Development and Applications of VSV Vectors Based on Cell Tropism

Viral vectors have been available in various fields such as medical and biological research or gene therapy applications. Targeting vectors pseudotyped with distinct viral envelope proteins that influence cell tropism and transfection efficiency are useful tools not only for examining entry mechanisms or cell tropisms but also for vaccine vector development. Vesicular stomatitis virus (VSV) is an excellent candidate for development as a pseudotype vector. A recombinant VSV lacking its own envelope (G) gene has been used to produce a pseudotype or recombinant VSV possessing the envelope proteins of heterologous viruses. These viruses possess a reporter gene instead of a VSV G gene in their genome, and therefore it is easy to evaluate their infectivity in the study of viral entry, including identification of viral receptors. Furthermore, advantage can be taken of a property of the pseudotype VSV, which is competence for single-round infection, in handling many different viruses that are either difficult to amplify in cultured cells or animals or that require specialized containment facilities. Here we describe procedures for producing pseudotype or recombinant VSVs and a few of the more prominent examples from envelope viruses, such as hepatitis C virus, Japanese encephalitis virus, baculovirus, and hemorrhagic fever viruses

Theoretical Analysis of Rigid-Body Vibration in Swing Compressors

This study aims to theoretically analyze the rigid-body vibration in swing compressors. Currently, low noise and vibration (NV) are qualities recognized as a desired value for an air conditioner by end users. Because the compressor is one of the main sources of NV in an air conditioner, low NV compressors are needed. Designing a low NV compressor requires the understanding of the physical phenomena occurring in a compressor that contribute to NV. In this study, we theoretically analyzed rigid-body vibration, which has been one of the main phenomena causing NV in a swing compressor. Main factors causing rigid-body vibration in the swing compressor were classified into three types of excitation forces. By formulating them in a Fourier series representation, the primary and secondary components in the frequency domain were calculated for each excitation force without any numerical calculation method, including FFT. Furthermore, by multiplying the mass and inertial tensor of the compressor to this, we calculated both the amplitude and phase of the rigid-body vibration generated by each excitation force. We then confirmed that the calculated vibration was consistent with the experimental results. The contribution of each excitation force to the radial and tangential vibrations of typical swing compressors was theoretically analyzed. The results of the analysis clearly indicated that vibration was effectively reduced by not only simply reducing the magnitudes of the excitation forces but also by balancing the excitation forces

Evaluation of Compressor Reliability for HFO Refrigerants

Responses to an international flamework on climate change, such as the Kigali Agreement in 2016, have been discussed in an industrial field. The phase down regulation of CFC and HCFC refrigerant has been discussed and performed under the Montreal Protocol for refrigerants from the viewpoint of ozone layer protection. From the viewpoint of preventing global warming, HFC reduction plans are currently being proposed by North America, Europe, India, etc. within the framework of the Protocol. A developing country where the phase-out of CFCs and HCFCs began in 2013, are growing trend to switch to HFC or HFO mixed refrigerants with lower GWP than R410A. A revision of the regulations related to HFC are also being promoted in each region. The GWP upper limit for each equipment application was set together with the HFC phase down in Europe which due to the F-gas regulations. R32, HFO refrigerants such as R1234yf and R1234ze, or a mixed refrigerant of HFC and HFO are proposed as candidates for low GWP refrigerants. The problem of R32 was the higher discharge gas temperature than R410A, but the problem could be solved by temperature control and suitable refrigeration oil. On the other hand, the problem of refrigerants HFO and mixed HFO is easy to decompose than HFC. When HFO is decompose, it is generated acid such as fluorinated acid and trifluoroacetic acid. These acids make which is reduced the compressor reliability. We selected of suitable refrigeration oil and materials for the HFO and confirmed the compressor reliabilit

Selection of a refrigeration oil for the R32 refrigerant and evaluation of the compressor reliability

Recently, low global warming potential (GWP) refrigerants have attracted attention as an alternative to the most commonly used refrigerants. We considered R32 as an alternative to the R410A because of its low GWP and energy saving characteristics. This study focused on the selection of a suitable refrigeration oil for the R32 that would not compromise compressor reliability. We found R32 to be poorly miscible with refrigeration oils used for the R410A. This, combined with higher discharge gas temperature for R32 compared to R410A, would result in lower compressor reliability. We selected a refrigeration oil suitable for the R32 and confirmed compressor reliability equivalent to the R410A

Development of High Efficiency Swing Compressor for R32 Refrigerant

In the age of global warming, energy saving features and overall reduction of environmental impact are critical components that must be addressed when developing new HVAC units. We chose the R32 refrigerant, with its lower LCCP as a more sustainable choice than the R410A. However, R32 has its drawbacks. Due to its smaller molecular weight, internal leakage loss is higher for the R32. Moreover, high discharge gas temperature decrease the reliability of the compressor, and make a large overheating loss increase. In this study, we will describe the technologies that were developed to overcome these drawbacks. We will also present the performance and reliability of the newly developed high efficiency swing compressor series for R32 refrigerants

Vertical-Vibration Suppressing Design of Accumulator with New Vibration-Measuring Method

A compressor was developed using R32 which was a low GWP R32 refrigerant for coping with global warming. However, there is a tendency for vibrations of a compressor to also increase because the circulation of refrigerant increases according to specification for using R32 refrigerant. Since large vibrations of a compressor causes outdoor units to generate solid propagation sound, there is a need for a technology that can reduce vibration of a compressor. However, a vibration-measuring method to analyze such vibration had not been fully developed and it was difficult to specify the cause. Accordingly, a new vibration-measuring method was developed specifically for compressors. The use of this measuring method allowed to discover that one of the unresolved problems with sound of outdoor units was the vertical vibration of the accumulator housed in the compressor. Moreover, it was found that the accumulator vibrates vertically due to the acoustic resonance inside the casing, which led to develop a new (accumulator) design with a focus on resonance. There is a type of spatial resonance inside an accumulator that has a phase difference with the antinode of sound pressure appearing at the upper and lower ends of the space. The vertical force caused by the difference in the sound pressure becomes excitation force, which then causes vertical vibration of the accumulator. Therefore, preventing this resonance from occurring can help suppress the vertical vibration. In order to prevent the generation of resonance, a plate-shaped reflection member was placed inside the accumulator, and it proved to be effective in suppressing the vertical vibration

Live E! Project: Establishment of Infrastructure Sharing Environmental Information

The Live E! project is an open research consortium among industry and academia to explore the platform to share the digital information related with the earth and our living environment. We have getting a lot of low cost sensor nodes with Internet connectivity. The deployment of broad-band and ubiquitous networks will enable autonomous and global digital information sharing over the globe. In this paper, we describe the technical and operational overview of Live E! project, while discussing the objective, such as education, disaster protection/reduction/recovery or busi-ness cases, and goal of this project activity. 1