Towards the Formal Reliability Analysis of Oil and Gas Pipelines

It is customary to assess the reliability of underground oil and gas pipelines in the presence of excessive loading and corrosion effects to ensure a leak-free transport of hazardous materials. The main idea behind this reliability analysis is to model the given pipeline system as a Reliability Block Diagram (RBD) of segments such that the reliability of an individual pipeline segment can be represented by a random variable. Traditionally, computer simulation is used to perform this reliability analysis but it provides approximate results and requires an enormous amount of CPU time for attaining reasonable estimates. Due to its approximate nature, simulation is not very suitable for analyzing safety-critical systems like oil and gas pipelines, where even minor analysis flaws may result in catastrophic consequences. As an accurate alternative, we propose to use a higher-order-logic theorem prover (HOL) for the reliability analysis of pipelines. As a first step towards this idea, this paper provides a higher-order-logic formalization of reliability and the series RBD using the HOL theorem prover. For illustration, we present the formal analysis of a simple pipeline that can be modeled as a series RBD of segments with exponentially distributed failure times.Comment: 15 page

Perbandingan Pendekatan Konstruktivisme antara Model Pembelajaran Discovery Learning dan Reception Learning terhadap Kemampuan Berpikir Kritis dan Hasil Belajar Peserta Didik Kelas X SMA Negeri 3 Takalar

Penelitian ini bertujuan untuk mengetahui perbedaan yang signifikan kemampuan berfikir kritis dan hasil belajar peserta didik kelas X SMA Negeri 3 Takalar dengan menggunakan model pembelajaran Discovery Learning dan Reception Learning. Metode penelitian yang digunakan yaitu Quasi Eksperimen Design dengan menggunakan desain Nonequivalent Control Group Design, dengan jumlah populasi yaitu seluruh kelas X SMA Negeri 3 Takalar. Teknik pengambilan sampel dalam penelitian ini yaitu Simple Random Sampling yaitu kelas X1 sebagai kelas eksperimen dengan jumlah peserta didik sebanyak 36 orang dan kelas X5 sebagai kelas kontrol dengan jumlah peserta didik sebanyak 34 orang. Instrumen pengumpulan data yang digunakan adalah tes untuk mengetahui kemampuan berpikir kritis dan hasil belajar peserta didik dengan menggunakan model pembelajaran Discovery Learning dan Reception Learning. Data tersebut kemudian dianalisis dengan menggunakan analisis deskripsi dan inferensial. Analisis deskripsi untuk mengetahui deskripsi kemampuan berpikir kritis dan hasil belajar peserta didik dengan menggunakan model pembelajaran Discovery Learning dan Reception Learning serta analisis inferensial untuk mengetahui perbedaan yang signifikan dari rata-rata kemampuan berfikir kritis dan hasil belajar peserta didik yang menggunakan model pembelajaran Discovery Learning dan Reception Learning. Berdasarkan hasil penelitian untuk kemampuan berpikir kritis diperoleh nilai sign (0,000 0,05) maka H0 diterima artinya tidak terdapat perbedaan antara hasil belajar peserta didik yang diajar dengan model pembelajaran Discovery Learning dan Reception Learning. Penelitian ini diharapkan perlu dilakukan penelitian serupa dengan mengembangkan pendekatan dari variabel yang lain dan dapat dilakukan penelitian yang sama tetapi dengan materi yang lain

Sintesis dan Karakterisasi Carboxymethyl Cellulose Sodium (Na-CMC) dari Selulosa Eceng Gondok (Eichhornia crassipes) dengan Media Reaksi Etanol-Isobutanol

Eceng gondok adalah salah satu tumbuhan bahan serat alam yang memiliki kandungan selulosa yang cukup tinggi. Kadar selulosa yang tinggi dapat digunakan dalam pembuatan Karboksimetil Selulosa Sodium (Na-CMC). Tujuan dari penelitian ini adalah: untuk mengetahui karakteristik Karboksimetil Selulosa Sodium (Na-CMC) dari tanaman eceng gondok. dan mendapatkan variasi media reaksi terbaik dalam proses sintesis. Penelitian ini terdiri dari tiga tahap yaitu tahap pertama ekstraksi selulosa yang terdiri dari (dewaxing, dehemisellulose dan bleaching), tahap kedua yaitu tahap sintesis yang terdiri dari tahap pencampuran menggunakan media reaksi etanol-isobutanol (20:80, 50 : 50, 80:20). Tahap alkalisasi menggunakan NaOH 10% b / v, tahap karboksimetilasi menggunakan ClCH2COONa. Tahap ketiga adalah karakterisasi CMC yang terdiri dari uji organoleptik, sifat fisikokimia (pH, susut pengeringan sampel, viskositas dan derajat substitusi), uji kadar NaCl, uji kemurnian, analisis FT-IR. Berdasarkan hasil penelitian didapatkan bahwa karakteristik CMC mendekati karakteristik standar Na-CMC dengan campuran media reaksi etanol-isobutanol 20:80 (v / v) dengan nilai DS 0,8560, kemurnian 93,7463% level, pH 6,5 dan viskositas. 302 cP

Measurement Natural Radioactivity in Soil Samples from Important historical locals in Alnajaf Alashraf city, Iraq.

Al-Najaf Al-Ashraf city one of the most important ,oldest, historical and religious cities in Iraqi country which includes hundreds of holy shrines and historical mosques which over the built hundreds of years. The natural radiation of  forty two  samples of soil which collected randomly in June  2013 from different religious and historical places were  measured using  3"×3" Na(Tl) detection. The mean values activity concentrations of 238U, 232Th and 40K  was ( 23.59±4.37, 12.10±0.54 and 60.68±2.30) Bq kg-1  respectively , specific activity for all soil sample were in the worldwide average. The  average values of the Radium equivalent activity and  annual effective dose  were (22.455 Bq/kg and 25.375 μSv/y) less than the world average .The heist  external and internal hazard and gamma activity concentration index were (0.274 , 0.412 and 0.705) lower than unity

Momentum-Resolved Charge Excitations in a Prototype One Dimensional Mott Insulator

We report momentum resolved charge excitations in a one dimensional (1-D) Mott insulator studied using high resolution (~ 325 meV) inelastic x-ray scattering over the entire Brillouin zone for the first time. Excitations at the insulating gap edge are found to be highly dispersive (momentum dependent)compared to excitations observed in two dimensional Mott insulators. The observed dispersion in 1-D is consistent with charge excitations involving holons which is unique to spin-1/2 quantum chain systems. These results point to the potential utility of inelastic x-ray scattering in providing valuable information about electronic structure of strongly correlated insulators.Comment: 3 pages, 2 figures, Revised with minor change

Modeling Bangladesh's gross domestic product using regression approach

This study finds the factors that affect Bangladesh’s Gross Domestic Product (GDP) through regression approach. Stepwise and Ridge regression techniques have been applied to build the suitable regression model. Model adequacy also has been checked and multicollinearity problem is addressed for a plausible model using appropriate remedial measures for each of the model one after another that yields stepwise regression. The multicollinearity problem has also been tried to combat by ridge regression. Finally, the model which is adequate and free from multicollinearity problem after applying the ridge regression has been considered as the credible model for predicting the GDP of Bangladesh. The final model shows that the factors population, imports of goods and services, agriculture value added, manufacturing value added and labor force are positively affecting the GDP of Bangladesh

Non-generality of the Kadowaki-Woods ratio in correlated oxides

An explicit expression for the Kadowaki-Woods ratio in correlated metals is derived by invoking saturation of the (high-frequency) Fermi-liquid scattering rate at the Mott-Ioffe-Regel limit. Significant deviations observed in a number of oxides are quantitatively explained due to variations in carrier density, dimensionality, unit cell volume and the number of individual sheets in the Brillouin zone. A generic re-scaling of the original Kadowaki-Woods plot is also presented.Comment: 9 pages of text, 1 table, 2 figure

Laboratory diagnosis of urinary tract infections using diagnostics tests in adult patients

Background:The primary aim of this study was to evaluate laboratory diagnosis of urinary tract infection using diagnostics tests in adult patients.Methods:Among the diagnostic tests, urinalysis is useful mainly for excluding bacteriuria. For isolation of pathogenic bacteria semiquantitative culture techniques was used and biochemical tests were done to differentiate Gram +ve and Gram –ve bacteria.Results: The incidence of pathogenic infection caused by Escherichia coli accounts for 216 cases (60%) followed by Pseudomonas, Staphylococcus aureus and Klebsiella.Conclusion:Physicians should distinguish urinary tract infections caused by different organisms for an effective treatment and appropriate clinical information gives clues for better diagnostic evaluation and their susceptibility to antimicrobial agents as well addressing host factors that contribute to the occurrence of infection

Genetic regulation of diapause and associated traits in Chilo partellus (Swinhoe)

Diapause is an endocrine controlled arrested metabolic state to delay development or reproduction under unfavorable conditions. To gain an understanding of importance of diapause for ecological adaptation, it is important to study regulation of diapause in insects. We examined genetics of diapause in Chilo partellus by crossing the hibernating (HD), aestivating (AD), post-hibernating (PHD), post-aestivating (PAD), and nondiapause (ND) strains. Reciprocal crosses were also made to gain full understanding of diapause regulation and the maternal effects, if any. Data were recorded on fecundity, egg hatching, larval survival, diapause induction and termination, adult emergence, and morphometrics of larvae, pupae and adults in the parents (P1, P2), F1 hybrids, and the reciprocal crosses. Genetic analysis showed that AD strain is general combiner, which also improved egg hatching, larval survival, diapause termination, adult emergence and proportion of females in the progenies. Incidence of diapause was highest in HD × AD, whereas termination was greatest in PHD × AD. However, ND strain and its reciprocal crosses with other strains did not exhibit any noticeable developmental response associated with diapause. Specific combining ability analysis suggested that where PHD and AD strains exist together there will be likely reduction in diapause incidence, increased survival with greater fitness and faster multiplication of their progenies resulting in outbreak of C. partellus. Degree of dominance estimates revealed that diapause, developmental and morphometric traits in C. partellus are governed by over dominance gene effects, and mainly depend on parental diapause history

Phase transitions for PP-adic Potts model on the Cayley tree of order three

In the present paper, we study a phase transition problem for the $q$-state $p$-adic Potts model over the Cayley tree of order three. We consider a more general notion of $p$-adic Gibbs measure which depends on parameter \rho\in\bq_p. Such a measure is called {\it generalized $p$-adic quasi Gibbs measure}. When $\rho$ equals to $p$-adic exponent, then it coincides with the $p$-adic Gibbs measure. When $\rho=p$, then it coincides with $p$-adic quasi Gibbs measure. Therefore, we investigate two regimes with respect to the value of $|\rho|_p$. Namely, in the first regime, one takes $\rho=\exp_p(J)$ for some J\in\bq_p, in the second one $|\rho|_p<1$. In each regime, we first find conditions for the existence of generalized $p$-adic quasi Gibbs measures. Furthermore, in the first regime, we establish the existence of the phase transition under some conditions. In the second regime, when $|\r|_p,|q|_p\leq p^{-2}$ we prove the existence of a quasi phase transition. It turns out that if $|\r|_p<|q-1|_p^2<1$ and \sqrt{-3}\in\bq_p, then one finds the existence of the strong phase transition.Comment: 27 page