Corrosion study of pipeline material for seabed sediment in tropical climate

Corrosive environments such as marine sediments can cause corrosion to steel pipelines at any time when certain conditions are met. Seabed sediment could cause severe corrosion damage due to its corrosiveness to the pipelines buried under it. Many consequences could take place in case if there is incident in oil/gas pipelines. Successfully identifying elements of corrosion in marine sediment would enhance the future of steel structure protection and monitoring systems. This article focuses on the behaviour of corrosion rate of steel located near shore environment and the aim is to determine the effect of sediment on corrosion of steel. To investigate that, simulated near shore sediment conditions have been used where the steel coupons buried in sediments which have different characteristics. Weight loss technique has been implemented to determine the weight loss rate of the steel specimens. Based on the results of this study, metal weight loss increases as the duration of exposure to seabed sediment environment become longer. The sea sediment simulated condition has given significant levels of corrosion. Conclusively, the corrosion rate of steel in seabed sediment located in tropical region is complicated and further studies are suggested

One-loop contributions of charginos and neutralinos to W-pair production in E+ E- collisions

We study the one-loop effects of charginos and neutralinos on the helicity amplitudes for \eeww in the minimal supersymmetric standard model. The calculation is tested by using two methods. First, the sum rule for the form factors between \eeww and the process where the external $W^\pm$ bosons are replaced by the corresponding Goldstone bosons $\omega^\pm$ is employed to test the analytic expression and the accuracy of the numerical program. Second, the decoupling property in the large mass limit is used to test the overall normalization of the amplitudes. These two tests are most effectively carried out when the amplitudes are expanded in terms of the modified minimal subtraction ($\bar{\rm MS}$) couplings of the standard model. The resulting perturbation expansion is valid at collider energies below and around the threshold of the light supersymmetric particles. We find that the corrections to the cross section of the longitudinally polarized $W$-pair production can be as large as -1.4% at the threshold of the light chargino-pair production for large scattering angles. We also study the effects of the CP-violating phase in the chargino and neutralino sectors on the helicity amplitudes. We find that the resulting CP-violating asymmetries can be at most 0.1%.Comment: 30 pages, 25 figures, Final verision, To appear in Physical Review D, Several sentences are improve

Design, analysis and construction of an impressed current electric device for cathodic protection

This paper aimed at designing, analyzing and fabricating an impressed current electric device. Cathodic protection is a means to prevent corrosion by applying a flow of electrical current from an external source (anode) through the environment and to the metallic structure that is being protected. The protective current changes the environment around the metal thus halting the corrosion reaction. Cathodic protection is used to prevent corrosion in a wide range of applications where the structure being protected is surrounded by an environment that allows current flow. The impressed current cathodic protection systems have the benefit of using an external power supply to drive current. The study used sea water as electrolyte with locally constructed transformer rectifier and to select a proper material for the construction so as to illustrate the effect and how the impressed current system functions. The general performance evaluation was found that the device has a net driving potential of 10.5V and a life expectancy of 128 years of the anode. In conclusion, the construction was successful and easy to operate which can be used to protect metal structure against corrosion

CP-odd Phase Correlations and Electric Dipole Moments

We revisit the constraints imposed by electric dipole moments (EDMs) of nucleons and heavy atoms on new CP-violating sources within supersymmetric theories. We point out that certain two-loop renormalization group corrections induce significant mixing between the basis-invariant CP-odd phases. In the framework of the constrained minimal supersymmetric standard model (CMSSM), the CP-odd invariant related to the soft trilinear A-phase at the GUT scale, theta_A, induces non-trivial and distinct CP-odd phases for the three gaugino masses at the weak scale. The latter give one-loop contributions to EDMs enhanced by tan beta, and can provide the dominant contribution to the electron EDM induced by theta_A. We perform a detailed analysis of the EDM constraints within the CMSSM, exhibiting the reach, in terms of sparticle spectra, which may be obtained assuming generic phases, as well as the limits on the CP-odd phases for some specific parameter points where detailed phenomenological studies are available. We also illustrate how this reach will expand with results from the next generation of experiments which are currently in development.Comment: 31 pages, 21 eps figures; v2: additional remarks on 2-loop threshold corrections and references added; v3: typos corrected, to appear in Phys. Rev.

Artificial neural network for non-intrusive electrical energy monitoring system

This paper discusses non-intrusive electrical energy monitoring (NIEM) system in an effort to minimize electrical energy wastages. To realize the system, an energy meter is used to measure the electrical consumption by electrical appliances. The obtained data were analyzed using a method called multilayer perceptron (MLP) technique of artificial neural network (ANN). The event detection was implemented to identify the type of loads and the power consumption of the load which were identified as fan and lamp. The switching ON and OFF output events of the loads were inputted to MLP in order to test the capability of MLP in classifying the type of loads. The data were divided to 70% for training, 15% for testing, and 15% for validation. The output of the MLP is either ‘1’ for fan or ‘0’ for lamp. In conclusion, MLP with five hidden neurons results obtained the lowest average training time with 2.699 seconds, a small number of epochs with 62 iterations, a min square error of 7.3872×10-5, and a high regression coefficient of 0.99050

Composition of Soft Set Relations and Construction of Transitive Closure

In [3] concepts of soft set relations, partition, composition and function are discussed. In this paper, we present composition of relations in soft set context and give their matrix representation. Finally, the concepts of reflexive, symmetric and transitive closure are presented and show that construction of transitive closure in soft set satisfies Warshall’s Algorithm

Partial Ordering in Soft Set Context

In [1], [2], [3], [4], [5], [6] and [7] basic introduction of soft set is discussed with examples. The main aim of this paper is develop partial ordering in soft set context.

Quantum states in a magnetic anti-dot

We study a new system in which electrons in two dimensions are confined by a non homogeneous magnetic field. The system consists of a heterostructure with on top of it a superconducting disk. We show that in this system electrons can be confined into a dot region. This magnetic anti-dot has the interesting property that the filling of the dot is a discrete function of the magnetic field. The circulating electron current inside and outside the anti-dot can be in opposite direction for certain bound states. And those states exhibit a diamagnetic to paramagnetic transition with increasing magnetic field. The absorption spectrum consists of many peaks, some of which violate Kohn's theorem, and which is due to the coupling of the center of mass motion with the other degrees of freedom.Comment: 6 pages, 12 ps figure

One-loop Neutron Electric Dipole Moment from Supersymmetry without R-parity

We present a detailed analysis together with exact numerical calculations on one-loop contributions to neutron electric dipole moment from supersymmetry without R-parity, focusing on the gluino, chargino, and neutralino contributions. Apart from the neglected family mixing among quarks, complete formulae are given for the various contributions, through the quark dipole operators, to which the present study is restricted. We discuss the structure and main features of the R-parity violating contributions and the interplay between the R-parity conserving and violating parameters. In particular, the parameter combination $\mu_i^*\lambda^{\prime}_{i11}$, under the optimal parametrization adopted, is shown to be solely responsible for the R-parity violating contributions in the supersymmetric loop diagrams. While $\mu_i^*\lambda^{\prime}_{i11}$ could bear a complex phase, the latter is not necessary to have a R-parity violating contribution.Comment: 43 pages Revtex with 15 eps- and 4 ps- figure files incoporated; proofread version to be published in Phys. Rev.

Pengembangan Perluasan Produk Penerapan Model Pembelajaran Gavala Bagi Guru Kimia di Kabupaten Ogan Komering Ulu Sumatera Selatan

Tujuan kegiatan pengabdian ini adalah tersusunnya contoh Rencana Program Pembelajaran kimia SMA dan/atau SMK bernuansa Kurikulum 2013 terintegrasi Model Pembelajaran GAVALA dan simulasi terbatas keterampilan penerapan Model GAVALA. Khalayak sasaran yang sangat strategis untuk kegiatan pengabdian kepada masyarakat ini adalah 10 guru kimia dari SMAN dan SMKN di Kabupaten Ogan Komering Ulu Sumatera Selatan. Model kegiatan adalah pengembang perluasan penerapan produk, metode pelaksanaan berupa presentasi, ipteks yang diintroduksi adalah Model Pembelajaran GAVALA. Peningkatan itu berupa tersusunnya contoh Rencana Program Pembelajaran Model GAVALA dan simulasi terbatas praktik Model Pembelajaran GAVALA di depan para peserta pengabdian. Simpulan dari kegiatan pengabdian pada masyarakat ini adalah Para guru sebagai khalayak sasaran dapat menerapkan Model Pembelajaran GAVALA. Peningkatan kemampuan menerapkan itu berupa tersusunnya contoh kegiatan dalam Rencana Pelaksanaan Pembelajaran bernuansa Model Pembelajaran GAVALA. Peningkatan itu dibuktikan dengan gain skor sebesar 1,00 dengan kategori tinggi. Saran dari kegiatan pengabdian pada masyarakat ini adalah agar guru khalayak sasaran dapat menerapkan Model Pembelajaran GAVALA pelaksanaan pembelajaran di kelas