Étude de la pénétrabilité du coulis de ciment microfin sous pression dans les structures de maçonnerie dégradées à caractère historique : effet d'un agent colloïdal

Several masonry structures, built over the past centuries, have to be restored to ensure their structural integrity and their conservation. Important research and development projects have been initiated by Public Works and Government Services Canada to rehabilitate some of these structures, such as the Rideau canal locks, by using a cement-based grouting technique. By following grouting pressures and flow rates, the stability of the structure is protected and the efficiency to fill openings is assured by using microfine cement-based grouts with admixtures. However, cement grout penetration cannot be observed with precision during the injection. The project described in this paper presents the grouting treatment of a Rideau canal lock sill wall that had to be demolished and reconstructed. The penetration of two different grout mixes was observed by removing the front row of blocks, piece by piece. A second phase of this study was conducted in the laboratory to compare the penetration of different grouts in a reconstructed granular material which simulated the lock's interior walls.Key words: restoration, masonry, grouting, groutability, cement grout, colloidal agent.

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Destabilizing the Structural Integrity of SARS-CoV2 Receptor Proteins by Curcumin Along with Hydroxychloroquine: An Insilco Approach for a Combination Therapy

10.26434/chemrxiv.12090438.v1 ◽

2020 ◽

Cited By ~ 1

Author(s):

Akhileshwar Srivastava ◽

Divya Singh

Keyword(s):

Binding Energy ◽

Combination Therapy ◽

Receptor Binding ◽

Structural Integrity ◽

Binding Domain ◽

Receptor Binding Domain ◽

Receptor Proteins ◽

Main Protease ◽

The Stability ◽

Therapeutic Activities

Presently, an emerging disease (COVID-19) has been spreading across the world due to coronavirus (SARS-CoV2). For treatment of SARS-CoV2 infection, currently hydroxychloroquine has been suggested by researchers, but it has not been found enough effective against this virus. The present study based on in silico approaches was designed to enhance the therapeutic activities of hydroxychloroquine by using curcumin as an adjunct drug against SARS-CoV2 receptor proteins: main-protease and S1 receptor binding domain (RBD). The webserver (ANCHOR) showed the higher protein stability for both receptors with disordered score (<0.5). The molecular docking analysis revealed that the binding energy (-24.58 kcal/mol) of hydroxychloroquine was higher than curcumin (-20.47 kcal/mol) for receptor main-protease, whereas binding energy of curcumin (<a>-38.84</a> kcal/mol) had greater than hydroxychloroquine<a> (-35.87</a> kcal/mol) in case of S1 receptor binding domain. Therefore, this study suggested that the curcumin could be used as combination therapy along with hydroxychloroquine for disrupting the stability of SARS-CoV2 receptor proteins

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Stability and Folding of the Unusually Stable Hemoglobin from Synechocystis is Subtly Optimized and Dependent on the Key Heme Pocket Residues.

Protein and Peptide Letters ◽

10.2174/0929866527666200613220245 ◽

2020 ◽

Vol 27 ◽

Author(s):

Sheetal Uppal ◽

Mohd. Asim Khan ◽

Suman Kundu

Keyword(s):

Molten Globule ◽

Life Forms ◽

Model System ◽

Heme Pocket ◽

The Past ◽

Specific Manner ◽

Delivery Vehicles ◽

The Stability ◽

Key Residues ◽

Synechocystis Sp

Aims: The aim of our study is to understand the biophysical traits that govern the stability and folding of Synechocystis hemoglobin, a unique cyanobacterial globin that displays unusual traits not observed in any of the other globins discovered so far. Background: For the past few decades, classical hemoglobins such as vertebrate hemoglobin and myoglobin have been extensively studied to unravel the stability and folding mechanisms of hemoglobins. However, the expanding wealth of hemoglobins identified in all life forms with novel properties, like heme coordination chemistry and globin fold, have added complexity and challenges to the understanding of hemoglobin stability, which has not been adequately addressed. Here, we explored the unique truncated and hexacoordinate hemoglobin from the freshwater cyanobacterium Synechocystis sp. PCC 6803 known as “Synechocystis hemoglobin (SynHb)”. The “three histidines” linkages to heme are novel to this cyanobacterial hemoglobin. Objective: Mutational studies were employed to decipher the residues within the heme pocket that dictate the stability and folding of SynHb. Methods: Site-directed mutants of SynHb were generated and analyzed using a repertoire of spectroscopic and calorimetric tools. Result: The results revealed that the heme was stably associated to the protein under all denaturing conditions with His117 playing the anchoring role. The studies also highlighted the possibility of existence of a “molten globule” like intermediate at acidic pH in this exceptionally thermostable globin. His117 and other key residues in the heme pocket play an indispensable role in imparting significant polypeptide stability. Conclusion: Synechocystis hemoglobin presents an important model system for investigations of protein folding and stability in general. The heme pocket residues influenced the folding and stability of SynHb in a very subtle and specific manner and may have been optimized to make this Hb the most stable known as of date. Other: The knowledge gained hereby about the influence of heme pocket amino acid side chains on stability and expression is currently being utilized to improve the stability of recombinant human Hbs for efficient use as oxygen delivery vehicles.

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Copper Phyllosilicates-Derived Catalysts in the Production of Alcohols from Hydrogenation of Carboxylates, Carboxylic Acids, Carbonates, Formyls, and CO2: A Review

Catalysts ◽

10.3390/catal11020255 ◽

2021 ◽

Vol 11 (2) ◽

pp. 255

Author(s):

Dien-Thien To ◽

Yu-Chuan Lin

Keyword(s):

Carboxylic Acids ◽

Catalytic Performance ◽

Spatial Effect ◽

Synthesis Methods ◽

The Past ◽

Surface Areas ◽

Preparation Conditions ◽

Remedial Actions ◽

The Stability ◽

Size Interaction

Copper phyllosilicates-derived catalysts (CuPS-cats) have been intensively explored in the past two decades due to their promising activity in carbonyls hydrogenation. However, CuPS-cats have not been completely reviewed. This paper focuses on the aspects concerning CuPS-cats from synthesis methods, effects of preparation conditions, and dopant to catalytic applications of CuPS-cats. The applications of CuPS-cats include the hydrogenation of carboxylates, carboxylic acids, carbonates, formyls, and CO2 to their respective alcohols. Besides, important factors such as the Cu dispersion, Cu+ and Cu0 surface areas, particles size, interaction between Cu and supports and dopants, morphologies, and spatial effect on catalytic performance of CuPS-cats are discussed. The deactivation and remedial actions to improve the stability of CuPS-cats are summarized. It ends up with the challenges and prospective by using this type of catalyst.

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Assessment of the Use of Humidified Nasal Cannulas for Oxygen Therapy in Patients with Epistaxis

ORL ◽

10.1159/000514460 ◽

2021 ◽

pp. 1-5

Author(s):

Jingjing Liu ◽

Tengfang Chen ◽

Zhenggang Lv ◽

Dezhong Wu

Keyword(s):

Flow Rate ◽

Oxygen Therapy ◽

Preliminary Investigation ◽

Nasal Cannula ◽

Low Flow ◽

Antiplatelet Drugs ◽

Flow Rates ◽

The Past ◽

Oxygen Inhalation ◽

Significant Difference

Introduction: In China, nasal cannula oxygen therapy is typically humidified. However, it is difficult to decide whether to suspend nasal cannula oxygen inhalation after the nosebleed has temporarily stopped. Therefore, we conducted a preliminary investigation on whether the use of humidified nasal cannulas in our hospital increases the incidence of epistaxis. Methods: We conducted a survey of 176,058 inpatients in our hospital and other city branches of our hospital over the past 3 years and obtained information concerning their use of humidified nasal cannulas for oxygen inhalation, nonhumidified nasal cannulas, anticoagulant and antiplatelet drugs, and oxygen inhalation flow rates. This information was compared with the data collected at consultation for epistaxis during these 3 years. Results: No significant difference was found between inpatients with humidified nasal cannulas and those without nasal cannula oxygen therapy in the incidence of consultations due to epistaxis (χ2 = 1.007, p > 0.05). The same trend was observed among hospitalized patients using anticoagulant and antiplatelet drugs (χ2 = 2.082, p > 0.05). Among the patients with an inhaled oxygen flow rate ≥5 L/min, the incidence of ear-nose-throat (ENT) consultations due to epistaxis was 0. No statistically significant difference was found between inpatients with a humidified oxygen inhalation flow rate <5 L/min and those without nasal cannula oxygen therapy in the incidence of ENT consultations due to epistaxis (χ2 = 0.838, p > 0.05). A statistically significant difference was observed in the incidence of ENT consultations due to epistaxis between the low-flow nonhumidified nasal cannula and nonnasal cannula oxygen inhalation groups (χ2 = 18.428, p < 0.001). The same trend was observed between the 2 groups of low-flow humidified and low-flow nonhumidified nasal cannula oxygen inhalation (χ2 = 26.194, p < 0.001). Discussion/Conclusion: Neither high-flow humidified nasal cannula oxygen inhalation nor low-flow humidified nasal cannula oxygen inhalation will increase the incidence of recurrent or serious epistaxis complications; the same trend was observed for patients who use anticoagulant and antiplatelet drugs. Humidification during low-flow nasal cannula oxygen inhalation can prevent severe and repeated epistaxis to a certain extent.

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Thermodynamic and Energy Efficiency Analysis of a Domestic Refrigerator Using Al2O3 Nano-Refrigerant

Sustainability ◽

10.3390/su13105659 ◽

2021 ◽

Vol 13 (10) ◽

pp. 5659

Author(s):

Farhood Sarrafzadeh Javadi ◽

Rahman Saidur

Keyword(s):

Temperature Gradient ◽

Technological Changes ◽

Nanoparticle Concentration ◽

Evaporator Temperature ◽

Domestic Refrigerator ◽

The Past ◽

Nano Lubricant ◽

The Stability ◽

Energy Efficiency Analysis ◽

Al2o3 Nanofluid

Refrigeration systems have experienced massive technological changes in the past 50 years. Nanotechnology can lead to a promising technological leap in the refrigeration industry. Nano-refrigerant still remains unknown because of the complexity of the phase change process of the mixture including refrigerant, lubricant, and nanoparticle. In this study, the stability of Al2O3 nanofluid and the performance of a nano-refrigerant-based domestic refrigerator have been experimentally investigated, with the focus on the thermodynamic and energy approaches. It was found that by increasing the nanoparticle concentration, the stability of nano-lubricant was decreased and evaporator temperature gradient was increased. The average of the temperature gradient increment in the evaporator was 20.2% in case of using 0.1%-Al2O3. The results showed that the energy consumption of the refrigerator reduced around 2.69% when 0.1%-Al2O3 nanoparticle was added to the system.

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Tuned Mass Damper Design for Slender Masonry Structures: A Framework for Linear and Nonlinear Analysis

Applied Sciences ◽

10.3390/app11083425 ◽

2021 ◽

Vol 11 (8) ◽

pp. 3425

Author(s):

Marco Zucca ◽

Nicola Longarini ◽

Marco Simoncelli ◽

Aly Mousaad Aly

Keyword(s):

Nonlinear Analysis ◽

Linear Time ◽

Design Procedure ◽

Time History ◽

Tuned Mass Damper ◽

Second Phase ◽

Masonry Structures ◽

Base Shear ◽

Mass Damper ◽

Linear And Nonlinear

The paper presents a proposed framework to optimize the tuned mass damper (TMD) design, useful for seismic improvement of slender masonry structures. A historical masonry chimney located in northern Italy was considered to illustrate the proposed TMD design procedure and to evaluate the seismic performance of the system. The optimization process was subdivided into two fundamental phases. In the first phase, the main TMD parameters were defined starting from the dynamic behavior of the chimney by finite element modeling (FEM). A series of linear time-history analyses were carried out to point out the structural improvements in terms of top displacement, base shear, and bending moment. In the second phase, masonry's nonlinear behavior was considered, and a fiber model of the chimney was implemented. Pushover analyses were performed to obtain the capacity curve of the structure and to evaluate the performance of the TMD. The results of the linear and nonlinear analysis reveal the effectiveness of the proposed TMD design procedure for slender masonry structures.

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An Investigation of the Stability Enhancement of a Centrifugal Compressor Stage Using a Porous Throat Diffuser

Journal of Turbomachinery ◽

10.1115/1.4038181 ◽

2017 ◽

Vol 140 (1) ◽

Cited By ~ 8

Author(s):

Lee Galloway ◽

Stephen Spence ◽

Sung In Kim ◽

Daniel Rusch ◽

Klemens Vogel ◽

...

Keyword(s):

Centrifugal Compressor ◽

Compressor Stage ◽

Vaned Diffuser ◽

Flow Rates ◽

Stall Inception ◽

Centrifugal Compressor Stage ◽

Operating Range ◽

Stable Operating ◽

The Stability ◽

Circumferential Pressure

The stable operating range of a centrifugal compressor stage of an engine turbocharger is limited at low mass flow rates by aerodynamic instabilities which can lead to the onset of rotating stall or surge. There have been many techniques employed to increase the stable operating range of centrifugal compressor stages. The literature demonstrates that there are various possibilities for adding special treatments to the nominal diffuser vane geometry, or including injection or bleed flows to modify the diffuser flow field in order to influence diffuser stability. One such treatment is the porous throat diffuser (PTD). Although the benefits of this technique have been proven in the existing literature, a comprehensive understanding of how this technique operates is not yet available. This paper uses experimental measurements from a high pressure ratio (PR) compressor stage to acquire a sound understanding of the flow features within the vaned diffuser which affect the stability of the overall compression system and investigate the stabilizing mechanism of the porous throat diffuser. The nonuniform circumferential pressure imposed by the asymmetric volute is experimentally and numerically examined to understand if this provides a preferential location for stall inception in the diffuser. The following hypothesis is confirmed: linking of the diffuser throats via the side cavity equalizes the diffuser throat pressure, thus creating a more homogeneous circumferential pressure distribution, which delays stall inception to lower flow rates. The results of the porous throat diffuser configuration are compared to a standard vaned diffuser compressor stage in terms of overall compressor performance parameters, circumferential pressure nonuniformity at various locations through the compressor stage and diffuser subcomponent analysis. The diffuser inlet region was found to be the element most influenced by the porous throat diffuser, and the stability limit is mainly governed by this element.

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Water confined in solutions of biological relevance

Pure and Applied Chemistry ◽

10.1515/pac-2019-1202 ◽

2020 ◽

Vol 92 (10) ◽

pp. 1563-1574

Author(s):

Marie-Claire Bellissent-Funel

Keyword(s):

Aqueous Solutions ◽

Bulk Water ◽

Biological Macromolecules ◽

Organic Solutes ◽

Confined Water ◽

The Past ◽

Structure And Dynamics ◽

Biological Relevance ◽

The Stability

AbstractIn many relevant situations, water is not in its bulk form but instead attached to some substrates or filling some cavities. We shall call water in the latter environment confined water as opposed to bulk water. It is known that the confined water is essential for the stability and the function of biological macromolecules. In this paper, we provide a review of the experimental and computational advances over the past decades concerning the understanding of the structure and dynamics of water confined in aqueous solutions of biological relevance. Examples involving water in solution of organic solutes (cryoprotectants such as dimethylsulfoxide (DMSO), sugars such as trehalose) are provided.

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Reimagining unfinished architectures: ruin perspectives between art and heritage

Cultural Geographies ◽

10.1177/1474474018815912 ◽

2018 ◽

Vol 26 (2) ◽

pp. 227-244

Author(s):

Pablo Arboleda

Keyword(s):

Financial Crisis ◽

Broad Spectrum ◽

Organised Crime ◽

Public Works ◽

Architectural Style ◽

2008 Financial Crisis ◽

Complex Issue ◽

The Past ◽

Single Solution ◽

The 2008 Financial Crisis

For the past five decades, hundreds of unfinished public works have been erected in Italy as the result of inconsistent planning and the presence of corruption and organised crime. A third of these constructions are located in Sicily alone, and so, in 2007, a group of artists labelled this phenomenon an architectural style: ‘ Incompiuto Siciliano’. Through this creative approach, the artists’ objective is to put incompletion back on the agenda by viewing it from a heritage perspective. This article reviews the different approaches that the artists have envisaged to handle unfinished public works; whether to finish them, demolish them, leave them as they are or opt for an ‘active’ arrested decay. The critical implications of these strategies are analysed in order to, ultimately, conclude that incompletion is such a vast and complex issue that it will surely have more than one single solution; but rather a combination of these four. This is important because it opens up a debate on the broad spectrum of possibilities to tackle incompletion – establishing this as one of the key contemporary urban themes not only in Italy but also in those countries affected by unfinished geographies after the 2008 financial crisis.

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Future Directions in Surface Electromyography

Biofeedback ◽

10.5298/1081-5937-38.2.78 ◽

2010 ◽

Vol 38 (2) ◽

pp. 78-82 ◽

Cited By ~ 2

Author(s):

John G. Arena

Keyword(s):

Surface Electromyography ◽

Ambulatory Monitoring ◽

Future Directions ◽

The Past ◽

Psychophysiological Assessment ◽

The Future ◽

The Stability

Abstract The use of surface electromyography (SEMG) has increased exponentially in the past four decades. SEMG is one of the most widespread measures employed today in psychophysiological assessment and one of three primary biofeedback modalities. This article briefly outlines three areas that the author believes are important for SEMG to address if it is to continue to flourish in the future: applications in telehealth, the use of telemetry and ambulatory monitoring, and studies on the stability or reliability of surface electromyography.

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