Study on Flow Characteristics of Oil Viscosity Pump for Refrigerant Compressors

 Oil viscosity pumps are typically used for reciprocating compressors in household refrigerators to lubricate the compression mechanism. The oil viscosity pump is a simple structure in which a spiral groove is on the shaft surface. The lubricating oil supplied by this pump has a large influence on the performance and reliability, but the oil viscosity pump is designed based on the experience. We investigated the flow characteristics of the oil viscosity pump from theoretical and experimental study. We performed the study based on the assumption that the oil flow inside spiral groove was steady with two-dimensional viscous flow. As a result, we found that the pressure-flow rate (P-Q) characteristics has a linear relationship when the length of the spiral grooves, the rotational speed of the shaft, and the depth of the spiral grooves are in the limited area

Plasma S100A12 Levels and Peripheral Arterial Disease in End-Stage Renal Disease

Background: S100A12 is an endogenous ligand of the receptor for advanced glycation end products (RAGE). Plasma S100A12 levels are high in end-stage renal disease (ESRD) patients undergoing maintenance hemodialysis (HD). Peripheral arterial disease (PAD) is common in HD patients and is associated with increased cardiovascular morbidity and mortality rates in this population. To date, however, no study has specifically assessed the relationship between plasma S100A12 and PAD in HD patients. Methods: We conducted a cross-sectional study of 152 HD patients in our affiliated hospital. We investigated PAD history and patient characteristics and quantified plasma S100A12 levels in all participants. Results: HD patients with PAD (n = 26; 21.9 [13.6–33.4] ng/ml) showed significantly higher plasma S100A12 levels than HD patients without PAD (n = 126; 11.8 [7.5–17.6]ng/ml; p Conclusion: These results suggest that plasma S100A12 levels are strongly associated with PAD prevalence in ESRD patients undergoing HD

An ad-hoc routing protocol in hybrid wireless networks for emergency communications

This paper proposes an ad-hoc routing protocol using unicast-based route discovery in a hybrid wireless network, ECCA, which combines ad-hoc networking scheme with a centralized hierarchical network. The network aims to collect damage assessment information in disaster circumstances, maintaining connections between a base station (BS) and nodes by way of multihopping. In the event that a direct link between BS and a node disconnects, the node switches the mode from a cellular to an ad-hoc mode in order to access BS via neighboring nodes. A routing protocol proposed in this paper builds a route by way of monitoring neighbors ' communications instead of broadcasting a route request packet. Experiments show that approximately 90 % of nodes can discover a route within a few hops, even if only 20 % of nodes are able to access BS directly. Even in a low node density, the network is capable of transferring data within three hops. 1