Penerapan ciri-ciri guru berkesan dalam proses pengajaran dan pembelajaran semasa latihan mengajar dalam kalangan Pelajar Sarjana UTHM

Kajian ini bertujuan untuk mengenal pasti sejauh mana penerapan ciri-ciri guru berkesan di kalangan pelajar sarjana Fakulti Pendidikan Teknikal dan Vokasional (FPTV) dari Universiti Tun Hussein Onn Malaysia (UTHM) dalam pengajaran dan pembelajaran dalam kelas semasa menjalani latihan mengajar serta faktor yang paling dominan. Keduanya, kajian ini adalah untuk melihat tahap persepsi pelajar terhadap ciri-ciri guru berkesan pada guru pelatih dan menentukan sama ada terdapat perbezaan dalam memberi persepsi berdasarkan perbezaan jantina. Kajian ini adalah berbentuk kuantitatif. Kajian ini dijalankan di politeknik premier di Malaysia. Data instrumen yang hendak dikaji diperolehi daripada edaran borang soal selidik. Responden adalah terdiri daripada 182 orang pelajar politeknik dimana terdapat pelajar sarjana FPTV yang sedang menjalani latihan mengajar. Seramai lapan orang pensyarah pelatih telah dipilih secara rawak untuk menjadi sampel penilaian oleh responden. Data yang diperolehi akan di analisis dengan menggunakan pendekatan Rasch dan perisian winsteps 3.69.1.11. Nilai pekali Alpha Cronbach untuk kajian ini adalah 0.98. Dapatan kajian mendapati faktor kebolehan pensyarah kaya ilmu pengetahuan merupakan faktor yang paling dominan dengan nilai min logit -0.13. Dapatan kajian menunjukkan tahap persepi pelajar terhadap ciri-ciri guru berkesan dalam kalangan pensyarah pelatih adalah tinggi. Dari segi memberi persepsi terhadap penyarah pelatih berdasarkan ciri-ciri guru berkesan didapati tidak terdapat perbezaan dalam memberi persepsi walaupun berbeza jantina. Pensyarah pelatih dari UTHM telah menerapkan ciri-ciri guru berkesan dalam pengajaran dan pembelajaran semasa latihan mengajar kerana berdasarkan dapatan kajian secara keseluruhannya responden menunjukkan tahap persetujuan yang tinggi (skor min 4.25). Ini menunjukkan bahawa pensyarah pelatih telah mengaplikasikan kemahiran dan pengetahuan dari segi pedagogi, psikologi semasa menjalani latihan mengajar

Pressure-dependent transition from atoms to nanoparticles in magnetron sputtering: Effect on WSi2 film roughness and stress

We report on the transition between two regimes from several-atom clusters to much larger nanoparticles in Ar magnetron sputter deposition of WSi2, and the effect of nanoparticles on the properties of amorphous thin films and multilayers. Sputter deposition of thin films is monitored by in situ x-ray scattering, including x-ray reflectivity and grazing incidence small angle x-ray scattering. The results show an abrupt transition at an Ar background pressure Pc; the transition is associated with the threshold for energetic particle thermalization, which is known to scale as the product of the Ar pressure and the working distance between the magnetron source and the substrate surface. Below Pc smooth films are produced, while above Pc roughness increases abruptly, consistent with a model in which particles aggregate in the deposition flux before reaching the growth surface. The results from WSi2 films are correlated with in situ measurement of stress in WSi2/Si multilayers, which exhibits a corresponding transition from compressive to tensile stress at Pc. The tensile stress is attributed to coalescence of nanoparticles and the elimination of nano-voids.Comment: 16 pages, 10 figures; v3: published versio

Advanced coatings through pulsed magnetron sputtering

Pulsed magnetron sputtering (PMS) has become established as the process of choice for the deposition of dielectric materials for many applications. The process is attractive because it offers stable arc free operating conditions during the deposition of, for example, functional films on architectural and automotive glass, or antireflective/antistatic coatings on displays. Recent studies have shown that pulsing the magnetron discharge also leads to hotter and more energetic plasmas in comparison with continuous dc discharges, with increased ion energy fluxes delivered to the substrate. As such, the PMS process offers benefits in the deposition of a wide range of materials. The present paper describes three examples where PMS has led to either significant enhancement in film properties or enhanced process flexibility: in low friction titanium nitride coatings, in Al doped zinc oxide transparent conductive oxide coatings sputtered directly from powder targets and in thin film photovoltaic devices based on copper (indium/gallium) diselenide. These examples demonstrate the versatility of PMS and open up new opportunities for the production of advanced coatings using this technique

Generation of tunable q-switched erbium-doped fiber laser based on graphite flakes saturable absorber

Pulsed fiber laser has tremendous application in laser processing and laser sensor. The key element to produce a passively Q-switched fiber laser is by using a saturable absorber (SA). Passively Q-switched fiber laser is the most desirable pulse in laser technology due to its ability to generate optical pulses in microsecond and nanosecond. The aim of this study is to construct a single ring erbium-doped fiber (EDF) laser based on graphite flakes SA to produce short pulse laser. Graphite flakes SA were prepared by mechanical exfoliation techniques and was transferred onto a fiber ferrule tip. The saturable absorption property of the graphite was measured using twin detector method which resulted in a modulation depth of 23.82% with a saturation intensity of 0.031 MW/cm2. Surface morphology, elemental analysis and absorbance characteristics of the graphite flakes were analyzed by the field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX) and ultraviolet visible spectroscopy (UV-VIS). The result showed that the carbon element on the SA has a very strong peak intensity. The two different EDF coefficient of 6.43 dB/m and 18.93 dB/m (EDF M-5 and EDF I-12) showed a repetition rate of 41.62 kHz and 60.00 kHz with a pulse width of 6.45 μs and 3.38 μs, respectively at a pump power of 268.8 mW. The wavelength tunability of passively Q-switched fiber laser for EDF M-5 and EDF I-12 were optimized at fixed pump power where the tuning range of EDF M-5 occurred between 1544 nm to 1560 nm and 1552 nm to 1570 nm for EDF I-12. The passively Q-switched fiber laser with different EDF coefficients were successfully constructed in a single ring configuration with more selection of wavelength that is up to L band by using higher EDF coefficient

Time resolved measurement of film growth during reactive high power pulsed magnetron sputtering (HIPIMS) of titanium nitride

The growth rate during reactive high power pulsed magnetron sputtering (HIPIMS) of titanium nitride is measured with a temporal resolution of up to 25 us using a rotating shutter concept. According to that concept a 200 um slit is rotated in front of the substrate synchronous with the HIPIMS pulses. Thereby, the growth flux is laterally distributed over the substrate. By measuring the resulting deposition profile with profilometry and with x-ray photoelectron spectroscopy, the temporal variation of the titanium and nitrogen growth flux per pulse is deduced. The analysis reveals that film growth occurs mainly during a HIPIMS pulse, with the growth rate following the HIPIMS phases ignition, current rise, gas rarefaction, plateau and afterglow. The growth fluxes of titanium and nitrogen follow slightly different behaviors with titanium dominating at the beginning of the HIPIMS pulse and nitrogen at the end of the pulse. This is explained by the gas rarefaction effect resulting in a dense initial metal plasma and metal films which are subsequently being nitrified

Magnetic field strength influence on the reactive magnetron sputter deposition of Ta2O5

Reactive magnetron sputtering enables the deposition of various thin films to be used for protective as well as optical and electronic applications. However, progressing target erosion during sputtering results in increased magnetic field strengths at the target surface. Consequently, the glow discharge, the target poisoning, and hence the morphology, crystal structure and stoichiometry of the prepared thin films are influenced. Therefore, these effects were investigated by varying the cathode current Im between 0.50 and 1.00 A, the magnetic field strength B between 45 and 90 mT, and the O2/(Ar+O2) flow rate ratio between 0 and 100%. With increasing oxygen flow ratio a sub-stoichiometric TaOx oxide forms at the metallic Ta target surface which further transfers to a non-conductive tantalum pentoxide Ta2O5, impeding a stable DC glow discharge. These two transition zones (from Ta to TaOx and from TaOx to Ta2O5) shift to higher oxygen flow rates for increasing target currents. Contrary, increasing the magnetic field strength (e.g., due to sputter erosion) mainly shifts the TaOx to Ta2O5 transition to lower oxygen flow rates while marginally influencing the Ta to TaOx transition. To allow for a stable DC glow discharge (and to suppress the formation of non-conductive Ta2O5 at the target) even at a flow rate ratio of 100% either a high target current (Im >= 1 A) or a low magnetic field strength (B <= 60 mT) is necessary. These conditions are required to prepare stoichiometric and fully crystalline Ta2O5 films. Our investigations clearly demonstrate the importance of the magnetic field strength, which changes during sputter erosion, on the target poisoning and the resulting film quality.Comment: 10 pages, 9 figures, 1 tabl

Nano-structured morphological features of pulsed direct current magnetron sputtered Mo films for photovoltaic applications

Historically, molybdenum thin films have been used as the back contact for Cu(In,Ga)Se2 based solar cells and as such the properties of these layers play an important role in the overall cell structure. This paper describes the production of molybdenum films using pulsed d.c magnetron sputtering from compressed molybdenum powder targets. The films were deposited at different substrate temperatures under constant power and constant current modes, and analysed using X-ray diffraction, scanning electron microscopy, atomic force microscopy and four point resistance probe. Mechanical strain and resistivity were found to decrease with substrate temperature together with a shift in the (110) crystallographic plane towards higher diffraction angles. All films were well adhered to the glass substrates irrespective of their high tensile strain. Surface morphology analysis revealed the presence of nano-structured stress relief patterns which can enhance the nucleation sites for subsequent CuInSe2 deposition. A high-resolution cross sectional image showed the columnar growth of the films. Surface roughness analysis revealed that roughness increased with increase in substrate temperature