To control the wave field, several type of structures have been proposed, submerged plate and submerged breakwater, for example. Submerged flexible sheets are another example, which are composed of textile sheets fixed in frames with elastic springs. It was reported that the later one is more effective because of the resonant interaction between the motion of sheets and waves . An analysis of wave field around this structure has been proposed by Kato et al (1993) using a potential matching method in a vertical 2-D case. But it will rise a difficulty to solve 3-D case using the same method, because of the large number of unknown valuables. In this paper, a new method of analysis is proposed in which the boundary element method with a doublet type of Green function is used and the displacement of sheet is assumed to be half of sinusoidal function . In this method, the necessary number of unknown valuable can be reduced to only one for one sheet and frame system. the numerical results show the validity of this method.

Purpose Intubation and ventilation cannot be performed in cases of parapharyngeal space tumors as the enlargement of the upper airway leads to the obstruction and hindrance of the intubation procedure. However, there is limited literature on anesthetic management, including the airway, in this disease. Herein, we report a successful case of awake intubation in a patient with parapharyngeal space tumor. Case Presentation A 64-year-old man with a history of giant parapharyngeal space tumor was scheduled for bilateral endoscopic sinus surgery and nasal septoplasty. We performed awake intubation using the McGrath ® video laryngoscope, which resulted in excellent laryngeal deployment and a smooth procedure. Conclusion We report the anesthetic management of a giant parapharyngeal space tumor with the potential for difficult airway management to maintain spontaneous breathing. Awake intubation was useful in maintaining ventilation and intubation in this case. The preparation of a cricothyroid puncture is needed in cases of intubation failure.

Non-sebaceous lymphadenoma (NSL) is a rare benign salivary gland tumor that is difficult to diagnose preoperatively on the basis of clinical features. We report a case of NSL arising in the left submandibular region in a 66 -year-old woman. The patient had complained of a painless mass in the left submandibular region. Her medical history included a left parotidectomy for adenoid cystic carcinoma (ACC) 22 years ago. Computed tomography showed an enhanced mass with the inside low-density at the distal part of the submandibular gland and no residual parotid gland. On the basis of these findings, lymph node metastasis from ACC or a submandibular gland tumor was suspected. The mass was removed with the left submandibular gland under general anesthesia. Histopathologically, the mass was diagnosed as a NSL. There has been no sign of recurrence as of 2 years after the operation. : non-sebaceous lymphadenoma (非脂腺型リンパ腺腫) ，submandibular region (顎下部) 1)