Enhanced backscatter of optical beams reflected in turbulent air.

PubMed

Nelson, W; Palastro, J P; Wu, C; Davis, C C

2015-07-01

Optical beams propagating through air acquire phase distortions from turbulent fluctuations in the refractive index. While these distortions are usually deleterious to propagation, beams reflected in a turbulent medium can undergo a local recovery of spatial coherence and intensity enhancement referred to as enhanced backscatter (EBS). Here we validate the commonly used phase screen simulation with experimental results obtained from lab-scale experiments. We also verify theoretical predictions of the dependence of the turbulence strength on EBS. Finally, we present a novel algorithm called the "tilt-shift method" which allows detection of EBS in frozen turbulence, reducing the time required to detect the EBS signal.

Comparing depth-dependent curing radiant exposure and time of curing of regular and flow bulk-fill composites.

PubMed

Rodrigues, Jose Augusto; Tenorio, Ilana Pais; Mello, Ginger Baranhuk Rabello de; Reis, André Figueiredo; Shen, Chiayi; Roulet, Jean-François

2017-08-21

The effect of restoration depth on the curing time of a conventional and two bulk-fill composite resins by measuring microhardness and the respective radiosity of the bottom surface of the specimen was investigated. 1-, 3- and 5-mm thick washers were filled with Surefil SDR Flow-U (SDR), Tetric EvoCeram Bulk Fill-IVA (TEC) or Esthet-X HD-B1 (EHD), and cured with Bluephase® G2 for 40s. Additional 1-mm washers were filled with SDR, TEC or EHD, placed above the light sensor of MARC®, stacked with pre-cured 1-, 3- or 5-mm washer of respective material, and cured for 2.5~60s to mimic 2-, 4- and 6-mm thick composite curing. The sensor measured the radiosity (EB) at the bottom of specimen stacks. Vickers hardness (VH) was measured immediately at 5 locations with triplicate specimens. Nonlinear regression of VH vs EB by VH=α[1-exp(-EB/β)] with all thickness shows that the values of α, maximum hardness, are 21.6±1.0 kg/mm2 for SDR, 38.3±0.6 kg/mm2 for TEC and 45.3±2.6 kg/mm2 for EHD, and the values of β, rate parameter, are 0.40±0.06 J/cm2 for SDR, 0.77±0.04 J/cm2 for TEC and 0.58±0.09 J/cm2 for EHD. The radiosity of the bottom surface was calculated when the bottom surface of each material attained 80% of α of each material. The curing times for each material are in agreement with manufacturer recommendation for thickness. It is possible to estimate time needed to cure composite resin of known depth adequately by the radiosity and microhardness of the bottom surface.

Electron beam technologies in Poland state of the art and possibilities of development

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

Wojcicki, S.

1994-12-31

The recent state of high energy electron beam /EB/ used for metals melting and welding in Poland has been presented. Some typical construction of EB furnaces and EB welding machines designed and constructed in Institute of Vacuum Technology in Warsaw are shown. The examples of their application has also been described.

Comparison of the decomposition characteristics of aromatic VOCs using an electron beam hybrid system

NASA Astrophysics Data System (ADS)

Son, Youn-Suk; Kim, Ki-Joon; Kim, Ji-Yong; Kim, Jo-Chun

2010-12-01

We applied a hybrid technique to assess the decomposition characteristics of ethylbenzene and toluene that annexed the catalyst technique with existing electron beam (EB) technology. The removal efficiency of ethylbenzene in the EB-catalyst hybrid turned out to be 30% greater than that of EB-only treatment. We concluded that ethylbenzene was decomposed more easily than toluene by EB irradiation. We compared the independent effects of the EB-catalyst hybrid and catalyst-only methods, and observed that the efficiency of the EB-catalyst hybrid demonstrated approximately 6% improvement for decomposing toluene and 20% improvement for decomposing ethylbenzene. The G-values for ethylbenzene increased with initial concentration and reactor type: for example, the G-values by reactor type at 2800 ppmC were 7.5-10.9 (EB-only) and 12.9-25.7 (EB-catalyst hybrid). We also observed a significant decrease in by-products as well as in the removal efficiencies associated with the EB-catalyst hybrid technique.

Electron beam irradiated polymer electrolyte film: Morphology, dielectric and AC conductivity studies

NASA Astrophysics Data System (ADS)

Yesappa, L.; Niranjana, M.; Ashokkumar, S. P.; Vijeth, H.; Ganesh, S.; Devendrappa, H.

2018-05-01

The polymer (PVdF-co-HFP: LiClO4=90:10, PHL10) electrolyte films prepared by solution casting method and studied morphology, dielectric properties and ac conductivity before and after electron beam (EB) irradiation. The polarized optical micrographs reveals size of spherulite reduced with increasing EB dose represents increase in amorphousity. The dielectric measurements were studied at different temperatures and observed increase with frequency at different temperatures upon EB irradiation. The ac conductivity increases with frequency due to effect of EB dose.

Treatment of toluene and its by-products using an electron beam/ultra-fine bubble hybrid system

NASA Astrophysics Data System (ADS)

Son, Youn-Suk; Kim, Tae-Hun; Choi, Chang Yong; Park, Jun-Hyeong; Ahn, Ji-Won; Dinh, Trieu-Vuong

2018-03-01

Although, until quite recently, many technologies (electron beam (EB), plasma, and ultraviolet) have been studied to overcome disadvantages of conventional methods (such as absorption, adsorption, biofiltration and incineration) for treatment of volatile organic compounds (VOCs), their techniques still have some problems such as formation of a by-product. Generally, it is reported that various by-products are generated from the EB irradiation process to remove VOCs. Therefore, we developed an electron beam/ultra-fine bubble (EB/UB) hybrid system to enhance removal efficiency of a VOC (toluene) and to reduce its by-products formed by electron beam irradiation. As a result, the removal efficiency of toluene (30 ppm) by only EB (10 kGy) was 80.1%. However, the removal efficiency of toluene using the hybrid system (water temperature: 5 ℃) was increased up to 17% when compared to only EB (10 kGy). Additionally, the 65.2% of ozone formed from the EB process was removed in UB reactor. In case of other trace by-products such as undesired VOCs and aldehydes, the levels were lowered down to the below detection limit by the subsequent UB reactor. We also found that the amount of toluene collected and solubilized into water is affected by the water temperature in the UB reactor.

Edge roughness evaluation method for quantifying at-size beam blur in electron-beam lithography

NASA Astrophysics Data System (ADS)

Yoshizawa, Masaki; Moriya, Shigeru

2000-07-01

At-size beam blur at any given pattern size of an electron beam (EB) direct writer, HL800D, was quantified using the new edge roughness evaluation (ERE) method to optimize the electron-optical system. We characterized the two-dimensional beam-blur dependence on the electron deflection length of the EB direct writer. The results indicate that the beam blur ranged from 45 nm to 56 nm in a deflection field 2520 micrometer square. The new ERE method is based on the experimental finding that line edge roughness of a resist pattern is inversely proportional to the slope of the Gaussian-distributed quasi-beam-profile (QBP) proposed in this paper. The QBP includes effects of the beam blur, electron forward scattering, acid diffusion in chemically amplified resist (CAR), the development process, and aperture mask quality. The application the ERE method to investigating the beam-blur fluctuation demonstrates the validity of the ERE method in characterizing the electron-optical column conditions of EB projections such as SCALPEL and PREVAIL.

Investigation of electron beam irradiation effects on anti-nutritional factors, chemical composition and digestion kinetics of whole cottonseed, soybean and canola seeds

NASA Astrophysics Data System (ADS)

Ebrahimi-Mahmoudabad, S. R.; Taghinejad-Roudbaneh, M.

2011-12-01

This study was completed to determine effects of electron beam (EB) irradiation at doses of 15, 30 and 45 kGy on anti-nutritional factors, ruminal degradation and in vitro crude protein (CP) digestibility of whole cottonseed (WCS), soybean (SB) and canola seeds (CS). EB-irradiation eliminated completely ( P<0.001) phytic acid of WCS, SB and CS at a dose of 30 kGy. EB-irradiation decreased linearly ( P<0.001) the total glucosinolate content of CS. Trypsin inhibitor activity of 15, 30 and 45 kGy EB-irradiated SB was decreased by 19, 73 and 88%, respectively. Free gossypol content of WCS was reduced linearly ( P<0.001) by irradiation. EB-irradiation increased linearly ( P<0.001) CP digestibility of feeds. In conclusion, EB-irradiation was an effective processing method for improving the nutritive value of WCS, SB and CS.

Electron-Beam Atomic Spectroscopy for In Situ Measurements of Melt Composition for Refractory Metals: Analysis of Fundamental Physics and Plasma Models

NASA Astrophysics Data System (ADS)

Gasper, Paul Joseph; Apelian, Diran

2015-04-01

Electron-beam (EB) melting is used for the processing of refractory metals, such as Ta, Nb, Mo, and W. These metals have high value and are critical to many industries, including the semiconductor, aerospace, and nuclear industries. EB melting can also purify secondary feedstock, enabling the recovery and recycling of these materials. Currently, there is no method for measuring melt composition in situ during EB melting. Optical emission spectroscopy of the plasma generated by EB impact with vapor above the melt, a technique here termed electron-beam atomic spectroscopy, can be used to measure melt composition in situ, allowing for analysis of melt dynamics, facilitating improvement of EB melting processes and aiding recycling and recovery of these critical and high-value metals. This paper reviews the physics of the plasma generation by EB impact by characterizing the densities and energies of electrons, ions, and neutrals, and describing the interactions between them. Then several plasma models are introduced and their suitability to this application analyzed. Lastly, a potential method for calibration-free composition measurement is described and the challenges for implementation addressed.

Combined effects of microwaves, electron beams and polyfunctional monomers on rubber vulcanization.

PubMed

Manaila, Elena; Martin, Diana; Stelescu, Daniela Zuga; Craciun, Gabriela; Ighigeanu, Daniel; Matei, Constantin

2009-01-01

This paper presents comparative results obtained by conventional vulcanization with benzoyl peroxide (CV-BP), separate electron beam vulcanization (EB-V) and simultaneous electron beam and microwave vulcanization (EB+MW-V) applied to two kind of rubber samples: EVA (ethylene vinyl acetate) rubber-sample (EVA-sample) and EPDM (ethylene-propylene terpolymer) rubber-sample (EPDM-sample). The EVA-samples contain 61.54% EVA Elvax 260, 30.77% carbon black, 1.85% TAC (triallylcyanurate) polyfunctional monomer and 5.84% filler (zinc oxide, stearic acid, polyethylene glycol and antioxidant). The EPDM-samples contain 61.54% EPDM Nordel 4760, 30.77% carbon black, 1.85% TMPT (trimethylopropane trimethacrylate) polyfunctional monomer and 5.84% filler (zinc oxide, stearic acid, polyethylene glycol and antioxidant). The rubber samples designed for different vulcanization methods were obtained from raw rubber mixtures, as compressed sheets of 2 mm in the polyethylene foils to minimize oxidation. For EB and EB + MW treatments the sheets were cut in rectangular shape 0.15 x 0.15 m2. The physical properties of samples obtained by CV-BP EV-Vand EB + MW-V methods were evaluated by measuring the tearing strength, residual elongation, elongation at break, tensile strength, 300% modulus, 100% modulus, elasticity and hardness. The obtained results demonstrate an improvement of rubber several properties obtained by EB and EB + MW processing as compared to classical procedure using benzoyl peroxide.

An experimental investigation of wastewater treatment using electron beam irradiation

NASA Astrophysics Data System (ADS)

Emami-Meibodi, M.; Parsaeian, M. R.; Amraei, R.; Banaei, M.; Anvari, F.; Tahami, S. M. R.; Vakhshoor, B.; Mehdizadeh, A.; Fallah Nejad, N.; Shirmardi, S. P.; Mostafavi, S. J.; Mousavi, S. M. J.

2016-08-01

Electron beam (EB) is used for disinfection and treatment of different types of sewage and industrial wastewater. However, high capital investment required and the abundant energy consumed by this process raise doubts about its cost-effectiveness. In this paper, different wastewaters, including two textile sewages and one municipal wastewater are experimentally studied under different irradiation strategies (i.e. batch, 60 l/min and 1000 m3/day) in order to establish the reliability and the optimum conditions for the treatment process. According to the results, EB improves the efficiency of traditional wastewater treatment methods, but, for textile samples, coagulation before EB irradiation is recommended. The cost estimation of EB treatment compared to conventional methods shows that EB has been more expensive than chlorination and less expensive than activated sludge. Therefore, EB irradiation is advisable if and only if conventional methods of textile wastewater treatment are insufficient or chlorination of municipal wastewater is not allowed for health reasons. Nevertheless, among the advanced oxidation processes (AOP), EB irradiation process may be the most suitable one in industrial scale operations.

Etched beam splitters in InP/InGaAsP.

PubMed

Norberg, Erik J; Parker, John S; Nicholes, Steven C; Kim, Byungchae; Krishnamachari, Uppiliappan; Coldren, Larry A

2011-01-17

An etched beam splitter (EBS) photonic coupler based on frustrated total internal reflection (FTIR) is designed, fabricated and characterized in the InP/InGaAsP material system. The EBS offers an ultra compact footprint (8x11 μm) and a complete range of bar/cross coupling ratio designs. A novel pre-etching process is developed to achieve sufficient depth of the etched coupling gaps. Fabricated EBS couplers demonstrate insertion loss between 1 and 2.6 dB with transmission (cross-coupling) ≤ 10%. The results show excellent agreement with 3D finite-difference time-domain (FDTD) modeling. The coupling of EBS has weak wavelength dependence in the C-band, making it suitable for wavelength division multiplexing (WDM) or other wide bandwidth applications. Finally, the EBS is integrated with active semiconductor optical amplifier (SOA) and phase-modulator components; using a flattened ring resonator structure, a channelizing filter tunable in both amplitude and center frequency is demonstrated, as well as an EBS coupled ring laser.

Electron beam accelerators—trends in radiation processing technology for industrial and environmental applications in Latin America and the Caribbean

NASA Astrophysics Data System (ADS)

Parejo Calvo, Wilson A.; Duarte, Celina L.; Machado, Luci Diva B.; Manzoli, Jose E.; Geraldo, Aurea Beatriz C.; Kodama, Yasko; Silva, Leonardo Gondim A.; Pino, Eddy S.; Somessari, Elizabeth S. R.; Silveira, Carlos G.; Rela, Paulo R.

2012-08-01

The radiation processing technology for industrial and environmental applications has been developed and used worldwide. In Latin America and the Caribbean and particularly in Brazil there are 24 and 16 industrial electron beam accelerators (EBA) respectively with energy from 200 keV to 10 MeV, operating in private companies and governmental institutions to enhance the physical and chemical properties of materials. However, there are more than 1500 high-current electron beam accelerators in commercial use throughout the world. The major needs and end-use markets for these electron beam (EB) units are R and D, wire and electric cables, heat shrinkable tubes and films, PE foams, tires, components, semiconductors and multilayer packaging films. Nowadays, the emerging opportunities in Latin America and the Caribbean are paints, adhesives and coatings cure in order to eliminate VOCs and for less energy use than thermal process; disinfestations of seeds; and films and multilayer packaging irradiation. For low-energy EBA (from 150 keV to 300 keV). For mid-energy EBA (from 300 keV to 5 MeV), they are flue gas treatment (SO2 and NOX removal); composite and nanocomposite materials; biodegradable composites based on biorenewable resources; human tissue sterilization; carbon and silicon carbide fibers irradiation; irradiated grafting ion-exchange membranes for fuel cells application; electrocatalysts nanoparticles production; and natural polymers irradiation and biodegradable blends production. For high-energy EBA (from 5 MeV to 10 MeV), they are sterilization of medical, pharmaceutical and biological products; gemstone enhancement; treatment of industrial and domestic effluents and sludge; preservation and disinfestations of foods and agricultural products; soil disinfestations; lignocellulosic material irradiation as a pretreatment to produce ethanol biofuel; decontamination of pesticide packing; solid residues remediation; organic compounds removal from wastewater; and treatment of effluent from petroleum production units and liquid irradiation process to treat vessel water ballast. On the other hand, there is a growing need of mobile EB facilities for different applications in South America.

Effects of electron beam irradiation on chemical composition, antinutritional factors, ruminal degradation and in vitro protein digestibility of canola meal

NASA Astrophysics Data System (ADS)

Taghinejad-Roudbaneh, M.; Ebrahimi, S. R.; Azizi, S.; Shawrang, P.

2010-12-01

The aim of the present study was to determine the impact of electron beam (EB) irradiation at doses of 15, 30 and 45 kGy on the nutritional value of canola meal. The phytic acid and total glucosinolate content of EB-irradiated canola meal decreased as irradiation doses increased ( P<0.01). From in situ results, irradiation of canola meal at doses of 45 kGy decreased ( P<0.05) the effective degradibility of crude protein (CP) by 14%, compared with an untreated sample. In vitro CP digestibility of EB-irradiated canola meal at doses of 15 and 30 kGy was improved ( P<0.05). Electrophoresis results showed that napin and cruciferin sub-units of 30 and 45 kGy EB-irradiated canola meal were more resistant to degradation, compared with an untreated sample. Electron beam irradiation was effective in protecting CP from ruminal degradation and reducing antinutritional factors of irradiated canola meal.

A Preliminary Investigation of the E-Beam Induced Polymerization of Maleimide and Norbornene End-capped Polyimides

NASA Technical Reports Server (NTRS)

Palmese, Giuseppe R.; Meador, Michael A. (Technical Monitor)

2005-01-01

A research area of high activity in connection with aerospace engineering has been the development of polymer thermosetting resins that can resist temperature as high as 300 C while maintaining adequate toughness, and providing ease of processing to enable low temperature and low cost composite fabrication methods. In order to meet such requirements, sequential interpenetrating polymer networks (IPNs) based on bismaleimide (BMI) and cyanate ester (CE) monomers were investigated. In these systems, a polycyanurate network is first formed in the presence of BMI and appropriate reactive diluent monomers and in a second step, a network based on the BMI is created in the presence of a fully formed polycyanurate network. The materials developed can be processed at relatively low temperature (less than 150 C) and with the aid of electron beam (EB) curing. Of major importance to the success of this work was the identification of a reactive diluent that improves ease of processing and has tailored reactivity to allow for the controlled synthesis of CE-BMI sequential IPNs. Based on solubility and reactivity of a number of reactive diluents, N-acryloylmorpholine (AMP) was selected as a comonomer for BMI copolymerization. A donor-acceptoreaction mechanism was suggested to explain the relative reactivity of a variety of reactive diluents towards maleimide functionality. The optimum processing parameters for the formation of the first network were determined through the study of metal catalyzed cure and hydrolysis of cyanate esters, whereas the reaction behavior for second network formation in terms of the influence of EB dose rate and temperature was elucidated through an in-situ kinetics study of maleimide and AMP copolymerization. Structure-property relationships were developed which allowed for the design of improved resin systems. In particular, appropriate network coupler possessing cyanate ester and maleimide functionality was synthesized to link the polycyanurate first network to the BMI/AMP second network and thus form linked sequential IPNs (LIPNs). Consequently, Tg as high as 370 C was achieved and a fracture toughness of 120 Joules per square meters was obtained for resin systems that possess adequately low viscosity for processing using liquid molding techniques at low temperature.

Control of natural microorganisms in chamomile (Chamomilla recutita L.) by gamma ray and electron beam irradiation.

PubMed

Al-Bachir, Mahfouz

2017-01-01

Microbial contamination levels and corresponding sensitivities to gamma rays (GR) and elec- tron beam (EB) irradiation were tested in chamomile (Chamomile recutta L.). Chamomile powders were treated with 10 and 20 kGy by GR and EB, respectively. Microbiological and chemical analyses were performed on controls and treated samples immediately after irradiation, and after 12 months of storage. The control samples of chamomile exhibited rather high microbiological contamination, exceeding the levels of 4 log10 CFU g-1   (CFU - colony forming units) reported by national and international authorities as the maximum permissible total count level. Irradiation with GR and EB was found to cause a reduction in microbial contamination proportionate to the dose delivered. The sterilizing effect of EB on microorganisms was higher than the GR one. A dose of 10 kGy of GR and EB significantly (p < 0.05) reduced the total bacte- rial, total coliform and total fungal contamination. A dose of 20 kGy of GR significantly (p < 0.05) reduced the total bacterial and total fungal contamination, while a 20 kGy dose of EB reduced the initial bacterial, total coliform and total fungal contamination to below detection level when the analysis was carried out im- mediately after irradiation treatment or after 12 months of storage. The comparative study demonstrated that electron beam was more effective for decontamination of chamomile powder than gamma irradiation.

The value of tests of cure following cervical chlamydial infection.

PubMed

White, D J; Mann, C H; Matthews, R S; Leeming, J G; Clay, J C

1993-01-01

Test of cure (TOC) was performed 2, 4 and 6 weeks after treatment for cervical chlamydia infection with 10-14 days of Deteclo one tablet twice daily, erythromycin 500 mg twice daily or doxycycline 100 mg twice daily. Testing was by chlamydia culture and IDEIA (DAKO diagnostics Ltd). Discrepant results were subsequently checked by immunofluorescence (Syva MicroTrak) of both sets of left over transport media. Two hundred and three patients attended on at least one occasion; 189, 146 and 107 at 2, 4 and 6 weeks respectively. Of these 127, 70 and 34, respectively, denied sexual intercourse or had consistently used condoms. Fourteen were positive over the study period by either or both methods of detection. Of 8 culture positive results 3 were negative by IDEIA. Two of these had elementary bodies (EBs) on immunofluorescence of both sets of saved transport media. One had EBs on immunofluorescence of the saved culture transport medium only. None of the 6 IDEIA positive, culture negative patients had immunofluorescent EBs in the IDEIA transport media although one had EBs in the saved culture transport medium. One IDEIA suspicious, culture negative patient had EBs in both sets of saved transport media. There was no significant difference in the rate of chlamydia detection from patients admitting to or denying unprotected intercourse. TOC has a low yield in cases of cervical chlamydial infection when there has been careful contact tracing and treatment has been completed. If TOC is performed culture should be used if available and where antigen detection methods are used confirmation should be sought for any positive results.

Microstructural, mechanical and oxidation features of NiCoCrAlY coating produced by plasma activated EB-PVD

NASA Astrophysics Data System (ADS)

He, Jian; Guo, Hongbo; Peng, Hui; Gong, Shengkai

2013-06-01

NiCoCrAlY coatings produced by electron beam-physical vapor deposition (EB-PVD) have been extensively used as the oxidation resistance coatings or suitable bond coats in thermal barrier coating (TBC) system. However, the inherent imperfections caused by EB-PVD process degrade the oxidation resistance of the coatings. In the present work, NiCoCrAlY coatings were creatively produced by plasma activated electron beam-physical vapor deposition (PA EB-PVD). The novel coatings showed a terraced substructure on the surface of each grain due to the increased energy of metal ions and enhanced mobility of adatoms. Also a strong (1 1 1) crystallographic texture of γ/γ' grains was observed. The toughness of the coatings got remarkably improved compared with the coatings deposited by conventional EB-PVD and the oxidation behavior at 1373 K showed that the novel coatings had excellent oxidation resistance. The possible mechanism was finally discussed.

Electron-beam lithography with character projection technique for high-throughput exposure with line-edge quality control

NASA Astrophysics Data System (ADS)

Ikeno, Rimon; Maruyama, Satoshi; Mita, Yoshio; Ikeda, Makoto; Asada, Kunihiro

2016-07-01

The high throughput of character projection (CP) electron-beam (EB) lithography makes it a promising technique for low-to-medium volume device fabrication with regularly arranged layouts, such as for standard-cell logics and memory arrays. However, non-VLSI applications such as MEMS and MOEMS may not be able to fully utilize the benefits of the CP method due to the wide variety of layout figures including curved and oblique edges. In addition, the stepwise shapes that appear because of the EB exposure process often result in intolerable edge roughness, which degrades device performances. In this study, we propose a general EB lithography methodology for such applications utilizing a combination of the CP and variable-shaped beam methods. In the process of layout data conversion with CP character instantiation, several control parameters were optimized to minimize the shot count, improve the edge quality, and enhance the overall device performance. We have demonstrated EB shot reduction and edge-quality improvement with our methodology by using a leading-edge EB exposure tool, ADVANTEST F7000S-VD02, and a high-resolution hydrogen silsesquioxane resist. Atomic force microscope observations were used to analyze the resist edge profiles' quality to determine the influence of the control parameters used in the data conversion process.

Propentofylline treatment on open field behavior in rats with focal ethidium bromide-induced demyelination in the ventral surface of the brainstem.

PubMed

Martins-Júnior, J L; Bernardi, M M; Bondan, E F

2016-03-01

Propentofylline (PPF) is a xanthine derivative with pharmacological effects that are distinct from those of classic methylxanthines. It depresses the activation of microglial cells and astrocytes, which is associated with neuronal damage during neural inflammation and hypoxia. Our previous studies showed that PPF improved remyelination following gliotoxic lesions that were induced by ethidium bromide (EB). In the present study, the long-term effects of PPF on open field behavior in rats with EB-induced focal demyelination were examined. The effects of PPF were first evaluated in naive rats that were not subjected to EB lesions. Behavior in the beam walking test was also evaluated during chronic PPF treatment because impairments in motor coordination can interfere with behavior in the open field. The results showed that PPF treatment in unlesioned rats decreased general activity and caused motor impairment in the beam walking test. Gliotoxic EB injections increased general activity in rats that were treated with PPF compared with rats that received saline solution. Motor incoordination was also attenuated in PPF-treated rats. These results indicate that PPF reversed the effects of EB lesions on behavior in the open field and beam walking test. Copyright © 2016 Elsevier Inc. All rights reserved.

Electron Beam Technology for Environmental Pollution Control.

PubMed

Chmielewski, Andrzej G; Han, Bumsoo

2016-10-01

Worldwide, there are over 1700 electron beam (EB) units in commercial use, providing an estimated added value to numerous products, amounting to 100 billion USD or more. High-current electron accelerators are used in diverse industries to enhance the physical and chemical properties of materials and to reduce undesirable contaminants such as pathogens, toxic byproducts, or emissions. Over the past few decades, EB technologies have been developed aimed at ensuring the safety of gaseous and liquid effluents discharged to the environment. It has been demonstrated that EB technologies for flue gas treatment (SO x and NO x removal), wastewater purification, and sludge hygienization can be effectively deployed to mitigate environmental degradation. Recently, extensive work has been carried out on the use of EB for environmental remediation, which also includes the removal of emerging contaminants such as VOCs, endocrine disrupting chemicals (EDCs), and potential EDCs.

Electron beam welding of aircraft structures. [joining of titanium alloy wing structures on F-14 aircraft

NASA Technical Reports Server (NTRS)

Witt, R. H.

1972-01-01

Requirements for advanced aircraft have led to more extensive use of titanium alloys and the resultant search for joining processes which can produce lightweight, high strength airframe structures efficiently. As a result, electron beam welding has been investigated. The following F-14A components are now being EB welded in production and are mainly annealed Ti-6Al-4V except for the upper wing cover which is annealed Ti-6Al-6V-2Sn: F-14A wing center section box, and F-14A lower and upper wing covers joined to wing pivot fitting assemblies. Criteria for selection of welding processes, the EB welding facility, development work on EB welding titanium alloys, and F-14A production and sliding seal electron beam welding are reported.

Development and installation of an advanced beam guidance system on Viking`s 2.4 megawatt EB furnace

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

Motchenbacher, C.A.; Grosse, I.A.

1994-12-31

Viking Metallurgical is a manufacturer of titanium alloy and superalloy seamless ring forgings for the aerospace industry. For more than 20 years Viking has used electron beam cold hearth melting to recover titanium alloy scrap and to produce commercially pure titanium ingot for direct forging. In the 1970`s Viking pioneered electron beam cold hearth melting and in 1983 added a two-gun, 2.4 MW furnace. As part of Vikings efforts to improve process control we have commissioned and installed a new electron beam guidance system. The system is capable of generating virtually unlimited EB patterns resulting in improved melt control.

Contouring and Constraining Bowel on a Full-Bladder Computed Tomography Scan May Not Reflect Treatment Bowel Position and Dose Certainty in Gynecologic External Beam Radiation Therapy

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

Yaparpalvi, Ravindra, E-mail: ryaparpa@montefiore.org; Mehta, Keyur J.; Bernstein, Michael B.

Purpose: To evaluate, in a gynecologic cancer setting, changes in bowel position, dose-volume parameters, and biological indices that arise between full-bladder (FB) and empty-bladder (EB) treatment situations; and to evaluate, using cone beam computed tomography (CT), the validity of FB treatment presumption. Methods and Materials: Seventeen gynecologic cancer patients were retrospectively analyzed. Empty-bladder and FB CTs were obtained. Full-bladder CTs were used for planning and dose optimization. Patients were given FB instructions for treatment. For the study purpose, bowel was contoured on the EB CTs for all patients. Bowel position and volume changes between FB and EB states were determined.more » Full-bladder plans were applied on EB CTs for determining bowel dose-volume changes in EB state. Biological indices (generalized equivalent uniform dose and normal tissue complication probability) were calculated and compared between FB and EB. Weekly cone beam CT data were available in 6 patients to assess bladder volume at treatment. Results: Average (±SD) planned bladder volume was 299.7 ± 68.5 cm{sup 3}. Median bowel shift in the craniocaudal direction between FB and EB was 12.5 mm (range, 3-30 mm), and corresponding increase in exposed bowel volume was 151.3 cm{sup 3} (range, 74.3-251.4 cm{sup 3}). Absolute bowel volumes receiving 45 Gy were higher for EB compared with FB (mean 328.0 ± 174.8 vs 176.0 ± 87.5 cm{sup 3}; P=.0038). Bowel normal tissue complication probability increased 1.5× to 23.5× when FB planned treatments were applied in the EB state. For the study, the mean percentage value of relative bladder volume at treatment was 32%. Conclusions: Full-bladder planning does not necessarily translate into FB treatments, with a patient tendency toward EB. Given the uncertainty in daily control over bladder volume for treatment, we strongly recommend a “planning-at-risk volume bowel” (PRV{sub B}owel) concept to account for bowel motion between FB and EB that can be tailored for the individual patient.« less

Dosimetric impact of tumor bed delineation variability based on 4DCT scan for external-beam partial breast irradiation.

PubMed

Guo, Bing; Li, Jianbin; Wang, Wei; Li, Fengxiang; Guo, Yanluan; Li, Yankang; Liu, Tonghai

2015-01-01

This study sought to evaluate the dosimetric impact of tumor bed delineation variability (based on clips, seroma or both clips and seroma) during external-beam partial breast irradiation (EB-PBI) planned utilizing four-dimensional computed tomography (4DCT) scans. 4DCT scans of 20 patients with a seroma clarity score (SCS) 3~5 and ≥5 surgical clips were included in this study. The combined volume of the tumor bed formed using clips, seroma, or both clips and seroma on the 10 phases of 4DCT was defined as the internal gross target volume (termed IGTVC, IGTVS and IGTVC+S, respectively). A 1.5-cm margin was added by defining the planning target volume (termed PTVC, PTVS and PTVC+S, respectively). Three treatment plans were established using the 4DCT images (termed EB-PBIC, EB-PBIS, EB-PBIC+S, respectively). The results showed that the volume of IGTVC+S was significantly larger than that of IGTVCand IGTVS. Similarly, the volume of PTVC+S was markedly larger than that of PTVC and PTVS. However, the PTV coverage for EB-PBIC+S was similar to that of EB-PBIC and EB-PBIS, and there were no significant differences in the homogeneity index or conformity index between the three treatment plans (P=0.878, 0.086). The EB-PBIS plan resulted in the lowest ipsilateral normal breast and ipsilateral lung doses compared with the EB-PBIC and EB-PBIC+S plans. To conclude, the volume variability delineated based on clips, seroma or both clips and seroma resulted in dosimetric variability for organs at risk, but did not show a marked influence on the dosimetric distribution.

Dosimetric impact of tumor bed delineation variability based on 4DCT scan for external-beam partial breast irradiation

PubMed Central

Guo, Bing; Li, Jianbin; Wang, Wei; Li, Fengxiang; Guo, Yanluan; Li, Yankang; Liu, Tonghai

2015-01-01

This study sought to evaluate the dosimetric impact of tumor bed delineation variability (based on clips, seroma or both clips and seroma) during external-beam partial breast irradiation (EB-PBI) planned utilizing four-dimensional computed tomography (4DCT) scans. 4DCT scans of 20 patients with a seroma clarity score (SCS) 3~5 and ≥5 surgical clips were included in this study. The combined volume of the tumor bed formed using clips, seroma, or both clips and seroma on the 10 phases of 4DCT was defined as the internal gross target volume (termed IGTVC, IGTVS and IGTVC+S, respectively). A 1.5-cm margin was added by defining the planning target volume (termed PTVC, PTVS and PTVC+S, respectively). Three treatment plans were established using the 4DCT images (termed EB-PBIC, EB-PBIS, EB-PBIC+S, respectively). The results showed that the volume of IGTVC+S was significantly larger than that of IGTVCand IGTVS. Similarly, the volume of PTVC+S was markedly larger than that of PTVC and PTVS. However, the PTV coverage for EB-PBIC+S was similar to that of EB-PBIC and EB-PBIS, and there were no significant differences in the homogeneity index or conformity index between the three treatment plans (P=0.878, 0.086). The EB-PBIS plan resulted in the lowest ipsilateral normal breast and ipsilateral lung doses compared with the EB-PBIC and EB-PBIC+S plans. To conclude, the volume variability delineated based on clips, seroma or both clips and seroma resulted in dosimetric variability for organs at risk, but did not show a marked influence on the dosimetric distribution. PMID:26885108

Evaluation of fatigue crack behavior in electron beam irradiated polyethylene pipes

NASA Astrophysics Data System (ADS)

Pokharel, Pashupati; Jian, Wei; Choi, Sunwoong

2016-09-01

A cracked round bar (CRB) fatigue test was employed to determine the slow crack growth (SCG) behavior of samples from high density polyethylene (HDPE) pipes using PE4710 resin. The structure property relationships of fatigue failure of polyethylene CRB specimens which have undergone various degree of electron beam (EB) irradiation were investigated by observing fatigue failure strength and the corresponding fracture surface morphology. Tensile test of these HDPE specimens showed improvements in modulus and yield strength while the failure strain decreased with increasing EB irradiation. The CRB fatigue test of HDPE pipe showed remarkable effect of EB irradiation on number of cycles to failure. The slopes of the stress-cycles to failure curve were similar for 0-100 kGy; however, significantly higher slope was observed for 500 kGy EB irradiated pipe. Also, the cycle to fatigue failure was seen to decrease as with EB irradiation in the high stress range, ∆σ=(16 MPa to 10.8 MPa); however, 500 kGy EB irradiated samples showed longer cycles to failure than the un-irradiated specimens at the stress range below 9.9 MPa and the corresponding initial stress intensity factor (∆KI,0)=0.712 MPa m1/2. The fracture surface morphology indicated that the cross-linked network in 500 kGy EB irradiated PE pipe can endure low dynamic load more effectively than the parent pipe.

Electron Beam-Cure Polymer Matrix Composites: Processing and Properties

NASA Technical Reports Server (NTRS)

Wrenn, G.; Frame, B.; Jensen, B.; Nettles, A.

2001-01-01

Researchers from NASA and Oak Ridge National Laboratory are evaluating a series of electron beam curable composites for application in reusable launch vehicle airframe and propulsion systems. Objectives are to develop electron beam curable composites that are useful at cryogenic to elevated temperatures (-217 C to 200 C), validate key mechanical properties of these composites, and demonstrate cost-saving fabrication methods at the subcomponent level. Electron beam curing of polymer matrix composites is an enabling capability for production of aerospace structures in a non-autoclave process. Payoffs of this technology will be fabrication of composite structures at room temperature, reduced tooling cost and cure time, and improvements in component durability. This presentation covers the results of material property evaluations for electron beam-cured composites made with either unidirectional tape or woven fabric architectures. Resin systems have been evaluated for performance in ambient, cryogenic, and elevated temperature conditions. Results for electron beam composites and similar composites cured in conventional processes are reviewed for comparison. Fabrication demonstrations were also performed for electron beam-cured composite airframe and propulsion piping subcomponents. These parts have been built to validate manufacturing methods with electron beam composite materials, to evaluate electron beam curing processing parameters, and to demonstrate lightweight, low-cost tooling options.

Comparison of electron beam and laser beam powder bed fusion additive manufacturing process for high temperature turbine component materials

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

Dryepondt, Sebastien N; Pint, Bruce A; Ryan, Daniel

2016-04-01

The evolving 3D printer technology is now at the point where some turbine components could be additive manufactured (AM) for both development and production purposes. However, this will require a significant evaluation program to qualify the process and components to meet current design and quality standards. The goal of the project was to begin characterization of the microstructure and mechanical properties of Nickel Alloy X (Ni-22Cr-18Fe-9Mo) test bars fabricated by powder bed fusion (PBF) AM processes that use either an electron beam (EB) or laser beam (LB) power source. The AM materials produced with the EB and LB processes displayedmore » significant differences in microstructure and resultant mechanical properties. Accordingly, during the design analysis of AM turbine components, the specific mechanical behavior of the material produced with the selected AM process should be considered. Comparison of the mechanical properties of both the EB and LB materials to those of conventionally processed Nickel Alloy X materials indicates the subject AM materials are viable alternatives for manufacture of some turbine components.« less

Degradation and decoloration of textiles wastewater by electron beam irradiation: Effect of energy, current and absorbed dose

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

Bakar, Khomsaton Abu; Zulkafli,; Hashim, Siti A'aisah

2014-09-03

In this study, electron beam accelerator (EB) was used to treat textiles wastewater from Rawang Industrial Park, Selangor. The objectives were to determine effective energy, beam current and absorbed dose required for decoloration and degradation of the textiles effluent. The textiles effluent was irradiated in a batch with various energy of 1MeV to 3MeV at constant beam current of 30mA. It was observed that removal of color and COD increases with higher beam energy. The EB energy of 1MeV effectively to removed 58% color and 19% COD. For textile effluent sample irradiated at fix energy of 1MeV and 3Mev butmore » at different beam current 10mA, 20mA and 30mA. It was observed that removal of color and COD increases with the increased of beam current at each energy. However removal of color was significantly better at 1Mev as compared to 3Mev. In the case of textiles effluent, irradiated at doses of 17, 20,25,30, 35, 100 and 200kGy using 30 kW power of EB (1Mev, 30mA), results shows removal of BOD{sub 5}, COD and color were in the range 9%-33%, 14%-38% and 43%-78% respectively.« less

Effect of electron beam irradiation on the properties of crosslinked rubbers

NASA Astrophysics Data System (ADS)

Banik, Indranil; Bhowmick, Anil K.

2000-05-01

Influence of electron beam (EB) irradiation on the mechanical and dynamic mechanical properties of crosslinked fluorocarbon (FKM) rubber, natural rubber (NR), ethylene propylene diene monomer (EPDM) rubber and nitrile rubber (NBR) has been investigated. The modulus, gel fraction, glass transition temperature ( Tg) and storage modulus increased, while the elongation at the break and the loss tangent (tan δ) Tg decreased. FKM and NBR vulcanizates have been shown to have EB radiation resistance up to 1500 kGy.

Electron Beam Cured Epoxy Resin Composites for High Temperature Applications

NASA Technical Reports Server (NTRS)

Janke, Christopher J.; Dorsey, George F.; Havens, Stephen J.; Lopata, Vincent J.; Meador, Michael A.

1997-01-01

Electron beam curing of Polymer Matrix Composites (PMC's) is a nonthermal, nonautoclave curing process that has been demonstrated to be a cost effective and advantageous alternative to conventional thermal curing. Advantages of electron beam curing include: reduced manufacturing costs; significantly reduced curing times; improvements in part quality and performance; reduced environmental and health concerns; and improvement in material handling. In 1994 a Cooperative Research and Development Agreement (CRADA), sponsored by the Department of Energy Defense Programs and 10 industrial partners, was established to advance the electron beam curing of PMC technology. Over the last several years a significant amount of effort within the CRADA has been devoted to the development and optimization of resin systems and PMCs that match the performance of thermal cured composites. This highly successful materials development effort has resulted in a board family of high performance, electron beam curable cationic epoxy resin systems possessing a wide range of excellent processing and property profiles. Hundreds of resin systems, both toughened and untoughened, offering unlimited formulation and processing flexibility have been developed and evaluated in the CRADA program.

Estimation of resist sensitivity for extreme ultraviolet lithography using an electron beam

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

Oyama, Tomoko Gowa, E-mail: ohyama.tomoko@qst.go.jp; Oshima, Akihiro; Tagawa, Seiichi, E-mail: tagawa@sanken.osaka-u.ac.jp

2016-08-15

It is a challenge to obtain sufficient extreme ultraviolet (EUV) exposure time for fundamental research on developing a new class of high sensitivity resists for extreme ultraviolet lithography (EUVL) because there are few EUV exposure tools that are very expensive. In this paper, we introduce an easy method for predicting EUV resist sensitivity by using conventional electron beam (EB) sources. If the chemical reactions induced by two ionizing sources (EB and EUV) are the same, the required absorbed energies corresponding to each required exposure dose (sensitivity) for the EB and EUV would be almost equivalent. Based on this theory, wemore » calculated the resist sensitivities for the EUV/soft X-ray region. The estimated sensitivities were found to be comparable to the experimentally obtained sensitivities. It was concluded that EB is a very useful exposure tool that accelerates the development of new resists and sensitivity enhancement processes for 13.5 nm EUVL and 6.x nm beyond-EUVL (BEUVL).« less

Leakage conduction behavior in electron-beam-cured nanoporous silicate films

NASA Astrophysics Data System (ADS)

Liu, Po-Tsun; Tsai, T. M.; Chang, T. C.

2005-05-01

This letter explores the application of electron-beam curing on nanoporous silicate films. The electrical conduction mechanism for the nanoporous silicate film cured by electron-beam radiation has been studied with metal-insulator-semiconductor capacitors. Electrical analyses over a varying temperature range from room temperature to 150°C provide evidence for space-charge-limited conduction in the electron-beam-cured thin film, while Schottky-emission-type leaky behavior is seen in the counterpart typically cured by a thermal furnace. A physical model consistent with electrical analyses is also proposed to deduce the origin of conduction behavior in the nanoporous silicate thin film.

A comparison of the physics of Gas Tungsten Arc Welding (GTAW), Electron Beam Welding (EBW), and Laser Beam Welding (LBW)

NASA Technical Reports Server (NTRS)

Nunes, A. C., Jr.

1985-01-01

The physics governing the applicability and limitations of gas tungsten arc (GTA), electron beam (EB), and laser beam (LB) welding are compared. An appendix on the selection of laser welding systems is included.

E-beam direct write is free

NASA Astrophysics Data System (ADS)

Glasser, Lance A.

2007-10-01

In this paper we discuss four business concepts that will impact the adoption of e-beam direct write (EbDW). They are: (1) The economically advantageous region for EbDW. At what costs and volumes EbDW is economically advantageous is controlled by a two-sided constraint involving the cost of reticles on one hand and the cost of design on the other. (2) The important role of product derivatives and other markets that can be satisfied by designs with heavy IP reuse. The natural long tail in demand for differentiated products is today chopped off by the high costs of reticles. We show data on the elasticity of the product derivative market with respect to certain costs. (3) That because reticle prices typically decline at a 30% per year for the first few years after a new node is introduced, delaying the fabrication of that first reticle set for a new product can save millions, more than paying for EbDW. The applicability of this technique is, however, limited by the need for product requalifaction. (4) Finally, we introduce the business concept of the virtual reticle as a possible component in EbDW pricing.

EB welding of launch vehicles

NASA Astrophysics Data System (ADS)

Szabo, Attila

While large structural components can be electron beam (EB) welded, equipment and operating costs increase with the requisite vacuum chamber's size. Attention is presently given to cost-effective ways of EB welding launch-vehicle assemblies without compromise of weld quality in such alloys as 2219, 2090, Weldalite, and HP9-4-30/20. Weld strengths at both room and cryogenic temperatures that were 50 percent higher than those obtainable for such materials with arc welding have been demonstrated. Fracture toughnesses were also 40-50 percent higher than arc-welded values. Attention is given to EB joint fit-up allowables for 2219-T87 Al alloy.

Post-image acquisition processing approaches for coherent backscatter validation

NASA Astrophysics Data System (ADS)

Smith, Christopher A.; Belichki, Sara B.; Coffaro, Joseph T.; Panich, Michael G.; Andrews, Larry C.; Phillips, Ronald L.

2014-10-01

Utilizing a retro-reflector from a target point, the reflected irradiance of a laser beam traveling back toward the transmitting point contains a peak point of intensity known as the enhanced backscatter (EBS) phenomenon. EBS is dependent on the strength regime of turbulence currently occurring within the atmosphere as the beam propagates across and back. In order to capture and analyze this phenomenon so that it may be compared to theory, an imaging system is integrated into the optical set up. With proper imaging established, we are able to implement various post-image acquisition techniques to help determine detection and positioning of EBS which can then be validated with theory by inspection of certain dependent meteorological parameters such as the refractive index structure parameter, Cn2 and wind speed.

Final product analysis in the e-beam and gamma radiolysis of aqueous solutions of metoprolol tartrate

NASA Astrophysics Data System (ADS)

Slegers, Catherine; Tilquin, Bernard

2006-09-01

The radiostability of metoprolol tartrate aqueous solutions and the influence of the absorbed dose (0-50 kGy), dose rate (e-beam (EB) vs. gamma ( γ)) and radioprotectors (pharmaceutical excipients) are investigated by HPLC-UV analyses and through computer simulations. The use of radioprotecting excipients is more promising than an increase in the dose rate to lower the degradation of metoprolol tartrate aqueous solutions for applications such as radiosterilization. The decontamination of metoprolol tartrate from waste waters by EB processing appears highly feasible.

Operation of the CESR-TA vertical beam size monitor at Eb = 4 GeV

NASA Astrophysics Data System (ADS)

Alexander, J. P.; Conolly, C.; Edwards, E.; Flanagan, J. W.; Fontes, E.; Heltsley, B. K.; Lyndaker, A.; Peterson, D. P.; Rider, N. T.; Rubin, D. L.; Seeley, R.; Shanks, J.

2015-10-01

We describe operation of the CESR-TA vertical beam size monitor (xBSM) with e± beams with Eb=4 GeV. The xBSM measures vertical beam size by imaging synchrotron radiation x-rays through an optical element onto a detector array of 32 InGaAs photodiodes with 50 μm pitch. The device has previously been successfully used to measure vertical beam sizes of 10-100 μm on a bunch-by-bunch, turn-by-turn basis at e± beam energies of ~2 GeV and source magnetic fields below 2.8 kG, for which the detector required calibration for incident x-rays of 1-5 keV. At Eb = 4.0 GeV and B=4.5 kG, however, the incident synchrotron radiation spectrum extends to ~20 keV, requiring calibration of detector response in that regime. Such a calibration is described and then used to analyze data taken with several different thicknesses of filters in front of the detector. We obtain a relative precision of better than 4% on beam size measurement from 15 to 100 μm over several different ranges of x-ray energy, including both 1-12 keV and 6-17 keV. The response of an identical detector, but tilted vertically by 60° in order to increase magnification without a longer beamline, is measured and shown to improve x-ray detection above 4 keV without compromising sensitivity to beam size. We also investigate operation of a coded aperture using gold masking backed by synthetic diamond.

Characterization of the Microstructures and the Cryogenic Mechanical Properties of Electron Beam Welded Inconel 718

NASA Astrophysics Data System (ADS)

Kwon, Soon Il; Bae, Sang Hyun; Do, Jeong Hyeon; Jo, Chang Yong; Hong, Hyun Uk

2016-02-01

The microstructures and the cryogenic mechanical properties of electron beam (EB) welds between cast and forged Inconel 718 superalloys with a thickness of 10 mm were investigated in comparison with gas tungsten arc (GTA) welds. EB welding with a heat input lower than 250 J/mm caused the formation of liquation microfissuring in the cast-side heat-affected-zone (HAZ) of the EB welds. HAZ liquation microfissuring appeared to be associated with the constitutional liquation of primary NbC carbides at the grain boundaries. Compared with the GTA welding process, the EB welding produced welds with superior microstructure, exhibiting fine dendritic structure associated with the reduction in size and fraction of the Laves phase due to the rapid cooling rate. This result was responsible for the superior mechanical properties of the EB welds at 77 K (-196 °C). Laves particles in both welds were found to provide the preferential site for the crack initiation and propagation, leading to a significant decrease in the Charpy impact toughness at 77 K (-196 °C). Crack initiation and propagation induced by Charpy impact testing were discussed in terms of the dendrite arm spacing, the Laves size and the dislocation structure ahead of the crack arisen from the fractured Laves phase in the two welds.

Electron beam for preservation of biodeteriorated cultural heritage paper-based objects

NASA Astrophysics Data System (ADS)

Chmielewska-Śmietanko, Dagmara; Gryczka, Urszula; Migdał, Wojciech; Kopeć, Kamil

2018-02-01

Unsuitable storage conditions or accidents such as floods can present a serious threat for large quantities of book making them prone to attack by harmful microorganisms. The microbiological degradation of archives and book collections can be efficiently inhibited with irradiation processing. Application of EB irradiation to book and archive collections can also be a very effective alternative to the commonly used ethylene oxide treatment, which is toxic to the human and natural environment. In this study was evaluated the influence of EB irradiation used for microbiological decontamination process on paper-based objects. Three different kinds of paper (Whatman CHR 1, office paper and newsprint paper) were treated with 0.4, 1, 2, 5, 10 and 25 kGy electron beam irradiation. Optical and mechanical properties of different sorts of paper treated with e-beam, before and after the radiation process were studied. These results, which correlated with absorbed radiation doses effective for the elimination of Aspergillus niger (A. niger) allowed to determine that EB irradiation with absorbed radiation dose of 5 kGy ensures safe decontamination of different sorts of paper-based objects.

Impurity segregation behavior in polycrystalline silicon ingot grown with variation of electron-beam power

NASA Astrophysics Data System (ADS)

Lee, Jun-Kyu; Lee, Jin-Seok; Jang, Bo-Yun; Kim, Joon-Soo; Ahn, Young-Soo; Cho, Churl-Hee

2014-08-01

Electron beam melting (EBM) systems have been used to improve the purity of metallurgical grade silicon feedstock for photovoltaic application. Our advanced EBM system is able to effectively remove volatile impurities using a heat source with high energy from an electron gun and to continuously allow impurities to segregate at the top of an ingot solidified in a directional solidification (DS) zone in a vacuum chamber. Heat in the silicon melt should move toward the ingot bottom for the desired DS. However, heat flux though the ingot is changed as the ingot becomes longer due to low thermal conductivity of silicon. This causes a non-uniform microstructure of the ingot, finally leading to impurity segregation at its middle. In this research, EB power irradiated on the silicon melt was controlled during the ingot growth in order to suppress the change of heat flux. EB power was reduced from 12 to 6.6 kW during the growth period of 45 min with a drop rate of 0.125 kW/min. Also, the silicon ingot was grown under a constant EB power of 12 kW to estimate the effect of the drop rate of EB power. When the EB power was reduced, the grains with columnar shape were much larger at the middle of the ingot compared to the case of constant EB power. Also, the present research reports a possible reason for the improvement of ingot purity by considering heat flux behaviors.

The radiation crosslinking process and new products

NASA Astrophysics Data System (ADS)

Ueno, Keiji

In 1988 there were over 90 EB accelerators for industrial use in Japan. The number one industrial application was Wire and Cable, the 2nd was PE foam and Curing, and the 3rd was Precure of tyre. R & D has a very high ration of EB accelerator use. Low energy industrial applications were coated steel (white board), plaster slab, coated paper, magnetic tape and floppy disks. As a new application of the radiation crosslinking process, we have studied radiation crosslinking of engineering plastics and succeeded in improving the hea tresistivity without using glass fibers. Many kinds of polyfunctional monomers used as crosslinking reagents of irradiated Nylon and PBT were studied.

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

Tan, Yi, E-mail: tanyi@dlut.edu.cn; You, Xiaogang; You, Qifan

Electron beam smelting (EBS) has been used to fabricate the Inconel 740 superalloy. Microstructures, hardness, and deformation characteristics of the alloy are studied. It is observed that carbides and fine secondary phase nuclei are distributed in the hot worked EBS 740 superalloy. The Ostwald ripening occurs during solution treatment and leads to aggregation of the γ′ precipitates, the size of γ′ precipitates varies from several nanometers to more than one hundred nanometers as a result. The average size of the secondary phase is < 30 nm after aging treatment and the average Vickers hardness is measured to be about 370.more » The critical shear stress is calculated to be 0.627 GPa with governing mechanism of shearing, causing a stronger strengthening effect than the traditionally prepared Inconel 740 superalloy. The compression behavior indicates that the EBS 740 superalloy shows higher flow stress than 740H at low Zener-Hollomon parameter, which may arise from the undissolved γ′ precipitates and higher activation energy Q. The tensile results show that the fracture surface exhibits a ductile fracture pattern, in contrast to no obvious plastic deformation on the macroscopic fracture. Crack propagation proceeds in a transgranular fracture mode with facets and voids presented on the fracture surface. - Graphical abstract: Electron beam smelting (EBS) has been used to fabricate the Inconel 740 superalloy. Microstructures, hardness, and deformation characteristics of the alloy are studied. The average size of the secondary phase is < 30 nm after aging treatment and the average Vickers hardness is measured to be about 370. The critical shear stress is calculated to be 0.627 GPa with governing mechanism of shearing, causing a stronger strengthening effect than the traditionally prepared Inconel 740 superalloy. The EBS 740 superalloy shows higher flow stress than 740H at low Zener-Hollomon parameter, which may arise from the undissolved γ′ precipitates and higher activation energy Q. The EBS technology shows encouraging potential in preparation of nickel-based superalloys. Morphologies of γ′ precipitates and Vickers hardness as well as hot compression curves for electron beam smelting 740 superalloy. - Highlights: • Electron beam smelting, a novel method, was used to prepare the Inconel 740 superalloy. • The average size of the γ′ precipitates after aging treatment is < 30 nm. • The shearing mode generates a stronger strengthening effect than the traditional 740. • At low Zener-Hollomon parameter, the EBS 740 shows higher flow stress than 740H.« less

Inedible cellulose-based biomass resist material amenable to water-based processing for use in electron beam lithography

NASA Astrophysics Data System (ADS)

Takei, Satoshi; Maki, Hirotaka; Sugahara, Kigen; Ito, Kenta; Hanabata, Makoto

2015-07-01

An electron beam (EB) lithography method using inedible cellulose-based resist material derived from woody biomass has been successfully developed. This method allows the use of pure water in the development process instead of the conventionally used tetramethylammonium hydroxide and anisole. The inedible cellulose-based biomass resist material, as an alternative to alpha-linked disaccharides in sugar derivatives that compete with food supplies, was developed by replacing the hydroxyl groups in the beta-linked disaccharides with EB-sensitive 2-methacryloyloxyethyl groups. A 75 nm line and space pattern at an exposure dose of 19 μC/cm2, a resist thickness uniformity of less than 0.4 nm on a 200 mm wafer, and low film thickness shrinkage under EB irradiation were achieved with this inedible cellulose-based biomass resist material using a water-based development process.

Electron Beam Brazing of Titanium for Construction in Space

NASA Technical Reports Server (NTRS)

Flom, Yury

2006-01-01

An extended presence of humans in space requires an in-situ capability to construct various permanent structures to support scientific research, power generation, communication, radiation shielding and other functions. Electron Beam (EB) vacuum brazing has been identified as one of the best joining processes for in-space joining, particular for making a large quantity of permanent joints as required for construction of the sizeable truss structures. Thin wall titanium tubes are perhaps the best choice because of their high stiffness, excellent strength-to-weight ratio and great metal forming and joining ability. An innovative EB vacuum spot brazing process is being developed at Goddard Space Flight Center to be used for robotic as well as human-assisted construction in space. This paper describes experimental results obtained during the initial effort of EB brazing of titanium tubes with the special emphasis on low temperature aluminum filler metals.

A newly discovered bacterium associated with parthenogenesis and a change in host selection behavior in parasitoid wasps.

PubMed

Zchori-Fein, E; Gottlieb, Y; Kelly, S E; Brown, J K; Wilson, J M; Karr, T L; Hunter, M S

2001-10-23

The symbiotic bacterium Wolbachia pipientis has been considered unique in its ability to cause multiple reproductive anomalies in its arthropod hosts. Here we report that an undescribed bacterium is vertically transmitted and associated with thelytokous parthenogenetic reproduction in Encarsia, a genus of parasitoid wasps. Although Wolbachia was found in only one of seven parthenogenetic Encarsia populations examined, the "Encarsia bacterium" (EB) was found in the other six. Among seven sexually reproducing populations screened, EB was present in one, and none harbored Wolbachia. Antibiotic treatment did not induce male production in Encarsia pergandiella but changed the oviposition behavior of females. Cured females accepted one host type at the same rate as control females but parasitized significantly fewer of the other host type. Phylogenetic analysis based on the 16S rDNA gene sequence places the EB in a unique clade within the Cytophaga-Flexibacter-Bacteroid group and shows EB is unrelated to the Proteobacteria, where Wolbachia and most other insect symbionts are found. These results imply evolution of the induction of parthenogenesis in a lineage other than Wolbachia. Importantly, these results also suggest that EB may modify the behavior of its wasp carrier in a way that enhances its transmission.

Application of nonlocal models to nano beams. Part II: Thickness length scale effect.

PubMed

Kim, Jun-Sik

2014-10-01

Applicability of nonlocal models to nano-beams is discussed in terms of the Eringen's nonlocal Euler-Bernoulli (EB) beam model. In literature, most work has taken the axial coordinate derivative in the Laplacian operator presented in nonlocal elasticity. This causes that the non-locality always makes the beam soften as compared to the local counterpart. In this paper, the thickness scale effect is solely considered to investigate if the nonlocal model can simulate stiffening effect. Taking the thickness derivative in the Laplacian operator leads to the presence of a surface stress state. The governing equation derived is compared to that of the EB model with the surface stress. The results obtained reveal that the nonlocality tends to decrease the bending moment stiffness whereas to increase the bending rigidity in the governing equation. This tendency also depends on the surface conditions.

The Precipitation Behavior and Hot Deformation Characteristics of Electron Beam Smelted Inconel 740 Superalloy

NASA Astrophysics Data System (ADS)

You, Xiaogang; Tan, Yi; Wu, Chang; You, Qifan; Zhao, Longhai; Li, Jiayan

2018-03-01

The Inconel 740 superalloy was prepared by the electron beam smelting (EBS) technology, the precipitation behavior and strengthening mechanism were studied, and the hot deformation characteristics of EBS 740 superalloy were investigated. The results indicate that the EBS 740 superalloy is mainly strengthened by the mechanism of weakly coupled dislocation shearing, and the resulting critical shear stress is calculated to be 234.6 MPa. The deformation parameters show a great influence on the flow behavior of EBS 740 superalloy. The strain rate sensitivity exponent increases with the increasing of deformation temperature, and the strain hardening exponent shows a decreasing trend with the increasing of strain. The activation energy of EBS 740 above 800 °C is measured to be 408.43 kJ/mol, which is higher than the 740H superalloy. A hyperbolic-sine-type relationship can be observed between the peak stress and Zener-Hollomon parameter. Nevertheless, the influence of deformation parameters is found to be considerably different at temperatures below and above 800 °C. The size of dynamic recrystallization (DRX) grains decreases with the increasing of strain rate when the strain rate is lower than 1/s, and reverse law can be found at higher strain rate. As a result, a piecewise function is established between the DRX grain size and hot working parameters.

Preparation and characterization of nanostructured Pt/TiO2 thin films treated using electron beam.

PubMed

Shin, Joong-Hyeok; Woo, Hee-Gweon; Kim, Bo-Hye; Lee, Byung Cheol; Jun, Jin

2010-05-01

Pt nanoparticle-doped titanium dioxide (Pt/TiO2) thin films were prepared on a silicon wafer substrate by sol-gel spin coating process. The prepared thin films were treated with electron beam (EB at 1.1 MeV, 100, 200, 300 kGy) at air atmosphere. The effect of EB-irradiation on the composition of the treated thin films, optical properties and morphology of thin films were investigated by various analytical techniques such as X-ray photoelectron spectroscopy (XPS), spectroscopic ellipsometry (SE), X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The crystal structure of the TiO2 layer was found to be an anatase phase and the size of TiO2 particles was determined to be about 13 nm. Pt nanoparticles with diameter of 5 nm were observed on surface of the films. A new layer (presumed to be Pt-Ti complex and/or PtO2 compound) was created in the Pt/TiO2 thin film treated with EB (300 kGy). The transmittance of thin film decreased with EB treatment whereas the refractive index increased.

A hybrid plasma-chemical system for high-NOx flue gas treatment

NASA Astrophysics Data System (ADS)

Chmielewski, Andrzej G.; Zwolińska, Ewa; Licki, Janusz; Sun, Yongxia; Zimek, Zbigniew; Bułka, Sylwester

2018-03-01

The reduction of high concentrations of NOx and SO2 from simulated flue gas has been studied. Our aim was to optimise energy consumption for NOx and SO2 removal from off-gases from a diesel generator using heavy fuel oil. A hybrid process: electron beam (EB) plasma and wet scrubber has been applied. A much higher efficiency of NOx and SO2 removal was achieved in comparison to dry, ammonia free, electron beam flue gas treatment (EBFGT). A recorded removal from a concentration of 1500 ppm NOx reached 49% at a low dose of 6.5 kGy, while only 2% NOx was removed at the same dose if EB only was applied. For SO2, removal efficiency at a dose of 6.5 kGy increased from 15% (EB only) to 84% when sea water was used as a wet scrubber agent for 700 ppm SO2. The results of this study indicate that EB combined with wet scrubber is a very promising technology to be applied for removal of high concentrations of NOx and SO2 emitted from diesel engines operated e.g. on cargo ships, which are the main sources of SO2 and NOx pollution along their navigation routes.

Ionizing radiation post-curing of objects produced by stereolithography and other methods

DOEpatents

Howell, David H.; Eberle, Claude C.; Janke, Christopher J.

2000-01-01

An object comprised of a curable material and formed by stereolithography or another three-dimensional prototyping method, in which the object has undergone initial curing, is subjected to post-curing by ionizing radiation, such as an electron beam having a predetermined beam output energy, which is applied in a predetermined dosage and at a predetermined dose rate. The post-cured object exhibits a property profile which is superior to that which existed prior to the ionizing radiation post-curing.

Nanosilicon dot arrays with a bit pitch and a track pitch of 25 nm formed by electron-beam drawing and reactive ion etching for 1 Tbit/in.{sup 2} storage

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

Hosaka, Sumio; Sano, Hirotaka; Shirai, Masumi

2006-11-27

The formation of very fine Si dots with a bit pitch and a track pitch of less than 25 nm using electron-beam (EB) lithography on ZEP520 and calixarene EB resists and CF{sub 4} reactive ion etching has been demonstrated. The experimental results indicate that the calixarene resist is very suitable for forming an ultrahigh-packed bit array pattern of Si dots. This result promises to open the way toward 1 Tbit/in.{sup 2} storage using patterned media with a dot size of <15 nm.

Standard-M mobile satellite terminal employing electronic beam squint tracking

NASA Technical Reports Server (NTRS)

Hawkins, G. J.; Beach, M. A.; Hilton, G. S.

1990-01-01

In recent years, extensive experience has been built up at the University of Bristol in the use of the Electronic Beam Squint (EBS) tracking technique, applied to large earth station facilities. The current interest in land mobile satellite terminals, using small tracking antennas, has prompted the investigation of the applicability of the EBS technique to this environment. The development of an L-band mechanically steered vehicle antenna is presented. A description of the antenna is followed by a detailed investigation of the tracking environment and its implications on the error detection capability of the system. Finally, the overall hardware configuration is described along with plans for future work.

High-sensitivity green resist material with organic solvent-free spin-coating and tetramethylammonium hydroxide-free water-developable processes for EB and EUV lithography

NASA Astrophysics Data System (ADS)

Takei, Satoshi; Hanabata, Makoto; Oshima, Akihiro; Kashiwakura, Miki; Kozawa, Takahiro; Tagawa, Seiichi

2015-03-01

We investigated the eco-friendly electron beam (EB) and extreme-ultraviolet (EUV) lithography using a high-sensitive negative type of green resist material derived from biomass to take advantage of organic solvent-free water spin-coating and tetramethylammonium hydroxide(TMAH)-free water-developable techniques. A water developable, non-chemically amplified, high sensitive, and negative tone resist material in EB lithography was developed for environmental affair, safety, easiness of handling, and health of the working people, instead of the common developable process of TMAH. The material design concept to use the water-soluble resist material with acceptable properties such as pillar patterns with less than 100 nm in high EB sensitivity of 10 μC/cm2 and etch selectivity with a silicon-based middle layer in CF4 plasma treatment was demonstrated for EB and EUV lithography.

Decomposition of 2,4-dichlorophenoxyacetic acid by ozonation, ionizing radiation as well as ozonation combined with ionizing radiation

NASA Astrophysics Data System (ADS)

Drzewicz, Przemyslaw; Trojanowicz, Marek; Zona, Robert; Solar, Sonja; Gehringer, Peter

2004-03-01

Electron beam (EB), ozone (O 3) and the combination EB/O 3 were used to study the oxidative decomposition of 2,4-dichlorophenoxyacetic acid (2,4-D) in local tap water. Using an EB treatment, a dose of 10 kGy was required for complete 2,4-D degradation, and a 90% conversion of organic chlorine into chloride ions. Using additionally 1.33 mmol dm -3 O 3 during irradiation, the same result was achieved with a dose of 2.7 kGy. The yields of products acetate and formate were almost doubled by the combined EB/O 3 treatment, compared to those obtained with the same dose by EB irradiation. Gamma radiolysis showed that the degradation dose was proportional to the initial concentration of 2,4-D in the range of 50-2260 μmol dm -3.

Bismaleimide and cyanate ester based sequential interpenetrating polymer networks for high temperature application

NASA Astrophysics Data System (ADS)

Geng, Xing

2005-07-01

A research area of high activity in connection with aerospace engineering has been the development of polymer thermosetting resins that can withstand temperature as high as 300°C while maintaining adequate toughness and providing ease of processing to enable low temperature and low cost composite fabrication methods. In order to meet such requirements, sequential interpenetrating polymer networks (IPNs) based on bismaleimide (BMI) and cyanate ester (CE) monomers were investigated. In these systems, a polycyanurate network is first formed in the presence of BMI and appropriate reactive diluent monomers and, in a second step, a network based on the BMI is created in the presence of a fully formed polycyanurate network. The materials developed can be processed at relatively low temperature (<150°C) and with the aid of electron beam (EB) curing. Of major importance to the success of this work was the identification of a reactive diluent that improves ease of processing and has tailored reactivity to allow for the controlled synthesis of CE-BMI sequential IPNs. Based on solubility and reactivity of a number of reactive diluents, N-acryloylmorpholine (AMP) was selected as a co-monomer for BMI copolymerization. A donor-acceptor reaction mechanism was suggested to explain the relative reactivity of a variety of reactive diluents towards maleimide functionality. The optimum processing parameters for the formation of the first network were determined through the study of metal catalyzed cure and hydrolysis of cyanate esters, whereas the reaction behavior for second network formation in terms of the influence of EB dose rate and temperature was elucidated through an in-situ kinetics study of maleimide and AMP copolymerization. Structure-property relationships were developed which allowed for the design of improved resin systems. In particular, an appropriate network coupler possessing cyanate ester and maleimide functionality was synthesized to link the polycyanurate first network to the BMI/AMP second network and thus form linked sequential IPNs (LIPNs). Consequently, Tg as high as 370°C was achieved and a fracture toughness of 120 J/m2 was obtained for resin systems that possess adequately low viscosity for processing using liquid molding techniques at low temperature.

Eco-friendly electron beam lithography using water-developable resist material derived from biomass

NASA Astrophysics Data System (ADS)

Takei, Satoshi; Oshima, Akihiro; Wakabayashi, Takanori; Kozawa, Takahiro; Tagawa, Seiichi

2012-07-01

We investigated the eco-friendly electron beam (EB) lithography using a high-sensitive negative type of water-developable resist material derived from biomass on hardmask layer for tri-layer processes. A water developable, non-chemically amplified, high sensitive, and negative tone resist material in EB lithography was developed for environmental affair, safety, easiness of handling, and health of the working people, instead of the common developable process of trimethylphenylammonium hydroxide. The images of 200 nm line and 800 nm space pattern with exposure dose of 7.0 μC/cm2 and CF4 etching selectivity of 2.2 with hardmask layer were provided by specific process conditions.

Electron beam surface modifications in reinforcing and recycling of polymers

NASA Astrophysics Data System (ADS)

Czvikovszky, T.; Hargitai, H.

1997-08-01

Thermoplastic polymers can be fiber-reinforced in the recycling step through a reactive modification of the interface between the polymer matrix and fiber. Recollected automobile bumpers made of polypropylene copolymers have been reinforced during the reprocessing with eight different types of high-strength fibers, with waste cord-yarns of the tire industry. A thin layer reactive interface of acrylic oligomers has been applied and activated through low energy (175 keV) electron beam (EB). The upcycling (upgrading recycling) resulted in a series of extrudable and injection-mouldable, fiber-reinforced thermoplastic of enhanced bending strength, increased modulus of elasticity and acceptable impact strength. EB treatment has been compared with conventional methods.

Mehanical Properties of Electron Beam Welded Joints in Thick Gage CA6NM Stainless Steel

NASA Astrophysics Data System (ADS)

Sarafan, Sheida; Wanjara, Priti; Gholipour, Javad; Champliaud, Henri; Mathieu, Louis

2017-10-01

Design of hydroelectric turbine components requires high integrity welds (without detectable volumetric defects) in heavy gage sections of stainless steel materials, such as ASTM A743 grade CA6NM—a low carbon 13% Cr-4% Ni martensitic stainless steel that is manufactured in cast form. In this work, 90-mm-thick plates of CA6NM were joined using a single-pass autogenous electron beam (EB) welding process and the mechanical properties were evaluated in the as-welded condition to characterize the performance of the joints. The static tensile properties that were evaluated in two directions—transverse and longitudinal to the EB weld seam—demonstrated conformance of the joints with the requirements of the ASME Section IX standard. The Charpy impact energies of the EB welds—measured at -18 °C on samples with V-notch roots located in the fusion and heat-affected zones—met the minimum requirements of 27 J specified in ASME Section VIII standard. In addition, bend tests that were conducted on the entire weld cross section displayed no discontinuities on the tension side of the bent joints. Hence, the developed EB welding process was demonstrated to render high-performance joints and promises key advantages for industrialization, such as cost savings through reductions in consumable material, production time and labor intensity.

Nutritional support for children with epidermolysis bullosa.

PubMed

Haynes, Lesley

Epidermolysis bullosa (EB) comprises a rare group of genetically determined skin blistering disorders characterized by extreme fragility of the skin and mucous membranes, with recurrent blister formation. The cornerstones of management are control of infection, wound management, pain relief, promotion of optimal nutritional status and mobility, surgical intervention and provision of the best possible quality of life. There is currently no cure for EB and, throughout life, those with the more severe types are at risk of significant nutritional compromise which impacts negatively on health and overall quality of life. Nutritional support is an important facet of holistic care and the dietetic challenges can be considerable. This paper describes some of the issues involved in optimizing the nutritional status of children with this disorder.

Electrical, thermal and magnetic studies on 7.5 MeV electron beam irradiated PrCoO3 polycrystalline samples

NASA Astrophysics Data System (ADS)

Christopher, Benedict; Rao, Ashok; Deka, Utpal; Prasad K, Shyam; Okram, G. S.; Sanjeev, Ganesh; Chandra Petwal, Vikash; Verma, Vijay Pal; Dwivedi, Jishnu

2018-07-01

The study of electronic and magnetic properties of electron beam (EB) irradiated PrCoO3 manganites is presented in this communication. The diffraction data confirms that pristine as well as electron beam irradiated samples are single phased and they crystalize at orthorhombic distorted structure with Pbnm space group. The electrical resistivity of all the samples reveals semiconducting behavior. Small polaron hopping model is appropriately employed to investigate the semiconducting nature of the pristine and EB irradiated samples. The Seebeck coefficient (S) data of the pristine sample exhibits colossally high positive value (about 300 mV/K) and substantial decrease in S value is noticed in the irradiated samples. The high temperature analysis of thermopower data validates the small polaron hopping model. The magnetic measurements display possible existence of super-paramagnetic characteristics in the samples.

EB and EUV lithography using inedible cellulose-based biomass resist material

NASA Astrophysics Data System (ADS)

Takei, Satoshi; Hanabata, Makoto; Oshima, Akihiro; Kashiwakura, Miki; Kozawa, Takahiro; Tagawa, Seiichi

2016-03-01

The validity of our approach of inedible cellulose-based resist material derived from woody biomass has been confirmed experimentally for the use of pure water in organic solvent-free water spin-coating and tetramethylammonium hydroxide(TMAH)-free water-developable techniques of eco-conscious electron beam (EB) and extreme-ultraviolet (EUV) lithography. The water developable, non-chemically amplified, high sensitive, and negative tone resist material in EB and EUV lithography was developed for environmental affair, safety, easiness of handling, and health of the working people. The inedible cellulose-based biomass resist material was developed by replacing the hydroxyl groups in the beta-linked disaccharides with EB and EUV sensitive groups. The 50-100 nm line and space width, and little footing profiles of cellulose-based biomass resist material on hardmask and layer were resolved at the doses of 10-30 μC/cm2. The eco-conscious lithography techniques was referred to as green EB and EUV lithography using inedible cellulose-based biomass resist material.

Thermal barrier coating life prediction model development, phase 2

NASA Technical Reports Server (NTRS)

Meier, Susan Manning; Sheffler, Keith D.; Nissley, David M.

1991-01-01

The objective of this program was to generate a life prediction model for electron-beam-physical vapor deposited (EB-PVD) zirconia thermal barrier coating (TBC) on gas turbine engine components. Specific activities involved in development of the EB-PVD life prediction model included measurement of EB-PVD ceramic physical and mechanical properties and adherence strength, measurement of the thermally grown oxide (TGO) growth kinetics, generation of quantitative cyclic thermal spallation life data, and development of a spallation life prediction model. Life data useful for model development was obtained by exposing instrumented, EB-PVD ceramic coated cylindrical specimens in a jet fueled burner rig. Monotonic compression and tensile mechanical tests and physical property tests were conducted to obtain the EB-PVD ceramic behavior required for burner rig specimen analysis. As part of that effort, a nonlinear constitutive model was developed for the EB-PVD ceramic. Spallation failure of the EB-PVD TBC system consistently occurred at the TGO-metal interface. Calculated out-of-plane stresses were a small fraction of that required to statically fail the TGO. Thus, EB-PVD spallation was attributed to the interfacial cracking caused by in-plane TGO strains. Since TGO mechanical properties were not measured in this program, calculation of the burner rig specimen TGO in-plane strains was performed by using alumina properties. A life model based on maximum in-plane TGO tensile mechanical strain and TGO thickness correlated the burner rig specimen EB-PVD ceramic spallation lives within a factor of about plus or minus 2X.

Improvement of sub-20nm pattern quality with dose modulation technique for NIL template production

NASA Astrophysics Data System (ADS)

Yagawa, Keisuke; Ugajin, Kunihiro; Suenaga, Machiko; Kanamitsu, Shingo; Motokawa, Takeharu; Hagihara, Kazuki; Arisawa, Yukiyasu; Kobayashi, Sachiko; Saito, Masato; Ito, Masamitsu

2016-04-01

Nanoimprint lithography (NIL) technology is in the spotlight as a next-generation semiconductor manufacturing technique for integrated circuits at 22 nm and beyond. NIL is the unmagnified lithography technique using template which is replicated from master templates. On the other hand, master templates are currently fabricated by electron-beam (EB) lithography[1]. In near future, finer patterns less than 15nm will be required on master template and EB data volume increases exponentially. So, we confront with a difficult challenge. A higher resolution EB mask writer and a high performance fabrication process will be required. In our previous study, we investigated a potential of photomask fabrication process for finer patterning and achieved 15.5nm line and space (L/S) pattern on template by using VSB (Variable Shaped Beam) type EB mask writer and chemically amplified resist. In contrast, we found that a contrast loss by backscattering decreases the performance of finer patterning. For semiconductor devices manufacturing, we must fabricate complicated patterns which includes high and low density simultaneously except for consecutive L/S pattern. Then it's quite important to develop a technique to make various size or coverage patterns all at once. In this study, a small feature pattern was experimentally formed on master template with dose modulation technique. This technique makes it possible to apply the appropriate exposure dose for each pattern size. As a result, we succeed to improve the performance of finer patterning in bright field area. These results show that the performance of current EB lithography process have a potential to fabricate NIL template.

Vertical beam size measurement in the CESR-TA e+e- storage ring using x-rays from synchrotron radiation

NASA Astrophysics Data System (ADS)

Alexander, J. P.; Chatterjee, A.; Conolly, C.; Edwards, E.; Ehrlichman, M. P.; Fontes, E.; Heltsley, B. K.; Hopkins, W.; Lyndaker, A.; Peterson, D. P.; Rider, N. T.; Rubin, D. L.; Savino, J.; Seeley, R.; Shanks, J.; Flanagan, J. W.

2014-06-01

We describe the construction and operation of an X-ray beam size monitor (xBSM), a device measuring e+ and e- beam sizes in the CESR-TA storage ring using synchrotron radiation. The device can measure vertical beam sizes of 10-100μm on a turn-by-turn, bunch-by-bunch basis at e± beam energies of ~2GeV. At such beam energies the xBSM images X-rays of ɛ≈1-10keV (λ≈0.1-1nm) that emerge from a hard-bend magnet through a single- or multiple-slit (coded aperture) optical element onto an array of 32 InGaAs photodiodes with 50μm pitch. Beamlines and detectors are entirely in-vacuum, enabling single-shot beam size measurement down to below 0.1 mA (2.5×109 particles) per bunch and inter-bunch spacing of as little as 4 ns. At Eb=2.1GeV, systematic precision of ~1μm is achieved for a beam size of ~12μm; this is expected to scale as ∝1/σb and ∝1/Eb. Achieving this precision requires comprehensive alignment and calibration of the detector, optical elements, and X-ray beam. Data from the xBSM have been used to extract characteristics of beam oscillations on long and short timescales, and to make detailed studies of low-emittance tuning, intra-beam scattering, electron cloud effects, and multi-bunch instabilities.

The implementation of physical safety system in bunker of the electron beam accelerator

NASA Astrophysics Data System (ADS)

Ahmad, M. A.; Hashim, S. A.; Ahmad, A.; Leo, K. W.; Chulan, R. M.; Dalim, Y.; Baijan, A. H.; Zain, M. F.; Ros, R. C.

2017-01-01

This paper describes the implementation of physical safety system for the new low energy electron beam (EB) accelerator installed at Block 43T Nuclear Malaysia. The low energy EB is a locally designed and developed with a target energy of 300 keV. The issues on radiation protection have been addressed by the installation of radiation shielding in the form of a bunker and installation radiation monitors. Additional precaution is needed to ensure that personnel are not exposed to radiation and other physical hazards. Unintentional access to the radiation room can cause serious hazard and hence safety features must be installed to prevent such events. In this work we design and built a control and monitoring system for the shielding door. The system provides signals to the EB control panel to allow or prevent operation. The design includes limit switches, key-activated switches and emergency stop button and surveillance camera. Entry procedure is also developed as written record and for information purposes. As a result, through this safety implementation human error will be prevented, increase alertness during operation and minimizing unnecessary radiation exposure.

Enhancing the oxidation resistance of graphite by applying an SiC coat with crack healing at an elevated temperature

NASA Astrophysics Data System (ADS)

Park, Jae-Won; Kim, Eung-Seon; Kim, Jae-Un; Kim, Yootaek; Windes, William E.

2016-08-01

The potential of reducing the oxidation of the supporting graphite components during normal and/or accident conditions in the Very High Temperature Reactor (VHTR) design has been studied. In this work efforts have been made to slow the oxidation process of the graphite with a thin SiC coating (∼ 10 μm). Upon heating at ≥ 1173 K in air, the spallations and cracks were formed in the dense columnar structured SiC coating layer grown on the graphite with a functionally gradient electron beam physical vapor deposition (EB-PVD. In accordance with the formations of these defects, the sample was vigorously oxidized, leaving only the SiC coating layer. Then, efforts were made to heal the surface defects using additional EB-PVD with ion beam bombardment and chemical vapor deposition (CVD). The EB-PVD did not effectively heal the cracks. But, the CVD was more appropriate for crack healing, likely due to its excellent crack line filling capability with a high density and high aspect ratio. It took ∼ 34 min for the 20% weight loss of the CVD crack healed sample in the oxidation test with annealing at 1173 K, while it took ∼ 8 min for the EB-PVD coated sample, which means it took ∼4 times longer at 1173 K for the same weight reduction in this experimental set-up.

The effect of carbon black (CB) loading on curing characteristics and mechanical properties of virgin acrylonitrile butadiene rubber (Nbrv)/recycled acrylonitrile butadiene rubber (Nbrr) blends

NASA Astrophysics Data System (ADS)

Husnan, M. A.; Ismail, H.; Shuib, R. K.

2018-02-01

Recently, the interest of polymer industry researchers have grown rapidly on the use of specific techniques which can reduce cost and utilize rubber waste into the processing form. The increasing of cognizance in environmental matters and the desire to sustain the resources had fortified the practice of recycling waste materials. In this work, the effect of carbon black loading on curing characteristics and mechanical properties of virgin acrylonitrile butadiene rubber/recycled acrylonitrile butadiene rubber (NBRv/NBRr) blends were studied. Cure time (t90), scorch time (tS2) and swelling percentage decreased but minimum torque (ML) and maximum torque (MH) increased with increasing carbon black (CB) loading in the blends. Increasing CB loading also increased tensile strength, tensile modulus (M100), hardness and compression set but decreased elongation at break (Eb) of NBRv/NBRr blends.

Application of the unified mask data format based on OASIS for VSB EB writers

NASA Astrophysics Data System (ADS)

Suzuki, Toshio; Hirumi, Junji; Suga, Osamu

2005-11-01

Mask data preparation (MDP) for modern mask manufacturing becomes a complex process because many kinds of EB data formats are used in mask makers and EB data files continue to become bigger by the application of RET. Therefore we developed a unified mask pattern data format named "OASIS.VSB1" and a job deck format named "MALY2" for Variable-Shaped-Beam (VSB) EB writers. OASIS.VSB is the mask pattern data format based on OASISTM 3 (Open Artwork System Interchange Standard) released as a successive format to GDSII by SEMI. We defined restrictions on OASIS for VSB EB writers to input OASIS.VSB data directly to VSB EB writers just like the native EB data. OASIS.VSB specification and MALY specification have been disclosed to the public and will become a SEMI standard in the near future. We started to promote the spread activities of OASIS.VSB and MALY. For practical use of OASIS.VSB and MALY, we are discussing the infrastructure system of MDP processing using OASIS.VSB and MALY with mask makers, VSB EB makers, and device makers. We are also discussing the tools for the infrastructure system with EDA vendors. The infrastructure system will enable TAT, the man-hour, and the cost in MDP to be reduced. In this paper, we propose the plan of the infrastructure system of MDP processing using OASIS.VSB and MALY as an application of OASIS.VSB and MALY.

Effects of interface morphology and TGO thickness on residual stress of EB-PVD thermal barrier coatings

NASA Astrophysics Data System (ADS)

Chen, Jianwei; Zhao, Yang; Ma, Jian

2015-04-01

The residual stress of electron beam-physical vapor deposition (EB-PVD) thermal barrier coatings (TBC) is complex and difficult to be obtained. In this paper, the interface morphology of TBCs subjected to cyclic heating and cooling was observed by SEM. Based on the thermal elastic-plastic finite method, corresponding interface model of TBCs was established. The residual stress of EB-PVD TBCs with different interface morphologies and TGO thicknesses was calculated using the FE method without regard to the presence of cracks and defects. The result shows that the distribution of residual stress is significantly affected by the interface morphology, and the growth of TGO also has influence on the residual stress of TC and TGO.

Curing Composite Materials Using Lower-Energy Electron Beams

NASA Technical Reports Server (NTRS)

Byrne, Catherine A.; Bykanov, Alexander

2004-01-01

In an improved method of fabricating composite-material structures by laying up prepreg tapes (tapes of fiber reinforcement impregnated by uncured matrix materials) and then curing them, one cures the layups by use of beams of electrons having kinetic energies in the range of 200 to 300 keV. In contrast, in a prior method, one used electron beams characterized by kinetic energies up to 20 MeV. The improved method was first suggested by an Italian group in 1993, but had not been demonstrated until recently. With respect to both the prior method and the present improved method, the impetus for the use of electron- beam curing is a desire to avoid the high costs of autoclaves large enough to effect thermal curing of large composite-material structures. Unfortunately, in the prior method, the advantages of electron-beam curing are offset by the need for special walls and ceilings on curing chambers to shield personnel from x rays generated by impacts of energetic electrons. These shields must be thick [typically 2 to 3 ft (about 0.6 to 0.9 m) if made of concrete] and are therefore expensive. They also make it difficult to bring large structures into and out of the curing chambers. Currently, all major companies that fabricate composite-material spacecraft and aircraft structures form their layups by use of automated tape placement (ATP) machines. In the present improved method, an electron-beam gun is attached to an ATP head and used to irradiate the tape as it is pressed onto the workpiece. The electron kinetic energy between 200 and 300 keV is sufficient for penetration of the ply being laid plus one or two of the plies underneath it. Provided that the electron-beam gun is properly positioned, it is possible to administer the required electron dose and, at the same time, to protect personnel with less shielding than is needed in the prior method. Adequate shielding can be provided by concrete walls 6 ft (approximately equal to 1.8 m) high and 16 in. (approximately equal to 41 cm) thick, without a ceiling. The success of the present method depends on the use of a cationic epoxy as the matrix material in the prepreg tape, heating the prepreg tape to a temperature of 50 C immediately prior to layup, and exposing the workpiece to an electron-beam dose of approximately 2 Mrad. Experiments have shown that structures fabricated by the present method have the same mechanical properties as those of nominally identical structures fabricated by the prior method with electron beams of 3 to 4 MeV.

Correlation between structural and transport properties of electron beam irradiated PrMnO3 compounds

NASA Astrophysics Data System (ADS)

Christopher, Benedict; Rao, Ashok; Nagaraja, B. S.; Shyam Prasad, K.; Okram, G. S.; Sanjeev, Ganesh; Petwal, Vikash Chandra; Verma, Vijay Pal; Dwivedi, Jishnu; Poornesh, P.

2018-02-01

The structural, electrical, magnetic, and thermal properties of electron beam (EB) irradiated PrMnO3 manganites were investigated in the present communication. X-ray diffraction data reveals that all samples are single phased with orthorhombic distorted structure (Pbnm). Furthermore, the diffracted data are analyzed in detail using Rietveld refinement technique. It is observed that the EB dosage feebly disturbs the MnO6 octahedra. The electrical resistivity of all the samples exhibits semiconducting behavior. Small polaron hopping model is conveniently employed to investigate the semiconducting nature of the pristine as well as EB irradiated samples. The Seebeck coefficient (S) of the pristine as well as the irradiated samples exhibit large positive values at lower temperatures, signifying holes as the dominant charge carriers. The analysis of Seebeck coefficient data confirms that the small polaron hopping mechanism assists the thermoelectric transport property in the high temperature region. The magnetic measurements confirm the existence of paramagnetic (PM) to ferromagnetic (FM) behavior for the pristine and irradiated samples. In the lower temperature regime, coexistence of FM clusters and AFM matrix is dominating. Thus, the complex magnetic behavior of the compound has been explained in terms of rearrangement of antiferromagnetically coupled ionic moments.

Collective Beam Instabilities in the Taiwan Light Source

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

Chao, Alex W.

2002-08-12

The storage ring at Taiwan Light Source has experienced a strong collective instability since 1994. Various cures have been attempted to suppress this instability, including the use of damping antenna, tunable rf plungers, different filling patterns, and rf gap voltage modulation. So far these cures have improved the beam intensity, but the operation remains to be limited by the instability. The dominant phenomenon is the longitudinal coupled bunch instability. The major source of longitudinal impedance is from rf cavities of Doris type. The high-order modes of the cavity were numerically analyzed using a 3-D code GdfidL. The correlation of themore » observed phenomenon in user operation with high-order modes of rf cavities will be presented. Results of various attempts to suppress beam instabilities will be summarized. Proposed cures for beam instabilities will be discussed.« less

Electron Beam Welding: study of process capability and limitations towards development of nuclear components

NASA Astrophysics Data System (ADS)

Vadolia, Gautam R.; Premjit Singh, K.

2017-04-01

Electron Beam Welding (EBW) technology is an established and widely adopted technique in nuclear research and development area. Electron beam welding was thought of as a candidate process for ITER Vacuum Vessel Fabrication. Dhruva Reactor at BARC, Mumbai and Niobium superconducting accelerator cavity at BARC has adopted the EB welding technique as a fabrication route. Study of process capability and limitations based on available literature is consolidated in this short review paper.

The directed self-assembly for the surface patterning by electron beam II

NASA Astrophysics Data System (ADS)

Nakagawa, Sachiko T.

2015-03-01

When a low-energy electron beam (EB) or a low-energy ion beam (IB) irradiates a crystal of zincblende (ZnS)-type as crystalline Si (c-Si), a very similar {311} planar defect is often observed. Here, we used a molecular dynamics simulation for a c-Si that included uniformly distributed Frenkel-pairs, assuming a wide beam and sparse distribution of defects caused by each EB. We observed the formation of ? linear defects, which agglomerate to form planar defects labeled with the Miller index {311} as well as the case of IB irradiation. These were identified by a crystallographic analysis called pixel mapping (PM) method. The PM had suggested that self-interstitial atoms may be stabilized on a specific frame of a lattice made of invisible metastable sites in the ZnS-type crystal. This agglomeration appears as {311} planar defects. It was possible at a much higher temperature than room temperature,for example, at 1000 K. This implies that whatever disturbance may bring many SIAs in a ZnS-type crystal, elevated lattice vibration promotes self-organization of the SIAs to form {311} planar defects according to the frame of metastable lattice as is guided by a chart presented by crystallography.

Electron beam agrobionanotechnologies for agriculture and food industry enabled by electron accelerators

NASA Astrophysics Data System (ADS)

Pavlov, Y. S.; Revina, A. A.; Souvorova, O. V.; Voropaeva, N. L.; Chekmar, D. V.; Abkhalimov, E. V.; Zavyalov, M. A.; Filippovich, V. P.

2017-12-01

Electron beam (EB) radiation technologies have been employed to increase efficiency of biologically active nanochips developed for agricultural plants seed pre-treatment with purpose of enhancing crop yield and productivity. Iron-containing nanoparticles (NPs), synthesized in reverse micelles following known radiation-chemical technique, have served as a multifunctional biologically active and phytosanitary substance of the chips. Porous chip carriers activation has been performed by EB ionization (doze 20kGy) of the active carbons (AC) prepared from agricultural waste and by-products: Jerusalem artichoke (Helianthus tuberosus) straw, rape (Brassica napus L. ssp. oleifera Metzg) straw, camelina (Camelina sativa (L.) Crantz) straw, wheat (Triticum aestivum) straw. Three methods, UV-VIS spectrophotometry, Electron Paramagnetic Resonance (EPR) spectroscopy, cyclic voltammetry (CV) have been used for process control and characterization of radiation-activated and NPs-modified ACs. The results show a notable effect of ACs activation by electron beam radiation, evidenced by FeNPs-adsorption capacity increase. Studies of the impact of Fe NPs-containing nanochip technology on enhancement of seeds germination rate and seedlings vigour suggest that reported electron beam radiation treatment techniques of the ACs from selected agricultural residues may be advantageous for industrial application.

Degradation Analysis of NBR and Epichlorohydrin Rubber by New Micro Analysis Method

NASA Astrophysics Data System (ADS)

Katoh, Hisao; Kamoto, Ritsu; Murata, Jun

The degradation analysis of NBR and Epichlorohydrin rubber was carried out by infrared micro spectroscopy (μ-IR) and micro sampling mass spectrometry (μ-MS) which gives information on the scission and crosslinking of rubber molecules. Samples were prepared by three different treatments, heat as well as ultra violet (UV) and electron beam (EB) irradiations. It was found for NBR vulcanizates that the heat treatment induced the oxidation, scission and crosslinking of rubber molecules. By the UV treatment, chain scission and crosslinking accompanied by a slight oxidation were induced. The EB treatment enhanced the crosslinking, however, the extent of oxidation was negligible. For Epichlorohydrin rubber vulcanizates, the heat treatment accelerated chain scission rather than crosslinking. On the other hand, the oxidation and crosslinking were induced by the UV and EB treatments.

Effective vortex pinning in MgB2 thin films

NASA Astrophysics Data System (ADS)

Bugoslavsky, Y.; Cowey, L.; Tate, T. J.; Perkins, G. K.; Moore, J.; Lockman, Z.; Berenov, A.; MacManus-Driscoll, J. L.; Caplin, A. D.; Cohen, L. F.; Zhai, H. Y.; Christen, H. M.; Paranthaman, M. P.; Lowndes, D. H.; Jo, M. H.; Blamire, M. G.

2002-10-01

We discuss the pinning properties of MgB2 thin films grown by pulsed-laser deposition (PLD) and by electron-beam (EB) evaporation. Two mechanisms are identified that contribute most effectively to the pinning of vortices in randomly oriented films. The EB process produces low defected crystallites with a small grain size providing enhanced pinning at grain boundaries without any degradation of Tc. The PLD process produces films with structural disorder on a scale less than the coherence length that further improves pinning, but also depresses Tc.

Electron Beam Curing of Composite Positive Electrode for Li-Ion Battery

DOE PAGES

Du, Zhijia; Janke, C. J.; Li, Jianlin; ...

2016-10-12

We have successfully used electron beam cured acrylated polyurethanes as novel binders for positive electrodes for Li-ion batteries. Furthermore, the cross-linked polymer after electron beam curing coheres active materials and carbon black together onto Al foil. Electrochemical tests demonstrate the stability of the polymer at a potential window of 2.0 V–4.6 V. The electrode is found to have similar voltage profiles and charge-transfer resistance compared to the conventional electrode using polyvinylidene fluoride as the binder. Finally, when the electrode is tested in full Li-ion cells, they exhibit excellent cycling performance, indicating promising use for this new type of binder inmore » commercial Li-ion batteries in the future.« less

Effect of concentration of polyfunctional monomers on physical properties of acrylonitrile butadiene rubber under electron-beam irradiation

NASA Astrophysics Data System (ADS)

Yasin, Tariq; Ahmed, Shamshad; Ahmed, Munir; Yoshii, Fumio

2005-06-01

An investigation has been undertaken to find out the effect of concentration of different polyfunctional monomers (PFMs) on the physical properties of the acrylonitrile-butadiene rubber (NBR) crosslinked by electron beam (EB). The PFMs used were diethylene glycol dimethacrylate, trimethylol propane trimethacrylate and trimethylol propane triacrylate. The physical properties of EB-irradiated NBR sheets were evaluated by measuring the tensile strength, elongation percent at break, hardness and gel fraction. The results showed a remarkable increase in tensile strength, hardness and gel fraction as the concentration of PFMs was increased from 1 part per hundred (phr) to 5 phr in the NBR samples whereas elongation percent decreased in a steady manner. The improvement in physical properties of radiation crosslinked NBR in the presence of PFMs may be attributed to its increased crosslinking density as observed by the corresponding increase in gel content.

An empirical study into the effect of long term storage (-36±2 °C) of electron-beamed ETFE on the properties of radiation-grafted alkaline anion-exchange membranes

NASA Astrophysics Data System (ADS)

Kizewski, Jamie Peter; Mudri, Nurul H.; Varcoe, John R.

2013-08-01

The application of alkaline anion-exchange membranes (AAEM) in solid alkaline fuel cells is growing in prominence mainly due to enhanced tolerance to carbon dioxide, compared to alkaline fuel cells containing aqueous electrolytes, and the potential for using non precious metal catalysts. Radiation grafting is a common methodology for the production of functional polymers and membranes. This statistical study examines the synthesis of radiation grafted AAEMs that are formed from electron beam irradiated poly(ethylene-co-tetrafluoroethylene), EB-ETFE. It is shown that EB-ETFE can be cold stored for at least 16 months and still be used to produce ionically conductive AAEMs. The limitations of routine measurements of properties, such as dimensional increases, ion-exchange capacity, water uptakes and ionic conductivities, are also highlighted.

Structure, dielectric, thermal and I-V studies of electron beam irradiated PVDF-HFP/LiClO4 electrolyte film

NASA Astrophysics Data System (ADS)

Yesappa, L.; Niranjana, M.; Ashokkumar, S. P.; Vijeth, H.; Basappa, M.; Ganesh, S.; Devendrappa, H.

2018-05-01

The effect of electron beam (EB) irradiation on polymer electrolyte (PVDF-HFP: LiClO4=90:10, PHL10) films prepared by solution casting method. FT-IR confirms the complexation between salt and polymer upon EB dose. Degradation of polymer and decrease in % of crystallinity from 50.10 to 40.96 at 2θ=19.90° at 120 kGy dose indicates increased amorphousity confirmed by XRD. The TGA result show decrease in Tm from 460 °C to 418 °C is leads to degradation of polymer chain at higher dosage. The dielectric parameters have been determined and observed decreasing trend with increased frequency as well as temperature due to increase the mobility of charge carrier confirms the capacitive nature. I-V plots exhibit an ohmic behavior with applied voltage and irradiation dose. The results notice the change in polymer properties upon irradiation.

High energy electron beam curing of epoxy resin systems incorporating cationic photoinitiators

DOEpatents

Janke, C.J.; Lopata, V.J.; Havens, S.J.; Dorsey, G.F.; Moulton, R.J.

1999-03-02

A mixture of epoxy resins such as a semi-solid triglycidyl ether of tris (hydroxyphenyl) methane and a low viscosity bisphenol A glycidyl ether and a cationic photoinitiator such as a diaryliodonium salt is cured by irradiating with a dosage of electron beams from about 50 to about 150 kGy, forming a cross-linked epoxy resin polymer.

High energy electron beam curing of epoxy resin systems incorporating cationic photoinitiators

DOEpatents

Janke, Christopher J.; Lopata, Vincent J.; Havens, Stephen J.; Dorsey, George F.; Moulton, Richard J.

1999-01-01

A mixture of epoxy resins such as a semi-solid triglycidyl ether of tris (hydroxyphenyl) methane and a low viscosity bisphenol A glycidyl ether and a cationic photoinitiator such as a diaryliodonium salt is cured by irradiating with a dosage of electron beams from about 50 to about 150 kGy, forming a cross-linked epoxy resin polymer.

Energy deposition in ultrathin extreme ultraviolet resist films: extreme ultraviolet photons and keV electrons

NASA Astrophysics Data System (ADS)

Kyser, David F.; Eib, Nicholas K.; Ritchie, Nicholas W. M.

2016-07-01

The absorbed energy density (eV/cm3) deposited by extreme ultraviolet (EUV) photons and electron beam (EB) high-keV electrons is proposed as a metric for characterizing the sensitivity of EUV resist films. Simulations of energy deposition are used to calculate the energy density as a function of the incident aerial flux (EUV: mJ/cm2, EB: μC/cm2). Monte Carlo calculations for electron exposure are utilized, and a Lambert-Beer model for EUV absorption. The ratio of electron flux to photon flux which results in equivalent energy density is calculated for a typical organic chemically amplified resist film and a typical inorganic metal-oxide film. This ratio can be used to screen EUV resist materials with EB measurements and accelerate advances in EUV resist systems.

EB-promoted recycling of waste tire rubber with polyolefins

NASA Astrophysics Data System (ADS)

Mészáros, László; Bárány, Tamás; Czvikovszky, Tibor

2012-09-01

Despite the fact that more and more methods and solutions are used in the recycling of polymers, there are still some problems, especially in the recycling of cross-linked materials such as rubber. Usually the biggest problem is the lack of compatibility between the cross-linked rubber and the thermoplastic matrix. In this study we applied ground tire rubber (GTR) as recycled material. The GTR was embedded into polyethylene (PE) and polyethylene/ethylene-vinyl acetate copolymer (PE/EVA) matrices. In order to increase the compatibility of the components electron beam (EB) irradiation was applied. The results showed that the irradiation has a beneficial effect on the polymer-GTR interfacial connection. The EB treatment increased not only the tensile strength but also the elongation at break. The irradiation had also positive effect on the impact strength properties.

Influence of heat input in electron beam process on microstructure and properties of duplex stainless steel welded interface

NASA Astrophysics Data System (ADS)

Zhang, Zhiqiang; Jing, Hongyang; Xu, Lianyong; Han, Yongdian; Zhao, Lei; Lv, Xiaoqing; Zhang, Jianyang

2018-03-01

The influence of heat input in electron beam (EB) process on microstructure, mechanical properties, and pitting corrosion resistance of duplex stainless steel (DSS) welded interface was investigated. The rapid cooling in EB welding resulted in insufficient austenite formation. The austenite mainly consisted of grain boundary austenite and intragranular austenite, and there was abundant Cr2N precipitation in the ferrite. The Ni, Mo, and Si segregation indicated that the dendritic solidification was primarily ferrite in the weld. The weld exhibited higher hardness, lower toughness, and poorer pitting corrosion resistance than the base metal. The impact fractures of the welds were dominated by the transgranular cleavage failure of the ferrite. The ferrite was selectively attacked because of its lower pitting resistance equivalent number than that of austenite. The Cr2N precipitation accelerated the pitting corrosion. In summary, the optimised heat input slightly increased the austenite content, reduced the segregation degree and ferrite texture intensity, decreased the hardness, and improved the toughness and pitting corrosion resistance. However, the effects were limited. Furthermore, optimising the heat input could not suppress the Cr2N precipitation. Taking into full consideration the microstructure and properties, a heat input of 0.46 kJ/mm is recommended for the EB welding of DSS.

Onorbit electron beam welding experiment definition

NASA Technical Reports Server (NTRS)

1989-01-01

The proposed experiment design calls for six panels to be welded, each having unique characteristics selected to yield specific results and information. The experiment is completely automated and the concept necessitated the design of a new, miniaturized, self-contained electron beam (EB) welding system, for which purpose a separate IR and D was funded by the contractor, Martin Marietta Corporation. Since future tasks beyond the proposed experiment might call for astronauts to perform hand-held EB gun repairs or for the gun to be interfaced with a dexterous robot such as the planned flight telerobotic servicer (FTS), the EB gun is designed to be dismountable from the automated system. In the experiment design, two separate, identical sets of weld panels will be welded, one on earth in a vacuum chamber and the other onorbit in the aft cargo bay of an orbiter. Since the main objective of the experiment is to demonstrate that high quality welds can be achieved under onorbit conditions, the welds produced will be subjected to a wide range of discriminating non-destructive Q.C. procedures and destructive physical tests. However, advantage will be taken of the availability of a fairly large quantity of welded material in the two series of welded specimens to widen the circle of investigative talent by providing material to academic and scientific institutions for examination.

Electron-beam lithography with character projection exposure for throughput enhancement with line-edge quality optimization

NASA Astrophysics Data System (ADS)

Ikeno, Rimon; Maruyama, Satoshi; Mita, Yoshio; Ikeda, Makoto; Asada, Kunihiro

2016-03-01

Among various electron-beam lithography (EBL) techniques, variable-shaped beam (VSB) and character projection (CP) methods have attracted many EBL users for their high-throughput feature, but they are considered to be more suited to small-featured VLSI fabrication with regularly-arranged layouts like standard-cell logics and memory arrays. On the other hand, non-VLSI applications like photonics, MEMS, MOEMS, and so on, have not been fully utilized the benefit of CP method due to their wide variety of layout patterns. In addition, the stepwise edge shapes by VSB method often causes intolerable edge roughness to degrade device characteristics from its intended performance with smooth edges. We proposed an overall EBL methodology applicable to wade-variety of EBL applications utilizing VSB and CP methods. Its key idea is in our layout data conversion algorithm that decomposes curved or oblique edges of arbitrary layout patterns into CP shots. We expect significant reduction in EB shot count with a CP-bordered exposure data compared to the corresponding VSB-alone conversion result. Several CP conversion parameters are used to optimize EB exposure throughput, edge quality, and resultant device characteristics. We demonstrated out methodology using the leading-edge VSB/CP EBL tool, ADVANTEST F7000S-VD02, with high resolution Hydrogen Silsesquioxane (HSQ) resist. Through our experiments of curved and oblique edge lithography under various data conversion conditions, we learned correspondence of the conversion parameters to the resultant edge roughness and other conditions. They will be utilized as the fundamental data for further enhancement of our EBL strategy for optimized EB exposure.

Development of palm oil-based UV-curable epoxy acrylate and urethane acrylate resins for wood coating application

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

Tajau, Rida; Mahmood, Mohd Hilmi; Salleh, Mek Zah

The trend of using renewable sources such as palm oil as raw material in radiation curing is growing due to the demand from the market to produce a more environmental friendly product. In this study, the radiation curable process was done using epoxy acrylate and urethane acrylate resins which are known as epoxidised palm olein acrylate (EPOLA) and palm oil based urethane acrylate (POBUA), respectively. The purpose of the study was to investigate curing properties and the application of this UV-curable palm oil resins for wood coating. Furthermore, the properties of palm oil based coatings are compared with the petrochemical-basedmore » compound such as ebecryl (EB) i.e. EB264 and EB830. From the experiment done, the resins from petrochemical-based compounds resulted higher degree of crosslinking (up to 80%) than the palm oil based compounds (up to 70%), where the different is around 10-15%. The hardness property from this two type coatings can reached until 50% at the lower percentage of the oligomer. However, the coatings from petrochemical-based have a high scratch resistance as it can withstand at least up to 3.0 Newtons (N) compared to the palm oil-based compounds which are difficult to withstand the load up to 1.0 N. Finally, the test on the rubber wood substrate showed that the coatings containing benzophenone photoinitiator give higher adhesion property and their also showed a higher glosiness property on the glass substrate compared to the coatings containing irgacure-819 photoinitiator. This study showed that the palm oil coatings can be a suitable for the replacement of petrochemicals compound for wood coating. The palm oil coatings can be more competitive in the market if the problems of using high percentage palm oil oligomer can be overcome as the palm oil price is cheap enough.« less

Radiation Interaction with Therapeutic Drugs and Cell Membranes

NASA Astrophysics Data System (ADS)

Martin, Diana I.; Manaila, Elena N.; Moisescu, Mihaela I.; Savopol, Tudor D.; Kovacs, Eugenia A.; Cinca, Sabin A.; Matei, Constantin I.; Margaritescu, Irina D.; Iacob, Nicusor I.; Ighigeanu, Daniel I.; Craciun, Gabriela D.

2007-04-01

This transient permeabilized state of the cell membrane, named the ``cell electroporation'' (CE) can be used to increase cells uptake of drugs that do not readily pass cell membrane, thus enabling their cytotoxicity. The anticancer drugs, such as bleomycin (BL) and cisplatin, are the most candidates for the combined use with ionizing and non-ionizing radiation fields. The methods and installations for the cell electroporation by electron beam (EB) and microwave (MW) irradiation are presented. The viability tests of the human leukocytes under EB and MW exposure with/without the BL in the cell cultures are discussed.

Fabrication and characterization of tapered graphite/epoxy box beams

NASA Astrophysics Data System (ADS)

Yen, S.-C.; Gopal, P.; Dharani, L. R.

1993-04-01

Graphite/epoxy (T300/934) prepreg is used to fabricate tapered box beams with a taper angle of 2 deg between the top and bottom walls. The prepreg is cured on a segmented steel core using a hot-press. A screw arrangement is used to apply curing pressure in the horizontal direction, while the platens of the hot-press apply pressure in the vertical direction. The inplane bending stiffness of the beam is determined by 3-point bend test and is found to be in agreement with theory.

Fusion welding of a modern borated stainless steel

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

Robino, C.V.; Cieslak, M.J.

1997-01-01

Experiments designed to assess the fabrication and service weldability of 304B4A borated stainless steel were conducted. Welding procedures and parameters for manual gas tungsten arc (GTA) welding, autogenous electron beam (EB) welding and filler-added EB welding were developed and found to be similar to those for austenitic stainless steels. Following the procedure development, four test welds were produced and evaluated by microstructural analysis and Charpy impact testing. Further samples were used for determination of the postweld heat treatment (PWHT) response of the welds. The fusion zone structure of welds in this alloy consists of primary austenite dendrites with an interdendriticmore » eutectic-like austenite/boride constituent. Welds also show an appreciable partially molten zone that consists of the austenite/boride eutectic surrounding unmelted austenite islands. The microstructure of the EB welds was substantially finer than that of the GTA welds, and boride coarsening was not observed in the solid state heat-affected zone (HAZ) of either weld type. The impact toughness of as-welded samples was found to be relatively poor, averaging less than 10 J for both GTA and EB welds. For fusion zone notched GTA and EB samples and centerline notched EB samples, fracture generally occurred along the boundary between the partially molten and solid-state regions of the HAZ. The results of the PWHT study were very encouraging, with typical values of the impact energy for HAZ notched samples approaching 40 J, or twice the minimum code-acceptable value.« less

The impact of electron beam irradiation on Low density polyethylene and Ethylene vinyl acetate

NASA Astrophysics Data System (ADS)

Sabet, Maziyar; Soleimani, Hassan

2017-05-01

Improvement of measured gel content, hardness, tensile strength and elongation at break of Ethylene vinyl acetate (EVA) have confirmed positive effect of electron beam irradiation on EVA. Results obtained from both gel content tests show that degree of cross-linking in amorphous regions is dependent on dose. A significant improvement in tensile strength of neat EVA samples is obtained upon electron-beam radiation up to 210 kGy. Similarly, hardness properties of Low-density polyethylene (LDPE) improvewith increasing electron beam irradiation. This article deals with the impacts of electron beam (EB) irradiation on the properties of LDPE and Ethylene-Vinyl Acetate (EVA) as the two common based formulations for wire and cable applications.

External Beam Accelerated Partial Breast Irradiation Yields Favorable Outcomes in Patients with Prior Breast Augmentation

PubMed Central

Lei, Rachel Y.; Leonard, Charles E.; Howell, Kathryn T.; Henkenberns, Phyllis L.; Johnson, Timothy K.; Hobart, Tracy L.; Kercher, Jane M.; Widner, Jodi L.; Kaske, Terese; Barke, Lora D.; Carter, Dennis L.

2014-01-01

Purpose: To report outcomes in breast cancer patients with prior breast augmentation treated with external beam accelerated partial breast irradiation (EB-APBI) utilizing intensity-modulated radiotherapy or 3-dimensional conformal radiotherapy, both with IGRT. Materials and Methods: Sixteen stage 0/1 breast cancer patients with previous elective bilateral augmentation were treated post-lumpectomy on institutional EB-APBI trials (01185132 and 01185145 on clinicaltrials.gov). Patients received 38.5 Gy in 10 fractions over five consecutive days. Breast/chest wall pain and cosmesis were rated by patient; cosmesis was additionally evaluated by physician per RTOG criteria. Results: The median follow-up from accelerated partial breast irradiation (APBI) completion was 23.9 months (range, 1.2–58.6). Little to no change in cosmesis or pain from baseline was reported. Cosmetic outcomes at last follow-up were judged by patients as excellent/good in 81.2% (13/16), and by physicians as excellent/good in 93.8% (15/16). Ten patients (62.5%) reported no breast/chest wall pain, five (31.2%) reported mild pain, and one (6.2%) reported moderate pain. All patients remain disease free at last follow-up. The median ipsilateral breast, planning target volume (PTV), and implant volumes were 614, 57, and 333 cm3. The median ratios of PTV/ipsilateral breast volume (implant excluded) and PTV/total volume (implant included) were 9 and 6%. Conclusion: These 16 breast cancer cases with prior bilateral augmentation treated with EB-APBI demonstrate favorable clinical outcomes. Further exploration of EB-APBI as a treatment option for this patient population is warranted. PMID:24995159

Periodically poled lithium niobate by electron beam: irradiation conditions and second harmonic generation

NASA Astrophysics Data System (ADS)

Restoin, C.; Couderc, Vincent; Darraud-Taupiac, Claire; Decossas, J.-Louis; Vareille, J.-C.; Barthelemy, Alain; Hauden, Jerome

2000-12-01

Second Harmonic Generation (SHG) using counter-propagating Quasi Phase Matching (QPM) configuration often requires a fine non-linearity with a period of a fraction of a micrometer. The direct Electron Beam (EB) domain reversal technique seems to be promising to achieve gratings on LiNbO3 with such a small period compared to other current poling technologies as it is lithographic free and exhibits a very high theoretical resolution (5 mm). We present here, a preliminary study concerning the influence of EB irradiation conditions on domain inversion; SHG is also examined on a 6.58 j.tm inverted periodic domain grating in lithium niobate using a Nd-YaG laser light. It is well known that LiNbO3 is an attractive material for many optical applications because of its transparency over a large wavelength band (350 mm to 5000 mm) and its high nonlinear coefficients. EB irradiation is performed using a Scanning Electron Microscope (SEM) driven by a Computer Aided Design (CAD) application developed in our laboratory. Various structures such as periodic gratings can be written with the chosen period. The ferroelectric domain inversion is investigated as a function of the accelerating voltage of the electrons (10 to 30 kV), the scanning speed of the EB (0.97 to 7.76 mm/s) and the current received by the sample (1.6 to 14 nA). The inversion patterns have been revealed by chemical etching (HF) and they have been observed using SEM. It has been shown that the duty cycle is respected on the irradiated face. The SHG conversion efficiency is measured as a function of the temperature and the grating period is calculated (value of6.564 jim).

Neuroprotective role of quercetin in locomotor activities and cholinergic neurotransmission in rats experimentally demyelinated with ethidium bromide.

PubMed

Beckmann, Diego V; Carvalho, Fabiano B; Mazzanti, Cinthia M; Dos Santos, Rosmarini P; Andrades, Amanda O; Aiello, Graciane; Rippilinger, Angel; Graça, Dominguita L; Abdalla, Fátima H; Oliveira, Lizielle S; Gutierres, Jessié M; Schetinger, Maria Rosa C; Mazzanti, Alexandre

2014-05-17

The purpose of this study was to investigate whether the flavonoid quercetin can prevent alterations in the behavioral tests and of cholinergic neurotransmission in rats submitted to the ethidium bromide (EB) experimental demyelination model during events of demyelination and remyelination. Wistar rats were randomly distributed into four groups (20 animals per group): Control (pontine saline injection and treatment with ethanol), Querc (pontine saline injection and treatment with quercetin), EB (pontine 0.1% EB injection and treatment with ethanol), and EB+Querc (pontine 0.1% EB injection and treatment with quercetin). The groups Querc and Querc+EB were treated once daily with quercetin (50mg/kg) diluted in 25% ethanol solution (1ml/kg) and the animals of the control and EB groups were treated once daily with 25% ethanol solution (1ml/kg). Two stages were observed: phase of demyelination (peak on day 7) and phase of remyelination (peak on day 21 post-injection). Behavioral tests (beam walking, foot fault and inclined plane test), acetylcholinesterase (AChE) activity and lipid peroxidation in pons, cerebellum, hippocampus, hypothalamus, striatum and cerebral cortex were measured. The quercetin promoted earlier locomotor recovery, suggesting that there was demyelination prevention or further remyelination velocity as well as it was able to prevent the inhibition of AChE activity and the increase of lipidic peroxidation, suggesting that this compound can protect cholinergic neurotransmission. These results may contribute to a better understanding of the neuroprotective role of quercetin and the importance of an antioxidant diet in humans to provide benefits in neurodegenerative diseases such as MS. Copyright © 2014. Published by Elsevier Inc.

Electron beams in research and technology

NASA Astrophysics Data System (ADS)

Mehnert, R.

1995-11-01

Fast electrons lose their energy by inelastic collisions with electrons of target molecules forming secondary electrons and excited molecules. Coulomb interaction of secondary electrons with valence electrons of neighboring molecules leads to the formation of radical cations, thermalized electrons, excited molecular states and radicals. The primary reactive species initiate chemical reactions in the materials irradiated. Polymer modifications using accelerated electrons such as cross-linking of cable insulation, tubes, pipes and moldings, vulcanization of elastomers, grafting of polymer surfaces, processing of foamed plastics and heat shrinkable materials have gained wide industrial acceptance. A steadily growing electron beam technology is curing of paints, lacquers, printing inks and functional coatings. Electron beam processing offers high productivity, the possibility to treat the materials at normal temperature and pressure, excellent process control and clean production conditions. On an industrial scale the most important application of fast electrons is curing of 100% reactive monomer/prepolymer systems. Mainly acrylates and epoxides are used to formulate functional coatings on substrates such as paper, foil, wood, fibre board and high pressure laminates. A survey is given about the reaction mechanism of curing, the characterization of cured coatings, and of some industrial application.

The Design and Synthesis of Epoxy Matrix Composites Curable by Electron Beam Induced Cationic Polymerization

NASA Technical Reports Server (NTRS)

Crivello, James V.

2000-01-01

Several new series of novel, high reactivity epoxy resins are described which are designed specifically for the fabrication of high performance carbon fiber reinforced composites for commercial aircraft structural applications using cationic UV and e-beam curing. The objective of this investigation is to provide resin matrices which rapidly and efficiently cure under low e-beam doses which are suitable to high speed automated composite fabrication techniques such as automated tape and tow placement. It was further the objective of this work to provide resins with superior thermal, oxidative and atomic oxygen resistance.

Defining robustness protocols: a method to include and evaluate robustness in clinical plans

NASA Astrophysics Data System (ADS)

McGowan, S. E.; Albertini, F.; Thomas, S. J.; Lomax, A. J.

2015-04-01

We aim to define a site-specific robustness protocol to be used during the clinical plan evaluation process. Plan robustness of 16 skull base IMPT plans to systematic range and random set-up errors have been retrospectively and systematically analysed. This was determined by calculating the error-bar dose distribution (ebDD) for all the plans and by defining some metrics used to define protocols aiding the plan assessment. Additionally, an example of how to clinically use the defined robustness database is given whereby a plan with sub-optimal brainstem robustness was identified. The advantage of using different beam arrangements to improve the plan robustness was analysed. Using the ebDD it was found range errors had a smaller effect on dose distribution than the corresponding set-up error in a single fraction, and that organs at risk were most robust to the range errors, whereas the target was more robust to set-up errors. A database was created to aid planners in terms of plan robustness aims in these volumes. This resulted in the definition of site-specific robustness protocols. The use of robustness constraints allowed for the identification of a specific patient that may have benefited from a treatment of greater individuality. A new beam arrangement showed to be preferential when balancing conformality and robustness for this case. The ebDD and error-bar volume histogram proved effective in analysing plan robustness. The process of retrospective analysis could be used to establish site-specific robustness planning protocols in proton therapy. These protocols allow the planner to determine plans that, although delivering a dosimetrically adequate dose distribution, have resulted in sub-optimal robustness to these uncertainties. For these cases the use of different beam start conditions may improve the plan robustness to set-up and range uncertainties.

Liquid-phase explosive crystallization of electron-beam-evaporated a-Si films induced by flash lamp annealing

NASA Astrophysics Data System (ADS)

Ohdaira, Keisuke; Matsumura, Hideki

2013-01-01

We succeed in the formation of micrometer-order-thick polycrystalline silicon (poly-Si) films through the flash-lamp-induced liquid-phase explosive crystallization (EC) of precursor a-Si films prepared by electron-beam (EB) evaporation. The velocity of the explosive crystallization (vEC) is estimated to be ˜14 m/s, which is close to the velocity of the liquid-phase epitaxy (LPE) of Si at a temperature around the melting point of a-Si of 1418 K. Poly-Si films formed have micrometer-order-long grains stretched along a lateral crystallization direction, and X-ray diffraction (XRD) and electron diffraction pattern measurements reveal that grains in poly-Si films tend to have a particular orientation. These features are significantly different from our previous results: the formation of poly-Si films containing randomly-oriented 10-nm-sized fine grains formed from a-Si films prepared by catalytic chemical vapor deposition (Cat-CVD) or sputtering. One possible reason for the emergence of a different EC mode in EB-evaporated a-Si films is the suppression of solid-phase nucleation (SPN) during Flash Lamp Annealing (FLA) due to tensile stress which precursor a-Si films originally hold. Poly-Si films formed from EB-evaporated a-Si films would contribute to the realization of high-efficiency thin-film poly-Si solar cells because of large and oriented grains.

Recent High Heat Flux Tests on W-Rod-Armored Mockups

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

NYGREN,RICHARD E.; YOUCHISON,DENNIS L.; MCDONALD,JIMMIE M.

2000-07-18

In the authors initial high heat flux tests on small mockups armored with W rods, done in the small electron beam facility (EBTS) at Sandia National Laboratories, the mockups exhibited excellent thermal performance. However, to reach high heat fluxes, they reduced the heated area to only a portion ({approximately}25%) of the sample. They have now begun tests in their larger electron beam facility, EB 1200, where the available power (1.2 MW) is more than enough to heat the entire surface area of the small mockups. The initial results indicate that, at a given power, the surface temperatures of rods inmore » the EB 1200 tests is somewhat higher than was observed in the EBTS tests. Also, it appears that one mockup (PW-10) has higher surface temperatures than other mockups with similar height (10mm) W rods, and that the previously reported values of absorbed heat flux on this mockup were too high. In the tests in EB 1200 of a second mockup, PW-4, absorbed heat fluxes of {approximately}22MW/m{sup 2} were reached but the corresponding surface temperatures were somewhat higher than in EBTS. A further conclusion is that the simple 1-D model initially used in evaluating some of the results from the EBTS testing was not adequate, and 3-D thermal modeling will be needed to interpret the results.« less

Electron beam initiated modification of acrylic elastomer in presence of polyfunctional monomers

NASA Astrophysics Data System (ADS)

Vijayabaskar, V.; Bhattacharya, S.; Tikku, V. K.; Bhowmick, Anil K.

2004-12-01

The structural changes of an acrylic rubber (ACM) in presence and absence of polyfunctional monomers like trimethylolpropane triacrylate, tripropyleneglycol diacrylate, trimethylolmethane tetraacrylate and trimethylolpropane trimethacrylate at different doses of electron beam (EB) irradiations were investigated with the help of FTIR spectroscopy (in the attenuated total reflectance mode) and sol-gel analysis. As the radiation dose increases, the concentration of carbonyl group increases in the ACM rubber due to aerial oxidation. This is corroborated from the increase in the absorbance values at 1734 and 1160 cm -1, which are due to carbonyl and C-O-C stretching frequencies, respectively. The increase in crosslinking is revealed by the increase in percentage gel content with radiation dose. The lifetime of spurs formed and the critical dose, an important criterion for overlapping of spurs have been determined for both grafted and ungrafted ACM rubber using a mathematical model. The predominance of crosslinking by electronic stopping with energetic EB projectile and the increase in effective radius of crosslinking have also been verified by this model. The doses at which the synergistic occurrence of both dislinking and endlinking steps originate have been calculated using linear energy transfer of EB. The ratio of scissioning to crosslinking for ACM rubber has been determined by using Charlesby-Pinner equation. The mechanical properties have been studied for different modified and unmodified systems and the tensile strength is found to increase with grafting of polyfunctional monomers.

Ion beam methods applied to interior ballistic studies

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

Niler, A.

1981-04-01

High temperature, pressure and velocity gases produced during the interior ballistic cycle of a gun firing are responsible for considerable damage to the steel surfaces of a gun bore. This damage is studied by exposing steel samples to the erosive flows of burning propellant gases in a modified 37mm gun chamber where pressures of 200 MPa and flame temperatures of 3000/sup 0/K are typical. Ion beam methods are used to characterize the composition of the steel surfaces by combined nuclear reaction (NR) and elastic backscattering (EBS) analysis and thin layer activation (TLA) is used to measure surface wear rates. Combinedmore » fits to the EBS and NR distributions yield concentrations and depth profiles of carbon, nitrogen and oxygen as well as iron and other heavier elements. Hydrogen concentrations have also been measured on some of the samples. The results of these experiments show the presence of two different erosion mechanisms. In one, the surface is softened by thermo-chemical processes prior to removal by the shear forces of the gas flow while in the other surface layer melting occurs prior to removal. TLA using the /sup 56/Fe(p,n)/sup 56/Co reaction has been used to measure wear from a 20 mm barrel and is being instrumented for larger barrels. EBS is being used to characterize the interfaces between steel substrates and coatings designed to reduce erosion.« less

A process model for the heat-affected zone microstructure evolution in duplex stainless steel weldments: Part II. Application to electron beam welding

NASA Astrophysics Data System (ADS)

Hemmer, H.; Grong, Ø.; Klokkehaug, S.

2000-03-01

In the present investigation, a process model for electron beam (EB) welding of different grades of duplex stainless steels (i.e. SAF 2205 and 2507) has been developed. A number of attractive features are built into the original finite element code, including (1) a separate module for prediction of the penetration depth and distribution of the heat source into the plate, (2) adaptive refinement of the three-dimensional (3-D) element mesh for quick and reliable solution of the differential heat flow equation, and (3) special subroutines for calculation of the heat-affected zone (HAZ) microstructure evolution. The process model has been validated by comparison with experimental data obtained from in situ thermocouple measurements and optical microscope examinations. Subsequently, its aptness to alloy design and optimization of welding conditions for duplex stainless steels is illustrated in different numerical examples and case studies pertaining to EB welding of tubular joints.

Development of new FIB technology for EUVL mask repair

NASA Astrophysics Data System (ADS)

Aramaki, Fumio; Ogawa, Takashi; Matsuda, Osamu; Kozakai, Tomokazu; Sugiyama, Yasuhiko; Oba, Hiroshi; Yasaka, Anto; Amano, Tsuyoshi; Shigemura, Hiroyuki; Suga, Osamu

2011-04-01

The next generation EUVL masks beyond hp15nm are difficult to repair for the current repair technologies including focused ion beam (FIB) and electron beam (EB) in view of the minimum repairable size. We developed a new FIB technology to repair EUVL masks. Conventional FIB use gallium ions (Ga+) generated by a liquid metal ion source (LMIS), but the new FIB uses hydrogen ions (H2+) generated by a gas field ion source (GFIS). The minimum reaction area of H2+ FIB is theoretically much smaller than that of EB. We investigated the repair performance of H2+ FIB. In the concrete, we evaluated image resolution, scan damage, etching rate, material selectivity of etching and actinic image of repaired area. The most important result is that there was no difference between the repaired area and the non-repaired one on actinic images. That result suggests that the H2+ GFIS technology is a promising candidate for the solution to repair the next generation EUVL masks beyond hp15nm.

Final Report: Conceptual Design of an Electron Accelerator for Bio-Solid Waste Treatment

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

Cooper, Charles

Several studies have identified electron beam (EB) irradiation of municipal wastewater and bio-solids as an effective and promising approach to the environmental remediation of the enormous quantities of human waste created by a growing world-wide population and increased urbanization. However, despite the technical success of experimental and pilot programs over the last several decades, the technique is still not in commercial use anywhere in the world. In addition, the report also identifies the need for “Financial and infrastructure participation from a utility for demonstration project” and “Education and awareness of safety of utilizing electron beam technology” as two additional roadblocksmore » preventing technology adoption of EB treatment for bio-solids. In this concept design, we begin to address these barriers by working with Metropolitan Water Reclamation District of Greater Chicago (MWRD) and by the applying the latest accelerator technologies developed at Fermilab and within the DOE Office of Science laboratory complex.« less

Electron-beam-induced post-grafting polymerization of acrylic acid onto the surface of Kevlar fibers

NASA Astrophysics Data System (ADS)

Xu, Lu; Hu, Jiangtao; Ma, Hongjuan; Wu, Guozhong

2018-04-01

The surface of Kevlar fibers was successfully modified by electron beam (EB)-induced post-grafting of acrylic acid (AA). The generation of radicals in the fibers was confirmed by electron spin resonance (ESR) measurements, and the concentration of radicals was shown to increase as the absorbed dose increased, but decrease with increasing temperature. The influence of the synthesis conditions on the degree of grafting was also investigated. The surface microstructure and chemical composition of the modified Kevlar fibers were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The SEM images revealed that the surface of the grafted fibers was rougher than those of the pristine and irradiated fibers. XPS analysis confirmed an increase in C(O)OH groups on the surface of the Kevlar fibers, suggesting successful grafting of AA. These results indicate that EB-induced post-grafting polymerization is effective for modifying the surface properties of Kevlar fibers.

Study of Uneven Fills to Cure the Coupled-Bunch Instability in SRRC

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

Chao, Alex W.

2002-08-12

The performance of the 1.5-GeV storage ring light source TLS in SRRC has been limited by a longitudinal coupled-bunch beam instability. To improve the performance of the TLS, the beam instability has to be suppressed. One possible way considered for the TLS to suppress its coupled-bunch instability uses uneven filling patterns according to the theory of Prabhakar[1]. By knowing the harmful high-order-modes (HOMs), a special filling pattern can be designed to utilize either mode coupling or Landau damping to cure beam instability. In TLS the HOMs are contributed from the Doris RF cavity installed in the storage ring. The HOMsmore » of a 3-D Doris cavity was numerically analyzed. Filling patterns with equal bunch current according to theory had been calculated to cure the most harmful HOM. A longitudinal particle tracking program was used to simulate the coupled-bunch beam instability with both the uniform filling and the special designed filling. Filling pattern with unequal bunch current was also studied. The results of the simulation were discussed and compared to the theory.« less

Modeling Heat and Moisture Transport in Steam-Cured Mortar: Application to Aashto Type Vi Beams.

PubMed

Hernández-Bautista, E; Sandoval-Torres, S; de J Cano-Barrita, P F; Bentz, D P

2017-10-01

During steam curing of concrete, temperature and moisture gradients are developed, which are difficult to measure experimentally and can adversely affect the durability of concrete. In this research, a model of cement hydration coupled to moisture and heat transport was used to simulate the process of steam curing of mortars with water-to-cement ( w/c ) ratios by mass of 0.30 and 0.45, considering natural convection boundary conditions in mortar and concrete specimens of AASHTO Type VI beams. The primary variables of the model were moisture content, temperature, and degree of hydration. Moisture content profiles of mortar specimens (40 mm in diameter and 50 mm in height) were measured by magnetic resonance imaging. The degree of hydration was obtained by mass-based measurements of loss on ignition to 1000 °C. The results indicate that the model correctly simulates the moisture distribution and degree of hydration in mortar specimens. Application of the model to the steam curing of an AASHTO Type VI beam indicates temperature differences (between the surface and the center) higher than 20 °C during the cooling stage, and internal temperatures higher than 70 °C that may compromise the durability of the concrete.

E-beam-Cure Fabrication of Polymer Fiber/Matrix Composites for Multifunctional Radiation Shielding

NASA Technical Reports Server (NTRS)

Wilson, John W.; Jensen, Brian J.; Thibeault, Sheila A.; Hou, Tan-Hung; Saether, Erik; Glaessgen, Edward H.; Humes, Donald H.; Chang, Chie K.; Badavi, Francis F.; Kiefer, Rrichard L.;

Barrier layers against oxygen transmission on the basis of electron beam cured methacrylated gelatin

NASA Astrophysics Data System (ADS)

Scherzer, Tom

1997-08-01

The development of barrier layers against oxygen transmission on the basis of radiation-curable methacrylated gelatin will be reported. The electron beam cured gelatin coatings show an extremely low oxygen permeability and a high resistance against boiling water. Moreover, the methacrylated gelatins possess good adhesion characteristics. Therefore, they are suited as barrier adhesives in laminates for food packaging applications. If substrate foils from biodegradable polymers are used, the development of completely biodegradable packaging materials seems to be possible.

Compatibility of martensitic/austenitic steel welds with liquid lead bismuth eutectic environment

NASA Astrophysics Data System (ADS)

Van den Bosch, J.; Almazouzi, A.

2009-04-01

The high-chromium ferritic/martensitic steel T91 and the austenitic stainless steel 316L are to be used in contact with liquid lead-bismuth eutectic (LBE), under high irradiation doses. Both tungsten inert gas (TIG) and electron beam (EB) T91/316L welds have been examined by means of metallography, scanning electron microscopy (SEM-EDX), Vickers hardness measurements and tensile testing both in inert gas and in LBE. Although the T91/316L TIG weld has very good mechanical properties when tested in air, its properties decline sharply when tested in LBE. This degradation in mechanical properties is attributed to the liquid metal embrittlement of the 309 buttering used in TIG welding of T91/316L welds. In contrast to mixed T91/316L TIG welding, the mixed T91/316L EB weld was performed without buttering. The mechanical behaviour of the T91/316L EB weld was very good in air after post weld heat treatment but deteriorated when tested in LBE.

Proximity Effect Correction by Pattern Modified Stencil Mask in Large-Field Projection Electron-Beam Lithography

NASA Astrophysics Data System (ADS)

Kobinata, Hideo; Yamashita, Hiroshi; Nomura, Eiichi; Nakajima, Ken; Kuroki, Yukinori

1998-12-01

A new method for proximity effect correction, suitable for large-field electron-beam (EB) projection lithography with high accelerating voltage, such as SCALPEL and PREVAIL in the case where a stencil mask is used, is discussed. In this lithography, a large-field is exposed by the same dose, and thus, the dose modification method, which is used in the variable-shaped beam and the cell projection methods, cannot be used in this case. In this study, we report on development of a new proximity effect correction method which uses a pattern modified stencil mask suitable for high accelerating voltage and large-field EB projection lithography. In order to obtain the mask bias value, we have investigated linewidth reduction, due to the proximity effect, in the peripheral memory cell area, and found that it could be expressed by a simple function and all the correction parameters were easily determined from only the mask pattern data. The proximity effect for the peripheral array pattern could also be corrected by considering the pattern density. Calculated linewidth deviation was 3% or less for a 0.07-µm-L/S memory cell pattern and 5% or less for a 0.14-µm-line and 0.42-µm-space peripheral array pattern, simultaneously.

Enhanced thermoelectric properties of phase-separating bismuth selenium telluride thin films via a two-step method

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

Takashiri, Masayuki, E-mail: takashiri@tokai-u.jp; Kurita, Kensuke; Hagino, Harutoshi

2015-08-14

A two-step method that combines homogeneous electron beam (EB) irradiation and thermal annealing has been developed to enhance the thermoelectric properties of nanocrystalline bismuth selenium telluride thin films. The thin films, prepared using a flash evaporation method, were treated with EB irradiation in a N{sub 2} atmosphere at room temperature and an acceleration voltage of 0.17 MeV. Thermal annealing was performed under Ar/H{sub 2} (5%) at 300 °C for 60 min. X-ray diffraction was used to determine that compositional phase separation between bismuth telluride and bismuth selenium telluride developed in the thin films exposed to higher EB doses and thermal annealing. We proposemore » that the phase separation was induced by fluctuations in the distribution of selenium atoms after EB irradiation, followed by the migration of selenium atoms to more stable sites during thermal annealing. As a result, thin film crystallinity improved and mobility was significantly enhanced. This indicates that the phase separation resulting from the two-step method enhanced, rather than disturbed, the electron transport. Both the electrical conductivity and the Seebeck coefficient were improved following the two-step method. Consequently, the power factor of thin films that underwent the two-step method was enhanced to 20 times (from 0.96 to 21.0 μW/(cm K{sup 2}) that of the thin films treated with EB irradiation alone.« less

Combined effect of high curing temperature and crack width on chloride migration in reinforced concrete beams

NASA Astrophysics Data System (ADS)

Elkedrouci, L.; Diao, B.; Pang, S.; Li, Y.

2018-03-01

Deterioration of reinforced concrete structures is a serious concern in the construction engineering, largely due to chloride induced corrosion of reinforcement. Chloride penetration is markedly influenced by one or several major factors at the same time such as cuing in combination with different crack widths which have spectacular effect on reinforced concrete structures. This research presents the results of an experimental investigation involving reinforced concrete beams with three different crack widths ranging from 0 to 0.2mm, curing temperatures of 20°C or 40°C and water-to-cement of 0.5. Chloride content profiles were determined under non-steady state diffusion at 20°C. Based on the obtained results, higher chloride content was obtained under condition of high curing temperature in combination with large crack more than 0.1mm and there are no significant differences between narrow crack width (less than 0.1 mm) and beams without crack (0 mm).

Structural, optical, and transport properties of nanocrystalline bismuth telluride thin films treated with homogeneous electron beam irradiation and thermal annealing.

PubMed

Takashiri, Masayuki; Asai, Yuki; Yamauchi, Kazuki

2016-08-19

We investigated the effects of homogeneous electron beam (EB) irradiation and thermal annealing treatments on the structural, optical, and transport properties of bismuth telluride thin films. Bismuth telluride thin films were prepared by an RF magnetron sputtering method at room temperature. After deposition, the films were treated with homogeneous EB irradiation, thermal annealing, or a combination of both the treatments (two-step treatment). We employed Williamson-Hall analysis for separating the strain contribution from the crystallite domain contribution in the x-ray diffraction data of the films. We found that strain was induced in the thin films by EB irradiation and was relieved by thermal annealing. The crystal orientation along c-axis was significantly enhanced by the two-step treatment. Scanning electron microscopy indicated the melting and aggregation of nano-sized grains on the film surface by the two-step treatment. Optical analysis indicated that the interband transition of all the thin films was possibly of the indirect type, and that thermal annealing and two-step treatment methods increased the band gap of the films due to relaxation of the strain. Thermoelectric performance was significantly improved by the two-step treatment. The power factor reached a value of 17.2 μW (cm(-1) K(-2)), approximately 10 times higher than that of the as-deposited thin films. We conclude that improving the crystal orientation and relaxing the strain resulted in enhanced thermoelectric performance.

Irradiation of wastewater with electron beam is a key to sustainable smart/green cities: a review

NASA Astrophysics Data System (ADS)

Hossain, Kaizar; Maruthi, Y. Avasn; Das, N. Lakshmana; Rawat, K. P.; Sarma, K. S. S.

2018-03-01

Remediation of wastewater, sludge and removal of objectionable substances from our environment using radiation technology is neglected. Hardly, a couple of decades ago, application of electron beam (EB) technology has gained attention for waste management. When wastewater is irradiated with electron beam, the beam can alter the physico-chemical properties of irradiated aqueous material and also transform wastewater chemicals due to the excitation or ionization of chemical molecules. Thus, chemical reactions may be capable of producing new compounds. The beam of electrons initiates primary reactions to induce the excitation or ionization of molecules at varied rates. This review paper will help to a budding researcher how to optimize the irradiation process to achieve high efficiency with low electron beam energy which is economically viable/feasible. Application of E-beam radiation for wastewater treatment may ensure future smart cities with sustainable water resources management.

Dynamic refractometer

NASA Technical Reports Server (NTRS)

Curley, Michael J. (Inventor); Sarkisov, Sergey S. (Inventor)

2008-01-01

A refractometer computer controls the rotation of a rotary plate upon which are mounted a prism optically coupled via an optical window to a spectroscopic cell holding a resin exhibiting a dynamic refractive index during photocuring. The computer system positions the prism and spectroscopic cell relative to a visible light laser which illuminates the prism-resin interface at selected incidence angles. A photodetector mounted on the plate generates a signal to the computer proportional to intensity of an internally reflected light beam. A curing light is selectively transmitted through the prism and into the photocurable resin. The refractometer determines the intensity of the internally reflected beam a selected incidence angles and determines the effective refractive index curve of the resin at an uncured state and, optionally, at a completely cured state. Next, an amount of uncured resin and selected optical components to be joined by the resin is placed in the spectroscopic cell and irradiated with the UV light. The refractometer is fixed at a selected incidence angle and measures the intensity of an internally reflected light beam of light throughout the cure cycle. The refractometer determines the resin's refractive index of the polymeric mixture by means of extrapolation of a horizontal shift in the effective refractive index curve of the resin from an uncured state to a selected point in the cure cycle.

Improvement of microbiological safety and sensorial quality of pork jerky by electron beam irradiation and by addition of onion peel extract and barbecue flavor

NASA Astrophysics Data System (ADS)

Kim, Hyun-Joo; Jung, Samooel; Yong, Hae In; Bae, Young Sik; Kang, Suk Nam; Kim, Il Suk; Jo, Cheorun

2014-05-01

The combined effects of electron-beam (EB) irradiation and addition of onion peel (OP) extract and barbecue flavor (BF) on inactivation of foodborne pathogens and the quality of pork jerky was investigated. Prepared pork jerky samples were irradiated (0, 1, 2, and 4 kGy) and stored for 2 month at 25 °C. The D10 values of Listeria monocytogenes, Escherichia coli, and Salmonella typhimurium observed in the OP treated samples were 0.19, 0.18, and 0.19 kGy, whereas those in control were 0.25, 0.23, and 0.20 kGy, respectively. Irradiated samples with OP extract and BF had substantially lower total aerobic bacterial counts than the control had. Samples with added OP extract and BF had lower peroxide values than the control had. Sensory evaluation indicated that overall acceptability of treated samples was not changed up to 2 kGy. Therefore, EB irradiation, combined with OP extract and BF, has improved the microbiological safety with no negative effects on the quality of pork jerky.

Theoretical study of fabrication of line-and-space patterns with 7 nm quarter-pitch using electron beam lithography with chemically amplified resist process: III. Post exposure baking on quartz substrates

NASA Astrophysics Data System (ADS)

Kozawa, Takahiro

2015-09-01

Electron beam (EB) lithography is a key technology for the fabrication of photomasks for ArF immersion and extreme ultraviolet (EUV) lithography and molds for nanoimprint lithography. In this study, the temporal change in the chemical gradient of line-and-space patterns with a 7 nm quarter-pitch (7 nm space width and 21 nm line width) was calculated until it became constant, independently of postexposure baking (PEB) time, to clarify the feasibility of single nano patterning on quartz substrates using EB lithography with chemically amplified resist processes. When the quencher diffusion constant is the same as the acid diffusion constant, the maximum chemical gradient of the line-and-space pattern with a 7 nm quarter-pitch did not differ much from that with a 14 nm half-pitch under the condition described above. Also, from the viewpoint of process control, a low quencher diffusion constant is considered to be preferable for the fabrication of line-and-space patterns with a 7 nm quarter-pitch on quartz substrates.

Qualitative Beam Profiling of Light Curing Units for Resin Based Composites.

PubMed

Haenel, Thomas; Hausnerová, Berenika; Steinhaus, Johannes; Moeginger, Ing Bernhard

2016-12-01

This study investigates two technically simple methods to determine the irradiance distribution of light curing units that governs the performance of a visible-light curing resin-based composites. Insufficient light irradiation leads to under-cured composites with poor mechanical properties and elution of residual monomers. The unknown irradiance distribution and its effect on the final restoration are the main critical issues requiring highly sophisticated experimental equipment. The study shows that irradiance distributions of LCUs can easily be determined qualitatively with generally available equipment. This significantly helps dentists in practices to be informed about the homogeneity of the curing lights. Copyright© 2016 Dennis Barber Ltd.

Theoretical description of transverse measurements of polarization in optically-pumped Rb vapor cells

NASA Astrophysics Data System (ADS)

Dreiling, Joan; Tupa, Dale; Norrgard, Eric; Gay, Timothy

2012-06-01

In optical pumping of alkali-metal vapors, the polarization of the atoms is typically determined by probing along the entire length of the pumping beam, resulting in an averaged value of polarization over the length of the cell. Such measurements do not give any information about spatial variations of the polarization along the pump beam axis. Using a D1 probe beam oriented perpendicular to the pumping beam, we have demonstrated a heuristic method for determining the polarization along the pump beam's axis. Adapting a previously developed theory [1], we provide an analysis of the experiment which explains why this method works. The model includes the effects of Rb density, buffer gas pressure, and pump detuning. [4pt] [1] E.B. Norrgard, D. Tupa, J.M. Dreiling, and T.J. Gay, Phys. Rev. A 82, 033408 (2010).

Line-edge quality optimization of electron beam resist for high-throughput character projection exposure utilizing atomic force microscope analysis

NASA Astrophysics Data System (ADS)

Ikeno, Rimon; Mita, Yoshio; Asada, Kunihiro

2017-04-01

High-throughput electron-beam lithography (EBL) by character projection (CP) and variable-shaped beam (VSB) methods is a promising technique for low-to-medium volume device fabrication with regularly arranged layouts, such as standard-cell logics and memory arrays. However, non-VLSI applications like MEMS and MOEMS may not fully utilize the benefits of CP method due to their wide variety of layout figures including curved and oblique edges. In addition, the stepwise shapes that appear on such irregular edges by VSB exposure often result in intolerable edge roughness, which may degrade performances of the fabricated devices. In our former study, we proposed a general EBL methodology for such applications utilizing a combination of CP and VSB methods, and demonstrated its capabilities in electron beam (EB) shot reduction and edge-quality improvement by using a leading-edge EB exposure tool, ADVANTEST F7000S-VD02, and high-resolution Hydrogen Silsesquioxane resist. Both scanning electron microscope and atomic force microscope observations were used to analyze quality of the resist edge profiles to determine the influence of the control parameters used in the exposure-data preparation process. In this study, we carried out detailed analysis of the captured edge profiles utilizing Fourier analysis, and successfully distinguish the systematic undulation by the exposed CP character profiles from random roughness components. Such capability of precise edge-roughness analysis is useful to our EBL methodology to maintain both the line-edge quality and the exposure throughput by optimizing the control parameters in the layout data conversion.

Skylab M551 metals melting experiment

NASA Technical Reports Server (NTRS)

Poorman, R. M.

1975-01-01

The objectives of the M551 Metals Melting Experiment were to: (1) study behavior of molten metal, (2) characterize metals melted and solidified in the low gravity space environment compared to one-gravity of earth, and (3) determine feasibility of joining metals in space. The experiment used the electron beam (EB) and chamber of the M512 apparatus to make a dwell puddle and a melt in a rotating disc of varying thickness. Hence, the EB performed cut-through, full and partial penetration melts, in addition to a resolidified button. The three disc materials were aluminum 2219-T87, 304 stainless steel, and pure tantalum to provide a wide range of density and melting conditions. Observations to date include the proof that EB welding, cutting, and melting can be done successfully in low gravity. Earlier, some welding authorities had postulated that without gravity the EB would force the molten puddle out of contact. However, the experiment proved that surface tension forces predominate. From the viewpoint of cast-solidification, small, equiaxed grains in Skylab specimens compared to large, elongated grains in ground based specimens were observed. The former are thought to be associated with constitutional supercooling and nucleation where the latter are associated with dendritic solidification. In further support of the more equiaxed grain growth in Skylab, symmetric subgrain patterns were frequently observed where there was much less symmetry in ground based specimens.

Micro-resonator-based electric field sensors with long durations of sensitivity

NASA Astrophysics Data System (ADS)

Ali, Amir R.

2017-05-01

In this paper, we present a new fabrication method for the whispering gallery mode (WGM) micro-sphere based electric field sensor that which allows for longer time periods of sensitivity. Recently, a WGM-based photonic electric field sensor was proposed using a coupled dielectric microsphere-beam. The external electric field imposes an electrtrostriction force on the dielectric beam, deflecting it. The beam, in turn compresses the sphere causing a shift in its WGM. As part of the fabrication process, the PDMS micro-beams and the spheres are curied at high-temperature (100oC) and subsequently poled by exposing to strong external electric field ( 8 MV/m) for two hours. The poling process allows for the deposition of surface charges thereby increasing the electrostriction effect. This methodology is called curing-then-poling (CTP). Although the sensors do become sufficiently sensitive to electric field, they start de-poling after a short period (within 10 minutes) after poling, hence losing sensitivity. In an attempt to mitigate this problem and to lock the polarization for a longer period, we use an alternate methodology whereby the beam is poled and cured simultaneously (curing-while-poling or CWP). The new fabrication method allows for the retention of polarization (and hence, sensitivity to electric field) longer ( 1500 minutes). An analysis is carried out along with preliminary experiments. Results show that electric fields as small as 100 V/m can be detected with a 300 μm diameter sphere sensor a day after poling.

Low Voltage Electron Beam Processing Final Report CRADA No. TC-645-93-A

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

Chen, H.; Wakalopulos, G.

This CRADA project was established to develop a small, inexpensive sealed-tube electron beam processing system having immediate applications in industrial, high speed manufacturing processes, and in the Department of Energy (DOE) waste treatment/cleanup operations. The technical work involved the development and demonstration of a compact, sealed, 50-75 kilovolt (kV) EB generator prototype, including controls and power supply. The specific goals of this project were to develop a low cost vacuum tube capable of shooting an electron beam several inches into the air, and to demonstrate that wide area materials processing is feasible by stacking the tubes to produce continuous beams.more » During the project, we successfully demonstrated the producibility of a low cost electron beam system and several material processing operations of interest to US industry, DOE and, since September 11, 2001, the Homeland Security.« less

Study of two different thin film coating methods in transmission laser micro-joining of thin Ti-film coated glass and polyimide for biomedical applications.

PubMed

Sultana, T; Georgiev, G L; Baird, R J; Auner, G W; Newaz, G; Patwa, R; Herfurth, H J

2009-07-01

Biomedical devices and implants require precision joining for hermetic sealing which can be achieved with low power lasers. The effect of two different thin metal film coating methods was studied in transmission laser micro-joints of titanium-coated glass and polyimide. The coating methods were cathodic arc physical vapor deposition (CA-PVD) and electron beam evaporation (EB-PVD). Titanium-coated glass joined to polyimide film can have neural electrode application. The improvement of the joint quality will be essential for robust performance of the device. Low power fiber laser (wave length = 1100 nm) was used for transmission laser micro-joining of thin titanium (Ti) film (approximately 200 nm) coated Pyrex borosilicate 7740 glass wafer (0.5 mm thick) and polyimide (Imidex) film (0.2 mm thick). Ti film acts as the coupling agent in the joining process. The Ti film deposition rate in the CA-PVD was 5-10 A/s and in the EB-PVD 1.5 A/s. The laser joint strength was measured by a lap shear test, the Ti film surfaces were analyzed by atomic force microscopy (AFM) and the lap shear tested joints were analyzed by optical microscopy and scanning electron microscopy (SEM). The film properties and the failure modes of the joints were correlated to joint strength. The CA-PVD produced around 4 times stronger laser joints than EB-PVD. The adhesion of the Ti film on glass by CA-PVD is better than that of the EB-PVD method. This is likely to be due to a higher film deposition rate and consequently higher adhesion or sticking coefficient for the CA-PVD particles arriving on the substrate compared to that of the EB-PVD film. EB-PVD shows poor laser bonding properties due to the development of thermal hotspots which occurs from film decohesion.

Contact inspection of Si nanowire with SEM voltage contrast

NASA Astrophysics Data System (ADS)

Ohashi, Takeyoshi; Yamaguchi, Atsuko; Hasumi, Kazuhisa; Ikota, Masami; Lorusso, Gian; Horiguchi, Naoto

2018-03-01

A methodology to evaluate the electrical contact between nanowire (NW) and source/drain (SD) in NW FETs was investigated with SEM voltage contrast (VC). The electrical defects were robustly detected by VC. The validity of the inspection result was verified by TEM physical observations. Moreover, estimation of the parasitic resistance and capacitance was achieved from the quantitative analysis of VC images which were acquired with different scan conditions of electron beam (EB). A model considering the dynamics of EB-induce charging was proposed to calculate the VC. The resistance and capacitance can be determined by comparing the model-based VC with experimentally obtained VC. Quantitative estimation of resistance and capacitance would be valuable not only for more accurate inspection, but also for identification of the defect point.

Odontological light-emitting diode light-curing unit beam quality.

PubMed

de Magalhães Filho, Thales Ribeiro; Weig, Karin de Mello; Werneck, Marcelo Martins; da Costa Neto, Célio Albano; da Costa, Marysilvia Ferreira

2015-05-01

The distribution of light intensity of three light-curing units (LCUs) to cure the resin-based composite for dental fillings was analyzed, and a homogeneity index [flat-top factor (FTF)] was calculated. The index is based on the M2 index, which is used for laser beams. An optical spectrum analyzer was used with an optical fiber to produce an x-y power profile of each LCU light guide. The FTF-calculated values were 0.51 for LCU1 and 0.55 for LCU2, which was the best FTF, although it still differed greatly from the perfect FTF = 1, and 0.27 for LCU3, which was the poorest value and even lower than the Gaussian FTF = 0.5. All LCUs presented notably heterogeneous light distribution, which can lead professionals and researchers to produce samples with irregular polymerization and poor mechanical properties.

Odontological light-emitting diode light-curing unit beam quality

NASA Astrophysics Data System (ADS)

de Magalhães Filho, Thales Ribeiro; Weig, Karin de Mello; Werneck, Marcelo Martins; da Costa Neto, Célio Albano; da Costa, Marysilvia Ferreira

2015-05-01

The distribution of light intensity of three light-curing units (LCUs) to cure the resin-based composite for dental fillings was analyzed, and a homogeneity index [flat-top factor (FTF)] was calculated. The index is based on the M2 index, which is used for laser beams. An optical spectrum analyzer was used with an optical fiber to produce an x-y power profile of each LCU light guide. The FTF-calculated values were 0.51 for LCU1 and 0.55 for LCU2, which was the best FTF, although it still differed greatly from the perfect FTF=1, and 0.27 for LCU3, which was the poorest value and even lower than the Gaussian FTF=0.5. All LCUs presented notably heterogeneous light distribution, which can lead professionals and researchers to produce samples with irregular polymerization and poor mechanical properties.

Electron beam-induced graft polymerization of acrylic acid and immobilization of arginine-glycine-aspartic acid-containing peptide onto nanopatterned polycaprolactone.

PubMed

Sun, Hui; Wirsén, Anders; Albertsson, Ann-Christine

2004-01-01

Electron beam- (EB-) induced graft polymerization of acrylic acid and the subsequent immobilization of arginine-glycine-aspartic acid (RGD) peptide onto nanopatterned polycaprolactone with parallel grooves is reported. A high concentration of carboxylic groups was introduced onto the polymer substrate by EB-induced polymerization of acrylic acid. In the coupling of the RGD peptide to the carboxylated polymer surface, a three-step peptide immobilization process was used. This process included the activation of surface carboxylic acid into an active ester intermediate by use of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS), the introduction of disulfide groups by use of 2-(2-pyridinyldithio)ethanamine hydrochloride (PDEA), and final immobilization of the peptide via a thiol-disulfide exchange reaction. The extent of coupling was measured by UV spectroscopy. A preliminary study of the in vitro behavior of keratinocytes (NCTC 2544) cultured on the acrylic acid-grafted and RGD peptide-coupled surface showed that most cells grown on the coupled samples had a spread-rounded appearance, while the majority of cells tended to be elongated along the grooves on uncoupled substrates.

Spin-rolling, welding, and heat treatment of aluminium 2219 for Ariane 5 GAM high pressure vessel liners

NASA Astrophysics Data System (ADS)

Radtke, W.

1992-10-01

Cylindrical liners made of Al 2219 may be spinrolled if both recrystallization and metastable precipitates can be avoided during forging or preparatory heat treatment. So welding is to be limited to circumferential joints. Pore-free welds are attainable immediately after hydroxide layer removal by diamond cutting without grease application. The EB vacuum is favorable to porosity suppression. A complete heat treatment of the liner incorporating solutionizing, water quenching and ageing leads to 100 percent weld efficiency. Pressure stabilization avoids buckling. Subsequent carbon fiber winding, curing and plastic prestressing of the liner results in an efficient high pressure vessel for hydrogen service.

Effect of calcium nitrite on the properties of concrete used in prestressed piles and beams.

DOT National Transportation Integrated Search

1992-01-01

This study evaluates the concretes in steam-cured prestressed piles and beams containing calcium nitrite as protection against chloride-induced corrosion of the steel strands and assesses their field performance over a 3-year period. Concretes contai...

Damage Tolerance of Sandwich Plates with Debonded Face Sheets

NASA Technical Reports Server (NTRS)

Avery, John L., III; Sankar, Bhavani V.

1998-01-01

Axial compression tests were performed on debonded sandwich composites made of graphite/epoxy face-sheets and aramid fiber honeycomb core. The sandwich beams were manufactured using a vacuum baccrin2 process. The face-sheet and the sandwich beam were co-cured. Delamination between one of the face sheets and the core was introduced by using a Teflon layer during the curing process. Axial compression tests were performed to determine the ultimate load carrying capacity of the debonded beams. Flatwise tension tests and Double Cantilever Beam tests were performed to determine. respectively, the strength and fracture toughness of the face-sheet/core interface. From the test results semi-empirical formulas were derived for the fracture toughness and ultimate compressive load carrying capacity in terms of the core density. core thickness. face-sheet thickness and debond length. Four different failure modes and their relation to the structural properties were identified. Linear buckling analysis was found to be inadequate in predicting the compressive load carrying capacity of the debonded sandwich composites.

Effective data compaction algorithm for vector scan EB writing system

NASA Astrophysics Data System (ADS)

Ueki, Shinichi; Ashida, Isao; Kawahira, Hiroichi

2001-01-01

We have developed a new mask data compaction algorithm dedicated to vector scan electron beam (EB) writing systems for 0.13 μm device generation. Large mask data size has become a significant problem at mask data processing for which data compaction is an important technique. In our new mask data compaction, 'array' representation and 'cell' representation are used. The mask data format for the EB writing system with vector scan supports these representations. The array representation has a pitch and a number of repetitions in both X and Y direction. The cell representation has a definition of figure group and its reference. The new data compaction method has the following three steps. (1) Search arrays of figures by selecting pitches of array so that a number of figures are included. (2) Find out same arrays that have same repetitive pitch and number of figures. (3) Search cells of figures, where the figures in each cell take identical positional relationship. By this new method for the mask data of a 4M-DRAM block gate layer with peripheral circuits, 202 Mbytes without compaction was highly compacted to 6.7 Mbytes in 20 minutes on a 500 MHz PC.

Structural Properties of EB-Welded AlSi10Mg Thin-Walled Pressure Vessels Produced by AM-SLM Technology

NASA Astrophysics Data System (ADS)

Nahmany, Moshe; Stern, Adin; Aghion, Eli; Frage, Nachum

2017-10-01

Additive manufacturing of metals by selective laser melting (AM-SLM) is hampered by significant limitations in product size due to the limited dimensions of printing trays. Electron beam welding (EBW) is a well-established process that results in relatively minor metallurgical modifications in workpieces due to the ability of EBW to pass high-density energy to the related substance. The present study aims to evaluate structural properties of EB-welded AlSi10Mg thin-walled pressure vessels produced from components prepared by SLM technology. Following the EB welding process, leak and burst tests were conducted, as was fractography analysis. The welded vessels showed an acceptable holding pressure of 30 MPa, with a reasonable residual deformation up to 2.3% and a leak rate better than 1 × 10-8 std-cc s-1 helium. The failures that occurred under longitudinal stresses reflected the presence of two weak locations in the vessels, i.e., the welded joint region and the transition zone between the vessel base and wall. Fractographic analysis of the fracture surfaces of broken vessels displayed the ductile mode of the rupture, with dimples of various sizes, depending on the failure location.

Crack prediction in EB-PVD thermal barrier coatings based on the simulation of residual stresses

NASA Astrophysics Data System (ADS)

Chen, J. W.; Zhao, Y.; Liu, S.; Zhang, Z. Z.; Ma, J.

2016-07-01

Thermal barrier coatings systems (TBCs) are widely used in the field of aerospace. The durability and insulating ability of TBCs are highly dependent on the residual stresses of top coatings, thus the investigation of the residual stresses is helpful to understand the failure mechanisms of TBCs. The simulation of residual stresses evolution in electron beam physical vapor deposition (EB-PVD) TBCs is described in this work. The interface morphology of TBCs subjected to cyclic heating and cooling is observed using scanning electron microscope (SEM). An interface model of TBCs is established based on thermal elastic-plastic finite method. Residual stress distributions in TBCs are obtained to reflect the influence of interfacial roughness. Both experimental and simulation results show that it is feasible to predict the crack location by stress analysis, which is crucial to failure prediction.

Measurement of the differential cross sections of 6Li(d,d0) for Ion Beam Analysis purposes

NASA Astrophysics Data System (ADS)

Ntemou, E.; Aslanoglou, X.; Axiotis, M.; Foteinou, V.; Kokkoris, M.; Lagoyannis, A.; Misaelides, P.; Patronis, N.; Preketes-Sigalas, K.; Provatas, G.; Vlastou, R.

2017-09-01

In the present work, the 6Li(d,d0)6Li elastic scattering differential cross sections were measured in the energy range Ed,lab = 940-2000 keV for Elastic Backscattering Spectroscopy (EBS) purposes, using thin lithium targets, made by evaporating isotopically enriched 6LiF powder on self-supporting carbon foils, with an ultra-thin Au layer on top for normalization purposes. The experiment was carried out in deuteron beam energy steps of 20 or 30 keV and for the laboratory scattering angles of 125°, 140°, 150°, 160°, and 170°.

A study on the swelling behavior of poly(acrylic acid) hydrogels obtained by electron beam crosslinking

NASA Astrophysics Data System (ADS)

Sheikh, N.; Jalili, L.; Anvari, F.

2010-06-01

Poly(acrylic acid) (PAA) hydrogels were prepared by using electron beam (EB) crosslinking of PAA homopolymer from its aqueous solutions. The swelling behavior of the hydrogels was studied as a function of the concentration of PAA solution, radiation dose, pH of the swelling medium and swelling time. Also the environmental pH effect on the water diffusion mode into hydrogels was investigated. These hydrogels clearly showed pH-sensitive swelling behavior with Fickian type of diffusion in the stomach-like pH medium (pH 1.3) and non-Fickian type in the intestine-like pH medium (pH 6.8).

Modeling study of polychlorinated dibenzo-p-dioxins and dibenzofurans behavior in flue gases under electron beam irradiation.

PubMed

Gerasimov, Gennady

2016-09-01

The efficiency of the electron beam treatment of industrial flue gases for the removal of sulfur and nitrogen oxides was investigated as applied to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) using methods of mathematical modeling. The proposed kinetic model of the process includes mechanism of PCDD/Fs decomposition caused by their interaction with OH radicals generated in the flue gases under the electron beam (EB) irradiation as well as PCDD/Fs formation from unburned aromatic compounds. The model allows to predict the main features of the process, which are observed in pilot plant installations, as well as to evaluate the process efficiency. The results of calculations are compared with the available experimental data. Copyright © 2016 Elsevier Ltd. All rights reserved.

Disinfection and reduction of organic load of sewage water by electron beam radiation

NASA Astrophysics Data System (ADS)

Maruthi, Y. Avasn; Das, N. Lakshmana; Hossain, Kaizar; Sarma, K. S. S.; Rawat, K. P.; Sabharwal, S.

2011-09-01

The efficacy of electron beam radiation for the disinfection and reduction of organic load of sewage water was assessed with ILU-6 Accelerator at Radiation Technology Development Division of the Bhabha Atomic Research Centre, Mumbai India. The current problem on environmental health in relation to water pollution insists for the safe disposal of sewage water. In general, sewage water comprises heterogeneous organic based chemicals as well as pathogens. EB treatment of the wastewater has found to be very effective in reducing the pathogens as well as organic load. EB dose of 1.5 kGy was sufficient for complete elimination of total coli forms. The experimental results elucidated the reduction of biological oxygen demand—BOD (35 and 51.7%) in both inlet and outlet sewage samples. Similarly reduction of chemical oxygen demand—COD was observed (37.54 and 52.32%) in both sewage samples with respect to increase in irradiation doses (0.45-6 kGy). The present study demonstrated the potential of ionizing radiation for disinfection of sewage and to increase the water quality of the wastewater by decreasing BOD and COD. So, the irradiation sewage water can find its application either in agriculture for irrigation, in industry for cooling purpose and some selected domestic purposes.

Electron beam physical vapor deposition of YSZ electrolyte coatings for SOFCs

NASA Astrophysics Data System (ADS)

He, Xiaodong; Meng, Bin; Sun, Yue; Liu, Bochao; Li, Mingwei

2008-09-01

YSZ electrolyte coatings were prepared by electron beam physical vapor deposition (EB-PVD) at a high deposition rate of up to 1 μm/min. The YSZ coating consisted of a single cubic phase and no phase transformation occurred after annealing treatment at 1000 °C. A typical columnar structure was observed in this coating by SEM and feather-like characteristics appeared in every columnar grain. In columnar grain boundaries there were many micron-sized gaps and pores. In TEM image, many white lines were found, originating from the alignment of nanopores existing within feather-like columnar grains. The element distribution along the cross-section of the coating was homogeneous except Zr with a slight gradient. The coating exhibited a characteristic anisotropic behavior in electrical conductivity. In the direction perpendicular to coating surface the electrical conductivity was remarkably higher than that in the direction parallel to coating surface. This mainly attributed to the typical columnar structure for EB-PVD coating and the existence of many grain boundaries along the direction parallel to coating surface. For as-deposited coating, the gas permeability coefficient of 9.78 × 10 -5 cm 4 N -1 s -1 was obtained and this value was close to the critical value of YSZ electrolyte layer required for solid oxide fuel cell (SOFC) operation.

Comparison of mathematic models for assessment of glomerular filtration rate with electron-beam CT in pigs.

PubMed

Daghini, Elena; Juillard, Laurent; Haas, John A; Krier, James D; Romero, Juan C; Lerman, Lilach O

2007-02-01

To prospectively compare in pigs three mathematic models for assessment of glomerular filtration rate (GFR) on electron-beam (EB) computed tomographic (CT) images, with concurrent inulin clearance serving as the reference standard. This study was approved by the institutional animal care and use committee. Inulin clearance was measured in nine pigs (18 kidneys) and compared with single-kidney GFR assessed from renal time-attenuation curves (TACs) obtained with EB CT before and after infusion of the vasodilator acetylcholine. CT-derived GFR was calculated with the original and modified Patlak methods and with previously validated extended gamma variate modeling of first-pass cortical TACs. Statistical analysis was performed to assess correlation between CT methods and inulin clearance for estimation of GFR with least-squares regression analysis and Bland-Altman graphical representation. Comparisons within groups were performed with a paired t test. GFR assessed with the original Patlak method indicated poor correlation with inulin clearance, whereas GFR assessed with the modified Patlak method (P < .001, r = 0.75) and with gamma variate modeling (P < .001, r = 0.79) correlated significantly with inulin clearance and indicated an increase in response to acetylcholine. CT-derived estimates of GFR can be significantly improved by modifications in image analysis methods (eg, use of a cortical region of interest). (c) RSNA, 2007.

Investigation of failure mechanism of thermal barrier coatings (TBCs) deposited by EB-PVD technique

NASA Astrophysics Data System (ADS)

Shahid, M. R.; Abbas, Musharaf

2013-06-01

Failure mechanism of thermal barrier coatings (TBCs) prepared by electron beam physical vapor deposition (EB-PVD) technique owing to formation of micro cracks was investigated. The TBCs were deposited on the Ni-based super alloy IN-100 and the micro cracks were observed within the top ceramic coat of thermally cycled TBCs at 1050°C. It was observed that these cracks propagate in the ceramic coat in the direction normal to interface while no cracks were observed in the bond coat. SEM/EDS studies revealed that some non-uniform oxides were formed on the interface between ceramic top and metallic bond coat just below the cracks. Study proposed that the cracks were initiated due to stress owing to big difference in Pilling-Bed worth ratio of non-uniform oxides as well as thermal stress, which caused the formation of cracks in top ceramic coat leading to failure of TBCs

Effects of LEO Environment on Tensile Properties of PEEK Films

NASA Astrophysics Data System (ADS)

Nakamura, Takashi; Nakamura, Hiroshi; Shimamura, Hiroyuki

2009-01-01

To clarify the effects of space environment on mechanical properties of polymer, exposure experiments were conducted utilizing the International Space Station Russian Service Module. Poly-ether-ether-ketone (PEEK) films under tensile stress were exposed to low Earth orbit (LEO) environment, and reference samples were irradiated with atomic oxygen (AO), electron beam (EB), and ultraviolet light (UV) in ground facilities. By comparing the results of flight and ground tests, the degradation behavior and the influential factors in LEO were investigated. The following results were obtained. (1) UV was found to be the harshest factor in LEO on tensile properties, since it decreased elongation to 15% of pristine sample after 46-months exposure. (2) AO in LEO eroded the specimen surface with a cone-like morphology and reduced the thickness; however, it had no significant effect on tensile properties. (3) EB irradiation in LEO had no measurable effects on the material properties.

Structural and growth aspects of electron beam physical vapor deposited NiO-CeO{sub 2} nanocomposite films

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

Kuanr, Sushil Kumar; K, Suresh Babu, E-mail: sureshbabu.nst@pondiuni.edu.in

2016-03-15

Deposition of composite materials as thin film by electron beam physical vapor deposition technique (EB-PVD) still remains as a challenge. Here, the authors report the deposition of NiO-CeO{sub 2} (30/70 wt. %) composites on quartz substrate by EB-PVD. Two NiO-CeO{sub 2} nanocomposite targets—one as green compact and the other after sintering at 1250 °C—were used for the deposition. Though the targets varied with respect to physical properties such as crystallite size (11–45 nm) and relative density (44% and 96%), the resultant thin films exhibited a mean crystallite size in the range of 20–25 nm underlining the role of physical nature of deposition. In spitemore » of the crystalline nature of the targets and similar elemental concentration, a transformation from amorphous to crystalline structure was observed in thin films on using sintered target. Postannealing of the as deposited film at 800 °C resulted in a polycrystalline structure consisting of CeO{sub 2} and NiO. Deposition using pure CeO{sub 2} or NiO as target resulted in the preferential orientation toward (111) and (200) planes, respectively, showing the influence of adatoms on the evaporation and growth process of NiO-CeO{sub 2} composite. The results demonstrate the influence of electron beam gun power on the adatom energy for the growth process of composite oxide thin films.« less

Effect of Suspension Plasma-Sprayed YSZ Columnar Microstructure and Bond Coat Surface Preparation on Thermal Barrier Coating Properties

NASA Astrophysics Data System (ADS)

Bernard, Benjamin; Quet, Aurélie; Bianchi, Luc; Schick, Vincent; Joulia, Aurélien; Malié, André; Rémy, Benjamin

2017-08-01

Suspension plasma spraying (SPS) is identified as promising for the enhancement of thermal barrier coating (TBC) systems used in gas turbines. Particularly, the emerging columnar microstructure enabled by the SPS process is likely to bring about an interesting TBC lifetime. At the same time, the SPS process opens the way to a decrease in thermal conductivity, one of the main issues for the next generation of gas turbines, compared to the state-of-the-art deposition technique, so-called electron beam physical vapor deposition (EB-PVD). In this paper, yttria-stabilized zirconia (YSZ) coatings presenting columnar structures, performed using both SPS and EB-PVD processes, were studied. Depending on the columnar microstructure readily adaptable in the SPS process, low thermal conductivities can be obtained. At 1100 °C, a decrease from 1.3 W m-1 K-1 for EB-PVD YSZ coatings to about 0.7 W m-1 K-1 for SPS coatings was shown. The higher content of porosity in the case of SPS coatings increases the thermal resistance through the thickness and decreases thermal conductivity. The lifetime of SPS YSZ coatings was studied by isothermal cyclic tests, showing equivalent or even higher performances compared to EB-PVD ones. Tests were performed using classical bond coats used for EB-PVD TBC coatings. Thermal cyclic fatigue performance of the best SPS coating reached 1000 cycles to failure on AM1 substrates with a β-(Ni,Pt)Al bond coat. Tests were also performed on AM1 substrates with a Pt-diffused γ-Ni/γ'-Ni3Al bond coat for which more than 2000 cycles to failure were observed for columnar SPS YSZ coatings. The high thermal compliance offered by both the columnar structure and the porosity allowed the reaching of a high lifetime, promising for a TBC application.

Flexural behaviour of RCC beams with externally bonded FRP

NASA Astrophysics Data System (ADS)

Vignesh, S. Arun; Sumathi, A.; Saravana Raja Mohan, K.

2017-07-01

The increasing use of carbon and glass fibre reinforced polymer (FRP) sheets for strengthening existing reinforced concrete beams has generated considerable interest in understanding the behavior of the FRP sheets when subjected to bending. The study on flexure includes various parameters like percentage of increase in strength of the member due to the externally bonded Fiber reinforced polymer, examining the crack patterns, reasons of debonding of the fibre from the structure, scaling, convenience of using the fibres, cost effectiveness etc. The present work aims to study experimentally about the reasons behind the failure due to flexure of an EB-FRP concrete beam by studying the various parameters. Deflection control may become as important as flexural strength for the design of FRPreinforced concrete structures. A numerical model is created using FEM software and the results are compared with that of the experiment.

Extended biofilm susceptibility assay for Staphylococcus aureus bovine mastitis isolates: evidence for association between genetic makeup and biofilm susceptibility.

PubMed

Melchior, M B; van Osch, M H J; Lam, T J G M; Vernooij, J C M; Gaastra, W; Fink-Gremmels, J

2011-12-01

Staphylococcus aureus is one of the most prevalent causes of bovine mastitis. The antimicrobial treatment of this disease is currently based on antimicrobial susceptibility tests according to Clinical and Laboratory Standards Institute standards. However, various authors have shown a discrepancy between the results of this standard susceptibility test and the actual cure rate of the applied antimicrobial treatment. Increasing evidence suggests that in vivo biofilm formation by Staph. aureus, which is not assessed in the antimicrobial susceptibility tests, is associated with this problem, resulting in disappointing cure rates, especially for infections of longer duration. Previous data obtained with a limited number of strains showed that the extended biofilm antimicrobial susceptibility (EBS) assay reveals differences between strains, which cannot be derived from a standard susceptibility test or from a 24-h biofilm susceptibility test. The objective of this study was to test a collection of Staph. aureus bovine mastitis strains in the EBS assay and to model the effect of antimicrobial exposure, duration of antimicrobial exposure, and genotype profile of the strains on antimicrobial susceptibility. With the results from a previous study with the same collection of strains, the effect of genotype represented by accessory gene regulator gene (agr-type), the presence of insertional sequence 257 (IS257), intercellular adhesion (ica), and the β-lactamase (blaZ) gene were entered as explanatory factors in a logistic regression model. The agr locus of Staph. aureus controls the expression of most of the virulence factors, represses the transcription of several cell wall-associated proteins, and activates several exoproteins during the post-exponential phase. The IS257 gene has been related to biofilm formation in vitro and was found earlier in 50% of the agr-type 2 strains. The ica gene cluster encodes for the production of an extracellular polysaccharide adhesin, termed polysaccharide intercellular adhesin, which appears to have an important role in pathogenic Staph. aureus infections. The blaZ gene encodes the presence of the penicillin resistance in the strain. The EBS assay together with the logistic regression model revealed that the duration of therapy is the most important factor of therapy outcome in this in vitro model. Furthermore, the effect of genotypic differences seems to be more important for therapy outcome than the antimicrobial used in this model. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Exploratory study on the effects of novel diamine curing agents and isocyanate precursors on the properties on new epoxy and urethane adhesives

NASA Technical Reports Server (NTRS)

Glasgow, D. G.; Garthwait, C.

1977-01-01

Aromatic diamines based on diphenyl sulfone and benzophenone were studied as epoxy adhesive curing agents. Previously found differences in adhesive strengths for meta vs para orientation were not found in these series. The use of aluminum and alumina as fillers in a m,m prime-methylene dianiline-cured epoxy adhesive was not found to be beneficial to adhesive strength. Alumina filled adhesives had much lower strength than unfilled adhesives. The unfilled m,m prime-methylene dianiline-based epoxy adhesive had excellent resistance to moisture relative to a p,p prime-methylene dianiline-based adhesive and maintained good strengths up to 250 F. A glass fiber composite based on a m,m prime-methylene dianiline-cured epoxy appeared to be equivalent to the p,p prime-methylene dianiline-cured epoxy as judged by short beam shear tests.

Checking collagen preservation in archaeological bone by non-destructive studies (Micro-CT and IBA)

NASA Astrophysics Data System (ADS)

Beck, L.; Cuif, J.-P.; Pichon, L.; Vaubaillon, S.; Dambricourt Malassé, A.; Abel, R. L.

2012-02-01

The material to be studied is a piece of human skull discovered (1999) in Pleistocene sediments from the Orsang river (Gujarat state, India). From anatomical view point, this skull is highly composite: modern Homo sapiens characters are associated to undoubtedly more ancient features. Absolute dating by 14C is critical to understand this discovery. Prior to dating measurements, non-destructive studies have been carried out. Micro-CT reconstruction (X-ray microtomography) and Ion Beam Analysis (IBA) have been undertaken to check the structural preservation of the fossil and the collagen preservation. PIXE elemental map was used to select well-preserved bone area. RBS/EBS and NRA were used for light element quantification, in particular C, N and O contents. We also demonstrate that the PIXE-RBS/EBS combination is a effective tool for the whole characterization of archaeological and recent bones by analysing in one experiment both mineral and organic fractions. We have shown that the archaeological bone, a fragment of the potentially oldest modern Indian, is enough preserved for radiocarbon dating. We propose that Elastic Backscattering Spectrometry (EBS) using 3 MeV protons could be a good non destructive alternative to conventional CHN method using Carbon-Hydrogen-Nitrogen analyzer for measuring C and N before 14C dating.

Assessment of Cyclic Lifetime of NiCoCrAlY/ZrO2-Based EB-PVD TBC Systems via Reactive Element Enrichment in the Mixed Zone of the TGO Scale

NASA Astrophysics Data System (ADS)

Fritscher, Klaus; Braue, Wolfgang; Schulz, Uwe

2013-05-01

The chemical composition of the alumina-zirconia mixed zone (MZ) of an electron beam physical vapor deposited thermal barrier coating (EB-PVD TBC) system is affected by service conditions and by the interdiffusion of elements from the substrate alloy below and the zirconia top coat. Three NiCoCrAlY bond-coated Ni-base substrates with YPSZ or CeSZ EB-PVD TBCs were subjected to a cyclic furnace oxidation test (FCT) at 1373 K (1100 °C) in order to provide experimental evidence of a link between chemistry of the MZ, the substrate alloy, the ceramic top coat, and the time in the FCT. Energy dispersive spectroscopy of the MZ revealed preferred accumulation of Cr, Zr, Y, and Ce. The concentration of the reactive elements (RE = Ce + Y + Zr) was related to the respective average lifetimes of the TBC systems at 1373 K (1100 °C). The RE content in the MZ turned out to be a life-limiting parameter for YPSZ and CeSZ TBC systems which can be utilized to predict their relative lifetimes on the individual substrates. Conversely, the TBC failure mechanisms of YPSZ and CeSZ TBC systems are dissimilar.

Evaluation of flow properties in the weldments of vanadium alloys using a novel indentation technique

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

Gubbi, A.N.; Rowcliffe, A.F.; Lee, E.H.

1996-10-01

Automated Ball Indentation (ABI) testing, was successfully employed to determine the flow properties of the fusion zone, heat affected zone (HAZ), and base metal of the gas tungsten arc (GTA) and electron beam (EB) welds of the V-4Cr-4Ti (large heat no. 832665) and the V-5Cr-5Ti (heat 832394) alloys. ABI test results showed a clear distinction among the properties of the fusion zone, HAZ, and base metal in both GTA and EB welds of the two alloys. GTA and EB welds of both V-4Cr-4Ti and V-5Cr-5Ti alloys show strengthening of both the fusion zone and the HAZ (compared to base metal)more » with the fusion zone having higher strength than the HAZ. These data correlate well with the Brinell hardness. On the other hand, GTA welds of both alloys, after a post-weld heat treatment of 950{degrees}C for 2 h, show a recovery of the properties to base metal values with V-5Cr-5Ti showing a higher degree of recovery compared to V-4Cr-4Ti. These measurements correlate with the reported recovery of the Charpy impact properties.« less

Portable Electron-Beam Free-Form Fabrication System

NASA Technical Reports Server (NTRS)

Watson, J. Kevin; Petersen, Daniel D.; Taminger, Karen M.; Hafley, Robert A.

2005-01-01

A portable electron-beam free-form fabrication (EB F3) system, now undergoing development, is intended to afford a capability for manufacturing metal parts in nearly net sizes and shapes. Although the development effort is oriented toward the eventual use of systems like this one to supply spare metal parts aboard spacecraft in flight, the basic system design could also be adapted to terrestrial applications in which there are requirements to supply spare parts on demand at locations remote from warehouses and conventional manufacturing facilities. Prior systems that have been considered for satisfying the same requirements (including prior free-form fabrication systems) are not easily portable because of their bulk and massive size. The mechanical properties of the components that such systems produce are often inferior to the mechanical properties of the corresponding original, conventionally fabricated components. In addition, the prior systems are not efficient in the utilization of energy and of feedstock. In contrast, the present developmental system is designed to be sufficiently compact and lightweight to be easily portable, to utilize both energy and material more efficiently, and to produce components that have mechanical properties approximating those of the corresponding original components. The developmental EB F3 system will include a vacuum chamber and associated vacuum pumps, an electron-beam gun and an associated power supply, a multiaxis positioning subsystem, a precise wire feeder, and an instrumentation system for monitoring and control. The electron-beam gun, positioning subsystem, and wire feeder will be located inside the vacuum chamber (see figure). The electron beam gun and the wire feeder will be mounted in fixed positions inside the domed upper portion of the vacuum chamber. The positioning subsystem and ports for the vacuum pumps will be located on a base that could be dropped down to provide full access to the interior of the chamber when not under vacuum. During operation, wire will be fed to a fixed location, entering the melted pool created by the electron beam. Heated by the electron beam, the wire will melt and fuse to either the substrate or with the previously deposited metal wire fused on top of the positioning table. Based on a computer aided design (CAD) model and controlled by a computer, the positioning subsystem

The effect of ultra-violet light curing on the molecular structure and fracture properties of an ultra low-k material

NASA Astrophysics Data System (ADS)

Smith, Ryan Scott

As the gate density increases in microelectronic devices, the interconnect delay or RC response also increases and has become the limiting delay to faster devices. In order to decrease the RC time delay, a new metallization scheme has been chosen by the semiconductor industry. Copper has replaced aluminum as the metal lines and new low-k dielectric materials are being developed to replace silicon dioxide. A promising low-k material is porous organosilicate glass or p-OSG. The p-OSG film is a hybrid material where the silicon dioxide backbone is terminated with methyl or hydrogen, reducing the dielectric constant and creating mechanically weak films that are prone to fracture. A few methods of improving the mechanical properties of p-OSG films have been attempted-- exposing the film to hydrogen plasma, electron beam curing, and ultra-violet light curing. Hydrogen plasma and electron-beam curing suffer from a lack of specificity and can cause charging damage to the gates. Therefore, ultra-violet light curing (UV curing) is preferable. The effect of UV curing on an ultra-low-k, k~2.5, p-OSG film is studied in this dissertation. Changes in the molecular structure were measured with Fourier Transform Infrared Spectroscopy and X-ray Photoelectron Spectroscopy. The evolution of the molecular structure with UV curing was correlated with material and fracture properties. The material properties were film shrinkage, densification, and an increase in dielectric constant. From the changes in molecular structure and material properties, a set of condensation reactions with UV light are predicted. The connectivity of the film increases with the condensation reactions and, therefore, the fracture toughness should also increase. The effect of UV curing on the critical and sub-critical fracture toughness was also studied. The critical fracture toughness was measured at four different mode-mixes-- zero, 15°, 32°, and 42°. It was found that the critical fracture toughness increases with UV exposure for all mode mixes. The sub-critical fracture toughness was measured in Mode I and found to be insensitive to UV cure. A simple reaction rate model is used to explain the difference in critical and sub-critical fracture toughness.

ELECTRON CLOUD OBSERVATIONS AND CURES IN RHIC

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

FISCHER,W.; BLASKIEWICZ, M.; HUANG, H.

Since 2001 RHIC has experienced electron cloud effects, which have limited the beam intensity. These include dynamic pressure rises - including pressure instabilities, tune shifts, a reduction of the stability threshold for bunches crossing the transition energy, and possibly incoherent emittance growth. We summarize the main observations in operation and dedicated experiments, as well as countermeasures including baking, NEG coated warm beam pipes, solenoids, bunch patterns, anti-grazing rings, pre-pumped cold beam pipes, scrubbing, and operation with long bunches.

Experimental Study on Full-Scale Beams Made by Reinforced Alkali Activated Concrete Undergoing Flexure.

PubMed

Monfardini, Linda; Minelli, Fausto

2016-08-30

Alkali Activated Concrete (AAC) is an alternative kind of concrete that uses fly ash as a total replacement of Portland cement. Fly ash combined with alkaline solution and cured at high temperature reacts to form a binder. Four point bending tests on two full scale beams made with AAC are described in this paper. Companion small material specimens were also casted with the aim of properly characterizing this new tailored material. The beam's length was 5000 mm and the cross section was 200 mm × 300 mm. The AAC consisted of fly ash, water, sand 0-4 mm and coarse aggregate 6-10 mm; and the alkaline solution consisted of sodium hydroxide mixed with sodium silicate. No cement was utilized. The maximum aggregate size was 10 mm; fly ash was type F, containing a maximum calcium content of 2%. After a rest period of two days, the beam was cured at 60 °C for 24 h. Data collected and critically discussed included beam deflection, crack patterns, compressive and flexural strength and elastic modulus. Results show how AAC behavior is comparable with Ordinary Portland Cement (OPC) based materials. Nonlinear numerical analyses are finally reported, promoting a better understanding of the structural response.

Tetraglycidyl epoxy resins and graphite fiber composites cured with flexibilized aromatic diamines

NASA Technical Reports Server (NTRS)

Delvigs, P.

1986-01-01

Studies were performed to synthesize new ether modified, flexibilized aromatic diamine hardeners for curing epoxy resins. The effect of moisture absorption on the glass transition temperatures of a tetraglycidyl epoxy, MY 720, cured with flexibilized hardeners and a conventional aromatic diamine was studied. Unidirectional composites, using epoxy-sized Celion 6000 graphite fiber as the reinforcement, were fabricated. The room temperature and 300 F mechanical properties of the composites, before and after moisture exposure, were determined. The Mode I interlaminar fracture toughness of the composites was characterized using a double cantilever beam technique to calculate the critical strain energy release rate.

Radiation response of industrial materials: Dose-rate and morphology implications

NASA Astrophysics Data System (ADS)

Berejka, Anthony J.

2007-08-01

Industrial uses of ionizing radiation mostly rely upon high current, high dose-rate (100 kGy/s) electron beam (EB) accelerators. To a lesser extent, industry uses low dose-rate (2.8 × 10-3 kGy/s) radioactive Cobalt-60 as a gamma source, generally for some rather specific purposes, as medical device sterilization and the treatment of food and foodstuffs. There are nearly nine times as many (∼1400) high current EB units in commercial operation than gamma sources (∼160). However, gamma sources can be easily scaled-down so that much research on materials effects is conducted using gamma radiation. Likewise, laboratories are more likely to have very low beam current and consequently low dose-rate accelerators such as Van de Graaff generators and linear accelerators. With the advent of very high current EB accelerators, X-ray processing has become an industrially viable option. With X-rays from high power sources, dose-rates can be modulated based upon accelerator power and the attenuation of the X-ray by the distance of the material from the X-ray target. Dose and dose-rate dependence has been found to be of consequence in several commercial applications which can employ the use of ionizing radiation. The combination of dose and dose-rate dependence of the polymerization and crosslinking of wood impregnants and of fiber composite matrix materials can yield more economically viable results which have promising commercial potential. Monomer and oligomer structure also play an important role in attaining these desirable results. The influence of morphology is shown on the radiation response of olefin polymers, such as ethylene, propylene and isobutylene polymers and their copolymers. Both controlled morphology and controlled dose-rate have commercial consequences. These are also impacted both by the adroit selection of materials and through the possible use of X-ray processing.

Real-Time In-situ Characterization of Electron-Beam-Induced Bulk Polymerizations

DTIC Science & Technology

2005-09-30

work has shown that multiwall carbon nanotubes ( MWCNT ) can be modified using dry processes (EB irradiation in air) and that the degree of modification...activated monomer species (a) and the formation of a new alcohol moiety with the regeneration of a new activated monomer (b) followed by the reaction of...thought to result from the slow regeneration of active centers and the generation of alcohol moieties from these ring structures as water reacts to

Prospect of EUV mask repair technology using e-beam tool

NASA Astrophysics Data System (ADS)

Kanamitsu, Shingo; Hirano, Takashi; Suga, Osamu

2010-09-01

Currently, repair machines used for advanced photomasks utilize principle method like as FIB, AFM, and EB. There are specific characteristic respectively, thus they have an opportunity to be used in suitable situation. But when it comes to EUV generation, pattern size is so small highly expected as under 80nm that higher image resolution and repair accuracy is needed for its machines. Because FIB machine has intrinsic damage problem induced by Ga ion and AFM machine has critical tip size issue, those machines are basically difficult to be applied for EUV generation. Consequently, we focused on EB repair tool for research work. EB repair tool has undergone practical milestone about MoSi based masks. We have applied same process which is used for MoSi to EUV blank and confirmed its reaction. Then we found some severe problems which show uncontrollable feature due to its enormously strong reaction between etching gas and absorber material. Though we could etch opaque defect with conventional method and get the edge shaped straight by top-down SEM viewing, there were problems like as sidewall undercut or local erosion depending on defect shape. In order to cope with these problems, the tool vender has developed a new process and reported it through an international conference [1]. We have evaluated the new process mentioned above in detail. In this paper, we will bring the results of those evaluations. Several experiments for repair accuracy, process stability, and other items have been done under estimation of practical condition assuming diversified size and shape defects. A series of actual printability tests will be also included. On the basis of these experiments, we consider the possibility of EB-repair application for 20nm pattern.

Relation of Thermal Conductivity with Process Induced Anisotropic Void Systems in EB-PVD PYSZ Thermal Barrier Coatings

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

Renteria, A. Flores; Saruhan-Brings, B.; Ilavsky, J.

2008-03-03

Thermal barrier coatings (TBCs) deposited by Electron-beam physical deposition (EB-PVD) protect the turbine blades situated at the high pressure sector of the aircraft and stationary turbines. It is an important task to uphold low thermal conductivity in TBCs during long-term service at elevated temperatures. One of the most promising methods to fulfil this task is to optimize the properties of PYSZ-based TBC by tailoring its microstructure. Thermal conductivity of the EB-PVD produced PYSZ TBCs is influenced mainly by the size, shape, orientation and volume of the various types of porosity present in the coatings. These pores can be classified asmore » open (inter-columnar and between feather arms gaps) and closed (intra-columnar pores). Since such pores are located within the three-dimensionally deposited columns and enclose large differences in their sizes, shapes, distribution and anisotropy, the accessibility for their characterization is very complex and requires the use of sophisticated methods. In this work, three different EB-PVD TBC microstructures were manufactured by varying the process parameters, yielding various characteristics of their pores. The corresponding thermal conductivities in as-coated state and after ageing at 11000C/1h and 100h were measured via Laser Flash Analysis Method (LFA). The pore characteristics and their individual effect on the thermal conductivity are analysed by USAXS which is supported by subsequent modelling and LFA methods, respectively. Evident differences in the thermal conductivity values of each microstructure were found in as-coated and aged conditions. In summary, broader columns introduce higher values in thermal conductivity. In general, thermal conductivity increases after ageing for all three investigated microstructures, although those with initial smaller pore surface area show smaller changes.« less

Relation of thermal conductivity with process induced anisotropic void system in EB-PVD PYSZ thermal barrier coatings.

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

Renteria, A. F.; Saruhan, B.; Ilavsky, J.

2007-01-01

Thermal barrier coatings (TBCs) deposited by Electron-beam physical deposition (EB-PVD) protect the turbine blades situated at the high pressure sector of the aircraft and stationary turbines. It is an important task to uphold low thermal conductivity in TBCs during long-term service at elevated temperatures. One of the most promising methods to fulfil this task is to optimize the properties of PYSZ-based ,TBC by tailoring its microstructure. Thermal conductivity of the EB-PVD produced PYSZ TBCs is influenced mainly by the size, shape, orientation and volume of the various types of porosity present in the coatings. These pores can be classified asmore » open (inter-columnar and between feather arms gaps) and closed (intra-columnar pores). Since such pores are located within the three-dimensionally deposited columns and enclose large differences in their sizes, shapes, distribution and anisotropy, the accessibility for their characterization is very complex and requires the use of sophisticated methods. In this work, three different EB-PVD TBC microstructures were manufactured by varying the process parameters, yielding various characteristics of their pores. The corresponding thermal conductivities in as-coated state and after ageing at 1100C/1h and 100h were measured via Laser Flash Analysis Method (LFA). The pore characteristics and their individual effect on the thermal conductivity are analysed by USAXS which is supported by subsequent modelling and LFA methods, respectively. Evident differences in the thermal conductivity values of each microstructure were found in as-coated and aged conditions. In summary, broader columns introduce higher values in thermal conductivity. In general, thermal conductivity increases after ageing for all three investigated microstructures, although those with initial smaller pore surface area show smaller changes.« less

Critical analysis of industrial electron accelerators

NASA Astrophysics Data System (ADS)

Korenev, S.

2004-09-01

The critical analysis of electron linacs for industrial applications (degradation of PTFE, curing of composites, modification of materials, sterlization and others) is considered in this report. Main physical requirements for industrial electron accelerators consist in the variations of beam parameters, such as kinetic energy and beam power. Questions for regulation of these beam parameters are considered. The level of absorbed dose in the irradiated product and throughput determines the main parameters of electron accelerator. The type of ideal electron linac for industrial applications is discussed.

Study on potential of carbon dioxide absorption in reinforced concrete beams

NASA Astrophysics Data System (ADS)

Bambroo, Vibhas; Gupta, Shipali; Bhoite, Pratik; Sekar, S. K.

2017-11-01

The global gas emission is keeping on increasing for which cement industry alone contributes 5%. The enormous water is required for curing of concrete in construction industry which can effectively be used for various purposes. The accelerated carbonation curing shows a way to reduce these emissions in a very effective way by sequestering it in concrete elements. In this research the effect of accelerated carbonation curing was checked on non-reinforced concrete elements (cubes) and reinforced concrete elements (prisms). The 100mm × 100mm × 100 mm cubes and 150mm × 150mm × 1200mm prisms were cast. They were CO2 cured for 4 and 8 hours and were tested for compressive strength and flexural strength test. The CO2 curing results showed 27.7% and 1.8% increase in strength of cubes and prisms, respectively when compared to water cured specimens. This early age strength through waste gas proves beneficial in terms of reducing in atmospheric pollution and saving the water which is a critical resource now-a-days.

Polymer Matrix Composite Lines and Ducts

NASA Technical Reports Server (NTRS)

Nettles, A. T.

2001-01-01

Since composite laminates are beginning to be identified for use in reusable launch vehicle propulsion systems, a task was undertaken to assess the feasibility of making cryogenic feedlines with integral flanges from polymer matrix composite materials. An additional level of complexity was added by having the feedlines be elbow shaped. Four materials, each with a unique manufacturing method, were chosen for this program. Feedlines were to be made by hand layup (HLU) with standard autoclave cure, HLU with electron beam cure, solvent-assisted resin transfer molding (SARTM), and thermoplastic tape laying (TTL). A test matrix of fill and drain cycles with both liquid nitrogen and liquid helium, along with a heat up to 250 F, was planned for each of the feedlines. A pressurization to failure was performed on any feedlines that passed the cryogenic cycling testing. A damage tolerance subtask was also undertaken in this study. The effects of foreign object impact to the materials used was assessed by cross-sectional examination and by permeability after impact testing. At the end of the program, the manufacture of the electron beam-cured feedlines never came to fruition. All of the TTL feedlines leaked heavily before any cryogenic testing, all of the SARTM feedlines leaked heavily after one cryogenic cycle. Thus, only the HLU with autoclave cure feedlines underwent the complete test matrix. They passed the cyclic testing and were pressurized to failure.

Influence of deposition conditions on electrical and mechanical properties of Sm2O3-doped CeO2 thin films prepared by EB-PVD (+IBAD) methods. Part 1: Effective relative permittivity

NASA Astrophysics Data System (ADS)

Hartmanová, Mária; Nádaždy, Vojtech; Kundracik, František; Mansilla, Catina

2013-03-01

Study is devoted to the effective relative permittivity ɛr of CeO2 + x. Sm2O3 thin films prepared by electron-beam physical vapour deposition and ionic beam-assisted deposition methods; ɛr was investigated by three independent ways from the bulk parallel capacitance Cp, impedance capacitance Cimp, and accumulation capacitance Cacc in dependence on the deposition conditions (deposition temperature, dopant amount x and Ar+ ion bombardment during the film deposition) used. Investigations were performed using impedance spectroscopy, capacitance-voltage and current-voltage characteristics as well as deep level transient spectroscopy. Results obtained are described and discussed.

Characterization and application of automated in-vacuum PIXE/EBS system for direct analysis of chloride and sulfate ions attack in cementitious materials

NASA Astrophysics Data System (ADS)

Rihawy, M. S.; Alwazzeh, M.; Abbas, K.

2018-01-01

Ion beam analysis (IBA) techniques (Particle Induced X-ray Emission, PIXE and Elastic Backscattering Spectrometry, EBS), were applied to investigate chloride and sulfate ions diffusion into laboratory prepared mortar samples. Development and characterization of an automated in-vacuum macro PIXE/EBS system is thoroughly discussed. Depth profile information of both chloride and sulfate ions in laboratory prepared mortar samples, after immersion in sea water for nine months, was rapidly and easily obtained at fairly low cost and with standardless analysis, demonstrating the value of the application of IBA to elemental depth profiling in cementitious materials. Chloride and sulfate depth profiles were obtained for two sets of mortar samples, one prepared with different water/cement (W/C) ratios and the other with different sand/cement (S/C) ratios. Results showed higher diffusion rates of both chloride and sulfate ions when both ratios are increased. Additionally, the W/C ratio has a stronger influence in both sulfate and chloride penetration than the S/C ratio, and chloride ions penetrate faster than sulfates. Advantages and limitations of applying IBA techniques in this investigation are discussed. The comparison between PIXE and other X-ray based analytical techniques, namely X-ray fluorescence (XRF) and energy and wavelength dispersive X-rays (EDX/WDX), as well as other traditional wet chemical methods is reviewed, and industrial applications are discussed.

MEASUREMENT OF SECONDARY NEUTRONS GENERATED DURING PROTON THERAPY.

PubMed

Vykydal, Z; Andrlík, M; Bártová, H; Králík, M; Šolc, J; Vondráček, V

2016-12-01

Measurements described in this article were carried out with the aim of evaluating risks of the patient exposure to secondary neutrons during treatment at the Proton Therapy Centre Prague. The neutron spectral fluence was measured by means of the extended Bonner sphere spectrometer (EBS). The article presents secondary neutron spectral fluences obtained by the EBS with passive thermoluminescent detectors, i.e. pairs of 6 LiF and 7 LiF chips. Measurements were performed in two positions: the first one behind the Nylon 6 phantom, and the second one close to the range shifter to evaluate their contribution to the generation of neutrons. Both the Nylon 6 phantom and the range shifter were irradiated with a pencil beam of protons 4 mm in diameter and the energy of 200 MeV. The results are supplemented with the values of effective dose derived from neutron spectral fluences. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Inkjet Assisted Creation of Self-Healing Layers Between Composite Plies

DTIC Science & Technology

2013-07-29

technology into a prepreg manufacturing process. The approach consisted of depositing novel thermoplastic low-viscosity microdroplets with chemically and...mechanically comparable properties to epoxy matrix in aerospace grade composites onto fiber-reinforced epoxy prepregs before curing using an ink-jet... prepreg Cycom977-2. Double cantilever beam (DCB) and short beam shear (SBS) tests were used to evaluate the self-healing efficiency. It was shown

Polymerization of room-temperature ionic liquid monomers by electron beam irradiation with the aim of fabricating three-dimensional micropolymer/nanopolymer structures.

PubMed

Minamimoto, H; Irie, H; Uematsu, T; Tsuda, T; Imanishi, A; Seki, S; Kuwabata, S

2015-04-14

A novel method for fabricating microsized and nanosized polymer structures from a room-temperature ionic liquid (RTIL) on a Si substrate was developed by the patterned irradiation of an electron beam (EB). An extremely low vapor pressure of the RTIL, 1-allyl-3-ethylimidazolium bis((trifluoromethane)sulfonyl)amide, allows it to be introduced into the high-vacuum chamber of an electron beam apparatus to conduct a radiation-induced polymerization in the nanoregion. We prepared various three-dimensional (3D) micro/nanopolymer structures having high aspect ratios of up to 5 with a resolution of sub-100 nm. In addition, the effects of the irradiation dose and beam current on the physicochemical properties of the deposited polymers were investigated by recording the FT-IR spectra and Young's modulus. Interestingly, the overall shapes of the obtained structures were different from those prepared in our recent study using a focused ion beam (FIB) even if the samples were irradiated in a similar manner. This may be due to the different transmission between the two types of beams as discussed on the basis of the theoretical calculations of the quantum beam trajectories. Perceptions obtained in this study provide facile preparation procedures for the micro/nanostructures.

Process-Structure-Property Relationships of Micron Thick Gadolinium Oxide Films Deposited by Reactive Electron Beam-Physical Vapor Deposition (EB-PVD)

DTIC Science & Technology

2014-12-01

surface roughness on film properties must be considered. Stability at the interface between the film and the substrate becomes critical with...etc.). Addition of atoms to the growing surface creates additional surface energy. Therefore, nuclei of a critical size 23 must be formed in order... critical nuclei size and a lower nucleation rate. Higher deposition rates result in a decreased critical nuclei size which leads to an increase in

The effect of Al intermediate layer on thermal resistance of EB-PVD yttria-stabilized zirconia coatings on titanium substrate

NASA Astrophysics Data System (ADS)

Panin, Alexey; Panin, Victor; Kazachenok, Marina; Shugurov, Artur; Sinyakova, Elena; Martynov, Sergey; Rusyaev, Andrey; Kasterov, Artur

2017-12-01

The yttria-stabilized zirconia coatings sprayed on titanium substrates by the electron beam physical vapor deposition were subjected to thermal annealing in air at 1000°C for 1, 30 and 60 min. The delamination and fracture of the coatings are studied by the scanning electron microscopy and X-ray diffraction. It is shown that a magnetron sputtered Al interlayer between the coating and the substrate considerably improves the thermal resistance of ceramic coatings.

47 CFR 27.5 - Frequencies.

Code of Federal Regulations, 2010 CFR

2010-10-01

...-2560 MHz EBS Channel C2: 2560-2566 MHz EBS Channel D2: 2566-2572 MHz EBS Channel C3: 2572-2578 MHz EBS... MHz EBS Channel D1: 2551.5-2557 MHz EBS Channel D2: 2557-2562.5 MHz EBS Channel D3: 2562.5-2568 MHz...

Assessment and prediction of drying shrinkage cracking in bonded mortar overlays

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

Beushausen, Hans, E-mail: hans.beushausen@uct.ac.za; Chilwesa, Masuzyo

2013-11-15

Restrained drying shrinkage cracking was investigated on composite beams consisting of substrate concrete and bonded mortar overlays, and compared to the performance of the same mortars when subjected to the ring test. Stress development and cracking in the composite specimens were analytically modeled and predicted based on the measurement of relevant time-dependent material properties such as drying shrinkage, elastic modulus, tensile relaxation and tensile strength. Overlay cracking in the composite beams could be very well predicted with the analytical model. The ring test provided a useful qualitative comparison of the cracking performance of the mortars. The duration of curing wasmore » found to only have a minor influence on crack development. This was ascribed to the fact that prolonged curing has a beneficial effect on tensile strength at the onset of stress development, but is in the same time not beneficial to the values of tensile relaxation and elastic modulus. -- Highlights: •Parameter study on material characteristics influencing overlay cracking. •Analytical model gives good quantitative indication of overlay cracking. •Ring test presents good qualitative indication of overlay cracking. •Curing duration has little effect on overlay cracking.« less

Experimental Study on Full-Scale Beams Made by Reinforced Alkali Activated Concrete Undergoing Flexure

PubMed Central

Monfardini, Linda; Minelli, Fausto

2016-01-01

Alkali Activated Concrete (AAC) is an alternative kind of concrete that uses fly ash as a total replacement of Portland cement. Fly ash combined with alkaline solution and cured at high temperature reacts to form a binder. Four point bending tests on two full scale beams made with AAC are described in this paper. Companion small material specimens were also casted with the aim of properly characterizing this new tailored material. The beam’s length was 5000 mm and the cross section was 200 mm × 300 mm. The AAC consisted of fly ash, water, sand 0–4 mm and coarse aggregate 6–10 mm; and the alkaline solution consisted of sodium hydroxide mixed with sodium silicate. No cement was utilized. The maximum aggregate size was 10 mm; fly ash was type F, containing a maximum calcium content of 2%. After a rest period of two days, the beam was cured at 60 °C for 24 h. Data collected and critically discussed included beam deflection, crack patterns, compressive and flexural strength and elastic modulus. Results show how AAC behavior is comparable with Ordinary Portland Cement (OPC) based materials. Nonlinear numerical analyses are finally reported, promoting a better understanding of the structural response. PMID:28773861

Longitudinal Coupled-Bunch Instability Around 1 GHz at the CERN PS Booster

NASA Astrophysics Data System (ADS)

Schönauer, H.; Caspers, F.; Chanel, M.; Soby, L.; D'Yachkov, M.

1997-05-01

The fast-growing "Ring 4" instability occurring at intensities above 6.5 10^12 protons in the top one of the four PSB rings is finally explained by an asymmetry in the 42 vacuum pump manifolds common to all rings. Impedance measurements (wire method) and numerical calculations show a sharp resonant peak (Q 2000) at 1100 MHz and shunt impedances two times higher for the Ring 4 ports as compared to the other rings. This factor is sufficient to explain that the threshold of the instability falls below the maximum intensity only in Ring 4. A final, but labour-intensive and expensive, cure consists of inserting short-circuiting sleeves into all 168 beam ports. A temporary antidote is attempted by fitting ceramic damping resistors penetrating the top cavity through spare gauge ports. Results of beam and impedance measurements and of the cure will be presented and discussed.

Experimental Studies on Behaviour of Reinforced Geopolymer Concrete Beams Subjected to Monotonic Static Loading

NASA Astrophysics Data System (ADS)

Madheswaran, C. K.; Ambily, P. S.; Dattatreya, J. K.; Ramesh, G.

2015-06-01

This work describes the experimental investigation on behaviour of reinforced GPC beams subjected to monotonic static loading. The overall dimensions of the GPC beams are 250 mm × 300 mm × 2200 mm. The effective span of beam is 1600 mm. The beams have been designed to be critical in shear as per IS:456 provisions. The specimens were produced from a mix incorporating fly ash and ground granulated blast furnace slag, which was designed for a compressive strength of 40 MPa at 28 days. The reinforced concrete specimens are subjected to curing at ambient temperature under wet burlap. The parameters being investigated include shear span to depth ratio (a/d = 1.5 and 2.0). Experiments are conducted on 12 GPC beams and four OPCC control beams. All the beams are tested using 2000 kN servo-controlled hydraulic actuator. This paper presents the results of experimental studies.

Exploratory Study on the Effects of Novel Diamine Curing Agents and Isocyanate Precursors on the Properties of New Epoxy and Urethane Adhesives

NASA Technical Reports Server (NTRS)

Glasgow, D. Gerald; Garthwait, Clayborn

1977-01-01

This report covers the results of investigations directed toward studying the effects of novel aromatic diamine structures on epoxy adhesive properties and includes work done under a modification to the original contract. Three aromatic diamines based on diphenylsulfone and benzophenone were studied as epoxy adhesive curing agents. Previously found differences in adhesive strengths for meta vs para orientation were not found in these series. The use of aluminum and alumina as fillers in a m,m'-methylene dianiline-cured epoxy adhesive was not found to be beneficial to adhesive strength. Alumina filled adhesives had much lower strength than unfilled adhesives. The unfilled m,m'-methylene dianiline-based epoxy adhesive had excellent resistance to moisture relative to a p,p'-methylene dianiline-based adhesive and maintained good strengths up to 250 F. A glass fiber composite based on a m,m'-methylene dianiline-cured epoxy appeared to be equivalent to the p,p'-methylene dianiline-cured epoxy as judged by short beam shear tests.

Degree of conversion and cross-link density within a resin-matrix composite.

PubMed

Al-Zain, Afnan O; Eckert, George J; Lukic, Henry; Megremis, Spiro J; Platt, Jeffrey A

2018-05-01

The aims of this study were to profile light radiated from two light-curing units (LCUs) and evaluate profile relationship to polymerization patterns within a resin-matrix composite (RMC). Beam profiles of one multiple emission peak light-emitting-diode and one quartz-tungsten-halogen curing-unit were measured using a beam profiler/spectrometer system. A camera-based profiler and an integrating sphere/spectrometer assembly were used to evaluate each LCU beam. Polymerization patterns within a nano-hybrid RMC were investigated using a mapping approach by assessing the degree of conversion utilizing micro-Raman spectroscopy and indirectly estimating cross-link-density by repeated microhardness testing before and after exposure to ethanol (%KH reduction, n = 3). The irradiance received on the top and bottom specimen surfaces from both LCUs was measured using a MARC-RC system. The investigated beam profile area from both LCUs was non-uniform and yielded localized discrepancies in DC (55.7-74.9%) and %KH reduction (26.7-54.1%). The LCU irradiance received at the bottom of the specimens was ∼10% of the top value. This study demonstrated that LCU beam profiles were non-uniform in the area explored. Localized differences in DC and %KH reduction existed throughout the RMC specimens but did not follow a specific pattern. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1496-1504, 2018. © 2017 Wiley Periodicals, Inc.

Toughened epoxy resin system and a method thereof

DOEpatents

Janke, C.J.; Dorsey, G.F.; Havens, S.J.; Lopata, V.J.

1998-03-10

Mixtures of epoxy resins with cationic initiators are curable under high energy ionizing radiation such as electron beam radiation, X-ray radiation, and gamma radiation. The composition of this process consists of an epoxy resin, a cationic initiator such as a diaryliodonium or triarylsulfonium salt of specific anions, and a toughening agent such as a thermoplastic, hydroxy-containing thermoplastic oligomer, epoxy-containing thermoplastic oligomer, reactive flexibilizer, rubber, elastomer, or mixture thereof. Cured compositions have high glass transition temperatures, good mechanical properties, and good toughness. These properties are comparable to those of similar thermally cured epoxies.

Toughened epoxy resin system and a method thereof

DOEpatents

Janke, Christopher J.; Dorsey, George F.; Havens, Stephen J.; Lopata, Vincent J.

1998-01-01

Mixtures of epoxy resins with cationic initiators are curable under high energy ionizing radiation such as electron beam radiation, X-ray radiation, and gamma radiation. The composition of this process consists of an epoxy resin, a cationic initiator such as a diaryliodonium or triarylsulfonium salt of specific anions, and a toughening agent such as a thermoplastic, hydroxy-containing thermoplastic oligomer, epoxy-containing thermoplastic oligomer, reactive flexibilizer, rubber, elastomer, or mixture thereof. Cured compositions have high glass transition temperatures, good mechanical properties, and good toughness. These properties are comparable to those of similar thermally cured epoxies.

The microtubule end-binding protein EB2 is a central regulator of microtubule reorganisation in apico-basal epithelial differentiation.

PubMed

Goldspink, Deborah A; Gadsby, Jonathan R; Bellett, Gemma; Keynton, Jennifer; Tyrrell, Benjamin J; Lund, Elizabeth K; Powell, Penny P; Thomas, Paul; Mogensen, Mette M

2013-09-01

Microtubule end-binding (EB) proteins influence microtubule dynamic instability, a process that is essential for microtubule reorganisation during apico-basal epithelial differentiation. Here, we establish for the first time that expression of EB2, but not that of EB1, is crucial for initial microtubule reorganisation during apico-basal epithelial differentiation, and that EB2 downregulation promotes bundle formation. EB2 siRNA knockdown during early stages of apico-basal differentiation prevented microtubule reorganisation, whereas its downregulation at later stages promoted microtubule stability and bundle formation. Interestingly, although EB1 is not essential for microtubule reorganisation, its knockdown prevented apico-basal bundle formation and epithelial elongation. siRNA depletion of EB2 in undifferentiated epithelial cells induced the formation of straight, less dynamic microtubules with EB1 and ACF7 lattice association and co-alignment with actin filaments, a phenotype that could be rescued by inhibition with formin. Importantly, in situ inner ear and intestinal crypt epithelial tissue revealed direct correlations between a low level of EB2 expression and the presence of apico-basal microtubule bundles, which were absent where EB2 was elevated. EB2 is evidently important for initial microtubule reorganisation during epithelial polarisation, whereas its downregulation facilitates EB1 and ACF7 microtubule lattice association, microtubule-actin filament co-alignment and bundle formation. The spatiotemporal expression of EB2 thus dramatically influences microtubule organisation, EB1 and ACF7 deployment and epithelial differentiation.

Effect of electron beam radiation processing on mechanical and thermal properties of fully biodegradable crops straw/poly (vinyl alcohol) biocomposites

NASA Astrophysics Data System (ADS)

Guo, Dan

2017-01-01

Fully biodegradable biocomposites based on crops straw and poly(vinyl alcohol) was prepared through thermal processing, and the effect of electron beam radiation processing with N,N-methylene double acrylamide as radiation sensitizer on mechanical and thermal properties of the biocomposites were investigated. The results showed that, when the radiation dose were in the range of 0-50 kGy, the mechanical and thermal properties of the biocomposites could be improved significantly through the electron beam radiation processing, and the interface compatibility was also improved because of the formation of stable cross-linked network structure, when the radiation dose were above the optimal value (50 kGy), the comprehensive properties of the biocomposites were gradually destroyed. EB radiation processing could be used as an effective technology to improve the comprehensive performance of the biocomposites, and as a green and efficient processing technology, radiation processing takes place at room temperature, and no contamination and by-product are possible.

Structural and optical properties of electron-beam-evaporated ZnSe 1- x Te x Ternary compounds with various Te contents

NASA Astrophysics Data System (ADS)

Suthagar, J.; Suthan Kissinger, N. J.; Sharli Nath, G. M.; Perumal, K.

2014-01-01

ZnSe1- x Te x films with different tellurium (Te) contents were deposited by using an electron beam (EB) evaporation technique onto glass substrates for applications to optoelectronic devices. The structural and the optical properties of the ZnSe1- x Te x films were studied in the present work. The host material ZnSe1- x Te x , were prepared by using the physical vapor deposition method of the electron beam evaporation technique (PVD: EBE) under a pressure of 1 × 10-5 mbar. The X-ray diffractogram indicated that these alloy films had cubic structure with a strong preferential orientation of the crystallites along the (1 1 1) direction. The optical properties showed that the band gap (E g ) values varied from 2.73 to 2.41 eV as the tellurium content varied from 0.2 to 0.8. Thus the material properties can be altered and excellently controlled by controlling the system composition x.

Oxidative decomposition of aromatic hydrocarbons by electron beam irradiation

NASA Astrophysics Data System (ADS)

Han, Do-Hung; Stuchinskaya, Tatiana; Won, Yang-Soo; Park, Wan-Sik; Lim, Jae-Kyong

2003-05-01

Decomposition of aromatic volatile organic compounds (VOCs) under electron beam irradiation was studied in order to examine the kinetics of the process, to characterize the reaction product distribution and to develop a process of waste gas control technology. Toluene, ethylbenzene, o-, m-, p-xylenes and chlorobenzene were used as target materials. The experiments were carried out at doses ranging from 0.5 to 10 kGy, using a flow reactor utilized under electron beam irradiation. Maximum degrees of decomposition carried out at 10 kGy in air environment were 55-65% for “non-chlorinated” aromatic VOC and 85% for chlorobenzene. It was found that a combination of aromatic pollutants with chlorobenzene would considerably increase the degradation value up to nearly 50% compared to the same compounds in the absence of chlorine groups. Based on our experimental observation, the degradation mechanism of the aromatic compounds combined with chloro-compound suggests that a chlorine radical, formed from EB irradiation, induces a chain reaction, resulting in an accelerating oxidative destruction of aromatic VOCs.

An experience of electron beam (EB) irradiated gemstones in Malaysian nuclear agency

NASA Astrophysics Data System (ADS)

Idris, Sarada; Hairaldin, Siti Zulaiha; Tajau, Rida; Karim, Jamilah; Jusoh, Suhaimi; Ghazali, Zulkafli; Ahmad, Shamshad

2014-02-01

In Nuclear Malaysia, a study on gemstone irradiation using beta particle is conducted. The purpose of the study is to evaluate the gemstone colour enhancement by using different kind of precious and non-precious gemstones. By using irradiation technique, selected gemstones are exposed to highly ionizing radiation electron beam to knock off electrons to generate colour centres culminating in the introduction of deeper colours. The colour centres may be stable or unstable depending on the nature of colour centre produced. The colour change of irradiated stones were measured by HunterLab colour measurement. At 50 kGy, Topaz shows changes colour from colourless to golden. Meanwhile pearl shows changes from pale colour to grey. Kunzite and amethyst shows colour changes from colorless to green and pale colour to purple. Gamma survey meter measurement confirmed that irradiation treatment with 3 MeV electron beam machine does not render any activation that activate the gems to become radioactive.

An experience of electron beam (EB) irradiated gemstones in Malaysian nuclear agency

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

Idris, Sarada, E-mail: sarada@nuclearmalaysia.gov.my; Hairaldin, Siti Zulaiha, E-mail: sarada@nuclearmalaysia.gov.my; Tajau, Rida, E-mail: sarada@nuclearmalaysia.gov.my

In Nuclear Malaysia, a study on gemstone irradiation using beta particle is conducted. The purpose of the study is to evaluate the gemstone colour enhancement by using different kind of precious and non-precious gemstones. By using irradiation technique, selected gemstones are exposed to highly ionizing radiation electron beam to knock off electrons to generate colour centres culminating in the introduction of deeper colours. The colour centres may be stable or unstable depending on the nature of colour centre produced. The colour change of irradiated stones were measured by HunterLab colour measurement. At 50 kGy, Topaz shows changes colour from colourlessmore » to golden. Meanwhile pearl shows changes from pale colour to grey. Kunzite and amethyst shows colour changes from colorless to green and pale colour to purple. Gamma survey meter measurement confirmed that irradiation treatment with 3 MeV electron beam machine does not render any activation that activate the gems to become radioactive.« less

CLASPs are required for proper microtubule localization of End-binding proteins

PubMed Central

Grimaldi, Ashley D.; Maki, Takahisa; Fitton, Benjamin P.; Roth, Daniel; Yampolsky, Dmitry; Davidson, Michael W.; Svitkina, Tatyana; Straube, Anne; Hayashi, Ikuko; Kaverina, Irina

2014-01-01

Summary Microtubule (MT) plus-end tracking proteins (+TIPs) preferentially localize to MT plus-ends. End-binding proteins (EBs) are master regulators of the +TIP complex; however, it is unknown whether EBs are regulated by other +TIPs. Here, we show that Cytoplasmic linker associated proteins (CLASPs) modulate EB localization at MTs. In CLASP-depleted cells, EBs localized along the MT lattice in addition to plus-ends. The MT-binding region of CLASP was sufficient for restoring normal EB localization, while neither EB-CLASP interactions nor EB tail-binding proteins are involved. In vitro assays revealed that CLASP directly functions to remove EB from MTs. Importantly, this effect occurs specifically during MT polymerization, but not at pre-formed MTs. Increased GTP-tubulin content within MTs in CLASP-depleted cells suggests that CLASPs facilitate GTP-hydrolysis to reduce EB lattice binding. Together, these findings suggest that CLASPs influence the MT lattice itself to regulate EB and determine exclusive plus-end localization of EBs in cells. PMID:25117684

Effects of electron beam irradiation on polyamide 12 with fiberglass reinforcement

NASA Astrophysics Data System (ADS)

Jeun, Joon-Pyo; Shin, Bum-Sik; Kim, Hyun-Bin; Nho, Young-Chang; Kang, Phil-Hyun

2010-06-01

In the present study, the effects of electron beam irradiation of polyamide 12 (PA12) with fiberglass reinforcement on the thermal and wear properties were investigated. Electron beam irradiation of PA 12 was carried out over a range of irradiation doses (100-600 kGy) in air. The gel formation in the presence of a curing agent was dependent on the radiation doses. The thermal properties of irradiated PA 12 were studied in the temperature region 50-250° C to observe the changes in the melting point with radiation dose. The dimensional stability was significantly increased by electron beam irradiation and the related crosslinking of the PA 12.

Effects of electron beam irradiation on polyamide 12 with fiberglass reinforcement

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

Jeun, Joon-Pyo; Shin, Bum-Sik; Kim, Hyun-Bin

2010-06-02

In the present study, the effects of electron beam irradiation of polyamide 12 (PA12) with fiberglass reinforcement on the thermal and wear properties were investigated. Electron beam irradiation of PA 12 was carried out over a range of irradiation doses (100-600 kGy) in air. The gel formation in the presence of a curing agent was dependent on the radiation doses. The thermal properties of irradiated PA 12 were studied in the temperature region 50-250 deg. C to observe the changes in the melting point with radiation dose. The dimensional stability was significantly increased by electron beam irradiation and the relatedmore » crosslinking of the PA 12.« less

SU-E-T-296: Dosimetric Analysis of Small Animal Image-Guided Irradiator Using High Resolution Optical CT Imaging of 3D Dosimeters

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

Na, Y; Qian, X; Wuu, C

Purpose: To verify the dosimetric characteristics of a small animal image-guided irradiator using a high-resolution of optical CT imaging of 3D dosimeters. Methods: PRESAEGE 3D dosimeters were used to determine dosimetric characteristics of a small animal image-guided irradiator and compared with EBT2 films. Cylindrical PRESAGE dosimeters with 7cm height and 6cm diameter were placed along the central axis of the beam. The films were positioned between 6×6cm{sup 2} cubed plastic water phantoms perpendicular to the beam direction with multiple depths. PRESAGE dosimeters and EBT2 films were then irradiated with the irradiator beams at 220kVp and 13mA. Each of irradiated PRESAGEmore » dosimeters named PA1, PA2, PB1, and PB2, was independently scanned using a high-resolution single laser beam optical CT scanner. The transverse images were reconstructed with a 0.1mm high-resolution pixel. A commercial Epson Expression 10000XL flatbed scanner was used for readout of irradiated EBT2 films at a 0.4mm pixel resolution. PDD curves and beam profiles were measured for the irradiated PRESAGE dosimeters and EBT2 films. Results: The PDD agreements between the irradiated PRESAGE dosimeter PA1, PA2, PB1, PB2 and the EB2 films were 1.7, 2.3, 1.9, and 1.9% for the multiple depths at 1, 5, 10, 15, 20, 30, 40 and 50mm, respectively. The FWHM measurements for each PRESAEGE dosimeter and film agreed with 0.5, 1.1, 0.4, and 1.7%, respectively, at 30mm depth. Both PDD and FWHM measurements for the PRESAGE dosimeters and the films agreed overall within 2%. The 20%–80% penumbral widths of each PRESAGE dosimeter and the film at a given depth were respectively found to be 0.97, 0.91, 0.79, 0.88, and 0.37mm. Conclusion: Dosimetric characteristics of a small animal image-guided irradiator have been demonstrated with the measurements of PRESAGE dosimeter and EB2 film. With the high resolution and accuracy obtained from this 3D dosimetry system, precise targeting small animal irradiation can be achieved.« less

Electron Beam Propagation Through a Magnetic Wiggler with Random Field Errors

DTIC Science & Technology

1989-08-21

Another quantity of interest is the vector potential 6.A,.(:) associated with the field error 6B,,,(:). Defining the normalized vector potentials ba = ebA...then follows that the correlation of the normalized vector potential errors is given by 1 . 12 (-a.(zj)a.,(z2)) = a,k,, dz’ , dz" (bBE(z’)bB , (z")) a2...Throughout the following, terms of order O(z:/z) will be neglected. Similarly, for the y-component of the normalized vector potential errors, one

Self-Calibration of BICEP1 Three-Year Data and Constraints on Astrophysical Polarization Rotation

NASA Technical Reports Server (NTRS)

Kaufman, J. P.; Miller, N. J.; Shimon, M.; Barkats, D.; Bischoff, C.; Buder, I.; Keating, B. G.; Kovac, J. M.; Ade, P. A. R.; Aikin, R.;

The Effect of Curing Temperature on the Fracture Toughness of Fiberglass Epoxy Composites

NASA Astrophysics Data System (ADS)

Ryan, Thomas J.

The curing reaction in a thermoset polymer matrix composite is often accelerated by the addition of heat in an oven or autoclave. The heat added increases the rate of the polymerization reaction and cross-linking in the material. The cure cycle used (temperature, pressure and time) can therefore alter the final material properties. This research focuses on how the curing temperature (250, 275, 300 °F) affects the yield strength and the mode I interlaminar fracture toughness, GI, of a unidirectional S-2 glass epoxy composite. The test method that was used for the tension test was ASTM D3039 and the test method for the mode I interlaminar fracture toughness, the double cantilever beam (DCB) test, was ASTM D5528. The DCB specimens were fabricated with a non-adhesive insert at the midplane of the composite that serves as the initiatior of the delamination. Opening forces were then applied to the specimen, causing the crack propagation. The results show that increasing the cure temperature by 50 °F increased the tensile strength by 10% (86.54 - 94.73 ksi) and decreased the fracture toughness 20% (506.23 - 381.31 J/m 2). Thus, the curing temperature can cause a trade-off between these two properties, which means that the curing cycle will need to be altered based on the intended use and the required material properties.

VEGF and IHH rescue definitive hematopoiesis in Gata-4 and Gata-6-deficient murine embryoid bodies.

PubMed

Pierre, Monique; Yoshimoto, Momoko; Huang, Lan; Richardson, Matthew; Yoder, Mervin C

2009-09-01

Murine embryonic stem cells can be differentiated into embryoid bodies (EBs), which serve as an in vitro model recapitulating many aspects of embryonic yolk sac hematopoiesis. Differentiation of embryonic stem cells deficient in either Gata-4 or Gata-6 results in EBs with disrupted visceral endoderm (VE). While lack of VE has detrimental effects on hematopoiesis in vivo, it is unclear whether lack of VE affects hematopoiesis in EBs. Therefore, we compared Gata-4 null (G4N) and Gata-6 null (G6N) EBs with wild-type EBs to assess their ability to commit to hematopoietic cells. EB VE formation was examined using cell-sorting techniques and analysis visceral endoderm gene expression. Hematopoietic progenitor potential of EBs cultured under various conditions was assessed using colony-forming assays. Definitive erythroid, granulocyte-macrophage, and mixed colonies were significantly reduced in G4N and G6N EBs compared to wild-type EBs. Vascular endothelial growth factor (VEGF) expression and secretion were also reduced in both G4N and G6N EBs, consistent with VE serving as a site of VEGF production. Addition of exogenous VEGF(165), to EB cultures completely rescued definitive colony-forming cells in G4N and G6N EBs. This rescue response could be blocked by addition of soluble Flk-1 Fc to EB cultures. Similarly, addition of exogenous Indian hedgehog to EB cultures also recovers the diminishment in definitive hematopoiesis in a reversible manner. These results suggest that the absence of VE in G4N and G6N EBs does not prevent emergence of definitive progenitors from EBs. However, the decreased level of VEGF and Indian hedgehog production in VE devoid G4N and G6N EBs attenuates definitive hematopoietic progenitor cell expansion.

Process margin enhancement for 0.25-μm metal etch process

NASA Astrophysics Data System (ADS)

Lee, Chung Y.; Ma, Wei Wen; Lim, Eng H.; Cheng, Alex T.; Joy, Raymond; Ross, Matthew F.; Wong, Selmer S.; Marlowe, Trey

2000-06-01

This study evaluates electron beam stabilization of UV6, a positive tone Deep-UV (DUV) resist from Shipley, for a 0.25 micrometer metal etch application. Results are compared between untreated resist and resist treated with different levels of electron beam stabilization. The electron beam processing was carried out in an ElectronCureTM flood electron beam exposure system from Honeywell International Inc., Electron Vision. The ElectronCureTM system utilizes a flood electron beam source which is larger in diameter than the substrate being processed, and is capable of variable energy so that the electron range is matched to the resist film thickness. Changes in the UV6 resist material as a result of the electron beam stabilization are monitored via spectroscopic ellipsometry for film thickness and index of refraction changes and FTIR for analysis of chemical changes. Thermal flow stability is evaluated by applying hot plate bakes of 150 degrees Celsius and 200 degrees Celsius, to patterned resist wafers with no treatment and with an electron beam dose level of 2000 (mu) C/cm2. A significant improvement in the thermal flow stability of the patterned UV6 resist features is achieved with the electron beam stabilization process. Etch process performance of the UV6 resist was evaluated by performing a metal pattern transfer process on wafers with untreated resist and comparing these with etch results on wafers with different levels of electron beam stabilization. The etch processing was carried out in an Applied Materials reactor with an etch chemistry including BCl3 and Cl2. All wafers were etched under the same conditions and the resist was treated after etch to prevent further erosion after etch but before SEM analysis. Post metal etch SEM cross-sections show the enhancement in etch resistance provided by the electron beam stabilization process. Enhanced process margin is achieved as a result of the improved etch resistance, and is observed in reduced resist side-wall angles after etch. Only a slight improvement is observed in the isolated to dense bias effects of the etch process. Improved CD control is also achieved by applying the electron beam process, as more consistent CDs are observed after etch.

Manufacturing of three-dimensionally microstructured nanocomposites through microfluidic infiltration.

PubMed

Dermanaki-Farahani, Rouhollah; Lebel, Louis Laberge; Therriault, Daniel

2014-03-12

Microstructured composite beams reinforced with complex three-dimensionally (3D) patterned nanocomposite microfilaments are fabricated via nanocomposite infiltration of 3D interconnected microfluidic networks. The manufacturing of the reinforced beams begins with the fabrication of microfluidic networks, which involves layer-by-layer deposition of fugitive ink filaments using a dispensing robot, filling the empty space between filaments using a low viscosity resin, curing the resin and finally removing the ink. Self-supported 3D structures with other geometries and many layers (e.g. a few hundreds layers) could be built using this method. The resulting tubular microfluidic networks are then infiltrated with thermosetting nanocomposite suspensions containing nanofillers (e.g. single-walled carbon nanotubes), and subsequently cured. The infiltration is done by applying a pressure gradient between two ends of the empty network (either by applying a vacuum or vacuum-assisted microinjection). Prior to the infiltration, the nanocomposite suspensions are prepared by dispersing nanofillers into polymer matrices using ultrasonication and three-roll mixing methods. The nanocomposites (i.e. materials infiltrated) are then solidified under UV exposure/heat cure, resulting in a 3D-reinforced composite structure. The technique presented here enables the design of functional nanocomposite macroscopic products for microengineering applications such as actuators and sensors.

Manufacturing of Three-dimensionally Microstructured Nanocomposites through Microfluidic Infiltration

PubMed Central

Dermanaki-Farahani, Rouhollah; Lebel, Louis Laberge; Therriault, Daniel

2014-01-01

Microstructured composite beams reinforced with complex three-dimensionally (3D) patterned nanocomposite microfilaments are fabricated via nanocomposite infiltration of 3D interconnected microfluidic networks. The manufacturing of the reinforced beams begins with the fabrication of microfluidic networks, which involves layer-by-layer deposition of fugitive ink filaments using a dispensing robot, filling the empty space between filaments using a low viscosity resin, curing the resin and finally removing the ink. Self-supported 3D structures with other geometries and many layers (e.g. a few hundreds layers) could be built using this method. The resulting tubular microfluidic networks are then infiltrated with thermosetting nanocomposite suspensions containing nanofillers (e.g. single-walled carbon nanotubes), and subsequently cured. The infiltration is done by applying a pressure gradient between two ends of the empty network (either by applying a vacuum or vacuum-assisted microinjection). Prior to the infiltration, the nanocomposite suspensions are prepared by dispersing nanofillers into polymer matrices using ultrasonication and three-roll mixing methods. The nanocomposites (i.e. materials infiltrated) are then solidified under UV exposure/heat cure, resulting in a 3D-reinforced composite structure. The technique presented here enables the design of functional nanocomposite macroscopic products for microengineering applications such as actuators and sensors. PMID:24686754

Electron beam irradiation impact on surface structure and wettability of ethylene-vinyl alcohol copolymer

NASA Astrophysics Data System (ADS)

El-Saftawy, A. A.; Ragheb, M. S.; Zakhary, S. G.

2018-06-01

In the present study, electron beam (EB) is utilized to tailor the surface structure and wetting behavior of ethylene-vinyl alcohol (EVOH) copolymer. The structural deformation is examined by x-ray diffractometer (XRD). The recorded patterns reveal the formation of disordered systems on the irradiated surface. Also, the surface crystallinity degree, crystallite size, and micro-strain are studied. The microstructure induced modifications of the irradiated samples are investigated by 1-dimensional proton nuclear magnetic resonance 1H NMR spectroscopic analysis. The recorded spectra showed that the hydroxyl group (O-H) absorption intensity, enhanced compared to that of methylene (-CH2) and methine (>C-H) groups. Likewise, the changes of the polymer surface chemistry are studied by Fourier transform infrared spectroscopy (FTIR) and showed that the surface polarity improved after irradiation. The contact angle method is used to prove the surface wettability improvements after irradiation. Additionally, the fucoidan-coated samples exhibit great enhancements in surface wettability and have a reduced recovery effect compared to the uncoated samples. The surface free energy and bonding adhesion are studied as well. The fucoidan-coated samples are found to have a larger adhesion strength than that of the EVOH samples (pristine and irradiated). Finally, surface morphology and roughness are traced by atomic force microscopy (AFM). The improvements in surface wettability and adhesion are attributed to the modified surface roughness and the increased surface polarity. To sum up, combining EB irradiation and fucoidan enhance the surface wettability of EVOH in a controlled way keeping the bulk properties unaffected.

1985 Particle Accelerator Conference: Accelerator Engineering and Technology, 11th, Vancouver, Canada, May 13-16, 1985, Proceedings

NASA Astrophysics Data System (ADS)

Strathdee, A.

1985-10-01

The topics discussed are related to high-energy accelerators and colliders, particle sources and electrostatic accelerators, controls, instrumentation and feedback, beam dynamics, low- and intermediate-energy circular accelerators and rings, RF and other acceleration systems, beam injection, extraction and transport, operations and safety, linear accelerators, applications of accelerators, radiation sources, superconducting supercolliders, new acceleration techniques, superconducting components, cryogenics, and vacuum. Accelerator and storage ring control systems are considered along with linear and nonlinear orbit theory, transverse and longitudinal instabilities and cures, beam cooling, injection and extraction orbit theory, high current dynamics, general beam dynamics, and medical and radioisotope applications. Attention is given to superconducting RF structures, magnet technology, superconducting magnets, and physics opportunities with relativistic heavy ion accelerators.

Significance of two distinct types of tryptophan synthase beta chain in Bacteria, Archaea and higher plants.

PubMed

Xie, Gary; Forst, Christian; Bonner, Carol; Jensen, Roy A

2002-01-01

Tryptophan synthase consists of two subunits, alpha and beta. Two distinct subgroups of beta chain exist. The major group (TrpEb_1) includes the well-studied beta chain of Salmonella typhimurium. The minor group of beta chain (TrpEb_2) is most frequently found in the Archaea. Most of the amino-acid residues important for catalysis are highly conserved between both TrpE subfamilies. Conserved amino-acid residues of TrpEb_1 that make allosteric contact with the TrpEa subunit (the alpha chain) are absent in TrpEb_2. Representatives of Archaea, Bacteria and higher plants all exist that possess both TrpEb_1 and TrpEb_2. In those prokaryotes where two trpEb genes coexist, one is usually trpEb_1 and is adjacent to trpEa, whereas the second is trpEb_2 and is usually unlinked with other tryptophan-pathway genes. TrpEb_1 is nearly always partnered with TrpEa in the tryptophan synthase reaction. However, by default at least six lineages of the Archaea are likely to use TrpEb_2 as the functional beta chain, as TrpEb_1 is absent. The six lineages show a distinctive divergence within the overall TrpEa phylogenetic tree, consistent with the lack of selection for amino-acid residues in TrpEa that are otherwise conserved for interfacing with TrpEb_1. We suggest that the standalone function of TrpEb_2 might be to catalyze the serine deaminase reaction, an established catalytic capability of tryptophan synthase beta chains. A coincident finding of interest is that the Archaea seem to use the citramalate pathway, rather than threonine deaminase (IlvA), to initiate the pathway of isoleucine biosynthesis.

New electron beam facility for R&D and production at acsion industries

NASA Astrophysics Data System (ADS)

Lopata, V. J.; Barnard, J. W.; Saunders, C. B.; Stepanik, T. M.

2003-08-01

Since its incorporation in 1998, Acsion Industries Inc. has been working with clients to develop industrial uses of electron processing for improving products and manufacturing processes. Acsion has promoted this technology for sterilizing medical devices and pharmaceuticals, for treating wood pulp in the viscose/rayon process, for reducing pathogens in food and animal feed, and for curing advanced composites for the aerospace industry. As a result of significant developments in its composite curing programs, Acsion has recently made major modifications to its facility to increase its production and R&D capabilities. These modifications are described in this paper.

Evaluation of the Health Protection Event-Based Surveillance for the London 2012 Olympic and Paralympic Games.

PubMed

Severi, E; Kitching, A; Crook, P

2014-06-19

The Health Protection Agency (HPA) (currently Public Health England) implemented the Health Protection Event-Based Surveillance (EBS) to provide additional national epidemic intelligence for the 2012 London Olympic and Paralympic Games (the Games). We describe EBS and evaluate the system attributes. EBS aimed at identifying, assessing and reporting to the HPA Olympic Coordination Centre (OCC) possible national infectious disease threats that may significantly impact the Games. EBS reported events in England from 2 July to 12 September 2012. EBS sourced events from reports from local health protection units and from screening an electronic application 'HPZone Dashboard' (DB). During this period, 147 new events were reported to EBS, mostly food-borne and vaccine-preventable diseases: 79 from regional units, 144 from DB (76 from both). EBS reported 61 events to the OCC: 21 of these were reported onwards. EBS sensitivity was 95.2%; positive predictive value was 32.8%; reports were timely (median one day; 10th percentile: 0 days - same day; 90th percentile: 3.6 days); completeness was 99.7%; stability was 100%; EBS simplicity was assessed as good; the daily time per regional or national unit dedicated to EBS was approximately 4 hours (weekdays) and 3 hours (weekends). OCC directors judged EBS as efficient, fast and responsive. EBS provided reliable, reassuring, timely, simple and stable national epidemic intelligence for the Games.

Cardiomyopathy in Patients With Hereditary Bullous Epidermolysis.

PubMed

Batalla, A; Vicente, A; Bartrons, J; Prada, F; Fortuny, C; González-Enseñat, M A

In recent decades, an association has been reported between epidermolysis bullosa (EB) and dilated cardiomyopathy (DC). DC is typically in an advanced phase when detected, leading to a poorer prognosis. Our objective was to determine the prevalence of DC in patients with EB seen in Hospital San Joan de Déu in Barcelona, Spain, between May 1986 and April 2015. This was a descriptive, cross-sectional chart-review study in which we recorded the type and main subtypes of EB and the presence or absence of DC. Fifty-seven patients with EB were found, 19 with EB simplex, 10 with junctional EB, 27 with dystrophic EB (14 dominant dystrophic and 13 recessive dystrophic), and just 1 with Kindler syndrome. DC was detected in only 2 patients with recessive dystrophic EB. Twenty-three patients had presented factors that could have had a causal relationship with the potential onset of DC. DC is a possible complication of EB, particularly in recessive dystrophic EB. Periodic follow-up should be performed to make an early diagnosis and start treatment. Copyright © 2017 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

Effect of light dispersion of LED curing lights on resin composite polymerization.

PubMed

Vandewalle, Kraig S; Roberts, Howard W; Andrus, Jeffrey L; Dunn, William J

2005-01-01

This study evaluated the effect of light dispersion of halogen and LED curing lights on resin composite polymerization. One halogen (Optilux 501, SDS/Kerr, Orange, CA, USA) and five light-emitting diode (LED) curing lights (SmartLite iQ, Dentsply Caulk, Milford, DE, USA; LEDemetron 1, SDS/Kerr; FLASHlite 1001, Discus Dental, Culver City, CA, USA; UltraLume LED 5, Ultradent Products, South Jordan, UT, USA; Allegro, Den-Mat, Santa Maria, CA, USA) were used in this study. Specimens (8 mm diameter by 2 mm thick) were made in polytetrafluoroethylene molds using hybrid (Z100, 3M ESPE, St. Paul, MN, USA) and microfill (A110, 3M ESPE) composite resins. The top surface was polymerized for 5 seconds with the curing light guide tip positioned at a distance of 1 and 5 mm. Degree of conversion (DC) of the composite specimens was analyzed on the bottom surface using micro-Fourier Transform Infrared (FTIR) spectroscopy (Perkin-Elmer FTIR Spectrometer, Wellesley, PA, USA) 10 minutes after light activation. DC at the bottom of the 2 mm specimen was expressed as a percentage of the mean maximum DC. Five specimens were created per curing light and composite type (n=5). Percent mean DC ratios and SDs were calculated for each light under each testing condition. Data were analyzed by analysis of variance (ANOVA)/Tukey's test (alpha = .05). A beam analyzer (LBA-700, Spiricon, Logan, UT, USA) was used to record the emitted light from the curing lights at 0 and 5 mm distances (n=5). A Top Hat factor was used to compare the quality of the emitted beam profile (LBA/PC, Spiricon). The divergence angle from vertical was also determined in the x- and y-axes (LBA/PC). Mean values and SDs were calculated for each light under each testing condition (0 and 5 mm, x- and y-axes) and analyzed by a two-way ANOVA/Tukey's test (alpha = .05). For DC ratios, significant differences were found based on curing light and curing distance (p < .05). At 1 mm, Optilux 501 and FLASHlite 1001 produced significantly higher DC ratios with the hybrid resin composite. No differences were found among lights with the microfill at 1 mm. At 5 mm, SmartLite iQ, FLASHlite 1001, LEDemetron 1, and UltraLume LED 5 produced significantly higher DC ratios with the hybrid resin composite, whereas LEDemetron 1 and SmartLite iQ produced significantly higher DC ratios with the microfill resin composite. The UltraLume LED 5, Allegro, and Optilux 501 had significant reductions in mean DC ratios at curing distances of 1 and 5 mm with both resin composite types. For dispersion of light, significant differences were found in Top Hat factor and divergence angle (p < .001). SmartLite iQ had overall the highest Top Hat factor and lowest divergence angle of tested lights. A linear regression analysis relating pooled DC with pooled Top Hat factors and divergence angles found a very good correlation (r2 = .86) between dispersion of light over distance and the ability to polymerize resin composite. The latest generation of LED curing lights provides DC ratios similar to or better than the halogen curing light at a curing distance of 5 mm. Dispersion of light plays a significant role in the DC of resin composite. To maximize curing effectiveness, light guides should be maintained in close proximity to the surface of the light-activated restorative material.

The microwell control of embryoid body size in order to regulate cardiac differentiation of human embryonic stem cells.

PubMed

Mohr, Jeffrey C; Zhang, Jianhua; Azarin, Samira M; Soerens, Andrew G; de Pablo, Juan J; Thomson, James A; Lyons, Gary E; Palecek, Sean P; Kamp, Timothy J

2010-03-01

The differentiation of human embryonic stem cells (hESCs) into cardiomyocytes (CMs) using embryoid bodies (EBs) is relatively inefficient and highly variable. Formation of EBs using standard enzymatic disaggregation techniques results in a wide range of sizes and geometries of EBs. Use of a 3-D cuboidal microwell system to culture hESCs in colonies of defined dimensions, 100-500 microm in lateral dimensions and 120 microm in depth, enabled formation of more uniform-sized EBs. The 300 microm microwells produced highest percentage of contracting EBs, but flow cytometry for myosin light chain 2A (MLC2a) expressing cells revealed a similar percentage (approximately 3%) of cardiomyocytes formed in EBs from 100 microm to 300 microm microwells. These data, and immunolabeling with anti-MF20 and MLC2a, suggest that the smaller EBs are less likely to form contracting EBs, but those contracting EBs are relatively enriched in cardiomyocytes compared to larger EB sizes where CMs make up a proportionately smaller fraction of the total cells. We conclude that microwell-engineered EB size regulates cardiogenesis and can be used for more efficient and reproducible formation of hESC-CMs needed for research and therapeutic applications. (c) 2009 Elsevier Ltd. All rights reserved.

Graphene induces spontaneous cardiac differentiation in embryoid bodies

NASA Astrophysics Data System (ADS)

Ahadian, Samad; Zhou, Yuanshu; Yamada, Shukuyo; Estili, Mehdi; Liang, Xiaobin; Nakajima, Ken; Shiku, Hitoshi; Matsue, Tomokazu

2016-03-01

Graphene was embedded into the structure of mouse embryoid bodies (EBs) using the hanging drop technique. The inclusion of 0.2 mg per mL graphene in the EBs did not affect the viability of the stem cells. However, the graphene decreased the stem cell proliferation, probably by accelerating cell differentiation. The graphene also enhanced the mechanical properties and electrical conductivity of the EBs. Interestingly, the cardiac differentiation of the EB-graphene was significantly greater than that of the EBs at day 5 of culture, as confirmed by high-throughput gene analysis. Electrical stimulation (voltage, 4 V; frequency, 1 Hz; and duration, 10 ms for 2 continuous days) further enhanced the cardiac differentiation of the EBs, as demonstrated by analyses of the cardiac protein and gene expression and the beating activity of the EBs. Taken together, the results demonstrated that graphene played a major role in directing the cardiac differentiation of EBs, which has potential cell therapy and tissue regeneration applications.Graphene was embedded into the structure of mouse embryoid bodies (EBs) using the hanging drop technique. The inclusion of 0.2 mg per mL graphene in the EBs did not affect the viability of the stem cells. However, the graphene decreased the stem cell proliferation, probably by accelerating cell differentiation. The graphene also enhanced the mechanical properties and electrical conductivity of the EBs. Interestingly, the cardiac differentiation of the EB-graphene was significantly greater than that of the EBs at day 5 of culture, as confirmed by high-throughput gene analysis. Electrical stimulation (voltage, 4 V; frequency, 1 Hz; and duration, 10 ms for 2 continuous days) further enhanced the cardiac differentiation of the EBs, as demonstrated by analyses of the cardiac protein and gene expression and the beating activity of the EBs. Taken together, the results demonstrated that graphene played a major role in directing the cardiac differentiation of EBs, which has potential cell therapy and tissue regeneration applications. Electronic supplementary information (ESI) available: Fig. S1-S3, Tables S1-S4, and Movies S1-S4. See DOI: 10.1039/c5nr07059g

TIP maker and TIP marker; EB1 as a master controller of microtubule plus ends.

PubMed

Vaughan, Kevin T

2005-10-24

The EB1 protein is a member of the exciting and enigmatic family of microtubule (MT) tip-tracking proteins. EB1 acts as an exquisite marker of dynamic MT plus ends in some cases, whereas in others EB1 is thought to directly dictate the behavior of the plus ends. How EB1 differentiates between these two roles remains unclear; however, a growing list of interactions between EB1 and other MT binding proteins suggests there may be a single mechanism. Adding another layer of complexity to these interactions, two studies published in this issue implicate EB1 in cross-talk between mitotic MTs and between MTs and actin filaments (Goshima et al., p. 229; Wu et al., p. 201). These results raise the possibility that EB1 is a central player in MT-based transport, and that the activity of MT-binding proteins depends on their ability or inability to interact with EB1.

RNA Sequencing Reveals the Alteration of the Expression of Novel Genes in Ethanol-Treated Embryoid Bodies.

PubMed

Mandal, Chanchal; Kim, Sun Hwa; Chai, Jin Choul; Oh, Seon Mi; Lee, Young Seek; Jung, Kyoung Hwa; Chai, Young Gyu

2016-01-01

Fetal alcohol spectrum disorder is a collective term representing fetal abnormalities associated with maternal alcohol consumption. Prenatal alcohol exposure and related anomalies are well characterized, but the molecular mechanism behind this phenomenon is not well characterized. In this present study, our aim is to profile important genes that regulate cellular development during fetal development. Human embryonic carcinoma cells (NCCIT) are cultured to form embryoid bodies and then treated in the presence and absence of ethanol (50 mM). We employed RNA sequencing to profile differentially expressed genes in the ethanol-treated embryoid bodies from NCCIT vs. EB, NCCIT vs. EB+EtOH and EB vs. EB+EtOH data sets. A total of 632, 205 and 517 differentially expressed genes were identified from NCCIT vs. EB, NCCIT vs. EB+EtOH and EB vs. EB+EtOH, respectively. Functional annotation using bioinformatics tools reveal significant enrichment of differential cellular development and developmental disorders. Furthermore, a group of 42, 15 and 35 transcription factor-encoding genes are screened from all of the differentially expressed genes obtained from NCCIT vs. EB, NCCIT vs. EB+EtOH and EB vs. EB+EtOH, respectively. We validated relative gene expression levels of several transcription factors from these lists by quantitative real-time PCR. We hope that our study substantially contributes to the understanding of the molecular mechanism underlying the pathology of alcohol-mediated anomalies and ease further research.

An Embryonic and Induced Pluripotent Stem Cell Model for Ovarian Granulosa Cell Development and Steroidogenesis.

PubMed

Lipskind, Shane; Lindsey, Jennifer S; Gerami-Naini, Behzad; Eaton, Jennifer L; O'Connell, Daniel; Kiezun, Adam; Ho, Joshua W K; Ng, Nicholas; Parasar, Parveen; Ng, Michelle; Nickerson, Michael; Demirci, Utkan; Maas, Richard; Anchan, Raymond M

2018-05-01

Embryoid bodies (EBs) can serve as a system for evaluating pluripotency, cellular differentiation, and tissue morphogenesis. In this study, we use EBs derived from mouse embryonic stem cells (mESCs) and human amniocyte-derived induced pluripotent stem cells (hAdiPSCs) as a model for ovarian granulosa cell (GC) development and steroidogenic cell commitment. We demonstrated that spontaneously differentiated murine EBs (mEBs) and human EBs (hEBs) displayed ovarian GC markers, such as aromatase (CYP19A1), FOXL2, AMHR2, FSHR, and GJA1. Comparative microarray analysis identified both shared and unique gene expression between mEBs and the maturing mouse ovary. Gene sets related to gonadogenesis, lipid metabolism, and ovarian development were significantly overrepresented in EBs. Of the 29 genes, 15 that were differentially regulated in steroidogenic mEBs displayed temporal expression changes between embryonic, postnatal, and mature ovarian tissues by polymerase chain reaction. Importantly, both mEBs and hEBs were capable of gonadotropin-responsive estradiol (E2) synthesis in vitro (217-759 pg/mL). Live fluorescence-activated cell sorting-sorted AMHR2 + granulosa-like cells from mEBs continued to produce E2 after purification (15.3 pg/mL) and secreted significantly more E2 than AMHR2 - cells (8.6 pg/mL, P < .05). We conclude that spontaneously differentiated EBs of both mESC and hAdiPSC origin can serve as a biologically relevant model for ovarian GC differentiation and steroidogenic cell commitment. These cells should be further investigated for therapeutic uses, such as stem cell-based hormone replacement therapy and in vitro maturation of oocytes.

Influence of electron beam irradiation on the microrheology of incompatible polymer blends: Thread break-up and coalescence

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

van Gisbergen, J.G.M.; Meijer, H.E.H.

1991-01-01

The microrheology of polymer blends as influenced by crosslinks induced in the dispersed phase via electron beam irradiation, is systematically investigated for the model system polystyrene/low density polyethylene (PS/LDPE). Both break-up of threads and coalescence of particles are delayed to a large extent, but are not inhibited completely and occur faster than would be expected for a nonirradiated material with a comparable viscosity. Small amplitude, dynamic rheological measurements indicated that in the irradiated materials a yield stress could exist. In contrast, direct microrheological measurements showed that this yield stress, which would prevent both break-up and coalescence, could not be realizedmore » by EB irradiation. Apparently, the direct study of the microrheology of a blend system is important for the prediction of the development of its morphology and it is not possible to rely only on rheological data obtained via other methods.« less

Channeling implantation of high energy carbon ions in a diamond crystal: Determination of the induced crystal amorphization

NASA Astrophysics Data System (ADS)

Erich, M.; Kokkoris, M.; Fazinić, S.; Petrović, S.

2018-02-01

This work reports on the induced diamond crystal amorphization by 4 MeV carbon ions implanted in the 〈1 0 0〉 oriented crystal and its determination by application of RBS/C and EBS/C techniques. The spectra from the implanted samples were recorded for 1.2, 1.5, 1.75 and 1.9 MeV protons. For the two latter ones the strong resonance of the nuclear elastic scattering 12C(p,p0)12C at 1.737 MeV was explored. The backscattering channeling spectra were successfully fitted and the ion beam induced crystal amorphization depth profile was determined using a phenomenological approach, which is based on the properly defined Gompertz type dechanneling functions for protons in the 〈1 0 0〉 diamond crystal channels and the introduction of the concept of ion beam amorphization, which is implemented through our newly developed computer code CSIM.

Dissecting EB1-microtubule interactions from every direction: using single-molecule visualization and static and dynamic binding measurements

NASA Astrophysics Data System (ADS)

Lopez, Benjamin

2015-03-01

EB1 is an important microtubule associating protein (MAP) that acts as a master coordinator of protein activity at the growing plus-end of the microtubule. We can recapitulate the plus-end binding behavior of EB1 along the entire length of a static microtubule using microtubules polymerized in the presence of the nonhydrolyzable GTP analogs GMPCPP and GTP γS instead of GTP. Through the use of single-molecule TIRF imaging we find that EB1 is highly dynamic (with a sub-second characteristic binding lifetime) and continuously diffusive while bound to the microtubule. We measure the diffusion coefficient, D, through linear fitting to mean-squared displacement of individually labeled proteins, and the binding lifetime, τ, by fitting a single exponential decay to the probability distribution of trajectory lifetimes. In agreement with measurements of other diffusive MAPs, we find that D increases and τ decreases with increasing ionic strength. We also find that D is sensitive to the choice of GTP analog: EB1 proteins bound to GTP γS polymerized microtubules have a D half of that found with GMPCPP polymerized microtubules. To compare these single-molecule measurements to the bulk binding behavior of EB1, we use TIRF imaging to measure the intensity of microtubules coated with EB1-GFP as a function of EB1 concentration. We find that EB1 binding is cooperative and both the quantity of EB1 bound and the dissociation constant are sensitive to GTP analog and ionic concentration. The correlation between binding affinity and D and the cooperative nature of EB1-microtubule binding leads to a decrease in D with increasing EB1 concentration. Interestingly, we also find an increase in τ at high EB1 concentrations, consistent with attractive EB1-microtubule interactions driving the cooperativity. To further understand the nature of the cooperativity we estimate the interaction energy by measuring the association and dissociation rates (kon and koff respectively) at different concentrations of EB1.

Eckols reduce dental pulp inflammation through the ERK1/2 pathway independent of COX-2 inhibition.

PubMed

Paudel, U; Lee, Y H; Kwon, T H; Park, N H; Yun, B S; Hwang, P H; Yi, H K

2014-11-01

The aim of this study was to elucidate the role of 6-6 bieckol (EB1) and pholorofucofuroeckol-A (EB5) from brown seaweed marine algae (Eisenia bicyclis) on lipopolysaccharide (LPS)-induced inflammation in human dental pulp cells (HDPCs). The cytotoxicity of EB1 and EB5 was examined by MTT assay on LPS-induced human dental pulp cells. Their role on expression of inflammatory, odontogenic, and osteogenic molecules was determined by Western blot analysis. The dentin mineralization was checked by alkaline phosphatase activity. The five compounds from E. bicyclis have different structure with non-cytotoxic in HDPCs. EB1 and EB5 showed anti-inflammatory properties and inhibited phosphorylated-extracellular signal-regulated kinase (p-ERK1/2) and phosphorylated-c-jun N-terminal kinases (p-JNK) without any cytotoxicity. In particular, EB1 inhibited cyclooxygenase-2 (COX-2) and p-ERK1/2 signaling, and EB5 inhibited only p-ERK1/2 signaling but not COX-2. Both compounds inhibited nuclear factor kappa-B (NF-κB) translocation. Furthermore, EB1 and EB5 increased dentinogenic and osteogenic molecules, and dentin mineralized via alkaline phosphatase activity (ALP) in LPS-induced HDPCs. This study elucidates that EB1 and EB5 have different types of anti-inflammatory property and help in dentin formation. Therefore, these compounds derived from marine algae of E. bicyclis may be used as selective therapeutic strategies for pulpitis and oral diseases. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Clearance of chlamydial elementary bodies from the conjunctival sac

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

Taylor, H.R.; Velez, V.L.

1987-07-01

The rate of disappearance of inactivated Chlamydia trachomatis elementary body (EB) preparations from the conjunctival sac was studied in monkeys. Direct fluorescent antibody (DFA) cytology showed that the majority of EB had been cleared from the eye within 24 hr of the inoculation of 1 X 10(6) inactivated EB, although small numbers of EB could be detected for up to 144 hr. The rate of clearance in normal and ocular immune animals did not differ, and formalin-killed and UV-inactivated EBs disappeared at a comparable rate. These studies suggest that chlamydial EB are cleared relatively quickly from the eye and supportmore » the notion that EBs detected by DFA cytology indicate the presence of current infection.« less

Studies on the diagnostic value of an immunofluorescence test for EB virus-specific IgM.

PubMed

Edwards, J M; McSwiggan, D A

1974-08-01

A modification of the test for EB virus/IgM introduced by Schmitz and Scherer (1972) is described. It is simple and gives reproducible results.EB virus/IgM was demonstrated in all but one case of infectious mononucleosis and in students with minor illness shown to have acquired EB virus/IgG recently. Unlike the EB virus/IgG, the IgM disappears within a few months. Although the Paul-Bunnell-Davidsohn test is still the test of choice for the diagnosis of infectious mononucleosis, the EB virus/IgM test could be useful to establish a diagnosis of current or recent EB virus infection where the Paul-Bunnell-Davidsohn test was negative or equivocal.

Effects of fiber pre-strain on the healing efficiency of thermoset polymers

NASA Astrophysics Data System (ADS)

Ajisafe, Oludayo

One major challenge that has been facing material self healing is how to heal bigger macroscopic or structural scale damage autonomously, repeatedly, efficiently and at molecular length scale. Different approaches have been used to heal materials. However, none of them can heal macroscopic cracks. Our research group has proposed a novel shape-memory polymer (SMP) based, bio-inspired Close-Then-Heal (CTH) scheme to heal macroscopic cracks in SMP matrix. The most recent development in our group is to use SMP fibers to heal conventional thermosetting polymers according to the CTH scheme. The aim of this study is to further investigate the effect of pre-tension of SMP fibers during the cold-drawing programming on the self-healing efficiency of the conventional thermosetting polymer composites. This was done by fabricating a composite with thermoplastic particles (polycaprolactone) dispersed in a thermosetting polymer matrix (Epon 828). Shape memory fiber pre-tensioned into 3 different groups of 0%, 50% and 100% prestrain, was also embedded into the composite in the longitudinal direction. In this composite, the shape memory effect of the shape memory fibers is utilized for sealing (closing) the cracks and the thermoplastic particles are used for molecular-length scale healing. In this study, 7% by volume of thermoplastic particles was used. Beam specimens were prepared and controlled structural length scale damage was created prior to curing by inserting an aluminum foil of designed thickness in a perpendicular direction to the shape memory fibers before the matrix was allowed to cure. The aluminum sheet was removed post cure to leave a controlled damage. The specimen was healed by fixing the two ends of the beam and heating the sample above the Tg of the shape memory fiber. The recovery force of the sample was recorded and then the beam was tested again to fracture. This fracture healing cycle lasted 7 times. The healing efficiency was evaluated per the peak-tensile load. The Ultrasonic C-scan and SEM were used to examine the healed cracks. It was found that the beams with 100% pre-strained fiber were able to recover repeatedly about 50% of its peak tensile strength; the beams with 50% pre-strained fiber, 43%; and the beams with un-stretched fibers were able to recover about 21% of its original peak tensile strength. Also it was found that the higher the pre-tension the higher the recovery stress seen during the healing cycle.

Insights into EB1 structure and the role of its C-terminal domain for discriminating microtubule tips from the lattice

PubMed Central

Buey, Rubén M.; Mohan, Renu; Leslie, Kris; Walzthoeni, Thomas; Missimer, John H.; Menzel, Andreas; Bjelić, Saša; Bargsten, Katja; Grigoriev, Ilya; Smal, Ihor; Meijering, Erik; Aebersold, Ruedi; Akhmanova, Anna; Steinmetz, Michel O.

2011-01-01

End-binding proteins (EBs) comprise a conserved family of microtubule plus end–tracking proteins. The concerted action of calponin homology (CH), linker, and C-terminal domains of EBs is important for their autonomous microtubule tip tracking, regulation of microtubule dynamics, and recruitment of numerous partners to microtubule ends. Here we report the detailed structural and biochemical analysis of mammalian EBs. Small-angle X-ray scattering, electron microscopy, and chemical cross-linking in combination with mass spectrometry indicate that EBs are elongated molecules with two interacting CH domains, an arrangement reminiscent of that seen in other microtubule- and actin-binding proteins. Removal of the negatively charged C-terminal tail did not affect the overall conformation of EBs; however, it increased the dwell times of EBs on the microtubule lattice in microtubule tip–tracking reconstitution experiments. An even more stable association with the microtubule lattice was observed when the entire negatively charged C-terminal domain of EBs was replaced by a neutral coiled-coil motif. In contrast, the interaction of EBs with growing microtubule tips was not significantly affected by these C-terminal domain mutations. Our data indicate that long-range electrostatic repulsive interactions between the C-terminus and the microtubule lattice drive the specificity of EBs for growing microtubule ends. PMID:21737692

A High Proliferation Rate is Critical for Reproducible and Standardized Embryoid Body Formation from Laminin-521-Based Human Pluripotent Stem Cell Cultures.

PubMed

Dziedzicka, Dominika; Markouli, Christina; Barbé, Lise; Spits, Claudia; Sermon, Karen; Geens, Mieke

2016-12-01

When aiming for homogenous embryoid body (EB) differentiation, the use of equal-sized EBs is required to avoid a size-induced differentiation bias. In this study we developed an efficient and standardized EB formation protocol for human pluripotent stem cells (hPSC) cultured in a laminin-521-based xeno-free system. As the cell proliferation rate of the cells growing on laminin-521 strongly affected the efficiency of aggregate formation, we found that recently passaged cells, as well as the addition of ROCK inhibitor, were essential for reproducible EB formation from hPSC single-cell suspensions. EBs could be obtained in a variety of differentiation media, in 96-well round-bottom plates and in hanging drops. Gene expression studies on differentially sized EBs from three individual human embryonic stem cell lines demonstrated that the medium used for differentiation influenced the differentiation outcome to a much greater extent than the number of cells used for the initial EB formation. Our findings give a new insight into factors that influence the EB formation and differentiation process. This optimized method allows us to easily manipulate EB formation and provide an excellent starting point for downstream EB-based differentiation protocols.

Development of new and improved polymer matrix resin systems, phase 1

NASA Technical Reports Server (NTRS)

Hsu, M. S.

1983-01-01

Vinystilbazole (vinylstryrylpyridine) and vinylpolystyrulpyridine were prepared for the purpose of modifying bismaleimide composite resins. Cure studies of resins systems were investigated by differential scanning calorimetry. The vinylstyrylpyridine-modified bismaleimide composite resins were found to have lower cure and gel temperatures, and shorter cure times than the corresponding unmodified composite resins. The resin systems were reinforced with commercially avialable satin-weave carbon cloth. Prepregs were fabricated by solvent or hot melt techniques. Thermal stability, flammability, moisture absorption, and mechanical properties of the composites (such as flexural strength, modulus, tensile and short beam shear strength) were determined. Composite laminates showed substantial improvements in both processability and mechanical properties compared to he bismaleimide control systems. The vinylstyrylpyridine modified bismaleimide resins can be used as advanced matrix resins for graphite secondary structures where ease of processing, fireworthiness, and high temperature stability are required for aerospace applications.

Effect of light curing units on the polymerization of bulk fill resin-based composites.

PubMed

Shimokawa, Carlos Alberto Kenji; Turbino, Míriam Lacalle; Giannini, Marcelo; Braga, Roberto Ruggiero; Price, Richard Bengt

2018-05-22

To determine the potential effect of four different light curing units (LCUs) on the curing profile of two bulk fill resin-based composites (RBCs). Four LCUs (Bluephase 20i, Celalux 3, Elipar DeepCure-S and Valo Grand) were used to light cure two RBCs (Filtek Bulk Fill Posterior Restorative and Tetric EvoCeram Bulk Fill). The effective tip diameter, radiant power, radiant emittance, emission spectrum and light beam profile of the LCUs were measured. Knoop microhardness was measured at the top and bottom surfaces of RBC specimens that were 12-mm in diameter and 4-mm deep (n=5). The distribution of the spectral radiant power that was delivered to the surface of the specimen and the light transmission through the 4-mm thick specimens was measured using an integrating sphere. Two-way ANOVA and Tukey tests (α=0.05) were applied. The Valo Grand produced the most homogeneous microhardness across the surfaces of the RBCs (p>0.05). When the Celalux 3, Bluephase 20i and Elipar DeepCure-S lights were used, the center of the specimens achieved greater hardness values compared to their outer regions (p<0.05). Approximately 10% of the radiant power delivered to the top reached the bottom of the specimen, although almost no violet light passed through 4mm of either RBC. A positive correlation was observed between the radiant exposure and microhardness. The characteristics of the LCUs influenced the photoactivation of the RBCs. The use of a wide tip with a homogeneous light distribution is preferred when light curing RBCs using a bulk curing technique. Copyright © 2018. Published by Elsevier Inc.

Recommendations for the connection between full-depth precast bridge deck panel systems and precast I-beams.

DOT National Transportation Integrated Search

2007-01-01

Precast bridge deck panels can be used in place of a cast-in-place concrete deck to reduce bridge closure times for deck replacements or new bridge construction. The panels are prefabricated at a precasting plant providing optimal casting and curing ...

Toxic effects of sub-chronic exposure of male albino rats to emamectin benzoate and possible ameliorative role of Foeniculum vulgare essential oil.

PubMed

El-Sheikh, El-Sayed A; Galal, Azza A A

2015-05-01

Emamectin benzoate (EB) is an avermectin insecticide used extensively in pest control on vegetable and field crops. Few studies have been done for evaluating adverse effects of EB. In the current study, we evaluated the toxic effects of EB on male rats and the possible ameliorative role of fennel essential oil (FEO). Thirty two male rats were randomly divided into 4 equal groups. All groups were treated orally with distilled water (control group), 0.5mlFEOkg(-1) BW (FEO group), 2.5mgEBkg(-1) BW (EB group), and 0.5mlFEOkg(-1) BW+2.5mgEBkg(-1) BW (FEO+EB group) for 28 days. The obtained results showed that EB treatment resulted in a significant decrease in body weight, body weight gain, RBC count, Hb concentration, % PCV, MCV and MCHC. Moreover, EB significantly decreased total leukocyte, lymphocyte, monocyte and platelet count but significantly increased granulocyte count. EB markedly decreased total protein, albumin, globulin, IgG and IgM concentrations with a significant increase in TNF-α secretion. EB had a negative impact on the liver as it significantly increased ALT, ALP, and MDA, while decreasing SOD activity. Regarding to the histopathological examination, EB treatment induced coagulative necrosis and blood vessels congestion of the liver in treated rats. Furthermore, it resulted in depletion and necrosis of the white pulp of the spleen in treated rats. The co-administration of FEO with EB, however, improved the majority of parameters studied, suggesting that FEO is an important substance in decreasing toxic effects of EB. Copyright © 2015 Elsevier B.V. All rights reserved.

Anaerobic Degradation of Ethylbenzene by a New Type of Marine Sulfate-Reducing Bacterium

PubMed Central

Kniemeyer, Olaf; Fischer, Thomas; Wilkes, Heinz; Glöckner, Frank Oliver; Widdel, Friedrich

2003-01-01

Anaerobic degradation of the aromatic hydrocarbon ethylbenzene was studied with sulfate as the electron acceptor. Enrichment cultures prepared with marine sediment samples from different locations showed ethylbenzene-dependent reduction of sulfate to sulfide and always contained a characteristic cell type that formed gas vesicles towards the end of growth. A pure culture of this cell type, strain EbS7, was isolated from sediment from Guaymas Basin (Gulf of California). Complete mineralization of ethylbenzene coupled to sulfate reduction was demonstrated in growth experiments with strain EbS7. Sequence analysis of the 16S rRNA gene revealed a close relationship between strain EbS7 and the previously described marine sulfate-reducing strains NaphS2 and mXyS1 (similarity values, 97.6 and 96.2%, respectively), which grow anaerobically with naphthalene and m-xylene, respectively. However, strain EbS7 did not oxidize naphthalene, m-xylene, or toluene. Other compounds utilized by strain EbS7 were phenylacetate, 3-phenylpropionate, formate, n-hexanoate, lactate, and pyruvate. 1-Phenylethanol and acetophenone, the characteristic intermediates in anaerobic ethylbenzene degradation by denitrifying bacteria, neither served as growth substrates nor were detectable as metabolites by gas chromatography-mass spectrometry in ethylbenzene-grown cultures of strain EbS7. Rather, (1-phenylethyl)succinate and 4-phenylpentanoate were detected as specific metabolites in such cultures. Formation of these intermediates can be explained by a reaction sequence involving addition of the benzyl carbon atom of ethylbenzene to fumarate, carbon skeleton rearrangement of the succinate moiety (as a thioester), and loss of one carboxyl group. Such reactions are analogous to those suggested for anaerobic n-alkane degradation and thus differ from the initial reactions in anaerobic ethylbenzene degradation by denitrifying bacteria which employ dehydrogenations. PMID:12570993

Deposition and characterization of titania-silica optical multilayers by asymmetric bipolar pulsed dc sputtering of oxide targets

NASA Astrophysics Data System (ADS)

Sagdeo, P. R.; Shinde, D. D.; Misal, J. S.; Kamble, N. M.; Tokas, R. B.; Biswas, A.; Poswal, A. K.; Thakur, S.; Bhattacharyya, D.; Sahoo, N. K.; Sabharwal, S. C.

2010-02-01

Titania-silica (TiO2/SiO2) optical multilayer structures have been conventionally deposited by reactive sputtering of metallic targets. In order to overcome the problems of arcing, target poisoning and low deposition rates encountered there, the application of oxide targets was investigated in this work with asymmetric bipolar pulsed dc magnetron sputtering. In order to evaluate the usefulness of this deposition methodology, an electric field optimized Fabry Perot mirror for He-Cd laser (λ = 441.6 nm) spectroscopy was deposited and characterized. For comparison, this mirror was also deposited by the reactive electron beam (EB) evaporation technique. The mirrors developed by the two complementary techniques were investigated for their microstructural and optical reflection properties invoking atomic force microscopy, ellipsometry, grazing incidence reflectometry and spectrophotometry. From these measurements the layer geometry, optical constants, mass density, topography, surface and interface roughness and disorder parameters were evaluated. The microstructural properties and spectral functional characteristics of the pulsed dc sputtered multilayer mirror were found to be distinctively superior to the EB deposited mirror. The knowledge gathered during this study has been utilized to develop a 21-layer high-pass edge filter for radio photoluminescence dosimetry.

Improved Thermal Cycling Durability of Thermal Barrier Coatings Manufactured by PS-PVD

NASA Astrophysics Data System (ADS)

Rezanka, S.; Mauer, G.; Vaßen, R.

2014-01-01

The plasma spray-physical vapor deposition (PS-PVD) process is a promising method to manufacture thermal barrier coatings (TBCs). It fills the gap between traditional thermal spray processes and electron beam physical vapor deposition (EB-PVD). The durability of PS-PVD manufactured columnar TBCs is strongly influenced by the compatibility of the metallic bondcoat (BC) and the ceramic TBC. Earlier investigations have shown that a smooth BC surface is beneficial for the durability during thermal cycling. Further improvements of the bonding between BC and TBC could be achieved by optimizing the formation of the thermally grown oxide (TGO) layer. In the present study, the parameters of pre-heating and deposition of the first coating layer were investigated in order to adjust the growth of the TGO. Finally, the durability of the PS-PVD coatings was improved while the main advantage of PS-PVD, i.e., much higher deposition rate in comparison to EB-PVD, could be maintained. For such coatings, improved thermal cycling lifetimes more than two times higher than conventionally sprayed TBCs, were measured in burner rigs at ~1250 °C/1050 °C surface/substrate exposure temperatures.

Kinematics of mechanical and adhesional micromanipulation under a scanning electron microscope

NASA Astrophysics Data System (ADS)

Saito, Shigeki; Miyazaki, Hideki T.; Sato, Tomomasa; Takahashi, Kunio

2002-11-01

In this paper, the kinematics of mechanical and adhesional micromanipulation using a needle-shaped tool under a scanning electron microscope is analyzed. A mode diagram is derived to indicate the possible micro-object behavior for the specified operational conditions. Based on the diagram, a reasonable method for pick and place operation is proposed. The keys to successful analysis are to introduce adhesional and rolling-resistance factors into the kinematic system consisting of a sphere, a needle-shaped tool, and a substrate, and to consider the time dependence of these factors due to the electron-beam (EB) irradiation. Adhesional force and the lower limit of maximum rolling resistance are evaluated quantitatively in theoretical and experimental ways. This analysis shows that it is possible to control the fracture of either the tool-sphere or substrate-sphere interface of the system selectively by the tool-loading angle and that such a selective fracture of the interfaces enables reliable pick or place operation even under EB irradiation. Although the conventional micromanipulation was not repeatable because the technique was based on an empirically effective method, this analysis should provide us with a guideline to reliable micromanipulation.

External-RBS, PIXE and NRA analysis for ancient swords

NASA Astrophysics Data System (ADS)

Santos, Hellen C.; Added, Nemitala; Silva, Tiago F.; Rodrigues, C. L.

2015-02-01

Elemental composition of the steel of two ancient swords (Japanese and Damascus from a private collection) was characterized using in air IBA techniques. Our results contribute for the understanding the processes of manufacturing (hammering and quenching) and surface treatments applied in these swords. The Particle Induced X-ray Emission (PIXE) measurements along the Damascus blade allowed to identify and to trace a superficial concentration profile for the elements such Cr, Mn, Fe, Ni, Cu, Zn and As, while results for the Japanese blade showed only the presence of iron. The carbon content on the surface was also investigated using a resonant region in the Elastic Backscattering Spectrometry (EBS) measurements and the results have shown a slightly difference between the surfaces under investigation. In order to investigate the nitrogen content on surface, that could explain the hardening process, we used Nuclear Reaction Analysis (NRA) and the results shown that nitrogen content was under our detection limit for the technique (0.3% in mass). The measurements of PIXE, NRA and EBS were taken using the external beam setup installed at Lamfi - São Paulo/Brazil, the latter being successfully implemented for the first time in this facility.

A full 3D model of fluid flow and heat transfer in an E.B. heated liquid metal bath

NASA Astrophysics Data System (ADS)

Matveichev, A.; Jardy, A.; Bellot, J. P.

2016-07-01

In order to study the dissolution of exogeneous inclusions in the liquid metal during processing of titanium alloys, a series of dipping experiments has been performed in an Electron Beam Melting laboratory furnace. Precise determination of the dissolution kinetics requires knowing and mastering the exact thermohydrodynamic behavior of the melt pool, which implies full 3D modeling of the process. To achieve this goal, one needs to describe momentum and heat transfer, phase change, as well as the development of flow turbulence in the liquid. EB power input, thermal radiation, heat loss through the cooling circuit, surface tension effects (i.e. Marangoni-induced flow) must also be addressed in the model. Therefore a new solver dealing with all these phenomena was implemented within OpenFOAM platform. Numerical results were compared with experimental data from actual Ti melting, showing a pretty good agreement. In the second stage, the immersion of a refractory sample rod in the liquid pool was simulated. Results of the simulations showed that the introduction of the sample slightly disturbs the flow field inside the bath. The amount of such disturbance depends on the exact location of the dipping.

Impact of inherited epidermolysis bullosa on parental interpersonal relationships, marital status and family size.

PubMed

Fine, J-D; Johnson, L B; Weiner, M; Suchindran, C

2005-05-01

The presence in a family of a child or children with epidermolysis bullosa (EB) may have profound psychological implications for other family members. To assess the impact of the presence of EB in one or more children on the personal relationships between their parents. Standardized questionnaires were used. In general, the presence of a child severely affected with EB had profound effects on many aspects of marriage. This included a lack of interest in participating in activities as couples [junctional EB (JEB), 45%; recessive dystrophic EB (RDEB), 25%], a lack of energy to invest in such pursuits (JEB, 82%; RDEB, 50%), limitations in opportunities for sharing nonintimate physical activities (reported by most parents having children with some type of generalized EB), and negatively altered parental sex life (JEB, 55%; RDEB, 39%). This is consistent with the fact that 10%, 64%, 25% and 36% of parents of an affected child with EB simplex (EBS), JEB, dominant dystrophic EB (DDEB) and RDEB, respectively, characterized their relationships as couples as revolving almost exclusively around the day-to-day care of their affected children. The severity of disease in an affected child clearly influenced parental decisions about having more children: 24% and 64% of parents of children with JEB and RDEB, respectively, chose not to have additional children, compared with 26% and 54% of parents with children having EBS or DDEB. This choice was most often pursued via tubal ligation; less often, alternative means of surgical sterilization were chosen. Divorce was common among parents of children with EB (range: 17% in EBS to 31% in JEB) and, with the exception of parents of children with EBS, was usually directly attributed by one or both parents to the profound impact that this disease had exerted on their marriage. Physicians caring for children with EB need to give more consideration to the many psychological factors that may contribute to their patients' well being. They may need to assist these children's parents in seeking support and counselling to prevent destruction of the family unit.

The EB Factory: Fundamental Stellar Astrophysics with Eclipsing Binary Stars Discovered by Kepler

NASA Astrophysics Data System (ADS)

Stassun, Keivan

Eclipsing binaries (EBs) are key laboratories for determining the fundamental properties of stars. EBs are therefore foundational objects for constraining stellar evolution models, which in turn are central to determinations of stellar mass functions, of exoplanet properties, and many other areas. The primary goal of this proposal is to mine the Kepler mission light curves for: (1) EBs that include a subgiant star, from which precise ages can be derived and which can thus serve as critically needed age benchmarks; and within these, (2) long-period EBs that include low-mass M stars or brown dwarfs, which are increa-singly becoming the focus of exoplanet searches, but for which there are the fewest available fundamental mass- radius-age benchmarks. A secondary goal of this proposal is to develop an end-to-end computational pipeline -- the Kepler EB Factory -- that allows automatic processing of Kepler light curves for EBs, from period finding, to object classification, to determination of EB physical properties for the most scientifically interesting EBs, and finally to accurate modeling of these EBs for detailed tests and benchmarking of theoretical stellar evolution models. We will integrate the most successful algorithms into a single, cohesive workflow environment, and apply this 'Kepler EB Factory' to the full public Kepler dataset to find and characterize new "benchmark grade" EBs, and will disseminate both the enhanced data products from this pipeline and the pipeline itself to the broader NASA science community. The proposed work responds directly to two of the defined Research Areas of the NASA Astrophysics Data Analysis Program (ADAP), specifically Research Area #2 (Stellar Astrophysics) and Research Area #9 (Astrophysical Databases). To be clear, our primary goal is the fundamental stellar astrophysics that will be enabled by the discovery and analysis of relatively rare, benchmark-grade EBs in the Kepler dataset. At the same time, to enable this goal will require bringing a suite of extant and new custom algorithms to bear on the Kepler data, and thus our development of the Kepler EB Factory represents a value-added product that will allow the widest scientific impact of the in-formation locked within the vast reservoir of the Kepler light curves.

Performance et caracterisation a l'arrachement des tiges en FRP de carbone utilisees pour renforcement au cisaillement par la methode ETS

NASA Astrophysics Data System (ADS)

Ammar Khodja, L'Hady

The rehabilitation and strengthening concrete structures in shear using composite materials such as externally bonded (EB) or near surface mounted rebar (NSMR) are well established techniques. However, debonding of these strengthening materials is still present and constitute the principal cause of shear failure of beams strengthened with composite materials. A new method called ETS (Embedded Through Section) was recently developed in order to avoid premature failures due to debonding of composite materials. The objective of this study is to highlight the importance and influence of important parameters on the behavior of CFRP bars anchorages subjected to pullout forces. These parameters are: concrete strength, anchorage length of CFRP bars, hole diameter in concrete, diameter of the bar and CFRP surface type (smooth versus sanded). Understanding the influence of these parameters on the relationship between the pullout force and the slip is paramount. This allows an accurate description of the behavior of all elements that contribute to the resistance of the CFRP bars pullout. A series of 25 specimens were subjected to pullout tests. The impact of these parameters on the pullout performance of CFRP rods is summarized in terms of failure mode, ultimate tensile strength and loading force slip relationship. The results of these investigations show that using the ETS method, failure of the anchors can be avoided by providing adequate anchorage length and concrete strength. The method provides greater confinement and thus leads to a substantial improvement in the performance of anchors. As a result, designers will be able to avoid failures that are due to debonding of anchors using thereby the full capabilities of reinforced beams strengthened in shear with EB FRP. Keywords: ETS method, shear, strengthening, anchor, slip, FRP, NSM.

Worldwide U.S. Active Duty Military Deaths: Alphabetical Index by Name, (Aakhus Daniel Joseph - Zysk Carol Rose), October 1, 1979 thru September 30, 1993

DTIC Science & Technology

1994-03-01

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MAGNETIC FLUX CANCELLATION IN ELLERMAN BOMBS

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

Reid, A.; Mathioudakis, M.; Nelson, C. J.

2016-06-01

Ellerman Bombs (EBs) are often found to be co-spatial with bipolar photospheric magnetic fields. We use H α imaging spectroscopy along with Fe i 6302.5 Å spectropolarimetry from the Swedish 1 m Solar Telescope (SST), combined with data from the Solar Dynamic Observatory , to study EBs and the evolution of the local magnetic fields at EB locations. EBs are found via an EB detection and tracking algorithm. Using NICOLE inversions of the spectropolarimetric data, we find that, on average, (3.43 ± 0.49) × 10{sup 24} erg of stored magnetic energy disappears from the bipolar region during EB burning. Themore » inversions also show flux cancellation rates of 10{sup 14}–10{sup 15} Mx s{sup −1} and temperature enhancements of 200 K at the detection footpoints. We investigate the near-simultaneous flaring of EBs due to co-temporal flux emergence from a sunspot, which shows a decrease in transverse velocity when interacting with an existing, stationary area of opposite polarity magnetic flux, resulting in the formation of the EBs. We also show that these EBs can be fueled further by additional, faster moving, negative magnetic flux regions.« less

Cervical spinal demyelination with ethidium bromide impairs respiratory (phrenic) activity and forelimb motor behavior in rats

PubMed Central

Nichols, Nicole L.; Punzo, Antonio M.; Duncan, Ian D.; Mitchell, Gordon S.; Johnson, Rebecca A.

2012-01-01

Although respiratory complications are a major cause of morbidity/mortality in many neural injuries or diseases, little is known concerning mechanisms whereby deficient myelin impairs breathing, or how patients compensate for such changes. Here, we tested the hypothesis that respiratory and forelimb motor function are impaired in a rat model of focal dorsolateral spinal demyelination (ethidium bromide, EB). Ventilation, phrenic nerve activity and horizontal ladder walking were performed 7-14 days post-C2 injection of EB or vehicle (SHAM). EB caused dorsolateral demyelination at C2-C3 followed by signficant spontaneous remyelination at 14 days post-EB. Although ventilation did not differ between groups, ipsilateral integrated phrenic nerve burst amplitude was significantly reduced versus SHAM during chemoreceptor activation at 7 days post-EB but recovered by 14 days. The ratio of ipsi- to contralateral phrenic nerve amplitude correlated with cross-sectional lesion area. This ratio was significantly reduced 7 days post-EB versus SHAM during baseline conditions, and versus SHAM and 14 day groups during chemoreceptor activation. Limb function ipsilateral to EB was impaired 7 days post-EB and partially recovered by 14 days post-EB. EB provides a reversible model of focal, spinal demyelination, and may be a useful model to study mechanisms of functional impairment and recovery via motor plasticity, or the efficacy of new therapeutic interventions to reduce severity or duration of disease. PMID:23159317

The PHD-containing protein EARLY BOLTING IN SHORT DAYS regulates seed dormancy in Arabidopsis.

PubMed

Narro-Diego, Laura; López-González, Leticia; Jarillo, Jose A; Piñeiro, Manuel

2017-10-01

The Arabidopsis protein EARLY BOLTING IN SHORT DAYS (EBS), a plant-specific transcriptional regulator, is involved in the control of flowering time by repressing the floral integrator FT. The EBS protein binds the H3K4me3 histone mark and interacts with histone deacetylases to modulate gene expression. Here, we show that EBS also participates in the regulation of seed dormancy. ebs mutations cause a reduction in seed dormancy, and the concurrent loss of function of the EBS homologue SHORT LIFE (SHL) enhances this dormancy alteration. Transcriptomic analyses in ebs mutant seeds uncovered the misregulation of several regulators of seed dormancy including the MADS box gene AGAMOUS-LIKE67 (AGL67). AGL67 interacts genetically with EBS in seed dormancy regulation, indicating that both loci act in the same pathway. Interestingly, EBS functions independently of the master regulator gene of dormancy DELAY OF GERMINATION 1 (DOG1) and other genes encoding chromatin remodelling factors involved in the control of seed dormancy. Altogether, these data show that EBS is a central repressor of germination during seed dormancy and that SHL acts redundantly with EBS in the control of this developmental process. Our observations suggest that a tightly regulated crosstalk among histone modifications is necessary for a proper control of seed dormancy. © 2017 John Wiley & Sons Ltd.

Inhibition of Vaccinia virus entry by a broad spectrum antiviral peptide

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

Altmann, S.E.; Jones, J.C.; Schultz-Cherry, S.

2009-06-05

Concerns about the possible use of Variola virus, the causative agent of smallpox, as a weapon for bioterrorism have led to renewed efforts to identify new antivirals against orthopoxviruses. We identified a peptide, EB, which inhibited infection by Vaccinia virus with an EC{sub 50} of 15 muM. A control peptide, EBX, identical in composition to EB but differing in sequence, was inactive (EC{sub 50} > 200 muM), indicating sequence specificity. The inhibition was reversed upon removal of the peptide, and EB treatment had no effect on the physical integrity of virus particles as determined by electron microscopy. Viral adsorption wasmore » unaffected by the presence of EB, and the addition of EB post-entry had no effect on viral titers or on early gene expression. The addition of EB post-adsorption resulted in the inhibition of beta-galactosidase expression from an early viral promoter with an EC{sub 50} of 45 muM. A significant reduction in virus entry was detected in the presence of the peptide when the number of viral cores released into the cytoplasm was quantified. Electron microscopy indicated that 88% of the virions remained on the surface of cells in the presence of EB, compared to 37% in the control (p < 0.001). EB also blocked fusion-from-within, suggesting that virus infection is inhibited at the fusion step. Analysis of EB derivatives suggested that peptide length may be important for the activity of EB. The EB peptide is, to our knowledge, the first known small molecule inhibitor of Vaccinia virus entry.« less

Retrofitting of Reinforced Concrete Beams using Reactive Powder Concrete (RPC)

NASA Astrophysics Data System (ADS)

Karthik, S.; Sundaravadivelu, Karthik

2017-07-01

Strengthening of existing damaged structures is one of the leading studies in civil engineering. The purpose of retrofitting is to structurally treat the member with an aim to restore the structure to its original strength. The focus of this project is to study the behaviour of damaged Reinforced Concrete beam retrofitted with Reactive Powder Concrete (RPC) Overlay. Reinforced concrete beams of length 1200 mm, width 100 mm and depth 200 mm were casted with M30 grade of concrete in the laboratory and cured for 28 days. One beam is taken as control and are tested under two point loading to find out ultimate load. Remaining beams are subjected to 90 % ultimate load of control beams. The partially damaged beams are retrofitted with Reactive Powder Concrete Overlay at the full tension face of the beam and side overlay depends upon the respectable retrofitting techniques with 10 mm and 20 mm thick layer to find optimum. Materials like steel fibres are added to enhance the ductility by eliminating coarse particle for homogeneity of the structure. Finally, the modes of failure for retrofitted beams are analysed experimentally under two point loading & compared the results with Control beam.

Scattering of a longitudinal Bessel beam by a sphere embedded in an isotropic elastic solid.

PubMed

Leão-Neto, J P; Lopes, J H; Silva, G T

2017-11-01

The scattering of a longitudinal Bessel beam of arbitrary order by a sphere embedded in an isotropic solid matrix is theoretically analyzed. The spherical inclusion can be made of a viscoelastic, elastic, or fluid-filled isotropic material. In the analysis, the absorbing, scattering, and extinction efficiency factors are obtained, e.g., the corresponding power per characteristic beam intensity per sphere's cross-section area. Furthermore, the extended optical theorem, which expresses the extinction efficiency in terms of an integral of the longitudinal scattering function is derived. Several features of zeroth- and first-order Bessel beams scattering in solids are illustrated considering a polymer adhesive (cured) sphere embedded in a stainless steel matrix. For instance, omnidirectional scattering can be achieved by choosing specific values of the half-cone angle of the Bessel beam, which is the beam's geometrical parameter. Additionally, it is demonstrated that mode suppression leads to lower absorption inside the inclusion when compared to plane wave scattering results.

47 CFR 27.1214 - EBS spectrum leasing arrangements and grandfathered leases.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 2 2012-10-01 2012-10-01 false EBS spectrum leasing arrangements and... Educational Broadband Service § 27.1214 EBS spectrum leasing arrangements and grandfathered leases. (a) A licensee in the EBS that is solely utilizing analog transmissions may enter into a spectrum leasing...

Improved crystallinity and dynamic mechanical properties of reclaimed waste tire rubber/EVA blends under the influence of electron beam irradiation

NASA Astrophysics Data System (ADS)

Ramarad, Suganti; Ratnam, Chantara T.; Khalid, Mohammad; Chuah, Abdullah Luqman; Hanson, Svenja

2017-01-01

Dependence on automobiles has led to a huge amount of waste tires produced annually around the globe. In this study, the feasibility of recycling these waste tires by blending reclaimed waste tire rubber (RTR) with poly(ethylene-co-vinyl acetate) (EVA) and electron beam irradiation was studied. The RTR/EVA blends containing 100-0 wt% of RTR were prepared in the internal mixer followed by electron beam (EB) irradiation with doses ranging from 50 to 200 kGy. The processing torques, calorimetric and dynamic mechanical properties of the blends were studied. Blends were found to have lower processing torque indicating easier processability of RTR/EVA blends compared to EVA. RTR domains were found to be dispersed in EVA matrix, whereas, irradiation improved the dispersion of RTR into smaller domains in EVA matrix. Results showed the addition of EVA improves the efficiency of irradiation induced crosslink formation and dynamic mechanical properties of the blends at the expense of the calorimetric properties. Storage and loss modulus of 50 wt% RTR blend was higher than RTR and EVA, suggesting partial miscibility of the blend. Whereas, electron beam irradiation improved the calorimetric properties and dynamic mechanical properties of the blends through redistribution of RTR in smaller domain sizes within EVA.

Investigations on the Influence of Parameters During Electron Beam Surface Hardening Using the Flash Technique

NASA Astrophysics Data System (ADS)

Grafe, S.; Hengst, P.; Buchwalder, A.; Zenker, R.

2018-06-01

The electron beam hardening (EBH) process is one of today’s most innovative industrial technologies. Due to the almost inertia-free deflection of the EB (up to 100 kHz), the energy transfer function can be adapted locally to the component geometry and/or loading conditions. The current state-of-the-art technology is that of EBH with continuous workpiece feed. Due to the large range of parameters, the potentials and limitations of EBH using the flash technique (without workpiece feed) have not been investigated sufficiently to date. The aim of this research was to generate surface isothermal energy transfer within the flash field. This paper examines the effects of selected process parameters on the EBH surface layer microstructure and the properties achieved when treating hardened and tempered C45E steel. When using constant point distribution within the flash field and a constant beam current, surface isothermal energy input was not generated. However, by increasing the deflection frequency, point density and beam current, a more homogeneous EBH surface layer microstructure could be achieved, along with higher surface hardness and greater surface hardening depths. Furthermore, using temperature-controlled power regulation, surface isothermal energy transfer could be realised over a larger area in the centre of the sample.

Anisotropy induced in a silver chloride emulsion by two successive beams of white light perpendicularly polarized

NASA Astrophysics Data System (ADS)

Attia, Mondher; Debrus, Solange; Henriot, M. P.; May, Marie

1983-04-01

This paper is a study of the anisotropy induced in a silver chloride photographic emulsion by two successive beams of white light, linearly polarized at right angle. After the first exposure, the colloidal medium contains silver ellipsoids e generated by the photolysis of silver chloride and silver ellipsoids e b resulting of the partial destruction of some of the previous ones by long wavelengths. This medium is then illuminated by the second beam linearly polarized at right angle of the first beam. Short wavelengths induced silver ellipsoids e' identical to the ellopsoids e but rotated through π/2 with respect to them. As in the first exposure, some of them are partly broken up and transformed into ellipsoids e' b identical to ellipsoids e b but the direction of their major axis. Moreover, the long wavelengths of second exposure transform some of the particles e and e b generated during the first exposure, into smaller ellipsoids e eb and e bb. Finally, the colloidal medium resulting of these two exposures, contains silver chloride and six sorts of silver particles. By calculating the indices of the medium, we show that the wavelengths characterizing the zero birefringence and zero dichroism of the emulsion are dependent on the energies recorded during each of the exposures.

Exchange Bias in Layered GdBaCo2O5.5 Cobaltite

NASA Astrophysics Data System (ADS)

Solin, N. I.; Naumov, S. V.; Telegin, S. V.; Korolev, A. V.

2017-12-01

It is established that excess oxygen content δ influences the exchange bias (EB) in layered GdBa-Co2O5 + δ cobaltite. The EB effect arises in p-type (δ > 0.5) cobaltite and disappears in n-type (δ < 0.5) cobaltite. The main parameters of EB in GdBaCo2O5.52(2) polycrystals are determined, including the field and temperature dependences of EB field H EB , blocking temperature T B , exchange coupling energy J i of antiferromagnet-ferromagnet (AFM-FM) interface, and dimensions of FM clusters. The training effect inherent in systems with EB has been studied. The results are explained in terms of exchange interaction between the FM and AFM phases. It is assumed that the EB originates from the coexistence of Co3+ and Co4+ ions that leads to the formation of monodomain FM clusters in the AFM matrix of cobaltite.

[Chronic active EB virus infection and granular lymphocytes proliferative disorders in Japan].

PubMed

Ishihara, S; Hara, J; Tawa, A; Kawa, K

1996-04-01

To clarify the characteristics of chronic active EB virus infection (CAEBV) in Japan, and to investigate the relation between granular lymphocytes proliferative disorder (GLPD) and EB virus, we conducted a survey through a questionnaire conducted throughout Japan. Among 17 registered patients with CAEBV, 9 developed various types of lymphoproliferative disorders (LPDs), and 6 patients died of LPD. Among 72 cases of GLPD, 43 were CD3-positive and 27 were CD3-negative. EB viral DNA was detected in the peripheral mononuclear cells in 6 of 7 CD3-negative and 1 of 4 CD3-positive cases. These data suggest that EB virus-associated LPDs frequently derive from patients with CAEBV. However, some GLPD patients without CAEBV, especially for CD3-negative GLPD, are associated with EB virus infection. Therefore detection of EB viral DNA is very important to understand the pathogenesis of GLPD.

First report on the pharmacokinetics of tramadol and O-desmethyltramadol in exhaled breath compared to plasma and oral fluid after a single oral dose.

PubMed

Meyer, Markus R; Rosenborg, Staffan; Stenberg, Marta; Beck, Olof

2015-12-01

Exhaled breath (EB) is a promising matrix for bioanalysis of non-volatiles and has been routinely implemented for drugs of abuse analysis. Nothing is known regarding the pharmacokinetics of therapeutics and their metabolites in EB. Therefore, we used tramadol as a model drug. Twelve volunteers received a single oral dose of tramadol and repeated sampling of EB, plasma, and oral fluid (OF) was done for 48 h using a particle filter device for EB and the Quantisal-device for OF. Samples were analyzed with LC-MS/MS and the pharmacokinetic correlations between matrices were investigated. The initial tramadol half-life in EB was shorter than in plasma but it reappeared in EB after 8-24 h. The ratio of O-desmethyltramadol to tramadol was considerably lower in EB and OF compared to plasma. This pilot study compared for the first time the pharmacokinetics of a therapeutic drug and active metabolite in different biomatrices including EB and demonstrated its potential for bioanalysis. Copyright © 2015 Elsevier Inc. All rights reserved.

Measurement of the full-field polymerization shrinkage and depth of cure of dental composites using digital image correlation.

PubMed

Li, Jianying; Fok, Alex S L; Satterthwaite, Julian; Watts, David C

2009-05-01

The aim of this study was to measure the full-field polymerization shrinkage of dental composites using optical image correlation method. Bar specimens of cross-section 4mm x 2mm and length 10mm approximately were light cured with two irradiances, 450 mW/cm(2) and 180 mW/cm(2), respectively. The curing light was generated with Optilux 501 (Kerr) and the two different irradiances were achieved by adjusting the distance between the light tip and the specimen. A single-camera 2D measuring system was used to record the deformation of the composite specimen for 30 min at a frequency of 0.1 Hz. The specimen surface under observation was sprayed with paint to produce sufficient contrast to allow tracking of individual points on the surface. The curing light was applied to one end of the specimen for 40s during which the painted surface was fully covered. After curing, the cover was removed immediately so that deformation of the painted surface could be recorded by the camera. The images were then analyzed with specialist software and the volumetric shrinkage determined along the beam length. A typical shrinkage strain field obtained on a specimen surface was highly non-uniform, even at positions of constant distance from the irradiation surface, indicating possible heterogeneity in material composition and shrinkage behavior in the composite. The maximum volumetric shrinkage strain of approximately 1.5% occurred at a subsurface distance of about 1mm, instead of at the irradiation surface. After reaching its peak value, the shrinkage strain then gradually decreased with increasing distance along the beam length, before leveling off to a value of approximately 0.2% at a distance of 4-5mm. The maximum volumetric shrinkage obtained agreed well with the value of 1.6% reported by the manufacturer for the composite examined in this work. Using irradiance of 180 mW/cm(2) resulted in only slightly less polymerization shrinkage than using irradiance of 450 mW/cm(2). Compared to the other measurement methods, the image correlation method is capable of producing full-field information about the polymerization shrinkage behavior of dental composites.

Targeted Proteolysis of Plectin Isoform 1a Accounts for Hemidesmosome Dysfunction in Mice Mimicking the Dominant Skin Blistering Disease EBS-Ogna

PubMed Central

Walko, Gernot; Vukasinovic, Nevena; Gross, Karin; Fischer, Irmgard; Sibitz, Sabrina; Fuchs, Peter; Reipert, Siegfried; Jungwirth, Ute; Berger, Walter; Salzer, Ulrich; Carugo, Oliviero; Castañón, Maria J.; Wiche, Gerhard

2011-01-01

Autosomal recessive mutations in the cytolinker protein plectin account for the multisystem disorders epidermolysis bullosa simplex (EBS) associated with muscular dystrophy (EBS-MD), pyloric atresia (EBS-PA), and congenital myasthenia (EBS-CMS). In contrast, a dominant missense mutation leads to the disease EBS-Ogna, manifesting exclusively as skin fragility. We have exploited this trait to study the molecular basis of hemidesmosome failure in EBS-Ogna and to reveal the contribution of plectin to hemidesmosome homeostasis. We generated EBS-Ogna knock-in mice mimicking the human phenotype and show that blistering reflects insufficient protein levels of the hemidesmosome-associated plectin isoform 1a. We found that plectin 1a, in contrast to plectin 1c, the major isoform expressed in epidermal keratinocytes, is proteolytically degraded, supporting the notion that degradation of hemidesmosome-anchored plectin is spatially controlled. Using recombinant proteins, we show that the mutation renders plectin's 190-nm-long coiled-coil rod domain more vulnerable to cleavage by calpains and other proteases activated in the epidermis but not in skeletal muscle. Accordingly, treatment of cultured EBS-Ogna keratinocytes as well as of EBS-Ogna mouse skin with calpain inhibitors resulted in increased plectin 1a protein expression levels. Moreover, we report that plectin's rod domain forms dimeric structures that can further associate laterally into remarkably stable (paracrystalline) polymers. We propose focal self-association of plectin molecules as a novel mechanism contributing to hemidesmosome homeostasis and stabilization. PMID:22144912

On the evolution of cured voxel in bulk photopolymerization upon focused Gaussian laser exposure

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

Bhole, Kiran, E-mail: kirandipali@gmail.com; Gandhi, Prasanna; Kundu, T.

Unconstrained depth photopolymerization is emerging as a promising technique for fabrication of several polymer microstructures such as self propagating waveguides, 3D freeform structures by bulk lithography, and polymer nanoparticles by flash exposure. Experimental observations reveal governing physics beyond Beer Lambert's law and scattering effects. This paper seeks to model unconstrained depth photopolymerization using classical nonlinear Schrödinger equation coupled with transient diffusion phenomenon. The beam propagation part of the proposed model considers scattering effects induced due to spatial variation of the refractive index as a function of the beam intensity. The critical curing energy model is used to further predict profilemore » of polymerized voxel. Profiles of photopolymerized voxel simulated using proposed model are compared with the corresponding experimental results for several cases of exposure dose and duration. The comparison shows close match leading to conclusion that the experimentally observed deviation from Beer Lambert's law is indeed due to combined effect of diffusion of photoinitiator and scattering of light because of change in the refractive index.« less

Synthesis of improved phenolic resins

NASA Technical Reports Server (NTRS)

Delano, C. B.; Mcleod, A. H.

1979-01-01

Twenty seven addition cured phenolic resin compositions were prepared and tested for their ability to give char residues comparable to state-of-the-art phenolic resins. Cyanate, epoxy, allyl, acrylate, methacrylate and ethynyl derivatized phenolic oligomers were investigated. The novolac-cyanate and propargyl-novolac resins provided anaerobic char yields at 800 C of 58 percent. A 59 percent char yield was obtained from modified epoxy novolacs. A phosphonitrilic derivative was found to be effective as an additive for increasing char yields. The novolac-cyanate, epoxy-novolac and methacrylate-epoxy-novolac systems were investigated as composite matrices with Thornel 300 graphite fiber. All three resins showed good potential as composite matrices. The free radical cured methacrylate-epoxy-novolac graphite composite provided short beam shear strengths at room temperature of 93.3 MPa (13.5 ksi). The novolac-cyanate graphite composite produced a short beam shear strength of 74 MPa (10.7 ksi) and flexural strength of 1302 MPa (189 ksi) at 177 C. Air heat aging of the novolac-cyanate and epoxy novolac based composites for 12 weeks at 204 C showed good property retention.

A Damage Resistance Comparison Between Candidate Polymer Matrix Composite Feedline Materials

NASA Technical Reports Server (NTRS)

Nettles, A. T

2000-01-01

As part of NASAs focused technology programs for future reusable launch vehicles, a task is underway to study the feasibility of using the polymer matrix composite feedlines instead of metal ones on propulsion systems. This is desirable to reduce weight and manufacturing costs. The task consists of comparing several prototype composite feedlines made by various methods. These methods are electron-beam curing, standard hand lay-up and autoclave cure, solvent assisted resin transfer molding, and thermoplastic tape laying. One of the critical technology drivers for composite components is resistance to foreign objects damage. This paper presents results of an experimental study of the damage resistance of the candidate materials that the prototype feedlines are manufactured from. The materials examined all have a 5-harness weave of IM7 as the fiber constituent (except for the thermoplastic, which is unidirectional tape laid up in a bidirectional configuration). The resin tested were 977-6, PR 520, SE-SA-1, RS-E3 (e-beam curable), Cycom 823 and PEEK. The results showed that the 977-6 and PEEK were the most damage resistant in all tested cases.

High Frequency of Programmed Death-ligand 1 Expression in Emphysematous Bullae-associated Lung Adenocarcinomas.

PubMed

Toyokawa, Gouji; Takada, Kazuki; Okamoto, Tatsuro; Kozuma, Yuka; Matsubara, Taichi; Haratake, Naoki; Takamori, Shinkichi; Akamine, Takaki; Katsura, Masakazu; Shoji, Fumihiro; Oda, Yoshinao; Maehara, Yoshihiko

2017-09-01

Emphysematous bullae (EB) are known to be associated with a high incidence of lung cancer; however, the reason for this has yet to be elucidated. The objective of the present study was to clarify the prevalence of programmed death-ligand-1 (PD-L1) expression in EB-associated lung adenocarcinomas. A total of 369 patients with resected lung adenocarcinoma whose preoperative computed tomography findings were available for the examination of EB were analyzed for PD-L1 expression by immunohistochemistry and evaluated to determine the association between PD-L1 expression and EB-related adenocarcinomas. Among 369 patients, EB and cancer adjoining EB (Ca-ADJ) were identified in 81 (22.0%) and 50 (13.6%) patients, respectively. EB and Ca-ADJ were significantly associated with male gender, a smoking habit, a decreased forced expiratory volume in 1 second, a relatively higher tumor grade, advanced T status and stage, the presence of pleural and vessel invasion, invasive pathologic subtypes, and wild-type epidermal growth factor receptor. Seventy patients (19.0%) were positive for PD-L1 expression, whereas the remaining 299 patients (81.0%) were negative. Thirty-six (44.4%) and 29 (58.0%) of 81 and 50 patients with EB and Ca-ADJ, respectively, were positive for PD-L1 expression, which was shown to be significant by the Fisher exact test (P < .001 and P < .001, respectively). Among the 81 lung adenocarcinomas with EB, Ca-ADJ was significantly associated with PD-L1 expression (P = .021). In a multivariate analysis, the presence of Ca-ADJ was found to be an independent predictor of PD-L1 expression. EB-associated lung adenocarcinomas express PD-L1 protein more frequently than those without EB. Copyright © 2016 Elsevier Inc. All rights reserved.

Evidence-based safety (EBS) management: A new approach to teaching the practice of safety management (SM).

PubMed

Wang, Bing; Wu, Chao; Shi, Bo; Huang, Lang

2017-12-01

In safety management (SM), it is important to make an effective safety decision based on the reliable and sufficient safety-related information. However, many SM failures in organizations occur for a lack of the necessary safety-related information for safety decision-making. Since facts are the important basis and foundation for decision-making, more efforts to seek the best evidence relevant to a particular SM problem would lead to a more effective SM solution. Therefore, the new paradigm for decision-making named "evidence-based practice (EBP)" can hold important implications for SM, because it uses the current best evidence for effective decision-making. Based on a systematic review of existing SM approaches and an analysis of reasons why we need new SM approaches, we created a new SM approach called evidence-based safety (EBS) management by introducing evidence-based practice into SM. It was necessary to create new SM approaches. A new SM approach called EBS was put forward, and the basic questions of EBS such as its definition and core were analyzed in detail. Moreover, the determinants of EBS included manager's attitudes towards EBS; evidence-based consciousness in SM; evidence sources; technical support; EBS human resources; organizational culture; and individual attributes. EBS is a new and effective approach to teaching the practice of SM. Of course, further research on EBS should be carried out to make EBS a reality. Practical applications: Our work can provide a new and effective idea and method to teach the practice of SM. Specifically, EBS proposed in our study can help safety professionals make an effective safety decision based on a firm foundation of high-grade evidence. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights reserved.

Tau regulates the localization and function of End-binding proteins 1 and 3 in developing neuronal cells.

PubMed

Sayas, Carmen Laura; Tortosa, Elena; Bollati, Flavia; Ramírez-Ríos, Sacnicte; Arnal, Isabelle; Avila, Jesús

2015-06-01

The axonal microtubule-associated protein tau is a well-known regulator of microtubule stability in neurons. However, the putative interplay between tau and End-binding proteins 1 and 3 (EB1/3), the core microtubule plus-end tracking proteins, has not been elucidated yet. Here, we show that a cross-talk between tau and EB1/3 exists in developing neuronal cells. Tau and EBs partially colocalize at extending neurites of N1E-115 neuroblastoma cells and axons of primary hippocampal neurons, as shown by confocal immunofluorescence analyses. Tau down-regulation leads to a reduction of EB1/3 comet length, as observed in shRNA-stably depleted neuroblastoma cells and TAU-/- neurons. EB1/3 localization depends on the expression levels and localization of tau protein. Over-expression of tau at high levels induces EBs relocalization to microtubule bundles at extending neurites of N1E-115 cells. In differentiating primary neurons, tau is required for the proper accumulation of EBs at stretches of microtubule bundles at the medial and distal regions of the axon. Tau interacts with EB proteins, as shown by immunoprecipitation in different non-neuronal and neuronal cells and in whole brain lysates. A tau/EB1 direct interaction was corroborated by in vitro pull-down assays. Fluorescence recovery after photobleaching assays performed in neuroblastoma cells confirmed that tau modulates EB3 cellular mobility. In summary, we provide evidence of a new function of tau as a direct regulator of EB proteins in developing neuronal cells. This cross-talk between a classical microtubule-associated protein and a core microtubule plus-end tracking protein may contribute to the fine-tuned regulation of microtubule dynamics and stability during neuronal differentiation. We describe here a novel function for tau as a direct regulator of End binding (EB) proteins in differentiating neuronal cells. EB1/3 cellular mobility and localization in extending neurites and axons is modulated by tau levels and localization. We provide new evidence of the interplay between classical microtubule-associated proteins (MAPs) and "core" microtubule plus-end tracking proteins (+TIPs) during neuronal development. © 2015 International Society for Neurochemistry.

Spin Polarization of Alternate Monatomic Epitaxial [Fe/Co]n Superlattice

NASA Astrophysics Data System (ADS)

Chu, In Chang; Doi, Masaaki; Sahashi, Masashi; Rajanikanth, Ammanabrolu; Takahashi, Yukiko; Hono, Kazuhiro

2012-09-01

The spin polarization (P) of alternate monatomic layered (AML) epitaxial [Fe/Co]n superlattices grown on MgO(001) substrates by electron beam (EB) evaporation has been measured by the point contact Andreev reflection (PCAR) method. The intrinsic transport P of 0.60 was obtained for the AML epitaxial [Fe/Co]n superlattice grown at 75 °C, which is comparable to that of half-metallic Heusler alloys measured by PCAR. The AML epitaxial [Fe/Co]n superlattices on MgO(001), which are expected to possess the B2 ordered structure, show the highest spin polarization of metallic Fe-Co alloy films.

High-Q plasmas in the TFTR tokamak

NASA Astrophysics Data System (ADS)

Jassby, D. L.; Barnes, C. W.; Bell, M. G.; Bitter, M.; Boivin, R.; Bretz, N. L.; Budny, R. V.; Bush, C. E.; Dylla, H. F.; Efthimion, P. C.; Fredrickson, E. D.; Hawryluk, R. J.; Hill, K. W.; Hosea, J.; Hsuan, H.; Janos, A. C.; Jobes, F. C.; Johnson, D. W.; Johnson, L. C.; Kamperschroer, J.; Kieras-Phillips, C.; Kilpatrick, S. J.; LaMarche, P. H.; LeBlanc, B.; Mansfield, D. K.; Marmar, E. S.; McCune, D. C.; McGuire, K. M.; Meade, D. M.; Medley, S. S.; Mikkelsen, D. R.; Mueller, D.; Owens, D. K.; Park, H. K.; Paul, S. F.; Pitcher, S.; Ramsey, A. T.; Redi, M. H.; Sabbagh, S. A.; Scott, S. D.; Snipes, J.; Stevens, J.; Strachan, J. D.; Stratton, B. C.; Synakowski, E. J.; Taylor, G.; Terry, J. L.; Timberlake, J. R.; Towner, H. H.; Ulrickson, M.; von Goeler, S.; Wieland, R. M.; Williams, M.; Wilson, J. R.; Wong, K.-L.; Young, K. M.; Zarnstorff, M. C.; Zweben, S. J.

1991-08-01

In the Tokamak Fusion Test Reactor (TFTR) [Plasma Phys. Controlled Fusion 26, 11 (1984)], the highest neutron source strength Sn and D-D fusion power gain QDD are realized in the neutral-beam-fueled and heated ``supershot'' regime that occurs after extensive wall conditioning to minimize recycling. For the best supershots, Sn increases approximately as P1.8b. The highest-Q shots are characterized by high Te (up to 12 keV), Ti (up to 34 keV), and stored energy (up to 4.7 MJ), highly peaked density profiles, broad Te profiles, and lower Zeff. Replacement of critical areas of the graphite limiter tiles with carbon-fiber composite tiles and improved alignment with the plasma have mitigated the ``carbon bloom.'' Wall conditioning by lithium pellet injection prior to the beam pulse reduces carbon influx and particle recycling. Empirically, QDD increases with decreasing pre-injection carbon radiation, and increases strongly with density peakedness [ne(0)/] during the beam pulse. To date, the best fusion results are Sn=5×1016 n/sec, QDD=1.85×10-3, and neutron yield=4.0×1016 n/pulse, obtained at Ip=1.6-1.9 MA and beam energy Eb=95-103 keV, with nearly balanced co- and counter-injected beam power. Computer simulations of supershot plasmas show that typically 50%-60% of Sn arises from beam-target reactions, with the remainder divided between beam-beam and thermonuclear reactions, the thermonuclear fraction increasing with Pb. The simulations predict that QDT=0.3-0.4 would be obtained for the best present plasma conditions, if half the deuterium neutral beams were to be replaced by tritium beams. Somewhat higher values are calculated if D beams are injected into a predominantly tritium target plasma. The projected central beta of fusion alphas is 0.4%-0.6%, a level sufficient for the study of alpha-induced collective effects.

Production of double repeated B subunit of Shiga toxin 2e at high levels in transgenic lettuce plants as vaccine material for porcine edema disease.

PubMed

Matsui, Takeshi; Takita, Eiji; Sato, Toshio; Aizawa, Michie; Ki, Misa; Kadoyama, Yumiko; Hirano, Kenji; Kinjo, Satoko; Asao, Hiroshi; Kawamoto, Keiko; Kariya, Haruko; Makino, Sou-Ichi; Hamabata, Takashi; Sawada, Kazutoshi; Kato, Ko

2011-08-01

Pig edema disease is a bacterial disease caused by enterohemorrhagic Escherichia coli. E. coli produces Shiga toxin 2e (Stx2e), which is composed of one A subunit (Stx2eA) and five B subunits (Stx2eB). We previously reported production of Stx2eB in lettuce plants as a potential edible vaccine (Matsui et al. in Biosci Biotechnol Biochem 73:1628-1634, 2009). However, the accumulation level was very low, and it was necessary to improve expression of Stx2eB for potential use of this plant-based vaccine. Therefore, in this study, we optimized the Stx2eB expression cassette and found that a double repeated Stx2eB (2× Stx2eB) accumulates to higher levels than a single Stx2eB in cultured tobacco cells. Furthermore, a linker peptide between the two Stx2eB moieties played an important role in maximizing the effects of the double repeat. Finally, we generated transgenic lettuce plants expressing 2× Stx2eB with a suitable linker peptide that accumulate as much as 80 mg per 100 g fresh weight, a level that will allow us to use these transgenic lettuce plants practically to generate vaccine material.

Electric bicycle-related injuries presenting to a provincial hospital in China: A retrospective study.

PubMed

Zhou, Sheng Ang; Ho, Andrew Fu Wah; Ong, Marcus Eng Hock; Liu, Nan; Pek, Pin Pin; Wang, Yi Qing; Jin, Tao; Yan, Guang Zhao; Han, Nan Nan; Li, Gang; Xu, Li Ming; Cai, Wen Wei

2017-06-01

The use of electric bicycles (EBs) in China is growing. In the present study, we aimed to characterize the pattern and outcomes of EB-related injuries presenting to a major general hospital in China.This was a retrospective review of EB-related injuries presenting to Zhejiang Provincial People's Hospital from 2008 to 2011. Cases were identified from medical records according to diagnosis codes. Data captured included demographics, injury characteristics, and outcomes.A total of 3156 cases were reviewed in the present study. There were 1460 cases of traffic accidents, of which 482 cases were EB-related (32.7%). In addition, most of EB-related cases (44.6%) belonged to the 41- to 60-year-old age group. Median injury severity score was 10. Moreover, 34.9% underwent surgery and 24.7% were admitted to intensive care unit. The median hospitalization cost was 14,269 USD. Fracture (56.5%) was the most frequently diagnosed injury type, and head was the most commonly injured body region (31.1%).EB-related injuries have become a major health concern, making up a sizeable proportion of injuries presenting to the emergency department. Therefore, it is necessary to establish injury prevention and strategies for EB road safety. Implementation of policy such as compulsory helmet use, as well as popularization of EB road safety education should be considered to improve the current situation of EB-related injuries in China.

Dipole-induced exchange bias.

PubMed

Torres, Felipe; Morales, Rafael; Schuller, Ivan K; Kiwi, Miguel

2017-11-09

The discovery of dipole-induced exchange bias (EB), switching from negative to positive sign, is reported in systems where the antiferromagnet and the ferromagnet are separated by a paramagnetic spacer (AFM-PM-FM). The magnitude and sign of the EB is determined by the cooling field strength and the PM thickness. The same cooling field yields negative EB for thin spacers, and positive EB for thicker ones. The EB decay profile as a function of the spacer thickness, and the change of sign, are attributed to long-ranged dipole coupling. Our model, which accounts quantitatively for the experimental results, ignores the short range interfacial exchange interactions of the usual EB theories. Instead, it retains solely the long range dipole field that allows for the coupling of the FM and AFM across the PM spacer. The experiments allow for novel switching capabilities of long range EB systems, while the theory allows description of the structures where the FM and AFM are not in atomic contact. The results provide a new approach to design novel interacting heterostructures.

Evans Blue Dye: A Revisit of Its Applications in Biomedicine.

PubMed

Yao, Linpeng; Xue, Xing; Yu, Peipei; Ni, Yicheng; Chen, Feng

2018-01-01

Evans blue (EB) dye has owned a long history as a biological dye and diagnostic agent since its first staining application by Herbert McLean Evans in 1914. Due to its high water solubility and slow excretion, as well as its tight binding to serum albumin, EB has been widely used in biomedicine, including its use in estimating blood volume and vascular permeability, detecting lymph nodes, and localizing the tumor lesions. Recently, a series of EB derivatives have been labeled with PET isotopes and can be used as theranostics with a broad potential due to their improved half-life in the blood and reduced release. Some of EB derivatives have even been used in translational applications in clinics. In addition, a novel necrosis-avid feature of EB has recently been reported in some preclinical animal studies. Given all these interesting and important advances in EB study, a comprehensive revisiting of EB has been made in its biomedical applications in the review.

DDA3 associates with microtubule plus ends and orchestrates microtubule dynamics and directional cell migration

PubMed Central

Zhang, Liangyu; Shao, Hengyi; Zhu, Tongge; Xia, Peng; Wang, Zhikai; Liu, Lifang; Yan, Maomao; Hill, Donald L.; Fang, Guowei; Chen, Zhengjun; Wang, Dongmei; Yao, Xuebiao

2013-01-01

Cell motility and adhesion involve orchestrated interaction of microtubules (MTs) with their plus-end tracking proteins (+TIPs). However, the mechanisms underlying regulations of MT dynamics and directional cell migration are still elusive. Here, we show that DDA3-EB1 interaction orchestrates MT plus-end dynamics and facilitates directional cell migration. Biochemical characterizations reveal that DDA3 interacts with EB1 via its SxIP motif within the C-terminal Pro/Ser-rich region. Time-lapse and total internal reflection fluorescence (TIRF) microscopic assays demonstrate that DDA3 exhibits EB1-dependent, MT plus-end loading and tracking. The EB1-based loading of DDA3 is responsible for MT plus-ends stabilization at the cell cortex, which in turn orchestrates directional cell migration. Interestingly, the DDA3-EB1 interaction is potentially regulated by EB1 acetylation, which may account for physiological regulation underlying EGF-elicited cell migration. Thus, the EB1-based function of DDA3 links MT dynamics to directional cell migration. PMID:23652583

EB1 contributes to microtubule bundling and organization, along with root growth, in Arabidopsis thaliana.

PubMed

Molines, Arthur T; Marion, Jessica; Chabout, Salem; Besse, Laetitia; Dompierre, Jim P; Mouille, Grégory; Coquelle, Frédéric M

2018-06-26

Microtubules are involved in plant development and adaptation to their environment, but the sustaining molecular mechanisms remain elusive. Microtubule-End-Binding 1 (EB1) proteins participate in directional root growth in Arabidopsis thaliana. However, a connection to the underlying microtubule array has not been established yet. We show here that EB1 proteins contribute to the organization of cortical microtubules in growing epidermal plant cells, without significant modulation of microtubule dynamics. Using super-resolution STED microscopy and an original quantification approach, we also demonstrate a significant reduction of apparent microtubule bundling in cytoplasmic-EB1-deficient plants, suggesting a function for EB1 in the interaction between adjacent microtubules. Furthermore, we observed root growth defects in EB1-deficient plants, which are not related to cell division impairment. Altogether, our results support a role for EB1 proteins in root development, in part by maintaining the organization of cortical microtubules. © 2018. Published by The Company of Biologists Ltd.

Liquid marble as microbioreactor for bioengineering applications

NASA Astrophysics Data System (ADS)

Sarvi, Fatemeh; Jain, Kanika; Alhasan, Layla; Arbatan, Tina; Shen, Wei; Chan, Peggy P. Y.

2015-12-01

This paper reports the use of liquid marbles (LMs) as miniature bioreactors to produce three-dimensional (3D) spheroids including tumor-like spheriods from cancer cells and embryoid bodies (EBs) from stem cells. A liquid marble microbioreactor is prepared by placing a drop of cell suspension onto a polytetrafluoroethylene (PTFE) particle bed. Without the addition of growth factors, suspended EBs from liquid marbles exhibit spontaneous contraction. These results indicate that the liquid marble provides a suitable microenvironment to induce EB formation and spontaneous cardiac differentiation. The EBs were further plated onto gelatin-coated tissue culture dishes. Plated EBs express mature cardiomyocyte marker cardiac troponinT (cTnT), indicating that these EBs have differentiated into functional cardiomyocytes. The cardiomyocytes generated using this liquid marble approach could be useful for transplantation.

Microbial Safety Improvement of Sea Buckthorn by Electron Beam Irradiation

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

Nemtanu, Monica R.; Minea, R.; Mazilu, Elena

2007-04-23

The commercialization of medicinal plants and/or their products is highly increased in Romania lately. One of the most used herbs is sea buckthorn being well known for its quality with a large potential for curing some diseases. Sea buckthorn can be contaminated with undesirable microorganisms which may affect negatively its quality. The paper presents the results regarding the action of a non-conventional technology meaning electron beam technique on sea buckthorn in order to improve its microbiological quality. Our study revealed that the sea buckthorn microbial load has been improved after 3 kGy irradiation keeping its active principles.

Microbial Safety Improvement of Sea Buckthorn by Electron Beam Irradiation

NASA Astrophysics Data System (ADS)

Nemţanu, Monica R.; Minea, R.; Mazilu, Elena; Rǎdulescu, Nora

2007-04-01

The commercialization of medicinal plants and/or their products is highly increased in Romania lately. One of the most used herbs is sea buckthorn being well known for its quality with a large potential for curing some diseases. Sea buckthorn can be contaminated with undesirable microorganisms which may affect negatively its quality. The paper presents the results regarding the action of a non-conventional technology meaning electron beam technique on sea buckthorn in order to improve its microbiological quality. Our study revealed that the sea buckthorn microbial load has been improved after 3 kGy irradiation keeping its active principles.

Observations and NLTE modeling of Ellerman bombs

NASA Astrophysics Data System (ADS)

Berlicki, A.; Heinzel, P.

2014-07-01

Context. Ellerman bombs (EBs) are short-lived, compact, and spatially well localized emission structures that are observed well in the wings of the hydrogen Hα line. EBs are also observed in the chromospheric CaII lines and in UV continua as bright points located within active regions. Hα line profiles of EBs show a deep absorption at the line center and enhanced emission in the line wings with maxima around ±1 Å from the line center. Similar shapes of the line profiles are observed for the CaII IR line at 8542 Å. In CaII H and K lines the emission peaks are much stronger, and EBs emission is also enhanced in the line center. Aims: It is generally accepted that EBs may be considered as compact microflares located in lower solar atmosphere that contribute to the heating of these low-lying regions, close to the temperature minimum of the atmosphere. However, it is still not clear where exactly the emission of EBs is formed in the solar atmosphere. High-resolution spectrophotometric observations of EBs were used for determining of their physical parameters and construction of semi-empirical models. Obtained models allow us to determine the position of EBs in the solar atmosphere, as well as the vertical structure of the activated EB atmosphere Methods: In our analysis we used observations of EBs obtained in the Hα and CaII H lines with the Dutch Open Telescope (DOT). These one-hour long simultaneous sequences obtained with high temporal and spatial resolution were used to determine the line emissions. To analyze them, we used NLTE numerical codes for the construction of grids of 243 semi-empirical models simulating EBs structures. In this way, the observed emission could be compared with the synthetic line spectra calculated for all such models. Results: For a specific model we found reasonable agreement between the observed and theoretical emission and thus we consider such model as a good approximation to EBs atmospheres. This model is characterized by an enhanced temperature in the lower chromosphere and can be considered as a compact structure (hot spot), which is responsible for the emission observed in the wings of chromospheric lines, in particular in the Hα and CaII H lines. Conclusions: For the first time the set of two lines Hα and CaII H was used to construct semi-empirical models of EBs. Our analysis shows that EBs can be described by a "hot spot" model, with the temperature and/or density increase through a few hundred km atmospheric structure. We confirmed that EBs are located close to the temperature minimum or in the lower chromosphere. Two spectral features (lines in our case), observed simultaneously, significantly strengthen the constraints on a realistic model.

Impact of Active Metabolism on Chlamydia trachomatis Elementary Body Transcript Profile and Infectivity.

PubMed

Grieshaber, Scott; Grieshaber, Nicole; Yang, Hong; Baxter, Briana; Hackstadt, Ted; Omsland, Anders

2018-07-15

Bacteria of the genus Chlamydia include the significant human pathogens Chlamydia trachomatis and C. pneumoniae All chlamydiae are obligate intracellular parasites that depend on infection of a host cell and transition through a biphasic developmental cycle. Following host cell invasion by the infectious elementary body (EB), the pathogen transitions to the replicative but noninfectious reticulate body (RB). Differentiation of the RB back to the EB is essential to generate infectious progeny. While the EB form has historically been regarded as metabolically inert, maintenance of infectivity during incubation with specific nutrients has revealed active maintenance of the infectious phenotype. Using transcriptome sequencing, we show that the transcriptome of extracellular EBs incubated under metabolically stimulating conditions does not cluster with germinating EBs but rather with the transcriptome of EBs isolated directly from infected cells. In addition, the transcriptional profile of the extracellular metabolizing EBs more closely resembled that of EB production than germination. Maintenance of infectivity of extracellular EBs was achieved by metabolizing chemically diverse compounds, including glucose 6-phosphate, ATP, and amino acids, all of which can be found in extracellular environments, including mucosal secretions. We further show that the EB cell type actively maintains infectivity in the inclusion after terminal differentiation. Overall, these findings contribute to the emerging understanding that the EB cell form is actively maintained through metabolic processes after terminal differentiation to facilitate prolonged infectivity within the inclusion and under host cell free conditions, for example, following deposition at mucosal surfaces. IMPORTANCE Chlamydiae are obligate intracellular Gram-negative bacteria that are responsible for a wide range of diseases in both animal and human hosts. According to the Centers for Disease Control and Prevention, C. trachomatis is the most frequently reported sexually transmitted infection in the United States, costing the American health care system nearly $2.4 billion annually. Every year, there are over 4 million new cases of Chlamydia infections in the United States and an estimated 100 million cases worldwide. To cause disease, Chlamydia must successfully complete its complex biphasic developmental cycle, alternating between an infectious cell form (EB) specialized for initiating entry into target cells and a replicative form (RB) specialized for creating and maintaining the intracellular replication niche. The EB cell form has historically been considered metabolically quiescent, a passive entity simply waiting for contact with a host cell to initiate the next round of infection. Recent studies and data presented here demonstrate that the EB maintains its infectious phenotype by actively metabolizing a variety of nutrients. Therefore, the EB appears to have an active role in chlamydial biology, possibly within multiple environments, such as mucosal surfaces, fomites, and inside the host cell after formation. Copyright © 2018 American Society for Microbiology.

A new fabrication technique for complex refractive micro-optical systems

NASA Astrophysics Data System (ADS)

Tormen, Massimo; Carpentiero, Alessandro; Ferrari, Enrico; Cabrini, Stefano; Cojoc, Dan; Di Fabrizio, Enzo

2006-01-01

We present a new method that allows to fabricate structures with tightly controlled three-dimensional profiles in the 10 nm to 100 μm scale range. This consists of a sequence of lithographic steps such as Electron Beam (EB) or Focused Ion Beam (FIB) lithography, alternated with isotropic wet etching processes performed on a quartz substrate. Morphological characterization by SEM and AFM shows that 3D structures with very accurate shape control and nanometer scale surface roughness can be realized. Quartz templates have been employed as complex system of micromirrors after metal coating of the patterned surface or used as stamps in nanoimprint, hot embossing or casting processes to shape complex plastic elements. Compared to other 3D micro and nanostructuring methods, in which a hard material is directly "sculptured" by energetic beams, our technique requires a much less intensive use of expensive lithographic equipments, for comparable volumes of structured material, resulting in dramatic increase of throughput. Refractive micro-optical elements have been fabricated and characterized in transmission and reflection modes with white and monochromatic light. The elements produce a distribution of sharp focal spots and lines in the three dimensional space, opening the route for applications of image reconstruction based on refractive optics.

The EB factory project. II. Validation with the Kepler field in preparation for K2 and TESS

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

Parvizi, Mahmoud; Paegert, Martin; Stassun, Keivan G., E-mail: mahmoud.parvizi@vanderbilt.edu

Large repositories of high precision light curve data, such as the Kepler data set, provide the opportunity to identify astrophysically important eclipsing binary (EB) systems in large quantities. However, the rate of classical “by eye” human analysis restricts complete and efficient mining of EBs from these data using classical techniques. To prepare for mining EBs from the upcoming K2 mission as well as other current missions, we developed an automated end-to-end computational pipeline—the Eclipsing Binary Factory (EBF)—that automatically identifies EBs and classifies them into morphological types. The EBF has been previously tested on ground-based light curves. To assess the performancemore » of the EBF in the context of space-based data, we apply the EBF to the full set of light curves in the Kepler “Q3” Data Release. We compare the EBs identified from this automated approach against the human generated Kepler EB Catalog of ∼2600 EBs. When we require EB classification with ⩾90% confidence, we find that the EBF correctly identifies and classifies eclipsing contact (EC), eclipsing semi-detached (ESD), and eclipsing detached (ED) systems with a false positive rate of only 4%, 4%, and 8%, while complete to 64%, 46%, and 32%, respectively. When classification confidence is relaxed, the EBF identifies and classifies ECs, ESDs, and EDs with a slightly higher false positive rate of 6%, 16%, and 8%, while much more complete to 86%, 74%, and 62%, respectively. Through our processing of the entire Kepler “Q3” data set, we also identify 68 new candidate EBs that may have been missed by the human generated Kepler EB Catalog. We discuss the EBF's potential application to light curve classification for periodic variable stars more generally for current and upcoming surveys like K2 and the Transiting Exoplanet Survey Satellite.« less

The Eb Factory Project. Ii. Validation With the Kepler Field in Preparation for K2 and Tess

NASA Astrophysics Data System (ADS)

Parvizi, Mahmoud; Paegert, Martin; Stassun, Keivan G.

2014-12-01

Large repositories of high precision light curve data, such as the Kepler data set, provide the opportunity to identify astrophysically important eclipsing binary (EB) systems in large quantities. However, the rate of classical “by eye” human analysis restricts complete and efficient mining of EBs from these data using classical techniques. To prepare for mining EBs from the upcoming K2 mission as well as other current missions, we developed an automated end-to-end computational pipeline—the Eclipsing Binary Factory (EBF)—that automatically identifies EBs and classifies them into morphological types. The EBF has been previously tested on ground-based light curves. To assess the performance of the EBF in the context of space-based data, we apply the EBF to the full set of light curves in the Kepler “Q3” Data Release. We compare the EBs identified from this automated approach against the human generated Kepler EB Catalog of ˜ 2600 EBs. When we require EB classification with ≥slant 90% confidence, we find that the EBF correctly identifies and classifies eclipsing contact (EC), eclipsing semi-detached (ESD), and eclipsing detached (ED) systems with a false positive rate of only 4%, 4%, and 8%, while complete to 64%, 46%, and 32%, respectively. When classification confidence is relaxed, the EBF identifies and classifies ECs, ESDs, and EDs with a slightly higher false positive rate of 6%, 16%, and 8%, while much more complete to 86%, 74%, and 62%, respectively. Through our processing of the entire Kepler “Q3” data set, we also identify 68 new candidate EBs that may have been missed by the human generated Kepler EB Catalog. We discuss the EBF's potential application to light curve classification for periodic variable stars more generally for current and upcoming surveys like K2 and the Transiting Exoplanet Survey Satellite.

Electron-beam-initiated polymerization of poly(ethylene glycol)-based wood impregnants.

PubMed

Trey, Stacy M; Netrval, Julia; Berglund, Lars; Johansson, Mats

2010-11-01

The current study demonstrates that methacrylate and acrylate poly(ethylene glycol) (PEG) functional oligomers can be effectively impregnated into wood blocks, and cured efficiently to high conversions without catalyst by e-beam radiation, allowing for less susceptibility to leaching, and favorable properties including higher Brinell hardness values. PEG based monomers were chosen because there is a long history of this water-soluble monomer being able to penetrate the cell wall, thus bulking it and decreasing the uptake of water which further protects the wood from fungal attack. Diacrylate, dimethacrylate, and dihydroxyl functional PEG of M(w) 550-575, of concentrations 0, 30, 60, and 100 wt % in water, were vacuum pressure impregnated into Scots Pine blocks of 15 × 25 × 50 mm in an effort to bulk the cell wall. The samples were then irradiated and compared with nonirradiated samples. It was shown by IR, DSC that the acrylate polymers were fully cured to much higher conversions than can be reached with conventional methods. Leaching studies indicated a much lower amount of oligomer loss from the cured vinyl functional PEG chains in comparison to hydroxyl functional PEG indicating a high degree of fastening of the polymer in the wood. The Brinell hardness indicated a significant increase in hardness to hardwood levels in the modified samples compared to the samples of hydroxyl functional PEG and uncured vinyl PEG samples, which actually became softer than the untreated Scots Pine. By monitoring the dimensions of the sample it was found by weight percent gain calculations (WPG %) that water helps to swell the wood structure and allow better access of the oligomers into the cell wall. Further, the cure shrinkage of the wood samples demonstrated infiltration of the oligomers into the cell wall as this was not observed for methyl methacrylate which is well-documented to remain in the lumen. However, dimensional stability of the vinyl polymer modified blocks when placed in water was not observed to the same extent as PEG.

Electron beam irradiation of gemstone for color enhancement

NASA Astrophysics Data System (ADS)

Idris, Sarada; Ghazali, Zulkafli; Hashim, Siti A'iasah; Ahmad, Shamshad; Jusoh, Mohd Suhaimi

2012-09-01

Numerous treatment of gemstones has been going on for hundreds of years for enhancing color and clarity of gems devoid of these attributes. Whereas previous practices included fraudulent or otherwise processes to achieve the color enhancement, the ionizing radiation has proven to be a reliable and reproducible technique. Three types of irradiation processes include exposure to gamma radiation, electron beam irradiation and the nuclear power plants. Electron Beam Irradiation of Gemstone is a technique in which a gemstone is exposed to highly ionizing radiation electron beam to knock off electrons to generate color centers culminating in introduction of deeper colors. The color centers may be stable or unstable. Below 9MeV, normally no radioactivity is introduced in the exposed gems. A study was conducted at Electron Beam Irradiation Centre (Alurtron) for gemstone color enhancement by using different kind of precious gemstones obtained from Pakistan. The study shows that EB irradiation not only enhances the color but can also improves the clarity of some type of gemstones. The treated stones included kunzite, tourmaline, topaz, quartz, aquamarine and cultured pearls. Doses ranging from 25 kGy to 200 KGy were employed to assess the influence of doses on color and clarity and to select the optimum doses. The samples used included both the natural and the faceted gemstones. It is concluded that significant revenue generation is associated with the enhancement of the color in clarity of gemstones which are available at very cheap price in the world market.

Electron beam irradiation of gemstone for color enhancement

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

Idris, Sarada; Ghazali, Zulkafli; Hashim, Siti A'iasah

2012-09-26

Numerous treatment of gemstones has been going on for hundreds of years for enhancing color and clarity of gems devoid of these attributes. Whereas previous practices included fraudulent or otherwise processes to achieve the color enhancement, the ionizing radiation has proven to be a reliable and reproducible technique. Three types of irradiation processes include exposure to gamma radiation, electron beam irradiation and the nuclear power plants. Electron Beam Irradiation of Gemstone is a technique in which a gemstone is exposed to highly ionizing radiation electron beam to knock off electrons to generate color centers culminating in introduction of deeper colors.more » The color centers may be stable or unstable. Below 9MeV, normally no radioactivity is introduced in the exposed gems. A study was conducted at Electron Beam Irradiation Centre (Alurtron) for gemstone color enhancement by using different kind of precious gemstones obtained from Pakistan. The study shows that EB irradiation not only enhances the color but can also improves the clarity of some type of gemstones. The treated stones included kunzite, tourmaline, topaz, quartz, aquamarine and cultured pearls. Doses ranging from 25 kGy to 200 KGy were employed to assess the influence of doses on color and clarity and to select the optimum doses. The samples used included both the natural and the faceted gemstones. It is concluded that significant revenue generation is associated with the enhancement of the color in clarity of gemstones which are available at very cheap price in the world market.« less

Observations of Ellerman bomb emission features in He I D3 and He I 10 830 Å

NASA Astrophysics Data System (ADS)

Libbrecht, Tine; Joshi, Jayant; Rodríguez, Jaime de la Cruz; Leenaarts, Jorrit; Ramos, Andrés Asensio

2017-02-01

Context. Ellerman bombs (EBs) are short-lived emission features, characterised by extended wing emission in hydrogen Balmer lines. Until now, no distinct signature of EBs has been found in the He I 10 830 Å line, and conclusive observations of EBs in He I D3 have never been reported. Aims: We aim to study the signature of EBs in neutral helium triplet lines. Methods: The observations consisted of ten consecutive SST/TRIPPEL raster scans close to the limb, featuring the Hβ, He I D3 and He I 10 830 Å spectral regions. We also obtained raster scans with IRIS and made use of the SDO/AIA 1700 Å channel. We used Hazel to invert the neutral helium triplet lines. Results: Three EBs in our data show distinct emission signatures in neutral helium triplet lines, most prominently visible in the He I D3 line. The helium lines have two components: a broad and blueshifted emission component associated with the EB, and a narrower absorption component formed in the overlying chromosphere. One of the EBs in our data shows evidence of strong velocity gradients in its emission component. The emission component of the other two EBs could be fitted using a constant slab. Our analysis hints towards thermal Doppler motions having a large contribution to the broadening for helium and IRIS lines. We conclude that the EBs must have high temperatures to exhibit emission signals in neutral helium triplet lines. An order of magnitude estimate places our observed EBs in the range of T 2 × 104-105 K. Movies associated to Figs. 3-5 are available at http://www.aanda.org

[Establishment of sprouting embryoid body model mimicking early embryonic vasculogenesis in human embryo].

PubMed

Jiang, Hua; Feng, You-Ji; Xie, Yi; Han, Jin-Lan; Wang, Zack; Chen, Tong

2008-10-14

To establish a sprouting embryoid body model mimicking early embryonic vasculogenesis in human embryo. Human embryonic stem were (hESCs) were cultured on the mouse embryo fibroblasts and then were induced to differentiate to form three-dimensional EB. The hEBs were cultured in media containing various angiogenesis-related factors: vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), endostatin, angiostatin, and platelet factor (PF)-4 of different concentrations for 3 days to observe the sprouting of the hEBs. 3, 3, 3', 3'-tetramethylindo-carbocyanine perchlorate labeled acetylated low density lipoprotein (Dil-AcLDL) was added onto the hEBs foe 4 h Immunofluorescence assay was used to observe if Dil-AcLDL was absorbed and if CD31 was expressed so as to determine the existence of embryonic endothelial cells in the sprouting structures. The ideal culturing condition was analyzed. The differentiated EBs formed sprouting structures in the collagen I matrix containing VEGF and FGF. The sprouts among individual EBs were able to link to each other and form vascular network-like structures. In the presence of VEGF and FGF, the sprouts branching from the EBs assimilated Dil-AcLDL, expressed CD31 and formed a 3-dimensional cylindrical organization. The concentrations of growth factors ideally stimulating sprouting growth were 100 ng/ml of VEGF and 50 ng/ml of FGF. The networks among the EBs were abolished by the angiostatin, endostatin, and PF4. The sprouting from hEBs accumulates embryonic endothelial cells and the sprouting network-like structures are indeed endothelial in nature. Inducing of sprouting EBs is an ideal model that mimics early embryonic vasculogenesis in humans.

Epidermolysis bullosa care in Germany.

PubMed

Bruckner-Tuderman, Leena

2010-04-01

Until 2003, no structures existed in Germany for special care of patients with rare diseases, such as epidermolysis bullosa (EB). At that point, the Federal Ministry of Education and Research announced a clinical research program-networks for rare diseases. The Network Epidermolysis Bullosa (EB Network), coordinated from the Department of Dermatology, University Medical Center Freiburg, has operated since October 2003 with the goal of improving diagnostics and clinical management, elucidating disease mechanisms, and development of novel therapies for EB (www.netzwerk-eb.de). Future goals of the EB Network include securing the clinical-diagnostic and IT structures established with grant support and focusing research on molecular disease mechanisms in EB and novel biologically valid therapies. Intensive collaborations with other networks for rare genetic diseases will generate durable structures in Germany and form a basis for future international consortia. Copyright 2010 Elsevier Inc. All rights reserved.

Organic solvent-free sugar-based transparency nanopatterning material derived from biomass for eco-friendly optical biochips using green lithography

NASA Astrophysics Data System (ADS)

Takei, Satoshi; Oshima, Akihiro; Oyama, Tomoko G.; Ito, Kenta; Sugahara, Kigenn; Kashiwakura, Miki; Kozawa, Takahiro; Tagawa, Seiichi

2014-05-01

An organic solvent-free sugar-based transparency nanopatterning material which had specific desired properties such as nanostructures of subwavelength grating and moth-eye antireflection, acceptable thermal stability of 160 °C, and low imaginary refractive index of less than 0.005 at 350-800 nm was proposed using electron beam lithography. The organic solvent-free sugar-based transparency nanopatterning material is expected for non-petroleum resources, environmental affair, safety, easiness of handling, and health of the working people, instead of the common developable process of tetramethylammonium hydroxide. 120 nm moth-eye antireflection nanopatterns images with exposure dose of 10 μC/cm2 were provided by specific process conditions of electron beam lithography. The developed sugar derivatives with hydroxyl groups and EB sensitive groups in the organic solvent-free sugar-based transparency nanopatterning material were applicable to future development of optical interface films of biology and electronics as a novel chemical design.

Improved alumina scale adhesion of electron beam physical vapor deposited Dy/Hf-doped β-NiAl coatings

NASA Astrophysics Data System (ADS)

Li, Dongqing; Guo, Hongbo; Peng, Hui; Gong, Shengkai; Xu, Huibin

2013-10-01

The cyclic oxidation behavior of Dy/Hf-doped β-NiAl coatings produced by electron beam physical vapor deposition (EB-PVD) was investigated. For the undoped NiAl coating, numerous voids were formed at the alumina scale/coating interface and large rumpling developed in the scale, leading to premature oxide spallation. The addition of Dy and Hf both improved scale adhesion and the alumina scale grown on the NiAl-Hf coating showed better adhesion than that on the NiAl-Dy coating, although the suppressing effect on interfacial void formation and the scale rumpling resistance were stronger in the NiAl-Dy coating. It is proposed that the segregation of Dy and Hf ions at the scale/coating interfaces not only prevent interfacial sulfur segregation but also may directly enhance interfacial adhesion by participating in bonding across the interfaces, and this strengthening effect is relatively stronger for Hf ionic segregation.

Low Conductive Thermal Barrier Coatings Produced by Ion Beam Assisted EB-PVD with Controlled Porosity, Microstructure Refinement and Alloying Additions for High Temperature Applications

NASA Technical Reports Server (NTRS)

Wolfe, Douglas E.; Singh, Jogender

2005-01-01

Various advanced Hafnia-based thermal barrier coatings (TBC) were applied on nickel-based superalloy coupons by electron beam physical vapor deposition. In addition, microstructural modifications to the coating material were made in an effort to reduce the thermal conductivity of the coating materials. Various processing parameters and coating system modifications were made in order to deposit the alloyed TBC with the desired microstructure and thus coating performance, some of which include applying coatings at substrate temperatures of 1150 C on both PtAl and CoNiCrAlY bond coated samples, as well as using 8YSZ as a bond layer. In addition, various characterization techniques including thermal cyclic tests, scanning electron microscopy, x-ray diffraction, thermal conductivity, and reflectivity measurements were performed. Although the coating microstructure was never fully optimized due to funding being cut short, significant reductions in thermal conductivity were accomplished through both chemistry changes (composition) and microstructural modifications.

Ellerman bombs observed with the new vacuum solar telescope and the atmospheric imaging assembly onboard the solar dynamics observatory

NASA Astrophysics Data System (ADS)

Chen, Yajie; Tian, Hui; Xu, Zhi; Xiang, Yongyuan; Fang, Yuliang; Yang, Zihao

2017-12-01

Ellerman bombs (EBs) are believed to be small-scale reconnection events occurring around the temperature minimum region in the solar atmosphere. They are often identified as significant enhancements in the extended Hα wings without obvious signatures in the Hα core. Here we explore the possibility of using the 1700 Å images taken by the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) to study EBs. From the Hα wing images obtained with the New Vacuum Solar Telescope (NVST) on 2015 May 2, we have identified 145 EBs and 51% of them clearly correspond to the bright points (BPs) in the AIA 1700 Å images. If we resize the NVST images using a linear interpolation to make the pixel sizes of the AIA and NVST images the same, some previously identified EBs disappear and about 71% of the remaining EBs are associated with BPs. Meanwhile, 66% of the compact brightenings in the AIA 1700 Å images can be identified as EBs in the Hα wings. The intensity enhancements of the EBs in the Hα wing images reveal a linear correlation with those of the BPs in the AIA 1700 Å images. Our study suggests that a significant fraction of EBs can be observed with the AIA 1700 Å filter, which is promising for large-sample statistical study of EBs as the seeing-free and full-disk SDO/AIA data are routinely available.

Electric bicycle cost calculation models and analysis based on the social perspective in China.

PubMed

Yan, Xuetong; He, Jie; King, Mark; Hang, Wen; Zhou, Bojian

2018-05-10

Electric bicycles (EBs) are increasingly popular around the world. In April 2014, EB ownership in China reached 181 million. While some aspects of the impact of EBs have been studied, most of the literature analyzing the cost of EBs has been conducted from the buyer's point of view and the perspective of social cost has not been covered, which is therefore the focus of this paper. From the consumer's point of view, only the costs paid from purchase until retirement are included in the cost of EBs, i.e., the EB acquisition cost, battery replacement cost, charging cost, and repair and maintenance cost are included. Considered from the perspective of the social cost (including impact on the environment), costs that are not paid directly by consumers should also be included in the cost of EBs, i.e., the lead-acid battery scrap processing cost, the cost of pollution caused by wastewater, and the traffic-related costs. Data are obtained from secondary sources and surveys, and calculations demonstrate that in the life cycle of an EB, the consumer cost is 6386.2 CNY, the social cost is 10,771.2 CNY, and the ratio of consumer to social cost is 1:1.69. By comparison, the ratio for motor vehicles is 1:1.06, so that the share of the life cycle cost of EBs that is not borne by the consumer is much higher than that for motor vehicles, which needs to be addressed.

Prior minimal endoscopic sphincterotomy to prevent pancreatitis related to endoscopic balloon sphincteroplasty

PubMed Central

Kanazawa, Ryo; Sai, Jin Kan; Ito, Tomoyasu; Miura, Hiroko; Ishii, Shigeto; Saito, Hiroaki; Tomishima, Ko; Shimizu, Ryo; Sato, Koki; Hayashi, Manabu; Watanabe, Sumio; Shiina, Shuichiro

2016-01-01

AIM To investigate the efficacy of prior minimal endoscopic sphincterotomy (EST) to prevent pancreatitis related to endoscopic balloon sphincteroplasty (EBS). METHODS After bile duct access was gained and cholangiogram confirmed the presence of stones < 8 mm in the common bile duct at endoscopic retrograde cholangiography, patients were subjected to minimal EST (up to one-third of the size the papilla) plus 8 mm EBS (EST-EBS group). The incidence of pancreatitis and the difference in serum amylase level after the procedure were examined and compared with those associated with 8-mm EBS alone in 32 patients of historical control (control group). RESULTS One hundred and five patients were included in the EST-EBS group, and complete stone removal was accomplished in all of them. The difference in serum amylase level after the procedure was - 25.0 (217.9) IU/L in the EST-EBS group and this value was significantly lower than the 365.5 (576.3) IU/L observed in the control group (P < 0.001). The incidence of post-procedure pancreatitis was 0% (0/105) in the EST-EBS group and 15.6% (5/32) in the control group (P < 0.001). CONCLUSION Prior minimal EST might be useful to prevent the elevation of serum amylase level and the occurrence of pancreatitis related to EBS. PMID:27803773

Ethidium bromide as a marker of mtDNA replication in living cells

NASA Astrophysics Data System (ADS)

Villa, Anna Maria; Fusi, Paola; Pastori, Valentina; Amicarelli, Giulia; Pozzi, Chiara; Adlerstein, Daniel; Doglia, Silvia Maria

2012-04-01

Mitochondrial DNA (mtDNA) in tumor cells was found to play an important role in maintaining the malignant phenotype. Using laser scanning confocal fluorescence microscopy (LSCFM) in a recent work, we reported a variable fluorescence intensity of ethidium bromide (EB) in mitochondria nucleoids of living carcinoma cells. Since when EB is bound to nucleic acids its fluorescence is intensified; a higher EB fluorescence intensity could reflect a higher DNA accessibility to EB, suggesting a higher mtDNA replication activity. To prove this hypothesis, in the present work we studied, by LSCFM, the EB fluorescence in mitochondria nucleoids of living neuroblastoma cells, a model system in which differentiation affects the level of mtDNA replication. A drastic decrease of fluorescence was observed after differentiation. To correlate EB fluorescence intensity to the mtDNA replication state, we evaluated the mtDNA nascent strands content by ligation-mediated real-time PCR, and we found a halved amount of replicating mtDNA molecules in differentiating cells. A similar result was obtained by BrdU incorporation. These results indicate that the low EB fluorescence of nucleoids in differentiated cells is correlated to a low content of replicating mtDNA, suggesting that EB may be used as a marker of mtDNA replication in living cells.

The microtubule-associated protein EB1 maintains cell polarity through activation of protein kinase C.

PubMed

Schober, Joseph M; Kwon, Guim; Jayne, Debbie; Cain, Jeanine M

2012-01-06

The plus-ends of microtubules target the cell cortex to modulate actin protrusion dynamics and polarity, but little is known of the molecular mechanism that couples the interaction. EB1 protein associates with the plus-ends of microtubules, placing EB1 in an ideal spatial position to mediate microtubule-actin cross talk. The objective of the current study was to further understand intracellular signaling involved in EB1-dependent cell polarity and motility. B16F10 mouse melanoma cells were depleted of EB1 protein using short hair-pin RNA interference. Correlative live cell-immunofluorescence microscopy was performed to determine localization of WAVE2 and IQGAP1 to protruding versus retracting edges. EB1 knock down caused poor subcellular separation of WAVE2 and IQGAP1, and overall decreased localization. Activation of PKC corrected defects in WAVE2 and IQGAP1 localization, cell spreading and cell shape to levels observed in control cells, but did not correct defects in cell migration. Consistent with these findings, decreased PKC phosphorylation was observed in EB1 knock down cells. These findings support a model where EB1 protein links microtubules to actin protrusion and cell polarity through signaling pathways involving PKC. Copyright © 2011 Elsevier Inc. All rights reserved.

Adhesion to root canal dentine using one and two-step adhesives with dual-cure composite core materials.

PubMed

Foxton, R M; Nakajima, M; Tagami, J; Miura, H

2005-02-01

The regional tensile bond strengths of two dual-cure composite resin core materials to root canal dentine using either a one or two-step self-etching adhesive were evaluated. Extracted premolar teeth were decoronated and their root canals prepared to a depth of 8 mm and a width of 1.4 mm. In one group, a one-step self-etching adhesive (Unifil Self-etching Bond) was applied to the walls of the post-space and light-cured for 10 s. After which, the post-spaces were filled with the a dual-cure composite resin (Unifil Core) and then half the specimens were light-cured for 60 s and the other half placed in darkness for 30 min. In the second group, a self-etching primer (ED Primer II) was applied for 30 s, followed by an adhesive resin (Clearfil Photo Bond), which was light-cured for 10 s. The post-spaces were filled with a dual-cure composite resin (DC Core) and then half the specimens were light-cured for 60 s and the other half placed in darkness for 30 min. Chemical-cure composite resin was placed on the outer surfaces of all the roots, which were then stored in water for 24 h. They were serially sliced perpendicular to the bonded interface into 8, 0.6 mm-thick slabs, and then transversely sectioned into beams, approximately 8 x 0.6 x 0.6 mm, for the microtensile bond strength test (muTBS). Data were divided into two (coronal/apical half of post-space) and analysed using three-way anova and Scheffe's test (P < 0.05). Failure modes were observed under an scanning electron microscope (SEM) and statistically analysed. Specimens for observation of the bonded interfaces were prepared in a similar manner as for bond strength testing, cut in half and embedded in epoxy resin. They were then polished to a high gloss, gold sputter coated, and after argon ion etching, observed under an SEM. For both dual-cure composite resins and curing strategies, there were no significant differences in muTBS between the coronal and apical regions (P > 0.05). In addition, both dual-cure composite resins exhibited no significant differences in muTBS irrespective of whether polymerization was chemically or photoinitiated (P > 0.05). Both dual-cure composite resins exhibited good bonding to root canal dentin, which was not dependent upon region or mode of polymerization.

Electron beam irradiation of Matricaria chamomilla L. for microbial decontamination

NASA Astrophysics Data System (ADS)

Nemţanu, Monica R.; Kikuchi, Irene Satiko; de Jesus Andreoli Pinto, Terezinha; Mazilu, Elena; Setnic, Silvia; Bucur, Marcela; Duliu, Octavian G.; Meltzer, Viorica; Pincu, Elena

2008-05-01

Wild chamomile (Matricaria chamomilla L.) is one of the most popular herbal materials with both internal and external use to cure different health disturbances. As a consequence of its origin, chamomile could carry various microbial contaminants which offer different hazards to the final consumer. Reduction of the microbial load to the in force regulation limits represents an important phase in the technological process of vegetal materials, and the electron beam treatment might be an efficient alternative to the classical methods of hygienic quality assurance. The purpose of the study was to analyze the potential application of the electron beam treatment in order to assure the microbial safety of the wild chamomile. Samples of chamomile dry inflorescences were treated in electron beam (e-beam) of 6 MeV mean energy, at room temperature and ambient pressure. Some loss of the chemical compounds with bioactive role could be noticed, but the number of microorganisms decreased as a function on the absorbed dose. Consequently, the microbial quality of studied vegetal material inflorescences was improved by e-beam irradiation.

Design of collimating and rearrangement systems of laser diode array beam

NASA Astrophysics Data System (ADS)

Gao, Runmei; Fang, Tao; Fu, Rulian; Yao, Jianquan

2015-10-01

To improve the laser diode output beam quality, micro-cylindrical lens and the step-type lens combination are designed. The former is used to collimate beam in fast-axis direction, while the latter plays a role in the slow-axis of splitting and the rearrangement. The micro-column semi-elliptical lens is made with the drops of spherical zoom lensin electric field and with the help of the material properties of light-cured production, which can reduce the reflection of the front surface and total reflection loss of the after. The divergence angle in the fast axis is compressed to roughly the same as that in the slow-axis direction; Stepped lens splits compressed long strip beam in the slow axis, with parallelogram style of level equidistant and rearrange in the fast axis direction. The spot in the slow axis gets smaller and the spot becomes larger in the fast axis. At last divergence angle and the beam spot achieve balanced in the fast axis and slow axis, optical parameters BPP integrates approximate the same, and beam quality can be improved.

Searching for Components of Conceptual Ecology That Mediate Development of Epistemological Beliefs in Science

NASA Astrophysics Data System (ADS)

Deniz, Hasan

2011-12-01

This paper articulates the importance of epistemological beliefs (EBs) and draws a parallel between EBs literature in educational psychology and nature of science (NOS) literature in science education. The paper stresses that EBs in science and NOS ideas have common ground and they can be best improved through explicit-reflective instruction informed by conceptual change theory. The paper concludes that future studies should explore the factors that mediate the development of EBs in science and NOS ideas rather than documenting the changes in students' and teachers' EBs in science and NOS ideas after explicit-reflective instruction through pre- and post assessments.

Studies of interaction of emodin and DNA in the presence of ethidium bromide by spectroscopic method

NASA Astrophysics Data System (ADS)

Bi, Shuyun; Zhang, Hanqi; Qiao, Chunyu; Sun, Ying; Liu, Chunming

2008-01-01

Emodin interacting with deoxyribonucleic acid (DNA) has been studied by different spectroscopic techniques, such as fluorescence, ultraviolet and visible (UV-vis), and fourier transform infared (FT-IR) spectroscopies, using ethidium bromide (EB) as a fluorescence probe of DNA. The decrease in the fluorescence of DNA-EB system on addition of emodin shows that the fluorescence quenching of DNA-EB complex by emodin occurs. The binding constants of emodin with DNA in the presence of EB are 6.02 × 10 4, 9.20 × 10 4 and 1.17 × 10 5 L mol -1 at 20, 35 and 50 °C, respectively. FT-IR spectrum further suggests that both the phosphate groups and the bases of DNA react with emodin. The reaction of DNA with emodin in the presence of EB is affected by ionic strength and temperature. The values of melting temperature ( Tm) of DNA-EB complex and emodin-DNA-EB complexes were determined, respectively. From the experiment evidences, the major binding mode of emodin with DNA should be the groove binding.

Engineered Barrier System performance requirements systems study report. Revision 02

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

Balady, M.A.

This study evaluates the current design concept for the Engineered Barrier System (EBS), in concert with the current understanding of the geologic setting to assess whether enhancements to the required performance of the EBS are necessary. The performance assessment calculations are performed by coupling the EBS with the geologic setting based on the models (some of which were updated for this study) and assumptions used for the 1995 Total System Performance Assessment (TSPA). The need for enhancements is determined by comparing the performance assessment results against the EBS related performance requirements. Subsystem quantitative performance requirements related to the EBS includemore » the requirement to allow no more than 1% of the waste packages (WPs) to fail before 1,000 years after permanent closure of the repository, as well as a requirement to control the release rate of radionuclides from the EBS. The EBS performance enhancements considered included additional engineered components as well as evaluating additional performance available from existing design features but for which no performance credit is currently being taken.« less

ROCK inhibitor is not required for embryoid body formation from singularized human embryonic stem cells.

PubMed

Pettinato, Giuseppe; Vanden Berg-Foels, Wendy S; Zhang, Ning; Wen, Xuejun

2014-01-01

We report a technology to form human embryoid bodies (hEBs) from singularized human embryonic stem cells (hESCs) without the use of the p160 rho-associated coiled-coil kinase inhibitor (ROCKi) or centrifugation (spin). hEB formation was tested under four conditions: +ROCKi/+spin, +ROCKi/-spin, -ROCKi/+spin, and -ROCKi/-spin. Cell suspensions of BG01V/hOG and H9 hESC lines were pipetted into non-adherent hydrogel substrates containing defined microwell arrays. hEBs of consistent size and spherical geometry can be formed in each of the four conditions, including the -ROCKi/-spin condition. The hEBs formed under the -ROCKi/-spin condition differentiated to develop the three embryonic germ layers and tissues derived from each of the germ layers. This simplified hEB production technique offers homogeneity in hEB size and shape to support synchronous differentiation, elimination of the ROCKi xeno-factor and rate-limiting centrifugation treatment, and low-cost scalability, which will directly support automated, large-scale production of hEBs and hESC-derived cells needed for clinical, research, or therapeutic applications.

The laminar organization of the Drosophila ellipsoid body is semaphorin-dependent and prevents the formation of ectopic synaptic connections

PubMed Central

Xie, Xiaojun; Tabuchi, Masashi; Brown, Matthew P; Mitchell, Sarah P; Wu, Mark N; Kolodkin, Alex L

2017-01-01

The ellipsoid body (EB) in the Drosophila brain is a central complex (CX) substructure that harbors circumferentially laminated ring (R) neuron axons and mediates multifaceted sensory integration and motor coordination functions. However, what regulates R axon lamination and how lamination affects R neuron function remain unknown. We show here that the EB is sequentially innervated by small-field and large-field neurons and that early developing EB neurons play an important regulatory role in EB laminae formation. The transmembrane proteins semaphorin-1a (Sema-1a) and plexin A function together to regulate R axon lamination. R neurons recruit both GABA and GABA-A receptors to their axon terminals in the EB, and optogenetic stimulation coupled with electrophysiological recordings show that Sema-1a-dependent R axon lamination is required for preventing the spread of synaptic inhibition between adjacent EB lamina. These results provide direct evidence that EB lamination is critical for local pre-synaptic inhibitory circuit organization. DOI: http://dx.doi.org/10.7554/eLife.25328.001 PMID:28632130

A novel single walled carbon nanotube (SWCNT) functionalization agent facilitating in vivo combined chemo/thermo therapy

NASA Astrophysics Data System (ADS)

Zhang, Liwen; Rong, Pengfei; Chen, Minglong; Gao, Shi; Zhu, Lei

2015-10-01

Carbon nanotubes (CNTs) have shown intriguing applications in biotechnological and biomedical fields due to their unique shape and properties. However, the fact that unmodified CNTs are prone to aggregation, stunts CNTs applications under physiological conditions. In this research, we found that as little as 1/5th the single walled carbon nanotube (SWCNT) weight of Evans Blue (EB) is capable of dispersing SWCNT as well as facilitating SWCNT functionalization. In view of the binding between EB and albumin, the yielding product (SWCNT/EB) demonstrated extreme stability for weeks under physiological conditions and it can be endowed with a therapeutic ability by simply mixing SWCNT/EB with an albumin based drug. Specifically, the formed SWCNT/EB/albumin/PTX nanocomplex exhibits strong near-infrared (NIR) absorbance, and can serve as an agent for chemo/thermal therapeutic purposes. Our in vivo result reveals that SWCNT/EB/albumin/PTX after being administered into the MDA-MB-435 tumor would effectively ablate the tumor by chemo and photothermal therapy. Such a combined treatment strategy provides remarkable therapeutic outcomes in restraining tumor growth compared to chemo or photothermal therapy alone. Overall, our strategy of dispersing SWCNTs by EB can be used as a platform for carrying other drugs or functional genes with the aid of albumin to treat diseases. The present study opens new opportunities in surface modification of SWCNTs for future clinical disease treatment.Carbon nanotubes (CNTs) have shown intriguing applications in biotechnological and biomedical fields due to their unique shape and properties. However, the fact that unmodified CNTs are prone to aggregation, stunts CNTs applications under physiological conditions. In this research, we found that as little as 1/5th the single walled carbon nanotube (SWCNT) weight of Evans Blue (EB) is capable of dispersing SWCNT as well as facilitating SWCNT functionalization. In view of the binding between EB and albumin, the yielding product (SWCNT/EB) demonstrated extreme stability for weeks under physiological conditions and it can be endowed with a therapeutic ability by simply mixing SWCNT/EB with an albumin based drug. Specifically, the formed SWCNT/EB/albumin/PTX nanocomplex exhibits strong near-infrared (NIR) absorbance, and can serve as an agent for chemo/thermal therapeutic purposes. Our in vivo result reveals that SWCNT/EB/albumin/PTX after being administered into the MDA-MB-435 tumor would effectively ablate the tumor by chemo and photothermal therapy. Such a combined treatment strategy provides remarkable therapeutic outcomes in restraining tumor growth compared to chemo or photothermal therapy alone. Overall, our strategy of dispersing SWCNTs by EB can be used as a platform for carrying other drugs or functional genes with the aid of albumin to treat diseases. The present study opens new opportunities in surface modification of SWCNTs for future clinical disease treatment. Electronic supplementary information (ESI) available: Characterization of EB dispersed SWCNT; chemical structures of dyes applied for SWCNT dispersion; spectrum of EB/albumin; PTX loading efficiency onto albumin at different ratios. See DOI: 10.1039/c5nr03752b

Manufacturing and testing of active composite panels with embedded piezoelectric sensors and actuators: wires out by molded-in holes

NASA Astrophysics Data System (ADS)

Ghasemi-Nejhad, Mehrdad N.; Pourjalali, Saeid

2003-08-01

This work presents manufacturing and testing of active composite panels (ACPs) with embedded piezoelectric sensors and actuators. The composite material employed here is a plain weave carbon epoxy prepreg fabric with about 0.33 mm ply thickness. The piezoelectric patches employed here are Continuum Control Corporation, CCC, (recently Continuum Photonics, Inc) active fiber composite patches with 0.33 mm thickness, i.e. close to the composite ply thickness. Composite cut-out layers are used to fill the space around the embedded piezoelectric patches to minimize the problems associated with ply drops in composites. The piezoelectric patches were embedded inside the composite laminate. High-temperature wires were soldered to the piezoelectric leads, insulated from the carbon substructure by high-temperature materials, and were taken out of the composite laminates employing a molded-in hole technique that reduces the stress concentration as opposed to a drilled hole, and thereby enhancing the performance of the composite structure. The laminated ACP"s were co-cured inside an autoclave employing the cure cycle recommended by the composite material supplier. The curie temperature of the embedded piezoelectric patches should be well above the curing temperature of the composite materials as was the case here. The manufactured ACP beams and plates were trimmed and then tested for their functionality. Vibration suppression as well as simultaneous vibration suppression and precision positioning tests, using PID control as well as Hybrid Adaptive Control techniques were successfully conducted on the manufactured ACP beams and their functionality were demonstrated. Recommendations on the use of this embedding technique for ACPs are provided.

Composite Structures and Materials Research at NASA Langley Research Center

NASA Technical Reports Server (NTRS)

Starnes, James H., Jr.; Dexter, H. Benson; Johnston, Norman J.; Ambur, Damodar R.; Cano, roberto J.

2003-01-01

A summary of recent composite structures and materials research at NASA Langley Research Center is presented. Fabrication research to develop low-cost automated robotic fabrication procedures for thermosetting and thermoplastic composite materials, and low-cost liquid molding processes for preformed textile materials is described. Robotic fabrication procedures discussed include ply-by-ply, cure-on-the-fly heated placement head and out-of-autoclave electron-beam cure methods for tow and tape thermosetting and thermoplastic materials. Liquid molding fabrication processes described include Resin Film Infusion (RFI), Resin Transfer Molding (RTM) and Vacuum-Assisted Resin Transfer Molding (VARTM). Results for a full-scale composite wing box are summarized to identify the performance of materials and structures fabricated with these low-cost fabrication methods.

Composite Structures and Materials Research at NASA Langley Research Center

NASA Technical Reports Server (NTRS)

Starnes, James H., Jr.; Dexter, H. Benson; Johnston, Norman J.; Ambur, Damodar R.; Cano, Roberto J.

2001-01-01

A summary of recent composite structures and materials research at NASA Langley Research Center is presented. Fabrication research to develop low-cost automated robotic fabrication procedures for thermosetting and thermoplastic composite materials, and low-cost liquid molding processes for preformed textile materials is described. Robotic fabrication procedures discussed include ply-by-ply, cure-on-the-fly heated placement head and out-of-autoclave electron-beam cure methods for tow and tape thermosetting and thermoplastic materials. Liquid molding fabrication processes described include Resin Film Infusion (RFI) Resin Transfer Molding (RTM) and Vacuum-Assisted Resin Transfer Molding (VARTM). Results for a full-scale composite wing box are summarized to identify the performance of materials and structures fabricated with these low-cost fabrication methods.

Identification and characterization of OsEBS, a gene involved in enhanced plant biomass and spikelet number in rice.

PubMed

Dong, Xianxin; Wang, Xiaoyan; Zhang, Liangsheng; Yang, Zhengting; Xin, Xiaoyun; Wu, Shuang; Sun, Chuanqing; Liu, Jianxiang; Yang, Jinshui; Luo, Xiaojin

2013-12-01

Common wild rice (Oryza rufipogon Griff.) is an important genetic reservoir for rice improvement. We investigated a quantitative trait locus (QTL), qGP5-1, which is related to plant height, leaf size and panicle architecture, using a set of introgression lines of O. rufipogon in the background of the Indica cultivar Guichao2 (Oryza sativa L.). We cloned and characterized qGP5-1 and confirmed that the newly identified gene OsEBS (enhancing biomass and spikelet number) increased plant height, leaf size and spikelet number per panicle, leading to an increase in total grain yield per plant. Our results showed that the increased size of vegetative organs in OsEBS-expressed plants was enormously caused by increasing cell number. Sequence alignment showed that OsEBS protein contains a region with high similarity to the N-terminal conserved ATPase domain of Hsp70, but it lacks the C-terminal regions of the peptide-binding domain and the C-terminal lid. More results indicated that OsEBS gene did not have typical characteristics of Hsp70 in this study. Furthermore, Arabidopsis (Arabidopsis thaliana) transformed with OsEBS showed a similar phenotype to OsEBS-transgenic rice, indicating a conserved function of OsEBS among plant species. Together, we report the cloning and characterization of OsEBS, a new QTL that controls rice biomass and spikelet number, through map-based cloning, and it may have utility in improving grain yield in rice. © 2013 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Current Status of Early Blight Resistance in Tomato: An Update

PubMed Central

Adhikari, Pragya; Oh, Yeonyee; Panthee, Dilip R.

2017-01-01

Early blight (EB) is one of the dreadful diseases of tomato caused by several species of Alternaria including Alternaria linariae (which includes A. solani and A. tomatophila), as well as A. alternata. In some instances, annual economic yield losses due to EB have been estimated at 79%. Alternaria are known only to reproduce asexually, but a highly-virulent isolate has the potential to overcome existing resistance genes. Currently, cultural practices and fungicide applications are employed for the management of EB due to the lack of strong resistant cultivars. Resistance sources have been identified in wild species of tomato; some breeding lines and cultivars with moderate resistance have been developed through conventional breeding methods. Polygenic inheritance of EB resistance, insufficient resistance in cultivated species and the association of EB resistance with undesirable horticultural traits have thwarted the effective breeding of EB resistance in tomato. Several quantitative trait loci (QTL) conferring EB resistance have been detected in the populations derived from different wild species including Solanum habrochaites, Solanum arcanum and S. pimpinellifolium, but none of them could be used in EB resistance breeding due to low individual QTL effects. Pyramiding of those QTLs would provide strong resistance. More research is needed to identify additional sources of useful resistance, to incorporate resistant QTLs into breeding lines through marker-assisted selection (MAS) and to develop resistant cultivars with desirable horticultural traits including high yielding potential and early maturity. This paper will review the current understanding of causal agents of EB of tomato, resistance genetics and breeding, problems associated with breeding and future prospects. PMID:28934121

On-farm estimation of energy balance in dairy cows using only frequent body weight measurements and body condition score.

PubMed

Thorup, V M; Edwards, D; Friggens, N C

2012-04-01

Precise energy balance estimates for individual cows are of great importance to monitor health, reproduction, and feed management. Energy balance is usually calculated as energy input minus output (EB(inout)), requiring measurements of feed intake and energy output sources (milk, maintenance, activity, growth, and pregnancy). Except for milk yield, direct measurements of the other sources are difficult to obtain in practice, and estimates contain considerable error sources, limiting on-farm use. Alternatively, energy balance can be estimated from body reserve changes (EB(body)) using body weight (BW) and body condition score (BCS). Automated weighing systems exist and new technology performing semi-automated body condition scoring has emerged, so frequent automated BW and BCS measurements are feasible. We present a method to derive individual EB(body) estimates from frequently measured BW and BCS and evaluate the performance of the estimated EB(body) against the traditional EB(inout) method. From 76 Danish Holstein and Jersey cows, parity 1 or 2+, on a glycerol-rich or a whole grain-rich total mixed ration, BW was measured automatically at each milking. The BW was corrected for the weight of milk produced and for gutfill. Changes in BW and BCS were used to calculate changes in body protein, body lipid, and EB(body) during the first 150 d in milk. The EB(body) was compared with the traditional EB(inout) by isolating the term within EB(inout) associated with most uncertainty; that is, feed energy content (FEC); FEC=(EB(body)+EMilk+EMaintenance+Eactivity)/dry matter intake, where the energy requirements are for milk produced (EMilk), maintenance (EMaintenance), and activity (EActivity). Estimated FEC agreed well with FEC values derived from tables (the mean estimate was 0.21 MJ of effective energy/kg of dry matter or 2.2% higher than the mean table value). Further, the FEC profile did not suggest systematic bias in EB(body) with stage of lactation. The EB(body) estimated from daily BW, adjusted for milk and meal-related gutfill and combined with frequent BCS, can provide a successful tool. This offers a pragmatic solution to on-farm calculation of energy balance with the perspective of improved precision under commercial conditions. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Influence of Ionizing Radiation on the Mechanical Properties of a Wood-Plastic Composite

NASA Astrophysics Data System (ADS)

Palm, Andrew; Smith, Jennifer; Driscoll, Mark; Smith, Leonard; Larsen, L. Scott

The focus of this study was to examine the potential benefits of irradiating polyethylene (PE)-based wood-plastic composites (WPCs) in order to enhance the mechanical properties of the WPC. The PE-based WPCs were irradiated, post extrusion, at dose levels of 0, 50, 100, 150, 200, and 250 kGy with an electron beam (EB). The irradiated WPCs were then evaluated using a third point bending test (ASTM D4761) along with scanning electron microscopy (SEM). It was found that ultimate strength and modulus of elasticity (MOE) increased with increasing dose level. Examination of the fracture surfaces of polyethylene revealed a distinct difference in failure between irradiated and non-irradiated surfaces.

Creativity: A Cure for the Common Curriculum

ERIC Educational Resources Information Center

Berrett, Dan

2013-01-01

Einstein was blessed with a rare genius. He also understood the intellectual weight of a flight of fancy. He turned over the idea in his mind for a decade before concluding that the light beam next to him would appear to be at rest even though it was traveling at the speed of light. While it may be tempting to focus on Einstein's cognitive…

Photometric analysis of Ellerman bombs .

NASA Astrophysics Data System (ADS)

Berlicki, A.; Heinzel, P.; Avrett, E. H.

Observations of Ellerman bombs (EBs) show them as short-lived, compact, and spatially localized emissions that are well observable in the wings of the Halpha hydrogen line. The Halpha line profiles of EBs are characterized by deep absorption at the line center and enhanced emission in the wings with maximum around ± 1 Å from the line center, fading beyond ± 5 Å. EBs may also be observed in the chromospheric Ca II lines and in the UV as bright points often located within active regions. Previous work suggests that EBs may be considered as micro-flares and may contribute significantly to the heating of the lower chromosphere in newly emerging magnetic flux regions. However, it is still not clear at what height in the solar atmosphere the emission of EBs originates. In our analysis we used observations of EBs obtained in the Halpha line with the Dutch Open Telescope (DOT) and in the UV range with the TRACE 1600 Å channel. These one-hour long simultaneous sequences obtained with high temporal and spatial resolution were used to analyze the relation between the emission in the Halpha line and at 1600 Å. The observations show fast variations of EB emission in both channels. Comparison between the observed emission in Halpha and at 1600 Å and theoretical calculations allowed us to draw conclusions about the vertical structure of EBs.

Akap350 Recruits Eb1 to The Spindle Poles, Ensuring Proper Spindle Orientation and Lumen Formation in 3d Epithelial Cell Cultures.

PubMed

Almada, Evangelina; Tonucci, Facundo M; Hidalgo, Florencia; Ferretti, Anabela; Ibarra, Solange; Pariani, Alejandro; Vena, Rodrigo; Favre, Cristián; Girardini, Javier; Kierbel, Arlinet; Larocca, M Cecilia

2017-11-02

The organization of epithelial cells to form hollow organs with a single lumen requires the accurate three-dimensional arrangement of cell divisions. Mitotic spindle orientation is defined by signaling pathways that provide molecular links between specific spots at the cell cortex and astral microtubules, which have not been fully elucidated. AKAP350 is a centrosomal/Golgi scaffold protein, implicated in the regulation of microtubule dynamics. Using 3D epithelial cell cultures, we found that cells with decreased AKAP350 expression (AKAP350KD) formed polarized cysts with abnormal lumen morphology. Analysis of mitotic cells in AKAP350KD cysts indicated defective spindle alignment. We established that AKAP350 interacts with EB1, a microtubule associated protein that regulates spindle orientation, at the spindle poles. Decrease of AKAP350 expression lead to a significant reduction of EB1 levels at spindle poles and astral microtubules. Conversely, overexpression of EB1 rescued the defective spindle orientation induced by deficient AKAP350 expression. The specific delocalization of the AKAP350/EB1complex from the centrosome decreased EB1 levels at astral microtubules and lead to the formation of 3D-organotypic structures which resembled AKAP350KD cysts. We conclude that AKAP350 recruits EB1 to the spindle poles, ensuring EB1 presence at astral microtubules and proper spindle orientation during epithelial morphogenesis.

Method for Fabricating Composite Structures Using Pultrusion Processing

NASA Technical Reports Server (NTRS)

Farley, Gary L. (Inventor)

2000-01-01

A method for fabricating composite structures at a low-cost, moderate-to-high production rate. A first embodiment of the method includes employing a continuous press forming fabrication process. A second embodiment of the method includes employing a pultrusion process for obtaining composite structures. The methods include coating yarns with matrix material, weaving the yarn into fabric to produce a continuous fabric supply and feeding multiple layers of net-shaped fabrics having optimally oriented fibers into a debulking tool to form an undebulked preform. The continuous press forming fabrication process includes partially debulking the preform, cutting the partially debulked preform and debulking the partially debulked preform to form a net-shape. An electron-beam or similar technique then cures the structure. The pultrusion fabric process includes feeding the undebulked preform into a heated die and gradually debulking the undebulked preform. The undebulked preform in the heated die changes dimension until a desired cross-sectional dimension is achieved. This process further includes obtaining a net-shaped infiltrated uncured preform, cutting the uncured preform to a desired length and electron-beam curing (or similar technique) the uncured preform. These fabrication methods produce superior structures formed at higher production rates, resulting in lower cost and high structural performance.

Method for Fabricating Composite Structures Using Continuous Press Forming

NASA Technical Reports Server (NTRS)

Farley, Gary L. (Inventor)

1997-01-01

A method for fabricating composite structures at a low-cost. moderate-to-high production rate. A first embodiment of the method includes employing a continuous press forming fabrication process. A second embodiment of the method includes employing a pultrusion process for obtaining composite structures. The methods include coating yarns with matrix material, weaving the yarn into fabric to produce a continuous fabric supply and feeding multiple layers of net-shaped fabrics having optimally oriented fibers into a debulking tool to form an undebulked preform. The continuous press forming fabrication process includes partially debulking the preform, cutting the partially debulked preform and debulking the partially debulked preform to form a net-shape. An electron-beam or similar technique then cures the structure. The pultrusion fabric process includes feeding the undebulked preform into a heated die and gradually debulking the undebulked preform. The undebulked preform in the heated die changes dimension until a desired cross-sectional dimension is achieved. This process further includes obtaining a net-shaped infiltrated uncured preform, cutting the uncured preform to a desired length and electron-beam curing (or similar technique) the uncured preform. These fabrication methods produce superior structures formed at higher production rates. resulting in lower cost and high structural performance.

Real-time synchronous measurement of curing characteristics and polymerization stress in bone cements with a cantilever-beam based instrument

NASA Astrophysics Data System (ADS)

Palagummi, Sri Vikram; Landis, Forrest A.; Chiang, Martin Y. M.

2018-03-01

An instrumentation capable of simultaneously determining degree of conversion (DC), polymerization stress (PS), and polymerization exotherm (PE) in real time was introduced to self-curing bone cements. This comprises the combination of an in situ high-speed near-infrared spectrometer, a cantilever-beam instrument with compliance-variable feature, and a microprobe thermocouple. Two polymethylmethacrylate-based commercial bone cements, containing essentially the same raw materials but differ in their viscosity for orthopedic applications, were used to demonstrate the applicability of the instrumentation. The results show that for both the cements studied the final DC was marginally different, the final PS was different at the low compliance, the peak of the PE was similar, and their polymerization rates were significantly different. Systematic variation of instrumental compliance for testing reveals differences in the characteristics of PS profiles of both the cements. This emphasizes the importance of instrumental compliance in obtaining an accurate understanding of PS evaluation. Finally, the key advantage for the simultaneous measurements is that these polymerization properties can be correlated directly, thus providing higher measurement confidence and enables a more in-depth understanding of the network formation process.

A review of scoring systems for ocular involvement in chronic cutaneous bullous diseases.

PubMed

Lee, Brendon W H; Tan, Jeremy C K; Radjenovic, Melissa; Coroneo, Minas T; Murrell, Dedee F

2018-05-22

Epidermolysis bullosa (EB) and autoimmune blistering diseases (AIBD) describe a group of rare chronic dermatoses characterized by cutaneous fragility and blistering. Although uncommon, significant ocular surface disease (OSD) may occur in both and require ophthalmological assessment. Disease scoring systems have a critical role in providing objective and accurate assessment of disease severity. The objectives of this report were, firstly, to document the prevalence and severity of ocular involvement in EB/AIBD. Secondly, to review and evaluate existing ocular and systemic scoring systems for EB/AIBD. Finally, to identify areas where further development of ocular specific tools in EB/AIBD could be pursued. A literature search was performed in October 2017 utilising Medline, Embase, and Scopus databases. The results were restricted by date of publication, between 01.01.1950 and 31.10.2017. The reference lists of these articles were then reviewed for additional relevant publications. Articles of all languages were included if an English translation was available. Articles were excluded if they were duplicates, had no reference to ocular involvement in EB/AIBD or described ocular involvement in other diseases. Descriptions of ocular involvement in EB/AIBD were identified in 88 peer-reviewed journal articles. Findings reported include but are not limited to: cicatrising conjunctivitis, meibomian gland dysfunction, dry eye disease, trichiasis, symblepharon, fornix fibrosis, keratopathy, ectropion/entropion, ankyloblepharon, corneal ulceration, visual impairment and blindness. Although scoring systems exist for assessment of OSD in mucous membrane pemphigoid, no such tools exist for the other AIBD subtypes or for EB. Several systemic scoring systems exist in the dermatological literature that are efficacious in grading overall EB/AIBD severity, but have limited inclusion of ocular features. To the best of our knowledge, there is no recognised or validated scoring systems which comprehensively stages or grades the spectrum of ocular manifestations in EB/AIBD. There are a range of ocular complications documented in EB and AIBD. Development of a comprehensive ocular scoring system for EB/AIBD which incorporates the delineation between 'activity' and 'damage' would facilitate more objective patient assessment, improved longitudinal monitoring, comparison of intervention outcomes, and provide commonality for discussion of these patients due to the multidisciplinary nature of their care.

47 CFR 27.1203 - EBS programming requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 2 2011-10-01 2011-10-01 false EBS programming requirements. 27.1203 Section 27.1203 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES....1203 EBS programming requirements. (a) Except as provided in paragraphs (b), (c), and (d) of this...

Fabrication and characterization of aerosol-jet printed strain sensors for multifunctional composite structures

NASA Astrophysics Data System (ADS)

Zhao, Da; Liu, Tao; Zhang, Mei; Liang, Richard; Wang, Ben

2012-11-01

Traditional multifunctional composite structures are produced by embedding parasitic parts, such as foil sensors, optical fibers and bulky connectors. As a result, the mechanical properties of the composites, especially the interlaminar shear strength (ILSS), could be largely undermined. In the present study, we demonstrated an innovative aerosol-jet printing technology for printing electronics inside composite structures without degrading the mechanical properties. Using the maskless fine feature deposition (below 10 μm) characteristics of this printing technology and a pre-cure protocol, strain sensors were successfully printed onto carbon fiber prepregs to enable fabricating composites with intrinsic sensing capabilities. The degree of pre-cure of the carbon fiber prepreg on which strain sensors were printed was demonstrated to be critical. Without pre-curing, the printed strain sensors were unable to remain intact due to the resin flow during curing. The resin flow-induced sensor deformation can be overcome by introducing 10% degree of cure of the prepreg. In this condition, the fabricated composites with printed strain sensors showed almost no mechanical degradation (short beam shearing ILSS) as compared to the control samples. Also, the failure modes examined by optical microscopy showed no difference. The resistance change of the printed strain sensors in the composite structures were measured under a cyclic loading and proved to be a reliable mean strain gauge factor of 2.2 ± 0.06, which is comparable to commercial foil metal strain gauge.

Shewanella canadensis sp. nov. and Shewanella atlantica sp. nov., manganese dioxide- and hexahydro-1,3,5-trinitro-1,3,5-triazine-reducing, psychrophilic marine bacteria.

PubMed

Zhao, Jian-Shen; Manno, Dominic; Thiboutot, Sonia; Ampleman, Guy; Hawari, Jalal

2007-09-01

Two strains belonging to the genus Shewanella, HAW-EB2(T) and HAW-EB5(T), were isolated previously from marine sediment sampled from the Atlantic Ocean, near Halifax harbour in Canada, for their potential to degrade explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). In the present study, strains HAW-EB2(T) and HAW-EB5(T) were found to display high 16S rRNA gene sequence similarity (90-99.5 %) to species of Shewanella, but their gyrB sequences were significantly different from each other and from species of Shewanella (79-87.6 %). Furthermore, DNA-DNA hybridization showed that the genomic DNA of the two strains was only 22 % related and showed less than 41 % relatedness to closely related species of Shewanella. In comparison to other species of Shewanella, strains HAW-EB2(T) and HAW-EB5(T) were also unique in some phenotypic properties such as activities of beta-galactosidase and tyrosine arylamidase and the ability to metabolize certain organic acids and sugars. Both strains HAW-EB2(T) and HAW-EB5(T) utilize malate, valerate, peptone and yeast extract as sole carbon and energy sources. The major membrane fatty acids of the two strains were C(14 : 0), iso-C(15 : 0), C(16 : 0), C(16 : 1)omega7, C(18 : 1)omega7 and C(20 : 5)omega3 and their major quinones were Q-7, Q-8 and MK-7. On the basis of these results, strain HAW-EB2(T) (=NCIMB 14238(T) =CCUG 54553(T)) is proposed as the type strain of Shewanella canadensis sp. nov. and strain HAW-EB5(T) (=NCIMB 14239(T) =CCUG 54554(T)) is proposed as the type strain of Shewanella atlantica sp. nov.

Quantitation of DNA Adducts Induced by 1,3-Butadiene

NASA Astrophysics Data System (ADS)

Sangaraju, Dewakar; Villalta, Peter W.; Wickramaratne, Susith; Swenberg, James; Tretyakova, Natalia

2014-07-01

Human exposure to 1,3-butadiene (BD) present in automobile exhaust, cigarette smoke, and forest fires is of great concern because of its potent carcinogenicity. The adverse health effects of BD are mediated by its epoxide metabolites such as 3,4-epoxy-1-butene (EB), which covalently modify genomic DNA to form promutagenic nucleobase adducts. Because of their direct role in cancer, BD-DNA adducts can be used as mechanism-based biomarkers of BD exposure. In the present work, a mass spectrometry-based methodology was developed for accurate, sensitive, and precise quantification of EB-induced N-7-(1-hydroxy-3-buten-2-yl) guanine (EB-GII) DNA adducts in vivo. In our approach, EB-GII adducts are selectively released from DNA backbone by neutral thermal hydrolysis, followed by ultrafiltration, offline HPLC purification, and isotope dilution nanoLC/ESI+-HRMS3 analysis on an Orbitrap Velos mass spectrometer. Following method validation, EB-GII lesions were quantified in human fibrosarcoma (HT1080) cells treated with micromolar concentrations of EB and in liver tissues of rats exposed to sub-ppm concentrations of BD (0.5-1.5 ppm). EB-GII concentrations increased linearly from 1.15 ± 0.23 to 10.11 ± 0.45 adducts per 106 nucleotides in HT1080 cells treated with 0.5-10 μM DEB. EB-GII concentrations in DNA of laboratory rats exposed to 0.5, 1.0, and 1.5 ppm BD were 0.17 ± 0.05, 0.33 ± 0.08, and 0.50 ± 0.04 adducts per 106 nucleotides, respectively. We also used the new method to determine the in vivo half-life of EB-GII adducts in rat liver DNA (2.20 ± 0.12 d) and to detect EB-GII in human blood DNA. To our knowledge, this is the first application of nanoLC/ESI+-HRMS3 Orbitrap methodology to quantitative analysis of DNA adducts in vivo.

Observation of Instabilities of Coherent Transverse Ocillations in the Fermilab Booster

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

Alexahin, Y.; Eddy, N.; Gianfelice-Wendt, E.

2012-05-01

The Fermilab Booster - built more than 40 years ago - operates well above the design proton beam intensity of 4 {center_dot} 10{sup 12} ppp. Still, the Fermilab neutrino experiments call for even higher intensity exceeding 5.5 {center_dot} 10{sup 12} ppp. A multitude of intensity related effects must be overcome in order to meet this goal including suppression of coherent dipole instabilities of transverse oscillations which manifest themselves as a sudden drop in the beam current. In this report we present the results of observation of these instabilities at different tune, coupling and chromaticity settings and discuss possible cures.

Measurement of solubility and water sorption of dental nanocomposites light cured by argon laser.

PubMed

Mirsasaani, Seyed Shahabeddin; Ghomi, Farhad; Hemati, Mehran; Tavasoli, Tina

2013-03-01

Different parameters used for photoactivation process and also composition provide changes in the properties of dental composites. In the present work the effect of different power density of argon laser and filler loading on solubility (SL) and water sorption (WS) of light-cure dental nanocomposites was studied. The resin of nanocomposites was prepared by mixing bisphenol A glycol dimethacrylate (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) with a mass ratio of 65/35. 20 wt.% and 25 wt.% of nanosilica fillers with a primary particle size of 10 nm were added to the resin. Camphorquinone (CQ) and DMAEMA were added as photoinitiator system. The nanocomposites were cured by applying the laser beam at the wavelength of 472 nm and power densities of 260 and 340 mW/cm(2) for 40 sec. Solubility and water sorption were then measured according to ISO 4049, which in our case, the maximums were 2.2% and 4.3% at 260 mW/cm(2) and 20% filler, respectively. The minimum solubility (1.2%) and water sorption (3.8%) were achieved for the composite containing 25% filler cured at 340 mW/cm(2). The results confirmed that higher power density and filler loading decreased solubility of unreacted monomers and water sorption and improved physico-mechanical properties of nanocomposites.

Application of a non-hazardous vital dye for cell counting with automated cell counters.

PubMed

Kim, Soo In; Kim, Hyun Jeong; Lee, Ho-Jae; Lee, Kiwon; Hong, Dongpyo; Lim, Hyunchang; Cho, Keunchang; Jung, Neoncheol; Yi, Yong Weon

2016-01-01

Recent advances in automated cell counters enable us to count cells more easily with consistency. However, the wide use of the traditional vital dye trypan blue (TB) raises environmental and health concerns due to its potential teratogenic effects. To avoid this chemical hazard, it is of importance to introduce an alternative non-hazardous vital dye that is compatible with automated cell counters. Erythrosin B (EB) is a vital dye that is impermeable to biological membranes and is used as a food additive. Similarly to TB, EB stains only nonviable cells with disintegrated membranes. However, EB is less popular than TB and is seldom used with automated cell counters. We found that cell counting accuracy with EB was comparable to that with TB. EB was found to be an effective dye for accurate counting of cells with different viabilities across three different automated cell counters. In contrast to TB, EB was less toxic to cultured HL-60 cells during the cell counting process. These results indicate that replacing TB with EB for use with automated cell counters will significantly reduce the hazardous risk while producing comparable results. Copyright © 2015 Logos Biosystems, Inc. Published by Elsevier Inc. All rights reserved.

Restrictions in oral functions caused by oral manifestations of epidermolysis bullosa.

PubMed

Stellingsma, Cornelis; Dijkstra, Pieter U; Dijkstra, Janke; Duipmans, José C; Jonkman, Marcel F; Dekker, Rienk

2011-01-01

Several forms of epidermolysis bullosa (EB) present oral manifestations. Blistering of the (peri)oral mucosa affects the opening of the mouth, the mobility of the tongue and lips, thereby restricting oral functions. We describe the prevalence and characteristics of oral manifestations of EB in relation to loss of oral functions in a cross-sectional study of different types of EB patients using standardized measurement techniques. Twenty-two patients were included. The mobility of the mandible, lips and tongue was measured, the mandibular function impairment questionnaire (MFIQ) was filled out and additional questions regarding hindrance of EB during oral hygiene and intelligibility of speech (being understood) were asked in structured interviews. The median age was 11.8 yrs. Mobility of the mandible, tongue and lip was restricted, oral hygiene procedures were hindered in most patients. A data comparison was made between the recessive dystrophic EB (RDEB) and junctional EB (JEB) groups. Mandibular function was impaired in both groups but more severely in the RDEB-population. Intelligibility in both groups was almost unaffected. Restrictions in mobility of the mouth, tongue and lips are frequently present in EB patients. These are most severe in the RDEB group and support the clinical relevance of optimizing symptomatic treatment.

Induction of cytoplasmic petite in yeast by guanidine hydrochloride: combined treatment with other inducing agents.

PubMed

Villa, L L; Juliani, M H

1980-06-01

We have studied the induction of rho- mutants by guanidine hydrochloride (GuHCl) in combination with other known inducers: ethidium bromide (EB), berenil and ultraviolet light. Competition was observed when cells were simultaneously treated with optimal concentrations of EB and GuHCl; on the other hand, treatment of cells with EB in the presence of non-inducing concentrations of GuHCl resulted in the stimulation of rho- induction of EB. Furthermore, using a strain which upon treatment with high EB concentrations shows recovery of respiratory competence, the presence of GuHCl did not interfere either with the early phase of induction or with the recovery phase, but it did interfere in a competitive fashion with the final irreversible phase of EB induction. In the case of berenil, a synergistic effect was seen when cells were pretreated with GuHCl. A synergistic induction was also observed when cells were submitted to UV prior to GuHCl treatment. These results suggest that GuHCl, EB and berenil act via some common step in their rho- induction pathways. Moreover, GuHCl may somehow be decreasing the efficiency of dark repair of ultraviolet lesions on mitochondrial DNA.

PDSM characterization for fabrication of free-space OXC optical components

NASA Astrophysics Data System (ADS)

Argueta, Victor; Fitzpatrick, Brianna

2017-11-01

In 2007 Dr Khine et al published a paper where they presented a technique using thermoplastics and PDMS to create microfluidic patterns1. Their technique involves printing a pattern in a polystyrene sheet using a laser printer. Once the pattern is transfer the polystyrene sheets they are heated to reduce their size. By printing the same pattern of the plastic sheets before heating, it is possible to control the height up to 80 μm and the width as thin as 65 μm1, 2. This technique is attractive to be used in optical fabrication due to its versatility, low cost and fast prototyping. However, in order to fabricate optical systems, we will need to control the refractive index of PDMS to allow design of basic optical components like waveguides, beam splitter, or diffuse reflectors; or more complex structures like interferometers, optical microfluidic lab-on-chip, micro-lens arrays. Several techniques exist to control the refractive index for PDMS either by controlling the curing temperature, the ratio between the base and curing agent, or by curing using UV light3-5. In this paper, we present the changes on refractive index by changing the curing temperature for different base/reaction agent ratios. We then apply these results to fabricate an optical component for a free-space optical cross-connect (OXC). Optical cross-connects are an important network element for constructing the next generation of optical networks, where provisioning (reconfiguration), scalability, and fast restoration will be needed6-8. The main attraction of all-optical switching is that it enables routing of optical data signals without the need for conversion to electrical signals, and therefore, is independent of data rate and data protocols. We have proposed previously9, 11 a new approach for an OXC. Our architecture is a free-space 3-D while still using digital MEMS. Our system is based on the optical White cell12, which consists of three spherical mirrors among which light can circulate. In Section II, we will briefly mention the basic characteristics of the binary White cell OXC configuration. Section III we will introduce the changes induced on curing PDMS, our SDD design and its fabrication for two different beam displacements. Finally, in Section IV, we will present the summary and conclusions of our work.

Distinct retroelement classes define evolutionary breakpoints demarcating sites of evolutionary novelty

PubMed Central

Longo, Mark S; Carone, Dawn M; Green, Eric D; O'Neill, Michael J; O'Neill, Rachel J

2009-01-01

Background Large-scale genome rearrangements brought about by chromosome breaks underlie numerous inherited diseases, initiate or promote many cancers and are also associated with karyotype diversification during species evolution. Recent research has shown that these breakpoints are nonrandomly distributed throughout the mammalian genome and many, termed "evolutionary breakpoints" (EB), are specific genomic locations that are "reused" during karyotypic evolution. When the phylogenetic trajectory of orthologous chromosome segments is considered, many of these EB are coincident with ancient centromere activity as well as new centromere formation. While EB have been characterized as repeat-rich regions, it has not been determined whether specific sequences have been retained during evolution that would indicate previous centromere activity or a propensity for new centromere formation. Likewise, the conservation of specific sequence motifs or classes at EBs among divergent mammalian taxa has not been determined. Results To define conserved sequence features of EBs associated with centromere evolution, we performed comparative sequence analysis of more than 4.8 Mb within the tammar wallaby, Macropus eugenii, derived from centromeric regions (CEN), euchromatic regions (EU), and an evolutionary breakpoint (EB) that has undergone convergent breakpoint reuse and past centromere activity in marsupials. We found a dramatic enrichment for long interspersed nucleotide elements (LINE1s) and endogenous retroviruses (ERVs) and a depletion of short interspersed nucleotide elements (SINEs) shared between CEN and EBs. We analyzed the orthologous human EB (14q32.33), known to be associated with translocations in many cancers including multiple myelomas and plasma cell leukemias, and found a conserved distribution of similar repetitive elements. Conclusion Our data indicate that EBs tracked within the class Mammalia harbor sequence features retained since the divergence of marsupials and eutherians that may have predisposed these genomic regions to large-scale chromosomal instability. PMID:19630942

Diversity of Endophytic Bacteria in a Fern Species Dryopteris uniformis (Makino) Makino and Evaluation of Their Antibacterial Potential Against Five Foodborne Pathogenic Bacteria.

PubMed

Das, Gitishree; Park, Seonjoo; Baek, Kwang-Hyun

2017-05-01

The fern plant Dryopteris uniformis has traditionally been used in herbal medicine and possesses many biological activities. This study was conducted to explore the endophytic bacterial diversity associated with D. uniformis and evaluate their antibacterial potential against foodborne pathogenic bacteria (FPB). Among 51 isolated endophytic bacteria (EB), 26 EB were selected based on their morphological characteristics and identified by 16S rRNA gene analysis. The distribution of EB was diverse in the leaf and the stem/root tissues. When the EB were screened for antibacterial activity against five FPB, Listeria monocytogenes, Salmonella Typhimurium, Bacillus cereus, Staphylococcus aureus, and Escherichia coli O157:H7, four EB Bacillus sp. cryopeg, Paenibacillus sp. rif200865, Staphylococcus warneri, and Bacillus psychrodurans had a broad spectrum of antibacterial activity (9.58 ± 0.66 to 21.47 ± 0.27 mm inhibition zone). The butanol solvent extract of B. sp. cryopeg and P. sp. rif200865 displayed effective antibacterial activity against the five FPB, which was evident from the scanning electron microscopy with irregular or burst cell morphology in the EB-treated bacteria compared to smooth and regular cells in case of the control bacteria. The minimum inhibitory concentration and minimum bactericidal concentration values ranged between 250-500 μg/mL and 500-100 μg/mL, respectively. The above outcomes signify the huge prospective of the selected EB in the food industry. Overall, the above results suggested that D. uniformis contains several culturable EB that possess effective antibacterial compounds, and that EB can be utilized as a source of natural antibacterial agents for their practical application in food industry to control the spread of FPB as a natural antibacterial agent.

Producing and marketing a specialty egg.

PubMed

Michella, S M; Slaugh, B T

2000-07-01

Eggland's Best, Inc. markets premium quality shell eggs under the Eggland's Best (EB) brand name. The company, started in 1988, is comprised of a franchise network of established egg producers and covers most of the United States. Eggland's Best provides its franchisees with marketing and technical support. The franchisees produce, process, and distribute EB eggs according to the strict program established and monitored by EB. Production follows the all-natural vegetarian feed program in accordance with the company's US patent entitled "Eggs Compatible with a Cholesterol Reducing Diet and Method of Producing the Same." The EB program excludes animal fat and other animal byproducts. Eggland's Best eggs have seven times the generic level of vitamin E, nearly three times more omega-3 fatty acids and iodine, and 25% less saturated fat than regular generic eggs. Eggland's Best has one of the finest shell egg quality assurance programs anywhere. Eggland's Best franchisees submit weekly egg samples that are analyzed for shell quality, interior quality, vitamin E, iodine, cholesterol and fatty acids. Samples of feed and the EB-patented feed supplement are also analyzed. Approximately 28,000 total laboratory tests are conducted annually. Nationwide product and display retail evaluations are contracted through an outside audit company (40 to 50 cities evaluated four times per year). All EB eggs are USDA graded according to EB's strict quality standards. Producers must follow a food safety quality assurance program (United Egg Producers Association 5-Star or equivalent state or company program). Each egg is stamped "EB" as assurance of meeting EB's highest standards of flavor, quality, and nutrition. Eggland's Best has enjoyed record sales growth for the past 3 yr.

Self-organization phenomena in embryonic stem cell-derived embryoid bodies: axis formation and breaking of symmetry during cardiomyogenesis.

PubMed

Fuchs, Christiane; Scheinast, Matthias; Pasteiner, Waltraud; Lagger, Sabine; Hofner, Manuela; Hoellrigl, Alexandra; Schultheis, Martina; Weitzer, Georg

2012-01-01

Aggregation of embryonic stem cells gives rise to embryoid bodies (EBs) which undergo developmental processes reminiscent of early eutherian embryonic development. Development of the three germ layers suggests that gastrulation takes place. In vivo, gastrulation is a highly ordered process but in EBs only few data support the hypothesis that self-organization of differentiating cells leads to morphology, reminiscent of the early gastrula. Here we demonstrate that a timely implantation-like process is a prerequisite for the breaking of the radial symmetry of suspended EBs. Attached to a surface, EBs develop a bilateral symmetry and presumptive mesodermal cells emerge between the center of the EBs and a horseshoe-shaped ridge of cells. The development of an epithelial sheet of cells on one side of the EBs allows us to define an 'anterior' and a 'posterior' end of the EBs. In the mesodermal area, first cardiomyocytes (CMCs) develop mainly next to this epithelial sheet of cells. Development of twice as many CMCs at the 'left' side of the EBs breaks the bilateral symmetry and suggests that cardiomyogenesis reflects a local or temporal asymmetry in EBs. The asymmetric appearance of CMCs but not the development of mesoderm can be disturbed by ectopic expression of the muscle-specific protein Desmin. Later, the bilateral morphology becomes blurred by an apparently chaotic differentiation of many cell types. The absence of comparable structures in aggregates of cardiovascular progenitor cells isolated from the heart demonstrates that the self-organization of cells during a gastrulation-like process is a unique feature of embryonic stem cells. Copyright © 2011 S. Karger AG, Basel.

Photoacoustic imaging of intravenously injected photosensitizer in rat burn models for efficient antibacterial photodynamic therapy

NASA Astrophysics Data System (ADS)

Tsunoi, Yasuyuki; Sato, Shunichi; Ashida, Hiroshi; Terakawa, Mitsuhiro

2012-02-01

For efficient photodynamic treatment of wound infection, a photosensitizer must be distributed in the whole infected tissue region. To ensure this, depth profiling of a photosensitizer is necessary in vivo. In this study, we applied photoacoustic (PA) imaging to visualize the depth profile of an intravenously injected photosensitizer in rat burn models. In burned tissue, pharmacokinetics is complicated; vascular occlusion takes place in the injured tissue, while vascular permeability increases due to thermal invasion. In this study, we first used Evans Blue (EB) as a test drug to examine the feasibility of photosensitizer dosimetry based on PA imaging. On the basis of the results, an actual photosensitizer, talaporfin sodium was used. An EB solution was intravenously injected into a rat deep dermal burn model. PA imaging was performed on the wound with 532 nm and 610 nm nanosecond light pulses for visualizing vasculatures (blood) and EB, respectively. Two hours after injection, the distribution of EB-originated signal spatially coincided well with that of blood-originated signal measured after injury, indicating that EB molecules leaked out from the blood vessels due to increased permeability. Afterwards, the distribution of EB signal was broadened in the depth direction due to diffusion. At 12 hours after injection, clear EB signals were observed even in the zone of stasis, demonstrating that the leaked EB molecules were delivered to the injured tissue layer. The level and time course of talaporfin sodium-originated signals were different compared with those of EB-originated signals, showing animal-dependent and/or drug-dependent permeabilization and diffusion in the tissue. Thus, photosensitizer dosimetry should be needed before every treatment to achieve desirable outcome of photodynamic treatment, for which PA imaging can be concluded to be valid and useful.

Icariin promotes expression of junctophilin 2 and Ca2+ related function during cardiomyocyte differentiation of murine embryonic stem cells.

PubMed

Liang, Xingguang; Hong, Dongsheng; Huang, Yujie; Rao, Yuefeng; Ma, Kuifen; Huang, Mingzhu; Zhang, Xingguo; Lou, Yijia; Zhao, Qingwei

2015-12-01

Junctophilin2 (JP2) is a critical protein associated with cardiogenesis. Icariin (ICA) facilitated the directional differentiation of murine embryonic stem (ES) cells into cardiomyocytes. However, little is known about the effects of ICA on JP2 during cardiac differentiation. Here, we explored whether ICA has effects on the expression and Ca2+ related function of JP2 during cardiomyocyte differentiation of ES cells in vitro. Embryonid bodies (EBs) formed by hanging drop were treated with 10(-7) mol/L ICA from day 5 to promote the cardiac differentiation. Percentage of beating EBs and number of beating area within EBs were monitored. Cardiomyocytes were purified by discontinuous percoll gradient centrifugation from EBs. The expression of JP2, α-actinin and troponin-T within EBs or isolated cardiomyocytes were analyzed by immunocytochemistry, western blot and flow cytometry. The transient Ca2+ release was characterized in cardiomyocytes treated with/without 10 mmol/L caffeine and 8 mmol/L Ca2+. Our results showed that ES cell-derived cardiomyocytes were well characterized with JP2 proteins. ICA promoted cardiomyocyte differentiation as indicated by an increased percentage of beating EBs and number of beating area within EBs. The expression of JP2, α-actinin and troponin-T were up-regulated both in EBs and isolated cardiomyocytes from EBs. Furthermore, ICA-induced JP2 expression was accompanied by a remarkable increase of the amplitude of Ca2+ transients in cardiomyocytes before/after caffeine and Ca2+ stimulating. In conclusion, ICA promotes in cardiac differentiation partly through regulating JP2 and improved the Ca2+ modulatory function of cardiomyocytes.

Evans blue dye-enhanced capillary-resolution photoacoustic microscopy in vivo

NASA Astrophysics Data System (ADS)

Yao, Junjie; Maslov, Konstantin; Hu, Song; Wang, Lihong V.

2009-09-01

Complete and continuous imaging of microvascular networks is crucial for a wide variety of biomedical applications. Photoacoustic tomography can provide high resolution microvascular imaging using hemoglobin within red blood cells (RBCs) as an endogenic contrast agent. However, intermittent RBC flow in capillaries results in discontinuous and fragmentary capillary images. To overcome this problem, we use Evans blue (EB) dye as a contrast agent for in vivo photoacoustic imaging. EB has strong optical absorption and distributes uniformly in the blood stream by chemically binding to albumin. With the help of EB, complete and continuous microvascular networks--especially capillaries--are imaged. The diffusion dynamics of EB leaving the blood stream and the clearance dynamics of the EB-albumin complex are also quantitatively investigated.

47 CFR 27.58 - Interference to BRS/EBS receivers.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 2 2011-10-01 2011-10-01 false Interference to BRS/EBS receivers. 27.58 Section 27.58 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Technical Standards § 27.58 Interference to BRS/EBS receivers. (a...

PSD-95 alters microtubule dynamics via an association with EB3

PubMed Central

Sweet, Eric S.; Previtera, Michelle L.; Fernández, Jose R.; Charych, Erik I.; Tseng, Chia-Yi; Kwon, Munjin; Starovoytov, Valentin; Zheng, James Q.; Firestein, Bonnie L.

2011-01-01

Little is known about how the neuronal cytoskeleton is regulated when a dendrite decides whether to branch or not. Previously, we reported that postsynaptic density protein 95 (PSD-95) acts as a stop signal for dendrite branching. It is yet to be elucidated how PSD-95 affects the cytoskeleton and how this regulation relates to the dendritic arbor. Here, we show that the SH3 (src homology 3) domain of PSD-95 interacts with a proline-rich region within the microtubule end-binding protein EB3. Overexpression of PSD-95 or mutant EB3 results in a decreased lifetime of EB3 comets in dendrites. In line with these data, transfected rat neurons show that overexpression of PSD-95 results in less organized microtubules at dendritic branch points and decreased dendritogensis. The interaction between PSD-95 and EB3 elucidates a function for a novel region of EB3 and provides a new and important mechanism for the regulation of microtubules in determining dendritic morphology. PMID:21248129

Evaluation of substituted ebselen derivatives as potential trypanocidal agents.

PubMed

Gordhan, Heeren M; Patrick, Stephen L; Swasy, Maria I; Hackler, Amber L; Anayee, Mark; Golden, Jennifer E; Morris, James C; Whitehead, Daniel C

2017-02-01

Human African trypanosomiasis is a disease of sub-Saharan Africa, where millions are at risk for the illness. The disease, commonly referred to as African sleeping sickness, is caused by an infection by the eukaryotic pathogen, Trypanosoma brucei. Previously, a target-based high throughput screen revealed ebselen (EbSe), and its sulfur analog, EbS, to be potent in vitro inhibitors of the T. brucei hexokinase 1 (TbHK1). These molecules also exhibited potent trypanocidal activity in vivo. In this manuscript, we synthesized a series of sixteen EbSe and EbS derivatives bearing electron-withdrawing carboxylic acid and methyl ester functional groups, and evaluated the influence of these substituents on the biological efficacy of the parent scaffold. With the exception of one methyl ester derivative, these modifications ablated or blunted the potent TbHK1 inhibition of the parent scaffold. Nonetheless, a few of the methyl ester derivatives still exhibited trypanocidal effects with single-digit micromolar or high nanomolar EC 50 values. Copyright © 2016 Elsevier Ltd. All rights reserved.

Photoacoustic microscopy using Evans Blue dye as a contrast agent

NASA Astrophysics Data System (ADS)

Yao, Junjie; Maslov, Konstantin I.; Hu, Song; Wang, Lihong V.

2010-02-01

Complete and continuous imaging of microvascular networks is crucial for a wide variety of biomedical applications. Photoacoustic tomography can provide high resolution microvascular imaging using hemoglobin within red blood cells (RBC) as an endogenous contrast agent. However, intermittent RBC flow in capillaries results in discontinuous and fragmentary capillary images. To overcome this problem, we used Evans Blue (EB) dye as a contrast agent for in vivo photoacoustic imaging. EB has strong optical absorption at 610 nm and distributes uniformly in the blood stream by chemically binding to albumin. By intravenous injection of EB (6%, 200 μL), complete and continuous microvascular networks-especially capillaries-of the ears of nude mice were imaged. The diffusion of EB (3%, 100 μL) leaving the blood stream was monitored for 2 hours. At lower administration dose of EB (3%, 50 μL), the clearance of the EB-albumin complex was imaged for 10 days and quantitatively investigated using a two-compartment model.

Effect of electron beam irradiation on thermal and mechanical properties of epoxy polymer

NASA Astrophysics Data System (ADS)

Nguyen, A. T.; Visakh, P. M.; Nazarenko, O. B.; Chandran, C. S.; Melnikova, T. V.

2017-01-01

This study investigates the thermal and mechanical properties of epoxy polymer after exposure to different doses of electron beam irradiation. The epoxy polymer was prepared using epoxy-diane resin ED-20 cured by polyethylenepolyamine. The irradiation of the samples was carried out with doses of 30, 100 and 300 kGy. The effects of doses on thermal and mechanical properties of the epoxy polymer were investigated by the methods of thermal gravimetric analysis, tensile test, and dynamic mechanical analysis. The thermal properties of the epoxy polymer slightly increased after irradiation at the heating in air. The tensile strength and Young’s modulus of the epoxy polymer increased by the action of electron beam up to dose of 100 kGy and then decreased. The elongation at break decreased with increasing the irradiation dose.

47 CFR 27.1214 - EBS spectrum leasing arrangements and grandfathered leases.

Code of Federal Regulations, 2010 CFR

2010-10-01

... not employ channel loading technology. (3) The licensee may shift its requisite EBS educational usage... educational use requirements in light of changes in educational needs, technology, and other relevant factors... Educational Broadband Service § 27.1214 EBS spectrum leasing arrangements and grandfathered leases. (a) A...

Teacher Preparation for Emergent Bilingual Students: Implications of Evidence for Policy

ERIC Educational Resources Information Center

López, Francesca; Santibañez, Lucrecia

2018-01-01

Failure to adequately prepare teachers of emergent bilingual (EB) students could have devastating consequences for student achievement, EB reclassification, and eventually, high school and college completion. To enhance the policy discourse, we explore how teacher certification requirements relate to both EB student achievement and teacher…

Bag molding processes

NASA Astrophysics Data System (ADS)

Slobodzinsky, A.

Features, materials, and techniques of vacuum, pressure, and autoclave FRP bag molding processes are described. The bags are used in sealed environments, inflated to flexibly force a curing FRP laminate to conform to a stiff mold form which defines the shape of the finished product. Densification is achieved as the bag presses out the voids and excess resin from the laminate, and consolidation occurs as the plies and adherends are bonded by the bag pressure. Curing techniques nominally involved room temperature or high temperature, and investigations of alternative techniques, such as induction, dielectric, microwave, xenon flash, UV, electron beam, and gamma radiation heating are proceeding. Polysulfone is the most common thermoplastic. Details are given of mold preparations, peel plies or release films and fabrics, bagging techniques, and reusable venting blankets and silicone rubber bags.

The Beaverdam Group: Archaeological Investigations at 9EB92, 9EB207, 9EB208 and 9EB219 Richard B. Russell Multiple Resource Area, Elbert County, Georgia.

DTIC Science & Technology

1984-01-01

soapstone (steatite) for both vessels and 0 cooking stones, basin mortars, phyllite and slate knives, round or stemmed scrapers, three-quarter or full...gneissic rock, and soapstone . During sub- sequent review, it was pointed out that the use of quartzite for tool manufacture is without precedent in the...fashioned from non-local materials. Quartz, meta-igneous rock and soapstone could be found within 10 km of the Beaverdain Group, whereas other lithic

End-binding protein 1 controls signal propagation from the T cell receptor

PubMed Central

Martín-Cófreces, Noa B; Baixauli, Francesc; López, María J; Gil, Diana; Monjas, Alicia; Alarcón, Balbino; Sánchez-Madrid, Francisco

2012-01-01

The role of microtubules (MTs) in the control and dynamics of the immune synapse (IS) remains unresolved. Here, we show that T cell activation requires the growth of MTs mediated by the plus-end specific protein end-binding 1 (EB1). A direct interaction of the T cell receptor (TCR) complex with EB1 provides the molecular basis for EB1 activity promoting TCR encounter with signalling vesicles at the IS. EB1 knockdown alters TCR dynamics at the IS and prevents propagation of the TCR activation signal to LAT, thus inhibiting activation of PLCγ1 and its localization to the IS. These results identify a role for EB1 interaction with the TCR in controlling TCR sorting and its connection with the LAT/PLCγ1 signalosome. PMID:22922463

Evaluation of emamectin benzoate and substance EX against salmon lice in sea-ranched Atlantic salmon smolts.

PubMed

Skilbrei, Ove Tommy; Espedal, Per Gunnar; Nilsen, Frank; Garcia, Enrique Perez; Glover, Kevin A

2015-04-08

Experimental releases of Atlantic salmon smolts treated with emamectin benzoate (EB) against salmon lice have previously been used to estimate the significance of salmon lice on the survival of migrating smolts. In recent years, the salmon louse has developed reduced sensitivity to EB, which may influence the results of such release experiments. We therefore tested the use of 2 anti-lice drugs: EB was administered to salmon smolts in high doses by intra-peritoneal injection and the prophylactic substance EX (SubEX) was administered by bathing. A third, untreated control group was also established. Salmon were challenged with copepodids of 2 strains of salmon lice (1 EB-sensitive strain and 1 with reduced EB-sensitivity) in mixed-group experimental tanks. At 31 d post-challenge, the numbers of pre-adult lice on treated fish were around 20% compared with the control fish, with minor or no differences between the 2 treatments and lice strains. Both treatments therefore appeared to give the smolts a high degree of protection against infestation of copepodids of salmon lice. However, significantly lower growth of the EB-treatment group indicates that bathing the fish in SubEX is less stressful for smolts than intra-peritoneal injection of EB.

FINE-SCALE PHOTOSPHERIC CONNECTIONS OF ELLERMAN BOMBS

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

Yang, Heesu; Chae, Jongchul; Song, Donguk

2016-10-01

We investigate the photospheric and magnetic field structures associated with Ellerman bombs (EBs) using the 1.6 m New Solar Telescope at Big Bear Solar Observatory. The nine observed EBs were accompanied by elongated granule-like features (EGFs) that showed transverse motions prior to the EBs with an average speed of about 3.8 km s{sup −1}. Each EGF consisted of a sub-arcsecond bright core encircled by a dark lane around its moving front. The bright core appeared in the TiO broadband filter images and in the far wings of the H α and Ca ii 8542 Å lines. In four EBs, themore » bi-directional expanding motion of the EGFs was identified in the TiO images. In those cases, the EGFs were found to be accompanied by an emerging flux (EF). In four other EBs, the EGF developed at the edge of a penumbra and traveled in the sunspot’s radial direction. The EGFs in these cases were identified as a moving magnetic feature (MMF). Our results show a clear connection among the magnetic elements, photospheric features, and EBs. This result suggests that the EBs result from magnetic reconnection forced by EFs or MMFs that are frequently manifested by EGFs.« less

Isotope Dilution nanoLC/ESI+-HRMS3 Quantitation of Urinary N7-(1-Hydroxy-3-buten-2-yl) Guanine Adducts in Humans and Their Use as Biomarkers of Exposure to 1,3-Butadiene.

PubMed

Sangaraju, Dewakar; Boldry, Emily J; Patel, Yesha M; Walker, Vernon; Stepanov, Irina; Stram, Daniel; Hatsukami, Dorothy; Tretyakova, Natalia

2017-02-20

1,3-Butadiene (BD) is an important industrial and environmental chemical classified as a known human carcinogen. Occupational exposure to BD in the polymer and monomer industries is associated with an increased incidence of lymphoma. BD is present in automobile exhaust, cigarette smoke, and forest fires, raising concern about potential exposure of the general population to this carcinogen. Following inhalation exposure, BD is bioactivated to 3,4-epoxy-1-butene (EB). If not detoxified, EB is capable of modifying guanine and adenine bases of DNA to form nucleobase adducts, which interfere with accurate DNA replication and cause cancer-initiating mutations. We have developed a nanoLC/ESI + -HRMS 3 methodology for N7-(1-hydroxy-3-buten-2-yl) guanine (EB-GII) adducts in human urine (limit of detection: 0.25 fmol/mL urine; limit of quantitation: 1.0 fmol/mL urine). This new method was successfully used to quantify EB-GII in urine of F344 rats treated with 0-200 ppm of BD, occupationally exposed workers, and smokers belonging to two different ethnic groups. EB-GII amounts increased in a dose-dependent manner in urine of laboratory rats exposed to 0, 62.5, or 200 ppm of BD. Urinary EB-GII levels were significantly increased in workers occupationally exposed to 0.1-2.2 ppm of BD (1.25 ± 0.51 pg/mg of creatinine) as compared to administrative controls exposed to <0.01 ppm of BD (0.22 ± 0.08 and pg/mg of creatinine) (p = 0.0024), validating the use of EB-GII as a biomarker of human exposure to BD. EB-GII was also detected in smokers' urine with European American smokers excreting significantly higher amounts of EB-GII than African American smokers (0.48 ± 0.09 vs 0.12 ± 0.02 pg/mg of creatinine, p = 3.1 × 10 -7 ). Interestingly, small amounts of EB-GII were observed in animals and humans with no known exposure to BD, providing preliminary evidence for its endogenous formation. Urinary EB-GII adduct levels and urinary mercapturic acids of BD (MHBMA, DHBMA) were compared in a genotyped multiethnic smoker cohort.

Radiation effects program

NASA Astrophysics Data System (ADS)

1985-09-01

No existing LINAC Based Beam Heating facility comes within a factor of ten of the needs of a high heating rate thermodynamic properties research facility. The facility could be built at the Naval Research Lab. for a cost in the neighborhood of 2 million dollars. The 10 MeV electron beam would not produce any serious radioactivity but would provide unprecedented beam power for such other applications as food processing, sewer treatment, materials curing, radiation hardness assurance, etc. One can always achieve lower current densities by scattering the beam and moving the device under test further away from the scatterer. In this case one must rely on the TLD readings to indicate the dose rate at the point of interest. For general utility with the beam covering about four TLD's fairly evenly one can claim that the NRL LINAC can produce a maximum dose rate of about 6 x 10 to the 10th power rads (Si) per second for a pulse length of 1.5 microseconds, and about 1.4 x 10 to the 11th power rads (Si) per second in a 50 nanosecond pulse. In both cases the beam area is about 0.4 square centimeters.

Vertically aligned double wall carbon nanotube arrays adsorbent for pure and mixture adsorption of H2S, ethylbenzene and carbon monoxide, grand canonical Monte Carlo simulation.

PubMed

Tasharrofi, Saeideh; Taghdisian, Hossein; Golchoobi, Abdollah

2018-05-01

In this study, pure and ternary adsorption of hydrogen sulfide (H 2 S), ethylbenzene (EB), and carbon monoxide (CO) on different arrays of zigzag double wall carbon nanotube was investigated using grand canonical Monte Carlo simulations. The internal diameters of nanotube were fixed at 2r = 50.17 Å while nanotube wall distances were different values from d = 0 Å to d = 150 Å. Pure simulation results indicated that adsorption quantity of H 2 S and EB in low pressure ranges of P = 1.9 bar to P = 3.1 bar was at least 100% more than CO adsorption quantities. At high pressure ranges of P = 23.1 bar to P = 38.2 bar H 2 S adsorption was greater than EB and CO by about 200 molecules per unit cell (UC) at low nanotube distances. This was related to smaller kinetic diameter and greater dipole moment of H 2 S compared to EB and CO. At higher nanotube distance the effect of size however disappears and all three gases approach to adsorption quantity of about 800 molecules/UC. Graphical representation of adsorption areas showed that H 2 S and CO form multilayer adsorption around nanotube inner and outer walls while EB fill the whole space uniformly without any congestion around the walls. Ternary adsorption results EB/CO and H 2 S/CO selectivity are greater than EB/H 2 S selectivity. In addition, at smaller nanotube distances H 2 S/CO selectivity is generally higher than EB/CO selectivity, which at higher nanotube distance the order becomes revers suggesting that size dependent effects on adsorption vanishes. Isosteric heat of adsorption shows that the order of EB > H 2 S > CO suggesting that ethylbenzene interaction with nanotube arrays was strongest. Although H 2 S has a greater dipole moment and smaller molecular dimension, EB adsorption at higher nanotube distance is greater than H 2 S by at least 50% probably because EB is less volatile. Copyright © 2018 Elsevier Inc. All rights reserved.

Comparison of endoscopic papillary balloon dilation and sphincterotomy in young patients with CBD stones and gallstones.

PubMed

Seo, Yu Ri; Moon, Jong Ho; Choi, Hyun Jong; Kim, Dong Choon; Ha, Ji Su; Lee, Tae Hoon; Cha, Sang-Woo; Cho, Young Deok; Park, Sang-Heum; Kim, Sun-Joo

2014-05-01

Endoscopic biliary sphincterotomy (EBS) results in permanent loss of sphincter function and its long-term complications are unknown. Endoscopic papillary balloon dilation (EPBD) is an alternative procedure that preserves sphincter function, although it is associated with a higher risk of pancreatitis than is EBS. The aim of this study was to evaluate the safety and outcomes of EPBD with limited indications for removal of common bile duct (CBD) stones combined with gallstones in patients younger than 40 years. Young (age < 40 years) patients who had CBD stones combined with gallstones on imaging studies were enrolled in this study. A total of 132 patients were randomly divided into the EPBD group (n = 62) or the EBS group (n = 70) for extraction of CBD stones. The ballooning size of EPBD ranged from 6 to 10 mm. Complete bile duct clearance was achieved in 98.4 % (61/62) of the EPBD group and 100 % (70/70) of the EBS group. Mechanical lithotripsy was required in 8.1 % (5/62) of the EPBD group and 8.6 % (6/70) of the EBS group. The early complication rates were 8.1 % (5/62) (five pancreatitis) in the EPBD group and 11.4 % (8/70) (five [7.1 %] pancreatitis, two bleeding and one perforation) in the EBS group. The recurrence rates of CBD stones were 1.6 % (1/62) in the EPBD group and 5.7 % (4/70) in the EBS group. EPBD with limited indications was safe and effective as EBS for removal of CBD stones combined with gallstones in young patients who had a longer life expectancy.

Composite of PAH-degrading endophytic bacteria reduces contamination and health risks caused by PAHs in vegetables.

PubMed

Wang, Jian; Liu, Juan; Ling, Wanting; Huang, Qingguo; Gao, Yanzheng

2017-11-15

Vegetables accumulate polycyclic aromatic hydrocarbons (PAHs) at high concentrations when grown in contaminated sites. Inoculation with PAH-degrading endophytic bacteria (EB PAH ) has been recognized as one of the most promising ways to remove PAHs from plant bodies; however, the performance of single endophytic bacteria is generally limited. This investigation used a composite of eight EB PAH to reduce the contamination and health risk posed by 16 EPA priority PAHs in vegetables including Chinese cabbage (Brassica chinensis L.) and pakchoi (Brassica campestris L.). Composite EB PAH have strong PAH degradation abilities, and more than 65% of ∑PAH were degraded after 10-day insuspension with composite EB PAH . Vegetable were contacted with composite EB PAH by seed soaking (SS) and leaf painting (LP) with an EB PAH cell incubation at OD 600nm =0.2-1.5. Compared with those in non-inoculated controls, the ∑PAH concentrations in edible parts of Chinese cabbage and pakchoi colonized by composite EB PAH via SS and LP with bacterial suspension at OD 600nm =0.2-1.5 were 42.07-70.77% and 15.79-53.20% lower, and the incremental lifetime cancer risk (ILCR) values for males and females were 31.78-84.08% and 26.60-83.40% smaller, respectively. SS was the optimal inoculation method for reducing PAH concentrations and ILCR values. Our results indicate that inoculating plants with composite EB PAH can lower the health risk posed by vegetables contaminated with PAHs, and may be used to mitigate plant PAH contamination. Copyright © 2017 Elsevier B.V. All rights reserved.

77 FR 7603 - Notice of a Change in Status of an Extended Benefit (EB) Period for Alaska

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-13

... Extended Benefit (EB) Period for Alaska AGENCY: Employment and Training Administration, Labor. ACTION... Extended Benefits program began January 22, 2012. The trigger notice covering state eligibility for the EB... governed by the Federal- State Extended Unemployment Compensation Act of 1970, as amended, and the...

An embeddable optical strain gauge based on a buckled beam.

PubMed

Du, Yang; Chen, Yizheng; Zhu, Chen; Zhuang, Yiyang; Huang, Jie

2017-11-01

We report, for the first time, a low cost, compact, and novel mechanically designed extrinsic Fabry-Perot interferometer (EFPI)-based optical fiber sensor with a strain amplification mechanism for strain measurement. The fundamental design principle includes a buckled beam with a coated gold layer, mounted on two grips. A Fabry-Perot cavity is produced between the buckled beam and the endface of a single mode fiber (SMF). A ceramic ferrule is applied for supporting and orienting the SMF. The principal sensor elements are packaged and protected by two designed metal shells. The midpoint of the buckled beam will experience a deflection vertically when the beam is subjected to a horizontally/axially compressive displacement. It has been found that the vertical deflection of the beam at midpoint can be 6-17 times larger than the horizontal/axial displacement, which forms the basis of a strain amplification mechanism. The user-configurable buckling beam geometry-based strain amplification mechanism enables the strain sensor to achieve a wide range of strain measurement sensitivities. The designed EFPI was used to monitor shrinkage of a square brick of mortar. The strain was measured during the drying/curing stage. We envision that it could be a good strain sensor to be embedded in civil materials/structures under a harsh environment for a prolonged period of time.

An embeddable optical strain gauge based on a buckled beam

NASA Astrophysics Data System (ADS)

Du, Yang; Chen, Yizheng; Zhu, Chen; Zhuang, Yiyang; Huang, Jie

2017-11-01

We report, for the first time, a low cost, compact, and novel mechanically designed extrinsic Fabry-Perot interferometer (EFPI)-based optical fiber sensor with a strain amplification mechanism for strain measurement. The fundamental design principle includes a buckled beam with a coated gold layer, mounted on two grips. A Fabry-Perot cavity is produced between the buckled beam and the endface of a single mode fiber (SMF). A ceramic ferrule is applied for supporting and orienting the SMF. The principal sensor elements are packaged and protected by two designed metal shells. The midpoint of the buckled beam will experience a deflection vertically when the beam is subjected to a horizontally/axially compressive displacement. It has been found that the vertical deflection of the beam at midpoint can be 6-17 times larger than the horizontal/axial displacement, which forms the basis of a strain amplification mechanism. The user-configurable buckling beam geometry-based strain amplification mechanism enables the strain sensor to achieve a wide range of strain measurement sensitivities. The designed EFPI was used to monitor shrinkage of a square brick of mortar. The strain was measured during the drying/curing stage. We envision that it could be a good strain sensor to be embedded in civil materials/structures under a harsh environment for a prolonged period of time.

Cresting the wave: proper motions of the Eastern Banded Structure

NASA Astrophysics Data System (ADS)

Deason, Alis J.; Belokurov, Vasily; Koposov, Sergey E.

2018-01-01

We study the kinematic properties of the Eastern Banded Structure (EBS) and Hydra I overdensity using exquisite proper motions derived from the Sloan Digital Sky Survey (SDSS) and Gaia source catalogue. Main sequence turn-off stars in the vicinity of the EBS are identified from SDSS photometry; we use the proper motions and, where applicable, spectroscopic measurements of these stars to probe the kinematics of this apparent stream. We find that the EBS and Hydra I share common kinematic and chemical properties with the nearby Monoceros Ring. In particular, the proper motions of the EBS, like Monoceros, are indicative of prograde rotation (Vϕ ∼ 180-220 km s-1), which is similar to the Galactic thick disc. The kinematic structure of stars in the vicinity of the EBS suggests that it is not a distinct stellar stream, but rather marks the 'edge' of the Monoceros Ring. The EBS and Hydra I are the latest substructures to be linked with Monoceros, leaving the Galactic anti-centre a mess of interlinked overdensities which likely share a unified, Galactic disc origin.

A rare case of skin blistering and esophageal stenosis in the course of epidermolysis bullosa - case report and literature review.

PubMed

Michalak, Agata; Cichoż-Lach, Halina; Prozorow-Król, Beata; Buk, Leszek; Dzida, Monika

2018-04-13

Epidermolysis bullosa (EB) constitutes a heterogenous group of rare multisystem genetically transmitted disorders comprising several blistering muco-cutaneous diseases with a monogenic basis and either autosomal dominant or autosomal recessive mode of inheritance. EB manifestation is not only limited to the skin. Systemic signs might involve the nose, ear, eye, genitourinary tract and upper gastrointestinal tract. The presence of particular symptoms is directly determined by a type of altered skin protein. Gastrointestinal manifestation of EB is most commonly reflected by esophageal stenosis due to recurrent esophageal blistering, followed by consequent scarring. Here we present a case of a man with dystrophic EB and dysphagia, skin blistering, joints contractures and missing nails. To our knowledge, the presented man is the oldest one diagnosed with EB living in Poland. Management of an esophageal stricture in such circumstances is based on endoscopic dilatation. However, in most severe cases, placement of a gastrostomy tube is required. Despite great advances in medicine, a targeted therapy in the course of EB has not been established yet.

Memory scrutinized through electrical brain stimulation: A review of 80 years of experiential phenomena.

PubMed

Curot, Jonathan; Busigny, Thomas; Valton, Luc; Denuelle, Marie; Vignal, Jean-Pierre; Maillard, Louis; Chauvel, Patrick; Pariente, Jérémie; Trebuchon, Agnès; Bartolomei, Fabrice; Barbeau, Emmanuel J

2017-07-01

Electrical brain stimulations (EBS) sometimes induce reminiscences, but it is largely unknown what type of memories they can trigger. We reviewed 80 years of literature on reminiscences induced by EBS and added our own database. We classified them according to modern conceptions of memory. We observed a surprisingly large variety of reminiscences covering all aspects of declarative memory. However, most were poorly detailed and only a few were episodic. This result does not support theories of a highly stable and detailed memory, as initially postulated, and still widely believed as true by the general public. Moreover, memory networks could only be activated by some of their nodes: 94.1% of EBS were temporal, although the parietal and frontal lobes, also involved in memory networks, were stimulated. The qualitative nature of memories largely depended on the site of stimulation: EBS to rhinal cortex mostly induced personal semantic reminiscences, while only hippocampal EBS induced episodic memories. This result supports the view that EBS can activate memory in predictable ways in humans. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Nurses' Perceptions of Implementing Fall Prevention Interventions to Mitigate Patient-Specific Fall Risk Factors.

PubMed

Wilson, Deleise S; Montie, Mary; Conlon, Paul; Reynolds, Margaret; Ripley, Robert; Titler, Marita G

2016-08-01

Evidence-based (EB) fall prevention interventions to mitigate patient-specific fall risk factors are readily available but not routinely used in practice. Few studies have examined nurses' perceptions about both the use of these EB interventions and implementation strategies designed to promote their adoption. This article reports qualitative findings of nurses' perceptions about use of EB fall prevention interventions to mitigate patient-specific fall risks, and implementation strategies to promote use of these interventions. The findings revealed five major themes: before-study fall prevention practices, use of EB fall prevention interventions tailored to patient-specific fall risk factors, beneficial implementation strategies, overall impact on approach to fall prevention, and challenges These findings are useful to guide nurses' engagement and use of EB fall prevention practices tailored to patient-specific fall risk factors. © The Author(s) 2016.

Multi-wavelength analysis of Ellerman Bomb Light Curves

NASA Astrophysics Data System (ADS)

Herlender, M.; Berlicki, A.

We present the results of a multi-wavelength photometric analysis of Ellerman Bomb (EB) observations obtained from the Dutch Open Telescope. In our data we have found 6 EBs located in the super-penumbra of the main spot in the active region NOAA 10781. We present light curves of EB observed in the Hα line centre and wing +0.7 Å, in the Ca II H line centre and wing~+2.35 Å, in the G-band and in the TRACE 1600 Å filter. We have shown that EBs were visible in the G-band and moreover, there was a good correlation between the light curves in the G-band and in the Hα line wings. We also found quasi-periodic oscillations of EBs brightness in the G-band, CaII H line and TRACE 1600 Å filter.

From Here to ET

NASA Astrophysics Data System (ADS)

Mathews, J. D.

SETI (Search for ExtraTerrestrial Intelligence) has thus far proven negative. The assumptions that have driven these searches are reexamined to determine if a new paradigm for future searches can be identified. To this end, the apparent path of evolving human exploration of the solar system and the local galaxy is used to assess where it might lead in the relative near future while noting that we are not overtly intending to contact ET (ExtraTerrestrials). The basic premise is that human space exploration must be highly efficient, cost effective, and autonomous as placing humans beyond low Earth orbit is fraught with political, economic, and technical difficulties. With this basis, it is concluded that only by developing and deploying self-replicating robotic spacecraft--and the incumbent communication systems--can the human race efficiently explore even the asteroid belt let alone the vast reaches of the Kuiper Belt, Oort Cloud, and beyond. It is assumed that ET would have followed a similar path. The technical practicality of and our progress towards this autonomous, self-replicating exobot--Explorer roBot or EB--is further examined with the conclusion that the narrow-beam, laser-based communication network that would likely be em- ployed, would be difficult to detect from a nearby star systems thus offering an explanation of the failure of SETI to date. It is further argued, as have others, that EBs are likely a common feature of the galaxy.

Monitoring Delamination of Thermal Barrier Coatings by Near-Infrared and Upconversion Luminescence Imaging

NASA Technical Reports Server (NTRS)

Eldridge, J. I.; Martin, R. E.; Singh, Jogender; Wolfe, Doug E.

2008-01-01

Previous work has demonstrated that TBC delamination can be monitored by incorporating a thin luminescent sublayer that produces greatly increased luminescence intensity from delaminated regions of the TBC. Initial efforts utilized visible-wavelength luminescence from either europium or erbium doped sublayers. This approach exhibited good sensitivity to delamination of electron-beam physical-vapor-deposited (EB-PVD) TBCs, but limited sensitivity to delamination of the more highly scattering plasma-sprayed TBCs due to stronger optical scattering and to interference by luminescence from rare-earth impurities. These difficulties have now been overcome by new strategies employing near-infrared (NIR) and upconversion luminescence imaging. NIR luminescence at 1550 nm was produced in an erbium plus ytterbium co-doped yttria-stabilized zirconia (YSZ) luminescent sublayer using 980-nm excitation. Compared to visible-wavelength luminescence, these NIR emission and excitation wavelengths are much more weakly scattered by the TBC and therefore show much improved depth-probing capabilities. In addition, two-photon upconversion luminescence excitation at 980 nm wavelength produces luminescence emission at 562 nm with near-zero fluorescence background and exceptional contrast for delamination indication. The ability to detect TBC delamination produced by Rockwell indentation and by furnace cycling is demonstrated for both EB-PVD and plasma-sprayed TBCs. The relative strengths of the NIR and upconversion luminescence methods for monitoring TBC delamination are discussed.

Esophageal Sensorimotor Function and Psychological Factors Each Contribute to Symptom Severity in Globus Patients.

PubMed

Rommel, Nathalie; Van Oudenhove, Lukas; Arts, Joris; Caenepeel, Philip; Tack, Jan; Pauwels, Ans

2016-10-01

Altered upper esophageal sphincter (UES) and esophageal body (EB) sensorimotor function and psychosocial factors may both be involved in symptom generation in globus, but their common impact is not yet assessed. The aim of the study is (1) to compare UES and EB sensitivity and compliance of globus patients with healthy controls (HC); (2) to study the association of globus symptom severity (GSS) with UES and EB sensitivity and compliance, UES motor function and psychosocial factors. In 58 globus patients, GSS, somatization, and anxiety disorders were determined using validated questionnaires. In 26 HC and 42/58 patients, UES and EB sensitivity and compliance were assessed twice using barostat measurements. UES function of 27 globus patients was evaluated using high-resolution manometry. Bivariate correlations and a general linear model tested the association of these factors with GSS. UES and EB compliance did not differ between globus patients and HC. Upon repeated distension, UES habituation was seen in both groups, whereas EB sensitization (23.3±1.3 vs. 19.5±1.5 mm Hg, P<0.0001) only occurred in globus patients, (P=0.038). UES compliance (ρ=0.37, P=0.04), change in EB compliance upon repeated distension (ρ=0.45, P=0.007), somatization (ρ=0.43, P=0.003), panic disorder (t=3.04, P=0.004), and post-traumatic stress severity (ρ=0.40, P=0.005) were associated with GSS. UES compliance and somatization were independently associated with GSS. A trend (P=0.061) was found for the association of GSS with change in EB compliance. UES compliance, change in EB compliance, and somatization explain 40% of the variance in GSS. This indicates that globus is a complex disorder of the brain-gut axis rather than a "psychosomatic" disorder or a peripheral esophageal disorder.

Can ill-structured problems reveal beliefs about medical knowledge and knowing? A focus-group approach

PubMed Central

Roex, Ann; Clarebout, Geraldine; Dory, Valerie; Degryse, Jan

2009-01-01

Background Epistemological beliefs (EB) are an individual's cognitions about knowledge and knowing. In several non-medical domains, EB have been found to contribute to the way individuals reason when faced with ill-structured problems (i.e. problems with no clear-cut, right or wrong solutions). Such problems are very common in medical practice. Determining whether EB are also influential in reasoning processes with regard to medical issues to which there is no straightforward answer, could have implications for medical education. This study focused on 2 research questions: 1. Can ill-structured problems be used to elicit general practice trainees' and trainers' EB? and 2. What are the views of general practice trainees and trainers about knowledge and how do they justify knowing? Methods 2 focus groups of trainees (n = 18) were convened on 3 occasions during their 1st year of postgraduate GP training. 2 groups of GP trainers (n = 11) met on one occasion. Based on the methodology of the Reflective Judgement Interview (RJI), participants were asked to comment on 11 ill-structured problems. The sessions were audio taped and transcribed and an adapted version of the RJI scoring rules was used to assess the trainees' reasoning about ill-structured problems. Results Participants made a number of statements illustrating their EB and their importance in clinical reasoning. The level of EB varied widely form one meeting to another and depending on the problem addressed. Overall, the EB expressed by trainees did not differ from those of trainers except on a particular ill-structured problem regarding shoulder pain. Conclusion The use of focus groups has entailed some difficulties in the interpretation of the results, but a number of preliminary conclusions can be drawn. Ill-structured medical problems can be used to elicit EB. Most trainees and trainers displayed pre-reflective and quasi-reflective EB. The way trainees and doctors view and justify knowledge are likely to be involved in medical reasoning processes. PMID:19775425

Collagen-IV supported embryoid bodies formation and differentiation from buffalo (Bubalus bubalis) embryonic stem cells

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

Taru Sharma, G., E-mail: gts553@gmail.com; Dubey, Pawan K.; Verma, Om Prakash

Graphical abstract: EBs formation, characterization and expression of germinal layers marker genes of in vivo developed teratoma using four different types of extracellular matrices. Highlights: Black-Right-Pointing-Pointer Collagen-IV matrix is found cytocompatible for EBs formation and differentiation. Black-Right-Pointing-Pointer Established 3D microenvironment for ES cells development and differentiation into three germ layers. Black-Right-Pointing-Pointer Collagen-IV may be useful as promising candidate for ES cells based therapeutic applications. -- Abstract: Embryoid bodies (EBs) are used as in vitro model to study early extraembryonic tissue formation and differentiation. In this study, a novel method using three dimensional extracellular matrices for in vitro generation of EBsmore » from buffalo embryonic stem (ES) cells and its differentiation potential by teratoma formation was successfully established. In vitro derived inner cell masses (ICMs) of hatched buffalo blastocyst were cultured on buffalo fetal fibroblast feeder layer for primary cell colony formation. For generation of EBs, pluripotent ES cells were seeded onto four different types of extracellular matrices viz; collagen-IV, laminin, fibronectin and matrigel using undifferentiating ES cell culture medium. After 5 days of culture, ESCs gradually grew into aggregates and formed simple EBs having circular structures. Twenty-six days later, they formed cystic EBs over collagen matrix with higher EBs formation and greater proliferation rate as compared to other extracellular matrices. Studies involving histological observations, fluorescence microscopy and RT-PCR analysis of the in vivo developed teratoma revealed that presence of all the three germ layer derivatives viz. ectoderm (NCAM), mesoderm (Flk-1) and endoderm (AFP). In conclusion, the method described here demonstrates a simple and cost-effective way of generating EBs from buffalo ES cells. Collagen-IV matrix was found cytocompatible as it supported buffalo EBs formation, their subsequent differentiation could prove to be useful as promising candidate for ES cells based therapeutic applications.« less

SMALL-SCALE STRUCTURING OF ELLERMAN BOMBS AT THE SOLAR LIMB

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

Nelson, C. J.; Doyle, J. G.; Scullion, E. M.

2015-01-01

Ellerman bombs (EBs) have been widely studied in recent years due to their dynamic, explosive nature and apparent links to the underlying photospheric magnetic field implying that they may be formed by magnetic reconnection in the photosphere. Despite a plethora of researches discussing the morphologies of EBs, there has been a limited investigation of how these events appear at the limb, specifically, whether they manifest as vertical extensions away from the disk. In this article, we make use of high-resolution, high-cadence observations of an Active Region at the solar limb, collected by the CRisp Imaging SpectroPolarimeter (CRISP) instrument, to identifymore » EBs and infer their physical properties. The upper atmosphere is also probed using the Solar Dynamic Observatory's Atmospheric Imaging Assembly (SDO/AIA). We analyze 22 EB events evident within these data, finding that 20 appear to follow a parabolic path away from the solar surface at an average speed of 9 km s{sup –1}, extending away from their source by 580 km, before retreating back at a similar speed. These results show strong evidence of vertical motions associated with EBs, possibly explaining the dynamical ''flaring'' (changing in area and intensity) observed in on-disk events. Two in-depth case studies are also presented that highlight the unique dynamical nature of EBs within the lower solar atmosphere. The viewing angle of these observations allows for a direct linkage between these EBs and other small-scale events in the Hα line wings, including a potential flux emergence scenario. The findings presented here suggest that EBs could have a wider-reaching influence on the solar atmosphere than previously thought, as we reveal a direct linkage between EBs and an emerging small-scale loop, and other near-by small-scale explosive events. However, as previous research found, these extensions do not appear to impact upon the Hα line core, and are not observed by the SDO/AIA EUV filters.« less

Multiwavelength spectropolarimetric observations of an Ellerman bomb

NASA Astrophysics Data System (ADS)

Rezaei, R.; Beck, C.

2015-10-01

Context. Ellerman bombs (EBs) are enhanced emission in the wings of the Hα line in the solar spectrum. Aims: We study the structure of an EB in the photosphere and chromosphere. Methods: We analyze simultaneous observations of four chromospheric lines (Hα, Ca ii H, Ca ii IR 854 nm, and He i 1083 nm) as well as two photospheric lines (Fe i 630 and Si i 1082.7 nm) along with high-cadence 160 and 170 nm ultraviolet (UV) continuum filtergrams. Full Stokes data from the Helioseismic and Magnetic Imager (HMI) are used to trace the temporal evolution of the magnetic structure. Results: We identify the EB by excess emission in the wings of the Hα line, a brightening in the UV continuum, and large emission peaks in the core of the two Ca ii lines. The EB shows a blueshift in all chromospheric lines, while no shifts are observed in the photospheric lines. The blueshift in the chromospheric layer causes very asymmetric emission peaks in the Ca ii H line. The photospheric Si i spectral line shows a shallower line depth at the location of the EB. The UV continuum maps show that the EB was substantially brighter than its surroundings for about 30 min. The continuum contrast of the EB from 170 nm to 1080 nm shows a power-law dependency on the wavelength. The temperature enhancement amounts to 130 K in the low photosphere and 400 K at the temperature minimum level. This temperature excess is also seen in an LTE inversion of the Ca ii spectra. The total thermal and radiative energy content of the EB is about 1020 J and 1018 J in the photosphere and chromosphere, respectively. The HMI data hints at a photospheric magnetic flux cancellation as the driver of the EB. Conclusions: Ellerman bombs release the energy in a height range of several pressure scale heights around the temperature minimum such that they affect both the photosphere and the lower chromosphere.

Microtubule plus-end tracking of end-binding protein 1 (EB1) is regulated by CDK5 regulatory subunit-associated protein 2

PubMed Central

Fong, Ka-Wing; Au, Franco K. C.; Jia, Yue; Yang, Shaozhong; Zhou, Liying; Qi, Robert Z.

2017-01-01

Microtubules are polar cytoskeleton filaments that extend via growth at their plus ends. Microtubule plus-end-tracking proteins (+TIPs) accumulate at these growing plus ends to control microtubule dynamics and attachment. The +TIP end-binding protein 1 (EB1) and its homologs possess an autonomous plus-end-tracking mechanism and interact with other known +TIPs, which then recruit those +TIPs to the growing plus ends. A major +TIP class contains the SXIP (Ser-X-Ile-Pro, with X denoting any amino acid residue) motif, known to interact with EB1 and its homologs for plus-end tracking, but the role of SXIP in regulating EB1 activities is unclear. We show here that an interaction of EB1 with the SXIP-containing +TIP CDK5 regulatory subunit-associated protein 2 (CDK5RAP2) regulates several EB1 activities, including microtubule plus-end tracking, dynamics at microtubule plus ends, microtubule and α/β-tubulin binding, and microtubule polymerization. The SXIP motif fused with a dimerization domain from CDK5RAP2 significantly enhanced EB1 plus-end-tracking and microtubule-polymerizing and bundling activities, but the SXIP motif alone failed to do so. An SXIP-binding-deficient EB1 mutant displayed significantly lower microtubule plus-end tracking than the wild-type protein in transfected cells. These results suggest that EB1 cooperates with CDK5RAP2 and perhaps other SXIP-containing +TIPs in tracking growing microtubule tips. We also generated plus-end-tracking chimeras of CDK5RAP2 and the adenomatous polyposis coli protein (APC) and found that overexpression of the dimerization domains interfered with microtubule plus-end tracking of their respective SXIP-containing chimeras. Our results suggest that disruption of SXIP dimerization enables detailed investigations of microtubule plus-end-associated functions of individual SXIP-containing +TIPs. PMID:28320860

Surface phenomena of hydroxyapatite film on the nanopore formed Ti-29Nb-xZr alloy by anodization for bioimplants.

PubMed

Kim, Eun-Ju; Jeong, Yong-Hoon; Choe, Han-Cheol

2013-03-01

In this study, surface phenomena of hydroxyapatite (HA) film on the nanopore formed Ti-29Nb-xZr alloy by anodization for bioimplants have been investigated by electron beam physical vapor deposition (EB-PVD), field emission scanning electron microscope (FE-SEM), X-ray diffractometer (XRD), potentiostat and contact angle. The microstructure of Ti-29Nb-xZr alloys exhibited equiaxed structure and alpha" phase decreased, whereas beta phase increased as Zr content increased. The increment of Zr contents in HA coated nanotubular Ti-29Nb-xZr alloys showed good corrosion potential in 0.9% NaCI solution. The wettability of HA coated nanotubular surface was higher than that of non-coated samples.

SNS STRIPPER FOIL FAILURE MODES AND THEIR CURES

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

Galambos, John D; Luck, Chris; Plum, Michael A

2010-01-01

The diamond stripper foils in use at the Spallation Neutron Source worked successfully with no failures until May 3, 2009, when we started experiencing a rash of foil system failures after increasing the beam power to ~840 kW. The main contributors to the failures are thought to be 1) convoy electrons, stripped from the incoming H beam, that strike the foil bracket and may also reflect back from the electron catcher, and 2) vacuum breakdown from the charge developed on the foil by secondary electron emission. In this paper we will detail these and other failure mechanisms, and describe themore » improvements we have made to mitigate them.« less

New halo formation mechanism at the KEK compact energy recovery linac

NASA Astrophysics Data System (ADS)

Tanaka, Olga; Nakamura, Norio; Shimada, Miho; Miyajima, Tsukasa; Ueda, Akira; Obina, Takashi; Takai, Ryota

2018-02-01

The beam halo mitigation is a very important challenge for reliable and safe operation of a high-energy machine. A systematic beam halo study was conducted at the KEK compact energy recovery linac (cERL) since non-negligible beam loss was observed in the recirculation loop during a common operation. We found that the beam loss can be avoided by making use of the collimation system. Beam halo measurements have demonstrated the presence of vertical beam halos at multiple locations in the beam line (except the region near the electron gun). Based on these observations, we made a conjecture that the transverse beam halo is attributed to the longitudinal bunch tail arising at the photocathode. The transfer of particles from the longitudinal space to a transverse halo may have been observed and studied in other machines, considering nonlinear effects as their causes. However, our study demonstrates a new unique halo formation mechanism, in which a transverse beam halo can be generated by a longitudinal bunch tail due to transverse rf kicks from the accelerating (monopole) fields of the radio-frequency cavities. This halo formation occurs when nonrelativistic particles enter the cavities with a transverse offset, even if neither nonlinear optics nor nonlinear beam effects are present. A careful realignment of the injector system will mitigate the present halo. Another possible cure is to reduce the bunch tails by changing the photocathode material from the present GaAs to a multi-alkali that is known to have a shorter longitudinal tail.

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

Zhang, Rubing, E-mail: zrb86411680@126.com; Zhang, Yaoyao; Liu, Qiang

TiAl/Nb and TiAl/NiCoCrAl laminate composite sheets with a thickness of 0.4–0.6 mm and dimensions of 150 mm × 100 mm were successfully fabricated by electron beam physical vapor deposition. The microstructures of the sheets were examined, and their mechanical properties were compared with those of TiAl monolithic sheet produced by electron beam physical vapor deposition. Tensile testing was performed at room temperature and 750 °C, and the fracture surfaces were examined by scanning electron microscopy. Among the three microlaminate sheets, the TiAl/NiCoCrAl micro-laminate sheet had the best comprehensive properties at room temperature, and the TiAl/Nb micro-laminate sheet showed the idealmore » high-temperature strength and plasticity at 750 °C. The result was discussed in terms of metal strengthening mechanism. - Highlights: • TiAl-based multilayer foils was fabricated successfully by using EB-PVD method; • The tensile properties and micro-fracture morphologies of the sheet were investigated; • The deformation behavior of the multilayer foils was discussed.« less

Effect of electron beam irradiation on thermal and crystallization behavior of PP/EPDM blend

NASA Astrophysics Data System (ADS)

Balaji, Anand Bellam; Ratnam, Chantara Thevy; Khalid, Mohammad; Walvekar, Rashmi

2017-12-01

The irradiation stability of ethylene-propylene diene terpolymer (EPDM)/ polypropylene (PP) blends is studied in an attempt to develop radiation compatible PP/EPDM blends suitable for medical applications. The PP/EPDM blends with mixing ratios of 80/20, 50/50/ 20/80 were prepared in an internal mixer at 165 °C and a rotor speed of 50 rpm followed by compression molding. The blends and the individual components were irradiated using 3.0 MeV electron beam (EB) accelerator at doses ranging from 0 to 100 kGy in air and room temperature. Later, the PP/EPDM blends were subjected to gel content, thermal stability, crystallization and dynamic mechanical properties before and after irradiation. Results revealed that the irradiation-induced crosslinking in the PP/EPDM blend increases with the increasing irradiation dose and the EPDM content in the blend. However, the thermal stability of the blends did not show any significant changes upon irradiation. The dynamic mechanical analysis shows that the EPDM rich blend has higher compatibility than PP dominant blends. A further improvement in the blend compatibility found to be achieved upon irradiation.

Suppression of the PI3K subunit p85α delays embryoid body development and inhibits cell adhesion.

PubMed

Gurney, Susan M R; Forster, Peter; Just, Ursula; Schwanbeck, Ralf

2011-12-01

Phosphatidylinositol-3-kinases (PI3Ks) exert a variety of signaling functions in eukaryotes. We suppressed the PI3K regulatory subunit p85α using a small interfering RNA (Pik3r1 siRNA) and examined the effects on embryoid body (EB) development in hanging drop culture. We observed a 150% increase in the volume of the treated EBs within 24 h, compared to the negative controls. Fluorescence Activated Cell Sorting (FACS) assays showed that this increase in volume is not due to increased cellular proliferation. Instead, the increase in volume appears to be due to reduced cellular aggregation and adherence. This is further shown by our observation that 40% of treated EBs form twin instead of single EBs, and that they have a significantly reduced ability to adhere to culture dishes when plated. A time course over the first 96 h reveals that the impaired adherence is transient and explained by an initial 12-hour delay in EB development. Quantitative PCR expression analysis suggests that the adhesion molecule integrin-β1 (ITGB1) is transiently downregulated by the p85α suppression. In conclusion we found that suppressing p85α leads to a delay in forming compact EBs, accompanied by a transient inability of the EBs to undergo normal cell-cell and cell-substrate adhesion. Copyright © 2011 Wiley Periodicals, Inc.

Multi-wavelength Spectral Analysis of Ellerman Bombs Observed by FISS and IRIS

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

Hong, Jie; Ding, M. D.; Cao, Wenda, E-mail: dmd@nju.edu.cn

Ellerman bombs (EBs) are a kind of solar activity that is suggested to occur in the lower solar atmosphere. Recent observations using the Interface Region Imaging Spectrograph (IRIS) show connections between EBs and IRIS bombs (IBs), which imply that EBs might be heated to a much higher temperature (8 × 10{sup 4} K) than previous results. Here we perform a spectral analysis of EBs simultaneously observed by the Fast Imaging Solar Spectrograph and IRIS. The observational results show clear evidence of heating in the lower atmosphere, indicated by the wing enhancement in H α , Ca ii 8542 Å, andmore » Mg ii triplet lines and also by brightenings in images of the 1700 Å and 2832 Å ultraviolet continuum channels. Additionally, the intensity of the Mg ii triplet line is correlated with that of H α when an EB occurs, suggesting the possibility of using the triplet as an alternative way to identify EBs. However, we do not find any signal in IRIS hotter lines (C ii and Si iv). For further analysis, we employ a two-cloud model to fit the two chromospheric lines (H α and Ca ii 8542 Å) simultaneously, and obtain a temperature enhancement of 2300 K for a strong EB. This temperature is among the highest of previous modeling results, albeit still insufficient to produce IB signatures at ultraviolet wavelengths.« less

Diagnosis of Inherited Epidermolysis Bullosa in Resource-Limited Settings: Immunohistochemistry Revisited.

PubMed

Yenamandra, Vamsi Krishna; Bhari, Neetu; Ray, Subrata Basu; Sreenivas, Vishnubhatla; Dinda, Amit Kumar; Scaria, Vinod; Sharma, Vinod Kumar; Sethuraman, Gomathy

2017-01-01

Immunofluorescence (IFM) antigen mapping is the most commonly used technique to diagnose and differentiate epidermolysis bullosa (EB). In India, IFM is limited to few research laboratories and is not readily available, making the diagnosis largely clinical and often inaccurate. Ob jective of the Study: To examine the diagnostic usefulness of immunohistochemistry (IHC) as compared to IFM in resource-limited settings. Forty-four consecutive EB patients were included in this study. IHC and IFM were performed on 7-µm frozen tissue sections using standard laboratory protocols with a limited panel of antibodies. The kappa coefficient of agreement was calculated with genetic analysis as the gold standard. IFM and IHC accurately identified the subtype of EB in 80.9% (p < 0.001) of the cases, when a clear blister cavity was evident on biopsy. The sensitivities and specificities of IHC and IFM for diagnosing EB simplex, junctional EB, and dystrophic EB were 100, 100, and 60% and 82.4, 100, and 100%, respectively. IHC was equally effective (p < 0.001) in establishing the type of EB as IFM. IHC staining and its interpretation were simple and comparable to IFM. IHC had an advantage of showing subtle changes in the epidermal architecture that could not be appreciated on IFM and hence can be considered useful in resource-limited settings. © 2017 S. Karger AG, Basel.

ELLERMAN BOMBS WITH JETS: CAUSE AND EFFECT

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

Reid, A.; Mathioudakis, M.; Scullion, E.

2015-05-20

Ellerman Bombs (EBs) are thought to arise as a result of photospheric magnetic reconnection. We use data from the Swedish 1 m Solar Telescope to study EB events on the solar disk and at the limb. Both data sets show that EBs are connected to the foot points of forming chromospheric jets. The limb observations show that a bright structure in the Hα blue wing connects to the EB initially fueling it, leading to the ejection of material upwards. The material moves along a loop structure where a newly formed jet is subsequently observed in the red wing of Hα.more » In the disk data set, an EB initiates a jet which propagates away from the apparent reconnection site within the EB flame. The EB then splits into two, with associated brightenings in the inter-granular lanes. Micro-jets are then observed, extending to 500 km with a lifetime of a few minutes. Observed velocities of the micro-jets are approximately 5–10 km s{sup −1}, while their chromospheric counterparts range from 50 to 80 km s{sup −1}. MURaM simulations of quiet Sun reconnection show that micro-jets with properties similar to those of the observations follow the line of reconnection in the photosphere, with associated Hα brightening at the location of increased temperature.« less

Error-Based Simulation for Error-Awareness in Learning Mechanics: An Evaluation

ERIC Educational Resources Information Center

Horiguchi, Tomoya; Imai, Isao; Toumoto, Takahito; Hirashima, Tsukasa

2014-01-01

Error-based simulation (EBS) has been developed to generate phenomena by using students' erroneous ideas and also offers promise for promoting students' awareness of errors. In this paper, we report the evaluation of EBS used in learning "normal reaction" in a junior high school. An EBS class, where students learned the concept…

77 FR 8901 - Notice of a Change in Status of an Extended Benefit (EB) Period for New Mexico

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-15

... Extended Benefit (EB) Period for New Mexico AGENCY: Employment and Training Administration, Labor. ACTION... State's EB status: The Federal authorization to have a three year look-back was recently extended to... governed by the Federal- State Extended Unemployment Compensation Act of 1970, as amended, and the...

24 CFR 954.4 - Other Federal requirements.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Section 7(b) of the Indian Self-Determination and Education Assistance Act (25 U.S.C. 450e(b)). Section 7...) Definitions. (i) The Indian Self-Determination and Education Assistance Act (25 U.S.C. 450e(b)) defines... Section 7(b) of the Indian Self-Determination and Education Assistance Act (25 U.S.C. 450e(b)) (Indian Act...

Collateral Information for Equating in Small Samples: A Preliminary Investigation

ERIC Educational Resources Information Center

Kim, Sooyeon; Livingston, Samuel A.; Lewis, Charles

2011-01-01

This article describes a preliminary investigation of an empirical Bayes (EB) procedure for using collateral information to improve equating of scores on test forms taken by small numbers of examinees. Resampling studies were done on two different forms of the same test. In each study, EB and non-EB versions of two equating methods--chained linear…

Low-temperature mechanical properties of glass/epoxy laminates

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

Reed, R. P.; Madhukar, M.; Thaicharoenporn, B.

2014-01-27

Selected mechanical properties of glass/epoxy laminate candidates for use in the electrical turn and ground insulation of the ITER Central solenoid (CS) modules were measured. Short-beam shear and flexural tests have been conducted on various E-glass cloth weaves/epoxy laminates at 295 and 77 K. Types of glass weave include 1581, 7500, 7781, and 38050, which represent both satin and plain weaves. The epoxy, planned for use for vacuum-pressure impregnation of the CS module, consists of an anhydride-cured bisphenol F resin system. Inter-laminar shear strength, flexural elastic modulus, and flexural strength have been measured. The data indicate that these properties aremore » dependent on the volume percent of glass. Short-beam shear strength was measured as a function of the span-to-thickness ratio for all laminates at 77 K. Comprehensive fractography was conducted to obtain the failure mode of each short-beam shear test sample.« less

A mass reduction effort of the electric and hybrid vehicle. [composite door panels

NASA Technical Reports Server (NTRS)

Freeman, R. B.; Jahnle, H. A.

1980-01-01

Weight reduction, cost competitiveness, and elimination of the intrusion beam resulted from the redesign and fabrication using composite materials of the door outer panel and intrusion beam from a Chevrolet Impala. The basis of the redesign involved replacing these two steel parts with a single compression molding using the unique approach of simultaneously curing a sheet molding compound outside panel with a continuous glass fiber intrusion strap. A weight reduction of nearly 11 pounds per door was achieved. Additional weight savings are possible by taking advantage of the elimination of the intrusion beam to design thinner door structures. The parts consolidation approach allows the composite structure to be cost competitive with the original steel design for both the lower production car models and for the near to midterm production vehicles using current state of the art composite production techniques. The design, prototype fabrication, costing, material, properties and compression molding production requirements are discussed.

Low-temperature mechanical properties of glass/epoxy laminates

NASA Astrophysics Data System (ADS)

Reed, R. P.; Madhukar, M.; Thaicharoenporn, B.; Martovetsky, N. N.

2014-01-01

Selected mechanical properties of glass/epoxy laminate candidates for use in the electrical turn and ground insulation of the ITER Central solenoid (CS) modules were measured. Short-beam shear and flexural tests have been conducted on various E-glass cloth weaves/epoxy laminates at 295 and 77 K. Types of glass weave include 1581, 7500, 7781, and 38050, which represent both satin and plain weaves. The epoxy, planned for use for vacuum-pressure impregnation of the CS module, consists of an anhydride-cured bisphenol F resin system. Inter-laminar shear strength, flexural elastic modulus, and flexural strength have been measured. The data indicate that these properties are dependent on the volume percent of glass. Short-beam shear strength was measured as a function of the span-to-thickness ratio for all laminates at 77 K. Comprehensive fractography was conducted to obtain the failure mode of each short-beam shear test sample.

Measurement of charged particle yields from therapeutic beams in view of the design of an innovative hadrontherapy dose monitor

NASA Astrophysics Data System (ADS)

Battistoni, G.; Bellini, F.; Bini, F.; Collamati, F.; Collini, F.; De Lucia, E.; Durante, M.; Faccini, R.; Ferroni, F.; Frallicciardi, P. M.; La Tessa, C.; Marafini, M.; Mattei, I.; Miraglia, F.; Morganti, S.; Ortega, P. G.; Patera, V.; Piersanti, L.; Pinci, D.; Russomando, A.; Sarti, A.; Schuy, C.; Sciubba, A.; Senzacqua, M.; Solfaroli Camillocci, E.; Vanstalle, M.; Voena, C.

2015-02-01

Particle Therapy (PT) is an emerging technique, which makes use of charged particles to efficiently cure different kinds of solid tumors. The high precision in the hadrons dose deposition requires an accurate monitoring to prevent the risk of under-dosage of the cancer region or of over-dosage of healthy tissues. Monitoring techniques are currently being developed and are based on the detection of particles produced by the beam interaction into the target, in particular: charged particles, result of target and/or projectile fragmentation, prompt photons coming from nucleus de-excitation and back-to-back γ s, produced in the positron annihilation from β + emitters created in the beam interaction with the target. It has been showed that the hadron beam dose release peak can be spatially correlated with the emission pattern of these secondary particles. Here we report about secondary particles production (charged fragments and prompt γ s) performed at different beam and energies that have a particular relevance for PT applications: 12C beam of 80 MeV/u at LNS, 12C beam 220 MeV/u at GSI, and 12C, 4He, 16O beams with energy in the 50-300 MeV/u range at HIT. Finally, a project for a multimodal dose-monitor device exploiting the prompt photons and charged particles emission will be presented.

Investigation of Fiber Waviness in a Thick Glass Composite Beam Using THz NDE

NASA Technical Reports Server (NTRS)

Anastasi, Robert F.

2008-01-01

Fiber waviness in laminated composite material is introduced during manufacture because of uneven curing, resin shrinkage, or ply buckling caused by bending the composite lay-up into its final shape prior to curing. The resulting waviness has a detrimental effect on mechanical properties, therefore this condition is important to detect and characterize. Ultrasonic characterization methods are difficult to interpret because elastic wave propagation is highly dependent on ply orientation and material stresses. By comparison, the pulsed terahertz response of the composite is shown to provide clear indications of the fiber waviness. Pulsed Terahertz NDE is an electromagnetic inspection method that operates in the frequency range between 300 GHz and 3 THz. Its propagation is influenced by refractive index variations and interfaces. This work applies pulsed Terahertz NDE to the inspection of a thick composite beam with fiber waviness. The sample is a laminated glass composite material approximately 15mm thick with a 90-degree bend. Terahertz response from the planar section, away from the bend, is indicative of a homogeneous material with no major reflections from internal plies, while the multiple reflections at the bend area correspond to the fiber waviness. Results of these measurements are presented for the planar and bend areas.

Method for Fabricating Composite Structures Including Continuous Press Forming and Pultrusion Processing

NASA Technical Reports Server (NTRS)

Farley, Gary L. (Inventor)

1995-01-01

A method for fabricating composite structures at a low-cost, moderate-to-high production rate is disclosed. A first embodiment of the method includes employing a continuous press forming fabrication process. A second embodiment of the method includes employing a pultrusion process for obtaining composite structures. The methods include coating yarns with matrix material, weaving the yarn into fabric to produce a continuous fabric supply, and feeding multiple layers of net-shaped fabrics having optimally oriented fibers into a debulking tool to form an undebulked preform. The continuous press forming fabrication process includes partially debulking the preform, cutting the partially debulked preform, and debulking the partially debulked preform to form a netshape. An electron-beam or similar technique then cures the structure. The pultrusion fabric process includes feeding the undebulked preform into a heated die and gradually debulking the undebulked preform. The undebulked preform in the heated die changes dimension until a desired cross-sectional dimension is achieved. This process further includes obtaining a net-shaped infiltrated uncured preform, cutting the uncured preform to a desired length, and electron-beam curing (or similar technique) the uncured preform. These fabrication methods produce superior structures formed at higher production rates, resulting in lower cost and high structural performance.

Biological effects of the anti-parasitic chemotherapeutant emamectin benzoate on a non-target crustacean, the spot prawn (Pandalus platyceros Brandt, 1851) under laboratory conditions.

PubMed

Veldhoen, Nik; Ikonomou, Michael G; Buday, Craig; Jordan, Jameson; Rehaume, Vicki; Cabecinha, Melissa; Dubetz, Cory; Chamberlain, Jon; Pittroff, Sabrina; Vallée, Kurtis; van Aggelen, Graham; Helbing, Caren C

2012-02-01

The potential impact of commercial salmon aquaculture along the coast of British Columbia on the health of non-target marine wildlife is of growing concern. In the current initiative, the biological effects on gene expression within spot prawn (Pandalus platyceros) exposed to the sea lice controlling agent, emamectin benzoate (EB; 0.1-4.8 mg/kg sediment), were investigated. A mean sediment/water partitioning coefficient (K(p)) was determined to be 21.81 and significant levels of EB were detected in the tail muscle tissue in all exposed animals. Animals selected for the experiment did not have eggs and were of similar weight. Significant mortality was observed within 8 days of EB treatment at concentrations between 0.1 and 0.8 mg/kg and there was no effect of EB on molting. Twelve spot prawn cDNA sequences were isolated from the tail muscle either by directed cloning or subtractive hybridization of control versus EB exposed tissues. Three of the transcripts most affected by EB exposure matched sequences encoding the 60S ribosomal protein L22, spliceosome RNA helicase WM6/UAP56, and the intracellular signal mediator histidine triad nucleotide binding protein 1 suggesting that translation, transcription regulation, and apoptosis pathways were impacted. The mRNA encoding the molting enzyme, β-N-acetylglucosaminidase, was not affected by EB treatment. However, the expression of this transcript was extremely variable making it unsuitable for effects assessment. The results suggest that short-term exposure to EB can impact biological processes within this non-target crustacean. Copyright © 2011 Elsevier B.V. All rights reserved.

Secure fixation of femoral bone plug with a suspensory button in anatomical anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft

PubMed Central

TAKETOMI, SHUJI; INUI, HIROSHI; NAKAMURA, KENSUKE; YAMAGAMI, RYOTA; TAHARA, KEITARO; SANADA, TAKAKI; MASUDA, HIRONARI; TANAKA, SAKAE; NAKAGAWA, TAKUMI

2015-01-01

Purpose the efficacy and safety of using a suspensory button for femoral fixation in anatomical anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone (BPTB) graft have not been established. The purpose of the current study was to evaluate bone plug integration onto the femoral socket and migration of the bone plug and the EndoButton (EB) (Smith & Nephew, Andover, MA, USA) after rectangular tunnel ACL reconstruction with BPTB autograft. Methods thirty-four patients who underwent anatomical rectangular ACL reconstruction with BPTB graft using EB for femoral fixation and in whom three-dimensional (3D) computed tomography (CT) was performed one week and one year after surgery were included in this study. Bone plug integration onto the femoral socket, bone plug migration, soft tissue interposition, EB migration and EB rotation were evaluated on 3D CT. The clinical outcome was also assessed and correlated with the imaging outcomes. Results the bone plug was integrated onto the femoral socket in all cases. The incidence of bone plug migration, soft tissue interposition, EB migration and EB rotation was 15, 15, 9 and 56%, respectively. No significant association was observed between the imaging outcomes. The postoperative mean Lysholm score was 97.1 ± 5.0 points. The postoperative side-to-side difference, evaluated using a KT-2000 arthrometer, averaged 0.5 ± 1.3 mm. There were no complications associated with EB use. Imaging outcomes did not affect the postoperative KT side-to-side difference. Conclusions the EB is considered a reliable device for femoral fixation in anatomical rectangular tunnel ACL reconstruction with BPTB autograft. Level of evidence Level IV, therapeutic case series. PMID:26889465

Vaginocervical stimulation attenuates the sensitization of appetitive sexual behaviors by estradiol benzoate in the ovariectomized rat.

PubMed

Jones, Sherri Lee; Germé, Katuschia; Graham, M Dean; Roy, Patrick; Gardner Gregory, James; Rosenbaum, Stephanie; Parada, Mayte; Pfaus, James G

2015-09-01

The acute administration of estradiol benzoate (EB) to the ovariectomized (OVX) rat induces low levels of lordosis while sexually appetitive behaviors (e.g., hops, darts, solicitations) are absent, yet the repeated administration of EB results in a behavioral sensitization in which lordosis is potentiated and sexually appetitive behaviors are induced. We have shown that repeated copulation attenuates the sensitization of appetitive sexual behaviors. Here, we assessed which component of male stimulation during copulation is involved in the attenuation. On 8 occasions, sexually experienced OVX Long-Evans rats were treated with 10μgEB and 48h later assigned to one of six groups that differed in their experience on intermediates tests (2-7). One was given repeated access to a male (EB/Male), and another was placed in the copulation chamber alone (EB/Alone) on intermediate tests. Three groups were given one of three somatosensory stimuli by the experimenter: manual flank stimulation (FLS), clitoral stimulation (CLS), or vaginocervical stimulation (VCS). Finally, the control group was left undisturbed in the animal care facility (ACF). Sexual behaviors were measured on Tests 1 and 8. VCS received from the experimenter (VCS) or from the male during copulation (EB/Male) attenuated the magnitude of the sensitization of appetitive sexual behaviors compared with those that were not brought to the testing rooms (ACF), and the effect was most pronounced on sexual solicitations. These results suggest that VCS received during penile intromission inhibits the sensitization of sexually appetitive behaviors by repeated administration of EB. As such, repeated administration of EB may oppose those mechanisms that induce estrous termination, perhaps by sensitizing inhibitory processes within the ventromedial hypothalamus that typically prevent the display of sexual behaviors (i.e., by facilitating disinhibition). Copyright © 2015 Elsevier Inc. All rights reserved.

Imprinted expression in cystic embryoid bodies shows an embryonic and not an extra-embryonic pattern

PubMed Central

Kulinski, Tomasz M.; Casari, M. Rita T.; Guenzl, Philipp M.; Wenzel, Daniel; Andergassen, Daniel; Hladik, Anastasiya; Datlinger, Paul; Farlik, Matthias; Theussl, H. -Christian; Penninger, Josef M.; Knapp, Sylvia; Bock, Christoph; Barlow, Denise P.; Hudson, Quanah J.

2015-01-01

A large subset of mammalian imprinted genes show extra-embryonic lineage (EXEL) specific imprinted expression that is restricted to placental trophectoderm lineages and to visceral yolk sac endoderm (ysE). Isolated ysE provides a homogenous in vivo model of a mid-gestation extra-embryonic tissue to examine the mechanism of EXEL-specific imprinted gene silencing, but an in vitro model of ysE to facilitate more rapid and cost-effective experiments is not available. Reports indicate that ES cells differentiated into cystic embryoid bodies (EBs) contain ysE, so here we investigate if cystic EBs model ysE imprinted expression. The imprinted expression pattern of cystic EBs is shown to resemble fetal liver and not ysE. To investigate the reason for this we characterized the methylome and transcriptome of cystic EBs in comparison to fetal liver and ysE, by whole genome bisulphite sequencing and RNA-seq. Cystic EBs show a fetal liver pattern of global hypermethylation and low expression of repeats, while ysE shows global hypomethylation and high expression of IAPEz retroviral repeats, as reported for placenta. Transcriptome analysis confirmed that cystic EBs are more similar to fetal liver than ysE and express markers of early embryonic endoderm. Genome-wide analysis shows that ysE shares epigenetic and repeat expression features with placenta. Contrary to previous reports, we show that cystic EBs do not contain ysE, but are more similar to the embryonic endoderm of fetal liver. This explains why cystic EBs reproduce the imprinted expression seen in the embryo but not that seen in the ysE. PMID:25912690

Genetic parameter estimation for milk β-hydroxybutyrate and acetone in early lactation and its association with fat to protein ratio and energy balance in Korean Holstein cattle.

PubMed

Ranaraja, Umanthi; Cho, KwangHyun; Park, MiNa; Kim, SiDong; Lee, SeokHyun; Do, ChangHee

2018-06-01

The objective of this study was to estimate the genetic parameters for milk β-hydroxybutyrate (BHBA), acetone (Ac), fat protein ratio (FPR), and energy balance (EB) using milk test day records and investigate the effect of early lactation FPR and EB on milk ketone body concentrations. Total 262,940 test-day records collected from Korea Animal Improvement Association during the period of 2012 to 2016 were used in this study. BHBA and Ac concentrations in milk were measured by Fourier transform infrared spectroscopy (FTIR). FPR values were obtained using test day records of fat and protein percentage. EB was calculated using previously developed equation based on parity, lactation week, and milk composition data. Genetic parameters were estimated by restricted maximum likelihood procedure based on repeatability model using Wombat program. Elevated milk BHBA and Ac concentrations were observed during the early lactation under the negative energy balance. Milk FPR tends to decrease with the decreasing ketone body concentrations. Heritability estimates for milk BHBA, Ac, EB, and FPR ranged from 0.09 to 0.14, 0.23 to 0.31, 0.19 to 0.52, and 0.16 to 0.42 respectively at parity 1, 2, 3, and 4. The overall heritability for BHBA, Ac, EB and FPR were 0.29, 0.32, 0.58, and 0.38 respectively. A common pattern was observed in heritability of EB and FPR along with parities. FPR and EB can be suggested as potential predictors for risk of hyperketonemia. The heritability estimates of milk BHBA, Ac, EB, and FPR indicate that the selective breeding may contribute to maintaining the milk ketone bodies at optimum level during early lactation.

Efficiency of Core Biopsy for BI-RADS-5 Breast Lesions.

PubMed

Wolf, Ronald; Quan, Glenda; Calhoun, Kris; Soot, Laurel; Skokan, Laurie

2008-01-01

Stereotactic biopsy has proven more cost effective for biopsy of lesions associated with moderately suspicious mammograms. Data regarding selection of stereotactic biopsy (CORE) instead of excisional biopsy (EB) as the first diagnostic procedure in patients with nonpalpable breast lesions and highest suspicion breast imaging-reporting and data system (BI-RADS)-5 mammograms are sparse. Records from a regional health system radiology database were screened for mammograms associated with image-guided biopsy. A total of 182 nonpalpable BI-RADS-5 lesions were sampled in 178 patients over 5 years, using CORE or EB. Initial surgical margins, number of surgeries, time from initial procedure to last related surgical procedure, and hospital and professional charges for related admissions were compared using chi-squared, t-test, and Wilcoxon Mann-Whitney tests. A total of 108 CORE and 74 EB were performed as the first diagnostic procedure. Invasive or in situ carcinoma was diagnosed in 156 (86%) of all biopsies, 95 in CORE and 61 in EB groups. Negative margins of the first surgical procedure were more frequent in CORE (n = 70, 74%) versus EB (n = 17, 28%), p < 0.05. Use of CORE was associated with fewer total surgical procedures per lesion (1.29 +/- 0.05 versus 1.8 +/- 0.05, p < 0.05). Time of initial diagnostic procedure to final treatment did not vary significantly according to group (27 +/- 2 days versus 22 +/- 2 days, CORE versus EB). Mean charges including the diagnostic procedure and all subsequent surgeries were not different between CORE and EB groups ($10,500 +/- 300 versus $11,500 +/- 500, p = 0.08). Use of CORE as the first procedure in patients with highly suspicious mammograms is associated with improved pathologic margins and need for fewer surgical procedures than EB, and should be considered the preferred initial diagnostic approach.

Comparison of early morphological and molecular changes induced by 17-alpha-methyltestosterone and estradiol benzoate in the rat ovary.

PubMed

Ferre, Céline; Belluco, Sara; Tinwell, Helen; Bars, Rémi; Benahmed, Mohamed; Rouquie, David; Schorsch, Frédéric

2013-05-01

Repeated exposure to 17-α-methyltestosterone (17MT) and estradiol benzoate (EB) for 28 or 90 days in rats induce similar ovarian atrophy. The objective of the present work was to identify and compare the early effects induced by 17MT and EB on the ovary using molecular and histopathological tools. Female rats were evaluated after 1, 3 or 7 days following an oral exposure by gavage at a daily dose of 600 mg/kg/day for 17MT and 5 mg/kg/day for EB. All animals were found to be acyclic after 3 or 7 days of treatment with 17MT and EB. Histopathological changes were present in the ovary, uterus, vagina and mammary gland after both treatments. Ovarian atrophy known as the long term effect of 17MT and EB was not yet detected after 7 days of treatment. But non regressive corpora lutea and cystic follicles were identically observed in the ovary of 17MT and EB treated females. Both compounds induced a decrease of LH transcripts together with an increase of plasma progesterone and prolactin levels. Differences in the profile of regulation of the aromatase were noted after 1 and 3 days of treatment in 17MT treated animals (upregulated) when compared to EB treated animals (downregulated). In summary, we have shown that despite the different nature of hormonal activity, EB and 17MT induce very early endocrine perturbation which presents several similarities. Our work indicated that the detection of early key hormonal markers in short term studies can help to predict the adverse long term effects on target tissues. Copyright © 2012 Elsevier GmbH. All rights reserved.

Modeling electric bicycle's lane-changing and retrograde behaviors

NASA Astrophysics Data System (ADS)

Tang, Tie-Qiao; Luo, Xiao-Feng; Zhang, Jian; Chen, Liang

2018-01-01

Recently, electric bicycle (EB) has been one important traffic tool due to its own merits. However, EB's motion behaviors (especially at a signalized/non-signalized intersection) are more complex than those of vehicle since it always has lane-changing and retrograde behaviors. In this paper, we propose a model to explore EB's lane-changing and retrograde behaviors on a road with a signalized intersection. The numerical results indicate that the proposed model can qualitatively describe each EB's lane-changing and retrograde behaviors near a signalized intersection, and that lane-changing and retrograde behaviors have prominent impacts on the signalized intersection (i.e., prominent jams and congestions occur). The above results show that EB should be controlled as a vehicle, i.e., lane-changing and retrograde behaviors at a signalized intersection should strictly be prohibited to improve the operational efficiency and traffic safety at the signalized intersection.

Evidence-Based Programs for Older Adults: A Disconnect Between U.S. National Strategy and Local Senior Center Implementation.

PubMed

Bobitt, Julie; Schwingel, Andiara

2017-01-01

While U.S. national policies have been developed to support evidence-based (EB) lifestyle programs for older adults, there has been limited research to determine the extent to which these programs actually reach local communities. This study sought to identify factors that impact the implementation of EB physical activity, nutrition, and chronic disease management programs at regional (Area Agencies on Aging [AAAs]) and community levels (senior Centers [SCs]). Interviews were conducted with directors of four AAAs and 12 SCs to understand their perspectives on EB program implementation. Narratives revealed differences between AAAs and SCs regarding knowledge about EB programs and reasons to promote and adopt these programs. The only agreement occurred when discussing concerns about funding and program inflexibility. Substantial gaps exist between how EB lifestyle programs are promoted and implemented at the regional and community levels.

Micron-Scale Correlations Among Ti, P, Ce, and Y in Hadean Jack Hills Zircons

NASA Astrophysics Data System (ADS)

Hofmann, A. E.; Cavosie, A. J.; Valley, J. W.; Eiler, J. M.

2007-12-01

Detrital zircons and the inclusions found therein are our only mineralogical constraints on geologic events that occurred on the Hadean Earth. These zircons are commonly small (ca. <100 μm in the longest dimension) and preserve micron to sub-micron chemical zonations indicative of a dynamic petrological history. Trace elements within zircon are of particular interest because concentrations and ratios of these elements can provide information regarding chemical and physical conditions during zircon growth. In this study, we analyzed Hadean-age detrital zircons from Archean metasediment in the Jack Hills (Australia) using the Caltech Microanalysis Center Cameca NanoSIMS 50L. Trace elements analyzed included Ti, P, Ce, and Y. Ti- thermometry [1,2,3] can potentially constrain growth and/or re-equilibration temperatures of zircons; P, Ce, and Y are known to enter the zircon lattice by the coupled xenotime-type substitution mechanism: (Y, REE)3+ + P5+ = Zr4+ + Si4+ [5]. The 89Y/28Si ratio was observed to correlate with, and was used as a proxy for, cathodoluminescence (CL) banding. Growth features manifested in CL (e.g., sector, oscillatory zoning) were observed in all zircons analyzed. CL zones vary from <1 μm to several microns in width; therefore, the NanoSIMS---with a beam diameter resolved to ca. 250 nm on the sample surface when operating with an O- primary beam---is uniquely suited for this scale of analysis. Regions displaying CL banding were imaged as 20 x 20 μm areas. All elements were normalized to 28Si; 49Ti/28Si ratios were converted to [Ti] via calibration based on analyses of synthetic, high-Ti zircons (provided by B. Watson) that were independently analyzed on Caltech's JEOL JXA-8200 electron microprobe. We observe three types of relationships between trace element distribution and CL banding in the zircons imaged: 1) strong positive correlations between CL banding, P, Ce, and Ti; 2) subtle positive correlations between CL banding, P, Ce, and Ti; 3) no correlation between minor/trace elements and CL banding. Positive correlations between CL banding, 3+ cations, and [Ti] have previously been reported by Holden et al. [4]. In this study, gradients at least as sharp as a factor of ~3 in [Ti] are observed between adjacent CL bands in the strongly correlated images. These images also have the highest absolute concentrations of trace elements and display both sector and oscillatory zoning in CL. The correlations observed may be due to: temperature-dependent equilibrium partitioning of all trace elements during rapid cycles in growth temperature; episodic diffusion-limited enrichment of incompatible trace elements in the boundary layer melt adjacent to growing crystals; and/or kinetically controlled, non- equilibrium crystal-melt partitioning caused by trace element enrichments in the boundary layer melt surrounding fast-growing grains (e.g., [6]). We will discriminate between these alternatives based on quantitative relationships between relative enrichments of [Ti] and other trace elements. [1]Watson, E.B. & Harrison, T.M. (2005) Science 308, 841-844. [2]Watson, E.B., Wark, D.A., & Thomas, J.B. (2006) CMP 151, 413-433. [3]Ferry, J.M. & Watson, E.B. (2007) CMP 154, 429-437. [4] Holden, P. et al. (2005) Eos Trans. AGU 86 (52) Fall Meet. Suppl., Abstract V41F-1539. [5] Speer, J.A. (1982) Zircon. In Rev. Min. 5 (ed. P.H. Ribbe), 67-112. [6] Watson, E.B. (2004) GCA 68, 1473-1488.

Epoxy Resins in Electron Microscopy

PubMed Central

Finck, Henry

1960-01-01

A method of embedding biological specimens in araldite 502 (Ciba) has been developed for materials available in the United States. Araldite-embedded tissues are suitable for electron microscopy, but the cutting qualities of the resin necessitates more than routine attention during microtomy. The rather high viscosity of araldite 502 also seems to be an unnecessary handicap. The less viscous epoxy epon 812 (Shell) produces specimens with improved cutting qualities, and has several features—low shrinkage and absence of specimen damage during cure, minimal compression of sections, relative absence of electron beam-induced section damage, etc.—which recommends it as a routine embedding material. The hardness of the cured resin can be easily adjusted by several methods to suit the materials embedded in it. Several problems and advantages of working with sections of epoxy resins are also discussed. PMID:13822825

An Evaluation of Empirical Bayes's Estimation of Value-Added Teacher Performance Measures

ERIC Educational Resources Information Center

Guarino, Cassandra M.; Maxfield, Michelle; Reckase, Mark D.; Thompson, Paul N.; Wooldridge, Jeffrey M.

2015-01-01

Empirical Bayes's (EB) estimation has become a popular procedure used to calculate teacher value added, often as a way to make imprecise estimates more reliable. In this article, we review the theory of EB estimation and use simulated and real student achievement data to study the ability of EB estimators to properly rank teachers. We compare the…

Enrichment of cardiac differentiation of mouse embryonic stem cells by optimizing the hanging drop method.

PubMed

Chen, Ming; Lin, Yong-Qing; Xie, Shuang-Lun; Wu, Hong-Fu; Wang, Jing-Feng

2011-04-01

Hanging drop (HD) culture is used to induce differentiation of embryonic stem cells (ESCs) into other cell types including cardiomyocytes. However, the factors affecting cardiac differentiation of ESCs with this method remain incompletely understood. We have investigated the effects of the starting number of ESCs in embryoid bodies (EBs) and the time of EB adherence to gelatin-coated plates on cardiac differentiation: cardiac differentiation was increased in the EBs by a larger number of ESCs and was decreased by plating EBs at day 4 or earlier. These two factors can thus be optimized to enrich the cardiac differentiation in ESCs using the HD method.

Endoscopic Biliary Stenting Versus Percutaneous Transhepatic Biliary Stenting in Advanced Malignant Biliary Obstruction: Cost-effectiveness Analysis.

PubMed

Sun, Xin Rong; Tang, Cheng Wu; Lu, Wen Ming; Xu, Yong Qiang; Feng, Wen Ming; Bao, Yin; Zheng, Yin Yuan

2014-05-01

This study aims to compare the clinical outcomes and costs between endoscopic biliary stenting (EBS) and percutaneous transhepatic biliary stenting (PTBS). We randomly assigned 112 patients with unresectable malignant biliary obstruction 2006 and 2011 to receive EBS or PTBS with self-expandable metal stent (SEMS) as palliative treatment. PTBS was successfully performed in 55 patients who formed the PTBS group (failed in 2 patients). EBS was successfully performed in 52 patients who formed the EBS group (failed in 3 patients). The effectiveness of biliary drainage, hospital stay, complications, cost, survival time and mortality were compared. Patients in PTBS group had shorter hospital stay and lower initial and overall expense than the BBS group (P < 0.05). There was no significant difference in effectiveness of biliary drainage (P = 0.9357) or survival time between two groups (P = 0.6733). Early complications occurred in PTBS group was significantly lower than in EBS group (3/55 vs 11/52, P = 0.0343). Late complications in the EBS group did not differ significantly from PTBS group (7/55 vs 9/52, P = 0.6922). The survival curves in the two groups showed no significant difference (P = 0.5294). Conclusions: 3.

A novel KRT5 mutation associated with generalized severe epidermolysis bullosa simplex in a 2-year-old Chinese boy

PubMed Central

Zhang, Jia; Yan, Ming; Liang, Jianying; Li, Ming; Yao, Zhirong

2016-01-01

Mutations in keratin 5 (KRT5) or KRT14 genes are responsible for the most severe form of epidermolysis bullosa simplex (EBS), which is EBS generalized severe (EBS-gen sev). To date, only four pathogenic mutations (p.Arg165Ser and p.Lys199Asn in KRT5; p.Arg125Cys and p.Arg125His in KRT14) have been reported to be responsible for EBS-gen sev in the Chinese population. In the present study, a 2-year-old Chinese boy was clinically suspected to suffer from EBS, and thus Sanger sequencing was performed in the extracted genomic DNA samples from the patient, his parents and 100 healthy controls. A novel de novo heterozygous missense mutation c.503A>G (p.Glu168Gly) located at the N-terminal end segment of the 1A domain in KRT5 was identified by molecular analysis. In silico analysis tools were used to predict the pathogenicity of the novel missense mutation. A diagnosis of EBS-gen sev was thus confirmed according to the clinical presentations and molecular results. PMID:27882080

Effectiveness of training in evidence-based medicine skills for healthcare professionals: a systematic review.

PubMed

Hecht, Lars; Buhse, Susanne; Meyer, Gabriele

2016-04-04

Basic skills in evidence-based medicine (EbM) are indispensable for healthcare professionals to promote consumer-centred, evidence-based treatment. EbM training courses are complex interventions - a fact that has not been methodologically reflected by previous systematic reviews. This review evaluates the effects of EbM training for healthcare professionals as well as the quality of reporting of such training interventions. We searched PubMed, EMBASE, CINAHL, Cochrane Library, ERIC, Campbell Library and PsycINFO up to 9/2014. Randomised controlled trials, controlled clinical trials as well as before-after trials were included. Authors were contacted in order to obtain missing data. Two independent reviewers extracted data and assessed risk of bias. We reviewed 14.507 articles; n = 61 appeared potentially eligible; n = 13 involving 1,120 participants were included. EbM training shows some impact on knowledge and skills, whereas the impact on practical EbM application remains unclear. Risk of bias of included trials raises uncertainty about the effects. Description of complex interventions was poor. EbM training has some positive effects on knowledge and skills of healthcare professionals. Appropriate methods for development, piloting, evaluation, reporting and implementation of the training should be applied.

Ebselen induces mitochondrial permeability transition because of its interaction with adenine nucleotide translocase.

PubMed

Pavón, Natalia; Correa, Francisco; Buelna-Chontal, Mabel; Hernández-Esquivel, Luz; Chávez, Edmundo

2015-10-15

Mitochondrial permeability transition is a process established through massive Ca(2+) load in addition to an inducer reagent. Ebselen (Ebs), an antioxidant seleno compound, has been introduced as a reagent which inhibits mitochondrial dysfunction induced by permeability transition. Paradoxically enough, it has been shown that Ebs may also be able to induce the opening of the mitochondrial non-selective pores. This study was performed with the purpose of establishing the membrane system involved in Ebs-induced pore opening. Permeability transition was appraised by analyzing the following: i) matrix Ca(2+) release, and mitochondrial swelling, ii) efflux of cytochrome c, and iii) the inhibition of superoxide dismutase. All of these adverse reactions were inhibited by N-ethylmaleimide and cyclosporin A. At concentrations from 5 to 20 μM, we found that Ebs induces non-specific membrane permeability. Remarkably, Ebs blocks the binding of the fluorescent reagent eosin-5-maleimide to the thiol groups of the adenine nucleotide translocase. Based on the above, it is tempting to hypothesize that Ebs induces pore opening through its binding to the ADP/ATP carrier. Copyright © 2015 Elsevier Inc. All rights reserved.

In vitro assessment of the growth and plasma membrane H+ -ATPase inhibitory activity of ebselen and structurally related selenium- and sulfur-containing compounds in Candida albicans.

PubMed

Orie, Natalie N; Warren, Andrew R; Basaric, Jovana; Lau-Cam, Cesar; Piętka-Ottlik, Magdalena; Młochowski, Jacek; Billack, Blase

2017-06-01

Ebselen (EB, compound 1) is an investigational organoselenium compound that reduces fungal growth, in part, through inhibition of the fungal plasma membrane H + -ATPase (Pma1p). In the present study, the growth inhibitory activity of EB and of five structural analogs was assessed in a fluconazole (FLU)-resistant strain of Candida albicans (S2). While none of the compounds were more effective than EB at inhibiting fungal growth (IC 50  ∼ 18 μM), two compounds, compounds 5 and 6, were similar in potency. Medium acidification assays performed with S2 yeast cells revealed that compounds 4 and 6, but not compounds 2, 3, or 5, exerted an inhibitory activity comparable to EB (IC 50  ∼ 14 μM). Using a partially purified Pma1p preparation obtained from S2 yeast cells, EB and all the analogs demonstrated a similar inhibitory activity. Taken together, these results indicate that EB analogs are worth exploring further for use as growth inhibitors of FLU-resistant fungi. © 2017 Wiley Periodicals, Inc.

Differentiating Mouse Embryonic Stem Cells into Embryoid Bodies by Hanging-Drop Cultures.

PubMed

Behringer, Richard; Gertsenstein, Marina; Nagy, Kristina Vintersten; Nagy, Andras

2016-12-01

Embryonic stem (ES) cells can develop into many types of differentiated tissues if they are placed into a differentiating environment. This can occur in vivo when the ES cells are injected into or aggregated with an embryo, or in vitro if their culture conditions are modified to induce differentiation. There are an increasing number of differentiating culture conditions that can bias the differentiation of ES cells into desired cell types. Determining the mechanisms that control ES cell differentiation into therapeutically important cell types is a quickly growing area of research. Knowledge gained from these studies may eventually lead to the use of stem cells to repair specific damaged tissues. Many times ES cell differentiation proceeds through an intermediate stage called the embryoid body (EB). EBs are round structures composed of ES cells that have undergone some of the initial stages of differentiation. EBs can then be manipulated further to generate more specific cell types. This protocol describes a method to differentiate ES cells into EBs. It produces EBs of comparable size. This aspect is important because the differentiation processes taking place inside an EB are influenced by its size. © 2016 Cold Spring Harbor Laboratory Press.

Distribution and permeability of capillaries at the skin of the conception vessel and the governor vessel in healthy rabbits.

PubMed

Zhou, Dan; Guo, Yi; Guo, Yong-Ming; Zhang, Sai; Pan, Ping

2011-12-01

To investigate the distribution and permeability of blood vessels on the Conception Vessel and the Governor Vessel in the physiological state. Evans blue (EB) solution was injected into the marginal ear vein of healthy rabbits. Three hours after injection, the rabbits were sacrificed and the skin on the Conception Vessel and the Governor Vessel and the corresponding bilateral non-channels was collected. EB was extracted with 7:3 acetone: physiological saline, and the absorbance of EB at each skin tissue was measured with a spectrophotometer. The A value of EB absorbance at the Conception Vessel on the abdominal skin was lower than that of the corresponding bilateral non-channels with a statistically significant difference (P< 0.01). The A value of EB absorbance at the Governor Vessel on the back was higher than that of the corresponding bilateral non-channels (P < 0.05). There was no statistical difference in the A value of EB absorbance between the bilateral non-channels of the abdomen and the back (P > 0.05). There were differences in capillary distribution and permeability between the Conception Vessel, the Governor Vessel and the corresponding bilateral non-meridians.

Evaluation of different methods to detect microbial hygiene indicators relevant in the dairy industry.

PubMed

Hervert, C J; Alles, A S; Martin, N H; Boor, K J; Wiedmann, M

2016-09-01

It is estimated that 19% of the total food loss from retail, food service, and households comes from dairy products. A portion of this loss may be attributed to premature spoilage of products due to lapses in sanitation and postpasteurization contamination at the processing level. Bacterial groups including coliforms, Enterobacteriaceae (EB), and total gram-negative organisms represent indicators of poor sanitation or postpasteurization contamination in dairy products worldwide. Although Petrifilms (3M, St. Paul, MN) and traditional selective media are commonly used for the testing of these indicator organism groups throughout the US dairy industry, new rapid methods are also being developed. This project was designed to evaluate the ability of different methods to detect coliforms, EB, and other gram-negative organisms isolated from various dairy products and dairy processing environments. Using the Food Microbe Tracker database, a collection of 211 coliform, EB, and gram-negative bacterial isolates representing 25 genera associated with dairy products was assembled for this study. We tested the selected isolates in pure culture (at levels of approximately 15 to 300 cells/test) to evaluate the ability of 3M Coliform Petrifilm to detect coliforms, 3M Enterobacteriaceae Petrifilm, violet red bile glucose agar, and an alternative flow cytometry-based method (bioMérieux D-Count, Marcy-l'Étoile, France) to detect EB, and crystal violet tetrazolium agar to detect total gram-negative organisms. Of the 211 gram-negative isolates tested, 82% (174/211) had characteristic growth on crystal violet tetrazolium agar. Within this set of 211 gram-negative organisms, 175 isolates representing 19 EB genera were screened for detection using EB selective/differential testing methods. We observed positive results for 96% (168/175), 90% (158/175), and 86% (151/175) of EB isolates when tested on EB Petrifilm, violet red bile glucose agar, and D-Count, respectively; optimization of the cut-off thresholds for the D-Count may further improve its sensitivity and specificity, but will require additional data and may vary in food matrices. Additionally, 74% (129/175) of the EB isolates tested positive as coliforms. The data obtained from this study identify differences in detection between 5 microbial hygiene indicator tests and highlight the benefits of EB and total gram-negative testing methods. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Direct write electron beam lithography: a historical overview

NASA Astrophysics Data System (ADS)

Pfeiffer, Hans C.

2010-09-01

Maskless pattern generation capability in combination with practically limitless resolution made probe-forming electron beam systems attractive tools in the semiconductor fabrication process. However, serial exposure of pattern elements with a scanning beam is a slow process and throughput presented a key challenge in electron beam lithography from the beginning. To meet this challenge imaging concepts with increasing exposure efficiency have been developed projecting ever larger number of pixels in parallel. This evolution started in the 1960s with the SEM-type Gaussian beam systems writing one pixel at a time directly on wafers. During the 1970s IBM pioneered the concept of shaped beams containing multiple pixels which led to higher throughput and an early success of e-beam direct write (EBDW) in large scale manufacturing of semiconductor chips. EBDW in a mix-and match approach with optical lithography provided unique flexibility in part number management and cycle time reduction and proved extremely cost effective in IBM's Quick-Turn-Around-Time (QTAT) facilities. But shaped beams did not keep pace with Moore's law because of limitations imposed by the physics of charged particles: Coulomb interactions between beam electrons cause image blur and consequently limit beam current and throughput. A new technology approach was needed. Physically separating beam electrons into multiple beamlets to reduce Coulomb interaction led to the development of massively parallel projection of pixels. Electron projection lithography (EPL) - a mask based imaging technique emulating optical steppers - was pursued during the 1990s by Bell Labs with SCALPEL and by IBM with PREVAIL in partnership with Nikon. In 2003 Nikon shipped the first NCR-EB1A e-beam stepper based on the PREVAIL technology to Selete. It exposed pattern segments containing 10 million pixels in single shot and represented the first successful demonstration of massively parallel pixel projection. However the window of opportunity for EPL had closed with the quick implementation of immersion lithography and the interest of the industry has since shifted back to maskless lithography (ML2). This historical overview of EBDW will highlight opportunities and limitation of the technology with particular focus on technical challenges facing the current ML2 development efforts in Europe and the US. A brief status report and risk assessment of the ML2 approaches will be provided.

[Chromogranin A derived peptide CGA47-66 inhibits hyper-permeability of blood brain barrier in mice with sepsis].

PubMed

Zeng, Yan; Zhang, Dan; Jiang, Liping; Wei, Fu; Xu, Shan

2016-02-01

To explore the effect of chromofungin (CHR), a chromogranin A (CGA) derived peptide CGA47-66, on hyper-permeability of blood brain barrier in septic mice. 120 healthy male C57BL/6 mice were randomly divided into groups, with 12 mice in each group. Seventy-two mice were used for dynamic observation of the contents of water and Evan blue (EB) in brain tissue after being treated with lipopolysaccharide (LPS). Another 48 mice were divided into normal saline control group (NS group), LPS induced sepsis model group (LPS group), low-dose CHR pretreatment group (CL+LPS group), and high-dose CHR pretreatment group (CH+LPS group). The septic model was reproduced by intraperitoneal injection of 10 mg/kg LPS 0.1 mL, and the mice in NS group was given equal volume of normal saline. The mice in CL+LPS group and CH+LPS group were intraperitoneally injected with 15.5 μg/kg and 77.5 μg/kg CHR 10 minutes before LPS injection. Six hours after LPS injection, 4 mL/kg of 2% EB was injected via caudal vein, the contents of water and EB in brain tissue were determined, and EB immune fluorescence in brain tissue was determined to assess the changes in permeability of blood brain barrier. Brain pathology was observed with hematoxylin and eosin (HE) staining. With the extension of time after LPS injection, the contents of water and EB in brain tissue were gradually increased, and the time of difference with statistical significance appeared earlier when compared with that of control group in the contents of water than that in EB contents (3 hours and 6 hours, respectively). The contents of water and EB in brain tissue in LPS group were significantly increased as compared with NS group [water content: (79.77±0.62)% vs. (78.28±0.44)%, P < 0.01; EB content (μg/g): 13.87±4.50 vs. 7.13±1.76, P < 0.05]. CHR pretreatment with either of two dosages could reverse the increase in water and EB contents in brain tissue induced by LPS, and the effect was more significant in CH+LPS group [water content: (78.15±0.73)% vs. (79.77±0.62)%, EB (μg/g): 7.09±2.59 vs. 13.87±4.50, both P < 0.05]. It was shown by EB fluorescence observation that the fluorescence signal displayed only in the meninges in NS group, and EB fluorescence was widely distributed in brain parenchyma in LPS group, indicating that the EB leakage in LPS group was more marked than that of NS group. In CHR pretreatment groups, EB fluorescence was decreased in brain parenchyma, indicating that EB leakage was significantly less marked, while it was more obvious in high dose CHR group. It was shown by HE staining that cerebral blood vessel structure was intact in NS group, and the gap around blood vessel was not significant increased. On the other hand, brain structure in LPS group appeared loose, with widening of small perivascular spaces and obvious edema. Brain edema in CHR pretreatment groups was improved as compared with that of the LPS group, and it was more apparent in high dose CHR group. LPS induced change in blood brain barrier permeability in mice in a time-dependent manner. Exogenous CGA derived peptides CHR can inhibit LPS induced hyper-permeability of blood brain barrier in septic mice, thus reduces brain edema, protects the brain tissue, and the effect is more obvious with a high dose of CHR (77.5 μg/kg).

Fgf3 and Fgf10a work in concert to promote maturation of the epibranchial placodes in zebrafish.

PubMed

McCarroll, Matthew N; Nechiporuk, Alex V

2013-01-01

Essential cellular components of the paired sensory organs of the vertebrate head are derived from transient thickenings of embryonic ectoderm known as cranial placodes. The epibranchial (EB) placodes give rise to sensory neurons of the EB ganglia that are responsible for relaying visceral sensations form the periphery to the central nervous system. Development of EB placodes and subsequent formation of EB ganglia is a multistep process regulated by various extrinsic factors, including fibroblast growth factors (Fgfs). We discovered that two Fgf ligands, Fgf3 and Fgf10a, cooperate to promote EB placode development. Whereas EB placodes are induced in the absence of Fgf3 and Fgf10a, they fail to express placode specific markers Pax2a and Sox3. Expression analysis and mosaic rescue experiments demonstrate that Fgf3 signal is derived from the endoderm, whereas Fgf10a is emitted from the lateral line system and the otic placode. Further analyses revealed that Fgf3 and Fgf10a activities are not required for cell proliferation or survival, but are required for placodal cells to undergo neurogenesis. Based on these data, we conclude that a combined loss of these Fgf factors results in a failure of the EB placode precursors to initiate a transcriptional program needed for maturation and subsequent neurogenesis. These findings highlight the importance and complexity of reiterated Fgf signaling during cranial placode formation and subsequent sensory organ development.

Fgf3 and Fgf10a Work in Concert to Promote Maturation of the Epibranchial Placodes in Zebrafish

PubMed Central

McCarroll, Matthew N.; Nechiporuk, Alex V.

2013-01-01

Essential cellular components of the paired sensory organs of the vertebrate head are derived from transient thickenings of embryonic ectoderm known as cranial placodes. The epibranchial (EB) placodes give rise to sensory neurons of the EB ganglia that are responsible for relaying visceral sensations form the periphery to the central nervous system. Development of EB placodes and subsequent formation of EB ganglia is a multistep process regulated by various extrinsic factors, including fibroblast growth factors (Fgfs). We discovered that two Fgf ligands, Fgf3 and Fgf10a, cooperate to promote EB placode development. Whereas EB placodes are induced in the absence of Fgf3 and Fgf10a, they fail to express placode specific markers Pax2a and Sox3. Expression analysis and mosaic rescue experiments demonstrate that Fgf3 signal is derived from the endoderm, whereas Fgf10a is emitted from the lateral line system and the otic placode. Further analyses revealed that Fgf3 and Fgf10a activities are not required for cell proliferation or survival, but are required for placodal cells to undergo neurogenesis. Based on these data, we conclude that a combined loss of these Fgf factors results in a failure of the EB placode precursors to initiate a transcriptional program needed for maturation and subsequent neurogenesis. These findings highlight the importance and complexity of reiterated Fgf signaling during cranial placode formation and subsequent sensory organ development. PMID:24358375

Protective effects of ebselen (Ebs) and para-aminosalicylic acid (PAS) against manganese (Mn)-induced neurotoxicity

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

Marreilha dos Santos, A.P., E-mail: apsantos@ff.ul.pt; Lucas, Rui L.; Andrade, Vanda

2012-02-01

Chronic, excessive exposure to manganese (Mn) may induce neurotoxicity and cause an irreversible brain disease, referred to as manganism. Efficacious therapies for the treatment of Mn are lacking, mandating the development of new interventions. The purpose of the present study was to investigate the efficacy of ebselen (Ebs) and para-aminosalicylic acid (PAS) in attenuating the neurotoxic effects of Mn in an in vivo rat model. Exposure biomarkers, inflammatory and oxidative stress biomarkers, as well as behavioral parameters were evaluated. Co-treatment with Mn plus Ebs or Mn plus PAS caused a significant decrease in blood and brain Mn concentrations (compared tomore » rats treated with Mn alone), concomitant with reduced brain E{sub 2} prostaglandin (PGE{sub 2}) and enhanced brain glutathione (GSH) levels, decreased serum prolactin (PRL) levels, and increased ambulation and rearing activities. Taken together, these results establish that both PAS and Ebs are efficacious in reducing Mn body burden, neuroinflammation, oxidative stress and locomotor activity impairments in a rat model of Mn-induced toxicity. -- Highlights: ► The manuscript is unique in its approach to the neurotoxicity of Mn. ► The manuscript incorporates molecular, cellular and functional (behavioral) analyses. ► Both PAS and Ebs are effective in restoring Mn behavioral function. ► Both PAS and Ebs are effective in reducing Mn-induced oxidative stress. ► Both PAS and Ebs led to a decrease in Mn-induced neuro-inflammation.« less

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

Caporuscio, Florie Andre; Norskog, Katherine Elizabeth; Maner, James

Over the past five years the Used Fuel Campaign has investigated Engineered Barrier Systems (EBS) at higher heat loads (up to 300°C) and pressure (150 bar). This past year experimental work was hindered due to a revamping of the hydrothermal lab. Regardless, two experiments were run this past year, EBS-18 and EBS-19. EBS-18 was run using Low Carbon Steel (LCS) and opalinus clay in addition to the bentonite and opalinus brine. Many of the past results were confirmed in EBS-18, such as the restriction of illite formation due to the bulk chemistry, pyrite degradation, and zeolite formation dependent on themore » bentonite and opalinus clay. The LCS show vast amounts of pit corrosion (over 100μm of corrosion in six weeks), leading a corrosion rate of 1083 μm/year. In addition, a mineral goethite, an iron-bearing hydroxide, formed in the pits of the LCS. Preliminary results from EBS-19 water chemistry are included but SEM imaging, micro probe and XRD are still needed for further results. Copper corrosion was investigated further and over 850 measurements were taken. It was concluded that pitting and pyrite degradation drastically increase the corrosion rate from 0.12 to 0.39 μm/day. However, the growth of a layer of the mineral chalcocite is thought to subdue the corrosion rate to 0.024 μm/day as observed in the EBS-13, a sixth month experiment. This document presents the findings of this past year.« less

Ultrastructural characteristics of three undifferentiated mouse embryonic stem cell lines and their differentiated three-dimensional derivatives: a comparative study.

PubMed

Alharbi, Suzan; Elsafadi, Mona; Mobarak, Mohammed; Alrwili, Ali; Vishnubalaji, Radhakrishnan; Manikandan, Muthurangan; Al-Qudsi, Fatma; Karim, Saleh; Al-Nabaheen, May; Aldahmash, Abdullah; Mahmood, Amer

2014-04-01

The fine structures of mouse embryonic stem cells (mESCs) grown as colonies and differentiated in three-dimensional (3D) culture as embryoid bodies (EBs) were analyzed by transmission electron microscopy. Undifferentiated mESCs expressed markers that proved their pluripotency. Differentiated EBs expressed different differentiation marker proteins from the three germ layers. The ultrastructure of mESCs revealed the presence of microvilli on the cell surfaces, large and deep infolded nuclei, low cytoplasm-to-nuclear ratios, frequent lipid droplets, nonprominent Golgi apparatus, and smooth endoplasmic reticulum. In addition, we found prominent juvenile mitochondria and free ribosomes-rich cytoplasm in mESCs. Ultrastructure of the differentiated mESCs as EBs showed different cell arrangements, which indicate the different stages of EB development and differentiation. The morphologies of BALB/c and 129 W9.5 EBs were very similar at day 4, whereas C57BL/6 EBs were distinct from the others at day 4. This finding suggested that differentiation of EBs from different cell lines occurs in the same pattern but not at the same rate. Conversely, the ultrastructure results of BALB/c and 129 W9.5 ESCs revealed differentiating features, such as the dilated profile of a rough endoplasmic reticulum. In addition, we found low expression levels of undifferentiated markers on the outer cells of BALB/c and 129 W9.5 mESC colonies, which suggests a faster differentiation potential.

The microtubule associated protein END BINDING 1 represses root responses to mechanical cues.

PubMed

Gleeson, Laura; Squires, Shannon; Bisgrove, Sherryl R

2012-05-01

The ability of roots to navigate around rocks and other debris as they grow through the soil requires a mechanism for detecting and responding to input from both touch and gravity sensing systems. The microtubule associated protein END BINDING 1b (EB1b) is involved in this process as mutants have defects responding to combinations of touch and gravity cues. This study investigates the role of EB1b in root responses to mechanical cues. We find that eb1b-1 mutant roots exhibit an increase over wild type in their response to touch and that the expression of EB1b genes in transgenic mutants restores the response to wild type levels, indicating that EB1b is an inhibitor of the response. Mutant roots are also hypersensitive to increased levels of mechanical stimulation, revealing the presence of another process that activates the response. These findings are supported by analyses of double mutants between eb1b-1 and seedlings carrying mutations in PHOSPHOGLUCOMUTASE (PGM), ALTERED RESPONSE TO GRAVITY1 (ARG1), or TOUCH3 (TCH3), genes that encode proteins involved in gravity sensing, signaling, or touch responses, respectively. A model is proposed in which root responses to mechanical cues are modulated by at least two competing regulatory processes, one that promotes touch-mediated growth and another, regulated by EB1b, which dampens root responses to touch and enhances gravitropism. © 2012. Published by Elsevier Ireland Ltd. All rights reserved.

Generating size-controlled embryoid bodies using laser direct-write.

PubMed

Dias, A D; Unser, A M; Xie, Y; Chrisey, D B; Corr, D T

2014-06-01

Embryonic stem cells (ESCs) have the potential to self-renew and differentiate into any specialized cell type. One common method to differentiate ESCs in vitro is through embryoid bodies (EBs), three-dimensional cellular aggregates that spontaneously self-assemble and generally express markers for the three germ layers, endoderm, ectoderm, and mesoderm. It has been previously shown that both EB size and 2D colony size each influence differentiation. We hypothesized that we could control the size of the EB formed by mouse ESCs (mESCs) by using a cell printing method, laser direct-write (LDW), to control both the size of the initial printed colony and the local cell density in printed colonies. After printing mESCs at various printed colony sizes and printing densities, two-way ANOVAs indicated that the EB diameter was influenced by printing density after three days (p = 0.0002), while there was no effect of the printed colony diameter on the EB diameter at the same timepoint (p = 0.74). There was no significant interaction between these two factors. Tukey's honestly significant difference test showed that high-density colonies formed significantly larger EBs, suggesting that printed mESCs quickly aggregate with nearby cells. Thus, EBs can be engineered to a desired size by controlling printing density, which will influence the design of future differentiation studies. Herein, we highlight the capacity of LDW to control the local cell density and colony size independently, at prescribed spatial locations, potentially leading to better stem cell maintenance and directed differentiation.

Experimental evidence of ion-induced instabilities in the NSLS-II storage ring

DOE PAGES

Cheng, Weixing; Li, Yongjun; Podobedov, Boris

2017-03-12

Fast ion instability has been identified as one of the most prominent instabilities in the recently constructed NSLS-II storage ring at Brookhaven National Laboratory. At a relatively low beam current (~ 25 mA) multi-bunch fills, ion-induced instabilities have already been observed during the early stages of machine commissioning. At present user operation with 250 mA in ~1000 bunches, the fast ion still remains the dominant instability, even after months of vacuum conditioning at high current. Ion-induced dipole motions of the electron beam have been suppressed using the transverse bunch-by-bunch (BxB) feedback system. However other adverse effects of this instability, suchmore » as the vertical beam size increase along the bunch train cannot be cured by the feedback system. Therefore, to achieve the NSLS-II design current of 500 mA while maintaining a small vertical beam emittance, it is important to further understand the fast ion instability and develop mitigation techniques. This paper reports on a series of ion-instability observations at various fill patterns and beam currents using start-of-art NSLS-II diagnostic tools.« less

Experimental evidence of ion-induced instabilities in the NSLS-II storage ring

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

Cheng, Weixing; Li, Yongjun; Podobedov, Boris

Fast ion instability has been identified as one of the most prominent instabilities in the recently constructed NSLS-II storage ring at Brookhaven National Laboratory. At a relatively low beam current (~ 25 mA) multi-bunch fills, ion-induced instabilities have already been observed during the early stages of machine commissioning. At present user operation with 250 mA in ~1000 bunches, the fast ion still remains the dominant instability, even after months of vacuum conditioning at high current. Ion-induced dipole motions of the electron beam have been suppressed using the transverse bunch-by-bunch (BxB) feedback system. However other adverse effects of this instability, suchmore » as the vertical beam size increase along the bunch train cannot be cured by the feedback system. Therefore, to achieve the NSLS-II design current of 500 mA while maintaining a small vertical beam emittance, it is important to further understand the fast ion instability and develop mitigation techniques. This paper reports on a series of ion-instability observations at various fill patterns and beam currents using start-of-art NSLS-II diagnostic tools.« less

76 FR 73684 - Notice of a Change in Status of an Extended Benefit (EB) Period for New York and Maryland

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-29

... the last notice regarding the States EB status: Based on the data released by the Bureau of Labor Statistics on September 16, 2011, the seasonally-adjusted total unemployment rate for New York rose to meet... began October 2. The trigger notice covering state eligibility for the EB program can be found at: http...

Pain care for patients with epidermolysis bullosa: best care practice guidelines.

PubMed

Goldschneider, Kenneth R; Good, Julie; Harrop, Emily; Liossi, Christina; Lynch-Jordan, Anne; Martinez, Anna E; Maxwell, Lynne G; Stanko-Lopp, Danette

2014-10-09

Inherited epidermolysis bullosa (EB) comprises a group of rare disorders that have multi-system effects and patients present with a number of both acute and chronic pain care needs. Effects on quality of life are substantial. Pain and itching are burdensome daily problems. Experience with, and knowledge of, the best pain and itch care for these patients is minimal. Evidence-based best care practice guidelines are needed to establish a base of knowledge and practice for practitioners of many disciplines to improve the quality of life for both adult and pediatric patients with EB. The process was begun at the request of Dystrophic Epidermolysis Bullosa Research Association International (DEBRA International), an organization dedicated to improvement of care, research and dissemination of knowledge for EB patients worldwide. An international panel of experts in pain and palliative care who have extensive experience caring for patients with EB was assembled. Literature was reviewed and systematically evaluated. For areas of care without direct evidence, clinically relevant literature was assessed, and rounds of consensus building were conducted. The process involved a face-to-face consensus meeting that involved a family representative and methodologist, as well as the panel of clinical experts. During development, EB family input was obtained and the document was reviewed by a wide variety of experts representing several disciplines related to the care of patients with EB. The first evidence-based care guidelines for the care of pain in EB were produced. The guidelines are clinically relevant for care of patients of all subtypes and ages, and apply to practitioners of all disciplines involved in the care of patients with EB. When the evidence suggests that the diagnosis or treatment of painful conditions differs between adults and children, it will be so noted. Evidence-based care guidelines are a means of standardizing optimal care for EB patients, whose disease is often times horrific in its effects on quality of life, and whose care is resource-intensive and difficult. The guideline development process also highlighted areas for research in order to improve further the evidence base for future care.

Distinct associations between energy balance and the sleep characteristics slow wave sleep and rapid eye movement sleep.

PubMed

Rutters, F; Gonnissen, H K; Hursel, R; Lemmens, S G; Martens, E A; Westerterp-Plantenga, M S

2012-10-01

Epidemiologically, an inverse relationship between body mass index (BMI) and sleep duration is observed. Intra-individual variance in the amount of slow wave sleep (SWS) or rapid eye movement (REM) sleep has been related to variance of metabolic and endocrine parameters, which are risk factors for the disturbance of energy balance (EB). To investigate inter-individual relationships between EB (EB= energy intake-energy expenditure∣, MJ/24 h), SWS or REM sleep, and relevant parameters in normal-weight men during two 48 h stays in the controlled environment of a respiration chamber. A total of 16 men (age 23±3.7 years, BMI 23.9±1.9 kg m(-2)) stayed in the respiration chamber twice for 48 h to assure EB. Electroencephalography was used to monitor sleep (2330-0730 hrs). Hunger and fullness were scored by visual analog scales; mood was determined by State Trait Anxiety Index-state and food reward by liking and wanting. Baseline blood and salivary samples were collected before breakfast. Subjects were fed in EB, except for the last dinner, when energy intake was ad libitum. The subjects slept on average 441.8±49 min per night, and showed high within-subject reliability for the amount of SWS and REM sleep. Linear regression analyses showed that EB was inversely related to the amount of SWS (r=-0.43, P<0.03), and positively related to the amount of REM sleep (r=0.40, P<0.05). Relevant parameters such as hunger, reward, stress and orexigenic hormone concentrations were related to overeating, as well as to the amount of SWS and REM sleep, however, after inclusion of these parameters in a multiple regression, the amount of SWS and REM sleep did not add to the explained variance of EB, which suggests that due to their individual associations, these EB parameters are mediator variables. A positive EB due to overeating, was explained by a smaller amount of SWS and higher amount of REM sleep, mediated by hunger, fullness, State Trait Anxiety Index-state scores, glucose/insulin ratio, and ghrelin and cortisol concentrations.

Photometric Follow-up of Eclipsing Binary Candidates from KELT and Kepler

NASA Astrophysics Data System (ADS)

Garcia Soto, Aylin; Rodriguez, Joseph E.; Bieryla, Allyson; KELT survey

2018-01-01

Eclipsing binaries (EBs) are incredibly valuable, as they provide the opportunity to precisely measure fundamental stellar parameters without the need for stellar models. Therefore, we can use EBs to directly test stellar evolution models. Constraining the stellar properties of stars is important since they directly influence our understanding of any planets orbiting them. Using the Harvard University's Clay 0.4m telescope and Fred Lawrence Whipple Observatory’s 1.2m telescope on Mount Hopkins, Arizona, we conducted follow-up multi-band photometric observations of EB candidates from the Kilodegree Extremely Little Telescope (KELT) survey and the Kepler mission. We will present our follow-up observations and AstroImageJ analysis on these 5 EB systems.

Clinical Ion Beam Applications: Basic Properties, Application, Quality Control, Planning

NASA Astrophysics Data System (ADS)

Kraft, Gerhard

2009-03-01

Heavy-ion therapy using beam scanning and biological dose optimization is a novel technique of high-precision external radiotherapy. It yields a better perspective for tumor cure of radio-resistant tumors. However, heavy-ion therapy is not a general solution for all types of tumors. As compared to conventional radiotherapy, heavy-ion radiotherapy has the advantages of higher tumor dose, improved sparing of normal tissue in the entrance channel, a more precise concentration of the dose in the target volume with steeper gradients to the normal tissue, and a higher radiobiological effectiveness for tumors which are radio-resistant in conventional therapy. These properties make it possible to treat radio-resistant tumors with great success, including those in close vicinity to critical organs.

Hydro-Thermal Fatigue Resistance Measurements on Polymer Interfaces

NASA Astrophysics Data System (ADS)

Gurumurthy, Charan K.; Kramer, Edward J.; Hui, Chung-Yuen

1998-03-01

We have developed a new technique based on a fiber optic displacement sensor for rapid determination of hydro-thermal fatigue crack growth rate per cycle (da/dN) of an epoxy/polyimide interface used in flip chip attach microelectronic assembly. The sample is prepared as a trilayered cantilever beam by capillary flow of the epoxy underfill over a polyimide coated metallic beam. During hydro-thermal cycling the crack growth along the interface (from the free end) changes the displacement of this end of the beam and we measure the free end displacement at the lowest temperature in each hydro-thermal cycle. The change in beam displacement is then converted into crack growth rate (da/dN). da/dN depends on the maximum change in the strain energy release rate of the crack and the phase angle in each cycle. The relation between da/dN and maximum strain energy release rate characterizes the fatigue crack growth resistance of the interface. We have developed and used a simple model anhydride cured and a commercially available PMDA/ODA passivation for this study.

Phosphorescent quantum dots/ethidium bromide nanohybrids based on photoinduced electron transfer for DNA detection.

PubMed

Bi, Lin; Yu, Yuan-Hua

2015-04-05

Mercaptopropionic acid-capped Mn-doped ZnS quantum dots/ethidium bromide (EB) nanohybrids were constructed for photoinduced electron transfer (PIET) and then used as a room-temperature phosphorescence (RTP) probe for DNA detection. EB could quench the RTP of Mn-doped ZnS QDs by PIET, thereby forming Mn-doped ZnS QDs/EB nanohybrids and storing RTP. Meanwhile, EB could be inserted into DNA and EB could be competitively desorbed from the surface of Mn-doped ZnS QDs by DNA, thereby releasing the RTP of Mn-doped ZnS QDs. Based on this mechanism, a RTP sensor for DNA detection was developed. Under optimal conditions, the detection limit for DNA was 0.045 mg L(-1), the relative standard deviation was 1.7%, and the method linear ranged from 0.2 to 20 mg L(-1). The proposed method was applied to biological fluids, in which satisfactory results were obtained. Copyright © 2015 Elsevier B.V. All rights reserved.

Perioperative care of patients with epidermolysis bullosa: proceedings of the 5th international symposium on epidermolysis bullosa, Santiago Chile, December 4-6, 2008.

PubMed

Goldschneider, Kenneth; Lucky, Anne W; Mellerio, Jemima E; Palisson, Francis; del Carmen Viñuela Miranda, Maria; Azizkhan, Richard G

2010-09-01

Epidermolysis bullosa (EB) has become recognized as a multisystem disorder that poses a number of pre-, intra-, and postoperative challenges. While anesthesiologists have long appreciated the potential difficult intubation in patients with EB, other systems can be affected by this disorder. Hematologic, cardiac, skeletal, gastrointestinal, nutritional, and metabolic deficiencies are foci of preoperative medical care, in addition to the airway concerns. Therefore, multidisciplinary planning for operative care is imperative. A multinational, interdisciplinary panel of experts assembled in Santiagio, Chile to review the best practices for perioperative care of patients with EB. This paper presents guidelines that represent a synthesis of evidence-based approaches and the expert consensus of this panel and are intended to aid physicians new to caring for patients with EB when operative management is indicated. With proper medical optimization and attention to detail in the operating room, patients with EB can have an uneventful perioperative course.

Characterization of electrolyte-binder mixes for use in thermal batteries

NASA Astrophysics Data System (ADS)

Guidotti, R. A.; Reinhardt, F. W.

1991-03-01

A number of metal oxides were evaluated for their ability to immobilize molten LiCl-KCl eutectic in electrolyte-binder (EB) mixes used in thermally activated batteries. These metal oxides included fumed silicas, alumina, and a titania (all prepared by steam hydrolysis of the halides), floated silicas, MgO, and an alumina molecular sieve. The characteristics of the EB powders that were used as metrics were flow properties, homogeneity, BET surface area, particle-size distribution, and moisture content. The characteristics of EB pellets used as metrics were deformation at 530 C under an applied pressure and tendency for electrolyte leakage at 400 C. Many of the same characterization techniques used for EB powders were applied to the LiCl-KCl eutectic, its component halides, and the metal oxides as well. The reproducibility of the properties of several of the standard Sandia EB mixes was evaluated for materials prepared at a number of thermal-battery manufacturing facilities following the same processing procedures.

Neuronal populations in the occipital cortex of the blind synchronize to the temporal dynamics of speech

PubMed Central

Van Ackeren, Markus Johannes; Barbero, Francesca M; Mattioni, Stefania; Bottini, Roberto

2018-01-01

The occipital cortex of early blind individuals (EB) activates during speech processing, challenging the notion of a hard-wired neurobiology of language. But, at what stage of speech processing do occipital regions participate in EB? Here we demonstrate that parieto-occipital regions in EB enhance their synchronization to acoustic fluctuations in human speech in the theta-range (corresponding to syllabic rate), irrespective of speech intelligibility. Crucially, enhanced synchronization to the intelligibility of speech was selectively observed in primary visual cortex in EB, suggesting that this region is at the interface between speech perception and comprehension. Moreover, EB showed overall enhanced functional connectivity between temporal and occipital cortices that are sensitive to speech intelligibility and altered directionality when compared to the sighted group. These findings suggest that the occipital cortex of the blind adopts an architecture that allows the tracking of speech material, and therefore does not fully abstract from the reorganized sensory inputs it receives. PMID:29338838

Venetoclax Synergizes with Radiotherapy for Treatment of B-cell Lymphomas.

PubMed

O'Steen, Shyril; Green, Damian J; Gopal, Ajay K; Orozco, Johnnie J; Kenoyer, Aimee L; Lin, Yukang; Wilbur, D Scott; Hamlin, Donald K; Fisher, Darrell R; Hylarides, Mark D; Gooley, Theodore A; Waltman, Amelia; Till, Brian G; Press, Oliver W

2017-07-15

Constitutive B-cell receptor signaling leads to overexpression of the antiapoptotic BCL-2 protein and is implicated in the pathogenesis of many types of B-cell non-Hodgkin lymphoma (B-NHL). The BCL-2 small-molecule inhibitor venetoclax shows promising clinical response rates in several lymphomas, but is not curative as monotherapy. Radiotherapy is a rational candidate for combining with BCL-2 inhibition, as DNA damage caused by radiotherapy increases the activity of pro-apoptotic BCL-2 pathway proteins, and lymphomas are exquisitely sensitive to radiation. We tested B-NHL responses to venetoclax combined with either external beam radiotherapy or radioimmunotherapy (RIT), which joins the selectivity of antibody targeting with the effectiveness of irradiation. We first tested cytotoxicity of cesium-137 irradiation plus venetoclax in 14 B-NHL cell lines representing five lymphoma subtypes. Combination treatment synergistically increased cell death in 10 of 14 lines. Lack of synergy was predicted by resistance to single-agent venetoclax and high BCL-XL expression. We then assessed the efficacy of external beam radiotherapy plus venetoclax in murine xenograft models of mantle cell (MCL), germinal-center diffuse large B-cell (GCB-DLBCL), and activated B-cell (ABC-DLBCL) lymphomas. In each model, external beam radiotherapy plus venetoclax synergistically increased mouse survival time, curing up to 10%. We finally combined venetoclax treatment of MCL and ABC-DLBCL xenografts with a pretargeted RIT (PRIT) system directed against the CD20 antigen. Optimal dosing of PRIT plus venetoclax cured 100% of mice with no detectable toxicity. Venetoclax combined with radiotherapy may be a promising treatment for a wide range of lymphomas Cancer Res; 77(14); 3885-93. ©2017 AACR . ©2017 American Association for Cancer Research.

An Evaluation of Empirical Bayes' Estimation of Value- Added Teacher Performance Measures. Working Paper #31. Revised

ERIC Educational Resources Information Center

Guarino, Cassandra M.; Maxfield, Michelle; Reckase, Mark D.; Thompson, Paul; Wooldridge, Jeffrey M.

2014-01-01

Empirical Bayes' (EB) estimation is a widely used procedure to calculate teacher value-added. It is primarily viewed as a way to make imprecise estimates more reliable. In this paper we review the theory of EB estimation and use simulated data to study its ability to properly rank teachers. We compare the performance of EB estimators with that of…

The influence of double-credit evidence-based continuing medical education on presenters and learners.

PubMed

Lawrence, Steven L; Morzinski, Jeffrey A; Radjenovich, Mary Ellen

2008-07-01

Medical specialties are adopting methods to improve continuing medical education (CME). A "double credit" option, sponsored by the American Academy of Family Physicians, is now available for presentations submitted and approved as evidence based (EB). To compare usual and double-credit CME presentations to determine differences in preparation resources and time, and to compare conference attendees' satisfaction. Those not submitting double-credit applications were asked about perceived barriers. Three pretested, written surveys were administered at a 2.5 day CME conference held annually in Southeastern Wisconsin. Subjects were 38 presenters and 172 attendees, mostly primary care physicians. Twelve presentations were approved for double-credit; these presenters used a greater percentage of on-line EB resources to prepare their talks (64% versus 23%), and preparation required an additional 4.75 hours on average. Over 90% of attendees perceived greater conference quality due to the EB emphasis. Top barriers to double-credit EB applications were time limits and perceptions that topics were inappropriate. Double-credit presenters use a greater percentage of EB resources, while their counterparts used more professional experience to prepare CME presentations. Attendees reported improved quality and value with increased EB CME. Time is a perceived and real factor in preparing double-credit applications.

Breath Analysis as a Potential and Non-Invasive Frontier in Disease Diagnosis: An Overview

PubMed Central

Pereira, Jorge; Porto-Figueira, Priscilla; Cavaco, Carina; Taunk, Khushman; Rapole, Srikanth; Dhakne, Rahul; Nagarajaram, Hampapathalu; Câmara, José S.

2015-01-01

Currently, a small number of diseases, particularly cardiovascular (CVDs), oncologic (ODs), neurodegenerative (NDDs), chronic respiratory diseases, as well as diabetes, form a severe burden to most of the countries worldwide. Hence, there is an urgent need for development of efficient diagnostic tools, particularly those enabling reliable detection of diseases, at their early stages, preferably using non-invasive approaches. Breath analysis is a non-invasive approach relying only on the characterisation of volatile composition of the exhaled breath (EB) that in turn reflects the volatile composition of the bloodstream and airways and therefore the status and condition of the whole organism metabolism. Advanced sampling procedures (solid-phase and needle traps microextraction) coupled with modern analytical technologies (proton transfer reaction mass spectrometry, selected ion flow tube mass spectrometry, ion mobility spectrometry, e-noses, etc.) allow the characterisation of EB composition to an unprecedented level. However, a key challenge in EB analysis is the proper statistical analysis and interpretation of the large and heterogeneous datasets obtained from EB research. There is no standard statistical framework/protocol yet available in literature that can be used for EB data analysis towards discovery of biomarkers for use in a typical clinical setup. Nevertheless, EB analysis has immense potential towards development of biomarkers for the early disease diagnosis of diseases. PMID:25584743

[Epidermolysis bullosa in peru: clinical and epidemiological study of patients treated in a national reference pediatric hospital, 1993-2015].

PubMed

Torres-Iberico, Rosario; Palomo-Luck, Patricia; Torres-Ramos, Gilmer; Lipa-Chancolla, Roxana

2017-01-01

To describe the clinical and epidemiological characteristics of patients diagnosed with epidermolysis bullosa (EB) at the Instituto Nacional de Salud (INSN) in Lima, Peru; a National Reference Center for this disease. Observational, descriptive and transversal study. We reviewed the clinical histories and laboratory tests of patients diagnosed with EB treated in INSN from 1993 to 2015. 93 patients were registered. The average age was 7.9 ± 5.6 years; 53.8% (n = 50) were boys. Clinical forms corresponded to dystrophic EB with 41 (44.1%) cases, simple EB with 39 (41.9%), union EB cases with 8 (8.6%) and Kindler syndrome with 4 (4.3%) cases. The clinical form could not be identified in a case. A total of 48 cases (51.6%) came from Lima and Callao, and 45 cases (48.4%) from other provinces of the country. Extracutaneous manifestations involved gastrointestinal (44.1%), ocular (37.6%), odontogenic (87.1%), and nutritional (79.6%) involvement, as well as pseudosindactilia (16.1%). Chronic malnutrition (71.6%), acute malnutrition (17.6%) and anemia (62.4%) were found. Mortality corresponded to 6 cases (6.5%). 93 cases of EB were reported in INSN, the predominant clinical presentation was the dystrophic form.

International Collaborations on Engineered Barrier Systems: Brief Overview of SKB-EBS Activities.

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

Jove-Colon, Carlos F.

2015-10-01

Research collaborations with international partners on the behavior and performance of engineered barrier systems (EBS) are an important aspect of the DOE-NE Used Fuel Disposition Campaign strategy in the evaluation of disposal design concepts. These international partnerships are a cost-effective way of engaging in key R&D activities with common goals resulting in effective scientific knowledge exchanges thus enhancing existing and future research programs in the USA. This report provides a brief description of the activities covered by the Swedish Nuclear Fuel and Waste Management Company (SKB) EBS Task Force (TF) (referred hereafter as SKB EBS TF) and potential future directionsmore » for engagement of the DOE-NE UFDC program in relevant R&D activities. Emphasis is given to SKB EBS TF activities that are still ongoing and aligned to the UFDC R&D program. This include utilization of data collected in the bentonite rock interaction experiment (BRIE) and data sets from benchmark experiments produced by the chemistry or “C” part of the SKB EBS TF. Potential applications of information generated by this program include comparisons/tests between model and data (e.g., reactive diffusion), development and implementation of coupled-process models (e.g., HM), and code/model benchmarking.« less

Room temperature exchange bias in multiferroic BiFeO3 nano- and microcrystals with antiferromagnetic core and two-dimensional diluted antiferromagnetic shell

NASA Astrophysics Data System (ADS)

Zhang, Chuang; Wang, Shou Yu; Liu, Wei Fang; Xu, Xun Ling; Li, Xiu; Zhang, Hong; Gao, Ju; Li, De Jun

2017-05-01

Exchange bias (EB) of multiferroics presents many potential opportunities for magnetic devices. However, instead of using low-temperature field cooling in the hysteresis loop measurement, which usually shows an effective approach to obtain obvious EB phenomenon, there are few room temperature EB. In this article, extensive studies on room temperature EB without field cooling were observed in BiFeO3 nano- and microcrystals. Moreover, with increasing size the hysteresis loops shift from horizontal negative exchange bias (NEB) to positive exchange bias (PEB). In order to explain the tunable EB behaviors with size dependence, a phenomenological qualitative model based on the framework of antiferromagnetic (AFM) core-two-dimensional diluted antiferromagnet in a field (2D-DAFF) shell structure was proposed. The training effect (TE) ascertained the validity of model and the presence of unstable magnetic structure using Binek's model. Experimental results show that the tunable EB effect can be explained by the competition of ferromagnetic (FM) exchange coupling and AFM exchange coupling interaction between AFM core and 2D-DAFF shell. Additionally, the local distortion of lattice fringes was observed in hexagonal-shaped BiFeO3 nanocrystals with well-dispersed behavior. The electrical conduction properties agreed well with the space charge-limited conduction mechanism.

Analysis of Hydrogen Atom Abstraction from Ethylbenzene by an FeVO(TAML) Complex.

PubMed

Shen, Longzhu Q; Kundu, Soumen; Collins, Terrence J; Bominaar, Emile L

2017-04-17

It was shown previously (Chem. Eur. J. 2015, 21, 1803) that the rate of hydrogen atom abstraction, k, from ethylbenzene (EB) by TAML complex [Fe V (O)B*] - (1) in acetonitrile exhibits a large kinetic isotope effect (KIE ∼ 26) in the experimental range 233-243 K. The extrapolated tangents of ln(k/T) vs T -1 plots for EB-d 10 and EB gave a large, negative intercept difference, Int(EB) - Int(EB-d 10 ) = -34.5 J mol -1 K -1 for T -1 → 0, which is shown to be exclusively due to an isotopic mass effect on tunneling. A decomposition of the apparent activation barrier in terms of electronic, ZPE, thermal enthalpic, tunneling, and entropic contributions is presented. Tunneling corrections to ΔH ⧧ and ΔS ⧧ are estimated to be large. The DFT prediction, using functional B3LYP and basis set 6-311G, for the electronic contribution is significantly smaller than suggested by experiment. However, the agreement improves after correction for the basis set superposition error in the interaction between EB and 1. The kinetic model employed has been used to predict rate constants outside the experimental temperature range, which enabled us to compare the reactivity of 1 with those of other hydrogen abstracting complexes.

In Vivo and In Vitro Nitinol Corrosion Properties

NASA Astrophysics Data System (ADS)

Lonn, Melissa K.; Metcalf, Justin M.; Choules, Brian D.

2015-09-01

Regulatory authorities often require in vitro testing on medical devices prior to approval. Current standardized corrosion testing methods (ASTM F2129) require testing in a non-physiologic, de-oxygenated solution for a pre-exposure time of ≤1 h; however, no correlations between the prescribed simulated environment and whole blood conditions have been elucidated. This study compared open circuit potential (OCP), breakdown potentials (Eb), Eb - OCP, and cyclic polarization curves tested in vivo (OCP only) and in vitro in whole blood to those tested in phosphate-buffered saline (PBS). Two oxide thicknesses of Nitinol, two solution oxygen contents (deaerated and aerated solutions), and two pre-exposure durations (acute and chronic) were investigated. The in vitro OCP in whole blood was not significantly different than the in vivo OCP, suggesting that whole blood in vitro can be used to determine baseline corrosion behavior of medical implants. Eb - OCP tested per ASTM F2129 was comparable to acute whole blood and was conservative compared to chronic whole blood for both oxide thicknesses. However, OCP, Eb, and cyclic polarization curves were not always comparable to whole blood. Testing in aerated PBS achieved Eb, Eb - OCP, and cyclic polarization curves that were comparable to or more conservative than whole blood testing, regardless of pre-exposure duration and oxide thickness.

Embryoid bodies formation and differentiation from mouse embryonic stem cells in collagen/Matrigel scaffolds.

PubMed

Zhou, Jin; Zhang, Ye; Lin, Qiuxia; Liu, Zhiqiang; Wang, Haibin; Duan, Cuimi; Wang, Yanmeng; Hao, Tong; Wu, Kuiwu; Wang, Changyong

2010-07-01

Embryonic stem (ES) cells have the potential to develop into any type of tissue and are considered as a promising source of seeding cells for tissue engineering and transplantation therapy. The main catalyst for ES cells differentiation is the growth into embryoid bodies (EBs), which are utilized widely as the trigger of in vitro differentiation. In this study, a novel method for generating EBs from mouse ES cells through culture in collagen/Matrigel scaffolds was successfully established. When single ES cells were seeded in three dimensional collagen/Matrigel scaffolds, they grew into aggregates gradually and formed simple EBs with circular structures. After 7 days' culture, they formed into cystic EBs that would eventually differentiate into the three embryonic germ layers. Evaluation of the EBs in terms of morphology and potential to differentiate indicated that they were typical in structure and could generate various cell types; they were also able to form into tissue-like structures. Moreover, with introduction of ascorbic acid, ES cells differentiated into cardiomyocytes efficiently and started contracting synchronously at day 19. The results demonstrated that collagen/Matrigel scaffolds supported EBs formation and their subsequent differentiation in a single three dimensional environment. Copyright 2010 Institute of Genetics and Developmental Biology and the Genetics Society of China. Published by Elsevier Ltd. All rights reserved.

Annealing behavior of the EB-centers and M-center in low-energy electron irradiated n-type 4H-SiC

NASA Astrophysics Data System (ADS)

Beyer, F. C.; Hemmingsson, C.; Pedersen, H.; Henry, A.; Janzén, E.; Isoya, J.; Morishita, N.; Ohshima, T.

2011-05-01

After low-energy electron irradiation of epitaxial n-type 4H-SiC with a dose of 5×1016 cm-2, the bistable M-center, previously reported in high-energy proton implanted 4H-SiC, is detected in the deep level transient spectroscopy (DLTS) spectrum. The annealing behavior of the M-center is confirmed, and an enhanced recombination process is suggested. The annihilation process is coincidental with the evolvement of the bistable EB-centers in the low temperature range of the DLTS spectrum. The annealing energy of the M-center is similar to the generation energy of the EB-centers, thus partial transformation of the M-center to the EB-centers is suggested. The EB-centers completely disappeared after annealing temperatures higher than 700 ∘C without the formation of new defects in the observed DLTS scanning range. The threshold energy for moving Si atom in SiC is higher than the applied irradiation energy, and the annihilation temperatures are relatively low, therefore the M-center, EH1 and EH3, as well as the EB-centers are attributed to defects related to the C atom in SiC, most probably to carbon interstitials and their complexes.

Tidal Synchronization and Differential Rotation of Kepler Eclipsing Binaries

NASA Astrophysics Data System (ADS)

Lurie, John C.; Vyhmeister, Karl; Hawley, Suzanne L.; Adilia, Jamel; Chen, Andrea; Davenport, James R. A.; Jurić, Mario; Puig-Holzman, Michael; Weisenburger, Kolby L.

2017-12-01

Few observational constraints exist for the tidal synchronization rate of late-type stars, despite its fundamental role in binary evolution. We visually inspected the light curves of 2278 eclipsing binaries (EBs) from the Kepler Eclipsing Binary Catalog to identify those with starspot modulations, as well as other types of out-of-eclipse variability. We report rotation periods for 816 EBs with starspot modulations, and find that 79% of EBs with orbital periods of less than 10 days are synchronized. However, a population of short-period EBs exists, with rotation periods typically 13% slower than synchronous, which we attribute to the differential rotation of high-latitude starspots. At 10 days, there is a transition from predominantly circular, synchronized EBs to predominantly eccentric, pseudosynchronized EBs. This transition period is in good agreement with the predicted and observed circularization period for Milky Way field binaries. At orbital periods greater than about 30 days, the amount of tidal synchronization decreases. We also report 12 previously unidentified candidate δ Scuti and γ Doradus pulsators, as well as a candidate RS CVn system with an evolved primary that exhibits starspot occultations. For short-period contact binaries, we observe a period-color relation and compare it to previous studies. As a whole, these results represent the largest homogeneous study of tidal synchronization of late-type stars.

Breath analysis as a potential and non-invasive frontier in disease diagnosis: an overview.

PubMed

Pereira, Jorge; Porto-Figueira, Priscilla; Cavaco, Carina; Taunk, Khushman; Rapole, Srikanth; Dhakne, Rahul; Nagarajaram, Hampapathalu; Câmara, José S

2015-01-09

Currently, a small number of diseases, particularly cardiovascular (CVDs), oncologic (ODs), neurodegenerative (NDDs), chronic respiratory diseases, as well as diabetes, form a severe burden to most of the countries worldwide. Hence, there is an urgent need for development of efficient diagnostic tools, particularly those enabling reliable detection of diseases, at their early stages, preferably using non-invasive approaches. Breath analysis is a non-invasive approach relying only on the characterisation of volatile composition of the exhaled breath (EB) that in turn reflects the volatile composition of the bloodstream and airways and therefore the status and condition of the whole organism metabolism. Advanced sampling procedures (solid-phase and needle traps microextraction) coupled with modern analytical technologies (proton transfer reaction mass spectrometry, selected ion flow tube mass spectrometry, ion mobility spectrometry, e-noses, etc.) allow the characterisation of EB composition to an unprecedented level. However, a key challenge in EB analysis is the proper statistical analysis and interpretation of the large and heterogeneous datasets obtained from EB research. There is no standard statistical framework/protocol yet available in literature that can be used for EB data analysis towards discovery of biomarkers for use in a typical clinical setup. Nevertheless, EB analysis has immense potential towards development of biomarkers for the early disease diagnosis of diseases.

Polymorphism of the MHC class II Eb gene determines the protection against collagen-induced arthritis

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

Gonzalez-Gay, M.A.; Zanelli, E.; Krco, C.J.

1995-05-01

Collagen-induced arthritis (CIA) is an animal model of auto immune polyarthritis, sharing similarities with rheumatoid arthritis (RA). Paradoxally, susceptibility to mouse CIA is controlled by the H2A loci (DQ homologous) while RA is linked to HLA.DR genes (H2E homologous). We recently showed that the E{beta}{sup d} molecule prevents CIA development in susceptible H2{sup q} mice. We addressed the question of whether H2Eb polymorphism will influence CIA incidence as HLA.DRB1 polymorphism does in RA. In F{sub 1} mice, only H2Eb{sup d} and H2Eb{sup s} molecules showed protection. Using recombinant B10.RDD (Eb{sup d/b}) mice, we found that CIA protection was mediated bymore » the first domain of the E{beta}{sup d} molecule. Using peptides covering the third hypervariable region of the E{beta} chain, we found a perfect correlation between presentation of E{beta} peptides by the H2A{sup q} molecule and protection on CIA. Therefore, the mechanism by which H2Eb protects against CIA seems to rely on the affinity of E{beta} peptides for the H2A{sup q} molecule. 35 refs., 2 figs., 3 tabs.« less

Pharmacokinetics and transcriptional effects of the anti-salmon lice drug emamectin benzoate in Atlantic salmon (Salmo salar L.)

PubMed Central

Olsvik, Pål A; Lie, Kai K; Mykkeltvedt, Eva; Samuelsen, Ole B; Petersen, Kjell; Stavrum, Anne-Kristin; Lunestad, Bjørn T

2008-01-01

Background Emamectin benzoate (EB) is a dominating pharmaceutical drug used for the treatment and control of infections by sea lice (Lepeophtheirus salmonis) on Atlantic salmon (Salmo salar L). Fish with an initial mean weight of 132 g were experimentally medicated by a standard seven-day EB treatment, and the concentrations of drug in liver, muscle and skin were examined. To investigate how EB affects Atlantic salmon transcription in liver, tissues were assessed by microarray and qPCR at 7, 14 and 35 days after the initiation of medication. Results The pharmacokinetic examination revealed highest EB concentrations in all three tissues at day 14, seven days after the end of the medication period. Only modest effects were seen on the transcriptional levels in liver, with small fold-change alterations in transcription throughout the experimental period. Gene set enrichment analysis (GSEA) indicated that EB treatment induced oxidative stress at day 7 and inflammation at day 14. The qPCR examinations showed that medication by EB significantly increased the transcription of both HSP70 and glutathione-S-transferase (GST) in liver during a period of 35 days, compared to un-treated fish, possibly via activation of enzymes involved in phase II conjugation of metabolism in the liver. Conclusion This study has shown that a standard seven-day EB treatment has only a modest effect on the transcription of genes in liver of Atlantic salmon. Based on GSEA, the medication seems to have produced a temporary oxidative stress response that might have affected protein stability and folding, followed by a secondary inflammatory response. PMID:18786259

Pharmacokinetics and transcriptional effects of the anti-salmon lice drug emamectin benzoate in Atlantic salmon (Salmo salar L.).

PubMed

Olsvik, Pål A; Lie, Kai K; Mykkeltvedt, Eva; Samuelsen, Ole B; Petersen, Kjell; Stavrum, Anne-Kristin; Lunestad, Bjørn T

2008-09-11

Emamectin benzoate (EB) is a dominating pharmaceutical drug used for the treatment and control of infections by sea lice (Lepeophtheirus salmonis) on Atlantic salmon (Salmo salar L). Fish with an initial mean weight of 132 g were experimentally medicated by a standard seven-day EB treatment, and the concentrations of drug in liver, muscle and skin were examined. To investigate how EB affects Atlantic salmon transcription in liver, tissues were assessed by microarray and qPCR at 7, 14 and 35 days after the initiation of medication. The pharmacokinetic examination revealed highest EB concentrations in all three tissues at day 14, seven days after the end of the medication period. Only modest effects were seen on the transcriptional levels in liver, with small fold-change alterations in transcription throughout the experimental period. Gene set enrichment analysis (GSEA) indicated that EB treatment induced oxidative stress at day 7 and inflammation at day 14. The qPCR examinations showed that medication by EB significantly increased the transcription of both HSP70 and glutathione-S-transferase (GST) in liver during a period of 35 days, compared to un-treated fish, possibly via activation of enzymes involved in phase II conjugation of metabolism in the liver. This study has shown that a standard seven-day EB treatment has only a modest effect on the transcription of genes in liver of Atlantic salmon. Based on GSEA, the medication seems to have produced a temporary oxidative stress response that might have affected protein stability and folding, followed by a secondary inflammatory response.

Emotional burnout, perceived sources of job stress, professional fulfillment, and engagement among medical residents in Malaysia.

PubMed

Al-Dubai, Sami Abdo Radman; Ganasegeran, Kurubaran; Perianayagam, Wilson; Rampal, Krishna Gopal

2013-01-01

This study was the first to explore factors associated with emotional burnout (EB) among medical residents in Malaysia. A cross-sectional study was conducted in a universal sample of 205 medical residents in a Malaysian general hospital. The self-administered questionnaire used consisted of questions on sociodemographics and work characteristics, sources of job stress, professional fulfillment, engagement, and EB. EB was measured using the emotional exhaustion subscale, the Maslach Burnout Inventory (MBI). Mean (±SD) age of the respondents was 26.5 (±1.6). The most common source of job stress was "fear of making mistakes." Most of the participants were dissatisfied with the increase of residentship period from one year to two years. A high level of EB was reported by 36.6% of the respondents. In multivariate analysis, the most important correlates of EB were sources of job stress, professional fulfillment, and engagement. A high prevalence of EB was found among medical residents. Sociodemographic characteristics, performance pressure, and satisfaction with policies were significantly associated with EB. Although this study was limited by its cross-sectional design, its findings posit a sufficient foundation to relevant authorities to construct, amend, and amalgamate existing and future policies. Nothing will sustain you more potently than the power to recognize in your humdrum routine, as perhaps it may be thought, the true poetry of life-the poetry of the common place, of the common man, of the plain, toil-worn woman, with their loves and their joys, their sorrows and their grief.SirWilliam Osler, Aphorisms from the Student Life (Aequanimitas, 1952).

Purification and partial characterization of the major outer membrane protein of Chlamydia trachomatis

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

Caldwell, H.D.; Kromhout, J.; Schachter, J.

1981-03-01

Elementary bodies (EB) of Chlamydia trachomatis serotypes C, E, and L2 were extrinsically radioiodinated, and whole-cell lysates of these serotypes were compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Autoradiography of the polypeptide profiles identified a major surface protein with an apparent subunit molecular weight of 39,500 that was common to each C. trachomatis serotype. The abilities of nonionic (Triton X-100), dipolar ionic (Zwittergent TM-314), mild (sodium deoxycholate and sodium N-lauroyl sarcosine), and strongly anionic (SDS) detergents to extract this protein from intact EB of the L2 serotype were investigated by SDS-PAGE analysis of the soluble and insoluble fractions obtainedmore » after each detergent treatment. Only SDS readily extracted this protein from intact EB. Sarkosyl treatment selectively solubilized the majority of other EB proteins, leaving the 39,500-dalton protein associated with the Sarkosyl-insoluble fraction. Ultrastructural studies of the Sarkosyl-insoluble EB pellet showed it to consist of empty EB particles possessing an apparently intact outer membrane. No structural evidence for a peptidoglycan-like cell wall was found. Morphologically these chlamydial outer membrane complexes (COMC) resembled intact chlamydial EB outer membranes. The 39,500-dalton outer membrane protein was quantitatively extracted from COMC by treating them with 2% SDS at 60 degrees C. This protein accounted for 61% of the total COMC-associated protein, and its extraction resulted in a concomitant loss of the COMC membrane structure and morphology. The 39,500-dalton major outer membrane protein is a serogroup antigen of C. trachomatis organisms.« less

Mouse embryonic stem cell-derived cells reveal niches that support neuronal differentiation in the adult rat brain.

PubMed

Maya-Espinosa, Guadalupe; Collazo-Navarrete, Omar; Millán-Aldaco, Diana; Palomero-Rivero, Marcela; Guerrero-Flores, Gilda; Drucker-Colín, René; Covarrubias, Luis; Guerra-Crespo, Magdalena

2015-02-01

A neurogenic niche can be identified by the proliferation and differentiation of its naturally residing neural stem cells. However, it remains unclear whether "silent" neurogenic niches or regions suitable for neural differentiation, other than the areas of active neurogenesis, exist in the adult brain. Embryoid body (EB) cells derived from embryonic stem cells (ESCs) are endowed with a high potential to respond to specification and neuralization signals of the embryo. Hence, to identify microenvironments in the postnatal and adult rat brain with the capacity to support neuronal differentiation, we transplanted dissociated EB cells to conventional neurogenic and non-neurogenic regions. Our results show a neuronal differentiation pattern of EB cells that was dependent on the host region. Efficient neuronal differentiation of EB cells occurred within an adjacent region to the rostral migratory stream. EB cell differentiation was initially patchy and progressed toward an even distribution along the graft by 15-21 days post-transplantation, giving rise mostly to GABAergic neurons. EB cells in the striatum displayed a lower level of neuronal differentiation and derived into a significant number of astrocytes. Remarkably, when EB cells were transplanted to the striatum of adult rats after a local ischemic stroke, increased number of neuroblasts and neurons were observed. Unexpectedly, we determined that the adult substantia nigra pars compacta, considered a non-neurogenic area, harbors a robust neurogenic environment. Therefore, neurally uncommitted cells derived from ESCs can detect regions that support neuronal differentiation within the adult brain, a fundamental step for the development of stem cell-based replacement therapies. © 2014 AlphaMed Press.

Development of a clinical diagnostic matrix for characterizing inherited epidermolysis bullosa.

PubMed

Yenamandra, V K; Moss, C; Sreenivas, V; Khan, M; Sivasubbu, S; Sharma, V K; Sethuraman, G

2017-06-01

Accurately diagnosing the subtype of epidermolysis bullosa (EB) is critical for management and genetic counselling. Modern laboratory techniques are largely inaccessible in developing countries, where the diagnosis remains clinical and often inaccurate. To develop a simple clinical diagnostic tool to aid in the diagnosis and subtyping of EB. We developed a matrix indicating presence or absence of a set of distinctive clinical features (as rows) for the nine most prevalent EB subtypes (as columns). To test an individual patient, presence or absence of these features was compared with the findings expected in each of the nine subtypes to see which corresponded best. If two or more diagnoses scored equally, the diagnosis with the greatest number of specific features was selected. The matrix was tested using findings from 74 genetically characterized patients with EB aged > 6 months by an investigator blinded to molecular diagnosis. For concordance, matrix diagnoses were compared with molecular diagnoses. Overall, concordance between the matrix and molecular diagnoses for the four major types of EB was 91·9%, with a kappa coefficient of 0·88 [95% confidence interval (CI) 0·81-0·95; P < 0·001]. The matrix achieved a 75·7% agreement in classifying EB into its nine subtypes, with a kappa coefficient of 0·73 (95% CI 0·69-0·77; P < 0·001). The matrix appears to be simple, valid and useful in predicting the type and subtype of EB. An electronic version will facilitate further testing. © 2016 British Association of Dermatologists.

Characterization of the biochemical, physiological, and medicinal properties of Streptomyces hygroscopicus ACTMS-9H isolated from the Amazon (Brazil).

PubMed

Lima, Sandrine M A; Melo, Janaína G S; Militão, Gardênia C G; Lima, Gláucia M S; do Carmo A Lima, Maria; Aguiar, Jaciana S; Araújo, Renata M; Braz-Filho, Raimundo; Marchand, Pascal; Araújo, Janete M; Silva, Teresinha G

2017-01-01

Actinomycetes are known to produce numerous secondary bioactive metabolites of pharmaceutical interest. The purpose of this study was to isolate, characterize, and investigate the antibacterial, antifungal, and anticancer activities of metabolites produced by Actinobacteria isolated from the rhizosphere of Paullinia cupana. The Actinobacteria was identified as Streptomyces hygroscopicus ACTMS-9H. Based on a bioguided study, the methanolic biomass extract obtained from submerged cultivation had the most potent antibacterial, antifungal, and cytotoxic activities. This extract was partitioned with n-hexane, ethyl acetate, and 2-butanol. Elaiophylin was isolated from the methanolic biomass extract, and its molecular formula was determined (C 54 H 88 O 18 ) based on 1 H and 13 C NMR, IR and MS analyses. The 2-butanol phase was fractionated into four fractions (EB1, EB2A, EB2B, and EB3M). Chemical prospecting indicated the presence of alkaloids, saponins, and reducing sugars in the methanolic extract and 2-butanol phase. The elaiophylin displayed anticancer activity in HEp-2 and HL-60 cells with an IC 50 of 1 μg/mL. The EB1 fraction was selectively toxic to HL-60 cells with IC 50 of 9 ng/mL. Bioautography showed that the EB1 fraction contained an alkaloid with antibacterial and antifungal activities (MIC values ≤1.9 and <3.9 μg/mL, respectively). In conclusion, the EB1 fraction and elaiophylin of S. hygroscopicus have potent antimicrobial, antifungal, and anticancer activities.

Fabrication of thermo-responsive PNIPAAm-g-ETFE for cell culture dishes by pre-irradiation grafting

NASA Astrophysics Data System (ADS)

Yamahara, Yumi; Nagasawa, Naotsugu; Taguchi, Mitsumasa; Oshima, Akihiro; Washio, Masakazu

2018-01-01

Thermo-responsive templates for the cell cultivation based on Poly(tetrafluoroethylene-co-ethylene) (ETFE) were fabricated by pre-irradiation grafting of N-isoproplyacrylamide (NIPAAm) monomer by electron beam (EB) irradiation under nitrogen gas atmosphere at room temperature, and their characteristic properties were studied. The detachment of cultured HeLa cells from fabricated thermo-responsive templates were attempted. Furthermore, the reaction mechanism is proposed using ESR spectroscopy and FT-IR spectroscopy. It is confirmed that the cultured HeLa cells were detached from fabricated thermo-responsive templates at 20 °C. Water contact angle analysis indicated that obtained templates had thermo-response around 30 °C. It is suggested that the grafted polymer chains would mainly react with peroxy radicals (-CF2-CF(OO･)-) on tetrafluoroethylene unit in ETFE.

Microstructure engineering of Pt-Al alloy thin films through Monte Carlo simulations

NASA Astrophysics Data System (ADS)

Harris, R. A.; Terblans, J. J.; Swart, H. C.

2014-06-01

A kinetic algorithm, based on the regular solution model, was used in conjunction with the Monte Carlo method to simulate the evolution of a micro-scaled thin film system during exposure to a high temperature environment. Pt-Al thin films were prepared via electron beam physical vapor deposition (EB-PVD) with an atomic concentration ratio of Pt63:Al37. These films were heat treated at an annealing temperature of 400 °C for 16 and 49 minutes. Scanning Auger Microscopy (SAM) (PHI 700) was used to obtain elemental maps while sputtering through the thin films. Simulations were run for the same annealing temperatures and thin-film composition. From these simulations theoretical depth profiles and simulated microstructures were obtained. These were compared to the experimentally measured depth profiles and elemental maps.

Evaluation of resistive switching properties of Si-rich oxide embedded with Ti nanodots by applying constant voltage and current

NASA Astrophysics Data System (ADS)

Ohta, Akio; Kato, Yusuke; Ikeda, Mitsuhisa; Makihara, Katsunori; Miyazaki, Seiichi

2018-06-01

We have studied the resistive switching behaviors of electron beam (EB) evaporated Si-rich oxide (SiO x ) sandwiched between Ni electrodes by applying a constant voltage and current. Additionally, the impact of Ti nanodots (NDs) embedded into SiO x on resistive switching behaviors was investigated because it is expected that NDs can trigger the formation of a conductive filament path in SiO x . The resistive switching behaviors of SiO x show that the response time during resistance switching was decreased by increasing the applied constant current or constant voltage. It was found that Ti-NDs in SiO x enhance the conductive filament path formation owing to electric field concentration by Ti-NDs.

Effect of antioxidants on the dentin interface bond stability of adhesives exposed to hydrolytic degradation.

PubMed

Gotti, Valéria B; Feitosa, Victor P; Sauro, Salvatore; Correr-Sobrinho, Lourenço; Leal, Fernanda B; Stansbury, Jeffrey W; Correr, Américo B

2015-02-01

This study assessed the effect of antioxidants vitamin C (Vit. C), vitamin E (Vit. E) and quercetin (Querc) on the dentin bonding performance, degree of conversion, and rate of polymerization of three commercial adhesive systems (Adper Single Bond 2 [SB], Clearfil SE Bond [CSE], Adper Easy Bond [EB]). Human premolars were restored using antioxidant-doped adhesives. The samples were stored for 24 h in distilled water or 6 months under simulated pulpal pressure. Teeth were cut into sticks and the microtensile bond strength (μTBS) to dentin was tested in a universal testing machine. Qualitative nanoleakage analysis was performed from a central stick of each restored tooth. Degree of conversion and rate of polymerization of adhesive systems were evaluated in triplicate using real-time FT-IR. Although the inclusion of the antioxidants negatively affected the μTBS over 24 h, the antioxidant-doped adhesives maintained (SB-Vit. C, SB-Vit. E, CSE-Vit. C, EB-Querc) or increased (SB-Querc, CSE-Vit. E, CSE-Querc, EB-Vit. E, and EB-Vit. C) their μTBS during 6 months of storage. Only the μTBS of Adper Single Bond 2 dropped significantly after 6 months among the control groups. Slight changes in the nanoleakage pattern after aging were observed in all groups, except for the EB-control group, which showed a noteworthy increase in nanoleakage after 6 months, and for EB-Vit. C, which presented a remarkable decrease. A lower degree of conversion was obtained with all antioxidants in SB and EB, except for the EB-Vit. E group. Similar degrees of conversion were attained in control and experimental groups for CSE. The rate of polymerization was reduced in antioxidant-doped adhesives. The performance of antioxidants changed according to the adhesive system to which they were added, and antioxidant-doped adhesives appear to have a positive effect on the adhesive interface durability, since their bond strength obtained after 24 h was maintained or increased over time.

A common-garden experiment to quantify evolutionary processes in copepods: the case of emamectin benzoate resistance in the parasitic sea louse Lepeophtheirus salmonis.

PubMed

Ljungfeldt, Lina Eva Robin; Espedal, Per Gunnar; Nilsen, Frank; Skern-Mauritzen, Mette; Glover, Kevin Alan

2014-05-19

The development of pesticide resistance represents a global challenge to food production. Specifically for the Atlantic salmon aquaculture industry, parasitic sea lice and their developing resistance to delousing chemicals is challenging production. In this study, seventeen full sibling families, established from three strains of Lepeophtheirus salmonis displaying differing backgrounds in emamectin benzoate (EB) tolerance were produced and quantitatively compared under a common-garden experimental design. Lice surviving to the preadult stage were then exposed to EB and finally identified through the application of DNA parentage testing. With the exception of two families (19 and 29%), survival from the infectious copepod to preadult stage was very similar among families (40-50%). In contrast, very large differences in survival following EB exposure were observed among the families (7.9-74%). Family survival post EB exposure was consistent with the EB tolerance characteristics of the strains from which they were established and no negative effect on infection success were detected in association with increased EB tolerance. Two of the lice families that displayed reduced sensitivity to EB were established from a commercial farm that had previously used this chemical. This demonstrates that resistant alleles were present on this farm even though the farm had not reported treatment failure. To our knowledge, this represents the first study where families of any multi-cellular parasite have been established and compared in performance under communal rearing conditions in a common-garden experiment. The system performed in a predictable manner and permitted, for the first time, elucidation of quantitative traits among sea lice families. While this experiment concentrated on, and provided a unique insight into EB sensitivity among lice families, the experimental design represents a novel methodology to experimentally address both resistance development and other evolutionary questions in parasitic copepods.

A common-garden experiment to quantify evolutionary processes in copepods: the case of emamectin benzoate resistance in the parasitic sea louse Lepeophtheirus salmonis

PubMed Central

2014-01-01

Background The development of pesticide resistance represents a global challenge to food production. Specifically for the Atlantic salmon aquaculture industry, parasitic sea lice and their developing resistance to delousing chemicals is challenging production. In this study, seventeen full sibling families, established from three strains of Lepeophtheirus salmonis displaying differing backgrounds in emamectin benzoate (EB) tolerance were produced and quantitatively compared under a common-garden experimental design. Lice surviving to the preadult stage were then exposed to EB and finally identified through the application of DNA parentage testing. Results With the exception of two families (19 and 29%), survival from the infectious copepod to preadult stage was very similar among families (40-50%). In contrast, very large differences in survival following EB exposure were observed among the families (7.9-74%). Family survival post EB exposure was consistent with the EB tolerance characteristics of the strains from which they were established and no negative effect on infection success were detected in association with increased EB tolerance. Two of the lice families that displayed reduced sensitivity to EB were established from a commercial farm that had previously used this chemical. This demonstrates that resistant alleles were present on this farm even though the farm had not reported treatment failure. Conclusions To our knowledge, this represents the first study where families of any multi-cellular parasite have been established and compared in performance under communal rearing conditions in a common-garden experiment. The system performed in a predictable manner and permitted, for the first time, elucidation of quantitative traits among sea lice families. While this experiment concentrated on, and provided a unique insight into EB sensitivity among lice families, the experimental design represents a novel methodology to experimentally address both resistance development and other evolutionary questions in parasitic copepods. PMID:24885085

Solubility and disintegration of new calcium aluminate cement (EndoBinder) containing different radiopacifying agents.

PubMed

Garcia, Lucas da Fonseca Roberti; Chinelatti, Michelle Alexandra; Rossetto, Hebert Luis; Pires-de-Souza, Fernanda de Carvalho Panzeri

2014-02-01

The aim of this study was to evaluate the solubility and disintegration of EndoBinder (EB) containing 3 different radiopacifying agents, bismuth oxide (Bi2O3), zinc oxide (ZnO), or zirconium oxide (ZrO2), in comparison with gray mineral trioxide aggregate (GMTA) and white MTA (WMTA). Ten specimens of each cement were made in a stainless steel matrix (20 × 1.5 mm) according to Specification no. 57 of American National Standards Institute/American Dental Association: EB + Bi2O3, EB + ZrO, EB + ZnO, WMTA, and GMTA. The specimens were weighed on an accurate analytical scale and immersed in 50 mL distilled and deionized water at 37°C for 7 days. Afterwards, specimens were dried and weighed again to determine mass loss (%). Resulting solutions were analyzed in an atomic absorption spectrophotometer for identification and quantification of chemical elements released. All cements presented mean values of solubility and disintegration above the American National Standards Institute/American Dental Association Specification no. 57. EB + Bi2O3 presented the lowest mass loss (5.08%) and WMTA (6.65%) the highest, with no statistically significant difference (P > .05). The release of several chemical elements was observed, mostly metal ions. Only GMTA and EB + Bi2O3 showed the presence of Cr, with significant difference (P < .05). EB + ZnO presented the highest levels of Pb, followed by WMTA (P < .05). For As, the cements presented different release levels, with EB + ZnO showing the highest and GMTA the lowest levels (P < .05). However, the amounts of As and Pb released were lower than the safe limit proposed by ISO 9917-1. Irrespective of the radiopacifying agents used, EndoBinder presented similar behavior to MTA. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Effects of chlorogenic acid on adenine nucleotides hydrolyzing enzyme activities and expression in platelets of rats experimentally demyelinated with ethidium bromide.

PubMed

Leal, Claudio A M; Leal, Daniela B R; Adefegha, Stephen A; Morsch, Vera M; Beckmann, Diego V; Castilhos, Lívia G; Thorstenberg, Maria L P; Jaques, Jeandre A Dos S; Souza, Viviane do C G; Farias, Júlia G; Martins, Caroline C; Schetinger, Maria R C

2016-07-01

The effects of chlorogenic acid (one of the major phenolic acid found in human diets) were investigated on the adenine nucleotides hydrolyzing enzymes; ecto-nucleotide pyrophosphatase/phophodiesterase (E-NPP), ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase), E-5'- nucleotidase and ecto-adenosine deaminase (E-ADA) activities and expression in platelets of rats experimentally demyelinated with ethidium bromide. Rats were divided into four groups of eight animals each. Group I rats were control rats; injected with saline (CT), group II rats were injected with saline and treated with chlorogenic acid (AC), group III rats were injected with 0.1% ethidium bromide (EB) and group IV rats were injected with 0.1% EB and treated with chlorogenic acid (EB+AC). The activities of the enzymes were analyzed using colorimetric methods, and the gene expression of NTPDase 1, 2 and 3 were analyzed using the polymerase chain reaction (PCR). The results revealed that there was a significant (P<0.01) reduction in E-NPP activity in EB group (1.63±0.10nmol p-nitrophenol released/min/mg protein) when compared to CT group (2.33±0.14nmol p-nitrophenol released/min/mg protein). However, treatment with chlorogenic acid significantly (P<0.05) increased E-NPP activity in EB group. Furthermore, no significant (P>0.05) change was observed in the E-NPP activity of EB+AC group (2.19±0.08nmol p-nitrophenol released/min/mg protein) when compared to CT group (2.33±0.14nmol p-nitrophenol released/min/mg protein). In addition, there was a significant (P<0.05) increase in AMP hydrolysis in EB rat group when compared to CT group. No significant (P>0.05) difference was observed in AMP hydrolysis between AC, AC+EB and CT groups. Conversely, there were no significant (P>0.05) differences in ATP and ADP hydrolyses between all the groups (AC, EB, AC+EB and CT groups). Likewise, there were no significant (P>0.05) changes in E-ADA activity and percentage platelet aggregation among all groups studied. Similarly, no significant (P>0.05) change was observed in the expression of E-NTPDase 1, 2 and 3 in all the groups tested. Our study revealed that chlorogenic acid may modulate the hydrolysis of adenine nucleotides in platelets of rats demyelinated and treated with chlorogenic acid via alteration of E-NPP and ecto-5'-nucleotidase activities. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Persistence of blood changes associated with alteration of the dietary electrolyte balance in commercial pigs after feed withdrawal, transportation, and lairage, and the effects on performance and carcass quality.

PubMed

Edwards, L N; Engle, T E; Paradis, M A; Correa, J A; Anderson, D B

2010-12-01

Increasing dietary electrolyte balance (dEB) has previously been shown to reduce the incidence of nonambulatory and noninjured swine, improve meat quality, and reduce the incidence of gastric ulcers. The objective of this study was to evaluate the effect of dEB under commercial conditions. Due to the variability in feed withdrawal, transport, and lairage conditions in the swine industry, it was necessary to determine first the persistence of blood changes during the marketing process after alteration of dEB. Sixteen pens of 8 crossbred barrows were assigned to a low (121 mEq/kg) or high (375 mEq/kg) dEB diet, calculated as Na(+) + K(+) - Cl(-), to determine the persistence of blood changes associated with the alteration of dEB. Diets were formulated to meet or exceed NRC (1998) requirements for energy, protein, vitamins, and minerals. Dietary treatments were provided for ad libitum intake for 3 d before slaughter. Before transport, animals were fasted in the barn for approximately 10 h. After fasting, animals were shipped to the packing plant, rested for 8 h, and subsequently slaughtered. Initial and final BW of the animals were obtained. Blood was sampled at baseline (2 d before administration of diets), before feed withdrawal (0 h), after feed withdrawal (10 h), and at exsanguination (20 h). Consumption of the high dEB diet for 3 d resulted in an increase in blood TCO(2) (P = 0.001), HCO(3)(-) (P = 0.001), and base excess (P = 0.0003) and a decrease in Cl(-) (P = 0.0002) and anion gap (P = 0.01). These differences, however, were not maintained for any of the blood components after the 10-h feed withdrawal (P > 0.22). Increasing dEB had no adverse effects (P > 0.18) on growth performance, meat quality, or carcass yield and did not decrease pars esophageal ulcer scores. This study demonstrated that the effect of dEB on blood components was not maintained after a 10-h feed withdrawal. Therefore, it is likely that the ability of the animal to withstand any increased metabolic acid load associated with the stress of transport was lost after feed withdrawal. Further research is needed to determine the effects of dEB alteration in animals that have not been fasted before shipment and using diets with a larger difference in dEB.

Evidence-based medicine in daily surgical decision making: a survey-based comparison between the UK and Germany.

PubMed

Schnitzbauer, Andreas A; Proneth, Andrea; Pengel, Liset; Ansorg, Jörg; Anthuber, Matthias; Bechstein, Wolf O; Schlitt, Hans J; Geissler, Edward K

2015-01-01

Evidence-based medicine (EbM) is a vital part of reasonable and conclusive decision making for clinicians in daily clinical work. To analyze the knowledge and the attitude of surgeons towards EbM, a survey was performed in the UK and Germany. A web-based questionnaire was distributed via mailing lists from the Royal College of Surgeons of England (RCSE) and the Berufsverband Deutscher Chirurgen (BDC). Our primary aim was to get information about knowledge of EbM amongst German and British surgeons. A total of 549 individuals opened the questionnaire, but only 198 questionnaires were complete and valid for analysis. In total, 40,000 recipients were approached via the mailing lists of the BDC and RCSE. The response rate was equally low in both countries. On a scale from 1 (unimportant) to 10 (very important), all participants rated EbM as very important for daily clinical decision making (7.3 ± 1.9) as well as for patients (7.8 ± 1.9) and the national health system (7.8 ± 1.9). On a scale from 1 (unimportant) to 5 (very important), systematic reviews (4.6 ± 0.6) and randomized controlled trials (4.6 ± 0.6) were identified as the highest levels of study designs to enhance evidence in medicine. British surgeons considered EbM to be more important in daily clinical work when compared to data from German surgeons (7.9 ± 1.6 vs. 6.7 ± 2.1, p < 0.001). Subgroup analysis showed different results in some categories; however, a pattern to explain the differences was not evident. Personal requirements expressed in a free text field emphasized the results and reflected concerns such as broad unwillingness and lack of interdisciplinary approaches for patients (n = 59: 25 in the UK and 34 in Germany). The overall results show that EbM is believed to be important by surgeons in the UK and Germany. However, perception of EbM in the respective health system (UK vs. Germany) may be different. Nonetheless, EbM is an important tool to navigate through daily clinical problems although a discrepancy between the knowledge of theoretical abstract terms and difficulties in implementing EbM in daily clinical work has been detected. The provision of infrastructure, courses and structured education as a permanent instrument will advance the knowledge, application and improvement of EbM in the future. © 2014 S. Karger AG, Basel.

Laminar flow control perforated wing panel development

NASA Technical Reports Server (NTRS)

Fischler, J. E.

1986-01-01

Many structural concepts for a wing leading edge laminar flow control hybrid panel were analytically investigated. After many small, medium, and large tests, the selected design was verified. New analytic methods were developed to combine porous titanium sheet bonded to a substructure of fiberglass and carbon/epoxy cloth. At -65 and +160 F test conditions, the critical bond of the porous titanium to the composite failed at lower than anticipated test loads. New cure cycles, design improvements, and test improvements significantly improved the strength and reduced the deflections from thermal and lateral loadings. The wave tolerance limits for turbulence were not exceeded. Consideration of the beam column midbay deflections from the combinations of the axial and lateral loadings and thermal bowing at -65 F, room temperature, and +160 F were included. Many lap shear tests were performed at several cure cycles. Results indicate that sufficient verification was obtained to fabricate a demonstration vehicle.

Aging Effects of Environmentally-Friendly Cleaners on Adhesive Bond Integrity

NASA Technical Reports Server (NTRS)

Biegert, L. L.; Anderson, G. L.; Evans, K. B.; Olsen, B. D.; Weber, B. L.; McCool, A. A. (Technical Monitor)

2000-01-01

Because of the 1990 Clean Air Act Amendment many chlorinated solvents are being phased out of use in manufacturing industries. Replacement of the ODC (ozone- depleting chemicals) with less volatile, non-ozone depleting cleaners has been extensively studied over the past nine years at Thiokol Propulsion, Cordant Technologies. Many of the non-ODC cleaners contain compounds that can potentially degrade over time under conditions of high temperature, humidity and exposure to light. The chemical composition of environmentally conditioned cleaners and the subsequent effect on aluminum/amine-cured epoxy bond integrity as measured by Tapered Double Cantilever Beam were evaluated. From this study it is observed that moisture content increases for those cleaners containing polar compounds. Non-volatile residue content increases as stabilizers are depleted and the chemical compound limonene is oxidized. A change in aluminum/ amine-cured epoxy bond fracture toughness is observed as some of these cleaners age with increases in moisture and NVR content.

Effect of ZrO2 Powders on the Pyrolysis of Polycarbosilanes Coating Under Laser Ablation

NASA Astrophysics Data System (ADS)

Cheng, Han; Chen, Zhaofeng; Tao, Jie; Yan, Bo; Li, Cong; Wang, Liangbing; Zhang, Ying; Fang, Dan; Wan, Shuicheng; Wu, Wangping

Aircrafts hold the outstanding mastery of the sky in modern wars, however the laser beam weapons can carry out laser attacking to aircrafts. The purpose of the present paper is to research on a new type laser protective material. Polycarbosilanes (PCS)/divinylbenzene mixtures containing ZrO2 powders were brushed to the surface of the aluminum alloy plates and then cured at 150°C for 6 h. The PCS-coated plates were ablated by laser for 3 s. The phase identification of as-ablated powders was examined by X-ray diffraction. The results indicated that the as-ablated powders of cured PCS were composed of major phase β-SiC and smaller amounts of free carbon. The PCS composite coating played a certain role of laser ablation resistance. The effect of added ZrO2 powders on the pyrolysis of PCS-coating under laser ablation is conspicuous.

Comparative Studies on Microstructure, Mechanical and Pitting Corrosion of Post Weld Heat Treated IN718 Superalloy GTA and EB Welds

NASA Astrophysics Data System (ADS)

Dilkush; Mohammed, Raffi; Madhusudhan Reddy, G.; Srinivasa Rao, K.

2018-03-01

In the present study, an attempt has been made to weld Inconel 718 nickel-base superalloy (IN718 alloy) using gas tungsten arc welding (GTAW) and electron beam welding (EBW) processes. Both the weldments were subjected to post-weld heat treatment condition as follows -980°C / 20 min followed by direct aging condition (DA) as 720°C/8 h/FC followed by 620°C/8 h/AC. The GTA and EB welds of IN718 alloy were compared in two conditions as-received and 980STA conditions. Welds were characterized to observe mechanical properties, pitting corrosion resistance by correlating with observed microstructures. The rate of higher cooling ranges, the fusion zone of EBW exhibited discrete and relative finer lave phases whereas the higher niobium existed laves with coarser structure were observed in GTAW. The significant dissolution of laves were observed at 980STA of EBW. Due to these effects, the EBW of IN718 alloy showed the higher mechanical properties than GTAW. The electrochemical potentiostatic etch test was carried out in 3.5wt% sodium chloride (NaCl) solution to study the pitting corrosion behaviour of the welds. Results of the present investigation established that mechanical properties and pitting corrosion behaviour are significantly better in post weld heat treated condition. The comparative studies showed that the better combination of mechanical properties and pitting corrosion resistance were obtained in 980STA condition of EBW than GTAW.

Effect of La2O3 addition on interface chemistry between 4YSZ top layer and Ni based alloy bond coat in thermal barrier coating by EB PVD.

PubMed

Park, Chan-Young; Yang, Young-Hwan; Kim, Seong-Won; Lee, Sung-Min; Kim, Hyung-Tae; Jang, Byung-Koog; Lim, Dae-Soon; Oh, Yoon-Suk

2014-11-01

The effect of a 5 mol% La2O3 addition on the forming behavior and compositional variation at interface between a 4 mol% Yttria (Y2O3) stabilized ZrO2 (4YSZ) top coat and bond coat (NiCrAlY) as a thermal barrier coating (TBC) has been investigated. Top coats were deposited by electron beam physical vapor deposition (EB PVD) onto a super alloy (Ni-Cr-Co-Al) substrate without pre-oxidation of the bond coat. Top coats are found to consist of dense columnar grains with a thin interdiffusion layer between metallic bond coats. In the as-received 4YSZ coating, a thin interdiffusion zone at the interface between the top and bond coats was found to consist of a Ni-Zr intermetallic compound with a reduced quantity of Y, Al or O elements. On the other hand, in the case of an interdiffusion area of 5 mol% La2O3-added 4YSZ coating, it was found that the complicated composition and structure with La-added YSZ and Ni-Al rich compounds separately. The thermal conductivity of 5 mol% La2O3-added 4YSZ coating (- 1.6 W/m x k at 1100 degrees C) was lower than a 4YSZ coating (- 3.2 W/m x k at 1100 degrees C) alone.

Defense Logistics Agency Did Not Fully Implement the Business Enterprise Architecture Procure-to-Pay Business Process in the Enterprise Business System

DTIC Science & Technology

2014-10-28

change. Enterprise Business System In August 2000, DLA began developing its Enterprise Resource Planning ( ERP ) system by initiating the Business...the EBS core system. EBS became the ERP system solution supporting DLA nonenergy commodity activities. DLA subsequently enhanced its EBS...capabilities by adding SAP software that supported DLA Enterprise Operational Accounting, real property, and inventory management functions. As part of the

Nanoplasmonic Phenomena at Electronic Boundaries in Graphene

DOE PAGES

Fei, Zhe; Ni, Guang -Xin; Jiang, Bor -Yuan; ...

2017-06-30

Here, we review recent discoveries of the intriguing plasmonic phenomena at a variety of electronic boundaries (EBs) in graphene including a line of charges in graphene induced by a carbon nanotube gate, grain boundaries in chemical vapor deposited graphene films, an interface between graphene and moiré patterned graphene, an interface between graphene and bilayer graphene, and others. All these and other EBs cause plasmonic impedance mismatch at the two sides of the boundaries. Manifestations of this effect include plasmonic fringes that stem from plasmon reflections and interference. Quantitative analysis and modeling of these plasmonic fringes uncovered intriguing properties and underlyingmore » physics of the EBs. Potential plasmonic applications associated with these EBs are also briefly discussed.« less

Nanoplasmonic Phenomena at Electronic Boundaries in Graphene

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

Fei, Zhe; Ni, Guang -Xin; Jiang, Bor -Yuan

Here, we review recent discoveries of the intriguing plasmonic phenomena at a variety of electronic boundaries (EBs) in graphene including a line of charges in graphene induced by a carbon nanotube gate, grain boundaries in chemical vapor deposited graphene films, an interface between graphene and moiré patterned graphene, an interface between graphene and bilayer graphene, and others. All these and other EBs cause plasmonic impedance mismatch at the two sides of the boundaries. Manifestations of this effect include plasmonic fringes that stem from plasmon reflections and interference. Quantitative analysis and modeling of these plasmonic fringes uncovered intriguing properties and underlyingmore » physics of the EBs. Potential plasmonic applications associated with these EBs are also briefly discussed.« less

Supramolecular Assembly of Tripodal Trisamides

NASA Astrophysics Data System (ADS)

Feng, Li

2010-03-01

A series of tripodal trisamide compounds have been synthesized from tris(2-aminoethyl)amine (TREN) by condensation with different acid chlorides. Gelation of organic solvents with these compounds was investigated as a function of concentration and solvent solubility parameter. Compounds made with linear acid chlorides were poor gelators. A gelator made with 2-ethylbutyryl chloride (TREN-EB) was an excellent gelator for many organic solvents. It was found that the minimum gelation concentration of TREN-EB increased with increasing solubility parameter of the solvent. Thin films samples were prepared by spin-coating mixtures of TREN-EB and a poly(acrylate). Scanning force microscopy measurements showed that TREN-EB formed nanofibrillar network structures. In addition a dependence of the network morphology on the casting solvent was found.

Development of a Wireless Brain Implant: The Telemetric Electrode Array System (TEAS) Project

DTIC Science & Technology

2001-10-25

8 array connected to an electronic system through a special polyimide flexible cable. The neuronal signals recorded by the electrode array at 1 mm...deposition prior to applying an insulation coating of glass using electron-beam deposition or a biocompatible epoxy through a dipping process. In the case...layer can be made relatively easily, by melting and cooling glass powder or curing biocompatible epoxy, it was desirable to simplify the process and

E-Beam-Cured Layered-Silicate and Spherical Silica Epoxy Nanocomposites (Preprint)

DTIC Science & Technology

2007-03-01

Singh, A.; Janke, C.; Wrenn, G.; Havens, S . Radiat. Phys. Chem. 1999, 56, 405-415. 27. Korenev , S . Vacuum 2001, 62, 233-236 28. Crivello, J. V...TASK NUMBER RG 6. AUTHOR( S ) Chenggang Chen David P. Anderson 5f. WORK UNIT NUMBER M03R1000 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS...MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10. SPONSORING/MONITORING AGENCY ACRONYM( S ) AFRL-ML-WP Materials and Manufacturing Directorate Air Force

Simultaneous measurement of polymerization stress and curing kinetics for photo-polymerized composites with high filler contents.

PubMed

Wang, Zhengzhi; Landis, Forrest A; Giuseppetti, Anthony A M; Lin-Gibson, Sheng; Chiang, Martin Y M

2014-12-01

Photopolymerized composites are used in a broad range of applications with their performance largely directed by reaction kinetics and contraction accompanying polymerization. The present study was to demonstrate an instrument capable of simultaneously collecting multiple kinetics parameters for a wide range of photopolymerizable systems: degree of conversion (DC), reaction exotherm, and polymerization stress (PS). Our system consisted of a cantilever beam-based instrument (tensometer) that has been optimized to capture a large range of stress generated by lightly-filled to highly-filled composites. The sample configuration allows the tensometer to be coupled to a fast near infrared (NIR) spectrometer collecting spectra in transmission mode. Using our instrument design, simultaneous measurements of PS and DC are performed, for the first time, on a commercial composite with ≈80% (by mass) silica particle fillers. The in situ NIR spectrometer collects more than 10 spectra per second, allowing for thorough characterization of reaction kinetics. With increased instrument sensitivity coupled with the ability to collect real time reaction kinetics information, we show that the external constraint imposed by the cantilever beam during polymerization could affect the rate of cure and final degree of polymerization. The present simultaneous measurement technique is expected to provide new insights into kinetics and property relationships for photopolymerized composites with high filler content such as dental restorative composites. Published by Elsevier Ltd.

Simultaneous Measurement of Polymerization Stress and Curing Kinetics for Photo-polymerized Composites with High Filler Contents

PubMed Central

Wang, Zhengzhi; Landis, Forrest A.; Giuseppetti, Anthony A.M.; Lin-Gibson, Sheng; Chiang, Martin Y.M.

2015-01-01

Objectives Photopolymerized composites are used in a broad range of applications with their performance largely directed by reaction kinetics and contraction accompanying polymerization. The present study was to demonstrate an instrument capable of simultaneously collecting multiple kinetics parameters for a wide range of photopolymerizable systems: degree of conversion (DC), reaction exotherm, and polymerization stress (PS). Methods Our system consisted of a cantilever beam-based instrument (tensometer) that has been optimized to capture a large range of stress generated by lightly-filled to highly-filled composites. The sample configuration allows the tensometer to be coupled to a fast near infrared (NIR) spectrometer collecting spectra in transmission mode. Results Using our instrument design, simultaneous measurements of PS and DC are performed, for the first time, on a commercial composite with ≈ 80 % (by mass) silica particle fillers. The in situ NIR spectrometer collects more than 10 spectra per second, allowing for thorough characterization of reaction kinetics. With increased instrument sensitivity coupled with the ability to collect real time reaction kinetics information, we show that the external constraint imposed by the cantilever beam during polymerization could affect the rate of cure and final degree of polymerization. Significance The present simultaneous measurement technique is expected to provide new insights into kinetics and property relationships for photopolymerized composites with high filler content such as dental restorative composites. PMID:25443160

Epistemological beliefs and therapeutic health concepts of physiotherapy students and professionals.

PubMed

Bientzle, Martina; Cress, Ulrike; Kimmerle, Joachim

2014-10-01

Health knowledge develops fast and includes a lot of ambiguous or tentative information. In their daily routine, both health care students and professionals continuously have to make judgments about the viability of health knowledge. People's epistemological beliefs (EBs) and their therapeutic health concepts are factors that influence how they deal with health knowledge. However, very little is known about the occurrence of these factors at different stages of people's career. The present study examines the EBs and therapeutic health concepts of physiotherapy students in their vocational training and the EBs and therapeutic health concepts of professionals. In a cross-sectional study physiotherapy students and professional physiotherapists filled in a questionnaire that measured their personal EBs about physiotherapy and medicine, as well as their biomedical and biopsychosocial therapeutic health concepts. We compared the participants' EBs regarding both knowledge domains, and their therapeutic health concepts using paired samples t-tests. We also examined the differences between first-year students, advanced students, and professionals regarding their EBs and their therapeutic health concepts using ANOVAs. Eighty-three students and 84 professionals participated in this study, 114/167 (68%) participants were female. EBs as well as therapeutic health concepts differed depending upon the participants' training status. Professionals had more sophisticated EBs than students regarding both knowledge in physiotherapy (F(2, 164) = 6.74, P = 0.002, η(2)(p) = 0.08) and knowledge in medicine (F(2, 164) = 5.93, P = 0.003, η(2)(p) = 0.07). In addition, high values in a biopsychosocial therapeutic health concept already occurred in an early phase of training (F(2, 164) = 5.39, P = 0.005, η(2)(p) = 0.06), whereas increased values in a biomedical concept did not occur until people's professional life (F(2, 164) = 10.99, P < 0.001, η(2)(p) = 0.12). The specificities of personal EBs and therapeutic health concepts in different stages of health care training have so far been insufficiently considered in medical education research. The current study has aimed to shed light on the occurrence of these concepts in students as compared to professionals. We point out implications of our findings for educational practice and make suggestions for future research.

Integrating clinicians, knowledge and data: expert-based cooperative analysis in healthcare decision support

PubMed Central

2010-01-01

Background Decision support in health systems is a highly difficult task, due to the inherent complexity of the process and structures involved. Method This paper introduces a new hybrid methodology Expert-based Cooperative Analysis (EbCA), which incorporates explicit prior expert knowledge in data analysis methods, and elicits implicit or tacit expert knowledge (IK) to improve decision support in healthcare systems. EbCA has been applied to two different case studies, showing its usability and versatility: 1) Bench-marking of small mental health areas based on technical efficiency estimated by EbCA-Data Envelopment Analysis (EbCA-DEA), and 2) Case-mix of schizophrenia based on functional dependency using Clustering Based on Rules (ClBR). In both cases comparisons towards classical procedures using qualitative explicit prior knowledge were made. Bayesian predictive validity measures were used for comparison with expert panels results. Overall agreement was tested by Intraclass Correlation Coefficient in case "1" and kappa in both cases. Results EbCA is a new methodology composed by 6 steps:. 1) Data collection and data preparation; 2) acquisition of "Prior Expert Knowledge" (PEK) and design of the "Prior Knowledge Base" (PKB); 3) PKB-guided analysis; 4) support-interpretation tools to evaluate results and detect inconsistencies (here Implicit Knowledg -IK- might be elicited); 5) incorporation of elicited IK in PKB and repeat till a satisfactory solution; 6) post-processing results for decision support. EbCA has been useful for incorporating PEK in two different analysis methods (DEA and Clustering), applied respectively to assess technical efficiency of small mental health areas and for case-mix of schizophrenia based on functional dependency. Differences in results obtained with classical approaches were mainly related to the IK which could be elicited by using EbCA and had major implications for the decision making in both cases. Discussion This paper presents EbCA and shows the convenience of completing classical data analysis with PEK as a mean to extract relevant knowledge in complex health domains. One of the major benefits of EbCA is iterative elicitation of IK.. Both explicit and tacit or implicit expert knowledge are critical to guide the scientific analysis of very complex decisional problems as those found in health system research. PMID:20920289

Integrating clinicians, knowledge and data: expert-based cooperative analysis in healthcare decision support.

PubMed

Gibert, Karina; García-Alonso, Carlos; Salvador-Carulla, Luis

2010-09-30

Decision support in health systems is a highly difficult task, due to the inherent complexity of the process and structures involved. This paper introduces a new hybrid methodology Expert-based Cooperative Analysis (EbCA), which incorporates explicit prior expert knowledge in data analysis methods, and elicits implicit or tacit expert knowledge (IK) to improve decision support in healthcare systems. EbCA has been applied to two different case studies, showing its usability and versatility: 1) Bench-marking of small mental health areas based on technical efficiency estimated by EbCA-Data Envelopment Analysis (EbCA-DEA), and 2) Case-mix of schizophrenia based on functional dependency using Clustering Based on Rules (ClBR). In both cases comparisons towards classical procedures using qualitative explicit prior knowledge were made. Bayesian predictive validity measures were used for comparison with expert panels results. Overall agreement was tested by Intraclass Correlation Coefficient in case "1" and kappa in both cases. EbCA is a new methodology composed by 6 steps:. 1) Data collection and data preparation; 2) acquisition of "Prior Expert Knowledge" (PEK) and design of the "Prior Knowledge Base" (PKB); 3) PKB-guided analysis; 4) support-interpretation tools to evaluate results and detect inconsistencies (here Implicit Knowledg -IK- might be elicited); 5) incorporation of elicited IK in PKB and repeat till a satisfactory solution; 6) post-processing results for decision support. EbCA has been useful for incorporating PEK in two different analysis methods (DEA and Clustering), applied respectively to assess technical efficiency of small mental health areas and for case-mix of schizophrenia based on functional dependency. Differences in results obtained with classical approaches were mainly related to the IK which could be elicited by using EbCA and had major implications for the decision making in both cases. This paper presents EbCA and shows the convenience of completing classical data analysis with PEK as a mean to extract relevant knowledge in complex health domains. One of the major benefits of EbCA is iterative elicitation of IK.. Both explicit and tacit or implicit expert knowledge are critical to guide the scientific analysis of very complex decisional problems as those found in health system research.

Magnolol inhibits angiogenesis by regulating ROS-mediated apoptosis and the PI3K/AKT/mTOR signaling pathway in mES/EB-derived endothelial-like cells.

PubMed

Kim, Gi Dae; Oh, Jedo; Park, Hyen-Joo; Bae, Kihwan; Lee, Sang Kook

2013-08-01

Magnolol, a neolignan from the traditional medicinal plant Magnolia obovata, has been shown to possess neuroprotective, anti-inflammatory, anticancer and anti-angiogenic activities. However, the precise mechanism of the anti-angiogenic activity of magnolol remains to be elucidated. In the present study, the anti-angiogenic effect of magnolol was evaluated in mouse embryonic stem (mES)/embryoid body (EB)-derived endothelial-like cells. The endothelial-like cells were obtained by differentiation from mES/EB cells. Magnolol (20 µM) significantly suppressed the transcriptional and translational expression of platelet endothelial cell adhesion molecule (PECAM), an endothelial biomarker, in mES/EB-derived endothelial-like cells. To further understand the molecular mechanism of the suppression of PECAM expression, signaling pathways were analyzed in the mES/EB-derived endothelial-like cells. Magnolol induced the generation of reactive oxygen species (ROS) by mitochondria, a process that was associated with the induction of apoptosis as determined by positive Annexin V staining and the activation of cleaved caspase-3. The involvement of ROS generation by magnolol was confirmed by treatment with an antioxidant, N-acetyl-cysteine (NAC). NAC inhibited the magnolol-mediated induction of ROS generation and suppression of PECAM expression. In addition, magnolol suppressed the activation of MAPKs (ERK, JNK and p38) and the PI3K/AKT/mTOR signaling pathway in mES/EB-derived endothelial-like cells. Taken together, these findings demonstrate for the first time that the anti-angiogenic activity of magnolol may be associated with ROS-mediated apoptosis and the suppression of the PI3K/AKT/mTOR signaling pathway in mES/EB-derived endothelial-like cells.

Emotional Burnout, Perceived Sources of Job Stress, Professional Fulfillment, and Engagement among Medical Residents in Malaysia

PubMed Central

Al-Dubai, Sami Abdo Radman; Perianayagam, Wilson; Rampal, Krishna Gopal

2013-01-01

This study was the first to explore factors associated with emotional burnout (EB) among medical residents in Malaysia. A cross-sectional study was conducted in a universal sample of 205 medical residents in a Malaysian general hospital. The self-administered questionnaire used consisted of questions on sociodemographics and work characteristics, sources of job stress, professional fulfillment, engagement, and EB. EB was measured using the emotional exhaustion subscale, the Maslach Burnout Inventory (MBI). Mean (±SD) age of the respondents was 26.5 (±1.6). The most common source of job stress was “fear of making mistakes.” Most of the participants were dissatisfied with the increase of residentship period from one year to two years. A high level of EB was reported by 36.6% of the respondents. In multivariate analysis, the most important correlates of EB were sources of job stress, professional fulfillment, and engagement. A high prevalence of EB was found among medical residents. Sociodemographic characteristics, performance pressure, and satisfaction with policies were significantly associated with EB. Although this study was limited by its cross-sectional design, its findings posit a sufficient foundation to relevant authorities to construct, amend, and amalgamate existing and future policies. Nothing will sustain you more potently than the power to recognize in your humdrum routine, as perhaps it may be thought, the true poetry of life—the poetry of the common place, of the common man, of the plain, toil-worn woman, with their loves and their joys, their sorrows and their grief. SirWilliam Osler, Aphorisms from the Student Life (Aequanimitas, 1952) PMID:24367238

A case of IgG4-related lung disease complicated by asymptomatic chronic Epstein-Barr virus infection.

PubMed

Kotetsu, Yasuaki; Ikegame, Satoshi; Takebe-Akazawa, Keiko; Koga, Takaomi; Okabayashi, Kan; Takata, Shohei

2017-11-01

IgG4-related disease is characterized by IgG4-positive plasmacyte infiltration into various organs, but its etiology is not unknown. To elucidate the etiology of IgG4-related disease. We experienced an interesting case of IgG4-related lung disease complicated by chronic EB virus infection. A 70-year-old male visited our hospital due to failure of pneumonia treatment. Chest computed tomography (CT) showed consolidation in the right middle field and slight mediastinal lymphadenopathy in the subcarinal region. Lung consolidation improved with antibiotics; subcarinal lymphadenopathy progressed after 4 months. Malignant lymphoma was suspected given elevated sIL2-R levels (1862 U/mL). Patchy ground glass opacities appeared in the bilateral lung field just before surgical biopsy. He was diagnosed with IgG4-related lung disease after inspection of a pathological specimen obtained from the right upper lung and right hilar lymph node. EB virus-infected cells were also detected in the lymph node. Blood examination revealed EB virus viremia, but the patient did not present with symptoms or organ involvement. This led to a diagnosis of asymptomatic chronic EB virus infection. Recent studies have suggested an association between EB virus infection and IgG4-related diseases in the pathological exploration of surgically resected lymph nodes. Our case is the first case of IgG4-related lung disease in which EB virus infection was both pathologically and clinically proved. The present case is of particular interest in view of this newly reported association, and may serve as a fundamental report for future studies connecting EB virus infection with IgG4-related diseases. © 2016 John Wiley & Sons Ltd.

Effect of dietary manipulation on substrate flux and energy balance in obese women taking the appetite suppressant dexfenfluramine.

PubMed

Poppitt, S D; Swann, D L; Murgatroyd, P R; Elia, M; McDevitt, R M; Prentice, A M

1998-11-01

Studies in lean men show poor regulation of energy (EB) and fat balance (FB) during manipulation of dietary ratios of fat to carbohydrate. High-fat (HF), high-energy diets cause hyperphagia and a positive EB and FB. The protocol was designed to measure substrate flux and EB in obese women taking dexfenfluramine (DF) or placebo (PL) during an HF (50% of energy) or low-fat (25% of energy; LF) diet. We hypothesized that alterations in dietary fat would not be regulated and would lead to a positive EB and FB. The study was double-blind, randomized, and placebo-controlled, with 4 treatments (LF/DF, HF/DF, LF/PL, and HF/PL) and a crossover. Five days of continuous, whole-body calorimetry measurements were made in 6 subjects after 8 d of home DF/PL treatment. Macronutrient balance and EB were measured within the chamber as the cumulative difference between ad libitum intake and oxidation. The HF diet increased energy (HF, 10.50 MJ/d; LF, 8.13 MJ/d; P < 0.0001) and fat intakes (HF, 5.34 MJ/d; LF, 2.06 MJ/d; P < 0.0001), leading to a positive EB (delta = 2.37 MJ/d) and FB (delta = 2.31 MJ/d). DF reduced energy (DF, 8.96 MJ/d; PL, 9.66 MJ/d; P < 0.01) and macronutrient intakes, but did not increase energy expenditure (delta = -0.31 MJ/d; P < 0.01), or 24-h fat oxidation (delta = 0.03 MJ/d; P = 0.46). EB and FB are poorly regulated with HF, energy-dense diets in obese women, which leads to fat deposition and weight gain.

Free-Weight Augmentation With Elastic Bands Improves Bench Press Kinematics in Professional Rugby Players.

PubMed

García-López, David; Hernández-Sánchez, Sonsoles; Martín, Esperanza; Marín, Pedro J; Zarzosa, Fernando; Herrero, Azael J

2016-09-01

García-López, D, Hernández-Sánchez, S, Martín, E, Marín, PJ, Zarzosa, F, and Herrero, AJ. Free-weight augmentation with elastic bands improves bench press kinematics in professional rugby players. J Strength Cond Res 30(9): 2493-2499, 2016-This study aimed to investigate the effects of combining elastic bands to free weight resistance (EB + FWR) on the acceleration-deceleration and velocity profiles of the bench press in professional rugby players and recreationally trained subjects. Sixteen male subjects (8 rugby players and 8 recreationally trained subjects) were randomly assigned to complete 2 experimental conditions in a crossover fashion: EB + FWR and FWR. In both conditions, subjects performed 1 bench press set to volitional exhaustion with a load equivalent to the 85% of 1 repetition maximum (1RM). In the EB + FWR condition, the contribution of elastic resistance was approximately 20% of the selected load (85% 1RM). Results indicate that EB + FWR condition increased significantly the range of concentric movement in which the barbell is accelerated. This increase was significantly higher in rugby players (35%) in comparison with recreationally trained subjects (13%). Maximal velocity was also increased in EB + FWR (17%), when compared with FWR condition. These results suggest that when combined with variable resistance (i.e., EB), the external resistance seems to be more evenly distributed over the full range of motion, decreasing the need for dramatic deceleration at the end of the concentric phase. The present data also indicate that the kinematic benefits of an EB + FWR approach seems to be more prominent in athletes from modalities in which high level of strength and power are required (i.e., rugby players).

The interaction between temperament and the family environment in adolescent substance use and externalizing behaviors: Support for diathesis–stress or differential susceptibility?

PubMed Central

Rioux, Charlie; Castellanos-Ryan, Natalie; Parent, Sophie; Séguin, Jean R.

2016-01-01

Both individual and environmental factors predict externalizing behaviors and substance use (EB-SU); however, different patterns of interaction among these factors may have different implications. This review first examines how temperament and the family environment interact in the prediction of adolescent EB-SU. Second, studies are reviewed according to two theoretical models: (1) diathesis–stress, i.e., certain individual characteristics are linked to vulnerability and later problems in adverse environments; (2) differential susceptibility, i.e., these characteristics are linked to susceptibility, predicting problems in adverse environments, but also better than average outcomes in good environments. Fourteen studies focusing on the prediction of EB-SU at ages 12–18 were selected through a literature search. Results showed that certain temperament traits (high levels of impulsivity and disinhibition; low levels of effortful control, negative affect, fearfulness and shyness), hereby designated as “adventurous” disposition, were associated with higher levels of EB-SU in adverse family environments. Some studies also showed that children with “adventurous” temperament traits in positive environments had the lowest levels of EB-SU. This suggests that prevention of EB-SU might target family factors such as parenting and focus on children with “adventurous” temperament traits. Further, studies that supported the differential susceptibility model were those assessing temperament and the family environment in childhood and studies that supported the diathesis–stress model assessed these variables in adolescence. It is thus possible that some of these “adventurous” temperament traits, with regard to EB-SU, would be indicators of susceptibility to both enriched and adverse environments in childhood but no longer in adolescence, when they would only be indicators of vulnerability to adverse environments. PMID:27413247

Differential skeletal responses of hindlimb unloaded rats on a vitamin D-deficient diet to 1,25-dihydroxyvitamin D3 and its analog, seocalcitol (EB1089)

NASA Technical Reports Server (NTRS)

Narayanan, Ramesh; Allen, Matthew R.; Gaddy, Dana; Bloomfield, Susan A.; Smith, Carolyn L.; Weigel, Nancy L.

2004-01-01

Conditions of disuse in bed rest patients, as well as microgravity experienced by astronauts are accompanied by reduced mechanical loading, reduced calcium absorption, and lower serum levels of 1,25(OH)2D3 (1,25-D), the active metabolite of vitamin D, all contributing to bone loss. To determine whether 1,25-D or a less calcemic analog, Seocalcitol or EB1089 (1 alpha,25-dihydroxy-22,24-diene-24,26,27-trihomovitamin D3) can alleviate bone loss in a rat hindlimb unloading model of disuse osteopenia, mature male rats originally on a vitamin D replete diet containing 1.01% calcium were transferred to a vitamin D-deficient diet containing 0.48% calcium and then tail suspended and treated for 28 days with vehicle, 0.05 microg/kg 1,25-D, or 0.05 microg/kg EB1089. The vitamin D-deficient diet caused a substantial decrease in bone mineral density (-8%), which may be compounded by hindlimb unloading (-10%). Exogenous 1,25-D not only prevented the bone loss but also increased the bone mineral density to greater than the baseline level (+7%). EB1089 was less effective in preventing bone loss. Analysis of site and cell-specific effects of 1,25-D and EB1089 revealed that 1,25-D was more active than EB1089 in the intestine, the site of calcium absorption, and in inducing osteoclastogenesis and bone resorption whereas EB1089 was more effective in inducing osteoblast differentiation. These studies suggest that elevating circulating 1,25-D levels presumably increasing calcium absorption can counteract bone loss induced by disuse or microgravity with its associated reductions in circulating 1,25-D and decreased calcium absorption.

Use of a novel laparoscopic gastrostomy technique in children with severe epidermolysis bullosa.

PubMed

Patel, Kamlesh; Wells, Jonathan; Jones, Rosie; Browne, Fiona; Moss, Celia; Parikh, Dakshesh

2014-05-01

Supplementing nutrition in children with severe epidermolysis bullosa (EB) is challenging because of skin and mucosal fragility. Percutaneous endoscopic gastrostomy is contraindicated in EB, whereas more invasive open surgical gastrostomy placement can be complicated by chronic leakage. The aim of the study was to review the efficacy and acceptability, in children with severe EB, of our modified 2-port laparoscopic approach using the Seldinger technique with serial dilatation and tube insertion through a peel-away sheath. Retrospective review of children with EB who underwent laparoscopic feeding gastrostomy at our centre since 2009. Seven children (6 severe generalised recessive dystrophic EB, 1 non-Herlitz junctional EB; 2 girls, 5 boys) underwent modified laparoscopic gastrostomy placement at median age 4.85 years (range 1.0-8.8), with fundoplication for gastro-oesophageal reflux in 1 case, with follow-up for 0.3 to 3.9 years. The procedure was well tolerated with oral feeds usually given after 4 hours and whole protein gastrostomy feeds within 24 hours in 6 patients. Improved growth was reflected in mean weight and height z scores: -1.36 (range -2.6 to 0.5) to -0.61 (range -2.34 to 2.0) and -1.09 (range -2.42 to 1.0) to 0.71 (range -1.86 to 1.0), respectively. Postoperatively, 5 patients experienced minor local complications: minimal leakage without skin damage in 3 and transient peristomal granulation rapidly responsive to topical treatment in 2; this followed acute gastrostomy site infection in 1. There was no leakage after the immediate postoperative period. We conclude that our less-invasive laparoscopic gastrostomy technique is effective and better tolerated in children with severe EB, at least in the medium term, than open gastrostomy placement. Longer follow-up is required.

Adopting a Sustainable Community of Practice Model when Developing a Service to Support Patients with Epidermolysis Bullosa (EB): A Stakeholder-Centered Approach.

PubMed

Gowran, Rosemary Joan; Kennan, Avril; Marshall, Siobhán; Mulcahy, Irene; Ní Mhaille, Sile; Beasley, Sarah; Devlin, Mark

2015-02-01

Epidermolysis bullosa (EB) is a rare, genetic skin condition that is complicated, distressing, and painful and permeates every aspect of patients' lives. Support services are essential for meeting the primary needs of patients and families living with EB; however, provision is challenged by many complex issues. In collaboration with the patient organization DEBRA Ireland, this research conducted an in-depth analysis of Irish healthcare support services for EB, with a view to moving towards an improved and sustainable care pathway. A sustainable community of practice model (SCOP), as a core construct provided a simplified framework when studying this complex system. The research utilized mixed methods, comprising individual interviews, questionnaires, and a participatory action research workshop based on a soft systems approach. The study engaged patients, family members, service providers, and policy developers. Findings emphasized that the complexities of life with EB are more than 'skin deep'. The lived experience of stakeholders revealed many levels of emotion, both positive and heart-rending. Despite the positive efforts of specialists in this field, inadequacies to meet the primary needs of people with EB, such as bandages-fundamental for survival-were highlighted. Participants reported challenges relating to understanding patients' needs, access to consistent services within hospitals and the community, time constraints, and the strong emotions evoked by this severe and rare disease. The study identified several areas that can be targeted to bring about improvements in meeting primary needs. Education and research at public, policy, and practice levels need to be prioritized. It is imperative that citizens move beyond an awareness that EB exists and demonstrate a consciousness about the importance of advocating and enabling seamless and sustainable support services through collective action.

Radioligand Therapy of Prostate Cancer with a Long-Lasting Prostate-Specific Membrane Antigen Targeting Agent 90Y-DOTA-EB-MCG.

PubMed

Wang, Zhantong; Jacobson, Orit; Tian, Rui; Mease, Ronnie C; Kiesewetter, Dale O; Niu, Gang; Pomper, Martin G; Chen, Xiaoyuan

2018-06-15

Several radioligands targeting prostate-specific membrane antigen (PSMA) have been clinically introduced as a new class of radiotheranostics for the treatment of prostate cancer. Among them, ((( R)-1-carboxy-2-mcercaptoethyl)carbamoyl)-l-glutamic acid (MCG) has been successfully labeled with radioisotopes for prostate cancer imaging. The aim of this study is to conjugate MCG with an albumin binding moiety to further improve the in vivo pharmacokinetics. MCG was conjugated with an Evans blue (EB) derivative for albumin binding and a DOTA chelator. PSMA positive (PC3-PIP) and PSMA negative (PC3) cells were used for both in vitro and in vivo studies. Longitudinal PET imaging was performed at 1, 4, 24, and 48 h post-injection to evaluate the biodistribution and tumor uptake of 86 Y-DOTA-EB-MCG. DOTA-EB-MCG was also labeled with 90 Y for radionuclide therapy. Besides tumor growth measurement, tumor response to escalating therapeutic doses were also evaluated by immunohistochemistry and fluorescence microscopy. Based on quantification from 86 Y-DOTA-EB-MCG PET images, the tracer uptake in PC3-PIP tumors increased from 22.33 ± 2.39%ID/g at 1 h post-injection (p.i.), to the peak of 40.40 ± 4.79%ID/g at 24 h p.i. Administration of 7.4 MBq of 90 Y-DOTA-EB-MCG resulted in significant regression of tumor growth in PSMA positive xenografts. No apparent toxicity or body weight loss was observed in all treated mice. Modification of MCG with an Evans blue derivative resulted in a highly efficient prostate cancer targeting agent (EB-MCG), which showed great potential in prostate cancer treatment after being labeled with therapeutic radioisotopes.

The Functional Role of eL19 and eB12 Intersubunit Bridge in the Eukaryotic Ribosome.

PubMed

Kisly, Ivan; Gulay, Suna P; Mäeorg, Uno; Dinman, Jonathan D; Remme, Jaanus; Tamm, Tiina

2016-05-22

During translation, the two eukaryotic ribosomal subunits remain associated through 17 intersubunit bridges, five of which are eukaryote specific. These are mainly localized to the peripheral regions and are believed to stabilize the structure of the ribosome. The functional importance of these bridges remains largely unknown. Here, the essentiality of the eukaryote-specific bridge eB12 has been investigated. The main component of this bridge is ribosomal protein eL19 that is composed of an N-terminal globular domain, a middle region, and a long C-terminal α-helix. The analysis of deletion mutants demonstrated that the globular domain and middle region of eL19 are essential for cell viability, most likely functioning in ribosome assembly. The eB12 bridge, formed by contacts between the C-terminal α-helix of eL19 and 18S rRNA in concert with additional stabilizing interactions involving either eS7 or uS17, is dispensable for viability. Nevertheless, eL19 mutants impaired in eB12 bridge formation displayed slow growth phenotypes, altered sensitivity/resistance to translational inhibitors, and enhanced hyperosmotic stress tolerance. Biochemical analyses determined that the eB12 bridge contributes to the stability of ribosome subunit interactions in vitro. 60S subunits containing eL19 variants defective in eB12 bridge formation failed to form 80S ribosomes regardless of Mg(2+) concentration. The reassociation of 40S and mutant 60S subunits was markedly improved in the presence of deacetylated tRNA, emphasizing the importance of tRNAs during the subunit association. We propose that the eB12 bridge plays an important role in subunit joining and in optimizing ribosome functionality. Copyright © 2016 Elsevier Ltd. All rights reserved.