Search results for: scattering length

Authors: Hubert Klar

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High double excitation of two-electron atoms has been investigated using hyperpherical coordinates within a modified adiabatic expansion technique. This modification creates a novel fictitious force leading to a spontaneous exchange symmetry breaking at high double excitation. The Pauli principle must therefore be regarded as approximation valid only at low excitation energy. Threshold electron scattering from high Rydberg states shows an unexpected time reversal symmetry breaking. At threshold for double escape we discover a broad (few eV) Cooper pair.

Keywords: correlation, resonances, threshold ionization, Cooper pair

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Authors: Muhammad Hassan Khalil, Xu Jiadong

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Detection of malignant tumor inside the breast of women is a challenging field for the researchers. MWI (Microwave imaging) for breast cancer diagnosis has been of interest for last two decades, newly it suggested for finding cancerous tissues of women breast. A simple and basic idea of the mathematical modeling is used throughout this paper for imaging of malignant tumor. In this paper, the authors explained inverse scattering method in the microwave imaging and also present some simulation results.

Keywords: breast cancer detection, microwave imaging, tomography, tumor

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Authors: Xiaobai Li, Li Li, Yujin Hu, Weiming Deng, Zhe Ding

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A size-dependent Euler–Bernoulli beam model, which accounts for nonlocal stress field, strain gradient field and higher order inertia force field, is derived based on the nonlocal strain gradient theory considering velocity gradient effect. The governing equations and boundary conditions are derived both in dimensional and dimensionless form by employed the Hamilton principle. The analytical solutions based on different continuum theories are compared. The effect of higher order inertia terms is extremely significant in high frequency range. It is found that there exists an asymptotic frequency for the proposed beam model, while for the nonlocal strain gradient theory the solutions diverge. The effect of strain gradient field in thickness direction is significant in low frequencies domain and it cannot be neglected when the material strain length scale parameter is considerable with beam thickness. The influence of each of three size effect parameters on the natural frequencies are investigated. The natural frequencies increase with the increasing material strain gradient length scale parameter or decreasing velocity gradient length scale parameter and nonlocal parameter.

Keywords: Euler-Bernoulli Beams, free vibration, higher order inertia, Nonlocal Strain Gradient Theory, velocity gradient

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Authors: Devendra Gupta, Vikash Arya, Prabhat K. Singh

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Background: Ultrasound guidance could be beneficial in placing central venous catheters by improving the success rate, reducing the number of needle passes, and decreasing complications. Central venous cannulation set has a single puncture needle of a fixed length of 6.4 cm. However, the average distance of midpoint of IJV to the skin is around 1 cm to 2 cm. The long length needle has tendency to go in depth more than required and this is very common during learning period of any individual. Therefore, we devised a long needle with a guard which can be adjusted according to the required length. Methods: After approval from the institute ethics committee and patient’s written informed consent, a prospective, randomized, single-blinded controlled study was conducted. Adult patient aged of both sexes with ASA grade 1-2 undergoing surgery requiring internal jugular venous (IJV) access was included. After intubation, the head was rotated to the contralateral side at 30 degree head rotation on the position of the right IJV. The transducer probe a 6.5 to 13-MHz linear transducer (Sonosite, USA) had been placed at the apex of triangle with minimal pressure to avoid IJV compression. The distance from skin to midpoint of the right IJV and skin to anterior wall of Common Carotid Artery (CCA) had been done using B-mode duplex sonography with a 6.5 to 13-MHz linear transducer. Depending upon the results of randomization 420 patients had been divided into two groups of equal numbers (n=210). Group 1. USG guided right sided IJV cannulation was done with conventional (6.4 cm) needle; and Group 2. USG guided right sided IJV cannulation was done with conventional (6.4 cm) needle with guard fixed to a required length (length between skin and midpoint of IJV) by an experienced anesthesiologist. Independent observer has noted the number of attempts and occurrence of complications (CCA puncture, pneumothorax or adjacent tissue damage). Results: Demographic data were similar in both the group. The groups were comparable when considered for relationship of IJV to CCA. There was no significant difference between groups as regard to distance of midpoint of IJV to the skin (p<0.05). IJV cannulation was successfully done in single attempts in 180 (85.7%), in two attempts in 27 (12.9%) and three attempts in 3 (1.4%) in group I, whereas in single attempt in 207 (98.6%) and second attempts in 3 (1.4%) in group II (p <0.000). Incidence of carotid artery puncture was significantly more in group I (7.1%) compared to group II (0%) (p<0.000). Incidence of adjacent tissue puncture was significantly more in group I (8.6%) compared to group II (0%) (p<0.000). Conclusion: Therefore IJV catheterization using guard over the needle at predefined length with the help of real-time ultrasound results in better success rates and lower immediate complications.

Keywords: ultrasound guided, internal jugular vein cannulation, measured guided needle, common carotid artery puncture

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Authors: Sérgio Afonso Mulema, Andrés Carrión García, Vicente Ernesto

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This paper analyses the effect of fertilizer (organic and inorganic) in the growth of tilapia. An experiment was implemented in the Aquapesca Company of Mozambique; there were considered four different treatments. Each type of fertilizer was applied in two of these treatments; a feed was supplied to the third treatment, and the fourth was taken as control. The weight and length of the tilapia were used as the growth parameters, and to measure the water quality, the physical-chemical parameters were registered. The results show that the weight and length were different for tilapias cultivated in different treatments. These differences were evidenced mainly by organic and feed treatments, where there was the largest and smallest value of these parameters, respectively. In order to prove that these differences were caused only by applied treatment without interference for the aquatic environment, a Fisher discriminant analysis was applied, which confirmed that the treatments were exposed to the same environment condition.

Keywords: fertilizer, tilapia, growth, statistical methods

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Authors: Mahendran Samykano, Ram Mohan, Shyam Aravamudhan

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The objective of this work is to study the effect of two key factors-external magnetic field and applied current density during the template-based electrodeposition of nickel nanowires using an electrode distance of 20 mm. Morphology, length, crystallite size, and crystallographic characterization of the grown nickel nanowires at an electrode distance of 20mm are presented. For this electrode distance of 20 mm, these two key electrodeposition factors when coupled was found to reduce crystallite size with a higher growth length and preferred orientation of Ni crystals. These observed changes can be inferred to be due to coupled interaction forces induced by the intensity of applied electric field (current density) and external magnetic field known as magnetohydrodynamic (MHD) effect during the electrodeposition process.

Keywords: anodic alumina oxide, electrodeposition, nanowires, nickel

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Authors: Qin Yang, Fan Zhang, Juan Du, Chongkui Sun, Krishna Kota, Yun-Ling Zheng

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Telomeres are specialized structures at chromosome ends consisting of tandem repetitive DNA sequences [(TTAGGG)n in humans] and associated proteins, which are necessary for telomere function. Telomere lengths are tightly regulated within a narrow range in normal human somatic cells, the basis of cellular senescence and aging. Previous studies have extensively focused on how short telomeres are extended and have demonstrated that telomerase plays a central role in telomere maintenance through elongating the short telomeres. However, the molecular mechanisms of regulating excessively long telomeres are unknown. Here, we found that telomerase enzymatic component hTERT plays a dual role in the regulation of telomeres length. We analyzed single telomere alterations at each chromosomal end led to the discoveries that hTERT shortens excessively long telomeres and elongates short telomeres simultaneously, thus maintaining the optimal telomere length at each chromosomal end for an efficient protection. The hTERT-mediated telomere shortening removes large segments of telomere DNA rapidly without inducing telomere dysfunction foci or affecting cell proliferation, thus it is mechanistically distinct from rapid telomere deletion. We found that expression of hTERT generates telomeric circular DNA, suggesting that telomere homologous recombination may be involved in this telomere shortening process. Moreover, the hTERT-mediated telomere shortening is required its enzymatic activity, but telomerase RNA component hTR is not involved in it. Furthermore, shelterin protein TPP1 interacts with hTERT and recruits it on telomeres to mediate telomere shortening. In addition, telomere-associated proteins, DKC1 and TCAB1 also play roles in this process. This novel hTERT-mediated telomere shortening mechanism not only exists in cancer cells, but also in primary human cells. Thus, the hTERT-mediated telomere shortening is expected to shift the paradigm on current molecular models of telomere length maintenance, with wide-reaching consequences in cancer and aging fields.

Keywords: aging, hTERT, telomerase, telomeres, human cells

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Authors: Nader Khalafian, Mohsen Ghaderi

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Field observations have revealed many examples of structures which were damaged due to ground surface deformation caused by the faulting phenomena. In this paper some efforts were made in order to estimate the length and location of the ground surface where large displacements were created due to the reverse faulting. This research has conducted in two steps; (1) in the first step, a 2D explicit finite element model were developed using ABAQUS software. A subroutine for Mohr-Coulomb failure criterion with strain softening model was developed by the authors in order to properly model the stress strain behavior of the soil in the fault rapture zone. The results of the numerical analysis were verified with the results of available centrifuge experiments. Reasonable coincidence was found between the numerical and experimental data. (2) In the second step, the effects of the fault dip angle (δ), depth of soil layer (H), dilation and friction angle of sand (ψ and φ) and the amount of fault offset (d) on the soil surface displacement and fault rupture path were investigated. An artificial neural network-based model (ANN), as a powerful prediction tool, was developed to generate a general model for predicting faulting characteristics. A properly sized database was created to train and test network. It was found that the length and location of the zone of displaced ground surface can be accurately estimated using the proposed model.

Keywords: reverse faulting, surface deformation, numerical, neural network

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Authors: Rohit Shrivastava, Stefan Luding

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A mechanical wave is propagation of vibration with transfer of energy and momentum. Studying the energy as well as spectral energy characteristics of a propagating wave through disordered granular media can assist in understanding the overall properties of wave propagation through inhomogeneous materials like soil. The study of these properties is aimed at modeling wave propagation for oil, mineral or gas exploration (seismic prospecting) or non-destructive testing for the study of internal structure of solids. The study of Energy content (Kinetic, Potential and Total Energy) of a pulse propagating through an idealized one-dimensional discrete particle system like a mass disordered granular chain can assist in understanding the energy attenuation due to disorder as a function of propagation distance. The spectral analysis of the energy signal can assist in understanding dispersion as well as attenuation due to scattering in different frequencies (scattering attenuation). The selection of one-dimensional granular chain also helps in studying only the P-wave attributes of the wave and removing the influence of shear or rotational waves. Granular chains with different mass distributions have been studied, by randomly selecting masses from normal, binary and uniform distributions and the standard deviation of the distribution is considered as the disorder parameter, higher standard deviation means higher disorder and lower standard deviation means lower disorder. For obtaining macroscopic/continuum properties, ensemble averaging has been used. Interpreting information from a Total Energy signal turned out to be much easier in comparison to displacement, velocity or acceleration signals of the wave, hence, indicating a better analysis method for wave propagation through granular materials. Increasing disorder leads to faster attenuation of the signal and decreases the Energy of higher frequency signals transmitted, but at the same time the energy of spatially localized high frequencies also increases. An ordered granular chain exhibits ballistic propagation of energy whereas, a disordered granular chain exhibits diffusive like propagation, which eventually becomes localized at long periods of time.

Keywords: discrete elements, energy attenuation, mass disorder, granular chain, spectral energy, wave propagation

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Authors: Victor U. Odoemelam, Ihemdirim C. Unamba-Opara, Martins C. Anyanwuocha

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Antibiotics used as growth promoters in animal feeds have been criticized and banned in many nations due to possible development of both drug resistance, cross resistance and multiple resistances by consumers. Numerous additives are now being used or proposed as alternatives. A study to compare the effects of Ocimum gratissimum (Scent leaf) and antibiotic growth promoter (Oxytetracycline HCl) on growth performance and intestinal morphology of starter broiler birds was conducted using ninety six (96) days old broiler birds. The birds were randomly assigned to four treatments with each treatment comprising 24 birds replicated three times with 8 birds per replicate in a completely randomized design experiment. Four diets (T1 control diet without Oxytetracycline HCl and Ocimum gratissimum; T2 had Oxytetracycline HCl; T3 had 1% Ocimum gratissimum; T4 had 1.5% Ocimum gratissimum) were formulated and offered ad libitum to the respective birds. Data was collected on feed intake, body weight gain and feed conversion ratio (FCR) also Jejenal sections of the intestine were collected for examination of Villi length and Crypt depth at the end of starter phase. Results show that there were no significant difference (P>0.05) observed in feed intake and final body weight. However, feed conversion ratio (FCR) and daily weight gain significantly differed (P<0.05). T1, T2, and T4 were similar, however T2 differed (P<0.05) from T3. FCR followed the same pattern. Dietary treatment significantly (P<0.05) affected Villi length, Crypt depth and Villi length/crypt depth ratio. Birds fed OG containing diets, had significantly higher (P<0.05) villi length/crypt depth ratio. However, this did not translate to a significantly higher body weight gain or feed conversion ratio. It can be concluded that O. gratissimum can replace antibiotic growth promoter (Oxytetracycline HCl) since their effect on performance were similar.

Keywords: antibiotics, body weight, feed additives, intestinal morphology, phytogenics

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Authors: Ibrahim Aydogdu, Alper Akin

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In this study, the development of minimizing the cost and the CO2 emission of the RC retaining wall design has been performed by Biogeography Based Optimization (BBO) algorithm. This has been achieved by developing computer programs utilizing BBO algorithm which minimize the cost and the CO2 emission of the RC retaining walls. Objective functions of the optimization problem are defined as the minimized cost, the CO2 emission and weighted aggregate of the cost and the CO2 functions of the RC retaining walls. In the formulation of the optimum design problem, the height and thickness of the stem, the length of the toe projection, the thickness of the stem at base level, the length and thickness of the base, the depth and thickness of the key, the distance from the toe to the key, the number and diameter of the reinforcement bars are treated as design variables. In the formulation of the optimization problem, flexural and shear strength constraints and minimum/maximum limitations for the reinforcement bar areas are derived from American Concrete Institute (ACI 318-14) design code. Moreover, the development length conditions for suitable detailing of reinforcement are treated as a constraint. The obtained optimum designs must satisfy the factor of safety for failure modes (overturning, sliding and bearing), strength, serviceability and other required limitations to attain practically acceptable shapes. To demonstrate the efficiency and robustness of the presented BBO algorithm, the optimum design example for retaining walls is presented and the results are compared to the previously obtained results available in the literature.

Keywords: bio geography, meta-heuristic search, optimization, retaining wall

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Authors: Alex Fedoseyev

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This study investigates a generalized hydrodynamic equation (GHE) simplified model for the simulation of turbulent flow over a two-dimensional backward-facing step (BFS) at Reynolds number Re=132000. The GHE were derived from the generalized Boltzmann equation (GBE). GBE was obtained by first principles from the chain of Bogolubov kinetic equations and considers particles of finite dimensions. The GHE has additional terms, temporal and spatial fluctuations, compared to the Navier-Stokes equations (NSE). These terms have a timescale multiplier τ, and the GHE becomes the NSE when $\tau$ is zero. The nondimensional τ is a product of the Reynolds number and the squared length scale ratio, τ=Re*(l/L)², where l is the apparent Kolmogorov length scale, and L is a hydrodynamic length scale. The BFS flow modeling results obtained by 2D calculations cannot match the experimental data for Re>450. One or two additional equations are required for the turbulence model to be added to the NSE, which typically has two to five parameters to be tuned for specific problems. It is shown that the GHE does not require an additional turbulence model, whereas the turbulent velocity results are in good agreement with the experimental results. A review of several studies on the simulation of flow over the BFS from 1980 to 2023 is provided. Most of these studies used different turbulence models when Re>1000. In this study, the 2D turbulent flow over a BFS with height H=L/3 (where L is the channel height) at Reynolds number Re=132000 was investigated using numerical solutions of the GHE (by a finite-element method) and compared to the solutions from the Navier-Stokes equations, k–ε turbulence model, and experimental results. The comparison included the velocity profiles at X/L=5.33 (near the end of the recirculation zone, available from the experiment), recirculation zone length, and velocity flow field. The mean velocity of NSE was obtained by averaging the solution over the number of time steps. The solution with a standard k −ε model shows a velocity profile at X/L=5.33, which has no backward flow. A standard k−ε model underpredicts the experimental recirculation zone length X/L=7.0∓0.5 by a substantial amount of 20-25%, and a more sophisticated turbulence model is needed for this problem. The obtained data confirm that the GHE results are in good agreement with the experimental results for turbulent flow over two-dimensional BFS. A turbulence model was not required in this case. The computations were stable. The solution time for the GHE is the same or less than that for the NSE and significantly less than that for the NSE with the turbulence model. The proposed approach was limited to 2D and only one Reynolds number. Further work will extend this approach to 3D flow and a higher Re.

Keywords: backward-facing step, comparison with experimental data, generalized hydrodynamic equations, separation, reattachment, turbulent flow

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Authors: C. Garcia, C. Andreasen

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Sugarcane is an important resource for bioenergy. Fields are usually established by using 15-20 cm pieces of sugarcane stalks as propagation material. An alternative method is to use small chips with nodes from sugarcane stalks. Plants from nodes are often established in plastic pots, but plastic pots could be replaced with biodegradable paper pots. This would be a more sustainable solution, reducing labor costs and avoiding pollution with plastic. We compared the establishment of plants from nodes taken from three different part of the sugarcane plant. The nodes were planted in plastic and paper pots. There was no significant difference between plants established in the two pot types. Nodes from different part of the stalk had different sprouting capacity. Nodes from the top parts sprouted significantly better than nodes taken from the middle or nodes taken closed to the ground in two experiments. Nodes with a length of 3 cm performed better than nodes with a length of 2 cm.

Keywords: nodes, paper pots, propagation material, sugarcane

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Authors: Ahmed Bakry, Moustafa Ahmed

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We model and simulate the combined effect of fiber dispersion and frequency chirp of a directly modulated high-speed laser diode on the figures of merit of a non-amplified 40-Gbps optical fiber link. We consider both the return to zero (RZ) and non-return to zero (NRZ) patterns of the pseudorandom modulation bits. The performance of the fiber communication system is assessed by the fiber-length limitation due to the fiber dispersion. We study the influence of replacing standard single-mode fibers by non-zero dispersion-shifted fibers on the maximum fiber length and evaluate the associated power penalty. We introduce new dispersion tolerances for 1-dB power penalty of the RZ and NRZ 40-Gbps optical fiber links.

Keywords: bit error rate, dispersion, frequency chirp, fiber communications, semiconductor laser

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Authors: I. Sinnarasa, Y. Thimont, L. Presmanes, A. Barnabé

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The thermoelectricity is a promising technique to overcome the issues in recovering waste heat to electricity without using moving parts. In fact, the thermoelectric (TE) effect defines as the conversion of a temperature gradient directly into electricity and vice versa. To optimize TE materials, the power factor (PF = σS² where σ is electrical conductivity and S is Seebeck coefficient) must be increased by adjusting the carrier concentration, and/or the lattice thermal conductivity Kₜₕ must be reduced by introducing scattering centers with point defects, interfaces, and nanostructuration. The PF does not show the advantages of the thin film because it does not take into account the thermal conductivity. In general, the thermal conductivity of the thin film is lower than the bulk material due to their microstructure and increasing scattering effects with decreasing thickness. Delafossite type oxides CuᴵMᴵᴵᴵO₂ received main attention for their optoelectronic properties as a p-type semiconductor they exhibit also interesting thermoelectric (TE) properties due to their high electrical conductivity and their stability in room atmosphere. As there are few proper studies on the TE properties of Mg-doped CuCrO₂ thin films, we have investigated, the influence of the annealing temperature on the electrical conductivity and the Seebeck coefficient of Mg-doped CuCrO₂ thin films and calculated the PF in the temperature range from 40 °C to 220 °C. For it, we have deposited Mg-doped CuCrO₂ thin films on fused silica substrates by RF magnetron sputtering. This study was carried out on 300 nm thin films. The as-deposited Mg doped CuCrO₂ thin films have been annealed at different temperatures (from 450 to 650 °C) under primary vacuum. Electrical conductivity and Seebeck coefficient of the thin films have been measured from 40 to 220 °C. The highest electrical conductivity of 0.60 S.cm⁻¹ with a Seebeck coefficient of +329 µV.K⁻¹ at 40 °C have been obtained for the sample annealed at 550 °C. The calculated power factor of optimized CuCrO₂:Mg thin film was 6 µW.m⁻¹K⁻² at 40 °C. Due to the constant Seebeck coefficient and the increasing electrical conductivity with temperature it reached 38 µW.m⁻¹K⁻² at 220 °C that was a quite good result for an oxide thin film. Moreover, the degenerate behavior and the hopping mechanism of CuCrO₂:Mg thin film were elucidated. Their high and constant Seebeck coefficient in temperature and their stability in room atmosphere could be a great advantage for an application of this material in a high accuracy temperature measurement devices.

Keywords: thermoelectric, oxides, delafossite, thin film, power factor, degenerated semiconductor, hopping mode

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Authors: Raihana Abdul Wahab, Norihan Kadir, Muhamad Hazwan Mustafa

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The determination of accurate times for Fajr and Dhuha prayers in Malaysia is faced with issues of differing views in the fixation of the parameters of the sun’s altitude used in the calculation of astronomy, especially in Malaysia. Therefore, this study aims to identify issues and problems in the methods used in determining the accurate times for both these prayers through a literature review of previous research studies. The results show the need to review the parameters of sun altitude used in calculating prayer times for both these prayers through observations in changes in the brightness of the early morning light for distinguish of true dawn and false dawn for the Fajr prayers and the length of the shadow for Dhuha payer by collecting data from all the states throughout Malaysia.

Keywords: fajr, Dhuha, sky brightness, length of shadows, astronomy, Islamic jurisprudence

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Authors: Marek Kociuba, Jarosław Kurek

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Introduction: The digit length ratio (2D:4D) is generally higher in women compared to men. Lower 2D:4D is linked with greater physical ability, strength, and better sporting performance. Second-to-fourth digit lengths ratio (2D:4D) is an indicator of PT exposure. Lower 2D:4D indicates higher PT exposure and vice versa. Methods: The objectives of this paper were to investigate the relationship of 2D:4D with physical fitness in men and women. The study compared 137 female and 174 male students from Wrocław. Besides calculating 2D:4D for each hand, height and weight were also recorded. Assessment of physical fitness and endurance were performed through Eurofit tests. Handgrip strength was measured by a standardized isometric dynamometer. Results: Male participants had significantly lower 2D:4D than females on each hand. A weak relationship between 2D:4D and the results of strength tests was found.

Keywords: 2D:4D, physical fitness, prenatal testosterone, sexual dimorphism

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Authors: Erjola Reufi, Jozefita Marku, Thomas Bier

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Ultrasonic pulse velocity (UPV) method has been shown for some time to provide a reliable means of estimating properties and offers a unique opportunity for direct, quick and safe control of building damaged by earthquake, fatigue, conflagration and catastrophic scenarios. On this investigation hybrid reinforced concrete has been investigated by UPV method. Hooked end steel fiber of length 50 and 30 mm was added to concrete in different proportion 0, 0.25, 0.5, and 1 % by the volume of concrete. On the other hand, polypropylene fiber of length 12, 6, 3 mm was added to concrete of 0.1, 0.2, and 0.4 % by the volume of concrete. Fifteen different mixture has been prepared to investigate the relation between compressive strength and UPV values and also to investigate on the effect of volume and type of fiber on UPV values.

Keywords: compressive strength, polypropylene fiber, steel fiber, ultrasonic pulse velocity, volume, type of fiber

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Authors: Elena B. Cherepetskaya, Alexander A. Karabutov, Natalia B. Podymova, Ivan Sas

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Nonlinear evolution of broadband ultrasonic pulses passed through the rock specimens is studied using the apparatus ‘GEOSCAN-02M’. Ultrasonic pulses are excited by the pulses of Q-switched Nd:YAG laser with the time duration of 10 ns and with the energy of 260 mJ. This energy can be reduced to 20 mJ by some light filters. The laser beam radius did not exceed 5 mm. As a result of the absorption of the laser pulse in the special material – the optoacoustic generator–the pulses of longitudinal ultrasonic waves are excited with the time duration of 100 ns and with the maximum pressure amplitude of 10 MPa. The immersion technique is used to measure the parameters of these ultrasonic pulses passed through a specimen, the immersion liquid is distilled water. The reference pulse passed through the cell with water has the compression and the rarefaction phases. The amplitude of the rarefaction phase is five times lower than that of the compression phase. The spectral range of the reference pulse reaches 10 MHz. The cubic-shaped specimens of the Karelian gabbro are studied with the rib length 3 cm. The ultimate strength of the specimens by the uniaxial compression is (300±10) MPa. As the reference pulse passes through the area of the specimen without cracks the compression phase decreases and the rarefaction one increases due to diffraction and scattering of ultrasound, so the ratio of these phases becomes 2.3:1. After preloading some horizontal cracks appear in the specimens. Their location is found by one-sided scanning of the specimen using the backward mode detection of the ultrasonic pulses reflected from the structure defects. Using the computer processing of these signals the images are obtained of the cross-sections of the specimens with cracks. By the increase of the reference pulse amplitude from 0.1 MPa to 5 MPa the nonlinear transformation of the ultrasonic pulse passed through the specimen with horizontal cracks results in the decrease by 2.5 times of the amplitude of the rarefaction phase and in the increase of its duration by 2.1 times. By the increase of the reference pulse amplitude from 5 MPa to 10 MPa the time splitting of the phases is observed for the bipolar pulse passed through the specimen. The compression and rarefaction phases propagate with different velocities. These features of the powerful broadband ultrasonic pulses passed through the rock specimens can be described by the hysteresis model of Preisach-Mayergoyz and can be used for the location of cracks in the optically opaque materials.

Keywords: cracks, geological materials, nonlinear evolution of ultrasonic pulses, rock

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Authors: Hyun-Kyu Cho, Jun-Su Kim, Choon-Geun Huh, Geon Lee Young-Chul Park

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In this study, the relationship between flow properties and fluid projection distance look into connection for shape variations of foam monitor. A numerical analysis technique for fluid analysis of a foam monitor was developed for the prediction. Shape of foam monitor the flow path of fluid flow according to the shape, The fluid losses were calculated from flow analysis result.. The modified model used the length increase model of the flow path, and straight line of the model. Inlet pressure was 7 [bar] and external was atmosphere codition. am. The results showed that the length increase model of the flow path and straight line of the model was improved in the nozzle projection distance.

Keywords: injection performance, finite element method, foam monitor, Projection distance

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Authors: Piyali Mukherjee, Jai Prakash Keshri

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Anticipated shortages of raw materials for paper industry have forged the entry of algae as alternatives to wood pulp. Five algal species: Pithophora sp., Lyngbya sp., Hydrodictyon sp., Cladophora sp. and Rhizoclonium sp. were collected from different parts of Burdwan town, West Bengal, India. Their biomass compositional values were determined with respect to eucalyptus wood pulp. Paper characteristics were studied in terms of breaking length, tensile strength, CI index, pH, brightness, recyclability, and durability. Hydrodictyon sp., besides Rhizoclonium sp. and Cladophora sp. were established as the most suitable candidates for paper pulp formulation in terms of high cellulose, hemicelluloses contents and low lignin and silica contents. Paper from pure Hydrodictyon sp. pulp was found to have statistically significant (p < 0.05) improved breaking-length and tensile strength properties compared to that obtained from Lyngbya sp.

Keywords: algae, biomass, paper, pulp, wood

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Authors: S. Zenia, A. Menasseria, A. E. Kheidous, F. Lariouna, A. Smai, H. Saadi, F. Haddadj, A. Milla, F. Marniche

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The objective of this study was to estimate the correlation ship between different pheasant external egg quality traits. A total of 938 eggs were collected. Egg weight (g), egg length (mm), egg width (mm), volume (cm3), shape index egg, surface area and water loss were measured. The overall mean values obtained for the different variables are respectively 29.2 ± 2,24, 43.01 ± 1,84, 34.05 ± 1,44, 25.63 ± 2.88 cm3, 79.00 ± 3%, 68% and 13%. Concerning studied regressions, it was considered only the most important regressions. Those that show significant links between the different parameters studied. The ANOVA procedure was applied to estimate correlations for the examined traits. The weights of the eggs being observed before incubation and before hatching are linearly correlated with a positive correlation coefficient of order 0.75. Egg length and the weight before incubation had a good and positive correlation with a coefficient r = 0.6. However, density had high and negative correlations with egg height r = -0.78. Shape index had a good linear and negative r= - 0.71 correlation with water loss.

Keywords: correlation, egg, morphometry of eggs, analysis of variance

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Authors: Erwin, Cheng-Cheng Chen, Charles J. Salim

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One of the method to solve the lateral torsional buckling (LTB) problem is by using side plates to increased the buckling resistance of the beam. Some modifications in designing the side plates are made in this study to simplify the construction in the field and reduce the cost. At certain region, side plates are not added: (1) At the beam end to preserve some spaces for bolt installation, but the beam is strengthened by adding cover plate at both flanges and (2) at the middle span of the beam where the moment is smaller. Three small scale full span beam specimens are tested under cyclic loading to investigate the LTB resistant and the ductility of the proposed design method. Test results show that the LTB deformation can be effectively suppressed and very high ductility level can be achieved. Following the test, a finite element analysis (FEA) model is established and is verified using the test results. An intensive parametric study is conducted using the established FEA model. The analysis reveals that the length of side plates is the most important parameter determining the performance of the beam and the required side plates length is determined by some parameters which are (1) beam depth to flange width ratio, (2) beam slenderness ratio (3) strength and thickness of the side plates, (4) compactness of beam web and flange, and (5) beam yield strength. At the end of the paper, a design formula to calculate the required side plate length is suggested.

Keywords: cover plate, earthquake resistant design, lateral torsional buckling, side plate, steel structure

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Authors: Priscila A. Bernardes, Marcos E. Buzanskas, Luciana C. A. Regitano, Ricardo V. Ventura, Danisio P. Munari

Abstract:

The best linear unbiased predictor (BLUP) is a method commonly used in genetic evaluations of breeding programs. However, this approach can lead to higher inbreeding coefficients in the population due to the intensive use of few bulls with higher genetic potential, usually presenting some degree of relatedness. High levels of inbreeding are associated to low genetic viability, fertility, and performance for some economically important traits and therefore, should be constantly monitored. Unreliable pedigree data can also lead to misleading results. Genomic information (i.e., single nucleotide polymorphism – SNP) is a useful tool to estimate the inbreeding coefficient. Runs of homozygosity have been used to evaluate homozygous segments inherited due to direct or collateral inbreeding and allows inferring population selection history. This study aimed to evaluate runs of homozygosity (ROH) and inbreeding in a population of Nelore beef cattle. A total of 814 animals were genotyped with the Illumina BovineHD BeadChip and the quality control was carried out excluding SNPs located in non-autosomal regions, with unknown position, with a p-value in the Hardy-Weinberg equilibrium lower than 10⁻⁵, call rate lower than 0.98 and samples with the call rate lower than 0.90. After the quality control, 809 animals and 509,107 SNPs remained for analyses. For the ROH analysis, PLINK software was used considering segments with at least 50 SNPs with a minimum length of 1Mb in each animal. The inbreeding coefficient was calculated using the ratio between the sum of all ROH sizes and the size of the whole genome (2,548,724kb). A total of 25.711 ROH were observed, presenting mean, median, minimum, and maximum length of 3.34Mb, 2Mb, 1Mb, and 80.8Mb, respectively. The number of SNPs present in ROH segments varied from 50 to 14.954. The longest ROH length was observed in one animal, which presented a length of 634Mb (24.88% of the genome). Four bulls were among the 10 animals with the longest extension of ROH, presenting 11% of ROH with length higher than 10Mb. Segments longer than 10Mb indicate recent inbreeding. Therefore, the results indicate an intensive use of few sires in the studied data. The distribution of ROH along the chromosomes showed that chromosomes 5 and 6 presented a large number of segments when compared to other chromosomes. The mean, median, minimum, and maximum inbreeding coefficients were 5.84%, 5.40%, 0.00%, and 24.88%, respectively. Although the mean inbreeding was considered low, the ROH indicates a recent and intensive use of few sires, which should be avoided for the genetic progress of breed.

Keywords: autozygosity, Bos taurus indicus, genomic information, single nucleotide polymorphism

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Authors: Yuanrui Xu, Zailin Yang, Yunqiu Song, Guanxixi Jiang

Abstract:

It is an important subject of seismology on the influence of local topography on ground motion during earthquake. In mountainous areas with complex terrain, the construction of the tunnel is often the most effective transportation scheme. In these projects, the local terrain can be simplified into hills with different shapes, and the underground tunnel structure can be regarded as a subsurface cavity. The presence of the subsurface cavity affects the strength of the rock mass and changes the deformation and failure characteristics. Moreover, the scattering of the elastic waves by underground structures usually interacts with local terrains, which leads to a significant influence on the surface displacement of the terrains. Therefore, it is of great practical significance to study the surface displacement of local terrains with underground tunnels in earthquake engineering and seismology. In this work, the region is divided into three regions by the method of region matching. By using the fractional Bessel function and Hankel function, the complex function method, and the wave function expansion method, the wavefield expression of SH waves is introduced. With the help of a constitutive relation between the displacement and the stress components, the hoop stress and radial stress is obtained subsequently. Then, utilizing the continuous condition at different region boundaries, the undetermined coefficients in wave fields are solved by the Fourier series expansion and truncation of the finite term. Finally, the validity of the method is verified, and the surface displacement amplitude is calculated. The surface displacement amplitude curve is discussed in the numerical results. The results show that different parameters, such as radius and buried depth of the tunnel, wave number, and incident angle of the SH wave, have a significant influence on the amplitude of surface displacement. For the underground tunnel, the increase of buried depth will make the response of surface displacement amplitude increases at first and then decreases. However, the increase of radius leads the response of surface displacement amplitude to appear an opposite phenomenon. The increase of SH wave number can enlarge the amplitude of surface displacement, and the change of incident angle can obviously affect the amplitude fluctuation.

Keywords: method of region matching, scattering of SH wave, subsurface cavity, trapezoidal hill

Procedia PDF Downloads 134

Authors: Joseph J. Okoh, Samuel T. Mbap, Tahir Ibrahim, Yusuf P. Mancha

Abstract:

The influence of plumage colour on measurable attributes of 6176 adult indigenous chickens of mixed-sex from four states of the North Central Zone of Nigeria namely; Nasarawa, Niger, Benue, Kogi and the Federal Capital Territory (FCT) Abuja were assessed. The overall average body weight of the chickens was 1.95 ± 0.03kg. The body weights of black, white, black/white, brown, black/brown, grey and mottled chicken however were 1.87 ± 0.04, 1.94 ± 0.04, 1.95 ± 0.03, 1.93 ± 0.03, 2.01 ± 0.04, 1.96 ± 0.04 and 1.94±0.14kg respectively. Only body length did not vary by plumage colour. The others; body weight and width, shank, comb and breast length, breast height (p < 0.001), beak and wing lengths (p < 0.001) varied significantly. Generally, no colour was outrightly superior to others in all body measurements. However, body weight and breast height were both highest in black/brown chickens which also had the second highest breast length. Body width, shank, beak, comb and wing lengths were highest in grey chickens but lowest in those with white colour and combinations. Egg quality was on the other hand mostly lowest in grey chickens. In selection for genetic improvement in body measurements, black/brown and grey chickens should be favoured. However, in view of the known negative relationship between body weight and egg attributes, selection in favour of grey plumage may result in chickens of poor egg attributes. Therefore, grey chickens should be selected against egg quality.

Keywords: body weight, indigenous chicken, measurements, plumage colour

Procedia PDF Downloads 128

Authors: Anne M. Denton, Rahul Gomes, David W. Franzen

Abstract:

High-resolution elevation data are becoming increasingly available, but typical approaches for computing topographic features, like slope and curvature, still assume small sliding windows, for example, of size 3x3. That means that the digital elevation model (DEM) has to be resampled to the scale of the landform features that are of interest. Any higher resolution is lost in this resampling. When the topographic features are computed through regression that is performed at the resolution of the original data, the accuracy can be much higher, and the reported result can be adjusted to the length scale that is relevant locally. Slope and variance are calculated for overlapping windows, meaning that one regression result is computed per raster point. The number of window centers per area is the same for the output as for the original DEM. Slope and variance are computed by performing regression on the points in the surrounding window. Such an approach is computationally feasible because of the additive nature of regression parameters and variance. Any doubling of window size in each direction only takes a single pass over the data, corresponding to a logarithmic scaling of the resulting algorithm as a function of the window size. Slope and variance are stored for each aggregation step, allowing the reported slope to be selected to minimize variance. The approach thereby adjusts the effective window size to the landform features that are characteristic to the area within the DEM. Starting with a window size of 2x2, each iteration aggregates 2x2 non-overlapping windows from the previous iteration. Regression results are stored for each iteration, and the slope at minimal variance is reported in the final result. As such, the reported slope is adjusted to the length scale that is characteristic of the landform locally. The length scale itself and the variance at that length scale are also visualized to aid in interpreting the results for slope. The relevant length scale is taken to be half of the window size of the window over which the minimum variance was achieved. The resulting process was evaluated for 1-meter DEM data and for artificial data that was constructed to have defined length scales and added noise. A comparison with ESRI ArcMap was performed and showed the potential of the proposed algorithm. The resolution of the resulting output is much higher and the slope and aspect much less affected by noise. Additionally, the algorithm adjusts to the scale of interest within the region of the image. These benefits are gained without additional computational cost in comparison with resampling the DEM and computing the slope over 3x3 images in ESRI ArcMap for each resolution. In summary, the proposed approach extracts slope and aspect of DEMs at the lengths scales that are characteristic locally. The result is of higher resolution and less affected by noise than existing techniques.

Keywords: high resolution digital elevation models, multi-scale analysis, slope calculation, window-based regression

Procedia PDF Downloads 129

Authors: Wan-Hsin Hsieh, Chieh-Fu Chang, Ming-Seng Kao

Abstract:

In this paper, a novel method termed the Phase Coherence Acquisition (PCA) is proposed for pseudo-random (PN) sequence acquisition. By employing complex phasors, the PCA requires only complex additions in the order of N, the length of the sequence, whereas the conventional method utilizing fast Fourier transform (FFT) requires complex multiplications and additions both in the order of Nlog2N . In order to combat noise, the input and local sequences are partitioned and mapped into complex phasors in PCA. The phase differences between pairs of input and local phasors are utilized for acquisition, and thus complex multiplications are avoided. For more noise-robustness capability, the multi-layer PCA is developed to extract the code phase step by step. The significant reduction of computational loads makes the PCA an attractive method, especially when the sequence length of is extremely large which becomes intractable for the FFT-based acquisition.

Keywords: FFT, PCA, PN sequence, convolution theory

Procedia PDF Downloads 478

Authors: W. Mohammedsaeed, A. J. Mcbain, S. M. Cruickshank, C. A. O’Neill

Abstract:

Many studies have demonstrated the importance of probiotics and their potential therapeutic effects within the gut. Recently, the possible therapeutic effects of probiotics in other tissues have also begun to be investigated. Comparatively few studies have evaluated the use of topical probiotics in relation to the skin. In this study, we have conducted preliminary investigations into whether a well-known probiotic, Lactobacillus rhamnosus GG (LGG), can increase the rate of re-epithelialization in a model wound. Full-thickness skin was obtained from individuals undergoing elective cosmetic surgery. This skin was wounded using excisional punch and cultured using a serum-free medium, either in the presence or absence of L. rhamnosus GG lysate. Histological staining of the sections was performed with Haematoxylin& Eosin E to quantify “epithelial tongue length”. This is the length of the new epithelial ‘tongue’ that grows and covers the exposed dermis at the inner wound edges. The length of the new epithelial ‘tongue’ was compared in untreated section and section treated with and L. rhamnosus GG made using108CFU/ml bacterial cells. L. rhamnosus GG lysate enhanced significantly the re-epithelialisation of treated wounds compared with that of untreated wounds (P=0.005, n=3). Tongue length, at day 1 was 7.55μm 0.15, at day 3 it was 18.5μm 0.25 and at day 7 was 22.9μm 0.35. These results can be compared with untreated cultures in which tongue length was 3.25μm 0.35, day 3 was 9.65μm 0.25 and day 7 was 13.5μm 0.15 post-wounding. In ex-vivo proliferation and migration cells were measured by determining the expression of nuclear proliferation marker Ki-67 and the expression of Phosphorylated cortactin respectively demonstrated that L. rhamnosus GG significantly increased NHEK proliferation and migration rates relative to controls. However, the dominant mechanism was migration because in ex-vivo skin treated with the L. rhamnosus GG up-regulated the gene expression of the chemokine receptor and ligands CXCR2 and CXCL2 comparing with controls (P=0.02, P=0.03 respectively, n=3). High levels of CXCL2/CXCL2 have already been implicated in multiple aspects of stimulation of wound healing through activation of keratinocyte migration. These data demonstrate that lysates from Lactobacillus rhamnosus GG increase re-epithelialization by stimulation of keratinocyte migration. The current study identifies the partial mechanism that contribute to stimulating the wound-healing process ex vivo in response to L. rhamnosus GG lysate is an increase in the production of CXCL2/ CXCR2 in ex vivo models. The use of probiotic lysates potentially offers new options to develop treatments that could improve wound healing.

Keywords: Lactobacillus rhamnosus GG, wounds, migration, lysate

Procedia PDF Downloads 329

Authors: A. Sadeghi, M. Sedghi, M. R. Emami Azadi, R. Gharraei Khosroshahi

Abstract:

Flags are objects with very low bending stiffness and under wind forces start to vibrate and finally to flutter. Even in lower velocities of wind their flutter can be seen. In this research physical property of fabric is determined by performing tensile tests. Then with performing laboratory experiments in wind tunnel, determination of initial flapping speed and also study of displacement amplitude at leech and calculation of their frequency would be targeted. Laboratory tests are performed in a wind tunnel and with different velocities of wind flow for specimens with different dimensions. The results show that extension of specimens' width increase flutter initiation velocity and increase of specimen length decreases it. Also by increasing wind velocity displacement amplitude at leech of specimens are decreased. This displacement has a straight relation with specimens' length and width.

Keywords: flag, flutter, wind velocity, flutter amplitudes, wind tunnel

Procedia PDF Downloads 435