Fragmentation and densities of meteoroids

Photographic observations of meteors carried out in Dushanbe by the method of instantaneous exposure have shown clearly that meteoroids entering the Earth's atmosphere are subjected to different types of fragmentation. The quasi-continuous fragmentation of meteoroids is mostly widespread. Using the physical theory of meteors which takes into account the quasi-continuous fragmentation of meteoroids and on the basis of light curves of meteors the densities of meteoroids of different streams have been determined. The results enable us to conclude that the densities of meteoroids are over an order of magnitude higher than they have been assumed before. Moreover they are close to the densities of carbonaceous and ordinary chondrites

P/Machholz 1986 8 and quadrantid meteoroid stream. Orbital evolution and relationship

The evolution of the P/Machholz's meteoroid stream was simulated. It shows that this stream may produce eight meteor showers. There are the known observed meteor showers such as the Quadrantids, Ursids, Northern and Southern delta-Aquarids, Daytime Arietids, and alpha-Cetids. A satisfactory agreement of the theoretical and observed geocentric radiants and orbits allows one to conclude that the above showers could have been resulted from the decay of the P/Machholz nucleus. The age of the stream is estimated to be 7.5 millennia

The Impact Of Circular Economy On Logistics Outsourcing Decisions: A Transaction Cost Perspective

Logistics outsourcing is a common practice in supply chain management, where firms delegate some or all of their logistics activities to external service providers. The main motivations for logistics outsourcing are to focus on core-competencies, achieve cost reductions, and access specialist know-how. However, the emergence of the circular economy (CE) paradigm, which aims to minimize waste and resource consumption by closing material loops, poses new challenges and opportunities for logistics outsourcing. The CE requires changes in product design, supply chain configuration, and manufacturing processes, which affect the nature and relevance of logistics activities along the value chain. Therefore, a reassessment of the make-or-buy decision factors in a CE is required. This paper investigates the effects of CE on the decision-making criteria for logistics outsourcing along the supply chain based on a literature review. The transaction cost theory is being adopted as a theoretical basis to evaluate the use of logistics outsourcing in the CE context. The paper contributes to the literature by offering an overview of the current state of knowledge and by suggesting directions for future research. Practical implications and recommendations for manufacturing firms and logistics service providers are derived from the findings

Break up of a round liquid jet in a low Weber number cross flow.

The break up of a liquid jet in cross flow has applications in fuel atomization processes. The break up of a water jet in a high speed cross flow was studied with momentum ratios ranging between 10 and 172. High-speed camera images showed break up characteristics ranging from bag break up (break up due to large ligaments or "bags" of fluid sheared off the liquid jet) to multimode break up (break up in which large ligaments and small drops are present), with large disturbances developing on the jet boundary. The disturbance wavelengths and break up locations were measured and compared, and the agreement was very good. It was also observed that as the cross flow velocity increased, the jet boundary spread linearly outward in the spanwise direction. Particle Image Velocimetry (PIV) results showed that the cross flow did not follow the jet boundary, but passed around the jet, similar to the flow around a bluff body. This implies that the Rayleigh-Taylor instability cannot be a dominant mechanism for the jet break-up. Spanwise PIV results indicate the presence of a high shear region along the sides of the jet, which might serve as the primary cause of jet break-up

The Importance of Social Competence in Teaching Foreign Languages

The article is devoted to the theoretical aspect of formation of social- cultural competence, which is necessary in teaching foreign languages. Socio-cultural competence is the ability of a communicative communicating in a foreign language to communicate effectively with other cultures, to find the right way to communicate and to choose a sophisticated speech and behavioral strategy, to acquire social sciences and skills. The foreign language learning process is a two-way activity, as well as learning a foreign language as well as mastering the capabilities of the mother tongue and its characteristics. Therefore, every course on foreign language is an intercultural cross-cultural communication point. Formation of socio-cultural competence of future professionals involves the preparation of a multinational person. A cultural-linguistic person is a person who has a culture and linguistic potential. Such a person will also be able to acquire linguistic means not only for his own culture, but also for the realization of his communicative intentions, regardless of social context.The content of teaching, of course, contains teaching culture and spiritual heritage. Next comes formation of the social-cultural competence in the process of teaching foreign languages. Implementation of socio-cultural approach to teaching foreign languages leads to the activation of students in mastering the foreign language, ie the student acquires the national culture and values of other people. In this process, the knowledge about the country where the language is studied is strengthened.  Keywords: teaching, linguistics, culture, values, a foreign language, intercultural relations, communicative competence, social-cultural competence

An experimental and analytical study of various soil slopes in laboratory conditions

Thesis (Master)--Izmir Institute of Technology, Civil Engineering, Izmir, 2009Includes bibliographical references (leaves: 134-147)Text in English; Abstract: Turkish and Englishxviii, 147 leavesSlope stability is a significant subject of geotechnical engineering. Slope failures triggered by rainfall are causing considerable damage and loss of life every year throughout the world. Especially at dry seasons when the rainfall is scarce, the ground can develop considerable amount of suction and this improves the shear strength of the soil. In rainy season, when rainfall infiltrates into ground, suction decreases, while the shear strength also reduces, which may lead to slope instability. One of the principle objectives of this study is to represent the development of soil-water interaction modeling system (SWIMS) at IYTE. Using this system; effects of 3 different parameters, such as: initial water content, soil density, slope angle on modelling unsaturated slope stability were studied. Moreover, effects of infiltration on slope stability in shallow landslides, where it is assumed that the ground water tables are located at significant depths, were examined.In this thesis study, 12 main slope model experiments were completed in laboratory conditions, using Soil-Water Interaction Modelling System (SWIMS) by varying 3 different parameters. Result of studies shows that slope angle is the most important parameter affecting slope stability. Furthermore, parameters such as; soil density, degree of relative compaction of soil and initial water content affects slope stability, while these parameters also affect slope surface erosion and infiltration depths. In addition to experimental studies conducted in laboratory conditions with the 12 main slope model experiments, slope stability analyses to find FOS were performed by using Plaxis V9 (2D) finite element program (FEM), which uses shear strength reduction (SSR) technique and infiltration analyses using the Plaxflow module to model the rainwater infiltration into slope soil were performed. The FEM analyses show conforming results with the actual observations made using the tested soil model in laboratory conditions

Amudaryo hududning yer suv resurslaridan oqilona foydalanishda tabiiy-meliorativ rayonlarning ro’li

Ushbu maqolada Amudaryo hududning yer suv resurslaridan oqilona foydalanishda tabiiy-meliorativ rayonlarning ro’li borish haqida ma'lumotlar keltirilgan

Do primary schools exist only for academic achievement? The school characteristics that affect parents’ private primary school preferences for their children

* This research is based on the secondt author’s master’s thesis. 1 Correspondance to: Kamil Arif Kırkıç (PhD), Faculty of Education, İstanbul Sabahattin Zaim University, İstanbul, Turkey. E-mail: [email protected] ORCID: 0000-0002- 8902-437X 2 .Teacher, Private Bilgiçağı Schools, İstanbul, Turkey. E-mail: [email protected] ORCID: 0000- 0001-5986-4573In the research process, it was aimed to determine the factors affecting the private school preferences of primary school parents. The population of the study is the parents of students studying in private schools in the Anatolian side of Istanbul in the 2017-2018 academic year. The research group consisted of 205 volunteer parents whose children were students in different private schools in Üsküdar, Ümraniye and Kadıköy districts of the Asian side of Istanbul. A personal information form and a 41-item questionnaire were applied to the participants. As a data collection tool, “Private School Preference Criteria” questionnaire was formed by taking expert opinion. According to the findings obtained from the analysis of the data collected in the research, the factors affecting the reasons for parents to prefer private schools are listed in order of priority: the characteristics of management and academic staff, physical conditions of the school, economic resources, communication processes, artistic, sportive, social and cultural activities and the last one educational activities. According to the preference of the parents varies according to being a mother or father, three items of the physical conditions; two items in teaching activities and one item in artistic, cultural, sportive, social and cultural activities dimensions were determined. No item differentiated in the other two dimensions