Collapse Load for Thin-Walled Rectangular Tubes

In this chapter, thin-walled rectangular tubes under pure bending are considered, by performing a series of FEM numerical studies. In the simulation, a homogeneous and isotropic elastic perfectly plastic material was employed for the tube material. A commonly used method for predicting the collapse load of rectangular tubes subjected to pure bending was proposed by Kecman. Kecman’s method focuses on a slenderness of the flange. When buckling occurs in the flange, this method uses a collapse load corresponding to the post buckling strength of the flange. When buckling does not occur at the flange, this method used a relation of the flange slenderness to the cross-sectional fully plastic yielding. This method for predicting the collapse loads is effective when the aspect ratio of web to flange is not large. However, for large aspect ratios, there is a large discrepancy between the values of maximum moment corresponding to the collapse loads obtained from this method and the FEM numerical results due to an effect of web slenderness. A new method is proposed to predict the maximum moment considering the effect of web slenderness. The validity of the collapse load estimation is checked by the results of FEM numerical simulation

Prediction of Maximum Moment of Rectangular Tubes Subjected to Pure Bending

In the present paper, the collapse behaviors of rectangular tubes subjected to pure bending are investigated using the finite element method. Such bending collapse has been investigated extensively. These studies have revealed the existence of two types of collapse. The first type is a collapse due to buckling at the compression flange, and the second type is a collapse due to plastic yielding at the flanges. However, another type of collapse may exist. For a rectangular tube in which the web is wider than the flange, collapse due to buckling may occur at the compression web. Furthermore, an approximate prediction method is proposed for estimating the maximum bending moment of rectangular tubes in which web buckling is also taken into account. The validity of this method is verified through comparison with the numerical results obtained by FEM under various conditions

Development of Attitude Sensor using Deep Learning

A new method for attitude determination utilizing color earth images taken with COTS visible light camera is presented. The traditional earth camera has been used for coarse attitude determination by detecting the edge of the earth, and therefore it can only provide coarse and 2-axis information. In contrast, our method recognizes the ground pattern with an accuracy of sub-degrees and can provide 3-axis attitude information by comparing the detected ground pattern and the global map. Moreover, this method has advantages in the size, mass and cost of the detector system which consists of a cheap optical color camera and a single board computer. To demonstrate the method in space, we have developed a sensor system named “Deep Learning Attitude Sensor (DLAS)”. DLAS uses COTS camera modules and single board computers to reduce the cost. The obtained images are promptly analyzed with a newly developed real-time image recognition algorithms

Variable Shape Attitude Control Demonstration with Microsat Hibari

This paper presents the ongoing feasibility study and bus system for microsatellite “Hibari”. The main technical missions for Hibari is called “Variable Shape Attitude Control (VSAC)”. This VSAC is based on an idea to utilize a reaction torque when a part of the satellite structure, for example, solar array paddles is appropriately rotated by actuators. The previous research concluded that VSAC successfully achieved the rapid maneuvering while maintain the high attitude stability against disturbances [1], and thus, it can be applied to a variety of advanced attitude control missions. Hibari project also aims at its application to astronomical mission requiring high pointing stability and agile maneuvering. This paper is mainly comprised of 3 parts: detail mission statement, ongoing feasibility studies and bus system configuration. First, we mention the mission requirement and detail mission sequence for both technical and science missions. Second, we show the ongoing feasibility studies to confirm that all mission requirement is satisfied by VSAC. Third, this paper describes each subsystem configuration to meet the system requirement stated in the mission’s section. And then, we wrap up in the conclusion section and stated the future study for advanced VSAC use in the end

Novel COL11A1 mutation in familial Stickler syndrome

Stickler syndrome (STL) is an autosomal, dominantly inherited, clinically variable and genetically heterogeneous connective tissue disorder characterized by ocular, auditory, orofacial and skeletal abnormalities. We conducted targeted resequencing using a next-generation sequencer for molecular diagnosis of a 2-year-old girl who was clinically suspected of having STL with Pierre Robin sequence. We detected a novel heterozygous missense mutation, NM_001854.3:n.4838G>A [NM_001854.3 (COL11A1_v001):c.4520G>A], in COL11A1, resulting in a Gly to Asp substitution at position 1507 [NM_001854.3(COL11A1_i001)] within one of the collagen-like domains of the triple helical region. The same mutation was detected in her 4-year-old brother with cleft palate and high-frequency sensorineural hearing loss

Development and Initial On-orbit Performance of Multi-Functional Attitude Sensor using Image Recognition

This paper describes a multi-functional attitude sensor mounted on the “Innovative Satellite 1st” led by Japan Aerospace Exploration Agency which was launched in January 2019. In order to achieve the high accuracy determination in low cost, we developed a novel attitude sensor utilizing real-time image recognition technology, named “Deep Learning Attitude Sensor (DLAS)”. DLAS has two type of attitude sensors: Star Tracker(STT) and Earth Camera (ECAM). For the low-cost development, we adopted commercial off-the-shelf cameras. DLAS uses real-time image recognition technology and a new attitude determination algorithm. In this paper, we present the missions, methods and system configuration of DLAS and initial results of on-orbit experiment that was conducted after the middle of February 2019, and it is confirmed that attitude determinations using ECAM and STT are performed correctly

Association of short term exposure to Asian dust with increased blood pressure

Air pollution causes hypertension, cardiovascular disease, and mortality. Asian dust (AD) reportedly induces asthma or acute myocardial infarction along with air pollution, but its impact on blood pressure (BP) is unknown. We investigated the association between short-term AD exposure and BP fluctuations in 300, 952 individuals whose BP was measured during April 2005–March 2015 and divided them into AD and non-AD groups based on visitation for AD-related events. AD’s occurrence, air pollutants’ concentration (suspended particulate matter, SO2, NO2, photochemical oxidants), and meteorological variables (mean ambient temperature, relative humidity) were obtained from a monitoring station; AD events correlated with decreased visibility (< 10 km). We observed 61 AD days, with 3897 participants undergoing medical check-ups. Short-term AD exposure at lag day-0 was significantly associated with higher systolic BP (SBP), diastolic BP (DBP), and pulse rate (PR) risk (β = 1.85, 95% confidence interval (CI) 1.35–2.35 for SBP, β = 2.24, 95% CI 1.88–2.61 for DBP, β = 0.52, 95% CI 0.14–0.91 for PR) using multi-pollutant model. Population-attributable fractions exposed to AD were 11.5% for those with elevated SBP (SBP ≥ 120 mmHg) and 23.7% for those with hypertension (SBP ≥ 140 mmHg or DBP ≥ 90 mmHg). This study showed a strong association between short-term AD exposure and increased SBP and DBP

Clinicopathologic study of mixed adenoneuroendocrine carcinomas of hepatobiliary organs.

Neuroendocrine neoplasms in hepatobiliary organs are very rare, but several cases of mixed adenoneuroendocrine carcinoma (MANEC) have been reported. In this study, we characterized the neuroendocrine component of biliary MANEC. A total of 274 cases of biliary cancer including 17 intrahepatic cholangiocarcinomas (CCs), 15 hepatic hilar CCs without preceding hepatobiliary disease, 55 hepatic hilar CCs with hepatolithiasis, 49 gallbladder cancers, 53 extrahepatic CCs, and 85 hepatocellular carcinomas were examined for a neuroendocrine component using immunohistochemistry with neuroendocrine markers (chromogranin A and synaptophysin). In the MANEC cases, in addition to a close histological examination, the proliferative activity and the expression of somatostatin receptor 2A were also evaluated. In addition to an ordinary adenocarcinoma, a neuroendocrine component occupying more than 30% of the entire tumor was also found in 4% (2/55 cases) of hepatic hilar cholangiocarcinomas with hepatolithiasis, 10% (5/49 cases) of gallbladder cancers, and 4% (2/53 cases) of extrahepatic cholangiocarcinomas, but not in the intrahepatic cholangiocarcinomas, hilar cholangiocarcinomas without preceding hepatobiliary disease, and hepatocellular carcinomas. Two cases were positive for somatostatin receptor 2A. The adenocarcinoma components were predominately located at the surface of the tumors, and the majority of stromal and vascular invasion and lymph node metastasis involved neuroendocrine components, showing the features of neuroendocrine tumor G2 or neuroendocrine carcinomas (NECs). NEC components showed higher proliferative activity on Ki67 immunostaining, compared to the adenocarcinoma components. Biliary MANECs are found in hepatic hilar cholangiocarcinomas with hepatolithiasis, gallbladder cancers, and extrahepatic cholangiocarcinomas and show a characteristic histology. Since the neuroendocrine component in biliary MANEC defines the prognosis, it is important to identify it and consider the indications for adjunctive therapy with somatostatin analogues