scholarly journals Aircraft Arrestor System Panel Joint Improvement

2021 ◽  
Author(s):  
Jesse D. Doyle ◽  
Nolan R. Hoffman ◽  
M. Kelvin Taylor
Keyword(s):  
Current Practice ◽  
Thermal Response ◽  
Field Performance ◽  
Field Evaluation ◽  
Field Studies ◽  
Construction Techniques ◽  
Military Applications ◽  
Cable Damage ◽  
Ultra High Molecular Weight ◽  
Preparation Techniques

Aircraft Arresting Systems (AAS) for military applications utilize sacrificial panels made of Ultra-High Molecular Weight polyethylene (UHMWPE) that are embedded into the pavement beneath the AAS cable to protect the pavement from cable damage. Problems have been observed with the materials and practices used to seal the UHMWPE panel joints from water and debris. Data obtained from laboratory and field studies were used make improvements to current practice for sealing UHMWPE panel joints. The study evaluated four joint-sealant materials, eight alternative surface treatment and preparation techniques to promote adhesion to UHMWPE, and seven joint-edge geometries. Bond-strength testing of joint-sealant specimens was conducted in the laboratory, followed by field evaluation of construction techniques. Field performance of the joint systems was monitored for 24 months after installation. Additionally, a thermal response model was developed to refine the joint design dimensions. Results confirmed that the best material to use was self-leveling silicone joint sealant. It was recommended that a dovetail groove be cut into the edge of UHMW panels to provide positive mechanical interlock and to reduce adhesive failures of the sealant. It was also recommended that the panel-to-panel joint-sealant reservoir be widened to prevent sealant compression damage.

Field evaluation of tissue-cultured bananas in south-eastern Queensland

1990 ◽  
Vol 30 (4) ◽  
pp. 569 ◽  
Author(s):  
RA Drew ◽  
MK Smith
Keyword(s):  
Callus Culture ◽  
Field Performance ◽  
Field Evaluation ◽  
Ratoon Crop ◽  
Musa Sp ◽  
Planting Material ◽  
Lateral Buds ◽  
Conventional Material ◽  
Banana Cultivar ◽  
Plant Crop

Field performance is described for tissue cultured plants and conventional propagules of planting material of banana cultivar 'New Guinea Cavendish' (Musa sp., AAA group, Cavendish subgroup). Tissuecultured plants were produced by either regeneration of plants from callus culture or by micropropagation of plants following the release of dormant buds at the leaf axils of explants. The conventional material consisted of suckers and 'bits' (lateral buds and associated corm material). Tissue-cultured plants established more quickly, were taller, and had a shorter time to bunch emergence and harvest of plant crop than conventional planting material. They had significantly (P<0.05) higher yields in terms of bunch weight, which was a function of greater numbers of fingers and hands. These advantages did not extend to the ratoon crop. Sucker production on tissue-cultured plants was significantly (P<0.01) higher up to 8 months after planting, equal to conventional material from 8 months to harvest, and then significantly lower. Twenty-two per cent of the plants derived from callus were off-types compared with 3% in the line produced by axillary bud proliferation. No off-types were observed in conventional planting material.

Use of Seedling Growth Parameters to Classify Soybean (Glycine max) Cultivar Sensitivity to Sulfentrazone

1999 ◽  
Vol 13 (3) ◽  
pp. 530-535 ◽  
Author(s):  
Zhaohu Li ◽  
Robert H. Walker ◽  
Glenn Wehtje ◽  
H. Gary Hancock
Keyword(s):  
Glycine Max ◽  
Seedling Growth ◽  
Root Length ◽  
Reduction Method ◽  
Growth Parameters ◽  
Field Evaluation ◽  
Relative Sensitivity ◽  
Field Studies ◽  
Laboratory Studies ◽  
Length Reduction

Hypocotyl and root length reduction of soybean (Glycine max) seedlings when seeds were exposed to sulfentrazone during germination were used as indices to classify cultivar response to soil-applied sulfentrazone. Seeds of ‘Stonewall’ (sulfentrazone tolerant) and ‘Asgrow 6785’ (sulfentrazone sensitive) were imbibed and allowed to germinate in 0, 1, 5, 10, and 50 ppm aqueous sulfentrazone solutions for 4 d. Hypocotyl and root lengths were reduced in both cultivars, but the reductions were greater for Asgrow 6785 than for Stonewall. Subsequently, the relative sensitivity of 28 cultivars to sulfentrazone was independently determined by two variations of the hypocotyl reduction method (both conducted in the laboratory) and by traditional full-season field evaluation. Results from laboratory and field studies were in agreement for cultivars distinctly sensitive or tolerant to sulfentrazone. However, cultivars with intermediate tolerance in laboratory studies produced variable responses in the field.

Field evaluation of host kairomones and pheromones for capture of Conophthorus coniperda (Coleoptera: Scolytidae)

2006 ◽  
Vol 138 (5) ◽  
pp. 723-732 ◽  
Author(s):  
A.M. Brauner ◽  
P. de Groot
Keyword(s):  
Field Evaluation ◽  
Field Studies ◽  
Trap Catch ◽  
White Pine ◽  
Release Rates ◽  
Female Response ◽  
Pine Cone ◽  
Equivalent Efficacy ◽  
Trap Catches ◽  
Conophthorus Coniperda

AbstractField studies were conducted to determine the attractiveness of monoterpenes and pheromones to the white pine cone beetle, Conophthorus coniperda (Schwarz), the most destructive cone and seed pest of eastern white pine, Pinus strobus L. (Pinaceae). Limonene was identified as a new attractant that acts synergistically when added to the female-produced sex pheromone, pityol. Trap catches were higher with increasing release rates of S-(–)-limonene. The enantiomers of limonene showed equivalent efficacy on mean trap catch. (–)-β-Pinene was not attractive and may be repellent to both sexes, and (–)-α-pinene was shown to have no effect on female response when added to pityol or pityol + S-(–)-limonene. The pheromones trans-verbenol, trans-pinocarveol, and myrtenol were not attractive to C. coniperda.

Field evaluation of tissue-cultured papaw clones in Queensland

1993 ◽  
Vol 33 (4) ◽  
pp. 475 ◽  
Author(s):  
RA Drew ◽  
JN Vogler
Keyword(s):  
Field Performance ◽  
Field Evaluation ◽  
Root Systems ◽  
Planting Date ◽  
Adult Tissue ◽  
Node Number ◽  
Juvenile Phase ◽  
Commercial Practice ◽  
Lower Height ◽  
Reduced Time

Field performance of tissue-cultured clones of papaws established either from adult tissue of a high-yielding female plant or from juvenile tissue of seedlings (2 females and 2 hermaphrodites) was compared with seedling controls. All tissue-cultured plants had strong root systems and established more quickly than seedlings. Plants from adult tissue (TCA) had a reduced juvenile phase, as evidenced by increased circumference, lower height of first flower, reduced time to harvest, and higher fruit numbers per metre of stem. Planting date affected node number of first flower for TCA plants but not seedlings. TCA plants had higher yields than seedlings when planted in spring, and this could lead to improved commercial practice. Differences between clones established from juvenile tissue and their respective seedling controls varied and were not consistent with a reduced juvenile phase. Four dwarf off-type plants (<1% of population) originated from a single bud explant.

Field Evaluation of Late Merge Traffic Control in Work Zones

2005 ◽  
Vol 1911 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Andrew G. Beacher ◽  
Michael D. Fontaine ◽  
Nicholas J. Garber
Keyword(s):  
Field Test ◽  
Traffic Control ◽  
Positive Response ◽  
Field Evaluation ◽  
Field Studies ◽  
Work Zone ◽  
Work Zones ◽  
Short Term ◽  
Term Field ◽  
Lane Closures

The traffic control strategy of the late merge in work zones was devised to improve flow and safety at work zone lane closures. Although some states have put the strategy into practice, only a handful of short-term field studies have formally evaluated its effectiveness. Additional field studies were necessary to assess the efficacy of the strategy and its proper deployment. This paper documents the results of a field test of the late merge traffic control conducted over several months. The late merge strategy was evaluated by comparing its effectiveness with that of traditional plans for work zone lane closures. The field test was conducted on a primary route in Tappahannock, Virginia, at a two-to-one lane closure. Results showed that throughput increased, but the increase was not statistically significant. Likewise, time in queue decreased, but the decrease was not statistically significant. These results were much less dramatic than those of other studies. Possible reasons for this disparity include different driver populations, road types, vehicle mixes, and site-specific characteristics. Despite limited improvements in throughput and time in queue, more drivers were in the closed lane, a positive response to the late merge signs.

Field Evaluation and Cost Effectiveness of Crack Sealing in Flexible and Composite Pavements

2018 ◽  
Vol 2672 (12) ◽  
pp. 51-61 ◽  
Author(s):  
Momen Mousa ◽  
Mostafa A. Elseifi ◽  
Mohammad Bashar ◽  
Zhongjie Zhang ◽  
Kevin Gaspard
Keyword(s):  
Cost Effectiveness ◽  
Cost Benefit Analysis ◽  
Field Performance ◽  
Cost Benefit ◽  
Cost Effective ◽  
Field Evaluation ◽  
Asphalt Emulsion ◽  
Transverse Cracks ◽  
Crack Sealing ◽  
Composite Pavements

One of the most common methods used to treat longitudinal and transverse cracks is crack sealing (CS), which is categorized as a preventive maintenance method. Field performance and cost-effectiveness of this treatment widely vary depending on pavement conditions and installation of the material. The objective of this study was to evaluate the field performance and cost-effectiveness of CS in flexible and composite pavements in hot and wet climates such as Louisiana, and to develop a model that would quantify the expected benefits of CS given project conditions. To achieve this objective, 28 control sections that were crack-sealed between 2003 and 2010 were monitored for at least four years. These sections included flexible and composite pavements, sealed and unsealed segments, and varying traffic levels. The performance of these sections was evaluated for the random cracking index (RCI) and roughness index (RI). Based on the results of this analysis, it was concluded that CS only has a significant impact on random cracking. When compared with untreated segments, CS extended pavement service life (PSL) by two years. When compared with the original pavement, CS extended PSL by 5.6 and 3.2 years for flexible and composite pavements, respectively, if applied at the correct time. The cost-benefit analysis indicated that CS is cost-effective whether asphalt emulsion or rubberized asphalt sealant is used. A non-linear regression model was developed to predict the extension in PSL because of CS without the need for performance data based on the average daily traffic (ADT), pavement type, and prior pavement conditions.

Second Generation Wire Development at AMSC

2013 ◽  
Vol 23 (3) ◽  
pp. 6601205-6601205 ◽  
Author(s):  
Martin Rupich ◽  
Xiaoping Li ◽  
Srivatsan Sathyamurthy ◽  
Cornelis Thieme ◽  
Kenneth DeMoranville ◽  
...  
Keyword(s):  
Critical Current ◽  
Large Scale ◽  
Second Generation ◽  
Field Performance ◽  
Critical Currents ◽  
Production Scale ◽  
Wide Range ◽  
Military Applications ◽  
Metal Organic ◽  
Deposition Processes

AMSC has established a Second Generation (2G) High-Temperature Superconductor (HTS) wire manufacturing technology based on the Rolling Assisted Biaxially Textured Substrate and Metal Organic Deposition processes. AMSC's 2G wire (Amperium) has been used by a wide range of customers for development and testing of initial commercial HTS-based applications. Although the Amperium wire properties and quantities satisfy the requirements for these initial projects, improvements in critical current, field performance, and cost are beneficial for large-scale commercial and military applications. As Amperium wire manufacturing continues to ramp up, AMSC's R&D program has focused on increasing critical current, and the development of nonmagnetic substrates. The R&D process developed for a single-coat, 1.2 &#x03BC;m YBCO film has been transferred to production-scale equipment, resulting in the first Amperium wires with critical currents reaching 500 A/cm-w (77 K, self-field) in production length. A nonmagnetic substrate, which minimizes ferromagnetic substrate losses in ac cable applications, has been produced in R&D lengths and demonstrated in an Amperium cable wire.

Field Evaluation of Ability of Photocatalytic Concrete Pavements to Remove Nitrogen Oxides

2012 ◽  
Vol 2290 (1) ◽  
pp. 154-160 ◽  
Author(s):  
Heather Dylla ◽  
Marwa M. Hassan ◽  
David Osborn
Keyword(s):  
Nitrogen Oxides ◽  
Real World ◽  
Field Evaluation ◽  
Field Studies ◽  
The United States ◽  
Operating Variables ◽  
Show Evidence ◽  
Solar Intensity ◽  
The Many ◽  
Photocatalytic Concrete

Numerous laboratory studies have demonstrated the ability of nano and ultrafine titanium dioxide (TiO2) photocatalytic pavements to trap and degrade nitrogen oxides in the air when irradiated with ultraviolet light. However, to understand better how photocatalytic pavements will perform under real-world conditions, field studies are necessary. Quantification of the reduction of nitrogen oxides (NOx) in field studies is difficult and challenging because of the many environmental and operating variables. The objective of this paper is to identify evidence of photocatalytic NOx reduction and to determine the environmental and operating factors that affect efficiencies under real-world conditions. A quarter-mile concrete roadway was sprayed with a photocatalytic coating in Baton Rouge, Louisiana. This section was the first field installation of TiO2 photocatalytic pavement in the United States. NOx concentrations were monitored for both the coated and uncoated sections simultaneously for 3 weeks during the spring season to measure photocatalytic degradation directly. Further, nitrates were collected from the coated and uncoated areas for evidence of photocatalytic NOx reduction. Results from both approaches show evidence of photocatalytic NOx reduction. Environmental factors with significant impact on photocatalytic efficiency include relative humidity, solar intensity, and wind speed and direction.

Field evaluation of ecological differentiation of dwarf mistletoe on shore pine and western hemlock

1976 ◽  
Vol 6 (2) ◽  
pp. 225-228 ◽  
Author(s):  
R. B. Smith ◽  
E. F. Wass
Keyword(s):  
British Columbia ◽  
Field Evaluation ◽  
Field Studies ◽  
Western Hemlock ◽  
Lake Area ◽  
Dwarf Mistletoe ◽  
Varied Composition ◽  
Coastal British Columbia ◽  
Ecological Races ◽  
Shore Pine

Hemloclc dwarf mistletoe (Arcenthobiiuntsugense (Rosend.) G. N. Jones) principally infects western hemlock (Tsugaheteropliylla (Raf.) Sarg.), but it is also damaging to shore pine (Pinuscontorta Dougl. ex Loud.) growing in coastal British Columbia. Stands of varied composition were studied in the Home Lake area of Vancouver Island to compare the levels of infection in shore pine and western hemlock. Infection of shore pine occurred whether or not infected hemlock trees were present in the stand. Observations and measurements from these field studies support indications from earlier artificial inoculation trials that two ecological races of A. tsugense exist.

Operating Experience of the First Solar® Taurus 70S Mechanical Drive Installation

1997 ◽  
Author(s):  
A. James Hoshizaki
Keyword(s):  
Gas Turbine ◽  
Performance Test ◽  
Operating Experience ◽  
Field Performance ◽  
Field Evaluation ◽  
Pipeline System ◽  
Test Results ◽  
Compressor Station ◽  
Test Program ◽  
Natural Gas Pipeline

In October 1995, NOVA Gas Transmission Ltd. (NGTL) commissioned the first mechanical drive application of Solar Turbines’ Taurus™ 70S gas turbine. The unit was installed as a part of a turbine/compressor package at a compressor station on NGTL’s natural gas pipeline system. As this first installation was a part of a development test program by Solar Turbines, field evaluation was conducted subsequent to the original commissioning and related testing. This paper presents NGTL’s experiences in commissioning, startup and operation. Field performance test results for the gas turbine are presented and focus on output power, thermal efficiency and exhaust emissions. Some of the findings and observations from the field evaluation tests performed by Solar are also discussed. In addition, a description of the facility in which the turbine/compressor package is installed is provided.

Sign in / Sign up

Export Citation Format

Share Document