Horizontal cellular oscillations caused by time-periodic resonant thermal forcing in weakly nonlinear Darcy-Bénard convection

The onset of Rayleigh-Bénard convection in a horizontally unbounded saturated porous medium is considered. Particular attention is given to the stability of weakly nonlinear convection between two plane horizontal surfaces heated from below. The primary aim is to study the effects on postcritical convection of having small amplitude time-periodic resonant thermal forcing. Amplitude equations are derived using a weakly nonlinear theory and they are solved in order to understand how the flow evolves with changes in the Darcy-Rayleigh number and the forcing frequency. When convection is stationary in space, it is found to consist of one of two different types depending on its location in parameter space: either a convection pattern where each cell rotates in the same way for all time with a periodic variation in amplitude (Type I) or a pattern where each cell changes direction twice within each forcing period (Type II). Asymptotic analyses are also performed (i) to understand the transition between convection of types I and II; (ii) for large oscillation frequencies and (iii) for small oscillation frequencies. In a large part of parameter space the preferred pattern of convection when the layer is unbounded horizontally is then shown to be one where the cells oscillate horizontally—this is a novel form of pattern selection for Darcy-Bénard convection

Radiation pattern reconfigurable fm antenna

In this work, a radiation pattern reconfigurable antenna design using compact printed spiral monopoles that operates at 102 MHz is reported. The proposed antenna changes its radiation behaviour that responds towards a desired direction with the use of RF switches. The antenna is printed on a 76.6mm × 50mm PCB layer providing more than 20MHz bandwidth at -10 dB threshold and is easily fabricated with low manufacturing cost. The antenna was also simulated on 500mm × 500mm ground plane that represents the roof top of a vehicl

MODEL PENGEMBANGAN WISATA BAHARI DI KAWASAN TANJUNG WAIROLE DAN PULAU TIGA KABUPATEN MALUKU TENGAH

“Zamrud khatulistiwa”, sebutan yang sangat dikenal bagi wisatawan yang berkunjung ke Indonesia. Sebagai negara bahari dan negara kepulauan terbesar di dunia, Indonesia memiliki sumberdaya hayati pesisir dan pulaupulau kecil yang sangat potensial untuk dikembangkan. Untuk itu dituntut suatu perencanaan dan pengelolaan sumberdaya pesisir yang berkelanjutan agar bermanfaat dalam mendukung pembangunan ekonomi daerah dan nasional, antara lain berupa peningkatan penerimaan devisa negara, peningkatan lapangan kerja. Pengelolaan sumberdaya dapat dilakukan melalui pengembangan pariwisata. Sayangnya hal ini dapat menimbulkan tekanan terhadap ekosistem pesisir dan pulau-pulau kecil, karena kesadaran tentang pelestarian lingkungan yang masih minim. Keuntungan lebih banyak diperoleh bukan oleh penduduk setempat tetapi oleh pihak swasta. Dengan berjalannya waktu dan melihat kondisi lingkungan wisata pesisir yang semakin memprihatinkan, maka timbul kesadaran masyarakat dan pemerhati lingkungan untuk melakukan pengelolaan khusus berbasis konservasi demi menjaga kelestarian lingkungan pesisir dan meminimalisir dampak negatif yang timbul seperti kerusakan ekosistem dan kepunahan jenis-jenis biota pesisir, disamping menjaga dan menyelamatkan adat dan budaya masyarakat setempa

Measurement Model Value Aspects of Teacher Leadership in Vocational Education

Teaching profession at present is very challenging and the teachers themselves must be prepared to deal with it. The issue of teachers and the teaching profession continue to gain attention and often widely debated whether in the media, among the general public and even discussed until the national level. Negative sentiment against teachers often receives media attention although not authentic, and it creates a feeling of prejudice and less happy society on the individual teacher. These issues need to be addressed wisely by all teachers and the parties involved so that the dignity of the profession remain respected. Teachers need to show good values of the students, school and community. This is important because there is value in teachers will influence others to stay in school or otherwise. People often look at the behavior of teachers and assess externally only. Teachers must have admirable traits that can guide and educate students to become excellent once formed their personal character. This study aimed to verify the instrument model aspects of the leadership of teachers in technical and vocational education. Specifically, the objectives of this study were to confirm the scale of the measurement model teacher leadership and to identify the reliability of the instrument model. This study used a questionnaire to collect data from respondents. The questionnaire used is divided into two parts, Part A and Part B Section A consisted of demographic data, while Part B contains 53 item questionnaire measuring aspects of the leadership of the teachers in improving teaching and student learning, teacher leadership skills in improve relations and cooperation with the community and other parties, leadership skills and attributes of teachers in skill lead. And practice leadership skills teacher professional learning for continuous improvement. The study population consisted of all students of semester 8, IPG Zone east coast of peninsular Malaysia. This study used a sample of all the population to study. However, only 153 questionnaires that can be used for analysis and the respondents for this survey. This questionnaire has been validated by a panel of experts consisting of a lecturer who specializes in the study in IPGK Zone east coast of Malaysia, to get the validity of the content. The questionnaire was constructed and tested for suitability in the context of teacher education in IPGK Zone east coast of Malaysia

Prediction of Soil Anisotropic Stress-Strain Behaviour Incorporating Shear Strength Using Improvise Normalised Stress-Strain Method

Currently the soil anisotropic stress-strain behaviour can be predicted accurately at any effective stress using the Rotational Multiple Yield Surface Framework. This framework incorporates the developed of mobilised shear strength within the body of the soil mass whenever the soil is subjected to anisotropic compression. However the accuracy of the framework can be improvised since the failure axial strain is not unique but increases as the effective stress increases. This improved method s call normalised strain method. This method is applied to predict the stress-strain behaviour of granitic residual soil grade V from Kuala Kubu Baharu. The improve accuracy of this method will be presented in comparison with the conventional method

Horizontal cellular oscillations caused by time-periodic resonant thermal forcing in weakly nonlinear Darcy-Bénard convection

The onset of Rayleigh-Bénard convection in a horizontally unbounded saturated porous medium is considered. Particular attention is given to the stability of weakly nonlinear convection between two plane horizontal surfaces heated from below. The primary aim is to study the effects on postcritical convection of having small amplitude time-periodic resonant thermal forcing. Amplitude equations are derived using a weakly nonlinear theory and they are solved in order to understand how the flow evolves with changes in the Darcy-Rayleigh number and the forcing frequency. When convection is stationary in space, it is found to consist of one of two different types depending on its location in parameter space: either a convection pattern where each cell rotates in the same way for all time with a periodic variation in amplitude (Type I) or a pattern where each cell changes direction twice within each forcing period (Type II). Asymptotic analyses are also performed (i) to understand the transition between convection of types I and II; (ii) for large oscillation frequencies and (iii) for small oscillation frequencies. In a large part of parameter space the preferred pattern of convection when the layer is unbounded horizontally is then shown to be one where the cells oscillate horizontally—this is a novel form of pattern selection for Darcy-Bénard convection

Antidepressant-like effect of aqueous extract of Channa striatus fillet in mice models of depression.

Background and Objectives: Channa (C.) striatus (Malay-Haruan), is a fresh water snakehead fish, consumed as a rejuvenating diet in post-parturition period in local Malay population. The aqueous extract of C. striatus fillet (AECSF) was reported to act through serotonergic receptor system in a previous study. There is no scientific report on neuropharmacological effects of C. striatus. Based on these data, the antidepressant-like effect of C. striatus was evaluated in mice models of depression. Materials and Methods: AECSF was prepared by steaming the fillets as described previously. Antidepressant activity was studied in male ICR mice using forced swimming test (FST) and tail suspension test (TST). Open-field test was used to evaluate any psychomotor stimulant activity. AECSF was administered intraperitoneally at the concentrations of 30%, 40% and 50% w/v at the dosage of 10 ml/kg. Amitriptyline (10 mg/kg) was used as positive control. Results: All the three concentrations of AECSF (30%, 40% and 50% w/v) significantly reduced the immobility time (p < 0.001) in FST and TST. All the three concentrations of AECSF (30%, 40% and 50% w/v) significantly (p < 0.001) reduced locomotor activity in a dose-dependent manner in open-field test. Conclusions: AECSF produced significant reduction of immobility time in both FST and TST. Amitriptyline produced a significant reduction of immobility time in both FST and TST similar to previous findings. The AECSF produced a dose-dependent decrease in locomotor activity in the open-field test. This hypolocomotion effect indicated the absence of any psychomotor stimulant activity thereby supporting the antidepressant-like effect of the AECSF. The pharmacological mechanisms of the observed antidepressant-like effect and hypolocomotion effect are not understood from our study. Hence, further studies are required

Analysis of Surrogate Safety Performance Parameters for an Interurban Corridor

956-965Traditionally, road safety performance evaluation is an analysis of crash data from the past. However, methods of analysis from crash data have some well-known limitations from an analytical point of view. These limitations include small data samples causing statistical issues in analysis, under reporting of crashes and very little information about behavioral and environmental aspects at crash time. The micro simulation combined with traffic conflict technique enables the transportation engineers to investigate the safety performance of a corridor without using the crash data. Surrogate Safety Assessment Model (SSAM), utilizes simulated vehicle trajectories from the micro simulation software to investigate conflict severity and locations. In this study, safety performance evaluation is carried out of an interurban corridor of 24.3 km stretch from Gurugram to Faridabad in state of Haryana (India) using simulation software VISSIM (Verkehr In Städten – SIMulationsmodell) and SSAM. Simulated vehicular trajectories were generated and analyzed using SSAM to identify potential conflicts. The surrogate safety measures Time to Collision (TTC), Post Encroachment Time (PET) and Max ΔV are obtained by an analysis from SSAM model for all the three homogeneous sections such as midblock, curve section and intersections separately. The approach presented in the paper helps in the identification of inter-urban corridor locations prone to road crashes and hence serves as a proactive alternative as opposed to historical crashes based analyses