of CO, HI data at 21 cm show that the flow is slowed down at a typical distance of 1' (˜0.04 pc). Further away (1 to 6', or 0.04 to 0.24 pc), the flow is distorted by the relative motion of the star with respect to the interstellar medium.

Lymphatic Malformation Architecture: Implications for Treatment With OK-432.

PubMed

Malic, Claudia C; Guilfoyle, Regan; Courtemanche, Rebecca J M; Arneja, Jugpal S; Heran, Manraj K S; Courtemanche, Douglas J

2017-10-01

Herein, the authors aim to describe their findings of novel architectural types of lymphatic malformations (LM) and explain the relationship between these architectures and OK-432 treatment outcomes. A retrospective review was conducted of all patients diagnosed with a LM treated with OK-432 at the Vascular Anomalies Clinic at BC Children's Hospital from December 2002 to January 2012. Twenty-seven patients were included in the study. Sixty percent of lesions were present by 2 years of age with the majority located in the head and neck (59%). The average number of sclerotherapy procedures was 1.4 per patient. Treatment under fluoroscopic guidance revealed 3 new LM architectures: open-cell microcystic, closed-cell microcystic, and lymphatic channel. Response to treatment was complete or good for 14/19 macrocystic and for 1/2 mixed lesions. Open-cell microcystic LMs gave a complete or good response for 3/3, which was attributed to OK-432 freely communicating between cysts. Closed-cell microcystic LM had localized cysts that did not allow OK-432 to freely communicate and were associated with partial responses, 2/2. The lymphatic channel had a partial response. There were 2 minor complications and 1 instance of recurrence. The identification of 3 new LM architectures expands the current accepted classification to include: open-cell microcystic, closed-cell microcystic, and lymphatic channels. The majority of complete responses to OK-432 were found with macrocystic lesions. Open-cell microcystic lesions respond better to OK-432 than closed-cell microcystic lesions, and lymphatic channels may respond to OK-432. These key architecture-response relationships have direct clinical implications for treatment with OK-432 sclerotherapy.

Teaching Creative Thinking through Architectural Design

ERIC Educational Resources Information Center

Jeon, Kijeong; Cotner, Teresa L.

2010-01-01

Art and art education are open to broader definitions in the twenty-first century. It is time that teachers seriously think about including built environment design in K-12 art education. The term "built environment" includes interior design, architecture, landscape architecture, and urban planning. Due to increased exposure to built environment…

39 CFR 501.7 - Postage Evidencing System requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Information-Based Indicia and Security Architecture for Open IBI Postage Evidencing Systems or Performance Criteria for Information-Based Indicia and Security Architecture for Closed IBI Postage Metering Systems...

Future internet architecture and cloud ecosystem: A survey

NASA Astrophysics Data System (ADS)

Wan, Man; Yin, Shiqun

2018-04-01

The Internet has gradually become a social infrastructure, the existing TCP/IP architecture faces many challenges. So future Internet architecture become hot research. This paper introduces two ways of idea about the future research of Internet structure system, probes into the future Internet architecture and the environment of cloud ecosystem. Finally, we focuses the related research, and discuss basic principles and problems of OpenStack.

Proceedings of the Second Software Architecture Technology User Network (SATURN) Workshop

DTIC Science & Technology

2006-08-01

Proceedings of the Second Software Architecture Technology User Network (SATURN) Workshop Robert L. Nord August 2006 TECHNICAL REPORT CMU...SEI-2006-TR-010 ESC-TR-2006-010 Software Architecture Technology Initiative Unlimited distribution subject to the copyright. This report was...Participants 3 3 Presentations 5 3.1 SATURN Opening Presentation: Future Directions of the Software Architecture Technology Initiative 5 3.2 Keynote

Computer numeric control generation of toric surfaces

NASA Astrophysics Data System (ADS)

Bradley, Norman D.; Ball, Gary A.; Keller, John R.

1994-05-01

Until recently, the manufacture of toric ophthalmic lenses relied largely upon expensive, manual techniques for generation and polishing. Recent gains in computer numeric control (CNC) technology and tooling enable lens designers to employ single- point diamond, fly-cutting methods in the production of torics. Fly-cutting methods continue to improve, significantly expanding lens design possibilities while lowering production costs. Advantages of CNC fly cutting include precise control of surface geometry, rapid production with high throughput, and high-quality lens surface finishes requiring minimal polishing. As accessibility and affordability increase within the ophthalmic market, torics promise to dramatically expand lens design choices available to consumers.

In Papillary Thyroid Cancer, Preoperative Central Neck Ultrasound Detects Only Macroscopic Surgical Disease, But Negative Findings Predict Excellent Long-Term Regional Control and Survival

PubMed Central

Moreno, Mauricio A.; Edeiken-Monroe, Beth S.; Siegel, Eric R.; Sherman, Steven I.

2012-01-01

Background Ultrasound (US) of the central neck compartment (CNC) is considered of limited sensitivity for nodal spread in papillary thyroid cancer (PTC); elective neck dissection is commonly advocated even in the absence of sonographic abnormalities. We hypothesized that US is an accurate predictor for long-term disease-free survival, regardless of the use of elective central neck dissection in patients with PTC. Methods A retrospective chart review of 331 consecutive PTC patients treated with total thyroidectomy at M.D. Anderson Cancer Center between 1996 and 2003 was performed. Information retrieved included preoperative sonographic status of the CNC, surgical treatment of the neck, demographics, cancer staging, histopathological variables and use of adjuvant treatment. The endpoints for the study were nodal recurrence and survival. Results There were 112 males and 219 females with a median age of 44 years (range 11–87). The median follow-up time for the series was 71.5 months (range 12.7–148.7). There were 151 (45.6%) patients with a T1, 58 (17.5%) with a T2, 70 (21.1%) with a T3, and 52 (15.7%) with a T4. Preoperative sonographic abnormalities were present in the CNC in 79 (23.9%) patients. During the surveillance period, 11 (3.2%) patients recurred in the central neck, with an average time for recurrence of 22.8 months. Advanced T stage (T3/T4) and abnormal US were independent prognostic factors for recurrence in the central neck (p=0.013 and p=0.005 respectively). There were 119 (35%) patients with a sonographically negative central compartment who underwent elective central neck dissection; 85 of them (71.4%) were found to be histopathologically N(+) while 34 (28.6%) were pN0. There were no differences in overall survival (p=0.32), disease specific survival (DSS; p=0.49), and recurrence-free survival (p=0.32) between these two groups. Preoperative US of the CNC was an age-independent predictor for overall survival (p<0.001), DSS (p=0.0097), and disease-free survival (p=0.0005) on bivariate Cox regression. Conclusions US of the central compartment is an age-independent predictor for survival and CNC recurrence-free survival in PTC. Prophylactic neck dissection of the central compartment does not improve long-term disease control, regardless of the histopathological status of the lymph nodes retrieved. Our findings emphasize the ability of US to clinically detect relevant nodal disease and support conservative management of the CNC in the absence of abnormal findings. PMID:22280230

Optical and X-ray studies of chromospherically active stars: FR Cancri, HD 95559 and LO Pegasi

NASA Technical Reports Server (NTRS)

Pandey, J. C.; Singh, K. P.; Drake, S. A.; Sagar, R.

2005-01-01

We present a multiwavelength study of three chromospherically active stars, namely FR Cnc (= BD +16 degrees 1753), HD 95559 and LO Peg (=BD +22 degrees 4409), including newly obtained optical photometry, (for FR Cnc) low-resolution optical spectroscopy, as well as archival IR and X-ray observations. The BVR photometry carried out during the years 2001 - 2004 has found significant photometric variability to be present in all three stars. For FR Cnc, a photometric period 0.826685 +/- 0.000034 d has been established. The strong variation in the phase and amplitude of the FR Cnc light curves when folded on this period implies the presence of evolving and migrating spots or spot groups on its surface. Two independent spots with migration periods of 0.97 and 0.93 years respectively are inferred. The photometry of HD 95559 suggests the formation of a spot (group) during the interval of our observations. We infer the existence of two independent spots or groups in the photosphere of LO Peg, one of which has a migration period of 1.12 years. The optical spectroscopy of FR Cnc carried out during 2002-2003, reveals the presence of strong and variable Ca I1 H and K, H(sub beta) and H(sub alpha) emission features indicative of high level of chromospheric activity. The value of 5.3 for the ratio of the excess emission in H(sub alpha) to H(sub beta), EH(sub alpha)/EH(sub beta), suggests that the chromospheric emission may arise from an extended off-limb region. We have searched for the presence of color excesses in the near-IR JHK bands of these stars using 2MASS data, but none of them appear to have any significant color excess. We have also analyzed archival X-ray observations of HD 95559 and LO Peg carried out by with the ROSAT observatory. The best fit models to their X-ray spectra imply the presence of two coronal plasma components of differing temperatures and with sub-solar metal abundances. The inferred emission measures and temperatures of these systems are similar to those found for other active dwarf stars. The kinematics of FR Cnc suggest that it is a very young (35 - 55 Myrs) main-sequence star and a possible member of the IC 2391 supercluster. LO Peg also has young disk-type kinematics and has been previously suggested to be a member of the 100 Mys old Local Association (Pleiades Moving Group). The kinematics of HD 95559 indicate it is a possible member of the 600 Myrs old Hyades supercluster.

Applying representational state transfer (REST) architecture to archetype-based electronic health record systems

PubMed Central

2013-01-01

Background The openEHR project and the closely related ISO 13606 standard have defined structures supporting the content of Electronic Health Records (EHRs). However, there is not yet any finalized openEHR specification of a service interface to aid application developers in creating, accessing, and storing the EHR content. The aim of this paper is to explore how the Representational State Transfer (REST) architectural style can be used as a basis for a platform-independent, HTTP-based openEHR service interface. Associated benefits and tradeoffs of such a design are also explored. Results The main contribution is the formalization of the openEHR storage, retrieval, and version-handling semantics and related services into an implementable HTTP-based service interface. The modular design makes it possible to prototype, test, replicate, distribute, cache, and load-balance the system using ordinary web technology. Other contributions are approaches to query and retrieval of the EHR content that takes caching, logging, and distribution into account. Triggering on EHR change events is also explored. A final contribution is an open source openEHR implementation using the above-mentioned approaches to create LiU EEE, an educational EHR environment intended to help newcomers and developers experiment with and learn about the archetype-based EHR approach and enable rapid prototyping. Conclusions Using REST addressed many architectural concerns in a successful way, but an additional messaging component was needed to address some architectural aspects. Many of our approaches are likely of value to other archetype-based EHR implementations and may contribute to associated service model specifications. PMID:23656624

Applying representational state transfer (REST) architecture to archetype-based electronic health record systems.

PubMed

Sundvall, Erik; Nyström, Mikael; Karlsson, Daniel; Eneling, Martin; Chen, Rong; Örman, Håkan

2013-05-09

The openEHR project and the closely related ISO 13606 standard have defined structures supporting the content of Electronic Health Records (EHRs). However, there is not yet any finalized openEHR specification of a service interface to aid application developers in creating, accessing, and storing the EHR content.The aim of this paper is to explore how the Representational State Transfer (REST) architectural style can be used as a basis for a platform-independent, HTTP-based openEHR service interface. Associated benefits and tradeoffs of such a design are also explored. The main contribution is the formalization of the openEHR storage, retrieval, and version-handling semantics and related services into an implementable HTTP-based service interface. The modular design makes it possible to prototype, test, replicate, distribute, cache, and load-balance the system using ordinary web technology. Other contributions are approaches to query and retrieval of the EHR content that takes caching, logging, and distribution into account. Triggering on EHR change events is also explored.A final contribution is an open source openEHR implementation using the above-mentioned approaches to create LiU EEE, an educational EHR environment intended to help newcomers and developers experiment with and learn about the archetype-based EHR approach and enable rapid prototyping. Using REST addressed many architectural concerns in a successful way, but an additional messaging component was needed to address some architectural aspects. Many of our approaches are likely of value to other archetype-based EHR implementations and may contribute to associated service model specifications.

The architecture of a modern military health information system.

PubMed

Mukherji, Raj J; Egyhazy, Csaba J

2004-06-01

This article describes a melding of a government-sponsored architecture for complex systems with open systems engineering architecture developed by the Institute for Electrical and Electronics Engineers (IEEE). Our experience in using these two architectures in building a complex healthcare system is described in this paper. The work described shows that it is possible to combine these two architectural frameworks in describing the systems, operational, and technical views of a complex automation system. The advantage in combining the two architectural frameworks lies in the simplicity of implementation and ease of understanding of automation system architectural elements by medical professionals.

Architectural Analysis of Dynamically Reconfigurable Systems

NASA Technical Reports Server (NTRS)

Lindvall, Mikael; Godfrey, Sally; Ackermann, Chris; Ray, Arnab; Yonkwa, Lyly

2010-01-01

oTpics include: the problem (increased flexibility of architectural styles decrease analyzability, behavior emerges and varies depending on the configuration, does the resulting system run according to the intended design, and architectural decisions can impede or facilitate testing); top down approach to architecture analysis, detection of defects and deviations, and architecture and its testability; currently targeted projects GMSEC and CFS; analyzing software architectures; analyzing runtime events; actual architecture recognition; GMPUB in Dynamic SAVE; sample output from new approach; taking message timing delays into account; CFS examples of architecture and testability; some recommendations for improved testablity; and CFS examples of abstract interfaces and testability; CFS example of opening some internal details.

Parallel protein secondary structure prediction based on neural networks.

PubMed

Zhong, Wei; Altun, Gulsah; Tian, Xinmin; Harrison, Robert; Tai, Phang C; Pan, Yi

2004-01-01

Protein secondary structure prediction has a fundamental influence on today's bioinformatics research. In this work, binary and tertiary classifiers of protein secondary structure prediction are implemented on Denoeux belief neural network (DBNN) architecture. Hydrophobicity matrix, orthogonal matrix, BLOSUM62 and PSSM (position specific scoring matrix) are experimented separately as the encoding schemes for DBNN. The experimental results contribute to the design of new encoding schemes. New binary classifier for Helix versus not Helix ( approximately H) for DBNN produces prediction accuracy of 87% when PSSM is used for the input profile. The performance of DBNN binary classifier is comparable to other best prediction methods. The good test results for binary classifiers open a new approach for protein structure prediction with neural networks. Due to the time consuming task of training the neural networks, Pthread and OpenMP are employed to parallelize DBNN in the hyperthreading enabled Intel architecture. Speedup for 16 Pthreads is 4.9 and speedup for 16 OpenMP threads is 4 in the 4 processors shared memory architecture. Both speedup performance of OpenMP and Pthread is superior to that of other research. With the new parallel training algorithm, thousands of amino acids can be processed in reasonable amount of time. Our research also shows that hyperthreading technology for Intel architecture is efficient for parallel biological algorithms.

On the Performance of an Algebraic MultigridSolver on Multicore Clusters

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

Baker, A H; Schulz, M; Yang, U M

2010-04-29

Algebraic multigrid (AMG) solvers have proven to be extremely efficient on distributed-memory architectures. However, when executed on modern multicore cluster architectures, we face new challenges that can significantly harm AMG's performance. We discuss our experiences on such an architecture and present a set of techniques that help users to overcome the associated problems, including thread and process pinning and correct memory associations. We have implemented most of the techniques in a MultiCore SUPport library (MCSup), which helps to map OpenMP applications to multicore machines. We present results using both an MPI-only and a hybrid MPI/OpenMP model.

Opening up Architectures of Software-Intensive Systems: A Functional Decomposition to Support System Comprehension

DTIC Science & Technology

2007-10-01

Architecture ................................................................................ 14 Figure 2. Eclipse Java Model...16 Figure 3. Eclipse Java Model at the Source Code Level...24 Figure 9. Java Source Code

Sensor Open System Architecture (SOSA) evolution for collaborative standards development

NASA Astrophysics Data System (ADS)

Collier, Charles Patrick; Lipkin, Ilya; Davidson, Steven A.; Baldwin, Rusty; Orlovsky, Michael C.; Ibrahim, Tim

2017-04-01

The Sensor Open System Architecture (SOSA) is a C4ISR-focused technical and economic collaborative effort between the Air Force, Navy, Army, the Department of Defense (DoD), Industry, and other Governmental agencies to develop (and incorporate) a technical Open Systems Architecture standard in order to maximize C4ISR sub-system, system, and platform affordability, re-configurability, and hardware/software/firmware re-use. The SOSA effort will effectively create an operational and technical framework for the integration of disparate payloads into C4ISR systems; with a focus on the development of a modular decomposition (defining functions and behaviors) and associated key interfaces (physical and logical) for common multi-purpose architecture for radar, EO/IR, SIGINT, EW, and Communications. SOSA addresses hardware, software, and mechanical/electrical interfaces. The modular decomposition will produce a set of re-useable components, interfaces, and sub-systems that engender reusable capabilities. This, in effect, creates a realistic and affordable ecosystem enabling mission effectiveness through systematic re-use of all available re-composed hardware, software, and electrical/mechanical base components and interfaces. To this end, SOSA will leverage existing standards as much as possible and evolve the SOSA architecture through modification, reuse, and enhancements to achieve C4ISR goals. This paper will present accomplishments over the first year of SOSA initiative.

Challenges in the Development and Evolution of Secure Open Architecture Command and Control Systems (Briefing Charts)

DTIC Science & Technology

2013-06-01

widgets for an OA system Design-time architecture: Browser, email, widget, DB, OS Go ogle Instance architecture: Chrome, Gmail, Google...provides functionally similar components or applications compatible with an OA system design Firefox Browser, WP, calendar Opera Instance...architecture: Firefox , AbiWord, Evolution, Fedora GPL Ab1Word Google Docs Instance ardlitecture: Fire fox, OR Google cal., Google Docs, Fedora

Homology of the cranial vault in birds: new insights based on embryonic fate-mapping and character analysis

NASA Astrophysics Data System (ADS)

Maddin, Hillary C.; Piekarski, Nadine; Sefton, Elizabeth M.; Hanken, James

2016-08-01

Bones of the cranial vault appear to be highly conserved among tetrapod vertebrates. Moreover, bones identified with the same name are assumed to be evolutionarily homologous. However, recent developmental studies reveal a key difference in the embryonic origin of cranial vault bones between representatives of two amniote lineages, mammals and birds, thereby challenging this view. In the mouse, the frontal is derived from cranial neural crest (CNC) but the parietal is derived from mesoderm, placing the CNC-mesoderm boundary at the suture between these bones. In the chicken, this boundary is located within the frontal. This difference and related data have led several recent authors to suggest that bones of the avian cranial vault are misidentified and should be renamed. To elucidate this apparent conflict, we fate-mapped CNC and mesoderm in axolotl to reveal the contributions of these two embryonic cell populations to the cranial vault in a urodele amphibian. The CNC-mesoderm boundary in axolotl is located between the frontal and parietal bones, as in the mouse but unlike the chicken. If, however, the avian frontal is regarded instead as a fused frontal and parietal (i.e. frontoparietal) and the parietal as a postparietal, then the cranial vault of birds becomes developmentally and topologically congruent with those of urodeles and mammals. This alternative hypothesis of cranial vault homology is also phylogenetically consistent with data from the tetrapod fossil record, where frontal, parietal and postparietal bones are present in stem lineages of all extant taxa, including birds. It further implies that a postparietal may be present in most non-avian archosaurs, but fused to the parietal or supraoccipital as in many extant mammals.

Light Curves Analysis of Deeply Eclipsed Dwarf Nova GY Cnc

NASA Astrophysics Data System (ADS)

Voloshina, I.; Khruzina, T.

2017-03-01

The results of photometric observations of the dwarf nova GY Cnc in the Rc filter in 2013-2016 are presented, including observations during its outburst in April 2014. The orbital ephemerides of the system have been determined more accurately using these numerous data. The orbital period has not significantly changed during the ˜ 30000 orbital cycles since the earlier observations; no systematic variations of O-C were found out. The fluctuations within the limits 0.004d on a timescale of 1500-2000 Porb were detected. A combined model is used to solve for the parameters of GY Cnc for both states of the system. The donor star temperature, T2˜ 3667 K (Sp M0.2 V) varies between 3440 and 3900 K (Sp K8.8-M1.7 V). The semi-major axis of the disk is a˜0.22a0, on average. In quiet state, a varies within ˜ 40%. The disk has a considerable eccentricity (e˜0.2-0.3) for the small a values, a≤0.2a0. With increasing a the disk shape becomes more circular (e<0.1). The GY Cnc outburst is due to a sharp growth of the disk luminosity because of a diminution of αg parameter (which is related to the viscosity of the disk material) up to 0.1-0.2, and the temperature of the disk interiors increasing twofold to Tin ˜ 95000 K. These changes were probably due to infall of matter onto the surface of white dwarf as the outburst developed. For all accretion disk parameters in a quiet state considerable variations about their mean values are typical.

Ribosome Biogenesis Modulates Ty1 Copy Number Control in Saccharomyces cerevisiae

PubMed Central

Ahn, Hyo Won; Tucker, Jessica M.; Arribere, Joshua A.; Garfinkel, David J.

2017-01-01

Transposons can impact the host genome by altering gene expression and participating in chromosome rearrangements. Therefore, organisms evolved different ways to minimize the level of transposition. In Saccharomyces cerevisiae and its close relative S. paradoxus, Ty1 copy number control (CNC) is mediated by the self-encoded restriction factor p22, which is derived from the GAG capsid gene and inhibits virus-like particle (VLP) assembly and function. Based on secondary screens of Ty1 cofactors, we identified LOC1, a RNA localization/ribosome biogenesis gene that affects Ty1 mobility predominantly in strains harboring Ty1 elements. Ribosomal protein mutants rps0bΔ and rpl7aΔ displayed similar CNC-specific phenotypes as loc1Δ, suggesting that ribosome biogenesis is critical for CNC. The level of Ty1 mRNA and Ty1 internal (Ty1i) transcripts encoding p22 was altered in these mutants, and displayed a trend where the level of Ty1i RNA increased relative to full-length Ty1 mRNA. The level of p22 increased in these mutants, and the half-life of p22 also increased in a loc1Δ mutant. Transcriptomic analyses revealed small changes in the level of Ty1 transcripts or efficiency of translation initiation in a loc1Δ mutant. Importantly, a loc1Δ mutant had defects in assembly of Gag complexes and packaging Ty1 RNA. Our results indicate that defective ribosome biogenesis enhances CNC by increasing the level of p22, and raise the possibility for versatile links between VLP assembly, its cytoplasmic environment, and a novel stress response. PMID:29046400

RADIAL VELOCITY PLANETS DE-ALIASED: A NEW, SHORT PERIOD FOR SUPER-EARTH 55 Cnc e

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

Dawson, Rebekah I.; Fabrycky, Daniel C., E-mail: rdawson@cfa.harvard.ed, E-mail: daniel.fabrycky@gmail.co

2010-10-10

Radial velocity measurements of stellar reflex motion have revealed many extrasolar planets, but gaps in the observations produce aliases, spurious frequencies that are frequently confused with the planets' orbital frequencies. In the case of Gl 581 d, the distinction between an alias and the true frequency was the distinction between a frozen, dead planet and a planet possibly hospitable to life. To improve the characterization of planetary systems, we describe how aliases originate and present a new approach for distinguishing between orbital frequencies and their aliases. Our approach harnesses features in the spectral window function to compare the amplitude andmore » phase of predicted aliases with peaks present in the data. We apply it to confirm prior alias distinctions for the planets GJ 876 d and HD 75898 b. We find that the true periods of Gl 581 d and HD 73526 b/c remain ambiguous. We revise the periods of HD 156668 b and 55 Cnc e, which were afflicted by daily aliases. For HD 156668 b, the correct period is 1.2699 days and the minimum mass is (3.1 {+-} 0.4) M{sub +}. For 55 Cnc e, the correct period is 0.7365 days-the shortest of any known planet-and the minimum mass is (8.3 {+-} 0.3) M{sub +}. This revision produces a significantly improved five-planet Keplerian fit for 55 Cnc, and a self-consistent dynamical fit describes the data just as well. As radial velocity techniques push to ever-smaller planets, often found in systems of multiple planets, distinguishing true periods from aliases will become increasingly important.« less

Quantification of uncertainty in machining operations for on-machine acceptance.

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

Claudet, Andre A.; Tran, Hy D.; Su, Jiann-Chemg

2008-09-01

Manufactured parts are designed with acceptance tolerances, i.e. deviations from ideal design conditions, due to unavoidable errors in the manufacturing process. It is necessary to measure and evaluate the manufactured part, compared to the nominal design, to determine whether the part meets design specifications. The scope of this research project is dimensional acceptance of machined parts; specifically, parts machined using numerically controlled (NC, or also CNC for Computer Numerically Controlled) machines. In the design/build/accept cycle, the designer will specify both a nominal value, and an acceptable tolerance. As part of the typical design/build/accept business practice, it is required to verifymore » that the part did meet acceptable values prior to acceptance. Manufacturing cost must include not only raw materials and added labor, but also the cost of ensuring conformance to specifications. Ensuring conformance is a substantial portion of the cost of manufacturing. In this project, the costs of measurements were approximately 50% of the cost of the machined part. In production, cost of measurement would be smaller, but still a substantial proportion of manufacturing cost. The results of this research project will point to a science-based approach to reducing the cost of ensuring conformance to specifications. The approach that we take is to determine, a priori, how well a CNC machine can manufacture a particular geometry from stock. Based on the knowledge of the manufacturing process, we are then able to decide features which need further measurements from features which can be accepted 'as is' from the CNC. By calibration of the machine tool, and establishing a machining accuracy ratio, we can validate the ability of CNC to fabricate to a particular level of tolerance. This will eliminate the costs of checking for conformance for relatively large tolerances.« less

What Multilevel Parallel Programs do when you are not Watching: A Performance Analysis Case Study Comparing MPI/OpenMP, MLP, and Nested OpenMP

NASA Technical Reports Server (NTRS)

Jost, Gabriele; Labarta, Jesus; Gimenez, Judit

2004-01-01

With the current trend in parallel computer architectures towards clusters of shared memory symmetric multi-processors, parallel programming techniques have evolved that support parallelism beyond a single level. When comparing the performance of applications based on different programming paradigms, it is important to differentiate between the influence of the programming model itself and other factors, such as implementation specific behavior of the operating system (OS) or architectural issues. Rewriting-a large scientific application in order to employ a new programming paradigms is usually a time consuming and error prone task. Before embarking on such an endeavor it is important to determine that there is really a gain that would not be possible with the current implementation. A detailed performance analysis is crucial to clarify these issues. The multilevel programming paradigms considered in this study are hybrid MPI/OpenMP, MLP, and nested OpenMP. The hybrid MPI/OpenMP approach is based on using MPI [7] for the coarse grained parallelization and OpenMP [9] for fine grained loop level parallelism. The MPI programming paradigm assumes a private address space for each process. Data is transferred by explicitly exchanging messages via calls to the MPI library. This model was originally designed for distributed memory architectures but is also suitable for shared memory systems. The second paradigm under consideration is MLP which was developed by Taft. The approach is similar to MPi/OpenMP, using a mix of coarse grain process level parallelization and loop level OpenMP parallelization. As it is the case with MPI, a private address space is assumed for each process. The MLP approach was developed for ccNUMA architectures and explicitly takes advantage of the availability of shared memory. A shared memory arena which is accessible by all processes is required. Communication is done by reading from and writing to the shared memory.

Software Productivity of Field Experiments Using the Mobile Agents Open Architecture with Workflow Interoperability

NASA Technical Reports Server (NTRS)

Clancey, William J.; Lowry, Michael R.; Nado, Robert Allen; Sierhuis, Maarten

2011-01-01

We analyzed a series of ten systematically developed surface exploration systems that integrated a variety of hardware and software components. Design, development, and testing data suggest that incremental buildup of an exploration system for long-duration capabilities is facilitated by an open architecture with appropriate-level APIs, specifically designed to facilitate integration of new components. This improves software productivity by reducing changes required for reconfiguring an existing system.

ECHO Services: Foundational Middleware for a Science Cyberinfrastructure

NASA Technical Reports Server (NTRS)

Burnett, Michael

2005-01-01

This viewgraph presentation describes ECHO, an interoperability middleware solution. It uses open, XML-based APIs, and supports net-centric architectures and solutions. ECHO has a set of interoperable registries for both data (metadata) and services, and provides user accounts and a common infrastructure for the registries. It is built upon a layered architecture with extensible infrastructure for supporting community unique protocols. It has been operational since November, 2002 and it available as open source.

Space Generic Open Avionics Architecture (SGOAA) standard specification

NASA Technical Reports Server (NTRS)

Wray, Richard B.; Stovall, John R.

1994-01-01

This standard establishes the Space Generic Open Avionics Architecture (SGOAA). The SGOAA includes a generic functional model, processing structural model, and an architecture interface model. This standard defines the requirements for applying these models to the development of spacecraft core avionics systems. The purpose of this standard is to provide an umbrella set of requirements for applying the generic architecture models to the design of a specific avionics hardware/software processing system. This standard defines a generic set of system interface points to facilitate identification of critical services and interfaces. It establishes the requirement for applying appropriate low level detailed implementation standards to those interfaces points. The generic core avionics functions and processing structural models provided herein are robustly tailorable to specific system applications and provide a platform upon which the interface model is to be applied.

Modular open RF architecture: extending VICTORY to RF systems

NASA Astrophysics Data System (ADS)

Melber, Adam; Dirner, Jason; Johnson, Michael

2015-05-01

Radio frequency products spanning multiple functions have become increasingly critical to the warfighter. Military use of the electromagnetic spectrum now includes communications, electronic warfare (EW), intelligence, and mission command systems. Due to the urgent needs of counterinsurgency operations, various quick reaction capabilities (QRCs) have been fielded to enhance warfighter capability. Although these QRCs were highly successfully in their respective missions, they were designed independently resulting in significant challenges when integrated on a common platform. This paper discusses how the Modular Open RF Architecture (MORA) addresses these challenges by defining an open architecture for multifunction missions that decomposes monolithic radio systems into high-level components with welldefined functions and interfaces. The functional decomposition maximizes hardware sharing while minimizing added complexity and cost due to modularization. MORA achieves significant size, weight and power (SWaP) savings by allowing hardware such as power amplifiers and antennas to be shared across systems. By separating signal conditioning from the processing that implements the actual radio application, MORA exposes previously inaccessible architecture points, providing system integrators with the flexibility to insert third-party capabilities to address technical challenges and emerging requirements. MORA leverages the Vehicular Integration for Command, Control, Communication, Computers, Intelligence, Surveillance, and Reconnaissance (C4ISR)/EW Interoperability (VICTORY) framework. This paper concludes by discussing how MORA, VICTORY and other standards such as OpenVPX are being leveraged by the U.S. Army Research, Development, and Engineering Command (RDECOM) Communications Electronics Research, Development, and Engineering Center (CERDEC) to define a converged architecture enabling rapid technology insertion, interoperability and reduced SWaP.

Defining and using open architecture levels

NASA Astrophysics Data System (ADS)

Cramer, M. A.; Morrison, A. W.; Cordes, B.; Stack, J. R.

2012-05-01

Open architecture (OA) within military systems enables delivery of increased warfighter capabilities in a shorter time at a reduced cost.i In fact in today's standards-aware environment, solutions are often proposed to the government that include OA as one of its basics design tenets. Yet the ability to measure and assess OA in an objective manner, particularly at the subsystem/component level within a system, remains an elusive proposition. Furthermore, it is increasingly apparent that the establishment of an innovation ecosystem of an open business model that leverages thirdparty development requires more than just technical modifications that promote openness. This paper proposes a framework to migrate not only towards technical openness, but also towards enabling and facilitating an open business model, driven by third party development, for military systems. This framework was developed originally for the U.S. Navy Littoral and Mine Warfare community; however, the principles and approach may be applied elsewhere within the Navy and Department of Defense.

Reliability Measure of a Clinical Test: Appreciation of Music in Cochlear Implantees (AMICI)

PubMed Central

Cheng, Min-Yu; Spitzer, Jaclyn B.; Shafiro, Valeriy; Sheft, Stanley; Mancuso, Dean

2014-01-01

Purpose The goals of this study were (1) to investigate the reliability of a clinical music perception test, Appreciation of Music in Cochlear Implantees (AMICI), and (2) examine associations between the perception of music and speech. AMICI was developed as a clinical instrument for assessing music perception in persons with cochlear implants (CIs). The test consists of four subtests: (1) music versus environmental noise discrimination, (2) musical instrument identification (closed-set), (3) musical style identification (closed-set), and (4) identification of musical pieces (open-set). To be clinically useful, it is crucial for AMICI to demonstrate high test-retest reliability, so that CI users can be assessed and retested after changes in maps or programming strategies. Research Design Thirteen CI subjects were tested with AMICI for the initial visit and retested again 10–14 days later. Two speech perception tests (consonant-nucleus-consonant [CNC] and Bamford-Kowal-Bench Speech-in-Noise [BKB-SIN]) were also administered. Data Analysis Test-retest reliability and equivalence of the test’s three forms were analyzed using paired t-tests and correlation coefficients, respectively. Correlation analysis was also conducted between results from the music and speech perception tests. Results Results showed no significant difference between test and retest (p > 0.05) with adequate power (0.9) as well as high correlations between the three forms (Forms A and B, r = 0.91; Forms A and C, r = 0.91; Forms B and C, r = 0.95). Correlation analysis showed high correlation between AMICI and BKB-SIN (r = −0.71), and moderate correlation between AMICI and CNC (r = 0.4). Conclusions The study showed AMICI is highly reliable for assessing musical perception in CI users. PMID:24384082

Structure of a PKA RIα Recurrent Acrodysostosis Mutant Explains Defective cAMP-Dependent Activation

DOE PAGES

Bruystens, Jessica G. H.; Wu, Jian; Fortezzo, Audrey; ...

2016-11-05

Most disease related mutations that impair PKA signaling are present within the regulatory PKA RI alpha-subunit (RIα). Although mutations in the PRKAR1A gene are linked to Carney complex disease (CNC) and more recently to acrodysostosis-1 (ACRDYS1), the two diseases show contrasting phenotypes. While CNC mutations cause increased PKA activity, ACRDYS1 mutations result in decreased PKA activity and cAMP resistant holoenzymes. Mapping the ACRDYS1 disease mutations reveals their localization to the second of two tandem cAMP binding domains (CNB-B) and here we characterize a recurrent deletion mutant where the last 14 residues are missing. The crystal structure of a monomeric formmore » of this mutant (RIα92-365) bound to the C subunit reveals the dysfunctional regions of the RIα-subunit. Beyond the missing residues, the entire capping motif is disordered (residues 357-379) and explains the disrupted cAMP binding. Moreover, the effects of the mutation extend far beyond the CNB-B domain and include the active site and N-lobe of the C-subunit, which is in a partially open conformation with the C-tail disordered. A key residue that contributes to this crosstalk, D267, is altered in our structure and we confirmed its functional importance by mutagenesis. In particular, the D267 interaction with Arg241, a residue shown earlier to be important for allosteric regulation, is disrupted thereby strengthening the interaction of D267 with the C-subunit residue Arg194 at the R:C interface. Here, we see here how the switch between active (cAMP-bound) and inactive (holoenzyme) conformations is perturbed and how the dynamically controlled crosstalk between the helical domains of the two CNB-domains is necessary for functional regulation of PKA activity.« less

Elemental abundance analyses with Complejo Astronomico. EL Leoncito REOSC echelle spectrograms. I. κ Cancri, HR 7245, and ξ Octantis

NASA Astrophysics Data System (ADS)

Pintado, O. I.; Adelman, S. J.

1996-08-01

Elemental abundances are derived for three sharp-lined stars κ Cnc, HR 7245, and ξ Oct using REOSC echelle spectrograms obtained at CASLEO. Comparisons are made with published equivalent widths. The derived abundances for κ Cnc and ξ Oct are slightly larger than those obtained with other high dispersion spectrographs. HR 7245 exhibits a pattern of abundance anomalies similar to other Mercury-Manganese stars. The spectra of the two HgMn stars in the λλ4640-5100 region exhibit an interesting and useful variety of lines which can be used to supplement analyses of the photographic region.

Iron-platinum-coated carbon nanocone probes on tipless cantilevers for high resolution magnetic force imaging.

PubMed

Chen, I-Chen; Chen, Li-Han; Gapin, Andrew; Jin, Sungho; Yuan, Lu; Liou, Sy-Hwang

2008-02-20

High coercivity iron-platinum-coated carbon nanocones (CNCs) have been fabricated for magnetic force microscopy (MFM) by direct-current plasma-enhanced chemical vapor deposition growth of nanocones on tipless cantilevers followed by sputtering and annealing of the FePt film. The FePt-coated CNC probe has many localized magnetic stray fields due to the high-aspect-ratio geometry and small radius of the tip. The MFM imaging on magnetic recording media was performed using CNC probes and compared with the imaging by FePt-coated silicon probes. An image with 20 nm lateral resolution has been demonstrated.

Mechatronics Education: From Paper Design to Product Prototype Using LEGO NXT Parts

NASA Astrophysics Data System (ADS)

Lofaro, Daniel M.; Le, Tony Truong Giang; Oh, Paul

The industrial design cycle starts with design then simulation, prototyping, and testing. When the tests do not match the design requirements the design process is started over again. It is important for students to experience this process before they leave their academic institution. The high cost of the prototype phase, due to CNC/Rapid Prototype machine costs, makes hands on study of this process expensive for students and the academic institutions. This document shows that the commercially available LEGO NXT Robot kit is a viable low cost surrogate to the expensive industrial CNC/Rapid Prototype portion of the industrial design cycle.

FPGA-based fused smart-sensor for tool-wear area quantitative estimation in CNC machine inserts.

PubMed

Trejo-Hernandez, Miguel; Osornio-Rios, Roque Alfredo; de Jesus Romero-Troncoso, Rene; Rodriguez-Donate, Carlos; Dominguez-Gonzalez, Aurelio; Herrera-Ruiz, Gilberto

2010-01-01

Manufacturing processes are of great relevance nowadays, when there is a constant claim for better productivity with high quality at low cost. The contribution of this work is the development of a fused smart-sensor, based on FPGA to improve the online quantitative estimation of flank-wear area in CNC machine inserts from the information provided by two primary sensors: the monitoring current output of a servoamplifier, and a 3-axis accelerometer. Results from experimentation show that the fusion of both parameters makes it possible to obtain three times better accuracy when compared with the accuracy obtained from current and vibration signals, individually used.

The role of robotics in computer controlled polishing of large and small optics

NASA Astrophysics Data System (ADS)

Walker, David; Dunn, Christina; Yu, Guoyu; Bibby, Matt; Zheng, Xiao; Wu, Hsing Yu; Li, Hongyu; Lu, Chunlian

2015-08-01

Following formal acceptance by ESO of three 1.4m hexagonal off-axis prototype mirror segments, one circular segment, and certification of our optical test facility, we turn our attention to the challenge of segment mass-production. In this paper, we focus on the role of industrial robots, highlighting complementarity with Zeeko CNC polishing machines, and presenting results using robots to provide intermediate processing between CNC grinding and polishing. We also describe the marriage of robots and Zeeko machines to automate currently manual operations; steps towards our ultimate vision of fully autonomous manufacturing cells, with impact throughout the optical manufacturing community and beyond.

New developments in surface technology and prototyping

NASA Astrophysics Data System (ADS)

Himmer, Thomas; Beyer, Eckhard

2003-03-01

Novel lightweight applications in the automotive and aircraft industries require advanced materials and techniques for surface protection as well as direct and rapid manufacturing of the related components and tools. The manufacturing processes presented in this paper are based on multiple additive and subtractive technologies such as laser cutting, laser welding, direct laser metal deposition, laser/plasma hybrid spraying technique or CNC milling. The process chain is similar to layer-based Rapid Prototyping Techniques. In the first step, the 3D CAD geometry is sliced into layers by a specially developed software. These slices are cut by high speed laser cutting and then joined together. In this way laminated tools or parts are built. To improve surface quality and to increase wear resistance a CNC machining center is used. The system consists of a CNC milling machine, in which a 3 kW Nd:YAG laser, a coaxial powder nozzle and a digitizing system are integrated. Using a new laser/plasma hybrid spraying technique, coatings can be deposited onto parts for surface protection. The layers show a low porosity and high adhesion strength, the thickness is up to 0.3 mm, and the lower effort for preliminary surface preparation reduces time and costs of the whole process.

Bioinspired Cocatalysts Decorated WO3 Nanotube Toward Unparalleled Hydrogen Sulfide Chemiresistor.

PubMed

Kim, Dong-Ha; Jang, Ji-Soo; Koo, Won-Tae; Choi, Seon-Jin; Cho, Hee-Jin; Kim, Min-Hyeok; Kim, Sang-Joon; Kim, Il-Doo

2018-06-22

Herein, we incorporated dual biotemplates, i.e., cellulose nanocrystals (CNC) and apoferritin, into electrospinning solution to achieve three distinct benefits, i.e., (i) facile synthesis of a WO 3 nanotube by utilizing the self-agglomerating nature of CNC in the core of as-spun nanofibers, (ii) effective sensitization by partial phase transition from WO 3 to Na 2 W 4 O 13 induced by interaction between sodium-doped CNC and WO 3 during calcination, and (iii) uniform functionalization with monodispersive apoferritin-derived Pt catalytic nanoparticles (2.22 ± 0.42 nm). Interestingly, the sensitization effect of Na 2 W 4 O 13 on WO 3 resulted in highly selective H 2 S sensing characteristics against seven different interfering molecules. Furthermore, synergistic effects with a bioinspired Pt catalyst induced a remarkably enhanced H 2 S response ( R air / R gas = 203.5), unparalleled selectivity ( R air / R gas < 1.3 for the interfering molecules), and rapid response (<10 s)/recovery (<30 s) time at 1 ppm of H 2 S under 95% relative humidity level. This work paves the way for a new class of cosensitization routes to overcome critical shortcomings of SMO-based chemical sensors, thus providing a potential platform for diagnosis of halitosis.

Towards completing the cyclopropenylidene cycle: rovibrational analysis of cyclic N3+, CNN, HCNN+, and CNC.

PubMed

Fortenberry, Ryan C; Lee, Timothy J; Huang, Xinchuan

2017-08-30

The simple aromatic hydrocarbon, cyclopropenylidene (c-C 3 H 2 ), is a known, naturally-occurring molecule. The question remains as to whether its isoelectronic, cyclic, fellow aromatics of c-N 3 + , c-CNN, HCNN + , and c-CNC - are as well. Each of these are exciting objects for observation of Titan, and the rotational constants and vibrational frequencies produced here will allow for remote sensing of Titan's atmosphere or other astrophysical or terrestrial sources. None of these four aromatic species are vibrationally strong absorbers/emitters, but the two ions, HCNN + and c-CNC - , have dipole moments of greater than 3 D and 1 D, respectively, making them good targets for rotational spectroscopic observation. Each of these molecules is shown here to exhibit its own, unique vibrational properties, but the general trends put the vibrational behavior for corresponding fundamental modes within close ranges of one another, even producing nearly the same heavy atom, symmetric stretching frequencies for HCNN + and c-C 3 H 2 at 1600 cm -1 . The c-N 3 + cation is confirmed to be fairly unstable and has almost no intensity in its ν 2 fundamental. Hence, it will likely remain difficult to characterize experimentally.

Pincer-CNC mononuclear, dinuclear and heterodinuclear Au(III) and Pt(II) complexes supported by mono- and poly-N-heterocyclic carbenes: synthesis and photophysical properties.

PubMed

Gonell, S; Poyatos, M; Peris, E

2016-04-07

A family of cyclometallated Au(iii) and Pt(ii) complexes containing a CNC-pincer ligand (CNC = 2,6-diphenylpyridine) supported by pyrene-based mono- or bis-NHC ligands have been synthesized and characterized, together with the preparation of a Pt-Au hetero-dimetallic complex based on a Y-shaped tris-NHC ligand. The photophysical properties of all the new species and of two related Ru(ii)-arene complexes were studied and compared. Whereas the pyrene-based complexes only exhibit emission in solution, those containing the Y-shaped tris-NHC ligand are only luminescent when dispersed in poly(methyl methacrylate) (PMMA). In particular, the pyrene-based complexes were found to be emissive in the range of 373-440 nm, with quantum yields ranging from 3.1 to 6.3%, and their emission spectra were found to be almost superimposable, pointing to the fluorescent pyrene-centered nature of the emission. This observation suggests that the emission properties of the pyrene fragment may be combined with some of the numerous applications of NHCs as supporting ligands allowing, for instance, the design of biological luminescent agents.

Metal Nanoparticles Embedded in Cellulose Nanocrystal Based Films: Material Properties and Post-use Analysis.

PubMed

Lizundia, Erlantz; Goikuria, Uribarri; Vilas, José Luis; Cristofaro, Francesco; Bruni, Giovanna; Fortunati, Elena; Armentano, Ilaria; Visai, Livia; Torre, Luigi

2018-04-25

The dispersion of nanoparticles having different size-, shape-, and composition-dependent properties is an exciting approach to design and synthesize multifunctional materials and devices. This work shows a detailed investigation of the preparation and properties of free-standing nanocomposite films based on cellulose nanocrystals (CNC) loaded with three different types of metal nanoparticles. CNC-based nanocomposites having zinc oxide (ZnO), titanium dioxide (TiO 2 ), and silver oxide (Ag 2 O) have been obtained through evaporation-induced self-assembly (EISA) in acqueous solution. Morphological and optical characteristics, chemical properties, wettability, and antimicrobial assays of the produced films were conducted. Furthermore, disintegrability in composting condition of CNC based nanocomposites was here investigated for the first time. The morphological observations revealed the formation of a chiral nematic structure with uniformly distributed nanoparticles. The bionanocomposite films based on the metal nanoparticles had effective antimicrobial activity, killing both Escherichia coli RB ( E. coli RB) and Staphylococcus aureus 8325-4 ( S. aureus 8325-4). The simplicity method of film preparation, the large quantity of cellulose in the world, and the free-standing nature of the nanocomposite films offer highly advantageous characteristics that can for the new development of multifunctional materials.

The Neural-fuzzy Thermal Error Compensation Controller on CNC Machining Center

NASA Astrophysics Data System (ADS)

Tseng, Pai-Chung; Chen, Shen-Len

The geometric errors and structural thermal deformation are factors that influence the machining accuracy of Computer Numerical Control (CNC) machining center. Therefore, researchers pay attention to thermal error compensation technologies on CNC machine tools. Some real-time error compensation techniques have been successfully demonstrated in both laboratories and industrial sites. The compensation results still need to be enhanced. In this research, the neural-fuzzy theory has been conducted to derive a thermal prediction model. An IC-type thermometer has been used to detect the heat sources temperature variation. The thermal drifts are online measured by a touch-triggered probe with a standard bar. A thermal prediction model is then derived by neural-fuzzy theory based on the temperature variation and the thermal drifts. A Graphic User Interface (GUI) system is also built to conduct the user friendly operation interface with Insprise C++ Builder. The experimental results show that the thermal prediction model developed by neural-fuzzy theory methodology can improve machining accuracy from 80µm to 3µm. Comparison with the multi-variable linear regression analysis the compensation accuracy is increased from ±10µm to ±3µm.

Spin-orbit coupling for tidally evolving super-Earths

NASA Astrophysics Data System (ADS)

Rodríguez, A.; Callegari, N.; Michtchenko, T. A.; Hussmann, H.

2012-12-01

We investigate the spin behaviour of close-in rocky planets and the implications for their orbital evolution. Considering that the planet rotation evolves under simultaneous actions of the torque due to the equatorial deformation and the tidal torque, both raised by the central star, we analyse the possibility of temporary captures in spin-orbit resonances. The results of the numerical simulations of the exact equations of motions indicate that, whenever the planet rotation is trapped in a resonant motion, the orbital decay and the eccentricity damping are faster than the ones in which the rotation follows the so-called pseudo-synchronization. Analytical results obtained through the averaged equations of the spin-orbit problem show a good agreement with the numerical simulations. We apply the analysis to the cases of the recently discovered hot super-Earths Kepler-10 b, GJ 3634 b and 55 Cnc e. The simulated dynamical history of these systems indicates the possibility of capture in several spin-orbit resonances; particularly, GJ 3634 b and 55 Cnc e can currently evolve under a non-synchronous resonant motion for suitable values of the parameters. Moreover, 55 Cnc e may avoid a chaotic rotation behaviour by evolving towards synchronization through successive temporary resonant trappings.

VizieR Online Data Catalog: HARPS and HARPS-N 55 Cnc radial velocities (Lopez-Morales+, 2014)

NASA Astrophysics Data System (ADS)

Lopez-Morales, M.; Triaud, A. H. M. J.; Rodler, F.; Dumusque, X.; Buchhave, L. A.; Harutyunyan, A.; Hoyer, S.; Alonso, R.; Gillon, M.; Kaib, N. A.; Latham, D. W.; Lovis, C.; Pepe, F.; Queloz, D.; Raymond, S. N.; Segransan, D.; Waldmann, I. P.; Udry, S.

2017-04-01

Shortly after the detection of 55 Cnc e's transit was announced, we requested four spectroscopic time series on HARPS (Prog. ID 288.C-5010; PI: Triaud) as Director Discretionary Time. HARPS is installed on the 3.6 m telescope at the European Southern Observatory on La Silla, Chile (Mayor et al. 2003Msngr.114...20M). The position of 55 Cnc in the sky-RA(J2000)=08:52:35.81, DE(J2000)=+28:10:50.95-is low as seen from La Silla. The target remains at a zenith distance of z<2 for only ~2.5 hr per night, with a transit duration of about 1.5 hr having to fit within this tight window. This constraint on the airmass, essential to obtain precise radial velocities (RVs), is set by the instrumental atmospheric dispersion corrector. We used the ephemeris by Gillon et al. (2012, J/A+A/539/A28), then at an advanced stage of preparation, to schedule our observations. In total, we gathered 179 spectra on the nights starting on 2012 January 27, 2012 February 13, 2012 February 27, and 2012 March 15 UT. (1 data file).

Influences of internal resistance and specific surface area of electrode materials on characteristics of electric double layer capacitors

NASA Astrophysics Data System (ADS)

Suda, Yoshiyuki; Mizutani, Akitaka; Harigai, Toru; Takikawa, Hirofumi; Ue, Hitoshi; Umeda, Yoshito

2017-01-01

We fabricated electric double layer capacitors (EDLCs) using particulate and fibrous types of carbon nanomaterials with a wide range of specific surface areas and resistivity as an active material. The carbon nanomaterials used in this study are carbon nanoballoons (CNBs), onion-like carbon (OLC), and carbon nanocoils (CNCs). A commercially used activated carbon (AC) combined with a conductive agent was used as a comparison. We compared the EDLC performance using cyclic voltammetry (CV), galvanostatic charge/discharge testing, and electrochemical impedance spectroscopy (EIS). OLC showed a poor EDLC performance, although it has the lowest resistivity among the carbon nanomaterials. CNB, which has a 1/16 lower specific surface area than AC but higher specific surface area than CNC and OLC, had a higher specific capacitance than CNC and OLC. Moreover, at current densities of 1.5 Ag-1 and larger, the specific capacitance of the EDLC using CNB was almost the same as that using AC. Electrochemical impedance spectroscopy of the EDLCs revealed that the CNB and CNC electrodes had a much lower internal resistance than the AC electrode, which correlated with a low capacitance maintenance factor as the current density increased.

Far-Ultraviolet Spectroscopy of Three Long-Period Novalike Variables

NASA Astrophysics Data System (ADS)

Bisol, Alexandra C.; Godon, Patrick; Sion, Edward M.

2012-02-01

We have selected three novalike variables at the long-period extreme of novalike orbital periods: V363 Aur, RZ Gru, and AC Cnc, all with IUE archival far-ultraviolet spectra. All are UX UMa-type novalike variables and all have Porb > 7 hr. V363 Aur is a bona fide SW Sex star, and AC Cnc is a probable one, while RZ Gru has not proven to be a member of the SW Sex subclass. We have carried out the first synthetic spectral analysis of far-ultraviolet spectra of the three systems using state-of-the-art models of both accretion disks and white dwarf photospheres. We find that the FUV spectral energy distribution of both V363 Aur and RZ Gru are in agreement with optically thick steady-state accretion disk models in which the luminous disk accounts for 100% of the FUV light. We present accretion rates and model-derived distances for V363 Aur and RZ Gru. For AC Cnc, we find that a hot accreting white dwarf accounts for ˜60% of the FUV light, with an accretion disk providing the rest. We compare our accretion rates and model-derived distances with estimates in the literature.

Increased functional properties and thermal stability of flexible cellulose nanocrystal/ZnO films.

PubMed

Lizundia, E; Urruchi, A; Vilas, J L; León, L M

2016-01-20

In this work we attempt to improve the functional properties and thermal stability of cellulose nanocrystal (CNC) films by means of eco-friendly materials and processes. Mechanically flexible films of closely packed CNCs with concentrations up to 5 wt.% of zinc oxide (ZnO) nanoparticles have been prepared by a simple, standard and environmentally friendly method using solely water. Results reveal that ultraviolet light is blocked by 98.5% at 1 wt.% ZnO while good transparency is maintained. A sharp hydrophobicity increase is observed with the addition of ZnO which would enhance the durability of films by decreasing the water diffusion through the material. The thermal degradation activation energy (E) presents an increase of 141%, denoting a high thermal stability of films, which would result beneficial for their potential application in the field of flexible electronics. Mechanical results demonstrate a high structural integrity of CNC/ZnO as a result of the occurring strong cellulosic inter- and intramolecular interactions within the closely packed CNC network. In overall, this work highlights the potential for environmentally friendly processing of sustainable nanostructured functional materials based on cellulose. Copyright © 2015 Elsevier Ltd. All rights reserved.

Polylogarithmic equilibrium treatment of molecular aggregation and critical concentrations.

PubMed

Michel, Denis; Ruelle, Philippe

2017-02-15

A full equilibrium treatment of molecular aggregation is presented for prototypes of 1D and 3D aggregates, with and without nucleation. By skipping complex kinetic parameters like aggregate size-dependent diffusion, the equilibrium treatment allows us to predict directly time-independent quantities such as critical concentrations. The relationships between the macroscopic equilibrium constants for different paths are first established by statistical corrections and so as to comply with the detailed balance constraints imposed by nucleation, and the composition of the mixture resulting from homogeneous aggregation is then analyzed using a polylogarithmic function. Several critical concentrations are distinguished: the residual monomer concentration at equilibrium (RMC) and the critical nucleation concentration (CNC), which is the threshold concentration of total subunits necessary for initiating aggregation. When increasing the concentration of total subunits, the RMC converges more strongly to its asymptotic value, the equilibrium constant of depolymerization, for 3D aggregates and in the case of nucleation. The CNC moderately depends on the number of subunits in the nucleus, but sharply increases with the difference between the equilibrium constants of polymerization and nucleation. As the RMC and CNC can be numerically but not analytically determined, ansatz equations connecting them to thermodynamic parameters are proposed.

An Architecture to Promote the Commercialization of Space Mission Command and Control

NASA Technical Reports Server (NTRS)

Jones, Michael K.

1996-01-01

This paper describes a command and control architecture that encompasses space mission operations centers, ground terminals, and spacecraft. This architecture is intended to promote the growth of a lucrative space mission operations command and control market through a set of open standards used by both gevernment and profit-making space mission operators.

Portable LQCD Monte Carlo code using OpenACC

NASA Astrophysics Data System (ADS)

Bonati, Claudio; Calore, Enrico; Coscetti, Simone; D'Elia, Massimo; Mesiti, Michele; Negro, Francesco; Fabio Schifano, Sebastiano; Silvi, Giorgio; Tripiccione, Raffaele

2018-03-01

Varying from multi-core CPU processors to many-core GPUs, the present scenario of HPC architectures is extremely heterogeneous. In this context, code portability is increasingly important for easy maintainability of applications; this is relevant in scientific computing where code changes are numerous and frequent. In this talk we present the design and optimization of a state-of-the-art production level LQCD Monte Carlo application, using the OpenACC directives model. OpenACC aims to abstract parallel programming to a descriptive level, where programmers do not need to specify the mapping of the code on the target machine. We describe the OpenACC implementation and show that the same code is able to target different architectures, including state-of-the-art CPUs and GPUs.

Open Architecture SDR for Space

NASA Technical Reports Server (NTRS)

Smith, Carl; Long, Chris; Liebetreu, John; Reinhart, Richard C.

2005-01-01

This paper describes an open-architecture SDR (software defined radio) infrastructure that is suitable for space-based operations (Space-SDR). SDR technologies will endow space and planetary exploration systems with dramatically increased capability, reduced power consumption, and significantly less mass than conventional systems, at costs reduced by vigorous competition, hardware commonality, dense integration, reduced obsolescence, interoperability, and software re-use. Significant progress has been recorded on developments like the Joint Tactical Radio System (JSTRS) Software Communication Architecture (SCA), which is oriented toward reconfigurable radios for defense forces operating in multiple theaters of engagement. The JTRS-SCA presents a consistent software interface for waveform development, and facilitates interoperability, waveform portability, software re-use, and technology evolution.

Investigating the Acquisition of Software Systems that Rely on Open Architecture and Open Source Software

DTIC Science & Technology

2010-03-01

associated with certain software systems [Breaux and Anton 2008]. With this basis to build on, it is now possible to analyze the alignment of...Kazman, R., (2003). Software Architecture in Practice, 2nd Edition, Addison-Wesley Pro- fessional, New York.. Breaux, T.D. and Anton , A.I. (2008... calculus for license rights and obligations in license and context models. Using them, we calculate rights and obligations for specific sys- tems, identify

How the Navy Can Use Open Systems Architecture to Revolutionize Capability Acquisition: The Naval OSA Strategy Can Yield Multiple Benefits

DTIC Science & Technology

2015-04-30

and Data Rights Team, which supports the Better Buying Power initiatives. Robert Sweeney—is the Lead Avionics Architect for Naval Air Systems...open architecture strategies for naval aviation. Sweeney was previously employed by Rockwell Collins as a software engineer for avionics . He earned his...the rapid replacement and upgrade of capabilities to address warfighter needs (Assistant Secretary of the Navy for Research, Development, and

Validation of the openEHR archetype library by using OWL reasoning.

PubMed

Menárguez-Tortosa, Marcos; Fernández-Breis, Jesualdo Tomás

2011-01-01

Electronic Health Record architectures based on the dual model architecture use archetypes for representing clinical knowledge. Therefore, ensuring their correctness and consistency is a fundamental research goal. In this work, we explore how an approach based on OWL technologies can be used for such purpose. This method has been applied to the openEHR archetype repository, which is the largest available one nowadays. The results of this validation are also reported in this study.

Spectroscopic analyses of the parent stars of extrasolar planetary system candidates

NASA Astrophysics Data System (ADS)

Gonzalez, Guillermo

1998-06-01

The stars rho () 1 Cnc, rho CrB, 16 Cyg B, 51 Peg, 47 UMa, 70 Vir, and HD 114762 have recently been proposed to harbor planetary mass companions based on small amplitude radial velocity variations. From spectroscopic analyses we derive the following values of [Fe/H] for these stars: 0.29, -0.29, 0.06, 0.21, 0.01, -0.03, and -0.60 (all with an uncertainty of 0.06 dex), respectively; the [Fe/H] value for 16 Cyg A is 0.11. The four 51 Peg-like systems, upsilon And, tau Boo, rho () 1 Cnc, and 51 Peg, have a mean [Fe/H] value of 0.25. Otherwise, the abundance patterns, expressed as [X/Fe], are approximately solar. We used Fourier analysis, supplemented by line profile synthesis, to derive the following v sin i values: <1.3, 1.4 +/- 0.3, 1.7 +/- 0.4, < 0.5, and < 1.5 km s(-1) for rho () 1 Cnc, 51 Peg, 47 UMa, 70 Vir, and HD 114762, respectively. A similar analysis of the spectrum of rho CrB (with a lower resolving power) yields a value of ~ 1.5 km s() -1. Combining these data with published estimates of v sin i and rotation periods and assuming that the radial velocity variations are due to the presence of planets, we derive the following masses for the companions: >0.66, 2.9(+13.6}_{-1.3) , 0.49+/-0.03, 3.4() +3.1_-1.1, >9.4, and >10.4 cal M_J for rho () 1 Cnc, rho CrB, 51 Peg, 47 UMa, 70 Vir, and HD 114762, respectively; the mass of 16 Cyg B b, calculated using a published estimate for sin i, is 2.0() +1.1_-0.3 cal M_J. The masses of the companions to upsilon And and tau Boo, which were analyzed in a previous paper, are 0.76() +0.19_-0.03 and 5.9() +43.9_-1.8 cal M_J, respectively. We confirm previous claims that rho () 1 Cnc appears to be a subgiant. However, the theoretical isochrone-derived age is much greater than the age of the universe. At this time we have insufficient data to determine the true nature of rho () 1 Cnc, but we suggest that it may be an unresolved stellar binary viewed nearly pole-on. A search for line profile variations might help to resolve this mystery. Our findings are consistent with a recently proposed mechanism whereby a gas giant migrates to within a few hundredths of an AU of its parent star during the formative epoch of the planetary system, and the material between the planet and the star is accreted onto the latter. If the accreted material is depleted in H and He, then the photospheric composition of the parent star might be altered significantly.

CHRONOS architecture: Experiences with an open-source services-oriented architecture for geoinformatics

USGS Publications Warehouse

Fils, D.; Cervato, C.; Reed, J.; Diver, P.; Tang, X.; Bohling, G.; Greer, D.

2009-01-01

CHRONOS's purpose is to transform Earth history research by seamlessly integrating stratigraphic databases and tools into a virtual on-line stratigraphic record. In this paper, we describe the various components of CHRONOS's distributed data system, including the encoding of semantic and descriptive data into a service-based architecture. We give examples of how we have integrated well-tested resources available from the open-source and geoinformatic communities, like the GeoSciML schema and the simple knowledge organization system (SKOS), into the services-oriented architecture to encode timescale and phylogenetic synonymy data. We also describe on-going efforts to use geospatially enhanced data syndication and informally including semantic information by embedding it directly into the XHTML Document Object Model (DOM). XHTML DOM allows machine-discoverable descriptive data such as licensing and citation information to be incorporated directly into data sets retrieved by users. ?? 2008 Elsevier Ltd. All rights reserved.

Terra Harvest software architecture

NASA Astrophysics Data System (ADS)

Humeniuk, Dave; Klawon, Kevin

2012-06-01

Under the Terra Harvest Program, the DIA has the objective of developing a universal Controller for the Unattended Ground Sensor (UGS) community. The mission is to define, implement, and thoroughly document an open architecture that universally supports UGS missions, integrating disparate systems, peripherals, etc. The Controller's inherent interoperability with numerous systems enables the integration of both legacy and future UGS System (UGSS) components, while the design's open architecture supports rapid third-party development to ensure operational readiness. The successful accomplishment of these objectives by the program's Phase 3b contractors is demonstrated via integration of the companies' respective plug-'n'-play contributions that include controllers, various peripherals, such as sensors, cameras, etc., and their associated software drivers. In order to independently validate the Terra Harvest architecture, L-3 Nova Engineering, along with its partner, the University of Dayton Research Institute, is developing the Terra Harvest Open Source Environment (THOSE), a Java Virtual Machine (JVM) running on an embedded Linux Operating System. The Use Cases on which the software is developed support the full range of UGS operational scenarios such as remote sensor triggering, image capture, and data exfiltration. The Team is additionally developing an ARM microprocessor-based evaluation platform that is both energy-efficient and operationally flexible. The paper describes the overall THOSE architecture, as well as the design decisions for some of the key software components. Development process for THOSE is discussed as well.

SANDS: a service-oriented architecture for clinical decision support in a National Health Information Network.

PubMed

Wright, Adam; Sittig, Dean F

2008-12-01

In this paper, we describe and evaluate a new distributed architecture for clinical decision support called SANDS (Service-oriented Architecture for NHIN Decision Support), which leverages current health information exchange efforts and is based on the principles of a service-oriented architecture. The architecture allows disparate clinical information systems and clinical decision support systems to be seamlessly integrated over a network according to a set of interfaces and protocols described in this paper. The architecture described is fully defined and developed, and six use cases have been developed and tested using a prototype electronic health record which links to one of the existing prototype National Health Information Networks (NHIN): drug interaction checking, syndromic surveillance, diagnostic decision support, inappropriate prescribing in older adults, information at the point of care and a simple personal health record. Some of these use cases utilize existing decision support systems, which are either commercially or freely available at present, and developed outside of the SANDS project, while other use cases are based on decision support systems developed specifically for the project. Open source code for many of these components is available, and an open source reference parser is also available for comparison and testing of other clinical information systems and clinical decision support systems that wish to implement the SANDS architecture. The SANDS architecture for decision support has several significant advantages over other architectures for clinical decision support. The most salient of these are:

77 FR 58210 - 31st Meeting: RTCA Special Committee 206, Aeronautical Information and Meteorological Data Link...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-19

... approve meeting agenda Action item review Sub-Group (SG1--Wake OSED, SG3--Architecture, SG4--DO-252... Architecture(s) AAtS Implementation Guidance Document New Capabilities in Flight Services 1 p.m. Opening... Action item review Future meeting plans and dates Other business 1 p.m. Adjourn (no lunch break) Welcome...

Integration of Sensors, Controllers and Instruments Using a Novel OPC Architecture

PubMed Central

2017-01-01

The interconnection between sensors, controllers and instruments through a communication network plays a vital role in the performance and effectiveness of a control system. Since its inception in the 90s, the Object Linking and Embedding for Process Control (OPC) protocol has provided open connectivity for monitoring and automation systems. It has been widely used in several environments such as industrial facilities, building and energy automation, engineering education and many others. This paper presents a novel OPC-based architecture to implement automation systems devoted to R&D and educational activities. The proposal is a novel conceptual framework, structured into four functional layers where the diverse components are categorized aiming to foster the systematic design and implementation of automation systems involving OPC communication. Due to the benefits of OPC, the proposed architecture provides features like open connectivity, reliability, scalability, and flexibility. Furthermore, four successful experimental applications of such an architecture, developed at the University of Extremadura (UEX), are reported. These cases are a proof of concept of the ability of this architecture to support interoperability for different domains. Namely, the automation of energy systems like a smart microgrid and photobioreactor facilities, the implementation of a network-accessible industrial laboratory and the development of an educational hardware-in-the-loop platform are described. All cases include a Programmable Logic Controller (PLC) to automate and control the plant behavior, which exchanges operative data (measurements and signals) with a multiplicity of sensors, instruments and supervisory systems under the structure of the novel OPC architecture. Finally, the main conclusions and open research directions are highlighted. PMID:28654002

Integration of Sensors, Controllers and Instruments Using a Novel OPC Architecture.

PubMed

González, Isaías; Calderón, Antonio José; Barragán, Antonio Javier; Andújar, José Manuel

2017-06-27

The interconnection between sensors, controllers and instruments through a communication network plays a vital role in the performance and effectiveness of a control system. Since its inception in the 90s, the Object Linking and Embedding for Process Control (OPC) protocol has provided open connectivity for monitoring and automation systems. It has been widely used in several environments such as industrial facilities, building and energy automation, engineering education and many others. This paper presents a novel OPC-based architecture to implement automation systems devoted to R&D and educational activities. The proposal is a novel conceptual framework, structured into four functional layers where the diverse components are categorized aiming to foster the systematic design and implementation of automation systems involving OPC communication. Due to the benefits of OPC, the proposed architecture provides features like open connectivity, reliability, scalability, and flexibility. Furthermore, four successful experimental applications of such an architecture, developed at the University of Extremadura (UEX), are reported. These cases are a proof of concept of the ability of this architecture to support interoperability for different domains. Namely, the automation of energy systems like a smart microgrid and photobioreactor facilities, the implementation of a network-accessible industrial laboratory and the development of an educational hardware-in-the-loop platform are described. All cases include a Programmable Logic Controller (PLC) to automate and control the plant behavior, which exchanges operative data (measurements and signals) with a multiplicity of sensors, instruments and supervisory systems under the structure of the novel OPC architecture. Finally, the main conclusions and open research directions are highlighted.

AKM in Open Source Communities

NASA Astrophysics Data System (ADS)

Stamelos, Ioannis; Kakarontzas, George

Previous chapters in this book have dealt with Architecture Knowledge Management in traditional Closed Source Software (CSS) projects. This chapterwill attempt to examine the ways that knowledge is shared among participants in Free Libre Open Source Software (FLOSS 1) projects and how architectural knowledge is managed w.r.t. CSS. FLOSS projects are organized and developed in a fundamentally different way than CSS projects. FLOSS projects simply do not develop code as CSS projects do. As a consequence, their knowledge management mechanisms are also based on different concepts and tools.

Reconfigurable Transceiver and Software-Defined Radio Architecture and Technology Evaluated for NASA Space Communications

NASA Technical Reports Server (NTRS)

Reinhart, Richard C.; Kacpura, Thomas J.

2004-01-01

The NASA Glenn Research Center is investigating the development and suitability of a software-based open-architecture for space-based reconfigurable transceivers (RTs) and software-defined radios (SDRs). The main objectives of this project are to enable advanced operations and reduce mission costs. SDRs are becoming more common because of the capabilities of reconfigurable digital signal processing technologies such as field programmable gate arrays and digital signal processors, which place radio functions in firmware and software that were traditionally performed with analog hardware components. Features of interest of this communications architecture include nonproprietary open standards and application programming interfaces to enable software reuse and portability, independent hardware and software development, and hardware and software functional separation. The goals for RT and SDR technologies for NASA space missions include prelaunch and on-orbit frequency and waveform reconfigurability and programmability, high data rate capability, and overall communications and processing flexibility. These operational advances over current state-of-art transceivers will be provided to reduce the power, mass, and cost of RTs and SDRs for space communications. The open architecture for NASA communications will support existing (legacy) communications needs and capabilities while providing a path to more capable, advanced waveform development and mission concepts (e.g., ad hoc constellations with self-healing networks and high-rate science data return). A study was completed to assess the state of the art in RT architectures, implementations, and technologies. In-house researchers conducted literature searches and analysis, interviewed Government and industry contacts, and solicited information and white papers from industry on space-qualifiable RTs and SDRs and their associated technologies for space-based NASA applications. The white papers were evaluated, compiled, and used to assess RT and SDR system architectures and core technology elements to determine an appropriate investment strategy to advance these technologies to meet future mission needs. The use of these radios in the space environment represents a challenge because of the space radiation suitability of the components, which drastically reduces the processing capability. The radios available for space are considered to be RTs (as opposed to SDRs), which are digitally programmable radios with selectable changes from an architecture combining analog and digital components. The limited flexibility of this design contrasts against the desire to have a power-efficient solution and open architecture.

IRAF and STSDAS under the new ALPHA architecture

NASA Technical Reports Server (NTRS)

Zarate, N. R.

1992-01-01

Digital's next generation RISC architecture, known as ALPHA, presents many IRAF system portability questions and challenges to both site managers and end users. DEC promises to support the ULTRIX, VMS, and OSF/1 operating systems, which should allow IRAF to be ported to the new architecture at either the program executable level (using VEST), or at the source level, where IRAF can be tuned for greater performance. These notes highlight some of the details of porting IRAF to OpenVMS on the ALPHA architecture.

Simultaneous identification of multi-combustion-intermediates of alkanol-air flames by femtosecond filament excitation for combustion sensing.

PubMed

Li, Helong; Chu, Wei; Xu, Huailiang; Cheng, Ya; Chin, See-Leang; Yamanouchi, Kaoru; Sun, Hong-Bo

2016-06-02

Laser filamentation produced by the propagation of intense laser pulses in flames is opening up new possibility in application to combustion diagnostics that can provide useful information on understanding combustion processes, enhancing combustion efficiency and reducing pollutant products. Here we present simultaneous identification of multiple combustion intermediates by femtosecond filament excitation for five alkanol-air flames fueled by methanol, ethanol, n-propanol, n-butanol, and n-pentanol. We experimentally demonstrate that the intensities of filament-induced photoemission signals from the combustion intermediates C, C2, CH, CN increase with the increasing number of carbons in the fuel molecules, and the signal ratios between the intermediates (CH/C, CH/C2, CN/C, CH/C2, CN/CH) are different for different alkanol combustion flames. Our observation provides a way for sensing multiple combustion components by femtosecond filament excitation in various combustion conditions that strongly depend on the fuel species.

FPGA-Based Fused Smart-Sensor for Tool-Wear Area Quantitative Estimation in CNC Machine Inserts

PubMed Central

Trejo-Hernandez, Miguel; Osornio-Rios, Roque Alfredo; de Jesus Romero-Troncoso, Rene; Rodriguez-Donate, Carlos; Dominguez-Gonzalez, Aurelio; Herrera-Ruiz, Gilberto

2010-01-01

Manufacturing processes are of great relevance nowadays, when there is a constant claim for better productivity with high quality at low cost. The contribution of this work is the development of a fused smart-sensor, based on FPGA to improve the online quantitative estimation of flank-wear area in CNC machine inserts from the information provided by two primary sensors: the monitoring current output of a servoamplifier, and a 3-axis accelerometer. Results from experimentation show that the fusion of both parameters makes it possible to obtain three times better accuracy when compared with the accuracy obtained from current and vibration signals, individually used. PMID:22319304

Engineering hurdles in contact and intraocular lens lathe design: the view ahead

NASA Astrophysics Data System (ADS)

Bradley, Norman D.; Keller, John R.; Ball, Gary A.

1994-05-01

Current trends in and intraocular lens design suggest ever- increasing demand for aspheric lens geometries - multisurface and/or toric surfaces - in a variety of new materials. As computer numeric controls (CNC) lathes and mills continue to evolve with he ophthalmic market, engineering hurdles present themselves to designers: Can hardware based upon single-point diamond turning accommodate the demands of software-driven designs? What are the limits of CNC resolution and repeatability in high-throughput production? What are the controlling factors in lathed, polish-free surface production? Emerging technologies in the lathed biomedical optics field are discussed along with their limitations, including refined diamond tooling, vibrational control, automation, and advanced motion control systems.

Light-curve solutions for S Cancri and TT Hydrae with rapid rotation

NASA Technical Reports Server (NTRS)

Van Hamme, W.; Wilson, R. E.

1993-01-01

Physical model light- and velocity-curve solutions for S Cancri and TT Hydrae are obtained, and analyses with incorporation of asynchronous rotation are carried out. A photometric rotation rate for the primary star of TT Hya is determined, and excellent agreement with results from spectral line profiles is found. Both separate light- and velocity-curve solutions and simultaneous light-velocity solutions are listed. The photometric rotation for S Cnc from existing light curves is indeterminate, but is compatible with line profile measures. Evidence for third light from the light curves of S Cnc is found. An explanation for the apparent conflict between the rotational states and mass-transfer activities of the two binaries is suggested.

Use of Open Architecture Middleware for Autonomous Platforms

NASA Astrophysics Data System (ADS)

Naranjo, Hector; Diez, Sergio; Ferrero, Francisco

2011-08-01

Network Enabled Capabilities (NEC) is the vision for next-generation systems in the defence domain formulated by governments, the European Defence Agency (EDA) and the North Atlantic Treaty Organization (NATO). It involves the federation of military information systems, rather than just a simple interconnection, to provide each user with the "right information, right place, right time - and not too much". It defines openness, standardization and flexibility principles in military systems, likewise applicable in the civilian space applications.This paper provides the conclusions drawn from "Architecture for Embarked Middleware" (EMWARE) study, funded by the European Defence Agency (EDA).The aim of the EMWARE project was to provide the information and understanding to facilitate the adoption of informed decisions regarding the specification and implementation of Open Architecture Middleware in future distributed systems, linking it with the NEC goal.EMWARE project included the definition of four business cases, each devoted to a different field of application (Unmanned Aerial Vehicles, Helicopters, Unmanned Ground Vehicles and the Satellite Ground Segment).

Portable Cytometry Using Microscale Electronic Sensing

PubMed Central

Emaminejad, Sam; Paik, Kee-Hyun; Tabard-Cossa, Vincent; Javanmard, Mehdi

2015-01-01

In this manuscript, we present three different micro-impedance sensing architectures for electronic counting of cells and beads. The first method of sensing is based on using an open circuit sensing electrode integrated in a micro-pore, which measures the shift in potential as a micron-sized particle passes through. Our micro-pore, based on a funnel shaped microchannel, was fabricated in PDMS and was bound covalently to a glass substrate patterned with a gold open circuit electrode. The amplification circuitry was integrated onto a battery-powered custom printed circuit board. The second method is based on a three electrode differential measurement, which opens up the potential of using signal processing techniques to increase signal to noise ratio post measurement. The third architecture uses a contactless sensing approach, which significantly minimizes the cost of the consumable component of the impedance cytometer. We demonstrated proof of concept for the three sensing architectures by measuring the detected signal due to the passage of micron sized beads through the pore. PMID:27647950

Space Telecommunications Radio System (STRS) Architecture Goals/Objectives and Level 1 Requirements

NASA Technical Reports Server (NTRS)

Briones, Janette C.; Johnson, Sandra K.; VanDerAar, Lisa

2007-01-01

The Space Telecommunications Radio System (STRS) Architecture Requirements Document provides the basis for the development of an open architecture for NASA Software Defined Radios (SDRs) for space use. The main objective of this document is to evaluate the goals and objectives and high level (Level 1) requirements that have bearing on the design of the architecture. The goals and objectives will provide broad, fundamental direction and purpose. The high level requirements (Level 1) intend to guide the broader and longer term aspects aspects of the SDR Architecture and provide guidance for the development of level 2 requirements.

Digital synchronization and communication techniques

NASA Technical Reports Server (NTRS)

Lindsey, William C.

1992-01-01

Information on digital synchronization and communication techniques is given in viewgraph form. Topics covered include phase shift keying, modems, characteristics of open loop digital synchronizers, an open loop phase and frequency estimator, and a digital receiver structure using an open loop estimator in a decision directed architecture.

The Light Plane Calibration Method of the Laser Welding Vision Monitoring System

NASA Astrophysics Data System (ADS)

Wang, B. G.; Wu, M. H.; Jia, W. P.

2018-03-01

According to the aerospace and automobile industry, the sheet steels are the very important parts. In the recent years, laser welding technique had been used to weld the sheet steel part. The seam width between the two parts is usually less than 0.1mm. Because the error of the fixture fixed can’t be eliminated, the welding parts quality can be greatly affected. In order to improve the welding quality, the line structured light is employed in the vision monitoring system to plan the welding path before welding. In order to improve the weld precision, the vision system is located on Z axis of the computer numerical control (CNC) tool. The planar pattern is placed on the X-Y plane of the CNC tool, and the structured light is projected on the planar pattern. The vision system stay at three different positions along the Z axis of the CNC tool, and the camera shoot the image of the planar pattern at every position. Using the calculated the sub-pixel center line of the structure light, the world coordinate of the center light line can be calculated. Thus, the structured light plane can be calculated by fitting the structured light line. Experiment result shows the effective of the proposed method.

Spider Silk-CBD-Cellulose Nanocrystal Composites: Mechanism of Assembly

PubMed Central

Meirovitch, Sigal; Shtein, Zvi; Ben-Shalom, Tal; Lapidot, Shaul; Tamburu, Carmen; Hu, Xiao; Kluge, Jonathan A.; Raviv, Uri; Kaplan, David L.; Shoseyov, Oded

2016-01-01

The fabrication of cellulose-spider silk bio-nanocomposites comprised of cellulose nanocrystals (CNCs) and recombinant spider silk protein fused to a cellulose binding domain (CBD) is described. Silk-CBD successfully binds cellulose, and unlike recombinant silk alone, silk-CBD self-assembles into microfibrils even in the absence of CNCs. Silk-CBD-CNC composite sponges and films show changes in internal structure and CNC alignment related to the addition of silk-CBD. The silk-CBD sponges exhibit improved thermal and structural characteristics in comparison to control recombinant spider silk sponges. The glass transition temperature (Tg) of the silk-CBD sponge was higher than the control silk sponge and similar to native dragline spider silk fibers. Gel filtration analysis, dynamic light scattering (DLS), small angle X-ray scattering (SAXS) and cryo-transmission electron microscopy (TEM) indicated that silk-CBD, but not the recombinant silk control, formed a nematic liquid crystalline phase similar to that observed in native spider silk during the silk spinning process. Silk-CBD microfibrils spontaneously formed in solution upon ultrasonication. We suggest a model for silk-CBD assembly that implicates CBD in the central role of driving the dimerization of spider silk monomers, a process essential to the molecular assembly of spider-silk nanofibers and silk-CNC composites. PMID:27649169

Cohesin regulates tissue-specific expression by stabilizing highly occupied cis-regulatory modules

PubMed Central

Faure, Andre J.; Schmidt, Dominic; Watt, Stephen; Schwalie, Petra C.; Wilson, Michael D.; Xu, Huiling; Ramsay, Robert G.; Odom, Duncan T.; Flicek, Paul

2012-01-01

The cohesin protein complex contributes to transcriptional regulation in a CTCF-independent manner by colocalizing with master regulators at tissue-specific loci. The regulation of transcription involves the concerted action of multiple transcription factors (TFs) and cohesin's role in this context of combinatorial TF binding remains unexplored. To investigate cohesin-non-CTCF (CNC) binding events in vivo we mapped cohesin and CTCF, as well as a collection of tissue-specific and ubiquitous transcriptional regulators using ChIP-seq in primary mouse liver. We observe a positive correlation between the number of distinct TFs bound and the presence of CNC sites. In contrast to regions of the genome where cohesin and CTCF colocalize, CNC sites coincide with the binding of master regulators and enhancer-markers and are significantly associated with liver-specific expressed genes. We also show that cohesin presence partially explains the commonly observed discrepancy between TF motif score and ChIP signal. Evidence from these statistical analyses in wild-type cells, and comparisons to maps of TF binding in Rad21-cohesin haploinsufficient mouse liver, suggests that cohesin helps to stabilize large protein–DNA complexes. Finally, we observe that the presence of mirrored CTCF binding events at promoters and their nearby cohesin-bound enhancers is associated with elevated expression levels. PMID:22780989

The effect of temporal gap identification on speech perception by users of cochlear implants

PubMed Central

Sagi, Elad; Kaiser, Adam R.; Meyer, Ted A.; Svirsky, Mario A.

2008-01-01

Purpose This study examined the ability of listeners using cochlear implants (CIs) and listeners with normal-hearing (NH) to identify silent gaps of different duration, and the relation of this ability to speech understanding in CI users. Method Sixteen NH adults and eleven postlingually deafened adults with CIs identified synthetic vowel-like stimuli that were either continuous or contained an intervening silent gap ranging from 15 to 90 ms. Cumulative d’, an index of discriminability, was calculated for each participant. Consonant and CNC word identification tasks were administered to the CI group. Results Overall, the ability to identify stimuli with gaps of different duration was better for the NH group than for the CI group. Seven CI users had cumulative d' scores that were no higher than those of any NH listener, and their CNC word scores ranged from 0 to 30%. The other four CI users had cumulative d’ scores within the range of the NH group, and their CNC word scores ranged from 46% to 68%. For the CI group, cumulative d’ scores were significantly correlated with their speech testing scores. Conclusions The ability to identify silent gap duration may help explain individual differences in speech perception by CI users. PMID:18806216

Thermal stability increase in metallic nanoparticles-loaded cellulose nanocrystal nanocomposites.

PubMed

Goikuria, U; Larrañaga, A; Vilas, J L; Lizundia, E

2017-09-01

Due to the potential of CNC-based flexible materials for novel industrial applications, the aim of this work is to improve the thermal stability of cellulose nanocrystals (CNC) films through a straightforward and scalable method. Based of nanocomposite approach, five different metallic nanoparticles (ZnO, SiO 2 , TiO 2 , Al 2 O 3 and Fe 2 O 3 ) have been co-assembled in water with CNCs to obtain free-standing nanocomposite films. Thermogravimetric analysis (TGA) reveals an increased thermal stability upon nanoparticle. This increase in the thermal stability reaches a maximum of 75°C for the nanocomposites having 10wt% of Fe 2 O 3 and ZnO. The activation energies of thermodegradation process (E a ) determined according to Kissinger and Ozawa-Flynn-Wall methods further confirm the delayed degradation of CNC nanocomposites upon heating. Finally, the changes induced in the crystalline structure during thermodegradation were followed by wide angle X-ray diffraction (WAXD). It is also observed that thermal degradation proceeds at higher temperatures for nanocomposites having metallic nanoparticles. Overall, experimental findings here showed make nanocomposite approach a simple low-cost environmentally-friendly strategy to overcome the relatively poor thermal stability of CNCs when extracted via sulfuric acid assisted hydrolysis of cellulose. Copyright © 2017 Elsevier Ltd. All rights reserved.

GROUND-BASED TRANSIT OBSERVATIONS OF THE SUPER-EARTH 55 Cnc e

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

De Mooij, E. J. W.; López-Morales, M.; Karjalainen, R.

2014-12-20

We report the first ground-based detections of the shallow transit of the super-Earth exoplanet 55 Cnc e using a 2 m class telescope. Using differential spectrophotometry, we observed one transit in 2013 and another in 2014, with average spectral resolutions of ∼700 and ∼250, spanning the Johnson BVR photometric bands. We find a white light planet-to-star radius ratio of 0.0190{sub −0.0027}{sup +0.0023} from the 2013 observations and 0.0200{sub −0.0018}{sup +0.0017} from the 2014 observations. The two data sets combined result in a radius ratio of 0.0198{sub −0.0014}{sup +0.0013}. These values are all in agreement with previous space-based results. Scintillation noise in themore » data prevents us from placing strong constraints on the presence of an extended hydrogen-rich atmosphere. Nevertheless, our detections of 55 Cnc e in transit demonstrate that moderate-sized telescopes on the ground will be capable of routine follow-up observations of super-Earth candidates discovered by the Transiting Exoplanet Survey Satellite around bright stars. We expect it also will be possible to place constraints on the atmospheric characteristics of those planets by devising observational strategies to minimize scintillation noise.« less

AT Cnc: A SECOND DWARF NOVA WITH A CLASSICAL NOVA SHELL

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

Shara, Michael M.; Mizusawa, Trisha; Zurek, David

2012-10-20

We are systematically surveying all known and suspected Z Cam-type dwarf novae for classical nova shells. This survey is motivated by the discovery of the largest known classical nova shell, which surrounds the archetypal dwarf nova Z Camelopardalis. The Z Cam shell demonstrates that at least some dwarf novae must have undergone classical nova eruptions in the past, and that at least some classical novae become dwarf novae long after their nova thermonuclear outbursts, in accord with the hibernation scenario of cataclysmic binaries. Here we report the detection of a fragmented 'shell', 3 arcmin in diameter, surrounding the dwarf novamore » AT Cancri. This second discovery demonstrates that nova shells surrounding Z Cam-type dwarf novae cannot be very rare. The shell geometry is suggestive of bipolar, conical ejection seen nearly pole-on. A spectrum of the brightest AT Cnc shell knot is similar to that of the ejecta of the classical nova GK Per, and of Z Cam, dominated by [N II] emission. Galaxy Evolution Explorer FUV imagery reveals a similar-sized, FUV-emitting shell. We determine a distance of 460 pc to AT Cnc, and an upper limit to its ejecta mass of {approx}5 Multiplication-Sign 10{sup -5} M {sub Sun }, typical of classical novae.« less

Potential Applications of Nanocellulose-Containing Materials in the Biomedical Field

PubMed Central

Halib, Nadia; Perrone, Francesca; Dapas, Barbara; Farra, Rossella; Abrami, Michela; Chiarappa, Gianluca; Forte, Giancarlo; Zanconati, Fabrizio; Pozzato, Gabriele; Murena, Luigi; Fiotti, Nicola; Lapasin, Romano; Cansolino, Laura; Grassi, Gabriele

2017-01-01

Because of its high biocompatibility, bio-degradability, low-cost and easy availability, cellulose finds application in disparate areas of research. Here we focus our attention on the most recent and attractive potential applications of cellulose in the biomedical field. We first describe the chemical/structural composition of cellulose fibers, the cellulose sources/features and cellulose chemical modifications employed to improve its properties. We then move to the description of cellulose potential applications in biomedicine. In this field, cellulose is most considered in recent research in the form of nano-sized particle, i.e., nanofiber cellulose (NFC) or cellulose nanocrystal (CNC). NFC is obtained from cellulose via chemical and mechanical methods. CNC can be obtained from macroscopic or microscopic forms of cellulose following strong acid hydrolysis. NFC and CNC are used for several reasons including the mechanical properties, the extended surface area and the low toxicity. Here we present some potential applications of nano-sized cellulose in the fields of wound healing, bone-cartilage regeneration, dental application and different human diseases including cancer. To witness the close proximity of nano-sized cellulose to the practical biomedical use, examples of recent clinical trials are also reported. Altogether, the described examples strongly support the enormous application potential of nano-sized cellulose in the biomedical field. PMID:28825682

Spider Silk-CBD-Cellulose Nanocrystal Composites: Mechanism of Assembly.

PubMed

Meirovitch, Sigal; Shtein, Zvi; Ben-Shalom, Tal; Lapidot, Shaul; Tamburu, Carmen; Hu, Xiao; Kluge, Jonathan A; Raviv, Uri; Kaplan, David L; Shoseyov, Oded

2016-09-18

The fabrication of cellulose-spider silk bio-nanocomposites comprised of cellulose nanocrystals (CNCs) and recombinant spider silk protein fused to a cellulose binding domain (CBD) is described. Silk-CBD successfully binds cellulose, and unlike recombinant silk alone, silk-CBD self-assembles into microfibrils even in the absence of CNCs. Silk-CBD-CNC composite sponges and films show changes in internal structure and CNC alignment related to the addition of silk-CBD. The silk-CBD sponges exhibit improved thermal and structural characteristics in comparison to control recombinant spider silk sponges. The glass transition temperature (Tg) of the silk-CBD sponge was higher than the control silk sponge and similar to native dragline spider silk fibers. Gel filtration analysis, dynamic light scattering (DLS), small angle X-ray scattering (SAXS) and cryo-transmission electron microscopy (TEM) indicated that silk-CBD, but not the recombinant silk control, formed a nematic liquid crystalline phase similar to that observed in native spider silk during the silk spinning process. Silk-CBD microfibrils spontaneously formed in solution upon ultrasonication. We suggest a model for silk-CBD assembly that implicates CBD in the central role of driving the dimerization of spider silk monomers, a process essential to the molecular assembly of spider-silk nanofibers and silk-CNC composites.

CNC machine tool's wear diagnostic and prognostic by using dynamic Bayesian networks

NASA Astrophysics Data System (ADS)

Tobon-Mejia, D. A.; Medjaher, K.; Zerhouni, N.

2012-04-01

The failure of critical components in industrial systems may have negative consequences on the availability, the productivity, the security and the environment. To avoid such situations, the health condition of the physical system, and particularly of its critical components, can be constantly assessed by using the monitoring data to perform on-line system diagnostics and prognostics. The present paper is a contribution on the assessment of the health condition of a computer numerical control (CNC) tool machine and the estimation of its remaining useful life (RUL). The proposed method relies on two main phases: an off-line phase and an on-line phase. During the first phase, the raw data provided by the sensors are processed to extract reliable features. These latter are used as inputs of learning algorithms in order to generate the models that represent the wear's behavior of the cutting tool. Then, in the second phase, which is an assessment one, the constructed models are exploited to identify the tool's current health state, predict its RUL and the associated confidence bounds. The proposed method is applied on a benchmark of condition monitoring data gathered during several cuts of a CNC tool. Simulation results are obtained and discussed at the end of the paper.

Cellulose nanocrystals in nanocomposite approach: Green and high-performance materials for industrial, biomedical and agricultural applications

NASA Astrophysics Data System (ADS)

Fortunati, E.; Torre, L.

2016-05-01

The need to both avoid wastes and find new renewable resources has led to a new and promising research based on the possibility to revalorize the biomass producing sustainable chemicals and/or materials which may play a major role in replacing systems traditionally obtained from non-renewable sources. Most of the low-value biomass is termed lignocellulosic, referring to its main constituent biopolymers: cellulose, hemicelluloses and lignin. In this context, nanocellulose, and in particular cellulose nanocrystals (CNC), have gain considerable attention as nanoreinforcement for polymer matrices, mainly biodegradable. Derived from the most abundant polymeric resource in nature and with inherent biodegradability, nanocellulose is an interesting nanofiller for the development of nanocomposites for industrial, biomedical and agricultural applications. Due to the high amount of hydroxyl groups on their surface, cellulose nanocrystals are easy to functionalize. Well dispersed CNC are able, in fact, to enhance several properties of polymers, i.e.: thermal, mechanical, barrier, surface wettability, controlled of active compound and/or drug release. The main objective here is to give a general overview of CNC applications, summarizing our recent developments of bio-based nanocomposite formulations reinforced with cellulose nanocrystals extracted from different natural sources and/or wastes for food packaging, medical and agricultural sectors.

Increase the elongation at break of poly (lactic acid) composites for use in food packaging films

NASA Astrophysics Data System (ADS)

El-Hadi, Ahmed M.

2017-05-01

Poly (3-hydroxy butyrate) (PHB), cellulose nano crystal (CNC) and a plasticizer (TBC) are mixed together with PLLA with the aim to increase the elongation at break for use in the food packing sector. Spherical (CNC) and fibril nano crystal (CNF) were prepared by hydrolysis of microcrystalline cellulose (MCC) in distilled water, and then stirred using a magnetic stirrer for 15 days and ultrasonic treatment without using any acids as green method. The morphology, thermal, and mechanical properties were studied using POM, DSC, WAXD, SEM and tensile testing, respectively. DSC demonstrated that the addition of PHB, CNC and TBC to PLLA matrix lead to reduce Tg, TCC and Tm than pure PLLA. FT-IR verified that the carbonyl group C=O appeared broad and some peaks in the PLLA composites 5, 6 and 7 shifted from 3.98 × 108 to 4.07 × 108 Hz, at 3.54 × 108 to 3.44 × 108 Hz, at 3.19 × 108 to 3.13 × 108 Hz. Mechanical testing shows that pure PLLA is brittle, and the elongation at break of PLLA composites reaches up to 205%, making it suitable to use in food packaging.

Cushing Syndrome in Carney Complex: Clinical, Pathologic, and Molecular Genetic Findings in the 17 Affected Mayo Clinic Patients.

PubMed

Lowe, Kathleen M; Young, William F; Lyssikatos, Charalampos; Stratakis, Constantine A; Carney, J Aidan

2017-02-01

Carney complex (CNC) is a rare dominantly inherited multiorgan tumoral disorder that includes Cushing syndrome (CS). To establish the Mayo Clinic experience with the CS component, including its clinical, laboratory, and pathologic findings, we performed a retrospective search of the patient and pathologic databases of Mayo Clinic in Rochester, MN, for patients with CNC and clinical or laboratory findings of CS. Thirty-seven patients with CNC were identified. Twenty-nine had clinical, pathologic, or laboratory evidence of an adrenocortical disorder. Seventeen had classic CS; 15 underwent bilateral, subtotal, or partial unilateral adrenalectomy, and 2 had no treatment. Pathologically, the glands were normal sized or slightly enlarged with multiple small (1 to 4 mm), brown, black, and yellow micronodules (primary pigmented nodular adrenocortical disease; PPNAD). Three glands each had a mass: a 2 cm adenoma, a 1.5 cm macronodule, and an unencapsulated 1.8 cm myelolipoma. Fourteen of the patients were alive at follow-up, and 3 were deceased; 2 of the latter had PPNAD at autopsy, and the third had PPNAD at surgery. Twelve patients without clinical features of classic CS had abnormal adrenocortical testing results; none developed classic CS during follow-up (mean, 10 y). Autopsy findings in 1 showed bilateral vacuolated cell cortical hyperplasia.