Search results for: magnetic attraction force
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3764

Search results for: magnetic attraction force

1514 Preparation of Core-Shell AgBr/Cationic Polymer Nanocomposite with Dual Biocidal Modes and Sustained Release of Ag+ Ions

Authors: Rongzhou Wang

Abstract:

Research on designing nano-antibacterial agent with potent and long-lasting antibacterial property is demanding and provoking work. In this study, a core-shell AgBr/cationic polymer nanocomposite (AgBr/NPVP-H10) were synthesized and its structure confirmed by Fourier Transform Infrared Spectrometer (FT-IR), Nuclear Magnetic Resonance (1H NMR) and X-ray diffraction (XRD), and the cationic polymer contents were determined with Thermal Gravimetric Analyzer (TGA). The morphology was directly observed by Transmission Electron Microscope (TEM) which showed that the nanoparticle contains single core and organic shell and had an average diameter of 30.1 nm. The antibacterial test against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli illuminated that this nanocomposite had potent bactericidal activity, which can be attributed to the contact-killing of cationic polymers and releasing-killing of Ag+ ions. In addition, cationic polymer encapsulating AgBr cores gave the resin discs sustained release of Ag+ ions, which may result in long-lasting bactericidal activity. The AgBr/NPVP-H10 nanoparticle with the dual bactericidal capability and long term antimicrobial effect is a promising material aimed at preventing bacterial infection.

Keywords: core-shell nanocomposite, cationic polymer, dual antibacterial capability, long-lasting antibacterial activity

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1513 Usability Assessment of a Bluetooth-Enabled Resistance Exercise Band among Young Adults

Authors: Lillian M. Seo, Curtis L. Petersen, Ryan J. Halter, David Kotz, John A. Batsis

Abstract:

Background: Resistance-based exercises effectively enhance muscle strength, which is especially important in older populations as it reduces the risk of disability. Our group developed a Bluetooth-enabled handle for resistance exercise bands that wirelessly transmits relative force data through low-energy Bluetooth to a local smartphone or similar device. The system has the potential to measure home-based exercise interventions, allowing health professionals to monitor compliance. Its feasibility has already been demonstrated in both clinical and field-based settings, but it remained unclear whether the system’s usability persisted upon repeated use. The current study sought to assess the usability of this system and its users’ satisfaction with repeated use by deploying the device among younger adults to gather formative information that can ultimately improve the device’s design for older adults. Methods: A usability study was conducted in which 32 participants used the above system. Participants executed 10 repetitions of four commonly performed exercises: bicep flexion, shoulder abduction, elbow extension, and triceps extension. Each completed three exercise sessions, separated by at least 24 hours to minimize muscle fatigue. At its conclusion, subjects completed an adapted version of the usefulness, satisfaction, and ease (USE) questionnaire – assessing the system across four domains: usability, satisfaction, ease of use, and ease of learning. The 20-item questionnaire examined how strongly a participant agrees with positive statements about the device on a seven-point Likert scale, with one representing ‘strongly disagree’ and seven representing ‘strongly agree.’ Participants’ data were aggregated to calculate mean response values for each question and domain, effectively assessing the device’s performance across different facets of the user experience. Summary force data were visualized using a custom web application. Finally, an optional prompt at the end of the questionnaire allowed for written comments and feedback from participants to elicit qualitative indicators of usability. Results: Of the n=32 participants, 13 (41%) were female; their mean age was 32.4 ± 11.8 years, and no participants had a physical impairment. No usability questions received a mean score < 5 of seven. The four domains’ mean scores were: usefulness 5.66 ± 0.35; satisfaction 6.23 ± 0.06; ease of use 6.25 ± 0.43; and ease of learning 6.50 ± 0.19. Representative quotes of the open-ended feedback include: ‘A non-rigid strap-style handle might be useful for some exercises,’ and, ‘Would need different bands for each exercise as they use different muscle groups with different strength levels.’ General impressions were favorable, supporting the expectation that the device would be a useful tool in exercise interventions. Conclusions: A simple usability assessment of a Bluetooth-enabled resistance exercise band supports a consistent and positive user experience among young adults. This study provides adequate formative data, assuring the next steps can be taken to continue testing and development for the target population of older adults.

Keywords: Bluetooth, exercise, mobile health, mHealth, usability

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1512 A Correlative Study of Heating Values of Saw Dust and Rice Husks in the Thermal Generation of Electricity

Authors: Muhammad Danladi, Muhammad Bura Garba, Muhammad Yahaya, Dahiru Muhammad

Abstract:

Biomass is one of the primary sources of energy supply, which contributes to about 78% of Nigeria. In this work, a comparative analysis of the heating values of sawdust and rice husks in the thermal generation of electricity was carried out. In the study, different masses of biomass were used and the corresponding electromotive force in millivolts was obtained. A graph of e.m.f was plotted against the mass of each biomass and a gradient was obtained. Bar graphs were plotted to represent the values of e.m.f and masses of the biomass. Also, a graph of e.m.f against eating values of sawdust and rice husks was plotted, and in each case, as the e.m.f increases also, the heating values increases. The result shows that saw dust with 0.033Mv/g gradient and 3.5 points of intercept had the highest gradient, followed by rice husks with 0.026Mv/g gradient and 2.6 points of intercept. It is, therefore, concluded that sawdust is the most efficient of the two types of biomass in the thermal generation of electricity.

Keywords: biomass, electricity, thermal, generation

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1511 Peeling Behavior of Thin Elastic Films Bonded to Rigid Substrate of Random Surface Topology

Authors: Ravinu Garg, Naresh V. Datla

Abstract:

We study the fracture mechanics of peeling of thin films perfectly bonded to a rigid substrate of any random surface topology using an analytical formulation. A generalized theoretical model has been developed to determine the peel strength of thin elastic films. It is demonstrated that an improvement in the peel strength can be achieved by modifying the surface characteristics of the rigid substrate. Characterization study has been performed to analyze the effect of different parameters on effective peel force from the rigid surface. Different surface profiles such as circular and sinusoidal has been considered to demonstrate the bonding characteristics of film-substrate interface. Condition for the instability in the debonding of the film is analyzed, where the localized self-debonding arises depending upon the film and surface characteristics. This study is towards improved adhesion strength of thin films to rigid substrate using different textured surfaces.

Keywords: debonding, fracture mechanics, peel test, thin film adhesion

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1510 Enhancement of Cement Mortar Mechanical Properties with Replacement of Seashell Powder

Authors: Abdoullah Namdar, Fadzil Mat Yahaya

Abstract:

Many synthetic additives have been using for improve cement mortar and concrete characteristics, but natural additive is a friendly environment option. The quantity of (2% and 4%) seashell powder has been replaced in cement mortar, and compared with plain cement mortar in early age of 7 days. The strain gauges have been installed on beams and cube, for monitoring fluctuation of flexural and compressive strength. Main objective of this paper is to study effect of linear static force on flexural and compressive strength of modified cement mortar. The results have been indicated that the replacement of appropriate proportion of seashell powder enhances cement mortar mechanical properties. The replacement of 2% seashell causes improvement of deflection, time to failure and maximum load to failure on concrete beam and cube, the same occurs for compressive modulus elasticity. Increase replacement of seashell to 4% reduces all flexural strength, compressive strength and strain of cement mortar.

Keywords: compressive strength, flexural strength, compressive modulus elasticity, time to failure, deflection

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1509 Nanostructural Analysis of the Polylactic Acid (PLA) Fibers Functionalized by RF Plasma Treatment

Authors: J. H. O. Nascimento, F. R. Oliveira, K. K. O. S. Silva, J. Neves, V. Teixeira, J. Carneiro

Abstract:

These the aliphatic polyesters such as Polylactic Acid (PLA) in the form of fibers, nanofibers or plastic films, generally possess chemically inert surfaces, free porosity, and surface free energy (ΔG) lesser than 32 mN/m. It is therefore considered a low surface energy material, consequently has a low work of adhesion. For this reason, the products manufactured using these polymers are often subjected to surface treatments in order to change its physic-chemical surface, improving their wettability and the Work of Adhesion (WA). Plasma Radio Frequency low pressure (RF) treatment was performed in order to improve the Work of Adhesion (WA) on PLA fibers. Different parameters, such as, power, ratio of working gas (Argon/Oxygen) and treatment time were used to optimize the plasma conditions to modify the PLA surface properties. With plasma treatment, a significant increase in the work of adhesion on PLA fiber surface was observed. The analysis performed by XPS showed an increase in polar functional groups and the SEM and AFM image revealed a considerable increase in roughness.

Keywords: RF plasma, surface modification, PLA fabric, atomic force macroscopic, Nanotechnology

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1508 Stability and Performance Improvement of a Two-Degree-of-Freedom Robot under Interaction Using the Impedance Control

Authors: Seyed Reza Mirdehghan, Mohammad Reza Haeri Yazdi

Abstract:

In this paper, the stability and the performance of a two-degree-of-freedom robot under an interaction with a unknown environment has been investigated. The time when the robot returns to its initial position after an interaction and the primary resistance of the robot against the impact must be reduced. Thus, the applied torque on the motor will be reduced. The impedance control is an appropriate method for robot control in these conditions. The stability of the robot at interaction moment was transformed to be a robust stability problem. The dynamic of the unknown environment was modeled as a weight function and the stability of the robot under an interaction with the environment has been investigated using the robust control concept. To improve the performance of the system, a force controller has been designed which the normalized impedance after interaction has been reduced. The resistance of the robot has been considered as a normalized cost function and its value was 0.593. The results has showed reduction of resistance of the robot against impact and the reduction of convergence time by lower than one second.

Keywords: impedance control, control system, robots, interaction

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1507 Molecular Migration in Polyvinyl Acetate Matrix: Impact of Compatibility, Number of Migrants and Stress on Surface and Internal Microstructure

Authors: O. Squillace, R. L. Thompson

Abstract:

Migration of small molecules to, and across the surface of polymer matrices is a little-studied problem with important industrial applications. Tackifiers in adhesives, flavors in foods and binding agents in paints all present situations where the function of a product depends on the ability of small molecules to migrate through a polymer matrix to achieve the desired properties such as softness, dispersion of fillers, and to deliver an effect that is felt (or tasted) on a surface. It’s been shown that the chemical and molecular structure, surface free energies, phase behavior, close environment and compatibility of the system, influence the migrants’ motion. When differences in behavior, such as occurrence of segregation to the surface or not, are observed it is then of crucial importance to identify and get a better understanding of the driving forces involved in the process of molecular migration. In this aim, experience is meant to be allied with theory in order to deliver a validated theoretical and computational toolkit to describe and predict these phenomena. The systems that have been chosen for this study aim to address the effect of polarity mismatch between the migrants and the polymer matrix and that of a second migrant over the first one. As a non-polar resin polymer, polyvinyl acetate is used as the material to which more or less polar migrants (sorbitol, carvone, octanoic acid (OA), triacetin) are to be added. Through contact angle measurement a surface excess is seen for sorbitol (polar) mixed with PVAc as the surface energy is lowered compare to the one of pure PVAc. This effect is increased upon the addition of carvon or triacetin (non-polars). Surface micro-structures are also evidenced by atomic force microscopy (AFM). Ion beam analysis (Nuclear Reaction Analysis), supplemented by neutron reflectometry can accurately characterize the self-organization of surfactants, oligomers, aromatic molecules in polymer films in order to relate the macroscopic behavior to the length scales that are amenable to simulation. The nuclear reaction analysis (NRA) data for deuterated OA 20% shows the evidence of a surface excess which is enhanced after annealing. The addition of 10% triacetin, as a second migrant, results in the formation of an underlying layer enriched in triacetin below the surface excess of OA. The results show that molecules in polarity mismatch with the matrix tend to segregate to the surface, and this is favored by the addition of a second migrant of the same polarity than the matrix. As studies have been restricted to materials that are model supported films under static conditions in a first step, it is also wished to address the more challenging conditions of materials under controlled stress or strain. To achieve this, a simple rig and PDMS cell have been designed to stretch the material to a defined strain and to probe these mechanical effects by ion beam analysis and atomic force microscopy. This will make a significant step towards exploring the influence of extensional strain on surface segregation, flavor release in cross-linked rubbers.

Keywords: polymers, surface segregation, thin films, molecular migration

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1506 The Impact of the EU Competition Law on the Asian Systems

Authors: Maria Casoria

Abstract:

Throughout the last decade developing countries have been undergoing substantial reforms to promote the establishment of competition regimes, as consequence of the trade liberalization and the spread of a ‘competition awareness movement’ across the globe. The legislative trend affected the whole Asia. Notwithstanding the existence of extensive joint ventures, cartels and other collusive business relationships in this geographical area, almost all the countries have already passed or are committed to enforce specific laws in the field. The study dwells into legal solutions adopted in the five sub-regions in which the continent is commonly divided –i.e. Central, East, South, Southeast, and Western Asia- and, using a comparative methodology, shed lights on the main differences and similarities in place. The final outcome of the analysis is that, despite the undeniable divergences of approach, what links together the legislation in force in the region is the unveiled influence exercised by the European Union competition regulation. Consequently, in order to properly evaluate the deterrence of the rule of law in the sector concerned, it is fundamental to scrutinize the major role played by the EU and its policy for the evolution of pro-competitive practices in the continent.

Keywords: Asia, competition law, differences and similarities, European union, influences

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1505 Ceramic Ware Waste Potential as Co-Ballast in Dense Masonry Unit Production

Authors: A. A. Ajayi-Banji, M. A. Adegbile, T. D. Akpenpuun, J. Bello, O. Omobowale, D. A. Jenyo

Abstract:

Ceramic ware waste applicability as coarse aggregate was considered in this study for dense masonry unit production. The waste was crushed into 1.4 mm particle size and mixed with natural fine aggregate in the ratio 2:3. Portland ordinary cement, aggregate, and water mix ratio was 1:7:0.5. Masonry units produced were cured for 7, 21 and 28 days prior to compressive test. The result shows that curing age have a significant effect on all the compressive strength indices inspected except for Young’s modulus. Crushing force and the compressive strength of the ceramic-natural fine aggregate blocks increased by 11.7 – 54.7% and 11.6 – 59.2% respectively. The highest ceramic-natural fine block compressive strength at yield and peak, 4.97 MPa, was obtained after 21 days curing age. Ceramic aggregate introduced into the dense blocks improved the suitability of the blocks for construction purposes.

Keywords: ceramic ware waste, co-ballast, dense masonry unit, compressive strength, curing time

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1504 Normally Closed Thermoplastic Microfluidic Valves with Microstructured Valve Seats: A Strategy to Avoid Permanently Bonded Valves during Channel Sealing

Authors: Kebin Li, Keith Morton, Matthew Shiu, Karine Turcotte, Luke Lukic, Teodor Veres

Abstract:

We present a normally closed thermoplastic microfluidic valve design that uses microstructured valve seats to locally prevent the membrane from bonding to the valve seat during microfluidic channel sealing. The microstructured valve seat reduces the adhesion force between the contact surfaces of the valve seat and the membrane locally, allowing valve open and close operations while simultaneously providing a permanent and robust bond elsewhere to cover and seal the microfluidic channel network. Dynamic valve operation including opening and closing times can be tuned by changing the valve seat diameter as well as the density of the microstructures on the valve seats. The influence of the microstructured valve seat on the general flow behavior through the microfluidic devices was also studied. A design window for the fabrication of valve structure is identified and discussed to minimize the fabrication complexity.

Keywords: hot-embossing, injection molding, microfabrication, microfluidics, microvalves, thermoplastic elastomer

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1503 Sprinting Beyond Sexism and Gender Stereotypes: Indian Women Fans' Experiences in the Sports Fandom

Authors: Siddhi Deshpande, Jo Jo Chacko Eapen

Abstract:

Despite almost half of India’s female population engages in watching sports, their experiences in the sports fandom are concealed by ‘traditional masculinity,’ leading to potential exclusion and harassment. To explore these experiences in-depth, this qualitative study aims to understand what coping strategies Indian women fans employ, to sustain their team identification. Employing criterion sampling, participants were screened using The Sports Spectators Identification Scale (SSIS) to assess team identification and a Brief Sexism Questionnaire to confirm participants’ experience with sexism as it aligns with the purpose of the study. The participants were Indian women who had been following any sport for more than eight years, were fluent in English, and were not professionals in Sports. Ten highly identified fans with gendered experiences were recruited for one-on-one semi-structured, in-depth interviews. The data was analyzed using Interpretive Phenomenological Analysis (IPA) to understand the lived-in experiences of women fans experiencing sexism and gender stereotypes, revealing superordinate themes of (1) Ontogenesis and Emotional Investment; (2) Gendered Expectations and Sexism; (3) Coping Strategies and Resilience; (4) Identity, Femininity, Empowerment; (5) Advocacy for Equality and Inclusivity. The findings reflect that Indian women fans experience social exclusion, harassment, sexualization, and commodification, in both online and offline fandoms, where they are disproportionately targeted with threats, misogynistic comments, and attraction-based assumptions, questioning their ‘authenticity’ as fans due to their gender. Women fans interchange between proactive strategies of assertiveness, humor, and knowledge demonstration with defensive strategies of selective engagement, self-regulatory censorship, and desensitization to deal with sexism. In this interplay, the integration of women’s ‘fan identity’ with their self-concept showcases how being a sports fan adds meaning to their lives, despite the constant scrutiny in a male-dominated space, reflecting that femininity and sports should coexist. As a result, they find refuge in female fan communities due to their similar experiences in the fandom and advocate for an equal and inclusive environment where sports are above gender, and not the other way around. A key practical implication of this research is enabling sports organizations to develop inclusive fan engagement policies that actively encourage female fan participation. This includes sensitizing stadium staff and security personnel, promoting gender-neutral language, and, most importantly, establishing safety protocols to protect female fans from adverse experiences in the fandom.

Keywords: coping strategies, female sports fans, femininity, gendered experiences, team identification

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1502 Drivers of Global Great Power Assertiveness: Russia and Its Involvement in the Global South

Authors: Elina Vroblevska, Toms Ratfelders

Abstract:

This paper examines the impact of international status-seeking aspirations on great power behavior within the international system. In particular, we seek to test the assumption advanced by the proponents of the Social Identity Theory (SIT) that the inability to achieve social mobilization through joining perceived higher-status social groups (of states) leads great powers to adopt the approach of social competition in which they aim to equal or outdo the dominant group in the area on which its claim to superior status rests. Since the dissolution of the Soviet Union, Russia has struggled to be accepted as a great power by the group of Western states that had created the dominant international system order, while the Soviet states were isolated. While the 1990s and the beginning of the 21st century can be characterized by striving to integrate into the existing order, the second decade has seen a rather sharp turn towards creating a new power center for Russia through the realization of ideas of multipolarity rivalry and uniqueness of the state itself. Increasingly, we have seen the Kremlin striving to collaborate and mobilize groups of states that fall outside of the categories of democracy, multiculturalism, and international order, the way that is perceived by the dominant group, which can be described as the West. Instead, Russia builds its own narrative where it creates an alternative understanding of these values, differentiating from the higher-status social group. The Global South, from a Russian perspective, is the group of states that can still be swayed to create an alternative power center in the international system - one where Russia can assert its status as a great power. This is based on a number of reasons, the most important being that the global north is already highly institutionalized in terms of economy (the EU) and defense (NATO), leaving no room for Russia but to integrate within the existing framework. Second, the difference in values and their interpretation - Russia has been adamant, for the last twenty years, on basing its moral code on traditional values like religion, the heterosexual family model, and moral superiority, which contradict the overall secularism of the Global North. And last, the striking difference in understanding of state governance models - with Russia becoming more autocratic over the course of the last 20 years, it has deliberately created distance between itself and democratic states, entering a “gray area” of alternative understanding of democracy which is more relatable to the global South countries. Using computational text analysis of the excerpts of Vladimir Putin’s speeches delivered from 2000-2022 regarding the areas that fall outside the immediate area of interest of Russia (the Global South), we identify 80 topics that relate to the particular component of the great power status - interest to use force globally. These topics are compared across four temporal frames that capture the periods of more and less permissible Western social boundaries. We find that there exists a negative association between such permissiveness and Putin’s emphasis on the “use of force” topics. This lends further support to the Social Identity Theory and contributes to broadening its applicability to explaining the questions related to great power assertiveness in areas outside of their primary focus regions.

Keywords: Russia, Global South, great power, identity

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1501 The Incompressible Preference of Turbulence

Authors: Samuel David Dunstan

Abstract:

An elementary observation of a laminar cylindrical Poiseulle-Couette flow profile reveals no distinction in the parabolic streamwise profile from one without a cross-stream flow in whatever reference frame the observation is made. This is because the laminar flow is in solid-body rotation, and there is no intrinsic fluid rotation. Hence the main streamwise Poiseuille flow is unaffected. However, in turbulent (unsteady) cylindrical Poiseuille-Couette flow, the rotational reference frame must be considered, and any observation from an external inertial reference frame can give outright incorrect results. A common misconception in the study of fluid mechanics is the position of the observer does not matter. In this DNS (direct numerical simulation) study, firstly, turbulent flow in a pipe with axial rotation is established. Then in turbulent flow in the concentric pipe, with inner wall rotation, it is shown how the wall streak direction is oriented by the rotational reference frame. The Coriolis force here is not so fictitious after all!

Keywords: concentric pipe, rotational and inertial frames, frame invariance, wall streaks, flow orientation

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1500 The Prediction of Reflection Noise and Its Reduction by Shaped Noise Barriers

Authors: I. L. Kim, J. Y. Lee, A. K. Tekile

Abstract:

In consequence of the very high urbanization rate of Korea, the number of traffic noise damages in areas congested with population and facilities is steadily increasing. The current environmental noise levels data in major cities of the country show that the noise levels exceed the standards set for both day and night times. This research was about comparative analysis in search for optimal soundproof panel shape and design factor that can minimize sound reflection noise. In addition to the normal flat-type panel shape, the reflection noise reduction of swelling-type, combined swelling and curved-type, and screen-type were evaluated. The noise source model Nord 2000, which often provides abundant information compared to models for the similar purpose, was used in the study to determine the overall noise level. Based on vehicle categorization in Korea, the noise levels for varying frequency from different heights of the sound source (directivity heights of Harmonize model) have been calculated for simulation. Each simulation has been made using the ray-tracing method. The noise level has also been calculated using the noise prediction program called SoundPlan 7.2, for comparison. The noise level prediction was made at 15m (R1), 30 m (R2) and at middle of the road, 2m (R3) receiving the point. By designing the noise barriers by shape and running the prediction program by inserting the noise source on the 2nd lane to the noise barrier side, among the 6 lanes considered, the reflection noise slightly decreased or increased in all noise barriers. At R1, especially in the cases of the screen-type noise barriers, there was no reduction effect predicted in all conditions. However, the swelling-type showed a decrease of 0.7~1.2 dB at R1, performing the best reduction effect among the tested noise barriers. Compared to other forms of noise barriers, the swelling-type was thought to be the most suitable for reducing the reflection noise; however, since a slight increase was predicted at R2, further research based on a more sophisticated categorization of related design factors is necessary. Moreover, as swellings are difficult to produce and the size of the modules are smaller than other panels, it is challenging to install swelling-type noise barriers. If these problems are solved, its applicable region will not be limited to other types of noise barriers. Hence, when a swelling-type noise barrier is installed at a downtown region where the amount of traffic is increasing every day, it will both secure visibility through the transparent walls and diminish any noise pollution due to the reflection. Moreover, when decorated with shapes and design, noise barriers will achieve a visual attraction than a flat-type one and thus will alleviate any psychological hardships related to noise, other than the unique physical soundproofing functions of the soundproof panels.

Keywords: reflection noise, shaped noise barriers, sound proof panel, traffic noise

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1499 Scaling Analysis of the Contact Line and Capillary Interaction Induced by a Floating Tilted Cylinder

Authors: ShiQing Gao, XingYi Zhang, YouHe Zhou

Abstract:

When a floating tilted cylinder pierces a fluid interface, the fulfilment of constant-contact-angle condition along the cylinder results in shift, stretch and distortion of the contact line, thus leading to a capillary interaction. We perform an investigation of the scaling dependence of tilt angle, contact angle, and cylinder radius on the contact line profile and the corresponding capillary interaction by numerical simulation and experiment. Characterized by three characteristic parameters respectively, the dependences for each deformation mode are systematically analyzed. Both the experiment and simulation reveals an invariant structure that is independent of contact angle and radius to characterize the stretch of the contact line for every tilted case. Based on this observation, we then propose a general capillary force scaling law to incredibly grasp all the simulated results, by simply approximating the contact line profile as tilted ellipse.

Keywords: gas-liquid/liquid-fluid interface, colloidal particle, contact line shape, capillary interaction, surface evolver (SE)

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1498 Prediction Modeling of Compression Properties of a Knitted Sportswear Fabric Using Response Surface Method

Authors: Jawairia Umar, Tanveer Hussain, Zulfiqar Ali, Muhammad Maqsood

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Different knitted structures and knitted parameters play a vital role in the stretch and recovery management of compression sportswear in addition to the materials use to generate this stretch and recovery behavior of the fabric. The present work was planned to predict the different performance indicators of a compression sportswear fabric with some ground parameters i.e. base yarn stitch length (polyester as base yarn and spandex as plating yarn involve to make a compression fabric) and linear density of the spandex which is a key material of any sportswear fabric. The prediction models were generated by response surface method for performance indicators such as stretch & recovery percentage, compression generated by the garment on body, total elongation on application of high power force and load generated on certain percentage extension in fabric. Certain physical properties of the fabric were also modeled using these two parameters.

Keywords: Compression, sportswear, stretch and recovery, statistical model, kikuhime

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1497 The Appeal of Vocal Islamism in the West: The Case of Hizb ut-Tahrir vis-à-vis Its Competitors

Authors: Elisa Orofino

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Islamism is a very debated topic in the West but almost exclusively explored in its violent forms. Nevertheless, a number of “vocal radical Islamist” groups exist in the West and legally operate because of their non-violent nature. Vocal radicals continually inspire individuals and lead them towards specific goals and priorities, sometimes even towards violence. This paper uses the long-living group Hizb ut-Tahrir (HT) to explore the elements that make the organization appealing to segments of Muslim community in the West. This paper uses three agency variables - reflexive monitoring, the rationalization of action and the motivations for actions – to analyze HT’s appeal vis-à-vis two other Islamist groups, Ikhwan al-Muslimun and Jamaat-e-Islami (JeI), having similar goals and the same high international profile. This paper concludes that HT’s uniqueness is given by its method, detailed vision of the caliphate, consistency over time and the emphasis placed on the caliphate as the leading force of HT’s unchanged motivation for action.

Keywords: agency, caliphate, Islamist groups, radicalization, vocal radicals

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1496 Analysis of Microstructure around Opak River Pleret Area, Bantul Regency, Special Region of Yogyakarta Province, Indonesia, as a Result of Opak Fault Reactivation, Using Stereographic Method

Authors: Gayus Pratama Polunggu, Pamela Felita Adibrata, Hafidh Fathur Riza

Abstract:

Opak Fault is a large fault that extends from the northeast to the southwest of Yogyakarta Special Region. Opak Fault allegedly re-active after the 2006 Yogyakarta earthquake, about eleven years ago. Opak Fault is a big fault, therefore the activation will bring up the microstructure around the Opak River. This microstructure will reveal a different direction of force from the Opak Fault because the trigger for the emergence of the microstructure is the reactivation of the Opak Fault. In other words, this microstructure is a potentially severe weak area during a tectonic disaster. This research was conducted to find out the impact from the reactivation of Opak Fault that triggered the emergence of microstructure around Opak River which is very useful for disaster mitigation information around research area. This research used the approach from literature study in the form of the journal of structural geology and field study. The method used is a laboratory analysis in the form of stereographic analysis.

Keywords: Opak fault, reactivation, microstructure, stereographic

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1495 Comparison of Loosely Coupled and Tightly Coupled INS/GNSS Architecture for Guided Rocket Navigation System

Authors: Rahmat Purwoko, Bambang Riyanto Trilaksono

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This paper gives comparison of INS/GNSS architecture namely Loosely Coupled and Tightly Coupled using Hardware in the Loop Simulation in Guided Missile RKX-200 rocket model. INS/GNSS Tightly Coupled architecture requires pseudo-range, pseudo-range rate, and position and velocity of each satellite in constellation from GPS (Global Positioning System) measurement. The Loosely Coupled architecture use estimated position and velocity from GNSS receiver. INS/GNSS architecture also requires angular rate and specific force measurement from IMU (Inertial Measurement Unit). Loosely Coupled arhitecture designed using 15 states Kalman Filter and Tightly Coupled designed using 17 states Kalman Filter. Integration algorithm calculation using ECEF frame. Navigation System implemented Zedboard All Programmable SoC.

Keywords: kalman filter, loosely coupled, navigation system, tightly coupled

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1494 Expanded Access through Open and Distance Learning in Nigeria

Authors: Okoro Ngozi Priscilla

Abstract:

Education is the bedrock of development in every nation of the world, and it is very useful in ensuring quality of life for every individual and a better world for the people. Education, therefore, is the basic instrument of economic growth and technological advancement in any society. It is in recognition of this fact that the Nigerian government commits immense resources to ensuring that its citizens acquire education and also policies are being made to ensure the accessibility of education, qualitative higher education is highly recognized as a vital driving force for the socio-economic growth and technological development of nations yet the problem of access to University education in the country persists and therefore brought about the introduction of Open and Distance Learning (ODL) which has as its main objective, the attainment of mass literacy and providing opportunities for those who could not gain admission through designated entrance examination agencies as well as those who could not afford to leave their job to attend a full-time educational programme. Open and distance learning seeks to improve skilled manpower and also improve the skills for those already at work.

Keywords: accessibility, open and distant learning programme, fulltime educational programme, distance learning

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1493 The Simultaneous Effect of Horizontal and Vertical Earthquake Components on the Seismic Response of Buckling-Restrained Braced Frame

Authors: Mahdi Shokrollahi

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Over the past years, much research has been conducted on the vulnerability of structures to earthquakes, which only horizontal components of the earthquake were considered in their seismic analysis and vertical earthquake acceleration especially in near-fault area was less considered. The investigation of the mappings shows that vertical earthquake acceleration can be significantly closer to the maximum horizontal earthquake acceleration, and even exceeds it in some cases. This study has compared the behavior of different members of three steel moment frame with a buckling-restrained brace (BRB), one time only by considering the horizontal component and again by considering simultaneously the horizontal and vertical components under the three mappings of the near-fault area and the effect of vertical acceleration on structural responses is investigated. Finally, according to the results, the vertical component of the earthquake has a greater effect on the axial force of the columns and the vertical displacement of the middle of the beams of the different classes and less on the lateral displacement of the classes.

Keywords: vertical earthquake acceleration, near-fault area, steel frame, horizontal and vertical component of earthquake, buckling-restrained brace

Procedia PDF Downloads 179
1492 Fluorination Renders the Wood Surface Hydrophobic without Any Loos of Physical and Mechanical Properties

Authors: Martial Pouzet, Marc Dubois, Karine Charlet, Alexis Béakou

Abstract:

The availability, the ecologic and economic characteristics of wood are advantages which explain the very wide scope of applications of this material, in several domains such as paper industry, furniture, carpentry and building. However, wood is a hygroscopic material highly sensitive to ambient humidity and temperature. The swelling and the shrinking caused by water absorption and desorption cycles lead to crack and deformation in the wood volume, making it incompatible for such applications. In this study, dynamic fluorination using F2 gas was applied to wood samples (douglas and silver fir species) to decrease their hydrophilic character. The covalent grafting of fluorine atoms onto wood surface through a conversion of C-OH group into C-F was validated by Fourier-Transform infrared spectroscopy and 19F solid state Nuclear Magnetic Resonance. It revealed that the wood, which is initially hydrophilic, acquired a hydrophobic character comparable to that of the Teflon, thanks to fluorination. A good durability of this treatment was also determined by aging tests under ambient atmosphere and under UV irradiation. Moreover, this treatment allowed obtaining hydrophobic character without major structural (morphology, density and colour) or mechanical changes. The maintaining of these properties after fluorination, which requires neither toxic solvent nor heating, appears as a remarkable advantage over other more traditional physical and chemical wood treatments.

Keywords: cellulose, spectroscopy, surface treatment, water absorption

Procedia PDF Downloads 202
1491 Basic One-Dimensional Modelica®-Model for Simulation of Gas-Phase Adsorber Dynamics

Authors: Adrian Rettig, Silvan Schneider, Reto Tamburini, Mirko Kleingries, Ulf Christian Muller

Abstract:

Industrial adsorption processes are, mainly due to si-multaneous heat and mass transfer, characterized by a high level of complexity. The conception of such processes often does not take place systematically; instead scale-up/down respectively number-up/down methods based on existing systems are used. This paper shows how Modelica® can be used to develop a transient model enabling a more systematic design of such ad- and desorption components and processes. The core of this model is a lumped-element submodel of a single adsorbent grain, where the thermodynamic equilibria and the kinetics of the ad- and desorption processes are implemented and solved on the basis of mass-, momentum and energy balances. For validation of this submodel, a fixed bed adsorber, whose characteristics are described in detail in the literature, was modeled and simulated. The simulation results are in good agreement with the experimental results from the literature. Therefore, the model development will be continued, and the extended model will be applied to further adsorber types like rotor adsorbers and moving bed adsorbers.

Keywords: adsorption, desorption, linear driving force, dynamic model, Modelica®, integral equation approach

Procedia PDF Downloads 371
1490 Nonlinear Triad Interactions in Magnetohydrodynamic Plasma Turbulence

Authors: Yasser Rammah, Wolf-Christian Mueller

Abstract:

Nonlinear triad interactions in incompressible three-dimensional magnetohydrodynamic (3D-MHD) turbulence are studied by analyzing data from high-resolution direct numerical simulations of decaying isotropic (5123 grid points) and forced anisotropic (10242 x256 grid points) turbulence. An accurate numerical approach toward analyzing nonlinear turbulent energy transfer function and triad interactions is presented. It involves the direct numerical examination of every wavenumber triad that is associated with the nonlinear terms in the differential equations of MHD in the inertial range of turbulence. The technique allows us to compute the spectral energy transfer and energy fluxes, as well as the spectral locality property of energy transfer function. To this end, the geometrical shape of each underlying wavenumber triad that contributes to the statistical transfer density function is examined to infer the locality of the energy transfer. Results show that the total energy transfer is local via nonlocal triad interactions in decaying macroscopically isotropic MHD turbulence. In anisotropic MHD, turbulence subject to a strong mean magnetic field the nonlinear transfer is generally weaker and exhibits a moderate increase of nonlocality in both perpendicular and parallel directions compared to the isotropic case. These results support the recent mathematical findings, which also claim the locality of nonlinear energy transfer in MHD turbulence.

Keywords: magnetohydrodynamic (MHD) turbulence, transfer density function, locality function, direct numerical simulation (DNS)

Procedia PDF Downloads 385
1489 Identification of High Stress Regions in Proximal Femur During Single-Leg Stance and Sideways Fall Using QCT-Based Finite Element Model

Authors: Hossein Kheirollahi, Yunhua Luo

Abstract:

Studying stress and strain trends in the femur and recognizing femur failure mechanism is very important for preventing hip fracture in the elderly. The aim of this study was to identify high stress and strain regions in the femur during normal walking and falling to find the mechanical behavior and failure mechanism of the femur. We developed a finite element model of the femur from the subject’s quantitative computed tomography (QCT) image and used it to identify potentially high stress and strain regions during the single-leg stance and the sideways fall. It was found that fracture may initiate from the superior region of femoral neck and propagate to the inferior region during a high impact force such as sideways fall. The results of this study showed that the femur bone is more sensitive to strain than stress which indicates the effect of strain, in addition to effect of stress, should be considered for failure analysis.

Keywords: finite element analysis, hip fracture, strain, stress

Procedia PDF Downloads 504
1488 Analysis of the Gait Characteristics of Soldier between the Normal and Loaded Gait

Authors: Ji-il Park, Min Kyu Yu, Jong-woo Lee, Sam-hyeon Yoo

Abstract:

The purpose of this research is to analyze the gait strategy between the normal and loaded gait. To this end, five male participants satisfied two conditions: the normal and loaded gait (backpack load 25.2 kg). As expected, results showed that additional loads elicited not a proportional increase in vertical and shear ground reaction force (GRF) parameters but also increase of the impulse, momentum and mechanical work. However, in case of the loaded gait, the time duration of the double support phase was increased unexpectedly. It is because the double support phase which is more stable than the single support phase can reduce instability of the loaded gait. Also, the directions of the pre-collision and after-collision were moved upward and downward compared to the normal gait. As a result, regardless of the additional backpack load, the impulse-momentum diagram during the step-to-step transition was maintained such as the normal gait. It means that human walk efficiently to keep stability and minimize total net works in case of the loaded gait.

Keywords: normal gait, loaded gait, impulse, collision, gait analysis, mechanical work, backpack load

Procedia PDF Downloads 289
1487 Optimization of Cutting Forces in Drilling of Polimer Composites via Taguchi Methodology

Authors: Eser Yarar, Fahri Vatansever, A. Tamer Erturk, Sedat Karabay

Abstract:

In this study, drilling behavior of multi-layer orthotropic polyester composites reinforced with woven polyester fiber and PTFE particle was investigated. Conventional drilling methods have low cost and ease of use. Therefore, it is one of the most preferred machining methods. The increasing range of use of composite materials in many areas has led to the investigation of the machinability performance of these materials. The drilling capability of the synthetic polymer composite material was investigated by measuring the cutting forces using different tool diameters, feed rate and high cutting speed parameters. Cutting forces were measured using a dynamometer in the experiments. In order to evaluate the results of the experiment, the Taguchi experimental design method was used. According to the results, the optimum cutting parameters were obtained for 0.1 mm/rev, 1070 rpm and 2 mm diameter drill bit. Verification tests were performed for the optimum cutting parameters obtained according to the model. Verification experiments showed the success of the established model.

Keywords: cutting force, drilling, polimer composite, Taguchi

Procedia PDF Downloads 162
1486 Shaabi in the City: On Modernizing Sounds and Exclusion in Egyptian Cities

Authors: Mariam Aref Mahmoud

Abstract:

After centuries of historical development, Egypt is no stranger to national identity frustrations. What may or may not be counted as this “national identity” becomes a source of contention. Today, after decades of neoliberal reform, Cairo has become the center of Egypt’s cultural debacle. At its heart, the Egyptian capital serves as Egypt’s extension into global capitalism, its flailing hope to become part of the modernized, cosmopolitan world. Yet, to converge into this image of cosmopolitanism, Cairo must silence the perceived un-modernized sounds, cultures, and spaces that arise from within its alleyways. Currently, the agitation surrounding shaabi music, particularly, that of mahraganat, places these contentions to the center of the modernization debates. This paper will discuss the process through which the conversations between modernization, space, and culture have taken place through a historical analysis of national identity formation under Egypt’s neoliberal regimes. Through this, the paper concludes that music becomes a spatial force through which public space, identity, and globalization must be contested. From these findings researchers can then analyze Cairo through not only its physical landscapes, but also its metaphysical features – such as the soundscape.

Keywords: music, space, globalization, Cairo

Procedia PDF Downloads 111
1485 Preparation and Antioxidant Activity of Heterocyclic Indole Derivatives

Authors: Tunca Gul Altuntas, Aziz Baydar, Cemre Acar, Sezen Yılmaz, Tulay Coban

Abstract:

Free radicals, which are generated in many bioorganic redox processes, play a role in the pathogenesis of several diseases including cancer, arthritis, hemorrhagic shock, inflammatory, cardiovascular, neurodegenerative diseases and age-related degenerative brain diseases. Exposures of normal cell to free radical damages several structures, oxidizes nucleic acids, proteins, lipids, or DNA. Compounds interfere with the action of reactive oxygen species might be useful in prevention and treatment of these pathologies. A series of indole compounds containing piperazine ring were synthesized. Coupling of indole-2-carboxylic acid with monosubstituted piperazines was accomplished with 1,1’-carbonyldiimidazole (CDI) in a good yield. The structures of prepared compounds were verified in good agreement with their 1H NMR (nuclear magnetic resonance), MS (mass spectrophotometry), and IR (infrared spectrophotometry) characteristics. In this work, all synthetized indole derivatives were screened in vitro for their antioxidative potential against vitamin E (α-tocopherol) using different antioxidant assays such as superoxide anion formation, lipid peroxidation levels in rat liver, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) stable radical scavenging activity. The synthesized compounds showed various levels of inhibition compared to vitamin E. This may give promising results for the development of new antioxidant agents.

Keywords: antioxidant, indoles, piperazines, reactive oxygen species

Procedia PDF Downloads 231