Standard Laboratory Test Methods Research Articles

THE 4th ASCOPE LABORATORY TEST CORRELATION PROGRAMME FOR FUELS BY SAMPLE CODES : A.2/X/82, D.2/Y/82

The properties of commercial products are measured by standardized laboratory test methods to check their Conformance to specification Two or more measurements of some property of a specific sample by any given test method usually will not givee precisely the same answer. Therefore, Laboratory test correlation of the specific sample is necessary to be done on the expected precision, accuracy of the test results and the uniformity of interpretative, to step on the credibility of the testing Laboratory. This is a paper on the conduct and the results of the fourth ASCOPE (ASEAN Council on Petroleum) Cor mellation Programme for fuels were carried out on two kinds of samples.

Effects of simulated aging on cushion performance measured using standardized laboratory test methods

ABSTRACT Standardized test methods providing wheelchair cushion performance characteristics can aid cushion design and selection. Assessment of the changes in performance that occur with aging provides additional information. Test methods published by the International Organization for Standardization were applied to a cohort of 21 cushions of varying design and construct to assess changes in performance due to simulated aging. Performance tests measured immersion, envelopment, stiffness, impact response, and pressure distribution properties. Means of test outcome metrics pre- and post-aging are presented, and changes in the metrics due to aging are analyzed using linear mixed models. Statistically significant changes were found for outcome measures for each performance test. The minimum aging method simulating 18–24 months use had a significant effect on cushion performance. Changes to loaded contour depth, envelopment, pressure mapping, hysteresis, horizontal stiffness, and 10% force deflection characterization test metrics indicated decreased cushion performance. The simulated aging method resulted in cushion stiffening and reduced immersion, pressure distribution, and stability performance. Together, these changes may increase a user’s risk for pressure injuries.

Antimicrobial Sensitivity and Resistance Pattern in Surgical Site Infections following Gynaecological and Obstetrical Operations

Background: Surgical Site Infections (SSIs) are one of the common problem in obstetrical and gynaecological operations. It is related to the increasing cost, morbidity and mortality. Objectives of this study were, find out the rate of surgical site infection, frequencies of various pathogens causing SSIs and their antibiotic sensitivity and resistance pattern in gynaecological and obstetrical operations in the Department of Obs & Gynae Chittagong Medical College, Chattogram.
 Materials and methods: This hospital based prospective longitudinal study was carried from January 2021 to July 2021 in the Department of Gynaecology and Obstetrics, Chittagong Medical College, Chattogram, Bangladesh. After operation, patients’ surgical wounds were inspected first on 5-7 th day and there after weekly up to 30 postoperative- day. If there had any features of wound infection, pus or discharge would have been collected from the wound. A total 100 pus or discharge were collected from the wound after obtaining written informed consent and according to the inclusion and exclusion criteria. Samples were processed following the standard laboratory technique.The isolates were identified by colony morphology, Gram’s staining and biochemical test according to standard laboratory test methods.
 Results: In this study most of the surgical site infections were caused by gram negative organisms (90%). Pseudomonas aeruginosa (36%) was the commonest organism responsible for SSIs. Staphylococcus species were responsible for SSIs in 6% of cases. In case of gram negative bacteria Amikacin and Imipenem were sensitive to about 89% and 91% microorganisms. While in case of gram positive organisms it were about 78% and 89%. Commonly used antibiotics in our set up included Ceftriaxone, Cefixime, Ciprofloxacin and Cefuroxime were sensitive in gram positiveorganisms 45%, 33%, 33% and 33% respectively. Butin case of gram negative organisms it were 76%, 63%, 79%, and 66%.
 Conclusion: Surgical site infections are the reflection of quality of hospital services. Once it was thought that the organisms responsible for the SSIs were derived from normal bacterial flora of the skin. But in last few years, it has been shown that the gram negative organisms are the main pathogens responsible for SSIs. Most of them are derived from the hospital environment.So the strict surgical ritual has come to mainstay in the management of the patients instead of being used antibiotics irrationally, which not only increases the chance of resistance to the micro-organisms but also glooming our future.
 JCMCTA 2021 ; 32 (2) : 115-121

Performance evaluation of waste palm oil fiber reinforced stone matrix asphalt mixtures using traditional and sequential mixing processes

Asphalt pavement in tropical countries like Malaysia faces severe distresses. Thus, the use of more resistant and stable asphalt mixtures on the surface layer like stone matrix asphalt concrete (SMAC) is encouraged. The performance-related properties of asphaltic concrete are highly influenced by the mixing process and the asphalt mixtures homogeneity and segregation are pivotal issues affecting asphaltic concrete production. Malaysian palm oil industry generates a large amount of waste palm fiber (WPOF) which are largely discarded. This study investigates the feasibility of utilizing WPOF as a stabilizer in SMAC and evaluates the influence of two different mixing processes (traditional and sequential) on its properties The SMAC mixtures were reinforced with various content of WPOF, 0–0.6% by weight of the total mix and evaluated for volumetric and mechanical properties. Several standard laboratory test methods were used to examine the mixtures: Marshall properties, drain down test, Cantabro, stiffness modulus, moisture damage test. The study revealed sequential mixing as a more viable mixing alternative for SMAC, as it shows lower drain down, air void, and optimum bitumen content with higher Marshall stability and voids in mineral aggregate values. While for the mechanical properties the sequential mixing shows higher moisture resistances, stiffness modulus, and less Cantabro loss for all mixture’s types compared to the convention blends. It was observed that the optimum WPOF dosage is 0.3% for both mixing processes, Though, the sequential mixing shows improved mechanical properties. These improved properties are probably due to improving coating and proper dispersion of mixing materials during the mixing process. In conclusion, utilizing WPOF as stabilizers improve SMAC mixtures properties whereas, the sequential process produces better properties even at marginally lower OBC and mixing time.

On-machine visible dirt measurement on moving sheets and the relationships to standard laboratory methods

There has been a proliferation of new sensors to measure on-machine dirt specks that employ different technologies and methodologies to perform measurements. The differences in the on-machine technologies are discussed in terms of the TAPPI and ISO standard laboratory test methods with respect to dirt detection using light reflected from, or light transmitted through, the sheet. Also discussed are the requirements for measuring statistically representative areas of the sheet; the difference between the dirt physical size and Equivalent Black Area (EBA) size; and the implication of these issues when specifying cleanliness acceptance criteria. This technical brief describes on-machine visible dirt measurement’s relationship to standard laboratory testing.

SPECIFIC EVALUATION METHODOLOGY OF RAILWAY BALLAST PARTICLES’ DEGRADATION

Purpose. The most railway lines in the world have so called traditional ballasted superstructure. The authors think that it is important to learn about the process of ballast degradation. There are only two types of standardized laboratory test methods in the EU to assess railway ballast particle degradation and describe the rock physic characteristics, but are not suitable for modelling the railway stress-strain circumstances of ballast materials, and they particles. In this paper the authors represent some conclusions from their research that the authors experienced during their individual fatigue laboratory test and from new additional tests. With these kind of testing methods, the deterioration process of railway ballast particles can be assessed more realistic and precisely. Methodology and new directions. There are two types of laboratory tests which are presented in this article. The first one was performed by using a shear box with a special layer structure that is loaded by dynamic, pulsating force; while the second one was executed by using a 140 mm diameter HDPE tube with its original closing element that is loaded by ZD-40 machine. Findings and problems. There is a development after the R&D work made and published in 2014, in 2017 and 2018 years the ballast particle deterioration process is given according to more intermediate fatigue cycles with individual measurements that show more precise «picture» about the full particle degradation, i.e. breakage process. The authors give more accurate correlation functions between the calculated parameters and load cycles during fatigue. However, there are many factors in the test that need to be improved in the future. Therefore, the authors have discovered other additional tests. Originality. The most important goal of the authors that supplement the currently used regulation with new measurement methods. Practical value The authors’ developed and new methods may serve as a basis for a future instruction or regulation. The publishing of this paper was supported by EFOP 3.6.1-16-2016-00017 project.

Geotechnical laboratory testing and data interpretation for biosolids and sewage sludge

Biosolids and sewage sludge are difficult, challenging and unconventional geomaterials with some distinctive properties, including extremely high water content and plasticity; low particle density; high organic content; very high compressibility, creep and strain rate dependence of strength; a viscous gel-like pore fluid phase; extremely low permeability coefficient; and a propensity to degrade, producing copious amounts of biogas. The geotechnical properties and behaviour of these materials have been comprehensively reviewed in a companion paper previously published in this journal. The purpose of the present review paper is to describe necessary procedural modifications to standard geotechnical laboratory test methods, including associated analyses and data interpretation procedures, to obtain meaningful determinations of their index, compaction, compression, consolidation and permeability properties and their undrained and effective-stress strength parameter values. Specific aspects investigated include a modified curve-fitting technique for interpreting oedometer strain–time data, rapid and accurate means for undrained strength measurement and the significance and effects of ongoing biodegradation for long-term tests, as well as the corrosive nature of these materials. Many of the procedural modifications to geotechnical laboratory testing and nuances in the data interpretation presented in this paper should be transferable to the testing of other biodegradable soil and soil-like materials.

Experimental investigation on static and dynamic resilient moduli of compacted fine soil

To investigate the static and dynamic resilient modulus of fine soil, and adapting to the new design code and maintenance system of highway subgrade in China, a series of static and dynamic tests were carried out according to the standard laboratory test methods (JTG E40-2007 and JTG D30-2015, respectively). The effects of initial water content, compactness and freeze-thaw cycles on the static and dynamic resilient moduli of fine soil were investigated and analyzed. Experimental test results show that with increasing water content, dry density and freeze-thaw cycles, the static moduli reduces about 10.2%~40.0%, 14.4%~45.5%, and 24.0%~50.3%, and dynamic moduli reduces about 10.9%~90.8%, 2.5%~38.4%, and 0.0%~46.0%, respectively. Then, the empirical mathematical relationship between static and dynamic resilient moduli was established under different water content, dry density and freeze-thaw cycles. The investigation results can be used to determine the dynamic modulus of fine soil by widely used static modulus, which could meet the requirement of adopting dynamic modulus index in new specification.

An Improved Pollution Testing Methodology for Polymeric Insulators: Analysis on Surface Coating and Flashover Voltage Under Solid Layer Test

Polymeric insulators have found application worldwide in outdoor insulation system due to their better pollution performance. Since there are no standard laboratory test methods to analyse pollution performance of polymeric insulators, selection and dimensioning of proper insulator is still confusion for engineers and utilities. IEC and CIGRE working groups have recently suggested a test method for solid layer pollution testing of polymeric insulators. The uniformity of pollutant coating over hydrophobic insulator surface was not consistent with CIGRE Round Robin Test procedure. In this research work, a method of soaking the insulators in water as a part of preconditioning before actual pollutant spray was adopted and uniformity of coating was compared with CIGRE round robin test procedure. Critical analysis has been made on the loss and recovery of hydrophobicity characteristics on silicone insulators and its ability to transfer the hydrophobicity to pollution layer were observed and recorded over a period of 15 days with the proposed coating method. Solid layer pollution test was carried out on 66 kV long-rod insulators with the proposed test procedure and the results were compared with CIGRE procedure. 50% Flashover Voltage (U50%) of the insulator was determined before and after withstand test for both the test methods and standard deviation was calculated. The variation in the flashover voltage values has been calculated before and after withstand test. From the results, it’s been observed that, the hydrophobicity character was not influenced to the pollution layer in the given recovery period but the recovery time had an impact on flashover voltage. The deviations in flashover voltage value compared before and after withstand tests, found to be within 5% for both CIGRE procedure and modified test procedure.

SPECIFIC ASSESSMENT METHOD OF RAILWAY BALLAST PARTICLE DEGRADATION BASED ON UNIQUE LABORATORY TEST

Purpose. There are specific, standardized laboratory test methods to assess railway ballast particle degradation; they are the Los Angeles (EN 1097-2) and the Micro-Deval abrasion (EN 1097-1) tests. These testing methods can’t take into consideration the real railway stress-strain circumstances of ballast materials, and they particles. In this paper the authors represent a specific laboratory fatigue breakage test of railway ballast materials. With this kind of testing method, the deterioration process of railway ballast particles can be assessed more realistic and precisely. Methodology. A special layer structure is built-up with elastic sublayer system and 30 cm thick ballast samples (from two different type andesite base rocks) that is loaded by dynamic, pulsating forces. Particle size distribution functions have to be recorded before and after a more million cycle fatigue test, but intermediate measurements are also executed. The measured data should be processed, and different parameters have to be calculated that are offered by international literature and researches. The test doesn’t consider the particle breakage due to hand-made and machine-made tamping, but it can simulate particle degradation due to more years’ railway traffic in laboratory circumstances. Findings. There is a development after the R&D work made and published in 2014: in 2017 and 2018 years the ballast particle deterioration process is given according to more intermediate fatigue cycles with individual measurements, that show more precise «picture» about the full particle degradation, i.e. breakage process. The authors give more precise correlation functions between the calculated parameters and load cycles during fatigue. Originality. The paper summed up the results of a specific developed laboratory test method for assessment of the breakage process of railway ballast particles according to two different railway ballast materials from andesite base rocks. Practical value. The results help with the calculation of approximate time interval of required ballast screening (cleaning) work in the future. This research is supported by the UNKP-17-4 New National Excellence Program of Ministry of Human Capacities.

SPECIAL LABORATORY TESTING METHOD FOR EVALUATION PARTICLE BREAKAGE OF RAILWAY BALLAST MATERIAL

Purpose. There are special, standardized laboratory test methods to evaluate railway ballast particle breakage; they are the Los Angeles and the Micro-Deval abrasion test. The authors opine that these methods aren’t the most adequate methods to assess the real ballast particle degradation because in reality never occurs these kinds of stresses and strains (i.e. particles in a rotating drum with or without steel balls and with or without water). A new laboratory test procedure is needed. The authors attempted to configure an adequate one in 2014, it is detailed in the paper, as well as the initial results and improvement possibility. This test method is related to dynamic pulsating test, the particle size distributions (PSD) had to be determined before and after fatigue. In 2017-2018 the research is supported by ÚNKP-17-4 program. Methodology. Multi-level steel box is utilized with a special layer structure, detailed in the paper. Five different types of railway ballast samples were tested. PSDs were defined, and regarding to the results relationship between ballast particle degradation values (according to Los Angeles and Micro-Deval abrasion tests, as well as this newly developed laboratory test method) was searched, as well as time interval between necessity railway ballast cleaning work was also calculated. Findings. The authors sentenced the results regarding to the self-developed laboratory test method that is able to assess the particle degradation and time interval between railway ballast cleaning work more precisely related to the real railway operation circumstances. Relationship was determined between particle breakage according to standardized and unique (non-standardized) laboratory test methods. Originality. The paper summarized the results a newly developed laboratory test method for evaluation of the degradation of railway ballast particles. Practical value. It sentenced the possibility to improve the measurements and assessments regarding to the research phase supported by the ÚNKP-17-4 project.

Experiments to provide the scientific-basis for laboratory standard test methods for firebrand exposure

Firebrand ignition of structures is a major factor in large outdoor fire spread. Standard laboratory test methods are required to evaluate and compare the performance of different building elements and/or vegetative fuels ability to resist firebrand ignition. It is important to determine full-scale assembly performance when exposed to firebrand showers since weak points in a given assembly can be investigated. Such studies will lead to determining the necessary configuration of building component mock-ups that can be used in standard laboratory test methods. The basis of this paper is to present a comparison of results from full-scale roofing assembly experiments, to mockups using the recently developed experimental capability at National Research Institute of Fire and Disaster (NRIFD). The results demonstrated that similar firebrand penetration behavior/trends were observed for mock-ups of full-scale roofing assemblies, as compared to experiments where full-scale roofing assemblies were used, all under similar wind speeds. The experimental findings presented in this paper represent an important step to develop reduced-scale test methods for firebrand exposure.

Laboratory pelletization of hydrochar from woody biomass

Pelletization is an important method for increasing the mass and energy density of raw woody biomass materials and improving their handling and transport. Further increases in mass and energy density are possible by thermal pretreatment of raw biomass prior to pelletization, via torrefaction or hydrothermal carbonization (HTC). In this work, standardized laboratory test methods were developed, validated, and utilized to provide reliable assessments of pellet properties – both before and after immersion in water, as water immersion is a severe test of pellet durability. Pellets of raw or torrefied woody biomass cannot survive a standard tumbler durability test after water immersion, while pellets of hydrochar (produced by HTC processing) demonstrate excellent durability under these conditions. In part, the excellent pellet binding behavior of hydrochar is due to resins produced in the HTC process. Hydrochar can also be used as a binder to substantially improve the pelletization of raw wood and torrefied wood.

Synthesis and characterization of modified cottonseed oil based polyesteramide for coating applications

Cottonseed oil fatty amide (CFA) was prepared in the laboratory by base catalyzed aminolysis of cottonseed oil. Further it was reacted with phthalic acid to obtain polyesteramide (CPEA) and modified by post reacting with vinyl acetate monomer in varying ratios of 4:1, 3:1 and 2:1 in the presence of t-butyl hydroperoxide as an initiator. The incorporation of vinyl acetate in CPEA was analyzed using FTIR, 1H NMR and 13C NMR spectral techniques. The physico-chemical properties such as iodine value, specific gravity and refractive index were determined by standard laboratory test methods. Mechanical, chemical resistance and other coating properties of the coatings synthesized from CPEA and modified CPEA applied on mild steel substrates were also studied by standard methods. Thermal stability and curing behavior of modified CPEA were determined by thermo gravimetric analysis (TGA) and differential scanning calorimetric (DSC) techniques. It was observed that modification of polyesteramide improved the curing, mechanical and chemical performance of CPEA films. It was found that among the CPEA:vinyl acetate ratios, 2:1 ratio exhibited the best results.

Laboratory evaluation of wood-based composites treated with alkaline copper quat against fungal and termite attacks

Vacuum-impregnation with alkaline copper quat (ACQ) was applied as a post-treatment to five commercially-available wood-based composites (approximately 12-mm thick), including softwood plywood (SWP), hardwood plywood (HWP), medium density fiberboard (MDF), oriented strand board (OSB) and particleboard (PB). In general, ACQ-treated wood-based composites were not as resistant to biological attack as treated Cryptomeria japonica sapwood blocks, possibly due to the uneven distribution of preservative in the composites. Untreated and treated composites were tested for their resistance to two decay fungi (brown-rot fungus Fomitopsis palustris and white-rot fungus Trametes versicolor) and the subterranean termite Coptotermes formosanus by Japanese standardized laboratory test methods. Untreated MDF was the most resistant to both biological attacks, followed by PB, which was less resistant to C. formosanus. ACQ did not adequately protect SWP from F. palustris or termite, or OSB from F. palustris or T. versicolor even at the highest test retention of 5.2 kg/m 3, whereas the biological resistance of HWP was reasonably improved by ACQ. Since cut-end-coated composites treated at higher retentions of both ACQ and copper azole performed much better than uncoated materials, cut-ends were considered to provide decay fungi and termites with easy access or penetration. These findings support the importance of remedial treatment of processed building components at construction sites.

Biological performance of copper azole-treated wood and wood-based composites

Abstract Vacuum-impregnation with copper azole was applied as a post-treatment to five commercially available wood-based composites with thicknesses of approximately 12 mm, such as softwood plywood (SWP), hardwood plywood (HWP), medium density fiberboard (MDF), oriented strand board (OSB), and particleboard (PB). Untreated and treated composites were tested for their resistance to decay fungi (brown rot fungus Fomitopsis palustris and white rot fungus Trametes versicolor) and the subterranean termite Coptotermes formosanus by Japanese standardized laboratory test methods. Untreated MDF was highly resistant to both biological attacks and seemed to require no preservative treatment under less hazardous conditions, i.e., under protected and above-ground applications, with possible occasional wetting. PB was ranked second, and needed further protection only against C. formosanus. Copper azole did not adequately protect SWP from F. palustris and termite. OSB was not protected either against F. palustris and T. versicolor even at a concentration level of 1 kg copper azole per m3 in contrary to blocks of Cryptomeria japonica sapwood, which was protected at these concentration levels. The biological resistance of HWP was reasonably improved by copper azole. The performance of wood-based composites treated with copper azole, which was inferior to the biological resistance of treated C. japonica sapwood blocks, might depend on the thickness or layer profile, density as a result of porosity, uneven distribution of the preservative in the composites, and the susceptibility of the component raw materials.

Seismic Test Methods for Architectural Glazing Systems

An ongoing effort is being made at the University of Missouri-Rolla to develop standard laboratory test methods and codified design procedures for architectural glass under seismic loadings. Recent laboratory work has yielded some promising results regarding the development of an appropriate seismic test method for architectural glass, as well as identifying ultimate limit states that quantify the seismic performance and damage thresholds of various glass types. Specifically, a straightforward “crescendo-like” in-plane dynamic racking test, performed at a constant frequency, has been employed successfully. Two ultimate limit states for architectural glass have been defined: (1) a lower ultimate limit state corresponding to major glass crack pattern formation; and (2) an upper limit state corresponding to significant glass fallout. Early crescendo tests have yielded distinct and repeatable ultimate limit state data for various storefront glass types tested under dynamic racking motions. Crescendo tests will also be used to identify and quantify serviceability limit states for architectural glass and associated glazing components under dynamic loadings. These limit state data will support the development of rational design procedures for architectural glass under seismic loadings.

The use of earthworms in environmental management

During the past 25 yr, research by the authors at Rothamsted Experimental Station investigated many aspects of the utilization of earthworms in land improvement and environmental management. Results of some of these investigations are summarized in this paper with the aim of illustrating the general principles of how earthworm populations can be manipulated and managed for environmental improvement. The use of earthworms in land improvement and reclamation: we investigated the effects of inoculating earthworms of the species Lumbricus terrestris L., Aporrectodea longa (Ude), Aporrectodea caliginosa (Sav.) and Allolobophora chlorotica (Sav.) into intact soil profiles in the laboratory, plots on direct-drilled, arable land in the field and newly-capped waste disposal sites that had few or no earthworms. In all these studies the earthworms increased significantly in number and rate of growth and yield of plants growing on the inoculated sites. Earthworms for inoculation were obtained by field collection after watering soil with dilute formaldehyde solution. The use of earthworms in organic waste management: the life cycles and productivity of Eisenia fetida (Sav.), Eudrilus eugeniae (Kinberg), Perionyx excavatus (Michaelsen) and Dendrobaena veneta (Rosa), and their potential in processing animal and plant wastes, from sewage, agricultural, domestic, urban and industrial sources are summarized. The preprocessing of wastes, their population ecology, optimum stocking rates, the mechanization of processing and utilization of the product are discussed. Results of experiments on the effects of temperatures of 10, 15, 20 and 25°C and a range of soil moisture contents of 70, 75, 80, 85 and 90% on the growth, cocoon production and cocoon hatching of the four species are summarized. The use of earthworms in assessment of the environmental effects of chemicals: earthworms can be used as key indicators to predict the effects of chemicals on other soil invertebrates. Methods of testing chemicals against earthworms in field and laboratory are reviewed. Two standardized laboratory test methods, one exposing earthworms to chemicals on filter paper and one to chemicals in artificial soils are described, and the median lethal concentration (LC 50) for chloracetamide, pentachlorophenol, chlordane, carbaryl, potassium bromide, copper sulfate and trichloracetic acid calculated, based on assays done in 34 laboratories. The relevancy of the two tests in environmental toxicity testing is reviewed.

A User's Approach to Qualification of Dynamic Seals for Sour-Gas Environments

Summary The selection and performance of dynamic-seal materials for use in aggressive, subsurface, sour-gas environments have often been unsuccessful and resulted in costly field failures. Seal performance is adversely affected by H2S, CO2, high temperature, corrosion inhibitors, and dynamic movement. Standard laboratory test methods to evaluate elastomeric materials for subsurface sealing applications have not allowed reliable prediction of seal behavior in actual field service. This paper presents a new and unique test apparatus that can be used to evaluate dynamic-seal materials and to qualify entire seal-stack configurations for subsurface sour-gas environments.

An Evaluation of the Performance of Thirty-Three Residential-Stoker Coals

Abstract This paper is based upon experience gained from evaluation tests, sponsored by individual coal producers during the past 12 years, to determine the suitability of various coals for use in residential underfeed stokers of the clinkering type. The conclusions reached through the evaluation tests are in general agreement with the marketing experiences of the producers in the field. Comparisons are also made between the characteristics of the coals as determined by the evaluation tests and data determined by standard laboratory-test methods. Correlation in this regard was not good.