Dual Band Infrared Thermography as a NDT Tool for the Characterization of the Building Materials and Conservation Performance in Historic Structures

1999 ◽  
Vol 591 ◽  
Author(s):  
A. Moropoulou ◽  
N.P. Avdelidis ◽  
M. Koui ◽  
N.K. Kanellopoulos

ABSTRACTInfrared thermography is a non-destructive investigation technique, which is largely used because of the outstanding advantages that it is capable to provide in a variety of applications and especially for conservation purposes of historic monuments, where destructive sectioning is prohibited. In the present work, dual band infrared thermography (3–5.4 μm and 8–12 μpm) is used, to evaluate the humidity distribution by capillary rise in reference samples of porous materials in lab, in order to validate the examination of real scale material systems in situ. The combined study of vapor/moisture transport in prototypes simulating porous materials under controlled environmental conditions (Relative Humidity 60–80% & Temperature 25–40°C), provides interpretation tools to the investigation by IR Thermography of transport phenomena occurring at the masonry. The cross-investigation of consolidated porous stones and of repair mortars, in lab and in situ on historic monuments in Greece, permits to evaluate the performance of conservation materials, regarding their compatibility to the porous building stones on historic masonries. It is deduced that Infrared Thermography by recording thermal maps of the real surfaces under study provides information on the differential behavior of the various materials on the masonry scale regarding the water impregnation and evaporation phenomena, which control the weathering effects in porous media. Hence, infrared thermography might be used as a nondestructive technique to evaluate on a micro and macro scale the performance of conservation interventions and materials, in compatibility to the original materials on the level of the structures.

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3935 ◽  
Author(s):  
Zbigniew Suchorab ◽  
Marcin Widomski ◽  
Grzegorz Łagód ◽  
Danuta Barnat-Hunek ◽  
Dariusz Majerek

The article presents the potential application of the time domain reflectometry (TDR) technique to measure moisture transport in unsaturated porous materials. The research of the capillary uptake phenomenon in a sample of autoclaved aerated concrete (AAC) was conducted using a TDR sensor with the modified construction for non-invasive testing. In the paper the basic principles of the TDR method as a technique applied in metrology, and its potential for measurement of moisture in porous materials, including soils and porous building materials are presented. The second part of the article presents the experiment of capillary rise process in the AAC sample. Application of the custom sensor required its individual calibration, thus a unique model of regression between the readouts of apparent permittivity of the tested material and its moisture was developed. During the experiment moisture content was monitored in the sample exposed to water influence. Monitoring was conducted using the modified TDR sensor. The process was additionally measured using the standard frequency domain (FD) capacitive sensor in order to compare the readouts with traditional techniques of moisture detection. The uncertainty for testing AAC moisture, was expressed as RMSE (0.013 cm3/cm3) and expanded uncertainty (0.01–0.02 cm3/cm3 depending on moisture) was established along with calibration of the applied sensor. The obtained values are comparable to, or even better than, the features of the traditional invasive sensors utilizing universal calibration models. Both, the TDR and capacitive (FD) sensor enabled monitoring of capillary uptake phenomenon progress. It was noticed that at the end of the experiment the TDR readouts were 4.4% underestimated and the FD readouts were overestimated for 12.6% comparing to the reference gravimetric evaluation.


2014 ◽  
Vol 19 (1-2) ◽  
pp. 97-107 ◽  
Author(s):  
Zbigniew Suchorab ◽  
Marcin K. Widomski ◽  
Grzegorz Łagód ◽  
Danuta Barnat-Hunek ◽  
Piotr Smarzewski

Abstract The article presents the description of measurement methodology of moisture transport in unsaturated porous materials using Time Domain Reflectometry (TDR) technique on the example of measurement of capillary uptake phenomenon in the sample of autoclaved aerated concrete (AAC). In the paper there are presented basic principles of the TDR method as a technique applied in metrology, its potential for measurement of moisture in porous materials like soils and porous building materials. Second part of the article presents the experiment of capillary rise process in the sample of AAC. Within the experiment moisture content was monitored in the sample exposed on water influence. Monitoring was conducted using TDR FP/mts probes. Preparation of the measuring setup was presented in detail. The TDR readouts post-processing, graphical presentations of the obtained results, short discussion and comparison of TDR readouts to gravimetric measurement were also presented.


Author(s):  
Barbara Trask ◽  
Susan Allen ◽  
Anne Bergmann ◽  
Mari Christensen ◽  
Anne Fertitta ◽  
...  

Using fluorescence in situ hybridization (FISH), the positions of DNA sequences can be discretely marked with a fluorescent spot. The efficiency of marking DNA sequences of the size cloned in cosmids is 90-95%, and the fluorescent spots produced after FISH are ≈0.3 μm in diameter. Sites of two sequences can be distinguished using two-color FISH. Different reporter molecules, such as biotin or digoxigenin, are incorporated into DNA sequence probes by nick translation. These reporter molecules are labeled after hybridization with different fluorochromes, e.g., FITC and Texas Red. The development of dual band pass filters (Chromatechnology) allows these fluorochromes to be photographed simultaneously without registration shift.


2018 ◽  
Vol 44 (18) ◽  
pp. 22904-22910 ◽  
Author(s):  
Guo Feng ◽  
Feng Jiang ◽  
Weihui Jiang ◽  
Jianmin Liu ◽  
Quan Zhang ◽  
...  

2018 ◽  
Author(s):  
Robert Reinecke ◽  
Laura Foglia ◽  
Steffen Mehl ◽  
Tim Trautmann ◽  
Denise Cáceres ◽  
...  

Abstract. To quantify water flows between groundwater (GW) and surface water (SW) as well as the impact of capillary rise on evapotranspiration by global hydrological models (GHMs), it is necessary to replace the bucket-like linear GW reservoir model typical for hydrological models with a fully integrated gradient-based GW flow model. Linear reservoir models can only simulate GW discharge to SW bodies, provide no information on the location of the GW table and assume that there is no GW flow among grid cells. A gradient-based GW model simulates not only GW storage but also hydraulic head, which together with information on SW table elevation enables the quantification of water flows from GW to SW and vice versa. In addition, hydraulic heads are the basis for calculating lateral GW flow among grid cells and capillary rise. G3M is a new global gradient-based GW model with a spatial resolution of 5' that will replace the current linear GW reservoir in the 0.5° WaterGAP Global Hydrology Model (WGHM). The newly developed model framework enables in-memory coupling to WGHM while keeping overall runtime relatively low, allowing sensitivity analyses and data assimilation. This paper presents the G3M concept and specific model design decisions together with results under steady-state naturalized conditions, i.e. neglecting GW abstractions. Cell-specific conductances of river beds, which govern GW-SW interaction, were determined based on the 30'' steady-state water table computed by Fan et al. (2013). Together with an appropriate choice for the effective elevation of the SW table within each grid cell, this enables a reasonable simulation of drainage from GW to SW such that, in contrast to the GW model of de Graaf et al. (2015, 2017), no additional drainage based on externally provided values for GW storage above the floodplain is required in G3M. Comparison of simulated hydraulic heads to observations around the world shows better agreement than de Graaf et al. (2015). In addition, G3M output is compared to the output of two established macro-scale models for the Central Valley, California, and the continental United States, respectively. As expected, depth to GW table is highest in mountainous and lowest in flat regions. A first analysis of losing and gaining rivers and lakes/wetlands indicates that GW discharge to rivers is by far the dominant flow, draining diffuse GW recharge, such that lateral flows only become a large fraction of total diffuse and focused recharge in case of losing rivers and some areas with very low GW recharge. G3M does not represent losing rivers in some dry regions. This study presents the first steps towards replacing the linear GW reservoir model in a GHM while improving on recent efforts, demonstrating the feasibility of the approach and the robustness of the newly developed framework.


Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1416 ◽  
Author(s):  
Mohamed Haouas

The employment of nuclear magnetic resonance (NMR) spectroscopy for studying crystalline porous materials formation is reviewed in the context of the development of in situ methodologies for the observation of the real synthesis medium, with the aim of unraveling the nucleation and growth processes mechanism. Both liquid and solid state NMR techniques are considered to probe the local environment at molecular level of the precursor species either soluble in the liquid phase or present in the reactive gel. Because the mass transport between the liquid and solid components of the heterogeneous system plays a key role in the synthesis course, the two methods provide unique insights and are complementary. Recent technological advances for hydrothermal conditions NMR are detailed and their applications to zeolite and related materials crystallization are illustrated. Achievements in the field are exemplified with some representative studies of relevance to zeolites, aluminophosphate zeotypes, and metal-organic frameworks.


2018 ◽  
Vol 165 ◽  
pp. 04005
Author(s):  
Yi Shi ◽  
Xiaoguang Yang ◽  
Guolei Miao ◽  
Duoqi Shi

This essays aims at introducing the setup for the multi-scale in-situ test system which is applied for the fatigue crack initiation test. The setup of the experiment system is first introduced, including the image capturing system, optical path system, image acquisition and storage system and the three-axis mobile platform. Then the preparation of micro speckle and the corresponding technique for spatial adjustment are improved to realize the DIC measurement in micro scale. Finally three experiments from macro-meso scale to macro scale: fatigue initiation test, the observation of micro crack and the fatigue crack growth rate in macro scale were conducted to verify the application of the system. The test result can indicate the location of crack initiation, the crack growth rate and the evolution of displacement/strain field, etc.


2019 ◽  
Vol 3 ◽  
pp. 140-149 ◽  
Author(s):  
Alexis Simons ◽  
Alexandra Bertron ◽  
Christophe Roux ◽  
Aurélie Laborel-Préneron ◽  
Jean-Emmanuel Aubert ◽  
...  

The impact of building materials on the environment and the health of occupants is nowadays a priority issue. Ecological construction materials such as earthen materials are currently experiencing a regain of interest due to both ecological and economic factors. The microbial proliferation on indoor materials can induce a deterioration of the building air quality and lead to an increase of health risks for the occupants. The issue of indoor air quality raises questions about the use of earthen building materials and their possible susceptibility to fungal development. The microflora of earthen materials and their ability to grow on such support are indeed poorly studied. This study focused on the quantification of both bacterial and fungal microflora along the manufacturing process. The impact of extreme humidity, simulating a hydric accident, on microflora development was analyzed on the surface and inside earthen bricks. The initial microflora of these materials was dramatically reduced during the manufacturing process, especially after heat treatment for drying. Proliferation of remaining microorganisms was only observed under high humidity condition, in particular for earthen materials with vegetal aggregates. Moreover, in situ samplings were performed on naturally dried earthen materials used in buildings. The characterization of the microbial density revealed a higher microbial density than on manufactured specimens, while microbial concentration and detected taxa seemed mainly related to the room use and building history. These results provide a better understanding of microbial proliferation on these materials.


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