Analysis of radiation patterns of interaction tones generated by inlet rods in the JT15D engine

Interaction tones were intentionally generated by circumferential arrays of equally spaced rods that protrude radially from the inlet wall near the face of the 28-blade fan. Arrays of 28 and 41 rods, selected to give specific far field radiation properties, were tested. The expected properties were readily apparent in the measured radiation patterns. A more detailed analysis of the test data showed both the precision and limitations of the applied acoustic theory. Rods protruding 23 percent of the radius predominantly generated only lowest radial order modes, as expected. Measured and predicted radiation patterns were generally in good agreement. The agreement, however, depended on a significant degree of implied refraction due to inlet velocity gradients. Refraction, if present, would impact static-flight noise comparisons

Efficacy of the SU(3) scheme for ab initio large-scale calculations beyond the lightest nuclei

We report on the computational characteristics of ab initio nuclear structure calculations in a symmetry-adapted no-core shell model (SA-NCSM) framework. We examine the computational complexity of the current implementation of the SA-NCSM approach, dubbed LSU3shell, by analyzing ab initio results for 6Li and 12C in large harmonic oscillator model spaces and SU(3)-selected subspaces. We demonstrate LSU3shell's strong-scaling properties achieved with highly-parallel methods for computing the many-body matrix elements. Results compare favorably with complete model space calculations and significant memory savings are achieved in physically important applications. In particular, a well-chosen symmetry-adapted basis affords memory savings in calculations of states with a fixed total angular momentum in large model spaces while exactly preserving translational invariance.Comment: 11 pages, 8 figure

Collective Modes in Light Nuclei from First Principles

Results for ab initio no-core shell model calculations in a symmetry-adapted SU(3)-based coupling scheme demonstrate that collective modes in light nuclei emerge from first principles. The low-lying states of 6Li, 8Be, and 6He are shown to exhibit orderly patterns that favor spatial configurations with strong quadrupole deformation and complementary low intrinsic spin values, a picture that is consistent with the nuclear symplectic model. The results also suggest a pragmatic path forward to accommodate deformation-driven collective features in ab initio analyses when they dominate the nuclear landscape.Comment: 5 pages 3 figures, accepted to Physical Review Letter

Experimental investigation of tsunami waves generated by granular collapse into water

The generation of a tsunami wave by an aerial landslide is investigated through model laboratory experiments. We examine the collapse of an initially dry column of grains into a shallow water layer and the subsequent generation of waves. The experiments show that the collective entry of the granular material into water governs the wave generation process. We observe that the amplitude of the wave relative to the water height scales linearly with the Froude number based on the horizontal velocity of the moving granular front relative to the wave velocity. For all the different parameters considered here, the aspect ratio and the volume of the column, the diameter and density of the grains, and the height of the water, the granular collapse acts like a moving piston displacing the water. We also highlight that the density of the falling grains has a negligible influence on the wave amplitude, which suggests that the volume of grains entering the water is the relevant parameter in the wave generation.Comment: 23 pages, 16 figure

Ways to Enhance Students’ Learning Activities in the Context of Higher Education

The article aims to study scientific and methodological features of the ways to enhance students’ learning activities in the context of higher education. The study's theoretical significance is derived from the in-depth analysis of the development of students' learning activity. The study offers the framework of characteristics for the concept of “students' learning (cognitive) activity". The main used methods were: analysis, peer-assessment, self-assessment. The interview method was used to make a cognitive profile of the participants, taking into account their psychological characteristics. The authors developed and scientifically tested educational model based on module curricula and interactive teaching methods to enhance students' learning activity. The authors also reflected the dynamic of the learning activity of the students with disabilities participating in the experiment. The results proved the effectiveness of the developed model of enhancing students' learning activity by using interactive teaching methods. It was concluded that the module curricular and active teaching methods help enhance students with disabilities' learning activity and make them more responsible in respect to the results of their study

Rootstocks and Varieties of Fruits, Berry Crops, and Grapes, Used for Intensive Gardening in Kazakhstan

The results of the study of clonal rootstocks of apple trees of various ecological and geographical origins, varieties of fruit, berry crops, and grapes of local selection are presented. According to the efficiency of reproduction in the mother liquor and fields of nursery formation, as well as the short stature of trees of grafted varieties in the garden, precocity and productivity, clonal rootstocks of the apple tree B7-35, Arm18, 62-396, and B16-20 were distinguished. Their important role in unlocking the potential of ancient apple varieties in the south and southeast of Kazakhstan. These rootstocks and varieties are recommended for propagation and creation of highly productive orchards. The Ministry of Agriculture of the Republic of Kazakhstan provided funding within the framework of the budget program 267 “Improving the availability of knowledge and scientific research” under subprogram 101 “Program-targeted financing of scientific research and activities” – Creation of varieties and hybrids of fruit and berry, nut crops and grapes based on the achievements of bio and IT technologies, 2021–2023yy. No. BR10765032

SYMULACJA ZAGROŻEŃ BEZPIECZEŃSTWA INFORMACJI W ZAKRESIE DOSTĘPNOŚCI DOKUMENTÓW PROJEKTOWYCH W OPARCIU O LOGIKĘ ROZMYTĄ

The widespread use of computer technology, its rapid development and use in almost all areas of human activity requires constant updating of information security issues. The activities of many enterprises in the field of IT, construction, and other areas are of a project nature and therefore further research on information security management of projects is relevant. Appearance of changes and the current state of the project results at certain points of time describe the documents that accompany it. In this paper, the information structure of the project is considered as a set of specific documents. During the life cycle of each project document, which includes the creation, transfer, preservation and transformation, there are generally threats to its confidentiality, integrity, accessibility and authenticity. This paper develops a method for assessing the risks of violation of the availability of project documents in solving information security problems. A formal description of many project documents in the form of a generalized hierarchical structure is presented, the connection of documents with the operations performed on them and information systems used during these operations is formalized. Given the incompleteness and dimension of the data, the based on fuzzy logic model was developed to assess the risk of document accessibility. Approaches to the assessment of the damage from the violation of the availability of the project document and the method of calculating the overall assessment of the risk of violation of the documents availability are proposed. The results presented in this paper can be used in decision-making processes regarding information security of projects in organizations that have project activities. The approaches proposed in this paper can serve as a basis for the creation of specialized information technologies to automate the calculation of project risk assessments.Powszechne stosowanie techniki komputerowej, jej szybki rozwój i wykorzystanie niemal we wszystkich dziedzinach działalności człowieka wymaga ciągłej aktualizacji zagadnień związanych z bezpieczeństwem informacji. Działalność wielu przedsiębiorstw w zakresie informatyki, budownictwa i innych dziedzin ma charakter projektowy, dlatego istotne są dalsze badania nad zarządzaniem bezpieczeństwem informacji w projektach. Pojawienie się zmian i aktualny stan wyników projektu w określonych momentach czasu opisują towarzyszące mu dokumenty. W niniejszej pracy struktura informacyjna projektu jest rozpatrywana jako zbiór określonych dokumentów. W cyklu życia każdego dokumentu projektu, który obejmuje tworzenie, przekazywanie, przechowywanie i przekształcanie, występują na ogół zagrożenia dla jego poufności, integralności, dostępności i autentyczności. W pracy opracowano metodę oceny ryzyka naruszenia dostępności dokumentów projektowych w rozwiązywaniu problemów bezpieczeństwa informacji. Przedstawiono formalny opis wielu dokumentów projektowych w postaci uogólnionej struktury hierarchicznej, sformalizowano związek dokumentów z wykonywanymi na nich operacjami oraz systemami informatycznymi wykorzystywanymi podczas tych operacji. Biorąc pod uwagę niekompletność i wymiar danych, opracowano oparty na logice rozmytej model oceny ryzyka dostępności dokumentów. Zaproponowano podejście do oceny szkody z tytułu naruszenia dostępności dokumentu projektu oraz metodę obliczania ogólnej oceny ryzyka naruszenia dostępności dokumentów. Wyniki przedstawione w pracy mogą być wykorzystane w procesach decyzyjnych dotyczących bezpieczeństwa informacyjnego projektów w organizacjach prowadzących działalność projektową. Zaproponowane w pracy podejścia mogą stanowić podstawę do tworzenia specjalistycznych technologii informatycznych automatyzujących obliczanie oceny ryzyka projektu

Tailoring the transverse mode of a high-finesse optical resonator with stepped mirrors

Enhancement cavities (ECs) seeded with femtosecond pulses have developed into the most powerful technique for high-order harmonic generation (HHG) at repetition rates in the tens of MHz. Here, we demonstrate the feasibility of controlling the phase front of the excited transverse eigenmode of a ring EC by using mirrors with stepped surface profiles, while maintaining the high finesse required to reach the peak intensities necessary for HHG. The two lobes of a TEM01 mode of a 3.93m long EC, seeded with a single-frequency laser, are delayed by 15.6 fs with respect to each other before a tight focus, and the delay is reversed after the focus. The tailored transverse mode exhibits an on-axis intensity maximum in the focus. Furthermore, the geometry is designed to generate a rotating wavefront in the focus when few-cycle pulses circulate in the EC. This paves the way to gating isolated attosecond pulses (IAPs) in a transverse manner (similarly to the attosecond lighthouse), heralding IAPs at repetition rates well into the multi-10MHz range. In addition, these results promise high-efficiency harmonic output coupling from ECs in general, with an unparalleled power scalability. These prospects are expected to tremendously benefit photoelectron spectroscopy and extreme-ultraviolet frequency comb spectroscopy