12 research outputs found

    Evaluation of Web Applications based on UX Parameters

    Get PDF
    The objective of evaluating User Experience (UX) in this era of technology is to enhance the user satisfaction. Earlier applications were built with the aim of reducing the work of users. But with the evolution of the technology, the emergence of new gadgets and new trends in the information technology, the applications had to be more user-centric. The primary objective of this research is to evaluate the user experience of web applications based on different UX parameters using different techniques and given a rating. Each of these ratings are combined to determine the overall rating of UX for the web application. Also, the secondary objective of this research is to provide suggestions or recommendations based on the ratings to improve the UX of the web applications. An experimental study was conducted and the results show a significant improvement. Areas of further enhancements have also been identified and presented

    Non-Kekulé polyaromatic hydrocarbons.

    Get PDF
    Non-Kekulé PAHs have been studied for a variety of applications due to the interesting chemistry they possess for such simple organic molecules. PAHs can have both closed and open-shell arrangements which have been of interest recently due to the potential magnetic and electronic properties they can acquire. Due to this, there has recently been a strong interest in graphene which can be viewed as a sheet of PAHs fused together. This thesis describes the formation of particular PAHs including open-shell compounds and how PAHs can be fully characterised using one technique. Chapter 2 describes the synthesis of 6H-benzo[cd]pyrene, the starting point of this project. Pentacene and perylene are other five fused ring structures like 6H-benzo[cd]pyrene which are commonly used due to their fluorescence, thus, this PAH could have interesting properties for material scientists. The production of the benzo[cd]pyrene radical by AFM/STM is then described. Chapter 3 describes peri-condensation reactions to form larger PAHs a technique which was commonly used in the 1900s for the addition of an aromatic ring, however, multiple ring additions have been reported to occur. In addition, carbon labelling experiments have been completed to confirm this and the mechanism by which multiple rings add have been discussed. STM/AFM has been used to characterise the compounds formed in the peri-condensation reactions as common techniques for characterisation do not provide enough structural data for compound determination. Chapter 4 discusses the synthesis of 3,8-dihydro-3H,8H-dibenzo[cd,mn]pyrene. Thereafter the use of AFM/STM is then utilised to dehydrogenate 3,8-dihydro-3H,8H-dibenzo[cd,mn]pyrene to form the non-Kekulé structure of triangulene which was simultaneously imaged for the first time

    Synthesis and cycloaddition reactions of derivatives of strained alkynes derived from 2,2’-dihydroxy-1,1’-biaryls

    Get PDF
    A series of strained alkynes, based on the 2,2’-dihydroxy-1,1’-biaryl structure, were prepared in a short sequence from readily-available starting materials. These compounds can be readily converted into further derivatives including examples containing fluorescent groups with potential for use as labelling reagents. The alkynes are able to react in cycloadditions with a range of azides without the requirement for a copper catalyst, in clean reactions with no observable side reactions

    Synthesis and characterization of triangulene

    Get PDF
    Triangulene, the smallest triplet-ground-state polybenzenoid (also known as Clar's hydrocarbon), has been an enigmatic molecule ever since its existence was first hypothesized1. Despite containing an even number of carbons (22, in six fused benzene rings), it is not possible to draw KekulĂ©-style resonant structures for the whole molecule: any attempt results in two unpaired valence electrons2. Synthesis and characterization of unsubstituted triangulene has not been achieved because of its extreme reactivity1, although the addition of substituents has allowed the stabilization and synthesis of the triangulene core3, 4 and verification of the triplet ground state via electron paramagnetic resonance measurements5. Here we show the on-surface generation of unsubstituted triangulene that consists of six fused benzene rings. The tip of a combined scanning tunnelling and atomic force microscope (STM/AFM) was used to dehydrogenate precursor molecules. STM measurements in combination with density functional theory (DFT) calculations confirmed that triangulene keeps its free-molecule properties on the surface, whereas AFM measurements resolved its planar, threefold symmetric molecular structure. The unique topology of such non-KekulĂ© hydrocarbons results in open-shell π-conjugated graphene fragments6 that give rise to high-spin ground states, potentially useful in organic spintronic devices7, 8. Our generation method renders manifold experiments possible to investigate triangulene and related open-shell fragments at the single-molecule level

    New developments in the InterPro database

    Get PDF
    InterPro is an integrated resource for protein families, domains and functional sites, which integrates the following protein signature databases: PROSITE, PRINTS, ProDom, Pfam, SMART, TIGRFAMs, PIRSF, SUPERFAMILY, Gene3D and PANTHER. The latter two new member databases have been integrated since the last publication in this journal. There have been several new developments in InterPro, including an additional reading field, new database links, extensions to the web interface and additional match XML files. InterPro has always provided matches to UniProtKB proteins on the website and in the match XML file on the FTP site. Additional matches to proteins in UniParc (UniProt archive) are now available for download in the new match XML files only. The latest InterPro release (13.0) contains more than 13 000 entries, covering over 78% of all proteins in UniProtKB. The database is available for text- and sequence-based searches via a webserver (), and for download by anonymous FTP (). The InterProScan search tool is now also available via a web service at

    Adsorption geometry determination of single molecules by atomic force microscopy

    Get PDF
    We measured the adsorption geometry of single molecules with intramolecular resolution using noncontact atomic force microscopy with functionalized tips. The lateral adsorption position was determined with atomic resolution, adsorption height differences with a precision of 3 pm, and tilts of the molecular plane within 0.2°. The method was applied to five π-conjugated molecules, including three molecules from the olympicene family, adsorbed on Cu(111). For the olympicenes, we found that the substitution of a single atom leads to strong variations of the adsorption height, as predicted by state-of-the-art density-functional theory, including van der Waals interactions with collective substrate response effects

    Analysis of tool wear in ultrasonically assisted turning of beta-Ti-15V-3Al-3Cr-3Sn alloy

    Get PDF
    An extremely high tool wear rate in the machining of titanium alloys (Ti alloys) is one of the major reasons limiting the use of conventional machining processes for the components made of these alloys. The machinability of a -Ti-15V-3Al-3Cr-3Sn (Ti- 15333) alloy can be signi cantly improved using an advanced machining technique known as Ultrasonically Assisted Turning (UAT). The key mechanism of tool wear associated with UAT of Ti-15333 alloy is still unknown. The present study begins to address this issue by examining wear behaviour of two di erent types of cutting inserts using UAT and Conventional Turning (CT) of Ti-15333 alloy. Tool wear was measured using 3D optical microscope and the composition of the Built-Up Edge (BUE) on the worn tools was analysed with scanning electron microscopy. A robust experimental methodology was developed, which provided repeatable and statistically reliable tool wear results. The KC5510 cutting inserts demonstrated better tool-life in UAT when compared to CP-500 inserts

    The synthesis and STM/AFM imaging of ‘Olympicene’ benzo[cd]pyrenes

    No full text
    H-Benzo[cd]pyrene (‘Olympiceneâ€Č) is a polyaromatic hydrocarbon and non-KekulĂ© fragment of graphene. A new synthetic method has been developed for the formation of 6H-benzo[cd]pyrene and related ketones including the first time isolation of the unstable alcohol 6H-benzo[cd]pyren-6-ol. Molecular imaging of the reaction products with scanning tunnelling microscopy (STM) and non-contact atomic force microscopy (NC-AFM) characterised the 6H-benzo[cd]pyrene as well as the previously intangible and significantly less stable 5H-benzo[cd]pyrene, the fully conjugated benzo[cd]pyrenyl radical and the ketones as oxidation products
    corecore