Search results for "GLASS"

showing 10 items of 1153 documents

An In Vitro Stereomicroscopic Evaluation of Bioactivity between Neo MTA Plus, Pro Root MTA, BIODENTINE & Glass Ionomer Cement Using Dye Penetrati…

2021

The ideal root end filling material should form a tight seal in the root canal by adhering to the cavity walls. Several materials have been used for root end filling. The present study aims to find out and compare the bioactivity of Neo MTA Plus, Pro Root MTA White, BIODENTINE & glass ionomer cement as root end filling materials using 1% methylene blue as tracer. Materials and methods: 80 extracted human permanent maxillary anterior teeth were used in the study. They were divided into four groups. Specimens were sectioned transversely in the cervical area to separate the crown from the root. The root canal was obturated with gutta percha and zinc oxide eugenol sealers. Thereafter, each …

Dye penetrationTechnologyRoot end fillingRoot canalmedicine.medical_treatmentGlass ionomer cementDentistryArticleCrown (dentistry)030207 dermatology & venereal diseases03 medical and health scienceschemistry.chemical_compound0302 clinical medicineStereo microscopemedicineGeneral Materials ScienceAnterior teethMicroscopyQC120-168.85biologyChemistrybusiness.industryTQH201-278.5030206 dentistryGutta-perchaEngineering (General). Civil engineering (General)biology.organism_classificationTK1-9971medicine.anatomical_structureDescriptive and experimental mechanicsDye penetrationStereomicroscopeMTAZinc oxide eugenolBIODENTINEElectrical engineering. Electronics. Nuclear engineeringTA1-2040businessMaterials
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Sealing ability of five different retrograde filling materials.

1996

The sealing ability of Amalgam, Harvard-Cement, Diaket, gold-leaf, and Ketac-Endo as retrofilling materials was investigated. Paper cones were fixed with Harvard-Cement in the instrumented roots of 100 extracted human incisors. Apicectomy was performed and a 2-mm-deep retrograde cavity was prepared. Teeth were assigned to five groups (n = 20); each group received a different filling material. Surfaces of the roots were isolated with nail polish. Teeth, were stored in 1% methylene blue dye for 72 h. Roots were sectioned, and the depth of dye penetration was evaluated through a stereomicroscope. Retrofills with Ketac-Endo showed significantly less leakage compared with amalgam. There was no s…

Dye penetrationZinc Phosphate CementMaterials scienceDentistryMandibleGold foilDental AmalgamApicectomyStatistics NonparametricRoot Canal Filling Materialsstomatognathic systemIncisorStereo microscopemedicineMaxillaHumansGeneral DentistryDental Leakagebusiness.industrySignificant differencetechnology industry and agricultureIncisorstomatognathic diseasesDrug Combinationsmedicine.anatomical_structureFilling materialsEvaluation Studies as TopicGlass Ionomer CementsRetrograde ObturationPolyvinylsZinc OxidebusinessBismuthZinc Phosphate CementJournal of endodontics
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Dielectric relaxation models applied of the dynamics of myoglobin as determined by Mössbauer spectroscopy

1996

Abstract Protein specific modes of motions are found in myoglobin crystals above 180 K. In this contribution we show that this type of motions can be analyzed by a Davidson-Cole, a Cole-Cole or a Havriliak-Negami distribution in analogy to dielectric relaxation. However, the temperature dependence of the obtained parameters is quite unusual indicating a broadening of the distributions with temperature instead of motional narrowing. This can be understood from the picture of conformational substates if one assumes that more and more substates become accessible with increasing temperature. The result shows that the analogy between glass forming organic liquids and proteins should not be exagg…

Dynamics (mechanics)General Physics and AstronomyDielectricGlass formingchemistry.chemical_compoundNuclear magnetic resonanceMyoglobinchemistryChemical physicsMössbauer spectroscopyRelaxation (physics)Organic liquidsPhysical and Theoretical ChemistryMotional narrowingChemical Physics
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Luminescence of gamma-radiation-induced defects in alpha-quartz

2004

Optical transitions associated with gamma-radiation-induced defects in crystalline a-quartz were investigated by photoluminescence excited by both pulsed synchrotron radiation and steady-state light. After a 10 MGy gamma-dose we observed two emissions at 4.9 eV (ultraviolet band) and 2.7 eV (blue band) excitable in the range of the induced absorption band at 7.6 eV. These two luminescence bands show a different temperature dependence: the ultraviolet band becomes bright below 80 K; the blue band increases below 180 K, but drops down below 80 K. Both emissions decay in a timescale of a few ns under pulsed excitation, however the blue band could also be observed in slow recombination processe…

ELECTRON-PARAMAGNETIC-RESONANCEAMORPHOUS-SILICON DIOXIDEOPTICAL-ABSORPTIONGLASSESSYNTHETIC SILICAPHOTOLUMINESCENCESIO2BANDOXYGEN-DEFICIENT CENTERSIRRADIATION
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Suppressive Efficacy by a Commercially Available Blue Lens on PPR in 610 Photosensitive Epilepsy Patients

2006

Purpose Photosensitivity can represent a serious problem in epilepsy patients, also because pharmacologic treatment is often ineffective. Nonpharmacologic treatment using blue sunglasses is effective and safe in controlling photosensitivity, but large series of patients have never been studied. Methods This multicenter study was conducted in 12 epilepsy centers in northern, central, southern, and insular Italy. A commercially available lens, named Z1, obtained in a previous trial, was used to test consecutively enrolled pediatric and adult epilepsy patients with photosensitivity. Only type 4 photosensitivity (photoparoxysmal response, PPR) was considered in the study. A standardized method …

EPILEPSY-PHOTOSENSITIVE-BLUE GLASSES-NONPHARMACOLOGICAdultMalemedicine.medical_specialtyAdolescentEpilepsy ReflexPharmacological treatmentCentral nervous system diseaseEpilepsyPhotosensitive epilepsyInternal medicineFemale patientmedicineHumansPractice Patterns Physicians'ChildAgedbusiness.industryVideotape RecordingLarge seriesElectroencephalographyMiddle Agedmedicine.diseaseTREATMENT-PHOTOPAROXYSMAL RESPONSE-PPRSurgeryClinical trialTreatment OutcomeItalyNeurologyMulticenter studyChild PreschoolAnticonvulsantsFemaleNeurology (clinical)PHOTOSENSITIVEEye Protective DevicesbusinessColor PerceptionPhotic StimulationEpilepsia
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Watch glasses exposed to 6 MV photons and 10 MeV electrons analysed by means of ESR technique

2011

ESR dosimetry watch glasses electrons photonsSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)
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ESR study of proton irradiation response of watch glasses.

2009

ESR dosimetry watch glassesSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)
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Preliminary application of thermoluminescence and single aliquot regeneration method for dose reconstruction in soda lime glass

2013

The research described in this paper shows that the use of the single aliquot regeneration (SAR) method for thermoluminescence (TL) measurements applied to soda lime glasses allows to carry out a retrospective dose evaluation. We have followed a fast and efficient sample preparation procedure which permits measurements without powdering and sieving processes. We have analyzed the TL signal of commercial soda lime watch glass irradiated with 6 Mega Volts (MV) LINAC photons, 10 MeV LINAC electrons and 62 MeV protons. After the initial exposure and following TL reading, the samples are successively irradiated with increasing doses of photons. Therefore, for each sample its calibration curve is…

Electron beamSoda-lime glassNuclear and High Energy PhysicsMaterials scienceThermoluminescenceCalibration curveRadiochemistryMineralogyThermoluminescenceProton beamchemistry.chemical_compoundSoda limechemistrySoda lime watch glasseCathode rayPhoton beamSample preparationIrradiationSingle aliquot regeneration methodWatch glassInstrumentationNuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
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Photosensitivity of SiO2–Al and SiO2–Na glasses under ArF (193 nm) laser

2009

Abstract Photosensitivity of SiO 2 –Al and SiO 2 –Na glass samples was probed by means of the induced optical absorption and luminescence as well as by electron spin-resonance (ESR) after irradiation with excimer-laser photons (ArF, 193 nm). Permanent visible darkening in the case of SiO 2 –Al and transient, life time about one hour, visible darkening in the case of SiO 2 –Na was found under irradiation at 290 K. No darkening was observed at 80 K for either kind of material. This investigation is dedicated to revealing the electronic processes responsible for photosensitivity at 290 and 80 K. The photosensitivity of both materials is related to impurity defects excited directly in the case …

Electron mobilityPhotoluminescenceChemistryDopingAnalytical chemistryCondensed Matter PhysicsElectronic Optical and Magnetic MaterialsPhotosensitivityImpurityMaterials ChemistryCeramics and CompositesIrradiationRadiation effects Glasses Laser–matter interactions Optical spectroscopy Defects Optical properties Absorption Lasers Luminescence Photoinduced effects Time resolved measurements Oxide glasses Alkali silicates Aluminosilicates Silica Silicates Radiation Electron spin resonanceSpectroscopyLuminescence
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EPR on Radiation-Induced Defects in SiO2

2014

Continuous-wave electron paramagnetic resonance (EPR) spectroscopy has been the technique of choice for the studies of radiation-induced defects in silica (SiO2) for 60 years, and has recently been expanded to include more sophisticated techniques such as high-frequency EPR, pulse electron nuclear double resonance (ENDOR), and pulse electron spin echo envelope modulation (ESEEM) spectroscopy. Structural models of radiation-induced defects obtained from single-crystal EPR analyses of crystalline SiO2 (alfa-quartz) are often applicable to their respective analogues in amorphous silica (a-SiO2), although significant differences are common.

Electron nuclear double resonanceMaterials sciencePulse (signal processing)Settore FIS/01 - Fisica SperimentaleRadiation inducedOxygen vacancylaw.inventionNuclear magnetic resonancelawSingle-crystal and glass EPR multi-frequency EPR pulse ENDOR pulse ESEEM coordinate system oxygen vacancy silicon vacancy impurity defects electronic structures dynamic propertiesAmorphous silicaElectron paramagnetic resonanceSpectroscopyEnvelope (waves)
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