Pengembangan Perangkat Pembelajaran Berbasis Model Learning Cycle-7e pada Materi Trigonometri untuk Meningkatkan Kemampuan Koneksi Matematis Siswa

The aim of this research is producing learning instrument based on the model of learning cycle 7E in trigonometry which are valid, practical and effective. This research refers to the developmental model of Plomp which consists of three phases that are pleminary research, prototyping phase, and assessment phase. The quality of learning instrument based on the test of validity, practicality and effectiveness. Based on data analysis, the results are: the score validity of lesson plan and the students worksheet are 3,54 and 3,44 respectively, the score practicality of lesson plan and the students worksheet are 3,53 and 3,21 respectively, the students' ability of mathematical connections on aspects of the connection between concepts or procedures in the same material increase from 66 to 81 with high category, the students' ability of mathematical connections on aspects of the connection between concepts or procedures in matter different mathematics increase from 49,5 to 77,9 with the high category, and the student's ability of mathematical connections in aspects of the connection between concepts or procedures in the context of daily life increase from 55,8 to 77,4 with the high category. The students' ability of mathematical connections in classical increased from 57,1 to 78,8 with the high category. Thus, the instrument learning based on the models of learning cycle7E in trigonometry subject for high school students of grade 10 otherwise valid, practical and effective. Tujuan penelitian ini adalah menghasilkan perangkat pembelajaran materi trigonometri berbasis model learning cycle 7E yang valid, praktis dan efektif. Model pengembangan mengacu pada model Plomp yang terdiri atas tiga tahap yaitu, pleminary research, prototyping phase dan assessment phase. Kualitas perangkat pembelajaran didasarkan pada uji kevalidan, kepraktisan dan kefektifan. Berdasarkan analisis data, diperoleh hasil yaitu: (1) skor kevalidan RPP adalah 3,54, skor kevalidan LKS adalah 3,44, skor kevalidan instrumen penelitian adalah 3,66, (2) skor kepraktisan RPP 3,53 dan skor kepraktisan LKS 3,21, (3) kemampuan koneksi matematis siswa pada aspek koneksi antar konsep atau prosedur dalam materi yang sama mengalami peningkatan dari 66 menjadi 81 dengan kategori tinggi, kemampuan koneksi matematis siswa pada aspek koneksi antar konsep atau prosedur dalam materi matematika yang berbeda mengalami peningkatan dari 49,5 menjadi 77,9 dengan kategori tinggi, dan kemampuan koneksi matematis siswa pada aspek koneksi antar konsep atau prosedur dalam konteks kehidupan sehari mengalami peningkatan dari 55,8 menjadi 77,4 dengan kategori tinggi. Kemampuan koneksi matematis siswa secara klasikal meningkat dari 57,1 nilai 78,8 dengan kategori tinggi. Dengan demikian, perangkat pembelajaran berbasis model learning cycle 7E pada materi trigonometri untuk siswa SMA kelas X dinyatakan valid, praktis dan efektif

Effect of selected factors on non-uniformity of triticale seeds dosage with pin sowing unit

Badano wpływ szerokości międzyrzędzi, prędkości siewu oraz szerokości szczeliny wysiewającej na nierównomierność dozowania kołeczkowym zespołem wysiewającym nasion pszenżyta ozimego odmiany "Woltario" w ilości 130 kgźha-1. Analiza korelacji czynników wykazała, że przy założonym poziomie istotności [alfa] = 0,05 istotny wpływ na nierównomierność dozowania nasion ma szerokość międzyrzędzi oraz prędkość siewu. W wyniku analizy regresji wielu zmiennych z krokową procedurą eliminacji zmiennych nieistotnych otrzymano równanie stopnia drugiego, które zawiera dodatkowo trzecią zmienną - szerokość szczeliny wysiewającej.The effect of interrows width, speed of sowing and width of sowing slit on non-uniformity of Woltario cv. winter triticale seeds dosed with pin sowing unit at 130 kg per ha was tested. Analysis of correlation coefficients performed at [alpha]=0.05 showed that significant effect on non-uniformity of seeds dosage was stated for width of interrows and speed of sowing. After regression analysis with step-wise procedure of non-significant factors elimination square equation with additional third variable - width of sowing slit was received

Phonon vibrational frequencies and elastic properties of solid SrFCl. An ab initio study

The phonon vibrational frequencies, electronic and elastic properties of SrFCl, one of the members of the alkaline-earth fluorohalide family crystallizing with the PbFCl-type structure, have been investigated, for the first time, at the ab initio level, by using the periodic CRYSTAL program. Both Hartree-Fock (HF) and density functional theory (DFT) Hamiltonians have been used, with the latter in its local density, gradient-corrected (PW91), and hybrid (B3LYP) versions. The structural and elastic properties are in good agreement with experiment, with the exception of those calculated within the local density approximation, which were found to be systematically under-estimated (distances) or over-estimated (elastic properties). As regards the phonon frequencies, B3LYP and PW91 provide excellent results, the mean absolute difference with respect to the experimental Raman data being 4.1% and 3.6%, respectively. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2005

Micro-Raman spectroscopy for the detection of stacking fault density in InAs and GaAs nanowires

We investigate the relation between crystal stacking faults in individual wurtzite InAs and GaAs nanowires and the intensity of the forbidden longitudinal optical (LO) phonon mode in the Raman spectra. Micro-Raman spectroscopy and transmission electron microscopy are combined on the same individual nanowires to evaluate the LO mode intensity as a function of the stacking fault density. A clear increase in the LO mode intensity was observed when the stacking fault density was increased. Our results confirm the utility of Raman spectroscopy as a powerful tool for detecting crystal defects in nanowires