Airborne off-target losses and deposition characteristics from a self-propelled, high speed and high clearance ground sprayer

1997 ◽  
Vol 77 (3) ◽  
pp. 493-500 ◽  
Author(s):  
Raj Grover ◽  
John Maybank ◽  
Brian C. Caldwell ◽  
Thomas M. Wolf
Keyword(s):  
High Speed ◽  
Petri Dish ◽  
Field Trials ◽  
Droplet Volume ◽  
Wind Speeds ◽  
Extended Range ◽  
Different Types ◽  
Design Characteristics ◽  
Low Drift ◽  
High Clearance

In order to quantify the drift and deposition characteristics of a self-propelled, high-speed, and high-clearance sprayer, a series of 15 field trials was carried out applying a herbicide:dye mix along a test swath. Three different types of nozzle tips were used, an XR11002 (Extended Range XR Teejet®), and two "low-drift" tips, a DG11002 (Drift Guard Teejet®) and a TT11002 (Turbo Teejet®). On-swath and off-swath deposits were sampled using petri-dish collectors, while the airborne cloud was sampled 5 m downwind of the swath using Rotorod® samplers. In wind speeds of 10 to 31 km h−1, airborne droplet drift was reduced by a factor of two with both "low drift" designs. The differences in the behaviour of the two low-drift tips from the standard tips were attributed to reductions in the total volume emitted as drift-prone droplets by the low-drift tips, resulting from their inherent design characteristics. On-swath deposit uniformity was best with the DG11002 tips and worst with the TT11002 tips, with the XR11002 tips being intermediate. Off-swath-deposits increased with wind speed. Off-swath deposits between 5 and 10 m were proportional to the total airborne mass at 5 m. Key words: Pesticide, Spra-Coupe, droplet drift, flat-fan tips, deposition variability, droplet size, droplet volume

Circular Cylinder Wake Configurations: A Flow Visualization Survey

1991 ◽  
Vol 44 (6) ◽  
pp. 255-305 ◽  
Author(s):  
Madeleine Coutanceau ◽  
Jean-Rene´ Defaye
Keyword(s):  
Circular Cylinder ◽  
High Speed ◽  
Three Dimensional ◽  
Cylinder Wake ◽  
Periodic Motions ◽  
Extended Range ◽  
Different Types ◽  
Speed Regime ◽  
Lock In ◽  
Evolution With Time

The survey starts with the presentation of the general principles underlying the different types of techniques which are most often used in wake visualization with their advantages, but also their respective limits. Then information deduced from flow pictures collected from the literature from the beginning of the century up to the present has been used to characterize the wake structure of a circular cylinder (at rest or submitted to various motions) and its evolution with the Reynolds number for an extended range (0 < Re < 107). Incompressible flow has been more particularly considered, both in the quasi-established phase (ten regimes are differentiated and extensively described) and in the transient phase (specific features are pointed out). Special attention has been paid to three-dimensional and memory effects by a combined presentation of crosswise and spanwise observations of the wake phenomena as well as their evolution with time. The influence of compressibility in the high-speed regime and of superimposed periodic motions, either on the cylinder or on the stream, have been also investigated and the main characteristics of the lock-in regime have been described. The survey is illustrated by 40 figures and completed by a table in which are reported the successive studies related to the flow around a circular cylinder based upon visualization, including a brief account of the experimental setups and methods, as well as a description of the main phenomena observed in the corresponding pictures.

scholarly journals Cosmic Ray Signatures of Different Types of Solar Wind Streams

1990 ◽  
Vol 142 ◽  
pp. 259-260
Author(s):  
P.K. Shrivastava ◽  
S.P. Agrawal
Keyword(s):  
Solar Wind ◽  
High Speed ◽  
Solar Wind Speed ◽  
Coronal Holes ◽  
Cosmic Ray ◽  
Cosmic Ray Intensity ◽  
Wind Speeds ◽  
Different Types ◽  
Speed Solar Wind ◽  
High Speed Solar Wind

The earlier concept of average solar wind speed has changed with time. Besides quiet periods of low/average solar wind speeds, two different kinds of solar sources (solar flares and coronal holes) have been identified to produce high speed solar wind streams. In an earlier investigation, it was reported that the high speed streams associated to these sources produce distinctly different effects on the cosmic ray intensity (Venkatesan, et. al., 1982).

DEFORMATION AND CRACKING OF THE PLATFORM JOINT OF THE PREFABRICATED-MONOLITHICRC BUILDING FRAME

2020 ◽  
Vol 90 (4) ◽  
pp. 38-47
Author(s):  
VL.I. KOLCHUNOV ◽  
◽  
D.V. MARTYNENKO ◽  
Keyword(s):  
Reinforced Concrete ◽  
Plane Stress State ◽  
Hollow Core ◽  
Finite Element Scheme ◽  
Element Scheme ◽  
Joint Structure ◽  
Numerical Studies ◽  
Distributed Load ◽  
Different Types ◽  
Design Characteristics

A computational model and the results of numerical studies of the structure of a platform joint in a reinforced concrete precast-monolithic frame of a building from panel-frame elements of industrial production are presented. Modeling of the plane stress state of the joint structure is carried out by a finite element scheme, using finite elements of different types and a nonlinear law of deformation to determine the design characteristics of reinforced concrete. The parameters of deformation of the platform joint structure at different loading levels, including stage-by-stage cracking and destruction, have been determined. The schemes of distribution and stress concentration zones in the characteristic sections of the platform joint are established when the distributed load is transferred from the frame of the panel-frame to the hollow-core floor panels and concrete for embedding the joint in the presence of a cavity in the frame frame for centering elements.

Synthesis and Herbicidal Activities of Novel Thiazole PPO Inhibitors

2020 ◽  
Vol 17 (2) ◽  
pp. 192-198
Author(s):  
Shu Chen ◽  
Guihua Ren ◽  
Dan Pei ◽  
Fan Zhang ◽  
Jie Liu ◽  
...  
Keyword(s):  
Petri Dish ◽  
Amaranthus Retroflexus ◽  
Inhibition Rate ◽  
Culture Dish ◽  
Protoporphyrinogen Oxidase ◽  
Nitrobenzoic Acid ◽  
Different Types ◽  
Key Enzyme ◽  
Stem Leaf ◽  
Spray Treatment

Background: Protoporphyrinogen oxidase (PPO, EC 1.3.3.4) is a key enzyme in the biosynthesis of chlorophyll and heme, also the target of different types of herbicides. Thiazole compounds shown excellent biological activity, can be designed by using active groups docking for new PPO inhibitors. Objective: The objective of this study was to synthsize a series of aryl thiazole compounds as PPO inhibitors. Methods: In this study, a series of aryl thiazole compounds derivatives 11a-l were obtained from 2- chloro-5-nitrobenzoic acid as the starting material via esterification, Iron powder reduction, diazotization, Hantzsch reaction and final acylation. All synthesized compounds have been tested for their herbicidal activities as a PPO inhibitors. Results: The Petri dish test indicated that all compounds exhibited good herbicidal activities at 200 mg/L using culture dish. And the post-emergence tests showed that at 150g.ai/ha on weed stem leaf spray treatment, some of the title compounds exhibited 80% inhibition rate against the dicotyledonou weeds Amaranthus retroflexus and Eclipta prostrate. Conclusion: Good activity was noted for some compounds that compounds 11a, 11b, 11c, 11g, 11h had 80% inhibition on stems and leaves of Amaranthus retroflexus at 150g.ai/ha.

scholarly journals Does the Opening of High-Speed Railway Lines Reduce the Carbon Intensity of China’s Resource-Based Cities?

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4648
Author(s):  
Zhipeng Tang ◽  
Ziao Mei ◽  
Jialing Zou
Keyword(s):  
High Speed ◽  
National Average ◽  
Carbon Intensity ◽  
Time Varying ◽  
Low Carbon ◽  
High Speed Railway ◽  
Different Types ◽  
Endogenous Selection ◽  
Mode Of Development ◽  
The Impact

The carbon intensity of China’s resource-based cities (RBCs) is much higher than the national average due to their relatively intensive mode of development. Low carbon transformation of RBCs is an important way to achieve the goal of reaching the carbon emissions peak in 2030. Based on the panel data from 116 RBCs in China from 2003 to 2018, this study takes the opening of high-speed railway (HSR) lines as a quasi-experiment, using a time-varying difference-in-difference (DID) model to empirically evaluate the impact of an HSR line on reducing the carbon intensity of RBCs. The results show that the opening of an HSR line can reduce the carbon intensity of RBCs, and this was still true after considering the possibility of problems with endogenous selection bias and after applying the relevant robustness tests. The opening of an HSR line is found to have a significant reducing effect on the carbon intensity of different types of RBC, and the decline in the carbon intensity of coal-based cities is found to be the greatest. Promoting migration of RBCs with HSR lines is found to be an effective intermediary way of reducing their carbon intensity.

scholarly journals Cell Bioprinting: The 3D-Bioplotter™ Case

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4005 ◽  
Author(s):  
Angelats Lobo ◽  
Ginestra
Keyword(s):  
3D Structure ◽  
Three Dimensional ◽  
Petri Dish ◽  
Two Dimensions ◽  
Point Of View ◽  
Lack Of Information ◽  
Synthetic Materials ◽  
Different Types ◽  
Available Information ◽  
User Friendly

The classic cell culture involves the use of support in two dimensions, such as a well plate or a Petri dish, that allows the culture of different types of cells. However, this technique does not mimic the natural microenvironment where the cells are exposed to. To solve that, three-dimensional bioprinting techniques were implemented, which involves the use of biopolymers and/or synthetic materials and cells. Because of a lack of information between data sources, the objective of this review paper is, to sum up, all the available information on the topic of bioprinting and to help researchers with the problematics with 3D bioprinters, such as the 3D-Bioplotter™. The 3D-Bioplotter™ has been used in the pre-clinical field since 2000 and could allow the printing of more than one material at the same time, and therefore to increase the complexity of the 3D structure manufactured. It is also very precise with maximum flexibility and a user-friendly and stable software that allows the optimization of the bioprinting process on the technological point of view. Different applications have resulted from the research on this field, mainly focused on regenerative medicine, but the lack of information and/or the possible misunderstandings between papers makes the reproducibility of the tests difficult. Nowadays, the 3D Bioprinting is evolving into another technology called 4D Bioprinting, which promises to be the next step in the bioprinting field and might promote great applications in the future.

Research of the Load Bearing Capacity of Shape-Optimized Metal Inserts Embedded in CFRP under Different Types of Stresses

2017 ◽  
Vol 742 ◽  
pp. 636-643 ◽  
Author(s):  
Florentin Pottmeyer ◽  
Markus Muth ◽  
Kay André Weidenmann
Keyword(s):  
Bearing Capacity ◽  
Residual Strength ◽  
High Speed ◽  
Systematic Research ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Temperature Cycles ◽  
Pull Out ◽  
Different Types ◽  
Impact Energies

An efficient implementation of lightweight design is the use of continuous carbon fiber reinforced plastics (CFRP) due to their outstanding specific mechanical properties. Embedded metal elements, so-called inserts, can be used to join metal-based attachments to structural CFRP parts in the context of multi-material design. They differ from other mechanical fasteners and have distinctive benefits. In particular, drilling of the components to be joined can be avoided and, depending on the preforming, fiber continuity can be maintained using such elements. Thus, no local bearing stress is anticipated. Previous work published by the authors [1] dealt with a systematic research of the influence of different types of stresses on the load bearing capacity of welded inserts. This contribution aims at the investigation of the performance of shape-optimized inserts under the same types of loading to compare with the results of the welded inserts serving as a reference. For that purpose, the respective load bearing capacities were evaluated after preinduced damages from impact tests and thermal cycling. In addition, dynamic high-speed tensile tests (pull-out) were conducted under different loading velocities. It is shown that the load bearing capacities increased up to 19% for high velocities (250 mm/s) in comparison to quasi-static loading conditions (1.5 mm/min) showing an obvious strain rate dependency of the CFRP. Quasi-static residual strength measurements under tensile loading identified the influence of the respective preinduced damages of the insert. Influence of the thermal loading condition was evaluated by placing the specimens in a climate chamber and exposing it to various numbers of temperature cycles from-40 °C to +80 °C with a duration time of 1.5 hours each. Here, it turned out that already 10 temperature cycles decreased the quasi-static load bearing capacity up to 31%. According to DIN EN 6038 the specimens were loaded with different impact energies and the residual strength were measured carrying out pull-out tests. It could be shown that the damage tolerance is significantly lower for the shape-optimized insert due to failure-critical delamination. The optimized insert also endured lower impact energies and the influence on the performance was higher.

scholarly journals The “Bag Breakup” Spume Droplet Generation Mechanism at High Winds. Part II: Contribution to Momentum and Enthalpy Transfer

2018 ◽  
Vol 48 (9) ◽  
pp. 2189-2207 ◽  
Author(s):  
Yu. Troitskaya ◽  
O. Druzhinin ◽  
D. Kozlov ◽  
S. Zilitinkevich
Keyword(s):  
High Speed ◽  
Aerodynamic Drag ◽  
Stable Stratification ◽  
Noticeable Increase ◽  
Wind Speeds ◽  
Breakup Mechanism ◽  
Hurricane Wind ◽  
Exchange Processes ◽  
Aerodynamic Drag Coefficient ◽  
High Winds

AbstractIn Part I of this study, we used high-speed video to identify “bag breakup” fragmentation as the dominant mechanism by which spume droplets are generated at gale-force and hurricane wind speeds. We also constructed a spray generation function (SGF) for the bag-breakup mechanism. The distinctive feature of this new SGF is the presence of giant (~1000 μm) droplets, which may significantly intensify the exchange between the atmosphere and the ocean. In this paper, Part II, we estimate the contribution of the bag-breakup mechanism to the momentum and enthalpy fluxes, which are known to strongly affect the development and maintenance of hurricanes. We consider three contributions to the spray-mediated aerodynamic drag: 1) “bags” as obstacles before fragmentation, 2) acceleration of droplets by the wind in the course of their production, and 3) stable stratification of the marine atmospheric boundary layer due to levitating droplets. Taking into account all of these contributions indicates a peaking dependence of the aerodynamic drag coefficient on the wind speed, which confirms the results of field and laboratory measurements. The contribution of the spray-mediated flux to the ocean-to-atmosphere moist enthalpy is also estimated using the concept of “reentrant spray,” and the equation for the enthalpy flux from a single droplet to the atmosphere is derived from microphysical equations. Our estimates show that a noticeable increase in the enthalpy exchange coefficient at winds exceeding 30–35 m s−1 is due to the enhancement of the exchange processes caused by the presence of giant droplets originating from bag-breakup fragmentation.

scholarly journals Fuel Cell designing with optimal high speed air compressor

2021 ◽  
pp. 29-38
Author(s):  
Nabeel Ahsan ◽  
Mahrukh Mehmood ◽  
Asad A. Zaidi
Keyword(s):  
Fuel Cell ◽  
High Speed ◽  
Proton Exchange Membrane ◽  
Cell System ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Air Compressor ◽  
Different Types ◽  
Input Parameters ◽  
Turbo Compressor

This paper discusses different air management technologies for fuel cell systems. Two different types of compressors are analyzed for Proton-exchange membrane fuel cells (PEMFC). Some important criteria are analyzed thoroughly for the selection of turbo compressor among different types of compressors illustrated with the help of matrix representations. The impacts of various input parameters for Fuel Cell (FC) are also explained thoroughly. Later the numerical modeling of an automobile fuel cell system using a high speed turbo-compressor for air supply is explained. The numerical model incorporates the important input parameters related with air and hydrogen. It also performed energy and mass balances across different components such as pump, fan, heat-exchanger, air compressor and also keeps in consideration the pressure drop across the flow pipes and various mechanical parts. The model is solved to obtain the characteristics of the FC system at different operating conditions. Therefore, it can be concluded that the high speed turbo compressor with a turbo-expander can have significant effects on the overall system power and efficiency.

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