395. Field Validation Using two Samples in Series as an Alternative to Parallel Sampling

1999 ◽  
Author(s):  
R. Ackerman
2019 ◽  
Vol 34 (s1) ◽  
pp. s42-s42
Author(s):  
Malinda Steenkamp ◽  
Kirstin Ross ◽  
Harriet Whiley ◽  
Emmanuel Chubaka ◽  
Paul Arbon

Introduction:Roof-harvested rainwater held in domestic tanks is used for a variety of purposes in Australia, including drinking and irrigation. There is limited evidence about the quality of rainwater after bushfires. Current health guidelines can be interpreted that landholders need to drain their rainwater tanks to avoid the risk of contamination. Anecdotal reports indicate that following such advice caused additional distress to landowners affected by bushfires in South Australia. Sustainable water management is important for future resilience and more evidence on water quality following bushfires is needed.Aim:This project investigated whether there is contamination of roof-harvested rainwater after bushfires, and if so, whether such water was safe for various purposes.Methods:In 2017 we tested artificially contaminated water spiked with chemicals associated with bushfires (chromated copper arsenate-treated ash and firefighting foam) and conducted a pilot field study using two purposely built roofs during a pre-fire season burn off. A field validation is planned for the summer of 2018/19 (December 2018 - March 2019), i.e., we plan to obtain 200 samples from 50 households affected by bushfire – two samples immediately after the fire event and another two after the first rain.Results:The artificially created contaminated water fell within guidelines for non-potable uses such as irrigation and stock watering, but was found unsuitable for drinking even after being filtered through two commercially available water filtration systems. We also plan to present results from our field study of 50 households.Discussion:Contaminant concentrations, even in artificially spiked water samples, are low and acceptable for non-potable uses. Bottled water should be used for drinking. Landholders should be encouraged to use their water for recovery purposes. Such advice may assist with decreasing the stress experienced by affected landholders and help with recovery efforts through the availability of a greater body of water.


2015 ◽  
Vol 58 (1) ◽  
pp. 48-55
Author(s):  
Dan Malaescu ◽  
Ioan Grozescu ◽  
Paula Sfirloaga ◽  
Paulina Vlazan ◽  
Catalin N. Marin

Abstract Two samples of NaTaO3 perovskite materials were prepared by the standard hydrothermal method at the same reaction temperature (600 °C) but with different sintering times: 6 hours for sample S1 and 12 hours for sample S2.Using X-ray diffraction (XRD), it shows that samples S1 and S2 are mixtures of Na-Ta oxides (Ta2O5 and the prevailing phase NaTaO3). The scanning electron microscopy analysis (SEM), shows that the grains are connected each other in agglomerated clusters of size about few hundred nanometers.The frequency (f) dependencies of complex impedance, Z(f) = Z’(f) - i Z’’(f) of the samples, over the frequency range 20 Hz - 2 MHz, at room temperature are presented. The real component Z’ of the complex impedance decreases with increasing frequency and the imaginary component Z’’ has two maximum corresponding to two relaxation processes.The results obtained from the complex impedance spectroscopy, Z’’(Z’) showed the appearance of two semicircles, corresponding to grain and grain boundary mechanism. Experimental results have been fitted with two parallel RC equivalent circuits connected in series and the parameters R and C have been evaluated.


1988 ◽  
Vol 71 (3) ◽  
pp. 515-518
Author(s):  
Ugo R Cieri

Abstract A procedure is presented for the determination of reserpine and hydrochlorothiazide in commercial tablets by liquid chromatography (LC). Reference and sample solutions are prepared in methanol. For LC, a normal phase column is used, methanol is the eluting solvent, and 2 detectors are arranged in series. A fluorescence detector set at an excitation wavelength of 280 nm and emission wavelength of 360 nm quantitates reserpine, and a UV absorption detector set at 345 nm determines hydrochlorothiazide. Several synthetic mixtures containing the 2 ingredients in the amounts approximately present in commercial tablets were analyzed by the proposed method. Two samples of commercial tablets were also analyzed; for each sample, 5 determinations were made on a ground composite of 20 tablets; 10 individual tablets were also analyzed. For comparison, some of the solutions were analyzed for each ingredient by an alternative procedure.


2002 ◽  
Vol 753 ◽  
Author(s):  
C. A. Jenkins ◽  
R. C. O'Handley ◽  
S. M. Allen

ABSTRACTSingle crystals of nickel-manganese-gallium, a ferromagnetic shape memory alloy (FSMA), show up to 10% elongation in response to an applied magnetic field or mechanical stress. The change in dimension is not a result of magnetostriction but of twin boundary motion through the material. The field-induced extension has previously been reversed only by a compressive mechanical stress from a spring or orthogonal field. The use of a second crystal of Ni-Mn-Ga to provide the reset force is unreported.Data are shown here of the stress and strain behavior of two FSMA crystals connected in series and subjected alternately to a magnetic field. Two samples, one initially in full extension and the other in compression, are arranged in series in a rigid frame such that their total length is held constant. A pulsed magnetic field is alternately applied to the samples, with the output energy of the extending crystal tending to apply a resetting force to the other. This setup shows up to 1.5% resetting strain in single crystal laminates.


1995 ◽  
Vol 78 (6) ◽  
pp. 1384-1387 ◽  
Author(s):  
Ugo R Cieri

Abstract A procedure is presented for determination of reserpine and chlorothiazide in commercial tablets by liquid chromatography (LC). Powdered sample, equivalent to the weight of one tablet, is dissolved in 10.0 mL dimethyl sulfoxide, the mixture is diluted to 100.0 mL with methanol, and the solution is filtered; 10 mL of the filtrate is then diluted to 100.0 mL with methanol. The standard solution is prepared in the same solvent mixture and contains the 2 ingredients in approximately the same quantities as in the diluted sample solution. For LC, a 7.5 cm long normal-phase column is used; mobile phase consists of methanol containing a small volume of an aqueous solution of 1-pentanesulfonic acid, sodium salt. Two detectors are arranged in series: a fluorescence detector set at 280 nm excitation and 360 nm emission quantitates reserpine and a UV absorbance detector set at 300 nm determines chlorothiazide. Several synthetic mixtures containing the 2 ingredients in amounts ranging from 80 to 120% of quantities declared in commercial tablets were analyzed by the proposed method. Two samples of commercial tablets were also analyzed; for each sample, 5 determinations were made on a ground composite of 20 tablets; 10 individual tablets were also analyzed. The composites were also analyzed by the current U.S. Pharmacopeia method for this product.


Author(s):  
D W McComb ◽  
R S Payne ◽  
P L Hansen ◽  
R Brydson

Electron energy-loss near-edge structure (ELNES) is an effective probe of the local geometrical and electronic environment around particular atomic species in the solid state. Energy-loss spectra from several silicate minerals were mostly acquired using a VG HB501 STEM fitted with a parallel detector. Typically a collection angle of ≈8mrad was used, and an energy resolution of ≈0.5eV was achieved.Other authors have indicated that the ELNES of the Si L2,3-edge in α-quartz is dominated by the local environment of the silicon atom i.e. the SiO4 tetrahedron. On this basis, and from results on other minerals, the concept of a coordination fingerprint for certain atoms in minerals has been proposed. The concept is useful in some cases, illustrated here using results from a study of the Al2SiO5 polymorphs (Fig.l). The Al L2,3-edge of kyanite, which contains only 6-coordinate Al, is easily distinguished from andalusite (5- & 6-coordinate Al) and sillimanite (4- & 6-coordinate Al). At the Al K-edge even the latter two samples exhibit differences; with careful processing, the fingerprint for 4-, 5- and 6-coordinate aluminium may be obtained.


2020 ◽  
Vol 63 (9) ◽  
pp. 2921-2929
Author(s):  
Alan H. Shikani ◽  
Elamin M. Elamin ◽  
Andrew C. Miller

Purpose Tracheostomy patients face many adversities including loss of phonation and essential airway functions including air filtering, warming, and humidification. Heat and moisture exchangers (HMEs) facilitate humidification and filtering of inspired air. The Shikani HME (S-HME) is a novel turbulent airflow HME that may be used in-line with the Shikani Speaking Valve (SSV), allowing for uniquely preserved phonation during humidification. The aims of this study were to (a) compare the airflow resistance ( R airflow ) and humidification efficiency of the S-HME and the Mallinckrodt Tracheolife II tracheostomy HME (M-HME) when dry (time zero) and wet (after 24 hr) and (b) determine if in-line application of the S-HME with a tracheostomy speaking valve significantly increases R airflow over a tracheostomy speaking valve alone (whether SSV or Passy Muir Valve [PMV]). Method A prospective observational ex vivo study was conducted using a pneumotachometer lung simulation unit to measure airflow ( Q ) amplitude and R airflow , as indicated by a pressure drop ( P Drop ) across the device (S-HME, M-HME, SSV + S-HME, and PMV). Additionally, P Drop was studied for the S-HME and M-HME when dry at time zero (T 0 ) and after 24 hr of moisture testing (T 24 ) at Q of 0.5, 1, and 1.5 L/s. Results R airflow was significantly less for the S-HME than M-HME (T 0 and T 24 ). R airflow of the SSV + S-HME in series did not significant increase R airflow over the SSV or PMV alone. Moisture loss efficiency trended toward greater efficiency for the S-HME; however, the difference was not statistically significant. Conclusions The turbulent flow S-HME provides heat and moisture exchange with similar or greater efficacy than the widely used laminar airflow M-HME, but with significantly lower resistance. The S-HME also allows the innovative advantage of in-line use with the SSV, hence allowing concurrent humidification and phonation during application, without having to manipulate either device.


2001 ◽  
Vol 60 (1) ◽  
pp. 11-14 ◽  
Author(s):  
Lucia Savadori ◽  
Eraldo Nicotra ◽  
Rino Rumiati ◽  
Roberto Tamborini

The content and structure of mental representation of economic crises were studied and the flexibility of the structure in different social contexts was tested. Italian and Swiss samples (Total N = 98) were compared with respect to their judgments as to how a series of concrete examples of events representing abstract indicators were relevant symptoms of economic crisis. Mental representations were derived using a cluster procedure. Results showed that the relevance of the indicators varied as a function of national context. The growth of unemployment was judged to be by far the most important symptom of an economic crisis but the Swiss sample judged bankruptcies as more symptomatic than Italians who considered inflation, raw material prices and external accounts to be more relevant. A different clustering structure was found for the two samples: the locations of unemployment and gross domestic production indicators were the main differences in representations.


2004 ◽  
Vol 63 (2) ◽  
pp. 107-111 ◽  
Author(s):  
Marianne Schmid Mast

The goal of the present study was to provide empirical evidence for the existence of an implicit hierarchy gender stereotype indicating that men are more readily associated with hierarchies and women are more readily associated with egalitarian structures. To measure the implicit hierarchy gender stereotype, the Implicit Association Test (IAT, Greenwald et al., 1998) was used. Two samples of undergraduates (Sample 1: 41 females, 22 males; Sample 2: 35 females, 37 males) completed a newly developed paper-based hierarchy-gender IAT. Results showed that there was an implicit hierarchy gender stereotype: the association between male and hierarchical and between female and egalitarian was stronger than the association between female and hierarchical and between male and egalitarian. Additionally, men had a more pronounced implicit hierarchy gender stereotype than women.


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