Detection of subbottom ice‐bonded permafrost on the Canadian Beaufort Shelf by ground electromagnetic measurements

Geophysics ◽  
1992 ◽  
Vol 57 (11) ◽  
pp. 1419-1427 ◽  
Author(s):  
G. J. Palacky ◽  
L. E. Stephens

Accurate knowledge of the location of subbottom ice‐bonded permafrost is essential in planning major infrastructure projects such as pipelines in the Arctic. A combination of refraction and shallow reflection seismic surveys and drilling has been considered the most effective means of permafrost detection in offshore environments. Field experiments recently carried out on the Beaufort Shelf by the Geological Survey of Canada indicate that multifrequency horizontal‐loop electromagnetic (HLEM) measurements are a fast and cost‐effective alternative. During test surveys, 60 to 80 soundings were completed in a day. Analysis of HLEM field data shows that a four‐layer model is appropriate for the local geologic conditions. The first layer in the model, sea ice, is highly resistive (5000 Ω ⋅ m). The second layer consists of seawater and seawater‐saturated sediments (estimated resistivity 1 Ω ⋅ m). Because their true resistivities are not significantly different, it was not possible to separate the two highly conductive layers by inversion. The target of the survey, subbottom ice‐bonded permafrost, was the third layer in the section (resistivity 5000 Ω ⋅ m). The bottom layer is formed by unfrozen sediments (average resistivity 2 Ω ⋅ m). Comparison with seismic and drilling results indicates that detection of ice‐bonded permafrost by the HLEM method is reliable; the outlines of its upper boundary given by seismic and HLEM measurements are in good agreement. At the only borehole available, unconstrained inversion of HLEM data provided an accurate estimate of permafrost depth and thickness, but there is not enough drilling information to objectively assess the reliability of the technique.

Author(s):  
O. A. Demydov ◽  
A. A. Siroshtan ◽  
V. P. Kavunets ◽  
O. A. Zaima ◽  
S. F. Liskovskiy

Introduction. High-quality varietal seeds, which can ensure a gain of 0.2–0.4 t/ha in the yields from their offspring, is one of the most important and cost-effective means to increase the gross grain collection of grain. Purpose. To study productive capacities of spring wheat seeds depending on treatment of fields with fungicides and insecticides. Materials and methods. The following indicators were evaluated: swelling activity, germination energy, laboratory germinability, initial growth strength, coleoptile length and the number of radicles. Seed samples that after pesticide treatment had showed the best results were tested in field experiments for productive capacities. The experimental plot area was 10 m2, in six replications. Seeds were sown with a seeder SN-10Ts after soybean with a seeding rate of 5 million germinable seeds per hectare. Spring wheat seeds produced in the experimental plots, which were treated with fungicides Akula (0.6 L/ha) and Soligor 425 EC (0.6 L/ha) and insecticides Fas (0.15 L/ha) and Karate Zeon 050 CS (0.15 L/ha) in organogenesis stages VI, VIII and X, were evaluated for productive capacities. The study was carried out on varieties MIP Zlata, Bozhena, MIP Raiduzhna and Diana. Results and discussion. Over the study years, the gain in the yields of spring wheat varieties grown from seeds of fungicide-treated plants was 0.23–0.36 t/ha; the gain in the yields of spring wheat varieties grown from seeds of insecticide-treated plants was – 0.24-0.31 t/ha. Pesticide-treated parental plants produced seeds with increased productive capacities: when such seeds were sown, the field germinability increased by 3-5%, and the plant survival – by 5-7%. Conclusions. The results indicate that the treatment of vegetating plants of spring wheat varieties in seed plots with fungicides and insecticides is a reliable way to obtain seeds with high productive capacities


2019 ◽  
Author(s):  
Michael Moritz Pollock ◽  
Shari Witmore ◽  
Erich Yokel

ABSTRACTAcross Eurasia and North America, beaver (Castor spp), their dams and their human-built analogues are becoming increasingly common restoration tools to facilitate recovery of streams and wetlands, providing a natural and cost-effective means of restoring dynamic fluvial ecosystems. Although the use of beaver ponds by numerous fish and wildlife species is well documented, debate continues as to the benefits of beaver dams, primarily because dams are perceived as barriers to the movement of fishes, particularly migratory species such as salmonids. In this study, through a series of field experiments, we tested the ability of juvenile salmonids to cross constructed beaver dams (aka beaver dam analogues). Two species, coho salmon (Oncorhynchus kisutch) and steelhead trout (O. mykiss), were tracked using passive integrated transponder tags (PIT tags) as they crossed constructed beaver dams. We found that when we tagged and moved late-summer parr from immediately upstream of the dams to immediately downstream of them, most of them were detected upstream within 36 hours of displacement. By the end of a 21-day field experiment, 91% of the displaced juvenile coho and 54% of the juvenile steelhead trout were detected on antennas upstream of the dams while <1% of the coho and 15% of the steelhead trout were detected on antennas in the release pool below the dams. A similar but shorter 4-day pilot experiment with only steelhead trout produced similar results. In contrast, in a non-displacement experiment, juveniles of both species that were captured, tagged and released in a pool 50 m below the dams showed little inclination to move upstream. Finally by measuring hydraulic conditions at the major flowpaths over and around the dams, we provide insight into conditions under which juvenile salmonids are able to cross these constructed beaver dams, which should help guide future restoration efforts.


2020 ◽  
pp. 1192-1198
Author(s):  
M.S. Mohammad ◽  
Tibebe Tesfaye ◽  
Kim Ki-Seong

Ultrasonic thickness gauges are easy to operate and reliable, and can be used to measure a wide range of thicknesses and inspect all engineering materials. Supplementing the simple ultrasonic thickness gauges that present results in either a digital readout or as an A-scan with systems that enable correlating the measured values to their positions on the inspected surface to produce a two-dimensional (2D) thickness representation can extend their benefits and provide a cost-effective alternative to expensive advanced C-scan machines. In previous work, the authors introduced a system for the positioning and mapping of the values measured by the ultrasonic thickness gauges and flaw detectors (Tesfaye et al. 2019). The system is an alternative to the systems that use mechanical scanners, encoders, and sophisticated UT machines. It used a camera to record the probe’s movement and a projected laser grid obtained by a laser pattern generator to locate the probe on the inspected surface. In this paper, a novel system is proposed to be applied to flat surfaces, in addition to overcoming the other limitations posed due to the use of the laser projection. The proposed system uses two video cameras, one to monitor the probe’s movement on the inspected surface and the other to capture the corresponding digital readout of the thickness gauge. The acquired images of the probe’s position and thickness gauge readout are processed to plot the measured data in a 2D color-coded map. The system is meant to be simpler and more effective than the previous development.


2011 ◽  
Vol 39 (3) ◽  
pp. 193-209 ◽  
Author(s):  
H. Surendranath ◽  
M. Dunbar

Abstract Over the last few decades, finite element analysis has become an integral part of the overall tire design process. Engineers need to perform a number of different simulations to evaluate new designs and study the effect of proposed design changes. However, tires pose formidable simulation challenges due to the presence of highly nonlinear rubber compounds, embedded reinforcements, complex tread geometries, rolling contact, and large deformations. Accurate simulation requires careful consideration of these factors, resulting in the extensive turnaround time, often times prolonging the design cycle. Therefore, it is extremely critical to explore means to reduce the turnaround time while producing reliable results. Compute clusters have recently become a cost effective means to perform high performance computing (HPC). Distributed memory parallel solvers designed to take advantage of compute clusters have become increasingly popular. In this paper, we examine the use of HPC for various tire simulations and demonstrate how it can significantly reduce simulation turnaround time. Abaqus/Standard is used for routine tire simulations like footprint and steady state rolling. Abaqus/Explicit is used for transient rolling and hydroplaning simulations. The run times and scaling data corresponding to models of various sizes and complexity are presented.


Author(s):  
Tochukwu Moses ◽  
David Heesom ◽  
David Oloke ◽  
Martin Crouch

The UK Construction Industry through its Government Construction Strategy has recently been mandated to implement Level 2 Building Information Modelling (BIM) on public sector projects. This move, along with other initiatives is key to driving a requirement for 25% cost reduction (establishing the most cost-effective means) on. Other key deliverables within the strategy include reduction in overall project time, early contractor involvement, improved sustainability and enhanced product quality. Collaboration and integrated project delivery is central to the level 2 implementation strategy yet the key protocols or standards relative to cost within BIM processes is not well defined. As offsite construction becomes more prolific within the UK construction sector, this construction approach coupled with BIM, particularly 5D automated quantification process, and early contractor involvement provides significant opportunities for the sector to meet government targets. Early contractor involvement is supported by both the industry and the successive Governments as a credible means to avoid and manage project risks, encourage innovation and value add, making cost and project time predictable, and improving outcomes. The contractor is seen as an expert in construction and could be counter intuitive to exclude such valuable expertise from the pre-construction phase especially with the BIM intent of äóÖbuild it twiceäó», once virtually and once physically. In particular when offsite construction is used, the contractoräó»s construction expertise should be leveraged for the virtual build in BIM-designed projects to ensure a fully streamlined process. Building in a layer of automated costing through 5D BIM will bring about a more robust method of quantification and can help to deliver the 25% reduction in overall cost of a project. Using a literature review and a case study, this paper will look into the benefits of Early Contractor Involvement (ECI) and the impact of 5D BIM on the offsite construction process.


Alloy Digest ◽  
1980 ◽  
Vol 29 (11) ◽  

Abstract JS777 is a high-alloy, fully austenitic stainless steel developed for applications where corrosive conditions are too severe for the standard grades of stainless steel. It also provides a cost-effective alternative to more expensive nickel-base and titanium-base alloys. It has relatively high resistance to stress-corrosion cracking and to intergranular corrosion. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-377. Producer or source: Jessop Steel Company.


Alloy Digest ◽  
2009 ◽  
Vol 58 (11) ◽  

Abstract Ancorsteel 4300 alloy ferrous powder simulates wrought steel compositions and is a cost-effective alternative to alloys requiring secondary processing. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fracture toughness. It also includes information on heat treating and powder metal forms. Filing Code: SA-611. Producer or source: Hoeganaes Corporation.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 119-120
Author(s):  
N. Østerås ◽  
E. Aas ◽  
T. Moseng ◽  
L. Van Bodegom-Vos ◽  
K. Dziedzic ◽  
...  

Background:To improve quality of care for patients with hip and knee osteoarthritis (OA), a structured model for integrated OA care was developed based on international treatment recommendations. A previous analysis of a cluster RCT (cRCT) showed that compared to usual care, the intervention group reported higher quality of care and greater satisfaction with care. Also, more patients were treated according to international guidelines and fulfilled recommendations for physical activity at the 6-month follow-up.Objectives:To assess the cost-utility of a structured model for hip or knee OA care.Methods:A cRCT with stepped-wedge cohort design was conducted in 6 Norwegian municipalities (clusters) in 2015-17. The OA care model was implemented in one cluster at the time by switching from “usual care” to the structured model. The implementation of the model was facilitated by interactive workshops for general practitioners (GPs) and physiotherapists (PTs) with an update on OA treatment recommendations. The GPs explained the OA diagnosis and treatment alternatives, provided pharmacological treatment when appropriate, and suggested referral to physiotherapy. The PT-led patient OA education programme was group-based and lasted 3 hours followed by an 8–12-week individually tailored resistance exercise programme with twice weekly 1-hour supervised group sessions (5–10 patients per PT). An optional 10-hours Healthy Eating Program was available. Participants were ≥45 years with symptomatic hip or knee OA.Costs were measured from the healthcare perspective and collected from several sources. Patients self-reported visits in primary healthcare at 3, 6, 9 and 12 months. Secondary healthcare visits and joint surgery data were extracted from the Norwegian Patient Register. The health outcome, quality-adjusted life-year (QALY), was estimated based on the EQ-5D-5L scores at baseline, 3, 6, 9 and 12 months. The result of the cost-utility analysis was reported using the incremental cost-effectiveness ratio (ICER), defined as the incremental costs relative to incremental QALYs (QALYs gained). Based on Norwegian guidelines, the threshold is €27500. Sensitivity analyses were performed using bootstrapping to assess the robustness of reported results and presented in a cost-effectiveness plane (Figure 1).Results:The 393 patients’ mean age was 63 years (SD 9.6) and 74% were women. 109 patients were recruited during control periods (control group), and 284 patients were recruited during interventions periods (intervention group). Only the intervention group had a significant increase in EQ-5D-5L utility scores from baseline to 12 months follow-up (mean change 0.03; 95% CI 0.01, 0.05) with QALYs gained: 0.02 (95% CI -0.08, 0.12). The structured OA model cost approx. €301 p.p. with an additional €50 for the Healthy Eating Program. Total 12 months healthcare cost p.p. was €1281 in the intervention and €3147 in the control group, resulting in an incremental cost of -€1866 (95% CI -3147, -584) p.p. Costs related to surgical procedures had the largest impact on total healthcare costs in both groups. During the 12-months follow-up period, 5% (n=14) in the intervention compared to 12% (n=13) in the control group underwent joint surgery; resulting in a mean surgical procedure cost of €553 p.p. in the intervention as compared to €1624 p.p. in the control group. The ICER was -€93300, indicating that the OA care model resulted in QALYs gained and cost-savings. At a threshold of €27500, it is 99% likely that the OA care model is a cost-effective alternative.Conclusion:The results of the cost-utility analysis show that implementing a structured model for OA care in primary healthcare based on international guidelines is highly likely a cost-effective alternative compared to usual care for people with hip and knee OA. More studies are needed to confirm this finding, but this study results indicate that implementing structured OA care models in primary healthcare may be beneficial for the individual as well as for the society.Disclosure of Interests:None declared


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Muhammad Ashar Naveed ◽  
Muhammad Afnan Ansari ◽  
Inki Kim ◽  
Trevon Badloe ◽  
Joohoon Kim ◽  
...  

AbstractHelicity-multiplexed metasurfaces based on symmetric spin–orbit interactions (SOIs) have practical limits because they cannot provide central-symmetric holographic imaging. Asymmetric SOIs can effectively address such limitations, with several exciting applications in various fields ranging from asymmetric data inscription in communications to dual side displays in smart mobile devices. Low-loss dielectric materials provide an excellent platform for realizing such exotic phenomena efficiently. In this paper, we demonstrate an asymmetric SOI-dependent transmission-type metasurface in the visible domain using hydrogenated amorphous silicon (a-Si:H) nanoresonators. The proposed design approach is equipped with an additional degree of freedom in designing bi-directional helicity-multiplexed metasurfaces by breaking the conventional limit imposed by the symmetric SOI in half employment of metasurfaces for one circular handedness. Two on-axis, distinct wavefronts are produced with high transmission efficiencies, demonstrating the concept of asymmetric wavefront generation in two antiparallel directions. Additionally, the CMOS compatibility of a-Si:H makes it a cost-effective alternative to gallium nitride (GaN) and titanium dioxide (TiO2) for visible light. The cost-effective fabrication and simplicity of the proposed design technique provide an excellent candidate for high-efficiency, multifunctional, and chip-integrated demonstration of various phenomena.


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