An analytical model for predicting dryout point in bilaterally heated vertical narrow annuli

Based on the droplet-diffusion model by Kirillov and Smogalev (1969, 1972), a new analytical model of dryout point prediction in the steam-water flow for bilaterally and uniformly heated narrow annular gap was devel- oped. Comparisons of the present model predictions with experimental results indicated that a good agreement in ac- curacy for the experimental parametric range (pressure from 0.8 to 3.5 MPa, mass flux of 60.39 to 135.6 kg?m-2?s-1 and heat flux of 5 to 50 …     

Solution of laplace equation by the method of separation of variables

Abstract

The Laplace equation, which is used to describe the problem of two‐dimensional heat conduction with appropriate boundary conditions at steady state, is solved in this work by applying the method of separation of variables. The primary objective of this work involves discussing the effects of the constant value of the separation of variables (p) and the sequential order of substituting boundary conditions on the solution. Without appropriately arranging the sequential order of substituting the boundary conditions, the solution for non‐zero constant values of separation of variables (p) can not be obtained. For a zero value for the constant of the separation of variables, the solution obtained is trivial or does not exist. Solutions in different forms are obtained by using different values for the constant of the separation of variables (p) and for the sequential orders of substituting the boundary conditions.     

A study on physical and mechanical properties for soft to firm clays in Yangon area – Properties of clays deposit at the sedimentary basins in Myanmar

Recently, a great deal of foreign investment has been entered into construction of the social infrastructure of Myanmar. Many construction projects are therefore on-going, and these are especially planned in the Yangon area. While these construction booms are increasing, existing studies on the geotechnical problems in the Yangon area such as problematic soils like soft clays are limited at present. Information on soil properties has also not been shared and has been confined to individual projects. In this paper, the boring and laboratory tests carried out in the Yangon area are selected and focused upon among the tests carried out in Myanmar. Laboratory test results for clay deposits in the Yangon area are analyzed and the differences in soil properties between different sedimentary basins and sub-areas divided by the Tertiary sediment ridge that runs from north to south at the center of Yangon are clarified together with a comparison to the clays found in other countries, which have been previously investigated.     

Extraction of phenol by sulfuric acid salts of trioctylamine

Abstract

The extraction of phenol from an aqueous solution using sulfuric acid salts of trioctylamine (TOA salts) was carried out. Trioctylamine (TOA) dissolved in diisopropyl ether (DIPE) (or 1‐octanol, cyclohex‐ane, benzene and kerosene) was evaluated for extraction of phenol at various volume ratios of organic phase to aqueous phase at varied temperatures. The equilibrium distribution coefficient (K_D ) for the extraction of phenol with TOA salts in those diluents was measured. Phenol is extracted by a physical distribution with pure diluent alone and through the interaction between TOA and phenol. The latter was quantitatively interpreted according to a reaction scheme in which adducts of several kinds were composed of trioctylamine and phenol. The TOA salts have a significantly greater extraction capability for phenol than TOA itself. The reaction of phenol and hydroxide ion to form phenoxide ion is used to explain the small extraction of solute at high pH. A simple mathematical model was derived to account for the effect of the volume ratio of organic phase to aqueous phase on the value of K_D, and for the effect of the initial concentration of phenol on the value of K_D.     

Studies on therapeutic activity of benzoxazinorifamycin KRM-1648 in combination with other antimicrobial agents and biological response modifiers interferon-gamma and granulocyte-macrophage colony-stimulating factor against M. leprae infection in athymic nude mice

Immunological abnormalities (IA) are frequently observed in patients with myelodysplastic syndromes (MDS). Although there have been a number of analyses of the prognostic factors, there have been few studies, if any, to determine whether IA affects prognosis. We investigated the prognosis of 153 MDS patients with or without IA who were treated at a single Japanese institute for 10 years. Nineteen of 153 patients (12%) developed autoimmune disorders. One hundred of 153 patients (63%) had an abnormality in at least one immunological laboratory test. Hypergammaglobulinemia was found in 50 of 128 (39%) patients tested, hypogammaglobulinemia was observed in 10 of 128 (8%), positivities of antinuclear antibody, RA factor. DNA antibody, and direct antiglobulin test were observed in 30%, 14%, 7% and 12%, respectively, and a CD4/CD8 ratio < 1 was observed in 20%. There was no significance in the distribution of age, MDS subtype, or sex between patients with and without IA. The survival of MDS patients without IA was significantly better than that of patients with IA, and the survival of patients with a CD4/CD8 ratio > 1 was also significantly superior to the survival of those with an inverted CD4/CD8 ratio. Patients with IA tended to die of infection or leukemic progression in comparison with those without IA, suggesting that IA may be associated with susceptibility to opportunistic infection and disease progression.     

Mitochondrial mutation associated with nonsyndromic deafness

Although conservative management with or without manipulation performed with the patient under anesthesia is the generally accepted treatment strategy for adhesive capsulitis, considerable interest is being shown in arthroscopic surgical procedures for this disorder. This study reviews the outcome of patients who underwent an arthroscopic release of the inferior capsule, reproducing in a controlled fashion the traumatic disruption of the inferior capsule commonly caused by manipulation with the patient under anesthesia. The outcome of 24 patients (26 shoulders) was assessed with an average follow-up of 13.5 months. A total of 88% of patients were very satisfied with the procedure, and no operative complications occurred. A return to normal or near normal shoulder function in 76% or more of the study group for forward flexion, abduction, and external rotation was demonstrated. A total of 50% of patients still had some restriction in internal rotation. The Constant Scoring system, also used to assess clinical shoulder function, revealed 87% of patients had achieved an excellent or good result when compared with the contralateral normal shoulder score. Our results suggest that arthroscopic capsular release is a safe and effective treatment for adhesive capsulitis, with patterns of recovery that compare favorably to other treatment modalities.     

NUCLEATE POOL BOILING IN A CONFINED SPACE

Nucleate pool boiling of pure water and dilute aqueous sodium lauryl sulfate (SLS) solutions within a confined space between heated and unheated horizontal-parallel surfaces has been investigated under atmospheric pressure. The electrically heated lower surface is made of a sheet of stainless steel 304 with the dimension of 145 × 22 × 0.05 mm and the unheated upper plate is a stainless steel cylinder with a diameter of 20 mm. Periphery of the confined space is open and the size of the gap can be varied from 0 to 10 mm. Experimental results show that with the size of the gap between 0.3 and 3 mm, the heat transfer coefficient may increase to as much as 200 percent of those measured for conventional pool boiling. The addition of surfactant has no significant influence on the heat transfer coefficient in this case. Based on the experimental results, the microlayer evaporation with fluid flow driven by the gradient of disjoining pressure is discussed and considered as an important heat transfer mechanism for nucleate pool boiling in confined spaces     

Dual-eyes Vision-based Docking System for Autonomous Underwater Vehicle: an Approach and Experiments

A critical challenge for autonomous underwater vehicles (AUVs) is the docking operation for applications such as sleeping under the mother ship, recharging batteries, transferring data, and new mission downloading. The final stage of docking at a unidirectional docking station requires the AUV to approach while keeping the pose (position and orientation) of the vehicle within an allowable range. The appropriate pose therefore demands a sensor unit and a control system that have high accuracy and robustness against disturbances existing in a real-world underwater environment. This paper presents a vision-based AUV docking system consisting of a 3D model-based matching method and Real-time Multi-step Genetic Algorithm (GA) for real-time estimation of the robot’s relative pose. Experiments using a remotely operated vehicle (ROV) with dual-eye cameras and a separate 3D marker were conducted in a small indoor pool. The experimental results confirmed that the proposed system is able to provide high homing accuracy and robustness against disturbances that influence not only the captured camera images but also the movement of the vehicle. A successful docking operation using stereo vision that is new and novel to the underwater vehicle environment was achieved and thus proved the effectiveness of the proposed system for AUV.