22,032 research outputs found

    A re-evaluation of finite-element models and stress-intensity factors for surface cracks emanating from stress concentrations

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    A re-evaluation of the 3-D finite-element models and methods used to analyze surface crack at stress concentrations is presented. Previous finite-element models used by Raju and Newman for surface and corner cracks at holes were shown to have ill-shaped elements at the intersection of the hole and crack boundaries. These ill-shaped elements tended to make the model too stiff and, hence, gave lower stress-intensity factors near the hole-crack intersection than models without these elements. Improved models, without these ill-shaped elements, were developed for a surface crack at a circular hole and at a semi-circular edge notch. Stress-intensity factors were calculated by both the nodal-force and virtual-crack-closure methods. Both methods and different models gave essentially the same results. Comparisons made between the previously developed stress-intensity factor equations and the results from the improved models agreed well except for configurations with large notch-radii-to-plate-thickness ratios. Stress-intensity factors for a semi-elliptical surface crack located at the center of a semi-circular edge notch in a plate subjected to remote tensile loadings were calculated using the improved models. The ratio of crack depth to crack length ranged form 0.4 to 2; the ratio of crack depth to plate thickness ranged from 0.2 to 0.8; and the ratio of notch radius to the plate thickness ranged from 1 to 3. The models had about 15,000 degrees-of-freedom. Stress-intensity factors were calculated by using the nodal-force method

    Gas Kinematics and Excitation in the Filamentary IRDC G035.39-00.33

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    Some theories of dense molecular cloud formation involve dynamical environments driven by converging atomic flows or collisions between preexisting molecular clouds. The determination of the dynamics and physical conditions of the gas in clouds at the early stages of their evolution is essential to establish the dynamical imprints of such collisions, and to infer the processes involved in their formation. We present multi-transition 13CO and C18O maps toward the IRDC G035.39-00.33, believed to be at the earliest stages of evolution. The 13CO and C18O gas is distributed in three filaments (Filaments 1, 2 and 3), where the most massive cores are preferentially found at the intersecting regions between them. The filaments have a similar kinematic structure with smooth velocity gradients of ~0.4-0.8 km s-1 pc-1. Several scenarios are proposed to explain these gradients, including cloud rotation, gas accretion along the filaments, global gravitational collapse, and unresolved sub-filament structures. These results are complemented by HCO+, HNC, H13CO+ and HN13C single-pointing data to search for gas infall signatures. The 13CO and C18O gas motions are supersonic across G035.39-00.33, with the emission showing broader linewidths toward the edges of the IRDC. This could be due to energy dissipation at the densest regions in the cloud. The average H2 densities are ~5000-7000 cm-3, with Filaments 2 and 3 being denser and more massive than Filament 1. The C18O data unveils three regions with high CO depletion factors (f_D~5-12), similar to those found in massive starless cores.Comment: 20 pages, 14 figures, 6 tables, accepted for publication in MNRA

    Rancang Bangun Aplikasi Pengendalian Inventori Menggunakan Metode Economic Order Quantity (EOQ) pada Klinik H2LC Surabaya

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    H2LC clinic is a clinic Aesthetic & Anti Aging berkonsisten apply the concept of healthy living by combining elements of beauty and health of the skin and body. Clinic H2LC presenting beauty products from the best herbal ingredients and are safe to use in the long term. H2LC clinic is located at Jl Raya Ngagel Jaya Utara No. 71, Surabaya. Business processes H2LC include Care Clinic, Consultation, and Beauty Products. At this time the business process at Beauty Clinic H2LC not computerized, so that the customer data collection process, data collection product, supplier data collection, sales transactions, purchases and sales summary along with any purchase requires a long time. Because the sales department must seek customer data one by one on the shelves available, sales should check the remaining products are available manually and record sales transactions manually memorandum cause difficulties in clinical H2LC merekap sales reports. Section pharmacist experienced difficulties in checking the stock of products available or empty and had trouble buying a recapitulation report. H2LC clinics often mangalami emptiness products that cause customer clinics H2LC not satisfied due to existing products are often empty and requires a long time to order these products. Therefore, in this final project made an inventory control application using methods Ecomomic Order .Quantity (EOQ) in Surabaya H2LC Clinic. Applications Inventory Control Method Using EOQ can set the number of product inventory, in order to produce the amount of products supplied is not too much or not too little (empty

    Experimental signatures of the quantum-classical transition in a nanomechanical oscillator modeled as a damped driven double-well problem

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    We demonstrate robust and reliable signatures for the transition from quantum to classical behavior in the position probability distribution of a damped double-well system using the Qunatum State Diffusion approach to open quantum systems. We argue that these signatures are within experimental reach, for example in a doubly-clamped nanomechanical beam.Comment: Proceedings of the conference FMQT 1

    Critical behavior of simplicial chiral models

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    The large-N saddle-point equations for the principal chiral models defined on a d-1 dimensional simplex are derived from the external field problem for unitary integrals. The saddle point equation are studied analytically and numerically in many relevant instances, including d=4 and d\rightarrow\infty, with special attention to the critical domain, which is found to correspond to \beta_c=1/d for all d. Related models (chiral chains) are discussed and large-N solutions are analyzed

    Biochemical markers in bronchial carcinoma.

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    A total of 107 patients with bronchial carcinoma have been studied for the presence of potential circulating tumour markers which might be used as indicators of recurrence after primary treatment. Plasma carcinoembryonic antigen (CEA) levels were estimated in every patient and, after a preliminary hormone screening study, plasma calcitonin (CT) and parathyroid hormone (PTH) levels were assayed in 66 patients. Oat-cell tumours proved to be of particular interest in that CEA levels greater than 40 microgram/l were measured (initially or subsequently) in 40.6 percent and CT levels were elevated in 75 percent. Longitudinal studies point towards the possible use of elevated marker levels as guides to therapy when all other features of recurrent disease are lacking. It is clear that no ideal tumour marker exists for bronchial carcinoma but in an individual case an abnormal level of one or more marker substances may provide a valuable aid to treatment

    Cosmic Rays and Large Extra Dimensions

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    We have proposed that the cosmic ray spectrum "knee", the steepening of the cosmic ray spectrum at energy E \gsim 10^{15.5} eV, is due to "new physics", namely new interactions at TeV cm energies which produce particles undetected by the experimental apparatus. In this letter we examine specifically the possibility that this interaction is low scale gravity. We consider that the graviton propagates, besides the usual four dimensions, into an additional δ\delta, compactified, large dimensions and we estimate the graviton production in ppp p collisions in the high energy approximation where graviton emission is factorized. We find that the cross section for graviton production rises as fast as (s/Mf)2+δ(\sqrt{s}/M_f)^{2+\delta}, where MfM_f is the fundamental scale of gravity in 4+δ4+\delta dimensions, and that the distribution of radiating a fraction yy of the initial particle's energy into gravitational energy (which goes undetected) behaves as δyδ1\delta y^{\delta -1}. The missing energy leads to an underestimate of the true energy and generates a break in the {\sl inferred} cosmic ray spectrum (the "kne"). By fitting the cosmic ray spectrum data we deduce that the favorite values for the parameters of the theory are Mf8M_f \sim 8 TeV and δ=4\delta =4.Comment: 8 pages, 1 figur

    The actin-myosin regulatory MRCK kinases: regulation, biological functions and associations with human cancer

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    The contractile actin-myosin cytoskeleton provides much of the force required for numerous cellular activities such as motility, adhesion, cytokinesis and changes in morphology. Key elements that respond to various signal pathways are the myosin II regulatory light chains (MLC), which participate in actin-myosin contraction by modulating the ATPase activity and consequent contractile force generation mediated by myosin heavy chain heads. Considerable effort has focussed on the role of MLC kinases, and yet the contributions of the myotonic dystrophy-related Cdc42-binding kinases (MRCK) proteins in MLC phosphorylation and cytoskeleton regulation have not been well characterized. In contrast to the closely related ROCK1 and ROCK2 kinases that are regulated by the RhoA and RhoC GTPases, there is relatively little information about the CDC42-regulated MRCKα, MRCKβ and MRCKγ members of the AGC (PKA, PKG and PKC) kinase family. As well as differences in upstream activation pathways, MRCK and ROCK kinases apparently differ in the way that they spatially regulate MLC phosphorylation, which ultimately affects their influence on the organization and dynamics of the actin-myosin cytoskeleton. In this review, we will summarize the MRCK protein structures, expression patterns, small molecule inhibitors, biological functions and associations with human diseases such as cancer

    3D Face Reconstruction from Light Field Images: A Model-free Approach

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    Reconstructing 3D facial geometry from a single RGB image has recently instigated wide research interest. However, it is still an ill-posed problem and most methods rely on prior models hence undermining the accuracy of the recovered 3D faces. In this paper, we exploit the Epipolar Plane Images (EPI) obtained from light field cameras and learn CNN models that recover horizontal and vertical 3D facial curves from the respective horizontal and vertical EPIs. Our 3D face reconstruction network (FaceLFnet) comprises a densely connected architecture to learn accurate 3D facial curves from low resolution EPIs. To train the proposed FaceLFnets from scratch, we synthesize photo-realistic light field images from 3D facial scans. The curve by curve 3D face estimation approach allows the networks to learn from only 14K images of 80 identities, which still comprises over 11 Million EPIs/curves. The estimated facial curves are merged into a single pointcloud to which a surface is fitted to get the final 3D face. Our method is model-free, requires only a few training samples to learn FaceLFnet and can reconstruct 3D faces with high accuracy from single light field images under varying poses, expressions and lighting conditions. Comparison on the BU-3DFE and BU-4DFE datasets show that our method reduces reconstruction errors by over 20% compared to recent state of the art

    Randomized Benchmarking of Multi-Qubit Gates

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    As experimental platforms for quantum information processing continue to mature, characterization of the quality of unitary gates that can be applied to their quantum bits (qubits) becomes essential. Eventually, the quality must be sufficiently high to support arbitrarily long quantum computations. Randomized benchmarking already provides a platform-independent method for assessing the quality of one-qubit rotations. Here we describe an extension of this method to multi-qubit gates. We provide a platform-independent protocol for evaluating the performance of experimental Clifford unitaries, which form the basis of fault-tolerant quantum computing. We implemented the benchmarking protocol with trapped-ion two-qubit phase gates and one-qubit gates and found an error per random two-qubit Clifford unitary of 0.162±0.0080.162 \pm 0.008, thus setting the first benchmark for such unitaries. By implementing a second set of sequences with an extra two-qubit phase gate at each step, we extracted an error per phase gate of 0.069±0.0170.069 \pm 0.017. We conducted these experiments with movable, sympathetically cooled ions in a multi-zone Paul trap - a system that can in principle be scaled to larger numbers of ions.Comment: Corrected description of parallel single-qubit benchmark experiment. Results unchange
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