Modelling and Forecasting the Unit Cost of Electricity Generated by Fossil Fuel Power Plants in Sri Lanka

The national grid system which is evolved to deliver electricity must be always kept in balance so that it must have a sufficient production to meet the demand of electricity while minimizing the generation cost. This study presents a statistical time series model for forecasting the Unit Cost (UC) of generation of electricity in fossil fuel power plants by using two approaches namely Auto Regressive Integrated Moving Average (ARIMA) and time series regression. This is conducted as a case study in a Diesel/Heavy Fuel Oil (HFO) power plant in Sri Lanka which consists of two sub stations. ARIMA (1,1,0) and ARIMA (2,1,2) were selected as the best models with the lowest Akaike Information Criterion (AIC) under the ARIMA model approach while two dynamic regression models with coefficient of determination (R2) value 0.55 were selected under time series regression approach for Station 1 and Station 2 respectively. The regression model was identified as the best forecasting method for two stations with the minimum Mean Absolute Error (MAE) and Root Mean Square Error (RMSE). The forecasts of the future generation cost of electricity are extensively helpful for the national grid system for financial and capacity planning, fuel management and operational planning

Anti-lipopolysaccharide factors in the American lobster Homarus americanus: Molecular characterization and transcriptional response to Vibrio fluvialis challenge

Two partial mRNA sequences predicted to encode anti-lipopolysaccharide factors (ALFs) were identified among expressed sequence tags generated from the American lobster Homarus americanus and complete cDNA sequences were obtained from library clones. Comparison of the translated amino acid sequences to those publicly available confirmed similarity to arthropod anti-lipopolysaccharide factors. Both protein sequences, designated ALFHa-1 and ALFHa-2, contained an N-terminal signal peptide and two half-cysteines participating in a disulfide bridge, features conserved in other ALFs. Predicted secondary structures were similar to that described for the ALF from the horseshoe crab Limulus polyphemus. As part of an exploratory study of immunity in H. americanus, lobsters were injected with the bacterium Vibrio fluvialis and gill, hematopoietic, and hepatopancreas tissues were sampled for analysis of gene expression of ALFHa-1 and ALFHa-2 by quantitative PCR. The relative abundance of ALFHa-2 mRNA was not significantly affected by Vibrio injection in any of the three tissues tested. In contrast, ALFHa-1 mRNA levels in gills were increased by the treatment some 17-fold. Our results support a molecularly specific regulation of antimicrobial proteins in response to bacterial infection in H. americanus. (C) 2008 Elsevier Inc. Ail rights reserved

Optical and structural properties of CdS thin films prepared using electro-deposition technique

Cadmium Sulfide (CdS) thin films were electrodeposited successfully on to Indium Tin Oxide (ITO) coated glass substrates from an aqueous solution of pH 1.4 containing 0.3M CdCl2 and 0.03M Na2S2O3 or Thiourea with the aim of using in CdS/CdTe solar cells. Properties of CdS thin films prepared at different deposition voltages, deposition time periods, deposition temperatures and annealing temperatures were investigated using the current-voltage (I-V) plots. It was found that good quality CdS layers were formed under the deposition conditions of -1.13V for a period of 45 minutes in a solution of temperature at 46 oC. The performance of the CdS layers was improved significantly after annealing the samples at 400 oC for a period of 20 min. The properties of CdS thin films prepared by two and three electrode configurations and using two different electrolytes were compared using the current-voltage plots. It was found that there is a significant improvement of photocurrent of the samples prepared with two electrodes in Thiourea as the S source in comparison with the samples prepared with Na2S2O3. The analysis of XRD spectra showed the hexagonal crystal structure of CdS films confirming the quality of the films prepared by this method. In addition, absorption spectra showed band gap value of 2.42 eV proving that the samples were of good quality. Atomic Force Microscopy (AFM) analysis showed that the roughness values of CdS samples were in the range of 10-15 nm. Film thicknesses of the samples were in the range of 175-225 nm according to the optical profilometric data

Data visualization for Industry 4.0 : a stepping-stone toward a digital future, bridging the gap between academia and industry

Here, we analyze the potential of advanced data-visualization dashboards as an enabling technology for Industry 4.0. High-dimensional, real-time visualization allows the graphical expression of complex process variables at a fraction of the cost of full-scale digitalization. It is therefore a more achievable goal for smaller firms looking to transition to digital manufacturing and poses a realistic stepping-stone approach for Industry 4.0

Surface Geometric and Electronic Structure of BaFe2As2(001)

BaFe2As2 exhibits properties characteristic of the parent compounds of the newly discovered iron (Fe)-based high-TC superconductors. By combining the real space imaging of scanning tunneling microscopy/spectroscopy (STM/S) with momentum space quantitative Low Energy Electron Diffraction (LEED) we have identified the surface plane of cleaved BaFe2As2 crystals as the As terminated Fe-As layer - the plane where superconductivity occurs. LEED and STM/S data on the BaFe2As2(001) surface indicate an ordered arsenic (As) - terminated metallic surface without reconstruction or lattice distortion. It is surprising that the STM images the different Fe-As orbitals associated with the orthorhombic structure, not the As atoms in the surface plane.Comment: 12 pages, 4 figure

Damage detection and quantification in deck type arch bridges using vibration based methods and artificial neural networks

Vibration based methods can be used to detect damage in a structure as its vibration characteristics change with physical changes in the structure. Extensive research has been carried out on the use of such methods to detect damage in a number of simple and some complex structures. Arch bridge is a popular type of bridge with rather complex vibration characteristics which pose a challenge for using existing vibration based methods to detect damage in them. Further, its complex form of damage detection, even with modified vibration based methods makes the quantification process harder and challenging. This paper develops and applies a vibration based method especially suited for arch bridges to detect, locate and quantify damages in the structural components. In the proposed method, modified forms of the modal flexibility (MMF) and modal strain energy (MMSE) based damage indices coupled with the Artificial Neural Network (ANN) technology is used to provide an overall damage assessment. The procedure to detect and locate damage was experimentally validated and applied to a full scale long span arch bridge under a range of damage scenarios. Damage indices obtained from noise polluted vibration data are then used as input data for training and validation of the neural networks. Two neural networks were trained separately using MMF and MMSE damage indices and a network fusion approach is used to obtain unambiguous and accurate results for detecting, locating and quantifying damages. The trained neural network system was then successfully applied to identify unknown damages using only vibration data of damaged structural elements of arch bridges. The findings of this paper will contribute towards the safe and efficient operation of arch type bridges

IMPACT OF MACROECONOMIC VARIABLES ON STOCK MARKET PERFORMANCES: EVIDENCE FROM SRI LANKA

After eradicating 30 years of war, Sri Lanka has been rising like a phoenix bird rises from the ashes of its predecessor. With the golden opportunity to experience an impressive development within almost all the sectors inside the country, Colombo stock exchange (CSE) was labeled as the world’s best performing stock exchange according to Bloomberg in 2010. Unfortunately, it did not last longer. According to an analysis of Bespoke investment group in 2012, Colombo stock exchange became the second worst performing stock exchange ahead of Dhaka exchange in Bangladesh.The aim of this paper is to measure the impact of macroeconomic variables on the all share price index (ASPI) of CSE in Sri Lanka. Monthly data collected from publication of Central Bank of Sri Lanka from 2006 to 2016 were employed. In the model specification, two dummy variables were included to test the impact from civil war prevailed in the country and global financial crisis on share prices and the parameters were estimated using Ordinary Least Square (OLS) method. The results indicate that macroeconomic variables have an overall impact towards ASPI of Sri Lanka. Interest rate, industrial production index and civil war affected negatively on ASPI while US Dollar exchange rate and real GDP growth rate reacted positively on the all share price index. Importantly, global financial crisis positively affected the all share price index in Sri Lanka, which is contradictory to the experiences of developed countries. Study concluded that even though there is an uncertainty prevailing within external world, there is a tendency of attracting foreign investment towards capital market when a country is having a positive condition like Sri Lanka ending thirty years of war. Further, it reveals that inflation rate and money supply growth rate does not have a significant impact on the share price index of Sri Lanka. These findings can be significantly incorporated in government policy making which will be aimed at creating a strong capital market, investment decisions of local and foreign investor, stock market regulating authorities and financial analysts who develop forecasting models with reference to share price indexes.Keywords: Macroeconomic Impact, Colombo Stock Exchange, All share price index, Ordinary Least Square Method, Sri Lank

Effects of elevated seawater pCO2 on gene expression patterns in the gills of the green crab, Carcinus maenas

Background: The green crab Carcinus maenas is known for its high acclimation potential to varying environmental abiotic conditions. A high ability for ion and acid-base regulation is mainly based on an efficient regulation apparatus located in gill epithelia. However, at present it is neither known which ion transport proteins play a key role in the acid-base compensation response nor how gill epithelia respond to elevated seawater pCO2 as predicted for the future. In order to promote our understanding of the responses of green crab acid-base regulatory epithelia to high pCO2, Baltic Sea green crabs were exposed to a pCO2 of 400 Pa. Gills were screened for differentially expressed gene transcripts using a 4,462-feature microarray and quantitative real-time PCR. Results: Crabs responded mainly through fine scale adjustment of gene expression to elevated pCO2. However, 2% of all investigated transcripts were significantly regulated 1.3 to 2.2-fold upon one-week exposure to CO2 stress. Most of the genes known to code for proteins involved in osmo- and acid-base regulation, as well as cellular stress response, were were not impacted by elevated pCO2. However, after one week of exposure, significant changes were detected in a calcium-activated chloride channel, a hyperpolarization activated nucleotide-gated potassium channel, a tetraspanin, and an integrin. Furthermore, a putative syntaxin-binding protein, a protein of the transmembrane 9 superfamily, and a Cl-/HCO3 - exchanger of the SLC 4 family were differentially regulated. These genes were also affected in a previously published hypoosmotic acclimation response study. Conclusions: The moderate, but specific response of C. maenas gill gene expression indicates that (1) seawater acidification does not act as a strong stressor on the cellular level in gill epithelia; (2) the response to hypercapnia is to some degree comparable to a hypoosmotic acclimation response; (3) the specialization of each of the posterior gill arches might go beyond what has been demonstrated up to date; and (4) a re-configuration of gill epithelia might occur in response to hypercapnia