1,859 research outputs found

    Integrating Grazing with 2,4-D and Florpyrauxifen to Control Broadleaf Weeds and Maintain Red Clover Productivity in Grass-Legume Pastures

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    In grass-legume pastures, 2,4-D-amine + florpyrauxifen-benzyl controls broadleaf weeds but red clover (Trifolium pratense L.) is eliminated. Grazing within a week prior to herbicide application is likely to reduce leaf surface area and may reduce red clover injury and maintain productivity. Experiments were conducted in 2020 and in 2021 to determine if red clover could be productive when 560 g ae ha-1 2,4-D-amine + 6.3 g ae ha-1 of florpyrauxifen-benzyl with 1% v/v methylated seed oil applied in the spring was grazed before or after herbicide application. Grazing timings occurred 6, 4, or 2 days prior to herbicide application, the day of application, or 6 days after application. Grazing timing did not affect productivity or cover of red clover, white clover, forage grasses, broadleaf weeds, or annual grasses. In contrast, aboveground biomass of broadleaf weeds, red clover, and white clover was \u3e55, 56, and 44% less, respectively, in 2,4-D-amine + florpyrauxifenbenzyl treated pasture than nontreated pasture. Less clover and broadleaf weed biomass in herbicide treated pasture was associated with 16% more perennial grass biomass and no changes in total forage productivity. Results suggest that all grazing timings applied with 2,4-D-amine + florpyrauxifen-benzyl provided effective weed control that persisted more than 1 year with only partial injury to red clover populations. Grazing in concert with herbicide applications improves herbicide selectivity of preferentially grazed species, while improved from conventional standards practicality to producers is still unknown

    Integrating Grazing with 2,4-D and Florpyrauxifen to Control Broadleaf Weeds and Maintain Red Clover Productivity in Grass-Legume Pastures

    Get PDF
    In grass-legume pastures, 2,4-D-amine + florpyrauxifen-benzyl controls broadleaf weeds but red clover (Trifolium pratense L.) is eliminated. Grazing within a week prior to herbicide application is likely to reduce leaf surface area and may reduce red clover injury and maintain productivity. Experiments were conducted in 2020 and in 2021 to determine if red clover could be productive when 560 g ae ha-1 2,4-D-amine + 6.3 g ae ha-1 of florpyrauxifen-benzyl with 1% v/v methylated seed oil applied in the spring was grazed before or after herbicide application. Grazing timings occurred 6, 4, or 2 days prior to herbicide application, the day of application, or 6 days after application. Grazing timing did not affect productivity or cover of red clover, white clover, forage grasses, broadleaf weeds, or annual grasses. In contrast, aboveground biomass of broadleaf weeds, red clover, and white clover was \u3e 55, 56, and 44% less, respectively, in 2,4-D-amine + florpyrauxifenbenzyl treated pasture than nontreated pasture. Less clover and broadleaf weed biomass in herbicide treated pasture was associated with 16% more perennial grass biomass and no changes in total forage productivity. Results suggest that all grazing timings applied with 2,4-D-amine + florpyrauxifen-benzyl provided effective weed control that persisted more than 1 year with only partial injury to red clover populations. Grazing in concert with herbicide applications improves herbicide selectivity of preferentially grazed species, while improved from conventional standards practicality to producers is still unknown

    Design considerations for large space electric power systems

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    As power levels of spacecraft rise to the 50 to 100 kW range, it becomes apparent that low voltage (28 V) dc power distribution and management systems will not operate efficiently at these higher power levels. The concept of transforming a solar array voltage at 150 V dc into a 1000 V ac distribution system operating at 20 kHz is examined. The transformation is accomplished with series-resonant inverter by using a rotary transformer to isolate the solar array from the spacecraft. The power can then be distributed in any desired method such as three phase delta to delta. The distribution voltage can be easily transformed to any desired load voltage and operating frequency. The reasons for the voltage limitations on the solar array due to plasma interactions and the many advantages of a high voltage, high frequency at distribution system are discussed

    Polyethylene Terephthalate (PET) Waste as Partial Aggregate and Reinforcement in Reinforced Concrete: A Review

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    Plastic disposal is now a significant problem for the sustainability of the environment. And, viewing the engineering properties of plastics (e.g., lightweight, flexible, strong, moisture-resistant, and cheap) opens the possibility of using them as a structural material. Over the decade, many researchers have studied using plastics as a replacement for natural aggregates in concrete or as an additive. Besides, past experimental results have shown that adding plastic waste in concrete will alter the concrete's mechanical and durability properties. However, such concrete can still fulfill engineering properties and be used in other structures with low strength requirements. This research intends to try other possibilities of using plastic waste as partial aggregate and reinforcement in reinforced concrete. Therefore, it is proposed that researchers look into the effects of plastic particles in concrete on the environment and their durability over time due to its deterioration. It recommends surface treatment of plastics waste using appropriate chemicals

    Polyethylene Terephthalate (PET) Waste as Partial Aggregate and Reinforcement in Reinforced Concrete: A Review

    Get PDF
    Plastic disposal is now a significant problem for the sustainability of the environment. And, viewing the engineering properties of plastics (e.g., lightweight, flexible, strong, moisture-resistant, and cheap) opens the possibility of using them as a structural material. Over the decade, many researchers have studied using plastics as a replacement for natural aggregates in concrete or as an additive. Besides, past experimental results have shown that adding plastic waste in concrete will alter the concrete's mechanical and durability properties. However, such concrete can still fulfill engineering properties and be used in other structures with low strength requirements. This research intends to try other possibilities of using plastic waste as partial aggregate and reinforcement in reinforced concrete. Therefore, it is proposed that researchers look into the effects of plastic particles in concrete on the environment and their durability over time due to its deterioration. It recommends surface treatment of plastics waste using appropriate chemicals

    Algebraic Properties of Qualitative Spatio-Temporal Calculi

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    Qualitative spatial and temporal reasoning is based on so-called qualitative calculi. Algebraic properties of these calculi have several implications on reasoning algorithms. But what exactly is a qualitative calculus? And to which extent do the qualitative calculi proposed meet these demands? The literature provides various answers to the first question but only few facts about the second. In this paper we identify the minimal requirements to binary spatio-temporal calculi and we discuss the relevance of the according axioms for representation and reasoning. We also analyze existing qualitative calculi and provide a classification involving different notions of a relation algebra.Comment: COSIT 2013 paper including supplementary materia

    Sign segmentation with changepoint-modulated pseudo-labelling

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    The objective of this work is to find temporal boundaries between signs in continuous sign language. Motivated by the paucity of annotation available for this task, we propose a simple yet effective algorithm to improve segmentation performance on unlabelled signing footage from a domain of interest. We make the following contributions: (1) We motivate and introduce the task of source-free domain adaptation for sign language segmentation, in which labelled source data is available for an initial training phase, but is not available during adaptation. (2) We propose the Changepoint-Modulated Pseudo-Labelling (CMPL) algorithm to leverage cues from abrupt changes in motion-sensitive feature space to improve pseudo-labelling quality for adaptation. (3) We showcase the effectiveness of our approach for category-agnostic sign segmentation, transferring from the BSLCORPUS to the BSL-1K and RWTH-PHOENIX-Weather 2014 datasets, where we outperform the prior state of the art

    Preliminary Investigation of Possible Biochar Use as Carbon Source in Polyacrylonitrile Electrospun Fiber Production

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    Electrospinning with consequent thermal treatment consists in a carbon fiber production method that spins a polymer solution to create fibers with diameters around a few hundred nanome-ters. The thermal treatments are used for the cyclization and then carbonization of the material at 1700◦C for one hour. The unique structure of micro-and nano-carbon fibers makes them a promis-ing material for various applications ranging from future battery designs to filtration. This work investigated the possibility of using milled gasification biochar, derived from a 20 kW fixed-bed gasifier fueled with vine pruning pellets, as an addictive in the preparation of electrospinning solu-tions. This study outlined that solvent cleaning and the consequent wet-milling and 32 µm sifting are fundamental passages for biochar preparation. Four different polyacrylonitrile-biochar shares were tested ranging from pure polymer to 50–50% solutions. The resulting fibers were analyzed via scanning electron microscopy, and energy-dispersive X-ray and infrared spectroscopy. Results from the morphological analysis showed that biochar grains dispersed themselves well among the fiber mat in all the proposed shares. All the tested solutions, once carbonized, exceeded 97%wt. of carbon content. At higher carbonization temperatures, the inorganic compounds naturally showing in biochar such as potassium and calcium disappeared, resulting in an almost carbon-pure fiber matrix with biochar grains in between

    Iron(III) Complexes on a Dendrimeric Basis and Various Amine Core Investigated by Mössbauer Spectroscopy

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    Dendrimers of various generations were synthesized by the divergent method. Starting from various amine cores (G(0a), G(0b), G(0c)) the generations were built by reaction of the amine with acrylnitrile followed by hydrogenation with DIBAL-H. Treatment with salicylaldehyde creates a fivefold coordination sphere for iron in the molecular periphery. The resulting multinuclear coordination compounds are investigated by Mossbauer spectroscopy
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