Multiwavelength fiber laser based on bidirectional lyot filter in conjunction with intensity dependent loss mechanism

We experimentally demonstrate a multiwavelength fiber laser (MWFL) based on bidirectional Lyot filter. A semiconductor optical amplifier (SOA) is used as the gain medium, while its combination with polarization controllers (PCs) and polarization beam combiner (PBC) induces intensity dependent loss (IDL) mechanism. The IDL mechanism acts as an intensity equalizer to flatten the multiwavelength spectrum, which can be obtained at a certain polarization state. Using different ratio of optical splitter has affected to multiwavelength flatness degradation. Subsequently, when we removed a polarizer in the setup, the extinction ratio (ER) is decreased. Ultimately, with two segments of polarization maintaining fiber (PMF), two channel spacings can be achieved due to splicing shift of 0° and 90°

The Mediation Effect of Trusting Beliefs on the Relationship Between Expectation-Confirmation and Satisfaction with the Usage of Online Product Recommendation

Online Product Recommendations (OPRs) are increasingly available to onlinecustomers as a value-added self-service in evaluating and choosing a product.Research has highlighted several advantages that customers can gain from usingOPRs. However, the realization of these advantages depends on whether and towhat extent customers embrace and fully utilise them. The relatively low OPR USAgerate indicates that customers have not yet developed trust in OPRs’ performance.Past studies also have established that satisfaction is a valid measure of systemperformance and a consistent significant determinant of users’ continuous systemusage. Therefore, this study aimed to examine the mediation effect of trustingbeliefs on the relationship between expectation-confirmation and satisfaction. Theproposed research model is tested using data collected via an online survey from626 existing users of OPRs. The empirical results revealed that social-psychologicalbeliefs (perceived confirmation and trust) are significant contributors to customersatisfaction with OPRs. Additionally, trusting beliefs partially mediate the impactof perceived confirmation on customer satisfaction. Moreover, this study validatesthe extensions of the interpersonal trust construct to trust in OPRs and examinesthe nomological validity of trust in terms of competence, benevolence, andintegrity. The findings provide a number of theoretical and practical implications.&nbsp

Quasiperpendicular high Mach number Shocks

Shock waves exist throughout the universe and are fundamental to understanding the nature of collisionless plasmas. Reformation is a process, driven by microphysics, which typically occurs at high Mach number supercritical shocks. While ongoing studies have investigated this process extensively both theoretically and via simulations, their observations remain few and far between. In this letter we present a study of very high Mach number shocks in a parameter space that has been poorly explored and we identify reformation using in situ magnetic field observations from the Cassini spacecraft at 10 AU. This has given us an insight into quasi-perpendicular shocks across two orders of magnitude in Alfven Mach number (MA) which could potentially bridge the gap between modest terrestrial shocks and more exotic astrophysical shocks. For the first time, we show evidence for cyclic reformation controlled by specular ion reflection occurring at the predicted timescale of ~0.3 {\tau}c, where {\tau}c is the ion gyroperiod. In addition, we experimentally reveal the relationship between reformation and MA and focus on the magnetic structure of such shocks to further show that for the same MA, a reforming shock exhibits stronger magnetic field amplification than a shock that is not reforming.Comment: Accepted and Published in Physical Review Letters (2015

Suprathermal electrons at Saturn's bow shock

The leading explanation for the origin of galactic cosmic rays is particle acceleration at the shocks surrounding young supernova remnants (SNRs), although crucial aspects of the acceleration process are unclear. The similar collisionless plasma shocks frequently encountered by spacecraft in the solar wind are generally far weaker (lower Mach number) than these SNR shocks. However, the Cassini spacecraft has shown that the shock standing in the solar wind sunward of Saturn (Saturn's bow shock) can occasionally reach this high-Mach number astrophysical regime. In this regime Cassini has provided the first in situ evidence for electron acceleration under quasi-parallel upstream magnetic conditions. Here we present the full picture of suprathermal electrons at Saturn's bow shock revealed by Cassini. The downstream thermal electron distribution is resolved in all data taken by the low-energy electron detector (CAPS-ELS, <28 keV) during shock crossings, but the higher energy channels were at (or close to) background. The high-energy electron detector (MIMI-LEMMS, >18 keV) measured a suprathermal electron signature at 31 of 508 crossings, where typically only the lowest energy channels (<100 keV) were above background. We show that these results are consistent with theory in which the "injection" of thermal electrons into an acceleration process involves interaction with whistler waves at the shock front, and becomes possible for all upstream magnetic field orientations at high Mach numbers like those of the strong shocks around young SNRs. A future dedicated study will analyze the rare crossings with evidence for relativistic electrons (up to ~1 MeV).Comment: 22 pages, 5 figures. Accepted for publication in Ap

Priming Benih Padi (Oryza Sativa L.) dengan Zn untuk Meningkatkan Vigor Bibit pada Cekaman Terendam

Seed priming has been widely used to improve seedling vigor of several crops such as corn, wheat, and rice. Seed priming with zinc to increase seedling tolerance on submergence stress had never been evaluated. The objective of this research was to identify agronomical and physiological characteristics of several rice genotypes during seedling stage at submergence stress following zinc priming treatment. This research used factorial randomized block design with three replications. The first factor was rice genotypes and second factor was zinc solution of ZnSO4.7H2O. Seeds were soaked with Zn solution at different concentrations namely 0, 2.5, dan 5.0 mM respectively for 24 hours. After that the seeds were germinated on soil media in side the plastic box. Fourteen days-old seedling were submerged in water for 5 days and then return to normal condition for recovery. Parameters being observed included seedling dry weight, shoot carbohydrate, and leaves chlorophyl which were measured after 10 days of recovery. Seedling height was measured once a week from 2nd to 4th week. Results showed that intolerant genotypes to submergence stress grew faster but seedling dry weight, shoot carbohydrate and leaves chlorophyll content were lower compared to those tolerant genotypes. Local and national varieties which were not tolerant to submergence stress could be improved by priming treatment with 5.0mM zinc

The Plant Propagation Algorithm: Modifications and Implementation

The Plant Propagation Algorithm, epitomised by the Strawberry Algorithm, has been previously successfully tested on low dimensional continuous optimisation problems. It is a neighborhood search algorithm. In this paper, we introduce a robust and efficient version of the algorithm and explain how it can be implemented to compete with one of the best available alternatives, namely the Artificial Bee Colony algorithm and we present an improved and more effective variant on standard continuous optimisation test problem instances in high dimensions. Computational and comparative results are included

Regionalization and harmonization in TVET

A transversal skill is one of the skills needed in every type of workplace setting. There is limited information about the perceptions of which transferable skills are needed in the workplace. The objective of this study is to explore the transferable skills among students and lecturers in TVET higher learning institutions in Indonesia and Malaysia. In the present study, transferable skills consist of communication skills, collaboration skills, problem-solving skills, entrepreneurship, and learning to learn skills. A qualitative research was conducted using survey. The five Likert scale questionnaire was distributed to lecturers and students from selected Malaysian and Indonesian universities who have bachelor program in engineering. Based on the analysis outcomes, it is clearly shown that Malaysian university engineering students yielded significantly higher scores on the perceptions of transferable skill acquisition in all measured components compared to their counterparts in Indonesia. Similar patterns of data distribution have been observed in Malaysian and Indonesian engineering students. Based on the lecturers’ perception, Malaysian and Indonesian Engineering Lecturers have comparable perceptions in the aspects of problem solving skills and entrepreneurship skills. In contrast, Malaysian university engineering lecturers gained significantly higher scores on the perception of communication skill, collaboration skill, and learning to learn skill compared to the Indonesian lecturers. The results indicate the need to increase transferable skills of both lecturers and students

A Ka-Band Horn Antenna Excited With Parasitic Dielectric Resonator Antenna

A pyramidal horn antenna excited with parasitic dielectric resonator (DR) antenna for use at Ka-band frequencies is proposed