Natural Attenuation as a Decontamination Approach for SARS-CoV-2 on Library Materials

2021 ◽  
Vol 70 (1) ◽  
pp. 65-74
Author(s):  
Maria V. Fedotova
Keyword(s):  
Relative Humidity ◽  
Natural Attenuation ◽  
Room Temperature ◽  
Building Materials ◽  
Library Services ◽  
Coated Steel ◽  
Active Virus ◽  
Glass Marble ◽  
Computer Library ◽  
The Common

Based on the current scientific understanding regarding COVID-19, this article presents the results of new studies (Tests 4, 5, 6), conducted by the Institute of Museum and Library Services (IMLS) and the Online Computer Library Center (OCLC), in partnership with Battelle. The purpose of the experiments is to determine how long frequently circulated library, museum and archival materials should be quarantined before being put back into public circulation.Each test has been conducted by applying the virulent SARS-CoV-2 virus on various materials held at standard room temperature and relative humidity conditions, and then examining the rate of natural attenuation of the virus. The items were not sterilized before testing. Battelle propagated the clinical isolate of the SARS-CoV-2 virus in-house, followed by characterization and testing to establish a certified titer. The materials in Test 4 included binding and cover items placed in a stacked configuration to imitate the common practice that libraries employ when handling book/DVD returns, as well as expanded polyethylene foam, which is typically used in museums for storage and shipping. Test 5 focused on textiles, while Test 6 included building materials (glass, marble, brass, laminate, and powder-coated steel). Test coupons cut from the materials were inoculated with active virus, and then allowed to dry. The test coupons were then examined at the following timepoints: on the second, third, fourth and sixth day (Test 4); on the second, fourth, sixth and eighth day (Tests 5 and 6). The results of the tests showed how much virus was detectable at the selected timepoints. In Test 4, the virus was still detected on all the five materials after six days. In Test 5, the virus was still detected on leather and synthetic leather publication after eight days. In Test 6, the virus was not detected on the tested materials after six days.This publication is provided for informational purposes only, and readers are encouraged to review federal, regional, and local guidance. The authors, sponsors and researchers are not liable for any damages resulting from use, misuse, or reliance upon this information, or any errors or omissions herein.

Natural Attenuation as a Decontamination Approach for SARS-CoV-2 on Library Materials

2021 ◽  
Vol 70 (1) ◽  
pp. 65-74
Author(s):  
Maria V. Fedotova
Keyword(s):  
Relative Humidity ◽  
Natural Attenuation ◽  
Room Temperature ◽  
Building Materials ◽  
Library Services ◽  
Coated Steel ◽  
Active Virus ◽  
Glass Marble ◽  
Computer Library ◽  
The Common

Based on the current scientific understanding regarding COVID-19, this article presents the results of new studies (Tests 4, 5, 6), conducted by the Institute of Museum and Library Services (IMLS) and the Online Computer Library Center (OCLC), in partnership with Battelle. The purpose of the experiments is to determine how long frequently circulated library, museum and archival materials should be quarantined before being put back into public circulation.Each test has been conducted by applying the virulent SARS-CoV-2 virus on various materials held at standard room temperature and relative humidity conditions, and then examining the rate of natural attenuation of the virus. The items were not sterilized before testing. Battelle propagated the clinical isolate of the SARS-CoV-2 virus in-house, followed by characterization and testing to establish a certified titer. The materials in Test 4 included binding and cover items placed in a stacked configuration to imitate the common practice that libraries employ when handling book/DVD returns, as well as expanded polyethylene foam, which is typically used in museums for storage and shipping. Test 5 focused on textiles, while Test 6 included building materials (glass, marble, brass, laminate, and powder-coated steel). Test coupons cut from the materials were inoculated with active virus, and then allowed to dry. The test coupons were then examined at the following timepoints: on the second, third, fourth and sixth day (Test 4); on the second, fourth, sixth and eighth day (Tests 5 and 6). The results of the tests showed how much virus was detectable at the selected timepoints. In Test 4, the virus was still detected on all the five materials after six days. In Test 5, the virus was still detected on leather and synthetic leather publication after eight days. In Test 6, the virus was not detected on the tested materials after six days.This publication is provided for informational purposes only, and readers are encouraged to review federal, regional, and local guidance. The authors, sponsors and researchers are not liable for any damages resulting from use, misuse, or reliance upon this information, or any errors or omissions herein.

scholarly journals Back protection of canvas paintings

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Tim Padfield ◽  
Nicolas Padfield ◽  
Daniel Sang-Hoon Lee ◽  
Anne Thøgersen ◽  
Astrid Valbjørn Nielsen ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Relative Humidity ◽  
Temperature Variation ◽  
Room Temperature ◽  
Single Point ◽  
Confined Space ◽  
Constant Wall Temperature ◽  
Back Plate ◽  
Inner Surface

Abstract In this paper different scenarios for back protection of a canvas painting and their effect on the stability of the relative humidity behind the painting are tested. A painting on canvas, stretched on a wooden frame, was fitted with various styles of back protection and then exposed to a cycle of temperature variation at the back, with the front exposed to a constant room temperature. The painting was also exposed to a constant wall temperature and varying room temperature. The space between the canvas and the back board was fitted with temperature and relative humidity (RH) sensors. The sensors were used to provide the essential single-point data of temperature and RH at the given locations. For more comprehensive understanding of the rather confined space, further numerical simulation (computational fluid dynamics) was adopted as part of the investigation. The computational fluid dynamics was used to understand the natural convection within the microclimate through the depictions of temperature distribution, as well as the corresponding airflow. The unprotected painting suffered a large RH variation at its back, because of the varying canvas temperature interacting with the constant room air moisture content. Effective stabilisation of the RH behind the canvas against temperature variation was provided by a shiny aluminium alloy sheet sealed against the frame. The non-absorbent back board experienced a strong variation in RH, because of humidity buffering of the space by the painting canvas at a different temperature. Either a space or insulation between this back plate and the wall reduced the risk of condensation on the inner surface of the back plate. Insulation will however increase the risk of condensation on the wall surface behind the painting. An absorbent back board de-stabilised the RH at the painting canvas surface by providing a competing humidity buffer at a different temperature. To provide protection against moisture exchange with an unsuitable room RH, extra humidity buffer was placed 3 mm behind the painting canvas, kept close to the painting temperature by insulation between this buffer and the back board. This stabilised RH at the canvas surface but increased both the temperature and the RH variation at the back board and thus increased the risk of condensation on the inner surface of the back board. The RH and the temperature in the narrow spaces between the painting canvas and the wooden stretcher frame were always more nearly constant than in the open canvas area, which suggests an explanation for the widely observed better condition of the areas of canvas paintings which lie close over the support structure. Our conclusion is that a non-absorbent, impermeable back plate gives good RH stability against a changing temperature gradient between wall and canvas painting surface.

Molecule-Based Magnets—An Overview

MRS Bulletin ◽  
2000 ◽  
Vol 25 (11) ◽  
pp. 21-30 ◽  
Author(s):  
Joel S. Miller ◽  
Arthur J. Epstein
Keyword(s):  
Low Temperature ◽  
Vapor Deposition ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Magnetic Ordering ◽  
Low Density ◽  
Materials Properties ◽  
The Common ◽  
New Processing ◽  
Very High

Molecule-based magnets are a broad, emerging class of magnetic materials that expand the materials properties typically associated with magnets to include low density, transparency, electrical insulation, and low-temperature fabrication, as well as combine magnetic ordering with other properties such as photoresponsiveness. Essentially all of the common magnetic phenomena associated with conventional transition-metal and rare-earth-based magnets can be found in molecule-based magnets. Although discovered less than two decades ago, magnets with ordering temperatures exceeding room temperature, very high (∼27.0 kOe or 2.16 MA/m) and very low (several Oe or less) coercivities, and substantial remanent and saturation magnetizations have been achieved. In addition, exotic phenomena including photoresponsiveness have been reported. The advent of molecule-based magnets offers new processing opportunities. For example, thin-film magnets can be prepared by means of low-temperature chemical vapor deposition and electrodeposition methods.

CLAY-INORGANIC STUDIES. II. HYDROXY ALUMINUM PHOSPHATE–MONTMORILLONITE COMPLEX

1975 ◽  
Vol 55 (2) ◽  
pp. 225-233 ◽  
Author(s):  
H. KODAMA ◽  
M. D. WEBBER
Keyword(s):  
Relative Humidity ◽  
Room Temperature ◽  
Aluminum Phosphate ◽  
Silicate Layer ◽  
Basal Spacing ◽  
Minor Amount ◽  
Chemical Compositions ◽  
A Minor ◽  
Positively Charged ◽  
Water Contents

Two specimens of hydroxy aluminum phosphate interlayer materials in montmorillonite clay were prepared with 7.20 meq Al and 11.29 meq H3PO4/g clay and with 14.40 meq Al and 22.58 meq H3PO4/g clay, and the resulting complexes studied by chemical and mineralogical methods. Both interlayer materials were slightly positively charged and except for different water contents their chemical compositions were almost identical. They contained Al, PO4 and H2O and a minor amount of Ca and approximated hydrous AlPO4∙nH2O. The mole ratios of Al:Ca:PO4:OH were 1.00:0.08:0.92:0.24 and 1.00:0.05:0.91:0.24, respectively. The interlayer materials appeared to be loosely packed and distributed sparsely in interspaces of the montmorillonite. The degree of packing was greater for the preparation with the larger amount of interlayer material. The materials increased the montmorillonite basal spacing to 23.3 Å under air-dry condition (30–40% relative humidity) but did not affect the lateral dimensions. The basal spacing varied somewhat with relative humidity at room temperature and decreased markedly as water was driven off by heating. Heat treatments between room temperature and 300 C sharply reduced the d001 spacings to 16.7 Å which persisted up to 700 C. It is postulated that the large basal spacings occur because the hydrated interlayer materials have a framework structure with tunnels along the c-axis. This being so, changes in the spacings with different humidities might result from the movement of water molecules among interstitial spaces existing around and between the loosely distributed molecules of interlayer material. The 16.7 Å spacing for the dehydrated phase corresponds to the sum of 7.0 Å, the edge dimension of an orthorhombic anhydrous AlPO4 and 9.7 Å, the silicate layer thickness.

Preparation and Characterization of Modified PVDF-g-PSSA Membrane

2010 ◽  
Vol 152-153 ◽  
pp. 44-50 ◽  
Author(s):  
Gui Bao Guo ◽  
Er Ding Han ◽  
Sheng Li An
Keyword(s):  
Relative Humidity ◽  
Sodium Silicate ◽  
Room Temperature ◽  
Proton Exchange Membrane ◽  
Vinylidene Fluoride ◽  
Proton Exchange ◽  
Poly Vinylidene Fluoride ◽  
Relative Humidity Range ◽  
Exchange Membrane

A new method based on a solution graft technique was used to prepare poly (vinylidene fluoride) grafted polystyrene sulfonated acid (PVDF-g-PSSA) proton exchange membrane. Polystyrene is grafted into PVDF modified by plain sodium silicate (Na4SiO4). There is a linear relationship between the degree of grafting and the content of Na4SiO4. Fourier transform infrared spectroscopy is used to characterize changes of the membrane's microstructures after grafting and sulfonation. The morphology of the membrane's microstructures after grafting and sulfonation is studied by scanning electrolytic microscope (SEM). The effect of plain sodium silicate (Na4SiO4) concentration and relative humidity on the conductivity of the electrolyte was investigated by the impedance at room temperature. The results show that the styrene has been grafted into PVDF. The conductivity of PVDF-g-PSSA electrolyte doped 10% plain sodium silicate (Na4SiO4) is 0.016 S/cm at room temperature. The conductivity of the electrolyte changes slightly at a relative humidity range of 20%-70%. The weightlessness of PVDF-g-PSSA electrolyte heated to 40°C was less than 2%, which indicated that water capacity was good.

scholarly journals FLUAZIFOP-P-BUTYL EFFICACY AS A FUNCTION OF APPLICATION TIME AND HERBICIDE DOSE

2017 ◽  
Vol 35 (0) ◽  
Author(s):  
L.F. CIESLIK ◽  
R.A. VIDAL ◽  
A.B. MACHADO ◽  
M.M. TREZZI
Keyword(s):  
Relative Humidity ◽  
Common Bean ◽  
Weed Control ◽  
Air Temperature ◽  
Field Experiments ◽  
Time Of Day ◽  
Leaf Angle ◽  
Herbicide Application ◽  
The Common ◽  
Bean Crop

ABSTRACT Grass weeds are common in summer crops and strongly decreases the grain yield of the common bean crop. The time of herbicide application influences the variability of environmental conditions and affects the product performance. The objectives of this work were to identify the time of fluazifop-p-butyl (fluazifop) application which gives best grass weed control in the common bean crop and to elucidate the environmental variables most important for the efficacy of this herbicide. Field experiments were conducted involving five application times (2 a.m., 6 a.m., 11 a.m., 4 p.m. and 9 p.m.) and five doses of fluazifop (80, 110, 140, 170 and 200 g ha-1), with additional no-herbicide control. At the time of the herbicide application it was determined the air temperature, relative humidity, the photosynthetically active radiation (PAR) and the leaf angle, whereas the weed control and the dry mass of the weed Urochloa plantaginea was assessed at 20 days after treatment (DAT). Efficacy on grass control with fluazifop was dependent on the herbicide dose and on the time of day that the product was applied. Spray at early morning hours (6 a.m.) showed better efficacy on weed control in relation to periods during warmer conditions of the day (11 a.m. and 4 p.m.). Nocturnal fluazifop application had better weed control when compared to herbicide sprayed in the afternoon. The air temperature, relative humidity and PAR were correlated to weed leaf angle, which correlated the most with fluazifop performance.

Stability of extemporaneously prepared rosuvastatin oral suspension

2017 ◽  
Vol 74 (19) ◽  
pp. 1579-1583 ◽  
Author(s):  
Abdel Naser Zaid ◽  
Rania Shtayah ◽  
Ayman Qadumi ◽  
Mashour Ghanem ◽  
Rawan Qedan ◽  
...  
Keyword(s):  
Relative Humidity ◽  
High Performance ◽  
Room Temperature ◽  
Microbial Contamination ◽  
Active Pharmaceutical Ingredient ◽  
Storage Conditions ◽  
Dissolution Profile ◽  
Stability Studies ◽  
Organoleptic Properties ◽  
The Stability

Abstract Purpose The stability of an extemporaneously prepared rosuvastatin suspension stored over 30 days under various storage conditions was evaluated. Methods Rosuvastatin suspension was extemporaneously prepared using commercial rosuvastatin tablets as the source of active pharmaceutical ingredient. The organoleptic properties, dissolution profile, and stability of the formulation were investigated. For the stability studies, samples of the suspension were stored under 2 storage conditions, room temperature (25 °C and 60% relative humidity) and accelerated stability chambers (40 °C and 75% relative humidity). Viscosity, pH, organoleptic properties, and microbial contamination were evaluated according to the approved specifications. High-performance liquid chromatography was used for the analysis and quantification of rosuvastatin in selected samples. Microbiological investigations were also conducted. Results The prepared suspension showed acceptable organoleptic properties. It showed complete release of rosuvastatin within 15 minutes. The pH of the suspension was 9.8, which remained unchanged during the stability studies. The microbiological investigations demonstrated that the preparation was free of any microbial contamination. In addition, the suspension showed stability within at least the period of use of a 100-mL rosuvastatin bottle. Conclusion Extemporaneously prepared rosuvastatin 20-mg/mL suspension was stable for 30 days when stored at room temperature.

scholarly journals Limiting the Oxidation of WS2 Nanostructures by Oleylamine Surface Passivation for Room Temperature NH3 Sensing

2020 ◽  
Author(s):  
Siziwe Gqoba ◽  
Rafael Rodrigues ◽  
Sharon Lerato Mphahlele ◽  
Zakhele Ndala ◽  
Mildred Airo ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Room Temperature ◽  
Surface Passivation ◽  
Electrical Response ◽  
Prolonged Incubation ◽  
P Type ◽  
2D Nanosheets ◽  
Type Response ◽  
And Diffusion ◽  
Hierarchical Morphology

Oleylamine capped WS2 nanostructures were successfully formed at 320 °C via a relatively simple colloidal route. SEM and TEM analyses showed that the 3D nanoflowers that were initially formed disintegrated into 2D nanosheets after prolonged incubation. XPS and XRD analyses confirmed oxidation of WS2 into WO3. Sensors based on these oleylamine capped WS2 nanoflowers and nanosheets still showed a change in electrical response towards various concentrations of NH3 vapour at room temperature in a 25% relative humidity background despite the oxidation. The nanoflowers exhibited n-type response while the nanosheets displayed a p-type response towards NH3 exposure. The nanoflower based sensors showed better response to NH3 vapour exposure than the nanosheets. The sensors showed a good selectivity towards NH3 relative to acetone, ethanol, chloroform and toluene. Meanwhile, a strong interference of humidity to the NH3 response was displayed at high relative humidity levels. The results demonstrated that oleylamine limited the extent of oxidation of WS2 nanostructures. The superior sensing performance of the nanoflowers can be attributed to their hierarchical morphology which enhances the surface area and diffusion of the analyte.

A discussion on building technology in the 1980s - The contribution of the materials scientist

1972 ◽  
Vol 272 (1229) ◽  
pp. 585-593 ◽  
Keyword(s):  
Building Materials ◽  
Materials Science ◽  
Surface Coatings ◽  
Glass Technology ◽  
Teaching And Research ◽  
Building Technology ◽  
Recent Innovation ◽  
Conservative Attitude ◽  
The Common ◽  
Cement And Concrete

Some examples are given of recent innovation in building materials which show that the common impression that there is little innovation is false. There has been, however, a conservative attitude, and design has to some extent been hampered by the need to choose materials from the existing catalogue. The pace of innovation is likely to be accelerated in the future by two trends: specification by performance and the emergence of teaching and research in materials science. Current research and applications in the fields of cement and concrete, glass technology, metals, plastics and surface coatings are mentioned by way of illustration and an estimate of future progress is made.

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