STUDY OF AN ORGANIC CRYSTALLIZATION FOULING PROBLEM

One of the aromatic compound plants in Mitsubishi Chemical Corporation has a heavy crystallization fouling problem. We have been studying the crystallization process using the shell and tube heat-exchanger. In order to solve our fouling problem of the heat exchanger, we developed the specified evaluation equipment (crystallization fouling simulator : CFS) which consists of a single tube heatexchanger (Tube size: ID=10.3mm Length=500mm). The result of the modeling for describing the crystallization fouling rate and the countermeasure of the fouling problem are discussed in this work. It can be possible to describe the fouling rate as one equation which has two parameters, and the fouling rate of the industrial plant and the evaluation equipment agree with each other

The Influence of Illumination Color on the Subjective Visual Recognition of Biological Specimens

[Background] Visual examination by the naked eye is integral to medical diagnosis and surgery. The illumination in conditioned color is widely used for visual inspection in the industry but has not been introduced to the biomedical context. The color that can enhance the visual recognition of individual tissues is still unknown. Therefore, we carried out a visual recognition experiment on biological specimens to determine the subjective preference for illumination color based on questionnaires. [Methods] Twenty healthy subjects were asked to compare the visual recognizability of several rat tissues between the illuminations in test colors and white. The rats were anesthetized, and the femoral vein and abdominal cavity were exposed. Seven tissues were selected for a visual recognition test. Illumination was generated using a multi-color LED light. The subjects observed the tissues under the illuminations of white and one of the test colors alternately and reported which illumination is suitable for visual recognition using a questionnaire. [Results] The analysis of the questionnaires showed that the blue test color was more effective than white illumination in the visual recognition of fine structures such as the branching of blood vessels and nerves, and red illumination disturbed the visual recognizability of the same tissues. On the other hand, the red but not the blue illumination improved the visual recognizability of the vein beneath the intact skin. As to the recognition of individual tissues in the abdominal cavity, the white illumination gave a better visual recognizability compared to every other test color. [Conclusion] This study shows that the illumination color influences the visual recognition of biological specimens and the adequate color for the visual recognition of specific tissue parts is distinct among biological specimens. Using the lighting system to make fine adjustments to the illumination color may be useful in medical diagnosis and surgery

Measurement and Modeling for the Mitigation of Organic Crystallization Fouling

One of the aromatic compound plants in Mitsubishi Chemical Corporation has a heavy crystallization fouling problem. In order to solve this problem, using a low power gamma ray sensor, we found the location of heaviest fouling and measured the fouling growth rate. We also made a crystallization fouling laboratory test unit (simulator) to study the effects of some factors, such as temperature, liquid velocity, surface roughness and liquid composition. Fouling rates of the industrial plant cooler and the laboratory fouling test unit were modeled using a combination of Kern-Seaton and Reitzer models. However, the parameters of the plant and test unit did not agree with each other, perhaps because of scale up problems. We also measured the melting process (removal) of the fouling with the test unit. The heat flux necessary to melt the foulant was measured and used for the actual plant melting system. In the industrial plant, a steam trace melting system was installed at the position of heaviest fouling, and the plant now runs better than before

Bulletin of Faculty of Education, Nagasaki University : Natural Science

The permeation behavior of hydrogen through pure aluminum has been investigated in the temperature range of 625 K to 778 K by a gas permeation technique. The permeation rate of hydrogen was strongly affected by the conditions of the surface where the hydrogen was introduced into the sample. They varied characteristically by repeating the permeation run, which was bounded in the temperature range of 690K to 700K. At a higher temperature than 700K, the surface oxide layer was reduced by hydrogen during the permeation run, which resulted in the larger permeation rate of hydrogen in the subsequent permeation runs. At the sensitized surface by the reduction, the temporary poisoning took place and the permeation rate of hydrogen was decreased. The poisoned surface, however, was cleaned by keeping the sample under high vacuum at a higher temperature than 700K. The poisoning was closely related to the presence of carbon and its compounds on the top surface where the hydrogen was introduced into the sample

Knee Joint Thrust During the Early Stance Pahse of Gait Cycle

This paper is performed to evaluate with the knee joint motion of the active flexion (without weight bearing motion) and of the early stance phase during gait cycle (with weight bearing motion) by using a three-dimensional knee motion analysis system and the biomechanical pathogenesis of osteoarthritic knee is also discussed. Assessments were practiced about the knee motion of eighteen female patients with osteoarthritic knees; the controls were sixty-five volunteers of the adult healthy group including thirty-four males and thirty-one females. Typical motion patterns of active flexion and of early stance phase during gait cycle were evaluated to detect the difference based on osteoarthritis levels and gender. In results of this study, changes of adduction and internal rotation were appeared in the knee motion pattern during active flexion and early stance phase during gait cycle. During the active flexion, the mean values of adduction angle during flexion were 0.38±0.22 degrees in male group(MG), O.18±0.28 degrees in female group(FG) and 0.29±0.21 degrees in osteoarthritic knee group(OAG). On the other hand, in the early stance phase, the mean values of adduction angle during flexion were 0.29±0.21 degrees in MG, and were 0.29±0.27 degrees in FG and 0.87±0.48 degrees in OAG. During weight bearing motion of OAG, adduction angles increased to 0.58 degrees in the osteoarthritic knee, remarkably, that should mean as a phenomenon of the knee thrust. The thrust of OAG might be related to the joint laxity, deterioration of power in the quadriceps femoris muscle, the problem of their body weight and of aging. In the present study, the biomechanical pathogenesis of an osteoarthritic knee would be discussed about factors of osteoarthritic knee and be presented a few sources of knee osteoarthritis of femal quantitatively

Radiotherapy using a laser proton accelerator

Laser acceleration promises innovation in particle beam therapy of cancer where an ultra-compact accelerator system for cancer beam therapy can become affordable to a broad range of patients. This is not feasible without the introduction of a technology that is radically different from the conventional accelerator-based approach. The laser acceleration method provides many enhanced capabilities for the radiation oncologist. It reduces the overall system size and weight by more than one order of magnitude. The characteristics of the particle beams (protons) make them suitable for a class of therapy that might not be possible with the conventional accelerator, such as the ease for changing pulse intensity, the focus spread, the pinpointedness, and the dose delivery in general. A compact, uncluttered system allows a PET device to be located in the vicinity of the patient in concert with the compact gantry. The radiation oncologist may be able to irradiate a localized tumor by scanning with a pencil-like particle beam while ascertaining the actual dosage in the patient with an improved in-beam PET verification of auto-radioactivation induced by the beam therapy. This should yield an unprecedented flexibility in the feedback radiotherapy by the radiation oncologist. Laser accelerated radiotherapy has a unique niche in a current world of high energy accelerator using synchrotron or cyclotron.Comment: 26 pages, 8 figures, 2 tables, 69 references. International Symposium on Laser-Driven Relativistic Plasmas Applied for Science, Industry and Medicine, Kyoto, Japan, 17-20 September (2007

Biomenchanical Analysis on the pathogenesis of Knee Osteoarthrosis

The three-dimensional knee joint motion data during level walking were obtained from 34 males and 33 females using a 6-degree-of-freedom electrogoniometer. Normal motion pattern of active flexion (full extension to 20deg. flex.), active extension (20deg. flex. to full extension) and early stance phase during gait cycle were evaluated to find the physical difference based on sex and age. Adduction and internal rotation (male 85.3%, female 66.7%) were shown in the normal motion pattern during active flexion of the knees while abduction and external rotation (male 91.2%, female 90.9%) were found in the pattern during active extension of the knees.The screw home motion is detected during active extension (male 61.8%, female 90.9%). Adduction and internal rotation (male 97.1%, female 81.8%) were shown in the normal motion pattern during early stance phase. Females tend to change the pattern of motion with weight bearing. Adduction at early stance phase and abduction under active flexion are shown in females by 12.9%. On the other hand, there is the pattern change by only 2.9%, in males. This gender difference seems to be related to a general tendency of joint laxity in f emales