Plugging problems observed in severe hydrocracking of vacuum residue

Carbons deposited on the filter after the reactor of hydrocracking (US-Sludge) and in the heat exchanger (DS-Sludge) in a commercial H-Oil process were analyzed through the elemental analysis, XRD, SEM, optical microscope, ¹³C-NMR and Raman spectroscopy to elucidate their formation mechanism. Heat treatment of sludge and oil products recovered from the commercial process was performed at 698 K of a reaction temperature. XRD showed the presence of Fe_1−xS, NaCl, and CaSO₄ as well as carbon (2Θ = 26.6°) in US-Sludge. The carbon showed medium and fine mosaic textures surrounding the isotropic grains. DS-Sludge showed mixed texture of domain and flow surrounding the fine mosaic grains. The sludge consisted of stacked carbon flakes with a number of pores on the surface. EDX showed dominant presence of NaCl and CaO particles in the mosaic region. Heat treatment of asphaltene in the product mixed with US-Sludge gave the same appearance to that of DS-Sludge. US- and DS-Sludge are concluded to be formed through the respective carbon formation in the reactor and to be separated on the filter and on the heat exchanger surface, respectively. The carbon particles produced in the reactor collect contaminant Fe_1−xS and CaSO₄ particles to form the agglomerate where the growth and coalescence of the anisotropic spheres are very restricted to form the fine mosaic texture as observed in the US-Sludge. In contrast, the carbonization of the major precipitated heavy aromatic component leads to the domain or flow anisotropic texture through rather free growth and coalescence of anisotropic spheres on the surface of the heat exchanger wall. Although some parts of precipitated component together with US-Sludge give mosaic texture through the restricted growth and coalescence of anisotropic sphere by the presence of reactive fine solids.     

Microstructural Cause of the Peak Effect in Superconducting Y-Ba-Cu-O Melt-Grown Bulks

Superconducting Y-Ba-Cu-O bulks with J _c as high as 30 kA /cm ² (at 77 K and 1 T) containing both Y-123 and Y-211 phases were utilized in the present work . With different post-annealings, we obtained samples with different degrees of peak effect in the J _c -vs- H characteristics. Using specimens with TEM observable areas as wide as 20 × 20 (m) ² , large-area high-resolution transmission-electron-microscopic (LA-HRTEM) observations were made for the samples with different degrees of peak effect. Statistical analyses were made for the size of Y-211 particles and the distance between adjacent twin boundaries. It is revealed that (1) Y-211 particles including those of very small diameters have nothing to do with-the peak effect, while (2) the inter-twin-boundary distance is undoubtully correlated with the degree of peak effect. Further investigation on the twin boundary structure indicates that lower T _c regions may be formed in the vicinity of twin boundaries to provide fluxons with mesoscopically distributed weak pinning centers.     

无铬无脂猪革的性能

制革废水及革制品废料所含铬引起的环境与卫生污染是一个严重的问题。加脂可以影响皮革的性能，其目的就是赋予成革以柔软性，良好的手感和一定的强度，缺点是加脂使革重量增加，抗水性减弱，有时还会引起增塑剂和染料的迁移。为解决此问题，本论文采用不使用铬和加脂剂的方法来处理皮革，并对以这种方法所加工皮革的性能进行研究。结果如下：（１）对于剖层，削匀或修边等废料，因其不含铬而可加以利用或焚烧处理；（２）所制成革具有防水性，性能优于防水性的革；（３）成革视密度下降；（４）染色革的耐光性明显优于荆树皮～铝鞣革，后者系典型的非铬鞣革之一，此法还可有效防止白色革泛黄。     

Interference-based electrochemical biosensor for the measurement of the concentration and isomer ratio of urocanic acid

Urocanic acid (UCA) is known to be synthesized as the trans isomer (trans-UCA) in the skin, and trans-UCA is transformed by UV light to the cis isomer (cis-UCA), which may be involved in photoimmunosuppression. An electrochemical method has been developed for the measurement of the concentration and isomer ratio of UCA. A heme peptide-modified electrode (HP electrode) reduces hydrogen peroxide at +150 mV vs Ag/AgCl, and the reduction current is inhibited by UCA. Since cis-UCA is a stronger inhibitor than trans-UCA, irradiation of a sample solution with UV light increases the percent inhibition. The concentration and isomer ratio of UCA in the sample solution can be estimated from the values of percent inhibition before and after the UV irradiation.     

Learning block-preserving graph patterns and its application to data mining

Recently, due to the rapid growth of electronic data having graph structures such as HTML and XML texts and chemical compounds, many researchers have been interested in data mining and machine learning techniques for finding useful patterns from graph-structured data (graph data). Since graph data contain a huge number of substructures and it tends to be computationally expensive to decide whether or not such data have given structural features, graph mining problems face computational difficulties. Let be a graph class which satisfies a connected hereditary property and contains infinitely many different biconnected graphs, and for which a special kind of the graph isomorphism problem can be computed in polynomial time. In this paper, we consider learning and mining problems for  . Firstly, we define a new graph pattern, which is called a block preserving graph pattern (bp-graph pattern) for  . Secondly, we present a polynomial time algorithm for deciding whether or not a given bp-graph pattern matches a given graph in  . Thirdly, by giving refinement operators over bp-graph patterns, we present a polynomial time algorithm for finding a minimally generalized bp-graph pattern for  . Outerplanar graphs are planar graphs which can be embedded in the plane in such a way that all of vertices lie on the outer boundary. Many pharmacologic chemical compounds are known to be represented by outerplanar graphs. The class of connected outerplanar graphs satisfies the above conditions for  . Next, we propose two incremental polynomial time algorithms for enumerating all frequent bp-graph patterns with respect to a given finite set of graphs in  . Finally, by reporting experimental results obtained by applying the two graph mining algorithms to a subset of the NCI dataset, we evaluate the performance of the two graph mining algorithms.     

A Generalization of Magic Squares with Applications to Digital Halftoning

A semimagic square of order n is an n×n matrix containing the integers 0,…,n ²−1 arranged in such a way that each row and column add up to the same value. We generalize this notion to that of a zero k×k -discrepancy matrix by replacing the requirement that the sum of each row and each column be the same by that of requiring that the sum of the entries in each k×k square contiguous submatrix be the same. We show that such matrices exist if k and n are both even, and do not if k and n are relatively prime. Further, the existence is also guaranteed whenever n=k ^m , for some integers k,m≥2. We present a space-efficient algorithm for constructing such a matrix. Another class that we call constant-gap matrices arises in this construction. We give a characterization of such matrices. An application to digital halftoning is also mentioned. A preliminary version of this paper appeared in Proceedings of International Symposium on Algorithms and Computation, Hong Kong, December, 2004. Part of the work on the paper has been carried out when B.A. was visiting JAIST. Work of B.A. on this paper was supported in part by NSF ITR Grant CCR-00-81964. Work of T.A. was partially supported by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research (B).     

Continuous measurements of bronchial exposure induced by radon decay products during inhalation

The deposition of radon decay products is not equal in each of the respiratory regions and as the presence of radon has been linked with an increase in lung cancer risk, it is important to calculate the deposition of radon decay products in each of the respiratory regions. Recently, many studies on the deposition of radon in respiratory regions have been simulated using wire screens. The systems and equipment used in those studies are not suitable for field measurements as their dimensions are relatively massive, nor can they measure continuously. We developed a continuous bronchial dosimeter (CBD) which is suitable for field measurements. It was designed with specifications that allow it to be remain compact. The CBD simulates the deposition of radon decay products in the different respiratory regions by the use of a combination of wire screens. Deposition in the simulated regions of the lung can be continuously estimated in various environments. The ratio of activities deposited in a simulated nasal cavity (N) and tracheobronchial (TB) regions was calculated from the results of simultaneous measurements using CBD-R (reference), CBD-N (nasal), and CBD-TB (tracheobronchial) measurement units. After aerosols were injected into the radon chamber, the ratio of N and TB depositions decreased. This results indicate that the CBD gave a good response to changes in the environment. It was found that the ratio of N and TB deposition also varied with time in each actual environment.     

High-temperature stability of Nicalon under Ar or O2 atmosphere

The thermal stability of Nicalon NL400 at 1573, 1673 and 1773 K has been studied by TGA and XRD. Under an Ar atmosphere, Nicalon pyrolysed severely to crystallize into -SiC involving the generation of both SiO and CO. Under an O₂ atmosphere, the oxide film which formed around Nicalon retarded the pyrolytic reaction of the core. Nicalon coated with a silica film by the previous oxidation treatment pyrolysed hardly at all under an Ar atmosphere, because the film restricted the escape of SiO and CO. Nicalon which was oxidation-treated at 1773 K retained 63% of its original strength after heating at 1773 K under an Ar atmosphere. The amorphous silica film was found to resist rapid thermal cycling between room temperature and elevated temperatures.     

A new wettability‐control technique for fabricating color OLED panels by an ink‐jet‐printing method

Abstract— The fabrication technique for color OLED panels by means of wettability‐controllable hole‐injection material (HIM) and a photocatalytic lithography method achieves both precise ink‐jet printing and long‐lifetime devices. The technique enables us to selectively change the non‐wetting surface of a hole‐injection layer (HIL) of metal‐oxide nanoparticles (MONPs) into a wetting surface without damage to the device performance. Wetting patterns formed by this method with photocatalyst‐coated photomasks made it possible to print emission material with patterns of precisely 98‐μm widths on the hole‐injection layer. A fluorescent green‐emitting device fabricated with an HIM of MONPs by the photocatalytic treatment exhibited a long lifetime of 365 hours at30,000 cd/m², which can be extrapolated to a lifetime of more than 110,000 hours at 1000 cd/m², assuming an acceleration coefficient of 1.7. A two‐color device and a monochrome passive‐matrix panel were also successfully fabricated. The two‐color device emitted light without the mixing of colors. The monochrome panel displayed alphabetical characters with good uniformity and no flaws.