Atomization characteristics of intermittent multi-hole diesel spray using time-resolved PDPA data

The intermittent spray characteristics of a multi-hole diesel nozzle with a 2-spring nozzle holder were investigated experimentally. Without changing the total orifice exit area, the hole number of the multi-hole nozzle varied from 3 (d_n=0.42 mm) to 5 (d_n=0.32mm). The time-resolved droplet diameters of the spray including the SMD (Sauter mean diameter) and the AMD (arithmetic mean diameter), injected intermittently from the multi-hole nozzles into still ambient air, were measured by using a 2-D PDPA (phase Doppler particle analyzer). The 5-hole nozzle spray shows the smaller spray cone angle, the decreased SMD distributions and the small difference between the SMD and the AMD, compared with that of the 3-hole nozzle spray. From the SMD distributions with the radial distance, the spray structure can be classified into the three regions : (a) the inner region showing the high SMD distribution; (b) the mixing flow region where the shear flow structure would be constructed; and (c) the outer region formed through the disintegration processes of the spray inner region and composed of fine droplets. Through the SMD distributions along the spray centerline, it reveals that the SMD decreases rapidly after showing the maximum value in the vicinity of the nozzle tip. The SMD remains the constant value near the Z/d_n=166 and 156.3 for the 3-hole and 5-hole nozzles, which illustrate that the disintegration processes of the 5-hole nozzle spray proceed more rapidly than that of the 3-hole nozzle spray.     

Thermo-siphon mock-up test for the cold neutron source of HANARO

Due to the national demand for a cold neutron beam utilization, a cold neutron research facility project has been carried out since July 2003 to install a cold neutron source (CNS) in HANARO. The CNS adopts a two-phase thermo-siphon of liquid hydrogen as a working fluid to remove a heat load. The CNS consists of an in-pool assembly (IPA) and other components including a hydrogen buffer tank. The liquid level in the moderator cell is measured by a gamma-ray densitometer under a normal cold operation, and the cool down time to fill the required liquid hydrogen into the moderator cell is numerically simulated and compared with the experimental data from a thermo-siphon mock-up test. The self-regulating characteristic of the two-phase thermo-siphon loop is also confirmed by a comparison of a model simulation’s results, which use a thermodynamic model, with the experiment’s results. From these results, the HANARO-CNS is found to maintain the required conditions for a stable cold neutron production against a heat load variation along with the reactor’s power. Furthermore, the thermodynamic behavior in the IPA is observed to determine whether or not the integrity of the IPA is maintained under an abnormal condition of the helium refrigeration system.     

Monitoring of microbial hazards at farms, slaughterhouses, and processing lines of swine in Korea

This study was executed to investigate microbiological hazards at swine farms, slaughterhouses, dressing operations, and local markets for the application of the hazard analysis critical control point system in Korea by analyzing total aerobic plate count (APC) and presence of pathogens. Six integrated pig farms and meat packers were selected from six different provinces, and samples were collected from pig carcasses by swabbing and excision methods at the slaughterhouses, processing rooms, and local markets, respectively. APCs of water in water tanks were relatively low, 1.9 to 3.1 log10 CFU/ml; however, they were increased to 4.6 to 6.9 log10 CFU/ml when sampled from water nipples in the pigpen. APCs of feeds in the feed bins and in the pigpens were 4.4 to 5.4 and 5.2 to 6.7 log10 CFU/g, respectively. Salmonella spp., Staphylococcus aureus, and Clostridium perfringens were detected from water and feed sampled in pigpens and pigpen floors. S. aureus was the most frequently detected pathogenic bacteria in slaughterhouses and processing rooms. Listeria monocytogenes and Yersinia enterocolitica were also detected from the processing rooms of the Kyonggi, Kyongsang, and Cheju provinces. Even though APCs were maintained at the low level of 3.0 log10 CFU/g during slaughtering and processing steps, those of final pork products produced by the same companies showed relatively high numbers when purchased from the local market. These results indicated that the cold chain system for transporting and merchandising of pork products was deficient in Korea. Water supply and feed bins in swine farms and individual operations can be identified as critical control points to reduce microbiological hazards in swine farms, slaughterhouses, and processing plants.     

Azuki bean (Vigna angularis) extract inhibits the development of experimentally induced atopic dermatitis-like skin lesions in NC/Nga mice

The present study investigated the effects of azuki bean (Vigna angularis) extract (VAE) on the progress of atopic dermatitis (AD)-like skin lesions in NC/Nga mice induced by 1-chloro-2,4-dinitrobenzene. The efficacy of VAE in NC/Nga mice was determined by measuring gross and histological skin lesions, serum IgE levels, eosinophil ratio in peripheral leucocytes, and mRNA expression levels of interleukin (IL)-4, tumour necrosis factor (TNF)-α and interferon (IFN)-γ in splenocytes. Continuous ingestion of VAE inhibited the development of the AD-like skin lesions in a dose-dependent manner. In the VAE-treated mice, the numbers of mast cells in the skin, eosinophil ratio in peripheral leucocytes, relative mRNA expression of inflammatory cytokines in the spleen, and serum IgE levels were significantly reduced. Results suggest that VAE can inhibit the development of AD-like skin lesions in NC/Nga mice by regulating immune mediators and cells, and may be an effective alternative therapy for AD.     

Phenolic compounds isolated from Zingiber officinale roots inhibit cell adhesion

Inhibitors of cell adhesion molecule-mediated cell adhesion might be novel therapeutic agents for the treatment of various inflammatory diseases. In this study, nine phenolic compounds were isolated from the methanol extracts of Zingiber officinale roots by bioactivity-guided fractionation. The structures of the compounds were determined by spectroscopic analysis (¹H, ¹³C NMR and MS), to be 6-gingerol (1), 8-gingerol (2), 10-gingerol (3), 6-shogaol (4), 8-shogaol (5), 10-shogaol (6), dehydro-6-gingerdione (7), dehydro-10-gingerdione (8) and 6-paradol (9). Compounds 3, 4, 5 and 7 inhibited direct binding between sICAM-1 and LFA-1 of the THP-1 cells in a dose-dependent manner with IC₅₀ values of 57.6, 27.1, 65.4 and 62.0 μM, respectively. Compounds 4 and 7 had an inhibitory effect on direct binding between sVCAM-1 and VLA-4 of THP-1 cells. These results suggest that the phenolic compounds from Z. officinale roots are good candidates for therapeutic strategies aimed at inflammation.     

Cryptanalysis of block-wise stream ciphers suitable for the protection of multimedia and ubiquitous systems

In this paper we introduce a general framework of related-key attack on block-wise stream ciphers which are suitable for the protection of multimedia and ubiquitous systems. As a case study, we show how our cryptanalytic framework is applied to a block-wise stream cipher TWOPRIME: we construct various related-key differentials of TWOPRIME and use them to show that recovering related keys of TWOPRIME can be performed with a data complexity of 2¹⁴ known plaintext blocks and a time complexity of 2³² 8-bit table lookups. We expect that our general framework for a related-key attack would be useful tool for analyzing many of block-wise stream ciphers.     

A study of the dynamic characteristics of synchronously controlled hydrodynamic journal bearings

In this paper, synchronous control of bearing is employed through a control algorithm for an actively controlled hydrodynamic journal bearing in order to suppress whirl instability and to reduce the unbalance response of a rotor-bearing system. Furthermore, a cavitation algorithm, implementing the Jakobsson–Floberg–Olsson boundary condition, is adopted to predict cavitation regions in a fluid film more accurately than the conventional analysis, which uses the Reynolds condition. The unbalance responses and stability characteristics of the rotor-bearing system are investigated for various control gains and phase differences between the bearing and journal motion. It is shown that the unbalance responses of the system can be greatly decreased by synchronous control of the bearing. There is an optimum phase difference, which gives the minimum unbalance response of the system at given operating conditions. It is also found that the stability threshold of the system can be greatly increased by synchronous control of the journal bearing.     

A review on automated diagnosis of malaria parasite in microscopic blood smears images

Multimedia Tools and Applications - Malaria is a life-threatening disease caused by parasite of genus plasmodium, which is transmitted through the bite of infected Anopheles. A rapid and accurate...