scholarly journals Analyzing Near-Surface Regions of Hydrophobic and Long-Term Weathered Natural Stones at Microscopic Scale

Heritage ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 457-473
Author(s):  
Franziska Braun ◽  
Jeanette Orlowsky ◽  
Stefan Brüggerhoff
Keyword(s):  
Structural Changes ◽  
Color Difference ◽  
Outdoor Exposure ◽  
Material Surface ◽  
Building Structures ◽  
Near Surface ◽  
Visual Appearance ◽  
Microscopic Scale ◽  
Surface Damages

The visual appearance of building structures is an important attribute which reflects the character and identity of a region. Due to the influence of weathering, the surfaces of building stones alter, leading to aesthetic changes of the material surface such as discoloration or darkening. In this study, near-surface regions of weathered Baumberger (BST), Schleeriether (SST), and Obernkirchener Sandstones (OKS) have been analyzed at the microscopic scale in order to investigate the intensity and the extent of visual as well as structural changes and how both can be affected due to the presence of surface treatments with hydrophobing agents. It could be detected that aesthetic changes appeared already after 2 years of outdoor exposure, with the slightest variations on BST surfaces, followed by SST and OKS. The use of hydrophobing agents leads to a reduction in surface darkening in the short term. After long-term weathering, no significant changes are visible, as similar values in total color difference (ΔE*) were measured. Biogenic growth and the formation of black weathering crusts are the main reasons for color alterations in the case of the examined stones. The surface damages occur especially on calcareous (BST) followed by clayey (SST) and quartzitic (OKS) stone surfaces.

Large Bore Catheters with Surface Treatments versus Untreated Catheters for Blood Access

2001 ◽  
Vol 2 (3) ◽  
pp. 97-105 ◽  
Author(s):  
R. Bambauer ◽  
P. Mestres ◽  
R. Schiel ◽  
J.M. Schneidewind-Müller ◽  
S. Bambauer ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Bulk Material ◽  
Bacterial Colonization ◽  
Ion Beam ◽  
Surface Region ◽  
Material Surface ◽  
Near Surface ◽  
Treatment Processes ◽  
Infection Resistance

Infection, thrombosis, and stenosis are among the most frequent complications associated with blood contacting catheters. Because these problems are usually related to surface properties of the base catheter material, surface treatment processes, such as ion implantation and ion beam assisted deposition (IBAD) (silver based coatings), can be used to mitigate such complications. Because these ion beam based processes affect only the near-surface region (approximately the outer 1 μm), there is little effect on bulk material properties. This study evaluated silver coated and implanted large bore catheters used for extracorporeal detoxification. In a 186 patient prospective study, 225 large bore catheters were inserted into the internal jugular or subclavian veins. 85 surface treated catheters (Spi-Argent, Spire Corporation, Bedford, MA-USA; n=39 acute catheters, n= 46 long-term catheters) and 28 catheters with surface treatment (Spi-Silicone, Spire Corporation, Bedford, MA-USA) were inserted in 90 patients. 112 untreated catheters placed in 96 patients served as controls (n = 62 acute catheters, n = 58 long-term catheters). After removal, the catheters were cultured for bacterial colonization using standard microbiologic assays. They also were examined using a scanning electron microscope (SEM). Bacterial colonization was observed in 8% of the treated catheters compared with 46.4% of untreated catheters. The SEM investigations showed all treated catheters to possess low thrombogenicity. Results of the study indicate that ion beam based processes can be used to improve thrombus and infection resistance of blood contacting catheters.

Shot Peening - A New Method for Improving Mechanical Properties of Structural Ceramics

2006 ◽  
Vol 317-318 ◽  
pp. 277-280 ◽  
Author(s):  
Henryk Tomaszewski ◽  
K. Godwod ◽  
Ryszard Diduszko ◽  
F. Carrois ◽  
J.M. Duchazeaubeneix
Keyword(s):  
Compressive Stress ◽  
Shot Peening ◽  
Structural Changes ◽  
Treatment Time ◽  
Surface Region ◽  
Microplastic Deformation ◽  
Material Surface ◽  
Near Surface ◽  
Compressive Stresses ◽  
Ultrasonic Shot Peening

Shot peening is commonly used to modify material surface layers and improve the strength of metal components. As it occurred the same technique can be applied for brittle ceramics. High compressive stresses up to 2.4 GPa were introduced into near surface region of alumina and zirconia ceramics by ultrasonic shot peening maintaining its surface integrity. Dependence between diameter of tungsten balls, treatment time (at constant mass of balls in the housing and vibration amplitude) and level of compressive stress introduced was determined for both ceramics with nano and micrograins. Coarser grained ceramics was found to be more sensible to structural changes responsible for stress creation than the smaller one. High microplastic deformation in shot peened surface layer of ceramics was observed by X-ray diffraction. An increase of hardness and surface resistance to fracture with increasing level of compressive stress was found.

Influence of the Conditional Release of the Materials With Very Low Level of Radioactivity on the Environment

2011 ◽  
Author(s):  
Slavka Prvakova ◽  
Adela Mrskova ◽  
Jozef Pritrsky
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Computer Code ◽  
Recycled Concrete ◽  
Building Structures ◽  
Conditional Release ◽  
Near Surface ◽  
Low Level ◽  
Analytical Approaches

Significant amount of solid materials (metals, non-metals, building structures) that could be contaminated or activated is produced during operation and especially decommissioning of nuclear power plants. Considerable fraction of these materials has level of radioactivity close to the radiological limits allowing its safe release into the environment thereby could be potentially recycled within the special constructions, as for example tunnels, roads or bridges. If the requirements of legislation on the radiological limits for handling such material and long-term safety of the constructions are met, contaminated material can be incorporated in the form of recycled concrete, remelted steel, etc. The paper presents implementation of the IAEA and EC recommendations into the form of detailed analytical approaches with the aim to develop integrated scenarios and to analyse long-term influence of the conditional release of the material with very low level of radioactivity on the environment. Further, an estimation of the key input parameters characteristic for the specific conditions of Slovak case in order to fulfil the radiological limits according to the Slovak legislation is included. Analysed integrated scenarios represent surface or underground civil construction with radionuclides released directly into the geosphere and transported by a groundwater flow to the biosphere. The migration of radionuclides is modelled in the near-surface conditions with the advection as a dominant transport mechanism. Computer code GoldSim is used to evaluate the long-term safety assessment of the conditionally released material on the environment.

Coming Together Through Falling Apart

2019 ◽  
Vol 40 (2) ◽  
pp. 151-168
Author(s):  
Heather Churchill ◽  
Jeremy M. Ridenour
Keyword(s):  
Data Analysis ◽  
Qualitative Data ◽  
Structural Changes ◽  
Systematic Approach ◽  
Qualitative Approach ◽  
Psychological Assessments ◽  
Transference And Countertransference ◽  
Testing Data ◽  
Psychoanalytically Oriented Psychotherapy

Abstract. Assessing change during long-term psychotherapy can be a challenging and uncertain task. Psychological assessments can be a valuable tool and can offer a perspective from outside the therapy dyad, independent of the powerful and distorting influences of transference and countertransference. Subtle structural changes that may not yet have manifested behaviorally can also be assessed. However, it can be difficult to find a balance between a rigorous, systematic approach to data, while also allowing for the richness of the patient’s internal world to emerge. In this article, the authors discuss a primarily qualitative approach to the data and demonstrate the ways in which this kind of approach can deepen the understanding of the more subtle or complex changes a particular patient is undergoing while in treatment, as well as provide more detail about the nature of an individual’s internal world. The authors also outline several developmental frameworks that focus on the ways a patient constructs their reality and can guide the interpretation of qualitative data. The authors then analyze testing data from a patient in long-term psychoanalytically oriented psychotherapy in order to demonstrate an approach to data analysis and to show an example of how change can unfold over long-term treatments.

Economic Institutions and Growth Nexus: The Role of Governance and Democratic Institutions—Evidence from Time Varying Parameters’ (TVPs) Models

2016 ◽  
Vol 55 (4I-II) ◽  
pp. 675-688
Author(s):  
Ghulam Murtaza ◽  
Muhammad Zahir Faridi
Keyword(s):  
Structural Changes ◽  
Jel Classification ◽  
Economic Institutions ◽  
Time Varying ◽  
Democratic Institutions ◽  
Main Hypothesis ◽  
Dynamic Relationship ◽  
Rolling Window

The present study has investigated the channels through which the linkage between economic institutions and growth is gauged, by addressing the main hypothesis of the study that whether quality of governance and democratic institutions set a stage for economic institutions to promote the long-term growth process in Pakistan. To test the hypothesis empirically, our study models the dynamic relationship between growth and economic institutions in a time varying framework in order to capture institutional developments and structural changes occurred in the economy of Pakistan over the years. Study articulates that, along with some customary specifics, the quality of government and democracy are the substantial factors that affect institutional quality and ultimately cause to promote growth in Pakistan. JEL Classification: O40; P16; C14; H10 Keywords: Economic Institutions, Growth, Governance and Democracy, Rolling Window Two-stage Least Squares, Pakistan

Individual differences in white and grey matter structure associated with verbal habits of thought

2019 ◽  
Author(s):  
Justin C. Hayes ◽  
Katherine L Alfred ◽  
Rachel Pizzie ◽  
Joshua S. Cetron ◽  
David J. M. Kraemer
Keyword(s):  
Individual Differences ◽  
White Matter ◽  
Cognitive Processing ◽  
Grey Matter ◽  
Structural Changes ◽  
Structural Integrity ◽  
Diffusion Tensor ◽  
Self Report ◽  
White Matter Tracts

Modality specific encoding habits account for a significant portion of individual differences reflected in functional activation during cognitive processing. Yet, little is known about how these habits of thought influence long-term structural changes in the brain. Traditionally, habits of thought have been assessed using self-report questionnaires such as the visualizer-verbalizer questionnaire. Here, rather than relying on subjective reports, we measured habits of thought using a novel behavioral task assessing attentional biases toward picture and word stimuli. Hypothesizing that verbal habits of thought are reflected in the structural integrity of white matter tracts and cortical regions of interest, we used diffusion tensor imaging and volumetric analyses to assess this prediction. Using a whole-brain approach, we show that word bias is associated with increased volume in several bilateral language regions, in both white and grey matter parcels. Additionally, connectivity within white matter tracts within an a priori speech production network increased as a function of word bias. These results demonstrate long-term structural and morphological differences associated with verbal habits of thought.

Structural changes in the metal of welded joints of long-term operating steam pipelines

2020 ◽  
Vol 2020 (2) ◽  
pp. 24-28
Author(s):  
V.V. Dmytryk ◽  
◽  
. A.V. Glushko ◽  
S.P. Iglin ◽  
◽  
...  
Keyword(s):  
Welded Joints ◽  
Structural Changes ◽  
Operating Steam

scholarly journals Non-Local and Multi-Scale Mechanisms for Image Inpainting

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3281
Author(s):  
Xu He ◽  
Yong Yin
Keyword(s):  
Markov Random Fields ◽  
Receptive Fields ◽  
Image Inpainting ◽  
Long Distance ◽  
Visual Appearance ◽  
Fine Grained ◽  
Multi Scale ◽  
Non Local ◽  
Relationship Of

Recently, deep learning-based techniques have shown great power in image inpainting especially dealing with squared holes. However, they fail to generate plausible results inside the missing regions for irregular and large holes as there is a lack of understanding between missing regions and existing counterparts. To overcome this limitation, we combine two non-local mechanisms including a contextual attention module (CAM) and an implicit diversified Markov random fields (ID-MRF) loss with a multi-scale architecture which uses several dense fusion blocks (DFB) based on the dense combination of dilated convolution to guide the generative network to restore discontinuous and continuous large masked areas. To prevent color discrepancies and grid-like artifacts, we apply the ID-MRF loss to improve the visual appearance by comparing similarities of long-distance feature patches. To further capture the long-term relationship of different regions in large missing regions, we introduce the CAM. Although CAM has the ability to create plausible results via reconstructing refined features, it depends on initial predicted results. Hence, we employ the DFB to obtain larger and more effective receptive fields, which benefits to predict more precise and fine-grained information for CAM. Extensive experiments on two widely-used datasets demonstrate that our proposed framework significantly outperforms the state-of-the-art approaches both in quantity and quality.

scholarly journals Most Frequent Problems of Building Structures of Urban Apartment Buildings from 2nd Half of 19th Century and the Start of 20th Century

Buildings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 27
Author(s):  
Klara Kroftova
Keyword(s):  
20Th Century ◽  
19Th Century ◽  
Residential Building ◽  
Structural Safety ◽  
Horizontal Load ◽  
Building Structures ◽  
Speed Up ◽  
The 19Th Century ◽  
Basic Prerequisite

An urban residential building from the second half of the 19th century and the start of the 20th century, the so-called tenement house, is a significant representative of the architecture of the developing urban fabric in Central Europe. The vertical and horizontal load-bearing structures of these houses currently tend to show characteristic, repeated defects and failures. Their knowledge may, in many cases, facilitate and speed up the design of the historic building’s restoration without compromising its heritage value in this process. The article presents the summary of the most frequently occurring defects and failures of these buildings. The summary, however, is not an absolute one, and, in the case of major damage to the building, it still applies that, first of all, a detailed analysis of the causes and consequences of defects and failures must be made as a basic prerequisite for the reliability and long-term durability of the building’s restoration and rehabilitation. An integral part of the rehabilitation of buildings must be the elimination of the causes of the appearance of their failures and remediation of all defects impairing their structural safety, health safety and energy efficiency.

Long-term performance of zeolite Na A-X blend as backfill material in near surface disposal vault

2009 ◽  
Vol 149 (1-3) ◽  
pp. 143-152 ◽  
Author(s):  
R.O. Abdel Rahman ◽  
H.A. Ibrahim ◽  
N.M. Abdel Monem
Keyword(s):  
Near Surface ◽  
Backfill Material ◽  
Long Term Performance ◽  
Term Performance
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