Studies on Bile Pigments II. Seperation of Natural Direct Bilirubins

Separation of both forms of the direct bilirubin were carried out from the dog's gallbladder bile, and further isolations of them were also done. 1. The natural salt-form bilirubin was isolated after separation on the column of aluminium oxide with a n-propanolic aqueous solution. 2. The natural salt-form bilirubin was obtained in amorphous yellow powders which were strongly hygroscopic and easily soluble in water and methanol but not in chloroform or carbon tetrachloride. An aqueous solution of these powders showed both the direct diazo and Gmelin reaction, but neither Ehrlich's aldehyde nor Schlesinger reaction. The salt-form bilirubin was transferred into chloroform only when some quantities of hydrochloric acid were added to a mixture of chloroform and an aqueous solution of it. 3. The absorption maxima of the natural salt-form bilirubin existed at 420 to 430 m&#956; in a methanolic solution and at 425 or 435m&#956; in 50% or 10% n-propanol. 4. The natural ester-form bilirubin was isolated after separating on the column of silica gel with a chloroformethanolic mixture. 5. The natural ester-form bilirubin was obtained in amorphous greenish yellow powders. It was further hygroscopic and easily soluble in water and methanol but not in chloroform or carbon tetrachloride. An aqueous solution of it showed the direct diazo and Gmelin reaction, but neither Ehrlich's aldehyde nor Schlesinger's reaction. No pigment was transferred into chloroform even if some quantities of hydrochloric acid were added to a mixture of chloroform and an aqueous solution of it, but did by saponification with 5% methanolic potash. 6. The absorption maxima of the natural ester-form bilirubin existed at 415 m&#956; in both methanolic and aqueous solutions.</p

Studies on bile pigments V. A method to isolate indirect bilirubin

For the purpose of obtaining the dibasic acid indirect bilirubin in a pure state from the dried canine cholecystic bile, an optimal developing solvent was selected by paper partition chromatography as a preliminary experiment, and it was isolated on cellulose column as an applied experiment. 1. The dibasic acid indirect bilirubin was separable at the starting point in a pure state by paper chromatography under development with the top layer of a n-butanol, acetic acid, water mixture (4:1:5). 2. The dibasic acid indirect bilirubin formed a fixed band at the upper starting place on cellulose column under development with the top layer of a n-butanol, acetic acid, water mixture (4:1:5), and no other substance could be detected there. 3. The dibasic acid indirect bilirubin existing in the fixed band could be eluted out into chloroform with a 1% acetic acid solution. An orange yellow powder was obtained from the eluate by evaporating the solvent in vacuo. 4. Thus separated orange yellow powder agreed well with the crystalline bilirubin in the solubility into organic or inorganic solvents and in the spectrochemical characteristics as well as in the chemical properties.</p

Studies on Bile Pigments I. Separation of Natural Indirect Bilirubins

Descriptions are carried on the method how to separate the indirect bilirubin from the chloroform extracts of the dried dog's gallbeadder bile by adsorption chromatography. 1. The optimal concentrations of the bilirubin content were 2 to 4 mg/100 ml when 1 ml of the sample was adsorbed on the Tswett tube of about 10 mm diameter. 2. Though several zones of the indirect bilirubin were separated on the column of silica gel when developed with various solvents, these zones were proved to be mingled with some oxidized or other intermediate products and the separation like this was thought to owe to the activity of the adsorbents. 3. The chromatogram of the crystalline bilirubin resembled to the one formed by the indirect bilirubin in the chloroform extracts. 4. The chromatogram of the chromatographically separated indirect bilirubin was similar to the former. 5. The absorption maxima of a chloroform solution of the natural indirect bilirubin existed at 450 m&#956; in the visible range, and it was the same as the maxima of the crystalline bilirubins.</p

Studies on Bile Pigments III. Biliverdins Derived From Natural Bilirubins

1. Absorption maxima of hydrochloric biliverdins derived from the natural indirect bilirubin existed at 680 m&#956; and 375 m&#956;, but the maxima of biliverdins purified on the column of silica gel existed at 640 m&#956; and 390 m&#956;. 2. The natural salt-form bilirubin was oxidized by hydrochloric acid to biliverdin, of which absorption maxima existed at 685 m&#956; and 370 m&#956; in a methanolic solution as well as in 5% hydrochloric methanol, but the purified biliverdin in chloroform solution showed the maxima at 640 m&#956; and 390 m&#956;. 3. The natural ester-form bilirubin could be transformed into biliverdin by oxidation of its alcoholic solution in the presence of hydrochloric acid. The crude biliverdin had absorption maxima at 645 to 655 m&#956;, 600 m&#956; and 320 m&#956;, and the crude hydrochloric biliverdin had the maxima at 665 to 675 m&#956;, 620 m&#956; and in the near ultra-violet range, while the purified biliverdin in chloroform solution had the maxima at 640 m&#956; and 380 m&#956;. 4. The biliverdins derived from the indirect, salt-form and ester-form bilirubin had quite similar absorption maxima after purifications by adsorption chromatography.</p

Studies on bile pigments IV. Direct bilirubin in canine bile

Two forms of the direct bilirubin separated from the dried canine cholecystic bile were subjected to paper chromatography and emission or infra-red spectroscopy, and the following results were obtained: 1. The two forms of the direct bilirubin contain plenty of bile acid or its salt, and benzidine- and ninhydrine-positive substances together with various inorganic elements were also detected. 2. The ester-form bilirubin had carboxyl radical by infrared spectroscopy. But it will not be easily concluded that an existence of carboxyl radical will owe to free carboxyl radical of the dibasic acid bilirubin by the reason why an existence of plenty of bile acid in the sample may inhibit the characteristic absorption of ester. 3. It may be suggested that the two forms of the direct bilirubin combine with bile acid or its salt, and that the affinity between them is stronger in the salt-form bilirubin. 4. It seems probable that properties of the salt-form and ester-form bilirubins are not influenced by an existence of bile acid or its salt, and further by acornbination with it.</p

Development of Polyol Ester Refrigeration Oils for HFO Refrigerants

Recently, R32 refrigerant, which has low global warming potential (GWP), attracts much attention as an alternative one instead of R410A and has started to be used in practical system of room air conditioner (RAC), but compared with natural refrigerants, its GWP of 675 is still high and it is required to use refrigerants with much lower GWP. In addition, although R134a (GWP=1300) is widely used for mobile air conditioner systems (MAC), it has been decided by MAC directive in Europe that refrigerants whose GWP is over 150 can no longer be available in future. In such a situation, HFO refrigerants like R1234yf, R1234ze and AMOLEA [1] are considered as candidates for next-generation refrigerants because of their much lower GWP. Therefore, at the same time, it is required to develop refrigeration oils which have good compatibility with HFO refrigerants for RAC. One of the characteristics of HFO refrigerants is that their miscibility with refrigeration oils is equal to or greater than that of HFCs. However, the problem is that HFOs have a double bond in their molecular structure, resulting in their lower chemical stability than that of HFCs. We developed polyol ester (POE) refrigeration oil with high chemical stability under HFO atmospheres by improving formulation of additives. In this study, we will report the method and the characteristics of lubricity under HFOs. [1] M. Fukushima, M. Hashimoto, Development of Low-GWP Alternative Refrigerants , JRAIA the International Symposium on New Refrigerants and Environmental Technology 2014, (2014), 292-299

Prediction of the Fracture Location by Tensile Tests of Gray Cast Iron Based on the Dimensional Changes of Graphite Flakes

Gray cast iron has been used as a component in various mechanical parts, such as the blocks and heads of automobile and marine engines, cylinder liners for internal combustion engines, and machine tool bases. It is desirable because of its good castability and machinability, damping characteristics, and high performance-to-cost ratio. On the other hand, weak graphite flakes present in gray cast iron serve as stress concentrators and adversely affect the material strength. Therefore, it is crucial to examine the relationship between the distribution of graphite flakes and the strength or fracture of gray cast iron. In this study, tensile tests on gray cast iron were carried out using a plate specimen and observed by scanning electron microscopy, and the microscopic deformation was observed on the specimen surface. Particularly, the change in the size of graphite flakes during the tensile tests was examined, and the observed trend was discussed. The experimental results reveal that the dimensional changes in the graphite flakes vary in the observed area and that the final fracture occurs in an area where a large dimensional change is observed, suggesting that the fracture location or critical parts of gray cast iron can be predicted from the dimensional changes of the graphite flakes at an early stage of deformation

Decentralized Control Performances of an Experimental Web Handling System

Robust and good tracking control of the speed and the tension in web handling systems in spite of changes of set point is surely one of the important challenges in the web transport systems future development. In this paper, the authors experimentally demonstrate the real applicability of a decentralized robust control to a multi-span web transport system, which is composed of twelve guide rollers, four main sections mutually interconnected with each other. The overlapping methodology has been applied for the system decomposition. The experimental results carried out using the robust decentralized control show an excellent velocity and tension tracking in each controlled section of the system

Charge-density-wave superconductor Bi2Rh3Se2

We discovered a superconducting transition with the charge-density-wave state in a ternary compound Bi2Rh3Se2. This compound crystallizes in the parkerite-type structure composed of sheets containing one-dimensional Rh-Rh chains. The electrical resistivity, magnetic susceptibility, thermoelectric power, sample length change, and x-ray diffraction measurements reveal that this compound is in the CDW state below 240 K. Furthermore, the specific heat and electrical resistivity measurements show a superconducting transition at ~0.7 K. The various superconducting parameters were determined, and the GL parameter (0) shows the considerably large value of 151 indicating an extreme type-II superconductor