Advances in computer-aided crack length measurement during fatigue crack growth testing

The accurate measurement of crack length is one of the most important aspect of fatigue crack growth rate (FCGR) testing. Of the various methods available for crack length measurement, compliance technique is very popular due to the facilities it provides for easy automation. In the compliance technique, compliance crack length (CCL) rela-tions are used for correlating the compliance, computed from measurements of displacements & loads during fatigue cycling, to the crack length contained in the specimen. CCL relations are specific not only to the specimen geometry, but also to the location on the specimen body at which displacements are measured. This specificness is not very conducive to the experimentalist as it introduces errors in the measured crack length if the location of displacement measurement is not accurately maintained. With variations in specimen geometry and size, the accu-rate positioning of displacement measurement transducers is not an easy task. In order to provide greater flexi-bility in the use of the compliance technique, a new scheme has been proposed in this paper. Modelling the defo-rmation of a fracture mechanics specimen during fatigue cycling as rotation of two rigid hinge about a hringe point, the relationship between the location of the hinge-point with crack length has been established using finite element analysis for the single-edge notched three point bend specimen. Further -an iterative method has been developed which can be implemented in the background software for on-line crack length measurement. It has been shown that the iterative method converges rapidly to give the crack length with high accuracy

Compliance crack length relations for the four-point bend specimen

Compliance crack length relations for the four-point bend specimen geometry have not been reported in the literature in spite of this geometry being one of the popularly used specimens for fatigue crack growth studies. An effort has been made in the present work to fill this gap. Accordingly, the finite element technique was employed to simulate loading and calculate displacements at various locations in a four-point bend specimen. The load-displacement data thus obtained were processed to yield compliance crack length relations. These relations were employed to calculate the crack length during fatigue testing of four-point bend specimens in which the crack length was also measured by optical means. A good correlation was observed between the predicted crack length and that measured optically

Penerapan Model Pembelajaran Kooperatif Tipe Teknik Bertukar Pasangan Untuk Meningkatkan Prestasi Belajar Siswa Pada Pokok Bahasan Tata Nama Senyawa Dan Persamaan Reaksi Di Kelas X SMA Negeri 14 Pekanbaru

The research aims to increase student learning achievement on the subject compounds nomenclature and chemical reaction equation of elements in class X SMAN 14 Pekanbaru. This research was of experiment research with pretest-posttest design. The research was conducted in SMAN 14 Pekanbaru. The samples of this research were the students of class X.4 as the experimental class and students of class X.3 as the control class. In experimental class was applied cooperative learning model type pair exchange technique, while the control class was not. Data analysis technique used is the t-test. Based on analysis of data obtained tcount>ttable is 6,41 > 1,67 means that the application of model cooperative learning type pair exchange can improve student achievement on the subject compounds nomenclature and chemical reaction equation of elements in class X SMAN 14 Pekanbaru increase learning achievement category in the experimental class is based on the normalized gain score (N-Gain) relatively high at 0,73

Autonomous Mapping Robot

The purpose of this Major Qualifying Project was to design and build a prototype of an autonomous mapping robot capable of producing a floor plan of the interior of a building. In order to accomplish this, several technologies were combined including, a laser rangefinder, ultrasonic sensors, optical encoders, an inertial sensor, and wireless networking to make a small, self-contained autonomous robot controlled by an ARM9 processor running embedded Linux. This robot was designed with future expansion in mind

Discovery of a second SALMFamide gene in the sea urchin Strongylocentrotus purpuratus reveals that L-type and F-type SALMFamide neuropeptides coexist in an echinoderm species

NOTICE: this is the author’s version of a work that was accepted for publication in MARINE GENOMICS. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in MARINE GENOMICS, [VOL 3, ISSUE 2, (2010)] DOI: 10.1016/j.margen.2010.08.00

Pathologic Complete Response of HER-2 Neu-Positive Invasive Ductal Carcinoma and Ductal Carcinoma In Situ following Neoadjuvant Chemotherapy plus Trastuzumab: A Case Report and Review of Literature

Pathologic complete response (pCR) after NC has been consistently associated with improved outcomes. Residual DCIS after NC does not portray worse prognosis compared to complete eradication of all disease but has clinical implications regarding surgical management. We report a case of pCR of DCIS associated with invasive carcinoma in an HER-2 + tumor after NC plus trastuzumab despite persistence of malignant-appearing microcalcifications mammographically. A 41-year-old Caucasian female presented with a 4 × 4 cm mass in the right breast and a 2.5 cm right axillary node. Mammogram showed a 2.5 cm mass and a 12 cm area of linear pleomorphic, suspicious calcifications in the upper part of the breast. Core biopsy revealed invasive ductal carcinoma and DCIS associated with calcifications (ER 85%, PR 6%, Her2neu 3+ by IHC). Axillary node FNA was positive for malignancy. The patient received doxorubicin/cyclophosphamide (AC) → paclitaxel plus T with complete clinical and radiologic response but no significant change in the microcalcifications. Final pathology showed no residual invasive carcinoma or DCIS despite the presence of numerous ducts with microcalcifications. Documented eradication of DCIS has not been reported following NC when malignant-appearing calcifications persist and this observation may have important clinical implications regarding surgical management

Pemanfaatan Alginat Dari Alga Coklat(sargassum SP) Untuk Produksi Plastik Yang Biodegradable

The developing of biodegradable plastic is an alternative to overcome the problemon the abundance of plastic in environment. This research aims to 1) learn the productionprocess of biodegradable plastic from alginat, 2) learn the easy of biodegradation processfrom plastic material, 3) learn the influence of the length of biodegradation toward theweight loss of plastic from alginat, and 4) compare the degradability between LLDPE((Low Liniear Density Polyethylene) plastic and HDPE (High Density Polyethylene).Alginat was from the extraction of brown algae and Na2CO3 12% , then it was madeas gel by adding HCL 10%. The production process of biodegradable plastic was done byblending-tecnique (LLDPE dan HDPE) with alginat. The test of biodegradable plasticwas done by piling soil up for six days. The speed of weight loss of plastic was shown bythe percent of plastic weight loss.The quatitative analysis of alginat isolated from brown algae with concentration1;, 0.75; 0.5; 0.25 and 0.125% produces the viscosity 2.48; 2.05; 1.89; 1.71; dan 1.62poise, and also specific gravity of alginat 1.085; 1.081; 1.078; 1.083; and 1.078 g/ml. Thebiodegradation result of LLDPE, HDPE, LLDPE plus Alginat and HDPE plus Alginatfind the average of weight loss for three days are 9.03; 4.76; 0; and 16.86%, and for sixdays 0; 0.75; 9.45; and 6.08%. The biodegradable plastic with HDPE plus alginat isbiodegraded faster because of having short chain of ramification

Measurement-induced disturbances and nonclassical correlations of Gaussian states

We study quantum correlations beyond entanglement in two-mode Gaussian states of continuous-variable systems by means of the measurement-induced disturbance (MID) and its ameliorated version (AMID). In analogy with the recent studies of the Gaussian quantum discord, we define a Gaussian AMID by constraining the optimization to all bi-local Gaussian positive operator valued measurements. We solve the optimization explicitly for relevant families of states, including squeezed thermal states. Remarkably, we find that there is a finite subset of two-mode Gaussian states comprising pure states where non-Gaussian measurements such as photon counting are globally optimal for the AMID and realize a strictly smaller state disturbance compared to the best Gaussian measurements. However, for the majority of two-mode Gaussian states the unoptimized MID provides a loose overestimation of the actual content of quantum correlations, as evidenced by its comparison with Gaussian discord. This feature displays strong similarity with the case of two qubits. Upper and lower bounds for the Gaussian AMID at fixed Gaussian discord are identified. We further present a comparison between Gaussian AMID and Gaussian entanglement of formation, and classify families of two-mode states in terms of their Gaussian AMID, Gaussian discord, and Gaussian entanglement of formation. Our findings provide a further confirmation of the genuinely quantum nature of general Gaussian states, yet they reveal that non-Gaussian measurements can play a crucial role for the optimized extraction and potential exploitation of classical and nonclassical correlations in Gaussian states. © 2011 American Physical Society

STUDY ON THE ANTIBACTERIAL ACTIVITY OF FRUIT EXTRACTS OF KLUTUK BANANA (MUSA BALBISIANA COLLA) AGAINST SHIGELLA DYSENTERIAE ATCC 13313

Objective: The purpose of this study is to determine the antibacterial activity of Klutuk Banana (Musa balbisiana colla) fruit extracts against Shigella dysenteriae ATCC 13313 and the amount of potassium to the discovery of anti-dysentery drug candidates.Methods: The simplisia of Klutuk banana fruit was extracted with ethanol using a maceration method. The phytochemical screening of ethanol extract was performed using standard procedures. Determination thin layer chromatography (TLC) profile of the extract was performed using a thin layer plate. The antibacterial activity was investigated using agar well diffusion technique. The minimum inhibitory concentrations (MIC) were determined by a serial microdilution method, whereas the minimum bactericidal concentration (MBC) was done by subculturing the MIC result onto agar medium. Potassium levels of the extract were carried out quantitatively using atomic absorption spectrophotometry.Results: The phytochemical analysis revealed the presence of flavonoids, polyphenols, tannins, monoterpenoid and sesquiterpenoids, quinones, and saponins. The TLC results prove the existence of flavonoids in the tested extract. The content of secondary metabolites that can act as an antibacterial, strengthen the antibacterial activity of ethanol extract of Klutuk banana against S. dysenteriae 13313 with MBC values in the range of 5-10%w/v. Potassium levels in the ethanol extract of Klutuk banana fruits contain potassium as much as 2.919% (29 190 ppm).Conclusion: It can be concluded that the ethanol extract of Klutuk banana fruits is more potent as antibacterial against S. dysenteriae than as potassium supplier in hypokalemia therapy

Temperature dependent photoluminescence of lateral polarity junctions of metal organic chemical vapor deposition grown GaN

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Journal of Applied Physics 110, 093503 (2011) and may be found at https://doi.org/10.1063/1.3656987.We report on fundamental structural and optical properties of lateral polarity junctions in GaN. GaN with Ga- to N-polar junctions was grown on sapphire using an AlN buffer layer. Results from scanning electron microscopy and Raman spectroscopy measurements indicate a superior quality of the Ga-polar GaN. An extremely strong luminescence signal is observed at the inversion domain boundary (IDB). Temperature dependent micro photoluminescence measurements are used to reveal the recombination processes underlying this strong emission. At 5 K the emission mainly arises from a stripe along the inversion domain boundary with a thickness of 4-5 μm. An increase of the temperature initially leads to a narrowing to below 2 μm emission area width followed by a broadening at temperatures above 70 K. The relatively broad emission area at low temperatures is explained by a diagonal IDB. It is shown that all further changes in the emission area width are related to thermalization effects of carriers and defects attracted to the IDB. The results are successfully used to confirm a theoretical model for GaN based lateral polarity junctions. Due to the strong and pronounced emission of IDBs even at elevated temperatures, it is demonstrated that lateral polarity junctions exhibit a strong potential for future high efficiency devices.DFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, Bauelement