Science.gov

Sample records for signal strength based

  1. A signal strength priority based position estimation for mobile platforms

    NASA Astrophysics Data System (ADS)

    Kalgikar, Bhargav; Akopian, David; Chen, Philip

    2010-01-01

    Global Positioning System (GPS) products help to navigate while driving, hiking, boating, and flying. GPS uses a combination of orbiting satellites to determine position coordinates. This works great in most outdoor areas, but the satellite signals are not strong enough to penetrate inside most indoor environments. As a result, a new strain of indoor positioning technologies that make use of 802.11 wireless LANs (WLAN) is beginning to appear on the market. In WLAN positioning the system either monitors propagation delays between wireless access points and wireless device users to apply trilateration techniques or it maintains the database of location-specific signal fingerprints which is used to identify the most likely match of incoming signal data with those preliminary surveyed and saved in the database. In this paper we investigate the issue of deploying WLAN positioning software on mobile platforms with typically limited computational resources. We suggest a novel received signal strength rank order based location estimation system to reduce computational loads with a robust performance. The proposed system performance is compared to conventional approaches.

  2. Assessment of Receiver Signal Strength Sensing for Location Estimation Based on Fisher Information.

    PubMed

    Nielsen, John; Nielsen, Christopher

    2016-01-01

    Currently there is almost ubiquitous availability of wireless signaling for data communications within commercial building complexes resulting in receiver signal strength (RSS) observables that are typically sufficient for generating viable location estimates of mobile wireless devices. However, while RSS observables are generally plentiful, achieving an accurate estimation of location is difficult due to several factors affecting the electromagnetic coupling between the mobile antenna and the building access points that are not modeled and hence contribute to the overall estimation uncertainty. Such uncertainty is typically mitigated with a moderate redundancy of RSS sensor observations in combination with other constraints imposed on the mobile trajectory. In this paper, the Fisher Information (FI) of a set of RSS sensor observations in the context of variables related to the mobile location is developed. This provides a practical method of determining the potential location accuracy for the given set of wireless signals available. Furthermore, the information value of individual RSS measurements can be quantified and the RSS observables weighted accordingly in estimation combining algorithms. The practical utility of using FI in this context was demonstrated experimentally with an extensive set of RSS measurements recorded in an office complex. The resulting deviation of the mobile location estimation based on application of weighted likelihood processing to the experimental RSS data was shown to agree closely with the Cramer Rao bound determined from the FI analysis. PMID:27669262

  3. R2NA: Received Signal Strength (RSS) Ratio-Based Node Authentication for Body Area Network

    PubMed Central

    Wu, Yang; Wang, Kai; Sun, Yongmei; Ji, Yuefeng

    2013-01-01

    The body area network (BAN) is an emerging branch of wireless sensor networks for personalized applications. The services in BAN usually have a high requirement on security, especially for the medical diagnosis. One of the fundamental directions to ensure security in BAN is how to provide node authentication. Traditional research using cryptography relies on prior secrets shared among nodes, which leads to high resource cost. In addition, most existing non-cryptographic solutions exploit out-of-band (OOB) channels, but they need the help of additional hardware support or significant modifications to the system software. To avoid the above problems, this paper presents a proximity-based node authentication scheme, which only uses wireless modules equipped on sensors. With only one sensor and one control unit (CU) in BAN, we could detect a unique physical layer characteristic, namely, the difference between the received signal strength (RSS) measured on different devices in BAN. Through the above-mentioned particular difference, we can tell whether the sender is close enough to be legitimate. We validate our scheme through both theoretical analysis and experiments, which are conducted on the real Shimmer nodes. The results demonstrate that our proposed scheme has a good security performance.

  4. Signal Amplification in Field Effect-Based Sandwich Enzyme-Linked Immunosensing by Tuned Buffer Concentration with Ionic Strength Adjuster.

    PubMed

    Kumar, Satyendra; Kumar, Narendra; Panda, Siddhartha

    2016-04-01

    Miniaturization of the sandwich enzyme-based immunosensor has several advantages but could result in lower signal strength due to lower enzyme loading. Hence, technologies for amplification of the signal are needed. Signal amplification in a field effect-based electrochemical immunosensor utilizing chip-based ELISA is presented in this work. First, the molarities of phosphate buffer saline (PBS) and concentrations of KCl as ionic strength adjuster were optimized to maximize the GOx glucose-based enzymatic reactions in a beaker for signal amplification measured by change in the voltage shift with an EIS device (using 20 μl of solution) and validated with a commercial pH meter (using 3 ml of solution). The PBS molarity of 100 μM with 25 mM KCl provided the maximum voltage shift. These optimized buffer conditions were further verified for GOx immobilized on silicon chips, and similar trends with decreased PBS molarity were obtained; however, the voltage shift values obtained on chip reaction were lower as compared to the reactions occurring in the beaker. The decreased voltage shift with immobilized enzyme on chip could be attributed to the increased Km (Michaelis-Menten constant) values in the immobilized GOx. Finally, a more than sixfold signal enhancement (from 8 to 47 mV) for the chip-based sandwich immunoassay was obtained by altering the PBS molarity from 10 to 100 μM with 25 mM KCl.

  5. PRIMAL: Page Rank-Based Indoor Mapping and Localization Using Gene-Sequenced Unlabeled WLAN Received Signal Strength.

    PubMed

    Zhou, Mu; Zhang, Qiao; Xu, Kunjie; Tian, Zengshan; Wang, Yanmeng; He, Wei

    2015-01-01

    Due to the wide deployment of wireless local area networks (WLAN), received signal strength (RSS)-based indoor WLAN localization has attracted considerable attention in both academia and industry. In this paper, we propose a novel page rank-based indoor mapping and localization (PRIMAL) by using the gene-sequenced unlabeled WLAN RSS for simultaneous localization and mapping (SLAM). Specifically, first of all, based on the observation of the motion patterns of the people in the target environment, we use the Allen logic to construct the mobility graph to characterize the connectivity among different areas of interest. Second, the concept of gene sequencing is utilized to assemble the sporadically-collected RSS sequences into a signal graph based on the transition relations among different RSS sequences. Third, we apply the graph drawing approach to exhibit both the mobility graph and signal graph in a more readable manner. Finally, the page rank (PR) algorithm is proposed to construct the mapping from the signal graph into the mobility graph. The experimental results show that the proposed approach achieves satisfactory localization accuracy and meanwhile avoids the intensive time and labor cost involved in the conventional location fingerprinting-based indoor WLAN localization. PMID:26404274

  6. PRIMAL: Page Rank-Based Indoor Mapping and Localization Using Gene-Sequenced Unlabeled WLAN Received Signal Strength

    PubMed Central

    Zhou, Mu; Zhang, Qiao; Xu, Kunjie; Tian, Zengshan; Wang, Yanmeng; He, Wei

    2015-01-01

    Due to the wide deployment of wireless local area networks (WLAN), received signal strength (RSS)-based indoor WLAN localization has attracted considerable attention in both academia and industry. In this paper, we propose a novel page rank-based indoor mapping and localization (PRIMAL) by using the gene-sequenced unlabeled WLAN RSS for simultaneous localization and mapping (SLAM). Specifically, first of all, based on the observation of the motion patterns of the people in the target environment, we use the Allen logic to construct the mobility graph to characterize the connectivity among different areas of interest. Second, the concept of gene sequencing is utilized to assemble the sporadically-collected RSS sequences into a signal graph based on the transition relations among different RSS sequences. Third, we apply the graph drawing approach to exhibit both the mobility graph and signal graph in a more readable manner. Finally, the page rank (PR) algorithm is proposed to construct the mapping from the signal graph into the mobility graph. The experimental results show that the proposed approach achieves satisfactory localization accuracy and meanwhile avoids the intensive time and labor cost involved in the conventional location fingerprinting-based indoor WLAN localization. PMID:26404274

  7. PRIMAL: Page Rank-Based Indoor Mapping and Localization Using Gene-Sequenced Unlabeled WLAN Received Signal Strength.

    PubMed

    Zhou, Mu; Zhang, Qiao; Xu, Kunjie; Tian, Zengshan; Wang, Yanmeng; He, Wei

    2015-09-25

    Due to the wide deployment of wireless local area networks (WLAN), received signal strength (RSS)-based indoor WLAN localization has attracted considerable attention in both academia and industry. In this paper, we propose a novel page rank-based indoor mapping and localization (PRIMAL) by using the gene-sequenced unlabeled WLAN RSS for simultaneous localization and mapping (SLAM). Specifically, first of all, based on the observation of the motion patterns of the people in the target environment, we use the Allen logic to construct the mobility graph to characterize the connectivity among different areas of interest. Second, the concept of gene sequencing is utilized to assemble the sporadically-collected RSS sequences into a signal graph based on the transition relations among different RSS sequences. Third, we apply the graph drawing approach to exhibit both the mobility graph and signal graph in a more readable manner. Finally, the page rank (PR) algorithm is proposed to construct the mapping from the signal graph into the mobility graph. The experimental results show that the proposed approach achieves satisfactory localization accuracy and meanwhile avoids the intensive time and labor cost involved in the conventional location fingerprinting-based indoor WLAN localization.

  8. DWI based thermometry: the effects of b-values, resolutions, signal-to-noise ratio, and magnet strength.

    PubMed

    Sakai, Koji; Sakamoto, Ryo; Okada, Tomohisa; Sugimoto, Naozo; Togashi, Kaori

    2012-01-01

    Among MR methods, the most clinically applicable temperature measurement method at deep brain might be the diffusion-weighted image (DWI) thermometry. Although only applicable to cerebrospinal fluid (CSF), it is thought to be potentially useful in assessing the thermal pathophysiology of the brain in both patients and healthy subjects. The purpose of this study was to investigate the effects of b-value, pixel resolution, magnet strength and signal to noise ratio (SNR) for the DWI-thermometry with healthy volunteer. Formerly, an ADC from b=0 and b=1000 has been thought to be useful for diffusion thermometry, this study revealed b=200 to 800 was more appropriate for DWI thermometry. The SNR was strongly affected the results of DWI thermometry.

  9. Monitoring Activity for Recognition of Illness in Experimentally Infected Weaned Piglets Using Received Signal Strength Indication ZigBee-based Wireless Acceleration Sensor

    PubMed Central

    Ahmed, Sonia Tabasum; Mun, Hong-Seok; Islam, Md. Manirul; Yoe, Hyun; Yang, Chul-Ju

    2016-01-01

    In this experiment, we proposed and implemented a disease forecasting system using a received signal strength indication ZigBee-based wireless network with a 3-axis acceleration sensor to detect illness at an early stage by monitoring movement of experimentally infected weaned piglets. Twenty seven piglets were divided into control, Salmonella enteritidis (SE) infection, and Escherichia coli (EC) infection group, and their movements were monitored for five days using wireless sensor nodes on their backs. Data generated showed the 3-axis movement of piglets (X-axis: left and right direction, Y-axis: anteroposterior direction, and Z-axis: up and down direction) at five different time periods. Piglets in both infected groups had lower weight gain and feed intake, as well as higher feed conversion ratios than the control group (p<0.05). Infection with SE and EC resulted in reduced body temperature of the piglets at day 2, 4, and 5 (p<0.05). The early morning X-axis movement did not differ between groups; however, the Y-axis movement was higher in the EC group (day 1 and 2), and the Z-axis movement was higher in the EC (day 1) and SE group (day 4) during different experimental periods (p<0.05). The morning X and Y-axis movement did not differ between treatment groups. However, the Z-axis movement was higher in both infected groups at day 1 and lower at day 4 compared to the control (p<0.05). The midday X-axis movement was significantly lower in both infected groups (day 4 and 5) compared to the control (p<0.05), whereas the Y-axis movement did not differ. The Z-axis movement was highest in the SE group at day 1 and 2 and lower at day 4 and 5 (p<0.05). Evening X-axis movement was highest in the control group throughout the experimental period. During day 1 and 2, the Z-axis movement was higher in both of the infected groups; whereas it was lower in the SE group during day 3 and 4 (p<0.05). During day 1 and 2, the night X-axis movement was lower and the Z-axis movement

  10. The Strength-Based Counseling Model

    ERIC Educational Resources Information Center

    Smith, Elsie J.

    2006-01-01

    This article proposes a strength-based model for counseling at-risk youth. The author presents the assumptions, basic concepts, and values of the strength perspective in counseling and offers strength categories as a conceptual model for viewing clients' behavior. Propositions leading toward a theory of strength-based counseling and stages of this…

  11. Strength properties of fly ash based controlled low strength materials.

    PubMed

    Türkel, S

    2007-08-25

    Controlled low strength material (CLSM) is a flowable mixture that can be used as a backfill material in place of compacted soils. Flowable fill requires no tamping or compaction to achieve its strength and typically has a load carrying capacity much higher than compacted soils, but it can still be excavated easily. The selection of CLSM type should be based on technical and economical considerations for specific applications. In this study, a mixture of high volume fly ash (FA), crushed limestone powder (filler) and a low percentage of pozzolana cement have been tried in different compositions. The amount of pozzolana cement was kept constant for all mixes as, 5% of fly ash weight. The amount of mixing water was chosen in order to provide optimum pumpability by determining the spreading ratio of CLSM mixtures using flow table method. The shear strength of the material is a measure of the materials ability to support imposed stresses on the material. The shear strength properties of CLSM mixtures have been investigated by a series of laboratory tests. The direct shear test procedure was applied for determining the strength parameters Phi (angle of shearing resistance) and C(h) (cohesion intercept) of the material. The test results indicated that CLSM mixtures have superior shear strength properties compared to compacted soils. Shear strength, cohesion intercept and angle of shearing resistance values of CLSM mixtures exceeded conventional soil materials' similar properties at 7 days. These parameters proved that CLSM mixtures are suitable materials for backfill applications.

  12. Correlation of nighttime MF signal strength with solar activity

    NASA Astrophysics Data System (ADS)

    Kohata, Hiroki; Kimura, Iwane; Wakai, Noboru; Ogawa, Tadahiko

    Observations of the signal strength of MF broadcasting signals (774/770 kHz) transmitted from Akita, Japan, on board the Japanese Antarctic ice breaker Fuji, bound from Japan to Syowa station, Antarctica, have revealed an interesting positive correlation between strengths of long distance signals propagating at night and solar activity. It is already known that MF propagation characteristics in North America show a negative correlation with solar activity. The present paper, interprets the results by using the multihop method with full-wave analysis. The difference in correlation with solar activity between the results of Fuji and those in North America can be elucidated if it is assumed that there is a ledge in the electron-density profile around an altitude range of 85 to 90 km and that the density of the ledge is smaller in the North American region than in the equatorial region.

  13. Measuring Radiofrequency and Microwave Radiation from Varying Signal Strengths

    NASA Technical Reports Server (NTRS)

    Davis, Bette; Gaul, W. C.

    2007-01-01

    This viewgraph presentation discusses the process of measuring radiofrequency and microwave radiation from various signal strengths. The topics include: 1) Limits and Guidelines; 2) Typical Variable Standard (IEEE) Frequency Dependent; 3) FCC Standard 47 CFR 1.1310; 4) Compliance Follows Unity Rule; 5) Multiple Sources Contribute; 6) Types of RF Signals; 7) Interfering Radiations; 8) Different Frequencies Different Powers; 9) Power Summing - Peak Power; 10) Contribution from Various Single Sources; 11) Total Power from Multiple Sources; 12) Are You Out of Compliance?; and 13) In Compliance.

  14. Vehicle Motions as Inferred from Radio-signal- Strength Records

    NASA Technical Reports Server (NTRS)

    Pilkington, W. C.

    1958-01-01

    Considerable data on various parameters of a satellite and its launching vehicle can be obtained from the received-signal-strength records at the various satellite receiver stations. The doppler shifts of the satellite can be used to determine the orbital characteristics quite accurately. (Ref. 1 discusses the rapid determination of these parameters.) Information concerning the velocity increment and direction of each stage can be obtained if doppler data are received by several stations during the high-speed staging. The variations in signal strength during launch can be used to find the spin rate of the satellite before, during, and after staging, and to find variations in attitude, including precession, during launch. With spin and precession frequencies available, any changes in the ratios of moments of inertia can be determined. In this paper the launchings of the Explorer satellites will be used as a basis for the generalized conclusions concerning utilization of radio-signal-strength records. The discussion includes a description of the Explorer launching system.

  15. BMP signaling and microtubule organization regulate synaptic strength

    PubMed Central

    Ball, Robin W.; Peled, Einat; Guerrero, Giovanna; Isacoff, Ehud Y.

    2015-01-01

    The strength of synaptic transmission between a neuron and multiple postsynaptic partners can vary considerably. We have studied synaptic heterogeneity using the glutamatergic Drosophila neuromuscular junction (NMJ), which contains multiple synaptic connections of varying strength between a motor axon and muscle fiber. In larval NMJs, there is a gradient of synaptic transmission from weak proximal to strong distal boutons. We imaged synaptic transmission with the postsynaptically targeted fluorescent calcium sensor SynapCam, to investigate the molecular pathways that determine synaptic strength and set up this gradient. We discovered that mutations in the Bone Morphogenetic Protein (BMP) signaling pathway disrupt production of strong distal boutons. We find that strong connections contain unbundled microtubules in the boutons, suggesting a role for microtubule organization in transmission strength. The spastin mutation, which disorganizes microtubules, disrupted the transmission gradient, supporting this interpretation. We propose that the BMP pathway, shown previously to function in the homeostatic regulation of synaptic growth, also boosts synaptic transmission in a spatially selective manner that depends on the microtubule system. PMID:25681521

  16. 47 CFR 80.753 - Signal strength requirements at the service area contour.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Signal strength requirements at the service area contour. 80.753 Section 80.753 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... Station VHF Coverage § 80.753 Signal strength requirements at the service area contour. (a)...

  17. 47 CFR 80.753 - Signal strength requirements at the service area contour.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Signal strength requirements at the service area contour. 80.753 Section 80.753 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... Station VHF Coverage § 80.753 Signal strength requirements at the service area contour. (a)...

  18. 47 CFR 80.753 - Signal strength requirements at the service area contour.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Signal strength requirements at the service area contour. 80.753 Section 80.753 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... Station VHF Coverage § 80.753 Signal strength requirements at the service area contour. (a)...

  19. 47 CFR 80.753 - Signal strength requirements at the service area contour.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Signal strength requirements at the service area contour. 80.753 Section 80.753 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... Station VHF Coverage § 80.753 Signal strength requirements at the service area contour. (a)...

  20. 47 CFR 80.753 - Signal strength requirements at the service area contour.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Signal strength requirements at the service area contour. 80.753 Section 80.753 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... Station VHF Coverage § 80.753 Signal strength requirements at the service area contour. (a)...

  1. Infusing Cultural Competence and Advocacy into Strength-Based Counseling

    ERIC Educational Resources Information Center

    Grothaus, Tim; McAuliffe, Garett; Craigen, Laurie

    2012-01-01

    Strength-based counseling represents a welcome shift from prevailing deficit perspectives. However, the literature often treats enhancing strengths as an acultural concept, minimizing or ignoring the essential role of culture in forming and defining strengths. Integrating cultural competence and advocacy into strength-based practice is examined as…

  2. Received Signal Strength Database Interpolation by Kriging for a Wi-Fi Indoor Positioning System

    PubMed Central

    Jan, Shau-Shiun; Yeh, Shuo-Ju; Liu, Ya-Wen

    2015-01-01

    The main approach for a Wi-Fi indoor positioning system is based on the received signal strength (RSS) measurements, and the fingerprinting method is utilized to determine the user position by matching the RSS values with the pre-surveyed RSS database. To build a RSS fingerprint database is essential for an RSS based indoor positioning system, and building such a RSS fingerprint database requires lots of time and effort. As the range of the indoor environment becomes larger, labor is increased. To provide better indoor positioning services and to reduce the labor required for the establishment of the positioning system at the same time, an indoor positioning system with an appropriate spatial interpolation method is needed. In addition, the advantage of the RSS approach is that the signal strength decays as the transmission distance increases, and this signal propagation characteristic is applied to an interpolated database with the Kriging algorithm in this paper. Using the distribution of reference points (RPs) at measured points, the signal propagation model of the Wi-Fi access point (AP) in the building can be built and expressed as a function. The function, as the spatial structure of the environment, can create the RSS database quickly in different indoor environments. Thus, in this paper, a Wi-Fi indoor positioning system based on the Kriging fingerprinting method is developed. As shown in the experiment results, with a 72.2% probability, the error of the extended RSS database with Kriging is less than 3 dBm compared to the surveyed RSS database. Importantly, the positioning error of the developed Wi-Fi indoor positioning system with Kriging is reduced by 17.9% in average than that without Kriging. PMID:26343673

  3. Received Signal Strength Database Interpolation by Kriging for a Wi-Fi Indoor Positioning System.

    PubMed

    Jan, Shau-Shiun; Yeh, Shuo-Ju; Liu, Ya-Wen

    2015-08-28

    The main approach for a Wi-Fi indoor positioning system is based on the received signal strength (RSS) measurements, and the fingerprinting method is utilized to determine the user position by matching the RSS values with the pre-surveyed RSS database. To build a RSS fingerprint database is essential for an RSS based indoor positioning system, and building such a RSS fingerprint database requires lots of time and effort. As the range of the indoor environment becomes larger, labor is increased. To provide better indoor positioning services and to reduce the labor required for the establishment of the positioning system at the same time, an indoor positioning system with an appropriate spatial interpolation method is needed. In addition, the advantage of the RSS approach is that the signal strength decays as the transmission distance increases, and this signal propagation characteristic is applied to an interpolated database with the Kriging algorithm in this paper. Using the distribution of reference points (RPs) at measured points, the signal propagation model of the Wi-Fi access point (AP) in the building can be built and expressed as a function. The function, as the spatial structure of the environment, can create the RSS database quickly in different indoor environments. Thus, in this paper, a Wi-Fi indoor positioning system based on the Kriging fingerprinting method is developed. As shown in the experiment results, with a 72.2% probability, the error of the extended RSS database with Kriging is less than 3 dBm compared to the surveyed RSS database. Importantly, the positioning error of the developed Wi-Fi indoor positioning system with Kriging is reduced by 17.9% in average than that without Kriging.

  4. Measuring Soil Moisture using the Signal Strength of Buried Bluetooth Devices.

    NASA Astrophysics Data System (ADS)

    Hut, R.; Campbell, C. S.

    2015-12-01

    A low power bluetooth Low Energy (BLE) device is burried 20cm into the soil and a smartphone is placed on top of the soil to test if bluetooth signal strength can be related to soil moisture. The smartphone continuesly records and stores bluetooth signal strength of the device. The soil is artifcially wetted and drained. Results show a relation between BLE signal strength and soil moisture that could be used to measure soil moisture using these off-the-shelf consumer electronics. This opens the possibily to develop sensors that can be buried into the soil, possibly below the plow-line. These sensors can measure local parameters such as electric conductivity, ph, pressure, etc. Readings would be uploaded to a device on the surface using BLE. The signal strength of this BLE would be an (additional) measurement of soil moisture.

  5. Strengths-Based Education: Probing Its Limits. The Cutting Edge

    ERIC Educational Resources Information Center

    Clabaugh, Gary K.

    2005-01-01

    Except for Timothy Hodges and James Harter's restrained research summary, the feature articles in this issue are evangelical in their praise of strengths-based education. It is, they assure us, a major innovation. English teacher Alexis Onishi writes that StrengthsQuest, a specific strengths-based approach, will have "a lifelong impact on how…

  6. Quantitative immunohistochemistry by measuring cumulative signal strength using commercially available software photoshop and matlab.

    PubMed

    Matkowskyj, K A; Schonfeld, D; Benya, R V

    2000-02-01

    Currently available techniques for performing quantitative immunohistochemistry (Q-IHC) rely upon pixel-counting algorithms and therefore cannot provide information as to the absolute amount of chromogen present. We describe a novel algorithm for true Q-IHC based on calculating the cumulative signal strength, or energy, of the digital file representing any portion of an image. This algorithm involves subtracting the energy of the digital file encoding the control image (i.e., not exposed to antibody) from that of the experimental image (i.e., antibody-treated). In this manner, the absolute amount of antibody-specific chromogen per pixel can be determined for any cellular region or structure. (J Histochem Cytochem 48:303-311, 2000)

  7. Retentive shear strengths of various bonding attachment bases.

    PubMed

    Lopez, J I

    1980-06-01

    The purpose of this study was to determine whether any of the commercially available attachment bases had significantly better retentive properties. This was determined by their shear strengths after all were bonded to bovine incisors with Auto-Tach. The mean shear strengths of sixteen bases were statistically compared to each other at 24 hours and at 30 days. In addition, the data were converted to pounds per square inch to ascertain if the size of the base significantly influenced the mean shear strength. It was concluded that (1). one of the foil mesh bases tested for shear strength was significantly superior to the two other base designs (indents with undercuts and solid bases with perforations); (2). mechanical retention of the attachment bases to the adhesive was not significantly affected after being placed in distilled water at 37 degrees C. either for 24 hours or for 30 days; (3). smaller foil mesh bases could be used without sacrificing significant shear strength.

  8. Passive vortex currents in magneto- and electrocardiography: comparison of magnetic and electric signal strengths

    NASA Astrophysics Data System (ADS)

    Dutz, Silvio; Bellemann, Matthias E.; Leder, Uwe; Haueisen, Jens

    2006-01-01

    Vortex currents may be of importance in the early diagnosis of myocardial infarction caused by an occlusion of a coronary artery. We investigated the influence of a passive vortex current distribution, modelled by different conductivities in a hollow cylinder, on the localization error and on the signal strength in both the magnetocardiogram and the electrocardiogram. The hollow cylinder was mounted in a realistically shaped physical torso phantom. A platinum dipole was inserted into the cylinder. The compartment boundaries were modelled with two special ionic exchange membranes. The conductivity ratio of the cylinder compartment to the torso compartment was varied from 0.25 to 100. We compared the simultaneously measured magnetic and electric signal strengths as a function of this conductivity ratio. We found that an increasing conductivity ratio causes only a slight increase (about 19%) of the magnetic signal strength but a strong decrease (about 81%) of the electric signal strength. Using a homogeneous torso model, the dipole localization errors were, depending on the conductivity ratio, up to 16 mm. In conclusion, passive vortex currents might partially explain the differences between magnetocardiographic and electrocardiographic recordings observed both experimentally and clinically.

  9. Ordering design tasks based on coupling strengths

    NASA Technical Reports Server (NTRS)

    Rogers, James L., Jr.; Bloebaum, Christina L.

    1994-01-01

    The design process associated with large engineering systems requires an initial decomposition of the complex system into modules of design tasks which are coupled through the transference of output data. In analyzing or optimizing such a coupled system, it is essential to be able to determine which interactions figure prominently enough to significantly affect the accuracy of the system solution. Many decomposition approaches assume the capability is available to determine what design tasks and interactions exist and what order of execution will be imposed during the analysis process. Unfortunately, this is often a complex problem and beyond the capabilities of a human design manager. A new feature for DeMAID (Design Manager's Aid for Intelligent Decomposition) will allow the design manager to use coupling strength information to find a proper sequence for ordering the design tasks. In addition, these coupling strengths aid in deciding if certain tasks or couplings could be removed (or temporarily suspended) from consideration to achieve computational savings without a significant loss of system accuracy. New rules are presented and two small test cases are used to show the effects of using coupling strengths in this manner.

  10. Ordering Design Tasks Based on Coupling Strengths

    NASA Technical Reports Server (NTRS)

    Rogers, J. L.; Bloebaum, C. L.

    1994-01-01

    The design process associated with large engineering systems requires an initial decomposition of the complex system into modules of design tasks which are coupled through the transference of output data. In analyzing or optimizing such a coupled system, it is essential to be able to determine which interactions figure prominently enough to significantly affect the accuracy of the system solution. Many decomposition approaches assume the capability is available to determine what design tasks and interactions exist and what order of execution will be imposed during the analysis process. Unfortunately, this is often a complex problem and beyond the capabilities of a human design manager. A new feature for DeMAID (Design Manager's Aid for Intelligent Decomposition) will allow the design manager to use coupling strength information to find a proper sequence for ordering the design tasks. In addition, these coupling strengths aid in deciding if certain tasks or couplings could be removed (or temporarily suspended) from consideration to achieve computational savings without a significant loss of system accuracy. New rules are presented and two small test cases are used to show the effects of using coupling strengths in this manner.

  11. Building a Strengths-Based Campus to Support Student Retention

    ERIC Educational Resources Information Center

    Soria, Krista M.; Stubblefield, Robin

    2015-01-01

    Strengths-based approaches are flourishing across hundreds of higher education institutions as student affairs practitioners and educators seek to leverage students' natural talents so they can reach "previously unattained levels of personal excellence" (Lopez & Louis, 2009, p. 2). Even amid the growth of strengths-based approaches…

  12. TCR Signal Strength Alters T–DC Activation and Interaction Times and Directs the Outcome of Differentiation

    PubMed Central

    van Panhuys, Nicholas

    2016-01-01

    The ability of CD4+ T cells to differentiate into effector subsets underpins their ability to shape the immune response and mediate host protection. During T cell receptor-induced activation of CD4+ T cells, both the quality and quantity of specific activatory peptide/MHC ligands have been shown to control the polarization of naive CD4+ T cells in addition to co-stimulatory and cytokine-based signals. Recently, advances in two-­photon microscopy and tetramer-based cell tracking methods have allowed investigators to greatly extend the study of the role of TCR signaling in effector differentiation under in vivo conditions. In this review, we consider data from recent in vivo studies analyzing the role of TCR signal strength in controlling the outcome of CD4+ T cell differentiation and discuss the role of TCR in controlling the critical nature of CD4+ T cell interactions with dendritic cells during activation. We further propose a model whereby TCR signal strength controls the temporal aspects of T–DC interactions and the implications for this in mediating the downstream signaling events, which influence the transcriptional and epigenetic regulation of effector differentiation. PMID:26834747

  13. Strength-Based Assessment for Children with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Cosden, Merith; Koegel, Lynn Kern; Koegel, Robert L.; Greenwell, Ashley; Klein, Eileen

    2006-01-01

    Despite improvements in interventions for children with autism, assessments tend to focus on their social, cognitive, and behavioral deficits, without similar systematic examination of their strengths. Strength-based assessment (SBA), which has been used in work with children with milder behavioral disorders, may also have value for individuals…

  14. High strength forgeable tantalum base alloy

    NASA Technical Reports Server (NTRS)

    Buckman, R. W., Jr.

    1975-01-01

    Increasing tungsten content of tantalum base alloy to 12-15% level will improve high temperature creep properties of existing tantalum base alloys while retaining their excellent fabrication and welding characteristics.

  15. Received signal strength recovery in green WLAN indoor positioning system using singular value thresholding.

    PubMed

    Ma, Lin; Xu, Yubin

    2015-01-01

    Green WLAN is a promising technique for accessing future indoor Internet services. It is designed not only for high-speed data communication purposes but also for energy efficiency. The basic strategy of green WLAN is that all the access points are not always powered on, but rather work on-demand. Though powering off idle access points does not affect data communication, a serious asymmetric matching problem will arise in a WLAN indoor positioning system due to the fact the received signal strength (RSS) readings from the available access points are different in their offline and online phases. This asymmetry problem will no doubt invalidate the fingerprint algorithm used to estimate the mobile device location. Therefore, in this paper we propose a green WLAN indoor positioning system, which can recover RSS readings and achieve good localization performance based on singular value thresholding (SVT) theory. By solving the nuclear norm minimization problem, SVT recovers not only the radio map, but also online RSS readings from a sparse matrix by sensing only a fraction of the RSS readings. We have implemented the method in our lab and evaluated its performances. The experimental results indicate the proposed system could recover the RSS readings and achieve good localization performance.

  16. Early-age concrete strength estimation based on piezoelectric sensor using artificial neural network

    NASA Astrophysics Data System (ADS)

    Kim, Junkyeong; Kim, Ju-Won; Park, Seunghee

    2014-04-01

    Recently, novel methods to estimate the strength of concrete have been reported based on numerous NDT methods. Especially, electro-mechanical impedance technique using piezoelectric sensors are studied to estimate the strength of concrete. However, the previous research works could not provide the general information about the early-age strength important to manage the quality of concrete and/or the construction process. In order to estimate the early-age strength of concrete, the electro-mechanical impedance method and the artificial neural network(ANN) is utilized in this study. The electro-mechanical impedance varies with the mechanical properties of host structures. Because the strength development is most influential factor among the change of mechanical properties at early-age of curing, it is possible to estimate the strength of concrete by analyzing the change of E/M impedance. The strength of concrete is a complex function of several factors like mix proportion, temperature, elasticity, etc. Because of this, it is hard to mathematically derive equations about strength of concrete. The ANN can provide the solution about early-age strength of concrete without mathematical equations. To verify the proposed approach, a series of experimental studies are conducted. The impedance signals are measured using embedded piezoelectric sensors during curing process and the resonant frequency of impedance is extracted as a strength feature. The strength of concrete is calculated by regression of strength development curve obtained by destructive test. Then ANN model is established by trained using experimental results. Finally the ANN model is verified using impedance data of other sensors.

  17. Correlation theory-based signal processing method for CMF signals

    NASA Astrophysics Data System (ADS)

    Shen, Yan-lin; Tu, Ya-qing

    2016-06-01

    Signal processing precision of Coriolis mass flowmeter (CMF) signals affects measurement accuracy of Coriolis mass flowmeters directly. To improve the measurement accuracy of CMFs, a correlation theory-based signal processing method for CMF signals is proposed, which is comprised of the correlation theory-based frequency estimation method and phase difference estimation method. Theoretical analysis shows that the proposed method eliminates the effect of non-integral period sampling signals on frequency and phase difference estimation. The results of simulations and field experiments demonstrate that the proposed method improves the anti-interference performance of frequency and phase difference estimation and has better estimation performance than the adaptive notch filter, discrete Fourier transform and autocorrelation methods in terms of frequency estimation and the data extension-based correlation, Hilbert transform, quadrature delay estimator and discrete Fourier transform methods in terms of phase difference estimation, which contributes to improving the measurement accuracy of Coriolis mass flowmeters.

  18. Measuring the target strength spectra of fish using dolphin-like short broadband sonar signals.

    PubMed

    Imaizumi, Tomohito; Furusawa, Masahiko; Akamatsu, Tomonari; Nishimori, Yasushi

    2008-12-01

    Dolphins identify their prey using broadband sonar signals. The broadband spectrum of the target strength (TS) of fish is believed to be a key factor in target discrimination. In this study, the TS spectrum was measured using sonar signals generated by two different dolphin species: finless porpoise and bottlenose dolphin. First, the broadband form functions of a tungsten carbide sphere and a copper sphere were measured in a water tank, and a close agreement between measurements and theoretical values was confirmed. Second, the TS spectra of anesthetized fish from three species were measured in a water tank. Although the results showed characteristics similar to previous measurements, they varied among species, individuals, and tilt angles. Third, the TS spectra of live fish suspended and tethered by nylon monofilament lines were measured at sea. The dolphin-like sonar signals were effective in obtaining the broadband TS spectra of the fish. Cross-correlation processing of the echo from a tungsten carbide sphere showed a further advantage of using the dolphin-like sonar signals: the signal-to-noise ratio increased by more than 10 dB. The variation of TS spectra with fish behavior provides useful information for target identification.

  19. [Development of Muscle Strength Evaluating System Based on Mobile Platform].

    PubMed

    Xu, Xiulin; Yao, Xiaoming; Xu, Xijiao; Hu, Xiaohui

    2015-08-01

    The development of muscle strength evaluating system based on Android system was developed in this research. The system consists of a lower unit and an intelligent mobile terminal. The pressure sensor of the lower unit was used to collect muscle strength parameters. And the parameters were sent to the Android device through the wireless Bluetooth serial port. Then the Android device would send the parameters to the doctor monitored platform through the Internet. The system realized analyzing the muscle strength parameters and real-time displaying them. After it ran on the Android mobile phones, it showed an effective result which proved that the system combined with mobile platform could make more convenient for the patients to assess their own muscle strength. It also provided reliable data references for doctors to know the patients' rehabilitation condition and to make the next rehabilitation plan. PMID:26710452

  20. Fourier-based strength homogenization of porous media

    NASA Astrophysics Data System (ADS)

    Bignonnet, François; Hassen, Ghazi; Dormieux, Luc

    2016-11-01

    An efficient numerical method is proposed to upscale the strength properties of heterogeneous media with periodic boundary conditions. The method relies on a formal analogy between strength homogenization and non-linear elasticity homogenization. The non-linear problems are solved on a regular discretization grid using the Augmented Lagrangian version of Fast Fourier Transform based schemes initially introduced for elasticity upscaling. The method is implemented for microstructures with local strength properties governed either by a Green criterion or a Von Mises criterion, including pores or rigid inclusions. A thorough comparison with available analytical results or finite element elasto-plastic simulations is proposed to validate the method on simple microstructures. As an application, the strength of complex microstructures such as the random Boolean model of spheres is then studied, including a comparison to closed-form Gurson and Eshelby based strength estimates. The effects of the microstructure morphology and the third invariant of the macroscopic stress tensor on the homogenized strength are quantitatively discussed.

  1. Fourier-based strength homogenization of porous media

    NASA Astrophysics Data System (ADS)

    Bignonnet, François; Hassen, Ghazi; Dormieux, Luc

    2016-07-01

    An efficient numerical method is proposed to upscale the strength properties of heterogeneous media with periodic boundary conditions. The method relies on a formal analogy between strength homogenization and non-linear elasticity homogenization. The non-linear problems are solved on a regular discretization grid using the Augmented Lagrangian version of Fast Fourier Transform based schemes initially introduced for elasticity upscaling. The method is implemented for microstructures with local strength properties governed either by a Green criterion or a Von Mises criterion, including pores or rigid inclusions. A thorough comparison with available analytical results or finite element elasto-plastic simulations is proposed to validate the method on simple microstructures. As an application, the strength of complex microstructures such as the random Boolean model of spheres is then studied, including a comparison to closed-form Gurson and Eshelby based strength estimates. The effects of the microstructure morphology and the third invariant of the macroscopic stress tensor on the homogenized strength are quantitatively discussed.

  2. Concurrent Validity of the Strength-Based "Behavioral Objective Sequence"

    ERIC Educational Resources Information Center

    Wilder, Lynn K.; Braaten, Sheldon; Wilhite, Kathi; Algozzine, Bob

    2006-01-01

    An essential task of diagnosticians is the accurate assessment of behavioral skills. Traditionally, deficit-based behavioral assessments have underscored student social skill deficits. Strength-based assessments delineate student competencies and are useful for individualized education program (IEP) and behavioral intervention plan (BIP)…

  3. Strengths-Based Advising: A New Lens for Higher Education

    ERIC Educational Resources Information Center

    Schreiner, Laurie; Anderson, Edward

    2005-01-01

    Strengths-based advising is proposed as a new lens for higher education, one that enables advisors to see diverse groups of students fulfill their potential and achieve excellence. Based on research from social work, positive psychology, and the business world, this approach enables advisors to identify and build on the inherent talents students…

  4. A Strength-Based Approach to Teacher Professional Development

    ERIC Educational Resources Information Center

    Zwart, Rosanne C.; Korthagen, Fred A. J.; Attema-Noordewier, Saskia

    2015-01-01

    Based on positive psychology, self-determination theory and a perspective on teacher quality, this study proposes and examines a strength-based approach to teacher professional development. A mixed method pre-test/post-test design was adopted to study perceived outcomes of the approach for 93 teachers of six primary schools in the Netherlands and…

  5. Which strengths-based practice? Reconciling strengths-based practice and mandated authority in child protection work.

    PubMed

    Oliver, Carolyn; Charles, Grant

    2015-04-01

    The recent application of strengths-based practice in child protection settings has been accompanied by evidence of inconsistent implementation and concerns that the approach is incompatible with statutory work. Few studies have moved beyond asking whether child protection workers are implementing strengths-based practice to explore why the approach is enacted as it is. This article describes a mixed methods study using an online survey and interviews to elicit from 225 statutory child protection workers in a large Canadian agency how they applied strengths-based ideas and why they did what they did. The authors found that although strengths-based practice was popular, 70 percent of participants believed that it was not always applicable to child protection work. Participants described five distinct versions of the approach, only one of which was fully congruent with their mandated role. The study suggests that the common conflation of strengths-based and solution-focused approaches ignores important differences in the conceptualization of practitioner authority and leaves practitioners attempting to implement versions ofstrengths-based practice that do not fit statutory child protection work. Only when practitioners choose solution-focused models that support their use of mandated authority is consistent implementation a reasonable expectation.

  6. Design and evaluation of a wireless sensor network based aircraft strength testing system.

    PubMed

    Wu, Jian; Yuan, Shenfang; Zhou, Genyuan; Ji, Sai; Wang, Zilong; Wang, Yang

    2009-01-01

    The verification of aerospace structures, including full-scale fatigue and static test programs, is essential for structure strength design and evaluation. However, the current overall ground strength testing systems employ a large number of wires for communication among sensors and data acquisition facilities. The centralized data processing makes test programs lack efficiency and intelligence. Wireless sensor network (WSN) technology might be expected to address the limitations of cable-based aeronautical ground testing systems. This paper presents a wireless sensor network based aircraft strength testing (AST) system design and its evaluation on a real aircraft specimen. In this paper, a miniature, high-precision, and shock-proof wireless sensor node is designed for multi-channel strain gauge signal conditioning and monitoring. A cluster-star network topology protocol and application layer interface are designed in detail. To verify the functionality of the designed wireless sensor network for strength testing capability, a multi-point WSN based AST system is developed for static testing of a real aircraft undercarriage. Based on the designed wireless sensor nodes, the wireless sensor network is deployed to gather, process, and transmit strain gauge signals and monitor results under different static test loads. This paper shows the efficiency of the wireless sensor network based AST system, compared to a conventional AST system. PMID:22408521

  7. Digital Signal Processing Based Biotelemetry Receivers

    NASA Technical Reports Server (NTRS)

    Singh, Avtar; Hines, John; Somps, Chris

    1997-01-01

    This is an attempt to develop a biotelemetry receiver using digital signal processing technology and techniques. The receiver developed in this work is based on recovering signals that have been encoded using either Pulse Position Modulation (PPM) or Pulse Code Modulation (PCM) technique. A prototype has been developed using state-of-the-art digital signal processing technology. A Printed Circuit Board (PCB) is being developed based on the technique and technology described here. This board is intended to be used in the UCSF Fetal Monitoring system developed at NASA. The board is capable of handling a variety of PPM and PCM signals encoding signals such as ECG, temperature, and pressure. A signal processing program has also been developed to analyze the received ECG signal to determine heart rate. This system provides a base for using digital signal processing in biotelemetry receivers and other similar applications.

  8. Bond strength with custom base indirect bonding techniques.

    PubMed

    Klocke, Arndt; Shi, Jianmin; Kahl-Nieke, Bärbel; Bismayer, Ulrich

    2003-04-01

    Different types of adhesives for indirect bonding techniques have been introduced recently. But there is limited information regarding bond strength with these new materials. In this in vitro investigation, stainless steel brackets were bonded to 100 permanent bovine incisors using the Thomas technique, the modified Thomas technique, and light-cured direct bonding for a control group. The following five groups of 20 teeth each were formed: (1) modified Thomas technique with thermally cured base composite (Therma Cure) and chemically cured sealant (Maximum Cure), (2) Thomas technique with thermally cured base composite (Therma Cure) and chemically cured sealant (Custom I Q), (3) Thomas technique with light-cured base composite (Transbond XT) and chemically cured sealant (Sondhi Rapid Set), (4) modified Thomas technique with chemically cured base adhesive (Phase II) and chemically cured sealant (Maximum Cure), and (5) control group directly bonded with light-cured adhesive (Transbond XT). Mean bond strengths in groups 3, 4, and 5 were 14.99 +/- 2.85, 15.41 +/- 3.21, and 13.88 +/- 2.33 MPa, respectively, and these groups were not significantly different from each other. Groups 1 (mean bond strength 7.28 +/- 4.88 MPa) and 2 (mean bond strength 7.07 +/- 4.11 MPa) showed significantly lower bond strengths than groups 3, 4, and 5 and a higher probability of bond failure. Both the original (group 2) and the modified (group 1) Thomas technique were able to achieve bond strengths comparable to the light-cured direct bonded control group.

  9. Inferring strength and deformation properties of hot mix asphalt layers from the GPR signal: recent advances

    NASA Astrophysics Data System (ADS)

    Tosti, Fabio; Benedetto, Andrea; Bianchini Ciampoli, Luca; Adabi, Saba; Pajewski, Lara

    2015-04-01

    The great flexibility of ground-penetrating radar has led to consider worldwide this instrument as an effective and efficient geophysical tool in several fields of application. As far as pavement engineering is concerned, ground-penetrating radar is employed in a wide range of applications, including physical and geometrical evaluation of road pavements. Conversely, the mechanical characterization of pavements is generally inferred through traditional (e.g., plate bearing test method) or advanced non-destructive techniques (e.g., falling weight deflectometer). Nevertheless, measurements performed using these methods, inevitably turn out to be both much more time-consuming and low-significant whether compared with ground-penetrating radar's potentials. In such a framework, a mechanical evaluation directly coming from electromagnetic inspections could represent a real breakthrough in the field of road assets management. With this purpose, a ground-penetrating radar system with 600 MHz and 1600 MHz center frequencies of investigation and ground-coupled antennas was employed to survey a 4m×30m flexible pavement test site. The test area was marked by a regular grid mesh of 836 nodes, respectively spaced by a distance of 0.40 m alongside the horizontal and vertical axes. At each node, the elastic modulus was measured using a light falling weight deflectometer. Data processing has provided to reconstruct a 3-D matrix of amplitudes for the surveyed area, considering a depth of around 300 mm, in accord to the influence domain of the light falling weight deflectometer. On the other hand, deflectometric data were employed for both calibration and validation of a semi-empirical model by relating the amplitude of signal reflections through the media along fixed depths within the depth domain considered, and the Young's modulus of the pavement at the evaluated point. This statistically-based model is aimed at continuously taking into account alongside the depth of investigation

  10. Strength-Based Assessment: A Triad of Troubles

    ERIC Educational Resources Information Center

    Tate, Tom

    2010-01-01

    Traditional diagnosis treats behavior problems as "disorders" in the individual rather than "discord" in relationships. From an ecological perspective, a "problem" involves behavior that hurts self or others. Three global patterns of problems are: Inconsiderate of Others, Inconsiderate of Self, and Low Self-Worth. Strength-based assessment…

  11. The Colorful Evolution of a Strength-Based Treatment Model

    ERIC Educational Resources Information Center

    Quigley, Richard

    2003-01-01

    For more than 50 years, adolescent peer group treatment has been both glorified and criticized. Quality control has been a problem for the Positive Peer Culture (PPC) treatment modality throughout its history. The following article includes observations and commentary on the history, strength-based elements, and criticism of PPC.

  12. Bringing Strength-Based Philosophy to Life in Juvenile Justice

    ERIC Educational Resources Information Center

    Nissen, Laura

    2006-01-01

    The strength-based approach is an organizing principle for a family of theories and practice strategies that encourage helping professionals to seek out clients' abilities, resources, and gifts and apply them to current life challenges. Despite its successful use in many human service sectors, this approach has not been embraced in the juvenile…

  13. School-Based Sexuality Education in Portugal: Strengths and Weaknesses

    ERIC Educational Resources Information Center

    Rocha, Ana Cristina; Leal, Cláudia; Duarte, Cidália

    2016-01-01

    Portugal, like many other countries, faces obstacles regarding school-based sexuality education. This paper explores Portuguese schools' approaches to implementing sexuality education at a local level, and provides a critical analysis of potential strengths and weaknesses. Documents related to sexuality education in a convenience sample of 89…

  14. Strength-Based Efforts for Promoting Recovery from Psychological Harm

    ERIC Educational Resources Information Center

    De Civita, Mirella

    2006-01-01

    Much resilience research highlights protective factors that prevent risk. Here the author focuses on resilience as the ability to recover from psychological harm. The strength-based view sees resilience as a transformational experience. One applicant of this approach is the Phoenix Intervention Program for Children (PIPC) which combines concepts…

  15. Strength-Based Treatment for Juvenile Sexual Offenders.

    ERIC Educational Resources Information Center

    Marquoit, James; Dobbins, Martha

    1998-01-01

    Describes an alternative treatment model developed at Starr Commonwealth for sexually reactive and offending children and youth. This model's strength-based interventions have been shown to be effective in fostering positive connections to adults and peers and in breaking patterns of offending. (Author/MKA)

  16. Bond strength of denture teeth to acrylic bases.

    PubMed

    Cunningham, J L

    1993-10-01

    The literature relating to the determination of the bond strength of plastic denture teeth to acrylic resin denture material is reviewed. The papers are presented in chronological order with information on specimen preparation, batch sizes and methods of testing. The lack of uniformity in experimental techniques and the diverse range of products assessed makes recommendations for laboratory practice difficult to formulate. One consistent observation is that tooth surface contamination with wax decreases the bond strength between the teeth and the denture base material. A universal testing method needs to be formulated to replace the various techniques now employed.

  17. Using received signal strength indicator to detect node replacement and replication attacks in wireless sensor networks

    NASA Astrophysics Data System (ADS)

    Hussain, Sajid; Rahman, Md Shafayat

    2009-04-01

    With the advent of powerful and efficient wireless sensor nodes, the usage of wireless sensor networks (WSNs) has been greatly increased. However, various kinds of security breaches have also been introduced, which exposes the vulnerability of these nodes to defend the valuable data from some specific types of attacks. In this paper, we address node replication, replacement, and man-in-the-middle attacks. We analyze the feasibility of using received signal strength indicator (RSSI) values measured at the receiver node to detect these kinds of attacks. As RSSI value is readily available for every message received by a node, a successful utilization of this information in security breach detection can be a very important contribution.

  18. Where did my wifi go? Measuring soil moisture using wifi signal strength

    NASA Astrophysics Data System (ADS)

    Hut, Rolf; de Jeu, Richard

    2015-04-01

    Soil moisture is tricky to measure. Currently soil moisture is measured at small footprints using probes and other field devices, or at large footprints using satellites. Promising developments in measuring soil moisture are using fiber optic cables for measurements along a line, or using cosmos rays for field scale measurements. In this demonstration we present a low cost alternative to measure soil moisture at footprints of a few square meters. We use a wifi hotspot and a wifi dongle, both mounted in a cantenna for beam forming. We aim the hotspot on a piece of soil and put the dongle in the path of the reflection. By logging the signal strength of the wifi netwerk, we have a proxy for soil moisture. A first proof of concept is presented.

  19. Implementing paraprofessional strength-based early intervention home visitations.

    PubMed

    Mykota, David B

    2008-08-01

    The purpose of the present study is to evaluate the implementation process for Parenting Plus, an early intervention program in a rural, western Canadian health district. Parenting Plus, as modeled after Hawaii Healthy Start, provides strength-based paraprofessional home visitations to overburdened parents of newborns. The general inductive approach guided the studies design and the methods used for data collection and analysis. Semi-structured in-depth interviews were conducted with health care practitioners and focus groups with program participants were held until theoretical saturation was achieved for both. Recommendations for policy and practice address the need for intersectoral involvement as crucial to a strength-based pilot project's success. Future research needs not only to look at the mode of service delivery but also, more importantly, at how the characteristics of the home visitor can effect change in the participant and what level of experience or education (paraprofessional or professional) is best suited to a particular client population. PMID:18502507

  20. Metal extraction from road sediment using different strength reagents: impact on anthropogenic contaminant signals.

    PubMed

    Sutherland, R A; Tack, F M; Tolosa, C A; Verloo, M G

    2001-10-01

    Washoff of road deposited sediment into storm drain systems is one of the major contributors to nonpoint source pollution in urban fluvial networks. These sediments contain a variety of potentially toxic organic and inorganic contaminants. Road sediment from 13 locations in an urban (non-industrialized) drainage basin, and soil from 10 background (control) locations were collected to assess total and labile fractions of Al, Co, Cu, Fe, Mn, Ni, Pb and Zn. Four digestions, of varying strength, were used to assess contaminant levels, these included: a total four-acid digestion, a microwave-assisted digestion with concentrated nitric acid (USEPA Method 3051), a 0.5 M 'cold' HCl, and a 0.05 M EDTA (pH 7). Road sediment data indicate that Al, Co, Fe, Mn and Ni were primarily lithogenic in origin, while Cu, Pb and Zn showed very significant anthropogenic signals, most probably from vehicle-related sources. Median Pb concentration enrichment ratios for the EDTA extraction were about 42, indicating an extreme anthropogenic signal. The weak extractants (HCI and EDTA) are considered in this study to be superior in their ability to characterize the degree of anthropogenic contamination and should be utilized more widely in environmental contaminant studies.

  1. Enhancement of neuromuscular dynamics and strength behavior using extremely low magnitude mechanical signals in mice.

    PubMed

    Mettlach, Gabriel; Polo-Parada, Luis; Peca, Lauren; Rubin, Clinton T; Plattner, Florian; Bibb, James A

    2014-01-01

    Exercise in general, and mechanical signals in particular, help ameliorate the neuromuscular symptoms of aging and possibly other neurodegenerative disorders by enhancing muscle function. To better understand the salutary mechanisms of such physical stimuli, we evaluated the potential for low intensity mechanical signals to promote enhanced muscle dynamics. The effects of daily brief periods of low intensity vibration (LIV) on neuromuscular functions and behavioral correlates were assessed in mice. Physiological analysis revealed that LIV increased isometric force production in semitendinosus skeletal muscle. This effect was evident in both young and old mice. Isometric force recordings also showed that LIV reduced the fatiguing effects of intensive synaptic muscle stimulation. Furthermore, LIV increased evoked neurotransmitter release at neuromuscular synapses but had no effect on spontaneous end plate potential amplitude or frequency. In behavioral studies, LIV increased mouse grip strength and potentiated initial motor activity in a novel environment. These results provide evidence for the efficacy of LIV in producing changes in the neuromuscular system that translate into performance gains at a behavioral scale.

  2. SSL: Signal Similarity-Based Localization for Ocean Sensor Networks

    PubMed Central

    Chen, Pengpeng; Ma, Honglu; Gao, Shouwan; Huang, Yan

    2015-01-01

    Nowadays, wireless sensor networks are often deployed on the sea surface for ocean scientific monitoring. One of the important challenges is to localize the nodes’ positions. Existing localization schemes can be roughly divided into two types: range-based and range-free. The range-based localization approaches heavily depend on extra hardware capabilities, while range-free ones often suffer from poor accuracy and low scalability, far from the practical ocean monitoring applications. In response to the above limitations, this paper proposes a novel signal similarity-based localization (SSL) technology, which localizes the nodes’ positions by fully utilizing the similarity of received signal strength and the open-air characteristics of the sea surface. In the localization process, we first estimate the relative distance between neighboring nodes through comparing the similarity of received signal strength and then calculate the relative distance for non-neighboring nodes with the shortest path algorithm. After that, the nodes’ relative relation map of the whole network can be obtained. Given at least three anchors, the physical locations of nodes can be finally determined based on the multi-dimensional scaling (MDS) technology. The design is evaluated by two types of ocean experiments: a zonal network and a non-regular network using 28 nodes. Results show that the proposed design improves the localization accuracy compared to typical connectivity-based approaches and also confirm its effectiveness for large-scale ocean sensor networks. PMID:26610520

  3. Finding significantly connected voxels based on histograms of connection strengths

    NASA Astrophysics Data System (ADS)

    Kasenburg, Niklas; Pedersen, Morten Vester; Darkner, Sune

    2016-03-01

    We explore a new approach for structural connectivity based segmentations of subcortical brain regions. Connectivity based segmentations are usually based on fibre connections from a seed region to predefined target regions. We present a method for finding significantly connected voxels based on the distribution of connection strengths. Paths from seed voxels to all voxels in a target region are obtained from a shortest-path tractography. For each seed voxel we approximate the distribution with a histogram of path scores. We hypothesise that the majority of estimated connections are false-positives and that their connection strength is distributed differently from true-positive connections. Therefore, an empirical null-distribution is defined for each target region as the average normalized histogram over all voxels in the seed region. Single histograms are then tested against the corresponding null-distribution and significance is determined using the false discovery rate (FDR). Segmentations are based on significantly connected voxels and their FDR. In this work we focus on the thalamus and the target regions were chosen by dividing the cortex into a prefrontal/temporal zone, motor zone, somatosensory zone and a parieto-occipital zone. The obtained segmentations consistently show a sparse number of significantly connected voxels that are located near the surface of the anterior thalamus over a population of 38 subjects.

  4. Burst Strength of Tubing and Casing Based on Twin Shear Unified Strength Theory

    PubMed Central

    Lin, Yuanhua; Deng, Kuanhai; Sun, Yongxing; Zeng, Dezhi; Liu, Wanying; Kong, Xiangwei; Singh, Ambrish

    2014-01-01

    The internal pressure strength of tubing and casing often cannot satisfy the design requirements in high pressure, high temperature and high H2S gas wells. Also, the practical safety coefficient of some wells is lower than the design standard according to the current API 5C3 standard, which brings some perplexity to the design. The ISO 10400: 2007 provides the model which can calculate the burst strength of tubing and casing better than API 5C3 standard, but the calculation accuracy is not desirable because about 50 percent predictive values are remarkably higher than real burst values. So, for the sake of improving strength design of tubing and casing, this paper deduces the plastic limit pressure of tubing and casing under internal pressure by applying the twin shear unified strength theory. According to the research of the influence rule of yield-to-tensile strength ratio and mechanical properties on the burst strength of tubing and casing, the more precise calculation model of tubing-casing's burst strength has been established with material hardening and intermediate principal stress. Numerical and experimental comparisons show that the new burst strength model is much closer to the real burst values than that of other models. The research results provide an important reference to optimize the tubing and casing design of deep and ultra-deep wells. PMID:25397886

  5. Advanced nickel base alloys for high strength, corrosion applications

    DOEpatents

    Flinn, John E.

    1998-01-01

    Improved nickel-base alloys of enhanced strength and corrosion resistance, produced by atomization of an alloy melt under an inert gas atmosphere and of composition 0-20Fe, 10-30Cr, 2-12Mo, 6 max. Nb, 0.05-3 V, 0.08 max. Mn, 0.5 max. Si, less than 0.01 each of Al and Ti, less than 0.05 each of P and S, 0.01-0.08C, less than 0.2N, 0.1 max. 0, bal. Ni.

  6. Advanced nickel base alloys for high strength, corrosion applications

    DOEpatents

    Flinn, J.E.

    1998-11-03

    Improved nickel-base alloys of enhanced strength and corrosion resistance, produced by atomization of an alloy melt under an inert gas atmosphere and of composition 0--20Fe, 10--30Cr, 2--12Mo, 6 max. Nb, 0.05--3 V, 0.08 max. Mn, 0.5 max. Si, less than 0.01 each of Al and Ti, less than 0.05 each of P and S, 0.01--0.08C, less than 0.2N, 0.1 max. 0, bal. Ni. 3 figs.

  7. Qualitatively Different T Cell Phenotypic Responses to IL-2 versus IL-15 are Unified by Identical Dependences on Receptor Signal Strength and Duration

    PubMed Central

    Arneja, Abhinav; Johnson, Hannah; Gabrovsek, Laura; Lauffenburger, Douglas A.; White, Forest M.

    2014-01-01

    Interleukin 2 (IL-2) and Interleukin 15 (IL-15) are common γ-chain family cytokines involved in regulation of T cell differentiation and homeostasis. Despite signaling through the same receptors, IL-2 and IL-15 have non-redundant roles in T cell biology, both physiologically and at the cellular level. The mechanisms by which IL-2 and IL-15 trigger distinct phenotypes in T cells remain elusive. To elucidate these mechanisms, we performed a quantitative comparison of the phosphotyrosine signaling network and resulting phenotypes triggered by IL-2 and IL-15. This study revealed that the signaling networks activated by IL-2 or IL-15 are highly similar and that T cell proliferation and metabolism are controlled in a quantitatively distinct manner through IL-2/15 receptor signal strength independent of the cytokine identity. Distinct phenotypes associated with IL-2 or IL-15 stimulation therefore arise through differential regulation of IL-2/15R signal strength and duration due to differences in cytokine-receptor binding affinity, receptor expression levels, physiological cytokine levels, and cytokine-receptor intracellular trafficking kinetics. These results provide important insights into the function of other shared cytokine and growth factor receptors, quantitative regulation of cell proliferation and metabolism through signal transduction, and improved design of cytokine based clinical immunomodulatory therapies for cancer and infectious diseases. PMID:24298013

  8. Strength-based crisis programming: Evaluating the process of care.

    PubMed

    Hootz, Terra; Mykota, David B; Fauchoux, Laurissa

    2016-02-01

    In this study, a utilization-focused process evaluation framework was used to explore client and service providers' experiences of Crisis Management Services (CMS), their perceptions of the services provided, and the process of client engagement CMS offers. CMS is a strength-based program that targets individuals who experience crises every day. The Community-University Institute for Social Research facilitated the evaluation by engaging academic expertise in a coordinated collaborative approach to community-university partnerships. Semi-structured interviews were conducted with the clients and service providers. The general inductive approach was used for transcript analysis with seven themes emerging. A conceptual model of service delivery is presented, which integrates the interviews conducted with clients and service providers. Results affirm that the establishment of a close personal strength-based relationship is key to client engagement. Collaborative goal setting with informal and formal community resources viewed as potential assets, characterizes the process that enables clients to live at their optimal level of independence. This study is unique as it provides valuable insight on the perspectives of vulnerable individuals in crisis situations. Through the establishment of community-university partnerships the gap between scholarly research and its applicability to community organizations is narrowed with opportunities for improving the quality of life enhanced. PMID:26512431

  9. Strength-based crisis programming: Evaluating the process of care.

    PubMed

    Hootz, Terra; Mykota, David B; Fauchoux, Laurissa

    2016-02-01

    In this study, a utilization-focused process evaluation framework was used to explore client and service providers' experiences of Crisis Management Services (CMS), their perceptions of the services provided, and the process of client engagement CMS offers. CMS is a strength-based program that targets individuals who experience crises every day. The Community-University Institute for Social Research facilitated the evaluation by engaging academic expertise in a coordinated collaborative approach to community-university partnerships. Semi-structured interviews were conducted with the clients and service providers. The general inductive approach was used for transcript analysis with seven themes emerging. A conceptual model of service delivery is presented, which integrates the interviews conducted with clients and service providers. Results affirm that the establishment of a close personal strength-based relationship is key to client engagement. Collaborative goal setting with informal and formal community resources viewed as potential assets, characterizes the process that enables clients to live at their optimal level of independence. This study is unique as it provides valuable insight on the perspectives of vulnerable individuals in crisis situations. Through the establishment of community-university partnerships the gap between scholarly research and its applicability to community organizations is narrowed with opportunities for improving the quality of life enhanced.

  10. Fetal QRS extraction from abdominal recordings via model-based signal processing and intelligent signal merging.

    PubMed

    Haghpanahi, Masoumeh; Borkholder, David A

    2014-08-01

    Noninvasive fetal ECG (fECG) monitoring has potential applications in diagnosing congenital heart diseases in a timely manner and assisting clinicians to make more appropriate decisions during labor. However, despite advances in signal processing and machine learning techniques, the analysis of fECG signals has still remained in its preliminary stages. In this work, we describe an algorithm to automatically locate QRS complexes in noninvasive fECG signals obtained from a set of four electrodes placed on the mother's abdomen. The algorithm is based on an iterative decomposition of the maternal and fetal subspaces and filtering of the maternal ECG (mECG) components from the fECG recordings. Once the maternal components are removed, a novel merging technique is applied to merge the signals and detect the fetal QRS (fQRS) complexes. The algorithm was trained and tested on the fECG datasets provided by the PhysioNet/CinC challenge 2013. The final results indicate that the algorithm is able to detect fetal peaks for a variety of signals with different morphologies and strength levels encountered in clinical practice.

  11. Does a Social Work Degree Predict Practice Orientation? Measuring Strengths-Based Practice among Child Welfare Workers with the Strengths-Based Practices Inventory-Provider Version

    ERIC Educational Resources Information Center

    Douglas, Emily M.; McCarthy, Sean C.; Serino, Patricia A.

    2014-01-01

    Strengths-based practice (SBP) is one of the primary modalities of social work practice. The literature on SBP does not address a standardized tool for measuring SBP or whether receipt of a social work degree is related to practice orientation. We measure SBP with a provider-based Strengths-Based Practices Inventory (SBPI-P) and examine whether a…

  12. Satellite based Global Flood Detection System - strengths and limitations

    NASA Astrophysics Data System (ADS)

    Revilla-Romero, Beatriz; Salamon, Peter; Thielen, Jutta; De Groeve, Tom; Zajac, Zuzanna

    2014-05-01

    One of the main problems for global hydrological models is that for many regions only very limited or no observational data for a model assessment is available. This problem could be overcome with filling the gaps using information derived from satellite observations. Thus, an evaluation of the remote sensing signal of the Global Flood Detection System (GFDS) against observed discharge data was performed in order to test the use of this data in sparsely gauged river basins. The study was carried out at 398 locations near the main rivers and in Africa, Asia, Europe, North America and South America. After evaluating different methodologies for extracting the satellite signal, a temporal (4 days) and spatial (4 GFDS pixels) average was chosen to proceed with the analysis. For the 340 stations with a concurrent time series longer than seven years for both, the signal and the in situ observed discharge (obtained mainly from the Global Runoff Data Centre), a calibration based on monthly linear models was carried out. The validation was executed and several skill scores were calculated such as the R2, Nash-Sutcliffe (NSE), and Root Mean Square Error (RMSE). It is important to highlight that, for this study, 230 stations globally had Nash-Sutcliffe efficient score higher than zero, indicating that for specific conditions the satellite signal as used in GFDS can fill the gaps where observations are not available. For example, several locations in African catchments have good performance as in the Niger, Volta and Zambezi for which Nash-Sutcliffe is greater than 0.75. It is known that a number of factors affect total upwelling microwave brightness from a mixed water and land surface measured by a single image pixel. Aiming to better understand how some features of the sites could affect the satellite signal and the correlation with in situ observations, apart from the dependency on the river geometry, a multivariate analysis was carried out between the skill scores (NSE and

  13. Development of an empirically based dynamic biomechanical strength model

    NASA Technical Reports Server (NTRS)

    Pandya, A.; Maida, J.; Aldridge, A.; Hasson, S.; Woolford, B.

    1992-01-01

    The focus here is on the development of a dynamic strength model for humans. Our model is based on empirical data. The shoulder, elbow, and wrist joints are characterized in terms of maximum isolated torque, position, and velocity in all rotational planes. This information is reduced by a least squares regression technique into a table of single variable second degree polynomial equations determining the torque as a function of position and velocity. The isolated joint torque equations are then used to compute forces resulting from a composite motion, which in this case is a ratchet wrench push and pull operation. What is presented here is a comparison of the computed or predicted results of the model with the actual measured values for the composite motion.

  14. Positive Psychology and Character Strengths: Application to Strengths-Based School Counseling

    ERIC Educational Resources Information Center

    Park, Nansook; Peterson, Christopher

    2008-01-01

    The basic premise of positive psychology is that the happiness and fulfillment of children and youth entail more than the identification and treatment of their problems. This article provides an overview of positive psychology and the Values in Action (VIA) project that classifies and measures 24 widely recognized character strengths. Good…

  15. African American adolescents' academic persistence: a strengths-based approach.

    PubMed

    Butler-Barnes, Sheretta T; Chavous, Tabbye M; Hurd, Noelle; Varner, Fatima

    2013-09-01

    African American adolescents are faced with the challenge to be successful academically, even though they may experience racial discrimination within school settings. Unfortunately, relatively little scholarship explores how African American adolescents draw on personal and cultural assets to persist and thrive in the face of discriminatory experiences. Additionally, little research has explored the buffering role of assets (e.g., racial pride, self-efficacy, and self-acceptance) on the relationship between school-based racial discriminatory experiences and the academic persistence of African American adolescents. Participants in the current study included 220 (58 % girls) socioeconomically diverse African American adolescents. Latent class analysis was utilized to identify clusters based on participants' racial pride, self-efficacy, and self-acceptance. Three cluster groups were identified. The majority of the students belonged to the average group in which adolescents reported average levels of the three study assets. Adolescents in the higher group reported higher assets relative to their peers in the study and those in the lower group reported lower strength-based assets relative to their peers. Results indicated that school-based racial discrimination was associated with lower levels of academic persistence. Additionally, adolescents in the higher assets group reported higher academic persistence in comparison to the average and low group. Our model reflected a promotive but not protective influence of adolescents' assets on their academic persistence.

  16. Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training

    PubMed Central

    Roberts, Llion A; Raastad, Truls; Markworth, James F; Figueiredo, Vandre C; Egner, Ingrid M; Shield, Anthony; Cameron-Smith, David; Coombes, Jeff S; Peake, Jonathan M

    2015-01-01

    two treatments on hypertrophy signalling pathways and satellite cell activity in skeletal muscle after acute strength exercise. Cold water immersion attenuated long term gains in muscle mass and strength. It also blunted the activation of key proteins and satellite cells in skeletal muscle up to 2 days after strength exercise. Individuals who use strength training to improve athletic performance, recover from injury or maintain their health should therefore reconsider whether to use cold water immersion as an adjuvant to their training. PMID:26174323

  17. Tornado Detection Based on Seismic Signal.

    NASA Astrophysics Data System (ADS)

    Tatom, Frank B.; Knupp, Kevin R.; Vitton, Stanley J.

    1995-02-01

    At the present time the only generally accepted method for detecting when a tornado is on the ground is human observation. Based on theoretical considerations combined with eyewitness testimony, there is strong reason to believe that a tornado in contact with the ground transfers a significant amount of energy into the ground. The amount of energy transferred depends upon the intensity of the tornado and the characteristics of the surface. Some portion of this energy takes the form of seismic waves, both body and surface waves. Surface waves (Rayleigh and possibly Love) represent the most likely type of seismic signal to be detected. Based on the existence of such a signal, a seismic tornado detector appears conceptually possible. The major concerns for designing such a detector are range of detection and discrimination between the tornadic signal and other types of surface waves generated by ground transportation equipment, high winds, or other nontornadic sources.

  18. Recollection- and Familiarity-Based Decisions Reflect Memory Strength

    PubMed Central

    Wiesmann, Martin; Ishai, Alumit

    2008-01-01

    We used event-related fMRI to investigate whether recollection- and familiarity-based memory judgments are modulated by the degree of visual similarity between old and new art paintings. Subjects performed a flower detection task, followed by a Remember/Know/New surprise memory test. The old paintings were randomly presented with new paintings, which were either visually similar or visually different. Consistent with our prediction, subjects were significantly faster and more accurate to reject new, visually different paintings than new, visually similar ones. The proportion of false alarms, namely remember and know responses to new paintings, was significantly reduced with decreased visual similarity. The retrieval task evoked activation in multiple visual, parietal and prefrontal regions, within which remember judgments elicited stronger activation than know judgments. New, visually different paintings evoked weaker activation than new, visually similar items in the intraparietal sulcus. Contrasting recollection with familiarity revealed activation predominantly within the precuneus, where the BOLD response elicited by recollection peaked significantly earlier than the BOLD response evoked by familiarity judgments. These findings suggest that successful memory retrieval of pictures is mediated by activation in a distributed cortical network, where memory strength is manifested by differential hemodynamic profiles. Recollection- and familiarity-based memory decisions may therefore reflect strong memories and weak memories, respectively. PMID:18958245

  19. The beneficial effects of strength exercise on hippocampal cell proliferation and apoptotic signaling is impaired by anabolic androgenic steroids.

    PubMed

    Novaes Gomes, Fabiano Guimarães; Fernandes, Jansen; Vannucci Campos, Diego; Cassilhas, Ricardo Cardoso; Viana, Gustavo Monteiro; D'Almeida, Vânia; de Moraes Rêgo, Marta Karavisch; Buainain, Pedro Ivo; Cavalheiro, Esper Abrão; Arida, Ricardo Mario

    2014-12-01

    Previous studies have shown that strength exercise improves memory and increases expression of a myriad of proteins involved on neuronal survival and synaptic plasticity in the hippocampus. Conversely, chronic exposure to supraphysiological levels of anabolic androgenic steroids (AAS) can induce psychiatric abnormalities, cognitive deficits, impair neurotransmission, alter the levels of neurotrophic factors, decrease cell proliferation and neurogenesis, and enhance neuronal cell death. In the present study, we investigated the effects of the AAS nandrolone decanoate (ND) administration during a strength exercise program on cell proliferation, apoptotic status and brain-derived neurotrophic factor (BDNF) expression in the rat hippocampus. Adult male Wistar rats were subjected to 4 weeks of progressive strength exercise in a vertical ladder apparatus with or without daily doses (5.0 mg/kg, SC) of ND. Immunohistochemistry analysis revealed that strength exercise increased significantly the number of Ki-67-positive cells (a cell proliferation marker) in dentate gyrus (DG) of hippocampus. However, this effect was abrogated when strength exercise was combined with ND. Although western blot analysis of whole hippocampus showed no significant differences in Bax and Bcl-2 protein expression among groups, the immunoreactivity of the pro-apoptotic protein Bax was significantly increased in DG, CA1 and CA3 hippocampal subfields of sedentary rats treated with ND. Moreover, the increase in the immunoreactivity of anti-apoptotic protein Bcl-2 (DG and CA3) induced by strength exercise was diminished by ND. There were no significant differences in BDNF expression among experimental groups. Therefore, the present findings suggest that the beneficial effects of strength exercise on hippocampal cell proliferation and apoptotic signaling are impaired by ND.

  20. Characterization of the respiratory and heart beat signal from an air pressure-based ballistocardiographic setup.

    PubMed

    Willemen, Tim; Van Deun, Dorien; Verhaert, Vincent; Van Huffel, Sabine; Haex, Bart; Vander Sloten, Jos

    2014-01-01

    Off-body detection of respiratory and cardiac activity presents an enormous opportunity for general health, stress and sleep quality monitoring. The presented setup detects the mechanical activity of both heart and lungs by measuring pressure difference fluctuations between two air volumes underneath the chest area of the subject. The registered signals were characterized over four different sleep postures, three different base air pressures within the air volumes and three different mattress top layer materials. Highest signal strength was detected in prone posture for both the respiratory and heart beat signal. Respiratory signal strength was the lowest in supine posture, while heart beat signal strength was lowest for right lateral. Heart beat cycle variability was highest in prone and lowest in supine posture. Increasing the base air pressure caused a reduction in signal amplitude for both the respiratory and the heart beat signal. A visco-elastic poly-urethane foam top layer had significantly higher respiration amplitude compared to high resilient poly-urethane foam and latex foam. For the heart beat signal, differences between the top layers were small. The authors conclude that, while the influence of the mattress top layer material is small, the base air pressure can be tuned for optimal mechanical transmission from heart and lungs towards the registration setup.

  1. Simulate different environments TDLAS On the analysis of the test signal strength

    NASA Astrophysics Data System (ADS)

    Li, Xin; Zhou, Tao; Jia, Xiaodong

    2014-12-01

    TDLAS system is the use of the wavelength tuning characteristics of the laser diode, for detecting the absorption spectrum of the gas absorption line. Detecting the gas space, temperature, pressure and flow rate and concentration. The use of laboratory techniques TDLAS gas detection, experimental simulation engine combustion water vapor and smoke. using an optical lens system receives the signal acquisition and signal interference test analysis. Analog water vapor and smoke in two different environments in the sample pool interference. In both experiments environmental interference gas absorption in the optical signal acquisition, signal amplitude variation analysis, and records related to the signal data. In order to study site conditions in the engine combustion process for signal acquisition provides an ideal experimental data .

  2. Subgraph-Based Filterbanks for Graph Signals

    NASA Astrophysics Data System (ADS)

    Tremblay, Nicolas; Borgnat, Pierre

    2016-08-01

    We design a critically-sampled compact-support biorthogonal transform for graph signals, via graph filterbanks. Instead of partitioning the nodes in two sets so as to remove one every two nodes in the filterbank downsampling operations, the design is based on a partition of the graph in connected subgraphs. Coarsening is achieved by defining one "supernode" for each subgraph and the edges for this coarsened graph derives from the connectivity between the subgraphs. Unlike the "one every two nodes" downsampling on bipartite graphs, this coarsening operation does not have an exact formulation in the graph Fourier domain. Instead, we rely on the local Fourier bases of each subgraph to define filtering operations. We apply successfully this method to decompose graph signals, and show promising performance on compression and denoising.

  3. Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector

    SciTech Connect

    Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Aben, R.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Affolder, A. A.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akerstedt, H.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexopoulos, T.; Alhroob, M.; Alimonti, G.; Alio, L.; Alison, J.; Alkire, S. P.; Allbrooke, B. M. M.; Allport, P. P.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Altheimer, A.; Alvarez Gonzalez, B.; Piqueras, D. Álvarez; Alviggi, M. G.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Angelidakis, S.; Angelozzi, I.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Arabidze, G.; Arai, Y.; Araque, J. P.; Arce, A. T. H.; Arduh, F. A.; Arguin, J-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Asai, S.; Asbah, N.; Ashkenazi, A.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Auerbach, B.; Augsten, K.; Aurousseau, M.; Avolio, G.; Axen, B.; Ayoub, M. K.; Azuelos, G.; Baak, M. A.; Baas, A. E.; Bacci, C.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Badescu, E.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bain, T.; Baines, J. T.; Baker, O. K.; Balek, P.; Balestri, T.; Balli, F.; Banas, E.; Banerjee, Sw.; Bannoura, A. A. E.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnes, S. L.; Barnett, B. M.; Barnett, R. M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Bassalat, A.; Basye, A.; Bates, R. L.; Batista, S. J.; Batley, J. R.; Battaglia, M.; Bauce, M.; Bauer, F.; Bawa, H. S.; Beacham, J. B.; Beattie, M. D.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, M.; Becker, S.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, J. K.; Belanger-Champagne, C.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bender, M.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Bensinger, J. R.; Bentvelsen, S.; Beresford, L.; Beretta, M.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Beringer, J.; Bernard, C.; Bernard, N. R.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertsche, C.; Bertsche, D.; Besana, M. I.; Besjes, G. J.; Bessidskaia Bylund, O.; Bessner, M.; Besson, N.; Betancourt, C.; Bethke, S.; Bevan, A. J.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Biglietti, M.; Bilbao De Mendizabal, J.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J. -B.; Blanco, J. E.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Bock, C.; Boehler, M.; Bogaerts, J. A.; Bogdanchikov, A. G.; Bohm, C.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A. S.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozic, I.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brendlinger, K.; Brennan, A. J.; Brenner, L.; Brenner, R.; Bressler, S.; Bristow, K.; Bristow, T. M.; Britton, D.; Britzger, D.; Brochu, F. M.; Brock, I.; Brock, R.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Brown, J.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Bruni, A.; Bruni, G.; Bruschi, M.; Bryngemark, L.; Buanes, T.; Buat, Q.; Buchholz, P.; Buckley, A. G.; Buda, S. I.; Budagov, I. A.; Buehrer, F.; Bugge, L.; Bugge, M. K.

    2015-07-01

    Measurements of the ZZ and WW final states in the mass range above the 2mZ and 2mW thresholds provide a unique opportunity to measure the off-shell coupling strength of the Higgs boson. This paper presents constraints on the off-shell Higgs boson event yields normalised to the Standard Model prediction (signal strength) in the ZZ→4ℓ, ZZ→2ℓ2ν and WW→eνμν final states. The result is based on pp collision data collected by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 20.3 fb-1 at a collision energy of √s=8 TeV. Using the CLs method, the observed 95 %% confidence level (CL) upper limit on the off-shell signal strength is in the range 5.1–8.6, with an expected range of 6.7–11.0. In each case the range is determined by varying the unknown gg→ZZ and gg→WW background K-factor from higher-order quantum chromodynamics corrections between half and twice the value of the known signal K-factor. Assuming the relevant Higgs boson couplings are independent of the energy scale of the Higgs boson production, a combination with the on-shell measurements yields an observed (expected) 95 % CL upper limit on ΓH/ΓSMH in the range 4.5–7.5 (6.5–11.2) using the same variations of the background K-factor. Assuming that the unknown gg→VV background K-factor is equal to the signal K-factor, this translates into an observed (expected) 95 % CL upper limit on the Higgs boson total width of 22.7 (33.0) MeV.

  4. A Mixed-Method Evaluation of a Strength-Based Bullying Prevention Program

    ERIC Educational Resources Information Center

    Rawana, Jennine S.; Norwood, Sarah Jane; Whitley, Jessica

    2011-01-01

    The goal of this study was to describe the strength-based bullying prevention program, "Strengths in Motion," and to evaluate the program utilizing a mixed-method design. Participants included students in Grades 4 to 8 from an intervention (n = 50) and a comparison (n = 53) school in Northern Ontario. Measures of bullying, strengths, and classroom…

  5. The calcium ATPase SERCA2 regulates desmoplakin dynamics and intercellular adhesive strength through modulation of PKCα signaling

    PubMed Central

    Hobbs, Ryan P.; Amargo, Evangeline V.; Somasundaram, Agila; Simpson, Cory L.; Prakriya, Murali; Denning, Mitchell F.; Green, Kathleen J.

    2011-01-01

    Darier's disease (DD) is an inherited autosomal-dominant skin disorder characterized histologically by loss of adhesion between keratinocytes. DD is typically caused by mutations in sarcoendoplasmic reticulum Ca2+-ATPase isoform 2 (SERCA2), a major regulator of intracellular Ca2+ homeostasis in the skin. However, a defined role for SERCA2 in regulating intercellular adhesion remains poorly understood. We found that diminution of SERCA2 function by pharmacological inhibition or siRNA silencing in multiple human epidermal-derived cell lines was sufficient to disrupt desmosome assembly and weaken intercellular adhesive strength. Specifically, SERCA2-deficient cells exhibited up to a 60% reduction in border translocation of desmoplakin (DP), the desmosomal cytolinker protein necessary for intermediate filament (IF) anchorage to sites of robust cell-cell adhesion. In addition, loss of SERCA2 impaired the membrane translocation of protein kinase C α (PKCα), a known regulator of DP-IF association and desmosome assembly, to the plasma membrane by up to 70%. Exogenous activation of PKCα in SERCA2-deficient cells was sufficient to rescue the defective DP localization, desmosome assembly, and intercellular adhesive strength to levels comparable to controls. Our findings indicate that SERCA2-deficiency is sufficient to impede desmosome assembly and weaken intercellular adhesive strength via a PKCα-dependent mechanism, implicating SERCA2 as a novel regulator of PKCα signaling.—Hobbs, R. P., Amargo, E. V., Somasundaram, A., Simpson, C. L., Prakriya, M., Denning, M. F., Green, K. J. The calcium ATPase SERCA2 regulates desmoplakin dynamics and intercellular adhesive strength through modulation of PKCα signaling. PMID:21156808

  6. Insulin signaling in skeletal muscle of HIV-infected patients in response to endurance and strength training.

    PubMed

    Broholm, Christa; Mathur, Neha; Hvid, Thine; Grøndahl, Thomas Sahl; Frøsig, Christian; Pedersen, Bente Klarlund; Lindegaard, Birgitte

    2013-08-01

    Human immunodeficiency virus (HIV)-infected patients with lipodystrophy have decreased insulin-stimulated glucose uptake. Both endurance and resistance training improve insulin-stimulated glucose uptake in skeletal muscle of HIV-infected patients, but the mechanisms are unknown. This study aims to identify the molecular pathways involved in the beneficial effects of training on insulin-stimulated glucose uptake in skeletal muscle of HIV-infected patients. Eighteen sedentary male HIV-infected patients underwent a 16 week supervised training intervention, either resistance or strength training. Euglycemic-hyperinsulinemic clamps with muscle biopsies were performed before and after the training interventions. Fifteen age- and body mass index (BMI)-matched HIV-negative men served as a sedentary baseline group. Phosphorylation and total protein expression of insulin signaling molecules as well as glycogen synthase (GS) activity were analyzed in skeletal muscle biopsies in relation to insulin stimulation before and after training. HIV-infected patients had reduced basal and insulin-stimulated GS activity (%fractional velocity, [FV]) as well as impaired insulin-stimulated Akt(thr308) phosphorylation. Despite improving insulin-stimulated glucose uptake, neither endurance nor strength training changed the phosphorylation status of insulin signaling proteins or affected GS activity. However; endurance training markedly increased the total Akt protein expression, and both training modalities increased hexokinase II (HKII) protein. HIV-infected patients with lipodystrophy have decreased insulin-stimulated glucose uptake in skeletal muscle and defects in insulin-stimulated phosphorylation of Akt(thr308). Endurance and strength training increase insulin-stimulated glucose uptake in these patients, and the muscular training adaptation is associated with improved capacity for phosphorylation of glucose by HKII, rather than changes in markers of insulin signaling to glucose uptake

  7. Factors affecting the bond strength of denture base and reline acrylic resins to base metal materials

    PubMed Central

    TANOUE, Naomi; MATSUDA, Yasuhiro; YANAGIDA, Hiroaki; MATSUMURA, Hideo; SAWASE, Takashi

    2013-01-01

    Objective The shear bond strengths of two hard chairside reline resin materials and an auto-polymerizing denture base resin material to cast Ti and a Co-Cr alloy treated using four conditioning methods were investigated. Material and Methods Disk specimens (diameter 10 mm and thickness 2.5 mm) were cast from pure Ti and Co-Cr alloy. The specimens were wet-ground to a final surface finish of 600 grit, air-dried, and treated with the following bonding systems: 1) air-abraded with 50-70-µm grain alumina (CON); 2) 1) + conditioned with a primer, including an acidic phosphonoacetate monomer (MHPA); 3) 1) + conditioned with a primer including a diphosphate monomer (MDP); 4) treated with a tribochemical system. Three resin materials were applied to each metal specimen. Shear bond strengths were determined before and after 10,000 thermocycles. Results The strengths decreased after thermocycling for all combinations. Among the resin materials assessed, the denture base material showed significantly (p<0.05) greater shear bond strengths than the two reline materials, except for the CON condition. After 10,000 thermocycles, the bond strengths of two reline materials decreased to less than 10 MPa for both metals. The bond strengths of the denture base material with MDP were sufficient: 34.56 MPa for cast Ti and 38.30 for Co-Cr alloy. Conclusion Bonding of reline resin materials to metals assessed was clinically insufficient, regardless of metal type, surface treatment, and resin composition. For the relining of metal denture frameworks, a denture base material should be used. PMID:24037070

  8. Equations for estimating the strength of TV signals scattered by wind turbines

    NASA Astrophysics Data System (ADS)

    Spera, David A.; Sengupta, Dipak L.

    1994-05-01

    During the late 1970's and early 1980's, concerns about the potential interference of wind turbine generators with electromagnetic communication signals led to a series of research studies, both in the laboratory and in the field, conducted by the staff of the University of Michigan Radiation Laboratory. These studies were sponsored by organizations such as the U.S. Department of Energy, the Solar Energy Research Institute, and private developers of wind power stations. Research objectives were to identify the mechanisms by which wind turbines might adversely affect communication signals, estimate the severity of these effects for different types of signals (e.g. television, radio, microwave, and navigation), and formulate mathematical models with which to predict the sizes of potential interference zones around wind turbines and wind power plants. This work formed the basis for preliminary standards on assessing electromagnetic interference (EMI) by wind turbines. With the current renewal of interest in wind energy projects, it is appropriate that the many experimental and analytical aspects of this pioneering work be reviewed and correlated. The purpose of this study is to combine test data and theory from previously published and unpublished research reports into a unified and consistent set of equations which are useful for estimating potential levels of television interference from wind turbines. To be comprehensive, these equations will include both horizontal-axis and vertical-axis wind turbines (HAWT's and VAWT's), blade configuration parameters (e.g. number, size, material, twist, and coning), signal frequency and power, and directional characteristics of the receiving antenna. The approach that is followed in this report is as follows. First, some basic equations that describe electromagnetic signals with interference are presented without detailed derivations, since the latter are available in the references. Minor changes in terminology are made for

  9. Equations for Estimating the Strength of TV Signals Scattered by Wind Turbines

    NASA Technical Reports Server (NTRS)

    Spera, David A.; Sengupta, Dipak L.

    1994-01-01

    During the late 1970's and early 1980's, concerns about the potential interference of wind turbine generators with electromagnetic communication signals led to a series of research studies, both in the laboratory and in the field, conducted by the staff of the University of Michigan Radiation Laboratory. These studies were sponsored by organizations such as the U.S. Department of Energy, the Solar Energy Research Institute, and private developers of wind power stations. Research objectives were to identify the mechanisms by which wind turbines might adversely affect communication signals, estimate the severity of these effects for different types of signals (e.g. television, radio, microwave, and navigation), and formulate mathematical models with which to predict the sizes of potential interference zones around wind turbines and wind power plants. This work formed the basis for preliminary standards on assessing electromagnetic interference (EMI) by wind turbines. With the current renewal of interest in wind energy projects, it is appropriate that the many experimental and analytical aspects of this pioneering work be reviewed and correlated. The purpose of this study is to combine test data and theory from previously published and unpublished research reports into a unified and consistent set of equations which are useful for estimating potential levels of television interference from wind turbines. To be comprehensive, these equations will include both horizontal-axis and vertical-axis wind turbines (HAWT's and VAWT's), blade configuration parameters (e.g. number, size, material, twist, and coning), signal frequency and power, and directional characteristics of the receiving antenna. The approach that is followed in this report is as follows. First, some basic equations that describe electromagnetic signals with interference are presented without detailed derivations, since the latter are available in the references. Minor changes in terminology are made for

  10. Tyrosine-based signal mediates LRP6 receptor endocytosis and desensitization of Wnt/β-catenin pathway signaling.

    PubMed

    Liu, Chia-Chen; Kanekiyo, Takahisa; Roth, Barbara; Bu, Guojun

    2014-10-01

    Wnt/β-catenin signaling orchestrates a number of critical events including cell growth, differentiation, and cell survival during development. Misregulation of this pathway leads to various human diseases, specifically cancers. Endocytosis and phosphorylation of the LDL receptor-related protein 6 (LRP6), an essential co-receptor for Wnt/β-catenin signaling, play a vital role in mediating Wnt/β-catenin signal transduction. However, its regulatory mechanism is not fully understood. In this study, we define the mechanisms by which LRP6 endocytic trafficking regulates Wnt/β-catenin signaling activation. We show that LRP6 mutant with defective tyrosine-based signal in its cytoplasmic tail has an increased cell surface distribution and decreased endocytosis rate. These changes in LRP6 endocytosis coincide with an increased distribution to caveolae, increased phosphorylation, and enhanced Wnt/β-catenin signaling. We further demonstrate that treatment of Wnt3a ligands or blocking the clathrin-mediated endocytosis of LRP6 leads to a redistribution of wild-type receptor to lipid rafts. The LRP6 tyrosine mutant also exhibited an increase in signaling activation in response to Wnt3a stimulation when compared with wild-type LRP6, and this activation is suppressed when caveolae-mediated endocytosis is blocked. Our results reveal molecular mechanisms by which LRP6 endocytosis routes regulate its phosphorylation and the strength of Wnt/β-catenin signaling, and have implications on how this pathway can be modulated in human diseases.

  11. General strategy for biodetection in high ionic strength solutions using transistor-based nanoelectronic sensors.

    PubMed

    Gao, Ning; Zhou, Wei; Jiang, Xiaocheng; Hong, Guosong; Fu, Tian-Ming; Lieber, Charles M

    2015-03-11

    Transistor-based nanoelectronic sensors are capable of label-free real-time chemical and biological detection with high sensitivity and spatial resolution, although the short Debye screening length in high ionic strength solutions has made difficult applications relevant to physiological conditions. Here, we describe a new and general strategy to overcome this challenge for field-effect transistor (FET) sensors that involves incorporating a porous and biomolecule permeable polymer layer on the FET sensor. This polymer layer increases the effective screening length in the region immediately adjacent to the device surface and thereby enables detection of biomolecules in high ionic strength solutions in real-time. Studies of silicon nanowire field-effect transistors with additional polyethylene glycol (PEG) modification show that prostate specific antigen (PSA) can be readily detected in solutions with phosphate buffer (PB) concentrations as high as 150 mM, while similar devices without PEG modification only exhibit detectable signals for concentrations ≤10 mM. Concentration-dependent measurements exhibited real-time detection of PSA with a sensitivity of at least 10 nM in 100 mM PB with linear response up to the highest (1000 nM) PSA concentrations tested. The current work represents an important step toward general application of transistor-based nanoelectronic detectors for biochemical sensing in physiological environments and is expected to open up exciting opportunities for in vitro and in vivo biological sensing relevant to basic biology research through medicine.

  12. Osteogenic signaling on silk-based matrices.

    PubMed

    Midha, Swati; Murab, Sumit; Ghosh, Sourabh

    2016-08-01

    Bone tissue engineering has mainly focused on generating 3D grafts to repair bone defects. However, the underlying signaling mechanisms responsible for development of such 3D bone equivalents have largely been ignored. Here we describe the crucial aspects of embryonic osteogenesis and bone development including cell sources and general signaling cascades that guide mesenchymal progenitors towards osteogenic lineage. Drawing from the knowledge of developmental biology, we then review how silk biomaterial can regulate osteogenic signaling by focusing on the expression of cell surface markers, functional genomic information (mRNA) of stem cells cultured on silk matrices. In an attempt to recapitulate exact in vivo microenvironment of osteogenesis, role of scaffold architecture and material chemistry in regulating cellular differentiation is elaborated. The generated knowledge will not only improve our understanding of cell-material interactions but reveal newer strategies beyond a conventional tissue engineering paradigm and open new prospects for developing silk-based therapies against clinically relevant bone disorders. PMID:27163625

  13. Taking a Strengths-Based Focus Improves School Climate

    ERIC Educational Resources Information Center

    Tschannen-Moran, Megan; Tschannen-Moran, Bob

    2011-01-01

    The purpose of this study was to learn whether focusing on strengths through appreciative inquiry would be related to measurable changes in school climate and trust within a small urban school district. The district studied was a beleaguered, underperforming school district in the Midwest Rust Belt. Through an appreciative inquiry initiative, the…

  14. Sleep stage classification based on respiratory signal.

    PubMed

    Tataraidze, Alexander; Anishchenko, Lesya; Korostovtseva, Lyudmila; Kooij, Bert Jan; Bochkarev, Mikhail; Sviryaev, Yurii

    2015-01-01

    One of the research tasks, which should be solved to develop a sleep monitor, is sleep stages classification. This paper presents an algorithm for wakefulness, rapid eye movement sleep (REM) and non-REM sleep detection based on a set of 33 features, extracted from respiratory inductive plethysmography signal, and bagging classifier. Furthermore, a few heuristics based on knowledge about normal sleep structure are suggested. We used the data from 29 subjects without sleep-related breathing disorders who underwent a PSG study at a sleep laboratory. Subjects were directed to the PSG study due to suspected sleep disorders. A leave-one-subject-out cross-validation procedure was used for testing the classification performance. The accuracy of 77.85 ± 6.63 and Cohen's kappa of 0.59 ± 0.11 were achieved for the classifier. Using heuristics we increased the accuracy to 80.38 ± 8.32 and the kappa to 0.65 ± 0.13. We conclude that heuristics may improve the automated sleep structure detection based on the analysis of indirect information such as respiration signal and are useful for the development of home sleep monitoring system. PMID:26736273

  15. Biologically-based signal processing system applied to noise removal for signal extraction

    DOEpatents

    Fu, Chi Yung; Petrich, Loren I.

    2004-07-13

    The method and system described herein use a biologically-based signal processing system for noise removal for signal extraction. A wavelet transform may be used in conjunction with a neural network to imitate a biological system. The neural network may be trained using ideal data derived from physical principles or noiseless signals to determine to remove noise from the signal.

  16. Traits-based approaches in bioassessment and ecological risk assessment: strengths, weaknesses, opportunities and threats.

    PubMed

    Van den Brink, Paul J; Alexander, Alexa C; Desrosiers, Mélanie; Goedkoop, Willem; Goethals, Peter L M; Liess, Matthias; Dyer, Scott D

    2011-04-01

    We discuss the application of traits-based bioassessment approaches in retrospective bioassessment as well as in prospective ecological risk assessments in regulatory frameworks. Both approaches address the interaction between species and stressors and their consequences at different levels of biological organization, but the fact that a specific species may be less abundant in a potentially impacted site compared with a reference site is, regrettably, insufficient to provide diagnostic information. Species traits may, however, overcome the problems associated with taxonomy-based bioassessment. Trait-based approaches could provide signals regarding what environmental factors may be responsible for the impairment and, thereby, provide causal insight into the interaction between species and stressors. For development of traits-based (TBA), traits should correspond to specific types of stressors or suites of stressors. In this paper, a strengths, weaknesses, opportunities, and threats (SWOT) analysis of TBA in both applications was used to identify challenges and potentials. This paper is part of a series describing the output of the TERA (Traits-based ecological risk assessment: Realising the potential of ecoinformatics approaches in ecotoxicology) Workshop held between 7 and 11 September, 2009, in Burlington, Ontario, Canada. The recognized strengths were that traits are transferrable across geographies, add mechanistic and diagnostic knowledge, require no new sampling methodology, have an old tradition, and can supplement taxonomic analysis. Weaknesses include autocorrelation, redundancy, and inability to protect biodiversity directly. Automated image analysis, combined with genetic and biotechnology tools and improved data analysis to solve autocorrelation problems were identified as opportunities, whereas low availability of trait data, their transferability, their quantitative interpretation, the risk of developing nonrelevant traits, low quality of historic

  17. Using Strengths-Based Approaches in Early Years Practice and Research

    ERIC Educational Resources Information Center

    Fenton, Angela; Walsh, Kerryann; Wong, Sandie; Cumming, Tamara

    2015-01-01

    Strengths-based approaches draw upon frameworks and perspectives from social work and psychology but have not necessarily been consistently defined or well articulated across disciplines. Internationally, there are increasing calls for professionals in early years settings to work in strengths-based ways to support the access and participation of…

  18. Moving from Pathology to Possibility: Integrating Strengths-Based Interventions in Child Welfare Provision

    ERIC Educational Resources Information Center

    Sabalauskas, Kara L.; Ortolani, Charles L.; McCall, Matthew J.

    2014-01-01

    Child welfare providers are increasingly required to demonstrate that strengths-based, evidence-informed practices are central to their intervention methodology. This case study describes how a large child welfare agency instituted cognitive behavioural therapy (CBT) as the core component of a strength-based practice model with the goal of…

  19. The Use of Mapping in Child Welfare Investigations: A Strength-Based Hybrid Intervention

    ERIC Educational Resources Information Center

    Lwin, Kristen; Versanov, Avi; Cheung, Connie; Goodman, Deborah; Andrews, Nancy

    2014-01-01

    To enhance strengths-based service, a large urban child welfare agency in Ontario, Canada implemented part of the Signs of Safety (SOS) model in 2010. SOS was created to engage families involved with the child welfare system, and is rooted in the beliefs of collaboration, strengths-based practice, and safety. The hybrid of the full SOS model…

  20. Fatigue Strength Prediction of Drilling Materials Based on the Maximum Non-metallic Inclusion Size

    NASA Astrophysics Data System (ADS)

    Zeng, Dezhi; Tian, Gang; Liu, Fei; Shi, Taihe; Zhang, Zhi; Hu, Junying; Liu, Wanying; Ouyang, Zhiying

    2015-12-01

    In this paper, the statistics of the size distribution of non-metallic inclusions in five drilling materials were performed. Based on the maximum non-metallic inclusion size, the fatigue strength of the drilling material was predicted. The sizes of non-metallic inclusions in drilling materials were observed to follow the inclusion size distribution rule. Then the maximum inclusion size in the fatigue specimens was deduced. According to the prediction equation of the maximum inclusion size and fatigue strength proposed by Murakami, fatigue strength of drilling materials was obtained. Moreover, fatigue strength was also measured through rotating bending tests. The predicted fatigue strength was significantly lower than the measured one. Therefore, according to the comparison results, the coefficients in the prediction equation were revised. The revised equation allowed the satisfactory prediction results of fatigue strength of drilling materials at the fatigue life of 107 rotations and could be used in the fast prediction of fatigue strength of drilling materials.

  1. Enhanced long-term strength and durability of shotcrete with high-strength C{sub 12}A{sub 7} mineral-based accelerator

    SciTech Connect

    Won, Jong-Pil Hwang, Un-Jong; Lee, Su-Jin

    2015-10-15

    This study evaluated the performance of shotcrete using high strength C{sub 12}A{sub 7} mineral-based accelerator that has been developed to improve the durability and long-term strength. Rebound, compressive strength and flexural strength were tested in the field. Test result showed that existing C{sub 12}A{sub 7} mineral-based accelerator exhibits better early strength than the high-strength C{sub 12}A{sub 7} mineral-based accelerator until the early age, but high-strength C{sub 12}A{sub 7} mineral-based accelerator shows about 29% higher at the long-term age of 28 days. Microstructural analysis such as scanning electron microscope (SEM), X-ray diffraction (XRD) and nitrogen adsorption method was evaluated to analyze long-term strength development mechanism of high strength C{sub 12}A{sub 7} mineral-based accelerator. As analysis result, it had more dense structure due to the reaction product by adding material that used to enhanced strength. It had better resistance performance in chloride ion penetration, freezing–thawing and carbonation than shotcrete that used existing C{sub 12}A{sub 7} mineral-based accelerator.

  2. Thermally enhanced signal strength and SNR improvement of photoacoustic radar module

    PubMed Central

    Wang, Wei; Mandelis, Andreas

    2014-01-01

    A thermally enhanced method for improving photoacoustic imaging depth and signal-to-noise (SNR) ratio is presented in this paper. Experimental results showed that the maximum imaging depth increased by 20% through raising the temperature of absorbing biotissues (ex-vivo beef muscle) uniformly from 37 to 43°C, and the SNR was increased by 8%. The parameters making up the Gruneisen constant were investigated experimentally and theoretically. The studies showed that the Gruneisen constant of biotissues increases with temperature, and the results were found to be consistent with the photoacousitc radar theory. PMID:25136501

  3. Spatial design and strength of spatial signal: Effects on covariance estimation

    USGS Publications Warehouse

    Irvine, Kathryn M.; Gitelman, Alix I.; Hoeting, Jennifer A.

    2007-01-01

    In a spatial regression context, scientists are often interested in a physical interpretation of components of the parametric covariance function. For example, spatial covariance parameter estimates in ecological settings have been interpreted to describe spatial heterogeneity or “patchiness” in a landscape that cannot be explained by measured covariates. In this article, we investigate the influence of the strength of spatial dependence on maximum likelihood (ML) and restricted maximum likelihood (REML) estimates of covariance parameters in an exponential-with-nugget model, and we also examine these influences under different sampling designs—specifically, lattice designs and more realistic random and cluster designs—at differing intensities of sampling (n=144 and 361). We find that neither ML nor REML estimates perform well when the range parameter and/or the nugget-to-sill ratio is large—ML tends to underestimate the autocorrelation function and REML produces highly variable estimates of the autocorrelation function. The best estimates of both the covariance parameters and the autocorrelation function come under the cluster sampling design and large sample sizes. As a motivating example, we consider a spatial model for stream sulfate concentration.

  4. The intersection of software and strengths: Using internet technology and case management software to assist Strength-Based Practice.

    PubMed

    Clark, Michael D; Brien, Dale W

    2016-01-01

    The focus of this investigation is the helping professionals working within American Indian and Alaska Native (AI/AN) communities. This article looks at how innovative technology-in the form of automated case management software and Internet connectivity-can assist effective implementation of Strength-based Practice and agency services within tribal courts and the many other helping agencies that serve AI/AN populations. We seek to expand practice knowledge by reviewing the benefits that this software and Internet connectivity can offer to agency operations and exploring how they can assist case management services. PMID:27383086

  5. Restoration of muscle strength in dystrophic muscle by angiotensin-1-7 through inhibition of TGF-β signalling.

    PubMed

    Acuña, María José; Pessina, Patrizia; Olguin, Hugo; Cabrera, Daniel; Vio, Carlos P; Bader, Michael; Muñoz-Canoves, Pura; Santos, Robson A; Cabello-Verrugio, Claudio; Brandan, Enrique

    2014-03-01

    Duchenne muscular dystrophy (DMD) is the most common inherited neuromuscular disease, and is characterized by the lack of dystrophin, muscle wasting, increased transforming growth factor (TGF)-β Smad-dependent signalling and fibrosis. Acting via the Mas receptor, angiotensin-1-7 [Ang-(1-7)], is part of the renin-angiotensin system, with the opposite effect to that of angiotensin II. We hypothesized that the Ang-(1-7)/Mas receptor axis might protect chronically damaged tissues as in skeletal muscle of the DMD mouse model mdx. Infusion or oral administration of Ang-(1-7) in mdx mice normalized skeletal muscle architecture, decreased local fibrosis and improved muscle function in vitro and in vivo. These positive effects were mediated by the inhibition of TGF-β Smad signalling, which in turn led to reduction of the pro-fibrotic microRNA miR-21 concomitant with a reduction in the number of TCF4 expressing fibroblasts. Mdx mice infused with Mas antagonist (A-779) and mdx deficient for the Mas receptor showed highly deteriorated muscular architecture, increased fibrosis and TGF-β signalling with diminished muscle strength. These results suggest that this novel compound Ang-(1-7) might be used to improve quality of life and delay death in individuals with DMD and this drug should be investigated in further pre-clinical trials.

  6. Nonlinear genetic-based simulation of soil shear strength parameters

    NASA Astrophysics Data System (ADS)

    Mousavi, Seyyed Mohammad; Alavi, Amir Hossein; Gandomi, Amir Hossein; Mollahasani, Ali

    2011-12-01

    New nonlinear solutions were developed to estimate the soil shear strength parameters utilizing linear genetic programming (LGP). The soil cohesion intercept ( c) and angle of shearing resistance ( ϕ) were formulated in terms of the basic soil physical properties. The best models were selected after developing and controlling several models with different combinations of influencing parameters. Comprehensive experimental database used for developing the models was established upon a series of unconsolidated, undrained, and unsaturated triaxial tests conducted in this study. Further, sensitivity and parametric analyses were carried out. c and ϕ were found to be mostly influenced by the soil unit weight and liquid limit. In order to benchmark the proposed models, a multiple least squares regression (MLSR) analysis was performed. The validity of the models was proved on portions of laboratory results that were not included in the modelling process. The developed models are able to effectively learn the complex relationship between the soil strength parameters and their contributing factors. The LGP models provide a significantly better prediction performance than the regression models.

  7. Attitude Detection Method of Nano Satellite HIT-SAT by Fluctuation of Received Signal Strength

    NASA Astrophysics Data System (ADS)

    Sato, Tatsuhiro; Mitsuhashi, Ryuichi; Satori, Shin; Sasaki, Issei

    In recent years, many universities have already launched small satellite on-orbit. Attitude information is important for satellite operation. However, many nano-satellite communication systems used amateur radio by narrow bandwidth frequency segment. Therefore, down-link of attitude information is expected to require substantial time. In this paper, we propose establishment of the attitude estimation method by means of the received radio power. And, satellite attitude information being estimated from the fluctuation of the received power. Then, comparison of satellite data obtained from on-board sensors with ground experiment. One major problem in this approach is the effect of Earth's ionosphere. As the radio signal passes through the ionosphere, the polarization angle is rotated by the Faraday Effect. The detection of attitude by the radiation pattern has been assumed that inaccurate. However, we are get data the spin satellite of liner polarization antenna. As a result, we can estimate 0.12rad/s accuracy of angular velocity measurement. This method can be applied to the attitude detection of many small satellites.

  8. Signal strength and climate calibration of a European tree-ring isotope network

    NASA Astrophysics Data System (ADS)

    Treydte, K.; Frank, D.; Esper, J.; Andreu, L.; Bednarz, Z.; Berninger, F.; Boettger, T.; D'Alessandro, C. M.; Etien, N.; Filot, M.; Grabner, M.; Guillemin, M. T.; Gutierrez, E.; Haupt, M.; Helle, G.; Hilasvuori, E.; Jungner, H.; Kalela-Brundin, M.; Krapiec, M.; Leuenberger, M.; Loader, N. J.; Masson-Delmotte, V.; Pazdur, A.; Pawelczyk, S.; Pierre, M.; Planells, O.; Pukiene, R.; Reynolds-Henne, C. E.; Rinne, K. T.; Saracino, A.; Saurer, M.; Sonninen, E.; Stievenard, M.; Switsur, V. R.; Szczepanek, M.; Szychowska-Krapiec, E.; Todaro, L.; Waterhouse, J. S.; Weigl, M.; Schleser, G. H.

    2007-12-01

    We present the first European network of tree ring δ 13C and δ 18O, containing 23 sites from Finland to Morocco. Common climate signals are found over broad climatic-ecological ranges. In temperate regions we find positive correlations with summer maximum temperatures and negative correlations with summer precipitation and Palmer Drought Severity Indices (PDSI) with no obvious species-specific differences. Regional δ 13C and δ 18O chronologies share high common variance in year-to-year variations. Long-term variations, however, exhibit differences that may reflect spatial variability in environmental forcings, age trends and/or plant physiological responses to increasing atmospheric CO2 concentration. Rotated principal component analysis (RPCA) and climate field correlations enable the identification of four sub-regions in the δ 18O network - northern and eastern Central Europe, Scandinavia and the western Mediterranean. Regional patterns in the δ 13C network are less clear and are timescale dependent. Our results indicate that future reconstruction efforts should concentrate on δ 18O data in the identified European regions.

  9. Anisotropy of high temperature strength in precipitation-hardened nickel-base superalloy single crystals

    NASA Technical Reports Server (NTRS)

    Nakagawa, Y. G.; Terashima, H.; Yoshizawa, H.; Ohta, Y.; Murakami, K.

    1986-01-01

    The anisotropy of high temperature strength of nickel-base superalloy, Alloy 454, in service for advanced jet engine turbine blades and vanes, was investigated. Crystallographic orientation dependence of tensile yield strength, creep and creep rupture strength was found to be marked at about 760C. In comparison with other single crystal data, a larger allowance in high strength off-axial orientation from the 001 axis, and relatively poor strength at near the -111 axis were noted. From transmission electron microscopy the anisotropic characteristics of this alloy were explained in terms of available slip systems and stacking geometries of gamma-prime precipitate cuboids which are well hardened by a large tantalum content. 100 cube slip was considered to be primarily responsible for the poor strength of the -111 axis orientation replacing the conventional 111 plane slip systems.

  10. Single cell tuning of Myc expression by antigen receptor signal strength and interleukin-2 in T lymphocytes.

    PubMed

    Preston, Gavin C; Sinclair, Linda V; Kaskar, Aneesa; Hukelmann, Jens L; Navarro, Maria N; Ferrero, Isabel; MacDonald, H Robson; Cowling, Victoria H; Cantrell, Doreen A

    2015-08-01

    Myc controls the metabolic reprogramming that supports effector T cell differentiation. The expression of Myc is regulated by the T cell antigen receptor (TCR) and pro-inflammatory cytokines such as interleukin-2 (IL-2). We now show that the TCR is a digital switch for Myc mRNA and protein expression that allows the strength of the antigen stimulus to determine the frequency of T cells that express Myc. IL-2 signalling strength also directs Myc expression but in an analogue process that fine-tunes Myc quantity in individual cells via post-transcriptional control of Myc protein. Fine-tuning Myc matters and is possible as Myc protein has a very short half-life in T cells due to its constant phosphorylation by glycogen synthase kinase 3 (GSK3) and subsequent proteasomal degradation. We show that Myc only accumulates in T cells exhibiting high levels of amino acid uptake allowing T cells to match Myc expression to biosynthetic demands. The combination of digital and analogue processes allows tight control of Myc expression at the population and single cell level during immune responses. PMID:26136212

  11. Strengths-Based Assessment of Middle School Climate: A Case Demonstration

    ERIC Educational Resources Information Center

    Zeman, Laura Dreuth

    2008-01-01

    Comprehensive school reform requires all schools to conduct systematic, schoolwide evaluations of climate and safety. This article discusses a strengths-based school climate assessment model that identifies positive interactions and reinforcement of existing strengths to build a safety plan. Researchers conducted a qualitative cross-sectional…

  12. The Strength-Based Model for Counseling At-Risk Youths

    ERIC Educational Resources Information Center

    Sapp, Marty

    2006-01-01

    In her strength-based model to train counseling psychologists, Smith (2006 [this issue]) criticizes deficit models of counseling. Rather than focusing on at-risk adolescents' victim status, she argues that counseling psychologists should concentrate on identifying at-risk youths' cultural and individual strengths. One can infer from her new…

  13. Quaternion-Based Signal Analysis for Motor Imagery Classification from Electroencephalographic Signals

    PubMed Central

    Batres-Mendoza, Patricia; Montoro-Sanjose, Carlos R.; Guerra-Hernandez, Erick I.; Almanza-Ojeda, Dora L.; Rostro-Gonzalez, Horacio; Romero-Troncoso, Rene J.; Ibarra-Manzano, Mario A.

    2016-01-01

    Quaternions can be used as an alternative to model the fundamental patterns of electroencephalographic (EEG) signals in the time domain. Thus, this article presents a new quaternion-based technique known as quaternion-based signal analysis (QSA) to represent EEG signals obtained using a brain-computer interface (BCI) device to detect and interpret cognitive activity. This quaternion-based signal analysis technique can extract features to represent brain activity related to motor imagery accurately in various mental states. Experimental tests in which users where shown visual graphical cues related to left and right movements were used to collect BCI-recorded signals. These signals were then classified using decision trees (DT), support vector machine (SVM) and k-nearest neighbor (KNN) techniques. The quantitative analysis of the classifiers demonstrates that this technique can be used as an alternative in the EEG-signal modeling phase to identify mental states. PMID:26959029

  14. Quaternion-Based Signal Analysis for Motor Imagery Classification from Electroencephalographic Signals.

    PubMed

    Batres-Mendoza, Patricia; Montoro-Sanjose, Carlos R; Guerra-Hernandez, Erick I; Almanza-Ojeda, Dora L; Rostro-Gonzalez, Horacio; Romero-Troncoso, Rene J; Ibarra-Manzano, Mario A

    2016-01-01

    Quaternions can be used as an alternative to model the fundamental patterns of electroencephalographic (EEG) signals in the time domain. Thus, this article presents a new quaternion-based technique known as quaternion-based signal analysis (QSA) to represent EEG signals obtained using a brain-computer interface (BCI) device to detect and interpret cognitive activity. This quaternion-based signal analysis technique can extract features to represent brain activity related to motor imagery accurately in various mental states. Experimental tests in which users where shown visual graphical cues related to left and right movements were used to collect BCI-recorded signals. These signals were then classified using decision trees (DT), support vector machine (SVM) and k-nearest neighbor (KNN) techniques. The quantitative analysis of the classifiers demonstrates that this technique can be used as an alternative in the EEG-signal modeling phase to identify mental states. PMID:26959029

  15. Quaternion-Based Signal Analysis for Motor Imagery Classification from Electroencephalographic Signals.

    PubMed

    Batres-Mendoza, Patricia; Montoro-Sanjose, Carlos R; Guerra-Hernandez, Erick I; Almanza-Ojeda, Dora L; Rostro-Gonzalez, Horacio; Romero-Troncoso, Rene J; Ibarra-Manzano, Mario A

    2016-01-01

    Quaternions can be used as an alternative to model the fundamental patterns of electroencephalographic (EEG) signals in the time domain. Thus, this article presents a new quaternion-based technique known as quaternion-based signal analysis (QSA) to represent EEG signals obtained using a brain-computer interface (BCI) device to detect and interpret cognitive activity. This quaternion-based signal analysis technique can extract features to represent brain activity related to motor imagery accurately in various mental states. Experimental tests in which users where shown visual graphical cues related to left and right movements were used to collect BCI-recorded signals. These signals were then classified using decision trees (DT), support vector machine (SVM) and k-nearest neighbor (KNN) techniques. The quantitative analysis of the classifiers demonstrates that this technique can be used as an alternative in the EEG-signal modeling phase to identify mental states.

  16. A comb filter based signal processing method to effectively reduce motion artifacts from photoplethysmographic signals.

    PubMed

    Peng, Fulai; Liu, Hongyun; Wang, Weidong

    2015-10-01

    A photoplethysmographic (PPG) signal can provide very useful information about a subject's cardiovascular status. Motion artifacts (MAs), which usually deteriorate the waveform of a PPG signal, severely obstruct its applications in the clinical diagnosis and healthcare area. To reduce the MAs from a PPG signal, in the present study we present a comb filter based signal processing method. Firstly, wavelet de-noising was implemented to preliminarily suppress a part of the MAs. Then, the PPG signal in the time domain was transformed into the frequency domain by a fast Fourier transform (FFT). Thirdly, the PPG signal period was estimated from the frequency domain by tracking the fundamental frequency peak of the PPG signal. Lastly, the MAs were removed by the comb filter which was designed based on the obtained PPG signal period. Experiments with synthetic and real-world datasets were implemented to validate the performance of the method. Results show that the proposed method can effectively restore the PPG signals from the MA corrupted signals. Also, the accuracy of blood oxygen saturation (SpO2), calculated from red and infrared PPG signals, was significantly improved after the MA reduction by the proposed method. Our study demonstrates that the comb filter can effectively reduce the MAs from a PPG signal provided that the PPG signal period is obtained. PMID:26334000

  17. A comb filter based signal processing method to effectively reduce motion artifacts from photoplethysmographic signals.

    PubMed

    Peng, Fulai; Liu, Hongyun; Wang, Weidong

    2015-10-01

    A photoplethysmographic (PPG) signal can provide very useful information about a subject's cardiovascular status. Motion artifacts (MAs), which usually deteriorate the waveform of a PPG signal, severely obstruct its applications in the clinical diagnosis and healthcare area. To reduce the MAs from a PPG signal, in the present study we present a comb filter based signal processing method. Firstly, wavelet de-noising was implemented to preliminarily suppress a part of the MAs. Then, the PPG signal in the time domain was transformed into the frequency domain by a fast Fourier transform (FFT). Thirdly, the PPG signal period was estimated from the frequency domain by tracking the fundamental frequency peak of the PPG signal. Lastly, the MAs were removed by the comb filter which was designed based on the obtained PPG signal period. Experiments with synthetic and real-world datasets were implemented to validate the performance of the method. Results show that the proposed method can effectively restore the PPG signals from the MA corrupted signals. Also, the accuracy of blood oxygen saturation (SpO2), calculated from red and infrared PPG signals, was significantly improved after the MA reduction by the proposed method. Our study demonstrates that the comb filter can effectively reduce the MAs from a PPG signal provided that the PPG signal period is obtained.

  18. Bond strength: a comparison between chemical coated and mechanical interlock bases of ceramic and metal brackets.

    PubMed

    Wang, W N; Meng, C L; Tarng, T H

    1997-04-01

    Two types of chemically coated bases, two types of mechanical interlock base polycrystalline ceramic brackets, as well as one type of mechanical interlock base metal bracket were selected for bonding with Concise orthodontic resin on 60 extracted premolars. Bond strength was measured with an Instron testing machine and the debonded interface and enamel detachment were examined with scanning electron microscope and energy dispersive x-ray spectrometer. The results showed the greater bond strength with a chemically coated base of ceramic brackets had a greater debonded interface between enamel and resin, and the weaker bond strength of mechanical interlock base of ceramic and metal brackets had a greater debonded interfaces between bracket and resin. There was no significant statistical difference in bond strengths with mechanically interlock bases between ceramic and metal brackets. The enamel detachment was found on only the stronger bond strength in which there was a chemically coated base on the ceramic bracket. Ceramic bracket fractures were not found during debonding in this specially designed specimen with 1 mm/min speed of crosshead. The mechanical interlock base of the ceramic bracket combines the strength, durability and retention of a metal bracket along with an aesthetic advantage and no enamel detachment after debonding. PMID:9109582

  19. Inferring the spatial variation of the wedge strength based on a modified critical taper model

    NASA Astrophysics Data System (ADS)

    Yang, C.; Liu, H.; Hsieh, Y.; Dong, J.

    2013-12-01

    Critical taper wedge theory has been widely applied to evaluate the strength of the detachment fault and the wedge by measuring taper angle. Traditional taper model, which incorporated constant cohesion and friction angle, fails to explain the lateral variation of the taper angle. A modified critical taper model adopting nonlinear Hoek-Brown failure criterion is proposed accordingly. The fold-and-thrust belt of central Taiwan was studied. Based on the field works and laboratory tests, the geological strength index (GSI) and the uniaxial compressive strength were obtained and the wedge strength can be estimated accordingly. The GSI values from investigation are decreased from the west to the east along the cross section due to the wedge strength heterogeneity. The uniaxial compressive strength of intact rock varies from the age of formation and lithology. The estimated wedge strength exhibits a strong spatial variation. The strength of the detachment fault was derived from rotary shear tests using fault gouge materials under different velocities and normal stresses. General speaking, the steady-state friction coefficient are about 0.29-0.46 when the shear velocity less than 0.1 m/s. The friction coefficient is not sensitive to the normal stress. Consequently, the lateral variation of the taper angle, which calculated by modified critical taper model, is mainly dominated by the wedge strength heterogeneity and the thickening of the wedge from the west to the east.

  20. Bond Strength of Resin Cements to Noble and Base Metal Alloys with Different Surface Treatments

    PubMed Central

    Raeisosadat, Farkhondeh; Ghavam, Maryam; Hasani Tabatabaei, Masoomeh; Arami, Sakineh; Sedaghati, Maedeh

    2014-01-01

    Objectives: The bond strength of resin cements to metal alloys depends on the type of the metal, conditioning methods and the adhesive resins used. The purpose of this study was to evaluate the bond strength of resin cements to base and noble metal alloys after sand blasting or application of silano-pen. Materials and Method: Cylinders of light cured Z 250 composite were cemented to “Degubond 4” (Au Pd) and “Verabond” (Ni Cr) alloys by either RelyX Unicem or Panavia F2, after sandblasting or treating the alloys with Silano-Pen. The shear bond strengths were evaluated. Data were analyzed by three-way ANOVA and t tests at a significance level of P<0.05. Results: When the alloys were treated by Silano-Pen, RelyX Unicem showed a higher bond strength for Degubond 4 (P=0.021) and Verabond (P< 0.001). No significant difference was observed in the bond strength of Panavia F2 to the alloys after either of surface treatments, Degubond 4 (P=0.291) and Verabond (P=0.899). Panavia F2 showed a higher bond strength to sandblasted Verabond compared to RelyX Unicem (P=0.003). The bond strength of RelyX Unicem was significantly higher to Silano-Pen treated Verabond (P=0.011). The bond strength of the cements to sandblasted Degubond 4 showed no significant difference (P=0.59). RelyX Unicem had a higher bond strength to Silano-Pen treated Degubond 4 (P=0.035). Conclusion: The bond strength of resin cements to Verabond alloy was significantly higher than Degubond 4. RelyX Unicem had a higher bond strength to Silano-Pen treated alloys. Surface treatments of the alloys did not affect the bond strength of Panavia F2. PMID:25628687

  1. Characterization of Tack Strength Based on Cavity-Growth Criterion.

    PubMed

    Takahashi, Kosuke; Yamagata, Yuichiro; Inaba, Kazuaki; Kishimoto, Kikuo; Tomioka, Shiori; Sugizaki, Toshio

    2016-04-12

    The adhesive force generated by a small short-term pressure, called tack, is measured by a probe tack test on pressure-sensitive adhesives (PSAs); the maximum force is evaluated by cavity growth at the interface between the PSA layer and the probe surface. As the PSA layer becomes thinner, it is more difficult to measure the tack with a cylindrical probe because of the uneven contact resulting from misalignment. A spherical probe is preferable to obtain reproducible contact on the PSA layer, but the contact area should be taken into account if the contact pressure affects the tack performance. Tack was measured on PSAs with various thicknesses in different contact areas to clarify their effect. The results showed that a larger contact area on a thinner PSA generated higher adhesive stress with larger strain. It was found that the maximum adhesive stress was not affected by the contact pressure, but it was strongly correlated to the contact radius divided by the PSA thickness. In addition, a video microscope observation showed that, in all of the experimental cases, the adhesive stress always reached the maximum when cavities were generated at the interface between the PSA and probe surface. Therefore, the criterion of cavity growth was introduced for the evaluation of the maximum adhesive stress. As a result, the experimental results, even at different release rates, were in good agreement with the estimation by considering the effect of confining a thin layer. Furthermore, the theoretical estimation indicated the ultimate value, which was not dependent upon the PSA thickness or contact area. It was defined as a material property, referred to as the "ultimate tack strength" of PSAs.

  2. Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector

    DOE PAGES

    Aad, G.

    2015-07-17

    The measurements of the ZZ and WW final states in the mass range above the \\(2m_Z\\) and \\(2m_W\\) thresholds provide a unique opportunity to measure the off-shell coupling strength of the Higgs boson. This paper presents constraints on the off-shell Higgs boson event yields normalised to the Standard Model prediction (signal strength) in the \\(ZZ \\rightarrow 4\\ell \\), \\(ZZ\\rightarrow 2\\ell 2\

  3. Laser heterodyne interferometric signal processing method based on rising edge locking with high frequency clock signal.

    PubMed

    Zhang, Enzheng; Chen, Benyong; Yan, Liping; Yang, Tao; Hao, Qun; Dong, Wenjun; Li, Chaorong

    2013-02-25

    A novel phase measurement method composed of the rising-edge locked signal processing and the digital frequency mixing is proposed for laser heterodyne interferometer. The rising-edge locked signal processing, which employs a high frequency clock signal to lock the rising-edges of the reference and measurement signals, not only can improve the steepness of the rising-edge, but also can eliminate the error counting caused by multi-rising-edge phenomenon in fringe counting. The digital frequency mixing is realized by mixing the digital interference signal with a digital base signal that is different from conventional frequency mixing with analogue signals. These signal processing can improve the measurement accuracy and enhance anti-interference and measurement stability. The principle and implementation of the method are described in detail. An experimental setup was constructed and a series of experiments verified the feasibility of the method in large displacement measurement with high speed and nanometer resolution.

  4. A Comparison of Base Strengths Using Visual and EMF Observations

    ERIC Educational Resources Information Center

    Campbell, J. A.

    1975-01-01

    Describes a series of experiments which provide excellent evidence for different degrees of dissociation of a series of complexes and precipitate. The series is based on the copper ion as the acid and sample data are provided. (GS)

  5. Development and application of high strength ternary boride base cermets

    SciTech Connect

    Takagi, Ken-ichi . E-mail: u4381@toyokohan.co.jp

    2006-09-15

    Reaction boronizing sintering is a novel strategy to form a ternary boride coexisting with a metal matrix in a cermet during liquid phase sintering. This new sintering technique has successfully developed world first ternary boride base cermets with excellent mechanical properties such as Mo{sub 2}FeB{sub 2}, Mo{sub 2}NiB{sub 2} and WCoB base ones. In these cermets Mo{sub 2}FeB{sub 2} and Mo{sub 2}NiB{sub 2} base ones consist of a tetragonal M {sub 3}B{sub 2} (M: metal)-type complex boride as a hard phase and a transition metal base matrix. The cermets have already been applied to wear resistant applications such as injection molding machine parts, can making tools, and hot copper extruding dies, etc. This paper focuses on the characteristics, effects of the additional elements on the mechanical properties and structure, and practical applications of the ternary boride base cermets. - Graphical abstract: TRS and hardness of Ni-5B-51Mo-17.5Cr and Ni-5B-51Mo-12.5Cr-5V-xMn mass% cermets as functions of Mn content (Fig. 17)

  6. Cortical and subcortical contributions to state- and strength-based perceptual judgments

    PubMed Central

    Aly, Mariam; Wansard, Murielle; Segovia, Fermín; Yonelinas, Andrew P.; Bastin, Christine

    2014-01-01

    Perceptual judgments can be made on the basis of different kinds of information: state-based access to specific details that differentiate two similar images, or strength-based assessments of relational match/mismatch. We explored state- and strength-based perception in eleven right-hemisphere stroke patients, and examined lesion overlap images to gain insight into the neural underpinnings of these different kinds of perceptual judgments. Patients and healthy controls were presented with pairs of scenes that were either identical or differed in that one scene was slightly expanded or contracted relative to the other. Same/different confidence judgments were used to plot receiver-operating characteristics and estimate the contributions of state- and strength-based perception. The patient group showed a significant and selective impairment of strength-based, but not state-based, perception. This finding was not an artifact of reduced levels of overall performance, because matching perceptual discriminability levels between controls and patients revealed a double dissociation, with higher state-based, and lower strength-based, perception in patients versus controls. We then conducted exploratory follow-up analyses on the patient group, based on the observation of substantial individual differences in state-based perception — differences that were masked in analyses based on the group mean. Patients who were relatively spared in state-based perception (but impaired in strength-based perception) had damage that was primarily in temporo-parietal cortical regions. Patients who were relatively impaired in both state- and strength-based perception had overlapping damage in the thalamus, putamen, and adjacent white matter. These patient groups were not different in any other measure, e.g., presence of spatial neglect symptoms, age, education, lesion volume, or time since stroke. These findings shed light on the different roles of right hemisphere regions in high

  7. A Renewed Focus on Strengths-Based Assessment in Schools

    ERIC Educational Resources Information Center

    Climie, Emma; Henley, Laura

    2016-01-01

    School-based practitioners are often called upon to provide assessment and recommendations for struggling students. These assessments often open doors to specialised services or interventions and provide opportunities for students to build competencies in areas of need. However, these assessments often fail to highlight the abilities of these…

  8. Strengths-based positive psychology interventions: a randomized placebo-controlled online trial on long-term effects for a signature strengths- vs. a lesser strengths-intervention.

    PubMed

    Proyer, René T; Gander, Fabian; Wellenzohn, Sara; Ruch, Willibald

    2015-01-01

    Recent years have seen an increasing interest in research in positive psychology interventions. There is broad evidence for their effectiveness in increasing well-being and ameliorating depression. Intentional activities that focus on those character strengths, which are most typical for a person (i.e., signature strengths, SS) and encourage their usage in a new way have been identified as highly effective. The current study aims at comparing an intervention aimed at using SS with one on using individual low scoring (or lesser) strengths in a randomized placebo-controlled trial. A total of 375 adults were randomly assigned to one of the two intervention conditions [i.e., using five signature vs. five lesser strengths (LS) in a new way] or a placebo control condition (i.e., early memories). We measured happiness and depressive symptoms at five time points (i.e., pre- and post-test, 1-, 3-, and 6-months follow-ups) and character strengths at pre-test. The main findings are that (1) there were increases in happiness for up to 3 months and decreases in depressive symptoms in the short term in both intervention conditions; (2) participants found working with strengths equally rewarding (enjoyment and benefit) in both conditions; (3) those participants that reported generally higher levels of strengths benefitted more from working on LS rather than SS and those with comparatively lower levels of strengths tended to benefit more from working on SS; and (4) deviations from an average profile derived from a large sample of German-speakers completing the Values-in-Action Inventory of Strengths were associated with greater benefit from the interventions in the SS-condition. We conclude that working on character strengths is effective for increasing happiness and discuss how these interventions could be tailored to the individual for promoting their effectiveness.

  9. Strengths-based positive psychology interventions: a randomized placebo-controlled online trial on long-term effects for a signature strengths- vs. a lesser strengths-intervention

    PubMed Central

    Proyer, René T.; Gander, Fabian; Wellenzohn, Sara; Ruch, Willibald

    2015-01-01

    Recent years have seen an increasing interest in research in positive psychology interventions. There is broad evidence for their effectiveness in increasing well-being and ameliorating depression. Intentional activities that focus on those character strengths, which are most typical for a person (i.e., signature strengths, SS) and encourage their usage in a new way have been identified as highly effective. The current study aims at comparing an intervention aimed at using SS with one on using individual low scoring (or lesser) strengths in a randomized placebo-controlled trial. A total of 375 adults were randomly assigned to one of the two intervention conditions [i.e., using five signature vs. five lesser strengths (LS) in a new way] or a placebo control condition (i.e., early memories). We measured happiness and depressive symptoms at five time points (i.e., pre- and post-test, 1-, 3-, and 6-months follow-ups) and character strengths at pre-test. The main findings are that (1) there were increases in happiness for up to 3 months and decreases in depressive symptoms in the short term in both intervention conditions; (2) participants found working with strengths equally rewarding (enjoyment and benefit) in both conditions; (3) those participants that reported generally higher levels of strengths benefitted more from working on LS rather than SS and those with comparatively lower levels of strengths tended to benefit more from working on SS; and (4) deviations from an average profile derived from a large sample of German-speakers completing the Values-in-Action Inventory of Strengths were associated with greater benefit from the interventions in the SS-condition. We conclude that working on character strengths is effective for increasing happiness and discuss how these interventions could be tailored to the individual for promoting their effectiveness. PMID:25954221

  10. GPR-based evaluation of strength properties of unbound pavement material from electrical characteristics

    NASA Astrophysics Data System (ADS)

    Benedetto, Andrea; D'Amico, Fabrizio; Tosti, Fabio

    2013-04-01

    the use of road material, typically employed for subgrade and subbase courses. Different types of soil ranging from group A1 to A4 by AASHTO soil classification system, are analyzed. As regards the laboratory experiments, material is gradually compacted in electrically and hydraulically isolated test boxes. A large metal sheet supports the experimental boxes, so that the transmitted GPR signal is totally reflected. GPR inspections are carried out for any compaction step up to the maximum density value available. Moreover, in-situ tests are carried out on targeted types of soil, with grain size distribution and texture comparable to those analyzed in laboratory environment. The results of this study confirm a promising correlation between the electric permittivities and the strength and deformation properties of the surveyed soils. Laboratory analyses show that the relationship between the relative permittivity and the bulk density is positive: the higher the density of the compacted soil sample, the higher the electric permittivity of the medium. Analogously, in-situ validation presents a good comparison between measured and predicted data. Percentage errors less than 20% demonstrate that a reliable prediction of Young Modulus using this GPR-based approach can be achieved.

  11. Scratch-resistant, highly conductive, and high-strength carbon nanotube-based composite yarns.

    PubMed

    Liu, Kai; Sun, Yinghui; Lin, Xiaoyang; Zhou, Ruifeng; Wang, Jiaping; Fan, Shoushan; Jiang, Kaili

    2010-10-26

    High-strength and conductive carbon nanotube (CNT) yarns are very attractive in many potential applications. However, there is a difficulty when simultaneously enhancing the strength and conductivity of CNT yarns. Adding some polymers into CNT yarns to enhance their strength will decrease their conductivity, while treating them in acid or coating them with metal nanoparticles to enhance their conductivity will reduce their strength. To overcome this difficulty, here we report a method to make high-strength and highly conductive CNT-based composite yarns by using a continuous superaligned CNT (SACNT) yarn as a conductive framework and then inserting polyvinyl alcohol (PVA) into the intertube spaces of the framework through PVA/dimethyl sulphoxide solution to enhance the strength of yarns. The as-produced CNT/PVA composite yarns possess very high tensile strengths up to 2.0 GPa and Young's moduli more than 120 GPa, much higher than those of the CNT/PVA yarns reported. The electric conductivity of as-produced composite yarns is as high as 9.2 × 10(4) S/m, comparable to HNO(3)-treated or Au nanoparticle-coated CNT yarns. These composite yarns are flexible, lightweight, scratch-resistant, very stable in the lab environment, and resistant to extremely humid ambient and as a result can be woven into high-strength and heatable fabrics, showing potential applications in flexible heaters, bullet-proof vests, radiation protection suits, and spacesuits.

  12. A magnetoelectric composite based signal generator

    NASA Astrophysics Data System (ADS)

    Fetisov, Y. K.; Serov, V. N.; Fetisov, L. Y.; Makovkin, S. A.; Viehland, D.; Srinivasan, G.

    2016-05-01

    Self-oscillations in an active loop consisting of a wide-band amplifier and a magnetoelectric composite in the feedback circuit have been observed. The composite with a ferroelectric lead zirconate titanate bimorph and ferromagnetic Metglas serves as a resonator that determines the frequency of oscillations and provides the feedback voltage. Under amplitude balance and phase matching conditions, the device generated signals at 2.3 kHz, at the bending resonance frequency of the composite. The oscillations were observed over a specific range of magnetic bias H. The shape of the signal generated is dependent on electrical circuit parameters and magnitude and orientation of H.

  13. Bond and fatigue characteristics of high-strength cement-based composites

    SciTech Connect

    Chimamphant, S.D.

    1989-01-01

    The results of a series of tests on a variety of high strength cementitious composites yield a model from which an empirical equation of general normalized pull-out stress vs. pull-out displacement relationship is developed. A new variable named the Brittleness Index and is defined and used in the proposed equation. Additionally, the concept of maximum strain is used to predict the fatigue life of high strength concrete. Three sizes of deformed bars and two types of steel fiber with four different volume fractions were used to observe bond-slip and pull-out characteristics of high strength concrete. The results indicate that the maximum slippage of deformed bars is only about 10% of that observed in normal concrete. Consequently, the required development length may have to be longer for high strength concrete members as compared to normal concrete. For the fatigue characteristics study, standard 3 x 6 in. cylinders were tested at the rates of 6 and 12 Hz. in a closed-loop load-controlled system. The results show that as the compressive strength of the composites increases from 4000 to 11000 psi., the fatigue strength increases by 17 percents. The rate of loading does not significantly affect the S-N relationship, fatigue strength and fatigue limit of the high strength cement-based composites. The S-N curves of high strength concrete shows a faster decay rate than those of normal concrete. The maximum strain at any cycle under cyclic loading is always less than the maximum strain at failure under monotonic loading. Also observed is that the maximum strain-cycle relationship is linear. These results indicate that the design code for flexure of normal concrete cannot be applied to high strength concrete.

  14. Effects of concurrent strength and endurance training on genes related to myostatin signaling pathway and muscle fiber responses.

    PubMed

    de Souza, Eduardo O; Tricoli, Valmor; Aoki, Marcelo S; Roschel, Hamilton; Brum, Patrícia C; Bacurau, Aline V N; Silva-Batista, Carla; Wilson, Jacob M; Neves, Manoel; Soares, Antonio G; Ugrinowitsch, Carlos

    2014-11-01

    Concurrent training (CT) seems to impair training-induced muscle hypertrophy. This study compared the effects of CT, strength training (ST) and interval training (IT) on the muscle fiber cross-sectional area (CSA) response, and on the expression of selected genes involved in the myostatin (MSTN) signaling mRNA levels. Thirty-seven physically active men were randomly divided into 4 groups: CT (n = 11), ST (n = 11), IT (n = 8), and control group (C) (n = 7) and underwent an 8-week training period. Vastus lateralis biopsy muscle samples were obtained at baseline and 48 hours after the last training session. Muscle fiber CSA, selected genes expression, and maximum dynamic ST (1 repetition maximum) were evaluated before and after training. Type IIa and type I muscle fiber CSA increased from pre- to posttest only in the ST group (17.08 and 17.9%, respectively). The SMAD-7 gene expression significantly increased at the posttest in the ST (53.9%) and CT groups (39.3%). The MSTN and its regulatory genes ActIIb, FLST-3, FOXO-3a, and GASP-1 mRNA levels remained unchanged across time and groups. One repetition maximum increased from pre- to posttest in both the ST and CT groups (ST = 18.5%; CT = 17.6%). Our findings are suggestive that MSTN and their regulatory genes at transcript level cannot differentiate muscle fiber CSA responses between CT and ST regimens in humans. PMID:24832980

  15. Effects of concurrent strength and endurance training on genes related to myostatin signaling pathway and muscle fiber responses.

    PubMed

    de Souza, Eduardo O; Tricoli, Valmor; Aoki, Marcelo S; Roschel, Hamilton; Brum, Patrícia C; Bacurau, Aline V N; Silva-Batista, Carla; Wilson, Jacob M; Neves, Manoel; Soares, Antonio G; Ugrinowitsch, Carlos

    2014-11-01

    Concurrent training (CT) seems to impair training-induced muscle hypertrophy. This study compared the effects of CT, strength training (ST) and interval training (IT) on the muscle fiber cross-sectional area (CSA) response, and on the expression of selected genes involved in the myostatin (MSTN) signaling mRNA levels. Thirty-seven physically active men were randomly divided into 4 groups: CT (n = 11), ST (n = 11), IT (n = 8), and control group (C) (n = 7) and underwent an 8-week training period. Vastus lateralis biopsy muscle samples were obtained at baseline and 48 hours after the last training session. Muscle fiber CSA, selected genes expression, and maximum dynamic ST (1 repetition maximum) were evaluated before and after training. Type IIa and type I muscle fiber CSA increased from pre- to posttest only in the ST group (17.08 and 17.9%, respectively). The SMAD-7 gene expression significantly increased at the posttest in the ST (53.9%) and CT groups (39.3%). The MSTN and its regulatory genes ActIIb, FLST-3, FOXO-3a, and GASP-1 mRNA levels remained unchanged across time and groups. One repetition maximum increased from pre- to posttest in both the ST and CT groups (ST = 18.5%; CT = 17.6%). Our findings are suggestive that MSTN and their regulatory genes at transcript level cannot differentiate muscle fiber CSA responses between CT and ST regimens in humans.

  16. Strengths and limitations of evidence-based dermatology.

    PubMed

    Williams, Hywel C

    2014-03-01

    The need for understanding and reflecting on evidence-based dermatology (EBD) has never been greater given the exponential growth of new external evidence to inform clinical practice. Like any other branch of medicine, dermatologists need to acquire new skills in constructing answerable questions, efficiently searching electronic bibliographic databases, and critically appraising different types of studies. Secondary summaries of evidence in the form of systematic reviews (SR), that is, reviews that are conducted in a systematic, unbiased and explicit manner, reside at the top of the evidence hierarchy, because they are less prone to bias than traditional expert reviews. In addition to providing summaries of the best external evidence, systematic reviews and randomized controlled trials (RCTs) are also powerful ways of identifying research gaps and ultimately setting the agenda of future clinical research in dermatology. But like any paradigm, EBD can have its limitations. Wrong application, misuse and overuse of EBD can have serious consequences. For example, mindless pooling together of data from dissimilar studies in a meta-analysis may render it a form of reductionism that does not make any sense. Similarly, even highly protocolised study designs such as SRs and RCTs are still susceptible to some degree of dishonesty and bias. Over-reliance on randomized controlled trials (RCT) may be inappropriate, as RCTs are not a good source for picking up rare but important adverse effects such as lupus syndrome with minocycline. A common criticism leveled against SRs is that these frequently conclude that there is lack of sufficient evidence to inform current clinical practice, but arguably, such a perception is grounded more on the interpretation of the SRs than anything else. The apparent absence of evidence should not paralyze the dermatologist to adopt a state of therapeutic nihilism. Poor primary data and an SR based on evidence that is not up-to-date are also

  17. Strengths and Limitations of Evidence-Based Dermatology

    PubMed Central

    Williams, Hywel C

    2014-01-01

    The need for understanding and reflecting on evidence-based dermatology (EBD) has never been greater given the exponential growth of new external evidence to inform clinical practice. Like any other branch of medicine, dermatologists need to acquire new skills in constructing answerable questions, efficiently searching electronic bibliographic databases, and critically appraising different types of studies. Secondary summaries of evidence in the form of systematic reviews (SR), that is, reviews that are conducted in a systematic, unbiased and explicit manner, reside at the top of the evidence hierarchy, because they are less prone to bias than traditional expert reviews. In addition to providing summaries of the best external evidence, systematic reviews and randomized controlled trials (RCTs) are also powerful ways of identifying research gaps and ultimately setting the agenda of future clinical research in dermatology. But like any paradigm, EBD can have its limitations. Wrong application, misuse and overuse of EBD can have serious consequences. For example, mindless pooling together of data from dissimilar studies in a meta-analysis may render it a form of reductionism that does not make any sense. Similarly, even highly protocolised study designs such as SRs and RCTs are still susceptible to some degree of dishonesty and bias. Over-reliance on randomized controlled trials (RCT) may be inappropriate, as RCTs are not a good source for picking up rare but important adverse effects such as lupus syndrome with minocycline. A common criticism leveled against SRs is that these frequently conclude that there is lack of sufficient evidence to inform current clinical practice, but arguably, such a perception is grounded more on the interpretation of the SRs than anything else. The apparent absence of evidence should not paralyze the dermatologist to adopt a state of therapeutic nihilism. Poor primary data and an SR based on evidence that is not up-to-date are also

  18. Enacting Firm, Fair and Friendly Practice: A Model for Strengths-Based Child Protection Relationships?

    PubMed Central

    Oliver, Carolyn; Charles, Grant

    2016-01-01

    Strengths-based solution-focused approaches are gaining ground in statutory child protection work, but few studies have asked front line practitioners how they navigate the complex worker–client relationships such approaches require. This paper describes one component of a mixed-methods study in a large Canadian statutory child protection agency in which 225 workers described how they applied the ideas of strengths-based practice in their daily work. Interviews with twenty-four practitioners were analysed using an interpretive description approach. Only four interviewees appeared to successfully enact a version of strengths-based practice that closely mirrored those described by key strengths-based child protection theorists and was fully congruent with their mandated role. They described navigating a shifting balance of collaboration and authority in worker–client relationships based on transparency, impartial judgement, attentiveness to the worker–client interaction and the value that clients were fellow human beings. Their accounts extend current conceptualisations of the worker–client relationship in strengths-based child protection work and are congruent with current understandings of effective mandated relationships. They provide what may be a useful model to help workers understand and navigate relationships in which they must reconcile their own authority and expertise with genuine support for the authority and expertise of their clients. PMID:27559211

  19. Composite Stress Rupture: A New Reliability Model Based on Strength Decay

    NASA Technical Reports Server (NTRS)

    Reeder, James R.

    2012-01-01

    A model is proposed to estimate reliability for stress rupture of composite overwrap pressure vessels (COPVs) and similar composite structures. This new reliability model is generated by assuming a strength degradation (or decay) over time. The model suggests that most of the strength decay occurs late in life. The strength decay model will be shown to predict a response similar to that predicted by a traditional reliability model for stress rupture based on tests at a single stress level. In addition, the model predicts that even though there is strength decay due to proof loading, a significant overall increase in reliability is gained by eliminating any weak vessels, which would fail early. The model predicts that there should be significant periods of safe life following proof loading, because time is required for the strength to decay from the proof stress level to the subsequent loading level. Suggestions for testing the strength decay reliability model have been made. If the strength decay reliability model predictions are shown through testing to be accurate, COPVs may be designed to carry a higher level of stress than is currently allowed, which will enable the production of lighter structures

  20. Comparison of flexural strength in three types of denture base resins: An in vitro study

    PubMed Central

    Jaikumar, R. Arun; Karthigeyan, Suma; Ali, Syed Asharf; Naidu, N. Madhulika; Kumar, R. Pradeep; Vijayalakshmi, K.

    2015-01-01

    Aim: The aim of this study was to evaluate whether the flexural strength of a commercially available, heat polymerized acrylic denture base material could be improved using reinforcements. Materials and Methods: A total of 30 specimens (65 mm × 10 mm × 3 mm) were fabricated; the specimens were divided into three groups with 10 specimens each. They were Group 1 - conventional denture base resins, Group 2 - high impact denture base resins, and Group 3 - glass reinforced denture base resins. The specimens were loaded until failure on a three-point bending test machine. An one-way analysis of variance was used to determine statistical differences among the flexural strength of three groups. Data were analyzed by SPSS software version 21.0© (IBM Corporation, Armonk, NY, USA) and the results were obtained. Results: The flexural strength values showed statistically significant differences among experimental groups (P < 0.005). Conclusion: Within the limitations of the study polymethyl methacrylate (PMMA) reinforced with glass fibers showed the highest flexural strength values this was followed by PMMA reinforced with butadiene styrene, and the least strength was observed in the conventional denture base resins. PMID:26538898

  1. Physically-based strength model of tantalum incorporating effects of temperature, strain rate and pressure

    DOE PAGES

    Lim, Hojun; Battaile, Corbett C.; Brown, Justin L.; Weinberger, Christopher R.

    2016-06-14

    In this work, we develop a tantalum strength model that incorporates e ects of temperature, strain rate and pressure. Dislocation kink-pair theory is used to incorporate temperature and strain rate e ects while the pressure dependent yield is obtained through the pressure dependent shear modulus. Material constants used in the model are parameterized from tantalum single crystal tests and polycrystalline ramp compression experiments. It is shown that the proposed strength model agrees well with the temperature and strain rate dependent yield obtained from polycrystalline tantalum experiments. Furthermore, the model accurately reproduces the pressure dependent yield stresses up to 250 GPa.more » The proposed strength model is then used to conduct simulations of a Taylor cylinder impact test and validated with experiments. This approach provides a physically-based multi-scale strength model that is able to predict the plastic deformation of polycrystalline tantalum through a wide range of temperature, strain and pressure regimes.« less

  2. Can the Accuracy of Home Blood Glucose Monitors be affected by the Received Signal Strength of 900 MHz GSM Mobile Phones?

    PubMed Central

    Eslami, J.; Ghafaripour, F.; Mortazavi, S.A.R.; Mortazavi, S.M.J.; Shojaei-fard, M.B.

    2015-01-01

    Background People who use home blood glucose monitors may use their mobile phones in the close vicinity of medical devices. This study is aimed at investigating the effect of the signal strength of 900 MHz GSM mobile phones on the accuracy of home blood glucose monitors. Methods Sixty non-diabetic volunteer individuals aged 21 - 28 years participated in this study. Blood samples were analyzed for glucose level by using a common blood glucose monitoring system. Each blood sample was analyzed twice, within ten minutes in presence and absence of electromagnetic fields generated by a common GSM mobile phone during ringing. Blood samples were divided into 3 groups of 20 samples each. Group 1: exposure to mobile phone radiation with weak signal strength. Group2: exposure to mobile phone radiation with strong signal strength. Group3: exposure to a switched–on mobile phone with no signal strength. Results The magnitude of the changes in the first, second and third group between glucose levels of two measurements (׀ΔC׀) were 7.4±3.9 mg/dl, 10.2±4.5 mg/dl, 8.7±8.4 mg/dl respectively. The difference in the magnitude of the changes between the 1st and the 3rd groups was not statistically significant. Furthermore, the difference in the magnitude of the changes between the 2nd and the 3rd groups was not statistically significant. Conclusion Findings of this study showed that the signal strength of 900 MHz GSM mobile phones cannot play a significant role in changing the accuracy of home blood glucose monitors. PMID:26688798

  3. Strengths-Based School Counseling and the ASCA National Model[R

    ERIC Educational Resources Information Center

    Galassi, John P.; Griffin, Dana; Akos, Patrick

    2008-01-01

    Articles in this special issue illustrate how Strengths-Based School Counseling complements the ASCA National Model[R] by strengthening the foundation of comprehensive school counseling programs, emphasizing promotion-oriented delivery, reinforcing the accountability and evidence base, engaging in developmental advocacy, and highlighting the…

  4. Statistical-uncertainty-based adaptive filtering of lidar signals

    SciTech Connect

    Fuehrer, P. L.; Friehe, C. A.; Hristov, T. S.; Cooper, D. I.; Eichinger, W. E.

    2000-02-10

    An adaptive filter signal processing technique is developed to overcome the problem of Raman lidar water-vapor mixing ratio (the ratio of the water-vapor density to the dry-air density) with a highly variable statistical uncertainty that increases with decreasing photomultiplier-tube signal strength and masks the true desired water-vapor structure. The technique, applied to horizontal scans, assumes only statistical horizontal homogeneity. The result is a variable spatial resolution water-vapor signal with a constant variance out to a range limit set by a specified signal-to-noise ratio. The technique was applied to Raman water-vapor lidar data obtained at a coastal pier site together with in situ instruments located 320 m from the lidar. The micrometerological humidity data were used to calibrate the ratio of the lidar gains of the H{sub 2}O and the N{sub 2} photomultiplier tubes and set the water-vapor mixing ratio variance for the adaptive filter. For the coastal experiment the effective limit of the lidar range was found to be approximately 200 m for a maximum noise-to-signal variance ratio of 0.1 with the implemented data-reduction procedure. The technique can be adapted to off-horizontal scans with a small reduction in the constraints and is also applicable to other remote-sensing devices that exhibit the same inherent range-dependent signal-to-noise ratio problem. (c) 2000 Optical Society of America.

  5. Statistical-uncertainty-based adaptive filtering of lidar signals.

    PubMed

    Fuehrer, P L; Friehe, C A; Hristov, T S; Cooper, D I; Eichinger, W E

    2000-02-10

    An adaptive filter signal processing technique is developed to overcome the problem of Raman lidar water-vapor mixing ratio (the ratio of the water-vapor density to the dry-air density) with a highly variable statistical uncertainty that increases with decreasing photomultiplier-tube signal strength and masks the true desired water-vapor structure. The technique, applied to horizontal scans, assumes only statistical horizontal homogeneity. The result is a variable spatial resolution water-vapor signal with a constant variance out to a range limit set by a specified signal-to-noise ratio. The technique was applied to Raman water-vapor lidar data obtained at a coastal pier site together with in situ instruments located 320 m from the lidar. The micrometeorological humidity data were used to calibrate the ratio of the lidar gains of the H(2)O and the N(2) photomultiplier tubes and set the water-vapor mixing ratio variance for the adaptive filter. For the coastal experiment the effective limit of the lidar range was found to be approximately 200 m for a maximum noise-to-signal variance ratio of 0.1 with the implemented data-reduction procedure. The technique can be adapted to off-horizontal scans with a small reduction in the constraints and is also applicable to other remote-sensing devices that exhibit the same inherent range-dependent signal-to-noise ratio problem.

  6. Detectability of CO2 Flux Signals by a Space-Based Lidar Mission

    NASA Technical Reports Server (NTRS)

    Hammerling, Dorit M.; Kawa, S. Randolph; Schaefer, Kevin; Doney, Scott; Michalak, Anna M.

    2015-01-01

    Satellite observations of carbon dioxide (CO2) offer novel and distinctive opportunities for improving our quantitative understanding of the carbon cycle. Prospective observations include those from space-based lidar such as the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. Here we explore the ability of such a mission to detect regional changes in CO2 fluxes. We investigate these using three prototypical case studies, namely the thawing of permafrost in the Northern High Latitudes, the shifting of fossil fuel emissions from Europe to China, and changes in the source-sink characteristics of the Southern Ocean. These three scenarios were used to design signal detection studies to investigate the ability to detect the unfolding of these scenarios compared to a baseline scenario. Results indicate that the ASCENDS mission could detect the types of signals investigated in this study, with the caveat that the study is based on some simplifying assumptions. The permafrost thawing flux perturbation is readily detectable at a high level of significance. The fossil fuel emission detectability is directly related to the strength of the signal and the level of measurement noise. For a nominal (lower) fossil fuel emission signal, only the idealized noise-free instrument test case produces a clearly detectable signal, while experiments with more realistic noise levels capture the signal only in the higher (exaggerated) signal case. For the Southern Ocean scenario, differences due to the natural variability in the ENSO climatic mode are primarily detectable as a zonal increase.

  7. Physics-based signal processing algorithms for micromachined cantilever arrays

    DOEpatents

    Candy, James V; Clague, David S; Lee, Christopher L; Rudd, Robert E; Burnham, Alan K; Tringe, Joseph W

    2013-11-19

    A method of using physics-based signal processing algorithms for micromachined cantilever arrays. The methods utilize deflection of a micromachined cantilever that represents the chemical, biological, or physical element being detected. One embodiment of the method comprises the steps of modeling the deflection of the micromachined cantilever producing a deflection model, sensing the deflection of the micromachined cantilever and producing a signal representing the deflection, and comparing the signal representing the deflection with the deflection model.

  8. Inconsistency in the strength testing of dental resin-based composites among researchers

    PubMed Central

    Kumar, Naresh

    2013-01-01

    The aims of this paper were to review the current strength testing methods of the dental resin-based composites (RBCs) and to explore the inconsistencies with regard to strength testing among researchers. Data selection/extraction: An outline of the most relevant aspects of RBCs was created, and a subsequent literature search for articles published during last four decades (1970-2010) was conducted using the databases, namely PubMed, Science Direct and ISI Web of Knowledge. Conclusion: The literature review highlighted a lack of consensus among researchers regarding the reliability of ISO recommended three-point flexure strength testing method. Several investigators have used Weibull statistics for the analysis of RBCs strength data, however their applicability might be questioned as many RBCs contain greater resin content and may exhibit sufficient viscous deformation prior to brittle failure. In addition, variability in the selection of cross-head speed and mould material for strength testing was evident which may lead to variation in the strength data and render the interpretation difficult among researchers. PMID:24353541

  9. A new EEG synchronization strength analysis method: S-estimator based normalized weighted-permutation mutual information.

    PubMed

    Cui, Dong; Pu, Weiting; Liu, Jing; Bian, Zhijie; Li, Qiuli; Wang, Lei; Gu, Guanghua

    2016-10-01

    Synchronization is an important mechanism for understanding information processing in normal or abnormal brains. In this paper, we propose a new method called normalized weighted-permutation mutual information (NWPMI) for double variable signal synchronization analysis and combine NWPMI with S-estimator measure to generate a new method named S-estimator based normalized weighted-permutation mutual information (SNWPMI) for analyzing multi-channel electroencephalographic (EEG) synchronization strength. The performances including the effects of time delay, embedding dimension, coupling coefficients, signal to noise ratios (SNRs) and data length of the NWPMI are evaluated by using Coupled Henon mapping model. The results show that the NWPMI is superior in describing the synchronization compared with the normalized permutation mutual information (NPMI). Furthermore, the proposed SNWPMI method is applied to analyze scalp EEG data from 26 amnestic mild cognitive impairment (aMCI) subjects and 20 age-matched controls with normal cognitive function, who both suffer from type 2 diabetes mellitus (T2DM). The proposed methods NWPMI and SNWPMI are suggested to be an effective index to estimate the synchronization strength.

  10. A new EEG synchronization strength analysis method: S-estimator based normalized weighted-permutation mutual information.

    PubMed

    Cui, Dong; Pu, Weiting; Liu, Jing; Bian, Zhijie; Li, Qiuli; Wang, Lei; Gu, Guanghua

    2016-10-01

    Synchronization is an important mechanism for understanding information processing in normal or abnormal brains. In this paper, we propose a new method called normalized weighted-permutation mutual information (NWPMI) for double variable signal synchronization analysis and combine NWPMI with S-estimator measure to generate a new method named S-estimator based normalized weighted-permutation mutual information (SNWPMI) for analyzing multi-channel electroencephalographic (EEG) synchronization strength. The performances including the effects of time delay, embedding dimension, coupling coefficients, signal to noise ratios (SNRs) and data length of the NWPMI are evaluated by using Coupled Henon mapping model. The results show that the NWPMI is superior in describing the synchronization compared with the normalized permutation mutual information (NPMI). Furthermore, the proposed SNWPMI method is applied to analyze scalp EEG data from 26 amnestic mild cognitive impairment (aMCI) subjects and 20 age-matched controls with normal cognitive function, who both suffer from type 2 diabetes mellitus (T2DM). The proposed methods NWPMI and SNWPMI are suggested to be an effective index to estimate the synchronization strength. PMID:27451314

  11. Dentinal shear bond strength, microleakage, and contraction gap of visible light-polymerized liners/bases.

    PubMed

    Cooley, R L; Barkmeier, W W

    1991-06-01

    The bond strength and microleakage patterns of three light-curing glass-ionomer cement liners/bases (Vitrebond, XR Ionomer, and Zionomer) were evaluated and compared to a fluoride-releasing resin (TimeLine) designed for the same use. Bond strength tests were performed at 24 hours and 7 days. At 24 hours Vitrebond, Time-Line, and Zionomer had statistically significantly greater bond strengths than XR Ionomer. At 7 days, Vitrebond had a statistically significantly stronger bond than the others. Microleakage was evaluated after 24 hours of thermocycling. Vitrebond and XR Ionomer had statistically significantly less leakage than the others, while TimeLine had significantly more leakage than the others. Polymerization contraction gaps between the liners/bases and dentin were examined with scanning electron microscopy. Contraction gaps were approximately 10 microns with Vitrebond and XR Ionomer and 5 microns with TimeLine. A contraction gap generally was not observed with Zionomer.

  12. Nonlinear stimulated Brillouin scattering based photonic signal processors

    SciTech Connect

    Minasian, Robert A.

    2014-10-06

    Recent new methods in photonic signal processing based on stimulated Brillouin scattering, that enable the realization of photonic mixers with high conversion efficiency, ultra-wide continuously tunable high-resolution microwave photonic filters and programmable switchable microwave photonic tunable filters, are presented. These processors provide new capabilities for the realisation of high-performance and high-resolution signal processing.

  13. Evaluating Land-Atmosphere Coupling Strength Over CONUS Using Satellite-based Remote Sensing

    NASA Astrophysics Data System (ADS)

    Wood, E. F.; Ferguson, C.

    2008-12-01

    Understanding the coupling strength between land and its overlying boundary layer is important to establishing the role of the surface state in boundary layer development and related processes. Much of our current understanding has resulted from model diagnostics carried out by Alan K. Betts using the European Center's (ECMWF) forecast and reanalysis model outputs. Other model based analysis under the GEWEX Land Atmospheric Coupling Experiments (GLACE), lead by Randy Koster, has suggested that models with strong coupling have inferred "hot spots" that imply enhanced predictability of seasonal precipitation. Other analysis (Mitchell, personal communication) suggests that models with strong coupling fail to represent the observed diurnal cycle of precipitation across the central U.S. Dirmeyer et al. in 2006 compared the coupling strength (using Betts" measure that relates surface soil moisture to the lifting condensation level (LCL) pressure) for a number of models from the GLACE experiment, which showed a wide range of strength. This presentation utilizes space-based remote sensing (RS) observations to estimate the strength of warm season land-atmosphere coupling over the continental US. The remote sensing products are derived from the suite of sensors on-board NASA Aqua, including AMSR-E (soil moisture), AIRS (relative humidity, air temperature, skin temperature), MODIS (LAI, NDVI), and CERES (radiation). The relative strength of coupling is quantified in terms of observational diagnostics set forth by the work of Alan Betts, based on his work with the ERA40 model output data set, and Fendall and Eltahir, based on radiosonde data. While the analysis covers the continental US (CONUS), emphasis is placed on the southern Great Plains where dense in-situ measurements enable direct comparison between coupling strengths obtained from ground observations and those from remote sensing, and a region that previous studies by Koster et al. have inferred to be a coupling "hot

  14. The Reinforcement Effect of Nano-Zirconia on the Transverse Strength of Repaired Acrylic Denture Base.

    PubMed

    Gad, Mohammed; ArRejaie, Aws S; Abdel-Halim, Mohamed Saber; Rahoma, Ahmed

    2016-01-01

    Objective. The aim of this study was to evaluate the effect of incorporation of glass fiber, zirconia, and nano-zirconia on the transverse strength of repaired denture base. Materials and Methods. Eighty specimens of heat polymerized acrylic resin were prepared and randomly divided into eight groups (n = 10): one intact group (control) and seven repaired groups. One group was repaired with autopolymerized resin while the other six groups were repaired using autopolymerized resin reinforced with 2 wt% or 5 wt% glass fiber, zirconia, or nano-zirconia particles. A three-point bending test was used to measure the transverse strength. The results were analyzed using SPSS and repeated measure ANOVA and post hoc least significance (LSD) test (P ≤ 0.05). Results. Among repaired groups it was found that autopolymerized resin reinforced with 2 or 5 wt% nano-zirconia showed the highest transverse strength (P ≤ 0.05). Repairs with autopolymerized acrylic resin reinforced with 5 wt% zirconia showed the lowest transverse strength value. There was no significant difference between the groups repaired with repair resin without reinforcement, 2 wt% zirconia, and glass fiber reinforced resin. Conclusion. Reinforcing of repair material with nano-zirconia may significantly improve the transverse strength of some fractured denture base polymers.

  15. The Reinforcement Effect of Nano-Zirconia on the Transverse Strength of Repaired Acrylic Denture Base

    PubMed Central

    ArRejaie, Aws S.; Abdel-Halim, Mohamed Saber; Rahoma, Ahmed

    2016-01-01

    Objective. The aim of this study was to evaluate the effect of incorporation of glass fiber, zirconia, and nano-zirconia on the transverse strength of repaired denture base. Materials and Methods. Eighty specimens of heat polymerized acrylic resin were prepared and randomly divided into eight groups (n = 10): one intact group (control) and seven repaired groups. One group was repaired with autopolymerized resin while the other six groups were repaired using autopolymerized resin reinforced with 2 wt% or 5 wt% glass fiber, zirconia, or nano-zirconia particles. A three-point bending test was used to measure the transverse strength. The results were analyzed using SPSS and repeated measure ANOVA and post hoc least significance (LSD) test (P ≤ 0.05). Results. Among repaired groups it was found that autopolymerized resin reinforced with 2 or 5 wt% nano-zirconia showed the highest transverse strength (P ≤ 0.05). Repairs with autopolymerized acrylic resin reinforced with 5 wt% zirconia showed the lowest transverse strength value. There was no significant difference between the groups repaired with repair resin without reinforcement, 2 wt% zirconia, and glass fiber reinforced resin. Conclusion. Reinforcing of repair material with nano-zirconia may significantly improve the transverse strength of some fractured denture base polymers. PMID:27366150

  16. The Reinforcement Effect of Nano-Zirconia on the Transverse Strength of Repaired Acrylic Denture Base.

    PubMed

    Gad, Mohammed; ArRejaie, Aws S; Abdel-Halim, Mohamed Saber; Rahoma, Ahmed

    2016-01-01

    Objective. The aim of this study was to evaluate the effect of incorporation of glass fiber, zirconia, and nano-zirconia on the transverse strength of repaired denture base. Materials and Methods. Eighty specimens of heat polymerized acrylic resin were prepared and randomly divided into eight groups (n = 10): one intact group (control) and seven repaired groups. One group was repaired with autopolymerized resin while the other six groups were repaired using autopolymerized resin reinforced with 2 wt% or 5 wt% glass fiber, zirconia, or nano-zirconia particles. A three-point bending test was used to measure the transverse strength. The results were analyzed using SPSS and repeated measure ANOVA and post hoc least significance (LSD) test (P ≤ 0.05). Results. Among repaired groups it was found that autopolymerized resin reinforced with 2 or 5 wt% nano-zirconia showed the highest transverse strength (P ≤ 0.05). Repairs with autopolymerized acrylic resin reinforced with 5 wt% zirconia showed the lowest transverse strength value. There was no significant difference between the groups repaired with repair resin without reinforcement, 2 wt% zirconia, and glass fiber reinforced resin. Conclusion. Reinforcing of repair material with nano-zirconia may significantly improve the transverse strength of some fractured denture base polymers. PMID:27366150

  17. Study on torpedo fuze signal denoising method based on WPT

    NASA Astrophysics Data System (ADS)

    Zhao, Jun; Sun, Changcun; Zhang, Tao; Ren, Zhiliang

    2013-07-01

    Torpedo fuze signal denoising is an important action to ensure reliable operation of fuze. Based on the good characteristics of wavelet packet transform (WPT) in signal denoising, the paper used wavelet packet transform to denoise the fuze signal under a complex background interference, and a simulation of the denoising results with Matlab is performed. Simulation result shows that the WPT denoising method can effectively eliminate background noise exist in torpedo fuze target signal with higher precision and less distortion, leading to advance the reliability of torpedo fuze operation.

  18. Manufacturing of agarose-based chromatographic adsorbents--effect of ionic strength and cooling conditions on particle structure and mechanical strength.

    PubMed

    Ioannidis, Nicolas; Bowen, James; Pacek, Andrzej; Zhang, Zhibing

    2012-02-01

    The effect of ionic strength of agarose solution and quenching temperature of the emulsion on the structure and mechanical strength of agarose-based chromatographic adsorbents was investigated. Solutions of agarose containing different amounts of NaCl were emulsified at elevated temperature in mineral oil using a high-shear mixer. The hot emulsion was quenched at different temperatures leading to the gelation of agarose and formation of soft particles. Analysis of Atomic Force Microscopy (AFM) images of particle surfaces shows that pore size of particles increases with ionic strength and/or high quenching temperature. Additionally it has been found that the compressive strength of particles measured by micromanipulation also increases with ionic strength of the emulsion and/or high quenching temperature but these two parameters have no significant effect on the resulting particle size and particle size distribution. Results from both characterization methods were compared with Sepharose 4B, a commercial agarose-based adsorbent. This is the first report examining the effect of ionic strength and cooling conditions on the microstructure of micron-sized agarose beads for bioseparation.

  19. Electrocardiogram signal denoising based on a new improved wavelet thresholding

    NASA Astrophysics Data System (ADS)

    Han, Guoqiang; Xu, Zhijun

    2016-08-01

    Good quality electrocardiogram (ECG) is utilized by physicians for the interpretation and identification of physiological and pathological phenomena. In general, ECG signals may mix various noises such as baseline wander, power line interference, and electromagnetic interference in gathering and recording process. As ECG signals are non-stationary physiological signals, wavelet transform is investigated to be an effective tool to discard noises from corrupted signals. A new compromising threshold function called sigmoid function-based thresholding scheme is adopted in processing ECG signals. Compared with other methods such as hard/soft thresholding or other existing thresholding functions, the new algorithm has many advantages in the noise reduction of ECG signals. It perfectly overcomes the discontinuity at ±T of hard thresholding and reduces the fixed deviation of soft thresholding. The improved wavelet thresholding denoising can be proved to be more efficient than existing algorithms in ECG signal denoising. The signal to noise ratio, mean square error, and percent root mean square difference are calculated to verify the denoising performance as quantitative tools. The experimental results reveal that the waves including P, Q, R, and S waves of ECG signals after denoising coincide with the original ECG signals by employing the new proposed method.

  20. Electrocardiogram signal denoising based on a new improved wavelet thresholding.

    PubMed

    Han, Guoqiang; Xu, Zhijun

    2016-08-01

    Good quality electrocardiogram (ECG) is utilized by physicians for the interpretation and identification of physiological and pathological phenomena. In general, ECG signals may mix various noises such as baseline wander, power line interference, and electromagnetic interference in gathering and recording process. As ECG signals are non-stationary physiological signals, wavelet transform is investigated to be an effective tool to discard noises from corrupted signals. A new compromising threshold function called sigmoid function-based thresholding scheme is adopted in processing ECG signals. Compared with other methods such as hard/soft thresholding or other existing thresholding functions, the new algorithm has many advantages in the noise reduction of ECG signals. It perfectly overcomes the discontinuity at ±T of hard thresholding and reduces the fixed deviation of soft thresholding. The improved wavelet thresholding denoising can be proved to be more efficient than existing algorithms in ECG signal denoising. The signal to noise ratio, mean square error, and percent root mean square difference are calculated to verify the denoising performance as quantitative tools. The experimental results reveal that the waves including P, Q, R, and S waves of ECG signals after denoising coincide with the original ECG signals by employing the new proposed method. PMID:27587134

  1. Acceptability and Feasibility Results of a Strength-Based Skills Training Program for Dementia Caregiving Dyads

    ERIC Educational Resources Information Center

    Judge, Katherine S.; Yarry, Sarah J.; Orsulic-Jeras, Silvia

    2010-01-01

    Purpose: The current article provides an in-depth description of a dyadic intervention for individuals with dementia and their family caregivers. Using a strength-based approach, caregiving dyads received skills training across 5 key areas: (a) education regarding dementia and memory loss, (b) effective communication, (c) managing memory loss, (d)…

  2. Balancing the Imbalance: Integrating a Strength-Based Approach with a Medical Model

    ERIC Educational Resources Information Center

    Foltz, Robert

    2006-01-01

    There are major differences in perspective between the traditional medical model of treatment for troubled children and more recent strength-based approaches. This is particularly evident when widespread use of psychoactive drugs becomes a substitute for interpersonal therapeutic interventions. Drugs and relationships both impact the brain, but in…

  3. A Strengths-Based Approach to Promoting Prosocial Behavior among African American and Latino Students

    ERIC Educational Resources Information Center

    Day-Vines, Norma L.; Terriquez, Veronica

    2008-01-01

    This article presents an overview of a strengths-based school discipline initiative that was developed in response to the high suspension and expulsion rates of African American and Latino male students at a racially diverse, urban high school in California. A school task force made up of adult and youth stakeholders devised a series of…

  4. Counseling Older Adults with HIV/AIDS: A Strength-Based Model of Treatment.

    ERIC Educational Resources Information Center

    Orsulic-Jeras, Silvia; Shepherd, J. Brad; Britton, Paula J.

    2003-01-01

    This article outlines a strength-based assessment and treatment model applicable for the mental health counseling of those aging with HIV. By focusing on the specific areas of life where clients are functioning effectively, this model works to decrease attention to pathology and stigma and, subsequently, works to empower clients to concentrate on…

  5. Evaluation of a sugar based edible adhesive utilizing a tensile strength tester

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new method to evaluate adhesives has been developed and utilized to formulate a recently patented adhesive based on sugar and citric acid. Factors affecting adhesive performance were uncovered, such as reduced strength due to improper heating time, and an optimal curing temperature of 60oC was ac...

  6. Towards a Strength-Based Juvenile Correctional Facility: Sustainability and Effects of an Institutional Transformation

    ERIC Educational Resources Information Center

    Barton, William H.; Mackin, Juliette R.

    2012-01-01

    In 2006, the administration of a state-run, secure juvenile correctional facility initiated an attempt to transform its institutional culture using a strength-based approach to assessment and case planning. This resulted in a rapid improvement in institutional climate. The current study revisits this setting several years later to see if those…

  7. Using Strength-Based Approaches to Explore Pretreatment Change in Men Who Abuse Their Partners

    ERIC Educational Resources Information Center

    Curwood, Susan Eckerle; DeGeer, Ian; Hymmen, Peter; Lehmann, Peter

    2011-01-01

    Group work with men who batter has traditionally consisted predominantly of psychoeducational programs that ignore concepts such as self-determination, goal setting, and positive engagement with men. More recently, this paradigm has begun to shift to include cognitive approaches and the utilization of strength-based strategies. The present sample…

  8. The Consequences of Differentiation in Episodic Memory: Similarity and the Strength Based Mirror Effect

    ERIC Educational Resources Information Center

    Criss, Amy H.

    2006-01-01

    When items on one list receive more encoding than items on another list, the improvement in performance usually manifests as an increase in the hit rate and a decrease in the false alarm rate (FAR). A common account of this strength based mirror effect is that participants adopt a more strict criterion following a strongly than weakly encoded list…

  9. Solution-Focused Therapy: Strength-Based Counseling for Children with Social Phobia

    ERIC Educational Resources Information Center

    George, Cindy M.

    2008-01-01

    Solution-focused therapy is proposed as an effective strength-based model for children with social phobia. Social phobia is described along with the etiology and prevailing treatment approaches. A case illustration demonstrates the application of solution-focused therapy with a child who experienced social phobia. Implications for counseling and…

  10. Collaborative Strengths-Based Brief Therapy with Self-Injuring Adolescents and Their Families

    ERIC Educational Resources Information Center

    Selekman, Matthew D.

    2010-01-01

    This article presents a family competency-based treatment approach that capitalizes on the strengths and resources of self-injuring adolescents and their families. Throughout the article, the author provides therapeutic tools and strategies that he has found effective in his clinical practice of working with self-injuring youth and their families…

  11. Strength-Based RTI: Conceptualizing a Multi-Tiered System for Developing Gifted Potential

    ERIC Educational Resources Information Center

    Bianco, Margarita

    2010-01-01

    This article explores the possibilities of a strength-based Response to Intervention (RTI) model for developing and identifying gifted potential. Although much has been written about the promises and challenges of RTI in recent years, the utility of RTI for meeting the needs of gifted learners has not been fully explored. This article seeks to…

  12. The Influence of Strengths-Based Development on Leadership Practices among Undergraduate College Students

    ERIC Educational Resources Information Center

    Lehnert, Alina Black

    2009-01-01

    This study explored the influence of strengths-based development on leadership practices among undergraduate college students while controlling for gender, years of leadership experience, and number of completed leadership courses using a quasi-experimental approach with a randomized control-group pretest-posttest research design. The sample…

  13. A Salutogenic, Strengths-Based Approach as a Theory to Guide HPE Curriculum Change

    ERIC Educational Resources Information Center

    McCuaig, Louise; Quennerstedt, Mikael; Macdonald, Doune

    2013-01-01

    The draft Australian Health and Physical Education (HPE) curriculum (Australian Curriculum, Assessment and Reporting Authority [ACARA], 2012c) takes a strengths-based approach that emphasizes questions such as "What keeps me healthy and active?" rather than "What risks, diseases and behaviours should I learn to avoid?". This…

  14. Strength-Based Factors for Successful Adaptation to an Early College High School Environment

    ERIC Educational Resources Information Center

    Abernethy, Catherine

    2010-01-01

    In an early college high school setting, students are subject to varying academic, social and contextual demands of a higher educational environment. In a strength-based study of 136 diverse early college high school students, this research explored the relationship of internal and external developmental assets to adaptive functioning of…

  15. The Strength-Based Counseling Model: A Paradigm Shift in Psychology

    ERIC Educational Resources Information Center

    Smith, Elsie J.

    2006-01-01

    Sometimes, it is difficult for a profession to move forward because its members interpret emerging conceptual models from the perspective of old frameworks. Each of the five reactants in this issue of "The Counseling Psychologist" interpreted the strength-based counseling model within their own self-adopted framework--Adlerian psychology, role…

  16. A Strengths-Based Approach to Supervised Visitation in Child Welfare

    ERIC Educational Resources Information Center

    Smith, Gabriel Tobin; Shapiro, Valerie B.; Sperry, Rachel Wagner; LeBuffe, Paul A.

    2014-01-01

    This article describes a strengths-based approach to supervised visitation within the child welfare system of the United States. Supervised visitation gives parents accused of abuse or neglect the opportunity to spend time with children temporarily removed from their care. Although supervised visitation has the potential to be a tool for promoting…

  17. Promoting Multicultural Personality Development: A Strengths-Based, Positive Psychology Worldview for Schools

    ERIC Educational Resources Information Center

    Ponterotto, Joseph G.; Mendelowitz, David E.; Collabolletta, Ernest A.

    2008-01-01

    This article extends the relevance of multicultural development to the Strengths-Based School Counseling (SBSC; Galassi & Akos, 2007) perspective. A relatively new construct for school counselors, the "multicultural personality" (MP), is introduced and defined. The MP is conceptualized as a cluster of narrow personality traits that can be subsumed…

  18. SIG-VISA: Signal-based Vertically Integrated Seismic Monitoring

    NASA Astrophysics Data System (ADS)

    Moore, D.; Mayeda, K. M.; Myers, S. C.; Russell, S.

    2013-12-01

    Traditional seismic monitoring systems rely on discrete detections produced by station processing software; however, while such detections may constitute a useful summary of station activity, they discard large amounts of information present in the original recorded signal. We present SIG-VISA (Signal-based Vertically Integrated Seismic Analysis), a system for seismic monitoring through Bayesian inference on seismic signals. By directly modeling the recorded signal, our approach incorporates additional information unavailable to detection-based methods, enabling higher sensitivity and more accurate localization using techniques such as waveform matching. SIG-VISA's Bayesian forward model of seismic signal envelopes includes physically-derived models of travel times and source characteristics as well as Gaussian process (kriging) statistical models of signal properties that combine interpolation of historical data with extrapolation of learned physical trends. Applying Bayesian inference, we evaluate the model on earthquakes as well as the 2009 DPRK test event, demonstrating a waveform matching effect as part of the probabilistic inference, along with results on event localization and sensitivity. In particular, we demonstrate increased sensitivity from signal-based modeling, in which the SIGVISA signal model finds statistical evidence for arrivals even at stations for which the IMS station processing failed to register any detection.

  19. Effect of root canal filling techniques on the bond strength of epoxy resin-based sealers.

    PubMed

    Rached-Júnior, Fuad Jacob Abi; Souza, Angélica Moreira; Macedo, Luciana Martins Domingues; Raucci-Neto, Walter; Baratto-Filho, Flares; Silva, Bruno Marques; Silva-Sousa, Yara Teresinha Corrêa

    2016-01-01

    The aim of this study was to evaluate the effects of different root canal filling techniques on the bond strength of epoxy resin-based sealers. Sixty single-rooted canines were prepared using ProTaper (F5) and divided into the following groups based on the root filling technique: Lateral Compaction (LC), Single Cone (SC), and Tagger Hybrid Technique (THT). The following subgroups (n = 10) were also created based on sealer material used: AH Plus and Sealer 26. Two-millimeter-thick slices were cut from all the root thirds and subjected to push-out test. Data (MPa) was analyzed using ANOVA and Tukey's test (α = 0.05). The push-out values were significantly affected by the sealer, filling technique, and root third (p < 0.05). AH Plus (1.37 ± 1.04) exhibited higher values than Sealer 26 (0.92 ± 0.51), while LC (1.80 ± 0.98) showed greater bond strength than THT (1.16 ± 0.50) and SC (0.92 ± 0.25). The cervical (1.45 ± 1.14) third exhibited higher bond strength, followed by the middle (1.20 ± 0.72) and apical (0.78 ± 0.33) thirds. AH Plus/LC (2.26 ± 1.15) exhibited the highest bond strength values, followed by AH Plus/THT (1.32 ± 0.61), Sealer 26/LC (1.34 ± 0.42), and Sealer 26/THT (1.00 ± 0.27). The lowest values were obtained with AH Plus/SC and Sealer 26/SC. Thus, it can be concluded that the filling technique affects the bond strength of sealers. LC was associated with higher bond strength between the material and intra-radicular dentine than THT and SC techniques. PMID:26910020

  20. Conditional Density-based Analysis of T cell Signaling in Single Cell Data

    PubMed Central

    Krishnaswamy, Smita; Spitzer, Matthew H.; Mingueneau, Michael; Bendall, Sean C; Litvin, Oren; Stone, Erica; Pe’er, Dana; Nolan, Garry P

    2015-01-01

    Cellular circuits sense the environment, process signals, and compute decisions using networks of interacting proteins. To model such a system, the abundance of each activated protein species can be described as a stochastic function of the abundance of other proteins. High-dimensional single-cell technologies, like mass cytometry, offer an opportunity to characterize signaling circuit-wide. However, the challenge of developing and applying computational approaches to interpret such complex data remains. Here, we developed computational methods, based on established statistical concepts, to characterize signaling network relationships by quantifying the strengths of network edges and deriving signaling response functions. In comparing signaling between naïve and antigen-exposed CD4+ T-lymphocytes, we find that although these two cell subtypes had similarly-wired networks, naïve cells transmitted more information along a key signaling cascade than did antigen-exposed cells. We validated our characterization on mice lacking the extracellular-regulated MAP kinase (ERK2), which showed stronger influence of pERK on pS6 (phosphorylated-ribosomal protein S6), in naïve cells compared to antigen-exposed cells, as predicted. We demonstrate that by using cell-to-cell variation inherent in single cell data, we can algorithmically derive response functions underlying molecular circuits and drive the understanding of how cells process signals. PMID:25342659

  1. Linear Frequency Estimation Technique for Reducing Frequency Based Signals

    PubMed Central

    Woodbridge, Jonathan; Bui, Alex; Sarrafzadeh, Majid

    2016-01-01

    This paper presents a linear frequency estimation (LFE) technique for data reduction of frequency-based signals. LFE converts a signal to the frequency domain by utilizing the Fourier transform and estimates both the real and imaginary parts with a series of vectors much smaller than the original signal size. The estimation is accomplished by selecting optimal points from the frequency domain and interpolating data between these points with a first order approximation. The difficulty of such a problem lies in determining which points are most significant. LFE is unique in the fact that it is generic to a wide variety of frequency-based signals such as electromyography (EMG), voice, and electrocardiography (ECG). The only requirement is that spectral coefficients are spatially correlated. This paper presents the algorithm and results from both EMG and voice data. We complete the paper with a description of how this method can be applied to pattern types of recognition, signal indexing, and compression.

  2. Effect of Intermediate Agents and Preheated Composites on Repair Bond Strength of Silorane-Based Composites

    PubMed Central

    Shafiei, Fereshteh; Daryadar, Marzieh

    2015-01-01

    Objectives: Repairing composite restorations is a challenging procedure especially when two different types of composites are used. This study aimed to compare the repair strength of silorane-based composite (SC) (Filtek P90) with that of preheated SC, methacrylate composite (MC)(Z250), flowable MC (Filtek Supreme Plus) and different adhesive/composite combinations. Materials and Methods: Eighty-four SC specimens were fabricated and randomly divided into seven groups (G). In the control group (G7), SC was bonded immediately to SC. The other specimens were water-aged for two months and were then roughened, etched and repaired with the following materials: G1) Silorane Adhesive Bond (SAB)/SC; G2) Preheated SC; G3) SAB/MC; G4) Adper Single Bond (SB)/MC; G5) Flowable MC/MC; G6) Preheated MC. After water storage and thermocycling, the repaired specimens were subjected to shear bond strength testing. The data were analyzed using ANOVA and Tukey’s test. Results: Preheated SC and MC, flowable MC and SAB/SC resulted in bond strength comparable to that of the control group. Preheated SC showed significantly higher bond strength when compared to SAB/MC (P=0.04) and SB/MC (P<0.001). Bond strength of SB/MC was significantly lower than that of the other groups (P<0.05), except for SAB/SC and SAB/MC. Conclusion: All repairing materials except for SB/MC resulted in bond strength values comparable to that of the control group. Repair with preheated SC yielded the highest bond strength. PMID:27148378

  3. The Effect of Gap Angle on Tensile Strength of Preceramic Base Metal Solder Joints

    PubMed Central

    Fattahi, Farnaz; Hashemi Ardakani, Zahra; Hashemi Ardakani, Maryam

    2015-01-01

    Statement of the Problem Soldering is a process commonly used in fabricating dental prosthesis. Since most soldered prosthesis fail at the solder joints; the joint strength is of utmost importance. Purpose The purpose of this study was to evaluate the effect of gap angle on the tensile strength of base metal solder joints. Materials and Method A total number of 40 Ni-Cr samples were fabricated according to ADA/ISO 9693 specifications for tensile test. Samples were cut at the midpoint of the bar, and were placed at the considered angles by employing an explicitly designed device. They were divided into 4 groups regarding the gap angle; Group C (control group) with parallel gap on steady distance of 0.2mm, Group 1: 10°, Group 2: 20°, and Group3: 30° gap angles. When soldered, the specimens were all tested for tensile strength using a universal testing machine at a cross-head speed of 0.5 mm/min with a preload of 10N. Kruskal-Wallis H test was used to compare tensile strength among the groups (p< 0.05). Results The mean tensile strength values obtained from the study groups were respectively 307.84, 391.50, 365.18, and 368.86 MPa. The tensile strength was not statistically different among the four groups in general (p≤ 0.490). Conclusion Making the gap angular at the solder joints and the subsequent unsteady increase of the gap distance would not change the tensile strength of the joint. PMID:26636118

  4. Effect of Aging on Bond Strength of Two Soft Lining Materials to a Denture Base Polymer.

    PubMed

    Salloum, Alaa'a M

    2014-12-01

    The purpose of this study was evaluation the effect of immersion in distilled water and inorganic artificial saliva on the shear bond strength of a heat-polymerized and an auto-polymerized silicone-based denture lining materials. The denture liners investigated were Molloplast-B (heat-polymerized), and Mollosil plus (auto-polymerized). The soft liner specimens were 10 × 10 × 2.5 mm and were processed between two poly(methylmethacrylate) plates. Thirty shear specimens for each type of test lining material were prepared. Specimens were divided equally into three groups for each test lining material: first group, specimens were tested after 48 h of preparation without immersion; second group, specimens were tested following immersion in distilled water at 37 °C for 12 months; and third group, specimens were tested following immersion in inorganic artificial saliva at 37 °C for 12 months. Shear bond strength was measured using an universal testing machine at a crosshead speed of 40 mm/min and failure mode (adhesive, cohesive and mixed) after debonding was assessed. Data were statistically analyzed with one-way analysis of variance (ANOVA) (α = 0.05). ANOVA was followed by Bonferroni post hoc tests for pairwise comparisons. A significant difference in shear bond strength was detected between Molloplast-B and Mollosil plus following immersion in distilled water and artificial saliva. Molloplast-B demonstrated considerably higher shear strength than Mollosil plus after immersion. Shear strengths of the lining materials investigated reduced significantly after immersion in both solutions. Visual examination after separation revealed that the soft materials tested exhibited mostly adhesive failure. The effect of immersion in distilled water and inorganic artificial saliva on bond strength of test lining materials was perceivable; however, both of them had acceptable bond strength and might be proper for long-term use. PMID:26199507

  5. Etching process for improving the strength of a laser-machined silicon-based ceramic article

    DOEpatents

    Copley, Stephen M.; Tao, Hongyi; Todd-Copley, Judith A.

    1991-01-01

    A process for improving the strength of laser-machined articles formed of a silicon-based ceramic material such as silicon nitride, in which the laser-machined surface is immersed in an etching solution of hydrofluoric acid and nitric acid for a duration sufficient to remove substantially all of a silicon film residue on the surface but insufficient to allow the solution to unduly attack the grain boundaries of the underlying silicon nitride substrate. This effectively removes the silicon film as a source of cracks that otherwise could propagate downwardly into the silicon nitride substrate and significantly reduce its strength.

  6. Etching process for improving the strength of a laser-machined silicon-based ceramic article

    DOEpatents

    Copley, S.M.; Tao, H.; Todd-Copley, J.A.

    1991-06-11

    A process is disclosed for improving the strength of laser-machined articles formed of a silicon-based ceramic material such as silicon nitride, in which the laser-machined surface is immersed in an etching solution of hydrofluoric acid and nitric acid for a duration sufficient to remove substantially all of a silicon film residue on the surface but insufficient to allow the solution to unduly attack the grain boundaries of the underlying silicon nitride substrate. This effectively removes the silicon film as a source of cracks that otherwise could propagate downwardly into the silicon nitride substrate and significantly reduce its strength. 1 figure.

  7. Orthodontic Molar Brackets: The Effect of Three Different Base Designs on Shear Bond Strength

    PubMed Central

    Hudson, Athol P.; Grobler, Sias R.; Harris, Angela M. P.

    2011-01-01

    The purpose of the study was to assess the relative base designs of three different maxillary molar stainless steel brackets with reference to the shear bond strength of three different adhesive resins. The molar brackets used were Victory series (3M Unitek), Upper Molar (GAC) and Optimesh XRT (Ormco). The adhesives used were Transbond XT (3M Unitek), Enlight (Ormco) and Sure Ortho Light Bond (Sure Orthodontics). The human enamel specimens (144) were randomly divided into nine groups and each group (n=16) was allocated to a bracket/adhesive combination. The contact surface of each of the bracket bases was measured three dimensionally using a reflex microscope. The base designs were also subjected to further microscopic investigations. The brackets were bonded to the enamel, temperature cycled and the shear bond strength was measured. The size and design of each of the brackets was different. The base size, surface treatment, mesh strand diameter and aperture size of the bracket base mesh have a significant effect on the shear bond strength at the bracket/adhesive interface. The shear bond strengths of all three Ormco bracket/adhesive resin combinations (5.8-6.8 MPa) were significantly lower (p<0.05; Kruskal-Wallis) than the other six bracket/adhesive combinations (9.4-12.1 MPa). The different adhesive types (3 types) could not be mainly responsible for the low shear bond values found for the Ormco bracket. The 3M Unitek combination of the Victory series bracket and Transbond XT adhesive proved to have a high shear bond strength without enamel damage. PMID:23675217

  8. Interfacial shear bond strength between different base metal alloys and five low fusing feldspathic ceramic systems.

    PubMed

    Sipahi, Cumhur; Ozcan, Mutlu

    2012-01-01

    This study compared the bond strength between metal alloys and 5 ceramic systems. Ceramic systems (Vita VMK68, Ivoclar IPSd. SIGN, Ceramco II, Matchmaker and Finesse) were fired onto either Ni-Cr or Co-Cr base metal alloy. Metal-ceramic interfaces were subjected to shear loading until failure. The ceramic type significantly affected the bond strength results (p<0.05). For Ni-Cr alloy, the results ranged between 15.4-25.3 MPa and for Co-Cr alloy between 13.3-19.0 MPa. The highest mean bond strength value was obtained with the combination of Ni-Cr alloy-Ceramco II (25.3 MPa), the lowest bond strength was received from the combination of Co-Cr alloy-Ivoclar IPS d.SIGN ceramic (13.3 MPa). Adhesive failures between metal and ceramic were significantly more frequent with Ni-Cr alloy (31 out of 50) than with Co-Cr (20 out of 50) (p<0.05). Ceramco II presented the highest bond strength with both Ni-Cr and Co-Cr being significantly different from one another.

  9. Damage formation, fatigue behavior and strength properties of ZrO2-based ceramics

    NASA Astrophysics Data System (ADS)

    Kozulin, A. A.; Narikovich, A. S.; Kulkov, S. N.; Leitsin, V. N.; Kulkov, S. S.

    2016-08-01

    It is suggested that a non-destructive testing technique using a three-dimensional X-ray tomography be applied to detecting internal structural defects and monitoring damage formation in a ceramic composite structure subjected to a bending load. Three-point bending tests are used to investigate the fatigue behavior and mechanical and physical properties of medical-grade ZrO2-based ceramics. The bending strength and flexural modulus are derived under static conditions at a loading rate of 2 mm/min. The fatigue strength and fatigue limit under dynamic loading are investigated at a frequency of 10 Hz in three stress ranges: 0.91-0.98, 0.8-0.83, and 0.73-0.77 MPa of the static bending strength. The average values of the bending strength and flexural modulus of sintered specimens are 43 MPa and 22 GPa, respectively. The mechanical properties of the ceramics are found to be similar to those of bone tissues. The testing results lead us to conclude that the fatigue limit obtained from 105 stress cycles is in the range 33-34 MPa, i.e. it accounts for about 75% of the static bending strength for the test material.

  10. COMPARISON OF QUANTITATIVE COMPUTED TOMOGRAPHY-BASED MEASURES IN PREDICTING VERTEBRAL COMPRESSIVE STRENGTH

    PubMed Central

    Buckley, Jenni M.; Loo, Kenneth; Motherway, Julie

    2007-01-01

    Patient-specific measures derived from quantitative computed tomography (QCT) scans are currently being developed as a clinical tool for vertebral strength prediction. QCT-based measurement techniques vary greatly in structural complexity and generally fall into one of three categories: 1) bone mineral density (BMD), 2) “mechanics of solids” (MOS) models, such as minimum axial rigidity (the product of axial stiffness and vertebral height), or 3) three dimensional finite element (FE) models. There is no clear consensus as to the relative performance of these measures due to differences in experimental protocols, sample sizes and demographics, and outcome metrics. The goal of this study was to directly compare the performance of QCT-based assessment techniques of varying degrees of structural sophistication in predicting experimental vertebral compressive strength. Eighty-one human thoracic vertebrae (T6 – T10) from 44 donors cadavers (F = 32, M = 12; 85 + 8 y.o., max = 97 y.o., min = 54 y.o.) were QCT scanned and destructively tested in uniaxial compression. The QCT scans were processed to generate FE models and various BMD and MOS measures, including trabecular bone mineral density (tBMD), integral bone mineral density (iBMD), and axial rigidity. Bone mineral density was weakly to moderately predictive of compressive strength (R2 = 0.16 and 0.62 for tBMD and iBMD, respectively). Ex vivo vertebral strength was strongly correlated with both axial rigidity (R2 = 0.81) and FE strength measurements (R2 = 0.80), and the predictive capabilities of these two metrics were statistically equivalent (p > 0.05 for differences between FE and axial rigidity). The results of this study indicate that non-invasive predictive measures of vertebral strength should include some level of structural sophistication, specifically, gross geometric and material property distribution information. However, for uniaxial compression of isolated vertebrae, which is the current biomechanical

  11. Design of transient light signal simulator based on FPGA

    NASA Astrophysics Data System (ADS)

    Kang, Jing; Chen, Rong-li; Wang, Hong

    2014-11-01

    A design scheme of transient light signal simulator based on Field Programmable gate Array (FPGA) was proposed in this paper. Based on the characteristics of transient light signals and measured feature points of optical intensity signals, a fitted curve was created in MATLAB. And then the wave data was stored in a programmed memory chip AT29C1024 by using SUPERPRO programmer. The control logic was realized inside one EP3C16 FPGA chip. Data readout, data stream cache and a constant current buck regulator for powering high-brightness LEDs were all controlled by FPGA. A 12-Bit multiplying CMOS digital-to-analog converter (DAC) DAC7545 and an amplifier OPA277 were used to convert digital signals to voltage signals. A voltage-controlled current source constituted by a NPN transistor and an operational amplifier controlled LED array diming to achieve simulation of transient light signal. LM3405A, 1A Constant Current Buck Regulator for Powering LEDs, was used to simulate strong background signal in space. Experimental results showed that the scheme as a transient light signal simulator can satisfy the requests of the design stably.

  12. Lower limb strength training in children with cerebral palsy – a randomized controlled trial protocol for functional strength training based on progressive resistance exercise principles

    PubMed Central

    Scholtes, Vanessa A; Dallmeijer, Annet J; Rameckers, Eugene A; Verschuren, Olaf; Tempelaars, Els; Hensen, Maartje; Becher, Jules G

    2008-01-01

    Background Until recently, strength training in children with cerebral palsy (CP) was considered to be inappropriate, because it could lead to increased spasticity or abnormal movement patterns. However, the results of recent studies suggest that progressive strength training can lead to increased strength and improved function, but low methodological quality and incomplete reporting on the training protocols hampers adequate interpretation of the results. This paper describes the design and training protocol of a randomized controlled trial to assess the effects of a school-based progressive functional strength training program for children with CP. Methods/Results Fifty-one children with Gross Motor Function Classification Systems levels I to III, aged of 6 to 13 years, were recruited. Using stratified randomization, each child was assigned to an intervention group (strength training) or a control group (usual care). The strength training was given in groups of 4–5 children, 3 times a week, for a period of 12 weeks. Each training session focussed on four exercises out of a 5-exercise circuit. The training load was gradually increased based on the child's maximum level of strength, as determined by the 8 Repetition Maximum (8 RM). To evaluate the effectiveness of the training, all children were evaluated before, during, directly after, and 6 weeks after the intervention period. Primary outcomes in this study were gross motor function (measured with the Gross Motor Function Measure and functional muscle strength tests) and walking ability (measured with the 10-meter, the 1-minute and the timed stair test). Secondary outcomes were lower limb muscle strength (measured with a 6 RM test, isometric strength tests, and a sprint capacity test), mobility (measured with a mobility questionnaire), and sport activities (measured with the Children's Assessment of Participation and Enjoyment). Spasticity and range of motion were assessed to evaluate any adverse events

  13. Determination of the electric field strength of filamentary DBDs by CARS-based four-wave mixing

    NASA Astrophysics Data System (ADS)

    Böhm, P.; Kettlitz, M.; Brandenburg, R.; Höft, H.; Czarnetzki, U.

    2016-10-01

    It is demonstrated that a four-wave mixing technique based on coherent anti-Stokes Raman spectroscopy (CARS) can determine the electric field strength of a pulsed-driven filamentary dielectric barrier discharge (DBD) of 1 mm gap, using hydrogen as a tracer medium in nitrogen at atmospheric pressure. The measurements are presented for a hydrogen admixture of 10%, but even 5% H2 admixture delivers sufficient infrared signals. The lasers do not affect the discharge by photoionization or by other radiation-induced processes. The absolute values of the electric field strength can be determined by the calibration of the CARS setup with high voltage amplitudes below the ignition threshold of the arrangement. This procedure also enables the determination of the applied breakdown voltage. The alteration of the electric field is observed during the internal polarity reversal and the breakdown process. One advantage of the CARS technique over emission-based methods is that it can be used independently of emission, e.g. in the pre-phase and in between two consecutive discharges, where no emission occurs at all.

  14. Incoherent signal source resolution based on coherent aperture synthesis

    NASA Astrophysics Data System (ADS)

    Zverev, V. A.

    2016-05-01

    A technique is proposed for resolving two incoherent signal sources of the same frequency and significantly different intensities with similar angular coordinates. The technique is based on aperture synthesis of a receiving array, first, by the signal of higher-power source and the estimate of its angular coordinate with subsequent subtraction of the signal spectrum from the angular spectrum of the received field. This makes it possible to achieve aperture synthesis and estimate the angle of arrival of a higher-power signal. Thus, the technique is of interest not only for synthesized apertures, but also for arrays with a filled aperture, since it eliminates the restrictions imposed by the presence of lateral lobes of the array response. Our mathematical simulation data demonstrate the efficiency of this technique in the detection and location of weak signals against the background of high-power noise sources even at their close angular positions.

  15. Wavelet-based ground vehicle recognition using acoustic signals

    NASA Astrophysics Data System (ADS)

    Choe, Howard C.; Karlsen, Robert E.; Gerhart, Grant R.; Meitzler, Thomas J.

    1996-03-01

    We present, in this paper, a wavelet-based acoustic signal analysis to remotely recognize military vehicles using their sound intercepted by acoustic sensors. Since expedited signal recognition is imperative in many military and industrial situations, we developed an algorithm that provides an automated, fast signal recognition once implemented in a real-time hardware system. This algorithm consists of wavelet preprocessing, feature extraction and compact signal representation, and a simple but effective statistical pattern matching. The current status of the algorithm does not require any training. The training is replaced by human selection of reference signals (e.g., squeak or engine exhaust sound) distinctive to each individual vehicle based on human perception. This allows a fast archiving of any new vehicle type in the database once the signal is collected. The wavelet preprocessing provides time-frequency multiresolution analysis using discrete wavelet transform (DWT). Within each resolution level, feature vectors are generated from statistical parameters and energy content of the wavelet coefficients. After applying our algorithm on the intercepted acoustic signals, the resultant feature vectors are compared with the reference vehicle feature vectors in the database using statistical pattern matching to determine the type of vehicle from where the signal originated. Certainly, statistical pattern matching can be replaced by an artificial neural network (ANN); however, the ANN would require training data sets and time to train the net. Unfortunately, this is not always possible for many real world situations, especially collecting data sets from unfriendly ground vehicles to train the ANN. Our methodology using wavelet preprocessing and statistical pattern matching provides robust acoustic signal recognition. We also present an example of vehicle recognition using acoustic signals collected from two different military ground vehicles. In this paper, we will

  16. A Channelization-Based DOA Estimation Method for Wideband Signals.

    PubMed

    Guo, Rui; Zhang, Yue; Lin, Qianqiang; Chen, Zengping

    2016-01-01

    In this paper, we propose a novel direction of arrival (DOA) estimation method for wideband signals with sensor arrays. The proposed method splits the wideband array output into multiple frequency sub-channels and estimates the signal parameters using a digital channelization receiver. Based on the output sub-channels, a channelization-based incoherent signal subspace method (Channelization-ISM) and a channelization-based test of orthogonality of projected subspaces method (Channelization-TOPS) are proposed. Channelization-ISM applies narrowband signal subspace methods on each sub-channel independently. Then the arithmetic mean or geometric mean of the estimated DOAs from each sub-channel gives the final result. Channelization-TOPS measures the orthogonality between the signal and the noise subspaces of the output sub-channels to estimate DOAs. The proposed channelization-based method isolates signals in different bandwidths reasonably and improves the output SNR. It outperforms the conventional ISM and TOPS methods on estimation accuracy and dynamic range, especially in real environments. Besides, the parallel processing architecture makes it easy to implement on hardware. A wideband digital array radar (DAR) using direct wideband radio frequency (RF) digitization is presented. Experiments carried out in a microwave anechoic chamber with the wideband DAR are presented to demonstrate the performance. The results verify the effectiveness of the proposed method. PMID:27384566

  17. A Channelization-Based DOA Estimation Method for Wideband Signals

    PubMed Central

    Guo, Rui; Zhang, Yue; Lin, Qianqiang; Chen, Zengping

    2016-01-01

    In this paper, we propose a novel direction of arrival (DOA) estimation method for wideband signals with sensor arrays. The proposed method splits the wideband array output into multiple frequency sub-channels and estimates the signal parameters using a digital channelization receiver. Based on the output sub-channels, a channelization-based incoherent signal subspace method (Channelization-ISM) and a channelization-based test of orthogonality of projected subspaces method (Channelization-TOPS) are proposed. Channelization-ISM applies narrowband signal subspace methods on each sub-channel independently. Then the arithmetic mean or geometric mean of the estimated DOAs from each sub-channel gives the final result. Channelization-TOPS measures the orthogonality between the signal and the noise subspaces of the output sub-channels to estimate DOAs. The proposed channelization-based method isolates signals in different bandwidths reasonably and improves the output SNR. It outperforms the conventional ISM and TOPS methods on estimation accuracy and dynamic range, especially in real environments. Besides, the parallel processing architecture makes it easy to implement on hardware. A wideband digital array radar (DAR) using direct wideband radio frequency (RF) digitization is presented. Experiments carried out in a microwave anechoic chamber with the wideband DAR are presented to demonstrate the performance. The results verify the effectiveness of the proposed method. PMID:27384566

  18. Are free radicals involved in thiol-based redox signaling?

    PubMed

    Winterbourn, Christine C

    2015-03-01

    Cells respond to many stimuli by transmitting signals through redox-regulated pathways. It is generally accepted that in many instances signal transduction is via reversible oxidation of thiol proteins, although there is uncertainty about the specific redox transformations involved. The prevailing view is that thiol oxidation occurs by a two electron mechanism, most commonly involving hydrogen peroxide. Free radicals, on the other hand, are considered as damaging species and not generally regarded as important in cell signaling. This paper examines whether it is justified to dismiss radicals or whether they could have a signaling role. Although there is no direct evidence that radicals are involved in transmitting thiol-based redox signals, evidence is presented that they are generated in cells when these signaling pathways are activated. Radicals produce the same thiol oxidation products as two electron oxidants, although by a different mechanism, and at this point radical-mediated pathways should not be dismissed. There are unresolved issues about how radical mechanisms could achieve sufficient selectivity, but this could be possible through colocalization of radical-generating and signal-transducing proteins. Colocalization is also likely to be important for nonradical signaling mechanisms and identification of such associations should be a priority for advancing the field.

  19. An Evidence-Based Combining Classifier for Brain Signal Analysis

    PubMed Central

    Kheradpisheh, Saeed Reza; Nowzari-Dalini, Abbas; Ebrahimpour, Reza; Ganjtabesh, Mohammad

    2014-01-01

    Nowadays, brain signals are employed in various scientific and practical fields such as Medical Science, Cognitive Science, Neuroscience, and Brain Computer Interfaces. Hence, the need for robust signal analysis methods with adequate accuracy and generalizability is inevitable. The brain signal analysis is faced with complex challenges including small sample size, high dimensionality and noisy signals. Moreover, because of the non-stationarity of brain signals and the impacts of mental states on brain function, the brain signals are associated with an inherent uncertainty. In this paper, an evidence-based combining classifiers method is proposed for brain signal analysis. This method exploits the power of combining classifiers for solving complex problems and the ability of evidence theory to model as well as to reduce the existing uncertainty. The proposed method models the uncertainty in the labels of training samples in each feature space by assigning soft and crisp labels to them. Then, some classifiers are employed to approximate the belief function corresponding to each feature space. By combining the evidence raised from each classifier through the evidence theory, more confident decisions about testing samples can be made. The obtained results by the proposed method compared to some other evidence-based and fixed rule combining methods on artificial and real datasets exhibit the ability of the proposed method in dealing with complex and uncertain classification problems. PMID:24392125

  20. [Design of Electrocardiogram Signal Generator Based on Typical Electrocardiogram Database].

    PubMed

    Wang, Yuting; Wang, Xiaofei; Li, Dongshang; Liu, Guili

    2016-02-01

    Using LabVIEW programming and high-speed multifunction data acquisition card PCI-6251, we designed an electrocardiogram (ECG) signal generator based on Chinese typical ECG database. When the ECG signals are given off by the generator, the generator can also display the ECG information annotations at the same time, including waveform data and diagnostic results. It could be a useful assisting tool of ECG automatic diagnose instruments.

  1. Spectrin-based skeleton as an actor in cell signaling.

    PubMed

    Machnicka, B; Grochowalska, R; Bogusławska, D M; Sikorski, A F; Lecomte, M C

    2012-01-01

    This review focuses on the recent advances in functions of spectrins in non-erythroid cells. We discuss new data concerning the commonly known role of the spectrin-based skeleton in control of membrane organization, stability and shape, and tethering protein mosaics to the cellular motors and to all major filament systems. Particular effort has been undertaken to highlight recent advances linking spectrin to cell signaling phenomena and its participation in signal transduction pathways in many cell types.

  2. Microprocessor-based simulator of surface ECG signals

    NASA Astrophysics Data System (ADS)

    Martínez, A. E.; Rossi, E.; Siri, L. Nicola

    2007-11-01

    In this work, a simulator of surface electrocardiogram recorded signals (ECG) is presented. The device, based on a microcontroller and commanded by a personal computer, produces an analog signal resembling actual ECGs, not only in time course and voltage levels, but also in source impedance. The simulator is a useful tool for electrocardiograph calibration and monitoring, to incorporate as well in educational tasks and in clinical environments for early detection of faulty behaviour.

  3. [Design of Electrocardiogram Signal Generator Based on Typical Electrocardiogram Database].

    PubMed

    Wang, Yuting; Wang, Xiaofei; Li, Dongshang; Liu, Guili

    2016-02-01

    Using LabVIEW programming and high-speed multifunction data acquisition card PCI-6251, we designed an electrocardiogram (ECG) signal generator based on Chinese typical ECG database. When the ECG signals are given off by the generator, the generator can also display the ECG information annotations at the same time, including waveform data and diagnostic results. It could be a useful assisting tool of ECG automatic diagnose instruments. PMID:27382747

  4. Multimedia-Based Therapy Model for Non-Pharmacological Stroke with Decrease Impaired Muscle Strength

    NASA Astrophysics Data System (ADS)

    Hajar Puji Sejati, Rr; Muhimmah, Izzati; Mahtarami, Affan

    2016-01-01

    Stroke patients who experience a decrease in muscle strength need to do exercises so that they can increase their muscle strength. In order to enable the patient does exercise independently the multimedia-based stroke therapy model is needed. These exercises can be done independently, with supervision of the family member at home. So, we develop prototype of the multimedia-based therapy for the family member so that they can assist patients performing exercises without attending therapy session in hospital. This model was built according to the advices from physiotherapist and a medical rehabilitation doctor. This model has been evaluated through focused group discussion by physiotherapists. And they gave positive responses to this proposed model.

  5. Dimensional stability and strength of neutron-irradiated SiC-based fibers

    SciTech Connect

    Senor, D.J.; Youngblood, G.E.; Brimhall, J.L.; Trimble, D.J.; Newsome, G.A.; Woods, J.J.

    1996-12-31

    A variety of SiC-based fibers were characterized by measuring their length, density, and tensile strength in the unirradiated, thermal annealed, and irradiated conditions. The irradiation was conducted in the EBR-II to a dose of 43 dpa-SiC (185 EFPD) at a nominal irradiation temperature of 1000{degree}C. The annealed specimens were held at 1010{degree}C for 165 days to approximately duplicate the thermal exposure of the irradiated specimens. In general, the results of this study indicate the fibers that perform best in an irradiation environment are those that approach stoichiometric and crystalline SiC. Hi-Nicalon exhibited negligible densification, accompanied by an increase in tensile strength after irradiation. Nicalon CG possessed a higher tensile strength than Hi-Nicalon in the unirradiated condition, but was significantly weakened in the annealed and irradiated conditions. In addition, Nicalon CG exhibited unacceptable irradiation-induced shrinkage. While the irradiation stability of Hi-Nicalon was promising, other fibers with compositions closer to stoichiometric SiC may perform even better. This potential was suggested by the MER99 fiber, which displayed excellent dimensional stability. The principal drawback for the fully crystalline and stoichiometric fibers such as MER99 and Crystalline SiC is their low strength and flexibility caused by high flaw concentrations. 6 refs., 11 figs., 5 tabs.

  6. Effect of different surface treatments on tensile bond strength of silicone-based soft denture liner.

    PubMed

    Akin, Hakan; Tugut, Faik; Mutaf, Burcu; Akin, Gulsah; Ozdemir, A Kemal

    2011-11-01

    Failure of the bond between the acrylic resin and resilient liner material is commonly encountered in clinical practice. The purpose of this study was to investigate the effect of different surface treatments (sandblasting, Er:YAG, Nd:YAG, and KTP lasers) on tensile bond strength of silicone-based soft denture liner. Polymethyl methacrylate test specimens were fabricated and each received one of eight surface treatments: untreated (control), sandblasted, Er:YAG laser irradiated, sandblasted + Er:YAG laser irradiated, Nd:YAG laser irradiated, sandblasted + Nd:YAG laser irradiated, KTP laser irradiated, and sandblasted + KTP laser irradiated. The resilient liner specimens (n = 15) were processed between two polymethyl methacrylate (PMMA) blocks. Bonding strength of the liners to PMMA were compared by tensile test with the use of a universal testing machine at a crosshead speed of 5 mm/min. Kruskal-Wallis and Wilcoxon tests were used to analyze the data (α = 0.05). Altering the polymethyl methacrylate surface by Er:YAG laser significantly increased the bond strengths in polymethyl methacrylate/silicone specimens, however, sandblasting before applying a lining material had a weakening effect on the bond. In addition, Nd:YAG and KTP lasers were found to be ineffective for increasing the strength of the bond.

  7. The effect of configuration on strength, durability, and handle of Kevlar fabric-based materials

    NASA Technical Reports Server (NTRS)

    Reuter, L. L.; Munson, J. B.

    1977-01-01

    Five Kevlar based laminates and three Kevlar based coated materials were designed, hand made, and tested against comparative conventional Dacron based materials for strength, peel, tear, puncture, creases, and handle. Emphasis was placed on evaluating geometric orientation of constituents, use of elastomeric film in place of high modulus films, and the use of flying thread loom bias reinforcement of Kevlar yarns. Whereas, the performance of the Kevlar laminates was severely degraded by crease effects, significant gains in overall performance factors were shown for the coated Kevlar materials.

  8. Muscle Strength Enhancement Following Home-Based Virtual Cycling Training in Ambulatory Children with Cerebral Palsy

    ERIC Educational Resources Information Center

    Chen, Chia-Ling; Hong, Wei-Hsien; Cheng, Hsin-Yi Kathy; Liaw, Mei-Yun; Chung, Chia-Ying; Chen, Chung-Yao

    2012-01-01

    This study is the first well-designed randomized controlled trial to assess the effects of a novel home-based virtual cycling training (hVCT) program for improving muscle strength in children with spastic cerebral palsy (CP). Twenty-eight ambulatory children with spastic CP aged 6-12 years were randomly assigned to an hVCT group (n = 13) or a…

  9. Bayesian Inference for Signal-Based Seismic Monitoring

    NASA Astrophysics Data System (ADS)

    Moore, D.

    2015-12-01

    Traditional seismic monitoring systems rely on discrete detections produced by station processing software, discarding significant information present in the original recorded signal. SIG-VISA (Signal-based Vertically Integrated Seismic Analysis) is a system for global seismic monitoring through Bayesian inference on seismic signals. By modeling signals directly, our forward model is able to incorporate a rich representation of the physics underlying the signal generation process, including source mechanisms, wave propagation, and station response. This allows inference in the model to recover the qualitative behavior of recent geophysical methods including waveform matching and double-differencing, all as part of a unified Bayesian monitoring system that simultaneously detects and locates events from a global network of stations. We demonstrate recent progress in scaling up SIG-VISA to efficiently process the data stream of global signals recorded by the International Monitoring System (IMS), including comparisons against existing processing methods that show increased sensitivity from our signal-based model and in particular the ability to locate events (including aftershock sequences that can tax analyst processing) precisely from waveform correlation effects. We also provide a Bayesian analysis of an alleged low-magnitude event near the DPRK test site in May 2010 [1] [2], investigating whether such an event could plausibly be detected through automated processing in a signal-based monitoring system. [1] Zhang, Miao and Wen, Lianxing. "Seismological Evidence for a Low-Yield Nuclear Test on 12 May 2010 in North Korea". Seismological Research Letters, January/February 2015. [2] Richards, Paul. "A Seismic Event in North Korea on 12 May 2010". CTBTO SnT 2015 oral presentation, video at https://video-archive.ctbto.org/index.php/kmc/preview/partner_id/103/uiconf_id/4421629/entry_id/0_ymmtpps0/delivery/http

  10. Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training.

    PubMed

    Roberts, Llion A; Raastad, Truls; Markworth, James F; Figueiredo, Vandre C; Egner, Ingrid M; Shield, Anthony; Cameron-Smith, David; Coombes, Jeff S; Peake, Jonathan M

    2015-09-15

    We investigated functional, morphological and molecular adaptations to strength training exercise and cold water immersion (CWI) through two separate studies. In one study, 21 physically active men strength trained for 12 weeks (2 days per week), with either 10 min of CWI or active recovery (ACT) after each training session. Strength and muscle mass increased more in the ACT group than in the CWI group (P < 0.05). Isokinetic work (19%), type II muscle fibre cross-sectional area (17%) and the number of myonuclei per fibre (26%) increased in the ACT group (all P < 0.05), but not the CWI group. In another study, nine active men performed a bout of single-leg strength exercises on separate days, followed by CWI or ACT. Muscle biopsies were collected before and 2, 24 and 48 h after exercise. The number of satellite cells expressing neural cell adhesion molecule (NCAM) (10-30%) and paired box protein (Pax7) (20-50%) increased 24-48 h after exercise with ACT. The number of NCAM(+) satellite cells increased 48 h after exercise with CWI. NCAM(+) - and Pax7(+) -positive satellite cell numbers were greater after ACT than after CWI (P < 0.05). Phosphorylation of p70S6 kinase(Thr421/Ser424) increased after exercise in both conditions but was greater after ACT (P < 0.05). These data suggest that CWI attenuates the acute changes in satellite cell numbers and activity of kinases that regulate muscle hypertrophy, which may translate to smaller long-term training gains in muscle strength and hypertrophy. The use of CWI as a regular post-exercise recovery strategy should be reconsidered.

  11. Cloning of a phosphatidylinositol 4-kinase gene based on fiber strength transcriptome QTL mapping in the cotton species Gossypium barbadense.

    PubMed

    Liu, H W; Shi, R F; Wang, X F; Pan, Y X; Zang, G Y; Ma, Z Y

    2012-09-25

    Sea Island cotton (Gossypium barbadense) is highly valued for its superior fiber qualities, especially fiber strength. Based on a transcript-derived fragment originated from transcriptome QTL mapping, a fiber strength related candidate gene of phosphatidylinositol 4-kinase cDNA, designated as GbPI4K, was first cloned, and its expression was characterized in the secondary cell wall thickening stage of G. barbadense fibers. The ORF of GbPI4K was found to be 1926 bp in length and encoded a predicted protein of 641 amino acid residues. The putative protein contained a clear PI3/4K kinase catalytic domain and fell into the plant type II PI4K cluster in phylogenetic analysis. In this study, the expression of cotton PI4K protein was also induced in Escherichia coli BL21 (DE3) as a fused protein. Semi-quantitative RT-PCR analysis showed that the gene expressed in the root, hypocotyl and leaf of the cotton plants. Real-time RT-PCR indicated that this gene in Sea Island cotton fibers expressed 10 days longer than that in Upland cotton fibers, and the main expression difference of PI4K between Sea Island cotton and Upland cotton in fibers was located in the secondary cell wall thickening stage of the fiber. Further analysis indicated that PI4K is a crucial factor in the ability of Rac proteins to regulate phospholipid signaling pathways.

  12. Novel strength test battery to permit evidence-based paralympic classification.

    PubMed

    Beckman, Emma M; Newcombe, Peter; Vanlandewijck, Yves; Connick, Mark J; Tweedy, Sean M

    2014-06-01

    Ordinal-scale strength assessment methods currently used in Paralympic athletics classification prevent the development of evidence-based classification systems. This study evaluated a battery of 7, ratio-scale, isometric tests with the aim of facilitating the development of evidence-based methods of classification. This study aimed to report sex-specific normal performance ranges, evaluate test-retest reliability, and evaluate the relationship between the measures and body mass.Body mass and strength measures were obtained from 118 participants-63 males and 55 females-ages 23.2 years ± 3.7 (mean ± SD). Seventeen participants completed the battery twice to evaluate test-retest reliability. The body mass-strength relationship was evaluated using Pearson correlations and allometric exponents.Conventional patterns of force production were observed. Reliability was acceptable (mean intraclass correlation = 0.85). Eight measures had moderate significant correlations with body size (r = 0.30-61). Allometric exponents were higher in males than in females (mean 0.99 vs 0.30).Results indicate that this comprehensive and parsimonious battery is an important methodological advance because it has psychometric properties critical for the development of evidence-based classification. Measures were interrelated with body size, indicating further research is required to determine whether raw measures require normalization in order to be validly applied in classification. PMID:25068950

  13. Novel strength test battery to permit evidence-based paralympic classification.

    PubMed

    Beckman, Emma M; Newcombe, Peter; Vanlandewijck, Yves; Connick, Mark J; Tweedy, Sean M

    2014-06-01

    Ordinal-scale strength assessment methods currently used in Paralympic athletics classification prevent the development of evidence-based classification systems. This study evaluated a battery of 7, ratio-scale, isometric tests with the aim of facilitating the development of evidence-based methods of classification. This study aimed to report sex-specific normal performance ranges, evaluate test-retest reliability, and evaluate the relationship between the measures and body mass.Body mass and strength measures were obtained from 118 participants-63 males and 55 females-ages 23.2 years ± 3.7 (mean ± SD). Seventeen participants completed the battery twice to evaluate test-retest reliability. The body mass-strength relationship was evaluated using Pearson correlations and allometric exponents.Conventional patterns of force production were observed. Reliability was acceptable (mean intraclass correlation = 0.85). Eight measures had moderate significant correlations with body size (r = 0.30-61). Allometric exponents were higher in males than in females (mean 0.99 vs 0.30).Results indicate that this comprehensive and parsimonious battery is an important methodological advance because it has psychometric properties critical for the development of evidence-based classification. Measures were interrelated with body size, indicating further research is required to determine whether raw measures require normalization in order to be validly applied in classification.

  14. Novel Strength Test Battery to Permit Evidence-Based Paralympic Classification

    PubMed Central

    Beckman, Emma M.; Newcombe, Peter; Vanlandewijck, Yves; Connick, Mark J.; Tweedy, Sean M.

    2014-01-01

    Abstract Ordinal-scale strength assessment methods currently used in Paralympic athletics classification prevent the development of evidence-based classification systems. This study evaluated a battery of 7, ratio-scale, isometric tests with the aim of facilitating the development of evidence-based methods of classification. This study aimed to report sex-specific normal performance ranges, evaluate test–retest reliability, and evaluate the relationship between the measures and body mass. Body mass and strength measures were obtained from 118 participants—63 males and 55 females—ages 23.2 years ± 3.7 (mean ± SD). Seventeen participants completed the battery twice to evaluate test–retest reliability. The body mass–strength relationship was evaluated using Pearson correlations and allometric exponents. Conventional patterns of force production were observed. Reliability was acceptable (mean intraclass correlation = 0.85). Eight measures had moderate significant correlations with body size (r = 0.30–61). Allometric exponents were higher in males than in females (mean 0.99 vs 0.30). Results indicate that this comprehensive and parsimonious battery is an important methodological advance because it has psychometric properties critical for the development of evidence-based classification. Measures were interrelated with body size, indicating further research is required to determine whether raw measures require normalization in order to be validly applied in classification. PMID:25068950

  15. Prompt Earthquake Detection based on Transient Gravity Signals.

    NASA Astrophysics Data System (ADS)

    Juhel, K.; Montagner, J. P.; Barsuglia, M.; Ampuero, J. P.; Chassande-Mottin, E.; Harms, J.; Whiting, B. F.; Bernard, P.; Clevede, E.; Lognonne, P. H.

    2015-12-01

    The deformation caused by an earthquake induces changes in the Earth's gravitational field known as coseismic gravity changes, especially during mega-earthquakes. So far, only static gravity changes have been detected, considerably after the end of the rupture. Since gravity changes propagate at the speed of light, a dynamic gravity signal is produced everywhere on Earth during the rupture, even before the arrival of seismic waves. Here we confirm the evidence of this prompt gravity signal. We have analyzed, with a statistical blind method, the data recorded during the 2011 Mw 9.0 Tohoku-oki earthquake by a superconducting gravimeter in the underground Kamioka observatory, about 500 km away from the earthquake centroid. We find that a gravity signal is present before the P wave arrival, with a statistical significance of more than 99%. The signal amplitude is a fraction of μGal, consistent in sign and order-of-magnitude with theoretical predictions. A similar analysis is being conducted on data recorded by the broadband seismometers of the japanese network Fnet. Numerical simulations based on normal-mode method and an analytical model of dynamic gravity signals are used to compute synthetic seismograms, and thus characterize the prompt gravity signal. The robust detection of this prompt gravity signal with instruments more immune to the background seismic noise could, in principle, open new directions in earthquake seismology and overcome limitations of current earthquake early-warning systems imposed by the propagation speed of seismic waves.

  16. Seamless measurement technology of transient signals based on approximate entropy

    NASA Astrophysics Data System (ADS)

    Jiang, Jun; Tian, Shulin; Guo, Lianping; Huang, Wuhuang

    2016-10-01

    The acquisition of waveforms and the analysis of transient characteristics of signals are the fundamental tasks for time-domain measurement, while the reduction of the measuring gap till seamless measurement is extremely important to the acquisition, measurement, and analysis of transient signals. This paper, aimed at the seamless time-domain measurement of non-stationary transient signals, proposes an approximate entropy-based characteristic signal extraction algorithm on the basis of information entropy theories. The algorithm quantitatively describes the complexity (amount of information) of sampled signals using the approximate entropy value, self-adaptively captures characteristic signals under the control of the approximate entropy in real time, extracts the critical or useful information, and removes redundant or useless information so as to reduce the time consumption of processing data and displaying waveforms and realize the seamless time-domain measurement of transient signals finally. Experimental results show that the study could provide a new method for the design of electronic measuring instrument with seamless measurement capability.

  17. Cross Psi(B)-energy operator-based signal detection.

    PubMed

    Boudraa, Abdel-Ouahab; Cexus, Jean-Christophe; Abed-Meraim, Karim

    2008-06-01

    In this paper, two methods for signal detection and time-delay estimation based on the cross Psi(B)-energy operator are proposed. These methods are well suited for mono-component AM-FM signals. The Psi(B) energy operator measures how much one signal is present in another one. The peak of the Psi(B) operator corresponds to the maximum of interaction between the two signals. Compared to the cross-correlation function, the Psi(B) operator includes temporal information and relative changes of the signal which are reflected in its first and second derivatives. The discrete version of the continuous-time form of the Psi(B) operator, which is used in its implementation, is presented. The methods are illustrated on synthetic and real signals and the results compared to those of the matched filter and the cross correlation. The real signals correspond to impulse responses of buried objects obtained by active sonar in iso-speed single path environments. PMID:18537379

  18. Cross Psi(B)-energy operator-based signal detection.

    PubMed

    Boudraa, Abdel-Ouahab; Cexus, Jean-Christophe; Abed-Meraim, Karim

    2008-06-01

    In this paper, two methods for signal detection and time-delay estimation based on the cross Psi(B)-energy operator are proposed. These methods are well suited for mono-component AM-FM signals. The Psi(B) energy operator measures how much one signal is present in another one. The peak of the Psi(B) operator corresponds to the maximum of interaction between the two signals. Compared to the cross-correlation function, the Psi(B) operator includes temporal information and relative changes of the signal which are reflected in its first and second derivatives. The discrete version of the continuous-time form of the Psi(B) operator, which is used in its implementation, is presented. The methods are illustrated on synthetic and real signals and the results compared to those of the matched filter and the cross correlation. The real signals correspond to impulse responses of buried objects obtained by active sonar in iso-speed single path environments.

  19. Energy free microwave based signal communication using ratchet effect

    NASA Astrophysics Data System (ADS)

    Kannan, E. S.; Bisotto, I.; Portal, J.-C.; Beck, T. J.; Jalabert, L.

    2012-10-01

    The ratchet based microwave detectors are implemented as receivers of amplitude, frequency, and pulse width modulated signals. The detector has a peak responsivity of 994 V/W and has excellent signal to noise ratio in the measurement bandwidth with its noise equivalent power of about 0.01 pico W/√Hz and 6.3 × 107 cm√Hz/W detectivity. The frequency limit of detection can be tuned by a suitable choice of the antidot parameters. The advantages of the utilizing ratchet based active antennas are simple circuitry, controllable spectral range, no power consumption, and natural rejection of stray electromagnetic radiations.

  20. Development of strength and conductivity in deformation processed copper base alloys

    SciTech Connect

    Insoo, M.

    1992-07-20

    Deformation processed copper based composite alloys have been recently investigated. In these composite alloys, copper, a matrix material, contributes to a high thermal and electrical conductivity, and a second phase material such as Fe, Nb, Cr, Mo, Ta and W acts as a reinforcement of the strength of the composites. Tungsten was chosen as the bcc phase in the first experiment because W has a high melting temperature which is expected to reduce the decrease in high temperature strength resulting from coarsening of fibers. However, brittleness of tungsten may bring crack problems. Because the matrix is ductile but the second phase is hard enough to resist the external forces, cracks may occur at the interfaces between deformed matrix and undeformed second phase. The purpose of the first experiment is to investigate the possibility of deformation of Cu-W compacts.

  1. Living better with dementia: strengths-based social work practice and dementia care.

    PubMed

    McGovern, Justine

    2015-01-01

    This article first argues that quality of life is possible despite the onset of dementia in late life. It also demonstrates how core concepts of social work practice, such as family systems theory, the strengths perspective, and use of self, can be applied to practice with dementia-affected persons. In addition, it provides practical suggestions for supporting care partners in nurturing "we-ness", focusing on what remains rather than was is lost, and remaining authentic. When strengths-based social work practice is integrated into dementia care protocols, wellbeing can increase. As a result, the more than 40 million persons worldwide who are affected by dementia do not have to resign themselves to the despair, devastation and inevitable demise of quality of life that dominate perception of the illness.

  2. High-strength clad current collector for silicon-based negative electrode in lithium ion battery

    NASA Astrophysics Data System (ADS)

    Kataoka, Riki; Oda, Yoshimitsu; Inoue, Ryouji; Kitta, Mitsunori; Kiyobayashi, Tetsu

    2016-01-01

    We develop a clad foil current collector with a high tensile strength that endures a large volume change in the active material during the charge and discharge, such as the Si-based materials. The nano-Si negative electrode with the clad current collector retains 76% of the initial capacity after 40 cycles, while the capacity of the nano-Si electrode with a conventional Cu foil drops to less than 70% only after 10 cycles. A full cell with the SiO negative electrode and the LiFePO4 positive electrode retains more than 90% of its capacity at the 10th cycle after 800 cycles. The conventional rolled Cu foil wrinkles during the cycling test. The high-strength clad current foil hardly deforms during the test regardless of the electrode size.

  3. Lunar soil strength estimation based on Chang'E-3 images

    NASA Astrophysics Data System (ADS)

    Gao, Yang; Spiteri, Conrad; Li, Chun-Lai; Zheng, Yong-Chun

    2016-11-01

    Chang'E-3 (CE-3) was the third mission by China to explore the Moon which had landed two spacecraft, the CE-3 lander and Yutu rover on the lunar surface in late 2013. The paper presents analytical results of high-resolution terrain data taken by CE-3's onboard cameras. The image data processing aims to extract sinkage profiles of the wheel tracks during the rover traverse. Further analysis leads to derivation or estimation of lunar soil physical properties (in terms of strength and stiffness) based on the wheel sinkage, despite the fact Yutu does not possess in situ soil measurement instruments. Our findings indicate that the lunar soil at the CE-3 landing site has similar stiffness to what is measured at the Luna 17 landing site but has much less strength compared to the Apollo 15 landing site.

  4. Vitamin C and E supplementation alters protein signalling after a strength training session, but not muscle growth during 10 weeks of training.

    PubMed

    Paulsen, G; Hamarsland, H; Cumming, K T; Johansen, R E; Hulmi, J J; Børsheim, E; Wiig, H; Garthe, I; Raastad, T

    2014-12-15

    This study investigated the effects of vitamin C and E supplementation on acute responses and adaptations to strength training. Thirty-two recreationally strength-trained men and women were randomly allocated to receive a vitamin C and E supplement (1000 mg day(-1) and 235 mg day(-1), respectively), or a placebo, for 10 weeks. During this period the participants' training involved heavy-load resistance exercise four times per week. Muscle biopsies from m. vastus lateralis were collected, and 1 repetition maximum (1RM) and maximal isometric voluntary contraction force, body composition (dual-energy X-ray absorptiometry), and muscle cross-sectional area (magnetic resonance imaging) were measured before and after the intervention. Furthermore, the cellular responses to a single exercise session were assessed midway in the training period by measurements of muscle protein fractional synthetic rate and phosphorylation of several hypertrophic signalling proteins. Muscle biopsies were obtained from m. vastus lateralis twice before, and 100 and 150 min after, the exercise session (4 × 8RM, leg press and knee-extension). The supplementation did not affect the increase in muscle mass or the acute change in protein synthesis, but it hampered certain strength increases (biceps curl). Moreover, increased phosphorylation of p38 mitogen-activated protein kinase, Extracellular signal-regulated protein kinases 1 and 2 and p70S6 kinase after the exercise session was blunted by vitamin C and E supplementation. The total ubiquitination levels after the exercise session, however, were lower with vitamin C and E than placebo. We concluded that vitamin C and E supplementation interfered with the acute cellular response to heavy-load resistance exercise and demonstrated tentative long-term negative effects on adaptation to strength training.

  5. Vitamin C and E supplementation alters protein signalling after a strength training session, but not muscle growth during 10 weeks of training

    PubMed Central

    Paulsen, G; Hamarsland, H; Cumming, K T; Johansen, R E; Hulmi, J J; Børsheim, E; Wiig, H; Garthe, I; Raastad, T

    2014-01-01

    This study investigated the effects of vitamin C and E supplementation on acute responses and adaptations to strength training. Thirty-two recreationally strength-trained men and women were randomly allocated to receive a vitamin C and E supplement (1000 mg day−1 and 235 mg day−1, respectively), or a placebo, for 10 weeks. During this period the participants’ training involved heavy-load resistance exercise four times per week. Muscle biopsies from m. vastus lateralis were collected, and 1 repetition maximum (1RM) and maximal isometric voluntary contraction force, body composition (dual-energy X-ray absorptiometry), and muscle cross-sectional area (magnetic resonance imaging) were measured before and after the intervention. Furthermore, the cellular responses to a single exercise session were assessed midway in the training period by measurements of muscle protein fractional synthetic rate and phosphorylation of several hypertrophic signalling proteins. Muscle biopsies were obtained from m. vastus lateralis twice before, and 100 and 150 min after, the exercise session (4 × 8RM, leg press and knee-extension). The supplementation did not affect the increase in muscle mass or the acute change in protein synthesis, but it hampered certain strength increases (biceps curl). Moreover, increased phosphorylation of p38 mitogen-activated protein kinase, Extracellular signal-regulated protein kinases 1 and 2 and p70S6 kinase after the exercise session was blunted by vitamin C and E supplementation. The total ubiquitination levels after the exercise session, however, were lower with vitamin C and E than placebo. We concluded that vitamin C and E supplementation interfered with the acute cellular response to heavy-load resistance exercise and demonstrated tentative long-term negative effects on adaptation to strength training. PMID:25384788

  6. A Schiff base connectivity switch in sensory rhodopsin signaling.

    PubMed

    Sineshchekov, Oleg A; Sasaki, Jun; Phillips, Brian J; Spudich, John L

    2008-10-21

    Sensory rhodopsin I (SRI) in Halobacterium salinarum acts as a receptor for single-quantum attractant and two-quantum repellent phototaxis, transmitting light stimuli via its bound transducer HtrI. Signal-inverting mutations in the SRI-HtrI complex reverse the single-quantum response from attractant to repellent. Fast intramolecular charge movements reported here reveal that the unphotolyzed SRI-HtrI complex exists in two conformational states, which differ by their connection of the retinylidene Schiff base in the SRI photoactive site to inner or outer half-channels. In single-quantum photochemical reactions, the conformer with the Schiff base connected to the cytoplasmic (CP) half-channel generates an attractant signal, whereas the conformer with the Schiff base connected to the extracellular (EC) half-channel generates a repellent signal. In the wild-type complex the conformer equilibrium is poised strongly in favor of that with CP-accessible Schiff base. Signal-inverting mutations shift the equilibrium in favor of the EC-accessible Schiff base form, and suppressor mutations shift the equilibrium back toward the CP-accessible Schiff base form, restoring the wild-type phenotype. Our data show that the sign of the behavioral response directly correlates with the state of the connectivity switch, not with the direction of proton movements or changes in acceptor pK(a). These findings identify a shared fundamental process in the mechanisms of transport and signaling by the rhodopsin family. Furthermore, the effects of mutations in the HtrI subunit of the complex on SRI Schiff base connectivity indicate that the two proteins are tightly coupled to form a single unit that undergoes a concerted conformational transition.

  7. Effect of surface treatments on shear bond strength of denture teeth to denture base resins

    PubMed Central

    Bahrani, Farideh; Khaledi, Amir Ali Reza

    2014-01-01

    Background: Debonding of denture teeth from denture bases is the most common failure in removable dentures. The purpose of this study was to evaluate the effect of surface treatments on shear bond strength of denture teeth to heat-polymerized and autopolymerized denture base resins. Materials and Methods: In this experimental in vitro study, 60 maxillary central incisor acrylic teeth were divided into two groups. Group M was polymerized with heat-polymerized acrylic resin (Meliodent) by compression molding technique and group F was processed by autopolymerized acrylic resin (Futura Gen) by injection molding technique. Within each group, specimens were divided into three subgroups according to the teeth surface treatments (n = 10): (1) ground surface as the control group (M1 and F1), (2) ground surface combined with monomer application (M2 and F2), and (3) airborne particle abrasion by 50 μm Al2O3 (M3 and F3). The shear bond strengths of the specimens were tested by universal testing machine with crosshead speed of 5 mm/min. Data were analyzed by two-way analysis of variance (ANOVA) and Tukey's honestly significant difference (HSD) tests (P < 0.05). Results: The mean shear bond strengths of the studied groups were 96.40 ± 14.01, 124.70 ± 15.64, and 118 ± 16.38 N for M1, M2, and M3 and 87.90 ± 13.48, 117 ± 13.88, and 109.70 ± 13.78 N for F1, F2, and F3, respectively. The surface treatment of the denture teeth significantly affected their shear bond strengths to the both the denture base resins (P < 0.001). However, there were no significant differences between the groups treated by monomer or airborne particle abrasion (P = 0.29). The highest percentage of failure mode was mixed in Meliodent and adhesive in Futura Gen. Conclusion: Monomer application and airborne particle abrasion of the ridge lap area of the denture teeth improved their shear bond strengths to the denture base resins regardless of the type of polymerization. PMID:24688570

  8. Neurophysiologic and Cardiac Signals Simulator Based on Microconverter

    NASA Astrophysics Data System (ADS)

    Tavares, Maurício C.; Richter, Carlos M.; Oliveira, Tiago R.; Moraes, Raimes

    This paper describes a microconverter-based electronic device developed to simulate auditory evoked potentials of short, middle and long latencies, ECG and electronystagmographic signals. The simulator reproduces real physiologic signals from sampled AEP and ECG waveforms instead of generating them based on equations. The main simulator part is the ADuC841 microconverter (single-cycle 20 MHz 8052 core, FLASH memory and two 12-bit DACs). Called SimPac I, the equipment is portable and easy to operate, being a worthy tool for calibration of AEP, ECG, ENG and VENG systems during manufacture and maintenance. It can also be used in the development and testing of DSP algorithms intended to filter and/or average the above mentioned signals. As result, examples of several waveforms generated by the SimPac I are shown.

  9. α-Catenin and Vinculin Cooperate to Promote High E-cadherin-based Adhesion Strength*

    PubMed Central

    Thomas, William A.; Boscher, Cécile; Chu, Yeh-Shiu; Cuvelier, Damien; Martinez-Rico, Clara; Seddiki, Rima; Heysch, Julie; Ladoux, Benoit; Thiery, Jean Paul; Mege, René-Marc; Dufour, Sylvie

    2013-01-01

    Maintaining cell cohesiveness within tissues requires that intercellular adhesions develop sufficient strength to support traction forces applied by myosin motors and by neighboring cells. Cadherins are transmembrane receptors that mediate intercellular adhesion. The cadherin cytoplasmic domain recruits several partners, including catenins and vinculin, at sites of cell-cell adhesion. Our study used force measurements to address the role of αE-catenin and vinculin in the regulation of the strength of E-cadherin-based adhesion. αE-catenin-deficient cells display only weak aggregation and fail to strengthen intercellular adhesion over time, a process rescued by the expression of αE-catenin or chimeric E-cadherin·αE-catenins, including a chimera lacking the αE-catenin dimerization domain. Interestingly, an αE-catenin mutant lacking the modulation and actin-binding domains restores cadherin-dependent cell-cell contacts but cannot strengthen intercellular adhesion. The expression of αE-catenin mutated in its vinculin-binding site is defective in its ability to rescue cadherin-based adhesion strength in cells lacking αE-catenin. Vinculin depletion or the overexpression of the αE-catenin modulation domain strongly decreases E-cadherin-mediated adhesion strength. This supports the notion that both molecules are required for intercellular contact maturation. Furthermore, stretching of cell doublets increases vinculin recruitment and α18 anti-αE-catenin conformational epitope immunostaining at cell-cell contacts. Taken together, our results indicate that αE-catenin and vinculin cooperatively support intercellular adhesion strengthening, probably via a mechanoresponsive link between the E-cadherin·β-catenin complexes and the underlying actin cytoskeleton. PMID:23266828

  10. The impact of polymerization method on tensile bond strength between denture base and acrylic teeth.

    PubMed

    Hashem, Mohamed; Binmgren, Mohammed A; Alsaleem, Samah O; Vellappally, Sajith; Assery, Mansour K; Sukumaran, Anil

    2014-05-01

    Failure of the bond between acrylic teeth and the denture base resin interface is one of the major concern in prosthodontics. The new generation of denture bases that utilize alternate polymerization methods are being introduced in the market. The aim of the study is to evaluate the influence of polymerization methods on bonding quality between the denture base and artificial teeth. Sixty test specimens were prepared (20 in each group) and were polymerized using heat, microwave and visible light curing. The tensile strength was recorded for each of the samples, and the results were analyzed statistically. The light-activated Eclipse™ System showed the highest tensile strength, followed by heat curing. The microwave-cured samples exhibited the least bonding to the acrylic teeth. Within the limitations of this study, it can be concluded that the new generation of light-cured denture bases showed significantly better bonding to acrylic teeth and can be used as an alternative to the conventional heat-polymerized denture base.

  11. The impact of polymerization method on tensile bond strength between denture base and acrylic teeth.

    PubMed

    Hashem, Mohamed; Binmgren, Mohammed A; Alsaleem, Samah O; Vellappally, Sajith; Assery, Mansour K; Sukumaran, Anil

    2014-01-01

    Failure of the bond between acrylic teeth and the denture base resin interface is one of the major concern in prosthodontics. The new generation of denture bases that utilize alternate polymerization methods are being introduced in the market. The aim of the study is to evaluate the influence of polymerization methods on bonding quality between the denture base and artificial teeth. Sixty test specimens were prepared (20 in each group) and were polymerized using heat, microwave and visible light curing. The tensile strength was recorded for each of the samples, and the results were analyzed statistically. The light-activated Eclipse™ System showed the highest tensile strength, followed by heat curing. The microwave-cured samples exhibited the least bonding to the acrylic teeth. Within the limitations of this study, it can be concluded that the new generation of light-cured denture bases showed significantly better bonding to acrylic teeth and can be used as an alternative to the conventional heat-polymerized denture base. PMID:25307813

  12. Application of Strength Diagnosis.

    ERIC Educational Resources Information Center

    Newton, Robert U.; Dugan, Eric

    2002-01-01

    Discusses the various strength qualities (maximum strength, high- and low-load speed strength, reactive strength, rate of force development, and skill performance), noting why a training program design based on strength diagnosis can lead to greater efficacy and better performance gains for the athlete. Examples of tests used to assess strength…

  13. Microprocessor Based Real-Time Monitoring of Multiple ECG Signals

    PubMed Central

    Nasipuri, M.; Basu, D.K.; Dattagupta, R.; Kundu, M.; Banerjee, S.

    1987-01-01

    A microprocessor based system capable of realtime monitoring of multiple ECG signals has been described. The system consists of a number of microprocessors connected in a hierarchical fashion and capable of working concurrently on ECG data collected from different channels. The system can monitor different arrhythmic abnormalities for at least 36 patients even for a heart rate of 500 beats/min.

  14. Towards navigation based on 120 satellites: Analyzing the new signals

    NASA Astrophysics Data System (ADS)

    Gao, Grace Xingxin

    Global Navigation Satellite Systems (GNSS) are experiencing a new era. The US Global Positioning System (GPS) now serves over 300 million users in a bewildering breadth of applications. The Russian GLONASS is enjoying a startling renaissance based on the recovery of the Russian economy. In addition, the European Union is developing the Galileo system that promises to place 30 more satellites in medium Earth orbit. If that is not enough, China has started their Compass system project that promises a rich combination of satellites in medium and geostationary earth orbit. All of these satellites will broadcast at least three civil signals in a multiplicity of frequency bands. If all of these new satellites are launched, we will have 120 satellites and over 300 signals in space for global navigation by 2020. So far, two test satellites of the European Galileo and one satellite from the Chinese Compass have been launched. The new satellites and new signals create a great opportunity for GNSS receivers to gain more redundancy and accuracy. On the other hand, the new GNSS signals could interfere with each other since their frequency bands overlap. Moreover, when the satellites were put into orbit, the signal specifications were not available to the public. This mystery made it impossible for GNSS receivers to acquire and track the new satellites. It was also impossible to analyze the interference among GNSS satellites. Thus, there was an urgent and great need for discovering the unknown signal characteristics. The contribution of this work is to design algorithms for deciphering all the new test satellite signals from the Galileo and Compass satellite programs. We reveal the spread spectrum codes for all the signals on the prototype satellites listed above. In addition, we derive the underlying code generators based on a modification of the Berlekamp-Massey algorithm for solving systems of equations over finite fields. Several receiver companies, such as Trimble

  15. Model-based sediment classification using single-beam echosounder signals.

    PubMed

    Snellen, Mirjam; Siemes, Kerstin; Simons, Dick G

    2011-05-01

    Acoustic remote sensing techniques for mapping sediment properties are of interest due to their low costs and high coverage. Model-based approaches directly couple the acoustic signals to sediment properties. Despite the limited coverage of the single-beam echosounder (SBES), it is widely used. Having available model-based SBES classification tools, therefore, is important. Here, two model-based approaches of different complexity are compared to investigate their practical applicability. The first approach is based on matching the echo envelope. It maximally exploits the information available in the signal but requires complex modeling and optimization. To minimize computational costs, the efficient differential evolution method is used. The second approach reduces the information of the signal to energy only and directly relates this to the reflection coefficient to obtain quantitative information about the sediment parameters. The first approach provides information over a variety of sediment types. In addition to sediment mean grain size, it also provides estimates for the spectral strength and volume scattering parameter. The need to account for all three parameters is demonstrated, justifying computational expenses. In the second approach, the lack of information on these parameters and the limited SBES beamwidth are demonstrated to hamper the conversion of echo energy to reflection coefficient. PMID:21568391

  16. Model-based sediment classification using single-beam echosounder signals.

    PubMed

    Snellen, Mirjam; Siemes, Kerstin; Simons, Dick G

    2011-05-01

    Acoustic remote sensing techniques for mapping sediment properties are of interest due to their low costs and high coverage. Model-based approaches directly couple the acoustic signals to sediment properties. Despite the limited coverage of the single-beam echosounder (SBES), it is widely used. Having available model-based SBES classification tools, therefore, is important. Here, two model-based approaches of different complexity are compared to investigate their practical applicability. The first approach is based on matching the echo envelope. It maximally exploits the information available in the signal but requires complex modeling and optimization. To minimize computational costs, the efficient differential evolution method is used. The second approach reduces the information of the signal to energy only and directly relates this to the reflection coefficient to obtain quantitative information about the sediment parameters. The first approach provides information over a variety of sediment types. In addition to sediment mean grain size, it also provides estimates for the spectral strength and volume scattering parameter. The need to account for all three parameters is demonstrated, justifying computational expenses. In the second approach, the lack of information on these parameters and the limited SBES beamwidth are demonstrated to hamper the conversion of echo energy to reflection coefficient.

  17. Rough-set-based ADR signaling from spontaneous reporting data with missing values.

    PubMed

    Lin, Wen-Yang; Lan, Lin; Huang, Feng-Hsiung; Wang, Min-Hsien

    2015-12-01

    Spontaneous reporting systems of adverse drug events have been widely established in many countries to collect as could as possible all adverse drug events to facilitate the detection of suspected ADR signals via some statistical or data mining methods. Unfortunately, due to privacy concern or other reasons, the reporters sometimes may omit consciously some attributes, causing many missing values existing in the reporting database. Most of research work on ADR detection or methods applied in practice simply adopted listwise deletion to eliminate all data with missing values. Very little work has noticed the possibility and examined the effect of including the missing data in the process of ADR detection. This paper represents our endeavor towards the exploration of this question. We aim at inspecting the feasibility of applying rough set theory to the ADR detection problem. Based on the concept of utilizing characteristic set based approximation to measure the strength of ADR signals, we propose twelve different rough set based measuring methods and show only six of them are feasible for the purpose. Experimental results conducted on the FARES database show that our rough-set-based approach exhibits similar capability in timeline warning of suspicious ADR signals as traditional method with missing deletion, and sometimes can yield noteworthy measures earlier than the traditional method.

  18. Self directed home based electrical muscle stimulation training improves exercise tolerance and strength in healthy elderly.

    PubMed

    Caulfield, Brian; Prendergast, Ann; Rainsford, Gary; Minogue, Conor

    2013-01-01

    Advancing age is associated with a gradual decline in muscle strength, exercise tolerance and subsequent capacity for activities of daily living. It is important that we develop effective strategies to halt this process of gradual decline in order to enhance functional ability and capacity for independent living. To achieve this, we must overcome the challenge of sustaining ongoing engagement in physical exercise programmes in the sedentary elderly population, particularly those who experience barriers to exercise participation. Recent developments in electrical muscle stimulation technology could provide a potential solution. In this pilot case-control study we investigated the effects of a self-directed home based programme of electrical muscle stimulation training on muscle strength and exercise tolerance in a group of 16 healthy elderly volunteers (10f, 6m). Study participants completed 30 separate 1-hour electrical muscle stimulation sessions at home over a 6-week period. We observed significant improvements in quadriceps muscle strength and 6-minute walk distance, suggesting that this form of electrical muscle stimulation training has promise as an exercise modality in the elderly population.

  19. Effect of silorane-based adhesive system on bond strength between composite and dentin substrate

    PubMed Central

    Pereira, Jefferson Ricardo; Júnior, Lindomar Corrêa; de Souza Almeida, Mauro; do Valle, Accácio Lins; Honório, Heitor Marques; Vidotti, Hugo Alberto; De Souza, Grace Mendonca

    2015-01-01

    Context: The complexities of the oral environment, the dentin substrate, and the different bond and composite resin systems represent a challenge to the maintenance of reasonable bond between the composite resin and the tooth structure. Aims: To evaluate the effect of the adhesive system on bond strength between silorane-based composite resin and dentin. Materials and Methods: Fourteen human molars extracted were selected and vertically cut into 3 dentin fragments, randomly divided among the experimental groups and restored with Z250 and P90 composite resin using different adhesive protocols (Adper Single Bond 2, Silorano primer, Adper SE Plus, and Scotchbond Multiuse). Two composite resin cylinders were built up on each dentin surface (n = 10) and subjected to a micro-shear bond strength test. Statistical Analysis Used: Kruskal–Wallis one-way analysis of variance and Tukey test (P = 0.05). Results: According to the results, Kruskal–Wallis test evidenced at least one statistical significant difference (P = 0.001). The Tukey test showed statistically significant differences among the group (P < 0.05). Group PSM8 (P90 + SM) showed statically significant higher results when compared with groups PSP4 (P90 + SP), PSB2 (P90 + SB), and ZSE5 (Z250 + SE). Conclusion: The results evidenced that the monomer of the adhesive system has an effect on bond strength between the composite resin and dentin. PMID:26752846

  20. Fast tablet tensile strength prediction based on non-invasive analytics.

    PubMed

    Halenius, Anna; Lakio, Satu; Antikainen, Osmo; Hatara, Juha; Yliruusi, Jouko

    2014-06-01

    In this paper, linkages between tablet surface roughness, tablet compression forces, material properties, and the tensile strength of tablets were studied. Pure sodium halides (NaF, NaBr, NaCl, and NaI) were chosen as model substances because of their simple and similar structure. Based on the data available in the literature and our own measurements, various models were made to predict the tensile strength of the tablets. It appeared that only three parameters-surface roughness, upper punch force, and the true density of material-were needed to predict the tensile strength of a tablet. Rather surprising was that the surface roughness alone was capable in the prediction. The used new 3D imaging method (Flash sizer) was roughly a thousand times quicker in determining tablet surface roughness than traditionally used laser profilometer. Both methods gave practically analogous results. It is finally suggested that the rapid 3D imaging can be a potential in-line PAT tool to predict mechanical properties of tablets in production.

  1. SA-based concrete seismic stress monitoring: a case study for normal strength concrete

    NASA Astrophysics Data System (ADS)

    Hou, S.; Zhang, H. B.; Ou, J. P.

    2016-09-01

    The stress history of concrete structures that have survived an earthquake can serve as a critical index to evaluate the health of the structure. There are currently few reliable monitoring methods to assess concrete stress after a seismic event. Piezoelectric-based smart aggregate (SA) provides an innovative experimental approach to monitor stress on concrete. The principle of SA-based concrete seismic stress monitoring is based on the assumption that concrete stress can be reliably predicted by the average output voltages of limited SAs with an acceptable margin of error. In this study, the meso-scale randomness of concrete was evaluated throughout the overall stress range of concrete and the influence of different load paths was considered. Four cylindrical specimens of normal strength concrete were embedded with a total of 24 SAs. The SA output sensitivity curve in the paths of loading-unloading with different amplitudes and monotonic loading up to failure was obtained. Monitoring errors were analyzed during pre- and post-peak stages from the experimental results. This research suggests that SA-based concrete seismic stress monitoring for normal strength concrete is reliable.

  2. Dielectric breakdown strength of magnetic nanofluid based on insulation oil after impulse test

    NASA Astrophysics Data System (ADS)

    Nazari, M.; Rasoulifard, M. H.; Hosseini, H.

    2016-02-01

    In this study, the dielectric breakdown strength of magnetic nanofluids based on transformer mineral oil for use in power systems is reviewed. Nano oil samples are obtained from dispersion of the magnetic nanofluid within uninhibited transformer mineral oil NYTRO LIBRA as the base fluid. AC dielectric breakdown voltage measurement was carried out according to IEC 60156 standard and the lightning impulse breakdown voltage was obtained by using the sphere-sphere electrodes in an experimental setup for nano oil in volume concentration of 0.1-0.6%. Results indicate improved AC and lightning impulse breakdown voltage of nano oil compared to the base oil. AC test was performed again after applying impulse current and result showed that nano oil unlike the base oil retains its dielectric properties. Increase the dielectric strength of the nano oil is mainly due to dielectric and magnetic properties of Fe3O4 nanoparticles that act as free electrons snapper, and reduce the rate of free electrons in the ionization process.

  3. SA-based concrete seismic stress monitoring: a case study for normal strength concrete

    NASA Astrophysics Data System (ADS)

    Hou, S.; Zhang, H. B.; Ou, J. P.

    2016-09-01

    The stress history of concrete structures that have survived an earthquake can serve as a critical index to evaluate the health of the structure. There are currently few reliable monitoring methods to assess concrete stress after a seismic event. Piezoelectric-based smart aggregate (SA) provides an innovative experimental approach to monitor stress on concrete. The principle of SA-based concrete seismic stress monitoring is based on the assumption that concrete stress can be reliably predicted by the average output voltages of limited SAs with an acceptable margin of error. In this study, the meso-scale randomness of concrete was evaluated throughout the overall stress range of concrete and the influence of different load paths was considered. Four cylindrical specimens of normal strength concrete were embedded with a total of 24 SAs. The SA output sensitivity curve in the paths of loading–unloading with different amplitudes and monotonic loading up to failure was obtained. Monitoring errors were analyzed during pre- and post-peak stages from the experimental results. This research suggests that SA-based concrete seismic stress monitoring for normal strength concrete is reliable.

  4. Experimental validation of DXA-based finite element models for prediction of femoral strength.

    PubMed

    Dall'Ara, E; Eastell, R; Viceconti, M; Pahr, D; Yang, L

    2016-10-01

    Osteoporotic fractures are a major clinical problem and current diagnostic tools have an accuracy of only 50%. The aim of this study was to validate dual energy X-rays absorptiometry (DXA)-based finite element (FE) models to predict femoral strength in two loading configurations. Thirty-six pairs of fresh frozen human proximal femora were scanned with DXA and quantitative computed tomography (QCT). For each pair one femur was tested until failure in a one-legged standing configuration (STANCE) and one by replicating the position of the femur in a fall onto the greater trochanter (SIDE). Subject-specific 2D DXA-based linear FE models and 3D QCT-based nonlinear FE models were generated for each specimen and used to predict the measured femoral strength. The outcomes of the models were compared to standard DXA-based areal bone mineral density (aBMD) measurements. For the STANCE configuration the DXA-based FE models (R(2)=0.74, SEE=1473N) outperformed the best densitometric predictor (Neck_aBMD, R(2)=0.66, SEE=1687N) but not the QCT-based FE models (R(2)=0.80, SEE=1314N). For the SIDE configuration both QCT-based FE models (R(2)=0.85, SEE=455N) and DXA neck aBMD (R(2)=0.80, SEE=502N) outperformed DXA-based FE models (R(2)=0.77, SEE=529N). In both configurations the DXA-based FE model provided a good 1:1 agreement with the experimental data (CC=0.87 for SIDE and CC=0.86 for STANCE), with proper optimization of the failure criteria. In conclusion we found that the DXA-based FE models are a good predictor of femoral strength as compared with experimental data ex vivo. However, it remains to be investigated whether this novel approach can provide good predictions of the risk of fracture in vivo. PMID:27341287

  5. The influence of nickel slag aggregate concentration to compressive and flexural strength on fly ash-based geopolymer composite

    NASA Astrophysics Data System (ADS)

    Sujiono, E. H.; Setiawan, A.; Husain, H.; Irhamsyah, A.; Samnur, S.; Subaer, S.

    2016-04-01

    Fly ash-based geopolymer with nickel slag aggregate has been successfully produced. Fly ash and nickel slag were obtained from Bosowa Jeneponto Power Plant and PT. Vale Indonesia, respectively. This research aims to investigate the influence of nickel slag concentration to compressive strength, flexural strength, and microstructure of geopolymer composite. The increment of nickel slag aggregate on fly ash was relative to the weight of samples. Geopolymer composite were synthesized by using alkali activated method, cured at temperature of 70 °C for 1 hour. The resulting composites were left at room temperature for 14 days, before compressive and flexural strength were performed. The results showed that the addition of nickel slag aggregate was found to increase the compressive strength of the material. The optimum compressive strength was 14.81 MPa with the addition of 10% aggregate. The optimum flexural strength was 2.63 MPa with the addition of 15% aggregate.

  6. Enzymatic surface erosion of high tensile strength polycarbonates based on natural phenols.

    PubMed

    Sommerfeld, Sven D; Zhang, Zheng; Costache, Marius C; Vega, Sebastián L; Kohn, Joachim

    2014-03-10

    Surface erosion has been recognized as a valuable design tool for resorbable biomaterials within the context of drug delivery devices, surface coatings, and when precise control of strength retention is critical. Here we report on high tensile strength, aromatic-aliphatic polycarbonates based on natural phenols, tyrosol (Ty) and homovanillyl alcohol (Hva), that exhibit enzymatic surface erosion by lipase. The Young's moduli of the polymers for dry and fully hydrated samples are 1.0 to 1.2 GPa and 0.8 to 1.2 GPa, respectively. Typical characteristics of enzymatic surface erosion were confirmed for poly(tyrosol carbonate) films with concomitant mass-loss and thickness-loss at linear rates of 0.14 ± 0.01 mg cm(-2) d(-1) and 3.0 ± 0.8 μm d(-1), respectively. The molecular weight and the mechanical properties of the residual films remained constant. Changing the ratio of Ty and Hva provided control over the glass transition temperature (T(g)) and the enzymatic surface erosion: increasing the Hva content in the polymers resulted in higher T(g) and lower enzymatic erosion rate. Polymers with more than 50 mol % Hva were stable at 37 °C in enzyme solution. Analysis on thin films using quartz crystal microbalance with dissipation (QCM-D) demonstrated that the onset temperature of the enzymatic erosion was approximately 20 °C lower than the wet T(g) for all tested polymers. This new finding demonstrates that relatively high tensile strength polycarbonates can undergo enzymatic surface erosion. Moreover, it also sheds light on the connection between T(g) and enzymatic degradation and explains why few of the high strength polymers follow an enzyme-meditated degradation pathway.

  7. Enzymatic Surface Erosion of High Tensile Strength Polycarbonates Based on Natural Phenols

    PubMed Central

    2015-01-01

    Surface erosion has been recognized as a valuable design tool for resorbable biomaterials within the context of drug delivery devices, surface coatings, and when precise control of strength retention is critical. Here we report on high tensile strength, aromatic–aliphatic polycarbonates based on natural phenols, tyrosol (Ty) and homovanillyl alcohol (Hva), that exhibit enzymatic surface erosion by lipase. The Young’s moduli of the polymers for dry and fully hydrated samples are 1.0 to 1.2 GPa and 0.8 to 1.2 GPa, respectively. Typical characteristics of enzymatic surface erosion were confirmed for poly(tyrosol carbonate) films with concomitant mass-loss and thickness-loss at linear rates of 0.14 ± 0.01 mg cm–2 d–1 and 3.0 ± 0.8 μm d–1, respectively. The molecular weight and the mechanical properties of the residual films remained constant. Changing the ratio of Ty and Hva provided control over the glass transition temperature (Tg) and the enzymatic surface erosion: increasing the Hva content in the polymers resulted in higher Tg and lower enzymatic erosion rate. Polymers with more than 50 mol % Hva were stable at 37 °C in enzyme solution. Analysis on thin films using quartz crystal microbalance with dissipation (QCM-D) demonstrated that the onset temperature of the enzymatic erosion was approximately 20 °C lower than the wet Tg for all tested polymers. This new finding demonstrates that relatively high tensile strength polycarbonates can undergo enzymatic surface erosion. Moreover, it also sheds light on the connection between Tg and enzymatic degradation and explains why few of the high strength polymers follow an enzyme-meditated degradation pathway. PMID:24432806

  8. Strengths-Based Approaches in College and University Student Housing: Implications for First-Year Students' Retention and Engagement

    ERIC Educational Resources Information Center

    Soria, Krista M.; Taylor, Leonard, Jr.

    2016-01-01

    Strengths-based approaches are expanding in higher education; however, little is known about the impacts of these approaches in housing and residence life settings. The purpose of this study was to examine the associations between first-year students' strengths interactions in housing and their engagement and retention. The results suggest that…

  9. Well-Being on Campus: Testing the Effectiveness of an Online Strengths-Based Intervention for First Year College Students

    ERIC Educational Resources Information Center

    Koydemir, Selda; Sun-Selisik, Z. Eda

    2016-01-01

    The present research examined the effectiveness of an 8-week online strengths-based intervention in promoting subjective and psychological well-being of first year university students. The intervention was composed of five modules pertaining to (a) finding and cultivating on character strengths, (b) regulation of emotions and increasing positive…

  10. Role Strain and Adaptation Issues in the Strength-Based Model: Diversity, Multilevel, and Life-Span Considerations

    ERIC Educational Resources Information Center

    Bowman, Phillip J.

    2006-01-01

    This article applauds the strength-based model (SBM) of counseling but calls for an extension. In the existential or humanistic tradition, the SBM builds on emerging trends in psychology to highlight the importance of individual strengths in counseling interventions. However, a role strain and adaptation (RSA) approach extends the SBM to…

  11. Hedgehog Signaling Strength Is Orchestrated by the mir-310 Cluster of MicroRNAs in Response to Diet

    PubMed Central

    Çiçek, Ibrahim Ömer; Karaca, Samir; Brankatschk, Marko; Eaton, Suzanne; Urlaub, Henning; Shcherbata, Halyna R.

    2016-01-01

    Since the discovery of microRNAs (miRNAs) only two decades ago, they have emerged as an essential component of the gene regulatory machinery. miRNAs have seemingly paradoxical features: a single miRNA is able to simultaneously target hundreds of genes, while its presence is mostly dispensable for animal viability under normal conditions. It is known that miRNAs act as stress response factors; however, it remains challenging to determine their relevant targets and the conditions under which they function. To address this challenge, we propose a new workflow for miRNA function analysis, by which we found that the evolutionarily young miRNA family, the mir-310s (mir-310/mir-311/mir-312/mir-313), are important regulators of Drosophila metabolic status. mir-310s-deficient animals have an abnormal diet-dependent expression profile for numerous diet-sensitive components, accumulate fats, and show various physiological defects. We found that the mir-310s simultaneously repress the production of several regulatory factors (Rab23, DHR96, and Ttk) of the evolutionarily conserved Hedgehog (Hh) pathway to sharpen dietary response. As the mir-310s expression is highly dynamic and nutrition sensitive, this signal relay model helps to explain the molecular mechanism governing quick and robust Hh signaling responses to nutritional changes. Additionally, we discovered a new component of the Hh signaling pathway in Drosophila, Rab23, which cell autonomously regulates Hh ligand trafficking in the germline stem cell niche. How organisms adjust to dietary fluctuations to sustain healthy homeostasis is an intriguing research topic. These data are the first to report that miRNAs can act as executives that transduce nutritional signals to an essential signaling pathway. This suggests miRNAs as plausible therapeutic agents that can be used in combination with low calorie and cholesterol diets to manage quick and precise tissue-specific responses to nutritional changes. PMID:26801178

  12. Endogenous Rho-kinase signaling maintains synaptic strength by stabilizing the size of the readily releasable pool of synaptic vesicles.

    PubMed

    González-Forero, David; Montero, Fernando; García-Morales, Victoria; Domínguez, Germán; Gómez-Pérez, Laura; García-Verdugo, José Manuel; Moreno-López, Bernardo

    2012-01-01

    Rho-associated kinase (ROCK) regulates neural cell migration, proliferation and survival, dendritic spine morphology, and axon guidance and regeneration. There is, however, little information about whether ROCK modulates the electrical activity and information processing of neuronal circuits. At neonatal stage, ROCKα is expressed in hypoglossal motoneurons (HMNs) and in their afferent inputs, whereas ROCKβ is found in synaptic terminals on HMNs, but not in their somata. Inhibition of endogenous ROCK activity in neonatal rat brainstem slices failed to modulate intrinsic excitability of HMNs, but strongly attenuated the strength of their glutamatergic and GABAergic synaptic inputs. The mechanism acts presynaptically to reduce evoked neurotransmitter release. ROCK inhibition increased myosin light chain (MLC) phosphorylation, which is known to trigger actomyosin contraction, and reduced the number of synaptic vesicles docked to active zones in excitatory boutons. Functional and ultrastructural changes induced by ROCK inhibition were fully prevented/reverted by MLC kinase (MLCK) inhibition. Furthermore, ROCK inhibition drastically reduced the phosphorylated form of p21-associated kinase (PAK), which directly inhibits MLCK. We conclude that endogenous ROCK activity is necessary for the normal performance of motor output commands, because it maintains afferent synaptic strength, by stabilizing the size of the readily releasable pool of synaptic vesicles. The mechanism of action involves a tonic inhibition of MLCK, presumably through PAK phosphorylation. This mechanism might be present in adults since unilateral microinjection of ROCK or MLCK inhibitors into the hypoglossal nucleus reduced or increased, respectively, whole XIIth nerve activity.

  13. Fabric circuit board-based dry electrode and its characteristics for long-term physiological signal recording.

    PubMed

    Yoo, Jerald; Yoo, Hoi-Jun

    2011-01-01

    This paper presents a dry fabric electrode and its characteristics. For long-term physiological signal monitoring, conventional wet type electrode such as an Ag/AgCl electrode may not be sufficient, because captured signal strength degrades over time as its electrolyte dehydrates. Moreover, the electrolyte may cause skin irritation over a period of time. As a complement, a dry electrode can be used. In this work, fabric-based dry electrodes are introduced. Planar-Fabric Circuit Board (P-FCB) technology enables low cost and uniform productions of such electrodes; electrical properties of the electrodes with various materials, sizes, and time are shown. Both the strengths and drawbacks of the fabric-based electrodes are also discussed.

  14. SoC-based architecture for biomedical signal processing.

    PubMed

    Gutiérrez-Rivas, R; Hernández, A; García, J J; Marnane, W

    2015-01-01

    Over the last decades, many algorithms have been proposed for processing biomedical signals. Most of these algorithms have been focused on the elimination of noise and artifacts existing in these signals, so they can be used for automatic monitoring and/or diagnosis applications. With regard to remote monitoring, the use of portable devices often requires a reduced number of resources and power consumption, being necessary to reach a trade-off between the accuracy of algorithms and their computational complexity. This paper presents a SoC (System-on-Chip) architecture, based on a FPGA (Field-Programmable Gate Array) device, suitable for the implementation of biomedical signal processing. The proposal has been successfully validated by implementing an efficient QRS complex detector. The results show that, using a reduced amount of resources, values of sensitivity and positive predictive value above 99.49% are achieved, which make the proposed approach suitable for telemedicine applications.

  15. Evolution of the Calcium-Based Intracellular Signaling System

    PubMed Central

    Marchadier, Elodie; Oates, Matt E.; Fang, Hai; Donoghue, Philip C.J.; Hetherington, Alistair M.; Gough, Julian

    2016-01-01

    To progress our understanding of molecular evolution from a collection of well-studied genes toward the level of the cell, we must consider whole systems. Here, we reveal the evolution of an important intracellular signaling system. The calcium-signaling toolkit is made up of different multidomain proteins that have undergone duplication, recombination, sequence divergence, and selection. The picture of evolution, considering the repertoire of proteins in the toolkit of both extant organisms and ancestors, is radically different from that of other systems. In eukaryotes, the repertoire increased in both abundance and diversity at a far greater rate than general genomic expansion. We describe how calcium-based intracellular signaling evolution differs not only in rate but in nature, and how this correlates with the disparity of plants and animals. PMID:27358427

  16. SoC-based architecture for biomedical signal processing.

    PubMed

    Gutiérrez-Rivas, R; Hernández, A; García, J J; Marnane, W

    2015-01-01

    Over the last decades, many algorithms have been proposed for processing biomedical signals. Most of these algorithms have been focused on the elimination of noise and artifacts existing in these signals, so they can be used for automatic monitoring and/or diagnosis applications. With regard to remote monitoring, the use of portable devices often requires a reduced number of resources and power consumption, being necessary to reach a trade-off between the accuracy of algorithms and their computational complexity. This paper presents a SoC (System-on-Chip) architecture, based on a FPGA (Field-Programmable Gate Array) device, suitable for the implementation of biomedical signal processing. The proposal has been successfully validated by implementing an efficient QRS complex detector. The results show that, using a reduced amount of resources, values of sensitivity and positive predictive value above 99.49% are achieved, which make the proposed approach suitable for telemedicine applications. PMID:26737663

  17. Dissimilarity measure based on ordinal pattern for physiological signals

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Shang, Pengjian; Shi, Wenbin; Cui, Xingran

    2016-08-01

    Complex physiologic signals may carry information of their underlying mechanisms. In this paper, we introduce a dissimilarity measure to capture the features of underlying dynamics from various types of physiologic signals based on rank order statistics of ordinal patterns. Simulated 1/f noise and white noise are used to evaluate the effect of data length, embedding dimension and time delay on this measure. We then apply this measure to different physiologic signals. The method can successfully characterize the unique underlying patterns of subjects at similar physiologic states. It can also serve as a good discriminative tool for the healthy young, healthy elderly, congestive heart failure, atrial fibrilation and white noise groups. Furthermore, when investigated into the details of underlying ordinal patterns for each group, it is found that the distributions of ordinal patterns varies significantly for healthy and pathologic states, as well as aging.

  18. The physiology of membrane transport and endomembrane-based signalling

    PubMed Central

    Sallese, Michele; Pulvirenti, Teodoro; Luini, Alberto

    2006-01-01

    Some of the important open questions concerning the physiology of the secretory pathway relate to its homeostasis. Secretion involves a number of separate compartments for which their transport activities should be precisely cross-coordinated to avoid gross imbalances in the trafficking system. Moreover, the membrane fluxes across these compartments should be able to adapt to environmental ‘requests' and to respond to extracellular signals. How is this regulation effected? Here, we consider evidence that endomembrane-based signalling cascades that are similar in organization to those used at the plasma membrane coordinate membrane traffic. If this is the case, this would also represent a model for a more general inter-organelle signalling network for functionally interconnecting different intracellular activities, a necessity for the maintenance of cellular homeostasis and to express harmonic global cellular responses. PMID:16763561

  19. The resistance of selected high strength alloys to embrittlement by a hydrogen environment. [iron and cobalt base alloys

    NASA Technical Reports Server (NTRS)

    Benson, R. B., Jr.

    1974-01-01

    Selected high strength iron base and cobalt base alloys were resistant to degradation of mechanical properties in a one atmosphere hydrogen environment at ambient temperature. These alloys were strengthened initially by cold working which produced strain induced martensite and fcc mechanical twins in an fcc matrix. Heat treatment of the cobalt base alloy after cold working produced carbide precipitates with retention of an hcp epsilon phase which increased the yield strength level. High strength alloys can be produced which have some resistance to degradation of mechanical properties by a hydrogen environment under certain conditions.

  20. FEAMAC-CARES Software Coupling Development Effort for CMC Stochastic-Strength-Based Damage Simulation

    NASA Technical Reports Server (NTRS)

    Nemeth, Noel N.; Bednarcyk, Brett A.; Pineda, Evan; Arnold, Steven; Mital, Subodh; Murthy, Pappu; Walton, Owen

    2015-01-01

    Reported here is a coupling of two NASA developed codes: CARES (Ceramics Analysis and Reliability Evaluation of Structures) with the MACGMC composite material analysis code. The resulting code is called FEAMACCARES and is constructed as an Abaqus finite element analysis UMAT (user defined material). Here we describe the FEAMACCARES code and an example problem (taken from the open literature) of a laminated CMC in off-axis loading is shown. FEAMACCARES performs stochastic-strength-based damage simulation response of a CMC under multiaxial loading using elastic stiffness reduction of the failed elements.

  1. FEAMAC/CARES Stochastic-Strength-Based Damage Simulation Tool for Ceramic Matrix Composites

    NASA Technical Reports Server (NTRS)

    Nemeth, Noel; Bednarcyk, Brett; Pineda, Evan; Arnold, Steven; Mital, Subodh; Murthy, Pappu; Bhatt, Ramakrishna

    2016-01-01

    Reported here is a coupling of two NASA developed codes: CARES (Ceramics Analysis and Reliability Evaluation of Structures) with the MAC/GMC (Micromechanics Analysis Code/ Generalized Method of Cells) composite material analysis code. The resulting code is called FEAMAC/CARES and is constructed as an Abaqus finite element analysis UMAT (user defined material). Here we describe the FEAMAC/CARES code and an example problem (taken from the open literature) of a laminated CMC in off-axis loading is shown. FEAMAC/CARES performs stochastic-strength-based damage simulation response of a CMC under multiaxial loading using elastic stiffness reduction of the failed elements.

  2. Strength and corrosion behavior of SiC - based ceramics in hot coal combustion environments

    SciTech Connect

    Breder, K.; Parten, R.J.

    1996-08-01

    As part of an effort to evaluate the use of advanced ceramics in a new generation of coal-fired power plants, four SiC-based ceramics have been exposed to corrosive coal slag in a laboratory furnace and two pilot scale combustors. Initial results indicate that the laboratory experiments are valuable additions to more expensive pilot plant experiments. The results show increased corrosive attack with increased temperature, and that only slight changes in temperature may significantly alter the degree of strength degradation due to corrosive attack. The present results are part of a larger experimental matrix evaluating the behavior of ceramics in the coal combustion environment.

  3. Strength Characteristics of Resorbable Osteoconductive Ceramics Based on Diphosphates of Calcium and Alkali Metals

    NASA Astrophysics Data System (ADS)

    Putlayev, V. I.; Evdokimov, P. V.; Garshev, A. V.; Prosvirin, D. V.; Klimashina, E. S.; Safronova, T. V.; Ivanov, V. K.

    2014-02-01

    An investigation into the strength characteristics of ceramics based on diphosphates Ca(3- x)М2 x (PO4)2 ( x = 0-1 and М = Na, K) provides evidence of composition strengthening in the range х = 0.6-0.8 containing the greatest amount of the supercooled high-temperature modification α-СаМРО4. The method of high-temperature x-ray diffractometry is used to examine thermal expansion of rhenanite phases of СаМРО4.

  4. A strong integrated strength and toughness artificial nacre based on dopamine cross-linked graphene oxide.

    PubMed

    Cui, Wei; Li, Mingzhu; Liu, Jiyang; Wang, Ben; Zhang, Chuck; Jiang, Lei; Cheng, Qunfeng

    2014-09-23

    Demands of the strong integrated materials have substantially increased across various industries. Inspired by the relationship of excellent integration of mechanical properties and hierarchical nano/microscale structure of the natural nacre, we have developed a strategy for fabricating the strong integrated artificial nacre based on graphene oxide (GO) sheets by dopamine cross-linking via evaporation-induced assembly process. The tensile strength and toughness simultaneously show 1.5 and 2 times higher than that of natural nacre. Meanwhile, the artificial nacre shows high electrical conductivity. This type of strong integrated artificial nacre has great potential applications in aerospace, flexible supercapacitor electrodes, artificial muscle, and tissue engineering. PMID:25106494

  5. Shock Induced Shear Strength in Two HMX Based Polymer Bonded Explosives

    NASA Astrophysics Data System (ADS)

    Millett, Jeremy; Taylor, Peter; Appleby-Thomas, Gareth

    2015-06-01

    The response of energetic materials to shock loading has largely concentrated on their detonation behaviour. However, they can also be considered to be structural materials in their own right, and hence their response to a purely mechanical shock loading is also of interest. Therefore we present results from two HMX based polymer bonded explosives, EDC37 and EDC32, where we investigate the shock induced shear strength behind the shock front. Results are discussed in terms of microstructure and differences of the binder phases.

  6. Biomolecular Simulation of Base Excision Repair and Protein Signaling

    SciTech Connect

    Straatsma, TP; McCammon, J A; Miller, John H; Smith, Paul E; Vorpagel, Erich R; Wong, Chung F; Zacharias, Martin W

    2006-03-03

    The goal of the Biomolecular Simulation of Base Excision Repair and Protein Signaling project is to enhance our understanding of the mechanism of human polymerase-β, one of the key enzymes in base excision repair (BER) and the cell-signaling enzymes cyclic-AMP-dependent protein kinase. This work used molecular modeling and simulation studies to specifically focus on the • dynamics of DNA and damaged DNA • dynamics and energetics of base flipping in DNA • mechanism and fidelity of nucleotide insertion by BER enzyme human polymerase-β • mechanism and inhibitor design for cyclic-AMP-dependent protein kinase. Molecular dynamics simulations and electronic structure calculations have been performed using the computer resources at the Molecular Science Computing Facility at the Environmental Molecular Sciences Laboratory.

  7. Effects of fat on MR-measured metabolite signal strengths: implications for in vivo MRS studies of the human brain.

    PubMed

    Mon, Anderson; Abé, Christoph; Durazzo, Timothy C; Meyerhoff, Dieter J

    2013-12-01

    Recent MRS studies have indicated that a higher body mass index (BMI) is associated with lower brain metabolite levels. Generally, individuals with higher BMIs have more body fat deposits than individuals with normal BMIs. This single-voxel spectroscopy (SVS) study investigated possible effects of fat on MR-measured metabolite signal areas, which may at least partly explain the observed associations of BMI with MR-measured brain metabolite levels in vivo. SVS data were acquired at 4 T from a phantom containing N-acetylaspartate, glutamate and creatine, as well as from three healthy male adults. Back fat obtained from pig was used to assess the effects of fat on metabolite signals. With the same voxel size and placement, the phantom was first scanned without fat (baseline), and then with 0.7-cm- and 1.4-cm-thick fat layers placed on it. Each participant was also scanned first without fat and then with two 0.7-cm fat layers, one placed beneath the occiput and the other on the forehead. Two spectra were acquired per participant from the anterior cingulate and the parieto-occipital cortices. The metabolite resonance and corresponding water peak areas were then fitted and metabolite to water signal ratios were used for analyses. In both phantom and in vivo experiments, the metabolite-to-water ratios decreased in the presence of fat relative to baseline metabolite-to-water ratios. The reduced metabolite signals in the presence of fat reported here are reminiscent of the negative correlations observed between BMI and MR-measured metabolite levels. These apparent physical effects of fat have potentially far-reaching consequences for the accuracy of MR measurements of brain metabolite levels and their interpretation, particularly when large fat stores exist around the skull, such as in individuals with higher BMI.

  8. Pilot Signal Design for Massive MIMO Systems: A Received Signal-To-Noise-Ratio-Based Approach

    NASA Astrophysics Data System (ADS)

    So, Jungho; Kim, Donggun; Lee, Yuni; Sung, Youngchul

    2015-05-01

    In this paper, the pilot signal design for massive MIMO systems to maximize the training-based received signal-to-noise ratio (SNR) is considered under two channel models: block Gauss-Markov and block independent and identically distributed (i.i.d.) channel models. First, it is shown that under the block Gauss-Markov channel model, the optimal pilot design problem reduces to a semi-definite programming (SDP) problem, which can be solved numerically by a standard convex optimization tool. Second, under the block i.i.d. channel model, an optimal solution is obtained in closed form. Numerical results show that the proposed method yields noticeably better performance than other existing pilot design methods in terms of received SNR.

  9. Leveraging Strengths Assessment and Intervention Model (LeStAIM): A Theoretical Strength-Based Assessment Framework

    ERIC Educational Resources Information Center

    Laija-Rodriguez, Wilda; Grites, Karen; Bouman, Doug; Pohlman, Craig; Goldman, Richard L.

    2013-01-01

    Current assessments in the schools are based on a deficit model (Epstein, 1998). "The National Association of School Psychologists (NASP) Model for Comprehensive and Integrated School Psychological Services" (2010), federal initiatives and mandates, and experts in the field of assessment have highlighted the need for the comprehensive…

  10. Strengths and weaknesses of Problem Based Learning from the professional perspective of registered nurses 1

    PubMed Central

    Cónsul-Giribet, María; Medina-Moya, José Luis

    2014-01-01

    OBJECTIVE: to identify competency strengths and weaknesses as perceived by nursing professionals who graduated with a integrated curriculum and competency-based through Problem Based Learning in small groups. METHOD: an intrinsic case study method was used, which analyzes this innovation through former students (from the first class) with three years of professional experience. The data were collected through a questionnaire and discussion groups. RESULTS: the results show that their competency level is valued in a very satisfactory manner. This level paradoxically contrasts with the lack of theoretical knowledge they perceived at the end of their education, when they started working in clinical practice. CONCLUSIONS: the teaching strategy was key to motivate an in-depth study and arouse the desire to know. In addition, Problem Based Learning favors and reinforces the decision to learn, which is that necessary in the course of professional life. PMID:25493666

  11. AIRS Observations Based Evaluation of Relative Climate Feedback Strengths on a GCM Grid-Scale

    NASA Astrophysics Data System (ADS)

    Molnar, G. I.; Susskind, J.

    2012-12-01

    Climate feedback strengths, especially those associated with moist processes, still have a rather wide range in GCMs, the primary tools to predict future climate changes associated with man's ever increasing influences on our planet. Here, we make use of the first 10 years of AIRS observations to evaluate interrelationships/correlations of atmospheric moist parameter anomalies computed from AIRS Version 5 Level-3 products, and demonstrate their usefulness to assess relative feedback strengths. Although one may argue about the possible usability of shorter-term, observed climate parameter anomalies for estimating the strength of various (mostly moist processes related) feedbacks, recent works, in particular analyses by Dessler [2008, 2010], have demonstrated their usefulness in assessing global water vapor and cloud feedbacks. First, we create AIRS-observed monthly anomaly time-series (ATs) of outgoing longwave radiation, water vapor, clouds and temperature profile over a 10-year long (Sept. 2002 through Aug. 2012) period using 1x1 degree resolution (a common GCM grid-scale). Next, we evaluate the interrelationships of ATs of the above parameters with the corresponding 1x1 degree, as well as global surface temperature ATs. The latter provides insight comparable with more traditional climate feedback definitions (e. g., Zelinka and Hartmann, 2012) whilst the former is related to a new definition of "local (in surface temperature too) feedback strengths" on a GCM grid-scale. Comparing the correlation maps generated provides valuable new information on the spatial distribution of relative climate feedback strengths. We argue that for GCMs to be trusted for predicting longer-term climate variability, they should be able to reproduce these observed relationships/metrics as closely as possible. For this time period the main climate "forcing" was associated with the El Niño/La Niña variability (e. g., Dessler, 2010), so these assessments may not be descriptive of longer

  12. A MUSIC-based method for SSVEP signal processing.

    PubMed

    Chen, Kun; Liu, Quan; Ai, Qingsong; Zhou, Zude; Xie, Sheng Quan; Meng, Wei

    2016-03-01

    The research on brain computer interfaces (BCIs) has become a hotspot in recent years because it offers benefit to disabled people to communicate with the outside world. Steady state visual evoked potential (SSVEP)-based BCIs are more widely used because of higher signal to noise ratio and greater information transfer rate compared with other BCI techniques. In this paper, a multiple signal classification based method was proposed for multi-dimensional SSVEP feature extraction. 2-second data epochs from four electrodes achieved excellent accuracy rates including idle state detection. In some asynchronous mode experiments, the recognition accuracy reached up to 100%. The experimental results showed that the proposed method attained good frequency resolution. In most situations, the recognition accuracy was higher than canonical correlation analysis, which is a typical method for multi-channel SSVEP signal processing. Also, a virtual keyboard was successfully controlled by different subjects in an unshielded environment, which proved the feasibility of the proposed method for multi-dimensional SSVEP signal processing in practical applications.

  13. An emerging paradigm: a strength-based approach to exploring mental imagery

    PubMed Central

    MacIntyre, Tadhg E.; Moran, Aidan P.; Collet, Christian; Guillot, Aymeric

    2013-01-01

    Mental imagery, or the ability to simulate in the mind information that is not currently perceived by the senses, has attracted considerable research interest in psychology since the early 1970's. Within the past two decades, research in this field—as in cognitive psychology more generally—has been dominated by neuroscientific methods that typically involve comparisons between imagery performance of participants from clinical populations with those who exhibit apparently normal cognitive functioning. Although this approach has been valuable in identifying key neural substrates of visual imagery, it has been less successful in understanding the possible mechanisms underlying another simulation process, namely, motor imagery or the mental rehearsal of actions without engaging in the actual movements involved. In order to address this oversight, a “strength-based” approach has been postulated which is concerned with understanding those on the high ability end of the imagery performance spectrum. Guided by the expert performance approach and principles of ecological validity, converging methods have the potential to enable imagery researchers to investigate the neural “signature” of elite performers, for example. Therefore, the purpose of this paper is to explain the origin, nature, and implications of the strength-based approach to mental imagery. Following a brief explanation of the background to this latter approach, we highlight some important theoretical advances yielded by recent research on mental practice, mental travel, and meta-imagery processes in expert athletes and dancers. Next, we consider the methodological implications of using a strength-based approach to investigate imagery processes. The implications for the field of motor cognition are outlined and specific research questions, in dynamic imagery, imagery perspective, measurement, multi-sensory imagery, and metacognition that may benefit from this approach in the future are sketched

  14. Chaos based encryption system for encrypting electroencephalogram signals.

    PubMed

    Lin, Chin-Feng; Shih, Shun-Han; Zhu, Jin-De

    2014-05-01

    In the paper, we use the Microsoft Visual Studio Development Kit and C# programming language to implement a chaos-based electroencephalogram (EEG) encryption system involving three encryption levels. A chaos logic map, initial value, and bifurcation parameter for the map were used to generate Level I chaos-based EEG encryption bit streams. Two encryption-level parameters were added to these elements to generate Level II chaos-based EEG encryption bit streams. An additional chaotic map and chaotic address index assignment process was used to implement the Level III chaos-based EEG encryption system. Eight 16-channel EEG Vue signals were tested using the encryption system. The encryption was the most rapid and robust in the Level III system. The test yielded superior encryption results, and when the correct deciphering parameter was applied, the EEG signals were completely recovered. However, an input parameter error (e.g., a 0.00001 % initial point error) causes chaotic encryption bit streams, preventing the recovery of 16-channel EEG Vue signals.

  15. High melt strength, tear resistant blown film based on poly(lactic acid)

    NASA Astrophysics Data System (ADS)

    Edmonds, Neil R.; Plimmer, Peter N.; Tanner, Chris

    2015-05-01

    A major problem associated with the commercial manufacture of thin films from PLA is inferior processing characteristics on blown film lines compared to low density polyethylene. PLA has poor melt strength (leading to bubble instability) and develops a permanent crease in the flattened film as it exits the tower of the film line. In addition, the thin film product has poor tear strength and an unacceptable `noise' level when converted into flexible packaging. Furthermore, fabricated articles based on PLA are known to show an unattractive tendency toward dimensional instability. This behaviour is associated with `cold crystallization', a phenomenon which also causes exudation of any plasticizer added for improving flexibility. Blow moulded articles based on PLA also exhibit dimensional sensitivity above 60°C. All of these issues have been overcome by the technology described in this paper. This has been accomplished without loss of the valuable compostability characteristic of PLA; this was confirmed by evaluation of film in a commercial composting operation. These results have been achieved through novel reactive compounding technology which: (a) Creates a PLA-rich structure containing long chain crosslinks, (b) generates a low glass transition temperature phase covalently bonded to the PLA structure, and (c) provides a material which performs like LDPE in a blown film manufacturing operation. The technology developed is covered by NZ Patent 580231 (3). The patent is held by UniServices Ltd, The University of Auckland, New Zealand.

  16. Age and response bias: evidence from the strength-based mirror effect.

    PubMed

    Criss, Amy H; Aue, William; Kılıç, Aslı

    2014-10-01

    Performance in episodic memory is determined both by accurate retrieval from memory and by decision processes. A substantial body of literature suggests slightly poorer episodic memory accuracy for older than younger adults; however, age-related changes in the decision mechanisms in memory have received much less attention. Response bias, the willingness to endorse an item as remembered, is an important decision factor that contributes to episodic memory performance, and therefore understanding age-related changes in response bias is critical to theoretical development. We manipulate list strength in order to investigate two aspects of response bias. First, we evaluate whether criterion placement in episodic memory differs for older and younger adults. Second, we ask whether older adults have the same degree of flexibility to adjust the criterion in response to task demands as younger adults. Participants were tested on weakly and strongly encoded lists where word frequency (Experiment 1) or similarity between targets and foils (Experiment 2) was manipulated. Both older and younger adults had higher hit rates and lower false-alarm rates for strong lists than for weak lists (i.e., a strength-based mirror effect). Older adults were more conservative (less likely to endorse an item as studied) than younger adults, and we found no evidence that older and younger adults differ in their ability to flexibly adjust their criterion based on the demands of the task.

  17. Effect of plastic anisotropy on tensile strength of single crystals of an Ni-based superalloy

    SciTech Connect

    Kakehi, K.

    1999-12-31

    Turbine blades are designed so that their primary orientation is within 10 to 15{degree} of the <001> axis to insure a low modulus. The secondary dendritic direction (<010> direction) is usually randomly orientated with respect to the longitudinal direction of the turbine blade. The strengths of single crystals are influenced by the crystallographic orientations not only in the tensile direction but also in the normal direction of the specimen because a single crystal possesses intrinsic plastic anisotropy. The air-cooled turbine blades, which have a complicated hollow structure, are composed of sections of various thicknesses. Therefore, the mechanical properties of each blade section will depend on plastic anisotropy and the stress state as well as stress in the longitudinal direction. In previous studies, in an experimental single crystal alloy of an Ni-based superalloy, it has been revealed that {l_brace}111{r_brace}<101>-type slip systems were activated during tensile tests. In this study, by using the experimental alloy which shows distinct active slip systems, the influence of crystallographic orientations and plastic anisotropy on the strength and ductility of single crystals of the Ni-based superalloy have been investigated on the assumption that the {l_brace}111{r_brace}<101> slip systems operate.

  18. In-depth Evaluation of Content-Based Phishing Detection to Clarify Its Strengths and Limitations

    NASA Astrophysics Data System (ADS)

    Komiyama, Koichiro; Seko, Toshinori; Ichinose, Yusuke; Kato, Kei; Kawano, Kohei; Yoshiura, Hiroshi

    Zhang et al. proposed a method for content-based phishing detection (CBD) and reported its high performance in detecting phishing sites written in English. However, the evaluations of the CBD method performed by Zhang et al. and others were small-scale and simply measured the detection and error rates, i.e, they did not analyze the causes of the detection errors. Moreover, the effectiveness of the CBD method with non-English sites, such as Japanese and Chinese language sites, has never been tested. This paper reports our in-depth evaluation and analysis of the CBD method using 843 actual phishing sites (including 475 English and 368 Japanese sites), and explains both the strengths of the CBD method and its limitations. Our work provides a base for using the CBD method in the real world.

  19. Flexural Strength Comparison of Silorane- and Methacrylate-Based Composites with Pre-impregnated Glass Fiber

    PubMed Central

    Doozandeh, Maryam; Alavi, Ali Asghar; Karimizadeh, Zahra

    2016-01-01

    Statement of the Problem Sufficient adhesion between silorane/methacrylate-based composites and methacrylate impregnated glass fiber increases the benefits of fibers and enhances the mechanical and clinical performance of both composites. Purpose The aim of this study was to evaluate the compatibility of silorane and methacrylate-based composites with pre-impregnated glass fiber by using flexural strength (FS) test. Materials and Method A total of 60 bar specimens were prepared in a split mold (25×2×2 mm) in 6 groups (n=10). In groups 1 and 4 (control), silorane-based (Filtek P90) and nanohybrid (Filtek Z350) composites were placed into the mold and photopolymerized with a high-intensity curing unit. In groups 2 and 5, pre-impregnated glass fiber was first placed into the mold and after two minutes of curing, the mold was filled with respective composites. Prior to filling the mold in groups 3 and 6, an intermediate adhesive layer was applied to the glass fiber. The specimens were stored in distilled water for 24 hours and then their flexural strength was measured by 3 point bending test, using universal testing machine at the crosshead speed of 1 mm/min. Two-way ANOVA and post-hoc test were used for analyzing the data (p< 0.05). Results A significant difference was observed between the groups (p< 0.05). The highest FS was registered for combination of Z350 composite, impregnated glass fiber, and application of intermediate adhesive layer .The lowest FS was obtained in Filtek P90 alone. Cohesive failure in composite was the predominant failure in all groups, except group 5 in which adhesive failure between the composite and fiber was exclusively observed. Conclusion Significant improvement in FS was achieved for both composites with glass fiber. Additional application of intermediate adhesive layer before composite build up seems to increase FS. Nanohybrid composite showed higher FS than silorane-based composite. PMID:27284555

  20. A Comparison of Shear Bond Strength of Ceramic and Resin Denture Teeth on Different Acrylic Resin Bases

    PubMed Central

    Corsalini, Massimo; Venere, Daniela Di; Pettini, Francesco; Stefanachi, Gianluca; Catapano, Santo; Boccaccio, Antonio; Lamberti, Luciano; Pappalettere, Carmine; Carossa, Stefano

    2014-01-01

    The purpose of this study is to compare the shear bond strength of different resin bases and artificial teeth made of ceramic or acrylic resin materials and whether tooth-base interface may be treated with aluminium oxide sandblasting. Experimental measurements were carried on 80 specimens consisting of a cylinder of acrylic resin into which a single tooth is inserted. An ad hoc metallic frame was realized to measure the shear bond strength at the tooth-base interface. A complete factorial plan was designed and a three-way ANalysis Of VAriance (ANOVA) was carried out to investigate if shear bond strength is affected by the following factors: (i) tooth material (ceramic or resin); (ii) base material (self-curing or thermal-curing resin); (iii) presence or absence of aluminium oxide sandblasting treatment at the tooth-base interface. Tukey post hoc test was also conducted to evaluate any statistically significant difference between shear strength values measured for the dif-ferently prepared samples. It was found from ANOVA that the above mentioned factors all affect shear strength. Furthermore, post hoc analysis indi-cated that there are statistically significant differences (p-value=0.000) between measured shear strength values for: (i) teeth made of ceramic material vs. teeth made of acrylic resin material; (ii) bases made of self-curing resin vs. thermal-curing resin; (iii) specimens treated with aluminium oxide sandblasting vs. untreated specimens. Shear strength values measured for acryl-ic resin teeth were on average 70% higher than those measured for ceramic teeth. The shear bond strength was maximized by preparing samples with thermal-curing resin bases and resin teeth submitted to aluminium oxide sandblasting. PMID:25614770

  1. A comparison of shear bond strength of ceramic and resin denture teeth on different acrylic resin bases.

    PubMed

    Corsalini, Massimo; Di Venere, Daniela; Pettini, Francesco; Stefanachi, Gianluca; Catapano, Santo; Boccaccio, Antonio; Lamberti, Luciano; Pappalettere, Carmine; Carossa, Stefano

    2014-01-01

    The purpose of this study is to compare the shear bond strength of different resin bases and artificial teeth made of ceramic or acrylic resin materials and whether tooth-base interface may be treated with aluminium oxide sandblasting. Experimental measurements were carried on 80 specimens consisting of a cylinder of acrylic resin into which a single tooth is inserted. An ad hoc metallic frame was realized to measure the shear bond strength at the tooth-base interface. A complete factorial plan was designed and a three-way ANalysis Of VAriance (ANOVA) was carried out to investigate if shear bond strength is affected by the following factors: (i) tooth material (ceramic or resin); (ii) base material (self-curing or thermal-curing resin); (iii) presence or absence of aluminium oxide sandblasting treatment at the tooth-base interface. Tukey post hoc test was also conducted to evaluate any statistically significant difference between shear strength values measured for the dif-ferently prepared samples. It was found from ANOVA that the above mentioned factors all affect shear strength. Furthermore, post hoc analysis indi-cated that there are statistically significant differences (p-value=0.000) between measured shear strength values for: (i) teeth made of ceramic material vs. teeth made of acrylic resin material; (ii) bases made of self-curing resin vs. thermal-curing resin; (iii) specimens treated with aluminium oxide sandblasting vs. untreated specimens. Shear strength values measured for acryl-ic resin teeth were on average 70% higher than those measured for ceramic teeth. The shear bond strength was maximized by preparing samples with thermal-curing resin bases and resin teeth submitted to aluminium oxide sandblasting.

  2. Association between handgrip strength and cognitive impairment in elderly Koreans: a population-based cross-sectional study.

    PubMed

    Jang, Jae Yong; Kim, Junghoon

    2015-12-01

    [Purpose] The purpose of this study was to investigate the association between handgrip strength and mild cognitive impairment in elderly adults. [Subjects] Study participants included 2,982 adults (1,366 males and 1,616 females), aged 65 years or older. [Methods] This population-based cross-sectional study used the baseline database from the Korean Longitudinal Study of Ageing. [Results] The odds ratio for mild cognitive impairment showed a significant linear decrease in relation to the quartile of handgrip strength, independent of potential covariates, in both men and women. Moreover, after excluding incident cases of mild cognitive impairment, the results showed that greater handgrip strength was associated with higher cognitive function scores in the elderly. [Conclusion] The findings presented here suggest that handgrip strength is associated with a risk of mild cognitive impairment in the Korean elderly. Moreover, greater handgrip strength is associated with higher cognitive function in cognitively normal elderly individuals.

  3. EEG signal features extraction based on fractal dimension.

    PubMed

    Finotello, Francesca; Scarpa, Fabio; Zanon, Mattia

    2015-08-01

    The spread of electroencephalography (EEG) in countless applications has fostered the development of new techniques for extracting synthetic and informative features from EEG signals. However, the definition of an effective feature set depends on the specific problem to be addressed and is currently an active field of research. In this work, we investigated the application of features based on fractal dimension to a problem of sleep identification from EEG data. We demonstrated that features based on fractal dimension, including two novel indices defined in this work, add valuable information to standard EEG features and significantly improve sleep identification performance. PMID:26737209

  4. Using strength-based approaches to explore pretreatment change in men who abuse their partners.

    PubMed

    Curwood, Susan Eckerle; DeGeer, Ian; Hymmen, Peter; Lehmann, Peter

    2011-09-01

    Group work with men who batter has traditionally consisted predominantly of psychoeducational programs that ignore concepts such as self-determination, goal setting, and positive engagement with men. More recently, this paradigm has begun to shift to include cognitive approaches and the utilization of strength-based strategies. The present sample included 42 men who were part of an ongoing batterer intervention program. Information for this study included assessment of each man's strengths, their goals, and their perceptions of the changes they felt they had already made prior to attending group treatment. Through a grounded theory analysis, a model was developed that highlights the pretherapeutic change processes that men experience due to their being arrested, charged with a misdemeanour domestic charge, and subsequently convicted of domestic violence. Particularly highlighted are changes in the ways that men view and navigate three distinct areas of their lives: their external world (including work and education); their internal world (perception of self, values, and skills); and their interpersonal relationships with their partner and children.

  5. Tensile strengths of polyamide based 3D printed polymers in liquid nitrogen

    NASA Astrophysics Data System (ADS)

    Cruz, P.; Shoemake, E. D.; Adam, P.; Leachman, J.

    2015-12-01

    Advances in additive manufacturing technology have made 3D printing a viable solution for many industries, allowing for the manufacture of designs that could not be made through traditional subtractive methods. Applicability of additive manufacturing in cryogenic applications is hindered, however, by a lack of accurate material properties information. Nylon is available for printing using fused deposition modeling (FDM) and selective laser sintering (SLS). We selected 5 SLS (DuraForm® EX, DuraForm® HST, DuraForm® PA, PA 640-GSL, and PA 840-GSL) and 2 FDM (Nylon 12, ULTEM) nylon variants based on the bulk material properties and printed properties at room temperature. Tensile tests were performed on five samples of each material while immersed in liquid nitrogen at approximately 77 Kelvin. Samples were tested in XY and, where available, Z printing directions to determine influence on material properties. Results show typical SLS and FDM nylon ultimate strength retention at 77 K, when compared to (extruded or molded) nylon ultimate strength.

  6. Development of base isolation device complied with the ultimate strength design code in Japan

    NASA Astrophysics Data System (ADS)

    Nishimura, Isao; Suzuki, Satoshi

    2016-04-01

    This paper reports the scheme of a research project funded by the Ministry of Land Infrastructure Transport and Tourism (MLIT) from the fiscal year of 2012 to 2014 under the title of "Development of base isolation device complied with the ultimate strength design code." The theoretical prediction tells us a new approach to develop a highly stable laminated rubber bearing that has a constant buckling load even under large lateral displacement. Relatively high shear stiffness makes it more stable and the height of the bearing should be longer than its diameter. They are the newly discovered theoretical buckling stability criteria from the previous studies conducted by the author's research team. The experimental studies in this project show the compatibility with the theoretical prediction and highly linear loaddisplacement relationship under large deformation. The performance of the newly developed device satisfies the requirement of the ultimate strength design code, if the ground condition of the target building is normally solid enough to prevent liquefaction. The theoretically predicted buckling stability of the laminated rubber bearings has been experimentally verified by the specimens of this project.

  7. Phthalonitrile-Based Carbon Foam with High Specific Mechanical Strength and Superior Electromagnetic Interference Shielding Performance.

    PubMed

    Zhang, Liying; Liu, Ming; Roy, Sunanda; Chu, Eng Kee; See, Kye Yak; Hu, Xiao

    2016-03-23

    Electromagnetic interference (EMI) performance materials are urgently needed to relieve the increasing stress over electromagnetic pollution problems arising from the growing demand for electronic and electrical devices. In this work, a novel ultralight (0.15 g/cm(3)) carbon foam was prepared by direct carbonization of phthalonitrile (PN)-based polymer foam aiming to simultaneously achieve high EMI shielding effectiveness (SE) and deliver effective weight reduction without detrimental reduction of the mechanical properties. The carbon foam prepared by this method had specific compressive strength of ∼6.0 MPa·cm(3)/g. High EMI SE of ∼51.2 dB was achieved, contributed by its intrinsic nitrogen-containing structure (3.3 wt% of nitrogen atoms). The primary EMI shielding mechanism of such carbon foam was determined to be absorption. Moreover, the carbon foams showed excellent specific EMI SE of 341.1 dB·cm(3)/g, which was at least 2 times higher than most of the reported material. The remarkable EMI shielding performance combined with high specific compressive strength indicated that the carbon foam could be considered as a low-density and high-performance EMI shielding material for use in areas where mechanical integrity is desired.

  8. Kernel-based machine learning techniques for infrasound signal classification

    NASA Astrophysics Data System (ADS)

    Tuma, Matthias; Igel, Christian; Mialle, Pierrick

    2014-05-01

    Infrasound monitoring is one of four remote sensing technologies continuously employed by the CTBTO Preparatory Commission. The CTBTO's infrasound network is designed to monitor the Earth for potential evidence of atmospheric or shallow underground nuclear explosions. Upon completion, it will comprise 60 infrasound array stations distributed around the globe, of which 47 were certified in January 2014. Three stages can be identified in CTBTO infrasound data processing: automated processing at the level of single array stations, automated processing at the level of the overall global network, and interactive review by human analysts. At station level, the cross correlation-based PMCC algorithm is used for initial detection of coherent wavefronts. It produces estimates for trace velocity and azimuth of incoming wavefronts, as well as other descriptive features characterizing a signal. Detected arrivals are then categorized into potentially treaty-relevant versus noise-type signals by a rule-based expert system. This corresponds to a binary classification task at the level of station processing. In addition, incoming signals may be grouped according to their travel path in the atmosphere. The present work investigates automatic classification of infrasound arrivals by kernel-based pattern recognition methods. It aims to explore the potential of state-of-the-art machine learning methods vis-a-vis the current rule-based and task-tailored expert system. To this purpose, we first address the compilation of a representative, labeled reference benchmark dataset as a prerequisite for both classifier training and evaluation. Data representation is based on features extracted by the CTBTO's PMCC algorithm. As classifiers, we employ support vector machines (SVMs) in a supervised learning setting. Different SVM kernel functions are used and adapted through different hyperparameter optimization routines. The resulting performance is compared to several baseline classifiers. All

  9. Comparative evaluation of impact and flexural strength of four commercially available flexible denture base materials: an in vitro study.

    PubMed

    Abhay, Pande Neelam; Karishma, Shori

    2013-12-01

    Poly-methyl methacrylate is a rigid material. It is generally observed that the impact and flexural strength of this material is not satisfactory and that is reflected in the continuous efforts to improve these mechanical properties. Hence there was a serious need to make another material which could overcome the limitations of the existing materials and could have better properties, like thermoplastic materials. The study was aimed to evaluate and compare the impact strength and the flexural strength of four different flexible denture base materials (thermoplastic denture base resins) with the conventional denture base material (high impact polymethyl-methacrylate). Two, machine made master moulds of metal blocks according to the size of sample holder of the equipment were prepared to test the impact and flexural strength. Total 40 samples, 10 for each group of flexible denture base materials namely: De-flex (Deflex, United Kingdom), Lucitone FRS (Densply, Germany), Valplast (Novoblast, USA), and Bre-flex (Bredent, Germany) in specially designed flask by injection molded process. For different flexible materials, the time, temperature and pressure for injecting the materials were followed as per the manufacturer's instructions. Total 20 samples for control (Trevelon denture base materials) were prepared by compression moulded process, for each test. ANOVA test was applied to calculate p value. Unpaired t test was applied to calculate t-value. Tukey-Kramer multiple test was provided for comparison between the groups for flexural and impact strength. From the statistical analysis, it was found that, the impact strength of Group III (Valplast) was found to be the highest than all other groups and nearer to the control group. Whereas Group IV (Bre-flex) had the maximum flexural strength. The flexural strength of Group I (De-flex) was lowest than all other groups and nearer to control group. The values were found to be statistically significant but clinically non

  10. Comparative evaluation of impact and flexural strength of four commercially available flexible denture base materials: an in vitro study.

    PubMed

    Abhay, Pande Neelam; Karishma, Shori

    2013-12-01

    Poly-methyl methacrylate is a rigid material. It is generally observed that the impact and flexural strength of this material is not satisfactory and that is reflected in the continuous efforts to improve these mechanical properties. Hence there was a serious need to make another material which could overcome the limitations of the existing materials and could have better properties, like thermoplastic materials. The study was aimed to evaluate and compare the impact strength and the flexural strength of four different flexible denture base materials (thermoplastic denture base resins) with the conventional denture base material (high impact polymethyl-methacrylate). Two, machine made master moulds of metal blocks according to the size of sample holder of the equipment were prepared to test the impact and flexural strength. Total 40 samples, 10 for each group of flexible denture base materials namely: De-flex (Deflex, United Kingdom), Lucitone FRS (Densply, Germany), Valplast (Novoblast, USA), and Bre-flex (Bredent, Germany) in specially designed flask by injection molded process. For different flexible materials, the time, temperature and pressure for injecting the materials were followed as per the manufacturer's instructions. Total 20 samples for control (Trevelon denture base materials) were prepared by compression moulded process, for each test. ANOVA test was applied to calculate p value. Unpaired t test was applied to calculate t-value. Tukey-Kramer multiple test was provided for comparison between the groups for flexural and impact strength. From the statistical analysis, it was found that, the impact strength of Group III (Valplast) was found to be the highest than all other groups and nearer to the control group. Whereas Group IV (Bre-flex) had the maximum flexural strength. The flexural strength of Group I (De-flex) was lowest than all other groups and nearer to control group. The values were found to be statistically significant but clinically non

  11. Phantom with pulsatile arteries to investigate the influence of blood vessel depth on pulse oximeter signal strength.

    PubMed

    Stuban, Norbert; Niwayama, Masatsugu; Santha, Hunor

    2012-01-01

    This paper describes a three-layer head phantom with artificial pulsating arteries at five different depths (1.2 mm, 3.7 mm, 6.8 mm, 9.6 mm and 11.8 mm). The structure enables formation of spatially and temporally varying tissue properties similar to those of living tissues. In our experiment, pressure pulses were generated in the arteries by an electronically controlled pump. The physical and optical parameters of the layers and the liquid in the artificial arteries were similar to those of real tissues and blood. The amplitude of the pulsating component of the light returning from the phantom tissues was measured at each artery depth mentioned above. The build-up of the in-house-developed pulse oximeter used for performing the measurements and the physical layout of the measuring head are described. The radiant flux generated by the LED on the measuring head was measured to be 1.8 mW at 910 nm. The backscattered radiant flux was measured, and found to be 0.46 nW (0.26 ppm), 0.55 nW (0.31 ppm), and 0.18 nW (0.10 ppm) for the 1.2 mm, 3.7 mm and 6.8 mm arteries, respectively. In the case of the 9.6 mm and 11.8 mm arteries, useful measurement data were not obtained owing to weak signals. We simulated the phantom with the arteries at the above-mentioned five depths and at two additional ones (2.5 mm and 5.3 mm in depth) using the Monte Carlo method. The measurement results were verified by the simulation results. We concluded that in case of 11 mm source-detector separation the arteries at a depth of about 2.5 mm generate the strongest pulse oximeter signal level in a tissue system comprising three layers of thicknesses: 1.5 mm (skin), 5.0 mm (skull), and >50 mm (brain).

  12. Similarity-Based Modeling Applied to Signal Detection in Pharmacovigilance

    PubMed Central

    Vilar, S; Ryan, P B; Madigan, D; Stang, P E; Schuemie, M J; Friedman, C; Tatonetti, N P; Hripcsak, G

    2014-01-01

    One of the main objectives in pharmacovigilance is the detection of adverse drug events (ADEs) through mining of healthcare databases, such as electronic health records or administrative claims data. Although different approaches have been shown to be of great value, research is still focusing on the enhancement of signal detection to gain efficiency in further assessment and follow-up. We applied similarity-based modeling techniques, using 2D and 3D molecular structure, ADE, target, and ATC (anatomical therapeutic chemical) similarity measures, to the candidate associations selected previously in a medication-wide association study for four ADE outcomes. Our results showed an improvement in the precision when we ranked the subset of ADE candidates using similarity scorings. This method is simple, useful to strengthen or prioritize signals generated from healthcare databases, and facilitates ADE detection through the identification of the most similar drugs for which ADE information is available. PMID:25250527

  13. Fluorescent protein-based biosensors: resolving spatiotemporal dynamics of signaling

    PubMed Central

    DiPilato, Lisa M.; Zhang, Jin

    2009-01-01

    Summary Cellular processes are orchestrated by the precise coordination and regulation of molecular events in the cell. Fluorescent protein-based biosensors coupled with live-cell imaging have enabled the visualization of these events in real time and helped shape some of the current concepts of signal transduction, such as spatial compartmentation. The quantitative information produced by these tools has been incorporated into mathematical models that are capable of predicting highly complex and dynamic behaviors of cellular signaling networks, thus providing a systems level understanding of how pathways interact to produce a functional response. Finally, with technological advances in high throughput and in vivo imaging, these molecular tools promise to continually engender significant contributions to our understanding of cellular processes under normal and diseased conditions. PMID:19910237

  14. Fluorescent protein-based biosensors: resolving spatiotemporal dynamics of signaling.

    PubMed

    DiPilato, Lisa M; Zhang, Jin

    2010-02-01

    Cellular processes are orchestrated by the precise coordination and regulation of molecular events in the cell. Fluorescent protein-based biosensors coupled with live-cell imaging have enabled the visualization of these events in real time and helped shape some of the current concepts of signal transduction, such as spatial compartmentation. The quantitative information produced by these tools has been incorporated into mathematical models that are capable of predicting highly complex and dynamic behaviors of cellular signaling networks, thus providing a systems level understanding of how pathways interact to produce a functional response. Finally, with technological advances in high-throughput and in vivo imaging, these molecular tools promise to continually engender significant contributions to our understanding of cellular processes under normal and diseased conditions.

  15. SARA: A Text-Based and Reader-Based Theory of Signaling

    ERIC Educational Resources Information Center

    Lemarie, Julie; Lorch, Robert F., Jr.; Eyrolle, Helene; Virbel, Jacques

    2008-01-01

    We propose a two-component theory of text signaling devices. The first component is a text-based analysis that characterizes any signaling device along four dimensions: (a) the type of information it makes available, (b) its scope, (c) how it is realized in the text, and (d) its location with respect to the content it cues. The second component is…

  16. Internal wave signal processing: A model-based approach

    SciTech Connect

    Candy, J.V.; Chambers, D.H.

    1995-02-22

    A model-based approach is proposed to solve the oceanic internal wave signal processing problem that is based on state-space representations of the normal-mode vertical velocity and plane wave horizontal velocity propagation models. It is shown that these representations can be utilized to spatially propagate the modal (depth) vertical velocity functions given the basic parameters (wave numbers, Brunt-Vaisala frequency profile etc.) developed from the solution of the associated boundary value problem as well as the horizontal velocity components. These models are then generalized to the stochastic case where an approximate Gauss-Markov theory applies. The resulting Gauss-Markov representation, in principle, allows the inclusion of stochastic phenomena such as noise and modeling errors in a consistent manner. Based on this framework, investigations are made of model-based solutions to the signal enhancement problem for internal waves. In particular, a processor is designed that allows in situ recursive estimation of the required velocity functions. Finally, it is shown that the associated residual or so-called innovation sequence that ensues from the recursive nature of this formulation can be employed to monitor the model`s fit to the data.

  17. FPGA-Based Filterbank Implementation for Parallel Digital Signal Processing

    NASA Technical Reports Server (NTRS)

    Berner, Stephan; DeLeon, Phillip

    1999-01-01

    One approach to parallel digital signal processing decomposes a high bandwidth signal into multiple lower bandwidth (rate) signals by an analysis bank. After processing, the subband signals are recombined into a fullband output signal by a synthesis bank. This paper describes an implementation of the analysis and synthesis banks using (Field Programmable Gate Arrays) FPGAs.

  18. Large-scale deformed QRPA calculations of the gamma-ray strength function based on a Gogny force

    NASA Astrophysics Data System (ADS)

    Martini, M.; Goriely, S.; Hilaire, S.; Péru, S.; Minato, F.

    2016-01-01

    The dipole excitations of nuclei play an important role in nuclear astrophysics processes in connection with the photoabsorption and the radiative neutron capture that take place in stellar environment. We present here the results of a large-scale axially-symmetric deformed QRPA calculation of the γ-ray strength function based on the finite-range Gogny force. The newly determined γ-ray strength is compared with experimental photoabsorption data for spherical as well as deformed nuclei. Predictions of γ-ray strength functions and Maxwellian-averaged neutron capture rates for Sn isotopes are also discussed.

  19. A flexible environmental reuse/recycle policy based on economic strength.

    PubMed

    Tsiliyannis, C A

    2007-01-01

    Environmental policies based on fixed recycling rates may lead to increased environmental impacts (e.g., landfilled wastes) during economic expansion. A rate policy is proposed, which is adjusted according to the overall strength or weakness of the economy, as reflected by overall packaging demand and consumption, production and imports-exports. During economic expansion featuring rising consumption, production or exports, the proposed flexible policy suggests a higher reuse/recycle rate. During economic slowdown a lower rate results in lower impacts. The flexible target rates are determined in terms of annual data, including consumption, imports-exports and production. Higher environmental gains can be achieved at lower cost if the flexible policy is applied to widely consumed packaging products and materials associated with low rates, or if cleaner recycling technology is adopted.

  20. Strength and toughness of composite materials based on nickel aluminide matrices

    NASA Technical Reports Server (NTRS)

    Rigney, J. D.; Khadkikar, P. S.; Lewandowski, J. J.; Vedula, K.

    1989-01-01

    Several nickel aluminide matrix composites were prepared using vacuum hot pressing techniques. The matrix compositions, based on Ni3Al, Ni3Al+B, and NiAl, were reinforced with 10 vol pct TiB2 particles. Both smooth- and notched-bend tests were conducted at room temperature on the monolithic as well as the reinforced materials in order to determine the effects of TiB2 reinforcement on both the smooth-bend and notched-bend properties. TiB2 additions were shown to improve the smooth-bend strengths regardless of the matrix composition, while notched-bend tests, conducted to provide estimates of fracture toughness, revealed somewhat lower values for the composites in comparison to the monolithic materials. Fractographic analyses and in situ fracture observations of the composites revealed that preferential fracture in regions of clustered TiB2 particles may significantly affect the measured toughnesses.

  1. A flexible environmental reuse/recycle policy based on economic strength.

    PubMed

    Tsiliyannis, C A

    2007-01-01

    Environmental policies based on fixed recycling rates may lead to increased environmental impacts (e.g., landfilled wastes) during economic expansion. A rate policy is proposed, which is adjusted according to the overall strength or weakness of the economy, as reflected by overall packaging demand and consumption, production and imports-exports. During economic expansion featuring rising consumption, production or exports, the proposed flexible policy suggests a higher reuse/recycle rate. During economic slowdown a lower rate results in lower impacts. The flexible target rates are determined in terms of annual data, including consumption, imports-exports and production. Higher environmental gains can be achieved at lower cost if the flexible policy is applied to widely consumed packaging products and materials associated with low rates, or if cleaner recycling technology is adopted. PMID:17023151

  2. Numerical simulation of cavitation erosion on a NACA0015 hydrofoil based on bubble collapse strength

    NASA Astrophysics Data System (ADS)

    Hidalgo, V.; Luo, X.; Escaler, X.; Huang, R.; Valencia, E.

    2015-12-01

    The prediction of erosion under unsteady cavitation is crucial to prevent damage in hydraulic machinery. The present investigation deals with the numerical simulation of erosive partial cavitation around a NACA0015 hydrofoil. The study presents the calculation of the bubble collapse strength, Sb, based on the bubble potential energy to identify the surface areas with highest risk of damage. The results are obtained with a numerical scheme assuming homogeneous mixture flow, implicit LES and Zwart cavitation model. The 3D unsteady flow simulation has been solved using OpenFOAM. Python language and OpenFOAM calculator (foamCalcEx) have been used to obtain and represent Sb. The obtained results clearly show the instants of erosive bubble collapse and the affected surface areas.

  3. Lower-extremity strength profiles and gender-based classification of basketball players ages 9-22 years.

    PubMed

    Buchanan, Patricia A; Vardaxis, Vassilios G

    2009-03-01

    Despite an increase in women sports participants and recognition of gender differences in injury patterns (e.g., knee), few normative strength data exist beyond hamstrings and quadriceps measures. This study had 2 purposes: to assess the lower-extremity strength of women (W) and men (M) basketball players who were 9-22 years old, and to determine which strength measures most correctly classify the gender of 12- to 22-year-old athletes. Fifty basketball players (26 W, 24 M) without ligamentous or meniscal injury performed concentric isokinetic testing of bilateral hip, knee, and ankle musculature. We identified maximal peak torques for the hip (flexors, extensors, abductors, adductors), knee (flexors and extensors), and ankle (plantar flexors and dorsiflexors), and we formed periarticular (hip, knee, and ankle), antigravity, and total leg strength composite measures. We calculated mean and 95% confidence intervals. With body mass-height normalization, most age and gender differences were small. Mean values were typically higher for older vs. younger players and for men vs. women players. Mean values were often lower for girls 12-13 years vs. those 9-10 years. In the age group of 16-22 years, men had stronger knee flexors, hip flexors, plantar flexors, and total leg strength than women. Men who were 16-22 years old had stronger knee flexors and hip flexors than did younger men and women players. Based on discriminant function, knee strength measures did not adequately classify gender. Instead, total leg strength measures had correct gender classifications of 74 and 69% (jackknifed) with significant multivariate tests (p = 0.025). For researchers and practitioners, these results support strength assessment and training of the whole lower extremity, not just knee musculature. Limited strength differences between girls 9-10 years old and those 12-13 years old suggest that the peripubertal period is an important time to target strength development.

  4. Effect of various chemicals on the bond strength of acrylic tooth and denture base -An Invitro comparative study

    PubMed Central

    Krishna, V Pridhvi; Premalatha, Averneni; Babu, P Jithendra; Raju, D Srinivasa; Kumar, M Praveen; Rao, D Bheemalingeswara

    2014-01-01

    Background: Debonding of acrylic teeth from the denture base is a common problem. Certain clinical conditions like ridge prominence leads to excess trimming of acrylic teeth and base, resulting in a weak interface. The denture base polymer debonds adhesively in the region of the highly cross –linked matrix of the teeth. To compare the effect of different chemical surface treatments on the bond between cross-linked acrylic teeth and different types of denture base material. Materials & Methods: A total of 180 wax specimens were fabricated and divided into 3 groups: Heat-cure, high impact heat-cure, flexible denture base material bonded to acrylic teeth. Each group was further subdivided into 6 subgroups with 10 specimens each according to the surface treatment ofthe ridge lap area: control, monomer, acetone 99%, chloroform 99%, acrylic adhesive cyanoacrylate, ethyl acetate 99%. After processing, specimens were tested for bond strength using a universal testing machine. The resulting bond strengths were recorded, statistically analyzed and compared. Results: Among all the 3types of denture base resins, highimpact heat-cure denture base resin gave highest bond strength. There was no bonding of teeth with flexible denture base material. Chemical surface treatment of acrylic teeth with ethyl acetate gave highest bond strength followed by control, chloroform, acetone and cyanoacrylate groups. Conclusion: Among all the 3types of denture base materials, high-impact heat-cure denture base resin gave highest bond strength with ethyl acetate surface treatment. Simple and quick tooth chemical surface treatment with ethylacetate could be an effective option in decreasing bonding failures and also avoid repeated denture repairs improving patient satisfaction. How to cite the article: Krishna VP, Premalatha A, Babu PJ, Raju DS, Kumar MP, Rao DB. Effect of various chemicals on the bond strength of acrylic tooth and denture base -An In-vitro comparative study. J Int Oral Health

  5. Subpathway Analysis based on Signaling-Pathway Impact Analysis of Signaling Pathway

    PubMed Central

    Li, Xianbin; Shen, Liangzhong; Shang, Xuequn; Liu, Wenbin

    2015-01-01

    Pathway analysis is a common approach to gain insight from biological experiments. Signaling-pathway impact analysis (SPIA) is one such method and combines both the classical enrichment analysis and the actual perturbation on a given pathway. Because this method focuses on a single pathway, its resolution generally is not very high because the differentially expressed genes may be enriched in a local region of the pathway. In the present work, to identify cancer-related pathways, we incorporated a recent subpathway analysis method into the SPIA method to form the “sub-SPIA method.” The original subpathway analysis uses the k-clique structure to define a subpathway. However, it is not sufficiently flexible to capture subpathways with complex structure and usually results in many overlapping subpathways. We therefore propose using the minimal-spanning-tree structure to find a subpathway. We apply this approach to colorectal cancer and lung cancer datasets, and our results show that sub-SPIA can identify many significant pathways associated with each specific cancer that other methods miss. Based on the entire pathway network in the Kyoto Encyclopedia of Genes and Genomes, we find that the pathways identified by sub-SPIA not only have the largest average degree, but also are more closely connected than those identified by other methods. This result suggests that the abnormality signal propagating through them might be responsible for the specific cancer or disease. PMID:26207919

  6. Chemical Signaling and Functional Activation in Colloidosome-Based Protocells.

    PubMed

    Sun, Shiyong; Li, Mei; Dong, Faqin; Wang, Shengjie; Tian, Liangfei; Mann, Stephen

    2016-04-13

    An aqueous-based microcompartmentalized model involving the integration of partially hydrophobic Fe(III)-rich montmorillonite (FeM) clay particles as structural and catalytic building blocks for colloidosome membrane assembly, self-directed membrane remodeling, and signal-induced protocell communication is described. The clay colloidosomes exhibit size- and charge-selective permeability, and show dual catalytic functions involving spatially confined enzyme-mediated dephosphorylation and peroxidase-like membrane activity. The latter is used for the colloidosome-mediated synthesis and assembly of a temperature-responsive poly(N-isopropylacrylamide)(PNIPAM)/clay-integrated hybrid membrane. In situ PNIPAM elaboration of the membrane is coupled to a glucose oxidase (GOx)-mediated signaling pathway to establish a primitive model of chemical communication and functional activation within a synthetic "protocell community" comprising a mixed population of GOx-containing silica colloidosomes and alkaline phosphatase (ALP)-containing FeM-clay colloidosomes. Triggering the enzyme reaction in the silica colloidosomes gives a hydrogen peroxide signal that induces polymer wall formation in a coexistent population of the FeM-clay colloidosomes, which in turn generates self-regulated membrane-gated ALP-activity within the clay microcompartments. The emergence of new functionalities in inorganic colloidosomes via chemical communication between different protocell populations provides a first step toward the realization of interacting communities of synthetic functional microcompartments. PMID:26923794

  7. Wavelet-based characterization of gait signal for neurological abnormalities.

    PubMed

    Baratin, E; Sugavaneswaran, L; Umapathy, K; Ioana, C; Krishnan, S

    2015-02-01

    Studies conducted by the World Health Organization (WHO) indicate that over one billion suffer from neurological disorders worldwide, and lack of efficient diagnosis procedures affects their therapeutic interventions. Characterizing certain pathologies of motor control for facilitating their diagnosis can be useful in quantitatively monitoring disease progression and efficient treatment planning. As a suitable directive, we introduce a wavelet-based scheme for effective characterization of gait associated with certain neurological disorders. In addition, since the data were recorded from a dynamic process, this work also investigates the need for gait signal re-sampling prior to identification of signal markers in the presence of pathologies. To benefit automated discrimination of gait data, certain characteristic features are extracted from the wavelet-transformed signals. The performance of the proposed approach was evaluated using a database consisting of 15 Parkinson's disease (PD), 20 Huntington's disease (HD), 13 Amyotrophic lateral sclerosis (ALS) and 16 healthy control subjects, and an average classification accuracy of 85% is achieved using an unbiased cross-validation strategy. The obtained results demonstrate the potential of the proposed methodology for computer-aided diagnosis and automatic characterization of certain neurological disorders. PMID:25661004

  8. Pattern recognition for electroencephalographic signals based on continuous neural networks.

    PubMed

    Alfaro-Ponce, M; Argüelles, A; Chairez, I

    2016-07-01

    This study reports the design and implementation of a pattern recognition algorithm to classify electroencephalographic (EEG) signals based on artificial neural networks (NN) described by ordinary differential equations (ODEs). The training method for this kind of continuous NN (CNN) was developed according to the Lyapunov theory stability analysis. A parallel structure with fixed weights was proposed to perform the classification stage. The pattern recognition efficiency was validated by two methods, a generalization-regularization and a k-fold cross validation (k=5). The classifier was applied on two different databases. The first one was made up by signals collected from patients suffering of epilepsy and it is divided in five different classes. The second database was made up by 90 single EEG trials, divided in three classes. Each class corresponds to a different visual evoked potential. The pattern recognition algorithm achieved a maximum correct classification percentage of 97.2% using the information of the entire database. This value was similar to some results previously reported when this database was used for testing pattern classification. However, these results were obtained when only two classes were considered for the testing. The result reported in this study used the whole set of signals (five different classes). In comparison with similar pattern recognition methods that even considered less number of classes, the proposed CNN proved to achieve the same or even better correct classification results.

  9. Pattern recognition for electroencephalographic signals based on continuous neural networks.

    PubMed

    Alfaro-Ponce, M; Argüelles, A; Chairez, I

    2016-07-01

    This study reports the design and implementation of a pattern recognition algorithm to classify electroencephalographic (EEG) signals based on artificial neural networks (NN) described by ordinary differential equations (ODEs). The training method for this kind of continuous NN (CNN) was developed according to the Lyapunov theory stability analysis. A parallel structure with fixed weights was proposed to perform the classification stage. The pattern recognition efficiency was validated by two methods, a generalization-regularization and a k-fold cross validation (k=5). The classifier was applied on two different databases. The first one was made up by signals collected from patients suffering of epilepsy and it is divided in five different classes. The second database was made up by 90 single EEG trials, divided in three classes. Each class corresponds to a different visual evoked potential. The pattern recognition algorithm achieved a maximum correct classification percentage of 97.2% using the information of the entire database. This value was similar to some results previously reported when this database was used for testing pattern classification. However, these results were obtained when only two classes were considered for the testing. The result reported in this study used the whole set of signals (five different classes). In comparison with similar pattern recognition methods that even considered less number of classes, the proposed CNN proved to achieve the same or even better correct classification results. PMID:27131469

  10. High reliability outdoor sonar prototype based on efficient signal coding.

    PubMed

    Alvarez, Fernando J; Ureña, Jesús; Mazo, Manuel; Hernández, Alvaro; García, Juan J; de Marziani, Carlos

    2006-10-01

    Many mobile robots and autonomous vehicles designed for outdoor operation have incorporated ultrasonic sensors in their navigation systems, whose function is mainly to avoid possible collisions with very close obstacles. The use of these systems in more precise tasks requires signal encoding and the incorporation of pulse compression techniques that have already been used with success in the design of high-performance indoor sonars. However, the transmission of ultrasonic encoded signals outdoors entails a new challenge because of the effects of atmospheric turbulence. This phenomenon causes random fluctuations in the phase and amplitude of traveling acoustic waves, a fact that can make the encoded signal completely unrecognizable by its matched receiver. Atmospheric turbulence is investigated in this work, with the aim of determining the conditions under which it is possible to assure the reliable outdoor operation of an ultrasonic pulse compression system. As a result of this analysis, a novel sonar prototype based on complementary sequences coding is developed and experimentally tested. This encoding scheme provides the system with very useful additional features, namely, high robustness to noise, multi-mode operation capability (simultaneous emissions with minimum cross talk interference), and the possibility of applying an efficient detection algorithm that notably decreases the hardware resource requirements.

  11. Effect of an Extra Hydrophobic Resin Layer on Repair Shear Bond Strength of a Silorane-Based Composite Resin

    PubMed Central

    Mohammadi, Narmin; Bahari, Mahmoud; Kimyai, Soodabeh; Rahbani Nobar, Behnam

    2015-01-01

    Objectives: Composite repair is a minimally invasive and conservative approach. This study aimed to evaluate the effect of an additional hydrophobic resin layer on the repair shear bond strength of a silorane-based composite repaired with silorane or methacrylate-based composite. Materials and Methods: Sixty bar-shaped composite blocks were fabricated and stored in saline for 72 hours. The surface of the samples were roughened by diamond burs and etched with phosphoric acid; then, they were randomly divided into three groups according to the repairing process: Group 1: Silorane composite-silorane bonding agent-silorane composite; group 2: Silorane composite-silorane bonding agent-hydrophobic resin-silorane composite, and group 3: Silorane composite-silorane bonding agent-hydrophobic resin methacrylate-based composite. Repairing composite blocks measured 2.5×2.5×5mm. After repairing, the samples were stored in saline for 24 hours and thermocycled for 1500 cycles. The repair bond strength was measured at a strain rate of 1mm/min. Twenty additional cylindrical composite blocks (diameter: 2.5mm, height: 6mm) were also fabricated for measuring the cohesive strength of silorane-based composite. The data were analyzed using One-way ANOVA and the post hoc Tukey’s test (α=0.05). Results: Cohesive bond strength of silorane composite was significantly higher than the repair bond strengths in other groups (P<0.001). The repair bond strength of group 3 was significantly higher than that of group 1 (P=0.001). Conclusion: Application of an additional hydrophobic resin layer for repair of silorane-based composite with a methacrylate-based composite enhanced the repair shear bond strength. PMID:27559348

  12. Effect of bracket base design on shear bond strength to feldspathic porcelain

    PubMed Central

    Dalaie, Kazem; Mirfasihi, Armin; Eskandarion, Solmaz; Kabiri, Sattar

    2016-01-01

    Objectives: This study sought to assess the effect of bracket base design on the shear bond strength (SBS) of the bracket to feldspathic porcelain. Materials and Methods: This in vitro, experimental study was conducted on 40 porcelain-fused-to-metal restorations and four different bracket base designs were bonded to these specimens. The porcelain surfaces were etched, silanized, and bonded to brackets. Specimens were thermocycler, incubated for 24 h and were subjected to SBS. Data were analyzed using Shapiro–Wilk test, Levene's test, one-way ANOVA, and Tukey's honest significant difference test. Adhesive remnant index was calculated and compared using Fisher's exact test. Results: One-way ANOVA showed that the SBS values were significantly different among the four groups (P < 0.001). Groups 1, 2, and 4 were not significantly different, but group 3 had significantly lower SBS (P < 0.001). Fractures mostly occurred at the porcelain-adhesive interface in Groups 1 and 2 while in Groups 3 and 4, bracket-adhesive and mixed failures were more common. Conclusion: The bracket base design significantly affects the SBS to feldspathic porcelain. PMID:27403052

  13. Nanostructured Zr- and Ti-based composite materials with high strength and enhanced plasticity

    SciTech Connect

    Kuehn, U.; Mattern, N.; Gebert, A.; Kusy, M.; Bostroem, M.; Siegel, U.; Schultz, L.

    2005-09-01

    Multicomponent composite materials with the compositions Zr{sub 66}Nb{sub 13}Cu{sub 8}Ni{sub 6.8}Al{sub 6.2} and Ti{sub 66}Nb{sub 13}Cu{sub 8}Ni{sub 6.8}Al{sub 6.2} were produced by copper mold casting, and their microstructure and their room-temperature mechanical properties were investigated. The specific alloys were developed to circumvent the limited ductility of Zr- and Ti-based bulk metallic glasses by the formation of a heterogeneous microstructure consisting of a nanocrystalline matrix and ductile dendritic bcc precipitates. Comparing the microstructure of both alloys, two significant differences were observed. The volume fraction of the dendritic bcc phase is higher for the Ti-based alloy and the formed interdendritic matrix phase(s) have a different structure. The two alloys show an excellent combination of strength and plastic strain. Especially the Ti-based alloy exhibits exceptional mechanical properties, such as high fracture stress of more than 2000 MPa and a plastic elongation to failure of almost 30%.

  14. Relationships between field-based measures of strength and power and golf club head speed.

    PubMed

    Read, Paul J; Lloyd, Rhodri S; De Ste Croix, Mark; Oliver, Jon L

    2013-10-01

    Increased golf club head speed (CHS) has been shown to result in greater driving distances and is also correlated with golf handicap. The purpose of this study was to investigate the relationships between field-based measures of strength and power and golf CHS with a secondary aim to determine the reliability of the selected tests. A correlation design was used to assess the following variables: anthropometrics, squat jump (SJ) height and squat jump peak power (SJPP), unilateral countermovement jump (CMJ) heights (right leg countermovement jump and left leg countermovement jump [LLCMJ]), bilateral CMJ heights, countermovement jump peak power (CMJPP), and medicine ball seated throw (MBST) and medicine ball rotational throw (MBRT). Fouty-eight male subjects participated in the study (age: 20.1 ± 3.2 years, height: 1.76 ± 0.07 m, mass: 72.8 ± 7.8 kg, handicap: 5.8 ± 2.2). Moderate significant correlations were reported between CHS and MBRT (r = 0.67; p < 0.01), MBST (r = 0.63; p < 0.01), CMJPP (r = 0.54; p < 0.01), and SJPP (r = 0.53; p < 0.01). Weak significant correlations (r = 0.3-0.5) were identified between CHS and the other remaining variables excluding LLCMJ. Stepwise multiple regression analysis identified that the MBST and SJ were the greatest predictors of CHS, explaining 49% of the variance. Additionally the intraclass correlation coefficients reported for tests of CHS and all performance variables were deemed acceptable (r = 0.7-0.9). The results of this study suggest that the strength and conditioning coach can accurately assess and monitor the physical abilities of golf athletes using the proposed battery of field tests. Additionally, movements that are more concentrically dominant in nature may display stronger relationships with CHS due to MBST and SJ displaying the highest explained variance after a stepwise linear regression.

  15. Flexural strengths of implant-supported zirconia based bridges in posterior regions

    PubMed Central

    Rismanchian, Mansour; Nourbakhshian, Farzaneh; Davoudi, Amin

    2014-01-01

    PURPOSE Impact forces in implant supported FDP (fixed dental prosthesis) are higher than that of tooth supported FDPs and the compositions used in frameworks also has a paramount role for biomechanical reasons. The aim of this study was to evaluate the flexural strength of two different zirconia frameworks. MATERIALS AND METHODS Two implant abutments with 3.8 mm and 4.5 mm platform were used as premolar and molar. They were mounted vertically in an acrylic resin block. A model with steel retainers and removable abutments was fabricated by milling machine; and 10 FDP frameworks were fabricated for each Biodenta and Cercon systems. All samples were thermo-cycled for 2000 times in 5-55℃ temperature and embedded in 37℃ artificial saliva for one week. The flexural test was done by a rod with 2 mm ending diameter which was applied to the multi-electromechanical machine. The force was inserted until observing fracture. The collected data were analyzed with SPSS software ver.15, using Weibull modulus and independent t-test with the level of significance at α=.05. RESULTS The mean load bearing capacity values were higher in Biodenta but with no significant differences (P>.05). The Biodenta frameworks showed higher load bearing capacity (F0=1700) than Cercon frameworks (F0=1520) but the reliability (m) was higher in Cercon (m=7.5). CONCLUSION There was no significant difference between flexural strengths of both zirconia based framework systems; and both Biodenta and Cercon systems are capable to withstand biting force (even parafunctions) in posterior implant-supported bridges with no significant differences. PMID:25352956

  16. Ultrafast optical signal processing on silicon-based platforms

    NASA Astrophysics Data System (ADS)

    Tan, Dawn T. H.

    2016-03-01

    The development of silicon - based photonic components and systems has advanced tremendously over the last decade, largely for applications in optical interconnects. The role of silicon - based platforms for both linear and nonlinear optics remains highly pertinent because of their ability to be integrated with CMOS - based electronics. In this paper, we present recent research progress pertaining to ultrafast optical signal processing on silicon - based platforms. Advances in on - chip multiplexing strategies with the potential for meeting 200GHz dense wavelength division multiplexing standards across the C - and L - bands will be discussed. In addition, the development of a silicon - based nonlinear optics platform with high nonlinear figures of merit will be presented. Nonlinear optical devices fabricated from the developed platform possess nonlinear parameters 500 times larger than that in silicon nitride waveguides, while possessing negligible nonlinear losses at 1.55μm. Ultra - broadband, low power nonlinear wavelength generation using these devices, as well as their potential for realizing advanced light sources for optical interconnect - based applications will be presented.

  17. Coherent seismic sea-bottom profiling based on broadband signals

    NASA Astrophysics Data System (ADS)

    Lazarev, V. A.; Malekhanov, A. I.; Merklin, L. R.; Romanova, V. I.; Talanov, V. I.; Khil'ko, A. I.

    2013-11-01

    Experimental results of the seismic profiling with bottom penetration up to 1000 m based on broadband signals and conducted in the Caspian Sea sites are presented. Use has been made of synchronized sequences of probing pulses with linear frequency modulation at a frequency deviation of 50 to100 Hz. The pulses were emitted by a towed sound source of an original design (acoustic power up to 300 W, frequency ranged from 100 to 1000 Hz) and received by a standard digital seismic streamer. The processing of the signals involved the matched filtering of the individual pulses and the trajectory accumulation of a long sequence of pulses lengthwise the horizontal-homogeneous reflecting layers of the bottom structure. The adaptive stacking procedure taking into account the linear inclinations of the individual layers allowed us to enlarge the stacking interval by up to 100 pulses and to increase the effective depth and the spatial resolution of the seismic profiling, which gave us a total increase of more than 30 dB in the S/N ratio. In our view, the seismic profiling using low-power (about 100 W) and broadband (up to several hundred Hz) coherent sound sources represents a promising technology for decreasing the hazardous impact on aquatic ecosystems. The approach developed is an alternative to the conventional technology of marine seismic prospecting based on powerful pulse sources of the shock type (air guns, sparkers) in the low frequency range (less than ˜200 Hz).

  18. The Applicability of Two Strengths-Based Systemic Psychotherapy Models for Young People Following Type 1 Trauma

    ERIC Educational Resources Information Center

    Coulter, Stephen

    2014-01-01

    This paper will consider the inter-relationship of a number of overlapping disciplinary theoretical concepts relevant to a strengths-based orientation, including well-being, salutogenesis, sense of coherence, quality of life and resilience. Psychological trauma will be referenced and the current evidence base for interventions with children and…

  19. Tone based command system for reception of very weak signals

    NASA Technical Reports Server (NTRS)

    Bokulic, Robert Steven (Inventor); Jensen, James Robert (Inventor)

    2006-01-01

    This disclosure presents a communication receiver system for spacecraft that includes an open loop receiver adapted to receive a communication signal. An ultrastable oscillator (USO) and a tone detector are connected to the open loop receiver. The open loop receiver translates the communication signal to an intermediate frequency signal using a highly stable reference frequency from the USO. The tone detector extracts commands from the communication signal by evaluating the difference between tones of the communication signal.

  20. Process for producing silicon nitride based articles of high fracture toughness and strength

    DOEpatents

    Huckabee, M.; Buljan, S.T.; Neil, J.T.

    1991-09-10

    A process for producing a silicon nitride-based article of improved fracture toughness and strength is disclosed. The process involves densifying to at least 98% of theoretical density a mixture including (a) a bimodal silicon nitride powder blend consisting essentially of about 10-30% by weight of a first silicon nitride powder of an average particle size of about 0.2 [mu]m and a surface area of about 8-12 m[sup 2]/g, and about 70-90% by weight of a second silicon nitride powder of an average particle size of about 0.4-0.6 [mu]m and a surface area of about 2-4 m[sup 2]/g, (b) about 10-50 percent by volume, based on the volume of the densified article, of refractory whiskers or fibers having an aspect ratio of about 3-150 and having an equivalent diameter selected to produce in the densified article an equivalent diameter ratio of the whiskers or fibers to grains of silicon nitride of greater than 1.0, and (c) an effective amount of a suitable oxide densification aid. Optionally, the mixture may be blended with a binder and injection molded to form a green body, which then may be densified by, for example, hot isostatic pressing.

  1. Process for producing silicon nitride based articles of high fracture toughness and strength

    DOEpatents

    Huckabee, Marvin; Buljan, Sergej-Tomislav; Neil, Jeffrey T.

    1991-01-01

    A process for producing a silicon nitride-based article of improved fracture toughness and strength. The process involves densifying to at least 98% of theoretical density a mixture including (a) a bimodal silicon nitride powder blend consisting essentially of about 10-30% by weight of a first silicon nitride powder of an average particle size of about 0.2 .mu.m and a surface area of about 8-12 m.sup.2 /g, and about 70-90% by weight of a second silicon nitride powder of an average particle size of about 0.4-0.6 .mu.m and a surface area of about 2-4 m.sup.2 /g, (b) about 10-50 percent by volume, based on the volume of the densified article, of refractory whiskers or fibers having an aspect ratio of about 3-150 and having an equivalent diameter selected to produce in the densified article an equivalent diameter ratio of the whiskers or fibers to grains of silicon nitride of greater than 1.0, and (c) an effective amount of a suitable oxide densification aid. Optionally, the mixture may be blended with a binder and injection molded to form a green body, which then may be densified by, for example, hot isostatic pressing.

  2. Silorane- and high filled-based "low-shrinkage" resin composites: shrinkage, flexural strength and modulus.

    PubMed

    Arrais, Cesar Augusto Galvão; Oliveira, Marcelo Tavares de; Mettenburg, Donald; Rueggeberg, Frederick Allen; Giannini, Marcelo

    2013-01-01

    This study compared the volumetric shrinkage (VS), flexural strength (FS) and flexural modulus (FM) properties of the low-shrinkage resin composite Aelite LS (Bisco) to those of Filtek LS (3M ESPE) and two regular dimethacrylate-based resin composites, the microfilled Heliomolar (Ivoclar Vivadent) and the microhybrid Aelite Universal (Bisco). The composites (n = 5) were placed on the Teflon pedestal of a video-imaging device, and VS was recorded every minute for 5 min after 40 s of light exposure. For the FS and FM tests, resin discs (0.6 mm in thickness and 6.0 mm in diameter) were obtained (n = 12) and submitted to a piston-ring biaxial test in a universal testing machine. VS, FS, and FM data were submitted to two-way repeated measures and one-way ANOVA, respectively, followed by Tukey's post-hoc test (a = 5%). Filtek LS showed lower VS than did Aelite LS, which in turn showed lower shrinkage than did the other composites. Aelite Universal and Filtek LS exhibited higher FS than did Heliomolar and Aelite LS, both of which exhibited the highest FM. No significant difference in FM was noted between Filtek LS and Aelite Universal, while Heliomolar exhibited the lowest values. Aelite LS was not as effective as Filtek LS regarding shrinkage, although both low-shrinkage composites showed lower VS than did the other composites. Only Filtek LS exhibited FS and FM comparable to those of the regular microhybrid dimethacrylate-based resin composite. PMID:23459774

  3. Bond Strengths of Silorane- and Methacrylate-Based Composites to Various Underlying Materials

    PubMed Central

    Ozer, Sezin; Sen Tunc, Emine; Gonulol, Nihan

    2014-01-01

    Objective. To evaluate shear bond strength (SBS) values of a methacrylate (FZ 250) and a silorane-based (FS) resin composite to various underlying materials. Materials and Methods. A total of 80 samples were prepared with four different underlying materials; a flowable (FLC) and a bulk-fill flowable composite (BFC), and a conventional (CGIC) and resin modified glass-ionomer cement (RMGIC). These underlying materials were laminated plus to methacrylate or silorane-based resin composites (n = 10). To evaluate the specimens SBS values were evaluated with a universal testing machine (cross-head speed; 1.0 mm/min). Statistical comparisons were carried out using two-way ANOVA and Tukey's post hoc test with a significance level of P < 0.05. Results. SBS values for FZ250 were significantly higher than for FS for all of the underlying materials tested (P < 0.05). SBS values of FZ250 to BFC were significantly higher than to all other materials (P < 0.05), whereas SBS values of FS did not vary significantly according to underlying material (P > 0.05). Conclusion. The use of FS in conjunction with any of the tested materials showed lower SBS than the FZ 250. Also, new low elastic modulus liner BFC presented slightly good interfacial adhesion so, the usage of BFC as an underlying material may be preferable for FZ 250. PMID:24895608

  4. Influence of Surface Modifications of Acrylic Resin Teeth on Shear Bond Strength with Denture Base Resin-An Invitro Study

    PubMed Central

    Krishnan, Madhusudan; Krishnan, Chitra Shankar; Azhagarasan, N.S.; Sampathkumar, Jayakrishnakumar; Ramasubramanian, Hariharan

    2015-01-01

    Background Debonding of artificial teeth from the denture base is an important issue for edentulous patients rehabilitated with conventional or implant supported complete dentures. Aim The purpose of this study was to evaluate shear bond strength between denture base resin and acrylic resin denture teeth subjected to three different surface modifications on the ridge lap area as compared to unmodified denture teeth. Materials and Methods Forty acrylic resin central incisor denture teeth were selected and randomly divided into four test groups. The teeth in each group were subjected to one of the three different surface modifications, namely, chemical treatment, sandblasting and placement of retentive grooves on the ridge lap area respectively, prior to packing of the denture base resin. The group with unmodified teeth served as control. Forty acrylic resin test blocks thus obtained were tested for shear bond strength between acrylic resin teeth and denture base resin in Universal Testing Machine. Data obtained was statistically analysed using one-way ANOVA and Student- Newman- Keul’s test (p< 0.05). Results Analysis of shear bond strength revealed that retentive grooves on the ridge lap area showed highest bond strength values followed by sandblasting and both were statistically significant compared to the control and chemically treated groups. Unmodified surface of the resin teeth showed the least bond strength. Conclusion Within the limitations of this invitro study the placement of retentive grooves or sandblasting of the ridge lap area showed highly significant improvement in shear bond strength compared to the unmodified surface. Chemical treatment did not result in any significant improvement in the shear bond strength compared to the unmodified surface. PMID:26501005

  5. Affective Teaching for Data Driven Learning: How Can Strengths-Based Training Support Urban Teacher Efficacy?

    ERIC Educational Resources Information Center

    Marcos, Teri

    2008-01-01

    The purpose of this study was to examine urban teachers' identified strengths in varied cognitive, affective, and psychological capacities, and their impact on self-efficacy and teacher practices. Clifton and Anderson in the Gallup Organization's Strengths Quest (2004) presented compelling evidence suggesting a mind-set of "what's right with me"…

  6. The Potential of Spaced-based High-Energy Neutrino Measurements via the Airshower Cherenkov Signal

    NASA Technical Reports Server (NTRS)

    Krizmanic, John F.; Mitchell, John W.

    2011-01-01

    Future space-based experiments, such as (Orbiting Wide-angle Light Collectors (OWL) and JEM-EUSO, view large atmospheric and terrestrial neutrino targets. With energy thresholds slightly above 10(exp 19) eV for observing airshowers via air fluorescence, the potential for observing the cosmogenic neutrino flux associated with the GZK effect is limited. However, the forward Cherenkov signal associated with the airshower can be observed at much lower energies. A simulation was developed to determine the Cherenkov signal strength and spatial extent at low-Earth orbit for upward-moving airshowers. A model of tau neutrino interactions in the Earth was employed to determine the event rate of interactions that yielded a tau lepton which would induce an upward-moving airshower observable by a space-based instrument. The effect of neutrino attenuation by the Earth forces the viewing of the Earth's limb to observe the vT-induced Cherenkov airshower signal at above the OWL Cherenkov energy threshold of approximately 10(exp 16.5) eV for limb-viewed events. Furthermore, the neutrino attenuation limits the effective terrestrial neutrino target area to approximately 3 x 10(exp 5) square km at 10(exp 17) eV, for an orbit of 1000 km and an instrumental full Field-of-View of 45 deg. This translates into an observable cosmogenic neutrino event rate of approx. l/year based upon two different models of the cosmogenic neutrino flux, assuming neutrino oscillations and a 10% duty cycle for observation.

  7. Signal quality and Bayesian signal processing in neurofeedback based on real-time fMRI.

    PubMed

    Koush, Yury; Zvyagintsev, Mikhail; Dyck, Miriam; Mathiak, Krystyna A; Mathiak, Klaus

    2012-01-01

    Real-time fMRI allows analysis and visualization of the brain activity online, i.e. within one repetition time. It can be used in neurofeedback applications where subjects attempt to control an activation level in a specified region of interest (ROI) of their brain. The signal derived from the ROI is contaminated with noise and artifacts, namely with physiological noise from breathing and heart beat, scanner drift, motion-related artifacts and measurement noise. We developed a Bayesian approach to reduce noise and to remove artifacts in real-time using a modified Kalman filter. The system performs several signal processing operations: subtraction of constant and low-frequency signal components, spike removal and signal smoothing. Quantitative feedback signal quality analysis was used to estimate the quality of the neurofeedback time series and performance of the applied signal processing on different ROIs. The signal-to-noise ratio (SNR) across the entire time series and the group event-related SNR (eSNR) were significantly higher for the processed time series in comparison to the raw data. Applied signal processing improved the t-statistic increasing the significance of blood oxygen level-dependent (BOLD) signal changes. Accordingly, the contrast-to-noise ratio (CNR) of the feedback time series was improved as well. In addition, the data revealed increase of localized self-control across feedback sessions. The new signal processing approach provided reliable neurofeedback, performed precise artifacts removal, reduced noise, and required minimal manual adjustments of parameters. Advanced and fast online signal processing algorithms considerably increased the quality as well as the information content of the control signal which in turn resulted in higher contingency in the neurofeedback loop.

  8. Cardiac signal estimation based on the arterial and venous pressure signals of a hemodialysis machine.

    PubMed

    Holmer, M; Sandberg, F; Solem, K; Olde, B; Sörnmo, L

    2016-09-01

    Continuous cardiac monitoring is usually not performed during hemodialysis treatment, although a majority of patients with kidney failure suffer from cardiovascular disease. In the present paper, a method is proposed for estimating a cardiac pressure signal by combining the arterial and the venous pressure sensor signals of the hemodialysis machine. The estimation is complicated by the periodic pressure disturbance caused by the peristaltic blood pump, with an amplitude much larger than that of the cardiac pressure signal. Using different techniques for combining the arterial and venous pressure signals, the performance is evaluated and compared to that of an earlier method which made use of the venous pressure only. The heart rate and the heartbeat occurrence times, determined from the estimated cardiac pressure signal, are compared to the corresponding quantities determined from a photoplethysmographic reference signal. Signals from 9 complete hemodialysis treatments were analyzed. For a heartbeat amplitude of 0.5 mmHg, the median absolute deviation between estimated and reference heart rate was 1.3 bpm when using the venous pressure signal only, but dropped to 0.6 bpm when combining the pressure signals. The results show that the proposed method offers superior estimation at low heartbeat amplitudes. Consequently, more patients can be successfully monitored during treatment without the need of extra sensors. The results are preliminary, and need to be verified on a separate dataset. PMID:27511299

  9. Extracting dirt from water: a strengths-based approach to religion for African American same-gender-loving men.

    PubMed

    Lassiter, Jonathan Mathias

    2014-02-01

    Religion is one of the most powerful and ubiquitous forces in African American same-gender-loving (SGL) men's lives. Research indicates that it has both positive and negative influences on the health behaviors and outcomes of this population. This paper presents a review of the literature that examines religion as a risk and protective factor for African American SGL men. A strengths-based approach to religion that aims to utilize its protective qualities and weaken its relation to risk is proposed. Finally, recommendations are presented for the use of a strengths-based approach to religion in clinical work and research.

  10. NATIVE TRANSFORMATIONS IN THE PACIFIC NORTHWEST: A STRENGTH-BASED MODEL OF PROTECTION AGAINST SUBSTANCE USE DISORDER

    PubMed Central

    Rasmus, Stacy; Allen, James; Connor, William; Freeman, William; Skewes, Monica

    2016-01-01

    This paper presents findings from the Native Transformations Project, an exploratory community-based participatory research study that aims to identify sources of strength and protection against substance use disorder in three tribal communities in the coastal Pacific Northwest. Preliminary results from the study describe the specific settings, acts, and behaviors that build strengths and provide protection at the family, community, individual, and spiritual levels within coastal Pacific Northwest local tribal cultures. Findings from this study give voice to stated community preferences for grassroots Native intervention programs based in local cultural knowledge, worldviews, values, and theories of change, that operate at the local level on their own terms. PMID:27383091

  11. A Step Response Based Mixed-Signal BIST Approach

    NASA Technical Reports Server (NTRS)

    Walker, Alvernon

    2001-01-01

    A new Mixed-Signal Built-in Self-test approach that is based upon the step response of a reconfigurable (or multifunction) analog block is presented in this paper. The technique requires the overlapping step response of the Circuit Under Test (CUT) for two circuit configurations. Each configuration can be realized by changing the topology of the CUT or by sampling two CUT nodes with differing step responses. The technique can effectively detect both soft and hard faults and does not require an analog-to-digital converter (ADC) and/or digital-to-analog converter( DAC). It also does not require any precision voltage sources or comparators. The approach does not require any additional analog circuits to realize the test signal generator and a two input analog multiplexer for CUT test node sampling. The paper is concluded with the application of the proposed approach to a circuit found in the work of Epstein et a1 and two ITC 97 analog benchmark circuits.

  12. Acoustic emission source localization based on distance domain signal representation

    NASA Astrophysics Data System (ADS)

    Gawronski, M.; Grabowski, K.; Russek, P.; Staszewski, W. J.; Uhl, T.; Packo, P.

    2016-04-01

    Acoustic emission is a vital non-destructive testing technique and is widely used in industry for damage detection, localisation and characterization. The latter two aspects are particularly challenging, as AE data are typically noisy. What is more, elastic waves generated by an AE event, propagate through a structural path and are significantly distorted. This effect is particularly prominent for thin elastic plates. In these media the dispersion phenomenon results in severe localisation and characterization issues. Traditional Time Difference of Arrival methods for localisation techniques typically fail when signals are highly dispersive. Hence, algorithms capable of dispersion compensation are sought. This paper presents a method based on the Time - Distance Domain Transform for an accurate AE event localisation. The source localisation is found through a minimization problem. The proposed technique focuses on transforming the time signal to the distance domain response, which would be recorded at the source. Only, basic elastic material properties and plate thickness are used in the approach, avoiding arbitrary parameters tuning.

  13. Acoustic cardiac signals analysis: a Kalman filter-based approach.

    PubMed

    Salleh, Sheik Hussain; Hussain, Hadrina Sheik; Swee, Tan Tian; Ting, Chee-Ming; Noor, Alias Mohd; Pipatsart, Surasak; Ali, Jalil; Yupapin, Preecha P

    2012-01-01

    Auscultation of the heart is accompanied by both electrical activity and sound. Heart auscultation provides clues to diagnose many cardiac abnormalities. Unfortunately, detection of relevant symptoms and diagnosis based on heart sound through a stethoscope is difficult. The reason GPs find this difficult is that the heart sounds are of short duration and separated from one another by less than 30 ms. In addition, the cost of false positives constitutes wasted time and emotional anxiety for both patient and GP. Many heart diseases cause changes in heart sound, waveform, and additional murmurs before other signs and symptoms appear. Heart-sound auscultation is the primary test conducted by GPs. These sounds are generated primarily by turbulent flow of blood in the heart. Analysis of heart sounds requires a quiet environment with minimum ambient noise. In order to address such issues, the technique of denoising and estimating the biomedical heart signal is proposed in this investigation. Normally, the performance of the filter naturally depends on prior information related to the statistical properties of the signal and the background noise. This paper proposes Kalman filtering for denoising statistical heart sound. The cycles of heart sounds are certain to follow first-order Gauss-Markov process. These cycles are observed with additional noise for the given measurement. The model is formulated into state-space form to enable use of a Kalman filter to estimate the clean cycles of heart sounds. The estimates obtained by Kalman filtering are optimal in mean squared sense.

  14. Stochastic-Strength-Based Damage Simulation Tool for Ceramic Matrix and Polymer Matrix Composite Structures

    NASA Technical Reports Server (NTRS)

    Nemeth, Noel N.; Bednarcyk, Brett A.; Pineda, Evan J.; Walton, Owen J.; Arnold, Steven M.

    2016-01-01

    Stochastic-based, discrete-event progressive damage simulations of ceramic-matrix composite and polymer matrix composite material structures have been enabled through the development of a unique multiscale modeling tool. This effort involves coupling three independently developed software programs: (1) the Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC), (2) the Ceramics Analysis and Reliability Evaluation of Structures Life Prediction Program (CARES/ Life), and (3) the Abaqus finite element analysis (FEA) program. MAC/GMC contributes multiscale modeling capabilities and micromechanics relations to determine stresses and deformations at the microscale of the composite material repeating unit cell (RUC). CARES/Life contributes statistical multiaxial failure criteria that can be applied to the individual brittle-material constituents of the RUC. Abaqus is used at the global scale to model the overall composite structure. An Abaqus user-defined material (UMAT) interface, referred to here as "FEAMAC/CARES," was developed that enables MAC/GMC and CARES/Life to operate seamlessly with the Abaqus FEA code. For each FEAMAC/CARES simulation trial, the stochastic nature of brittle material strength results in random, discrete damage events, which incrementally progress and lead to ultimate structural failure. This report describes the FEAMAC/CARES methodology and discusses examples that illustrate the performance of the tool. A comprehensive example problem, simulating the progressive damage of laminated ceramic matrix composites under various off-axis loading conditions and including a double notched tensile specimen geometry, is described in a separate report.

  15. Production and properties of high strength Ni free Zr-based BMGs

    NASA Astrophysics Data System (ADS)

    Iqbal, M.; Wang, W. H.

    2014-06-01

    Bulk metallic glasses (BMGs) are well known for very attractive physical, mechanical and thermal properties. Zr-based BMGs are used as structural materials in sports goods, electronics, jewelry, medical and aerospace applications. Ni free Zr48Cu36Al8M8 (M = Nb, Ti and Ta) BMGs are successfully synthesized by Cu mold casting technique. Differential scanning calorimetery (DSC) results show that the Zr48Cu36Al8Nb8 BMG have good thermal stability, wide supercooled liquid region of 80 K and contain the double stage crystallization. The alloy has fracture strength of 1.953 GPa. Shear angle was measured to be in the range of 43.5±5° for the alloy studied. Vicker's hardness of the BMGs was found to be over 500 Hv for the as cast alloy which enhanced about 11 % more by annealing up to 600 °C/20 min. Intersected shear bands were observed. The observed promising mechanical and thermal properties showed that BMG studied can be used for industrial applications.

  16. Examining "success" in post-hip fracture care transitions: a strengths-based approach.

    PubMed

    Sims-Gould, Joanie; Byrne, Kerry; Hicks, Elisabeth; Khan, Karim; Stolee, Paul

    2012-05-01

    Transitions between health care settings are a high-risk period for care quality and patient safety (Coleman, 2003; Picker Institute, 1999), particularly for older patients - such as those with hip fracture - who have complex needs and may undergo multiple care transitions. We sought to understand the key elements of "success" in care transition. Using a strengths-based perspective (Rapp, 1998; Saleebey, 2006), we focused on interprofessional health care providers' perspectives of what constitutes a "good" care transition for elderly hip fracture patients. As part of a larger ethnographic field study, semi-structured interviews were conducted with 17 health providers across a number of disciplines employed across the continuum of post-hip fracture management in British Columbia, Canada. We found two hallmarks of "success" in care transitions: a focus on process - information gathering and communication, and a focus on outcomes - autonomy and care pathways. Strategies for promoting and improving success, such as using practitioner-driven ground-up solutions to address challenges in care transitions, are highlighted.

  17. Signal based motion compensation for synthetic aperture radar

    SciTech Connect

    John Kirk

    1999-06-07

    The purpose of the Signal Based Motion Compensation (SBMC) for Synthetic Aperture Radar (SAR) effort is to develop a method to measure and compensate for both down range and cross range motion of the radar in order to provide high quality focused SAR imagery in the absence of precision measurements of the platform motion. Currently SAR systems require very precise navigation sensors for motion compensation. These sensors are very expensive and are often supplied in pairs for reliability. In the case of GPS they can be jammed, further degrading performance. This makes for a potentially very expensive and possibly vulnerable SAR system. SBMC can eliminate or reduce the need for these expensive navigation sensors thus reducing the cost of budget minded SAR systems. The results on this program demonstrated the capability of the SBMC approach.

  18. A phase match based frequency estimation method for sinusoidal signals

    NASA Astrophysics Data System (ADS)

    Shen, Yan-Lin; Tu, Ya-Qing; Chen, Lin-Jun; Shen, Ting-Ao

    2015-04-01

    Accurate frequency estimation affects the ranging precision of linear frequency modulated continuous wave (LFMCW) radars significantly. To improve the ranging precision of LFMCW radars, a phase match based frequency estimation method is proposed. To obtain frequency estimation, linear prediction property, autocorrelation, and cross correlation of sinusoidal signals are utilized. The analysis of computational complex shows that the computational load of the proposed method is smaller than those of two-stage autocorrelation (TSA) and maximum likelihood. Simulations and field experiments are performed to validate the proposed method, and the results demonstrate the proposed method has better performance in terms of frequency estimation precision than methods of Pisarenko harmonic decomposition, modified covariance, and TSA, which contribute to improving the precision of LFMCW radars effectively.

  19. Convergent Validity of the Strength-Based Behavioral and Emotional Rating Scale with Youth in a Residential Setting.

    PubMed

    Duppong Hurley, Kristin; Lambert, Matthew C; Epstein, Michael H; Stevens, Amy

    2015-07-01

    Strength-based assessment has been identified as an appropriate approach to use in planning treatment and evaluating outcomes of youth in residential settings. In previous research, the Behavioral and Emotional Rating Scale-2, a standardized and norm-referenced strength-based measure, has demonstrated adequate reliability and validity with youth served in community and educational settings. The purpose of the present study was to examine the internal reliability and convergent validity of the BERS-2 by comparing the test to the Child Behavior Checklist and the Symptoms and Functioning Severity Scale. The results indicate that the scores from the BERS-2 are internally consistent and converge with other behavioral and emotional measures which, taken together, suggest that the BERS-2 could be acceptable for assessing the emotional and behavioral strengths of youth in residential settings. Study limitations and future research directions are identified.

  20. Flexural Strength of Acrylic Resin Denture Bases Processed by Two Different Methods

    PubMed Central

    Gharechahi, Jafar; Asadzadeh, Nafiseh; Shahabian, Foad; Gharechahi, Maryam

    2014-01-01

    Background and aims. The aim of this study was to compare flexural strength of specimens processed by conventional and injection-molding techniques. Materials and methods. Conventional pressure-packed PMMA was used for conventional pressure-packed and injection-molded PMMA was used for injection-molding techniques. After processing, 15 specimens were stored in distilled water at room temperature until measured. Three-point flexural strength test was carried out. Statistical analysis was carried out by SPSS using t-test. Statistical significance was defined at P<0.05. Results. Flexural strength of injection-polymerized acrylic resin specimens was higher than that of the conventional method (P=0.006). This difference was statistically significant (P=0.006). Conclusion. Within the limitations of this study, flexural strength of acrylic resin specimens was influenced by the molding technique. PMID:25346833

  1. Flexural strength of acrylic resin denture bases processed by two different methods.

    PubMed

    Gharechahi, Jafar; Asadzadeh, Nafiseh; Shahabian, Foad; Gharechahi, Maryam

    2014-01-01

    Background and aims. The aim of this study was to compare flexural strength of specimens processed by conventional and injection-molding techniques. Materials and methods. Conventional pressure-packed PMMA was used for conventional pressure-packed and injection-molded PMMA was used for injection-molding techniques. After processing, 15 specimens were stored in distilled water at room temperature until measured. Three-point flexural strength test was carried out. Statistical analysis was carried out by SPSS using t-test. Statistical significance was defined at P<0.05. Results. Flexural strength of injection-polymerized acrylic resin specimens was higher than that of the conventional method (P=0.006). This difference was statistically significant (P=0.006). Conclusion. Within the limitations of this study, flexural strength of acrylic resin specimens was influenced by the molding technique.

  2. Flexural strength of acrylic resin denture bases processed by two different methods.

    PubMed

    Gharechahi, Jafar; Asadzadeh, Nafiseh; Shahabian, Foad; Gharechahi, Maryam

    2014-01-01

    Background and aims. The aim of this study was to compare flexural strength of specimens processed by conventional and injection-molding techniques. Materials and methods. Conventional pressure-packed PMMA was used for conventional pressure-packed and injection-molded PMMA was used for injection-molding techniques. After processing, 15 specimens were stored in distilled water at room temperature until measured. Three-point flexural strength test was carried out. Statistical analysis was carried out by SPSS using t-test. Statistical significance was defined at P<0.05. Results. Flexural strength of injection-polymerized acrylic resin specimens was higher than that of the conventional method (P=0.006). This difference was statistically significant (P=0.006). Conclusion. Within the limitations of this study, flexural strength of acrylic resin specimens was influenced by the molding technique. PMID:25346833

  3. Multivariate classification of animal communication signals: a simulation-based comparison of alternative signal processing procedures using electric fishes.

    PubMed

    Crampton, William G R; Davis, Justin K; Lovejoy, Nathan R; Pensky, Marianna

    2008-01-01

    Evolutionary studies of communication can benefit from classification procedures that allow individual animals to be assigned to groups (e.g. species) on the basis of high-dimension data representing their signals. Prior to classification, signals are usually transformed by a signal processing procedure into structural features. Applications of these signal processing procedures to animal communication have been largely restricted to the manual or semi-automated identification of landmark features from graphical representations of signals. Nonetheless, theory predicts that automated time-frequency-based digital signal processing (DSP) procedures can represent signals more efficiently (using fewer features) than can landmark procedures or frequency-based DSP - allowing more accurate classification. Moreover, DSP procedures are objective in that they require little previous knowledge of signal diversity, and are relatively free from potentially ungrounded assumptions of cross-taxon homology. Using a model data set of electric organ discharge waveforms from five sympatric species of the electric fish Gymnotus, we adopted an exhaustive simulation approach to investigate the classificatory performance of different signal processing procedures. We considered a landmark procedure, a frequency-based DSP procedure (the fast Fourier transform), and two kinds of time-frequency-based DSP procedures (a short-time Fourier transform, and several implementations of the discrete wavelet transform -DWT). The features derived from each of these signal processing procedures were then subjected to dimension reduction procedures to separate those features which permit the most effective discrimination among groups of signalers. We considered four alternative dimension reduction methods. Finally, each combination of reduced data was submitted to classification by linear discriminant analysis. Our results support theoretical predictions that time-frequency DSP procedures (especially DWT

  4. Signal enhancement in cantilever magnetometry based on a co-resonantly coupled sensor.

    PubMed

    Körner, Julia; Reiche, Christopher F; Gemming, Thomas; Büchner, Bernd; Gerlach, Gerald; Mühl, Thomas

    2016-01-01

    Cantilever magnetometry is a measurement technique used to study magnetic nanoparticles. With decreasing sample size, the signal strength is significantly reduced, requiring advances of the technique. Ultrathin and slender cantilevers can address this challenge but lead to increased complexity of detection. We present an approach based on the co-resonant coupling of a micro- and a nanometer-sized cantilever. Via matching of the resonance frequencies of the two subsystems we induce a strong interplay between the oscillations of the two cantilevers, allowing for a detection of interactions between the sensitive nanocantilever and external influences in the amplitude response curve of the microcantilever. In our magnetometry experiment we used an iron-filled carbon nanotube acting simultaneously as nanocantilever and magnetic sample. Measurements revealed an enhancement of the commonly used frequency shift signal by five orders of magnitude compared to conventional cantilever magnetometry experiments with similar nanomagnets. With this experiment we do not only demonstrate the functionality of our sensor design but also its potential for very sensitive magnetometry measurements while maintaining a facile oscillation detection with a conventional microcantilever setup. PMID:27547621

  5. Signal enhancement in cantilever magnetometry based on a co-resonantly coupled sensor

    PubMed Central

    Körner, Julia; Reiche, Christopher F; Gemming, Thomas; Büchner, Bernd; Gerlach, Gerald

    2016-01-01

    Summary Cantilever magnetometry is a measurement technique used to study magnetic nanoparticles. With decreasing sample size, the signal strength is significantly reduced, requiring advances of the technique. Ultrathin and slender cantilevers can address this challenge but lead to increased complexity of detection. We present an approach based on the co-resonant coupling of a micro- and a nanometer-sized cantilever. Via matching of the resonance frequencies of the two subsystems we induce a strong interplay between the oscillations of the two cantilevers, allowing for a detection of interactions between the sensitive nanocantilever and external influences in the amplitude response curve of the microcantilever. In our magnetometry experiment we used an iron-filled carbon nanotube acting simultaneously as nanocantilever and magnetic sample. Measurements revealed an enhancement of the commonly used frequency shift signal by five orders of magnitude compared to conventional cantilever magnetometry experiments with similar nanomagnets. With this experiment we do not only demonstrate the functionality of our sensor design but also its potential for very sensitive magnetometry measurements while maintaining a facile oscillation detection with a conventional microcantilever setup. PMID:27547621

  6. Wavelet-based detection of transients in biological signals

    NASA Astrophysics Data System (ADS)

    Mzaik, Tahsin; Jagadeesh, Jogikal M.

    1994-10-01

    This paper presents two multiresolution algorithms for detection and separation of mixed signals using the wavelet transform. The first algorithm allows one to design a mother wavelet and its associated wavelet grid that guarantees the separation of signal components if information about the expected minimum signal time and frequency separation of the individual components is known. The second algorithm expands this idea to design two mother wavelets which are then combined to achieve the required separation otherwise impossible with a single wavelet. Potential applications include many biological signals such as ECG, EKG, and retinal signals.

  7. Scaling of strength and lifetime probability distributions of quasibrittle structures based on atomistic fracture mechanics.

    PubMed

    Bazant, Zdenek P; Le, Jia-Liang; Bazant, Martin Z

    2009-07-14

    The failure probability of engineering structures such as aircraft, bridges, dams, nuclear structures, and ships, as well as microelectronic components and medical implants, must be kept extremely low, typically <10(-6). The safety factors needed to ensure it have so far been assessed empirically. For perfectly ductile and perfectly brittle structures, the empirical approach is sufficient because the cumulative distribution function (cdf) of random material strength is known and fixed. However, such an approach is insufficient for structures consisting of quasibrittle materials, which are brittle materials with inhomogeneities that are not negligible compared with the structure size. The reason is that the strength cdf of quasibrittle structure varies from Gaussian to Weibullian as the structure size increases. In this article, a recently proposed theory for the strength cdf of quasibrittle structure is refined by deriving it from fracture mechanics of nanocracks propagating by small, activation-energy-controlled, random jumps through the atomic lattice. This refinement also provides a plausible physical justification of the power law for subcritical creep crack growth, hitherto considered empirical. The theory is further extended to predict the cdf of structural lifetime at constant load, which is shown to be size- and geometry-dependent. The size effects on structure strength and lifetime are shown to be related and the latter to be much stronger. The theory fits previously unexplained deviations of experimental strength and lifetime histograms from the Weibull distribution. Finally, a boundary layer method for numerical calculation of the cdf of structural strength and lifetime is outlined.

  8. Estimating the Concrete Compressive Strength Using Hard Clustering and Fuzzy Clustering Based Regression Techniques

    PubMed Central

    Nagwani, Naresh Kumar; Deo, Shirish V.

    2014-01-01

    Understanding of the compressive strength of concrete is important for activities like construction arrangement, prestressing operations, and proportioning new mixtures and for the quality assurance. Regression techniques are most widely used for prediction tasks where relationship between the independent variables and dependent (prediction) variable is identified. The accuracy of the regression techniques for prediction can be improved if clustering can be used along with regression. Clustering along with regression will ensure the more accurate curve fitting between the dependent and independent variables. In this work cluster regression technique is applied for estimating the compressive strength of the concrete and a novel state of the art is proposed for predicting the concrete compressive strength. The objective of this work is to demonstrate that clustering along with regression ensures less prediction errors for estimating the concrete compressive strength. The proposed technique consists of two major stages: in the first stage, clustering is used to group the similar characteristics concrete data and then in the second stage regression techniques are applied over these clusters (groups) to predict the compressive strength from individual clusters. It is found from experiments that clustering along with regression techniques gives minimum errors for predicting compressive strength of concrete; also fuzzy clustering algorithm C-means performs better than K-means algorithm. PMID:25374939

  9. The Power Card Strategy: Strength-Based Intervention to Increase Direction Following of Children with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Campbell, Abbi; Tincani, Matt

    2011-01-01

    The Power Card strategy is a strength-based intervention to promote social skills of children with autism spectrum disorders (ASD) by capitalizing on their special interests. Although preliminary studies have shown that the Power Card strategy is a promising approach to teach social skills, additional research is needed. The purpose of this study…

  10. Adaptive feed-forward loop connection based on error signal

    NASA Astrophysics Data System (ADS)

    Hidaka, Koichi

    2005-12-01

    In this paper, we investigate effect of changing the connection of feed-forward loop based on error signal. Our motivation of this work is solution to progress of human skill. For the skill model, we study a human simple action such as arm motion. Many models that describe the human arm dynamics have been proposed in recent year. While one type does not need an inverse model of human dynamics, the system based on the model does not include feed-forward loop. On the other hand, another type model has a feed-forward loop and feedback loop systems. This type assumes feed-forward element includes an internal model by repeating action or training and this loop progress our skill. Then we usually have to exercise to get a good performance. This says that we design the internal motion model by training and we move on prediction for motion. Under the assumption, Kawato model is well known. The model proposed that learning of feed-forward element is promoted in brain so that the error of feedback loop decreases. Furthermore, we assume the connections in feedback loop and feed-forward loop are changed. We show numerical simulations and consider that the position error given by our vision changes the skill element and we confirm that the position error is the one of the estimate function for the improvement in our skill.

  11. Rational Improvement of Molar Absorptivity Guided by Oscillator Strength: A Case Study with Furoindolizine-Based Core Skeleton.

    PubMed

    Lee, Youngjun; Jo, Ala; Park, Seung Bum

    2015-12-21

    The rational improvement of photophysical properties can be highly valuable for the discovery of novel organic fluorophores. Using our new design strategy guided by the oscillator strength, we developed a series of full-color-tunable furoindolizine analogs with improved molar absorptivity through the fusion of a furan ring into the indolizine-based Seoul fluorophore. The excellent correlation between the computable values (oscillator strength and theoretical S0 -S1 energy gap) and photophysical properties (molar absorptivity and emission wavelength) confirmed the effectualness of our design strategy.

  12. Field strength and dose dependence of contrast enhancement by gadolinium-based MR contrast agents.

    PubMed

    Rinck, P A; Muller, R N

    1999-01-01

    The relaxivities r1 and r2 of magnetic resonance contrast agents and the T1 relaxation time values of tissues are strongly field dependent. We present quantitative data and simulations of different gadolinium-based extracellular fluid contrast agents and the modulation of their contrast enhancement by the magnetic field to be able to answer the following questions: How are the dose and field dependences of their contrast enhancement? Is there an interrelationship between dose and field dependence? Should one increase or decrease doses at specific fields? Nuclear magnetic relaxation dispersion data were acquired for the following contrast agents: gadopentetate dimeglumine, gadoterate meglumine, gadodiamide injection, and gadoteridol injection, as well as for several normal and pathological human tissue samples. The magnetic field range stretched from 0.0002 to 4.7 T, including the entire clinical imaging range. The data acquired were then fitted with the appropriate theoretical models. The combination of the diamagnetic relaxation rates (R1 = 1/T1 and R2 = 1/T2) of tissues with the respective paramagnetic contributions of the contrast agents allowed the prediction of image contrast at any magnetic field. The results revealed a nearly identical field and dose-dependent increase of contrast enhancement induced by these contrast agents within a certain dose range. The target tissue concentration (TTC) was an important though nonlinear factor for enhancement. The currently recommended dose of 0.1 mmol/kg body weight seems to be a compromise close to the lower limits of diagnostically sufficient contrast enhancement for clinical imaging at all field strengths. At low field contrast enhancement might be insufficient. Adjustment of dose or concentration, or a new class of contrast agents with optimized relaxivity, would be a valuable contribution to a better diagnostic yield of contrast enhancement at all fields.

  13. The relationship between maximal lifting capacity and maximum acceptable lift in strength-based soldiering tasks.

    PubMed

    Savage, Robert J; Best, Stuart A; Carstairs, Greg L; Ham, Daniel J

    2012-07-01

    Psychophysical assessments, such as the maximum acceptable lift, have been used to establish worker capability and set safe load limits for manual handling tasks in occupational settings. However, in military settings, in which task demand is set and capable workers must be selected, subjective measurements are inadequate, and maximal capacity testing must be used to assess lifting capability. The aim of this study was to establish and compare the relationship between maximal lifting capacity and a self-determined tolerable lifting limit, maximum acceptable lift, across a range of military-relevant lifting tasks. Seventy male soldiers (age 23.7 ± 6.1 years) from the Australian Army performed 7 strength-based lifting tasks to determine their maximum lifting capacity and maximum acceptable lift. Comparisons were performed to identify maximum acceptable lift relative to maximum lifting capacity for each individual task. Linear regression was used to identify the relationship across all tasks when the data were pooled. Strong correlations existed between all 7 lifting tasks (rrange = 0.87-0.96, p < 0.05). No differences were found in maximum acceptable lift relative to maximum lifting capacity across all tasks (p = 0.46). When data were pooled, maximum acceptable lift was equal to 84 ± 8% of the maximum lifting capacity. This study is the first to illustrate the strong and consistent relationship between maximum lifting capacity and maximum acceptable lift for multiple single lifting tasks. The relationship developed between these indices may be used to help assess self-selected manual handling capability through occupationally relevant maximal performance tests.

  14. Design of high-strength recyclable graphene oxide-based porous composite for the removal of dyes

    NASA Astrophysics Data System (ADS)

    Jiao, Chenlu; Xiong, Jiaqing; Tao, Jin; Zhang, Desuo; Chen, Yuyue; Lin, Hong

    2015-06-01

    Graphene oxide-based composite (SSGO) with orderly pores was prepared by freeze-drying method. Its chemical structure, morphology and mechanical property were investigated. The results show that it has a unidirectional microporous structure which facilitates the diffusion of dyes. The incorporation of GO significantly improves the porous structure, and increases the compressive strength of SSGO. A 26.6 kPa increase and a 3 kPa improvement of strength in dry and wet states were achieved when 4 wt % GO was added. Moreover, the equilibrated adsorption capacity for methylene blue (MB) increased about 78.9%, up to 161 mg/g. With superior compressive strength and excellent adsorption capacity, the SSGO has promising recyclable application in dyes removal from wastewater.

  15. Strength and Durability of Fly Ash-Based Fiber-Reinforced Geopolymer Concrete in a Simulated Marine Environment

    NASA Astrophysics Data System (ADS)

    Martinez Rivera, Francisco Javier

    This research is aimed at investigating the corrosion durability of polyolefin fiberreinforced fly ash-based geopolymer structural concrete (hereafter referred to as GPC, in contradistinction to unreinforced geopolymer concrete referred to as simply geopolymer concrete), where cement is completely replaced by fly ash, that is activated by alkalis, sodium hydroxide and sodium silicate. The durability in a marine environment is tested through an electrochemical method for accelerated corrosion. The GPC achieved compressive strengths in excess of 6,000 psi. Fiber reinforced beams contained polyolefin fibers in the amounts of 0.1%, 0.3%, and 0.5% by volume. After being subjected to corrosion damage, the GPC beams were analyzed through a method of crack scoring, steel mass loss, and residual flexural strength testing. Fiber reinforced GPC beams showed greater resistance to corrosion damage with higher residual flexural strength. This makes GPC an attractive material for use in submerged marine structures.

  16. Influence of cubic boron nitride grinding on the fatigue strengths of carbon steels and a nickel-base superalloy

    SciTech Connect

    Kawagoishi, N.; Chen, Q.; Kondo, E.; Goto, M.; Nisitani, H.

    1999-04-01

    The influence of cubic boron nitride (CBN) grinding on fatigue strength was investigated on an annealed carbon steel, a quenched and tempered carbon steel at room temperature, and a nickel-base superalloy, Inconel 718, at room temperature and 500 C. The results were discussed from several viewpoints, including surface roughness, residual stress, and work hardening or softening due to CBN grinding. The fatigue strength increased upon CBN grinding at room temperature, primarily because of the generation of compressive residual stress in the surface region. However, in the case of Inconel 718, this marked increase in the fatigue strength tended to disappear at the elevated temperature due to the release of compressive residual stress and the decrease of crack growth resistance at an elevated temperature.

  17. Patient Insights Into the Design of Technology to Support a Strengths-Based Approach to Health Care

    PubMed Central

    Kristjansdottir, Olöf Birna; Stenberg, Una; Krogseth, Tonje; Stange, Kurt C; Ruland, Cornelia M

    2016-01-01

    Background An increasing number of research studies in the psychological and biobehavioral sciences support incorporating patients’ personal strengths into illness management as a way to empower and activate the patients, thus improving their health and well-being. However, lack of attention to patients’ personal strengths is still reported in patient–provider communication. Information technology (IT) has great potential to support strengths-based patient–provider communication and collaboration, but knowledge about the users’ requirements and preferences is inadequate. Objective This study explored the aspirations and requirements of patients with chronic conditions concerning IT tools that could help increase their awareness of their own personal strengths and resources, and support discussion of these assets in consultations with health care providers. Methods We included patients with different chronic conditions (chronic pain, morbid obesity, and chronic obstructive pulmonary disease) and used various participatory research methods to gain insight into the participants’ needs, values, and opinions, and the contexts in which they felt strengths-based IT tools could be used. Results Participants were positive toward using technology to support them in identifying and discussing their personal strengths in clinical consultation, but also underlined the importance of fitting it to their specific requirements and the right contexts of use. Participants recommended that technology be designed for use in preconsultation settings (eg, at home) and felt that it should support them in both identifying strengths and in finding out new ways how strengths can be used to attain personal health-related goals. Participants advocated use of technology to support advance preparation for consultations and empower them to take a more active role. IT tools were suggested to be potentially useful in specific contexts, including individual or group consultations with

  18. Fracture Strength of Aged Monolithic and Bilayer Zirconia-Based Crowns.

    PubMed

    Lameira, Deborah Pacheco; Buarque e Silva, Wilkens Aurélio; Andrade e Silva, Frederico; De Souza, Grace M

    2015-01-01

    The purpose of this study was to evaluate the effect of design and surface finishing on fracture strength of yttria-tetragonal zirconia polycrystal (Y-TZP) crowns in monolithic (1.5 mm thickness) and bilayer (0.8 mm zirconia coping and 0.7 mm porcelain veneer) configuration after artificial aging. Bovine incisors received crown preparation and Y-TZP crowns were manufactured using CAD/CAM technique, according to the following groups (n = 10): Polished monolithic zirconia crowns (PM); Glazed monolithic zirconia crowns (GM); Bi-layer crowns (BL). Crowns were cemented with resin cement, submitted to artificial aging in a chewing simulator (2.5 million cycles/80 N/artificial saliva/37 °C), and tested for fracture strength. Two remaining crowns referring to PM and GM groups were submitted to a chemical composition analysis to measure the level of yttrium after aging. One-way ANOVA and Tukey's test (P = .05) indicated that monolithic zirconia crowns presented similar fracture strength (PM = 3476.2 N ± 791.7; GM = 3561.5 N ± 991.6), which was higher than bilayer crowns (2060.4 N ± 810.6). There was no difference in the yttrium content among the three surfaces evaluated in the monolithic crowns. Thus, monolithic zirconia crowns present higher fracture strength than bilayer veneered zirconia after artificial aging and surface finishing does not affect their fracture strength. PMID:26576423

  19. EFFECT OF FLUORIDE-CONTAINING DESENSITIZING AGENTS ON THE BOND STRENGTH OF RESIN-BASED CEMENTS TO DENTIN

    PubMed Central

    Saraç, Duygu; Külünk, Safak; Saraç, Y. Sinasi; Karakas, Özlem

    2009-01-01

    Objective: The objective of this study was to evaluate the effect of desensitizing agents containing different amounts of fluoride on the shear bond strength of a dual polymerized resin cement and a resin-modified glass ionomer cement (RMGIC) to dentin. Material and Methods: One hundred human molars were mounted in acrylic resin blocks and prepared until the dentin surface was exposed. The specimens were treated with one of four desensitizing agents: Bifluorid 12, Fluoridin, Thermoline and PrepEze. The remaining 20 specimens served as untreated controls. All groups were further divided into 2 subgroups in which a dual polymerized resin cement (Bifix QM) or a resin-modified glass ionomer cement (AVANTO) was used. The shear bond strength (MPa) was measured using a universal testing machine at a 0.5 mm/min crosshead speed. The data were analyzed statistically with a 2-way ANOVA, Tukey HSD test and regression analysis (α=0.05). The effect of the desensitizing agents on the dentin surface was examined by scanning electron microscopy. Results: The fluoride-containing desensitizing agents affected the bond strength of the resin-based cements to dentin (p<0.001). PrepEze showed the highest bond strength values in all groups (p<0.001). Conclusion: Regression analysis showed a reverse relation between bond strength values of resin cements to dentin and the amount of fluoride in the desensitizing agent (p<0.05). PMID:19936532

  20. Biodegradable poly-lactic acid based-composite reinforced unidirectionally with high-strength magnesium alloy wires.

    PubMed

    Li, X; Chu, C L; Liu, L; Liu, X K; Bai, J; Guo, C; Xue, F; Lin, P H; Chu, Paul K

    2015-05-01

    Biodegradable poly-lactic acid (PLA)--based composites reinforced unidirectionally with high-strength magnesium alloy wires (MAWs) are fabricated by a heat-compressing process and the mechanical properties and degradation behavior are studied experimentally and theoretically. The composites possess improved strengthening and toughening properties. The bending strength and impact strength of the composites with 40 vol% MAWs are 190 MPa and 150 kJ/m(2), respectively, although PLA has a low viscosity and an average molecular weight of 60,000 g/mol. The mechanical properties of the composites can be further improved by internal structure modification and interface strengthening and a numerical model incorporating the equivalent section method (ESM) is proposed for the bending strength. Micro arc oxidization (MAO) of the MAWs is an effective interfacial strengthening method. The composites exhibit high strength retention during degradation and the PLA in the composite shows a smaller degradation rate than pure PLA. The novel biodegradable composites have large potential in bone fracture fixation under load-bearing conditions. PMID:25725562

  1. Noise texture and signal detectability in propagation-based x-ray phase-contrast tomography

    SciTech Connect

    Chou, Cheng-Ying; Anastasio, Mark A.

    2010-01-15

    Purpose: X-ray phase-contrast tomography (PCT) is a rapidly emerging imaging modality for reconstructing estimates of an object's three-dimensional x-ray refractive index distribution. Unlike conventional x-ray computed tomography methods, the statistical properties of the reconstructed images in PCT remain unexplored. The purpose of this work is to quantitatively investigate noise propagation in PCT image reconstruction. Methods: The authors derived explicit expressions for the autocovariance of the reconstructed absorption and refractive index images to characterize noise texture and understand how the noise properties are influenced by the imaging geometry. Concepts from statistical detection theory were employed to understand how the imaging geometry-dependent statistical properties affect the signal detection performance in a signal-known-exactly/background-known-exactly task. Results: The analytical formulas for the phase and absorption autocovariance functions were implemented numerically and compared to the corresponding empirical values, and excellent agreement was found. They observed that the reconstructed refractive images are highly spatially correlated, while the absorption images are not. The numerical results confirm that the strength of the covariance is scaled by the detector spacing. Signal detection studies were conducted, employing a numerical observer. The detection performance was found to monotonically increase as the detector-plane spacing was increased. Conclusions: The authors have conducted the first quantitative investigation of noise propagation in PCT image reconstruction. The reconstructed refractive images were found to be highly spatially correlated, while absorption images were not. This is due to the presence of a Fourier space singularity in the reconstruction formula for the refraction images. The statistical analysis may facilitate the use of task-based image quality measures to further develop and optimize this emerging

  2. Flexural strength,water sorption and solubility of a methylmethacrylate-free denture base polymer reinforced with glass fibre reinforcement.

    PubMed

    Mutluay, M M; Tezvergil-Mutluay, A; Vallittu, P; Lassila, L

    2013-12-01

    A methylmethacrylate-free denture base polymer (Eclipse) in comparison to a conventional denture base polymer (Palapress vario) was evaluated after water saturation and Stick glass fibre reinforcement. The data were analysed with ANOVA at a = 0.05. Water-storage caused a decrease in the flexural strength and stiffness of the materials (p > 0.05). Conventional denture base material with fibre reinforcement gave highest flexural strength (201.1 MPa) compared to fibre reinforced Eclipse (79.1 MPa) (p < 0.05). Water sorption after 76 days was 2.08% (Palapress vario) and 1.55% (Eclipse). Fibre-reinforcement of methylmethacrylate-free material was not as successful as conventional denture base and needs to be further optimized.

  3. Bond strength of acrylic teeth to denture base resin after various surface conditioning methods before and after thermocycling.

    PubMed

    Saavedra, Guilherme; Valandro, Luiz Felipe; Leite, Fabiola Pessoa Pereira; Amaral, Regina; Ozcan, Mutlu; Bottino, Marco A; Kimpara, Estevão T

    2007-01-01

    This study aimed to evaluate the durability of adhesion between acrylic teeth and denture base acrylic resin. The base surfaces of 24 acrylic teeth were flatted and submitted to 4 surface treatment methods: SM1 (control): No SM; SM2: application of a methyl methacrylate-based bonding agent (Vitacol); SM3: air abrasion with 30-microm silicone oxide plus silane; SM4: SM3 plus SM2. A heat-polymerized acrylic resin was applied to the teeth. Thereafter, bar specimens were produced for the microtensile test at dry and thermocyled conditions (60 days water storage followed by 12,000 cycles). The results showed that bond strength was significantly affected by the SM (P < .0001) (SM4 = SM2 > SM3 > SM1) and storage regimens (P < .0001) (dry > thermocycled). The methyl methacrylate-based adhesive showed the highest bond strength. PMID:17455445

  4. Evaluation of Surface Roughness and Tensile Strength of Base Metal Alloys Used for Crown and Bridge on Recasting (Recycling)

    PubMed Central

    Hashmi, Syed W.; Rao, Yogesh; Garg, Akanksha

    2015-01-01

    Background Dental casting alloys play a prominent role in the restoration of the partial dentition. Casting alloys have to survive long term in the mouth and also have the combination of structure, molecules, wear resistance and biologic compatibility. According to ADA system casting alloys were divided into three groups (wt%); high noble, Noble and predominantly base metal alloys. Aim To evaluate the mechanical properties such as tensile strength and surface roughness of the new and recast base metal (nickel-chromium) alloys. Materials and Methods Recasting of the base metal alloys derived from sprue and button, to make it reusable has been done. A total of 200 test specimens were fabricated using specially fabricated jig of metal and divided into two groups- 100 specimens of new alloy and 100 specimens of recast alloys, which were tested for tensile strength on universal testing machine and surface roughness on surface roughness tester. Results Tensile strength of new alloy showed no statistically significant difference (p-value>0.05) from recast alloy whereas new alloy had statistically significant surface roughness (Maximum and Average surface roughness) difference (p-value<0.01) as compared to recast alloy. Conclusion Within the limitations of the study it is concluded that the tensile strength will not be affected by recasting of nickel-chromium alloy whereas surface roughness increases markedly. PMID:26393194

  5. A 16-Bit Microcomputer Based Biomedical Signal Processor

    PubMed Central

    Sarkady, Antal A.; Wallingford, Errol E.

    1979-01-01

    A versatile low-cost, two-channel signal processor was developed using a 16-bit microcomputer. The instrument can process biomedical signals in the time and frequency domains using a fast, fixed-point FFT algorithm. Many averaged signal processing functions and their estimates are computed efficiently on-line and in near real time using look-up tables and directives. The signal processing techniques were applied to phonocardiograms to develop a non-invasive technique to assess the severity of valvar aortic stenosis in children. A murmur power spectral analysis is presented which yields a statistically reliable spectrum. Envelograms are defined and found to be useful for timing cardiac events.

  6. Shear Bond Strengths of Methacrylate- and Silorane-based Composite Resins to Feldspathic Porcelain using Different Adhesive Systems.

    PubMed

    Mohammadi, Narmin; Shakur Shahabi, Maryam; Kimyai, Soodabeh; Pournagi Azar, Fatemeh; Ebrahimi Chaharom, Mohammad Esmaeel

    2015-01-01

    Background and aims. Use of porcelain as inlays, laminates and metal-ceramic and all-ceramic crowns is common in modern dentistry. The high cost of ceramic restorations, time limitations and difficulty of removing these restorations result in delays in replacing fractured restorations; therefore, their repair is indicated. The aim of the present study was to compare the shear bond strengths of two types of composite resins (methacrylate-based and silorane-based) to porcelain, using three adhesive types. Materials and methods. A total of 156 samples of feldspathic porcelain surfaces were prepared with air-abrasion and randomly divided into 6 groups (n=26). In groups 1-3, Z250 composite resin was used to repair porcelain samples with Ad-per Single Bond 2 (ASB), Clearfil SE Bond (CSB) and Silorane Adhesive (SA) as the bonding systems, afterapplication of silane, respectively. In groups 4-6, the same adhesives were used in the same manner with Filtek Silorane composite resin. Finally, the shear bond strengths of the samples were measured. Two-way ANOVA and post hoc Tukey tests were used to compare bond strengths between the groups with different adhesives at P<0.05. Results. There were significant differences in the mean bond strength values in terms of the adhesive type (P<0.001). In addition, the interactive effect of the adhesive type and composite resin type had no significant effect on bond strength (P=0.602). Conclusion. The results of the present study showed the highest repair bond strength values to porcelain with both composite resin types with the application of SA and ASB. PMID:26697151

  7. Shear Bond Strengths of Methacrylate- and Silorane-based Composite Resins to Feldspathic Porcelain using Different Adhesive Systems

    PubMed Central

    Mohammadi, Narmin; Shakur Shahabi, Maryam; Kimyai, Soodabeh; Pournagi Azar, Fatemeh; Ebrahimi Chaharom, Mohammad Esmaeel

    2015-01-01

    Background and aims. Use of porcelain as inlays, laminates and metal-ceramic and all-ceramic crowns is common in modern dentistry. The high cost of ceramic restorations, time limitations and difficulty of removing these restorations result in delays in replacing fractured restorations; therefore, their repair is indicated. The aim of the present study was to compare the shear bond strengths of two types of composite resins (methacrylate-based and silorane-based) to porcelain, using three adhesive types. Materials and methods. A total of 156 samples of feldspathic porcelain surfaces were prepared with air-abrasion and randomly divided into 6 groups (n=26). In groups 1-3, Z250 composite resin was used to repair porcelain samples with Ad-per Single Bond 2 (ASB), Clearfil SE Bond (CSB) and Silorane Adhesive (SA) as the bonding systems, afterapplication of silane, respectively. In groups 4-6, the same adhesives were used in the same manner with Filtek Silorane composite resin. Finally, the shear bond strengths of the samples were measured. Two-way ANOVA and post hoc Tukey tests were used to compare bond strengths between the groups with different adhesives at P<0.05. Results. There were significant differences in the mean bond strength values in terms of the adhesive type (P<0.001). In addition, the interactive effect of the adhesive type and composite resin type had no significant effect on bond strength (P=0.602). Conclusion. The results of the present study showed the highest repair bond strength values to porcelain with both composite resin types with the application of SA and ASB. PMID:26697151

  8. Effect of Metakaolin on Strength and Efflorescence Quantity of Cement-Based Composites

    PubMed Central

    Weng, Tsai-Lung; Lin, Wei-Ting; Cheng, An

    2013-01-01

    This study investigated the basic mechanical and microscopic properties of cement produced with metakaolin and quantified the production of residual white efflorescence. Cement mortar was produced at various replacement ratios of metakaolin (0, 5, 10, 15, 20, and 25% by weight of cement) and exposed to various environments. Compressive strength and efflorescence quantify (using Matrix Laboratory image analysis and the curettage method), scanning electron microscopy, and X-ray diffraction analysis were reported in this study. Specimens with metakaolin as a replacement for Portland cement present higher compressive strength and greater resistance to efflorescence; however, the addition of more than 20% metakaolin has a detrimental effect on strength and efflorescence. This may be explained by the microstructure and hydration products. The quantity of efflorescence determined using MATLAB image analysis is close to the result obtained using the curettage method. The results demonstrate the best effectiveness of replacing Portland cement with metakaolin at a 15% replacement ratio by weight. PMID:23737719

  9. Effect of metakaolin on strength and efflorescence quantity of cement-based composites.

    PubMed

    Weng, Tsai-Lung; Lin, Wei-Ting; Cheng, An

    2013-01-01

    This study investigated the basic mechanical and microscopic properties of cement produced with metakaolin and quantified the production of residual white efflorescence. Cement mortar was produced at various replacement ratios of metakaolin (0, 5, 10, 15, 20, and 25% by weight of cement) and exposed to various environments. Compressive strength and efflorescence quantify (using Matrix Laboratory image analysis and the curettage method), scanning electron microscopy, and X-ray diffraction analysis were reported in this study. Specimens with metakaolin as a replacement for Portland cement present higher compressive strength and greater resistance to efflorescence; however, the addition of more than 20% metakaolin has a detrimental effect on strength and efflorescence. This may be explained by the microstructure and hydration products. The quantity of efflorescence determined using MATLAB image analysis is close to the result obtained using the curettage method. The results demonstrate the best effectiveness of replacing Portland cement with metakaolin at a 15% replacement ratio by weight.

  10. Historical Chronology of ENSO Events Based Upon Documentary Data From South America: Strengths and Limitations

    NASA Astrophysics Data System (ADS)

    Luc, O.

    2007-05-01

    sequence deal with the non-homogeneity of the documentary records, the reconstruction of the paleo-events strength and the difficulty to cross check documentary data with other annually resolved records (corals, tree-rings and ice-core data). In spite of all these limitations, the documentation of former EN occurrences based upon written archives from colonial South-America remains an unavoidable and powerful tool to reconstruct a solid El Niño chronology for the last half millennium and to better understand the interplay of the different modes (at the interannual, decadal, multidecadal and centennial scales) of climate variations in this part of the world.

  11. Effect of Preheating and Precooling on the Flexural Strength and Modulus of Elasticity of Nanohybrid and Silorane-based Composite

    PubMed Central

    Sharafeddin, Farahnaz; Motamedi, Mehran; Fattah, Zahra

    2015-01-01

    Statement of the Problem Composite resin may be used in different temperatures; it is crucial to determine the effect of temperature on mechanical properties of nanohybrid and silorane-based composite. Purpose This in vitro study compared the flexural strength and modulus of elasticity of nanohybrid and silorane-based resin composite, at 4˚C, room temperature (25˚C), and 45˚C. Materials and Method In this experimental study, 60 specimens were prepared in a metal split mold (2×2×25mm). Two different resin composites, Filtek Z250 XT (3M/ ESPE) and Filtek P90 (3M/ESPE), were evaluated. The material were inserted into split molds at room temperature, 4˚C or 45˚C and cured with LED (1200 mW/cm2) for 20 seconds in four points (n=10). Then, a three-point bending test was performed using a universal testing machine at a crosshead speed of 0.5 mm/min for measuring the flexural strength and flexural modulus of samples. The data were analyzed by the two-way ANOVA and Tukey test (p< 0.05). Results The mean highest flexural strength was observed at 45˚C, showing statistically significant difference with flexural strength at 4˚C (p= 0.0001) and 25˚C (p= 0.003) regardless of the type of resin composite. The flexural modulus at 45˚C was highest, showing the statistically significant difference with flexural modulus at 4˚C (p= 0.0001) and 25˚C (p= 0.002). The flexural modulus was statistically different between nanohybrid and silorane-based resin composite (p= 0.01) in 25˚C and 45˚C, but there were no statistically significant differences between flexural strength of Filtek Z250 XT and Filtek P90 regardless of the temperatures (p= 0.062). Conclusion Preheating the resin composite at 45˚C improves flexural strength and modulus of nanohybrid and silorane-based resin composite. However, flexural strength and modulus of the tested materials were not affected by precooling. The flexural modulus of nanohybrid resin composite was significantly higher than silorane-based

  12. What Is a Strength?

    ERIC Educational Resources Information Center

    Wolin, Sybil

    2003-01-01

    As the strength-based perspective gains recognition, it is important to describe what constitutes strengths and to develop a specific vocabulary to name them. This article draws on resilience research to help identify specific competencies and areas of strengths in youth. (Contains 1 table.)

  13. Rupture Strength of Several Nickel-base Alloys in Sheet Form

    NASA Technical Reports Server (NTRS)

    Dance, James H; Clauss, Francis J

    1957-01-01

    The 100-hour rupture strengths of Inconel X, Inconel 700, Incoloy 901, Refractaloy 26, and R-235 at 1200 and 1350 F. in both the annealed and heat-treated conditions were determined. Inconel 700 had the highest rupture strength at both temperatures; Incoloy 901 was second strongest at 1200 F, and R-235 second strongest at 1350 F. With the exception of Incoloy 901, ductility was low. Photomicrographs show that fractures are through the grain boundaries. Results are compared with published data for other sheet alloys and bar stock.

  14. Variable Time Base Integrator Circuit for Buffet Signal Measurements

    NASA Technical Reports Server (NTRS)

    Batts, Colossie N.

    1973-01-01

    A measurement circuit to obtain buffet data from wind tunnel models wherein a signal proportional to the average RMS value of buffet data is produced for subsequent recording. Feedback means are employed to suppress the D.C. portion of signals developed by the strain gages during dynamic testing. Automatic recording of gain settings of amplifiers employed in the circuit is also provided.

  15. A fundamental understanding of the dependence of the laser-induced breakdown spectroscopy (LIBS) signal strength on the complex focusing dynamics of femtosecond laser pulses on either side of the focus.

    PubMed

    Zuhlke, Craig A; Bruce, John; Anderson, Troy P; Alexander, Dennis R; Parigger, Christian G

    2014-01-01

    We correlate the focusing dynamics of 50 femtosecond (fs) laser radiation as it interacts with a silicon sample to laser-induced breakdown spectroscopy (LIBS) signal strength. Presented are concentric ring-shaped variations in the electric field in the prefocus region due to lens aberrations and nonsymmetry between the prefocus and post-focus beam profile as a result of continuum generation, occurring around the focus. Experimental results show different signal trends for both atmospheric and vacuum conditions, attributed to the existence of a continuum for the former. Lens aberrations effects on the LIBS signal strength are investigated using a plano-convex spherical lens and an aspherized achromatic lens. High-resolution scanning electron micrographs of the silicon surface after ablation, along with theoretical simulations, reveal the electric field patterns near the focus. The research results contribute to fundamental understanding of the basic physics of ultrashort, femtosecond laser radiation interacting with materials. PMID:25226256

  16. Effect of Mechanical Surface Treatment on the Repair Bond Strength of the Silorane-based Composite Resin

    PubMed Central

    Alizadeh Oskoee, Parnian; Kimyai, Soodabeh; Talatahari, Elham; Rikhtegaran, Sahand; Pournaghi-Azar, Fatemeh; Sajadi Oskoee, Jafar

    2014-01-01

    Background and aims. A proper bond must be created between the existing composite resin and the new one for successful repair. The aim of this study was to compare the effect of three mechanical surface treatments, using diamond bur, air abrasion, and Er,Cr:YSGG laser, on the repair bond strength of the silorane-based composite resin. Materials and methods. Sixty cylindrical composite resin specimens (Filtek Silorane) were fabricated and randomly divided into four groups according to surface treatment: group 1 (control group) without any mechanical surface treatment, groups 24 were treated with air abrasion, Er,Cr:YSGG laser, and diamond bur, respectively. In addition, a positive control group was assigned in order to measure the cohesive strength. Silorane bonding agent was used in groups 14 before adding the new composite resin. Then, the specimens were subjected to a shear bond strength test and data was analyzed using one-way ANOVA and post hoc Tukey tests at a significance level of P &0.05. The topographical effects of surface treatments were characterized under a scanning electron microscope. Results. There were statistically significant differences in the repair bond strength values between groups 1 and 2 and groups 3 and 4 (P &0.001). There were no significant differences between groups 1 and 2 (P = 0.98) and groups 3 and 4 (P= 0.97). Conclusion. Surface treatment using Er,Cr:YSGG laser and diamond bur were effective in silorane-based composite resin repair. PMID:25093047

  17. Student-Driven Interviewing: Practical Strategies for Building Strength-Based Interventions

    ERIC Educational Resources Information Center

    Murphy, John J.

    2013-01-01

    The principles and practices of positive psychology are gaining wider acceptance among school psychologists (Gilman, Huebner, & Furlong, 2009). Unlike traditional assessment and intervention practices that focus primarily on what is wrong and missing with students, positive practices focus on what is right and working with students--strengths,…

  18. Impact of zeolite-based nanomodified additive on the structure and strength of the cement stone

    NASA Astrophysics Data System (ADS)

    Egorova, A. D.; Filippova, K. E.

    2015-01-01

    Portland cement is the main binder in the building materials industry; its properties strongly influence properties of mortars and concretes. Some regions experience difficulties with delivery and storage of Portland cement, raising the need to develop an effective additive from the available raw materials. Such materials for the Republic of Sakha (Yakutia) are zeolite-containing rocks. Studies have shown that introducing of dibutylphthalate to the composition of modified additive during mechanochemical activation leads to achievement of up to 11% of total amount particles with the size of 3-30 nm. After introducing 0.5% of the obtained additives, the compressive strength of cement-sand slurry samples increases up to 28%. Positive effect of additives introduction is also observed at high flow rate of water (W / C = 0.7). Gaining strength reaches 23%, allowing the efficient use of additive for movable mixtures with enhanced strength properties. In general, the proposed supplement allows reducing the water flow in the solution without decreasing its mobility, and increasing strength properties, which makes it possible to obtain a whole class of solutions of modified cement binder. The market value of the developed additives is 18 rubles per 1 kg, making sound competition in the market of modifying additives.

  19. Ni.sub.3 Al-based intermetallic alloys having improved strength above 850.degree. C.

    DOEpatents

    Liu, Chain T.

    2000-01-01

    Intermetallic alloys composed essentially of: 15.5% to 17.0% Al, 3.5% to 5.5% Mo, 4% to 8% Cr, 0.04% to 0.2% Zr, 0.04% to 1.5% B, balance Ni, are characterized by melting points above 1200.degree. C. and superior strengths at temperatures above 1000.degree. C.

  20. Fracture Strength of Aged Monolithic and Bilayer Zirconia-Based Crowns

    PubMed Central

    Lameira, Deborah Pacheco; Silva, Wilkens Aurélio Buarque e; Silva, Frederico Andrade e; De Souza, Grace M.

    2015-01-01

    The purpose of this study was to evaluate the effect of design and surface finishing on fracture strength of yttria-tetragonal zirconia polycrystal (Y-TZP) crowns in monolithic (1.5 mm thickness) and bilayer (0.8 mm zirconia coping and 0.7 mm porcelain veneer) configuration after artificial aging. Bovine incisors received crown preparation and Y-TZP crowns were manufactured using CAD/CAM technique, according to the following groups (n = 10): Polished monolithic zirconia crowns (PM); Glazed monolithic zirconia crowns (GM); Bi-layer crowns (BL). Crowns were cemented with resin cement, submitted to artificial aging in a chewing simulator (2.5 million cycles/80 N/artificial saliva/37°C), and tested for fracture strength. Two remaining crowns referring to PM and GM groups were submitted to a chemical composition analysis to measure the level of yttrium after aging. One-way ANOVA and Tukey's test (P = .05) indicated that monolithic zirconia crowns presented similar fracture strength (PM = 3476.2 N ± 791.7; GM = 3561.5 N ± 991.6), which was higher than bilayer crowns (2060.4 N ± 810.6). There was no difference in the yttrium content among the three surfaces evaluated in the monolithic crowns. Thus, monolithic zirconia crowns present higher fracture strength than bilayer veneered zirconia after artificial aging and surface finishing does not affect their fracture strength. PMID:26576423

  1. Reliability, failure probability, and strength of resin-based materials for CAD/CAM restorations

    PubMed Central

    Lim, Kiatlin; Yap, Adrian U-Jin; Agarwalla, Shruti Vidhawan; Tan, Keson Beng-Choon; Rosa, Vinicius

    2016-01-01

    ABSTRACT Objective: This study investigated the Weibull parameters and 5% fracture probability of direct, indirect composites, and CAD/CAM composites. Material and Methods: Discshaped (12 mm diameter x 1 mm thick) specimens were prepared for a direct composite [Z100 (ZO), 3M-ESPE], an indirect laboratory composite [Ceramage (CM), Shofu], and two CAD/CAM composites [Lava Ultimate (LU), 3M ESPE; Vita Enamic (VE), Vita Zahnfabrik] restorations (n=30 for each group). The specimens were polished, stored in distilled water for 24 hours at 37°C. Weibull parameters (m= modulus of Weibull, σ0= characteristic strength) and flexural strength for 5% fracture probability (σ5%) were determined using a piston-on-three-balls device at 1 MPa/s in distilled water. Statistical analysis for biaxial flexural strength analysis were performed either by both one-way ANOVA and Tukey's post hoc (α=0.05) or by Pearson's correlation test. Results: Ranking of m was: VE (19.5), LU (14.5), CM (11.7), and ZO (9.6). Ranking of σ0 (MPa) was: LU (218.1), ZO (210.4), CM (209.0), and VE (126.5). σ5% (MPa) was 177.9 for LU, 163.2 for CM, 154.7 for Z0, and 108.7 for VE. There was no significant difference in the m for ZO, CM, and LU. VE presented the highest m value and significantly higher than ZO. For σ0 and σ5%, ZO, CM, and LU were similar but higher than VE. Conclusion: The strength characteristics of CAD/ CAM composites vary according to their composition and microstructure. VE presented the lowest strength and highest Weibull modulus among the materials. PMID:27812614

  2. Evaluation of the strengths and weaknesses of community-based education from the viewpoint of students

    PubMed Central

    MOKHTARPOUR, SEDIGHEH; AMINI, MITRA; MOUSAVINEZHAD, HOURI; CHOOBINEH, ALIREZA; NABEIEI, PARISA

    2016-01-01

    Introduction: Responsive medicine is an appropriate training method which trains the graduates who can act effectively in initial and secondary aspects of health issues in the society. Methods: This was a cross-sectional descriptive-analytic study which was done using quantitative method. The target population of this study was all the students of the Nutrition and Health School of Shiraz University of Medical Sciences. The sample was randomly selected in this study and 75 students were selected based on the methodologist’s comments and similar studies and random-number table from a list obtained from the school’s department of education. This questionnaire was a researcher-made one which consisted of 23 questions in 2 sections with 21 closed-ended questions and 2 open-ended questions; 70 questionnaires were completed correctly. The closed-ended questions had 4 aspects (completely agree to completely disagree) answered in 5-point Likert scale type. Its face validity was confirmed by 4 faculty members. The construct validity of the questionnaire was analyzed by factor analysis test and its reliability was assessed by a pilot on 20 students with a Cronbach’s alpha of 0.85. The data were analyzed using descriptive statistical tests (mean, standard deviation, …) and the Pearson coefficient (p<0.001). Results: The results of this study showed that the maximum mean score was 3.58±0.65 which was related to the context of these courses and the minimum mean was 2.66±1.14 which was related to the logbook implementation. The 2 open-ended questions indicated that the most important strengths were the use of logbooks as a guide and determining the minimum training; of the weaknesses was the mismatch between the theoretical education and the practical activities. Also, developing the minimum training that an expert should know and using the common topics related to theoretical education were the most important points mentioned by the respondents. Conclusions: The

  3. Subauditory Speech Recognition based on EMG/EPG Signals

    NASA Technical Reports Server (NTRS)

    Jorgensen, Charles; Lee, Diana Dee; Agabon, Shane; Lau, Sonie (Technical Monitor)

    2003-01-01

    Sub-vocal electromyogram/electro palatogram (EMG/EPG) signal classification is demonstrated as a method for silent speech recognition. Recorded electrode signals from the larynx and sublingual areas below the jaw are noise filtered and transformed into features using complex dual quad tree wavelet transforms. Feature sets for six sub-vocally pronounced words are trained using a trust region scaled conjugate gradient neural network. Real time signals for previously unseen patterns are classified into categories suitable for primitive control of graphic objects. Feature construction, recognition accuracy and an approach for extension of the technique to a variety of real world application areas are presented.

  4. [Study on neurofeedback system based on electroencephalogram signals].

    PubMed

    Pu, Xianjie; Liu, Tiejun; Wu, Qiang; Zhang, Rui; Xu, Peng; Li, Ke; Xia, Yang; Yao, Dezhong

    2014-08-01

    Neurofeedback, as an alternative treatment method of behavioral medicine, is a technique which translates the electroencephalogram (EEG) signals to styles as sounds or animation to help people understand their own physical status and learn to enhance or suppress certain EEG signals to regulate their own brain functions after several repeated trainings. This paper develops a neurofeedback system on the foundation of brain-computer interface technique. The EEG features are extracted through real-time signal process and then translated to feedback information. Two feedback screens are designed for relaxation training and attention training individually. The veracity and feasibility of the neurofeedback system are validated through system simulation and preliminary experiment. PMID:25464809

  5. Effect of curing cycle on the tensile strength of the bond between heat cured denture base acrylic resin and acrylic resin denture teeth.

    PubMed

    Dalal, Ayesha; Juszczyk, Andrzej S; Radford, David R; Clark, Robert K F

    2009-12-01

    The effect of different curing cycles on the tensile strength of the bond between one brand of cross-linked acrylic resin teeth and three heat cured denture base acrylic resins was tested. There were differences in the tensile bond strength between the three heat cured denture base acrylic resins and the three curing cycles used. The bond strength of the acrylic resin denture base material made by the same manufacturer as the cross-linked acrylic resin denture teeth was higher. The bond strength following the short cycle was lowest in all cases, individual differences between curing cycles failed to reach statistical significance. PMID:20158054

  6. Effect of surface treatments on the bond strength of different resin teeth to complete denture base material.

    PubMed

    Meloto, Carolina B; Silva-Concílio, Laís R; Rodrigues-Garciai, Renata C M; Canales, Giancarlo T; Rizzatti-Barbosa, Célia M

    2013-01-01

    Although different commercial brands of artificial teeth are available in the market, debonding from the denture base is still an issue when rehabilitating edentulous patients with conventional or implant-supported complete dentures. The purpose of this study was to investigate the effect of surface treatments on the bond strength of four artificial teeth brands to a denture base material polymerized by microwave energy. Forty anterior artificial teeth of each brand (Biolux, Trilux, Biotone IPN, and Vipi Dent Plus) were bonded to denture base material (VipiWave). Before processing, groups often specimens of each brand received surface treatment: control, monomer application (MA), air abrasion (AA) or diatoric cavity (DC). After processing, a blinded examiner conducted the bond test by applying load to the specimens (0.5 mm/min, to 45 degrees). Data were analyzed by one-way ANOVA followed by Tukey's test (alpha = 0.05). Biolux teeth have stronger bonding to denture base than Trilux (p < 0.05) in control group; higher bond values than Biotone IPN (p < 0.05) in MA group; and higher bond strength than Vipi Dent Plus and Trilux (p < 0.01) in DC group; AA had no differential effect for any of the brands. With regard to the effect of the surface treatments on bond strength within groups of commercial brand, statistical analysis revealed no difference among them. According to results in general, Biolux teeth had the strongest bonding to the denture base material polymerized by microwave energy. Results may assist dentists in selecting denture teeth from the standpoint of shear bond strength.

  7. Market-Based Manpower Planning with Labour Market Signals.

    ERIC Educational Resources Information Center

    Van Adams, Arvil; And Others

    1992-01-01

    Labor market planning techniques must take into account the dynamic nature of economies. A better approach than labor needs forecasting is use of labor market signals developed by monitoring wage and employment changes and evaluating training programs. (SK)

  8. Co-cured composite joint strength investigation based on behavior characterization of the [0/ (+/-)theta/90]s family

    NASA Astrophysics Data System (ADS)

    Tan, Xinyuan

    Joints provide a path for transfer of load and are important components in an assembly of structures, particularly in translating joint strength improvements directly to significant cost savings. These cost savings are more evident in composite joints since manufacturing of more complex single piece components results in a reduction of both part count and labor. An improvement in joint strength for co-cured composite joints through minimized free-edge delamination was investigated for a quasi-isotropic [0/ +/- 45/90]s lay-up based on the quantitative assessments of the quasi-static and fatigue strength and qualitative understanding of the fatigue damage initiation and propagation for the [0/ +/- theta/90]s family of co-cured composite joints. A previously proposed co-cured joint concept, the Single Nested Overlap (SNO) joint, was compared against a Straight Laminate (SL) and a single lap joint. The SL represents a "perfect" joint and serves as an upper bound whereas the single lap joint represents the simplest generic joint and is the base design for the SNO joint concept. Three categorized failure types, which represent the predominant failure modes in the SL, single lap, and SNO joints, along with two different fatigue strength indicators were used for quasi-static and fatigue strength comparison. With fatigue run-out defined at 1x106 cycles, the fatigue damage initiation and propagation at high loadings was monitored with an Infrared Thermoelastic Stress Analysis (IR-TSA) technique, while a damage type comparison was used at low loadings. Quasi-static Acoustic Emission (AE) counts were observed to be Fatigue Limit (FL) indicators for [0/ +/- theta/90] s SL and SNO joints. The validity of these FL indicators was also assessed in the comparison of damage types.

  9. Effect of hydrofluoric acid etching duration on the roughness and flexural strength of a lithium disilicate-based glass ceramic.

    PubMed

    Zogheib, Lucas Villaça; Bona, Alvaro Della; Kimpara, Estevão Tomomitsu; McCabe, John F

    2011-01-01

    The aim of this study was to examine the effect of different acid etching times on the surface roughness and flexural strength of a lithium disilicate-based glass ceramic. Ceramic bar-shaped specimens (16 mm x 2 mm x 2 mm) were produced from ceramic blocks. All specimens were polished and sonically cleaned in distilled water. Specimens were randomly divided into 5 groups (n=15). Group A (control) no treatment. Groups B-E were etched with 4.9% hydrofluoric acid (HF) for 4 different etching periods: 20 s, 60 s, 90 s and 180 s, respectively. Etched surfaces were observed under scanning electron microscopy. Surface profilometry was used to examine the roughness of the etched ceramic surfaces, and the specimens were loaded to failure using a 3-point bending test to determine the flexural strength. Data were analyzed using one-way ANOVA and Tukey's test (?=0.05). All etching periods produced significantly rougher surfaces than the control group (p<0.05). Roughness values increased with the increase of the etching time. The mean flexural strength values were (MPa): A=417 ± 55; B=367 ± 68; C=363 ± 84; D=329 ± 70; and E=314 ± 62. HF etching significantly reduced the mean flexural strength as the etching time increased (p=0.003). In conclusion, the findings of this study showed that the increase of HF etching time affected the surface roughness and the flexural strength of a lithium disilicate-based glass ceramic, confirming the study hypothesis.

  10. [Research on the surface electromyography signal decomposition based on multi-channel signal fusion analysis].

    PubMed

    Li, Qiang; Yang, Jihai

    2012-10-01

    The decomposition method of surface electromyography (sEMG) signals was explored by using the multi-channel information extraction and fusion analysis to acquire the motor unit action potential (MUAP) patterns. The action potential waveforms were detected with the combined method of continuous wavelet transform and hypothesis testing, and the effective detection analysis was judged with the multi-channel firing processes of motor units. The cluster number of MUAPs was confirmed by the hierarchical clustering technique, and then the decomposition was implemented by the fuzzy k-means clustering algorithms. The unclassified waveforms were processed by the template matching and peel-off methods. The experimental results showed that several kinds of MUAPs were precisely extracted from the multi-channel sEMG signals. The space potential distribution information of motor units could be satisfyingly represented by the proposed decomposition method. PMID:23198440

  11. Tensile bond strength of silicone-based soft denture liner to two chemically different denture base resins after various surface treatments.

    PubMed

    Akin, Hakan; Tugut, Faik; Guney, Umit; Kirmali, Omer; Akar, Turker

    2013-01-01

    This study evaluated the effect of various surface treatments on the tensile bond strength of a silicone-based soft denture liner to two chemically different denture base resins, heat-cured polymethyl methacrylate (PMMA), and light-activated urethane dimethacrylate or Eclipse denture base resin. PMMA test specimens were fabricated and relined with a silicone-based soft denture liner (group AC). Eclipse test specimens were prepared according to the manufacturer's recommendation. Before they were relined with a silicone-based soft denture liner, each received one of three surface treatments: untreated (control, group EC), Eclipse bonding agent applied (group EB), and laser-irradiated (group EL). Tensile bond strength tests (crosshead speed = 5 mm/min) were performed for all specimens, and the results were analyzed using the analysis of variance followed by Tukey's test (p = 0.05). Eclipse denture base and PMMA resins presented similar bond strengths to the silicone-based soft denture liner. The highest mean force was observed in group EL specimens, and the tensile bond strengths in group EL were significantly different (p < 0.05) from those in the other groups.

  12. Microstructural percolation assisted breakthrough of trade-off between strength and ductility in CuZr-based metallic glass composites.

    PubMed

    Liu, Z Q; Liu, G; Qu, R T; Zhang, Z F; Wu, S J; Zhang, T

    2014-01-01

    As two important mechanical properties, strength and ductility generally tend to be muturally exclusive in conventional engineering materials. The breakthrough of such a trade-off has been potentiated by the recently developed CuZr-based bulk metallic glass (BMG) composites ductilized by a shape memory CuZr(B2) phase. Here the microstructural dependences of tensile properties for the CuZr-based BMG composites were elucidated qualitatively and modeled quantitatively, and the underlying mechanisms were unraveled. Through the microstructural percolation induced by matching the length scales of particle size and interparticle spacing, a notable breakthrough was achieved in the composites that the general conflicts between strength and ductility can be defeated. This study is expected to greatly aid in the microstructural design and tailoring for improved properties of BMG composites. It also has implications for the development of strong and ductile materials in the future.

  13. Microstructural percolation assisted breakthrough of trade-off between strength and ductility in CuZr-based metallic glass composites

    PubMed Central

    Liu, Z. Q.; Liu, G.; Qu, R. T.; Zhang, Z. F.; Wu, S. J.; Zhang, T.

    2014-01-01

    As two important mechanical properties, strength and ductility generally tend to be muturally exclusive in conventional engineering materials. The breakthrough of such a trade-off has been potentiated by the recently developed CuZr-based bulk metallic glass (BMG) composites ductilized by a shape memory CuZr(B2) phase. Here the microstructural dependences of tensile properties for the CuZr-based BMG composites were elucidated qualitatively and modeled quantitatively, and the underlying mechanisms were unraveled. Through the microstructural percolation induced by matching the length scales of particle size and interparticle spacing, a notable breakthrough was achieved in the composites that the general conflicts between strength and ductility can be defeated. This study is expected to greatly aid in the microstructural design and tailoring for improved properties of BMG composites. It also has implications for the development of strong and ductile materials in the future. PMID:24566737

  14. The resistance to embrittlement by a hydrogen environment of selected high strength iron-manganese base alloys

    NASA Technical Reports Server (NTRS)

    Benson, R. B., Jr.; Kim, D. K.; Atteridge, D.; Gerberich, W. W.

    1974-01-01

    Fe-16Mn and Fe-25Mn base alloys, which had been cold worked to yield strength levels of 201 and 178 KSI, were resistant to degradation of mechanical properties in a one atmosphere hydrogen environment at ambient temperature under the loading conditions employed in this investigation. Transmission electron microscopy established that bands of epsilon phase martensite and fcc mechanical twins were formed throughout the fcc matrix when these alloys were cold worked. In the cold worked alloys a high density of crystal defects were observed associated with both types of strain induced structures, which should contribute significantly to the strengthening of these alloys. High strength iron base alloys can be produced which appear to have some resistance to degradation of mechanical properties in a hydrogen environment under certain conditions.

  15. Parasites and carotenoid-based signal intensity: how general should the relationship be?

    PubMed

    Shykoff, J A; Widmer, A

    1996-03-01

    Evidence that selection by parasites maintains heritable variation in sexually selected signals (Hamilton-Zuk model) has proved equivocal. Bright individuals do not always have fewer parasites in intraspecific comparisons. Because the lymphocyte-based defence system and the production of some colors used in sexual signaling require carotenoids, we consider a trade-off between defence against parasites and sexual signals. The nature and the sign of the covariance between defence and signal brightness can vary. Depending on carotenoid availability and allocation, and the type of sexual signal, various relationships between parasite load and signal intensity are expected.

  16. The effect of abrasive blasting on the strength of a joint between dental porcelain and metal base.

    PubMed

    Pietnicki, Krzysztof; Wołowiec, Emilia; Klimek, Leszek

    2014-01-01

    This paper presents the effect of selected parameters of abrasive blasting on the strength of a joint between dental porcelain and metal base. Experiments were conducted for different grain sizes of abrasive material and different blasting angles, with a constant blasting pressure. InLine dental porcelain was fused on samples of cobalt-chromium alloy following abrasive blasting; they were subsequently subjected to shearing forces on a testing machine. The fractures were observed under an electron scanning microscope in order to determine the character and course of fracturing. Strength tests showed that the grain size of abrasive material was a parameter with the greatest effect on the strength. The best effects were achieved for samples subjected to abrasive blasting with material with grain size of 110 μm. No statistically significant differences were found for the strength of samples worked at different angles. The results of the fractographic examinations have shown that in all the samples, fracturing occurred mainly along the porcelain-metal boundary, with few cases of fracturing through porcelain.

  17. Push-out bond strength of MTA HP, a new high-plasticity calcium silicate-based cement.

    PubMed

    Silva, Emmanuel Jnl; Carvalho, Nancy Kudsi; Zanon, Mayara; Senna, Plínio Mendes; DE-Deus, Gustavo; Zuolo, Mário Luis; Zaia, Alexandre Augusto

    2016-06-14

    This study was designed to investigate the resistance to dislodgment provided by MTA HP, a new high-plasticity calcium silicate-based cement. Biodentine and White MTA Angelus were used as reference materials for comparison. Three discs 1 ± 0.1 mm thick were obtained from the middle third of the roots of 5 maxillary canines. Three 0.8-mm-wide holes were drilled on the axial surface of each root disc. Standardized irrigation was performed. Then the holes were dried with paper points and filled with one of the three tested cements. The filled dental slices were immersed in a phosphate-buffered saline (PBS) solution (pH 7.2) for 7 days before the push-out assessment. The Kruskal-Wallis test was applied to assess the effect of each endodontic cement on the push-out bond strength. Mann-Whitney with Bonferroni correction was used to isolate the differences. The alpha-type error was set at 0.05. All specimens had measurable push-out values and no premature failure occurred. There were significant differences among the materials (p <0.05). The Biodentine specimens had the highest push-out bond strength values (p < 0.05). MTA HP had significantly higher bond strength than White MTA (p < 0.05). MTA HP showed better push-out bond strength than its predecessor, White MTA; however, Biodentine had higher dislodgment resistance than both MTA formulations.

  18. Static compressive strength prediction of open-hole structure based on non-linear shear behavior and micro-mechanics

    NASA Astrophysics Data System (ADS)

    Li, Wangnan; Cai, Hongneng; Li, Chao

    2014-11-01

    This paper deals with the characterization of the strength of the constituents of carbon fiber reinforced plastic laminate (CFRP), and a prediction of the static compressive strength of open-hole structure of polymer composites. The approach combined with non-linear analysis in macro-level and a linear elastic micromechanical failure analysis in microlevel (non-linear MMF) is proposed to improve the prediction accuracy. A face-centered cubic micromechanics model is constructed to analyze the stresses in fiber and matrix in microlevel. Non-interactive failure criteria are proposed to characterize the strength of fiber and matrix. The non-linear shear behavior of the laminate is studied experimentally, and a novel approach of cubic spline interpolation is used to capture significant non-linear shear behavior of laminate. The user-defined material subroutine UMAT for the non-linear share behavior is developed and combined in the mechanics analysis in the macro-level using the Abaqus Python codes. The failure mechanism and static strength of open-hole compressive (OHC) structure of polymer composites is studied based on non-linear MMF. The UTS50/E51 CFRP is used to demonstrate the application of theory of non-linear MMF.

  19. Physically Based Model of the Yield Strength for an Al-Mg-Si-Cu-Zn Alloy

    NASA Astrophysics Data System (ADS)

    Hosseini-Benhangi, Pooya; Mazinani, Mohammad; Haddad-Sabzevar, Mohsen

    2015-11-01

    The aim of this work is to implement recently developed modeling approaches to predict the mechanical behavior of a precipitation-hardened Al-Mg-Si-Cu-Zn alloy. Assuming that precipitates act as weak or strong obstacles to dislocation motion, a yield strength model, originally introduced for AA6111 alloy, is used to derive the precipitate strengthening formulations. The application of the model provides accurate predictions for the evolution of yield strength of the alloy during artificial aging. The transition point, at which shearable precipitates become non-shearable ones, has been identified directly from the result of tensile tests of AA6011(m) samples at different stages of artificial aging using work-hardening rate model. The linear/non-linear behavior of work-hardening rate of AA6011(m) samples at different stages of artificial aging is also studied. It is explained that high dynamic recovery rate in presence of non-shearable precipitates causes the non-linear work-hardening behavior of massively overaged sample. The modeling results for underaged samples show better agreement with measured values of yield strength when the weak obstacle model has been implemented, while strong obstacle model shows relatively good agreement between the experimental and calculated results for the peak-aged and overaged samples.

  20. A New Bioactive Polylactide-based Composite with High Mechanical Strength

    PubMed Central

    Dong, Quanxiao; Chow, Laurence C.; Wang, Tongxin; Frukhtbeyn, Stanislav A.; Wang, Feng; Yang, Mingshu; Mitchell, James W.

    2014-01-01

    A new bioresorbable polylactide/calcium phosphate composite with improved mechanical strengths and a more basic filler, tetracalcium phosphate (TTCP), was prepared by melt compounding. N-(2-aminoethyl)-3-aminoproplytrimethoxysilane (AEAPS) and pyromellitic dianhydride (PMDA) were used to improve the interfacial adhesion between TTCP and polylactide (PLA). While AEAPS improved the dispersion of TTCP in the matrix, PMDA might react with the terminal hydroxyl group of PLA and the amino group on the surface of AEAPS modified TTCP, which could further enhance the interfacial strength. The tensile strength was improved to 68.4 MPa for the PLA/TTCP-AEAPS composite from 51.5 MPa for the PLA/TTCP composite (20 wt% of TTCP). Dynamic mechanical analysis suggested that there was a 51 % improvement in storage modulus compared to that of PLA alone, when PMDA (0.2 wt% of PMDA) was incorporated into the PLA/TTCP-AEAPS composite (5 wt% of TTCP). Using this new bioresorbable PLA composite incorporated with a more basic filler for biomedical application, the inflammation and allergic effect resulted from the degraded acidic product are expected to be reduced. PMID:25419050

  1. Hydration and strength development of binder based on high-calcium oil shale fly ash

    SciTech Connect

    Freidin, C.

    1998-06-01

    The properties of high-calcium oil shale fly ash and low-calcium coal fly ash, which are produced in Israeli power stations, were investigated. High-calcium oil shale fly ash was found to contain a great amount of CaO{sub free} and SO{sub 3} in the form of lime and anhydrite. Mixtures of high-calcium oil shale fly ash and low-calcium coal fly ash, termed fly ash binder, were shown to cure and have improved strength. The influence of the composition and curing conditions on the compressive strength of fly ash binders was examined. The microstructure and the composition of fly ash binder after curing and long-term exposure in moist air, water and open air conditions were studied. It was determined that ettringite is the main variable in the strength and durability of cured systems. The positive effect of calcium silicate hydrates, CSH, which are formed by interaction of high-calcium oil shale fly ash and low-calcium coal fly ash components, on the carbonation and dehydration resistance of fly ash binder in open air is pronounced. It was concluded that high-calcium oil shale fly ash with high CaO{sub free} and SO{sub 3} content can be used as a binder for building products.

  2. Baseline Signal Reconstruction for Temperature Compensation in Lamb Wave-Based Damage Detection.

    PubMed

    Liu, Guoqiang; Xiao, Yingchun; Zhang, Hua; Ren, Gexue

    2016-01-01

    Temperature variations have significant effects on propagation of Lamb wave and therefore can severely limit the damage detection for Lamb wave. In order to mitigate the temperature effect, a temperature compensation method based on baseline signal reconstruction is developed for Lamb wave-based damage detection. The method is a reconstruction of a baseline signal at the temperature of current signal. In other words, it compensates the baseline signal to the temperature of current signal. The Hilbert transform is used to compensate the phase of baseline signal. The Orthogonal matching pursuit (OMP) is used to compensate the amplitude of baseline signal. Experiments were conducted on two composite panels to validate the effectiveness of the proposed method. Results show that the proposed method could effectively work for temperature intervals of at least 18 °C with the baseline signal temperature as the center, and can be applied to the actual damage detection. PMID:27529245

  3. Baseline Signal Reconstruction for Temperature Compensation in Lamb Wave-Based Damage Detection

    PubMed Central

    Liu, Guoqiang; Xiao, Yingchun; Zhang, Hua; Ren, Gexue

    2016-01-01

    Temperature variations have significant effects on propagation of Lamb wave and therefore can severely limit the damage detection for Lamb wave. In order to mitigate the temperature effect, a temperature compensation method based on baseline signal reconstruction is developed for Lamb wave-based damage detection. The method is a reconstruction of a baseline signal at the temperature of current signal. In other words, it compensates the baseline signal to the temperature of current signal. The Hilbert transform is used to compensate the phase of baseline signal. The Orthogonal matching pursuit (OMP) is used to compensate the amplitude of baseline signal. Experiments were conducted on two composite panels to validate the effectiveness of the proposed method. Results show that the proposed method could effectively work for temperature intervals of at least 18 °C with the baseline signal temperature as the center, and can be applied to the actual damage detection. PMID:27529245

  4. Evaluating the shear bond strength of enamel and dentin with or without etching: A comparative study between dimethacrylate-based and silorane-based adhesives

    PubMed Central

    Hajizadeh, Hila; Nasseh, Atefeh; Rahmanpour, Naim

    2015-01-01

    Background Silorane-based composites and their specific self-etch adhesive were introduced to conquest the polymerization shrinkage of methacrylate-based composites. It has been shown that additional etching of enamel and dentin can improve the bond strength of self-etch methacrylate-based adhesives but this claim is not apparent about silorane-based adhesives. Our objective was to compare the shear bond strength (SBS) of enamel and dentin between silorane-based adhesive resin and a methacrylate-based resin with or without additional etching. Material and Methods 40 sound human premolars were prepared and divided into two groups: 1- Filtek P60 composite and Clearfil SE Bond adhesive; 2- Filtek P90 composite and Silorane adhesive. Each group divided into two subgroups: with or without additional etching. For additional etching, 37% acid phosphoric was applied before bonding procedure. A cylinder of the composite was bonded to the surface. After 24 hours storage and 500 thermo cycling between 5-55°C, shear bond strength was assessed with the cross head speed of 0.5 mm/min. Then, bonded surfaces were observed under stereomicroscope to determine the failure mode. Data were analyzed with two-way ANOVA and Fischer exact test. Results Shear bond strength of Filtek P60 composite was significantly higher than Filtek P90 composite both in enamel and dentin surfaces (P<0.05). However, additional etching had no significant effect on shear bond strength in enamel or dentin for each of the composites (P>0.05). There was no interaction between composite type and additional etching (P>0.05). Failure pattern was mainly adhesive and no significant correlation was found between failure and composite type or additional etching (P>0.05). Conclusions Shear bond strength of methacrylate-based composite was significantly higher than silorane-based composite both in enamel and dentin surfaces and additional etching had no significant effect on shear bond strength in enamel or dentin for

  5. The Influence of No-Primer Adhesives and Anchor Pylons Bracket Bases on Shear Bond Strength of Orthodontic Brackets

    PubMed Central

    Sfondrini, Maria Francesca; Fraticelli, Danilo; Daina, Paola; Tamagnone, Alessandra; Gandini, Paola

    2013-01-01

    Objective. The aim of this study was to compare the shear bond strength (SBS) and adhesive remnant index (ARI) scores of no-primer adhesives tested with two different bracket bases. Materials and Methods. 120 bovine permanent mandibular incisors were divided into 6 groups of 20 specimens. Two brackets (ODP) with different bracket bases (anchor pylons and 80-gauge mesh) were bonded to the teeth using a conventional adhesive (Transbond XT) and two different no-primer adhesive (Ortho Cem; Heliosit) systems. Groups were tested using an instron universal testing machine. SBS values were recorded. ARI scores were measured. SEM microphotographs were taken to evaluate the pattern of bracket bases. Statistical analysis was performed. ANOVA and Tukey tests were carried out for SBS values, whereas a chi-squared test was applied for ARI scores. Results. Highest bond strength values were reported with Transbond XT (with both pad designs), Ortho Cem bonded on anchor pylons and Heliosit on 80-gauge mesh. A higher frequency of ARI score of “3” was reported for Transbond XT groups. Other groups showed a higher frequency of ARI score “2” and “1.” Conclusion. Transbond XT showed the highest shear bond strength values with both pad designs. PMID:23984339

  6. Evaluation of flexural strength and color stability of different denture base materials including flexible material after using different denture cleansers

    PubMed Central

    Shah, Vrinda R.; Shah, Darshana Nilesh; Chauhan, Chirag J.; Doshi, Paras J.; Kumar, Ashish

    2015-01-01

    Aims: Present study aimed at evaluating the colour stability and flexural strength of flexible denture base materials (Valplast) and Polymethyl methacrylate (PMMA) denture base material (Meliodent) processed by two different methods (Injection moulding and compression moulding) after immersing them in three different denture cleansers with acidic, basic and neutral PH. Methods and Materials: Total 120 specimens (65 × 10 × 3 mm3), 40 specimens of each material (Valplast, Meliodent compression moulding and injection moulding) were immersed in denture cleansers having different PH; Valclean (Acidic), Clinsodent (Basic) and Polident (Neutral) as well as Distilled Water. Color changes were measured with a spectrophotometer after 1 month, 3 months and 6 months of immersion cycle. A flexural 3-point bending test was carried out by using an Instron universal testing machine after 6 months of soaking. Data were analyzed using SPSS software Results: Maximum effect on colour stability was noted with Clinsodent followed by Valclean. Least color changes were observed after immersion in Polident. Colour difference was increased significantly as the immersion time increased. For both Meliodent and Nylon resins, statistically significant change in flexural strength occurred with immersion in all denture cleansers. Clinsodent has greater effect as compared to Valclean and Polident. Conclusions: Polident and Valclean can be safely used as denture cleanser for both nylon and acrylic resin denture base materials as far as colour stability and flexural strength both are concerned. PMID:26929541

  7. Effect of artificial saliva and pH on shear bond strength of resin cements to zirconia-based ceramic.

    PubMed

    Geramipanah, F; Majidpour, M; Sadighpour, L; Fard, M J Kharazi

    2013-03-01

    The aim of the present study was to evaluate the effect of media with different pH on shear and strength of resin cements to zirconia-based ceramics. Sixty rectangularly shaped specimens made of a zirconia based ceramic (Cercon, Dentsply) were prepared, air-blasted with 110 microm aluminum oxide particles (Al203) and randomly assigned into three groups (n = 30). A universal resin composite (Filtek Z250, 3M/ESPE) was bonded to each specimen using one of the following three cements: Calibra (Dentsply), Panavia F2 (kurary) and Unicem (3M/ESPE). Specimens were thermal cycled and stored in one of the following three media for two weeks: water at pH = 7, saliva at pH = 7 and saliva at pH = 3.5. The mean shear bond strength of each group was analyzed using the Kruskal-Wallis test (alpha = 0.05). The modes of failure were recorded using a streomicroscope. All specimens in the Calibra groups showed premature debonding. No significant difference was found between the two other cements or different media. The failure modes in the two latter cements were predominantly adhesive. Despite the adverse effect of acidic media on the properties of restorative materials, the media did not significantly influence the bond strength of MDP-containing resin cement and a self-adhesive cement to a zirconia- based ceramic.

  8. A method based on stochastic resonance for the detection of weak analytical signal.

    PubMed

    Wu, Xiaojing; Guo, Weiming; Cai, Wensheng; Shao, Xueguang; Pan, Zhongxiao

    2003-12-23

    An effective method for detection of weak analytical signals with strong noise background is proposed based on the theory of stochastic resonance (SR). Compared with the conventional SR-based algorithms, the proposed algorithm is simplified by changing only one parameter to realize the weak signal detection. Simulation studies revealed that the method performs well in detection of analytical signals in very high level of noise background and is suitable for detecting signals with the different noise level by changing the parameter. Applications of the method to experimental weak signals of X-ray diffraction and Raman spectrum are also investigated. It is found that reliable results can be obtained.

  9. EMD-Based Symbolic Dynamic Analysis for the Recognition of Human and Nonhuman Pyroelectric Infrared Signals

    PubMed Central

    Zhao, Jiaduo; Gong, Weiguo; Tang, Yuzhen; Li, Weihong

    2016-01-01

    In this paper, we propose an effective human and nonhuman pyroelectric infrared (PIR) signal recognition method to reduce PIR detector false alarms. First, using the mathematical model of the PIR detector, we analyze the physical characteristics of the human and nonhuman PIR signals; second, based on the analysis results, we propose an empirical mode decomposition (EMD)-based symbolic dynamic analysis method for the recognition of human and nonhuman PIR signals. In the proposed method, first, we extract the detailed features of a PIR signal into five symbol sequences using an EMD-based symbolization method, then, we generate five feature descriptors for each PIR signal through constructing five probabilistic finite state automata with the symbol sequences. Finally, we use a weighted voting classification strategy to classify the PIR signals with their feature descriptors. Comparative experiments show that the proposed method can effectively classify the human and nonhuman PIR signals and reduce PIR detector’s false alarms. PMID:26805837

  10. EMD-Based Symbolic Dynamic Analysis for the Recognition of Human and Nonhuman Pyroelectric Infrared Signals.

    PubMed

    Zhao, Jiaduo; Gong, Weiguo; Tang, Yuzhen; Li, Weihong

    2016-01-01

    In this paper, we propose an effective human and nonhuman pyroelectric infrared (PIR) signal recognition method to reduce PIR detector false alarms. First, using the mathematical model of the PIR detector, we analyze the physical characteristics of the human and nonhuman PIR signals; second, based on the analysis results, we propose an empirical mode decomposition (EMD)-based symbolic dynamic analysis method for the recognition of human and nonhuman PIR signals. In the proposed method, first, we extract the detailed features of a PIR signal into five symbol sequences using an EMD-based symbolization method, then, we generate five feature descriptors for each PIR signal through constructing five probabilistic finite state automata with the symbol sequences. Finally, we use a weighted voting classification strategy to classify the PIR signals with their feature descriptors. Comparative experiments show that the proposed method can effectively classify the human and nonhuman PIR signals and reduce PIR detector's false alarms. PMID:26805837

  11. Thiol-based redox signalling: rust never sleeps.

    PubMed

    Wouters, Merridee A; Iismaa, Siiri; Fan, Samuel W; Haworth, Naomi L

    2011-08-01

    Cysteine residues in proteins are covalently modified under conditions of oxidative and nitrosative stress by oxidation, nitrosation, glutathionylation and disulfide formation. Modifications induce conformational changes in substrate proteins, effecting signal cascades that evoke a biological response. A growing number of structures with modified cysteines are allowing a piecemeal understanding of the mechanistic aspects of these signalling pathways to emerge. Conformational changes upon conjugation of nitric oxide and glutathione are generally small and often accompanied by a local increase in protein disorder. Burial of nitric oxide is also apparent, which may increase the timeframe of signalling. Conformational changes upon disulfide formation/reduction range from the small to the spectacular. They include order/disorder transitions; oxidation of disulfides following expulsion of metals such as Zn; major reorganisation or "morphing" of portions of the polypeptide backbone; and changes in quaternary structure including domain swapping. PMID:21513814

  12. Thiol-based redox signalling: rust never sleeps.

    PubMed

    Wouters, Merridee A; Iismaa, Siiri; Fan, Samuel W; Haworth, Naomi L

    2011-08-01

    Cysteine residues in proteins are covalently modified under conditions of oxidative and nitrosative stress by oxidation, nitrosation, glutathionylation and disulfide formation. Modifications induce conformational changes in substrate proteins, effecting signal cascades that evoke a biological response. A growing number of structures with modified cysteines are allowing a piecemeal understanding of the mechanistic aspects of these signalling pathways to emerge. Conformational changes upon conjugation of nitric oxide and glutathione are generally small and often accompanied by a local increase in protein disorder. Burial of nitric oxide is also apparent, which may increase the timeframe of signalling. Conformational changes upon disulfide formation/reduction range from the small to the spectacular. They include order/disorder transitions; oxidation of disulfides following expulsion of metals such as Zn; major reorganisation or "morphing" of portions of the polypeptide backbone; and changes in quaternary structure including domain swapping.

  13. [Study on neurofeedback system based on electroencephalogram signals].

    PubMed

    Pu, Xianjie; Liu, Tiejun; Wu, Qiang; Zhang, Rui; Xu, Peng; Li, Ke; Xia, Yang; Yao, Dezhong

    2014-08-01

    Neurofeedback, as an alternative treatment method of behavioral medicine, is a technique which translates the electroencephalogram (EEG) signals to styles as sounds or animation to help people understand their own physical status and learn to enhance or suppress certain EEG signals to regulate their own brain functions after several repeated trainings. This paper develops a neurofeedback system on the foundation of brain-computer interface technique. The EEG features are extracted through real-time signal process and then translated to feedback information. Two feedback screens are designed for relaxation training and attention training individually. The veracity and feasibility of the neurofeedback system are validated through system simulation and preliminary experiment. Key words: neurofeedback; electroencephalogram; feature extraction; brain-computer interface PMID:25508440

  14. Orbital Analysis of Molecular Optical Activity Based on Configuration Rotatory Strength.

    PubMed

    Caricato, Marco

    2015-04-14

    We present a method to analyze the origin of molecular optical activity in terms of orbital contributions and rotatory strength in configuration space. The method uses quantities already available at completion of standard linear-response calculations of specific rotation and requires minimal manipulation. Preliminary application to (1S,4S)-norborne-none and (P)-2,3-pentadiene shows that only a few orbitals (6 and 4, respectively) contribute significantly to the specific rotation and can be used directly for a qualitative interpretation of this fundamental property.

  15. Global strength assessment in oblique waves of a large gas carrier ship, based on a non-linear iterative method

    NASA Astrophysics Data System (ADS)

    Domnisoru, L.; Modiga, A.; Gasparotti, C.

    2016-08-01

    At the ship's design, the first step of the hull structural assessment is based on the longitudinal strength analysis, with head wave equivalent loads by the ships' classification societies’ rules. This paper presents an enhancement of the longitudinal strength analysis, considering the general case of the oblique quasi-static equivalent waves, based on the own non-linear iterative procedure and in-house program. The numerical approach is developed for the mono-hull ships, without restrictions on 3D-hull offset lines non-linearities, and involves three interlinked iterative cycles on floating, pitch and roll trim equilibrium conditions. Besides the ship-wave equilibrium parameters, the ship's girder wave induced loads are obtained. As numerical study case we have considered a large LPG liquefied petroleum gas carrier. The numerical results of the large LPG are compared with the statistical design values from several ships' classification societies’ rules. This study makes possible to obtain the oblique wave conditions that are inducing the maximum loads into the large LPG ship's girder. The numerical results of this study are pointing out that the non-linear iterative approach is necessary for the computation of the extreme loads induced by the oblique waves, ensuring better accuracy of the large LPG ship's longitudinal strength assessment.

  16. Analysis of strength and failure pattern of human proximal femur using quantitative computed tomography (QCT)-based finite element method.

    PubMed

    Mirzaei, Majid; Keshavarzian, Maziyar; Naeini, Vahid

    2014-07-01

    This paper presents a novel method for fast and reliable prediction of the failure strength of human proximal femur, using the quantitative computed tomography (QCT)-based linear finite element analysis (FEA). Ten fresh frozen human femora (age: 34±16) were QCT-scanned and the pertinent 3D voxel-based finite element models were constructed. A specially-designed holding frame was used to define and maintain a unique geometrical reference system for both FEA and in-vitro mechanical testing. The analyses and tests were carried out at 8 different loading orientations. A new scheme was developed for assortment of the element risk factor (defined as the ratio of the strain energy density to the yield strain energy for each element) and implemented for the prediction of the failure strength. The predicted and observed failure patterns were in correspondence, and the FEA predictions of the failure loads were in very good agreement with the experimental results (R2=0.86, slope=0.96, p<0.01). The average computational time was 5 min (on a regular desktop personal computer) for an average element number of 197,000. Noting that the run-time for a similar nonlinear model is about 8h, it was concluded that the proposed linear scheme is overwhelmingly efficient in terms of computational costs. Thus, it can efficiently be used to predict the femoral failure strength with the same accuracy of similar nonlinear models. PMID:24735974

  17. Time/Temperature Dependent Tensile Strength of SiC and Al2O3-Based Fibers

    NASA Technical Reports Server (NTRS)

    Yun, Hee Mann; DiCarlo, James A.

    1997-01-01

    In order to understand and model the thermomechanical behavior of fiber-reinforced composites, stress-rupture, fast-fracture, and warm-up rupture studies were conducted on various advanced SiC and Al2O3-based fibers in the,temperature range from 20 to 1400 C in air as well as in inert environments. The measured stress-rupture, fast fracture, and warm-up rupture strengths were correlated into a single master time/temperature-dependent strength plot for each fiber type using thermal activation and slow crack growth theories. It is shown that these plots are useful for comparing and selecting fibers for CMC and MMC reinforcement and that, in comparison to stress rupture tests, the fast-fracture and warm-up tests can be used for rapid generation of these plots.

  18. Entrepreneurship education: A strength-based approach to substance use and suicide prevention for American Indian adolescents.

    PubMed

    Tingey, Lauren; Larzelere-Hinton, Francene; Goklish, Novalene; Ingalls, Allison; Craft, Todd; Sprengeler, Feather; McGuire, Courtney; Barlow, Allison

    2016-01-01

    American Indian (AI) adolescents suffer the largest disparities in substance use and suicide. Predominating prevention models focus primarily on risk and utilize deficit-based approaches. The fields of substance use and suicide prevention research urge for positive youth development frameworks that are strength based and target change at individual and community levels. Entrepreneurship education is an innovative approach that reflects the gap in available programs. This paper describes the development and evaluation of a youth entrepreneurship education program in partnership with one AI community. We detail the curriculum, process evaluation results, and the randomized controlled trial evaluating its efficacy for increasing protective factors. Lessons learned may be applicable to other AI communities.

  19. Water proof and strength retention properties of thermoplastic starch based biocomposites modified with glutaraldehyde.

    PubMed

    Yeh, Jen-taut; Hou, Yuan-jing; Cheng, Li; Wang, Ya-Zhou; Yang, Liang; Wang, Chuen-kai

    2015-01-01

    Water proof and strength retention properties of thermoplastic starch (TPS) resins were successfully improved by reacting glutaraldehyde (GA) with starch molecules during their gelatinization processes. Tensile strength (σf) values of initial and aged TPS100BC0.02GAx and (TPS100BC0.02GAx)75PLA25 specimens improved significantly to a maximal value as GA contents approached an optimal value, while their moisture content and elongation at break values reduced to a minimal value, respectively, as GA contents approached the optimal value. The σf retention values of (TPS100BC0.02GA0.5)75PLA25 specimen aged for 56 days are more than 50 times higher than those of corresponding aged TPS and TPS100BC0.02 specimens, respectively. New melting endotherms and diffraction peaks of VH-type starch crystals were found on DSC thermograms and WAXD patterns of aged TPS or TPS100BC0.02 specimens, respectively, while negligible retrogradation effect was found for most aged TPS100BC0.02GAx and/or (TPS100BC0.02GAx)75PLA25 specimens. PMID:25965466

  20. Signal digitizing system and method based on amplitude-to-time optical mapping

    DOEpatents

    Chou, Jason; Bennett, Corey V; Hernandez, Vince

    2015-01-13

    A signal digitizing system and method based on analog-to-time optical mapping, optically maps amplitude information of an analog signal of interest first into wavelength information using an amplitude tunable filter (ATF) to impress spectral changes induced by the amplitude of the analog signal onto a carrier signal, i.e. a train of optical pulses, and next from wavelength information to temporal information using a dispersive element so that temporal information representing the amplitude information is encoded in the time domain in the carrier signal. Optical-to-electrical conversion of the optical pulses into voltage waveforms and subsequently digitizing the voltage waveforms into a digital image enables the temporal information to be resolved and quantized in the time domain. The digital image may them be digital signal processed to digitally reconstruct the analog signal based on the temporal information with high fidelity.

  1. Reconfigurable Optical Signal Processing Based on a Distributed Feedback Semiconductor Optical Amplifier

    PubMed Central

    Li, Ming; Deng, Ye; Tang, Jian; Sun, Shuqian; Yao, Jianping; Azaña, José; Zhu, Ninghua

    2016-01-01

    All-optical signal processing has been considered a solution to overcome the bandwidth and speed limitations imposed by conventional electronic-based systems. Over the last few years, an impressive range of all-optical signal processors have been proposed, but few of them come with reconfigurability, a feature highly needed for practical signal processing applications. Here we propose and experimentally demonstrate an analog optical signal processor based on a phase-shifted distributed feedback semiconductor optical amplifier (DFB-SOA) and an optical filter. The proposed analog optical signal processor can be reconfigured to perform signal processing functions including ordinary differential equation solving and temporal intensity differentiation. The reconfigurability is achieved by controlling the injection currents. Our demonstration provitdes a simple and effective solution for all-optical signal processing and computing. PMID:26813252

  2. Reconfigurable Optical Signal Processing Based on a Distributed Feedback Semiconductor Optical Amplifier.

    PubMed

    Li, Ming; Deng, Ye; Tang, Jian; Sun, Shuqian; Yao, Jianping; Azaña, José; Zhu, Ninghua

    2016-01-27

    All-optical signal processing has been considered a solution to overcome the bandwidth and speed limitations imposed by conventional electronic-based systems. Over the last few years, an impressive range of all-optical signal processors have been proposed, but few of them come with reconfigurability, a feature highly needed for practical signal processing applications. Here we propose and experimentally demonstrate an analog optical signal processor based on a phase-shifted distributed feedback semiconductor optical amplifier (DFB-SOA) and an optical filter. The proposed analog optical signal processor can be reconfigured to perform signal processing functions including ordinary differential equation solving and temporal intensity differentiation. The reconfigurability is achieved by controlling the injection currents. Our demonstration provitdes a simple and effective solution for all-optical signal processing and computing.

  3. A Cochlear Implant Signal Processing Lab: Exploration of a Problem-Based Learning Exercise

    ERIC Educational Resources Information Center

    Bhatti, P. T.; McClellan, J. H.

    2011-01-01

    This paper presents an introductory signal processing laboratory and examines this laboratory exercise in the context of problem-based learning (PBL). Centered in a real-world application, a cochlear implant, the exercise challenged students to demonstrate a working software-based signal processor. Partnering in groups of two or three, second-year…

  4. Digital audio signal filtration based on the dual-tree wavelet transform

    NASA Astrophysics Data System (ADS)

    Yaseen, A. S.; Pavlov, A. N.

    2015-07-01

    A new method of digital audio signal filtration based on the dual-tree wavelet transform is described. An adaptive approach is proposed that allows the automatic adjustment of parameters of the wavelet filter to be optimized. A significant improvement of the quality of signal filtration is demonstrated in comparison to the traditionally used filters based on the discrete wavelet transform.

  5. Sub-Audible Speech Recognition Based upon Electromyographic Signals

    NASA Technical Reports Server (NTRS)

    Jorgensen, Charles C. (Inventor); Lee, Diana D. (Inventor); Agabon, Shane T. (Inventor)

    2012-01-01

    Method and system for processing and identifying a sub-audible signal formed by a source of sub-audible sounds. Sequences of samples of sub-audible sound patterns ("SASPs") for known words/phrases in a selected database are received for overlapping time intervals, and Signal Processing Transforms ("SPTs") are formed for each sample, as part of a matrix of entry values. The matrix is decomposed into contiguous, non-overlapping two-dimensional cells of entries, and neural net analysis is applied to estimate reference sets of weight coefficients that provide sums with optimal matches to reference sets of values. The reference sets of weight coefficients are used to determine a correspondence between a new (unknown) word/phrase and a word/phrase in the database.

  6. Energy Measurement of Bubble Bursting Based on Vibration Signals

    NASA Astrophysics Data System (ADS)

    Liu, Xiao-Bo; Zhang, Jian-Run; Li, Pu; Le, Van-Quynh

    2012-06-01

    An experimental study of the energy of bubble bursting at the surface of a high-viscosity liquid on a cantilever beam is reported. The sudden bursting event of a bubble at the liquid surface can cause a vibration of the cantilever beam besides the acoustic wave and jet wave. The peaks of the vibration signal from the beam slightly lag the peaks of the acoustic signal, and the energy transferred to the vibration is larger than that transferred to the acoustic wave. The amplitude of the jet wave depends on the thickness of the liquid film and the size of the bubble. The results of the investigation can be used to understand the dynamic characteristics of bubble bursting.

  7. Unified nano-mechanics based probabilistic theory of quasibrittle and brittle structures: I. Strength, static crack growth, lifetime and scaling

    NASA Astrophysics Data System (ADS)

    Le, Jia-Liang; Bažant, Zdeněk P.; Bazant, Martin Z.

    2011-07-01

    Engineering structures must be designed for an extremely low failure probability such as 10 -6, which is beyond the means of direct verification by histogram testing. This is not a problem for brittle or ductile materials because the type of probability distribution of structural strength is fixed and known, making it possible to predict the tail probabilities from the mean and variance. It is a problem, though, for quasibrittle materials for which the type of strength distribution transitions from Gaussian to Weibullian as the structure size increases. These are heterogeneous materials with brittle constituents, characterized by material inhomogeneities that are not negligible compared to the structure size. Examples include concrete, fiber composites, coarse-grained or toughened ceramics, rocks, sea ice, rigid foams and bone, as well as many materials used in nano- and microscale devices. This study presents a unified theory of strength and lifetime for such materials, based on activation energy controlled random jumps of the nano-crack front, and on the nano-macro multiscale transition of tail probabilities. Part I of this study deals with the case of monotonic and sustained (or creep) loading, and Part II with fatigue (or cyclic) loading. On the scale of the representative volume element of material, the probability distribution of strength has a Gaussian core onto which a remote Weibull tail is grafted at failure probability of the order of 10 -3. With increasing structure size, the Weibull tail penetrates into the Gaussian core. The probability distribution of static (creep) lifetime is related to the strength distribution by the power law for the static crack growth rate, for which a physical justification is given. The present theory yields a simple relation between the exponent of this law and the Weibull moduli for strength and lifetime. The benefit is that the lifetime distribution can be predicted from short-time tests of the mean size effect on

  8. High Fidelity Tape Transfer Printing Based On Chemically Induced Adhesive Strength Modulation

    PubMed Central

    Sim, Kyoseung; Chen, Song; Li, Yuhang; Kammoun, Mejdi; Peng, Yun; Xu, Minwei; Gao, Yang; Song, Jizhou; Zhang, Yingchun; Ardebili, Haleh; Yu, Cunjiang

    2015-01-01

    Transfer printing, a two-step process (i.e. picking up and printing) for heterogeneous integration, has been widely exploited for the fabrication of functional electronics system. To ensure a reliable process, strong adhesion for picking up and weak or no adhesion for printing are required. However, it is challenging to meet the requirements of switchable stamp adhesion. Here we introduce a simple, high fidelity process, namely tape transfer printing(TTP), enabled by chemically induced dramatic modulation in tape adhesive strength. We describe the working mechanism of the adhesion modulation that governs this process and demonstrate the method by high fidelity tape transfer printing several types of materials and devices, including Si pellets arrays, photodetector arrays, and electromyography (EMG) sensors, from their preparation substrates to various alien substrates. High fidelity tape transfer printing of components onto curvilinear surfaces is also illustrated. PMID:26553110

  9. High Fidelity Tape Transfer Printing Based On Chemically Induced Adhesive Strength Modulation

    NASA Astrophysics Data System (ADS)

    Sim, Kyoseung; Chen, Song; Li, Yuhang; Kammoun, Mejdi; Peng, Yun; Xu, Minwei; Gao, Yang; Song, Jizhou; Zhang, Yingchun; Ardebili, Haleh; Yu, Cunjiang

    2015-11-01

    Transfer printing, a two-step process (i.e. picking up and printing) for heterogeneous integration, has been widely exploited for the fabrication of functional electronics system. To ensure a reliable process, strong adhesion for picking up and weak or no adhesion for printing are required. However, it is challenging to meet the requirements of switchable stamp adhesion. Here we introduce a simple, high fidelity process, namely tape transfer printing(TTP), enabled by chemically induced dramatic modulation in tape adhesive strength. We describe the working mechanism of the adhesion modulation that governs this process and demonstrate the method by high fidelity tape transfer printing several types of materials and devices, including Si pellets arrays, photodetector arrays, and electromyography (EMG) sensors, from their preparation substrates to various alien substrates. High fidelity tape transfer printing of components onto curvilinear surfaces is also illustrated.

  10. A multi-site, randomized study of strengths-based case management with substance-abusing parolees.

    PubMed

    Prendergast, Michael; Frisman, Linda; Sacks, Joann Y; Staton-Tindall, Michele; Greenwell, Lisa; Lin, Hsiu-Ju; Cartier, Jerry

    2011-09-01

    OBJECTIVES: To test whether strengths-based case management provided during an inmate's transition from incarceration to the community increases participation in community substance abuse treatment, enhances access to needed social services, and improves drug use, crime, and HIV risk outcomes. METHODS: In a multi-site trial, inmates (men and women) in four states (n = 812) were randomly assigned (within site) to receive either Transitional Case Management (TCM group), based on strengths-based principles, or standard parole services (SR group). Data were collected at baseline and at 3 and 9 months following release from prison. Analyses compared the two groups with respect to services received and to drug use, crime, and HIV risk behavior outcomes. RESULTS: There were no significant differences between parolees in the TCM group and the SR group on outcomes related to participation in drug abuse treatment, receipt of social services, or drug use, crime, and HIV risk behaviors. For specific services (e.g., residential treatment, mental health), although significant differences were found for length of participation or for number of visits, the number of participants in these services was small and the direction of effect was not consistent. CONCLUSION: In contrast to positive findings in earlier studies of strengths-based case management with mental-health and drug-abuse clients, this study found that case management did not improve treatment participation or behavioral outcomes for parolees with drug problems. The discussion includes possible reasons for the findings and suggestions for modifications to the intervention that could be addressed in future research.

  11. Relative Handgrip Strength Is a Simple Indicator of Cardiometabolic Risk among Middle-Aged and Older People: A Nationwide Population-Based Study in Taiwan

    PubMed Central

    Lee, Wei-Ju; Peng, Li-Ning; Chiou, Shu-Ti; Chen, Liang-Kung

    2016-01-01

    Background Muscle strength may play an important role in cardiovascular health. The study was intended to evaluate the association between cardiometabolic risk, risk of coronary artery disease and handgrip strength by using the relative handgrip strength. Materials and Methods Data of 927 Taiwanese aged 53 years and older (510 men and 417 women) were retrieved from a nationwide representative population-based cohort cross-sectional study in 2006. All participants were interviewed face-to-face and received measures of anthropometry, dominant handgrip strength, relative handgrip strength (summation of both handgrip strength divided by body mass index) and serum biomarkers. Results Multivariate linear regression analysis showed the significant association between relative handgrip strength and favorable cardiometabolic risk factors including blood pressure, triglyceride, total cholesterol to high density cholesterol(HDL-C) ratio, glycohemoglobin (HbA1c), uric acid, Framingham risk score in men, and HDL-C, fasting glucose, HbA1c, log hsCRP in women. Dominant hand grip strength was only associated with log hsCRP in women. (p<0.05 for all), but was not significant associated with all cardiovascular biomarkers and FRS in both sex. Conclusions Joint with handgrip strength and body size, as relative handgrip strength, may be a better tool to capture conceptual concomitant health, which may be a simple, inexpensive, and easy-to-use tool when targeting cardiovascular health in public health level. PMID:27559733

  12. Mechanical Strength and Surface Roughness of Magnesium-Based Metallic Glasses

    NASA Astrophysics Data System (ADS)

    Fernandes, Daniel Jogaib; Elias, Carlos Nelson; de Souza Resende, Celso Renato; Bolfarini, Claudemiro

    2016-06-01

    This work evaluated the mechanical strength and surface roughness of MgZn30Ca5 ribbon manufactured via a melt spinning technique for applications in the biomedical field. Annealing was performed at 280°C. The inner side (in contact with the wheel) and the outer side (not in contact with the wheel) of the ribbons were mechanically evaluated using nanoindentation, and its surfaces were analyzed by an optical profilometer. Differential scanning calorimeter (DSC) and X-ray diffraction (XRD) analyses were also performed to identify the structure and devitrification of the magnesium metallic glass (MgMG). The nanohardness and elastic modulus increased after annealing (p < 0.0001). No differences were seen in the strength between the two sides of the ribbons (p > 0.05). Although both sides of the ribbons showed different surface profiles (p < 0.0001), no statistical difference was detected in roughness parameters on either ribbon side before (p = 0.3094) and after (p = 0.8742) annealing. DSC curves showed disturbances in enthalpy attributed to a relaxation in the MgMG structure and free volume annihilation. The DRX diffractogram showed sharp peaks after annealing, with MgZn and Ca2Mg5Zn13 phases being identified. Although the use of MgMG in biomedical applications is promising, the ribbons displayed limited ductility, toughness, and a relevant embrittlement after the annealing procedure. There were significant changes in the surface profile of both sides of the ribbons. Nevertheless, neither annealing nor the ribbon side had influenced surface roughness parameters.

  13. Joint effect of scandium and zirconium on the structure and the strength properties of Al-Mg2Si-Based alloys

    NASA Astrophysics Data System (ADS)

    Rokhlin, L. L.; Bochvar, N. R.; Tarytina, I. E.

    2015-09-01

    The joint effect of scandium and zirconium on the strength properties and the electrical resistivity of industrial Al-Mg2Si-based alloys has been studied. The additional alloying of Al-Mg2Si alloys with transition metals leads to substantial grain refinement of the aluminum solid-solution and, therefore, an increase in the strength properties of the industrial alloys.

  14. Evaluation of bond strength of silorane and methacrylate based restorative systems to dentin using different cavity models

    PubMed Central

    ISAAC, Stephano Zerlottini; BERGAMIN, Ana Claudia Pietrobom; TURSSI, Cecília Pedroso; do AMARAL, Flávia Lucisano Botelho; BASTING, Roberta Tarkany; FRANÇA, Fabiana Mantovani Gomes

    2013-01-01

    Objective The aim of this in vitro study was to evaluate the microtensile bond strength (µTBS) to dentin of two different restorative systems: silorane-based (P90), and methacrylate-based (P60), using two cavity models. Material and Methods Occlusal enamel of 40 human third molars was removed to expose flat dentin surface. Class I cavities with 4 mm mesial-distal width, 3 mm buccal-lingual width and 3 mm depth (C-factor=4.5) were prepared in 20 teeth, which were divided into two groups (n=10) restored with P60 and P90, bulk-filled after dentin treatment according to manufacturer's instructions. Flat buccal dentin surfaces were prepared in the 20 remaining teeth (C-factor=0.2) and restored with resin blocks measuring 4x3x3 mm using the two restorative systems (n=10). The teeth were sectioned into samples with area between 0.85 and 1.25 mm2 that were submitted to µTBS testing, using a universal testing machine (EMIC) at speed of 0.5 mm/min. Fractured specimens were analyzed under stereomicroscope and categorized according to fracture pattern. Data were analyzed using ANOVA and Tukey Kramer tests. Results For flat surfaces, P60 obtained higher bond strength values compared with P90. However, for Class I cavities, P60 showed significant reduction in bond strength (p<0.05). No statistical difference between restorative systems was shown for Class I cavity model (p>0.05), or between Class I Cavity and Flat Surface group, considering P90 restorative system (p>0.05). Regarding fracture pattern, there was no statistical difference among groups (p=0.0713) and 56.3% of the fractures were adhesive. Conclusion It was concluded that methacrylate-based composite µTBS was influenced by cavity models, and the use of silorane-based composite led to similar bond strength values compared to the methacrylate-based composite in cavities with high C-factor. PMID:24212992

  15. Predation-associated modulation of movement-based signals by a Bahamian lizard

    PubMed Central

    Steinberg, David S.; Losos, Jonathan B.; Schoener, Thomas W.; Spiller, David A.; Kolbe, Jason J.; Leal, Manuel

    2014-01-01

    Signaling individuals must effectively capture and hold the attention of intended conspecific receivers while limiting eavesdropping by potential predators. A possible mechanism for achieving this balance is for individuals to modulate the physical properties of their signals or to alter the proportion of time spent signaling, depending upon local levels of predation pressure. We test the hypothesis that prey can alter their visual signaling behavior to decrease conspicuousness and potentially limit predation risk via modulation of signal properties or display rate. To do so, we conducted a manipulative experiment in nature to evaluate the possible effect of predation pressure on the physical properties of movement-based signals and on the proportion of time spent signaling by using a well-understood predator–prey system in the Bahamas, the semiarboreal lizard Anolis sagrei, and one of its main predators, the curly-tailed lizard Leiocephalus carinatus. We find that on islands onto which the predator was introduced, male anoles reduce the maximum amplitude of head-bob displays but not the proportion of time spent signaling, in comparison with control islands lacking the predator. This reduction of amplitude also decreases signal active space, which might alter the reproductive success of signaling individuals. We suggest that future studies of predator–prey interactions consider the risk effects generated by changes in signals or signaling behavior to fully determine the influence of predation pressure on the dynamics of prey populations. PMID:24843163

  16. a Universal De-Noising Algorithm for Ground-Based LIDAR Signal

    NASA Astrophysics Data System (ADS)

    Ma, Xin; Xiang, Chengzhi; Gong, Wei

    2016-06-01

    Ground-based lidar, working as an effective remote sensing tool, plays an irreplaceable role in the study of atmosphere, since it has the ability to provide the atmospheric vertical profile. However, the appearance of noise in a lidar signal is unavoidable, which leads to difficulties and complexities when searching for more information. Every de-noising method has its own characteristic but with a certain limitation, since the lidar signal will vary with the atmosphere changes. In this paper, a universal de-noising algorithm is proposed to enhance the SNR of a ground-based lidar signal, which is based on signal segmentation and reconstruction. The signal segmentation serving as the keystone of the algorithm, segments the lidar signal into three different parts, which are processed by different de-noising method according to their own characteristics. The signal reconstruction is a relatively simple procedure that is to splice the signal sections end to end. Finally, a series of simulation signal tests and real dual field-of-view lidar signal shows the feasibility of the universal de-noising algorithm.

  17. Fault diagnosis of motor drives using stator current signal analysis based on dynamic time warping

    NASA Astrophysics Data System (ADS)

    Zhen, D.; Wang, T.; Gu, F.; Ball, A. D.

    2013-01-01

    Electrical motor stator current signals have been widely used to monitor the condition of induction machines and their downstream mechanical equipment. The key technique used for current signal analysis is based on Fourier transform (FT) to extract weak fault sideband components from signals predominated with supply frequency component and its higher order harmonics. However, the FT based method has limitations such as spectral leakage and aliasing, leading to significant errors in estimating the sideband components. Therefore, this paper presents the use of dynamic time warping (DTW) to process the motor current signals for detecting and quantifying common faults in a downstream two-stage reciprocating compressor. DTW is a time domain based method and its algorithm is simple and easy to be embedded into real-time devices. In this study DTW is used to suppress the supply frequency component and highlight the sideband components based on the introduction of a reference signal which has the same frequency component as that of the supply power. Moreover, a sliding window is designed to process the raw signal using DTW frame by frame for effective calculation. Based on the proposed method, the stator current signals measured from the compressor induced with different common faults and under different loads are analysed for fault diagnosis. Results show that DTW based on residual signal analysis through the introduction of a reference signal allows the supply components to be suppressed well so that the fault related sideband components are highlighted for obtaining accurate fault detection and diagnosis results. In particular, the root mean square (RMS) values of the residual signal can indicate the differences between the healthy case and different faults under varying discharge pressures. It provides an effective and easy approach to the analysis of motor current signals for better fault diagnosis of the downstream mechanical equipment of motor drives in the time

  18. Study of weak vibrating signal detection based on chaotic oscillator in MEMS resonant beam sensor

    NASA Astrophysics Data System (ADS)

    Shi, Huichao; Fan, Shangchun; Xing, Weiwei; Sun, Jinhao

    2015-01-01

    In this paper, the application of weak signal detection based on chaotic oscillator is studied in a MEMS resonant beam sensor. Chaotic oscillator can detect weak signal which is submerged in the background of large noise. According to the frequency and phase characteristic of the output vibrating signal, reference current signal with fixed frequency difference and same phase to the output signal is set. Frequency and phase of the signal are fixed by detection resistor which works as a multiplier. By calculating the maximum Lyapunov exponent, detection threshold is obtained, and motion change of detection system is monitored. The results of numerical simulation and experiment show that this method can effectively detect the weak resonant signal and find the resonant frequency accurately by setting the threshold of the chaotic oscillator, and it is immune to the noise.

  19. Effect of Beverages on the Hardness and Tensile Bond Strength of Temporary Acrylic Soft Liners to Acrylic Resin Denture Base

    PubMed Central

    Safari, A; Vojdani, M; Mogharrabi, S; Iraji Nasrabadi, N; Derafshi, R

    2013-01-01

    Statement of Problem: Two potential problems commonly identified with a denture base incorporating a resilient liner are failure of the bond between acrylic resin and soft liner material, and loss of resiliency of the soft liner over time. Since patients may drink different beverages, it is important to evaluate their effects on physical properties of soft lining materials. Purpose: The objective of this in vitro study was to evaluate the effect of different beverages on the hardness of two temporary acrylic-based soft lining materials and their bond strength to the denture base resin. Materials and Method: For the hardness test; a total of 80 rectangular specimens (40mm×10mm×3mm) were fabricated from a heat-polymerized polymethylmethacrylate. Two commercially auto-polymerized acrylic resin-based resilient liners; Coe-Soft and Visco-gel were prepared according to the manufacturers’ instructions and applied on the specimens. For the tensile test, 160 cylindrical specimens (30mm×10mm) were prepared. The liners were added between specimens with a thickness of 3 mm. The specimens of both soft liners were divided into 4 groups (n=10) and immersed in distilled water as the control group, Coca-Cola, 8% and 50% ethanol. All groups were stored in separate containers at 37oC for 12 days. All beverages were changed daily. The hardness was determined using a Shore A durometer and tensile bond strength was determined in a ZwickRoell testing machine at a cross-head speed of 5mm/min. The results were analyzed using two-way ANOVA. Results: There was no significant interaction between the soft liners and the drinks for both hardness (p= 0.748) and bond strength (p= 0.902). There were statistically significant differences between all drinks for both hardness (p< 0.001) and bond strength (p< 0.05). Conclusion: Within the limitations of this study, it seems that drinking Coca-Cola and alcoholic beverages would not be potentially causing any problems for the temporary

  20. Breaking through the strength-ductility trade-off dilemma in an Al-Si-based casting alloy

    PubMed Central

    Dang, B.; Zhang, X.; Chen, Y. Z.; Chen, C. X.; Wang, H. T.; Liu, F.

    2016-01-01

    Al-Si-based casting alloys have a great potential in various industrial applications. Common strengthening strategies on these alloys are accompanied inevitably by sacrifice of ductility, known as strength-ductility trade-off dilemma. Here, we report a simple route by combining rapid solidification (RS) with a post-solidification heat treatment (PHT), i.e. a RS + PHT route, to break through this dilemma using a commercial Al-Si-based casting alloy (A356 alloy) as an example. It is shown that yield strength and elongation to failure of the RS + PHT processed alloy are elevated simultaneously by increasing the cooling rate upon RS, which are not influenced by subsequent T6 heat treatment. Breaking through the dilemma is attributed to the hierarchical microstructure formed by the RS + PHT route, i.e. highly dispersed nanoscale Si particles in Al dendrites and nanoscale Al particles decorated in eutectic Si. Simplicity of the RS + PHT route makes it being suitable for industrial scaling production. The strategy of engineering microstructures offers a general pathway in tailoring mechanical properties of other Al-Si-based alloys. Moreover, the remarkably enhanced ductility of A356 alloy not only permits strengthening further the material by work hardening but also enables possibly conventional solid-state forming of the material, thus extending the applications of such an alloy. PMID:27502444

  1. Breaking through the strength-ductility trade-off dilemma in an Al-Si-based casting alloy

    NASA Astrophysics Data System (ADS)

    Dang, B.; Zhang, X.; Chen, Y. Z.; Chen, C. X.; Wang, H. T.; Liu, F.

    2016-08-01

    Al-Si-based casting alloys have a great potential in various industrial applications. Common strengthening strategies on these alloys are accompanied inevitably by sacrifice of ductility, known as strength-ductility trade-off dilemma. Here, we report a simple route by combining rapid solidification (RS) with a post-solidification heat treatment (PHT), i.e. a RS + PHT route, to break through this dilemma using a commercial Al-Si-based casting alloy (A356 alloy) as an example. It is shown that yield strength and elongation to failure of the RS + PHT processed alloy are elevated simultaneously by increasing the cooling rate upon RS, which are not influenced by subsequent T6 heat treatment. Breaking through the dilemma is attributed to the hierarchical microstructure formed by the RS + PHT route, i.e. highly dispersed nanoscale Si particles in Al dendrites and nanoscale Al particles decorated in eutectic Si. Simplicity of the RS + PHT route makes it being suitable for industrial scaling production. The strategy of engineering microstructures offers a general pathway in tailoring mechanical properties of other Al-Si-based alloys. Moreover, the remarkably enhanced ductility of A356 alloy not only permits strengthening further the material by work hardening but also enables possibly conventional solid-state forming of the material, thus extending the applications of such an alloy.

  2. Practice what you preach: developing person-centred culture in inpatient mental health settings through strengths-based, transformational leadership.

    PubMed

    Beckett, Paul; Field, John; Molloy, Luke; Yu, Nickolas; Holmes, Douglas; Pile, Emily

    2013-08-01

    The experience of nursing staff and consumers in inpatient mental health wards is often reported as being negative. Efforts to improve culture and practice have had limited success, with ineffective leadership, staff resistance, and unresponsive organisational culture identified as common barriers to change. Practice development has been promoted as an approach to developing person-centred culture that enables professional development through participation, learning and empowerment. For person-centred practice to flourish, organisational leadership at all levels must reflect the same principles. In preparation for the opening of a new integrated mental health service, an inpatient mental health team participated in a practice development project. An action research approach was used to facilitate a series of "away days," initially with the nursing team and then other members of the multidisciplinary team (MDT). Transformational leadership principles were adopted in the facilitation of team activities underpinned by strengths and solution-focused practices. Evaluation of the project by staff members was very positive and there was a high level of participation in practice development activities. The project resulted in the creation of a development plan for the ward, which prioritised five key themes: person-centred care, personal recovery, strengths-based principles, and evidence-based and values-based care. The project outcomes highlight the importance of leadership, which parallels the ideals promoted for clinical practice. PMID:23909671

  3. Practice what you preach: developing person-centred culture in inpatient mental health settings through strengths-based, transformational leadership.

    PubMed

    Beckett, Paul; Field, John; Molloy, Luke; Yu, Nickolas; Holmes, Douglas; Pile, Emily

    2013-08-01

    The experience of nursing staff and consumers in inpatient mental health wards is often reported as being negative. Efforts to improve culture and practice have had limited success, with ineffective leadership, staff resistance, and unresponsive organisational culture identified as common barriers to change. Practice development has been promoted as an approach to developing person-centred culture that enables professional development through participation, learning and empowerment. For person-centred practice to flourish, organisational leadership at all levels must reflect the same principles. In preparation for the opening of a new integrated mental health service, an inpatient mental health team participated in a practice development project. An action research approach was used to facilitate a series of "away days," initially with the nursing team and then other members of the multidisciplinary team (MDT). Transformational leadership principles were adopted in the facilitation of team activities underpinned by strengths and solution-focused practices. Evaluation of the project by staff members was very positive and there was a high level of participation in practice development activities. The project resulted in the creation of a development plan for the ward, which prioritised five key themes: person-centred care, personal recovery, strengths-based principles, and evidence-based and values-based care. The project outcomes highlight the importance of leadership, which parallels the ideals promoted for clinical practice.

  4. Breaking through the strength-ductility trade-off dilemma in an Al-Si-based casting alloy.

    PubMed

    Dang, B; Zhang, X; Chen, Y Z; Chen, C X; Wang, H T; Liu, F

    2016-01-01

    Al-Si-based casting alloys have a great potential in various industrial applications. Common strengthening strategies on these alloys are accompanied inevitably by sacrifice of ductility, known as strength-ductility trade-off dilemma. Here, we report a simple route by combining rapid solidification (RS) with a post-solidification heat treatment (PHT), i.e. a RS + PHT route, to break through this dilemma using a commercial Al-Si-based casting alloy (A356 alloy) as an example. It is shown that yield strength and elongation to failure of the RS + PHT processed alloy are elevated simultaneously by increasing the cooling rate upon RS, which are not influenced by subsequent T6 heat treatment. Breaking through the dilemma is attributed to the hierarchical microstructure formed by the RS + PHT route, i.e. highly dispersed nanoscale Si particles in Al dendrites and nanoscale Al particles decorated in eutectic Si. Simplicity of the RS + PHT route makes it being suitable for industrial scaling production. The strategy of engineering microstructures offers a general pathway in tailoring mechanical properties of other Al-Si-based alloys. Moreover, the remarkably enhanced ductility of A356 alloy not only permits strengthening further the material by work hardening but also enables possibly conventional solid-state forming of the material, thus extending the applications of such an alloy. PMID:27502444

  5. The recovery of weak impulsive signals based on stochastic resonance and moving least squares fitting.

    PubMed

    Jiang, Kuosheng; Xu, Guanghua; Liang, Lin; Tao, Tangfei; Gu, Fengshou

    2014-07-29

    In this paper a stochastic resonance (SR)-based method for recovering weak impulsive signals is developed for quantitative diagnosis of faults in rotating machinery. It was shown in theory that weak impulsive signals follow the mechanism of SR, but the SR produces a nonlinear distortion of the shape of the impulsive signal. To eliminate the distortion a moving least squares fitting method is introduced to reconstruct the signal from the output of the SR process. This proposed method is verified by comparing its detection results with that of a morphological filter based on both simulated and experimental signals. The experimental results show that the background noise is suppressed effectively and the key features of impulsive signals are reconstructed with a good degree of accuracy, which leads to an accurate diagnosis of faults in roller bearings in a run-to failure test.

  6. Strength Testing.

    ERIC Educational Resources Information Center

    Londeree, Ben R.

    1981-01-01

    Postural deviations resulting from strength and flexibility imbalances include swayback, scoliosis, and rounded shoulders. Screening tests are one method for identifying strength problems. Tests for the evaluation of postural problems are described, and exercises are presented for the strengthening of muscles. (JN)

  7. Evaluation of shear bond strength of two resin-based composites and glass ionomer cement to pure tricalcium silicate-based cement (Biodentine®)

    PubMed Central

    CANTEKİN, Kenan; AVCİ, Serap

    2014-01-01

    Objectives Tricalcium silicate is the major constituent phase in mineral trioxide aggregate (MTA). It is thus postulated that pure tricalcium silicate can replace the Portland cement component of MTA. The aim of this study was to evaluate bond strength of methacrylate-based (MB) composites, silorane-based (SB) composites, and glass ionomer cement (GIC) to Biodentine® and mineral trioxide aggregate (MTA). Material and Methods Acrylic blocks (n=90, 2 mm high, 5 mm diameter central hole) were prepared. In 45 of the samples, the holes were fully filled with Biodentine® and in the other 45 samples, the holes were fully filled with MTA. The Biodentine® and the MTA samples were randomly divided into 3 subgroups of 15 specimens each: Group-1: MB composite; Group-2: SB composite; and Group-3: GIC. For the shear bond strength (SBS) test, each block was secured in a universal testing machine. Results The highest (17.7±6.2 MPa) and the lowest (5.8±3.2 MPa) bond strength values were recorded for the MB composite-Biodentine® and the GIC-MTA, respectively. Although the MB composite showed significantly higher bond strength to Biodentine (17.7±6.2) than it did to MTA (8.9±5.7) (p<0.001), the SB composite (SB and MTA=7.4±3.3; SB and Biodentine®=8.0±3,6) and GIC (GIC and MTA=5.8±3.2; GIC and Biodentine=6.7±2.6) showed similar bond strength performance with MTA compared with Biodentine (p=0.73 and p=0.38, respectively). Conclusions The new pure tricalcium-based pulp capping, repair, and endodontic material showed higher shear bond scores compared to MTA when used with the MB composite. PMID:25141202

  8. PDGFB-based stem cell gene therapy increases bone strength in the mouse.

    PubMed

    Chen, Wanqiu; Baylink, David J; Brier-Jones, Justin; Neises, Amanda; Kiroyan, Jason B; Rundle, Charles H; Lau, Kin-Hing William; Zhang, Xiao-Bing

    2015-07-21

    Substantial advances have been made in the past two decades in the management of osteoporosis. However, none of the current medications can eliminate the risk of fracture and rejuvenate the skeleton. To this end, we recently reported that transplantation of hematopoietic stem/progenitor cells (HSCs) or Sca1(+) cells engineered to overexpress FGF2 results in a significant increase in lamellar bone matrix formation at the endosteum; but this increase was attended by the development of secondary hyperparathyroidism and severe osteomalacia. Here we switch the therapeutic gene to PDGFB, another potent mitogen for mesenchymal stem cells (MSCs) but potentially safer than FGF2. We found that modest overexpression of PDGFB using a relatively weak phosphoglycerate kinase (PGK) promoter completely avoided osteomalacia and secondary hyperparathyroidism, and simultaneously increased trabecular bone formation and trabecular connectivity, and decreased cortical porosity. These effects led to a 45% increase in the bone strength. Transplantation of PGK-PDGFB-transduced Sca1(+) cells increased MSC proliferation, raising the possibility that PDGF-BB enhances expansion of MSC in the vicinity of the hematopoietic niche where the osteogenic milieu propels the differentiation of MSCs toward an osteogenic destination. Our therapy should have potential clinical applications for patients undergoing HSC transplantation, who are at high risk for osteoporosis and bone fractures after total body irradiation preconditioning. It could eventually have wider application once the therapy can be applied without the preconditioning.

  9. Development of an extra-high strength powder metallurgy nickel-base superalloy

    NASA Technical Reports Server (NTRS)

    Kent, W. B.

    1977-01-01

    A program was conducted to optimize the composition of NASA IIb-11, an alloy originally developed as a wrought material, for thermal stability and to determine the feasibility for producing the alloy using powder metallurgy techniques. Seven compositions were melted and atomized, hot isostatically pressed, cross rolled to disks and heat treated. Tensile and stress rupture properties from room temperature to 870 C (1600 F) were determined in addition to thermal stability characteristics. Processing variables included hot isostatic pressing parameters and handling, cross rolling procedures and heat treatment cycles. NASA IIb-11E displayed the best combination of overall properties for service as a 760 C (1400 F) disk material. Its composition is 0.06 C, 8.5 Cr, 9.0 Co, 2.0 Mo, 7.1 W, 6.6 Ta, 4.5 Al, 0.75 Ti, 0.5 V, 0.7 Hf, 0.01 B, 0.05 Zr and balance Ni. While the alloy exhibits the highest 760 C (1400 F) rupture strength reported for any powder metallurgy disk alloy to date, additional studies to further evaluate the effects of heat treatment may be required. The alloy is not susceptible to topologically close-packed phase formation during thermal exposure at 870 C (1600 F) for 1,500 hours, but its mechanical property levels are lowered due to grain boundary carbide formation.

  10. Performance of SOPPA-based methods in the calculation of vertical excitation energies and oscillator strengths

    NASA Astrophysics Data System (ADS)

    Sauer, Stephan P. A.; Pitzner-Frydendahl, Henrik F.; Buse, Mogens; Jensen, Hans Jørgen Aa.; Thiel, Walter

    2015-07-01

    We present two new modifications of the second-order polarization propagator approximation (SOPPA), SOPPA(SCS-MP2) and SOPPA(SOS-MP2), which employ either spin-component-scaled or scaled opposite-spin MP2 correlation coefficients instead of the regular MP2 coefficients. The performance of these two methods, the original SOPPA method as well as SOPPA(CCSD) and RPA(D) in the calculation of vertical electronic excitation energies and oscillator strengths is investigated for a large benchmark set of 28 medium-sized molecules with 139 singlet and 71 triplet excited states. The results are compared with the corresponding CC3 and CASPT2 results from the literature for both the TZVP set and the larger and more diffuse aug-cc-pVTZ basis set. In addition, the results with the aug-cc-pVTZ basis set are compared with the theoretical best estimates for this benchmark set. We find that the original SOPPA method gives overall the smallest mean deviations from the reference values and the most consistent results.

  11. Signal Reconstruction from Nonuniformly Spaced Samples Using Evolutionary Slepian Transform-Based POCS

    NASA Astrophysics Data System (ADS)

    Oh, Jinsung; Senay, Seda; Chaparro, LuisF

    2010-12-01

    We consider the reconstruction of signals from nonuniformly spaced samples using a projection onto convex sets (POCSs) implemented with the evolutionary time-frequency transform. Signals of practical interest have finite time support and are nearly band-limited, and as such can be better represented by Slepian functions than by sinc functions. The evolutionary spectral theory provides a time-frequency representation of nonstationary signals, and for deterministic signals the kernel of the evolutionary representation can be derived from a Slepian projection of the signal. The representation of low pass and band pass signals is thus efficiently done by means of the Slepian functions. Assuming the given nonuniformly spaced samples are from a signal satisfying the finite time support and the essential band-limitedness conditions with a known center frequency, imposing time and frequency limitations in the evolutionary transformation permit us to reconstruct the signal iteratively. Restricting the signal to a known finite time and frequency support, a closed convex set, the projection generated by the time-frequency transformation converges into a close approximation to the original signal. Simulation results illustrate the evolutionary Slepian-based transform in the representation and reconstruction of signals from irregularly-spaced and contiguous lost samples.

  12. Target- and Mechanism-Based Therapeutics for Neurodegenerative Diseases: Strength in Numbers

    PubMed Central

    Trippier, Paul C.; Labby, Kristin Jansen; Hawker, Dustin D.; Mataka, Jan J.; Silverman, Richard B.

    2013-01-01

    The development of new therapeutics for the treatment of neurodegenerative pathophysiologies currently stands at a crossroads. This presents an opportunity to transition future drug discovery efforts to target disease modification, an area in which much still remains unknown. In this Perspective we examine recent progress in the areas of neurodegenerative drug discovery, focusing on some of the most common targets and mechanisms; N-methyl-d-aspartic acid (NMDA) receptors, voltage gated calcium channels (VGCCs), neuronal nitric oxide synthase (nNOS), oxidative stress from reactive oxygen species, and protein aggregation. These represent the key players identified in neurodegeneration and are part of a complex, intertwined signaling cascade. The synergistic delivery of two or more compounds directed against these targets, along with the design of small molecules with multiple modes of action should be explored in pursuit of more effective clinical treatments for neurodegenerative diseases. PMID:23458846

  13. Signal analysis of accelerometry data using gravity-based modeling

    NASA Astrophysics Data System (ADS)

    Davey, Neil P.; James, Daniel A.; Anderson, Megan E.

    2004-03-01

    Triaxial accelerometers have been used to measure human movement parameters in swimming. Interpretation of data is difficult due to interference sources including interaction of external bodies. In this investigation the authors developed a model to simulate the physical movement of the lower back. Theoretical accelerometery outputs were derived thus giving an ideal, or noiseless dataset. An experimental data collection apparatus was developed by adapting a system to the aquatic environment for investigation of swimming. Model data was compared against recorded data and showed strong correlation. Comparison of recorded and modeled data can be used to identify changes in body movement, this is especially useful when cyclic patterns are present in the activity. Strong correlations between data sets allowed development of signal processing algorithms for swimming stroke analysis using first the pure noiseless data set which were then applied to performance data. Video analysis was also used to validate study results and has shown potential to provide acceptable results.

  14. Model-based detector and extraction of weak signal frequencies from chaotic data.

    PubMed

    Zhou, Cangtao; Cai, Tianxing; Heng Lai, Choy; Wang, Xingang; Lai, Ying-Cheng

    2008-03-01

    Detecting a weak signal from chaotic time series is of general interest in science and engineering. In this work we introduce and investigate a signal detection algorithm for which chaos theory, nonlinear dynamical reconstruction techniques, neural networks, and time-frequency analysis are put together in a synergistic manner. By applying the scheme to numerical simulation and different experimental measurement data sets (Henon map, chaotic circuit, and NH(3) laser data sets), we demonstrate that weak signals hidden beneath the noise floor can be detected by using a model-based detector. Particularly, the signal frequencies can be extracted accurately in the time-frequency space. By comparing the model-based method with the standard denoising wavelet technique as well as supervised principal components analysis detector, we further show that the nonlinear dynamics and neural network-based approach performs better in extracting frequencies of weak signals hidden in chaotic time series.

  15. Expanding the vision: the strengths-based, community-oriented child and adolescent psychiatrist working in schools.

    PubMed

    Kriechman, Avron; Salvador, Melina; Adelsheim, Steven

    2010-01-01

    Because the majority of children with mental health needs are most likely to receive treatment in a school setting, there is a long history of linking child and adolescent psychiatrists to schools. Psychiatrists traditionally have been involved in assessing, diagnosing, and treating the severely mentally ill or consulting with school-based providers. With no end in sight to the dearth of child and adolescent psychiatrists, not to mention child and adolescent behavioral health providers in other disciplines, this role has been broadened in recent years by several programs in which the child and adolescent psychiatrist provides flexible, population-based, systemic, and context-specific approaches to working in schools. In this article, the authors first review some of the traditional roles for child and adolescent psychiatrists working in school mental health settings. Then 2 national programs are highlighted, which successfully integrate psychiatrist trainees into comprehensive school mental health programs. The theoretical approach to a specific community-oriented, strengths-based model for school mental health support used in New Mexico by the University of New Mexico (UNM) Psychiatry Department's Center for Rural and Community Behavioral Health school telepsychiatry program, which supports rural and frontier school mental health programs and school-based health centers, is discussed in detail. The UNM model involves a strength-and resiliency-based collaboration between the child and adolescent psychiatrist, students, families, educators, and those who support them. The psychiatrist co-creates a "community of concern" and support for students, including not only customary participants such as parents, educators, and health care providers but also peers, families of choice, lay professionals, community gatekeepers, and others identified by the student as critical to his or her well-being. The advantages for child and adolescent psychiatry trainees being exposed to

  16. Note: The design of thin gap chamber simulation signal source based on field programmable gate array

    SciTech Connect

    Hu, Kun; Wang, Xu; Li, Feng; Jin, Ge; Lu, Houbing; Liang, Futian

    2015-01-15

    The Thin Gap Chamber (TGC) is an important part of ATLAS detector and LHC accelerator. Targeting the feature of the output signal of TGC detector, we have designed a simulation signal source. The core of the design is based on field programmable gate array, randomly outputting 256-channel simulation signals. The signal is generated by true random number generator. The source of randomness originates from the timing jitter in ring oscillators. The experimental results show that the random number is uniform in histogram, and the whole system has high reliability.

  17. Intersecting Asset-Based Service, Strengths, and Mentoring for Socially Responsible Leadership.

    PubMed

    Hastings, Lindsay

    2016-06-01

    Grounded in a youth leadership and mentoring program, this chapter discusses the value of asset-based community development from the service-learning literature and the concept of generativity from the leadership development literature. PMID:27150907

  18. Dike Strength Analysis on a Regional Scale Based On a Stochastic Subsoil Model

    NASA Astrophysics Data System (ADS)

    Koelewijn, A. R.; Vastenburg, E. W.

    2013-12-01

    [Knoeff et al. 2011] J.G. Knoeff, E.W. Vastenburg, G.A. van den Ham & J. Lopez de la Cruz, Automated levee flood risk management, 5th Int. Conf. on Flood Management, Tokyo, 2011 [Koelewijn et al. 2011] A.R. Koelewijn, G.A.M. Kruse & J. Pruiksma, Stochastic subsoil modelling - first set-up of the model and reliability analyses, report 12042000-002-HYE-0001, Deltares, Delft, 2011 [In Dutch] [Lam et al. 2013] K.S. Lam, P.W. Gill & L.W.A. Zwang, Implementation of new levee strength modules for continuous safety assessments, Comprehensive Flood Risk Managment, Taylor & Francis, London, 2013, 317-326. Dike sections with stochastic subsoil profiles.

  19. Evaluation of bond strength between leucite-based and lithium disilicate-based ceramics to dentin after cementation with conventional and self-adhesive resin agents.

    PubMed

    Rigolin, Fernando J; Miranda, Milton E; Flório, Flávia M; Basting, Roberta T

    2014-01-01

    The aim of this study was to compare the microtensile bond strength of two heat-pressed ceramics (leucite-based--IPS Empress Esthetic/Ivoclar Vivadent, and lithium disilicate-based --IPS e.max Press/Ivoclar Vivadent) to dentin with the use of conventional and self-adhesive resin cements. The occlusal surface of 60 intact human molars was removed and the dentin was exposed. Ceramic blocks were cemented randomly with regard to the cementation systems (n = 10): conventional dual resin cement (Variolink II/Ivoclar Vivadent), conventional self-polymerizing resin cement (Multilink/Ivoclar Vivadent), and dual self-adhesive resin cement (RelyX U100/3M ESPE). The dual cementation systems were photoactivated with a LED light device (Radii Cal, SDI) for 40 seconds. The specimens were sectioned to obtain sticks of approximately 1 mm2 for microtensile tests on a universal testing machine (EMIC). The type of fracture was analyzed under a scanning electron microscope. The Analysis of Variance (ANOVA) and the Tukey test (alpha = 0.05) showed that there was no difference between types of ceramic. Average microtensile bond strength was higher for the conventional dual resin cement (Variolink II) and the self-adhesive dual resin cement (RelyX U100), despite greater prevalence of premature loss of the sticks with the latter. Average bond strength was lower when the conventional self-polymerizing resin cement (Multilink) was used. Leucite-based and lithium disilicate-based cements present similar bond strength to the dentin with conventional dual resin cement (Variolink II) and a dual self-adhesive cement (RelyX U100).

  20. A Signal-Inducing Bone Cement for Magnetic Resonance Imaging-Guided Spinal Surgery Based on Hydroxyapatite and Polymethylmethacrylate

    SciTech Connect

    Wichlas, Florian Seebauer, Christian J.; Schilling, Rene; Rump, Jens; Chopra, Sascha S.; Walter, Thula; Teichgraeber, Ulf K. M.; Bail, Hermann J.

    2012-06-15

    The aim of this study was to develop a signal-inducing bone cement for magnetic resonance imaging (MRI)-guided cementoplasty of the spine. This MRI cement would allow precise and controlled injection of cement into pathologic lesions of the bone. We mixed conventional polymethylmethacrylate bone cement (PMMA; 5 ml methylmethacrylate and 12 g polymethylmethacrylate) with hydroxyapatite (HA) bone substitute (2-4 ml) and a gadolinium-based contrast agent (CA; 0-60 {mu}l). The contrast-to-noise ratio (CNR) of different CA doses was measured in an open 1.0-Tesla scanner for fast T1W Turbo-Spin-Echo (TSE) and T1W TSE pulse sequences to determine the highest signal. We simulated MRI-guided cementoplasty in cadaveric spines. Compressive strength of the cements was tested. The highest CNR was (1) 87.3 (SD 2.9) in fast T1W TSE for cements with 4 {mu}l CA/ml HA (4 ml) and (2) 60.8 (SD 2.4) in T1W TSE for cements with 1 {mu}l CA/ml HA (4 ml). MRI-guided cementoplasty in cadaveric spine was feasible. Compressive strength decreased with increasing amounts of HA from 46.7 MPa (2 ml HA) to 28.0 MPa (4 ml HA). An MRI-compatible cement based on PMMA, HA, and CA is feasible and clearly visible on MRI images. MRI-guided spinal cementoplasty using this cement would permit direct visualization of the cement, the pathologic process, and the anatomical surroundings.

  1. Entrepreneurship education: A strength-based approach to substance use and suicide prevention for American Indian adolescents.

    PubMed

    Tingey, Lauren; Larzelere-Hinton, Francene; Goklish, Novalene; Ingalls, Allison; Craft, Todd; Sprengeler, Feather; McGuire, Courtney; Barlow, Allison

    2016-01-01

    American Indian (AI) adolescents suffer the largest disparities in substance use and suicide. Predominating prevention models focus primarily on risk and utilize deficit-based approaches. The fields of substance use and suicide prevention research urge for positive youth development frameworks that are strength based and target change at individual and community levels. Entrepreneurship education is an innovative approach that reflects the gap in available programs. This paper describes the development and evaluation of a youth entrepreneurship education program in partnership with one AI community. We detail the curriculum, process evaluation results, and the randomized controlled trial evaluating its efficacy for increasing protective factors. Lessons learned may be applicable to other AI communities. PMID:27383095

  2. Revisiting an old concept: the coupled oscillator model for VCD. Part 1: the generalised coupled oscillator mechanism and its intrinsic connection to the strength of VCD signals.

    PubMed

    Nicu, Valentin Paul

    2016-08-01

    Motivated by the renewed interest in the coupled oscillator (CO) model for VCD, in this work a generalised coupled oscillator (GCO) expression is derived by introducing the concept of a coupled oscillator origin. Unlike the standard CO expression, the GCO expression is exact within the harmonic approximation. Using two illustrative example molecules, the theoretical concepts introduced here are demonstrated by performing a GCO decomposition of the rotational strengths computed using DFT. This analysis shows that: (1) the contributions to the rotational strengths that are normally neglected in the standard CO model can be comparable to or larger than the CO contribution, and (2) the GCO mechanism introduced here can affect the VCD intensities of all types of modes in symmetric and asymmetric molecules.

  3. Phosphoric acid-etching promotes bond strength and formation of acid-base resistant zone on enamel.

    PubMed

    Li, N; Nikaido, T; Alireza, S; Takagaki, T; Chen, J-H; Tagami, J

    2013-01-01

    This study examined the effect of phosphoric acid (PA) etching on the bond strength and acid-base resistant zone (ABRZ) formation of a two-step self-etching adhesive (SEA) system to enamel. An etch-and-rinse adhesive (EAR) system Single Bond (SB) and a two-step SEA system Clearfil SE Bond (SE) were used. Human teeth were randomly divided into four groups according to different adhesive treatments: 1) SB; 2) SE; 3) 35% PA etching→SE primer→SE adhesive (PA/SEp+a); (4) 35% PA etching→SE adhesive (PA/SEa). Microshear bond strength to enamel was measured and then statistically analyzed using one-way analysis of variance and the Tukey honestly significant difference test. The failure mode was recorded and analyzed by χ( 2 ) test. The etching pattern of the enamel surface was observed with scanning electron microscope (SEM). The bonded interface was exposed to a demineralizing solution (pH=4.5) for 4.5 hours and then 5% sodium hypochlorite with ultrasonication for 30 minutes. After argon-ion etching, the interfacial ultrastructure was observed using SEM. The microshear bond strength to enamel of the SE group was significantly lower (p<0.05) than that of the three PA-etched groups, although the latter three were not significantly different from one another. The ABRZ was detected in all the groups. In morphological observation, the ABRZ in the three PA-etched groups were obviously thicker compared with the SE group with an irregular wave-shaped edge.

  4. A wavelet-based baseline drift correction method for grounded electrical source airborne transient electromagnetic signals

    NASA Astrophysics Data System (ADS)

    Wang, Yuan 1Ji, Yanju 2Li, Suyi 13Lin, Jun 12Zhou, Fengdao 1Yang, Guihong

    2013-09-01

    A grounded electrical source airborne transient electromagnetic (GREATEM) system on an airship enjoys high depth of prospecting and spatial resolution, as well as outstanding detection efficiency and easy flight control. However, the movement and swing of the front-fixed receiving coil can cause severe baseline drift, leading to inferior resistivity image formation. Consequently, the reduction of baseline drift of GREATEM is of vital importance to inversion explanation. To correct the baseline drift, a traditional interpolation method estimates the baseline `envelope' using the linear interpolation between the calculated start and end points of all cycles, and obtains the corrected signal by subtracting the envelope from the original signal. However, the effectiveness and efficiency of the removal is found to be low. Considering the characteristics of the baseline drift in GREATEM data, this study proposes a wavelet-based method based on multi-resolution analysis. The optimal wavelet basis and decomposition levels are determined through the iterative comparison of trial and error. This application uses the sym8 wavelet with 10 decomposition levels, and obtains the approximation at level-10 as the baseline drift, then gets the corrected signal by removing the estimated baseline drift from the original signal. To examine the performance of our proposed method, we establish a dipping sheet model and calculate the theoretical response. Through simulations, we compare the signal-to-noise ratio, signal distortion, and processing speed of the wavelet-based method and those of the interpolation method. Simulation results show that the wavelet-based method outperforms the interpolation method. We also use field data to evaluate the methods, compare the depth section images of apparent resistivity using the original signal, the interpolation-corrected signal and the wavelet-corrected signal, respectively. The results confirm that our proposed wavelet-based method is an

  5. Finite element study on modification of bracket base and its effects on bond strength

    PubMed Central

    Shyagali, Tarulatha R.; Bhayya, Deepak P.; Urs, Chandralekha B.; Subramaniam, Shashikala

    2015-01-01

    OBJECTIVE: This article aims to analyze the difference in stresses generated in the bracket-cement-tooth system by means of a peel load in single and double-mesh bracket bases using a three-dimensional finite element computer model. MATERIAL AND METHODS: A three-dimensional finite element model of the bracket-cement-tooth system was constructed and consisted of 40,536 bonds and 49,201 finite elements using a commercial mesh generating programmer (ANSYS 7.0). Both single and double-mesh bracket bases were modified by varying the diameter from 100-400 µm progressively, and the spacing between the mesh wires was kept at 300 µm for each diameter of wire. A peel load was applied on the model to study the stresses generated in different layers. RESULTS: In case of double-mesh bracket base, there was reduction in stress generation at the enamel in comparison to single-mesh bracket base. There was no difference in stress generated at the bracket layer between single and double-mesh bracket bases. At the impregnated wire mesh (IWM), layer stresses increased as the wire diameter of the mesh increased. CONCLUSION: Results show that bracket design modification can improve bonding abilities and simultaneously reduce enamel damage while debonding. These facts may be used in bringing about the new innovative bracket designs for clinical use. PMID:25992991

  6. Comparative evaluation of shear bond strengths of veneering porcelain to base metal alloy and zirconia substructures before and after aging – An in vitro study

    PubMed Central

    Sreekala, Laju; Narayanan, Mahesh; Eerali, Sunil M.; Eerali, Susil M.; Varghese, Joju; Zainaba Fathima, A. l.

    2015-01-01

    Objective: The aim of this study was to evaluate and compare the shear bond strength of veneering porcelain to base metal alloy and zirconia substructures before and after aging. Scanning electron microscopy (SEM) was used to determine the failure pattern. Materials and Methods: Twenty rectangular blocks (9 mm length × 4 mm height × 4 mm width) of base metal alloy (Bellabond plus, Bego, Germany) and zirconia (Will ceramZ zirconia K block) were fabricated for shear bond strength test. Surface of the base metal alloy block (4 mm × 4 mm area) was veneered with corresponding veneering porcelain (Ivoclar, IPS classic, vivadent). Similarly, surface of the zirconia rectangular block (4 mm × 4 mm) was veneered with corresponding veneering ceramic (Cercon ceram kiss, Degudent). Out of forty rectangular porcelain veneered core specimen, ten porcelain veneered base metal alloy specimen and ten porcelain veneered zirconia specimen were immersed in water at 37°C for one month to simulate the oral environment. Results: On comparison, the highest shear bond strength value was obtained in porcelain veneered base metal alloy before aging group followed by porcelain veneered base metal alloy after aging group, Porcelain veneered zirconia before aging group, porcelain veneered zirconia after aging group. SEM analysis revealed predominantly cohesive failure of veneering ceramic in all groups. Conclusion: Porcelain veneered base metal alloy samples showed highest shear bond strength than porcelain veneered zirconia samples. Study concluded that aging had an influence on shear bond strength. Shear bond strength was found to be decreasing after aging. SEM analysis revealed cohesive failure of veneering ceramic in all groups suggestive of higher bond strength of the interface than cohesive strength of ceramic. Hence, it was concluded that veneering ceramic was the weakest link. PMID:26942121

  7. Higher-order-statistics-based radial basis function networks for signal enhancement.

    PubMed

    Lin, Bor-Shyh; Lin, Bor-Shing; Chong, Fok-Ching; Lai, Feipei

    2007-05-01

    In this paper, a higher-order-statistics (HOS)-based radial basis function (RBF) network for signal enhancement is introduced. In the proposed scheme, higher order cumulants of the reference signal were used as the input of HOS-based RBF. An HOS-based supervised learning algorithm, with mean square error obtained from higher order cumulants of the desired input and the system output as the learning criterion, was used to adapt weights. The motivation is that the HOS can effectively suppress Gaussian and symmetrically distributed non-Gaussian noise. The influence of a Gaussian noise on the input of HOS-based RBF and the HOS-based learning algorithm can be mitigated. Simulated results indicate that HOS-based RBF can provide better performance for signal enhancement under different noise levels, and its performance is insensitive to the selection of learning rates. Moreover, the efficiency of HOS-based RBF under the nonstationary Gaussian noise is stable.

  8. DOA estimation of coherent wideband signals based on extended TOPS algorithm

    NASA Astrophysics Data System (ADS)

    Guo, Rui; Li, Weixing; Zhang, Yue; Chen, Zengping

    2015-12-01

    In this paper, we present a new direction of arrival (DOA) estimation algorithm for coherent wideband signals. This algorithm is based on the test of orthogonality of projected subspaces (TOPS) method which will fail to work in real environments where signals are highly correlated or coherent due to multipath propagation. In order to overcome the disadvantage, we combine spatial smoothing techniques with TOPS method so that the rank of covariance matrix is equal to the number of signal sources even signals received are coherent. Unlike other coherent wideband methods, such as the coherent signal subspace method (CSSM) and WAVES, the new method does not require any initial DOA estimation, thus avoiding errors brought by incorrect initial values. Simulations on computer and experiments in the anechoic chamber based on an 8-elements digital array radar test-bed operating at L & S band are carried out. Simulation and experimental results validate the effectiveness of proposed algorithm.

  9. Does hydrotherapy improve strength and physical function in patients with osteoarthritis—a randomised controlled trial comparing a gym based and a hydrotherapy based strengthening programme

    PubMed Central

    Foley, A; Halbert, J; Hewitt, T; Crotty, M

    2003-01-01

    Objective: To compare the effects of a hydrotherapy resistance exercise programme with a gym based resistance exercise programme on strength and function in the treatment of osteoarthritis (OA). Design: Single blind, three arm, randomised controlled trial. Subjects: 105 community living participants aged 50 years and over with clinical OA of the hip or knee. Methods: Participants were randomised into one of three groups: hydrotherapy (n = 35), gym (n = 35), or control (n = 35). The two exercising groups had three exercise sessions a week for six weeks. At six weeks an independent physiotherapist unaware of the treatment allocation performed all outcome assessments (muscle strength dynamometry, six minute walk test, WOMAC OA Index, total drugs, SF-12 quality of life, Adelaide Activities Profile, and the Arthritis Self-Efficacy Scale). Results: In the gym group both left and right quadriceps significantly increased in strength compared with the control group, and right quadriceps strength was also significantly better than in the hydrotherapy group. The hydrotherapy group increased left quadriceps strength only at follow up, and this was significantly different from the control group. The hydrotherapy group was significantly different from the control group for distance walked and the physical component of the SF-12. The gym group was significantly different from the control group for walk speed and self efficacy satisfaction. Compliance rates were similar for both exercise groups, with 84% of hydrotherapy and 75% of gym sessions attended. There were no differences in drug use between groups over the study period. Conclusion: Functional gains were achieved with both exercise programmes compared with the control group. PMID:14644853

  10. Strength in Numbers: A Multidisciplinary, Project-Based Course in Introductory Statistics

    ERIC Educational Resources Information Center

    Dierker, Lisa; Kaparakis, Emmanuel; Rose, Jennifer; Selya, Arielle; Beveridge, David

    2012-01-01

    This paper describes a multi-disciplinary, project-based course. The course is aimed at providing greater curricular access to applied statistics for students across both divisional and departmental boundaries and includes lecture and laboratory components as well as intensive individualized instructor and peer support. Learning materials and…

  11. Community-based strength training improves physical function in older women and arthritis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exercise is recognized as a mainstay treatment of arthritis, yet more than 40% of adults with arthritis report no leisure time physical activity participation. The Centers for Disease Control and Prevention is working to identify and promote evidence-based physical activity programs to improve physi...

  12. The Spirit of Culture: Applying Cultural Competency to Strength-Based Youth Development.

    ERIC Educational Resources Information Center

    Lucero, Maria Guajardo

    Applying the research-based developmental assets list of 40 positive relationships, experiences, and values as a framework for positive youth development provides communities with a set of factors associated with increased healthy behaviors and fewer high-risk behaviors. Beginning with a question regarding the applicability of this model for youth…

  13. A mesoscale strength model for silica-filled polydimethylsiloxane based on atomistic forces obtained from molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Hanson, D. E.

    2000-11-01

    We present a novel mesoscale model that describes the tensile stress of silica-filled polydimethylsiloxane (PDMS) under elongation. The model is based on atomistic simulations of a single chain of PDMS, interacting with itself and/or a hydroxylated silica surface. These simulations provide estimates of the microscopic forces required to stretch or uncoil a chain of PDMS, or detach it from a silica surface. For both stretching and detachment, we find that the internal potential energy is linear with the distance the chain end is moved, albeit with differing slopes. From these calculations and recent atomic force microscopy (AFM) experiments, we conclude that the forces are constant. We apply this analysis to the case of uncrosslinked, silica-filled PDMS systems and develop a mesoscale, inter-particle strength model. The strength model includes the atomistic forces determined from the simulations, a small entropic component, and a Gaussian probability distribution to describe the distribution of chain lengths of PDMS strands connecting two silica particles and the chain lengths in the free ends. We obtain an analytic stress/strain expression whose predictions agree with experiment. This model also suggests mechanisms to explain the phenomena of hysteresis and permanent set.

  14. Injectable citrate-based mussel-inspired tissue bioadhesives with high wet strength for sutureless wound closure.

    PubMed

    Mehdizadeh, Mohammadreza; Weng, Hong; Gyawali, Dipendra; Tang, Liping; Yang, Jian

    2012-11-01

    The existing surgical adhesives are not ideal for wet tissue adhesion required in many surgeries such as those for internal organs. Developing surgical adhesives with strong wet tissue adhesion, controlled degradability and mechanical properties, and excellent biocompatibility has been a significant challenge. Herein, learning from nature, we report a one-step synthesis of a family of injectable citrate-based mussel-inspired bioadhesives (iCMBAs) for surgical use. Within the formulations investigated, iCMBAs showed 2.5-8.0 folds stronger wet tissue adhesion strength over the clinically used fibrin glue, demonstrated controlled degradability and tissue-like elastomeric mechanical properties, and exhibited excellent cyto/tissue-compatibility both in vitro and in vivo. iCMBAs were able to stop bleeding instantly and suturelessly, and close wounds (2 cm long×0.5 cm deep) created on the back of Sprague-Dawley rats, which is impossible when using existing gold standard, fibrin glue, due to its weak wet tissue adhesion strength. Equally important, the new bioadhesives facilitate wound healing, and are completely degraded and absorbed without eliciting significant inflammatory response. Our results support that iCMBA technology is highly translational and could have broad impact on surgeries where surgical tissue adhesives, sealants, and hemostatic agents are used.

  15. Microtensile bond strength of a resin-based fissure sealant to Er,Cr:YSGG laser-etched primary enamel.

    PubMed

    Sungurtekin-Ekci, Elif; Oztas, Nurhan

    2016-05-01

    The aim of this study was to evaluate the effect of Er,Cr:YSGG laser pre-treatment alone, or associated with acid-etching, on the microtensile bond strength of a resin-based fissure sealant to primary enamel. Twenty-five human primary molars were randomly divided into five groups including (1) 35 % acid etching, (2) 2.5-W laser etching, (3) 3.5-W laser etching, (4) 2.5-W laser etching + acid etching, and (5) 3.5-W laser etching + acid etching. Er,Cr:YSGG laser was used at a wavelength of 2.780 nm and pulse duration of 140-200 μs with a repetition rate of 20 Hz. Following surface pre-treatment, the fissure sealant (ClinPro™, 3M Dental Products) was applied. Each tooth was sectioned and subjected to microtensile testing. Kruskal-Wallis test was used for statistical analysis. The level of significance was set at p < 0.05. The microtensile bond strength values of group 1 were significantly higher than those of group 2, while no statistically significant difference was detected between groups 1, 3, 4, and 5. It was concluded that 3.5-W laser etching produced results comparable to conventional acid etching technique, whereas 2.5-W laser etching was not able to yield adequate bonding performance.

  16. SEMICONDUCTOR DEVICES Intrinsic stability of an HBT based on a small signal equivalent circuit model

    NASA Astrophysics Data System (ADS)

    Yanhu, Chen; Huajun, Shen; Xinyu, Liu; Huijun, Li; Hui, Xu; Ling, Li

    2010-12-01

    Intrinsic stability of the heterojunction bipolar transistor (HBT) was analyzed and discussed based on a small signal equivalent circuit model. The stability factor of the HBT device was derived based on a compact T-type small signal equivalent circuit model of the HBT. The effect of the mainly small signal model parameters of the HBT on the stability of the HBT was thoroughly examined. The discipline of parameter optimum to improve the intrinsic stability of the HBT was achieved. The theoretic analysis results of the stability were also used to explain the experimental results of the stability of the HBT and they were verified by the experimental results.

  17. Joint Estimation of Time-Frequency Signature and DOA Based on STFD for Multicomponent Chirp Signals

    PubMed Central

    Zhao, Ziyue; Liu, Congfeng

    2014-01-01

    In the study of the joint estimation of time-frequency signature and direction of arrival (DOA) for multicomponent chirp signals, an estimation method based on spatial time-frequency distributions (STFDs) is proposed in this paper. Firstly, array signal model for multicomponent chirp signals is presented and then array processing is applied in time-frequency analysis to mitigate cross-terms. According to the results of the array processing, Hough transform is performed and the estimation of time-frequency signature is obtained. Subsequently, subspace method for DOA estimation based on STFD matrix is achieved. Simulation results demonstrate the validity of the proposed method. PMID:27382610

  18. Signaling events during male germ cell differentiation: bases and perspectives.

    PubMed

    Berruti, G

    1998-11-01

    points has been the matter of several more and less recent reviews to which the present author hands back in the course of this note. However all these points, although topics of separate and extensive treatises, are conceptually jointed by a 'leit-motiv', that is, the intracellular transduction of an exogenous signal evoking a specific stimulatory/inhibitory, proliferative/differentiative event. The spirit with which the present author interpreted this minireview was to recall some points to which to draw attention having as a scenario the complex process of male germ cell differentiation in mammals.

  19. Group precipitation and age hardening of nanostructured Fe-based alloys with ultra-high strengths

    DOE PAGES

    Jiao, Z. B.; Luan, J. H.; Miller, M. K.; Yu, C. Y.; Liu, C. T.

    2016-02-19

    The precipitation of nanoparticles plays a key role in determining the properties of many structural materials, and the understanding of their formation and stabilization mechanisms has been a long standing interest in the material field. However, the critical issues involving the group precipitation of various nanoparticles and their cooperative hardening mechanism remain elusive in the newly discovered Fe-based alloys with nanostructures. Here we quantitatively elucidate the nucleation mechanism, evolution kinetics and hardening effects of the group-precipitated nanoparticles in the Fe-Cu-Ni-Al-based alloys by atom probe tomography together with both first-principles and thermodynamic calculations. Our results provide the compelling evidence for twomore » interesting but complex group precipitation pathways of nanoparticles, i.e., the Cu-rich and NiAl-based precipitations. Lastly, the co-existence of the two precipitation pathways plays a key role in age hardening kinetics and ultimately enhances the hardening response, as compared to the single particle type of strengthening, therefore providing an effective new approach for strengthening materials for structural applications.« less

  20. Group precipitation and age hardening of nanostructured Fe-based alloys with ultra-high strengths.

    PubMed

    Jiao, Z B; Luan, J H; Miller, M K; Yu, C Y; Liu, C T

    2016-02-19

    The precipitation of nanoparticles plays a key role in determining the properties of many structural materials, and the understanding of their formation and stabilization mechanisms has been a long standing interest in the material field. However, the critical issues involving the group precipitation of various nanoparticles and their cooperative hardening mechanism remain elusive in the newly discovered Fe-based alloys with nanostructures. Here we quantitatively elucidate the nucleation mechanism, evolution kinetics and hardening effects of the group-precipitated nanoparticles in the Fe-Cu-Ni-Al-based alloys by atom probe tomography together with both first-principles and thermodynamic calculations. Our results provide the compelling evidence for two interesting but complex group precipitation pathways of nanoparticles, i.e., the Cu-rich and NiAl-based precipitations. The co-existence of the two precipitation pathways plays a key role in age hardening kinetics and ultimately enhances the hardening response, as compared to the single particle type of strengthening, therefore providing an effective new approach for strengthening materials for structural applications.

  1. Group precipitation and age hardening of nanostructured Fe-based alloys with ultra-high strengths

    NASA Astrophysics Data System (ADS)

    Jiao, Z. B.; Luan, J. H.; Miller, M. K.; Yu, C. Y.; Liu, C. T.

    2016-02-01

    The precipitation of nanoparticles plays a key role in determining the properties of many structural materials, and the understanding of their formation and stabilization mechanisms has been a long standing interest in the material field. However, the critical issues involving the group precipitation of various nanoparticles and their cooperative hardening mechanism remain elusive in the newly discovered Fe-based alloys with nanostructures. Here we quantitatively elucidate the nucleation mechanism, evolution kinetics and hardening effects of the group-precipitated nanoparticles in the Fe-Cu-Ni-Al-based alloys by atom probe tomography together with both first-principles and thermodynamic calculations. Our results provide the compelling evidence for two interesting but complex group precipitation pathways of nanoparticles, i.e., the Cu-rich and NiAl-based precipitations. The co-existence of the two precipitation pathways plays a key role in age hardening kinetics and ultimately enhances the hardening response, as compared to the single particle type of strengthening, therefore providing an effective new approach for strengthening materials for structural applications.

  2. Group precipitation and age hardening of nanostructured Fe-based alloys with ultra-high strengths

    PubMed Central

    Jiao, Z. B.; Luan, J. H.; Miller, M. K.; Yu, C. Y.; Liu, C. T.

    2016-01-01

    The precipitation of nanoparticles plays a key role in determining the properties of many structural materials, and the understanding of their formation and stabilization mechanisms has been a long standing interest in the material field. However, the critical issues involving the group precipitation of various nanoparticles and their cooperative hardening mechanism remain elusive in the newly discovered Fe-based alloys with nanostructures. Here we quantitatively elucidate the nucleation mechanism, evolution kinetics and hardening effects of the group-precipitated nanoparticles in the Fe-Cu-Ni-Al-based alloys by atom probe tomography together with both first-principles and thermodynamic calculations. Our results provide the compelling evidence for two interesting but complex group precipitation pathways of nanoparticles, i.e., the Cu-rich and NiAl-based precipitations. The co-existence of the two precipitation pathways plays a key role in age hardening kinetics and ultimately enhances the hardening response, as compared to the single particle type of strengthening, therefore providing an effective new approach for strengthening materials for structural applications. PMID:26892834

  3. Nanoparticle-based signal generation and amplification in microfluidic devices for bioanalysis.

    PubMed

    Hu, Chong; Yue, Wanqing; Yang, Mengsu

    2013-11-21

    Signal generation and amplification based on nanomaterials and microfluidic techniques have both attracted considerable attention separately due to the demands for ultrasensitive and high-throughput detection of biomolecules. This article reviews the latest development of signal amplification strategies based on nanoparticles for bioanalysis and their integration and applications in microfluidic systems. The applications of nanoparticles in bioanalysis were categorized based on the different approaches of signal amplification, and the microfluidic techniques were summarized based on cell analysis and biomolecule detection with a focus on the integration of nanoparticle-based amplification in microfluidic devices for ultrasensitive bioanalysis. The advantages and limitations of the combination of nanoparticles-based amplification with microfluidic techniques were evaluated, and the possible developments for future research were discussed.

  4. Effect of Reinforcement Using Stainless Steel Mesh, Glass Fibers, and Polyethylene on the Impact Strength of Heat Cure Denture Base Resin - An In Vitro Study

    PubMed Central

    Murthy, H B Mallikarjuna; Shaik, Sharaz; Sachdeva, Harleen; Khare, Sumit; Haralur, Satheesh B; Roopa, K T

    2015-01-01

    Background: The impact strength of denture base resin is of great concern and many approaches have been made to strengthen acrylic resin dentures. The objective of this study was to compare the impact strength of the denture base resin with and without reinforcement and to evaluate the impact strength of denture base resin when reinforced with stainless steel mesh, glass fiber, and polyethylene fibers in the woven form. Materials and Methods: The specimens (maxillary denture bases) were fabricated using a standard polyvinylsiloxane mold with conventional heat cured polymethyl methacrylate resin. The specimens were divided into four groups (n = 10). Group I specimens or control group were not reinforced. Group II specimens were reinforced with stainless steel mesh and Group III and Group IV specimens were reinforced with three percent by weight of glass fibers and polyethylene fibers in weave form respectively. All the specimens were immersed in water for 1-week before testing. The impact strength was measured with falling weight impact testing machine. One-way analysis of variance and Tukey’s post-hoc test were used for statistical analysis. Results: Highest impact strength values were exhibited by the specimens reinforced with polyethylene fibers followed by glass fibers, stainless steel mesh, and control group. Conclusions: Reinforcement of maxillary complete dentures showed a significant increase in impact strength when compared to unreinforced dentures. Polyethylene fibers exhibit better impact strength followed by glass fibers and stainless steel mesh. By using pre-impregnated glass and polyethylene fibers in woven form (prepregs) the impact strength of the denture bases can be increased effectively. PMID:26124604

  5. Model-Based Information Extraction From Synthetic Aperture Radar Signals

    NASA Astrophysics Data System (ADS)

    Matzner, Shari A.

    2011-07-01

    Synthetic aperture radar (SAR) is a remote sensing technology for imaging areas of the earth's surface. SAR has been successfully used for monitoring characteristics of the natural environment such as land cover type and tree density. With the advent of higher resolution sensors, it is now theoretically possible to extract information about individual structures such as buildings from SAR imagery. This information could be used for disaster response and security-related intelligence. SAR has an advantage over other remote sensing technologies for these applications because SAR data can be collected during the night and in rainy or cloudy conditions. This research presents a model-based method for extracting information about a building -- its height and roof slope -- from a single SAR image. Other methods require multiple images or ancillary data from specialized sensors, making them less practical. The model-based method uses simulation to match a hypothesized building to an observed SAR image. The degree to which a simulation matches the observed data is measured by mutual information. The success of this method depends on the accuracy of the simulation and on the reliability of the mutual information similarity measure. Electromagnetic theory was applied to relate a building's physical characteristics to the features present in a SAR image. This understanding was used to quantify the precision of building information contained in SAR data, and to identify the inputs needed for accurate simulation. A new SAR simulation technique was developed to meet the accuracy and efficiency requirements of model-based information extraction. Mutual information, a concept from information theory, has become a standard for measuring the similarity between medical images. Its performance in the context of matching a simulation image to a SAR image was evaluated in this research, and it was found to perform well under certain conditions. The factors that affect its performance

  6. Increasing the number of African American PhDs in the sciences and engineering: a strengths-based approach.

    PubMed

    Maton, Kenneth I; Hrabowski, Freeman A

    2004-09-01

    Fifty years after Brown v. Board of Education, the percentage of African American students who receive PhDs in natural science, technology, engineering, or mathematics (STEM) fields remains disappointingly low. A multifaceted, strengths-based approach to intervention and research that holds great promise for increasing the number of African American students who achieve at the highest levels academically is described. This work began in 1988 with the development of the Meyerhoff Scholars Program for undergraduate minority STEM majors at the University of Maryland, Baltimore County (UMBC). If current PhD receipt rates of program graduates continue, UMBC will in all likelihood become the leading predominantly White baccalaureate-origin university for Black STEM PhDs in the nation. The program is described and outcome and process findings from its ongoing evaluation are highlighted. The parenting practices that helped these youths to overcome the odds and achieve at the highest levels prior to coming to college are also examined.

  7. High strength paper production based on esterification of thermomechanical pulp fibers in the presence of poly(vinyl alcohol).

    PubMed

    Awada, Houssein; Bouatmane, Mohamed; Daneault, Claude

    2015-11-01

    Thermomechanical pulp (TMP) fibers, generally used to produce newspapers and carton materials, have poor inter- and intra-fiber bonding contributing to low strength properties. Poly(vinyl alcohol) (PVOH) was applied as a co-additive of 1,2,3,4-butanetetracarboxylic acid (BTCA), in the presence of sodium hypophosphite (SHP) as a catalyst, to esterify paper sheets based on TMP fibers. Fourier transform infrared (FTIR) spectroscopy technique was used to confirm the formation of the ester bond. The effects of curing temperature, molar mass and mass amount of the PVOH on the tensile index were investigated. The increasing of the curing temperature improved further the wet tensile index. The presence of PVOH increased both the dry and the wet tensile index of the paper sheets. The rise of both the molar mass and the mass amount of PVOH improved the tensile index. PMID:27441224

  8. Improved reset breakdown strength in a HfOx-based resistive memory by introducing RuOx oxygen diffusion barrier

    NASA Astrophysics Data System (ADS)

    Park, Jaesung; Woo, Jiyong; Prakash, Amit; Lee, Sangheon; Lim, Seokjae; Hwang, Hyunsang

    2016-05-01

    We investigated the reset breakdown phenomenon of HfOx-based resistive memory for reliable switching operation in a fully CMOS compatible stack. Through the understanding on the effect of electrode materials and device area, our findings show that observed failure is attributed to additional oxygen vacancies close to the electrode interface, where switching is occurred. Therefore, RuOx serving as an oxygen diffusion barrier was introduced to suppress the generation of unwanted oxygen vacancies by preventing out-diffusion of oxygen through the electrode. As a result, significantly enhanced breakdown strength in HfOx/RuOx stack is achieved and resulting in improved cycle endurance with larger on/off ratio.

  9. Base Rates of Social Skills Acquisition/Performance Deficits, Strengths, and Problem Behaviors: An Analysis of the Social Skills Improvement System-Rating Scales

    ERIC Educational Resources Information Center

    Gresham, Frank M.; Elliott, Stephen N.; Kettler, Ryan J.

    2010-01-01

    Base rate information is important in clinical assessment because one cannot know how unusual or typical a phenomenon is without first knowing its base rate in the population. This study empirically determined the base rates of social skills acquisition and performance deficits, social skills strengths, and problem behaviors using a nationally…

  10. Development of an Acoustic Signal Analysis Tool “Auto-F” Based on the Temperament Scale

    NASA Astrophysics Data System (ADS)

    Modegi, Toshio

    The MIDI interface is originally designed for electronic musical instruments but we consider this music-note based coding concept can be extended for general acoustic signal description. We proposed applying the MIDI technology to coding of bio-medical auscultation sound signals such as heart sounds for retrieving medical records and performing telemedicine. Then we have tried to extend our encoding targets including vocal sounds, natural sounds and electronic bio-signals such as ECG, using Generalized Harmonic Analysis method. Currently, we are trying to separate vocal sounds included in popular songs and encode both vocal sounds and background instrumental sounds into separate MIDI channels. And also, we are trying to extract articulation parameters such as MIDI pitch-bend parameters in order to reproduce natural acoustic sounds using a GM-standard MIDI tone generator. In this paper, we present an overall algorithm of our developed acoustic signal analysis tool, based on those research works, which can analyze given time-based signals on the musical temperament scale. The prominent feature of this tool is producing high-precision MIDI codes, which reproduce the similar signals as the given source signal using a GM-standard MIDI tone generator, and also providing analyzed texts in the XML format.

  11. Physiological Sensor Signals Classification for Healthcare Using Sensor Data Fusion and Case-Based Reasoning

    PubMed Central

    Begum, Shahina; Barua, Shaibal; Ahmed, Mobyen Uddin

    2014-01-01

    Today, clinicians often do diagnosis and classification of diseases based on information collected from several physiological sensor signals. However, sensor signal could easily be vulnerable to uncertain noises or interferences and due to large individual variations sensitivity to different physiological sensors could also vary. Therefore, multiple sensor signal fusion is valuable to provide more robust and reliable decision. This paper demonstrates a physiological sensor signal classification approach using sensor signal fusion and case-based reasoning. The proposed approach has been evaluated to classify Stressed or Relaxed individuals using sensor data fusion. Physiological sensor signals i.e., Heart Rate (HR), Finger Temperature (FT), Respiration Rate (RR), Carbon dioxide (CO2) and Oxygen Saturation (SpO2) are collected during the data collection phase. Here, sensor fusion has been done in two different ways: (i) decision-level fusion using features extracted through traditional approaches; and (ii) data-level fusion using features extracted by means of Multivariate Multiscale Entropy (MMSE). Case-Based Reasoning (CBR) is applied for the classification of the signals. The experimental result shows that the proposed system could classify Stressed or Relaxed individual 87.5% accurately compare to an expert in the domain. So, it shows promising result in the psychophysiological domain and could be possible to adapt this approach to other relevant healthcare systems. PMID:24995374

  12. Polarization beam splitters, converters and analyzers based on a metasurface composed of regularly arranged silicon nanospheres with controllable coupling strength.

    PubMed

    Xiang, Jin; Li, Jinxiang; Li, Hui; Zhang, Chengyun; Dai, Qiaofeng; Tie, Shaolong; Lan, Sheng

    2016-05-30

    A metasurface composed of regularly arranged silicon (Si) nanospheres (NSs) with coupling was investigated both theoretically and numerically based on the Mie theory, the simple Lorentz line shape model and the finite-difference time-domain technique. By deliberately controlling the coupling strength between Si NSs through the design of the lattice constants of a rectangular lattice, polarization beam splitters, converters and analyzers with good performance can be successfully constructed. A square lattice as well as a large incidence angle was employed to build the polarization beam splitters and converters. At an incidence angle of 80°, the polarization beam splitters can completely reflect the s-polarized light and transmit the p-polarized light in a wavelength region of 510-620 nm. For a circularly polarized light incident on the polarization converters, one can get s-polarized light in the reflection direction and p-polarized light in the transmission direction. For the polarization beam analyzers, a rectangular lattice with deliberately chosen lattice constants was employed and the transmissivity of a linearly polarized light can be continuously adjusted from 0 to ~0.90 by simply rotating the metasurface. We revealed that the broadening of either the electric dipole resonance or the magnetic dipole resonance or both of them, which is induced by the asymmetric coupling of Si NSs, is responsible for the modification in the transmissivity spectrum of the metasurface. Our findings provide a guideline for designing photonic devices based on the metasurfaces composed of Si NSs with controllable coupling strength. PMID:27410070

  13. Peel bond strength of resilient liner modified by the addition of antimicrobial agents to denture base acrylic resin

    PubMed Central

    ALCÂNTARA, Cristiane S.; de MACÊDO, Allana F.C.; GURGEL, Bruno C.V.; JORGE, Janaina H.; NEPPELENBROEK, Karin H.; URBAN, Vanessa M.

    2012-01-01

    In order to prolong the clinical longevity of resilient denture relining materials and reduce plaque accumulation, incorporation of antimicrobial agents into these materials has been proposed. However, this addition may affect their properties. Objective This study evaluated the effect of the addition of antimicrobial agents into one soft liner (Soft Confort, Dencril) on its peel bond strength to one denture base (QC 20, Dentsply). Material and Methods Acrylic specimens (n=9) were made (75x10x3 mm) and stored in distilled water at 37ºC for 48 h. The drug powder concentrations (nystatin 500,000U - G2; nystatin 1,000,000U - G3; miconazole 125 mg - G4; miconazole 250 mg - G5; ketoconazole 100 mg - G6; ketoconazole 200 mg - G7; chlorhexidine diacetate 5% - G8; and 10% chlorhexidine diacetate - G9) were blended with the soft liner powder before the addition of the soft liner liquid. A group (G1) without any drug incorporation was used as control. Specimens (n=9) (75x10x6 mm) were plasticized according to the manufacturers' instructions and stored in distilled water at 37ºC for 24 h. Relined specimens were then submitted to a 180-degree peel test at a crosshead speed of 10 mm/min. Data (MPa) were analyzed by analysis of variance (α=0.05) and the failure modes were visually classified. Results No significant difference was found among experimental groups (p=0.148). Cohesive failure located within the resilient material was predominantly observed in all tested groups. Conclusions Peel bond strength between the denture base and the modified soft liner was not affected by the addition of antimicrobial agents. PMID:23329241

  14. Why does lag affect the durability of memory-based automaticity: loss of memory strength or interference?

    PubMed

    Wilkins, Nicolas J; Rawson, Katherine A

    2013-10-01

    In Rickard, Lau, and Pashler's (2008) investigation of the lag effect on memory-based automaticity, response times were faster and proportion of trials retrieved was higher at the end of practice for short lag items than for long lag items. However, during testing after a delay, response times were slower and proportion of trials retrieved was lower for short lag items than for long lag items. The current study investigated the extent to which the lag effect on the durability of memory-based automaticity is due to interference or to the loss of memory strength with time. Participants repeatedly practiced alphabet subtraction items in short lag and long lag conditions. After practice, half of the participants were immediately tested and the other half were tested after a 7-day delay. Results indicate that the lag effect on the durability of memory-based automaticity is primarily due to interference. We discuss potential modification of current memory-based processing theories to account for these effects. PMID:24012722

  15. [Research Progress of Automatic Sleep Staging Based on Electroencephalogram Signals].

    PubMed

    Gao, Qunxia; Zhou, Jing; Wu, Xiaoming

    2015-10-01

    The research of sleep staging is not only a basis of diagnosing sleep related diseases but also the precondition of evaluating sleep quality, and has important clinical significance. In recent years, the research of automatic sleep staging based on computer has become a hot spot and got some achievements. The basic knowledge of sleep staging and electroencephalogram (EEG) is introduced in this paper. Then, feature extraction and pattern recognition, two key technologies for automatic sleep staging, are discussed in detail. Wavelet transform and Hilbert-Huang transform, two methods for feature extraction, are compared. Artificial neural network and support vector machine (SVM), two methods for pattern recognition are discussed. In the end, the research status of this field is summarized, and development trends of next phase are pointed out. PMID:26964329

  16. PageRank-based identification of signaling crosstalk from transcriptomics data: the case of Arabidopsis thaliana.

    PubMed

    Omranian, Nooshin; Mueller-Roeber, Bernd; Nikoloski, Zoran

    2012-04-01

    The levels of cellular organization, from gene transcription to translation to protein-protein interaction and metabolism, operate via tightly regulated mutual interactions, facilitating organismal adaptability and various stress responses. Characterizing the mutual interactions between genes, transcription factors, and proteins involved in signaling, termed crosstalk, is therefore crucial for understanding and controlling cells' functionality. We aim at using high-throughput transcriptomics data to discover previously unknown links between signaling networks. We propose and analyze a novel method for crosstalk identification which relies on transcriptomics data and overcomes the lack of complete information for signaling pathways in Arabidopsis thaliana. Our method first employs a network-based transformation of the results from the statistical analysis of differential gene expression in given groups of experiments under different signal-inducing conditions. The stationary distribution of a random walk (similar to the PageRank algorithm) on the constructed network is then used to determine the putative transcripts interrelating different signaling pathways. With the help of the proposed method, we analyze a transcriptomics data set including experiments from four different stresses/signals: nitrate, sulfur, iron, and hormones. We identified promising gene candidates, downstream of the transcription factors (TFs), associated to signaling crosstalk, which were validated through literature mining. In addition, we conduct a comparative analysis with the only other available method in this field which used a biclustering-based approach. Surprisingly, the biclustering-based approach fails to robustly identify any candidate genes involved in the crosstalk of the analyzed signals. We demonstrate that our proposed method is more robust in identifying gene candidates involved downstream of the signaling crosstalk for species for which large transcriptomics data sets

  17. Strength nutrition.

    PubMed

    Volek, Jeff S

    2003-08-01

    Muscle strength is determined by muscle size and factors related to neural recruitment. Resistance training is a potent stimulus for increasing muscle size and strength. These increases are, to a large extent, influenced and mediated by changes in hormones that regulate important events during the recovery process following exercise. Provision of nutrients in the appropriate amounts and at the appropriate times is necessary to optimize the recovery process. This review discusses the results of research that has examined the potential for nutrition and dietary supplements to impact the acute response to resistance exercise and chronic adaptations to resistance training. To date, the most promising strategies to augment gains in muscle size and strength appear to be consumption of protein-carbohydrate calories before and after resistance exercise, and creatine supplementation.

  18. Parameter-induced stochastic resonance based on spectral entropy and its application to weak signal detection.

    PubMed

    Zhang, Jinjing; Zhang, Tao

    2015-02-01

    The parameter-induced stochastic resonance based on spectral entropy (PSRSE) method is introduced for the detection of a very weak signal in the presence of strong noise. The effect of stochastic resonance on the detection is optimized using parameters obtained in spectral entropy analysis. Upon processing employing the PSRSE method, the amplitude of the weak signal is enhanced and the noise power is reduced, so that the frequency of the signal can be estimated with greater precision through spectral analysis. While the improvement in the signal-to-noise ratio is similar to that obtained using the Duffing oscillator algorithm, the computational cost reduces from O(N(2)) to O(N). The PSRSE approach is applied to the frequency measurement of a weak signal made by a vortex flow meter. The results are compared with those obtained applying the Duffing oscillator algorithm. PMID:25725879

  19. Parameter-induced stochastic resonance based on spectral entropy and its application to weak signal detection

    SciTech Connect

    Zhang, Jinjing; Zhang, Tao

    2015-02-15

    The parameter-induced stochastic resonance based on spectral entropy (PSRSE) method is introduced for the detection of a very weak signal in the presence of strong noise. The effect of stochastic resonance on the detection is optimized using parameters obtained in spectral entropy analysis. Upon processing employing the PSRSE method, the amplitude of the weak signal is enhanced and the noise power is reduced, so that the frequency of the signal can be estimated with greater precision through spectral analysis. While the improvement in the signal-to-noise ratio is similar to that obtained using the Duffing oscillator algorithm, the computational cost reduces from O(N{sup 2}) to O(N). The PSRSE approach is applied to the frequency measurement of a weak signal made by a vortex flow meter. The results are compared with those obtained applying the Duffing oscillator algorithm.

  20. On-chip microwave signal generation based on a silicon microring modulator.

    PubMed

    Shao, Haifeng; Yu, Hui; Li, Xia; Li, Yan; Jiang, Jianfei; Wei, Huan; Wang, Gencheng; Dai, Tingge; Chen, Qimei; Yang, Jianyi; Jiang, Xiaoqing

    2015-07-15

    A photonic-assisted microwave signal generator based on a silicon microring modulator is demonstrated. The microring cavity incorporates an embedded PN junction that enables a microwave signal to modulate the lightwave circling inside. The DC component of the modulated light is trapped in the cavity, while the high-order sideband components are able to exit the cavity and then generate microwave signals at new frequencies in a photodetector. In our proof-of-concept experiment, a 10 GHz microwave signal is converted to a 20 GHz signal in the optical domain with an electrical harmonic suppression ratio of 22 dB. An analytic model is also established to explain the operation mechanism, which agrees well with the measured data.