Congruence properties of Apéry numbers

AbstractApéry introduced a recurrence relation for a proof of the irrationality of ζ(3). Let an (n ≥ 0) satisfy the relation n3an − (34n3 − 51n2 + 27n − 5)an − 1 + (n − 1)3an − 2 = 0. Which values of a0 and a1 cause each an to be an integer? This question is answered and some congruence properties of the an are given

Feasibility Investigation of Obstacle-Avoiding Sensors Unit without Image Processing

Feasibility of a simple method to detect step height, slope angle, and trench width using four infrared-light-source PSD range sensors is examined, and the reproducibility and accuracy of characteristic parameter detection are also examined. Detection error of upward slope angle is within 2.5 degrees, while it is shown that the detection error of downward slope angle exceeding 20 degrees is very large. In order to reduce such errors, a method to improve range-voltage performance of a range sensor is proposed, and its availability is demonstrated. We also show that increase in trial frequency is a better way, although so as not to increase the detection delay. Step height is identified with an error of ±1.5 mm. It is shown that trench width cannot be reliably measured at this time. It is suggested that an additional method is needed if we have to advance the field of obstacle detection

Hepatic infarction following abdominal interventional procedures.

To clarify the incidence, background, and progress of hepatic infarction following interventional procedures, cases of hepatic infarction following interventional procedures at our department during the last decade were identified by reviewing the clinical records of 1982 abdominal angiography and interventional procedures and records of abdominal CT. Nine episodes (0.5%) in 8 patients were identified as hepatic infarction following an interventional procedure. Five episodes were preceded by embolization of the hepatic or celiac artery at emergency angiography for postoperative bleeding with hemorrhagic shock. Three episodes followed the elected interventional procedure for hepatocellular carcinoma, and the remaining episode occurred after 12 months of chemoinfusion through an indwelling catheter in the hepatic artery and portal vein. Hepatic arterial occlusion in all episodes and portal venous flow abnormality in 5 episodes were observed on angiography. Four patients whose liver function was initially impaired died of hepatic infarction, although the extent of the disease on CT did not appear to be related to the mortality. Multiple risk factors, including arterial insufficiency, were observed in each patient. The incidence of hepatic infarction following interventional procedures in this series was low but sometimes fatal, and occurred most frequently in emergency embolization in hemorrhagic shock.</p

A Case of Acute Superior Mesenteric Artery Embolism with Severe Ischemic Liver Injury Successfully Treated by Endovascular Treatment

We describe an interesting clinical course of a patient who developed severe ischemic liver injury due to acute embolism of the superior mesenteric artery (SMA) and celiac artery. A 70-year-old man was hospitalized for abdominal pain and diarrhea. Abdominal computed tomography demonstrated a variant common hepatic artery arising from the SMA and multiple thromboembolic occlusions of visceral arteries, including the SMA and celiac artery. Laboratory data showed markedly elevated hepatic enzymes, which increased after admission despite the initiation of systemic anticoagulant and thrombolytic therapy. The patient was successfully treated by endovascular recanalization of the SMA occlusion via transcatheter embolus aspiration, thrombolysis, balloon angioplasty, and stent placement. Severe ischemic liver injury may occur in the setting of synchronous embolism of the SMA and celiac artery, and these phenomena may have a critical impact on the choice of treatment strategies and prognosis. Endovascular treatment appears to an effective treatment option

Characteristics of Aerodynamics and Noise for Tubular Centrifugal Fan (1st report) : Effects of the Areal ratio of Inlet to Outlet of Impeller and the Geometry of Casing

An experimental investigation of a centrifugal fan was conducted with attention to the effects of the geometry of the casing on the aerodynamic and fan noise characteristics. A comparison of the fan noise and the aerodynamic characteristics of the tubular casing with those of scroll casing was made. As a result it was concluded that the aerodynamic characteristics of the fan with scroll casing were superior to those with tubular casing. The measured values of overall sound pressure level for both fans roughly same. When the ratio of inlet area to the outlet area of the impeller becomes nearly unity, the fan characteristics improve. For centrifugal fan with tubular casing, the rotating noise is generated by the interaction of impeller blades of the number with stator vanes and distorted inflow

Characteristics of Aerodynamic and Noise for Tubular Centrifugal Fan (2nd report) : Effects of Belt Case, Inclination of Blade, Size of Casing and Preventive Plate against Reverse Flow

The effects of the belt case, the inclination of blade, the size of casing and the preventive plate of a tubular centrifugal fan on both fan noise and the aerodynamic characteristics are experimentally investigated by using three impellers. The results are summarized as follows : A considerable amount of a rise of pressure and fan efficiency can be expected by using the inclined blade and taking off belt case. Therefore, the specific noise level of the tubular centrifugal fan decrease considerably. In the ratio of casing diameter to impeller diameter is 1.32,the more the distance between the preventive plate against reverse flow and impeller becomes short, the more the fan efficiency and total pressure become high

Experimental Investigation of Obstacle-Avoiding Mobile Robots without Image Processing

A simple method to detect step height, slope angle and trench width using four PSD range sensors (GP2D12) is proposed, and the reproducibility and accuracy of characteristic parameter detection are examined. The detection error of upward slope angle is within 2.5 degrees, while that of downward slope angle exceeded 20 degrees very large. In order to reduce such errors, a range sensor that has better range-voltage performance must be introduced, or we will have to increase trial frequency to prevent detection delay. Step height can be identified with an error off ± 1.5mm. Trench width cannot be reliably measured at this time. It is suggested that an additional method is needed if we are to advance the field of obstacle detection.ELECTRICAL AND ELECTRONIC ENGINEERING, 50th anniversary editio

Percutaneous sclerotherapy for venous malformations using polidocanol under fluoroscopy.

This retrospective study evaluated the safety and efficacy of using polidocanol with X-ray fluoroscopy for percutaneous sclerotherapy of venous malformations of the limbs, head, and neck. The subjects were 16 of 18 patients who presented to our department with venous malformations. Two patients were excluded because they were unlikely to benefit from the treatment. Of the 16 included in the study, 1 could not be treated because of inaccessibility, and another was lost to follow-up. Among the 14 cases that we were able to follow-up, 11 cases had had pain as their primary symptom. Following treatment, this symptom remained unchanged in 1 patient, was improved in 4, and had disappeared in 6; however, there was a recurrence of pain for 3 of these patients. Two patients had sought treatment for cosmetic purposes; following treatment, the lesion disappeared in one and showed a significant reduction in the other. The remaining patient presented with a primary symptom of mouth bleeding, which disappeared following treatment. There were no critical complications. Percutaneous sclerotherapy of venous malformations using polidocanol is safe and effective, and permits repeat treatments. The efficacy is especially good for resolving pain, and complications are minor. It is desirable to use fluoroscopy for these procedures</p