Peridynamic modeling for crack propagation analysis of materials

In this paper, the computer simulations are carried out by using the peridynamic theory model with various conditions including quasi-static loads, dynamic loads and crack propagation, branching crack pattern and isotropic materials, orthotropic materials. Three examples, a plate with a hole under quasi-static loading, a plate with a pre-existing crack under dynamic loading and a lamina with a pre-existing crack under quasi-static loading are analyzed by computational simulations. In order to simulate the quasi-static load, an adaptive dynamic relaxation technique is used. In the orthotropic material analysis, a homogenization method is used considering the strain energy density ratio between the classical continuum mechanics and the peridynamic. As a result, crack propagation and branching cracks are observed successfully and the direction and initiation of the crack are also captured within the peridynamic modeling. In case of applying peridynamic used homogenization method to a relatively complicated orthotropic material, it is also verified by comparing with experimental result

Recycling Studies for Swine Manure Slurry Using Multi Process of Aerobic Digestion (MPAD)

This study was carried out to investigate the feasibility of Multi Process of Aerobic Digestion (MPAD) for recycling of swine manure slurry as fertilizer. MPAD consisted of three kinds of difference process which are thermophilic aerobic oxidation (TAO) system, lime solidification system, and reverse osmosis (R/O) membrane system. TAO system was studied well previously for decade. The chemical composition of the lime-treated solid fertilizer was as like that organic matter 17.4%, moisture 34.1%, N 0.9%, P 1.7%, K 0.3%, Ca 12.7%, and which was expected to be useful as acid soil amendment material. The concentrated liquid material produced by R/O membrane system was also expected as a good fertilizer for crops production and soil fertility improvement.OtherShinshu University International Symposium 2010 : Sustainable Agriculture and Environment : Asian Networks II 　信州大学国際シンポジウム2010 : 持続的農業と環境 : アジアネットワークII ― アジアネットワークの発展をめざして―. 信州大学農学部, 2010, 71-77conference pape

Monitoring Observations of the Jupiter-Family Comet 17P/Holmes during 2014 Perihelion Passage

We performed a monitoring observation of a Jupiter-Family comet, 17P/Holmes, during its 2014 perihelion passage to investigate its secular change in activity. The comet has drawn the attention of astronomers since its historic outburst in 2007, and this occasion was its first perihelion passage since then. We analyzed the obtained data using aperture photometry package and derived the Afrho parameter, a proxy for the dust production rate. We found that Afrho showed asymmetric properties with respect to the perihelion passage: it increased moderately from 100 cm at the heliocentric distance r_h=2.6-3.1 AU to a maximal value of 185 cm at r_h = 2.2 AU (near the perihelion) during the inbound orbit, while dropping rapidly to 35 cm at r_h = 3.2 AU during the outbound orbit. We applied a model for characterizing dust production rates as a function of r_h and found that the fractional active area of the cometary nucleus had dropped from 20%-40% in 2008-2011 (around the aphelion) to 0.1%-0.3% in 2014-2015 (around the perihelion). This result suggests that a dust mantle would have developed rapidly in only one orbital revolution around the sun. Although a minor eruption was observed on UT 2015 January 26 at r_h = 3.0 AU, the areas excavated by the 2007 outburst would be covered with a layer of dust (<~ 10 cm depth) which would be enough to insulate the subsurface ice and to keep the nucleus in a state of low activity.Comment: 25 pages, 6 figures, 2 tables, ApJ accepted on December 29, 201

Sonographic measurements of normal gallbladder sizes in children.

PurposeOur goal was to establish the range of sonographic measurements of normal gallbladders in children.MethodsSix hundred ten children aged 0-16 years (male:female ratio, 1.5:1) with normal clinical and laboratory findings were included in this study. The sonographic parameters were the length, width, and calculated volume of the gallbladder, and the clinical parameters were the age, height, weight, and body surface area of the children. Statistical significance was determined through correlation and regression analyses.ResultsThe length of the gallbladder showed significant positive correlations with age (r = 0.65), height (r = 0.67), weight (r = 0.63), and body surface area (r = 0.65; p &lt; 0.01). The calculated volume of the gallbladder also showed moderate correlations with age (r = 0.53), height (r = 0.55), weight (r = 0.61), and body surface area (r = 0.57; p &lt; 0.01). The gallbladder width showed modest but significant correlations with age (r = 0.48), height (r = 0.53), weight (r = 0.53), and body surface area (r = 0.55; p &lt; 0.01). The highest correlation coefficients were found between the gallbladder length and subject age (r = 0.65; p &lt; 0.01) and between the gallbladder length and subject height (r = 0.67; p &lt; 0.01). For all correlations, statistical significance remained after regression analysis (p &lt; 0.01).ConclusionsValues for the size of the normal pediatric gallbladder are defined and will be helpful in the diagnosis of gallbladder abnormalities