Investigating the Effects of Interaction of Single-Tine and Rotating-Tine Mechanisms with Soil on Weeding Performance Using Simulated Weeds

2019 ◽  
Vol 62 (5) ◽  
pp. 1283-1291
Author(s):  
Safal Kshetri ◽  
Jafni Johari Jiken ◽  
Brian L. Steward ◽  
Lie Tang ◽  
Mehari Z. Tekeste
Keyword(s):  
Rotational Speed ◽  
Soil Depth ◽  
Soil Disturbance ◽  
Operating Conditions ◽  
Operating Parameters ◽  
Total Width ◽  
Disturbed Soil ◽  
Mechanical Tool ◽  
Two Parameters ◽  
Soil Bin

Abstract. Mechanical weeding augmented with automation technology should result in highly effective weeding systems. However, the interaction between weeding mechanisms and soil is not well understood. Moreover, soil is highly variable, which makes studying this interaction challenging. The main objective of this research was to develop a method to investigate the effects of mechanical tool-soil interaction on weeding performance for different operating conditions in a controlled environment. Experiments were conducted in an indoor soil bin with loam soil, and the weeding performance was studied using small wooden cylinders as simulated weed plants. The investigations featured a single cylindrical tine and a rotating tine mechanism, vertically oriented and inserted into the soil. The total width of soil disturbance and potential weeding rate were evaluated for the single cylindrical tine at different levels of three operating parameters: tine diameter (6.35, 7.94, and 9.53 mm), working soil depth (25.4, 50.8, and 76.2 mm), and tine speed (0.23 and 0.45 m s-1). Potential weeding rate was examined for the rotating tine mechanism with two operating parameters: working soil depth (25.4 and 76.2 mm) and rotational speed (25, 50, and 100 rpm). Statistical analysis was performed using ANOVA at p < 0.05. A simulation of the rotating tine mechanism was developed that estimated the disturbed area. For the single tine, soil disturbance width was independent of tine speed; however, tine diameter and depth had significant effects, as the width increased with increased levels of these two parameters. All three parameters had significant effects on the potential weeding rate of the single tine, and the rates were observed to increase with higher levels of the parameters. For the rotating tine mechanism, both depth and rotational speed were significant. The potential weeding rate for the rotating tine mechanism was found to increase with higher levels of these parameters. The results showed that although the width of soil disturbance due to a cylindrical tine was affected by the tine diameter and working soil depth, operating parameters such as increased longitudinal and rotational speeds also affected plant disturbance. The percentage of disturbed soil area in the simulation followed similar patterns as the percentage of disturbed plants observed in the experiments. Keywords: Inter-row weeding, Intra-row weeding, Mechanical weeding, Rotating tine mechanism, Soil disturbance, Tine.

scholarly journals Draught Requirements of Tillage Tines in Clay Soil under Indoor Soil Bin Conditions

2020 ◽  
Vol 3 (2) ◽  
pp. 1-12
Author(s):  
Feranmi Ajayi ◽  
Mouiz Yessoufou ◽  
Titilope Akinbayo
Keyword(s):  
Soil Profile ◽  
Crop Production ◽  
Clay Soil ◽  
Rake Angle ◽  
Soil Disturbance ◽  
Operating Conditions ◽  
Maximum Width ◽  
Agricultural Engineering ◽  
Tool Shape ◽  
Soil Bin

Large tine (Tl) and sweep tine (Tw) were the different model tillage tines used for this research. The blades were used on clay soil in a soil bin of dimension 9.0 × 0.85 × 0.5m located in the Department of Agricultural Engineering of the Federal University of Technology, Akure, Nigeria. The clay soil used for the experiment was obtained from Agricultural Engineering Step B Farm. The objective of this study was to evaluate the draught requirements of the model tillage tools and to evaluate and model the parameters of the soil profile produced under different operating conditions. It involved testing and evaluation of tool shape, depth (12.5 -100mm) and rake angles (300, 450, and 900) and forward speed (0.17m/sec) on draught force. Soil profile patterns measured by a profilometer was analyzed using the following parameters – maximum Width of soil cut (Wfs), Ridge-to- Ridge Distance (RRD), furrow depth (df), height of ridge (Hr), maximum Width of Soil Throw (TDW) and tool width (w). Results showed that draught is directly proportional to the depth of the tine at a certain rake angle. The Tw had the least draught while Tl had the highest draught. Analysis of soil disturbance parameters revealed an increase in parameters with increasing cone index and depth of the tines. The study provides relevant data in the design of soil engaging tools and sustainable crop production. Keywords: Draught, Clay, Soil disturbance, Tillage, Tines.

Overturning and Equilibrium Speeds and Speed Safety Margin—A Sensitivity Analysis

1985 ◽  
Vol 107 (4) ◽  
pp. 399-401
Author(s):  
Sudhir Kumar ◽  
D. L. Prasanna Rao
Keyword(s):  
Sensitivity Analysis ◽  
Safety Margin ◽  
Operating Conditions ◽  
Operating Parameters ◽  
Critical Speeds ◽  
Speed Factor ◽  
Drastic Effect ◽  
Two Parameters

Two critical speeds viz., the equilibrium speed and the overturning speed, are recognized to play an important role in defining operational and safety characteristics of railroads. An analysis of the sensitivity of the critical speeds to important operating parameters is presented. Two parameters called the ‘Speed Safety Margin’ and the ‘Speed Factor’ are defined to assist in evaluating the severity of a set of operating conditions. It is concluded that degree of curve has the most drastic effect on safety followed, in decreasing order of effect, by height of CG, superelevation, and track gage. Some comments are offered as a possible guide to safe and economical operation of railroads.

Evaluation of Inter-Row Sweeps with Different Working Widths

2017 ◽  
Vol 33 (3) ◽  
pp. 307-312
Author(s):  
Songül Gürsoy ◽  
Ying Chen
Keyword(s):  
Weed Control ◽  
Sandy Loam ◽  
Soil Disturbance ◽  
Disturbed Soil ◽  
Draft Force ◽  
Loam Soil ◽  
Soil Measurements ◽  
Soil Bin ◽  
Sweep Width ◽  
Mechanical Weed Control

Abstract. Little information is available on the performance of inter-row sweeps. The aim of this study was to evaluate the potential of inter-row sweeps for mechanical weed control. Sweeps with different working widths (153, 280, and 330 mm) were tested at different working speeds (0.70, 1.53, and 2.22 m s-1) and a constant working depth (50 mm) in an indoor soil bin with a sandy loam soil. Measurements included soil disturbance characteristics: distance of soil throw (L), width of disturbed soil (W), mass of soil throw (M), height of soil ridge (H), and draft force (Fd). Results showed that L increased linearly with the working speed, but L was not affected by the working width of the sweeps. In contrast, W was slightly affected by the speed, but it was significantly increased if a wider sweep was used. Effects of working speed on M and H depended on the sweep width, and the smallest sweep traveling at 2.22 m s-1 resulted in the highest M and H. Draft force was higher for a wider sweep and a higher working speed. Considering the potential weeding efficiency (defined as the ratio of W and Fd), the width of sweep would not make any differences, and a lower working speed would result in better performance. Keywords: Draft force, Inter-row, Soil disturbance, Speed, Sweep, Weeding.

Relationships between Population Dynamics and Operating Parameters in an Activated Sludge-Plant by Statistical Analysis

1992 ◽  
Vol 25 (4-5) ◽  
pp. 399-400 ◽  
Author(s):  
L. Cingolani ◽  
M. Cossignani ◽  
R. Miliani
Keyword(s):  
Population Dynamics ◽  
Statistical Analysis ◽  
Activated Sludge ◽  
Treatment Plant ◽  
Operating Conditions ◽  
Statistical Analyses ◽  
Operating Parameters ◽  
Aerobic Treatment

Statistical analyses were applied to data from a series of 38 samples collected in an aerobic treatment plant from November 1989 to December 1990. Relationships between microfauna structure and plant operating conditions were found. Amount and quality of microfauna groups and species found in activated sludge proved useful to suggest the possible causes of disfunctions.

scholarly journals The Soil Organic Matter in Connection with Soil Properties and Soil Inputs

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 779
Author(s):  
Václav Voltr ◽  
Ladislav Menšík ◽  
Lukáš Hlisnikovský ◽  
Martin Hruška ◽  
Eduard Pokorný ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Texture ◽  
Management Practices ◽  
Soil Depth ◽  
Operating Conditions ◽  
Hot Water ◽  
Natural Soil ◽  
Soil Productivity ◽  
Linear Regression Models

The content of organic matter in the soil, its labile (hot water extractable carbon–HWEC) and stable (soil organic carbon–SOC) form is a fundamental factor affecting soil productivity and health. The current research in soil organic matter (SOM) is focused on individual fragmented approaches and comprehensive evaluation of HWEC and SOC changes. The present state of the soil together with soil’s management practices are usually monitoring today but there has not been any common model for both that has been published. Our approach should help to assess the changes in HWEC and SOC content depending on the physico-chemical properties and soil´s management practices (e.g., digestate application, livestock and mineral fertilisers, post-harvest residues, etc.). The one- and multidimensional linear regressions were used. Data were obtained from the various soil´s climatic conditions (68 localities) of the Czech Republic. The Czech farms in operating conditions were observed during the period 2008–2018. The obtained results of ll monitored experimental sites showed increasing in the SOC content, while the HWEC content has decreased. Furthermore, a decline in pH and soil´s saturation was documented by regression modelling. Mainly digestate application was responsible for this negative consequence across all soils in studied climatic regions. The multivariate linear regression models (MLR) also showed that HWEC content is significantly affected by natural soil fertility (soil type), phosphorus content (−30%), digestate application (+29%), saturation of the soil sorption complex (SEBCT, 21%) and the dose of total nitrogen (N) applied into the soil (−20%). Here we report that the labile forms (HWEC) are affected by the application of digestate (15%), the soil saturation (37%), the application of mineral potassium (−7%), soil pH (−14%) and the overall condition of the soil (−27%). The stable components (SOM) are affected by the content of HWEC (17%), soil texture 0.01–0.001mm (10%), and input of organic matter and nutrients from animal production (10%). Results also showed that the mineral fertilization has a negative effect (−14%), together with the soil depth (−11%), and the soil texture 0.25–2 mm (−21%) on SOM. Using modern statistical procedures (MRLs) it was confirmed that SOM plays an important role in maintaining resp. improving soil physical, biochemical and biological properties, which is particularly important to ensure the productivity of agroecosystems (soil quality and health) and to future food security.

scholarly journals A Numerical Investigation into the PAT Hydrodynamic Response to Impeller Rotational Speed Variation

2021 ◽  
Vol 13 (14) ◽  
pp. 7998
Author(s):  
Maxime Binama ◽  
Kan Kan ◽  
Hui-Xiang Chen ◽  
Yuan Zheng ◽  
Daqing Zhou ◽  
...  
Keyword(s):  
Rotational Speed ◽  
Distribution Systems ◽  
Water Distribution ◽  
Production Efficiency ◽  
Operating Conditions ◽  
Energy Regulation ◽  
Speed Increase ◽  
Energy Field ◽  
Long Run ◽  
Study Results

The utilization of pump as turbines (PATs) within water distribution systems for energy regulation and hydroelectricity generation purposes has increasingly attracted the energy field players’ attention. However, its power production efficiency still faces difficulties due to PAT’s lack of flow control ability in such dynamic systems. This has eventually led to the introduction of the so-called “variable operating strategy” or VOS, where the impeller rotational speed may be controlled to satisfy the system-required flow conditions. Taking from these grounds, this study numerically investigates PAT eventual flow structures formation mechanism, especially when subjected to varying impeller rotational speed. CFD-backed numerical simulations were conducted on PAT flow under four operating conditions (1.00 QBEP, 0.82 QBEP, 0.74 QBEP, and 0.55 QBEP), considering five impeller rotational speeds (110 rpm, 130 rpm, 150 rpm, 170 rpm, and 190 rpm). Study results have shown that both PAT’s flow and pressure fields deteriorate with the machine influx decrease, where the impeller rotational speed increase is found to alleviate PAT pressure pulsation levels under high-flow operating conditions, while it worsens them under part-load conditions. This study’s results add value to a thorough understanding of PAT flow dynamics, which, in a long run, contributes to the solution of the so-far existent technical issues.

Prediction of gaseous pollutant emissions from a spark-ignition direct-injection engine with gas-exchange simulation

2021 ◽  
pp. 146808742110050
Author(s):  
Stefania Esposito ◽  
Lutz Diekhoff ◽  
Stefan Pischinger
Keyword(s):  
Gas Exchange ◽  
Combustion Chamber ◽  
Direct Injection ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Operating Parameters ◽  
Gaseous Pollutant ◽  
Fuel Ratio ◽  
No Emissions

With the further tightening of emission regulations and the introduction of real driving emission tests (RDE), the simulative prediction of emissions is becoming increasingly important for the development of future low-emission internal combustion engines. In this context, gas-exchange simulation can be used as a powerful tool for the evaluation of new design concepts. However, the simplified description of the combustion chamber can make the prediction of complex in-cylinder phenomena like emission formation quite challenging. The present work focuses on the prediction of gaseous pollutants from a spark-ignition (SI) direct injection (DI) engine with 1D–0D gas-exchange simulations. The accuracy of the simulative prediction regarding gaseous pollutant emissions is assessed based on the comparison with measurement data obtained with a research single cylinder engine (SCE). Multiple variations of engine operating parameters – for example, load, speed, air-to-fuel ratio, valve timing – are taken into account to verify the predictivity of the simulation toward changing engine operating conditions. Regarding the unburned hydrocarbon (HC) emissions, phenomenological models are used to estimate the contribution of the piston top-land crevice as well as flame wall-quenching and oil-film fuel adsorption-desorption mechanisms. Regarding CO and NO emissions, multiple approaches to describe the burned zone kinetics in combination with a two-zone 0D combustion chamber model are evaluated. In particular, calculations with reduced reaction kinetics are compared with simplified kinetic descriptions. At engine warm operation, the HC models show an accuracy mainly within 20%. The predictions for the NO emissions follow the trend of the measurements with changing engine operating parameters and all modeled results are mainly within ±20%. Regarding CO emissions, the simplified kinetic models are not capable to predict CO at stoichiometric conditions with errors below 30%. With the usage of a reduced kinetic mechanism, a better prediction capability of CO at stoichiometric air-to-fuel ratio could be achieved.

Measurement of Unsteady Flow in Pump-Turbine for Hydropower Using PIV Method

2009 ◽  
Author(s):  
Nobuhiko Fukuda ◽  
Satoshi Someya ◽  
Koji Okamoto
Keyword(s):  
Rotational Speed ◽  
Velocity Measurement ◽  
Numerical Procedure ◽  
Hydraulic Turbine ◽  
Operating Conditions ◽  
High Time ◽  
Pump Turbine ◽  
Guide Vanes ◽  
Runner Blade ◽  
Wide Range

It is thought that the pressure fluctuation can occur due to the interaction between flow through guide vanes and flow into runner blades, resulting in a vibration of turbine and a blade cracking, in a hydraulic turbine operated in a wide range for flexible power demand. High accurate velocity measurement with high time/spatial resolution can help to clarify the mechanism of the interaction and to provide good experimental data for the validation of numerical procedure. So the aim of present study is to estimate the unstable velocity field quantitatively in the area between guide vanes and runner blades, using high time-resolved particle image velocimetry (PIV). Two types of velocity measurements were carried out, i.e., phase-locked measurement and high time sequential velocity measurement, in a pump-turbine model with 20 guide vanes and 6 runner blades. The characteristic of the flow field varied corresponding to the operating conditions such as flow rate and rotational speed. Opening angles of guide vanes were kept uniform. A clockwise vortex was generated at inside of the runner blade under smaller rotational speed. A counterclockwise vortex was separated at the backside of the runner blade under higher rotational speed. At any operating conditions, the velocity between guide vanes and runner blades oscillated periodically at the blade passing frequency.

Fractal Analysis for Vibrational Signals Created in a Ball-Screw Machine Operating in Short- and Long-Range Tribological Tests

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Min-Chi Chang ◽  
Jeng Luen Liou ◽  
Chin-Chung Wei ◽  
Jeng-Haur Horng ◽  
Yueh-Ling Chiu ◽  
...  
Keyword(s):  
Long Range ◽  
Fractal Analysis ◽  
Rotational Speed ◽  
Operating Conditions ◽  
Ball Screw ◽  
Frictional Torque ◽  
A Value ◽  
Vibrational Signals ◽  
Inner Surface ◽  
Range Test

In the present study, the vibrational and frictional torque signals acquired from the forward-backward movements of a commercial ball-screw system were considered via mono fractal analysis. The short-range tests were carried out in order to investigate the effects of operating conditions, a nut's inner surface roughness and the applied pretension (preload) on the fractal dimension (Ds) and topothesy (G). The long-range test was conducted to observe the variations of vibrational and frictional torque signals and thus the fractal parameters acquired from the ball-screw operations under the condition of no fresh grease supply during the testing process. The effects of the ball-screw rotational speed and pretension on the G parameter of vibrations were greater than the Ds parameter. In the backward movement, the highest G value always occurred at the highest rotational speed (3000 rpm in this study). The Ds parameter generated in the forward movement by the nut's inner surface before polishing produced a value greater than that by the nut with a polished surface. The G parameter related to vibrational amplitudes showed a value before polishing greater than that after polishing. The unusual vibrational signals are assumed to be related to ball passing behavior. Their experimental frequency was verified to be consistent with the frequency predicted by the ball pass theory. An increase in the rotational speed can bring a significant increase in the number of ball-pass signals. The G parameter and its skewness data, defined for the number distribution function of the G peaks, showed values that in general increased with the test time if the fresh grease was not supplied during the long-range test.

Performance Analysis of a Biomass Gasifier Genset at Varying Operating Conditions

2018 ◽  
Vol 34 (1) ◽  
pp. 135-143 ◽  
Author(s):  
Kyle D Palmer ◽  
Mark A Severy ◽  
Charles E Chamberlin ◽  
Anthony J. Eggink ◽  
Arne E Jacobson
Keyword(s):  
Renewable Energy ◽  
Biomass Conversion ◽  
Catalytic Converter ◽  
Operating Conditions ◽  
Diesel Generator ◽  
Forest Operations ◽  
Coast Redwood ◽  
Moisture Contents ◽  
Two Parameters ◽  
Conversion Technologies

Abstract. An All Power Labs PP20 gasifier generation set (Berkeley, Calif.) was tested to evaluate its suitability for powering biomass conversion technologies (BCT) at remote forest operations sites. Feedstock of the species tanoak (), coast redwood (), and Douglas fir () were tested at moisture contents of 15% and 25% (wet basis). The PP20 was connected to a load bank with five different load profiles designed to simulate possible BCT loads. Two parameters of power quality, voltage variability, and frequency deviation, were determined to be within acceptable limits. The unit also successfully powered a remote biochar operation in Branscomb, California. Emissions of the PP20, when compared to diesel generator regulations, would meet non-methane hydrocarbons (NMHC) and NOX requirements but exceed the CO emissions limits by a factor of ten. The CO emissions could be reduced by adding a catalytic converter. The results indicate that it is possible to use a PP20 unit to provide electric power for the highly variable loads of a BCT system. Keywords: Bioenergy, Biomass conversion technology, Gasification, Renewable energy.

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