The pressure-density-temperature-composition (---) data of binary refrigerant mixtures containing R-134a (1,1,1,2-tetrafluoroethane), R-1234yf (2,3,3,3-tetrafluoropropene), and R-1234ze(E) (-1,3,3,3-tetrafluoropropene) were measured in both the vapor and liquid phases using a two-sinker, magnetic-suspension densimeter. The specific samples in this study comprised two compositions of approximately (0.3/0.7) and (0.7/0.3) mole fraction for each of the following three binary refrigerant blends: R-1234yf + R-134a, R-134a + R-1234ze(E), and R-1234yf + R-1234ze(E). Single-phase vapor densities were measured over a temperature range of (253 to 293) K and pressures from approximately (0.04 to 0.5) MPa. Single-phase liquid and supercritical densities were measured over a temperature range of (230 to 400) K and pressures up to 21 MPa; for refrigerant blends containing R-1234yf, the maximum pressure was limited to approximately 12 MPa. Overall relative combined, expanded ( = 2) uncertainties in density ranged from 0.043% to 0.418%, with an average uncertainty of approximately 0.06%. Here, we present measurement results, along with comparisons to available literature data and to default equations of state and mixture models included in REFPROP.
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http://dx.doi.org/10.1021/acs.jced.3c00103 | DOI Listing |
Int J Thermophys
January 2024
Applied Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, CO 80305, USA.
Sound speed data measured using a dual-path pulse-echo instrument are reported for pure -1,2-dichloroethene (R-1130(E)) and an azeotropic blend of -1,1,1,4,4,4-hexafluorobutene (R-1336mzz(Z)) and R-1130(E) with a composition of 74.8 mass % R-1336mzz(Z) with the balance being R-1130(E). The azeotropic blend of R-1336mzz(Z)/1130(E) is classified as R-514A in ANSI/ASHRAE standard 34.
View Article and Find Full Text PDFBMC Pediatr
November 2024
College of Health Science and Referral Hospital, Ambo University, Ambo, Oromia, Ethiopia.
Background: Cold chain management is a continuous and cohesive process of preserving vaccines to ensure their availability and potency. However, the quality control of vaccines has been neglected in resource-limited areas such as Ethiopia. Adequate levels of health workers' knowledge and practices in vaccine cold chain management are important to maintain the potency of vaccines and achieve the intended vaccine end goal.
View Article and Find Full Text PDFSci Rep
October 2024
Department of Pharmacy, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia.
Oxytocin is the principal drug and the primary choice for labor induction and postpartum hemorrhage prevention and treatment. The problems associated with oxytocin are not usually from its effectiveness, but they are from its compromised quality which may occur at the point of manufacturing, transportation, and storage. The main objective of this study was to assess the status of oxytocin injection quality and associated factors in the health facilities located in Addis Ababa city, Ethiopia.
View Article and Find Full Text PDFUltrason Sonochem
December 2024
Department of Food Science, College of Agriculture and Veterinary Medicine, United Arab Emirates University, Al-Ain 15551, UAE; National Water and Energy Center, United Arab Emirates University, Al-Ain 15551, UAE. Electronic address:
This study focuses on the extraction of bioactive compounds from date seeds using five polyol-based deep eutectic solvents (P-DESs) in combination with hybrid green extraction techniques, specifically microwave-assisted extraction (MAE), homogenization-assisted extraction (HAE), and ultrasound-assisted extraction (UAE). The optimization of these extraction techniques was achieved using P-DESs showing the highest efficiency for extracting date seed bioactive compounds using response surface methodology (RSM) and central composite design (CCD) approach. The optimized conditions from three green techniques were further applied in the form of hybrid green extraction techniques, involving six binary and three ternary methods, to assess the percentage increase in the extraction efficiency of date seed bioactive polyphenolics.
View Article and Find Full Text PDFJ Chem Phys
August 2024
Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA.
Hydrofluorocarbons are a class of fluorinated molecules used extensively in residential and industrial refrigeration systems. This study examines the potential of using adsorption processes with the silicalite-1 zeolite to separate a mixture of difluoromethane (CH2F2, HFC-32) and pentafluoroethane (CF3CF2H, HFC-125) at various concentrations. Pure adsorption data were measured using a XEMIS gravimetric microbalance, whereas binary data were determined using the Integral Mass Balance method.
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