High On/Off Ratio ( 12dB ) and Responsivity ( 300 A/W ) in Integrated Optically Controlled HEMT

Takayuki Sakai,Yasuhiro Takesue,Kazuhiko Shimomura 한국통신학회 1997 OPTOELECTRONICS & COMMUNICATIONS CONFERENCE Vol.2 No.1

Influencing factor on acid gas removal and flow characteristics of slaked lime in onsite production process

( Ln-hee Hwang ),( Yutaro Sakai ),( Takayuki Matsuo ),( Yasumasa Tojo ),( Toshihiko Matsuto ) 한국폐기물자원순환학회(구 한국폐기물학회) 2018 한국폐기물자원순환학회 심포지움 Vol.2018 No.1

Slaked lime is commonly used as alkali agent for dry scrubbing of acidic gases such as hydrogen chloride and sulfur oxide in flue gas discharged from municipal solid waste incinerator (MSWIs). As the utilization amount of slake lime is the most among chemicals used in MSWI, its influence on the cost of flue gas treatment is significant. In our previous research, the on-site production condition of slaked lime using low cost quicklime was examined to develop a hydrator installed in MSWL As the result, slaked lime with same acid gas removal performance as commercial one was obtained. However, when the produced slaked lime was stored in a hopper and supplied with a feeder, the amount of adhesion on the wall surface was increased, which led to the problem that the quantitative supply to duct became impossible. Thus, the improvement of flow properties of the produced slaked lime was required. The aim of this research was to clarify the effect of the production conditions on the acid gas removal rate and the flow property of slaked lime and to find production conditions that both acidic gas removal performance and flow property become equal to or higher than commercial slaked lime. For this purpose, the molar ratio of distilled water to quicklime (MR=2.0 and 2.5), stirring rate (10~40rpm), residence time (30~60min) of hydration process, etc. were examined using a lab-scale of hydrator. Hydration rate, water content, hydrogen chloride removal rate, particle size distribution, specific surface are/pore volume, angle of repose, and <Uscharge rate of slake lime from circular orifice were measured to evaluate produced slaked lime. Residence time of quicklime varied by the angle of paddle (5~20°) in hydrator. Since the hydration rate was constant at 97% or more at the retention time of 46 min, the operation was performed with the paddle angle fixed at 10。. The water content of slaked lime produced at MR=2.5 was higher but it was decreased to the same level of slaked lime produced at MR=2.0 when the stirring rate was increased to 40 rpm. The water content of slaked lime obtained at MR = 2.0 was barely changed regardless of stirring rate. The angle of repose was high at MR=2.5, indicating that the flow property was comparatively poor. The discharge rate of the slaked lime produced at MR=2.5 was relatively slow too. It was considered that the flow property of slaked lime deteriorated as the amount of water added to quicklime increased. The variation of the removal rate of hydro gen chloride depending on stirring rate and MR was small. Slaked lime with hydrogen chloride removal performance equivalent to commercial one was obtained under the production condition tested in this work. It was suggested that slaked lime can be obtained at MR=2.0 and stirring rate=10 or 20 rpm, which has the same acid gas removal performance and flow property as commercial slaked lime.

천연가스자동차 촉매의 온도분포 및 배기정화 특성

최병철,김영길,Choe, Byeong-Cheol,Kim, Yeong-Gil,Sakai, Takayuki 대한기계학회 1998 大韓機械學會論文集B Vol.22 No.2

Experiments were conducted to investigate the temperature profile and the emissions conversion efficiency of catalytic converters for natural gas vehicles. Two types of the catalyst structure and several transient engine operating conditions were used. The dual-bed catalyst effectively reduced the emissions in a transient period due to the low heat capacity of the front bed. The lanthanoid additives were effective in improving catalyst durability. When the natural gas fueled engine were operated outside of a very narrow window of excess air ratio (from 0.993 to 1.004), the HC and NOx conversion efficiency dropped off. The drop-off were especially fast on the lean side of the window.

Usefulness of Simultaneous Magnetic Resonance Neurography and Apparent T2 Mapping for the Diagnosis of Cervical Radiculopathy

Enomoto Keigo,Eguchi Yawara,Sato Takashi,Norimoto Masaki,Inoue Masahiro,Watanabe Atsuya,Sakai Takayuki,Yoneyama Masami,Aoki Yasuchika,Orita Sumihisa,Narita Miyako,Inage Kazuhide,Shiga Yasuhiro,Umimura 대한척추외과학회 2022 Asian Spine Journal Vol.16 No.1

Study Design: Retrospective observational study.Purpose: We investigated the correlation between T2 relaxation times and clinical symptoms in patients with cervical radiculopathy caused by cervical disk herniation.Overview of Literature: There are currently no imaging modalities that can assess the affected cervical nerve roots quantitatively.Methods: A total of 14 patients with unilateral radicular symptoms and five healthy subjects were subjected to simultaneous apparent T2 mapping and neurography with nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation enhancement signaling (SHINKEI-Quant) using a 3-Tesla magnetic resonance imaging. The Visual Analog Scale (VAS) score for neck pain and upper arm pain was used to evaluate clinical symptoms. T2 relaxation times of the cervical dorsal root ganglia of the brachial plexus were measured bilaterally from C4 to C8 in patients with radicular symptoms and from C5 to C8 in healthy controls. The T2 ratio was calculated as the affected side to unaffected side.Results: When comparing nerve roots bilaterally at each spinal level, no significant differences in T2 relaxation times were found between patients and healthy subjects. However, T2 relaxation times of nerve roots in the patients with unilateral radicular symptoms were significantly prolonged on the involved side compared with the uninvolved side (p<0.05). The VAS score for upper arm pain was not significantly correlated with the T2 relaxation times, but was positively correlated with the T2 ratio.Conclusions: In patients with cervical radiculopathy, the SHINKEI-Quant technique can be used to quantitatively evaluate the compressed cervical nerve roots. The VAS score for upper arm pain was positively correlated with the T2 ratio. This suggests that the SHINKEI-Quant is a potential tool for the diagnosis of cervical nerve entrapment.

Performance of Lithium-Ion Battery with Tin-Phosphate Glass Anode and Its Characteristics

Yamauchi, Hideo,Park, Gumjae,Nagakane, Tomohiro,Honma, Tsuyoshi,Komatsu, Takayuki,Sakai, Tetsuo,Sakamoto, Akihiko The Electrochemical Society 2013 Journal of the Electrochemical Society Vol.160 No.10

<P>The performance of a lithium-ion battery (LiB) fabricated with a tin-phosphate glass anode was studied as well as the characteristics of the anode. It was confirmed that the total positive charge of Sn<SUP>2+</SUP> ions in the glass anode is compensated by a reaction with lithium during the first charge by forming tin crystals. It was observed after the first charge that the glass is converted into a nanocomposite in which the metallic crystals are embedded in an amorphous lithium phosphate matrix. A half-cell fabricated with the glass anode showed a reproducible capacity of 550 mAh/g at room temperature, which was much higher than that of the cell with a graphite anode. The cell also showed a steady capacity of 160 mAh/g even at −20°C with no deposition of lithium dendrites. A full-cell fabricated with the glass anode and LiMn<SUB>2</SUB>O<SUB>4</SUB> cathode showed a good life cycle performance at 60°C along with no degradation in its life cycle performance. The tin-phosphate glass is a promising candidate as a new anode material that realizes LiBs with a high energy density that can be used over a wide temperature range.</P>

The Prevalence and Characteristics of Symptomatic Uncomplicated Diverticular Disease Among Asian Patients With Unexplained Abdominal Symptoms

Tsumugi Jono,Yuki Kasai,Takaomi Kessoku,Tomoki Ogata,Kosuke Tanaka,Takayuki Kato,Eiji Sakai,Takeo Kurihashi,Machiko Nakatogawa,Shunsuke Oyamada,Seiji Futagami,Kok-Ann Gwee,Atsushi Nakajima 대한소화기 기능성질환∙운동학회 2024 Journal of Neurogastroenterology and Motility (JNM Vol.30 No.1

Background/AimsThe precise incidence of symptomatic uncomplicated diverticular disease (SUDD) and its effects on the quality of life (QOL) remain unclear, particularly in Asian patients with right-sided SUDD. We assess the prevalence of SUDD and its impact on QOL in a real-world population. MethodsFive institutional cohorts of patients who received outpatient treatment for unexplained abdominal symptoms from January 15, 2020 to March 31, 2022, were included. All patients underwent colonoscopy. SUDD was defined as the presence of recurrent abdominal symptoms, particularly pain in the lower right or left quadrant lasting > 24 hours in patients with diverticulosis at the site of pain. The 36-item short-form health survey was used to assess QOL. ResultsDiverticula were identified in 108 of 361 patients. Among these 108 patients, 31% had SUDD, which was right-sided in 39% of cases. Of the 50 patients with right-sided diverticula, 36% had SUDD, as did 15 of 35 patients with left-sided diverticula (43%). Among the 33 patients with SUDD, diverticula were right-sided, left-sided, and bilateral in 39%, 45%, and 15% of patients, respectively. Diarrhea was more frequent in the SUDD group than in the non-SUDD group. Patients with SUDD had significantly lower physical, mental, and role/social component scores than those without SUDD. ConclusionsIt is important to recognize that patients with SUDD account for as high as 31% of outpatients with unexplained abdominal symptoms; these patients have diarrhea and a low QOL. The presence of right-sided SUDD was characteristic of Asian patients.