scholarly journals Textile testing to assess the resistance to damage of long-lasting insecticidal nets for malaria control and prevention

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Amy Wheldrake ◽  
Estelle Guillemois ◽  
Hamidreza Arouni ◽  
Vera Chetty ◽  
Stephen J. Russell
Keyword(s):  
Textile Industry ◽  
Mechanical Damage ◽  
Performance Standards ◽  
Test Methods ◽  
Testing Methods ◽  
Bursting Strength ◽  
Good Physical Condition ◽  
Control And Prevention ◽  
Textile Testing ◽  
Knitted Structure

Abstract Background LLINs are susceptible to forming holes within a short time in use, compromising their ability to provide long-term physical protection against insect-borne vectors of disease. Mechanical damage is known to be responsible for the majority of holes, with most being the result of snagging, tearing, hole enlargement, abrasion and seam failure, which can readily occur during normal household use. To enable an assessment of the ability of LLINs to resist such damage prior to distribution, a new suite of testing methods was developed to reflect the main damage mechanisms encountered during normal use of LLINs. Methods Four existing BS EN and ISO standards used by the textile industry were adapted to determine the ability of LLINs to resist the most common mechanisms of real-world damage experienced in the field. The new suite comprised tests for snag strength (BS 15,598:2008), bursting strength (ISO 13938-2:1999), hole enlargement resistance (BS 3423–38:1998), abrasion resistance (ISO 12947-1:1998) and new guidance around the seam construction of LLINs. Fourteen different LLINs were tested using the new suite of tests to evaluate their resistance to damage. Results The resistance to mechanical damage of LLINs is not the same, even when the bursting strength values are comparable. Differences in performance between LLINs are directly related to the fabric design specifications, including the knitted structure and constituent yarns. The differences in performance do not primarily relate to what polymer type the LLIN is made from. LLINs made with a Marquisette knitted structure produced the highest snag strength and lowest hole enlargement values. By contrast, LLINs made with a traverse knitted structure exhibited low snag strength values when compared at the same mesh count. Conclusions Prequalification of LLINs should consider not only insecticidal performance, but also inherent resistance to mechanical damage. This is critical to ensuring LLINs are fit for purpose prior to distribution, and are capable of remaining in good physical condition for longer. The new suite of test methods enables the performance of LLINs to be assessed and specified in advance of distribution and can be used to establish minimum performance standards. Implementation of these testing methods is therefore recommended.

scholarly journals Development of a single resistance to damage metric for mosquito nets related to physical integrity in the field

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Amy Wheldrake ◽  
Estelle Guillemois ◽  
Vera Chetty ◽  
Albert Kilian ◽  
Stephen J. Russell
Keyword(s):  
Mechanical Damage ◽  
End User ◽  
Physical Integrity ◽  
Good Physical Condition ◽  
Mosquito Nets ◽  
Performance Metric ◽  
Physical Deterioration ◽  
Testing Data ◽  
Key Factor ◽  
Textile Testing

Abstract Background In common with the majority of personal protective equipment and healthcare products, the ability for long-lasting insecticidal nets (LLINs) to remain in good physical condition during use is a key factor governing fitness for purpose and serviceability. The inherent ability of a product to resist physical deterioration should be known in advance of it being used to ensure it has maximum value to both the end-user and procurer. The objective of this study was to develop a single performance metric of resistance to damage (RD) that can be applied to any LLIN product prior to distribution. Methods Algorithms to calculate RD values were developed based on consideration of both human factors and laboratory testing data. Quantitative reference forces applied to LLINs by users during normal use were determined so that aspirational performance levels could be established. The ability of LLINs to resist mechanical damage was assessed based on a new suite of textile tests, reflecting actual mechanisms of physical deterioration during normal household use. These tests quantified the snag strength, bursting strength, abrasion resistance and resistance to hole enlargement. Sixteen different unused LLINs were included in the analysis. The calculated RD values for all LLINs and the corresponding physical integrity data for the same nets retrieved from the field (up to 3 years of use) were then compared. Results On a RD scale of 0 (lowest resistance) – 100 (highest resistance), only six of the sixteen LLINs achieved an RD value above 50. No current LLIN achieved the aspirational level of resistance to damage (RD = 100), suggesting that product innovation is urgently required to increase the RD of LLINs. LLINs with higher RD values were associated with lower hole damage (PHI) in the field when adjusted for normal use conditions. Conclusions The RD value of any LLIN product can be determined prior to distribution based on the developed algorithms and laboratory textile testing data. Generally, LLINs need to achieve higher RD values to improve their ability to resist hole formation during normal use. Innovation in LLIN product design focused on the textile material should be actively encouraged and is urgently needed to close the performance gap.

scholarly journals Development of a Passive and Active Technology Package Standard and Database for Application to Zero Energy Buildings in South Korea

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1700 ◽  
Author(s):  
Uk-Joo Sung ◽  
Seok-Hyun Kim
Keyword(s):  
Building Materials ◽  
Performance Testing ◽  
Performance Standards ◽  
Test Methods ◽  
Building Energy Efficiency ◽  
Zero Energy ◽  
Testing Methods ◽  
Minimum Requirement ◽  
Zero Energy Building ◽  
Zero Energy Buildings

There is much research on zero energy buildings. In this paper, technologies and policies to improve the building energy efficiency of zero energy buildings are presented. The zero energy building certification system in Korea is introduced, and the evaluation is carried out based on the energy self-reliance rate that enables zero energy buildings. Zero energy buildings are able to minimize energy consumption due to the application of highly efficient building materials and equipment technology. In this research, to increase the prevalence of zero energy buildings in Korea, the authors propose a zero energy building technology package. Using a passive and active technology package, we confirmed the necessity and detailed requirements of each technology parameter. We analyze and classify Korean building material testing methods and performance standards, and propose passive and active technology packages, modules, material performance testing methods and minimum requirement performance standards. Finally, this study proposed a table presenting the test methods, standard and minimum value of performance. By these results, the authors confirmed the effectiveness and availability of passive and active technical packages.

TEST METHODS FOR POLYORGANOSILOXANE COMPOSITIONS USED AS PROTECTIVE COATINGS IN ELECTRONIC INSTRUMENTATION

2020 ◽  
Author(s):  
Ольга Владимировна Неёлова ◽  
Людмила Муратовна Кубалова ◽  
Анна Петровна Деревщикова
Keyword(s):  
Protective Coatings ◽  
Test Methods ◽  
Testing Methods ◽  
Organosilicon Polymer ◽  
Electronic Instrumentation

Представлен обзор по методам испытаний кремний органических полимерных композиций, применяемых в качестве защитных покрытий в современном электронном приборостроении. A review is given of testing methods for organosilicon polymer compositions used as protective coatings in modern electronic instrumentation.

Research the Test Method of the Voltage Transformer Secondary Load in the Three-Phase Three-Wire Electric Energy Metering Device

2014 ◽  
Vol 687-691 ◽  
pp. 3110-3115
Author(s):  
Gu Li ◽  
Zi Ming Fu ◽  
Jie Feng Yan ◽  
Bing Wen Li ◽  
Zhi Rong Cen
Keyword(s):  
Power Supply System ◽  
Electric Energy ◽  
Test Methods ◽  
Test Method ◽  
Testing Methods ◽  
Voltage Transformer ◽  
Secondary Load ◽  
Three Phase ◽  
Energy Metering ◽  
Definition Of

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.

scholarly journals Use of Molecular and Reference Susceptibility Testing Methods in a Multicenter Evaluation of MicroScan Dried Overnight Gram-Positive MIC Panels for Detection of Vancomycin and High-Level Aminoglycoside Resistances in Enterococci

1998 ◽  
Vol 36 (10) ◽  
pp. 2996-3001 ◽  
Author(s):  
Yao-Shen Chen ◽  
S. A. Marshall ◽  
P. L. Winokur ◽  
S. L. Coffman ◽  
W. W. Wilke ◽  
...  
Keyword(s):  
Clinical Laboratory ◽  
Test Methods ◽  
Error Rates ◽  
Clinical Isolates ◽  
Aminoglycoside Resistance ◽  
Gram Positive ◽  
University Of Iowa ◽  
Control And Prevention ◽  
Routine Clinical Laboratory ◽  
High Level

Modified MicroScan gram-positive MIC no. 8 panels (PM-8) were analyzed for their improved ability to detect vancomycin resistance (VR) and high-level aminoglycoside resistance (HLAR) in enterococci. A validation study design that utilized selected challenge strains, recent clinical isolates, and reproducibility experiments in a multicenter format was selected. Three independent medical centers compared the commercial panels to reference broth microdilution panels (RBM) and Synergy Quad Agar (QA). Resistance was verified by demonstration of VR and HLAR genes by PCR tests. The study was conducted in three phases. (i) In the challenge phase (CP), two well-characterized sets of enterococci were obtained from the Centers for Disease Control and Prevention; one set contained 50 isolates for VR testing and one contained 48 isolates for HLAR testing. In addition, a set of 47 well-characterized isolates representing diverse geographic areas, obtained from earlier national surveillance studies, was tested at the University of Iowa College of Medicine (UICM). (ii) In the efficacy phase (EP), each laboratory tested 50 recent, unique clinical isolates by all methods. (iii) In the reproducibility Phase (RP), each laboratory tested the same 10 strains by all methods in triplicate on three separate days. All isolates from the EP were sent to the UICM for molecular characterization of vanA, -B, -C1 , -C2–3 , and HLAR genes. In the CP, the ranking of test methods by error rates (in parentheses; very major and major errors combined, versus PCR results) were as follows: for high-level streptomycin resistance (HLSR), QA (12.0%) > PM-8 (5.2%) > RBM (1.6%); for high-level gentamicin resistance (HLGR), RBM (3.7%) > PM-8 (3.1%) > QA (2.6%); and for VR, RBM = QA (3.0%) > PM-8 (1.2%). In the EP, agreement between all methods and the reference PCR result was 98.0% for HLSR, 99.3% for HLGR, and 98.6% for VR. In the RP, the percentages of results ± 1 log2 dilution of the all-participant mode were as follows: for VR, 100% (PM-8), 98.9% (QA), and 90.0% (RBM); for HLSR, 99.6% (RBM), 98.5% (PM-8), and 82.2% (QA); and for HLGR, 99.6% (RBM), 99.3% (PM-8), and 98.1% (QA). The ability of the PM-8 to detect VR and HLAR in enterococci was comparable to those for reference susceptibility and molecular PCR methods and was considered acceptable for routine clinical laboratory use.

Dyeing processes of 100% bio-based and degradable polylactide/poly (hydroxybutyrate-co-hydroxyvalerate) textiles

2016 ◽  
Vol 87 (17) ◽  
pp. 2066-2075 ◽  
Author(s):  
ZH Zhang ◽  
ZQ Xu ◽  
XX Huang ◽  
XM Tao
Keyword(s):  
Polyethylene Terephthalate ◽  
Energy Cost ◽  
Textile Industry ◽  
Ph Value ◽  
Bath Temperature ◽  
Low Energy ◽  
Environment Friendly ◽  
Bursting Strength ◽  
Whole Process ◽  
Dyeing Process

This paper reports an investigation of dyeing processes of textiles made from a novel 100% bio-based and fully degradable polylactide/poly (hydroxybutyrate-co-hydroxyvalerate) (PLA/PHBV) fiber. The dye exhaustion, depth of shade and fastness, as well as bursting strength of dyed PLA/PHBV fabrics have been evaluated in terms of types and concentration of dyestuff, dyeing bath temperature, duration, liquor ratio and pH value. Finally, the energy cost of the whole dyeing process of the proposed material is calculated and compared with that of polyethylene terephthalate. The experimental results show that an excellent dyeing effect and bursting strength can be achieved by properly applied dyes (e.g. C.I. Disperse Orange 30, Red 74, and Blue 79) under optimal low-dyeing-temperature conditions (100℃, 10 min, pH 5, LR 30:1). In addition, considering the low energy cost during the whole process, PLA/PHBV fibers can be regarded as a promising and environment-friendly material for the textile industry.

scholarly journals ВЛАСТИВОСТІ ЕЛАСТИЧНИХ ОСНОВОВ'ЯЗАНИХ БИНТІВ

2020 ◽  
pp. 28-35
Author(s):  
О. П. Кизимчук ◽  
Л. М. Мельник ◽  
Р. Л. Сліпченко
Keyword(s):  
Test Methods ◽  
Standard Test ◽  
Raw Material ◽  
Polyester Yarn ◽  
Deformation Properties ◽  
Study Methodology ◽  
Knitted Structure ◽  
Relaxation Characteristics ◽  
Elastic Bandage

The market analysis of knitted elastic bandages in Ukraine, the investigation of the parameters and properties  of  the  most  common  products  and  their  comparison  as  well  as determination  of compliance to requirements are the main purposes of this study. Methodology. Standard test methods were used to experimental study the raw material composition, type of interlooping, structure parameters and relaxation characteristics of elastic bandages. Results. As a result of the study of the elastic bandage structure, it is found that all tested bandages are produced on Crochet knitting machine using four yarn systems. chain stitch with closed loop from is a ground interlooping. The ground guide bar is partially threaded with polyester yarn depending on the manufacturer. The requested level of elasticity is provided by elastomeric threads, which are used as longitudinal in-lay yarn with incomplete threaded of the guide bar and a diff erent repeat of its shifting behind the needles. The other two yarns systems are cotton yarn in several ends, which is laid across the bandage's entire width at both sides of the elastomeric yarn, ensuring its overlap and the combination of individual chain wales into the fabric. Obtained  experimental  data  of  the  parameters  and  elongation  of  elastic  bandages  of  diff erent manufactures allowed to establish their compliance with standardized values. It ensures the products functionality during usage. It is indicated that the yarn composition specifi ed by the manufacturers correlated  with  experimental  results.  The  percentage  of  the  elastomeric  thread  content  is  not  a determining characteristic of the bandage's stretchability since the elastic component of full deformation for all tested bandages exceeds 0.95. The residual component is less than 0.02. It is indicating high elastic properties and functionality. The practical signifi cance  of the work is confi rmed by the possibility of evaluating a bandage of a particular manufacturer based on the resulting array of their properties data. The results of the work expand the knowledge about the infl uence of the knitted structure on the parameters and deformation properties of elastic bandage.

Research for Wearability Test and Comprehensive Evaluation of Knitted Fabric Made of Jutecell Fiber

2012 ◽  
Vol 184-185 ◽  
pp. 1510-1514
Author(s):  
Jia Guang Meng ◽  
Jing Jing Li ◽  
Ning Li
Keyword(s):  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Test Methods ◽  
Fuzzy Mathematics ◽  
Knitted Fabric ◽  
Knitted Fabrics ◽  
Comprehensive Evaluation Method ◽  
Knitted Structure

The article briefly introduced the wearing characteristics and the test methods of jutecell fiber knitted fabrics of 7 kinds different structures, like comfortableness, fastness and other properties, and used the fuzzy mathematics comprehensive evaluation method to analyze and estimate the wearing characteristics of jutecell fiber knitted fabric. Finally reach a kind of knitted structure with the optimum wearing characteristic.

Research of Spindle Runout Testing Methods

2011 ◽  
Vol 121-126 ◽  
pp. 1455-1459 ◽  
Author(s):  
Yi Gao ◽  
Guo Hua Cao ◽  
Hong Ji Xu ◽  
Zheng Lin Yu
Keyword(s):  
Measurement System ◽  
Test System ◽  
Test Methods ◽  
Displacement Sensor ◽  
Sensor Calibration ◽  
Laser Displacement Sensor ◽  
Testing Methods ◽  
Calibration Experiment ◽  
Calibration Device ◽  
Machine Spindle

The paper aims at the analysis of machine spindle runout characteristics and designs of a laser displacement sensor in non-contact spindle runout measurement system. To ensure accuracy, we designed the laser displacement sensor calibration device, and the test calibration experiment was carried out by using laser displacement sensor. Experimental results showed that the test methods met the accuracy requirements of test system.

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