Cryogenic Stress-Driven Grain Growth Observed via Microcompression with in situ Electron Backscatter Diffraction

The deformation of materials at cryogenic temperature is of interest for space, arctic, and fundamental science applications. In this work, a custom-built cooling system attached to a commercial picoindenter was used for in situ cryogenic microcompression testing of equal-channel angular-pressed copper with real-time electron backscatter diffraction. Stress-driven grain growth at cryogenic temperatures was observed during a series of elastic and plastic deformations. These results provide direct evidence for the previously predicted phenomenon, whereas previous ex situ examinations demonstrated coarsening after cryogenic loading when samples were not maintained at cryogenic temperatures between deformation and characterization

Noncommutative Solitons in Open N=2 String Theory

Coincident D2-branes in open N=2 fermionic string theory with a B-field background yield an integrable modified U(n) sigma model on noncommutative R^{2,1}. This model provides a showcase for an established method (the `dressing approach') to generate solutions for integrable field equations, even in the noncommutative case. We demonstrate the technique by constructing moving U(1) and U(2) solitons and by computing their energies. It is outlined how to derive multi-soliton configurations with arbitrary relative motion; they correspond to D0-branes moving inside the D2-branes.Comment: 1+13 pages, LaTeX; v2: eq.(45) corrected, constructing of multi-solitons enhanced, one reference added; v3: minor corrections but soliton/antisoliton convention interchanged, final JHEP versio

Modeling pedestrian evacuation movement in a swaying ship

With the advance in living standard, cruise travel has been rapidly expanding around the world in recent years. The transportation of passengers in water has also made a rapid development. It is expected that ships will be more and more widely used. Unfortunately, ship disasters occurred in these years caused serious losses. It raised the concern on effectiveness of passenger evacuation on ships. The present study thus focuses on pedestrian evacuation features on ships. On ships, passenger movements are affected by the periodical water motion and thus are quite different from the characteristic when walking on static horizontal floor. Taking into consideration of this special feature, an agent-based pedestrian model is formulized and the effect of ship swaying on pedestrian evacuation efficiency is investigated. Results indicated that the proposed model can be used to quantify the special evacuation process on ships.Comment: Traffic and Granular Flow'15, At Delft, the Netherland

Efficent Approach Use to Increase accuracy Multimodal Biometric System for Feature Level Fusion

Security system comprised of a single form of biometric information cannot fulfil user’s expectations and may suffer from noisy sensor data, intra and inter class variations and continuous spoof attacks. To overcome some of these problems, multimodal biometric aims at increasing the reliability of biometric systems through utilizing more than one biometric in decision-making process.In this paper we propose a Efficient and Robust Multimodal Biometric System for feature level fusion that combines the information to investigate whether the integration of fingerprints and signatures . Proposed system extracts Gabor texture from the preprocessed fingerprints and signatures sample. The feature vectors attained from different methods are in different sizes and the features from equivalent image may be correlated. Therefore, we proposed wavelet-based fusion techniques. Finally apply neural network’s Cascaded feed forward Back propagation Algorithm to Train Neurons for recognition.proposed approach is authenticated for their accuracy on Fingerprints virtual database fused with signature virtual database of 16 users. The experimental results demonstrated that the proposed multimodal biometric system achieves a recognition accuracy of 99.8% and with false rejection rate (FRR) of = 1

Zone Segmentation and Thinning based Algorithm for Segmentation of Devnagari Text

Character segmentation of handwritten documents is an challenging research topic due to its diverse application environment.OCR can be used for automated processing and handling of forms, old corrupted reports, bank cheques, postal codes and structures. Now Segmentation of a word into characters is one of the major challenge in optical character recognition. This is even more challenging when we segment characters in an offline handwritten document and the next hurdle is presence of broken ,touching and overlapped characters in devnagari script. So, in this paper we have introduced an algorithm that will segment both broken as well as touching characters in devnagari script. Now to segment these characters the algorithm uses both zone segmentation and thinning based techniques. We have used 85 words each for isolated, broken, touching and both broken as well as touching characters individually. Results achieved while segmentation of broken as well as touching are 96.2 % on an average

Tunable Hydrogen Storage in Magnesium - Transition Metal Compounds

Magnesium dihydride (\mgh) stores 7.7 weight % hydrogen, but it suffers from a high thermodynamic stability and slow (de)hydrogenation kinetics. Alloying Mg with lightweight transition metals (TM = Sc, Ti, V, Cr) aims at improving the thermodynamic and kinetic properties. We study the structure and stability of Mg$_x$TM$_{1-x}$H$_2$ compounds, $x=[0$-1], by first-principles calculations at the level of density functional theory. We find that the experimentally observed sharp decrease in hydrogenation rates for $x\gtrsim0.8$ correlates with a phase transition of Mg$_x$TM$_{1-x}$H$_2$ from a fluorite to a rutile phase. The stability of these compounds decreases along the series Sc, Ti, V, Cr. Varying the transition metal (TM) and the composition $x$, the formation enthalpy of Mg$_x$TM$_{1-x}$H$_2$ can be tuned over the substantial range 0-2 eV/f.u. Assuming however that the alloy Mg$_x$TM$_{1-x}$ does not decompose upon dehydrogenation, the enthalpy associated with reversible hydrogenation of compounds with a high magnesium content ($x=0.75$) is close to that of pure Mg.Comment: 8 pages, 5 figure

Keluarga sebagai Titik Awal Perkembangan Sosial Anak Usia Dini ( sebuah Kajian Sosiologis )

Setiap orang tua menaruh harapan agar putra-putrinya berhasil dalam perkembangan sosialnya, yakni mampu menjadi sosok manusia sosial yang dapat diterima oleh lingkungan sosialnya dan menjadi anggota masyarakat yang bermanfaat bagi kehidupan sesamanya. Orang tua akan merasa gagal manakala putra-putrinya berkembang sebagai manusia yang a-sosial (tidak lumrah/wajar secara sosial ) apalagi sampai menjadi manusia anti - sosial (membuat resah bahkan membahayakan bagi kehidupan masyarakatnya ). Anak usia dini berada pada masa usia paling peka dan adaptif terhadap berbagai stimulus yang datang dari lingkungannya, juga berada pada masa-masa kritis bagi pertumbuhan dan perkembangannya yang akan mempengaruhi tahap perkembangan selanjutnya. Disadari bahwa upaya optimalisasi perkembangan anak usia dini membutuhkan dukungan lingkungan yang kondusif untuk pengasuhan dan pengembangannya. The Consultative Group on Early Chidlhood Care and Development mendefinisikan “Pengasuhan dan Pengembangan Anak Usia Dini “ sebagai suatu kegiatan yang ditujukan bagi orang tua dan anggota keluarga lainnya untuk membina tumbuh kembang anak usia 0-8 tahun secara menyeluruh dengan memberikan rangsangan bagi pengembangan mental, intelektual, emosional, moral dan sosial yang tepat dan benar, agar anak dapat tumbuh dan berkembang secara optimal. Usaha yang dapat dilakukan mencakup pemeliharaan aspek kesehatan, pemberian nutrisi, stimulasi intelektual, penyediaan kesempatan yang luas untuk mengeksplorasi dan belajar secara aktif, pengembangan sosial dan emosional, pengasuhan dan bimbingan anak untuk memahami potensi diri yang dimilikinya serta berperan aktif dalam keluarga dan masyarakat. Oleh sebab itu keluarga diharapkan mampu menjadi lingkungan pendidik pertama dan utama dalam proses pengasuhan dan pengembangan anak usia dini, serta menjadi wahana awal bagi perkembangan sosialnya melalui pengembangan “social skills – socialization” yang berlangsung dalam kehidupan keluarga. Tujuan utama pengembangan sosial pada anak usia dini adalah agar anak dapat mengembangkan pola-pola interaksi sosial secara sukses, terjadi keselarasan antara nilai-nilai social control dan internal control, sehingga mampu berkembang sebagai manusia sosial. Berhasil tidaknya perkembangan sosial anak usia dini akan ditentukan oleh kualitas proses sosialisasinya dalam keluarga, yang menjadi awal penentu keberhasilan perkembangan sosialnya

Death happy: Adaptive ageing and its evolution by kin selection in organisms with colonial ecology

Standard evolutionary theory, supported by mathematical modelling of outbred, dispersed populations predicts that ageing is not an adaptation. We recently argued that in clonal, viscous populations, programmed organismal death could promote fitness through social benefits and has, in some organisms (e.g. Caenorhabditis elegans), evolved to shorten lifespan. Here we review previous adaptive death theory, including consumer sacrifice, biomass sacrifice, and defensive sacrifice types of altruistic adaptive death. In addition we discuss possible adaptive death in semelparous fish, coevolution of reproductive and adaptive death, and adaptive reproductive senescence in C. elegans. We also describe findings from recent tests for the existence of adaptive death in C. elegans using computer modelling. Such models have provided new insights into how trade-offs between fitness at the individual and colony levels mean that senescent changes can be selected traits. Exploring further the relationship between adaptive death and social interactions, we consider examples where adaptive death results more from action of kin than from self-destructive mechanisms and, to describe this, introduce the term adaptive killing of kin. This article is part of the special issue on ‘Ageing and sociality’

Feynman Rules in the Type III Natural Flavour-Conserving Two-Higgs Doublet Model

We consider a two Higgs-doublet model with $S_3$ symmetry, which implies a $\pi \over 2$ rather than 0 relative phase between the vacuum expectation values $$and$$. The corresponding Feynman rules are derived accordingly and the transformation of the Higgs fields from the weak to the mass eigenstates includes not only an angle rotation but also a phase transformation. In this model, both doublets couple to the same type of fermions and the flavour-changing neutral currents are naturally suppressed. We also demonstrate that the Type III natural flavour-conserving model is valid at tree-level even when an explicit $S_3$ symmetry breaking perturbation is introduced to get a reasonable CKM matrix. In the special case $\beta = \alpha$, as the ratio $\tan\beta = {v_2 \over v_1}$ runs from 0 to $\infty$, the dominant Yukawa coupling will change from the first two generations to the third generation. In the Feynman rules, we also find that the charged Higgs currents are explicitly left-right asymmetric. The ratios between the left- and right-handed currents for the quarks in the same generations are estimated.Comment: 16 pages (figures not included), NCKU-HEP/93-1