27 research outputs found

    Assessment of the Current Level of Automation in the Manufacture of Fuel Cell Systems for Combined Heat and Power Applications

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    The U.S. Department of Energy (DOE) is interested in supporting manufacturing research and development (R&D) for fuel cell systems in the 10-1,000 kilowatt (kW) power range relevant to stationary and distributed combined heat and power applications, with the intent to reduce manufacturing costs and increase production throughput. To assist in future decision-making, DOE requested that the National Renewable Energy Laboratory (NREL) provide a baseline understanding of the current levels of adoption of automation in manufacturing processes and flow, as well as of continuous processes. NREL identified and visited or interviewed key manufacturers, universities, and laboratories relevant to the study using a standard questionnaire. The questionnaire covered the current level of vertical integration, the importance of quality control developments for automation, the current level of automation and source of automation design, critical balance of plant issues, potential for continuous cell manufacturing, key manufacturing steps or processes that would benefit from DOE support for manufacturing R&D, the potential for cell or stack design changes to support automation, and the relationship between production volume and decisions on automation

    Diet composition of the Karpathos marsh frog (Pelophylax cerigensis): what does the most endangered frog in Europe eat?

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    Composición de la dieta de la rana de Kárpatos (Pelophylax cerigensis): ¿qué come la rana más amenazada de Europa? La rana de Kárpatos (Pelophylax cerigensis) es considerada la rana más amenazada de Europa. Aquí evaluamos su ecología alimentaria y examinamos 76 individuos de las dos poblaciones conocidas usando el método del lavado de estómago. También medimos el peso corporal, la longitud desde el hocico hasta la cloaca y el ancho de la boca de las ranas y el ancho y largo de las presas. La dieta de Pelophylax cerigensis, compuesta principalmente por Coleoptera, Aranean, Isopoda e Hymenoptera, es similar a la de otras especies de ranas verdes de las zonas adyacentes. Las dos poblaciones difieren en el tamaño corporal, pero presentan valores similares de abundancia y frecuencia de presas. Parece que P. cerigensis sigue una estricta estrategia de alimentación. El estudio de la disponibilidad de presas en sus hábitats aportará información valiosa.Composición de la dieta de la rana de Kárpatos (Pelophylax cerigensis): ¿qué come la rana más amenazada de Europa? La rana de Kárpatos (Pelophylax cerigensis) es considerada la rana más amenazada de Europa. Aquí evaluamos su ecología alimentaria y examinamos 76 individuos de las dos poblaciones conocidas usando el método del lavado de estómago. También medimos el peso corporal, la longitud desde el hocico hasta la cloaca y el ancho de la boca de las ranas y el ancho y largo de las presas. La dieta de Pelophylax cerigensis, compuesta principalmente por Coleoptera, Aranean, Isopoda e Hymenoptera, es similar a la de otras especies de ranas verdes de las zonas adyacentes. Las dos poblaciones difieren en el tamaño corporal, pero presentan valores similares de abundancia y frecuencia de presas. Parece que P. cerigensis sigue una estricta estrategia de alimentación. El estudio de la disponibilidad de presas en sus hábitats aportará información valiosa.The Karpathos marsh frog (Pelophylax cerigensis) is considered the most endangered frog in Europe. Here we assess its feeding ecology and examine 76 individuals from the two known populations using the stomach flushing method. We also measured body weight, snout–vent length, mouth width and prey width and length. Pelophylax cerigensis follows the feeding pattern of green frogs of the adjacent areas, with Coleoptera, Araneae, Isopoda and Hymenoptera being the main prey groups. The two populations differed in body size but had similar values of prey abundance and frequency. It seems that P. cerigensis follows a strict feeding strategy. Further research on prey availability in its habitats will provide valuable insight

    Guided ultrasound wave propagation in intact and healing long bones

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    Ultrasonic evaluation of bone fracture healing has been traditionally based on the measurement of the propagation velocity of the first arriving signal (FAS). However, the FAS in general corresponds to a lateral wave that propagates along the bone's subsurface. In this work, we study guided ultrasound propagation in intact and healing bones. We developed a 2-D model of a bone-mimicking plate in which the healing process was simulated as a 7-stage process, and we also carried out ex vivo experiments on an intact tibia. Guided waves were represented in the time-frequency (t-f) domain of the signal by incorporating the Lamb wave theory. Three t-f distribution functions were examined, namely the reassigned Spectrogram, the smoothed-pseudo Wigner-Ville, and the reassigned version of it. For the intact plate case, we found that the S2, A3 Lamb modes were the dominant waves for a broadband 1-MHz excitation, and the S2, S0 for a 500-kHz excitation. During the simulated healing process, the mechanical and geometrical callus properties affected the theoretically anticipated Lamb modes. The propagation of guided waves throughout the thickness of the cortical bone and their sensitivity to both the mechanical and structural changes during healing can supplement velocity measurements so as to enhance the monitoring capabilities of ultrasonic evaluation. Nevertheless, the applicability of the Lamb wave theory to real bones has several limitations mostly associated with neglecting the inhomogeneity, anisotropy and irregular geometry of bone. (E-mail: [email protected]) (c) 2006 World Federation for Ultrasound in Medicine & Biology

    Ultrasonic monitoring of bone fracture healing

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    Quantitative ultrasound has attracted significant interest in the evaluation of bone fracture healing. Animal and clinical studies have demonstrated that the propagation velocity across fractured bones can be used as an indicator of healing. Researchers have recently employed computational methods for modeling wave propagation in bones, aiming to gain insight into the underlying mechanisms of wave propagation and to further enhance the monitoring capabilities of ultrasound. In this paper, we reviewthe relevant literature and present the current status of knowledge. © 2006 IEEE

    Diet composition of the karpathos marsh frog (Pelophylax cerigensis): What does the most endangered frog in europe eat? [Composición de la dieta de la rana de kárpatos (Pelophylax cerigensis): ¿qué come la rana más amenazada de europa?]

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    Diet composition of the Karpathos marsh frog (Pelophylax cerigensis): what does the most endangered frog in Europe eat? The Karpathos marsh frog (Pelophylax cerigensis) is considered the most endangered frog in Europe. Here we assess its feeding ecology and examine 76 individuals from the two known populations using the stomach flushing method. We also measured body weight, snout–vent length, mouth width and prey width and length. Pelophylax cerigensis follows the feeding pattern of green frogs of the adjacent areas, with Coleoptera, Araneae, Isopoda and Hymenoptera being the main prey groups. The two populations differed in body size but had similar values of prey abundance and frequency. It seems that P. cerigensis follows a strict feeding strategy. Further research on prey availability in its habitats will provide valuable insight. © 2019 Museu de Ciències Naturals de Barcelona

    Diet composition of the karpathos marsh frog (Pelophylax cerigensis): What does the most endangered frog in europe eat?

    No full text
    Diet composition of the Karpathos marsh frog (Pelophylax cerigensis): what does the most endangered frog in Europe eat? The Karpathos marsh frog (Pelophylax cerigensis) is considered the most endangered frog in Europe. Here we assess its feeding ecology and examine 76 individuals from the two known populations using the stomach flushing method. We also measured body weight, snout–vent length, mouth width and prey width and length. Pelophylax cerigensis follows the feeding pattern of green frogs of the adjacent areas, with Coleoptera, Araneae, Isopoda and Hymenoptera being the main prey groups. The two populations differed in body size but had similar values of prey abundance and frequency. It seems that P. cerigensis follows a strict feeding strategy. Further research on prey availability in its habitats will provide valuable insight. © 2019 Museu de Ciències Naturals de Barcelona

    Mucocele of the vermiform appendix misdiagnosed as an adnexal mass on transvaginal sonography

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    Mucocele of the vermiform appendix is a rare entity that may mimic a right-sided adnexal mass. We describe a case of appendiceal mucocele in a 78-year-old woman that was initially misdiagnosed as a potentially malignant right ovarian tumor and briefly review the literature on sonographic features of this entity. It is important to improve preoperative diagnosis so as to prevent rupture of mucocele at surgery, which may lead to pseudomyxoma peritonei, and also to seek intraoperatively for the presence of synchronous colorectal neoplasms. © 2011 Wiley Periodicals, Inc

    Transosseous application of low-intensity ultrasound for the enhancement and monitoring of fracture healing process in a sheep osteotomy model

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    The purpose of this study is twofold: (a) to investigate the application of transosseous low-intensity pulsed ultrasound (LiUS) on the enhancement of fracture healing and (b) to demonstrate the ability of transosseous ultrasound propagation to monitor the healing process. A midshaft tibial osteotomy model was used on 40 skeletally mature sheep, and an external fixator was applied to maintain the reduction and stabilization of the osteotomy. Two ultrasound transducers were implanted into the fracture site in contact with the bone. For investigating the efficacy of LiUS, the animals were randomly divided in two equal groups: the treatment group and the control group. The LiUS-treated animals received 200-mu s bursts of 1-MHz sine waves with a pulse repetition rate of 1 kHz and average intensity of 30 mW/cm(2), for 20 min daily. For monitoring purposes, an ultrasound dataset was constructed consisting of serial ultrasound measurements obtained from healing bones. Animals' sacrifice took place on the 100th postoperative day. The effect of LiUS on fracture healing was evaluated using radiographs, destructive three-point bending testing and quantitative CT-based bone mineral density (BMD) measurements. Survival analysis using Kaplan-Meier curves showed significantly higher probability of radiographic healing for the animals in the treatment group (P = 0.009). Statistical significance was also observed for callus BMD (P = 0.003, Wilcoxon nonparametric test), the breaking load (P = 0.001), extrinsic stiffness (P = 0.019), Young's modulus (P = 0.043) and ultimate strength (P = 0.051) in favor of the LiUS-treated limbs. Analysis of the obtained ultrasonic measurements showed that the propagation velocity across healing bones constitutes a significant feature able to early distinguish between healed and nonhealed bones (area under ROC curve was 0.810 and 0.841 on the 80th and 100th post-operative days, respectively). Both the LiUS application and the ultrasonic measurements are supported by an integrated telemedicine system which also incorporates an ultrasound wearable device and a patient management system. (c) 2005 Elsevier Inc. All rights reserved
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