Search results for: dominant frequencies

Authors: Mohammad Bukhari, Oumar Barry

Abstract:

In order to reduce the Aeolian vibration of overhead transmission lines, the Stockbridge damper is usually attached. The efficiency of Stockbridge damper depends on its location on the conductor and its resonant frequencies. When the Stockbridge damper is located on a vibration node, it becomes inefficient. Hence, the static damper should be subrogated by a dynamic one. In the present study, a proposed dynamic absorber for transmission lines is studied. Hamilton’s principle is used to derive the governing equations, then the system of ordinary differential equations is solved numerically. Parametric studies are conducted to determine how certain parameters affect the performance of the absorber. The results demonstrate that replacing the static absorber by a dynamic one enhance the absorber performance for wider range of frequencies. The results also indicate that the maximum displacement decreases as the absorber speed and the forcing frequency increase. However, this reduction in maximum displacement is accompanying with increasing in the steady state vibration displacement. It is also indicated that the energy dissipation in moving absorber covers higher range of frequencies.

Keywords: absorber performance, Aeolian vibration, Hamilton’s principle, stockbridge damper

Procedia PDF Downloads 267

Authors: Joseph Shanks, Matthew Taylor, Foong Kiew Ooi, Chee Keong Chen

Abstract:

Introduction: Evidences of relationship between bone, muscle and standard of competition among young British population is limited in literature. The current literature recognises the independent and synergistic effects of fat free and fat mass as the stimulus for osteogenesis. This study assessed the extent to which physical activity (PA) and standard of competition (CS) influences quantitative ultrasound (QUS) measurements of bone on a cross-sectional basis accounting for muscular strength and anthropometrics in British young males. Methods: Pre-screening grouped 66 males aged 18-25 years into controls (n=33) and district level athletes (DLAs) (n=33) as well as low (n=21), moderate (n=23) and high (n=22) physical activity categories (PACs). All participants underwent QUS measurements of bone (4 sites, i.e. dominant distal radius (DR), dominant mid-shaft tibia (DT), non-dominant distal radius (NR) and non-dominant mid-shaft tibia (NT)), isokinetic strength tests (dominant and non-dominant knee flexion and extension) and anthropometric measurements. Results: There were no significant differences between any of the groups with respect to QUS measurements of bone at all sites with regards to PACs or CS. Significant higher isokinetic strength values were observed in DLAs than controls (p < 0.05), and higher than low PACs (p < 0.05) at 60o.s-1 of concentric and eccentric measurements. No differences in subcutaneous fat thickness were found between all the groups (CS or PACs). Percentages of body fat were significantly higher (p < .05) in low than high PACs and CS groups. There were significant positive relationships between non dominant radial speed of sound and fat free mass at both DR (r=0.383, p=0.001) and NR (r=0.319, p=0.009) sites in all participants. Conclusion: The present study findings indicated that muscular strength and body fat are closely related to physical activity level and standard of competition. However, bone health status reflected by quantitative ultrasound (QUS) measurements of bone is not related to physical activity level and standard of competition in British young males.

Keywords: bone, muscular strength, physical activity, standard of competition

Procedia PDF Downloads 514

Authors: Emine Şahin, Murat Soner Balcıoğlu

Abstract:

The aim of this study was to determine the growth hormone (bGH) gene polymorphism in the Holstein cattle growing around Antalya in Turkey. In order to determine the bGH-AluI polymorphism, polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) method was performed. A 891 bp fragment of bGH was amplified and two types of alleles C and D for bGH were observed. In this study, the frequencies of C and D alleles were 0.8438 and 0.1562, respectively. The genotype frequencies for CC, CD and DD were 0.787, 0.191 and 0.022, respectively. According to the results of the chi-square test, a significant deviation from the Hardy-Weinberg equilibrium was not determined for the bGH locus in the population.

Keywords: Growth Hormone Gene, Holstein , Polymorphism, RFLP

Procedia PDF Downloads 371

Authors: Jamal Takhchi

Abstract:

The understanding of vibration propagation in complex structures such as automotive body in white remains a challenging issue in car design regarding NVH performances. The current analysis is limited to the low frequency range where modal concepts are dominant. Higher frequencies, between 200 and 1000 Hz, will become critical With the rise of electrification. EVs annoying sounds are mostly whines created by either Gears or e-motors between 300 Hz and 2 kHz. Structural intensity analysis was Experienced a few years ago on finite element models. The application was promising but limited by the fact that the propagating 3D intensity vector field is masked by a rotational Intensity field. This rotational field should be filtered using a differential operator. The expression of this operator in the framework of finite element modeling is not yet known. The aim of the proposed work is to implement this operator in the current dynamic solver (NASTRAN) of Stellantis and develop the Expected methodology for the mid-frequency structural analysis of electrified vehicles.

Keywords: structural intensity, NVH, body in white, irrotatational intensity

Procedia PDF Downloads 155

Authors: Seyedmohammad Mousavian

Abstract:

Technological advancements are becoming unprecedentedly dominant everywhere. This dominance requires drastic chTechnological advancements are becoming unprecedentedly dominant everywhere. This dominance requires drastic changes in traditional thinking, procedures, and responsibilities. Chief Financial Officers (CFOs) have long played a key role in every organization around the globe and must adapt themselves to the disruptive technology which brings positive and negative points. This paper will discuss the shift of the traditional role of CFOs from just reporting toward more innovative roles like “Storytelling”, business partnering, and strategic planning.

Keywords: accounting information system, technology, data, CFO, finance

Procedia PDF Downloads 140

Authors: M. S. Ahmed, F. A. Mohammad

Abstract:

This paper focuses on the dynamic behavior of reinforced concrete (RC) slabs. Therefore, the theoretical modal analysis was performed using two different types of boundary conditions. Modal analysis method is the most important dynamic analyses. The analysis would be modal case when there is no external force on the structure. By using this method in this paper, the effects of freely and simply supported boundary conditions on the frequencies and mode shapes of RC square slabs are studied. ANSYS software was employed to derive the finite element model to determine the natural frequencies and mode shapes of the slabs. Then, the obtained results through numerical analysis (finite element analysis) would be compared with an exact solution. The main goal of the research study is to predict how the boundary conditions change the behavior of the slab structures prior to performing experimental modal analysis. Based on the results, it is concluded that simply support boundary condition has obvious influence to increase the natural frequencies and change the shape of mode when it is compared with freely supported boundary condition of slabs. This means that such support conditions have direct influence on the dynamic behavior of the slabs. Thus, it is suggested to use free-free boundary condition in experimental modal analysis to precisely reflect the properties of the structure. By using free-free boundary conditions, the influence of poorly defined supports is interrupted.

Keywords: natural frequencies, mode shapes, modal analysis, ANSYS software, RC slabs

Procedia PDF Downloads 457

Authors: S. Lecheb, A. Chellil, H. Mechakra, S. Attou, H. Kebir

Abstract:

Although leaf springs are one of the oldest suspension components they are still frequently used, especially in commercial vehicles. Being able to capture the leaf spring characteristics is of significant importance for vehicle handling dynamics studies. The main function of leaf spring is not only to support vertical load but also to isolate road induced vibrations. It is subjected to millions of load cycles leading to fatigue failure. It needs to have excellent fatigue life. The objective of this work is its use of Abaqus software to locate the most stressed areas and predict the areas in which it occurs in fatigue and crack of leaf spring and calculate the stress and frequencies of this model.

Keywords: leaf spring, crack, stress, natural frequencies

Procedia PDF Downloads 463

Authors: Mohammed Husein Mohammad Rashid

Abstract:

For a bounded linear operator T acting on a complex infinite dimensional Hilbert space ℋ, we say that T is ∗-class A operator (abbreviation T∈A*) if |T²|≥ |T*|². In this article, we prove the following assertions:(i) we establish some conditions which imply the normality of ∗-class A; (ii) we consider ∗-class A operator T ∈ ℬ(ℋ) with reducing kernel such that TX = XS for some X ∈ ℬ(K, ℋ) and prove the Fuglede-Putnam type theorem when adjoint of S ∈ ℬ(K) is dominant operators; (iii) furthermore, we extend the asymmetric Putnam-Fuglede theorem the class of ∗-class A operators.

Keywords: fuglede-putnam theorem, normal operators, ∗-class a operators, dominant operators

Procedia PDF Downloads 88

Authors: Hosein Shokoohmand, Mohamad Esmaeil Jomeh

Abstract:

The present thesis studies the effect of different factors such as frequency of oscillatory flow, change in constant wall heat flux and two-phase current state, on heat transfer in a pipe in presence of porous medium. In this experimental study is conducted for Reynolds numbers in a range of Re=850 to Re=10000 and oscillatory frequencies of 5, 20, 10, 30 and 40 Hz with constant heat flux of 585 w/m2 and 819 w/m2. The results indicate that increase in oscillation frequency in higher frequencies for heat flux of 585 w/m2 leads to an increase in heat transfer; however, in the rest of tests it results in a heat transfer decrease. Increasing Reynolds number in a pulsation mist flow causes an increase in average Nusselt number values. The effect of oscillation frequencies in a pulsation mist flow for different Reynolds numbers has revealed different results, in a way that for some Reynolds numbers an increase of frequency has led to a heat transfer decrease.

Keywords: Reynolds numbers, frequency of oscillatory flow, constant heat flux, mist flow

Procedia PDF Downloads 494

Authors: Jian Peng, Wenhui Xiong, Zheng Lu

Abstract:

An optimal recipe of amendment (nutrients and electron acceptors) was developed and dominant indigenous benzene-degrading microorganisms were characterized in this study. Lessons were learnt from the development of the optimal amendment recipe: (1) salinity and substantial initial concentration of benzene were detrimental for benzene biodegradation; (2) large dose of amendments can shorten the lag time for benzene biodegradation occurrence; (3) toluene was an essential co-substance for promoting benzene degradation activity. The stable isotope probing study identified incorporation 13C from 13C-benzene into microorganisms, which can be considered as a direct evidence of the occurrence of benzene biodegradation. The dominant mechanism for benzene removal was identified by quantitative polymerase chain reaction analysis to be nitrate reduction. Microbial analyses (denaturing gradient gel electrophoresis and 16S ribosomal RNA) demonstrated that members of genus Dokdonella spp., Pusillimonas spp., and Advenella spp. were predominant within the microbial community and involved in the anaerobic benzene bioremediation.

Keywords: benzene, enhanced anaerobic bioremediation, stable isotope probing, biosep biotrap

Procedia PDF Downloads 341

Authors: Seyyed Feisal Asbaghian Namin, Reza Pilafkan, Mahmood Kaffash Irzarahimi

Abstract:

TThis paper considers vibration of single-layered graphene sheets using molecular dynamics (MD) and nonlocal elasticity theory. Based on the MD simulations, Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS), an open source software, is used to obtain fundamental frequencies. On the other hand, governing equations are derived using nonlocal elasticity and first order shear deformation theory (FSDT) and solved using generalized differential quadrature method (GDQ). The small-scale effect is applied in governing equations of motion by nonlocal parameter. The effect of different side lengths, boundary conditions and nonlocal parameter are inspected for aforementioned methods. Results are obtained from MD simulations is compared with those of the nonlocal elasticity theory to calculate appropriate values for the nonlocal parameter. The nonlocal parameter value is suggested for graphene sheets with various boundary conditions. Furthermore, it is shown that the nonlocal elasticity approach using classical plate theory (CLPT) assumptions overestimates the natural frequencies.

Keywords: graphene sheets, molecular dynamics simulations, fundamental frequencies, nonlocal elasticity theory, nonlocal parameter

Procedia PDF Downloads 521

Authors: Yu-Hsi Huang, Ying-Der Tsai

Abstract:

Piezoelectric circular plates can provide out-of-plane vibrational displacements on low frequency and in-plane vibrational displacements on high frequency. Piezoelectric semi-spherical shell, which is double-curvature structure, can induce three-dimensional vibrational displacements over a large frequency range. In this study, three-dimensional vibrational characteristics of piezoelectric semi-spherical shells with free boundary conditions are investigated using three experimental methods and finite element numerical modeling. For the experimental measurements, amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI) is used to obtain resonant frequencies and radial and azimuthal mode shapes. This optical technique utilizes a full-field and non-contact optical system that measures both the natural frequency and corresponding vibration mode shape simultaneously in real time. The second experimental technique used, laser displacement meter is a point-wise displacement measurement method that determines the resonant frequencies of the piezoelectric shell. An impedance analyzer is used to determine the in-plane resonant frequencies of the piezoelectric semi-spherical shell. The experimental results of the resonant frequencies and mode shapes for the piezoelectric shell are verified with the result from finite element analysis. Excellent agreement between the experimental measurements and numerical calculation is presented on the three-dimensional vibrational characteristics of the piezoelectric semi-spherical shell.

Keywords: piezoelectric semi-spherical shell, mode shape, resonant frequency, electronic speckle pattern interferometry, radial vibration, azimuthal vibration

Procedia PDF Downloads 234

Authors: Samy Madbouly

Abstract:

The relaxation behavior of biorenewable castor oil-based polyurethane-lignin thin films synthesized in homogenous waterborne dispersions was investigated as a function of concentration at different temperatures and frequencies using broadband dielectric relaxation spectroscopy (BDRS). The molecular dynamics of the glass relaxation process and the local relaxation process of the PU-LS thin films were studied over a wide range of temperatures (-70 to 30 ℃) and frequencies (5 × 10−2 to 0.5 × 107 Hz) for different lignin concentration. Four relaxation processes have been observed namely; ?-, β-, γ-relaxations and ionic conductivity for pure castor oil-based PU and castor oil-lignin-based PU thin films at different temperatures and frequencies ranges. The Vogel-Fulcher-Tammann equation was found to be well described the temperature dependence of the characteristic relaxation times of the ?-relaxation process. However, on the other hand, the molecular dynamics of both β- and γ-relaxation processes were given by the Arrhenius equation. The incorporation of lignin into the castor oil-based PU significantly increased the glass transition temperature and primitivity of the thin films. In addition, the broadness, intensity, and molecular dynamics of the only observed ?-relaxation process were found to be strongly dependent on lignin concentration.

Keywords: castor oil, lignin, polyurethane, dielectric, dispersions

Procedia PDF Downloads 204

Authors: Ellen Holtmaat

Abstract:

With an ever increasing influence of international organizations (IOs) on national policies and with the expectation that IOs are the transmission belts of world ideologies it is interesting to see to what extent IOs express a specific ideology and what determines the dominance of this ideology. This thesis looks at the OECD as IO and higher education as a field of policy. Evidence is found that the OECD promotes neoliberal developments in higher education and that its position is influenced by business, dominant countries and the dominant beliefs that are carried by the people working for the OECD that form an epistemic community. These results can possibly be extrapolated to other IOs.

Keywords: higher education, international organizations, neoliberal, OECD

Procedia PDF Downloads 372

Authors: Yu Hua Yan

Abstract:

Background: This research attempts to extend and apply the concept of service dominant logic on My Health Bank platform, analyzed to find out are there any significant difference in wills to participate (potential factors for value) on the results of value co-creation? Methods: The questionnaires were delivered from August 2017 to October 2017 in hospitals. 167 valid ones were received, with an effective response rate of 98.2%. Results: This research employed the questionnaire method in collecting research data, with patients that have used My Health Bank as objects, to whom questionnaires were sent. Regarding the factors influencing therapeutic effects, in the statistics of capability and interaction, it reached a significant level (p <0.1). Regarding the factors influencing satisfaction on medical service, in the statistics of capability and interaction, it reached a significant level (p <0.001). Conclusion: Regarding the contributions of this research, it is possible to clarify its contents with the studies on value co-creation to enrich the literature of the studies of service dominant logic and value co-creation in Taiwan. Regarding its contribution in practice, the results of this research allows the value advocator – the government, to have a broader view in the consideration of making the policies on value co-creation.

Keywords: My Health Bank, interactive, participation, value creation

Procedia PDF Downloads 164

Authors: Arash Jafari, Somaye Bahrami, Mohammad Hossein Razi Jalali

Abstract:

The aim of this study was the isolation and identification of excretory-secretory and somatic antigens from D. dendriticum by SDS-PAGE and evaluation of humeral immune response against these antigens. The sera of infected sheep with different infection degrees were collected. Somatic and ES proteins were isolated with SDS PAGE. Immunogenicity properties of the resulting proteins were determined using western blot analysis. The total extract of somatic antigens analysed by SDS-PAGE revealed 21 proteins. In mild infection, bands of 130 KDa were immune dominant. In moderate infections 48, 80 and 130 KDa and in heavy infections 48, 60, 80, 130 KDa were detected as immune dominant bands. In ES antigens, mild infection 130 KDa, in moderate infection 100, 120 and 130 KDa and in heavy infection 45, 80, 85, 100, 120 and 130 KDa were immune dominant bands. The most immunogenic protein band during different degrees of infection was 130KDa.

Keywords: Dicrocoelium dendriticum excretory-secretory antigens, somatic antigens, western blot

Procedia PDF Downloads 602

Authors: Yea-Pyng Lin

Abstract:

Dignity is a core element of nursing care. Maintaining the dignity of patients is an important issue because the health and recovery of patients can be adversely affected by a lack of dignity in their care. The aim of this study was to explore the effects of a nursing dignity care program upon patients’ dignity in care. A quasi-experimental research design was implemented. Nurses were recruited by purposive sampling, and their patients were recruited by simple random sampling. Nurses in the experimental group received the nursing educational program on dignity care, while nurses in the control group received in-service education as usual. Data were collected via two instruments: the dignity in care scale for nurses and the dignity in care scale to patients, both of which were developed by the researcher. Both questionnaires consisted of three domains: agreement, importance, and frequencies of providing dignity care. A total of 178 nurses in the experimental group and 193 nurses in the control group completed the pretest and the follow-up evaluations at the first month, the third month, and the sixth month. The number of patients who were cared for by the nurses in the experimental group was 94 in the pretest. The number of patients in the post-test at the first, third, and sixth months were 91, 85, and 77, respectively. In the control group, 88 patients completed the II pretest, and 80 filled out the post-test at the first month, 77 at the third, and 74 at the sixth month. The major findings revealed the scores of agreement domain among nurses in the experimental group were found significantly different from those who in the control group at each point of time. The scores of importance domain between these two groups also displayed significant differences at pretest and the first month of post-test. Moreover, the frequencies of proving dignity care to patients were significant at pretest, the third month and sixth month of post-test. However, the experimental group had only significantly different from those who in the control group on the frequencies of receiving dignity care especially in the items of ‘privacy care,’ ‘communication care,’ and ‘emotional care’ for the patients. The results show that the nursing program on dignity care could increase nurses’ dignity care for patients in three domains of agreement, importance, and frequencies of providing dignity care. For patients, only the frequencies of receiving dignity care were significantly increased. Therefore, the nursing program on dignity care could be applicable for nurses’ in-service education and practice to enhance the ability of nurses to care for patient’s dignity.

Keywords: nurses, patients, dignity care, quasi-experimental, nursing education

Procedia PDF Downloads 466

Authors: Armin Amindari

Abstract:

Hermetic compressors are used widely for refrigeration, heat pump, and air conditioning applications. With the improvement of energy conservation and environmental protection requirements, inverter compressors that operates at different speeds have become increasingly attractive in the industry. Although speed change capability is more efficient, passing through resonant frequencies may lead to excessive vibrations. In this work, an integrated vibration control approach based on flexible multi-body dynamics theory is used for optimizing the vibration amplitudes of the compressor at different operating speeds. To examine the compressor vibrations, all the forces and moments exerted on the cylinder block were clarified and minimized using balancers attached to the upper and lower ends of the motor rotor and crankshaft. The vibration response of the system was simulated using Motionview™ software. In addition, mass-spring optimization was adopted to shift the resonant frequencies out of the operating speeds. The modal shapes of the system were studied using Optistruct™ solver. Using this approach, the vibrations were reduced up to 56% through dynamic simulations. The results were in high agreement with various experimental test data. In addition, the vibration resonance problem observed at low speeds was solved by shifting the resonant frequencies through optimization studies.

Keywords: vibration, MBD, compressor, hermetic

Procedia PDF Downloads 100

Authors: Gabriela Rivadeneyra-Romero, Claudia del C. Gutierrez Torres, Sergio A. Martinez-Delgadillo, Victor X. Mendoza-Escamilla, Alejandro Alonzo-Garcia

Abstract:

Ultrasonic degradation is currently being used in sonochemical reactors to degrade pollutant compounds from aqueous media, as emerging contaminants (e.g. pharmaceuticals, drugs and personal care products.) because they can produce possible ecological impacts on the environment. For this reason, it is important to develop appropriate water and wastewater treatments able to reduce pollution and increase reuse. Pollutants such as textile dyes, aromatic and phenolic compounds, cholorobenzene, bisphenol-A and carboxylic acid and other organic pollutants, can be removed from wastewaters by sonochemical oxidation. The effect on the removal of pollutants depends on the type of the ultrasonic frequency used; however, not much studies have been done related to the behavior of the fluid into the sonoreactors operated at different ultrasonic frequencies. Based on the above, it is necessary to study the hydrodynamic behavior of the liquid generated by the ultrasonic irradiation to design efficient sonoreactors to reduce treatment times and costs. In this work, it was studied the hydrodynamic behavior of the fluid in sonochemical reactors at different frequencies (250 kHz, 500 kHz and 1000 kHz). The performances of the sonoreactors at those frequencies were simulated using computational fluid dynamics (CFD). Due to there is great sound speed gradient between piezoelectric and fluid, k-e models were used. Piezoelectric was defined as a vibration surface, to evaluate the different frequencies effect on the fluid into sonochemical reactor. Structured hexahedral cells were used to mesh the computational liquid domain, and fine triangular cells were used to mesh the piezoelectric transducers. Unsteady state conditions were used in the solver. Estimation of the dissipation rate, flow field velocities, Reynolds stress and turbulent quantities were evaluated by CFD and 2D-PIV measurements. Test results show that there is no necessary correlation between an increase of the ultrasonic frequency and the pollutant degradation, moreover, the reactor geometry and power density are important factors that should be considered in the sonochemical reactor design.

Keywords: CFD, reactor, ultrasound, wastewater

Procedia PDF Downloads 190

Authors: Yanga Lusanda Praiseworth Majola

Abstract:

The small town of Umzimkhulu is situated in the KwaZulu-Natal province of South Africa and was once the Bantustan of Transkei. Citizens of Umzimkulu are called amaBhaca because they speak isiBhaca, which is a non-standard language but is mutually intelligible to three standard official languages, isiXhosa, isiZulu, and siSwati. Since Umzimkhulu was under the Eastern Cape Province prior to 2006, isiXhosa is used for official purposes, particularly in schools, then isiZulu is used in other sectors; this is despite the fact that the majority of Umzimkhulu citizens regard themselves as amaBhaca. This poses a threat to both isiBhaca as a language and the identity of amaBhaca because Umzimkhulu is situated in KZN, where isiZulu is the dominant language spoken by the majority in the province. The primary objective of this study is to unveil, using the language dominance theory, how dominant languages pose a threat to minority and developing languages or dialects. The study employed a mixed-methods approach. Data was obtained from key community members and leaders who were identified as amaBhaca, who have lived in Umzimkhulu their whole lives. The main findings of the study are that although isiBhaca is classified as a dialect of isiXhosa, linguistically, it is closer to isiZulu, and thus isiZulu poses much threat to the existence of isiBhaca since it becomes easy for amaBhaca to switch from isiBhaca to isiZulu and end up not having an interest in isiBhaca. Respondents revealed that in their view, isiBhaca is a language of its own, and the continuous use and empowerment of isiZulu in Umzimkhulu, particularly in the professional settings, is detrimental to isiBhaca, and this subsequently has the potential of endangering the existence of isiBhaca and might lead to its attrition.

Keywords: language dominance, dominant languages, minority languages, language attrition

Procedia PDF Downloads 87

Authors: Sanjeeva Reddy, D. Vakula

Abstract:

A single layer, multi-band triangular patch antenna is proposed for WLAN/WiMAX applications with different polarization requirements. This probe feed patch is integrated with arc shaped slit to achieve circular polarized (CP) and linearly polarized (LP) radiation characteristics. The main contribution of antenna is to resonate the frequencies of 2.4 GHz with CP and 3.5 GHz, 5.28 GHz with LP. The design procedure of antenna is described and the performance is validated using measurements. Size of antenna is also reduced and provides stable gain at all resonant frequencies. Proposed structure also provides better enhancement in terms of 10-dB impedance bandwidth, achieved gain of 5.1, 5.6, and 2.9 dBi at respective bands.

Keywords: circular polarization, arc shaped slit, multi band antenna, triangular patch antenna, axial ratio

Procedia PDF Downloads 397

Authors: Vasileios Gerakis, Fontounasios Christos, Alkis Hatzopoulos

Abstract:

A study of the impact of metal guard rings on the coupling between two square metal pads is presented. The structure is designed over a bulk silicon substrate with epitaxial layer, so the coupling through the substrate is also involved. A lightly doped profile is adopted and is simulated by means of an electromagnetic simulator for various pad distances and different metal layers, assuming a 65 nm bulk CMOS technology. The impact of various guard ring design (geometrical) parameters is examined. Furthermore, the increase of isolation (resulting in reduction of the noise coupling) between the pads by cutting the ring, or by using multiple rings, is also analyzed. S parameters are used to compare the various structures.

Keywords: guard rings, metal pad coupling, millimeter wave frequencies, substrate noise,

Procedia PDF Downloads 539

Authors: Meng Koon Lee, Mohammad Hosseini Fouladi, Satesh Narayana Namasivayam

Abstract:

Research is focused on the response of soundboards of Classical guitars at frequencies up to 5 kHz as the soundboard is a major contributor to acoustic radiation at high frequencies when compared to the bridge and sound hole. A thin rectangular plate of variable thickness that is simply-supported on all sides is used as an analytical model of the research. This model is used to study the response of the guitar soundboard as the latter can be considered as a modified form of a rectangular plate. Homotopy Perturbation Method (HPM) is selected as a mathematical method to obtain an analytical solution of the 4th-order parabolic partial differential equation of motion of the rectangular plate of constant thickness viewed as a linear problem. This procedure is generalized to the nonlinear problem of the rectangular plate with variable thickness and an analytical solution can also be obtained. Sound power is used as a parameter to investigate the acoustic radiation of soundboards made from spruce using various bracing patterns. The sound power of soundboards made from Malaysian softwood such as damar minyak, sempilor or podo are investigated to determine the viability of replacing spruce as future materials for soundboards of Classical guitars.

Keywords: rectangular plates, analytical solution, homotopy perturbation, natural frequencies

Procedia PDF Downloads 389

Authors: Chrysanthi S. Tiliakou, Katerina T. Frantzi

Abstract:

Writing has always been considered a most demanding skill for English as a Foreign Language learners as well as for native speakers. Novice foreign language writers are asked to handle a limited range of vocabulary to produce writing tasks at lower levels. Adverbs are the parts of speech that are not used extensively in the early stages of English as a Foreign Language writing. An additional problem with learning new adverbs is that, next to learning their meanings, learners are expected to acquire the proper placement of adverbs in a sentence. The use of adverbs is important as they enhance “expressive richness to one’s message”. By exploring the patterns of use of adverbs, researchers and educators can identify types of adverbs, which appear more taxing for young learners or that puzzle novice English as a Foreign Language writers with their placement, and focus on their teaching. To this end, the study examines the use of adverbs on two written Corpora of young learners of English of A1 – A2 levels and determines the types of adverbs used, their frequencies, problems in their use, and whether there is any differentiation between levels. The Antconc concordancing tool was used for the Greek Learner Corpus, and the Corpuscle concordancing tool for the Norwegian Corpus. The research found a similarity in the normalized frequencies of the adverbs used in the A1-A2 level Greek Learner Corpus with the frequencies of the same adverbs in the Norwegian Learner Corpus.

Keywords: learner corpora, young learners, writing, use of adverbs

Procedia PDF Downloads 92

Authors: Radhika Jagtap

Abstract:

Contemporary scholarship in international legal theory is investigating new avenues of providing alternatives to dominant concepts. Indigenous peoples’ philosophies and perspectives developed through them provide a fertile ground to explore similar alternative ideas. This review paper evaluates the theorized accounts of indigenous scholarships which have contributed towards a rich body of knowledge generating alternative visions on dominant notions of ‘post coloniality’, ‘resistance’ and ‘globalization’. Further, it shall assess the relevance of such a project in shaping contemporary international legal thought. Traditional or classical international law has been opined to be highly influenced by the colonial and imperialist history which also left a mark on the way dominant discourses of resistance and globalization are read in mainstream international law. The paper shall first define what do we mean by indigenous philosophy and what kind of indigeneity is that inclusive of. Second, the paper defines the dominant discourse and then counters the same with the alternative indigenous perspective in the case of each concept that is in question. Finally, the paper shall conclude with certain theoretical findings – that the post coloniality, from indigenous perspective, lead to the further marginalization of indigeneity, especially in the third world; that human rights as the sole means of representing resistance in international law ends up making it a very state-centric discipline and last, that globalization from an indigenous, marginalised perspective is not as celebrated as it is in mainstream international law. Major scholarly works that shall be central to the discussion are those of Linda Tuiwahi Smith, Ella Shohat and David Harvey. The nature of the research shall be inductive and involve mostly theoretical review of scholarly works.

Keywords: indigenous, post colonial, globalization, perspectives

Procedia PDF Downloads 337

Authors: Yvonne Christelle M. de Guzman, Charity Faye T. Cabie

Abstract:

This study analyzed the contents of ten issues of Cosmopolitan Magazine from 2011 to 2015. The researcher found out the hegemony among Filipino women as dictated by Cosmopolitan magazine through the use of Semiotic Analysis, Laura Mulvey’s Male Gaze and Gramsci’s concept of hegemony. The researcher also looked at the themes of cover stories, words used to describe women, meanings behind the color of magazine’s front cover, clothing, physique and pose such as gesture and facial expression used by the cover girl. However, the entire content of the magazine was not taken into account.

Keywords: dominant ideology, male gaze, semiotics, women

Procedia PDF Downloads 390

Authors: Ivanova B. Natalia, Djambova Т. Svetlana, Hristev S. Ivailo

Abstract:

The acoustic properties of recycled felt panels have been investigated using various methods. Experimentally, the sound insulation of the panels has been evaluated for frequencies in the range of 600 Hz to 4000 Hz, utilizing a small-sized acoustic chamber. Additionally, the sound absorption coefficient for the frequency range of 63 Hz to 4000 Hz was measured according to the EN ISO 354 standard in a laboratory reverberation room. This research was deemed necessary after conducting reverberation time measurements of a university classroom following the EN ISO 3382-2 standard. The measurements indicated values of 2.86 s at 500 Hz, 3.23 s at 1000 Hz, and 2.53 s at 2000 Hz, which significantly exceeded the requirements set by the national regulatory framework (0.6s) for such premises. For this reason, recycled felt panels have been investigated in the laboratory, showing very good acoustic properties at high frequencies. To enhance performance in the low frequencies, the influence of the distance of the panel spacing was examined. Furthermore, the sound insulation of the panels was studied to expand the possibilities of their application, both for the acoustic treatment of educational and multifunctional halls and for sound insulation purposes (e.g., a suspended ceiling with an air gap passing from room to room). As a conclusion, a theoretical acoustic design of the classroom has been carried out with suggestions for improvements to achieve the necessary acoustic and aesthetic parameters for such rooms.

Keywords: acoustic panels, recycled felt, sound absorption, sound insulation, classroom acoustics

Procedia PDF Downloads 90

Authors: Bita Mashayekhi, Farzaneh Jalali, Alemeh Yazdanian

Abstract:

This study contributes to identifying the corporate governance indices in previous researches by using content analysis on relevant papers published in 20 top accounting journals according to Google Scholar ranking, dated from 1990 to 2016. For this purpose, 65 papers are scrutinized deeply, and the concepts of corporate governance are coded and categorized. Then extracted indices are clustered into 10 and 51 categories and subcategories, respectively; and their frequencies are determined. Results show that the board of directors’ characteristics is employed more frequently in reviewed papers, and the board of directors’ independency is the most frequent index within the 97 percent of our sample. Duality, board size, and ownership structure have more frequencies in comparison with other extracted corporate governance indices.

Keywords: corporate governance, content analysis, corporate governance index, top accounting journals

Procedia PDF Downloads 354

Authors: Norezzine Abdelaziz, Rebouh Nazih Yacer, Kezimana Parfait, Parpura D. I., Gadzhikurbanov A., Anastasios Dranidis

Abstract:

The genetic variation of Shvicezebuvides cattle from three different farms in the Tajikistan Republic was studied using 10 microsatellite markers (SSR). The trials were laid out using a multi- locus analysis system for the analysis of cattle microsatellite locus. An estimated genetic variability of the examined livestock is given in the article. The results of our SSR analysis as well as the numbers and frequencies of common alleles in studied samples, we established a high genetic similarity of studied samples. These results can also be furthermore useful in the decision making for preservation and rational genetic resources usage of the Tajik Shvicezebuvides cattle.

Keywords: genetic characteristic, frequencies of the occurrence alleles, microsatellite markers, Swiss cattle

Procedia PDF Downloads 302

Authors: A. A. Vasin, N. V. Klassen, A. M. Likhter

Abstract:

Water suspensions of in-organic (metals and oxides) and organic nano-objects (chitozan and collagen) were subjected to the treatment of direct and alternative electrical fields. In addition to quasi-periodical spatial patterning resonance-like performance of spatial distributions of these suspensions has been found at low frequencies of alternating electrical field. These resonances are explained as the result of creation of equilibrium states of groups of charged nano-objects with opposite signs of charges at the interparticle distances where the forces of Coulomb attraction are compensated by the repulsion forces induced by relatively negative polarization of hydrated regions surrounding the nanoparticles with respect to pure water. The low frequencies of these resonances are explained by comparatively big distances between the particles and their big masses with t\respect to masses of atoms constituting molecules with high resonance frequencies. These new resonances open a new approach to detailed modeling and understanding of mechanisms of the influence of electrical fields on the functioning of internal organs of living organisms at the level of cells and neurons.

Keywords: bio-polymers, chitosan, collagen, nanoparticles, coulomb attraction, polarization repulsion, periodical patterning, electrical low frequency resonances, transformations

Procedia PDF Downloads 546