Vibro-Acoustic Modulation Based Damage Identification in a Composite Skin-Stiffener Structure

NASA Technical Reports Server (NTRS)

Ooijevaar, T. H.; Loendersloot, R.; Rogge, M. D.; Akkerman, R.; Tinga, T.

2014-01-01

The vibro-acoustic modulation method is applied to a composite skin-stiffener structure to investigate the possibilities to utilize this method for damage identification in terms of detection, localisation and damage quantification. The research comprises a theoretical part and an experimental part. An impact load is applied to the skin-stiffener structure, resulting in a delamination underneath the stiffener. The structure is interrogated with a low frequency pump excitation and a high frequency carrier excitation. The analysis of the response in a frequency band around the carrier frequency is employed to assess the damage identification capabilities and to gain a better understanding of the modulations occurring and the underlying physical phenomena. Though vibro-acoustic is shown to be a sensitive method for damage identification, the complexity of the damage, combined with a high modal density, complicate the understanding of the relation between the physical phenomena and the modulations occurring. more research is recommended to reveal the physics behind the observations.

Structural damage detection based on stochastic subspace identification and statistical pattern recognition: II. Experimental validation under varying temperature

NASA Astrophysics Data System (ADS)

Lin, Y. Q.; Ren, W. X.; Fang, S. E.

2011-11-01

Although most vibration-based damage detection methods can acquire satisfactory verification on analytical or numerical structures, most of them may encounter problems when applied to real-world structures under varying environments. The damage detection methods that directly extract damage features from the periodically sampled dynamic time history response measurements are desirable but relevant research and field application verification are still lacking. In this second part of a two-part paper, the robustness and performance of the statistics-based damage index using the forward innovation model by stochastic subspace identification of a vibrating structure proposed in the first part have been investigated against two prestressed reinforced concrete (RC) beams tested in the laboratory and a full-scale RC arch bridge tested in the field under varying environments. Experimental verification is focused on temperature effects. It is demonstrated that the proposed statistics-based damage index is insensitive to temperature variations but sensitive to the structural deterioration or state alteration. This makes it possible to detect the structural damage for the real-scale structures experiencing ambient excitations and varying environmental conditions.

Nonlinear damage identification of breathing cracks in Truss system

NASA Astrophysics Data System (ADS)

Zhao, Jie; DeSmidt, Hans

2014-03-01

The breathing cracks in truss system are detected by Frequency Response Function (FRF) based damage identification method. This method utilizes damage-induced changes of frequency response functions to estimate the severity and location of structural damage. This approach enables the possibility of arbitrary interrogation frequency and multiple inputs/outputs which greatly enrich the dataset for damage identification. The dynamical model of truss system is built using the finite element method and the crack model is based on fracture mechanics. Since the crack is driven by tensional and compressive forces of truss member, only one damage parameter is needed to represent the stiffness reduction of each truss member. Assuming that the crack constantly breathes with the exciting frequency, the linear damage detection algorithm is developed in frequency/time domain using Least Square and Newton Raphson methods. Then, the dynamic response of the truss system with breathing cracks is simulated in the time domain and meanwhile the crack breathing status for each member is determined by the feedback from real-time displacements of member's nodes. Harmonic Fourier Coefficients (HFCs) of dynamical response are computed by processing the data through convolution and moving average filters. Finally, the results show the effectiveness of linear damage detection algorithm in identifying the nonlinear breathing cracks using different combinations of HFCs and sensors.

A novel damage index for damage identification using guided waves with application in laminated composites

NASA Astrophysics Data System (ADS)

Torkamani, Shahab; Roy, Samit; Barkey, Mark E.; Sazonov, Edward; Burkett, Susan; Kotru, Sushma

2014-09-01

In the current investigation, an innovative time-domain damage index is introduced for the first time which is based on local statistical features of the waveform. This damage index is called the ‘normalized correlation moment’ (NCM) and is composed of the nth moment of the cross-correlation of the baseline and comparison waves. The performance of this novel damage index is compared for some synthetic signals with that of an existing damage index based on the Pearson correlation coefficient (signal difference coefficient, SDC). The proposed damage index is shown to have significant advantages over the SDC, including sensitivity to the attenuation of the signal and lower sensitivity to the signal’s noise level. Numerical simulations using Abaqus finite element (FE) software show that this novel damage index is not only capable of detecting the delamination type of damage, but also exhibits a good ability in the assessment of this type of damage in laminated composite structures. The NCM damage index is also validated using experimental data for identification of delamination in composites.

An AI-based approach to structural damage identification by modal analysis

NASA Technical Reports Server (NTRS)

Glass, B. J.; Hanagud, S.

1990-01-01

Flexible-structure damage is presently addressed by a combined model- and parameter-identification approach which employs the AI methodologies of classification, heuristic search, and object-oriented model knowledge representation. The conditions for model-space search convergence to the best model are discussed in terms of search-tree organization and initial model parameter error. In the illustrative example of a truss structure presented, the use of both model and parameter identification is shown to lead to smaller parameter corrections than would be required by parameter identification alone.

Time domain nonlinear SMA damper force identification approach and its numerical validation

NASA Astrophysics Data System (ADS)

Xin, Lulu; Xu, Bin; He, Jia

2012-04-01

Most of the currently available vibration-based identification approaches for structural damage detection are based on eigenvalues and/or eigenvectors extracted from vibration measurements and, strictly speaking, are only suitable for linear system. However, the initiation and development of damage in engineering structures under severe dynamic loadings are typical nonlinear procedure. Studies on the identification of restoring force which is a direct indicator of the extent of the nonlinearity have received increasing attention in recent years. In this study, a date-based time domain identification approach for general nonlinear system was developed. The applied excitation and the corresponding response time series of the structure were used for identification by means of standard least-square techniques and a power series polynomial model (PSPM) which was utilized to model the nonlinear restoring force (NRF). The feasibility and robustness of the proposed approach was verified by a 2 degree-of-freedoms (DOFs) lumped mass numerical model equipped with a shape memory ally (SMA) damper mimicking nonlinear behavior. The results show that the proposed data-based time domain method is capable of identifying the NRF in engineering structures without any assumptions on the mass distribution and the topology of the structure, and provides a promising way for damage detection in the presence of structural nonlinearities.

Structural damage detection based on stochastic subspace identification and statistical pattern recognition: I. Theory

NASA Astrophysics Data System (ADS)

Ren, W. X.; Lin, Y. Q.; Fang, S. E.

2011-11-01

One of the key issues in vibration-based structural health monitoring is to extract the damage-sensitive but environment-insensitive features from sampled dynamic response measurements and to carry out the statistical analysis of these features for structural damage detection. A new damage feature is proposed in this paper by using the system matrices of the forward innovation model based on the covariance-driven stochastic subspace identification of a vibrating system. To overcome the variations of the system matrices, a non-singularity transposition matrix is introduced so that the system matrices are normalized to their standard forms. For reducing the effects of modeling errors, noise and environmental variations on measured structural responses, a statistical pattern recognition paradigm is incorporated into the proposed method. The Mahalanobis and Euclidean distance decision functions of the damage feature vector are adopted by defining a statistics-based damage index. The proposed structural damage detection method is verified against one numerical signal and two numerical beams. It is demonstrated that the proposed statistics-based damage index is sensitive to damage and shows some robustness to the noise and false estimation of the system ranks. The method is capable of locating damage of the beam structures under different types of excitations. The robustness of the proposed damage detection method to the variations in environmental temperature is further validated in a companion paper by a reinforced concrete beam tested in the laboratory and a full-scale arch bridge tested in the field.

Knowledge of damage identification about tensegrities via flexibility disassembly

NASA Astrophysics Data System (ADS)

Jiang, Ge; Feng, Xiaodong; Du, Shigui

2017-12-01

Tensegrity structures composing of continuous cables and discrete struts are under tension and compression, respectively. In order to determine the damage extents of tensegrity structures, a new method for tensegrity structural damage identification is presented based on flexibility disassembly. To decompose a tensegrity structural flexibility matrix into the matrix represention of the connectivity between degress-of-freedoms and the diagonal matrix comprising of magnitude informations. Step 1: Calculate perturbation flexibility; Step 2: Compute the flexibility connectivity matrix and perturbation flexibility parameters; Step 3: Calculate the perturbation stiffness parameters. The efficiency of the proposed method is demonstrated by a numeical example comprising of 12 cables and 4 struts with pretensioned. Accurate identification of local damage depends on the availability of good measured data, an accurate and reasonable algorithm.

Identification and calibration of the structural model of historical masonry building damaged during the 2016 Italian earthquakes: The case study of Palazzo del Podestà in Montelupone

NASA Astrophysics Data System (ADS)

Catinari, Federico; Pierdicca, Alessio; Clementi, Francesco; Lenci, Stefano

2017-11-01

The results of an ambient-vibration based investigation conducted on the "Palazzo del Podesta" in Montelupone (Italy) is presented. The case study was damaged during the 20I6 Italian earthquakes that stroke the central part of the Italy. The assessment procedure includes full-scale ambient vibration testing, modal identification from ambient vibration responses, finite element modeling and dynamic-based identification of the uncertain structural parameters of the model. A very good match between theoretical and experimental modal parameters was reached and the model updating has been performed identifying some structural parameters.

Text block identification in restoration process of Javanese script damage

NASA Astrophysics Data System (ADS)

Himamunanto, A. R.; Setyowati, E.

2018-05-01

Generally, in a sheet of documents there are two objects of information, namely text and image. A text block area in the sheet of manuscript is a vital object because the restoration process would be done only in this object. Text block or text area identification becomes an important step before. This paper describes the steps leading to the restoration of Java script destruction. The process stages are: pre-processing, identification of text block, segmentation, damage identification, restoration. The test result based on the input manuscript “Hamong Tani” show that the system works with a success rate of 82.07%

Research on Damage Identification of Bridge Based on Digital Image Measurement

NASA Astrophysics Data System (ADS)

Liang, Yingjing; Huan, Shi; Tao, Weijun

2017-12-01

In recent years, the number of the damage bridge due to excessive deformation gradually increased, which caused significant property damage and casualties. Hence health monitoring and the damage detection of the bridge structure based on the deflection measurement are particularly important. The current conventional deflection measurement methods, such as total station, connected pipe, GPS, etc., have many shortcomings as low efficiency, heavy workload, low degree of automation, operating frequency and working time constrained. GPS has a low accuracy in the vertical displacement measurement and cannot meet the dynamic measured requirements of the current bridge engineering. This paper presents a bridge health monitoring and damage detection technology based on digital image measurement method in which the measurement accuracy is sub-millimeter level and can achieve the 24-hour automatic non-destructive monitoring for the deflection. It can be concluded from this paper that it is feasible to use digital image measurement method for identification of the damage in the bridge structure, because it has been validated by the theoretical analysis, the laboratory model and the application of the real bridge.

Damage detection and quantification in a structural model under seismic excitation using time-frequency analysis

NASA Astrophysics Data System (ADS)

Chan, Chun-Kai; Loh, Chin-Hsiung; Wu, Tzu-Hsiu

2015-04-01

In civil engineering, health monitoring and damage detection are typically carry out by using a large amount of sensors. Typically, most methods require global measurements to extract the properties of the structure. However, some sensors, like LVDT, cannot be used due to in situ limitation so that the global deformation remains unknown. An experiment is used to demonstrate the proposed algorithms: a one-story 2-bay reinforce concrete frame under weak and strong seismic excitation. In this paper signal processing techniques and nonlinear identification are used and applied to the response measurements of seismic response of reinforced concrete structures subject to different level of earthquake excitations. Both modal-based and signal-based system identification and feature extraction techniques are used to study the nonlinear inelastic response of RC frame using both input and output response data or output only measurement. From the signal-based damage identification method, which include the enhancement of time-frequency analysis of acceleration responses and the estimation of permanent deformation using directly from acceleration response data. Finally, local deformation measurement from dense optical tractor is also use to quantify the damage of the RC frame structure.

Identification of sandstone core damage using scanning electron microscopy

NASA Astrophysics Data System (ADS)

Ismail, Abdul Razak; Jaafar, Mohd Zaidi; Sulaiman, Wan Rosli Wan; Ismail, Issham; Shiunn, Ng Yinn

2017-12-01

Particles and fluids invasion into the pore spaces causes serious damage to the formation, resulting reduction in petroleum production. In order to prevent permeability damage for a well effectively, the damage mechanisms should be identified. In this study, water-based drilling fluid was compared to oil-based drilling fluids based on microscopic observation. The cores were damaged by several drilling fluid systems. Scanning electron microscope (SEM) was used to observe the damage mechanism caused by the drilling fluids. Results showed that the ester based drilling fluid system caused the most serious damage followed by synthetic oil based system and KCI-polymer system. Fine solids and filtrate migration and emulsion blockage are believed to be the major mechanisms controlling the changes in flow properties for the sandstone samples.

Identification of Bearing Failure Using Signal Vibrations

NASA Astrophysics Data System (ADS)

Yani, Irsyadi; Resti, Yulia; Burlian, Firmansyah

2018-04-01

Vibration analysis can be used to identify damage to mechanical systems such as journal bearings. Identification of failure can be done by observing the resulting vibration spectrum by measuring the vibration signal occurring in a mechanical system Bearing is one of the engine elements commonly used in mechanical systems. The main purpose of this research is to monitor the bearing condition and to identify bearing failure on a mechanical system by observing the resulting vibration. Data collection techniques based on recordings of sound caused by the vibration of the mechanical system were used in this study, then created a database system based bearing failure due to vibration signal recording sounds on a mechanical system The next step is to group the bearing damage by type based on the databases obtained. The results show the percentage of success in identifying bearing damage is 98 %.

Vibration based structural health monitoring of an arch bridge: From automated OMA to damage detection

NASA Astrophysics Data System (ADS)

Magalhães, F.; Cunha, A.; Caetano, E.

2012-04-01

In order to evaluate the usefulness of approaches based on modal parameters tracking for structural health monitoring of bridges, in September of 2007, a dynamic monitoring system was installed in a concrete arch bridge at the city of Porto, in Portugal. The implementation of algorithms to perform the continuous on-line identification of modal parameters based on structural responses to ambient excitation (automated Operational Modal Analysis) has permitted to create a very complete database with the time evolution of the bridge modal characteristics during more than 2 years. This paper describes the strategy that was followed to minimize the effects of environmental and operational factors on the bridge natural frequencies, enabling, in a subsequent stage, the identification of structural anomalies. Alternative static and dynamic regression models are tested and complemented by a Principal Components Analysis. Afterwards, the identification of damages is tried with control charts. At the end, it is demonstrated that the adopted processing methodology permits the detection of realistic damage scenarios, associated with frequency shifts around 0.2%, which were simulated with a numerical model.

Detection of Non-Symmetrical Damage in Smart Plate-Like Structures

NASA Technical Reports Server (NTRS)

Blanks, H. T.; Emeric, P. R.

1998-01-01

A two-dimensional model for in-plane vibrations of a cantilever plate with a non-symmetrical damage is used in the context of defect identification in materials with piezoelectric ceramic patches bonded to their surface. These patches can act both as actuators and sensors in a self-analyzing fashion, which is a characteristic of smart materials. A Galerkin method is used to approximate the dynamic response of these structures. The natural frequency shifts due to the damage are estimated numerically and compared to experimental data obtained from tests on cantilever aluminum plate-like structures damaged at different locations with defects of different depths. The damage location and extent are determined by an enhanced least square identification method. Efficacy of the frequency shift based algorithms is demonstrated using experimental data.

On-the-spot damage detection methodology for highway bridges.

DOT National Transportation Integrated Search

2010-07-01

Vibration-based damage identification (VBDI) techniques have been developed in part to address the problems associated with an aging civil infrastructure. To assess the potential of VBDI as it applies to highway bridges in Iowa, three applications of...

Seismic damage identification for steel structures using distributed fiber optics.

PubMed

Hou, Shuang; Cai, C S; Ou, Jinping

2009-08-01

A distributed fiber optic monitoring methodology based on optic time domain reflectometry technology is developed for seismic damage identification of steel structures. Epoxy with a strength closely associated to a specified structure damage state is used for bonding zigzagged configured optic fibers on the surfaces of the structure. Sensing the local deformation of the structure, the epoxy modulates the signal change within the optic fiber in response to the damage state of the structure. A monotonic loading test is conducted on a steel specimen installed with the proposed sensing system using selected epoxy that will crack at the designated strain level, which indicates the damage of the steel structure. Then, using the selected epoxy, a varying degree of cyclic loading amplitudes, which is associated with different damage states, is applied on a second specimen. The test results show that the specimen's damage can be identified by the optic sensors, and its maximum local deformation can be recorded by the sensing system; moreover, the damage evolution can also be identified.

Identification of damage in composite structures using Gaussian mixture model-processed Lamb waves

NASA Astrophysics Data System (ADS)

Wang, Qiang; Ma, Shuxian; Yue, Dong

2018-04-01

Composite materials have comprehensively better properties than traditional materials, and therefore have been more and more widely used, especially because of its higher strength-weight ratio. However, the damage of composite structures is usually varied and complicated. In order to ensure the security of these structures, it is necessary to monitor and distinguish the structural damage in a timely manner. Lamb wave-based structural health monitoring (SHM) has been proved to be effective in online structural damage detection and evaluation; furthermore, the characteristic parameters of the multi-mode Lamb wave varies in response to different types of damage in the composite material. This paper studies the damage identification approach for composite structures using the Lamb wave and the Gaussian mixture model (GMM). The algorithm and principle of the GMM, and the parameter estimation, is introduced. Multi-statistical characteristic parameters of the excited Lamb waves are extracted, and the parameter space with reduced dimensions is adopted by principal component analysis (PCA). The damage identification system using the GMM is then established through training. Experiments on a glass fiber-reinforced epoxy composite laminate plate are conducted to verify the feasibility of the proposed approach in terms of damage classification. The experimental results show that different types of damage can be identified according to the value of the likelihood function of the GMM.

Construction, implementation and testing of an image identification system using computer vision methods for fruit flies with economic importance (Diptera: Tephritidae).

PubMed

Wang, Jiang-Ning; Chen, Xiao-Lin; Hou, Xin-Wen; Zhou, Li-Bing; Zhu, Chao-Dong; Ji, Li-Qiang

2017-07-01

Many species of Tephritidae are damaging to fruit, which might negatively impact international fruit trade. Automatic or semi-automatic identification of fruit flies are greatly needed for diagnosing causes of damage and quarantine protocols for economically relevant insects. A fruit fly image identification system named AFIS1.0 has been developed using 74 species belonging to six genera, which include the majority of pests in the Tephritidae. The system combines automated image identification and manual verification, balancing operability and accuracy. AFIS1.0 integrates image analysis and expert system into a content-based image retrieval framework. In the the automatic identification module, AFIS1.0 gives candidate identification results. Afterwards users can do manual selection based on comparing unidentified images with a subset of images corresponding to the automatic identification result. The system uses Gabor surface features in automated identification and yielded an overall classification success rate of 87% to the species level by Independent Multi-part Image Automatic Identification Test. The system is useful for users with or without specific expertise on Tephritidae in the task of rapid and effective identification of fruit flies. It makes the application of computer vision technology to fruit fly recognition much closer to production level. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Acoustic emission based damage localization in composites structures using Bayesian identification

NASA Astrophysics Data System (ADS)

Kundu, A.; Eaton, M. J.; Al-Jumali, S.; Sikdar, S.; Pullin, R.

2017-05-01

Acoustic emission based damage detection in composite structures is based on detection of ultra high frequency packets of acoustic waves emitted from damage sources (such as fibre breakage, fatigue fracture, amongst others) with a network of distributed sensors. This non-destructive monitoring scheme requires solving an inverse problem where the measured signals are linked back to the location of the source. This in turn enables rapid deployment of mitigative measures. The presence of significant amount of uncertainty associated with the operating conditions and measurements makes the problem of damage identification quite challenging. The uncertainties stem from the fact that the measured signals are affected by the irregular geometries, manufacturing imprecision, imperfect boundary conditions, existing damages/structural degradation, amongst others. This work aims to tackle these uncertainties within a framework of automated probabilistic damage detection. The method trains a probabilistic model of the parametrized input and output model of the acoustic emission system with experimental data to give probabilistic descriptors of damage locations. A response surface modelling the acoustic emission as a function of parametrized damage signals collected from sensors would be calibrated with a training dataset using Bayesian inference. This is used to deduce damage locations in the online monitoring phase. During online monitoring, the spatially correlated time data is utilized in conjunction with the calibrated acoustic emissions model to infer the probabilistic description of the acoustic emission source within a hierarchical Bayesian inference framework. The methodology is tested on a composite structure consisting of carbon fibre panel with stiffeners and damage source behaviour has been experimentally simulated using standard H-N sources. The methodology presented in this study would be applicable in the current form to structural damage detection under varying operational loads and would be investigated in future studies.

On the Role of Urban and Vegetative Land Cover in the Identification of Tornado Damage Using Dual-Resolution Multispectral Satellite Imagery

NASA Astrophysics Data System (ADS)

Kingfield, D.; de Beurs, K.

2014-12-01

It has been demonstrated through various case studies that multispectral satellite imagery can be utilized in the identification of damage caused by a tornado through the change detection process. This process involves the difference in returned surface reflectance between two images and is often summarized through a variety of ratio-based vegetation indices (VIs). Land cover type plays a large contributing role in the change detection process as the reflectance properties of vegetation can vary based on several factors (e.g. species, greenness, density). Consequently, this provides the possibility for a variable magnitude of loss, making certain land cover regimes less reliable in the damage identification process. Furthermore, the tradeoff between sensor resolution and orbital return period may also play a role in the ability to detect catastrophic loss. Moderate resolution imagery (e.g. Moderate Resolution Imaging Spectroradiometer (MODIS)) provides relatively coarse surface detail with a higher update rate which could hinder the identification of small regions that underwent a dynamic change. Alternatively, imagery with higher spatial resolution (e.g. Landsat) have a longer temporal return period between successive images which could result in natural recovery underestimating the absolute magnitude of damage incurred. This study evaluates the role of land cover type and sensor resolution on four high-end (EF3+) tornado events occurring in four different land cover groups (agriculture, forest, grassland, urban) in the spring season. The closest successive clear images from both Landsat 5 and MODIS are quality controlled for each case. Transacts of surface reflectance across a homogenous land cover type both inside and outside the damage swath are extracted. These metrics are synthesized through the calculation of six different VIs to rank the calculated change metrics by land cover type, sensor resolution and VI.

Frequency Response Function Based Damage Identification for Aerospace Structures

NASA Astrophysics Data System (ADS)

Oliver, Joseph Acton

Structural health monitoring technologies continue to be pursued for aerospace structures in the interests of increased safety and, when combined with health prognosis, efficiency in life-cycle management. The current dissertation develops and validates damage identification technology as a critical component for structural health monitoring of aerospace structures and, in particular, composite unmanned aerial vehicles. The primary innovation is a statistical least-squares damage identification algorithm based in concepts of parameter estimation and model update. The algorithm uses frequency response function based residual force vectors derived from distributed vibration measurements to update a structural finite element model through statistically weighted least-squares minimization producing location and quantification of the damage, estimation uncertainty, and an updated model. Advantages compared to other approaches include robust applicability to systems which are heavily damped, large, and noisy, with a relatively low number of distributed measurement points compared to the number of analytical degrees-of-freedom of an associated analytical structural model (e.g., modal finite element model). Motivation, research objectives, and a dissertation summary are discussed in Chapter 1 followed by a literature review in Chapter 2. Chapter 3 gives background theory and the damage identification algorithm derivation followed by a study of fundamental algorithm behavior on a two degree-of-freedom mass-spring system with generalized damping. Chapter 4 investigates the impact of noise then successfully proves the algorithm against competing methods using an analytical eight degree-of-freedom mass-spring system with non-proportional structural damping. Chapter 5 extends use of the algorithm to finite element models, including solutions for numerical issues, approaches for modeling damping approximately in reduced coordinates, and analytical validation using a composite sandwich plate model. Chapter 6 presents the final extension to experimental systems-including methods for initial baseline correlation and data reduction-and validates the algorithm on an experimental composite plate with impact damage. The final chapter deviates from development and validation of the primary algorithm to discuss development of an experimental scaled-wing test bed as part of a collaborative effort for developing structural health monitoring and prognosis technology. The dissertation concludes with an overview of technical conclusions and recommendations for future work.

Damage identification on spatial Timoshenko arches by means of genetic algorithms

NASA Astrophysics Data System (ADS)

Greco, A.; D'Urso, D.; Cannizzaro, F.; Pluchino, A.

2018-05-01

In this paper a procedure for the dynamic identification of damage in spatial Timoshenko arches is presented. The proposed approach is based on the calculation of an arbitrary number of exact eigen-properties of a damaged spatial arch by means of the Wittrick and Williams algorithm. The proposed damage model considers a reduction of the volume in a part of the arch, and is therefore suitable, differently than what is commonly proposed in the main part of the dedicated literature, not only for concentrated cracks but also for diffused damaged zones which may involve a loss of mass. Different damage scenarios can be taken into account with variable location, intensity and extension of the damage as well as number of damaged segments. An optimization procedure, aiming at identifying which damage configuration minimizes the difference between its eigen-properties and a set of measured modal quantities for the structure, is implemented making use of genetic algorithms. In this context, an initial random population of chromosomes, representing different damage distributions along the arch, is forced to evolve towards the fittest solution. Several applications with different, single or multiple, damaged zones and boundary conditions confirm the validity and the applicability of the proposed procedure even in presence of instrumental errors on the measured data.

UAV-based urban structural damage assessment using object-based image analysis and semantic reasoning

NASA Astrophysics Data System (ADS)

Fernandez Galarreta, J.; Kerle, N.; Gerke, M.

2015-06-01

Structural damage assessment is critical after disasters but remains a challenge. Many studies have explored the potential of remote sensing data, but limitations of vertical data persist. Oblique imagery has been identified as more useful, though the multi-angle imagery also adds a new dimension of complexity. This paper addresses damage assessment based on multi-perspective, overlapping, very high resolution oblique images obtained with unmanned aerial vehicles (UAVs). 3-D point-cloud assessment for the entire building is combined with detailed object-based image analysis (OBIA) of façades and roofs. This research focuses not on automatic damage assessment, but on creating a methodology that supports the often ambiguous classification of intermediate damage levels, aiming at producing comprehensive per-building damage scores. We identify completely damaged structures in the 3-D point cloud, and for all other cases provide the OBIA-based damage indicators to be used as auxiliary information by damage analysts. The results demonstrate the usability of the 3-D point-cloud data to identify major damage features. Also the UAV-derived and OBIA-processed oblique images are shown to be a suitable basis for the identification of detailed damage features on façades and roofs. Finally, we also demonstrate the possibility of aggregating the multi-perspective damage information at building level.

Multi-damage identification based on joint approximate diagonalisation and robust distance measure

NASA Astrophysics Data System (ADS)

Cao, S.; Ouyang, H.

2017-05-01

Mode shapes or operational deflection shapes are highly sensitive to damage and can be used for multi-damage identification. Nevertheless, one drawback of this kind of methods is that the extracted spatial shape features tend to be compromised by noise, which degrades their damage identification accuracy, especially for incipient damage. To overcome this, joint approximate diagonalisation (JAD) also known as simultaneous diagonalisation is investigated to estimate mode shapes (MS’s) statistically. The major advantage of JAD method is that it efficiently provides the common Eigen-structure of a set of power spectral density matrices. In this paper, a new criterion in terms of coefficient of variation (CV) is utilised to numerically demonstrate the better noise robustness and accuracy of JAD method over traditional frequency domain decomposition method (FDD). Another original contribution is that a new robust damage index (DI) is proposed, which is comprised of local MS distortions of several modes weighted by their associated vibration participation factors. The advantage of doing this is to include fair contributions from changes of all modes concerned. Moreover, the proposed DI provides a measure of damage-induced changes in ‘modal vibration energy’ in terms of the selected mode shapes. Finally, an experimental study is presented to verify the efficiency and noise robustness of JAD method and the proposed DI. The results show that the proposed DI is effective and robust under random vibration situations, which indicates that it has the potential to be applied to practical engineering structures with ambient excitations.

Optimum electrode configuration selection for electrical resistance change based damage detection in composites using an effective independence measure

NASA Astrophysics Data System (ADS)

Escalona, Luis; Díaz-Montiel, Paulina; Venkataraman, Satchi

2016-04-01

Laminated carbon fiber reinforced polymer (CFRP) composite materials are increasingly used in aerospace structures due to their superior mechanical properties and reduced weight. Assessing the health and integrity of these structures requires non-destructive evaluation (NDE) techniques to detect and measure interlaminar delamination and intralaminar matrix cracking damage. The electrical resistance change (ERC) based NDE technique uses the inherent changes in conductive properties of the composite to characterize internal damage. Several works that have explored the ERC technique have been limited to thin cross-ply laminates with simple linear or circular electrode arrangements. This paper investigates a method of optimum selection of electrode configurations for delamination detection in thick cross-ply laminates using ERC. Inverse identification of damage requires numerical optimization of the measured response with a model predicted response. Here, the electrical voltage field in the CFRP composite laminate is calculated using finite element analysis (FEA) models for different specified delamination size and locations, and location of ground and current electrodes. Reducing the number of sensor locations and measurements is needed to reduce hardware requirements, and computational effort needed for inverse identification. This paper explores the use of effective independence (EI) measure originally proposed for sensor location optimization in experimental vibration modal analysis. The EI measure is used for selecting the minimum set of resistance measurements among all possible combinations of selecting a pair of electrodes among the n electrodes. To enable use of EI to ERC required, it is proposed in this research a singular value decomposition SVD to obtain a spectral representation of the resistance measurements in the laminate. The effectiveness of EI measure in eliminating redundant electrode pairs is demonstrated by performing inverse identification of damage using the full set of resistance measurements and the reduced set of measurements. The investigation shows that the EI measure is effective for optimally selecting the electrode pairs needed for resistance measurements in ERC based damage detection.

Right hemisphere specialization for the identification of emotional words and sentences: evidence from stroke patients.

PubMed

Borod, J C; Andelman, F; Obler, L K; Tweedy, J R; Welkowitz, J

1992-09-01

This study examines the contribution of the lexical/verbal channel to emotional processing in 16 right brain-damaged (RBD), 16 left brain-damaged (LBD) and 16 normal control (NC) right-handed adults. Emotional lexical perception tasks were developed; analogous nonemotional tasks were created to control for cognitive and linguistic factors. The three subject groups were matched for gender, age and education. The brain-damaged groups were similar with respect to cerebrovascular etiology, months post-onset, sensory-motor status and lesion location. Parallel emotional and nonemotional tasks included word identification, sentence identification and word discrimination. For both word tasks, RBDs were significantly more impaired than LBDs and NCs in the emotional condition. For all three tasks, RBDs showed a significantly greater performance discrepancy between emotional and nonemotional conditions than did LBDs or NCs. Results were not affected by the valence (i.e. positive/negative) of the stimuli. These findings suggest a dominant role for the right hemisphere in the perception of lexically-based emotional stimuli.

Structural damage identification using piezoelectric impedance measurement with sparse inverse analysis

NASA Astrophysics Data System (ADS)

Cao, Pei; Qi, Shuai; Tang, J.

2018-03-01

The impedance/admittance measurements of a piezoelectric transducer bonded to or embedded in a host structure can be used as damage indicator. When a credible model of the healthy structure, such as the finite element model, is available, using the impedance/admittance change information as input, it is possible to identify both the location and severity of damage. The inverse analysis, however, may be under-determined as the number of unknowns in high-frequency analysis is usually large while available input information is limited. The fundamental challenge thus is how to find a small set of solutions that cover the true damage scenario. In this research we cast the damage identification problem into a multi-objective optimization framework to tackle this challenge. With damage locations and severities as unknown variables, one of the objective functions is the difference between impedance-based model prediction in the parametric space and the actual measurements. Considering that damage occurrence generally affects only a small number of elements, we choose the sparsity of the unknown variables as another objective function, deliberately, the l 0 norm. Subsequently, a multi-objective Dividing RECTangles (DIRECT) algorithm is developed to facilitate the inverse analysis where the sparsity is further emphasized by sigmoid transformation. As a deterministic technique, this approach yields results that are repeatable and conclusive. In addition, only one algorithmic parameter, the number of function evaluations, is needed. Numerical and experimental case studies demonstrate that the proposed framework is capable of obtaining high-quality damage identification solutions with limited measurement information.

Non-model-based damage identification of plates using principal, mean and Gaussian curvature mode shapes

DOE PAGES

Xu, Yongfeng F.; Zhu, Weidong D.; Smith, Scott A.

2017-07-01

Mode shapes (MSs) have been extensively used to identify structural damage. This paper presents a new non-model-based method that uses principal, mean and Gaussian curvature MSs (CMSs) to identify damage in plates; the method is applicable and robust to MSs associated with low and high elastic modes on dense and coarse measurement grids. A multi-scale discrete differential-geometry scheme is proposed to calculate principal, mean and Gaussian CMSs associated with a MS of a plate, which can alleviate adverse effects of measurement noise on calculating the CMSs. Principal, mean and Gaussian CMSs of a damaged plate and those of an undamagedmore » one are used to yield four curvature damage indices (CDIs), including Maximum-CDIs, Minimum-CDIs, Mean-CDIs and Gaussian-CDIs. Damage can be identified near regions with consistently higher values of the CDIs. It is shown that a MS of an undamaged plate can be well approximated using a polynomial with a properly determined order that fits a MS of a damaged one, provided that the undamaged plate has a smooth geometry and is made of material that has no stiffness and mass discontinuities. New fitting and convergence indices are proposed to quantify the level of approximation of a MS from a polynomial fit to that of a damaged plate and to determine the proper order of the polynomial fit, respectively. A MS of an aluminum plate with damage in the form of a machined thickness reduction area was measured to experimentally investigate the effectiveness of the proposed CDIs in damage identification; the damage on the plate was successfully identified.« less

Non-model-based damage identification of plates using principal, mean and Gaussian curvature mode shapes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Yongfeng F.; Zhu, Weidong D.; Smith, Scott A.

Mode shapes (MSs) have been extensively used to identify structural damage. This paper presents a new non-model-based method that uses principal, mean and Gaussian curvature MSs (CMSs) to identify damage in plates; the method is applicable and robust to MSs associated with low and high elastic modes on dense and coarse measurement grids. A multi-scale discrete differential-geometry scheme is proposed to calculate principal, mean and Gaussian CMSs associated with a MS of a plate, which can alleviate adverse effects of measurement noise on calculating the CMSs. Principal, mean and Gaussian CMSs of a damaged plate and those of an undamagedmore » one are used to yield four curvature damage indices (CDIs), including Maximum-CDIs, Minimum-CDIs, Mean-CDIs and Gaussian-CDIs. Damage can be identified near regions with consistently higher values of the CDIs. It is shown that a MS of an undamaged plate can be well approximated using a polynomial with a properly determined order that fits a MS of a damaged one, provided that the undamaged plate has a smooth geometry and is made of material that has no stiffness and mass discontinuities. New fitting and convergence indices are proposed to quantify the level of approximation of a MS from a polynomial fit to that of a damaged plate and to determine the proper order of the polynomial fit, respectively. A MS of an aluminum plate with damage in the form of a machined thickness reduction area was measured to experimentally investigate the effectiveness of the proposed CDIs in damage identification; the damage on the plate was successfully identified.« less

Development of a Near-Real Time Hail Damage Swath Identification Algorithm for Vegetation

NASA Technical Reports Server (NTRS)

Bell, Jordan R.; Molthan, Andrew L.; Schultz, Lori A.; McGrath, Kevin M.; Burks, Jason E.

2015-01-01

The Midwest is home to one of the world's largest agricultural growing regions. Between the time period of late May through early September, and with irrigation and seasonal rainfall these crops are able to reach their full maturity. Using moderate to high resolution remote sensors, the monitoring of the vegetation can be achieved using the red and near-infrared wavelengths. These wavelengths allow for the calculation of vegetation indices, such as Normalized Difference Vegetation Index (NDVI). The vegetation growth and greenness, in this region, grows and evolves uniformly as the growing season progresses. However one of the biggest threats to Midwest vegetation during the time period is thunderstorms that bring large hail and damaging winds. Hail and wind damage to crops can be very expensive to crop growers and, damage can be spread over long swaths associated with the tracks of the damaging storms. Damage to the vegetation can be apparent in remotely sensed imagery and is visible from space after storms slightly damage the crops, allowing for changes to occur slowly over time as the crops wilt or more readily apparent if the storms strip material from the crops or destroy them completely. Previous work on identifying these hail damage swaths used manual interpretation by the way of moderate and higher resolution satellite imagery. With the development of an automated and near-real time hail swath damage identification algorithm, detection can be improved, and more damage indicators be created in a faster and more efficient way. The automated detection of hail damage swaths will examine short-term, large changes in the vegetation by differencing near-real time eight day NDVI composites and comparing them to post storm imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard Terra and Aqua and Visible Infrared Imaging Radiometer Suite (VIIRS) aboard Suomi NPP. In addition land surface temperatures from these instruments will be examined as for hail damage swath identification. Initial validation of the automated algorithm is based upon Storm Prediction Center storm reports but also the National Severe Storm Laboratory (NSSL) Maximum Estimated Size Hail (MESH) product. Opportunities for future work are also shown, with focus on expansion of this algorithm with pixel-based image classification techniques for tracking surface changes as a result of severe weather.

Damage location and quantification of a pretensioned concrete beam using stochastic subspace identification

NASA Astrophysics Data System (ADS)

Cancelli, Alessandro; Micheli, Laura; Laflamme, Simon; Alipour, Alice; Sritharan, Sri; Ubertini, Filippo

2017-04-01

Stochastic subspace identification (SSID) is a first-order linear system identification technique enabling modal analysis through the time domain. Research in the field of structural health monitoring has demonstrated that SSID can be used to successfully retrieve modal properties, including modal damping ratios, using output-only measurements. In this paper, the utilization of SSID for indirectly retrieving structures' stiffness matrix was investigated, through the study of a simply supported reinforced concrete beam subjected to dynamic loads. Hence, by introducing a physical model of the structure, a second-order identification method is achieved. The reconstruction is based on system condensation methods, which enables calculation of reduced order stiffness, damping, and mass matrices for the structural system. The methods compute the reduced order matrices directly from the modal properties, obtained through the use of SSID. Lastly, the reduced properties of the system are used to reconstruct the stiffness matrix of the beam. The proposed approach is first verified through numerical simulations and then validated using experimental data obtained from a full-scale reinforced concrete beam that experienced progressive damage. Results show that the SSID technique can be used to diagnose, locate, and quantify damage through the reconstruction of the stiffness matrix.

Damage detection in sandwich composite materials using laser vibrometry in conjunction with nonlinear system identification

NASA Astrophysics Data System (ADS)

Underwood, Sara; Koester, David; Adams, Douglas E.

2009-03-01

Fiberglass sandwich panels are tested to study a vibration-based method for locating damage in composite materials. This method does not rely on a direct comparison of the natural frequencies, mode shapes, or residues in the forced vibration response data. Specifically, a nonlinear system identification based method for damage detection is sought that reduces the sensitivity of damage detection results to changes in vibration measurements due to variations in boundary conditions, environmental conditions, and material properties of the panel. Damage mechanisms considered include a disbond between the core and face sheet and a crack within the core. A panel is excited by a skewed piezoelectric actuator over a broad frequency range while a three-dimensional scanning laser vibrometer measures the surface velocity of the panel along three orthogonal axes. The forced frequency response data measured using the scanning laser vibrometer at multiple excitation amplitudes is processed to identify areas of the panel that exhibit significant nonlinear response characteristics. It is demonstrated that these localized nonlinearities in the panel coincide with the damaged areas of the composite material. Because changes in the measured frequency response functions due to nonlinear distortions associated with the damage can be identified without comparing the vibration data to a reference (baseline) signature of the undamaged material, this vibration technique for damage detection in composite materials exhibits less sensitivity to variations in the underlying linear characteristics than traditional methods. It is also demonstrated that the damage at a given location can be classified as either due to a disbond or core crack because these two types of damage produce difference signatures when comparing the multi-amplitude frequency response functions.

Interfacial damage identification of steel and concrete composite beams based on piezoceramic wave method.

PubMed

Yan, Shi; Dai, Yong; Zhao, Putian; Liu, Weiling

2018-01-01

Steel-concrete composite structures are playing an increasingly important role in economic construction because of a series of advantages of great stiffness, good seismic performance, steel material saving, cost efficiency, convenient construction, etc. However, in service process, due to the long-term effects of environmental impacts and dynamic loading, interfaces of a composite structure might generate debonding cracks, relative slips or separations, and so on, lowering the composite effect of the composite structure. In this paper, the piezoceramics (PZT) are used as transducers to perform experiments on interface debonding slips and separations of composite beams, respectively, aimed at proposing an interface damage identification model and a relevant damage detection innovation method based on PZT wave technology. One part of various PZT patches was embedded in concrete as "smart aggregates," and another part of the PZT patches was pasted on the surface of the steel beam flange, forming a sensor array. A push-out test for four specimens was carried out and experimental results showed that, under the action of the external loading, the received signal amplitudes will increasingly decrease with increase of debonding slips along the interface. The proposed signal energy-based interface damage detection algorithm is highly efficient in surface state evaluations of composite beams.

Life extending control: An interdisciplinary engineering thrust

NASA Technical Reports Server (NTRS)

Lorenzo, Carl F.; Merrill, Walter C.

1991-01-01

The concept of Life Extending Control (LEC) is introduced. Possible extensions to the cyclic damage prediction approach are presented based on the identification of a model from elementary forms. Several candidate elementary forms are presented. These extensions will result in a continuous or differential form of the damage prediction model. Two possible approaches to the LEC based on the existing cyclic damage prediction method, the measured variables LEC and the estimated variables LEC, are defined. Here, damage estimates or measurements would be used directly in the LEC. A simple hydraulic actuator driven position control system example is used to illustrate the main ideas behind LEC. Results from a simple hydraulic actuator example demonstrate that overall system performance (dynamic plus life) can be maximized by accounting for component damage in the control design.

Identification of delaminations in composite: structural health monitoring software based on spectral estimation and hierarchical genetic algorithm

NASA Astrophysics Data System (ADS)

Nag, A.; Mahapatra, D. Roy; Gopalakrishnan, S.

2003-10-01

A hierarchical Genetic Algorithm (GA) is implemented in a high peformance spectral finite element software for identification of delaminations in laminated composite beams. In smart structural health monitoring, the number of delaminations (or any other modes of damage) as well as their locations and sizes are no way completely known. Only known are the healthy structural configuration (mass, stiffness and damping matrices updated from previous phases of monitoring), sensor measurements and some information about the load environment. To handle such enormous complexity, a hierarchical GA is used to represent heterogeneous population consisting of damaged structures with different number of delaminations and their evolution process to identify the correct damage configuration in the structures under monitoring. We consider this similarity with the evolution process in heterogeneous population of species in nature to develop an automated procedure to decide on what possible damaged configuration might have produced the deviation in the measured signals. Computational efficiency of the identification task is demonstrated by considering a single delamination. The behavior of fitness function in GA, which is an important factor for fast convergence, is studied for single and multiple delaminations. Several advantages of the approach in terms of computational cost is discussed. Beside tackling different other types of damage configurations, further scope of research for development of hybrid soft-computing modules are highlighted.

Identification of damage in structural systems using modal data

DOT National Transportation Integrated Search

2001-04-01

To develop a useful global damage identification scheme, noise and spareseness of the measured modal data must be taken into account. Measurement noise if inevitable. If one does not consider noise and its random nature, the damage evaluation algorit...

An improved EMD method for modal identification and a combined static-dynamic method for damage detection

NASA Astrophysics Data System (ADS)

Yang, Jinping; Li, Peizhen; Yang, Youfa; Xu, Dian

2018-04-01

Empirical mode decomposition (EMD) is a highly adaptable signal processing method. However, the EMD approach has certain drawbacks, including distortions from end effects and mode mixing. In the present study, these two problems are addressed using an end extension method based on the support vector regression machine (SVRM) and a modal decomposition method based on the characteristics of the Hilbert transform. The algorithm includes two steps: using the SVRM, the time series data are extended at both endpoints to reduce the end effects, and then, a modified EMD method using the characteristics of the Hilbert transform is performed on the resulting signal to reduce mode mixing. A new combined static-dynamic method for identifying structural damage is presented. This method combines the static and dynamic information in an equilibrium equation that can be solved using the Moore-Penrose generalized matrix inverse. The combination method uses the differences in displacements of the structure with and without damage and variations in the modal force vector. Tests on a four-story, steel-frame structure were conducted to obtain static and dynamic responses of the structure. The modal parameters are identified using data from the dynamic tests and improved EMD method. The new method is shown to be more accurate and effective than the traditional EMD method. Through tests with a shear-type test frame, the higher performance of the proposed static-dynamic damage detection approach, which can detect both single and multiple damage locations and the degree of the damage, is demonstrated. For structures with multiple damage, the combined approach is more effective than either the static or dynamic method. The proposed EMD method and static-dynamic damage detection method offer improved modal identification and damage detection, respectively, in structures.

Damage detection of structures identified with deterministic-stochastic models using seismic data.

PubMed

Huang, Ming-Chih; Wang, Yen-Po; Chang, Ming-Lian

2014-01-01

A deterministic-stochastic subspace identification method is adopted and experimentally verified in this study to identify the equivalent single-input-multiple-output system parameters of the discrete-time state equation. The method of damage locating vector (DLV) is then considered for damage detection. A series of shaking table tests using a five-storey steel frame has been conducted. Both single and multiple damage conditions at various locations have been considered. In the system identification analysis, either full or partial observation conditions have been taken into account. It has been shown that the damaged stories can be identified from global responses of the structure to earthquakes if sufficiently observed. In addition to detecting damage(s) with respect to the intact structure, identification of new or extended damages of the as-damaged counterpart has also been studied. This study gives further insights into the scheme in terms of effectiveness, robustness, and limitation for damage localization of frame systems.

Stochastic output error vibration-based damage detection and assessment in structures under earthquake excitation

NASA Astrophysics Data System (ADS)

Sakellariou, J. S.; Fassois, S. D.

2006-11-01

A stochastic output error (OE) vibration-based methodology for damage detection and assessment (localization and quantification) in structures under earthquake excitation is introduced. The methodology is intended for assessing the state of a structure following potential damage occurrence by exploiting vibration signal measurements produced by low-level earthquake excitations. It is based upon (a) stochastic OE model identification, (b) statistical hypothesis testing procedures for damage detection, and (c) a geometric method (GM) for damage assessment. The methodology's advantages include the effective use of the non-stationary and limited duration earthquake excitation, the handling of stochastic uncertainties, the tackling of the damage localization and quantification subproblems, the use of "small" size, simple and partial (in both the spatial and frequency bandwidth senses) identified OE-type models, and the use of a minimal number of measured vibration signals. Its feasibility and effectiveness are assessed via Monte Carlo experiments employing a simple simulation model of a 6 storey building. It is demonstrated that damage levels of 5% and 20% reduction in a storey's stiffness characteristics may be properly detected and assessed using noise-corrupted vibration signals.

Mount St. Helens, Washington Feasibility Report & Environmental Impact Statement. Volume 1: Main Report

DTIC Science & Technology

1984-12-01

Base Condition WITH-PROJECT CONDITION Single Retention Structure Identification of NED Plan Benefits - NED Plan SENSITIVITY OF NED PLAN TO...Downstream Actions COSTS OF THE PREFERRED PLAN BENEFITS OF THE PREFERRED PLAN Economic and Social Effects Prevention of Erosion Maintenance of...continued) TABLES Residual Damages Summary of Costs Preferred Alternative Sediment MOvement Net Average Annual NED Benefits Total Flood Damages Average

A system identification technique based on the random decrement signatures. Part 2: Experimental results

NASA Technical Reports Server (NTRS)

Bedewi, Nabih E.; Yang, Jackson C. S.

1987-01-01

Identification of the system parameters of a randomly excited structure may be treated using a variety of statistical techniques. Of all these techniques, the Random Decrement is unique in that it provides the homogeneous component of the system response. Using this quality, a system identification technique was developed based on a least-squares fit of the signatures to estimate the mass, damping, and stiffness matrices of a linear randomly excited system. The results of an experiment conducted on an offshore platform scale model to verify the validity of the technique and to demonstrate its application in damage detection are presented.

Finite strain transient creep of D16T alloy: identification and validation employing heterogeneous tests

NASA Astrophysics Data System (ADS)

Shutov, A. V.; Larichkin, A. Yu

2017-10-01

A cyclic creep damage model, previously proposed by the authors, is modified for a better description of the transient creep of D16T alloy observed in the finite strain range under rapidly changing stresses. The new model encompasses the concept of kinematic hardening, which allows us to account for the creep-induced anisotropy. The model kinematics is based on the nested multiplicative split of the deformation gradient, proposed by Lion. The damage evolution is accounted for by the classical Kachanov-Rabotnov approach. The material parameters are identified using experimental data on cyclic torsion of thick-walled samples with different holding times between load reversals. For the validation of the proposed material model, an additional experiment is analyzed. Although this additional test is not involved in the identification procedure, the proposed cyclic creep damage model describes it accurately.

Identification of damage in plates using full-field measurement with a continuously scanning laser Doppler vibrometer system

NASA Astrophysics Data System (ADS)

Chen, Da-Ming; Xu, Y. F.; Zhu, W. D.

2018-05-01

An effective and reliable damage identification method for plates with a continuously scanning laser Doppler vibrometer (CSLDV) system is proposed. A new constant-speed scan algorithm is proposed to create a two-dimensional (2D) scan trajectory and automatically scan a whole plate surface. Full-field measurement of the plate can be achieved by applying the algorithm to the CSLDV system. Based on the new scan algorithm, the demodulation method is extended from one dimension for beams to two dimensions for plates to obtain a full-field operating deflection shape (ODS) of the plate from velocity response measured by the CSLDV system. The full-field ODS of an associated undamaged plate is obtained by using polynomials with proper orders to fit the corresponding full-field ODS from the demodulation method. A curvature damage index (CDI) using differences between curvatures of ODSs (CODSs) associated with ODSs that are obtained by the demodulation method and the polynomial fit is proposed to identify damage. An auxiliary CDI obtained by averaging CDIs at different excitation frequencies is defined to further assist damage identification. An experiment of an aluminum plate with damage in the form of 10.5% thickness reduction in a damage area of 0.86% of the whole scan area is conducted to investigate the proposed method. Six frequencies close to natural frequencies of the plate and one randomly selected frequency are used as sinusoidal excitation frequencies. Two 2D scan trajectories, i.e., a horizontally moving 2D scan trajectory and a vertically moving 2D scan trajectory, are used to obtain ODSs, CODSs, and CDIs of the plate. The damage is successfully identified near areas with consistently high values of CDIs at different excitation frequencies along the two 2D scan trajectories; the damage area is also identified by auxiliary CDIs.

Experimental assessment of an RFID-based crack sensor for steel structures

NASA Astrophysics Data System (ADS)

E Martínez-Castro, R.; Jang, S.; Nicholas, J.; Bansal, R.

2017-08-01

The use of welded steel cover plates had been a common design practice to increase beam section capacity in regions of high moment for decades. Many steel girder bridges with cover plates are still in service. Steel girder bridges are subject to cyclic loading, which can initiate crack formation at the toe of the weld and reduce beam capacity. Thus, timely detection of fatigue cracks is of utmost importance in steel girder bridge monitoring. To date, crack monitoring methods using in-house radio frequency identification (RFID)-based sensors have been developed to complement visual inspection and provide quantitative information of damage level. Offering similar properties at a reduced cost, commercial ultra-high frequency (UHF) passive RFID tags have been identified as a more financially viable option for pervasive crack monitoring using a dense array of sensors. This paper presents a study on damage sensitivity of low-cost commercial UHF RFID tags for crack detection and monitoring on metallic structures. Using backscatter power as a parameter for damage identification, a crack sensing system has been developed for single and multiple tag configurations for increased sensing pervasiveness. The effect on backscatter power of the existence and stage of crack propagation has been successfully characterized. For further automation of crack detection, a damage index based on the variation of backscatter power has also been established. The tested commercial RFID-based crack sensor contributes to the usage of this technology on steel girder bridges.

Damage localization by statistical evaluation of signal-processed mode shapes

NASA Astrophysics Data System (ADS)

Ulriksen, M. D.; Damkilde, L.

2015-07-01

Due to their inherent, ability to provide structural information on a local level, mode shapes and t.lieir derivatives are utilized extensively for structural damage identification. Typically, more or less advanced mathematical methods are implemented to identify damage-induced discontinuities in the spatial mode shape signals, hereby potentially facilitating damage detection and/or localization. However, by being based on distinguishing damage-induced discontinuities from other signal irregularities, an intrinsic deficiency in these methods is the high sensitivity towards measurement, noise. The present, article introduces a damage localization method which, compared to the conventional mode shape-based methods, has greatly enhanced robustness towards measurement, noise. The method is based on signal processing of spatial mode shapes by means of continuous wavelet, transformation (CWT) and subsequent, application of a generalized discrete Teager-Kaiser energy operator (GDTKEO) to identify damage-induced mode shape discontinuities. In order to evaluate whether the identified discontinuities are in fact, damage-induced, outlier analysis of principal components of the signal-processed mode shapes is conducted on the basis of T2-statistics. The proposed method is demonstrated in the context, of analytical work with a free-vibrating Euler-Bernoulli beam under noisy conditions.

System identification of a tied arch bridge using reference-based wireless sensor networks

NASA Astrophysics Data System (ADS)

Hietbrink, Colby; Whelan, Matthew J.

2012-04-01

Vibration-based methods of structural health monitoring are generally founded on the principle that localized damage to a structure would exhibit changes within the global dynamic response. Upon this basis, accelerometers provide a unique health monitoring strategy in that a distributed network of sensors provides the technical feasibility to isolate the onset of damage without requiring that any sensor be located exactly on or in close proximity to the damage. While in theory this may be sufficient, practical experience has shown significant improvement in the application of damage diagnostic routines when mode shapes characterized by strongly localized behavior of specific elements are captured by the instrumentation array. In traditional applications, this presents a challenge since the cost and complexity of cable-based systems often effectively limits the number of instrumented locations thereby constraining the modal parameter extraction to only global modal responses. The advent of the low-cost RF chip transceiver with wireless networking capabilities has afforded a means by which a substantial number of output locations can be measured through referencebased testing using large-scale wireless sensor networks. In the current study, this approach was applied to the Prairie du Chien Bridge over the Mississippi River to extract operational mode shapes with high spatial reconstruction, including strongly localized modes. The tied arch bridge was instrumented at over 230 locations with single-axis accelerometers conditioned and acquired over a high-rate lossless wireless sensor network with simultaneous sampling capabilities. Acquisition of the dynamic response of the web plates of the arch rib was specifically targeted within the instrumentation array for diagnostic purposes. Reference-based operational modal analysis of the full structure through data-driven stochastic subspace identification is presented alongside finite element analysis results for confirmation of modal parameter plausibility. Particular emphasis is placed on the identification and reconstruction of modal response with large contribution from the arch rib web plates.

Damage identification via asymmetric active magnetic bearing acceleration feedback control

NASA Astrophysics Data System (ADS)

Zhao, Jie; DeSmidt, Hans; Yao, Wei

2015-04-01

A Floquet-based damage detection methodology for cracked rotor systems is developed and demonstrated on a shaft-disk system. This approach utilizes measured changes in the system natural frequencies to estimate the severity and location of shaft structural cracks during operation. The damage detection algorithms are developed with the initial guess solved by least square method and iterative damage parameter vector by updating the eigenvector updating. Active Magnetic Bearing is introduced to break the symmetric structure of rotor system and the tuning range of proper stiffness/virtual mass gains is studied. The system model is built based on energy method and the equations of motion are derived by applying assumed modes method and Lagrange Principle. In addition, the crack model is based on the Strain Energy Release Rate (SERR) concept in fracture mechanics. Finally, the method is synthesized via harmonic balance and numerical examples for a shaft/disk system demonstrate the effectiveness in detecting both location and severity of the structural damage.

A model based bayesian solution for characterization of complex damage scenarios in aerospace composite structures.

PubMed

Reed, H; Leckey, Cara A C; Dick, A; Harvey, G; Dobson, J

2018-01-01

Ultrasonic damage detection and characterization is commonly used in nondestructive evaluation (NDE) of aerospace composite components. In recent years there has been an increased development of guided wave based methods. In real materials and structures, these dispersive waves result in complicated behavior in the presence of complex damage scenarios. Model-based characterization methods utilize accurate three dimensional finite element models (FEMs) of guided wave interaction with realistic damage scenarios to aid in defect identification and classification. This work describes an inverse solution for realistic composite damage characterization by comparing the wavenumber-frequency spectra of experimental and simulated ultrasonic inspections. The composite laminate material properties are first verified through a Bayesian solution (Markov chain Monte Carlo), enabling uncertainty quantification surrounding the characterization. A study is undertaken to assess the efficacy of the proposed damage model and comparative metrics between the experimental and simulated output. The FEM is then parameterized with a damage model capable of describing the typical complex damage created by impact events in composites. The damage is characterized through a transdimensional Markov chain Monte Carlo solution, enabling a flexible damage model capable of adapting to the complex damage geometry investigated here. The posterior probability distributions of the individual delamination petals as well as the overall envelope of the damage site are determined. Copyright © 2017 Elsevier B.V. All rights reserved.

Spectral characterization of forest damage occurring on Whiteface Mountain, NY - Studies with the Fluorescence Line Imager (FLI) and ground-based spectrometers

NASA Technical Reports Server (NTRS)

Rock, B. N.; Moss, D. M.; Miller, J. R.; Freemantle, J. R.; Boyer, M. G.

1990-01-01

Ground-based spectral characteristics of fir wave damage and an analysis of calibrated FLI data acquired along the same fir wave utilized for the in situ measurements are presented. Derivative curve data were produced from both in situ and FLI reflectance measurements for the red edge spectral region for birch and for various portions of a fir wave. The results suggested that with proper atmospheric correction of airborne imaging spectrometer data sets, the derivative curve approach will provide an accurate means of assessing red edge parameters, and that such data will permit identification of specific types of forest damage on the basis of spectral fine features.

Benchmarking Discount Rate in Natural Resource Damage Assessment with Risk Aversion.

PubMed

Wu, Desheng; Chen, Shuzhen

2017-08-01

Benchmarking a credible discount rate is of crucial importance in natural resource damage assessment (NRDA) and restoration evaluation. This article integrates a holistic framework of NRDA with prevailing low discount rate theory, and proposes a discount rate benchmarking decision support system based on service-specific risk aversion. The proposed approach has the flexibility of choosing appropriate discount rates for gauging long-term services, as opposed to decisions based simply on duration. It improves injury identification in NRDA since potential damages and side-effects to ecosystem services are revealed within the service-specific framework. A real embankment case study demonstrates valid implementation of the method. © 2017 Society for Risk Analysis.

FRF-based structural damage detection of controlled buildings with podium structures: Experimental investigation

NASA Astrophysics Data System (ADS)

Xu, Y. L.; Huang, Q.; Zhan, S.; Su, Z. Q.; Liu, H. J.

2014-06-01

How to use control devices to enhance system identification and damage detection in relation to a structure that requires both vibration control and structural health monitoring is an interesting yet practical topic. In this study, the possibility of using the added stiffness provided by control devices and frequency response functions (FRFs) to detect damage in a building complex was explored experimentally. Scale models of a 12-storey main building and a 3-storey podium structure were built to represent a building complex. Given that the connection between the main building and the podium structure is most susceptible to damage, damage to the building complex was experimentally simulated by changing the connection stiffness. To simulate the added stiffness provided by a semi-active friction damper, a steel circular ring was designed and used to add the related stiffness to the building complex. By varying the connection stiffness using an eccentric wheel excitation system and by adding or not adding the circular ring, eight cases were investigated and eight sets of FRFs were measured. The experimental results were used to detect damage (changes in connection stiffness) using a recently proposed FRF-based damage detection method. The experimental results showed that the FRF-based damage detection method could satisfactorily locate and quantify damage.

Vibration-based damage detection in wind turbine blades using Phase-based Motion Estimation and motion magnification

NASA Astrophysics Data System (ADS)

Sarrafi, Aral; Mao, Zhu; Niezrecki, Christopher; Poozesh, Peyman

2018-05-01

Vibration-based Structural Health Monitoring (SHM) techniques are among the most common approaches for structural damage identification. The presence of damage in structures may be identified by monitoring the changes in dynamic behavior subject to external loading, and is typically performed by using experimental modal analysis (EMA) or operational modal analysis (OMA). These tools for SHM normally require a limited number of physically attached transducers (e.g. accelerometers) in order to record the response of the structure for further analysis. Signal conditioners, wires, wireless receivers and a data acquisition system (DAQ) are also typical components of traditional sensing systems used in vibration-based SHM. However, instrumentation of lightweight structures with contact sensors such as accelerometers may induce mass-loading effects, and for large-scale structures, the instrumentation is labor intensive and time consuming. Achieving high spatial measurement resolution for a large-scale structure is not always feasible while working with traditional contact sensors, and there is also the potential for a lack of reliability associated with fixed contact sensors in outliving the life-span of the host structure. Among the state-of-the-art non-contact measurements, digital video cameras are able to rapidly collect high-density spatial information from structures remotely. In this paper, the subtle motions from recorded video (i.e. a sequence of images) are extracted by means of Phase-based Motion Estimation (PME) and the extracted information is used to conduct damage identification on a 2.3-m long Skystream® wind turbine blade (WTB). The PME and phased-based motion magnification approach estimates the structural motion from the captured sequence of images for both a baseline and damaged test cases on a wind turbine blade. Operational deflection shapes of the test articles are also quantified and compared for the baseline and damaged states. In addition, having proper lighting while working with high-speed cameras can be an issue, therefore image enhancement and contrast manipulation has also been performed to enhance the raw images. Ultimately, the extracted resonant frequencies and operational deflection shapes are used to detect the presence of damage, demonstrating the feasibility of implementing non-contact video measurements to perform realistic structural damage detection.

Identification of structural damage using wavelet-based data classification

NASA Astrophysics Data System (ADS)

Koh, Bong-Hwan; Jeong, Min-Joong; Jung, Uk

2008-03-01

Predicted time-history responses from a finite-element (FE) model provide a baseline map where damage locations are clustered and classified by extracted damage-sensitive wavelet coefficients such as vertical energy threshold (VET) positions having large silhouette statistics. Likewise, the measured data from damaged structure are also decomposed and rearranged according to the most dominant positions of wavelet coefficients. Having projected the coefficients to the baseline map, the true localization of damage can be identified by investigating the level of closeness between the measurement and predictions. The statistical confidence of baseline map improves as the number of prediction cases increases. The simulation results of damage detection in a truss structure show that the approach proposed in this study can be successfully applied for locating structural damage even in the presence of a considerable amount of process and measurement noise.

Evaluation of barely visible indentation damage (BVID) in CF/EP sandwich composites using guided wave signals

NASA Astrophysics Data System (ADS)

Mustapha, Samir; Ye, Lin; Dong, Xingjian; Alamdari, Mehrisadat Makki

2016-08-01

Barely visible indentation damage after quasi-static indentation in sandwich CF/EP composites was assessed using ultrasonic guided wave signals. Finite element analyses were conducted to investigate the interaction between guided waves and damage, further to assist in the selection process of the Lamb wave sensitive modes for debonding identification. Composite sandwich beams and panels structures were investigated. Using the beam structure, a damage index was defined based on the change in the peak magnitude of the captured wave signals before and after the indentation, and the damage index was correlated with the residual deformation (defined as the depth of the dent), that was further correlated with the amount of crushing within the core. Both A0 and S0 Lamb wave modes showed high sensitivity to the presence of barely visible indentation damage with residual deformation of 0.2 mm. Furthermore, barely visible indentation damage was assessed in composite sandwich panels after indenting to 3 and 5 mm, and the damage index was defined, based on (a) the peak magnitude of the wave signals before and after indentation or (b) the mismatch between the original and reconstructed wave signals based on a time-reversal algorithm, and was subsequently applied to locate the position of indentation.

Quantitative Evaluation of Hard X-ray Damage to Biological Samples using EUV Ptychography

NASA Astrophysics Data System (ADS)

Baksh, Peter; Odstrcil, Michal; Parsons, Aaron; Bailey, Jo; Deinhardt, Katrin; Chad, John E.; Brocklesby, William S.; Frey, Jeremy G.

2017-06-01

Coherent diffractive imaging (CDI) has become a standard method on a variety of synchrotron beam lines. The high brilliance short wavelength radiation from these sources can be used to reconstruct attenuation and relative phase of a sample with nanometre resolution via CDI methods. However, the interaction between the sample and high energy ionising radiation can cause degradation to sample structure. We demonstrate, using a laboratory based high harmonic generation (HHG) based extreme ultraviolet (EUV) source, imaging a sample of hippocampal neurons using the ptychography method. The significant increase in contrast of the sample in the EUV light allows identification of damage induced from exposure to 7.3 keV photons, without causing any damage to the sample itself.

Strain sensors optimal placement for vibration-based structural health monitoring. The effect of damage on the initially optimal configuration

NASA Astrophysics Data System (ADS)

Loutas, T. H.; Bourikas, A.

2017-12-01

We revisit the optimal sensor placement of engineering structures problem with an emphasis on in-plane dynamic strain measurements and to the direction of modal identification as well as vibration-based damage detection for structural health monitoring purposes. The approach utilized is based on the maximization of a norm of the Fisher Information Matrix built with numerically obtained mode shapes of the structure and at the same time prohibit the sensorization of neighbor degrees of freedom as well as those carrying similar information, in order to obtain a satisfactory coverage. A new convergence criterion of the Fisher Information Matrix (FIM) norm is proposed in order to deal with the issue of choosing an appropriate sensor redundancy threshold, a concept recently introduced but not further investigated concerning its choice. The sensor configurations obtained via a forward sequential placement algorithm are sub-optimal in terms of FIM norm values but the selected sensors are not allowed to be placed in neighbor degrees of freedom providing thus a better coverage of the structure and a subsequent better identification of the experimental mode shapes. The issue of how service induced damage affects the initially nominated as optimal sensor configuration is also investigated and reported. The numerical model of a composite sandwich panel serves as a representative aerospace structure upon which our investigations are based.

Quantifying clustered DNA damage induction and repair by gel electrophoresis, electronic imaging and number average length analysis

NASA Technical Reports Server (NTRS)

Sutherland, Betsy M.; Georgakilas, Alexandros G.; Bennett, Paula V.; Laval, Jacques; Sutherland, John C.; Gewirtz, A. M. (Principal Investigator)

2003-01-01

Assessing DNA damage induction, repair and consequences of such damages requires measurement of specific DNA lesions by methods that are independent of biological responses to such lesions. Lesions affecting one DNA strand (altered bases, abasic sites, single strand breaks (SSB)) as well as damages affecting both strands (clustered damages, double strand breaks) can be quantified by direct measurement of DNA using gel electrophoresis, gel imaging and number average length analysis. Damage frequencies as low as a few sites per gigabase pair (10(9)bp) can be quantified by this approach in about 50ng of non-radioactive DNA, and single molecule methods may allow such measurements in DNA from single cells. This review presents the theoretical basis, biochemical requirements and practical aspects of this approach, and shows examples of their applications in identification and quantitation of complex clustered damages.

A response surface methodology based damage identification technique

NASA Astrophysics Data System (ADS)

Fang, S. E.; Perera, R.

2009-06-01

Response surface methodology (RSM) is a combination of statistical and mathematical techniques to represent the relationship between the inputs and outputs of a physical system by explicit functions. This methodology has been widely employed in many applications such as design optimization, response prediction and model validation. But so far the literature related to its application in structural damage identification (SDI) is scarce. Therefore this study attempts to present a systematic SDI procedure comprising four sequential steps of feature selection, parameter screening, primary response surface (RS) modeling and updating, and reference-state RS modeling with SDI realization using the factorial design (FD) and the central composite design (CCD). The last two steps imply the implementation of inverse problems by model updating in which the RS models substitute the FE models. The proposed method was verified against a numerical beam, a tested reinforced concrete (RC) frame and an experimental full-scale bridge with the modal frequency being the output responses. It was found that the proposed RSM-based method performs well in predicting the damage of both numerical and experimental structures having single and multiple damage scenarios. The screening capacity of the FD can provide quantitative estimation of the significance levels of updating parameters. Meanwhile, the second-order polynomial model established by the CCD provides adequate accuracy in expressing the dynamic behavior of a physical system.

Rapid condition assessment of structural condition after a blast using state-space identification

NASA Astrophysics Data System (ADS)

Eskew, Edward; Jang, Shinae

2015-04-01

After a blast event, it is important to quickly quantify the structural damage for emergency operations. In order improve the speed, accuracy, and efficiency of condition assessments after a blast, the authors have previously performed work to develop a methodology for rapid assessment of the structural condition of a building after a blast. The method involved determining a post-event equivalent stiffness matrix using vibration measurements and a finite element (FE) model. A structural model was built for the damaged structure based on the equivalent stiffness, and inter-story drifts from the blast are determined using numerical simulations, with forces determined from the blast parameters. The inter-story drifts are then compared to blast design conditions to assess the structures damage. This method still involved engineering judgment in terms of determining significant frequencies, which can lead to error, especially with noisy measurements. In an effort to improve accuracy and automate the process, this paper will look into a similar method of rapid condition assessment using subspace state-space identification. The accuracy of the method will be tested using a benchmark structural model, as well as experimental testing. The blast damage assessments will be validated using pressure-impulse (P-I) diagrams, which present the condition limits across blast parameters. Comparisons between P-I diagrams generated using the true system parameters and equivalent parameters will show the accuracy of the rapid condition based blast assessments.

Fungal Diversity in Field Mold-Damaged Soybean Fruits and Pathogenicity Identification Based on High-Throughput rDNA Sequencing

PubMed Central

Liu, Jiang; Deng, Jun-cai; Yang, Cai-qiong; Huang, Ni; Chang, Xiao-li; Zhang, Jing; Yang, Feng; Liu, Wei-guo; Wang, Xiao-chun; Yong, Tai-wen; Du, Jun-bo; Shu, Kai; Yang, Wen-yu

2017-01-01

Continuous rain and an abnormally wet climate during harvest can easily lead to soybean plants being damaged by field mold (FM), which can reduce seed yield and quality. However, to date, the underlying pathogen and its resistance mechanism have remained unclear. The objective of the present study was to investigate the fungal diversity of various soybean varieties and to identify and confirm the FM pathogenic fungi. A total of 62,382 fungal ITS1 sequences clustered into 164 operational taxonomic units (OTUs) with 97% sequence similarity; 69 taxa were recovered from the samples by internal transcribed spacer (ITS) region sequencing. The fungal community compositions differed among the tested soybeans, with 42 OTUs being amplified from all varieties. The quadratic relationships between fungal diversity and organ-specific mildew indexes were analyzed, confirming that mildew on soybean pods can mitigate FM damage to the seeds. In addition, four potentially pathogenic fungi were isolated from FM-damaged soybean fruits; morphological and molecular identification confirmed these fungi as Aspergillus flavus, A. niger, Fusarium moniliforme, and Penicillium chrysogenum. Further re-inoculation experiments demonstrated that F. moniliforme is dominant among these FM pathogenic fungi. These results lay the foundation for future studies on mitigating or preventing FM damage to soybean. PMID:28515718

Nucleic Acid-Based Biosensors for the Detection of DNA Damage

EPA Science Inventory

Monitoring the environment for the presence of toxic compounds is not only required for cleanup of previously contaminated land and water, but is important for preventing future contamination and managing risks to human health and the environment. Identification and measurement o...

A Tensor-Based Structural Damage Identification and Severity Assessment

PubMed Central

Anaissi, Ali; Makki Alamdari, Mehrisadat; Rakotoarivelo, Thierry; Khoa, Nguyen Lu Dang

2018-01-01

Early damage detection is critical for a large set of global ageing infrastructure. Structural Health Monitoring systems provide a sensor-based quantitative and objective approach to continuously monitor these structures, as opposed to traditional engineering visual inspection. Analysing these sensed data is one of the major Structural Health Monitoring (SHM) challenges. This paper presents a novel algorithm to detect and assess damage in structures such as bridges. This method applies tensor analysis for data fusion and feature extraction, and further uses one-class support vector machine on this feature to detect anomalies, i.e., structural damage. To evaluate this approach, we collected acceleration data from a sensor-based SHM system, which we deployed on a real bridge and on a laboratory specimen. The results show that our tensor method outperforms a state-of-the-art approach using the wavelet energy spectrum of the measured data. In the specimen case, our approach succeeded in detecting 92.5% of induced damage cases, as opposed to 61.1% for the wavelet-based approach. While our method was applied to bridges, its algorithm and computation can be used on other structures or sensor-data analysis problems, which involve large series of correlated data from multiple sensors. PMID:29301314

Features of Cross-Correlation Analysis in a Data-Driven Approach for Structural Damage Assessment

PubMed Central

Camacho Navarro, Jhonatan; Ruiz, Magda; Villamizar, Rodolfo; Mujica, Luis

2018-01-01

This work discusses the advantage of using cross-correlation analysis in a data-driven approach based on principal component analysis (PCA) and piezodiagnostics to obtain successful diagnosis of events in structural health monitoring (SHM). In this sense, the identification of noisy data and outliers, as well as the management of data cleansing stages can be facilitated through the implementation of a preprocessing stage based on cross-correlation functions. Additionally, this work evidences an improvement in damage detection when the cross-correlation is included as part of the whole damage assessment approach. The proposed methodology is validated by processing data measurements from piezoelectric devices (PZT), which are used in a piezodiagnostics approach based on PCA and baseline modeling. Thus, the influence of cross-correlation analysis used in the preprocessing stage is evaluated for damage detection by means of statistical plots and self-organizing maps. Three laboratory specimens were used as test structures in order to demonstrate the validity of the methodology: (i) a carbon steel pipe section with leak and mass damage types, (ii) an aircraft wing specimen, and (iii) a blade of a commercial aircraft turbine, where damages are specified as mass-added. As the main concluding remark, the suitability of cross-correlation features combined with a PCA-based piezodiagnostic approach in order to achieve a more robust damage assessment algorithm is verified for SHM tasks. PMID:29762505

Features of Cross-Correlation Analysis in a Data-Driven Approach for Structural Damage Assessment.

PubMed

Camacho Navarro, Jhonatan; Ruiz, Magda; Villamizar, Rodolfo; Mujica, Luis; Quiroga, Jabid

2018-05-15

This work discusses the advantage of using cross-correlation analysis in a data-driven approach based on principal component analysis (PCA) and piezodiagnostics to obtain successful diagnosis of events in structural health monitoring (SHM). In this sense, the identification of noisy data and outliers, as well as the management of data cleansing stages can be facilitated through the implementation of a preprocessing stage based on cross-correlation functions. Additionally, this work evidences an improvement in damage detection when the cross-correlation is included as part of the whole damage assessment approach. The proposed methodology is validated by processing data measurements from piezoelectric devices (PZT), which are used in a piezodiagnostics approach based on PCA and baseline modeling. Thus, the influence of cross-correlation analysis used in the preprocessing stage is evaluated for damage detection by means of statistical plots and self-organizing maps. Three laboratory specimens were used as test structures in order to demonstrate the validity of the methodology: (i) a carbon steel pipe section with leak and mass damage types, (ii) an aircraft wing specimen, and (iii) a blade of a commercial aircraft turbine, where damages are specified as mass-added. As the main concluding remark, the suitability of cross-correlation features combined with a PCA-based piezodiagnostic approach in order to achieve a more robust damage assessment algorithm is verified for SHM tasks.

Behavioral pattern identification for structural health monitoring in complex systems

NASA Astrophysics Data System (ADS)

Gupta, Shalabh

Estimation of structural damage and quantification of structural integrity are critical for safe and reliable operation of human-engineered complex systems, such as electromechanical, thermofluid, and petrochemical systems. Damage due to fatigue crack is one of the most commonly encountered sources of structural degradation in mechanical systems. Early detection of fatigue damage is essential because the resulting structural degradation could potentially cause catastrophic failures, leading to loss of expensive equipment and human life. Therefore, for reliable operation and enhanced availability, it is necessary to develop capabilities for prognosis and estimation of impending failures, such as the onset of wide-spread fatigue crack damage in mechanical structures. This dissertation presents information-based online sensing of fatigue damage using the analytical tools of symbolic time series analysis ( STSA). Anomaly detection using STSA is a pattern recognition method that has been recently developed based upon a fixed-structure, fixed-order Markov chain. The analysis procedure is built upon the principles of Symbolic Dynamics, Information Theory and Statistical Pattern Recognition. The dissertation demonstrates real-time fatigue damage monitoring based on time series data of ultrasonic signals. Statistical pattern changes are measured using STSA to monitor the evolution of fatigue damage. Real-time anomaly detection is presented as a solution to the forward (analysis) problem and the inverse (synthesis) problem. (1) the forward problem - The primary objective of the forward problem is identification of the statistical changes in the time series data of ultrasonic signals due to gradual evolution of fatigue damage. (2) the inverse problem - The objective of the inverse problem is to infer the anomalies from the observed time series data in real time based on the statistical information generated during the forward problem. A computer-controlled special-purpose fatigue test apparatus, equipped with multiple sensing devices (e.g., ultrasonics and optical microscope) for damage analysis, has been used to experimentally validate the STSA method for early detection of anomalous behavior. The sensor information is integrated with a software module consisting of the STSA algorithm for real-time monitoring of fatigue damage. Experiments have been conducted under different loading conditions on specimens constructed from the ductile aluminium alloy 7075 - T6. The dissertation has also investigated the application of the STSA method for early detection of anomalies in other engineering disciplines. Two primary applications include combustion instability in a generic thermal pulse combustor model and whirling phenomenon in a typical misaligned shaft.

Development and validation of an automated operational modal analysis algorithm for vibration-based monitoring and tensile load estimation

NASA Astrophysics Data System (ADS)

Rainieri, Carlo; Fabbrocino, Giovanni

2015-08-01

In the last few decades large research efforts have been devoted to the development of methods for automated detection of damage and degradation phenomena at an early stage. Modal-based damage detection techniques are well-established methods, whose effectiveness for Level 1 (existence) and Level 2 (location) damage detection is demonstrated by several studies. The indirect estimation of tensile loads in cables and tie-rods is another attractive application of vibration measurements. It provides interesting opportunities for cheap and fast quality checks in the construction phase, as well as for safety evaluations and structural maintenance over the structure lifespan. However, the lack of automated modal identification and tracking procedures has been for long a relevant drawback to the extensive application of the above-mentioned techniques in the engineering practice. An increasing number of field applications of modal-based structural health and performance assessment are appearing after the development of several automated output-only modal identification procedures in the last few years. Nevertheless, additional efforts are still needed to enhance the robustness of automated modal identification algorithms, control the computational efforts and improve the reliability of modal parameter estimates (in particular, damping). This paper deals with an original algorithm for automated output-only modal parameter estimation. Particular emphasis is given to the extensive validation of the algorithm based on simulated and real datasets in view of continuous monitoring applications. The results point out that the algorithm is fairly robust and demonstrate its ability to provide accurate and precise estimates of the modal parameters, including damping ratios. As a result, it has been used to develop systems for vibration-based estimation of tensile loads in cables and tie-rods. Promising results have been achieved for non-destructive testing as well as continuous monitoring purposes. They are documented in the last sections of the paper.

Nonlinear finite element model updating for damage identification of civil structures using batch Bayesian estimation

NASA Astrophysics Data System (ADS)

Ebrahimian, Hamed; Astroza, Rodrigo; Conte, Joel P.; de Callafon, Raymond A.

2017-02-01

This paper presents a framework for structural health monitoring (SHM) and damage identification of civil structures. This framework integrates advanced mechanics-based nonlinear finite element (FE) modeling and analysis techniques with a batch Bayesian estimation approach to estimate time-invariant model parameters used in the FE model of the structure of interest. The framework uses input excitation and dynamic response of the structure and updates a nonlinear FE model of the structure to minimize the discrepancies between predicted and measured response time histories. The updated FE model can then be interrogated to detect, localize, classify, and quantify the state of damage and predict the remaining useful life of the structure. As opposed to recursive estimation methods, in the batch Bayesian estimation approach, the entire time history of the input excitation and output response of the structure are used as a batch of data to estimate the FE model parameters through a number of iterations. In the case of non-informative prior, the batch Bayesian method leads to an extended maximum likelihood (ML) estimation method to estimate jointly time-invariant model parameters and the measurement noise amplitude. The extended ML estimation problem is solved efficiently using a gradient-based interior-point optimization algorithm. Gradient-based optimization algorithms require the FE response sensitivities with respect to the model parameters to be identified. The FE response sensitivities are computed accurately and efficiently using the direct differentiation method (DDM). The estimation uncertainties are evaluated based on the Cramer-Rao lower bound (CRLB) theorem by computing the exact Fisher Information matrix using the FE response sensitivities with respect to the model parameters. The accuracy of the proposed uncertainty quantification approach is verified using a sampling approach based on the unscented transformation. Two validation studies, based on realistic structural FE models of a bridge pier and a moment resisting steel frame, are performed to validate the performance and accuracy of the presented nonlinear FE model updating approach and demonstrate its application to SHM. These validation studies show the excellent performance of the proposed framework for SHM and damage identification even in the presence of high measurement noise and/or way-out initial estimates of the model parameters. Furthermore, the detrimental effects of the input measurement noise on the performance of the proposed framework are illustrated and quantified through one of the validation studies.

Intelligent Multi-scale Sensors for Damage Identification and Mitigation in Woven Composites for Aerospace Structural Applications

DTIC Science & Technology

2012-08-15

Bragg grating ( FBG ) sensors within these composite structures allows one to correlate sensor response features to “critical damage events” within the...material. The unique capabilities of this identification strategy are due to the detailed information obtained from the FBG sensors and the... FBG sensors relate to damage states not merely strain amplitudes. The research objectives of this project were therefore to:  demonstrate FBG

Investigation of Time Series Representations and Similarity Measures for Structural Damage Pattern Recognition

PubMed Central

Swartz, R. Andrew

2013-01-01

This paper investigates the time series representation methods and similarity measures for sensor data feature extraction and structural damage pattern recognition. Both model-based time series representation and dimensionality reduction methods are studied to compare the effectiveness of feature extraction for damage pattern recognition. The evaluation of feature extraction methods is performed by examining the separation of feature vectors among different damage patterns and the pattern recognition success rate. In addition, the impact of similarity measures on the pattern recognition success rate and the metrics for damage localization are also investigated. The test data used in this study are from the System Identification to Monitor Civil Engineering Structures (SIMCES) Z24 Bridge damage detection tests, a rigorous instrumentation campaign that recorded the dynamic performance of a concrete box-girder bridge under progressively increasing damage scenarios. A number of progressive damage test case datasets and damage test data with different damage modalities are used. The simulation results show that both time series representation methods and similarity measures have significant impact on the pattern recognition success rate. PMID:24191136

Stochastic filtering for damage identification through nonlinear structural finite element model updating

NASA Astrophysics Data System (ADS)

Astroza, Rodrigo; Ebrahimian, Hamed; Conte, Joel P.

2015-03-01

This paper describes a novel framework that combines advanced mechanics-based nonlinear (hysteretic) finite element (FE) models and stochastic filtering techniques to estimate unknown time-invariant parameters of nonlinear inelastic material models used in the FE model. Using input-output data recorded during earthquake events, the proposed framework updates the nonlinear FE model of the structure. The updated FE model can be directly used for damage identification and further used for damage prognosis. To update the unknown time-invariant parameters of the FE model, two alternative stochastic filtering methods are used: the extended Kalman filter (EKF) and the unscented Kalman filter (UKF). A three-dimensional, 5-story, 2-by-1 bay reinforced concrete (RC) frame is used to verify the proposed framework. The RC frame is modeled using fiber-section displacement-based beam-column elements with distributed plasticity and is subjected to the ground motion recorded at the Sylmar station during the 1994 Northridge earthquake. The results indicate that the proposed framework accurately estimate the unknown material parameters of the nonlinear FE model. The UKF outperforms the EKF when the relative root-mean-square error of the recorded responses are compared. In addition, the results suggest that the convergence of the estimate of modeling parameters is smoother and faster when the UKF is utilized.

Damage identification using inverse methods.

PubMed

Friswell, Michael I

2007-02-15

This paper gives an overview of the use of inverse methods in damage detection and location, using measured vibration data. Inverse problems require the use of a model and the identification of uncertain parameters of this model. Damage is often local in nature and although the effect of the loss of stiffness may require only a small number of parameters, the lack of knowledge of the location means that a large number of candidate parameters must be included. This paper discusses a number of problems that exist with this approach to health monitoring, including modelling error, environmental effects, damage localization and regularization.

Minimum constitutive relation error based static identification of beams using force method

NASA Astrophysics Data System (ADS)

Guo, Jia; Takewaki, Izuru

2017-05-01

A new static identification approach based on the minimum constitutive relation error (CRE) principle for beam structures is introduced. The exact stiffness and the exact bending moment are shown to make the CRE minimal for given displacements to beam damages. A two-step substitution algorithm—a force-method step for the bending moment and a constitutive-relation step for the stiffness—is developed and its convergence is rigorously derived. Identifiability is further discussed and the stiffness in the undeformed region is found to be unidentifiable. An extra set of static measurements is complemented to remedy the drawback. Convergence and robustness are finally verified through numerical examples.

Identification of unique volatile compounds associated with repelling whiteflies (Hemiptera: Aleyrodidae) in desert watermelon (Citrullus colocynthis)

USDA-ARS?s Scientific Manuscript database

Commercial watermelon cultivars (Citrullus lanatus var. lanatus) share a narrow genetic base and are susceptible to many insect pests and diseases. The insects include whiteflies which cause serious economic damages to this important cucurbit crop. However, several United States Plant Introduction a...

On experimental damage localization by SP2E: Application of H∞ estimation and oblique projections

NASA Astrophysics Data System (ADS)

Lenzen, Armin; Vollmering, Max

2018-05-01

In this article experimental damage localization based on H∞ estimation and state projection estimation error (SP2E) is studied. Based on an introduced difference process, a state space representation is derived for advantageous numerical solvability. Because real structural excitations are presumed to be unknown, a general input is applied therein, which allows synchronization and normalization. Furthermore, state projections are introduced to enhance damage identification. While first experiments to verify method SP2E have already been conducted and published, further laboratory results are analyzed here. Therefore, SP2E is used to experimentally localize stiffness degradations and mass alterations. Furthermore, the influence of projection techniques is analyzed. In summary, method SP2E is able to localize structural alterations, which has been observed by results of laboratory experiments.

Study of Composite Plate Damages Using Embedded PZT Sensors with Various Center Frequency

NASA Astrophysics Data System (ADS)

Kang, Kyoung-Tak; Chun, Heoung-Jae; Son, Ju-Hyun; Byun, Joon-Hyung; Um, Moon-Kwang; Lee, Sang-Kwan

This study presents part of an experimental and analytical survey of candidate methods for damage detection of composite structural. Embedded piezoceramic (PZT) sensors were excited with the high power ultrasonic wave generator generating a propagation of stress wave along the composite plate. The same embedded piezoceramic (PZT) sensors are used as receivers for acquiring stress signals. The effects of center frequency of embedded sensor were evaluated for the damage identification capability with known localized defects. The study was carried out to assess damage in composite plate by fusing information from multiple sensing paths of the embedded network. It was based on the Hilbert transform, signal correlation and probabilistic searching. The obtained results show that satisfactory detection of defects could be achieved by proposed method.

Extended Kalman filtering for the detection of damage in linear mechanical structures

NASA Astrophysics Data System (ADS)

Liu, X.; Escamilla-Ambrosio, P. J.; Lieven, N. A. J.

2009-09-01

This paper addresses the problem of assessing the location and extent of damage in a vibrating structure by means of vibration measurements. Frequency domain identification methods (e.g. finite element model updating) have been widely used in this area while time domain methods such as the extended Kalman filter (EKF) method, are more sparsely represented. The difficulty of applying EKF in mechanical system damage identification and localisation lies in: the high computational cost, the dependence of estimation results on the initial estimation error covariance matrix P(0), the initial value of parameters to be estimated, and on the statistics of measurement noise R and process noise Q. To resolve these problems in the EKF, a multiple model adaptive estimator consisting of a bank of EKF in modal domain was designed, each filter in the bank is based on different P(0). The algorithm was iterated by using the weighted global iteration method. A fuzzy logic model was incorporated in each filter to estimate the variance of the measurement noise R. The application of the method is illustrated by simulated and real examples.

Environmental durability diagnostic for printed identification codes of polymer insulation for distribution pipelines

NASA Astrophysics Data System (ADS)

Zhuravleva, G. N.; Nagornova, I. V.; Kondratov, A. P.; Bablyuk, E. B.; Varepo, L. G.

2017-08-01

A research and modelling of weatherability and environmental durability of multilayer polymer insulation of both cable and pipelines with printed barcodes or color identification information were performed. It was proved that interlayer printing of identification codes in distribution pipelines insulation coatings provides high marking stability to light and atmospheric condensation. This allows to carry out their distant damage control. However, microbiological fouling of upper polymer layer hampers the distant damage pipelines identification. The color difference values and density changes of PE and PVC printed insolation due to weather and biological factors were defined.

Study of cumulative fatigue damage detection for used parts with nonlinear output frequency response functions based on NARMAX modelling

NASA Astrophysics Data System (ADS)

Huang, Honglan; Mao, Hanying; Mao, Hanling; Zheng, Weixue; Huang, Zhenfeng; Li, Xinxin; Wang, Xianghong

2017-12-01

Cumulative fatigue damage detection for used parts plays a key role in the process of remanufacturing engineering and is related to the service safety of the remanufactured parts. In light of the nonlinear properties of used parts caused by cumulative fatigue damage, the based nonlinear output frequency response functions detection approach offers a breakthrough to solve this key problem. First, a modified PSO-adaptive lasso algorithm is introduced to improve the accuracy of the NARMAX model under impulse hammer excitation, and then, an effective new algorithm is derived to estimate the nonlinear output frequency response functions under rectangular pulse excitation, and a based nonlinear output frequency response functions index is introduced to detect the cumulative fatigue damage in used parts. Then, a novel damage detection approach that integrates the NARMAX model and the rectangular pulse is proposed for nonlinear output frequency response functions identification and cumulative fatigue damage detection of used parts. Finally, experimental studies of fatigued plate specimens and used connecting rod parts are conducted to verify the validity of the novel approach. The obtained results reveal that the new approach can detect cumulative fatigue damages of used parts effectively and efficiently and that the various values of the based nonlinear output frequency response functions index can be used to detect the different fatigue damages or working time. Since the proposed new approach can extract nonlinear properties of systems by only a single excitation of the inspected system, it shows great promise for use in remanufacturing engineering applications.

Study on Failure of Third-Party Damage for Urban Gas Pipeline Based on Fuzzy Comprehensive Evaluation.

PubMed

Li, Jun; Zhang, Hong; Han, Yinshan; Wang, Baodong

2016-01-01

Focusing on the diversity, complexity and uncertainty of the third-party damage accident, the failure probability of third-party damage to urban gas pipeline was evaluated on the theory of analytic hierarchy process and fuzzy mathematics. The fault tree of third-party damage containing 56 basic events was built by hazard identification of third-party damage. The fuzzy evaluation of basic event probabilities were conducted by the expert judgment method and using membership function of fuzzy set. The determination of the weight of each expert and the modification of the evaluation opinions were accomplished using the improved analytic hierarchy process, and the failure possibility of the third-party to urban gas pipeline was calculated. Taking gas pipelines of a certain large provincial capital city as an example, the risk assessment structure of the method was proved to conform to the actual situation, which provides the basis for the safety risk prevention.

[A Comparison Study on Early Damage Detection of Left Ventricular Function Based on Doppler Imaging Method for Children with Tumor].

PubMed

Liu, Ying; Zhang, Haowei; Zhang, Hang

2015-12-01

The early damage detection and evaluation are of great significance in treatment and prognosis to the left ventricular function for children with tumor. In this paper, it is reported that the early damage of the left ventricular function was observed by pulsed wave Doppler (PWD) and tissue Doppler imaging (TDI) in our laboratory. Eighty children half a year to fourteen years old were included in this study. The cardiac function indices in chemotherapy group and control group were measured and compared. The results showed that there was significant difference in mitral and tricuspid annulus flow spectrum between the two groups. Compared with PWD,TDI is more prompt, objective and accurate in detecting early damage of left ventricular function in children with tumor. And TDI is a good method for early identification of ventricular function damage in children with tumor.

Autoregressive statistical pattern recognition algorithms for damage detection in civil structures

NASA Astrophysics Data System (ADS)

Yao, Ruigen; Pakzad, Shamim N.

2012-08-01

Statistical pattern recognition has recently emerged as a promising set of complementary methods to system identification for automatic structural damage assessment. Its essence is to use well-known concepts in statistics for boundary definition of different pattern classes, such as those for damaged and undamaged structures. In this paper, several statistical pattern recognition algorithms using autoregressive models, including statistical control charts and hypothesis testing, are reviewed as potentially competitive damage detection techniques. To enhance the performance of statistical methods, new feature extraction techniques using model spectra and residual autocorrelation, together with resampling-based threshold construction methods, are proposed. Subsequently, simulated acceleration data from a multi degree-of-freedom system is generated to test and compare the efficiency of the existing and proposed algorithms. Data from laboratory experiments conducted on a truss and a large-scale bridge slab model are then used to further validate the damage detection methods and demonstrate the superior performance of proposed algorithms.

Acoustic emission monitoring and critical failure identification of bridge cable damage

NASA Astrophysics Data System (ADS)

Li, Dongsheng; Ou, Jinping

2008-03-01

Acoustic emission (AE) characteristic parameters of bridge cable damage were obtained on tensile test. The testing results show that the AE parameter analysis method based on correlation figure of count, energy, duration time, amplitude and time can express the whole damage course, and can correctly judge the signal difference of broken wire and unbroken wire. It found the bridge cable AE characteristics aren't apparent before yield deformation, however they are increasing after yield deformation, at the time of breaking, and they reach to maximum. At last, the bridge cable damage evolution law is studied applying the AE characteristic parameter time series fractal theory. In the initial and middle stage of loading, the AE fractal value of bridge cable is unsteady. The fractal value reaches to the minimum at the critical point of failure. According to this changing law, it is approached how to make dynamic assessment and estimation of damage degrees.

A new qualitative acoustic emission parameter based on Shannon's entropy for damage monitoring

NASA Astrophysics Data System (ADS)

Chai, Mengyu; Zhang, Zaoxiao; Duan, Quan

2018-02-01

An important objective of acoustic emission (AE) non-destructive monitoring is to accurately identify approaching critical damage and to avoid premature failure by means of the evolutions of AE parameters. One major drawback of most parameters such as count and rise time is that they are strongly dependent on the threshold and other settings employed in AE data acquisition system. This may hinder the correct reflection of original waveform generated from AE sources and consequently bring difficulty for the accurate identification of the critical damage and early failure. In this investigation, a new qualitative AE parameter based on Shannon's entropy, i.e. AE entropy is proposed for damage monitoring. Since it derives from the uncertainty of amplitude distribution of each AE waveform, it is independent of the threshold and other time-driven parameters and can characterize the original micro-structural deformations. Fatigue crack growth test on CrMoV steel and three point bending test on a ductile material are conducted to validate the feasibility and effectiveness of the proposed parameter. The results show that the new parameter, compared to AE amplitude, is more effective in discriminating the different damage stages and identifying the critical damage.

DNA-based identification of Armillaria isolates from peach orchards in Mexico state

Treesearch

Ruben Damian Elias Roman; Ned B. Klopfenstein; Dionicio Alvarado Rosales; Mee-Sook Kim; Anna E. Case; Sara M. Ashiglar; John W. Hanna; Amy L. Ross-Davis; Remigio A. Guzman Plazola

2012-01-01

A collaborative project between the Programa de Fitopatología, Colegio de Postgraduados, Texcoco, Estado de Mexico and the USDA Forest Service - RMRS, Moscow Forest Pathology Laboratory has begun this year (2011) to assess which species of Armillaria are causing widespread and severe damage to the peach orchards from México state, Mexico. We are employing a DNA-based...

Reconstruction of structural damage based on reflection intensity spectra of fiber Bragg gratings

NASA Astrophysics Data System (ADS)

Huang, Guojun; Wei, Changben; Chen, Shiyuan; Yang, Guowei

2014-12-01

We present an approach for structural damage reconstruction based on the reflection intensity spectra of fiber Bragg gratings (FBGs). Our approach incorporates the finite element method, transfer matrix (T-matrix), and genetic algorithm to solve the inverse photo-elastic problem of damage reconstruction, i.e. to identify the location, size, and shape of a defect. By introducing a parameterized characterization of the damage information, the inverse photo-elastic problem is reduced to an optimization problem, and a relevant computational scheme was developed. The scheme iteratively searches for the solution to the corresponding direct photo-elastic problem until the simulated and measured (or target) reflection intensity spectra of the FBGs near the defect coincide within a prescribed error. Proof-of-concept validations of our approach were performed numerically and experimentally using both holed and cracked plate samples as typical cases of plane-stress problems. The damage identifiability was simulated by changing the deployment of the FBG sensors, including the total number of sensors and their distance to the defect. Both the numerical and experimental results demonstrate that our approach is effective and promising. It provides us with a photo-elastic method for developing a remote, automatic damage-imaging technique that substantially improves damage identification for structural health monitoring.

Covariance of dynamic strain responses for structural damage detection

NASA Astrophysics Data System (ADS)

Li, X. Y.; Wang, L. X.; Law, S. S.; Nie, Z. H.

2017-10-01

A new approach to address the practical problems with condition evaluation/damage detection of structures is proposed based on the distinct features of a new damage index. The covariance of strain response function (CoS) is a function of modal parameters of the structure. A local stiffness reduction in structure would cause monotonous increase in the CoS. Its sensitivity matrix with respect to local damages of structure is negative and narrow-banded. The damage extent can be estimated with an approximation to the sensitivity matrix to decouple the identification equations. The CoS sensitivity can be calibrated in practice from two previous states of measurements to estimate approximately the damage extent of a structure. A seven-storey plane frame structure is numerically studied to illustrate the features of the CoS index and the proposed method. A steel circular arch in the laboratory is tested. Natural frequencies changed due to damage in the arch and the damage occurrence can be judged. However, the proposed CoS method can identify not only damage happening but also location, even damage extent without need of an analytical model. It is promising for structural condition evaluation of selected components.

Experimental validation of a structural damage detection method based on marginal Hilbert spectrum

NASA Astrophysics Data System (ADS)

Banerji, Srishti; Roy, Timir B.; Sabamehr, Ardalan; Bagchi, Ashutosh

2017-04-01

Structural Health Monitoring (SHM) using dynamic characteristics of structures is crucial for early damage detection. Damage detection can be performed by capturing and assessing structural responses. Instrumented structures are monitored by analyzing the responses recorded by deployed sensors in the form of signals. Signal processing is an important tool for the processing of the collected data to diagnose anomalies in structural behavior. The vibration signature of the structure varies with damage. In order to attain effective damage detection, preservation of non-linear and non-stationary features of real structural responses is important. Decomposition of the signals into Intrinsic Mode Functions (IMF) by Empirical Mode Decomposition (EMD) and application of Hilbert-Huang Transform (HHT) addresses the time-varying instantaneous properties of the structural response. The energy distribution among different vibration modes of the intact and damaged structure depicted by Marginal Hilbert Spectrum (MHS) detects location and severity of the damage. The present work investigates damage detection analytically and experimentally by employing MHS. The testing of this methodology for different damage scenarios of a frame structure resulted in its accurate damage identification. The sensitivity of Hilbert Spectral Analysis (HSA) is assessed with varying frequencies and damage locations by means of calculating Damage Indices (DI) from the Hilbert spectrum curves of the undamaged and damaged structures.

Effects of high temperature on different restorations in forensic identification: Dental samples and mandible

PubMed Central

Patidar, Kalpana A; Parwani, Rajkumar; Wanjari, Sangeeta

2010-01-01

Introduction: The forensic odontologist strives to utilize the charred human dentition throughout each stage of dental evaluation, and restorations are as unique as fingerprints and their radiographic morphology as well as the types of filling materials are often the main feature for identification. The knowledge of detecting residual restorative material and composition of unrecovered adjacent restoration is a valuable tool-mark in the presumptive identification of the dentition of a burned victim. Gold, silver amalgam, silicate restoration, and so on, have a different resistance to prolonged high temperature, therefore, the identification of burned bodies can be correlated with adequate qualities and quantities of the traces. Most of the dental examination relies heavily on the presence of the restoration as well as the relationship of one dental structure to another. This greatly narrows the research for the final identification that is based on postmortem data. Aim: The purpose of this study is to examine the resistance of teeth and different restorative materials, and the mandible, to variable temperature and duration, for the purpose of identification. Materials and Methods: The study was conducted on 72 extracted teeth which were divided into six goups of 12 teeth each based on the type of restorative material. (Group 1 - unrestored teeth, group 2 - teeth restored with Zn3(PO4)2, group 3 - with silver amalgam, group 4 with glass ionomer cement, group 5 - Ni-Cr-metal crown, group 6 - metal ceramic crown) and two specimens of the mandible. The effect of incineration at 400°C (5 mins, 15 mins, 30 mins) and 1100°C (15 mins) was studied. Results: Damage to the teeth subjected to variable temperatures and time can be categorized as intact (no damage), scorched (superficially parched and discolored), charred (reduced to carbon by incomplete combustion) and incinerated (burned to ashes). PMID:21189989

Identification of ATM Protein Kinase Phosphorylation Sites by Mass Spectrometry.

PubMed

Graham, Mark E; Lavin, Martin F; Kozlov, Sergei V

2017-01-01

ATM (ataxia-telangiectasia mutated) protein kinase is a key regulator of cellular responses to DNA damage and oxidative stress. DNA damage triggers complex cascade of signaling events leading to numerous posttranslational modification on multitude of proteins. Understanding the regulation of ATM kinase is therefore critical not only for understanding the human genetic disorder ataxia-telangiectasia and potential treatment strategies, but essential for deciphering physiological responses of cells to stress. These responses play an important role in carcinogenesis, neurodegeneration, and aging. We focus here on the identification of DNA damage inducible ATM phosphorylation sites to understand the importance of autophosphorylation in the mechanism of ATM kinase activation. We demonstrate the utility of using immunoprecipitated ATM in quantitative LC-MS/MS workflow with stable isotope dimethyl labeling of ATM peptides for identification of phosphorylation sites.

Identification of modal strains using sub-microstrain FBG data and a novel wavelength-shift detection algorithm

NASA Astrophysics Data System (ADS)

Anastasopoulos, Dimitrios; Moretti, Patrizia; Geernaert, Thomas; De Pauw, Ben; Nawrot, Urszula; De Roeck, Guido; Berghmans, Francis; Reynders, Edwin

2017-03-01

The presence of damage in a civil structure alters its stiffness and consequently its modal characteristics. The identification of these changes can provide engineers with useful information about the condition of a structure and constitutes the basic principle of the vibration-based structural health monitoring. While eigenfrequencies and mode shapes are the most commonly monitored modal characteristics, their sensitivity to structural damage may be low relative to their sensitivity to environmental influences. Modal strains or curvatures could offer an attractive alternative but current measurement techniques encounter difficulties in capturing the very small strain (sub-microstrain) levels occurring during ambient, or operational excitation, with sufficient accuracy. This paper investigates the ability to obtain sub-microstrain accuracy with standard fiber-optic Bragg gratings using a novel optical signal processing algorithm that identifies the wavelength shift with high accuracy and precision. The novel technique is validated in an extensive experimental modal analysis test on a steel I-beam which is instrumented with FBG sensors at its top and bottom flange. The raw wavelength FBG data are processed into strain values using both a novel correlation-based processing technique and a conventional peak tracking technique. Subsequently, the strain time series are used for identifying the beam's modal characteristics. Finally, the accuracy of both algorithms in identification of modal characteristics is extensively investigated.

Quantitative evaluation for small surface damage based on iterative difference and triangulation of 3D point cloud

NASA Astrophysics Data System (ADS)

Zhang, Yuyan; Guo, Quanli; Wang, Zhenchun; Yang, Degong

2018-03-01

This paper proposes a non-contact, non-destructive evaluation method for the surface damage of high-speed sliding electrical contact rails. The proposed method establishes a model of damage identification and calculation. A laser scanning system is built to obtain the 3D point cloud data of the rail surface. In order to extract the damage region of the rail surface, the 3D point cloud data are processed using iterative difference, nearest neighbours search and a data registration algorithm. The curvature of the point cloud data in the damage region is mapped to RGB color information, which can directly reflect the change trend of the curvature of the point cloud data in the damage region. The extracted damage region is divided into three prism elements by a method of triangulation. The volume and mass of a single element are calculated by the method of geometric segmentation. Finally, the total volume and mass of the damage region are obtained by the principle of superposition. The proposed method is applied to several typical injuries and the results are discussed. The experimental results show that the algorithm can identify damage shapes and calculate damage mass with milligram precision, which are useful for evaluating the damage in a further research stage.

Chemical determination of free radical-induced damage to DNA.

PubMed

Dizdaroglu, M

1991-01-01

Free radical-induced damage to DNA in vivo can result in deleterious biological consequences such as the initiation and promotion of cancer. Chemical characterization and quantitation of such DNA damage is essential for an understanding of its biological consequences and cellular repair. Methodologies incorporating the technique of gas chromatography/mass spectrometry (GC/MS) have been developed in recent years for measurement of free radical-induced DNA damage. The use of GC/MS with selected-ion monitoring (SIM) facilitates unequivocal identification and quantitation of a large number of products of all four DNA bases produced in DNA by reactions with hydroxyl radical, hydrated electron, and H atom. Hydroxyl radical-induced DNA-protein cross-links in mammalian chromatin, and products of the sugar moiety in DNA are also unequivocally identified and quantitated. The sensitivity and selectivity of the GC/MS-SIM technique enables the measurement of DNA base products even in isolated mammalian chromatin without the necessity of first isolating DNA, and despite the presence of histones. Recent results reviewed in this article demonstrate the usefulness of the GC/MS technique for chemical determination of free radical-induced DNA damage in DNA as well as in mammalian chromatin under a vast variety of conditions of free radical production.

Identification of characteristic frequencies of damaged railway tracks using field hammer test measurements

NASA Astrophysics Data System (ADS)

Oregui, M.; Li, Z.; Dollevoet, R.

2015-03-01

In this paper, the feasibility of the Frequency Response Function (FRF)-based statistical method to identify the characteristic frequencies of railway track defects is studied. The method compares a damaged track state to a healthy state based on non-destructive field hammer test measurements. First, a study is carried out to investigate the repeatability of hammer tests in railway tracks. By changing the excitation and measurement locations it is shown that the variability introduced by the test process is negligible. Second, following the concepts of control charts employed in process monitoring, a method to define an approximate healthy state is introduced by using hammer test measurements at locations without visual damage. Then, the feasibility study includes an investigation into squats (i.e. a major type of rail surface defect) of varying severity. The identified frequency ranges related to squats agree with those found in an extensively validated vehicle-borne detection system. Therefore, the FRF-based statistical method in combination with the non-destructive hammer test measurements has the potential to be employed to identify the characteristic frequencies of damaged conditions in railway tracks in the frequency range of 300-3000 Hz.

Numerical Simulation of Tension Properties for Al-Cu Alloy Friction Stir-Welded Joints with GTN Damage Model

NASA Astrophysics Data System (ADS)

Sun, Guo-Qin; Sun, Feng-Yang; Cao, Fang-Li; Chen, Shu-Jun; Barkey, Mark E.

2015-11-01

The numerical simulation of tensile fracture behavior on Al-Cu alloy friction stir-welded joint was performed with the Gurson-Tvergaard-Needleman (GTN) damage model. The parameters of the GTN model were studied in each region of the friction stir-welded joint by means of inverse identification. Based on the obtained parameters, the finite element model of the welded joint was built to predict the fracture behavior and tension properties. Good agreement can be found between the numerical and experimental results in the location of the tensile fracture and the mechanical properties.

Structural Damage Identification in Stiffened Plate Fatigue Specimens Using Piezoelectric Active Sensing

DTIC Science & Technology

2011-09-01

isolated AO mode first arrival, recorded at PZT 2, is shown at 3 different fatigue levels. Figure 5. The area under the PSD curve, calculated twice...Structural Damage Identification in Stiffened Plate Fatigue Specimens Using Piezoelectric Active Sensing B. L. GRISSO, G. PARK, L. W. SALVINO...with several challenges including limited performance knowledge of the materials, aluminum sensitization, structural fatigue performance, and

Model-based damage evaluation of layered CFRP structures

NASA Astrophysics Data System (ADS)

Munoz, Rafael; Bochud, Nicolas; Rus, Guillermo; Peralta, Laura; Melchor, Juan; Chiachío, Juan; Chiachío, Manuel; Bond, Leonard J.

2015-03-01

An ultrasonic evaluation technique for damage identification of layered CFRP structures is presented. This approach relies on a model-based estimation procedure that combines experimental data and simulation of ultrasonic damage-propagation interactions. The CFPR structure, a [0/90]4s lay-up, has been tested in an immersion through transmission experiment, where a scan has been performed on a damaged specimen. Most ultrasonic techniques in industrial practice consider only a few features of the received signals, namely, time of flight, amplitude, attenuation, frequency contents, and so forth. In this case, once signals are captured, an algorithm is used to reconstruct the complete signal waveform and extract the unknown damage parameters by means of modeling procedures. A linear version of the data processing has been performed, where only Young modulus has been monitored and, in a second nonlinear version, the first order nonlinear coefficient β was incorporated to test the possibility of detection of early damage. The aforementioned physical simulation models are solved by the Transfer Matrix formalism, which has been extended from linear to nonlinear harmonic generation technique. The damage parameter search strategy is based on minimizing the mismatch between the captured and simulated signals in the time domain in an automated way using Genetic Algorithms. Processing all scanned locations, a C-scan of the parameter of each layer can be reconstructed, obtaining the information describing the state of each layer and each interface. Damage can be located and quantified in terms of changes in the selected parameter with a measurable extension. In the case of the nonlinear coefficient of first order, evidence of higher sensitivity to damage than imaging the linearly estimated Young Modulus is provided.

Visual object agnosia is associated with a breakdown of object-selective responses in the lateral occipital cortex.

PubMed

Ptak, Radek; Lazeyras, François; Di Pietro, Marie; Schnider, Armin; Simon, Stéphane R

2014-07-01

Patients with visual object agnosia fail to recognize the identity of visually presented objects despite preserved semantic knowledge. Object agnosia may result from damage to visual cortex lying close to or overlapping with the lateral occipital complex (LOC), a brain region that exhibits selectivity to the shape of visually presented objects. Despite this anatomical overlap the relationship between shape processing in the LOC and shape representations in object agnosia is unknown. We studied a patient with object agnosia following isolated damage to the left occipito-temporal cortex overlapping with the LOC. The patient showed intact processing of object structure, yet often made identification errors that were mainly based on the global visual similarity between objects. Using functional Magnetic Resonance Imaging (fMRI) we found that the damaged as well as the contralateral, structurally intact right LOC failed to show any object-selective fMRI activity, though the latter retained selectivity for faces. Thus, unilateral damage to the left LOC led to a bilateral breakdown of neural responses to a specific stimulus class (objects and artefacts) while preserving the response to a different stimulus class (faces). These findings indicate that representations of structure necessary for the identification of objects crucially rely on bilateral, distributed coding of shape features. Copyright © 2014 Elsevier Ltd. All rights reserved.

A machine-learning approach for damage detection in aircraft structures using self-powered sensor data

NASA Astrophysics Data System (ADS)

Salehi, Hadi; Das, Saptarshi; Chakrabartty, Shantanu; Biswas, Subir; Burgueño, Rigoberto

2017-04-01

This study proposes a novel strategy for damage identification in aircraft structures. The strategy was evaluated based on the simulation of the binary data generated from self-powered wireless sensors employing a pulse switching architecture. The energy-aware pulse switching communication protocol uses single pulses instead of multi-bit packets for information delivery resulting in discrete binary data. A system employing this energy-efficient technology requires dealing with time-delayed binary data due to the management of power budgets for sensing and communication. This paper presents an intelligent machine-learning framework based on combination of the low-rank matrix decomposition and pattern recognition (PR) methods. Further, data fusion is employed as part of the machine-learning framework to take into account the effect of data time delay on its interpretation. Simulated time-delayed binary data from self-powered sensors was used to determine damage indicator variables. Performance and accuracy of the damage detection strategy was examined and tested for the case of an aircraft horizontal stabilizer. Damage states were simulated on a finite element model by reducing stiffness in a region of the stabilizer's skin. The proposed strategy shows satisfactory performance to identify the presence and location of the damage, even with noisy and incomplete data. It is concluded that PR is a promising machine-learning algorithm for damage detection for time-delayed binary data from novel self-powered wireless sensors.

Nonlinear Lamb waves for fatigue damage identification in FRP-reinforced steel plates.

PubMed

Wang, Yikuan; Guan, Ruiqi; Lu, Ye

2017-09-01

A nonlinear Lamb-wave-based method for fatigue crack detection in steel plates with and without carbon fibre reinforcement polymer (CFRP) reinforcement is presented in this study. Both numerical simulation and experimental evaluation were performed for Lamb wave propagation and its interaction with a fatigue crack on these two steel plate types. With the generation of the second harmonic, the damage-induced wave nonlinearities were identified by surface-bonded piezoelectric sensors. Numerical simulation revealed that the damage-induced wave component at the second harmonic was slightly affected by the existence of CFRP laminate, although the total wave energy was decreased because of wave leakage into the CFRP laminate. Due to unavoidable nonlinearity from the experimental environments, it was impractical to directly extract the time-of-flight of the second harmonic for locating the crack. To this end, the correlation coefficient of benchmark and signal with damage at double frequency in the time domain was calculated, based on which an imaging method was introduced to locate the fatigue crack in steel plates with and without CFRP laminates. Copyright © 2017 Elsevier B.V. All rights reserved.

Nonlinear Dynamic Behavior of Impact Damage in a Composite Skin-Stiffener Structure

NASA Technical Reports Server (NTRS)

Ooijevaar, T. H.; Rogge, M. D.; Loendersloot, R.; Warnet, L.; Akkerman, R.; deBoer, A.

2013-01-01

One of the key issues in composite structures for aircraft applications is the early identification of damage. Often, service induced damage does not involve visible plastic deformation, but internal matrix related damage, like delaminations. A wide range of technologies, comprising global vibration and local wave propagation methods can be employed for health monitoring purposes. Traditional low frequency modal analysis based methods are linear methods. The effectiveness of these methods is often limited since they rely on a stationary and linear approximation of the system. The nonlinear interaction between a low frequency wave field and a local impact induced skin-stiffener failure is experimentally demonstrated in this paper. The different mechanisms that are responsible for the nonlinearities (opening, closing and contact) of the distorted harmonic waveforms are separated with the help of phase portraits. A basic analytical model is employed to support the observations.

Study on Failure of Third-Party Damage for Urban Gas Pipeline Based on Fuzzy Comprehensive Evaluation

PubMed Central

Li, Jun; Zhang, Hong; Han, Yinshan; Wang, Baodong

2016-01-01

Focusing on the diversity, complexity and uncertainty of the third-party damage accident, the failure probability of third-party damage to urban gas pipeline was evaluated on the theory of analytic hierarchy process and fuzzy mathematics. The fault tree of third-party damage containing 56 basic events was built by hazard identification of third-party damage. The fuzzy evaluation of basic event probabilities were conducted by the expert judgment method and using membership function of fuzzy set. The determination of the weight of each expert and the modification of the evaluation opinions were accomplished using the improved analytic hierarchy process, and the failure possibility of the third-party to urban gas pipeline was calculated. Taking gas pipelines of a certain large provincial capital city as an example, the risk assessment structure of the method was proved to conform to the actual situation, which provides the basis for the safety risk prevention. PMID:27875545

Online Damage Detection on Metal and Composite Space Structures by Active and Passive Acoustic Methods

NASA Astrophysics Data System (ADS)

Scheerer, M.; Cardone, T.; Rapisarda, A.; Ottaviano, S.; Ftancesconi, D.

2012-07-01

In the frame of ESA funded programme Future Launcher Preparatory Programme Period 1 “Preparatory Activities on M&S”, Aerospace & Advanced Composites and Thales Alenia Space-Italia, have conceived and tested a structural health monitoring approach based on integrated Acoustic Emission - Active Ultrasound Damage Identification. The monitoring methods implemented in the study are both passive and active methods and the purpose is to cover large areas with a sufficient damage size detection capability. Two representative space sub-structures have been built and tested: a composite overwrapped pressure vessel (COPV) and a curved, stiffened Al-Li panel. In each structure, typical critical damages have been introduced: delaminations caused by impacts in the COPV and a crack in the stiffener of the Al-Li panel which was grown during a fatigue test campaign. The location and severity of both types of damages have been successfully assessed online using two commercially available systems: one 6 channel AE system from Vallen and one 64 channel AU system from Acellent.

Health condition identification of multi-stage planetary gearboxes using a mRVM-based method

NASA Astrophysics Data System (ADS)

Lei, Yaguo; Liu, Zongyao; Wu, Xionghui; Li, Naipeng; Chen, Wu; Lin, Jing

2015-08-01

Multi-stage planetary gearboxes are widely applied in aerospace, automotive and heavy industries. Their key components, such as gears and bearings, can easily suffer from damage due to tough working environment. Health condition identification of planetary gearboxes aims to prevent accidents and save costs. This paper proposes a method based on multiclass relevance vector machine (mRVM) to identify health condition of multi-stage planetary gearboxes. In this method, a mRVM algorithm is adopted as a classifier, and two features, i.e. accumulative amplitudes of carrier orders (AACO) and energy ratio based on difference spectra (ERDS), are used as the input of the classifier to classify different health conditions of multi-stage planetary gearboxes. To test the proposed method, seven health conditions of a two-stage planetary gearbox are considered and vibration data is acquired from the planetary gearbox under different motor speeds and loading conditions. The results of three tests based on different data show that the proposed method obtains an improved identification performance and robustness compared with the existing method.

High spatial resolution imaging for structural health monitoring based on virtual time reversal

NASA Astrophysics Data System (ADS)

Cai, Jian; Shi, Lihua; Yuan, Shenfang; Shao, Zhixue

2011-05-01

Lamb waves are widely used in structural health monitoring (SHM) of plate-like structures. Due to the dispersion effect, Lamb wavepackets will be elongated and the resolution for damage identification will be strongly affected. This effect can be automatically compensated by the time reversal process (TRP). However, the time information of the compensated waves is also removed at the same time. To improve the spatial resolution of Lamb wave detection, virtual time reversal (VTR) is presented in this paper. In VTR, a changing-element excitation and reception mechanism (CERM) rather than the traditional fixed excitation and reception mechanism (FERM) is adopted for time information conservation. Furthermore, the complicated TRP procedure is replaced by simple signal operations which can make savings in the hardware cost for recording and generating the time-reversed Lamb waves. After the effects of VTR for dispersive damage scattered signals are theoretically analyzed, the realization of VTR involving the acquisition of the transfer functions of damage detecting paths under step pulse excitation is discussed. Then, a VTR-based imaging method is developed to improve the spatial resolution of the delay-and-sum imaging with a sparse piezoelectric (PZT) wafer array. Experimental validation indicates that the damage scattered wavepackets of A0 mode in an aluminum plate are partly recompressed and focalized with their time information preserved by VTR. Both the single damage and the dual adjacent damages in the plate can be clearly displayed with high spatial resolution by the proposed VTR-based imaging method.

A neuro-inspired model-based closed-loop neuroprosthesis for the substitution of a cerebellar learning function in anesthetized rats

NASA Astrophysics Data System (ADS)

Hogri, Roni; Bamford, Simeon A.; Taub, Aryeh H.; Magal, Ari; Giudice, Paolo Del; Mintz, Matti

2015-02-01

Neuroprostheses could potentially recover functions lost due to neural damage. Typical neuroprostheses connect an intact brain with the external environment, thus replacing damaged sensory or motor pathways. Recently, closed-loop neuroprostheses, bidirectionally interfaced with the brain, have begun to emerge, offering an opportunity to substitute malfunctioning brain structures. In this proof-of-concept study, we demonstrate a neuro-inspired model-based approach to neuroprostheses. A VLSI chip was designed to implement essential cerebellar synaptic plasticity rules, and was interfaced with cerebellar input and output nuclei in real time, thus reproducing cerebellum-dependent learning in anesthetized rats. Such a model-based approach does not require prior system identification, allowing for de novo experience-based learning in the brain-chip hybrid, with potential clinical advantages and limitations when compared to existing parametric ``black box'' models.

Identification of ATR-Chk1 pathway inhibitors that selectively target p53-deficient cells without directly suppressing ATR catalytic activity

PubMed Central

Kawasumi, Masaoki; Bradner, James E.; Tolliday, Nicola; Thibodeau, Renee; Sloan, Heather; Brummond, Kay M.; Nghiem, Paul

2014-01-01

Resistance to DNA-damaging chemotherapy is a barrier to effective treatment that appears to be augmented by p53 functional deficiency in many cancers. In p53-deficient cells where the G1/S checkpoint is compromised, cell viability after DNA damage relies upon intact intra-S and G2/M checkpoints mediated by the ATR and Chk1 kinases. Thus, a logical rationale to sensitize p53-deficient cancers to DNA-damaging chemotherapy is through the use of ATP-competitive inhibitors of ATR or Chk1. To discover small molecules that may act on uncharacterized components of the ATR pathway, we performed a phenotype-based screen of 9,195 compounds for their ability to inhibit hydroxyurea-induced phosphorylation of Ser345 on Chk1, known to be a critical ATR substrate. This effort led to the identification of four small-molecule compounds, three of which were derived from known bioactive library (anthothecol, dihydrocelastryl, and erysolin) and one of which was a novel synthetic compound termed MARPIN. These compounds all inhibited ATR-selective phosphorylation and sensitized p53-deficient cancer cells to DNA-damaging agents in vitro and in vivo. Notably, these compounds did not inhibit ATR catalytic activity in vitro, unlike typical ATP-competitive inhibitors, but acted in a mechanistically distinct manner to disable ATR-Chk1 function. Our results highlight a set of novel molecular probes to further elucidate druggable mechanisms to improve cancer therapeutic responses produced by DNA-damaging drugs. PMID:25336189

Identification of ATR-Chk1 pathway inhibitors that selectively target p53-deficient cells without directly suppressing ATR catalytic activity.

PubMed

Kawasumi, Masaoki; Bradner, James E; Tolliday, Nicola; Thibodeau, Renee; Sloan, Heather; Brummond, Kay M; Nghiem, Paul

2014-12-15

Resistance to DNA-damaging chemotherapy is a barrier to effective treatment that appears to be augmented by p53 functional deficiency in many cancers. In p53-deficient cells in which the G1-S checkpoint is compromised, cell viability after DNA damage relies upon intact intra-S and G2-M checkpoints mediated by the ATR (ataxia telangiectasia and Rad3 related) and Chk1 kinases. Thus, a logical rationale to sensitize p53-deficient cancers to DNA-damaging chemotherapy is through the use of ATP-competitive inhibitors of ATR or Chk1. To discover small molecules that may act on uncharacterized components of the ATR pathway, we performed a phenotype-based screen of 9,195 compounds for their ability to inhibit hydroxyurea-induced phosphorylation of Ser345 on Chk1, known to be a critical ATR substrate. This effort led to the identification of four small-molecule compounds, three of which were derived from known bioactive library (anthothecol, dihydrocelastryl, and erysolin) and one of which was a novel synthetic compound termed MARPIN. These compounds all inhibited ATR-selective phosphorylation and sensitized p53-deficient cancer cells to DNA-damaging agents in vitro and in vivo. Notably, these compounds did not inhibit ATR catalytic activity in vitro, unlike typical ATP-competitive inhibitors, but acted in a mechanistically distinct manner to disable ATR-Chk1 function. Our results highlight a set of novel molecular probes to further elucidate druggable mechanisms to improve cancer therapeutic responses produced by DNA-damaging drugs. ©2014 American Association for Cancer Research.

Quantification and identification of lightning damage in tropical forests.

PubMed

Yanoviak, Stephen P; Gora, Evan M; Burchfield, Jeffrey M; Bitzer, Phillip M; Detto, Matteo

2017-07-01

Accurate estimates of tree mortality are essential for the development of mechanistic forest dynamics models, and for estimating carbon storage and cycling. However, identifying agents of tree mortality is difficult and imprecise. Although lightning kills thousands of trees each year and is an important agent of mortality in some forests, the frequency and distribution of lightning-caused tree death remain unknown for most forests. Moreover, because all evidence regarding the effects of lightning on trees is necessarily anecdotal and post hoc, rigorous tests of hypotheses regarding the ecological effects of lightning are impossible. We developed a combined electronic sensor/camera-based system for the location and characterization of lightning strikes to the forest canopy in near real time and tested the system in the forest of Barro Colorado Island, Panama. Cameras mounted on towers provided continuous video recordings of the forest canopy that were analyzed to determine the locations of lightning strikes. We used a preliminary version of this system to record and locate 18 lightning strikes to the forest over a 3-year period. Data from field surveys of known lightning strike locations (obtained from the camera system) enabled us to develop a protocol for reliable, ground-based identification of suspected lightning damage to tropical trees. In all cases, lightning damage was relatively inconspicuous; it would have been overlooked by ground-based observers having no knowledge of the event. We identified three types of evidence that can be used to consistently identify lightning strike damage in tropical forests: (1) localized and directionally biased branch mortality associated with flashover among tree and sapling crowns, (2) mortality of lianas or saplings near lianas, and (3) scorched or wilting epiphytic and hemiepiphytic plants. The longitudinal trunk scars that are typical of lightning-damaged temperate trees were never observed in this study. Given the prevalence of communications towers worldwide, the lightning detection system described here could be implemented in diverse forest types. Data from multiple systems would provide an outstanding opportunity for comparative research on the ecological effects of lightning. Such comparative data are increasingly important given expected increases in lightning frequency with climatic change.

DNA-based identification of Armillaria isolates from peach [Prunus persica (l.) batsch] orchards in méxico state, Mexico

Treesearch

Ruben D. Elias-Roman; Ned B. Klopfenstein; Mee-Sook Kim; Dionicio Alvarado-Rosales; John W. Hanna; Amy L. Ross-Davis; Remigio Anastacio Guzman-Plazola; Guillermo Calderon-Zavala; Antonio Mora-Aguilera

2013-01-01

A collaborative project between the Programa de Fitopatología, Colegio de Postgraduados, Texcoco, Edo. de México and the USDA Forest Service-RMRS, Moscow Forest Pathology Laboratory began in 2011 to identify which species of Armillaria are causing widespread and severe damage to the peach orchards from México State, México. We are employing a DNA-based approach in...

Selection of regularization parameter for l1-regularized damage detection

NASA Astrophysics Data System (ADS)

Hou, Rongrong; Xia, Yong; Bao, Yuequan; Zhou, Xiaoqing

2018-06-01

The l1 regularization technique has been developed for structural health monitoring and damage detection through employing the sparsity condition of structural damage. The regularization parameter, which controls the trade-off between data fidelity and solution size of the regularization problem, exerts a crucial effect on the solution. However, the l1 regularization problem has no closed-form solution, and the regularization parameter is usually selected by experience. This study proposes two strategies of selecting the regularization parameter for the l1-regularized damage detection problem. The first method utilizes the residual and solution norms of the optimization problem and ensures that they are both small. The other method is based on the discrepancy principle, which requires that the variance of the discrepancy between the calculated and measured responses is close to the variance of the measurement noise. The two methods are applied to a cantilever beam and a three-story frame. A range of the regularization parameter, rather than one single value, can be determined. When the regularization parameter in this range is selected, the damage can be accurately identified even for multiple damage scenarios. This range also indicates the sensitivity degree of the damage identification problem to the regularization parameter.

Detection of damage in welded structure using experimental modal data

NASA Astrophysics Data System (ADS)

Abu Husain, N.; Ouyang, H.

2011-07-01

A typical automotive structure could contain thousands of spot weld joints that contribute significantly to the vehicle's structural stiffness and dynamic characteristics. However, some of these joints may be imperfect or even absent during the manufacturing process and they are also highly susceptible to damage due to operational and environmental conditions during the vehicle lifetime. Therefore, early detection and estimation of damage are important so necessary actions can be taken to avoid further problems. Changes in physical parameters due to existence of damage in a structure often leads to alteration of vibration modes; thus demonstrating the dependency between the vibration characteristics and the physical properties of structures. A sensitivity-based model updating method, performed using a combination of MATLAB and NASTRAN, has been selected for the purpose of this work. The updating procedure is regarded as parameter identification which aims to bring the numerical prediction to be as closely as possible to the measured natural frequencies and mode shapes data of the damaged structure in order to identify the damage parameters (characterised by the reductions in the Young's modulus of the weld patches to indicate the loss of material/stiffness at the damage region).

Taphonomic Analysis of Rodentia and Lagomorpha Bone Gnawing Based Upon Incisor Size.

PubMed

Pokines, James T; Sussman, Rachel; Gough, Megan; Ralston, Claira; McLeod, Elizabeth; Brun, Karen; Kearns, Aisling; Moore, Tara L

2017-01-01

Rodent and lagomorph species have a worldwide distribution and have the potential to alter remains from forensic cases by gnawing soft tissue and bones and through dispersal. The present research compiled metric data on the incisors widths of all rodent and lagomorph species whose ranges include Massachusetts, U.S.A., to compare their sizes to gnawing damage found on 17 cases of human remains from the Office of the Chief Medical Examiner, Boston, MA. Data on gnawing maximum striation widths also were collected from live laboratory, zoo, and wild specimens. Gnawing damage on the forensic cases could be attributed only to a particular size class of rodent or lagomorph, and identification to a particular species based on gnawing damage alone may be possible only in relatively rare cases. Multiple species examined here have broad distribution ranges, so their taphonomic alterations may impact bones from forensic cases throughout large portions of North America. © 2016 American Academy of Forensic Sciences.

Fatigue and damage tolerance scatter models

NASA Astrophysics Data System (ADS)

Raikher, Veniamin L.

1994-09-01

Effective Total Fatigue Life and Crack Growth Scatter Models are proposed. The first of them is based on the power form of the Wohler curve, fatigue scatter dependence on mean life value, cycle stress ratio influence on fatigue scatter, and validated description of the mean stress influence on the mean fatigue life. The second uses in addition are fracture mechanics approach, assumption of initial damage existence, and Paris equation. Simple formulas are derived for configurations of models. A preliminary identification of the parameters of the models is fulfilled on the basis of experimental data. Some new and important results for fatigue and crack growth scatter characteristics are obtained.

The development of damage identification methods for buildings with image recognition and machine learning techniques utilizing aerial photographs of the 2016 Kumamoto earthquake

NASA Astrophysics Data System (ADS)

Shohei, N.; Nakamura, H.; Fujiwara, H.; Naoichi, M.; Hiromitsu, T.

2017-12-01

It is important to get schematic information of the damage situation immediately after the earthquake utilizing photographs shot from an airplane in terms of the investigation and the decision-making for authorities. In case of the 2016 Kumamoto earthquake, we have acquired more than 1,800 orthographic projection photographs adjacent to damaged areas. These photos have taken between April 16th and 19th by airplanes, then we have distinguished damages of all buildings with 4 levels, and organized as approximately 296,000 GIS data corresponding to the fundamental Geospatial data published by Geospatial Information Authority of Japan. These data have organized by effort of hundreds of engineers. However, it is not considered practical for more extensive disasters like the Nankai Trough earthquake by only human powers. So, we have been developing the automatic damage identification method utilizing image recognition and machine learning techniques. First, we have extracted training data of more than 10,000 buildings which have equally damage levels divided in 4 grades. With these training data, we have been raster scanning in each scanning ranges of entire images, then clipping patch images which represents damage levels each. By utilizing these patch images, we have been developing discriminant models by two ways. One is a model using the Support Vector Machine (SVM). First, extract a feature quantity of each patch images. Then, with these vector values, calculate the histogram density as a method of Bag of Visual Words (BoVW), then classify borders with each damage grades by SVM. The other one is a model using the multi-layered Neural Network. First, design a multi-layered Neural Network. Second, input patch images and damage levels based on a visual judgement, and then, optimize learning parameters with error backpropagation method. By use of both discriminant models, we are going to discriminate damage levels in each patches, then create the image that shows building damage situations. It would be helpful for more prompt and widespread damage detection than visual judgement. Acknowledgment: This work was supported by CSTI through the Cross-ministerial Strategic Innovation Promotion Program (SIP), titled "Enhancement of societal resiliency against natural disasters"(Funding agency: JST).

Incorporation of Radio Frequency Identification Tag in Dentures to Facilitate Recognition and Forensic Human Identification

PubMed Central

Nuzzolese, E; Marcario, V; Di Vella, G

2010-01-01

Forensic identification using odontology is based on the comparison of ante-mortem and post mortem dental records. The insertion of a radio frequency identification (RFId) tag into dentures could be used as an aid to identify decomposed bodies, by storing personal identification data in a small transponder that can be radio-transmitted to a reader connected to a computer. A small passive, 12 x 2,1 mm, read-only RFId-tag was incorporated into the manufacture of three trial complete upper dentures and tested for a signal. The aim of this article is to demonstrate the feasibility of manufacturing such a dental prosthesis, the technical protocols for its implantation in the denture resin and its working principles. Future research and tests are required in order to verify human compatibility of the tagged denture and also to evaluate any potential deterioration in strength when subjected to high temperatures, or for damage resulting from everyday wear and tear. It should also be able to withstand the extreme conditions resulting from major accidents or mass disasters and procedures used to perform a forensic identification. PMID:20657641

Automatic pattern identification of rock moisture based on the Staff-RF model

NASA Astrophysics Data System (ADS)

Zheng, Wei; Tao, Kai; Jiang, Wei

2018-04-01

Studies on the moisture and damage state of rocks generally focus on the qualitative description and mechanical information of rocks. This method is not applicable to the real-time safety monitoring of rock mass. In this study, a musical staff computing model is used to quantify the acoustic emission signals of rocks with different moisture patterns. Then, the random forest (RF) method is adopted to form the staff-RF model for the real-time pattern identification of rock moisture. The entire process requires only the computing information of the AE signal and does not require the mechanical conditions of rocks.

Development of a high-throughput screening system for identification of novel reagents regulating DNA damage in human dermal fibroblasts.

PubMed

Bae, Seunghee; An, In-Sook; An, Sungkwan

2015-09-01

Ultraviolet (UV) radiation is a major inducer of skin aging and accumulated exposure to UV radiation increases DNA damage in skin cells, including dermal fibroblasts. In the present study, we developed a novel DNA repair regulating material discovery (DREAM) system for the high-throughput screening and identification of putative materials regulating DNA repair in skin cells. First, we established a modified lentivirus expressing the luciferase and hypoxanthine phosphoribosyl transferase (HPRT) genes. Then, human dermal fibroblast WS-1 cells were infected with the modified lentivirus and selected with puromycin to establish cells that stably expressed luciferase and HPRT (DREAM-F cells). The first step in the DREAM protocol was a 96-well-based screening procedure, involving the analysis of cell viability and luciferase activity after pretreatment of DREAM-F cells with reagents of interest and post-treatment with UVB radiation, and vice versa. In the second step, we validated certain effective reagents identified in the first step by analyzing the cell cycle, evaluating cell death, and performing HPRT-DNA sequencing in DREAM-F cells treated with these reagents and UVB. This DREAM system is scalable and forms a time-saving high-throughput screening system for identifying novel anti-photoaging reagents regulating DNA damage in dermal fibroblasts.

Real-time sensing of fatigue crack damage for information-based decision and control

NASA Astrophysics Data System (ADS)

Keller, Eric Evans

Information-based decision and control for structures that are subject to failure by fatigue cracking is based on the following notion: Maintenance, usage scheduling, and control parameter tuning can be optimized through real time knowledge of the current state of fatigue crack damage. Additionally, if the material properties of a mechanical structure can be identified within a smaller range, then the remaining life prediction of that structure will be substantially more accurate. Information-based decision systems can rely one physical models, estimation of material properties, exact knowledge of usage history, and sensor data to synthesize an accurate snapshot of the current state of damage and the likely remaining life of a structure under given assumed loading. The work outlined in this thesis is structured to enhance the development of information-based decision and control systems. This is achieved by constructing a test facility for laboratory experiments on real-time damage sensing. This test facility makes use of a methodology that has been formulated for fatigue crack model parameter estimation and significantly improves the quality of predictions of remaining life. Specifically, the thesis focuses on development of an on-line fatigue crack damage sensing and life prediction system that is built upon the disciplines of Systems Sciences and Mechanics of Materials. A major part of the research effort has been expended to design and fabricate a test apparatus which allows: (i) measurement and recording of statistical data for fatigue crack growth in metallic materials via different sensing techniques; and (ii) identification of stochastic model parameters for prediction of fatigue crack damage. To this end, this thesis describes the test apparatus and the associated instrumentation based on four different sensing techniques, namely, traveling optical microscopy, ultrasonic flaw detection, Alternating Current Potential Drop (ACPD), and fiber-optic extensometry-based compliance, for crack length measurements.

Integrated smart structures wingbox

NASA Astrophysics Data System (ADS)

Simon, Solomon H.

1993-09-01

One objective of smart structures development is to demonstrate the ability of a mechanical component to monitor its own structural integrity and health. Achievement of this objective requires the integration of different technologies, i.e.: (1) structures, (2) sensors, and (3) artificial intelligence. We coordinated a team of experts from these three fields. These experts used reliable knowledge towards the forefront of their technologies and combined the appropriate features into an integrated hardware/software smart structures wingbox (SSW) test article. A 1/4 in. hole was drilled into the SSW test article. Although the smart structure had never seen damage of this type, it correctly recognized and located the damage. Based on a knowledge-based simulation, quantification and assessment were also carried out. We have demonstrated that the SSW integrated hardware & software test article can perform six related functions: (1) identification of a defect; (2) location of the defect; (3) quantification of the amount of damage; (4) assessment of performance degradation; (5) continued monitoring in spite of damage; and (6) continuous recording of integrity data. We present the successful results of the integrated test article in this paper, along with plans for future development and deployment of the technology.

Structural health monitoring using a hybrid network of self-powered accelerometer and strain sensors

NASA Astrophysics Data System (ADS)

Alavi, Amir H.; Hasni, Hassene; Jiao, Pengcheng; Lajnef, Nizar

2017-04-01

This paper presents a structural damage identification approach based on the analysis of the data from a hybrid network of self-powered accelerometer and strain sensors. Numerical and experimental studies are conducted on a plate with bolted connections to verify the method. Piezoelectric ceramic Lead Zirconate Titanate (PZT)-5A ceramic discs and PZT-5H bimorph accelerometers are placed on the surface of the plate to measure the voltage changes due to damage progression. Damage is defined by loosening or removing one bolt at a time from the plate. The results show that the PZT accelerometers provide a fairly more consistent behavior than the PZT strain sensors. While some of the PZT strain sensors are not sensitive to the changes of the boundary condition, the bimorph accelerometers capture the mode changes from undamaged to missing bolt conditions. The results corresponding to the strain sensors are better indicator to the location of damage compared to the accelerometers. The characteristics of the overall structure can be monitored with even one accelerometer. On the other hand, several PZT strain sensors might be needed to localize the damage.

Earthquake Damage Assessment Using Very High Resolution Satelliteimagery

NASA Astrophysics Data System (ADS)

Chiroiu, L.; André, G.; Bahoken, F.; Guillande, R.

Various studies using satellite imagery were applied in the last years in order to assess natural hazard damages, most of them analyzing the case of floods, hurricanes or landslides. For the case of earthquakes, the medium or small spatial resolution data available in the recent past did not allow a reliable identification of damages, due to the size of the elements (e.g. buildings or other structures), too small compared with the pixel size. The recent progresses of remote sensing in terms of spatial resolution and data processing makes possible a reliable damage detection to the elements at risk. Remote sensing techniques applied to IKONOS (1 meter resolution) and IRS (5 meters resolution) imagery were used in order to evaluate seismic vulnerability and post earthquake damages. A fast estimation of losses was performed using a multidisciplinary approach based on earthquake engineering and geospatial analysis. The results, integrated into a GIS database, could be transferred via satellite networks to the rescue teams deployed on the affected zone, in order to better coordinate the emergency operations. The methodology was applied to the city of Bhuj and Anjar after the 2001 Gujarat (India) Earthquake.

Combined meso-scale modeling and experimental investigation of the effect of mechanical damage on the transport properties of cementitious composites

NASA Astrophysics Data System (ADS)

Raghavan, Balaji; Niknezhad, Davood; Bernard, Fabrice; Kamali-Bernard, Siham

2016-09-01

The transport properties of cementitious composites such as concrete are important indicators of their durability, and are known to be heavily influenced by mechanical loading. In the current work, we use meso-scale hygro-mechanical modeling with a morphological 3D two phase mortar-aggregate model, in conjunction with experimentally obtained properties, to investigate the coupling between mechanical loading and damage and the permeability of the composite. The increase in permeability of a cylindrical test specimen at 28% aggregate fraction during a uniaxial displacement-controlled compression test at 85% of the peak load was measured using a gas permeameter. The mortar's mechanical behavior is assumed to follow the well-known compression damaged plasticity (CDP) model with isotropic damage, at varying thresholds, and obtained from different envelope curves. The damaged intrinsic permeability of the mortar evolves according to a logarithmic matching law with progressive loading. We fit the matching law parameters to the experimental result for the test specimen by inverse identification using our meso-scale model. We then subject a series of virtual composite specimens to quasi-static uniaxial compressive loading with varying boundary conditions to obtain the simulated damage and strain evolutions, and use the damage data and the previously identified parameters to determine the evolution of the macroscopic permeability tensor for the specimens, using a network model. We conduct a full parameter study by varying aggregate volume fraction, granulometric distribution, loading/boundary conditions and "matching law" parameters, as well as for different strain-damage thresholds and uniaxial loading envelope curves. Based on this study, we propose Avrami equation-based upper and lower bounds for the evolution of the damaged permeability of the composite.

Skin protection against UVA-induced iron damage by multiantioxidants and iron chelating drugs/prodrugs.

PubMed

Reelfs, Olivier; Eggleston, Ian M; Pourzand, Charareh

2010-03-01

In humans, prolonged sunlight exposure is associated with various pathological states. The continuing drive to develop improved skin protection involves not only approaches to reduce DNA damage by solar ultraviolet B (UVB) but also the development of methodologies to provide protection against ultraviolet A (UVA), the oxidising component of sunlight. Furthermore identification of specific cellular events following ultraviolet (UV) irradiation is likely to provide clues as to the mechanism of the development of resulting pathologies and therefore strategies for protection. Our discovery that UVA radiation, leads to an immediate measurable increase in 'labile' iron in human skin fibroblasts and keratinocytes provides a new insight into UVA-induced skin damage, since iron is a catalyst of biological oxidations. The main purpose of this overview is to bring together some of the new findings related to mechanisms underlying UVA-induced iron release and to discuss novel approaches based on the use of multiantioxidants and light-activated caged-iron chelators for efficient protection of skin cells against UVA-induced iron damage.

Critical and subcritical damage monitoring of bonded composite repairs using innovative non-destructive techniques

NASA Astrophysics Data System (ADS)

Grammatikos, S. A.; Kordatos, E. Z.; Aggelis, D. G.; Matikas, T. E.; Paipetis, A. S.

2012-04-01

Infrared Thermography (IrT) has been shown to be capable of detecting and monitoring service induced damage of repair composite structures. Full-field imaging, along with portability are the primary benefits of the thermographic technique. On-line lock-in thermography has been reported to successfully monitor damage propagation or/and stress concentration in composite coupons, as mechanical stresses in structures induce heat concentration phenomena around flaws. During mechanical fatigue, cyclic loading plays the role of the heating source and this allows for critical and subcritical damage identification and monitoring using thermography. The Electrical Potential Change Technique (EPCT) is a new method for damage identification and monitoring during loading. The measurement of electrical potential changes at specific points of Carbon Fiber Reinforced Polymers (CFRPs) under load are reported to enable the monitoring of strain or/and damage accumulation. Along with the aforementioned techniques Finally, Acoustic Emission (AE) method is well known to provide information about the location and type of damage. Damage accumulation due to cyclic loading imposes differentiation of certain parameters of AE like duration and energy. Within the scope of this study, infrared thermography is employed along with AE and EPCT methods in order to assess the integrity of bonded repair patches on composite substrates and to monitor critical and subcritical damage induced by the mechanical loading. The combined methodologies were effective in identifying damage initiation and propagation of bonded composite repairs.

Influence of Different Yield Loci on Failure Prediction with Damage Models

NASA Astrophysics Data System (ADS)

Heibel, S.; Nester, W.; Clausmeyer, T.; Tekkaya, A. E.

2017-09-01

Advanced high strength steels are widely used in the automotive industry to simultaneously improve crash performance and reduce the car body weight. A drawback of these multiphase steels is their sensitivity to damage effects and thus the reduction of ductility. For that reason the Forming Limit Curve is only partially suitable for this class of steels. An improvement in failure prediction can be obtained by using damage mechanics. The objective of this paper is to comparatively review the phenomenological damage model GISSMO and the Enhanced Lemaitre Damage Model. GISSMO is combined with three different yield loci, namely von Mises, Hill48 and Barlat2000 to investigate the influence of the choice of the plasticity description on damage modelling. The Enhanced Lemaitre Model is used with Hill48. An inverse parameter identification strategy for a DP1000 based on stress-strain curves and optical strain measurements of shear, uniaxial, notch and (equi-)biaxial tension tests is applied to calibrate the models. A strong dependency of fracture strains on the choice of yield locus can be observed. The identified models are validated on a cross-die cup showing ductile fracture with slight necking.

Immunity-based detection, identification, and evaluation of aircraft sub-system failures

NASA Astrophysics Data System (ADS)

Moncayo, Hever Y.

This thesis describes the design, development, and flight-simulation testing of an integrated Artificial Immune System (AIS) for detection, identification, and evaluation of a wide variety of sensor, actuator, propulsion, and structural failures/damages including the prediction of the achievable states and other limitations on performance and handling qualities. The AIS scheme achieves high detection rate and low number of false alarms for all the failure categories considered. Data collected using a motion-based flight simulator are used to define the self for an extended sub-region of the flight envelope. The NASA IFCS F-15 research aircraft model is used and represents a supersonic fighter which include model following adaptive control laws based on non-linear dynamic inversion and artificial neural network augmentation. The flight simulation tests are designed to analyze and demonstrate the performance of the immunity-based aircraft failure detection, identification and evaluation (FDIE) scheme. A general robustness analysis is also presented by determining the achievable limits for a desired performance in the presence of atmospheric perturbations. For the purpose of this work, the integrated AIS scheme is implemented based on three main components. The first component performs the detection when one of the considered failures is present in the system. The second component consists in the identification of the failure category and the classification according to the failed element. During the third phase a general evaluation of the failure is performed with the estimation of the magnitude/severity of the failure and the prediction of its effect on reducing the flight envelope of the aircraft system. Solutions and alternatives to specific design issues of the AIS scheme, such as data clustering and empty space optimization, data fusion and duplication removal, definition of features, dimensionality reduction, and selection of cluster/detector shape are also analyzed in this thesis. They showed to have an important effect on detection performance and are a critical aspect when designing the configuration of the AIS. The results presented in this thesis show that the AIS paradigm addresses directly the complexity and multi-dimensionality associated with a damaged aircraft dynamic response and provides the tools necessary for a comprehensive/integrated solution to the FDIE problem. Excellent detection, identification, and evaluation performance has been recorded for all types of failures considered. The implementation of the proposed AIS-based scheme can potentially have a significant impact on the safety of aircraft operation. The output information obtained from the scheme will be useful to increase pilot situational awareness and determine automated compensation.

Identification of cracks in thick beams with a cracked beam element model

NASA Astrophysics Data System (ADS)

Hou, Chuanchuan; Lu, Yong

2016-12-01

The effect of a crack on the vibration of a beam is a classical problem, and various models have been proposed, ranging from the basic stiffness reduction method to the more sophisticated model involving formulation based on the additional flexibility due to a crack. However, in the damage identification or finite element model updating applications, it is still common practice to employ a simple stiffness reduction factor to represent a crack in the identification process, whereas the use of a more realistic crack model is rather limited. In this paper, the issues with the simple stiffness reduction method, particularly concerning thick beams, are highlighted along with a review of several other crack models. A robust finite element model updating procedure is then presented for the detection of cracks in beams. The description of the crack parameters is based on the cracked beam flexibility formulated by means of the fracture mechanics, and it takes into consideration of shear deformation and coupling between translational and longitudinal vibrations, and thus is particularly suitable for thick beams. The identification procedure employs a global searching technique using Genetic Algorithms, and there is no restriction on the location, severity and the number of cracks to be identified. The procedure is verified to yield satisfactory identification for practically any configurations of cracks in a beam.

Damage Identification in Beam Structure using Spatial Continuous Wavelet Transform

NASA Astrophysics Data System (ADS)

Janeliukstis, R.; Rucevskis, S.; Wesolowski, M.; Kovalovs, A.; Chate, A.

2015-11-01

In this paper the applicability of spatial continuous wavelet transform (CWT) technique for damage identification in the beam structure is analyzed by application of different types of wavelet functions and scaling factors. The proposed method uses exclusively mode shape data from the damaged structure. To examine limitations of the method and to ascertain its sensitivity to noisy experimental data, several sets of simulated data are analyzed. Simulated test cases include numerical mode shapes corrupted by different levels of random noise as well as mode shapes with different number of measurement points used for wavelet transform. A broad comparison of ability of different wavelet functions to detect and locate damage in beam structure is given. Effectiveness and robustness of the proposed algorithms are demonstrated experimentally on two aluminum beams containing single mill-cut damage. The modal frequencies and the corresponding mode shapes are obtained via finite element models for numerical simulations and by using a scanning laser vibrometer with PZT actuator as vibration excitation source for the experimental study.

Damage identification of beam structures using free response shapes obtained by use of a continuously scanning laser Doppler vibrometer system

NASA Astrophysics Data System (ADS)

Xu, Y. F.; Chen, Da-Ming; Zhu, W. D.

2017-08-01

Spatially dense operating deflection shapes and mode shapes can be rapidly obtained by use of a continuously scanning laser Doppler vibrometer (CSLDV) system, which sweeps its laser spot over a vibrating structure surface. This paper introduces a new type of vibration shapes called a free response shape (FRS) that can be obtained by use of a CSLDV system, and a new damage identification methodology using FRSs is developed for beam structures. An analytical expression of FRSs of a damped beam structure is derived, and FRSs from the analytical expression compare well with those from a finite element model. In the damage identification methodology, a free-response damage index (FRDI) is proposed, and damage regions can be identified near neighborhoods with consistently high values of FRDIs associated with different modes; an auxiliary FRDI is defined to assist identification of the neighborhoods. A FRDI associated with a mode consists of differences between curvatures of FRSs associated with the mode in a number of half-scan periods of a CSLDV system and those from polynomials that fit the FRSs with properly determined orders. A convergence index is proposed to determine the proper order of a polynomial fit. One advantage of the methodology is that the FRDI does not require any baseline information of an undamaged beam structure, if it is geometrically smooth and made of materials that have no stiffness and mass discontinuities. Another advantage is that FRDIs associated with multiple modes can be obtained using free response of a beam structure measured by a CSLDV system in one scan. The number of half-scan periods for calculation of the FRDI associated with a mode can be determined by use of the short-time Fourier transform. The proposed methodology was numerically and experimentally applied to identify damage in beam structures; effects of the scan frequency of a CSLDV system on qualities of obtained FRSs were experimentally investigated.

Monitoring and evaluating civil structures using measured vibration

NASA Astrophysics Data System (ADS)

Straser, Erik G.; Kiremidjian, Anne S.

1996-04-01

The need for a rapid assessment of the state of critical and conventional civil structures, such as bridges, control centers, airports, and hospitals, among many, has been amply demonstrated during recent natural disasters. Research is underway at Stanford University to develop a state-of-the-art automated damage monitoring system for long term and extreme event monitoring based on both ambient and forced response measurements. Such research requires a multi-disciplinary approach harnessing the talents and expertise of civil, electrical, and mechanical engineering to arrive at a novel hardware and software solution. Recent advances in silicon micro-machining and microprocessor design allow for the economical integration of sensing, processing, and communication components. Coupling these technological advances with parameter identification algorithms allows for the realization of extreme event damage monitoring systems for civil structures. This paper addresses the first steps toward the development of a near real-time damage diagnostic and monitoring system based on structural response to extreme events. Specifically, micro-electro-mechanical- structures (MEMS) and microcontroller embedded systems (MES) are demonstrated to be an effective platform for the measurement and analysis of civil structures. Experimental laboratory tests with small scale model specimens and a preliminary sensor module are used to evaluate hardware and obtain structural response data from input accelerograms. A multi-step analysis procedure employing ordinary least squares (OLS), extended Kalman filtering (EKF), and a substructuring approach is conducted to extract system characteristics of the model. Results from experimental tests and system identification (SI) procedures as well as fundamental system design issues are presented.

Base Excision Repair Variants in Cancer

PubMed Central

Marsden, Carolyn G.; Dragon, Julie A.; Wallace, Susan S.; Sweasy, Joann B.

2018-01-01

Base excision repair (BER) is a key genome maintenance pathway that removes endogenously damaged DNA bases that arise in cells at very high levels on a daily basis. Failure to remove these damaged DNA bases leads to increased levels of mutagenesis and chromosomal instability, which have the potential to drive carcinogenesis. Next Generation sequencing efforts of the germline and tumors genomes of thousands of individuals has uncovered many rare mutations in BER genes. Given that BER is critical for genome maintenance, it is important to determine whether BER genomic variants have functional phenotypes. In this chapter we present our in silico methods for the identification and prioritization of BER variants for further study. We also provide detailed instructions and commentary on the initial cellular assays we employ to dissect potentially important phenotypes of human BER variants and highlight the strengths and weaknesses of our approaches. BER variants possessing interesting functional phenotypes can then be studied in more detail to provide important mechanistic insights regarding the role of aberrant BER in carcinogenesis. PMID:28645367

Identification of a rhodium(iii) complex as a Wee1 inhibitor against TP53-mutated triple-negative breast cancer cells.

PubMed

Yang, Guan-Jun; Zhong, Hai-Jing; Ko, Chung-Nga; Wong, Suk-Yu; Vellaisamy, Kasipandi; Ye, Min; Ma, Dik-Lung; Leung, Chung-Hang

2018-03-06

The rhodium(iii) complex 1 was identified as a potent Wee1 inhibitor in vitro and in cellulo. It decreased Wee1 activity and unscheduled mitotic entry, and induced cell damage and death in TP53-mutated triple-negative breast cancer cells. 1 represents a promising scaffold for further development of more potent metal-based Wee1 antagonists.

Diffuse reflectance spectroscopy for optical nerve identification. Preliminary ex vivo results for feedback controlled oral and maxillofacial laser surgery

NASA Astrophysics Data System (ADS)

Stelzle, Florian; Zam, Azhar; Adler, Werner; Douplik, Alexandre; Tangermann-Gerk, Katja; Nkenke, Emeka; Neukam, Friedrich Wilhelm; Schmidt, Michael

Objective: Laser surgery has many advantages. However, due to a lack of haptic feedback it is accompanied by the risk of iatrogenic nerve damage. The aim of this study was to evaluate the possibilities of optical nerve identification by diffuse reflectance spectroscopy to set the base for a feedback control system to enhance nerve preservation in oral and maxillofacial laser surgery. Materials and Methods: Diffuse reflectance spectra of nerve tissue, skin, mucosa, fat tissue, muscle, cartilage and bone (15120 spectra) of ex vivo pig heads were acquired in the wavelength range of 350-650 nm. Tissue differentiation was performed by principal components analysis (PCA) followed by linear discriminant analysis (LDA). Specificity and sensitivity were calculated by receiver operating characteristic (ROC) analysis and the area under curve (AUC). Results: Nerve tissue could correctly be identified and differed from skin, mucosa, fat tissue, muscle, cartilage and bone in more than 90% of the cases (AUC results) with a specificity of over 78% and a sensitivity of more than 86%. Conclusion: Nerve tissue can be identified by diffuse reflectance spectroscopy with high precision and reliability. The results may set the base for a feedback system to prevent iatrogenic nerve damage performing oral and maxillofacial laser surgery.

Modeling damage evolution in a hybrid ceramic matrix composite under static tensile load

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonora, N.; Newaz, G.

In this investigation, damage evolution in a unidirectional hybrid ceramic composite made from Nicalon and SiC fibers in a Lithium Aluminosilicate (LAS) glass matrix was studied. The static stress-strain response of the composite exhibited a linear response followed by load drop in a progressive manner. Careful experiments were conducted stopping the tests at various strain levels and using replication technique, scanning and optical microscopy to monitor the evolution of damage in these composites. It was observed that the constituents of the composite failed in a sequential manner at increasing strain levels. The matrix cracks were followed by SiC fiber failuresmore » near ultimate tensile stress. After that, the load drop was associated with progressive failure of the Nicalon fibers. Identification of these failure modes were critical to the development of a concentric cylinder model representing all three constituent phases to predict the constitutive response of the CMC computationally. The strain-to-failure of the matrix and fibers were used to progressively fail the constituents in the model and the overall experimental constitutive response of the CMC was recovered. A strain based analytical representation was developed relating stiffness loss to applied strain. Based on this formulation, damage evolution and its consequence on tensile stress-strain response was predicted for room temperature behavior of hybrid CMCs. The contribution of the current work is that the proposed strain-damage phenomenological model can capture the damage evolution and the corresponding material response for continuous fiber-reinforced CMCs. The modeling approach shows much promise for the complex damage processes observed in hybrid CMCs.« less

Dust Storm Feature Identification and Tracking from 4D Simulation Data

NASA Astrophysics Data System (ADS)

Yu, M.; Yang, C. P.

2016-12-01

Dust storms cause significant damage to health, property and the environment worldwide every year. To help mitigate the damage, dust forecasting models simulate and predict upcoming dust events, providing valuable information to scientists, decision makers, and the public. Normally, the model simulations are conducted in four-dimensions (i.e., latitude, longitude, elevation and time) and represent three-dimensional (3D), spatial heterogeneous features of the storm and its evolution over space and time. This research investigates and proposes an automatic multi-threshold, region-growing based identification algorithm to identify critical dust storm features, and track the evolution process of dust storm events through space and time. In addition, a spatiotemporal data model is proposed, which can support the characterization and representation of dust storm events and their dynamic patterns. Quantitative and qualitative evaluations for the algorithm are conducted to test the sensitivity, and capability of identify and track dust storm events. This study has the potential to assist a better early warning system for decision-makers and the public, thus making hazard mitigation plans more effective.

An intelligent signal processing and pattern recognition technique for defect identification using an active sensor network

NASA Astrophysics Data System (ADS)

Su, Zhongqing; Ye, Lin

2004-08-01

The practical utilization of elastic waves, e.g. Rayleigh-Lamb waves, in high-performance structural health monitoring techniques is somewhat impeded due to the complicated wave dispersion phenomena, the existence of multiple wave modes, the high susceptibility to diverse interferences, the bulky sampled data and the difficulty in signal interpretation. An intelligent signal processing and pattern recognition (ISPPR) approach using the wavelet transform and artificial neural network algorithms was developed; this was actualized in a signal processing package (SPP). The ISPPR technique comprehensively functions as signal filtration, data compression, characteristic extraction, information mapping and pattern recognition, capable of extracting essential yet concise features from acquired raw wave signals and further assisting in structural health evaluation. For validation, the SPP was applied to the prediction of crack growth in an alloy structural beam and construction of a damage parameter database for defect identification in CF/EP composite structures. It was clearly apparent that the elastic wave propagation-based damage assessment could be dramatically streamlined by introduction of the ISPPR technique.

Identification of Antipathogenic Bacterial Coral Symbionts Against Porites Ulcerative White Spots Disease

NASA Astrophysics Data System (ADS)

Sa'adah, Nor; Sabdono, Agus; Diah Permata Wijayanti, dan

2018-02-01

Coral reef ecosystems are ecosystems that are vulnerable and susceptible to damage due to the exploitation of ocean resources. One of the factors that cause coral damage is the disease that attacks the coral. Porites Ulcerative White Spots (PUWS) is a coral disease found in Indonesia and attacks the coral genera Porites allegedly caused by pathogenic microbial attacks. The purpose of this study was to identify the symbiotic bacteria on healthy coral that have antipatogenic potency against PUWS. The method used in this research was descriptive explorative. Sampling was done in Kemujan Island, Karimunjawa. Bacteria were isolated from healthy coral and coral affected by PUWS disease. Streak method was used to purify coral bacteria, while overlay and agar diffusion were used to test antipathogenic activity. Bacterial identification was carried out based on polyphasic approach. The results of this study showed that coral bacterial symbionts have antipathogenic activity against PUWS disease. The selected bacteria NM 1.2, NM 1.3 and KPSH 5. NM1.2 were closely related to Pseudoalteromonas piscicida, Pseudoalteromonas flavipulchra and Bacillus flexus, respectively.

Nonlinear dynamics and health monitoring of 6-DOF breathing cracked Jeffcott rotor

NASA Astrophysics Data System (ADS)

Zhao, Jie; DeSmidt, Hans; Yao, Wei

2015-04-01

Jeffcott rotor is employed to study the nonlinear vibration characteristics of breathing cracked rotor system and explore the possibility of further damage identification. This paper is an extension work of prior study based on 4 degree-of-freedom Jeffcott rotor system. With consideration of disk tilting and gyroscopic effect, 6-dof EOM is derived and the crack model is established using SERR (strain energy release rate) in facture mechanics. Same as the prior work, the damaged stiffness matrix is updated by computing the instant crack closure line through Zero Stress Intensity Factor method. The breathing crack area is taken as a variable to analyze the breathing behavior in terms of eccentricity phase and shaft speed. Furthermore, the coupled vibration among lateral, torsional and longitudinal d.o.f is studied under torsional/axial excitation. The final part demonstrates the possibility of using vibration signal of damaged system for the crack diagnosis and health monitoring.

Small-molecule inhibitors of DNA damage-repair pathways: an approach to overcome tumor resistance to alkylating anticancer drugs

PubMed Central

Srinivasan, Ajay; Gold, Barry

2013-01-01

A major challenge in the future development of cancer therapeutics is the identification of biological targets and pathways, and the subsequent design of molecules to combat the drug-resistant cells hiding in virtually all cancers. This therapeutic approach is justified based upon the limited advances in cancer cures over the past 30 years, despite the development of many novel chemotherapies and earlier detection, which often fail due to drug resistance. Among the various targets to overcome tumor resistance are the DNA repair systems that can reverse the cytotoxicity of many clinically used DNA-damaging agents. Some progress has already been made but much remains to be done. We explore some components of the DNA-repair process, which are involved in repair of alkylation damage of DNA, as targets for the development of novel and effective molecules designed to improve the efficacy of existing anticancer drugs. PMID:22709253

Development of Mechanochemically Active Polymers for Early Damage Detection

NASA Astrophysics Data System (ADS)

Zou, Jin

Identification of early damage in polymer composite materials is of significant importance so that preventative measures can be taken before the materials reach catastrophic failure. Scientists have been developing damage detection technologies over many years and recently, mechanophore-based polymers, in which mechanical energy is translated to activate a chemical transformation, have received increasing attention. More specifically, the damage can be made detectable by mechanochromic polymers, which provide a visible color change upon the scission of covalent bonds under stress. This dissertation focuses on the study of a novel self-sensing framework for identifying early and in-situ damage by employing unique stress-sensing mechanophores. Two types of mechanophores, cyclobutane and cyclooctane, were utilized, and the former formed from cinnamoyl moeities and the latter formed from anthracene upon photodimerization. The effects on the thermal and mechanical properties with the addition of the cyclobutane-based polymers into epoxy matrices were investigated. The emergence of cracks was detected by fluorescent signals at a strain level right after the yield point of the polymer blends, and the fluorescence intensified with the accumulation of strain. Similar to the mechanism of fluorescence emission from the cleavage of cyclobutane, the cyclooctane moiety generated fluorescent emission with a higher quantum yield upon cleavage. The experimental results also demonstrated the success of employing the cyclooctane type mechanophore as a potential force sensor, as the fluorescence intensification was correlated with the strain increase.

Model correlation and damage location for large space truss structures: Secant method development and evaluation

NASA Technical Reports Server (NTRS)

Smith, Suzanne Weaver; Beattie, Christopher A.

1991-01-01

On-orbit testing of a large space structure will be required to complete the certification of any mathematical model for the structure dynamic response. The process of establishing a mathematical model that matches measured structure response is referred to as model correlation. Most model correlation approaches have an identification technique to determine structural characteristics from the measurements of the structure response. This problem is approached with one particular class of identification techniques - matrix adjustment methods - which use measured data to produce an optimal update of the structure property matrix, often the stiffness matrix. New methods were developed for identification to handle problems of the size and complexity expected for large space structures. Further development and refinement of these secant-method identification algorithms were undertaken. Also, evaluation of these techniques is an approach for model correlation and damage location was initiated.

Neurophysiological Identification of Cranial Nerves During Endoscopic Endonasal Surgery of Skull Base Tumors: Pilot Study Technical Report.

PubMed

Shkarubo, Alexey Nikolaevich; Chernov, Ilia Valerievich; Ogurtsova, Anna Anatolievna; Moshchev, Dmitry Aleksandrovich; Lubnin, Andrew Jurievich; Andreev, Dmitry Nicolaevich; Koval, Konstantin Vladimirovich

2017-02-01

Intraoperative identification of cranial nerves is crucial for safe surgery of skull base tumors. Currently, only a small number of published papers describe the technique of trigger electromyography (t-EMG) in endoscopic endonasal removal of such tumors. To assess the effectiveness of t-EMG in preventing intraoperative cranial nerve damage in endoscopic endonasal surgery of skull base tumors. Nine patients were operated on using the endoscopic endonasal approach within a 1-year period. The tumors included large skull base chordomas and trigeminal neurinomas localized in the cavernous sinus. During the surgical process, cranial nerve identification was carried out using monopolar and bipolar t-EMG methods. Assessment of cranial nerve functional activity was conducted both before and after tumor removal. We mapped 17 nerves in 9 patients. Third, fifth, and sixth cranial nerves were identified intraoperatively. There were no cases of postoperative functional impairment of the mapped cranial nerves. In one case we were unable to get an intraoperative response from the fourth cranial nerve and observed its postoperative transient plegia (the function was normal before surgery). t-EMG allows surgeons to control the safety of cranial nerves both during and after skull base tumor removal. Copyright © 2016 Elsevier Inc. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adhikary, Suraj; Eichman, Brandt F.

DNA glycosylases specialized for the repair of alkylation damage must identify, with fine specificity, a diverse array of subtle modifications within DNA. The current mechanism involves damage sensing through interrogation of the DNA duplex, followed by more specific recognition of the target base inside the active site pocket. To better understand the physical basis for alkylpurine detection, we determined the crystal structure of Schizosaccharomyces pombe Mag1 (spMag1) in complex with DNA and performed a mutational analysis of spMag1 and the close homologue from Saccharomyces cerevisiae (scMag). Despite strong homology, spMag1 and scMag differ in substrate specificity and cellular alkylation sensitivity,more » although the enzymological basis for their functional differences is unknown. We show that Mag preference for 1,N{sup 6}-ethenoadenine ({var_epsilon}A) is influenced by a minor groove-interrogating residue more than the composition of the nucleobase-binding pocket. Exchanging this residue between Mag proteins swapped their {var_epsilon}A activities, providing evidence that residues outside the extrahelical base-binding pocket have a role in identification of a particular modification in addition to sensing damage.« less

In vivo soft tissue differentiation by diffuse reflectance spectroscopy: preliminary results

NASA Astrophysics Data System (ADS)

Zam, Azhar; Stelzle, Florian; Tangermann-Gerk, Katja; Adler, Werner; Nkenke, Emeka; Neukam, Friedrich Wilhelm; Schmidt, Michael; Douplik, Alexandre

Remote laser surgery does not provide haptic feedback to operate layer by layer and preserve vulnerable anatomical structures like nerve tissue or blood vessels. The aim of this study is identification of soft tissue in vivo by diffuse reflectance spectroscopy to set the base for a feedback control system to enhance nerve preservation in oral and maxillofacial laser surgery. Various soft tissues can be identified by diffuse reflectance spectroscopy in vivo. The results may set the base for a feedback system to prevent nerve damage during oral and maxillofacial laser surgery.

Application of a Subspace-Based Fault Detection Method to Industrial Structures

NASA Astrophysics Data System (ADS)

Mevel, L.; Hermans, L.; van der Auweraer, H.

1999-11-01

Early detection and localization of damage allow increased expectations of reliability, safety and reduction of the maintenance cost. This paper deals with the industrial validation of a technique to monitor the health of a structure in operating conditions (e.g. rotating machinery, civil constructions subject to ambient excitations, etc.) and to detect slight deviations in a modal model derived from in-operation measured data. In this paper, a statistical local approach based on covariance-driven stochastic subspace identification is proposed. The capabilities and limitations of the method with respect to health monitoring and damage detection are discussed and it is explained how the method can be practically used in industrial environments. After the successful validation of the proposed method on a few laboratory structures, its application to a sports car is discussed. The example illustrates that the method allows the early detection of a vibration-induced fatigue problem of a sports car.

Breaking new ground for remote sensing in support of disaster relief efforts: Detecting and pinpointing earthquake damage in near real-time (El Salvador, January 2001)

NASA Astrophysics Data System (ADS)

Nezry, Edmond; Romeijn, Paul P.; Sarti, Francesco; Inglada, Jordi; Zagolski, Francis; Yakam-Simen, Francis

2002-01-01

On January 13th 2001, a very strong earthquake struck El-Salvador, causing almost 1000 deaths and huge destruction, leaving more than one million people homeless. As support to the rescue teams, a project was initiated to provide up-to date maps and to identify damages to housing and infrastructures, covering the whole country. Based on the analysis of SPOT Panchromatic satellite imagery, updated maps were delivered to the rescue teams within 72 hours after the earthquake. In addition, during the 10 days following the earthquake, high resolution mapping of the damages was carried out in cooperation and coordination with rescue teams and relief organizations. Some areas of particular interest were even processed and damage maps delivered through the Internet, three hours after the request. For the first time in the history of spaceborne Earth observation, identification and evaluation of the damages were delivered on-site, in real-time (during the interventions), to local authorities, rescue teams and humanitarian organizations. In this operation, operating 24 hours a day and technical ability were the keys for success and contributed to saving lives.

Near Real-Time Probabilistic Damage Diagnosis Using Surrogate Modeling and High Performance Computing

NASA Technical Reports Server (NTRS)

Warner, James E.; Zubair, Mohammad; Ranjan, Desh

2017-01-01

This work investigates novel approaches to probabilistic damage diagnosis that utilize surrogate modeling and high performance computing (HPC) to achieve substantial computational speedup. Motivated by Digital Twin, a structural health management (SHM) paradigm that integrates vehicle-specific characteristics with continual in-situ damage diagnosis and prognosis, the methods studied herein yield near real-time damage assessments that could enable monitoring of a vehicle's health while it is operating (i.e. online SHM). High-fidelity modeling and uncertainty quantification (UQ), both critical to Digital Twin, are incorporated using finite element method simulations and Bayesian inference, respectively. The crux of the proposed Bayesian diagnosis methods, however, is the reformulation of the numerical sampling algorithms (e.g. Markov chain Monte Carlo) used to generate the resulting probabilistic damage estimates. To this end, three distinct methods are demonstrated for rapid sampling that utilize surrogate modeling and exploit various degrees of parallelism for leveraging HPC. The accuracy and computational efficiency of the methods are compared on the problem of strain-based crack identification in thin plates. While each approach has inherent problem-specific strengths and weaknesses, all approaches are shown to provide accurate probabilistic damage diagnoses and several orders of magnitude computational speedup relative to a baseline Bayesian diagnosis implementation.

Geometric identification and damage detection of structural elements by terrestrial laser scanner

NASA Astrophysics Data System (ADS)

Hou, Tsung-Chin; Liu, Yu-Wei; Su, Yu-Min

2016-04-01

In recent years, three-dimensional (3D) terrestrial laser scanning technologies with higher precision and higher capability are developing rapidly. The growing maturity of laser scanning has gradually approached the required precision as those have been provided by traditional structural monitoring technologies. Together with widely available fast computation for massive point cloud data processing, 3D laser scanning can serve as an efficient structural monitoring alternative for civil engineering communities. Currently most research efforts have focused on integrating/calculating the measured multi-station point cloud data, as well as modeling/establishing the 3D meshes of the scanned objects. Very little attention has been spent on extracting the information related to health conditions and mechanical states of structures. In this study, an automated numerical approach that integrates various existing algorithms for geometric identification and damage detection of structural elements were established. Specifically, adaptive meshes were employed for classifying the point cloud data of the structural elements, and detecting the associated damages from the calculated eigenvalues in each area of the structural element. Furthermore, kd-tree was used to enhance the searching efficiency of plane fitting which were later used for identifying the boundaries of structural elements. The results of geometric identification were compared with M3C2 algorithm provided by CloudCompare, as well as validated by LVDT measurements of full-scale reinforced concrete beams tested in laboratory. It shows that 3D laser scanning, through the established processing approaches of the point cloud data, can offer a rapid, nondestructive, remote, and accurate solution for geometric identification and damage detection of structural elements.

Damage identification in cement paste amended with carbon nanotubes

NASA Astrophysics Data System (ADS)

Soltangharaei, Vafa; Anay, Rafal; Assi, Lateef; Ziehl, Paul; Matta, Fabio

2018-04-01

Cement-based composites have been used as reliable materials in building and civil engineering infrastructure for many decades. Although there are several advantages, some drawbacks such as premature cracking may be problematic for sensitive applications such as those found in nuclear power plants or associated waste storage facilities. In this study, acoustic emission monitoring was employed to detect stress waves associated with damage progression during uniaxial compressive loading. Acoustic emission data resulting from loading of plain cement paste prisms and cement paste prisms amended with carbon nanotubes are compared. Unsupervised pattern recognition is employed to categorize the data. Results indicate that increased acoustic emission activity was recorded for the plain cement paste prisms when compared to prisms amended with carbon nanotubes.

Current and Prospective Methods for Plant Disease Detection

PubMed Central

Fang, Yi; Ramasamy, Ramaraja P.

2015-01-01

Food losses due to crop infections from pathogens such as bacteria, viruses and fungi are persistent issues in agriculture for centuries across the globe. In order to minimize the disease induced damage in crops during growth, harvest and postharvest processing, as well as to maximize productivity and ensure agricultural sustainability, advanced disease detection and prevention in crops are imperative. This paper reviews the direct and indirect disease identification methods currently used in agriculture. Laboratory-based techniques such as polymerase chain reaction (PCR), immunofluorescence (IF), fluorescence in-situ hybridization (FISH), enzyme-linked immunosorbent assay (ELISA), flow cytometry (FCM) and gas chromatography-mass spectrometry (GC-MS) are some of the direct detection methods. Indirect methods include thermography, fluorescence imaging and hyperspectral techniques. Finally, the review also provides a comprehensive overview of biosensors based on highly selective bio-recognition elements such as enzyme, antibody, DNA/RNA and bacteriophage as a new tool for the early identification of crop diseases. PMID:26287253

Yields of damage to C4' deoxyribose and to pyrimidines in pUC18 by the direct effect of ionizing radiation.

PubMed

Peoples, Anita R; Lee, Jane; Weinfeld, Michael; Milligan, Jamie R; Bernhard, William A

2012-07-01

Our mechanistic understanding of damage formation in DNA by the direct effect relies heavily on what is known of free radical intermediates studied by EPR spectroscopy. Bridging this information to stable product formation requires methods with comparable sensitivities, a criterion met by the (32)P-post-labeling assay developed by Weinfeld and Soderlind, [Weinfeld,M. and Soderlind,K.-J.M. (1991) (32)P-Postlabeling detection of radiation-induced DNA damage: identification and estimation of thymine glycols and phosphoglycolate termini. Biochemistry, 30, 1091-1097] which when applied to the indirect effect, detected phosphoglycolate (pg) and thymine glycol (Tg). Here we applied this assay to the direct effect, measuring product yields in pUC18 films with hydration levels (Γ) of 2.5, 16 or 23 waters per nucleotide and X-irradiated at either 4 K or room temperature (RT). The yields of pg [G(pg)] for Γ ≈ 2.5 were 2.8 ± 0.2 nmol/J (RT) and 0.2 ± 0.3 nmol/J (4 K), which is evidence that the C4' radical contributes little to the total deoxyribose damage via the direct effect. The yield of detectable base damage [G(B*)] at Γ ≈ 2.5 was found to be 30.2 ± 1.0 nmol/J (RT) and 12.9 ± 0.7 nmol/J (4 K). While the base damage called B*, could be due to either oxidation or reduction, we argue that two reduction products, 5,6-dihydrouracil and 5,6-dihydrothymine, are the most likely candidates.

On the modal characteristics of damaging structures subjected to earthquakes

NASA Astrophysics Data System (ADS)

Carlo Ponzo, Felice; Ditommaso, Rocco; Auletta, Gianluca; Iacovino, Chiara; Mossucca, Antonello; Nigro, Antonella; Nigro, Domenico

2015-04-01

Structural Health Monitoring, especially for structures located in seismic prone areas, has assumed a meaning of great importance in last years, for the possibility to make a more objective and more rapid estimation of the damage occurred on buildings after a seismic event. In the last years many researchers are working to set-up new methodologies for Non-destructive Damage Evaluation based on the variation of the dynamic behaviour of structures under seismic loads. The NDE methods for damage detection and evaluation can be classified into four levels, according to the specific criteria provided by the Rytter. Each level of identification is correlated with specific information related to monitored structure. In fact, by increasing the level it is possible to obtain more information about the state of the health of the structures, to know if damage occurred on the structures, to quantify and localize the damage and to evaluate its impact on the monitored structure. Several authors discussed on the possibility to use the mode shape curvature to localize damage on structural elements, for example, by applying the curvature-based method to frequency response function instead of mode shape, and demonstrated the potential of this approach by considering real data. Damage detection approach based on dynamic monitoring of structural properties over time has received a considerable attention in recent scientific literature. In earthquake engineering field, the recourse to experimental research is necessary to understand the mechanical behaviour of the various structural and non-structural components. In this paper a new methodology to detect and localize a possible damage occurred on a framed structure after an earthquake is presented and discussed. The main outcomes retrieved from many numerical non linear dynamic models of reinforced concrete framed structures characterized by 3, 5 and 8 floors with different geometric configurations and designed for gravity loads only are here presented. In addition, the main results of experimental shaking table tests carried out on a steel framed model are also showed to confirm the effectiveness of the proposed procedure. Acknowledgements This study was partially funded by the Italian Civil Protection Department within the project DPC-RELUIS 2014 - RS4 ''Seismic observatory of structures and health monitoring''.

Automatic building identification under bomb damage conditions

NASA Astrophysics Data System (ADS)

Woodley, Robert; Noll, Warren; Barker, Joseph; Wunsch, Donald C., II

2009-05-01

Given the vast amount of image intelligence utilized in support of planning and executing military operations, a passive automated image processing capability for target identification is urgently required. Furthermore, transmitting large image streams from remote locations would quickly use available band width (BW) precipitating the need for processing to occur at the sensor location. This paper addresses the problem of automatic target recognition for battle damage assessment (BDA). We utilize an Adaptive Resonance Theory approach to cluster templates of target buildings. The results show that the network successfully classifies targets from non-targets in a virtual test bed environment.

Parameters Identification of Interface Friction Model for Ceramic Matrix Composites Based on Stress-Strain Response

NASA Astrophysics Data System (ADS)

Han, Xiao; Gao, Xiguang; Song, Yingdong

2017-10-01

An approach to identify parameters of interface friction model for Ceramic Matrix composites based on stress-strain response was developed. The stress distribution of fibers in the interface slip region and intact region of the damaged composite was determined by adopting the interface friction model. The relation between maximum strain, secant moduli of hysteresis loop and interface shear stress, interface de-bonding stress was established respectively with the method of symbolic-graphic combination. By comparing the experimental strain, secant moduli of hysteresis loop with computation values, the interface shear stress and interface de-bonding stress corresponding to first cycle were identified. Substituting the identification of parameters into interface friction model, the stress-strain curves were predicted and the predicted results fit experiments well. Besides, the influence of number of data points on identifying the value of interface parameters was discussed. And the approach was compared with the method based on the area of hysteresis loop.

Identification of a whitefly species by genomic and behavioral studies

USGS Publications Warehouse

Perring, T.M.; Cooper, A.D.; Rodriguez, R.J.; Farrar, C.A.; Bellows, T.S.

1993-01-01

An introduced whitefly species, responsible for over a half billion dollars in damage to U.S. agricultural production in 1991, is morphologically indistinguishable from Bemisia tabaci (Gennadius). However, with the use of polymerase chain reaction-based DNA differentiation tests, allozymic frequency analyses, crossing experiments, and mating behavior studies, the introduced whitefly is found to be a distinct species. Recognition of this new species, the silverleaf whitefly, is critical in the search for management options.

Identification and classification of failure modes in laminated composites by using a multivariate statistical analysis of wavelet coefficients

NASA Astrophysics Data System (ADS)

Baccar, D.; Söffker, D.

2017-11-01

Acoustic Emission (AE) is a suitable method to monitor the health of composite structures in real-time. However, AE-based failure mode identification and classification are still complex to apply due to the fact that AE waves are generally released simultaneously from all AE-emitting damage sources. Hence, the use of advanced signal processing techniques in combination with pattern recognition approaches is required. In this paper, AE signals generated from laminated carbon fiber reinforced polymer (CFRP) subjected to indentation test are examined and analyzed. A new pattern recognition approach involving a number of processing steps able to be implemented in real-time is developed. Unlike common classification approaches, here only CWT coefficients are extracted as relevant features. Firstly, Continuous Wavelet Transform (CWT) is applied to the AE signals. Furthermore, dimensionality reduction process using Principal Component Analysis (PCA) is carried out on the coefficient matrices. The PCA-based feature distribution is analyzed using Kernel Density Estimation (KDE) allowing the determination of a specific pattern for each fault-specific AE signal. Moreover, waveform and frequency content of AE signals are in depth examined and compared with fundamental assumptions reported in this field. A correlation between the identified patterns and failure modes is achieved. The introduced method improves the damage classification and can be used as a non-destructive evaluation tool.

Identification and Analysis of Partial Shading Breakdown Sites in CuIn xGa (1-x)Se 2 Modules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palmiotti, Elizabeth; Johnston, Steven; Gerber, Andreas

In this paper, CuIn xGa (1-x) (CIGS) mini-modules are stressed under reverse bias, resembling partial shading conditions, to predict and characterize where failures occur. Partial shading can cause permanent damage in the form of 'wormlike' defects on thin-film modules due to thermal runaway. This results in module-scale power losses. We have used dark lock-in thermography (DLIT) to spatially observe localized heating when reverse-bias breakdown occurs on various CIGS mini-modules. For better understanding of how and where these defects originated and propagated, we have developed techniques where the current is limited during reverse-bias stressing. This allows for DLIT-based detection and detailedmore » studying of the region where breakdown is initiated before thermal runaway leads to permanent damage. Statistics of breakdown sites using current-limited conditions has allowed for reasonable identification of the as-grown defects where permanent breakdown will likely originate. Scanning electron microscope results and wormlike defect analysis show that breakdown originates in defects such as small pits, craters, or cracks in the CIGS layer, and the wormlike defects propagate near the top CIGS interface.« less

Identification and Analysis of Partial Shading Breakdown Sites in CuIn xGa (1-x)Se 2 Modules

DOE PAGES

Palmiotti, Elizabeth; Johnston, Steven; Gerber, Andreas; ...

2017-12-20

In this paper, CuIn xGa (1-x) (CIGS) mini-modules are stressed under reverse bias, resembling partial shading conditions, to predict and characterize where failures occur. Partial shading can cause permanent damage in the form of 'wormlike' defects on thin-film modules due to thermal runaway. This results in module-scale power losses. We have used dark lock-in thermography (DLIT) to spatially observe localized heating when reverse-bias breakdown occurs on various CIGS mini-modules. For better understanding of how and where these defects originated and propagated, we have developed techniques where the current is limited during reverse-bias stressing. This allows for DLIT-based detection and detailedmore » studying of the region where breakdown is initiated before thermal runaway leads to permanent damage. Statistics of breakdown sites using current-limited conditions has allowed for reasonable identification of the as-grown defects where permanent breakdown will likely originate. Scanning electron microscope results and wormlike defect analysis show that breakdown originates in defects such as small pits, craters, or cracks in the CIGS layer, and the wormlike defects propagate near the top CIGS interface.« less

Coupling image processing and stress analysis for damage identification in a human premolar tooth.

PubMed

Andreaus, U; Colloca, M; Iacoviello, D

2011-08-01

Non-carious cervical lesions are characterized by the loss of dental hard tissue at the cement-enamel junction (CEJ). Exceeding stresses are therefore generated in the cervical region of the tooth that cause disruption of the bonds between the hydroxyapatite crystals, leading to crack formation and eventual loss of enamel and the underlying dentine. Damage identification was performed by image analysis techniques and allowed to quantitatively assess changes in teeth. A computerized two-step procedure was generated and applied to the first left maxillary human premolar. In the first step, dental images were digitally processed by a segmentation method in order to identify the damage. The considered morphological properties were the enamel thickness and total area, the number of fragments in which the enamel is chipped. The information retrieved by the data processing of the section images allowed to orient the stress investigation toward selected portions of the tooth. In the second step, a three-dimensional finite element model based on CT images of both the tooth and the periodontal ligament was employed to compare the changes occurring in the stress distributions in normal occlusion and malocclusion. The stress states were analyzed exclusively in the critical zones designated in the first step. The risk of failure at the CEJ and of crack initiation at the dentin-enamel junction through the quantification of first and third principal stresses, von Mises stress, and normal and tangential stresses, were also estimated. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

77 FR 49394 - Airworthiness Directives; Bombardier, Inc. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-16

... wiring within an ACCB and repair if necessary; and would require rework and re-identification of the... necessary] and rectification [rework] of the wiring installation within each ACCB. You may obtain further... first: Do a general visual inspection for chafing, damage, and insulation damage, and rework the wiring...

Modeling of Lamb Waves and Application to Crack Identification

DTIC Science & Technology

2009-09-01

and Structures, vol. 13, pp. 621–630, 2004. [13] Seth S Kessler , S. Mark Spearing, and Constantinos Soutis, “Damage detection in composite materials...growth in metallic structures. Kessler et al. [13] presented part of an experimental and analytical survey of candidate methods for in-situ damage

RESTORING HAZARDOUS SPILL-DAMAGED AREAS: TECHNIQUE IDENTIFICATION/ASSESSMENT

EPA Science Inventory

The goal of this study was to identify and assess methods that could be used to accelerate the restoration of lands damaged by spills of hazardous materials. The literature was reviewed to determine what response methods had been used in the past to clean up spills on land and id...

Dissemination of Earth Remote Sensing Data for Use in the NOAA/NWS Damage Assessment Toolkit

NASA Technical Reports Server (NTRS)

Molthan, Andrew; Burks, Jason; Camp, Parks; McGrath, Kevin; Bell, Jordan

2015-01-01

The National Weather Service has developed the Damage Assessment Toolkit (DAT), an application for smartphones and tablets that allows for the collection, geolocation, and aggregation of various damage indicators that are collected during storm surveys. The DAT supports the often labor-intensive process where meteorologists venture into the storm-affected area, allowing them to acquire geotagged photos of the observed damage while also assigning estimated EF-scale categories based upon their observations. Once the data are collected, the DAT infrastructure aggregates the observations into a server that allows other meteorologists to perform quality control and other analysis steps before completing their survey and making the resulting data available to the public. In addition to in-person observations, Earth remote sensing from operational, polar-orbiting satellites can support the damage assessment process by identifying portions of damage tracks that may be missed due to road limitations, access to private property, or time constraints. Products resulting from change detection techniques can identify damage to vegetation and the land surface, aiding in the survey process. In addition, higher resolution commercial imagery can corroborate ground-based surveys by examining higher-resolution commercial imagery. As part of an ongoing collaboration, NASA and NOAA are working to integrate near real-time Earth remote sensing observations into the NOAA/NWS Damage Assessment Toolkit. This presentation will highlight recent developments in a streamlined approach for disseminating Earth remote sensing data via web mapping services and a new menu interface that has been integrated within the DAT. A review of current and future products will be provided, including products derived from MODIS and VIIRS for preliminary track identification, along with conduits for higher-resolution Landsat, ASTER, and commercial imagery as they become available. In addition to tornado damage assessments, the team is also investigating the use of near real-time imagery for identifying hail damage to vegetation, which also results in large swaths of damage, particularly in the central United States during the peak growing season months of June, July, and August. This presentation will present an overview of recent activities, challenges and successes, best practices, and opportunities for future work and collaboration

A Sensor Data Fusion System Based on k-Nearest Neighbor Pattern Classification for Structural Health Monitoring Applications

PubMed Central

Vitola, Jaime; Pozo, Francesc; Tibaduiza, Diego A.; Anaya, Maribel

2017-01-01

Civil and military structures are susceptible and vulnerable to damage due to the environmental and operational conditions. Therefore, the implementation of technology to provide robust solutions in damage identification (by using signals acquired directly from the structure) is a requirement to reduce operational and maintenance costs. In this sense, the use of sensors permanently attached to the structures has demonstrated a great versatility and benefit since the inspection system can be automated. This automation is carried out with signal processing tasks with the aim of a pattern recognition analysis. This work presents the detailed description of a structural health monitoring (SHM) system based on the use of a piezoelectric (PZT) active system. The SHM system includes: (i) the use of a piezoelectric sensor network to excite the structure and collect the measured dynamic response, in several actuation phases; (ii) data organization; (iii) advanced signal processing techniques to define the feature vectors; and finally; (iv) the nearest neighbor algorithm as a machine learning approach to classify different kinds of damage. A description of the experimental setup, the experimental validation and a discussion of the results from two different structures are included and analyzed. PMID:28230796

A Sensor Data Fusion System Based on k-Nearest Neighbor Pattern Classification for Structural Health Monitoring Applications.

PubMed

Vitola, Jaime; Pozo, Francesc; Tibaduiza, Diego A; Anaya, Maribel

2017-02-21

Civil and military structures are susceptible and vulnerable to damage due to the environmental and operational conditions. Therefore, the implementation of technology to provide robust solutions in damage identification (by using signals acquired directly from the structure) is a requirement to reduce operational and maintenance costs. In this sense, the use of sensors permanently attached to the structures has demonstrated a great versatility and benefit since the inspection system can be automated. This automation is carried out with signal processing tasks with the aim of a pattern recognition analysis. This work presents the detailed description of a structural health monitoring (SHM) system based on the use of a piezoelectric (PZT) active system. The SHM system includes: (i) the use of a piezoelectric sensor network to excite the structure and collect the measured dynamic response, in several actuation phases; (ii) data organization; (iii) advanced signal processing techniques to define the feature vectors; and finally; (iv) the nearest neighbor algorithm as a machine learning approach to classify different kinds of damage. A description of the experimental setup, the experimental validation and a discussion of the results from two different structures are included and analyzed.

Identification of Primary Transcriptional Regulation of Cell Cycle-Regulated Genes upon DNA Damage

PubMed Central

Zhou, Tong; Chou, Jeff; Mullen, Thomas E.; Elkon, Rani; Zhou, Yingchun; Simpson, Dennis A.; Bushel, Pierre R.; Paules, Richard S.; Lobenhofer, Edward K.; Hurban, Patrick; Kaufmann, William K.

2007-01-01

The changes in global gene expression in response to DNA damage may derive from either direct induction or repression by transcriptional regulation or indirectly by synchronization of cells to specific cell cycle phases, such as G1 or G2. We developed a model that successfully estimated the expression levels of >400 cell cycle-regulated genes in normal human fibroblasts based on the proportions of cells in each phase of the cell cycle. By isolating effects on the gene expression associated with the cell cycle phase redistribution after genotoxin treatment, the direct transcriptional target genes were distinguished from genes for which expression changed secondary to cell synchronization. Application of this model to ionizing radiation (IR)-treated normal human fibroblasts identified 150 of 406 cycle-regulated genes as putative direct transcriptional targets of IR-induced DNA damage. Changes in expression of these genes after IR treatment derived from both direct transcriptional regulation and cell cycle synchronization. PMID:17404513

Fatigue crack detection and identification by the elastic wave propagation method

NASA Astrophysics Data System (ADS)

Stawiarski, Adam; Barski, Marek; Pająk, Piotr

2017-05-01

In this paper the elastic wave propagation phenomenon was used to detect the initiation of the fatigue damage in isotropic plate with a circular hole. The safety and reliability of structures mostly depend on the effectiveness of the monitoring methods. The Structural Health Monitoring (SHM) system based on the active pitch-catch measurement technique was proposed. The piezoelectric (PZT) elements was used as an actuators and sensors in the multipoint measuring system. The comparison of the intact and defected structures has been used by damage detection algorithm. One part of the SHM system has been responsible for detection of the fatigue crack initiation. The second part observed the evolution of the damage growth and assess the size of the defect. The numerical results of the wave propagation phenomenon has been used to present the effectiveness and accuracy of the proposed method. The preliminary experimental analysis has been carried out during the tension test of the aluminum plate with a circular hole to determine the efficiency of the measurement technique.

Towards Prognostics of Power MOSFETs: Accelerated Aging and Precursors of Failure

NASA Technical Reports Server (NTRS)

Celaya, Jose R.; Saxena, Abhinav; Wysocki, Philip; Saha, Sankalita; Goebel, Kai

2010-01-01

This paper presents research results dealing with power MOSFETs (metal oxide semiconductor field effect transistor) within the prognostics and health management of electronics. Experimental results are presented for the identification of the on-resistance as a precursor to failure of devices with die-attach degradation as a failure mechanism. Devices are aged under power cycling in order to trigger die-attach damage. In situ measurements of key electrical and thermal parameters are collected throughout the aging process and further used for analysis and computation of the on-resistance parameter. Experimental results show that the devices experience die-attach damage and that the on-resistance captures the degradation process in such a way that it could be used for the development of prognostics algorithms (data-driven or physics-based).

Case report highlighting how wound path identification on CT can help identify organ damage in abdominal blast injuries.

PubMed

Fischer, Tatjana V; Folio, Les R; Backus, Christopher E; Bunger, Rolf

2012-01-01

Penetrating trauma is frequently encountered in forward deployed military combat hospitals. Abdominal blast injuries represent nearly 11% of combat injuries, and multiplanar computed tomography imaging is optimal for injury assessment and surgical planning. We describe a multiplanar approach to assessment of blast and ballistic injuries, which allows for more expeditious detection of missile tracts and damage caused along the path. Precise delineation of the trajectory path and localization of retained fragments enables time-saving and detailed evaluation of associated tissue and vascular injury. For consistent and reproducible documentation of fragment locations in the body, we propose a localization scheme based on Cartesian coordinates to report 3-dimensional locations of fragments and demonstrating the application in three cases of abdominal blast injury.

3D Mapping of plasma effective areas via detection of cancer cell damage induced by atmospheric pressure plasma jets

NASA Astrophysics Data System (ADS)

Han, Xu; Liu, Yueing; Stack, M. Sharon; Ptasinska, Sylwia

2014-12-01

In the present study, a nitrogen atmospheric pressure plasma jet (APPJ) was used for irradiation of oral cancer cells. Since cancer cells are very susceptible to plasma treatment, they can be used as a tool for detection of APPJ-effective areas, which extended much further than the visible part of the APPJ. An immunofluorescence assay was used for DNA damage identification, visualization and quantification. Thus, the effective damage area and damage level were determined and plotted as 3D images.

Structural damage identification using an enhanced thermal exchange optimization algorithm

NASA Astrophysics Data System (ADS)

Kaveh, A.; Dadras, A.

2018-03-01

The recently developed optimization algorithm-the so-called thermal exchange optimization (TEO) algorithm-is enhanced and applied to a damage detection problem. An offline parameter tuning approach is utilized to set the internal parameters of the TEO, resulting in the enhanced heat transfer optimization (ETEO) algorithm. The damage detection problem is defined as an inverse problem, and ETEO is applied to a wide range of structures. Several scenarios with noise and noise-free modal data are tested and the locations and extents of damages are identified with good accuracy.

76 FR 54737 - Proposed Information Collection; Comment Request; Southeast Region Gear Identification Requirements

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-02

... Collection; Comment Request; Southeast Region Gear Identification Requirements AGENCY: National Oceanic and... gear be marked are essential to facilitate enforcement. The ability to link fishing gear to the vessel... fishing gear is also valuable in actions concerning damage, loss, and civil proceedings. The requirements...

Objective instrumental memory and performance tests for evaluation of patients with brain damage: a search for a behavioral diagnostic tool.

PubMed

Harness, B Z; Bental, E; Carmon, A

1976-03-01

Cognition and performance of patients with localized and diffuse brain damage was evaluated through the application of objective perceptual testing. A series of visual perceptual and verbal tests, memory tests, as well as reaction time tasks were administered to the patients by logic programming equipment. In order to avoid a bias due to communicative disorders, all responses were motor, and achievement was scored in terms of correct identification and latencies of response. Previously established norms based on a large sample of non-brain-damaged hospitalized patients served to standardize the performance of the brain-damaged patient since preliminary results showed that age and educational level constitute an important variable affecting performance of the control group. The achievement of brain-damaged patients, corrected for these factors, was impaired significantly in all tests with respect to both recognition and speed of performance. Lateralized effects of brain damage were not significantly demonstrated. However, when the performance was analyzed with respect to the locus of visual input, it was found that patients with right hemispheric lesions showed impairment mainly on perception of figurative material, and that this deficit was more apparent in the left visual field. Conversely, patients with left hemispheric lesions tended to show impairment on perception of visually presented verbal material when the input was delivered to the right visual field.

Application of crowdsourced hail data and damage information for hail risk assessment in the province of Styria, Austria

NASA Astrophysics Data System (ADS)

Tani, Satyanarayana; Rechberger, Andreas; Süsser Rechberger, Barbara; Teschl, Reinhard; Paulitsch, Helmut

2017-04-01

Hail storm damage is a major concern to the farmers in the province of Styria, Austria. Each year severe hail storms are causing damages to crops, resulting in losses of millions of euros. High spatial and timely ground truth information of the hail event and crop damage measurements are essential for better hail risk assessment. Usually, hail pad networks and visual damage surveys are used to collect the hail data and corresponding damage information. However, these hail pad networks are expensive and need laborious maintenance. The traditional crop damage assessment approaches are very labour-intensive and time-consuming. The advancements in information and communication technology (ICT) and the power of citizen based crowdsourcing data, will help to overcome these problems and ultimately provide a platform for data collection. A user-friendly and bilingual web interface was developed to collect hail data and crop damage information in the province of Styria, Austria. The dynamic web interface was developed using HTML5, JavaScript, and PHP7 combined with a MySQL database back-end. OpenStreetMap was integrated into the web interface and tile server optimised for an easy identification of geolocation information. The user needs an internet connection to transfer the data through smartphone or computer. Crowdsourced data will be quality tested and evaluated with 3D single polarisation C-band weather radar data to remove potential false reports. Further, the relationship between the reported hail events and radar-based hail detection algorithms (Waldvogel and Auer) and derived hail signature information intended for crop hail risk assessment will be investigated. The details about the web interface tool, application and verification methods to collect, analyse, and integrate different data sets are given. Further, the high spatial risk assessment information is communicated to support risk management policy.

Genomic Physics. Multiple Laser Beam Treatment of Alzheimer's Disease

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2014-03-01

The synapses affected by Alzheimer's disease can be rejuvenated by the multiple ultrashort wavelength laser beams.[2] The guiding lasers scan the whole area to detect the amyloid plaques based on the laser scattering technique. The scanning lasers pinpoint the areas with plaques and eliminate them. Laser interaction is highly efficient, because of the focusing capabilities and possibility for the identification of the damaging proteins by matching the protein oscillation eigen-frequency with laser frequency.[3] Supported by Nikola Tesla Labs, La Jolla, California, USA.

Damage identification in highway bridges using distribution factors

NASA Astrophysics Data System (ADS)

Gangone, Michael V.; Whelan, Matthew J.

2017-04-01

The U.S. infrastructure system is well behind the needs of the 21st century and in dire need of improvements. The American Society of Civil Engineers (ASCE) graded America's Infrastructure as a "D+" in its recent 2013 Report Card. Bridges are a major component of the infrastructure system and were awarded a "C+". Nearly 25 percent of the nation's bridges are categorized as deficient by the Federal Highway Administration (FWHA). Most bridges were designed with an expected service life of roughly 50 years and today the average age of a bridge is 42 years. Finding alternative methods of condition assessment which captures the true performance of the bridge is of high importance. This paper discusses the monitoring of two multi-girder/stringer bridges at different ages of service life. Normal strain measurements were used to calculate the load distribution factor at the midspan of the bridge under controlled loading conditions. Controlled progressive damage was implemented to one of the superstructures to determine if the damage could be detected using the distribution factor. An uncertainty analysis, based on the accuracy and precision of the normal strain measurement, was undertaken to determine how effective it is to use the distribution factor measurement as a damage indicator. The analysis indicates that this load testing parameter may be an effective measure for detecting damage.

Ionizing Radiation-Induced DNA Damage and Its Repair in Human Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dizdaroglu, Miral

DNA damage in mammalian chromatin in vitro and in cultured mammalian cells including human cells was studied. In the first phase of these studies, a cell culture laboratory was established. Necessary equipment including an incubator, a sterile laminar flow hood and several centrifuges was purchased. We have successfully grown several cell lines such as murine hybridoma cells, V79 cells and human K562 leukemia cells. This was followed by the establishment of a methodology for the isolation of chromatin from cells. This was a very important step, because a routine and successful isolation of chromatin was a prerequisite for the successmore » of the further studies in this project, the aim of which was the measurement of DNA darnage in mammalian chromatin in vitro and in cultured cells. Chromatin isolation was accomplished using a slightly modified procedure of the one described by Mee & Adelstein (1981). For identification and quantitation of DNA damage in cells, analysis of chromatin was preferred over the analysis of "naked DNA" for the following reasons: i. DNA may not be extracted efficiently from nucleoprotein in exposed cells, due to formation of DNA-protein cross-links, ii. the extractability of DNA is well known to decrease with increasing doses of radiation, iii. portions of DNA may not be extracted due to fragmentation, iv. unextracted DNA may contain a significant portion of damaged DNA bases and DNA-protein cross-links. The technique of gas chromatography/mass spectrometry (GC/MS), which was used in the present project, permits the identification and quantitation of modified DNA bases in chromatin in the presence of proteins without the necessity of first isolating DNA from chromatin. This has been demonstrated previously by the results from our laboratory and by the results obtained during the course of the present project. The quality of isolated chromatin was tested by measurement of its content of DNA, proteins, and RNA, by analysis of its protein components using gel electrophoresis, and by absorption spectral analysis. GeneraUy, the RNA content was <5% of the amount of DNA, and the ratio of the amount of protein to that of DNA was =1. 8-2 (w/w). Having developed a suitable methodology for routine isolation of chromatin from mammalian cells, studies of DNA damage in chromatin in vitro and in cultured human cells were pursued.« less

Primary Retinal Cultures as a Tool for Modeling Diabetic Retinopathy: An Overview

PubMed Central

Varano, Monica; Mallozzi, Cinzia; Gaddini, Lucia; Formisano, Giuseppe; Pricci, Flavia

2015-01-01

Experimental models of diabetic retinopathy (DR) have had a crucial role in the comprehension of the pathophysiology of the disease and the identification of new therapeutic strategies. Most of these studies have been conducted in vivo, in animal models. However, a significant contribution has also been provided by studies on retinal cultures, especially regarding the effects of the potentially toxic components of the diabetic milieu on retinal cell homeostasis, the characterization of the mechanisms on the basis of retinal damage, and the identification of potentially protective molecules. In this review, we highlight the contribution given by primary retinal cultures to the study of DR, focusing on early neuroglial impairment. We also speculate on possible themes into which studies based on retinal cell cultures could provide deeper insight. PMID:25688355

Hypertensive retinopathy identification through retinal fundus image using backpropagation neural network

NASA Astrophysics Data System (ADS)

Syahputra, M. F.; Amalia, C.; Rahmat, R. F.; Abdullah, D.; Napitupulu, D.; Setiawan, M. I.; Albra, W.; Nurdin; Andayani, U.

2018-03-01

Hypertension or high blood pressure can cause damage of blood vessels in the retina of eye called hypertensive retinopathy (HR). In the event Hypertension, it will cause swelling blood vessels and a decrese in retina performance. To detect HR in patients body, it is usually performed through physical examination of opthalmoscope which is still conducted manually by an ophthalmologist. Certainly, in such a manual manner, takes a ong time for a doctor to detetct HR on aa patient based on retina fundus iamge. To overcome ths problem, a method is needed to identify the image of retinal fundus automatically. In this research, backpropagation neural network was used as a method for retinal fundus identification. The steps performed prior to identification were pre-processing (green channel, contrast limited adapative histogram qualization (CLAHE), morphological close, background exclusion, thresholding and connected component analysis), feature extraction using zoning. The results show that the proposed method is able to identify retinal fundus with an accuracy of 95% with maximum epoch of 1500.

Application of remote sensing in agriculture and forestry and ground truth documentation in resource planning

NASA Technical Reports Server (NTRS)

1974-01-01

Varied small scale imagery was used for detecting and assessing damage by the southern pine beetle. The usefulness of ERTS scanner imagery for vegetation classification and pine beetle damage detection and assessment is evaluated. Ground truth acquisition for forest identification using multispectral aerial photographs is reviewed.

Identification of Damaged Wheat Kernels and Cracked-Shell Hazelnuts with Impact Acoustics Time-Frequency Patterns

USDA-ARS?s Scientific Manuscript database

A new adaptive time-frequency (t-f) analysis and classification procedure is applied to impact acoustic signals for detecting hazelnuts with cracked shells and three types of damaged wheat kernels. Kernels were dropped onto a steel plate, and the resulting impact acoustic signals were recorded with ...

Fluorescence-based recombination assay for sensitive and specific detection of genotoxic carcinogens in human cells.

PubMed

Ireno, Ivanildce C; Baumann, Cindy; Stöber, Regina; Hengstler, Jan G; Wiesmüller, Lisa

2014-05-01

In vitro genotoxicity tests are known to suffer from several shortcomings, mammalian cell-based assays, in particular, from low specificities. Following a novel concept of genotoxicity detection, we developed a fluorescence-based method in living human cells. The assay quantifies DNA recombination events triggered by DNA double-strand breaks and damage-induced replication fork stalling predicted to detect a broad spectrum of genotoxic modes of action. To maximize sensitivities, we engineered a DNA substrate encompassing a chemoresponsive element from the human genome. Using this substrate, we screened various human tumor and non-transformed cell types differing in the DNA damage response, which revealed that detection of genotoxic carcinogens was independent of the p53 status but abrogated by apoptosis. Cell types enabling robust and sensitive genotoxicity detection were selected for the generation of reporter clones with chromosomally integrated DNA recombination substrate. Reporter cell lines were scrutinized with 21 compounds, stratified into five sets according to the established categories for identification of carcinogenic compounds: genotoxic carcinogens ("true positives"), non-genotoxic carcinogens, compounds without genotoxic or carcinogenic effect ("true negatives") and non-carcinogenic compounds, which have been reported to induce chromosomal aberrations or mutations in mammalian cell-based assays ("false positives"). Our results document detection of genotoxic carcinogens in independent cell clones and at levels of cellular toxicities <60 % with a sensitivity of >85 %, specificity of ≥90 % and detection of false-positive compounds <17 %. Importantly, through testing cyclophosphamide in combination with primary hepatocyte cultures, we additionally provide proof-of-concept for the identification of carcinogens requiring metabolic activation using this novel assay system.

A feasibility study of damage detection in beams using high-speed camera (Conference Presentation)

NASA Astrophysics Data System (ADS)

Wan, Chao; Yuan, Fuh-Gwo

2017-04-01

In this paper a method for damage detection in beam structures using high-speed camera is presented. Traditional methods of damage detection in structures typically involve contact (i.e., piezoelectric sensor or accelerometer) or non-contact sensors (i.e., laser vibrometer) which can be costly and time consuming to inspect an entire structure. With the popularity of the digital camera and the development of computer vision technology, video cameras offer a viable capability of measurement including higher spatial resolution, remote sensing and low-cost. In the study, a damage detection method based on the high-speed camera was proposed. The system setup comprises a high-speed camera and a line-laser which can capture the out-of-plane displacement of a cantilever beam. The cantilever beam with an artificial crack was excited and the vibration process was recorded by the camera. A methodology called motion magnification, which can amplify subtle motions in a video is used for modal identification of the beam. A finite element model was used for validation of the proposed method. Suggestions for applications of this methodology and challenges in future work will be discussed.

Recognition of Damaged Arrow-Road Markings by Visible Light Camera Sensor Based on Convolutional Neural Network.

PubMed

Vokhidov, Husan; Hong, Hyung Gil; Kang, Jin Kyu; Hoang, Toan Minh; Park, Kang Ryoung

2016-12-16

Automobile driver information as displayed on marked road signs indicates the state of the road, traffic conditions, proximity to schools, etc. These signs are important to insure the safety of the driver and pedestrians. They are also important input to the automated advanced driver assistance system (ADAS), installed in many automobiles. Over time, the arrow-road markings may be eroded or otherwise damaged by automobile contact, making it difficult for the driver to correctly identify the marking. Failure to properly identify an arrow-road marker creates a dangerous situation that may result in traffic accidents or pedestrian injury. Very little research exists that studies the problem of automated identification of damaged arrow-road marking painted on the road. In this study, we propose a method that uses a convolutional neural network (CNN) to recognize six types of arrow-road markings, possibly damaged, by visible light camera sensor. Experimental results with six databases of Road marking dataset, KITTI dataset, Málaga dataset 2009, Málaga urban dataset, Naver street view dataset, and Road/Lane detection evaluation 2013 dataset, show that our method outperforms conventional methods.

Recognition of Damaged Arrow-Road Markings by Visible Light Camera Sensor Based on Convolutional Neural Network

PubMed Central

Vokhidov, Husan; Hong, Hyung Gil; Kang, Jin Kyu; Hoang, Toan Minh; Park, Kang Ryoung

2016-01-01

Automobile driver information as displayed on marked road signs indicates the state of the road, traffic conditions, proximity to schools, etc. These signs are important to insure the safety of the driver and pedestrians. They are also important input to the automated advanced driver assistance system (ADAS), installed in many automobiles. Over time, the arrow-road markings may be eroded or otherwise damaged by automobile contact, making it difficult for the driver to correctly identify the marking. Failure to properly identify an arrow-road marker creates a dangerous situation that may result in traffic accidents or pedestrian injury. Very little research exists that studies the problem of automated identification of damaged arrow-road marking painted on the road. In this study, we propose a method that uses a convolutional neural network (CNN) to recognize six types of arrow-road markings, possibly damaged, by visible light camera sensor. Experimental results with six databases of Road marking dataset, KITTI dataset, Málaga dataset 2009, Málaga urban dataset, Naver street view dataset, and Road/Lane detection evaluation 2013 dataset, show that our method outperforms conventional methods. PMID:27999301

DNA capture and next-generation sequencing can recover whole mitochondrial genomes from highly degraded samples for human identification

PubMed Central

2013-01-01

Background Mitochondrial DNA (mtDNA) typing can be a useful aid for identifying people from compromised samples when nuclear DNA is too damaged, degraded or below detection thresholds for routine short tandem repeat (STR)-based analysis. Standard mtDNA typing, focused on PCR amplicon sequencing of the control region (HVS I and HVS II), is limited by the resolving power of this short sequence, which misses up to 70% of the variation present in the mtDNA genome. Methods We used in-solution hybridisation-based DNA capture (using DNA capture probes prepared from modern human mtDNA) to recover mtDNA from post-mortem human remains in which the majority of DNA is both highly fragmented (<100 base pairs in length) and chemically damaged. The method ‘immortalises’ the finite quantities of DNA in valuable extracts as DNA libraries, which is followed by the targeted enrichment of endogenous mtDNA sequences and characterisation by next-generation sequencing (NGS). Results We sequenced whole mitochondrial genomes for human identification from samples where standard nuclear STR typing produced only partial profiles or demonstrably failed and/or where standard mtDNA hypervariable region sequences lacked resolving power. Multiple rounds of enrichment can substantially improve coverage and sequencing depth of mtDNA genomes from highly degraded samples. The application of this method has led to the reliable mitochondrial sequencing of human skeletal remains from unidentified World War Two (WWII) casualties approximately 70 years old and from archaeological remains (up to 2,500 years old). Conclusions This approach has potential applications in forensic science, historical human identification cases, archived medical samples, kinship analysis and population studies. In particular the methodology can be applied to any case, involving human or non-human species, where whole mitochondrial genome sequences are required to provide the highest level of maternal lineage discrimination. Multiple rounds of in-solution hybridisation-based DNA capture can retrieve whole mitochondrial genome sequences from even the most challenging samples. PMID:24289217

Discovering Mercury Protein Modifications in Whole Proteomes Using Natural Isotope Distributions Observed in Liquid Chromatography-Tandem Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Polacco, Benjamin J.; Purvine, Samuel O.; Zink, Erika M.

2011-08-01

The identification of peptides that result from post-translational modifications is critical for understanding normal pathways of cellular regulation as well as identifying damage from, or exposures to xenobiotics, i.e. the exposome. However, because of their low abundance in proteomes, effective detection of modified peptides by mass spectrometry (MS) typically requires enrichment to eliminate false identifications. We present a new method for confidently identifying peptides with mercury (Hg)-containing adducts that is based on the influence of mercury’s seven stable isotopes on peptide isotope distributions detected by high-resolution MS. Using a pure protein and E. coli cultures exposed to phenyl mercuric acetate,more » we show the pattern of peak heights in isotope distributions from primary MS single scans efficiently identified Hg adducts in data from chromatographic separation coupled with tandem mass spectrometry with sensitivity and specificity greater than 90%. Isotope distributions are independent of peptide identifications based on peptide fragmentation (e.g. by SEQUEST), so both methods can be combined to eliminate false positives. Summing peptide isotope distributions across multiple scans improved specificity to 99.4% and sensitivity above 95%, affording identification of an unexpected Hg modification. We also illustrate the theoretical applicability of the method for detection of several less common elements including the essential element, selenium, as selenocysteine in peptides.« less

Identification and Control of Common Insect Pests of Ornamental Shrubs and Trees.

ERIC Educational Resources Information Center

Gesell, Stanley G.

This agriculture extension service publication from Pennsylvania State University introduces the identification and control of common ornamental insect pests. For each of the insects or insect groups (i.e. aphids) identified in this publication, information on host plants, pest description, and damage caused by the pest is given. Also a calendar…

High resolution melting (HRM) analysis in sugar beet: identification of SNP markers associated to Fusarium resistance

USDA-ARS?s Scientific Manuscript database

Fusarium spp. cause severe damage in many agricultural crops including sugar beet. Sugar beet needs to be protected from these soil borne pathogens to guarantee an optimal sugar yield in the field. The genetic control is the key to overcoming this disease. Identification of single nucleotide polymor...

Thermodynamic Signature of DNA Damage: Characterization of DNA with a 5-Hydroxy-2'-deoxycytidine•2'-Deoxyguanosine Base Pair

PubMed Central

Ganguly, Manjori; Szulik, Marta W.; Donahue, Patrick S.; Clancy, Kate; Stone, Michael P.; Gold, Barry

2012-01-01

Oxidation of DNA due to exposure to reactive oxygen species is a major source of DNA damage. One of the oxidation lesions formed, 5-hydroxy-2'-deoxycytidine, has been shown to miscode by some replicative DNA polymerases but not by error prone polymerases capable of translesion synthesis. The 5-hydroxy-2'-deoxycytidine lesion is repaired by DNA glycosylases that require the 5-hydroxycytidine base to be extrahelical so it can enter into the enzyme's active site where it is excised off the DNA backbone to afford an abasic site. The thermodynamic and NMR results presented herein, describe the effect of a 5-hydroxy-2'-deoxycytidine•2'-deoxyguanosine base pair on the stability of two different DNA duplexes. The results demonstrate that the lesion is highly destabilizing and that the energy barrier for the unstacking of 5-hydroxy-2'-deoxycytidine from the DNA duplex may be low. This could provide a thermodynamic mode of adduct identification by DNA glycosylases that require the lesion to be extrahelical. PMID:22332945

[Effect of climatic mean value change on the evaluation result of rice delayed cold damage in Liaoning Province, Northeast China].

PubMed

Ji, Rui-peng; Yu, Wen-ying; Wu, Jin-wen; Feng, Rui; Zhang, Yu-shu

2015-06-01

The anomaly of mean temperature summation from May to September (ΔT5-9) was commonly used to assess delayed cold damage of rice in Northeast China, but whether the change of statistics years for climatic mean value (ΣT5-9) would affect the, evaluation results of Liaoning rice under cold damage needed to be further studied. By using the meteorological industry standard of the People's Republic of China "technical standard on rice cold damage evaluation" (QX/T 182- 2013) and the supplemental indices (ΔT5-9), the index (ΣT5-9) was calculated in four periods 1961-1990 (S1), 1971-2000 (S2), 1981-2010 (S3) and 1961-2010 (S4), and the spatial and temporal changes of cold damage in Liaoning Province were analyzed based on the ratio between cold damage stations and total stations (IOC) and the occurrence frequency. The results showed that the heat condition (Σ T5-9) in rice growing season increased obviously and the spatial and temporal changes were significant from 1961 to 2010. The original meteorological index of rice cold damage was improved by using quadratic polynomial model. The identification results were similar between S2 and S4. The variation coefficient of IOC in S3 was lower than that of the other three. Compared with the typical rice yield reduction years, the evaluation results accorded better with the actual situation in evaluating the rice delayed cold damage in Liaoning during study period by using the S3 climate mean value. The results could provide evidence for accurately evaluating the variation of rice cold damage in spatial and temporal distribution in Liaoning Province under the background of global climate change.

Damage source identification of reinforced concrete structure using acoustic emission technique.

PubMed

Panjsetooni, Alireza; Bunnori, Norazura Muhamad; Vakili, Amir Hossein

2013-01-01

Acoustic emission (AE) technique is one of the nondestructive evaluation (NDE) techniques that have been considered as the prime candidate for structural health and damage monitoring in loaded structures. This technique was employed for investigation process of damage in reinforced concrete (RC) frame specimens. A number of reinforced concrete RC frames were tested under loading cycle and were simultaneously monitored using AE. The AE test data were analyzed using the AE source location analysis method. The results showed that AE technique is suitable to identify the sources location of damage in RC structures.

Damage Source Identification of Reinforced Concrete Structure Using Acoustic Emission Technique

PubMed Central

Panjsetooni, Alireza; Bunnori, Norazura Muhamad; Vakili, Amir Hossein

2013-01-01

Acoustic emission (AE) technique is one of the nondestructive evaluation (NDE) techniques that have been considered as the prime candidate for structural health and damage monitoring in loaded structures. This technique was employed for investigation process of damage in reinforced concrete (RC) frame specimens. A number of reinforced concrete RC frames were tested under loading cycle and were simultaneously monitored using AE. The AE test data were analyzed using the AE source location analysis method. The results showed that AE technique is suitable to identify the sources location of damage in RC structures. PMID:23997681

IDENTIFICATION OF DIFFERENTIALLY EXPRESSED GENES IN THE KIDNEYS OF GROWTH HORMONE TRANSGENIC MICE

PubMed Central

Coschigano, K.T.; Wetzel, A.N.; Obichere, N.; Sharma, A.; Lee, S.; Rasch, R.; Guigneaux, M.M.; Flyvbjerg, A.; Wood, T.G.; Kopchick, J.J.

2010-01-01

Objective Bovine growth hormone (bGH) transgenic mice develop severe kidney damage. This damage may be due, at least in part, to changes in gene expression. Identification of genes with altered expression in the bGH kidney may identify mechanisms leading to damage in this system that may also be relevant to other models of kidney damage. Design cDNA subtraction libraries, northern blot analyses, microarray analyses and real-time reverse transcription polymerase chain reaction (RT/PCR) assays were used to identify and verify specific genes exhibiting differential RNA expression between kidneys of bGH mice and their non-transgenic (NT) littermates. Results Immunoglobulins were the vast majority of genes identified by the cDNA subtractions and the microarray analyses as being up-regulated in bGH. Several glycoprotein genes and inflammation-related genes also showed increased RNA expression in the bGH kidney. In contrast, only a few genes were identified as being significantly down-regulated in the bGH kidney. The most notable decrease in RNA expression was for the gene encoding kidney androgen-regulated protein. Conclusions A number of genes were identified as being differentially expressed in the bGH kidney. Inclusion of two groups, immunoglobulins and inflammation-related genes, suggests a role of the immune system in bGH kidney damage. PMID:20655258

A Convex Hull-Based New Metric for Quantification of Bladder Wall Irregularity in Pediatric Patients With Congenital Anomalies of the Kidney and Urinary Tract.

PubMed

Stember, Joseph N; Newhouse, Jeffrey; Behr, Gerald; Alam, Shumyle

2017-11-01

Early identification and quantification of bladder damage in pediatric patients with congenital anomalies of the kidney and urinary tract (CAKUT) is crucial to guiding effective treatment and may affect the eventual clinical outcome, including progression of renal disease. We have developed a novel approach based on the convex hull to calculate bladder wall trabecularity in pediatric patients with CAKUT. The objective of this study was to test whether our approach can accurately predict bladder wall irregularity. Twenty pediatric patients, half with renal compromise and CAKUT and half with normal renal function, were evaluated. We applied the convex hull approach to calculate T, a metric proposed to reflect the degree of trabeculation/bladder wall irregularity, in this set of patients. The average T value was roughly 3 times higher for diseased than healthy patients (0.14 [95% confidence interval, 0.10-0.17] versus 0.05 [95% confidence interval, 0.03-0.07] for normal bladders). This disparity was statistically significant (P < .01). We have demonstrated that a convex hull-based procedure can measure bladder wall irregularity. Because bladder damage is a reversible precursor to irreversible renal parenchymal damage, applying such a measure to at-risk pediatric patients can help guide prompt interventions to avert disease progression. © 2017 by the American Institute of Ultrasound in Medicine.

Identification of Termite Species by the Hydrocarbons in their Feces

Treesearch

Michael I. Haverty; R. Joseph Woodrow; Lori J. Nelson; J. Kenneth Grace

2005-01-01

Blends of abundant cuticular hydrocarbons are species-specific for termites (Isoptera) and can be used to identify a given taxon without the diagnostic castes, soldiers or adults. We demonstrate that hydrocarbon extracts of termite fecal pellets from damaged wood can also be characterized and used to identify termites responsible for damage, even though termites are no...

What is extinguished in auditory extinction?

PubMed

Deouell, L Y; Soroker, N

2000-09-11

Extinction is a frequent sequel of brain damage, whereupon patients disregard (extinguish) a contralesional stimulus, and report only the more ipsilesional stimulus, of a pair of stimuli presented simultaneously. We investigated the possibility of a dissociation between the detection and the identification of extinguished phonemes. Fourteen right hemisphere damaged patients with severe auditory extinction were examined using a paradigm that separated the localization of stimuli and the identification of their phonetic content. Patients reported the identity of left-sided phonemes, while extinguishing them at the same time, in the traditional sense of the term. This dissociation suggests that auditory extinction is more about acknowledging the existence of a stimulus in the contralesional hemispace than about the actual processing of the stimulus.

Molecular identification of hard ticks (Ixodes sp.) infesting rodents in Selangor, Malaysia

NASA Astrophysics Data System (ADS)

Ishak, Siti Nabilah; Shiang, Lim Fang; Taib, Farah Shafawati Mohd; Jing, Khoo Jing; Nor, Shukor Md; Yusof, Muhammad Afif; Sah, Shahrul Anuar Mohd; Sitam, Frankie Thomas; Japning, Jeffrine Rovie Ryan

2018-04-01

This study aims to identify hard ticks (Ixodes sp.) infesting rodents in three different sites in Selangor, Malaysia using a molecular approach. A total of 11 individual ticks infesting four different host species (Rattus tiomanicus, Rattus ratus, Maxomys surifer and Sundamys muelleri) were examined based on its morphological features, followed by molecular identification using mitochondrial 16S rDNA gene. Confirmation of the species identity was accomplished by using BLAST program. Clustering analysis based on 16S rDNA sequences was carried out by constructing Neighbour-joining (NJ) and Maximum parsimony (MP) tree using MEGA 7 to clarify the genetic identity of Ixodes sp. Based on morphological features, all individual ticks were only able to be identified up to genus level as most of the samples were fully engorged, damaged and lacked morphological characters. However, molecular analysis of samples revealed 99% similarity with Ixodes granulatus from the GenBank database. Thus, the result of this study showed that all these ticks (Ixodes granulatus) were genetically affiliated to a monophyletic group with highly homogenous sequences.

Predicting threshold and location of laser damage on optical surfaces

DOEpatents

Siekhaus, Wigbert

1987-01-01

An apparatus useful in the prediction of the damage threshold of various optical devices, the location of weak spots on such devices and the location, identification, and elimination of optical surface impurities comprising, a focused and pulsed laser, an photo electric detector/imaging means, and a timer. The weak spots emit photoelectrons when subjected to laser intensities that are less than the intensity actually required to produce the damage. The weak spots may be eliminated by sustained exposure to the laser beam.

Gearbox damage identification and quantification using stochastic resonance

NASA Astrophysics Data System (ADS)

Mba, Clement U.; Marchesiello, Stefano; Fasana, Alessandro; Garibaldi, Luigi

2018-03-01

Amongst the many new tools used for vibration based mechanical fault diagnosis in rotating machineries, stochastic resonance (SR) has been shown to be able to identify as well as quantify gearbox damage via numerical simulations. To validate the numerical simulation results that were obtained in a previous work by the authors, SR is applied in the present study to data from an experimental gearbox that is representative of an industrial gearbox. Both spur and helical gears are used in the gearbox setup. While the results of the direct application of SR to experimental data do not exactly corroborate the numerical simulation results, applying SR to experimental data in pre-processed form is shown to be quite effective. In addition, it is demonstrated that traditional statistical techniques used for gearbox diagnosis can be used as a reference to check how well SR performs.

Structural control and health monitoring of building structures with unknown ground excitations: Experimental investigation

NASA Astrophysics Data System (ADS)

He, Jia; Xu, You-Lin; Zhan, Sheng; Huang, Qin

2017-03-01

When health monitoring system and vibration control system both are required for a building structure, it will be beneficial and cost-effective to integrate these two systems together for creating a smart building structure. Recently, on the basis of extended Kalman filter (EKF), a time-domain integrated approach was proposed for the identification of structural parameters of the controlled buildings with unknown ground excitations. The identified physical parameters and structural state vectors were then utilized to determine the control force for vibration suppression. In this paper, the possibility of establishing such a smart building structure with the function of simultaneous damage detection and vibration suppression was explored experimentally. A five-story shear building structure equipped with three magneto-rheological (MR) dampers was built. Four additional columns were added to the building model, and several damage scenarios were then simulated by symmetrically cutting off these columns in certain stories. Two sets of earthquakes, i.e. Kobe earthquake and Northridge earthquake, were considered as seismic input and assumed to be unknown during the tests. The structural parameters and the unknown ground excitations were identified during the tests by using the proposed identification method with the measured control forces. Based on the identified structural parameters and system states, a switching control law was employed to adjust the current applied to the MR dampers for the purpose of vibration attenuation. The experimental results show that the presented approach is capable of satisfactorily identifying structural damages and unknown excitations on one hand and significantly mitigating the structural vibration on the other hand.

Laboratory validation of MEMS-based sensors for post-earthquake damage assessment image

NASA Astrophysics Data System (ADS)

Pozzi, Matteo; Zonta, Daniele; Santana, Juan; Colin, Mikael; Saillen, Nicolas; Torfs, Tom; Amditis, Angelos; Bimpas, Matthaios; Stratakos, Yorgos; Ulieru, Dumitru; Bairaktaris, Dimitirs; Frondistou-Yannas, Stamatia; Kalidromitis, Vasilis

2011-04-01

The evaluation of seismic damage is today almost exclusively based on visual inspection, as building owners are generally reluctant to install permanent sensing systems, due to their high installation, management and maintenance costs. To overcome this limitation, the EU-funded MEMSCON project aims to produce small size sensing nodes for measurement of strain and acceleration, integrating Micro-Electro-Mechanical Systems (MEMS) based sensors and Radio Frequency Identification (RFID) tags in a single package that will be attached to reinforced concrete buildings. To reduce the impact of installation and management, data will be transmitted to a remote base station using a wireless interface. During the project, sensor prototypes were produced by assembling pre-existing components and by developing ex-novo miniature devices with ultra-low power consumption and sensing performance beyond that offered by sensors available on the market. The paper outlines the device operating principles, production scheme and working at both unit and network levels. It also reports on validation campaigns conducted in the laboratory to assess system performance. Accelerometer sensors were tested on a reduced scale metal frame mounted on a shaking table, back to back with reference devices, while strain sensors were embedded in both reduced and full-scale reinforced concrete specimens undergoing increasing deformation cycles up to extensive damage and collapse. The paper assesses the economical sustainability and performance of the sensors developed for the project and discusses their applicability to long-term seismic monitoring.

Discovery of Boolean metabolic networks: integer linear programming based approach.

PubMed

Qiu, Yushan; Jiang, Hao; Ching, Wai-Ki; Cheng, Xiaoqing

2018-04-11

Traditional drug discovery methods focused on the efficacy of drugs rather than their toxicity. However, toxicity and/or lack of efficacy are produced when unintended targets are affected in metabolic networks. Thus, identification of biological targets which can be manipulated to produce the desired effect with minimum side-effects has become an important and challenging topic. Efficient computational methods are required to identify the drug targets while incurring minimal side-effects. In this paper, we propose a graph-based computational damage model that summarizes the impact of enzymes on compounds in metabolic networks. An efficient method based on Integer Linear Programming formalism is then developed to identify the optimal enzyme-combination so as to minimize the side-effects. The identified target enzymes for known successful drugs are then verified by comparing the results with those in the existing literature. Side-effects reduction plays a crucial role in the study of drug development. A graph-based computational damage model is proposed and the theoretical analysis states the captured problem is NP-completeness. The proposed approaches can therefore contribute to the discovery of drug targets. Our developed software is available at " http://hkumath.hku.hk/~wkc/APBC2018-metabolic-network.zip ".

An automatic damage detection algorithm based on the Short Time Impulse Response Function

NASA Astrophysics Data System (ADS)

Auletta, Gianluca; Carlo Ponzo, Felice; Ditommaso, Rocco; Iacovino, Chiara

2016-04-01

Structural Health Monitoring together with all the dynamic identification techniques and damage detection techniques are increasing in popularity in both scientific and civil community in last years. The basic idea arises from the observation that spectral properties, described in terms of the so-called modal parameters (eigenfrequencies, mode shapes, and modal damping), are functions of the physical properties of the structure (mass, energy dissipation mechanisms and stiffness). Damage detection techniques traditionally consist in visual inspection and/or non-destructive testing. A different approach consists in vibration based methods detecting changes of feature related to damage. Structural damage exhibits its main effects in terms of stiffness and damping variation. Damage detection approach based on dynamic monitoring of structural properties over time has received a considerable attention in recent scientific literature. We focused the attention on the structural damage localization and detection after an earthquake, from the evaluation of the mode curvature difference. The methodology is based on the acquisition of the structural dynamic response through a three-directional accelerometer installed on the top floor of the structure. It is able to assess the presence of any damage on the structure providing also information about the related position and severity of the damage. The procedure is based on a Band-Variable Filter, (Ditommaso et al., 2012), used to extract the dynamic characteristics of systems that evolve over time by acting simultaneously in both time and frequency domain. In this paper using a combined approach based on the Fourier Transform and on the seismic interferometric analysis, an useful tool for the automatic fundamental frequency evaluation of nonlinear structures has been proposed. Moreover, using this kind of approach it is possible to improve some of the existing methods for the automatic damage detection providing stable results also during the strong motion phase. This approach helps to overcome the limitation derived from the use of techniques based on simple Fourier Transform that provide good results when the response of the monitored system is stationary, but fails when the system exhibits a non-stationary behaviour. The main advantage derived from the use of the proposed approach for Structural Health Monitoring is based on the simplicity of the interpretation of the nonlinear variations of the fundamental frequency. The proposed methodology has been tested on numerical models of reinforced concrete structures designed for only gravity loads without and with the presence of infill panels. In order to verify the effectiveness of the proposed approach for the automatic evaluation of the fundamental frequency over time, the results of an experimental campaign of shaking table tests conducted at the seismic laboratory of University of Basilicata (SISLAB) have been used. Acknowledgements This study was partially funded by the Italian Civil Protection Department within the project DPC-RELUIS 2015 - RS4 ''Seismic observatory of structures and health monitoring''. References Ditommaso, R., Mucciarelli, M., Ponzo, F.C. (2012) Analysis of non-stationary structural systems by using a band-variable filter. Bulletin of Earthquake Engineering. DOI: 10.1007/s10518-012-9338-y.

Intelligent wear mode identification system for marine diesel engines based on multi-level belief rule base methodology

NASA Astrophysics Data System (ADS)

Yan, Xinping; Xu, Xiaojian; Sheng, Chenxing; Yuan, Chengqing; Li, Zhixiong

2018-01-01

Wear faults are among the chief causes of main-engine damage, significantly influencing the secure and economical operation of ships. It is difficult for engineers to utilize multi-source information to identify wear modes, so an intelligent wear mode identification model needs to be developed to assist engineers in diagnosing wear faults in diesel engines. For this purpose, a multi-level belief rule base (BBRB) system is proposed in this paper. The BBRB system consists of two-level belief rule bases, and the 2D and 3D characteristics of wear particles are used as antecedent attributes on each level. Quantitative and qualitative wear information with uncertainties can be processed simultaneously by the BBRB system. In order to enhance the efficiency of the BBRB, the silhouette value is adopted to determine referential points and the fuzzy c-means clustering algorithm is used to transform input wear information into belief degrees. In addition, the initial parameters of the BBRB system are constructed on the basis of expert-domain knowledge and then optimized by the genetic algorithm to ensure the robustness of the system. To verify the validity of the BBRB system, experimental data acquired from real-world diesel engines are analyzed. Five-fold cross-validation is conducted on the experimental data and the BBRB is compared with the other four models in the cross-validation. In addition, a verification dataset containing different wear particles is used to highlight the effectiveness of the BBRB system in wear mode identification. The verification results demonstrate that the proposed BBRB is effective and efficient for wear mode identification with better performance and stability than competing systems.

Identification of minute damage in composite bridge structures equipped with fiber optic sensors using the location of neutral axis and finite element analysis

NASA Astrophysics Data System (ADS)

Li, Xi; Glisic, Branko

2016-04-01

By definition, the neutral axis of a loaded composite beam structure is the curve along which the section experiences zero bending strain. When no axial loading is present, the location of the neutral axis passes through the centroid of stiffness of the beam cross-section. In the presence of damage, the centroid of stiffness, as well as the neutral axis, shift from the healthy position. The concept of neutral axis can be widely applied to all beam-like structures. According to literature, a change in location of the neutral axis can be associated with damage in the corresponding cross-section. In this paper, the movement of neutral axis near locations of minute damage in a composite bridge structure was studied using finite element analysis and experimental results. The finite element model was developed based on a physical scale model of a composite simply-supported structure with controlled minute damage in the reinforced concrete deck. The structure was equipped with long-gauge fiber optic strain and temperature sensors at a healthy reference location as well as two locations of damage. A total of 12 strain sensors were installed during construction and used to monitor the structure during various loading events. This paper aims to explain previous experimental results which showed that the observed positions of neutral axis near damage locations were higher than the predicted healthy locations in some loading events. Analysis has shown that finite element analysis has potential to simulate and explain the physical behavior of the test structure.

Portable, real-time alloy identification of metallic wear debris from machinery lubrication systems: laser-induced breakdown spectroscopy versus x-ray fluorescence

NASA Astrophysics Data System (ADS)

Suresh, Pooja

2014-05-01

Alloy identification of oil-borne wear debris captured on chip detectors, filters and magnetic plugs allows the machinery maintainer to assess the health of the engine or gearbox and identify specific component damage. Today, such identification can be achieved in real time using portable, at-line laser-induced breakdown spectroscopy (LIBS) and Xray fluorescence (XRF) instruments. Both techniques can be utilized in various industries including aviation, marine, railways, heavy diesel and other industrial machinery with, however, some substantial differences in application and instrument performance. In this work, the performances of a LIBS and an XRF instrument are compared based on measurements of a wide range of typical aerospace alloys including steels, titanium, aluminum and nickel alloys. Measurement results were analyzed with a staged correlation technique specifically developed for the purposes of this study - identifying the particle alloy composition using a pre-recorded library of spectral signatures. The analysis is performed in two stages: first, the base element of the alloy is determined by correlation with the stored elemental spectra and then, the alloy is identified by matching the particle's spectral signature using parametric correlation against the stored spectra of all alloys that have the same base element. The correlation analysis has achieved highly repeatable discrimination between alloys of similar composition. Portable LIBS demonstrates higher detection accuracy and better identification of alloys comprising lighter elements as compared to that of the portable XRF system, and reveals a significant reduction in the analysis time over XRF.

Hazard identification, dose-response and environmental characteristics of stachybotryotoxins and other health-related products from Stachybotrys.

PubMed

Lai, K M

2006-03-01

An extensive growth of Stachybotrys in water-damaged buildings is of great public health concern. It is inconclusive whether Stachybotrys is responsible for the reported health effects on the occupants in these contaminated environments. However, based on the veterinary, occupational and laboratory toxicity studies, it is reasonable to project that Stachybotrys can cause adverse health responses once the toxic level of the corresponding agents reached the target systems. In order to assess the risk to occupants in contaminated buildings, it is essential to outline and collect information for risk assessment. This review paper presents the current information in the format of hazard identification, dose-response and environmental characteristics and aims to discuss existing information with researchers and risk assessors and help to conduct risk characterization under different indoor conditions.

Signal Construction-Based Dispersion Compensation of Lamb Waves Considering Signal Waveform and Amplitude Spectrum Preservation

PubMed Central

Cai, Jian; Yuan, Shenfang; Wang, Tongguang

2016-01-01

The results of Lamb wave identification for the aerospace structures could be easily affected by the nonlinear-dispersion characteristics. In this paper, dispersion compensation of Lamb waves is of particular concern. Compared with the similar research works on the traditional signal domain transform methods, this study is based on signal construction from the viewpoint of nonlinear wavenumber linearization. Two compensation methods of linearly-dispersive signal construction (LDSC) and non-dispersive signal construction (NDSC) are proposed. Furthermore, to improve the compensation effect, the influence of the signal construction process on the other crucial signal properties, including the signal waveform and amplitude spectrum, is considered during the investigation. The linear-dispersion and non-dispersion effects are firstly analyzed. Then, after the basic signal construction principle is explored, the numerical realization of LDSC and NDSC is discussed, in which the signal waveform and amplitude spectrum preservation is especially regarded. Subsequently, associated with the delay-and-sum algorithm, LDSC or NDSC is employed for high spatial resolution damage imaging, so that the adjacent multi-damage or quantitative imaging capacity of Lamb waves can be strengthened. To verify the proposed signal construction and damage imaging methods, the experimental and numerical validation is finally arranged on the aluminum plates. PMID:28772366

Signal Construction-Based Dispersion Compensation of Lamb Waves Considering Signal Waveform and Amplitude Spectrum Preservation.

PubMed

Cai, Jian; Yuan, Shenfang; Wang, Tongguang

2016-12-23

The results of Lamb wave identification for the aerospace structures could be easily affected by the nonlinear-dispersion characteristics. In this paper, dispersion compensation of Lamb waves is of particular concern. Compared with the similar research works on the traditional signal domain transform methods, this study is based on signal construction from the viewpoint of nonlinear wavenumber linearization. Two compensation methods of linearly-dispersive signal construction (LDSC) and non-dispersive signal construction (NDSC) are proposed. Furthermore, to improve the compensation effect, the influence of the signal construction process on the other crucial signal properties, including the signal waveform and amplitude spectrum, is considered during the investigation. The linear-dispersion and non-dispersion effects are firstly analyzed. Then, after the basic signal construction principle is explored, the numerical realization of LDSC and NDSC is discussed, in which the signal waveform and amplitude spectrum preservation is especially regarded. Subsequently, associated with the delay-and-sum algorithm, LDSC or NDSC is employed for high spatial resolution damage imaging, so that the adjacent multi-damage or quantitative imaging capacity of Lamb waves can be strengthened. To verify the proposed signal construction and damage imaging methods, the experimental and numerical validation is finally arranged on the aluminum plates.

Identification of the formation phases of filamentary damage induced by nanosecond laser pulses in bulk fused silica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Chao; Xu, Zhongjie; Chambonneau, Maxime, E-mail: chambonneau@lp3.univ-mrs.fr, E-mail: jiangtian198611@163.com

2015-09-14

Employing a pump-probe polarization-based two-frame shadowgraphy setup, the formation of filamentary damage induced in bulk fused silica by a nanosecond pulse at 1064 nm is investigated with a picosecond probe. Three different phases are exhibited in the damage experiments. The first phase is the formation of a micrometric plasma channel along the laser direction during the beginning of the pulse likely caused by multi-photon ionization. This channel exhibits growth during ∼400 ps, and the newly grown plasma is discrete. Then, during the end of the pulse, this channel evolves into a tadpole-like morphology showing an elliptical head upstream the laser fluxmore » followed by a thin tail. This observed asymmetry is attributed to shielding effects caused by both the plasma and hot modified silica. Once the damage shows its almost final morphology, a last phase consists in the launch of a pressure wave enlarging it after the laser pulse. The physical mechanisms that might be involved in the formation of plasma channels are discussed. The experimental data are first confronted to the moving breakdown model which overestimates the filamentary damage length. Finally, taking into account the temporal shape of the laser pulses, the coupling between Kerr-induced self-focusing and stimulated Brillouin scattering is discussed to interpret the observations.« less

Identification and Characterization of Trichoderma Species Damaging Shiitake Mushroom Bed-Logs Infested by Camptomyia Pest.

PubMed

Kim, Jun Young; Kwon, Hyuk Woo; Yun, Yeo Hong; Kim, Seong Hwan

2016-05-28

The shiitake mushroom industry has suffered from Camptomyia (gall midges) pest, which feeds on the mycelium of shiitake mushroom during its cultivation. It has been postulated that fungal damage of shiitake bed-logs is associated with infestation by the insect pest, but this is not well understood. To understand the fungal damage associated with Camptomyia pest, various Trichoderma species were isolated, identified, and characterized. In addition to two previously known Trichoderma species, T. citrinoviride and T. deliquescens, two other Trichoderma species, T. harzianum and T. atroviride, were newly identified from the pestinfested bed-log samples obtained at three mushroom farms in Cheonan, Korea. Among these four species, T. harzianum was the most evident. The results of a chromogenic media-based assay for extracellular enzymes showed that these four species have the ability to produce amylase, carboxyl-methyl cellulase, avicelase, pectinase, and β-glucosidase, thus indicating that they can degrade wood components. A dual culture assay on PDA indicated that T. harzianum, T. atroviride, and T. citrinoviride were antagonistic against the mycelial growth of a shiitake strain (Lentinula edodes). Inoculation tests on shiitake bed-logs revealed that all four species were able to damage the wood of bed-logs. Our results provide evidence that the four green mold species are the causal agents involved in fungal damage of shiitake bed-logs infested by Camptomyia pest.

Damage Evaluation for Ti Alloys in Creep based on Incompatibility Field Measurement via EBSD Technique and Micro-Pillar Experiments Toward Identification of Roles of Dislocation Substructures on Fatigue Crack Initiation

DTIC Science & Technology

2011-02-07

Reproduction of a slip band with a PSB -ladder-like internal structure is attempted assuming initial conditions with and without corresponding strain...into heat at the PSB region, the present study extensively examined possible transition mechanisms toward the growth of grooves thereabout and that...arrangements even with the same dislocation density. (2)A slip band-like region having a substructure mimicking PSB ladder is demonstrated to be

Disaster Impact Across Cultural Groups: Comparison of Whites, African Americans, and Latinos

PubMed Central

Price, Matthew; McCauley, Jenna L.; Ruggiero, Kenneth J.

2015-01-01

The current study extends knowledge regarding the differential impact of natural disasters among White, African American, and Latino survivors of Hurricane Ike through its use of a large, regional sample recruited via representative sampling procedures to examine the associations between cultural identification and disaster impact, including loss, damage, and negative mental health outcomes. Consistent with previous research, results indicated disparities between cultural groups with regard to disaster exposure. Additionally, type of disaster impact was differentially associated with PTSD and depression status dependent on cultural group. Specifically, the extent of personal disaster exposure, property damage, and loss of services made significant contributions to PTSD status among White survivors. African-Americans were more likely than White and Latino Ike survivors to endorse post-disaster PTSD and depression and endorsement of depression was predicted by severity of property damage. With respect to Latino respondents, only the extent of personal disaster exposure significantly contributed to both PTSD and depression status. Implications of the current findings are discussed with regard to future disaster preparedness and response efforts and the implementation and evaluation of community-based disaster resources. PMID:23709270

Impaired integration of object knowledge and visual input in a case of ventral simultanagnosia with bilateral damage to area V4.

PubMed

Leek, E Charles; d'Avossa, Giovanni; Tainturier, Marie-Josèphe; Roberts, Daniel J; Yuen, Sung Lai; Hu, Mo; Rafal, Robert

2012-01-01

This study examines how brain damage can affect the cognitive processes that support the integration of sensory input and prior knowledge during shape perception. It is based on the first detailed study of acquired ventral simultanagnosia, which was found in a patient (M.T.) with posterior occipitotemporal lesions encompassing V4 bilaterally. Despite showing normal object recognition for single items in both accuracy and response times (RTs), and intact low-level vision assessed across an extensive battery of tests, M.T. was impaired in object identification with overlapping figures displays. Task performance was modulated by familiarity: Unlike controls, M.T. was faster with overlapping displays of abstract shapes than with overlapping displays of common objects. His performance with overlapping common object displays was also influenced by both the semantic relatedness and visual similarity of the display items. These findings challenge claims that visual perception is driven solely by feedforward mechanisms and show how brain damage can selectively impair high-level perceptual processes supporting the integration of stored knowledge and visual sensory input.

Polygalacturonase Causes Lygus-like Damage on Plants: Cloning and Identification of Western Tarnished Plant Bug (Lygus hesperus) Polygalacturonases Secreted During Feeding

USDA-ARS?s Scientific Manuscript database

Abstract: Polygalacturonase (PG), an enzyme that degrades pectin within the plant tissue cell wall, has been postulated as the chemical cause of damage to plants by the mirid Lygus hesperus. Micro-injection of two pure recombinant Aspergillus niger PG II protein forms, the wild type enzymically acti...

Building Damage Extraction Triggered by Earthquake Using the Uav Imagery

NASA Astrophysics Data System (ADS)

Li, S.; Tang, H.

2018-04-01

When extracting building damage information, we can only determine whether the building is collapsed using the post-earthquake satellite images. Even the satellite images have the sub-meter resolution, the identification of slightly damaged buildings is still a challenge. As the complementary data to satellite images, the UAV images have unique advantages, such as stronger flexibility and higher resolution. In this paper, according to the spectral feature of UAV images and the morphological feature of the reconstructed point clouds, the building damage was classified into four levels: basically intact buildings, slightly damaged buildings, partially collapsed buildings and totally collapsed buildings, and give the rules of damage grades. In particular, the slightly damaged buildings are determined using the detected roof-holes. In order to verify the approach, we conduct experimental simulations in the cases of Wenchuan and Ya'an earthquakes. By analyzing the post-earthquake UAV images of the two earthquakes, the building damage was classified into four levels, and the quantitative statistics of the damaged buildings is given in the experiments.

PCR-Based Identification and Characterization of Fusarium sp. Associated with Mango Malformation

PubMed Central

Arif, M.; Pani, D. R.; Zaidi, N. W.; Singh, U. S.

2011-01-01

Mango malformation is the most serious disease of mango causing considerable damage to the mango orchards worldwide. It is a major threat for mango cultivation in north Indian belt. In recent years, Fusarium sp. is finding wide acceptability in scientific community as a causal agent of this disease. However, little information is known about the variability in Fusarium isolates from malformed mango tissues. Therefore, the major objective of present study was the identification and analysis of genetic diversity among Fusarium isolates collected from malformed mango tissues. Two texon selective primers, ITS-Fu-f and ITS-Fu-r, were used for quick identification of Fusarium spp. The fungal genomic DNA was extracted from using CTAB method and was utilized as template for PCR amplification. Total 224 bands were amplified by 18 RAPD primers at an average of 12.44 bands per primer. The size of the obtained amplicons ranged from 0.264 kb (minimum) to 3.624 kb (maximum). Data scored from 25 isolates of Fusarium sp. with 18 RAPD primers were used to generate similarity coefficients. The similarity coefficient ranged from 0.17 to 0.945. Based on DNA fingerprints, all isolates were categorized into two major clusters. This study indicated a wide variability among different isolates of Fusarium. PMID:21350657

Predicting threshold and location of laser damage on optical surfaces

DOEpatents

Siekhaus, W.

1985-02-04

Disclosed is an apparatus useful in the prediction of the damage threshold of various optical devices, the location of weak spots on such devices and the location, identification, and elimination of optical surface impurities. The apparatus comprises a focused and pulsed laser, a photo electric detector/imaging means, and a timer. The weak spots emit photoelectrons when subjected to laser intensities that are less than the intensity actually required to produce the damage. The weak spots may be eliminated by sustained exposure to the laser beam.

A Brainnetome Atlas Based Mild Cognitive Impairment Identification Using Hurst Exponent

PubMed Central

Long, Zhuqing; Jing, Bin; Guo, Ru; Li, Bo; Cui, Feiyi; Wang, Tingting; Chen, Hongwen

2018-01-01

Mild cognitive impairment (MCI), which generally represents the transition state between normal aging and the early changes related to Alzheimer’s disease (AD), has drawn increasing attention from neuroscientists due that efficient AD treatments need early initiation ahead of irreversible brain tissue damage. Thus effective MCI identification methods are desperately needed, which may be of great importance for the clinical intervention of AD. In this article, the range scaled analysis, which could effectively detect the temporal complexity of a time series, was utilized to calculate the Hurst exponent (HE) of functional magnetic resonance imaging (fMRI) data at a voxel level from 64 MCI patients and 60 healthy controls (HCs). Then the average HE values of each region of interest (ROI) in brainnetome atlas were extracted and compared between MCI and HC. At last, the abnormal average HE values were adopted as the classification features for a proposed support vector machine (SVM) based identification algorithm, and the classification performance was estimated with leave-one-out cross-validation (LOOCV). Our results indicated 83.1% accuracy, 82.8% sensitivity and 83.3% specificity, and an area under curve of 0.88, suggesting that the HE index could serve as an effective feature for the MCI identification. Furthermore, the abnormal HE brain regions in MCI were predominately involved in left middle frontal gyrus, right hippocampus, bilateral parahippocampal gyrus, bilateral amygdala, left cingulate gyrus, left insular gyrus, left fusiform gyrus, left superior parietal gyrus, left orbital gyrus and left basal ganglia. PMID:29692721

Biomaterial-based delivery for skeletal muscle repair

PubMed Central

Cezar, Christine A.; Mooney, David J.

2015-01-01

Skeletal muscle possesses a remarkable capacity for regeneration in response to minor damage, but severe injury resulting in a volumetric muscle loss can lead to extensive and irreversible fibrosis, scarring, and loss of muscle function. In early clinical trials, the intramuscular injection of cultured myoblasts was proven to be a safe but ineffective cell therapy, likely due to rapid death, poor migration, and immune rejection of the injected cells. In recent years, appropriate therapeutic cell types and culturing techniques have improved progenitor cell engraftment upon transplantation. Importantly, the identification of several key biophysical and biochemical cues that synergistically regulate satellite cell fate has paved the way for the development of cell-instructive biomaterials that serve as delivery vehicles for cells to promote in vivo regeneration. Material carriers designed to spatially and temporally mimic the satellite cell niche may be of particular importance for the complete regeneration of severely damaged skeletal muscle. PMID:25271446

Consensus statement for diagnosis of subcortical small vessel disease

PubMed Central

Wallin, Anders; Wardlaw, Joanna M; Markus, Hugh S; Montaner, Joan; Wolfson, Leslie; Iadecola, Costantino; Zlokovic, Berislav V; Joutel, Anne; Dichgans, Martin; Duering, Marco; Schmidt, Reinhold; Korczyn, Amos D; Grinberg, Lea T; Chui, Helena C; Hachinski, Vladimir

2016-01-01

Vascular cognitive impairment (VCI) is the diagnostic term used to describe a heterogeneous group of sporadic and hereditary diseases of the large and small blood vessels. Subcortical small vessel disease (SVD) leads to lacunar infarcts and progressive damage to the white matter. Patients with progressive damage to the white matter, referred to as Binswanger’s disease (BD), constitute a spectrum from pure vascular disease to a mixture with neurodegenerative changes. Binswanger’s disease patients are a relatively homogeneous subgroup with hypoxic hypoperfusion, lacunar infarcts, and inflammation that act synergistically to disrupt the blood–brain barrier (BBB) and break down myelin. Identification of this subgroup can be facilitated by multimodal disease markers obtained from clinical, cerebrospinal fluid, neuropsychological, and imaging studies. This consensus statement identifies a potential set of biomarkers based on underlying pathologic changes that could facilitate diagnosis and aid patient selection for future collaborative treatment trials. PMID:26198175

Damage identification of supporting structures with a moving sensory system

NASA Astrophysics Data System (ADS)

Zhu, X. Q.; Law, S. S.; Huang, L.; Zhu, S. Y.

2018-02-01

An innovative approach to identify local anomalies in a structural beam bridge with an instrumented vehicle moving as a sensory system across the bridge. Accelerations at both the axle and vehicle body are measured from which vehicle-bridge interaction force on the structure is determined. Local anomalies of the structure are estimated from this interaction force with the Newton's iterative method basing on the homotopy continuation method. Numerical results with the vehicle moving over simply supported or continuous beams show that the acceleration responses from the vehicle or the bridge structure are less sensitive to the local damages than the interaction force between the wheel and the structure. Effects of different movement patterns and moving speed of the vehicle are investigated, and the effect of measurement noise on the identified results is discussed. A heavier or slower vehicle has been shown to be less sensitive to measurement noise giving more accurate results.

Vulnerability and seismic damage scenarios for Barcelona (Spain) by using GIS

NASA Astrophysics Data System (ADS)

Lantada, N.; Pujades, L. G.; Barbat, A.

2003-04-01

An integrated GIS-based analysis (using ArcView GIS) is performed in order to estimate damage scenarios for VI, VII and VIII EMS-98 seismic intensities in Barcelona (Spain). The analysis of vulnerability and damage of individual buildings is performed according to a simplified method developed by Giovanazzi and Lagomarsino at the University of Genoa (Italy). An index of average vulnerability is associated to each building typology, which may be refined on the basis of behaviour modifiers. The index allows identification of an analytical relationship between seismic input (intensity) and damage, described by a binomial distribution. This methodology, which is based on the EMS-98 building typologies and preserves the compatibility with preceding methods, is applied to the two main residential building typologies of Barcelona, that is, unreinforced masonry and reinforced concrete buildings. Then, the specific residential buildings of Barcelona are classified in different groups characterized by a similar seismic behaviour. Therefore, all buildings belonging to each typology are cast in the most probable class according to vulnerability. In this way, the average vulnerability index is associated to each building typology of Barcelona and it is refined later on the basis of behaviour modifiers, linked to the number of stories, the year of construction and their state of maintenance. The ability of GIS tools to store, manage, analyse, and display the large amount of spatial and tabular data involved in this study allows to map average vulnerability indexes, and damage for the entire city. That is, vulnerability and damage scenarios. The obtained results show a high vulnerability and high expected seismic damage. For a VI degree of intensity, the maximum expected damage is in the range 15-30 % in the oldest zones of the city, the downtown, while for intensity VII it is in the range 45-60%. The developed GIS tool involves a friendly interface that allows new models and database information to be included in the same framework. As a new step to the seismic risk assessment, and in addition to the building characteristics, the destination of the building, as well as the essential buildings, and the density of population for census zones, have been included in the GIS database. Combining this information with the previous damage maps we will be able to obtain more complete damage scenarios including, deaths, injuries, and homeless.

Forensic odontology, part 3. The Australian bushfires - Victoria state, February 2009.

PubMed

Hinchliffe, J

2011-04-09

This paper aims to demonstrate the stages in the disaster victim identification of those who lost their lives in the Australian bushfires that raged across the state of Victoria in February 2009. Communities were damaged or destroyed leaving families distressed and homeless, and as the number of deaths increased the Disaster Victim Identification (DVI) teams were activated, with plans evolving to deal with this emergency. The identification process was challenging due to many factors, such as the dangers and difficulties involved in body recovery and the charring and commingling of remains. It would take several months of careful work to identify the dead using a multidisciplinary approach. The impact of this incident will have long-lasting consequences for the families and communities involved. At the time of writing all but one of the 173 victims had been identified, mostly by dental methods: quite remarkable when only small fragments of the dental structures remained in many cases. This article is based on the author's personal experience working to assist the organised and experienced Australian Dental DVI Team.

Technologies for developing an advanced intelligent ATM with self-defence capabilities

NASA Astrophysics Data System (ADS)

Sako, Hiroshi

2010-01-01

We have developed several technologies for protecting automated teller machines. These technologies are based mainly on pattern recognition and are used to implement various self-defence functions. They include (i) banknote recognition and information retrieval for preventing machines from accepting counterfeit and damaged banknotes and for retrieving information about detected counterfeits from a relational database, (ii) form processing and character recognition for preventing machines from accepting remittance forms without due dates and/or insufficient payment, (iii) person identification to prevent machines from transacting with non-customers, and (iv) object recognition to guard machines against foreign objects such as spy cams that might be surreptitiously attached to them and to protect users against someone attempting to peek at their user information such as their personal identification number. The person identification technology has been implemented in most ATMs in Japan, and field tests have demonstrated that the banknote recognition technology can recognise more then 200 types of banknote from 30 different countries. We are developing an "advanced intelligent ATM" that incorporates all of these technologies.

Dynamic Structural Fault Detection and Identification

NASA Technical Reports Server (NTRS)

Smith, Timothy; Reichenbach, Eric; Urnes, James M.

2009-01-01

Aircraft structures are designed to guarantee safety of flight in some required operational envelope. When the aircraft becomes structurally impaired, safety of flight may not be guaranteed within that previously safe operational envelope. In this case the safe operational envelope must be redefined in-flight and a means to prevent excursion from this new envelope must be implemented. A specific structural failure mode that may result in a reduced safe operating envelope, the exceedance of which could lead to catastrophic structural failure of the aircraft, will be addressed. The goal of the DFEAP program is the detection of this failure mode coupled with flight controls adaptation to limit critical loads in the damaged aircraft structure. The DFEAP program is working with an F/A-18 aircraft model. The composite wing skins are bonded to metallic spars in the wing substructure. Over time, it is possible that this bonding can deteriorate due to fatigue. In this case, the ability of the wing spar to transfer loading between the wing skins is reduced. This failure mode can translate to a reduced allowable compressive strain on the wing skin and could lead to catastrophic wing buckling if load limiting of the wing structure is not applied. The DFEAP program will make use of a simplified wing strain model for the healthy aircraft. The outputs of this model will be compared in real-time to onboard strain measurements at several locations on the aircraft wing. A damage condition is declared at a given location when the strain measurements differ sufficiently from the strain model. Parameter identification of the damaged structure wing strain parameters will be employed to provide load limiting control adaptation for the aircraft. This paper will discuss the simplified strain models used in the implementation and their interaction with the strain sensor measurements. Also discussed will be the damage detection and identification schemes employed and the means by which the damaged aircraft parameters will be used to provide load limiting that keeps the aircraft within the safe operational envelope.

Concealed identification symbols and nondestructive determination of the identification symbols

DOEpatents

Nance, Thomas A.; Gibbs, Kenneth M.

2014-09-16

The concealing of one or more identification symbols into a target object and the subsequent determination or reading of such symbols through non-destructive testing is described. The symbols can be concealed in a manner so that they are not visible to the human eye and/or cannot be readily revealed to the human eye without damage or destruction of the target object. The identification symbols can be determined after concealment by e.g., the compilation of multiple X-ray images. As such, the present invention can also provide e.g., a deterrent to theft and the recovery of lost or stolen objects.

Health monitoring of pipeline girth weld using empirical mode decomposition

NASA Astrophysics Data System (ADS)

Rezaei, Davood; Taheri, Farid

2010-05-01

In the present paper the Hilbert-Huang transform (HHT), as a time-series analysis technique, has been combined with a local diagnostic approach in an effort to identify flaws in pipeline girth welds. This method is based on monitoring the free vibration signals of the pipe at its healthy and flawed states, and processing the signals through the HHT and its associated signal decomposition technique, known as empirical mode decomposition (EMD). The EMD method decomposes the vibration signals into a collection of intrinsic mode functions (IMFs). The deviations in structural integrity, measured from a healthy-state baseline, are subsequently evaluated by two damage sensitive parameters. The first is a damage index, referred to as the EM-EDI, which is established based on an energy comparison of the first or second IMF of the vibration signals, before and after occurrence of damage. The second parameter is the evaluation of the lag in instantaneous phase, a quantity derived from the HHT. In the developed methodologies, the pipe's free vibration is monitored by piezoceramic sensors and a laser Doppler vibrometer. The effectiveness of the proposed techniques is demonstrated through a set of numerical and experimental studies on a steel pipe with a mid-span girth weld, for both pressurized and nonpressurized conditions. To simulate a crack, a narrow notch is cut on one side of the girth weld. Several damage scenarios, including notches of different depths and at various locations on the pipe, are investigated. Results from both numerical and experimental studies reveal that in all damage cases the sensor located at the notch vicinity could successfully detect the notch and qualitatively predict its severity. The effect of internal pressure on the damage identification method is also monitored. Overall, the results are encouraging and promise the effectiveness of the proposed approaches as inexpensive systems for structural health monitoring purposes.

Variable input observer for structural health monitoring of high-rate systems

NASA Astrophysics Data System (ADS)

Hong, Jonathan; Laflamme, Simon; Cao, Liang; Dodson, Jacob

2017-02-01

The development of high-rate structural health monitoring methods is intended to provide damage detection on timescales of 10 µs -10ms where speed of detection is critical to maintain structural integrity. Here, a novel Variable Input Observer (VIO) coupled with an adaptive observer is proposed as a potential solution for complex high-rate problems. The VIO is designed to adapt its input space based on real-time identification of the system's essential dynamics. By selecting appropriate time-delayed coordinates defined by both a time delay and an embedding dimension, the proper input space is chosen which allows more accurate estimations of the current state and a reduction of the convergence rate. The optimal time-delay is estimated based on mutual information, and the embedding dimension is based on false nearest neighbors. A simulation of the VIO is conducted on a two degree-of-freedom system with simulated damage. Results are compared with an adaptive Luenberger observer, a fixed time-delay observer, and a Kalman Filter. Under its preliminary design, the VIO converges significantly faster than the Luenberger and fixed observer. It performed similarly to the Kalman Filter in terms of convergence, but with greater accuracy.

Crack identification for reinforced concrete using PZT based smart rebar active sensing diagnostic network

NASA Astrophysics Data System (ADS)

Song, N. N.; Wu, F.

2016-04-01

An active sensing diagnostic system using PZT based smart rebar for SHM of RC structure has been currently under investigation. Previous test results showed that the system could detect the de-bond of concrete from reinforcement, and the diagnostic signals were increased exponentially with the de-bonding size. Previous study also showed that the smart rebar could function well like regular reinforcement to undertake tension stresses. In this study, a smart rebar network has been used to detect the crack damage of concrete based on guided waves. Experimental test has been carried out for the study. In the test, concrete beams with 2 reinforcements have been built. 8 sets of PZT elements were mounted onto the reinforcement bars in an optimized way to form an active sensing diagnostic system. A 90 kHz 5-cycle Hanning-windowed tone burst was used as input. Multiple cracks have been generated on the concrete structures. Through the guided bulk waves propagating in the structures from actuators and sensors mounted from different bars, crack damage could be detected clearly. Cases for both single and multiple cracks were tested. Different crack depths from the surface and different crack numbers have been studied. Test result shows that the amplitude of sensor output signals is deceased linearly with a propagating crack, and is decreased exponentially with increased crack numbers. From the study, the active sensing diagnostic system using PZT based smart rebar network shows a promising way to provide concrete crack damage information through the "talk" among sensors.

Damage Precursor Identification via Microstructure-Sensitive Nondestructive Evaluation

NASA Astrophysics Data System (ADS)

Wisner, Brian John

Damage in materials is a complex and stochastic process bridging several time and length scales. This dissertation focuses on investigating the damage process in a particular class of precipitate-hardened aluminum alloys which is widely used in automotive and aerospace applications. Most emphasis in the literature has been given either on their ductility for manufacturing purposes or fracture for performance considerations. In this dissertation, emphasis is placed on using nondestructive evaluation (NDE) combined with mechanical testing and characterization methods applied at a scale where damage incubation and initiation is occurring. Specifically, a novel setup built inside a Scanning Electron Microscope (SEM) and retrofitted to be combined with characterization and NDE capabilities was developed with the goal to track the early stages of the damage process in this type of material. The characterization capabilities include Electron Backscatter Diffraction (EBSD) and Energy Dispersive Spectroscopy (EDS) in addition to X-ray micro-computed tomography (μ-CT) and nanoindentation, in addition to microscopy achieved by the Secondary Electron (SE) and Back Scatter Electron (BSE) detectors. The mechanical testing inside the SEM was achieved with the use of an appropriate stage that fitted within its chamber and is capable of applying both axial and bending monotonic and cyclic loads. The NDE capabilities, beyond the microscopy and μ-CT, include the methods of Acoustic Emission and Digital Image Correlation (DIC). This setup was used to identify damage precursors in this material system and their evolution over time and space. The experimental results were analyzed by a custom signal processing scheme that involves both feature-based analyses as well as a machine learning method to relate recorded microstructural data to damage in this material. Extensions of the presented approach to include information from computational methods as well as its applicability to other material systems are discussed.

Compressive sensing for efficient health monitoring and effective damage detection of structures

NASA Astrophysics Data System (ADS)

Jayawardhana, Madhuka; Zhu, Xinqun; Liyanapathirana, Ranjith; Gunawardana, Upul

2017-02-01

Real world Structural Health Monitoring (SHM) systems consist of sensors in the scale of hundreds, each sensor generating extremely large amounts of data, often arousing the issue of the cost associated with data transfer and storage. Sensor energy is a major component included in this cost factor, especially in Wireless Sensor Networks (WSN). Data compression is one of the techniques that is being explored to mitigate the effects of these issues. In contrast to traditional data compression techniques, Compressive Sensing (CS) - a very recent development - introduces the means of accurately reproducing a signal by acquiring much less number of samples than that defined by Nyquist's theorem. CS achieves this task by exploiting the sparsity of the signal. By the reduced amount of data samples, CS may help reduce the energy consumption and storage costs associated with SHM systems. This paper investigates CS based data acquisition in SHM, in particular, the implications of CS on damage detection and localization. CS is implemented in a simulation environment to compress structural response data from a Reinforced Concrete (RC) structure. Promising results were obtained from the compressed data reconstruction process as well as the subsequent damage identification process using the reconstructed data. A reconstruction accuracy of 99% could be achieved at a Compression Ratio (CR) of 2.48 using the experimental data. Further analysis using the reconstructed signals provided accurate damage detection and localization results using two damage detection algorithms, showing that CS has not compromised the crucial information on structural damages during the compression process.

Seismic damage diagnosis of a masonry building using short-term damping measurements

NASA Astrophysics Data System (ADS)

Kouris, Leonidas Alexandros S.; Penna, Andrea; Magenes, Guido

2017-04-01

It is of considerable importance to perform dynamic identification and detect damage in existing structures. This paper describes a new and practical method for damage diagnosis of masonry buildings requiring minimum computational effort. The method is based on the relative variation of modal damping and validated against experimental data from a full scale two storey shake table test. The experiment involves a building subjected to uniaxial vibrations of progressively increasing intensity at the facilities of EUCENTRE laboratory (Pavia, Italy) up to a near collapse damage state. Five time-histories are applied scaling the Montenegro (1979) accelerogram. These strong motion tests are preceded by random vibration tests (RVT's) which are used to perform modal analysis. Two deterministic methods are applied: the single degree of freedom (SDOF) assumption together with the peak-picking method in the discrete frequency domain and the Eigen realisation algorithm with data correlations (ERA-DC) in the discrete time domain. Regarding the former procedure, some improvements are incorporated to locate rigorously the natural frequencies and estimate the modal damping. The progressive evolution of the modal damping is used as a key indicator to characterise damage on the building. Modal damping is connected to the structural mass and stiffness. A square integrated but only with two components expression for proportional (classical) damping is proposed to fit better with the experimental measurements of modal damping ratios. Using this Rayleigh order formulation the contribution of each of the damping components is evaluated. The stiffness component coefficient is proposed as an effective index to detect damage and quantify its intensity.

CON4EI: Development of testing strategies for hazard identification and labelling for serious eye damage and eye irritation of chemicals.

PubMed

Adriaens, E; Verstraelen, S; Alépée, N; Kandarova, H; Drzewiecka, A; Gruszka, K; Guest, R; Willoughby, J A; Van Rompay, A R

2018-06-01

Assessment of acute eye irritation potential is part of the international regulatory requirements for safety testing of chemicals. In the last decades, many efforts have been made in the search for alternative methods to replace the regulatory in vivo Draize rabbit eye test (OECD TG 405). Success in terms of complete replacement of the regulatory in vivo Draize rabbit eye test has not yet been achieved. The main objective of the CEFIC-LRI-AIMT6-VITO CON4EI (CONsortium for in vitro Eye Irritation testing strategy) project was to develop tiered testing strategies for serious eye damage and eye irritation assessment that can lead to complete replacement of OECD TG 405. A set of 80 reference chemicals (e.g. balanced by important driver of classification and physical state), was tested with seven test methods. Based on the results of this project, three different strategies were suggested. We have provided a standalone (EpiOcular ET-50), a two-tiered and three-tiered strategy, that can be used to distinguish between Cat 1 and Cat 2 chemicals and chemicals that do not require classification (No Cat). The two-tiered and three-tiered strategies use an RhCE test method (EpiOcular EIT or SkinEthic™ EIT) at the bottom (identification No Cat) in combination with the BCOP LLBO (two-tiered strategy) or BCOP OP-KIT and SMI (three-tiered strategy) at the top (identification Cat 1). For our proposed strategies, 71.1% - 82.9% Cat 1, 64.2% - 68.5% Cat 2 and ≥80% No Cat chemicals were correctly identified. Also, similar results were obtained for the Top-Down and Bottom-Up approach. Copyright © 2017 Elsevier Ltd. All rights reserved.

A refined Frequency Domain Decomposition tool for structural modal monitoring in earthquake engineering

NASA Astrophysics Data System (ADS)

Pioldi, Fabio; Rizzi, Egidio

2017-07-01

Output-only structural identification is developed by a refined Frequency Domain Decomposition ( rFDD) approach, towards assessing current modal properties of heavy-damped buildings (in terms of identification challenge), under strong ground motions. Structural responses from earthquake excitations are taken as input signals for the identification algorithm. A new dedicated computational procedure, based on coupled Chebyshev Type II bandpass filters, is outlined for the effective estimation of natural frequencies, mode shapes and modal damping ratios. The identification technique is also coupled with a Gabor Wavelet Transform, resulting in an effective and self-contained time-frequency analysis framework. Simulated response signals generated by shear-type frames (with variable structural features) are used as a necessary validation condition. In this context use is made of a complete set of seismic records taken from the FEMA P695 database, i.e. all 44 "Far-Field" (22 NS, 22 WE) earthquake signals. The modal estimates are statistically compared to their target values, proving the accuracy of the developed algorithm in providing prompt and accurate estimates of all current strong ground motion modal parameters. At this stage, such analysis tool may be employed for convenient application in the realm of Earthquake Engineering, towards potential Structural Health Monitoring and damage detection purposes.

The contribution of molecular epidemiology to the identification of human carcinogens: current status and future perspectives.

PubMed

Boffetta, P; Islami, F

2013-04-01

The use of biological-based markers of exposure, intermediate effect, outcome, and susceptibility has become standard practice in cancer epidemiology, which has contributed to identification of several carcinogenic agents. Nevertheless, with the exception of biological agents, this contribution, in terms of providing sufficiently strong evidence as required by the International Agency for Research on Cancer (IARC) monographs, has been modest. We discuss the overall contribution of molecular epidemiology to identification of carcinogens, with focus on IARC monographs. For many carcinogens, valid biological markers of exposure and mechanisms of actions are not available. Molecular markers are usually assessed in single biological samples, which may not represent the actual exposure or biological events related to carcinogens. The contribution of molecular epidemiology to identification of carcinogens has mainly been limited to the carcinogens acting through a genotoxic mechanism, i.e. when carcinogens induce DNA damage. A number of factors, including certain hormones and overweight/obesity, may show carcinogenic effects through nongenotoxic pathways, for which mechanisms of carcinogenicity are not well identified and their biomarkers are sparse. Longitudinal assessment of biomarkers may provide more informative data in molecular epidemiology studies. For many carcinogens and mechanistic pathways, in particular nongenotoxic carcinogenicity, valid biological markers still need to be identified.

Integration of Earth Remote Sensing into the NOAA/NWS Damage Assessment Toolkit

NASA Astrophysics Data System (ADS)

Molthan, A.; Burks, J. E.; Camp, P.; McGrath, K.; Bell, J. R.

2014-12-01

Following the occurrence of severe weather, NOAA/NWS meteorologists are tasked with performing a storm damage survey to assess the type and severity of the weather event, primarily focused with the confirmation and assessment of tornadoes. This labor-intensive process requires meteorologists to venture into the affected area, acquire damage indicators through photos, eyewitness accounts, and other documentation, then aggregation of data in order to make a final determination of the tornado path length, width, maximum intensity, and other characteristics. Earth remote sensing from operational, polar-orbiting satellites can support the damage assessment process by helping to identify portions of damage tracks that are difficult to access due to road limitations or time constraints by applying change detection techniques. In addition, higher resolution commercial imagery can corroborate ground-based surveys by examining higher-resolution commercial imagery. As part of an ongoing collaboration, NASA and NOAA are working to integrate near real-time Earth remote sensing observations into the NOAA/NWS Damage Assessment Toolkit (DAT), a suite of applications used by meteorologists in the survey process. The DAT includes a handheld application used by meteorologists in the survey process. The team has recently developed a more streamlined approach for delivering data via a web mapping service and menu interface, allowing for caching of imagery before field deployment. Near real-time products have been developed using MODIS and VIIRS imagery and change detection for preliminary track identification, along with conduits for higher-resolution Landsat, ASTER, and commercial imagery as they become available. In addition to tornado damage assessments, the team is also investigating the use of near real-time imagery for identifying hail damage to vegetation, which also results in large swaths of damage, particularly in the central United States during the peak growing season months of June, July, and August. This presentation will present an overview of recent activities, challenges and successes, best practices, and opportunities for future work and collaboration.

Integration of Earth Remote Sensing into the NOAA/NWS Damage Assessment Toolkit

NASA Technical Reports Server (NTRS)

Molthan, Andrew; Burks, Jason; Camp, Parks; McGrath, Kevin; Bell, Jordan

2014-01-01

Following the occurrence of severe weather, NOAA/NWS meteorologists are tasked with performing a storm damage survey to assess the type and severity of the weather event, primarily focused with the confirmation and assessment of tornadoes. This labor-intensive process requires meteorologists to venture into the affected area, acquire damage indicators through photos, eyewitness accounts, and other documentation, then aggregation of data in order to make a final determination of the tornado path length, width, maximum intensity, and other characteristics. Earth remote sensing from operational, polar-orbiting satellites can support the damage assessment process by helping to identify portions of damage tracks that are difficult to access due to road limitations or time constraints by applying change detection techniques. In addition, higher resolution commercial imagery can corroborate ground-based surveys by examining higher-resolution commercial imagery. As part of an ongoing collaboration, NASA and NOAA are working to integrate near real-time Earth remote sensing observations into the NOAA/NWS Damage Assessment Toolkit, a handheld application used by meteorologists in the survey process. The team has recently developed a more streamlined approach for delivering data via a web mapping service and menu interface, allowing for caching of imagery before field deployment. Near real-time products have been developed using MODIS and VIIRS imagery and change detection for preliminary track identification, along with conduits for higher-resolution Landsat, ASTER, and commercial imagery as they become available. In addition to tornado damage assessments, the team is also investigating the use of near real-time imagery for identifying hail damage to vegetation, which also results in large swaths of damage, particularly in the central United States during the peak growing season months of June, July, and August. This presentation will present an overview of recent activities, challenges and successes, best practices, and opportunities for future work and collaboration.

In situ damage monitoring in vibration mechanics: diagnostics and predictive maintenance

NASA Astrophysics Data System (ADS)

Basseville, M.; Benveniste, A.; Gach-Devauchelle, B.; Goursat, M.; Bonnecase, D.; Dorey, P.; Prevosto, M.; Olagnon, M.

1993-09-01

A system identification approach is presented for damage monitoring in vibration mechanics. Identification, detection, and diagnostics are performed using accelerometer measurements from the system at work so that the excitation is not controlled, usually not observed and may involve turbulent phenomena. Targeted applications include power engineering (rotating machines, core and pipes of nuclear power plants), civil engineering (large buildings subject to hurricanes or earthquakes, bridges, dams, offshore structures), aeronautics (wings and other structures subject to strength), automobile, rail transportation etc. The method is illustrated by a laboratory example, and the results of 3 years industrial usage. This paper is a progress report on a 10 year project involving three people almost permanently. We describe here the whole approach but omit the technical details which are available in previous papers.

Mass spectrometry-based cDNA profiling as a potential tool for human body fluid identification.

PubMed

Donfack, Joseph; Wiley, Anissa

2015-05-01

Several mRNA markers have been exhaustively evaluated for the identification of human venous blood, saliva, and semen in forensic genetics. As new candidate human body fluid specific markers are discovered, evaluated, and reported in the scientific literature, there is an increasing trend toward determining the ideal markers for cDNA profiling of body fluids of forensic interest. However, it has not been determined which molecular genetics-based technique(s) should be utilized to assess the performance of these markers. In recent years, only a few confirmatory, mRNA/cDNA-based methods have been evaluated for applications in body fluid identification. The most frequently described methods tested to date include quantitative polymerase chain reaction (qPCR) and capillary electrophoresis (CE). However these methods, in particular qPCR, often favor narrow multiplex PCR due to the availability of a limited number of fluorescent dyes/tags. In an attempt to address this technological constraint, this study explored matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) for human body fluid identification via cDNA profiling of venous blood, saliva, and semen. Using cDNA samples at 20pg input phosphoglycerate kinase 1 (PGK1) amounts, body fluid specific markers for the candidate genes were amplified in their corresponding body fluid (i.e., venous blood, saliva, or semen) and absent in the remaining two (100% specificity). The results of this study provide an initial indication that MALDI-TOF MS is a potential fluorescent dye-free alternative method for body fluid identification in forensic casework. However, the inherent issues of low amounts of mRNA, and the damage caused to mRNA by environmental exposures, extraction processes, and storage conditions are important factors that significantly hinder the implementation of cDNA profiling into forensic casework. Published by Elsevier Ireland Ltd.

Aerodynamic Effects and Modeling of Damage to Transport Aircraft

NASA Technical Reports Server (NTRS)

Shah, Gautam H.

2008-01-01

A wind tunnel investigation was conducted to measure the aerodynamic effects of damage to lifting and stability/control surfaces of a commercial transport aircraft configuration. The modeling of such effects is necessary for the development of flight control systems to recover aircraft from adverse, damage-related loss-of-control events, as well as for the estimation of aerodynamic characteristics from flight data under such conditions. Damage in the form of partial or total loss of area was applied to the wing, horizontal tail, and vertical tail. Aerodynamic stability and control implications of damage to each surface are presented, to aid in the identification of potential boundaries in recoverable stability or control degradation. The aerodynamic modeling issues raised by the wind tunnel results are discussed, particularly the additional modeling requirements necessitated by asymmetries due to damage, and the potential benefits of such expanded modeling.

The role of DNA repair pathways in cisplatin resistant lung cancer.

PubMed

O'Grady, Shane; Finn, Stephen P; Cuffe, Sinead; Richard, Derek J; O'Byrne, Kenneth J; Barr, Martin P

2014-12-01

Platinum chemotherapeutic agents such as cisplatin are currently used in the treatment of various malignancies such as lung cancer. However, their efficacy is significantly hindered by the development of resistance during treatment. While a number of factors have been reported that contribute to the onset of this resistance phenotype, alterations in the DNA repair capacity of damaged cells is now recognised as an important factor in mediating this phenomenon. The mode of action of cisplatin has been linked to its ability to crosslink purine bases on the DNA, thereby interfering with DNA repair mechanisms and inducing DNA damage. Following DNA damage, cells respond by activating a DNA-damage response that either leads to repair of the lesion by the cell thereby promoting resistance to the drug, or cell death via activation of the apoptotic response. Therefore, DNA repair is a vital target to improving cancer therapy and reduce the resistance of tumour cells to DNA damaging agents currently used in the treatment of cancer patients. To date, despite the numerous findings that differential expression of components of the various DNA repair pathways correlate with response to cisplatin, translation of such findings in the clinical setting are still warranted. The identification of alterations in specific proteins and pathways that contribute to these unique DNA repair pathways in cisplatin resistant cancer cells may potentially lead to a renewed interest in the development of rational novel therapies for cisplatin resistant cancers, in particular, lung cancer. Copyright © 2014 Elsevier Ltd. All rights reserved.

Experiment on interface separation detection of concrete-filled steel tubular arch bridge using accelerometer array

NASA Astrophysics Data System (ADS)

Pan, Shengshan; Zhao, Xuefeng; Zhao, Hailiang; Mao, Jian

2015-04-01

Based on the vibration testing principle, and taking the local vibration of steel tube at the interface separation area as the study object, a real-time monitoring and the damage detection method of the interface separation of concrete-filled steel tube by accelerometer array through quantitative transient self-excitation is proposed. The accelerometers are arranged on the steel tube area with or without void respectively, and the signals of accelerometers are collected at the same time and compared under different transient excitation points. The results show that compared with the signal of compact area, the peak value of accelerometer signal at void area increases and attenuation speed slows down obviously, and the spectrum peaks of the void area are much more and disordered and the amplitude increases obviously. whether the input point of transient excitation is on void area or not is irrelevant with qualitative identification results. So the qualitative identification of the interface separation of concrete-filled steel tube based on the signal of acceleration transducer is feasible and valid.

Optimal Electrode Selection for Electrical Resistance Tomography in Carbon Fiber Reinforced Polymer Composites

PubMed Central

Escalona Galvis, Luis Waldo; Diaz-Montiel, Paulina; Venkataraman, Satchi

2017-01-01

Electrical Resistance Tomography (ERT) offers a non-destructive evaluation (NDE) technique that takes advantage of the inherent electrical properties in carbon fiber reinforced polymer (CFRP) composites for internal damage characterization. This paper investigates a method of optimum selection of sensing configurations for delamination detection in thick cross-ply laminates using ERT. Reduction in the number of sensing locations and measurements is necessary to minimize hardware and computational effort. The present work explores the use of an effective independence (EI) measure originally proposed for sensor location optimization in experimental vibration modal analysis. The EI measure is used for selecting the minimum set of resistance measurements among all possible combinations resulting from selecting sensing electrode pairs. Singular Value Decomposition (SVD) is applied to obtain a spectral representation of the resistance measurements in the laminate for subsequent EI based reduction to take place. The electrical potential field in a CFRP laminate is calculated using finite element analysis (FEA) applied on models for two different laminate layouts considering a set of specified delamination sizes and locations with two different sensing arrangements. The effectiveness of the EI measure in eliminating redundant electrode pairs is demonstrated by performing inverse identification of damage using the full set and the reduced set of resistance measurements. This investigation shows that the EI measure is effective for optimally selecting the electrode pairs needed for resistance measurements in ERT based damage detection. PMID:28772485

Risk-Based Fire Safety Experiment Definition for Manned Spacecraft

NASA Technical Reports Server (NTRS)

Apostolakis, G. E.; Ho, V. S.; Marcus, E.; Perry, A. T.; Thompson, S. L.

1989-01-01

Risk methodology is used to define experiments to be conducted in space which will help to construct and test the models required for accident sequence identification. The development of accident scenarios is based on the realization that whether damage occurs depends on the time competition of two processes: the ignition and creation of an adverse environment, and the detection and suppression activities. If the fire grows and causes damage faster than it is detected and suppressed, then an accident occurred. The proposed integrated experiments will provide information on individual models that apply to each of the above processes, as well as previously unidentified interactions and processes, if any. Initially, models that are used in terrestrial fire risk assessments are considered. These include heat and smoke release models, detection and suppression models, as well as damage models. In cases where the absence of gravity substantially invalidates a model, alternate models will be developed. Models that depend on buoyancy effects, such as the multizone compartment fire models, are included in these cases. The experiments will be performed in a variety of geometries simulating habitable areas, racks, and other spaces. These simulations will necessitate theoretical studies of scaling effects. Sensitivity studies will also be carried out including the effects of varying oxygen concentrations, pressures, fuel orientation and geometry, and air flow rates. The experimental apparatus described herein includes three major modules: the combustion, the fluids, and the command and power modules.

Optimal Electrode Selection for Electrical Resistance Tomography in Carbon Fiber Reinforced Polymer Composites.

PubMed

Escalona Galvis, Luis Waldo; Diaz-Montiel, Paulina; Venkataraman, Satchi

2017-02-04

Electrical Resistance Tomography (ERT) offers a non-destructive evaluation (NDE) technique that takes advantage of the inherent electrical properties in carbon fiber reinforced polymer (CFRP) composites for internal damage characterization. This paper investigates a method of optimum selection of sensing configurations for delamination detection in thick cross-ply laminates using ERT. Reduction in the number of sensing locations and measurements is necessary to minimize hardware and computational effort. The present work explores the use of an effective independence (EI) measure originally proposed for sensor location optimization in experimental vibration modal analysis. The EI measure is used for selecting the minimum set of resistance measurements among all possible combinations resulting from selecting sensing electrode pairs. Singular Value Decomposition (SVD) is applied to obtain a spectral representation of the resistance measurements in the laminate for subsequent EI based reduction to take place. The electrical potential field in a CFRP laminate is calculated using finite element analysis (FEA) applied on models for two different laminate layouts considering a set of specified delamination sizes and locations with two different sensing arrangements. The effectiveness of the EI measure in eliminating redundant electrode pairs is demonstrated by performing inverse identification of damage using the full set and the reduced set of resistance measurements. This investigation shows that the EI measure is effective for optimally selecting the electrode pairs needed for resistance measurements in ERT based damage detection.

Serial Clustering of North Atlantic Cyclones and Wind Storms: A New Identification Base and Sensitivity to Intensity and Intra-Seasonal Variability

NASA Astrophysics Data System (ADS)

Leckebusch, G. C.; Kirchner-Bossi, N. O.; Befort, D. J.; Ulbrich, U.

2015-12-01

Time-clustered mid-latitude winter storms are responsible for a large portion of the overall windstorm-related damage in Europe. Thus, its study entails a high meteorological interest, while its outcome can result in a crucial utility for the (re)insurance industry. In addition to existing cyclone-based studies, here we use an event identification approach based on surface near wind speeds only, to investigate windstorm clustering and compare it to cyclone clustering. Specifically, cyclone and windstorm tracks are identified for winter 1979-2013 (Oct-Mar), to perform two sensitivity analyses on event-clustering in the North Atlantic using ERA-Interim Reanalysis. First, the link between clustering and cyclone intensity is analysed and compared to windstorms. Secondly, the sensitivity of clustering on intra-seasonal time scales is investigated, for both cyclones and windstorms. The wind-based approach reveals additional regions of clustering over Western Europe, which could be related to extreme damages, showing the added value of investigating wind field derived tracks in addition to that of cyclone tracks. Previous studies indicate a higher degree of clustering for stronger cyclones. However, our results show that this assumption is not always met. Although a positive relationship is confirmed for the clustering centre located over Iceland, clustering off the coast of the Iberian Peninsula behaves opposite. Even though this region shows the highest clustering, most of its signal is due to cyclones with intensities below the 70th percentile of the Laplacian of MSLP. Results on the sensitivity of clustering to the time of the winter season (Oct-Mar) show a temporal evolution of the clustering patterns, for both windstorms and cyclones. Compared to all cyclones, clustering of windstorms and strongest cyclones culminate around February, while all cyclone clustering peak in December to January.

[Physical and chemical emergencies in dermatology].

PubMed

Malisiewicz, B; Meissner, M; Kaufmann, R; Valesky, E

2018-05-01

Physical and chemical emergencies are often caused by household or work accidents. Regardless of the medical field and outside specialized clinics, the physician may be confronted with the situation for first or secondary care. The identification of the causing agent and a rapid assessment of the extent and severity of the tissue damage are essential to initiate early transfer to a specialized burn clinic. Grade 2b tissue damage is usually surgically treated. Smaller and superficial injuries can often be conservatively treated. Even supposedly safe and over-the-counter medicines can also lead to serious tissue damage.

Computational inverse methods of heat source in fatigue damage problems

NASA Astrophysics Data System (ADS)

Chen, Aizhou; Li, Yuan; Yan, Bo

2018-04-01

Fatigue dissipation energy is the research focus in field of fatigue damage at present. It is a new idea to solve the problem of calculating fatigue dissipation energy by introducing inverse method of heat source into parameter identification of fatigue dissipation energy model. This paper introduces the research advances on computational inverse method of heat source and regularization technique to solve inverse problem, as well as the existing heat source solution method in fatigue process, prospects inverse method of heat source applying in fatigue damage field, lays the foundation for further improving the effectiveness of fatigue dissipation energy rapid prediction.

Microfluidics-Based Lab-on-Chip Systems in DNA-Based Biosensing: An Overview

PubMed Central

Dutse, Sabo Wada; Yusof, Nor Azah

2011-01-01

Microfluidics-based lab-on-chip (LOC) systems are an active research area that is revolutionising high-throughput sequencing for the fast, sensitive and accurate detection of a variety of pathogens. LOCs also serve as portable diagnostic tools. The devices provide optimum control of nanolitre volumes of fluids and integrate various bioassay operations that allow the devices to rapidly sense pathogenic threat agents for environmental monitoring. LOC systems, such as microfluidic biochips, offer advantages compared to conventional identification procedures that are tedious, expensive and time consuming. This paper aims to provide a broad overview of the need for devices that are easy to operate, sensitive, fast, portable and sufficiently reliable to be used as complementary tools for the control of pathogenic agents that damage the environment. PMID:22163925

Using Satellite Remote Sensing to assist the National Weather Service (NWS) in Storm Damage Surveys

NASA Astrophysics Data System (ADS)

Schultz, L. A.; Molthan, A.; McGrath, K.; Bell, J. R.; Cole, T.; Burks, J.

2016-12-01

In recent years, the NWS has developed a GIS-based application, called the Damage Assessment Toolkit (DAT), to conduct storm surveys after severe weather events. At present, the toolkit is primarily used for tornado damage surveys and facilitates the identification of damage indicators in accordance with the Enhanced Fujita (EF) intensity scale by allowing surveyors to compare time- and geo-tagged photos against the EF scale guidelines. Mobile and web-based applications provide easy access to the DAT for NWS personnel while performing their duties in the field or office. Multispectral satellite remote sensing imagery has demonstrated benefits for the detection and mapping of damage tracks caused by tornadoes, especially for long-track events and/or areas not easily accessed by NWS personnel. For example, imagery from MODIS, Landsat 7, Landsat 8, ASTER, Sentinel 2, and commercial satellites, collected and distributed in collaboration with the USGS Hazards Data Distribution System, have been useful for refining track location and extent through a "bird's eye" view of the damaged areas. The NASA Short-term Prediction Research and Transition (SPoRT) Center has been working with the NWS and USGS to provide imagery and derived products from polar-orbiting satellite platforms to assist in the detection and refinement of tornado tracks as part of a NASA Applied Science: Disasters project. Working closely with select Weather Forecast Offices (WFOs) and Regional Operations Centers (ROCs) in both the NWS Central and Southern regions, high- and medium-resolution (0.5 - 30 m and 250 m - 1 km resolutions, respectively) imagery and derived products have been provided to the DAT interface for evaluation of operational utility by the NWS for their use in both the field and in the office during post event analysis. Highlighted in this presentation will be case studies where the remotely sensed imagery assisted in the adjustment of a tornado track. Examples will be shown highlighting both the strengths and weaknesses of the optical imagery as well as areas where false color composites may offer additional guidance to the forecaster in the damage survey process.

Explicit memory and implicit memory in occipital lobe stroke patients.

PubMed

Gong, Liang; Wang, JiHua; Feng, Lei; Wang, MeiHong; Li, Xiu; Hu, JiaYun; Wang, Kai

2015-03-01

Occipital stroke patients mainly showed cortical blindness and unilateral vision loss; memory is generally reserved. Recent reports from neuroimaging show the occipital lobe may be involved in the processing of implicit memory (IM), especially the perception type of IM processing. In this study, we explored the explicit memory (EM) and IM damage in occipital lobe stroke patients. A total of 25 occipital strokes and 29 years of age, educational level equivalent healthy controls (HCs), evaluated by using immediate recall, delayed recall, recognition for EM tasks, picture identification, and category exemplar generation for IM tasks. There was no significant difference between occipital stroke patients and HCs in EM tasks and category exemplar generation task. In the picture identification task, occipital lobe stroke group score was poorer than HC group, the results were statistically significant, but in the pictures identify rate, occipital stroke patients and normal control group had no significant difference. The occipital stroke patients may have IM damage, primarily damage the perception type of IM priming effects, which was unrelated with their cortical blindness. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Projected Uses of Cellular Models and Fluorescence Microscopy for Identification of Antivesicants

DTIC Science & Technology

1993-05-13

AD-P008 761 PROJECTED USES OF CELLULAR MODELS AND FLUORESCENCE MICROSCOPY FOR IDENTIFICATION OF ANTIVESICANTS Millard M. Mershon, Stacey M...epidermal keratinocytes (NHEK), fluorescent dye marker probes and spectrofluorometry led to a preliminary feasibility study’ This showed that the...acetoxymethyl ester that is taken into cells and cleaved by intracellular esterases’. It remains as a fluorescent marker until it leaks out through damaged

Audit of pressure area care and documentation.

PubMed

Cockbill-Black, S; Bond, J; Bersée-Mills, A; Warren, K; Hammerton, S; Found, D; Daley, L

1999-12-01

Intensive care patients are at particular risk of pressure damage. Documentation does not always fully reflect practice. Pressure sore identification remains a subjective issue. Nurses do not always complete patient documentation.

Documentation Protocols to Generate Risk Indicators Regarding Degradation Processes for Cultural Heritage Risk Evaluation

NASA Astrophysics Data System (ADS)

Kioussi, A.; Karoglou, M.; Bakolas, A.; Labropoulos, K.; Moropoulou, A.

2013-07-01

Sustainable maintenance and preservation of cultural heritage assets depends highly on its resilience to external or internal alterations and to various hazards. Risk assessment of a heritage asset's can be defined as the identification of all potential hazards affecting it and the evaluation of the asset's vulnerability (building materials and building structure conservation state).Potential hazards for cultural heritage are complex and varying. The risk of decay and damage associated with monuments is not limited to certain long term natural processes, sudden events and human impact (macroscale of the heritage asset) but is also a function of the degradation processes within materials and structural elements due to physical and chemical procedures. Obviously, these factors cover different scales of the problem. The deteriorating processes in materials may be triggered by external influences or caused because of internal chemical and/or physical variations of materials properties and characteristics. Therefore risk evaluation should be dealt in the direction of revealing the specific active decay and damage mechanism both in mesoscale [type of decay and damage] and microscale [decay phenomenon mechanism] level. A prerequisite for risk indicators identification and development is the existence of an organised source of comparable and interoperable data about heritage assets under observation. This unified source of information offers a knowledge based background of the asset's vulnerability through the diagnosis of building materials' and building structure's conservation state, through the identification of all potential hazards affecting these and through mapping of its possible alterations during its entire life-time. In this framework the identification and analysis of risks regarding degradation processes for the development of qualitative and quantitative indicators can be supported by documentation protocols. The data investigated by such protocols help identify the parameters needed for the assessment of the preservation state of a monument and its monitoring through its entire lifetime. The main tool for detecting these indicators is a diagnostic methodology based on appropriate standards that reveals the actual degradation processes responsible of the asset's vulnerability. It is very important that the integration between the material's diagnosis and the overall documentation is taken into consideration in order to identify the required levels of protection and preventive conservation for heritage assets depending on the most frequent local risks. The ranging of risks is therefore necessary according to their importance in each area. Documentation protocols provide with a specific diagnostic tool for materials characterization, decay diagnosis, evaluation process of former conservation materials and interventions, standard procedures for monitoring and control as well as data documentation based on specific guidelines and standards. Implementation and analysis of a "standardised" diagnostic study will reveal the main risks due to degradation processes affecting the heritage asset to be subsequently recorded in order to result into risk indicators. The development of risk indicators regarding degradation processes is the basic step towards uptaking efficient management, preventive conservation and strategic planning for heritage assets against various threats. These risk indicators could be further elaborated according to the activities of inspection, diagnosis and intervention works, offering scientific support to the decision making process for cultural heritage preventive conservation and overall protection.

Next generation testing strategy for assessment of genomic damage: A conceptual framework and considerations.

PubMed

Dearfield, Kerry L; Gollapudi, B Bhaskar; Bemis, Jeffrey C; Benz, R Daniel; Douglas, George R; Elespuru, Rosalie K; Johnson, George E; Kirkland, David J; LeBaron, Matthew J; Li, Albert P; Marchetti, Francesco; Pottenger, Lynn H; Rorije, Emiel; Tanir, Jennifer Y; Thybaud, Veronique; van Benthem, Jan; Yauk, Carole L; Zeiger, Errol; Luijten, Mirjam

2017-06-01

For several decades, regulatory testing schemes for genetic damage have been standardized where the tests being utilized examined mutations and structural and numerical chromosomal damage. This has served the genetic toxicity community well when most of the substances being tested were amenable to such assays. The outcome from this testing is usually a dichotomous (yes/no) evaluation of test results, and in many instances, the information is only used to determine whether a substance has carcinogenic potential or not. Over the same time period, mechanisms and modes of action (MOAs) that elucidate a wider range of genomic damage involved in many adverse health outcomes have been recognized. In addition, a paradigm shift in applied genetic toxicology is moving the field toward a more quantitative dose-response analysis and point-of-departure (PoD) determination with a focus on risks to exposed humans. This is directing emphasis on genomic damage that is likely to induce changes associated with a variety of adverse health outcomes. This paradigm shift is moving the testing emphasis for genetic damage from a hazard identification only evaluation to a more comprehensive risk assessment approach that provides more insightful information for decision makers regarding the potential risk of genetic damage to exposed humans. To enable this broader context for examining genetic damage, a next generation testing strategy needs to take into account a broader, more flexible approach to testing, and ultimately modeling, of genomic damage as it relates to human exposure. This is consistent with the larger risk assessment context being used in regulatory decision making. As presented here, this flexible approach for examining genomic damage focuses on testing for relevant genomic effects that can be, as best as possible, associated with an adverse health effect. The most desired linkage for risk to humans would be changes in loci associated with human diseases, whether in somatic or germ cells. The outline of a flexible approach and associated considerations are presented in a series of nine steps, some of which can occur in parallel, which was developed through a collaborative effort by leading genetic toxicologists from academia, government, and industry through the International Life Sciences Institute (ILSI) Health and Environmental Sciences Institute (HESI) Genetic Toxicology Technical Committee (GTTC). The ultimate goal is to provide quantitative data to model the potential risk levels of substances, which induce genomic damage contributing to human adverse health outcomes. Any good risk assessment begins with asking the appropriate risk management questions in a planning and scoping effort. This step sets up the problem to be addressed (e.g., broadly, does genomic damage need to be addressed, and if so, how to proceed). The next two steps assemble what is known about the problem by building a knowledge base about the substance of concern and developing a rational biological argument for why testing for genomic damage is needed or not. By focusing on the risk management problem and potential genomic damage of concern, the next step of assay(s) selection takes place. The work-up of the problem during the earlier steps provides the insight to which assays would most likely produce the most meaningful data. This discussion does not detail the wide range of genomic damage tests available, but points to types of testing systems that can be very useful. Once the assays are performed and analyzed, the relevant data sets are selected for modeling potential risk. From this point on, the data are evaluated and modeled as they are for any other toxicology endpoint. Any observed genomic damage/effects (or genetic event(s)) can be modeled via a dose-response analysis and determination of an estimated PoD. When a quantitative risk analysis is needed for decision making, a parallel exposure assessment effort is performed (exposure assessment is not detailed here as this is not the focus of this discussion; guidelines for this assessment exist elsewhere). Then the PoD for genomic damage is used with the exposure information to develop risk estimations (e.g., using reference dose (RfD), margin of exposure (MOE) approaches) in a risk characterization and presented to risk managers for informing decision making. This approach is applicable now for incorporating genomic damage results into the decision-making process for assessing potential adverse outcomes in chemically exposed humans and is consistent with the ILSI HESI Risk Assessment in the 21st Century (RISK21) roadmap. This applies to any substance to which humans are exposed, including pharmaceuticals, agricultural products, food additives, and other chemicals. It is time for regulatory bodies to incorporate the broader knowledge and insights provided by genomic damage results into the assessments of risk to more fully understand the potential of adverse outcomes in chemically exposed humans, thus improving the assessment of risk due to genomic damage. The historical use of genomic damage data as a yes/no gateway for possible cancer risk has been too narrowly focused in risk assessment. The recent advances in assaying for and understanding genomic damage, including eventually epigenetic alterations, obviously add a greater wealth of information for determining potential risk to humans. Regulatory bodies need to embrace this paradigm shift from hazard identification to quantitative analysis and to incorporate the wider range of genomic damage in their assessments of risk to humans. The quantitative analyses and methodologies discussed here can be readily applied to genomic damage testing results now. Indeed, with the passage of the recent update to the Toxic Substances Control Act (TSCA) in the US, the new generation testing strategy for genomic damage described here provides a regulatory agency (here the US Environmental Protection Agency (EPA), but suitable for others) a golden opportunity to reexamine the way it addresses risk-based genomic damage testing (including hazard identification and exposure). Environ. Mol. Mutagen. 58:264-283, 2017. © 2016 The Authors. Environmental and Molecular Mutagenesis Published by Wiley Periodicals, Inc. © 2016 The Authors. Environmental and Molecular Mutagenesis Published by Wiley Periodicals, Inc.

Lane Marking Detection and Reconstruction with Line-Scan Imaging Data.

PubMed

Li, Lin; Luo, Wenting; Wang, Kelvin C P

2018-05-20

A bstract: Lane marking detection and localization are crucial for autonomous driving and lane-based pavement surveys. Numerous studies have been done to detect and locate lane markings with the purpose of advanced driver assistance systems, in which image data are usually captured by vision-based cameras. However, a limited number of studies have been done to identify lane markings using high-resolution laser images for road condition evaluation. In this study, the laser images are acquired with a digital highway data vehicle (DHDV). Subsequently, a novel methodology is presented for the automated lane marking identification and reconstruction, and is implemented in four phases: (1) binarization of the laser images with a new threshold method (multi-box segmentation based threshold method); (2) determination of candidate lane markings with closing operations and a marching square algorithm; (3) identification of true lane marking by eliminating false positives (FPs) using a linear support vector machine method; and (4) reconstruction of the damaged and dash lane marking segments to form a continuous lane marking based on the geometry features such as adjacent lane marking location and lane width. Finally, a case study is given to validate effects of the novel methodology. The findings indicate the new strategy is robust in image binarization and lane marking localization. This study would be beneficial in road lane-based pavement condition evaluation such as lane-based rutting measurement and crack classification.

Review of weapon noise measurement and damage risk criteria: considerations for auditory protection and performance.

PubMed

Nakashima, Ann; Farinaccio, Rocco

2015-04-01

Noise-induced hearing loss resulting from weapon noise exposure has been studied for decades. A summary of recent work in weapon noise signal analysis, current knowledge of hearing damage risk criteria, and auditory performance in impulse noise is presented. Most of the currently used damage risk criteria are based on data that cannot be replicated or verified. There is a need to address the effects of combined noise exposures, from similar or different weapons and continuous background noise, in future noise exposure regulations. Advancements in hearing protection technology have expanded the options available to soldiers. Individual selection of hearing protection devices that are best suited to the type of exposure, the auditory task requirements, and hearing status of the user could help to facilitate their use. However, hearing protection devices affect auditory performance, which in turn affects situational awareness in the field. This includes communication capability and the localization and identification of threats. Laboratory training using high-fidelity weapon noise recordings has the potential to improve the auditory performance of soldiers in the field, providing a low-cost tool to enhance readiness for combat. Reprint & Copyright © 2015 Association of Military Surgeons of the U.S.

Foreign Object Damage Identification in Turbine Engines

NASA Technical Reports Server (NTRS)

Strack, William; Zhang, Desheng; Turso, James; Pavlik, William; Lopez, Isaac

2005-01-01

This report summarizes the collective work of a five-person team from different organizations examining the problem of detecting foreign object damage (FOD) events in turbofan engines from gas path thermodynamic and bearing accelerometer sensors, and determining the severity of damage to each component (diagnosis). Several detection and diagnostic approaches were investigated and a software tool (FODID) was developed to assist researchers detect/diagnose FOD events. These approaches include (1) fan efficiency deviation computed from upstream and downstream temperature/ pressure measurements, (2) gas path weighted least squares estimation of component health parameter deficiencies, (3) Kalman filter estimation of component health parameters, and (4) use of structural vibration signal processing to detect both large and small FOD events. The last three of these approaches require a significant amount of computation in conjunction with a physics-based analytic model of the underlying phenomenon the NPSS thermodynamic cycle code for approaches 1 to 3 and the DyRoBeS reduced-order rotor dynamics code for approach 4. A potential application of the FODID software tool, in addition to its detection/diagnosis role, is using its sensitivity results to help identify the best types of sensors and their optimum locations within the gas path, and similarly for bearing accelerometers.

The Focinator v2-0 - Graphical Interface, Four Channels, Colocalization Analysis and Cell Phase Identification.

PubMed

Oeck, Sebastian; Malewicz, Nathalie M; Hurst, Sebastian; Al-Refae, Klaudia; Krysztofiak, Adam; Jendrossek, Verena

2017-07-01

The quantitative analysis of foci plays an important role in various cell biological methods. In the fields of radiation biology and experimental oncology, the effect of ionizing radiation, chemotherapy or molecularly targeted drugs on DNA damage induction and repair is frequently performed by the analysis of protein clusters or phosphorylated proteins recruited to so called repair foci at DNA damage sites, involving for example γ-H2A.X, 53BP1 or RAD51. We recently developed "The Focinator" as a reliable and fast tool for automated quantitative and qualitative analysis of nuclei and DNA damage foci. The refined software is now even more user-friendly due to a graphical interface and further features. Thus, we included an R-script-based mode for automated image opening, file naming, progress monitoring and an error report. Consequently, the evaluation no longer required the attendance of the operator after initial parameter definition. Moreover, the Focinator v2-0 is now able to perform multi-channel analysis of four channels and evaluation of protein-protein colocalization by comparison of up to three foci channels. This enables for example the quantification of foci in cells of a specific cell cycle phase.

Experimental and analytical study of water pipe's rupture for damage identification purposes

NASA Astrophysics Data System (ADS)

Papakonstantinou, Konstantinos G.; Shinozuka, Masanobu; Beikae, Mohsen

2011-04-01

A malfunction, local damage or sudden pipe break of a pipeline system can trigger significant flow variations. As shown in the paper, pressure variations and pipe vibrations are two strongly correlated parameters. A sudden change in the flow velocity and pressure of a pipeline system can induce pipe vibrations. Thus, based on acceleration data, a rapid detection and localization of a possible damage may be carried out by inexpensive, nonintrusive monitoring techniques. To illustrate this approach, an experiment on a single pipe was conducted in the laboratory. Pressure gauges and accelerometers were installed and their correlation was checked during an artificially created transient flow. The experimental findings validated the correlation between the parameters. The interaction between pressure variations and pipe vibrations was also theoretically justified. The developed analytical model explains the connection among flow pressure, velocity, pressure wave propagation and pipe vibration. The proposed method provides a rapid, efficient and practical way to identify and locate sudden failures of a pipeline system and sets firm foundations for the development and implementation of an advanced, new generation Supervisory Control and Data Acquisition (SCADA) system for continuous health monitoring of pipe networks.

Recognition of DNA abasic site nanocavity by fluorophore-switched probe: Suitable for all sequence environments

NASA Astrophysics Data System (ADS)

Wang, Ying; Hu, Yuehua; Wu, Tao; Zhang, Lihua; Liu, Hua; Zhou, Xiaoshun; Shao, Yong

2016-01-01

Removal of a damaged base in DNA produces an abasic site (AP site) nanocavity. If left un-repaired in vivo by the specific enzyme, this nanocavity will result in nucleotide mutation in the following DNA replication. Therefore, selective recognition of AP site nanocavity by small molecules is important for identification of such DNA damage and development of genetic drugs. In this work, we investigate the fluorescence behavior of isoquinoline alkaloids including palmatine (PAL), berberine (BER), epiberberine (EPI), jatrorrhizine (JAT), coptisine (COP), coralyne (COR), worenine (WOR), berberrubine (BEU), sanguinarine (SAN), chelerythrine (CHE), and nitidine (NIT) upon binding with the AP nanocavity. PAL is screened out as the most efficient fluorophore-switched probe to recognize the AP nanocavity over the fully matched DNA. Its fluorescence enhancement occurs for all of the AP nanocavity sequence environments, which has not been achieved by the previously used probes. The bridged π conjugation effect should partially contribute to the AP nanocavity-specific fluorescence, as opposed to the solvent effect. Due to the strong binding with the AP nanocavity, PAL will find wide applications in the DNA damage recognition and sensor development.

DNA damage protection against free radicals of two antioxidant neolignan glucosides from sugarcane molasses.

PubMed

Asikin, Yonathan; Takahashi, Makoto; Mizu, Masami; Takara, Kensaku; Oku, Hirosuke; Wada, Koji

2016-03-15

Sugarcane molasses is a potential by-product of the sugarcane manufacturing industry that is rich in antioxidant materials. The present study aimed to obtain antioxidative compounds from sugarcane molasses and to evaluate their ability to protect DNA from oxidative damage. Two neolignan glucosides were isolated from sugarcane molasses using bioassay and UV spectra monitoring-guided fractionation. The compounds were elucidated as (7R,8S)-dehydrodiconiferyl alcohol-4-O-β-d-glucoside (1) and (7S,8R)-simulanol-9'-O-β-d-glucoside (2). Neolignan glucoside 2 protected against DNA damage caused by free radicals more effectively than did neolignan glucoside 1 (13.62 and 9.08 µmol L(-1) for peroxyl and hydroxyl radicals, respectively, compared to 48.07 and 14.42 µmol L(-1) ). Additionally, neolignan glucoside 2 exhibited superior DNA protection against free radicals compared with various known antioxidative compounds, including p-coumaric acid, ferulic acid, vanillic acid and epigallocatechin gallate. The isolated neolignan glucosides from sugarcane molasses are able to protect DNA from oxidative damage caused by free radicals. This is the first identification of these two compounds in sugarcane molasses. The sugarcane molasses can therefore be used as potential nutraceutical preventative agents, and the findings may foster the utilization of this by-product as a bioresource-based product. © 2015 Society of Chemical Industry. Copyright © 2015 Society of Chemical Industry.

Comparing model-based adaptive LMS filters and a model-free hysteresis loop analysis method for structural health monitoring

NASA Astrophysics Data System (ADS)

Zhou, Cong; Chase, J. Geoffrey; Rodgers, Geoffrey W.; Xu, Chao

2017-02-01

The model-free hysteresis loop analysis (HLA) method for structural health monitoring (SHM) has significant advantages over the traditional model-based SHM methods that require a suitable baseline model to represent the actual system response. This paper provides a unique validation against both an experimental reinforced concrete (RC) building and a calibrated numerical model to delineate the capability of the model-free HLA method and the adaptive least mean squares (LMS) model-based method in detecting, localizing and quantifying damage that may not be visible, observable in overall structural response. Results clearly show the model-free HLA method is capable of adapting to changes in how structures transfer load or demand across structural elements over time and multiple events of different size. However, the adaptive LMS model-based method presented an image of greater spread of lesser damage over time and story when the baseline model is not well defined. Finally, the two algorithms are tested over a simpler hysteretic behaviour typical steel structure to quantify the impact of model mismatch between the baseline model used for identification and the actual response. The overall results highlight the need for model-based methods to have an appropriate model that can capture the observed response, in order to yield accurate results, even in small events where the structure remains linear.

44 CFR 206.435 - Project identification and selection criteria.

Code of Federal Regulations, 2010 CFR

2010-10-01

... potential loss of life, loss of essential services, damage to critical facilities, or economic hardship on..., environmental enhancement, and economic recovery, when appropriate. [55 FR 35537, Aug. 30, 1990, as amended at...

Identification of corrosion and damage mechanisms by using scanning electron microscopy and energy-dispersive X-ray microanalysis: contribution to failure analysis case histories

NASA Astrophysics Data System (ADS)

Pantazopoulos, G.; Vazdirvanidis, A.

2014-03-01

Emphasis is placed on the evaluation of corrosion failures of copper and machineable brass alloys during service. Typical corrosion failures of the presented case histories mainly focussed on stress corrosion cracking and dezincification that acted as the major degradation mechanisms in components used in piping and water supply systems. SEM assessment, coupled with EDS spectroscopy, revealed the main cracking modes together with the root-source(s) that are responsible for the damage initiation and evolution. In addition, fracture surface observations contributed to the identification of the incurred fracture mechanisms and potential environmental issues that stimulated crack initiation and propagation. Very frequently, the detection of chlorides among the corrosion products served as a suggestive evidence of the influence of working environment on passive layer destabilisation and metal dissolution.

DNA Damage and Repair: Relevance to Mechanisms of Neurodegeneration

PubMed Central

Martin, Lee J.

2008-01-01

DNA damage is a form of cell stress and injury that has been implicated in the pathogenesis of many neurologic disorders, including amyotrophic lateral sclerosis, Alzheimer disease, Down syndrome, Parkinson disease, cerebral ischemia, and head trauma. However, most data reveal only associations, and the role for DNA damage in direct mechanisms of neurodegeneration is vague with respect to being a definitive upstream cause of neuron cell death, rather than a consequence of the degeneration. Although neurons seem inclined to develop DNA damage during oxidative stress, most of the existing work on DNA damage and repair mechanisms has been done in the context of cancer biology using cycling non-neuronal cells but not nondividing (i.e. postmitotic) neurons. Nevertheless, the identification of mutations in genes that encode proteins that function in DNA repair and DNA damage response in human hereditary DNA repair deficiency syndromes and ataxic disorders is establishing a mechanistic precedent that clearly links DNA damage and DNA repair abnormalities with progressive neurodegeneration. This review summarizes DNA damage and repair mechanisms and their potential relevance to the evolution of degeneration in postmitotic neurons. PMID:18431258

New approach to analyzing soil-building systems

USGS Publications Warehouse

Safak, E.

1998-01-01

A new method of analyzing seismic response of soil-building systems is introduced. The method is based on the discrete-time formulation of wave propagation in layered media for vertically propagating plane shear waves. Buildings are modeled as an extension of the layered soil media by assuming that each story in the building is another layer. The seismic response is expressed in terms of wave travel times between the layers, and the wave reflection and transmission coefficients at layer interfaces. The calculation of the response is reduced to a pair of simple finite-difference equations for each layer, which are solved recursively starting from the bedrock. Compared with commonly used vibration formulation, the wave propagation formulation provides several advantages, including the ability to incorporate soil layers, simplicity of the calculations, improved accuracy in modeling the mass and damping, and better tools for system identification and damage detection.A new method of analyzing seismic response of soil-building systems is introduced. The method is based on the discrete-time formulation of wave propagation in layered media for vertically propagating plane shear waves. Buildings are modeled as an extension of the layered soil media by assuming that each story in the building is another layer. The seismic response is expressed in terms of wave travel times between the layers, and the wave reflection and transmission coefficients at layer interfaces. The calculation of the response is reduced to a pair of simple finite-difference equations for each layer, which are solved recursively starting from the bedrock. Compared with commonly used vibration formulation, the wave propagation formulation provides several advantages, including the ability to incorporate soil layers, simplicity of the calculations, improved accuracy in modeling the mass and damping, and better tools for system identification and damage detection.

Using In Vitro High-Throughput Screening Data for Predicting Benzo[k]Fluoranthene Human Health Hazards.

PubMed

Burgoon, Lyle D; Druwe, Ingrid L; Painter, Kyle; Yost, Erin E

2017-02-01

Today there are more than 80,000 chemicals in commerce and the environment. The potential human health risks are unknown for the vast majority of these chemicals as they lack human health risk assessments, toxicity reference values, and risk screening values. We aim to use computational toxicology and quantitative high-throughput screening (qHTS) technologies to fill these data gaps, and begin to prioritize these chemicals for additional assessment. In this pilot, we demonstrate how we were able to identify that benzo[k]fluoranthene may induce DNA damage and steatosis using qHTS data and two separate adverse outcome pathways (AOPs). We also demonstrate how bootstrap natural spline-based meta-regression can be used to integrate data across multiple assay replicates to generate a concentration-response curve. We used this analysis to calculate an in vitro point of departure of 0.751 μM and risk-specific in vitro concentrations of 0.29 μM and 0.28 μM for 1:1,000 and 1:10,000 risk, respectively, for DNA damage. Based on the available evidence, and considering that only a single HSD17B4 assay is available, we have low overall confidence in the steatosis hazard identification. This case study suggests that coupling qHTS assays with AOPs and ontologies will facilitate hazard identification. Combining this with quantitative evidence integration methods, such as bootstrap meta-regression, may allow risk assessors to identify points of departure and risk-specific internal/in vitro concentrations. These results are sufficient to prioritize the chemicals; however, in the longer term we will need to estimate external doses for risk screening purposes, such as through margin of exposure methods. © 2016 Society for Risk Analysis.

Pathogenomics: an updated European Research Agenda.

PubMed

Demuth, Andreas; Aharonowitz, Yair; Bachmann, Till T; Blum-Oehler, Gabriele; Buchrieser, Carmen; Covacci, Antonello; Dobrindt, Ulrich; Emödy, Levente; van der Ende, Arie; Ewbank, Jonathan; Fernández, Luis Angel; Frosch, Matthias; García-Del Portillo, Francisco; Gilmore, Michael S; Glaser, Philippe; Goebel, Werner; Hasnain, Seyed E; Heesemann, Jürgen; Islam, Khalid; Korhonen, Timo; Maiden, Martin; Meyer, Thomas F; Montecucco, Cesare; Oswald, Eric; Parkhill, Julian; Pucciarelli, M Graciela; Ron, Eliora; Svanborg, Catharina; Uhlin, Bernt Eric; Wai, Sun Nyunt; Wehland, Jürgen; Hacker, Jörg

2008-05-01

The emerging genomic technologies and bioinformatics provide novel opportunities for studying life-threatening human pathogens and to develop new applications for the improvement of human and animal health and the prevention, treatment, and diagnosis of infections. Based on the ecology and population biology of pathogens and related organisms and their connection to epidemiology, more accurate typing technologies and approaches will lead to better means of disease control. The analysis of the genome plasticity and gene pools of pathogenic bacteria including antigenic diversity and antigenic variation results in more effective vaccines and vaccine implementation programs. The study of newly identified and uncultivated microorganisms enables the identification of new threats. The scrutiny of the metabolism of the pathogen in the host allows the identification of new targets for anti-infectives and therapeutic approaches. The development of modulators of host responses and mediators of host damage will be facilitated by the research on interactions of microbes and hosts, including mechanisms of host damage, acute and chronic relationships as well as commensalisms. The study of multiple pathogenic and non-pathogenic microbes interacting in the host will improve the management of multiple infections and will allow probiotic and prebiotic interventions. Needless to iterate, the application of the results of improved prevention and treatment of infections into clinical tests will have a positive impact on the management of human and animal disease. The Pathogenomics Research Agenda draws on discussions with experts of the Network of Excellence "EuroPathoGenomics" at the management board meeting of the project held during 18-21 April 2007, in the Villa Vigoni, Menaggio, Italy. Based on a proposed European Research Agenda in the field of pathogenomics by the ERA-NET PathoGenoMics the meeting's participants updated the established list of topics as the research agenda for the future.

Seismic response and damage detection analyses of an instrumented steel moment-framed building

USGS Publications Warehouse

Rodgers, J.E.; Celebi, M.

2006-01-01

The seismic performance of steel moment-framed buildings has been of particular interest since brittle fractures were discovered at the beam-column connections in a number of buildings following the M 6.7 Northridge earthquake of January 17, 1994. A case study of the seismic behavior of an extensively instrumented 13-story steel moment frame building located in the greater Los Angeles area of California is described herein. Response studies using frequency domain, joint time-frequency, system identification, and simple damage detection analyses are performed using an extensive strong motion dataset dating from 1971 to the present, supported by engineering drawings and results of postearthquake inspections. These studies show that the building's response is more complex than would be expected from its highly symmetrical geometry. The response is characterized by low damping in the fundamental mode, larger accelerations in the middle and lower stories than at the roof and base, extended periods of vibration after the cessation of strong input shaking, beating in the response, elliptical particle motion, and significant torsion during strong shaking at the top of the concrete piers which extend from the basement to the second floor. The analyses conducted indicate that the response of the structure was elastic in all recorded earthquakes to date, including Northridge. Also, several simple damage detection methods employed did not indicate any structural damage or connection fractures. The combination of a large, real structure and low instrumentation density precluded the application of many recently proposed advanced damage detection methods in this case study. Overall, however, the findings of this study are consistent with the limited code-compliant postearthquake intrusive inspections conducted after the Northridge earthquake, which found no connection fractures or other structural damage. ?? ASCE.

Security seal. [Patent application

DOEpatents

Gobeli, G.W.

1981-11-17

Security for a package or verifying seal in plastic material is provided by a print seal with unique thermally produced imprints in the plastic. If tampering is attempted, the material is irreparably damaged and thus detectable. The pattern of the imprints, similar to fingerprints are recorded as a positive identification for the seal, and corresponding recordings made to allow comparison. The integrity of the seal is proved by the comparison of imprint identification records made by laser beam projection.

Security seal

DOEpatents

Gobeli, Garth W.

1985-01-01

Security for a package or verifying seal in plastic material is provided by a print seal with unique thermally produced imprints in the plastic. If tampering is attempted, the material is irreparably damaged and thus detectable. The pattern of the imprints, similar to "fingerprints" are recorded as a positive identification for the seal, and corresponding recordings made to allow comparison. The integrity of the seal is proved by the comparison of imprint identification records made by laser beam projection.

High-resolution melt and morphological analyses of mealybugs (Hemiptera: Pseudococcidae) from cacao: tools for the control of Cacao swollen shoot virus spread.

PubMed

Wetten, Andy; Campbell, Colin; Allainguillaume, Joël

2016-03-01

Mealybugs (Hemiptera: Coccoidea: Pseudococcidae) are key vectors of badnaviruses, including Cacao swollen shoot virus (CSSV), the most damaging virus affecting cacao (Theobroma cacao L.). The effectiveness of mealybugs as virus vectors is species dependent, and it is therefore vital that CSSV resistance breeding programmes in cacao incorporate accurate mealybug identification. In this work, the efficacy of a CO1-based DNA barcoding approach to species identification was evaluated by screening a range of mealybugs collected from cacao in seven countries. Morphologically similar adult females were characterised by scanning electron microscopy, and then, following DNA extraction, were screened with CO1 barcoding markers. A high degree of CO1 sequence homology was observed for all 11 individual haplotypes, including those accessions from distinct geographical regions. This has allowed the design of a high-resolution melt (HRM) assay capable of rapid identification of the commonly encountered mealybug pests of cacao. HRM analysis readily differentiated between mealybug pests of cacao that cannot necessarily be identified by conventional morphological analysis. This new approach, therefore, has potential to facilitate breeding for resistance to CSSV and other mealybug-transmitted diseases. © 2015 Society of Chemical Industry.

Identification of natural red and purple dyes on textiles by Fiber-optics Reflectance Spectroscopy

NASA Astrophysics Data System (ADS)

Maynez-Rojas, M. A.; Casanova-González, E.; Ruvalcaba-Sil, J. L.

2017-05-01

Understanding dye chemistry and dye processes is an important issue for studies of cultural heritage collections and science conservation. Fiber Optics Reflectance Spectroscopy (FORS) is a powerful technique, which allows preliminary dye identification, causing no damage or mechanical stress on the artworks subjected to analysis. Some information related to specific light scattering and absorption can be obtained in the UV-visible and infrared range (300-1400 nm) and it is possible to discriminate the kind of support fiber in the near infrared region (1000-2500 nm). The main spectral features of natural dye fibers samples, such as reflection maxima, inflection points and reflection minima, can be used in the differentiation of various red natural dyes. In this work, a set of dyed references were manufactured following Mexican recipes with red dyes (cochineal and brazilwood) in order to determine the characteristic FORS spectral features of fresh and aged dyed fibers for their identification in historical pieces. Based on these results, twenty-nine indigenous textiles belonging to the National Commission for the Development of Indigenous People of Mexico were studied. Cochineal and brazilwood were successfully identified by FORS in several pieces, as well as the mixture of cochineal and indigo for purple color.

Hotspot Identification for Shanghai Expressways Using the Quantitative Risk Assessment Method

PubMed Central

Chen, Can; Li, Tienan; Sun, Jian; Chen, Feng

2016-01-01

Hotspot identification (HSID) is the first and key step of the expressway safety management process. This study presents a new HSID method using the quantitative risk assessment (QRA) technique. Crashes that are likely to happen for a specific site are treated as the risk. The aggregation of the crash occurrence probability for all exposure vehicles is estimated based on the empirical Bayesian method. As for the consequences of crashes, crashes may not only cause direct losses (e.g., occupant injuries and property damages) but also result in indirect losses. The indirect losses are expressed by the extra delays calculated using the deterministic queuing diagram method. The direct losses and indirect losses are uniformly monetized to be considered as the consequences of this risk. The potential costs of crashes, as a criterion to rank high-risk sites, can be explicitly expressed as the sum of the crash probability for all passing vehicles and the corresponding consequences of crashes. A case study on the urban expressways of Shanghai is presented. The results show that the new QRA method for HSID enables the identification of a set of high-risk sites that truly reveal the potential crash costs to society. PMID:28036009

Development of a Near Real-Time Hail Damage Swath Identification Algorithm for Vegetation

NASA Technical Reports Server (NTRS)

Bell, Jordan R.; Molthan, Andrew L.; Schultz, Kori A.; McGrath, Kevin M.; Burks, Jason E.

2015-01-01

Every year in the Midwest and Great Plains, widespread greenness forms in conjunction with the latter part of the spring-summer growing season. This prevalent greenness forms as a result of the high concentration of agricultural areas having their crops reach their maturity before the fall harvest. This time of year also coincides with an enhanced hail frequency for the Great Plains (Cintineo et al. 2012). These severe thunderstorms can bring damaging winds and large hail that can result in damage to the surface vegetation. The spatial extent of the damage can relatively small concentrated area or be a vast swath of damage that is visible from space. These large areas of damage have been well documented over the years. In the late 1960s aerial photography was used to evaluate crop damage caused by hail. As satellite remote sensing technology has evolved, the identification of these hail damage streaks has increased. Satellites have made it possible to view these streaks in additional spectrums. Parker et al. (2005) documented two streaks using the Moderate Resolution Imaging Spectroradiometer (MODIS) that occurred in South Dakota. He noted the potential impact that these streaks had on the surface temperature and associated surface fluxes that are impacted by a change in temperature. Gallo et al. (2012) examined at the correlation between radar signatures and ground observations from storms that produced a hail damage swath in Central Iowa also using MODIS. Finally, Molthan et al. (2013) identified hail damage streaks through MODIS, Landsat-7, and SPOT observations of different resolutions for the development of a potential near-real time applications. The manual analysis of hail damage streaks in satellite imagery is both tedious and time consuming, and may be inconsistent from event to event. This study focuses on development of an objective and automatic algorithm to detect these areas of damage in a more efficient and timely manner. This study utilizes the MODIS sensor aboard the NASA Aqua satellite. Aqua was chosen due to an afternoon orbit over the United States when land surface temperatures are relatively warm and improve the contrast between damaged and undamaged areas. This orbit is also similar to the orbit of the Suomi-National Polar-orbiting Partnership (NPP) satellite. The Suomi NPP satellite hosts the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument, which is the next generation of a MODIS-like sensor in polar orbit.

Genesis Contingency Planning and Mishap Recovery: The Sample Curation View

NASA Technical Reports Server (NTRS)

Stansbery, E. K.; Allton, J. H.; Allen, C. C.; McNamara, K. M.; Calaway, M.; Rodriques, M. C.

2007-01-01

Planning for sample preservation and curation was part of mission design from the beginning. One of the scientific objectives for Genesis included collecting samples of three regimes of the solar wind in addition to collecting bulk solar wind during the mission. Collectors were fabricated in different thicknesses for each regime of the solar wind and attached to separate frames exposed to the solar wind during specific periods of solar activity associated with each regime. The original plan to determine the solar regime sampled for specific collectors was to identify to which frame the collector was attached. However, the collectors were dislodged during the hard landing making identification by frame attachment impossible. Because regimes were also identified by thickness of the collector, the regime sampled is identified by measuring fragment thickness. A variety of collector materials and thin films applied to substrates were selected and qualified for flight. This diversity provided elemental measurement in more than one material, mitigating effects of diffusion rates and/or radiation damage. It also mitigated against different material and substrate strengths resulting in differing effects of the hard landing. For example, silicon crystal substrates broke into smaller fragments than sapphire-based substrates and diamond surfaces were more resilient to flying debris damage than gold. The primary responsibility of the curation team for recovery was process documentation. Contingency planning for the recovery phase expanded this responsibility to include not only equipment to document, but also gather, contain and identify samples from the landing area and the recovered spacecraft. The team developed contingency plans for various scenarios as part of mission planning that included topographic maps to aid in site recovery and identification of different modes of transport and purge capability depending on damage. A clean tent, set-up at Utah Test & Training Range to control the environment for processing the sample return capsule and cleanly installing a nitrogen purge to the canister, was used to control the environment for extracting collector fragments from the damaged canister and to document and package over 10,000 collector fragments.

Chiral Pesticides: Identification, Description and Environmental Implications

EPA Science Inventory

Anthropogenic chemicals, including pesticides, are a major source of contamination and pollution in the environment. Pesticides have many positive uses: increased food production, decreased damage to crops and structures, reduced disease vector populations, and more. Nevertheless...

[Genitalia of three species of Heilipus Germar (Coleoptera: Curculionidae) that damage avocado fruits (Persea americana Mill.) in Mexico and Costa Rica].

PubMed

Castañeda-Vildózola, Alvaro; Valdez-Carrasco, Jorge; Equihua-Martínez, Armando; González-Hernández, Héctor; Romero-Nápoles, Jesús; Solís-Aguilar, Juan F; Ramírez-Alarcón, Samuel

2007-01-01

The male and female genitaliae of three species of the genus Heilipus Germar (H. lauri Boheman, H. pittieri Barber and H. trifasciatus Fabricius) that damage avocado fruits (Persea americana Mill.) in Mexico and Costa Rica are described and illustrated. The aedeagus, spiculum gastrale, styli of 8th sternite are different in each one of the three species studied and can be used for specific identification.

Evaluation of the US Army Fitting Program for the Integrated Helmet Unit of the Integrated Helmet and Display Sighting System

DTIC Science & Technology

1987-07-01

ederick, MD 21701-5012- M WPUM TPOSONINGOFFICE SYMBOL 9 PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGANTICIN(i soppkablo) &L. ADUSS (City umat . and W...distortion, improperly positioned helmet electronics, or damaged HDU receiver assembly, 9 and HDU optical axis misalignment due to a bent combiner or...internal damage to the HDU lens assembly. All components were contractoLr supplied. The scheduling of a fitting session required coordination between

Psychotherapy of the child with true brain damage.

PubMed

Christ, Adolph E

1978-07-01

Psychotherapy of the child with true brain damage presents special problems and requires special approaches. Those who are cognitively primitive--at the sensorimotor or preoperational stage of development--require a crisis approach; those at the concrete or formal operational stage can be treated with a modified insight-oriented approach. Development of a therapeutic alliance, establishment of workable defense mechanisms, identification and clarification of unalterable cognitive defects and issues of termination unique to this special population are discussed.

Multiple damage identification on a wind turbine blade using a structural neural system

NASA Astrophysics Data System (ADS)

Kirikera, Goutham R.; Schulz, Mark J.; Sundaresan, Mannur J.

2007-04-01

A large number of sensors are required to perform real-time structural health monitoring (SHM) to detect acoustic emissions (AE) produced by damage growth on large complicated structures. This requires a large number of high sampling rate data acquisition channels to analyze high frequency signals. To overcome the cost and complexity of having such a large data acquisition system, a structural neural system (SNS) was developed. The SNS reduces the required number of data acquisition channels and predicts the location of damage within a sensor grid. The sensor grid uses interconnected sensor nodes to form continuous sensors. The combination of continuous sensors and the biomimetic parallel processing of the SNS tremendously reduce the complexity of SHM. A wave simulation algorithm (WSA) was developed to understand the flexural wave propagation in composite structures and to utilize the code for developing the SNS. Simulation of AE responses in a plate and comparison with experimental results are shown in the paper. The SNS was recently tested by a team of researchers from University of Cincinnati and North Carolina A&T State University during a quasi-static proof test of a 9 meter long wind turbine blade at the National Renewable Energy Laboratory (NREL) test facility in Golden, Colorado. Twelve piezoelectric sensor nodes were used to form four continuous sensors to monitor the condition of the blade during the test. The four continuous sensors are used as inputs to the SNS. There are only two analog output channels of the SNS, and these signals are digitized and analyzed in a computer to detect damage. In the test of the wind turbine blade, multiple damages were identified and later verified by sectioning of the blade. The results of damage identification using the SNS during this proof test will be shown in this paper. Overall, the SNS is very sensitive and can detect damage on complex structures with ribs, joints, and different materials, and the system relatively inexpensive and simple to implement on large structures.

Structural Health Monitoring of Large Structures

NASA Technical Reports Server (NTRS)

Kim, Hyoung M.; Bartkowicz, Theodore J.; Smith, Suzanne Weaver; Zimmerman, David C.

1994-01-01

This paper describes a damage detection and health monitoring method that was developed for large space structures using on-orbit modal identification. After evaluating several existing model refinement and model reduction/expansion techniques, a new approach was developed to identify the location and extent of structural damage with a limited number of measurements. A general area of structural damage is first identified and, subsequently, a specific damaged structural component is located. This approach takes advantage of two different model refinement methods (optimal-update and design sensitivity) and two different model size matching methods (model reduction and eigenvector expansion). Performance of the proposed damage detection approach was demonstrated with test data from two different laboratory truss structures. This space technology can also be applied to structural inspection of aircraft, offshore platforms, oil tankers, ridges, and buildings. In addition, its applications to model refinement will improve the design of structural systems such as automobiles and electronic packaging.

Health Monitoring System for Composite Structures

NASA Technical Reports Server (NTRS)

Tang, S. S.; Riccardella, P. C.; Andrews, R. J.; Grady, J. E.; Mucciaradi, A. N.

1996-01-01

An automated system was developed to monitor the health status of composites. It uses the vibration characteristics of composites to identify a component's damage condition. The vibration responses are characterized by a set of signal features defined in the time, frequency and spatial domains. The identification of these changes in the vibration characteristics corresponding to different health conditions was performed using pattern recognition principles. This allows efficient data reduction and interpretation of vast amounts of information. Test components were manufactured from isogrid panels to evaluate performance of the monitoring system. The components were damaged by impact to simulate different health conditions. Free vibration response was induced by a tap test on the test components. The monitoring system was trained using these free vibration responses to identify three different health conditions. They are undamaged vs. damaged, damage location and damage zone size. High reliability in identifying the correct component health condition was achieved by the monitoring system.

Chemical methodology as a source of small-molecule checkpoint inhibitors and heat shock protein 70 (Hsp70) modulators.

PubMed

Huryn, Donna M; Brodsky, Jeffrey L; Brummond, Kay M; Chambers, Peter G; Eyer, Benjamin; Ireland, Alex W; Kawasumi, Masaoki; Laporte, Matthew G; Lloyd, Kayla; Manteau, Baptiste; Nghiem, Paul; Quade, Bettina; Seguin, Sandlin P; Wipf, Peter

2011-04-26

Unique chemical methodology enables the synthesis of innovative and diverse scaffolds and chemotypes and allows access to previously unexplored "chemical space." Compound collections based on such new synthetic methods can provide small-molecule probes of proteins and/or pathways whose functions are not fully understood. We describe the identification, characterization, and evolution of two such probes. In one example, a pathway-based screen for DNA damage checkpoint inhibitors identified a compound, MARPIN (ATM and ATR pathway inhibitor) that sensitizes p53-deficient cells to DNA-damaging agents. Modification of the small molecule and generation of an immobilized probe were used to selectively bind putative protein target(s) responsible for the observed activity. The second example describes a focused library approach that relied on tandem multicomponent reaction methodologies to afford a series of modulators of the heat shock protein 70 (Hsp70) molecular chaperone. The synthesis of libraries based on the structure of MAL3-101 generated a collection of chemotypes, each modulating Hsp70 function, but exhibiting divergent pharmacological activities. For example, probes that compromise the replication of a disease-associated polyomavirus were identified. These projects highlight the importance of chemical methodology development as a source of small-molecule probes and as a drug discovery starting point.

Chemical methodology as a source of small-molecule checkpoint inhibitors and heat shock protein 70 (Hsp70) modulators

PubMed Central

Huryn, Donna M.; Brodsky, Jeffrey L.; Brummond, Kay M.; Chambers, Peter G.; Eyer, Benjamin; Ireland, Alex W.; Kawasumi, Masaoki; LaPorte, Matthew G.; Lloyd, Kayla; Manteau, Baptiste; Nghiem, Paul; Quade, Bettina; Seguin, Sandlin P.; Wipf, Peter

2011-01-01

Unique chemical methodology enables the synthesis of innovative and diverse scaffolds and chemotypes and allows access to previously unexplored “chemical space.” Compound collections based on such new synthetic methods can provide small-molecule probes of proteins and/or pathways whose functions are not fully understood. We describe the identification, characterization, and evolution of two such probes. In one example, a pathway-based screen for DNA damage checkpoint inhibitors identified a compound, MARPIN (ATM and ATR pathway inhibitor) that sensitizes p53-deficient cells to DNA-damaging agents. Modification of the small molecule and generation of an immobilized probe were used to selectively bind putative protein target(s) responsible for the observed activity. The second example describes a focused library approach that relied on tandem multicomponent reaction methodologies to afford a series of modulators of the heat shock protein 70 (Hsp70) molecular chaperone. The synthesis of libraries based on the structure of MAL3-101 generated a collection of chemotypes, each modulating Hsp70 function, but exhibiting divergent pharmacological activities. For example, probes that compromise the replication of a disease-associated polyomavirus were identified. These projects highlight the importance of chemical methodology development as a source of small-molecule probes and as a drug discovery starting point. PMID:21502524

Brain tissues atrophy is not always the best structural biomarker of physiological aging: A multimodal cross-sectional study.

PubMed

Cherubini, Andrea; Caligiuri, Maria Eugenia; Péran, Patrice; Sabatini, Umberto; Cosentino, Carlo; Amato, Francesco

2015-01-01

This study presents a voxel-based multiple regression analysis of different magnetic resonance image modalities, including anatomical T1-weighted, T2* relaxometry, and diffusion tensor imaging. Quantitative parameters sensitive to complementary brain tissue alterations, including morphometric atrophy, mineralization, microstructural damage, and anisotropy loss, were compared in a linear physiological aging model in 140 healthy subjects (range 20-74 years). The performance of different predictors and the identification of the best biomarker of age-induced structural variation were compared without a priori anatomical knowledge. The best quantitative predictors in several brain regions were iron deposition and microstructural damage, rather than macroscopic tissue atrophy. Age variations were best resolved with a combination of markers, suggesting that multiple predictors better capture age-induced tissue alterations. These findings highlight the importance of a combined evaluation of multimodal biomarkers for the study of aging and point to a number of novel applications for the method described.

Importance of Multimodal MRI in Characterizing Brain Tissue and Its Potential Application for Individual Age Prediction.

PubMed

Cherubini, Andrea; Caligiuri, Maria Eugenia; Peran, Patrice; Sabatini, Umberto; Cosentino, Carlo; Amato, Francesco

2016-09-01

This study presents a voxel-based multiple regression analysis of different magnetic resonance image modalities, including anatomical T1-weighted, T2(*) relaxometry, and diffusion tensor imaging. Quantitative parameters sensitive to complementary brain tissue alterations, including morphometric atrophy, mineralization, microstructural damage, and anisotropy loss, were compared in a linear physiological aging model in 140 healthy subjects (range 20-74 years). The performance of different predictors and the identification of the best biomarker of age-induced structural variation were compared without a priori anatomical knowledge. The best quantitative predictors in several brain regions were iron deposition and microstructural damage, rather than macroscopic tissue atrophy. Age variations were best resolved with a combination of markers, suggesting that multiple predictors better capture age-induced tissue alterations. The results of the linear model were used to predict apparent age in different regions of individual brain. This approach pointed to a number of novel applications that could potentially help highlighting areas particularly vulnerable to disease.

The deterioration of Circular Mausoleum, Roman Necropolis of Carmona, Spain.

PubMed

Cañaveras, Juan C; Fernandez-Cortes, Angel; Elez, Javier; Cuezva, Soledad; Jurado, Valme; Miller, Ana Zelia; Rogerio-Candelera, Miguel A; Benavente, David; Hernandez-Marine, Mariona; Saiz-Jimenez, Cesareo; Sanchez-Moral, Sergio

2015-06-15

The Circular Mausoleum tomb in the Roman Necropolis of Carmona was carved on a calcarenite sequence in an ancient quarry located in the town of Carmona, Southern Spain. This rock-cut tomb, representative of Roman burial practices, currently suffers from serious deterioration. A detailed survey over several years permitted the identification of the main tomb's pathologies and damaging processes, which include loss of material (scaling, flaking, granular disintegration), surface modifications (efflorescences, crusts and deposits) and extensive biological colonization. The results obtained in this study indicated that anthropogenic changes were largely responsible and enhanced the main alteration mechanisms observed in the Circular Mausoleum. Based on the deterioration diagnosis, effective corrective actions were proposed. This study shows that any conservative intervention in the interior of the tomb should be preceded by accurate in situ measurements and laboratory analyses to ascribe the source of the deterioration damages and thus designing effective treatments. Copyright © 2015 Elsevier B.V. All rights reserved.

An anisotropic thermomechanical damage model for concrete at transient elevated temperatures.

PubMed

Baker, Graham; de Borst, René

2005-11-15

The behaviour of concrete at elevated temperatures is important for an assessment of integrity (strength and durability) of structures exposed to a high-temperature environment, in applications such as fire exposure, smelting plants and nuclear installations. In modelling terms, a coupled thermomechanical analysis represents a generalization of the computational mechanics of fracture and damage. Here, we develop a fully coupled anisotropic thermomechanical damage model for concrete under high stress and transient temperature, with emphasis on the adherence of the model to the laws of thermodynamics. Specific analytical results are given, deduced from thermodynamics, of a novel interpretation on specific heat, evolution of entropy and the identification of the complete anisotropic, thermomechanical damage surface. The model is also shown to be stable in a computational sense, and to satisfy the laws of thermodynamics.

Direct identification of various copper phthalocyanine pigments in automotive paints and paint smears by laser desorption ionization mass spectrometry.

PubMed

Mukai, Tadashi; Nakazumi, Hiroyuki; Kawabata, Shin-ichirou; Kusatani, Masaru; Nakai, Seita; Honda, Sadao

2008-01-01

Direct identification of copper phthalocyanine (CuPc) and chlorinated CuPcs in paints for discrimination between blue automobile paints by means of laser desorption mass spectrometry (LDMS) in the absence of a matrix is reported. The models consisted of eight commercially available CuPc pigments applied to a piece of plain white coating paper. The relationship between the peak intensity at m/z 575 of the CuPc, the number of pulsed laser shots, and laser power was compared to optimize laser abrasion. LDMS analysis of the model paints demonstrated that all characteristic components of the CuPc pigments in the paint films were in good agreement with those in the powder pigments. Further, the chlorinated CuPcs in the paint films could be distinguished. A quantity of 42 blue paint films, representing the paints used for painting Japanese domestic trucks, was examined by LDMS analysis. Results indicate that the paints can be classified into four categories based on the chlorinated CuPc components of the paints. Therefore, LDMS spectra of CuPc pigments would be useful for the identification of paints in forensic investigations. Herein, we report the successful identification of the CuPcs in a paint smear on the frame of a bicycle damaged in a hit-and-run accident, using the LDMS spectra.

From Physical Process to Economic Cost - Integrated Approaches of Landslide Risk Assessment

NASA Astrophysics Data System (ADS)

Klose, M.; Damm, B.

2014-12-01

The nature of landslides is complex in many respects, with landslide hazard and impact being dependent on a variety of factors. This obviously requires an integrated assessment for fundamental understanding of landslide risk. Integrated risk assessment, according to the approach presented in this contribution, implies combining prediction of future landslide occurrence with analysis of landslide impact in the past. A critical step for assessing landslide risk in integrated perspective is to analyze what types of landslide damage affected people and property in which way and how people contributed and responded to these damage types. In integrated risk assessment, the focus is on systematic identification and monetization of landslide damage, and analytical tools that allow deriving economic costs from physical landslide processes are at the heart of this approach. The broad spectrum of landslide types and process mechanisms as well as nonlinearity between landslide magnitude, damage intensity, and direct costs are some main factors explaining recent challenges in risk assessment. The two prevailing approaches for assessing the impact of landslides in economic terms are cost survey (ex-post) and risk analysis (ex-ante). Both approaches are able to complement each other, but yet a combination of them has not been realized so far. It is common practice today to derive landslide risk without considering landslide process-based cause-effect relationships, since integrated concepts or new modeling tools expanding conventional methods are still widely missing. The approach introduced in this contribution is based on a systematic framework that combines cost survey and GIS-based tools for hazard or cost modeling with methods to assess interactions between land use practices and landslides in historical perspective. Fundamental understanding of landslide risk also requires knowledge about the economic and fiscal relevance of landslide losses, wherefore analysis of their impact on public budgets is a further component of this approach. In integrated risk assessment, combination of methods plays an important role, with the objective of collecting and integrating complex data sets on landslide risk.

Algorithm for repairing the damaged images of grain structures obtained from the cellular automata and measurement of grain size

NASA Astrophysics Data System (ADS)

Ramírez-López, A.; Romero-Romo, M. A.; Muñoz-Negron, D.; López-Ramírez, S.; Escarela-Pérez, R.; Duran-Valencia, C.

2012-10-01

Computational models are developed to create grain structures using mathematical algorithms based on the chaos theory such as cellular automaton, geometrical models, fractals, and stochastic methods. Because of the chaotic nature of grain structures, some of the most popular routines are based on the Monte Carlo method, statistical distributions, and random walk methods, which can be easily programmed and included in nested loops. Nevertheless, grain structures are not well defined as the results of computational errors and numerical inconsistencies on mathematical methods. Due to the finite definition of numbers or the numerical restrictions during the simulation of solidification, damaged images appear on the screen. These images must be repaired to obtain a good measurement of grain geometrical properties. Some mathematical algorithms were developed to repair, measure, and characterize grain structures obtained from cellular automata in the present work. An appropriate measurement of grain size and the corrected identification of interfaces and length are very important topics in materials science because they are the representation and validation of mathematical models with real samples. As a result, the developed algorithms are tested and proved to be appropriate and efficient to eliminate the errors and characterize the grain structures.

Evaluation of damage in reinforced concrete bridge beams using acoustic emission technique

NASA Astrophysics Data System (ADS)

Vidya Sagar, R.; Raghu Prasad, B. K.; Sharma, Reema

2012-06-01

Acoustic emission (AE) testing is a well-known method for damage identification of various concrete structures including bridges. This article presents a method to assess damage in reinforced concrete (RC) bridge beams subjected to incremental cyclic loading. The specifications in the standard NDIS-2421 were used to classify the damage in RC bridge beams. Earlier researchers classified the damage occurring in bridge beams by using crack mouth opening displacement (CMOD) and AE released and proposed a standard (NDIS-2421: the Japanese Society for NonDestructive Inspection). In general, multiple cracks take place in RC beams under bending; therefore, utilisation of CMOD for crack detection may not be appropriate. In the present study, the damage in RC beams is classified by using the AE released, deflection, strains in steel and concrete, because the measurement of the strains in steel and concrete is easy and the codes of practice are specified for different limit states (IS-456:2000). The observations made in the present experimental study have some important practical applications in assessing the state of damage of concrete structural members.

A Guide to the Insect Borers, Pruners, and Girdlers of Pecan and Hickory

Treesearch

J.D. Solomon; J.A. Payne

1986-01-01

The importance, identification, biology and indirect control of insects attacking shoots, branches, trunks, and roots of tress are presented. Damage due to and control of the yellow-bellied sapsucker is discussed.

Diagnostic problems associated with cadaveric trauma from animal activity.

PubMed

Byard, Roger W; James, Ross A; Gilbert, John D

2002-09-01

Analysis of a series of deaths between 1986 and 2001 resulting from natural disease, accidents, suicides, and homicide, where postmortem animal activity had traumatized bodies, was undertaken at the Forensic Science Center in Adelaide to demonstrate the range of lesions that may occur and problems in interpretation that result. Tissue damage had been caused by a variety of animals, including fly larvae, ants, birds, dogs, rodents, sea lice, and sharks. Postmortem animal activity had disguised injuries, modified wounds, and created the appearances of inflicted injury. Problems with identification occurred after postmortem facial trauma, and loss of organ parenchyma had interfered with, or precluded, the precise determination of the manner of death in some cases. Specific kinds of tissue and organ damage may occur after death, necessitating careful assessment of lesions in a search for characteristic features of animal activity. The pattern of lesions may enable identification of the particular species of animal involved.

Gene and cell-based therapies for heart disease.

PubMed

Melo, Luis G; Pachori, Alok S; Kong, Deling; Gnecchi, Massimiliano; Wang, Kai; Pratt, Richard E; Dzau, Victor J

2004-04-01

Heart disease remains the prevalent cause of premature death and accounts for a significant proportion of all hospital admissions. Recent developments in understanding the molecular mechanisms of myocardial disease have led to the identification of new therapeutic targets, and the availability of vectors with enhanced myocardial tropism offers the opportunity for the design of gene therapies for both protection and rescue of the myocardium. Genetic therapies have been devised to treat complex diseases such as myocardial ischemia, heart failure, and inherited myopathies in various animal models. Some of these experimental therapies have made a successful transition to clinical trial and are being considered for use in human patients. The recent isolation of endothelial and cardiomyocyte precursor cells from adult bone marrow may permit the design of strategies for repair of the damaged heart. Cell-based therapies may have potential application in neovascularization and regeneration of ischemic and infarcted myocardium, in blood vessel reconstruction, and in bioengineering of artificial organs and prostheses. We expect that advances in the field will lead to the development of safer and more efficient vectors. The advent of genomic screening technology should allow the identification of novel therapeutic targets and facilitate the detection of disease-causing polymorphisms that may lead to the design of individualized gene and cell-based therapies.

Electromechanical Impedance Response of a Cracked Timoshenko Beam

PubMed Central

Zhang, Yuxiang; Xu, Fuhou; Chen, Jiazhao; Wu, Cuiqin; Wen, Dongdong

2011-01-01

Typically, the Electromechanical Impedance (EMI) technique does not use an analytical model for basic damage identification. However, an accurate model is necessary for getting more information about any damage. In this paper, an EMI model is presented for predicting the electromechanical impedance of a cracked beam structure quantitatively. A coupled system of a cracked Timoshenko beam with a pair of PZT patches bonded on the top and bottom surfaces has been considered, where the bonding layers are assumed as a Kelvin-Voigt material. The shear lag model is introduced to describe the load transfer between the PZT patches and the beam structure. The beam crack is simulated as a massless torsional spring; the dynamic equations of the coupled system are derived, which include the crack information and the inertial forces of both PZT patches and adhesive layers. According to the boundary conditions and continuity conditions, the analytical expression of the admittance of PZT patch is obtained. In the case study, the influences of crack and the inertial forces of PZT patches are analyzed. The results show that: (1) the inertial forces affects significantly in high frequency band; and (2) the use of appropriate frequency range can improve the accuracy of damage identification. PMID:22164017

Methodologies for Adaptive Flight Envelope Estimation and Protection

NASA Technical Reports Server (NTRS)

Tang, Liang; Roemer, Michael; Ge, Jianhua; Crassidis, Agamemnon; Prasad, J. V. R.; Belcastro, Christine

2009-01-01

This paper reports the latest development of several techniques for adaptive flight envelope estimation and protection system for aircraft under damage upset conditions. Through the integration of advanced fault detection algorithms, real-time system identification of the damage/faulted aircraft and flight envelop estimation, real-time decision support can be executed autonomously for improving damage tolerance and flight recoverability. Particularly, a bank of adaptive nonlinear fault detection and isolation estimators were developed for flight control actuator faults; a real-time system identification method was developed for assessing the dynamics and performance limitation of impaired aircraft; online learning neural networks were used to approximate selected aircraft dynamics which were then inverted to estimate command margins. As off-line training of network weights is not required, the method has the advantage of adapting to varying flight conditions and different vehicle configurations. The key benefit of the envelope estimation and protection system is that it allows the aircraft to fly close to its limit boundary by constantly updating the controller command limits during flight. The developed techniques were demonstrated on NASA s Generic Transport Model (GTM) simulation environments with simulated actuator faults. Simulation results and remarks on future work are presented.

Identification of Physiological Substrates and Binding Partners of the Plant Mitochondrial Protease FTSH4 by the Trapping Approach.

PubMed

Opalińska, Magdalena; Parys, Katarzyna; Jańska, Hanna

2017-11-18

Maintenance of functional mitochondria is vital for optimal cell performance and survival. This is accomplished by distinct mechanisms, of which preservation of mitochondrial protein homeostasis fulfills a pivotal role. In plants, inner membrane-embedded i -AAA protease, FTSH4, contributes to the mitochondrial proteome surveillance. Owing to the limited knowledge of FTSH4's in vivo substrates, very little is known about the pathways and mechanisms directly controlled by this protease. Here, we applied substrate trapping coupled with mass spectrometry-based peptide identification in order to extend the list of FTSH4's physiological substrates and interaction partners. Our analyses revealed, among several putative targets of FTSH4, novel (mitochondrial pyruvate carrier 4 (MPC4) and Pam18-2) and known (Tim17-2) substrates of this protease. Furthermore, we demonstrate that FTSH4 degrades oxidatively damaged proteins in mitochondria. Our report provides new insights into the function of FTSH4 in the maintenance of plant mitochondrial proteome.

Identification of Physiological Substrates and Binding Partners of the Plant Mitochondrial Protease FTSH4 by the Trapping Approach

PubMed Central

Parys, Katarzyna; Jańska, Hanna

2017-01-01

Maintenance of functional mitochondria is vital for optimal cell performance and survival. This is accomplished by distinct mechanisms, of which preservation of mitochondrial protein homeostasis fulfills a pivotal role. In plants, inner membrane-embedded i-AAA protease, FTSH4, contributes to the mitochondrial proteome surveillance. Owing to the limited knowledge of FTSH4’s in vivo substrates, very little is known about the pathways and mechanisms directly controlled by this protease. Here, we applied substrate trapping coupled with mass spectrometry-based peptide identification in order to extend the list of FTSH4’s physiological substrates and interaction partners. Our analyses revealed, among several putative targets of FTSH4, novel (mitochondrial pyruvate carrier 4 (MPC4) and Pam18-2) and known (Tim17-2) substrates of this protease. Furthermore, we demonstrate that FTSH4 degrades oxidatively damaged proteins in mitochondria. Our report provides new insights into the function of FTSH4 in the maintenance of plant mitochondrial proteome. PMID:29156584

Molecular identification of species of Taenia causing bovine cysticercosis in Ethiopia.

PubMed

Hailemariam, Z; Nakao, M; Menkir, S; Lavikainen, A; Iwaki, T; Yanagida, T; Okamoto, M; Ito, A

2014-09-01

Bovine cysticercosis causing damage to the beef industry is closely linked to human taeniasis due to Taenia saginata. In African countries, Taenia spp. from wildlife are also involved as possible sources of infections in livestock. To identify the aetiological agents of bovine cysticercosis in Ethiopia, cysticerci were collected from 41 cattle slaughtered in the eastern and central areas during 2010-2012. A single cysticercus per animal was subjected to the polymerase chain reaction (PCR)-based DNA sequencing of mitochondrial cytochrome c oxidase subunit 1 gene, and the resultant sequence was compared with those of members of the genus Taenia. Although 38 out of 41 cysticerci (92.7%) were identified as T. saginata, three samples (7.3%) showed the hitherto unknown sequences of Taenia sp., which is distantly related to Taenia solium, Taenia arctos and Taenia ovis. Old literatures suggest it to be Taenia hyaenae, but morphological identification of species could not be completed by observing only the larval samples.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weisz, Daniel A.; Gross, Michael L.; Pakrasi, Himadri B.

Photosystem II (PSII) is a photosynthetic membrane-protein complex that undergoes an intricate, tightly regulated cycle of assembly, damage, and repair. The available crystal structures of cyanobacterial PSII are an essential foundation for understanding PSII function, but nonetheless provide a snapshot only of the active complex. To study aspects of the entire PSII life-cycle, mass spectrometry (MS) has emerged as a powerful tool that can be used in conjunction with biochemical techniques. In this article, we present the MS-based approaches that are used to study PSII composition, dynamics, and structure, and review the information about the PSII life-cycle that has beenmore » gained by these methods. This information includes the composition of PSII subcomplexes, discovery of accessory PSII proteins, identification of post-translational modifications and quantification of their changes under various conditions, determination of the binding site of proteins not observed in PSII crystal structures, conformational changes that underlie PSII functions, and identification of water and oxygen channels within PSII. Lastly, we conclude with an outlook for the opportunity of future MS contributions to PSII research.« less

Damage tolerance modeling and validation of a wireless sensory composite panel for a structural health monitoring system

NASA Astrophysics Data System (ADS)

Talagani, Mohamad R.; Abdi, Frank; Saravanos, Dimitris; Chrysohoidis, Nikos; Nikbin, Kamran; Ragalini, Rose; Rodov, Irena

2013-05-01

The paper proposes the diagnostic and prognostic modeling and test validation of a Wireless Integrated Strain Monitoring and Simulation System (WISMOS). The effort verifies a hardware and web based software tool that is able to evaluate and optimize sensorized aerospace composite structures for the purpose of Structural Health Monitoring (SHM). The tool is an extension of an existing suite of an SHM system, based on a diagnostic-prognostic system (DPS) methodology. The goal of the extended SHM-DPS is to apply multi-scale nonlinear physics-based Progressive Failure analyses to the "as-is" structural configuration to determine residual strength, remaining service life, and future inspection intervals and maintenance procedures. The DPS solution meets the JTI Green Regional Aircraft (GRA) goals towards low weight, durable and reliable commercial aircraft. It will take advantage of the currently developed methodologies within the European Clean sky JTI project WISMOS, with the capability to transmit, store and process strain data from a network of wireless sensors (e.g. strain gages, FBGA) and utilize a DPS-based methodology, based on multi scale progressive failure analysis (MS-PFA), to determine structural health and to advice with respect to condition based inspection and maintenance. As part of the validation of the Diagnostic and prognostic system, Carbon/Epoxy ASTM coupons were fabricated and tested to extract the mechanical properties. Subsequently two composite stiffened panels were manufactured, instrumented and tested under compressive loading: 1) an undamaged stiffened buckling panel; and 2) a damaged stiffened buckling panel including an initial diamond cut. Next numerical Finite element models of the two panels were developed and analyzed under test conditions using Multi-Scale Progressive Failure Analysis (an extension of FEM) to evaluate the damage/fracture evolution process, as well as the identification of contributing failure modes. The comparisons between predictions and test results were within 10% accuracy.

Manual of downburst identification for Project NIMROD. [atmospheric circulation

NASA Technical Reports Server (NTRS)

Fujita, T. T.

1978-01-01

Aerial photography, Doppler radar, and satellite infrared imagery are used in the two year National Intensive Meteorological Research on Downburst (NIMROD) project to provide large area mapping of strong downdrafts that induce an outward burst of damaging winds over or near the earth. Topics discussed include scales of thunderstorm outflow; aerial photographs of downburst damage; microbursts and aviation hazards; radar echo characteristics; infrared imagery from GOES/SMS; and downburts-tornado relationships. Color maps of downbursts and tornadoes are included.

IBT-based quantitative proteomics identifies potential regulatory proteins involved in pigmentation of purple sea cucumber, Apostichopus japonicus.

PubMed

Xing, Lili; Sun, Lina; Liu, Shilin; Li, Xiaoni; Zhang, Libin; Yang, Hongsheng

2017-09-01

Sea cucumbers are an important economic species and exhibit high yield value among aquaculture animals. Purple sea cucumbers are very rare and beautiful and have stable hereditary patterns. In this study, isobaric tags (IBT) were first used to reveal the molecular mechanism of pigmentation in the body wall of the purple sea cucumber. We analyzed the proteomes of purple sea cucumber in early pigmentation stage (Pa), mid pigmentation stage (Pb) and late pigmentation stage (Pc), resulting in the identification of 5580 proteins, including 1099 differentially expressed proteins in Pb: Pa and 339 differentially expressed proteins in Pc: Pb. GO and KEGG analyses revealed possible differentially expressed proteins, including"melanogenesis", "melanosome", "melanoma", "pigment-biosynthetic process", "Epidermis development", "Ras-signaling pathway", "Wnt-signaling pathway", "response to UV light", and "tyrosine metabolism", involved in pigment synthesis and regulation in purple sea cucumbers. The large number of differentially expressed proteins identified here should be highly useful in further elucidating the mechanisms underlying pigmentation in sea cucumbers. Furthermore, these results may also provide the base for further identification of proteins involved in resistance mechanisms against melanoma, albinism, UV damage, and other diseases in sea cucumbers. Copyright © 2017. Published by Elsevier Inc.

A new debris sensor based on dual excitation sources for online debris monitoring

NASA Astrophysics Data System (ADS)

Hong, Wei; Wang, Shaoping; Tomovic, Mileta M.; Liu, Haokuo; Wang, Xingjian

2015-09-01

Mechanical systems could be severely damaged by loose debris generated through wear processes between contact surfaces. Hence, debris detection is necessary for effective fault diagnosis, life prediction, and prevention of catastrophic failures. This paper presents a new in-line debris sensor for hydraulic systems based on dual excitation sources. The proposed sensor makes magnetic lines more concentrated while at the same time improving magnetic field uniformity. As a result the sensor has higher sensitivity and improved precision. This paper develops the sensor model, discusses sensor structural features, and introduces a measurement method for debris size identification. Finally, experimental verification is presented indicating that that the sensor can effectively detect 81 μm (cube) or larger particles in 12 mm outside diameter (OD) organic glass pipe.

White matter tract signatures of impaired social cognition in frontotemporal lobar degeneration

PubMed Central

Downey, Laura E.; Mahoney, Colin J.; Buckley, Aisling H.; Golden, Hannah L.; Henley, Susie M.; Schmitz, Nicole; Schott, Jonathan M.; Simpson, Ivor J.; Ourselin, Sebastien; Fox, Nick C.; Crutch, Sebastian J.; Warren, Jason D.

2015-01-01

Impairments of social cognition are often leading features in frontotemporal lobar degeneration (FTLD) and likely to reflect large-scale brain network disintegration. However, the neuroanatomical basis of impaired social cognition in FTLD and the role of white matter connections have not been defined. Here we assessed social cognition in a cohort of patients representing two core syndromes of FTLD, behavioural variant frontotemporal dementia (bvFTD; n = 29) and semantic variant primary progressive aphasia (svPPA; n = 15), relative to healthy older individuals (n = 37) using two components of the Awareness of Social Inference Test, canonical emotion identification and sarcasm identification. Diffusion tensor imaging (DTI) was used to derive white matter tract correlates of social cognition performance and compared with the distribution of grey matter atrophy on voxel-based morphometry. The bvFTD and svPPA groups showed comparably severe deficits for identification of canonical emotions and sarcasm, and these deficits were correlated with distributed and overlapping white matter tract alterations particularly affecting frontotemporal connections in the right cerebral hemisphere. The most robust DTI associations were identified in white matter tracts linking cognitive and evaluative processing with emotional responses: anterior thalamic radiation, fornix (emotion identification) and uncinate fasciculus (sarcasm identification). DTI associations of impaired social cognition were more consistent than corresponding grey matter associations. These findings delineate a brain network substrate for the social impairment that characterises FTLD syndromes. The findings further suggest that DTI can generate sensitive and functionally relevant indexes of white matter damage in FTLD, with potential to transcend conventional syndrome boundaries. PMID:26236629

Optical stimulation of the facial nerve: a surgical tool?

NASA Astrophysics Data System (ADS)

Richter, Claus-Peter; Teudt, Ingo Ulrik; Nevel, Adam E.; Izzo, Agnella D.; Walsh, Joseph T., Jr.

2008-02-01

One sequela of skull base surgery is the iatrogenic damage to cranial nerves. Devices that stimulate nerves with electric current can assist in the nerve identification. Contemporary devices have two main limitations: (1) the physical contact of the stimulating electrode and (2) the spread of the current through the tissue. In contrast to electrical stimulation, pulsed infrared optical radiation can be used to safely and selectively stimulate neural tissue. Stimulation and screening of the nerve is possible without making physical contact. The gerbil facial nerve was irradiated with 250-μs-long pulses of 2.12 μm radiation delivered via a 600-μm-diameter optical fiber at a repetition rate of 2 Hz. Muscle action potentials were recorded with intradermal electrodes. Nerve samples were examined for possible tissue damage. Eight facial nerves were stimulated with radiant exposures between 0.71-1.77 J/cm2, resulting in compound muscle action potentials (CmAPs) that were simultaneously measured at the m. orbicularis oculi, m. levator nasolabialis, and m. orbicularis oris. Resulting CmAP amplitudes were 0.3-0.4 mV, 0.15-1.4 mV and 0.3-2.3 mV, respectively, depending on the radial location of the optical fiber and the radiant exposure. Individual nerve branches were also stimulated, resulting in CmAP amplitudes between 0.2 and 1.6 mV. Histology revealed tissue damage at radiant exposures of 2.2 J/cm2, but no apparent damage at radiant exposures of 2.0 J/cm2.

Proteomic-based identification of Apg-2 as a therapeutic target for chronic myeloid leukemia.

PubMed

Li, Yajuan; Chen, Xi; Shi, Meng; Wang, Haixia; Cao, Weixi; Wang, Xiaozhong; Li, Chunli; Feng, Wenli

2013-12-01

The oncogenic BCR/ABL tyrosine kinase induces constitutive enhanced "spontaneous" DNA damage and unfaithful repair in Philadelphia chromosome positive leukemia cells. Here, we investigated the changes of protein profile in H2O2-induced DNA damage/repair in BaF3-MIGR1 and BaF3-BCR/ABL cells through a proteomic strategy consisting of two-dimensional gel electrophoresis (2-DE) coupled with MALDI-TOF mass spectrometry. In total, 41 spots were differentially expressed and 13 proteins were identified with further MS analysis. Two essential proteins, Proto-oncogene tyrosine-protein kinase ABL1 (c-ABL) and Heat shock 70kDa protein 4 (Apg-2), were confirmed by Western blot and showed consistent changes with proteomic results. Moreover, functional analysis demonstrated that inhibition of Apg-2 not only decreased cell proliferation, but also induced cell apoptosis in BCR/ABL positive cells (BaF3-BCR/ABL, BaF3-BCR/ABL(T315I)). We also proved that Apg-2 inhibition aggravated H2O2 induced damage in BCR/ABL positive cells, and enhanced the sensitivity of BaF3-BCR/ABL(T315I) to STI571. Taken together, the findings in this work provide us with some clues to a better understanding of the molecular mechanisms underlying BCR/ABL in the DNA damage/repair processes and demonstrated that Apg-2 would be a valid target for anti-leukemia drug development. © 2013.

Multifunctional Ebselen drug functions through the activation of DNA damage response and alterations in nuclear proteins.

PubMed

Azad, Gajendra K; Balkrishna, Shah Jaimin; Sathish, Narayanan; Kumar, Sangit; Tomar, Raghuvir S

2012-01-15

Several studies have demonstrated that Ebselen is an anti-inflammatory and anti-oxidative agent. Contrary to this, studies have also shown a high degree of cellular toxicity associated with Ebselen usage, the underlying mechanism of which remains less understood. In this study we have attempted to identify a possible molecular mechanism behind the above by investigating the effects of Ebselen on Saccharomyces cerevisiae. Significant growth arrest was documented in yeast cells exposed to Ebselen similar to that seen in presence of DNA damaging agents (including methyl methane sulfonate [MMS] and hydroxy urea [HU]). Furthermore, mutations in specific lysine residues in the histone H3 tail (H3 K56R) resulted in increased sensitivity of yeast cells to Ebselen presumably due to alterations in post-translational modifications of histone proteins towards regulating replication and DNA damage repair. Our findings suggest that Ebselen functions through activation of DNA damage response, alterations in histone modifications, activation of checkpoint kinase pathway and derepression of ribonucleotide reductases (DNA repair genes) which to the best of our knowledge is being reported for the first time. Interestingly subsequent to Ebselen exposure there were changes in global yeast protein expression and specific histone modifications, identification of which is expected to reveal a fundamental cellular mechanism underlying the action of Ebselen. Taken together these observations will help to redesign Ebselen-based therapy in clinical trials. Copyright © 2011 Elsevier Inc. All rights reserved.

Structural Modeling Using "Scanning and Mapping" Technique

NASA Technical Reports Server (NTRS)

Amos, Courtney L.; Dash, Gerald S.; Shen, J. Y.; Ferguson, Frederick; Noga, Donald F. (Technical Monitor)

2000-01-01

Supported by NASA Glenn Center, we are in the process developing a structural damage diagnostic and monitoring system for rocket engines, which consists of five modules: Structural Modeling, Measurement Data Pre-Processor, Structural System Identification, Damage Detection Criterion, and Computer Visualization. The function of the system is to detect damage as it is incurred by the engine structures. The scientific principle to identify damage is to utilize the changes in the vibrational properties between the pre-damaged and post-damaged structures. The vibrational properties of the pre-damaged structure can be obtained based on an analytic computer model of the structure. Thus, as the first stage of the whole research plan, we currently focus on the first module - Structural Modeling. Three computer software packages are selected, and will be integrated for this purpose. They are PhotoModeler-Pro, AutoCAD-R14, and MSC/NASTRAN. AutoCAD is the most popular PC-CAD system currently available in the market. For our purpose, it plays like an interface to generate structural models of any particular engine parts or assembly, which is then passed to MSC/NASTRAN for extracting structural dynamic properties. Although AutoCAD is a powerful structural modeling tool, the complexity of engine components requires a further improvement in structural modeling techniques. We are working on a so-called "scanning and mapping" technique, which is a relatively new technique. The basic idea is to producing a full and accurate 3D structural model by tracing on multiple overlapping photographs taken from different angles. There is no need to input point positions, angles, distances or axes. Photographs can be taken by any types of cameras with different lenses. With the integration of such a modeling technique, the capability of structural modeling will be enhanced. The prototypes of any complex structural components will be produced by PhotoModeler first based on existing similar components, then passed to AutoCAD for modification and correction of any discrepancies seen in the Photomodeler version of the 3Dmodel. These three software packages are fully compatible. The DXF file can be used to transfer drawings among those packages. To begin this entire process, we are using a small replica of an actual engine blade as a test object. This paper introduces the accomplishment of our recent work.

An optimal baseline selection methodology for data-driven damage detection and temperature compensation in acousto-ultrasonics

NASA Astrophysics Data System (ADS)

Torres-Arredondo, M.-A.; Sierra-Pérez, Julián; Cabanes, Guénaël

2016-05-01

The process of measuring and analysing the data from a distributed sensor network all over a structural system in order to quantify its condition is known as structural health monitoring (SHM). For the design of a trustworthy health monitoring system, a vast amount of information regarding the inherent physical characteristics of the sources and their propagation and interaction across the structure is crucial. Moreover, any SHM system which is expected to transition to field operation must take into account the influence of environmental and operational changes which cause modifications in the stiffness and damping of the structure and consequently modify its dynamic behaviour. On that account, special attention is paid in this paper to the development of an efficient SHM methodology where robust signal processing and pattern recognition techniques are integrated for the correct interpretation of complex ultrasonic waves within the context of damage detection and identification. The methodology is based on an acousto-ultrasonics technique where the discrete wavelet transform is evaluated for feature extraction and selection, linear principal component analysis for data-driven modelling and self-organising maps for a two-level clustering under the principle of local density. At the end, the methodology is experimentally demonstrated and results show that all the damages were detectable and identifiable.

Identification of evolutionarily conserved DNA damage response genes that alter sensitivity to cisplatin

PubMed Central

Gaponova, Anna V.; Deneka, Alexander Y.; Beck, Tim N.; Liu, Hanqing; Andrianov, Gregory; Nikonova, Anna S.; Nicolas, Emmanuelle; Einarson, Margret B.; Golemis, Erica A.; Serebriiskii, Ilya G.

2017-01-01

Ovarian, head and neck, and other cancers are commonly treated with cisplatin and other DNA damaging cytotoxic agents. Altered DNA damage response (DDR) contributes to resistance of these tumors to chemotherapies, some targeted therapies, and radiation. DDR involves multiple protein complexes and signaling pathways, some of which are evolutionarily ancient and involve protein orthologs conserved from yeast to humans. To identify new regulators of cisplatin-resistance in human tumors, we integrated high throughput and curated datasets describing yeast genes that regulate sensitivity to cisplatin and/or ionizing radiation. Next, we clustered highly validated genes based on chemogenomic profiling, and then mapped orthologs of these genes in expanded genomic networks for multiple metazoans, including humans. This approach identified an enriched candidate set of genes involved in the regulation of resistance to radiation and/or cisplatin in humans. Direct functional assessment of selected candidate genes using RNA interference confirmed their activity in influencing cisplatin resistance, degree of γH2AX focus formation and ATR phosphorylation, in ovarian and head and neck cancer cell lines, suggesting impaired DDR signaling as the driving mechanism. This work enlarges the set of genes that may contribute to chemotherapy resistance and provides a new contextual resource for interpreting next generation sequencing (NGS) genomic profiling of tumors. PMID:27863405

Remote monitoring of bond line defects between a composite panel and a stiffener using distributed piezoelectric sensors

NASA Astrophysics Data System (ADS)

Yu, Xudong; Fan, Zheng; Puliyakote, Sreedhar; Castaings, Michel

2018-03-01

Structural health monitoring (SHM) using ultrasonic guided waves has proven to be attractive for the identification of damage in composite plate-like structures, due to its realization of both significant propagation distances and reasonable sensitivity to defects. However, topographical features such as bends, lap joints, and bonded stiffeners are often encountered in these structures, and they are susceptible to various types of defects as a consequence of stress concentration and cyclic loading during the service life. Therefore, the health condition of such features has to be assessed effectively to ensure the safe operation of the entire structure. This paper proposes a novel feature guided wave (FGW) based SHM strategy, in which proper FGWs are exploited as a screening tool to rapidly interrogate the representative stiffener-adhesive bond-composite skin assembly. An array of sensors permanently attached to the vicinity of the feature is used to capture scattered waves from the localized damage occurring in the bond line. This technique is combined with an imaging approach, and the damage reconstruction is achieved by the synthetic focusing algorithm using these scattered signals. The proposed SHM scheme is implemented in both the 3D finite element simulation and the experiment, and the results are in good agreement, demonstrating the feasibility of such SHM strategy.

The engine maintenance scheduling by using reliability centered maintenance method and the identification of 5S application in PT. XYZ

NASA Astrophysics Data System (ADS)

Sembiring, N.; Panjaitan, N.; Saragih, A. F.

2018-02-01

PT. XYZ is a manufacturing company that produces fresh fruit bunches (FFB) to Crude Palm Oil (CPO) and Palm Kernel Oil (PKO). PT. XYZ consists of six work stations: receipt station, sterilizing station, thressing station, pressing station, clarification station, and kernelery station. So far, the company is still implementing corrective maintenance maintenance system for production machines where the machine repair is done after damage occurs. Problems at PT. XYZ is the absence of scheduling engine maintenance in a planned manner resulting in the engine often damaged which can disrupt the smooth production. Another factor that is the problem in this research is the kernel station environment that becomes less convenient for operators such as there are machines and equipment not used in the production area, slippery, muddy, scattered fibers, incomplete use of PPE, and lack of employee discipline. The most commonly damaged machine is in the seed processing station (kernel station) which is cake breaker conveyor machine. The solution of this problem is to propose a schedule plan for maintenance of the machine by using the method of reliability centered maintenance and also the application of 5S. The result of the application of Reliability Centered maintenance method is obtained four components that must be treated scheduled (time directed), namely: for bearing component is 37 days, gearbox component is 97 days, CBC pen component is 35 days and conveyor pedal component is 32 days While after identification the application of 5S obtained the proposed corporate environmental improvement measures in accordance with the principles of 5S where unused goods will be moved from the production area, grouping goods based on their use, determining the procedure of cleaning the production area, conducting inspection in the use of PPE, and making 5S slogans.

Stress Distribution and Damage Mode of Ceramic-Dentin Bilayer Systems

NASA Astrophysics Data System (ADS)

Kurtoglu, Cem; Demiroz, S. Suna; Mehmetov, Emirullah; Uysal, Hakan

The aim of this study was to evaluate the damage modes of ceramic systems bonded to dentin under Hertzian indentation. Single-cycle Hertzian contact test over 150-850 N load range was applied randomly to 210 ceramic-dentin bilayer disc specimens of zirconia or IPS Empress II -1 mm, -1.5 mm and of feldspathic porcelain -1 mm, -1.5 mm, -2 mm. Optical microscopy was employed for the identification of quasiplastic mode and radial cracks. Finite element analysis was used to analyze the stress distribution. Our results showed that the degree of damage in both modes evolved progressively and the origin changed with contact load. Stress location and value were consistent with the mechanical test results. It was concluded that microstructure and thickness of the material have a significant effect on the damage modes of ceramic layer systems.

Monitoring fatigue damage in carbon fiber composites using an acoustic impact technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haque, A.; Raju, P.K.

1998-06-01

The acoustic impact technique (AIT) of nondestructive testing (NDT) has been used to identify the damage that results from the compressive and tension-compression cycle loading around a circular notch of quasiisotropic carbon-fiber composites. This method involves applying a low velocity impact to the test specimen and evaluating the resulting localized acoustic response. Results indicate that AIT can be applied for identification of both compressive and fatigue damage in composite laminates. The gross area of compressive and fatigue damage is detected through an increase in the pulse width, and a decrease in the amplitude, of the force-time signal. The response obtainedmore » in AIT is sensitive to the frequency of the impactor and the amplitude of the impact force and requires careful monitoring of these values to achieve repeatability of results.« less

Nondestructive damage evaluation in ceramic matrix composites for aerospace applications.

PubMed

Dassios, Konstantinos G; Kordatos, Evangelos Z; Aggelis, Dimitrios G; Matikas, Theodore E

2013-01-01

Infrared thermography (IRT) and acoustic emission (AE) are the two major nondestructive methodologies for evaluating damage in ceramic matrix composites (CMCs) for aerospace applications. The two techniques are applied herein to assess and monitor damage formation and evolution in a SiC-fiber reinforced CMC loaded under cyclic and fatigue loading. The paper explains how IRT and AE can be used for the assessment of the material's performance under fatigue. IRT and AE parameters are specifically used for the characterization of the complex damage mechanisms that occur during CMC fracture, and they enable the identification of the micromechanical processes that control material failure, mainly crack formation and propagation. Additionally, these nondestructive parameters help in early prediction of the residual life of the material and in establishing the fatigue limit of materials rapidly and accurately.

Impedance-Based Structural Health Monitoring for Composite Laminates at Cryogenic Environments

NASA Technical Reports Server (NTRS)

Tseng, Kevin

2003-01-01

One of the important ways of increasing the payload in a reusable launch vehicle (RLV) is to replace heavy metallic materials by lightweight composite laminates. Among various parts and systems of the RLV, this project focuses on tanks containing cryogenic fuel. Historically, aluminum alloys have been used as the materials to construct fuel tanks for launch vehicles. To replace aluminum alloys with composite laminates or honeycomb materials, engineers have to make sure that the composites are free of defects before, during, and after launch. In addition to robust design and manufacturing procedures, the performance of the composite structures needs to be monitored constantly.In recent years, the impedance-based health monitoring technique has shown its promise in many applications. This technique makes use of the special properties of smart piezoelectric materials to identify the change of material properties due to the nucleation and progression of damage. The piezoceramic patch serves as a sensor and an actuator simultaneously. The piezoelectric patch is bonded onto an existing structure or embedded into a new structure and electrically excited at high frequencies. The signature (impedance or admittance) is extracted as a function of the exciting frequency and is compared with the baseline signature of the healthy state. The damage is quantified using root mean square deviation (RMSD) in the impedance signatures with respect to the baseline signature. A major advantage of this technique is that the procedure is nondestructive in nature and does not perturb the properties and performance of the materials and structures. This project aims at applying the impedance-based nondestructive testing technique to the damage identification of composite laminates at cryogenic temperature.

Damage of composite structures: Detection technique, dynamic response and residual strength

NASA Astrophysics Data System (ADS)

Lestari, Wahyu

2001-10-01

Reliable and accurate health monitoring techniques can prevent catastrophic failures of structures. Conventional damage detection methods are based on visual or localized experimental methods and very often require prior information concerning the vicinity of the damage or defect. The structure must also be readily accessible for inspections. The techniques are also labor intensive. In comparison to these methods, health-monitoring techniques that are based on the structural dynamic response offers unique information on failure of structures. However, systematic relations between the experimental data and the defect are not available and frequently, the number of vibration modes needed for an accurate identification of defects is much higher than the number of modes that can be readily identified in the experiment. These motivated us to develop an experimental data based detection method with systematic relationships between the experimentally identified information and the analytical or mathematical model representing the defective structures. The developed technique use changes in vibrational curvature modes and natural frequencies. To avoid misinterpretation of the identified information, we also need to understand the effects of defects on the structural dynamic response prior to developing health-monitoring techniques. In this thesis work we focus on two type of defects in composite structures, namely delamination and edge notch like defect. Effects of nonlinearity due to the presence of defect and due to the axial stretching are studied for beams with delamination. Once defects are detected in a structure, next concern is determining the effects of the defects on the strength of the structure and its residual stiffness under dynamic loading. In this thesis, energy release rate due to dynamic loading in a delaminated structure is studied, which will be a foundation toward determining the residual strength of the structure.

Sub-Frequency Interval Approach in Electromechanical Impedance Technique for Concrete Structure Health Monitoring

PubMed Central

Yang, Yaowen; Divsholi, Bahador Sabet

2010-01-01

The electromechanical (EM) impedance technique using piezoelectric lead zirconate titanate (PZT) transducers for structural health monitoring (SHM) has attracted considerable attention in various engineering fields. In the conventional EM impedance technique, the EM admittance of a PZT transducer is used as a damage indicator. Statistical analysis methods such as root mean square deviation (RMSD) have been employed to associate the damage level with the changes in the EM admittance signatures, but it is difficult to determine the location of damage using such methods. This paper proposes a new approach by dividing the large frequency (30–400 kHz) range into sub-frequency intervals and calculating their respective RMSD values. The RMSD of the sub-frequency intervals (RMSD-S) will be used to study the severity and location of damage. An experiment is carried out on a real size concrete structure subjected to artificial damage. It is observed that damage close to the PZT changes the high frequency range RMSD-S significantly, while the damage far away from the PZT changes the RMSD-S in the low frequency range significantly. The relationship between the frequency range and the PZT sensing region is also presented. Finally, a damage identification scheme is proposed to estimate the location and severity of damage in concrete structures. PMID:22163548

Oxidant-induced damage to equine erythrocytes from exposure to Pistacia atlantica, Pistacia terebinthus, and Pistacia chinensis.

PubMed

Walter, Kyla M; Moore, Caroline E; Bozorgmanesh, Rana; Magdesian, K Gary; Woods, Leslie W; Puschner, Birgit

2014-11-01

Two horses were referred for methemoglobinemia and hemolytic anemia following 5 acute deaths in their herd from an unidentified toxin source. Horses have a greater risk than other mammalian species of developing methemoglobinemia and hemolytic anemia following ingestion of oxidizing toxins, due to deficiencies in the mechanisms that protect against oxidative damage in erythrocytes. Their susceptibility to oxidative erythrocyte damage is evident in the numerous cases of red maple (Acer rubrum) toxicosis. The suspected toxins causing A. rubrum toxicosis are tannic acid, gallic acid, and a metabolite of gallic acid, pyrogallol. These compounds can be found in a variety of plants, posing a risk to equine health. In order to quickly identify toxin sources, 2 rapid in vitro assays were developed to screen plant extracts for the ability to induce methemoglobin formation or cause hemolysis in healthy equine donor erythrocytes. The plant extract screening focused on 3 species of the genus Pistacia: P. atlantica, P. terebinthus, and P. chinensis, which were located in the horse pasture. Extracts of the seeds and leaves of each species induced methemoglobin formation and resulted in hemolysis, with seed extracts having greater potency. The in vitro assays used in the current study provide a useful diagnostic method for the rapid identification of oxidizing agents from unidentified sources. There is no effective treatment for oxidative erythrocyte damage in horses, making rapid identification and removal of the source essential for the prevention of poisoning. © 2014 The Author(s).

Oxidant-induced damage to equine erythrocytes from exposure to Pistacia atlantica, Pistacia terebinthus, and Pistacia chinensis

PubMed Central

Walter, Kyla M.; Moore, Caroline E.; Bozorgmanesh, Rana; Magdesian, K. Gary; Woods, Leslie W.; Puschner, Birgit

2017-01-01

Two horses were referred for methemoglobinemia and hemolytic anemia following 5 acute deaths in their herd from an unidentified toxin source. Horses have a greater risk than other mammalian species of developing methemoglobinemia and hemolytic anemia following ingestion of oxidizing toxins, due to deficiencies in the mechanisms that protect against oxidative damage in erythrocytes. Their susceptibility to oxidative erythrocyte damage is evident in the numerous cases of red maple (Acer rubrum) toxicosis. The suspected toxins causing A. rubrum toxicosis are tannic acid, gallic acid, and a metabolite of gallic acid, pyrogallol. These compounds can be found in a variety of plants, posing a risk to equine health. In order to quickly identify toxin sources, 2 rapid in vitro assays were developed to screen plant extracts for the ability to induce methemoglobin formation or cause hemolysis in healthy equine donor erythrocytes. The plant extract screening focused on 3 species of the genus Pistacia: P. atlantica, P. terebinthus, and P. chinensis, which were located in the horse pasture. Extracts of the seeds and leaves of each species induced methemoglobin formation and resulted in hemolysis, with seed extracts having greater potency. The in vitro assays used in the current study provide a useful diagnostic method for the rapid identification of oxidizing agents from unidentified sources. There is no effective treatment for oxidative erythrocyte damage in horses, making rapid identification and removal of the source essential for the prevention of poisoning. PMID:25227420

Concrete Cutting Refinement for Crater Repair

DTIC Science & Technology

2015-08-01

Identification of damage sustained to the airfield operating surfaces, 2. Selection of minimum pavement surface areas required to support air- craft...also studied to identify the appropriate lineup and stop locations to achieve the desired overcut lengths. Edwards et al. (2015) recommends overcut

Costs and revenues associated with overweight trucks in Indiana.

DOT National Transportation Integrated Search

2012-11-01

This study estimated highway pavement and bridge damage costs, and analyzed the adequacy of permit revenues to cover these : costs. The study began with an extensive review of the literature on the subject, thus facilitating identification of the gap...

A damage identification procedure for bridge structures with energy dissipation devices.

DOT National Transportation Integrated Search

2008-08-01

The importance of bridge structures in an era of natural and man-made risks is unquestionable. Bridges represent the keystone of an efficient transport infrastructure needed in full operation conditions when a disastrous event strikes. After natural ...

PoliRisposta: Overcoming present limits of flood damage data

NASA Astrophysics Data System (ADS)

Molinari, Daniela; Mazuran, Mirjana; Arias, Carolina; Minucci, Guido; Atun, Funda; Ardagna, Danilo

2014-05-01

Already in the Fifties, US researchers identified the main weakness of flood records in the inadequacy of flood damage data. The recent seminar "Flood damage survey and assessment: which priorities for future research and practice?", held at Politecnico di Milano on 24-25 January 2012, highlighted that poor and insufficient flood loss data is still a matter of concern. In detail, participants concluded that the lack of damage data and of innovative approaches for their analysis (e.g. multivariate approaches, data mining) is one of the main causes of the shortcomings of present risk assessment tools; among them: the uncertainty of flood risk predictions and the limited capacity of estimating damages apart from the direct ones to residential sector (i.e. indirect/intangible damages). On the other hand, flood damage data collected in the aftermath of a disastrous event can support a variety of actions besides the validation/definition of damage models: the identification of priorities for intervention during emergencies, the creation of complete event scenarios on the bases of which understating the fragilities of the flooded areas as well as defining compensation schemes. However, few efforts have been addressed so far on the improvement of the way in which data are presently collected and stored. The aim of this presentation is to discuss first results of Poli-RISPOSTA (stRumentI per la protezione civile a Supporto delle POpolazioni nel poST Alluvione), a research project founded by Politecnico di Milano which is just intended to develop tools and procedures for the collection and storage of high quality, consistent and reliable flood damage data. In detail, specific objectives of Poli-RISPOSTA are: - Develop an operational procedure for collecting, storing and analyzing all damage data, in the aftermath of flood event, including: damage to infrastructures and public facilities, damage suffered by citizens and their dwellings and goods, and to economic activities; - Develop educational material and modules for training practitioners in the use of the procedure; - Develop enhanced IT tools (both hardware and software) to support the procedure, easing as much as possible the collection of field data, the creation of databases and the connection between the latter and different regional and municipal databases that already exist for different purposes (from cadastral data, to satellite images, etc.). Results will be discussed with respect to first applications in the Umbria Region (Central Italy). Emphasis will be put on the utility of results for damage modelling, risk mitigation and emergency management.

DNA-damage foci to detect and characterize DNA repair alterations in children treated for pediatric malignancies.

PubMed

Schuler, Nadine; Palm, Jan; Kaiser, Mareike; Betten, Dominik; Furtwängler, Rhoikos; Rübe, Christian; Graf, Norbert; Rübe, Claudia E

2014-01-01

In children diagnosed with cancer, we evaluated the DNA damage foci approach to identify patients with double-strand break (DSB) repair deficiencies, who may overreact to DNA-damaging radio- and chemotherapy. In one patient with Fanconi anemia (FA) suffering relapsing squamous cell carcinomas of the oral cavity we also characterized the repair defect in biopsies of skin, mucosa and tumor. In children with histologically confirmed tumors or leukemias and healthy control-children DSB repair was investigated by counting γH2AX-, 53BP1- and pATM-foci in blood lymphocytes at defined time points after ex-vivo irradiation. This DSB repair capacity was correlated with treatment-related normal-tissue responses. For the FA patient the defective repair was also characterized in tissue biopsies by analyzing DNA damage response proteins by light and electron microscopy. Between tumor-children and healthy control-children we observed significant differences in mean DSB repair capacity, suggesting that childhood cancer is based on genetic alterations affecting DNA repair. Only 1 out of 4 patients with grade-4 normal-tissue toxicities revealed an impaired DSB repair capacity. The defective DNA repair in FA patient was verified in irradiated blood lymphocytes as well as in non-irradiated mucosa and skin biopsies leading to an excessive accumulation of heterochromatin-associated DSBs in rapidly cycling cells. Analyzing human tissues we show that DSB repair alterations predispose to cancer formation at younger ages and affect the susceptibility to normal-tissue toxicities. DNA damage foci analysis of blood and tissue samples allows one to detect and characterize DSB repair deficiencies and enables identification of patients at risk for high-grade toxicities. However, not all treatment-associated normal-tissue toxicities can be explained by DSB repair deficiencies.

A Short-Term Biological Indicator for Long-Term Kidney Damage after Radionuclide Therapy in Mice

PubMed Central

Pellegrini, Giovanni; Siwowska, Klaudia; Haller, Stephanie; Antoine, Daniel J.; Schibli, Roger; Kipar, Anja; Müller, Cristina

2017-01-01

Folate receptor (FR)-targeted radionuclide therapy using folate radioconjugates is of interest due to the expression of the FR in a variety of tumor types. The high renal accumulation of radiofolates presents, however, a risk of radionephropathy. A potential option to address this challenge would be to use radioprotectants, such as amifostine. Methods for early detection of kidney damage that—in this case—cannot be predicted based on dose estimations, would facilitate the development of novel therapies. The aim of this study was, therefore, to assess potentially changing levels of plasma and urine biomarkers and to determine DNA damage at an early stage after radiofolate application. The identification of an early indicator for renal damage in mice would be useful since histological changes become apparent only several months after treatment. Mice were injected with different quantities of 177Lu-folate (10 MBq, 20 MBq and 30 MBq), resulting in mean absorbed kidney doses of ~23 Gy, ~46 Gy and ~69 Gy, respectively, followed by euthanasia two weeks (>85% of the mean renal radiation dose absorbed) or three months later. Whereas all investigated biomarkers remained unchanged, the number of γ-H2AX-positive nuclei in the renal cortex showed an evident dose-dependent increase as compared to control values two weeks after treatment. Comparison with the extent of kidney injury determined by histological changes five to eight months after administration of the same 177Lu-folate activities suggested that the quantitative assessment of double-strand breaks can be used as a biological indicator for long-term radiation effects in the kidneys. This method may, thus, enable faster assessment of radiopharmaceuticals and protective measures by preventing logistically challenging long-term investigations to detect kidney damage. PMID:28635637

Damage detection in composites using nonlinear ultrasonically modulated thermography

NASA Astrophysics Data System (ADS)

Malfense Fierro, G.-P.; Dionysopoulos, D.; Meo, M.; Ciampa, F.

2018-03-01

This paper proposes a novel nonlinear ultrasonically stimulated thermography technique for a quick and reliable assessment of material damage in carbon fibre reinforced plastic (CFRP) composite materials. The proposed nondestructive evaluation (NDE) method requires narrow sweep ultrasonic excitation using contact piezoelectric transducers in order to identify dual excitation frequencies associated with the damage resonance. High-amplitude signals and higher harmonic generation are necessary conditions for an accurate identification of these two input frequencies. Dual periodic excitation using high- and low-frequency input signals was then performed in order to generate frictional heating at the crack location that was measured by an infrared (IR) camera. To validate this concept, an impact damaged CFRP composite panel was tested and the experimental results were compared with traditional flash thermography. A laser vibrometer was used to investigate the response of the material with dual frequency excitation. The proposed nonlinear ultrasonically modulated thermography successfully detected barely visible impact damage in CFRP composites. Hence, it can be considered as an alternative to traditional flash thermography and thermosonics by allowing repeatable detection of damage in composites.

Experimental Investigation of the Acoustic Nonlinear Behavior in Granular Polymer Bonded Explosives with Progressive Fatigue Damage

PubMed Central

Yang, Zhanfeng; Tian, Yong; Li, Weibin; Zhou, Haiqiang; Zhang, Weibin; Li, Jingming

2017-01-01

The measurement of acoustic nonlinear response is known as a promising technique to characterize material micro-damages. In this paper, nonlinear ultrasonic approach is used to characterize the evolution of fatigue induced micro-cracks in polymer bonded explosives. The variations of acoustic nonlinearity with respect to fatigue cycles in the specimens are obtained in this investigation. The present results show a significant increase of acoustic nonlinearity with respect to fatigue cycles. The experimental observation of the correlation between the acoustic nonlinearity and fatigue cycles in carbon/epoxy laminates, verifies that an acoustic nonlinear response can be used to evaluate the progressive fatigue damage in the granular polymer bonded explosives. The sensitivity comparison of nonlinear and linear parameters of ultrasonic waves in the specimens shows that nonlinear acoustic parameters are more promising indicators to fatigue induced micro-damage than linear ones. The feasibility study of the micro-damage assessment of polymer bonded explosives by nonlinear ultrasonic technique in this work can be applied to damage identification, material degradation monitoring, and lifetime prediction of the explosive parts. PMID:28773017

Experimental Investigation of the Acoustic Nonlinear Behavior in Granular Polymer Bonded Explosives with Progressive Fatigue Damage.

PubMed

Yang, Zhanfeng; Tian, Yong; Li, Weibin; Zhou, Haiqiang; Zhang, Weibin; Li, Jingming

2017-06-16

The measurement of acoustic nonlinear response is known as a promising technique to characterize material micro-damages. In this paper, nonlinear ultrasonic approach is used to characterize the evolution of fatigue induced micro-cracks in polymer bonded explosives. The variations of acoustic nonlinearity with respect to fatigue cycles in the specimens are obtained in this investigation. The present results show a significant increase of acoustic nonlinearity with respect to fatigue cycles. The experimental observation of the correlation between the acoustic nonlinearity and fatigue cycles in carbon/epoxy laminates, verifies that an acoustic nonlinear response can be used to evaluate the progressive fatigue damage in the granular polymer bonded explosives. The sensitivity comparison of nonlinear and linear parameters of ultrasonic waves in the specimens shows that nonlinear acoustic parameters are more promising indicators to fatigue induced micro-damage than linear ones. The feasibility study of the micro-damage assessment of polymer bonded explosives by nonlinear ultrasonic technique in this work can be applied to damage identification, material degradation monitoring, and lifetime prediction of the explosive parts.

The Interaction between Checkpoint Kinase 1 (Chk1) and the Minichromosome Maintenance (MCM) Complex Is Required for DNA Damage-induced Chk1 Phosphorylation*

PubMed Central

Han, Xiangzi; Aslanian, Aaron; Fu, Kang; Tsuji, Toshiya; Zhang, Youwei

2014-01-01

Chk1 is an essential mediator of the DNA damage response and cell cycle checkpoint. However, how exactly Chk1 transduces the checkpoint signaling is not fully understood. Here we report the identification of the heterohexamic minichromosome maintenance (MCM) complex that interacts with Chk1 by mass spectrometry. The interaction between Chk1 and the MCM complex was reduced by DNA damage treatment. We show that the MCM complex, at least partially, contributes to the chromatin association of Chk1, allowing for immediate phosphorylation of Chk1 by ataxia telangiectasia mutated and Rad3-related (ATR) in the presence of DNA damage. Further, phosphorylation of Chk1 at ATR sites reduces the interaction between Chk1 and the MCM complex, facilitating chromatin release of phosphorylated Chk1, a critical step in the initiation and amplification of cell cycle checkpoint. Together, these data provide novel insights into the activation of Chk1 in response to DNA damage. PMID:25049228

Identification of the Quality Spot Welding used Non Destructive Test-Ultrasonic Testing: (Effect of Welding Time)

NASA Astrophysics Data System (ADS)

Sifa, A.; Endramawan, T.; Badruzzaman

2017-03-01

Resistance Spot Welding (RSW) is frequently used as one way of welding is used in the manufacturing process, especially in the automotive industry [4][5][6][7]. Several parameters influence the process of welding points. To determine the quality of a welding job needs to be tested, either by damaging or testing without damage, in this study conducted experimental testing the quality of welding or identify quality of the nugget by using Non-Destructive Test (NDT) -Ultrasonic Testing (UT), in which the identification of the quality of the welding is done with parameter thickness of worksheet after welding using NDT-UT with use same material worksheet and have more thickness of worksheet, the thickness of the worksheet single plate 1mm, with the capability of propagation Ultrasonic Testing (UT) standard limited> 3 mm [1], welding process parameters such as the time difference between 1-10s and the welding current of 8 KV, visually Heat Affected Zone ( HAZ ) have different results due to the length of time of welding. UT uses a probe that is used with a frequency of 4 MHz, diameter 10 mm, range 100 and the couplant used is oil. Identification techniques using drop 6dB, with sound velocity 2267 m / s of Fe, with the result that the effect of the Welding time affect the size of the HAZ, identification with the lowest time 1s show results capable identified joined through NDT - UT.

Identification of natural red and purple dyes on textiles by Fiber-optics Reflectance Spectroscopy.

PubMed

Maynez-Rojas, M A; Casanova-González, E; Ruvalcaba-Sil, J L

2017-05-05

Understanding dye chemistry and dye processes is an important issue for studies of cultural heritage collections and science conservation. Fiber Optics Reflectance Spectroscopy (FORS) is a powerful technique, which allows preliminary dye identification, causing no damage or mechanical stress on the artworks subjected to analysis. Some information related to specific light scattering and absorption can be obtained in the UV-visible and infrared range (300-1400nm) and it is possible to discriminate the kind of support fiber in the near infrared region (1000-2500nm). The main spectral features of natural dye fibers samples, such as reflection maxima, inflection points and reflection minima, can be used in the differentiation of various red natural dyes. In this work, a set of dyed references were manufactured following Mexican recipes with red dyes (cochineal and brazilwood) in order to determine the characteristic FORS spectral features of fresh and aged dyed fibers for their identification in historical pieces. Based on these results, twenty-nine indigenous textiles belonging to the National Commission for the Development of Indigenous People of Mexico were studied. Cochineal and brazilwood were successfully identified by FORS in several pieces, as well as the mixture of cochineal and indigo for purple color. Copyright © 2017 Elsevier B.V. All rights reserved.

Improving needle tip identification during ultrasound-guided procedures in anaesthetic practice.

PubMed

Scholten, H J; Pourtaherian, A; Mihajlovic, N; Korsten, H H M; A Bouwman, R

2017-07-01

Ultrasound guidance is becoming standard practice for needle-based interventions in anaesthetic practice, such as vascular access and peripheral nerve blocks. However, difficulties in aligning the needle and the transducer can lead to incorrect identification of the needle tip, possibly damaging structures not visible on the ultrasound screen. Additional techniques specifically developed to aid alignment of needle and probe or identification of the needle tip are now available. In this scoping review, advantages and limitations of the following categories of those solutions are presented: needle guides; alterations to needle or needle tip; three- and four-dimensional ultrasound; magnetism, electromagnetic or GPS systems; optical tracking; augmented (virtual) reality; robotic assistance; and automated (computerised) needle detection. Most evidence originates from phantom studies, case reports and series, with few randomised clinical trials. Improved first-pass success and reduced performance time are the most frequently cited benefits, whereas the need for additional and often expensive hardware is the greatest limitation to widespread adoption. Novice ultrasound users seem to benefit most and great potential lies in education. Future research should focus on reporting relevant clinical parameters to learn which technique will benefit patients most in terms of success and safety. © 2017 The Association of Anaesthetists of Great Britain and Ireland.

A new methodology for earthquake damage assessment (MEDEA) and its application following the Molise Italy earthquake of 31.10.02

NASA Astrophysics Data System (ADS)

Zuccaro, G.; Papa, F.; Spence, R.

2003-04-01

MEDEA is a multi-media tool designed to support earthquake damage assessment teams in Italy, by providing a means to train the technicians involved. In MEDEA, a range of alternative mechanisms of damage are defined and described, and the symptoms of each mechanism which can be recognised by the assessor are identified and linked to the related causative mechanisms. By using MEDEA, the assessor is guided by the experience of experts in the identification of the damage states and also of the separate mechanisms involved. This leads to a better safety assessment, a more homogeneous evaluation of damage across the affected area, and a great enhancement in the value of the damage statistics obtained in the assessment. The method is applied to both masonry and reinforced concrete buildings of the forms widespread in Italy and neighbouring countries. The paper will describe MEDEA and the context for which it was designed; and will present an example of its use in the M5.1 Molise earthquake of 31.10.02 in which 27 people died and which caused damage to hundreds of buildings.

Damage identification in beams using speckle shearography and an optimal spatial sampling

NASA Astrophysics Data System (ADS)

Mininni, M.; Gabriele, S.; Lopes, H.; Araújo dos Santos, J. V.

2016-10-01

Over the years, the derivatives of modal displacement and rotation fields have been used to localize damage in beams. Usually, the derivatives are computed by applying finite differences. The finite differences propagate and amplify the errors that exist in real measurements, and thus, it is necessary to minimize this problem in order to get reliable damage localizations. A way to decrease the propagation and amplification of the errors is to select an optimal spatial sampling. This paper presents a technique where an optimal spatial sampling of modal rotation fields is computed and used to obtain the modal curvatures. Experimental measurements of modal rotation fields of a beam with single and multiple damages are obtained with shearography, which is an optical technique allowing the measurement of full-fields. These measurements are used to test the validity of the optimal sampling technique for the improvement of damage localization in real structures. An investigation on the ability of a model updating technique to quantify the damage is also reported. The model updating technique is defined by the variations of measured natural frequencies and measured modal rotations and aims at calibrating the values of the second moment of area in the damaged areas, which were previously localized.

Mailing microscope slides

USDA-ARS?s Scientific Manuscript database

Many insects feed agriculturally important crops, trees, and ornamental plants and cause millions of dollars of damage annually. Identification for some of these require the preparation of a microscope slide for examination. There are times when a microscope slide may need to be sent away to a speci...

Molecular and morphological identification of mealybug species (Hemiptera: Pseudococcidae) in Brazilian vineyards.

PubMed

Pacheco da Silva, Vitor C; Bertin, Aline; Blin, Aurélie; Germain, Jean-François; Bernardi, Daniel; Rignol, Guylène; Botton, Marcos; Malausa, Thibaut

2014-01-01

Mealybugs (Hemiptera: Pseudococcidae) are pests constraining the international trade of Brazilian table grapes. They damage grapes by transmitting viruses and toxins, causing defoliation, chlorosis, and vigor losses and favoring the development of sooty mold. Difficulties in mealybug identification remain an obstacle to the adequate management of these pests. In this study, our primary aim was to identify the principal mealybug species infesting the major table grape-producing regions in Brazil, by morphological and molecular characterization. Our secondary aim was to develop a rapid identification kit based on species-specific Polymerase Chain Reactions, to facilitate the routine identification of the most common pest species. We surveyed 40 sites infested with mealybugs and identified 17 species: Dysmicoccus brevipes (Cockerell), Dysmicoccus sylvarum Williams and Granara de Willink, Dysmicoccus texensis (Tinsley), Ferrisia cristinae Kaydan and Gullan, Ferrisia meridionalis Williams, Ferrisia terani Williams and Granara de Willink, Phenacoccus baccharidis Williams, Phenacoccus parvus Morrison, Phenacoccus solenopsis Tinsley, Planococcus citri (Risso), Pseudococcus viburni (Signoret), Pseudococcus cryptus Hempel, four taxa closely related each of to Pseudococcus viburni, Pseudococcus sociabilis Hambleton, Pseudococcus maritimus (Ehrhorn) and Pseudococcus meridionalis Prado, and one specimen from the genus Pseudococcus Westwood. The PCR method developed effectively identified five mealybug species of economic interest on grape in Brazil: D. brevipes, Pl. citri, Ps. viburni, Ph. solenopsis and Planococcus ficus (Signoret). Nevertheless, it is not possible to assure that this procedure is reliable for taxa that have not been sampled already and might be very closely related to the target species.

Molecular and Morphological Identification of Mealybug Species (Hemiptera: Pseudococcidae) in Brazilian Vineyards

PubMed Central

Pacheco da Silva, Vitor C.; Bertin, Aline; Blin, Aurélie; Germain, Jean-François; Bernardi, Daniel; Rignol, Guylène; Botton, Marcos; Malausa, Thibaut

2014-01-01

Mealybugs (Hemiptera: Pseudococcidae) are pests constraining the international trade of Brazilian table grapes. They damage grapes by transmitting viruses and toxins, causing defoliation, chlorosis, and vigor losses and favoring the development of sooty mold. Difficulties in mealybug identification remain an obstacle to the adequate management of these pests. In this study, our primary aim was to identify the principal mealybug species infesting the major table grape-producing regions in Brazil, by morphological and molecular characterization. Our secondary aim was to develop a rapid identification kit based on species-specific Polymerase Chain Reactions, to facilitate the routine identification of the most common pest species. We surveyed 40 sites infested with mealybugs and identified 17 species: Dysmicoccus brevipes (Cockerell), Dysmicoccus sylvarum Williams and Granara de Willink, Dysmicoccus texensis (Tinsley), Ferrisia cristinae Kaydan and Gullan, Ferrisia meridionalis Williams, Ferrisia terani Williams and Granara de Willink, Phenacoccus baccharidis Williams, Phenacoccus parvus Morrison, Phenacoccus solenopsis Tinsley, Planococcus citri (Risso), Pseudococcus viburni (Signoret), Pseudococcus cryptus Hempel, four taxa closely related each of to Pseudococcus viburni, Pseudococcus sociabilis Hambleton, Pseudococcus maritimus (Ehrhorn) and Pseudococcus meridionalis Prado, and one specimen from the genus Pseudococcus Westwood. The PCR method developed effectively identified five mealybug species of economic interest on grape in Brazil: D. brevipes, Pl. citri, Ps. viburni, Ph. solenopsis and Planococcus ficus (Signoret). Nevertheless, it is not possible to assure that this procedure is reliable for taxa that have not been sampled already and might be very closely related to the target species. PMID:25062012

Data mining framework for identification of myocardial infarction stages in ultrasound: A hybrid feature extraction paradigm (PART 2).

PubMed

Sudarshan, Vidya K; Acharya, U Rajendra; Ng, E Y K; Tan, Ru San; Chou, Siaw Meng; Ghista, Dhanjoo N

2016-04-01

Early expansion of infarcted zone after Acute Myocardial Infarction (AMI) has serious short and long-term consequences and contributes to increased mortality. Thus, identification of moderate and severe phases of AMI before leading to other catastrophic post-MI medical condition is most important for aggressive treatment and management. Advanced image processing techniques together with robust classifier using two-dimensional (2D) echocardiograms may aid for automated classification of the extent of infarcted myocardium. Therefore, this paper proposes novel algorithms namely Curvelet Transform (CT) and Local Configuration Pattern (LCP) for an automated detection of normal, moderately infarcted and severely infarcted myocardium using 2D echocardiograms. The methodology extracts the LCP features from CT coefficients of echocardiograms. The obtained features are subjected to Marginal Fisher Analysis (MFA) dimensionality reduction technique followed by fuzzy entropy based ranking method. Different classifiers are used to differentiate ranked features into three classes normal, moderate and severely infarcted based on the extent of damage to myocardium. The developed algorithm has achieved an accuracy of 98.99%, sensitivity of 98.48% and specificity of 100% for Support Vector Machine (SVM) classifier using only six features. Furthermore, we have developed an integrated index called Myocardial Infarction Risk Index (MIRI) to detect the normal, moderately and severely infarcted myocardium using a single number. The proposed system may aid the clinicians in faster identification and quantification of the extent of infarcted myocardium using 2D echocardiogram. This system may also aid in identifying the person at risk of developing heart failure based on the extent of infarcted myocardium. Copyright © 2016 Elsevier Ltd. All rights reserved.

TRAIP promotes DNA damage response during genome replication and is mutated in primordial dwarfism.

PubMed

Harley, Margaret E; Murina, Olga; Leitch, Andrea; Higgs, Martin R; Bicknell, Louise S; Yigit, Gökhan; Blackford, Andrew N; Zlatanou, Anastasia; Mackenzie, Karen J; Reddy, Kaalak; Halachev, Mihail; McGlasson, Sarah; Reijns, Martin A M; Fluteau, Adeline; Martin, Carol-Anne; Sabbioneda, Simone; Elcioglu, Nursel H; Altmüller, Janine; Thiele, Holger; Greenhalgh, Lynn; Chessa, Luciana; Maghnie, Mohamad; Salim, Mahmoud; Bober, Michael B; Nürnberg, Peter; Jackson, Stephen P; Hurles, Matthew E; Wollnik, Bernd; Stewart, Grant S; Jackson, Andrew P

2016-01-01

DNA lesions encountered by replicative polymerases threaten genome stability and cell cycle progression. Here we report the identification of mutations in TRAIP, encoding an E3 RING ubiquitin ligase, in patients with microcephalic primordial dwarfism. We establish that TRAIP relocalizes to sites of DNA damage, where it is required for optimal phosphorylation of H2AX and RPA2 during S-phase in response to ultraviolet (UV) irradiation, as well as fork progression through UV-induced DNA lesions. TRAIP is necessary for efficient cell cycle progression and mutations in TRAIP therefore limit cellular proliferation, providing a potential mechanism for microcephaly and dwarfism phenotypes. Human genetics thus identifies TRAIP as a component of the DNA damage response to replication-blocking DNA lesions.

[Ubiquitin-proteasome system and sperm DNA repair: An update].

PubMed

Zhang, Guo-Wei; Cai, Hong-Cai; Shang, Xue-Jun

2016-09-01

The ubiquitin-proteasome system (UPS) is a proteasome system widely present in the human body, which is composed of ubiquitin (Ub), ubiquitin activating enzymes (E1), ubiquitin conjugating enzymes (E2), ubiquitin protein ligases (E3), 26S proteasome, and deubiquitinating enzymes (DUBs) and involved in cell cycle regulation, immune response, signal transduction, DNA repair as well as protein degradation. Sperm DNA is vulnerable to interference or damage in the progression of chromosome association and homologous recombination. Recent studies show that UPS participates in DNA repair in spermatogenesis by modulating DNA repair enzymes via ubiquitination, assisting in the identification of DNA damage sites, raising damage repair-related proteins, initiating the DNA repair pathway, maintaining chromosome stability, and ensuring the normal process of spermatogenesis.

Analyzing the dynamic response of rotating blades in small-scale wind turbines

NASA Astrophysics Data System (ADS)

Hsiung, Wan-Ying; Huang, Yu-Ting; Loh, Chin-Hsiung; Loh, Kenneth J.; Kamisky, Robert J.; Nip, Danny; van Dam, Cornelis

2014-03-01

The objective of this study was to validate modal analysis, system identification and damage detection of small-scale rotating wind turbine blades in the laboratory and in the field. Here, wind turbine blades were instrumented with accelerometers and strain gages, and data acquisition was achieved using a prototype wireless sensing system. In the first portion of this study conducted in the laboratory, sensors were installed onto metallic structural elements that were fabricated to be representative of an actual wind blade. In order to control the excitation (rotation of the wind blade), a motor was used to spin the blades at controlled angular velocities. The wind turbine was installed on a shaking table for testing under rotation of turbine blades. Data measured by the sensors were recorded while the blade was operated at different speeds. On the other hand, the second part of this study utilized a small-scale wind turbine system mounted on the rooftop of a building. The main difference, as compared to the lab tests, was that the field tests relied on actual wind excitations (as opposed to a controlled motor). The raw data from both tests were analyzed using signal processing and system identification techniques for deriving the model response of the blades. The multivariate singular spectrum analysis (MSSA) and covariance-driven stochastic subspace identification method (SSI-COV) were used to identify the dynamic characteristics of the system. Damage of one turbine blade (loose bolts connection) in the lab test was also conducted. The extracted modal properties for both undamaged and damage cases under different ambient or forced excitations (earthquake loading) were compared. These tests confirmed that dynamic characterization of rotating wind turbines was feasible, and the results will guide future monitoring studies planned for larger-scale systems.

Dual-Polarimetric Radar-Based Tornado Debris Signatures and Paths Associated with Tornadoes Over Northern Alabama During the Historic Outbreak of 27 April 2011

NASA Technical Reports Server (NTRS)

Carey, Lawrence D.; Schultz, Christopher J.; Schultz, Elise V.; Petersen, Walter A.; Gatlin, Patrick N.; Knupp, Kevin R.; Molthan, Andrew L.; Jedloved, Gary J.; Carcione, Brian C.; Darden, Christopher B.;

Biological Sexing of a 4000-Year-Old Egyptian Mummy Head to Assess the Potential of Nuclear DNA Recovery from the Most Damaged and Limited Forensic Specimens

PubMed Central

Loreille, Odile; Ratnayake, Shashikala; Stockwell, Timothy B.; Mallick, Swapan; Skoglund, Pontus; Onorato, Anthony J.; Bergman, Nicholas H.; Reich, David; Irwin, Jodi A.

2018-01-01

High throughput sequencing (HTS) has been used for a number of years in the field of paleogenomics to facilitate the recovery of small DNA fragments from ancient specimens. Recently, these techniques have also been applied in forensics, where they have been used for the recovery of mitochondrial DNA sequences from samples where traditional PCR-based assays fail because of the very short length of endogenous DNA molecules. Here, we describe the biological sexing of a ~4000-year-old Egyptian mummy using shotgun sequencing and two established methods of biological sex determination (RX and RY), by way of mitochondrial genome analysis as a means of sequence data authentication. This particular case of historical interest increases the potential utility of HTS techniques for forensic purposes by demonstrating that data from the more discriminatory nuclear genome can be recovered from the most damaged specimens, even in cases where mitochondrial DNA cannot be recovered with current PCR-based forensic technologies. Although additional work remains to be done before nuclear DNA recovered via these methods can be used routinely in operational casework for individual identification purposes, these results indicate substantial promise for the retrieval of probative individually identifying DNA data from the most limited and degraded forensic specimens. PMID:29494531

Laser effects based optimal laser parameter identifications for paint removal from metal substrate at 1064 nm: a multi-pulse model

NASA Astrophysics Data System (ADS)

Han, Jinghua; Cui, Xudong; Wang, Sha; Feng, Guoying; Deng, Guoliang; Hu, Ruifeng

2017-10-01

Paint removal by laser ablation is favoured among cleaning techniques due to its high efficiency. How to predict the optimal laser parameters without producing damage to substrate still remains challenging for accurate paint stripping. On the basis of ablation morphologies and combining experiments with numerical modelling, the underlying mechanisms and the optimal conditions for paint removal by laser ablation are thoroughly investigated. Our studies suggest that laser paint removal is dominated by the laser vaporization effect, thermal stress effect and laser plasma effect, in which thermal stress effect is the most favoured while laser plasma effect should be avoided during removal operations. Based on the thermodynamic equations, we numerically evaluated the spatial distribution of the temperature as well as thermal stress in the paint and substrate under the irradiation of laser pulse at 1064 nm. The obtained curves of the paint thickness vs. threshold fluences can provide the reference standard of laser parameter selection in view of the paint layer with different thickness. A multi-pulse model is proposed and validated under a constant laser fluence to perfectly remove a thicker paint layer. The investigations and the methods proposed here might give hints to the efficient operations on the paint removal and lowering the risk of substrate damages.

Mitigation of formalin-induced RNA damage to advance whole transcriptomic analyses of archival tissues

EPA Science Inventory

Leveraging the use of biorepository samples for genomic analyses holds huge implications for human health, including applications in pathway identification, biomarker discovery, and tumor profiling for precision medicine. However, there is a need for better ways to reduce nucleic...

Live-cell Imaging Approaches for the Investigation of Xenobiotic-Induced Oxidant Stress

EPA Science Inventory

BACKGROUND: Oxidant stress is arguably a universal feature in toxicology. Research studies on the role of oxidant stress induced by xenobiotic exposures have typically relied on the identification of damaged biomolecules using a variety of conventional biochemical and molecular t...

Insect Pests of Field Crops. MP-28.

ERIC Educational Resources Information Center

Burkhardt, Chris C.

This document addresses the principles of field crop insect control through biological, mechanical, and chemical processes. Identification, life history, damage, pesticides, pesticide use and environmental considerations are presented for the major pests of corn, alfalfa, beans, small grains, sugar beets, and potatoes. Each section is accompanied…

Reassembly of Point Pleasant Bridge : documentation of structural damage and identification of laboratory specimens

DOT National Transportation Integrated Search

1970-07-01

The collapse of the Point Pleasant Bridge created many unique problems and posed many new questions to the bridge engineering profession. One question that was paramount was, "What caused the bridge to collapse?". Arrangements were made with the Corp...

Identification of a nucleopolyhedrovirus in winter moth populations from Massachusetts

Treesearch

John P. Burand; Anna Welch; Woojin Kim; Vince D' Amico; Joseph S. Elkinton

2011-01-01

The winter moth, Operophtera brumata, originally from Europe, has recently invaded eastern Massachusetts. This insect has caused widespread defoliation of many deciduous tree species and severely damaged a variety of crop plants in the infested area including apple, strawberry, and especially blueberry.

Hand gestures support word learning in patients with hippocampal amnesia.

PubMed

Hilverman, Caitlin; Cook, Susan Wagner; Duff, Melissa C

2018-06-01

Co-speech hand gesture facilitates learning and memory, yet the cognitive and neural mechanisms supporting this remain unclear. One possibility is that motor information in gesture may engage procedural memory representations. Alternatively, iconic information from gesture may contribute to declarative memory representations mediated by the hippocampus. To investigate these alternatives, we examined gesture's effects on word learning in patients with hippocampal damage and declarative memory impairment, with intact procedural memory, and in healthy and in brain-damaged comparison groups. Participants learned novel label-object pairings while producing gesture, observing gesture, or observing without gesture. After a delay, recall and object identification were assessed. Unsurprisingly, amnesic patients were unable to recall the labels at test. However, they correctly identified objects at above chance levels, but only if they produced a gesture at encoding. Comparison groups performed well above chance at both recall and object identification regardless of gesture. These findings suggest that gesture production may support word learning by engaging nondeclarative (procedural) memory. © 2018 Wiley Periodicals, Inc.

[The identification investigation of the material evidence of biological origin after multifactorial exposure].

PubMed

Iakovlev, D Iu; Solodun, Iu V; Proskurin, V N

1999-01-01

The possibility of investigating pieces of material evidence of biological origin after exposure to various factors is evaluated. The possibility of detecting proteins of liquid media of human organism by electrophoresis in polyacrylamide denatured gel is investigated. The method is intended for identification of biological material in a state of grave destruction. Methodology of such studies is proposed. The data indicate that the structural integrity and qualitative composition of the spectrum of main serum proteins are retained after combined exposure to damaging factors and complete destruction of blood cells.

Experimental and operational modal analysis of a laboratory scale model of a tripod support structure.

NASA Astrophysics Data System (ADS)

Luczak, M. M.; Mucchi, E.; Telega, J.

2016-09-01

The goal of the research is to develop a vibration-based procedure for the identification of structural failures in a laboratory scale model of a tripod supporting structure of an offshore wind turbine. In particular, this paper presents an experimental campaign on the scale model tested in two stages. Stage one encompassed the model tripod structure tested in air. The second stage was done in water. The tripod model structure allows to investigate the propagation of a circumferential representative crack of a cylindrical upper brace. The in-water test configuration included the tower with three bladed rotor. The response of the structure to the different waves loads were measured with accelerometers. Experimental and operational modal analysis was applied to identify the dynamic properties of the investigated scale model for intact and damaged state with different excitations and wave patterns. A comprehensive test matrix allows to assess the differences in estimated modal parameters due to damage or as potentially introduced by nonlinear structural response. The presented technique proves to be effective for detecting and assessing the presence of representative cracks.

Integrated Neural Flight and Propulsion Control System

NASA Technical Reports Server (NTRS)

Kaneshige, John; Gundy-Burlet, Karen; Norvig, Peter (Technical Monitor)

2001-01-01

This paper describes an integrated neural flight and propulsion control system. which uses a neural network based approach for applying alternate sources of control power in the presence of damage or failures. Under normal operating conditions, the system utilizes conventional flight control surfaces. Neural networks are used to provide consistent handling qualities across flight conditions and for different aircraft configurations. Under damage or failure conditions, the system may utilize unconventional flight control surface allocations, along with integrated propulsion control, when additional control power is necessary for achieving desired flight control performance. In this case, neural networks are used to adapt to changes in aircraft dynamics and control allocation schemes. Of significant importance here is the fact that this system can operate without emergency or backup flight control mode operations. An additional advantage is that this system can utilize, but does not require, fault detection and isolation information or explicit parameter identification. Piloted simulation studies were performed on a commercial transport aircraft simulator. Subjects included both NASA test pilots and commercial airline crews. Results demonstrate the potential for improving handing qualities and significantly increasing survivability rates under various simulated failure conditions.

Hereditary breast cancer and the BRCA1-associated FANCJ/BACH1/BRIP1

PubMed Central

Cantor, Sharon B; Guillemette, Shawna

2011-01-01

It is clear that FANCJ, also known as BACH1 or BRIP1, is an essential tumor suppressor gene based on the identification of clinically relevant mutations not only in breast cancer, but also the childhood cancer syndrome, Fanconi anemia. This conclusion is further supported by the direct and functional interaction between FANCJ and the hereditary breast cancer-associated gene product BRCA1. In the absence of the FANCJ DNA helicase or its interaction with BRCA1, cells have defects in several aspects of the DNA damage response. In particular, the BRCA1–FANCJ interaction is essential for promoting error-free repair, checkpoint control and for limiting DNA damage tolerance. As the number of FANCJ clinical mutations and affected patients accumulate, it will be critical to understand whether the associated tumors resemble BRCA-associated tumors. If so, FANCJ patients could also benefit from new therapies that selectively sensitize DNA repair-defective tumors and spare healthy cells. In this article, we summarize the breast cancer-associated FANCJ mutations and discuss functional outcomes for DNA repair and tumor suppression. PMID:21345144

Identification of Forensically Important Calliphoridae and Sarcophagidae Species Collected in Korea Using SNaPshot Multiplex System Targeting the Cytochrome c Oxidase Subunit I Gene

PubMed Central

Park, Ji Hye

2018-01-01

Estimation of postmortem interval (PMI) is paramount in modern forensic investigation. After the disappearance of the early postmortem phenomena conventionally used to estimate PMI, entomologic evidence provides important indicators for PMI estimation. The age of the oldest fly larvae or pupae can be estimated to pinpoint the time of oviposition, which is considered the minimum PMI (PMImin). The development rate of insects is usually temperature dependent and species specific. Therefore, species identification is mandatory for PMImin estimation using entomological evidence. The classical morphological identification method cannot be applied when specimens are damaged or have not yet matured. To overcome this limitation, some investigators employ molecular identification using mitochondrial cytochrome c oxidase subunit I (COI) nucleotide sequences. The molecular identification method commonly uses Sanger's nucleotide sequencing and molecular phylogeny, which are complex and time consuming and constitute another obstacle for forensic investigators. In this study, instead of using conventional Sanger's nucleotide sequencing, single-nucleotide polymorphisms (SNPs) in the COI gene region, which are unique between fly species, were selected and targeted for single-base extension (SBE) technology. These SNPs were genotyped using a SNaPshot® kit. Eleven Calliphoridae and seven Sarcophagidae species were covered. To validate this genotyping, fly DNA samples (103 adults, 84 larvae, and 4 pupae) previously confirmed by DNA barcoding were used. This method worked quickly with minimal DNA, providing a potential alternative to conventional DNA barcoding. Consisting of only a few simple electropherogram peaks, the results were more straightforward compared with those of the conventional DNA barcoding produced by Sanger's nucleotide sequencing. PMID:29682531

Identification, prediction, and mitigation of sinkhole hazards in evaporite karst areas

USGS Publications Warehouse

Gutierrez, F.; Cooper, A.H.; Johnson, K.S.

2008-01-01

Sinkholes usually have a higher probability of occurrence and a greater genetic diversity in evaporite terrains than in carbonate karst areas. This is because evaporites have a higher solubility and, commonly, a lower mechanical strength. Subsidence damage resulting from evaporite dissolution generates substantial losses throughout the world, but the causes are only well understood in a few areas. To deal with these hazards, a phased approach is needed for sinkhole identification, investigation, prediction, and mitigation. Identification techniques include field surveys and geomorphological mapping combined with accounts from local people and historical sources. Detailed sinkhole maps can be constructed from sequential historical maps, recent topographical maps, and digital elevation models (DEMs) complemented with building-damage surveying, remote sensing, and high-resolution geodetic surveys. On a more detailed level, information from exposed paleosubsidence features (paleokarst), speleological explorations, geophysical investigations, trenching, dating techniques, and boreholes may help in investigating dissolution and subsidence features. Information on the hydrogeological pathways including caves, springs, and swallow holes are particularly important especially when corroborated by tracer tests. These diverse data sources make a valuable database-the karst inventory. From this dataset, sinkhole susceptibility zonations (relative probability) may be produced based on the spatial distribution of the features and good knowledge of the local geology. Sinkhole distribution can be investigated by spatial distribution analysis techniques including studies of preferential elongation, alignment, and nearest neighbor analysis. More objective susceptibility models may be obtained by analyzing the statistical relationships between the known sinkholes and the conditioning factors. Chronological information on sinkhole formation is required to estimate the probability of occurrence of sinkholes (number of sinkholes/km2 year). Such spatial and temporal predictions, frequently derived from limited records and based on the assumption that past sinkhole activity may be extrapolated to the future, are non-corroborated hypotheses. Validation methods allow us to assess the predictive capability of the susceptibility maps and to transform them into probability maps. Avoiding the most hazardous areas by preventive planning is the safest strategy for development in sinkhole-prone areas. Corrective measures could be applied to reduce the dissolution activity and subsidence processes. A more practical solution for safe development is to reduce the vulnerability of the structures by using subsidence-proof designs. ?? 2007 Springer-Verlag.

Impedance Based Detection of Delamination in Composite Structures

NASA Astrophysics Data System (ADS)

Djemana, M.; Hrairi, M.

2017-03-01

Nowadays commercial and military aircrafts are increasingly using composite materials to take advantage of their excellent specific strength and stiffness properties but impacts on composites due to bird-strike, hail-storm cause barely visible impact damage (BVID) that underscores the need for robust structural health monitoring methods. Hence, damage identification in composite materials is a widely researched area that has to deal with problems coming from the anisotropic nature of composites and the fact that much of the damage occurs beneath the top surface of the laminate. This paper focuses on understanding self-sensing piezoelectric wafer active sensors (PWAS) to conduct electromechanical impedance (EMI) in glass fibre reinforced polymer composite to perform structural health monitoring. With the aid of a 3D ANSYS finite element model, an analysis of different techniques for the detection of position and size of a delamination in a composite structure using piezoelectric patches had been performed. The real part of the impedance is used because it is known to be more reactive to damage or changes in the structure’s integrity and less sensitive to ambient temperature changes compared to the imaginary part. Comparison with experimental results is presented to validate the FE results. The experimental setup utilizes as its main apparatus an impedance analyser HP4194 that reads the in-situ EMI of PWAS bonded to the monitored composite structure. A good match between experimental and numerical results has been observed for low and high frequencies. The analysis in this paper provides necessary basis for delamination detection in composite structures using EMI technique

Distribution and diversity of Russian wheat aphid (Hemiptera: Aphididae) biotypes in South Africa and Lesotho.

PubMed

Jankielsohn, Astrid

2011-10-01

Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Hemiptera: Aphididae) was recorded for the first time in South Africa in 1978. In 2005, a second biotype, RWASA2, emerged, and here we report on the emergence of yet another biotype, found for the first time in 2009. The discovery of new Russian wheat aphid biotypes is a significant challenge to the wheat, Triticum aestivum L., industry in South Africa. Russian wheat aphid resistance in wheat, that offered wheat producers a long-term solution to Russian wheat aphid control, may no longer be effective in areas where the new biotypes occur. It is therefore critical to determine the diversity and extent of distribution of biotypes in South Africa to successfully deploy Russian wheat aphid resistance in wheat. Screening of 96 Russian wheat aphid clones resulted in identification of three Russian wheat aphid biotypes. Infestations of RWASA1 caused susceptible damage symptoms only in wheat entries containing the Dn3 gene. Infestations of RWASA2 caused susceptible damage symptoms in wheat entries containing Dn1, Dn2, Dn3, and Dn9 resistant genes. Based on the damage-rating scores for the seven resistance sources, a new biotype, which caused damage rating scores different from those for RWASA1 and RWASA2, was evident among the Russian wheat aphid populations tested. This new biotype is virulent to the same resistance sources as RWASA2 (Dn1, Dn2, Dn3, and Dn9), but it also has added virulence to Dn4, whereas RWASA2 is avirulent to this resistance source.

Selected Flight Test Results for Online Learning Neural Network-Based Flight Control System

NASA Technical Reports Server (NTRS)

Williams, Peggy S.

2004-01-01

The NASA F-15 Intelligent Flight Control System project team has developed a series of flight control concepts designed to demonstrate the benefits of a neural network-based adaptive controller. The objective of the team is to develop and flight-test control systems that use neural network technology to optimize the performance of the aircraft under nominal conditions as well as stabilize the aircraft under failure conditions. Failure conditions include locked or failed control surfaces as well as unforeseen damage that might occur to the aircraft in flight. This report presents flight-test results for an adaptive controller using stability and control derivative values from an online learning neural network. A dynamic cell structure neural network is used in conjunction with a real-time parameter identification algorithm to estimate aerodynamic stability and control derivative increments to the baseline aerodynamic derivatives in flight. This set of open-loop flight tests was performed in preparation for a future phase of flights in which the learning neural network and parameter identification algorithm output would provide the flight controller with aerodynamic stability and control derivative updates in near real time. Two flight maneuvers are analyzed a pitch frequency sweep and an automated flight-test maneuver designed to optimally excite the parameter identification algorithm in all axes. Frequency responses generated from flight data are compared to those obtained from nonlinear simulation runs. An examination of flight data shows that addition of the flight-identified aerodynamic derivative increments into the simulation improved the pitch handling qualities of the aircraft.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mittermayr, Florian, E-mail: f.mittermayr@tugraz.at; Baldermann, Andre; Kurta, Christoph

Understanding the mechanisms leading to chemical attack on concrete is crucial in order to prevent damage of concrete structures. To date, most studies on sulfate attack and thaumasite formation are based on empirical approaches, as the identification of associated reaction mechanisms and paths is known to be highly complex. In this study, sulfate damaged concrete from Austrian tunnels was investigated by mineralogical, chemical and isotope methods to identify the reactions which caused intense concrete alteration. Major, minor and trace elemental contents as well as isotope ratios of local ground water (GW), drainage water (DW) and interstitial solutions (IS), extracted frommore » damaged concrete material, were analyzed. Locally occurring GW contained 3 to 545 mg L{sup −1} of SO{sub 4} and is thus regarded as slightly aggressive to concrete in accordance to standard specifications (e.g. DIN EN 206-1). The concrete linings and drainage systems of the studied tunnels, however, have partly suffered from intensive sulfate attack. Heavily damaged concrete consisted mainly of thaumasite, secondary calcite, gypsum, and relicts of aggregates. Surprisingly, the concentrations of dissolved ions were extremely enriched in the IS with up to 30,000 and 12,000 mg L{sup −1} of SO{sub 4} and Cl, respectively. Analyses of aqueous ions with a highly conservative behavior, e.g. K, Rb and Li, as well as {sup 2}H/H and {sup 18}O/{sup 16}O isotope ratios of H{sub 2}O of the IS showed an intensive accumulation of ions and discrimination of the light isotopes vs. the GW. These isotope signals of the IS clearly revealed evaporation at distinct relative humidities. From ion accumulation and isotope fractionation individual total and current evaporation degrees were estimated. Our combined elemental and isotopic approach verified wetting–drying cycles within a highly dynamic concrete-solution-atmosphere system. Based on these boundary conditions, key factors controlling thaumasite formation are discussed regarding the development of more sulfate-resistant concrete and concrete structures.« less

Statewide traffic safety study phase II : identification of major traffic safety problem areas in Louisiana [tech summary].

DOT National Transportation Integrated Search

2012-04-01

Louisianas crash rate is consistently among the highest in the nation, and it imposes signifi cant economic and social : costs on the state. Property damage, lost productivity, medical expenses, and infl ated motor vehicle insurance rates : impose...

Identification of grape cultivars and rootstocks with resistance to vine mealybug

USDA-ARS?s Scientific Manuscript database

Vine mealybug, an insect pest capable of causing direct and indirect damage to grape vineyards, costs California growers millions of dollars annually. Insecticide sprays used to manage the pest provide inconsistent results, and sustainable methods of control are needed. A previous study identified a...

Root parasites of southern forests

Treesearch

Lytton J. Musselman; William F. Mann

1978-01-01

The five families of root parasites of the South are discussed relative to selection of hosts, ecology, and potential for damage to commercial species. An identification key to all genera of root parasites is included. Plants and flowers of 29 species are illustrated and their distribution in the South mapped.

College Sports' L-Word.

ERIC Educational Resources Information Center

Blum, Debra E.

1994-01-01

Women in college athletics are finding that homophobia is widespread and that identification as a lesbian can damage their careers. It is common practice to label a coach a lesbian either to minimize complaints about sex discrimination in program funding or to draw prospective athletes away from her program. (MSE)

The Family's Role in Rehabilitation: "Early Warning System."

ERIC Educational Resources Information Center

Westin, Marijo Thomas; Reiss, David

1979-01-01

Describes methods used in a project at George Washington University's Rehabilitation Research and Training Center to predict and classify a family's involvement in a patient's rehabilitation program. As family attitudes can enhance or damage a program's effectiveness, early identification of uncooperative families is necessary so that intervention…

The use of advanced mass spectrometry to dissect the life-cycle of photosystem II

DOE PAGES

Weisz, Daniel A.; Gross, Michael L.; Pakrasi, Himadri B.

2016-05-10

Photosystem II (PSII) is a photosynthetic membrane-protein complex that undergoes an intricate, tightly regulated cycle of assembly, damage, and repair. The available crystal structures of cyanobacterial PSII are an essential foundation for understanding PSII function, but nonetheless provide a snapshot only of the active complex. To study aspects of the entire PSII life-cycle, mass spectrometry (MS) has emerged as a powerful tool that can be used in conjunction with biochemical techniques. In this article, we present the MS-based approaches that are used to study PSII composition, dynamics, and structure, and review the information about the PSII life-cycle that has beenmore » gained by these methods. This information includes the composition of PSII subcomplexes, discovery of accessory PSII proteins, identification of post-translational modifications and quantification of their changes under various conditions, determination of the binding site of proteins not observed in PSII crystal structures, conformational changes that underlie PSII functions, and identification of water and oxygen channels within PSII. Lastly, we conclude with an outlook for the opportunity of future MS contributions to PSII research.« less

Amyloidosis: Pathogenesis and New Therapeutic Options

PubMed Central

Merlini, Giampaolo; Seldin, David C.; Gertz, Morie A.

2011-01-01

The systemic amyloidoses are a group of complex diseases caused by tissue deposition of misfolded proteins that results in progressive organ damage. The most common type, immunoglobulin light chain amyloidosis (AL), is caused by clonal plasma cells that produce misfolded light chains. The purpose of this review is to provide up-to-date information on diagnosis and treatment options for AL amyloidosis. Early, accurate diagnosis is the key to effective therapy, and unequivocal identification of the amyloidogenic protein may require advanced technologies and expertise. Prognosis is dominated by the extent of cardiac involvement, and cardiac staging directs the choice of therapy. Treatment for AL amyloidosis is highly individualized, determined on the basis of age, organ dysfunction, and regimen toxicities, and should be guided by biomarkers of hematologic and cardiac response. Alkylator-based chemotherapy is effective in almost two thirds of patients. Novel agents are also active, and trials are ongoing to establish their optimal use. Treatment algorithms will continue to be refined through controlled trials. Advances in basic research have led to the identification of new drug targets and therapeutic approaches, which will be integrated with chemotherapy in the future. PMID:21483018

Chemotherapy Extravasation Management: 21-Year Experience.

PubMed

Onesti, Maria Giuseppina; Carella, Sara; Fioramonti, Paolo; Scuderi, Nicolò

2017-11-01

Chemotherapy extravasation may result in serious damage to patients, with irreversible local injures and disability. Evidence-based standardization on extravasation management is lacking and many institutions do not practice adequate procedures to prevent the severer damages. Our aim was to explore the prevention and treatment of extravasation injuries, proposing a standard therapeutic protocol together with a review of the literature. From January 1994 to December 2015, 545 cases were reviewed (age range, 5-87 years; 282 men and 263 women). Our therapeutic protocol consisted of local infiltration of saline solution and topical occlusive applications of corticosteroids. The infiltrations were administrated 3 to 6 times a week depending on damage severity. Our protocol allowed us to prevent ulceration in 373 cases. Only 27 patients required surgery (escarectomy, skin graft, regional, and free flap). Numerous treatments have been proposed in literature. The antidotes have been discussed controversially and are not considered standard methods for treatment, especially when polychemotherapy is administrated and the identification of the responsible drug is not possible. We proposed the use of saline solution injection to dilute rapidly the drug, thus reducing its local toxic effects. This method is easy to use and always reproducible even when the drug is not known or when it is administrated in combination with other drugs. It is possible to perform it in ambulatory regimen, and, overall, it represents a standard method.

Small vessel disease, neurovascular regulation and cognitive impairment: post-mortem studies reveal a complex relationship, still poorly understood.

PubMed

Love, Seth; Miners, J Scott

2017-07-15

The contribution of vascular disease to cognitive impairment is under-recognized and the pathogenesis is poorly understood. This information gap has multiple causes, including a lack of post-mortem validation of clinical diagnoses of vascular cognitive impairment (VCI) or vascular dementia (VaD), the exclusion of cases with concomitant neurodegenerative disease when diagnosing VCI/VaD, and a lack of standardization of neuropathological assessment protocols for vascular disease. Other contributors include a focus on end-stage destructive lesions to the exclusion of more subtle types of diffuse brain injury, on structural abnormalities of arteries and arterioles to the exclusion of non-structural abnormalities and capillary damage, and the use of post-mortem sampling strategies that are biased towards the identification of neurodegenerative pathologies. Recent studies have demonstrated the value of detailed neuropathology in characterizing vascular contributions to cognitive impairment (e.g. in diabetes), and highlight the importance of diffuse white matter changes, capillary damage and vasoregulatory abnormalities in VCI/VaD. The use of standardized, evidence-based post-mortem assessment protocols and the inclusion of biochemical as well as morphological methods in neuropathological studies should improve the accuracy of determination of the contribution of vascular disease to cognitive impairment and clarify the relative contribution of different pathogenic processes to the tissue damage. © 2017 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

Propogation loss with frequency of ultrasound guided waves in a composite metal-honeycomb structure

NASA Astrophysics Data System (ADS)

Saxena, Indu F.; Baid, Harsh K.; Guzman, Narciso; Kempen, Lothar U.; Mal, Ajit

2009-05-01

Non-destructive testing of critical structural components is time consuming, while necessary for maintaining safe operation. Large aerospace structures, such as the vertical stabilizers of aircraft undergo inspection at regular intervals for damage diagnostics. However, conventional techniques for damage detection and identification before repair can be scheduled are conducted off-line and therefore can take weeks. The use of guided ultrasound waves is being investigated to expedite damage detection in composites. We measure the frequency dependent loss of ultrasonic guided waves for a structure comprising a boron-nitride composite skin sandwiching an aluminum honeycomb. A wide range of ultrasound frequencies propagate as measured using PZTs, with the lowest attenuation observed about 200-250 kHz. These measurements are confirmed using optical fiber Bragg grating arrays used as ultrasound transducers.

TRAIP promotes DNA damage response during genome replication and is mutated in primordial dwarfism

PubMed Central

Leitch, Andrea; Higgs, Martin R.; Bicknell, Louise S.; Yigit, Gökhan; Blackford, Andrew N.; Zlatanou, Anastasia; Mackenzie, Karen J.; Reddy, Kaalak; Halachev, Mihail; McGlasson, Sarah; Reijns, Martin A. M.; Fluteau, Adeline; Martin, Carol-Anne; Sabbioneda, Simone; Elcioglu, Nursel H.; Altmüller, Janine; Thiele, Holger; Greenhalgh, Lynn; Chessa, Luciana; Maghnie, Mohamad; Salim, Mahmoud; Bober, Michael B.; Nürnberg, Peter; Jackson, Stephen P.; Hurles, Matthew E.; Wollnik, Bernd; Stewart, Grant S.; Jackson, Andrew P.

2015-01-01

DNA lesions encountered by replicative polymerases threaten genome stability and cell cycle progression. Here we report the identification of mutations in TRAIP, encoding an E3 RING ubiquitin ligase, in patients with microcephalic primordial dwarfism/Seckel syndrome. We establish that TRAIP relocalizes to sites of DNA damage where it is required for optimal phosphorylation of H2AX and RPA2 during S-phase in response to UV irradiation, as well as fork progression through UV-induced DNA lesions. TRAIP is necessary for efficient cell cycle progression and mutations in TRAIP therefore limit cellular proliferation, providing a potential mechanism for microcephaly and dwarfism phenotypes. Human genetics thus identifies TRAIP as a novel component of the DNA damage response to replication-blocking DNA lesions. PMID:26595769

Identification of genotoxic compounds in crude oil using fractionation according to distillation, polarity and Kow.

PubMed

Park, Shin Yeong; Lee, Hyo Jin; Khim, Jong Seong; Kim, Gi Beum

2017-01-30

We examined the degree of DNA damage caused by fractions of crude oil in accordance with the boiling points, polarity and log K ow . Relatively high DNA damage was observed in the aromatic fraction (290-330°C) and resin and polar fraction (350-400°C). The resin and polar fraction showed relatively high genotoxicity compared with the aliphatic and aromatic fraction at the 1-4 log K ow range. At the 6-7 log K ow range, the aromatic fraction showed relatively high DNA damage compared with the aliphatic and resin and polar fraction. In particular, every detailed fraction in accordance with the log K ow values (aliphatic and aromatic (310-320°C) and resins and polar fractions (370-380°C)) showed one or less than one DNA damage. However, the fractions before separation in accordance with log K ow values (aliphatic and aromatic (310-320°C) and resin and polar (370-380°C) fractions) showed high DNA damage. Thus, we confirm the synergistic action between the detailed compounds. Copyright © 2016 Elsevier Ltd. All rights reserved.

Protective role of humic acids against picloram-induced genomic instability and DNA methylation in Phaseolus vulgaris.

PubMed

Taspinar, Mahmut Sinan; Aydin, Murat; Sigmaz, Burcu; Yildirim, Nalan; Agar, Guleray

2017-10-01

Picloram (4-amino-3,5,6-trichloropicolinic acid) is a liquid auxinic herbicide used to control broad-leaved weeds. Picloram is representing a possible hazard to ecosystems and human health. Therefore, in this study, DNA methylation changes and DNA damage levels in Phaseolus vulgaris exposed to picloram, as well as whether humic acid (HA) has preventive effects on these changes were investigated. Random amplified polymorphic DNA (RAPD) techniques were used for identification of DNA damage and coupled restriction enzyme digestion-random amplification (CRED-RA) techniques were used to detect the changed pattern of DNA methylation. According to the obtained results, picloram (5, 10, 20, and 40 mg/l) caused DNA damage profile changes (RAPDs) increasing, DNA hypomethylation and genomic template stability (GTS) decreasing. On the other hand, different concentrations of applied HA (2, 4, 6, 8, and 10%) reduced hazardous effects of picloram. The results of the experiment have explicitly indicated that HAs could be an alternative for reducing genetic damage in plants. In addition to the alleviate effects of humic acid on genetic damage, its epigenetic effect is hypomethylation.

Recent advances in laser in situ keratomileusis-associated dry eye.

PubMed

Xie, Wenjia

2016-03-01

Dry eye is the most common complication after laser in situ keratomileusis (LASIK). The major cause of LASIK-associated dry eye is corneal nerve damage. Early identification and treatment of post-operative dry eye are essential to prevent further ocular surface damage. This article reviews the recent studies of LASIK-associated dry eye, including clinical features, aetiology, risk factors, evaluations and treatment. The applications of novel technologies in LASIK-associated dry eye evaluation like anterior segment spectral-domain optical coherence tomography (SD-OCT) and corneal confocal microscopy are also introduced in this review. © 2016 Optometry Australia.

Chimeric proteins for detection and quantitation of DNA mutations, DNA sequence variations, DNA damage and DNA mismatches

DOEpatents

McCutchen-Maloney, Sandra L.

2002-01-01

Chimeric proteins having both DNA mutation binding activity and nuclease activity are synthesized by recombinant technology. The proteins are of the general formula A-L-B and B-L-A where A is a peptide having DNA mutation binding activity, L is a linker and B is a peptide having nuclease activity. The chimeric proteins are useful for detection and identification of DNA sequence variations including DNA mutations (including DNA damage and mismatches) by binding to the DNA mutation and cutting the DNA once the DNA mutation is detected.

Automated crack detection in conductive smart-concrete structures using a resistor mesh model

NASA Astrophysics Data System (ADS)

Downey, Austin; D'Alessandro, Antonella; Ubertini, Filippo; Laflamme, Simon

2018-03-01

Various nondestructive evaluation techniques are currently used to automatically detect and monitor cracks in concrete infrastructure. However, these methods often lack the scalability and cost-effectiveness over large geometries. A solution is the use of self-sensing carbon-doped cementitious materials. These self-sensing materials are capable of providing a measurable change in electrical output that can be related to their damage state. Previous work by the authors showed that a resistor mesh model could be used to track damage in structural components fabricated from electrically conductive concrete, where damage was located through the identification of high resistance value resistors in a resistor mesh model. In this work, an automated damage detection strategy that works through placing high value resistors into the previously developed resistor mesh model using a sequential Monte Carlo method is introduced. Here, high value resistors are used to mimic the internal condition of damaged cementitious specimens. The proposed automated damage detection method is experimentally validated using a 500 × 500 × 50 mm3 reinforced cement paste plate doped with multi-walled carbon nanotubes exposed to 100 identical impact tests. Results demonstrate that the proposed Monte Carlo method is capable of detecting and localizing the most prominent damage in a structure, demonstrating that automated damage detection in smart-concrete structures is a promising strategy for real-time structural health monitoring of civil infrastructure.

Leveraging long sequencing reads to investigate R-gene clustering and variation in sugar beet

USDA-ARS?s Scientific Manuscript database

Host-pathogen interactions are of prime importance to modern agriculture. Plants utilize various types of resistance genes to mitigate pathogen damage. Identification of the specific gene responsible for a specific resistance can be difficult due to duplication and clustering within R-gene families....

Effect of topographic characteristics on compound topographic index for identification of gully channel initiation locations

USDA-ARS?s Scientific Manuscript database

Sediment loads from gully erosion can be a significant sediment source within watershed resulting in major contributions to water quality problems, reduction of crop productivity by removal of nutrient rich top soil, and damaging downstream ecosystems. Areas containing a high probability of forming ...

21 CFR 58.107 - Test and control article handling.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Test and control article handling. 58.107 Section 58.107 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL... designed to preclude the possibility of contamination, deterioration, or damage. (c) Proper identification...

33 CFR 214.9 - Requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... work. (2) To hold and save the United States free from damages in connection with the authorized work... in a manner satisfactory to the Chief of Engineers all installed work during the emergency. (4) To... water quality statements with the request, and the identification of the threat to public health and...

Ornamental, Shade Tree, and Turf Pest Control Manual.

ERIC Educational Resources Information Center

Bowman, James S.; And Others

This document provides the information needed to meet the standards for pesticide applicator certification. Section one deals with the identification of pests and the diagnosis of pest damage. Section two provides an introduction to weed characteristics and herbicide usage. The application, formulation, effects and safety of herbicides in general…

Environmental Quality of Upper Honey Creek: A Preliminary Assessment.

DTIC Science & Technology

1981-01-01

chironomid pupae and " Plecoptera ", which consisted of stoneflies that were too damaged for further identification. Adult and larval beetles were...11 bbei amie1 13 15 32 153 22 leopoda (mow bugs) Aselluet (forbeal) 12 3 oapoda (crayfish) ftocabue acutus acutug Plecoptera (stoneflies) 3 1 1

Identification of high-speed rail ballast flight risk factors and risk mitigation strategies - final report.

DOT National Transportation Integrated Search

2015-04-01

The phenomenon of flying ballast is well-documented in high-speed rail operations. Displaced ballast particles from the track bed : may cause damage to rolling stock as well as the track infrastructure, and wayside structures close to the right of wa...

Invertebrate communities in spring wheat and the identification of cereal aphid predators through molecular gut content analysis

USDA-ARS?s Scientific Manuscript database

Cereal aphid complexes are responsible for reducing wheat production worldwide; however, management against these species is rare in North America. Generalist predators may contribute to reducing cereal aphid numbers and preventing significant damage to crops. A two-year survey identifying the arth...

Calculation on spectrum of direct DNA damage induced by low-energy electrons including dissociative electron attachment.

PubMed

Liu, Wei; Tan, Zhenyu; Zhang, Liming; Champion, Christophe

2017-03-01

In this work, direct DNA damage induced by low-energy electrons (sub-keV) is simulated using a Monte Carlo method. The characteristics of the present simulation are to consider the new mechanism of DNA damage due to dissociative electron attachment (DEA) and to allow determining damage to specific bases (i.e., adenine, thymine, guanine, or cytosine). The electron track structure in liquid water is generated, based on the dielectric response model for describing electron inelastic scattering and on a free-parameter theoretical model and the NIST database for calculating electron elastic scattering. Ionization cross sections of DNA bases are used to generate base radicals, and available DEA cross sections of DNA components are applied for determining DNA-strand breaks and base damage induced by sub-ionization electrons. The electron elastic scattering from DNA components is simulated using cross sections from different theoretical calculations. The resulting yields of various strand breaks and base damage in cellular environment are given. Especially, the contributions of sub-ionization electrons to various strand breaks and base damage are quantitatively presented, and the correlation between complex clustered DNA damage and the corresponding damaged bases is explored. This work shows that the contribution of sub-ionization electrons to strand breaks is substantial, up to about 40-70%, and this contribution is mainly focused on single-strand break. In addition, the base damage induced by sub-ionization electrons contributes to about 20-40% of the total base damage, and there is an evident correlation between single-strand break and damaged base pair A-T.

An novel identification method of the environmental risk sources for surface water pollution accidents in chemical industrial parks.

PubMed

Peng, Jianfeng; Song, Yonghui; Yuan, Peng; Xiao, Shuhu; Han, Lu

2013-07-01

The chemical industry is a major source of various pollution accidents. Improving the management level of risk sources for pollution accidents has become an urgent demand for most industrialized countries. In pollution accidents, the released chemicals harm the receptors to some extent depending on their sensitivity or susceptibility. Therefore, identifying the potential risk sources from such a large number of chemical enterprises has become pressingly urgent. Based on the simulation of the whole accident process, a novel and expandable identification method for risk sources causing water pollution accidents is presented. The newly developed approach, by analyzing and stimulating the whole process of a pollution accident between sources and receptors, can be applied to identify risk sources, especially on the nationwide scale. Three major types of losses, such as social, economic and ecological losses, were normalized, analyzed and used for overall consequence modeling. A specific case study area, located in a chemical industry park (CIP) along the Yangtze River in Jiangsu Province, China, was selected to test the potential of the identification method. The results showed that there were four risk sources for pollution accidents in this CIP. Aniline leakage in the HS Chemical Plant would lead to the most serious impact on the surrounding water environment. This potential accident would severely damage the ecosystem up to 3.8 km downstream of Yangtze River, and lead to pollution over a distance stretching to 73.7 km downstream. The proposed method is easily extended to the nationwide identification of potential risk sources.

Colon Cancer-Upregulated Long Non-Coding RNA lincDUSP Regulates Cell Cycle Genes and Potentiates Resistance to Apoptosis.

PubMed

Forrest, Megan E; Saiakhova, Alina; Beard, Lydia; Buchner, David A; Scacheri, Peter C; LaFramboise, Thomas; Markowitz, Sanford; Khalil, Ahmad M

2018-05-09

Long non-coding RNAs (lncRNAs) are frequently dysregulated in many human cancers. We sought to identify candidate oncogenic lncRNAs in human colon tumors by utilizing RNA sequencing data from 22 colon tumors and 22 adjacent normal colon samples from The Cancer Genome Atlas (TCGA). The analysis led to the identification of ~200 differentially expressed lncRNAs. Validation in an independent cohort of normal colon and patient-derived colon cancer cell lines identified a novel lncRNA, lincDUSP, as a potential candidate oncogene. Knockdown of lincDUSP in patient-derived colon tumor cell lines resulted in significantly decreased cell proliferation and clonogenic potential, and increased susceptibility to apoptosis. The knockdown of lincDUSP affects the expression of ~800 genes, and NCI pathway analysis showed enrichment of DNA damage response and cell cycle control pathways. Further, identification of lincDUSP chromatin occupancy sites by ChIRP-Seq demonstrated association with genes involved in the replication-associated DNA damage response and cell cycle control. Consistent with these findings, lincDUSP knockdown in colon tumor cell lines increased both the accumulation of cells in early S-phase and γH2AX foci formation, indicating increased DNA damage response induction. Taken together, these results demonstrate a key role of lincDUSP in the regulation of important pathways in colon cancer.

A novel approach to increasing cocaine detection confidence utilizing ion mobility spectrometry

NASA Technical Reports Server (NTRS)

Jadamec, J. Richard; Su, Chih-Wu; Rigdon, Stephen; Norwood, Lavan

1995-01-01

When a positive detection of a narcotic occurs during the search of a vessel, a decision has to be made whether further intensive search is warranted. In terms of unwarranted delays of vessels and possible property damage, the accuracy of the analytical determination is very important. Analytical accuracy becomes critical when the data may be used in court actions as evidence. For this purpose, the U.S. Coast Guard has been investigating several confirmatory ion mobility spectrometry (IMS) field methods for the detection and identification of cocaine. This paper presents the findings of our investigations on the use of catalytic pyrolysis and base hydrolysis as confirmatory methods. The catalytic effects of various metals on the pyrolysis reaction are reported. In addition, the effects of several different ion mobility spectrometer sample transfer mediums and varying laboratory conditions on the base hydrolysis of the cocaine molecule are also be reported.

Epidemiological study on long-term effects of pesticides on human health*

PubMed Central

Paccagnella, B.; Ghezzo, F.; Prati, L.; Fedrazzoni, U.; Belloni, G.

1971-01-01

Two rural areas in Italy with different rates of pesticide usage were subjected to a cross-sectional investigation, based on the identification of organochlorine compounds in the environment and in human fatty tissues and on the determination of their concentration and a prospective investigation, based on the collection of data of past and present pathology and symptomatology from two stratified random groups of inhabitants of both areas. The cross-sectional investigation showed only small differences in environmental pollution and no differences in the storage of organochlorine compounds in fatty tissues in the two areas. The prospective investigation showed a higher prevalence of pathology and symptomatology in the population of the area where pesticides were used in larger quantities. Several haematochemical tests were used in an attempt to differentiate between populations at different levels of risk of toxic damage, but without success. PMID:5316616

Echodentography based on nonlinear time reversal tomography: Ultrasonic nonlinear signature identification

NASA Astrophysics Data System (ADS)

Santos, Serge Dos; Farova, Zuzana; Kus, Vaclav; Prevorovsky, Zdenek

2012-05-01

This paper examines possibilities of using Nonlinear Elastic Wave Spectroscopy (NEWS) methods in dental investigations. Themain task consisted in imaging cracks or other degradation signatures located in dentin close to the Enamel-Dentine Junction (EDJ). NEWS approach was investigated experimentally with a new bi-modal acousto-optic set-up based on the chirp-coded nonlinear ultrasonic time reversal (TR) concepts. Complex internal structure of the tooth is analyzed by the TR-NEWS procedure adapted to tomography-like imaging of the tooth damages. Ultrasonic instrumentation with 10 MHz bandwidth has been set together including laser vibrometer used to detect responses of the tooth on its excitation carried out by a contact piezoelectric transducer. Bi-modal TR-NEWS images of the tooth were created before and after focusing, which resulted from the time compression. The polar B-scan of the tooth realized with TR-NEWS procedure is suggested to be applied as a new echodentography imaging.

Development of ecological indicator guilds for land management

USGS Publications Warehouse

Krzysik, A.J.; Balbach, H.E.; Duda, J.J.; Emlen, J.M.; Freeman, D.C.; Graham, J.H.; Kovacic, D.A.; Smith, L.M.; Zak, J.C.

2005-01-01

Agency land-use must be efficiently and cost-effectively monitored to assess conditions and trends in ecosystem processes and natural resources relevant to mission requirements and legal mandates. Ecological Indicators represent important land management tools for tracking ecological changes and preventing irreversible environmental damage in disturbed landscapes. The overall objective of the research was to develop both individual and integrated sets (i.e., statistically derived guilds) of Ecological Indicators to: quantify habitat conditions and trends, track and monitor ecological changes, provide early warning or threshold detection, and provide guidance for land managers. The derivation of Ecological Indicators was based on statistical criteria, ecosystem relevance, reliability and robustness, economy and ease of use for land managers, multi-scale performance, and stress response criteria. The basis for the development of statistically based Ecological Indicators was the identification of ecosystem metrics that analytically tracked a landscape disturbance gradient.

Identification of reluctant factors in using footpaths based on the pedestrians' perception

NASA Astrophysics Data System (ADS)

Hadiyanto, Wahyu; Handayani, Dewi; Yulianto, Budi

2017-06-01

Footpath is a path intended particularly for pedestrians to avoid any conflicts with motor vehicles. However in reality, most of the pedestrians are unwilling to use paths and they prefer to walk on the roads. This research was conducted with the aim to identify the existing condition of pedestrian footpaths based on field observations and to determine the factors that cause the pedestrians are reluctant to walk on the trails. The method used to investigate the pedestrians' perception was by distributing questionnaires to the pedestrians. The results of this study found that the factors that caused the pedestrians did not want to use footpaths were the footpath width, the existence of barriers and obstacles, unstable height (not continuous), damaged surface, non-standard driveway that intersects sidewalk, suboptimal function of ramp, transverse steep slope, and the absence of bollard that could protect footpaths from the access of motorcycles.

Analysis of Stem Cell Motility In Vivo Based on Immunodetection of Planarian Neoblasts and Tracing of BrdU-Labeled Cells After Partial Irradiation.

PubMed

Tasaki, Junichi; Uchiyama-Tasaki, Chihiro; Rouhana, Labib

2016-01-01

Planarian flatworms have become an important system for the study of stem cell behavior and regulation in vivo. These organisms are able to regenerate any part of their body upon damage or amputation. A crucial cellular event in the process of planarian regeneration is the migration of pluripotent stem cells (known as neoblasts) to the site of injury. Here we describe two approaches for analyzing migration of planarian stem cells to an area where these have been ablated by localized X-ray irradiation. The first approach involves immunolabeling of mitotic neoblasts, while the second is based on tracing stem cells and their progeny after BrdU incorporation. The use of planarians in studies of cell motility is suitable for the identification of factors that influence stem cell migration in vivo and is amenable to RNA interference or pharmacological screening.

An acetyl-L-carnitine switch on mitochondrial dysfunction and rescue in the metabolomics study on aluminum oxide nanoparticles.

PubMed

Li, Xiaobo; Zhang, Chengcheng; Zhang, Xin; Wang, Shizhi; Meng, Qingtao; Wu, Shenshen; Yang, Hongbao; Xia, Yankai; Chen, Rui

2016-01-16

Due to the wide application of engineered aluminum oxide nanoparticles and increased aluminum containing particulate matter suspending in air, exposure of human to nano-scale aluminum oxide nanoparticles (Al2O3 NPs) is becoming inevitable. In the present study, RNA microarray coupled with metabolomics analysis were used to uncover mechanisms underlying cellular responses to Al2O3 NPs and imply the potential rescue. We found that Al2O3 NPs significantly triggered down-regulation of mitochondria-related genes located in complex I, IV and V, which were involved in oxidative phosphorylation and neural degeneration pathways, in human bronchial epithelial (HBE) cells. Subsequent cell- and animal- based assays confirmed that Al2O3 NPs caused mitochondria-dependent apoptosis and oxidative stress either in vitro or in vivo, which were consistent with the trends of gene regulation. To rescue the Al2O3 NPs induced mitochondria dysfunction, disruption of small molecular metabolites of HBE were profiled using metabolomics analysis, which facilitates identification of potential antagonizer or supplement against nanoparticle-involved damages. Supplementation of an antioxidant, acetyl-L-carnitine, completely or partially restored the Al2O3 NPs modulated gene expression levels in mitochondrial complex I, IV and V. It further reduced apoptosis and oxidative damages in both Al2O3 NPs treated HBE cells and animal lung tissues. Thus, our results demonstrate the potential mechanism of respiratory system damages induced by Al2O3 NPs. Meanwhile, based on the metabolomics profiling, application of acetyl-L-carnitine is suggested to ameliorate mitochondria dysfunction associated with Al2O3 NPs.

Identification of Damage in Hysteretic Structures.

DTIC Science & Technology

1983-07-01

Hart and Yao [34], Ibanez [51], Ibrahim . [53-58], Milne [59], Raggett, Rodeman, and Yao [32], Ting, Chen, and Yao [35], Udwadia and Shaw [61], and...S 4JJ S- 4 4 cy, m .9-D4 CD- to Ln C~0 Lsd ssa-4 57 0 ’.0 0 𔃾- a., 4.) 0. In In 1..a) o 0*,- a) ~fl .4~) 0) ’- E ~ *i-* E 00 ~ C U r~*, 0 *UC Z eua...and P. C. Shaw , "Identification of Structures Through Records Obtained During Strong Earthquake Ground Motion," Journal of Engineering for Industry

Taqman real-time quantitative PCR for identification of western flower thrip (Frankliniella occidentalis) for plant quarantine

PubMed Central

Huang, K. S.; Lee, S. E.; Yeh, Y.; Shen, G. S.; Mei, E.; Chang, C. M.

2010-01-01

Western flower thrip (Frankliniella occidentalis) is a major global pest of agricultural products. It directly damages crops through feeding, oviposition activity or transmission of several plant viruses. We describe a Taqman real-time quantitative PCR detection system, which can rapidly identify F. occidentalis from thrips larvae to complement the traditional morphological identification. The data showed that our detection system targeted on the ribosomal RNA gene regions of F. occidentalis has high sensitivity and specificity. The rapid method can be used for on-site testing of samples at ports-of-entry in the future. PMID:20129946

Taqman real-time quantitative PCR for identification of western flower thrip (Frankliniella occidentalis) for plant quarantine.

PubMed

Huang, K S; Lee, S E; Yeh, Y; Shen, G S; Mei, E; Chang, C M

2010-08-23

Western flower thrip (Frankliniella occidentalis) is a major global pest of agricultural products. It directly damages crops through feeding, oviposition activity or transmission of several plant viruses. We describe a Taqman real-time quantitative PCR detection system, which can rapidly identify F. occidentalis from thrips larvae to complement the traditional morphological identification. The data showed that our detection system targeted on the ribosomal RNA gene regions of F. occidentalis has high sensitivity and specificity. The rapid method can be used for on-site testing of samples at ports-of-entry in the future.

Airborne mapping of chemical plumes in the aftermath of Hurricanes Katrina and Rita

NASA Astrophysics Data System (ADS)

Lewis, Paul E.; Thomas, Mark J.; Kroutil, Robert T.; Combs, Roger; Cummings, Alan S.; Miller, Dave; Curry, Tim; Shen, Sylvia S.

2006-05-01

Infrared airborne spectral measurements were collected over the Gulf Coast area during the aftermath of Hurricanes Katrina and Rita. These measurements allowed surveillance for potentially hazardous chemical vapor releases from industrial facilities caused by storm damage. Data was collected with a mid-longwave infrared multispectral imager and a hyperspectral Fourier transform infrared spectrometer operating in a low altitude aircraft. Signal processing allowed detection and identification of targeted spectral signatures in the presence of interferents, atmospheric contributions, and thermal clutter. Results confirmed the presence of a number of chemical vapors. All detection results were immediately passed along to emergency first responders on the ground. The chemical identification, location, and vapor species concentration information were used by the emergency response ground teams for identification of critical plume releases and subsequent mitigation.

Stiffness monitoring and damage assessment of bridges under moving vehicular loads using spatially-distributed optical fiber sensors

NASA Astrophysics Data System (ADS)

Wu, Bitao; Wu, Gang; Lu, Huaxi; Feng, De-chen

2017-03-01

Fiber optic sensing technology has been widely used in civil infrastructure health monitoring due to its various advantages, e.g., anti-electromagnetic interference, corrosion resistance, etc. This paper investigates a new method for stiffness monitoring and damage identification of bridges under moving vehicle loads using spatially-distributed optical fiber sensors. The relationship between the element stiffness of the bridge and the long-gauge strain history is firstly studied, and a formula which is expressed by the long-gauge strain history is derived for the calculation of the bridge stiffness. Meanwhile, the stiffness coefficient from the formula can be used to identify the damage extent of the bridge. In order to verify the proposed method, a model test of a 1:10 scale bridge-vehicle system is conducted and the long-gauge strain history is obtained through fiber Bragg grating sensors. The test results indicate that the proposed method is suitable for stiffness monitoring and damage assessment of bridges under moving vehicular loads.

Quantifying Traces of Tool Use: A Novel Morphometric Analysis of Damage Patterns on Percussive Tools

PubMed Central

Caruana, Matthew V.; Carvalho, Susana; Braun, David R.; Presnyakova, Darya; Haslam, Michael; Archer, Will; Bobe, Rene; Harris, John W. K.

2014-01-01

Percussive technology continues to play an increasingly important role in understanding the evolution of tool use. Comparing the archaeological record with extractive foraging behaviors in nonhuman primates has focused on percussive implements as a key to investigating the origins of lithic technology. Despite this, archaeological approaches towards percussive tools have been obscured by a lack of standardized methodologies. Central to this issue have been the use of qualitative, non-diagnostic techniques to identify percussive tools from archaeological contexts. Here we describe a new morphometric method for distinguishing anthropogenically-generated damage patterns on percussive tools from naturally damaged river cobbles. We employ a geomatic approach through the use of three-dimensional scanning and geographical information systems software to statistically quantify the identification process in percussive technology research. This will strengthen current technological analyses of percussive tools in archaeological frameworks and open new avenues for translating behavioral inferences of early hominins from percussive damage patterns. PMID:25415303

[Towards new therapeutic paradigms beyond symptom control in the management of inflammatory bowel diseases.

PubMed

Festa, Stefano; Zerboni, Giulia; Aratari, Annalisa; Ballanti, Riccardo; Papi, Claudio

2018-01-01

Inflammatory bowel diseases, Crohn's disease and ulcerative colitis are chronic relapsing conditions that may result in progressive bowel damage, high risk of complications, surgery and permanent disability. The conventional therapeutic approach for inflammatory bowel diseases is based mainly on symptom control. Unfortunately, a symptom-based therapeutic approach has little impact on major long-term disease outcomes. In other chronic disabling conditions such as diabetes, hypertension and rheumatoid arthritis, the development of new therapeutic approaches has led to better outcomes. In this context a "treat to target" strategy has been developed. This strategy is based on identification of high-risk patients, regular assessment of disease activity by means of objective measures, adjustment of treatment to reach the pre-defined target. A treat to target approach has recently been proposed for inflammatory bowel disease with the aim at modifying the natural history of the disease. In this review, the evidence and the limitations of the treat to target paradigm in inflammatory bowel disease are analyzed and discussed.

Seismic risk evaluation aided by IR thermography

NASA Astrophysics Data System (ADS)

Grinzato, E.; Cadelano, G.; Bison, P.; Petracca, A.

2009-05-01

Conservation of buildings in areas at seismic risk must take prevention into account. The safeguard architectonic heritage is an ambitious objective, but a priority for planning programmes at varying levels of decision making. Preservation and restoration activities must be optimized to cover a vast and widespread historical and architectonic heritage present in many countries. Masonry buildings requires an adequate level of knowledge based on the importance of structural geometry, which may include the damage, details of construction and properties of materials. For identification and classification of masonry is necessary to find shape, type and size of the elements, texture, size of mortar joints, assemblage. The recognition can be done through a visual inspection of the surface of walls, which can be examined, where is not visible, removing a layer of plaster. Thermography is an excellent tool for a fast survey and collection of vital information for this purpose, but it is extremely important define a precise procedure in the development of more efficient monitoring tools. Thermography is a non-destructive method that allows recognizing the structural damage below plaster, detecting the presence of discontinuity in masonry, for added storeys, cavity, filled openings, and repairs. Furthermore, the fast identification of subsurface state allows to select areas where other methods either more penetrating or partially destructive have to be applied. The paper reports experimental results achieved in the mainframe of the European project RECES Modiquus. The main aim of the project is to improve methods, techniques and instruments for facing antiseismic options. Both passive and active thermographic techniques have been applied in different weather conditions and time schemes. A dedicated algorithm has been developed to enhance the visibility of wall bonding.

Identification of bacteria in a biodegraded wall painting by denaturing gradient gel electrophoresis of PCR-amplified gene fragments coding for 16S rRNA.

PubMed Central

Rölleke, S; Muyzer, G; Wawer, C; Wanner, G; Lubitz, W

1996-01-01

Medieval wall paintings are often affected by biodecay. An inventory of the existing microorganisms associated with the damage to the paintings is not yet an integral part of the restoration process. This stems from the lack of effective means for such a stocktaking. Nevertheless, fungi and bacteria cause severe damage through mechanical processes from growth into the painting and its grounding and through their metabolism. Detailed information on the bacterial colonization of ancient wall paintings is essential for the protection of the paintings. We used a molecular approach based on the detection and identification of DNA sequences encoding rRNA (rDNA) to identify bacteria present on an ancient wall painting without prior cultivation of the organisms, since it has been shown that most of these bacteria cannot be cultivated under laboratory conditions. To trace the noncultivated fraction of bacteria, total DNA from a biodegraded wall painting sample from a 13th century fresco was extracted and 194-bp fragments of the 16S rDNA were amplified with eubacterial primers. The 16S rDNA fragments of uniform length obtained from the different bacterial species were separated according to their sequence differences by denaturing gradient gel electrophoresis (DGGE). By sequencing excised and reamplified individual DNA bands, we characterized the phylogenetic affiliation of the corresponding bacteria. Using this approach, we identified members or close relatives of the genera Halomonas, Clostridium, and Frankia. To our knowledge, these groups of bacteria have not yet been isolated and implicated by conventional microbiological techniques as contributing to the biodegradation of wall paintings. PMID:8787403

Experimental investigation on frequency shifting of imperfect adhesively bonded pipe joints

NASA Astrophysics Data System (ADS)

Haiyam, F. N.; Hilmy, I.; Sulaeman, E.; Firdaus, T.; Adesta, E. Y. T.

2018-01-01

Inspection tests for any manufactured structure are compulsory in order to detect the existence of damage.It is to ensure the product integrity, reliability and to avoid further catastrophic failure. In this research, modal analysis was utilized to detect structural damage as one of the Non Destructive Testing (NDT) methods. Comparing the vibration signal of a healthy structure with a non-healthy signal was performed. A modal analysis of an adhesively bonded pipe joint was investigated with a healthy joint as a reference. The damage joint was engineered by inserting a nylon fiber, which act as an impurity at adhesive region. The impact test using hammer was utilized in this research. Identification of shifting frequency of a free supported and clamped pipe joint was performed.It was found that shifting frequency occurred to the lower side by 5%.

Dynamics and Adaptive Control for Stability Recovery of Damaged Aircraft

NASA Technical Reports Server (NTRS)

Nguyen, Nhan; Krishnakumar, Kalmanje; Kaneshige, John; Nespeca, Pascal

2006-01-01

This paper presents a recent study of a damaged generic transport model as part of a NASA research project to investigate adaptive control methods for stability recovery of damaged aircraft operating in off-nominal flight conditions under damage and or failures. Aerodynamic modeling of damage effects is performed using an aerodynamic code to assess changes in the stability and control derivatives of a generic transport aircraft. Certain types of damage such as damage to one of the wings or horizontal stabilizers can cause the aircraft to become asymmetric, thus resulting in a coupling between the longitudinal and lateral motions. Flight dynamics for a general asymmetric aircraft is derived to account for changes in the center of gravity that can compromise the stability of the damaged aircraft. An iterative trim analysis for the translational motion is developed to refine the trim procedure by accounting for the effects of the control surface deflection. A hybrid direct-indirect neural network, adaptive flight control is proposed as an adaptive law for stabilizing the rotational motion of the damaged aircraft. The indirect adaptation is designed to estimate the plant dynamics of the damaged aircraft in conjunction with the direct adaptation that computes the control augmentation. Two approaches are presented 1) an adaptive law derived from the Lyapunov stability theory to ensure that the signals are bounded, and 2) a recursive least-square method for parameter identification. A hardware-in-the-loop simulation is conducted and demonstrates the effectiveness of the direct neural network adaptive flight control in the stability recovery of the damaged aircraft. A preliminary simulation of the hybrid adaptive flight control has been performed and initial data have shown the effectiveness of the proposed hybrid approach. Future work will include further investigations and high-fidelity simulations of the proposed hybrid adaptive Bight control approach.

PREFACE: 11th International Conference on Damage Assessment of Structures (DAMAS 2015)

NASA Astrophysics Data System (ADS)

Wahab, M. A.

2015-07-01

This volume contains the proceedings of the 11th International Conference on Damage Assessment of Structures (DAMAS) 2015. DAMAS has a long history of almost 20 years. The first DAMAS conference took place in 1995 (Pescara, Italy), followed by a biannual meeting in 1997 (Sheffield, UK), 1999 (Dublin, Ireland), 2001 (Cardiff, UK), 2003 (Southampton, UK), 2005 (Gdansk, Poland), 2007 (Torino, Italy), 2009 (Beijing, China), 2011 (Oxford, UK) and 2013 (Dublin, Ireland). The eleventh edition of DAMAS conference series, DAMAS 2015, is hosted by Ghent University, Belgium, and is held at the congress center Het Pand in Ghent city. Ghent is the capital and the largest city of the East Flanders province of the Flemish region of Belgium. Het Pand is the culture and congress center of Ghent University and is a historical monument. The conference is established as a major international forum for research topics relevant to damage assessment of engineering structures and systems including numerical simulations, signal processing of sensor measurements and theoretical techniques as well as experimental case studies. The presentations of DAMAS 2015 are divided into 6 main sessions, namely 1) Structural Health and Condition Monitoring, 2) Damage in Civil Engineering, 3) Damage in Machineries, 4) Damage in Composite Materials, 5) Sensing and Sensors and 6) Signal Processing. The organising committee is grateful to keynote speakers; Professor Guido De Roeck, Head of Structural Mechanics Division, KULeuven, Belgium, for his keynote lecture entitled 'Structural Health Monitoring: highlights and challenges', Professor Weidong Zhu, Department of Mechanical Engineering, University of Maryland, USA, for his keynote lecture entitled 'Vibration-based Structural Damage Detection: Theory and Applications' and Professor Wieslaw Ostachowicz, Head of the Laboratory of Active Materials and Smart Structures, Polish Academy of Sciences, Poland, for his keynote lecture entitled 'Damage Assessment and Reliability in Offshore Wind Turbines Technology'. Special thanks go to members of the Scientific Committee of DAMAS 2015 for reviewing the articles published in this volume and for judging their scientific merits. Based on the comments of reviewers and the scientific merits of the submitted manuscripts, the articles were accepted for publication in the conference proceedings and for presentation at the conference venue. The accepted papers are of a very high scientific quality and contribute to advancement of knowledge in all research topics relevant to DAMAS conference. The organising committee would like to thank prestigious research groups, who made a great contribution to DAMAS 2015: the group of Professor Lars Damkilde, Aalborg University, Denmark; the group of professor Gilbert-Rainer Gillich, Eftimie Murgu University of resita, Romania, the group of Professor Wieslaw Ostachowicz, Polish Academy of Sciences, Poland and the group of Dr Vikram Pakrashi, University College Cork, Ireland. Special thanks go to Dr Vikram Pakrashi for organizing the mini-symposium 'Damage Detection, System Identification and Health Monitoring for Offshore Wind and Wave Energy Devices'. Finally, the organising committee would like to thank all authors, who have contributed to this volume and presented their research work at DAMAS 2015.

Insects and Related Pests of Trees, Shrubs, and Lawns. MP-25R.

ERIC Educational Resources Information Center

Spackman, Everett W.; Lawson, Fred A.

This document discusses identification and control of the pests of trees and shrubs. The insects are grouped according to feeding habits and the type of damage caused to plants. Categories include the sucking insects and mites, leaf eating insects, pests attacking trunks and branches, and gall causing insects. (CS)

Rapid screening for citrus canker resistance employing pattern-triggered immunity (PTI) responses

USDA-ARS?s Scientific Manuscript database

Citrus canker, caused by the bacterial pathogen Xanthomonas citri ssp. citri (Xcc), has been attributed to millions of dollars in loss or damage to commercial citrus crops in subtropical production areas of the world. Since identification of resistant plants is one of the most effective methods of d...

Industrial - Institutional - Structural and Health Related Pest Control Category Manual.

ERIC Educational Resources Information Center

Bowman, James S.; Turmel, Jon P.

This manual provides information needed to meet the standards for pesticide applicator certification. The emphasis of this document is on the identification of wood-destroying pests and the damage caused by them to the structural components of buildings. The pests discussed include termites, carpenter ants, beetles, bees, and wasps and numerous…

Pheromone of the banana-spotting bug, amblypelta lutescens lutescens Distant (Hemiptera: Coreidae): identification, synthesis and field bioassay

USDA-ARS?s Scientific Manuscript database

The banana spotting bug Amblypelta lutescens lutescens Distant (Hemiptera: Coreidae) is one of the principal pests of tree fruits and nuts across northern and eastern Australia. Apart from damage assessments in orchards, there are currently no other methods for monitoring bug activity to aid manage...

Identification and Targeting of Tyrosine Kinase Activity in Prostate Cancer Initiation, Progression, and Metastasis

DTIC Science & Technology

2013-12-01

University) "Effectors of the DNA damage and radiotherapy response in cancer" 9:20 pm - 9:30 pm Discussion TUESDAY 7:30 am - 8:30 am Breakfast 9:00...M. Morris , Hideki Onagi, Timothy M. Altamore, Allan B. Gamble, Christopher J. Easton Prohormone-substrate peptide sequence recognition by

Suspect until Proven Guilty a Problematization of State Dossier Systems via Two Case Studies: The United States and China

ERIC Educational Resources Information Center

Farrall, Kenneth N.

2009-01-01

This dissertation problematizes the "state dossier system" (SDS): the production and accumulation of personal information on citizen subjects exceeding the reasonable bounds of risk management. SDS--comprising interconnecting subsystems of records and identification--damage individual autonomy and self-determination, impacting not only…

Substrates of the Arabidopsis thaliana protein isoaspartyl methyltransferasel identified using phage display and biopanning

USDA-ARS?s Scientific Manuscript database

The role of PROTEIN ISOASPARTYL-METHYLTRANSFERASE (PIMT) in repairing a wide assortment of damaged proteins in a host of organisms has been inferred from the affinity of the enzyme for isoaspartyl residues in a plethora of amino acid contexts. The identification of specific PIMT target proteins in p...

Identification and confirmation of greenbug resistance loci in an advanced mapping population of sorghum

USDA-ARS?s Scientific Manuscript database

Greenbug infestations to sorghum can cause severe and above economic threshold damage in the Great Plains of the United States. This study was to identify quantitative trait loci (QTL) and potential candidate genes residing within the QTL region responsible for greenbug resistance in an advanced ma...

Lipid biomarker analysis for the quantitative analysis of airborne microorganisms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Macnaughton, S.J.; Jenkins, T.L.; Cormier, M.R.

1997-08-01

There is an ever increasing concern regarding the presence of airborne microbial contaminants within indoor air environments. Exposure to such biocontaminants can give rise to large numbers of different health effects including infectious diseases, allergenic responses and respiratory problems, Biocontaminants typically round in indoor air environments include bacteria, fungi, algae, protozoa and dust mites. Mycotoxins, endotoxins, pollens and residues of organisms are also known to cause adverse health effects. A quantitative detection/identification technique independent of culturability that assays both culturable and non culturable biomass including endotoxin is critical in defining risks from indoor air biocontamination. Traditionally, methods employed for themore » monitoring of microorganism numbers in indoor air environments involve classical culture based techniques and/or direct microscopic counting. It has been repeatedly documented that viable microorganism counts only account for between 0.1-10% of the total community detectable by direct counting. The classic viable microbiologic approach doe`s not provide accurate estimates of microbial fragments or other indoor air components that can act as antigens and induce or potentiate allergic responses. Although bioaerosol samplers are designed to damage the microbes as little as possible, microbial stress has been shown to result from air sampling, aerosolization and microbial collection. Higher collection efficiency results in greater cell damage while less cell damage often results in lower collection efficiency. Filtration can collect particulates at almost 100% efficiency, but captured microorganisms may become dehydrated and damaged resulting in non-culturability, however, the lipid biomarker assays described herein do not rely on cell culture. Lipids are components that are universally distributed throughout cells providing a means to assess independent of culturability.« less

The KnowRISK project: Tools and strategies to reduce non-structural damage

NASA Astrophysics Data System (ADS)

Sousa Oliveira, Carlos; Lopes, Mário; Mota de Sá, Francisco; Amaral Ferreia, Mónica; Candeias, Paulo; Campos Costa, Alfredo; Rupakhety, Rajesh; Meroni, Fabrizio; Azzaro, Raffaele; D'Amico, Salvatore; Langer, Horst; Musacchio, Gemma; Sousa Silva, Delta; Falsaperla, Susanna; Scarfì, Luciano; Tusa, Giuseppina; Tuvé, Tiziana

2016-04-01

The project KnowRISK (Know your city, Reduce seISmic risK through non-structural elements) is financed by the European Commission to develop prevention measures that may reduce non-structural damage in urban areas. Pilot areas of the project are within the three European participating countries, namely Portugal, Iceland and Italy. Non-structural components of a building include all those components that are not part of the structural system, more specifically the architectural, mechanical, electrical, and plumbing systems, as well as furniture, fixtures, equipment, and contents. Windows, partitions, granite veneer, piping, ceilings, air conditioning ducts and equipment, elevators, computer and hospital equipment, file cabinets, and retail merchandise are all examples of non-structural components that are vulnerable to earthquake damage. We will use the experience gained during past earthquakes, which struck in particular Iceland, Italy and Portugal (Azores). Securing the non-structural elements improves the safety during an earthquake and saves lives. This paper aims at identifying non-structural seismic protection measures in the pilot areas and to develop a portfolio of good practices for the most common and serious non-structural vulnerabilities. This systematic identification and the portfolio will be achieved through a "cross-knowledge" strategy based on previous researches, evidence of non-structural damage in past earthquakes. Shake table tests of a group of non-structural elements will be performed. These tests will be filmed and, jointly with portfolio, will serve as didactic supporting tools to be used in workshops with building construction stakeholders and in risk communication activities. A Practical Guide for non-structural risk reduction will be specifically prepared for citizens on the basis of the outputs of the project, taking into account the local culture and needs of each participating country.

HAIR FOLLICLE CHARACTERISTICS AS EARLY MARKER OF TYPE 2 DIABETES

PubMed Central

Miranda, J. Jaime; Taype-Rondan, Alvaro; Tapia, Jose Carlos; Gastanadui-Gonzalez, Maria Gabriela; Roman-Carpio, Ricardo

2016-01-01

Type 2 Diabetes mellitus (DM2) includes a continuum of metabolic disorders characterized by hyperglycemia that causes several chronic long-term complications such as coronary artery disease, peripheral arterial disease, nephropathy, and neuropathy. The hair follicle could reveal signs of early vascular impairment, yet its relationship to early metabolic injuries has been largely ignored. We propose that in earlier stages of the continuum of DM2-related metabolic disorders, a group of susceptible patients who do not yet meet the diagnostic criteria to be considered as persons with DM2 may present chronic vascular impairment and end organ damage, including hair follicle damage, which can be evaluated to identify an early risk marker. This hypothesis is based in the association found between insulin resistance and alopecia in non-diabetic persons, and the hair loss on the lower limbs as a manifestation of long-term peripheral arterial disease among subjects with DM2. In order to test this hypothesis, studies are required to evaluate if hair follicle characteristics are related to and can predict hyperglycemic complications, and if they do so, which feature of the hair follicle, such as hair growth, best characterizes such DM2-related conditions. If this hypothesis were proven to be true, significant advances towards a personalized approach for early prevention strategies and management of DM2 would be made. By focusing on the hair follicles, early stages of metabolic-related organ damage could be identified using non-invasive low-cost techniques. In so doing, this approach could provide early identification of DM2-susceptible individuals and lead to the early initiation of adequate primary prevention strategies to reduce or avoid the onset of large internal organ damage. PMID:27692164

Hair follicle characteristics as early marker of Type 2 Diabetes.

PubMed

Miranda, J Jaime; Taype-Rondan, Alvaro; Tapia, Jose Carlos; Gastanadui-Gonzalez, Maria Gabriela; Roman-Carpio, Ricardo

2016-10-01

Type 2 Diabetes mellitus (DM2) includes a continuum of metabolic disorders characterized by hyperglycemia that causes several chronic long-term complications such as coronary artery disease, peripheral arterial disease, nephropathy, and neuropathy. The hair follicle could reveal signs of early vascular impairment, yet its relationship to early metabolic injuries has been largely ignored. We propose that in earlier stages of the continuum of DM2-related metabolic disorders, a group of susceptible patients who do not yet meet the diagnostic criteria to be considered as persons with DM2 may present chronic vascular impairment and end organ damage, including hair follicle damage, which can be evaluated to identify an early risk marker. This hypothesis is based in the association found between insulin resistance and alopecia in non-diabetic persons, and the hair loss on the lower limbs as a manifestation of long-term peripheral arterial disease among subjects with DM2. In order to test this hypothesis, studies are required to evaluate if hair follicle characteristics are related to and can predict hyperglycemic complications, and if they do so, which feature of the hair follicle, such as hair growth, best characterizes such DM2-related conditions. If this hypothesis were proven to be true, significant advances towards a personalized approach for early prevention strategies and management of DM2 would be made. By focusing on the hair follicles, early stages of metabolic-related organ damage could be identified using non-invasive low-cost techniques. In so doing, this approach could provide early identification of DM2-susceptible individuals and lead to the early initiation of adequate primary prevention strategies to reduce or avoid the onset of large internal organ damage. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chemistry of MOS-LSI radiation hardening

NASA Technical Reports Server (NTRS)

Grunthaner, P.

1985-01-01

The objective of this task was to obtain chemical information on MOS test samples. Toward this end, high resolution X-ray photoemission spectroscopy (XPS) has been the primary techniques used to characterize the chemistry and structure of the SiO2/Si interface for a variety of MOS structures with differing degrees of susceptibility to damage by ionizing radiation. The major accomplishments of this program are: (1) the identification of a structurally distinct region of SiO2 in the near-interfacial region of thermal SiO2 on Si; (2) the identification in the near-interfacial region of SiO2 structural differences between radiation hard and soft gate oxides; (3) the direct observation of radiation-induced damage sites in thermal SiO2 with XPS using in situ electron stress; (4) the correlation of suboxide state distributions at the SiO2/Si interface with processing parameters and radiation susceptibility; (5) the development of a chemical mechanism for radiation-induced interface state generation in SiO2/Si structures; and (6) the development benign chemical profiling techniques which permit the investigation of oxide/semiconductor structures using surface sensitive electron spectroscopic techniques.

Blind identification of full-field vibration modes of output-only structures from uniformly-sampled, possibly temporally-aliased (sub-Nyquist), video measurements

NASA Astrophysics Data System (ADS)

Yang, Yongchao; Dorn, Charles; Mancini, Tyler; Talken, Zachary; Nagarajaiah, Satish; Kenyon, Garrett; Farrar, Charles; Mascareñas, David

2017-03-01

Enhancing the spatial and temporal resolution of vibration measurements and modal analysis could significantly benefit dynamic modelling, analysis, and health monitoring of structures. For example, spatially high-density mode shapes are critical for accurate vibration-based damage localization. In experimental or operational modal analysis, higher (frequency) modes, which may be outside the frequency range of the measurement, contain local structural features that can improve damage localization as well as the construction and updating of the modal-based dynamic model of the structure. In general, the resolution of vibration measurements can be increased by enhanced hardware. Traditional vibration measurement sensors such as accelerometers have high-frequency sampling capacity; however, they are discrete point-wise sensors only providing sparse, low spatial sensing resolution measurements, while dense deployment to achieve high spatial resolution is expensive and results in the mass-loading effect and modification of structure's surface. Non-contact measurement methods such as scanning laser vibrometers provide high spatial and temporal resolution sensing capacity; however, they make measurements sequentially that requires considerable acquisition time. As an alternative non-contact method, digital video cameras are relatively low-cost, agile, and provide high spatial resolution, simultaneous, measurements. Combined with vision based algorithms (e.g., image correlation or template matching, optical flow, etc.), video camera based measurements have been successfully used for experimental and operational vibration measurement and subsequent modal analysis. However, the sampling frequency of most affordable digital cameras is limited to 30-60 Hz, while high-speed cameras for higher frequency vibration measurements are extremely costly. This work develops a computational algorithm capable of performing vibration measurement at a uniform sampling frequency lower than what is required by the Shannon-Nyquist sampling theorem for output-only modal analysis. In particular, the spatio-temporal uncoupling property of the modal expansion of structural vibration responses enables a direct modal decoupling of the temporally-aliased vibration measurements by existing output-only modal analysis methods, yielding (full-field) mode shapes estimation directly. Then the signal aliasing properties in modal analysis is exploited to estimate the modal frequencies and damping ratios. The proposed method is validated by laboratory experiments where output-only modal identification is conducted on temporally-aliased acceleration responses and particularly the temporally-aliased video measurements of bench-scale structures, including a three-story building structure and a cantilever beam.

PARP inhibitors--current status and the walk towards early breast cancer.

PubMed

Glendenning, Jennifer; Tutt, Andrew

2011-10-01

Epithelial carcinomas in general arise as a result of the acquisition of and selection for multiple mutations in a parental somatic cell clone within the tissues of the primary organ of origin. In the last two decades genome caretakers, which function in key areas of DNA damage response, have been recognized as important tumour suppressor genes. Inactivating mutations in these genes occur both as germline and/or somatic mutations with increasing evidence of epigenetic silencing as an additional cause of loss of function. In any event, loss of function in a tumour cell pre-cursor clone leads to accelerated mutation acquisition and underpins the aetiology of the tumour. With increasing understanding of the complex network that is the DNA damage response, signaling pathways already recognized to be central to the establishment of the cancer phenotype are gaining additional roles as controllers of DNA repair. This has relevance to identification of wider populations of patients with tumours susceptible to approaches that target DNA repair deficiency. These have classically been with DNA damaging chemotherapy but the recently developed small molecule inhibitors of DNA repair enzymes such as Poly-ADP polymerases PARP-1 and PARP-2 have been shown to target tumour deficiencies in DNA repair as well sensitizing to DNA damaging therapeutics such as radiation and chemotherapy. Early phase trials with efficacy endpoints have been presented for the PARP inhibitors AG014699, olaparib, veliparib, iniparib and MK4827. The results of the first phase II trials exploring monotherapy PARP inhibitor strategies, which are based on revisiting the concept of synthetic lethality, have emerged and are reviewed herein. The clinical trials that have or are exploring combinations with DNA damaging therapy in these contexts are discussed with particular reference to breast cancer, as are biomarkers that have been proposed and are being investigated to develop optimal drug schedule and patient selection criteria for these DNA repair targeting approaches. Copyright © 2011 Elsevier Ltd. All rights reserved.

Research on on-line monitoring technology for steel ball's forming process based on load signal analysis method

NASA Astrophysics Data System (ADS)

Li, Ying-jun; Ai, Chang-sheng; Men, Xiu-hua; Zhang, Cheng-liang; Zhang, Qi

2013-04-01

This paper presents a novel on-line monitoring technology to obtain forming quality in steel ball's forming process based on load signal analysis method, in order to reveal the bottom die's load characteristic in initial cold heading forging process of steel balls. A mechanical model of the cold header producing process is established and analyzed by using finite element method. The maximum cold heading force is calculated. The results prove that the monitoring on the cold heading process with upsetting force is reasonable and feasible. The forming defects are inflected on the three feature points of the bottom die signals, which are the initial point, infection point, and peak point. A novel PVDF piezoelectric force sensor which is simple on construction and convenient on installation is designed. The sensitivity of the PVDF force sensor is calculated. The characteristics of PVDF force sensor are analyzed by FEM. The PVDF piezoelectric force sensor is fabricated to acquire the actual load signals in the cold heading process, and calibrated by a special device. The measuring system of on-line monitoring is built. The characteristics of the actual signals recognized by learning and identification algorithm are in consistence with simulation results. Identification of actual signals shows that the timing difference values of all feature points for qualified products are not exceed ±6 ms, and amplitude difference values are less than ±3%. The calibration and application experiments show that PVDF force sensor has good static and dynamic performances, and is competent at dynamic measuring on upsetting force. It greatly improves automatic level and machining precision. Equipment capacity factor with damages identification method depends on grade of steel has been improved to 90%.

Biomarkers of aging in Drosophila.

PubMed

Jacobson, Jake; Lambert, Adrian J; Portero-Otín, Manuel; Pamplona, Reinald; Magwere, Tapiwanashe; Miwa, Satomi; Driege, Yasmine; Brand, Martin D; Partridge, Linda

2010-08-01

Low environmental temperature and dietary restriction (DR) extend lifespan in diverse organisms. In the fruit fly Drosophila, switching flies between temperatures alters the rate at which mortality subsequently increases with age but does not reverse mortality rate. In contrast, DR acts acutely to lower mortality risk; flies switched between control feeding and DR show a rapid reversal of mortality rate. Dietary restriction thus does not slow accumulation of aging-related damage. Molecular species that track the effects of temperatures on mortality but are unaltered with switches in diet are therefore potential biomarkers of aging-related damage. However, molecular species that switch upon instigation or withdrawal of DR are thus potential biomarkers of mechanisms underlying risk of mortality, but not of aging-related damage. Using this approach, we assessed several commonly used biomarkers of aging-related damage. Accumulation of fluorescent advanced glycation end products (AGEs) correlated strongly with mortality rate of flies at different temperatures but was independent of diet. Hence, fluorescent AGEs are biomarkers of aging-related damage in flies. In contrast, five oxidized and glycated protein adducts accumulated with age, but were reversible with both temperature and diet, and are therefore not markers either of acute risk of dying or of aging-related damage. Our approach provides a powerful method for identification of biomarkers of aging.

Biomarkers of ageing in Drosophila

PubMed Central

Jacobson, Jake; Portero-Otín, Manuel; Pamplona, Reinald; Magwere, Tapiwanashe; Miwa, Satomi; Driege, Yasmine; Brand, Martin D.; Partridge, Linda

2015-01-01

Summary Low environmental temperature and dietary restriction (DR) extend lifespan in diverse organisms. In the fruit fly Drosophila, switching flies between temperatures alters the rate at which mortality subsequently increases with age but does not reverse mortality rate. In contrast, DR acts acutely to lower mortality risk; flies switched between control feeding and DR show a rapid reversal of mortality rate. DR thus does not slow accumulation of ageing-related damage. Molecular species that track the effects of temperatures on mortality but are unaltered with switches in diet are therefore potential biomarkers of ageing-related damage. However, molecular species that switch upon instigation or withdrawal of DR are thus potential biomarkers of mechanisms underlying risk of mortality, but not of ageing-related damage. Using this approach, we assessed several commonly used biomarkers of ageing-related damage. Accumulation of fluorescent advanced glycation end products (AGEs) correlated strongly with mortality rate of flies at different temperatures but was independent of diet. Hence fluorescent AGEs are biomarkers of ageing-related damage in flies. In contrast, five oxidised and glycated protein adducts accumulated with age, but were reversible with both temperature and diet, and are therefore not markers either of acute risk of dying or of ageing-related damage. Our approach provides a powerful method for identification of biomarkers of ageing. PMID:20367621

On the threshold conditions for electron beam damage of asbestos amosite fibers in the transmission electron microscope (TEM).

PubMed

Martin, Joannie; Beauparlant, Martin; Sauvé, Sébastien; L'Espérance, Gilles

2016-12-01

Asbestos amosite fibers were investigated to evaluate the damage caused by a transmission electron microscope (TEM) electron beam. Since elemental x-ray intensity ratios obtained by energy dispersive x-ray spectroscopy (EDS) are commonly used for asbestos identification, the impact of beam damage on these ratios was evaluated. It was determined that the magnesium/silicon ratio best represented the damage caused to the fiber. Various tests showed that most fibers have a current density threshold above which the chemical composition of the fiber is modified. The value of this threshold current density varied depending on the fiber, regardless of fiber diameter, and in some cases could not be determined. The existence of a threshold electron dose was also demonstrated. This value was dependent on the current density used and can be increased by providing a recovery period between exposures to the electron beam. This study also established that the electron beam current is directly related to the damage rate above a current density of 165 A/cm 2 . The large number of different results obtained suggest, that in order to ensure that the amosite fibers are not damaged, analysis should be conducted below a current density of 100 A/cm 2 .

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hopmann, Ch., E-mail: kerschbaum@ikv.rwth-aachen.de; Kerschbaum, M., E-mail: kerschbaum@ikv.rwth-aachen.de; Küsters, K., E-mail: kerschbaum@ikv.rwth-aachen.de

The evaluation of damages caused during processing, assembly or usage of fibre reinforced plastics is still a challenge. The use of inspection technology like ultrasonic scanning enables a detailed damage analysis but requires high investments and trained staff. Therefore, the visual inspection method is widely used. A drawback of this method is the difficult identification of barely visible damages, which can already be detrimental for the structural integrity. Therefore an approach is undertaken to integrate microencapsulated dyes into the laminates of fibre reinforced plastic parts to highlight damages on the surface. In case of a damage, the microcapsules rupture whichmore » leads to a release of the dye and a visible bruise on the part surface. To enable a wide application spectrum for this technology the microcapsules must be processable without rupturing with established manufacturing processes for fibre reinforced plastics. Therefore the incorporation of microcapsules in the filament winding, prepreg autoclave and resin transfer moulding (RTM) process is investigated. The results show that the use of a carrier medium is a feasible way to incorporate the microcapsules into the laminate for all investigated manufacturing processes. Impact testing of these laminates shows a bruise formation on the specimen surface which correlates with the impact energy level. This indicates a microcapsule survival during processing and shows the potential of this technology for damage detection and characterization.« less

Identification Damage Model for Thermomechanical Degradation of Ductile Heterogeneous Materials

NASA Astrophysics Data System (ADS)

Amri, A. El; Yakhloufi, M. H. El; Khamlichi, A.

2017-05-01

The failure of ductile materials subject to high thermal and mechanical loading rates is notably affected by material inertia. The mechanisms of fatigue-crack propagation are examined with particular emphasis on the similarities and differences between cyclic crack growth in ductile materials, such as metals, and corresponding behavior in brittle materials, such as intermetallic and ceramics. Numerical simulations of crack propagation in a cylindrical specimen demonstrate that the proposed method provides an effective means to simulate ductile fracture in large scale cylindrical structures with engineering accuracy. The influence of damage on the intensity of the destruction of materials is studied as well.

Differences in emotional well-being of hurricane survivors: a secondary analysis of the ABC News Hurricane Katrina Anniversary Poll.

PubMed

Rateau, Margaret R

2009-06-01

Literature suggests that survivors of catastrophic loss may suffer long-term emotional damage. This paper presents a secondary data analysis from the ABC News Hurricane Katrina Poll conducted in August, 2006. Following analyses, a significantly higher percentage of women (44%) and those who experienced residential damage (66.7%) reported long-term negative impact on emotional well-being. Overall, 70.3% of Katrina survivors reported a strengthening in fellow man following the disaster. These results may serve as beginning evidence for appropriate identification and implementation of mental health support for those most in need following disaster.

Dynamic Method of Neutral Axis Position Determination and Damage Identification with Distributed Long-Gauge FBG Sensors

PubMed Central

Tang, Yongsheng; Ren, Zhongdao

2017-01-01

The neutral axis position (NAP) is a key parameter of a flexural member for structure design and safety evaluation. The accuracy of NAP measurement based on traditional methods does not satisfy the demands of structural performance assessment especially under live traffic loads. In this paper, a new method to determine NAP is developed by using modal macro-strain (MMS). In the proposed method, macro-strain is first measured with long-gauge Fiber Bragg Grating (FBG) sensors; then the MMS is generated from the measured macro-strain with Fourier transform; and finally the neutral axis position coefficient (NAPC) is determined from the MMS and the neutral axis depth is calculated with NAPC. To verify the effectiveness of the proposed method, some experiments on FE models, steel beam and reinforced concrete (RC) beam were conducted. From the results, the plane section was first verified with MMS of the first bending mode. Then the results confirmed the high accuracy and stability for assessing NAP. The results also proved that the NAPC was a good indicator of local damage. In summary, with the proposed method, accurate assessment of flexural structures can be facilitated. PMID:28230747

Genotoxicity testing: progress and prospects for the next decade.

PubMed

Turkez, Hasan; Arslan, Mehmet E; Ozdemir, Ozlem

2017-10-01

Genotoxicity and mutagenicity analyses have a significant role in the identification of hazard effects of therapeutic drugs, cosmetics, agrochemicals, industrial compounds, food additives, natural toxins and nanomaterials for regulatory purposes. To evaluate mutagenicity or genotoxicity, different in vitro and in vivo methodologies exert various genotoxicological endpoints such as point mutations, changes in number and structure of chromosomes. Areas covered: This review covered the basics of genotoxicity and in vitro/in vivo methods for determining of genetic damages. The limitations that have arisen as a result of the common use of these methods were also discussed. Finally, the perspectives of further prospects on the use of genotoxicity testing and genotoxic mode of action were emphasized. Expert opinion: The solution of actual and practical problems of genetic toxicology is inarguably based on the understanding of DNA damage mechanisms at molecular, subcellular, cellular, organ, system and organism levels. Current strategies to investigate human health risks should be modified to increase their performance for more reliable results and also new techniques such as toxicogenomics, epigenomics and single cell approaches must be integrated into genetic safety evolutions. The explored new biomarkers by the omic techniques will provide forceful genotoxicity assessment to reduce the cancer risk.

A Systematic Review of Quantitative Resilience Measures for Water Infrastructure Systems

DOE PAGES

Shin, Sangmin; Lee, Seungyub; Judi, David; ...

2018-02-07

Over the past few decades, the concept of resilience has emerged as an important consideration in the planning and management of water infrastructure systems. Accordingly, various resilience measures have been developed for the quantitative evaluation and decision-making of systems. There are, however, numerous considerations and no clear choice of which measure, if any, provides the most appropriate representation of resilience for a given application. This study provides a critical review of quantitative approaches to measure the resilience of water infrastructure systems, with a focus on water resources and distribution systems. A compilation of 11 criteria evaluating 21 selected resilience measuresmore » addressing major features of resilience is developed using the Axiomatic Design process. Existing gaps of resilience measures are identified based on the review criteria. The results show that resilience measures have generally paid less attention to cascading damage to interrelated systems, rapid identification of failure, physical damage of system components, and time variation of resilience. Concluding the paper, improvements to resilience measures are recommended. The findings contribute to our understanding of gaps and provide information to help further improve resilience measures of water infrastructure systems.« less

A Systematic Review of Quantitative Resilience Measures for Water Infrastructure Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shin, Sangmin; Lee, Seungyub; Judi, David

Over the past few decades, the concept of resilience has emerged as an important consideration in the planning and management of water infrastructure systems. Accordingly, various resilience measures have been developed for the quantitative evaluation and decision-making of systems. There are, however, numerous considerations and no clear choice of which measure, if any, provides the most appropriate representation of resilience for a given application. This study provides a critical review of quantitative approaches to measure the resilience of water infrastructure systems, with a focus on water resources and distribution systems. A compilation of 11 criteria evaluating 21 selected resilience measuresmore » addressing major features of resilience is developed using the Axiomatic Design process. Existing gaps of resilience measures are identified based on the review criteria. The results show that resilience measures have generally paid less attention to cascading damage to interrelated systems, rapid identification of failure, physical damage of system components, and time variation of resilience. Concluding the paper, improvements to resilience measures are recommended. The findings contribute to our understanding of gaps and provide information to help further improve resilience measures of water infrastructure systems.« less

Computational Model for Impact-Resisting Critical Thickness of High-Speed Machine Outer Protective Plate

NASA Astrophysics Data System (ADS)

Wu, Huaying; Wang, Li Zhong; Wang, Yantao; Yuan, Xiaolei

2018-05-01

The blade or surface grinding blade of the hypervelocity grinding wheel may be damaged due to too high rotation rate of the spindle of the machine and then fly out. Its speed as a projectile may severely endanger the field persons. Critical thickness model of the protective plate of the high-speed machine is studied in this paper. For easy analysis, the shapes of the possible impact objects flying from the high-speed machine are simplified as sharp-nose model, ball-nose model and flat-nose model. Whose front ending shape to represent point, line and surface contacting. Impact analysis based on J-C model is performed for the low-carbon steel plate with different thicknesses in this paper. One critical thickness computational model for the protective plate of high-speed machine is established according to the damage characteristics of the thin plate to get relation among plate thickness and mass, shape and size and impact speed of impact object. The air cannon is used for impact test. The model accuracy is validated. This model can guide identification of the thickness of single-layer outer protective plate of a high-speed machine.

Developmental approach towards high resolution optical coherence tomography for glaucoma diagnostics

NASA Astrophysics Data System (ADS)

Kemper, Björn; Ketelhut, Steffi; Heiduschka, Peter; Thorn, Marie; Larsen, Michael; Schnekenburger, Jürgen

2018-02-01

Glaucoma is caused by a pathological rise in the intraocular pressure, which results in a progressive loss of vision by a damage to retinal cells and the optical nerve head. Early detection of pressure-induced damage is thus essential for the reduction of eye pressure and to prevent severe incapacity or blindness. Within the new European Project GALAHAD (Glaucoma Advanced, Label free High Resolution Automated OCT Diagnostics), we will develop a new low-cost and high-resolution OCT system for the early detection of glaucoma. The device is designed to improve diagnosis based on a new system of optical coherence tomography. Although OCT systems are at present available in ophthalmology centres, high-resolution devices are extremely expensive. The novelty of the new Galahad system is its super wideband light source to achieve high image resolution at a reasonable cost. Proof of concept experiments with cell and tissue Glaucoma test standards and animal models are planned for the test of the new optical components and new algorithms performance for the identification of Glaucoma associated cell and tissue structures. The intense training of the software systems with various samples should result in a increased sensitivity and specificity of the OCT software system.

A conceptual framework for evaluating tsunami resilience

NASA Astrophysics Data System (ADS)

Pushpalal, Dinil

2017-02-01

As many coastal towns in the northeast coast of Japan were destroyed by tsunami accompanied with the Great East Japan Earthquake, a few of them were survived or little damaged with no or less casualties due to some reasons. Yoshihama in Iwate prefecture is one of such little damaged communities and is known as “Lucky Beach.” There were such “lucky” and “unlucky” regions in Indonesia and Sri Lanka too, which were affected by Indian Ocean Tsunami. Identification of reasons for vulnerability or resilience is the primary consideration of this article. It presents pragmatic conceptual framework for evaluating resilience, based on author’s firsthand experience on above both tsunamis. Integral resilience of a given area has been considered after dividing into three phases namely, onsite resilience, instantaneous survivability, and recovery potentiality of the area. The author assumes that capacity of each phase depends on socioeconomic, infrastructural and geographical factors of the area considered. The paper moves forward, arguing appropriateness of the framework by giving examples collected from Japan, Indonesia and Sri Lanka. The framework will be useful for evaluating resilience of coastal townships and also planning resilient townships, specifically focusing on tsunami.

Disease severity index derived from hemolysis evaluation

NASA Astrophysics Data System (ADS)

Piskin, Senol; Finol, Ender A.; Pekkan, Kerem; Vascular Biomechanics; Biofluids Laboratory (VBBL) Team; Pediatric Cardiovascular Fluid Mechanics Laboratory Team

2017-11-01

Several cardiovascular diseases (CVDs) are characterized by stenosis of the vessel, leaflet malfunction, disturbance of blood flow (vorticity) due to geometric deformation or abnormal growth, and development of jet flow due to ventricle overload. All of these abnormalities are followed by degeneration of inner wall of the heart and the arteries and red blood cell damage (hemolysis). In this study, identification and classification of CVDs are being performed based on hemolysis evaluation (HE). Two commonly used hemolysis models are implemented to our computational fluid dynamics simulations of CV system. The capability of HE on disease diagnosis is investigated. The analysis will be carried out on our CVD templates such as artery stenosis or pulmonary artery hypertension. HEs depend mainly on the strain rate and for some computational hemolysis models there is a threshold of strain of which the hemolysis will not take place. In the current study, we investigate the effect of thresholding besides using pseudo exposure time for steady state simulations on the blood damage evaluations. Details of our methodology for HE by post processing simulation results without necessity of re-running the simulations will be presented. American Heart Association, National Institute of Health, European Research Council, TUBITAK.

Optimizing phytoremediation of heavy metal-contaminated soil by exploiting plants' stress adaptation.

PubMed

Barocsi, Attila; Csintalan, Zsolt; Kocsanyi, Laszlo; Dushenkov, Slavik; Kuperberg, J Michael; Kucharski, Rafal; Richter, Peter I

2003-01-01

Soil phytoextraction is based on the ability of plants to extract contaminants from the soil. For less bioavailable metals, such as Pb, a chelator is added to the soil to mobilize the metal. The effect can be significant and in certain species, heavy metal accumulation can rapidly increase 10-fold. Accumulation of high levels of toxic metals may result in irreversible damage to the plant. Monitoring and controlling the phytotoxicity caused by EDTA-induced metal accumulation is crucial to optimize the remedial process, i.e. to achieve maximum uptake. We describe an EDTA-application procedure that minimizes phytotoxicity by increasing plant tolerance and allows phytoextraction of elevated levels of Pb and Cd. Brassica juncea is tested in soil with typical Pb and Cd concentrations of 500 mg kg-1 and 15 mg kg-1, respectively. Instead of a single dose treatment, the chelator is applied in multiple doses, that is, in several small increments, thus providing time for plants to initiate their adaptation mechanisms and raise their damage threshold. In situ monitoring of plant stress conditions by chlorophyll fluorescence recording allows for the identification of the saturating heavy metal accumulation process and of simultaneous plant deterioration.

Dynamic Method of Neutral Axis Position Determination and Damage Identification with Distributed Long-Gauge FBG Sensors.

PubMed

Tang, Yongsheng; Ren, Zhongdao

2017-02-20

The neutral axis position (NAP) is a key parameter of a flexural member for structure design and safety evaluation. The accuracy of NAP measurement based on traditional methods does not satisfy the demands of structural performance assessment especially under live traffic loads. In this paper, a new method to determine NAP is developed by using modal macro-strain (MMS). In the proposed method, macro-strain is first measured with long-gauge Fiber Bragg Grating (FBG) sensors; then the MMS is generated from the measured macro-strain with Fourier transform; and finally the neutral axis position coefficient (NAPC) is determined from the MMS and the neutral axis depth is calculated with NAPC. To verify the effectiveness of the proposed method, some experiments on FE models, steel beam and reinforced concrete (RC) beam were conducted. From the results, the plane section was first verified with MMS of the first bending mode. Then the results confirmed the high accuracy and stability for assessing NAP. The results also proved that the NAPC was a good indicator of local damage. In summary, with the proposed method, accurate assessment of flexural structures can be facilitated.

Photoactive and self-sensing P3HT-based thin films for strain and corrosion monitoring

NASA Astrophysics Data System (ADS)

Ryu, Donghyeon; Loh, Kenneth J.

2014-03-01

Structural systems deteriorate due to excessive deformation and corrosive environments. If damage is left undetected, they can propagate to cause sudden collapse. However, one of the main difficulties of monitoring damage progression is that, for example, excessive/plastic deformation and corrosion are drastically different physical processes. Strain is a mechanical phenomenon, whereas corrosion is a complex electrochemical process. The current strategy for structural health monitoring (SHM) is to use either different types of sensors or to employ system identification for quantifying overall changes to the structure. In this study, an alternative SHM paradigm is proposed in that a single, multifunctional material would be able to selectively sense different but simultaneously occurring structural damage. In particular, a photoactive and self-sensing thin film was developed for monitoring strain and corrosion. Another unique aspect was that the films were self-sensing and did not depend on external electrical energy for operations. First, the thin films were fabricated using photoactive poly(3-hexylthiophene) (P3HT) and other functional polymers using spin-coating and layerby- layer assembly. Second, the fabricated thin films were interrogated using an ultraviolet-visible (UV-Vis) spectrophotometer for quantifying their optical response to applied external stimuli, such as strain and exposure to pH buffer solutions. Lastly, the multifunctional thin films were tested and validated for strain and pH sensing. Interrogation of these separate responses was achieved by illuminating the thin films different wavelengths of light and then measuring the corresponding electrical current generated.

Seismic response analysis of a 13-story steel moment-framed building in Alhambra, California

USGS Publications Warehouse

Rodgers, Janise E.; Sanli, Ahmet K.; Çelebi, Mehmet

2004-01-01

The seismic performance of steel moment-framed buildings has been of particular interest since brittle fractures were discovered at the beam-column connections of some frames following the M6.7 1994 Northridge earthquake. This report presents an investigation of the seismic behavior of an instrumented 13-story steel moment frame building located in the greater Los Angeles area of California. An extensive strong motion dataset, ambient vibration data, engineering drawings and earthquake damage reports are available for this building. The data are described and subsequently analyzed. The results of the analyses show that the building response is more complex than would be expected from its highly symmetrical geometry. The building's response is characterized by low damping in the fundamental mode, larger peak accelerations in the intermediate stories than at the roof, extended periods of vibration after the cessation of strong input shaking, beating in the response, and significant torsion during strong shaking at the top of the concrete piers which extend from the basement to the second floor. The analyses of the data and all damage detection methods employed except one method based on system identification indicate that the response of the structure was elastic in all recorded earthquakes. These findings are in general agreement with the results of intrusive inspections (meaning fireproofing and architectural finishes were removed) conducted on approximately 5 percent of the moment connections following the Northridge earthquake, which found no earthquake damage.

Feasibility study of the seismic reflection method in Amargosa Desert, Nye County, Nevada

USGS Publications Warehouse

Brocher, T.M.; Hart, P.E.; Carle, S.F.

1990-01-01

The seismic performance of steel moment-framed buildings has been of particular interest since brittle fractures were discovered at the beam-column connections of some frames following the M6.7 1994 Northridge earthquake. This report presents an investigation of the seismic behavior of an instrumented 13-story steel moment frame building located in the greater Los Angeles area of California. An extensive strong motion dataset, ambient vibration data, engineering drawings and earthquake damage reports are available for this building. The data are described and subsequently analyzed. The results of the analyses show that the building response is more complex than would be expected from its highly symmetrical geometry. The building's response is characterized by low damping in the fundamental mode, larger peak accelerations in the intermediate stories than at the roof, extended periods of vibration after the cessation of strong input shaking, beating in the response, and significant torsion during strong shaking at the top of the concrete piers which extend from the basement to the second floor. The analyses of the data and all damage detection methods employed except one method based on system identification indicate that the response of the structure was elastic in all recorded earthquakes. These findings are in general agreement with the results of intrusive inspections (meaning fireproofing and architectural finishes were removed) conducted on approximately 5 percent of the moment connections following the Northridge earthquake, which found no earthquake damage.

Association of Streptomyces community composition determined by PCR-denaturing gradient gel electrophoresis with indoor mold status

PubMed Central

Johansson, Elisabet; Reponen, Tiina; Meller, Jarek; Vesper, Stephen; Yadav, Jagjit

2014-01-01

Both Streptomyces species and mold species have previously been isolated from moisture-damaged building materials; however, an association between these two groups of microorganisms in indoor environments is not clear. In this study we used a culture-independent method, PCR denaturing gradient gel electrophoresis (PCR-DGGE) to investigate the composition of the Streptomyces community in house dust. Twenty-three dust samples each from two sets of homes categorized as high-mold and low-mold based on mold specific quantitative PCR-analysis were used in the study. Taxonomic identification of prominent bands was performed by cloning and sequencing. Associations between DGGE amplicon band intensities and home mold status were assessed using univariate analyses, as well as multivariate recursive partitioning (decision trees) to test the predictive value of combinations of bands intensities. In the final classification tree, a combination of two bands was significantly associated with mold status of the home (p = 0.001). The sequence corresponding to one of the bands in the final decision tree matched a group of Streptomyces species that included S. coelicolor and S. sampsonii, both of which have been isolated from moisture-damaged buildings previously. The closest match for the majority of sequences corresponding to a second band consisted of a group of Streptomyces species that included S. hygroscopicus, an important producer of antibiotics and immunosuppressors. Taken together, the study showed that DGGE can be a useful tool for identifying bacterial species that may be more prevalent in mold-damaged buildings. PMID:25331035

Gene silencing in Tribolium castaneum as a tool for the targeted identification of candidate RNAi targets in crop pests.

PubMed

Knorr, Eileen; Fishilevich, Elane; Tenbusch, Linda; Frey, Meghan L F; Rangasamy, Murugesan; Billion, Andre; Worden, Sarah E; Gandra, Premchand; Arora, Kanika; Lo, Wendy; Schulenberg, Greg; Valverde-Garcia, Pablo; Vilcinskas, Andreas; Narva, Kenneth E

2018-02-01

RNAi shows potential as an agricultural technology for insect control, yet, a relatively low number of robust lethal RNAi targets have been demonstrated to control insects of agricultural interest. In the current study, a selection of lethal RNAi target genes from the iBeetle (Tribolium castaneum) screen were used to demonstrate efficacy of orthologous targets in the economically important coleopteran pests Diabrotica virgifera virgifera and Meligethes aeneus. Transcript orthologs of 50 selected genes were analyzed in D. v. virgifera diet-based RNAi bioassays; 21 of these RNAi targets showed mortality and 36 showed growth inhibition. Low dose injection- and diet-based dsRNA assays in T. castaneum and D. v. virgifera, respectively, enabled the identification of the four highly potent RNAi target genes: Rop, dre4, ncm, and RpII140. Maize was genetically engineered to express dsRNA directed against these prioritized candidate target genes. T 0 plants expressing Rop, dre4, or RpII140 RNA hairpins showed protection from D. v. virgifera larval feeding damage. dsRNA targeting Rop, dre4, ncm, and RpII140 in M. aeneus also caused high levels of mortality both by injection and feeding. In summary, high throughput systems for model organisms can be successfully used to identify potent RNA targets for difficult-to-work with agricultural insect pests.

Role of isolated and clustered DNA damage and the post-irradiating repair process in the effects of heavy ion beam irradiation.

PubMed

Tokuyama, Yuka; Furusawa, Yoshiya; Ide, Hiroshi; Yasui, Akira; Terato, Hiroaki

2015-05-01

Clustered DNA damage is a specific type of DNA damage induced by ionizing radiation. Any type of ionizing radiation traverses the target DNA molecule as a beam, inducing damage along its track. Our previous study showed that clustered DNA damage yields decreased with increased linear energy transfer (LET), leading us to investigate the importance of clustered DNA damage in the biological effects of heavy ion beam radiation. In this study, we analyzed the yield of clustered base damage (comprising multiple base lesions) in cultured cells irradiated with various heavy ion beams, and investigated isolated base damage and the repair process in post-irradiation cultured cells. Chinese hamster ovary (CHO) cells were irradiated by carbon, silicon, argon and iron ion beams with LETs of 13, 55, 90 and 200 keV µm(-1), respectively. Agarose gel electrophoresis of the cells with enzymatic treatments indicated that clustered base damage yields decreased as the LET increased. The aldehyde reactive probe procedure showed that isolated base damage yields in the irradiated cells followed the same pattern. To analyze the cellular base damage process, clustered DNA damage repair was investigated using DNA repair mutant cells. DNA double-strand breaks accumulated in CHO mutant cells lacking Xrcc1 after irradiation, and the cell viability decreased. On the other hand, mouse embryonic fibroblast (Mef) cells lacking both Nth1 and Ogg1 became more resistant than the wild type Mef. Thus, clustered base damage seems to be involved in the expression of heavy ion beam biological effects via the repair process. © The Author 2015. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Robust uncertainty evaluation for system identification on distributed wireless platforms

NASA Astrophysics Data System (ADS)

Crinière, Antoine; Döhler, Michael; Le Cam, Vincent; Mevel, Laurent

2016-04-01

Health monitoring of civil structures by system identification procedures from automatic control is now accepted as a valid approach. These methods provide frequencies and modeshapes from the structure over time. For a continuous monitoring the excitation of a structure is usually ambient, thus unknown and assumed to be noise. Hence, all estimates from the vibration measurements are realizations of random variables with inherent uncertainty due to (unknown) process and measurement noise and finite data length. The underlying algorithms are usually running under Matlab under the assumption of large memory pool and considerable computational power. Even under these premises, computational and memory usage are heavy and not realistic for being embedded in on-site sensor platforms such as the PEGASE platform. Moreover, the current push for distributed wireless systems calls for algorithmic adaptation for lowering data exchanges and maximizing local processing. Finally, the recent breakthrough in system identification allows us to process both frequency information and its related uncertainty together from one and only one data sequence, at the expense of computational and memory explosion that require even more careful attention than before. The current approach will focus on presenting a system identification procedure called multi-setup subspace identification that allows to process both frequencies and their related variances from a set of interconnected wireless systems with all computation running locally within the limited memory pool of each system before being merged on a host supervisor. Careful attention will be given to data exchanges and I/O satisfying OGC standards, as well as minimizing memory footprints and maximizing computational efficiency. Those systems are built in a way of autonomous operations on field and could be later included in a wide distributed architecture such as the Cloud2SM project. The usefulness of these strategies is illustrated on data from a progressive damage action on a prestressed concrete bridge. References [1] E. Carden and P. Fanning. Vibration based condition monitoring: a review. Structural Health Monitoring, 3(4):355-377, 2004. [2] M. Döhler and L. Mevel. Efficient multi-order uncertainty computation for stochastic subspace identification. Mechanical Systems and Signal Processing, 38(2):346-366, 2013. [3] M.Döhler, L. Mevel. Modular subspace-based system identification from multi-setup measurements. IEEE Transactions on Automatic Control, 57(11):2951-2956, 2012. [4] M. Döhler, X.-B. Lam, and L. Mevel. Uncertainty quantification for modal parameters from stochastic subspace identification on multi-setup measurements. MechanicalSystems and Signal Processing, 36(2):562-581, 2013. [5] A Crinière, J Dumoulin, L Mevel, G Andrade-Barosso, M Simonin. The Cloud2SM Project.European Geosciences Union General Assembly (EGU2015), Apr 2015, Vienne, Austria. 2015.

An Early Warning System for Identification and Monitoring of Disturbances to Forest Ecosystems

NASA Astrophysics Data System (ADS)

Marshall, A. A.; Hoffman, F. M.; Kumar, J.; Hargrove, W. W.; Spruce, J.; Mills, R. T.

2011-12-01

Forest ecosystems are susceptible to damage due to threat events like wildfires, insect and disease attacks, extreme weather events, land use change, and long-term climate change. Early identification of such events is desired to devise and implement a protective response. The mission of the USDA Forest Service is to sustain the health, diversity, and productivity of the nation's forests. However, limited resources for aerial surveys and ground-based inspections are insufficient for monitoring the large areas covered by the U.S. forests. The USDA Forest Service, Oak Ridge National Laboratory, and NASA Stennis Space Center are developing an early warning system for the continuous tracking and long-term monitoring of disturbances and responses in forest ecosystems using high resolution satellite remote sensing data. Geospatiotemporal data mining techniques were developed and applied to normalized difference vegetation index (NDVI) products derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) MOD 13 data at 250 m resolution on eight day intervals. Representative phenologically similar regions, or phenoregions, were developed for the conterminous United States (CONUS) by applying a k-means clustering algorithm to the NDVI data spanning the full eight years of the MODIS record. Annual changes in the phenoregions were quantitatively analyzed to identify the significant changes in phenological behavior. This methodology was successfully applied for identification of various forest disturbance events, including wildfire, tree mortality due to Mountain Pine Beetle, and other insect infestation and diseases, as well as extreme events like storms and hurricanes in the United States. Where possible, the results were validated and quantitatively compared with aerial and ground-based survey data available from different agencies. This system was able to identify most of the disturbances reported by aerial and ground-based surveys, and it also identified affected areas that were not covered by any of the surveys. Analysis results and validation data will be presented.

Assessment of injuries to killer whales in Prince William Sound. Marine mammal study number 2. Exxon Valdez oil spill state/federal natural resource damage assessment final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dahlheim, M.E.; Matkin, C.O.

1993-12-01

Photo-identification studies of individual killer whales inhabiting Prince William Sound were collected from 1989-91 to determine the impact of the spill on whale abundance and distribution. Concurrent photo-identification studies were also conducted in Southeast Alaska to determine if PWS killer whales were displaced to other areas. Despite increased effort, the number of encounters with PWS killer whales appears to be decreasing. The authors assume, that the whales are dead from natural causes, a result of interactions with fisheries, from the spill, or a combination of these causes.

Phytophthora-ID.org: A sequence-based Phytophthora identification tool

Treesearch

N.J. Grünwald; F.N. Martin; M.M. Larsen; C.M. Sullivan; C.M. Press; M.D. Coffey; E.M. Hansen; J.L. Parke

2010-01-01

Contemporary species identification relies strongly on sequence-based identification, yet resources for identification of many fungal and oomycete pathogens are rare. We developed two web-based, searchable databases for rapid identification of Phytophthora spp. based on sequencing of the internal transcribed spacer (ITS) or the cytochrome oxidase...

Mapping Natech risk due to earthquakes using RAPID-N

NASA Astrophysics Data System (ADS)

Girgin, Serkan; Krausmann, Elisabeth

2013-04-01

Natural hazard-triggered technological accidents (so-called Natech accidents) at hazardous installations are an emerging risk with possibly serious consequences due to the potential for release of hazardous materials, fires or explosions. For the reduction of Natech risk, one of the highest priority needs is the identification of Natech-prone areas and the systematic assessment of Natech risks. With hardly any Natech risk maps existing within the EU the European Commission's Joint Research Centre has developed a Natech risk analysis and mapping tool called RAPID-N, that estimates the overall risk of natural-hazard impact to industrial installations and its possible consequences. The results are presented as risk summary reports and interactive risk maps which can be used for decision making. Currently, RAPID-N focuses on Natech risk due to earthquakes at industrial installations. However, it will be extended to also analyse and map Natech risk due to floods in the near future. The RAPID-N methodology is based on the estimation of on-site natural hazard parameters, use of fragility curves to determine damage probabilities of plant units for various damage states, and the calculation of spatial extent, severity, and probability of Natech events potentially triggered by the natural hazard. The methodology was implemented as a web-based risk assessment and mapping software tool which allows easy data entry, rapid local or regional risk assessment and mapping. RAPID-N features an innovative property estimation framework to calculate on-site natural hazard parameters, industrial plant and plant unit characteristics, and hazardous substance properties. Custom damage states and fragility curves can be defined for different types of plant units. Conditional relationships can be specified between damage states and Natech risk states, which describe probable Natech event scenarios. Natech consequences are assessed using a custom implementation of U.S. EPA's Risk Management Program (RMP) Guidance for Offsite Consequence Analysis methodology. This custom implementation is based on the property estimation framework and allows the easy modification of model parameters and the substitution of equations with alternatives. RAPID-N can be applied at different stages of the Natech risk management process: It allows on the one hand the analysis of hypothetical Natech scenarios to prevent or prepare for a Natech accident by supporting land-use and emergency planning. On the other hand, once a natural disaster occurs RAPID-N can be used for rapidly locating facilities with potential Natech accident damage based on actual natural-hazard information. This provides a means to warn the population in the vicinity of the facilities in a timely manner. This presentation will introduce the specific features of RAPID-N and show the use of the tool by application to a case-study area.

Study on validation method for femur finite element model under multiple loading conditions

NASA Astrophysics Data System (ADS)

Guan, Fengjiao; Zhang, Guanjun; Liu, Jie; Wang, Shujing; Luo, Xu

2018-03-01

Acquisition of accurate and reliable constitutive parameters related to bio-tissue materials was beneficial to improve biological fidelity of a Finite Element (FE) model and predict impact damages more effectively. In this paper, a femur FE model was established under multiple loading conditions with diverse impact positions. Then, based on sequential response surface method and genetic algorithms, the material parameters identification was transformed to a multi-response optimization problem. Finally, the simulation results successfully coincided with force-displacement curves obtained by numerous experiments. Thus, computational accuracy and efficiency of the entire inverse calculation process were enhanced. This method was able to effectively reduce the computation time in the inverse process of material parameters. Meanwhile, the material parameters obtained by the proposed method achieved higher accuracy.

Wireless system for explosion detection in underground structures

NASA Astrophysics Data System (ADS)

Chikhradze, M.; Bochorishvili, N.; Akhvlediani, I.; Kukhalashvili, D.; Kalichava, I.; Mataradze, E.

2009-06-01

Considering the growing threat of terrorist or accidental explosions in underground stations, underground highway and railway sections improvement of system for protecting people from explosions appears urgent. Current automatic protective devices with blast identification module and blast damping absorbers of various designs as their basic elements cannot be considered effective. Analysis revealed that low reliability of blast detection and delayed generation of start signal for the activation of an absorber are the major disadvantages of protective devices. Besides the transmission of trigger signal to an energy absorber through cable communication reduces the reliability of the operation of protective device due to a possible damage of electric wiring under blast or mechanical attack. This paper presents the outcomes of the studies conducted to select accurate criteria for blast identification and to design wireless system of activation of defensive device. The results of testing of blast detection methods (seismic, EMP, optical, on overpressure) showed that the proposed method, which implies constant monitoring of overpressure in terms of its reliability and response speed, best meets the requirements. Proposed wireless system for explosions identification and activation of protective device consists of transmitter and receiver modules. Transmitter module contains sensor and microprocessor equipped with blast identification software. Receiver module produces activation signal for operation of absorber. Tests were performed in the underground experimental base of Mining Institute. The time between the moment of receiving signal by the sensor and activation of absorber - 640 microsecond; distance between transmitter and receiver in direct tunnel - at least 150m; in tunnel with 900 bending - 50m. This research is sponsored by NATO's Public Diplomacy Division in the framework of "Science for Peace".

Semantic policy and adversarial modeling for cyber threat identification and avoidance

NASA Astrophysics Data System (ADS)

DeFrancesco, Anton; McQueary, Bruce

2009-05-01

Today's enterprise networks undergo a relentless barrage of attacks from foreign and domestic adversaries. These attacks may be perpetrated with little to no funding, but may wreck incalculable damage upon the enterprises security, network infrastructure, and services. As more services come online, systems that were once in isolation now provide information that may be combined dynamically with information from other systems to create new meaning on the fly. Security issues are compounded by the potential to aggregate individual pieces of information and infer knowledge at a higher classification than any of its constituent parts. To help alleviate these challenges, in this paper we introduce the notion of semantic policy and discuss how it's use is evolving from a robust approach to access control to preempting and combating attacks in the cyber domain, The introduction of semantic policy and adversarial modeling to network security aims to ask 'where is the network most vulnerable', 'how is the network being attacked', and 'why is the network being attacked'. The first aspect of our approach is integration of semantic policy into enterprise security to augment traditional network security with an overall awareness of policy access and violations. This awareness allows the semantic policy to look at the big picture - analyzing trends and identifying critical relations in system wide data access. The second aspect of our approach is to couple adversarial modeling with semantic policy to move beyond reactive security measures and into a proactive identification of system weaknesses and areas of vulnerability. By utilizing Bayesian-based methodologies, the enterprise wide meaning of data and semantic policy is applied to probability and high-level risk identification. This risk identification will help mitigate potential harm to enterprise networks by enabling resources to proactively isolate, lock-down, and secure systems that are most vulnerable.

Parametric and Non-Parametric Vibration-Based Structural Identification Under Earthquake Excitation

NASA Astrophysics Data System (ADS)

Pentaris, Fragkiskos P.; Fouskitakis, George N.

2014-05-01

The problem of modal identification in civil structures is of crucial importance, and thus has been receiving increasing attention in recent years. Vibration-based methods are quite promising as they are capable of identifying the structure's global characteristics, they are relatively easy to implement and they tend to be time effective and less expensive than most alternatives [1]. This paper focuses on the off-line structural/modal identification of civil (concrete) structures subjected to low-level earthquake excitations, under which, they remain within their linear operating regime. Earthquakes and their details are recorded and provided by the seismological network of Crete [2], which 'monitors' the broad region of south Hellenic arc, an active seismic region which functions as a natural laboratory for earthquake engineering of this kind. A sufficient number of seismic events are analyzed in order to reveal the modal characteristics of the structures under study, that consist of the two concrete buildings of the School of Applied Sciences, Technological Education Institute of Crete, located in Chania, Crete, Hellas. Both buildings are equipped with high-sensitivity and accuracy seismographs - providing acceleration measurements - established at the basement (structure's foundation) presently considered as the ground's acceleration (excitation) and at all levels (ground floor, 1st floor, 2nd floor and terrace). Further details regarding the instrumentation setup and data acquisition may be found in [3]. The present study invokes stochastic, both non-parametric (frequency-based) and parametric methods for structural/modal identification (natural frequencies and/or damping ratios). Non-parametric methods include Welch-based spectrum and Frequency response Function (FrF) estimation, while parametric methods, include AutoRegressive (AR), AutoRegressive with eXogeneous input (ARX) and Autoregressive Moving-Average with eXogeneous input (ARMAX) models[4, 5]. Preliminary results indicate that parametric methods are capable of sufficiently providing the structural/modal characteristics such as natural frequencies and damping ratios. The study also aims - at a further level of investigation - to provide a reliable statistically-based methodology for structural health monitoring after major seismic events which potentially cause harming consequences in structures. Acknowledgments This work was supported by the State Scholarships Foundation of Hellas. References [1] J. S. Sakellariou and S. D. Fassois, "Stochastic output error vibration-based damage detection and assessment in structures under earthquake excitation," Journal of Sound and Vibration, vol. 297, pp. 1048-1067, 2006. [2] G. Hloupis, I. Papadopoulos, J. P. Makris, and F. Vallianatos, "The South Aegean seismological network - HSNC," Adv. Geosci., vol. 34, pp. 15-21, 2013. [3] F. P. Pentaris, J. Stonham, and J. P. Makris, "A review of the state-of-the-art of wireless SHM systems and an experimental set-up towards an improved design," presented at the EUROCON, 2013 IEEE, Zagreb, 2013. [4] S. D. Fassois, "Parametric Identification of Vibrating Structures," in Encyclopedia of Vibration, S. G. Braun, D. J. Ewins, and S. S. Rao, Eds., ed London: Academic Press, London, 2001. [5] S. D. Fassois and J. S. Sakellariou, "Time-series methods for fault detection and identification in vibrating structures," Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, vol. 365, pp. 411-448, February 15 2007.

Management of established pressure ulcer infections in spinal cord injury patients.

PubMed

Dinh, A; Bouchand, F; Davido, B; Duran, C; Denys, P; Lortat-Jacob, A; Rottman, M; Salomon, J; Bernard, L

2018-06-21

Pressure ulcers are frequently observed in spinal cord injury (SCI) patients. They can be life-threatening and are a major medico-economic burden. Despite their frequency, their pathophysiology and optimal management are still poorly understood. Most available data comes from non-comparative studies, especially in terms of antimicrobial use. We performed a critical review of the literature and opinions of infectious disease specialists based in a French expert center for this disease. We mainly focused on antimicrobial treatments prescribed in this situation. These infections are usually clinically diagnosed. Microbiological samples are not the gold standard for this assessment. Furthermore, reliable microbiological identification is a major challenge but should help select antimicrobial treatment. Imaging technique could be helpful but cannot replace the physical examination. The choice of antimicrobials must consider the potential ecological collateral damages in this vulnerable population. Antimicrobial therapy should be as short as possible, adapted to the microbiological identification, and must have suitable bioavailability. Management of infected pressure ulcers is a major concern in disabled patients already highly exposed to antimicrobial treatment and multidrug-resistant organisms colonization. Extensive data is required. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Improved identification of cranial nerves using paired-agent imaging: topical staining protocol optimization through experimentation and simulation

NASA Astrophysics Data System (ADS)

Torres, Veronica C.; Wilson, Todd; Staneviciute, Austeja; Byrne, Richard W.; Tichauer, Kenneth M.

2018-03-01

Skull base tumors are particularly difficult to visualize and access for surgeons because of the crowded environment and close proximity of vital structures, such as cranial nerves. As a result, accidental nerve damage is a significant concern and the likelihood of tumor recurrence is increased because of more conservative resections that attempt to avoid injuring these structures. In this study, a paired-agent imaging method with direct administration of fluorophores is applied to enhance cranial nerve identification. Here, a control imaging agent (ICG) accounts for non-specific uptake of the nerve-targeting agent (Oxazine 4), and ratiometric data analysis is employed to approximate binding potential (BP, a surrogate of targeted biomolecule concentration). For clinical relevance, animal experiments and simulations were conducted to identify parameters for an optimized stain and rinse protocol using the developed paired-agent method. Numerical methods were used to model the diffusive and kinetic behavior of the imaging agents in tissue, and simulation results revealed that there are various combinations of stain time and rinse number that provide improved contrast of cranial nerves, as suggested by optimal measures of BP and contrast-to-noise ratio.

Dissociations among functional subsystems governing melody recognition after right-hemisphere damage.

PubMed

Steinke, W R; Cuddy, L L; Jakobson, L S

2001-07-01

This study describes an amateur musician, KB, who became amusic following a right-hemisphere stroke. A series of assessments conducted post-stroke revealed that KB functioned in the normal range for most verbal skills. However, compared with controls matched in age and music training, KB showed severe loss of pitch and rhythmic processing abilities. His ability to recognise and identify familiar instrumental melodies was also lost. Despite these deficits, KB performed remarkably well when asked to recognise and identify familiar song melodies presented without accompanying lyrics. This dissociation between the ability to recognise/identify song vs. instrumental melodies was replicated across different sets of musical materials, including newly learned melodies. Analyses of the acoustical and musical features of song and instrumental melodies discounted an explanation of the dissociation based on these features alone. Rather, the results suggest a functional dissociation resulting from a focal brain lesion. We propose that, in the case of song melodies, there remains sufficient activation in KB's melody analysis system to coactivate an intact representation of both associative information and the lyrics in the speech lexicon, making recognition and identification possible. In the case of instrumental melodies, no such associative processes exist; thus recognition and identification do not occur.

Idiopathic inflammatory myositis.

PubMed

Tieu, Joanna; Lundberg, Ingrid E; Limaye, Vidya

2016-02-01

Knowledge on idiopathic inflammatory myopathy (IIM) has evolved with the identification of myositis-associated and myositis-specific antibodies, development of histopathological classification and the recognition of how these correlate with clinical phenotype and response to therapy. In this paper, we outline key advances in diagnosis and histopathology, including the more recent identification of antibodies associated with immune-mediated necrotising myopathy (IMNM) and inclusion body myositis (IBM). Ongoing longitudinal observational cohorts allow further classification of these patients with IIM, their predicted clinical course and response to specific therapies. Registries have been developed worldwide for this purpose. A challenging aspect in IIM, a multisystem disease with multiple clinical subtypes, has been defining disease status and clinically relevant improvement. Tools for assessing activity and damage are now recognised to be important in determining disease activity and guiding therapeutic decision-making. The International Myositis Assessment and Clinical Studies (IMACS) group has developed such tools for use in research and clinical settings. There is limited evidence for specific treatment strategies in IIM. With significant development in the understanding of IIM and improved classification, longitudinal observational cohorts and trials using validated outcome measures are necessary, to provide important information for evidence-based care in the clinical setting. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Smoothly varying in-plane stiffness heterogeneity evaluated under uniaxial tensile stress

Treesearch

J.M. Considine; F. Pierron; K.T. Turner; P. Lava; X. Tang

2017-01-01

Identification of spatially varying stiffness is a challenging, but important, research topic in the mechanics of materials and can provide the necessary information for material suitability, damage, and process control, especially for high‐value applications. One homogeneous and 3 heterogeneous virtual field method (VFM) formulations were used to create a methodology...

Field guide to diseases & insects of the Rocky Mountain Region

Treesearch

Forest Health Protection Rocky Mountain Region

2010-01-01

This field guide is a forest management tool for field identification of biotic and abiotic agents that damage native trees in Colorado, Kansas, Nebraska, South Dakota, and Wyoming, which constitute the USDA Forest Service's Rocky Mountain Region. The guide focuses only on tree diseases and forest insects that have significant economic, ecological, and/ or...

Fusion of Remote Sensing and Non-Authoritative Data for Flood Disaster and Transportation Infrastructure Assessment

ERIC Educational Resources Information Center

Schnebele, Emily K.

2013-01-01

Flooding is the most frequently occurring natural hazard on Earth; with catastrophic, large scale floods causing immense damage to people, property, and the environment. Over the past 20 years, remote sensing has become the standard technique for flood identification because of its ability to offer synoptic coverage. Unfortunately, remote sensing…

Identification of Two Haplotypes of Cytochrome Oxidase Sub-unit II (COII) Gene of the Formosan Subterranean Termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) in South Mississippi

USDA-ARS?s Scientific Manuscript database

The Formosan subterranear termite, Coptotermes formosanus was accidentally introduced to the United States from Asia. The introduction of the pest has brought significant economic damage. During the past decade, Mississippi has become a significantly infested state, partially due to the proximity to...

A Review of Spectral Methods for Variable Amplitude Fatigue Prediction and New Results

NASA Technical Reports Server (NTRS)

Larsen, Curtis E.; Irvine, Tom

2013-01-01

A comprehensive review of the available methods for estimating fatigue damage from variable amplitude loading is presented. The dependence of fatigue damage accumulation on power spectral density (psd) is investigated for random processes relevant to real structures such as in offshore or aerospace applications. Beginning with the Rayleigh (or narrow band) approximation, attempts at improved approximations or corrections to the Rayleigh approximation are examined by comparison to rainflow analysis of time histories simulated from psd functions representative of simple theoretical and real world applications. Spectral methods investigated include corrections by Wirsching and Light, Ortiz and Chen, the Dirlik formula, and the Single-Moment method, among other more recent proposed methods. Good agreement is obtained between the spectral methods and the time-domain rainflow identification for most cases, with some limitations. Guidelines are given for using the several spectral methods to increase confidence in the damage estimate.

A gradient enhanced plasticity-damage microplane model for concrete

NASA Astrophysics Data System (ADS)

Zreid, Imadeddin; Kaliske, Michael

2018-03-01

Computational modeling of concrete poses two main types of challenges. The first is the mathematical description of local response for such a heterogeneous material under all stress states, and the second is the stability and efficiency of the numerical implementation in finite element codes. The paper at hand presents a comprehensive approach addressing both issues. Adopting the microplane theory, a combined plasticity-damage model is formulated and regularized by an implicit gradient enhancement. The plasticity part introduces a new microplane smooth 3-surface cap yield function, which provides a stable numerical solution within an implicit finite element algorithm. The damage part utilizes a split, which can describe the transition of loading between tension and compression. Regularization of the model by the implicit gradient approach eliminates the mesh sensitivity and numerical instabilities. Identification methods for model parameters are proposed and several numerical examples of plain and reinforced concrete are carried out for illustration.

Using transcranial magnetic stimulation of the undamaged brain to identify lesion sites that predict language outcome after stroke

PubMed Central

Lorca-Puls, Diego L.; Gajardo-Vidal, Andrea; Seghier, Mohamed L.; Leff, Alexander P.; Sethi, Varun; Prejawa, Susan; Hope, Thomas M. H.; Devlin, Joseph T.

2017-01-01

Abstract Transcranial magnetic stimulation focused on either the left anterior supramarginal gyrus or opercular part of the left inferior frontal gyrus has been reported to transiently impair the ability to perform phonological more than semantic tasks. Here we tested whether phonological processing abilities were also impaired following lesions to these regions in right-handed, English speaking adults, who were investigated at least 1 year after a left-hemisphere stroke. When our regions of interest were limited to 0.5 cm3 of grey matter centred around sites that had been identified with transcranial magnetic stimulation-based functional localization, phonological impairments were observed in 74% (40/54) of patients with damage to the regions and 21% (21/100) of patients sparing these regions. This classification accuracy was better than that observed when using regions of interest centred on activation sites in previous functional magnetic resonance imaging studies of phonological processing, or transcranial magnetic stimulation sites that did not use functional localization. New regions of interest were generated by redefining the borders of each of the transcranial magnetic stimulation sites to include areas that were consistently damaged in the patients with phonological impairments. This increased the incidence of phonological impairments in the presence of damage to 85% (46/54) and also reduced the incidence of phonological impairments in the absence of damage to 15% (15/100). The difference in phonological processing abilities between those with and without damage to these ‘transcranial magnetic stimulation-guided’ regions remained highly significant even after controlling for the effect of lesion size. The classification accuracy of the transcranial magnetic stimulation-guided regions was validated in a second sample of 108 patients and found to be better than that for (i) functional magnetic resonance imaging-guided regions; (ii) a region identified from an unguided lesion overlap map; and (iii) a region identified from voxel-based lesion-symptom mapping. Finally, consistent with prior findings from functional imaging and transcranial magnetic stimulation in healthy participants, we show how damage to our transcranial magnetic stimulation-guided regions affected performance on phonologically more than semantically demanding tasks. The observation that phonological processing abilities were impaired years after the stroke, suggests that other brain regions were not able to fully compensate for the contribution that the transcranial magnetic stimulation-guided regions make to language tasks. More generally, our novel transcranial magnetic stimulation-guided lesion-deficit mapping approach shows how non-invasive stimulation of the healthy brain can be used to guide the identification of regions where brain damage is likely to cause persistent behavioural effects. PMID:28430974

Using transcranial magnetic stimulation of the undamaged brain to identify lesion sites that predict language outcome after stroke.

PubMed

Lorca-Puls, Diego L; Gajardo-Vidal, Andrea; Seghier, Mohamed L; Leff, Alexander P; Sethi, Varun; Prejawa, Susan; Hope, Thomas M H; Devlin, Joseph T; Price, Cathy J

2017-06-01

Transcranial magnetic stimulation focused on either the left anterior supramarginal gyrus or opercular part of the left inferior frontal gyrus has been reported to transiently impair the ability to perform phonological more than semantic tasks. Here we tested whether phonological processing abilities were also impaired following lesions to these regions in right-handed, English speaking adults, who were investigated at least 1 year after a left-hemisphere stroke. When our regions of interest were limited to 0.5 cm3 of grey matter centred around sites that had been identified with transcranial magnetic stimulation-based functional localization, phonological impairments were observed in 74% (40/54) of patients with damage to the regions and 21% (21/100) of patients sparing these regions. This classification accuracy was better than that observed when using regions of interest centred on activation sites in previous functional magnetic resonance imaging studies of phonological processing, or transcranial magnetic stimulation sites that did not use functional localization. New regions of interest were generated by redefining the borders of each of the transcranial magnetic stimulation sites to include areas that were consistently damaged in the patients with phonological impairments. This increased the incidence of phonological impairments in the presence of damage to 85% (46/54) and also reduced the incidence of phonological impairments in the absence of damage to 15% (15/100). The difference in phonological processing abilities between those with and without damage to these 'transcranial magnetic stimulation-guided' regions remained highly significant even after controlling for the effect of lesion size. The classification accuracy of the transcranial magnetic stimulation-guided regions was validated in a second sample of 108 patients and found to be better than that for (i) functional magnetic resonance imaging-guided regions; (ii) a region identified from an unguided lesion overlap map; and (iii) a region identified from voxel-based lesion-symptom mapping. Finally, consistent with prior findings from functional imaging and transcranial magnetic stimulation in healthy participants, we show how damage to our transcranial magnetic stimulation-guided regions affected performance on phonologically more than semantically demanding tasks. The observation that phonological processing abilities were impaired years after the stroke, suggests that other brain regions were not able to fully compensate for the contribution that the transcranial magnetic stimulation-guided regions make to language tasks. More generally, our novel transcranial magnetic stimulation-guided lesion-deficit mapping approach shows how non-invasive stimulation of the healthy brain can be used to guide the identification of regions where brain damage is likely to cause persistent behavioural effects. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain.

Magnetic Flux Leakage Sensing and Artificial Neural Network Pattern Recognition-Based Automated Damage Detection and Quantification for Wire Rope Non-Destructive Evaluation.

PubMed

Kim, Ju-Won; Park, Seunghee

2018-01-02

In this study, a magnetic flux leakage (MFL) method, known to be a suitable non-destructive evaluation (NDE) method for continuum ferromagnetic structures, was used to detect local damage when inspecting steel wire ropes. To demonstrate the proposed damage detection method through experiments, a multi-channel MFL sensor head was fabricated using a Hall sensor array and magnetic yokes to adapt to the wire rope. To prepare the damaged wire-rope specimens, several different amounts of artificial damages were inflicted on wire ropes. The MFL sensor head was used to scan the damaged specimens to measure the magnetic flux signals. After obtaining the signals, a series of signal processing steps, including the enveloping process based on the Hilbert transform (HT), was performed to better recognize the MFL signals by reducing the unexpected noise. The enveloped signals were then analyzed for objective damage detection by comparing them with a threshold that was established based on the generalized extreme value (GEV) distribution. The detected MFL signals that exceed the threshold were analyzed quantitatively by extracting the magnetic features from the MFL signals. To improve the quantitative analysis, damage indexes based on the relationship between the enveloped MFL signal and the threshold value were also utilized, along with a general damage index for the MFL method. The detected MFL signals for each damage type were quantified by using the proposed damage indexes and the general damage indexes for the MFL method. Finally, an artificial neural network (ANN) based multi-stage pattern recognition method using extracted multi-scale damage indexes was implemented to automatically estimate the severity of the damage. To analyze the reliability of the MFL-based automated wire rope NDE method, the accuracy and reliability were evaluated by comparing the repeatedly estimated damage size and the actual damage size.

Nanotechnology and MEMS-based systems for civil infrastructure safety and security: Opportunities and challenges

NASA Astrophysics Data System (ADS)

Robinson, Nidia; Saafi, Mohamed

2006-03-01

Critical civil infrastructure systems such as bridges, high rises, dams, nuclear power plants and pipelines present a major investment and the health of the United States' economy and the lifestyle of its citizens both depend on their safety and security. The challenge for engineers is to maintain the safety and security of these large structures in the face of terrorism threats, natural disasters and long-term deterioration, as well as to meet the demands of emergency response times. With the significant negative impact that these threats can have on the structural environment, health monitoring of civil infrastructure holds promise as a way to provide information for near real-time condition assessment of the structure's safety and security. This information can be used to assess the integrity of the structure for post-earthquake and terrorist attacks rescue and recovery, and to safely and rapidly remove the debris and to temporary shore specific structural elements. This information can also be used for identification of incipient damage in structures experiencing long-term deterioration. However, one of the major obstacles preventing sensor-based monitoring is the lack of reliable, easy-to-install, cost-effective and harsh environment resistant sensors that can be densely embedded into large-scale civil infrastructure systems. Nanotechnology and MEMS-based systems which have matured in recent years represent an innovative solution to current damage detection systems, leading to wireless, inexpensive, durable, compact, and high-density information collection. In this paper, ongoing research activities at Alabama A&M University (AAMU) Center for Transportation Infrastructure Safety and Security on the application of nanotechnology and MEMS to Civil Infrastructure for health monitoring will presented. To date, research showed that nanotechnology and MEMS-based systems can be used to wirelessly detect and monitor different damage mechanisms in concrete structures as well as monitor critical structures' stability during floods and barge impact. However, some technical issues that needs to be addressed before full implementation of these new systems and will also be discussed in this paper.

Flood damage curves for consistent global risk assessments

NASA Astrophysics Data System (ADS)

de Moel, Hans; Huizinga, Jan; Szewczyk, Wojtek

2016-04-01

Assessing potential damage of flood events is an important component in flood risk management. Determining direct flood damage is commonly done using depth-damage curves, which denote the flood damage that would occur at specific water depths per asset or land-use class. Many countries around the world have developed flood damage models using such curves which are based on analysis of past flood events and/or on expert judgement. However, such damage curves are not available for all regions, which hampers damage assessments in those regions. Moreover, due to different methodologies employed for various damage models in different countries, damage assessments cannot be directly compared with each other, obstructing also supra-national flood damage assessments. To address these problems, a globally consistent dataset of depth-damage curves has been developed. This dataset contains damage curves depicting percent of damage as a function of water depth as well as maximum damage values for a variety of assets and land use classes (i.e. residential, commercial, agriculture). Based on an extensive literature survey concave damage curves have been developed for each continent, while differentiation in flood damage between countries is established by determining maximum damage values at the country scale. These maximum damage values are based on construction cost surveys from multinational construction companies, which provide a coherent set of detailed building cost data across dozens of countries. A consistent set of maximum flood damage values for all countries was computed using statistical regressions with socio-economic World Development Indicators from the World Bank. Further, based on insights from the literature survey, guidance is also given on how the damage curves and maximum damage values can be adjusted for specific local circumstances, such as urban vs. rural locations, use of specific building material, etc. This dataset can be used for consistent supra-national scale flood damage assessments, and guide assessment in countries where no damage model is currently available.

An experimental validation of a statistical-based damage detection approach.

DOT National Transportation Integrated Search

2011-01-01

In this work, a previously-developed, statistical-based, damage-detection approach was validated for its ability to : autonomously detect damage in bridges. The damage-detection approach uses statistical differences in the actual and : predicted beha...

Wavelet subspace decomposition of thermal infrared images for defect detection in artworks

NASA Astrophysics Data System (ADS)

Ahmad, M. Z.; Khan, A. A.; Mezghani, S.; Perrin, E.; Mouhoubi, K.; Bodnar, J. L.; Vrabie, V.

2016-07-01

Health of ancient artworks must be routinely monitored for their adequate preservation. Faults in these artworks may develop over time and must be identified as precisely as possible. The classical acoustic testing techniques, being invasive, risk causing permanent damage during periodic inspections. Infrared thermometry offers a promising solution to map faults in artworks. It involves heating the artwork and recording its thermal response using infrared camera. A novel strategy based on pseudo-random binary excitation principle is used in this work to suppress the risks associated with prolonged heating. The objective of this work is to develop an automatic scheme for detecting faults in the captured images. An efficient scheme based on wavelet based subspace decomposition is developed which favors identification of, the otherwise invisible, weaker faults. Two major problems addressed in this work are the selection of the optimal wavelet basis and the subspace level selection. A novel criterion based on regional mutual information is proposed for the latter. The approach is successfully tested on a laboratory based sample as well as real artworks. A new contrast enhancement metric is developed to demonstrate the quantitative efficiency of the algorithm. The algorithm is successfully deployed for both laboratory based and real artworks.

Experimental Study on Damage Detection in Timber Specimens Based on an Electromechanical Impedance Technique and RMSD-Based Mahalanobis Distance

PubMed Central

Wang, Dansheng; Wang, Qinghua; Wang, Hao; Zhu, Hongping

2016-01-01

In the electromechanical impedance (EMI) method, the PZT patch performs the functions of both sensor and exciter. Due to the high frequency actuation and non-model based characteristics, the EMI method can be utilized to detect incipient structural damage. In recent years EMI techniques have been widely applied to monitor the health status of concrete and steel materials, however, studies on application to timber are limited. This paper will explore the feasibility of using the EMI technique for damage detection in timber specimens. In addition, the conventional damage index, namely root mean square deviation (RMSD) is employed to evaluate the level of damage. On that basis, a new damage index, Mahalanobis distance based on RMSD, is proposed to evaluate the damage severity of timber specimens. Experimental studies are implemented to detect notch and hole damage in the timber specimens. Experimental results verify the availability and robustness of the proposed damage index and its superiority over the RMSD indexes. PMID:27782088