Recent Submissions

  • (Bio)degradable polymeric materials for a sustainable future – part 1. Organic recycling of PLA/PBAT blends in the form of prototype packages with long shelf-life

    Musioł, Marta; Sikorska, Wanda; Janeczek, Henryk; Wałach, Wojciech; Hercog, Anna; Johnston, Brian; Rydz, Joanna (Elsevier, 2018-07)
    Prediction studies of advanced (bio)degradable polymeric materials are crucial when their potential applications as compostable products with long shelf-life is considered for today’s market. The aim of this study was to determine the effect of the polylactide (PLA) content in the blends of PLA and poly(butylene adipate-co-terephthalate) (PBAT); specifically how the material’s thickness corresponded to changes that occurred in products during the degradation process. Additionally, the influence of talc on the degradation profile of all samples in all environments was investigated. It was found that, differences in the degradation rate of materials tested with a similar content of the PLA component could be caused by differences in their thickness, the presence of commercial additives used during processing or a combination of both. The obtained results indicated that the presence of talc may interfere with materials behavior towards water and consequently alter their degradation profile.
  • Three-Dimensional Modelling of a Microtubular SOFC: A Multiphysics Approach

    Hodjati-Pugh, Oujen; Dhir, Aman; Steinberger-Wilckens, Robert (The Electrochemical Society, 2017-07-28)
    Microtubular Solid Oxide Fuel Cells (µ-SOFC) are suited to a broad spectrum of applications with power demands ranging from a few watts to several hundred watts. µ-SOFC’s possess inherently favourable characteristics over alternate configurations such as high thermo-mechanical stability, high volumetric power density and rapid start-up times. Computational modelling at the design level minimises cost and maximises productivity, giving critical insight into complex SOFC phenomena and their interrelationships. To date, models have been limited by oversimplified geometries, often failing to account for oxidant supply complexities, gas distribution within pores and radiative heating effects (1-3). Here, a three-dimensional Computational Fluid Dynamics (CFD) model of electrodes, electrolyte, current collectors and furnace is considered using COMSOL Multiphysics. The distribution of temperature, current density, electrical potential, pressure and gas concentrations throughout the cell are simulated. Results show good correlation with experimental data and the model is reliable for prediction of fuel cell performance within set parameters.
  • A new species of the Cyrtodactylus (Geckoella) collegalensis (Beddome, 1870) complex (Squamata: Gekkonidae) from Western India

    A new species of Cyrtodactylus (Geckoella) from the C. collegalensis complex is described based on a series of specimens from western and central India. Morphological and molecular data support the distinctiveness of the new form, which can be diagnosed from other Cyrtodactylus (including other Geckoella) species by its small body size (snout to vent length to 56 mm), the absence of precloacal and femoral pores, no enlarged preanal or femoral scales, and a dorsal scalation consisting wholly of small, granular scales. The new species is most closely related to C. collegalensis, C. speciosus and C. yakhuna, from which it differs by the presence of a patch of enlarged roughly hexagonal scales on the canthus rostralis and beneath the angle of jaw, its relatively long limbs and narrow body, and a dorsal colour pattern of 4–6 pairs of dark spots.
  • Multi-locus phylogeny and species delimitation of Australo-Papuan blacksnakes ( Pseudechis Wagler, 1830: Elapidae: Serpentes)

    Maddock, Simon T.; Childerstone, Aaron; Fry, Bryan Grieg; Williams, David J.; Barlow, Axel; Wüster, Wolfgang (Elsevier, 2017-02)
    Genetic analyses of Australasian organisms have resulted in the identification of extensive cryptic diversity across the continent. The venomous elapid snakes are among the best-studied organismal groups in this region, but many knowledge gaps persist: for instance, despite their iconic status, the species-level diversity among Australo-Papuan blacksnakes (Pseudechis) has remained poorly understood due to the existence of a group of cryptic species within the P. australis species complex, collectively termed ‘‘pygmy mulga snakes”. Using two mitochondrial and three nuclear loci we assess species boundaries within the genus using Bayesian species delimitation methods and reconstruct their phylogenetic history using multispecies coalescent approaches. Our analyses support the recognition of 10 species, including all of the currently described pygmy mulga snakes and one undescribed species from the Northern Territory of Australia. Phylogenetic relationships within the genus are broadly consistent with previous work, with the recognition of three major groups, the viviparous red-bellied black snake P. porphyriacus forming the sister species to two clades consisting of ovoviviparous species
  • Microsatellite discovery in an insular amphibian (Grandisonia alternans) with comments on cross-species utility and the accuracy of locus identification from unassembled Illumina data

    Adamson, Eleanor A. S.; Saha, Anwesha; Maddock, Simon T.; Nussbaum, Ronald A.; Gower, David J.; Streicher, Jeffrey W. (Springer, 2016-07-29)
    The Seychelles archipelago is unique among isolated oceanic islands because it features an endemic radiation of caecilian amphibians (Gymnophiona). In order to develop population genetics resources for this system, we identified microsatellite loci using unassembled Illumina MiSeq data generated from a genomic library of Grandisonia alternans, a species that occurs on multiple islands in the archipelago. Applying a recently described method (PALFINDER) we identified 8001 microsatellite loci that were potentially informative for population genetics analyses. Of these markers, we screened 60 loci using five individuals, directly sequenced several amplicons to confirm their identity, and then used eight loci to score allele sizes in 64 G. alternans individuals originating from five islands. A number of these individuals were sampled using non-lethal methods, demonstrating the efficacy of non-destructive molecular sampling in amphibian research. Although two loci satisfied our criteria as diploid, neutrally evolving loci with the statistical power to detect population structure, our success in identifying reliable loci was very low. Additionally, we discovered some issues with primer redundancy and differences between Illumina and Sanger sequences that suggest some Illumina-inferred loci are invalid. We investigated cross-species utility for eight loci and found most could be successfully amplified, sequenced and aligned across other species and genera of caecilians from the Seychelles. Thus, our study in part supported the validity of using PALFINDER with unassembled reads for microsatellite discovery within and across species, but importantly identified major limitations to applying this approach to small datasets (ca. 1 million reads) and loci with small tandem repeat sizes.
  • Performance measurement of the upgraded Microcab-H4 with academic drive cycle

    Rais, Luthfi; Fisher, Peter; Dhir, Aman; Steinberger-Wilckens, Robert (Communications in Science and Technology, 2016-05-31)
    The original Microcab-H4, a hybrid fuel cell car, was tested with Academic drive cycle. After several years, the car was upgraded and tested with the ECE 15 drive cycle. The result showed the car has higher energy efficiency. However, the result could not be compared to the original car due to different drive cycle test. This research was done to measure the performance and energy efficiency of the Upgraded Microcab-H4 with Academic drive cycle. The measure of car energy efficiency was done through four tests: Run on battery, run on battery and Ballard fuel cell, and run on battery, Ballard, and Horizon fuel cell. The energy efficiency was calculated based on the hydrogen consumption after 5 cycles. The lowest energy efficiency was run on battery and Ballard fuel cell with (1.01 km/MJ). The highest energy efficiency was run on battery, Ballard, and Horizon fuel cells (1.10 km/MJ), which is higher than previous tests.
  • Effects of synthetic iron and aluminium oxide surface charge and hydrophobicity on the formation of bacterial biofilm

    Pouran, Hamid M.; Banwart, Steve A.; Romero-Gonzalez, Maria; LMEI; School of Earth and Environment; Department of Geography (Royal Society of Chemistry, 2017-03-08)
    In this research, bacterial cell attachments to hematite, goethite and aluminium hydroxide were investigated.
  • Development, Optimisation, Validation and Inter-Laboratory Verification of a Reversed Phase HPLC Method for Quantification of Human Recombinant Insulin

    Iyire, Affiong; Russell, Craig; Dennison, Tom; Rajoli, Rajith; Saleem, Imran; Rahman, Ayesha; Mohammed, Afzal (JOURNAL OF ADVANCES IN BIOTECHNOLOGY, 2018-03-27)
    HPLC methods for insulin in official monographs require extended runtimes and elevated temperatures. Inter-laboratory reproducibility of HPLC methods obtained from published literature is an on-going challenge, moreso for peptides. This paper serves as a step-by step guide to troubleshoot and establish a validated HPLC method for insulin at room temperature using simple UV detectors with minimal run times. A modified gradient reversed-phase HPLC was developed for the quantification of recombinant human insulin with UV detection at room temperature.  An octadecylsilica column was used as the stationary phase while the mobile phase consisted of solution A: 1mmol sodium sulphate and 0.2% triethylamine in water and solution B: acetonitrile. The developed method was then validated using International Conference on Harmonisation (ICH) guidelines. The calibration curve was linear over a concentration range of 10-1000 µg/mL with correlation coefficient of 0.9993, with average recovery percent of 100.89 ± 1.4% and RSD recovery of 0.01. Insulin retention time was 3.84 ± 0.08 mins, while LOD and LOQ were estimated at 0.63 and 2.0 µg/mL respectively. The developed method conformed to the validation criteria of the ICH guidelines in our laboratories and other independent operator laboratories, and can serve as a rapid and effective method for quantifying insulin from any sample at room temperature using simple detectors.
  • Self-assembly of pH-sensitive fluorinated peptide dendron functionalized dextran nanoparticles for on-demand intracellular drug delivery.

    Ma, Shengnan; Zhou, Jie; Wali, Aisha Roshan Mohamed; He, Yiyan; Xu, Xianghui; Tang, James Zhenggui; Gu, Zhongwei (2015-08)
    In this study, the amphiphilic fluorinated peptide dendrons functionalized dextran (FPD-HZN-Dex) via an acid-sensitive hydrazone linkage was successfully designed and prepared for the first time. We demonstrated a spontaneous self-assembly of amphiphilic FPD-HZN-Dex into the well-defined nanoparticles with the core-shell architecture in aqueous media, which is attributed to the efficient amphiphilic functionalization of dextran by the hydrophobic fluorinated peptide dendrons. The spherical morphology, uniform particle size and good storage stability of the prepared FPD-HZN-Dex nanoparticles were characterized by dynamic light scattering and transmission electron microscopy, respectively. In vitro drug release studies showed a controlled and pH dependent hydrophobic drug release profile. The cell viability assays show excellent biocompatibility of the FPD-HZN-Dex nanoparticles for both normal cells and tumor cells. Moreover, the FPD-HZN-Dex self-assembled systems based on pH-sensitive hydrazone linkage also can serve as stimulus bioresponsive carriers for on-demand intracellular drug delivery. These self-assembled nanoparticles exhibit a stimulus-induced response to endo/lysosome pH (pH 5.0) that causes their disassembly over time, enabling controlled release of encapsulated DOX. This work has unveiled a unique non-covalent interaction useful for engineering amphiphilic dendrons or dendrimers self-assembled systems.
  • A Model for Android and iOS Applications Risk Calculation: CVSS Analysis and Enhancement Using Case-Control Studies

    Petraityte, Milda; Dehghantanha, Ali; Epiphaniou, Gregory (Elsevier, 2018)
    Various researchers have shown that the Common Vulnerability Scoring System (CVSS) has many drawbacks and may not provide a precise view of the risks related to software vulnerabilities. However, many threat intelligence platforms and industry-wide standards are relying on CVSS score to evaluate cyber security compliance. This paper suggests several improvements to the calculation of Impact and Exploitability sub-scores within the CVSS, improve its accuracy and help threat intelligence analysts to focus on the key risks associated with their assets. We will apply our suggested improvements against risks associated with several Android and iOS applications and discuss achieved improvements and advantages of our modelling, such as the importance and the impact of time on the overall CVSS score calculation.
  • Network Aware Composition for Internet of Thing Services

    Galadima Shehu, Umar; Ali Safdar, Ghazanfar; Epiphaniou, Gregory (2015-02-28)
    To enhance the adoption of Internet of Things (IoT) philosophy for the internet, research into IoT service composition has gathered momentum. In a distributed IoT environment, identifying IoT service among a set of similar service offerings that meets both functional and performance requirements of an IoT application has become important. However, the performance of a service cannot be guaranteed. Therefore service’s QoS and network characteristics are required to aggregate IoT services. Most existing composition approaches only consider non-network related QoS properties at the application tier. However they do not consider the network parameters such as network latency at the application level in selection and composition of services. Therefore we propose two evolutionary algorithms for IoT service composition that consider not only QoS but also network latency at the IoT application layer. The algorithms are discussed and results of evaluation are presented. The results indicate that our algorithms are efficient in finding QoS optimal and low latency solutions.
  • Effective Compact Agreements: Improving Public Housing Estates’ Delivery and Post-Construction Management in Nigeria

    Obi, Lovelin Ifeoma; Ihua, P.W. (Quest Journal, 2015)
    Practicing effective compact agreement building among the relevant stakeholders’ in the public housing sector is becoming necessary and indispensable to progress public housing estates development and the post-construction management. Irrespective of this, evidence of a lack of effectiveness in this area is prevalent, especially in Nigeria, that most public housing estates are uncompleted and have no thereafter management care. This study assesses the importance and benefits of building an effective compact agreement, to improving the public housing estates delivery and the post-construction management. A qualitative documentary inquiry of relevant online and visual document resources, shadowed by a revelatory of categories and limits of various information contained in the resources to the singularity in the study was adopted. The Relative Importance Index (RII) techniques and some SPSS descriptive packages were used in the analysis of the primary data, with the overall results thematically assessed utilising context analysis approach. The study reveals that improvements in the social housing estates’ development and the post-construction management is realisable and sustainable when a sound and solid treaty is concretised and embraced in the housing estates’ project development by the relevant stakeholders’. It further underscores that an effective compact agreement in the housing estate development and post-construction management encourages successful: project development and post-construction management; transparency; good governance; accountability; and sustainability; and that sixteen factors were important in the successful compact building. Accessing appropriate and adequate shelter by people is essential since it improves living conditions and welfare. Studying the importance of an effective compact in public housing estates development and post-construction management exposes and distinguishes the potential benefits to the relevant stakeholders. It assists improve the unattractive physical state of affairs of public housing estates in Nigeria and should be seen as a best practice in order to achieve public housing estates development and post-construction management sustainability.
  • Statistical properties and time-frequency analysis of temperature, salinity and turbidity measured by the MAREL Carnot station in the coastal waters of Boulogne-sur-Mer (France)

    Kbaier Ben Ismail, Dhouha; Lazure, Pascal; Puillat, Ingrid (Elsevier, 2016-04-06)
    In marine sciences, many fields display high variability over a large range of spatial and temporal scales, from seconds to thousands of years. The longer recorded time series, with an increasing sampling frequency, in this field are often nonlinear, nonstationary, multiscale and noisy. Their analysis faces new challenges and thus requires the implementation of adequate and specific methods. The objective of this paper is to highlight time series analysis methods already applied in econometrics, signal processing, health, etc. to the environmental marine domain, assess advantages and inconvenients and compare classical techniques with more recent ones. Temperature, turbidity and salinity are important quantities for ecosystem studies. The authors here consider the fluctuations of sea level, salinity, turbidity and temperature recorded from the MAREL Carnot system of Boulogne-sur-Mer (France), which is a moored buoy equipped with physico-chemical measuring devices, working in continuous and autonomous conditions. In order to perform adequate statistical and spectral analyses, it is necessary to know the nature of the considered time series. For this purpose, the stationarity of the series and the occurrence of unit-root are addressed with the Augmented–Dickey Fuller tests. As an example, the harmonic analysis is not relevant for temperature, turbidity and salinity due to the nonstationary condition, except for the nearly stationary sea level datasets. In order to consider the dominant frequencies associated to the dynamics, the large number of data provided by the sensors should enable the estimation of Fourier spectral analysis. Different power spectra show a complex variability and reveal an influence of environmental factors such as tides. However, the previous classical spectral analysis, namely the Blackman–Tukey method, requires not only linear and stationary data but also evenly-spaced data. Interpolating the time series introduces numerous artifacts to the data. The Lomb–Scargle algorithm is adapted to unevenly-spaced data and is used as an alternative. The limits of the method are also set out. It was found that beyond 50% of missing measures, few significant frequencies are detected, several seasonalities are no more visible, and even a whole range of high frequency disappears progressively. Furthermore, two time-frequency decomposition methods, namely wavelets and Hilbert–Huang Transformation (HHT), are applied for the analysis of the entire dataset. Using the Continuous Wavelet Transform (CWT), some properties of the time series are determined. Then, the inertial wave and several low-frequency tidal waves are identified by the application of the Empirical Mode Decomposition (EMD). Finally, EMD based Time Dependent Intrinsic Correlation (TDIC) analysis is applied to consider the correlation between two nonstationary time series.
  • Visualizing the intercity railway network in Mainland China

    Niu, Fangqu; Li, Jun; Chinese Academy of Sciences, China; University of Wolverhampton, UK (Sage, 2018-01-31)
    This study uses an equal population cartogram to plot the intercity railway network in Mainland China.
  • Food spectrum analysis of the Asian toad, Duttaphrynus melanostictus (Schneider, 1799) (Anura: Bufonidae), from Timor Island, Wallacea

    Döring, Britta; Mecke, Sven; Kieckbusch, Max; O’Shea, Mark; Kaiser, Hinrich (Talyor & Francis, 2017-03-20)
    Abstract: The Asian toad, Duttaphrynus melanostictus (Schneider, 1799), is widespread throughout tropical Asia and very abundant where it occurs. It was relatively recently introduced to Timor, the second largest island in the biogeographic region called Wallacea. Timor Island shows an and there are concerns that D. melanostictus may have a negative impact on this diversity, including vertebrates, through direct predation.To evaluate the impact the diet of D. melanostictus might have on the local fauna, gut contents of 83 preserved toad specimens from five habitat types in Timor-Leste, a country occupying the eastern half of Timor Island, were examined. We identified 5581 prey items, comprising the following animal groups: annelids; snails and slugs; spiders and harvestmen; woodlice; millipedes and centipedes; grasshoppers, crickets and earwigs; termites; thrips and true bugs; beetles; ants; hymenopterans other than ants; true flies; butterflies; unidentified insects; and insect larvae. Small eusocial insects (ants and termites) constituted the major part of the diet (61.6% and 23.4%, respectively). No vertebrate prey was recorded. Prey item composition did not differ between habitats. The wide prey spectrum well indicates that D. melanostictus is a generalist invertebrate feeder, as other studies, from regions where this species occurs naturally, have already shown. Although the Asian toad seems to not generally prey on vertebrates, vertebrate species that are morphologically similar to invertebrates in their overall appearance may be consumed. Hence, a negative effect on some taxa (e.g. blindsnakes) may be possible. We also present some limited data on intestinal parasites occurring in D. melanostictus.
  • Developments of electric cars and fuel cell hydrogen electric cars

    Wilberforce, Tabbi; El-Hassan, Zaki; Khatib, F.N.; Al Makky, Ahmed; Baroutaji, Ahmad; Carton, James G.; Olabi, Abdul G. (Elsevier, 2017-08)
    The world continues to strive in the search for clean power sources to run the millions of different vehicles on the road on daily basis as they are the main contributors to toxic emissions releases from internal combustion engines to the atmosphere. These toxic emissions contribute to climate change and air pollution and impact negatively on people's health. Fuel cell devices are gradually replacing the internal combustion engines in the transport industry. Some notable challenges of the PEMFC technology are discussed in this paper. High costs, low durability and hydrogen storage problems are some of the major obstacles being examined in this investigation. The paper explores the latest advances in electric cars technology and their design specifications. The study also compares the characteristics and the technologies of the three types of electric cars now available in the market.
  • A 140-year-old specimen from the southern Trans-Fly region of Papua New Guinea proves that the Eastern Brownsnake, Pseudonaja textilis, was not a wartime or post-war introduction (Serpentes, Elapidae, Hydrophiinae)

    O'Shea, Mark; Doria, Giuliano; Petri, Massimo; Kaiser, Hinrich (Museo Civico di Storia Naturelle, Genova, 2016-10-20)
    Abstract: The medically important Australian elapid Pseudonaja textilis was first documented for the island of New Guinea in the 1950s, when specimens from the northern coast of the Papuan Peninsula were collected and identified. It was initially believed that these snakes were from an invasive population that established post-World War II, a concept generally accepted over following decades. More recently molecular evidence and additional specimens, from West New Guinea and the southern coast of the Papuan Peninsula, have suggested that the New Guinea populations are indigenous. However, no pre-World War II specimens have been found to dismiss the human-mediated introduction argument. We here present the earliest known Papuan voucher specimen of P. textilis, a juvenile from collections housed in Genoa made by Luigi Maria D’Albertis in 1876 that pre-dates all other vouchers and the New Guinea Campaign (1942-1945) of World War II by 77 and 66 years, respectively. We also discuss the origins of P. textilis in New Guinea, the history of its discovery, and the Pleistocene routes of its invasion from Australia.
  • Intelligent Buildings: Key to Achieving Total Sustainability in the Built Environment

    Gadakari, T.; Mushatat, S.; Newman, R. (EPPM, 2013-06)
    ‘Are intelligent buildings a pragmatic approach towards achieving a sustainable built environment?’ is the research question that this review article aims to answer. It has been argued that there is a serious need for intelligent buildings to be evaluated against the parameters of total sustainability (environmental, economic and social) so as to help the agenda of living in a technologically advanced, healthy and comfortable world. This paper reviews existing theoretical concepts of intelligence and sustainability in the built environment, through an exploration of various scientific literature and U.S Green Building Council’s LEED (Leadership in Energy and Environmental Design) databases. A systematic qualitative review approach has been employed to select an appropriate definition of sustainable development and use it as a theoretical framework to assess the technological impact of intelligent buildings on the environmental, economic and social front. Subsequently five case study buildings from around the world, which exemplify the use of intelligent technologies to achieve sustainable gains were chosen and analyzed to further validate the literature findings. Outputs from the study highlight the various benefits of intelligent buildings, which include decrease in energy and water consumption, operational costs, as well as increase in productivity and investments. Additionally the analysis of the case studies revealed that the use of intelligent building technologies has contributed significantly towards a higher sustainability rating on the LEED rating scale. Moreover, the comparison of the attributes of intelligent buildings and sustainable practices in buildings, illustrates the fact that there is a considerable overlap between the two and intelligence can aid sustainability in the built environment. Thus the research suggests that green technologies and intelligence in combination may be a pragmatic approach towards the sustainability aspect.
  • A Case for Target Value Design towards Effective Low-Cost Housing Project Cost Management and Performance South-East Zone Nigeria

    Obi, Lovelin Ifeoma; Arif, Mohammed (IBEA Publications Ltd London, 2015)
    Reports over the past decade, reveal the trend of poor cost performances of many Low-cost Housing (LcH) projects. This have apparently resulted in huge monetary losses to the government as the client, declining housing supply and undermined affordability of many Low and Low-medium incomes particularly in developing countries like Nigeria. In spite of the changes with contemporary trends in Nigeria, it would appear that the techniques employed in the management of the delivery costs of the LcH projects particularly in the South-east zone are yet similar to those used over a century ago. This necessitates urgent and appropriate sustainable intervention strategies adopting cost-effective techniques. Prior studies affirms the implications of modern cost management techniques such as Target Value Design (TVD) in improving delivery cost performances on construction projects. For this reason this paper which forms an integral part of an ongoing doctoral study, aim to identify the efficacy and applicability of TVD in the context of LcH project delivery cost management. A review of relevant and extant literature identifies peculiarities on the concept of TVD and LcH projects. Findings from literature and data collected via questionnaires further identify constraints on current LcH project delivery cost management system and clearly indicates the possible applicability and integration of TVD in the system. These findings provide a platform for the next phase of the research towards developing an improved delivery cost management model for LcH projects. This is expected to engender effective government-led LcH projects delivery particularly in in South-East zone Nigeria.

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