Advanced Formation Fluid Evaluation While Drilling with a New Heavy Gas Detector

In this paper, a chromatograph which exploits the benefits of FID technology optimized for the high resolution detection of heavier hydrocarbon gas components is described. The components analyzed span from n-hexane to toluene. Flame Ionization Detector (FID) technology is not new to gas detection on the field, however it had never been applied to the detection of gases heavier than n-pentane. The instrumentation has been installed and run on a number of wells in different fields and countries, and it has operated as a complement of an advanced surface logging system for a period of two years. Unlike other technologies presently utilized for this scope, this system reduces dedicated equipment and personnel to a minimum. The results presented show the clear identification of formation fluid contacts with higher accuracy than standard light gas detectors, the recognition of contaminants within the drilling fluid, and the practicality of operating an advanced gas detection system with minimal operational and logistic footprint. Some of the indications obtained challenge common beliefs about gas detection: consistent extraction of heavy hydrocarbon gases from the drilling fluid is possible at relatively low temperatures, provided that the entire gas extraction system is rigorously controlled in terms of gas sample pressure, flow, and temperature. Furthermore, gas data analysis can yield indications on the fluid composition even when the gases analyzed are in extremely low quantity. The system utilizes known technologies, developed and optimized to obtain new results. The system supports formation evaluation when LWD or wireline can be inconclusive, in the presence of a low porosity pay or fresh water. It can also guide and optimize the MDT testing program. Furthermore, the system takes into account the constraints of drilling operations, and strikes a balance between data accuracy and practicality of the application

Assessment of spatial heterogeneity of ventricular repolarization after multi-channel blocker drugs in healthy subjects

Background and objectives: In contrast to potassium channel blockers, drugs affecting multiple channels seem to reduce torsadogenic risks. However, their effect on spatial heterogeneity of ventricular repolarization (SHVR) is still matter of investigation. Aim of this work is to assess the effect of four drugs blocking the human ether-\ue0-go-go-related gene (hERG) potassium channel, alone or in combination with other ionic channel blocks, on SHVR, as estimated by the V-index on short triplicate 10 s ECG. Methods: The V-index is an estimate of the standard deviation of the repolarization times of the myocytes across the entire myocardium, obtained from multi-lead surface electrocardiograms. Twenty-two healthy subjects received a pure hERG potassium channel blocker (dofetilide) and 3 other drugs with additional varying degrees of sodium and calcium (L-type) channel block (quinidine, ranolazine, and verapamil), as well as placebo. A one-way repeated-measures Friedman test was performed to compare the V-index over time. Results: Computer simulations and Bland-Altman analysis supported the reliability of the estimates of V-index on triplicate 10 s ECG. Ranolazine, verapamil and placebo did not affect the V-index. On the contrary, after quinidine and dofetilide administration, an increase of V-index from predose to its peak value was observed (\u394\u394V-index values were 19 ms and 27 ms, respectively, p < 0.05). Conclusions: High torsadogenic drugs (dofetilide and quinidine) affected significantly the SHVR, as quantified by the V-index. The metric has therefore a potential in assessing drug arrhythmogenicity

Cancellation of ventricular activity in endocavitary recordings during atrial fibrillation by Particle Swarm Optimization

The cancellation of ventricular activity (VA) from atrial electrogram (AEG) is commonly performed by template matching and subtraction (TMS): a running template, built by adaptive averaging of AEG segments in correspondence of QRS, is subtracted from AEG to uncover atrial activity (AA). In our approach, before subtraction, templates are modulated by a set of coefficients which are estimated by maximizing, via Multiple Particle Swarm Optimization (MPSO), a fitness function based on: 1) the energy of the estimated and measured AA; 2) the first derivative of the estimated and measured AA; 3) the similarity between the template and its modulated version. To validate the method, three datasets of 500 synthetic AEG were built. Each signal included background AA, localized AA and VA. We observed that TMS+MPSO provided better performances then TMS alone when the ratio of VA/AA amplitude is large (VA/AA 65 3), while the performances get closer when the ratio decreases

Anodal tDCS and High-Frequency tRNS Targeting the Occipitotemporal Cortex Do Not Always Enhance Face Perception

There has been increasing interest in the utility of transcranial electrical stimulation as a tool to enhance cognitive abilities. In the domain of face perception, enhancements have been reported for both transcranial direct current stimulation (tDCS) and high-frequency transcranial random noise stimulation (tRNS) targeting the occipitotemporal cortex. In a series of two experiments, we attempted to replicate these findings for face identity perception, and extend on previous studies, to determine if similar enhancements are also observed for object and facial expression perception. In Experiment 1, using a single blind, between-subjects design in healthy volunteers (N = 53), we examined whether anodal tDCS over the occipitotemporal cortex enhanced performance on tasks involving perception of face identity, facial expression, and object stimuli, when compared to sham stimulation. We failed to replicate previous findings of enhanced performance on face and object perception, nor extend findings to facial expression perception. In Experiment 2, using a single blind, between-subjects design (N = 39), we examined the effect of high-frequency tRNS over the occipitotemporal cortex using the same three tasks employed in Experiment 1. We failed to replicate previous findings of enhanced face perception following high-frequency tRNS over the occipitotemporal cortex, relative to sham stimulation (although we used different stimulation parameters to that employed in a previous study). We also found no evidence of enhanced facial expression and object perception following high-frequency tRNS. The findings align with a growing body of studies that have failed to replicate previously reported enhancements following administration of tDCS and hint for different efficacy of, on first sight, related stimulation protocols. Future studies should explore the foundation of these differential effects in greater detail

Fatigue behavior of foreign object damaged 7075 heat treated aluminum alloy coated with PVD WC/C

AbstractThe effect of a physically vapor deposited (PVD) WC/C coating on the fatigue behavior of as produced and foreign object damaged (FOD) solution heat treated and aged 7075 aluminum alloy was studied. Coated and uncoated samples were tested under rotating bending to determine the fatigue strengths between 104 and 106 cycles in both damaged and smooth condition. FOD was produced with single shots of small hard steel spheres impacting at 100 m/s in the minimum cross section. SEM was used to characterize the features of the fracture surfaces

Evaluation of the residual stresses induced by shot peening on some sintered steels

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Generation of otic lineages from integration-free human-induced pluripotent stem cells reprogrammed by mRNAs

Damage to the sensory hair cells and the spiral ganglion neurons of the cochlea leads to deafness. Induced pluripotent stem cells (iPSCs) are a promising tool to regenerate the cells in the inner ear that have been affected by pathology or have been lost. To facilitate the clinical application of iPSCs, the reprogramming process should minimize the risk of introducing undesired genetic alterations while conferring the cells the capacity to differentiate into the desired cell type. Currently, reprogramming induced by synthetic mRNAs is considered to be one of the safest ways of inducing pluripotency, as the transgenes are transiently delivered into the cells without integrating into the genome. In this study, we explore the ability of integration-free human-induced pluripotent cell lines that were reprogrammed by mRNAs, to differentiate into otic progenitors and, subsequently, into hair cell and neuronal lineages. hiPSC lines were induced to differentiate by culturing them in the presence of fibroblast growth factors 3 and 10 (FGF3 and FGF10). Progenitors were identified by quantitative microscopy, based on the coexpression of otic markers PAX8, PAX2, FOXG1, and SOX2. Otic epithelial progenitors (OEPs) and otic neuroprogenitors (ONPs) were purified and allowed to differentiate further into hair cell-like cells and neurons. Lineages were characterised by immunocytochemistry and electrophysiology. Neuronal cells showed inward Na+ () currents and outward () and inward K+ () currents while hair cell-like cells had inward and outward delayed rectifier K+ currents, characteristic of developing hair cells. We conclude that human-induced pluripotent cell lines that have been reprogrammed using nonintegrating mRNAs are capable to differentiate into otic cell types

The Digital Image Correlation technique applied to the deformation behavior of welded sheet joints

The existence of a welded zone generally influences the local strain and stress distribution especially in case of welding defects. A method able to measure the local deformability can hence give many important information about the real stress and strain fields useful to improve the welded structure design. In this experimental work, some new generation automotive steels have been considered, because of the well known welding problems due to their unstable microstructural condition. Such materials, known as Q&P steels and available only as thin sheets, require a suitable quenching process able to give high mechanical resistance and satisfying deformability. Some sheet samples were welded by electron beam technique, because it is able to reduce the width of the heat affected zone where the main microstructural changes are concentrated. From such samples, tensile specimens were machined. During the tensile tests, the deformations were measured both by a traditional extensometer and by a 3D Digital Image Correlation (3D DIC) technique. A preliminary investigation of the melted and the heat affected zones resulted in small dimensions (about 10 mm) and hence the measuring setup has been optimized in order maximize the achievable measuring resolution minimizing the resulting uncertainty. This result can be achieved by a pattern generated by a suitable software and by an accurate preparation of the surface where the pattern will be deposited on

The Modified Five-Point Test (MFPT): normative data for a sample of Italian elderly

INTRODUCTION: Non-verbal figural fluency is related to executive functions and specifically to the ability to create as many unique designs as possible, while minimizing their repetitions. An Italian version of figural fluency is the Modified Five-Point Test (MFPT), which is highly employed in the clinical practice of neuropsychologists. To date, reference data of Italian population are limited to a sample aged between 16 and 60 years old. Thus, the current study aims to provide normative data of the MFPT in the context of a population-based setting, conducted in Southern Italy. MATERIAL AND METHODS: We collected N = 340 Italian healthy subjects, aged over 65 years old (range: 65-91), pooled across subgroups for age, sex, and education. Multiple regression analyses were performed to estimate the effect of age, education, and sex on the participant's performance. Equivalent scores and cut-off scores were also defined for the number of unique designs (UDs) and the number of strategies (CSs). RESULTS: Multiple regression analyses revealed that UDs increase with decreasing age and increasing educational level. CSs are influenced by higher educational levels but neither by age nor sex. A significant inverse correlation between the UDs and percentage of errors occurred, suggesting that a higher number of UDs are associated with a fewer number of errors and higher CSs employed. CONCLUSION: The MFPT provides a measure of cognitive functioning in terms of the ability to initiate and realize designs, affording useful hints for clinical settings. The MFPT may represent a handy and useful tool with a specific focus in the differentiation of healthy versus pathological aging