283,856 research outputs found

    The Influence of Specimen Misalignment on Wear in Conforming Pin on Disk Tests

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    A pin-on-disk test apparatus was modified to decrease the degree of misalignment between the pin end and the disk counterface. This was achieved by separate alignment of both pin and disk. Disk alignment was allowed by incorporating a kinematic three-ball arrangement into the disk under-face. A self-aligning pin alignment system was introduced which did not require the perpendicularity of the pin to be measured. The unmodified system had an alignment within that permitted by the ASTM G99-95a standard. However, the modified, and improved, alignment system produced significant changes in recorded wear behaviour in comparison with the unmodified system. The standard deviation of the wear data was considerably reduced and the correlation of the wear data with applied load significantly improved. The modified alignment also reduced the absolute value of wear recorded. This effect was observed for both wear volume assessed from mass change and wear volume assessed from pin height change. The reduced constraint of a misaligned pin in comparison with that of a well-aligned pin may account for the difference in these results

    Risks of Offline Verify PIN on Contactless Cards

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    Contactless card payments are being introduced around the world al- lowing customers to use a card to pay for small purchases by simply placing the card onto the Point of Sale terminal. Contactless transactions do not require veri- fication of the cardholder’s PIN. However our research has found the redundant verify PIN functionality is present on the most commonly issued contactless credit and debit cards currently in circulation in the UK. This paper presents a plausible attack scenario which exploits contactless verify PIN to give unlimited attempts to guess the cardholder’s PIN without their knowledge. It also gives experimental data to demonstrate the practical viability of the attack as well as references to support our argument that contactless verify PIN is redundant functionality which compromises the security of payment cards and the cardholder

    A cohesive zone model for predicting delamination suppression in z-pin reinforced laminates

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    This paper presents a cohesive zone model based finite element analysis of delamination resistance of z-pin reinforced double cantilever beam (DCB). The main difference between this and existing cohesive zone models is that each z- pin bridging force is governed by a traction-separation law derived from a meso- mechanical model of the pin pullout process, which is independent of the fracture toughness of unreinforced laminate. Therefore, two different traction- separation laws are used: one representing the toughness of unreinforced laminate and the other the enhanced delamination toughness owing to the pin bridging action. This approach can account for the large scale bridging effect and avoid using concentrated pin forces, thus removing the mesh dependency and permitting more accurate analysis solution. Computations were performed using a simplified unit strip model. Predicted delamination growth and load vs. displacement relation are in excellent agreement with the prediction by a complete model, and both models are in good agreement with test measured load vs. displacement relation. For a pinned DCB specimen, the unit strip model can reduce the computing time by 85%

    Fatigue delamination behaviour of unidirectional carbon fibre/epoxy laminates reinforced by Z-Fiber® pinnin

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    -Pin reinforced carbon-fibre epoxy laminates were tested under Mode I and Mode II conditions, both quasi-statically and in fatigue. Test procedures were adapted from existing standard or pre-standard tests. Samples containing 2% and 4% areal densities of carbon-fibre Z-pins (0.28mm diameter) were compared with unpinned laminates. Quasi-static tests under displacement control yielded a dramatic increase of the apparent delamination resistance. Specimens with 2% pin density failed in Mode I at loads 170N, equivalent to an apparent GIC of 2kJ/m2. Fatigue testing under load control showed that the presence of the through- thickness reinforcement slowed down fatigue delamination propagation

    PIN generation using EEG : a stability study

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    In a previous study, it has been shown that brain activity, i.e. electroencephalogram (EEG) signals, can be used to generate personal identification number (PIN). The method was based on brain–computer interface (BCI) technology using a P300-based BCI approach and showed that a single-channel EEG was sufficient to generate PIN without any error for three subjects. The advantage of this method is obviously its better fraud resistance compared to conventional methods of PIN generation such as entering the numbers using a keypad. Here, we investigate the stability of these EEG signals when used with a neural network classifier, i.e. to investigate the changes in the performance of the method over time. Our results, based on recording conducted over a period of three months, indicate that a single channel is no longer sufficient and a multiple electrode configuration is necessary to maintain acceptable performances. Alternatively, a recording session to retrain the neural network classifier can be conducted on shorter intervals, though practically this might not be viable

    PEMANTAUAN KUALITAS UDARA DI DALAM RUANGAN HR-05 INSTALASI ELEMEN BAKAR EKSPERIMENTAL

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    ABSTRAK PEMANTAUAN KUALITAS UDARA DI DALAM RUANGAN HR-05 DI INSTALASI ELEMEN BAKAR EKSPERIMENTAL. Pemantauan kualitas udara di dalam ruangan Hot Room-05 (HR-05) di Instalasi Elemen Bakar Eksperimental (IEBE) telah dilakukan. Tujuan pemantauan adalah untuk mengetahui kualitas udara di dalam ruangan HR-05, antara lain konsentrasi debu, temperatur, kelembaban, dan laju ventilasi. Metoda pemantauan yang digunakan adalah mengukur konsentrasi debu, temperatur, kelembaban dan laju ventilasi di udara HR-05 pada 5 posisi yang berbeda. Konsentrasi debu yang diukur adalah PM2,5 (partikulat debu respirable), menggunakan alat Aerosol Monitor. Temperatur dan kelembaban udara diukur menggunakan alat Thermo Hygrometer, sedangkan laju ventilasi diukur menggunakan alat Digital anemometer. Kualitas udara di dalam ruangan HR-05 tersebut, kemudian dibandingkan dengan persyaratan Kesehatan Lingkungan Kerja Perkantoran dan Industri. Hasil pengukuran kualitas udara di dalam ruangan HR-05, sebagai berikut: konsentrasi partikulat debu respirable sebesar (0,053 ± 0,001) mg/m3, temperatur sebesar (29,60 ± 0,38) 0C, kelembaban sebesar (66,40 ± 0,50) %, laju ventilasi sebesar (0,16 ± 0,05) m/detik. Hasil pemantauan kualitas udara di dalam ruangan HR-05 di IEBE : konsentrasi partikulat debu respirable dan laju ventilasi memenuhi persyaratan, sedangkan temperatur dan kelembaban di atas batasan yang diizinkan pada persyaratan Kepmenkes R.I No. 1405/MENKES/SK/XI/2002. Kualitas udara di dalam ruangan HR-05 belum sepenuhnya memenuhi persyaratan Kesehatan Lingkungan Kerja Perkantoran dan Industri, sehingga perlu dilakukan upaya peningkatan pengoperasian sistem ventilasi dan aircondisioning (AC) yang optimal. Kata kunci : partikulat debu respirable, kelembaban, laju ventilasi, temperatur

    SISTEM PROTEKSI FISIK INSTALASI NUKLIR PTBBN BAGIAN I: PENERAPAN SISTEM PROTEKSI FISIK DI INSTALASI RADIOMETALURGI

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    ABSTRAK SISTEM PROTEKSI FISIK INSTALASI NUKLIR PTBBN BAGIAN I: PENERAPAN SISTEM PROTEKSI FISIK DI INSTALASI RADIOMETALURGI. Suatu observasi terhadap penerapan SPF di IRM telah dilakukan untuk mengetahui bagaimana SPF tersebut berfungsi. Observasi dilakukan dengan cara peninjauan ke lokasi SPF terpasang, pengambilan gambar, pengumpulan informasi dan pemeriksaan dokumen. Data observasi kemudian dibandingkan dengan prinsip-prinsip dasar SPF. Hasil menunjukkan bahwa penerapan SPF di IRM telah meliputi prinsip pencegahan dengan pemasangan rambu keamanan/ keselamatan, penjagaan instalasi yang ketat dan pemasangan sistem deteksi/ pengawasan. Prinsip pendeteksian diterapkan dengan mengoperasikan sejumlah sensor berupa sensor CCTV, sensor radiasi, sensor metal dan sensor kartu magnetik. Prinsip penundaan dilakukan dengan cara berlapis, diantaranya pagar berduri, dinding bangunan gedung dan pintu besi berkunci, dua lapis akses masuk/ kontrol personil ke daerah vital (laboratorium), ruangan berkunci dan wadah-wadah bahan radioaktif yang besar dan berat termasuk hotcell. Prinsip menggagalkan diterapkan dengan menyediakan regu keamanan instalasi yang bertugas 24 jam/hari, melaksanakan patroli rutin dan telah terlatih untuk tujuan melumpuhkan intrusi. Jadi penerapan SPF di IRM telah memenuhi prinsip-prinsip dasar suatu SPF.   Kata kunci: IRM, sistem proteksi fisik, pencegahan, pendeteksian, penundaan, menggagalka

    Introduzione

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    Il volume raccoglie contributi relativi alle declinazioni contemporanee dell'uguaglianza, nell'ambito dei diritti, dei doveri e della loro sostenibilità. L'introduzione illustra questi aspetti inquadrandone i problemi

    Introduzione: i nuovi diritti

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    L'introduzione del curatore inquadra il volume nel contesto contemporaneo. L'evoluzione del panorama giuridico ha recentemente mostrato un'evouzione significativa nel modo d'intendere i diritti e nelle forme della loro espansione: dai diritti collettivi, a quelli individuali, a quelli individuali e comunitari insieme; dai Parlamenti alle Corti. Si tratta di aspetti rilevanti, che i singoli contributi mettono in luce evidenziandone il sostrato antropologico

    EVALUASI KESIAPSIAGAAN NUKLIR DI INSTALASI RADIOMETALURGI BERDASARKAN PERKA BAPETEN NOMOR 1 TAHUN 2010

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    EVALUASI KESIAPSIAGAN NUKLIR DI INSTALASI RADIUOMETALURGI BERDASARKAN PERKA BAPETEN NOMOR 1 TAHUN 2010. Telah dilakukan evaluasi kesiapsiagan nuklir Instalasi Radiometalurgi (IRM) berdasarkan Perka BAPETEN nomor 1 tahun 2010. Perka BAPETEN nomor 1 tahun 2010 pasal 50 menyatakan bahwa pada saat peraturan ini mulai berlaku, maka Keputusan Kepala BAPETEN No. 05-P/Ka-BAPETEN/I-03 dicabut dan dinyatakan tidak berlaku. Panduan kesiapsiagaan nuklir PTBN sat ini mengacu pada Keputusan Kepala BAPETEN No. 05-P/Ka-BAPETEN/I-03, sehingga tidak dapat diberlakukan lagi. Tujuan evaluasi kesiapsiagaan nuklir IRM adalah untuk mengetahui kesiapan seluruh unsur infrastruktur dan kemampuan fungsi penanggulangan kedaruratan nuklir. Metoda evaluasi kesiapsiagan nuklir IRM dilakukan dengan menggunakan diagram alir. Infrastruktur IRM yang terdiri dari: organisasi PKN; koordinasi penanggulangan; fasilitas dan peralatan; prosedur penanggulangan; serta pelatihan kedaruratan nuklir telah terpenuhi. Fungsi penanggulangan yang terdiri dari: identifikasi, pelaporan dan pengaktifan; tindakan mitigasi; serta tindakan perlindungan untuk petugas penanggulangan dan pekerja untuk tujuan penanggulangan mempunyai kemampuan yang memadai. Kesimpulan yang dapat diambil dari hasil evaluasi kesiapsiagaan nuklir IRM berdasarkan Perka BAPETEN nomor 1 tahun 2010, diketahui bahwa unsur infrastruktur telah terpenuhi, dan fungsi penanggulangan kedaruratan nuklir mempunyai kemampuan yang memadai. Program kesiapsiagan nuklir IRM dapat segera direvisi, sehingga memuat unsur infrastruktur dan fungsi penanggulangan serta dapat digunakan sebagai pengganti Panduan kesiapsiagaan nuklir PTBN yang lama/sebelumnya.   Kata kunci: evaluasi, fungsi penanggulangan, unsur infrastruktur
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