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

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

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.

Effects of marble, timber, and glass powder as partial replacements for cement

Waste materials, such as glass, marble, and timber, are pressing environmental problems worldwide, and their environmental impact can be best overcome by reusing them. This research mainly aims to determine the impact of using waste materials, such as crushed glass, crushed marble, and burned wood in powder form, as partial replacements for cement on the compressive strength of concrete. Mechanical properties (e.g., compressive strength) and physical properties (e.g., workability and unit weight) were investigated. The powdered waste materials (after passing through sieve #200) were partially replaced with cement by ratios of 10%, 20%, and 30%. Compressive strength was tested on the 7th, 28th, and 56th days. Results showed that workability decreased as the partial replacement level of glass powder, marble powder, and timber ash increased. The results also showed a decrease in the compressive strength of concrete when the replacement level was increased from 10% to 30% for each waste material.

Effects of Marble Waste on Properties of Polymer Concrete

The quantities of wastes, generated in industry are increasing every year. Their utilization became a priority for solving pollution problem and save energy and resources. The wastes are investigated as materials for obtaining new concretes with different applications. Polymer concrete is a composite material, in which the aggregates of different sorts are bound together by a resin. As in the case of cement concrete, different types of wastes (slag, glass, marble, etc.) can replace the aggregates or they can be added in the concrete composition as filler (silica powder, fly ash, calcareous powder, etc). The use of wastes presents some advantages such as: obtaining of new products at lower prices, in some cases with improved properties; consuming of wastes helps to clean the environment; preservation of natural resources which are replaced by wastes; etc.In the experimental study, marble waste is used for obtaining epoxy polymer concrete. The effects of this type of waste on the mechanical properties of polymer concrete were investigated. Two types of concrete were prepared: one with powder of marble as addition and the other type with aggregates of marble waste. The mechanical properties (compressive strength, flexural strength, split tensile strength) were experimentally determined and compared with the characteristics of epoxy polymer concrete (considered as reference mix). The microstructure of polymer concrete with marble waste was analyzed by SEM images. The marble waste influenced the mechanical properties of epoxy polymer concrete. Higher values of mechanical properties were obtained when the marble was used as aggregates. As addition in epoxy polymer concrete, the dosage and finesse of marble had influenced the values of mechanical properties.

Experimental Investigations on Rubber Friction Coefficient Dependence on Visco-Elastic Characteristics, Track Roughness, Contact Force, and Slide Velocity

ABSTRACT The results of an experimental activity, carried out using a prototype of pin on disk machine and aimed at investigating the frictional behavior of visco-elastic materials in sliding contact with rigid asperities, are presented. The pin is a rubber specimen coming from three different passenger automotive tires, while the disk is covered with glass, marble, or 3M anti-slip tape surfaces. Tests, performed both in dry and wet conditions, highlighted that the friction coefficient is strongly influenced by the effect that surface roughness plays on friction mechanisms of adhesion and hysteresis. The results confirmed the theoretical dependence of friction on vertical load, sliding velocity, rubber characteristics, and track conditions.

Transorbital Removal of Foreign Body in the Sphenoid Sinus

Objective: To report a case of foreign body lodged within the sphenoid sinus and its extraction. Methods: Design: Case Report Setting: Tertiary Government Hospital Patient: One Results: An 11-year-old girl was hit in the eye by an unknown object from an improvised slingshot. She had loss of vision of the left eye and headache, without loss of consciousness. A plain craniofacial Computed Tomography (CT) scan showed a round opaque foreign body abutting the left sphenoid sinus, left posterior ethmoid cells and medial aspect of the left orbital region with adjacent soft tissue densities extending into the apparently ruptured, irregular left globe. The left posterior part of the lamina papyracea was not visualized, probably fractured or ruptured. Transorbital enucleation of the left eye and endoscopic-guided removal of the foreign body (a glass marble) were performed with no intra – operative and post – operative complications. Conclusion: Foreign body of the sphenoid sinus is a rare condition. Adequate imaging is important for localization and planning the optimal surgical approach. Endoscopic guidance may aid in extraction. Keywords: Sphenoid sinus foreign body, Computed Tomography (CT), Endoscopic-guided, transorbital approach

Tyre-Road Interaction: Experimental Investigations About the Friction Coefficient Dependence on Contact Pressure, Road Roughness, Slide Velocity and Temperature

In this paper the results of an experimental activity carried out with the aim to investigate on the frictional behaviour of visco-elastic materials in sliding contact with road asperities is presented. Experiments are carried out using a prototype of pin on disk machine whose pin is constituted by a specimen of rubber coming from a commercial tyre while the disk may be in glass, marble or abrasive paper. Tests are performed both in dry and wet conditions. Roughness of the disk materials is evaluated by a tester and by a laser scan device. Temperature in proximity of the contact patch is measured by pyrometer pointed on the disk surface in the pin trailing edge, while room temperature is measured by a thermocouple. Sliding velocity is imposed by an inverter controlled motor driving the disk and measured by an incremental encoder. Vertical load is imposed applying calibrated weights on the pin and friction coefficients are measured acquiring the longitudinal forces signal by means of a load cell. As regards to the road roughness, the experimental results show a marked dependence with road Ra index. Dry and wet tests performed on different micro-roughness profiles (i.e. glass and marble) highlighted that friction coefficient in dry conditions is greater on smoother surfaces, while an opposite tendency is shown in wet conditions. Although affected by uncertainties the results confirm the dependence of friction on temperature, vertical load and track conditions.