Performance evaluation of multi-stage, multi-bed adsorption chiller employing re-heat scheme

This paper deals with the performance investigation of a silica gel/water-based multi-stage, multi-bed, six-bed adsorption chiller employing re-heat scheme. The innovative chiller is powered by waste heat or renewable energy sources of temperature between 50 and 70 °C along with a coolant of inlet temperature at 30 °C for air-conditioning purpose. The performance of the six-bed adsorption chiller using re-heat scheme is compared with that of the six-bed chiller without re-heat. With the same operating conditions, such as the heat transfer fluid inlet (HTF) temperatures, HTF flow rates, adsorption/desorption cycle time and same chiller physical dimension, it is found that both the cooling capacity (CC) and the coefficient of performance (COP) of the three-stage chiller with re-heat scheme are superior than those of the three-stage chiller without re-heat scheme.     

WIDE RANGE DETECTOR USING PARABOLIC CYLINDRICAL MIRROR FOR THz APPLICATIONS

A new, wide-band, high-speed and high-sensitivity THz detector has been developed. The prototype detector consists of a parabolic cylindrical mirror, a long wire antenna and a Schottky barrier diode. Direct detection measurements have shown a stable sensitivity of 150 ± 50 V/W for 1–2 THz without any adjustments. The long wire antenna was fixed at the focus of parabolic cylindrical mirror then it has been realized less operation steps, easy coupling to the external THz signals and a dramatic enhancement in the practicality of this system. The optically polished mirror and frosted surface one showed comparable sensitivities, thus easy polishing and less cost mirror fabrication can be applied for this system. The radiation pattern showed a maximum radiation angle of approximately 23° with its dominant main lobe, which was attributed to the wire antenna character and confirmed good agreements with classical antenna theory.     

Stage-dependent distribution of calreticulin in oocytes of the frog, Rana rugosa

We studied immunohistologically the distribution of a Ca2(+)-binding protein, calreticulin (CLT), at different stages of growing oocytes in the frog, Rana rugosa. Northern blot analysis showed that the CLT gene expression in gonads of metamorphosing tadpoles was low, but was extremely strong in the ovary, but not in the testis, of 2-month post-metamorphosis frogs, followed by decline to a lower level in adult frogs. On the contrary, the beta-actin gene expression did not increase in the same ovary. As for the distribution of CLT protein, a weak immunostaining was observed in indifferent gonads of tadpoles at stage I. The CLT distribution in oocytes from stage A to F was stage-dependent. In addition, Western blot analysis revealed that the CLT level was low in gonads of tadpoles at stage I, but increased at stage XVI. It still increased in the ovary of frogs 2 months after metamorphosis, and then dropped to a lower level in adult frogs. The results indicate that CLT gene expression occurs in the early stage of growing oocytes, and that CLT is synthesized actively in oocytes in the ovary of frogs after metamorphosis. Based on these findings, the role of CLT is discussed.     

Nanoparticle networks reduce the flammability of polymer nanocomposites

Synthetic polymeric materials are rapidly replacing more traditional inorganic materials, such as metals, and natural polymeric materials, such as wood. As these synthetic materials are flammable, they require modifications to decrease their flammability through the addition of flame-retardant compounds. Environmental regulation has restricted the use of some halogenated flame-retardant additives, initiating a search for alternative flame-retardant additives. Nanoparticle fillers are highly attractive for this purpose, because they can simultaneously improve both the physical and flammability properties of the polymer nanocomposite. We show that carbon nanotubes can surpass nanoclays as effective flame-retardant additives if they form a jammed network structure in the polymer matrix, such that the material as a whole behaves rheologically like a gel. We find this kind of network formation for a variety of highly extended carbon-based nanoparticles: single- and multiwalled nanotubes, as well as carbon nanofibres.     

A New Algorithm of MDA-OR II

Behaviormetrika - A fundamental idea of a new algorithm of minimum dimension analysis of ordered class belonging (MDA-OR) which is one of the methods for nonmetric multidimensional scaling (MDS) is...     

Projection lithography to print thick resist patterns with triangular and semi-circular cross-section profiles

Patterning technology to print thick resist patterns with triangular and semi-circular cross-section profiles was investigated for applying to fabrication of light-guide plates and lens arrays, surface texturization of solar cells, and others. Positive novolac resist PMER P-LA900PM with an initial thickness of 10 μm was used and the patterns were mainly printed by the exposure light with a wavelength of 405 nm. At this wavelength, the light transmittance through the resist film was 0.5% and 80% before and after the exposure, respectively. Caused by this moderate transmittance characteristics, pattern sidewalls suitably inclined or roundly curved. When 400 μm line-and-space reticle patterns were printed using a projection exposure lens with a reduction ratio of 1/19 and a numerical aperture of 0.125, triangular patterns were obtained under the defocus conditions of around ?100 μm. The sidewall angle was widely controlled between 20° and 55° by mainly changing the exposure time. On the other hand, semi-circular profiles were obtained when patterns were printed at the defocus position of +100–200 μm. It was clarified that the circular radius depended only on the defocus position and did not depend on the exposure time. Patterns with circular radiuses of 9–34 μm were successfully obtained.     

Very high cycle fatigue properties of bearing steel under axial loading condition

It has been observed to appear a step-wise or duplex S–N curve under the test of rotary bending fatigue using high strength steel. This behavior was caused by the transition of fracture mode from surface-induced fracture to subsurface inclusion-induced fracture. The aim of this study is to clarify the S–N characteristic under an axial loading fatigue in the very high cycle fatigue regime. In order to investigate the mean-stress effects, fatigue tests were carried out in air at room temperature under three applied stress ratios of ?1, 0 and 0.5 using a hour-glass shaped specimen of high carbon–chromium bearing steel, JIS SUJ2. From the results, three types of fracture mode were observed on the fracture surface, such as surface-induced fracture, subsurface inclusion-induced fracture without granular bright facet (GBF) area and that with GBF area around an inclusion. Fatigue lifetime for transition in the fracture mode depended on the applied stress ratio. Shape of the S–N curve was a smooth and continuous under three testing conditions in spite of the occurrence on the three types of fracture. Detail discussion for fatigue fracture behavior was made through the observation of fracture surface and from point in view of the fracture mechanics. In addition, an effect of residual stress in the specimen surface layer on the transition of fracture mode was discussed and compared with the experimental results.