scholarly journals Improving the design of piles driven in chalk through the ALPACA research project

2019 ◽  
pp. 2 ◽  
Author(s):  
Richard James Jardine ◽  
Róisín Marie Buckley ◽  
Byron Walter Byrne ◽  
Stavroula Kontoe ◽  
Ross Alexander McAdam ◽  
...  
Keyword(s):  
Field Experiments ◽  
Field Testing ◽  
Field Work ◽  
Test Site ◽  
Offshore Wind ◽  
Driven Piles ◽  
Lateral Resistance ◽  
Large Numbers ◽  
Port Facilities ◽  
Set Up

Chalk is present under large areas of NW Europe as a low-density, porous, weak carbonate rock. Large numbers of offshore wind turbines, bridges and port facilities rely on piles driven in chalk. Current European practice assumes ultimate shaft resistances that appear low in comparison with the Chalk’s unconfined compression strength and CPT cone resistance ranges and can impact very significantly on project economics. Little guidance is available on pile driveability, set-up or lateral resistance in chalk, or on how piles driven in chalk can sustain axial or lateral cyclic loading. This paper describes the ALPACA (Axial-Lateral Pile Analysis for Chalk Applying multi-scale field and laboratory testing) project funded by EPSRC and Industry that is developing new design guidance through comprehensive field testing at a well-characterised low-to-medium density test site, supported by analysis of other tests. Field experiments on 36 driven piles, sixteen of which employ high resolution fibre-optic strain gauges, is supported by advanced laboratory and in situ testing, as well as theoretical analysis. The field work commenced in October 2017 and was largely complete in May 2019.

scholarly journals Effects of Malaise trap spacing on species richness and composition of terrestrial arthropod bulk samples

2020 ◽  
Author(s):  
D Steinke ◽  
TWA Braukmann ◽  
L Manerus ◽  
A Woodhouse ◽  
V Elbrecht
Keyword(s):  
Species Richness ◽  
Field Experiments ◽  
Collection Efficiency ◽  
Malaise Trap ◽  
Number Of Factors ◽  
Large Numbers ◽  
Set Up ◽  
Taxonomic Groups ◽  
A Site ◽  
Malaise Traps

AbstractThe Malaise trap has gained popularity for assessing diverse terrestrial arthropod communities because it collects large samples with modest effort. A number of factors that influence collection efficiency, placement being one of them. For instance, when designing larger biotic surveys using arrays of Malaise traps we need to know the optimal distance between individual traps that maximises observable species richness and community composition. We examined the influence of spacing between Malaise traps by metabarcoding samples from two field experiments at a site in Waterloo, Ontario, Canada. For one experiment, we used two trap pairs deployed at weekly increasing distance (3m increments from 3 to 27 m). The second experiment involved a total of 10 traps set up in a row at 3m distance intervals for three consecutive weeks.Results show that community similarity of samples decreases over distance between traps. The amount of species shared between trap pairs shows drops considerably at about 15m trap-to-trap distance. This change can be observed across all major taxonomic groups and for two different habitat types (grassland and forest). Large numbers of OTUs found only once within samples cause rather large dissimilarity between distance pairs even at close proximity. This could be caused by a large number of transient species from adjacent habitat which arrive at the trap through passive transport, as well as capture of rare taxa, which end up in different traps by chance.

The Nagra/Pnc Grimsel test site Radionuclide Migration Experiment: Rigorous Field Testing of Transport Models

1994 ◽  
Vol 353 ◽  
Author(s):  
H. Umeki ◽  
K. Hatanaka ◽  
W.R. Alexander ◽  
I.G. Mckinley ◽  
U. Frick
Keyword(s):  
Field Experiments ◽  
Field Testing ◽  
Test Site ◽  
Testing Procedure ◽  
Crystalline Rock ◽  
Radionuclide Migration ◽  
Transport Models ◽  
Geochemical Behaviour ◽  
Migration Experiment ◽  
Rigorous Model

AbstractThe long-term programme of in-situ radionuclide migration experiments in the underground test site at Grimsel (GTS) involves the development and testing of radionuclide transport models with their associated databases. The field experiments are carried out in a water-bearing shear zone in crystalline rock utilising a suite of tracers of differing geochemical behaviour. A rigorous model testing procedure has been developed for the GTS radionuclide migration experiment. This paper describes application of this testing procedure to a solute transport code developed by PNC.

scholarly journals Seasonal Influences on the Impulse Characteristics of Grounding Systems for Tropical Countries

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1334 ◽  
Author(s):  
Muhd Reffin ◽  
Abdul Abdul Ali ◽  
Normiza Mohamad Nor ◽  
Nurul Ahmad ◽  
Syarifah Abdullah ◽  
...  
Keyword(s):  
Field Experiments ◽  
Field Testing ◽  
Soil Resistivity ◽  
Tropical Countries ◽  
Power Frequency ◽  
Seasonal Influences ◽  
Set Up ◽  
Impulse Characteristics ◽  
Over Time

One of the most important parameters of the performance of grounding systems is the soil resistivity. As generally known, the soil resistivity changes seasonally, hence the performance of grounding systems, at DC and under high impulse conditions. This paper presents the performance of grounding systems with two different configurations. Field experiments were set up to study the characteristics of the grounding systems seasonally at power frequency and under high impulse conditions. A review of field testing on practical grounding systems was also presented. It was found that the soil resistivity, RDC and impulse characteristics of grounding systems were improved over time, and the improvement was higher for electrodes that have more contact with the soils.

scholarly journals Effects of Malaise trap spacing on species richness and composition of terrestrial arthropod bulk samples

2021 ◽  
Vol 5 ◽  
Author(s):  
Dirk Steinke ◽  
Thomas WA Braukmann ◽  
Laura Manerus ◽  
Allan Woodhouse ◽  
Vasco Elbrecht
Keyword(s):  
Species Richness ◽  
Field Experiments ◽  
Collection Efficiency ◽  
Malaise Trap ◽  
Number Of Factors ◽  
Large Numbers ◽  
Set Up ◽  
Taxonomic Groups ◽  
A Site ◽  
Malaise Traps

The Malaise trap is a popular device for assessing diverse terrestrial arthropod communities because it collects large samples with modest effort. A number of factors influence its collection efficiency, placement being one of them. For instance, when designing larger biotic surveys using arrays of Malaise traps we need to know the optimal distance between individual traps that maximises observable species richness and community composition. We examined the influence of spacing between Malaise traps by metabarcoding samples from two field experiments at a site in Waterloo, Ontario, Canada. For one experiment, we used two trap pairs deployed at weekly increasing distances (3 m increments from 3 to 30 m). The second experiment involved a total of 10 traps set up in a row at 3 m distance intervals for three consecutive weeks. Results show that community similarity of samples decreases over distance between traps. The amount of species shared between trap pairs drops considerably at about 18 m trap-to-trap distance. This change can be observed across all major taxonomic groups and for two different habitat types (grassland and forest). Large numbers of OTUs found only once within samples cause rather large dissimilarity between distance pairs even at close proximity. This could be caused by a large number of transient species from adjacent habitats which arrive at the trap through passive transport, as well as capture of rare taxa, which end up in different traps by chance.

Field Study on the Effects of Impact Frequency on the Axial and Lateral Capacity of Driven Pipe Piles in Sand

2018 ◽  
Author(s):  
Ivana Anusic ◽  
Barry M. Lehane ◽  
Gudmund R. Eiksund ◽  
Morten A. Liingaard
Keyword(s):  
Test Site ◽  
Driven Piles ◽  
Impact Frequency ◽  
Static Tests ◽  
Lateral Capacity ◽  
Load Tests ◽  
Loading Tests ◽  
Set Up ◽  
Lateral Behavior ◽  
The Impact

With pile installation being an important part of the total project cost, improving the efficiency of the offshore operations would require resolving the uncertainties in how different installation methods influence pile capacity. This paper describes a programme of testing involving static loading tests on eight 165 mm diameter open-ended steel tubes driven into medium dense siliceous sand at a well-characterized test site in Perth, Western Australia. Six piles were installed by impact driving under two different driving frequencies, and two piles were installed by vibration with the aim of identifying the effects of impact frequency on the response of driven piles to static axial and lateral loading. It was found that the tension capacity of piles measured 1 week after installation was not significantly dependent on the impact frequency and that these piles had approximately the same capacity as the piles installed by vibration. First time load tests performed 4 months after the initial tests indicated that all pile types had a similar set-up characteristic. Inspection of static tests on lateral behavior of vibrated and impact driven piles suggests that installation method has no impact on the lateral capacity.

Prediction of root damaging during mechanical shaking of fruit trees

2014 ◽  
Vol 10 (1) ◽  
pp. 1-15
Author(s):  
Z. Láng
Keyword(s):  
Field Experiments ◽  
Calculated Data ◽  
Fruit Trees ◽  
List Type ◽  
Structure Model ◽  
Root Damage ◽  
Set Up ◽  
Simple Tree ◽  
The Given ◽  
Cherry Trees

The possible effect of shaker harvest on root damage of 10-year-old cherry trees was studied on a simple tree structure model. The model was composed of elastic trunk and rigid main roots, the ends of which were connected to the surrounding soil via springs and dumping elements. Equations were set up to be able to calculate the relation between shaking height on the trunk and strain in the roots. To get the data for root break and their elongation at different shaking heights on the trunk, laboratory and field experiments were carried out on cherry trees and on their roots. Having evaluated the measured and calculated data it could be concluded that root damage is to be expected even at 3.6% strain and the risk of it increases with increased trunk amplitudes, i.e.with the decrease of shaking heightat smaller stem diameters (i.e. in younger plantation), andif the unbalanced mass of the shaker machine is too large for the given tree size.

Qaanaaq 2001: mineral exploration reconnaissance in North-West Greenland

2002 ◽  
pp. 133-143
Author(s):  
Bjørn Thomassen ◽  
Peter R. Dawes ◽  
Agnete Steenfelt ◽  
Johan Ditlev Krebs
Keyword(s):  
Mineral Exploration ◽  
Mining Industry ◽  
Field Work ◽  
Original Series ◽  
West Greenland ◽  
North West ◽  
Ice Caps ◽  
High Plateau ◽  
Set Up ◽  
Inland Ice

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Thomassen, B., Dawes, P. R., Steenfelt, A., & Krebs, J. D. (2002). Qaanaaq 2001: mineral exploration reconnaissance in North-West Greenland. Geology of Greenland Survey Bulletin, 191, 133-143. https://doi.org/10.34194/ggub.v191.5141 _______________ Project Qaanaaq 2001, involving one season’s field work, was set up to investigate the mineral occurrences and potential of North-West Greenland between Olrik Fjord and Kap Alexander (77°10´N – 78°10´N; Fig. 1). Organised by the Geological Survey of Denmark and Greenland (GEUS) and the Bureau of Minerals and Petroleum (BMP), Government of Greenland, the project is mainly funded by the latter and has the overall goal of attracting the interest of the mining industry to the region. The investigated region – herein referred to as the Qaanaaq region – comprises 4300 km2 of ice-free land centred on Qaanaaq, the administrative capital of Qaanaap (Thule) municipality. Much of the region is characterised by a 500–800 m high plateau capped by local ice caps and intersected by fjords and glaciers. High dissected terrain occurs in Northumberland Ø and in the hinterland of Prudhoe Land where nunataks are common along the margin of the Inland Ice.

scholarly journals Effects of disk tillage on soil condition, crop yield and weed infestation

2011 ◽  
Vol 48 (No. 1) ◽  
pp. 20-26
Author(s):  
M. Birkás ◽  
T. Szalai ◽  
C. Gyuricza ◽  
M. Gecse ◽  
K. Bordás
Keyword(s):  
Winter Wheat ◽  
Crop Yield ◽  
Field Experiments ◽  
Soil Layer ◽  
Soil Condition ◽  
Perennial Weeds ◽  
Weed Infestation ◽  
Set Up ◽  
Different Levels

This research was instigated by the fact that during the last decade annually repeated shallow disk tillage on the same field became frequent practice in Hungary. In order to study the changes of soil condition associated with disk tillage and to assess it is consequences, long-term tillage field experiments with different levels of nutrients were set up in 1991 (A) and in 1994 (B) on Chromic Luvisol at Gödöllö. The effects of disk tillage (D) and disk tillage combined with loosening (LD) on soil condition, on yield of maize and winter wheat, and on weed infestation were examined. The evaluation of soil condition measured by cone index and bulk density indicated that use of disking annually resulted in a dense soil layer below the disking depth (diskpan-compaction). It was found, that soil condition deteriorated by diskpan-compaction decreased the yield of maize significantly by 20 and 42% (w/w), and that of wheat by 13 and 15% (w/w) when compared to soils with no diskpan-compaction. Averaged over seven years, and three fertilizer levels, the cover % of the total, grass and perennial weeds on loosened soils were 73, 69 and 65% of soils contained diskpan-compaction.

scholarly journals A SCALABLE HYBRID FPGA/GPU FX CORRELATOR

2014 ◽  
Vol 03 (01) ◽  
pp. 1450002 ◽  
Author(s):  
J. KOCZ ◽  
L. J. GREENHILL ◽  
B. R. BARSDELL ◽  
G. BERNARDI ◽  
A. JAMESON ◽  
...  
Keyword(s):  
Graphics Processing Units ◽  
Field Testing ◽  
Outer Product ◽  
Gate Arrays ◽  
Large Numbers ◽  
Field Programmable ◽  
Programmable Gate Arrays ◽  
Hybrid Fpga ◽  
Graphics Processing ◽  
O 10

Radio astronomical imaging arrays comprising large numbers of antennas, O(102–103), have posed a signal processing challenge because of the required O (N2) cross correlation of signals from each antenna and requisite signal routing. This motivated the implementation of a Packetized Correlator architecture that applies Field Programmable Gate Arrays (FPGAs) to the O (N) "F-stage" transforming time domain to frequency domain data, and Graphics Processing Units (GPUs) to the O (N2) "X-stage" performing an outer product among spectra for each antenna. The design is readily scalable to at least O(103) antennas. Fringes, visibility amplitudes and sky image results obtained during field testing are presented.

scholarly journals Precision geoinformatical system of the pear gene-collection orchard

2012 ◽  
Vol 18 (1) ◽  
Author(s):  
J. Tamás ◽  
A. Nagy ◽  
T. Fórián ◽  
J. Nyéki ◽  
T. Szabó ◽  
...  
Keyword(s):  
Data Base ◽  
Spatial Data ◽  
Single Species ◽  
Field Work ◽  
Stress Sensitivity ◽  
Hyperspectral Data ◽  
Data Cube ◽  
The Sustainable Development ◽  
Fruit Species ◽  
Set Up

The principle task of the sustainable development is the preservation of the genetic variety, which is similar challenge in the horticulture regarding the sublimation of fruit species. The breeders of the traditional fruit strains give stock to the sustenance diversity of the agro-environment on the species and landscape level. In 2009, hyperspectral images have been taken by AISA Dual sensors from the pear gene pool in Újfehértó, Hungary. The hyperspectral data cube (in the wavelength range of 400-2500 nm, with 1.5 m ground resolution) ensured possibility to make the spectral library of pear species. In the course of the simultaneously field work the spatial position and individual extent of all pear trees was defined to set up a detailed GIS data base. The water stress sensitivity of single species and the descriptive spectral curves were determined with common evaluation of the spectral and spatial data. Based on the unique methodology processing and the hyperspectral data base suitable strains can be chosen for agro-environment and let take adaptive stocks regarding climate change into the genetic grafting work. Furthermore we could determine and map the sparsely species in the region with the help of the hyperspectral data.

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