New working radium-226 mass-unit standard

Purpose The original Connected Speech Test (CST; Cox et al., 1987) is a well-regarded and often utilized speech perception test. The aim of this study was to develop a new version of the CST using a neutral North American accent and to assess the use of this updated CST on participants with normal hearing. Method A female English speaker was recruited to read the original CST passages, which were recorded as the new CST stimuli. A study was designed to assess the newly recorded CST passages' equivalence and conduct normalization. The study included 19 Western University students (11 females and eight males) with normal hearing and with English as a first language. Results Raw scores for the 48 tested passages were converted to rationalized arcsine units, and average passage scores more than 1 rationalized arcsine unit standard deviation from the mean were excluded. The internal reliability of the 32 remaining passages was assessed, and the two-way random effects intraclass correlation was .944. Conclusion The aim of our study was to create new CST stimuli with a more general North American accent in order to minimize accent effects on the speech perception scores. The study resulted in 32 passages of equivalent difficulty for listeners with normal hearing.

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Atomic mass unit

AccessScience ◽

10.1036/1097-8542.060400 ◽

2015 ◽

Keyword(s):

Atomic Mass ◽

Atomic Mass Unit ◽

Mass Unit

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Effect of aluminum content on structure, transport and mechanical properties of Sn-Zn eutectic lead free solder alloy rapidly solidified from melt.

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v10i1.1343 ◽

2015 ◽

Vol 10 (1) ◽

pp. 2641-2648

Author(s):

Rizk Mostafa Shalaby ◽

Mohamed Munther ◽

Abu-Bakr Al-Bidawi ◽

Mustafa Kamal

Keyword(s):

Mechanical Properties ◽

Melting Point ◽

Lead Free ◽

Al Alloy ◽

Lead Free Solder ◽

Pronounced Increase ◽

Mass Unit ◽

Size Refinement ◽

Free Solder ◽

Lead Free Solders

The greatest advantage of Sn-Zn eutectic is its low melting point (198 oC) which is close to the melting point. of Sn-Pb eutectic solder (183 oC), as well as its low price per mass unit compared with Sn-Ag and Sn-Ag-Cu solders. In this paper, the effect of 0.0, 1.0, 2.0, 3.0, 4.0, and 5.0 wt. % Al as ternary additions on melting temperature, microstructure, microhardness and mechanical properties of the Sn-9Zn lead-free solders were investigated. It is shown that the alloying additions of Al at 4 wt. % to the Sn-Zn binary system lead to lower of the melting point to 195.72 ËšC.Â From x-ray diffraction analysis, an aluminium phase, designated Î±-Al is detected for 4 and 5 wt. % Al compositions. The formation of an aluminium phase causes a pronounced increase in the electrical resistivity and microhardness. The ternary Sn-9Zn-2 wt.%Al exhibits micro hardness superior to Sn-9Zn binary alloy. The better Vickers hardness and melting points of the ternary alloy is attributed to solid solution effect, grain size refinement and precipitation of Al and Zn in the Sn matrix.Â The Sn-9%Zn-4%Al alloy is a lead-free solder designed for possible drop-in replacement of Pb-Sn solders.Â Â

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Extraction of Antioxidant Compounds from Blueberry Fruit Waste and Evaluation of Their In Vitro Biological Activity in Human Keratinocytes (HaCaT)

Food Analytical Methods ◽

10.1007/s12161-021-02056-7 ◽

2021 ◽

Author(s):

Tomasz Piechowiak ◽

Bartosz Skóra ◽

Katarzyna Grzelak-Błaszczyk ◽

Michał Sójka

Keyword(s):

Antioxidant Activity ◽

Antioxidant Properties ◽

Waste Material ◽

Lower Amount ◽

Process Time ◽

Antioxidant Compounds ◽

Mass Unit ◽

Diet Supplements ◽

Study Results

AbstractThe purpose of this study was to investigate the biological properties of an extract obtained from the waste of blueberry fruit. The study covered the optimization of extraction of antioxidants from blueberry pomace and the determination of antioxidant properties of the extract using HaCaT as the model organism. Research showed that the yield of antioxidants extraction from blueberry waste was dependent on the applied extraction conditions. Based on the mathematical models, the optimal conditions of extraction process in which the maximum quantity of antioxidant compounds is achieved from the waste mass unit, i.e., the relation of the waste mass to the volume of ethanol equal to 1:17.36, and process time equal to 1000 s. The obtained extract was characterized by high antioxidant activity, which was shaped by high content of polyphenols, mainly anthocyanins. Moreover, the extract showed a high ability to protect HaCaT cells from the occurrence of oxidative stress induced by H2O2. Cells treated with the extract and H2O2 generated a lower amount of ROS than cells treated with H2O2 only. The obtained results will be base of further studies on applying the extract in production of diet supplements and functional foods with increased antioxidant activity. Moreover, the main research material is blueberry pomace which is a troublesome waste material for juice producers. Consequently, according to a sustainable development idea, the study results will provide an opportunity to increase interest in the problem of rational use of the waste material to a certain extent.

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Untersuchung von Calciumisotopieeffekten bei heterogenen Austauschgleichgewichten / Investigation of Isotopic Effects of Calcium in Heterogeneous Exchange Equilibria

Zeitschrift für Naturforschung B ◽

10.1515/znb-1972-0204 ◽

1972 ◽

Vol 27 (2) ◽

pp. 126-133 ◽

Cited By ~ 33

Author(s):

Klaus Gustav Heumann ◽

Karl Heinrich Lieser

Keyword(s):

Separation Factor ◽

Calcium Concentration ◽

Isotopic Fractionation ◽

Ion Source ◽

Isotopic Effect ◽

Mass Unit ◽

Calcium Isotopes ◽

Heterogeneous Exchange ◽

Loaded Column ◽

Isotopic Effects

The following heterogeneous exchange equilibria have been examined for isotopic effects: CaCO3/Ca(aq.)2⊕. Ca-GBHA/Ca(aq.)2⊕ and Ca(Dowex 50)2⊕/Ca(aq.)2⊕ (GBHA = glyoxal-bis (2-hydroxyanil)). The isotopic ratios 44Ca/40Ca and 48Ca/40Ca were determined by means of a mass spectrometer with a thermal ion source. In the system CaCO3/Ca(aq.)2⊕, the elementary separation factor was found to be less than 1‰ or 0,5‰ per mass unit, respectively.For the exchange in the system Ca-GBHA/Ca(aq.)2⊕ in the concentration range from 0.011 to 0.84 M an elementary separation factor less than 1‰ per mass unit was found; from a three-stage experiment at a calcium concentration of 1.23 M it was concluded that the elementary isotopic effect is less than 0.4‰ per mass unit. Therefore no isotopic fractionation is to be expected for precipitation of inorganic or organic calcium salts.An enrichment of the heavier calcium isotopes in the solution was found in the case of the exchange in a Dowex 50-X12 loaded column. The isotopic effect depends on the concentration of the hydrochloric acid used as the eluent.

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