Combustion of NaN3 Based Energetic Pyrolants

The burning rate of pyrolants composed of NaN₃ and metal oxides was investigated in order to gain information on their combustion characteristics. The metal oxides mixed with NaN₃ were Fe₂O₃, CoO, Co₃O₄, and CuO. The effect of the addition of whiskers and fibers was also examined. The test results indicated that the burning rate was highly dependent on the type of ingredients and the mixture ratio of the ingredients. The pyrolant composed of NaN₃/CuO (61/39) appeared with the highest burning rate, 50 mm/s at 7 MPa, throughout the burning rate experiments. The residue of the combustion products of each sample was examined to evaluate the effectiveness of the gas generation.     

Studies on high‐speed melt spinning of noncircular cross‐ section fibers. I. Structural analysis of as‐spun fibers

Flat fibers and hollow fibers were prepared through the high‐speed melt spinning of poly(ethylene terephthalate) (PET), and the structures of these fibers were compared with those of circular fibers. The cross‐sectional shape of each fiber changed to a dull shape in comparison with that of the respective spinning nozzle. The change in the cross‐sectional shape was slightly suppressed with an increase in the take‐up velocity. There was a significant development of structural variation in the cross section of flat fibers in that the molecular orientation and crystallization were enhanced at the edge. Despite the difference in the cross‐sectional shape, the structural development of flat, hollow, and circular fibers with increasing take‐up velocity showed almost similar behavior. Considering that the tensile stress at the solidification point of the spin line is known to govern the structure development of high‐speed spun PET fibers, it was speculated that the effects of the enhancement of cooling and air friction on the tensile stress at the solidification point cancel each other. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1575–1581, 2001     

Fabrication of Si3N4 Ceramics with Metal Nitride Additives by Isostatic Hot-Pressing

High-density Si₃N₄ ceramics with nitride additives such as TiN, AlN, ZrN, VN, NbN, YN, TUN, Mg₃N₂, and HfN were fabricated by isostatic hot-pressing. The temperature dependence of Vickers microhardness, fracture toughness, and thermal conductivity were measured; these properties, as well as microstructure, were strongly influenced by the additive used.     

Simultaneous enhancement of cosmetic function and feel via molecular investigation of stickiness

The role of 18-methyleicosanoic acid was explored using atomic force microscopy techniques. Treatment with a delipidating agent (hydroxylamine) did not change the hair's morphology but dramatically changed its surface tribological properties, providing a high resolution mapping of the delipidation effect and confirming the importance of the presence of this fatty acid. Using nanolithography we were able to gently scratch the outermost surface layer of hair. The obtained depth of penetration remained constant (12–45 Å) and was very close to the average length of the 18-methyl-eicosanoic acid molecule, supporting the assumed model of an ordered monolayer of 18-methyleicosanoic acid on the surface. Taken together, our results suggest that the lipid covering or its grafting strength may not be evenly distributed over the hair surface. The possibilities of combining nanolithography and an analytical method like time of flight secondary ion mass spectroscopy (ToF-SIMS) are discussed.     

Solid Modeling Based on a New Paradigm

The technique of solid modeling is essential in CAD/CAM applications, and is currently well established. However, problems remain, such as the lack of uniformity in geometric computations and the lack of stability of Boolean operations of two solids. In this paper, we introduce a theoretical solid modeling system that operates on boundary representations of polyhedral objects and is based on a new paradigm. The characteristics of the system are the following: (I) in Boolean Operations and modeling transformations, all geometric computations are performed by the 4 × 4 determinant method or the 4 × 4 matrix method in homogeneous space, which allows the system to avoid division operations, (2) all geometric computations are performed by the exact integer arithmetic, which makes the geometric algorithms stable and simple, and (3) primitive solids are constructed consistently in the integer domain, and the consistency is assured throughout Boolean operations and transformations.     

An increased ratio of interleukin-1 receptor antagonist to interleukin-1alpha in inflammatory skin diseases

IL-1 receptor antagonist (IL-1ra) is a cytokine that competitively binds the IL-1 receptor to antagonize IL-1 activity without any agonist function. Previous experiments indicated that the ratio of IL-1ra to IL-1alpha in the normal stratum corneum (SC) was much higher in the sun-exposed face than in the sun-protected area, upper arms. It was also reported by another laboratory that IL-1ra is increased in the lesional skin of psoriatic patients. This study was designed to measure the contents of IL-1alpha and IL-1ra in non-lesional and pathological SC obtained from inflammatory skin diseases including psoriasis and non-psoriatic dermatoses such as atopic dermatitis. The SC materials were obtained with a non-invasive tape-stripping method. Their soluble fractions were prepared and assayed for IL-1alpha and IL-1ra by enzyme-linked immunosorbent assays. As a result we confirmed the previous findings that the ratio of IL-1ra to IL-1alpha in the normal SC was much higher in the face than in the sun-protected sites, the trunk as well as extremities. Next, we found that IL-1alpha contents were significantly reduced in the SC samples obtained from inflammatory skin regardless of whether their IL-1ra contents increased or unchanged. Moreover, we noted that an increased ratio of IL-1ra to IL-1alpha in the SC was not specific to psoriasis, but was also found in other inflammatory skin diseases including atopic dermatitis. This ratio was found to become lower after successful treatment of these skin lesions with topical glucocorticoids. We conclude from these observations that the increased ratio of IL-1ra to IL-1alpha in the SC is a non-specific phenomenon that can occur in any inflammatory skin diseases regardless of the inflammatory pattern, probably reflecting a skin regulation process against various kinds of inflammation.     

Emergence of karyotypically unrelated clone in remission of de novo acute myeloblastic leukaemias

The creation of effective cancer units is central to the implementation of the report A Policy Framework for Commissioning Cancer Services, produced by the Chief Medical Officers of England and Wales, recently issued by the Department of Health in April 1995. While cancer units are described in this report a range of important questions remain about their nature and how they should be developed. This paper addresses these issues in three ways. A definition of the cancer unit is suggested and its main implications spelt out. The problems of establishing cancer units are covered under three headings. Where should cancer units be? Which cancer sites should the unit cover? What is needed to establish the cancer unit? Finally two checklists are presented, describing the task from the perspectives of the district health authority and hospital(s) concerned. The underlying theme is that real changes in clinical practice and organisation are the goal, and these can only be achieved where there is extensive local dialogue in which the relevant issues are addressed in a structured and rigorous manner. Cosmetic changes in hospital designation will not achieve the consistent quality of cancer service that is the cornerstone of the 'Calman' policy.     

Streaming Algorithms for Biological Sequence Alignment on GPUs

In this paper, "Martini," a network interface controller chip for our original network called RHiNET, is described. Martini is designed to provide high-bandwidth and low-latency communication with a small overhead. To obtain high-performance communication, protected user-level zero-copy remote direct memory access (RDMA) communication functions are completely implemented by a hardwired logic. Also, to reduce the communication latency efficiently, we have proposed programmed I/O (PlO)-based communication mechanisms called "On the fly (OTF)" and have implemented them on Martini. The evaluation results show that Martini connected to a 64-bit/66-MHz peripheral component interconnect (PCI) bus achieves a 470-Mbyte maximum bidirectional bandwidth and a 1.74-musec minimum latency on host-to-host memory copying.     

Positologica: A Positron ECT Device with a Continuously Rotating Detector Ring

A rotary positron emission computed tomography device is developed for human brain and animal studies. The device utilizes 64 rectangular BGO detectors arranged at unequal spacing on a circular ring. The detector ring is continuously rotated at a constant speed of 60 rpm or less. This single continuous motion of the ring with the detector array provides excellent sampling characteristics and high detector redundancy. The device has a field of view 24 cm in diameter with a slice thickness adjustable from 1 cm to 2 cm. Measured width of system response to a 2 mm diameter line source is 5.8 mm FWHM at the center and less than 9 mm FWHM within a circle 16 cm in diameter. Measured sensitivity including scattered coincidence events is about 17 kcps/pCi/ml for a 20 cm diameter water phantom and 2 cm thick slice.     

Efficient method of adaptive sign detection for 4×4 determinants using a standard arithmetic processing unit

We propose an efficient and exact method for the adaptive sign detection of 4×4 determinants using a standard arithmetic unit. The entities of determinants are variable length integers (integers of arbitrary bit length). The integers are expressed in 16-bit data units, and the sign detection is reduced to the computation of 4×4 determinants of 16-bit integers. To accelerate the computation, the calculation is performed by using a standard arithmetic unit. We have implemented our method and confirmed that it significantly improves the computation time of 4×4 determinants. The method can be applicable to many geometric algorithms that need the exact sign evaluation of 4×4 determinants, especially to construct robust geometric algorithms.