Search

Your search keyword '"Kawahara N"' showing total 192 results
Start Over Author "Kawahara N" Search Limiters Peer Reviewed
192 results on '"Kawahara N"'

3. Surgery for metastatic spine tumors in the elderly. Advanced age is not a contraindication to surgery!

Author

Amelot, A., Balabaud, L., Choi, D., Fox, Z., Crockard, H.A., Albert, T., Arts, C.M., Buchowski, J.M., Bunger, C., Chung, C.K., Coppes, M.H., Depreitere, B., Fehlings, M.G., Harrop, J., Kawahara, N., Kim, E.S., Lee, C.S., Leung, Y., Liu, Z.J., Martin-Benlloch, J.A., Massicotte, E.M., Meyer, B., Oner, F.C., Peul, W., Quraishi, N., Tokuhashi, Y., Tomita, K., Ulbricht, C., Verlaan, J.J., Wang, M., and Mazel, C.

Published
2017
Full Text
View/download PDF

49. Premixed mixture ignition in the end-gas region (PREMIER) combustion in a natural gas dual-fuel engine: operating range and exhaust emissions.

Author

Azimov, U, Tomita, E, Kawahara, N, and Harada, Y

Abstract

This paper is concerned with engine experiments and spectroscopic analysis of premixed mixture ignition in the end-gas region (PREMIER) combustion in a pilot fuel ignited, natural gas dual-fuel engine. The results reveal the characteristics and operating parameters that induce and affect this combustion mode. The PREMIER combustion is followed by natural gas flame propagation. Pilot-injected diesel fuel ignites the natural gas/air mixture, and the flame propagates before the natural gas/air mixture is autoignited in the end-gas region. This combustion cycle differs from a knocking cycle in terms of combustion and emission characteristics. The PREMIER combustion can be controlled by pilot fuel injection timing, the equivalence ratio, and the exhaust gas recirculation (EGR) rate, and can be used as an effective method for high load extension on a dual-fuel engine. An analysis of the relationship between the maximum in-cylinder pressure and its crank angle (CA) is used to compare combustion dynamics during conventional, PREMIER, and knocking combustion. In PREMIER combustion, the heat release gradually transforms from the slower first-stage flame rate to the faster second-stage rate. During PREMIER combustion, the maximum indicated mean effective pressure (IMEP) and thermal efficiency increase by about 25 per cent compared with those of conventional combustion, and low carbon monoxide (CO) and total hydrocarbon (HC) emissions can be achieved. However, nitrogen oxide (NOx) emissions increase. Spectroscopic analysis shows that the intensity of the OH* emissions in the end-gas region increases as the combustion mode transforms from conventional to PREMIER to knocking. In all three modes, emission fluctuations above 650 nm can be observed in the end-gas region. These emissions are attributed to the luminosity from soot particles formed during the concurrent diesel fuel combustion. [ABSTRACT FROM PUBLISHER]

Published
2011
Full Text
View/download PDF

50. Total en bloc spondylectomy of the lower lumbar spine: a surgical techniques of combined posterior-anterior approach.

Author

Kawahara N, Tomita K, Murakami H, Demura S, Yoshioka K, Kato S, Kawahara, Norio, Tomita, Katsuro, Murakami, Hideki, Demura, Satoru, Yoshioka, Katsuhito, and Kato, Satoshi

Abstract

Study Design: Ten patients with a spinal tumor of the lower lumbar spine underwent total en bloc spondylectomy (TES) by combined posterior-anterior approach. The oncological and neurologic results are analyzed. Objective: To describe the surgical technique and evaluate the clinical outcome of this surgery. Summary Of the Background Data: TES at lower lumbar spine is technically challenging because of its anatomy such as the presence of major vessels and lumbosacral plexus nerves. Methods: Six aggressive benign tumors and 4 solitary spinal metastases involving L4 or L5 were treated. The approache of operative procedure are discussed as follows: Posterior approach: Dissection of the lumbar nerve roots to the conjunction of the adjacent nerves were performed after en bloc laminectomy by T-saw pediculotomy. The psoas muscle was dissected away, from the vertebral body. The posterior halves of the anterior column at the craniocaudal adjacent levels of the lumbar tumor were cut. Anterior approach: Major vessels were dissected from the vertebral body. Anterior halves of the anterior column were cut at the corresponding levels. The tumor vertebral body was removed en bloc, followed by anterior spinal reconstruction. Results: Seven of 10 cases had no evidence of disease at 57 months on average, 1 case was alive with disease at 66 months, 1 case had death of disease at 42 months, and 1 case had death of another disease at 14 months after surgery. All patients improved or preserved neurologic in the last follow up. The resected specimen of vertebral bodies and laminae showed marginal or wide margin in all cases, although pedicles showed intralesional margin in 8 cases. No local recurrence was observed during lifetime with mean 52 months. Conclusion: TES for spinal tumor of L4 or L5 preserving lumbar nerves was achieved by combined posterior- anterior approach. [ABSTRACT FROM AUTHOR]

Published
2011
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results