scholarly journals Study on the Causes of Secondary Cracks of the Eave Wall Mural of Daxiong Hall at Fengguo Temple in Yixian, Liaoning, China

2021 ◽  
Author(s):  
Cheng Liu ◽  
Yuan He ◽  
Qian Li ◽  
Fei Wang
Keyword(s):  
Three Dimensional ◽  
Laser Scanner ◽  
Liaoning Province ◽  
Structural Defects ◽  
Thermal Imager ◽  
Secondary Cracks ◽  
Liao Dynasty ◽  
The Stability ◽  
Infrared Thermal Imager

Abstract Built in Kaitai nine years of Liao Dynasty (1020 A.D.), the Daxiong Hall of Fengguo Temple in Yixian County, Liaoning Province, is one of the largest existing ancient single-eave wooden structure in China. There are nearly 470m 2 murals of Yuan Dynasty on the four walls of the hall. Since the in-situ reinforcement and protection of the mural were carried out in the 1980s in cooperation with the maintenance and restoration project of the main hall, the seriously developed cracks have become the primary factor affecting the structural stability of the mural. In order to find out the macroscopic causes of secondary cracks, endoscope, infrared thermal imager, three-dimensional laser scanner and other equipment were applied to study the relations between cracks’ attitude and structural defects of the eave wall, as well as the pathway that external environment act on the mural noumenon through comprehensive investigation, and the idea of restoring the stability of the mural by blocking the air channel and offsetting the environmental stress is put forward.

scholarly journals Study on the causes of secondary cracks of the eave wall mural of Daxiong Hall at Fengguo Temple in Yixian, Liaoning, China

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Cheng Liu ◽  
Yuan He ◽  
Qian Li ◽  
Fei Wang
Keyword(s):  
Three Dimensional ◽  
Laser Scanner ◽  
Digital Camera ◽  
Structural Features ◽  
Liaoning Province ◽  
Thermal Imager ◽  
Environmental Monitoring System ◽  
Secondary Cracks ◽  
World Cultural Heritage ◽  
The Yuan Dynasty

AbstractBuilt in Kaitai 9 years after the beginning of the Liao Dynasty (1020 A.D.), the Daxiong Hall of Fengguo Temple (Yixian County, Liaoning Province) is one of China’s largest existing ancient single-eave wooden architecture structures. In 2012, it was listed on the “Preliminary List of World Cultural Heritage in China.” Preserved Buddhist murals depicting the Yuan Dynasty cover approximately 470 m2 of the hall’s four walls. Since the in-situ reinforcement and protection of the mural, conducted in the 1980s in cooperation with the maintenance and restoration project of the main hall, seriously developed cracks—known as secondary cracks—have become a primary factor affecting the mural’s structural stability. In this study, we conducted a comprehensive investigation using a full-frame digital camera, an industrial endoscope, an infrared thermal imager, an online environmental monitoring system, and a three-dimensional laser scanner. Our results, and other relevant materials, allowed us to deepen our understanding of the existing structural features, the nature of the cracks, the deformation conditions, and the environmental characteristics of the mural. Moreover, we provide a further discussion on the macroscopic formation process of the secondary cracks.

Handheld Laser Scanner Research

2019 ◽  
Vol 952 (10) ◽  
pp. 47-54
Author(s):  
A.V. Komissarov ◽  
A.V. Remizov ◽  
M.M. Shlyakhova ◽  
K.K. Yambaev
Keyword(s):  
Point Cloud ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Test Site ◽  
Optical Systems ◽  
Advantages And Disadvantages ◽  
Site Survey ◽  
Laser Scanners ◽  
Three Dimensional Models ◽  
The Stability

The authors consider hand-held laser scanners, as a new photogrammetric tool for obtaining three-dimensional models of objects. The principle of their work and the newest optical systems based on various sensors measuring the depth of space are described in detail. The method of simultaneous navigation and mapping (SLAM) used for combining single scans into point cloud is outlined. The formulated tasks and methods for performing studies of the DotProduct (USA) hand-held laser scanner DPI?8X based on a test site survey are presented. The accuracy requirements for determining the coordinates of polygon points are given. The essence of the performed experimental research of the DPI?8X scanner is described, including scanning of a test object at various scanner distances, shooting a test polygon from various scanner positions and building point cloud, repeatedly shooting the same area of the polygon to check the stability of the scanner. The data on the assessment of accuracy and analysis of research results are given. Fields of applying hand-held laser scanners, their advantages and disadvantages are identified.

scholarly journals Assessment of Tuff Sea Cliff Stability Integrating Geological Surveys and Remote Sensing. Case History from Ventotene Island (Southern Italy)

2020 ◽  
Vol 12 (12) ◽  
pp. 2006 ◽  
Author(s):  
Ruberti Daniela ◽  
Marino Ermanno ◽  
Pignalosa Antonio ◽  
Romano Pasquale ◽  
Vigliotti Marco
Keyword(s):  
3D Model ◽  
Risk Mitigation ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Fracture Network ◽  
Integrated Analysis ◽  
South Italy ◽  
The Stability ◽  
Data Acquisition And Processing ◽  
Sea Cliff

This study provides a detailed integrated analysis of the erosional processes affecting the volcanoclastic headlands of a pocket beach, of a typical Tyrrhenian volcanic island (Ventotene, south Italy). It compares the survey carried out in 2012 and the recent landslides that occurred in 2018–2020. The studied tuff cliff is characterised by steep, up to overhanging walls affected by a fracture network, which locally isolates blocks in precarious equilibrium. The stability conditions of the southern Cala Nave Bay sea cliff were evaluated by integrating a geological field survey, structural analysis of discontinuities, and a detailed topographic survey consisting of a terrestrial laser scanner (TLS) and photogrammetry data acquisition and processing, providing a three-dimensional (3D) model of the sea cliff. The 3D model of the area affected by the recent landslides was created using proximity photogrammetry, the Structure for Motion (SfM) methodology. The fracture network was represented by using high-resolution digital models and projected to realize geostructural vertical mapping of the cliff. The data acquired in 2012 were more recently compared with further surveys carried out, following rock failures that occurred in winter 2019–2020. The detachment planes and failure modalities coincide perfectly with the ones previously assessed. The applied techniques and the comparison with the recent rock failures have proven to be important in defining these conditions to address risk mitigation interventions.

Closure of a Nuclear Waste Repository Deeply Imbedded in a Stratified Salt Bed

1994 ◽  
Vol 116 (4) ◽  
pp. 567-573 ◽  
Author(s):  
Wei Xu ◽  
Joseph Genin
Keyword(s):  
Triaxial Compression ◽  
Three Dimensional ◽  
Element Model ◽  
Nuclear Waste Repository ◽  
Relaxation Functions ◽  
Dimensional Finite Element ◽  
Set Up ◽  
The Stability ◽  
Three Dimensional Finite Element

The Waste Isolation Pilot Plant (WIPP) is a repository vault, mined deep into a salt strata. It eventually closes in on itself, encapsulating its contents. At room temperature salt may be regarded as a linear, isotropic, viscoelastic material. In this study, using triaxial compression test results on salt, we determine the relaxation functions and set up the boundary value problem for the encapsulation mechanism of a salt vault. Closure of the repository as a function of time is determined using a three-dimensional finite element model. The Tresca failure criterion is used to predict the stability of the repository. Finally, the study is validated by comparing our results to in-situ measured data.

Quality of Reamed Surface Using Serrated Blades as Compared to a Conventional Acetabular Reamer

2013 ◽  
Author(s):  
Annie Levasseur ◽  
Jérémie Ménard ◽  
Victor Songmené ◽  
Julio Fernandes ◽  
Yvan Petit
Keyword(s):  
Experimental Testing ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Numerical Control ◽  
Long Term Stability ◽  
Surface Irregularities ◽  
The Stability ◽  
Acetabular Implant

Background: Hip arthroplasty requires the preparation of the acetabular cavity to allow a proper contact between the bone and the implant. It is essential to allow osseointegration and long-term stability of the implant. The aim of this study was to conduct experimental testing to evaluate the quality of reamed surfaces using a serrated blade acetabular reamer as compared to a conventional rasp reamer. Method of Approach: Reaming tests were performed on a computerized numerical control tools machine at a rotational speed of 250 rpm and 3 different penetration speeds: 0.20 mm/s, 0.55 mm/s and 0.90 mm/s. For each reamer, a complete semi-hemispherical hole was perforated in 7 polyurethane samples. The reamed surfaces were digitized with a three-dimensional high resolution (40 μm) self-positioning laser scanner to carry out a quantitative analysis of the surface quality. Results: Results demonstrated that the cutting edge and the penetration speed influence the quality of the reamed surface. The serrated blade was found to reduce surface irregularities (ranging between 0.19 mm to 0.21 mm for the conventional rasp and between 0.07 mm and 0.12 mm for the serrated blades), and to reduce inaccuracies on the reamed cavity diameter (0.13 mm ± 0.05mm for the rasps and 0.06 mm ± 0.03mm for the serrated blade). Conclusions: The use of such tool by the surgeon may influence the stability of the acetabular implant and reduce the risks of revision surgery.

scholarly journals Impact of the Mining Dimensions on the Stability of Backfilled Pier-Columns

2021 ◽  
Vol 11 (20) ◽  
pp. 9640
Author(s):  
Jianlin Xie ◽  
Weibing Zhu ◽  
Jialin Xu ◽  
Xiaozhen Wang ◽  
Limin Wang
Keyword(s):  
Physical Simulation ◽  
Three Dimensional ◽  
Field Testing ◽  
Mining Areas ◽  
Working Face ◽  
Physical Experiments ◽  
Mining Width ◽  
The Stability ◽  
The Impact

Owing to alternate mining of the new and old mining areas on sites, the mining thickness and width of the working face for pier-column backfilling varies. Thus, there is an urgent need to determine the impact on the bearing performance of the backfilled pier-column after changing the mined dimensions. This study consisted of three-dimensional numerical simulations, physical experiments, and field testing. These methods were performed to study the impact on the stability of the backfilled pier-column after changing the dimensions of the working face. The numerical and physical simulation results revealed that the mining thickness has a greater impact on the stability of the backfilled pier-columns than the width. Field testing results proved that the designed parameters for the backfilled pier-column in situ satisfy the bearing requirements; thus, it can effectively support the overlying strata of the goaf after mining. When increasing the mining thickness, the stress borne by the pier-column increased, and its stability decreased. Upon increasing the mining width, the variation in the stress exerted onto the pier-column was remarkably small, and the change of the elastoplastic zone of the pier-column was also minimal.

scholarly journals In-situ multi-analytical study of ongoing corrosion processes on bronze artworks exposed outdoor

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 241
Author(s):  
Leila Es Sebar ◽  
Leonardo Iannucci ◽  
Caterina Gori ◽  
Alessandro Re ◽  
Marco Parvis ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Three Dimensional ◽  
Corrosion Products ◽  
Invasive Approach ◽  
Non Invasive ◽  
Combined Use ◽  
Art Collection ◽  
The Stability ◽  
Microclimate Conditions

<p class="Abstract">This paper presents a long-term in-situ campaign to monitor contemporary bronze statuary exposed outdoors. The case study relates to the characterisation of three sculptures belonging to the Gori Art Collection, located in the Fattoria di Celle: ‘Cavaliere’ and ‘Miracolo – Composizione’ by Marino Marini and ‘Due forme o due ombre n°2’ by Luciano Minguzzi. The overall conservation state of the sculptures was investigated by means of a multi-analytical and non-invasive approach, involving different techniques. Three-dimensional photogrammetry was performed to fully document the artworks. The chemical and microstructural features of the corrosion patinas were then characterised through X-ray fluorescence and Raman spectroscopy. In addition, the stability and the protective effectiveness of the corrosion products were assessed by electrochemical impedance spectroscopy. Thanks to the combined use of these specific techniques, the information extracted through the different analyses could be correlated with each other and with the exposure conditions. The different corrosion products were identified as being primarily copper sulphates and phosphates, and they were correlated with the different microclimate conditions related to their location on the statues. The information gathered from the presented multi-analytical approach represents the fundamental knowledge required to develop a tailored conservation project to assure the long-lasting preservation of these artworks.</p>

scholarly journals The Influence Mechanism of In Situ Stress State on the Stability of Deep-Buried-Curved Tunnel in Qinghai-Tibet Plateau and Its Adjacent Region

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Huiqing Wang ◽  
Chengxuan Tan ◽  
Chengjun Feng ◽  
Peng Zhang ◽  
Bangshen Qi ◽  
...  
Keyword(s):  
Stress State ◽  
Pressure Coefficient ◽  
Three Dimensional ◽  
Multivariate Regression Analysis ◽  
In Situ Stress ◽  
Tibet Plateau ◽  
Adjacent Region ◽  
The Stability ◽  
Qinghai Tibet Plateau

In China, rockburst disaster occurs mostly in construction of underground engineering in Qinghai-Tibet Plateau and its adjacent region. Previous research on deep-buried tunnels has indicated that tunnels stability is related to in situ stress state. To quantify these relationships, three-dimensional finite element modeling was done to analyze the influences that the angle φ between the maximum horizontal principal stress orientation and tunnel axis, and the lateral pressure coefficient KH, had on the tangential stress σ θ in a deep-buried-curved tunnel. Based on the in situ stress condition in Qinghai-Tibet Plateau and its adjacent region, 50 different simulation conditions were used to analyze the relationship that φ and KH had on σ θ for the rock mass surrounding the tunnel. With the simulation data produced, predictive equations were generated for σ θ as a function of φ and KH using multivariate regression analysis. These equations help estimate σ θ at various key positons along the tunnel boundary at Qinghai-Tibet plateau and its adjacent region. The equations were then proved by a set of typical tunnels to ensure validity. The results concluded that the change in φ has a significant impact on σ θ , and thus, the stability of the tunnel, when 30° < φ < 60°, with the most obvious influence being when φ is about 45°. With the equations, the rockburst potential at a certain location within a curved tunnel can be quickly estimated by calculating φ and KH on σ θ , without need of geo-stress background knowledge and heavy simulation, allowing for the practical value in engineering at design phase for the projects in Qinghai-Tibet Plateau and its adjacent region.

Correlated Studies of Cellular Interactions Using TEM, Freeze Etching, and SEM

1974 ◽  
Vol 32 ◽  
pp. 320-321
Author(s):  
J. P. Revel
Keyword(s):  
Developmental Stages ◽  
Three Dimensional ◽  
Cell Movement ◽  
Cellular Interactions ◽  
Serial Sections ◽  
Cell Sheets ◽  
Freeze Etching ◽  
Early Developmental

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

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