29,517 research outputs found

    Laser-induced spin protection and switching in a specially designed magnetic dot: A theoretical investigation

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    Most laser-induced femtosecond magnetism investigations are done in magnetic thin films. Nanostructured magnetic dots, with their reduced dimensionality, present new opportunities for spin manipulation. Here we predict that if a magnetic dot has a dipole-forbidden transition between the lowest occupied molecular orbital (LUMO) and the highest unoccupied molecular orbital (HOMO), but a dipole-allowed transition between LUMO+1 and HOMO, electromagnetically inducedtransparency can be used to prevent ultrafast laser-induced spin momentum reduction, or spin protection. This is realized through a strong dump pulse to funnel the population into LUMO+1. If the time delay between the pump and dump pulses is longer than 60 fs, a population inversion starts and spin switching is achieved. Thesepredictions are detectable experimentally.Comment: 6 pages, three figur

    Hot spin spots in the laser-induced demagnetization

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    Laser-induced femtosecond magnetism or femtomagnetism simultaneously relies on two distinctive contributions: (a) the optical dipole interaction (ODI) between a laser field and a magnetic system and (b) the spin expectation value change (SEC) between two transition states. Surprisingly, up to now, no study has taken both contributions into account simultaneously. Here we do so by introducing a new concept of the optical spin generator, a product of SEC and ODI between transition states. In ferromagnetic nickel, our first-principles calculation demonstrates that the larger the value of optical spin generator is, the larger the dynamic spin moment change is. This simple generator directly links the time-dependent spin moment change {\Delta}Mk z (t) at every crystal- momentum k point to its intrinsic electronic structure and magnetic properties. Those hot spin spots are a direct manifestation of the optical spin generator, and should be the focus of future research.Comment: 10 pages, 2 figures, [email protected]

    Inventarisasi Lichen (Lumut Kerak) Di Kecamatan Banjarsari Di Kota Surakarta Provinsi Jawa Tengah

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    The lichen spesies found in Banjarsari sub-district in SurakartaCity Central Java Province have not been identified. The purpose of this to know the type of lichen that exist along the road n District Banjarsari in Surakarta City Central Java Province. Data collection method used s survey method conducted in two research stasions. Data of research result analysed by qualitative exploration are presented in table and picture. The results of the study were 5 spesies, among others Dirinaria picta, Parmelia sulcata, Flavoparmelia sp., Dirinaria applamata, and Lepraria incana, and included in 3 families that is Family Stereocaulaceae, Family Parmeliaceae and Family Caliciaceae. The observation made on both stations show that the percentage of lichen on the bark tree substrate show different values. Each lichen species in each station has a percentage value below 50%. Monitoring amountof vechicles passing trhough Banjarsari Sub-district in Surakarta City Central Java Provinve is densely packed as it show the number of ┬▒ 96,576 vehicles every day. Keywords : Banjarsari District, Inventory, Vehicle Monitoring

    Efektivitas Kombinasi Ekstrak Daun Salam Dan Daun Mint Sebagai Obat Kumur Alami

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    Moutwash is a solution used to rinse the mouth to avoid bacteria. One of the materials used to make natural mounthwash is the bay leaf and mint leaf. Bay leaves contain essential oils, flavonoids and tannins that can act as an antibacterial, while the mint leaves contain menthol which can give a fresh taste in the mouth. The purpose of the study is to determine the effectiveness of leaves extractsthe addition of mint leaves as a natural mouthwash and to know the organoleptic quality of the natural mouthwash of the bay leaves and the addition of mint leaves. The research design used Completely Randomized Design (CDR) of one factor that kind of mouthwash (S), S1: distilled water, S2: 60% of bay leafconcentration extract and 50% mint leaf concentration extract, S3: 70% of bay leafconcentration extract and 60% mint leaf concentration extract. Bacteria data population were analized using the Man-Whitney Test. The result showed that S1, S2 and S3 donÔÇÖt show significant result. Most of mouthwash products arebrown, the distinctive aroma of little mint bay leaves, a little taste of sepet, rather clear and acceptance in dominant society is S2 because it is little teste of sepet. The conclusion of this study is S2 and S3 treatment iseffectiveless in inhibiting the growth ofin spittle bacteria

    PERTUMBUHAN JAMUR PADA MEDIA BIJI KLUWIH DAN BIJI NANGKA SEBAGAI SUBSTITUSI MEDIA PDA

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    THE GROWTH OF FUNGUS IN KLUWIH AND NANGKA SEEDS MEDIA AS A SUBSTITUTION PDA MEDIA. Resti Rahmawati, A420120048, Department of Biology Education, School of Teacher Training and Education, Muhammadiyah University of Surakarta, March, XVI+32 ABSTRACT PDA is the most media to grow the fungus, but the price of this media is expensive so it need an alternative media that easy and cheap to get it. This study aims to determine the growth of Aspergillus niger in alternative kluwih and nangka seeds media. This research was an experimental study using a completely randomized design (CRD) one factor was the type of media is PDA (M0), kluwih seed media (M1), nangka seed media (M2) and using the test fungus A. niger (J1). Inoculation of A. niger used agar block method for 3 days with a temperature of 28Ôü░C. Parameter of research was colony diameter and sporulation of A. niger. Data were analyzed with descriptive qualitative methods. The result of this research showed that the best growth for Aspergillus niger was after 72 hours incubation, colony diameter continually in PDA media, kluwih seed media, nangka seed media is 4,7 cm, 4,3 cm, 4,1 cm with heavy sporulation. So, the conclution is that kluwih and nangka seeds media can be use as a substitution of PDA media for the growth of fungus. Keyword : kluwih and nangka seeds, Aspergillus niger, PDA

    Kemampuan Technological Pedagogical and Content Knowledge (TPACK) Guru IPA di Sekolah Inklusi SMP Negeri 23 Surakarta Tahun Ajaran 2017 - 2018

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    Development of information and communication technology demand that teacherÔÇÖs doesnt only know how to teach the student and know material subtance, but also the teacherÔÇÖs must know the technology that makes student easier in understanding. TPACK (Technological Pedagogical And Content Knowledge) is the ability of teacher how to give student teaching facilities from certain material through pedagogical approach and technology. This ability of TPACK is very important for teacherÔÇÖs, specially to teacher who taught children in need of special in the inclusive school. This research aims to know the ability of TPACK (Technological Pedagogical And Content Knowledge) the IPA teacherÔÇÖs in inclusive school junior high school 23 of surakarta academic year 2017/2018. The typw of this reseacrh is deskriptive qualitative with the sampling technique is purposive sampling to take sample of taecher and take three lesson plan from each teacher. Based on the research thatÔÇÖs been done, the ability of the IPA teacherÔÇÖs in inclusive school junior high school 23 is included in the category of 4,7% less well

    Aktivitas Antioksidan Teh Kombinasi Daun Anting-Anting Dan Daun Kelor Dengan Variasi Suhu Pengeringan

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    Tea combination leaf earring and Moringa leaf is one beverage that has health giving properties that can be potentially as a basic ingredient of making tea. The content of the chemical compound leaf earrings are saponins, tannins, flavonoids and essential oils, while the chemical compound content of Moringa leaves are saponins, tannins, flavonoids, alkaloids, steroids, triterpenoids, and essential oil. The purpose of this study to determine the content and the antioxidant activity of a combination of organoleptic quality tea leaf earrings and moringa leaves to the drying temperature variations. The method used in this study is completely randomized design (CRD) with two factors. Factor 1: Variations combination of leaf earrings : moringa leaves 1: 1 (P1), 2: 1 (P2), 1: 2 (P3) and a factor of 2: Variations in temperature of 45 ┬░C (S1), 50 ┬░C (S2 ), 55 ┬░C (S3). The results showed that the highest antioxidant activity of tea at treatment P1S3 namely 81.4%, and the lowest antioxidant activity of tea at treatment P3S1 ie 13.8%. Combination of organoleptic quality tea leaf earrings and Moringa leaves have a light brown color, bitter taste, aroma rather unpleasant, and acceptance do not like
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