45 research outputs found
Dynamic effects and large – amplitude motion in Jacobi and Poincaré shape transitions in atomic nuclei
The Jacobi and Poincaré shape transitions are very promising way to investigate the shape of the nucleus. The presented here quasi-phenomenological approach allows to estimate the experimental conditions which are necessary to observe these phenomena. The static energy minimum gives the spin ranges and the fissility of atomic nuclei soft for the shape transitions and available experimentally. Dynamical effects taken into account through the solving collective Hamiltonian for zero-point vibration estimation, changes the spin rages for the shape transitions. The static deformation of the nucleus constrained by the minimum of energy for given spin has been enhanced to dynamical nuclear shapes permitted by the zero point energy. The large amplitude vibrations around the static deformation gives the ensemble of nuclear shapes possible to be observed
The use of transfer learning with very deep convolutional neural network in quality management
PURPOSE: The aim of the article is to develop an algorithm for classifying cracks in the analyzed
images using modern methods of deep machine learning and transfer learning based on
pretrained convolutional neural network - Inception-ResNet-v2.DESIGN/METHODOLOGY/APPROACH: Transfer learning based on the pretrained convolutional
neural network was used to categorize the images. The fully conected layer of the InceptionResNet-v2 network has been modified. The last layer was trained using a two-class (binary)
linear SVM (Support Vector Machine). In total, 20,000 training cases (images) were used to
train the fully connected layer within transfer learning process. The research analyzed the
possibility of using the deep neural networks for quick and fully automatic identification of
cracks / defects on the surface of analyzed parts.FINDINGS: The results indicate that pretrained convolutional neural network using SVM to
train a fully connected layer is a very effective solution for visual crack / fault detection. In the
analyzed model, a positive classification was obtained at the level of 99.89%.PRACTICAL IMPLICATIONS: The model presented in the article can be used in quality control
carried out by process monitoring. An effective model for identifying defective parts can be
used in both logistics and production processes.ORIGINALITY/VALUE: A novelty is the use of a freely available, deep neural network trained to
classify 1000 categories of various images for binary categorization of faults (cracks). The
algorithm was adjusted by replacing the primary, 1000-output fully connected layer in the
Inception-ResNet-v2 network with a binary layer (2 categories). The fully connected layer has
been trained using the classification version of the popular SVM learner, but thanks to the
combination of this layer with the sophisticated fearure extraction ability of the pre-trained
Inception-ResNet-v2 deep network, the resulting predictive model enables the classification of
defects with a very high level of accuracy.peer-reviewe
Neonicotinoids and their substitutes in sustainable pest control
ISBN 978-3-8047-4144-7, EASAC / FEAM REPORT (European Academies Science Advisory Council / Federation of Auropean Academies of Medicine
High efficiency protocol of DNA extraction from Micromys minutus mandibles from owl pellets: a tool for molecular research of cryptic mammal species
Modele sieci bibliotek publicznych na wsi na tle struktury osadniczej
W pracy podjęto próbę określenia wzorcowych modeli sieci bibliotek publicznych na wsi. Jako dane wyjściowe przyjęto m.in. Klasyfikację Instytutu Urbanistyki i Architektury w zakresie form osadnictwa wiejskiego; stan i wyniki badań nad organizacją sieci bibliotek publicznych na wsi od 1957 r.; ogólne założenia polityki bibliotecznej w kraju, wynikające z Ustawy o bibliotekach i szczegółowych aktów prawnych; aktualny stan prawno-organizacyjny bibliotek wiejskich
(Ti,Al)O2 Whiskers Grown during Glow Discharge Nitriding of Ti-6Al-7Nb Alloy
Plasma nitriding of titanium alloys is capable of effective surface hardening at temperatures significantly lower than gas nitriding, but at a cost of much stronger surface roughening. Especially interesting are treatments performed at the lower end of the temperature window used in such cases, as they are least damaging to highly polished parts. Therefore identifying the most characteristic defects is of high importance. The present work was aimed at identifying the nature of pin-point bumps formed at the glow discharged plasma nitrided Ti-6Al-7Nb alloy using plan-view scanning and cross-section transmission electron microscopy methods. It helped to establish that these main surface defects developed at the treated surface are (Ti,Al)O2 nano-whiskers of diameter from 20 nm to 40 nm, and length up to several hundreds of nanometers. The performed investigation confirmed that the surface imperfection introduced by plasma nitriding at the specified range should be of minor consequences to the mechanical properties of the treated material
Microstructure of Coatings on Nickel and Steel Platelets Obtained by Co-Milling with NiAl and CrB2 Powders
Metal matrix composite coatings are developed to protect parts made from materials susceptible to wear, like nickel alloys or stainless steel. The industry-established deposition method is presently an atmospheric plasma spraying method since it allows the production of both well-adhering and thick coatings. Alternatively, similar coatings could be produced by co-milling of ceramic and alloyed powders together with metallic plates serving as substrates. It results in mechanical embedding of the powder particles into exposed metallic surfaces required coatings. The present experiment was aimed at the analysis of microstructure of such coatings obtained using NiAl and CrB2 powders. They were loaded together with nickel and stainless steel platelets into ball mill vials and rotated at 350 rpm for up to 32 h. This helped to produce coatings of a thickness up to ~40 µm. The optical, scanning, and transmission electron microscopy observations of the coatings led to conclusion that the higher the rotation speed of vials, the wider the intermixing zone between the coating and the substrate. Simultaneously, it was established that the total thickness of the coating deposited at specified conditions is limited by the brittleness of its nanocrystalline matrix. An increase in the hardness of the substrate results in a decrease of the intermixing zone. The above results indicate that even as the method based on mechanical embedding could so far produce thinner coatings than the plasma spraying, in the former case they are characterized by a more uniform nanocrystalline matrix with homogenously distributed fine ceramic particles
Coating of Tungsten Wire with Ni/Al Multilayers for Self-Healing Applications
Self-healing materials are able to partially or completely reverse the damage inflicted on them. The possibility of self-healing mechanical and chemical failures that occur during service will improve the lifetime and reliability of structural materials. For this purpose, two main steps must be considered: (i) detection, and (ii) repairing (healing) of cracks. The exothermic character of reactive multilayers has potential for self-healing applications, namely in the healing step. In this context, Ni(V)/Al multilayer thin films were deposited onto tungsten wires by magnetron sputtering from two targets. A detailed microstructural characterization was carried out by scanning and transmission electron microscopy after deposition, as well as after ignition by applying an electrical discharge. The as-deposited films presented an irregular layered structure with local defects not observed for flat substrates, although Ni- and Al-rich nanolayers could be distinguished. The as-reacted films were constituted by Al3Ni2 grains with Al3V phase at the grain boundaries. In order to use reactive multilayers for self-healing purposes, the heat released must be maximised by improving the microstructure of the nanolayered films. Nevertheless, after ignition, the Ni(V)/Al multilayer films deposited onto W wire underwent a self-sustained reaction, releasing heat