Decay of Rhenish Tuffs in Dutch Monuments. Part 2: Laboratory Experiments as a Basis for the Choice of Restoration Stone

Rhenish tuffs (Eifel, Germany), have been used as building material in the Netherlands since Roman times. They were the most important natural building stone in the Netherlands in early medieval times. In addition, tuff was used as raw material for production of trass, that served as a pozzolanic addition for mortars. Rhenish tuffs, notably...

Scintillation properties of O 1/spl times/1 Inch/sup 3/ LaBr/sub 3/: 5%Ce/sup 3+/ crystal

Thermal-neutron scintillator: Ce3+ activated Rb2LiYBr6

Scintillation and luminescence characteristics of Rb2LiYBr6 doped with 0.1%, 0.5%, 1%, and 5%?Ce3+ are presented. Under optical and x-ray excitation, Ce3+ doublet emission is observed at 385 and 420 nm. Rb2LiYBr6:0.5%?Ce3+ shows very high thermal neutron scintillation light output of 83?000 photons/neutron. An excellent neutron peak resolution...

Luminescence quenching by photoionization and electron transport in a LaAlO3:Ce3+ crystal

A combined photoconductivity, absorption, and thermoluminescence study was performed to understand the absence of luminescence from Ce3+ in LaAlO3:Ce3+. It is demonstrated that the absence of luminescence is the result of Ce3+ ionization from the 5d excited states, which are all located in the conduction band. Ce3+ ionization is accompanied by...

Advances in Yield Calibration of Scintillators

By means of a photomultiplier tube, a Si-photodiode, and a Si-avalanche photodiode, the absolute scintillation yield of recently developed LaBr3:Ce, LaCl3:Ce, and (Lu Y)2SiO5:Ce scintillators and traditional Lu2SiO5:Ce, Bi4Ge3O12, NaI:Tl CsI:Tl, and CsI:Na scintillators were determined. These are all well known scintillators that cover emission...

Li-Based Thermal Neutron Scintillator Research: Rb2LiYBr6 : Ce3+ and Other Elpasolites

Scintillation Properties of Praseodymium Activated Lu3Al5O12 Single Crystals

Scintillation properties of LuAG:Pr grown by Furukawa Co. Ltd., Japan, have been studied. The best crystals display light outputs up to 19000 ph/MeV and an energy resolution of 4.6% at 662 keV. The scintillation yield is found to be a function of size and temperature of the sample; it can be enhanced by 40% upon heating to 450 K....

High-energy radiation monitoring based on radio-fluorogenic co-polymerization. I: Small volume in situ probe

A method of radiation dosimetry is described which is based on the radiation-induced initiation of polymerization of a bulk monomer (e.g. methyl methacrylate) containing a small concentration (about 100 ppm) of a compound which is non-fluorescent but which becomes highly fluorescent when it is incorporated into a growing polymer chain of the...

In-situ radiation dosimetry based on Radio-Fluorogenic Co-Polymerization

A fluorimetric method of radiation dosimetry is presented for which the intensity of the fluorescence of a (tissue equivalent) medium is linearly dependent on accumulated dose from a few Gray up to kiloGrays. The method is based on radio-fluorogenic co-polymerization (RFCP) in which a normally very weakly fluorescent molecule becomes highly...

Improvement of ?-ray energy resolution of LaBr3:Ce3+ scintillation detectors by Sr2+ and Ca2+ co-doping

Commercially available LaBr3:5% Ce3+ scintillators show with photomultiplier tube readout about 2.7% energy resolution for the detection of 662?keV ?-rays. Here we will show that by co-doping LaBr3:Ce3+ with Sr2+ or Ca2+ the resolution is improved to 2.0%. Such an improvement is attributed to a strong reduction of the scintillation light losses...

33000 photons per MeV from mixed (Lu0.75Y0.25)3Al5O12:Pr scintillator crystals

(LuxY1-x)3Al5O12:Pr (x = 0.25, 0.50, 0.75) crystals have been grown by the Czochralski method and their scintillation properties have been examined. Compared to the well-respected LuAG:Pr scintillator, which has so extensively been studied in the recent years, the new mixed LuYAG:Pr crystals display markedly higher light yields, regardless of...

An active heat tracer experiment to determine groundwater velocities using fiber optic cables installed with direct push equipment

A new approach is developed to insert fiber optic cables vertically into the ground with direct push equipment. Groundwater temperatures may be measured along the cables with high spatial and temporal resolution using a Distributed Temperature Sensing system. The cables may be inserted up to depths of tens of meters in unconsolidated sedimentary...

Source tracking of Enterococcus moraviensis and E. haemoperoxidus

Enterococciwere detected occasionally in 100 L samples ofwater abstracted froma shallowaquifer in a natural dune infiltration area for drinking water production. Enterococcus moraviensis was the species most frequently identified in these samples. Because there are no existing reports of faecal sources of E. moraviensis and the closely...

Tuning the Structural Rigidity of Two-Dimensional Ruddlesden-Popper Perovskites through the Organic Cation

Two-dimensional (2D) hybrid organic-inorganic perovskites are an interesting class of semi-conducting materials. One of their main advantages is the large freedom in the nature of the organic spacer molecules that separates the individual inorganic layers. The nature of the organic layer can significantly affect the structure and dynamics of...

Debris-flow activity and sediment dynamics in the landslide-influenced Lattenbach catchment, Austria

Deep seated landslides are common phenomena in Alpine areas. In case of a direct connectivity with the channel system, the catchment' s sediment yield and the probability of other forms of mass wasting processes such as debris flows may be increased significantly. Up to now, sediment dynamics related to deep-seated landslides and debris flows...

State-of-the-art of Longitudinal Travel Surveys - A Comparison of the MOP and MPN

Longitudinal travel surveys are needed to capture individual travel behaviour changes. Only two longitudinal tavel surveys of national relevance are currently in operation, the German Mobility Panel (MOP) since 1994 and the Netherlands Mobility Panel (MPN) since 2013. This paper provides an overview of both panels' differences and...