1,169 research outputs found
The Remaining Refractory Thickness Assessment of Hearth Part in the Blast Furnace
In the steel industry, the blast furnace is a process for making molten iron by melting iron ore. The blast furnace body is a huge structure of 50m in height, 20m in width. It should be operated not less than 15 years during one campaign. The structural problems of this blast furnace are cracks of the steel shell and thickness reductions of the stave and the refractory of hearth part caused by wear.
Among them the thickness reduction of the hearth refractory in the blast furnace is very important factor in determining the dismantlement and the reconstruction of the blast furnace. Conventionally, the thermal model was used to estimate the residual thickness and to monitor the temperature of refractory with thermocouples installed on the refractory. Recently, Impact Echo method is being applied to measure the residual thicknesses of concrete or nonmetallic stiff structures.
The method should be accompanied with verification in the actual blast furnace since there are differences in the reflection characteristics of the ultrasonic velocity depending on physical parameters of the steel shell, the refractory and ramming part between the steel shell and the refractory such as the size, the shape, the temperature, the consisting materials and etc. In this study, we compared various sensors such as accelerometer, a microphone and an ultrasonic sensor and the experimental methods in determining the ultrasonic velocity of the anisotropic refractory material.
In addition, measuring refractory thickness of the actual blast furnace was carried out before dismantling and verified with exact thickness of refractory by means of measuring length of the core-boring sample and dismantling investigatio
Thermoelectric properties of graphene incorporated thermoelectric materials
Thermoelectric materials, which can change the waste heat into the usable electricity, are interested in various field of applications such as vehicle, ship, power plane, and so on. To enhance the thermoelectric properties, high electrical conductivity, high Seebeck coefficient, and low thermal conductivity should be conducted, however, the trade-off relation between electronic property and thermal property in terms of carrier concentration could be the bottle-neck on the enhancement of thermoelectric properties of the materials. In this presentation, we discuss with the graphene incorporation in the conventional thermoelectric materials, which could lead to independently control electric and thermal properties
External Use of Propolis for Oral, Skin, and Genital Diseases: A Systematic Review and Meta-Analysis
Objective. The aim of this review is to provide the available evidence on the external use of propolis (EUP) for oral, skin, and genital diseases. Method. We searched twelve electronic databases for relevant studies up to June 2016. Randomized clinical trials (RCTs) were included and analysed. Results. Of the 286 articles identified, twelve potentially relevant studies met our inclusion criteria. A meta-analysis of two studies on recurrent oral aphthae (ROA) indicated that there were no significant differences in total effective rate (TER) for pain disappearance between EUP and placebo groups (RR = 1.96, 95% CI = 0.97–3.98, and P=0.06). In two studies on skin diseases, the combined treatment of EUP with other interventions revealed significant effects on the duration of treatment or TER. In one study on genital diseases, EUP showed significant differences in genital herpes outcome measures compared to placebo. Conclusions. Our results on the effectiveness of EUP for treating oral, skin, and genital diseases are not conclusive because of the low methodological qualities and small sample sizes. Further well-designed randomized controlled trials, with high quality and large samples for specific disorders, must be conducted to obtain firm conclusions
Anti-Apoptotic Effects of SERPIN B3 and B4 via STAT6 Activation in Macrophages after Infection with Toxoplasma gondii
Toxoplasma gondii penetrates all kinds of nucleated eukaryotic cells but modulates host cells differently for its intracellular survival. In a previous study, we found out that serine protease inhibitors B3 and B4 (SERPIN B3/B4 because of their very high homology) were significantly induced in THP-1-derived macrophages infected with T. gondii through activation of STAT6. In this study, to evaluate the effects of the induced SERPIN B3/B4 on the apoptosis of T. gondii-infected THP-1 cells, we designed and tested various small interfering (si-) RNAs of SERPIN B3 or B4 in staurosporine-induced apoptosis of THP-1 cells. Anti-apoptotic characteristics of THP-1 cells after infection with T. gondii disappeared when SERPIN B3/B4 were knock-downed with gene specific si-RNAs transfected into THP-1 cells as detected by the cleaved caspase 3, poly-ADP ribose polymerase and DNA fragmentation. This anti-apoptotic effect was confirmed in SERPIN B3/B4 overexpressed HeLa cells. We also investigated whether inhibition of STAT6 affects the function of SERPIN B3/B4, and vice versa. Inhibition of SERPIN B3/B4 did not influence STAT6 expression but SERPIN B3/B4 expression was inhibited by STAT6 si-RNA transfection, which confirmed that SERPIN B3/B4 was induced under the control of STAT6 activation. These results suggest that T. gondii induces SERPIN B3/B4 expression via STAT6 activation to inhibit the apoptosis of infected THP-1 cells for longer survival of the intracellular parasites themselves
Supreme Court Rulings on Determining the Cartel End Date
Since the very nature of cartels is to operate in ways that are undisclosed and difficult to track, it is often a matter of heated dispute in courts as to when a cartel has ended or been abandoned. Moreover, the cartel duration is a critical issue because it affects not only the level of sanctions imposed, but also the damages amount sought against the cartelists. The Korean Supreme Court has issued several important rulings regarding this matter, but there still remain areas where further guidance and clarification would be beneficial. Thus, this article explores the relevant Korean Supreme Court rulings and concludes that it is time for the highest court to further articulate the legal test for determining the ending date of a cartel in an effort to eliminate legal uncertainty and establish clearer guidance for market participants
Robot-assisted gait training (Lokomat) improves walking function and activity in people with spinal cord injury: a systematic review
Evaluation of the usefulness of three-dimensional optical coherence tomography in a guinea pig model of endolymphatic hydrops induced by surgical obliteration of the endolymphatic duct
Optical coherence tomography (OCT) has advanced significantly over the past two decades and is currently used extensively to monitor the internal structures of organs, particularly in ophthalmology and dermatology. We used ethylenediamine tetra-acetic acid (EDTA) to decalcify the bony walls of the cochlea and investigated the inner structures by deep penetration of light into the cochlear tissue using OCT on a guinea pig model of endolymphatic hydrops (EH), induced by surgical obliteration of the endolymphatic duct. The structural and functional changes associated with EH were identified using OCT and auditory brainstem response tests, respectively. We also evaluated structural alterations in the cochlea using three-dimensional reconstruction of the OCT images, which clearly showed physical changes in the cochlear structures. Furthermore, we found significant anatomical variations in the EH model and conducted graphical analysis by strial atrophy for comparison. The physical changes included damage to and flattening of the organ of Corti-evidence of Reissner's membrane distention-and thinning of the lateral wall. These results indicate that observation of EDTA-decalcified cochlea using OCT is significant in examination of gradual changes in the cochlear structures that are otherwise not depicted by hematoxylin and eosin staining © The Authorsopen0
A Case of Retinal Detachment in Colobomatous Macrophthalmos With Microcornea Syndrome
We report a rare case of retinal detachment in colobomatous macrophthalmos with microcornea syndrome. A 25-year-old female who had suffered from poor vision in her left eye since early childhood and high myopia in her right eye (-11 D) visited our clinic because of a sudden deterioration of vision. Examination of the anterior segment showed microcornea with coloboma of the inferior pupil margin in the left iris. Fundus examination of the left eye revealed an inferior choroidal coloboma extending from the optic disc and macula. The patient also had total bullous retinal detachment. Pars plana vitrectomy with silicone oil tamponade was performed, and the retina was reattached. In the very rare condition of colobomatous macropthalmos with microcornea, retinal detachment may develop. Pars plana vitrectomy with additional silicone oil tamponade may be performed to treat this condition
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