Search results for: square plate

Authors: Maryam Mirzaei, Sinisa Krajnovic´

Abstract:

The paper reports a study about the prediction of flows around simplified vehicles using Partially-Averaged Navier-Stokes (PANS). Numerical simulations are performed for two simplified vehicles: A slanted-back Ahmed body at Re=30 000 and a square back Ahmed body at Re=300 000. A comparison of the resolved and modeled physical flow scales is made with corresponding LES and experimental data for a better understanding of the performance of the PANS model. The PANS model is compared for coarse and fine grid resolutions and it is indicated that even a coarse-grid PANS simulation is able to produce fairly close flow predictions to those from a well-resolved LES simulation. The results indicate the possibility of improvement of the predictions by employing a finer grid resolution.

Keywords: partially-averaged Navier-Stokes, large eddy simulation, PANS, LES, Ahmed body

Procedia PDF Downloads 574

Authors: Shiva Naidoo, Kristena Yossef, Grimm Jimm, Mirza Wasique, Eric Kemmerer, Joshua Obuch, Anand Mahadevan

Abstract:

Background: Fiducial markers effectively enhance tumor target visibility prior to Stereotactic Body Radiation Therapy or Proton therapy. To streamline clinical practice, fiducial placement guidelines from a robotic radiosurgery vendor were examined with the goals of optimizing and standardizing feasible geometries for each treatment indication. Clinical examples of prostate, renal, and pancreatic cases are presented. Methods: Vendor guidelines (Accuray, Sunnyvale, Ca) suggest implantation of 4–6 fiducials at least 20 mm apart, with at least a 15-degree angular difference between fiducials, within 50 mm or less from the target centroid, to ensure that any potential fiducial motion (e.g., from respiration or abdominal/pelvic pressures) will mimic target motion. Also recommended is that all fiducials can be seen in 45-degree oblique views with no overlap to coincide with the robotic radiosurgery imaging planes. For the prostate, a standardized geometry that meets all these objectives is a 2 cm-by-2 cm square in the coronal plane. The transperineal implant of two pairs of preloaded tandem fiducials makes the 2 cm-by-2 cm square geometry clinically feasible. This technique may be applied for renal cancer, except repositioned in a sagittal plane, with the retroperitoneal placement of the fiducials into the tumor. Pancreatic fiducial placement via endoscopic ultrasound (EUS) is technically more challenging, as fiducial placement is operator-dependent, and lesion access may be limited by adjacent vasculature, tumor location, or restricted mobility of the EUS probe in the duodenum. Fluoroscopically assisted fiducial placement during EUS can help ensure fiducial markers are deployed with optimal geometry and visualization. Results: Among the first 22 fiducial cases on a newly installed robotic radiosurgery system, live x-ray images for all nine prostatic cases had excellent fiducial visualization at the treatment console. Renal and pancreatic fiducials were not as clearly visible due to difficult target access and smaller caliber insertion needle/fiducial usage. The geometry of the first prostate case was used to ensure accurate geometric marker placement for the remaining 8 cases. Initially, some of the renal and pancreatic fiducials were closer than the 20 mm recommendation, and interactive feedback with the proceduralists led to subsequent fiducials being too far to the edge of the tumor. Further feedback and discussion of all cases are being used to help guide standardized geometries and achieve ideal fiducial placement. Conclusion: The ideal tradeoffs of fiducial visibility versus the thinnest possible gauge needle to avoid complications needs to be systematically optimized among all patients, particularly in regards to body habitus. Multidisciplinary collaboration among proceduralists and radiation oncologists can lead to improved outcomes.

Keywords: fiducial, prostate cancer, renal cancer, pancreatic cancer, radiotherapy

Procedia PDF Downloads 78

Authors: Waqas Ali

Abstract:

Concrete is broadly used as a structural material in the construction of buildings. When the concrete is exposed to elevated temperature, its strength evaluation is very necessary in the existing structure. In this study, the effect of temperature and the reliability of the core test has been evaluated. For this purpose, the cylindrical cores were extracted from High strength concrete (HSC) specimens that were exposed to the temperature ranging from 300 ℃ to 900 ℃ with a constant duration of 4 hr. This study compares the difference between the standard heated cylinders and the cores taken from them after curing of 90 days. The difference of cylindrical control and binary mix samples and extracted cores revealed that there is 12.19 and 12.38% difference at 300℃, while this difference was found to increase up to 12.89%, 13.03% at 500 ℃. Furthermore, this value is recorded as 12.99%, 13.57% and 14.40%, 14.38% at 700 ℃ and 900 ℃, respectively. A total of four equations were developed through a regression model for the prediction of the strength of concrete for both standard cylinders and extracted cores whose R square values were 0.9733, 0.9627 and 0.9473, 0.9452, respectively.

Keywords: high strength, temperature, core, reliability

Procedia PDF Downloads 61

Authors: Sherif K. El Dyasti, Esam A. Hagras, Adel E. El-Hennawy

Abstract:

This paper addresses the performance of antenna array beam-forming on Chip-Interleaved Code Division Multiple Access (CI_CDMA) system based on Minimum Mean Square Error (MMSE) detector in aeronautical mobile radio channel. Multipath fading, Doppler shifts caused by the speed of the aircraft, and Multiple Access Interference (MAI) are the most important reasons that affect and reduce the performance of aeronautical system. In this paper, we suggested the CI-CDMA with antenna array to combat this fading and improve the bit error rate (BER) performance. We further evaluate the performance of the proposed system in the four standard scenarios in aeronautical mobile radio channel.

Keywords: aeronautical channel, CI-CDMA, beamforming, communication, information

Procedia PDF Downloads 403

Authors: Butta Singh

Abstract:

This paper presents a chaotic map based approach for secured embedding of patient’s confidential data in electrocardiogram (ECG) signal. The chaotic map generates predefined locations through the use of selective control parameters. The sample value difference method effectually hides the confidential data in ECG sample pairs at these predefined locations. Evaluation of proposed method on all 48 records of MIT-BIH arrhythmia ECG database demonstrates that the embedding does not alter the diagnostic features of cover ECG. The secret data imperceptibility in stego-ECG is evident through various statistical and clinical performance measures. Statistical metrics comprise of Percentage Root Mean Square Difference (PRD) and Peak Signal to Noise Ratio (PSNR). Further, a comparative analysis between proposed method and existing approaches was also performed. The results clearly demonstrated the superiority of proposed method.

Keywords: chaotic maps, ECG steganography, data embedding, electrocardiogram

Procedia PDF Downloads 172

Authors: Neda Dekamei, Mostafa Sarabzadeh, Masoumeh Bigdeli

Abstract:

Backward running is commonly used in different sports conditioning, motor learning, and neurological purposes, and even more commonly in physical rehabilitation. The present study evaluated the effects of six weeks backward and forward running methods on balance promotion adaptation in students. 12 male and female preseniors with the age range of 45-60 years participated and were randomly classified into two groups of backward running (n: 6) and forward running (n: 6) training interventions. During six weeks, 3 sessions per week, all subjects underwent stated different models of backward and forward running training on treadmill (65-80 of HR max). Pre and post-tests were performed by force plate and electromyogram, two times before and after intervention. Data were analyzed using by T test. On the basis of obtained data, significant differences were recorded on balance and plantar flexion force in backward running (BR) and no difference for forward running (FR). It seems the training model of backward running can generate more stimulus to achieve better plantar flexion force and strengthening ankle protectors which leads to balance improvement in pre aging period. It can be recommended as an effective method to promote seniors life quality especially in balance neuromuscular parameters.

Keywords: backward running, balance, plantar flexion, pre seniors

Procedia PDF Downloads 146

Authors: Wael M. Bazzi, Amir Rastegarnia, Azam Khalili

Abstract:

In this paper we consider the issue of reliability of measurements in distributed adaptive estimation problem. To this aim, we assume a sensor network with different observation noise variance among the sensors and propose new estimation method based on incremental distributed least mean-square (IDLMS) algorithm. The proposed method contains two phases: I) Estimation of each sensors observation noise variance, and II) Estimation of the desired parameter using the estimated observation variances. To deal with the reliability of measurements, in the second phase of the proposed algorithm, the step-size parameter is adjusted for each sensor according to its observation noise variance. As our simulation results show, the proposed algorithm considerably improves the performance of the IDLMS algorithm in the same condition.

Keywords: adaptive filter, distributed estimation, sensor network, IDLMS algorithm

Procedia PDF Downloads 617

Authors: Vijay Kr. Yadav, Nilam Rathi

Abstract:

Accurate prediction of glucose level for diabetes mellitus is required to avoid affecting the functioning of major organs of human body. This study describes the fundamental assumptions and two different methodologies of the Blood glucose prediction. First is based on the back-propagation algorithm of Artificial Neural Network (ANN), and second is based on the Neuro-Fuzzy technique, called Fuzzy Inference System (FIS). Errors between proposed methods further discussed through various statistical methods such as mean square error (MSE), normalised mean absolute error (NMAE). The main objective of present study is to develop mathematical model for blood glucose prediction before 12 hours advanced using data set of three patients for 60 days. The comparative studies of the accuracy with other existing models are also made with same data set.

Keywords: back-propagation, diabetes mellitus, fuzzy inference system, neuro-fuzzy

Procedia PDF Downloads 239

Authors: Rohit Tripathi, Sumit Tiwari, G. N. Tiwari

Abstract:

In present study, an approach is adopted where photovoltaic thermal flat plate collector is integrated with compound parabolic concentrator. Analytical expression of temperature dependent electrical efficiency of N number of partially covered Photovoltaic Thermal (PVT) - Compound Parabolic Concentrator (CPC) water collector connected in series has been derived with the help of basic thermal energy balance equations. Analysis has been carried for winter weather condition at Delhi location, India. Energy and exergy performance of N - partially covered Photovoltaic Thermal (PVT) - Compound Parabolic Concentrator (CPC) Water collector system has been compared for two cases: (i) 25% area of water collector covered by PV module, (ii) 75% area of water collector covered by PV module. It is observed that case (i) has been best suited for thermal performance and case (ii) for electrical energy as well as overall exergy.

Keywords: compound parabolic concentrator, energy, photovoltaic thermal, temperature dependent electrical efficiency

Procedia PDF Downloads 395

Authors: Rana Rimawi, Ayman Baklizi

Abstract:

Skewed distributions are important models that are frequently used in applications. Generalized distributions form a class of skewed distributions and gain widespread use in applications because of their flexibility in data analysis. More specifically, the Generalized Logistic Distribution with its different types has received considerable attention recently. In this study, based on progressively type-II censored data, we will consider point estimation in type II Generalized Logistic Distribution (Type II GLD). We will develop several estimators for its unknown parameters, including maximum likelihood estimators (MLE), Bayes estimators and linear estimators (BLUE). The estimators will be compared using simulation based on the criteria of bias and Mean square error (MSE). An illustrative example of a real data set will be given.

Keywords: point estimation, type II generalized logistic distribution, progressive censoring, maximum likelihood estimation

Procedia PDF Downloads 186

Authors: Pawan Kumar, Dhananjoy Shaw, Manoj Kumar Rathi

Abstract:

Purpose of the study were to compare between (a) frequencies among the four quartiles of percentile norms of autonomic variables from power events and (b) frequencies among the four quartiles percentile norms of autonomic variables from aerobic events of Indian sportspersons withdrawn from competitive games and sports in regard to number of samples falling in each quartile. The study was conducted on 430 males of 30 to 35 years of age. Based on the nature of game/sports the retired sportspersons were classified into power events (throwers, judo players, wrestlers, short distance swimmers, cricket fast bowlers and power lifters) and aerobic events (long distance runners, long distance swimmers, water polo players). Date was collected using ECG polygraphs. Data were processed and extracted using frequency domain analysis and time domain analysis. Collected data were computed with frequency, percentage of each quartile and finally the frequencies were compared with the chi square analysis. The finding pertaining to norm reference comparison of frequencies among the four quartiles of Indian sportspersons withdrawn from competitive games and sports from (a) power events suggests that frequency distribution in four quartile namely Q1, Q2, Q3, and Q4 are significantly different at .05 level in regard to variables namely, SDNN, Total Power (Absolute Power), HF (Absolute Power), LF (Normalized Power), HF (Normalized Power), LF/HF ratio, deep breathing test, expiratory respiratory ratio, valsalva manoeuvre, hand grip test, cold pressor test and lying to standing test, whereas, insignificantly different at .05 level in regard to variables namely, SDSD, RMSSD, SDANN, NN50 Count, pNN50 Count, LF (Absolute Power) and 30: 15 Ratio (b) aerobic events suggests that frequency distribution in four quartile are significantly different at .05 level in regard to variables namely, SDNN, LF (Normalized Power), HF (Normalized Power), LF/HF ratio, deep breathing test, expiratory respiratory ratio, hand grip test, cold pressor test, lying to standing test and 30: 15 ratio, whereas, insignificantly different at .05 level in regard to variables namely, SDSD, RMSSD. SDANN, NN50 count, pNN50 count, Total Power (Absolute Power), LF(Absolute Power) HF(Absolute Power), and valsalva manoeuvre. The study concluded that comparison of frequencies among the four quartiles of Indian retired sportspersons from power events and aerobic events are different in four quartiles in regard to selected autonomic functions, hence the developed percentile norms are not homogenously distributed across the percentile scale; hence strengthen the percentage distribution towards normal distribution.

Keywords: power, aerobic, absolute power, normalized power

Procedia PDF Downloads 343

Authors: Po-Yuan Tung, Jen-Chueh Kuo, Chia-Ray Chen, Chien-Hsing Li, Kuo-Liang Pan

Abstract:

The main-body structure of satellite is mainly constructed by lightweight material, it should be able to withstand certain vibration load during launches. Since various kinds of change possibility in the space, it is an extremely important work to study the random vibration response of satellite structure. This paper based on the reciprocity relationship between sound and structure response and it will try to evaluate the dynamic response of satellite main body under random acoustic load excitation. This paper will study the technical process and verify the feasibility of sonic-borne vibration analysis. One simple plate exposed to the uniform acoustic field is utilized to take some important parameters and to validate the acoustics field model of the reverberation chamber. Then import both structure and acoustic field chamber models into the vibro-acoustic coupling analysis software to predict the structure response. During the modeling process, experiment verification is performed to make sure the quality of numerical models. Finally, the surface vibration level can be calculated through the modal participation factor, and the analysis results are presented in PSD spectrum.

Keywords: vibration, acoustic, modal, honeycomb panel

Procedia PDF Downloads 547

Authors: Laima Silina, Ilze Gramatina, Liga Skudra, Tatjana Rakcejeva

Abstract:

The aim of the current research was to determine quality parameters changes of dried venison during storage. Protein, fat and moisture content dynamics as well microbiological quality was analyzed. For the experiments the meat (0.02×4.00×7.00 cm) pieces were marinated in “teriyaki sauce” marinade (composition: teriyaki sauce, sweet and sour sauce, taco sauce, soy sauce, American BBQ sauce hickory, sesame oil, garlic, garlic salt, tabasco red pepper sauce) at 4±2°C temperature for 48±1h. Sodium monophosphate (E339) was also added in part of marinade to improve the meat textural properties. After marinating, meat samples were dried in microwave-vacuum drier MUSSON–1, packaged in vacuum pouches made from polymer film (PA/PE) with barrier properties and storage for 4 months at 18±1°C temperature in dark place. Dried venison samples were analyzed after 0, 35, 91 and 112 days of storage. During the storage total plate counts of dried venison samples significantly (p<0.05) increased. No significant differences in the content of protein, fat and moisture were detected when analyzing dried meat samples during storage and comparing them with the chemical parameters of just dried meat.

Keywords: drying, microwave-vacuum drier, quality, venison

Procedia PDF Downloads 299

Authors: Subodh Kumar, Ramkisan Pawar, Gopal D. Belurkar

Abstract:

This paper describes a study for simple blanking tool. In blanking or piercing operation, punch and die should be concentric for proper cutting. In this study, tolerance analysis method is used to analyze the variation in the press tool assembly. Variation results into the eccentricity in between die and punch due to cumulative tolerance of parts used in assembly. 1D variation analysis were performed by CREO parametric computer aided design (CAD) Software Powered by CETOL 6σ computer aided tolerance analysis software. Use of CAD analysis software given the opportunity to find out the cause of variation in tool assembly. Accordingly, the new specification of tolerance and process setting for die set manufacturing has determined. Tolerance allocation and tolerance analysis method were performed iteratively to conclude that position tolerance as well as size tolerance of hole in top plate for bush and size tolerance of guide pillar were more responsible for eccentricity in punch and die. This work proposes optimum tolerance for press tool assembly parts to achieve 100 % yield for specified .015mm minimum tolerance zone.

Keywords: blanking, GD&T (Geometric Dimension and Tolerancing), DPMU (defects per million unit), press tool, stackup analysis, tolerance allocation, yield percentage

Procedia PDF Downloads 339

Authors: Vikas Baliram Kalyankar

Abstract:

Study of ecology is important as it plays role in development of environment engineering. With the advent of technologies the study of ecosystem structure and changes in it are remaining unnoticed. The ecological succession is the sequential replacement of plant species following changes in the environment. The present study depicts the primary ecological succession in an area leveled up to the height of five feet with no signs of plant life on it. The five quadrates of 1 meter square size were observed during the study period of six months. Rain water being the only source of water in the area increased its ecological importance. The primary successor was non- leguminous plant Balonites roxburgii during the peak drought periods in the region of the summer 2013-14. The increased nitrogen content of soil after the plant implied its role in atmospheric nitrogen fixation.

Keywords: succession, Balonites roxburgii, non-leguminous plant, ecology

Procedia PDF Downloads 479

Authors: Jongho Park, Junwon Lee, Byeonghyun Choi, Kicheol Lee, Dongwook Kim

Abstract:

The typically-used oil sand plant foundations are driven pile or drilled shaft. With more strict environmental regulations world widely, it became more important to completely remove the foundation during the stage of plant demolition. However, it is difficult to remove driven piles or drilled shafts that are installed at a deeper and stronger depth to gain more bearing pile capacity. The helical pile can be easily removed after its use and recycled; therefore it is suitable for oil sand plant foundation. This study analyzes the behavior of helical piles in sands. Axial pile load tests were carried out the varying spacing of helix plates (helices), rotation speed and weight of axial loading during pile installation. From the experiments, optimal helix plate spacing, rotation speed, axial loading during installation were determined. In addition, the behavior of helical pile groups was examined varying pile spacing. Finally, the behavior of single helical piles and that of group helical piles were compared.

Keywords: oil sand plant, pile load test, helical pile, group helical pile, behavior

Procedia PDF Downloads 151

Authors: Nadhir Al-Ansari, Ammar A. Ali, Sven Knutsson

Abstract:

Iraq is located in the Middle East. It covers an area of 433,970 square kilometres populated by about 32 million inhabitants. Iraq greatly relies in its water resources on the Tigris and Euphrates Rivers. Recently, Iraq is suffering from water shortage problems. This is due to external and internal factors. The former includes global warming and water resources policies of neighbouring countries while the latter includes mismanagement of its water resources. The supply and demand are predicted to be 43 and 66.8 Billion Cubic Meters (BCM) respectively in 2015, while in 2025 it will be 17.61 and 77 BCM respectively. In addition, future prediction suggests that Tigris and Euphrates Rivers will be completely dry in 2040. To overcome this problem, prudent water management policies are to be adopted. This includes Strategic Water Management Vision, development of irrigation techniques, reduction of water losses, use of non-conventional water resources and research and development planning.

Keywords: Iraq, Tigris River, Euphrates River, water scarcity, water resources management

Procedia PDF Downloads 435

Authors: A. D. Usman, W. F. Wan Ahmad, H. H. Danjuma

Abstract:

Exposure due to GSM frequencies is subject of daily debate. Though regulatory bodies provide guidelines for exposure, people still exercise fear on the possible health hazard that may result due to long term usage. In this study, exposure due to electromagnetic field emitted by GSM base stations in industrial areas was investigated. The aimed was to determine whether industrial area exposure is higher as compared to residential as well as compliance with ICNIRP guidelines. Influence of reflection and absorption with respect to inverse square law was also investigated. Measurements from GSM base stations were performed at various distances in far field region. The highest measured peak power densities as well as the calculated values at GSM 1.8 GHz were 6.05 and 90 mW/m2 respectively. This corresponds to 0.07 and 1% of ICNIRP guidelines. The highest peak power densities as well as the calculated values at GSM 0.9 GHz were 11.92 and 49.7 mW/m2 respectively. These values were 0.3 and 1.1% of ICNIRP guidelines.

Keywords: Global System for Mobile Communications (GSM), Electromagnetic Field (EMF), far field, power density, Radiofrequency (RF)

Procedia PDF Downloads 460

Authors: Aakanchha Jain, D. V. Kohli

Abstract:

Cubosomes are nanoparticles but instead of the solid particles, cubosomes are self-assembled liquid crystalline particles of certain surfactant with proper ratio of water with a microstructure that provides unique properties of practical interest. Cubosomes encapsulating Fluconazole were prepared by emulsification method and characterized for particle size, entrapment efficiency. The cubosomes prepared were 257.2±2.94 nm in size with drug entrapment efficiency of 66.2±2.69%. The optimized formulation characterized for shape and surface morphology by TEM and SEM analysis. SEM photograph showed the smooth surface of optimized cubosomes and TEM photograph revealed square somewhat circular intact shapes of cubosomes. MIC was determined by XTT based method and antifungal activity was determined in vitro. The cumulative percentage of Fnz from cubosomes permeated via dialysis membrane (MWCO 12-14 KD) showed a percent cumulative drug release of 76.86% while Fnz solution showed release up to 91.04% in 24 hours in PBS (pH 6.5)(p < 0.005).

Keywords: Candids albicans, cubosomes, fluconazole, topical delivery

Procedia PDF Downloads 286

Authors: Ibeku Bernadine Ezenwanyi

Abstract:

Hospital-Acquired Infections (HAI), also called ‘Nosocomial Infection’ is an infection you get while in the hospital for another reason. They are an important cause of morbidity and mortality. This study examined the epidemiology, clinical outcomes of some instruments used on patients especially catheter that was passed on them during their stay in the hospital. It was discovered that they had catheter–associated urinary tract infection (CAUTI). An observational study was carried out from January to March, 2022, on 180 patients (80 males and 100 females) admitted in the surgical wards, medical wards, dialysis unit and intensive care unit (ICU) of the hospital. The patient’s urine samples were collected for urine culture and the isolation was carried out using plate count agar medium and macconkey agar. Among the 80 males, 45 had Urinary Tract Infections (UTI) mostly proteus infection and among the 100 females, 70 also had (UTI) and the most common was caused by Escherichia coli. Other strain of microorganisms such as Klebsiella, Staphylococcus aureus and Pseudomonas aeruginosa. It is important to follow up patients that these devices were used on with antibiotics to make sure that these infections are not developed because the rate of these infections (UTI) are high especially in females.

Keywords: catheter, urinary tract infection, nosocomial infection, microorganisms

Procedia PDF Downloads 100

Authors: Annette Davies

Abstract:

Celebrity entertainment TV news shows such as Access Hollywood, Entertainment Tonight, E! News, etc., have remained extremely popular. While the effects of these shows have been examined in academic literature on various sample populations, the effects have rarely been examined on a sample population of performing artists in the entertainment field. The present research investigates how the consumption of these shows influence the desire for fame and the perception of fame among active performing artists. Two separate chi-square analyses were conducted to yield the following results: 1) as the viewing of these shows increases, the overall desire for fame also tends to increase; 2) performers who believe that these celebrity entertainment TV news shows frame fame positively are more likely to perceive fame as a positive achievement overall. Thus, the results of the second finding are consistent with second-level agenda-setting theory. Limitations and suggestions for future research are also discussed.

Keywords: celebrity, entertainment, fame, performers

Procedia PDF Downloads 104

Authors: Benalia Kouini, Aicha Serier

Abstract:

This work aims to investigate the structure–property relationship in ternary nanocomposites consisting of polypropylene as the matrix, polyamide 66 as the minor phase and treated nanoclay DELLITE 67G as the reinforcement. All PP/PA66/Nanoclay systems with polypropylene grafted maleic anhydride PP-g-MAH as a compatibilizer were prepared via melt compounding and characterized in terms of nanoclay content. Morphological structure was investigated by scanning electron microscopy. The rheological behavior of the nanocomposites was determined by various methods, viz melt flow index (MFI) and parallel plate rheological measurements. The PP/PP-g-MAH/PA66 nanocomposites showed a homogeneous morphology supporting the compatibility improvement between PP, PA66 and nanoclay. SEM results revealed the formation of nanocomposites as the nanoclay was intercalated and exfoliated. In the ternary nanocomposites, the rheological behavior showed that, the complex viscosity is increased with increasing the nanoclay content; however, at low frequencies this increase is governed by the content of nanofiller while at high frequencies it is mainly determined by talc content. A similar trend was also observed for the variations of storage modulus (G′) and loss modulus (G″) with frequency. The results showed that the use of nanoclay considerably affects the melt elasticity.

Keywords: nanocomposites, polypropylene, polyamide66, modified nanoclay, rheology

Procedia PDF Downloads 367

Authors: Sabrina Boutaleb, Fouad Bourad, Kouider Halim Benrahou, Abdelouahed Tounsi

Abstract:

In the present work, the dynamic analysis of the functionally graded rectangular nanoplates is studied. The theory of nonlocal elasticity based on the quasi 3D high shear deformation theory (quasi 3D HSDT) has been employed to determine the natural frequencies of the nanosized FG plate. In HSDT, a cubic function is employed in terms of thickness coordinates to introduce the influence of transverse shear deformation and stretching thickness. The theory of nonlocal elasticity is utilized to examine the impact of the small scale on the natural frequency of the FG rectangular nanoplate. The equations of motion are deduced by implementing Hamilton’s principle. To demonstrate the accuracy of the proposed method, the calculated results in specific cases are compared and examined with available results in the literature, and a good agreement is observed. Finally, the influence of the various parameters, such as the nonlocal coefficient, the material indexes, the aspect ratio, and the thickness-to-length ratio, on the dynamic properties of the FG nanoplates is illustrated and discussed in detail.

Keywords: nonlocal elasticity theory, FG nanoplate, free vibration, refined theory, elastic foundation

Procedia PDF Downloads 102

Authors: Sidra A. Shaikh, M. A. Ahmed, M. W. Akhtar

Abstract:

Global and diffuse solar radiation studies have been carried out for Islamabad (Lat: 330 43’ N, Long: 370 71’) to access the solar potential of the area using sunshine hour data. A detailed analysis of global solar radiation values measured using several methods is presented. These values are then compared with the NASA SSE model. The variation in direct and diffuse components of solar radiation is observed in summer and winter months for Islamabad along with the clearness index KT. The diffuse solar radiation is found maximum in the month of July. Direct and beam radiation is found to be high in the month of April to June. From the results it appears that with the exception of monsoon months, July and August, solar radiation for electricity generation can be utilized very efficiently throughout the year. Finally, the mean bias error (MBE), root mean square error (RMSE) and mean percent error (MPE) for global solar radiation are also presented.

Keywords: solar potential, global and diffuse solar radiation, Islamabad, errors

Procedia PDF Downloads 422

Authors: Ch. Ramreddy, P. Naveen, D. Srinivasacharya

Abstract:

The objective of the present study is to investigate the effect of nonlinear temperature and concentration on the mixed convective flow of micropolar fluid over an inclined flat plate in a non-Darcy porous medium in the presence of convective boundary condition. In order to analyze all the essential features, the transformed nonlinear conservation equations are worked out numerically by spectral method. By insisting the comparison between vertical, horizontal and inclined plates, the physical quantities of the flow and its characteristics are exhibited graphically and quantitatively with various parameters. An increase in the coupling number and inclination of angle tend to decrease the skin friction, mass transfer rate and the reverse change is there in wall couple stress and heat transfer rate. The nominal effect on the wall couple stress and skin friction is encountered whereas the significant effect on the local heat and mass transfer rates are found for high enough values of Biot number.

Keywords: convective boundary condition, micropolar fluid, non-darcy porous medium, non-linear convection, spectral method

Procedia PDF Downloads 259

Authors: Jimena Alarcon, Andrea Llorens, Gabriel Hernandez, Maritza Palma, Lucia Navarrete

Abstract:

The research has funding from the Government of Chile and is focused on defining the design of rural primary classroom that stimulates creativity. The relevance of the study consists of its capacity to define adequate educational spaces for the implementation of the design-based learning (DBL) methodology. This methodology promotes creativity and teamwork, generating a meaningful learning experience for students, based on the appreciation of their environment and the generation of projects that contribute positively to their communities; also, is an inquiry-based form of learning that is based on the integration of design thinking and the design process into the classroom. The main goal of the study is to define the design characteristics of rural primary school classrooms, associated with the implementation of the DBL methodology. Along with the change in learning strategies, it is necessary to change the educational spaces in which they develop. The hypothesis indicates that a change in the space and equipment of the classrooms based on the emotions of the students will motivate better learning results based on the implementation of a new methodology. In this case, the pedagogical dynamics require an important interaction between the participants, as well as an environment favorable to creativity. Methodologies from Kansei engineering are used to know the emotional variables associated with their definition. The study is done to 50 students between 6 and 10 years old (average age of seven years), 48% of men and 52% women. Virtual three-dimensional scale models and semantic differential tables are used. To define the semantic differential, self-applied surveys were carried out. Each survey consists of eight separate questions in two groups: question A to find desirable emotions; question B related to emotions. Both questions have a maximum of three alternatives to answer. Data were tabulated with IBM SPSS Statistics version 19. Terms referred to emotions are grouped into twenty concepts with a higher presence in surveys. To select the values obtained as part of the implementation of Semantic Differential, a number expected of 'chi-square test (x2)' frequency calculated for classroom space is considered lower limit. All terms over the N expected a cut point, are included to prepare tables for surveys to find a relation between emotion and space. Statistic contrast (Chi-Square) represents significance level ≥ 0, indicator that frequencies appeared are not random. Then, the most representative terms depend on the variable under study: a) definition of textures and color of vertical surfaces is associated with emotions such as tranquility, attention, concentration, creativity; and, b) distribution of the equipment of the rooms, with emotions associated with happiness, distraction, creativity, freedom. The main findings are linked to the generation of classrooms according to diverse DBL team dynamics. Kansei engineering is the appropriate methodology to know the emotions that students want to feel in the classroom space.

Keywords: creativity, design-based learning, education spaces, emotions

Procedia PDF Downloads 134

Authors: I. A. Simsek, S. N. Dogan, A. S. Kipcak, E. Morodor Derun, N. Tugrul

Abstract:

In this study, the drying characteristics of shrimp are studied by using the traditional drying method of oven. Drying temperatures are selected between 60-80°C. Obtained experimental drying results are applied to eleven mathematical models of Alibas, Aghbashlo et al., Henderson and Pabis, Jena and Das, Lewis, Logaritmic, Midilli and Kucuk, Page, Parabolic, Wang and Singh and Weibull. The best model was selected as parabolic based on the highest coefficient of determination (R²) (0.999990 at 80°C) and the lowest χ² (0.000002 at 80°C), and the lowest root mean square error (RMSE) (0.000976 at 80°C) values are compared to other models. The effective moisture diffusivity (Deff) values were calculated using the Fick’s second law’s cylindrical coordinate approximation and are found between 6.61×10⁻⁸ and 6.66×10⁻⁷ m²/s. The activation energy (Ea) was calculated using modified form of Arrhenius equation and is found as 18.315 kW/kg.

Keywords: activation energy, drying, effective moisture diffusivity, modelling, oven, shrimp

Procedia PDF Downloads 172

Authors: Farizy Yunaz, Catur Sasongko

Abstract:

This research aims to provide the empirical evidence regarding cost stickiness behavior and its determinants on listed manufacturing companies. Hypothesis testing is performed using pooled least square method. The result concludes that there is cost stickiness behavior in selling, general and administrative costs. In term of determinants, firm-specific adjustment costs measured by asset intensity and employee intensity have significant positive impact on the level of cost stickiness. Meanwhile, earnings target and leverage have significant negative impact on the level of cost stickiness. However, the management empire building incentives measured by free cash flow has no significant positive impact.

Keywords: adjustment cost, cost behavior, cost stickiness, earnings target, leverage, management empire building incentive

Procedia PDF Downloads 345

Authors: Sevda Engin, Ugur Buyuk, Necmettin Marasli

Abstract:

Directional solidification of eutectic alloys attracts considerable attention because of microhardness, tensile strength, and electrical resistivity influenced by eutectic structures. In this research, we examined processing of Al–Si–Fe (Al–11.7wt.%Si–1wt.%Fe) eutectic by directional solidification. The alloy was prepared by vacuum furnace and directionally solidified in Bridgman-type equipment. During the directional solidification process, the growth rates utilized varied from 8.25 m/s to 164.80 m/s. The Al–Si–Fe system showed an eutectic transformation, which resulted in the matrix Al, Si and Al5SiFe plate phases. The eutectic spacing between (λ_Si-λ_Si, λ_(Al_5 SiFe)-λ_(Al_5 SiFe)) was measured. Additionally, the microhardness, tensile strength, and electrical resistivity of the alloy were determined using directionally solidified samples. The effects of growth rates on microhardness, tensile strength, and electrical resistivity for directionally solidified Al–Si–Fe eutectic alloy were investigated, and the relationships between them were experimentally obtained. It was found that the microhardness, tensile strength, and electrical resistivity were affected by both eutectic spacing and the solidification parameter.

Keywords: directional solidification, aluminum alloy, microstructure, electrical properties, tensile test, hardness test

Procedia PDF Downloads 284

Authors: M. A. Ahmed, Sidra A. Shaikh, M. W. Akhtar

Abstract:

Solar radiation on horizontal surface over three southern cities of Sindh, namely Karachi, Hyderabad and Nawabshah has been investigated to asses the feasibility of solar energy application for power generation. In the present work, measured data of bright sunshine hour of the region have been used to estimate the global and diffuse solar radiation. The regression coefficient 'a' and 'b' have been calculated using first order Angstrom type co-relation. The result obtained shows that the contribution of direct solar radiation is low and diffuse radiation is high during the monsoon months July and August for Karachi and Hyderabad. The sky remains clear from September to June, whereas for Nawabshah the global radiation remains high throughout the year. The potential of grid quality solar photovoltaic power in Karachi is estimated for 10 square meter area of solar panel.

Keywords: solar potential over Sindh, global and diffuse solar radiation, radiation over three cities of Sindh, solar panels

Procedia PDF Downloads 425