Codified methods to analyse the failures of water pipelines: A Review

Pipelines used for the transportation of water and other services are very important lifelines in modern society. The important role that they play in our present economy is reflected by thousands of kilometres of service laid in urban centres worldwide. As many of these pipelines have been laid few decades earlier, in most cases, their condition has been deteriorated mainly by electro-chemical and (or) micro-biological corrosion. There are several codes of practice available at present to analyse the condition of such deteriorated pipes. This paper identifies and reviews all such relevant standards applicable to corroded water mains with the use of some case studies. Three dimensional finite element analyses are also conducted to investigate the capabilities of simulating the failures of corroded pipelines and thus to ascertain the validity of codified methods. By careful assessment of the current codes of practice in use, it is possible to understand where these codes are lacking and which codes can rightly predict the realistic water pipe failures observed in the past

Dynamical order, disorder and propagating defects in homogeneous system of relaxation oscillators

Reaction-diffusion (RD) mechanisms in chemical and biological systems can yield a variety of patterns that may be functionally important. We show that diffusive coupling through the inactivating component in a generic model of coupled relaxation oscillators give rise to a wide range of spatio-temporal phenomena. Apart from analytically explaining the genesis of anti-phase synchronization and spatially patterned oscillatory death regimes in the model system, we report the existence of a chimera state, characterized by spatial co-occurrence of patches with distinct dynamics. We also observe propagating phase defects in both one- and two-dimensional media resembling persistent structures in cellular automata, whose interactions may be used for computation in RD systems.Comment: 6 pages, 4 figure

Physisorption of Nucleobases on Graphene

We report the results of our first-principles investigation on the interaction of the nucleobases adenine (A), cytosine (C), guanine (G), thymine (T), and uracil (U) with graphene, carried out within the density functional theory framework, with additional calculations utilizing Hartree--Fock plus second-order Moeller-Plesset perturbation theory. The calculated binding energy of the nucleobases shows the following hierarchy: G > T ~ C ~ A > U, with the equilibrium configuration being very similar for all five of them. Our results clearly demonstrate that the nucleobases exhibit significantly different interaction strengths when physisorbed on graphene. The stabilizing factor in the interaction between the base molecule and graphene sheet is dominated by the molecular polarizability that allows a weakly attractive dispersion force to be induced between them. The present study represents a significant step towards a first-principles understanding of how the base sequence of DNA can affect its interaction with carbon nanotubes, as observed experimentally.Comment: 7 pages, 3 figure

Search for gamma rays of energy 10(15) eV from Cygnus X-3

Finite flux of excess radiation of energy 10 to the 15th power has been reported by two groups from the direction of Cygnus X-3, with the characteristic periodicity of 4.8 hrs. Samorski and Stamm find that the muon content of the showers generated by this excess radiation is about 77% of that in normal cosmic ray showers, whereas the expectation for gamma ray showers is less than 10%. It is thus difficult to understand the nature of the radiation arriving from the direction of Cygnus X-3. Samorski and Stamm measured the muon densities close to the core (approx. 10 m), where contamination due to other components is severe. Even though this does not explain the high ratio of muon densities, measurements should be carried out away from the core to establish the nature of the radiation. In order to establish the signal from Cygnus X-3 and its muon content with better statistical significance, an extensive air shower array, specifically designed for this purpose was operated at Kolar Gold Fields (longitude: 78 deg .3 E; latitude: + 12 deg .95; atmospheric depth: 920 q/square centimeters) since September, 1984. The details of the array and the accuracy of arrival direction measurements are discussed

Clinical prognostication of out-of-hospital cardiac arrest: insight from a prospective observational study using the shockable, witnessed, age and pH score

Background: Cardiac arrest remains a leading cause of mortality and morbidity worldwide. Though there are many prognostic tools, the importance of predicting prognosis of out of hospital cardiac arrest in the emergency department (ED) using SWAP (Shockable, witnessed, age and pH) score has not been studied extensively. Methods: We conducted a hospital-based prospective observational study in Kerala, India, focusing on patients who arrived at the ED after experiencing out-of-hospital cardiac arrest (OHCA). For patients who met the inclusion criteria, (all patients who came to ED with OHCA with age more than 18 years) we calculated the SWAP score using historical information and venous blood gas sample analysis. Patients who achieved return of spontaneous circulation (ROSC) were closely monitored, and post-cardiac arrest care was initiated. Patients who achieved sustained ROSC were admitted, and at time of discharge, follow-up was conducted using cerebral performance category (CPC) score. Results: The SWAP score was computed for patients who experienced OHCA. The analysis revealed that patients with favorable outcomes (CPC 1 and 2) had an average SWAP score of 1, while patients with unfavorable outcomes (CPC 3, 4, 5) had an average SWAP score of 1.55. Among the total of 116 patients, 7 individuals (6.03%) survived with positive neurological outcomes (CPC 1 and 2), while 109 patients (93.96%) experienced poor neurological outcomes (CPC 3, 4, 5, and mortality). Conclusions: Patients who had a high SWAP score had a reduced likelihood of survival and sustained ROSC. Conversely, patients with a SWAP score below 2 had a higher probability of experiencing a ROSC and surviving

An electron paramagnetic resonance study of Pr_{0.6}Ca_{0.4}MnO_{3} across the charge ordering transition

We report the first electron paramagnetic resonance studies of single crystals and powders of Pr_{0.6}Ca_{0.4}MnO_{3} in the 300-4.2 K range, covering the charge ordering transition at ~ 240 K and antiferromagnetic transition (T_N) at ~ 170 K. The asymmetry parameter for the Dysonian single crystal spectra shows anomalous increase at T_{co}. Below T_{co} the g-value increases continuously, suggesting a gradual strengthening of orbital ordering. The linewidth undergoes a sudden increase at T_{co} and continues to increase down to T_N. The intensity increases as the temperature is decreased till T_{co} due to the renormalization of magnetic susceptibility arising from the build up of ferromagnetic correlations. The value of the exchange constant, J, is estimated to be 154 K.Comment: Uses Revtex3.

Trade competitiveness and export performance of Indian cardamom

India is one of the major producers and consumer of cardamom. The export performance of cardamom has witnessed several changes over the past few decades. This paper analyses the trends and performance of cardamom commodity from India. Using secondary data from the Spices Board and the Ministry of Commerce along with international trade data from the United Nations International Trade Statistics Database, the trend in the domestic production and export markets is clearly drawn out. The changes in Revealed Comparative Advantage in cardamom exports over the years is used to study the level and changes in the export competitiveness of the commodity. The study identifies a revival in export competiveness in the recent years along with an increase in the share of global cardamom exports. The highly concentrated production of cardamom, the preference for Indian cardamom in Middle East economies and the revival of export competitiveness can benefit the Indian cardamom producers. The study argues for strengthening research investments in cardamom for sustaining and enhancing the benefits from cardamom exports from the country