Investigation into time dependant degradation and atmospheric conditions on the wettability of nylon 6,6 which has undergone CO2 laser surface modification

Modification of the wettability of polymers has been demonstrated previously; however, it is known that the wettability modifications of these materials can degrade or vary over time. This can be seen to be crucial from a commercial point of view as this would indicate that a shelf-life has to be established. But at the same time, atmospheric parameters may affect the contact angle and must therefore be accounted for as a control variable in any long-term study of wettability. In this study four CO2 laser patterned nylon 6,6 samples with differing topographical patterns and one as-received sample were analysed over a 30 week period whilst stored in ambient air. By obtaining the characteristic contact angle every two weeks it was found that the contact angle varied erratically before ultimately increasing for all samples after the 30 weeks. White light interferometry analysis determined that the laser patterning gave rise to peak heights of up to 3 μm with roughness parameters Ra and Sa of up to 0.305 and 0.408 μm, respectively. X-ray photoelectron spectroscopy found that surface oxygen content increased by up to 7 %At. It was identified that there was a significant correlation between changes in barometric air pressure and contact angle, highlighting the need for further study to determine if this is a dominant factor

Approaches to inform redevelopment of brownfield sites: an example from the Leeds area of the West Yorkshire coalfield, UK

Government-led regeneration schemes and policies encouraging the use of brownfield land present a challenge, particularly in coalfield areas. Coalfields have typically experienced multiple phases of development and can be susceptible to a suite of problematic ground conditions that may be rooted in the near-surface geology or result from anthropogenic activity. Such problems, related to the nature of void backfill, undermined and unstable ground and the presence of contaminated land in the near-surface, may deter investment in the very areas earmarked for redevelopment. An understanding of previous developments within coalfields is required to identify potential geological hazards, so that regeneration proposals include measures that address these issues. Public records of landfill and site investigations, and minerals exploration including opencast mine plans can reveal the distribution, thickness and high-level descriptions of fill materials, although the coverage of data typically precludes a comprehensive analysis of entire cities. The best way to show the spatial distribution of fill materials is currently as a two dimensional national/regional scale dataset. Depending on the distribution of data points, however, 3D modelling can be possible, which is much more detailed and accurate. Focusing on the heavily urbanised county of West Yorkshire in northern England, the assessment of opencast coal mining on the landscape and benefits of quantifying the impact are discussed. We demonstrate how certain types of publicly available data allow a greater understanding of the interaction between human activity and natural superficial and bedrock geology. If successful, this approach can help lessen the impact of delays and increased financial costs caused by unforeseen ground conditions

A hybrid strain and thermal energy harvester based on an infra-red sensitive Er3+ modified poly(vinylidene fluoride) ferroelectret structure

In this paper, a novel infra-red (IR) sensitive Er3+ modified poly(vinylidene fluoride) (PVDF) (Er-PVDF) film is developed for converting both mechanical and thermal energies into useful electrical power. The addition of Er3+ to PVDF is shown to improve piezoelectric properties due to the formation of a self-polarized ferroelectric β-phase and the creation of an electret-like porous structure. In addition, we demonstrate that Er3+ acts to enhance heat transfer into the Er-PVDF film due to its excellent infrared absorbance, which, leads to rapid and large temperature fluctuations and improved pyroelectric energy transformation. We demonstrate the potential of this novel material for mechanical energy harvesting by creating a durable ferroelectret energy harvester/nanogenerator (FTNG). The high thermal stability of the β-phase enables the FTNG to harvest large temperature fluctuations (ΔT ~ 24 K). Moreover, the superior mechanosensitivity, SM ~ 3.4 VPa−1 of the FTNG enables the design of a wearable self-powered health-care monitoring system by human-machine integration. The combination of rare-earth ion, Er3+ with the ferroelectricity of PVDF provides a new and robust approach for delivering smart materials and structures for self-powered wireless technologies, sensors and Internet of Things (IoT) devices

Визначення правового статусу садівницьких, городницьких та дачних товариств

Розкриваються особливості правового статусу садівницьких, городницьких та дач­них товариств, досліджується їх організаційно-правова форма та ті специфічні пра­вові ознаки, що знаходяться в її основі. У зв’язку з відсутністю правової бази діяль­ності цих товариств, робиться спроба сформувати основні теоретико-правові кон­цептуальні підходи до розуміння їх природи та змоделювати законодавчу схему регулювання їх діяльності.Раскрываются особенности правового статуса садоводческих, огороднических и дачных товариществ, исследуются их организационно-правовая форма и правовые особенности, составляющие ее основание. В связи с отсутствием правовых обоснований деятельности этих товариществ автор стремится сформировать основные теоре­тико-правовые концептуальные подходы к раскрытию их сущности и смоделировать законодательную схему регулирования деятельности рассматриваемых товариществ.In article features of legal status of garden, vegetable-garden and country companies reveal, their organizational legal form and those specific features that are in its basis are investigated. In connection with absence of legal base of activity of these communities is attempted to generate the basic theoretical-legal conceptual approaches to understanding of their nature and model legislative sphere of regulation of their activity becomes

Negligible evidence for regional genetic population structure for two shark species Rhizoprionodon acutus (Rüppell, 1837) and Sphyrna lewini (Griffith & Smith, 1834) with contrasting biology

Biodiversity of sharks in the tropical Indo-Pacific is high, but species-specific information to assist sustainable resource exploitation is scarce. The null hypothesis of population genetic homogeneity was tested for scalloped hammerhead shark (Sphyrna lewini, n = 237) and the milk shark (Rhizoprionodon acutus, n = 207) from northern and eastern Australia, using nuclear (S. lewini, eight microsatellite loci; R. acutus, six loci) and mitochondrial gene markers (873 base pairs of NADH dehydrogenase subunit 4). We were unable to reject genetic homogeneity for S. lewini, which was as expected based on previous studies of this species. Less expected were similar results for R. acutus, which is more benthic and less vagile than S. lewini. These features are probably driving the genetic break found between Australian and central Indonesian R. acutus (F-statistics; mtDNA, 0.751–0.903, respectively; microsatellite loci, 0.038–0.047 respectively). Our results support the spatially homogeneous monitoring and management plan for shark species in Queensland, Australia

Superconducting Vortices and Elliptical Ferromagnetic Textures

In this article an analytical and numerical study of superconducting thin film with ferromagnetic textures of elliptical geometries in close proximity is presented. The screening currents induced in the superconductor due to the magnetic texture are calculated. Close to the superconducting transition temperature $T_c$ the spontaneous creation of superconducting vortices becomes energy favorable depending on the value of the magnetization and the geometrical quantities of the magnetic texture. The creation of vortices by elliptic dots is more energy favorable than those created by circular ones. The superconductor covered by elliptic dots array exhibits anisotropic transport properties.Comment: 4 pages, 5figure

Is tagging with visual implant elastomer a reliable technique for marking earthworms?

Visual implant elastomer (VIE) has recently been employed to investigate different aspects of earthworm ecology. However, a number of fundamental questions relating to the detection and positioning of the tag, its persistence and potential effects on earthworms remain unknown. Seven earthworm species belonging to three ecological groupings, with different pigmentation and burrowing behaviour, were tagged using different coloured VIE. External inspection after two days, one week and 1, 10 and 27 months were followed by preservation, dissection and internal inspection. Tags could be seen in living specimens to 27 months, and dissection revealed that in most cases they were lodged in the coelomic cavity, held in place by septa. However, over longer time periods (more than two years), the chlorogogenous tissue tended to bind to the tags and made external observation increasingly difficult. Migration of the VIE material towards the posterior of the earthworm and potential loss of the tag were only observed on rare occasions, and a recovery rate in excess of 98% was recorded. By introducing a reasonable amount of VIE into segments, just after the clitellum, this technique can become a valuable tool in earthworm ecology and life history studies, particularly in short-medium term laboratory and field experiments

The Wadi Faynan Project, Southern Jordan: a Preliminary Report on Geomorphology and Landscape Archaeology

Reproduced with permission of the publisher. © 1997 Council for British Research in the Levant. Details of the publication are available at: http://www.cbrl.org.uk/Publications/publications_default.shtmThe Wadi Faynan Project of the British Institute at Amman for Archaeology and History (BIAAH) has as its principal objective the provision of a detailed case study in the relationship between environmental change and human history in the arid zone, from prehistory to the present day. This report describes the preliminary findings of an initial campaign of fieldwork in geomorphology and landscape archaeology conducted by an inter-disciplinary team in 1996. A preliminary sequence of fluvial events has been established, represented by the Ghuwayr and Shayqar Beds dated to the Late Pleistocene, and the Faynan and Dana Beds dated to the Holocene. Methodologies have been trialed for recording, dating and interpreting the ancient field system assumed to be of Nabataean, Roman and Byzantine date; initial findings confirm its longevity of use and complexity of purpose. There are also indications that floodwater farming began in the Wadi Faynan in the Chalcolithic or Early Bronze Ag