Fitting stochastic differential equations to molecular dynamics data

The thesis consists of three main parts. Firstly, a molecular dynamics and potential energy minimisation package that has been implemented is described in detail All potential and force interactions are described and tested successfully. Compound tests on minimal energies for clusters of water molecules, the radial distribution function for liquid argon and the equilibrium distribution for the dihedral angle in Butane under Langevin dynamics are performed and the presence of multiple time scales is noted for Butane as well as for a simplified protein model due to Grubmiiller and Tavan. Secondly, fitting stochastic differential equations (SDEs) to time series is studied. Initially, I consider the well-understood case of non-degenerate diffusions, where all components of the process are driven directly by Brownian motion. An SDE with constant diffusivity and trigonometric force expression is fitted to trajectories obtained from simulations of Butane by maximum likelihood methods and fitted diffusion and drift parameters depend strongly on the timescale considered. Hypoelliptic diffusion processes are considered next. Here, the unexpected failure of simple estimators necessitates the use of carefully chosen approximate likelihoods. For the case of only partial observations being available, a compound algorithm is designed and numerically seen to be asymptotically consistent. It is applied to the same Butane sample path and found to equilibrate, although the fitted SDE fails to reproduce the free energy landscape Thirdly, connections between maximum likelihood estimators (MLEs) and practitioners’ methods are investigated. Analytical links are found for reversible processes and for second order Langevin processes. In the case of ID processes, MLE and practitioners’ methods for the drift are found to yield estimators identical up to lower order terms even for finite times of observation

A systematic study of how molecular structure influences combustion and pyrolysis of novel renewable fuels in a diesel engine and high temperature reactor

Internal combustion technology has been employed as the primary mode of propulsion for transportation since the early 1900s, with continual improvements in efficiency ever since. Despite this, issues associated with the fuels combusted have caused a shift towards electrification, but this is not suitable for all applications and geographies. It is therefore necessary to seek sustainable fuels, in conventional engines, for the short to medium-term alleviation of CO2 emissions, fossil fuel usage and toxic pollution detrimental to air quality. The work presented uses a compression ignition (CI) engine to test a range of novel fuels, with proven sustainable sources, to detect their impact on exhaust emissions and combustion. Initially, a range of 2nd generation furanic biofuels were tested, in order to understand the effect of molecular structure on combustion. Saturated cyclic molecules with carbonyl side chains possessed strong ignitability, while alleviating particulate mass (PM); these molecular attributes are indicative of lactones. Lactones were therefore tested within the CI engine, with a subsequent investigation utilising a pyrolytic reactor to help understand soot formation from these fuels, since soot is initially formed from gaseous precursors. Gas Chromatography- Flame Ionisation Detection (GC-FID) analysis was used to detect soot-precursor concentrations in the breakdown of a lactone compared to other C10 fuels. It was determined that, despite minor differences in species present and differing precursor abundance, the pattern of pyrolysis products was similar for all fuels; ethylene was most prevalent, with lower levels of C3s (propene) and C4 (1,3-butadiene) gases. Preliminary investigations were undertaken to detect molecular breakdown of fuels in the engine itself, employing in-cylinder sampling to collect cylinder contents. Minor differences were noted between engine and reactor, likely due to air-derived oxygen in the engine. Finally, an investigation was conducted to gauge the impact of a hydrogen fuel carrier (ammonium hydroxide) on diesel combustion. This is less hazardous than ammonia itself, but the presence of water was shown to be detrimental to combustion efficiency at lower engine loads, while the fuel- bound nitrogen appeared to contribute to greater NOx emissions at comparable engine loads

Desarrollo de membranas polméricas de nano-fibras, micro-fibras y fibra hueca para la desalación por destilación en membrana

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Físicas, Departamento de Física Aplicada I (Termología), leída el 26-09-2014Depto. de Estructura de la Materia, Física Térmica y ElectrónicaFac. de Ciencias FísicasTRUEunpu

Economic growth, energy consumption and CO2 emissions in Sweden 1800-2000.

Large transformations of technologies have occurred in the Swedish economy during the last two centuries, resulting in higher income, better quality of products and changing composition of GDP. An agrarian society has given way to an industrial society and lately to a post-industrial phase. The energy supply systems have changed, from traditional energy carriers, such as firewood and muscle energy to modern carriers like coal, oil and electricity, with effects on CO2 emissions. Not only the energy supply has gone through fundamental changes, but also forest management, which affects the net emissions of CO2. The interrelations of growth, energy and CO2 are analyzed in this thesis, which uses standard calculations, relative price analyses and energy quality factors, to determine the relative effects of structural and technical changes, including changes in energy carrier composition to explain the long term delinking of energy consumption, CO2 emissions and economic growth that takes place. Technical change is the main reason of energy intensity decline. Total factor productivity gains, including improvements in technical energy efficiency, saves energy in relation to output. The most spectacular energy savings took place in the sectors transportation & communications and industry. Structural changes at the sector level tended to increase energy intensity between 1870 and 1970. No correlation was found between increasing energy quality and decreasing energy intensity, but energy quality may have had an impact on economic growth rates. The consumers’ surplus was exceptionally high during the interwar period and the three decades after the Second World War, and the total energy quality was outstanding during the latter period. The most rapid relative decline in energy intensity took place between 1970 and 2000. In this period structural changes at the sector level no longer worked to increase energy intensity and the new growth direction of the third industrial revolution saved energy in relation to output. The decrease in energy intensity after 1970 was not caused by changed patterns of foreign trade for Sweden, but by changed patterns of demand in Sweden as well as abroad. CO2 intensity, when only emissions from fossil fuels are counted, shows a pattern of either one long Environmental Kuznets’ Curve, interrupted by the Wars, or of three separate EKCs. The main determinants of this CO2 intensity are energy intensity and energy carrier composition, where the latter turned out to be most influential. The three costs involved in energy consumption, purchasing cost, handling costs and environmental costs are intended to play different roles at different income levels, with effects on energy carrier composition. The estimate of CO2 emissions and sequestration by Swedish forests showed a magnitude well in parity with emissions from fossil fuels. The aggregate CO2 emissions over the period 1800-2000 were not much altered, but the pattern of CO2 intensity was profoundly altered when forest emissions were included. Furthermore the analysis of forest management questioned the idea that firewood caused net CO2 emissions in a dynamic perspective, because the demand for thin timber dimensions stimulated a rational forestry

A DECISION SUPPORT SYSTEM FOR THE SPATIAL CONTROL OF INVASIVE BIOAGENTS

A Decision Support System (DSS) is developed and applied to the spatial control of invasive bioagents, exemplified in this study by the resident Canada goose species (Branta Canadensis) in the Anacostia River system of the District of Columbia. The DSS incorporates a model of goose movement that responds to resource distribution; a twocompartment Expert System (ES) that identifies the causes of goose congregation in hotspots (Diagnosis ES) and prescribes strategies for goose population control (Prescription ES); and a Geographic Information System (GIS) that stores, analyzes, and displays geographic data. The DSS runs on an HP xw8600 64-bit Workstation running Window XP Operating System. The mathematical model developed in this study simulates goose-resource dynamics using partial differential equations - solved numerically using the Finite Element Method (FEM). MATLAB software (v. 7.1) performed all simulations. ArcGIS software (v. 9.3) produced by Environmental Systems Research Institute (ESRI) was used to store and manipulate georeferenced data for mapping, image processing, data management, and hotspot analysis. The rule-based Expert Systems (ES) were implemented within the GIS via ModelBuilder, a modular and intuitive Graphical User Interface (GUI) of ArcGIS software. The Diagnosis ES was developed in three steps. The first step was to acquire knowledge about goose biology through a literature search and discussions with human experts. The second step was to formalize the knowledge acquired in step 1 in the form of logical sentences (IF-THEN statements) representing the goose invasion diagnosis rules. Finally, in the third step, the rules were translated into decision trees. The Prescription ES was developed by following the same steps as in the development of the Diagnosis ES, the major difference being that, in this case, knowledge was acquired relative to goose control strategies rather than overpopulation causes; and additionally, knowledge was formalized based on the Diagnosis and on other local factors. Results of the DSS application indicate that high accessibility to food and water resources is the most likely cause of the congregation of geese in the critical areas identified by the model. Other causes include high accessibility to breeding and nesting habitats, and supplementary, artificial food provided by people in urban areas. The DSS prescribed the application of chemical repellents at feeding sites as a goose control strategy (GCS) to reduce the quality of the food resources consumed by resident Canada geese, and therefore the densities of geese in the infested locations. Two other prescribed GCSs are egg destruction and harvest of breeding adult geese, both of which have direct impacts on the goose populations by reducing their densities at hotspots or slowing down their increase. Enclosing small wetlands with fencing and banning the feeding of geese in urban areas are other GCSs recommended by the ES. Model simulations predicted that these strategies would reduce goose densities at hotspots by over 90%. It is suggested that further research is needed to investigate the use of similar systems for the management of other invasive bioagents in ecologically similar environments

Condensed-Matter-Principia Based Information & Statistical Measures

This book summarizes the efforts of ten papers collected by the Special Issue "Condensed-Matter-Principia Based Information & Statistical Measures: From Classical to Quantum". It calls for papers which deal with condensed-matter systems, or their interdisciplinary analogs, for which well-defined classical–statistical vs. quantum information measures can be inferred while based on the entropy concept. The contents have mainly been rested upon objectives addressed by an international colloquium held on October 2019, in UTP Bydgoszcz, Poland (see http://zmpf.imif.utp.edu.pl/rci-jcs/rci-jcs-4/), with an emphasis placed on the achievements of Professor Gerard Czajkowski, who commenced his research activity with open diffusion–reaction systems under the supervision of Roman S. Ingarden (Toruń), a father of Polish synergetics, and original thermodynamic approaches to self-organization. The active cooperation of Professor Czajkowski, mainly with German physicists (Friedrich Schloegl, Aachen; Werner Ebeling, Berlin), ought to be highlighted. In light of this, a development of his research, as it has moved from statistical thermodynamics to solid state theory, pursued in terms of nonlinear solid-state optics (Franco Bassani, Pisa), and culminated very recently with large quasiparticles termed Rydberg excitons, and their coherent interactions with light, is worth delineating

Mathematical Modeling and Simulation of the Photosynthesis in a Plant Leaf Cell

Photosynthesis is a very important process in plants which occurs in chloro- plasts. Plants use photon energy to oxidize water molecule, release oxygen, and convert carbon dioxide to sugar molecule. The process of photosynthe- sis contains two main parts: light dependent reactions and light independent reactions. A mathematical model, which describes the diffusion-transport and related chemical reactions in a multi-component flow in a single C3 plant leaf cell, is constructed. A sub-domain of a leaf cell is considered containing multiple organelles: chloroplast, mitochondria, vacuole, cytoplasm, and peroxisome. A typical distribution of a finite number of these organelles inside a cell is considered. The cell domain is decomposed in 5 sub-domains, separated by fixed interfaces. The interacting chemical reactions induced by light, of the Calvin cycle, the starch synthesis, sugar synthesis, respiration and photores- piration are investigated. A sensitivity analysis was performed, the results allows a reduction of the complex system. A system of partial differential equations, which describes the diffusion-transport and also related chemical reactions is formulated and simulated using the software Gascoigne. For the reduced system, the resulting flow of substances is analyzed

Indian IT industry: a performance analysis and a model for possible adoption

India's software and services exports have been rising rapidly. The annual growth rate ranges between 20 -22% in IT services and nearly 55 % in IT-enabled services (ITES), such as call centres, Business Process Outsourcing ( BPO) and other administrative support operations. Together they are predicted to grow at 25% pa till 2010.The IT industry is highly export oriented and the exporters are predominantly Indian. The Indian BPOs (ITES) are moving up the value chain, handling high end data for airline information, insurance, banking sector and mortgage companies, enterprise resource planning, among others. Some of the companies have already moved into significantly higher value added segments such as mission- critical applications, development and support, product design, HR Management, knowledge process outsourcing for pharmaceutical companies and large complex projects. Software exports make up 20 % of India's total export revenue in 2003-04, up from 4.9 % in 1997.This figure is expected to go up to 44% of annual exports by 2010. Though India accounts for just about 3 % of the world market for information technology services, this sector has been growing at a scorching pace, helped by a large pool of English-speaking workers, nearly 4 million engineers and the increasing tribe of tech-savvy entrepreneurs in the country. The Information Technology industry currently accounts for almost 4.8 % of India's GDP. It will account for 7 % of India's GDP by 2010. Software and IT enabled services have emerged as a niche sector for India. This was one of the fastest growing sectors in the last decade with a compound annual growth rate exceeding 50 per cent. Software service exports increased from US $0.50 million in 1990 to$5.9 billion in 2000-01 to 23.6 billion dollars in 2005-06 recording a 34% growth. A compound annual growth of over 25% per annum is expected over the next 5 years even on the expanding base. The impact on the economy of projected software and IT enabled service exports of 60 billion by 2010 is likely to be profound. One manifestation is that India notched up a current account surplus in 2001-02, for the first time in 24 years. India further needs an open environment under GATS to promote exports of services through outsourcing and off-shoring . The present study examines the growth performance of India’s IT industries, with particular attention paid to the role of policy in this process. The study recognizes that emergence of a strong Indian IT industry happened due to concerted efforts on the part of the Government, particularly since 1980s, and host of other factors like Government-Diaspora relationships, private initiatives, emergence of software technology parks, clustering and public private partnerships. In this study we further look at the major parameters of the Indian IT and ICT industry in global context and give justification for including the main factors responsible for the IT boom in India. The study has looked into the past and present trends of the Indian IT industry and has considered further needs of IT sector to act as a catalyst of growth and development. The study has examined whether the Indian IT growth does have enough lessons for other countries to model their IT policy which may help them to shape their IT industry as driver of growth and development. IT firms were actually required to export software in the early days of the industry. This arose in the context of a shortage of foreign exchange in India in the 1970s and early 1980s.Software firms that needed imported inputs were required to earn foreign exchange themselves through export of software. This enabled them to get an idea of global markets very early. Besides formulating the national vision to promote software industry in India in the early 1980s by the government, there were deliberate attempt by the companies to promote software production like compilers, device drivers and operating system to cater to the domestic hardware sector. The high tariffs for the hardware sector had meant that the production of domestic hardware segment (including PCs which were introduced in the same period) had to be sustained requiring necessary software’s like operating system and drivers. Subsequently by mid 1980s, software started coming up unbundled with the hardware. This further gave fillip to the software industry and exports. The 1990s and early 2000 saw the rise of Software Technology Parks and formation of the Ministry of Information Technology, respectively. Despite liberalization of the 1991, the software industry flourished signifying the inherent strength that it developed due to benign and enabling environment provided over a period of time and also the fact that the 1990s saw the dramatic decline in telecommunication costs (government explicit intervention) and the commercialization of the internet along with the Y2K “problem”. The Data Envelopment Analysis (DEA) model is used to work out technical efficiency of Information and Communication Technology ( ICT) Industry in host of countries which are front runners as far as ICT is concerned. India lags behind the most as far as ICT (not IT) is concerned. However, information and Communication technology industry has brought revolution in India because it has reduced intermediation in business and society, provided solutions across sectors and is increasingly becoming an important tool for national development. DEA is also applied to benchmark the performance of the 92 Indian Software Companies for 2005- 2006. The impact of various determinants on technical efficiency of the Indian Software companies is worked out using tobit regression. The impact of the explanatory factors on net exports of 92 software firms in 2005-06 is also worked out using simple regression exercise. The study also works out technical efficiency of 36 telecommunication firms in India and examines the determinants for new technology adoption by such industries. The study uses a Malmquist index to estimate total factor productivity changes decomposed into efficiency change( catching up to the frontier technology) and technical change( movement of the frontier) for the common software firms existing between 1996 and 2006 E-government is the application of Information and Communication Technologies (ICT) by government agencies. Its use promises to enhance the effectiveness and efficiency of government and alter its relationship with the public. The study outlines E-Governance models for effective governance and for higher agricultural growth and development. E-Commerce primarily refers to buying, selling, marketing and servicing of products or services over internet and other computer networks. E-Commerce in India is just taking off with the advent of Railway and Online Air bookings and Net banking. The business is likely to grow to Rs 2300 crore by 2007 .Electronic commerce allows efficient interactions among customer, suppliers and development partners cutting down on transaction time and reducing the costs of doing business. The role of government is to facilitate the development of E-Commerce. For promoting South-South Cooperation and making it meaningful, the governments of the member countries need to pool resources and capabilities in R&D and human resource development for harnessing the fruits of Information and Communicating technologies. The study spells out in detail a number of examples where ICT has been used by rural communities for their benefit and for policy and development goals of the government in general. Web based software development and software product development (like device drivers) is necessary for providing complete business and consumer oriented solutions. These are also areas of interest for the Indian IT entrepreneurs to work upon in times to come. India’s relatively unsafe e-security environment is costing the BPO/ITES industry. The new IT Act (2000) needs to crucially define cyber harassment, phishing and cyber stalking to take care of cyber crimes in India. With the Indian IT/BPO exports to reach 60 billion by 2010, such companies need to invest in upgrading security measures for sustaining competitiveness. Organizations are not obliged under the IT Act to implement data security measures to protect consumers and clients. All this makes it obvious that qualitative progress cannot be made without enacting comprehensive data protection legislation. The Information and communication technologies (ICT) indicators of India are 13 million PCs, 40 million internet users- country with the fifth-largest number of Internet users,143 million mobile phones and 60 million subscribers for fixed lines in 2006. These are modest figures in comparison with the ICT penetration indicators achieved by the front runners like Taiwan, South Korea, Japan, UK, US, Nordic countries in Europe, among others (see the text for our strength and weaknesses in the ICT infrastructure in comparison with some other front runner countries). India’s Strengths lies in its availability of pool of scientists and engineers and quality of maths and science education along with quality of business schools. We are also ranked quite high in terms of cluster development, foreign technology licensing and Government prioritization of ICT. The weaknesses are the telecommunication infrastructure and speed of new business registration. However, Information and communication technologies(ICT) has brought about revolution in India particularly since 1990s .This is because it has reduced intermediation in business and society, reduced mobile and fixed telephony rates(because of concerted policy interventions by the government), provided solutions across sectors, provided both CDMA and GSM mobile technologies (and now Wi-Max technologies for internet access at different public places using PC), re-organizing firm level behavior, empowering individuals by providing them with more information and is increasingly becoming an important tool for national and rural development through E-governance, E-Banking and E- Commerce programmes. In addition, the success of the Information Technology industry in India is intertwined with information and communication technologies as most of the Information technology enabled services use such technologies for providing their services. The quantitative results of the paper answers the following- what orientations in inputs should be done by inefficient software and telecommunication firms and ICT Industry in general to reach the ‘ best practice frontier’( and have operational excellence), examines the relationship between technical efficiency and net exports of software firms along with the impact of host of explanatory factors like size of firms in terms of sales and total cost, among others on technical efficiency and net exports for cross section of software firms using tobit analysis, gives some reasons for relatively low ICT penetration in India and what can be done to transform India’s relatively good ICT readiness and ICT environment into higher ICT usage, answers why telecommunication firms are adopting new technologies and estimates total factor productivity changes in software firms which can be further used to model wage and price estimation of products and services offered by software firms over time. The paper confirms the improvements in productivity, efficiency change and technical change of the Indian Software industry from 1996 to 2006. Synopsis Chapter Wise Chapter one describes the major parameters of the Indian Information Technology (IT) Industry in India today and in the immediate past. The chapter further analyzes the reason for the ‘boom’ in the Indian IT sector. We also outline an electronic governance Model which can become a tool for effective governance. DEA is applied to benchmark the performance of the 92 Indian Software Companies for 2005- 2006. The impact of various determinants on technical efficiency of the Indian Software companies is worked out using tobit regression. The impact of the explanatory factors on net exports of 92 software firms in 2005-06 is also worked out using simple regression exercise. . Further this chapter uses a Malmquist index to estimate total factor productivity changes decomposed into efficiency change and technical change for the common software firms existing between 1996 and 2006. Chapter two gives an account of the position of the Indian Information Technology (IT) Industry and the Indian Information and Communication Technology (ICT) Industry in the global context and analyzes the strengths and weaknesses of ICT Infrastructure across some countries. Technical Efficiency of the Indian ICT sector is worked out using the mathematical model of Data Envelopment Analysis. The study also works out technical efficiency of 36 telecommunication firms in India and examines the determinants for new technology adoption by such industries. Chapter Three describes why and how the Indian IT industry can act as a catalyst of growth and development. An account of an effective electronic governance model for Agriculture Sector is also given. Chapter Four looks at the past of IT industry since 1960s keeping policy in mind. This chapter also outlines an export success model . Such models can be emulated by other countries. Chapter five describes the hurdles and constraints faced by the India IT industry and give an account of the policies and strategies which can be adopted to address the hurdles and concerns of the ICT sector. The last Chapter gives the conclusions, suggestions and policy advice for making IT as a tool for addressing some core inadequacies in the system like poverty, inequality, healthcare and education, among others.IT; ICT; ITPOLICY; OUTSOURCING; DEA ANALYSIS; TECHNICAL EFFICIENCY; TOBIT; NETEXPORTS; MALMQUIST INDEX; TOTAL FACTOR PRODUCTIVITY CHANGE; EFFICIENCY CHANGE; TECHNICAL CHANGE