Search results for: foreign object damage
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4989

Search results for: foreign object damage

3519 The Negative Impact of Mindfulness on Creativity: An Experimental Test

Authors: Marine Agogue, Beatrice Parguel, Emilie Canet

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Defined as receptive attention to and awareness of present events and experience, mindfulness has grown in popularity over the past 30 years to become a trendy buzzword in business media, which regularly reports on its organizational benefits. Mindfulness would enhance or impede creative thinking depending on the type of meditation. Specifically, focused-attention meditation (focusing attention on one object instead of being open to perceive and observe any sensation or thought) would not be or negatively correlated to creativity. This research explores whether mood, in its two dimensions (i.e., hedonic tone, activation level), could mediate this potentially negative effect. The rationale is that focused-attention meditation is likely to improve hedonic tone but, in the meantime, damage activation level, resulting in opposite effects on creativity through the mediation effect of creative self-efficacy, i.e., the belief that one can perform successfully in an ideation setting. To test this conceptual model, a survey was administered to 97 subjects (53% women, mean age: 25 years), randomly assigned to three conditions (a 10-minute focused-attention meditation session vs. a 10-minute psychometric tests session vs. a control condition) and asked to participate in the egg creative task. Creativity was measured in terms of fluency, expansivity, and originality, the other variables using existing scales: hedonic tone (e.g., joyful, happy), activation level (e.g., passive, sluggish), creative self-efficacy (e.g., ‘I felt confident in my ability to do the task effectively’) and self-perceived creativity (e.g., ‘I have lots of original ideas’). The chains of mediation were tested using PROCESS macro (model 6) and controlled for subjects’ gender, age, and self-perceived creativity. Comparing the mindfulness and the control conditions, no difference appeared in terms of creativity, nor any mediation chain by hedonic tone. However, subjects who participated in the meditation session felt less active than those in the control condition, which decreased their creative self-efficacy, and creativity (whatever the indicator considered). Comparing the mindfulness and the psychometric tests conditions, analyses showed that creativity was higher in the psychometric tests condition. As previously, no mediation chain appeared by hedonic tone. However, subjects who participated in the meditation session felt less active than those in the psychometric tests condition, which decreased their creative self-efficacy, and creativity. These findings confirm that focused-attention meditation does not enhance creativity. They demonstrate an emotional underlying mechanism based on activation level and suggest that both positive and active mood states have the potential to enhance creativity through creative self-efficacy. In the end, they should discourage organizations from trying to nudge creativity using mindfulness ad hoc devices.

Keywords: creativity, mindfulness, creative self-efficacy, experiment

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3518 The Impact of Developing an Educational Unit in the Light of Twenty-First Century Skills in Developing Language Skills for Non-Arabic Speakers: A Proposed Program for Application to Students of Educational Series in Regular Schools

Authors: Erfan Abdeldaim Mohamed Ahmed Abdalla

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The era of the knowledge explosion in which we live requires us to develop educational curricula quantitatively and qualitatively to adapt to the twenty-first-century skills of critical thinking, problem-solving, communication, cooperation, creativity, and innovation. The process of developing the curriculum is as significant as building it; in fact, the development of curricula may be more difficult than building them. And curriculum development includes analyzing needs, setting goals, designing the content and educational materials, creating language programs, developing teachers, applying for programmes in schools, monitoring and feedback, and then evaluating the language programme resulting from these processes. When we look back at the history of language teaching during the twentieth century, we find that developing the delivery method is the most crucial aspect of change in language teaching doctrines. The concept of delivery method in teaching is a systematic set of teaching practices based on a specific theory of language acquisition. This is a key consideration, as the process of development must include all the curriculum elements in its comprehensive sense: linguistically and non-linguistically. The various Arabic curricula provide the student with a set of units, each unit consisting of a set of linguistic elements. These elements are often not logically arranged, and more importantly, they neglect essential points and highlight other less important ones. Moreover, the educational curricula entail a great deal of monotony in the presentation of content, which makes it hard for the teacher to select adequate content; so that the teacher often navigates among diverse references to prepare a lesson and hardly finds the suitable one. Similarly, the student often gets bored when learning the Arabic language and fails to fulfill considerable progress in it. Therefore, the problem is not related to the lack of curricula, but the problem is the development of the curriculum with all its linguistic and non-linguistic elements in accordance with contemporary challenges and standards for teaching foreign languages. The Arabic library suffers from a lack of references for curriculum development. In this paper, the researcher investigates the elements of development, such as the teacher, content, methods, objectives, evaluation, and activities. Hence, a set of general guidelines in the field of educational development were reached. The paper highlights the need to identify weaknesses in educational curricula, decide the twenty-first-century skills that must be employed in Arabic education curricula, and the employment of foreign language teaching standards in current Arabic Curricula. The researcher assumes that the series of teaching Arabic to speakers of other languages in regular schools do not address the skills of the twenty-first century, which is what the researcher tries to apply in the proposed unit. The experimental method is the method of this study. It is based on two groups: experimental and control. The development of an educational unit will help build suitable educational series for students of the Arabic language in regular schools, in which twenty-first-century skills and standards for teaching foreign languages will be addressed and be more useful and attractive to students.

Keywords: curriculum, development, Arabic language, non-native, skills

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3517 Service Life Study of Polymers Used in Renovation of Heritage Buildings and Other Structures

Authors: Parastou Kharazmi

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Degradation of building materials particularly pipelines causes environmental damage during renovation or replacement and is a time consuming and costly process. Rehabilitation by polymer composites is a solution for renovation of degraded pipeline in heritage buildings and other structures which are less costly, faster and causes less damage to the environment; however, it is still not clear for how long these materials can perform as expected in the field and working condition. To study their service life, two types of composites based on Epoxy and Polyester resins have been evaluated by accelerated exposure and field exposure. The primary degradation agent used in accelerated exposure has been cycling temperature with half of the tests performed in presence of water. Thin films of materials used in accelerated testing were prepared in laboratory by using the same amount of material as well as technique of multi-layers application used in majority of the field installations. Extreme intensity levels of degradation agents have been used only to evaluate materials properties and as also mentioned in ISO 15686, are not directly correlated with degradation mechanisms that would be experienced in service. In the field exposure study, the focus has been to identify possible failure modes, causes, and effects. In field exposure, it has been observed that there are other degradation agents present which can be investigated further such as presence of contaminants and rust before application which prevents formation of a uniform layer of polymer or incompatibility between dissimilar materials. This part of the study also highlighted the importance of application’s quality of the materials in the field for providing the expected performance and service life. Results from extended accelerated exposure and field exposure can help in choosing inspection techniques, establishing the primary degradation agents and can be used for ageing exposure programs with clarifying relationship between different exposure periods and sites.

Keywords: building, renovation, service life, pipelines

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3516 Aloe vera Prevents Injuries Induced by Whole Body X-ray Irradiation in Rodents

Authors: Shashi Bala, Neha A. Chugh, Subhash C. Bansal, Mohal L. Garg, Ashwani Koul

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Purpose: The present study was designed to evaluate the radioprotective efficacy of Aloe vera from whole body X-ray exposure in rodents. Materials and Methods: For this purpose, after on week’s acclimatization, male balb/c mice procured from Central Animal House, Panjab University, Chandigarh (India), were divided into four groups: Group I mice served as control. Group II mice were orally administrated Aloe vera pulp extract (50 mg/ kg body weight) on alternate days for 30 days. Group III mice were subjected to whole body X-ray irradiation to cumulative dose of 2Gy (0.258Gy twice a day for four days in the last week). Group IV animals were pretreated with Aloe vera pulp extract on alternate days as in Group II and in the last week of the study, they were exposed to X-ray as in Group III. Results: Spleen of X-ray irradiated mice showed histopathological alterations accompanied with enhanced activity of lactate dehydrogenase (LDH) in serum. Elevated levels of reactive oxygen species (ROS), lipid peroxidation (LPO), enhanced activities in Glutathione based enzymes such as Glutathione peroxidase (GSH-Px), Glutathione reductase (GR), Catalase (CAT), Superoxide dismutase (SOD) associated with depletion in reduced Glutathione (GSH) concentration were observed after X-ray exposure in blood plasma and spleen.. Pro-inflammatory cytokines like tumor necrosis factors (TNF-α) and Inteleukin-6 (IL-6) levels were also found to be enhanced in serum of irradiated mice. Irradiation-induced significant elevation in Total leucocyte counts (TLC), neutrophil counts and decline in platelet counts, associated with unaltered levels of red blood cell counts (RBC’s) and haemoglobin (Hb) in various treatment groups. Clastogenic damage and apoptosis was also found to be increase in splenic tissue of X-ray exposed mice as assessed by micronucleus and TUNEL assay. However, X-ray irradiated animals administered with Aloe vera revealed significant improvement in levels of ROS/ LPO, LDH activity, and antioxidant mechanism. Aloe vera pretreated animals exhibited less severe damage, and early recovery in micronucleated cells, hematological parameters, apoptotic cells and inflammatory markers as compared to X-ray exposed mice. Conclusion: These results indicate that the radioprotective potential of Aloe vera against X-ray induced damage. This may be due to its free radical scavenging, antioxidant, anti-apoptotic and anti-inflammatory properties.

Keywords: aloe vera, antioxidant defense system, lactate dehydrogenase (LDH), micronucleus assay, x-ray

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3515 Impact of Boundary Conditions on the Behavior of Thin-Walled Laminated Column with L-Profile under Uniform Shortening

Authors: Jaroslaw Gawryluk, Andrzej Teter

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Simply supported angle columns subjected to uniform shortening are tested. The experimental studies are conducted on a testing machine using additional Aramis and the acoustic emission system. The laminate samples are subjected to axial uniform shortening. The tested columns are loaded with the force values from zero to the maximal load destroying the L-shaped column, which allowed one to observe the column post-buckling behavior until its collapse. Laboratory tests are performed at a constant velocity of the cross-bar equal to 1 mm/min. In order to eliminate stress concentrations between sample and support, flexible pads are used. Analyzed samples are made with carbon-epoxy laminate using the autoclave method. The configurations of laminate layers are: [60,0₂,-60₂,60₃,-60₂,0₃,-60₂,0,60₂]T, where direction 0 is along the length of the profile. Material parameters of laminate are: Young’s modulus along the fiber direction - 170GPa, Young’s modulus along the fiber transverse direction - 7.6GPa, shear modulus in-plane - 3.52GPa, Poisson’s ratio in-plane - 0.36. The dimensions of all columns are: length-300 mm, thickness-0.81mm, width of the flanges-40mm. Next, two numerical models of the column with and without flexible pads are developed using the finite element method in Abaqus software. The L-profile laminate column is modeled using the S8R shell elements. The layup-ply technique is used to define the sequence of the laminate layers. However, the model of grips is made of the R3D4 discrete rigid elements. The flexible pad is consists of the C3D20R type solid elements. In order to estimate the moment of the first laminate layer damage, the following initiation criteria were applied: maximum stress criterion, Tsai-Hill, Tsai-Wu, Azzi-Tsai-Hill, and Hashin criteria. The best compliance of results was observed for the Hashin criterion. It was found that the use of the pad in the numerical model significantly influences the damage mechanism. The model without pads characterized a much more stiffness, as evidenced by a greater bifurcation load and damage initiation load in all analyzed criteria, lower shortening, and less deflection of the column in its center than the model with flexible pads. Acknowledgment: The project/research was financed in the framework of the project Lublin University of Technology-Regional Excellence Initiative, funded by the Polish Ministry of Science and Higher Education (contract no. 030/RID/2018/19).

Keywords: angle column, compression, experiment, FEM

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3514 Numerical Study of Nonlinear Guided Waves in Composite Laminates with Delaminations

Authors: Reza Soleimanpour, Ching Tai Ng

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Fibre-composites are widely used in various structures due to their attractive properties such as higher stiffness to mass ratio and better corrosion resistance compared to metallic materials. However, one serious weakness of this composite material is delamination, which is a subsurface separation of laminae. A low level of this barely visible damage can cause a significant reduction in residual compressive strength. In the last decade, the application of guided waves for damage detection has been a topic of significant interest for many researches. Among all guided wave techniques, nonlinear guided wave has shown outstanding sensitivity and capability for detecting different types of damages, e.g. cracks and delaminations. So far, most of researches on applications of nonlinear guided wave have been dedicated to isotropic material, such as aluminium and steel, while only a few works have been done on applications of nonlinear characteristics of guided waves in anisotropic materials. This study investigates the nonlinear interactions of the fundamental antisymmetric lamb wave (A0) with delamination in composite laminates using three-dimensional (3D) explicit finite element (FE) simulations. The nonlinearity considered in this study arises from interactions of two interfaces of sub-laminates at the delamination region, which generates contact acoustic nonlinearity (CAN). The aim of this research is to investigate the phenomena of CAN in composite laminated beams by a series of numerical case studies. In this study interaction of fundamental antisymmetric lamb wave with delamination of different sizes are studied in detail. The results show that the A0 lamb wave interacts with the delaminations generating CAN in the form of higher harmonics, which is a good indicator for determining the existence of delaminations in composite laminates.

Keywords: contact acoustic nonlinearity, delamination, fibre reinforced composite beam, finite element, nonlinear guided waves

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3513 Communicative Language between Doctors and Patients in Healthcare

Authors: Anita Puspawati

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A failure in obtaining informed consent from patient occurs because there is not effective communication skill in doctors. Therefore, the language is very important in communication between doctor and patient. This study uses descriptive analysis method, that is a method used mainly in researching the status of a group of people, an object, a condition, a system of thought or a class of events in the present. The result of this study indicates that the communicative language between doctors and patients will increase the trust of patients to their doctors and accordingşy, patients will provide the informed consent voluntarily.

Keywords: communicative, language, doctor, patient

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3512 Astronomical Object Classification

Authors: Alina Muradyan, Lina Babayan, Arsen Nanyan, Gohar Galstyan, Vigen Khachatryan

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We present a photometric method for identifying stars, galaxies and quasars in multi-color surveys, which uses a library of ∼> 65000 color templates for comparison with observed objects. The method aims for extracting the information content of object colors in a statistically correct way, and performs a classification as well as a redshift estimation for galaxies and quasars in a unified approach based on the same probability density functions. For the redshift estimation, we employ an advanced version of the Minimum Error Variance estimator which determines the redshift error from the redshift dependent probability density function itself. The method was originally developed for the Calar Alto Deep Imaging Survey (CADIS), but is now used in a wide variety of survey projects. We checked its performance by spectroscopy of CADIS objects, where the method provides high reliability (6 errors among 151 objects with R < 24), especially for the quasar selection, and redshifts accurate within σz ≈ 0.03 for galaxies and σz ≈ 0.1 for quasars. For an optimization of future survey efforts, a few model surveys are compared, which are designed to use the same total amount of telescope time but different sets of broad-band and medium-band filters. Their performance is investigated by Monte-Carlo simulations as well as by analytic evaluation in terms of classification and redshift estimation. If photon noise were the only error source, broad-band surveys and medium-band surveys should perform equally well, as long as they provide the same spectral coverage. In practice, medium-band surveys show superior performance due to their higher tolerance for calibration errors and cosmic variance. Finally, we discuss the relevance of color calibration and derive important conclusions for the issues of library design and choice of filters. The calibration accuracy poses strong constraints on an accurate classification, which are most critical for surveys with few, broad and deeply exposed filters, but less severe for surveys with many, narrow and less deep filters.

Keywords: VO, ArVO, DFBS, FITS, image processing, data analysis

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3511 Autonomous Learning Motivates EFL Students to Learn English at Al Buraimi University College in the Sultanate of Oman: A Case Study

Authors: Yahia A. M. AlKhoudary

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This Study presents the outcome of an investigation to evaluate the importance of autonomous learning as a means of motivation. However, very little research done in this field. Thus, the aims of this study are to ascertain the needs of the learners and to investigate their attitudes and motivation towards the mode of learning. Various suggestions made on how to improve learners’ participation in the learning process. A survey conducted on a sample group of 60 Omani College students. Self-report questionnaires and retrospective interviews conducted to find out their material-type preferences in a self-access learning context. Achieving autonomous learning system, which learners is one of the Ministry of Education goals in the Sultanate of Oman. As a result, this study presents the outcome of an investigation to evaluate the students’ performance in English as a Foreign Language (EFL). It focuses on the effect of autonomous learning that encourages students to learn English, a research conducted at Buraimi city, the Sultanate of Oman. The procedure of this investigation based on four dimensions: (1) sixty students are selected and divided into two groups, (2) pre and posttest projects are given to them, and (3) questionnaires are administered to both students who are involved in the experiment and 50 teachers (25 males and 25 females) to collect accurate data, (4) an interview with students and teachers to find out their attitude towards autonomous learning. Analysis of participants’ responses indicated that autonomous learning motivates students to learn English independently and increase the intrinsic rather than extrinsic motivation to improve their English language as a long-life active learning. The findings of this study show that autonomous learning approach is the best remedy to empower the students’ skills and overcome all relevant difficulties. They also show that secondary school teachers can fully rely on this learning approach that encourages language learners to monitor their progress, increase both learners and teachers’ motivation and ameliorate students’ behavior in the classroom. This approach is also an ongoing process, which takes time, patience and support to be lifelong learning.

Keywords: Omani, autonomous learning system, English as a Foreign Language (EFL), learning approach

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3510 Effect of Access to Finance on Innovation and Productivity of SMEs in Nigeria: Evidence from the World Bank Enterprise Survey

Authors: Abidemi C. Adegboye, Samuel Iweriebor

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The primary link between financial institutions and economic performance is the provision of resources by these institutions to businesses in order to drive enterprise expansion, sustainability, and development. In this study, the role of access to finance in driving innovations and productivity in Nigerian SMEs is investigated using the World Bank Enterprise Survey (ES) dataset. Innovation is defined based on the ES analysis using five compositions including product, method, organisational, use of foreign-licensed technology, and spending on R&D. The study considers finance in terms of source in meeting investment needs and in terms of access. Moreover, finance access is categorized as external and internal to a firm with each having different implications. The research methodology adopted a survey analysis based on the 2014 World Bank Enterprise Survey of 19 states in Nigeria. The survey comprised over 10,000 manufacturing and services firms, both at the small scale and medium scale levels. The logit estimation technique is used to estimate the relationships in the study. The results from the empirical analysis show that in general, access to finance drives SME innovation in Nigeria. In particular, ease of accessing bank loans and credit is shown to be the strongest positive force in driving all types of innovation among SMEs in Nigeria. In the same vein, the type of finance source for investment matters in terms of how it affects innovation: it is shown that both internal and external sources improve investment in product, process, and organisational innovation, but only external financing has effect on R&D spending and use of foreign licensed technology. Overall spending on R&D is only driven by access to external finance by the SMEs. For productivity, the results show that while structure of financing investment improves productivity, increased access to finance may actually lead to productivity decline among SMEs in Nigeria. There is a need for the financial system to evolve structures to increase fund availability to SMEs in Nigeria, especially for the purpose of innovation investment.

Keywords: access to finance, financing investment, innovation, productivity, SMEs

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3509 Simulation of Elastic Bodies through Discrete Element Method, Coupled with a Nested Overlapping Grid Fluid Flow Solver

Authors: Paolo Sassi, Jorge Freiria, Gabriel Usera

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In this work, a finite volume fluid flow solver is coupled with a discrete element method module for the simulation of the dynamics of free and elastic bodies in interaction with the fluid and between themselves. The open source fluid flow solver, caffa3d.MBRi, includes the capability to work with nested overlapping grids in order to easily refine the grid in the region where the bodies are moving. To do so, it is necessary to implement a recognition function able to identify the specific mesh block in which the device is moving in. The set of overlapping finer grids might be displaced along with the set of bodies being simulated. The interaction between the bodies and the fluid is computed through a two-way coupling. The velocity field of the fluid is first interpolated to determine the drag force on each object. After solving the objects displacements, subject to the elastic bonding among them, the force is applied back onto the fluid through a Gaussian smoothing considering the cells near the position of each object. The fishnet is represented as lumped masses connected by elastic lines. The internal forces are derived from the elasticity of these lines, and the external forces are due to drag, gravity, buoyancy and the load acting on each element of the system. When solving the ordinary differential equations system, that represents the motion of the elastic and flexible bodies, it was found that the Runge Kutta solver of fourth order is the best tool in terms of performance, but requires a finer grid than the fluid solver to make the system converge, which demands greater computing power. The coupled solver is demonstrated by simulating the interaction between the fluid, an elastic fishnet and a set of free bodies being captured by the net as they are dragged by the fluid. The deformation of the net, as well as the wake produced in the fluid stream are well captured by the method, without requiring the fluid solver mesh to adapt for the evolving geometry. Application of the same strategy to the simulation of elastic structures subject to the action of wind is also possible with the method presented, and one such application is currently under development.

Keywords: computational fluid dynamics, discrete element method, fishnets, nested overlapping grids

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3508 The Joy of Painless Maternity: The Reproductive Policy of the Bolsheviks in the 1930s

Authors: Almira Sharafeeva

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In the Soviet Union of the 1930s, motherhood was seen as a natural need of women. The masculine Bolshevik state did not see the emancipated woman as free from her maternal burden. In order to support the idea of "joyful motherhood," a medical discourse on the anesthesia of childbirth emerges. In March 1935 at the IX Congress of obstetricians and gynecologists the People's Commissar of Public Health of the RSFSR G.N. Kaminsky raised the issue of anesthesia of childbirth. It was also from that year that medical, literary and artistic editions with enviable frequency began to publish articles, studies devoted to the issue, the goal - to anesthetize all childbirths in the USSR - was proclaimed. These publications were often filled with anti-German and anti-capitalist propaganda, through which the advantages of socialism over Capitalism and Nazism were demonstrated. At congresses, in journals, and at institute meetings, doctors' discussions around obstetric anesthesia were accompanied by discussions of shortening the duration of the childbirth process, the prevention and prevention of disease, the admission of nurses to the procedure, and the proper behavior of women during the childbirth process. With the help of articles from medical periodicals of the 1930s., brochures, as well as documents from the funds of the Institute of Obstetrics and Gynecology of the Academy of Medical Sciences of the USSR (TsGANTD SPb) and the Department of Obstetrics and Gynecology of the NKZ USSR (GARF) in this paper we will show, how the advantages of the Soviet system and the socialist way of life were constructed through the problem of childbirth pain relief, and we will also show how childbirth pain relief in the USSR was related to the foreign policy situation and how projects of labor pain relief were related to the anti-abortion policy of the state. This study also attempts to answer the question of why anesthesia of childbirth in the USSR did not become widespread and how, through this medical procedure, the Soviet authorities tried to take control of a female function (childbirth) that was not available to men. Considering this subject from the perspective of gender studies and the social history of medicine, it is productive to use the term "biopolitics. Michel Foucault and Antonio Negri, wrote that biopolitics takes under its wing the control and management of hygiene, nutrition, fertility, sexuality, contraception. The central issue of biopolitics is population reproduction. It includes strategies for intervening in collective existence in the name of life and health, ways of subjectivation by which individuals are forced to work on themselves. The Soviet state, through intervention in the reproductive lives of its citizens, sought to realize its goals of population growth, which was necessary to demonstrate the benefits of living in the Soviet Union and to train a pool of builders of socialism. The woman's body was seen as the object over which the socialist experiment of reproductive policy was being conducted.

Keywords: labor anesthesia, biopolitics of stalinism, childbirth pain relief, reproductive policy

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3507 Internationalization Using Strategic Alliances: A Comparative Study between Family and Non-Family Businesses

Authors: Guadalupe Fuentes-Lombardo, Manuel Carlos Vallejo-Martos, Rubén Fernández-Ortiz, Miriam Cano-Rubio

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The different ways in which companies enter foreign markets, exporting their products and direct investment and using strategic alliances or not, are influenced by a series of peculiarities specific to family businesses. In these companies, different systems, such as the family, property, and business overlap; giving them unique and specific characteristics which on occasions can enhance the development of cooperation agreements and in other situations can hinder them. Previous research has shown that these companies are more likely to enter into strategic alliances with certain specific features, and are more reluctant to take part in others in which some of the advantages of the family business are put at risk, such as control of ownership and decision-making over the company by the family, among others. These arguments show that there is a wide range of interesting aspects and peculiarities in the process of internationalization of the family business, although the research objectives of this paper focus on three in particular. Our first objective will be to discover why family businesses decide to establish or not strategic alliances in their internationalization processes in comparison with other companies that are not family owned. Secondly we will be identifying the idiosyncratic aspects of family businesses that favor or hinder the use of strategic alliances as a means of entering foreign markets. Our third and final objective will be to define the types of strategic alliance most commonly used by family businesses and the reasons why they choose these particular forms of alliance rather than others. We chose these research objectives for three main reasons. Firstly because research on this subject shows that alliances are the best way to begin the international expansion process, among other reasons because they provide the partners with different kinds of resources and capacity, so increasing the probability of successful internationalization. Secondly, because family and non-family businesses are often equipped with different types of resources and strategic alliances, offer them the chance to acquire resources less frequently found in family businesses. Thirdly, because the strengths and weaknesses of these companies could affect their decisions whether or not to use strategic alliances in their international expansion process and the success achieved in these alliances. As a result, these companies prefer to enter into cooperation agreements with conditions that do not put their specific status as family companies at risk.

Keywords: family business, internationalization, strategic alliances, olive-oil and wine industry

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3506 Level of Reactive Oxygen Species and Inflammatory Cytokines in Rheumatoid Arthritis Patients: Correlation with Disease Severity

Authors: Somaiya Mateen, Shagufta Moin, Mohammad Owais, Abdul Khan, Atif Zafar

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In rheumatoid arthritis (RA), impaired oxidative metabolism and imbalance between pro-and anti-inflammatory cytokines are responsible for causing inflammation and the degradation of cartilage and bone. The present study was done to evaluate the level and hence the role of reactive oxygen species (ROS) and inflammatory cytokines in the pathogenesis of RA. The present study was performed in the blood of 80 RA patients and 55 age and sex-matched healthy controls. The level of ROS (in 5% hematocrit) and the plasma level of pro-inflammatory cytokines [TNF-α, interleukin-6 (IL-6), IL-22] and anti-inflammatory cytokines (IL-4 and IL-5) were monitored in healthy subjects and RA patients. For evaluating the role of rheumatoid factor (RF) in the pathogenesis of RA, patients were sub-divided on the basis of presence or absence of RF. Reactive species and inflammatory cytokines were correlated with disease activity measure-Disease Activity Score for 28 joints (DAS28). The level of ROS, TNF-α, IL-6 and IL-22 were found to be significantly higher in RA patients as compared to the healthy controls, with the increase being more significant in patients positive for rheumatoid factor and those having high disease severity. On the other hand, a significant decrease in the level of IL-4 and IL-10 were observed in RA patients compared with healthy controls, with the decrease being more prominent in severe cases of RA. Higher ROS (indicative of impaired anti-oxidant defence system) and pro-inflammatory cytokines level in RA patients may lead to the damage of biomolecules which in turn contributes to tissue damage and hence to the development of more severe RA. The imbalance between pro-and anti-inflammatory cytokines may lead to the development of multi-system immune complications. ROS and inflammatory cytokines may also serve as a potential biomarker for assessing the disease severity.

Keywords: rheumatoid arthritis, reactive oxygen species, pro-inflammatory cytokines, anti-inflammatory cytokines

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3505 Anti-Aging Effects of Retinol and Alpha Hydroxy Acid on Elastin Fibers of Artificially Photo-Aged Human Dermal Fibroblast Cell Lines

Authors: Mohammed Jarrar, Shalini Behl, Nadia Shaheen, Abeer Fatima, Reem Nasab

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Skin aging is a slow multifactorial process influenced by both internal as well as external factors. Ultra-violet radiations (UV), diet, smoking and personal habits are the most common environmental factors that affect skin aging. Fat contents and fibrous proteins as collagen and elastin are core internal structural components. The direct influence of UV on elastin integrity and health is crucial on aging of skin by time. The deposition of abnormal elastic material is a major marker in a photo-aged skin. Searching for compounds that may protect against cutaneous photo-damage is highly valued. Retinoids and Alpha Hydroxy Acids protective and or repairing effects of UV have been endorsed by some researchers. For consolidating a better understanding of anti and protective effects of such anti-aging agents, we evaluated the combinatory effects of various dosages of lactic acid and retinol on the dermal fibroblasts elastin levels exposed to UV. The UV exposed cells showed significant reduction in the elastin levels. A combination of drugs with a higher concentration of lactic acid (30-35 mM) and a lower concentration of retinol (10-15mg/mL) showed to work better in enhancing elastin concentration in UV exposed cells. We assume this enhancement could be the result of increased tropo-elastin gene expression stimulated by retinol and lactic acid probably repaired the UV irradiated damage by enhancing the amount and integrity of the elastin fibers.

Keywords: alpha hydroxy acid, elastin, retinol, ultraviolet radiations

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3504 Non-Destructive Testing of Carbon Fiber Reinforced Plastic by Infrared Thermography Methods

Authors: W. Swiderski

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Composite materials are one answer to the growing demand for materials with better parameters of construction and exploitation. Composite materials also permit conscious shaping of desirable properties to increase the extent of reach in the case of metals, ceramics or polymers. In recent years, composite materials have been used widely in aerospace, energy, transportation, medicine, etc. Fiber-reinforced composites including carbon fiber, glass fiber and aramid fiber have become a major structural material. The typical defect during manufacture and operation is delamination damage of layered composites. When delamination damage of the composites spreads, it may lead to a composite fracture. One of the many methods used in non-destructive testing of composites is active infrared thermography. In active thermography, it is necessary to deliver energy to the examined sample in order to obtain significant temperature differences indicating the presence of subsurface anomalies. To detect possible defects in composite materials, different methods of thermal stimulation can be applied to the tested material, these include heating lamps, lasers, eddy currents, microwaves or ultrasounds. The use of a suitable source of thermal stimulation on the test material can have a decisive influence on the detection or failure to detect defects. Samples of multilayer structure carbon composites were prepared with deliberately introduced defects for comparative purposes. Very thin defects of different sizes and shapes made of Teflon or copper having a thickness of 0.1 mm were screened. Non-destructive testing was carried out using the following sources of thermal stimulation, heating lamp, flash lamp, ultrasound and eddy currents. The results are reported in the paper.

Keywords: Non-destructive testing, IR thermography, composite material, thermal stimulation

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3503 Towards Intercultural Competence in EFL Textbook: the Case of ‘New Prospects’

Authors: Kamilia Mebarki

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The promotion of intercultural competence plays an important role in foreign language education. The outcome of intercultural educationalists‟ studies was the adoption of intercultural language learning and a modified version of the Communicative Competence that encompasses an intercultural component enabling language learners to communicate successfully interculturally. Intercultural Competencehas an even more central role in teaching English as a foreign language (EFL) since efforts are critical to preparing learners for intercultural communisation in our global world. In these efforts, EFL learning materials are a crucial stimulus for developing learners’ intercultural competence. There has been a continuous interest in the analysis of EFL textbooks by researcher all over the world. One specific area that has received prominent attention in recent years is a focus on how the cultural content of EFL materials promote intercultural competence. In the Algerian context, research on the locally produced EFL textbooks tend to focus on investigating the linguistic and communicative competence. The cultural content of the materials has not yet been systematically researched. Therefore, this study contributes to filling this gap by evaluating the locally published EFL textbook ‘New Prospects’ used at the high school level as well as investigating teachers’ views and attitudes on the cultural content of ‘New Prospects’ alongside two others locally produced EFL textbooks ‘Getting Through’ and ‘At the Crossroad’ used at high school level. To estimate the textbook’s potential of developing intercultural competence, mixed methods, a combination of quantitative and qualitative data collection, was used in the material evaluation analysed via content analysis and in the survey questionnaire and interview with teachers.Data collection and analysis were supported by the frameworks developed by the researcher for analysing the textbook, questionnaire, and interview. Indeed, based on the literature, three frameworks/ models are developed in this study to analyse, on one hand, the cultural contexts and themes discussed in the material that play an important role in fostering learners’ intercultural awareness. On the other hand, to evaluate the promotion of developing intercultural competence.

Keywords: intercultural communication, intercultural communicative competence, intercultural competence, EFL materials

Procedia PDF Downloads 89
3502 Timing Equation for Capturing Satellite Thermal Images

Authors: Toufic Abd El-Latif Sadek

Abstract:

The Asphalt object represents the asphalted areas, like roads. The best original data of thermal images occurred at a specific time during the days of the year, by preventing the gaps in times which give the close and same brightness from different objects, using seven sample objects, asphalt, concrete, metal, rock, dry soil, vegetation, and water. It has been found in this study a general timing equation for capturing satellite thermal images at different locations, depends on a fixed time the sunrise and sunset; Capture Time= Tcap =(TM*TSR) ±TS.

Keywords: asphalt, satellite, thermal images, timing equation

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3501 Physical, Iconographic and Symbolic Features of the Plectrum Some Reflections on Sound Production in Ancient Greek String Instruments

Authors: Felipe Aguirre

Abstract:

In this paper some of the relevant features of the πλῆκτρον within GrecoLatin tradition will be analyzed. Starting from the formal aspects (shape, materials, technical properties) and the archaeological evidence, some of its symbolic implications that emerge in the light of literary and iconographic analysis will be discussed. I shall expose that, in addition to fulfilling a purely physical function within the process of sound production, the πλῆκτρον was the object of a rich imaginery that provided it with an allegorical, metaphorical-poetic and even metaphysical dimension.

Keywords: musicology, ethnomusicology, ancient greek music, plectrum, stringed instruments

Procedia PDF Downloads 135
3500 Laboratory Evaluation of Asphalt Concrete Prepared with Over Burnt Brick Aggregate Treated by Zycosoil

Authors: D. Sarkar, M. Pal, A. K. Sarkar

Abstract:

Asphaltic concrete for pavement construction in India are produced by using crushed stone, gravels etc. as aggregate. In north-Eastern region of India, there is a scarcity o f stone aggregate. Therefore the road engineers are always in search of an optional material as aggregate which can replace the regularly used material. The purpose of this work was to evaluate the utilization of substandard or marginal aggregates in flexible pavement construction. The investigation was undertaken to evaluate the effects of using lower quality aggregates such as over burnt brick aggregate on the preparation of asphalt concrete for flexible pavements. The scope of this work included a review of available literature and existing data, a laboratory evaluation organized to determine the effects of marginal aggregates and potential techniques to upgrade these substandard materials, and a laboratory evaluation of these upgraded marginal aggregate asphalt mixtures. Over burnt brick aggregates are water susceptible and can leads to moisture damage. Moisture damage is the progressive loss of functionality of the material owing to loss of the adhesion bond between the asphalt binder and the aggregate surface. Hence, zycosoil as an anti striping additive were evaluated in this study. This study summarizes the results of the laboratory evaluation carried out to investigate the properties of asphalt concrete prepared with zycosoil modified over burnt brick aggregate. Marshall specimen were prepared with stone aggregate, zycosoil modified stone aggregate, over burnt brick aggregate and zycosoil modified over burnt brick aggregate. Results show that addition of zycosoil with stone aggregate increased stability by 6% and addition of zycosoil with over burnt brick aggregate increased stability by 30%.

Keywords: asphalt concrete, over burnt brick aggregate, marshall stability, zycosoil

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3499 Mothers and Moneymakers: A Case Study of How Citizen-Women Shape U.S. Marriage Migration Politics Online

Authors: Gina Longo

Abstract:

Social media, internet technology, and affordable travel have created avenues like tourism and internet chatrooms for Western women to meet foreign partners without paid, third-party intermediaries in regions like the Middle East/North Africa (MENA) and Sub-Saharan Africa (SSA), where men from mid-level developing countries meet and marry Western women and try to relocate. Foreign nationals who marry U.S. citizens have an expedited track to naturalization. U.S. immigration officials require that “green card” petitioning couples demonstrate that their relationships are “valid and subsisting” (i.e., for love) and not fraudulent (i.e., for immigration papers). These requirements are ostensibly gender- and racially-neutral, but migration itself is not; black and white women petitioners who seek partners from these regions and solicit advice from similar others about the potential obstacles to their petitions’ success online. Using an online ethnography and textual analysis of conversation threads on a large on-line immigration forum where U.S. petitioners exchange such information, this study examines how gendered and racialized standards of legitimacy are applied to family and sexuality and used discursively online among women petitioners differently to achieve “genuineness” and define “red flags” indicating potential marriage fraud. This paper argues that forum-women members police immigration requests even before cases reach an immigration officer, and use this social media platform to reconstruct gendered and racialized hierarchies of U.S. citizenship. Women petitioners use the formal criteria of U.S. immigration in ways that reveal gender and racial ideologies, expectations for conformity to a gendered hegemonic family ideal, and policing of women’s sexual agency, fertility, and desirability. These intersectional norms shape their online discussions about the suitability of marriages and of the migration of non-citizen male partners of color to the United States.

Keywords: marriage fraud, migration, online forums, women

Procedia PDF Downloads 113
3498 Maresin Like 1 Treatment: Curbing the Pathogenesis of Behavioral Dysfunction and Neurodegeneration in Alzheimer's Disease Mouse Model

Authors: Yan Lu, Song Hong, Janakiraman Udaiyappan, Aarti Nagayach, Quoc-Viet A. Duong, Masao Morita, Shun Saito, Yuichi Kobayashi, Yuhai, Zhao, Hongying Peng, Nicholas B. Pham, Walter J Lukiw, Christopher A. Vuong, Nicolas G. Bazan

Abstract:

Aims: Neurodegeneration and behavior dysfunction occurs in patients with Alzheimer's Disease (AD), and as the disease progresses many patients develop cognitive impairment. 5XFAD mouse model of AD is widely used to study AD pathogenesis and treatment. This study aimed to investigate the effect of maresin like 1 (MaR-L1) treatment in AD pathology using 5XFAD mice. Methods: We tested 12-month-old male 5XFAD mice and wild type control mice treated with MaR-L1 in a battery of behavioral tasks. We performed open field test, beam walking test, clasping test, inverted grid test, acetone test, marble burring test, elevated plus maze test, cross maze test and novel object recognition test. We also studied neuronal loss, amyloid β burden, and inflammation in the brains of 5XFAD mice using immunohistology and Western blotting. Results: MaR-L1 treatment to the 5XFAD mice showed improved cognitive function of 5XFAD mice. MaR-L1 showed decreased anxiety behavior in open field test and marble burring test, increased muscular strength in the beam walking test, clasping test and inverted grid test. Cognitive function was improved in MaR-L1 treated 5XFAD mice in the novel object recognition test. MaR-L1 prevented neuronal loss and aberrant inflammation. Conclusion: Our finding suggests that behavioral abnormalities were normalized by the administration of MaR-L1 and the neuroprotective role of MaR-L1 in the AD. It also indicates that MaR-L1 treatment is able to prevent and or ameliorate neuronal loss and aberrant inflammation. Further experiments to validate the results are warranted using other AD models in the future.

Keywords: Alzheimer's disease, motor and cognitive behavior, 5XFAD mice, Maresin Like 1, microglial cell, astrocyte, neurodegeneration, inflammation, resolution of inflammation

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3497 Mobile Learning and Student Engagement in English Language Teaching: The Case of First-Year Undergraduate Students at Ecole Normal Superieur, Algeria

Authors: I. Tiahi

Abstract:

The aim of the current paper is to explore educational practices in contemporary Algeria. Researches explain such practices bear traditional approach and the overlooks modern teaching methods such as mobile learning. That is why the research output of examining student engagement in respect of mobile learning was obtained from the following objectives: (1) To evaluate the current practice of English language teaching within Algerian higher education institutions, (2) To explore how social constructivism theory and m-learning help students’ engagement in the classroom and (3) To explore the feasibility and acceptability of m-learning amongst institutional leaders. The methodology underpins a case study and action research. For the case study, the researcher engaged with 6 teachers, 4 institutional leaders, and 30 students subjected for semi-structured interviews and classroom observations to explore the current teaching methods for English as a foreign language. For the action research, the researcher applied an intervention course to investigate the possibility and implications for future implementation of mobile learning in higher education institutions. The results were deployed using thematic analysis. The research outcome showed that the disengagement of students in English language learning has many aspects. As seen from the interviews from the teachers, the researcher found that they do not have enough resources except for using ppt for some teacher. According to them, the teaching method they are using is mostly communicative and competency-based approach. Teachers informed that students are disengaged because they have psychological barriers. In classroom setting, the students are conscious about social approval from the peer, and thus if they are to face negative reinforcement which would damage their image, it is seen as a preventive mechanism to be scared of committing mistakes. This was also very reflective in this finding. A lot of other arguments can be given for this claim; however, in Algerian setting, it is usual practice where teachers do not provide positive reinforcement which is open up students for possible learning. Thus, in order to overcome such a psychological barrier, proper measures can be taken. On a conclusive remark, it is evident that teachers, students, and institutional leaders provided positive feedback for using mobile learning. It is not only motivating but also engaging in learning processes. Apps such as Kahoot, Padlet and Slido were well received and thus can be taken further to examine its higher impact in Algerian context. Thus, in the future, it will be important to implement m-learning effectively in higher education to transform the current traditional practices into modern, innovative and active learning. Persuasion for this change for stakeholder may be challenging; however, its long-term benefits can be reflective from the current research paper.

Keywords: Algerian context, mobile learning, social constructivism, student engagement

Procedia PDF Downloads 133
3496 Experimental and Numerical Investigation of Fracture Behavior of Foamed Concrete Based on Three-Point Bending Test of Beams with Initial Notch

Authors: M. Kozłowski, M. Kadela

Abstract:

Foamed concrete is known for its low self-weight and excellent thermal and acoustic properties. For many years, it has been used worldwide for insulation to foundations and roof tiles, as backfill to retaining walls, sound insulation, etc. However, in the last years it has become a promising material also for structural purposes e.g. for stabilization of weak soils. Due to favorable properties of foamed concrete, many interests and studies were involved to analyze its strength, mechanical, thermal and acoustic properties. However, these studies do not cover the investigation of fracture energy which is the core factor governing the damage and fracture mechanisms. Only limited number of publications can be found in literature. The paper presents the results of experimental investigation and numerical campaign of foamed concrete based on three-point bending test of beams with initial notch. First part of the paper presents the results of a series of static loading tests performed to investigate the fracture properties of foamed concrete of varying density. Beam specimens with dimensions of 100×100×840 mm with a central notch were tested in three-point bending. Subsequently, remaining halves of the specimens with dimensions of 100×100×420 mm were tested again as un-notched beams in the same set-up with reduced distance between supports. The tests were performed in a hydraulic displacement controlled testing machine with a load capacity of 5 kN. Apart from measuring the loading and mid-span displacement, a crack mouth opening displacement (CMOD) was monitored. Based on the load – displacement curves of notched beams the values of fracture energy and tensile stress at failure were calculated. The flexural tensile strength was obtained on un-notched beams with dimensions of 100×100×420 mm. Moreover, cube specimens 150×150×150 mm were tested in compression to determine the compressive strength. Second part of the paper deals with numerical investigation of the fracture behavior of beams with initial notch presented in the first part of the paper. Extended Finite Element Method (XFEM) was used to simulate and analyze the damage and fracture process. The influence of meshing and variation of mechanical properties on results was investigated. Numerical models simulate correctly the behavior of beams observed during three-point bending. The numerical results show that XFEM can be used to simulate different fracture toughness of foamed concrete and fracture types. Using the XFEM and computer simulation technology allow for reliable approximation of load–bearing capacity and damage mechanisms of beams made of foamed concrete, which provides some foundations for realistic structural applications.

Keywords: foamed concrete, fracture energy, three-point bending, XFEM

Procedia PDF Downloads 296
3495 Identifying Necessary Words for Understanding Academic Articles in English as a Second or a Foreign Language

Authors: Stephen Wagman

Abstract:

This paper identifies three common structures in English sentences that are important for understanding academic texts, regardless of the characteristics or background of the readers or whether they are reading English as a second or a foreign language. Adapting a model from the Humanities, the explication of texts used in literary studies, the paper analyses sample sentences to reveal structures that enable the reader not only to decide which words are necessary for understanding the main ideas but to make the decision without knowing the meaning of the words. By their very syntax noun structures point to the key word for understanding them. As a rule, the key noun is followed by easily identifiable prepositions, relative pronouns, or verbs and preceded by single adjectives. With few exceptions, the modifiers are unnecessary for understanding the idea of the sentence. In addition, sentences are often structured by lists in which the items frequently consist of parallel groups of words. The principle of a list is that all the items are similar in meaning and it is not necessary to understand all of the items to understand the point of the list. This principle is especially important when the items are long or there is more than one list in the same sentence. The similarity in meaning of these items enables readers to reduce sentences that are hard to grasp to an understandable core without excessive use of a dictionary. Finally, the idea of subordination and the identification of the subordinate parts of sentences through connecting words makes it possible for readers to focus on main ideas without having to sift through the less important and more numerous secondary structures. Sometimes a main idea requires a subordinate one to complete its meaning, but usually, subordinate ideas are unnecessary for understanding the main point of the sentence and its part in the development of the argument from sentence to sentence. Moreover, the connecting words themselves indicate the functions of the subordinate structures. These most frequently show similarity and difference or reasons and results. Recognition of all of these structures can not only enable students to read more efficiently but to focus their attention on the development of the argument and this rather than a multitude of unknown vocabulary items, the repetition in lists, or the subordination in sentences are the one necessary element for comprehension of academic articles.

Keywords: development of the argument, lists, noun structures, subordination

Procedia PDF Downloads 242
3494 Snake Locomotion: From Sinusoidal Curves and Periodic Spiral Formations to the Design of a Polymorphic Surface

Authors: Ennios Eros Giogos, Nefeli Katsarou, Giota Mantziorou, Elena Panou, Nikolaos Kourniatis, Socratis Giannoudis

Abstract:

In the context of the postgraduate course Productive Design, Department of Interior Architecture of the University of West Attica in Athens, under the guidance of Professors Nikolaos Koyrniatis and Socratis Giannoudis, kinetic mechanisms with parametric models were examined for their further application in the design of objects. In the first phase, the students studied a motion mechanism that they chose from daily experience and then analyzed its geometric structure in relation to the geometric transformations that exist. In the second phase, the students tried to design it through a parametric model in Grasshopper3d for Rhino algorithmic processor and plan the design of its application in an everyday object. For the project presented, our team began by studying the movement of living beings, specifically the snake. By studying the snake and the role that the environment has in its movement, four basic typologies were recognized: serpentine, concertina, sidewinding and rectilinear locomotion, as well as its ability to perform spiral formations. Most typologies are characterized by ripples, a series of sinusoidal curves. For the application of the snake movement in a polymorphic space divider, the use of a coil-type joint was studied. In the Grasshopper program, the simulation of the desired motion for the polymorphic surface was tested by applying a coil on a sinusoidal curve and a spiral curve. It was important throughout the process that the points corresponding to the nodes of the real object remain constant in number, as well as the distances between them and the elasticity of the construction had to be achieved through a modular movement of the coil and not some elastic element (material) at the nodes. Using mesh (repeating coil), the whole construction is transformed into a supporting body and combines functionality with aesthetics. The set of elements functions as a vertical spatial network, where each element participates in its coherence and stability. Depending on the positions of the elements in terms of the level of support, different perspectives are created in terms of the visual perception of the adjacent space. For the implementation of the model on the scale (1:3), (0.50m.x2.00m.), the load-bearing structure that was studied has aluminum rods for the basic pillars Φ6mm and Φ 2.50 mm, for the secondary columns. Filling elements and nodes are of similar material and were made of MDF surfaces. During the design process, four trapezoidal patterns were picketed, which function as filling elements, while in order to support their assembly, a different engraving facet was done. The nodes have holes that can be pierced by the rods, while their connection point with the patterns has a half-carved recess. The patterns have a corresponding recess. The nodes are of two different types depending on the column that passes through them. The patterns and knots were designed to be cut and engraved using a Laser Cutter and attached to the knots using glue. The parameters participate in the design as mechanisms that generate complex forms and structures through the repetition of constantly changing versions of the parts that compose the object.

Keywords: polymorphic, locomotion, sinusoidal curves, parametric

Procedia PDF Downloads 99
3493 Night Shift Work as an Oxidative Stressor: A Systematic Review

Authors: Madeline Gibson

Abstract:

Night shift workers make up an essential part of the modern workforce. However, night shift workers have higher incidences of late in life diseases and earlier mortality. Night shift workers are exposed to constant light and experience circadian rhythm disruption. Sleep disruption is thought to increase oxidative stress, defined as an imbalance of excess pro-oxidative factors and reactive oxygen species over anti-oxidative activity. Oxidative stress can damage cells, proteins and DNA and can eventually lead to varied chronic diseases such as cancer, diabetes, cardiovascular disease, Alzheimer’s and dementia. This review aimed to understand whether night shift workers were at greater risk of oxidative stress and to contribute to a consensus on this relationship. Twelve studies published in 2001-2019 examining 2,081 workers were included in the review. Studies compared both the impact of working a single shift and in comparisons between those who regularly work night shifts and only day shifts. All studies had evidence to support this relationship across a range of oxidative stress indicators, including increased DNA damage, reduced DNA repair capacity, increased lipid peroxidation, higher levels of reactive oxygen species, and to a lesser extent, a reduction in antioxidant defense. This research supports the theory that melatonin and the sleep-wake cycle mediate the relationship between shift work and oxidative stress. It is concluded that night shift work increases the risk for oxidative stress and, therefore, future disease. Recommendations are made to promote the long-term health of shift workers considering these findings.

Keywords: night shift work, coxidative stress, circadian rhythm, melatonin, disease, circadian rhythm disruption

Procedia PDF Downloads 258
3492 Elastic Collisions of Electrons with DNA and Water From 10 eV to 100 KeV: Scar Macro Investigation

Authors: Aouina Nabila Yasmina, Zine El Abidine Chaoui

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Recently, understanding the interactions of electrons with the DNA molecule and its components has attracted considerable interest because DNA is the main site damaged by ionizing radiation. The interactions of radiation with DNA induce a variety of molecular damage such as single-strand breaks, double-strand breaks, basic damage, cross-links between proteins and DNA, and others, or the formation of free radicals, which, by chemical reactions with DNA, can also lead to breakage of the strand. One factor that can contribute significantly to these processes is the effect of water hydration on the formation and reaction of radiation induced by these radicals in and / or around DNA. B-DNA requires about 30% by weight of water to maintain its native conformation in the crystalline state. The transformation depends on various factors such as sequence, ion composition, concentration and water activity. Partial dehydration converts it to DNA-A. The present study shows the results of theoretical calculations for positrons and electrons elastic scattering with DNA medium and water over a broad energy range from 10 eV to 100 keV. Indeed, electron elastic cross sections and elastic mean free paths are calculated using a corrected form of the independent atom method, taking into account the geometry of the biomolecule (SCAR macro). Moreover, the elastic scattering of electrons and positrons by atoms of the biomolecule was evaluated by means of relativistic (Dirac) partial wave analysis. Our calculated results are compared with theoretical data available in the literature in the absence of experimental data, in particular for positron. As a central result, our electron elastic cross sections are in good agreement with existing theoretical data in the range of 10 eV to 1 keV.

Keywords: elastic cross scrion, elastic mean free path, scar macro method, electron collision

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3491 Exploring the Use of Drones for Corn Borer Management: A Case Study in Central Italy

Authors: Luana Centorame, Alessio Ilari, Marco Giustozzi, Ester Foppa Pedretti

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Maize is one of the most important agricultural cash crops in the world, involving three different chains: food, feed, and bioenergy production. Nowadays, the European corn borer (ECB), Ostrinia nubilalis, to the best of the author's knowledge, is the most important pest to control for maize growers. The ECB is harmful to maize; young larvae are responsible for minor damage to the leaves, while the most serious damage is tunneling by older larvae that burrow into the stock. Soon after, larvae can affect cobs, and it was found that ECB can foster mycotoxin contamination; this is why it is crucial to control it. There are multiple control methods available: agronomic, biological, and microbiological means, agrochemicals, and genetically modified plants. Meanwhile, the European Union’s policy focuses on the transition to sustainable supply chains and translates into the goal of reducing the use of agrochemicals by 50%. The current work aims to compare the agrochemical treatment of ECB and biological control through beneficial insects released by drones. The methodology used includes field trials of both chemical and biological control, considering a farm in central Italy as a case study. To assess the mechanical and technical efficacy of drones with respect to standard machinery, the available literature was consulted. The findings are positive because drones allow them to get in the field promptly, in difficult conditions and with lower costs if compared to traditional techniques. At the same time, it is important to consider the limits of drones regarding pilot certification, no-fly zones, etc. In the future, it will be necessary to deepen the topic with the real application in the field of both systems, expanding the scenarios in which drones can be used and the type of material distributed.

Keywords: beneficial insects, corn borer management, drones, precision agriculture

Procedia PDF Downloads 97
3490 Innovative Technologies of Distant Spectral Temperature Control

Authors: Leonid Zhukov, Dmytro Petrenko

Abstract:

Optical thermometry has no alternative in many cases of industrial most effective continuous temperature control. Classical optical thermometry technologies can be used on available for pyrometers controlled objects with stable radiation characteristics and transmissivity of the intermediate medium. Without using temperature corrections, it is possible in the case of a “black” body for energy pyrometry and the cases of “black” and “grey” bodies for spectral ratio pyrometry or with using corrections – for any colored bodies. Consequently, with increasing the number of operating waves, optical thermometry possibilities to reduce methodical errors significantly expand. That is why, in recent 25-30 years, research works have been reoriented on more perfect spectral (multicolor) thermometry technologies. There are two physical material substances, i.e., substance (controlled object) and electromagnetic field (thermal radiation), to be operated in optical thermometry. Heat is transferred by radiation; therefore, radiation has the energy, entropy, and temperature. Optical thermometry was originating simultaneously with the developing of thermal radiation theory when the concept and the term "radiation temperature" was not used, and therefore concepts and terms "conditional temperatures" or "pseudo temperature" of controlled objects were introduced. They do not correspond to the physical sense and definitions of temperature in thermodynamics, molecular-kinetic theory, and statistical physics. Launched by the scientific thermometric society, discussion about the possibilities of temperature measurements of objects, including colored bodies, using the temperatures of their radiation is not finished. Are the information about controlled objects transferred by their radiation enough for temperature measurements? The positive and negative answers on this fundamental question divided experts into two opposite camps. Recent achievements of spectral thermometry develop events in her favour and don’t leave any hope for skeptics. This article presents the results of investigations and developments in the field of spectral thermometry carried out by the authors in the Department of Thermometry and Physics-Chemical Investigations. The authors have many-year’s of experience in the field of modern optical thermometry technologies. Innovative technologies of optical continuous temperature control have been developed: symmetric-wave, two-color compensative, and based on obtained nonlinearity equation of spectral emissivity distribution linear, two-range, and parabolic. Тhe technologies are based on direct measurements of physically substantiated and proposed by Prof. L. Zhukov, radiation temperatures with the next calculation of the controlled object temperature using this radiation temperatures and corresponding mathematical models. Тhe technologies significantly increase metrological characteristics of continuous contactless and light-guide temperature control in energy, metallurgical, ceramic, glassy, and other productions. For example, under the same conditions, the methodical errors of proposed technologies are less than the errors of known spectral and classical technologies in 2 and 3-13 times, respectively. Innovative technologies provide quality products obtaining at the lowest possible resource-including energy costs. More than 600 publications have been published on the completed developments, including more than 100 domestic patents, as well as 34 patents in Australia, Bulgaria, Germany, France, Canada, the USA, Sweden, and Japan. The developments have been implemented in the enterprises of USA, as well as Western Europe and Asia, including Germany and Japan.

Keywords: emissivity, radiation temperature, object temperature, spectral thermometry

Procedia PDF Downloads 94