Porosity and Inclusion Detection in CFRP by Infrared Thermography

The ever wide use of composite materials in the aeronautical industry has evidenced the need for development of ever more effective nondestructive evaluation methodologies in order to reduce rejected parts and to optimize production costs. Infrared thermography has been recently enclosed amongst the standardized non destructive testing techniques, but its usefulness needs still complete assessment since it can be employed in several different arrangements and for many purposes. In this work, the possibility to detect slag inclusions and porosity is analyzed with both lock-in themography and pulse thermography in the transmission mode. To this end, carbon-fiber-peinforced polymers different specimens are specifically fabricated of several different stacking sequences and with embedded slag inclusions and porosity percentages. As main results, both of the techniques are found definitely able to reveal the presence of the defects above mentioned. Moreover, these techniques could be considered complementary in order to better characterize the nature of the detected defects

On the use of lock-in thermography to monitor delamination growth in composite panels under compression

Abstract The success of composites in automotive, aerospace, and naval applications is mainly related to their aptitude to be tailored to obtain a final product that perfectly fulfills the design requirements. However, during both manufacturing processes and maintenance, some flaws, like delaminations (which may escape simple visual inspection), may be induced in composite structures. The presence of delaminations is of major concern for the load-carrying capability of carbon fiber-reinforced polymer panels. Indeed, delaminations can strongly affect the structural strength and may grow under in-service loads, leading sometimes to catastrophic failures. The aim of this work is to explore the use of lock-in thermography for the monitoring of delamination propagation in composite structures when subjected to generic multiaxial loading conditions. A stiffened composite panel with an embedded skin delamination subjected to compressive loading was taken as a benchmark to assess experimentally the effectiveness of lock-in thermography for monitoring the delamination propagation in situ during the compressive mechanical test. The delamination size as a function of the applied load, observed by lock-in thermography during the execution of the compressive test, was used to validate the results of preliminary numerical computations

Anomaly Detection in Hyperspectral Imagery: Comparison of Methods Using Diurnal and Seasonal Data

The use of hyperspectral imaging is a fast growing field with many applications in the civilian, commercial and military sectors. Hyperspectral images are typically composed of many spectral bands in the visible and infrared regions of the electromagnetic spectrum and have the potential to deliver a great deal of information about a remotely sensed scene. One area of interest regarding hyperspectral images is anomaly detection, or the ability to find spectral outliers within a complex background in a scene with no a priori information about the scene or its specific contents. Anomaly detectors typically operate by creating a statistical background model of a hyperspectral image and measuring anomalies as image pixels that do not conform properly to that given model. In this study we compare the performance over diurnal and seasonal changes for several different anomaly detection methods found in the literature and a new anomaly detector that we refer to as the fuzzy cluster-based anomaly detector. Here we also compare the performance of several anomaly-based change detection algorithms. Our results indicate that all anomaly detectors tested in this experimentation exhibit strong performance under optimum illumination and environmental conditions. However, our results point toward a significant performance advantage for cluster-based anomaly detectors in the presence of adverse environmental conditions

Routinely frozen biopsies of human skeletal muscle are suitable for morphological and immunocytochemical analyses at transmission electron microscopy

The aim of the present investigation was to evaluate whether routinely frozen biopsies of human skeletal muscle may be suitable for morphological and immunocytochemical analyses at transmission electron microscopy. The fixation/embedding protocols we successfully used for decades to process fresh mammalian tissues have been applied to frozen muscle biopsies stored for one to four years in liquid nitrogen. After 2.5% glutaraldehyde -2% paraformaldehyde - 1% OsO4 fixation and embedding in epoxy resin, the ultrastructural morphology of myofibres and satellite cells as well as of their organelles and inclusions proved to be well preserved. As expected, after 4% paraformaldehyde - 0.5% glutaraldehyde fixation and embedding in LR White resin, the morphology of membrane-bounded organelles was relatively poor, although myofibrillar and sarcomeric organization was still recognizable. On the contrary, the myonuclei were excellently preserved and, after conventional staining with uranyl acetate, showed an EDTA-like effect, i.e. the bleaching of condensed chromatin, which allows the visualization of RNP-containing structures. These samples proved to be suitable for immunocytochemical analyses of both cytoskeletal and nuclear components, whereas the poor mitochondrial preservation makes unreliable any in situ investigation on these organelles

The Effects of an Equine Assisted Learning Supervision Intervention on Counselors’-in-Training Performance Anxiety, Counseling Self-Efficacy, and Supervisory Working Alliance

Due to the complexity of the counseling process, counselors-in-training often experience performance anxiety when entering the counseling profession. Research shows that higher counseling self-efficacy (the belief in oneself to perform counseling skills successfully) helps decrease performance anxiety. Further, a strong supervisory working alliance is the most effective intervention to increase counseling-self-efficacy. However, there are barriers to building a strong supervisory working alliance including high performance anxiety and low counseling self-efficacy as well as the dual nature of the supervisor's role as mentor and evaluator. This study introduces an equine assisted learning supervision intervention for counselors-in-training. This experiential learning intervention provides an opportunity for counselor self-exploration and growth in a non-evaluative, nonjudgmental, novel situation. The population of interest was counselors-in-training enrolled in CACREP counseling programs. The purposive sample included 20 students enrolled in a theories counseling course or a practicum skills course. The study used a quasi-experimental design where participants completed a Demographic Questionnaire, the Counseling Self-Estimate Inventory, the State-Trait Anxiety Inventory, and the Supervisory Working Alliance-Trainee Form. Participants were randomly selected to be in a treatment group, which received a one hour individual equine assisted learning supervision intervention or in the control group, which received class as usual. Six research questions examined the main effect of the EAL-S intervention on counseling self-efficacy, the main effect of the EAL-S intervention on performance anxiety, the relationship between counseling self-efficacy and performance anxiety, the correlation of the quality of supervisory working alliance with counseling self-efficacy, the correlation of the quality of the supervisory working alliance with performance anxiety, and the correlation of the supervisory working alliance with the effectiveness of the EAL-S intervention. A split-plot MANOVA was performed to analyze the first two questions and revealed a significant main effect of the EAL-S intervention on counseling self-efficacy. Non-significance was found in the main effect of the EAL-S intervention on performance anxiety. Pearson Product Moment Correlations were performed for the remaining questions. A significant positive correlation was found between counseling self-efficacy and performance anxiety. No significance was found in the correlation of the quality of the supervisory working alliance with counseling self-efficacy, performance anxiety, or the effectiveness of the EAL-S intervention. Findings support that a one hour EAL-S intervention can improve counselors'-in-training counseling self-efficacy and improve their tolerance for performance anxiety. These results have implications for counselors-in-training, supervisors, and counselor educators

Cultured myoblasts from patients affected by myotonic dystrophy type 2 exhibit senescence-related features: ultrastructural evidence

Myotonic dystrophy type 2 (DM2) is an autosomal dominant disorder caused by the expansion of the tetranucleotidic repeat (CCTG)n in the first intron of the Zinc Finger Protein-9 gene. In DM2 tissues, the expanded mutant transcripts accumulate in nuclear focal aggregates where splicing factors are sequestered, thus affecting mRNA processing. Interestingly, the ultrastructural alterations in the splicing machinery observed in the myonuclei of DM2 skeletal muscles are reminiscent of the nuclear changes occurring in age-related muscle atrophy. Here, we investigated in vitro structural and functional features of satellite cell-derived myoblasts from biceps brachii, in the attempt to investigate cell senescence indices in DM2 patients by ultrastructural cytochemistry. We observed that in satellite cell-derived DM2 myoblasts, cell-senescence alterations such as cytoplasmic vacuolization, reduction of the proteosynthetic apparatus, accumulation of heterochromatin and impairment of the pre-mRNA maturation pathways occur earlier than in myoblasts from healthy patients. These results, together with preliminary in vitro observations on the early onset of defective structural features in DM2 myoblast derived-myotubes, suggest that the regeneration capability of DM2 satellite cells may be impaired, thus contributing to the muscular dystrophy in DM2 patients

Infrared Thermography to an Aluminium Foam Sandwich Structure Subjected to Low Velocity Impact Tests

Abstract This work is the straightforward continuation of previous ones in which vibro-acoustic characteristics of AFS panels were investigated both numerically and experimentally. Herein, the use of infrared thermography (IRT) is exploited to investigate impact damaging of an aluminium foam sandwich panel by monitoring its surface, opposite to the impact, during a low velocity impact test, which is performed with a modified Charpy pendulum. Thermal images, acquired in time sequence during the impact by the infrared camera, are post-processed to get information useful for understanding absorption capabilities and impact damaging mechanisms of this kind of structure

Food intake and nutritional status in stable hemodialysis patients.

evaluate changes of actual dietary nutrient intake in 94 stable hemodialysis patients in respect to 52 normal subjects and guideline recommendations, and to assess the prevalence of signs of malnutrition. Energy and nutrients intake assessment was obtained by a three-day period food recall. Anthropometric and biochemical parameters of nutrition, bioelectric impedance vector analysis, and subjective global assessment (SGA) have been performed to assess nutritional status. SGA-B was scored in 5% of the patients. Body mass index < 20 Kg/m2, serum albumin <35 g/L, nPNA < 1.0 g/Kg, and phase angle <4.0° were detected in 16.3%, 16%, 23%, and 8.0 % of patients, respectively. HD patients showed a lower energy and protein intake in respect to controls, but no difference occurred when normalized per ideal body weight (29.3 ± 8.4 vs. 29.5 ± 8.4 Kcal/Kg i.b.w./d and 1.08 ± 0.35 vs. 1.12 ± 0.32 Kcal/Kg i.b.w. /d, respectively). Age was the only parameter that inversely correlates with energy (r = −0.35, p < 0.001) and protein intake (r = −0.34, p < 0.001). This study shows that in stable dialysis patients, abnormalities of nutritional parameters are less prevalent than expected by analysis of dietary food intake. Age is the best predictor of energy and protein intake in the dialysis patients who ate less than normal people, but no difference emerged when energy and protein intakes were normalized for body weight. These results recall the attention for individual dietetic counseling in HD patients, and also for a critical re-evaluation of their dietary protein and energy requirements

Learning Set Representations for LWIR In-Scene Atmospheric Compensation

Atmospheric compensation of long-wave infrared (LWIR) hyperspectral imagery is investigated in this article using set representations learned by a neural network. This approach relies on synthetic at-sensor radiance data derived from collected radiosondes and a diverse database of measured emissivity spectra sampled at a range of surface temperatures. The network loss function relies on LWIR radiative transfer equations to update model parameters. Atmospheric predictions are made on a set of diverse pixels extracted from the scene, without knowledge of blackbody pixels or pixel temperatures. The network architecture utilizes permutation-invariant layers to predict a set representation, similar to the work performed in point cloud classification. When applied to collected hyperspectral image data, this method shows comparable performance to Fast Line-of-Sight Atmospheric Analysis of Hypercubes-Infrared (FLAASH-IR), using an auto- mated pixel selection approach. Additionally, inference time is significantly reduced compared to FLAASH-IR with predictions made on average in 0.24 s on a 128 pixel by 5000 pixel data cube using a mobile graphics card. This computational speed-up on a low-power platform results in an autonomous atmospheric compensation method effective for real-time, onboard use, while only requiring a diversity of materials in the scene