Production of Gas Bubbles in Reduced Gravity Environments

In a wide variety of applications such as waste water treatment, biological reactors, gas-liquid reactors, blood oxygenation, purification of liquids, etc., it is necessary to produce small bubbles in liquids. Since gravity plays an essential role in currently available techniques, the adaptation of these applications to space requires the development of new tools. Under normal gravity, bubbles are typically generated by forcing gas through an orifice in a liquid. When a growing bubble becomes large enough, the buoyancy dominates the surface tension force causing it to detach from the orifice. In space, the process is quite different and the bubble may remain attached to the orifice indefinitely. The most practical approach to simulating gravity seems to be imposing an ambient flow to force bubbles out of the orifice. In this paper, we are interested in the effect of an imposed flow in 0 and 1 g. Specifically, we investigate the process of bubble formation subject to a parallel and a cross flow. In the case of parallel flow, we have a hypodermic needle in a tube from which bubbles can be produced. On the other hand, the cross flow condition is established by forcing bubbles through an orifice on a wall in a shear flow. The first series of experiments have been performed under normal gravity conditions and the working fluid was water. A high quality microgravity facility has been used for the second type and silicone oil is used as the host liquid

What influences women’s contraceptive choice? A cross-sectional study from Turkey

Objectives: In our study, we tried to investigate the determinants of women’s choices about contraception with the aim of discovering whether or not there is a difference in their preferences before and after consultation with a gynaecologist. Material and methods: A total of 1058 women were enrolled. They were given detailed information regarding contraception and contraceptive methods. Subsequently, a survey which was made of 21 questions was administered. Results: Contraceptive counselling significantly changed the contraceptive choice of women. However, influences from social media and friends, their partners and religious belief affected their contraceptive choices. Significant differences in contraceptive choice were observed when women were categorized according to their marital status, education level, household income, age, and number of children. Conclusions: Although contraceptive counselling influenced Turkish women’s choices, there were still other determinants like social media and input from outside sources such as clerics and husbands, which should be overcome

O papel do conhecimento tácito na adesão às normas sociais

This paper aims to contribute to the ongoing discussion on adherence to social norms. It considers insights from multiple research traditions in an effort to explain how individual learning and action are connected to social norms. One strand of philosophical tradition holds that non-representational learning and skillful coping carried out unconsciously are underestimated by both scientific and philosophical traditions. The present research combines this tradition with the literature on the evolution of social norms and suggests that experienced individuals in a society adhere to social norms better than novice agents do. We explain this phenomenon by unconscious and non-representational cognitive processes. This framework is then used to investigate population-level outcomes of individual learning.Keywords: adherence to norms, expertise, skillful coping.Este artigo tem como objetivo contribuir para a discussão em curso sobre a adesão às normas sociais. Ele cosnidera insights de múltiplas tradições de pesquisa em um esforço para explicar como a aprendizagem e a ação individuais estão conectadas às normas sociais. Uma vertente da tradição filosófica sustenta que a aprendizagem não representacional e o enfrentamento hábil inconscientemente são subestimados pelas tradições científicas e filosóficas. A presente pesquisa combina esta tradição com a literatura sobre a evolução das normas sociais e sugere que os indivíduos experientes em uma sociedade adiram às normas sociais melhor do que os agentes novatos. Explicamos este fenômeno por processos cognitivos inconscientes e não representativos. Este quadro é então utilizado para investigar resultados de nível individual da aprendizagem individual.Palavras-chave: aderência às normas, perícia, habilidades de enfrentamento

Identification of the income level needed for agricultural enterprises to achieve economic sustainability

This study aims to identify the income level required for agricultural enterprises to achieve economic sustainability. The theory behind the equation used to calculate a sustainable income is explained. The ecological, technical, social and economic components of sustainability in agricultural enterprises have been identified and discussed and the importance of economic sustainability in terms of achieving total sustainability has been emphasised. Economic sustainability was divided into three components incorporating the income needed to meet the cost of living and to address depreciation and interest costs for the enterprise. Those enterprises that achieved this income level were determined to be economically sustainable. For this purpose, data was collected by using a face-to-face survey method with 181 agricultural enterprises operating in Konya and analysed in line with the purpose of the study. According to the results of our analysis, it was observed that more than 150 enterprises were not sustainable

Management Style at Turkish SMEs

Republic of Turkey is one of those countries where SMEs are flourishing and acting as a driving force of development. In this paper, we explore management style at Turkish SMEs. Being an intersection of eastern and western cultures and with the recent liberalization of domestic markets, we believe this exploration can lead to interesting results. In this paper authors take a glance at Turkish SMEs. We investigate the management style at Turkish SMEs. We have gathered data from 421 SMEs located in Republic of Turkey, using a previously developed questionnaire. This study is an exploratory one and no hypothesis is configured. There are significant results regarding management style of Turkish SMEs. Individuals are more likely to work within a group and formal organizational structures and management policies are implemented as SMEs grow larger. 

Enhanced self-collimation effect by low rotational symmetry in hexagonal lattice photonic crystals

In this study, we present the design of a photonic crystal (PC) structure with a hexagonal lattice, where adjustments to the PC unit cell symmetry reveal an all-angle self-collimation (SC) effect. By optimizing opto-geometric parameters, such as the rotational angle of auxiliary rods and adjacent distances, we analyze the SC property in detail, leveraging group velocity dispersion (GVD) and third-order dispersion (TOD) characteristics. We also investigate the relationship between symmetry properties and their influence on dispersion characteristics. Through symmetry manipulation, we gain a comprehensive understanding of the underlying mechanisms governing light collimation and confinement in the proposed configurations. The PC structure with a $C_1$ symmetry group exhibits all-angle SC effect within the range of $a/\lambda=0.652$ and $a/\lambda=0.668$ normalized frequencies, with a bandwidth of $\Delta \omega/\omega_c = 2.4\%$. Further breaking the symmetry, transforming from $C_1$ to $C_2$ group symmetry, enhances the SC bandwidth to $\Delta \omega/\omega_c =6.5\%$ and reveals the perfect linear equi-frequency contours (EFC) at two different frequency bands: all angle SC between $a/\lambda = 0.616$ and $a/\lambda = 0.656$ normalized frequencies in the 4th transverse magnetic (TM) band and between $a/\lambda=0.712$ and $a/\lambda=0.760$ in the 5th TM band. Additionally, we propose a composite/hybrid PC structure resembling $C_2$ group symmetry, where two auxiliary rods are replaced by rectangular photonic wires with the same refractive index and width equal to the diameter of auxiliary rods. This hybrid structure exhibits an all-angle SC effect with an operating bandwidth of $\Delta \omega/\omega_c =11.7\%$, displays near-zero GVD and TOD performance and offers enhanced robustness against potential fabrication precision issues