Journey Towards Risk Based Process Safety

PresentationOver the years, there have been many technological advancements in the industry and a hugegrowth in terms of operating capabilities. Being among the fastest growing organisations, managing enterprise wide risk effectively is a very crucial success factor. It is also recognized that identification and assessment of process safety risks is the cornerstone to sustain growth and to ensure worker and public safety. In the area of process safety, there are well-defined and established risk analysis techniques ranging from very simple to quite rigorous ones depending on criticality and complexity of application. However selection and application of appropriate technique is understood by a small section of workforce and often left to mere judgement of analysts. Hence they are often mistaken for mere theory and may not be thought of as realistic. It is onerous task upon risk analysts to translate these analyses in such a way that these are projected in an effective way that connects these results with the impact to the business outcomes. For Reliance, starting with Hazop studies, moving on to elaborate Process Hazard Analysis, LOPA and QRA has been a gradual journey. While traditional methodologies are applied throughout, there is a certain level of customisation done as per organizational needs. All such efforts are aimed at continuous improvement in the way risks are identified and also improve the quality of analysis. Group wide requirements and supporting ground rules have been defined to effectively utilize these methodologies in a consistent manner across various locations. Customisation also means applying more rigour in the analyses with less subjectivity, pre-defining criteria for choosing scope for quantitative analyses or the way risks are estimated. These ground rules were developed for both qualitative and quantitative techniques like What-if/ Hazop, Consequence analysis, LOPA, MAR/ QRA. However these ground rules are aligned to current group strategy and can potentially undergo review in future and any required changes made. The paper discusses the evolution process in the area of Risk Assessment, challenges faced in realizing the actual benefits out of the assessments and how certain alterations in assessment methodology have helped in continual improvement of process safety and risk management

Liver disease detection using machine learning techniques

Around a million deaths occur due to liver diseases globally. There are several traditional methods to diagnose liver diseases, but they are expensive. Early prediction of liver disease would benefit all individuals prone to liver diseases by providing early treatment. As technology is growing in health care, machine learning significantly affects health care for predicting conditions at early stages. This study finds how accurate machine learning is in predicting liver disease. This present study introduces the liver disease prediction (LDP) method in predicting liver disease that can be utilised by health professionals, stakeholders, students and researchers. Five algorithms, namely Support Vector Machine (SVM), Naïve Bayes, K-Nearest Neighbors (K-NN), Linear Discriminant Analysis (LDA), and Classification and Regression Trees (CART), are selected. The accuracy is compared to uncover the best classification method for predicting liver disease using R and Python. From the results, K-NN obtains the best accuracy with 91.7%, and the autoencoder network achieved 92.1% accuracy, which is above the acceptable level of accuracy and can be considered for liver disease prediction.tru

Transient dynamics of a superconducting nonlinear oscillator

We investigate the transient dynamics of a lumped-element oscillator based on a dc superconducting quantum interference device (SQUID). The SQUID is shunted with a capacitor forming a nonlinear oscillator with resonance frequency in the range of several GHz. The resonance frequency is varied by tuning the Josephson inductance of the SQUID with on-chip flux lines. We report measurements of decaying oscillations in the time domain following a brief excitation with a microwave pulse. The nonlinearity of the SQUID oscillator is probed by observing the ringdown response for different excitation amplitudes while the SQUID potential is varied by adjusting the flux bias. Simulations are performed on a model circuit by numerically solving the corresponding Langevin equations incorporating the SQUID potential at the experimental temperature and using parameters obtained from separate measurements characterizing the SQUID oscillator. Simulations are in good agreement with the experimental observations of the ringdowns as a function of applied magnetic flux and pulse amplitude. We observe a crossover between the occurrence of ringdowns close to resonance and adiabatic following at larger detuning from the resonance. We also discuss the occurrence of phase jumps at large amplitude drive. Finally, we briefly outline prospects for a readout scheme for superconducting flux qubits based on the discrimination between ringdown signals for different levels of magnetic flux coupled to the SQUID.Comment: 15 pages, 9 figure

Microstrip superconducting quantum interference device amplifiers with submicron Josephson junctions: enhanced gain at gigahertz frequencies

We present measurements of an amplifier based on a dc superconducting quantum interference device (SQUID) with submicron Al-AlOx-Al Josephson junctions. The small junction size reduces their self-capacitance and allows for the use of relatively large resistive shunts while maintaining nonhysteretic operation. This leads to an enhancement of the SQUID transfer function compared to SQUIDs with micron-scale junctions. The device layout is modified from that of a conventional SQUID to allow for coupling signals into the amplifier with a substantial mutual inductance for a relatively short microstrip coil. Measurements at 310 mK exhibit gain of 32 dB at 1.55 GHz.Comment: Version with high resolution figures at: http://physics.syr.edu/~bplourde/bltp-publications.ht

Ultrasound attenuation and a P-B-T phase diagram of superfluid 3He in 98% aerogel

Longitudinal sound attenuation measurements in superfluid 3He in 98% aerogel were conducted at pressures between 14 and 33 bar and in magnetic fields up to 4.44 kG. The temperature dependence of the ultrasound attenuation in the A-like phase was determined for the entire superfluid region exploiting the field induced meta-stable A-like phase at the highest field. In the lower field, the A-B transition in aerogel was identified by a smooth jump in attenuation on both cooling and warming. Based on the transitions observed on warming, a phase diagram as a function of pressure (P), temperature (T) and magnetic field (B) is constructed. We find that the A-B phase boundary in aerogel recedes in a drastically different manner than in bulk in response to an increasing magnetic field. The implications of the observed phase diagram are discussed.Comment: 9 pages, 13 figures, accepted to PR

Integrating nanoionics concepts in micro solid oxide fuel cells

[spa] La Nanoiónica se ha convertido en un campo cada vez más prometedor para el futuro desarrollo de dispositivos avanzados de conversión y almacenamiento de energía, tales como baterías, pilas de combustible y supercondensadores. En particular, los materiales nanoestructurados ofrecen propiedades únicas o combinaciones de propiedades en electrodos y electrolitos en una gama de dispositivos de energía. Sin embargo, la mejora de las propiedades de transporte de masa a nivel nano, a menudo se ha encontrado que son difíciles de implementar en nonoestructuras. En esta tesis, se investigó el transporte de iones oxígeno en cátodos tipo perovskita-conductor mixto iónico y electrónico (MIEC) de capa delgada (grosor < 200nm) con una estructura nonoestructurada, con el objetivo de correlacionar el transporte de iones oxígeno con la estructura del film a nivel de grano interior y límite de grano. El trabajo desarrollado en esta tesis se ha dividido en seis partes. El primer capítulo, introduce los conceptos básicos de las pilas de combustible de óxido sólido, la importancia de los cátodos de película delgada y el concepto de nanoiónica. El segundo capítulo explica el principio y el funcionamiento de todas las técnicas experimentales empleadas en esta tesis para la caracterización microestructural y funcional de los cátodos de película delgada. Los siguientes capítulos contienen el trabajo principal de la tesis. Las condiciones de deposición y estudios de optimización microestructural realizados mediante PLD para fabricar cátodos de película delgada se compilan en el capítulo tres. Las propiedades de transporte de iones de oxígeno del La0.8Sr0.2MnO3+δ (LSM) de películas delgadas se estudian en el capítulo cuatro. Además, en el capítulo cinco se presenta una nueva metodología de proyección de materiales, para celdas de combustible de óxido sólido (SOFC). La metodología se basa en una deposición combinatoria de La0.8Sr0.2Mn1-xCoxO3±δ (LSMC) por PLD en una oblea de silicio de 4 pulgadas que permite la generación de un diagrama binario completo de composiciones, incluso para óxidos complejos. El capítulo seis se dedica a los estudios funcionales del sistema binario LSMC La técnica de intercambio de isotopos en perfiles profundos combinada con la espectroscopia iónica de masas (IEDP-SIMS) se empleó en el rango de temperatura de 500°C a 800°C para la evaluación de las propiedades de transporte de masa de oxígeno del LSM y el sistema binario LSMC. Además, las propiedades de transporte de masa de oxígeno del LSM se estudió mediante Espectroscopia de Impedancia Electroquímica (EIS).[eng] Fuel cells are one of the promising technology at present to meet the growing demand of clean energy and technology. Among the different varieties of fuel cells, Solid Oxide Fuel Cell (SOFC) research is advancing towards the device miniaturization (called “micro-SOFC” with thin film components) with the operation temperature in the range ≈ 500°C to 700°C for portable device application. In SOFC components, cathode causes major polarization loss due to the sluggishness of oxygen reduction reaction (ORR) at low operating temperature that would affect the device efficiency. To rectify this there are various groups working towards the enhancement of cathode functionality at low operating temperature. Generally, the functionality of cathode can be enhanced by two ways i) improving the intrinsic properties of existing cathode materials by making modifications in the cathode microstructure ii) search for the new cathode materials. The thin film cathodes studied in this thesis are La0.8Sr0.2MnO3+δ (LSM), La0.8Sr0.2CoO3-δ (LSC) and La0.8Sr0.2Mn1-xCoxO3±δ (LSMC; from x=0 to 1) a pseudo-binary system, which are Mixed Ionic Electronic Conductors (MIEC) conduct both ions and electrons. The aforementioned two ways are followed in this thesis to enhance the cathode functionality by implementing nanoionics concept. The behavior of ionic conduction in nano-regime (<100nm) is totally different than bulk and the study of such ionic transport in nanoscale is the field of nanoionics. Especially, the interfaces such as space-charge layer and grain boundaries act as a highway for fast oxygen ion conduction that can enhance the overall charge transport in the nanostructures. In this thesis, oxygen mass transport properties are studied in cathodes in thin film form by making modifications in the thin film nanostructure in order to observe and enhance the charge transport along the interface of grain boundaries as well as to understand the fast ionic transport in such interfaces. Generally, the thin film nanostructure offered by Pulsed Laser Deposition (PLD) exhibit columnar grains that can act as a highway for ionic conduction and suitable for the proposed work. Therefore PLD is used as a tool to study the ionic transport in the interfaces. Further, LSM/LSC multilayer deposition studies are conducted in PLD to find out the optimum thickness for the fabrication of a combinatorial LSMC pseudo-binary system without any parasitic phases. Among the cathode materials studied in this thesis, LSM is a classical and well-studied cathode material. The functional properties i.e. oxygen mass transport properties (oxygen self-diffusion and surface exchange coefficients, D^*and k^*, respectively) of LSM thin film cathodes are studied by Isotope Exchange depth Profiling using Secondary ion Mass Spectroscopy (IEDP-SIMS) and Electrochemical Impedance Spectroscopy (EIS) techniques in the temperature range 500°C to 700°C. In the study on LSMC pseudo-binary, a novel (new) methodology is presented for the screening of materials for SOFC application. The methodology is based on a combinatorial deposition of thin films by PLD on 4-inch silicon wafers, further it is possible to predict the thickness and compositional map of LSMC binary using this methodology. The proposed methodology can be extended for generating full range binary and ternary diagrams of compositions even for very complex oxides (due to an excellent transfer of the stoichiometry). IEDP-SIMS is carried out for evaluating oxygen mass transport properties of LSMC system in the compositions with cobalt content x ≈ 0.04 to 0.85 in the temperature range 600°C to 800°C. This thesis is divided into six chapters and a short summary to each chapter is given below including appendix. Chapter 1: An introduction to the scope of the thesis. Chapter 2: An introduction to the experimental method employed in this thesis. Chapter 3: Parent materials (LSM and LSC) microstructural optimization in PLD. Chapter 4: Oxygen ion transport study in LSM thin film cathodes. Chapter 5: Fabrication and microstructural characterization of LSMC thin film pseudo-binary system. Chapter 6: Oxygen ion transport study in LSMC thin film system. Appendix A: Introduction to Two-slab model. Appendix B: Fabrication of LSM-LSC-LSF pseudo-ternary syste

Chronic rheumatic heart disease and congenital heart disease complicating pregnancy: a study of the cardiac events, the maternal and perinatal outcome during 2011-2013 at tertiary care centre

Background: Objective of this study was to assess the prevalence of chronic rheumatic heart disease and congenital heart disease complicating pregnancy, study the maternal and perinatal outcome, and indications for termination of pregnancy.Methods: Preconception counseling, antenatal care by pregnancy heart team as per protocol. One 2nd gravida (G2A1) with 26 weeks gestation, underwent mitral valve replacement during 26th week gestation i/v/o infective endocarditis associated with severe mitral regurgitation.Results: Authors had CRHD: CHD = 29:21, out of 50 cases, the ratio was 1.3:1 in this study. Atrial septal defect (ASD) was the predominant lesion in this study -29% ASD alone and 9% associated with pulmonary artery hypertension. Eisenmenger's syndrome, was associated with ASD in three and VSD in two. Corrected lesions were 24%. In the rheumatic heart disease, mitral stenosis was the predominant lesion and PBMV was done in four (13.7%) cases. In CRHD cases, surgically corrected by prosthetic heart valve were -11 (37.9%). In CRHD total corrected cases, by prosthetic heart valve and percutaneous balloon mitral valvotomy (PBMV) account for 51.7%. One patient had PBMV procedure during 5th month of present pregnancy i/v/o severe mitral stenosis with mitral valve area -0.8 cm2 and another patient had PBMV during her first pregnancy. In this study 42% were in NYHA class I. 14% were in NYHA class IV. CHF was seen in 10%. Termination of pregnancy was necessary in 6 with CHD and 5 with CRHD. There were 39 deliveries with one set of twins. All the babies were alive. Maternal mortality was confirmed in one case with Eisenmenger’s syndrome + HELLP syndrome. Live birth rate was higher in cases with NYHA class I/II than in those with NYHA class III/IV (82.8% versus 66.60%).Conclusions: Management by a pregnancy heart team as per guidelines would reduce mortality

Cognitive Radio Networks: Realistic or Not?

A large volume of research has been conducted in the cognitive radio (CR) area the last decade. However, the deployment of a commercial CR network is yet to emerge. A large portion of the existing literature does not build on real world scenarios, hence, neglecting various important interactions of the research with commercial telecommunication networks. For instance, a lot of attention has been paid to spectrum sensing as the front line functionality that needs to be completed in an efficient and accurate manner to enable an opportunistic CR network architecture. This is necessary to detect the existence of spectrum holes without which no other procedure can be fulfilled. However, simply sensing (cooperatively or not) the energy received from a primary transmitter cannot enable correct dynamic spectrum access. For example, the low strength of a primary transmitter's signal does not assure that there will be no interference to a nearby primary receiver. In addition, the presence of a primary transmitter's signal does not mean that CR network users cannot access the spectrum since there might not be any primary receiver in the vicinity. Despite the existing elegant and clever solutions to the DSA problem no robust, implementable scheme has emerged. In this paper, we challenge the basic premises of the proposed schemes. We further argue that addressing the technical challenges we face in deploying robust CR networks can only be achieved if we radically change the way we design their basic functionalities. In support of our argument, we present a set of real-world scenarios, inspired by realistic settings in commercial telecommunications networks, focusing on spectrum sensing as a basic and critical functionality in the deployment of CRs. We use these scenarios to show why existing DSA paradigms are not amenable to realistic deployment in complex wireless environments.Comment: Work in progres