7,261 research outputs found

    Approximating electronically excited states with equation-of-motion linear coupled-cluster theory

    Full text link
    A new perturbative approach to canonical equation-of-motion coupled-cluster theory is presented using coupled-cluster perturbation theory. A second-order M{\o}ller-Plesset partitioning of the Hamiltonian is used to obtain the well known equation-of-motion many-body perturbation theory (EOM-MBPT(2)) equations and two new equation-of-motion methods based on the linear coupled-cluster doubles (EOM-LCCD) and linear coupled-cluster singles and doubles (EOM-LCCSD) wavefunctions. This is achieved by performing a short-circuiting procedure on the MBPT(2) similarity transformed Hamiltonian. These new methods are benchmarked against very accurate theoretical and experimental spectra from 25 small organic molecules. It is found that the proposed methods have excellent agreement with canonical EOM-CCSD state for state orderings and relative excited state energies as well as acceptable quantitative agreement for absolute excitation energies compared with the best estimate theory and experimental spectra.Comment: 9 pages 3 figure

    The role of trait emotional intelligence in academic performance: theoretical overview and empirical update

    Get PDF
    Considerable debate still exists among scholars over the role of trait emotional intelligence (TEI) in academic performance. The dominant theoretical position is that TEI should be orthogonal or only weakly related to achievement; yet, there are strong theoretical reasons to believe that TEI plays a key role in performance. The purpose of the current article is to provide (a) an overview of the possible theoretical mechanisms linking TEI with achievement and (b) an update on empirical research examining this relationship. To elucidate these theoretical mechanisms, the overview draws on multiple theories of emotion and regulation, including TEI theory, social-functional accounts of emotion, and expectancy-value and psychobiological model of emotion and regulation. Although these theoretical accounts variously emphasize different variables as focal constructs, when taken together, they provide a comprehensive picture of the possible mechanisms linking TEI with achievement. In this regard, the article redresses the problem of vaguely specified theoretical links currently hampering progress in the field. The article closes with a consideration of directions for future research

    Fabricating New Miniaturized Biosensors for the Detection of Dna Damage and Dna Mismatches

    Get PDF
    A large number of genetic diseases and genetic disorders are simply caused by base alterations in the genome. Therefore, developing efficient and cost effective techniques for routine detection of these alterations is of great importance. Different methods involving gel electrophoresis and Polymerase Chain Reaction have been widely employed, but majority of these methods are costly, time consuming, and lack throughput, creating a fundamental gap between the current state-of-the-art and desired characteristics of low-cost, high-speed, simplicity, versatility, and potential for miniaturization. In this study, we attempt to bridge this gap by developing new sensing platforms to detect DNA base mismatches and DNA damage with higher throughput, better ease-of-use, and with the potential to be miniaturized for greater portability. Two electrochemical mismatch detection sensing platforms were developed. One uses the electrochemical reduction of trans-4-cinnamic acid diazonium tetrafluoroborate. The other takes advantage of the natural ability of MutS protein for single base mismatch recognition. Also, two DNA damage detection assays were developed and the first approach uses Atomic Force Microscopy to monitor minor DNA damage by labeling damaged sites with a biomarker. This site-specific biolabeling was achieved through well-established biotin-streptavidin chemistry. In the second approach, a new layer-by-layer biomolecular immobilization method was introduced and used to detect DNA chemical damage using electrochemical technique

    Electron Transfer In Phosphido-Bridged Complexes

    Get PDF

    Fabricating New Miniaturized Biosensors for the Detection of Dna Damage and Dna Mismatches

    Get PDF
    A large number of genetic diseases and genetic disorders are simply caused by base alterations in the genome. Therefore, developing efficient and cost effective techniques for routine detection of these alterations is of great importance. Different methods involving gel electrophoresis and Polymerase Chain Reaction have been widely employed, but majority of these methods are costly, time consuming, and lack throughput, creating a fundamental gap between the current state-of-the-art and desired characteristics of low-cost, high-speed, simplicity, versatility, and potential for miniaturization. In this study, we attempt to bridge this gap by developing new sensing platforms to detect DNA base mismatches and DNA damage with higher throughput, better ease-of-use, and with the potential to be miniaturized for greater portability. Two electrochemical mismatch detection sensing platforms were developed. One uses the electrochemical reduction of trans-4-cinnamic acid diazonium tetrafluoroborate. The other takes advantage of the natural ability of MutS protein for single base mismatch recognition. Also, two DNA damage detection assays were developed and the first approach uses Atomic Force Microscopy to monitor minor DNA damage by labeling damaged sites with a biomarker. This site-specific biolabeling was achieved through well-established biotin-streptavidin chemistry. In the second approach, a new layer-by-layer biomolecular immobilization method was introduced and used to detect DNA chemical damage using electrochemical technique

    Feasibility of valuing credit risk in the financial market in Sri Lanka: a case study

    Get PDF
    The Sri Lankan financial market uses non analytical techniques to quantify credit risk. Credit derivatives are not used to transfer credit risk. A Credit Default Swap (CDS) is the most widely used credit derivative to manage credit risk. To evaluate the price of CDS, various sophisticated methods are used. This research paper focuses on techniques to hedge credit risk in the Sri Lankan financial market, the behaviours of CDS in derivative markets, calculating a fair value of CDS, the main advantages of using credit derivatives, and major imperfections to use the pricing process of CDS in the Sri Lankan marke

    MOVING BEYOUND THE CBD’S 2010 TARGET - A REVIEW ON THE EFFECTIVEHESS OF FAUNA AND FLORA PROTECTION ORDINANCE IN PROTECTED AREA ESTABLISHMENT IN SRI LANKA

    Get PDF
    The CBD target to protect at least 10 per cent of each of the world‟s ecological regions by 2010 has not been achieved globally, although good  progress was reported by many countries.  This paper present the results of a comprehensive review undertaken with the objective of evaluating the effectiveness of the Fauna and Flora Protection Ordinance No 2 of 1937 (FFPO) and its amendments, as a framework legislation for Protected Area (PA)establishment in Sri Lanka.  The FFPO was enacted aiming to protect indigenous fauna and flora, and over the years its emphasis  has shifted from that of the preservation of wildlife to protection of biodiversity for  the benefit of present and future generations.  It has introduced eleven categories of PAs, of which five are in existence on ground. 93 PAs covering 943,595 ha has been established, representing 14% of land cover and 0.63% of the EEZ.    62% of the PAs are below 5,000 ha in size, an indication to increasing human-animal conflicts. FFPO is presently being supplemented by several other sectoral enactments in PA establishment. As the demand for development are underpinning the establishment of new PAs  and maintaining the existing ones,  it is now vital to look at the possibility of consolidating relevant enactments under single legislation, or to develop a coordination mechanism under one institution, which is specifically designed for PA establishment and management.  Further a long-term scientific plan that includes a significant role for civil society and private sector is needed

    Optimal design of an aeroelastic wing structure with seamless control surfaces

    Get PDF
    This article presents an investigation into the concept and optimal design of a lightweight seamless aeroelastic wing (SAW) structure for small air vehicles. Attention has been first focused on the design of a hingeless flexible trailing edge (TE) control surface. Two innovative design features have been created in the SAW TE section: an open sliding TE and a curved beam and disc actuation mechanism. This type of actuated TE section allows for the SAW having a camber change in a desirable shape and minimum control power demand. This design concept has been simulated numerically and demonstrated by a test model. For a small air vehicle of large sweep back wing, it is noted that significant structural weight saving can be achieved. However, further weight saving is mainly restricted by the aeroelastic stability and minimum number of carbon/epoxy plies in a symmetric layup rather than the structural strength. Therefore, subsequent effort was made to optimize the primary wing box structure. The results show that an initial structural weight can be reduced significantly under the strength criterion. The resulting reduction of the wing box stiffness and aeroelastic stability and control effectiveness can be improved by applying the aeroelastic tailoring. Because of the large swept angle and resulting lightweight and highly flexible SAW, geometrical non-linearity and large bending-torsion aeroelastic coupling have been considered in the analysis
    corecore