A case study of learning writing in service-learning through CMC

Science.gov (United States)

Li, Yunxiang; Ren, LiLi; Liu, Xiaomian; Song, Yinjie; Wang, Jie; Li, Jiaxin

2011-06-01

Computer-mediated communication ( CMC ) through online has developed successfully with its adoption by educators. Service Learning is a teaching and learning strategy that integrates community service with academic instruction and reflection to enrich students further understanding of course content, meet genuine community needs, develop career-related skills, and become responsible citizens. This study focuses on an EFL writing learning via CMC in an online virtual environment of service places by taking the case study of service Learning to probe into the scoring algorithm in CMC. The study combines the quantitative and qualitative research to probe into the practical feasibility and effectiveness of EFL writing learning via CMC in service learning in China.

Radiation Synthesis of Super absorbent CMC Based Hydrogels For Agriculture Applications

International Nuclear Information System (INIS)

Raafat, A.I.; Eid, M.; El-Arnaouty, M.B.

2010-01-01

A good hydrogels of carboxy methyl cellulose (CMC) and poly vinyl pyrrolidone (PVP) were synthesized by gamma radiation at different doses and compositions. The prepared hydrogels were characterized by (FTIR) and (SEM). The hydrogels properties such as gelation (%), swelling and water retention capability were investigated. As the content of PVP in PVP/CMC hydrogels increased the gelation (%) increased. The swelling ratio of prepared hydrogel decreased with increasing of irradiation doses and the temperature. The (PVP/CMC) hydrogen of composition (40:60) prepared at 20 kGy showed the highest swelling ratio. The addition of sodium bicarbonate (NaHCO 3 ) to the PVP/CMC hydrogels during the irradiation process decreases the swelling ratio. The water retention reveals a similar behavior for the different compositions. The swelling characteristics in the presence of different cations and anions in a swelling medium were studied. The hydrogels were also loaded with urea solutions as a model agrochemical and their potential application for controlled release has been investigated. The improve properties of the prepared materials suggested that, the (PVP/CMC) hydrogels can be use in agriculture applications

Development of the Virginia Tech Department of Geosciences MEDL-CMC

Science.gov (United States)

Glesener, G. B.

2016-12-01

In 2015 the Virginia Tech Department of Geosciences took a leading role in increasing the level of support for Geoscience instructors by investing in the development of the Geosciences Modeling and Educational Demonstrations Laboratory Curriculum Materials Center (MEDL-CMC). The MEDL-CMC is an innovative curriculum materials center designed to foster new collaborative teaching and learning environments by providing hands-on physical models combined with education technology for instructors and outreach coordinators. The mission of the MEDL-CMC is to provide advanced curriculum material resources for the purpose of increasing and sustaining high impact instructional capacity in STEM education for both formal and informal learning environments. This presentation describes the development methods being used to implement the MEDL-CMC. Major development methods include: (1) adopting a project management system to support collaborations with stakeholders, (2) using a diversified funding approach to achieve financial sustainability and the ability to evolve with the educational needs of the community, and (3) establishing a broad collection of systems-based physical analog models and data collection tools to support integrated sciences such as the geosciences. Discussion will focus on how these methods are used for achieving organizational capacity in the MEDL-CMC and on their intended role in reducing instructor workload in planning both classroom activities and research grant broader impacts.

SYLRAMICTM SiC fibers for CMC reinforcement

International Nuclear Information System (INIS)

Jones, Richard E.; Petrak, Dan; Rabe, Jim; Szweda, Andy

2000-01-01

Dow Corning researchers developed SYLRAMIC SiC fiber specifically for use in ceramic-matrix composite (CMC) components for use in turbine engine hot sections where excellent thermal stability, high strength and high thermal conductivity are required. This is a stoichiometric SiC fiber with a high degree of crystallinity, high tensile strength, high tensile modulus and good thermal conductivity. Owing to the small diameter, this textile-grade fiber can be woven into 2-D and 3-D structures for CMC fabrication. These properties are also of high interest to the nuclear community. Some initial studies have shown that SYLRAMIC fiber shows very good dimensional stability in a neutron flux environment, which offers further encouragement. This paper will review the properties of SYLRAMIC SiC fiber and then present the properties of polymer impregnation and pyrolysis (PIP) processed CMC made with this fiber at Dow Corning. While these composites may not be directly applicable to applications of interest to this audience, we believe that the properties shown will give good evidence that the fiber should be suitable for high temperature structural applications in the nuclear arena

Thin-walled reinforcement lattice structure for hollow CMC buckets

Science.gov (United States)

de Diego, Peter

2017-06-27

A hollow ceramic matrix composite (CMC) turbine bucket with an internal reinforcement lattice structure has improved vibration properties and stiffness. The lattice structure is formed of thin-walled plies made of CMC. The wall structures are arranged and located according to high stress areas within the hollow bucket. After the melt infiltration process, the mandrels melt away, leaving the wall structure to become the internal lattice reinforcement structure of the bucket.

Radiation synthesis of superabsorbent CMC based hydrogels for agriculture applications

International Nuclear Information System (INIS)

Raafat, Amany I.; Eid, Mona; El-Arnaouty, Magda B.

2012-01-01

A series of superabsorbent hydrogel based on carboxymethylcellulose (CMC) and polyvinylpyrrolidone (PVP) crosslinked with gamma irradiation have been proposed for agriculture application. The effect of preparation conditions such as feed solution composition and absorbed irradiation dose on the gelation and swelling degree was evaluated. The structure and the morphology of the superabsorbent CMC/PVP hydrogel were characterized using Fourier transform infrared spectroscopy technique (FTIR), and scanning electron microscope (SEM). Effect of ionic strength and cationic and anionic kinds on the swelling behavior of the obtained hydrogel was investigated. Urea as an agrochemical model was loaded onto the obtained hydrogel to provide nitrogen (N) nutrients. The water retention capability and the urea release behavior of the CMC/PVP hydrogels were investigated. It was found that, the obtained CMC/PVP hydrogels have good swelling degree that greatly affected by its composition and absorbed dose. The swelling was also extremely sensitive to the ionic strength and cationic kind. Owing to its considerable slow urea release, good water retention capacity, being economical, and environment-friendly, it might be useful for its application in agriculture field.

Radiation synthesis of superabsorbent CMC based hydrogels for agriculture applications

Science.gov (United States)

Raafat, Amany I.; Eid, Mona; El-Arnaouty, Magda B.

2012-07-01

A series of superabsorbent hydrogel based on carboxymethylcellulose (CMC) and polyvinylpyrrolidone (PVP) crosslinked with gamma irradiation have been proposed for agriculture application. The effect of preparation conditions such as feed solution composition and absorbed irradiation dose on the gelation and swelling degree was evaluated. The structure and the morphology of the superabsorbent CMC/PVP hydrogel were characterized using Fourier transform infrared spectroscopy technique (FTIR), and scanning electron microscope (SEM). Effect of ionic strength and cationic and anionic kinds on the swelling behavior of the obtained hydrogel was investigated. Urea as an agrochemical model was loaded onto the obtained hydrogel to provide nitrogen (N) nutrients. The water retention capability and the urea release behavior of the CMC/PVP hydrogels were investigated. It was found that, the obtained CMC/PVP hydrogels have good swelling degree that greatly affected by its composition and absorbed dose. The swelling was also extremely sensitive to the ionic strength and cationic kind. Owing to its considerable slow urea release, good water retention capacity, being economical, and environment-friendly, it might be useful for its application in agriculture field.

Radiation synthesis of superabsorbent CMC based hydrogels for agriculture applications

Energy Technology Data Exchange (ETDEWEB)

Raafat, Amany I., E-mail: ismaelraafat_a@hotmail.com [Polymer Chemistry Department, National Center for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt); Eid, Mona; El-Arnaouty, Magda B. [Polymer Chemistry Department, National Center for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt)

2012-07-15

A series of superabsorbent hydrogel based on carboxymethylcellulose (CMC) and polyvinylpyrrolidone (PVP) crosslinked with gamma irradiation have been proposed for agriculture application. The effect of preparation conditions such as feed solution composition and absorbed irradiation dose on the gelation and swelling degree was evaluated. The structure and the morphology of the superabsorbent CMC/PVP hydrogel were characterized using Fourier transform infrared spectroscopy technique (FTIR), and scanning electron microscope (SEM). Effect of ionic strength and cationic and anionic kinds on the swelling behavior of the obtained hydrogel was investigated. Urea as an agrochemical model was loaded onto the obtained hydrogel to provide nitrogen (N) nutrients. The water retention capability and the urea release behavior of the CMC/PVP hydrogels were investigated. It was found that, the obtained CMC/PVP hydrogels have good swelling degree that greatly affected by its composition and absorbed dose. The swelling was also extremely sensitive to the ionic strength and cationic kind. Owing to its considerable slow urea release, good water retention capacity, being economical, and environment-friendly, it might be useful for its application in agriculture field.

PENGARUH PENAMBAHAN CMC SEBAGAI SENYAWA PENSTABIL TERHADAP YOGHURT TEPUNG GEMBILI

Directory of Open Access Journals (Sweden)

Dewi Cakrawati

2016-12-01

Full Text Available The study aims to determine the effect of CMC in preventing yoghurt separation in 7 days with the addition of 2% Dioscorea esculenta flour. Organoleptic test using quality hedonic was conducting to find out yoghurt with addition of CMC that had accepted characteristic by panelists. Research was carried out using regression method to determine the total titrated acid, pH and separation level of yoghurt during storage. The concentrations of CMC were added at 0.2%, 0.4%, 0.6%, 0.8%. The analysis showed the addition of 0.6% CMC showed the lowest separation with high viscosity grades of DPAs 40.25. Yoghurt storage for 7 days shows a graph of the pH value and total titrated acid were parabolic where increasing in total titrated acid value would lower the pH value. Yoghurt was damaged on the 7th day of storage at room temperature characterized by the increasing in the pH value and damage to the organoleptics properties, namely yoghurt flavor and aroma.

Space-Time Crystal and Space-Time Group.

Science.gov (United States)

Xu, Shenglong; Wu, Congjun

2018-03-02

Crystal structures and the Bloch theorem play a fundamental role in condensed matter physics. We extend the static crystal to the dynamic "space-time" crystal characterized by the general intertwined space-time periodicities in D+1 dimensions, which include both the static crystal and the Floquet crystal as special cases. A new group structure dubbed a "space-time" group is constructed to describe the discrete symmetries of a space-time crystal. Compared to space and magnetic groups, the space-time group is augmented by "time-screw" rotations and "time-glide" reflections involving fractional translations along the time direction. A complete classification of the 13 space-time groups in one-plus-one dimensions (1+1D) is performed. The Kramers-type degeneracy can arise from the glide time-reversal symmetry without the half-integer spinor structure, which constrains the winding number patterns of spectral dispersions. In 2+1D, nonsymmorphic space-time symmetries enforce spectral degeneracies, leading to protected Floquet semimetal states. We provide a general framework for further studying topological properties of the (D+1)-dimensional space-time crystal.

Postoperative intra-abdominal collections using a sodium hyaluronate-carboxymethylcellulose (HA-CMC) barrier at the time of laparotomy for uterine or cervical cancers.

Science.gov (United States)

Leitao, Mario M; Byrum, Graham V; Abu-Rustum, Nadeem R; Brown, Carol L; Chi, Dennis S; Sonoda, Yukio; Levine, Douglas A; Gardner, Ginger J; Barakat, Richard R

2010-11-01

A prior analysis of patients undergoing laparotomy for ovarian malignancies at our institution revealed an increased rate of intra-abdominal collections using HA-CMC film during debulking surgery. The primary objective of the current study was to determine whether the use of HA-CMC is associated with the development of postoperative intra-abdominal collections in patients undergoing laparotomy for uterine or cervical malignancies. We retrospectively identified all laparotomies performed for these malignancies from 3/1/05 to 12/31/07. We identified cases involving the use of HA-CMC via billing records and operative reports. Intra-abdominal collections were defined as localized intraperitoneal fluid accumulations in the absence of re-accumulating ascites. We noted incidences of intra-abdominal collections, as well as other complications. Appropriate statistical tests were applied using SPSS 15.0. We identified 169 laparotomies in which HA-CMC was used and 347 in which HA-CMC was not used. The following were statistically similar in both cohorts: age, body mass index (BMI), primary site, surgery for recurrent disease, prior intraperitoneal surgery, and extent of current surgery. Intra-abdominal collections were seen in 6 (3.6%) of 169 HA-CMC cases compared to 10 (2.9%) of 347 non-HA-CMC cases (p=0.7). The rate of infected collections was similar in both groups (1.2% vs. 1.4%). In the subgroup that underwent tumor debulking, intra-abdominal collections were seen in 3 (11.5%) of 26 HA-CMC cases compared to 2 (5.4%) of 37 non-HA-CMC cases (p=0.6). HA-CMC use does not appear to be associated with postoperative intra-abdominal collections in patients undergoing laparotomy for uterine or cervical cancer. Copyright © 2010 Elsevier Inc. All rights reserved.

Preparation of crosslinked carboxymethylcellulose (CMC) by 60 Co γ-ray irradiation and its biodegradable properties

International Nuclear Information System (INIS)

Lim, Youn Mook; Lee, Joon Ho; Nho, Young Chang; Son, Tae Il

2007-01-01

Biodegradable and biocompatible carboxymethylcellulose (CMC) hydrogels for personal care products such as infants diapers and feminine hygiene products were prepared by a γ- irradiation crosslinking technique. Hydrogels were prepared as a function of the CMC concentration, total dose, and degree of substitution (DS), and their physical properties such as the gel fraction, swelling ratio, pH-responsibility and biodegradability were investigated. The irradiation of an aqueous CMC solution led to a gelation in an aqueous solution of more than 10 w%, and the gel percent increased as the CMC concentration, total dose and DS increased. The equilibrium swelling behaviors of the hydrogels prepared in various conditions were examined in an aqueous solution, and the pH-response at a pH of 1.2 and 6.8 was investigated. CMC hydrogels showed a high gelation at a high CMC concentration with DS 1.2. Lastly, the effects of the crosslinking degree of the CMC on the hydrolysis reaction were examined by cellulase from Trichoderma reseei. It was found that the degradable reaction depended on the degree of the crosslinking of the CMC. Intermolecular crosslinking reactions were confirmed by the ESR spectra

Ceramic Matrix Composite (CMC) Thermal Protection Systems (TPS) and Hot Structures for Hypersonic Vehicles

Science.gov (United States)

Glass, David E.

2008-01-01

Thermal protection systems (TPS) and hot structures are required for a range of hypersonic vehicles ranging from ballistic reentry to hypersonic cruise vehicles, both within Earth's atmosphere and non-Earth atmospheres. The focus of this paper is on air breathing hypersonic vehicles in the Earth's atmosphere. This includes single-stage to orbit (SSTO), two-stage to orbit (TSTO) accelerators, access to space vehicles, and hypersonic cruise vehicles. This paper will start out with a brief discussion of aerodynamic heating and thermal management techniques to address the high heating, followed by an overview of TPS for rocket-launched and air-breathing vehicles. The argument is presented that as we move from rocket-based vehicles to air-breathing vehicles, we need to move away from the insulated airplane approach used on the Space Shuttle Orbiter to a wide range of TPS and hot structure approaches. The primary portion of the paper will discuss issues and design options for CMC TPS and hot structure components, including leading edges, acreage TPS, and control surfaces. The current state-of-the-art will be briefly discussed for some of the components. The two primary technical challenges impacting the use of CMC TPS and hot structures for hypersonic vehicles are environmental durability and fabrication, and will be discussed briefly.

Lightweight, Ultra-High-Temperature, CMC-Lined Carbon/Carbon Structures

Science.gov (United States)

Wright, Matthew J.; Ramachandran, Gautham; Williams, Brian E.

2011-01-01

Carbon/carbon (C/C) is an established engineering material used extensively in aerospace. The beneficial properties of C/C include high strength, low density, and toughness. Its shortcoming is its limited usability at temperatures higher than the oxidation temperature of carbon . approximately 400 C. Ceramic matrix composites (CMCs) are used instead, but carry a weight penalty. Combining a thin laminate of CMC to a bulk structure of C/C retains all of the benefits of C/C with the high temperature oxidizing environment usability of CMCs. Ultramet demonstrated the feasibility of combining the light weight of C/C composites with the oxidation resistance of zirconium carbide (ZrC) and zirconium- silicon carbide (Zr-Si-C) CMCs in a unique system composed of a C/C primary structure with an integral CMC liner with temperature capability up to 4,200 F (.2,315 C). The system effectively bridged the gap in weight and performance between coated C/C and bulk CMCs. Fabrication was demonstrated through an innovative variant of Ultramet fs rapid, pressureless melt infiltration processing technology. The fully developed material system has strength that is comparable with that of C/C, lower density than Cf/SiC, and ultra-high-temperature oxidation stability. Application of the reinforced ceramic casing to a predominantly C/C structure creates a highly innovative material with the potential to achieve the long-sought goal of long-term, cyclic high-temperature use of C/C in an oxidizing environment. The C/C substructure provided most of the mechanical integrity, and the CMC strengths achieved appeared to be sufficient to allow the CMC to perform its primary function of protecting the C/C. Nozzle extension components were fabricated and successfully hot-fire tested. Test results showed good thermochemical and thermomechanical stability of the CMC, as well as excellent interfacial bonding between the CMC liner and the underlying C/C structure. In particular, hafnium-containing CMCs on

Preparation of CMC-modified melamine resin spherical nano-phase change energy storage materials.

Science.gov (United States)

Hu, Xiaofeng; Huang, Zhanhua; Zhang, Yanhua

2014-01-30

A novel carboxymethyl cellulose (CMC)-modified melamine-formaldehyde (MF) phase change capsule with excellent encapsulation was prepared by in situ polymerization. Effects of CMC on the properties of the capsules were studied by Fourier transformation infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electronic microscopy (SEM), X-ray diffractometry (XRD), and thermogravimetric analysis (TGA). The results showed that the CMC-modified capsules had an average diameter of about 50nm and good uniformity. The phase change enthalpy of the capsules was increased and the cracking ratio decreased by incorporating a suitable amount of CMC. The optimum phase change enthalpy of the nanocapsules was 83.46J/g, and their paraffin content was 63.1%. The heat resistance of the capsule shells decreased after CMC modification. In addition, the nanocapsule cracking ratio of the nanocapsules was 11.0%, which is highly attractive for their application as nano phase change materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

Biodegradation of PVP-CMC hydrogel film: a useful food packaging material.

Science.gov (United States)

Roy, Niladri; Saha, Nabanita; Kitano, Takeshi; Saha, Petr

2012-06-20

Hydrogels can offer new opportunities for the design of efficient packaging materials with desirable properties (i.e. durability, biodegradability and mechanical strength). It is a promising and emerging concept, as most of the biopolymer based hydrogels are supposed to be biodegradable, they can be considered as alternative eco-friendly packaging materials. This article reports about synthetic (polyvinylpyrrolidone (PVP)) and biopolymer (carboxymethyl cellulose (CMC)) based a novel hydrogel film and its nature of biodegradability under controlled environmental condition. The dry hydrogel films were prepared by solution casting method and designated as 'PVP-CMC hydrogel films'. The hydrogel film containing PVP and CMC in a ratio of 20:80 shows best mechanical properties among all the test samples (i.e. 10:90, 20:80, 50:50, 80:20 and 90:10). Thus, PVP-CMC hydrogel film of 20:80 was considered as a useful food packaging material and further experiments were carried out with this particular hydrogel film. Biodegradation of the PVP-CMC hydrogel films were studied in liquid state (Czapec-Dox liquid medium+soil extracts) until 8 weeks. Variation in mechanical, viscoelastic properties and weight loss of the hydrogel films with time provide the direct evidence of biodegradation of the hydrogels. About 38% weight loss was observed within 8 weeks. FTIR spectra of the hydrogel films (before and after biodegradation) show shifts of the peaks and also change in the peak intensities, which refer to the physico-chemical change in the hydrogel structure and SEM views of the hydrogels show how internal structure of the PVP-CMC film changes in the course of biodegradation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Qualification Approach for the CMC Nose Cap of X-38

Science.gov (United States)

Weihs, H.; Gülhan, A.

2002-01-01

In October 2001 the flight hardware of the TPS nose assembly of X-38 has been installed at the main structure of the X-38 V201 vehicle at NASA's Johnson Space Center, Houston Texas. X-38 is a test vehicle for the planned Crew Return Vehicle CRV for the International Space Station ISS. Currently the flight of the X-38 is scheduled for 2005. Besides the Body flaps (MAN-T) and the nose skirt system (ASTRIUM, MAN-T) the nose cap system is one of the essential hot structure components that were developed within Germany's national TETRA (Technologies for future space transportation systems) programme. The integration of the hardware was an important milestone for the nose cap development which started approx. 5 years ago. DLR-Stuttgart is responsible for the design and manufacturing of the CMC based nose cap system, which has to withstand the extreme thermal loads during re-entry which will induce a maximum temperature up to 1750 °C on the surface of the cap. Thus, the shell of the cap system is designed and manufactured using DLR's C/C-SiC material which is a special kind of carbon based ceramic matrix composite (CMC) material produced via the in house liquid silicon infiltration process of DLR. This material has demonstrated its good temperature resistance during FOTON and EXPRESS re-entry capsule missions. Besides the design and manufacturing of the nose cap system, the qualification approach was an important effort of the development work. Missing a test facility which is able to simulate all loading conditions from lift off to re-entry and landing, is was necessary to separate the loads and to use different test facilities. Considering the limitations of the facilities, the budget and time constraints, an optimized test philosophy has been established. The goal was to use a full scale qualification unit including all TPS components of the nose area for most of the tests. These were the simulation of ascent loads given by the shuttle requirements and descent loads

Twistor space, Minkowski space and the conformal group

International Nuclear Information System (INIS)

Broek, P.M. van den

1983-01-01

It is shown that the conformal group of compactified Minkowski space is isomorphic to a group of rays of semilinear transformations of twistor space. The action of the conformal group on twistor space is given by an explicit realisation of this isomorphism. In this way we determine the transformation of twistor space under space inversion and time inversion. (orig.)

Proximity and Force Characteristics of CMC Touch Sensor with Square/Dome-shaped Sensor Elements

International Nuclear Information System (INIS)

Kawamura, T; Inaguma, N; Kakizaki, Y; Yamada, H; Tani, K

2013-01-01

A tactile sensor called Carbon Micro Coil (CMC) touch sensor was developed by CMC Technology Development Co., Ltd. The sensor's elements used in the experiments of this paper are made of silicon rubber containing CMCs several micrometers in diameter. One of the elements is molded into a square 30 mm on a side and 3 mm thick; the other is a dome 16 mm in diameter and 2 mm height. CMCs in the sensor element contribute to the electrical conductivity and the sensor element is considered to constitute an LCR circuit. When an object approaches to the sensor element or the sensor element is deformed mechanically, the impedance changes, and the CMC sensor detects the impedance changes by measuring the modulation of amplitude and phase of an input excitation signal to the sensor element. The CMC sensor also creates voltage signals of the R- and LC-components separately according to the amplitude and phase modulation. In this paper, the characteristics of the CMC sensor with respect to its proximity and force senses are investigated. First, the output of the CMC sensor with the square-shaped sensor element is measured when an object approaches to the sensor element. Next, the output of the CMC sensor with the dome-shaped sensor element is measured when fine deformations of 1 to 5 μm are applied to the sensor element under variable compression force. The results suggest that the CMC sensor can measure the force variance applied to the sensor element as well as the distance between the sensor element and an object.

Preparation of crosslinked carboxymethylcellulose (CMC) by {sup 60} Co γ-ray irradiation and its biodegradable properties

Energy Technology Data Exchange (ETDEWEB)

Lim, Youn Mook; Lee, Joon Ho; Nho, Young Chang [Radiation Research Center for Industry and Environment, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Son, Tae Il [Dept. of Biotechnology, College of Industrial Science, Graduate School, Chung Ang University, Seoul (Korea, Republic of)

2007-05-15

Biodegradable and biocompatible carboxymethylcellulose (CMC) hydrogels for personal care products such as infants diapers and feminine hygiene products were prepared by a γ- irradiation crosslinking technique. Hydrogels were prepared as a function of the CMC concentration, total dose, and degree of substitution (DS), and their physical properties such as the gel fraction, swelling ratio, pH-responsibility and biodegradability were investigated. The irradiation of an aqueous CMC solution led to a gelation in an aqueous solution of more than 10 w%, and the gel percent increased as the CMC concentration, total dose and DS increased. The equilibrium swelling behaviors of the hydrogels prepared in various conditions were examined in an aqueous solution, and the pH-response at a pH of 1.2 and 6.8 was investigated. CMC hydrogels showed a high gelation at a high CMC concentration with DS 1.2. Lastly, the effects of the crosslinking degree of the CMC on the hydrolysis reaction were examined by cellulase from Trichoderma reseei. It was found that the degradable reaction depended on the degree of the crosslinking of the CMC. Intermolecular crosslinking reactions were confirmed by the ESR spectra.

CHARACTERIZATION OF CARBOXY METHYL CELLULOSE (CMC FROM Eichornia crassipes (Mart Solms

Directory of Open Access Journals (Sweden)

Arum Wijayani

2010-06-01

Full Text Available Carboxy Methyl Cellulose (CMC, a compound made made of eceng gondok has been implied for its characteristic by a constructive wet system, with media such as methanol, propanol and water. Four consecutive phases involving alkalization, carboxymethylization, neutralization and drainage were used in the making process of CMC. The first two process were prepared by reacting NaOH and ClCH2COONa with NaOH 22; 32.5; 39.2; 45.9 g and 20; 26; 32; 38 g ClCH2COONa respectively. Added acetic acid was used in the neutralization process, whilst drainage only involved heating in the oven. The overall result for each characteristic substitution degree, acidity; viscosity; contens of water consentration of NaCl and purity 0.4 - 0.85, 6.10 - 8.49, 3 - 10 cP, 3.57 - 19.4 %, 12.9 - 22.4 % and 77.96 - 87.09 % respectively. Based on the obtained characteristic, could be concluded that CMC is considered as a technical quality and can also be used as filler constituent in adhesive. Keywords: CMC, alkalization, carboxymethylization

Statistical applications for chemistry, manufacturing and controls (CMC) in the pharmaceutical industry

CERN Document Server

Burdick, Richard K; Pfahler, Lori B; Quiroz, Jorge; Sidor, Leslie; Vukovinsky, Kimberly; Zhang, Lanju

2017-01-01

This book examines statistical techniques that are critically important to Chemistry, Manufacturing, and Control (CMC) activities. Statistical methods are presented with a focus on applications unique to the CMC in the pharmaceutical industry. The target audience consists of statisticians and other scientists who are responsible for performing statistical analyses within a CMC environment. Basic statistical concepts are addressed in Chapter 2 followed by applications to specific topics related to development and manufacturing. The mathematical level assumes an elementary understanding of statistical methods. The ability to use Excel or statistical packages such as Minitab, JMP, SAS, or R will provide more value to the reader. The motivation for this book came from an American Association of Pharmaceutical Scientists (AAPS) short course on statistical methods applied to CMC applications presented by four of the authors. One of the course participants asked us for a good reference book, and the only book recomm...

CMC vane assembly apparatus and method

Science.gov (United States)

Schiavo, Anthony L; Gonzalez, Malberto F; Huang, Kuangwei; Radonovich, David C

2012-10-23

A metal vane core or strut (64) is formed integrally with an outer backing plate (40). An inner backing plate (38) is formed separately. A spring (74) with holes (75) is installed in a peripheral spring chamber (76) on the strut. Inner and outer CMC shroud covers (46, 48) are formed, cured, then attached to facing surfaces of the inner and outer backing plates (38, 40). A CMC vane airfoil (22) is formed, cured, and slid over the strut (64). The spring (74) urges continuous contact between the strut (64) and airfoil (66), eliminating vibrations while allowing differential expansion. The inner end (88) of the strut is fastened to the inner backing plate (38). A cooling channel (68) in the strut is connected by holes (69) along the leading edge of the strut to peripheral cooling paths (70, 71) around the strut. Coolant flows through and around the strut, including through the spring holes.

Twistor space, Minkowski space and the conformal group

NARCIS (Netherlands)

van den Broek, P.M.

1983-01-01

It is shown that the conformal group of compactified Minkowski space is isomorphic to a group of rays of semilinear transformations of twistor space. The action of the conformal group on twistor space is given by an explicit realisation of this isomorphism. In this way we determine the

The dynamic magnetoviscoelastic properties of biomineralized (Fe3O4) PVP-CMC hydrogel

Science.gov (United States)

Ray, Ayan; Saha, Nabanita; Saha, Petr

2017-05-01

The Polyvinylpyrrolidone (PVP) and carboxymethylcellulose (CMC) based polymer matrix was used as a template for the preparation of magnetic hydrogel. This freshly prepared PVP-CMC hydrogel template was successfully mineralized by in situ synthesis of magnetic nanoparticles (Fe3O4) via chemical co-precipitation reaction using liquid diffusion method. The present study emphasizes on the rheological behavior of non-mineralized and mineralized PVP-CMC hydrogels. Scanning Electron Microscopy (SEM), transmission electron microscopy (TEM), X-ray Diffraction (XRD) pattern, Fourier transform infrared spectroscopy (FT-TR), Vibrating sample magnetometer (VSM) and dynamic magneto rheometer were used to study the morphological, physical, chemical and magnetic properties of nanoparticle (Fe3O4) filled PVP-CMC hydrogel respectively in order to monitor how Fe3O4 magnetic nanoparticles affects the mechanical properties of the hydrogel network. The storage (G') and loss (G") moduli with a complex viscosity of the system was measured using a parallel plate rheometer. Frequency and amplitude sweep with temperature variation was performed to determine the frequency and amplitude dependent magneto viscoelastic moduli for both hydrogel samples. A strong shear thinning effect was observed in both (non-mineralized and mineralized) PVP-CMC hydrogels, which confirm that Fe3O4 filled magnetic hydrogels, are pseudoplastic in nature. This Fe3O4 filled PVP-CMC hydrogel can be considered as stimuli-responsive soft matter that may be used as an actuator in medical devices.

NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 38: Computer Mediated Communication (CMC) and the communication of technical information in aerospace

Science.gov (United States)

Murphy, Daniel J.; Pinelli, Thomas E.

1994-01-01

This paper discusses the use of computers as a medium for communication (CMC) used by aerospace engineers and scientists to obtain and/or provide technical information related to research and development activities. The data were obtained from a questionnaire survey that yielded 1006 mail responses. In addition to communication media, the research also investigates degrees of task uncertainty, environmental complexity, and other relevant variables that can affect aerospace workers' information-seeking strategies. While findings indicate that many individuals report CMC is an important function in their communication patterns, the research indicates that CMC is used less often and deemed less valuable than other more conventional media, such as paper documents, group meetings, telephone and face-to-face conversations. Fewer than one third of the individuals in the survey account for nearly eighty percent of the reported CMC use, and another twenty percent indicate they do not use the medium at all, its availability notwithstanding. These preliminary findings suggest that CMC is not as pervasive a communication medium among aerospace workers as the researcher expect a priori. The reasons underlying the reported media use are not yet fully known, and this suggests that continuing research in this area may be valuable.

Optimization of formulation of cmc-na, xanthan gum and carrageenan affecting the physicochemical properties of papaya-wolfberry beverage using response surface methodology

International Nuclear Information System (INIS)

Geo, J.Z.H.; Zong, G.L.P.

2013-01-01

CMC-Na, xanthan gum and carrageenan are widely employed in food industry. They were used for its thickening properties of aqueous solutions or emulsifying abilities. The present work aims to optimize the formula of the three stabilizers in the process of papaya-wolfberry beverage by response surface methodology (RSM). The results showed that the models were significantly (p<0.05) fitted for describing the viscosity and cloudiness of papaya-wolfberry beverage. The results also indicated that the linear terms of CMC-Na and xanthan gum were the most significant (p<0.05) variables affecting the viscosity, while xanthan gum and carrageenan were the most significant (p<0.05) variable affecting the cloudiness. The interaction of CMC-Na and xanthan gum behaved extremely significant for viscosity. From the optimization procedure, the best formula for viscosity was obtained at the combined level of 0.0652% (w/w) CMC-Na, 0.1070% (w/w) xanthan gum and 0.1485% (w/w) carrageenan, and the other group of 0.0623% (w/w) CMC-Na, 0.1375% (w/w) xanthan gum and 0.1461% (w/w) carrageenan for cloudiness. The results of our study would be used to improve the quality of papaya-wolfberry beverage and increase its economic efficiency. (author)

Study of induced cross-linking by ionizing radiation of polyvinylpyrrolidone (PVP)/carboxymethylcellulose (CMC)

International Nuclear Information System (INIS)

Alcantara, Mara T.S.; Chirinos, Hugo; Amaral, Renata H.; Rogero, Sizue O.; Lugao, Ademar B.

2005-01-01

The polymeric hydrogels are materials with capacity to absorb great amount of water. They present interesting characteristics for many applications in the industry and as biomaterials. The hydrogel membrane with PVP, poly ethylene glycol and agar, crosslinked and sterilized simultaneously by radiation was introduced in the European market and now it is reaching other regions. In this work the hydrogel studied was synthesized with PVP and CMC and crosslinked by gamma radiation. It was applied factorial planning methodology using the gel fraction as basic parameter. Antagonistic interaction was observed between PVP and CMC. High concentrations of PVP help the crosslinking and the opposite with CMC. On the other hand, for low concentrations of PVP the dose influences considerable the gel fraction what it does not happen for high concentrations. From these results it was made an analysis of response surface allowing the optimization of the concentrations of the variables PVP and CMC. (author)

Non-CMC Solutions of the Einstein Constraint Equations on Compact Manifolds with Apparent Horizon Boundaries

Science.gov (United States)

Holst, Michael; Meier, Caleb; Tsogtgerel, G.

2018-01-01

In this article we continue our effort to do a systematic development of the solution theory for conformal formulations of the Einstein constraint equations on compact manifolds with boundary. By building in a natural way on our recent work in Holst and Tsogtgerel (Class Quantum Gravity 30:205011, 2013), and Holst et al. (Phys Rev Lett 100(16):161101, 2008, Commun Math Phys 288(2):547-613, 2009), and also on the work of Maxwell (J Hyperbolic Differ Eqs 2(2):521-546, 2005a, Commun Math Phys 253(3):561-583, 2005b, Math Res Lett 16(4):627-645, 2009) and Dain (Class Quantum Gravity 21(2):555-573, 2004), under reasonable assumptions on the data we prove existence of both near- and far-from-constant mean curvature (CMC) solutions for a class of Robin boundary conditions commonly used in the literature for modeling black holes, with a third existence result for CMC appearing as a special case. Dain and Maxwell addressed initial data engineering for space-times that evolve to contain black holes, determining solutions to the conformal formulation on an asymptotically Euclidean manifold in the CMC setting, with interior boundary conditions representing excised interior black hole regions. Holst and Tsogtgerel compiled the interior boundary results covered by Dain and Maxwell, and then developed general interior conditions to model the apparent horizon boundary conditions of Dainand Maxwell for compact manifolds with boundary, and subsequently proved existence of solutions to the Lichnerowicz equation on compact manifolds with such boundary conditions. This paper picks up where Holst and Tsogtgerel left off, addressing the general non-CMC case for compact manifolds with boundary. As in our previous articles, our focus here is again on low regularity data and on the interaction between different types of boundary conditions. While our work here serves primarily to extend the solution theory for the compact with boundary case, we also develop several technical tools that have

Peer Evaluation in CMC Learning Environment and Writing Skill

Directory of Open Access Journals (Sweden)

Morteza Mellati

2014-09-01

Full Text Available Peer evaluation and technology-based instruction as the various domains of language teaching perspectives might affect language development. Group work in a technology-based environment might be more successful when learners are involved in developing the assessment process particularly peer assessment. This study investigated the effectiveness of peer evaluation in technology-based language environment and its effects on English writing ability. To reach this goal, 70 Iranian learners were participated in English language writing context. They were divided into two groups, one group assigned to CMC (Computer-Mediated Communication language learning context and the other assigned to a traditional learning environment. Both groups were encouraged to evaluate their classmates’ writing tasks. In addition, interviews were conducted with two learners. Comparing these two groups provides comprehensive guidelines for teachers as well as curriculum designers to set adjusted writing language environment for more effective and creative language teaching and learning. E-collaboration classroom tasks have high intrinsic motivation as well as significant effects on learners’ outcomes. Cooperative tasks specifically in technology-based environment lead learners to group working and consequently group learning. Computer-Mediated Communication is meaningful, especially in contexts in which teachers stimulate group work activities.

Exploring the usefulness of comprehensive care plans for children with medical complexity (CMC: a qualitative study

Directory of Open Access Journals (Sweden)

Adams Sherri

2013-01-01

Full Text Available Abstract Background The Medical Home model recommends that Children with Special Health Care Needs (CSHCN receive a medical care plan, outlining the child’s major medical issues and care needs to assist with care coordination. While care plans are a primary component of effective care coordination, the creation and maintenance of care plans is time, labor, and cost intensive, and the desired content of the care plan has not been studied. The purpose of this qualitative study was to understand the usefulness and desired content of comprehensive care plans by exploring the perceptions of parents and health care providers (HCPs of children with medical complexity (CMC. Methods This qualitative study utilized in-depth semi-structured interviews and focus groups. HCPs (n = 15 and parents (n = 15 of CMC who had all used a comprehensive care plan were recruited from a tertiary pediatric academic health sciences center. Themes were identified through grounded theory analysis of interview and focus group data. Results A multi-dimensional model of perceived care plan usefulness emerged. The model highlights three integral aspects of the care plan: care plan characteristics, activating factors and perceived outcomes of using a care plan. Care plans were perceived as a useful tool that centralized and focused the care of the child. Care plans were reported to flatten the hierarchical relationship between HCPs and parents, resulting in enhanced reciprocal information exchange and strengthened relationships. Participants expressed that a standardized template that is family-centered and includes content relevant to both the medical and social needs of the child is beneficial when integrated into overall care planning and delivery for CMC. Conclusions Care plans are perceived to be a useful tool to both health care providers and parents of CMC. These findings inform the utility and development of a comprehensive care plan template as well as a model of how

Computer-Mediated Communication (CMC) in L2 Oral Proficiency Development: A Meta-Analysis

Science.gov (United States)

Lin, Huifen

2015-01-01

The ever growing interest in the development of foreign or second (L2) oral proficiency in a computer-mediated communication (CMC) classroom has resulted in a large body of studies looking at both the direct and indirect effects of CMC interventions on the acquisition of oral competences. The present study employed a quantitative meta-analytic…

Study on novel functional materials carboxymethyl cellulose lithium (CMC-Li) improve high-performance lithium-ion battery.

Science.gov (United States)

Qiu, Lei; Shao, Ziqiang; Xiang, Pan; Wang, Daxiong; Zhou, Zhenwen; Wang, Feijun; Wang, Wenjun; Wang, Jianquan

2014-09-22

Novel cellulose derivative CMC-Li was synthesized by cotton as raw material. The mechanism of the CMC-Li modified electrode materials by electrospinning was reported. CMC-Li/lithium iron phosphate (LiFePO4, LFP) composite fiber coated with LFP and CMC-Li nanofibers was successfully obtained by electrospinning. Then, CMC-Li/LFP nano-composite fiber was carbonized under nitrogen at a high temperature formed CNF/LFP/Li (CLL) composite nanofibers as cathode material. It can increase the contents of Li+, and improving the diffusion efficiency and specific capacity. The battery with CLL as cathode material retained close to 100% of initial reversible capacity after 200 cycles at 168 mAh g(-1), which was nearly the theoretical specific capacity of LFP. The cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD) and scanning electron microscope (SEM) were characterizing material performance. The batteries have good electrochemical property, outstanding pollution-free, excellent stability. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of a Hydrogen Uptake-Release Mg-Based Alloy by Adding a Polymer CMC (Carboxymethylcellulose, Sodium Salt) via Reaction-Accompanying Milling

Science.gov (United States)

Kwak, Young Jun; Choi, Eunho; Song, Myoung Youp

2018-03-01

The addition of carboxymethylcellulose, sodium salt (CMC) might improve the hydrogen uptake and release properties of Mg since it has a relatively low melting point and the melting of CMC during milling in hydrogen (reaction-accompanying milling) may make the milled samples be in good states to absorb and release hydrogen rapidly and to have a large hydrogen-storage capacity. Samples with compositions of 95 w/o Mg + 5 w/o CMC (named Mg-5CMC) and 90 w/o Mg + 10 w/o CMC (named Mg-10CMC) were prepared by adding CMC via reaction-accompanying milling. Activation of Mg-10CMC was completed after about 3 hydrogen uptake-release cycles. Mg-10CMC had a higher initial hydrogen uptake rate and a larger amount of hydrogen absorbed in 60 min, U (60 min), than Mg-5CMC before and after activation. At the cycle number of three (CN = 3), Mg-10CMC had a very high initial hydrogen uptake rate (1.56 w/o H/min) and a large U (60 min) (5.57 w/o H) at 593 K in hydrogen of 12 bar, showing that the activated Mg-10CMC has an effective hydrogen-storage capacity of about 5.6 w/o at 593 K in hydrogen of 12 bar at CN = 3. At CN = 2, Mg-10CMC released 1.00 w/o H in 2.5 min, 4.67 w/o H in 10 min, and 4.76 w/o H in 60 min at 648 K in hydrogen of 1.0 bar. The milling in hydrogen of Mg with CMC is believed to generate imperfections and cracks and reduce the particle size. The addition of 10 w/o CMC was more effective on the initial hydrogen uptake rate and U (60 min) compared with the 10 w/o additions of NbF5, TaF5, Fe2O3, and MnO, and the 10 w/o simultaneous addition of Ni, Fe, and Ti. To the best of our knowledge, this study is the first in which a polymer CMC is added to Mg by reaction-accompanying milling to improve the hydrogen storage properties of Mg.

Cyber Space and Digital Democracy in South Korea

Science.gov (United States)

Lee, Jin Ro

2017-03-01

Korea is a very interesting case. Korea shows rapid growth of the Internet users, and largertrade surplus in telecommunication industry with the help of government’s successful information technology policy. And Koreans also made their country more democratic with active participation. This paper analyzed the growth of the Internet and SNS in South Korea. The Internet and SNS created cyber space. They have several advantages as an effective means of communication. Cyber space is influenced by three subjects such as the government [state], the market [capital], and citizens [people]. There are two research questions. First question is how the Korean CMC industry can grow fast after its birth. Three main subjects were dealt with in this research. They are the State, the Market, and the Citizen. I divided the history of Korean CMC industry into three periods. The first formation stage is from the birth of CMC in Korea between from 1980 and1990. The government initiated the monopolistic CMC market. Several conglomerates participated to co-operate the government. But the users are very small. The second growthstage is between from 1990 to 1995. The government also deregulated the Market with changing policy from ‘appointment’ to ‘registration’. The companies increased investment for the possibility of wide diffusion of CMC use. The third prosperity stage is between 1995 and 2010. The government promoted the CMC market’s competition with ‘notice’ policy. And citizens actively enjoy and apply CMC services. However, the fourth shift stage to smart phone faced several problems such as less democracy and one way communication which will weaken the creativity of the content. Second question is what the roles of three subjects are. I examined the cyber space by the uses of digital media with three subjects. Even though the state and the market have limits to promote democracy, the citizens are expected to make the digital society moredemocratic. If the state

Oxide_Oxide Ceramic Matrix Composite (CMC) Exhaust Mixer Development in the NASA Environmentally Responsible Aviation (ERA) Project

Science.gov (United States)

Kiser, J. Douglas; Bansal, Narottam P.; Szelagowski, James; Sokhey, Jagdish; Heffernan, Tab; Clegg, Joseph; Pierluissi, Anthony; Riedell, Jim; Wyen, Travis; Atmur, Steven;

Improvement of Fish Sauce Quality by Strain CMC5-3-1: A Novel Species of Staphylococcus sp.

Science.gov (United States)

Udomsil, Natteewan; Rodtong, Sureelak; Tanasupawat, Somboon; Yongsawatdigul, Jirawat

2015-09-01

Staphylococcus sp. CMC5-3-1 and CMS5-7-5 isolated from fermented fish sauce at 3 to 7 mo, respectively, showed different characteristics on protein hydrolysis and volatile formation. These Gram-positive cocci were able to grow in up to 15% NaCl with the optimum at 0.5% to 5% NaCl in tryptic soy broth. Based on ribosomal 16S rRNA gene sequences, Staphylococcus sp. CMC5-3-1 and CMS5-7-5 showed 99.0% similarity to that of Staphylococcus piscifermentans JCM 6057(T) , but DNA-DNA relatedness was sauce inoculated with Staphylococcus sp. CMC5-3-1 was 740.5 mM, which was higher than that inoculated by the strain CMS5-7-5 (662.14 mM, P sauce inoculated with Staphylococcus sp. CMC5-3-1 showed the highest content of total glutamic acid (P sauce inoculated with Staphylococcus sp. CMC5-3-1 was 2-methypropanal, contributing to the desirable dark chocolate note. Staphylococcus sp. CMC5-3-1 could be applied as a starter culture to improve the umami and aroma of fish sauce. © 2015 Institute of Food Technologists®

A qualitative study of health care providers' perceptions and experiences of working together to care for children with medical complexity (CMC).

Science.gov (United States)

Altman, Lisa; Zurynski, Yvonne; Breen, Christie; Hoffmann, Tim; Woolfenden, Susan

2018-01-31

Children with medical complexity (CMC) have a wide range of long term health problems and disabilities that have an adverse impact on their quality of life. They have high levels of family identified health care needs and health care utilisation. There is no Australian literature on the experiences of health care providers working in the Australian tertiary, secondary and primary health care system, whilst managing CMC. This information is essential to inform the design of integrated health care systems for these children. We address this knowledge gap by exploring the perceptions and experiences of health care providers on the provision of health care for CMC aged 0 to 18 years. A qualitative research study was undertaken. Stakeholder forums, group and individual in depth interviews were undertaken using a semi-structured interview guide. The stakeholder forums were audio recorded and transcribed verbatim. Field notes of the stakeholder forums, group and individual interviews were taken. Inductive thematic analysis was undertaken to identify key themes. One hundred and three providers took part in the stakeholder forums and interviews across 3 local health districts, a tertiary paediatric hospital network, and primary health care organisations. Providers expressed concern regarding family capacity to negotiate the system, which was impacted by the medical complexity of the children and psychosocial complexity of their families. Lack of health care provider capacity in terms of their skills, time and availability to manage CMC was also a key problem. These issues occurred within a health system that had impaired capacity in terms of fragmentation of care and limited communication among health care providers. When designing integrated care models for CMC, it is essential to understand and address the challenges experienced by their health care providers. This requires adequate training of providers, additional resources and time for coordination of care, improved

Overview of CMC (Ceramic Matrix Composite) Research at the NASA Glenn Research Center

Science.gov (United States)

Kiser, J. Douglas; Grady, Joseph E.; Bhatt, Ramakrishna T.; Wiesner, Valerie L.; Zhu, Dongming

2016-01-01

In support of NASAs Aeronautics Research Mission, the Glenn Research Center has developed and assessed various constituents for a high temperature (2700F) SiCSiC CMC system for turbine engine applications. Combinations of highly creep-resistant SiC fibers, advanced 3D weaves, durable environmental barrier coatings (EBCs), and a 2700F-capable hybrid SiC matrix are being developed evaluated. The resulting improvements in CMC mechanical properties and durability will be summarized. The development and validation of models for predicting the effects of the environment on the durability of CMCs and EBCs and other operating-environment challenges including the effect of CMAS (calcium magnesium aluminosilicate) degradation of EBCs will be discussed. Progress toward the development of CMC joining technology for 2400F joint applications will also be reviewed.

Turbine Airfoil With CMC Leading-Edge Concept Tested Under Simulated Gas Turbine Conditions

Science.gov (United States)

Robinson, R. Craig; Hatton, Kenneth S.

2000-01-01

Silicon-based ceramics have been proposed as component materials for gas turbine engine hot-sections. When the Navy s Harrier fighter experienced engine (Pegasus F402) failure because of leading-edge durability problems on the second-stage high-pressure turbine vane, the Office of Naval Research came to the NASA Glenn Research Center at Lewis Field for test support in evaluating a concept for eliminating the vane-edge degradation. The High Pressure Burner Rig (HPBR) was selected for testing since it could provide temperature, pressure, velocity, and combustion gas compositions that closely simulate the engine environment. The study focused on equipping the stationary metal airfoil (Pegasus F402) with a ceramic matrix composite (CMC) leading-edge insert and evaluating the feasibility and benefits of such a configuration. The test exposed the component, with and without the CMC insert, to the harsh engine environment in an unloaded condition, with cooling to provide temperature relief to the metal blade underneath. The insert was made using an AlliedSignal Composites, Inc., enhanced HiNicalon (Nippon Carbon Co. LTD., Yokohama, Japan) fiber-reinforced silicon carbide composite (SiC/SiC CMC) material fabricated via chemical vapor infiltration. This insert was 45-mils thick and occupied a recessed area in the leading edge and shroud of the vane. It was designed to be free floating with an end cap design. The HPBR tests provided a comparative evaluation of the temperature response and leading-edge durability and included cycling the airfoils between simulated idle, lift, and cruise flight conditions. In addition, the airfoils were aircooled, uniquely instrumented, and exposed to the exact set of internal and external conditions, which included gas temperatures in excess of 1370 C (2500 F). In addition to documenting the temperature response of the metal vane for comparison with the CMC, a demonstration of improved leading-edge durability was a primary goal. First, the

It's Just a Game, Right? Types of Play in Foreign Language CMC

OpenAIRE

Chantelle N. Warner

2004-01-01

This study focuses on the various playful uses of language that occurred during a semester-long study of two German language courses using one type of synchronous network-based medium, the MOO. Research and use of synchronous computer-mediated communication (CMC) have flourished in the study of second-language acquisition (SLA) since the late 1990s; however, the primary focus has been on the potential benefits of using CMC to increase the amount of communication (Beauvois, 1997; Kern, 1995; W...

Simple derivation of magnetic space groups

International Nuclear Information System (INIS)

Bertaut, E.F.; CEA Centre d'Etudes Nucleaires de Grenoble, 38

1975-01-01

The magnetic translation lattices can be described by invariant wave vectors k. Advantages of the wave vector notation over the notations used by Belov et al. and Opechowski et al. are pointed out. In a one-dimensional real representation a space group element (α/tau(1)) has either the character +1 (symmetry element) or -1 (antisymmetry element). Thus the square of any space group operation must have the character +1 in a one-dimensional real representation. This simple ''square criterion'' is used to limit the admissible k-vectors and to derive the family of magnetic space groups, i.e. the set of all possible magnetic space groups, belonging to the same crystallographic space group. In the discussion some useful side results are obtained. Not only the real one-dimensional representations of point groups are connected to real one-dimensional representations of space groups, but a direct connection is shown to exist between one-dimensional complex representations of the point groups 3, 4 and 6 and one-dimensional real representations, belonging to P[001/2]=Psub(2c)(Psub(c))-lattices with screw axes 3 1 , 3 2 , 4 2 , 6 2 and 6 4 . Rules are derived for finding the Belov symbol when the Opechowski-Guccione symbol of the magnetic space group is known and this opportunity is used for correcting errors in the Opechowski-Guccione tables [fr

Ni(0-CMC-Na Nickel Colloids in Sodium Carboxymethyl-Cellulose: Catalytic Evaluation in Hydrogenation Reactions

Directory of Open Access Journals (Sweden)

Abdallah Karim

2011-01-01

Full Text Available A recyclable catalyst, Ni(0-CMC-Na, composed of nickel colloids dispersed in a water soluble bioorganic polymer, sodium carboxymethylcellulose (CMC-Na, was synthesized by a simple procedure from readily available reagents. The catalyst thus obtained is stable and highly active in alkene hydrogenations.

Microwave assisted in situ synthesis of Ag–NaCMC films and their reproducible surface-enhanced Raman scattering signals

International Nuclear Information System (INIS)

Jiang, Tao; Li, Junpeng; Zhang, Li; Wang, Binbing; Zhou, Jun

2014-01-01

Graphical abstract: Two kinds of Ag–NaCMC films for surface-enhanced Raman scattering (SERS) were prepared by conventional heating and microwave assisted in situ reduction methods without any additional capping or reducing agents. A relatively narrow and symmetric surface plasmon resonance band was observed in the absorption spectra of the films fabricated by the microwave assisted in situ reduction method. More uniform silver nanoparticles (NPs) implied by the symmetric absorption spectrum were further confirmed by the scanning electron microscopy images. After the simulation of the E-field intensity distribution around the silver NPs in NaCMC film, the Raman scattering enhancement factors (EFs) of these films were then investigated with 4-mercaptobenzoic acid molecule as a SERS reporter. Improved reproducibility of SERS signal was obtained in the microwave assisted synthesized Ag–NaCMC film, although it maintained an EF as only 1.11 × 10 8 . The reproducible SERS signal of the Ag–NaCMC film is particularly attractive and this microwave assisted in situ reduction method is suitable for the production of excellent substrate for biosensor application. - Highlights: • The synthesis of Ag–NaCMC films was successfully fulfilled by a low-cost microwave method. • More uniform silver nanoparticles were observed in Ag–NaCMC film synthesized by microwave. • Improved reproducibility of SERS signal was obtained in microwave synthesized Ag–NaCMC film. - Abstract: Two kinds of Ag–NaCMC films for surface-enhanced Raman scattering (SERS) were prepared by conventional heating and microwave assisted in situ reduction methods without any additional capping or reducing agents. A relatively narrow and symmetric surface plasmon resonance band was observed in the absorption spectra of the films fabricated by the microwave assisted in situ reduction method. More uniform silver nanoparticles (NPs) implied by the symmetric absorption spectrum were further confirmed by

Carboxymethyl Cellulose (CMC) from Oil Palm Empty Fruit Bunch (OPEFB) in the new solvent Dimethyl Sulfoxide (DMSO)/Tetrabutylammonium Fluoride (TBAF)

Science.gov (United States)

Eliza, M. Y.; Shahruddin, M.; Noormaziah, J.; Rosli, W. D. Wan

2015-06-01

The surplus of Oil Palm is the most galore wastes in Malaysia because it produced about half of the world palm oil production, which contributes a major disposal problem Synthesis from an empty fruit bunch produced products such as Carboxymethyl Cellulose (CMC), could apply in diverse application such as for paper coating, food packaging and most recently, the potential as biomaterials has been revealed. In this study, CMC was prepared by firstly dissolved the bleached pulp from OPEFB in mixture solution of dimethyl sulfoxide(DMSO)/tetrabutylammonium fluoride (TBAF) without any prior chemical modification. It took only 30 minutes to fully dissolve at temperature 60°C before sodium hydroxide (NaOH) were added for activation and monochloroacetateas terrifying agent. The final product is appeared in white powder, which is then will be analyzedby FTIR analysis. FTIR results show peaks appeared at wavenumber between 1609 cm-1 to 1614 cm-1 proved the existence of carboxymethyl groups which substitute OH groups at anhydroglucose(AGU) unit. As a conclusion, mixture solution of DMSO/TBAF is the suitable solvent used for dissolved cellulose before modifying it into CMC with higher Degree of Substitution (DS). Furthermore, the dissolution of the OPEFB bleached pulp was easy, simple and at a faster rate without prior chemical modification at temperature as low as 60°C.

Effect of CMC and arabic gum in the manufacture of jackfruit velva (Artocarpus heterophyllus)

Science.gov (United States)

Yudhistira, B.; Riyadi, N. H.; Pangestika, A. D.; Pertiwi, S. R.

2018-03-01

Velva is one type of frozen dessert which is made from fruit/vegetable with ice cream maker, low fat and high fiber content. Jackfruit is a raw material for the manufacture of velva because of the high fiber content of 2.31 gr. The use of a stabilizers combination of CMC and arabic gum in the manufacture of velva will provide a better gel mix than single use. The purpose of this research is to know the influence of variation of CMC and arabic gum stabilizer on the characteristics (physical, chemical, and sensory) of jackfruit velva (Artocarpus heterophyllus) and determine variations in the most appropriate combinations of stabilizers to produce jackfruit velva with the best quality. This research applied Completely Randomized Design consist of one factor which is the combination of CMC and arabic gum levels in the making of jackfruit velva with two replicates and two replications of the analysis. The data obtained then analyzed statistically using one way analysis of variance (ANOVA), when there is a significant difference, then followed by Duncan’s Multiple Range Test (DMRT) at significance level of 0.05. The results of this study concluded that the jackfruit velva with the addition of various concentrations of CMC and arabic gum is significantly affecting the taste, texture and overall parameters, but no significant difference on the color and flavor parameters of jackfruit velva. Based on the results of physical characteristics, chemical and sensory jackfruit velva with the addition of a stabilizing concentration of CMC and arabic gum 1: 1 result in best jackfruit velva. The best jackfruit velva with stabilizing the concentration of CMC and arabic gum 1: 1 contains a water content of 61.95%, dietary fiber 2.231%, total dissolved solids 20.38 °Brix, overrun 19.709%, meltdown 28.215 minutes. As for the color attribute score 3.72; Taste 4; flavor 3.60; Texture 3.68, and overall 3.88.

Space groups for solid state scientists

CERN Document Server

Glazer, Michael; Glazer, Alexander N

2014-01-01

This Second Edition provides solid state scientists, who are not necessarily experts in crystallography, with an understandable and comprehensive guide to the new International Tables for Crystallography. The basic ideas of symmetry, lattices, point groups, and space groups are explained in a clear and detailed manner. Notation is introduced in a step-by-step way so that the reader is supplied with the tools necessary to derive and apply space group information. Of particular interest in this second edition are the discussions of space groups application to such timely topics as high-te

CMC-coated Fe3O4 nanoparticles as new MRI probes for hepatocellular carcinoma

International Nuclear Information System (INIS)

Sitthichai, Sudarat; Pilapong, Chalermchai; Thongtem, Titipun; Thongtem, Somchai

2015-01-01

Highlights: • Fe 3 O 4 nanoparticles (NPs) are superparamagnetic. • CMC is water-soluble and nontoxic cellulose-derivative polymer. • CMC-coated Fe 3 O 4 NPs were successfully prepared by co-precipitation method. • The promising NPs that can be used for magnetic resonance imaging application. - Abstract: Pure Fe 3 O 4 nanoparticles and Fe 3 O 4 magnetic nanoparticles (MNPs) coated with carboxymethyl cellulose (CMC) were successfully prepared by co-precipitating of FeCl 2 ·4H 2 O and FeCl 3 ·6H 2 O in the solutions containing ammonia at 80 °C for 3 h. Phase, morphology, particle-sized distribution, surface chemistry, and weight loss were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) including high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED), thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR) spectroscopy. In this research, CMC-coated Fe 3 O 4 MNPs consisting of Fe 2+ and Fe 3+ ions with 543.3-mM −1 s −1 high relaxivity were detected and were able to be used for magnetic resonance imaging (MRI) application with very good contrast for targeting hepatocellular carcinoma (HCC) without any further vectorization.

Influence of PVA and CMC on the Properties of Pigment Coating Colors and their Effects on Curtain Stability

Directory of Open Access Journals (Sweden)

Eun Heui Choi

2015-09-01

Full Text Available The influence of polyvinyl alcohol (PVA and carboxymethyl cellulose (CMC on the properties of ground calcium carbonate (GCC and clay coating colors, as well as its effect on curtain stability during the coating process was investigated. Based on the experimental results of the zeta potential, sediment porosity, rheological measurements, the floc formation mechanisms of the cobinders were proposed. The zeta potential decreased with an increase in the amount of added PVA, while it barely changed when CMC was added. This was attributed to the adsorption of PVA onto the pigment surface, while the adsorption of CMC was hindered by electrostatic repulsion. CMC cobinder increased the low-shear viscosity, but it resulted in relatively low viscosity under high-shear conditions, indicating the disruption of the formed flocs under high shear. The destabilization mechanism of the curtain coating differed depending on the type of cobinder. The PVA cobinder flocculates the coating color via a gelling mechanism, while the CMC cobinder flocculates the colors via a depletion flocculation mechanism.

Radiation crosslinking of CMC-Na at low dose and its application as substitute for hydrogel

International Nuclear Information System (INIS)

Liu Pengfei; Peng Jing; Li Jiuqiang; Wu Jilan

2005-01-01

The slight radiation-crosslinked CMC-Na as a substitute for hydrogel was prepared by gamma irradiation below gelation dose. The effects of various parameters such as absorbed dose, concentration of inorganic salts, pH, swelling temperature and swelling time on the swelling ratio in water were investigated in detail. This kind of slight crosslinked CMC-Na showed good water absorption below 60 deg. C, whereas, it became solution when heated up to 70 deg. C. Such CMC-Na gel is different from the true gel that is insoluble in boiled water; nevertheless, it can be used as hydrogel at room temperature and produced at low dose. Due to its low cost, it might be useful for its application in agriculture or others

[Preparation of Coated CMC-Fe0 Using Rheological Phase Reaction Method and Research on Degradation of TCE in Water].

Science.gov (United States)

Fan, Wen-jing; Cheng, Yue; Yu, Shu-zhen; Fan, Xiao-feng

2015-06-01

The coated nanoscale zero-valent iron (coated CMC-Fe0) was synthesized with cheap and environment friendly CMC as the coating agent using rheological phase reaction. The sample was characterized by means of XRD, SEM, TEM and N2 adsorption-stripping and used to study reductive dechlorination of TCE. The experimental results indicated that the removal rate of TCE was about 100% when the CMC-Fe0 dosage was 6 g x L(-1), the initial TCE concentration was 5 mg x L(-1) and the reaction time was 40 h. The TCE degradation reaction of coated CMC-Fe0 followed a pseudo-first-order kinetic model. Finally, the product could be simply recovered.

Mapping spaces and automorphism groups of toric noncommutative spaces

Science.gov (United States)

Barnes, Gwendolyn E.; Schenkel, Alexander; Szabo, Richard J.

2017-09-01

We develop a sheaf theory approach to toric noncommutative geometry which allows us to formalize the concept of mapping spaces between two toric noncommutative spaces. As an application, we study the `internalized' automorphism group of a toric noncommutative space and show that its Lie algebra has an elementary description in terms of braided derivations.

Estimation of AOT and SDS CMC in a methanol using conductometry, viscometry and pyrene fluorescence spectroscopy methods

Science.gov (United States)

Mitsionis, Anastasios I.; Vaimakis, Tiverios C.

2012-09-01

Critical micelle concentration (CMC) of two anionic surfactants in methanol was estimated using conductometry, viscometry and pyrene fluorescence spectroscopy methods. The surfactants used, were sodium bis(2-ethylhexyl) sulfosuccinate (Aerosol-OT, AOT) and sodium dodecyl sulfate (SDS) dispersed in pure methanol. The CMC determination was evaluated in room temperature. The results have shown nearly similar concentrations.

Enhanced electrochemical properties of LiFePO4 (LFP) cathode using the carboxymethyl cellulose lithium (CMC-Li) as novel binder in lithium-ion battery.

Science.gov (United States)

Qiu, Lei; Shao, Ziqiang; Wang, Daxiong; Wang, Wenjun; Wang, Feijun; Wang, Jianquan

2014-10-13

Novel water-based binder CMC-Li is synthesized using cotton as raw material. The mechanism of the CMC-Li as a binder is reported. Electrochemical properties of batteries cathodes based on commercially available lithium iron phosphate (LiFePO4, LFP) and CMC-Li as a water-soluble binder are investigated. CMC-Li is a novel lithium-ion binder. Compare with conventional poly(vinylidene fluoride) (PVDF) binder, and the battery with CMC-Li as the binder retained 97.8% of initial reversible capacity after 200 cycles at 176 mAh g(-1), which is beyond the theoretical specific capacity of LFP. Constant current charge-discharge test results demonstrate that the LFP electrode using CMC-Li as the binder has the highest rate capability, follow closely by that using PVDF binder. The batteries have good electrochemical property, outstanding pollution-free and excellent stability. Copyright © 2014 Elsevier Ltd. All rights reserved.

Compact, Lightweight, Ceramic Matrix Composite (CMC) Based Acoustic Liners for Reducing Subsonic Jet Aircraft Engine Noise

Science.gov (United States)

Kiser, J. Douglas; Grady, Joseph E.; Miller, Christopher J.; Hultgren, Lennart S.; Jones, Michael G.

2016-01-01

Recent developments have reduced fan and jet noise contributions to overall subsonic aircraft jet-engine noise. Now, aircraft designers are turning their attention toward reducing engine core noise. The NASA Glenn Research Center and NASA Langley Research Center have teamed to investigate the development of a compact, lightweight acoustic liner based on oxide/oxide ceramic matrix composite (CMC) materials. The NASA team has built upon an existing oxide/oxide CMC sandwich structure concept that provides monotonal noise reduction. Oxide/oxide composites have good high temperature strength and oxidation resistance, which could allow them to perform as core liners at temperatures up to 1000C (1832F), and even higher depending on the selection of the composite constituents. NASA has initiated the evaluation of CMC-based liners that use cells of different lengths (variable-depth channels) or effective lengths to achieve broadband noise reduction. Reducing the overall liner thickness is also a major goal, to minimize the volume occupied by the liner. As a first step toward demonstrating the feasibility of our concepts, an oxide/oxide CMC acoustic testing article with different channel lengths was tested. Our approach, summary of test results, current status, and goals for the future are reported.

The cmc-value of a bolalipid with two phosphocholine headgroups and a C24 alkyl chain: Unusual binding properties of fluorescence probes to bolalipid aggregates.

Science.gov (United States)

Kordts, Martin; Kerth, Andreas; Drescher, Simon; Ott, Maria; Blume, Alfred

2017-09-01

Bolalipids with a long alkyl chain and two phosphocholine polar groups self-assemble in water into two different types of aggregate structures, namely helical nanofibers at low temperature and two types of micellar aggregates at higher temperature. We tried to determine the critical aggregation concentration (cac) or critical micellar concentration (cmc) of the bolalipid tetracosane-1,24-bis(phosphocholine) (PC-C24-PC) by using different fluorescent probes. The use of pyrene or pyrene derivatives as fluorophores failed, whereas the probes 1,8-ANS and particularly bis-ANS gave consistent results. The structure of the bolalipid aggregates obviously hinders partitioning or binding of pyrene derivatives into the micellar interior, whereas 1,8-ANS and bis-ANS can bind to the surface of the aggregate structures. The observed large increase in fluorescence intensity of bis-ANS indicates that binding to the hydrophobic surface of the aggregates leads to a reduction of the dye mobility. However, binding of bis-ANS is relatively weak, so that the determination of a cac/cmc-value is difficult. Simulations of the intensity curves for PC-C24-PC lead to estimates of the cac/cmc-value of 0.3-1.0×10 -6 M, depending on the structure of the aggregates. Single molecule fluorescence correlation spectroscopy was used to determine the mobility of bis-ANS as a function of concentration of PC-C24-PC. The dye diffusion time and the molecular brightness are lower at low bolalipid concentration, when only free dye is present, and increase at higher concentration when bis-ANS is bound to the aggregates. The experimental cac/cmc-values are higher than those estimated, using an incremental method for the change in Gibbs free energy for micellization with n-alkyl-phosphocholines with only one polar group as a comparison. Apparently, for PC-C24-PC in micellar or fibrous aggregates, more CH 2 groups are exposed to water than in a conventional micelle of an n-alkyl-phosphocholine. Copyright �

Quantum group gauge theory on quantum spaces

International Nuclear Information System (INIS)

Brzezinski, T.; Majid, S.

1993-01-01

We construct quantum group-valued canonical connections on quantum homogeneous spaces, including a q-deformed Dirac monopole on the quantum sphere of Podles quantum differential coming from the 3-D calculus of Woronowicz on SU q (2). The construction is presented within the setting of a general theory of quantum principal bundles with quantum group (Hopf algebra) fiber, associated quantum vector bundles and connection one-forms. Both the base space (spacetime) and the total space are non-commutative algebras (quantum spaces). (orig.)

Does CMC Promote Language Play? Exploring Humor in Two Modalities

Science.gov (United States)

Vandergriff, Ilona; Fuchs, Carolin

2009-01-01

In view of the growing body of research on humor and language play in computer-mediated communication (CMC) which--more than any other medium--has been associated with goofing off, joking, and other nonserious communication, this paper compares spontaneous foreign language play (L2 play) in text-only synchronous computer-mediated versus…

Effective utilization of agro-waste by application of CMC dry-gel

International Nuclear Information System (INIS)

Yoshii, Fumio

2008-01-01

Radiation crosslinking, graft polymerization and degradation are useful technologies to improve polymer materials. Processability of radial tires and heat resistance of wire/cable is improved by crosslinking technology. Polysaccharides such as starch/cellulose of natural polymers and their derivatives are typical degradable polymers. Molecular weight of polysaccharides was remarkably reduced at lower dose, 50 kGy. To expand application field of polysaccharides, it is essential to obtain crosslinking structure. It was found that polysaccharide derivatives such as carboxymethyl cellulose (CMC) and carboxymethyl chitosan undergo crosslinking at past-like condition and form hydrogels. Concentration of past-like condition to induce crosslinking should be more than 10%. High molecular weight (Mw) and high degree of substitution (DS) is preferable for crosslinking of polysaccharide derivatives. In this paper, treatment of agro waste and improvement of Japanese traditional paper by addition of CMC dry gel is reported. (author)

Canadian space agency discipline working group for space dosimetry and radiation science

International Nuclear Information System (INIS)

Waker, Anthony; Waller, Edward; Lewis, Brent; Bennett, Leslie; Conroy, Thomas

2008-01-01

Full text: One of the great technical challenges in the human and robotic exploration of space is the deleterious effect of radiation on humans and physical systems. The magnitude of this challenge is broadly understood in terms of the sources of radiation, however, a great deal remains to be done in the development of instrumentation, suitable for the space environment, which can provide real-time monitoring of the complex radiation fields encountered in space and a quantitative measure of potential biological risk. In order to meet these research requirements collaboration is needed between experimental nuclear instrumentation scientists, theoretical scientists working on numerical modeling techniques and radiation biologists. Under the auspices of the Canadian Space Agency such a collaborative body has been established as one of a number of Discipline Working Groups. Members of the Space Dosimetry and Radiation Science working group form a collaborative network across Canada including universities, government laboratories and the industrial sector. Three central activities form the core of the Space Dosimetry and Radiation Science DWG. An instrument sub-group is engaged in the development of instruments capable of gamma ray, energetic charged particle and neutron dosimetry including the ability to provide dosimetric information in real-time. A second sub-group is focused on computer modeling of space radiation fields in order to assess the performance of conceptual designs of detectors and dosimeters or the impact of radiation on cellular and sub-cellular biological targets and a third sub-group is engaged in the study of the biological effects of space radiation and the potential of biomarkers as a method of assessing radiation impact on humans. Many working group members are active in more than one sub-group facilitating communication throughout the whole network. A summary progress-report will be given of the activities of the Discipline Working Group and the

Preparation and characterization of micro-cell membrane chromatographic column with N-hydroxysuccinimide group-modified silica-based porous layer open tubular capillary.

Science.gov (United States)

Xu, Liang; Xu, Bei; Zhao, Zhi-Yu; Yang, Hui-Ping; Tang, Cheng; Dong, Lin-Yi; Liu, Kun; Fu, Li; Wang, Xian-Hua

2017-09-22

Cell membrane chromatography (CMC) is an effective tool in screening active compounds from natural products and studying membrane protein interactions. Nevertheless, it always consumes a large amount of cells (e.g. 10 7 -10 8 ) for column preparation. To overcome this, micro-CMC (mCMC), that employs a silica capillary as membrane carrier, was developed. However, both CMC and mCMC suffer from short column life span (e.g. 3days), mainly due to the falling-off of cellular membranes (CMs). This has greatly limited further application of CMC and mCMC, especially when the cells are hard to obtain. To solve this, N-hydroxysuccinimide (NHS)-modified silica-based porous layer open tubular capillary was first prepared for mCMC. The NHS groups can easily react with amino groups on CMs to form a stable covalent bond under a mild condition. So, CMs immobilized on the NHS-modified capillary are less likely to fall off. To verify this, SKBR3/mCMC (Her2 positive) and BALL1/mCMC (CD20 positive) columns were prepared. Two monoclonal antibody drugs, trastuzumab (anti-Her2) and rituximab (anti-CD20), were selected as analytes to characterize the columns. As a result, NHS-modified column for mCMC can afford higher chromatographic retention than non-modified column. Besides, the column life span was significantly improved to more than 16days for SKBR3/mCMC and 14days for BALL1/mCMC, while the compared column showed a sharp decline in retention factor in first 3days. Copyright © 2017 Elsevier B.V. All rights reserved.

METHODOLOGICAL HURDLES IN CAPTURING CMC DATA: THE CASE OF THE MISSING SELF-REPAIR

Directory of Open Access Journals (Sweden)

Bryan Smith

2008-02-01

Full Text Available This paper reports on a study of the use of self-repair among learners of German in a task-based CMC environment. The purpose of the study was two-fold. The first goal sought to establish how potential interpretations of CMC data may be very different depending on the method of data collection and evaluation employed. The second goal was to explicitly examine the nature of CMC self-repair in the task-based foreign language CALL classroom. Paired participants (n=46 engaged in six jigsaw tasks over the course of one university semester via the chat function in Blackboard. Chat data were evaluated first by using only the chat log file and second by examining a video file of the screen capture of the entire interaction. Results show a fundamental difference in the interpretation of the chat interaction which varies as a function of the data collection and evaluation methods employed. The findings also suggest a possible difference in the nature of self-repair across face-to-face and SCMC environments. In view of the results, this paper calls for CALL researchers to abandon the reliance on printed chat log files when attempting to interpret SCMC interactional data.

Sobolev Spaces on Locally Compact Abelian Groups: Compact Embeddings and Local Spaces

Directory of Open Access Journals (Sweden)

Przemysław Górka

2014-01-01

Full Text Available We continue our research on Sobolev spaces on locally compact abelian (LCA groups motivated by our work on equations with infinitely many derivatives of interest for string theory and cosmology. In this paper, we focus on compact embedding results and we prove an analog for LCA groups of the classical Rellich lemma and of the Rellich-Kondrachov compactness theorem. Furthermore, we introduce Sobolev spaces on subsets of LCA groups and study its main properties, including the existence of compact embeddings into Lp-spaces.

CMC-coated Fe{sub 3}O{sub 4} nanoparticles as new MRI probes for hepatocellular carcinoma

Energy Technology Data Exchange (ETDEWEB)

Sitthichai, Sudarat [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Pilapong, Chalermchai, E-mail: chalermchai.pilapong@cmu.ac.th [Center of Excellence for Molecular Imaging (CEMI), Department of Radiologic Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongtem, Titipun [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongtem, Somchai, E-mail: schthongtem@yahoo.com [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

2015-11-30

Highlights: • Fe{sub 3}O{sub 4} nanoparticles (NPs) are superparamagnetic. • CMC is water-soluble and nontoxic cellulose-derivative polymer. • CMC-coated Fe{sub 3}O{sub 4} NPs were successfully prepared by co-precipitation method. • The promising NPs that can be used for magnetic resonance imaging application. - Abstract: Pure Fe{sub 3}O{sub 4} nanoparticles and Fe{sub 3}O{sub 4} magnetic nanoparticles (MNPs) coated with carboxymethyl cellulose (CMC) were successfully prepared by co-precipitating of FeCl{sub 2}·4H{sub 2}O and FeCl{sub 3}·6H{sub 2}O in the solutions containing ammonia at 80 °C for 3 h. Phase, morphology, particle-sized distribution, surface chemistry, and weight loss were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) including high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED), thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR) spectroscopy. In this research, CMC-coated Fe{sub 3}O{sub 4} MNPs consisting of Fe{sup 2+} and Fe{sup 3+} ions with 543.3-mM{sup −1} s{sup −1} high relaxivity were detected and were able to be used for magnetic resonance imaging (MRI) application with very good contrast for targeting hepatocellular carcinoma (HCC) without any further vectorization.

Noncommutative phase spaces on Aristotle group

Directory of Open Access Journals (Sweden)

Ancille Ngendakumana

2012-03-01

Full Text Available We realize noncommutative phase spaces as coadjoint orbits of extensions of the Aristotle group in a two dimensional space. Through these constructions the momenta of the phase spaces do not commute due to the presence of a naturally introduced magnetic eld. These cases correspond to the minimal coupling of the momentum with a magnetic potential.

Persistence of oral coatings of CMC and starch-based custard desserts

NARCIS (Netherlands)

Wijk, de R.A.; Kapper, C.; Borsboom, P.; Prinz, J.F.

2009-01-01

Food coatings that remain after swallowing starch-based or CMC-based custard desserts were investigated for 19 subjects. Foods were orally processed for 5 s using a pre-defined protocol, after which the food was swallowed. The remaining food coating was assessed sensorially as well as instrumentally

Retabulation of space group extinctions for electron diffraction

International Nuclear Information System (INIS)

Goodman, P.; Tanaka, M.

1989-01-01

The space group tables previously published by one of the authors and others are here presented in a revised and compacted form designed to make for compatability with existing tables for X-ray diffraction. 136 of the 230 space groups are subject to dynamic extinctions due to glide planes and screw axes, and the observables from these space groups in specific settings are tabulated. Tabs

Group structure and group process for effective space station astronaut teams

Science.gov (United States)

Nicholas, J. M.; Kagan, R. S.

1985-01-01

Space Station crews will encounter new problems, many derived from the social interaction of groups working in space for extended durations. Solutions to these problems must focus on the structure of groups and the interaction of individuals. A model of intervention is proposed to address problems of interpersonal relationships and emotional stress, and improve the morale, cohesiveness, and productivity of astronaut teams.

Student Facebook groups as a third space

DEFF Research Database (Denmark)

Aaen, Janus Holst; Dalsgaard, Christian

2016-01-01

-institutional, personal space of the Facebook network. The main study of the article examines six student-managed Facebook groups and provides an analysis of a total of 2247 posts and 12,217 comments. Furthermore, the study draws on group interviews with students from 17 Danish upper secondary schools and a survey......The paper examines educational potentials of Facebook groups that are created and managed by students without any involvement from teachers. The objective is to study student-managed Facebook groups as a ‘third space' between the institutional space of teacher-managed Facebook groups and the non...... answered by 932 students from 25 schools. Based on the survey and interviews, the paper concludes that Facebook is an important educational tool for students in Danish upper secondary schools to receive help on homework and assignments. Furthermore, on the basis of the analysis of Facebook groups...

Efficient simultaneous removal of U(VI) and Cu(II) from aqueous solution using core-shell nZVI@SA/CMC-Ca beads

International Nuclear Information System (INIS)

Shuhong Hu; Xiaoyan Lin; Wenhui Zhao; Ministry of Education, Sichuan; Xuegang Luo

2018-01-01

Core-shell nanoscale zero-valent iron@alginate/carboxymethyl cellulose sodium composite loaded with calcium (nZVI@SA/CMC-Ca) beads were synthesized in this study using coaxial electronic injection method. The adsorbent structure was characterized via FT-IR, SEM, EDX and XPS. The adsorption behavior of U(VI) and Cu(II) on core-shell nZVI@SA/CMC-Ca beads was studied under various experimental parameters like pH, contact time and temperature. The isotherm and the kinetic data, pertaining to the adsorption of U(VI) and Cu(II) by core-shell nZVI@SA/CMC-Ca beads obeyed both the Langmuir and Freundlich isotherms model and the pseudo-second-order kinetics model, respectively. The thermodynamic parameters revealed the spontaneous and endothermic nature of the adsorption. The experiment of regeneration and reusability suggested core-shell nZVI@SA/CMC-Ca bead was a regenerated material. (author)

Practical use of CMC-amended rhizobial inoculant for Mucuna pruriens cultivation to enhance the growth and protection against Macrophomina phaseolina.

Science.gov (United States)

Aeron, Abhinav; Khare, Ekta; Kumar Arora, Naveen; Kumar Maheshwari, Dinesh

2012-01-01

In many parts of the world Mucuna pruriens is used as an important medicinal, forage and green manure crop. In the present investigation the effect of the addition of CMC in carrier during development of bioformulation on shelflife, plant growth promotive and biocontrol activity against Macrophomina phaseolina was screened taking M. pruriens as a test crop. Ensifer meliloti RMP6(Ery+Kan+) and Bradyrhizobium sp. BMP7(Tet+Kan+) (kanamycin resistance engineered by Tn5 transposon mutagenesis) used in the study showed production of siderophore, IAA, solubilizing phosphate and biocontrol of M. phaseolina. RMP6(Ery+Kan+) also showed ACC deaminase activity. The survival of both the strains in sawdust-based bioformulation was enhanced with an increase in the concentration of CMC from 0 to 1%. At 0% CMC Bradyrhizobium sp. BMP7(Tet+Kan+) showed more increase in nodule number/plant (500.00%) than E. meliloti RMP6(Ery+Kan+) (52.38%), over the control in M. phaseolina-infested soil. There was 185.94% and 59.52% enhancement in nodule number/plant by RMP6(Ery+Kan+) and BMP7(Tet+Kan+) with an increase in the concentration of CMC from 0% to 1% in the bioformulations. However further increase in concentration of CMC did not result in enhancement in survival of either the strains or nodule number/plant.

Influence of Polyethylene Glycol (PEG in CMC-NH4BR Based Polymer Electrolytes: Conductivity and Electrical Study

Directory of Open Access Journals (Sweden)

Nur Khalidah Zainuddin

2017-04-01

Full Text Available The present work was carried with new type and promising polymer electrolytes system by development of carboxylmethylcellulose (CMC doped NH4Br and plasticized with polyethylene glycol (PEG. The sample was successfullyprepared via solution casting with no separation phase and good mechanical properties. The electrical conductivity andthermal conductivity of CMC-NH4Br-PEG based PEs system have been measured by the electrical impedancespectroscopy method in the temperature range of 303–373 K. The highest ionic conductivity gained is 2.48 x 10-3 Scm-1at ambient temperature for sample contain with 8 wt. % PEG. It can be concluded that the plasticized is accountable forthe conductance and assist to enhancing the ionic conductivity of the CMC-NH4Br-PEG electrolyte system. The addition of PEG to the CMC-based electrolyte can enhance towards the cation mobility which is turn increases ionic conductivity. The conductivity-temperature of plasticized BdPEs system was found obeys the Arrhenius relation where the ionic conductivity increases with temperature and activation energy for the ions hopping of the highest conducting PEs system only required small value to migrate. The electrical studies show a non-Debye behaviour of BdPEs based on the analyzed data using complex permittivity, ε* and complex electrical modulus, M* of the sample at different temperature.

SiC-CMC-Zircaloy-4 Nuclear Fuel Cladding Performance during 4-Point Tubular Bend Testing

Energy Technology Data Exchange (ETDEWEB)

IJ van Rooyen; WR Lloyd; TL Trowbridge; SR Novascone; KM Wendt; SM Bragg-Sitton

2013-09-01

The U.S. Department of Energy Office of Nuclear Energy (DOE NE) established the Light Water Reactor Sustainability (LWRS) program to develop technologies and other solutions to improve the reliability, sustain the safety, and extend the life of current reactors. The Advanced LWR Nuclear Fuel Development Pathway in the LWRS program encompasses strategic research focused on improving reactor core economics and safety margins through the development of an advanced fuel cladding system. Recent investigations of potential options for “accident tolerant” nuclear fuel systems point to the potential benefits of silicon carbide (SiC) cladding. One of the proposed SiC-based fuel cladding designs being investigated incorporates a SiC ceramic matrix composite (CMC) as a structural material supplementing an internal Zircaloy-4 (Zr-4) liner tube, referred to as the hybrid clad design. Characterization of the advanced cladding designs will include a number of out-of-pile (nonnuclear) tests, followed by in-pile irradiation testing of the most promising designs. One of the out-of-pile characterization tests provides measurement of the mechanical properties of the cladding tube using four point bend testing. Although the material properties of the different subsystems (materials) will be determined separately, in this paper we present results of 4-point bending tests performed on fully assembled hybrid cladding tube mock-ups, an assembled Zr-4 cladding tube mock-up as a standard and initial testing results on bare SiC-CMC sleeves to assist in defining design parameters. The hybrid mock-up samples incorporated SiC-CMC sleeves fabricated with 7 polymer impregnation and pyrolysis (PIP) cycles. To provide comparative information; both 1- and 2-ply braided SiC-CMC sleeves were used in this development study. Preliminary stress simulations were performed using the BISON nuclear fuel performance code to show the stress distribution differences for varying lengths between loading points

Hazy spaces, tangent spaces, manifolds and groups

International Nuclear Information System (INIS)

Dodson, C.T.J.

1977-03-01

The results on hazy spaces and the developments leading to hazy manifolds and groups are summarized. Proofs have appeared elsewhere so here examples are considered and some motivation for definitions and constructions in the theorems is analyzed. It is shown that quite simple ideas, intuitively acceptable, lead to remarkable similarity with the theory of differentiable manifolds. Hazy n manifolds have tangent bundles that are hazy 2n manifolds and there are hazy manifold structures for groups. Products and submanifolds are easily constructed and in particular the hazy n-sphere manifolds as submanifolds of the standard hazy manifold Zsup(n+1)

String cohomology groups of complex projective spaces

DEFF Research Database (Denmark)

Ottosen, Iver; Bökstedt, Marcel

2007-01-01

Let X be a space and write LX for its free loop space equipped with the action of the circle group T given by dilation. The equivariant cohomology H*(LXhT;Z/p) is a module over H*(BT;Z/p). We give a computation of this module when X=CPr for any positive integer r and any prime number p. The compu......Let X be a space and write LX for its free loop space equipped with the action of the circle group T given by dilation. The equivariant cohomology H*(LXhT;Z/p) is a module over H*(BT;Z/p). We give a computation of this module when X=CPr for any positive integer r and any prime number p...

Carboxymethyl cellulose (CMC)-loaded Co-Cu doped manganese ferrite nanorods as a new dual-modal simultaneous contrast agent for magnetic resonance imaging and nanocarrier for drug delivery system

Science.gov (United States)

Abbasi Pour, Sajjad; Shaterian, Hamid Reza; Afradi, Mojgan; Yazdani-Elah-Abadi, Afshin

2017-09-01

We synthesized Co0.25Cu0.25Mn0.5Fe2O4@CMC (CCMFe2O4@CMC) nanorods as a new dual-modal simultaneous for magnetic resonance imaging contrast agent and nanocarrier for drug delivery system. Impact of CCMFe2O4@CMC nanorods were investigated on the longitudinal (T1), transverse (T2) and transverse (T2∗) relaxation times for in vitro MRI contrast agent in water and also for drug delivery system, L-dopa was coated on CCMFe2O4@CMC nanorods and then in vitro drug release test was carried out at three PHs values and different temperatures. In vitro MR imaging demonstrated that r2 value of CCMFe2O4@CMC nanorods is 138.33 mM-1 s-1, CCMFe2O4@CMC is useful as T2 contrast agent relative to other T2 contrast agants. In vitro drug release test shows the amount of released L-dopa from CCMFe2O4@CMC nanorods at medium with pH = 1.2 is more than pH = 5.3 and 7.4.

The International Space Life Sciences Strategic Planning Working Group

Science.gov (United States)

White, Ronald J.; Rabin, Robert; Lujan, Barbara F.

1993-01-01

Throughout the 1980s, ESA and the space agencies of Canada, Germany, France, Japan, and the U.S. have pursued cooperative projects bilaterally and multilaterally to prepare for, and to respond to, opportunities in space life sciences research previously unapproachable in scale and sophistication. To cope effectively with likely future space research opportunities, broad, multilateral, coordinated strategic planning is required. Thus, life scientists from these agencies have allied to form the International Space Life Sciences Strategic Planning Working Group. This Group is formally organized under a charter that specifies the purpose of the Working Group as the development of an international strategic plan for the space life sciences, with periodic revisions as needed to keep the plan current. The plan will be policy-, not operations-oriented. The Working Group also may establish specific implementation teams to coordinate multilateral science policy in specific areas; such teams have been established for space station utilization, and for sharing of flight equipment.

Language, mobile phones and internet : a study of SMS texting, email, IM and SNS chats in computer mediated communication (CMC) in Kenya

NARCIS (Netherlands)

Barasa, Sandra Nekesa

2010-01-01

This book examines the use of language in Computer Mediated Communication (CMC) genres in Kenya. It focuses on Short Messaging Service (SMS), Email, Instant Messages (IM) and Social Network Sites (SNS) genres. It presents an overview of the use and characteristics of Kenyan languages in CMC texts

My First CMC Article Revisited: A Window on Spanish L2 Interlanguage

Science.gov (United States)

Blake, Robert

2016-01-01

The computer-assisted language learning (CALL) field seems to change overnight with new technological affordances. Blake revisits his 2000 "LLT" article on computer-mediation communication (CMC) in order to reflect on how the field has examined this topic over the past decade or so. While the Interaction Hypothesis continues to guide…

Mapping Spaces, Centralizers, and p-Local Finite Groups of Lie Type

DEFF Research Database (Denmark)

Laude, Isabelle

We study the space of maps from the classifying space of a finite p-group to theBorel construction of a finite group of Lie type G in characteristic p acting on itsbuilding. The first main result is a description of the homology with Fp-coefficients,showing that the mapping space, up to p...... between a finite p-group and theuncompleted classifying space of the p-local finite group coming from a finite groupof Lie type in characteristic p, providing some of the first results in this uncompletedsetting.......-completion, is a disjoint union indexedover the group homomorphism up to conjugation of classifying spaces of centralizersof p-subgroups in the underlying group G. We complement this description bydetermining the actual homotopy groups of the mapping space. These resultstranslate to descriptions of the space of maps...

The formation of group norms in computer-mediated communication

NARCIS (Netherlands)

Postmes, T; Spears, R; Lea, M

The formation of group norms in computer-mediated communication (CMC) was examined among students who used e-mail as part of a course. A network analysis of group structures revealed that (a) content and form of communication is normative, group norms defining communication patterns within groups,

NASA's Internal Space Weather Working Group

Science.gov (United States)

St. Cyr, O. C.; Guhathakurta, M.; Bell, H.; Niemeyer, L.; Allen, J.

2011-01-01

Measurements from many of NASA's scientific spacecraft are used routinely by space weather forecasters, both in the U.S. and internationally. ACE, SOHO (an ESA/NASA collaboration), STEREO, and SDO provide images and in situ measurements that are assimilated into models and cited in alerts and warnings. A number of years ago, the Space Weather laboratory was established at NASA-Goddard, along with the Community Coordinated Modeling Center. Within that organization, a space weather service center has begun issuing alerts for NASA's operational users. NASA's operational user community includes flight operations for human and robotic explorers; atmospheric drag concerns for low-Earth orbit; interplanetary navigation and communication; and the fleet of unmanned aerial vehicles, high altitude aircraft, and launch vehicles. Over the past three years we have identified internal stakeholders within NASA and formed a Working Group to better coordinate their expertise and their needs. In this presentation we will describe this activity and some of the challenges in forming a diverse working group.

Quantum groups and quantum homogeneous spaces

International Nuclear Information System (INIS)

Kulish, P.P.

1994-01-01

The usefulness of the R-matrix formalism and the reflection equations is demonstrated on examples of the quantum group covariant algebras (quantum homogeneous spaces): quantum Minkowski space-time, quantum sphere and super-sphere. The irreducible representations of some covariant algebras are constructed. The generalization of the reflection equation to super case is given and the existence of the quasiclassical limits is pointed out. (orig.)

A CMC conference-focus heads-up. Paper A

International Nuclear Information System (INIS)

Plourde, J.

2011-01-01

'Predictability' [definition - 'Dependable Outcomes Based on Pre-Verified Plans and Processes'] - is key to nuclear industry public and stakeholder confidence - predictability in public, employee, and environmental safety; in reliable production; in improvement and refurbishment project execution; and in overall financial performance. CMC 2011 addresses this by focusing on; Utility experience with optimally-managed outages in well-run plants, on the ways-of-working processes, tools and behaviors required by the industry to succeed; applying lessons-learned to hugely-complex and scope-expansion prone projects like refurbishments- and eventually new-build. Configuration management, operating chemistry, Utility/Service-Provider interfaces, and intelligent replication are explored along the way. (author)

Overview of Cooperative Monitoring Concepts and the CMC

International Nuclear Information System (INIS)

Biringer, Kent L.

1999-01-01

Cooperative monitoring holds the promise of utilizing many technologies from conflicts of the past to implement agreements of peace in the future. Important approaches to accomplish this are to develop the framework for assessing monitoring opportunities and to provide education and training on the technologies and experience available for sharing with others. The Cooperative Monitoring Center (CMC) at Sandia National Laboratories is working closely with agencies throughout the federal government, academics at home and abroad, and regional organizations to provide the technical tools needed to assess, design, analyze, and implement these cooperative agreements. In doing so, the goals of building regional confidence and increasing trust and communication can be furthered

A CMC conference-focus heads-up. Paper A

Energy Technology Data Exchange (ETDEWEB)

Plourde, J. [J.A. Plourde Performance Ltd., Oshawa, Ontario (Canada)

2011-07-01

'Predictability' [definition - 'Dependable Outcomes Based on Pre-Verified Plans and Processes'] - is key to nuclear industry public and stakeholder confidence - predictability in public, employee, and environmental safety; in reliable production; in improvement and refurbishment project execution; and in overall financial performance. CMC 2011 addresses this by focusing on; Utility experience with optimally-managed outages in well-run plants, on the ways-of-working processes, tools and behaviors required by the industry to succeed; applying lessons-learned to hugely-complex and scope-expansion prone projects like refurbishments- and eventually new-build. Configuration management, operating chemistry, Utility/Service-Provider interfaces, and intelligent replication are explored along the way. (author)

Space Interferometry Science Working Group

Science.gov (United States)

Ridgway, Stephen T.

1992-12-01

Decisions taken by the astronomy and astrophysics survey committee and the interferometry panel which lead to the formation of the Space Interferometry Science Working Group (SISWG) are outlined. The SISWG was formed by the NASA astrophysics division to provide scientific and technical input from the community in planning for space interferometry and in support of an Astrometric Interferometry Mission (AIM). The AIM program hopes to measure the positions of astronomical objects with a precision of a few millionths of an arcsecond. The SISWG science and technical teams are described and the outcomes of its first meeting are given.

Symmetries of quantum spaces. Subgroups and quotient spaces of quantum SU(2) and SO(3) groups

International Nuclear Information System (INIS)

Podles, P.

1995-01-01

We prove that each action of a compact matrix quantum group on a compact quantum space can be decomposed into irreducible representations of the group. We give the formula for the corresponding multiplicities in the case of the quotient quantum spaces. We describe the subgroups and the quotient spaces of quantum SU(2) and SO(3) groups. (orig.)

Singularities of spacelike constant mean curvature surfaces in Lorentz-Minkowski space

DEFF Research Database (Denmark)

Brander, David

2011-01-01

We study singularities of spacelike, constant (non-zero) mean curvature (CMC) surfaces in the Lorentz-Minkowski 3-space L-3. We show how to solve the singular Bjorling problem for such surfaces, which is stated as follows: given a real analytic null-curve f(0)(x), and a real analytic null vector...... field v(x) parallel to the tangent field of f(0), find a conformally parameterized (generalized) CMC H surface in L-3 which contains this curve as a singular set and such that the partial derivatives f(x) and f(y) are given by df(0)/dx and v along the curve. Within the class of generalized surfaces...

Synthesis and electrospinning carboxymethyl cellulose lithium (CMC-Li) modified 9,10-anthraquinone (AQ) high-rate lithium-ion battery.

Science.gov (United States)

Qiu, Lei; Shao, Ziqiang; Liu, Minglong; Wang, Jianquan; Li, Pengfa; Zhao, Ming

2014-02-15

New cellulose derivative CMC-Li was synthesized, and nanometer CMC-Li fiber was applied to lithium-ion battery and coated with AQ by electrospinning. Under the protection of inert gas, modified AQ/carbon nanofibers (CNF)/Li nanometer composite material was obtained by carbonization in 280 °C as lithium battery anode materials for the first time. The morphologies and structures performance of materials were characterized by using IR, (1)H NMR, SEM, CV and EIS, respectively. Specific capacity was increased from 197 to 226.4 mAhg(-1) after modification for the first discharge at the rate of 2C. Irreversible reduction reaction peaks of modified material appeared between 1.5 and 1.7 V and the lowest oxidation reduction peak of the difference were 0.42 V, the polarization was weaker. Performance of cell with CMC-Li with the high degree of substitution (DS) was superior to that with low DS. Cellulose materials were applied to lithium battery to improve battery performance by electrospinning. Copyright © 2013 Elsevier Ltd. All rights reserved.

The effect of CMC and arabic gum stabilizer combination on the characteristics of soursop velva (Annona muricata L.)

Science.gov (United States)

Parnanto, N. H. R.; Yudhistira, B.; Pertiwi, S. R.; Pangestika, A.

2018-03-01

The aims of this study were to determine the effect of the combination of CMC and Arabic Gum stabilizer toward the soursop velva characteristics and to determine the best stabilizer combination of soursop velva. This study was performed using Completely Randomized Design (CRD) with one factor: combination of CMC and Arabic Gum stabilizer using two sample replications and the analysis was repeated three times. The result showed that the use of the combination of CMC and Arabic Gum stabilizer gave a significant effect on the overrun value, melting power, total dissolved solids, moisture content, dietary fiber, taste, texture and overalls. Moreover, there were no significant effect on color and flavor of the soursop velva. The experiment showed that soursop velva F4 (3:1) was the best formula with overrun value 9.93%, the melting power was 22 minutes 52 seconds, the total dissolved solids 19,10°Brix, the moisture content 71.508%, dietary fiber 3.301% and it has sensory values of color, taste, flavor, texture, overall at 3.66, 3.267, 3.33, 4.06, 3.10 respectively.

Study of wine tartaric acid salt stabilization by addition of carboxymethylcellulose (CMC: comparison with the « protective colloids » effect

Directory of Open Access Journals (Sweden)

Vincent Gerbaud

2010-12-01

Significance and impact of the study: The OIV-OENO 366-2009 and OIV-OENO 02/2008 resolutions recently authorized the use of CMC to prevent tartaric acid salt precipitation. With no impact on health, and stable under heating and in acid solution, CMC is an efficient candidate for tartaric stabilization. The optimal concentration of 20 mg.L-1 (2 g.hL-1 should however be adapted to local wine storage conditions and KHT crystallization risk.

Retention of storage quality and post-refrigeration shelf-life extension of plum (Prunus domestica L.) cv. Santa Rosa using combination of carboxymethyl cellulose (CMC) coating and gamma irradiation

International Nuclear Information System (INIS)

Hussain, Peerzada R.; Suradkar, Prashant P.; Wani, Ali M.; Dar, Mohd A.

2015-01-01

Carboxymethyl cellulose (CMC) coatings alone and in combination with gamma irradiation was tested for maintaining the storage quality and extending shelf-life of plum. Matured green plums were CMC coated at levels 0.5–1.0% w/v and gamma irradiated at 1.5 kGy. The treated fruit including control was stored under ambient (temperature 25±2 °C, RH 70%) and refrigerated (temperature 3±1 °C, RH 80%) conditions. In fruits treated with individual treatments of 1.0% w/v CMC; 1.5 kGy irradiation and combination of 1.0% w/v CMC and 1.5 kGy irradiation, no decay was recorded up to 11, 17 and 21 days of ambient storage. Irradiation alone at 1.5 kGy gave 8 days extension in shelf-life of plum compared to 5 days by 1.0% w/v CMC coating following 45 days of refrigeration. All combinatory treatments of CMC coating and irradiation proved beneficial in maintaining the storage quality as well as delaying the decaying of plum during post-refrigerated storage at 25±2 °C, RH 70% but, combination of CMC at 1.0% w/v and 1.5 kGy irradiation was found significantly (p≤0.05) superior to all other treatments in maintaining the storage quality and delaying the decaying of plum. CMC coating of plums at 1.0% w/v followed by irradiation at 1.5 kGy resulted in chlorophyll retention of 19.4% after 16 days compared to 10% in control after 8 days of ambient storage. Under refrigerated conditions, same treatment gave retention of 67.6% in chlorophyll compared to 10.6% in control after 35 days of storage. The above combinatory treatment resulted in extension of 11 days in shelf-life of plum during post-refrigerated storage at 25±2 °C, RH 70% following 45 days of refrigeration. Based on microbial analysis, irradiation alone at 1.5 kGy and in combination with 1.0% w/v CMC resulted in 2.0 and 1.8 log reduction in yeast and mold count of plum fruit after 20 and 35 days of ambient and refrigerated storage, thereby ensuring consumer safety. - Highlights: • Irradiation and CMC alone at 1.5 k

Language Learning Going Global: Linking Teachers and Learners via Commercial Skype-Based CMC

Science.gov (United States)

Terhune, N. M.

2016-01-01

This paper reports on students' use of face-to-face synchronous computer-mediated communication (CMC) for oral language learning. It describes a university English language class designed to prepare students for overseas study in which a Skype-based English conversation school was piloted. The study offers analysis of how students used the CMC…

Calorimetric Evidence about the Application of the Concept of CMC to Asphaltene Self-Association

DEFF Research Database (Denmark)

Garcia, Daniel Merino; Andersen, Simon Ivar

2005-01-01

that asphaltenes may also have a concentration at which self-association occurs (CMC). This article presents evidence found by calorimetry and spectroscopic techniques, that suggest that this concept may not be adequate for asphaltene self-association in toluene solutions. Isothermal titration calorimetry has been...

Professional Discussion Groups: Informal Learning in a Third Space

Science.gov (United States)

Jordan, Robert A.

2013-01-01

In this ethnographic study, I explored two discussion groups and discovered Third Space elements such as cultural hybridity, counterscript, and sharing of experiences and resources contributed to a safe learning environment existing at the boundaries between participant personal and professional spaces. The groups operated under the auspices of a…

Group theoretical construction of planar noncommutative phase spaces

Energy Technology Data Exchange (ETDEWEB)

Ngendakumana, Ancille, E-mail: nancille@yahoo.fr; Todjihoundé, Leonard, E-mail: leonardt@imsp.uac.org [Institut de Mathématiques et des Sciences Physiques (IMSP), Porto-Novo (Benin); Nzotungicimpaye, Joachim, E-mail: kimpaye@kie.ac.rw [Kigali Institute of Education (KIE), Kigali (Rwanda)

2014-01-15

Noncommutative phase spaces are generated and classified in the framework of centrally extended anisotropic planar kinematical Lie groups as well as in the framework of noncentrally abelian extended planar absolute time Lie groups. Through these constructions the coordinates of the phase spaces do not commute due to the presence of naturally introduced fields giving rise to minimal couplings. By symplectic realizations methods, physical interpretations of generators coming from the obtained structures are given.

Group theoretical construction of planar noncommutative phase spaces

International Nuclear Information System (INIS)

Ngendakumana, Ancille; Todjihoundé, Leonard; Nzotungicimpaye, Joachim

2014-01-01

Noncommutative phase spaces are generated and classified in the framework of centrally extended anisotropic planar kinematical Lie groups as well as in the framework of noncentrally abelian extended planar absolute time Lie groups. Through these constructions the coordinates of the phase spaces do not commute due to the presence of naturally introduced fields giving rise to minimal couplings. By symplectic realizations methods, physical interpretations of generators coming from the obtained structures are given

CMC-coated Fe3O4 nanoparticles as new MRI probes for hepatocellular carcinoma

Science.gov (United States)

Sitthichai, Sudarat; Pilapong, Chalermchai; Thongtem, Titipun; Thongtem, Somchai

2015-11-01

Pure Fe3O4 nanoparticles and Fe3O4 magnetic nanoparticles (MNPs) coated with carboxymethyl cellulose (CMC) were successfully prepared by co-precipitating of FeCl2·4H2O and FeCl3·6H2O in the solutions containing ammonia at 80 °C for 3 h. Phase, morphology, particle-sized distribution, surface chemistry, and weight loss were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) including high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED), thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR) spectroscopy. In this research, CMC-coated Fe3O4 MNPs consisting of Fe2+ and Fe3+ ions with 543.3-mM-1 s-1 high relaxivity were detected and were able to be used for magnetic resonance imaging (MRI) application with very good contrast for targeting hepatocellular carcinoma (HCC) without any further vectorization.

It's Just a Game, Right? Types of Play in Foreign Language CMC

Directory of Open Access Journals (Sweden)

Chantelle N. Warner

2004-05-01

Full Text Available This study focuses on the various playful uses of language that occurred during a semester-long study of two German language courses using one type of synchronous network-based medium, the MOO. Research and use of synchronous computer-mediated communication (CMC have flourished in the study of second-language acquisition (SLA since the late 1990s; however, the primary focus has been on the potential benefits of using CMC to increase the amount of communication (Beauvois, 1997; Kern, 1995; Warschauer, 1997, motivate students (Beauvois, 1997; Kern, 1995; Warschauer, 1997 and foster the exchange of ideas (Beauvois, 1997; Kern, 1995; von der Emde, Schneider, & Kötter, 2001; Warschauer, 1997. Only more recently has research within SLA begun to investigate the types of communication that occur online.1 An analysis of the transcripts from a second-semester German course and an upper-level German communication course reveal that a large portion of the language use online cannot be described using standard referential definitions of communication, but rather is playful in nature. Using research from SLA and theories on social interaction, this article investigates the different types of play that occurred within the online discussions and the possible implications of the presence of play in online discourse.

An exploratory examination of the relationship between motivational factors and the degree to which the higher education faculty integrate computer-mediated communication (CMC) tools into their courses

Science.gov (United States)

Murage, Francis Ndwiga

The stated research problem of this study was to examine the relationship between motivational factors and the degree to which the higher education faculty integrate CMC tools into their courses. The study population and sample involved higher education faculty teaching in science departments at one public university and three public colleges in the state of West Virginia (N = 153). A Likert-type rating scale survey was used to collect data based on the research questions. Two parts of the survey were adopted from previous studies while the other two were self-constructed. Research questions and hypothesis were analyzed using both descriptive and inferential analyses. The study results established a positive relationship between motivational factors and the degree the higher education faculty integrate CMC tools in their courses. The results in addition established that faculty are highly motivated to integrate CMC tools by intrinsic factors, moderately motivated by environmental factors and least motivated by extrinsic factors. The results also established that the most integrated CMC tools were those that support asynchronous methods of communication while the least integrated were those that support synchronous methods of communication. A major conclusion made was that members of higher education faculty are more likely to be motivated to integrate CMC tools into their courses by intrinsic factors rather than extrinsic or environmental factors. It was further concluded that intrinsic factors that supported and enhanced student learning as well as those that were altruistic in nature significantly influenced the degree of CMC integration. The study finally concluded that to larger extent, there is a relationship between motivational factors and the degree to which the higher education faculty integrate CMC tools in their courses. A major implication of this study was that institutions that wish to promote integration of CMC technologies should provide as much

Optical Fiber Assemblies for Space Flight from the NASA Goddard Space Flight Center, Photonics Group

Science.gov (United States)

Ott, Melanie N.; Thoma, William Joe; LaRocca, Frank; Chuska, Richard; Switzer, Robert; Day, Lance

2009-01-01

The Photonics Group at NASA Goddard Space Flight Center in the Electrical Engineering Division of the Advanced Engineering and Technologies Directorate has been involved in the design, development, characterization, qualification, manufacturing, integration and anomaly analysis of optical fiber subsystems for over a decade. The group supports a variety of instrumentation across NASA and outside entities that build flight systems. Among the projects currently supported are: The Lunar Reconnaissance Orbiter, the Mars Science Laboratory, the James Webb Space Telescope, the Express Logistics Carrier for the International Space Station and the NASA Electronic Parts. and Packaging Program. A collection of the most pertinent information gathered during project support over the past year in regards to space flight performance of optical fiber components is presented here. The objective is to provide guidance for future space flight designs of instrumentation and communication systems.

Non-Supramenable Groups Acting on Locally Compact Spaces

DEFF Research Database (Denmark)

Kellerhals, Julian; Monod, Nicolas; Rørdam, Mikael

2013-01-01

Supramenability of groups is characterised in terms of invariant measures on locally compact spaces. This opens the door to constructing interesting crossed product $C^*$-algebras for non-supramenable groups. In particular, stable Kirchberg algebras in the UCT class are constructed using crossed ...

Ab initio computational study of –N-C and –O-C bonding formation : functional group modification reaction based chitosan

Science.gov (United States)

Siahaan, P.; Salimah, S. N. M.; Sipangkar, M. J.; Hudiyanti, D.; Djunaidi, M. C.; Laksitorini, M. D.

2018-04-01

Chitosan application in pharmaceutics and cosmeceutics industries is limited by its solubility issue. Modification of -NH2 and -OH fuctional groups of chitosan by adding carboxyl group has been shown to improve its solubility and application. Attempt to synthesize carboxymethyl chitosan (CMC) from monocloroacetic acid (MCAA) has been done prior this report. However no information is available wether –OH (-O-C bonding formation) or -NH2 (-N-C bonding formation) is the preference for - CH2COOH to attach. In the current study, the reaction mechanism between chitosan and MCAA reactants into carboxymethyl chitosan (CMC) was examined by computational approach. Dimer from of chitosan used as a molecular model in calculation All the molecular structure involved in the reaction mechanism was optimized by ab initio computational on the theory and basis set HF/6-31G(d,p). The results showed that the - N-C bonding formation via SN2 than the -O-C bonding formation via SN2 which have activation energy 469.437 kJ/mol and 533.219 kJ/mol respectively. However, the -O-C bonding formation more spontaneous than the -N-C bonding formation because ΔG the formation of O-CMC-2 reaction is more negative than ΔG of formation N-CMC-2 reaction is -4.353 kJ/mol and -1.095 kJ/mol respectively. The synthesis of N,O-CMC first forms -O-CH2COOH, then continues to form -NH-CH2COOH. This information is valuable to further optimize the reaction codition for CMC synthesis.

The birth of NASA the work of the Space Task Group, America's first true space pioneers

CERN Document Server

von Ehrenfried, Dutch

2016-01-01

This is the story of the work of the original NASA space pioneers; men and women who were suddenly organized in 1958 from the then National Advisory Committee on Aeronautics (NACA) into the Space Task Group. A relatively small group, they developed the initial mission concept plans and procedures for the U. S. space program. Then they boldly built hardware and facilities to accomplish those missions. The group existed only three years before they were transferred to the Manned Spacecraft Center in Houston, Texas, in 1962, but their organization left a large mark on what would follow. Von Ehrenfried's personal experience with the STG at Langley uniquely positions him to describe the way the group was structured and how it reacted to the new demands of a post-Sputnik era. He artfully analyzes how the growing space program was managed and what techniques enabled it to develop so quickly from an operations perspective. The result is a fascinating window into history, amply backed up by first person documentation ...

The space shuttle payload planning working groups: Volume 9: Materials processing and space manufacturing

Science.gov (United States)

1973-01-01

The findings and recommendations of the Materials Processing and Space Manufacturing group of the space shuttle payload planning activity are presented. The effects of weightlessness on the levitation processes, mixture stability, and control over heat and mass transport in fluids are considered for investigation. The research and development projects include: (1) metallurgical processes, (2) electronic materials, (3) biological applications, and (4)nonmetallic materials and processes. Additional recommendations are provided concerning the allocation of payload space, acceptance of experiments for flight, flight qualification, and private use of the space shuttle.

Analysis of cash flow ratios: A study on CMC

Directory of Open Access Journals (Sweden)

Somnath Das

2018-01-01

Full Text Available Cash flow ratios help financial users get relevant information about financial resources for a given time. Cash flow ratios are now used more than the traditional ones because it is more effective and justified. Cash flow based ratios are especially surprising because they do not only play a significant role in the credit rating of evaluation, but also forecast the failure of a corporation. In this study, we perform an empirical investigation on a company named CMC. From the study, it is clear that the liquidity and solvency positions of the company were moderate whereas the company maintained low profitability. On the other hand, the efficiency and sufficiency ratios of the study give us a new look on financial judgement.

Projective unitary-antiunitary representations of the Shubnikov space groups

International Nuclear Information System (INIS)

Broek, P.M. van den.

1979-01-01

Some mathematical aspects of the symmetry of a physical system in quantum mechanics are examined with special emphasis on the symmetry groups of charged particles in crystalline solids, the Shuknikov space groups. (Auth.)

Survey report for fiscal 1999. Report on basic survey on joint implementation of installing coal moisture control (CMC) facilities

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

For the purpose of the COP3 joint implementation in fiscal 1999, a survey and discussions were given on installing coal moisture control (CMC) facilities in China. The possibility was discussed with the Jinan Steel Group Company and Shougang Company. The subject is a beehive coke furnace, in which coal containing 11% of water is sent to a fluidized bed dryer, and dried up to 6.6%. Stack gas in the coke furnace is used mainly as the drying heat source. The facility consists of a fluidized bed dryer, a dust collector, a coal transporter, and a stack gas recovering device. The energy saving effects made available to the above two companies are as remarkable as 19,868 tons/year and 12,189 tons/year, respectively, as converted to crude oil, and the greenhouse effect gas reduction effect as 61,476 tons/year and 37,715 tons/year, respectively. Because energy price is low in China, the investment recovery time period is set at six years or less as the limit for economic performance evaluation. As a result of the calculation, the recovery time periods for the above two companies were found to be 4.2 and 4.7 years, proving the CMC project highly promising. It is desired that the project will be moved forward once the issues of the fund raising and the discharge right of global warming gas are made clear. (NEDO)

Communication Challenges Learners Face Online: Why Addressing CMC and Language Proficiency Will Not Solve Learners' Problems

Science.gov (United States)

Jung-Ivannikova, Liubov

2016-01-01

Computer-mediated communication (CMC) has been argued to cause (mis)communication issues. Research and practice suggest a range of tactics and strategies for educators focused on how to encourage and foster communication in a virtual learning environment (VLE) (eg, Salmon). However, while frameworks such as Salmon's support the effective…

Trimesic acid dimethyl sulfoxide solvate: space group revision

Directory of Open Access Journals (Sweden)

Sylvain Bernès

2008-07-01

Full Text Available The structure of the title solvate, C9H6O6·C2H6OS, was determined 30 years ago [Herbstein, Kapon & Wasserman (1978. Acta Cryst. B34, 1613–1617], with data collected at room temperature, and refined in the space group P21. The present redetermination, based on high-resolution diffraction data, shows that the actual space group is more likely to be P21/m. The crystal structure contains layers of trimesic acid molecules lying on mirror planes. A mirror plane also passes through the S and O atoms of the solvent molecule. The molecules in each layer are interconnected through strong O—H...O hydrogen bonds, forming a two-dimensional supramolecular network within each layer. The donor groups are the hydroxyls of the trimesic acid molecules, while the acceptors are the carbonyl or the sulfoxide O atoms.

Student "Facebook" Groups as a Third Space: Between Social Life and Schoolwork

Science.gov (United States)

Aaen, Janus; Dalsgaard, Christian

2016-01-01

The paper examines educational potentials of "Facebook" groups that are created and managed by students without any involvement from teachers. The objective is to study student-managed "Facebook" groups as a "third space" between the institutional space of teacher-managed "Facebook" groups and the…

Social influence in computer-mediated communication : The effects of anonymity on group behavior

NARCIS (Netherlands)

Postmes, T; Spears, R; Sakhel, K; de Groot, D

2001-01-01

Two studies examined hypotheses derived from a Social Identity model of Deindividuation Effects (SIDE) as applied to social influence in computer-mediated communication (CMC) in groups. This model predicts that anonymity can increase social influence if a common group identity is salient. In a first

Determination of Consciousness and Awareness of the Public in Lefka about the Cyprus Mining Corporation (CMC)

Science.gov (United States)

Gündüz, Serife; Erbulut, Can; Öznacar, Behcet; Bastas, Mert

2016-01-01

Supporting the increase of environmental consciousness with environmental education is always important in order to make healthy recommendations specific to the countries. Aim of this study is to determine the awareness and consciousness of the local community against the environmental pollution caused by the CMC mine by survey technique. 123…

Renormalization group in statistical physics - momentum and real spaces

International Nuclear Information System (INIS)

Yukalov, V.I.

1988-01-01

Two variants of the renormalization group approach in statistical physics are considered, the renormalization group in the momentum and the renormalization group in the real spaces. Common properties of these methods and their differences are cleared up. A simple model for investigating the crossover between different universality classes is suggested. 27 refs

Groups, matrices, and vector spaces a group theoretic approach to linear algebra

CERN Document Server

Carrell, James B

2017-01-01

This unique text provides a geometric approach to group theory and linear algebra, bringing to light the interesting ways in which these subjects interact. Requiring few prerequisites beyond understanding the notion of a proof, the text aims to give students a strong foundation in both geometry and algebra. Starting with preliminaries (relations, elementary combinatorics, and induction), the book then proceeds to the core topics: the elements of the theory of groups and fields (Lagrange's Theorem, cosets, the complex numbers and the prime fields), matrix theory and matrix groups, determinants, vector spaces, linear mappings, eigentheory and diagonalization, Jordan decomposition and normal form, normal matrices, and quadratic forms. The final two chapters consist of a more intensive look at group theory, emphasizing orbit stabilizer methods, and an introduction to linear algebraic groups, which enriches the notion of a matrix group. Applications involving symm etry groups, determinants, linear coding theory ...

Spatially distributed damage detection in CMC thermal protection materials using thin-film piezoelectric sensors

Science.gov (United States)

Kuhr, Samuel J.; Blackshire, James L.; Na, Jeong K.

2009-03-01

Thermal protection systems (TPS) of aerospace vehicles are subjected to impacts during in-flight use and vehicle refurbishment. The damage resulting from such impacts can produce localized regions that are unable to resist extreme temperatures. Therefore it is essential to have a reliable method to detect, locate, and quantify the damage occurring from such impacts. The objective of this research is to demonstrate a capability that could lead to detecting, locating and quantifying impact events for ceramic matrix composite (CMC) wrapped tile TPS via sensors embedded in the TPS material. Previous research had shown a correlation between impact energies, material damage state, and polyvinylidene fluoride (PVDF) sensor response for impact energies between 0.07 - 1.00 Joules, where impact events were located directly over the sensor positions1. In this effort, the effectiveness of a sensor array is evaluated for detecting and locating low energy impacts on a CMC wrapped TPS. The sensor array, which is adhered to the internal surface of the TPS tile, is used to detect low energy impact events that occur at different locations. The analysis includes an evaluation of signal amplitude levels, time-of-flight measurements, and signal frequency content. Multiple impacts are performed at each location to study the repeatability of each measurement.

All-Ceramic Body Flap Qualified for Space Flight on X38

Science.gov (United States)

Pfeiffer, H.; Peetz, K.

2002-01-01

Ceramic matrix composite (CMC) materials allow design of high-temperature resistant, light and robust structures. CMC materials with silicon-carbide matrix reinforced by carbon fibers (C/SiC) show constant strength and damage-tolerant behavior up to very high temperatures. CMC thermal protection systems and hot structures have been developed in Europe over many years. MAN Technologie developed the necessary technologies to create the technological basis for CMC structures for future, more economical and reusable launch vehicles. Within the German space technology program TETRA (Technologies for Future Space Transportation Systems) body flaps were developed for X-38 by MAN Technologie. Key technologies like high strength oxidation protected CMC materials, manufacturing processes for large and complex structures, advanced high temperature lubricant coating combinations for bearings, joining with ceramic fasteners, metal-to-ceramic interfaces as well as dynamic seals are required for hot structures like control surfaces for re-entry vehicles. Because of the high heat and mechanical loads of a lifting body together with the low mass requirements the body flaps for NASA's X-38 re-entry vehicle V-201were selected to demonstrate as a first flight maturity of a large and complex ceramic structure. The flaps are designed as an all-ceramic, load-carrying hot structure, which needs no heavy metallic primary structure and no additional thermal protection tiles and subsequently offers considerable mass and volume savings. The X-38 body flaps are conceived as a revolutionary step forward. The twin flaps, each with the size of 1.6 m x 1.4 m (5.25 ft x 4.6 ft) and the low weight of 68 kg (150 lb) are all made of C/SiC material to operate up to temperatures of 1800 C (3.270 F) in oxidizing atmosphere while they are deflectable under high mechanical loads up to 50 kN (11.260 lbf) at the same time. The flaps are deflected about the hinge axis on two ceramic bearings and moved by an

System theory on group manifolds and coset spaces.

Science.gov (United States)

Brockett, R. W.

1972-01-01

The purpose of this paper is to study questions regarding controllability, observability, and realization theory for a particular class of systems for which the state space is a differentiable manifold which is simultaneously a group or, more generally, a coset space. We show that it is possible to give rather explicit expressions for the reachable set and the set of indistinguishable states in the case of autonomous systems. We also establish a type of state space isomorphism theorem. Our objective is to reduce all questions about the system to questions about Lie algebras generated from the coefficient matrices entering in the description of the system and in that way arrive at conditions which are easily visualized and tested.

Establishing an Empirical Link between Computer-Mediated Communication (CMC) and SLA: A Meta-Analysis of the Research

Science.gov (United States)

Lin, Huifen

2014-01-01

Drawing on interactionist and socio-cultural theories, tools provided in computer-mediated communication (CMC) environments have long been considered able to create an environment that shares many communicative features with face-to-face communication. Over the past two decades, researchers have employed a variety of strategies to examine the…

Derivation of space groups in mm2, 222 and mmm crystal classes

International Nuclear Information System (INIS)

Nigam, G.D.

1987-08-01

An algebraic approach is developed to derive space groups using 4x4 Seitz matrices for the crystal classes mm2, 222 and mmm in the orthorhombic system. The advantage of the present method is that it is relatively simple and can be adapted to introduce space groups to beginners. One of the advantages of the present method is that it admits a geometrical visualization of the symmetry elements of space group. The method can easily be extended to other crystal classes in a straightforward way. 16 refs, 1 fig., 2 tabs

Johnson Space Center's Risk and Reliability Analysis Group 2008 Annual Report

Science.gov (United States)

Valentine, Mark; Boyer, Roger; Cross, Bob; Hamlin, Teri; Roelant, Henk; Stewart, Mike; Bigler, Mark; Winter, Scott; Reistle, Bruce; Heydorn,Dick

2009-01-01

The Johnson Space Center (JSC) Safety & Mission Assurance (S&MA) Directorate s Risk and Reliability Analysis Group provides both mathematical and engineering analysis expertise in the areas of Probabilistic Risk Assessment (PRA), Reliability and Maintainability (R&M) analysis, and data collection and analysis. The fundamental goal of this group is to provide National Aeronautics and Space Administration (NASA) decisionmakers with the necessary information to make informed decisions when evaluating personnel, flight hardware, and public safety concerns associated with current operating systems as well as with any future systems. The Analysis Group includes a staff of statistical and reliability experts with valuable backgrounds in the statistical, reliability, and engineering fields. This group includes JSC S&MA Analysis Branch personnel as well as S&MA support services contractors, such as Science Applications International Corporation (SAIC) and SoHaR. The Analysis Group s experience base includes nuclear power (both commercial and navy), manufacturing, Department of Defense, chemical, and shipping industries, as well as significant aerospace experience specifically in the Shuttle, International Space Station (ISS), and Constellation Programs. The Analysis Group partners with project and program offices, other NASA centers, NASA contractors, and universities to provide additional resources or information to the group when performing various analysis tasks. The JSC S&MA Analysis Group is recognized as a leader in risk and reliability analysis within the NASA community. Therefore, the Analysis Group is in high demand to help the Space Shuttle Program (SSP) continue to fly safely, assist in designing the next generation spacecraft for the Constellation Program (CxP), and promote advanced analytical techniques. The Analysis Section s tasks include teaching classes and instituting personnel qualification processes to enhance the professional abilities of our analysts

Differential calculus on quantum spaces and quantum groups

International Nuclear Information System (INIS)

Zumino, B.

1992-01-01

A review of recent developments in the quantum differential calculus. The quantum group GL q (n) is treated by considering it as a particular quantum space. Functions on SL q (n) are defined as a subclass of functions on GL q (n). The case of SO q (n) is also briefly considered. These notes cover part of a lecture given at the XIX International Conference on Group Theoretic Methods in Physics, Salamanca, Spain 1992

The crystallographic space groups and Heterotic string theory

International Nuclear Information System (INIS)

El Naschie, M.S.

2009-01-01

While the 17 planar crystallographic groups were shown to correspond to 17 two and three Stein spaces with a total dimension equal to DimE12=5α-bar o ≅685, the present work reveals that the corresponding 219 three dimensional groups leads to a total dimensionality equal to N o ≅8872 which happens to be the exact total number of massless states of the transfinite version of Heterotic super string spectrum.

Teasing apart the effect of visibility and physical co-presence to examine the effect of CMC on interpersonal attraction

NARCIS (Netherlands)

Croes, Emmelyn; Antheunis, Marjolijn; Schouten, Alexander; Krahmer, Emiel

2016-01-01

This study analyzed the possible difference in interpersonal attraction between communicators in cue-rich computer-mediated communication (CMC) and face-to-face (FtF) communication. The first aim was to determine whether physical co-presence and visibility may account for differences in

TU-AB-BRC-02: Accuracy Evaluation of GPU-Based OpenCL Carbon Monte Carlo Package (goCMC) in Biological Dose and Microdosimetry in Comparison to FLUKA Simulations

Energy Technology Data Exchange (ETDEWEB)

Taleei, R; Peeler, C; Qin, N; Jiang, S; Jia, X [UT Southwestern Medical Center, Dallas, TX (United States)

2016-06-15

Purpose: One of the most accurate methods for radiation transport is Monte Carlo (MC) simulation. Long computation time prevents its wide applications in clinic. We have recently developed a fast MC code for carbon ion therapy called GPU-based OpenCL Carbon Monte Carlo (goCMC) and its accuracy in physical dose has been established. Since radiobiology is an indispensible aspect of carbon ion therapy, this study evaluates accuracy of goCMC in biological dose and microdosimetry by benchmarking it with FLUKA. Methods: We performed simulations of a carbon pencil beam with 150, 300 and 450 MeV/u in a homogeneous water phantom using goCMC and FLUKA. Dose and energy spectra for primary and secondary ions on the central beam axis were recorded. Repair-misrepair-fixation model was employed to calculate Relative Biological Effectiveness (RBE). Monte Carlo Damage Simulation (MCDS) tool was used to calculate microdosimetry parameters. Results: Physical dose differences on the central axis were <1.6% of the maximum value. Before the Bragg peak, differences in RBE and RBE-weighted dose were <2% and <1%. At the Bragg peak, the differences were 12.5% caused by small range discrepancy and sensitivity of RBE to beam spectra. Consequently, RBE-weighted dose difference was 11%. Beyond the peak, RBE differences were <20% and primarily caused by differences in the Helium-4 spectrum. However, the RBE-weighted dose agreed within 1% due to the low physical dose. Differences in microdosimetric quantities were small except at the Bragg peak. The simulation time per source particle with FLUKA was 0.08 sec, while goCMC was approximately 1000 times faster. Conclusion: Physical doses computed by FLUKA and goCMC were in good agreement. Although relatively large RBE differences were observed at and beyond the Bragg peak, the RBE-weighted dose differences were considered to be acceptable.

COSTANZA, 1-D 2 Group Space-Dependent Reactor Dynamics of Spatial Reactor with 1 Group Delayed Neutrons

International Nuclear Information System (INIS)

Agazzi, A.; Gavazzi, C.; Vincenti, E.; Monterosso, R.

1964-01-01

1 - Nature of physical problem solved: The programme studies the spatial dynamics of reactor TESI, in the two group and one space dimension approximation. Only one group of delayed neutrons is considered. The programme simulates the vertical movement of the control rods according to any given movement law. The programme calculates the evolution of the fluxes and temperature and precursor concentration in space and time during the power excursion. 2 - Restrictions on the complexity of the problem: The maximum number of lattice points is 100

A CMC database for use in the next generation launch vehicles (rockets)

Science.gov (United States)

Mahanta, Kamala

1994-01-01

Ceramic matrix composites (CMC's) are being envisioned as the state-of-the-art material capable of handling the tough structural and thermal demands of advanced high temperature structures for programs such as the SSTO (Single Stage to Orbit), HSCT (High Speed Civil Transport), etc. as well as for evolution of the industrial heating systems. Particulate, whisker and continuous fiber ceramic matrix (CFCC) composites have been designed to provide fracture toughness to the advanced ceramic materials which have a high degree of wear resistance, hardness, stiffness, and heat and corrosion resistance but are notorious for their brittleness and sensitivity to microscopic flaws such as cracks, voids and impurity.

Crystallographic and magnetic structure of the novel compound ErGe 1.83

Science.gov (United States)

Oleksyn, O.; Schobinger-Papamantellos, P.; Ritter, C.; de Groot, C. H.; Buschow, K. H. J.

1997-02-01

The crystal structure and the magnetic ordering of the novel orthorhombic compound ErGe 2-x has been studied by neutron powder diffraction and magnetic measurements. The crystal structure belongs to the DyGe 1.85-type (space group Cmc2 1)·ErGe 2-x ( x = 0.17 (2)) orders antiferromagnetically below TN = 6 K and displays a metamagnetic behaviour. The magnetic cell has the same size as the chemical unit cell ( q = 0 ). The magnetic space group is Cmc2 1 (Sh 36173). At T = 1.5 K the magnetic moments of the two erbium sites have the same ordered magnetic moment values of 7.63 (6) μB/Er and are antiferromagnetically coupled leading to an uniaxial structure along the a direction.

On the Chabauty space of locally compact abelian groups

OpenAIRE

Cornulier, Yves

2010-01-01

This paper contains several results about the Chabauty space of a general locally compact abelian group. Notably, we determine its topological dimension, we characterize when it is totally disconnected or connected; we characterize isolated points.

Toward a standardized structural-functional group connectome in MNI space.

Science.gov (United States)

Horn, Andreas; Blankenburg, Felix

2016-01-01

The analysis of the structural architecture of the human brain in terms of connectivity between its subregions has provided profound insights into its underlying functional organization and has coined the concept of the "connectome", a structural description of the elements forming the human brain and the connections among them. Here, as a proof of concept, we introduce a novel group connectome in standard space based on a large sample of 169 subjects from the Enhanced Nathan Kline Institute-Rockland Sample (eNKI-RS). Whole brain structural connectomes of each subject were estimated with a global tracking approach, and the resulting fiber tracts were warped into standard stereotactic (MNI) space using DARTEL. Employing this group connectome, the results of published tracking studies (i.e., the JHU white matter and Oxford thalamic connectivity atlas) could be largely reproduced directly within MNI space. In a second analysis, a study that examined structural connectivity between regions of a functional network, namely the default mode network, was reproduced. Voxel-wise structural centrality was then calculated and compared to others' findings. Furthermore, including additional resting-state fMRI data from the same subjects, structural and functional connectivity matrices between approximately forty thousand nodes of the brain were calculated. This was done to estimate structure-function agreement indices of voxel-wise whole brain connectivity. Taken together, the combination of a novel whole brain fiber tracking approach and an advanced normalization method led to a group connectome that allowed (at least heuristically) performing fiber tracking directly within MNI space. Such an approach may be used for various purposes like the analysis of structural connectivity and modeling experiments that aim at studying the structure-function relationship of the human connectome. Moreover, it may even represent a first step toward a standard DTI template of the human brain

Potential of L-fucose isolated from Brown Seaweeds as Promising Natural Emulsifier compare to Carboxymethyl Cellulose (CMC)

Science.gov (United States)

Al-Baarri, A. N.; Legowo, A. M.; Widayat; Abduh, S. B. M.; Lestari, F. P.; Desnasari, D.; Santoso, I. P. M.

2018-02-01

L-fucose has been understood as sulfated polysaccharides and it could be extracted and fractionated from brown algae. These polysaccharides contains carbohydrate, sulfate, and protein that may be used as emulsifier. This research was aimed to study the emulsification properties of L-fucose through the determination of total dissolved solids (TDS), color CIE L*a*b* and stability of oil-in-water emulsion. As much as 0.5% of high concentrated L-fucose and 0.5% of carboxymethyl cellulose (CMC) were used as emulsifier in a 10% (v/v) oil-in-water (O/W) emulsion. The emulsifier was added to O/W emulsions and then heated at 72°C. Result of stability emulsion and TDS showed that L-fucose was comparable to the CMC but remarkable changed the color of O/W emulsion. Heating process significantly reduced the stability O/W emulsion when L-fucose was applied. As conclusion, L-fucose might be used as natural emulsifier in O/W emulsion but in the low heat treatment of food processing. This study may provide valuable information for utilizing natural emulsifier from abundant resources from nature.

Thickness and Closure Kinetics of the Suprachoroidal Space Following Microneedle Injection of Liquid Formulations.

Science.gov (United States)

Chiang, Bryce; Venugopal, Nitin; Grossniklaus, Hans E; Jung, Jae Hwan; Edelhauser, Henry F; Prausnitz, Mark R

2017-01-01

To determine the effect of injection volume and formulation of a microneedle injection into the suprachoroidal space (SCS) on SCS thickness and closure kinetics. Microneedle injections containing 25 to 150 μL Hanks' balanced salt solution (HBSS) were performed in the rabbit SCS ex vivo. Distribution of SCS thickness was measured by ultrasonography and three-dimensional (3D) cryo-reconstruction. Microneedle injections were performed in the rabbit SCS in vivo using HBSS, Discovisc, and 1% to 5% carboxymethyl cellulose (CMC) in HBSS. Ultrasonography was used to track SCS thickness over time. Increasing HBSS injection volume increased the area of expanded SCS, but did not increase SCS thickness ex vivo. With SCS injections in vivo, the SCS initially expanded to thicknesses of 0.43 ± 0.06 mm with HBSS, 1.5 ± 0.4 mm with Discovisc, and 0.69 to 2.1 mm with 1% to 5% CMC. After injection with HBSS, Discovisc, and 1% CMC solution, the SCS collapsed to baseline with time constants of 19 minutes, 6 hours, and 2.4 days, respectively. In contrast, injections with 3% to 5% CMC solution resulted in SCS expansion to 2.3 to 2.8 mm over the course of 2.8 to 9.1 hours, after which the SCS collapsed to baseline with time constants of 4.5 to 9.2 days. With low-viscosity formulations, SCS expands to a thickness that remains roughly constant, independent of the volume of fluid injected. Increasing injection fluid viscosity significantly increased SCS thickness. Expansion of the SCS is hypothesized to be controlled by a balance between the viscous forces of the liquid formulation and the resistive biomechanical forces of the tissue.

An introduction to Lie groups and the geometry of homogeneous spaces

CERN Document Server

Arvanitoyeorgos, Andreas

2003-01-01

It is remarkable that so much about Lie groups could be packed into this small book. But after reading it, students will be well-prepared to continue with more advanced, graduate-level topics in differential geometry or the theory of Lie groups. The theory of Lie groups involves many areas of mathematics. In this book, Arvanitoyeorgos outlines enough of the prerequisites to get the reader started. He then chooses a path through this rich and diverse theory that aims for an understanding of the geometry of Lie groups and homogeneous spaces. In this way, he avoids the extra detail needed for a thorough discussion of other topics. Lie groups and homogeneous spaces are especially useful to study in geometry, as they provide excellent examples where quantities (such as curvature) are easier to compute. A good understanding of them provides lasting intuition, especially in differential geometry. The book is suitable for advanced undergraduates, graduate students, and research mathematicians interested in differenti...

Determining sociability, social space, and social presence in (a)synchronous collaborative groups.

Science.gov (United States)

Kreijns, Karel; Kirschner, Paul A; Jochems, Wim; Van Buuren, Hans

2004-04-01

The effectiveness of group learning in asynchronous distributed learning groups depends on the social interaction that takes place. This social interaction affects both cognitive and socioemotional processes that take place during learning, group forming, establishment of group structures, and group dynamics. Though now known to be important, this aspect is often ignored, denied or forgotten by educators and researchers who tend to concentrate on cognitive processes and on-task contexts. This "one-sided" educational focus largely determines the set of requirements in the design of computer-supported collaborative learning (CSCL) environments resulting in functional CSCL environments. In contrast, our research is aimed at the design and implementation of sociable CSCL environments which may increase the likelihood that a sound social space will emerge. We use a theoretical framework that is based upon an ecological approach to social interaction, centering on the concept of social affordances, the concept of the sociability of CSCL environments, and social presence theory. The hypothesis is that the higher the sociability, the more likely that social interaction will take place or will increase, and the more likely that this will result in an emerging sound social space. In the present research, the variables of interest are sociability, social space, and social presence. This study deals with the construction and validation of three instruments to determine sociability, social space, and social presence in (a)synchronous collaborating groups. The findings suggest that the instruments have potential to be useful as measures for the respective variables. However, it must be realized that these measures are "first steps."

The homology groups of moduli spaces on non-classical Klein surfaces

International Nuclear Information System (INIS)

Zaw, Myint

2001-08-01

We describe the moduli space M-vector±(g,c) of non-classical directed Klein surfaces of genus g=h-c-1 with c≥0 distinguished points as a configuration space B ± (h,c) of classes h-slit pairs in C. Based on this model, we prove that M-vector ± (g,c) is non-orientable for any g and c and we compute the homology groups of the moduli spaces M-vector ± (g,c) for g≤2. (author)

Representation of SO(4,1) group and Hawking effect in the de-Sitter space

International Nuclear Information System (INIS)

Bogush, A.A.; Otchik, V.S.

1983-01-01

Expression relating the solution of the equation for particles with spin 1/2 to matrix elements of group SO(4, 1), is obtained. When using the relation of the Dirac equation solutions in the de Sitter space with matrix elements of representations of group SO(4, 1) the presence of the Hawking effect in the space is established. The de Sitter space is considered as 4-dimensional hyperboloid, inserted into 5-dimensional pseudo-Euclidean space. It is established, that the average number of emitted spinor particles obeys the Fermi-Dirac distribution

The optimization of CMC concentration as graphite binder on the anode of LiFePO4 battery

Science.gov (United States)

Hidayat, S.; Cahyono, T.; Mindara, J. Y.; Riveli, N.; Alamsyah, W.; Rahayu, I.

2017-05-01

Recently, the most dominating power supply on the mobile electronics market are rechargeable Lithium-ion batteries. This is because of a higher energy density and a longer lifetime compared to similar rechargeable battery systems. Graphite is commonly used as anode material in the Lithium-ion batteries, because of its excellent electrochemical characteristics and low cost fabrication. In this paper, we reported the optimization of the concentration of the CMC (carboxymethyl cellulose), that acts as the binder for graphite anode. Based on our experimental results, the best composition of graphite : C : CMC is 90 : 8 : 2 in weight %. Anode with such composition has, based on SEM measurement, a relatively good surface morphology, while it also has relatively high conductivity, about 2.68 S/cm. The result of cyclic voltammogram with a scan rate of 10 mV/s in the voltage range of 0 to 1 Volt, shows the peak of reduction voltage at 0.85 Volts and the peak voltage of oxidation is at -1.5 Volt. The performance of the battery system with LiFePO4 set as the cathode, shows that the working voltage is about 2.67 Volts at 1 mA current-loading, with the efficiency around 47%.

Working Group 2 summary: Space charge effects in bending systems

International Nuclear Information System (INIS)

Bohn, C.L.; Emma, P.J.

2000-01-01

At the start of the Workshop, the authors asked the Working Group 2 participants to concentrate on three basic goals: (1) survey the status of how comprehensively the physics concerning space-charge effects in bends is understood and how complete is the available ensemble of analytic and computational tools; (2) guided by data from experiments and operational experience, identify sources of, and cures for, beam degradation; and (3) review space-charge physics in rings and the limitations it introduces. As the Workshop unfolded, the third goal naturally folded into the other two goals, and these goals, they believe, were fulfilled in that the Working Group was able to compile an end product consisting of a set of recommendations for potentially fruitful future work. This summary constitutes an overview of the deliberations of the Working Group, and it is their hope that the summary clarifies the motivation for the recommended work listed at the end. The summary is organized according to the two aforementioned goals, and the prime topics of discussion appear as subsections under these goals

Challenges in Teaching Space Physics to Different Target Groups From Space Weather Forecasters to Heavy-weight Theorists

Science.gov (United States)

Koskinen, H. E.

2008-12-01

Plasma physics as the backbone of space physics is difficult and thus the space physics students need to have strong foundations in general physics, in particular in classical electrodynamics and thermodynamics, and master the basic mathematical tools for physicists. In many universities the number of students specializing in space physics at Master's and Doctoral levels is rather small and the students may have quite different preferences ranging from experimental approach to hard-core space plasma theory. This poses challenges in building up a study program that has both the variety and depth needed to motivate the best students to choose this field. At the University of Helsinki we require all beginning space physics students, regardless whether they enter the field as Master's or Doctoral degree students, to take a one-semester package consisting of plasma physics and its space applications. However, some compromises are necessary. For example, it is not at all clear, how thoroughly Landau damping should be taught at the first run or how deeply should the intricacies of collisionless reconnection be discussed. In both cases we have left the details to an optional course in advanced space physics, even with the risk that the student's appreciation of, e.g., reconnection may remain at the level of a magic wand. For learning experimental work, data analysis or computer simulations we have actively pursued arrangements for the Master's degree students to get a summer employments in active research groups, which usually lead to the Master's theses. All doctoral students are members of research groups and participate in experimental work, data analysis, simulation studies or theory development, or any combination of these. We emphasize strongly "learning by doing" all the way from the weekly home exercises during the lecture courses to the PhD theses which in Finland consist typically of 4-6 peer-reviewed articles with a comprehensive introductory part.

Real-space renormalization group approach to driven diffusive systems

Energy Technology Data Exchange (ETDEWEB)

Hanney, T [SUPA and School of Physics, University of Edinburgh, Mayfield Road, Edinburgh, EH9 3JZ (United Kingdom); Stinchcombe, R B [Theoretical Physics, 1 Keble Road, Oxford, OX1 3NP (United Kingdom)

2006-11-24

We introduce a real-space renormalization group procedure for driven diffusive systems which predicts both steady state and dynamic properties. We apply the method to the boundary driven asymmetric simple exclusion process and recover exact results for the steady state phase diagram, as well as the crossovers in the relaxation dynamics for each phase.

Real-space renormalization group approach to driven diffusive systems

International Nuclear Information System (INIS)

Hanney, T; Stinchcombe, R B

2006-01-01

We introduce a real-space renormalization group procedure for driven diffusive systems which predicts both steady state and dynamic properties. We apply the method to the boundary driven asymmetric simple exclusion process and recover exact results for the steady state phase diagram, as well as the crossovers in the relaxation dynamics for each phase

Förster Resonance Energy Transfer (FRET) from Triton X-100 to 4-benzothiazol-2-yl-phenol: Varying FRET efficiency with CMC of the donor (Triton X-100)

International Nuclear Information System (INIS)

Paul, Bijan Kumar; Ganguly, Aniruddha; Karmakar, Saswati; Guchhait, Nikhil

2013-01-01

A heterocyclic compound viz., 4-benzothiazol-2-yl-phenol (4B2YP) has been synthesized and its photophysics have been examined through steady-state absorption, emission and time resolved emission spectroscopic techniques, in brief. Then 4B2YP has been exploited as an acceptor in the Förster Resonance Energy Transfer (FRET) process from photoexcited benzene aromatic nucleus of Triton X-100 (TX-100) surfactant. Dependence of the energy transfer efficiency on the donor concentration with respect to its critical micelle concentration (CMC) is clearly reflected in the study. High values of Stern–Volmer constant (K SV ) for quenching of the donor fluorescence in the presence of the acceptor suggest the operation of long-range dipole–dipole interaction in the course of energy transfer process, while the inference is aptly supported from time resolved fluorescence decay results. Experimental results show maximum FRET efficiency at the CMC of the donor (TX-100). -- Highlights: • FRET from neutral surfactant Triton X-100 to chromophore 4-benzothiazol-2-yl-phenol. • Steady state and time resolved spectroscopy. • Long-range dipole–dipole interaction responsible for FRET. • FRET efficiency as a measure of CMC of surfactant

Förster Resonance Energy Transfer (FRET) from Triton X-100 to 4-benzothiazol-2-yl-phenol: Varying FRET efficiency with CMC of the donor (Triton X-100)

Energy Technology Data Exchange (ETDEWEB)

Paul, Bijan Kumar, E-mail: bijan.paul.chem.cu@gmail.com [Department of Chemistry, University of Calcutta, 92 A.P.C. Road, Calcutta 700009 (India); Ganguly, Aniruddha [Department of Chemistry, University of Calcutta, 92 A.P.C. Road, Calcutta 700009 (India); Karmakar, Saswati [Department of Chemistry, Sree Chaitanya College, Habra, North 24 Parganas (India); Guchhait, Nikhil, E-mail: nguchhait@yahoo.com [Department of Chemistry, University of Calcutta, 92 A.P.C. Road, Calcutta 700009 (India)

2013-11-15

A heterocyclic compound viz., 4-benzothiazol-2-yl-phenol (4B2YP) has been synthesized and its photophysics have been examined through steady-state absorption, emission and time resolved emission spectroscopic techniques, in brief. Then 4B2YP has been exploited as an acceptor in the Förster Resonance Energy Transfer (FRET) process from photoexcited benzene aromatic nucleus of Triton X-100 (TX-100) surfactant. Dependence of the energy transfer efficiency on the donor concentration with respect to its critical micelle concentration (CMC) is clearly reflected in the study. High values of Stern–Volmer constant (K{sub SV}) for quenching of the donor fluorescence in the presence of the acceptor suggest the operation of long-range dipole–dipole interaction in the course of energy transfer process, while the inference is aptly supported from time resolved fluorescence decay results. Experimental results show maximum FRET efficiency at the CMC of the donor (TX-100). -- Highlights: • FRET from neutral surfactant Triton X-100 to chromophore 4-benzothiazol-2-yl-phenol. • Steady state and time resolved spectroscopy. • Long-range dipole–dipole interaction responsible for FRET. • FRET efficiency as a measure of CMC of surfactant.

Generation of symmetry coordinates for crystals using multiplier representations of the space groups

DEFF Research Database (Denmark)

Hansen, Flemming Yssing

1978-01-01

Symmetry coordinates play an important role in the normal-mode calculations of crystals. It is therefore of great importance to have a general method, which may be applied for any crystal at any wave vector, to generate these. The multiplier representations of the space groups as given by Kovalev...... and the projection-operator technique provide a basis for such a method. The method is illustrated for the nonsymmorphic D36 space group, and the theoretical background for the representations of space groups in general is reviewed and illustrated on the example above. It is desirable to perform the projection...... of symmetry coordinates in such a way that they may be used for as many wave vectors as possible. We discuss how to achieve this goal. The detailed illustrations should make it simple to apply the theory in any other case....

A geometric renormalization group in discrete quantum space-time

International Nuclear Information System (INIS)

Requardt, Manfred

2003-01-01

We model quantum space-time on the Planck scale as dynamical networks of elementary relations or time dependent random graphs, the time dependence being an effect of the underlying dynamical network laws. We formulate a kind of geometric renormalization group on these (random) networks leading to a hierarchy of increasingly coarse-grained networks of overlapping lumps. We provide arguments that this process may generate a fixed limit phase, representing our continuous space-time on a mesoscopic or macroscopic scale, provided that the underlying discrete geometry is critical in a specific sense (geometric long range order). Our point of view is corroborated by a series of analytic and numerical results, which allow us to keep track of the geometric changes, taking place on the various scales of the resolution of space-time. Of particular conceptual importance are the notions of dimension of such random systems on the various scales and the notion of geometric criticality

Fundamental group of dual graphs and applications to quantum space time

International Nuclear Information System (INIS)

Nada, S.I.; Hamouda, E.H.

2009-01-01

Let G be a connected planar graph with n vertices and m edges. It is known that the fundamental group of G has 1 -(n - m) generators. In this paper, we show that if G is a self-dual graph, then its fundamental group has (n - 1) generators. We indicate that these results are relevant to quantum space time.

Utilización de lactosuero de queso fresco en la elaboración de una bebida fermentada con adición de pulpa maracuyá (passiflora edulis) variedad púrpura y carbóximetil celulosa (cmc), enriquecida con vitaminas A y D.

OpenAIRE

Sepúlveda Valencia José Uriel; Flórez Flórez Luis Eduardo; Peña Álvarez Claudia Milena

2002-01-01

Se puede obtener una bebida con características especiales a partir de la fermentación de suero de queso fresco, en presencia de Streptococcus thermophillus y Lactobacillus bulgaricus, comparable con un yogur tradicional. Se utilizaron 150 kg de lactosuero de queso fresco, a cada muestra de 50 kg se le aplicó un tratamiento con estabilizantes comerciales cuya base es carboximetilcelulosa (CMC 27 FG, CMC 28FG y CMC 29FG), cuya función es conferir viscosidad. La bebida que se desarrolló a...

Validation of missed space-group symmetry in X-ray powder diffraction structures with dispersion-corrected density functional theory.

Science.gov (United States)

Hempler, Daniela; Schmidt, Martin U; van de Streek, Jacco

2017-08-01

More than 600 molecular crystal structures with correct, incorrect and uncertain space-group symmetry were energy-minimized with dispersion-corrected density functional theory (DFT-D, PBE-D3). For the purpose of determining the correct space-group symmetry the required tolerance on the atomic coordinates of all non-H atoms is established to be 0.2 Å. For 98.5% of 200 molecular crystal structures published with missed symmetry, the correct space group is identified; there are no false positives. Very small, very symmetrical molecules can end up in artificially high space groups upon energy minimization, although this is easily detected through visual inspection. If the space group of a crystal structure determined from powder diffraction data is ambiguous, energy minimization with DFT-D provides a fast and reliable method to select the correct space group.

CFCC working group meeting: Proceedings

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

This report is a compilation of the vugraphs presented at this meeting. Presentations covered are: CFCC Working Group; Overview of study on applications for advanced ceramics in industries for the future; Design codes and data bases: The CFCC program and its involvement in ASTM, ISO, ASME, and military handbook 17 activities; CFCC Working Group meeting (McDermott Technology); CFCC Working Group meeting (Textron); CFCC program for DMO materials; Developments in PIP-derived CFCCs; Toughened Silcomp (SiC-Si) composites for gas turbine engine applications; CFCC program for CVI materials; Self-lubricating CFCCs for diesel engine applications; Overview of the CFCC program`s supporting technologies task; Life prediction methodologies for CFCC components; Environmental testing of CFCCs in combustion gas environments; High-temperature particle filtration ORNL/DCC CRADA; HSCT CMC combustor; and Case study -- CFCC shroud for industrial gas turbines.

The Picard group of the moduli space of r-Spin Riemann surfaces

DEFF Research Database (Denmark)

Randal-Williams, Oscar

2012-01-01

An r-Spin Riemann surface is a Riemann surface equipped with a choice of rth root of the (co)tangent bundle. We give a careful construction of the moduli space (orbifold) of r-Spin Riemann surfaces, and explain how to establish a Madsen–Weiss theorem for it. This allows us to prove the “Mumford...... conjecture” for these moduli spaces, but more interestingly allows us to compute their algebraic Picard groups (for g≥10, or g≥9 in the 2-Spin case). We give a complete description of these Picard groups, in terms of explicitly constructed line bundles....

A primer on Hilbert space theory linear spaces, topological spaces, metric spaces, normed spaces, and topological groups

CERN Document Server

Alabiso, Carlo

2015-01-01

This book is an introduction to the theory of Hilbert space, a fundamental tool for non-relativistic quantum mechanics. Linear, topological, metric, and normed spaces are all addressed in detail, in a rigorous but reader-friendly fashion. The rationale for an introduction to the theory of Hilbert space, rather than a detailed study of Hilbert space theory itself, resides in the very high mathematical difficulty of even the simplest physical case. Within an ordinary graduate course in physics there is insufficient time to cover the theory of Hilbert spaces and operators, as well as distribution theory, with sufficient mathematical rigor. Compromises must be found between full rigor and practical use of the instruments. The book is based on the author's lessons on functional analysis for graduate students in physics. It will equip the reader to approach Hilbert space and, subsequently, rigged Hilbert space, with a more practical attitude. With respect to the original lectures, the mathematical flavor in all sub...

Convergent-beam electron diffraction study of incommensurately modulated crystals. Pt. 2. (3 + 1)-dimensional space groups

International Nuclear Information System (INIS)

Terauchi, Masami; Takahashi, Mariko; Tanaka, Michiyoshi

1994-01-01

The convergent-beam electron diffraction (CBED) method for determining three-dimensional space groups is extended to the determination of the (3 + 1)-dimensional space groups for one-dimensional incommensurately modulated crystals. It is clarified than an approximate dynamical extinction line appears in the CBED discs of the reflections caused by an incommensurate modulation. The extinction enables the space-group determination of the (3 + 1)-dimensional crystals or the one-dimensional incommensurately modulated crystals. An example of the dynamical extinction line is shown using an incommensurately modulated crystal of Sr 2 Nb 2 O 7 . Tables of the dynamical extinction lines appearing in CBED patterns are given for all the (3 + 1)-dimensional space groups of the incommensurately modulated crystal. (orig.)

An introduction to data reduction: space-group determination, scaling and intensity statistics.

Science.gov (United States)

Evans, Philip R

2011-04-01

This paper presents an overview of how to run the CCP4 programs for data reduction (SCALA, POINTLESS and CTRUNCATE) through the CCP4 graphical interface ccp4i and points out some issues that need to be considered, together with a few examples. It covers determination of the point-group symmetry of the diffraction data (the Laue group), which is required for the subsequent scaling step, examination of systematic absences, which in many cases will allow inference of the space group, putting multiple data sets on a common indexing system when there are alternatives, the scaling step itself, which produces a large set of data-quality indicators, estimation of |F| from intensity and finally examination of intensity statistics to detect crystal pathologies such as twinning. An appendix outlines the scoring schemes used by the program POINTLESS to assign probabilities to possible Laue and space groups.

Drainage Behavior in Soap Films Above and Below the CMC

Science.gov (United States)

Berg, S.; Adelizzi, E. A.; Troian, S. M.

2003-11-01

We investigate through laser interferometry the drainage behavior of Newtonian soap films initially entrained on a fiber frame at small and constant capillary number. The initial film thickness is sufficiently small that gravitational drainage is presumed minimal. The drainage of rigid soap films by capillary forces alone should proceed according to h(t) ˜ t^- 1/2. Our experimental results show much more rapid drainage with exponents as large as -2, especially for those solutions whose surfactant concentrations are below the CMC. Video recordings of the entire film surface reveal a variety of structures during the drainage process, some attributable to marginal regeneration. Though still a controversial issue, this regeneration process is believed to be caused by surfactant accumulation in the meniscus region (1). We show that modification of the relevant capillary drainage equation to account for Marangoni effects through a course-grained slip condition at the air-liquid interface produces exponents in better agreement with experimental findings. (1) V. A. Nierstrasz and G. Frens, JCIS 215, 28 (1999).

Future In-Space Operations (FISO): A Working Group and Community Engagement

Science.gov (United States)

Thronson, Harley; Lester, Dan

2013-01-01

Long-duration human capabilities beyond low Earth orbit (LEO), either in support of or as an alternative to lunar surface operations, have been assessed at least since the late 1960s. Over the next few months, we will present short histories of concepts for long-duration, free-space human habitation beyond LEO from the end of the Apollo program to the Decadal Planning Team (DPT)/NASA Exploration Team (NExT), which was active in 1999 2000 (see Forging a vision: NASA s Decadal Planning Team and the origins of the Vision for Space Exploration , The Space Review, December 19, 2005). Here we summarize the brief existence of the Future In-Space Operations (FISO) working group in 2005 2006 and its successor, a telecon-based colloquium series, which we co-moderate.

Space-time versus world-sheet renormalization group equation in string theory

International Nuclear Information System (INIS)

Brustein, R.; Roland, K.

1991-05-01

We discuss the relation between space-time renormalization group equation for closed string field theory and world-sheet renormalization group equation for first-quantized strings. Restricting our attention to massless states we argue that there is a one-to-one correspondence between the fixed point solutions of the two renormalization group equations. In particular, we show how to extract the Fischler-Susskind mechanism from the string field theory equation in the case of the bosonic string. (orig.)

Bacterial community associated with the intestinal tract of Chinese mitten crab (Eriocheir sinensis farmed in Lake Tai, China.

Directory of Open Access Journals (Sweden)

Xiaobing Chen

Full Text Available Chinese mitten crab (CMC, Eriocheir sinensis is an economically valuable species in South-East Asia that has been widely farmed in China. Characterization of the intestinal bacterial diversity of CMC will provide insights into the aquaculturing of CMCs. Based on the analysis of cloned 16S rRNA genes from culture-independent CMC gut bacteria, 124 out of 128 different clones reveal ＞95% nucleotide similarity to the species belonging to the four phyla of Tenericutes, Bacteroidetes, Firmicutes and Proteobacteria; one clone shows 91% sequence similarity to the member of TM7 (a candidate phylum without cultured representatives. Fluorescent in situ hybridization also reveals the abundance of Bacteroidetes in crab intestine. Electron micrographs show that spherical and filamentous bacteria are closely associated with the microvillus brush border of the midgut epithelium and are often inserted into the space between the microvilli using a stalk-like cell appendage. In contrast, the predominant rod-shaped bacteria in the hindgut are tightly attached to the epithelium surface by an unusual pili-like structure. Both 16S rRNA gene denaturing gel gradient electrophoresis and metagenome library indicate that the CMC Mollicutes group 2 appears to be present in both the midgut and hindgut with no significant difference in abundance. The CMC Mollicutes group 1, however, was found mostly in the midgut of CMCs. The CMC gut Mollicutes phylotypes appear to be most closely related to Mollicutes symbionts detected in the gut of isopods (Crustacea: Isopoda. Overall, the results suggest that CMCs harbor diverse, novel and specific gut bacteria, which are likely to live in close relationships with the CMC host.

Utilización de lactosuero de queso fresco en la elaboración de una bebida fermentada con adición de pulpa maracuyá (passiflora edulis) variedad púrpura y carbóximetil celulosa (cmc), enriquecida con vitaminas a y d.

OpenAIRE

Sepúlveda Valencia, José Uriel; Flórez Flórez, Luis Eduardo; Peña Álvarez, Claudia Milena

2011-01-01

Se puede obtener una bebida con características especiales a partir de la fermentación de suero de queso fresco, en presencia de Streptococcus thermophillus y Lactobacillus bulgaricus, comparable con un yogur tradicional. Se utilizaron 150 kg de lactosuero de queso fresco, a cada muestra de 50 kg se le aplicó un tratamiento con estabilizantes comerciales cuya base es carboximetilcelulosa (CMC 27 FG, CMC 28FG y CMC 29FG), cuya función es conferir viscosidad. La bebida que se desarrolló a p...

Technologies That Assist in Online Group Work: A Comparison of Synchronous and Asynchronous Computer Mediated Communication Technologies on Students' Learning and Community

Science.gov (United States)

Rockinson-Szapkiw, Amanda; Wendt, Jillian

2015-01-01

While the benefits of online group work completed using asynchronous CMC technology is documented, researchers have identified a number of challenges that result in ineffective and unsuccessful online group work. Fewer channels of communication and lack of immediacy when compared to face-to-face group work are a few of the noted limitations. Thus,…

The Lp Spectrum of Locally Symmetric Spaces with Small Fundamental Group

International Nuclear Information System (INIS)

Weber, Andreas

2009-01-01

We determine the L p spectrum of the Laplace-Beltrami operator on certain complete locally symmetric spaces M whose universal covering X is a symmetric space of non-compact type with rank one. More precisely, we show that the L p spectra of M and X coincide if the fundamental group of M is small and if the injectivity radius of M is bounded away from zero. In the L 2 case, the restriction on the injectivity radius is not needed

Thermodynamics on the micellization of various pure and mixed surfactants: Effects of head- and tail-groups

International Nuclear Information System (INIS)

Lee, Nam-Min; Lee, Byung-Hwan

2016-01-01

Highlights: • The values of critical micelle concentration of various pure and mixed surfactants are measured. • Thermodynamic parameters’ values are calculated to analyze the effects of head- and tail-groups on the micellization. • All the thermodynamic parameters’ values are decreasing with the increase of temperature. • The thermodynamic parameters’ values are depending severely on the chain length of alkyl group. - Abstract: The values of critical micelle concentration (CMC) for the micellization of various pure and mixed surfactants are determined by the UV–Vis spectrophotometric method. And the effects of temperature on the CMC values have been measured and thermodynamic parameters’ values are calculated to analyse the effects of head- and tail-groups on the micellization of surfactant molecules. The results show that the values of ΔG"o are negative and those of ΔS"o are positive for the micellization of all the surfactants within the measured temperature range. But the values of ΔH"o are positive or negative, depending on the kinds of surfactants. All these thermodynamic parameters’ values are decreasing together with the increase of temperature for all the surfactants. And these thermodynamic parameters’ values are depending severely on the chain length of alkyl group also as much as on the head-groups of surfactant molecules.

Synthesis and controlling the optical and dielectric properties of CMC/PVA blend via γ-rays irradiation

Energy Technology Data Exchange (ETDEWEB)

El Sayed, A.M., E-mail: ams06@fayoum.edu.eg

2014-02-15

Highlights: • PVA/CMC blend films were prepared by solution casting method. • The films were irradiated with γ-rays at the dose range of 0–70 kGy. • UV-vis spectroscopy was performed to study the changes in the optical properties. • The influence of γ-rays irradiation on the dielectric relaxation was studied. -- Abstract: Carboxymethyl cellulose (CMC)/Polyvinyl alcohol (PVA) blend films were prepared by solution casting method. Then, these films were irradiated with γ-rays from a Co-60 source at doses over the range 0–70 kGy to investigate the modifications induced in the optical and dielectric properties. The dielectric constant (ε′) was measured in the temperature range 303–408 K and in the frequency range 10 kHz–1 MHz. The indirect optical band gap was found to increase within the dose range 0–10 kGy, and to decrease at the higher doses. The refractive index values, however, showed a reversed behavior. The highest transmittance percentage was obtained at 10 kGy dose. According to the frequency and temperature dependence of ε′, α- relaxation peaks were observed in all samples and assigned to the micro-Brownian motion of the blend chains. The values of ε′ showed a decrease in the dose range 0–10 kGy and an increase in the dose range 10–70 kGy. The ac conductivity σ{sub ac} (T) showed an Arrhenius type behavior separated into two distinct regions. The results of the present system are compared with those of similar materials.

Synthesis and controlling the optical and dielectric properties of CMC/PVA blend via γ-rays irradiation

International Nuclear Information System (INIS)

El Sayed, A.M.

2014-01-01

Highlights: • PVA/CMC blend films were prepared by solution casting method. • The films were irradiated with γ-rays at the dose range of 0–70 kGy. • UV-vis spectroscopy was performed to study the changes in the optical properties. • The influence of γ-rays irradiation on the dielectric relaxation was studied. -- Abstract: Carboxymethyl cellulose (CMC)/Polyvinyl alcohol (PVA) blend films were prepared by solution casting method. Then, these films were irradiated with γ-rays from a Co-60 source at doses over the range 0–70 kGy to investigate the modifications induced in the optical and dielectric properties. The dielectric constant (ε′) was measured in the temperature range 303–408 K and in the frequency range 10 kHz–1 MHz. The indirect optical band gap was found to increase within the dose range 0–10 kGy, and to decrease at the higher doses. The refractive index values, however, showed a reversed behavior. The highest transmittance percentage was obtained at 10 kGy dose. According to the frequency and temperature dependence of ε′, α- relaxation peaks were observed in all samples and assigned to the micro-Brownian motion of the blend chains. The values of ε′ showed a decrease in the dose range 0–10 kGy and an increase in the dose range 10–70 kGy. The ac conductivity σ ac (T) showed an Arrhenius type behavior separated into two distinct regions. The results of the present system are compared with those of similar materials

Konut Transformasyonu Bağlamında Lefke’deki CMC Evlerinin Zaman İçerisindeki Dönüşümü / The Gradual Transformation of CMC Houses in Lefke within the Context of Housing Transformation

Directory of Open Access Journals (Sweden)

Çağla Beyaz

2017-06-01

Full Text Available Abstract This study aims to determine the reflections of the factors affecting the gradual change of the houses constructed for the American mining company CMC (Cyprus Mines Corporation in Lefke between 1916 and 1974. Research has shown that such factors as life standards, needs, politics, environmental factors, climate, geography and cultural factors have changed the housing demand. Having taken all these factors into consideration, we have reached a conclusion regarding the transformation of the houses by analysing the collected data by field research techniques appropriate to CMC houses in Lefke. The field research has been conducted by taking samples from each category and analysing them; and the gradual transformation and the underlying environmental factors have been determined. The field research techniques used in the study are interviews, photos, relieves and archive research. In the result obtained from the general work; Along with the rapid development caused by the effects of the Industrial Revolution, religious, cultural, economical, political and architectural conditions have been shaped in different forms and values. Along with these circumstances, the changes and transformations that observed in the world and affecting the cities have also affected Cyprus Island. In the Lefke region, along with the establishment of the CMC, the positive and negative effects of the terraced houses, built for the first time in Cyprus in four different categories and their close surroundings, draw quite attention. In the study, the transformations of these houses until today and the factors affecting them have been also determined. Öz Çalışma, Lefke Bölgesinde 1916-1974 yılları arasında faaliyet gösteren Amerikan maden şirketi CMC (Cyprus Mines Corporation için yapılmış olan konutların zaman içerisindeki form değişimine etki eden faktörlerin, konut mekânına olan etkilerini saptamaya yöneliktir. Konut ihtiyacının, yaşam �

Disintegration of positive isometric group representations on L^p-spaces

NARCIS (Netherlands)

Jeu, de M.F.E.; Rozendaal, J.

2017-01-01

Let G be a Polish locally compact group acting on a Polish space X" role="presentation">X with a G-invariant probability measure μ" role="presentation">μ. We factorize the integral with respect to μ" role="presentation">μ in terms of the integrals with respect to the ergodic measures on X, and show

Description of symmetry of magnetic structures by representations of space groups. [Tables, projecton operator methods

Energy Technology Data Exchange (ETDEWEB)

Sikora, W

1974-10-15

A description of magnetic structures based on the use of representations of space groups is given. Representations of the space groups were established for each compound on the basis of experimental data by the method of projection operators. The compounds contained in the list are collected according to crystal systems, alphabetically within each system. The description of each compound consists of the four parts. The first part contain the chemical symbol of the compound, the second its space group. The next part contains the chemical symbol of the magnetic atom and its positions in Wychoff notation with the number of equivalent positions in the crystal unit cell. The main description of a compound magnetic structure is given in the fourth part. It contains: K vector defined in the reciprocal space, the representation according to which a magnetic structure is transformed and the axial vector function S which describes the magnetic structure.

Mathematical aspects of molecular replacement. III. Properties of space groups preferred by proteins in the Protein Data Bank.

Science.gov (United States)

Chirikjian, G; Sajjadi, S; Toptygin, D; Yan, Y

2015-03-01

The main goal of molecular replacement in macromolecular crystallography is to find the appropriate rigid-body transformations that situate identical copies of model proteins in the crystallographic unit cell. The search for such transformations can be thought of as taking place in the coset space Γ\\G where Γ is the Sohncke group of the macromolecular crystal and G is the continuous group of rigid-body motions in Euclidean space. This paper, the third in a series, is concerned with viewing nonsymmorphic Γ in a new way. These space groups, rather than symmorphic ones, are the most common ones for protein crystals. Moreover, their properties impact the structure of the space Γ\\G. In particular, nonsymmorphic space groups contain both Bieberbach subgroups and symmorphic subgroups. A number of new theorems focusing on these subgroups are proven, and it is shown that these concepts are related to the preferences that proteins have for crystallizing in different space groups, as observed in the Protein Data Bank.

Group Analysis in FieldTrip of Time-Frequency Responses: A Pipeline for Reproducibility at Every Step of Processing, Going From Individual Sensor Space Representations to an Across-Group Source Space Representation

Directory of Open Access Journals (Sweden)

Lau M. Andersen

2018-05-01

Full Text Available An important aim of an analysis pipeline for magnetoencephalographic (MEG data is that it allows for the researcher spending maximal effort on making the statistical comparisons that will answer his or her questions. The example question being answered here is whether the so-called beta rebound differs between novel and repeated stimulations. Two analyses are presented: going from individual sensor space representations to, respectively, an across-group sensor space representation and an across-group source space representation. The data analyzed are neural responses to tactile stimulations of the right index finger in a group of 20 healthy participants acquired from an Elekta Neuromag System. The processing steps covered for the first analysis are MaxFiltering the raw data, defining, preprocessing and epoching the data, cleaning the data, finding and removing independent components related to eye blinks, eye movements and heart beats, calculating participants' individual evoked responses by averaging over epoched data and subsequently removing the average response from single epochs, calculating a time-frequency representation and baselining it with non-stimulation trials and finally calculating a grand average, an across-group sensor space representation. The second analysis starts from the grand average sensor space representation and after identification of the beta rebound the neural origin is imaged using beamformer source reconstruction. This analysis covers reading in co-registered magnetic resonance images, segmenting the data, creating a volume conductor, creating a forward model, cutting out MEG data of interest in the time and frequency domains, getting Fourier transforms and estimating source activity with a beamformer model where power is expressed relative to MEG data measured during periods of non-stimulation. Finally, morphing the source estimates onto a common template and performing group-level statistics on the data are

Lie groups and symmetric spaces in memory of F. I. Karpelevich

CERN Document Server

Gindikin, S G

2003-01-01

The book contains survey and research articles devoted mainly to geometry and harmonic analysis of symmetric spaces and to corresponding aspects of group representation theory. The volume is dedicated to the memory of Russian mathematician F. I. Karpelevich (1927-2000).

A Chemically Modified Curcumin (CMC 2.24) Inhibits Nuclear Factor κB Activation and Inflammatory Bone Loss in Murine Models of LPS-Induced Experimental Periodontitis and Diabetes-Associated Natural Periodontitis.

Science.gov (United States)

Elburki, Muna S; Rossa, Carlos; Guimarães-Stabili, Morgana R; Lee, Hsi-Ming; Curylofo-Zotti, Fabiana A; Johnson, Francis; Golub, Lorne M

2017-08-01

The purpose of this study was to assess the effect of a novel chemically modified curcumin (CMC 2.24) on NF-κB and MAPK signaling and inflammatory cytokine production in two experimental models of periodontal disease in rats. Experimental model I: Periodontitis was induced by repeated injections of LPS into the gingiva (3×/week, 3 weeks); control rats received vehicle injections. CMC 2.24, or the vehicle, was administered by daily oral gavage for 4 weeks. Experimental model II: Diabetes was induced in adult male rats by streptozotocin injection; periodontal breakdown then results as a complication of uncontrolled hyperglycemia. Non-diabetic rats served as controls. CMC 2.24, or the vehicle, was administered by oral gavage daily for 3 weeks to the diabetics. Hemimaxillae and gingival tissues were harvested, and bone loss was assessed radiographically. Gingival tissues were pooled according to the experimental conditions and processed for the analysis of matrix metalloproteinases (MMPs) and bone-resorptive cytokines. Activation of p38 MAPK and NF-κB signaling pathways was assessed by western blot. Both LPS and diabetes induced an inflammatory process in the gingival tissues associated with excessive alveolar bone resorption and increased activation of p65 (NF-κB) and p38 MAPK. In both models, the administration of CMC 2.24 produced a marked reduction of inflammatory cytokines and MMPs in the gingival tissues, decreased bone loss, and decreased activation of p65 (NF-κB) and p38 MAPK. Inhibition of these cell signaling pathways by this novel tri-ketonic curcuminoid (natural curcumin is di-ketonic) may play a role in its therapeutic efficacy in locally and systemically associated periodontitis.

Validation of missed space-group symmetry in X-ray powder diffraction structures with dispersion-corrected density functional theory

DEFF Research Database (Denmark)

Hempler, Daniela; Schmidt, Martin U.; Van De Streek, Jacco

2017-01-01

More than 600 molecular crystal structures with correct, incorrect and uncertain space-group symmetry were energy-minimized with dispersion-corrected density functional theory (DFT-D, PBE-D3). For the purpose of determining the correct space-group symmetry the required tolerance on the atomic...... with missed symmetry were investigated by dispersion-corrected density functional theory. In 98.5% of the cases the correct space group is found....

"I Totally Agree with You": Gender Interactions in Educational Online Discussion Groups

Science.gov (United States)

Guiller, J.; Durndell, A.

2006-01-01

This paper discusses findings from an extensive project examining gender, language and computer-mediated communication (CMC) in the context of undergraduate psychology courses. The contributions of 197 introductory psychology students (148 females, 49 males) participating in asynchronous CMC as part of their course were collated and coded for…

Winter School on Operator Spaces, Noncommutative Probability and Quantum Groups

CERN Document Server

2017-01-01

Providing an introduction to current research topics in functional analysis and its applications to quantum physics, this book presents three lectures surveying recent progress and open problems.  A special focus is given to the role of symmetry in non-commutative probability, in the theory of quantum groups, and in quantum physics. The first lecture presents the close connection between distributional symmetries and independence properties. The second introduces many structures (graphs, C*-algebras, discrete groups) whose quantum symmetries are much richer than their classical symmetry groups, and describes the associated quantum symmetry groups. The last lecture shows how functional analytic and geometric ideas can be used to detect and to quantify entanglement in high dimensions.  The book will allow graduate students and young researchers to gain a better understanding of free probability, the theory of compact quantum groups, and applications of the theory of Banach spaces to quantum information. The l...

Oral Computer-Mediated Interaction Between L2 Learners: It’s About Time!

Directory of Open Access Journals (Sweden)

Yanguas, Íñigo

2010-10-01

Full Text Available This study explores task-based, synchronous oral computer-mediated communication (CMC among intermediate-level learners of Spanish. In particular, this paper examines (a how learners in video and audio CMC groups negotiate for meaning during task-based interaction, (b possible differences between both oral CMC modes and traditional face-to-face (FTF communication, and (c how this oral computer mediated negotiation compares to that found in the text-based CMC literature. Fifteen learner-to-learner dyads were randomly assigned to an audio group, a video group, and a FTF control group to complete a jigsaw task that was seeded with 16 unknown lexical items. Experimental groups used Skype, free online communication software, to carry out the task. The transcripts of the conversations reveal that oral CMC groups do indeed negotiate for meaning in this multimedia context when non-understanding occurs between speakers. In addition, results showed differences in the way audio and video groups carry out these negotiations, which were mainly due to the lack of visual contact in the audio group. No differences were found between video and FTF groups. Furthermore, oral CMC turn-taking patterns were shown to be very similar to FTF patterns but opposite to those found in written synchronous CMC. Oral CMC interaction patterns are shown to be more versatile.

International Space Station Earth Observations Working Group

Science.gov (United States)

Stefanov, William L.; Oikawa, Koki

2015-01-01

The multilateral Earth Observations Working Group (EOWG) was chartered in May 2012 in order to improve coordination and collaboration of Earth observing payloads, research, and applications on the International Space Station (ISS). The EOWG derives its authority from the ISS Program Science Forum, and a NASA representative serves as a permanent co-chair. A rotating co-chair position can be occupied by any of the international partners, following concurrence by the other partners; a JAXA representative is the current co-chair. Primary functions of the EOWG include, 1) the exchange of information on plans for payloads, from science and application objectives to instrument development, data collection, distribution and research; 2) recognition and facilitation of opportunities for international collaboration in order to optimize benefits from different instruments; and 3) provide a formal ISS Program interface for collection and application of remotely sensed data collected in response to natural disasters through the International Charter, Space and Major Disasters. Recent examples of EOWG activities include coordination of bilateral data sharing protocols between NASA and TsNIIMash for use of crew time and instruments in support of ATV5 reentry imaging activities; discussion of continued use and support of the Nightpod camera mount system by NASA and ESA; and review and revision of international partner contributions on Earth observations to the ISS Program Benefits to Humanity publication.

"The refer less resolve more" initiative: A five-year experience from CMC Vellore, India

Directory of Open Access Journals (Sweden)

Jachin Velavan

2012-01-01

Full Text Available India′s one billion plus strong population presents huge health care needs. Presently, approximately 250,000 general practitioners and 30,000 Government doctors are a part of the Indian healthcare workforce, but 80% of them are based in urban India. Problems which plague healthcare delivery and attributed to physician practice may be enumerated as - physicians (1 lack competencies, (2 lack updating, (3 prescribe irrationally (pressures from pharmaceutical companies and patients, (4 practice unethically, (5 refer excessively to specialists and other clinical professionals, and (6 investigate for diseases without justification. A multi-competent Family Physician who could provide a single-window, ethical, and holistic healthcare to patients and families is the need of the hour. Therefore, training, equipping, and empowering these 250,000 doctors to become such physicians will reduce health costs considerably. Distance medical education using all the andragogic methods can be used to train large number of individuals without displacing them from their work-places. Distance learning provides a useful interface for rapidly developing a specialized pool of doctors practicing and advocating family medicine as most-needed discipline. This motivated CMC Vellore, a premier institution for medical education in India, to start a the "refer less resolve more initiative" by offering "two year family medicine diploma course" by distance mode. This is an innovatively-written program consisting of problem-based self-learning modules, video-lectures, video-conferencing, and face-to-face contact programs. Ten secondary level hospitals, across the country, under the supervision of national and international family medicine faculty form the pillars of this program. This distance learning program offered by CMC Vellore has become the platform for change as there is special focus is on ethics, rational prescribing, consultation skills, application of family medicine

"The Refer Less Resolve More" Initiative: A Five-year Experience from CMC Vellore, India.

Science.gov (United States)

Velavan, Jachin

2012-01-01

India's one billion plus strong population presents huge health care needs. Presently, approximately 250,000 general practitioners and 30,000 Government doctors are a part of the Indian healthcare workforce, but 80% of them are based in urban India. Problems which plague healthcare delivery and attributed to physician practice may be enumerated as - physicians (1) lack competencies, (2) lack updating, (3) prescribe irrationally (pressures from pharmaceutical companies and patients), (4) practice unethically, (5) refer excessively to specialists and other clinical professionals, and (6) investigate for diseases without justification. A multi-competent Family Physician who could provide a single-window, ethical, and holistic healthcare to patients and families is the need of the hour. Therefore, training, equipping, and empowering these 250,000 doctors to become such physicians will reduce health costs considerably. Distance medical education using all the andragogic methods can be used to train large number of individuals without displacing them from their work-places. Distance learning provides a useful interface for rapidly developing a specialized pool of doctors practicing and advocating family medicine as most-needed discipline. This motivated CMC Vellore, a premier institution for medical education in India, to start a the "refer less resolve more initiative" by offering "two year family medicine diploma course" by distance mode. This is an innovatively-written program consisting of problem-based self-learning modules, video-lectures, video-conferencing, and face-to-face contact programs. Ten secondary level hospitals, across the country, under the supervision of national and international family medicine faculty form the pillars of this program. This distance learning program offered by CMC Vellore has become the platform for change as there is special focus is on ethics, rational prescribing, consultation skills, application of family medicine principles

Análisis psicométrico del Cuestionario de Motivos del Consumo de Alcohol (CMC en escolares de la ciudad de Bogotá

Directory of Open Access Journals (Sweden)

Leonardo Pardo Jaime

2016-07-01

Full Text Available El objetivo del presente estudio consistió en analizar las propiedades psicométricas del Cuestionario de Motivos del Consumo de Alcohol (CMC en escolares de la ciudad de Bogotá. Para ello, se contó con 206 participantes, a quienes se les aplicó el cuestionario. Los resultados fueron objeto de un análisis factorial exploratorio por medio de la extracción de componentes principales, con rotación Varimax, así como de un análisis de confiabilidad por alfa de Cronbach. Los mismos muestran 4 factores con apropiada carga factorial tanto por factor como por reactivo, explicando el 73,359% de la varianza, y un índice de confiabilidad de ,945. Así entonces, el Cuestionario de Motivos del Consumo de Alcohol (CMC presenta una estructura similar a otros estudios, lo que indica que es una escala con adecuada validez de constructo y, por lo tanto, confiable para utilizarse en escolares bogotanos. Abstract The objective of this psychometric study is to analyze the psychometric properties of the Drinking Motives Questionnaire (DMQ in school children in Bogotá city. For this, there were chosen 206 sample participants who were administered the questionnaire, applying an exploratory factor analysis by using a principal component extraction with Varimax rotation, and a Cronbach’s alpha reliability analysis was also performed. The results show four factors with an appropriate factor load, by factor and by reactive, explaining a variance of 73.359% , and a reliability index of 945. The results show that the Drinking motives Questionnaire (CMC show a similar structure in comparison with surveys made in other countries. This indicates an appropriate construct validity, and reliability for its use in school children in Bogotá city.

Characterization of LWRS Hybrid SiC-CMC-Zircaloy-4 Fuel Cladding after Gamma Irradiation

Energy Technology Data Exchange (ETDEWEB)

Isabella J van Rooyen

2012-09-01

The purpose of the gamma irradiation tests conducted at the Idaho National Laboratory (INL) was to obtain a better understanding of chemical interactions and potential changes in microstructural properties of a mock-up hybrid nuclear fuel cladding rodlet design (unfueled) in a simulated PWR water environment under irradiation conditions. The hybrid fuel rodlet design is being investigated under the Light Water Reactor Sustainability (LWRS) program for further development and testing of one of the possible advanced LWR nuclear fuel cladding designs. The gamma irradiation tests were performed in preparation for neutron irradiation tests planned for a silicon carbide (SiC) ceramic matrix composite (CMC) zircaloy-4 (Zr-4) hybrid fuel rodlet that may be tested in the INL Advanced Test Reactor (ATR) if the design is selected for further development and testing

Group quantization on configuration space: Gauge symmetries and linear fields

International Nuclear Information System (INIS)

Navarro, M.; Aldaya, V.; Calixto, M.

1997-01-01

A new, configuration-space picture of a formalism of group quantization, the GAQ formalism, is presented in the context of a previous algebraic generalization. This presentation serves to make a comprehensive discussion in which other extensions of the formalism, principally to incorporate gauge symmetries, are developed as well. Both images are combined in order to analyze, in a systematic manner and with complete generality, the case of linear fields (Abelian current groups). To illustrate these developments we particularize them for several fields and, in particular, we carry out the quantization of the Abelian Chern endash Simons models over an arbitrary closed surface in detail. copyright 1997 American Institute of Physics

An Update on Design Tools for Optimization of CMC 3D Fiber Architectures

Science.gov (United States)

Lang, J.; DiCarlo, J.

2012-01-01

Objective: Describe and up-date progress for NASA's efforts to develop 3D architectural design tools for CMC in general and for SIC/SiC composites in particular. Describe past and current sequential work efforts aimed at: Understanding key fiber and tow physical characteristics in conventional 2D and 3D woven architectures as revealed by microstructures in the literature. Developing an Excel program for down-selecting and predicting key geometric properties and resulting key fiber-controlled properties for various conventional 3D architectures. Developing a software tool for accurately visualizing all the key geometric details of conventional 3D architectures. Validating tools by visualizing and predicting the Internal geometry and key mechanical properties of a NASA SIC/SIC panel with a 3D orthogonal architecture. Applying the predictive and visualization tools toward advanced 3D orthogonal SiC/SIC composites, and combining them into a user-friendly software program.

CMC Control Surface Designs, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — As space exploration and hypersonic cruise technologies develop, the focus has shifted towards the development of lightweight, fully reusable and lower cost...

Irreducible quantum group modules with finite dimensional weight spaces

DEFF Research Database (Denmark)

Pedersen, Dennis Hasselstrøm

a finitely generated U q -module which has finite dimensional weight spaces and is a sum of those. Our approach follows the procedures used by S. Fernando and O. Mathieu to solve the corresponding problem for semisimple complex Lie algebra modules. To achieve this we have to overcome a number of obstacles...... not present in the classical case. In the process we also construct twisting functors rigerously for quantum group modules, study twisted Verma modules and show that these admit a Jantzen filtration with corresponding Jantzen sum formula....

CfDS attends the first meeting of the All-Party Parliamentary Astronomy and Space Environment Group

Science.gov (United States)

Mizon, B.

1999-06-01

This group first met on March 11th, 1999, as 'a forum for discussion to further parliamentary interest in astronomy and the space environment affecting terrestrial life and its climate; and to increase awareness of the social, political and philosophical implications of present and future space technologies connected with exploring and understanding the cosmos'. CfDS coordinator Bob Mizon attended the first meeting of the group.

The dual algebra of the Poincare group on Fock space

International Nuclear Information System (INIS)

Klink, W.H.; Iowa Univ., Iowa City, IA

1989-01-01

The Lie algebra of operators commuting with the Poincare group on the Fock space appropriate for a massive spinless particle is constructed in terms of raising and lowering operators indexed by a Lorentz invariant function. From the assumption that the phase operator is an element of this Lie algebra, it is shown that the scattering operator can be written as a unitary representation operator of the group associated with the Lie algebra. A simple choice of the phase operator shows that the Lorentz invariant function can be interpreted as a basic scattering amplitude, in the sense that all multiparticle scattering amplitudes can be written in terms of this basic scattering amplitude. (orig.)

Real space renormalization group for spectra and density of states

International Nuclear Information System (INIS)

Wiecko, C.; Roman, E.

1984-09-01

We discuss the implementation of the Real Space Renormalization Group Decimation Technique for 1-d tight-binding models with long range interactions with or without disorder and for the 2-d regular square lattice. The procedure follows the ideas developed by Southern et al. Some new explicit formulae are included. The purpose of this study is to calculate spectra and densities of states following the procedure developed in our previous work. (author)

METHOD OF GROUP OBJECTS FORMING FOR SPACE-BASED REMOTE SENSING OF THE EARTH

Directory of Open Access Journals (Sweden)

A. N. Grigoriev

2015-07-01

Full Text Available Subject of Research. Research findings of the specific application of space-based optical-electronic and radar means for the Earth remote sensing are considered. The subject matter of the study is the current planning of objects survey on the underlying surface in order to increase the effectiveness of sensing system due to the rational use of its resources. Method. New concept of a group object, stochastic swath and stochastic length of the route is introduced. The overview of models for single, group objects and their parameters is given. The criterion for the existence of the group object based on two single objects is formulated. The method for group objects formation while current survey planning has been developed and its description is presented. The method comprises several processing stages for data about objects with the calculation of new parameters, the stochastic characteristics of space means and validates the spatial size of the object value of the stochastic swath and stochastic length of the route. The strict mathematical description of techniques for model creation of a group object based on data about a single object and onboard special complex facilities in difficult conditions of registration of spatial data is given. Main Results. The developed method is implemented on the basis of modern geographic information system in the form of a software tool layout with advanced tools of processing and analysis of spatial data in vector format. Experimental studies of the forming method for the group of objects were carried out on a different real object environment using the parameters of modern national systems of the Earth remote sensing detailed observation Canopus-B and Resurs-P. Practical Relevance. The proposed models and method are focused on practical implementation using vector spatial data models and modern geoinformation technologies. Practical value lies in the reduction in the amount of consumable resources by means of

El Naschie's Cantorian space-time and general relativity by means of Barbilian's group. A Cantorian fractal axiomatic model of space-time

International Nuclear Information System (INIS)

Gottlieb, I.; Agop, M.; Jarcau, M.

2004-01-01

One builds the vacuum metrics of the stationary electromagnetic field through the complex potential model. There are thus emphasized both a variational principle, independent on the Ricci tensor, and some internal symmetries of the vacuum solutions. One shows that similar results may be obtained using the Barbiliant's group. By analytical continuation of a Barbilian transformation the link between the fixed points of the modular groups of the vacuum and the golden mean PHI=(1/(1+PHI))=(√5-1)/2 of ε (∞) space-time is established. Finally, a Cantorian fractal axiomatic model of the space-time is presented. The model is explained using a set of coupled equations which may describe the self organizing processes at the solid-liquid, plasma-plasma, and superconductor-superconductor interfaces

Computer Mediated Communication for Social and Academic Purposes: Profiles of Use and University Students' Gratifications

Science.gov (United States)

Vrocharidou, Anatoli; Efthymiou, Ilias

2012-01-01

The present study approaches the Internet as a social space, where university students make use of computer mediated communication (CMC) applications, i.e. e-mail, instant messaging and social network sites, in order to satisfy social and academic needs. We focus on university students, because they represent one of the most avid groups of CMC…

Utilización de lactosuero de queso fresco en la elaboración de una bebida fermentada con adición de pulpa maracuyá (passiflora edulis variedad púrpura y carbóximetil celulosa (cmc, enriquecida con vitaminas A y D.

Directory of Open Access Journals (Sweden)

Sepúlveda Valencia José Uriel

2002-12-01

Full Text Available Se puede obtener una bebida con características especiales a partir de la fermentación de suero de queso fresco, en presencia de Streptococcus thermophillus y Lactobacillus bulgaricus, comparable con un yogur tradicional. Se utilizaron 150 kg de lactosuero de queso fresco, a cada muestra de 50 kg se le aplicó un tratamiento con estabilizantes comerciales cuya base es carboximetilcelulosa (CMC 27 FG, CMC 28FG y CMC 29FG, cuya función es conferir viscosidad. La bebida que se desarrolló a partir del gel formado durante el proces, se saborizó con pulpa de maracuyá (Pasiflora edulis var. púrpura, y se enriqueció con vitaminas A y D. La bebida con el tratamiento CMC 28FG demostró las mejores características sensoriales, el producto se mantuvo homogéneo por 24 días de almacenamiento a una temperatura de 6°C, durante este tiempo no se presentaron fenómenos de histéresis, gomosidad o grumosidad al tacto, sin embargo se observó un aumento en la acidez y una disminución de la viscosidad en el tiempo, ambos aspectos no fueron ampliamente percibidos por los jueces hasta la cuarta semana.

Grouped fuzzy SVM with EM-based partition of sample space for clustered microcalcification detection.

Science.gov (United States)

Wang, Huiya; Feng, Jun; Wang, Hongyu

2017-07-20

Detection of clustered microcalcification (MC) from mammograms plays essential roles in computer-aided diagnosis for early stage breast cancer. To tackle problems associated with the diversity of data structures of MC lesions and the variability of normal breast tissues, multi-pattern sample space learning is required. In this paper, a novel grouped fuzzy Support Vector Machine (SVM) algorithm with sample space partition based on Expectation-Maximization (EM) (called G-FSVM) is proposed for clustered MC detection. The diversified pattern of training data is partitioned into several groups based on EM algorithm. Then a series of fuzzy SVM are integrated for classification with each group of samples from the MC lesions and normal breast tissues. From DDSM database, a total of 1,064 suspicious regions are selected from 239 mammography, and the measurement of Accuracy, True Positive Rate (TPR), False Positive Rate (FPR) and EVL = TPR* 1-FPR are 0.82, 0.78, 0.14 and 0.72, respectively. The proposed method incorporates the merits of fuzzy SVM and multi-pattern sample space learning, decomposing the MC detection problem into serial simple two-class classification. Experimental results from synthetic data and DDSM database demonstrate that our integrated classification framework reduces the false positive rate significantly while maintaining the true positive rate.

The bicovariant differential calculus on the κ-Poincare group and on the κ-Minkowski space

International Nuclear Information System (INIS)

Kosinski, P.; Maslanka, P.; Sobczyk, J.

1996-01-01

The bicovariant differential calculus on the four-dimensional κ-Poincare group and the corresponding Lie-algebra-like structure are described. The differential calculus on the n-dimensional κ-Minkowski space covariant under the action of the κ-Poincare group was constructed. 5 refs

Extended system of space-time coordinates and generalized translation group of transformations

International Nuclear Information System (INIS)

Yamaleev, R.M.

1980-01-01

A method of extending space-time is considered. In the nonrelativistic case extending goes by joining a scalar to the 3-dimensional radius-vector, completing this to a quaternion. The interpretation of scalar obtained as a parameter of scale transfornation of the generalized translation of group of transformations is given. Some basic expressions of nonrelativistic classical mechanics in the quaternion representation are given. In the relativistic case space-time is constructed from two quaternions: the first one consists of a pair scalar-3-dimensional radius-vector; the second one, of a pair-time-scalar-3-dimensional time-vector. Time and space coordinates, enter into the expression with the opposite signature. The introduction of a time-vector as well as of a new scalar is stipulated by the requirement of the principle of conforming quantum mechanics of the 1/2 spin to classical mechanics [ru

Canonical Groups for Quantization on the Two-Dimensional Sphere and One-Dimensional Complex Projective Space

International Nuclear Information System (INIS)

Sumadi A H A; H, Zainuddin

2014-01-01

Using Isham's group-theoretic quantization scheme, we construct the canonical groups of the systems on the two-dimensional sphere and one-dimensional complex projective space, which are homeomorphic. In the first case, we take SO(3) as the natural canonical Lie group of rotations of the two-sphere and find all the possible Hamiltonian vector fields, and followed by verifying the commutator and Poisson bracket algebra correspondences with the Lie algebra of the group. In the second case, the same technique is resumed to define the Lie group, in this case SU (2), of CP'.We show that one can simply use a coordinate transformation from S 2 to CP 1 to obtain all the Hamiltonian vector fields of CP 1 . We explicitly show that the Lie algebra structures of both canonical groups are locally homomorphic. On the other hand, globally their corresponding canonical groups are acting on different geometries, the latter of which is almost complex. Thus the canonical group for CP 1 is the double-covering group of SO(3), namely SU(2). The relevance of the proposed formalism is to understand the idea of CP 1 as a space of where the qubit lives which is known as a Bloch sphere

Space Weather Activities of IONOLAB Group: IONOLAB-TEC

Science.gov (United States)

Arikan, F.; Sezen, U.; Arikan, O.; Ugurlu, O.; Nayir, H.

2009-04-01

Space Weather (SW) is the concept of changing environmental conditions in outer space and affect Earth and its technological systems. SW is a consequence of the solar activities and the coupling of solar energy on Earth's atmosphere due to the Earth's magnetic field. The monitoring and prediction of SW has utmost importance for HF communication, Satellite communication, navigation and guidance systems, Low Earth Orbit (LEO) satellite systems, Space Craft exit and entry into the atmosphere. Ionosphere is the plasma layer of the atmosphere that is ionized by solar radiation and it is a key player of SW. Ionosphere is a temporally and spatially varying, dispersive, anisotropic and inhomogeneous medium that is characterized primarily by its electron density distribution. IONOLAB is a group of researchers of various disciplines, getting together to handle challenges of the Earth's ionosphere. The team has researchers from Hacettepe University and Bilkent University, Department of Electrical and Electronics Engineering and General Command of Mapping of Turkish Army. One of the most important contributions of IONOLAB group is the automated web-based computation service for Total Electron Content (TEC). TEC corresponds to the line integral of electron density distribution on a given path. TEC can also be expressed as the amount of free electrons within 1 m2 cross-sectional area of the cylinder on the ray path. Global Position System (GPS) provides a cost-effective medium for monitoring of ionosphere using the signals recorded by stationary GPS receivers in estimating TEC. IONOLAB group has developed IONOLAB-TEC for reliable and robust estimates for all latitudes and both calm and disturbed days by using RINEX, IONEX and satellite ephemeris data provided from the IGS centers. IONOLAB-TEC consists of a regularized signal estimation algorithm which combines signals from all GPS satellites for a given instant and a given receiver, for a desired time period or for 24 hours

Realization of vector fields for quantum groups as pseudodifferential operators on quantum spaces

International Nuclear Information System (INIS)

Chu, Chong-Sun; Zumino, B.

1995-01-01

The vector fields of the quantum Lie algebra are described for the quantum groups GL q (n), SL q (N) and SO q (N) as pseudodifferential operators on the linear quantum spaces covariant under the corresponding quantum group. Their expressions are simple and compact. It is pointed out that these vector fields satisfy certain characteristic polynomial identities. The real forms SU q (N) and SO q (N,R) are discussed in detail

Assessment of space plasma effectsfor satellite applications:Working Group 2 overview

Directory of Open Access Journals (Sweden)

N. Jakowski

2004-06-01

Full Text Available An important part of the tasks of Working Group 2 of the COST Action 271 «Assessment of space plasma effect for satellites applications» is the assessment of novel data sources for information about the state of ionisation of the ionosphere. This report deals with those aspects which are not represented adequately in the scientific papers in this issue. Here emphasis is given to the product aspect (data and model collections, descriptions of methods and algorithms, availability of products, expected future developments and the links between the past COST Actions 238 and 251 with the present Action 271 and with possible future cooperations. Working Group 2 was leading in the transionospheric propagation aspects of possible products for the International Telecommunication Union?s Radiocommunication (ITU-R Study Group 3. This report gives a short overview emphasizing future developments.

Fourier-space TEM reconstructions with symmetry adapted functions for all rotational point groups.

Science.gov (United States)

Trapani, Stefano; Navaza, Jorge

2013-05-01

A general-purpose and simple expression for the coefficients of symmetry adapted functions referred to conveniently oriented symmetry axes is given for all rotational point groups. The expression involves the computation of reduced Wigner-matrix elements corresponding to an angle specific to each group and has the computational advantage of leading to Fourier-space TEM (transmission electron microscopy) reconstruction procedures involving only real valued unknowns. Using this expression, a protocol for ab initio view and center assignment and reconstruction so far used for icosahedral particles has been tested with experimental data in other point groups. Copyright © 2013 Elsevier Inc. All rights reserved.

The Community-based Organizations Working Group of the Space Science Education Support Network

Science.gov (United States)

Lutz, J. H.; Lowes, L. L.; Asplund, S.

2004-12-01

The NASA Space Science Support Network Community-based Organizations Working Group (CBOWG) has been working for the past two years on issues surrounding afterschool programs and programs for youth (e.g., Girl Scouts, Boy Scouts, Boys and Girls Clubs, 4-H, summer camps, afterschool and weekend programs for various ages, programs with emphases on minority youth). In this session the co-leaders of the CBOWG will discuss the challenges of working with community-based organizations on a regional or national level. We will highlight some ties that we have forged with the National Institute for Out of School Time (NIOST) and the National Afterschool Association (NAA). We will also talk about efforts to coordinate how various entities within NASA cooperate with community-based organizations to serve the best interests of these groups. We will give a couple of examples of how NASA space science organizations have partnered with community-based organizations. The session will include some handouts of information and resources that the CBOWG has found useful in developing an understanding of this segment of informal education groups. We would like to thank NASA for providing resources to support the work of the CBOWG.

[Computer mediated discussion and attitude polarization].

Science.gov (United States)

Shiraishi, Takashi; Endo, Kimihisa; Yoshida, Fujio

2002-10-01

This study examined the hypothesis that computer mediated discussions lead to more extreme decisions than face-to-face (FTF) meeting. Kiesler, Siegel, & McGuire (1984) claimed that computer mediated communication (CMC) tended to be relatively uninhibited, as seen in 'flaming', and that group decisions under CMC using Choice Dilemma Questionnaire tended to be more extreme and riskier than FTF meetings. However, for the same reason, CMC discussions on controversial social issues for which participants initially hold strongly opposing views, might be less likely to reach a consensus, and no polarization should occur. Fifteen 4-member groups discussed a controversial social issue under one of three conditions: FTF, CMC, and partition. After discussion, participants rated their position as a group on a 9-point bipolar scale ranging from strong disagreement to strong agreement. A stronger polarization effect was observed for FTF groups than those where members were separated with partitions. However, no extreme shift from their original, individual positions was found for CMC participants. There results were discussed in terms of 'expertise and status equalization' and 'absence of social context cues' under CMC.

Fabrication of CMC-g-PAM superporous polymer monoliths via eco-friendly Pickering-MIPEs for superior adsorption of methyl violet and methylene blue

Science.gov (United States)

Wang, Feng; Zhu, Yongfeng; Wang, Wenbo; Zong, Li; Lu, Taotao; Wang, Aiqin

2017-06-01

A series of superporous carboxymethylcellulose-graft-poly(acrylamide) (CMC-g-PAM) polymer monoliths presenting interconnected pore structure and excellent adsorption properties were prepared by one-step free-radical grafting polymerization reaction of CMC and acrylamide (AM) in the oil-in-water (O/W) Pickering-medium internal phase emulsions (Pickering-MIPEs) composed of non-toxic edible oil as a dispersion phase and natural Pal nanorods as stabilizers. The effects of Pal dosage, AM dosage, and co-surfactant Tween-20 (T-20) on the pore structures of the monoliths were studied. It was revealed that the well-defined pores were formed when the dosages of Pal and T-20 are 9-14% and 3%, respectively. The porous monolith can rapidly adsorb 1585 mg/g of methyl violet (MV) and 1625 mg/g of methylene blue (MB). After the monolith was regenerated by adsorption-desorption process for 5 times, the adsorption capacities still reached 92.1% (for MV) and 93.5% (for MB) of the initial maximum adsorption capacities. The adsorption process was fitted with Langmuir adsorption isotherm model and pseudo-second-order adsorption kinetic model very well, which indicate that mono-layer chemical adsorption mainly contribute to the high-capacity adsorption for dyes. The superporous polymer monolith prepared from eco-friendly Pickering-MIPEs shows good adsorption capacity and fast adsorption rate, which is potential adsorbent for the decontimination of dye-containing wastewater.

Comparison of the Cc and R3c space groups for the superlattice phase of Pb(Zr0.52Ti0.48)O3

International Nuclear Information System (INIS)

Ranjan, Rajeev; Singh, Akhilesh Kumar; Ragini; Pandey, Dhananjai

2005-01-01

Recent controversy about the space group of the low temperature superlattice phase of Pb(Zr 0.52 Ti 0.48 )O 3 is settled. It is shown that the R3c space group for the superlattice phase cannot correctly account for the peak positions of the superlattice reflections present in the neutron diffraction patterns. The correct space group is reconfirmed to be Cc. A comparison of the atomic coordinates of Cc and Cm space groups is also presented to show that in the absence of superlattice reflections, as is the case with x-ray diffraction data, one would land up in the Cm space group. This superlattice phase is found to coexist with another monoclinic phase of the Cm space group

A multicentre, randomised, controlled trial to assess the safety, ease of use, and reliability of hyaluronic acid/carboxymethylcellulose powder adhesion barrier versus no barrier in colorectal laparoscopic surgery.

Science.gov (United States)

Berdah, Stéphane V; Mariette, Christophe; Denet, Christine; Panis, Yves; Laurent, Christophe; Cotte, Eddy; Huten, Nöel; Le Peillet Feuillet, Eliane; Duron, Jean-Jacques

2014-10-27

Intra-peritoneal adhesions are frequent following abdominal surgery and are the most common cause of small bowel obstructions. A hyaluronic acid/carboxymethylcellulose (HA/CMC) film adhesion barrier has been shown to reduce adhesion formation in abdominal surgery. An HA/CMC powder formulation was developed for application during laparoscopic procedures. This was an exploratory, prospective, randomised, single-blind, parallel-group, Phase IIIb, multicentre study conducted at 15 hospitals in France to assess the safety of HA/CMC powder versus no adhesion barrier following laparoscopic colorectal surgery. Subjects ≥18 years of age who were scheduled for colorectal laparoscopy (Mangram contamination class I‒III) within 8 weeks of selection were eligible, regardless of aetiology. Participants were randomised 1:1 to the HA/CMC powder or no adhesion barrier group using a centralised randomisation list. Patients assigned to HA/CMC powder received a single application of 1 to 10 g on adhesion-prone areas. In the no adhesion barrier group, no adhesion barrier or placebo was applied. The primary safety assessments were the incidence of adverse events, serious adverse events, and surgical site infections (SSIs) for 30 days following surgery. Between-group comparisons were made using Fisher's exact test. Of those randomised to the HA/CMC powder (n = 105) or no adhesion barrier (n = 104) groups, one patient in each group discontinued prior to the study end (one death in each group). Adverse events were more frequent in the HA/CMC powder group versus the no adhesion barrier group (63% vs. 39%; P barrier group in SSIs (21% vs. 14%; P = 0.216) and serious SSIs (12% vs. 9%; P = 0.38), or in the most frequent serious SSIs of pelvic abscess (5% and 2%; significance not tested), anastomotic fistula (3% and 4%), and peritonitis (2% and 3%). This exploratory study found significantly higher rates of adverse events and serious adverse events in the HA/CMC powder group compared with

Group-velocity dispersion effects on quantum noise of a fiber optical soliton in phase space

International Nuclear Information System (INIS)

Ju, Heongkyu; Lee, Euncheol

2010-01-01

Group-velocity dispersion (GVD) effects on quantum noise of ultrashort pulsed light are theoretically investigated at the soliton energy level, using Gaussian-weighted pseudo-random distribution of phasors in phase space for the modeling of quantum noise properties including phase noise, photon number noise, and quantum noise shape in phase space. We present the effects of GVD that mixes the different spectral components in time, on the self-phase modulation(SPM)-induced quantum noise properties in phase space such as quadrature squeezing, photon-number noise, and tilting/distortion of quantum noise shape in phase space, for the soliton that propagates a distance of the nonlinear length η NL = 1/( γP 0 ) (P 0 is the pulse peak power and γ is the SPM parameter). The propagation dependence of phase space quantum noise properties for an optical soliton is also provided.

Implementation of small group discussion as a teaching method in earth and space science subject

Science.gov (United States)

Aryani, N. P.; Supriyadi

2018-03-01

In Physics Department Universitas Negeri Semarang, Earth and Space Science subject is included in the curriculum of the third year of physics education students. There are various models of teaching earth and space science subject such as textbook method, lecturer, demonstrations, study tours, problem-solving method, etc. Lectures method is the most commonly used of teaching earth and space science subject. The disadvantage of this method is the lack of two ways interaction between lecturers and students. This research used small group discussion as a teaching method in Earth and Space science. The purpose of this study is to identify the conditions under which an efficient discussion may be initiated and maintained while students are investigating properties of earth and space science subjects. The results of this research show that there is an increase in student’s understanding of earth and space science subject proven through the evaluation results. In addition, during the learning process, student’s activeness also increase.

Positive-definite functions and unitary representations of locally compact groups in a Hilbert space

International Nuclear Information System (INIS)

Gali, I.M.; Okb el-Bab, A.S.; Hassan, H.M.

1977-08-01

It is proved that the necessary and sufficient condition for the existence of an integral representation of a group of unitary operators in a Hilbert space is that it is positive-definite and continuous in some topology

Selenomethionine substitution of orotidine-5-monophosphate decarboxylase causes a change in crystal contacts and space group

DEFF Research Database (Denmark)

Poulsen, Jens-Christian Navarro; Harris, Pernille; Jensen, Kaj Frank

2001-01-01

with the inhibitor 1-(5'-phospho- -D-ribofuranosyl)barbituric acid crystallizes under similar conditions as the native enzyme. In contrast to the native enzyme, where the crystals belong to the orthorhombic space group P212121, the SeMet-substituted enzyme crystallizes in the monoclinic space group P21......-wavelength anomalous dispersion technique, both native and SeMet-substituted proteins have been produced and purified. During the production of SeMet ODCase, it was observed that SeMet was the only amino acid that it was necessary to add to the defined medium during expression. SeMet-substituted ODCase in complex...

Loop space representation of quantum general relativity and the group of loops

International Nuclear Information System (INIS)

Gambini, R.

1991-01-01

The action of the constraints of quantum general relativity on a general state in the loop representation is coded in terms of loop derivatives. These differential operators are related to the infinitesimal generators of the group of loops and generalize the area derivative first considered by Mandelstam. A new sector of solutions of the physical states space of nonperturbative quantum general relativity is found. (orig.)

X-ray crystallography facility for the international space station

International Nuclear Information System (INIS)

McdDonald, William T.; Lewis, Johanna L.; Smith, Craig D.; DeLucas, Lawrence J.

1997-01-01

Directed by NASA's Office of Space Access and Technology (OSAT), the University of Alabama at Birmingham (UAB) Center for Macromolecular Crystallography (CMC) recently completed a Design Feasibility Study for the X-ray Crystallography Facility (XCF) for the International Space Station (ISS). The XCF is a facility for growing macromolecular protein crystals; harvesting, selecting, and mounting sample crystals, and snap-freezing the samples, if necessary; performing x-ray diffraction; and downlinking the diffraction data to the ground. Knowledge of the structure of protein molecules is essential for the development of pharmaceuticals by structure-based drug design techniques. Currently, x-ray diffraction of high quality protein crystals is the only method of determining the structure of these macromolecules. High quality protein crystals have been grown in microgravity onboard the Space Shuttle Orbiter for more than 10 years, but these crystals always have been returned to Earth for x-ray diffraction. The XCF will allow crystal growth, harvesting, mounting, and x-ray diffraction onboard the ISS, maximizing diffraction data quality and timeliness. This paper presents the XCF design concept, describing key feasibility issues for the ISS application and advanced technologies and operational features which resolve those issues. The conclusion is that the XCF design is feasible and can be operational onboard the ISS by early in 2002

Generalized 2-vector spaces and general linear 2-groups

OpenAIRE

Elgueta, Josep

2008-01-01

In this paper a notion of {\\it generalized 2-vector space} is introduced which includes Kapranov and Voevodsky 2-vector spaces. Various kinds of generalized 2-vector spaces are considered and examples are given. The existence of non free generalized 2-vector spaces and of generalized 2-vector spaces which are non Karoubian (hence, non abelian) categories is discussed, and it is shown how any generalized 2-vector space can be identified with a full subcategory of an (abelian) functor category ...

Distributed Model Predictive Control over Multiple Groups of Vehicles in Highway Intelligent Space for Large Scale System

Directory of Open Access Journals (Sweden)

Tang Xiaofeng

2014-01-01

Full Text Available The paper presents the three time warning distances for solving the large scale system of multiple groups of vehicles safety driving characteristics towards highway tunnel environment based on distributed model prediction control approach. Generally speaking, the system includes two parts. First, multiple vehicles are divided into multiple groups. Meanwhile, the distributed model predictive control approach is proposed to calculate the information framework of each group. Each group of optimization performance considers the local optimization and the neighboring subgroup of optimization characteristics, which could ensure the global optimization performance. Second, the three time warning distances are studied based on the basic principles used for highway intelligent space (HIS and the information framework concept is proposed according to the multiple groups of vehicles. The math model is built to avoid the chain avoidance of vehicles. The results demonstrate that the proposed highway intelligent space method could effectively ensure driving safety of multiple groups of vehicles under the environment of fog, rain, or snow.

Planning and managing future space facility projects. [management by objectives and group dynamics

Science.gov (United States)

Sieber, J. E.; Wilhelm, J. A.; Tanner, T. A.; Helmreich, R. L.; Burgenbauch, S. F.

1979-01-01

To learn how ground-based personnel of a space project plan and organize their work and how such planning and organizing relate to work outcomes, longitudinal study of the management and execution of the Space Lab Mission Development Test 3 (SMD 3) was performed at NASA Ames Research Center. A view of the problems likely to arise in organizations and some methods of coping with these problems are presented as well as the conclusions and recommendations that pertain strictly to SMD 3 management. Emphasis is placed on the broader context of future space facility projects and additional problems that may be anticipated. A model of management that may be used to facilitate problem solving and communication - management by objectives (MBO) is presented. Some problems of communication and emotion management that MBO does not address directly are considered. Models for promoting mature, constructive and satisfying emotional relationships among group members are discussed.

Assessment of NDE methods for detecting cracks and damage in environmental barrier coated CMC tested under tension

Science.gov (United States)

Abdul-Aziz, Ali; Wroblewski, Adam C.; Bhatt, Ramakrishna T.; Jaskowiak, Martha H.; Gorican, Daniel; Rauser, Richard W.

2015-03-01

For validating physics based analytical models predicting spallation life of environmental barrier coating (EBC) on fiber reinforced ceramic matrix composites, the fracture strength of EBC and kinetics of crack growth in EBC layers need to be experimentally determined under engine operating conditions. In this study, a multi layered barium strontium aluminum silicate (BSAS) based EBC-coated, melt infiltrated silicon carbide fiber reinforced silicon carbide matrix composite (MI SiC/SiC) specimen was tensile tested at room temperature. Multiple tests were performed on a single specimen with increasing predetermined stress levels until final failure. During loading, the damage occurring in the EBC was monitored by digital image correlation (DIC). After unloading from the predetermined stress levels, the specimen was examined by optical microscopy and computed tomography (CT). Results indicate both optical microscopy and CT could not resolve the primary or secondary cracks developed during tensile loading until failure. On the other hand, DIC did show formation of a primary crack at ~ 50% of the ultimate tensile strength and this crack grew with increasing stress and eventually led to final failure of the specimen. Although some secondary cracks were seen in the DIC strain plots prior to final failure, the existence of these cracks were not confirmed by other methods. By using a higher resolution camera, it is possible to improve the capability of DIC in resolving secondary cracks and damage in coated specimen tested at room temperature, but use of DIC at high temperature requires significant development. Based on the current data, it appears that both optical microscopy and CT do not offer any hope for detecting crack initiation or determining crack growth in EBC coated CMC tested at room or high temperatures after the specimen has been unloaded. Other methods such as, thermography and optical/SEM of the polished cross section of EBC coated CMC specimens stressed to

Group Analysis in MNE-Python of Evoked Responses from a Tactile Stimulation Paradigm: A Pipeline for Reproducibility at Every Step of Processing, Going from Individual Sensor Space Representations to an across-Group Source Space Representation.

Science.gov (United States)

Andersen, Lau M

2018-01-01

An important aim of an analysis pipeline for magnetoencephalographic data is that it allows for the researcher spending maximal effort on making the statistical comparisons that will answer the questions of the researcher, while in turn spending minimal effort on the intricacies and machinery of the pipeline. I here present a set of functions and scripts that allow for setting up a clear, reproducible structure for separating raw and processed data into folders and files such that minimal effort can be spend on: (1) double-checking that the right input goes into the right functions; (2) making sure that output and intermediate steps can be accessed meaningfully; (3) applying operations efficiently across groups of subjects; (4) re-processing data if changes to any intermediate step are desirable. Applying the scripts requires only general knowledge about the Python language. The data analyses are neural responses to tactile stimulations of the right index finger in a group of 20 healthy participants acquired from an Elekta Neuromag System. Two analyses are presented: going from individual sensor space representations to, respectively, an across-group sensor space representation and an across-group source space representation. The processing steps covered for the first analysis are filtering the raw data, finding events of interest in the data, epoching data, finding and removing independent components related to eye blinks and heart beats, calculating participants' individual evoked responses by averaging over epoched data and calculating a grand average sensor space representation over participants. The second analysis starts from the participants' individual evoked responses and covers: estimating noise covariance, creating a forward model, creating an inverse operator, estimating distributed source activity on the cortical surface using a minimum norm procedure, morphing those estimates onto a common cortical template and calculating the patterns of activity

Group Analysis in MNE-Python of Evoked Responses from a Tactile Stimulation Paradigm: A Pipeline for Reproducibility at Every Step of Processing, Going from Individual Sensor Space Representations to an across-Group Source Space Representation

Directory of Open Access Journals (Sweden)

Lau M. Andersen

2018-01-01

Full Text Available An important aim of an analysis pipeline for magnetoencephalographic data is that it allows for the researcher spending maximal effort on making the statistical comparisons that will answer the questions of the researcher, while in turn spending minimal effort on the intricacies and machinery of the pipeline. I here present a set of functions and scripts that allow for setting up a clear, reproducible structure for separating raw and processed data into folders and files such that minimal effort can be spend on: (1 double-checking that the right input goes into the right functions; (2 making sure that output and intermediate steps can be accessed meaningfully; (3 applying operations efficiently across groups of subjects; (4 re-processing data if changes to any intermediate step are desirable. Applying the scripts requires only general knowledge about the Python language. The data analyses are neural responses to tactile stimulations of the right index finger in a group of 20 healthy participants acquired from an Elekta Neuromag System. Two analyses are presented: going from individual sensor space representations to, respectively, an across-group sensor space representation and an across-group source space representation. The processing steps covered for the first analysis are filtering the raw data, finding events of interest in the data, epoching data, finding and removing independent components related to eye blinks and heart beats, calculating participants' individual evoked responses by averaging over epoched data and calculating a grand average sensor space representation over participants. The second analysis starts from the participants' individual evoked responses and covers: estimating noise covariance, creating a forward model, creating an inverse operator, estimating distributed source activity on the cortical surface using a minimum norm procedure, morphing those estimates onto a common cortical template and calculating the patterns

Development of a material property database on selected ceramic matrix composite materials

Science.gov (United States)

Mahanta, Kamala

1996-01-01

Ceramic Matrix Composites, with fiber/whisker/particulate reinforcement, possess the attractive properties of ceramics such as high melting temperature, high strength and stiffness at high temperature, low density, excellent environmental resistance, combined with improved toughness and mechanical reliability. These unique properties have made these composites an enabling technology for thermomechanically demanding applications in high temperature, high stress and aggressive environments. On a broader scale, CMC's are anticipated to be applicable in aircraft propulsion, space propulsion, power and structures, in addition to ground based applications. However, it is also true that for any serious commitment of the material toward any of the intended critical thermo-mechanical applications to materialize, vigorous research has to be conducted for a thorough understanding of the mechanical and thermal behavior of CMC's. The high technology of CMC'S is far from being mature. In view of this growing need for CMC data, researchers all over the world have found themselves drawn into the characterization of CMC's such as C/SiC, SiC/SiC, SiC/Al203, SiC/Glass, SiC/C, SiC/Blackglas. A significant amount of data has been generated by the industries, national laboratories and educational institutions in the United States of America. NASA/Marshall Space Flight Center intends to collect the 'pedigreed' CMC data and store those in a CMC database within MAPTIS (Materials and Processes Technical Information System). The task of compilation of the CMC database is a monumental one and requires efforts in various directions. The project started in the form of a summer faculty fellowship in 1994 and has spilled into the months that followed and into the summer faculty fellowship of 1995 and has the prospect of continuing into the future for a healthy growth, which of course depends to a large extent on how fast CMC data are generated. The 10-week long summer fellowship has concentrated

Representation theory of 2-groups on finite dimensional 2-vector spaces

OpenAIRE

Elgueta, Josep

2004-01-01

In this paper, the 2-category $\\mathfrak{Rep}_{{\\bf 2Mat}_{\\mathbb{C}}}(\\mathbb{G})$ of (weak) representations of an arbitrary (weak) 2-group $\\mathbb{G}$ on (some version of) Kapranov and Voevodsky's 2-category of (complex) 2-vector spaces is studied. In particular, the set of equivalence classes of representations is computed in terms of the invariants $\\pi_0(\\mathbb{G})$, $\\pi_1(\\mathbb{G})$ and $[\\alpha]\\in H^3(\\pi_0(\\mathbb{G}),\\pi_1(\\mathbb{G}))$ classifying $\\mathbb{G}$. Also the categ...

Fabrication of CMC-g-PAM Superporous Polymer Monoliths via Eco-Friendly Pickering-MIPEs for Superior Adsorption of Methyl Violet and Methylene Blue.

Science.gov (United States)

Wang, Feng; Zhu, Yongfeng; Wang, Wenbo; Zong, Li; Lu, Taotao; Wang, Aiqin

2017-01-01

A series of superporous carboxymethylcellulose- graft -poly(acrylamide)/palygorskite (CMC- g -PAM/Pal) polymer monoliths presenting interconnected pore structure and excellent adsorption properties were prepared by one-step free-radical grafting polymerization reaction of CMC and acrylamide (AM) in the oil-in-water (O/W) Pickering-medium internal phase emulsions (Pickering-MIPEs) composed of non-toxic edible oil as a dispersion phase and natural Pal nanorods as stabilizers. The effects of Pal dosage, AM dosage, and co-surfactant Tween-20 (T-20) on the pore structures of the monoliths were studied. It was revealed that the well-defined pores were formed when the dosages of Pal and T-20 are 9-14 and 3%, respectively. The porous monolith can rapidly adsorb 1,585 mg/g of methyl violet (MV) and 1,625 mg/g of methylene blue (MB). After the monolith was regenerated by adsorption-desorption process for five times, the adsorption capacities still reached 92.1% (for MV) and 93.5% (for MB) of the initial maximum adsorption capacities. The adsorption process was fitted with Langmuir adsorption isotherm model and pseudo-second-order adsorption kinetic model very well, which indicate that mono-layer chemical adsorption mainly contribute to the high-capacity adsorption for dyes. The superporous polymer monolith prepared from eco-friendly Pickering-MIPEs shows good adsorption capacity and fast adsorption rate, which is potential adsorbent for the decontamination of dye-containing wastewater.

Fabrication of CMC-g-PAM Superporous Polymer Monoliths via Eco-Friendly Pickering-MIPEs for Superior Adsorption of Methyl Violet and Methylene Blue

Directory of Open Access Journals (Sweden)

Feng Wang

2017-06-01

Full Text Available A series of superporous carboxymethylcellulose-graft-poly(acrylamide/palygorskite (CMC-g-PAM/Pal polymer monoliths presenting interconnected pore structure and excellent adsorption properties were prepared by one-step free-radical grafting polymerization reaction of CMC and acrylamide (AM in the oil-in-water (O/W Pickering-medium internal phase emulsions (Pickering-MIPEs composed of non-toxic edible oil as a dispersion phase and natural Pal nanorods as stabilizers. The effects of Pal dosage, AM dosage, and co-surfactant Tween-20 (T-20 on the pore structures of the monoliths were studied. It was revealed that the well-defined pores were formed when the dosages of Pal and T-20 are 9–14 and 3%, respectively. The porous monolith can rapidly adsorb 1,585 mg/g of methyl violet (MV and 1,625 mg/g of methylene blue (MB. After the monolith was regenerated by adsorption-desorption process for five times, the adsorption capacities still reached 92.1% (for MV and 93.5% (for MB of the initial maximum adsorption capacities. The adsorption process was fitted with Langmuir adsorption isotherm model and pseudo-second-order adsorption kinetic model very well, which indicate that mono-layer chemical adsorption mainly contribute to the high-capacity adsorption for dyes. The superporous polymer monolith prepared from eco-friendly Pickering-MIPEs shows good adsorption capacity and fast adsorption rate, which is potential adsorbent for the decontamination of dye-containing wastewater.

Independence of automorphism group, center, and state space of quantum logics

International Nuclear Information System (INIS)

Navara, M.

1992-01-01

We prove that quantum logics (-orthomodular posets) admit full independence of the attributes important within the foundations of quantum mechanics. Namely, we present the construction of quantum logics with given sublogics (=physical subsystems), automorphism groups, centers (=open-quotes classical partsclose quotes of the systems), and state spaces. Thus, all these open-quotes parametersclose quotes are independent. Our result is rooted in the line of investigation carried out by Greechie; Kallus and Trnkova; Kalmbach; and Navara and Ptak; and considerably enriches the known algebraic methods in orthomodular posets. 19 refs., 1 fig

Does the Health Impact of Exposure to Neighbourhood Green Space Differ between Population Groups? An Explorative Study in Four European Cities

Science.gov (United States)

Ruijsbroek, Annemarie; Droomers, Mariël; Kruize, Hanneke; van Kempen, Elise; Gidlow, Christopher J.; Hurst, Gemma; Andrusaityte, Sandra; Nieuwenhuijsen, Mark J.; Maas, Jolanda; Hardyns, Wim; Stronks, Karien; Groenewegen, Peter P.

2017-01-01

It has been suggested that certain residents, such as those with a low socioeconomic status, the elderly, and women, may benefit more from the presence of neighbourhood green space than others. We tested this hypothesis for age, gender, educational level, and employment status in four European cities. Data were collected in Barcelona (Spain; n = 1002), Kaunas (Lithuania; n = 989), Doetinchem (The Netherlands; n = 847), and Stoke-on-Trent (UK; n = 933) as part of the EU-funded PHENOTYPE project. Surveys were used to measure mental and general health, individual characteristics, and perceived neighbourhood green space. Additionally, we used audit data about neighbourhood green space. In Barcelona, there were positive associations between neighbourhood green space and general health among low-educated residents. In the other cities and for the other population groups, there was little evidence that the association between health and neighbourhood green space differed between population groups. Overall, our study does not support the assumption that the elderly, women, and residents who are not employed full-time benefit more from neighbourhood green space than others. Only in the highly urbanised city of Barcelona did the low-educated group benefit from neighbourhood green spaces. Perhaps neighbourhood green spaces are more important for the health of low-educated residents in particularly highly urbanised areas. PMID:28594390

Does the Health Impact of Exposure to Neighbourhood Green Space Differ between Population Groups? An Explorative Study in Four European Cities.

Science.gov (United States)

Ruijsbroek, Annemarie; Droomers, Mariël; Kruize, Hanneke; van Kempen, Elise; Gidlow, Christopher J; Hurst, Gemma; Andrusaityte, Sandra; Nieuwenhuijsen, Mark J; Maas, Jolanda; Hardyns, Wim; Stronks, Karien; Groenewegen, Peter P

2017-06-08

It has been suggested that certain residents, such as those with a low socioeconomic status, the elderly, and women, may benefit more from the presence of neighbourhood green space than others. We tested this hypothesis for age, gender, educational level, and employment status in four European cities. Data were collected in Barcelona (Spain; n = 1002), Kaunas (Lithuania; n = 989), Doetinchem (The Netherlands; n = 847), and Stoke-on-Trent (UK; n = 933) as part of the EU-funded PHENOTYPE project. Surveys were used to measure mental and general health, individual characteristics, and perceived neighbourhood green space. Additionally, we used audit data about neighbourhood green space. In Barcelona, there were positive associations between neighbourhood green space and general health among low-educated residents. In the other cities and for the other population groups, there was little evidence that the association between health and neighbourhood green space differed between population groups. Overall, our study does not support the assumption that the elderly, women, and residents who are not employed full-time benefit more from neighbourhood green space than others. Only in the highly urbanised city of Barcelona did the low-educated group benefit from neighbourhood green spaces. Perhaps neighbourhood green spaces are more important for the health of low-educated residents in particularly highly urbanised areas.

R-102, 1 Group Space-Independent Inverse Reactor Kinetics

International Nuclear Information System (INIS)

Kaganove, J.J.

1966-01-01

1 - Description of problem or function: Given the space-independent, one energy group reactor kinetics equations and the initial conditions, this program determines the time variation of reactivity required to produce the given input of flux-time data. 2 - Method of solution: Time derivatives of neutron density are obtained by application of (a) five-point quartic, (b) three-point parabolic, (c) five-point least-mean-square cubic, (d) five-point least-mean-square parabolic, or (e) five-point least-mean-square linear formulae to the neutron density or to the natural logarithm of the neutron density. Between each data point the neutron density is assumed to be (a) exponential*(third-order polynomial), (b) exponential, or (c) linear. Changes in reactivity between data points are obtained algebraically from the kinetics equations, neutron density derivatives, and the algebraic representation of neutron density. First and second time derivatives of the reactivity are obtained by use of any of the formulae applicable to the neutron density. 3 - Restrictions on the complexity of the problem: Maxima of - 50 delay groups; 1000 data points; 99 data blocks (A data block is a sequence of input points characterized by a fixed time-interval between points, a smoothing option, and a number of repetitions of the smoothing option)

Space-group approach to two-electron states in unconventional superconductors

International Nuclear Information System (INIS)

Yarzhemsky, V. G.

2008-01-01

The direct application of the space-group representation theory, makes possible to obtain limitations for the symmetry of SOP on lines and planes of symmetry in one-electron Brillouin zone. In the case of highly symmetric UPt 3 only theoretical nodal structure of IR E 2u is in agreement with all the experimental results. On the other hand, in the case of high-T c superconductors the two electron description of Cooper pairs in D 2h symmetry is not sufficient to describe experimental nodal structure. It was shown that in this case, the nodal structure is the result of underlying interactions between two-electron states and hidden symmetry D-4 h . (author)

Thumb carpometacarpal joint congruence during functional tasks and thumb range-of-motion activities

Science.gov (United States)

Halilaj, Eni; Moore, Douglas C; Patel, Tarpit K; Laidlaw, David H; Ladd, Amy L; Weiss, Arnold-Peter C; Crisco, Joseph J

2017-01-01

Joint incongruity is often cited as a possible etiological factor for the high incidence of thumb carpometacarpal (CMC) joint osteoarthritis (OA) in older women. There is evidence suggesting that biomechanics plays a role in CMC OA progression, but little is known about how CMC joint congruence, specifically, differs among different cohorts. The purpose of this in vivo study was to determine if CMC joint congruence differs with sex, age, and early stage OA for different thumb positions. Using CT data from 155 subjects and a congruence metric that is based on both articular morphology and joint posture, we did not find any differences in CMC joint congruence with sex or age group, but found that patients in the early stages of OA exhibit lower congruence than healthy subjects of the same age group. PMID:25570956

Thumb carpometacarpal joint congruence during functional tasks and thumb range-of-motion activities.

Science.gov (United States)

Halilaj, Eni; Moore, Douglas C; Patel, Tarpit K; Laidlaw, David H; Ladd, Amy L; Weiss, Arnold-Peter C; Crisco, Joseph J

2014-01-01

Joint incongruity is often cited as a possible etiological factor for the high incidence of thumb carpometacarpal (CMC) joint osteoarthritis (OA) in older women. There is evidence suggesting that biomechanics plays a role in CMC OA progression, but little is known about how CMC joint congruence, specifically, differs among different cohorts. The purpose of this in vivo study was to determine if CMC joint congruence differs with sex, age, and early stage OA for different thumb positions. Using CT data from 155 subjects and a congruence metric that is based on both articular morphology and joint posture, we did not find any differences in CMC joint congruence with sex or age group, but found that patients in the early stages of OA exhibit lower congruence than healthy subjects of the same age group.

Response to the Comment by G. Emch on projective group representations in quaternionic Hilbert space

International Nuclear Information System (INIS)

Adler, S.L.

1996-01-01

We discuss the differing definitions of complex and quaternionic projective group representations employed by us and by Emch. The definition of Emch (termed here a strong projective representation) is too restrictive to accommodate quaternionic Hilbert space embeddings of complex projective representations. Our definition (termed here a weak projective representation) encompasses such embeddings, and leads to a detailed theory of quaternionic, as well as complex, projective group representations. copyright 1996 American Institute of Physics

Synthesis, CMC Determination, Antimicrobial Activity and Nucleic Acid Binding of A Surfactant Copper(II) Complex Containing Phenanthroline and Alanine Schiff-Base.

Science.gov (United States)

Nagaraj, Karuppiah; Sakthinathan, Subramanian; Arunachalam, Sankaralingam

2014-03-01

A new water-soluble surfactant copper(II) complex [Cu(sal-ala)(phen)(DA)] (sal-ala = salicylalanine, phen = 1,10-phenanthroline, DA = dodecylamine), has been synthesized and characterized by physico-chemical and spectroscopic methods. The critical micelle concentration (CMC) values of this surfactant-copper(II) complex in aqueous solution were obtained from conductance measurements. Specific conductivity data (at 303, 308, 313. 318 and 323 K) served for the evaluation of the temperature-dependent CMC and the thermodynamics of micellization (ΔG(0)m, ΔH(0)m and ΔS(0)m). The interaction of this complex with nucleic acids (DNA and RNA) has been explored by using electronic absorption spectral titration, competitive binding experiment, cyclic voltammetry, circular dichroism (CD) spectra, and viscosity measurements. Electronic absorption studies have revealed that the complex can bind to nucleic acids by the intercalative binding mode which has been verified by viscosity measurements. The DNA binding constants have also been calculated (Kb = 1.2 × 10(5) M(-1) for DNA and Kb = 1.6 × 10(5) M(-1) for RNA). Competitive binding study with ethidium bromide (EB) showed that the complex exhibits the ability to displace the DNA-bound-EB indicating that the complex binds to DNA in strong competition with EB for the intercalative binding site. The presence of hydrophobic ligands, alanine Schiff-base, phenanthroline and long aliphatic chain amine in the complex were responsible for this strong intercalative binding. The surfactant-copper (II) complex was screened for its antibacterial and antifungal activities against various microorganisms. The results were compared with the standard drugs, amikacin(antibacterial) and ketokonazole(antifungal).

Does the Health Impact of Exposure to Neighbourhood Green Space Differ between Population Groups? An Explorative Study in Four European Cities

Directory of Open Access Journals (Sweden)

Annemarie Ruijsbroek

2017-06-01

Full Text Available It has been suggested that certain residents, such as those with a low socioeconomic status, the elderly, and women, may benefit more from the presence of neighbourhood green space than others. We tested this hypothesis for age, gender, educational level, and employment status in four European cities. Data were collected in Barcelona (Spain; n = 1002, Kaunas (Lithuania; n = 989, Doetinchem (The Netherlands; n = 847, and Stoke-on-Trent (UK; n = 933 as part of the EU-funded PHENOTYPE project. Surveys were used to measure mental and general health, individual characteristics, and perceived neighbourhood green space. Additionally, we used audit data about neighbourhood green space. In Barcelona, there were positive associations between neighbourhood green space and general health among low-educated residents. In the other cities and for the other population groups, there was little evidence that the association between health and neighbourhood green space differed between population groups. Overall, our study does not support the assumption that the elderly, women, and residents who are not employed full-time benefit more from neighbourhood green space than others. Only in the highly urbanised city of Barcelona did the low-educated group benefit from neighbourhood green spaces. Perhaps neighbourhood green spaces are more important for the health of low-educated residents in particularly highly urbanised areas.

Statistical Analysis of CMC Constituent and Processing Data

Science.gov (United States)

Fornuff, Jonathan

2004-01-01

Ceramic Matrix Composites (CMCs) are the next "big thing" in high-temperature structural materials. In the case of jet engines, it is widely believed that the metallic superalloys currently being utilized for hot structures (combustors, shrouds, turbine vanes and blades) are nearing their potential limits of improvement. In order to allow for increased turbine temperatures to increase engine efficiency, material scientists have begun looking toward advanced CMCs and SiC/SiC composites in particular. Ceramic composites provide greater strength-to-weight ratios at higher temperatures than metallic alloys, but at the same time require greater challenges in micro-structural optimization that in turn increases the cost of the material as well as increases the risk of variability in the material s thermo-structural behavior. to model various potential CMC engine materials and examines the current variability in these properties due to variability in component processing conditions and constituent materials; then, to see how processing and constituent variations effect key strength, stiffness, and thermal properties of the finished components. Basically, this means trying to model variations in the component s behavior by knowing what went into creating it. inter-phase and manufactured by chemical vapor infiltration (CVI) and melt infiltration (MI) were considered. Examinations of: (1) the percent constituents by volume, (2) the inter-phase thickness, (3) variations in the total porosity, and (4) variations in the chemical composition of the Sic fiber are carried out and modeled using various codes used here at NASA-Glenn (PCGina, NASALife, CEMCAN, etc...). The effects of these variations and the ranking of their respective influences on the various thermo-mechanical material properties are studied and compared to available test data. The properties of the materials as well as minor changes to geometry are then made to the computer model and the detrimental effects

Gauge fields in nonlinear group realizations involving two-dimensional space-time symmetry

International Nuclear Information System (INIS)

Machacek, M.E.; McCliment, E.R.

1975-01-01

It is shown that gauge fields may be consistently introduced into a model Lagrangian previously considered by the authors. The model is suggested by the spontaneous breaking of a Lorentz-type group into a quasiphysical two-dimensional space-time and one internal degree of freedom, loosely associated with charge. The introduction of zero-mass gauge fields makes possible the absorption via the Higgs mechanism of the Goldstone fields that appear in the model despite the fact that the Goldstone fields do not transform as scalars. Specifically, gauge invariance of the Yang-Mills type requires the introduction of two sets of massless gauge fields. The transformation properties in two-dimensional space-time suggest that one set is analogous to a charge doublet that behaves like a second-rank tensor in real four-dimensional space time. The other set suggests a spin-one-like charge triplet. Via the Higgs mechanism, the first set absorbs the Goldstone fields and acquires mass. The second set remains massless. If massive gauge fields are introduced, the associated currents are not conserved and the Higgs mechanism is no longer fully operative. The Goldstone fields are not eliminated, but coupling between the Goldstone fields and the gauge fields does shift the mass of the antisymmetric second-rank-tensor gauge field components

Reviewing the Role of Media Attributes in Mobilizing Protest Participation

NARCIS (Netherlands)

van den Broek, Tijs Adriaan; Ehrenhard, Michel Léon

2014-01-01

Activist groups increasingly use computer-mediated communication (CMC) channels to mobilize large groups of consumers to persuade incumbent firms to change their contested strategies or practices. The attributes of CMC channels change the effectiveness of persuasion processes in organizations.

Promoting Practices : How Activists Employ Online Tactics to Promote Energy Efficiency

NARCIS (Netherlands)

Renkema, M.; Broek, T.A. van den

2014-01-01

Activist groups increasingly use computer-mediated communication (CMC) channels to mobilize large groups of consumers to persuade incumbent firms to change their contested strategies or practices. The attributes of CMC channels change the effectiveness of persuasion processes in organizations.

A summary of activities of the US/Soviet-Russian joint working group on space biology and medicine

Science.gov (United States)

Doarn, Charles R.; Nicogossian, Arnauld E.; Grigoriev, Anatoly I.; Tverskaya, Galina; Orlov, Oleg I.; Ilyin, Eugene A.; Souza, Kenneth A.

2010-10-01

The very foundation of cooperation between the United States (US) and Russia (former Soviet Union) in space exploration is a direct result of the mutual desire for scientific understanding and the creation of a collaborative mechanism—the Joint Working Group (JWG) on Space Biology and Medicine. From the dawn of the space age, it has been the quest of humankind to understand its place in the universe. While nations can and do solve problems independently, it takes nations, working together, to accomplish great things. The formation of the JWG provided an opportunity for the opening of a series of productive relationships between the superpowers, the US and the Union of Soviet Socialist Republics (USSR); and served as a justification for continued relationship for medical assistance in spaceflight, and to showcase Earth benefits from space medicine research. This relationship has been played out on an international scale with the construction and operation of the International Space Station. The fundamental reason for this successful endeavor is a direct result of the spirit and perseverance of the men and women who have worked diligently side-by-side to promote science and move our understanding of space forward. This manuscript provides a historical perspective of the JWG; how it came about; its evolution; what it accomplished; and what impact it has had and continues to have in the 21st century with regard to human spaceflight and space life sciences research. It captures the spirit of this group, which has been in continuous existence for over 40 years, and provides a never before reported summary of its activities.

Topological and homological properties of the orbit space of a compact linear Lie group with commutative connected component

OpenAIRE

Styrt, O. G.

2016-01-01

The problem in question is whether the quotient space of a compact linear group is a topological manifold and whether it is a homological manifold. In the paper, the case of an infinite group with commutative connected component is considered.

Computer-mediated communication in adults with high-functioning autism spectrum disorders and controls

NARCIS (Netherlands)

van der Aa, Christine; Pollmann, Monique; Plaat, Aske; van der Gaag, Rutger Jan

2016-01-01

It has been suggested that people with Autism Spectrum Disorders (ASD) are attracted to computer-mediated communication (CMC). In this study, we compare CMC use in adults with high-functioning ASD (N = 113) and a control group (N = 72). We find that people with ASD spend more time on CMC than

Torelli groups, extended Johnson homomorphisms, and new cycles on the moduli space of curves

DEFF Research Database (Denmark)

Morita, Shigeyuki; Penner, Robert

modulo N are derived for all N. Furthermore, the first Johnson homomorphism, which is defined from the classical Torelli group to the third exterior power of the homology of the surface, is shown to lift to an explicit canonical 1-cocycle of the Teichmueller space. The main tool for these results...... cocycle lifts of the higher Johnson homomorphisms....

Basic feasibility study on energy conservation at Lianyuan Iron and Steel Group Co., Ltd.

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

For the purpose of conserving energy and reducing greenhouse effect gas emission, a feasibility study was carried out of the installation of energy conservation facilities at the steelworks of Lianyuan Iron and Steel Group Complex, Loudi City, Hunan Province, China. The installation of the following facilities was studied: coke dry quenching (CDQ) equipment, coal moisture control (CMC) equipment, sintering ignition furnace equipment, cooler exhaust heat recovery equipment, top pressure recovery turbine (TRT), and hot stove exhaust heat recovery equipment. As a result of the study, the energy conservation amount was 20,000 toe/y by CDQ, 2,530 toe/y by CMC, 900 toe/y by improvement of ignition furnace in the sintering process, 12,300 toe/y by sintering cooler, 13,200 toe/y by TRT, and 10,300 toe/y by hot stove exhaust heat recovery equipment. Further, the amount of greenhouse effect gas reduction was 61,022 t-CO2/y, 7,843 t-CO2/y, 2,896 t-CO2/y, 38,060 t-CO2/y, 55,295 t-CO2/y, and 40,621 t-CO2/y, respectively. In the estimation of effects vs. expenses, the sintering ignition furnace, sintering cooler exhaust heat recovery, and hot stove exhaust heat recovery indicated the comparatively favorable values. (NEDO)

Analysis of Adult Female Mouse (Mus musculus) Group Behavior on the International Space Station (ISS)

Science.gov (United States)

Solomides, P.; Moyer, E. L.; Talyansky, Y.; Choi, S.; Gong, C.; Globus, R. K.; Ronca, A. E.

2016-01-01

As interest in long duration effects of space habitation increases, understanding the behavior of model organisms living within the habitats engineered to fly them is vital for designing, validating, and interpreting future spaceflight studies. A handful of papers have previously reported behavior of mice and rats in the weightless environment of space. The Rodent Research Hardware and Operations Validation (Rodent Research-1; RR1) utilized the Rodent Habitat (RH) developed at NASA Ames Research Center to fly mice on the ISS (International Space Station). Ten adult (16-week-old) female C57BL/6 mice were launched on September 21st, 2014 in an unmanned Dragon Capsule, and spent 37 days in microgravity. Here we report group behavioral phenotypes of the RR1 Flight (FLT) and environment-matched Ground Control (GC) mice in the Rodent Habitat (RH) during this long-duration flight. Video was recorded for 33 days on the ISS, permitting daily assessments of overall health and well-being of the mice, and providing a valuable repository for detailed behavioral analysis. We previously reported that, as compared to GC mice, RR1 FLT mice exhibited the same range of behaviors, including eating, drinking, exploration, self- and allo-grooming, and social interactions at similar or greater levels of occurrence. Overall activity was greater in FLT as compared to GC mice, with spontaneous ambulatory behavior, including organized 'circling' or 'race-tracking' behavior that emerged within the first few days of flight following a common developmental sequence, and comprised the primary dark cycle activity persisting throughout the remainder of the experiment. Participation by individual mice increased dramatically over the course of the flight. Here we present a detailed analysis of 'race-tracking' behavior in which we quantified: (1) Complete lap rotations by individual mice; (2) Numbers of collisions between circling mice; (3) Lap directionality; and (4) Recruitment of mice into a group

On the Lie symmetry group for classical fields in noncommutative space

Energy Technology Data Exchange (ETDEWEB)

Pereira, Ricardo Martinho Lima Santiago [Universidade Federal da Bahia (UFBA), BA (Brazil); Instituto Federal da Bahia (IFBA), BA (Brazil); Ressureicao, Caio G. da [Universidade Federal da Bahia (UFBA), BA (Brazil). Inst. de Fisica; Vianna, Jose David M. [Universidade Federal da Bahia (UFBA), BA (Brazil); Universidade de Brasilia (UnB), DF (Brazil)

2011-07-01

Full text: An alternative way to include effects of noncommutative geometries in field theory is based on the concept of noncommutativity among degrees of freedom of the studied system. In this context it is reasonable to consider that, in the multiparticle noncommutative quantum mechanics (NCQM), the noncommutativity among degrees of freedom to discrete system with N particles is also verified. Further, an analysis of the classical limit of the single particle NCQM leads to a deformed Newtonian mechanics where the Newton's second law is modified in order to include the noncommutative parameter {theta}{sub {iota}j} and, for a one-dimensional discrete system with N particles, the dynamical evolution of each particle is given by this modified Newton's second law. Hence, applying the continuous limit to this multiparticle classical system it is possible to obtain a noncommutative extension of two -dimensional field theory in a noncommutative space. In the present communication we consider a noncommutative extension of the scalar field obtained from this approach and we analyze the Lie symmetries in order to compare the Lie group of this field with the usual scalar field in the commutative space. (author)

A Phase Transformation with no Change in Space Group Symmetry: Octafluoronaphtalene

DEFF Research Database (Denmark)

Pawley, G. S.; Dietrich, O. W.

1975-01-01

A solid-state phase transformation in octafluoronaphthalene has been discovered at 266.5K on cooling, and at 15K higher on heating. The symmetry of both phases is found to be the same, namely monoclinic with space group P21/c. The unit cell parameters change by up to 10%, but the integrity...... of a single crystal, which shatters on cooling, is good enough for a single-crystal structure determination. This has been done in both phases to a sufficient accuracy that a mechanism for the transformation can be proposed. Molecules which lie parallel to one another shear to a new parallel position...

Effectiveness and short-term safety of modified sodium hyaluronic acid-carboxymethylcellulose at cesarean delivery: a randomized trial.

Science.gov (United States)

Kiefer, Daniel G; Muscat, Jolene C; Santorelli, Jarrett; Chavez, Martin R; Ananth, Cande V; Smulian, John C; Vintzileos, Anthony M

2016-03-01

The rising cesarean birth rate has drawn attention to risks associated with repeat cesarean birth. Prevention of adhesions with adhesion barriers has been promoted as a way to decrease operative difficulty. However, robust data demonstrating effectiveness of such interventions are lacking. We report data from a multicenter trial designed to evaluate the short-term safety and effectiveness of a modified sodium hyaluronic acid (HA)-carboxymethylcellulose (CMC) absorbable adhesion barrier for reduction of adhesions following cesarean delivery. Patients who underwent primary or repeat cesarean delivery were included in this multicenter, single-blinded (patient), randomized controlled trial. Patients were randomized into either HA-CMC (N = 380) or no treatment (N = 373). No other modifications to their treatment were part of the protocol. Short-term safety data were collected following randomization. The location and density of adhesions (primary outcome) were assessed at their subsequent delivery using a validated tool, which can also be used to derive an adhesion score that ranges from 0-12. No differences in baseline characteristics, postoperative course, or incidence of complications between the groups following randomization were noted. Eighty patients from the HA-CMC group and 92 controls returned for subsequent deliveries. Adhesions in any location were reported in 75.6% of the HA-CMC group and 75.9% of the controls (P = .99). There was no significant difference in the median adhesion score; 2 (range 0-10) for the HA-CMC group vs 2 (range 0-8) for the control group (P = .65). One third of the HA-CMC patients met the definition for severe adhesions (adhesion score >4) compared to 15.5% in the control group (P = .052). There were no significant differences in the time from incision to delivery (P = .56). Uterine dehiscence in the next pregnancy was reported in 2 patients in HA-CMC group vs 1 in the control group (P = .60). Although we did not identify any short

Implementation of rigorous renormalization group method for ground space and low-energy states of local Hamiltonians

Science.gov (United States)

Roberts, Brenden; Vidick, Thomas; Motrunich, Olexei I.

2017-12-01

The success of polynomial-time tensor network methods for computing ground states of certain quantum local Hamiltonians has recently been given a sound theoretical basis by Arad et al. [Math. Phys. 356, 65 (2017), 10.1007/s00220-017-2973-z]. The convergence proof, however, relies on "rigorous renormalization group" (RRG) techniques which differ fundamentally from existing algorithms. We introduce a practical adaptation of the RRG procedure which, while no longer theoretically guaranteed to converge, finds matrix product state ansatz approximations to the ground spaces and low-lying excited spectra of local Hamiltonians in realistic situations. In contrast to other schemes, RRG does not utilize variational methods on tensor networks. Rather, it operates on subsets of the system Hilbert space by constructing approximations to the global ground space in a treelike manner. We evaluate the algorithm numerically, finding similar performance to density matrix renormalization group (DMRG) in the case of a gapped nondegenerate Hamiltonian. Even in challenging situations of criticality, large ground-state degeneracy, or long-range entanglement, RRG remains able to identify candidate states having large overlap with ground and low-energy eigenstates, outperforming DMRG in some cases.

The Targeted Antitumor Effects of C- PC/CMC-CD59sp Nanoparticles on HeLa Cells in Vitro and in Vivo.

Science.gov (United States)

Wang, Yujuan; Jiang, Liangqian; Yin, Qifeng; Liu, Huihui; Liu, Guoxiang; Zhu, Guoteng; Li, Bing

2017-01-01

The novel C-PC/CMC-CD59sp-NPs were made by carbocymethyl chitosan (CMC) loading C-phycocyanin (C-PC) with the lead of CD59 specific ligand peptide (CD59sp) for targeting, and the characteristics and targeted anti-tumor mechanism were explored in order to realize the targeted therapy of C-PC on the growth of HeLa cells both in vitro and vivo . The targeting nanoparticles were synthesized by ionic-gelation method, and the optimal condition was selected out by orthogonal analysis. The properties of nanoparticles were observed by laser particle analyzer and dynamic light scattering (DLS) and Fourier Transform Infrared Spectrometer (FTIR). The effects of nanoparticles on the proliferation of HeLa cells in vitro were assessed by MTT assay. The mice model with tumor was constructed by subcutaneous injection of HeLa cells into the left axilla of NU/NU mice. The weight of tumor and the spleen were tested. The expression quantities of cleaved caspase-3, Bcl-2 were determined by western blot and immunofluorescent staining. Results showed the morphology of the finally prepared nanoparticles was well distributed with a diameter distribution of 200±11.3 nm and zeta potential of -19.5±4.12mV. Under the guidance of CD59sp, the targeting nanoparticles could targetedly and efficiently arrive at the surface of HeLa cells, and had obvious inhibitory effect on HeLa cells proliferation both in vitro and vivo. Moreover, the nanoparticles could induce cell apoptosis by up-regulation of cleaved caspase-3 proteins expression, but down-regulation of Bcl-2 and cyclinD1 proteins. Our study provided a new idea for the research and development of marine drugs, and supplied a theoretical support for the target therapy of anticancer drug.

A Topic Space Oriented User Group Discovering Scheme in Social Network: A Trust Chain Based Interest Measuring Perspective

Directory of Open Access Journals (Sweden)

Wang Dong

2016-01-01

Full Text Available Currently, user group has become an effective platform for information sharing and communicating among users in social network sites. In present work, we propose a single topic user group discovering scheme, which includes three phases: topic impact evaluation, interest degree measurement, and trust chain based discovering, to enable selecting influential topic and discovering users into a topic oriented group. Our main works include (1 an overview of proposed scheme and its related definitions; (2 topic space construction method based on topic relatedness clustering and its impact (influence degree and popularity degree evaluation; (3 a trust chain model to take user relation network topological information into account with a strength classification perspective; (4 an interest degree (user explicit and implicit interest degree evaluation method based on trust chain among users; and (5 a topic space oriented user group discovering method to group core users according to their explicit interest degrees and to predict ordinary users under implicit interest and user trust chain. Finally, experimental results are given to explain effectiveness and feasibility of our scheme.

Moduli space of self-dual connections in dimension greater than four for abelian Gauge groups

OpenAIRE

Cappelle, Natacha

2018-01-01

In 1954, C. Yang and R. Mills created a Gauge Theory for strong interaction of Elementary Particles. More generally, they proved that it is possible to define a Gauge Theory with an arbitrary compact Lie group as Gauge group. Within this context, it is interesting to find critical values of a functional defined on the space of connections: the Yang-Mills functional. If the based manifold is four dimensional, there exists a natural notion of (anti-)self-dual 2-form, which gives a natural notio...

Cubic scattering amplitudes for all massless representations of the Poincare group in any space-time dimension

International Nuclear Information System (INIS)

Fradkin, E.S.; Metsaev, R.R.

1996-02-01

Using the language of highest weight representations and the light cone formalism we construct a full list of cubic amplitudes of scattering for all bosonic massless representations of the Poincare group in any even space-time dimension. (author). 29 refs

Clifford algebras, spinors, spin groups and covering groups

International Nuclear Information System (INIS)

Magneville, C.; Pansart, J.P.

1991-03-01

The Dirac equation uses matrices named Υ matrices which are representations of general algebraic structures associated with a metric space. These algebras are the Clifford algebras. In the first past, these algebras are studied. Then the notion of spinor is developed. It is shown that Majorana and Weyl spinors only exist for some particular metric space. In the second part, Clifford and spinor groups are studied. They may be interpreted as the extension of the notion of orthogonal group for Clifford algebras and their spaces for representation. The rotation of a spinor is computed. In the last part, the connexion between the spinor groups and the Universal Covering Groups is presented [fr

Effect of alpha-calciferol on bone mineral density, bone histomorphometry and bone biomechanics in rats by radiative injury to kidney

International Nuclear Information System (INIS)

Zhu Feipeng; Wang Hongfu; Gao Linfeng; Jin Weifang

2003-01-01

The work is to study the effects of alpha-calciferol on bone mineral density, histomorphometry and biomechanics in rats with osteoporosis induced by irradiation of the rat kidney. 32 male SD rats of six months in age were randomly divided into 4 groups (8 rats per group), i.e. the model group, the sham group, the bone one group and the fosamax group. Osteoporosis was developed in the rats by irradiating the kidney. Then the rats were administrated orally as follows in a 90 days, 0.1 g·kg -1 BW.d of alpha-calciferol for the bone one group, 10 mg·kg -1 BW.d of alendronate sodium in 1 mL CMC for the fosamax group, and 1 mL CMC for both the model group and sham group. BMD of L1-4, bone histomorphometry and the bone biomechanical properties were measured. Compared with the model group, both the bone one group and the fosamax group were characterized with significantly higher BMD of L1-4 (p<0.01), significantly larger volume and width of bone trabecula, smaller space of bone trabecula (p<0.05, p<0.01), and significantly larger maximal stress of femur and lumbar vertebra (p<0.05, p<0.01). It is concluded that Alpha-calciferol can improve BMD, bone histomorphometry and bone biomechanical properties in rat osteoporosis induced by kidney irradiation

The Impact of Telehealth and Care Coordination on the Number and Type of Clinical Visits for Children With Medical Complexity.

Science.gov (United States)

McKissick, Holly D; Cady, Rhonda G; Looman, Wendy S; Finkelstein, Stanley M

The purpose of this analysis was to evaluate the effects of an advanced practice nurse-delivered telehealth intervention on health care use by children with medical complexity (CMC). Because CMC account for a large share of health care use costs, finding effective ways to care for them is an important challenge requiring exploration. This was a secondary analysis of data from a randomized clinical trial with a control group and two intervention groups. The focus of the analysis was planned and unplanned clinical and therapy visits by CMC over a 30-month data collection period. Nonparametric tests were used to compare visit counts among and within the three groups. The number of unplanned visits decreased over time across all groups, with the greatest decrease in the video telehealth intervention group. Planned visits were higher in the video telehealth group across all time periods. Advanced practice registered nurse-delivered telehealth care coordination may support a shift from unplanned to planned health care service use among CMC. Copyright © 2016 National Association of Pediatric Nurse Practitioners. Published by Elsevier Inc. All rights reserved.

The Group Evacuation Behavior Based on Fire Effect in the Complicated Three-Dimensional Space

Directory of Open Access Journals (Sweden)

Jun Hu

2014-01-01

Full Text Available In order to effectively depict the group evacuation behavior in the complicated three-dimensional space, a novel pedestrian flow model is proposed with three-dimensional cellular automata. In this model the calculation methods of floor field and fire gain are elaborated at first, and the transition gain of target position at the next moment is defined. Then, in consideration of pedestrian intimacy and velocity change, the group evacuation strategy and evolution rules are given. Finally, the experiments were conducted with the simulation platform to study the relationships of evacuation time, pedestrian density, average system velocity, and smoke spreading velocity. The results had shown that large-scale group evacuation should be avoided, and in case of large pedestrian density, the shortest route of evacuation strategy would extend system evacuation time.

Quantum spaces, central extensions of Lie groups and related quantum field theories

Science.gov (United States)

Poulain, Timothé; Wallet, Jean-Christophe

2018-02-01

Quantum spaces with su(2) noncommutativity can be modelled by using a family of SO(3)-equivariant differential *-representations. The quantization maps are determined from the combination of the Wigner theorem for SU(2) with the polar decomposition of the quantized plane waves. A tracial star-product, equivalent to the Kontsevich product for the Poisson manifold dual to su(2) is obtained from a subfamily of differential *-representations. Noncommutative (scalar) field theories free from UV/IR mixing and whose commutative limit coincides with the usual ϕ 4 theory on ℛ3 are presented. A generalization of the construction to semi-simple possibly non simply connected Lie groups based on their central extensions by suitable abelian Lie groups is discussed. Based on a talk presented by Poulain T at the XXVth International Conference on Integrable Systems and Quantum symmetries (ISQS-25), Prague, June 6-10 2017.

Extreme covariant quantum observables in the case of an Abelian symmetry group and a transitive value space

International Nuclear Information System (INIS)

Haapasalo, Erkka Theodor; Pellonpaeae, Juha-Pekka

2011-01-01

We represent quantum observables as normalized positive operator valued measures and consider convex sets of observables which are covariant with respect to a unitary representation of a locally compact Abelian symmetry group G. The value space of such observables is a transitive G-space. We characterize the extreme points of covariant observables and also determine the covariant extreme points of the larger set of all quantum observables. The results are applied to position, position difference, and time observables.

Modification of Natural Polymers by Radiation-Induced Processing for Versatile Applications

International Nuclear Information System (INIS)

Nagasawa, N.; Hiroki, A.; Tamada, M.

2010-01-01

Radiation-crosslinking mechanism of polysaccharide derivatives such as carboxymethyl cellulose (CMC), carboxymethyl chitosan (CMCts) is not clarified yet. Radicals in CMC formed by reaction with OH radical were studied by ESR in order to elucidate the radiation-crosslinking mechanism of CMC. ESR spectra implied that radicals were created on carboxymethyl groups linked to C2, C3 and C6 of glucose unit in CMC. The radicals of CMCts were also created on carboxymethyl groups linked to C3 and C6 of glusamine unit. For application of carboxymethyl cellulose (CMC) to a super water-adsorbent, gel fraction should be adjusted to the range of 50%. It was found that gel fraction of CMC could be control by the irradiation temperature of CMC aqueous paste-like state. Poly(L-lactic acid)(PLLA) could be crosslinked when it was irradiated with coexistence of crosslinker, triallyl isocyanurate. However, the crosslinked PLLA is thermally deformed under the stress at 70 °C. The thermo mechanical stability of PLLA was further improved by the adding SiO 2 and the post heating at 90 °C. The storage modulus of the treated PLLA showed about 100 times higher than that of only crosslinked PLLA. The improved materials was applied to demonstration lens of eyewear. (author)

The effect of sodium hyaluronate-carboxymethyl cellulose membrane in the prevention of parenchymal air leaks: an experimental and manometric study in rats.

Science.gov (United States)

Büyükkale, Songül; Çıtak, Necati; İşgörücü, Özgür; Sayar, Adnan

2017-12-01

We aimed to examine effectiveness of sodium hyaluronate-carboxymethly cellulose (NaH/CMC) for sealing pulmonary air leaks during postoperative period. The study was conducted in 16 male Sprague-Dawley rats. A linear insicion (length= 0.2 cm, depth= 0.1 cm) to the lung parenchyma on the inflated by a cutter was made. The animals were randomly divided; the control group (n= 8) and NaH/CMC-treated group (the study group, n= 8). Control group was left for physiologic healing while a NaH/CMC membrane was applied over the the incisional area in the study group. Then the pressure point where the air leakage observed was noted. No polymorphonucleer leucocytes (PMNL) infiltration was detected in control group, whereas PMNL infiltration was 0.38 ± 0.5 cell per 100 high field in study group (p= 0.234). The degree of macrophage, lymphocyte infiltration and the mean fibroblast count were found to be higher in study group compared with control group (p= 0.007, p= 0.02, p= 0.05, respectively). The mean pressure value for air leak to occur in the control group was 43.50 ± 9.55 mmHg whereas it was 73.75 ± 16.68 mmHg in the study group (p< 0.001). The data revealed that bioabsorbable NaH/CMC membrane accelerates healing with preserving the expansile character of lung parenchyma even in high ventilation pressures. However, further studies are required to assess the prevent impact of the pulmonary air-leak for NaH/CMC membrane.

Appendicular bone mass and knee and hand osteoarthritis in Japanese women: a cross-sectional study

Directory of Open Access Journals (Sweden)

Moji Kazuhiko

2002-10-01

Full Text Available Abstract Background It has been reported that there is an inverse association between osteoarthritis (OA and osteoporosis. However, the relationship of bone mass to OA in a Japanese population whose rates of OA are different from Caucasians remains uncertain. Methods We studied the association of appendicular bone mineral density (second metacarpal; mBMD and quantitative bone ultrasound (calcaneus; stiffness index with knee and hand OA among 567 Japanese community-dwelling women. Knee and hand radiographs were scored for OA using Kellgren-Lawrence (K/L scales. In addition, we evaluated the presence of osteophytes and of joint space narrowing. The hand joints were examined at the distal and proximal interphalangeal (DIP, PIP and first metacarpophalangeal/carpometacarpal (MCP/CMC joints. Results After adjusting for age and body mass index (BMI, stiffness index was significantly higher in women with K/L scale, grade 3 at CMC/MCP joint compared with those with no OA. Adjusted means of stiffness index and mBMD were significantly higher in women with definite osteophytes at the CMC/MCP joint compared to those without osteophytes, whereas there were no significant differences for knee, DIP and PIP joints. Stiffness index, but not mBMD, was higher in women with definite joint space narrowing at the CMC/MCP joint compared with those with no joint space narrowing. Conclusions Appendicular bone mass was increased with OA at the CMC/MCP joint, especially among women with osteophytes. Our findings suggest that the association of peripheral bone mass with OA for knee, DIP or PIP may be less clearcut in Japanese women than in other populations.

Creating social spaces to tackle AIDS-related stigma: reviewing the role of church groups in Sub-Saharan Africa.

Science.gov (United States)

Campbell, C; Skovdal, M; Gibbs, A

2011-08-01

An expanding body of literature explores the role of African church groups in facilitating or hindering the support of people living with AIDS and challenging or contributing to HIV/AIDS-related stigma. Treating church groups as social spaces in which HIV/AIDS-related stigma may potentially be challenged, we systematically review this literature, identifying five themes that highlight the complex and contradictory role of the church as a potential agent of health-enhancing social change. In many ways the church perpetuates HIV/AIDS-related stigma through (i) moralistic attitudes and (ii) its reinforcement of conservative gender ideologies. However some churches have managed move towards action that makes a more positive contribution to HIV/AIDS management through (iii) promoting various forms of social control for HIV prevention, (iv) contributing to the care and support of the AIDS-affected and (v) providing social spaces for challenging stigmatising ideas and practices. We conclude that church groups, including church leadership, can play a key role in facilitating or hindering the creation of supportive social spaces to challenge stigma. Much work remains to be done in developing deeper understandings of the multi-layered factors that enable some churches, but not others, to respond effectively to HIV/AIDS.

基于MUSIC-Group Delay算法的相邻相干信号源定位%Closely spaced coherent-source localization based on MUSIC-group delay algorithm

Institute of Scientific and Technical Information of China (English)

郑家芝

2016-01-01

为了准确的进行相邻的相干信号源定位，提出了一种基于多重信号分类群延迟(MUSIC-group delay)的改进算法。首先，将空间平滑技术引入到波达方向(DoA)估计当中去除部分相干信号。由于在信号源相邻的情况下子空间算法的性能降低，就结合了 MUSIC-Group Delay算法来区分相邻的信号源，这种方法因为自身的加和性通过 MUSIC 相位谱来计算群延迟函数，从而能估计出相邻的信号源。理论分析和仿真结果表明提出的方法估计相邻的相干信号源比子空间算法更精确，分辨率更高。%In this paper,the closely spaced coherent-source localization is considered,and an improved method based on the group delay of Multiple Signal Classification (MUSIC)is presented.Firstly,we introduce the spatial smoothing technique into direction of arrival (DoA)estimation to get rid of the coherent part of signals.Due to the degraded per-formance of sub-space based methods on the condition of nearby sources,we then utilize the MUSIC-Group Delay algo-rithm to distinguish the closely spaced sources,which can resolve spatially close sources by the use of the group delay function computed from the MUSIC phase spectrum for efficient DoA estimation owing to its spatial additive property. Theoretical analysis and simulation results demonstrate that the proposed approach can estimate the DoA of the coherent close signal sources more precisely and have higher resolution compared with sub-space based methods.

Group vector space method for estimating enthalpy of vaporization of organic compounds at the normal boiling point.

Science.gov (United States)

Wenying, Wei; Jinyu, Han; Wen, Xu

2004-01-01

The specific position of a group in the molecule has been considered, and a group vector space method for estimating enthalpy of vaporization at the normal boiling point of organic compounds has been developed. Expression for enthalpy of vaporization Delta(vap)H(T(b)) has been established and numerical values of relative group parameters obtained. The average percent deviation of estimation of Delta(vap)H(T(b)) is 1.16, which show that the present method demonstrates significant improvement in applicability to predict the enthalpy of vaporization at the normal boiling point, compared the conventional group methods.

Silver/polysaccharide-based nanofibrous materials synthesized from green chemistry approach.

Science.gov (United States)

Martínez-Rodríguez, M A; Garza-Navarro, M A; Moreno-Cortez, I E; Lucio-Porto, R; González-González, V A

2016-01-20

In this contribution a novel green chemistry approach for the synthesis of nanofibrous materials based on blends of carboxymethyl-cellulose (CMC)-silver nanoparticles (AgNPs) composite and polyvinyl-alcohol (PVA) is proposed. These nanofibrous materials were obtained from the electrospinning of blends of aqueous solutions of CMC-AgNPs composite and PVA, which were prepared at different CMC/PVA weight ratios in order to electrospin nanofibers applying a constant tension of 15kV. The synthesized materials were characterized by means of transmission electron microscopy, scanning electron microscopy; as well as Fourier-transform infrared, ultraviolet and Raman spectroscopic techniques. Experimental evidence suggests that the diameter of the nanofibers is thinner than any other reported in the literature regarding the electrospinning of CMC. This feature is related to the interactions of AgNPs with carboxyl functional groups of the CMC, which diminish those between the later and acetyl groups of PVA. Copyright © 2015 Elsevier Ltd. All rights reserved.

Knot wormholes and the dimensional invariant of exceptional Lie groups and Stein space hierarchies

International Nuclear Information System (INIS)

Elokaby, Ayman

2009-01-01

The present short note points out a most interesting and quite unexpected connection between the number of distinct knot as a function of their crossing number and exceptional Lie groups and Stein space hierarchies. It is found that the crossing number 7 plays the role of threshold similar to 4 and 5 in E-infinity theory and for the 11 crossing the number of distinct knots is very close to 4α-bar 0 +1=548+1=549, where α-bar 0 =137 is the inverse integer electromagnetic fine structure constant. This is particularly intriguing in view of a similar relation pertinent to the 17 two and three Stein spaces where the total dimension is Σ 1 17 Stein=5α-bar 0 +1=685+1=686, as well as the sum of the eight exceptional Lie symmetry groups Σ i=1 8 |E i |=4α-bar 0 =548. The slight discrepancy of one is explained in both cases by the inclusion of El Naschie's transfinite corrections leading to Σ i=1 8 |E i |=(4)(137+k 0 )=548.328157 and Σ i=1 17 Stein=(5)(137+k 0 )=685.41097, where k o = φ 5 (1 - φ 5 ) and φ=(√(5)-1)/2.

Geometric group theory

CERN Document Server

Druţu, Cornelia

2018-01-01

The key idea in geometric group theory is to study infinite groups by endowing them with a metric and treating them as geometric spaces. This applies to many groups naturally appearing in topology, geometry, and algebra, such as fundamental groups of manifolds, groups of matrices with integer coefficients, etc. The primary focus of this book is to cover the foundations of geometric group theory, including coarse topology, ultralimits and asymptotic cones, hyperbolic groups, isoperimetric inequalities, growth of groups, amenability, Kazhdan's Property (T) and the Haagerup property, as well as their characterizations in terms of group actions on median spaces and spaces with walls. The book contains proofs of several fundamental results of geometric group theory, such as Gromov's theorem on groups of polynomial growth, Tits's alternative, Stallings's theorem on ends of groups, Dunwoody's accessibility theorem, the Mostow Rigidity Theorem, and quasiisometric rigidity theorems of Tukia and Schwartz. This is the f...

Space, time and group identity in Jubilees 8-9

African Journals Online (AJOL)

p1243322

This paper investigates this change in communication strategy and ... his orientation towards and organisation of space, as revealed in his ideas ..... two versions of the same tradition or the parallel development of an older, .... In the case of Numbers Israel ... with its chronological system of jubilees and heavenly space.

Classifying spaces with virtually cyclic stabilizers for linear groups

DEFF Research Database (Denmark)

Degrijse, Dieter Dries; Köhl, Ralf; Petrosyan, Nansen

2015-01-01

We show that every discrete subgroup of GL(n, ℝ) admits a finite-dimensional classifying space with virtually cyclic stabilizers. Applying our methods to SL(3, ℤ), we obtain a four-dimensional classifying space with virtually cyclic stabilizers and a decomposition of the algebraic K-theory of its...

Synthesis and Characterization Pectin-Carboxymethyl Chitosan crosslinked PEGDE as biosorbent of Pb(II) ion

Science.gov (United States)

Hastuti, Budi; Siswanta, Dwi; Mudasir; Triyono

2018-01-01

Pectin and chitosan are biodegradable polymers, potentially applied as a heavy metal adsorbents. Unfortunately both biosorbents pectin and chitosan have a weakness in acidic media. For this purpose required modified pectin and chitosan. The modified adsorben is intended to obtain a stable adsorbent and resistance under acid. The research was done by experimental method in laboratory. The stages of this research are the synthesis of carboxymethyl chitosan (CMC), synthesis of Pec-CMC-PEGDE film adsorbent, stabily test under acid, the characterization of active group using FTIR, stability characterization of Pec-CMC-PEGDE powder adsorbent using XRD, termo stability using DTA-TGA. The results of the research have shown that: pectin and CMC can be cross-linked using PEGDE crosslinking agent, the film adsorbent was stable under HCl 1 M, the film adsorbent have active group comprise of carboxylate and amine groups. The result of characterization using XRD, shows that the adsorbent is semi-crystalline. Base on termo stability, the film adsorbent Pec-CMC-PEGDE stable up to 600°C. The film can be applied as an adsobent of Pb (II) ion remediation. The optimum pH of pec-CMC-PEGDE in adsorbed of Pb(II) was reached at pH 5 with 99.99% absorbent adsorbed and of and adsorption capacity was 46.11 mg/g.

Smile attractiveness related to buccal corridor space in 3 different facial types: A perception of 3 ethnic groups of Malaysians.

Science.gov (United States)

Nimbalkar, Smita; Oh, Yih Y; Mok, Reei Y; Tioh, Jing Y; Yew, Kai J; Patil, Pravinkumar G

2018-03-16

Buccal corridor space and its variations greatly influence smile attractiveness. Facial types are different for different ethnic populations, and so is smile attractiveness. The subjective perception of smile attractiveness of different populations may vary in regard to different buccal corridor spaces and facial patterns. The purpose of this study was to determine esthetic perceptions of the Malaysian population regarding the width of buccal corridor spaces and their effect on smile esthetics in individuals with short, normal, and long faces. The image of a smiling individual with a mesofacial face was modified to create 2 different facial types (brachyfacial and dolicofacial). Each face form was further modified into 5 different buccal corridors (2%, 10%, 15%, 22%, and 28%). The images were submitted to 3 different ethnic groups of evaluators (Chinese, Malay, Indian; 100 each), ranging between 17 and 21 years of age. A visual analog scale (50 mm in length) was used for assessment. The scores given to each image were compared with the Kruskal-Wallis test, and pairwise comparison was performed using the Mann-Whitney U test (α=.05). All 3 groups of evaluators could distinguish gradations of dark spaces in the buccal corridor at 2%, 10%, and 28%. Statistically significant differences were observed among 3 groups of evaluators in esthetic perception when pairwise comparisons were performed. A 15% buccal corridor was found to score esthetically equally within 3 face types by all 3 groups of evaluators. The Indian population was more critical in evaluation than the Chinese or Malay populations. In a pairwise comparison, more significant differences were found between long and short faces and the normal face; the normal face was compared with long and short faces separately. The width of the buccal corridor space influences smile attractiveness in different facial types. A medium buccal corridor (15%) is the esthetic characteristic preferred by all groups of evaluators

WORKSHOP: Inner space - outer space

International Nuclear Information System (INIS)

Anon.

1984-01-01

During the first week of May, the Fermilab theoretical astrophysics group hosted an international conference on science at the interface of particle physics and cosmology/astrophysics. The conference (Inner Space-Outer Space) was attended by a very diverse group of more than 200 physical scientists, including astronomers, astrophysicists, cosmologists, low-temperature physicists, and elementary particle theorists and experimentalists. The common interest which brought this diverse group to gether is the connection between physics on the smallest scale probed by man - the realm of elementary particle physics - and physics on the largest scale imaginable (the entire Universe) - the realm of cosmology

WORKSHOP: Inner space - outer space

Energy Technology Data Exchange (ETDEWEB)

Anon.

1984-09-15

During the first week of May, the Fermilab theoretical astrophysics group hosted an international conference on science at the interface of particle physics and cosmology/astrophysics. The conference (Inner Space-Outer Space) was attended by a very diverse group of more than 200 physical scientists, including astronomers, astrophysicists, cosmologists, low-temperature physicists, and elementary particle theorists and experimentalists. The common interest which brought this diverse group to gether is the connection between physics on the smallest scale probed by man - the realm of elementary particle physics - and physics on the largest scale imaginable (the entire Universe) - the realm of cosmology.

Management of post-LASIK dry eye: a multicenter randomized comparison of a new multi-ingredient artificial tear to carboxymethylcellulose

Directory of Open Access Journals (Sweden)

Wallerstein A

2018-05-01

Full Text Available Avi Wallerstein,1,2 W Bruce Jackson,3 Jeffrey Chambers,4 Amir M Moezzi,5 Hugh Lin,6 Peter A Simmons6 1Department of Ophthalmology, McGill University, Montreal, QC, Canada; 2LASIK MD, Montreal, QC, Canada; 3University of Ottawa Eye Institute of the Ottawa Hospital, Ottawa, ON, Canada; 4Kelowna Eye Care Center, Kelowna, BC, Canada; 5Centre for Ocular Research & Education (CORE, formerly Centre for Contact Lens Research, School of Optometry & Vision Science, University of Waterloo, Waterloo, ON, Canada; 6Allergan Clinical Research, Allergan plc, Irvine, CA, USA Purpose: To compare the efficacy and safety of a preservative-free, multi-ingredient formulation of carboxymethylcellulose 0.5%, hyaluronic acid 0.1%, and organic osmolytes (CMC-HA, to preservative-free carboxymethylcellulose 0.5% (CMC in the management of postoperative signs and symptoms of dry eye following laser-assisted in situ keratomileusis (LASIK. Methods: This was a double-masked, randomized, parallel-group study conducted in 14 clinical centers in Canada and Australia. Subjects with no more than mild dry eye instilled CMC-HA or CMC for 90 days post-LASIK. Ocular Surface Disease Index© (OSDI; primary efficacy measure, corneal staining, tear break-up time (TBUT, Schirmer’s test, acceptability/tolerability surveys, and visual acuity were assessed at screening and days 2, 10, 30, 60, and 90 post-surgery. Safety analyses included all enrolled. Results: A total of 148 subjects (CMC-HA, n=75; CMC, n=73 were enrolled and assigned to receive treatment, and 126 subjects completed the study without any protocol violations. Post-LASIK, dry eye signs/symptoms peaked at 10 days. OSDI scores for both groups returned to normal with no differences between treatment groups at day 90 (P=0.775. Corneal staining, Schirmer’s test, TBUT, and survey results were comparable. Higher mean improvements in uncorrected visual acuity were observed in the CMC-HA group at all study visits, reaching

A generalized Wigner function on the space of irreducible representations of the Weyl-Heisenberg group and its transformation properties

International Nuclear Information System (INIS)

Ibort, A; Man'ko, V I; Marmo, G; Simoni, A; Ventriglia, F

2009-01-01

A natural extension of the Wigner function to the space of irreducible unitary representations of the Weyl-Heisenberg group is discussed. The action of the automorphisms group of the Weyl-Heisenberg group onto Wigner functions and their generalizations and onto symplectic tomograms is elucidated. Some examples of physical systems are considered to illustrate some aspects of the characterization of the Wigner functions as solutions of differential equations

The 64-MSCT study of relationship between renal corticomedullary differentiation, contrast between renal cortex and medulla, renal cortex and medulla CT peak value with the single renal function in hydronephrotic kidney

International Nuclear Information System (INIS)

Wang Yunhua; Hou Weiwei; Liu Ruihong; He Jianjun; Zhi Ke

2009-01-01

Objective: To study 64-MSCT perfusion imaging features about renal corticomedullary differentiation, contrast between renal cortex and medulla (CMC), renal cortex and medulla CT peak value in normal and hydronephrotic kidneys, and to explore the relationship between them and the unilateral renal function. Methods: Thirty-six patients with obstructive nephrohydrosis underwent 64-MSCT perfusion scanning. The split renal glomerular filtration rates (GFR) of their kidneys were measured by SPECT renal dynamic imaging. The 72 kidneys were divided into groups of normal renal function group, mild and severe renal impairment groups according to GFR. Renal corticomedullary differentiation on CT images was graded as clear, obscure, part clear. The CT intensity of cortex and medulla was measured in order to calculate contrast between renal cortex and medulla (CMC). Using Pearson correlation test, the correlation between them and renal GFR were examined. Results: (1) In the 24 kidneys of normal group, all kidneys showed clear CMD. In the 21 kidneys of mild renal impairment group, 14 kidneys showed clear CMD, 2 showed obscure CMD and 5 showed part clear of CMD. In the 27 kidneys of severe renal impairment group, 7 kidneys showed clear CMD, 5 showed obscure CMD and 15 showed part clear of CMD. (2)The CMC of normal group was 0.62 ± 0.20, while it was 0.52 ± 0.14 and 0.37 ± 0.11 for mild renal impairment group and severe renal impairment group CMC respectively. The CMC had positive linear correlation with GFR (r=0.536,P<0.05). (3) The renal cortex and medulla CT peak value of normal group were (133 ± 22) and (104 ± 16) HU; The renal cortex and medulla CT peak value of mild renal impairment group were (91 ± 29) and (76 ± 25) HU; The renal cortex and medulla CT peak value of severe renal impairment group were (68 ± 24) and (57 ± 21) HU(F=42.76 and 32.68,P<0.05). The renal cortex and medulla CT peak value had positive linear correlation with GFR (r=0.672 and 0.623, P<0

Plasticity of premotor cortico-muscular coherence in severely impaired stroke patients with hand paralysis.

Science.gov (United States)

Belardinelli, Paolo; Laer, Leonard; Ortiz, Erick; Braun, Christoph; Gharabaghi, Alireza

2017-01-01

Motor recovery in severely impaired stroke patients is often very limited. To refine therapeutic interventions for regaining motor control in this patient group, the functionally relevant mechanisms of neuronal plasticity need to be detected. Cortico-muscular coherence (CMC) may provide physiological and topographic insights to achieve this goal. Synchronizing limb movements to motor-related brain activation is hypothesized to reestablish cortico-motor control indexed by CMC. In the present study, right-handed, chronic stroke patients with right-hemispheric lesions and left hand paralysis participated in a four-week training for their left upper extremity. A brain-robot interface turned event-related beta-band desynchronization of the lesioned sensorimotor cortex during kinesthetic motor-imagery into the opening of the paralyzed hand by a robotic orthosis. Simultaneous MEG/EMG recordings and individual models from MRIs were used for CMC detection and source reconstruction of cortico-muscular connectivity to the affected finger extensors before and after the training program. The upper extremity-FMA of the patients improved significantly from 16.23 ± 6.79 to 19.52 ± 7.91 (p = 0.0015). All patients showed significantly increased CMC in the beta frequency-band, with a distributed, bi-hemispheric pattern and considerable inter-individual variability. The location of CMC changes was not correlated to the severity of the motor impairment, the motor improvement or the lesion volume. Group analysis of the cortical overlap revealed a common feature in all patients following the intervention: a significantly increased level of ipsilesional premotor CMC that extended from the superior to the middle and inferior frontal gyrus, along with a confined area of increased CMC in the contralesional premotor cortex. In conclusion, functionally relevant modulations of CMC can be detected in patients with long-term, severe motor deficits after a brain-robot assisted

Effect of carboxymethylcellulose on potassium bitartrate crystallization on model solution and white wine

Science.gov (United States)

Bajul, Audrey; Gerbaud, Vincent; Teychene, Sébastien; Devatine, Audrey; Bajul, Gilles

2017-08-01

Instability in bottled wines refer to tartaric salts crystallization such as potassium bitartrate (KHT). It is not desirable as consumers see the settled salts as an evidence of a poor quality control. In some cases, it causes excessive gushing in sparkling wine. We investigate the effect of two oenological carboxymethylcellulose (CMC) for KHT inhibition in a model solution of white wine by studying the impact of some properties of CMC such as the degree of polymerization, the degree of substitution, and the apparent dissociation constant determined by potentiometric titration. Polyelectrolyte adsorption is used for determining the surface and total charge and for providing information about the availability of CMC charged groups for interacting with KHT crystal faces. The inhibitory efficiency of CMC on model solution is evaluated by measuring the induction time with the help of conductimetric methods. Crystals growth with and without CMC are studied by observation with MEB and by thermal analysis using DSC. The results confirm the effectiveness of CMC as an inhibitor of KHT crystallization in a model solution. The main hypothesis of the mechanism lies in the interaction of dissociated anionic carboxymethyl groups along the cellulose backbone with positively charged layers on KHT faces like the {0 1 0} face. Key factors such as pH, CMC chain length and total charge are discusses.

Real-space renormalization group; application to site percolation in square lattice

International Nuclear Information System (INIS)

Tsallis, C.; Schwachheim, G.

1978-05-01

The real-space renormalization group proposed by Reynolds, Klein and Stanley 1977 to treat the site percolation is analysed and extended . The best among 3 possible definitions of 'percolating' configurations and among 5 possible methods to weight these configurations, are established for percolation in square lattices. The use of n xn square clusters leads, for n = 2 (RKS), n = 3 and n = 4, to √ sub (p) approximately equal to 1.635, √ sub(p) approximately equal to 1.533 and √ sub(p) approximately equal to 1.498, and also to P sub(c) approximately equal to 0.382, P sub(c) approximately equal to 0.388 and P sub(c) approximately equal to 0.398, exhibiting in this way the correct (but slow) tendency towards the best up to date values [pt

Design, characterization and in vitro evaluation of a novel thiolated polymer: preactivated carboxymethyl cellulose.

Science.gov (United States)

Laffleur, Flavia; Bacher, Lukas; Netsomboon, Kesinee

2016-01-01

To design a novel preactived carboxymethyl cellulose derivative. First, carboxymethyl cellulose (CMC) was chemically modified by amide bond formation between primary amino group of cysteine (CYS) and carboxylic moiety of CMC mediated by carbodiimide. Second, obtained CMCCYS was preactivated with 2,2'-dithiodinicotinic acid. Designed CMC-S-S-MNA was characterized by FT-IR. Furthermore, cytotoxicity was conducted on Caco-2 cell line. Swelling behavior, erosion and release of novel CMC-S-S-MNA were performed compared with thiolated and unmodified cellulose, respectively. CMC-S-S-MNA showed no harmful effect on cells. CMC-S-S-MNA exhibited 2.13-fold higher stability in comparison to unmodified cellulose. Furthermore, preactivated carboxymethyl cellulose-cysteine revealed 1.9-fold controlled released compared with respective unmodified carboxymethyl cellulose. Novel preactivated carboxymethyl cellulose represents a versatile excipient for drug delivery.

Location preferences of groups in public leisure spaces: the case of Likya Cafe in Ankara

OpenAIRE

Altay, Can

1999-01-01

Ankara : Department of Interior Architecture and Environmental Design and Institute of Economics and Social Sciences, Bilkent Univ., 1999. Thesis (Master's) -- Bilkent University, 1999. Includes bibliographical references. In this study, public leisure spaces are examined considering the social and spatial behavior of occupant groups. After an introduction to the concepts of leisure, its types, its relations with public life and cultural concepts, the study discusses leisure ...

Groups on transformations in Finslerian spaces

International Nuclear Information System (INIS)

Misra, R.B.

1993-01-01

The article first appeared in the Internal Reports of the ICTP in 1981. Since then the topic has attracted a large number of authors and several contributions have been made thereafter. Thus, a previous work of the author is revised and up-dated here including the post-1981 contributions in the field. Infinitesimal transformations defining motions, affine motions, projective motions, conformal transformations and curvature collineations in various types of Finslerian spaces are discussed here. The notation and symbolism used in the paper is mainly based on the author's works. (author). 72 refs

Realizing spaces as path-component spaces

OpenAIRE

Banakh, Taras; Brazas, Jeremy

2018-01-01

The path component space of a topological space $X$ is the quotient space $\\pi_0(X)$ whose points are the path components of $X$. We show that every Tychonoff space $X$ is the path-component space of a Tychonoff space $Y$ of weight $w(Y)=w(X)$ such that the natural quotient map $Y\\to \\pi_0(Y)=X$ is a perfect map. Hence, many topological properties of $X$ transfer to $Y$. We apply this result to construct a compact space $X\\subset \\mathbb{R}^3$ for which the fundamental group $\\pi_1(X,x_0)$ is...

Compactness of the automorphism group of a topological parallelism on real projective 3-space: The disconnected case

OpenAIRE

Rainer, Löwen

2017-01-01

We prove that the automorphism group of a topological parallelism on real projective 3-space is compact. In a preceding article it was proved that at least the connected component of the identity is compact. The present proof does not depend on that earlier result.

The normal holonomy group

International Nuclear Information System (INIS)

Olmos, C.

1990-05-01

The restricted holonomy group of a Riemannian manifold is a compact Lie group and its representation on the tangent space is a product of irreducible representations and a trivial one. Each one of the non-trivial factors is either an orthogonal representation of a connected compact Lie group which acts transitively on the unit sphere or it is the isotropy representation of a single Riemannian symmetric space of rank ≥ 2. We prove that, all these properties are also true for the representation on the normal space of the restricted normal holonomy group of any submanifold of a space of constant curvature. 4 refs

Effects of salinity, P H and temperature on CMC polymer and X C polymer performance

International Nuclear Information System (INIS)

Ghassem Alaskari, M. K.; Nickdel Teymoori, Reza

2007-01-01

The rheological and filtration properties of drilling mud under down-hole conditions may be very different from those measured at ambient pressures and temperatures at the surface. This paper presents the results of an experimental investigation into the temperature and salinity and p H effects on drilling mud rheological and filtration properties. Results are given from tests on water base mud containing CMC polymer and X C polymer. Drilling fluid was investigated at three different temperatures (21.1 d eg C , 48.9 d eg C , 80 d eg C ) containing 8.165 kg/b bl bentonite. The drilling mud salinities in this study were fresh water (Ahwaz water: ppm: 400, Hardness: 120). 2000 ppm, 4000 ppm, 8000 ppm and 40000 ppm. It was found that p H of drilling mud should be kept at range of 8-10, because increasing p H of drilling mud will increase its rheological properties. The salinity and temperature effects show that as the salinity and temperature of drilling mud are increased the effectiveness of polymers in drilling mud will decreased. Moreover, they have a negative effect on filtration properties of drilling mud. In suspensions of sodium montmorillonite that are well dispersed and have low gel strength, both plastic viscosity and yield point decrease with increasing temperature

Pure exciton- and magnon-assisted optical transitionsin the one-dimensional antiferromagnet CsMnCl3x2H2O (CMC)

International Nuclear Information System (INIS)

Jia, W.; Strauss, E.; Yen, W.M.

1981-01-01

We report the first observation of the pure electronic transitions in the 4 T 1 state of Mn 2+ ions in the one-dimensional antiferromagnet CsMnCl 3 x2H 2 O (CMC) in the absorption, excitation, and fluorescence spectra. Selection rules are analyzed: the exciton transition is electric dipole allowed, the magnon sideband in emission is a single-ion process, and is both electric and magnetic dipole allowed; however, the magnon sideband in absorption is an ion-pair process and is a weakened-electric-dipole and magnetic-dipole transition. The density of magnon states and the line profile of the magnon sideband have been calculated. The results explain the peculiar line shapes of the observed sideband emission. An exponential decay of the exciton is observed with a lifetime of 0.576 ms

Fiscal 1999 technical survey report. Green Helmet Project (China, Steel industry - Coal moisture control facilities); 1999 nendo green helmet jigyo (Chugoku seitetsugyo) sekitan choshitsu setsubi chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

For the purpose of meeting the needs of Chinese steelmaking corporations disclosed at an energy conservation diagnosing session of a Japan-China steelmaking energy conservation seminar held in July 1999, Japanese specialists were sent to Chinese steelmaking plants, namely, Benxi Iron and Steel (Group) Complex, Wuhan Iron and Steel (Group) Company, and Nanjing Iron and Steel Works. They described the CMC (coal moisture control) technique for its popularization and for effectively utilizing the same for coke ovens. Also, feasibility studies were conducted for CMC installation at the respective plants. Engineers were invited from the Chinese plants to Japan for the observation of associated facilities and for the exchange of opinions. As the result, leading members of the Chinese steelmaking plants now learned the usefulness of CMC. In the feasibility studies, CMC installation led to a reduction in dry distillation energy, that is, a reduction in the amount of fuel gas required, to an improvement on coke production, and to the selection of the fluidized bed dryer as the optimum system. At Chungching Iron and Steel Works, the existing CMC facilities were not in continuous operation because of an inclined conveyer failure, yet there was a strong will to utilize the CMC technique. (NEDO)

Unitary Representations of Gauge Groups

Science.gov (United States)

Huerfano, Ruth Stella

I generalize to the case of gauge groups over non-trivial principal bundles representations that I. M. Gelfand, M. I. Graev and A. M. Versik constructed for current groups. The gauge group of the principal G-bundle P over M, (G a Lie group with an euclidean structure, M a compact, connected and oriented manifold), as the smooth sections of the associated group bundle is presented and studied in chapter I. Chapter II describes the symmetric algebra associated to a Hilbert space, its Hilbert structure, a convenient exponential and a total set that later play a key role in the construction of the representation. Chapter III is concerned with the calculus needed to make the space of Lie algebra valued 1-forms a Gaussian L^2-space. This is accomplished by studying general projective systems of finitely measurable spaces and the corresponding systems of sigma -additive measures, all of these leading to the description of a promeasure, a concept modeled after Bourbaki and classical measure theory. In the case of a locally convex vector space E, the corresponding Fourier transform, family of characters and the existence of a promeasure for every quadratic form on E^' are established, so the Gaussian L^2-space associated to a real Hilbert space is constructed. Chapter III finishes by exhibiting the explicit Hilbert space isomorphism between the Gaussian L ^2-space associated to a real Hilbert space and the complexification of its symmetric algebra. In chapter IV taking as a Hilbert space H the L^2-space of the Lie algebra valued 1-forms on P, the gauge group acts on the motion group of H defining in an straight forward fashion the representation desired.

Facile synthesis and characterization of novel biodegradable amphiphilic block copolymers bearing pendant hydroxyl groups

Energy Technology Data Exchange (ETDEWEB)

Hu, Gaicen; Fan, Xiaoshan; Xu, Bingcan; Zhang, Delong; Hu, Zhiguo, E-mail: zghu@htu.cn

2014-10-01

Novel amphiphilic block copolymers bearing pendant hydroxyl groups polylactide-b–poly(3,3-bis(Hydroxymethyl–triazolylmethyl) oxetane)-b–polylactide (PLA-b–PHMTYO-b–PLA) were synthesized via a facile and efficient method. First, the block copolymer intermediates polylactide-b–poly(3,3-Diazidomethyloxetane)-b–polylactide (PLA-b–PBAMO-b–PLA) were synthesized through ring-opening polymerization of lactide using PBAMO as a macroinitiator. Following “Click” reaction of PLA-b–PBAMO-b–PLA with propargyl alcohol provided the targeted amphiphilic block copolymers PLA-b–PHMTYO-b–PLA with pendant hydroxyl groups. The composition and structure of prepared copolymers were characterized by {sup 1}H nuclear magnetic resonance ({sup 1}H NMR) spectroscopy, Fourier transform infrared (FT-IR) and gel permeation chromatography (GPC). The self-assembly behavior of the copolymers in water was investigated by transmission electron microscope (TEM), dynamic light scattering (DLS) and static light scattering (SLS). The results showed that the novel copolymers PLA-b–PHMTYO-b–PLA self-assembled into spherical micelles with diameters ranging from 100 nm to 200 nm in aqueous solution. These copolymers also exhibited low critical micellar concentrations (CMC: 6.9 × 10{sup −4} mg/mL and 3.9 × 10{sup −5} mg/mL, respectively). In addition, the in vitro cytotoxicity of these copolymers was determined in the presence of L929 cells. The results showed that the block copolymers PLA-b–PHMTYO-b–PLA exhibited better biocompatibility. Therefore, these well-defined copolymers are expected to find some applications in drug delivery or tissue engineering. - Highlights: • The method to synthesize PLA-b–PHMTYO-b–PLA is relatively facile and efficient. • PLA-b–PHMTYO-b–PLA self-assembles into spherical micelles with low CMC in water. • PLA-b–PHMTYO-b–PLA exhibits better biocompatibility and biodegradability.

Facile synthesis and characterization of novel biodegradable amphiphilic block copolymers bearing pendant hydroxyl groups

International Nuclear Information System (INIS)

Hu, Gaicen; Fan, Xiaoshan; Xu, Bingcan; Zhang, Delong; Hu, Zhiguo

2014-01-01

Novel amphiphilic block copolymers bearing pendant hydroxyl groups polylactide-b–poly(3,3-bis(Hydroxymethyl–triazolylmethyl) oxetane)-b–polylactide (PLA-b–PHMTYO-b–PLA) were synthesized via a facile and efficient method. First, the block copolymer intermediates polylactide-b–poly(3,3-Diazidomethyloxetane)-b–polylactide (PLA-b–PBAMO-b–PLA) were synthesized through ring-opening polymerization of lactide using PBAMO as a macroinitiator. Following “Click” reaction of PLA-b–PBAMO-b–PLA with propargyl alcohol provided the targeted amphiphilic block copolymers PLA-b–PHMTYO-b–PLA with pendant hydroxyl groups. The composition and structure of prepared copolymers were characterized by 1 H nuclear magnetic resonance ( 1 H NMR) spectroscopy, Fourier transform infrared (FT-IR) and gel permeation chromatography (GPC). The self-assembly behavior of the copolymers in water was investigated by transmission electron microscope (TEM), dynamic light scattering (DLS) and static light scattering (SLS). The results showed that the novel copolymers PLA-b–PHMTYO-b–PLA self-assembled into spherical micelles with diameters ranging from 100 nm to 200 nm in aqueous solution. These copolymers also exhibited low critical micellar concentrations (CMC: 6.9 × 10 −4 mg/mL and 3.9 × 10 −5 mg/mL, respectively). In addition, the in vitro cytotoxicity of these copolymers was determined in the presence of L929 cells. The results showed that the block copolymers PLA-b–PHMTYO-b–PLA exhibited better biocompatibility. Therefore, these well-defined copolymers are expected to find some applications in drug delivery or tissue engineering. - Highlights: • The method to synthesize PLA-b–PHMTYO-b–PLA is relatively facile and efficient. • PLA-b–PHMTYO-b–PLA self-assembles into spherical micelles with low CMC in water. • PLA-b–PHMTYO-b–PLA exhibits better biocompatibility and biodegradability

Group dynamics in a long-term blind endeavor on Earth: An analog for space missions (Lewis & Clark Expedition group dynamic analysis)

Science.gov (United States)

Allner, M.; Rygalov, V.

2008-12-01

suggested distinguishable mission phase model, the Lewis and Clark Expedition will be analyzed for similarities to these space findings. Factors of consideration in support of this analysis involve an understanding of the leadership qualities of Lewis and Clark (and relations established and maintained with one another), the selection and diversity of their crew, and the group dynamics that were developed and maintained so carefully during the expedition. With this knowledge and understanding one can gain enormous insights useful in the planning and preparation for future long-duration space exploratory missions with high level of autonomy, mobility, minimal primary life support supply and high dependence on material re-circulation and In-Situ Resource Utilization approach.

The fundamental groupoid of the quotient of a Hausdorff space by a discontinuous action of a discrete group is the orbit groupoid of the induced action

OpenAIRE

Brown, Ronald; Higgins, Philip J.

2002-01-01

The main result is that the fundamental groupoid of the orbit space of a discontinuous action of a discrete group on a Hausdorff space which admits a universal cover is the orbit groupoid of the fundamental groupoid of the space. We also describe work of Higgins and of Taylor which makes this result usable for calculations. As an example, we compute the fundamental group of the symmetric square of a space. The main result, which is related to work of Armstrong, is due to Brown and Higgins in ...

Quantum groups, roots of unity and particles on quantized Anti-de Sitter space

International Nuclear Information System (INIS)

Steinacker, H.

1997-01-01

Quantum groups in general and the quantum Anti-de Sitter group U q (so(2,3)) in particular are studied from the point of view of quantum field theory. The author shows that if q is a suitable root of unity, there exist finite-dimensional, unitary representations corresponding to essentially all the classical one-particle representations with (half) integer spin, with the same structure at low energies as in the classical case. In the massless case for spin ≥ 1, open-quotes naiveclose quotes representations are unitarizable only after factoring out a subspace of open-quotes pure gaugesclose quotes, as classically. Unitary many-particle representations are defined, with the correct classical limit. Furthermore, the author identifies a remarkable element Q in the center of U q (g), which plays the role of a BRST operator in the case of U q (so(2,3)) at roots of unity, for any spin ≥ 1. The associated ghosts are an intrinsic part of the indecomposable representations. The author shows how to define an involution on algebras of creation and anihilation operators at roots of unity, in an example corresponding to non-identical particles. It is shown how nonabelian gauge fields appear naturally in this framework, without having to define connections on fiber bundles. Integration on Quantum Euclidean space and sphere and on Anti-de Sitter space is studied as well. The author gives a conjecture how Q can be used in general to analyze the structure of indecomposable representations, and to define a new, completely reducible associative (tensor) product of representations at roots of unity, which generalizes the standard open-quotes truncatedclose quotes tensor product as well as many-particle representations

Quantum groups, roots of unity and particles on quantized Anti-de Sitter space

Energy Technology Data Exchange (ETDEWEB)

Steinacker, Harold [Univ. of California, Berkeley, CA (United States). Dept. of Physics

1997-05-23

Quantum groups in general and the quantum Anti-de Sitter group U_q(so(2,3)) in particular are studied from the point of view of quantum field theory. The author shows that if q is a suitable root of unity, there exist finite-dimensional, unitary representations corresponding to essentially all the classical one-particle representations with (half) integer spin, with the same structure at low energies as in the classical case. In the massless case for spin ≥ 1, "naive" representations are unitarizable only after factoring out a subspace of "pure gauges", as classically. Unitary many-particle representations are defined, with the correct classical limit. Furthermore, the author identifies a remarkable element Q in the center of U_q(g), which plays the role of a BRST operator in the case of U_q(so(2,3)) at roots of unity, for any spin ≥ 1. The associated ghosts are an intrinsic part of the indecomposable representations. The author shows how to define an involution on algebras of creation and anihilation operators at roots of unity, in an example corresponding to non-identical particles. It is shown how nonabelian gauge fields appear naturally in this framework, without having to define connections on fiber bundles. Integration on Quantum Euclidean space and sphere and on Anti-de Sitter space is studied as well. The author gives a conjecture how Q can be used in general to analyze the structure of indecomposable representations, and to define a new, completely reducible associative (tensor) product of representations at roots of unity, which generalizes the standard "truncated" tensor product as well as many-particle representations.

Safety and Efficacy of Alginate Adhesion Barrier Gel in Compromised Intestinal Anastomosis.

Science.gov (United States)

Chaturvedi, Ankit A; Yauw, Simon T K; Lomme, Roger M L M; Hendriks, Thijs; van Goor, Harry

For any anti-adhesive barrier developed for abdominal surgery, the use under conditions in which anastomotic healing is compromised needs to be investigated. The current study evaluates the effect of a new ultrapure alginate gel on early healing of high-risk anastomoses in the ileum and compares this with the gold standard used in clinical practice. In 75 adult male Wistar rats, a 5 mm ileal segment was resected and continuity was restored by construction of an inverted anastomosis. Rats were divided randomly into a control group and groups receiving either alginate gel or a sodium hyaluronate carboxymethylcellulose (HA/CMC) film around the anastomosis (n = 25 each). Carprofen, given in a daily dose of 1.25 mg/kg, was used to compromise anastomotic healing. At day three, animals were killed and scored for signs of anastomotic leakage and the presence of adhesions. The incidence of adhesion formation was 95% in the HA/CMC film group, which was significantly higher than in the controls (64%, p = 0.010) and the alginate gel group (52%, p = 0.004). The adhesion score was nearly 40% lower in the alginate gel group compared with the HA/CMC film group. The incidence of ileal leakage in the HA/CMC film group (92%) was significantly higher than in the controls (68%, p = 0.016). Leakage rate did not differ between the alginate gel and control groups. There was no significant difference between groups in either incision bursting pressure or incision breaking strength. Ultrapure alginate gel does not interfere with repair of ileal anastomoses constructed under conditions in which chances of anastomotic dehiscence are high. The alginate gel performs better than the HA/CMC film.

"Friends" and "Foes" in the Social Space of the Tatar Ethnic Group

Directory of Open Access Journals (Sweden)

Nataliia O. Khazieva

2017-10-01

Full Text Available The history of the World Culture is a demonstration of the "war" between the two opposites: on the one hand, we see a trend towards unification of all aspects of life on a global scale, and on the other, there is a clear confrontation between different groups of mankind. Of the many causes of the disunity of the people, the authors' focus at the opposition "friend – foe" as a metaphysical principle of formation of social space wasn't chosen by accident. The fact is that any culture, in principle, is dichotomous, and the opposition "friend – foe" is the fullest incarnation of this dichotomy. As a universal principle of the formation and functioning of the cultures, it originally manifests itself in every one of them. And, as the authors of the study suggest: this opposition could either "work" in general on the cross-cultural cooperation and unity or be one of the confrontation sources. The main result of the study is that history has prepared and put forward the Tartars for carrying out a special mission, to unite peoples and cultures. But the revolutionary social upheavals that take place in the modern world pose a threat (in the circumstances of forced migration of peoples, the growth of national consciousness of the former Soviet Union space, and especially in the face of Islamic fundamentalism on fulfilling this function.

Trolling in asynchronous computer-mediated communication:\\ud From user discussions to academic definitions

OpenAIRE

Hardaker, Claire

2010-01-01

Whilst computer-mediated communication (CMC) can benefit users by providing quick and easy communication between those separated by time and space, it can also provide varying degrees of anonymity that may encourage a sense of impunity and freedom from being held accountable for\\ud inappropriate online behaviour. As such, CMC is a fertile ground for studying impoliteness, whether it occurs in response to perceived threat (flaming), or as an end in its own right (trolling). Currently, first an...

“I refuse to respond to this obvious troll" : an overview of responses to (perceived) trolling

OpenAIRE

Hardaker, Claire

2015-01-01

Computer-mediated communication (CMC) provides many benefits, including quick, efficient communication over time and space. At the same time, however, the anonymity it offers can give a sense of impunity, an illusion that behaviour is less hurtful than it really is, and a suppression of empathy. In short, CMC can be a fertile ground for conflict, and one particular manifestation of this is trolling. Trolling involves deliberately attacking others online, typically for amusement's sake. In som...

Evaluating Critical Thinking in Computer Mediated Communication Discussions

Directory of Open Access Journals (Sweden)

Faizah Mohamad

2008-06-01

Full Text Available This paper presents an investigation of whether computer mediated communication (CMC can develop critical thinking in language classrooms. The research was conducted at a university branch campus in Malaysia over a period of 12 weeks. It involved three groups of learners in which each group was exposed to different discussion modes. The first group was exposed to a CMC discussion mode, the second group was exposed to a mixed mode of CMC and face-to-face (F2F discussions and the third group had only the face-to-face mode of discussion. The critical thinking development in these three conditions was evaluated based on the content analysis method used by Newman, Johnson, Cochrane and Webb (1995. This research reports the findings which hopefully will give some insight to other teaching practitioners who are interested in incorporating IT in their classrooms

Ulnar digits contribution to grip strength in patients with thumb carpometacarpal osteoarthritis is less than in normal controls.

Science.gov (United States)

Villafañe, Jorge H; Valdes, Kristin; Angulo-Diaz-Parreño, Santiago; Pillastrini, Paolo; Negrini, Stefano

2015-06-01

Grip testing is commonly used as an objective measure of strength in the hand and upper extremity and is frequently used clinically as a proxy measure of function. Increasing knowledge of hand biomechanics, muscle strength, and prehension patterns can provide us with a better understanding of the functional capabilities of the hand. The objectives of this study were to determine the contribution of ulnar digits to overall grip strength in individuals with thumb carpometacarpal (CMC) osteoarthritis (OA). Thirty-seven subjects participated in the study. This group consisted of 19 patients with CMC OA (aged 60-88 years) and 18 healthy subjects (60-88 years). Three hand configurations were used by the subjects during grip testing: use of the entire hand (index, middle, ring, and little fingers) (IMRL); use of the index, middle, and ring fingers (IMR); and use of only the index and middle fingers (IM). Grip strength findings for the two groups found that compared to their healthy counterparts, CMC OA patients had, on average, a strength deficiency of 45.6, 35.5, and 28.8 % in IMRL, IMR, and IM, respectively. The small finger contribution to grip is 14.3 % and the ring and small finger contribute 34 % in subjects with CMC OA. Grip strength decreases as the number of digits contributing decreased in both groups. The ulnar digits contribution to grip strength is greater than one third of total grip strength in subjects with CMC OA. Individuals with CMC OA demonstrate significantly decreased grip strength when compared to their healthy counterparts.

Kent in space: Cosmic dust to space debris

Science.gov (United States)

McDonnell, J. A. M.

1994-10-01

The dusty heritage of the University of Kent's Space Group commenced at Jodrell Bank, Cheshire, U.K., the home of the largest steerable radio telescope. While Professor Bernard Lovell's 250 ft. diameter telescope was used to command the U.S. deep space Pioneer spacecraft, Professor Tony McDonnell, as a research student in 1960, was developing a space dust detector for the US-UK Ariel program. It was successful. With a Ph.D. safely under the belt, it seemed an inevitable step to go for the next higher degree, a B.T.A.] Two years with NASA at Goddard Space Flight Center, Greenbelt, provided excellent qualifications for such a graduation ('Been to America'). A spirited return to the University of Kent at Canterbury followed, to one of the green field UK University sites springing from the Robbins Report on Higher Education. Swimming against the current of the brain drain, and taking a very considerable reduction in salary, it was with some disappointment that he found that the UK Premier Harold Wilson's 'white-hot technological revolution' never quite seemed to materialize in terms of research funding] Research expertise, centered initially on cosmic dust, enlarged to encompass planetology during the Apollo program, and rightly acquired international acclaim, notching up a history of space missions over 25 years. The group now comprises 38 people supported by four sources: the government's Research Councils, the University, the Space Agencies and Industry. This paper describes the thrust of the group's Research Plan in Space Science and Planetology; not so much based on existing international space missions, but more helping to shape the direction and selection of space missions ahead.

Plasticity of premotor cortico-muscular coherence in severely impaired stroke patients with hand paralysis

Directory of Open Access Journals (Sweden)

Paolo Belardinelli

2017-01-01

In conclusion, functionally relevant modulations of CMC can be detected in patients with long-term, severe motor deficits after a brain-robot assisted rehabilitation training. Premotor beta-band CMC may serve as a biomarker and therapeutic target for novel treatment approaches in this patient group.

Invariant subspaces in some function spaces on symmetric spaces. II

International Nuclear Information System (INIS)

Platonov, S S

1998-01-01

Let G be a semisimple connected Lie group with finite centre, K a maximal compact subgroup of G, and M=G/K a Riemannian symmetric space of non-compact type. We study the problem of describing the structure of closed linear subspaces in various function spaces on M that are invariant under the quasiregular representation of the group G. We consider the case when M is a symplectic symmetric space of rank 1

Managing the space sciences

Science.gov (United States)

1995-01-01

In April 1994 the National Research Council received a request from NASA that the NRC's Space Studies Board provide guidance on questions relating to the management of NASA's programs in the space sciences. The issues raised in the request closely reflect questions posed in the agency's fiscal year 1994 Senate appropriations report. These questions included the following: Should all the NASA space science programs be gathered into a 'National Institute for Space Science'? What other organizational changes might be made to improve the coordination and oversight of NASA space science programs? What processes should be used for establishing interdisciplinary science priorities based on scientific merit and other criteria, while ensuring opportunities for newer fields and disciplines to emerge? And what steps could be taken to improve utilization of advanced technologies in future space scienc missions? This report details the findings of the Committee on the Future of Space Science (FOSS) and its three task groups: the Task Group on Alternative Organizations, Task Group on Research Prioritization, and the Task Group on Technology.

Does occupational therapy reduce the need for surgery in carpometacarpal osteoarthritis? Protocol for a randomized controlled trial.

Science.gov (United States)

Kjeken, Ingvild; Eide, Ruth Else Mehl; Klokkeide, Åse; Matre, Karin Hoegh; Olsen, Monika; Mowinckel, Petter; Andreassen, Øyvor; Darre, Siri; Nossum, Randi

2016-11-15

In the absence of disease-modifying interventions for hand osteoarthritis (OA), occupational therapy (OT) comprising patient education, hand exercises, assistive devices and orthoses are considered as core treatments, whereas surgery are recommended for those with severe carpometacarpal (CMC1) OA. However, even though CMC1 surgery may reduce pain and improve function, the risk of adverse effects is high, and randomized controlled trials comparing surgery with non-surgical interventions are warranted. This multicentre randomized controlled trial aims to address the following questions: Does OT in the period before surgical consultation reduce the need for surgery in CMC1-OA? What are patients' motivation and reasons for wanting CMC1-surgery? Are there differences between departments of rheumatology concerning the degree of CMC1-OA, pain and functional limitations in patients who are referred for surgical consultation for CMC1 surgery? Is the Measure of Activity Performance of the Hand a reliable measure in patients with CMC1-OA? Do patients with CMC1-OA with and without affection of the distal and proximal interphalangeal finger joints differ with regard to symptoms and function? Do the degree of CMC1-OA, symptoms and functional limitations significantly predict improvement after 2 years following OT or CMC1-surgery? Is OT more cost-effective than surgery in the management of CMC1-OA? All persons referred for surgical consultation due to their CMC1-OA at one of three Norwegian departments of rheumatology are invited to participate. Those who agree attend a clinical assessment and report their symptoms, function and motivation for surgery in validated outcome measures, before they are randomly selected to receive OT in the period before surgical consultation (estimated n = 180). The primary outcome will be the number of participants in each group who have received surgical treatment after 2 years. Secondary and tertiary outcomes are pain, function and

Suicide attempt with a mix of synthetic cannabinoids and synthetic cathinones: Case report of non-fatal intoxication with AB-CHMINACA, AB-FUBINACA, alpha-PHP, alpha-PVP and 4-CMC.

Science.gov (United States)

Klavž, Janez; Gorenjak, Maksimiljan; Marinšek, Martin

2016-08-01

We report on a case of intoxication with a mix of new psychoactive substances. A 38-year-old male was brought to the emergency department (ED) following the ingestion of an unknown drug in a suicide attempt. During the transport, he became progressively more somnolent and unresponsive to painful stimuli. Urine and stomach content were collected on admission to be screened for drugs of abuse and medicinal drugs. After admission, the patient's next of kin presented five small grip seal plastic bags containing different powders/crystals, and they were sent for analysis along with urine and stomach content to the toxicology laboratory. An easy and rapid sample preparation technique was applied for the extraction of urine and stomach content. Samples were extracted with liquid-liquid extraction (LLE) technique and analysed using gas chromatography-mass spectrometry (GC-MS). A small amount of powder material from the bags was diluted in methanol and injected directly into the GC-MS instrument. Obtained spectra (EI) were evaluated against SWGDRUG library. Five different designer drugs were identified in the powder material, including synthetic cannabinoids (AB-CHMINACA, AB-FUBINACA) and synthetic cathinones (alpha-PHP, alpha-PVP and 4-CMC). With the exception of 4-CMC, all of these substances were also detected in the stomach content along with the prescription drugs. This is the first time that a positive identification of these five drugs has been made by a clinical laboratory in Slovenia. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Novel 3D C-SiC Composites for Hot Structures, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Future NASA hypersonic vehicles offer a potential to incorporate advanced ceramic matrix composites (CMC). The key characteristics include excellent mechanical...

Space Vector Modulation Technique to Reduce Leakage Current of a Transformerless Three-Phase Four-Leg Photovoltaic System

Directory of Open Access Journals (Sweden)

F. Hasanzad

2017-06-01

Full Text Available Photovoltaic systems integrated to the grid have received considerable attention around the world. They can be connected to the electrical grid via galvanic isolation (transformer or without it (transformerless. Despite making galvanic isolation, low frequency transformer increases size, cost and losses. On the other hand, transformerless PV systems increase the leakage current (common-mode current, (CMC through the parasitic capacitors of the PV array. Inverter topology and switching technique are the most important parameters the leakage current depends on. As there is no need to extra hardware for switching scheme modification, it's an economical method for reducing leakage current. This paper evaluates the effect of different space vector modulation techniques on leakage current for a two-level three-phase four-leg inverter used in PV system. It proposes an efficient space vector modulation method which decreases the leakage current to below the quantity specified in VDE-0126-1-1 standard. furthermore, some other characteristics of the space vector modulation schemes that have not been significantly discussed for four-leg inverter, are considered, such as, modulation index, switching actions per period, common-mode voltage (CMV, and total harmonic distortion (THD. An extend software simulation using MATLAB/Simulink is performed to verify the effectiveness of the modulation technique.

Group Dynamics as a Critical Component of Successful Space Exploration: Conceptual Theory and Insights from the Biosphere 2 Closure Experiment

Science.gov (United States)

Nelson, Mark; Allen, John P.

As space exploration and eventually habitation achieves longer durations, successfully managing group dynamics of small, physically isolated groups will become vital. The paper summarizes important underlying research and conceptual theory and how these manifested in a well-documented example: the closure experiments of Biosphere 2. Key research breakthroughs in discerning the operation of small human groups comes from the pioneering work of W.R. Bion. He discovered two competing modalities of behavior. The first is the “task-oriented” or work group governed by shared acceptance of goals, reality-thinking in relation to time, resources and rational, and intelligent management of challenges presented. The opposing, usually unconscious, modality is what Bion called the “basic-assumption” group and alternates between three “group animal” groups: dependency/kill the leader; fight/flight and pairing. If not dealt with, these dynamics work to undermine and defeat the conscious task group’s goal achievement. The paper discusses crew training and selection, various approaches to structuring the work and hierarchy of the group, the importance of contact with a larger population through electronic communication and dealing with the “us-them” syndrome frequently observed between crew and Mission Control. The experience of the first two year closure of Biosphere 2 is drawn on in new ways to illustrate vicissitudes and management of group dynamics especially as both the inside team of biospherians and key members of Mission Control had training in working with group dynamics. Insights from that experience may help mission planning so that future groups in space cope successfully with inherent group dynamics challenges that arise.

The group approach to AdS space propagators

International Nuclear Information System (INIS)

Leonhardt, Thorsten; Manvelyan, Ruben; Ruehl, Werner

2003-01-01

We show that AdS two-point functions can be obtained by connecting two points in the interior of AdS space with one point on its boundary by a dual pair of Dobrev's boundary-to-bulk intertwiners and integrating over the boundary point

Between-group behaviour in health care: gaps, edges, boundaries, disconnections, weak ties, spaces and holes. A systematic review

Directory of Open Access Journals (Sweden)

Braithwaite Jeffrey

2010-12-01

Full Text Available Abstract Background Gaps are typically regarded as a problem to be solved. People are stimulated to close or plug them. Researchers are moved to fill deficits in the literature in order to realise a more complete knowledge base, health authorities want to bridge policy-practice disconnections, managers to secure resources to remedy shortfalls between poor and idealised care, and clinicians to provide services to patients across the divides of organisational silos. Despite practical and policy work in many health systems to bridge gaps, it is valuable to study research examining them for the insights provided. Structural holes, spaces between social clusters and weak or absent ties represent fissures in networks, located in less densely populated parts of otherwise closely connected social structures. Such gaps are useful as they illustrate how communication potentially breaks down or interactivity fails. This paper discusses empirical and theoretical work on this phenomenon with the aim of analysing a specific exemplar, the structures of silos within health care organisations. Methods The research literature on social spaces, holes, gaps, boundaries and edges was searched systematically, and separated into health [n = 13] and non-health [n = 55] samples. The health literature was reviewed and synthesised in order to understand the circumstances between stakeholders and stakeholder groups that both provide threats to networked interactions and opportunities to strengthen the fabric of organisational and institutional inter-relationships. Results The research examples illuminate various network structure characteristics and group interactions. They explicate a range of opportunities for improved social and professional relations that understanding structural holes, social spaces and absent ties affords. A principal finding is that these kinds of gaps illustrate the conditions under which connections are strained or have been severed, where the

Quantum isometry groups

Indian Academy of Sciences (India)

Jyotishman Bhowmick

2015-11-07

Nov 7, 2015 ... Classical. Quantum. Background. Compact Hausdorff space. Unital C∗ algebra. Gelfand-Naimark. Compact Group. Compact Quantum Group. Woronowicz. Group Action. Coaction. Woronowicz. Riemannian manifold. Spectral triple. Connes. Isometry group. Quantum Isometry Group. To be discussed.

The extensions of space-time. Physics in the 8-dimensional homogeneous space D = SU(2,2)/K

International Nuclear Information System (INIS)

Barut, A.O.

1993-07-01

The Minkowski space-time is only a boundary of a bigger homogeneous space of the conformal group. The conformal group is the symmetry group of our most fundamental massless wave equations. These extended groups and spaces have many remarkable properties and physical implications. (author). 36 refs

Contribution of on-site Coulomb repulsion energy to structural, electronic and magnetic properties of SrCoO3 for different space groups: first-principles study

Directory of Open Access Journals (Sweden)

Muhammady Shibghatullah

2018-03-01

Full Text Available We report structural, electronic, and magnetic properties of SrCoO3 in Pm3̅m and P4/mbm space groups, which are calculated by using generalized gradient approximation corrected with on-site Coulomb repulsion U and exchange energies J. The cubic lattice parameter a and local magnetic moments of Co (μCo are optimized by varying U at Co 3d site. Employing ultrasoft pseudopotential, the values of U = 8 eV and J = 0.75 eV are the best choice for Pm3̅m space group. We found the value of μCo = 2.56 μB, which is consistent with the previous results. It was also found that Co 3d, hybridized with O 2p, is the main contributor to ferromagnetic metallic properties. Besides, norm-conserving pseudopotential promotes a, which is in good agreement with experimental result. However, it is not suitable for P4/mbm space group. By using ultrasoft pseudopotential, the value of U = 3 eV (J = 0.75 is the most suitable for P4/mbm group. Ferromagnetic metallic properties, Jahn-Teller distortion, and reasonable lattice parameters have been obtained. This study shows that U has significant contribution to the calculated properties and also points out that P4/mbm space group with US-PP is suitable to describe experimental results.

Symmetry and group theory in chemistry

CERN Document Server

Ladd, M

1998-01-01

A comprehensive discussion of group theory in the context of molecular and crystal symmetry, this book covers both point-group and space-group symmetries.Provides a comprehensive discussion of group theory in the context of molecular and crystal symmetryCovers both point-group and space-group symmetriesIncludes tutorial solutions

Elementary particles in curved spaces

International Nuclear Information System (INIS)

Lazanu, I.

2004-01-01

The theories in particle physics are developed currently, in Minkowski space-time starting from the Poincare group. A physical theory in flat space can be seen as the limit of a more general physical theory in a curved space. At the present time, a theory of particles in curved space does not exist, and thus the only possibility is to extend the existent theories in these spaces. A formidable obstacle to the extension of physical models is the absence of groups of motion in more general Riemann spaces. A space of constant curvature has a group of motion that, although differs from that of a flat space, has the same number of parameters and could permit some generalisations. In this contribution we try to investigate some physical implications of the presumable existence of elementary particles in curved space. In de Sitter space (dS) the invariant rest mass is a combination of the Poincare rest mass and the generalised angular momentum of a particle and it permits to establish a correlation with the vacuum energy and with the cosmological constant. The consequences are significant because in an experiment the local structure of space-time departs from the Minkowski space and becomes a dS or AdS space-time. Discrete symmetry characteristics of the dS/AdS group suggest some arguments for the possible existence of the 'mirror matter'. (author)

Geometric modular action and transformation groups

International Nuclear Information System (INIS)

Summers, S.J.

1996-01-01

We study a weak form of geometric modular action, which is naturally associated with transformation groups of partially ordered sets and which provides these groups with projective representations. Under suitable conditions it is shown that these groups are implemented by point transformations of topological spaces serving as models for space-times, leading to groups which may be interpreted as symmetry groups of the space-times. As concrete examples, it is shown that the Poincare group and the de Sitter group can be derived from this condition of geometric modular action. Further consequences and examples are discussed. (orig.)

Fisher's Zeros as the Boundary of Renormalization Group Flows in Complex Coupling Spaces

International Nuclear Information System (INIS)

Denbleyker, A.; Du Daping; Liu Yuzhi; Meurice, Y.; Zou Haiyuan

2010-01-01

We propose new methods to extend the renormalization group transformation to complex coupling spaces. We argue that Fisher's zeros are located at the boundary of the complex basin of attraction of infrared fixed points. We support this picture with numerical calculations at finite volume for two-dimensional O(N) models in the large-N limit and the hierarchical Ising model. We present numerical evidence that, as the volume increases, the Fisher's zeros of four-dimensional pure gauge SU(2) lattice gauge theory with a Wilson action stabilize at a distance larger than 0.15 from the real axis in the complex β=4/g 2 plane. We discuss the implications for proofs of confinement and searches for nontrivial infrared fixed points in models beyond the standard model.

Protein crystal growth studies at the Center for Macromolecular Crystallography

International Nuclear Information System (INIS)

DeLucas, Lawrence J.; Long, Marianna M.; Moore, Karen M.; Harrington, Michael; McDonald, William T.; Smith, Craig D.; Bray, Terry; Lewis, Johanna; Crysel, William B.; Weise, Lance D.

2000-01-01

The Center for Macromolecular Crystallography (CMC) has been involved in fundamental studies of protein crystal growth (PCG) in microgravity and in our earth-based laboratories. A large group of co-investigators from academia and industry participated in these experiments by providing protein samples and by performing the x-ray crystallographic analysis. These studies have clearly demonstrated the usefulness of a microgravity environment for enhancing the quality and size of protein crystals. Review of the vapor diffusion (VDA) PCG results from nineteen space shuttle missions is given in this paper

Novel biocomposite of carboxymethyl chitosan and pineapple peel carboxymethylcellulose as sunscreen carrier.

Science.gov (United States)

Wongkom, Lucksanee; Jimtaisong, Ampa

2017-02-01

This study aims to prepare of biocomposite of carboxymethyl chitosan (CM-chitosan) and carboxymethylcellulose (CMC) from Ananas comosus (pineapple) peel for use as broad spectrum sunscreen carrier. Biocomposite was produced by using ferulic acid (FA), a plant extract, as crosslinker with the optimal ratio of CMC: CM-chitosan: FA at 1:2:4%w. FT-IR technique demonstrated that crosslinking may occur at amine group of CM-chitosan and carboxyl group of FA and hydrogen bonding between hydroxyl group of CMC and carboxyl group of FA. Biocomposite is pale yellow powder and present fibre bundle-like surface in the SEM image. DSC, TGA and XRD results indicated that new compound was formed. The particle size of biocomposite is 626nm determined by using Zetasizer. Hydrophilic TiO 2 and phenylbenzimidazole sulphonic acid (PBSA) were used as sunscreen agent at ratio of TiO 2 : PBSA at 2:1%w. The biocomposite sunscreen possesses the SPF value of 2.47 with boost star rating of 3 at 2% compound. The results obtained indicate that the biocomposite was successfully prepared from CM-chitosan and pineapple peel CMC and the system can be used as matrix delivery system for hydrophilic sunscreens. Copyright © 2016 Elsevier B.V. All rights reserved.

Exame do fluido peritoneal e hemograma de eqüinos submetidos à laparotomia e infusão intraperitoneal de carboximetilcelulose Peritoneal fluid exam and hemogram of horses submited to laparotomy and carboxymethylcellulose intraperitoneal infusion

Directory of Open Access Journals (Sweden)

Marco Aurélio Ferreira Lopes

1999-03-01

Full Text Available A aplicação intraperitoneal de carboximetilcelulose (CMC tem sido utilizada na prevenção de aderências peritoneais em animais e em humanos. Os objetivos deste trabalho foram avaliar a resposta do peritônio ao trauma cirúrgico e à aplicação de CMC e estudar como se processa a metabolização da CMC. Dezenove eqüinos mestiços foram submetidos à laparotomia, quando se produziram lesões no jejuno distal por abrasão da serosa e isquemia. Nos 9 eqüinos do grupo tratamento, antes da síntese da parede abdominal, foi instilada, na cavidade peritoneal, uma solução estéril de CMC, a 1% na dose de 7ml/kg. Nos eqüinos do grupo controle, nenhum medicamento foi aplicado na cavidade peritoneal. Após a cirurgia, colheram-se sangue e fluido peritoneal em 9 momentos: 4 horas após o fim da cirurgia, nos 3 primeiros dias pós-operatórios, pela manhã e a cada 48 horas nos dias subseqüentes (no 5º, 7º, 9º, 11º e 13º dias pós-operatórios. Os exames laboratoriais demonstraram que todos os animais desenvolveram inflamação peritoneal. Entretanto, nos animais do grupo tratamento, esta inflamação foi mais intensa e com um curso mais longo. Observou-se também que a excreção da CMC ocorreu por fagocitose.Intraperitoneal application of carboxymethylcellulose (CMC has been used for peritoneal adhesions prevention in animals and humans. The objectives of this research was to study the peritoneal response to surgical trauma and application of CMC and also to study how CMC excretion occurs. Nineteen healthy mixed breed horses were submited to laparotomy to produce lesions in distal jejunum by serosal abrasion and ischemia. In the nine horses of the treatment group, 7ml/kg of a 1% CMC sterile solution were instilated in peritoneal cavity before abdominal wall syntesis. No medication was instiled in peritoneal cavitiy of the control group horses. After surgery, blood and peritoneal fluid were colected in 9 postoperative moments: 4 hours after

Effects of incentives on psychosocial performances in simulated space-dwelling groups

Science.gov (United States)

Hienz, Robert D.; Brady, Joseph V.; Hursh, Steven R.; Gasior, Eric D.; Spence, Kevin R.; Emurian, Henry H.

Prior research with individually isolated 3-person crews in a distributed, interactive, planetary exploration simulation examined the effects of communication constraints and crew configuration changes on crew performance and psychosocial self-report measures. The present report extends these findings to a model of performance maintenance that operationalizes conditions under which disruptive affective responses by crew participants might be anticipated to emerge. Experiments evaluated the effects of changes in incentive conditions on crew performance and self-report measures in simulated space-dwelling groups. Crews participated in a simulated planetary exploration mission that required identification, collection, and analysis of geologic samples. Results showed that crew performance effectiveness was unaffected by either positive or negative incentive conditions, while self-report measures were differentially affected—negative incentive conditions produced pronounced increases in negative self-report ratings and decreases in positive self-report ratings, while positive incentive conditions produced increased positive self-report ratings only. Thus, incentive conditions associated with simulated spaceflight missions can significantly affect psychosocial adaptation without compromising task performance effectiveness in trained and experienced crews.

Space research in the Netherlands 1980

International Nuclear Information System (INIS)

1981-01-01

In 1960, the Royal Netherlands Academy of Arts and Sciences established a committee with the task of coordinating space research in the Netherlands and maintaining the necessary international contacts. This committe, usually called GROC, has instituted four working groups, in which most of the Netherlands space research is concentrated. These groups are: Working Group for Solar and Stellar Space Research, Working Group for Cosmic Rays, Working Group for Photometry and the Working Group for Satellite Geodesy. General information on space research in the Netherlands Anno 1980 is given. Detailed data about the working groups, their work during 1980 and their programmes are presented, together with a survey of their scientific publications. A financial summary is also included. (Auth.)

Robust numerical simulation of porosity evolution in chemical vapor infiltration III: three space dimension

CERN Document Server

Jin Shi

2003-01-01

Chemical vapor infiltration (CVI) process is an important technology to fabricate ceramic matrix composites (CMC's). In this paper, a three-dimension numerical model is presented to describe pore microstructure evolution during the CVI process. We extend the two-dimension model proposed in [S. Jin, X.L. Wang, T.L. Starr, J. Mater. Res. 14 (1999) 3829; S. Jin. X.L. Wang, T.L. Starr, X.F. Chen, J. Comp. Phys. 162 (2000) 467], where the fiber surface is modeled as an evolving interface, to the three space dimension. The 3D method keeps all the virtue of the 2D model: robust numerical capturing of topological changes of the interface such as the merging, and fast detection of the inaccessible pores. For models in the kinetic limit, where the moving speed of the interface is constant, some numerical examples are presented to show that this three-dimension model will effectively track the change of porosity, close-off time, location and shape of all pores.

Pyrene absorption can be a convenient method for probing critical micellar concentration (cmc) and indexing micellar polarity.

Science.gov (United States)

Basu Ray, Gargi; Chakraborty, Indranil; Moulik, Satya P

2006-02-01

The critical micellar concentration (cmc) of both ionic and non-ionic surfactants can be conveniently determined from the measurements of UV absorption of pyrene in surfactant solution. The results on a number of surfactants have agreed with that realized from pyrene fluorescence measurements as well as that obtained following conductometric, tensiometric and calorimetric methods. The absorbance vs [surfactant] profiles for all the major UV spectral peaks of pyrene have been found to be sigmoidal in nature which were analyzed according to Sigmoidal-Boltzmann equation (SBE) to evaluate the cmcs of the studied surfactants. The difference between the initial and the final asymptotes (a(i) and a(f), respectively) of the sigmoidal profile, Delta a = (a(f)-a(i)) and the slope of the sigmoid, S(sig) have been observed to depend on the type of the surfactant. The Delta a has shown a linear correlation with the ratio of the fluorescence intensities of the first and the third vibronic peaks, I1/I3 of pyrene which is considered as a measure of the environmental polarity (herein micellar interior) of the probe (pyrene). Thus, Delta a values have the prospect for use as another index for the estimation of polarity of micellar interior.

Design Concepts for Low Aspect Ratio High Pressure Turbines for High Bypass Ratio Turbofans, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The performance gains and weight reductions from using Ceramic Matrix Composite(CMC) turbine blades in both the High Pressure Turbine(HPT) and Low Pressure...

The Poincare group as the symmetry group of canonical general relativity

International Nuclear Information System (INIS)

Beig, R.; Murchadha, N. o

1986-01-01

This work reconsiders the formulation, due to Regge and Teitelboim, of the phase space approach to General Relativity in the asymptotically flat context, phrasing it in the language of symplectic geometry. The necessary boundary conditions at spatial infinity are spelled out in detail. Precise meaning is given to the statement that, as a result of these boundary conditions, the Poincare group acts as a symmetry group on the phase space of G.R. This situation is compared with the spi-picture of Ashtekar and Hansen, where a larger asymptotic symmetry group is obtained. (Author)

SpaceTech—Postgraduate space education

Science.gov (United States)

de Bruijn, Ferdi J.; Ashford, Edward W.; Larson, Wiley J.

2008-07-01

, Interpersonal Skills, Telecommunications, Earth Observation and Navigation. A group CCP, a major asset of this unique program, is a focused project, aimed at the formation of a credible virtual commercial space-related business. Participants exercise space systems engineering fundamentals as well as marketing and business engineering tools, with the goal of creating a financially viable business opportunity. They then present the result, in the form of an unsolicited proposal to potential investors, as well as a varied group of engineers, managers and executives from the space community. During the CCP, participants learn the ties between mission and system design and the potential return to investors. They develop an instinct for the technical concepts and which of the parameters to adjust to make their newly conceived business more effective and profitable.

Design Concepts for Cooled Ceramic Matrix Composite Turbine Vanes, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The work proposed herein is to demonstrate that the higher temperature capabilities of Ceramic Matrix Composites (CMC) can be fully utilized to reduce emissions and...

Creating space for citizenship: The impact of group structure on validating the voices of people with dementia.

Science.gov (United States)

Wiersma, Elaine C; O'Connor, Deborah L; Loiselle, Lisa; Hickman, Kathy; Heibein, Bill; Hounam, Brenda; Mann, Jim

2016-05-01

Recently, there has been increasing attention given to finding ways to help people diagnosed with dementia 'live well' with their condition. Frequently however, the attention has been placed on the family care partner as the foundation for creating a context that supports the person with dementia to live well. A recent participatory action research (PAR) study highlighted the importance of beginning to challenge some of the assumptions around how best to include family, especially within a context of supporting citizenship. Three advisory groups consisting of 20 people with dementia, 13 care partners, and three service providers, were set up in three locations across Canada to help develop a self-management program for people with dementia. The hubs met monthly for up to two years. One of the topics that emerged as extremely important to consider in the structuring of the program revolved around whether or not these groups should be segregated to include only people with dementia. A thematic analysis of these ongoing discussions coalesced around four inter-related themes: creating safe spaces; maintaining voice and being heard; managing the balancing act; and the importance of solidarity Underpinning these discussions was the fifth theme, recognition that 'one size doesn't fit all'. Overall an important finding was that the presence of family care-partners could have unintended consequences in relation to creating the space for active citizenship to occur in small groups of people with dementia although it could also offer some opportunities. The involvement of care partners in groups with people with dementia is clearly one that is complex without an obvious answer and dependent on a variety of factors to inform a solution, which can and should be questioned and revisited. © The Author(s) 2016.

Factorizable sheaves and quantum groups

CERN Document Server

Bezrukavnikov, Roman; Schechtman, Vadim

1998-01-01

The book is devoted to the geometrical construction of the representations of Lusztig's small quantum groups at roots of unity. These representations are realized as some spaces of vanishing cycles of perverse sheaves over configuration spaces. As an application, the bundles of conformal blocks over the moduli spaces of curves are studied. The book is intended for specialists in group representations and algebraic geometry.

Automorphisms of free groups with boundaries

DEFF Research Database (Denmark)

A. Jensen, Craig; Wahl, Nathalie

2004-01-01

The automorphisms of free groups with boundaries form a family of groups A_{n,k} closely related to mapping class groups, with the standard automorphisms of free groups as A_{n,0} and (essentially) the symmetric automorphisms of free groups as A_{0,k}. We construct a contractible space L_{n,k} on......The automorphisms of free groups with boundaries form a family of groups A_{n,k} closely related to mapping class groups, with the standard automorphisms of free groups as A_{n,0} and (essentially) the symmetric automorphisms of free groups as A_{0,k}. We construct a contractible space L......_{n,k} on which A_{n,k} acts with finite stabilizers and finite quotient space and deduce a range for the virtual cohomological dimension of A_{n,k}. We also give a presentation of the groups and calculate their first homology group....

Quantum symmetries of classical spaces

OpenAIRE

Bhowmick, Jyotishman; Goswami, Debashish; Roy, Subrata Shyam

2009-01-01

We give a general scheme for constructing faithful actions of genuine (noncommutative as $C^*$ algebra) compact quantum groups on classical topological spaces. Using this, we show that: (i) a compact connected classical space can have a faithful action by a genuine compact quantum group, and (ii) there exists a spectral triple on a classical connected compact space for which the quantum group of orientation and volume preserving isometries (in the sense of \\cite{qorient}) is a genuine quantum...

Advanced Display Interface Technology, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — CMC proposes, along with our collaborator, Dr. Mica Endlsey of SA Technologies, to produce a framework from which an Adaptive User Interface (AUI) can be modeled and...

JOPAT [14th Edition - Jan to Dec 2009

African Journals Online (AJOL)

Secretary

against human lung cancer cell lines (5), and antibacterial activity (6). ... Bangladesh, particularly among the rural populations, who can scarcely afford modern health care or ... 2New York City College of Technology, Brooklyn, NY 11210, USA ... 5g CMC, while Groups 2 and 3 rat diets contained (4.5g CMC + 0.5g bark ...

Topology of actions and homogeneous spaces

International Nuclear Information System (INIS)

Kozlov, Konstantin L

2013-01-01

Topologization of a group of homeomorphisms and its action provide additional possibilities for studying the topological space, the group of homeomorphisms, and their interconnections. The subject of the paper is the use of the property of d-openness of an action (introduced by Ancel under the name of weak micro-transitivity) in the study of spaces with various forms of homogeneity. It is proved that a d-open action of a Čech-complete group is open. A characterization of Polish SLH spaces using d-openness is given, and it is established that any separable metrizable SLH space has an SLH completion that is a Polish space. Furthermore, the completion is realized in coordination with the completion of the acting group with respect to the two-sided uniformity. A sufficient condition is given for extension of a d-open action to the completion of the space with respect to the maximal equiuniformity with preservation of d-openness. A result of van Mill is generalized, namely, it is proved that any homogeneous CDH metrizable compactum is the only G-compactification of the space of rational numbers for the action of some Polish group. Bibliography: 39 titles.

A new manganese-based oral contrast agent (CMC-001) for liver MRI. Pharmacological and pharmaceutical aspects

International Nuclear Information System (INIS)

Joergensen, Jan Troest; Rief, Matthias; Wagner, Moritz; Brismar, Torkel B.; Albiin, Nils

2012-01-01

Manganese is one of the most abundant metals on earth and is found as a component of more than 100 different minerals. Besides being an essential trace element in relation to the metabolic processes in the body, manganese is also a paramagnetic metal that possesses similar characteristics to gadolinium with regards to T1-weighted (T1-w) magnetic resonance imaging (MRI). Manganese, in the form of manganese (II) chloride tetrahydrate, is the active substance in a new targeted oral contrast agent, currently known as CMC-001, indicated for hepatobiliary MRI. Under physiological circumstances manganese is poorly absorbed from the intestine after oral intake, but by the use of specific absorption promoters, L-alanine and vitamin D3, it is possible to obtain a sufficiently high concentration in the liver in order to achieve a significant signal enhancing effect. In the liver manganese is exposed to a very high first-pass effect, up to 98 %, which prevents the metal from reaching the systemic circulation, thereby reducing the number of systemic side-effects. Manganese is one of the least toxic trace elements, and due to its favorable safety profile it may be an attractive alternative to gadolinium-based contrast agents for patients undergoing an MRI evaluation for liver metastases in the future. In this review the basic pharmacological and pharmaceutical aspects of this new targeted oral hepatobiliary specific contrast agent will be discussed

Space Robotics Challenge

Data.gov (United States)

National Aeronautics and Space Administration — The Space Robotics Challenge seeks to infuse robot autonomy from the best and brightest research groups in the robotics community into NASA robots for future...

The past and space

DEFF Research Database (Denmark)

Lund, Christian

2013-01-01

of legitimate forms of land control, complex combinations of claims emerge. The ubiquity of ‘the past’ in African politics and the increasing competition over space suggest that the naturalness with which some refer to the past and others conceive of space should be under constant scrutiny. Based on work...... that competing social elite groups instrumentalize. Each group sees its interests best served by a particular reading of the past and a particular conception of space....

SiC-SiC and C-SiC Honeycomb for Advanced Flight Structures, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The proposed project builds upon the work done in Phase I with the development of a C-SiC CMC honeycomb material that was successfully tested for mechanical...

Evaluation of the effects of subgingival injection of Simvastatin on space re-opening after orthodontic space closure in adults

Directory of Open Access Journals (Sweden)

Arezoo Jahanbin

2016-03-01

Full Text Available Background. This clinical trial evaluated the effect of Simvastatin on space re-opening after orthodontic space closure and its effect on the gingival index (GI and clinical attachment loss (CAL. Methods. 16 females, 25‒40 years old, with spaces between anterior mandibular teeth due to chronic periodontitis were participated in this study. The patients were randomly divided into control and experimental groups. In the experimental group, 1.2% Simvastatin gel and in the control group, 0.9% sodium chloride as a placebo was injected into the pocket depth of the six anterior teeth. The amount of space reopening, GI and CAL were measured. Results. No serious complications were observed during interventions and follow-up periods. Space re-opening was significantly reduced in patients receiving Simvastatin (P < 0.001. Moreover, GI reduction was significantly greater in Sim-vastatin group compared to the control group (P < 0.001. However, CAL did not demonstrate a significant difference between the groups. Conclusion. Simvastatin may decrease space re-opening after orthodontic space closure in human anterior teeth.

Detecting Lamb waves with broad-band acousto-ultrasonic signals in composite structures

Science.gov (United States)

Kautz, Harold E.

1992-01-01

Lamb waves can be produced and detected in ceramic matrix composites (CMC) and metal matrix composites (MMC) plates using the acousto-ultrasonic configuration employing broadband transducers. Experimental dispersion curves of lowest symmetric and antisymmetric modes behave in a manner analogous to the graphite/polymer theoretical curves. In this study a basis has been established for analyzing Lamb wave velocities for characterizing composite plates. Lamb wave dispersion curves and group velocities were correlated with variations in axial stiffness and shear stiffness in MMC and CMC. For CMC, interfacial shear strength was also correlated with the first antisymmetric Lamb mode.

Critical machine cluster identification using the equal area criterion

DEFF Research Database (Denmark)

Weckesser, Johannes Tilman Gabriel; Jóhannsson, Hjörtur; Østergaard, Jacob

2015-01-01

The paper introduces a new method to early identify the critical machine cluster (CMC) after a transient disturbance. For transient stability assessment with methods based on the equal area criterion it is necessary to split the generators into a group of critical and non-critical machines....... The generators in the CMC are those likely to lose synchronism. The early and reliable identification of the CMC is crucial and one of the major challenges. The proposed new approach is based on the assessment of the rotor dynamics between two machines and the evaluation of their coupling strength. A novel...

Space Science at Los Alamos National Laboratory

Science.gov (United States)

Smith, Karl

2017-09-01

The Space Science and Applications group (ISR-1) in the Intelligence and Space Research (ISR) division at the Los Alamos National Laboratory lead a number of space science missions for civilian and defense-related programs. In support of these missions the group develops sensors capable of detecting nuclear emissions and measuring radiations in space including γ-ray, X-ray, charged-particle, and neutron detection. The group is involved in a number of stages of the lifetime of these sensors including mission concept and design, simulation and modeling, calibration, and data analysis. These missions support monitoring of the atmosphere and near-Earth space environment for nuclear detonations as well as monitoring of the local space environment including space-weather type events. Expertise in this area has been established over a long history of involvement with cutting-edge projects continuing back to the first space based monitoring mission Project Vela. The group's interests cut across a large range of topics including non-proliferation, space situational awareness, nuclear physics, material science, space physics, astrophysics, and planetary physics.

Neural network based automated algorithm to identify joint locations on hand/wrist radiographs for arthritis assessment

International Nuclear Information System (INIS)

Duryea, J.; Zaim, S.; Wolfe, F.

2002-01-01

Arthritis is a significant and costly healthcare problem that requires objective and quantifiable methods to evaluate its progression. Here we describe software that can automatically determine the locations of seven joints in the proximal hand and wrist that demonstrate arthritic changes. These are the five carpometacarpal (CMC1, CMC2, CMC3, CMC4, CMC5), radiocarpal (RC), and the scaphocapitate (SC) joints. The algorithm was based on an artificial neural network (ANN) that was trained using independent sets of digitized hand radiographs and manually identified joint locations. The algorithm used landmarks determined automatically by software developed in our previous work as starting points. Other than requiring user input of the location of nonanatomical structures and the orientation of the hand on the film, the procedure was fully automated. The software was tested on two datasets: 50 digitized hand radiographs from patients participating in a large clinical study, and 60 from subjects participating in arthritis research studies and who had mild to moderate rheumatoid arthritis (RA). It was evaluated by a comparison to joint locations determined by a trained radiologist using manual tracing. The success rate for determining the CMC, RC, and SC joints was 87%-99%, for normal hands and 81%-99% for RA hands. This is a first step in performing an automated computer-aided assessment of wrist joints for arthritis progression. The software provides landmarks that will be used by subsequent image processing routines to analyze each joint individually for structural changes such as erosions and joint space narrowing

q-deformed phase-space and its lattice structure

International Nuclear Information System (INIS)

Wess, J.

1998-01-01

Quantum groups lead to an algebraic structure that can be realized on quantum spaces. These are non-commutative spaces that inherit a well-defined mathematical structure from the quantum group symmetry. In turn, such quantum spaces can be interpreted as non-commutative configuration spaces for physical systems. We study the non-commutative Euclidean space that is based on the quantum group SO q (3)

Building dialogue on complex conservation issues in a conference setting.

Science.gov (United States)

Rock, Jenny; Sparrow, Andrew; Wass, Rob; Moller, Henrik

2014-10-01

Dialogue about complex science and society issues is important for contemporary conservation agendas. Conferences provide an appropriate space for such dialogue, but despite its recognized worth, best practices for facilitating active dialogue are still being explored. Face-to-face (FTF) and computer-mediated communication (CMC) are two approaches to facilitating dialogue that have different strengths. We assessed the use of these approaches to create dialogue on cultural perspectives of conservation and biodiversity at a national ecology conference. In particular, we aimed to evaluate their potential to enhance dialogue through their integrated application. We used an interactive blog to generate CMC on participant-sourced issues and to prime subsequent discussion in an FTF conference workshop. The quantity and quality of both CMC and FTF discussion indicated that both approaches were effective in building dialogue. Prior to the conference the blog averaged 126 views per day, and 44 different authors contributed a total of 127 comments. Twenty-five participants subsequently participated in active FTF discussion during a 3-h workshop. Postconference surveys confirmed that CMC had developed participants' thinking and deepened FTF dialogue; 88% indicated specifically that CMC helped facilitate the FTF discussion. A further 83% of respondents concluded that preliminary blog discussion would be useful for facilitating dialogue at future conferences. © 2014 Society for Conservation Biology.

Wigner functions from the two-dimensional wavelet group.

Science.gov (United States)

Ali, S T; Krasowska, A E; Murenzi, R

2000-12-01

Following a general procedure developed previously [Ann. Henri Poincaré 1, 685 (2000)], here we construct Wigner functions on a phase space related to the similitude group in two dimensions. Since the group space in this case is topologically homeomorphic to the phase space in question, the Wigner functions so constructed may also be considered as being functions on the group space itself. Previously the similitude group was used to construct wavelets for two-dimensional image analysis; we discuss here the connection between the wavelet transform and the Wigner function.

Homogeneous Spaces and Equivariant Embeddings

CERN Document Server

Timashev, DA

2011-01-01

Homogeneous spaces of linear algebraic groups lie at the crossroads of algebraic geometry, theory of algebraic groups, classical projective and enumerative geometry, harmonic analysis, and representation theory. By standard reasons of algebraic geometry, in order to solve various problems on a homogeneous space it is natural and helpful to compactify it keeping track of the group action, i.e. to consider equivariant completions or, more generally, open embeddings of a given homogeneous space. Such equivariant embeddings are the subject of this book. We focus on classification of equivariant em

The cohomology of orbit spaces of certain free circle group actions

Indian Academy of Sciences (India)

Abstract. Suppose that G = S1 acts freely on a finitistic space X whose (mod p) cohomology ring is isomorphic to that of a lens space L2m−1(p;q1,...,qm) or S1 ×. CPm−1. The mod p index of the action is defined to be the largest integer n such that αn = 0, where α ϵ H2(X/G; Zp) is the nonzero characteristic class of the S1-.

INFLUENCE OF ECOLOGICAL GROUP COMPOSITION, PLANTATION SPACING AND ARRANGEMENT IN THE RESTORATION OF RIPARIAN FOREST ON RESERVOIR SHORES

Directory of Open Access Journals (Sweden)

Alvaro Augusto Vieira Soares

2016-01-01

Full Text Available This work aimed to assess the effect of spacing, arrangement and ecological group composition of planted seedlings on the restoration process of artificial reservoir shores in southeastern Brazil. The assessments were performed 12 years after the settlement of the experiment in which five mixed stand models were tested. First, a general evaluation of the stand was performed when we surveyed the overstory and understory, seed bank and soil for chemical analysis.Then, the restoration indicators survival of planted trees, basal area and density of the tree community, litter accumulated on the soil and canopy closure index were utilized to compare the plantation models and to assess the influence the experimental factors on these parameters. In the general analysis, we found that the studied stand presents low diversity, poor regeneration, and seed bank dominated mostly by one planted exotic tree species and weeds, which may jeopardize the self- maintenance of the stand in the future. The factor that most influenced the models was the ecological group composition with the best performance found for models in which both pioneer and non-pioneer groups were used. Probably, the plantation arrangement and spacing did not have greater influence due to both plant mortality and natural regeneration that has developed to this age. Hence, it is not recommended the use of only pioneer species in the implantation of riparian forest and the proportion of 50% pioneers and 50% non-pioneers using as much species as possible is indicated for areas that might present constraints for the natural regeneration.

Association and Diffusion of Li(+) in Carboxymethylcellulose Solutions for Environmentally Friendly Li-ion Batteries.

Science.gov (United States)

Casalegno, Mosè; Castiglione, Franca; Passarello, Marco; Mele, Andrea; Passerini, Stefano; Raos, Guido

2016-07-21

Carboxymethylcellulose (CMC) has been proposed as a polymeric binder for electrodes in environmentally friendly Li-ion batteries. Its physical properties and interaction with Li(+) ions in water are interesting not only from the point of view of electrode preparation-processability in water is one of the main reasons for its environmental friendliness-but also for its possible application in aqueous Li-ion batteries. We combine molecular dynamics simulations and variable-time pulsed field gradient spin-echo (PFGSE) NMR spectroscopy to investigate Li(+) transport in CMC-based solutions. Both the simulations and experimental results show that, at concentrations at which Li-CMC has a gel-like consistency, the Li(+) diffusion coefficient is still very close to that in water. These Li(+) ions interact preferentially with the carboxylate groups of CMC, giving rise to a rich variety of coordination patterns. However, the diffusion of Li(+) in these systems is essentially unrestricted, with a fast, nanosecond-scale exchange of the ions between CMC and the aqueous environment. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation and in vitro evaluation of carboxymethylated κ-carrageenan aluminum hydrogel microbeads for prolonged release of mefenamic acid

International Nuclear Information System (INIS)

Beron, Pia Maria G.; Cruzado, Shervin T.; Dela Cruz, Sharmaine F.; Estanislao, Fides Mae L.; Evangelista, Charina Joy; Mandocdoc, Larra Minnellie W.; Salas, Sharlaine B.; Tiu, Mark Brian C.; Carigma, Andrea Q.; Bayquen, Aristea V.

2012-01-01

Polymers that swell in an aqueous medium have been widely used to formulate controlled-release dosage forms. This study aims to prepare carboxymethyl κ-carrageenan (CMKC) microbeads and evaluate its potential for controlled release of mefenamic acid in comparison to the positive control, carboxymethylcellulose (CMC) microbeads. The powdered κ-carrageenan was carboxymethylated and Fourier-Transform Infrared Spectroscopy confirmed the carboxy methylation. Aqueous solutions of CMC (3% w/v) and CMKC (3%, 4%, 5% w/v) were prepared as microbeads using ionotropic gelation technique. Microbeads were loaded with mefenamic acid by suspending it in the aqueous solution (0.5% w/v) of the drug for 72 hours. Particle size and surface morphology were characterized using scanning electron microscopy. One-way ANOVA was used to determine a significant difference between the release activity of the drug-loaded CMKC and CMC microbeads. Differential Scanning Calorimetry was performed on the drug, drug- free, and drug-loaded microbeads of CMC and CMKC. Two-way ANOVARM showed significant interaction in % drug release of the three groups being analyzed in respect to time effect (p≤0.001) and group effect (p≤0.001). Post Hoc Duncan Multiple Range Test showed that 3% CMC and 4% CMKC has equal average % drug release values and is significantly higher compared to the commercial mefenamic acid. Also, one way ANOVA showed that 3% CMC was able to release the drug with no significant difference in time (p = 0.159), while 4% CMKC (p < 0.001) and the commercial mefenamic acid (p≤0.001) were able to release the drug with significant difference in time (author)

CEMCAN Software Enhanced for Predicting the Properties of Woven Ceramic Matrix Composites

Science.gov (United States)

Murthy, Pappu L. N.; Mital, Subodh K.; DiCarlo, James A.

2000-01-01

Major advancements are needed in current high-temperature materials to meet the requirements of future space and aeropropulsion structural components. Ceramic matrix composites (CMC's) are one class of materials that are being evaluated as candidate materials for many high-temperature applications. Past efforts to improve the performance of CMC's focused primarily on improving the properties of the fiber, interfacial coatings, and matrix constituents as individual phases. Design and analysis tools must take into consideration the complex geometries, microstructures, and fabrication processes involved in these composites and must allow the composite properties to be tailored for optimum performance. Major accomplishments during the past year include the development and inclusion of woven CMC micromechanics methodology into the CEMCAN (Ceramic Matrix Composites Analyzer) computer code. The code enables one to calibrate a consistent set of constituent properties as a function of temperature with the aid of experimentally measured data.

The character of free topological groups II

Directory of Open Access Journals (Sweden)

Peter Nickolas

2005-04-01

Full Text Available A systematic analysis is made of the character of the free and free abelian topological groups on metrizable spaces and compact spaces, and on certain other closely related spaces. In the first case, it is shown that the characters of the free and the free abelian topological groups on X are both equal to the “small cardinal” d if X is compact and metrizable, but also, more generally, if X is a non-discrete k!-space all of whose compact subsets are metrizable, or if X is a non-discrete Polish space. An example is given of a zero-dimensional separable metric space for which both characters are equal to the cardinal of the continuum. In the case of a compact space X, an explicit formula is derived for the character of the free topological group on X involving no cardinal invariant of X other than its weight; in particular the character is fully determined by the weight in the compact case. This paper is a sequel to a paper by the same authors in which the characters of the free groups were analysed under less restrictive topological assumptions.

The pH sensitive properties of carboxymethyl chitosan nanoparticles cross-linked with calcium ions.

Science.gov (United States)

Kalliola, Simo; Repo, Eveliina; Srivastava, Varsha; Heiskanen, Juha P; Sirviö, Juho Antti; Liimatainen, Henrikki; Sillanpää, Mika

2017-05-01

In environmental applications the applied materials are required to be non-toxic and biodegradable. Carboxymethyl chitosan nanoparticles cross-linked with Ca 2+ ions (CMC-Ca) fulfill these requirements, and they are also renewable. These nanoparticles were applied to oil-spill treatment in our previous study and here we focused on enhancing their properties. It was found that while the divalent Ca 2+ ions are crucial for the formation of the CMC-Ca, the attractive interaction between NH 3 + and COO - groups contributed significantly to the formation and stability of the CMC-Ca. The stability decreased as a function of pH due to the deprotonation of the amino groups. Therefore, the nanoparticles were found to be fundamentally pH sensitive in solution, if the pH deviated from the pH (7-9) that was used in the synthesis of the nanoparticles. The pH sensitive CMC-Ca synthesized in pH 7 and 8 were most stable in the studied conditions and could find applications in oil-spill treatment or controlled-release of substances. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Geometrical aspects of quantum spaces

International Nuclear Information System (INIS)

Ho, P.M.

1996-01-01

Various geometrical aspects of quantum spaces are presented showing the possibility of building physics on quantum spaces. In the first chapter the authors give the motivations for studying noncommutative geometry and also review the definition of a Hopf algebra and some general features of the differential geometry on quantum groups and quantum planes. In Chapter 2 and Chapter 3 the noncommutative version of differential calculus, integration and complex structure are established for the quantum sphere S 1 2 and the quantum complex projective space CP q (N), on which there are quantum group symmetries that are represented nonlinearly, and are respected by all the aforementioned structures. The braiding of S q 2 and CP q (N) is also described. In Chapter 4 the quantum projective geometry over the quantum projective space CP q (N) is developed. Collinearity conditions, coplanarity conditions, intersections and anharmonic ratios is described. In Chapter 5 an algebraic formulation of Reimannian geometry on quantum spaces is presented where Riemannian metric, distance, Laplacian, connection, and curvature have their quantum counterparts. This attempt is also extended to complex manifolds. Examples include the quantum sphere, the complex quantum projective space and the two-sheeted space. The quantum group of general coordinate transformations on some quantum spaces is also given

Axiomatics of uniform space-time models

International Nuclear Information System (INIS)

Levichev, A.V.

1983-01-01

The mathematical statement of space-time axiomatics of the special theory of relativity is given; it postulates that the space-time M is the binding single boundary Hausedorf local-compact four-dimensional topological space with the given order. The theorem is proved: if the invariant order in the four-dimensional group M is given by the semi-group P, which contingency K contains inner points , then M is commutative. The analogous theorem is correct for the group of two and three dimensionalities

Novel, Nanotechnology Based CMC composites for Hot Structures, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Very extensive R&D efforts over the past several decades resulted in several classes of high temperature composites offering potential for future hypersonic...

Space for Interaction

DEFF Research Database (Denmark)

Jørgensen, Mariane Ellen; Folmer, Mette Blicher; Mullins, Michael

SPACE FOR INTERACTION QUALIFYING GROUP TREATMENT FOR PATIENTS WITH CHRONIC PAIN THROUGH OPTIMIZATION(?) OF SPACE. A RANDOMIZED PILOT STUDY. In a Ph-D. Mariane Ellen Jørgensen / Nurse + psykoterapist / maej@rn.dk / Pain Center / Aalborg University Hospital / Denmark / Mette Blicher Folmer / Archit...

Computer Mediated Communication and the Emergence of "Electronic Opportunism"

OpenAIRE

Rocco, Elena; Warglien, Massimo

1996-01-01

An experiment on how communication affects cooperation in a social dilemma shows that computer mediated communication (CMC) and face to face communication have markedly different effects on patterns of collective behavior. While face to face communication sustains stable cooperation, CMC makes cooperative agreements in groups extremely fragile, giving rise to waves of opportunistic behavior. Further analysis of communication protocols highlights that the breakdown of ordinary communication ru...

Transplantation of Porcine Hepatocytes Cultured with Polylactic Acid-O-Carboxymethylated Chitosan Nanoparticles Promotes Liver Regeneration in Acute Liver Failure Rats

Directory of Open Access Journals (Sweden)

Zhong Chen

2011-01-01

Full Text Available In this study, free porcine hepatocytes suspension (Group A, porcine hepatocytes embedded in collagen gel (Group B, porcine hepatocytes cultured with PLA-O-CMC nanoparticles and embedded in collagen gel (Group C, and PLA-O-CMC nanoparticles alone (Group D were transplanted into peritoneal cavity of ALF rats, respectively. The result showed that plasma HGF levels were elevated post-transplantation with a peak at 12 hr. The rats in Group C showed highest plasma HGF levels at 2, 6, 12, 24 and 36 hr post-transplantation and lowest HGF level at 48 hr. Plasma VEGF levels were elevated at 48 hr post-transplantation with a peak at 72 hr. The rats in Group C showed highest plasma HGF levels at 48, 72, and 96 hr post-transplantation. The liver functions in Group C were recovered most rapidly. Compared with Group B, Group C had significant high liver Kiel 67 antigen labeling index (Ki-67 LI at day 1 post-HTx (P<.05. Ki-67 LI in groups B and C was higher than that in groups A and D at days 5 and 7 post-HTx. In conclusion, intraperitoneal transplantation of porcine hepatocytes cultured with PLA-O-CMC nanoparticles and embedded in collagen gel can promote significantly liver regeneration in ALF rats.

Antiadhesive Property of Photoreactive Azidophenyl Low-Molecular-Weight Chitosan in Rabbit Laminotomy Model

Directory of Open Access Journals (Sweden)

Jong Won Kim

2013-01-01

Full Text Available Newly developed photoreactive azidophenyl chitosan (P-ALMC has characteristics of a transformable gel type and its outer layer could be sealed up like a film after UV radiation. We aim to evaluate the antiadhesive properties of P-ALMC through comparing it with hyaluronic acid-carboxymethylcellulose membrane (HA-CMC in a rabbit laminotomy model. Laminotomies were performed at the L3-4, L4-5, and L5-6 levels in 41 rabbits and each level was randomly assigned to either receive saline (group I, HA-CMC (group II, or P-ALMC (group III. The extent of peridural fibrosis, density of fibroblasts and inflammatory cells, and dural thickness were evaluated at 6 and 12 weeks postoperatively. In the groups II and III, the extents of peridural fibrosis and dural thickness were significantly smaller than those in group I (P<0.001 and no differences between groups II and III were found at the postoperative 6 and 12 weeks. There were no differences of cell density among groups. P-ALMC showed effective antiadhesive properties comparable to HA-CMC and could be one of the candidates as an anti-adhesive agent for spine surgery even further study is required to identify the effectiveness of its unique characteristics as mechanical barrier.

Dynamics of infinite-dimensional groups the Ramsey-Dvoretzky-Milman phenomenon

CERN Document Server

Pestov, Vladimir

2006-01-01

The "infinite-dimensional groups" in the title refer to unitary groups of Hilbert spaces, the infinite symmetric group, groups of homeomorphisms of manifolds, groups of transformations of measure spaces, etc. The book presents an approach to the study of such groups based on ideas from geometric functional analysis and from exploring the interplay between dynamical properties of those groups, combinatorial Ramsey-type theorems, and the phenomenon of concentration of measure. The dynamics of infinite-dimensional groups is very much unlike that of locally compact groups. For instance, every locally compact group acts freely on a suitable compact space (Veech). By contrast, a 1983 result by Gromov and Milman states that whenever the unitary group of a separable Hilbert space continuously acts on a compact space, it has a common fixed point. In the book, this new fast-growing theory is built strictly from well-understood examples up. The book has no close counterpart and is based on recent research articles. At t...

Causal symmetric spaces

CERN Document Server

Olafsson, Gestur; Helgason, Sigurdur

1996-01-01

This book is intended to introduce researchers and graduate students to the concepts of causal symmetric spaces. To date, results of recent studies considered standard by specialists have not been widely published. This book seeks to bring this information to students and researchers in geometry and analysis on causal symmetric spaces.Includes the newest results in harmonic analysis including Spherical functions on ordered symmetric space and the holmorphic discrete series and Hardy spaces on compactly casual symmetric spacesDeals with the infinitesimal situation, coverings of symmetric spaces, classification of causal symmetric pairs and invariant cone fieldsPresents basic geometric properties of semi-simple symmetric spacesIncludes appendices on Lie algebras and Lie groups, Bounded symmetric domains (Cayley transforms), Antiholomorphic Involutions on Bounded Domains and Para-Hermitian Symmetric Spaces

Preparation and characterization of green-nano-composite material based on polyaniline, multiwalled carbon nano tubes and carboxymethyl cellulose: For electrochemical sensor applications.

Science.gov (United States)

Gautam, Vineeta; Singh, Karan Pratap; Yadav, Vijay Laxmi

2018-06-01

In this paper, we are presenting the preparation and characterization of "polyaniline/multiwalled carbon nanotubes/carboxymethyl cellulose" based novel composite material. It's morphological, thermal, structural, and electrochemical properties were investigated by using different instrumental techniques. During the in-situ chemical polymerization of aniline in the aqueous suspension of CMC and MWCNTs, the particle size change in two different ways "top to bottom" (low molecular weight oligomers grows in size) and "bottom to top" (long fibers of CMC fragmented in the reaction mixture). The combination of these two processes facilitated the fabrication of an integrated green-nano-composite material. In addition, a little amount of conductive nanofillers (MWCNTs) boosts the electrical and electrocatalytic properties of the material. Electron-rich centers of benzenoid rings exhibited π-π stacking with sp 2 carbon of MWCNTs. CMC dominantly impact on the properties of PANI, negatively charged carboxylate group of CMC ionically bonded with protonated amine/imine. FTIR and Raman analysis confirmed that the material has dominated quinoid units and effective charge transfer. Hydroxyl and carboxyl groups and bonded water molecules of CMC results in a network of hydrogen bonds (which induced directional property). PANI/MWCNTs/CMC have nanobead-like structures (TEM analysis), large surface area, large pore volume, small pore diameter (BET and BJH studies) and good dispersion ability in the aqueous phase. Nanostructures of aligned PANI exhibited excellent electrochemical properties have attracted increasing attention. Modified carbon paste electrode was used for electrocatalytic detection of ascorbic acid (as a model analyte). The sensor exhibited a linear range 0.05 mM-5 mM, sensitivity 100.63 μA mM -1  cm -2 , and limit of detection 0.01 mM. PANI/MWCNTs/CMC is suitable nanocomposite material for apply electroactive/conducting ink and membrane (which could be

Evaluation of the effects of subgingival injection of Simvastatin on space re-opening after orthodontic space closure in adults.

Science.gov (United States)

Jahanbin, Arezoo; Abtahi, Mostafa; Namdar, Parastoo; Heravi, Farzin; Sadeghi, Fatemeh; Arab, Hamidreza; Shafaee, Hooman

2016-01-01

Background. This clinical trial evaluated the effect of Simvastatin on space re-opening after orthodontic space closure and its effect on the gingival index (GI) and clinical attachment loss (CAL). Methods. 16 females, 25-40 years old, with spaces between anterior mandibular teeth due to chronic periodontitis were participated in this study. The patients were randomly divided into control and experimental groups. In the experimental group, 1.2% Simvastatin gel and in the control group, 0.9% sodium chloride as a placebo was injected into the pocket depth of the six anterior teeth. The amount of space reopening, GI and CAL were measured. Results. No serious complications were observed during interventions and follow-up periods. Space re-opening was significantly reduced in patients receiving Simvastatin (P space re-opening after orthodontic space closure in human anterior teeth.

q-deformed Minkowski space

International Nuclear Information System (INIS)

Ogievetsky, O.; Pillin, M.; Schmidke, W.B.; Wess, J.; Zumino, B.

1993-01-01

In this lecture I discuss the algebraic structure of a q-deformed four-vector space. It serves as a good example of quantizing Minkowski space. To give a physical interpretation of such a quantized Minkowski space we construct the Hilbert space representation and find that the relevant time and space operators have a discrete spectrum. Thus the q-deformed Minkowski space has a lattice structure. Nevertheless this lattice structure is compatible with the operation of q-deformed Lorentz transformations. The generators of the q-deformed Lorentz group can be represented as linear operators in the same Hilbert space. (orig.)

The third spatial dimension risk approach for individual risk and group risk in multiple use of space

International Nuclear Information System (INIS)

Suddle, Shahid; Ale, Ben

2005-01-01

Buildings above roads and railways are examples of multiple use of space. Safety is one of the critical issues for such projects. Risk analyses can be undertaken to investigate what safety measures that are required to realise these projects. The results of these analyses can also be compared to risk acceptance criteria, if they are applicable. In The Netherlands, there are explicit criteria for acceptability of individual risk and societal risk. Traditionally calculations of individual risk result in contours of equal risk on a map and thus are considered in two-dimensional space only. However, when different functions are layered the third spatial dimension, height, becomes an important parameter. The various activities and structures above and below each other impose mutual risks. There are no explicit norms or policies about how to deal with the individual or group risk approach in the third dimension. This paper proposes an approach for these problems and gives some examples. Finally, the third dimension risk approach is applied in a case study of Bos en Lommer, Amsterdam

Making media work in space: an interdisciplinary perspective on media and communication requirements for current and future space communities

Science.gov (United States)

Babidge, S.; Cokley, J.; Gordon, F.; Louw, E.

2005-10-01

As humans expand into space communities will form. These have already begun to form in small ways, such as long-duration missions on the International Space Station and the space shuttle, and small-scale tourist excursions into space. Social, behavioural and communications data emerging from such existing communities in space suggest that the physically-bounded, work-oriented and traditionally male-dominated nature of these extremely remote groups present specific problems for the resident astronauts, groups of them viewed as ‘communities’, and their associated groups who remain on Earth, including mission controllers, management and astronauts’ families. Notionally feminine group attributes such as adaptive competence, social adaptation skills and social sensitivity will be crucial to the viability of space communities and in the absence of gender equity, ‘staying in touch’ by means of ‘news from home’ becomes more important than ever. A template of news and media forms and technologies is suggested to service those needs and enhance the social viability of future terraforming activities.

Group covariance and metrical theory

International Nuclear Information System (INIS)

Halpern, L.

1983-01-01

The a priori introduction of a Lie group of transformations into a physical theory has often proved to be useful; it usually serves to describe special simplified conditions before a general theory can be worked out. Newton's assumptions of absolute space and time are examples where the Euclidian group and translation group have been introduced. These groups were extended to the Galilei group and modified in the special theory of relativity to the Poincare group to describe physics under the given conditions covariantly in the simplest way. The criticism of the a priori character leads to the formulation of the general theory of relativity. The general metric theory does not really give preference to a particular invariance group - even the principle of equivalence can be adapted to a whole family of groups. The physical laws covariantly inserted into the metric space are however adapted to the Poincare group. 8 references

The moduli space of instantons on an ALE space from 3d $\\mathcal{N}=4$ field theories

CERN Document Server

Mekareeya, Noppadol

2015-01-01

The moduli space of instantons on an ALE space is studied using the moduli space of $\\mathcal{N}=4$ field theories in three dimensions. For instantons in a simple gauge group $G$ on $\\mathbb{C}^2/\\mathbb{Z}_n$, the Hilbert series of such an instanton moduli space is computed from the Coulomb branch of the quiver given by the affine Dynkin diagram of $G$ with flavour nodes of unitary groups attached to various nodes of the Dynkin diagram. We provide a simple prescription to determine the ranks and the positions of these flavour nodes from the order of the orbifold $n$ and from the residual subgroup of $G$ that is left unbroken by the monodromy of the gauge field at infinity. For $G$ a simply laced group of type $A$, $D$ or $E$, the Higgs branch of such a quiver describes the moduli space of instantons in projective unitary group $PU(n) \\cong U(n)/U(1)$ on orbifold $\\mathbb{C}^2/\\hat{G}$, where $\\hat{G}$ is the discrete group that is in McKay correspondence to $G$. Moreover, we present the quiver whose Coulomb ...

Space station propulsion requirements study

Science.gov (United States)

Wilkinson, C. L.; Brennan, S. M.

1985-01-01

Propulsion system requirements to support Low Earth Orbit (LEO) manned space station development and evolution over a wide range of potential capabilities and for a variety of STS servicing and space station operating strategies are described. The term space station and the overall space station configuration refers, for the purpose of this report, to a group of potential LEO spacecraft that support the overall space station mission. The group consisted of the central space station at 28.5 deg or 90 deg inclinations, unmanned free-flying spacecraft that are both tethered and untethered, a short-range servicing vehicle, and a longer range servicing vehicle capable of GEO payload transfer. The time phasing for preferred propulsion technology approaches is also investigated, as well as the high-leverage, state-of-the-art advancements needed, and the qualitative and quantitative benefits of these advancements on STS/space station operations. The time frame of propulsion technologies applicable to this study is the early 1990's to approximately the year 2000.

Density character of subgroups of topological groups

OpenAIRE

Leiderman, Arkady; Morris, Sidney A.; Tkachenko, Mikhail G.

2015-01-01

A subspace Y of a separable metrizable space X is separable, but without X metrizable this is not true even If Y is a closed linear subspace of a topological vector space X. K.H. Hofmann and S.A. Morris introduced the class of pro-Lie groups which consists of projective limits of finite-dimensional Lie groups and proved that it contains all compact groups, locally compact abelian groups and connected locally compact groups and is closed under products and closed subgroups. A topological group...

“Here is the knowledge-where should I put it?” Findings from a study of how knowledge spaces are used within a support group

DEFF Research Database (Denmark)

Carstensen, P. H.; Snis, U.

1999-01-01

In order to design useful knowledge media spaces for knowledge workers it is essential that we understand the nature of the work conducted and the knowledge applied in real settings. The paper reports from a study of how a group of quality assurance specialists in the pharmaceutical industry gather......, structure and distribute information and knowledge. Based on the findings, a number of overall requirements for knowledge media spaces are identified and discussed. The essential findings were that information and knowledge are created and handled in many different ways and have many different forms....... The core issues of our lessons learned so far are that we carefully need to consider knowledge media spaces both in terms of communication channels and knowledge archives. Knowledge media spaces should be seen as spaces in which knowledge and information is exchanged, filed, retrieved, presented...

Symmetry-adapted Liouville space. Pt. 7

International Nuclear Information System (INIS)

Temme, F.P.

1990-01-01

In examining nuclear spin dynamics of NMR spin clusters in density operator/generalized torque formalisms over vertical strokekqv>> operator bases of Liouville space, it is necessary to consider the symmetry mappings and carrier spaces under a specialized group for such (k i = 1) nuclear spin clusters. The SU2 X S n group provides the essential mappings and the form of H carrier space, which allows one to: (a) draw comparisons with Hilbert space duality, and (b) outline the form of the Coleman-Kotani genealogical hierarchy under induced S n -symmetry. (orig.)

Effect of carboxymethyl cellulose concentration on physical properties of biodegradable cassava starch-based films

Directory of Open Access Journals (Sweden)

Sriburi Pensiri

2011-02-01

Full Text Available Abstract Background Cassava starch, the economically important agricultural commodity in Thailand, can readily be cast into films. However, the cassava starch film is brittle and weak, leading to inadequate mechanical properties. The properties of starch film can be improved by adding plasticizers and blending with the other biopolymers. Results Cassava starch (5%w/v based films plasticized with glycerol (30 g/100 g starch were characterized with respect to the effect of carboxymethyl cellulose (CMC concentrations (0, 10, 20, 30 and 40%w/w total solid and relative humidity (34 and 54%RH on the mechanical properties of the films. Additionally, intermolecular interactions were determined by Fourier transform infrared spectroscopy (FT-IR, melting temperature by differential scanning calorimetry (DSC, and morphology by scanning electron microscopy (SEM. Water solubility of the films was also determined. Increasing concentration of CMC increased tensile strength, reduced elongation at break, and decreased water solubility of the blended films. FT-IR spectra indicated intermolecular interactions between cassava starch and CMC in blended films by shifting of carboxyl (C = O and OH groups. DSC thermograms and SEM micrographs confirmed homogeneity of cassava starch-CMC films. Conclusion The addition of CMC to the cassava starch films increased tensile strength and reduced elongation at break of the blended films. This was ascribed to the good interaction between cassava starch and CMC. Cassava starch-CMC composite films have the potential to replace conventional packaging, and the films developed in this work are suggested to be suitable for low moisture food and pharmaceutical products.

Critical Dynamics of the Xy-Model on the One-Dimensional Superlattice by Position Space Renormalization Group

Science.gov (United States)

Lima, J. P. De; Gonçalves, L. L.

The critical dynamics of the isotropic XY-model on the one-dimensional superlattice is considered in the framework of the position space renormalization group theory. The decimation transformation is introduced by considering the equations of motion of the operators associated to the excitations of the system, and it corresponds to an extension of the procedure introduced by Stinchcombe and dos Santos (J. Phys. A18, L597 (1985)) for the homogeneous lattice. The dispersion relation is obtained exactly and the static and dynamic scaling forms are explicitly determined. The dynamic critical exponent is also obtained and it is shown that it is identical to the one of the XY-model on the homogeneous chain.

"Con Café, Compañerismo, y Calidad": Latina Women Fashioning a Writing Group into a Space of Praxis and Belonging

Science.gov (United States)

Hurtig, Janise

2016-01-01

This article explores the spatial practices through which a group of Mexican immigrant women, participants in a school-based writing workshop I facilitated for four years, molded and gave meaning to our weekly writing routine to foster inclusivity as the basis for collective teaching and learning--creating what I refer to as a space of praxis and…

Preparation of minor ginsenosides C-Mc, C-Y, F2, and C-K from American ginseng PPD-ginsenoside using special ginsenosidase type-I from Aspergillus niger g.848.

Science.gov (United States)

Liu, Chun-Ying; Zhou, Rui-Xin; Sun, Chang-Kai; Jin, Ying-Hua; Yu, Hong-Shan; Zhang, Tian-Yang; Xu, Long-Quan; Jin, Feng-Xie

2015-07-01

Minor ginsenosides, those having low content in ginseng, have higher pharmacological activities. To obtain minor ginsenosides, the biotransformation of American ginseng protopanaxadiol (PPD)-ginsenoside was studied using special ginsenosidase type-I from Aspergillus niger g.848. DEAE (diethylaminoethyl)-cellulose and polyacrylamide gel electrophoresis were used in enzyme purification, thin-layer chromatography and high performance liquid chromatography (HPLC) were used in enzyme hydrolysis and kinetics; crude enzyme was used in minor ginsenoside preparation from PPD-ginsenoside; the products were separated with silica-gel-column, and recognized by HPLC and NMR (Nuclear Magnetic Resonance). The enzyme molecular weight was 75 kDa; the enzyme firstly hydrolyzed the C-20 position 20-O-β-D-Glc of ginsenoside Rb1, then the C-3 position 3-O-β-D-Glc with the pathway Rb1→Rd→F2→C-K. However, the enzyme firstly hydrolyzed C-3 position 3-O-β-D-Glc of ginsenoside Rb2 and Rc, finally hydrolyzed 20-O-L-Ara with the pathway Rb2→C-O→C-Y→C-K, and Rc→C-Mc1→C-Mc→C-K. According to enzyme kinetics, K m and V max of Michaelis-Menten equation, the enzyme reaction velocities on ginsenosides were Rb1 > Rb2 > Rc > Rd. However, the pure enzyme yield was only 3.1%, so crude enzyme was used for minor ginsenoside preparation. When the crude enzyme was reacted in 3% American ginseng PPD-ginsenoside (containing Rb1, Rb2, Rc, and Rd) at 45°C and pH 5.0 for 18 h, the main products were minor ginsenosides C-Mc, C-Y, F2, and C-K; average molar yields were 43.7% for C-Mc from Rc, 42.4% for C-Y from Rb2, and 69.5% for F2 and C-K from Rb1 and Rd. Four monomer minor ginsenosides were successfully produced (at low-cost) from the PPD-ginsenosides using crude enzyme.

Automorphisms of p-compact groups and their root data

DEFF Research Database (Denmark)

Andersen, Kasper K. S.; Grodal, Jesper Kragh

2008-01-01

We construct a model for the space of automorphisms of a connected p–compact group in terms of the space of automorphisms of its maximal torus normalizer and its root datum. As a consequence we show that any homomorphism to the outer automorphism group of a p–compact group can be lifted to a group...... action, analogous to   a classical theorem of de Siebenthal for compact Lie groups. The model of this paper is used in a crucial way in our paper `The classification of 2-compact groups' [arXiv:math.AT/0611437], where we prove the conjectured classification of 2–compact groups and determine...... their automorphism spaces....

Producing Irony in Adolescence: A Comparison Between Face-to-Face and Computer-Mediated Communication

Directory of Open Access Journals (Sweden)

Aguert Marc

2016-12-01

Full Text Available The literature suggests that irony production expands in the developmental period of adolescence. We aimed to test this hypothesis by investigating two channels: face-to-face and computer-mediated communication (CMC. Corpora were collected by asking seventh and 11th graders to freely discuss some general topics (e.g., music, either face-to-face or on online forums. Results showed that 6.2% of the 11th graders’ productions were ironic utterances, compared with just 2.5% of the seventh graders’ productions, confirming the major development of irony production in adolescence. Results also showed that adolescents produced more ironic utterances in CMC than face-to-face. The analysis suggested that irony use is a strategy for increasing in-group solidarity and compensating for the distance intrinsic to CMC, as it was mostly inclusive and well-marked on forums. The present study also confirmed previous studies showing that irony is compatible with CMC.

Space Station Workshop: Commercial Missions and User Requirements

Science.gov (United States)

1988-01-01

The topics of discussion addressed during a three day workshop on commercial application in space are presented. Approximately half of the program was directed towards an overview and orientation to the Space Station Project; the technical attributes of space; and present and future potential commercial opportunities. The remaining time was spent addressing technological issues presented by previously-formed industry working groups, who attempted to identify the technology needs, problems or issues faced and/or anticipated by the following industries: extraction (mining, agriculture, petroleum, fishing, etc.); fabrication (manufacturing, automotive, aircraft, chemical, pharmaceutical and electronics); and services (communications, transportation and retail robotics). After the industry groups presented their technology issues, the workshop divided into smaller discussion groups composed of: space experts from NASA; academia; industry experts in the appropriate disciplines; and other workshop participants. The needs identified by the industry working groups, space station technical requirements, proposed commercial ventures and other issues related to space commercialization were discussed. The material summarized and reported are the consensus from the discussion groups.

Geometry, rigidity, and group actions

CERN Document Server

Farb, Benson; Zimmer, Robert J

2011-01-01

The study of group actions is more than a hundred years old but remains to this day a vibrant and widely studied topic in a variety of mathematic fields. A central development in the last fifty years is the phenomenon of rigidity, whereby one can classify actions of certain groups, such as lattices in semi-simple Lie groups. This provides a way to classify all possible symmetries of important spaces and all spaces admitting given symmetries. Paradigmatic results can be found in the seminal work of George Mostow, Gergory Margulis, and Robert J. Zimmer, among others.The p

Banded versus Single-sided bonded space maintainers: A Comparative Study

Directory of Open Access Journals (Sweden)

Sudhir Mittal

2018-01-01

Full Text Available Background: The present study is conducted to evaluate and compare the clinical performance of conventional band and loop space maintainer and fiber reinforced composite resin (FRCR space maintainers. Materials and Methods: A total of 45 extraction sites in the age group of 6–9 years having premature loss of primary molars or indicated for extraction were selected for the study. The patients were randomly divided into three groups as Group I, in which conventional band and loop space maintainer was given, Group II and Group III (FRCR, in which FRCR (everStick CandB and impregnated glass fibers (Interlig space maintainers were given, respectively. Patients were recalled at 3, 6, and 12-month interval for evaluation of all the three types of space maintainer. Results: Overall success rate of Group I was 86.7%, for Group II was 80%, and for Group III was 73.3% at the end of the study. Patient acceptability was significantly higher in Group II and Group III (FRCR as compared to Group I (Conventional band and loop. In Group I, cement loss and fracture of loop, whereas in Group II and Group III, debonding at enamel composite was the most common failure followed by debonding at fiber composite and fiber fracture. FRCR space maintainers were found to be cost-effective as compared to Group I. More linear changes and angular changes were recorded in Group I as compared to Group II and Group III but difference was not significant (P > 0.05. Conclusion: Only single (buccal surface application of FRCR space maintainers showed almost equal clinical efficacy compared to conventional band and loop space maintainer with significantly better patient acceptability, less cost, and time taken.

Generalizations of the BMS group and results

International Nuclear Information System (INIS)

Melas, E

2006-01-01

The ordinary Bondi-Metzner-Sachs (BMS) group B is the common asymptotic symmetry group of all radiating, asymptotically flat, Lorentzian space-times. As such, B is the best candidate for the universal symmetry group of General Relativity. However, in studying quantum gravity, space-times with signatures other than the usual Lorentzian one, and complex space-times, are frequently considered. Generalisations of B appropriate to these other signatures have been defined earlier. In particular, the generalization B(2, 2) appropriate to the ultrahyperbolic signature (+, +, -, -) has been described in detail, and the study of its irreducible unitary representations (IRs) has been initiated. The infinite little groups of B(2, 2) have been given explicitly but its finite little groups have only been partially described. All the information needed in order to construct the finite little groups is given. Possible connections with gravitational instantons are being put forward

A Space Apart

Directory of Open Access Journals (Sweden)

Lisa Lynch

2017-01-01

Full Text Available This article examines how the preschool child is enabled to withdraw from the peer group and create a private, individual space within the institutional collective. The question under consideration is, “What factors are necessary to enable a child to create and maintain a withdrawal space in the preschool?” Data were collected through ethnographic fieldwork at two Montessori schools in the south of Sweden. Analysis of the results reveals that a child is enabled through a combination of two elements: a level of opportunity to create a space and a level of defense of a created space. These two factors are dependent on the teachers’ ability to correctly identify space creation, alongside their desire for the child’s space creation effort to be successful.

Thiolated polymers: synthesis and in vitro evaluation of polymer-cysteamine conjugates.

Science.gov (United States)

Bernkop-Schnürch, A; Clausen, A E; Hnatyszyn, M

2001-09-11

The purpose of the present study was to synthesize and characterize novel thiolated polymers. Mediated by a carbodiimide cysteamine was covalently linked to sodium carboxymethylcellulose (CMC) and polycarbophil (PCP). The resulting CMC-cysteamine conjugates displayed 77.9+/-6.7 and 365.1+/-8.7 micromol thiol groups per gram of polymer, whereas the PCP-cysteamine conjugates showed 26.3+/-1.9 and 122.7+/-3.8 micromol thiol groups per gram of polymer (mean+/-S.D.; n=3). In aqueous solutions above pH 5.0 both modified polymers were capable of forming inter- and/or intra-molecular disulfide bonds. The reaction velocity of this oxidation process was accelerated with a decrease in the proton concentration. The oxidation proceeded more rapidly within thiolated CMC than within thiolated PCP. Permeation studies carried out in Ussing-type chambers with freshly excised intestinal mucosa from guinea pigs utilizing sodium fluorescein as model drug for the paracellular uptake revealed an enhancement ratio (R=P(app) (conjugate)/P(app) (control)) of 1.15 and 1.41 (mean+/-S.D.; n=3) for the higher thiolated CMC-cysteamine (0.5%; m/v) and PCP-cysteamine conjugate (1.0%; m/v), respectively. The decrease in the transepithelial electrical resistance values was in good correlation with the enhancement ratios. Due to a high crosslinking tendency by the formation of disulfide bonds stabilizing drug carrier systems based on thiolated polymers and a permeation enhancing effect, CMC- and PCP-cysteamine conjugates represent promising excipients for the development of novel drug delivery systems.

Temperature Effect on Micelle Formation: Molecular Thermodynamic Model Revisited.

Science.gov (United States)

Khoshnood, Atefeh; Lukanov, Boris; Firoozabadi, Abbas

2016-03-08

Temperature affects the aggregation of macromolecules such as surfactants, polymers, and proteins in aqueous solutions. The effect on the critical micelle concentration (CMC) is often nonmonotonic. In this work, the effect of temperature on the micellization of ionic and nonionic surfactants in aqueous solutions is studied using a molecular thermodynamic model. Previous studies based on this technique have predicted monotonic behavior for ionic surfactants. Our investigation shows that the choice of tail transfer energy to describe the hydrophobic effect between the surfactant tails and the polar solvent molecules plays a key role in the predicted CMC. We modify the tail transfer energy by taking into account the effect of the surfactant head on the neighboring methylene group. The modification improves the description of the CMC and the predicted micellar size for aqueous solutions of sodium n-alkyl sulfate, dodecyl trimethylammonium bromide (DTAB), and n-alkyl polyoxyethylene. The new tail transfer energy describes the nonmonotonic behavior of CMC versus temperature. In the DTAB-water system, we redefine the head size by including the methylene group, next to the nitrogen, in the head. The change in the head size along with our modified tail transfer energy improves the CMC and aggregation size prediction significantly. Tail transfer is a dominant energy contribution in micellar and microemulsion systems. It also promotes the adsorption of surfactants at fluid-fluid interfaces and affects the formation of adsorbed layer at fluid-solid interfaces. Our proposed modifications have direct applications in the thermodynamic modeling of the effect of temperature on molecular aggregation, both in the bulk and at the interfaces.

Can virtual seminars be used cost‐effectively to enhance student learning?

OpenAIRE

Halfpenny, Peter; Wellings, Sonja

2001-01-01

This paper describes a virtual seminar initiative designed to investigate the extent to which computer‐mediated communication (CMC) can cost‐effectively strengthen staff‐student interaction and enhance student group discussion, and thereby improve collaborative learning. After setting the scene by means of a brief review of the discursive potential of CMC, the establishment of an asynchronous bulletin board system on three modules in the Department of Sociology at the University of Manchester...

Invariant subsets under compact quantum group actions

OpenAIRE

Huang, Huichi

2012-01-01

We investigate compact quantum group actions on unital $C^*$-algebras by analyzing invariant subsets and invariant states. In particular, we come up with the concept of compact quantum group orbits and use it to show that countable compact metrizable spaces with infinitely many points are not quantum homogeneous spaces.

Space dynamics

International Nuclear Information System (INIS)

Corno, S.E.

1995-01-01

Analytical methods for Space Dynamics of fission reactors, are presented. It is shown how a few sample problems in space dynamics can be solved, within the one and two group diffusion model, by purely analytical tools, essentially based on Laplace transform and complex Green function techniques. A quite suggestive generalization of this approach, applicable to the fluid core reactors, whose fuel is undergoing a violent mixing, is reported and briefly discussed. (author)

Consciousness viewed in the framework of brain phase space dynamics, criticality, and the Renormalization Group

International Nuclear Information System (INIS)

Werner, Gerhard

2013-01-01

The topic of this paper will be addressed in three stages: I will first review currently prominent theoretical conceptualizations of the neurobiology of consciousness and, where appropriate, identify ill-advised and flawed notions in theoretical neuroscience that may impede viewing consciousness as a phenomenon in the physics of brain. In this context, I will also introduce relevant facts that tend not to receive adequate attention in much of the current consciousness discourse. Next, I will review the evidence that accrued in the last decade that identifies the resting brain as being in a state of criticality. In the framework of state phase dynamics of statistical physics, this observational evidence also entails that the resting brain is poised at the brink of a second order phase transition. On this basis, I will in the third stage propose applying the framework of the Renormalization Group to viewing consciousness as a phenomenon in statistical physics. In physics, concepts of phase space transitions and the Renormalization Group are powerful tools for interpreting phenomena involving many scales of length and time in complex systems. The significance of these concepts lies in their accounting for the emergence of different levels of new collective behaviors in complex systems, each level with its distinct macroscopic physics, organization, and laws, as a new pattern of reality. In this framework, I propose to view subjectivity as the symbolic description of the physical brain state of consciousness that emerges as one of the levels of phase transitions of the brain-body-environment system, along the trajectory of Renormalization Group Transformations

Responding to the Concerns of Student Cultural Groups: Redesigning Spaces for Cultural Centers

Science.gov (United States)

McDowell, Anise Mazone; Higbee, Jeanne L.

2014-01-01

This paper describes the engagement of a student committee in redesigning an entire floor of a university union to accommodate student cultural centers and provide space in a fair and equitable manner. The reorganization focused on the process as well as the task of allocating space, with an emphasis on the opportunity to foster the development of…

Everyday spaces of inter-ethnic interaction: the meaning of urban public spaces in the Netherlands

NARCIS (Netherlands)

Peters, K.B.M.; Haan, de H.J.

2011-01-01

Ethnic diversity is manifest in public spaces by the presence of people originating from all over the world. It is also manifest in typical ethnic spaces that are predominantly used by specific ethnic groups. This article focuses on how people from various ethnic backgrounds use urban public spaces

Homology groups for particles on one-connected graphs

Science.gov (United States)

MaciÄ Żek, Tomasz; Sawicki, Adam

2017-06-01

We present a mathematical framework for describing the topology of configuration spaces for particles on one-connected graphs. In particular, we compute the homology groups over integers for different classes of one-connected graphs. Our approach is based on some fundamental combinatorial properties of the configuration spaces, Mayer-Vietoris sequences for different parts of configuration spaces, and some limited use of discrete Morse theory. As one of the results, we derive the closed-form formulae for ranks of the homology groups for indistinguishable particles on tree graphs. We also give a detailed discussion of the second homology group of the configuration space of both distinguishable and indistinguishable particles. Our motivation is the search for new kinds of quantum statistics.

Cooled Ceramic Matrix Composite Propulsion Structures Demonstrated

Science.gov (United States)

Jaskowiak, Martha H.; Dickens, Kevin W.

2005-01-01

NASA's Next Generation Launch Technology (NGLT) Program has successfully demonstrated cooled ceramic matrix composite (CMC) technology in a scramjet engine test. This demonstration represented the world s largest cooled nonmetallic matrix composite panel fabricated for a scramjet engine and the first cooled nonmetallic composite to be tested in a scramjet facility. Lightweight, high-temperature, actively cooled structures have been identified as a key technology for enabling reliable and low-cost space access. Tradeoff studies have shown this to be the case for a variety of launch platforms, including rockets and hypersonic cruise vehicles. Actively cooled carbon and CMC structures may meet high-performance goals at significantly lower weight, while improving safety by operating with a higher margin between the design temperature and material upper-use temperature. Studies have shown that using actively cooled CMCs can reduce the weight of the cooled flow-path component from 4.5 to 1.6 lb/sq ft and the weight of the propulsion system s cooled surface area by more than 50 percent. This weight savings enables advanced concepts, increased payload, and increased range. The ability of the cooled CMC flow-path components to operate over 1000 F hotter than the state-of-the-art metallic concept adds system design flexibility to space-access vehicle concepts. Other potential system-level benefits include smaller fuel pumps, lower part count, lower cost, and increased operating margin.

Space Station Habitability Research

Science.gov (United States)

Clearwater, Yvonne A.

1988-01-01

The purpose and scope of the Habitability Research Group within the Space Human Factors Office at the NASA/Ames Research Center is described. Both near-term and long-term research objectives in the space human factors program pertaining to the U.S. manned Space Station are introduced. The concept of habitability and its relevancy to the U.S. space program is defined within a historical context. The relationship of habitability research to the optimization of environmental and operational determinants of productivity is discussed. Ongoing habitability research efforts pertaining to living and working on the Space Station are described.

Topological transformation groups and Dugundji compacta

International Nuclear Information System (INIS)

Kozlov, Konstantin L; Chatyrko, Vitalii A

2010-01-01

The presence of an algebraic structure on a space, which is compatible with its topology, in many cases imposes very strong restrictions on the properties of the space itself. Conditions are found which must be satisfied by the actions in order for the phase space to be a d-space (Dugundji compactum). This investigation allows the range of G-spaces that are d-spaces (Dugundji compacta) to be substantially widened. It is shown that all the cases known to the authors where a G-space (a topological group, one of its quotient spaces) is a d-space can be realized using equivariant maps. Bibliography: 39 titles.

Spaces of homotopy self-equivalences a survey

CERN Document Server

Rutter, John W

1997-01-01

This survey covers groups of homotopy self-equivalence classes of topological spaces, and the homotopy type of spaces of homotopy self-equivalences. For manifolds, the full group of equivalences and the mapping class group are compared, as are the corresponding spaces. Included are methods of calculation, numerous calculations, finite generation results, Whitehead torsion and other areas. Some 330 references are given. The book assumes familiarity with cell complexes, homology and homotopy. Graduate students and established researchers can use it for learning, for reference, and to determine the current state of knowledge.

Space Biology and Medicine. Volume 4; Health, Performance, and Safety of Space Crews

Science.gov (United States)

Dietlein, Lawrence F. (Editor); Pestov, Igor D. (Editor)

2004-01-01

Volume IV is devoted to examining the medical and associated organizational measures used to maintain the health of space crews and to support their performance before, during, and after space flight. These measures, collectively known as the medical flight support system, are important contributors to the safety and success of space flight. The contributions of space hardware and the spacecraft environment to flight safety and mission success are covered in previous volumes of the Space Biology and Medicine series. In Volume IV, we address means of improving the reliability of people who are required to function in the unfamiliar environment of space flight as well as the importance of those who support the crew. Please note that the extensive collaboration between Russian and American teams for this volume of work resulted in a timeframe of publication longer than originally anticipated. Therefore, new research or insights may have emerged since the authors composed their chapters and references. This volume includes a list of authors' names and addresses should readers seek specifics on new information. At least three groups of factors act to perturb human physiological homeostasis during space flight. All have significant influence on health, psychological, and emotional status, tolerance, and work capacity. The first and most important of these factors is weightlessness, the most specific and radical change in the ambient environment; it causes a variety of functional and structural changes in human physiology. The second group of factors precludes the constraints associated with living in the sealed, confined environment of spacecraft. Although these factors are not unique to space flight, the limitations they entail in terms of an uncomfortable environment can diminish the well-being and performance of crewmembers in space. The third group of factors includes the occupational and social factors associated with the difficult, critical nature of the

Riesz basis for strongly continuous groups.

NARCIS (Netherlands)

Zwart, Heiko J.

Given a Hilbert space and the generator of a strongly continuous group on this Hilbert space. If the eigenvalues of the generator have a uniform gap, and if the span of the corresponding eigenvectors is dense, then these eigenvectors form a Riesz basis (or unconditional basis) of the Hilbert space.

′Metal to resin′: A comparative evaluation of conventional band and loop space maintainer with the fiber reinforced composite resin space maintainer in children

Directory of Open Access Journals (Sweden)

A Garg

2014-01-01

Full Text Available Aims: To compare the clinical efficacy of two space maintainers namely, conventional band and loop and Fiber Reinforced Composite Resin (FRCR space maintainers . Subjects and Methods: Thirty healthy children, aged 5 to 8 years were selected having at least two deciduous molars in different quadrants indicated for extraction or lost previously. FRCR space maintainer was placed in one quadrant and in the other quadrant band and loop space maintainer was cemented. All the patients were recalled at 1 st , 3 rd , and 6 th months for evaluation of both types of space maintainer. Patient acceptability, time taken, and clinical efficacy was recorded. Statistical analysis used: The observations thus obtained were subjected to statistical analysis using Chi- square test and Mann-Whitney U test. Results: Patient acceptability was greater in Group I (FRCR in comparison to Group II (band and loop space maintainer. The time taken by Group I was significantly lower as compared to that of Group II. In Group I, debonding of enamel, composite was the most common complication leading to failure followed by debonding of fiber composite. In Group II, cement loss was the most common complication leading to failure followed by slippage of band and fracture of loop. The success rates of Groups I and Group II weares 63.3% and 36.7%, respectively. Conclusion: The study concluded that FRCRFiber Reinforced Composite Resin (Ribbond space maintainers can be considered as viable alternative to the conventional band and loop space maintainers.

Integrated Advanced Monopropellant CMC Thruster / Thermal Stand-Off Assembly, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — High performance non-toxic monopropellants offer significant benefits relative to the current state-of-the-art. The benefits of these advanced monopropellants (AMP)...

Concept for an International Standard related to Space Weather Effects on Space Systems

Science.gov (United States)

Tobiska, W. Kent; Tomky, Alyssa

There is great interest in developing an international standard related to space weather in order to specify the tools and parameters needed for space systems operations. In particular, a standard is important for satellite operators who may not be familiar with space weather. In addition, there are others who participate in space systems operations that would also benefit from such a document. For example, the developers of software systems that provide LEO satellite orbit determination, radio communication availability for scintillation events (GEO-to-ground L and UHF bands), GPS uncertainties, and the radiation environment from ground-to-space for commercial space tourism. These groups require recent historical data, current epoch specification, and forecast of space weather events into their automated or manual systems. Other examples are national government agencies that rely on space weather data provided by their organizations such as those represented in the International Space Environment Service (ISES) group of 14 national agencies. Designers, manufacturers, and launchers of space systems require real-time, operational space weather parameters that can be measured, monitored, or built into automated systems. Thus, a broad scope for the document will provide a useful international standard product to a variety of engineering and science domains. The structure of the document should contain a well-defined scope, consensus space weather terms and definitions, and internationally accepted descriptions of the main elements of space weather, its sources, and its effects upon space systems. Appendices will be useful for describing expanded material such as guidelines on how to use the standard, how to obtain specific space weather parameters, and short but detailed descriptions such as when best to use some parameters and not others; appendices provide a path for easily updating the standard since the domain of space weather is rapidly changing with new advances

Efeitos da injeção intraorbitária de carboximetilcelulose 6,0% em coelhos: análise histológica e da mecânica ocular Effects of intraorbital injection of 6.0% carboxymethylcellulose in rabbits: histological and ocular mechanics evaluation

Directory of Open Access Journals (Sweden)

Maria Lúcia Habib Simão

2009-12-01

divided into two experimental groups: one treated with a peribulbar injection of 6.0% CMC and a control group submitted to peribulbar injection of 3.0 cc of physiological saline. The group submitted to peribulbar CMC injection was divided into four subgroups respectively receiving the following volumes: 1.0, 1.5, 2.0 and 3.0 cc. The force needed to promote tangential adduction dislocations, external ophthalmologic signs and intraocular pressure were evaluated. The animals were sacrificed on the 60th day after the injection for histological analysis. RESULTS: The mean force detected 60 days after the injection of 6.0% CMC was lower in the 1.0 treated subgroup and higher in the 1.5, 2.0 and 3.0 treated subgroups relative to the force before injection. Histological analysis revealed histiocytic infiltration with fibrosis in the subgroups in which there was an increase in force and the presence of CMC in periocular tissues. CONCLUSIONS: 6.0% CMC acted as a modifier of the oculomotor system of rabbits, facilitating or impairing movements. It was not possible to conclude whether the increase in force occurred as a consequence of the inflammatory process alone or of the sum of inflammation and a possible viscous attrition provoked by CMC.

Nuclear power in space

International Nuclear Information System (INIS)

Aftergood, S.; Hafemeister, D.W.; Prilutsky, O.F.; Rodionov, S.N.; Primack, J.R.

1991-01-01

Nuclear reactors have provided energy for satellites-with nearly disastrous results. Now the US government is proposing to build nuclear-powered boosters to launch Star Wars defenses. These authors represent scientific groups that are opposed to the use of nuclear power in near space. The authors feel that the best course for space-borne reactors is to ban them from Earth orbit and use them in deep space

Problem and Project Based Learning in Hybrid Spaces

DEFF Research Database (Denmark)

Ryberg, Thomas; Davidsen, Jacob; Hodgson, Vivien

2016-01-01

There is a need within networked learning to understand and conceptualise the interplay between digital and physical spaces or what we could term hybrid spaces. Therefore, we discuss a recent study of students from two different programmes who are engaged in long-term, group-based problem...... and project based learning. Based on interviews, workshops and observations of students’ actual group practices in open, shared and flexible spaces in Aalborg University (AAU), we identify and discuss how students incorporate networked and digital technologies into their group work and into the study places...... they create for themselves. We describe how in one of the programmes ‘nomadic’ groups of students used different technologies and spaces for ‘placemaking’. We then show how their experience and approach to collaborative work differs to that of the more static or ‘artisan’ groups of students in the other...

The coadjoint orbit spaces of Diff(S1) and Teichmueller spaces

International Nuclear Information System (INIS)

Nag, S.; Verjovsky, A.

1989-09-01

Precisely two of the homogeneous spaces that appear as coadjoint orbits of the group of string reparametrizations (Diff (S 1 )) carry in a natural way the structure of infinite dimensional, holomorphically homogeneous complex analytic Kaehler manifolds. These are N = Diff (S 1 )/Rot (S 1 ) and M = Diff (S 1 )/Moeb (S 1 ). Note that N is a holomorphic disc fiber space over M. Now, M can be naturally considered as embedded in the classical universal Teichmueller space T(1), simply by noting that a diffeomorphism of S 1 is a quasisymmetric homeomorphism. T(1) is itself a homomorphically homogeneous complex Banach manifold. We prove in the first part of the paper that the inclusion of M in T(1) is complex analytic. In the latter portion of this paper it is shown that the unique homogeneous Kaehler metric carried by M = Diff (S 1 )/SL(2, R) induces precisely the Weil-Petersson metric on the Teichmueller space. This is via our identification of M as a holomorphic submanifold of universal Teichmueller space. Now recall that every Teichmueller space T(G) of finite or infinite dimension is contained canonically and holomorphically within T(1). Our computations allow us also to prove that every T(G), G any infinite Fuchsian group, projects out of M transversely. This last assertion is related to the ''fractal'' nature of G-invariant quasicircles, and to Mostow rigidity on the line. Our results thus connect the loop space approach to bosonic string theory with the sumover moduli (Polyakov path integral) approach. (author). 21 refs

Automorphism group of nonabelian groups of order p{sup 3}

Energy Technology Data Exchange (ETDEWEB)

Sarmin, Nor Haniza [Department of Mathematical Sciences, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru (Malaysia); Barakat, Yasamin [Department of Mathematical Sciences, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Malaysia and Islamic Azad University-Ahvaz Branch, Ahvaz (Iran, Islamic Republic of)

2014-06-19

Let G be a nonabelian group of order p{sup 3}, where p is a prime number. Then G is a two generated group that its commutator, centre and Frattini subgroup coincide and are of order p. Hence, the quotient group of G over its centre and also Frattini quotient group of G, both are of order p{sup 2}. However, the first mentioned quotient is isomorphic to the inner group of G, which is a normal subgroup of automorphism group of G. Whereas, Frattini quotient group of G is an abelian elementary group that can be considered as a vector space of dimension two over Z{sub p}, the field of integers modulo p. In this paper, we consider to apply these properties of G to characterize the automorphism group of G.

The generalization of the Schur multipliers of Bieberbach groups

Science.gov (United States)

Masri, Rohaidah; Hassim, Hazzirah Izzati Mat; Sarmin, Nor Haniza; Ali, Nor Muhainiah Mohd; Idrus, Nor'ashiqin Mohd

2014-12-01

The Schur multiplier is the second homology group of a group. It has been found to be isomorphic to the kernel of a homomorphism which maps the elements in the exterior square of the group to the elements in its derived subgroup. Meanwhile, a Bieberbach group is a space group which is a discrete cocompact group of isometries of oriented Euclidean space. In this research, the Schur multipliers of Bieberbach groups with cyclic point group of order two of finite dimension are computed.

Lightweight Ultrahigh Temperature CMC-Lined C/C Combustion Chambers, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — NASA and DoD are seeking high-performance, lightweight liquid rocket combustion chambers with future performance goals that cannot be achieved using state-of-the-art...

Nuclear safety policy working group recommendations on nuclear propulsion safety for the space exploration initiative

Science.gov (United States)

Marshall, Albert C.; Lee, James H.; Mcculloch, William H.; Sawyer, J. Charles, Jr.; Bari, Robert A.; Cullingford, Hatice S.; Hardy, Alva C.; Niederauer, George F.; Remp, Kerry; Rice, John W.

1993-01-01

An interagency Nuclear Safety Working Group (NSPWG) was chartered to recommend nuclear safety policy, requirements, and guidelines for the Space Exploration Initiative (SEI) nuclear propulsion program. These recommendations, which are contained in this report, should facilitate the implementation of mission planning and conceptual design studies. The NSPWG has recommended a top-level policy to provide the guiding principles for the development and implementation of the SEI nuclear propulsion safety program. In addition, the NSPWG has reviewed safety issues for nuclear propulsion and recommended top-level safety requirements and guidelines to address these issues. These recommendations should be useful for the development of the program's top-level requirements for safety functions (referred to as Safety Functional Requirements). The safety requirements and guidelines address the following topics: reactor start-up, inadvertent criticality, radiological release and exposure, disposal, entry, safeguards, risk/reliability, operational safety, ground testing, and other considerations.

Summary of Research 1997, Interdisciplinary Academic Groups

National Research Council Canada - National Science Library

Boger, Dan

1999-01-01

This report contains information of research projects in the interdisciplinary groups, Command, Control, and Communications Academic Group, Information Warfare Academic Group, Space Systems Academic...

2004 Space Report: Environment and Strategy for Space Research at NATO's Research and Technology Organisation (RTO)

Science.gov (United States)

Woods-Vedeler, Jessica A.

2007-01-01

This report describes the motivation for and a strategy to enhance the NATO Research and Technology Organisation's (RTO) current space research effort to reflect NATO's growing military dependence on space systems. Such systems and services provided by these systems are critical elements of military operations. NATO uses space systems for operational planning and support, communication, radio navigation, multi-sensor and multi-domain demonstrations. Such systems are also used to promote regional stability. A quantitative analysis of work related to space in the NATO RTO showed that during the period of 1998 - 2004, 5% of the research pursued in the NATO RTO has been clearly focused on space applications. Challenging environmental and organizational barriers for increasing RTO space research were identified. In part, these include lack of sufficient space expertise representation on panels, the military sensitivity of space, current panel work loads and the need for specific technical recommendations from peers. A strategy for enhancing space research in the RTO is to create a limited-life Space Advisory Group (SAG) composed of Space Expert Consultants who are panel members with appropriate expertise and additional expertise from the nations. The SAG will recommend and find support in the nations for specific technical activities related to space in the areas of Space Science, Remote Sensing Data Analysis, Spacecraft Systems, Surveillance and Early Warning, Training and Simulation and Policy. An RTO Space Advisory Group will provide an organizational mechanism to gain recognition of RTO as a forum for trans-Atlantic defence space research and to enhance space research activities.

Crystallographic Investigations into Properties of Acentric Hybrid Perovskite Single Crystals NH(CH3)3SnX3(X = Cl, Br)

KAUST Repository

Dang, Yangyang

2016-10-11

The hybrid perovskites with special optoelectronic properties have attracted more attention to the scientific and industrial applications. However, because of the toxicity and instability of lead complexes, there is interest in finding a nontoxic substitute for the lead in the halides perovskites and solving the ambiguous crystal structures and phase transition of NH(CH3)3SnX3 (X = Cl, Br). Here, we report the bulk crystal growths and different crystal morphologies of orthorhombic hybrid perovskites NH(CH3)3SnX3 (X = Cl, Br) in an ambient atmosphere by bottom-seeded solution growth (BSSG) method. More importantly, detailed structural determination and refinements, phase transition, band gap, band structure calculations, nonlinear optical (NLO) properties, XPS, thermal properties, and stability of NH(CH3)3SnX3 (X = Cl, Br) single crystals are demonstrated. NH(CH3)3SnCl3 single crystal undergoes reversible structural transformation from orthorhombic space group Cmc21 (no. 36) to monoclinic space group Cc (no. 9) and NH(CH3)3SnBr3 belongs to the orthorhombic space group Pna21 (no. 33) by DSC, single-crystal X-ray diffraction and temperature-dependent SHG measurements, which clarify the former results. These results should pave the way for further studies of these materials in optoelectronics.

Esrange Space Center, a Gate to Space

Science.gov (United States)

Widell, Ola

Swedish Space Corporation (SSC) is operating the Esrange Space Center in northern Sweden. Space operations have been performed for more than 40 years. We have a unique combination of maintaining balloon and rocket launch operations, and building payloads, providing space vehicles and service systems. Sub-orbital rocket flights with land recovery and short to long duration balloon flights up to weeks are offered. The geographical location, land recovery area and the long term experience makes Swedish Space Corporation and Esrange to an ideal gate for space activities. Stratospheric balloons are primarily used in supporting atmospheric research, validation of satellites and testing of space systems. Balloon operations have been carried out at Esrange since 1974. A large number of balloon flights are yearly launched in cooperation with CNES, France. Since 2005 NASA/CSBF and Esrange provide long duration balloon flights to North America. Flight durations up to 5 days with giant balloons (1.2 Million cubic metres) carrying heavy payload (up to 2500kg) with astronomical instruments has been performed. Balloons are also used as a crane for lifting space vehicles or parachute systems to be dropped and tested from high altitude. Many scientific groups both in US, Europe and Japan have indicated a great need of long duration balloon flights. Esrange will perform a technical polar circum balloon flight during the summer 2008 testing balloon systems and flight technique. We are also working on a permission giving us the opportunity on a circular stratospheric balloon flight around the North Pole.

On the structure and applications of the Bondi-Metzner-Sachs group

Science.gov (United States)

Alessio, Francesco; Esposito, Giampiero

This work is a pedagogical review dedicated to a modern description of the Bondi-Metzner-Sachs (BMS) group. Minkowski space-time has an interesting and useful group of isometries, but, for a generic space-time, the isometry group is simply the identity and hence provides no significant informations. Yet symmetry groups have important role to play in physics; in particular, the Poincaré group describing the isometries of Minkowski space-time plays a role in the standard definitions of energy-momentum and angular-momentum. For this reason alone it would seem to be important to look for a generalization of the concept of isometry group that can apply in a useful way to suitable curved space-times. The curved space-times that will be taken into account are the ones that suitably approach, at infinity, Minkowski space-time. In particular we will focus on asymptotically flat space-times. In this work, the concept of asymptotic symmetry group of those space-times will be studied. In the first two sections we derive the asymptotic group following the classical approach which was basically developed by Bondi, van den Burg, Metzner and Sachs. This is essentially the group of transformations between coordinate systems of a certain type in asymptotically flat space-times. In the third section the conformal method and the notion of “asymptotic simplicity” are introduced, following mainly the works of Penrose. This section prepares us for another derivation of the BMS group which will involve the conformal structure, and is thus more geometrical and fundamental. In the subsequent sections we discuss the properties of the BMS group, e.g. its algebra and the possibility to obtain as its subgroup the Poincaré group, as we may expect. The paper ends with a review of the BMS invariance properties of classical gravitational scattering discovered by Strominger, that are finding application to black hole physics and quantum gravity in the literature.

Kinematic algebras, groups for elementary particles, and the geometry of momentum space

International Nuclear Information System (INIS)

Izmest'ev, A.A.

1986-01-01

It is shown that to each n-dimensional (n≥2) homogeneous isotropic Riemannian momentum (coordinate) space there corresponds a definite kinematic local algebra of operators N/sub a/, M/sub a//sub b/, P/sub a//sub ,/ ω(a,b = 1,2,...,n). In the three-dimensional case this gives the possibility of classifying particles in accordance with the algebras of the types of momentum space. The approach developed also makes it possible to obtain generalized equations describing particles of the different types. The operators under consideration satisfy not only the relevant algebra but also relations independent of the algebra that coincide in form with the Maxwell equations

[Consideration about chemistry, manufacture and control (CMC) key problems in simplified registration of classical traditional Chinese medicine excellent prescriptions].

Science.gov (United States)

Wang, Zhi-Min; Liu, Ju-Yan; Liu, Xiao-Qian; Wang, De-Qin; Yan, Li-Hua; Zhu, Jin-Jin; Gao, Hui-Min; Li, Chun; Wang, Jin-Yu; Li, Chu-Yuan; Ni, Qing-Chun; Huang, Ji-Sheng; Lin, Juan

2017-05-01

As an outstanding representative of traditional Chinese medicine(TCM) prescriptions accumulated from famous TCM doctors' clinical experiences in past dynasties, classical TCM excellent prescriptions (cTCMeP) are the most valuable part of TCM system. To support the research and development of cTCMeP, a series of regulations and measures were issued to encourage its simplified registration. There is still a long-way to go because many key problems and puzzles about technology, registration and administration in cTCMeP R&D process are not resolved. Based on the analysis of registration and management regulations of botanical drug products in FDA of USA and Japan, and EMA of Europe, the possible key problems and countermeasures in chemistry, manufacture and control (CMC) of simplified registration of cTCMeP were analyzed on the consideration of its actual situation. The method of "reference decoction extract by traditional prescription" (RDETP) was firstly proposed as standard to evaluate the quality and preparation uniformity between the new developing product under simplified registration and traditional original usages of cTCMeP, instead of Standard Decoction method in Japan. "Totality of the evidence" approach, mass balance and bioassay/biological assay of cTCMeP were emphatically suggested to introduce to the quality uniformity evaluation system in the raw drug material, drug substance and final product between the modern product and traditional decoction. Copyright© by the Chinese Pharmaceutical Association.

Girls InSpace project: A new space physics outreach initiative.

Science.gov (United States)

Abe Pacini, A.; Tegbaru, D.; Max, A., Sr.

2017-12-01

We present here the concept and state-of-art of the new space physics youth education and outreach initiative called "Girls InSpace project". The project goal is to spread quality scientific information to underrepresented groups, motivate girls in STEM and promote gender equality in the Space Physics area. Initially, the "Girls InSpace project" will be available in two languages (Portuguese and English) aiming to reach out to the youth of Brazil, United States, Nigeria, South Africa, Ethiopia and Angola. Eventually, the material will be translated to French and Spanish, focusing on French-speaking countries in Africa and Latin America. The project spans a collection of four books about a group of young girls and their adventures (always related to the sky and simultaneously introducing earth and space science concepts). Ancillary content such as a webpage, mobile applications and lesson plans are also in development. The books were written by a Space Physicist PhD woman, illustrated by a Brazilian young artist and commented by senior female scientists, creating positive role models for the next generation of girls in STEM. The story lines were drawn around the selected topics of astronomy and space physics, introducing scientific information to the target readers (girls from 8-13 years old) and enhancing their curiosity and critical thinking. The books instill the readers to explore the available extra web-content (with images, videos, interviews with scientists, real space data, coding and deeper scientific information) and game apps (with Virtual Reality components and real space images). Moreover, for teachers K-12, a collection of lesson plans will be made available, aiming to facilitate scientific content discussed in the books and inside classroom environments. Gender bias in STEM reported earlier this year in Nature and based on a study of the American Geophysical Union's member database showed a competitive disadvantage for women in the Earth and Space

Hydrogen desorption from mechanically milled carbon micro coils hydrogenated at high temperature

International Nuclear Information System (INIS)

Yoshio Furuya; Shuichi Izumi; Seiji Motojima; Yukio Hishikawa

2005-01-01

Carbon micro coils (CMC) have been prepared by the catalytic pyrolysis of acetylene at 750-800 C. The as grown coils have an almost amorphous structure and contain about 1 mass% hydrogen. They have 0.1 - 10 mm coil length, 1-5 μm coil diameter, 0.1-0.5 μm coil pitch and about 100 m 2 /g specific surface area. They were graphitized, as maintaining the morphology of the coils, by heat-treating at a higher temperature than 2500 C in Ar atmosphere. The layer space (d) of graphitized CMC was determined to be 0.341 nm, forming a 'herringbone' structure with an inclination of 10-40 degree versus the coiled fiber axis, having a specific surface area of about 8 m 2 /g. The hydrogen absorption behaviors of CMC were investigated from RT to 1200 C by a thermal desorption spectrometry (TDS) using a quadrupole mass analyzer. In TDS measurements, pre-existing hydrogen, which was due to the residual acetylene incorporated into CMC on its growing, desorbed from 700 C and peaked at about 900 C. The increment in the main peak of desorbed hydrogen in the as-grown CMC heat-treated at 500 C for 1 h under high pressure of hydrogen gas (1.9 or 8.9 MPa) was not remarkable as is shown in Fig.1. While, in the CMC samples milled mechanically for 1 h at RT using a planetary ball mill, the increase of desorbed hydrogen became to be great with the hydrogen pressure (up to 8.9 MPa) on heat-treating at 500 C, as is shown in Fig.2. In these CMC samples, the building up temperature of the hydrogen desorption was shifted to a lower one and the temperature range of desorption became to be wider than those in the as-grown CMC because of the appearance of another desorption peak at about 600 C in addition to the peak ranging from 850 C to 900 C. The same kind of peak was also slightly observed in as-grown CMC (Fig.1). It is clear that this desorption at about 600 C has contributed to the remarkable increase of desorbed hydrogen in the milled CMC. In this work, values of more than 2 mass% were obtained

Quantum groups: Geometry and applications

International Nuclear Information System (INIS)

Chu, C.S.

1996-01-01

The main theme of this thesis is a study of the geometry of quantum groups and quantum spaces, with the hope that they will be useful for the construction of quantum field theory with quantum group symmetry. The main tool used is the Faddeev-Reshetikhin-Takhtajan description of quantum groups. A few content-rich examples of quantum complex spaces with quantum group symmetry are treated in details. In chapter 1, the author reviews some of the basic concepts and notions for Hopf algebras and other background materials. In chapter 2, he studies the vector fields of quantum groups. A compact realization of these vector fields as pseudodifferential operators acting on the linear quantum spaces is given. In chapter 3, he describes the quantum sphere as a complex quantum manifold by means of a quantum stereographic projection. A covariant calculus is introduced. An interesting property of this calculus is the existence of a one-form realization of the exterior differential operator. The concept of a braided comodule is introduced and a braided algebra of quantum spheres is constructed. In chapter 4, the author considers the more general higher dimensional quantum complex projective spaces and the quantum Grassman manifolds. Differential calculus, integration and braiding can be introduced as in the one dimensional case. Finally, in chapter 5, he studies the framework of quantum principal bundle and construct the q-deformed Dirac monopole as a quantum principal bundle with a quantum sphere as the base and a U(1) with non-commutative calculus as the fiber. The first Chern class can be introduced and integrated to give the monopole charge

Rietveld refinement of magnetic structures from pulsed-neutron-source powder-diffraction data

International Nuclear Information System (INIS)

Robinson, R.A.; Lawson, A.C.; Larson, A.C.; Von Dreele, R.B.; Goldstone, J.A.

1994-01-01

The General Structure Analysis System, GSAS, has recently been modified to include magnetic neutron- scattering cross-sections. Low-temperature diffraction data have been taken on the hexagonal noncollinear antiferromagnet UPdSn on both the HIPD and the NPD powder diffractometers ail LANSCE. The low-resolution data reveal that the magnetic structure has orthorhombic symmetry (magnetic space group P c m'c2 1 ) between 25K and 40K, and monoclinic symmetry (magnetic space group PC 1121 ) below 25K. The high-resolution data reveal that there are structural distortions with corresponding symmetry changes in each of these phases, to give chemical space groups Cmc2 1 and P2 1 , respectively, while the paramagnetic phase above 40K has space group P6 3 mc. Using GSAS, we have refined data sets from both diffractometers simultaneously, including both magnetic and structural cross-sections. Magnetoelastic coefficients for the distortions have been extracted and we have determined the sign of the coupling between the structural monoclinicity and the magnetic monoclinicity. The magnetic results from Rietveld refinement are in good agreement with model fitting to the integrated intensities of seven independent magnetic reflections and these, in turn, agree with measurements made on the same sample using the constant-wavelength reactor technique. Our results therefore validate, to some level, both the technique of using spallation sources for complicated magnetic structures and the specifics of the GSAS Rietveld code

Computer-mediated communication and interpersonal attraction: an experimental test of two explanatory hypotheses.

Science.gov (United States)

Antheunis, Marjolijn L; Valkenburg, Patti M; Peter, Jochen

2007-12-01

The aims of this study were (a) to investigate the influence of computer-mediated communication (CMC) on interpersonal attraction and (b) to examine two underlying processes in the CMC-interpersonal attraction relationship. We identified two variables that may mediate the influence of CMC on interpersonal attraction: self-disclosure and direct questioning. Focusing on these potential mediating variables, we tested two explanatory hypotheses: the CMC-induced direct questioning hypothesis and the CMC-induced self-disclosure hypothesis. Eighty-one cross-sex dyads were randomly assigned to one of three experimental conditions: text-only CMC, visual CMC, and face-to-face communication. We did not find a direct effect of CMC on interpersonal attraction. However, we did find two positive indirect effects of text-only CMC on interpersonal attraction: text-only CMC stimulated both self-disclosure and direct questioning, both of which in turn enhanced interpersonal attraction. Results are discussed in light of uncertainty reduction theory and CMC theories.

On irreducible representations of the ultrahyperbolic BMS group