Emergency shutdown valve reliability function test by automated Partial Stroke Testing System

Partial stroke testing (PST) is a technique that is regularly practiced in oil and gas industries to test the emergency shutdown (ESD) valve by closing a certain percentage of the valve position and stop any flow through the pipeline. Generally, it only functions when there is an emergency occurring in the production system. When the ESD valve remains in one position for a long period, there is a risk and potential of fail on demand which is, the ESD valve fail to operate during the emergency shutdown. This testing can reveal approximately 75 of unrevealed failures in valves. It can also provide predictive maintenance data that can contribute to the extension of the preventive maintenance for the ESD valve. The objectives of this paper are to design, simulate, build and test the performance of the automated PST system based on PLC. Four guidelines and methodology are used in this work. First, understanding the operation of the PST system. Then, the utilization of the capability of MATLAB-Simulink software as the simulation tool for the PST design system. Next, designing the PST automated system based on PLC design and lastly, testing the performance of the PST design system using lab scale PST system prototype that has been built. Results of the project shows that the PST system is successfully designed and simulated via MATLAB-Simulink and the PLC programming is working in the correct order as performed on the prototype

A question of hierarchy: matter effects with atmospheric neutrinos and anti-neutrinos

It is by now established that neutrinos mix, have (different) non-zero masses, and therefore oscillate. The oscillation parameters themselves, however, are not all well-known. An open problem is that of the neutrino mass hierarchy. We study the possibility of determining the neutrino mass hierarchy with atmospheric neutrinos using an iron calorimeter detector capable of charge identification such as the proposed MONOLITH and ICAL/INO detectors. We find that such detectors are sensitive to the sign of the mass-squared difference, \delta_{32} = m_3^2 - m_2^2, provided the as-yet unknown mixing angle between the first and third generations, \theta_{13}, is greater than 6 degrees (\sin^2 2\theta_{13} > 0.04). A result with a significance greater than 90% CL requires large exposures (more than 500 kton-years) as well as good energy and angular resolution of the detected muons (better than 15%), especially for small \theta_{13}. Hence obtaining definitive results with such a detector is difficult, unless \theta_{13} turns out to be large. In contrast, such detectors can establish a clear oscillation pattern in atmospheric neutrinos in about 150 kton-years, therefore determining the absolute value of \delta_{32} and \sin^2 2 \theta_{23} to within 10%.Comment: 36 pages revtex with 14 eps figures; new section on statistical significance when detector resolution is include

Theoretical Analysis of a Two-stage Sagnac loop filter using Jones Matrices

In this work, a theoretical analysis of a Sagnac loop filter (SLF) with two-stage polarization maintaining fibers (PMFs) and polarization controllers (PCs) is presented. The transmission function of this two-stage SLF is calculated in detail by using Jones matrix. The calculation is performed in order to investigate the filtering characteristics. The theoretical results show that the wavelength interval is depending on the dynamic settings of the length of the PMFs and the polarization angle of the PCs. By changing the polarization angle of the PCs, a multiple of single, dual or triple wavelength in each channel can be achieved. Based on this study, a flat multiwavelength spectrum can be obtained by adjusting the PMFs and the PCs in the two-stage SLF. This finding significantly contributes to the generation of multiwavelength fiber laser (MWFL) that can be used for many optical applications

Low Cost Tunable Bandstop Filter Design of Defected Ground Structure using FR4 Substrate

Abstract- This paper presents a tunable bandstop filter design using defected ground structure (DGS) where FR4 substrate is used as a low cost solution compared to others substrate such as Teflon and Rogers RT/Duroid. Thus, the performance of the tunable DGS bandstop filter using FR4 substrate is analyzed in this paper. Besides, analytical modeling of the tunable bandstop filter is derived and discussed as well where the tunable element of varactor diodes are used in the design. As result, tuning range in simulation is achieved from center frequency of 0.445 to 1.99GHz while the tuning range of fabricated filteris from 0.495 to 1.88GHz. The range of bandstop attenuation is between 9 to 46 dB for tuning voltage between 0 to 8 V

Neutrino oscillation probabilities: Sensitivity to parameters

We study in detail the sensitivity of neutrino oscillation probabilities to the fundamental neutrino parameters and their possible determination through experiments. The first part of the paper is devoted to the broad theme of isolating regions in the neutrino (and anti-neutrino) energy and propagation length that are sensitive to the oscillation parameters. Such a study is relevant to neutrinos both from the Earth's atmosphere or from a neutrino factory. For completeness we discuss the sensitivity, however small, to the parameters involved in a three-generation framework, and to the Earth matter density profile. We then study processes relevant to atmospheric neutrinos which are sensitive to and allow precision measurements of the mixing angle theta_23 and mass-squared difference delta_32 apart from the mixing angle theta_13. Crucial to this analysis is charge identification; detectors having this capability can isolate these matter effects. In particular, we address the issue of using matter effects to determine whether the mixing angle theta_23 is maximal, and, if not, to explore how well its octant can be determined. When realistic detector resolutions are included, we find that deviations of about 15% (20%) from a maximal value of sin^2 theta_23=1/2 can be measured at 95% (99%) CL provided theta_13 is non-zero, sin^2 theta_13 >= 0.015, and the neutrino mass ordering is normal, with fairly large exposures of 1000 kton-years.Comment: 37 pages Latex file, 30 eps figure files; minor typos fixe

Four-wave mixing cascades seeded by a multiwavelength Brillouin–erbium fiber laser

Four-wave mixing (FWM) cascades which are seeded by a multiwavelength Brillouin–erbium fiber laser (MBEFL) are experimentally demonstrated in this work. The MBEFL, which is based on virtual mirror feedback, is successful in providing the seed for the FWM cascades. The stimulated Brillouin scattering and parametric gain for the development of the MBEFL and FWM cascades, respectively, are provided by a 12 km dispersion-shifted fiber (DSF). By launching the MBEFL into the DSF, as many as 80 comb lines can be generated when the Brillouin pump (BP) wavelength is tuned at 1560 nm. Analysis of FWM cascades as a function of BP wavelength shows that the number of comb lines is greater at the anomalous-dispersion region of the DSF, suggesting that the phase mismatch is minimized in that regime

Metabolisme Benzonitril oleh Flavobacterium SP. NUB 1

Metabolism of Benzonitriles by Flavobacterium sp. NUB 1. Flavobacterium sp. NUB 1 was isolated from industrial waste of PT. Petrokimia Gresik. The bacterium was able to utilize benzonitrile and acetonitrile and propionitril as the sole source of carbon and nitrogen. Growth on benzonitrile gave higher growth rate and biomass yield than growth on acetonitrile and propionitrile. When Flavovobacterium sp. NUB1 grew on benzonitril 15 mM , the doubling time is 9 hours 54 minutes and the specific growth rate (?) was 0,07 h-1. Whole cell of Flavobacterium sp. NUB 1 could hydrolyzed aromatic and aliphatic nitriles. The bacteria isolate has ability in metabolism of acetonitrile greater than benzonitrile. Activity of nitrile hydratase and amidase are more dominant than nitrilase in metabolism of benzonitrile

Meningkatkan Technical Skill Siswa Smk Teknik Bangunan Melalui Pelaksanaan Praktik Kerja Industri

This paper aims to expose the study of: (1) technical skill; (2) the working practices of the industry (Prakerin); and (3) technical skill on implementation prakerin. Conclusions it can be concluded that, the real form of Prakerin is the implementation of the system of education in SMK is Double System Education (PSG). The program was drawn up jointly between prakerin school and industrial world in order to meet the needs of students. The party was active in the activities of prakerin include: (1) the implementing party as students practice; and (2) the industrial world and the teacher as the party that train students. The existence of activities expected prakerin can give students experience before entering the world of work. Through the activities, indirectly prakerin students have gained technical skill required as a provision for entering the workforce. Given the current state of infrastructure development is preferred, the demand for construction workers is the main one. Graduates of Vocational School building techniques is expected to have the technical skill to be able to compete with the foreign worker entering the era of the MEA as of now.Tulisan ini bertujuan untuk memaparkan kajian tentang: (1) technical skill; (2) Praktik Kerja Industri (Prakerin); dan (3) technical skill pada pelaksanaan prakerin. Kesimpulan yang dapat disimpulkan bahwa, prakerin merupakan wujud nyata dari pelaksanaan sistem pendidikan di SMK yaitu Pendidikan Sistem Ganda (PSG). Program prakerin disusun bersama antara sekolah dan dunia industri dalam rangka memenuhi kebutuhan siswa. Pihak yang aktif dalam kegiatan prakerin, meliputi (1) siswa sebagai pihak pelaksana praktik; serta (2) dunia industri dan guru sebagai pihak yang melatih siswa. Adanya kegiatan prakerin diharapkan dapat memberi pengalaman siswa sebelum memasuki dunia kerja. Melalui kegiatan prakerin, secara tidak langsung siswa telah mendapatkan technical skill yang dibutuhkan sebagai bekal memasuki dunia kerja. Mengingat pembangunan infrastruktur negara saat sekarang lebih diutamakan, kebutuhan pekerja konstruksi menjadi hal yang utama. Lulusan SMK teknik bangunan diharapkan memiliki technical skill agar dapat bersaing dengan tenaga asing memasuki era MEA seperti sekarang

Reduced graphene oxide-multiwalled carbon nanotubes hybrid film with low Pt loading as counter electrode for improved photovoltaic performance of dye-sensitised solar cells

In this work, the role of reduced graphene oxide (rGO) with hyperbranched surfactant and its hybridisation with multiwalled carbon nanotubes (MWCNTs) and platinum (Pt) nanoparticles (NPs) as counter electrode (CE) were investigated to determine the photovoltaic performance of dye-sensitised solar cells (DSSCs). Sodium 1,4-is(neopentyloxy)-3-(neopentyloxycarbonyl)- 1,4-dioxobutane-2-sulphonate (TC14) surfactant was utilised as dispersing and stabilising agent in electrochemical exfoliation to synthesise graphene oxide (GO) as initial solution for rGO production prior to its further hybridisation and fabrication as thin film. A chemical reduction process utilising hydrazine hydrate was conducted to produce rGO due to the low temperature process and water-based GO solution. Subsequently, hybrid solution was prepared by mixing 1 wt% MWCNTs into the produced rGO solution. TC14-rGO and TC14-rGO_MWCNTs hybrid solution were transferred into fluorine-doped tin oxide substrate to fabricate thin film by spraying deposition method. Finally, the CE films were prepared by coating with thin Pt NPs. Photoanode film was prepared by a two-step process: hydrothermal growth method to synthesise titanium dioxide nanowires (TiO2 NWs) and subsequent squeegee method to apply TiO2 NPs. According to solar simulator measurement, the highest energy conversion efficiency (η) was achieved by using CE-based TC14-rGO_MWCNTs/Pt (1.553%), with the highest short current density of 4.424 mA/cm2. The highest η was due to the high conductivity of CE hybrid film and the morphology of fabricated TiO2 NWs/TiO2 NPs. Consequently, the dye adsorption was high, and the photovoltaic performance of DSSCs was increased. This result also showed that rGO and rGO_MWCNTs hybrid can be used as considerable potential candidate materials to replace Pt gradually