Comparative study of large-scale hydrogen storage technologies: Is hydrate-based storage at advantage over existing technologies?

Different technologies possibly applicable for large-scale hydrogen storage in urban or industrial-complex areas have been comparatively evaluated, focusing on the facility-construction costs, the utility expense, and the ground area required for the facility for each technology. The specific technologies examined in this study are the storage in the form of compressed or liquefied gas, the storage using a metal hydride, and the storage using a clathrate hydrate. The common requirements for these technologies are the function of loading or unloading hydrogen gas at a rate up to 3000 Nm³/h and also the storage capacity of 6.48 × 10⁶ Nm³ that enables continuous 90-day loading or unloading at the rate of 3000 Nm³/h. The storage using a clathrate hydrate is found to require the minimum ground area and, if the cool energy necessary for hydrate production is available from adjacent LNG facilities, the minimum annual depreciation + utility expense.     

Process intensification of continuous starch hydrolysis with a Couette–Taylor flow reactor

Starch gelatinization and enzymatic hydrolysis was carried out in a continuous Couette–Taylor flow reactor with a water jacket. The degree of gelatinization and the concentration of reducing sugars produced via enzymatic saccharification were evaluated by varying operational variables: rotation speed of an inner cylinder, initial concentration of starch and reaction temperature. At the initial concentration of the starch suspension, 50 kg m⁻³, starch saccharification proceeded sufficiently even at low rotation speed of the inner cylinder and saccharification temperature. At the higher initial concentration, 100 and 150 kg m⁻³, a higher rotation speed of the inner cylinder and temperature of the saccharification section were required to obtain sufficient starch saccharification. Even in the case of C₀ = 100 and 150 kg m⁻³, the more reducing sugar was obtained by choosing an adequate rotation speed of the inner cylinder and a reaction temperature.     

Advancement of In-Flight Alumina Powder Spheroidization Process with Water Droplet Injection Using a Small Power DC-RF Hybrid Plasma Flow System

The correlation between plasma thermofluid characteristics and alumina powder spheroidization processes with water droplet injection using a small power DC-RF hybrid plasma flow system was experimentally clarified. Micro-sized water droplets with a low water flow rate were injected into the tail of thermal plasma flow so as not to disturb the plasma flow directly. Injected water droplets were vaporized in the thermal plasma flow and were transported upstream in the plasma flow to the torch by the backflow. After dissociation of water, the production of hydrogen was detected by the optical emission spectroscopy in the downstream RF plasma flow. The emission area of the DC plasma jet expanded and elongated in the vicinity of the RF coils. Additionally, the emission area of RF plasma flow enlarged and was visible as red emission in the downstream RF plasma flow in the vicinity below the RF coils due to hydrogen production. Therefore, the plasma flow mixed with produced hydrogen increased the plasma enthalpy and the highest spheroidization rate of 97% was obtained at a water flow rate of 15?Sml/min and an atomizing gas flow rate of 8?Sl/min using a small power DC-RF hybrid plasma flow system.     

Orientation behavior of carbonaceous mesophase spherules having a new molecular arrangement in a magnetic field

Carbonaceous mesophase spherules of a new-type have been found in the heat-treated products of quinoline-soluble portion of coal-tar pitch containing carbon black. Their spherules have molecular orientation different from that proposed by Brooks and Taylor. The effect of a magnetic field is discussed on the orientation of the spherules formed during carbonization processes using a polarization microscope.     

Two distinct pathways of interleukin-5 synthesis in allergen-specific human T-cell clones are suppressed by glucocorticoids

Glucocorticoids (GC) have long been used as the most effective agents for the treatment of allergic diseases accompanied by eosinophilia such as chronic asthma and atopic dermatitis. The development of chronic eosinophilic inflammation is dependent on interleukin-5 (IL-5), a selective eosinophil-activating factor, produced by helper T cells. To delineate the regulatory mechanisms of human IL-5 synthesis, we established allergen-specific CD4+ T-cell clones from asthmatic patients. GC efficiently suppressed IL-5 synthesis of T-cell clones activated via either T-cell receptor (TCR) or IL-2 receptor (IL-2R). Induction of IL-5 mRNA upon TCR and IL-2R stimulation was totally inhibited by dexamethasone. Human IL-5 promoter/enhancer-luciferase gene construct transfected to T-cell clones was transcribed on either TCR or IL-2R stimulation and was clearly downregulated by dexamethasone, indicating that the approximately 500-bp human IL-5 gene segment located 5' upstream of the coding region contains activation-inducible enhancer elements responsible for the regulation by GC. Electrophoretic mobility shift assay analysis suggested that AP-1 and NF-kappaB are among the possible targets of GC actions on TCR-stimulated T cells. NF-AT and NF-kappaB were not significantly induced by IL-2 stimulation. Our results showing that GC suppressed IL-5 production by human CD4+ T cells activated by two distinct stimuli, TCR and IL-2R stimulation, underscore the efficacy of GC in the treatment of allergic diseases via suppression of T-cell IL-5 synthesis.     

Redundant Control of a Planar Snake Robot with Prismatic Joints

This paper presents a control method of a planar snake robot with prismatic joints. The kinematic model is derived considering velocity constraints caused by passive wheels. The proposed control method based on the model allows the robot to track a target trajectory by appropriately changing its link length using prismatic joints. The degrees of freedom of prismatic joints are represented as kinematic redundancy in the model and are used in realizing subtasks such as singularity avoidance and obstacle avoidance. In addition, the link length is below its limit when introducing a sigmoid function into the kinematic model. Simulations are carried out to demonstrate the effectiveness of the proposed method and show a novel motion that avoids singular configurations through changes in link lengths.

     

Emulsion of polyurethane having thermosetting properties. II. Relation between the mechanical properties of film and the polyurethane structure

A self-emulsifiable polyurethane emulsion having thermosetting property was prepared by the following procedure: the polyurethane–urea–amine was first prepared by the reaction of diethylene–triamine with a prepolymer containing terminal isocyanate groups in a ketone solvent, and then the primary amino group in the polyurethane–urea–amine was reacted with epichlorohydrin. The mixture was neutralized with an aqueous acid, and finally the ketone solvent was removed by distillation in vacuo. In the polyurethane, polytetramethylene glycol (PTMG) was the base polymer functioning as the soft segment. The present paper reports the effects of the following variables on the mechanical properties of the film prepared from the polyurethane emulsion, i.e., the M _n of PTMG, the molar ratio of diethylene–triamine (DTA) to prepolymer containing terminal isocyanate groups, the structure of the isocyanate end group and the molar ratio of tolylene diisocyanate (TDI) with PTMG. The best elastomer property was realized when M_n of PTMG was 2000, TDI/PTMG molar ratio was 2.0, and prepolymer/DTA molar ratio was 0.85.     

Validation of accuracy of enzyme-linked immunosorbent assay in hybridoma screening and proposal of an improved screening method

The 96-well plate format of enzyme-linked immunosorbent assay (ELISA) is the de facto standard in screening hybridomas for active antibody. Despite its widespread use, there have been few or no systematic attempts to validate its accuracy and answer the fundamental question, is it finding all the positives? We report here on a comparison between ELISA and a semiautomated flow-based kinetic exclusion assay (KinExA), both used in screening the same hybridoma cell line. Our finding is that ELISA is both overreporting (false positives) and underreporting (false negatives) compared to the KinExA system. The large number of hybridoma cells (e.g., cultured in six 96-well plates) that must be checked is daunting in considering any method other than ELISA for routine screening. To overcome this, we devised a sampling strategy in which wells are combined in a specified pattern, allowing a significant reduction in the total number of measurements required.