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Yamaguchi H.,Tokai University | Kikugawa H.,Tokai University | Asaka T.,Tokai University | Kasuya H.,Tokai University | Kuninori M.,Corporate Research and Development
Materials Transactions | Year: 2011

Bone fracture toughness has been well studied, however, it is also important to investigate the effect of preservative treatment on the mechanical properties of bones. It is necessary to evaluate crack initiation and propagation after fracture because this process may be different in the case of injured bone tissues. In this study, we attempted to analyze the strain distribution on bone tissue surface by using image correlation techniques in order to elucidate the relationship between microscopic bone damage and strain distribution. Bovine femoral cortical bone was employed as the bone specimen and the three-point bend test method was used to determine the fracture toughness, in accordance with the ASTM E399 guidelines. An Instron type machine was used in the fracture toughness test and the loading rate was set to 1 mm/min. Black and white spray paint was applied in a random pattern to the surface of the specimens, and the specimens were loaded until they were ruptured. Bone surface strain analysis was performed using image correlation techniques and the changes were recorded in a digital image. In order to evaluate the effects of preservative treatment on the mechanical properties of bone, we categorized the specimens into 4 groups: the control group included the specimens that were submitted for testing immediately after machining and the preservation group comprised specimens that were analyzed after preservative treatment with different method (formalin, ethanol and physiological saline solution). A strain analysis performed using image correlation techniques allowed the visualization of the increased strain at the forward end of the slit of the specimens. The strain value at the forward end of the slit (the longitudinal direction of specimens) measured at the time of rupture in the control group was approximately 4 times larger than that in the formalin preservation group, thereby suggesting the embrittlement of bone organic constituents due to preservative treatment. © 2011 The Japan Institute of Metals. Source


Davey K.R.,IEEE - Institute of Electrical and Electronics Engineers | Jordan H.E.,Corporate Research and Development | Rodriguez R.J.,Electrical Power Technologies Manassas Laboratory | Hebner R.E.,University of Texas at Austin
Naval Engineers Journal | Year: 2011

The deleterious effect of full bridge rectifiers on the output of an AC generator deserves attention from the Naval community. The harmonics observed at the stator of the generator not only introduce hysteresis and eddy current losses, but voltage spikes that impact the life of the generator. The two primary factors compromising life are localized heating due to harmonics and voltage spikes that cause insulation failure through partial discharge. Induced eddy currents are proportional to frequency squared. © 2012, American Society of Naval Engineers. Source


Englert M.,Corporate Research and Development | Bittmann B.,University of Kaiserslautern | Haupert F.,Hamm-Lippstadt University of Applied Sciences | Schlarb A.K.,University of Kaiserslautern
Polymer Engineering and Science | Year: 2012

Thermosets reinforced with inorganic nanoparticles show numerous benefits over the unreinforced polymer. However, to achieve reinforcement the nanoparticles have to be well separated and distributed homogeneously within the matrix. In the present study the laboratory scale discontinuous ultrasonic dispersion process was scaled up to a continuous ultrasonic dispersion process of agglomerated nanoparticles in epoxy resin (EP). Exemplarily, the dispersion experiments were carried out for a 4-l suspension volume consisting of epoxy resin and 14 vol% TiO 2-nanoparticles was carried out as a function of the dispersion time and the amplitude of the ultrasonic cell. Following, nanocomposites were manufactured with particle contents of 2, 5, and 10 vol%. For the verification of the manufactured nanocomposites quality, particle sizes analysis and mechanical characterization were undertaken. The obtained results were compared with those of the discontinuous dispersion at laboratory scale. It has been found that comparable particle sizes and mechanical properties could be achieved, although, the volume of the suspension was 10 times higher as that one of the batchwise dispersion. © 2011 Society of Plastics Engineers. Source


Hosey G.P.,Corporate Research and Development
2016 Joint International EUROSOI Workshop and International Conference on Ultimate Integration on Silicon, EUROSOI-ULIS 2016 | Year: 2016

As the semiconductor market continues to drive toward increased power in smaller area, the industry will face new challenges in terms of materials and process integrations. These new challenges include power metallurgies, GaN, and a host of other materials. With increasing complexity and increased wafer costs, multiple iterations of experimental silicon are becoming more costly and more time consuming. As a result, the ability to simulate and predict material and geometry responses becomes all the more valuable. Finite element analysis (FEA) is often used for package level simulations, but has gone largely unused at wafer and die level. FEA offers numerous opportunities to explore the effects of temperature, stress, and strain and to evaluate possible solutions. This paper examines use of FEA to evaluate heat dissipation in a buried N+ resistor in an SOI technology and the factors impacting temperature. DC and transient simulations varying current, buried oxide thickness, contact materials, contact areas and substrate thickness, provide information on how heat is dissipated in an SOI power structure without requiring costly and time consuming silicon fabrication. © 2016 IEEE. Source


Yamaguchi H.,Tokai University | Kikugawa H.,Tokai University | Asaka T.,Tokai University | Kasuya H.,Tokai University | Kuninori M.,Corporate Research and Development
Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals | Year: 2010

Bone fracture toughness has been well studied, however, it is also important to investigate the effect of preservative treatment on the mechanical properties of bones. It is necessary to evaluate crack initiation and propagation after fracture because this process may be different in the case of injured bone tissues. In this study, we attempted to analyze the strain distribution on bone tissue surface by using image correlation techniques in order to elucidate the relationship between microscopic bone damage and strain distribution. Bovine femoral cortical bone was employed as the bone specimen and the three-point bend test method was used to determine the fracture toughness, in accordance with the ASTM E399 guidelines. An Instron type machine was used in the fracture toughness test and the loading rate was set to 1 mm/min. Black and white spray paint was applied in a random pattern to the surface of the specimens, and the specimens were loaded until they were ruptured. Bone surface strain analysis was performed using image correlation techniques and the changes were recorded in a digital image. In order to evaluate the effects of preservative treatment on the mechanical properties of bone, we categorized the specimens into 4 groups: the control group included the specimens that were submitted for testing immediately after machining and the preservation group comprised specimens that were analyzed after preservative treatment with different method (formalin, ethanol and physiological saline solution). A strain analysis performed using image correlation techniques allowed the visualization of the increased strain at the forward end of the slit of the specimens. The strain value at the forward end of the slit (the longitudinal direction of specimens) measured at the time of rupture in the control group was approximately 4 times larger than that in the formalin preservation group, thereby suggesting the embrittlement of bone organic constituents due to preservative treatment. © 2010 The Japan Institute of Metals. Source

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