scholarly journals Design and Testing of a Pneumatic Oscillating Chinese Wolfberry Harvester

Horticulturae ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 214
Author(s):  
Yun Chen ◽  
Jian Zhao ◽  
Guangrui Hu ◽  
Jun Chen
Keyword(s):  
Flow Rate ◽  
Oscillation Frequency ◽  
Orthogonal Test ◽  
Airflow Rate ◽  
Damage Rate ◽  
Flow Field Characteristics ◽  
Outlet Flow ◽  
Computational Fluid Dynamics Cfd ◽  
Fruit Damage ◽  
Design And Testing

A pneumatic oscillating Chinese wolfberry harvester was designed to improve the efficiency of manual harvesting and minimize fruit damage by mechanical harvesting. The shedding model of Chinese wolfberry under pneumatic forces was established based on kinetic analysis, and the flow field characteristics were investigated using computational fluid dynamics (CFD). The position and shape of the fan outlet were determined by comparing the effects of a linear reduction outlet and a Laval reduction outlet on the outlet airflow rate. The size of the oscillating mechanism was optimized with nonlinear constraints to achieve uniform oscillation of the airflow. A three-factor, three-level orthogonal test was conducted on the NingQi 7 wolfberry variety. The flow rate at the outlet, the oscillation frequency, and the outlet distance were the test factors, and the net harvesting rate of ripe fruits, the harvesting rate of green fruits, and the damage rate of ripe fruits were the test indices. The results showed that the net harvesting rate of ripe fruits was 85.21% at an outlet distance of 10 cm, an outlet flow rate of 70 m·s−1, and an oscillation frequency of 2 Hz. This study provides references for the design of pneumatic harvesters for Chinese wolfberry.

Bed behavioral assessment of tomato varieties in Cote d Ivoire

2015 ◽  
Vol 5 (1) ◽  
pp. 513-522
Author(s):  
Jean-Claude N'ZI ◽  
Lassina FONDIO ◽  
Mako Francois De Paul N’GBESSO ◽  
Andé Hortense DJIDJI ◽  
Christophe KOUAME
Keyword(s):  
Behavioral Assessment ◽  
Development Stage ◽  
Research Centre ◽  
Vegetative Development ◽  
Potential Yield ◽  
Tomato Plants ◽  
Bacterial Diseases ◽  
Damage Rate ◽  
Fruit Damage ◽  
Tomato Breeding

Thirty accessions of tomato including twenty eight introduced accessions from The World Vegetable Center-AVRDC and as controls, two commercial varieties Mongal and Calinago, were assessed for agronomic performances at the Experimentation and Production Station of Angud dou of the National Agronomic Research Centre (CNRA) located in the South of Cote d Ivoire. The trial was arranged in a randomized block with three replications. The following parameters were determined at vegetative development stage: plant height at flowering stage, susceptibility of accessions to diseases, day to 50% flowering and day of first harvest, production duration, fruit length, fruit diameter, total number of fruits, number of fruits per plant, potential yield, net yield and fruit damage rate. Results showed that the commercial variety Mongal, with a potential yield of 15.9 and a net yield of 13.1 t ha-1, was the most productive. All the introduced accessions from AVRDC recorded the lowest potential yields from 2.2 to 9.7 t ha-1, and net yields from 1.7 to 8.6 t ha-1. In addition, accessions WVCT8, FMTT847 and WVCT13 were severely infested by bacterial wilt. The reduction of the net yield of tomato accessions resulted in the high fruit damage rates. For the future tomato breeding work, it would be appropriate to introduce into the trials bacterial diseases tolerant varieties. Moreover, some studies could be undertaken to determine the nature of the bacteria involved in the plant wilting and to find out the causal agent of the tomato plants burning at the fructification stage reducing the harvest duration.

Evaluation of Design Characteristics for Animal Mortality Composting Systems

2021 ◽  
Vol 65 (1) ◽  
pp. 23-30
Author(s):  
Tiago Costa ◽  
Neslihan Akdeniz
Keyword(s):  
Moisture Content ◽  
Linear Relationship ◽  
Compressive Stress ◽  
Flow Rate ◽  
Volumetric Flow Rate ◽  
Airflow Rate ◽  
List Type ◽  
Design Characteristics ◽  
The Impact ◽  
Composting Systems

HighlightsDesign characteristics for animal mortality compost cover materials were tested.Compressive stress was applied to simulate the effects of the mortalities on cover materials.The highest permeability was measured for sawdust at 25% moisture content.A linear relationship was found between the volumetric flow rate and the power required to aerate the piles.Abstract. Composting is an aerobic process that relies on natural aeration to maintain proper oxygen levels. Air-filled porosity, mechanical strength, and permeability are among the essential parameters used to optimize the process. This study’s objective was to measure the physical parameters and airflow characteristics of three commonly used cover materials at four moisture levels, which could be used in designing actively aerated swine mortality composting systems. A laboratory-scale experiment was conducted to measure pressure drops across the cover materials as a function of the airflow rate and the material’s moisture content. Compressive stress was applied for 48 h to simulate the impact of swine mortalities on the cover materials. The power required to aerate each material was determined as a function of volumetric flow rate and moisture content. As expected, air-filled porosity and permeability decreased with increasing bulk density and moisture content. The highest average permeability values were measured at 25% moisture content and ranged from 66 × 10-4 to 70 × 10-4 mm2, from 161 × 10-4 to 209 × 10-4 mm2, and from 481 × 10-4 to 586 × 10-4 mm2 for woodchips, ground cornstalks, and sawdust, respectively. For the range of airflow rates tested in this study (0.0025 to 0.0050 m3 s-1 m-2), a linear relationship (R2 = 0.975) was found between the volumetric flow rate (m3 s-1) and the power required to aerate the compost pile (W per 100 kg of swine mortality). Keywords: Airflow, Darcy’s law, Livestock, Modeling, Permeability, Pressure drop.

scholarly journals Effect of hydraulic and geometric factors upon leakage flow rate in pressurized pipes

RBRH ◽  
2021 ◽  
Vol 26 ◽  
Author(s):  
Mayara Francisca da Silva ◽  
Fábio Veríssimo Gonçalves ◽  
Johannes Gérson Janzen
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Rate ◽  
Leakage Flow ◽  
Cfd Simulations ◽  
Mean Velocity ◽  
Leakage Flow Rate ◽  
Geometric Factors ◽  
Leakage Area ◽  
Computational Fluid Dynamics Cfd

ABSTRACT Computational Fluid Dynamics (CFD) simulations of a leakage in a pressurized pipe were undertaken to determine the empirical effects of hydraulic and geometric factors on the leakage flow rate. The results showed that pressure, leakage area and leakage form, influenced the leakage flow rate significantly, while pipe thickness and mean velocity did not influence the leakage flow rate. With relation to the interactions, the effect of pressure upon leakage flow rate depends on leakage area, being stronger for great leakage areas; the effects of leakage area and pressure on leakage flow rate is more pronounced for longitudinal leakages than for circular leakages. Finally, our results suggest that the equations that predict leakage flow rate in pressurized pipes may need a revision.

scholarly journals Improving Ceratitis capitata control through the mass trapping technique in an IPM programme on apricots in Tunisia

2021 ◽  
Author(s):  
Mohamed Elimem
Keyword(s):  
Integrated Pest Management ◽  
Pest Management ◽  
Ceratitis Capitata ◽  
Conventional Approach ◽  
Mass Trapping ◽  
Organophosphate Pesticide ◽  
New Techniques ◽  
Damage Rate ◽  
Fruit Damage

New techniques for Ceratitis capitata (Wiedemann, 1824) control are being studied and developed to replace traditional organophosphate pesticide applications. A mass trapping strategy offers promising medfly control within integrated pest management (IPM) programmes. Field assays were performed to study the efficacy of two mass trapping techniques based on PheroNorm<sup>®</sup> and Ceratrap<sup>®</sup> lures that were compared to a conventional approach to control the medfly in Tunisian apricot orchards. The results showed that both mass trapping techniques had a similar efficiency in reducing the C. capitata population. The degrees Brix in the fruits was a determinant issue since the initial apricot fruit damage was detected at 6.4%. At harvesting, the lowest fruit damage rate was recorded in the PheroNorm<sup>®</sup> (4.25%) and Ceratrap<sup>®</sup> (6.50%) treated orchards, compared with the conventional approach (10.75%). Therefore, the use of 50 PheroNorm<sup>®</sup> and Ceratrap<sup>®</sup> traps per ha density within an IPM approach may be very useful to control the C. capitata populations in apricot orchards.

scholarly journals Efficient Escherichia coli (E. coli) Trapping and Retrieval from Bodily Fluids via a Three-Dimensional (3D) Microbeads Stacked Nano-Device

2019 ◽  
Author(s):  
Xinye Chen ◽  
Abbi miller ◽  
Shengting Cao ◽  
Yu Gan ◽  
Jie Zhang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Flow Rate ◽  
Magnetic Beads ◽  
Three Dimensional ◽  
E Coli ◽  
Bodily Fluids ◽  
3D Space ◽  
Fluidic Device ◽  
Computational Fluid Dynamics Cfd ◽  
On Chip

<div>A micro- and nano-fluidic device stacked with magnetic beads is developed to efficiently trap, concentrate, and retrieve Escherichia coli (E. coli) from bacteria suspension</div><div>and pig plasma. The small voids between the magnetic beads are used to physically isolate the bacteria in the device. We use computational fluid dynamics (CFD), 3D</div><div>tomography technology, and machine learning to probe and explain the bead stacking in a small 3D space with various flow rates. A combination of beads with different sizes is utilized to achieve a high capture efficiency of ~86% with a flow rate of 50 μL/min. Leveraging the high deformability of this device, the E. coli sample is retrieved from the designated bacteria suspension by applying a higher flow rate, followed by rapid magnetic separation. This unique function is also utilized to concentrate E. coli from the original bacteria suspension. An on-chip concentration</div><div>factor of ~11× is achieved by inputting 1,300 μL of the E. coli sample and then concentrating it in 100 μL buffer.</div><div>Importantly, this multiplexed, miniaturized, inexpensive, and transparent device is easy to fabricate and operate, making it ideal for pathogen separation in both laboratory and pointof- care (POC) settings.</div>

scholarly journals Efficient Escherichia coli (E. coli) Trapping and Retrieval from Bodily Fluids via a Three-Dimensional (3D) Microbeads Stacked Nano-Device

2019 ◽  
Author(s):  
Xinye Chen ◽  
Abbi miller ◽  
Shengting Cao ◽  
Yu Gan ◽  
Jie Zhang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Flow Rate ◽  
Magnetic Beads ◽  
Three Dimensional ◽  
E Coli ◽  
Bodily Fluids ◽  
3D Space ◽  
Fluidic Device ◽  
Computational Fluid Dynamics Cfd ◽  
On Chip

<div>A micro- and nano-fluidic device stacked with magnetic beads is developed to efficiently trap, concentrate, and retrieve Escherichia coli (E. coli) from bacteria suspension</div><div>and pig plasma. The small voids between the magnetic beads are used to physically isolate the bacteria in the device. We use computational fluid dynamics (CFD), 3D</div><div>tomography technology, and machine learning to probe and explain the bead stacking in a small 3D space with various flow rates. A combination of beads with different sizes is utilized to achieve a high capture efficiency of ~86% with a flow rate of 50 μL/min. Leveraging the high deformability of this device, the E. coli sample is retrieved from the designated bacteria suspension by applying a higher flow rate, followed by rapid magnetic separation. This unique function is also utilized to concentrate E. coli from the original bacteria suspension. An on-chip concentration</div><div>factor of ~11× is achieved by inputting 1,300 μL of the E. coli sample and then concentrating it in 100 μL buffer.</div><div>Importantly, this multiplexed, miniaturized, inexpensive, and transparent device is easy to fabricate and operate, making it ideal for pathogen separation in both laboratory and pointof- care (POC) settings.</div>

scholarly journals Chassis Design of Tomato Picking Robot in the Greenhouse

2021 ◽  
Vol 2136 (1) ◽  
pp. 012047
Author(s):  
Tao Zhu ◽  
JinHua Xiang
Keyword(s):  
Mechanical System ◽  
Motion Control ◽  
Control Algorithm ◽  
Electrical System ◽  
Damage Rate ◽  
Artificial Fruit ◽  
Fruit Damage ◽  
The Times ◽  
Basic Motion

Abstract At present, the artificial fruit picking cost is high, the fruit damage rate is high, and the efficiency is low, so the greenhouse picking robot emerges as the times’ demand. Therefore, this paper designs a kind of a chassis system of greenhouse picking robots. This paper mainly designed and simulates the chassis mechanical system, electrical system, and basic motion control algorithm from three aspects. Finally, the prototype of the chassis system of the picking robot in the greenhouse is completed and the chassis system is debugged, which proves that it has the characteristics of adaptability to the greenhouse environment, strong universality, and strong expansibility.

Design and Test of a Pineapple Picking End-effector

2019 ◽  
Vol 35 (6) ◽  
pp. 1045-1055
Author(s):  
Xinwu Du ◽  
Xulong Yang ◽  
Jiangtao Ji ◽  
Xin Jin ◽  
Lei Chen
Keyword(s):  
Physical Properties ◽  
Performance Test ◽  
Eastern China ◽  
Static Friction ◽  
Fall Rate ◽  
Compressive Properties ◽  
End Effector ◽  
Plant Damage ◽  
Damage Rate ◽  
Fruit Damage

Abstract. In eastern China, pineapple harvesting is a complicated and sometimes dangerous task, and an effective method to harvest pineapples instead of picking them manually has not been developed. In this article, a pineapple picking end-effector based on the physical properties of pineapples (static friction characteristics and compressive properties) was designed. The fingers of the end-effector were used to capture a pineapple in the form of step-by-step movement to help reduce fruit damage and plant damage during picking. The indexes of the evaluation of the pineapple picking performance (fruit damage rate, plant damage rate, fruit fall rate and average picking time) were established, and the picking test was conducted at a pineapple plantation. The temperature effect was analyzed in the morning (19°C) and at noon (35°C). The temperature had no significant effect on the picking performance. The picking performance test showed that the size of the fruit might be the main cause of fruit damage. Throughout the picking test, the fruit damage rate was 5%, the plant damage rate was 0%, the fruit fall rate was 1.7%, and the average picking time of each fruit was 14.9 s. Keywords: Pineapple, Physical properties, End-effector, Low damage picking.

Numerical Simulation and Experimental Study on Tar Decomposition of Low-Pressure Ejection Type Burner

2015 ◽  
Vol 1092-1093 ◽  
pp. 200-206
Author(s):  
De Fan Qing ◽  
Mao Kui Zhu ◽  
Yang Cheng Luo ◽  
Ya Long Zhang ◽  
Ai Rui Chen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Gas Flow ◽  
Low Pressure ◽  
Orthogonal Test ◽  
Nozzle Diameter ◽  
Design Parameters ◽  
Minor Effect ◽  
Gas Flow Rate ◽  
Tar Cracking

The tar decomposition of low-pressure ejection type burner was researched. The burner used software to simulate and analyse impact of the nozzle diameter d, the gas flow rate V and the distance of the nozzle to the wall L on tar cracking. The orthogonal test were used for design parameters d, V and L, the optimization values of these three parameters were carried out, and experimental method was used for test the numerical simulation results. Numerical simulation and experimental results showed that the greatest impact on tar cracking is the nozzle diameter d, the minor effect is the distance of the nozzle to the wall L and the weakest effect is the gas flow rate V, and when the nozzle diameter d=4 mm, the distance L=18 mm and the gas flow rate V=0.10 m3/h, the tar cracking is the most efficiency.

NUMERICAL ANALYSIS OF AN AXIAL BLOOD PUMP WITH DIFFERENT IMPELLER BLADE HEIGHTS

2012 ◽  
Vol 12 (03) ◽  
pp. 1250045 ◽  
Author(s):  
JIAXING QI ◽  
YANHONG ZHOU ◽  
DONGFANG WANG ◽  
LIANG ZHONG
Keyword(s):  
Shear Stress ◽  
Flow Rate ◽  
Reverse Flow ◽  
Blood Pump ◽  
Shear Stresses ◽  
Cfd Simulations ◽  
Impeller Blade ◽  
Rotating Speed ◽  
Shear Stress Level ◽  
Computational Fluid Dynamics Cfd

Computational fluid dynamics (CFD) simulations of the flow in an axial blood pump with different blade heights (BH150, BH200 and BH250) were performed in the present study. The flow in the pump was assumed as steady and turbulent, and blood was treated as incompressible and Newtonian fluid. The flow rate increased with the rise in blade heights. At the impeller rotating speed of 20,000 rpm and a pressure of 100 mm Hg, the pump produces a flow rate up to 5 L/min in BH200 and BH250 models. The reverse flow and vortices have been identified in the BH150 and BH200 models in the outlet regions, but not for BH250 model. The high shear stress of the flow in the pump mainly occurred at the blade tips. The BH200 model achieved an expected flow rate up to 5 L/min with 90% of the shear stresses less than 500 Pa and the exposure time less than 22 ms, which has the acceptable shear stress level in the literature.

Sign in / Sign up

Export Citation Format

Share Document