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This paper focusses on obtaining a better understanding of the subsurface geology of the Chibougamau area, in the northeast of the Abitibi greenstone belt (Superior craton), using geophysical data collected along a 128 km long traverse with a rough southwest--northeast orientation. We have constructed two-dimensional (2D) models of the study area that are consistent with newly collected gravity data and high-resolution magnetic data sets. The initial models were constrained at depth by an interpretation of a new seismic section and at surface by the bedrock geology and known geometry of lithological units. The attributes of the model were constrained using petrophysical measurements so that the final model is compatible with all available geological and geophysical data. The potential-field data modelling resolved the geometry of plutons and magnetic bodies that are transparent on seismic sections. The new model is consistent with the known structural geology, such as open folding, and provides an improvement in estimating the size, shape, and depth of the Barlow and Chibougamau plutons. The Chibougamau pluton is known to be associated with Cu--Au magmatic-hydrothermal mineralisation and, as the volume and geometry of intrusive bodies is paramount to the exploration of such mineralisation, the modelling presented here provides a scientific foundation to exploration models focused on such mineralisation. Key words: geophysics, potential-field modelling, 2.5D modelling, geological modelling, geological, seismic and petrophysical constraints, gravity and magnetic. L'article est axe sur l'etablissement d'une meilleure comprehension de la geologie du sous-sol de la region de Chibougamau, dans le nord-est de la ceinture de roches vertes de l'Abitibi (craton du Superieur), a la lumiere de donnees geophysiques recueillies le long d'une traverse de 128 km d'orientation approximativement sud-ouest--nord-est. Nous avons construit des modeles bidimensionnels (2D) de la region a l'etude qui concordent avec des donnees gravimetriques et des ensembles de donnees magnetiques de haute resolution nouvellement acquis. Les modeles initiaux ont ete delimites en profondeur par l'interpretation d'une nouvelle coupe sismique et en surface par la geologie du substrat rocheux et la geometrie connue des unites lithologiques. Les attributs du modele ont ete etablis en utilisant des mesures petrophysiques, le modele final etant ainsi compatible avec toutes les donnees geologiques et geophysiques disponibles. La modelisation des donnees de champ de potentiel a permis de cerner la geometrie de plutons et de corps magnetiques qui sont transparents sur les coupes sismiques. Le nouveau modele s'accorde avec les elements connus de la geologie structurale, comme un plissement ouvert, et ameliore l'estimation de la taille, de la forme et de la profondeur des plutons de Barlow et de Chibougamau. Il est etabli que ce dernier est associe a une mineralisation magmatique-hydrothermale a Cu--Au et, comme le volume et la geometrie des corps intrusifs revetent une importance capitale dans l'exploration pour ce type de mineralisation, la modelisation presentee constitue un fondement scientifique pour les modeles d'exploration axes sur ce type de mineralisation. [Traduit par la Redaction] Mots-cles : geophysique, modelisation du champ de potentiel, modelisation en 2,5D, modelisation geologique, contraintes geologiques, sismiques et petrophysiques, gravite et magnetisme., Introduction The Metal Earth project aims to better understand the differences between greenstone belts in the Abitibi and Wabigoon belts of the Superior craton of Canada that are well endowed [...]

Conductive polymer composites (CPCs) are manufactured by compounding conductive particles with a polymer matrix. There are many applications where they are used, including light-weight applications requiring both electrical and heat conductivity. Carbon nanotubes (CNTs) have been accepted as common materials to accomplish this goal. As part of this research, a material extrusion additive manufacturing (AM) process was utilized to create nanocomposites by a 3D-printing technique. Multi-wall carbon nanotubes (MWCNTs) were mixed in 1, 3 and 6 wt fractions with acrylonitrile butadiene styrene (ABS) and extruded in filament form. Three-dimensionally printed specimens were used to evaluate electrical, electromagnetic interference shielding effectiveness (EMI SE) and tensile properties. The electrical conductivity of the material was 26 times greater than that of ABS. In the X-band of electromagnetic waves, EMI SE's reflected and absorbed portions increased respectively 4 and 16 times. The tensile strength and modulus were enhanced by 15% and 9%, respectively. On composite specimens, microwave heat treatment was applied. There is less void space between the rasters and layers, which helps improve tensile properties. Additionally, 3D-printed specimens were tested for melt flow rate (MFR) and dynamic mechanical behaviour. The nozzle has experienced some wear due to the intrinsic abrasive nature of CNTs. [ABSTRACT FROM AUTHOR]

Deep learning methods can be used to produce control policies, but certifying their safety is challenging. The resulting networks are nonlinear and often very large. In response to this challenge, we present OVERT: a sound algorithm for safety verification of nonlinear discrete-time closed loop dynamical systems with neural network control policies. The novelty of OVERT lies in combining ideas from the classical formal methods literature with ideas from the newer neural network verification literature. The central concept of OVERT is to abstract nonlinear functions with a set of optimally tight piecewise linear bounds. Such piecewise linear bounds are designed for seamless integration into ReLU neural network verification tools. OVERT can be used to prove bounded-time safety properties by either computing reachable sets or solving feasibility queries directly. We demonstrate various examples of safety verification for several classical benchmark examples. OVERT compares favorably to existing methods both in computation time and in tightness of the reachable set. [ABSTRACT FROM AUTHOR]

One of the main challenges for the conventional protection system of a photovoltaic (PV) array is the occurrence of light fault conditions including a low location mismatch fault, a fault with a high fault path resistance, and a fault under low solar irradiance because the fault current increment is not enough for triggering current-based protective devices. The operation of the maximum power point tracking system and utilizing blocking diodes may also result in a light fault condition. An undetected fault condition causes a potential fire hazard and energy loss. This paper proposes a waveshape based statistical fault detection algorithm for light fault detection. The proposed algorithm quantifies the waveshape tailedness of superimposed PV array power by the kurtosis function. The proposed algorithm is able to discriminate the light fault condition from severe partial shading and is also effective for open-circuit faults. In addition to no need for additional sensors, it does not require a training dataset and prior information about the PV array. The merits of the proposed algorithm are corroborated through several case studies on a simulation model of a test PV array considering the parameter uncertainty and the presence of noise in the signals. [ABSTRACT FROM AUTHOR]

There is a widely popular perception in the cementing community that the turbulent regime should be used where possible in primary cementing of oil and gas wells. We conduct a detailed numerical study and analyze turbulent annular displacement flows. In particular, we show what roles viscous and buoyancy stresses play in the displacement efficiency. More importantly, we argue that the long-standing industry practice of preferring a turbulent displacement flow over laminar is over-simplistic and questionable. Indeed, we demonstrate that if the flow rate is increased very much when turbulent, steady displacements will be lost. [ABSTRACT FROM AUTHOR]

We present a new method to track the interface between two fluids in an annular displacement flow typical of setting surface casing in the primary cementing of oil and gas wells. The main idea is to exploit the density difference between successive fluids pumped in order to design a tracer particle to sit at the interface. Although apparently trivial, such particles must overcome viscous drag and strong secondary flows in order to reach and remain at the interface. We explore the underlying physics through both a simple toy model and using a full annular displacement simulation. The study provides a proof of concept that the method can work, but also exposes some limitations in terms of cementing parameters and particle properties. As well as demonstrating feasibility, we explore how some of these limitations might be overcome. [ABSTRACT FROM AUTHOR]

This study investigates political culture in the city of Tehran, focusing on three of its domains including typology of political culture, classification and typology of political citizens, as well as examination of some variables affecting political culture in Iran. The applied research method is in the form of a survey and questionnaire-based data. The study sample size includes 612 citizens residing in Tehran in 2018. Findings show that most citizens are tended to a subjectparochial political culture. It is indicated that political variables i.e. the cost of political activity, government officials' responsiveness, and institutional political trust are effective on political culture. Using cluster method, the citizens were divided into four categories: critical, obedient, unmotivated, and disappointed. Political culture factors are categorized in three groups by analyzing exploratory factors. These are: pluralistic, value, and involvement -behavioral. Findings show that, citizens have been grown higher in pluralistic, and with value aspects, but are in a low level with behavioral aspect, and this factor could be effective on political culture's type. [ABSTRACT FROM AUTHOR]

Background Our aim in this study was to identify prognostic factors and the optimal therapeutic management in patients with minor salivary gland carcinomas. Methods Overall and disease-free survival and overall survival after recurrence in patients with adenoidcystic carcinoma (n = 25), mucoepidermoid carcinoma (n = 8), adenocarcinoma (n = 5), carcinoma ex pleomorphic adenoma (n = 4), and others (n = 5) were correlated to clinical data. Results Overall survival correlated to treatment modality (p = .039) and T classification (p = .003), whereas prolonged disease-free interval correlated to treatment (p < .001) and T classification (p = .009). Overall survival after recurrence correlated to treatment of recurrence (p = .006) and initial T classification (p = .02). Multivariate analysis showed that overall survival after recurrence correlated to treatment of recurrence (p = .019) and initial T classification (p = 0.019). T classification was a prognostic factor for overall survival (p = .002) and disease-free interval (p = .002). Conclusions The initial tumor classification is a clinical predictor for patients' overall and disease-free survival and overall survival after recurrence. Multimodal treatment significantly improves patients' overall survival. © 2010 Wiley Periodicals, Inc. Head Neck, 2010 [ABSTRACT FROM AUTHOR]