The Experts below are selected from a list of 479853 Experts worldwide ranked by ideXlab platform
J A Gomez - One of the best experts on this subject based on the ideXlab platform.
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a Field Evaluation of the impact of temporary cover crops on soil properties and vegetation communities in southern spain vineyards
Agriculture Ecosystems & Environment, 2019Co-Authors: Gema Guzman, Jose Manuel Cabezas, Rafael Sanchezcuesta, Angel Lora, Thomas Bauer, Peter Strauss, Silvia Winter, Johann G Zaller, J A GomezAbstract:Abstract Transition from bare soil to temporary cover crop-based soil management has been promoted for at least two decades in vineyards in southern Spain. However, there is limited Field Evaluation of its impact at commercial vineyard level. Our study evaluates the impact of these two soil managements in sixteen commercial vineyards in Southern Spain. Selected soil physical, chemical and biological properties were measured in a representative inter-row of each vineyard during 2015-2016. Overall, the temporary cover crop vineyard presented a significant improvement in soil organic carbon content and aggregate stability in comparison to the bare soil vineyards, 73 and 29% respectively, as well as presenting more diverse plant communities. Nevertheless, there was a large variability among vineyards that preclude the identification of other impacts and differences among the different kind of temporary cover crops followed by the winegrowers. A refined analysis concentrated in the eleven vineyards on more calcareous soils distinguishing among bare soil, spontaneous cover crop of low biomass production, spontaneous cover crop of high biomass production and barley cover crop of high biomass production was performed. It resulted in a larger improvement in soil properties in the vineyards having a spontaneous cover crop of high biomass production followed by the ones having a cover crop with barley. It also showed how the spontaneous cover crop of low biomass production presented a moderate or negligible improvement in soil properties as compared to the bare soil vineyards. In general terms, the best strategy seemed to be the vineyards with spontaneous cover crops that were able to achieve a high biomass production, above 0.91 t ha−1 per year, which also presented a high plant diversity. Our results indicate the need for a proper Evaluation of the impact of cover crop-based management based on vineyard assessment of soil properties and their relation with driving variables, as in our case biomass production and composition of the cover crops.
And Development, U.s. Humanitarian Demining Research - One of the best experts on this subject based on the ideXlab platform.
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HD R&D Field Evaluation: Rebel Crusher
JMU Scholarly Commons, 2020Co-Authors: And Development, U.s. Humanitarian Demining ResearchAbstract:The Rebel Crusher is a commercial mobile soil sifter and rock crushing plant modified for demining operations. It is designed to operate in areas where a significant fraction of the soil is composed of mine-sized objects (rocks) which make sifting difficult, or where dense metallic clutter makes mines undetectable. Modifications to the system include hardening the crushing chamber to withstand anti-personnel mine blasts, and increasing the capacity of the sifting mechanism. The Rebel Crusher is capable of processing 75-125 tons of soil per hour. Distribution Statement A: Approved for public release
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HD R&D Field Evaluation: REX
JMU Scholarly Commons, 2020Co-Authors: And Development, U.s. Humanitarian Demining ResearchAbstract:Remote controlled excavators are sometimes required when it is too dangerous for manual operation. The Rex is a versatile, light weight (8 ton class) armored excavator designed to clear vegetation, obstacles, and mechanically remove and neutralize anti-personnel (AP) landmines and unexploded ordnance (UXO). The HD R&D Program developed and integrated two important modifications to the commercial Terex TC75 excavator to create the Rex. These are the addition of remote control capability, and armor protection for the operator when the system is manually operated. Small platform based system advantages are lightweight, versatile and fuel efficient. Distribution Statement A: Approved for public release
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HD R&D Field Evaluation: Multi-Tool Attachments
JMU Scholarly Commons, 2020Co-Authors: And Development, U.s. Humanitarian Demining ResearchAbstract:The Humanitarian Demining Research and Development (HD R&D) Program has developed a wide variety of excavator and loader based tools for mechanical mine clearance. These attachments give deminers the capability to perform area preparation, technical survey and mine clearance from a safe area. Tools that have proven useful include vegetation cutters, grapples, tillers, and buckets for sifting, grinding, and crushing. The HD R&D Program has modified several small, medium and large class excavators with armor protection and the interfaces needed to use these tools in various demining environments. Operational Field Evaluations (OFE) can be performed with HD R&D Program developed excavators or loaders, or with just the tools mounted to the demining organization`s own host equipment. Distribution Statement A: Approved for public release
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HD R&D Field Evaluation: Multi-Tool Excavator
JMU Scholarly Commons, 2020Co-Authors: And Development, U.s. Humanitarian Demining ResearchAbstract:Providing reach-in capability for safe operations with manned equipment, Multi-Tooled Excavators offer highly flexible platforms from which operators can conduct ground preparation and specialized mine clearing processes. The combination of tools for sifting, shredding, and combined function excavation and sifting, is tailored to suit local conditions and demining requirements. The attachments can be fitted to the demining organization`s own armored excavator. Distribution Statement A: Approved for public release
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HD R&D Field Evaluation: Mine Clearing Loader
JMU Scholarly Commons, 2020Co-Authors: And Development, U.s. Humanitarian Demining ResearchAbstract:The Mine Clearing Loader project is evaluating commercial construction loaders with sifting and screening attachments for mine clearance and technical survey. The protected cab shields the operator from risk of unintended mine blast during clearance operations. The system also performs significant excavation and tilling tasks for mine recovery and area preparation, as well as service tasks related to transporting mine contaminated soils and loading of mine contaminated soils into secondary processing equipment. The Humanitarian Demining R&D Program is evaluating this technology for its more efficient application over excavator based reach-in tools. Distribution Statement A: Approved for public release
Gema Guzman - One of the best experts on this subject based on the ideXlab platform.
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a Field Evaluation of the impact of temporary cover crops on soil properties and vegetation communities in southern spain vineyards
Agriculture Ecosystems & Environment, 2019Co-Authors: Gema Guzman, Jose Manuel Cabezas, Rafael Sanchezcuesta, Angel Lora, Thomas Bauer, Peter Strauss, Silvia Winter, Johann G Zaller, J A GomezAbstract:Abstract Transition from bare soil to temporary cover crop-based soil management has been promoted for at least two decades in vineyards in southern Spain. However, there is limited Field Evaluation of its impact at commercial vineyard level. Our study evaluates the impact of these two soil managements in sixteen commercial vineyards in Southern Spain. Selected soil physical, chemical and biological properties were measured in a representative inter-row of each vineyard during 2015-2016. Overall, the temporary cover crop vineyard presented a significant improvement in soil organic carbon content and aggregate stability in comparison to the bare soil vineyards, 73 and 29% respectively, as well as presenting more diverse plant communities. Nevertheless, there was a large variability among vineyards that preclude the identification of other impacts and differences among the different kind of temporary cover crops followed by the winegrowers. A refined analysis concentrated in the eleven vineyards on more calcareous soils distinguishing among bare soil, spontaneous cover crop of low biomass production, spontaneous cover crop of high biomass production and barley cover crop of high biomass production was performed. It resulted in a larger improvement in soil properties in the vineyards having a spontaneous cover crop of high biomass production followed by the ones having a cover crop with barley. It also showed how the spontaneous cover crop of low biomass production presented a moderate or negligible improvement in soil properties as compared to the bare soil vineyards. In general terms, the best strategy seemed to be the vineyards with spontaneous cover crops that were able to achieve a high biomass production, above 0.91 t ha−1 per year, which also presented a high plant diversity. Our results indicate the need for a proper Evaluation of the impact of cover crop-based management based on vineyard assessment of soil properties and their relation with driving variables, as in our case biomass production and composition of the cover crops.
Louay N Mohammad - One of the best experts on this subject based on the ideXlab platform.
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use of sweep test for emulsion and hot asphalt chip seals laboratory and Field Evaluation
Journal of Testing and Evaluation, 2013Co-Authors: Nazimuddi M Wasiuddi, Amanda Marshall, Nibe E Saltibus, Aziz Sabe, Christophe Abadie, Louay N MohammadAbstract:Currently, the scope of the standard test method for sweep test of bituminous emulsion surface treatment samples (ASTM D7000) is limited to emulsion-based chip seals only. To this end, the objective of this study is to evaluate the sensitivity of the sweep test for both emulsions and hot asphalts, with respect to aggregate mineralogical types, aggregate precoating, aggregate moisture content, asphaltic materials type, and application rates of asphaltic materials. For the Field Evaluation, fifteen chip seal test sections were prepared with three asphaltic materials and five aggregates in a 9-acre parking lot. Two years after construction, each of the 15 sections were visually inspected for aggregate loss and bleeding. Each section was given a distress rating. The % aggregate loss from the sweep test was then compared with the Field distress rating. Both laboratory and Field tests indicate that overall, expanded shale lightweight aggregate is better than any crushed stone, whereas clay lightweight performed the worst among the six aggregates tested in this study. Precoated expanded shale lightweight aggregates performed better than uncoated shale lightweight aggregates, with respect to % aggregate loss. Between the two hot asphalts, PAC-15 performed better than AC20-5TR. In the case of hot asphalt, the % aggregate loss increases as moisture content increases in oven dry, air dry, and saturated surface dry aggregates. However, for emulsion, air dry aggregates performed the best. For both emulsion and hot asphalt, an increase in asphaltic materials application rate reduces the % aggregate loss significantly. Distress rankings in all 15 sections, except for one PAC-15 section, matched sweep test rankings. Overall, the results indicate that the sweep test using both emulsion and hot asphalt can be an effective tool for Evaluation of performance of chip seals.
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use of sweep test for emulsion and hot asphalt chip seals laboratory and Field Evaluation
Transportation Research Board 91st Annual MeetingTransportation Research Board, 2012Co-Authors: Nazimuddi M Wasiuddi, Amanda Marshall, Nibe E Saltibus, Aziz Sabe, Christophe Abadie, Louay N MohammadAbstract:In 2011 ‘Manual for Emulsion-Based Chip Seals for Pavement Preservation’, sweep test is recommended as one of the laboratory test methods for chip seal design and construction. Currently, sweep test is considered to be a promising test for emulsion-based chip seals. To this end, the objective of this study is to evaluate the sensitivity of sweep test for both emulsions and hot asphalts with respect to aggregate mineralogical types, aggregate precoating, aggregate moisture content, asphaltic materials type and application rates of asphaltic materials. For Field Evaluation, fifteen chip seal test sections were prepared with three asphaltic materials and five aggregates in a 9-acre parking lot. After two years of construction, each of the fifteen sections was visually inspected primarily for aggregate loss and bleeding and was given a distress rating. The percent aggregate loss from sweep test was compared with the Field distress rating. The results indicate that shale lightweight is better than any crushed stone while clay lightweight performed worst among the six aggregates tested using sweep test. Precoated aggregates performed better with hot asphalt than emulsion. Between the two hot asphalts, PAC-15 performed better than AC20-5TR. In case of hot asphalt, percent aggregate loss increases as moisture content increases in oven dry, air dry and saturated surface dry aggregate. However, for emulsion, air dry aggregates performed the best. For both emulsion and hot asphalt, an increase in asphaltic materials application rate reduces the percent aggregate loss significantly. In Field Evaluation, distress survey ranking matched with sweep test results except for one CRS-2P section and one PAC-15 section. Finally, three replicates were used in this study and overall, the results indicate that sweep test using both emulsions and hot asphalts can be an effective tool for Evaluation of performance of chip seals with respect to aggregate mineralogy, precoating, aggregate moisture content, types of asphaltic materials, application rates of asphaltic materials, and later Field distresses.
Yuxian Xia - One of the best experts on this subject based on the ideXlab platform.
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long term Field Evaluation and large scale application of a metarhizium anisopliae strain for controlling major rice pests
Journal of Pest Science, 2021Co-Authors: Guoxiong Peng, Jiaqin Xie, Rong Guo, Nemat O Keyhani, Deyu Zeng, Puyun Yang, Yuxian XiaAbstract:There is increasing concern about the toxic effects of chemical pesticides on human health and the environment. Many alternatives, however, are viewed as impracticable or inefficient for agricultural needs. Here, a sustainable, environmentally friendly strategy was designed for the control of major rice insect pests (i.e. Nilaparvata lugens, Cnaphalocrocis medinalis and Chilo suppressalis) with minimal impact on natural enemies via selection of a specific entomopathogenic fungal strain for use as a biological control agent. In large-scale multiyear Field applications, Metarhizium anisopliae CQMa421 was shown to act as effectively as chemical pesticides for pest control. Rice pest control applications in all major rice-producing provinces in China covering > 6000 hectares, performed over a period of 8 years (2011–2018), showed equal rice harvest yields between the use of the fungal pathogen versus chemical pesticides. More importantly, the use of the specific fungal pathogen isolated by this strategy resulted in an increase in beneficial insects and other animals. These long-term Field Evaluation data and large-scale application results demonstrated the feasibility of shifting from chemical dependency to more nuanced approaches for pest control for maintaining agricultural productivity while protecting natural enemies. With this strategy, new specific fungal strains can also be isolated to control the main pests of other crops.