scholarly journals How Does Experimental Design Modify the Result of Daphnia magna Heartbeat Rate Test? ─ Analyses of Factors Affecting the Sensitivity of the Test System

2017 ◽  
Vol 62 (3) ◽  
pp. 257-264
Author(s):  
Ildikó Fekete-Kertész ◽  
Tamás Stirling ◽  
Orsolya Ullmann ◽  
Éva Farkas ◽  
Csaba Kirchkeszner ◽  
...  
Keyword(s):  
Experimental Design ◽  
Daphnia Magna ◽  
Exposure Time ◽  
Tap Water ◽  
Harmful Effect ◽  
Test System ◽  
Test Method ◽  
Test Medium ◽  
Heartbeat Rate ◽  
Rate Test

Development of an unconventional test method involves usually the comparison of biological responses under a variety of test conditions. The quality of these biological methods relies on an appropriate experimental design. The Daphnia magna heartbeat rate as a physiological endpoint for assessing aquatic pollution has been of minor interest so far; nonetheless, this could be an early and sensitive indicator of the harmful effect of micropollutants. Our aim was to set up the optimal experimental design of the heartbeat rate test. The studied factors were the composition of the test medium, the age of the test organism, and the exposure time, at triclosan concentrations between 0.2–2000 μg/L. According to the evaluation of test results the optimal test condition for the heartbeat rate test assumes tap water as test medium, 10-day-old test organisms and 48 h exposure time.

Evaluation of the disinfection potential of low chlorine concentrations in tap water using immobilised enterococcus faecium in a continuous flow device

1997 ◽  
Vol 35 (11-12) ◽  
pp. 77-80 ◽  
Author(s):  
A. Wiedenmann ◽  
M. Braun ◽  
K. Botzenhart
Keyword(s):  
Distribution System ◽  
Enterococcus Faecium ◽  
Continuous Flow ◽  
Tap Water ◽  
Test System ◽  
Batch Experiments ◽  
Membrane Filters ◽  
Upper Limit ◽  
Flow Device ◽  
Faecal Streptococci

A simple continuous flow device in which bacteria were immobilised on membrane filters and flushed with tap water with free chlorine residuals of 0.05, 0.1, 0.2 and 0.4mg/L at pH 7.7 and 10°C, has been used for disinfection experiments with faecal streptococci. A 99.99% reduction of Enterococcus faecium was observed between 3.4–5.2min (0.05mg/L), between 2.8–4.1min (0.1mg/L), between 1.7–3.1min (0.2mg/L) and between 0.8–2.1min (0.4mg/L). CT-products covered a range of 0.17 (0.05mg/L, lower limit) up to 0.85mg/L/min (0.4mg/L, upper limit). The test system is suggested as a more reliable alternative to batch experiments when the disinfection potential of low chlorine concentrations acting for several minutes has to be evaluated. The system cannot be used to demonstrate exact reduction kinetics but it allows the calculation of CT values and the evaluation of the disinfection potential of chlorinated water at any point of a distribution system where initial chlorine concentrations may have already remarkably declined.

scholarly journals Rock Stress Measurements for Unlined Pressure Tunnels: A True Triaxial Laboratory Experiment to Investigate the Ability of a Simplified Hydraulic Jacking Test to Assess Fracture Normal Stress

2021 ◽  
Author(s):  
Henki Ødegaard ◽  
Bjørn Nilsen
Keyword(s):  
Normal Stress ◽  
Test Method ◽  
Sudden Increase ◽  
Normal Stresses ◽  
True Triaxial ◽  
Step Rate ◽  
Stress Measurements ◽  
Fracture Closure ◽  
Rate Test ◽  
Hydraulic Jacking

AbstractTo avoid hydraulic failure of unlined pressure tunnels, knowledge of minimum principal stress is needed. Such knowledge is only obtainable from in situ measurements, which are often time-consuming and relatively costly, effectively limiting the number of measurements typically performed. In an effort to enable more stress measurements, the authors propose a simplified and cost-effective stress measuring method; the Rapid Step-Rate Test (RSRT), which is based on existing hydraulic testing methods. To investigate the ability of this test to measure fracture normal stresses in field-like conditions, a true triaxial laboratory test rig has been developed. Hydraulic jacking experiments performed on four granite specimens, each containing a fracture, have been performed. Interpretation of pressure-, flow- and acoustic emission (AE) data has been used to interpret fracture behaviour and to assess fracture normal stresses. Our experimental data suggest that the proposed test method, to a satisfactory degree of reliability, can measure the magnitude of fracture normal stress. In addition, a clear correlation has been found between fracture closure and sudden increase in AE rate, suggesting that AE monitoring during testing can serve as a useful addition to the test. The rapid step-rate test is also considered relevant for field-scale measurements, with only minor adaptions. Our findings suggest that the RSRT can represent a way to get closer to the ideal of performing more testing along the entire length of pressure tunnel, and not only at key locations, which requires interpolation of stress data with varying degree of validity.

scholarly journals Evaluation of a Preclinical Blood Test for Scrapie in Sheep Using Immunocapillary Electrophoresis

2006 ◽  
Vol 89 (3) ◽  
pp. 720-727 ◽  
Author(s):  
Roy Jackman ◽  
David J Everest ◽  
Mary Jo Schmerr ◽  
Mohammed Khawaja ◽  
Pat Keep ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
Prion Protein ◽  
Clinical Signs ◽  
Test System ◽  
Buffy Coat ◽  
Infected Sheep ◽  
Test Method ◽  
Peptide Sequence ◽  
Transmissible Spongiform Encephalopathies ◽  
Blood Samples

Abstract An analytical method is described for detection of endogenous disease-associated prion protein in the buffy coat fraction from the blood of sheep infected with scrapie. The method has been improved and evaluated for its performance in the preclinical diagnosis of ovine transmissible spongiform encephalopathies. The test system uses a protocol for sample preparation that includes extraction and concentration and a test method that uses a liquid-phase competitive immunoassay for prion protein. Antibodies directed to a peptide sequence at the C-terminus of the prion protein (PrP) and a fluorescein-labeled peptide conjugate are used in the assay. Free zone capillary electrophoresis with laser-induced fluorescence for detection is used to separate the antibody-bound fluorescently labeled peptide and free labeled peptide. In this assay, the PrP competes with the fluorescently labeled peptide for limited antibody binding sites, which results in a reduction of the peak representing the immunocomplex of the antibody bound to the fluorescently labeled peptide. When blood samples from scrapie-infected sheep aged 712 months and of the scrapie-susceptible PrP genotypes VRQ/VRQ and VRQ/ARQ were analyzed, the abnormal PrP was found in blood samples. These results correlated with the post-mortem diagnosis of scrapie. The sheep were preclinical and appeared normal at the time of testing but later died with clinical disease approximately 12 months after testing. In older animals, and those with clinical signs, a smaller percentage of animals tested positive. This study has demonstrated that this technology can be used as a sensitive, rapid preclinical test to detect the disease-associated PrP in the blood of scrapie-infected sheep. Improvements in the extraction protocol and capillary electrophoresis conditions will enhance the robustness of this test.

Hypoxic tolerance of Chinese black sleeper Bostrichthys sinensis embryos at heartbeat stage

2006 ◽  
Vol 86 (6) ◽  
pp. 1473-1476 ◽  
Author(s):  
Shixi Chen ◽  
Wanshu Hong ◽  
Wei Zhou ◽  
Qiyong Zhang
Keyword(s):  
Dissolved Oxygen ◽  
Exposure Time ◽  
Hypoxic Conditions ◽  
Hypoxic Tolerance ◽  
Heartbeat Rate ◽  
Bostrichthys Sinensis ◽  
Oxygen Concentrations

Tolerance of hypoxia in Chinese black sleeper (Bostrichthys sinensis) embryos at heartbeat stage was examined at different oxygen concentrations. Embryonic response to hypoxic conditions was expressed in terms of the intensity of variation in heartbeat rate (V). Exposure of the embryos at 25°C to 0.5, 1.0 and 1.5 mg/l dissolved oxygen (DO), caused bradycardia, which was developed within the first 10 min of hypoxia, followed by a plateau, and lasted until termination of the hypoxia. The V values were significantly affected by DO concentrations (P<0.01). Exposure of the embryos to 0.2 mg/l DO at 25°C caused a periodic heartbeat (including a period of heartbeat and a period of silence). This phenomenon was first recorded in the present study. During the period of heartbeat, the heartbeat rates were faster at first (147±5 beats per min), and then decreased gradually until the period of silence. As the exposure time increased, the duration of heartbeat was prolonged significantly from 43.4±2.4 second to 126.2±8.2 second (P<0.01), and the duration of silence was also prolonged significantly from 68.0±5.5 second to 247.9±11.5 second (P<0.01). At the beginning of exposure, the primary heartbeat rates displayed tachycardia, and their V values were significantly lower than the V values of average heartbeat rates (P<0.05). However, the V values were not significantly different between primary heartbeat rate and average heartbeat rate after 90 min exposure (P>0.05).

The Research of IC Test Based on LTX-77 Test System

2014 ◽  
Vol 496-500 ◽  
pp. 1176-1179
Author(s):  
Li Tan ◽  
Yu Fang
Keyword(s):  
Test Object ◽  
Test System ◽  
Test Method ◽  
Test Results ◽  
Analog Ic ◽  
Test Platform ◽  
Logic Functions ◽  
Actual Test ◽  
Ic Test

LTX-77 test system is a large IC test system that is used for various kinds of analog IC, digital IC and analog digital mixed IC. It can be used to test DC parameters, AC parameters and logic functions. In the paper, the IC test platform is LTX-77 test system. IC ADC0804 was tested as the test object. The test method of IC is described in the view of actual test. The test results show that the test system is convenient and accurate, which has important practical value for IC manufacturers and users.

Design on Hierarchical Testing System for Unmanned Ground Vehicles

2011 ◽  
Vol 346 ◽  
pp. 817-822 ◽  
Author(s):  
Xin Li ◽  
Guang Ming Xiong ◽  
Yang Sun ◽  
Shao Bin Wu ◽  
Jian Wei Gong ◽  
...  
Keyword(s):  
Evaluation System ◽  
Test System ◽  
Unmanned Vehicles ◽  
Intelligent Vehicles ◽  
Test Method ◽  
Unmanned Ground Vehicles ◽  
Ground Vehicles ◽  
Test Environment ◽  
Test And Evaluation ◽  
Comprehensive Test

The test system for technical abilities of unmanned vehicles is gradually developed from the single test to comprehensive test. The pre-established test and evaluation system can promote the development of unmanned ground vehicles. The 2009 Future Challenge: Intelligent Vehicles and Beyond (FC’09) pushed China's unmanned vehicles out of laboratories. This paper proposed to design a more scientific and comprehensive test system for future competitions to better guide and regulate the development of China's unmanned vehicles. According to the design idea of stage by stage and level by level, the hierarchical test content from simple to advanced, from local to overall is designed. Then the hierarchic test environment is established according to the levels of test content. The test method based on multi-platform and multi-sensor is put forward to ensure the accuracy of test results. The testing criterion framework is set up to regulate future unmanned vehicle contests and to assess the unmanned vehicles scientifically and accurately.

Plant Constituents Interfering with Human Sex Hormone-Binding Globulin. Evaluation of a Test Method and Its Application to Urtica dioica Root Extracts

1995 ◽  
Vol 50 (1-2) ◽  
pp. 98-104 ◽  
Author(s):  
Dietmar Ganßer ◽  
Gerhard Spiteller
Keyword(s):  
Test System ◽  
Binding Activity ◽  
Urtica Dioica ◽  
Sex Hormone ◽  
Test Method ◽  
Sex Hormone Binding Globulin ◽  
Hormone Binding ◽  
Root Extracts ◽  
Plant Constituents ◽  
Octadecenoic Acids

Abstract A test system is described, which allows the search for compounds interfering with human sex hormone-binding globulin (SHBG) even in complex plant extracts. The method has been evaluated and applied to Urtica dioica root extracts. The lignan secoisolariciresinol (5) as well as a mixture of isomeric (11 E)-9,10,13-trihydroxy-11-octadecenoic and (10 E)-9 ,12,13-trihydroxy-10-octadecenoic acids (3 and 4, resp.) were demonstrated to reduce binding activity of human SHBG. Methylation of the mixture of 3 and 4 increased its activity about 10-fold.

Research on a Test Method of Dynamic Force of Jet Elements

2014 ◽  
Vol 574 ◽  
pp. 154-159 ◽  
Author(s):  
Zhong Yang ◽  
Xiao Xian Yao ◽  
Dong Xu Zhang
Keyword(s):  
Delay Time ◽  
Simple Structure ◽  
Mathematic Model ◽  
Test System ◽  
Processing Method ◽  
Test Method ◽  
Dynamic Force ◽  
Simple Method ◽  
Pendulum Test ◽  
Testing Condition

According to the characteristics of the dynamic force of jet elements, a kind of simple pendulum test system was presented. The dynamic jet force value was obtained indirectly by the acceleration value of the jet element under its force. The mathematic model of the test system was established and the test errors of the amplitude and delay time were analyzed. A processing method of dynamic force test data was presented based on the test curve and the parameters of amplitude and delay time were obtained. The result indicates that the test method can satisfy the testing requirements of dynamic force and it has advantages of simple structure, low demands of testing condition and simple method of data processing.

The Improved Friction Properties of Bonded MoS2 Films by MAO Treating of Al Substrate

2013 ◽  
Vol 275-277 ◽  
pp. 1911-1914 ◽  
Author(s):  
Han Jun Hu ◽  
Hui Zhou ◽  
Yu Gang Zheng ◽  
Kai Feng Zhang ◽  
Zhi Hua Wan
Keyword(s):  
Tribological Properties ◽  
Solid Lubricants ◽  
Ceramic Coatings ◽  
Test System ◽  
Test Method ◽  
Test Results ◽  
Specimen Test ◽  
Micro Arc Oxidation ◽  
A New Technique ◽  
Porous Microstructures

The bonded MoS2 films are widely used as solid lubricants in aerospace mechanisms due to their excellent tribological properties. Traditionally, the MoS2 was directly bonded on the Al substrate that was only treated by the technique named of sandblast. For improving the tribological properties of MoS2 films, micro arc oxidation (MAO) instead of sandblast was introduced as a new technique for treating of Al substrate. In this article, the tribological properties of MoS2 films which were bonded on different surface of Al substrate as mentioned above were discussed, respectively. It was concluded from the test results that the MoS2 films bonded on substrate treated by MAO have better tribological properties than those samples treated by sandblast. The endurance life against abrasion of the former is as high as twenty times of the latter by the stand test method of ball on disk using the UMT Multi-Specimen Test System. This test results could be illustrated by the following reasons. The first is the porous microstructures of MAO ceramic coatings on the Al substrate. The coatings have numerous pits to be good at increasing the binding force with the MoS2 films, and the pits can also provide a MoS2 lubricants reservoir during processes of friction. Both of them improved the MoS2 film’s ability of wear-protective. The second is that hardness of the coating is higher than the Al, and this ensures well wearing resistance, especially in practical application to big load-supporting moving parts, such as bearing, gear, etc…

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