Search

The purposes of this study were to report the surgical success rate of scleral buckling surgery (SB) for rhegmatogenous retinal detachment (RRD) in a single academic hospital, analyze the incidence of cystoid macular edema (CME) after SB using optical coherence tomography (OCT), and reveal the factors associated with the development of CME. This was a retrospective observational study of patients with RRD who underwent SB from 2010 to 2020 in a single academic hospital. The anatomical success was initially achieved in 267 of 288 eyes (92.7%), and finally achieved in 288 eyes (100%). After excluding 17 eyes that underwent vitrectomy for reoperations, a total of 271 eyes of 267 patients (173 men; age, 43.5 ± 16.9 years) were retrospectively analyzed to evaluate the incidence of postoperative CME. CME occurred in 6 of 271 eyes (2.2%) within 3 months after initial surgery. Pseudophakic and aphakic eyes appeared more likely to develop CME (chi-squared test: p = 0.0078). Five of the six cases with postoperative CME were able to be medically treated. Scleral buckling surgery showed a high success rate even in the era of small-gauge vitreous surgery, and the postoperative frequency of CME after SB was low (2.2%). Previous cataract surgery may be associated with the development of postoperative CME, which is mostly medically manageable.

Xentuzumab is an insulin-like growth factor (IGF) ligand-neutralizing antibody. This phase 1 trial assessed xentuzumab in Japanese patients with solid tumors. Patients aged ≥20 y old with solid tumors that were refractory or not amenable to standard therapy were enrolled. Patients received xentuzumab intravenously at a starting dose of 750 mg/wk. Dose escalation used a 3 + 3 design with dose de-escalation. The primary endpoint was to determine the maximum tolerated dose (MTD) of xentuzumab. Safety, pharmacokinetics, pharmacodynamics, and anti-tumor activity were also assessed. Fifteen patients received xentuzumab in the dose escalation part (750 mg/wk [n = 6]; 1000 mg/wk [n = 3]; 1400 mg/wk [n = 6]). There were no dose-limiting toxicities at any dose; the MTD of xentuzumab was not reached. Xentuzumab 1000 mg/wk was recommended as the relevant biological dose. Six further patients received xentuzumab 1000 mg/wk in an expansion cohort. Of 21 patients, 13 (61.9%) experienced a drug-related adverse event, most commonly fatigue (23.8%), neutropenia (19.0%), diarrhea, nausea, white blood cell count decrease, and muscle spasms (14.3% each). No relevant deviations from dose linearity of xentuzumab exposure were observed during dose escalation. Total IGF-1 and IGF-2 levels increased and bioactive IGF levels decreased from baseline to 24 h after the first infusion in cycle 1. Partial response was observed in 2 (9.5%) patients with desmoid-type fibromatosis. Disease control was achieved in 6 (28.6%) patients (median duration 42.4 mo). Xentuzumab monotherapy was well tolerated in Japanese patients and showed evidence of anti-tumor activity. This study was registered with www.clinicaltrials.gov (NCT02145741).

Mismatch of power supply integrity of power delivery network (PDN) between an automatic test equipment (ATE) and a customer board can lead to test failures such as overkills or underkills during semiconductor test. This paper proposes a technique to control the power supply impedance on an ATE using compensation current injection so that it emulates the impedance on a customer board. Digital filter is used to calculate compensation current waveform in real time in response to the measured power supply voltage fluctuation. Its implementation is based on the PDNs of both the ATE and the customer board. This paper introduces the filter implementation methodology for arbitrary PDN using nested-feedback loop of digital filter, as well as experimental results of prototype circuits. This paper demonstrates that with the proposed current injection the power supply voltage fluctuation waveform on the ATE matches up with that on the customer board, which means that the compensation current injection successfully controls and emulates the impedance. With the proposed technique test failures caused by the impedance difference between the two environments are reduced.

PurposeTo determine the correlation of the degree of aniseikonia with the retinal displacements and metamorphopsia in patients that have undergone successful epiretinal membrane (ERM) surgery.MethodsSubjects were 28 eyes with an ERM in 28 patients. The New Aniseikonia Test (NAT) and M-CHARTS were used to quantify the degree of preoperative and postoperative aniseikonia and metamorphopsia. We also evaluated the distance between the intersections of 2 sets of retinal vessels situated vertically or horizontally by using spectral-domain optical coherence tomography (SD-OCT) images in 28 patients.ResultsThe vertical score of M-CHARTS (MV) was not significantly improved, but the horizontal score of M-CHARTS (MH) was significantly improved at 1 week, 1 month, and 3 months postoperatively. The preoperative NAT score was significantly correlated with the preoperative MH. The NAT score at 3 months was significantly correlated with the MH at 3 months and the MV at 3 months. The preoperative NAT score was significantly correlated with the ratio of the vertical retinal displacement at 1 month and at 3 months after surgery. However, the NAT scores did not improve significantly at any postoperative times.ConclusionsThe degree of aniseikonia was significantly correlated with the degree of metamorphopsia and the tangential displacement of the retina after ERM surgery. Aniseikonia is difficult to improve and metamorphopsia may be a more sensitive parameter to detect the functional recovery after successful ERM surgery.

Regular diagnosis of the structural health of infrastructure, such as bridges, is indispensable to ensure safety and reliable operation of the society. Non-destructive tests based on X-ray imaging are powerful tools to inspect the inside of a concrete structure in detail. Establishing a diagnostic method of bridges based on X-ray visualization is required to examine the internal conditions and helps in the rationalization of maintenances. We demonstrated our 950 keV X-band electron linac based X-ray source for on-site actual bridge inspection and visualized the inner structure of a bottom floor slab. For the more precise inspection of the conditions of wires and rods, we applied three-dimensional image reconstruction methods for bridge mock-up samples. Partial angle computed tomography and tomosynthesis gave cross section images of the samples with 1 mm resolution. We are planning to investigate another part of the bridge, with the 950 keV X-ray system in the near future.

Neutrons have the power to penetrate metals or heavy elements such as calcium, silicon, and iron. Neutrons also have high sensitivity, so they can be used to detect elements such as boron and chlorine. An accelerator-driven, compact neutron system has been developed in RIKEN for practical use on job sites.In this paper, a pixel imaging detector for fast neutrons with energy levels above 1 MeV is developed and used to produce images of an iron rod and air pockets through 30 cm of concrete. Also, the salt concentrations of 4 cm- and 5 cm-thick mortar blocks are measured, and a correlation diagram is obtained for up to 1 kg/m3.

This paper proposes a power integrity control technique for dynamically controlling power supply voltage fluctuations for a device under test (DUT), and demonstrates its effectiveness for eliminating the overkills/underkills due to the difference of power supply impedance between an automatic test equipment (ATE) and a practical operating environment of the DUT. The proposed method injects compensation currents into the power supply nodes on the ATE system in a feed-forward manner such that the ATE power supply waveform matches with the one on the customer's operating environment of the DUT. A method for calculating the compensation current is also described. Experimental results show that the proposed method can emulate the power supply voltage waveform under a customer's operating condition and eliminate 95 % of overkills/underkills in the maximum operating frequency testing with 105 real silicon devices. Limitations and applications of the proposed method are also discussed.

AIM: To determine the relationship between the subfoveal choroidal thickness (CT) and intraocular pressure (IOP) following idiopathic epiretinal membrane (ERM) surgery. METHODS: Retrospective observational case series of patients who had undergone 23-gauge vitrectomy for an ERM. The measurements of CT and IOP were done at the baseline and 1d, 1wk, 1, 3, 6, and 12mo after the surgery. RESULTS: Forty-four eyes of 43 patients with a mean age of 69.8±9.5y were studied. The CT was 200.8±86.3 µm at the baseline, 210.1±83.5 µm at 1d, 213.2±85.4 µm at 1wk, 203.1±84.0 µm at 1mo, 197.5±85.5 µm at 3mo, 197.7±84.0 µm at 6mo, and 191.2±86.8 µm at 12mo after surgery. The CT on day 1 and week 1 after the surgery was significantly thicker than that at the baseline CT (P=0.0023 and P

This paper reviews the recent activities for normally-off GaN-based gate injection transistors (GITs) on Si substrates and their application to inverters. Epitaxial growth of the AlGaN/GaN heterostructures with good crystallinity over 200-mm Si substrates with eliminated bowing enables low-cost fabrication of GaN devices with high breakdown voltages. A novel normally-off GaN transistor called as GIT is proposed in which hole injection from the p-type AlGaN gate increases the drain current with low on-state resistance by conductivity modulation. The low on-state resistance in GaN-based devices greatly helps to increase the efficiency of power switching systems. A GaN-based three-phase inverter successfully drives a motor with high efficiency of 99.3% at a high output power of 1500 W. The presented GaN-based devices are expected to greatly help saving energy in the future as an indispensable power switching system.

DME HCCI기관의 단점은 디젤 엔진에 비해 기관부하 영역이 굉장히 좁다는 것이고 이는 저온산화반응이 너무 빨리 일어나서 노크를 발생시키기 때문이다. 저온산화반응을 억제하기 위해서 DME 연소에 미치는 천연가스의 영향을 실험한 결과, 천연가스가 DME의 저온산화반응을 억제시키기 때문에 기관부하영역이 확대된다는 것을 알았다. 본 연구에서는 서로 다른 세탄가를 가진 첨가연료가 DME 저온산화반응에 미치는 영향을 실험적으로 조사하였다. 그 결과 저온산화반응의 최고 열발생율은 세탄가에 의존하지 않지만 착화온도는 세탄가에 의존한다는 사실을 밝혔다.

According to the previous experimental works on the low solidity circular cascade diffuser (LSD), a pressure recovery of a centrifugal blower was improved by the LSD significantly in a wide range of flow rate, and the pressure recovery was improved further by the LSD with a tandem cascade in comparison with the LSD with a single- row cascade. In the present study, the flow behavior in the LSD with the tandem cascade has been analyzed numerically by using the commercial CFD code of ANSYS-CFX12. It was shown clearly that the higher pressure recovery was achieved by applying the LSD with the tandem cascade, and the high pressure recovery is based on the high pressure rise in the vaneless space upstream of the LSD and the high blade loading of the front blade of the LSD. The high pressure recovery in the LSD could be achieved by controlling the flow separation on the suction surface of the front blade and also on that of the rear blade due to formation of the favorable secondary flow and due to increase in mass flow passing through the slit section between the front and rear blades., Journal of Thermal Science, 21(4), pp.384-390; 2012

A laser 2-focus velocimeter (L2F) has been applied for measurements of velocity and size of droplets in the dense region of diesel fuel spray under the atmospheric pressure condition. The fuel mass distribution in the spray obtained by the measurement was compared with the one simulated by using 3D-CFD code KIVA-3V. The radial velocity of spray droplets near the injector nozzle in the KIVA-3V code was changed to reproduce the measured fuel mass distribution. The combustion simulations of tetradecane (C14H30) and Et20, which consists of 80% tetradecane and 20% ethanol by mass, were conducted by using both original and modified KIVA-3V codes. It was found that the simulation results of heat release rate and ignition delay period remained almost unchanged even though the mass distribution was changed. However, the predicted amount of soot formation simulated by using original KIVA-3V code was different from that simulated by using modified KIVA-3V code in both of tetradecane and Et20 combustion simulations., 1st International Conference on Renewable Energy Research and Applications, ICRERA 2012; Nagasaki; Japan; 11 November 2012 ～ 14 November 2012, Renewable Energy Research and Applications (ICRERA), 2012 International Conference on, Article number 6477397; 2012

A laser 2-focus velocimeter (L2F) has been applied for measurements of velocity and size of droplets in the dense region of diesel spray. Investigated was the fuel spray injected intermittently into the atmosphere from an injector nozzle with the orifice diameter of 0.113 mm. The injection pressure was set at 40 MPa by using a common rail system. The L2F had a micro-scale measuring volume which consisted of two foci. The focal diameter was about 3 μm, and the distance between two foci was 17 μm. The maximum data sampling rate of the L2F system was markedly high as 15 MHz. Measurement was conducted at 25 mm downstream from the nozzle. The local mass flow rate and the number density were calculated at several specified times from the measured velocity, size, and arrival time of droplets. It was clearly shown that the mass flow rate was higher at the spray front than the inside, and was higher at the spray center than the periphery. The accumulated mass flow rate in the spray section measured by the L2F was almost equal to the amount of injected fuel mass within 5%.

We have developed a new production method for silica sols using a Y-shaped reactor. Diluted sodium silicate and sulfuric acid were forced to collide against each other at the intersection of the reactor. Silica sols with the appropriate viscosity produced by this method could be used as waste water treatment agents and retention aids for papermaking. In this study, the gelation process of silica sols was considered by dynamic viscoelastic measurements. Furthermore, we observed directly observed the gel surface using a scanning probe microscope (SPM). From the results, the onset time of gelling was strongly affected by both the concentration of SiO2 and the excessive rate of sulfuric acid. The gel surface structure produced with different conditions was also characterized. It was found that larger coalescence of silica particles presented in gels and the coalescence rate depended on the excessive rate of sulfuric acid.

A high-pressure ratio and a wide operating range are highly required for a turbocharger in diesel engines. Ring groove arrangement is effective for flow range enhancement of centrifugal compressors. Two ring grooves on the suction pipe and the shroud casing wall are connected by means of the annular passage, and the stable recirculation flow is formed at small flow rates from the downstream groove toward the upstream groove through the annular bypass. It is well known that the ring groove arrangement shows the following two merits; (1) the formation of recirculation flow removes the low energy fluid around the downstream groove located near the splitter blade leading edge, (2) the flow incidence can be reduced because the recirculation flow merges again with the incoming main flow upstream of the impeller inlet. In the present study, the ring groove arrangement was applied to the high speed centrifugal compressor, in addition, in order to suppress too large pre-whirl due to the recirculation flow, the effects of guide vane installed in the annular passage and the ring groove configuration on the pre-whirl were analyzed numerically. The numerical flow analysis was carried out by using the commercial code produced by ANSYS-CFX. The simulation results show the multi-ring grooves are fairly effective in combination with the suitable configuration of guide vanes for improvement in the inlet velocity distortion., THE 10TH ASIAN INTERNATIONAL CONFERENCE ON FLUID MACHINERY : Kuala Lumpur (Malaysia), 21–23 October 2009, AIP Conference Proceedings, 1225, pp.47-54; 2010

This paper deals with the effect of the blade tip-groove of the low solidity cascade diffuser (LSD) on the blower characteristic and the noise generated by the LSD. The small grooves were set up at the root and/or tip near the leading edge of the LSD blade. In order to clarify the mechanism of noise increase due to LSD and also to reduce the noise, the relationships between the noise increase based on the LSD, the LSD performance and the secondary flow formed additionally by the tip-groove were investigated experimentally as well as numerically, especially analyzing flow behaviors in the LSD in view points of flow separation on the suction surface of the LSD blade and the secondary flow on the side walls. By reducing the stagnation region smaller near the root and/or tip of the LSD blade leading edge, the secondary flow behavior changes remarkably around the LSD blade, as a result, the noise level and the blower characteristics vary. It can be concluded that, by means of a small tip-groove located only at the shroud side near the LSD blade leading edge, the noise generated by the LSD can be reduced without deteriorations of the LSD performance and the blower characteristics as well., Journal of Thermal Science, 18(4), pp.321-324; 2009

Field investigations at the Sendai River mouth in Tottori Prefecture were carried out in order to clarify characteristics of bottom topographical changes. Sounding surveys were carried out from Sept. 2004 to Oct. 2006. Morphodynamics around the Sendai River mouth were discussed using the results of the surveys. It was found that a sand bar due to wave action in winter season was formed in the river mouth and then the sand bar was flushed by a flood in rainy season or a typhoon. The amount of deposited and eroded sediments in the river mouth was also estimated. Furthermore, a numerical analysis was carried out using 3D morphodynamic model in order to clarify a qualitative relation among river discharges, wave conditions and morphodynamics.

Phase transition of BaNd 2 Mn 2 O 7 from orthorhombic (space group Fmmm ) to tetragonal phase ( I 4/ mmm ) was studied by high temperature powder X-ray diffractometry and Rietveld analysis. The transition temperature was identified at 523 K, which is almost the same transition temperature as the compounds with other rare earth ions in this BaLn 2 Mn 2 O 7 family (Ln = Sm and Eu) with Fmmm space group. During the transition an oxygen octahedron of each phase changes a little its form, in which four oxygen atoms perpendicular to c -axis make a rectangle and a square for orthorhombic and tetragonal phases, respectively. Manganese ion is not on the center of the quadrilateral consisting of these four oxygen ions, but a little apart from the center along c -axis in both phases.

The objectives of the present study is to clarify ignition characteristics, the combustion process, the knock limit and the misfire limit of natural gas mixed with a small amount of dimethyl ether (DME) in a HCCI engine. In the combustion test, natural gas and a small amount of DME were charged into the suction air homogeneously. The equivalence ratio of natural gas was increased to find the knock limit or the misfire limit of the HCCI test engine under a constant DME amount. The effect of the natural gas addition on suppression of the low temperature reaction of DME, and the effects of the DME amount and the intake temperature on the reaction rates, the knock limit of the DME/natural gas mixture, and the operation load range of the HCCI engine were investigated experimentally.

本論文は, 将来の道路橋基礎への部分安全係数設計法の導入に向け, 地盤定数の特性値の評価, 設計書式について議論したものである. 地盤定数の評価は基礎設計において最も重要な点のひとつであるが, その信頼性は設計の過程で用いられる地盤調査法に強く依存する. したがって, 異なる基礎構造物間においてある一定の構造信頼性を保持するためには地盤パラメータの特性値の評価に関して一定の手順を定めておくことが不可欠である. 本論文は, まず構造物基礎の部分安全係数設計法の書式として材料係数アプローチと抵抗係数アプローチのいずれを採用すべきかについて考察する. 次に地盤調査結果から地盤パラメータの特性値を決定するための共通の手順を提案する.

Three dimensional flow separation occurring in a vaneless diffuser at small flow rates was analyzed by using the numerical simulation with the low Reynolds-number turbulence model (LRN k-e) as well as the momentum integral method (MI). Comparison between the LRN k-e calculation and the experiment indicates quite a good agreement in the 3-D boundary layer velocity profile. The numerical investigation shows that the LRN k-ecalculation can predict the reverse flow in the vaneless diffuser, while the MI-method behaves relatively poor although it captures the overall flow pattern correctly. It is clarified that a small gradient in the inlet tangential velocity distribution with respect to the diffuser depth is the key factor which dominates the reverse flow behavior in the vaneless diffuser at small flow rates, as demonstrated in the experiment.

In order to reduce NOx and smoke simultaneously and also to improve markedly the trade-off between smoke and NOx without deteriorating fuel consumption, natural gas was charged homogeneously into the intake air and was burned igniting by a small amount of gas oil injection in a four cylinder naturally-aspirated DI diesel engine. Combustion tests were carried out by changing the ratio of the amount of natural gas and the amount of gas oil first, secondarily the intake preheating temperature, and thirdly the EGR rate respectively. Effects of the respective parameter on the ignition and the burning rate of natural gas, exhaust emissions and specific fuel consumption were clarified experimentally. It is found that significant improvement of smoke-NOx trade-off can be obtained without deteriorating fuel consumption by the suitable combination between the natural gas charge rate, the intake preheating temperature and the EGR rate for each engine load condition.

This paper presents a new method for measuring random timing jitter or sinusoidal timing jitter in signals of telecommunication devices. The method uses a divide-by-M circuit to reduce the frequency and the number of clock samples, and applies the Hilbert transform to measure the timing jitter. This new frequency division method is validated with experimental data from a serializer-deserializer device and a modulated signal source generating a 2.5 GHz FM signal.

Purpose : Because of the shape of mandibular complete dentures, stress is the greatest along the midline. These dentures frequently fracture at or near this area. In order to contribute to the database of information available to dental professionals, the present study was undertaken to evaluate the distribution of stress and the fracture strength of denture bases, both before and after repair of a midline fracture.Materials and Methods : Twelve denture bases (each 3 mm thick) were constructed of polymethyl methacrylate acrylic resin. The stress pattern of each base was characterized by measuring changes in thermal emission from the surface of the denture base. The fracture strength of six of the bases was measured by bending them with a compression-bending tester until they fractured.Results : Stress concentration along the midline of the denture bases was observed. The mean fracture strengths of unbroken bases, repaired bases, and bases repaired with both resin and wire were 9.36, 2.28, and 4.34 N, respectively.Conclusion : Greater stress was observed along the midline in bases repaired with autopolymerizing resin only than in unbroken bases. In addition, the fracture strength of the repaired bases was only about 1/4 that of unbroken bases. It was observed that stress was less concentrated along the midline of bases repaired with autopolymerizing resin and a reinforcement wire compared to either repaired bases or unbroken bases.

The existing non-destructive inspection method employed for concrete structures uses high energy X-rays to detect internal flaws in concrete structures and iron reinforcing rods. In addition to this conventional method, the authors are developing an innovative inspection system that uses a mobile compact linac-driven neutron source that utilizes neutron backscattering, to measure the moisture distribution in concrete structures and estimate the corrosion probability distribution of iron reinforcing rods.

The authors have proposed a new technique to suppress successfully the rotating stall in the vaneless diffuser. By positioning the completely rough wall between R=1.2 and 1.6 on the hub side diffuser wall alone, the flow rate of rotating stall inception was decreased by 42% at a small pressure drop less than 1% of the blower pressure rise. This is based on that the local reverse flow occurs firstly at the hub side in most centrifugal blowers with backswept blade impeller mainly depending on the distortion of tangential component of inlet main-flow velocity. The 3-D boundary layer calculation shows that the local reverse flow is decreased remarkably by an increase in wall friction, and it disappears if the friction coefficient is 0.01 about twice of the smooth wall. By analyzing the effect of wall friction and turbulence induced by the rough wall, it is clearly shown that the rough wall positioned in the limited region, where the wall-limiting streamline flow angle shows the negative maximum, is quite effective to suppress the rotating stall at a small drop of the diffuser pressure recovery.