Weeding performance of a spring-tine harrow as affected by timing and operational parameters

Weed Science ◽  
2020 ◽  
pp. 1-38
Author(s):  
Zhiwei Zeng ◽  
Amy Martin ◽  
Ying Chen ◽  
Xu Ma
Keyword(s):  
Performance Indicators ◽  
Cutting Forces ◽  
Crop Damage ◽  
Operational Parameters ◽  
Dominant Effect ◽  
Control Efficacy ◽  
Weed Density ◽  
Soil Cutting ◽  
Soil Bin ◽  
Performance And Mechanism

Abstract Spring-tine harrow is gaining popularity for mechanical weeding. However, its weeding performance and mechanism have not been well understood. A spring-tine harrow was first tested in a controlled indoor soil bin at four different travel speeds (4, 6, 8, and 10 km h-1) with three different spring loading settings (low, medium, and high). Then the harrow was tested in a wheat (Triticum aestivum L.) field at the same spring loading settings at three different weeding timings (early, middle, and late) in 2019 and 2020. Soil cutting forces (draft and vertical), soil displacements (forward and lateral), soil working depth, weed control efficacy, weed density, and crop damage were measured. The results showed that the spring loading setting had a more dominant effect on working depth and soil cutting forces than the speed. The soil displacements were more dependent on the speed as compared to the spring loading setting. Treatments effects on weeding performance indicators in the field were similar across years. Adjusting the spring loading setting from low to high improved the weeding efficacy from 44.9% to 73.9% in 2019 and from 51.6% to 78.1% in 2020. Consequently, the final weed density was minimized at the high-loading setting with the reduction in 2020 being significant. The middle weeding timing caused the minimum crop damage while reducing the final weed density by approximately one third as compared to the control (without mechanical weeding), which was most desired among the three timings tested.

Instrumented Soil Bin for Testing Soil-Engaging Tools

2017 ◽  
Vol 33 (3) ◽  
pp. 357-366 ◽  
Author(s):  
Muhammad R. Mahadi ◽  
Ying Chen ◽  
Pieter Botha
Keyword(s):  
Tilt Angle ◽  
Cutting Forces ◽  
Travel Speed ◽  
Operational Parameters ◽  
Precise Control ◽  
Test Tool ◽  
Speed Up ◽  
Draft Force ◽  
Soil Cutting ◽  
Soil Bin

Abstract. An indoor soil bin was developed in this study for testing soil-engaging tools. The design criteria included that the soil bin had to be compact, well controlled in its operational parameters, instrumented to measure soil cutting forces, and be safe to operate. The test tool could travel at any specific speed, up to 8 km h-1. A compact dynamometer was designed for the soil bin for measuring soil cutting forces in three directions. The calibration results of the dynamometer showed a linear relationship between the loads and the output voltages, with coefficients of determination of 0.99. The cross sensitivity between the directions was from 0.31% to 4.7%. The soil bin and the dynamometer were tested using a disc operated at three values of tilt angle of 0°, 10°, and 20°. The test results showed that the soil bin allowed precise control of the tool travel speed and working depth in the designed ranges. Forces of the disc had an increase in vertical and lateral forces, and decrease in draft force, with the increase in tilt angle. These trends are in line with other studies in the literature. The results proved the full-functioning status of the soil bin and the dynamometer. Keywords: Calibration, Design, Disc, Dynamometer, Soil bin, Test, Tilt angle.

scholarly journals Comparison of soil and corn residue cutting performance of different discs used for vertical tillage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhiwei Zeng ◽  
Dillon Thoms ◽  
Ying Chen ◽  
Xu Ma
Keyword(s):  
Cutting Forces ◽  
Crop Residue ◽  
Conservation Agriculture ◽  
Cutting Performance ◽  
Promising Practice ◽  
Corn Residue ◽  
Different Shapes ◽  
Soil Cutting ◽  
Soil Bin ◽  
Corn Residues

AbstractHigh amount of corn (Zea mays L.) residue left in the field interferes with seeding operations, which hinders the viability of conservation agriculture. Vertical tillage is a promising practice in dealing with heavy crop residue, but its effectiveness largely depends on the design and use of tillage machines. In this study, three vertical tillage discs with different shapes, namely notched, plain, and rippled, were tested in a soil bin at two different working depths, shallow (63.5 mm) and deep (127 mm). Corn residues were spread on top of the soil as surface residue. soil cutting forces, soil displacement, and residue mixing with soil, as well as residue cutting were measured. The results showed that the working depth had a stronger effect on the performance of discs as compared to the disc type. No difference in residue cutting was found between the treatments. The deep working depth resulted in 5.1% higher residue mixing, 53.4% greater soil cutting forces, and 34.9% larger soil displacements, as compared to the shallow depth. The rippled disc resulted in the largest soil displacements with the greatest demand in soil cutting forces. Overall, the rippled disc was the most aggressive among the three discs with regard to the performance indicators measured. The results suggested that varying working depth would be an effective approach in changing the soil dynamics and residue cutting performance of the discs for vertical tillage.

Forecasting of Cutting Forces in Dental Adjustment of Ceramic Prostheses Using an Artificial Neural Network

2010 ◽  
Vol 152-153 ◽  
pp. 1687-1690
Author(s):  
Jian Hui Peng ◽  
Xiao Fei Song ◽  
Ling Yin
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Cutting Forces ◽  
High Speed ◽  
Cutting Process ◽  
Computer Assisted ◽  
Ann Model ◽  
Operational Parameters ◽  
Artificial Neural

Intraoral adjustment of ceramic prostheses involving cutting process is a central procedure in restorative dentistry because the quality of ceramic prostheses depends on the cutting process. In this paper, an artificial neural network (ANN) model was developed for the first time to forecast the dynamic forces in dental cutting process as functions of clinical operational parameters. The predicted force values were compared with the measured values in in vitro dental cutting of porcelain prostheses obtained using a novel two-degrees-of-freedom computer-assisted testing apparatus with a high-speed dental handpiece and diamond burs. The results indicate that there existed nonlinear relationships between the cutting forces and clinical operational parameters. It is found that the ANN-forecasted forces were in good agreement with the experiment-measured values. This indicates that the established ANN model can provide insights into the force-related process assessment and forecast for clinical dental cutting of ceramic prostheses.

scholarly journals Study on the Interaction between Soil and the Five-Claw Combination of a Mole Using the Discrete Element Method

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yuwan Yang ◽  
Mo Li ◽  
Jin Tong ◽  
Yunhai Ma
Keyword(s):  
Discrete Element Method ◽  
Discrete Element ◽  
Rake Angle ◽  
Soil Resistance ◽  
Distance Ratio ◽  
Soil Failure ◽  
Soil Cutting ◽  
Soil Bin ◽  
Rupture Distance ◽  
Element Method

A mole is a born digger spending its entire existence digging tunnels. The five claws of a mole’s hand are combinative to cut soil powerfully and efficiently. However, little was known in detail about the interaction between the soil and the five-claw combination. In this study, we simulated the soil cutting process of the five-claw combination using the discrete element method (DEM) as an attempt for the potential design of soil-engaging tools to reduce soil resistance. The five-claw combination moved horizontally in the soil bin. Soil forces (draught and vertical forces) and soil failure (soil rupture distance ratio) were measured at different rake angles and speeds. Results showed that the draught and vertical forces varied nonlinearly as the rake angle increased from 10 to 90°, and both changed linearly with the speed increasing from 1 to 5 m/s. The curve of the soil rupture distance ratio with rake angles could be better described using a quadric function, but the speed had little effect on the soil rupture distance ratio. Notably, the soil rupture distance ratio of the five-claw combination in simulation was on average 19.6% lower than the predicted ratio of simple blades at different rake angles indicating that the five-claw combination could make less soil failure and thereby produce lower soil resistance. Given the draught and vertical forces, the performance of the five-claw combination was optimized at the rake angle of 30°.

Weed management in white beans with postemergence herbicide tankmixes

2013 ◽  
Vol 93 (4) ◽  
pp. 669-674 ◽  
Author(s):  
Nader Soltani ◽  
Robert E. Nurse ◽  
Peter H. Sikkema
Keyword(s):  
Adverse Effect ◽  
Weed Control ◽  
Weed Management ◽  
Field Studies ◽  
Control Efficacy ◽  
Weed Density ◽  
Herbicide Treatments ◽  
White Bean ◽  
Effect On Yield ◽  
Density And Biomass

Soltani, N., Nurse, R. E. and Sikkema, P. H. 2013. Weed management in white beans with postemergence herbicide tankmixes. Can. J. Plant Sci. 93: 669–674. Weed control efficacy of cloransulam-methyl, halosulfuron, bentazon, fomesafen and their tankmixes applied post-emergence (POST) for weed management in white bean was evaluated in field studies conducted in four Ontario locations during 2008–2011. Cloransulam-methyl, halosulfuron, bentazon, fomesafen, bentazon plus fomesafen, cloransulam-methyl plus bentazon, cloransulam-methyl plus fomesafen, cloransulam-methyl plus bentazon plus fomesafen, halosulfuron plus bentazon, halosulfuron plus fomesafen, and halosulfuron plus bentazon plus fomesafen caused white bean injury ranging from 1 to 18%. Control for AMARE, AMBEL and CHEAL ranged from 47 to 92%, 66 to 98% and 36 to 91%, respectively, among herbicide treatments. Similar results were observed for weed density and biomass of AMARE, AMBEL, and CHEAL. Cloransulam-methyl, halosulfuron, and cloransulam-methyl plus fomesafen reduced the yield of white bean by 34, 21, and 17%, respectively, compared with the weed-free control. However, bentazon, fomesafen, bentazon plus fomesafen, cloransulam-methyl plus bentazon, cloransulam-methyl plus bentazon plus fomesafen, halosulfuron plus bentazon, halosulfuron plus fomesafen, and halosulfuron plus bentazon plus fomesafen had no adverse effect on yield of white bean. Based on these results, tankmixes of cloransulam-methyl and halosulfuron with bentazon and fomesafen can reduce crop injury and provide control of broadleaf weeds in white bean.

Prediction of Flow and Combustion Characteristics for a Gas Turbine Combustor Burning Low Heating Value Fuel

2010 ◽  
Author(s):  
M. R. Shaalan ◽  
H. A. El Salmawy ◽  
M. Anwar Ismail
Keyword(s):  
Gas Turbine ◽  
Performance Indicators ◽  
Substantial Reduction ◽  
Combustion Characteristics ◽  
Swirl Ratio ◽  
Operational Parameters ◽  
Gas Turbine Combustor ◽  
Heating Value ◽  
Secondary Air ◽  
The Impact

In this study, a numerical model has been developed to simulate the flow and combustion in a gas turbine combustor of type (Winnox-TUD-Combustor), which burns low heating value gas. The model relies on the computational code “FLUENT”. This code has been used to solve the governing equations. The characteristics of the model are; steady, turbulent, two dimensional, axisymmetric and swirling flow. The combustion process has been simulated as non-premixed combustion. The study includes the impact of several design and operational parameters on the characteristics of the flow and combustion inside the combustion chamber. These parameters include; ratio of secondary to primary air, ratio of tertiary to primary air, swirl ratio, number of inlets of the secondary air and their direction. Four performance indicators have been used to evaluate the impact of the aforementioned design and operating parameters. These indicators include; average temperature of the exhaust gases to the turbine, specific NOx emission, pattern factor and combustion efficiency of the combustor. In order to identify the optimum values of the aforementioned design and operational parameters, Artificial Neural Network (ANN) technique has been utilized to enrich the output results. This facilitates searching for the optimum values of the aforementioned parameters. Furthermore the effect of the variations in fuel composition on the combustion characteristics and accordingly on the performance indicators has been studied. It has been found that, all the studied parameters affect the performance of the combustor to a certain extent. However, fuel swirl ratio, primary to secondary air ratio and tertiary to primary air ratio as well as carbon monoxide to hydrogen ratio in the fuel are the controlling factors. Optimizing these parameters can lead to a substantial reduction in specific NOx emissions down to 4.0 gm/kg of fuel. Also an improvement in pattern factor to values below 0.3 has been achieved.

Tank Mixing Saflufenacil, Glufosinate, and Indaziflam Improved Burndown and Residual Weed Control

2013 ◽  
Vol 27 (2) ◽  
pp. 422-429 ◽  
Author(s):  
Amit J. Jhala ◽  
Analiza H. M. Ramirez ◽  
Megh Singh
Keyword(s):  
Weed Control ◽  
Broad Spectrum ◽  
Field Experiments ◽  
Additive Effect ◽  
Control Efficacy ◽  
Weed Density ◽  
Florida Citrus ◽  
Density And Biomass ◽  
Grass Weed

Saflufenacil and indaziflam, POST and PRE herbicides, respectively, have been registered recently for weed control in Florida citrus. Glufosinate is under evaluation and may be registered in the future for POST weed control in citrus. Citrus growers often want to have a tank mixture of herbicides that provide broad-spectrum weed control. Saflufenacil is a broadleaf herbicide and needs to be tank mixed with other herbicide(s) to increase weed control spectrum. Information is not available on interaction of saflufenacil, glufosinate, and indaziflam applied in tank mixtures on weed control efficacy. Greenhouse and field experiments were conducted at two locations (Polk and Orange County, FL) to evaluate the efficacy and potential antagonism or synergy of saflufenacil and glufosinate applied in tank mixes, and various three-way mixes with indaziflam. The results suggested that tank mixing saflufenacil with glufosinate had no effect on grass weed control, but had additive effect on broadleaf weed control. Indaziflam tank mixed at the recommended label rate (0.073 kg ha−1) provided better residual weed control compared with the lower rate (0.05 kg ha−1). Tank mixing indaziflam with saflufenacil and glufosinate improved broadleaf and grass weed control, reduced weed density, and biomass compared with tank mixing saflufenacil and glufosinate. Tank mixing indaziflam at 0.073 kg ha−1with saflufenacil and glufosinate provided ≥ 88% control of broadleaf and grass weeds at 30 d after treatment (DAT), and it was comparable with tank mixing saflufenacil, glyphosate and pendimethalin. This treatment combination recorded the lowest weed density (≤ 7 plants m−2) and biomass (< 80 g m−2) at 60 DAT. Glyphosate applied alone was less effective than tank mixing with saflufenacil and glufosinate for broadleaf and grass weed control. This indicates additive effect of tank mixture on glyphosate efficacy. It is concluded that saflufenacil can be tank mixed with glufosinate for control of broadleaf and grass weeds; however, addition of indaziflam in tank mixture provided long-term, broad-spectrum weed control in Florida citrus compared with other treatments.

FINITE ELEMENT MODELLING OF TILLAGE TOOL DESIGN

1993 ◽  
Vol 17 (2) ◽  
pp. 257-269 ◽  
Author(s):  
R.L. Kushwaha
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Rake Angle ◽  
Interface Elements ◽  
Tool Shape ◽  
Soil Cutting ◽  
Soil Bin ◽  
The Finite Element Model

A non-linear finite element model was developed for three dimensional soil cutting by tillage tools. A hyperbolic constitutive relation for soil was used in the model. Analysis was carried out to simulate soil cutting with rectangular flat and triangular tillage blades at different rake angles and with curved blades. Interface elements were used to model the adhesion and the friction between soil and blade surface. Soil forces obtained from the finite element model for the straight blades were verified with the results from laboratory tillage tests in the soil bin. The finite element model predicted draft force accurately for both tillage tools. Results indicated that the draft was a function of rake angle, tool shape and the curvature.

Functionality and efficacy of Franklin Robotics’ Tertill™ robotic weeder

2020 ◽  
pp. 1-5
Author(s):  
Johnny Sanchez ◽  
Eric R. Gallandt
Keyword(s):  
Cost Effective ◽  
Soil Disturbance ◽  
Annual Grass ◽  
Control Efficacy ◽  
Weed Density ◽  
Farm Scale ◽  
Agricultural Weeds ◽  
Robotic Weeding ◽  
Important Design ◽  
Effective Design

Abstract Agricultural weeds remain an important production constraint, with labor shortages and a lack of new herbicide options in recent decades making the problem even more acute. Robotic weeding machines are a possible solution to these increasingly intractable weed problems. Franklin Robotics’ Tertill™ is an autonomous weeding robot designed for home gardeners that relies on a minimalistic design to be cost-effective. The objectives of this study were to investigate the ability of the Tertill to control broadleaf and grass weeds, and based on early observations, experiments were conducted with and without its string-trimmer–like weeding implement. Tertill demonstrated high weed-control efficacy, supporting its utility as a tool for home gardeners. Weeds were best controlled by the combined effect of soil disturbance caused by the action of the robot’s wheels and the actuation of the string trimmer. Despite the regrowth potential of an annual grass due to its meristem location, Tertill maintained low densities of millet in an experimental arena. The simple and effective design of the Tertill may offer insights to inform future development of farm-scale weeding robots. Weed density, emergence periodicity, robot working rate, and robotic weeding mechanisms are important design criteria regardless of the technology used for plant detection.

scholarly journals Meander And Koch Hybrid Fractal Curve Based Dual Hexagonal Radiating Patch Antenna For Quad Band Wireless Applications

2021 ◽  
Author(s):  
Jagtar Singh Sivia ◽  
Sumeet Singh Bhatia
Keyword(s):  
Performance Indicators ◽  
Patch Antenna ◽  
Ground Plane ◽  
The Other ◽  
Fractal Antenna ◽  
Operational Parameters ◽  
Fractal Curve ◽  
Wireless Applications ◽  
Coefficient Of Reflection ◽  
Operational Frequency

Abstract A unique dual hexagonal-shaped radiating patch design with hybrid fractal curves (Meander and Koch) is presented for quad-band wireless applications. Initially, the antenna from 0th to 2nd iteration of hybrid fractal curves with PGP (Partial Ground Plane) is designed and investigated. Further, to get better results of the designed antenna in respect of Bandwidth (BW) and coefficient of reflection these hybrid curves are superimposed on the limited ground plane of 1st and 2nd iteration of the antenna, and the generated antennas are designated as Antenna – 1 and Antenna – 2. A comparison between both the antennas has been made and it is observed that antenna -2 shows better results in respect of improved BW and coefficient of reflection. The proposed antenna exhibits four resonant frequency bands 1.6, 4.8, 6.9, and 8.8GHz with improved corresponding impedance BW of 2.09, 1.36, 0.86, and 1.51GHz. The designed antenna is simulated and made on FR4 glass epoxy substrate with an overall size of 20×40×1.6 mm3. The fabricated proposed antenna is tested experimentally for the authentication of simulated results with experimental results and these are compatible with each other. The other performance indicators like radiation pattern, peak realized gain, and radiation efficiency are also determined for the proposed Hybrid Fractal Antenna (HFA) and all are found satisfactory. Due to the improved operational parameters, the designed HFA can be considered as a suitable applicant for distinct wireless applications in anticipated operational frequency ranges.

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