scholarly journals How Do We Determine the Efficacy of an Antibacterial Surface? A Review of Standardised Antibacterial Material Testing Methods

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1069
Author(s):  
Alexander J. Cunliffe ◽  
Peter D. Askew ◽  
Ina Stephan ◽  
Gillian Iredale ◽  
Patrick Cosemans ◽  
...  

Materials that confer antimicrobial activity, be that by innate property, leaching of biocides or design features (e.g., non-adhesive materials) continue to gain popularity to combat the increasing and varied threats from microorganisms, e.g., replacing inert surfaces in hospitals with copper. To understand how efficacious these materials are at controlling microorganisms, data is usually collected via a standardised test method. However, standardised test methods vary, and often the characteristics and methodological choices can make it difficult to infer that any perceived antimicrobial activity demonstrated in the laboratory can be confidently assumed to an end-use setting. This review provides a critical analysis of standardised methodology used in academia and industry, and demonstrates how many key methodological choices (e.g., temperature, humidity/moisture, airflow, surface topography) may impact efficacy assessment, highlighting the need to carefully consider intended antimicrobial end-use of any product.

2003 ◽  
Vol 11 (3) ◽  
pp. 219-227 ◽  
Author(s):  
Chris Kneale

Many factors need to be considered in the design of new biocides for use in plastics applications. In Europe, biocides are now becoming more tightly regulated under the Biocidal Products Directive (BPD), and a significant data package needs to be provided not only for the registration of new actives, but also for existing biocides and biocidal formulations. A novel biocide must be compatible with the polymer matrix and must not adversely affect its physical properties. Once the issue of compatibility has been overcome, the antimicrobial efficacy of the biocide in the substrate should be established. Before selecting a test method to demonstrate such efficacy, it is necessary to consider whether the substrate should be pre-conditioned to simulate end use conditions, e.g. by leaching or artificial weathering. The final use of the product can also dictate the test protocol, e.g. a building membrane for ground contact should be evaluated using a soil burial test. Historically, biocides have been added to plastics to prevent their spoilage by fungal attack. Latterly, plastics with antibacterial effects have aroused much public interest. Advantages and disadvantages of traditional test methods will be discussed, and an alternative method for the evaluation of biocidal performance that is thought to be more representative of end use conditions will be presented.


TAPPI Journal ◽  
2009 ◽  
Vol 8 (6) ◽  
pp. 24-28
Author(s):  
CORY JAY WILSON ◽  
BENJAMIN FRANK

TAPPI test T811 is the specified method to ascertain ECT relative to box manufacturer’s certification compliance of corrugated fiberboard under Rule 41/ Alternate Item 222. T811 test sample heights were derived from typical board constructions at the time of the test method’s initial development. New, smaller flute sizes have since been developed, and the use of lighter weight boards has become more common. The T811 test method includes sample specifications for typical A-flute, B-flute, and C-flute singlewall (and doublewall and triplewall) structures, but not for newer thinner E-flute or F-flute structures. This research explores the relationship of ECT sample height to measured compressive load, in an effort to determine valid E-flute and F-flute ECT sample heights for use with the T811 method. Through this process, it identifies challenges present in our use of current ECT test methods as a measure of intrinsic compressive strength for smaller flute structures. The data does not support the use of TAPPI T 811 for ECT measurement for E and F flute structures, and demonstrates inconsistencies with current height specifi-cations for some lightweight B flute.


Machines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 4 ◽  
Author(s):  
Luqman S. Maraaba ◽  
Zakariya M. Al-Hamouz ◽  
Abdulaziz S. Milhem ◽  
Ssennoga Twaha

The application of line-start permanent magnet synchronous motors (LSPMSMs) is rapidly spreading due to their advantages of high efficiency, high operational power factor, being self-starting, rendering them as highly needed in many applications in recent years. Although there have been standard methods for the identification of parameters of synchronous and induction machines, most of them do not apply to LSPMSMs. This paper presents a study and analysis of different parameter identification methods for interior mount LSPMSM. Experimental tests have been performed in the laboratory on a 1-hp interior mount LSPMSM. The measurements have been validated by investigating the performance of the machine under different operating conditions using a developed qd0 mathematical model and an experimental setup. The dynamic and steady-state performance analyses have been performed using the determined parameters. It is found that the experimental results are close to the mathematical model results, confirming the accuracy of the studied test methods. Therefore, the output of this study will help in selecting the proper test method for LSPMSM.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2315
Author(s):  
Christian Meltebrink ◽  
Tom Ströer ◽  
Benjamin Wegmann ◽  
Cornelia Weltzien ◽  
Arno Ruckelshausen

As an essential part for the development of autonomous agricultural robotics, the functional safety of autonomous agricultural machines is largely based on the functionality and robustness of non-contact sensor systems for human protection. This article presents a new step in the development of autonomous agricultural machine with a concept and the realization of a novel test method using a dynamic test stand on an agricultural farm in outdoor areas. With this test method, commercially available sensor systems are tested in a long-term test around the clock for 365 days a year and 24 h a day on a dynamic test stand in continuous outdoor use. A test over a longer period of time is needed to test as much as possible all occurring environmental conditions. This test is determined by the naturally occurring environmental conditions. This fact corresponds to the reality of unpredictable/determinable environmental conditions in the field and makes the test method and test stand so unique. The focus of the developed test methods is on creating own real environment detection areas (REDAs) for each sensor system, which can be used to compare and evaluate the autonomous human detection of the sensor systems for the functional safety of autonomous agricultural robots with a humanoid test target. Sensor manufacturers from industry and the automotive sector provide their sensor systems to have their sensors tested in cooperation with the TÜV.


2014 ◽  
Vol 687-691 ◽  
pp. 3110-3115
Author(s):  
Gu Li ◽  
Zi Ming Fu ◽  
Jie Feng Yan ◽  
Bing Wen Li ◽  
Zhi Rong Cen

This paper analyzes and studies the definition of the voltage transformer secondary load, examines the practical purposes of the measured values of the voltage transformer secondary load, and presents a variety of testing methods to analyze and compare the differences. This paper gives the test methods of the voltage transformer secondary load when the connection of the voltage transformer is the Y / Y in a three-phase three-wire power supply system, filling the blank of this type of test method in the industry. When other units within the industry carry out such work, the conclusions of this paper are available for reference, and the conclusions of this paper can be referred when drafting relevant regulations in the future.


2017 ◽  
Vol 726 ◽  
pp. 414-418
Author(s):  
Bo Fu ◽  
Hui Wang ◽  
Zhu Feng Shao

The optical quartz glass is widely applied in optical system , photo communications,inertial navigation,etc.It must have high optical homogeneity. Optical homogeneity of the optical quartz glass directly affects the wavefront quality of the optical transmission system, and changes the wavefront aberration of the system. How to accurately determine the optical homogeneity of the quartz glass is especially important. Currently,the method of test for optical homogeneity mainly used by interference principle. This paper analyzes various existing interference measurement method and test equipment. Summarized the advantages and disadvantages of various test methods,using range and measurement accuracy.


Author(s):  
Chienann A. Hou ◽  
Shijun Ma

Abstract The allowable bending stress Se of a gear tooth is one of the basic factors in gear design. It can be determined by either the pulsating test or the gear-running test. However, some differences exist between the allowable bending stress Se obtained from these different test methods. In this paper, the probability distribution functions corresponding to each test method are analyzed and the expressions for the minimum extreme value distribution are presented. By using numerical integration, Se values from the population of the same tested gear tooth are obtained. Based on this investigation it is shown that the differences in Se obtained from the different test methods are significant. A proposed correction factor associated with the different experimental approaches is also presented.


Author(s):  
N.I. Konstantinova ◽  
◽  
N.V. Smirnov ◽  
O.V. Krivoshapkina ◽  
O.I. Molchadskiy ◽  
...  

Fiber cement finishing materials are widely used in the construction of industrial buildings and structures due to the complex of valuable operational properties. In the Russian market there are fiber-cement panels with a variety of design solutions for their coloring and application of protective coatings. Fiber cement board is a strong and moisture-resistant composite material made from a cement-sand mixture, reinforcing cellulose fibers and special additives. Not being a non-combustible material, the fiber cement boards in accordance with the current mandatory requirements, as a decorative, finishing and facing material for walls and ceilings have restrictions on their use. Existing domestic requirements regarding the methodology for assessing the combustibility of fiber cement products largely narrow the field of using these materials. Therefore, it is advisable to develop the proposals for amending the test methods and the regulatory framework governing their fire-safe extended scope. In the course of this work execution, the main provisions of the regulatory and methodological framework that establish the requirements for the fire-safe use of fiber cement materials are analyzed. Experimental complex studies of fire hazard properties of various types of samples of the fiber cement finishing panels and slabs were carried out. It is established that fiber-cement materials belong to the class of the least fire-hazardous materials. Advisability is determined concerning the introduction to the national regulatory practice of GOST R «Building materials. Test method for fire hazard under thermal exposure with a single burner (SBI)». Classification parameters of the group of non-combustible materials NG2 were established to amend GOST R 57270—2016 (method 1). Classification parameters of the group of non-combustible materials NG2 for making changes in GOST R 57270—2016 (method 1) are established. Proposals were developed to expand the scope of application of the materials and products made of fiber cement as enclosing structures, partitions, and decorative finishes (cladding) in the buildings and structures.


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