ObjectivePanic disorder has been suggested to be divided into the respiratory and non-respiratory subtypes in terms of its clinical presentations. The present study aimed to investigate whether there are any differences in treatment response and clinical characteristics between the respiratory and non-respiratory subtypes of panic disorder patients.MethodsAmong the 48 patients those who completed the study, 25 panic disorder patients were classified as the respiratory subtype, whereas 23 panic disorder patients were classified as the non-respiratory subtype. All patients were treated with escitalopram or paroxetine for 12 weeks. We measured clinical and psychological characteristics before and after pharmacotherapy using the Panic Disorder Severity Scale (PDSS), Albany Panic and Phobic Questionnaire (APPQ), Anxiety Sensitivity Index-Revised (ASI-R), State-Trait Anxiety Inventory (STAI-T, STAI-S), Hamilton Anxiety Rating Scale (HAM-A), and Hamilton Depression Rating Scale (HAM-D).ResultsThe prevalence of the agoraphobia was significantly higher in the respiratory group than the non-respiratory group although there were no differences in gender and medication between the two groups. The respiratory group showed higher scores on the fear of respiratory symptoms of the ASI-R. In addition, after pharmacotherapy, the respiratory group showed more improvement in panic symptoms than the non-respiratory group.ConclusionPanic disorder patients with the respiratory subtype showed more severe clinical presentations, but a greater treatment response to SSRIs than those with non-respiratory subtype. Thus, classification of panic disorder patients as respiratory and non-respiratory subtypes may be useful to predict clinical course and treatment response to SSRIs.

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A methanol steam reformer converts methanol and steam into a hydrogen-rich mixture through an endothermic reaction. The methanol reformer is divided into a reaction section and a heat supply section that transfers thermal energy from 200 to 300 °C. This study presents the behavior of the methanol steam reforming reaction using the latent heat of the steam. A numerical analysis was separately conducted for two different regimes assuming constant heat flux conditions. A methanol steam reformer is an annulus structure that has a phase change heat transfer from an outer tube to an inner tube. Different from the steam zone temperature in the tube, the latent heat of steam condensation decreases, and there is a gradual between-wall temperature decrease along the longitudinal direction. Since the latent heat of steam condensation is very sensitive to the requested heat from the reformer, it is necessary to consider a refined design of a methanol reformer to obtain a large enough amount of heat by steam condensation.

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A methanol steam reformer converts methanol and steam into a hydrogen-rich mixture through an endothermic reaction. The methanol reformer is divided into a reaction section and a heat supply section that transfers thermal energy from 200 to 300 °C. This study presents the behavior of the methanol steam reforming reaction using the latent heat of the steam. A numerical analysis was separately conducted for two different regimes assuming constant heat flux conditions. A methanol steam reformer is an annulus structure that has a phase change heat transfer from an outer tube to an inner tube. Different from the steam zone temperature in the tube, the latent heat of steam condensation decreases, and there is a gradual between-wall temperature decrease along the longitudinal direction. Since the latent heat of steam condensation is very sensitive to the requested heat from the reformer, it is necessary to consider a refined design of a methanol reformer to obtain a large enough amount of heat by steam condensation.

In a stationary fuel cell system, secondary reformer is utilized to enhance system efficiency. Since the heat sources of stationary fuel cell has low temperature, the operation philosophy of secondary reformer has to be differed from high temperature reformer. Researches on methane steam reformers have been made in various directions, but most have been done only in high efficiency systems. In this study, the design of the steam reformer with the low temperature gas as the heat source would be improved and the temperature distribution would be improved. To do this, computational analysis was carried out. Through computational analysis, we tried to improve radial flow uniformity and temperature distribution of methane and water vapor mixture in the reformer. In order to improve the flow and temperature distribution inside the reformer, the analysis was carried out considering the presence of the spiral vortex generator, the shape of the perforated plate, and the baffle. As a result, the uniformity of the flow was increased by installing the spiral vortex generator, and it was confirmed that the average temperature was increased by installing the perforated plate and the baffles. And an endothermic chemical reaction inside the reaction part and investigated the reforming characteristics according to the temperature and s/c ratio in order to consider the chemical reaction side with the improved structure in the flow side. The s/c ratio was set to 2 and 3, and the temperature was set to 1000K and 1100K. As a result, it has been concluded that the modification of the reforming reaction depends on the temperature and s/c ratio, and additional structural improvement is required.

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