A study on performance evaluation of mutual funds with reference to Cochin stock exchange Ltd

This study is an attempt to identify overpriced and underpriced shares chosen. It can be used as a guide for the investors to make a purchase or sell decision for a particular security. The sample of securities of 8 private sector banks were selected and using either anticipation approach to estimate the value of a shares are calculated. As per anticipation approach future price of a share is estimated through trend analysis which will be compared with actual share price on a particular date to find whether the share is underpriced or overpriced

Statistical modeling of daily extreme rainfall in Colombo

The occurrence of heavy rainfalls in Sri Lanka results in significant damage to agriculture, ecology, infrastructure systems, disruption of human activities, injuries and the loss of life. The modelling of extreme rainfall has to be developed to manage the natural resources and the built environment to face the impacts of climate change. The main goal of this study is to find the best fitting distribution to the extreme daily rainfalls measured over the Colombo region for the years 1900-2009 by using the maximum likelihood approach. The study also predicts the extreme rainfalls for return periods and their confidence bands. In this study extreme rainfall events are defined by two different methods based on (1) the annual maximums of the daily rainfalls and (2) the daily rainfalls exceeds some specific threshold value. The Generalized Extreme Value distribution and the Generalized Pareto distribution are fitted to data corresponding to the methods 1 and 2 to describe the extremes of rainfall and to predict its future behaviour. Finally we find the evidence to suggest that the Gumbel distribution provides the most appropriate model for the annual maximums of daily rainfall and the Exponential distribution gives the reasonable model for the daily rainfall data over the threshold value of 100mm for the Colombo location. We derive estimates of 5, 10, 20, 50 and 100 years return levels and its corresponding confidence intervals for extreme daily rainfalls

Development and certification of chromic acid-free anodizing process for aircraft grade aluminium alloys

21-27Chromic acid (Cr6+) anodization process is widely used for the corrosion protection of aircraft aluminium alloys. Hexavalent chromium being toxic in nature need to be phased out by eco-friendly alternatives. In the present study modified tartaric-sulphuric acid (TSA) process has been developed followed by sealing in permanganate based bath to obtain 4 to 6 µm thick anodic oxide layer on 2024-T3, 6061-T6 and 7075-T6 aluminium alloys. The process was carried out using a pilot scale anodizing plant. The anodized specimens were characterized for visual observation, thickness, adhesion, electrical breakdown voltage, corrosion resistance and tensile behaviour. All the tests were carried out as per MIL-A-8625F specifications. The specimens were also subjected for about 800 hrs to real time corrosion testing, 200 metres away from sea shore at Mandapam Camp, Rameshwaram, India. The performance of the permanganate sealed TSA anodized aluminium alloys are comparable with that of the conventional chromic acid anodized coatings. This chromic acid-free anodization process has been qualified to airworthiness regulating standards by Indian military certification authorities. Efforts are in progress to commercialize this technology for use on aero platforms

Development and certification of chromic acid-free anodizing process for aircraft grade aluminium alloys

Chromic acid (Cr6+) anodization process is widely used for the corrosion protection of aircraft aluminium alloys. Hexavalent chromium being toxic in nature need to be phased out by eco-friendly alternatives. In the present study modified tartaric-sulphuric acid (TSA) process has been developed followed by sealing in permanganate based bath to obtain 4 to 6 µm thick anodic oxide layer on 2024-T3, 6061-T6 and 7075-T6 aluminium alloys. The process was carried out using a pilot scale anodizing plant. The anodized specimens were characterized for visual observation, thickness, adhesion, electrical breakdown voltage, corrosion resistance and tensile behaviour. All the tests were carried out as per MIL-A-8625F specifications. The specimens were also subjected for about 800 hrs to real time corrosion testing, 200 metres away from sea shore at Mandapam Camp, Rameshwaram, India. The performance of the permanganate sealed TSA anodized aluminium alloys are comparable with that of the conventional chromic acid anodized coatings. This chromic acid-free anodization process has been qualified to airworthiness regulating standards by Indian military certification authorities. Efforts are in progress to commercialize this technology for use on aero platforms

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Design of medium band gap random terpolymers containing fluorene linked diketopyrrolopyrrole and thiophene co-monomers: an experimental and theoretical study

In this study, new polymers PTFDPP, PBTFDPP, PTTFDPP, PTCNEFDPP, PTDCNFDPP and PTPTFDPP were designed and synthesized by employing a D–A random copolymer strategy involving 9,9-dihexylfluorene (electron donor) linked to diketopyrrolopyrrole (electron acceptor) and thiophene comonomer (as donor as well as acceptor). Their optical band gap and HOMO and LUMO energy levels were estimated from ultraviolet-visible spectroscopy and cyclic voltammetry. By changing the nature of thiophene from donor to acceptor state, the HOMO and LUMO energy levels and optical band gaps were modified, which varied from 1.75 to 1.65 eV. A series of systematic density functional theory (DFT) calculations have been performed on model co-polymers to gain insights into the structural, electronic, optical and charge transport properties. The experimental values are in close agreement with calculated electronic properties. Salient findings from both experimental and calculated values indicate that these new polymers can be efficiently exploited for the development of new donor materials for OPV applications

White light emitting polymers from a luminogen with local polarity induced enhanced emission

Aggregation induced enhanced emission (AIEE) is considered as an important tool to circumvent the aggregation caused quenching (ACQ) effect in organic light emitting diodes (OLEDs). Charge trapping and surplus long wavelength electroluminescence is a cause of concern in single polymer based white OLEDs. However, the potential of luminogens with AIEE property as a credible tool to offset the above problems in white light emitting single polymer is not properly explored. In this study design, synthesis and spectral characterization of a polymerizable luminogen, (2Z,2′Z)-6,6′-(2,7-dibromo-9H-fluorene-9,9-diyl)bis(hexane-6,1-diyl)bis(2-cyano-3-(10-hexyl-10H-phenothiazin-3-yl)acrylate(FCPA) with AIEE property and its copolymers is presented. Lippert-Mataga studies showed that reduced local polarity caused by aliphatic chains in condensed state of FCPA resulted in AIEE property. The copolymers P(FCPA-1) and P(FCPA-0.5) with 1% and 0.5% FCPA moieties showed white electroluminescence and enhanced thin film photoluminescence that matched very closely. The superior performance of OLEDs is attributed to the presence of a phenothiazine group in FCPA that resulted in nearly equal electron and hole injection barriers