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

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

CONSTRUCTING AND VALIDATING MODULE OF “SOCIAL LIFE SKILL” FOR PRESCHOOL EDUCATORS

Social Life Skill is a very important ability for human life in society. The current situation in Indonesia shows the skill is not developed properly so that conflict happened everywhere and physical as well as mental destruction happened at the end. Therefore the social life skill is very important to be educated since early childhood. This second-year-research is intended: (1) to construct module of “social life skill” for preschool educators based on the finding of the first year research in connection with preschool educator knowledge on social life skill and how to implement it in educating children; (2) to evaluate the validity of the module, either its content or readability; and (3) to make the module perfect/better based on the result of try out. The study used research and development approach with the design model of Borg and Gall. Operational variable used is the concept of social life skill, consists of three aspects: (1) Empathy, (2) Affiliation and conflict resolution, and (3) Developing positive manners. Each has 3 sub aspects. Therefore there are 3 modules constructed and each has 3 sub modules. The research subjects are kindergarten teachers which institution where they work located in village area, and in the city. Their level of education consist of: junior secondary, senior secondary, 1, 2, 3 years diploma and S1 from various study programs, some are not related with early childhood education. They are also ranged from 1 to 30 years working experience. The content of the modules was validated by experts in early childhood education and Indonesian language judgment. There are 9 sub modules being evaluated its content and readability so that it will be easy to be read by preschool teachers. Readability test using cloze method which means the text of the module taken the 7th word and made it blank which should be filled by reader for readability testing. The sub modules were checked its readability two times, first with 6 preschool teachers. The second was involving 68 – 72 preschool teachers for each sub module. The criteria of readability are: if more than 60% readers could answer the right words, the text of the sub module is considered to be easy to understand ; if 41% – 60% readers could answer the right word, the text of the sub module is considered to be medium and needs instructor to help understanding the text ; whereas if only 40% or less readers could answer the right words, the text is considered difficult to understand and should be revised. The norm used to accept the module is the criteria of more than 60% readers could answer the right words. The finding of the first try out ranged from 44.54% to 77.02%, and the second was ranged from 61.54% to 83.70%. The result of the research are: (1) There are 3 modules of “social life skill” constructed, each has 3 sub modules, so there are totally 9 sub modules constructed; (2) The content validity of the modules were evaluated by expert judgement, and the readability testing of sub modules (using Cloze method) was all reach level of readability: easy to understand; and (3) In order to make the modules easier to understand, the words considered difficult were revised or presented in glossary. Keywords: module, social life skill, preschool educator FIP, 2007 (PPB

A COMPLEX SURFACE FORMATION MODEL ON CHITOSAN ADSORPTION TO METALS

The aim of the first year research is: to predict a complex surface formation between chitosan and metal ions. This prediction is according to the plot adsorptive capacity and the bonding tendency between chitosan and some metals. Chitosan as adsorbent isolated from Green Crab’s shell. Metal ions used in this research are Cr(III), Cu(II), Ni(II), Zn(II), Fe(II) and Pb(II). The subject of this research is green crab’s shell (Scylla serata) and the object is the adsorptive capacity chitosan to some metal ions. Chitosan was prepared in three steps: deproteination, demineralization and deacetylation. This chitosan are impurities by 20 %- 30%kitin. The adsorption experiment was carried out at room temperature for 24 hours. A half gram of chitosan was added into 50 mL of various metals solution at pH system 5. This experiment was performed in two methods. An each ion metal was adsorbed by chitosan and some metal ions i.e: Cr(III), Cu(II), and Ni(II) (1:1:1) were adsorbed simultaneous. Chitosan was characterized by FTIR. Metal ions concentration before and after adsorption was measured by by AAS. Adsorptive capacity is defined as differences of metal ion concentration due to the adsorption per gram chitosan. Then the obtained data was plotted through Langmuir isotherm and Freundlich isotherm equations. The result of this work concludes that adsorptive capacity of chitosan in order for some metals ion are Cr(III) > Fe(II)> pb(II) = Zn(II)> Ni(II) = Cu(II). The interaction chitosan with metal ions is indicated complex surface formation by -NH2 groups or –OH groups. A multilayer are formatted by active site chitosan and metal ion interactions, but the interaction of chitosan to copper(II) is prefer a monolayer formation. Key words: chitosan, adsorption, multilay FMIPA, 2006 (PEND. KIMIA

Hot spin spots in the laser-induced demagnetization

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]

PENGARUH LATIHAN SATRIA NUSANTARA TINGKAT PRADASAR-DASAR TERHADAP PENURUNAN HORMON STRESS (KORTISOL)

This research study is aimed at revealing the influence of stressors in Satria Nusantara pre-elementary breathing exercise training towards the reduction of the level of stress hormone (Kartisol). This is an experimental research, using Randomized pretest-posttest control group design. The number of samples used in the treatment group and control group is 15 people respectively. Elisa method was used as the technique of laboratory examination. Data analysis was done through t-test, using SPSS program for Windows. Based on the results of t test analysis on Kartisol variables, there were significant differences between treatment group and control group with p = 0.002 (p <0.05). In this Kartisol variables, there was also reduction in treatment groups of 4.77 ng/ml and 0.83 ng/ml in the control group. The difference was due to breathing exercise treatment using breath control and dhikr so that psychologically treatment group will be more calm, relaxed compared to the control group. Thus breathing exercise can be one of the cheap, effective alternative exercise to reduce stress hormone levels (Kartisol). With relatively low levels of Kartisol, it will provide an opportunity for lymphocytes T to produce interleukin 2 (Th1) and interleukin 4 (Th2). Interleukin will stimulate plasma cells to produce immunoglobulin. By the increase of the activity of plasma cells, IgG also indirectly increases. Thereby, the reduction of Kartisol has a positive influence on the increase of immunoglobulin G. Based on the findings, the Satria Nusantara breathing exercise can be used as a model of alternative sports in order to improve body endurance. Key words: Influence, breathing exercise, reduction, Kartisol

A route to room temperature ferromagnetic ultrathin SrRuO3_3 films

Experimental efforts to stabilize ferromagnetism in ultrathin films of transition metal oxides have so far failed, despite expectations based on density functional theory (DFT) and DFT+U. Here, we investigate one of the most promising materials, SrRuO$_3$, and include correlation effects beyond DFT by means of dynamical mean field theory. In agreement with experiment we find an intrinsic thickness limitation for metallic ferromagnetism in SrRuO$_3$ thin films. Indeed, we demonstrate that the realization of ultrathin ferromagnetic films is out of reach of standard thin-film techniques. Proposing charge carrier doping as a new route to manipulate thin films, we predict room temperature ferromagnetism in electron-doped SrRuO$_3$ ultra thin films.Comment: 5 pages, 3 figure

Glide reflection symmetry, Brillouin zone folding and superconducting pairing for the P4/nmmP4/nmm space group

Motivated by the studies of the superconducting pairing states in the iron-based superconductors, we analyze the effects of Brillouin zone folding procedure from a space group symmetry perspective for a general class of materials with the $P4/nmm$ space group. The Brillouin zone folding amounts to working with an effective one-Fe unit cell, instead of the crystallographic two-Fe unit cell. We show that the folding procedure can be justified by the validity of a glide reflection symmetry throughout the crystallographic Brillouin zone and by the existence of a minimal double degeneracy along the edges of the latter. We also demonstrate how the folding procedure fails when a local spin-orbit coupling is included although the latter does not break any of the space group symmetries of the bare Hamiltonian. In light of these general symmetry considerations, we further discuss the implications of the glide reflection symmetry for the superconducting pairing in an effective multi-orbital $t-J_{1}-J_{2}$ model. We find that the $P4/nmm$ space group symmetry allows only pairing states with even parity under the glide reflection and zero total momentum

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

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

Generating high-order optical and spin harmonics from ferromagnetic monolayers

High-order harmonic generation (HHG) in solids has entered a new phase of intensive research, with envisioned band-structure mapping on an ultrashort time scale. This partly benefits from a flurry of new HHG materials discovered, but so far has missed an important group. HHG in magnetic materials should have profound impact on future magnetic storage technology advances. Here we introduce and demonstrate HHG in ferromagnetic monolayers. We find that HHG carries spin information and sensitively depends on the relativistic spin-orbit coupling; and if they are dispersed into the crystal momentum ${\bf k}$ space, harmonics originating from real transitions can be ${\bf k}$-resolved and carry the band structure information. Geometrically, the HHG signal is sensitive to spatial orientations of monolayers. Different from the optical counterpart, the spin HHG, though probably weak, only appears at even orders, a consequence of SU(2) symmetry. Our findings open an unexplored frontier -- magneto-high-order harmonic generation.Comment: 19 pages, 4 figure