scholarly journals DUNE STABILIZATION WITH A SAND/GEL COMPOSITE SYSTEM

1988 ◽  
Vol 1 (21) ◽  
pp. 118
Author(s):  
M.H. Auerbach ◽  
G.W. Borden ◽  
B.L. Edge

The effectiveness of a novel sand/gel composite system for the temporary stabilization of coastal dunes was demonstrated in wavetank and field testing. The composite consists of 97% beach sand and water, with a few percent of a biodegradable aqueous polymeric gel made from nontoxic ingredients. The gel binds the sand into a firm but resilient composite that is natural in appearance and resists erosion from waves and tides. The composite is applied by pneumatic gun to the front face of a dune to a few feet below the berm level for toe protection. This paper describes the initial development and performance of the composite system in wavetank tests at the Oregon State University Wave Research Facility and field trials at Anastasia State Park, St. Augustine, Florida; Chuck's Steak House, Melbourne Beach, Florida; and Ocean Dunes Condominiums, Fort Fisher, North Carolina.


Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 150
Author(s):  
Natalia A. Kulikova ◽  
Alexander B. Volikov ◽  
Olga I. Filippova ◽  
Vladimir A. Kholodov ◽  
Nadezhda V. Yaroslavtseva ◽  
...  

The paper is devoted to the development and performance testing of a soil conditioner based on leonardite humic substances (LHS) modified with 3-aminopropyltriethoxysilane (APTES). The modified HS were obtained by adding APTES to LHS solution at different mass ratios of LHS and APTES, followed by the investigation of siloxane structures using 31Si NMR spectroscopy. The Urbic Technosol was used as a model soil. The size and amount of water-stable soil aggregates were estimated using wet sieving and laser diffraction, respectively. Toxicity was evaluated by monitoring microbial substrate-induced respiration (SIR) and seedling bioassay. Laboratory column experiments demonstrated an increase in water-stability of the 3–5 mm soil aggregates after LHS-APTES application. Field tests showed an increase in the average weighted diameter of micro aggregates (from 59 to 73 μm) and water-stable macroaggregates (from 1.6 to 2.9 mm) due to the LHS-APTES amendment. A substantial increase in SIR from 5 to 9 mg CO2 (kg h)−1 was detected. Better survival of seedlings was observed. The obtained beneficial results indicate that APTES-modified HS can be successfully used as a soil conditioner. The formation of extended siloxane networks was suggested as the main mechanism of the observed improvement in the structure of the amended soils.



Author(s):  
Liye Zhang ◽  
Yong He ◽  
Shoushan Cheng ◽  
Guoliang Wang ◽  
Hongwei Ren ◽  
...  

<p>With the number of bridges increases, the bridge health monitoring (BHM) technique is developing from single bridge monitoring to collaborative supervision of bridge group. Therefore, there are many technical problems need to be solved especially the performance evaluation index for bridge group network. This paper analyses the performance evaluation index of the bridges and bridge group network, establishes the performance evaluation index for bridge group based on rating factor (RF) and technical condition evaluation index. Based on bridge field testing and monitoring data, bridge technical condition evaluation index and performance evaluation method for bridge group are proposed. A case study demonstrates that the research results provide support for bridge group networking monitoring and collaborative supervision.</p>



2018 ◽  
pp. 194-199 ◽  
Author(s):  
Iwona Jaskulska ◽  
Lech Gałęzewski ◽  
Mariusz Piekarczyk ◽  
Dariusz Jaskulski

The emergence of plants is especially important for the winter crops that are grown in the challenging environmental conditions of many countries in Central and Eastern Europe. The emergence and initial growth of winter rapeseed were compared in field trials in a randomized block design with three replicates for plants sown in conventional tillage systems (CT) and strip-till (ST), which had different weather conditions and on soil with a non-uniform texture over a period of two years. Sowing in the CT was carried out using Horsch Pronto 4DC (Germany) at a row distance of 0.29 m. The ST operations were performed using a Pro-Til 4T drill manufactured by Mzuri Limited (Great Britain) - row spacing of 0.36 m. In favourable rainfall and thermal conditions, the density of winter rapeseed plants two weeks after sowing was found to be higher if it was sown after the CT than in the ST system. In the year that had a serious shortage of rainfall during the sowing period, a considerably higher density of plants was achieved using the ST system. The uniformity of plant growth using the ST technology in soil with a varied texture, especially in a year with an unfavourable distribution of rainfall, was proven by less variability in the number of leaves in the rosette, in the dry mass of the leaf rosette and in the root neck thickness of the winter rapeseed than in the CT system. The ST system can create good conditions for the initial development and preparation of rapeseed plants for wintering.



2020 ◽  
Vol 12 (10) ◽  
pp. 1644 ◽  
Author(s):  
Irene Borra-Serrano ◽  
Tom De Swaef ◽  
Paul Quataert ◽  
Jonas Aper ◽  
Aamir Saleem ◽  
...  

Close remote sensing approaches can be used for high throughput on-field phenotyping in the context of plant breeding and biological research. Data on canopy cover (CC) and canopy height (CH) and their temporal changes throughout the growing season can yield information about crop growth and performance. In the present study, sigmoid models were fitted to multi-temporal CC and CH data obtained using RGB imagery captured with a drone for a broad set of soybean genotypes. The Gompertz and Beta functions were used to fit CC and CH data, respectively. Overall, 90.4% fits for CC and 99.4% fits for CH reached an adjusted R2 > 0.70, demonstrating good performance of the models chosen. Using these growth curves, parameters including maximum absolute growth rate, early vigor, maximum height, and senescence were calculated for a collection of soybean genotypes. This information was also used to estimate seed yield and maturity (R8 stage) (adjusted R2 = 0.51 and 0.82). Combinations of parameter values were tested to identify genotypes with interesting traits. An integrative approach of fitting a curve to a multi-temporal dataset resulted in biologically interpretable parameters that were informative for relevant traits.



2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Avinash Kumar Agarwal ◽  
Deepak Agarwal

Abstract This study investigated the use of biodiesel (B100) and baseline mineral diesel in two identical unmodified vehicles to realistically assess different aspects of biodiesel’s compatibility and durability issues with modern common rail direct injection (CRDI) engine-powered vehicles. Two identical vehicles were operated for 30,000 km under identical operating conditions during a field-trial using biodiesel (B100) and mineral diesel. Exhaustive experimental results from this series of tests are divided into four sections, and this is the third paper of this series of four papers, which covers comparative feasibility and wear analyses, underlining the effect of long-term use of biodiesel on wear of cylinder liner and piston rings compared to baseline mineral diesel-fueled vehicle. Surface microstructures at three locations of the cylinder liner were evaluated using scanning electron microscopy (SEM). Wear was found to be relatively lower at all locations of liners from biodiesel-fueled vehicle compared to diesel-fueled vehicle. Surface roughness of cylinder liners measured at different locations showed that it reduced by ∼30–40% at top dead center (TDC), ∼10–20% at mid-stroke, and ∼20–30% at bottom dead center (BDC) for both vehicles, showing higher wear close to TDC compared to mid-stroke and BDC locations. Loss of piston-ring weight was significantly lower for biodiesel-fueled vehicle. Engine tear-down observations and carbon deposits on various engine components were recorded after the conclusion of the field trials. During these field-trials, engine durability-related issues such as fuel-filter plugging, injector coking, piston-ring sticking, carbon deposits in the combustion chamber, and contamination of lubricating oils were found to be relatively lower in biodiesel-fueled vehicle. Overall, no noticeable durability issues were recorded because of the use of biodiesel in CRDI engine-powered vehicle.



Author(s):  
David R. Smith ◽  
Kamal Souccar ◽  
Gabriela Montalvo ◽  
Cesar Arteaga ◽  
José Luis Hernández ◽  
...  




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