Condensation and Evaporation of R134a, R1234ze(E) and R1234ze(Z) Flow in Horizontal Microfin Tubes at Higher Temperature

Hydrofluoro-olefin R1234ze(E) and the isomer R1234ze(Z) are anticipated to be environment-friendly alternatives of R134a. Especially, R1234ze(Z) is most likely to be suitable for high-temperature heat pumps in industries. The heat transfer characteristics of those refrigerants R134a, R1234ze(E) and R1234ze(Z) are experimentally compared in this study. Their heat transfer coefficient and pressure gradient in a horizontal microfin tube are measured at temperatures of 40 and 50 oC for condensation, and temperature of 30 oC for evaporation. The equivalent inner diameter, fin height, and surface enlargement to the equivalent smooth tube of the microfin tube are 5.34 mm, 0.255 mm, and 2.24, respectively. The thermodynamic and transport properties of R1234ze(Z) are calculated by Reprop (Lemmon et al., 2013) associated the fluid file provided by Akasaka (2013) that is proposed to fit the experimental data by Higashi et al. (2013) and Miyara et al. (2013). For condensation, the heat transfer coefficient and pressure gradient of R1234ze(Z) are higher than those of R1234ze(E) and R134a at mass flux of 200 kg m-2s-1 and heat flux of 10 kW m-2. This is mainly because of the higher vapor velocity due to lower vapor density, larger liquid thermal conductivity and latent heat comparing to R134a and R1234ze(E). The experimentally determined heat transfer coefficient and pressure gradient are reasonably agree with the predicted values by Cavallini et al. (2009), Yonemoto et al. (2006), and Kadzierski et al. (1998). For evaporation, at mass flux of 200 kg m-2s-1 and heat flux of 10 kW m-2, the heat transfer coefficient of R1234ze(Z) is somewhat higher than that of R134a and R1234ze(E) at only higher vapor qualities. The pressure gradient of R1234ze(Z) is notably higher than that of R134a and R1234ze(E). The experimental heat transfer coefficient and pressure gradient are agree well with predicted values by Chamra et al. (2007), Mori et al. (2002), Thome et al. (1997)

Condensation and Evaporation of R744/R32/R1234ze(E) Flow in Horizontal Microfin Tubes

R1234ze(E) has been anticipated to become an alternative of conventional refrigerant R410A for air conditioning systems. Latest studies revealed that the COP of R1234ze(E) alone is unexpectedly lower than that of R410A, mainly caused by irreversible loss in consequent of the small volumetric capacity. To increase volumetric capacity as maintaining the global warming potential (GWP) less than 300, adding R744 and R32 into R1234ze(E) has been attempted recently. For understanding the transport phenomenon of this ternary mixture, the heat transfer coefficient and pressure gradient of in a horizontal microfin tube is experimentally investigated in this study. Experimental data of R744/R32/R1234ze(E) (4/43/53 mass%) are compared to R32/R1234ze(E) (40/60 mass%) as the combination of GWP 300; data on R744/R32/R1234ze(E) (9/29/62 mass%) are compared to R32/R1234ze(E) (30/70 mass %) as the combination of GWP 200. At average saturation temperature of 40 oC, mass flux of 200 kg m-2s-1, and heat flux of 10 kWm-2, condensation heat transfer coefficient of R744/R32/R1234ze(E) (9/29/62 mass%) is somewhat lower than that of other mixtures R744/R32/R1234ze(E) (4/43/53 mass%), R32/R1234ze(E) (40/60 mass%) and (30/70 mass%). The temperature glide of R744/R32/R1234ze(E) (9/29/62 mass%), (4/43/53 mass%), R32/R1234ze(E) (30/70 mass%), and (40/60 mass%) is approximately 18, 11, 10, and 8 K, respectively, at 40 oC. Likewise, the magnitude of decrease in heat transfer coefficient is much related to the temperature glide during condensation. Similar effects of temperature glide is seen in data of evaporation heat transfer coefficient. At average saturation temperature of 10 oC, the evaporation heat transfer coefficient of R744/R32/R1234ze(E) (9/29/62 mass%) is slightly lower than that of other mixtures. The temperature glide of R744/R32/R1234ze(E) (9/29/62 mass%), (4/43/53 mass%), R32/R1234ze(E) (30/70 mass%), and (40/60 mass%) is approximately 22, 13, 11, and 9 K, respectively. The pressure gradient of those refrigerants are almost equal, and the difference is within measurement uncertainty. The experimental pressure gradient agrees well with prediction of Kubota et al. (2001), Filho et al. (2004), Newell and Shah (2001)

Single-shot single-mode optical two-parameter displacement estimation beyond classical limit

Uncertainty principle prohibits the precise measurement of both components of displacement parameters in phase space. We have theoretically shown that this limit can be beaten using single-photon states, in a single-shot and single-mode setting [F. Hanamura et al., Phys. Rev. A 104, 062601 (2021)]. In this paper, we validate this by experimentally beating the classical limit. In optics, this is the first experiment to estimate both parameters of displacement using non-Gaussian states. This result is related to many important applications, such as quantum error correction.Comment: 5 pages, 4 figure

Fundamental physics activities with pulsed neutron at J-PARC(BL05)

"Neutron Optics and Physics (NOP/ BL05)" at MLF in J-PARC is a beamline for studies of fundamental physics. The beamline is divided into three branches so that different experiments can be performed in parallel. These beam branches are being used to develop a variety of new projects. We are developing an experimental project to measure the neutron lifetime with total uncertainty of 1 s (0.1%). The neutron lifetime is an important parameter in elementary particle and astrophysics. Thus far, the neutron lifetime has been measured by several groups; however, different values are obtained from different measurement methods. This experiment is using a method with different sources of systematic uncertainty than measurements conducted to date. We are also developing a source of pulsed ultra-cold neutrons (UCNs) produced from a Doppler shifter are available at the unpolarized beam branch. We are developing a time focusing device for UCNs, a so called "rebuncher", which can increase UCN density from a pulsed UCN source. At the low divergence beam branch, an experiment to search an unknown intermediate force with nanometer range is performed by measuring the angular dependence of neutron scattering by noble gases. Finally the beamline is also used for the research and development of optical elements and detectors. For example, a position sensitive neutron detector that uses emulsion to achieve sub-micrometer resolution is currently under development. We have succeeded in detecting cold and ultra-cold neutrons using the emulsion detector.Comment: 9 pages, 5 figures, Proceedings of International Conference on Neutron Optics (NOP2017

Seawater Polluted with Highly Concentrated Polycyclic Aromatic Hydrocarbons Suppresses Osteoblastic Activity in the Scales of Goldfish, Carassius auratus

We have developed an original in vitro bioassay using teleost scale, that has osteoclasts, osteoblasts, and bone matrix as each marker: alkaline phosphatase (ALP) for osteoblasts and tartrate-resistant acid phosphatase (TRAP) for osteoclasts. Using this scale in vitro bioassay, we examined the effects of seawater polluted with highly concentrated polycyclic aromatic hydrocarbons (PAHs) and nitro-polycyclic aromatic hydrocarbons (NPAHs) on osteoblastic and osteoclastic activities in the present study. Polluted seawater was collected from two sites (the Alexandria site on the Mediterranean Sea and the Suez Canal site on the Red Sea). Total levels of PAHs in the seawater from the Alexandria and Suez Canal sites were 1364.59 and 992.56 ng/l, respectively. We were able to detect NPAHs in both seawater samples. Total levels of NPAHs were detected in the seawater of the Alexandria site (12.749 ng/l) and the Suez Canal site (3.914 ng/l). Each sample of polluted seawater was added to culture medium at dilution rates of 50, 100, and 500, and incubated with the goldfish scales for 6 hrs. Thereafter, ALP and TRAP activities were measured. ALP activity was significantly suppressed by both polluted seawater samples diluted at least 500 times, but TRAP activity did not change. In addition, mRNA expressions of osteoblastic markers (ALP, osteocalcin, and the receptor activator of the NF-κB ligand) decreased significantly, as did the ALP enzyme activity. In fact, ALP activity decreased on treatment with PAHs and NPAHs. We conclude that seawater polluted with highly concentrated PAHs and NPAHs influences bone metabolism in teleosts. © 2016 Zoological Society of Japan.Embargo Period 12 month