This research focused on the light emission behavior of the OH radical (characteristic spectrum of 306.4nm) that plays a key role in combustion reactions, in order to investigate the influence of the ...residual gas on autoignition. The test engine used was a 2-stroke, air-cooled engine fitted with an exhaust pressure control valve in the exhaust manifold. Raising the exhaust pressure forcibly recirculated more exhaust gas internally. Emission measurements were made under three conditions : normal combustion without any forced application of internal EGR, forced application of light internal EGR and forced application of heavy EGR. When a certain level of internal EGR is forcibly applied, the temperature of the unburned end gas is raised on accout of heat transfer from the hot residual gas and also due to compression by piston motion. As a result, the unburned end gas becomes active and autoignition tends to occur.
HCCI engines have attracted widespread attention as high-efficiency and low-pollution combustion systems. The authors have conducted experiments to visualize rapid combustion in the cylinder ...accompanied by cylinder pressure oscillations and have also investigated the factors influencing rapid combustion in HCCI engines. The results have shown that in combustion accompanied by cylinder pressure oscillations a highly brilliant flame occurs simultaneously over a wide area of the combustion chamber almost instantaneously. It has also been found that the rapidity of HCCI combustion is influenced by the ignition timing and the quantity of heat produced per cycle by the injected fuel.
Artificial biped walking has been invented since epoch of Greek mythology. There are a lot of reasons why human tries to invent a biped walker. For example, they want to have artificial labor or ...comprehend the mechanism of biped walking by synthesizing the artificial biped walker, etc. However the reason might come from a primitive motivation that they just want to make something which achieves what they can always do but what only they do, that is, biped walking. On the other hand, population of young Japanese people who are interested in science tends to decrease recently, and then lots of science (including robotics) education programs has been proposed in order to motivate them. The biped walking is one of attractive topics not only for academia but also for the science education even if it is for primary school children. The purpose of the paper is, hence, to propose a design strategy of three dimensional passive dynamic walker made of cardboard for science and robot education. In order to introduce the walker as a educational program, a precise design method of the walker is provided and is validated through some experiments. Moreover, the program is validated through some class for primary school children and university students.
We present 3 cases with peripheral neuropathies of the median, posterior interosseous, and ulnar nerves associated with rheumatoid synovial cysts of the elbow joint. Magnetic resonance imaging and ...electrophysiological examination led to the final diagnosis of the relation to synovial cysts of the elbow joint. All patients underwent surgical decompression of these nerves and synovectomy of the elbow joint. Functional recovery was excellent in the 2 patients with median and posterior interosseous nerve palsy but incomplete in the patient with ulnar nerve palsy. Such neuropathies require consideration in the differential diagnosis of wrist and hand disability in patients with rheumatoid arthritis. This awareness should enhance early diagnosis and treatment by surgical decompression.
We herein report the very rare case of a 68-year-old Japanese man with multiple jejunal lipomatosis and diverticulosis. He was admitted to our hospital with the chief complaint of melena and anemia. ...A barium study of the small bowel showed multiple lipomatosis and diverticulosis. An approximately 200-cm length of the jejunum was therefore resected. Thereafter, two diverticula and 215 lipomas were recognized in the resected specimen. A pathological examination showed mature adipose tissue with fibrous septa in the submucosal and muscularis propria. These findings were thus suggested to be due to the attenuation of the muscularis propria. The complications of lipomatosis are also discussed.
FDG-PET/CT is a useful method for diagnosing primary unknown carcinoma. Recent reports introduce a new application of this method to evaluate neo-adjuvant chemotherapy response. We here present four ...cases treated in this department with the new application and discuss its advanatges. Four pediatric patient with OS or Ewing were evaluated by FDG-PET. All patients received standard neo-adjuvant chemotherapy. FDG-PET standerd uptake values before (SUV1) and after (SUV2) chemotheraphy were analayzed and correlated with chemotheraphy response assessed by histopathology in surgically excised tumors and by magnetic resonance imaging. It has decreased to SUV2 2.1 and 2.0 (after chemotherapy) from SUV1 3.6, and 5.0 it (before chemotherapy) for osteosarcoma, and decreased to SUV2 1.93 and 0 from SUV1 9.3, and 3.86 in two cases with Ewing sarcoma. The tumor necrosis rate was 90% or over. FDG-PET/CT is a very accurate method for the localization and the malignancy diagnosis of sarcoma. In this study, it also proved useful for the evaluation of chemotherapy response and tumor activity.
We studied electron spin resonance (ESR) in an ordered double perovskite
Ba
2
FeMoO
6
with the Curie temperature
T
C
=
340
K
. The
T-independent gyromagnetic factor at
T
>
T
C
is estimated as
g
∼
2
, ...suggesting that
Fe
3
+
is probed in the paramagnetic resonance. Below
T
C
, the resonance signal shifts to lower fields with broadening of the linewidth. The linewidth increases down to our lowest temperature. Using the two-magnon scattering relaxation mechanism quantitatively reproduces the temperature dependence of the linewidth.
The HCCI engine has attracted for high efficiency and low exhaust emissions. However, the HCCI combustion process has two issues to be resolved : ignition timing control, slower combustion. In order ...to overcome these issues, it is necessary to investigate in detail the low-temperature oxidation reactions that distinctly characterize HCCI combustion and the state of combustion. In this study, spectroscopic measurements were made at a high compression ratio of approximately 15:1, which is sufficiently high for practical operation. Simultaneously, the combustion condition in the cylinder was visualized via a sapphire observation window that was provided in the top of the cylinder head by taking advantage of the simple structure of the two-stroke test engine. The results revealed that the ignition delay period and the manner in which autoignition occurred tended to differ at different compression ratios when EGR was applied, which is believed to be effective in moderating HCCI combustion.
The cellulosic liquefaction fuel (CLF) was made from woods by the direct liquefaction process. Coconuts-oil Methyl Ester (CME) of 5 wt.% was used to mix CLF and diesel fuel, because CLF was not ...completely mixed with diesel fuel. To clarify a desirable CLF fraction for the diesel engine, CLF was divided into two fractions by the distillation: 200 to 250 °C (CLF1) and 250 to 300 °C (CLF2). The weight mixing ratio of CLF in blended fuel was varied until 20 wt.% to analyze ignition characteristics and performance of diesel fuel-CLF-CME blends. The brake thermal efficiency of both CLF mixed fuel was almost equal to diesel fuel, however high NOx was emitted at a high load. This is because the combustion gas temperature was increased by a rapid combustion pressure rise. The smoke concentration of CLF mixed fuel was lower than that of diesel fuel. When CLF1 or CLF2 is mixed with diesel fuel by using 5 wt% of CME and the weight mixing ratio of CLF is up to 20 wt%, CLF mixed fuels have almost no influence on engine performance. For both CLF1 and CLF2 mixed fuel, it is possible to operate diesel engine without any remarkable deterioration of engine performance. When 5 wt.% CLF was mixed to diesel fuel with CME, diesel engine could be continuously operating for 8 hours without any deterioration. The ignition timing of CLF1 mixed fuel was slightly earlier than that of CLF2 at any mixing ratios, therefore CLF1 was suitable for diesel engine.
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