155 research outputs found
Geomorphological insight into changing tectonic regime, Pasinler Basin, Turkey
No full textThe Pasinler Basin, in the East Anatolian Contractional Province, features a suite of
geomorphological zones, visible in the field, air photographs and Landsat and SRTM
DEM imagery. These zones reflect past and current tectonically influenced processes.
Collins et al: Geomorphological insight into changing tectonic regime, Pasinler Basin, Turkey. 2 of 26
Remnants of the Erzurum-Kars plateau representing Mio-Pliocene volcanism,
associated with transtensional tectonics, have been modified by two stages of drainage
development: an earlier, shallow valley network, which was modified following uplift and
tilting to form the present system characterised by deep narrow valleys that supply
alluvial fan complexes. These fans discharge onto the present, aggradation-dominated
basin floor. Initial normal faulting induced massive slope failures on the basin’s northern
margin. This extensional phase within the basin was reversed by the Late Pleistocene,
with thrust faults modifying and producing landforms, and affecting sediment sequences,
along both the north and south basin margins. The shift from a transtensional regime
and associated volcanism to normal faulting in the Pliocene-Early Pleistocene, and then
to the present compression-dominated regime appears to correspond with regional
tectonic changes resulting from collision of the Arabian microplate and the subsequent
westward movement of the Anatolian microplate
Comparison of Photo ElectroFenton Process(PEF) and combination of PEF Process and Membrane Bioreactor in the treatment of Landfill Leachate
No full textAbstractLandfill leachate treatment is an integral part of municipal solid waste management. The conventional biological treatment of landfill leachate is limited because of the presence of toxic contaminants and recalcitrant organics. Among Advanced Oxidation processes(AOPs), Photo Electro Fenton Process(PEF) can be used effectively for the treatment of highly contaminated water. In the treatment of leachate by biological methods, Membrane Bioreactor(MBR) is efficient while considering the effluent quality. So a combination of PEF followed by MBR treatment is adopted in this study. The percentage removal of pollutants -TSS, BOD,COD, Ammonia Nitrogen, Phosphate, Sulphate, Sulphide and Chloride from landfill leachate after PEF process is 89.3,71.9,83.6,100,58,92.3,65 and 65 respectively. The percentage removal of the same pollutant parameters after combined treatment of PEF followed by MBR is 95.5,90.2,96.2,100,82.7,93.3,88.2 and 88.3. The pollutant removal efficiency is increased by adopting combined treatment –PEF followed by MBR
Assumptions and reality in ground models - the case of drift-filled hollows and associated subsurface features in London, United Kingdom
No full textCopyright © 2023 The Author(s), The subsurface of London is often assumed to be relatively simple, with Late Cretaceous and Palaeogene strata sitting within and forming a synclinal structure (the London Basin). The surface has been modified by mostly fluvial processes during the Quaternary.
More recently, a picture of more complex conditions has begun to be developed, largely driven by the need for deeper foundations, groundwater control and tunnelling. One group of significant features are referred to as ‘drift-filled hollows’ (DFH). These are commonly closed depressions in the surface of the bedrock (typically the London Clay Formation), that are infilled by later deposits. Adjacent and underlying strata is sometimes disturbed
A new database shows that DFH are more widespread than previously thought, but also highlights issues in how they are classified. It also raises questions about the validity of the ‘simple’ geological model of London and highlights the danger of using assumptions when planning development, and for reconstructing past events
Fluvial stratigraphy and palaeoenvironments in the Pasinler Basin, eastern Turkey
No full textValley floor sediments from the Pasinler Basin, eastern Turkey, provide evidence for Pleistocene and Holocene floodplain conditions. Three terrace surfaces are present. Evidence for tectonic processes active during the Late Neogene are widespread within the basin but do not appear to have substantially influenced the detail of the Holocene palaeoenvironmental record. Significant changes in hydrology are recorded, with more stable floodplain conditions occurring at around 9,000, 5,500 and 4,000 cal. yr. BP. Incision occurred sometime after approximately 4,000 BP, probably as a response to dual climatic and human controls. Comparisons with key sites in the Anatolian region and beyond suggest these changes are part of a regional climatic pattern, perhaps influenced by changes in the East African Monsoon. Differences in the details of the records across the region reflect the characteristics of the local environment, which, increasingly in the latter Holocene, includes human activity
PEF-SEURANTAMITTAUKSEN OHJAAMINEN: OHJE HOITOTYÖN OPISKELIJOILLE JA HOITOHENKILÖKUNNALLE
No full textPEF tarkoittaa uloshengityksen huippuvirtausta eli sitä, kuinka kovaa ihminen pystyy mittaushetkellä hetkellisesti parhaimmillaan puhaltamaan ilmaa ulos keuhkoistaan. Tutkimusten perusteella tiedetään, että PEF-seurannan onnistumiseen vaaditaan hyvää potilaan ohjausta.
Tämän toiminnallisen opinnäytetyön tarkoituksena oli tuottaa hoitotyön opiskelijoille ja hoitohenkilökunnalle ohje potilaan ohjaamiseen PEF-puhallusmittaustilannetta sekä kotiseurantaa varten. Ohje on tarkoitettu käytettäväksi mahdollisen astman diagnosoinnissa tehtävän kotiseurantamittauksen opettamisessa.
Opinnäytetyön tekijän ohjatun harjoittelun aikana terveysasemalla kävi ilmi, että PEF-mittauksen ohjauksen onnistumisessa oli huomattavia eroja. Tästä syntyi idea opinnäytetyötä varten. Opinnäytetyön tilaajana oli Vaasan ammattikorkeakoulu.
Teoreettisessa viitekehyksessä käsitellään PEF-puhallusmittausta, potilasohjausta ja ohjauksen merkitystä PEF-mittauksessa. Ohjeen suunnittelussa on hyödynnetty teoreettisessa viitekehyksessä esitettyä tietoa opetusmenetelmistä sekä PEF-seurantamittauksen suorittamisesta. Ohjeen suunnitteluun osallistui opinnäytetyön tekijän lisäksi työelämän yhteyshenkilö Vaasan ammattikorkeakoulusta. Opinnäytetyö toteutettiin projektina, jonka etenemisen vaiheet esitetään raportissa.
Projektissa tuotettua ohjetta ei ole vielä testattu käytännössä. Työn tilaaja on kuitenkin hyväksynyt valmiin tuotteen ja sen toimivuutta voidaan arvioida tulevaisuudessa.PEF stands for peak expiratory flow, which is the peak of how fast a person can exhale air out of the lungs. Based on the previous research it is known that a successful PEF-monitoring requires a good patient guidance.
The purpose of this practice-based bachelor´s thesis was to produce a manual on patient education in a PEF-measuring situation and for home monitoring for nursing students and staff. The manual is meant to be used for teaching patients home monitoring when diagnosing potential asthma.
During a clinical placement period performed by the author of this bachelor´s thesis in a health clinic, it became obvious that there were significant differences in the success rate when educating patients in PEF-monitoring. An idea for the bachelor´s thesis was born from this. This thesis was ordered by the university of applied sciences in Vaasa.
The theoretical framework deals with PEF-measurement, patient education and the significance of patient education in PEF-measurement. When contemplating the manual, the presented content in the theoretical framework regarding teaching methods and PEF-monitoring measurement was utilized.
Besides of the author of this bachelor´s thesis a working life contact person from the university of applied sciences was also involved in the process of planning and making the manual. The bachelor´s thesis was executed as a project and the different phases are presented in the report.
The manual produced in the project has not yet been tested in practice. The client has however approved the finished product, the functionality can be assessed in the future
The dendroclimatology of modern and neolithic scots pine (Pinus sylvestris l.) in the peatlands of northern Scotland
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.For the first time in northern Scotland, Modern tree-ring chronologies for Scots pine growing on peat are compared against those growing on mineral substrates. Mean tree-ring growth of pine on active bogs/mires is found to be limited to 0.5 to 1 mm yr-1, compared to ≥1.5 mm yr-1 on adjacent mineral sites. Almost instant change of radial growth rates in response to changes in water levels highlights the potential use of pine in reconstructions of lake levels and water tables in bog and mire. Dendroclimatological analysis identifies January and February temperatures to often be more important than summer temperature. Positive correlation of ring-width and North Atlantic Oscillation (NAO) indices also occur in January and February. Lower winter temperatures, due to increased altitude and distance from the moderating effects of the ocean, may be important in limiting tree growth near its northern margin. Moving correlation functions identify a widespread reduction in the response of pine growing on both substrates from the 1920s.
Nine subfossil pine site chronologies located beyond the species current northern limit are cross-matched to form a chronology called WRATH-9. This chronology is tentatively crossdated against Irish pine chronologies to provide the first picture of Neolithic Scots pines 200 year expansion from c. 3200 BC and subsequent 250 year retreat across northern Scotland at annual resolution.
The mean orientation of maximum radial growth at eleven modern pine sites is found to coincide well with the W/SW prevailing wind, suggesting Scots pine may provide a good proxy indicator of wind. Six coeval Neolithic sites indicate a broadly consistent northerly prevailing wind. This provides tentative evidence for a change of prevailing wind that may be related to a southward incursion of the polar front in the eastern N. Atlantic. The potential of this exciting subfield of dendroclimatological analysis is called dendroaeology and is highlighted for further research
Modelling the brittle rock failure by the quaternion-based bonded-particle model in DEM
No full textA CC BY or equivalent licence is applied to that at least the Author Accepted Manuscript (AAM) arising from this submission, in accordance with the grant's open access conditions. The research data are publicly available online at: https://doi.org/10.17633/rd.brunel.25117811.This paper presents an investigation of brittle rock failure by the quaternion-based bonded-particle model in discrete element method (DEM). Unlike traditional approaches that utilize Euler angles or rotation matrices, this model employs unit quaternions to represent the spatial rotations of particles. This method simplifies the representation of 3D rotations, providing a more intuitive framework for modelling complex interactions in granular materials. The numerical model was validated by the uniaxial compression tests on rock, with good agreement with well-documented experimental data in terms of the rock uniaxial compression strength (UCS) and failure mode. During loading, the rock sample demonstrated a linear-elastic response at an axial strain of smaller than 0.45%. However, as internal bond breakage accumulated, this linear relationship weakened, and the stress-strain curve began to deviate from its initial linear trajectory. The bond breakage and the overall deformation of the rock were primarily controlled by the shear bonding force. The UCS was achieved at an axial strain of 0.625%, at which point the internal shear bonding force chains were predominantly aligned vertically. The brittle failure occurred when the internal damage of solids nucleated to form an interconnected failure plane, accompanied by a sharp rise in the internal damage ratio. The area of failure plane increased with the loading strain rate, gradually transforming the failure pattern from the local damage to a complete fragmentation.This research was supported by the UK Engineering and Physical Sciences Research Council (EPSRC) New Investigator Award (Grant No. EP/V028723/1) and the Royal Society, Sino-British Fellowship Trust International Exchanges Award (No. IES∖R2∖202023)
Floodplain environmental change during the younger dryas and holocene: Evidence from the lower kennet valley, south central England
No full textMany lowland rivers across northwest Europe exhibit broadly similar behavioural responses to glacial-interglacial transitions and landscape development. Difficulties exist in assessing these, largely because the evidence from many rivers remains limited and fragmentary. Here we address this issue in the context of the river Kennet, a tributary of the Thames, since c. 13,000 cal. BP). Some similarities with other rivers are present, suggesting that regional climatic shifts are important controls. The Kennet differs from the regional pattern in a number of ways. The rate of response to sudden climatic change, particularly at the start of the Holocene and also mid-Holocene forest clearance, appears very high. This may reflect abrupt shifts between two catchment scale hydrological states arising from contemporary climates, land use change and geology. Stadial hydrology is dominated by nival regimes, with limited winter infiltration and high spring and summer runoff. Under an interglacial climate, infiltration is more significant. The probable absence of permafrost in the catchment means that a lag between the two states due to its gradual decay is unlikely. Palaeoecology, supported by radiocarbon dates, suggests that, at the very start of the Holocene, a dramatic episode of fine sediment deposition across most of the valley floor occurred, lasting 500-1000 years. A phase of peat accumulation followed as mineral sediment supply declined. A further shift led to tufa deposition, initially in small pools, then across the whole floodplain area, with the river flowing through channels cut in tufa and experiencing repeated avulsion. Major floods, leaving large gravel bars that still form positive relief features on the floodplain, followed mid-Holocene floodplain stability. Prehistoric deforestation is likely to be the cause of this flooding, inducing a major environmental shift with significantly increased surface runoff. Since the Bronze Age, predominantly fine sediments were deposited along the valley with apparently stable channels and vertical floodplain accretion associated with soil erosion and less catastrophic flooding. The Kennet demonstrates that, while a general pattern of river behaviour over time, within a region, may be identifiable, individual rivers are likely to diverge from this. Consequently, it is essential to understand catchment controls, particularly the relative significance of surface and subsurface hydrology
Evaluation of frost heave and moisture/chemical migration mechanisms in highway subsoil using a laboratory simulation method
No full textSeasonal processes in cold countries significantly affect the engineering characteristics of highway subsoil over time. Cyclical freeze-thaw leads to changes in thermal and moisture conditions. As a result, road bearing capacity can progressively change from the initial design. In this work, a modified laboratory method was developed, with cyclical freeze-thaw of soil samples and simultaneous supply of deionised water and a de-icing agent (sodium chloride) to the base. The benefits of the test procedure included slow freezing, simulating the conditions that can be experienced by highway soils in cold environments, extended soil column heights and a larger number of identical soil samples, which allowed experimental variability to be assessed. The method included the monitoring of moisture and chemical mass transfer in the soils. Samples supplied with deionised water experienced ice segregation in their upper parts, and significant heave. While soils supplied with NaCl solution behaved in a similar fashion during their first freeze-thaw cycle, the second cycle saw a reduction in the rate of migration of the freezing front within the soils and also less ice segregation and less heave due to increased salinity. Salt was preferentially transferred upwards in the soil columns as a result of the thermal gradient, including negative pressure associated with cryosuction, and osmotic pressure. The new method provides a more realistic laboratory approach to assessing potential freeze-thaw impacts, and the effects of de-icing agents on soils beneath roads, and in different settings.JSC Center (International program “Bolashak”)
Disentangling the effects of electroporation and heat during pulsed electric field (PEF) processing of oat-based milk alternative: A case study on Lactiplantibacillus plantarum inactivation
No full textThe study aimed to quantify the resistance of two L. plantarum strains and estimate the contribution of temperature during the pulsed electric field (PEF) processing of oat beverage. PEF and thermal inactivation kinetic experiments of L. plantarum strains were performed separately. Log10 reductions ≥5.7 of L. plantarum was achieved when 10–24 kV/cm, 110–115 kJ/L, 80–522 μs, and 35 °C inlet temperature were applied, while strain variability was evident in the performed assessments. Accurate monitoring of the temperature profiles for PEF allowed the estimation of the thermal microbial inactivation which was separated from electroporation effect. The electroporation impact was found to increase with increasing electric field strengths. Temperature measurements in the treatment zone confirmed the presence of hot spots. At higher specific energy inputs, there was significant contribution of temperature to the total observed inactivation. This contribution became smaller when the flow rate was increased, as shorter residence time reduced the exposure to high temperature peaks. Industrial relevance: The findings demonstrated the potential of PEF as a promising technology for the microbial decontamination of oat-based milk alternative. Knowledge of strain variability in response to emerging food processing technologies is critical during process optimisation and quantitative microbial risk assessment. New developments in PEF equipment and process should ideally aim to maximize inactivation while minimizing the impact of high temperature on sensitive food constituents. © 2024 The Author
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