EFFECTS OF OPERATIONAL CONDITIONS ON DRYING CHARACTERISTICS IN CLOSED SUPERHEATED STEAM DRYING

The effects of operational conditions on the drying performance in closed superheated steam drying were examined theoretically and experimentally. The vapor generated from the sample was circulated in the drying chamber. In the theoretical analysis, the replacement of air with vapor in drying chamber and the convective vapor transfer in sample were considered. At the start of drying, the drying chamber was filled with air. As the drying proceeded, the air was replaced with the vapor generated from sample. The calculated results explained the characteristics of experimental data. The pore diameter of sample had little effect on the drying characteristics. During the internal evaporation period, the evaporation occurred in the narrow zone, which moved from the surface to the bottom of sample. The convective vapor transfer in sample had a significant influence on the drying performance. The excess increments in temperature and velocity of drying gas hardly contributed to shortening the drying time.     

SCR of NOx with NH3 over Cu/NaZSM-5 and Cu/HZSM-5 in the presence of decane

The selective catalytic reduction of NO_x with NH₃ in the presence of decane over Cu/ZSM-5 catalysts prepared from H⁺ and Na⁺ZSM-5 precursors were investigated. Cu/NaZSM-5 catalyst showed significantly higher NO_x conversion compared to Cu/HZSM-5. However, the presence of decane decreased the activity of both the catalysts, due to coke formation. Cu/HZSM-5 catalyst showed a larger decline in NO_x conversion with time on stream compared to Cu/NaZSM-5. The higher activity of Cu/NaZSM-5 is attributed, to the promoting effect of Na⁺ cations in the formation of active Cu⁺ and nitrite and nitrate intermediates species and retardation of coke formation.     

A case of AIDS with disseminated Mycobacterium kansasii infection in which Mycobacterium, avium complex was also detected from his sputum repeatedly

A 43 year-old Japanese male was admitted to our hospital because of productive cough and fever. He was diagnosed as acquired immunodeficiency syndrome (AIDS) in 1994. Laboratory findings were as follows: WBC was 3200/microliter, CD4+ T lymphocyte count was 22/microliter. His chest X-ray film taken on admission showed infiltration with small cavity lesion in middle left lung field. Tuberculin skin reaction was negative. He was treated with isoniazid 0.4 g, rifampicin 0.45 g, and ethambutol 0.75 g each daily. Sputum smear was positive for acid fast bacilli. The cultured isolates were identified as Mycobacterium kansasii (M. kansasii) and Mycobacterium avium complex (MAC). Urine smear was also positive for acid fast bacilli. The cultured isolates were identified as M. kansasii. He was diagnosed as disseminated M. kansasii infection and suspected MAC infection. About one hundred days later, his chest X-ray film showed reticular shadow. His clinical symptoms improved and the sputum smear and culture converted to negative for acid fast bacilli. Based on these findings, his MAC discharge was considered not as MAC infection, but MAC colonization. He returned to the former hospital for AIDS treatment, and he died in August 1996.     

A neck‐in model in extrusion lamination process

In this study, the experiment of the extrusion lamination process using high‐pressure process low‐density polyethylene (LDPE) was performed. The nonisothermal viscoelastic simulation of the extrusion lamination experiment was also carried out. The simulation results were in good agreement with the experimental data within wide range of take up velocity and air gap length. We developed the theoretical model based on force balance and deformation type of a film to predict the neck‐in behavior in the extrusion lamination or cast film process. It was suggested from the neck‐in model that the neck‐in correlates with the ratio of planar to uniaxial elongational viscosity. It was confirmed that the neck‐in model could predict the film edge shape and neck‐in properly for conventional LDPE. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

Purification and some properties of cholesterol oxidase stable in detergents from gamma-proteobacterium Y-134

Cholesterol oxidase (CHO) with high stability in detergents was found from an isolated strain, Y-134, belonging to the gamma-subclass of Proteobacteria. CHO production reached its maximum by incubation at 30 degrees C for 12 d. It was purified from cell-free extract prepared by mixing the cells with 0.4% Triton X-100. The absorption spectrum of the purified enzyme exhibited maxima at 274 and 410 nm, and a shoulder at 330 nm. The molecular mass was 115 kDa with two identical subunits of 58 kDa. The enzyme oxidized cholest-5-en-3beta-ol (cholesterol) and 5alpha-cholestan-3beta-ol (dihydrocholesterol) at a high reaction rate, and the K(m) value for cholesterol was 65 microM. The stability of the enzyme was higher than other CHOs in nonionic detergents with high values of hydrophilelipophile balance (HLB) such as Triton X-450 and sodium cholate. NH2-terminal sequence analysis showed a high similarity to CHO from Burkholderia cepacia, but not to CHOs from Streptomyces or Brevibacterium.     

Estimation of daily intake of phenols in hospital meal samples

Daily intakes of 12 phenols which are possible endocrine disruptors were estimated in hospital meals from 2000 to 2001. 4-Nonylphenol (4-NP (mix)) and bisphenol A (BPA) were detected at levels of 5.0 to 19.4 ng/g and 0.2 to 1.1 ng/g, respectively. 4-tert-Butylphenol, 4-n-pentylphenol, 4 -tert-pentylphenol, 4-n-hexylphenol, 4-n-heptylphenol and 4-tert-octylphenol were detected at levels of 0.1 to 2.4 microg/g. The daily intakes of 4-NP (mix) and BPA were 5.8 microg/day and 0.42 microg/day, respectively. The daily intakes of other phenols were less than 1 microg/day.     

Mutational analysis of structure--activity relationships in human tumor necrosis factor-alpha

To determine the region of human tumor necrosis factor-alpha(TNF-), essential for cytotoxic activity against mouse L-M cells,single amino-acid-substituted TNF- mutant proteins (muteins)were produced in Escherichia coli by protein engineering techniques.An expression plasmid for TNF- was mutagenized by passage throughan E.coli mutD5 mutator strain and by oligonucleotide-directedmutagenesis. Approximately 100 single amino-acid-substitutedTNF- muteins were produced and assayed for cytotoxic activity.The cytotoxic activities of purified TNF- muteins, e.g. TNF-31T,-32Y, -82D, -85H, -115L, -141Y, -144K and -146E, were < 1%of that of parent TNF-. These results indicate that the integrityof at least four distinct regions of the TNF- molecule is requiredfor full biological activity. These regions are designated asfollows: region I, from position 30 to 32; region II, from position82 to 89; region III, from position 115 to 117; region FV, fromposition 141 to 146. In addition, TNF-141Y could not completelycompete with parent TNF- for binding to the receptor. This demonstratesthat region IV, and at least aspartk acid at position 141, mustbe involved in the TNF receptor binding site.     

New type of pressurized cultivation method providing oxygen for piezotolerant yeast

For efficient oxygen supply to pressurized culture, we developed a method using a highly pressurized membrane reactor with an air-saturated medium circulation system. The new method increased the cell growth of aerobic yeast approximately 20 folds larger than that in the case of using a conventional method.     

Synchronal measurement of flow structure and heat transfer of impingement jet

This paper will present the characteristics of flow behavior and thermal field of both free and
impingement jet issued from a circular orifice nozzle at Re=8900.The flow behavior of a single round
jet and impingement jet was observed by smoke flow visualization recorded by a high speed camera
using 5000 frame per second.Heat transfer coefficient on the impingement surface was measured by
means of infrared camera （TVS-8500,Avio） with a two-dimensional array of Indeum-Antimony （In Sb）
sensors varying in the separation distance between the nozzle and the target plate.The heat transfer
coefficient changes in time and spatial.Therefore,the root mean square distribution of the heat
transfer was obtained from the data.As a result,it was confirmed that the longitudinal vortex was
observed outside of the ring vortex,and then the longitudinal vortex was penetrated in the jet
flow.Moreover,the high value of root mean square of the heat transfer coefficient has spread radially
in stripy manner,which is caused as the results of the longitudinal vortexes flowing in the radial
direction on the impingement plate.     

Enhancing low-temperature energy harvesting by lead-free ferroelectric Ba(Zr0.1Ti0.9)O3

The energy-harvesting ability of the lead-free ferroelectric Ba(Zr,Ti)O₃ was investigated and greatly enhanced using the Kim novel electrothermodynamic cycle for low-temperature application. Ba(Zr,Ti)O₃ was synthesized with a Zr:Ti ratio of 10:90 (BZT10) by hot-press sintering, which exhibited a mix relaxor-ferroelectric behavior. For power generation using the Kim cycle with low and high temperatures of T_L = 25°C, T_H = 120°C, the most optimized temperature pattern occurred for a heating time of 12.5 s and a cooling time of 22.5 s. Under these conditions, the electric field increased during the novel isodisplacement process, and the displacement variation in the isoelectric step reached the highest value and maximized the BZT10 cycle loop area. Applying these conditions while lowering T_L to 20°C, an energy density N_D = 504 mJ/cm³ was achieved. This value is the highest obtained energy density in a practical test for lead-free ferroelectric bulk material in the BaTiO₃ family.