Pickup Efficiency Research Articles

Particle motion and flow contribution in a double-row hydraulic harvesting model for deep-sea mining

The double-row hydraulic sluicing model is widely used in deep-sea mining collecting systems. However, there has been limited research focusing on its flow contributions and the relationship with particle motions. In this paper, a double-row hydraulic sluicing collector with high pickup efficiency is designed. The flow characteristics, the mechanics of the flow field, and the movement of particles in the collector are analyzed in detail through numerical calculations and experiments. The flow contributions and the collecting mechanism are clearly highlighted through aspects such as the frequency of pressure fluctuations and flow-induced vortices. The high-speed jet rolls upward after hitting the ground, forming a high-pressure area on the ground. The upwelling in the collection area is generated by the combination of the high-pressure area and the upward rolling of fluid. Regarding the particles, it is observed that particle motion can be divided into two main stages, rapid acceleration, followed by slow deceleration. Some particles may fall back when rising. Additionally, the analysis of fluid forces on the particles indicates that drag force and pressure gradient force have significant influence on particle motion.

Performance study of solar tunnel dryer for medicinal plants

A solar tunnel dryer is a poly house framed structure covered with UV-stabilized polythene sheet, where agricultural and industrial products on large scale could be dried under at least partially controlled environment. A solar tunnel dryer accelerates and improves the drying process, it protects the product from insects and other pests-infestation thereby, reducing the contamination or product loss. As a result, the solar tunnel dryer lowers post-harvest losses compared to traditional sun drying. In this study, Adhatoda vasica and Moringa oleifera leaves were dried using a simple, low-cost solar tunnel drier and then it was compared with the open sun-dried products. The drying efficiency and the pick-up efficiency of the solar tunnel dryer for the drying of medicinal plant leaves was found to be 12.14% and 26.45%, respectively. The total drying cost of Adhatoda vasica and Moringa oleifera leaves was calculated as Rs. 16.26/- and Rs.16.87/- per kg, respectively as compared to the cost of sun drying which was Rs.114.1/- and Rs. 135.68/- per kg, respectively. The payback period of the dryer was found to be 1 year and 20 days.

Research Status of Deep-Sea Polymetallic Nodule Collection Technology

The bottom of the ocean is rich in mineral resources, and deep-sea mining has been a research hotspot in recent years. As a key part of deep-sea mining operation, polymetallic nodule collection technology has been researched in many countries around the world. The distribution of deep-sea polymetallic nodule mining areas and the characteristics of nodules are summarized, which provides a reference for the study of collection technology and the optimization of pick-up device structure. In order to further establish a deep-sea mining collection technology system, the current development status of polymetallic nodule mechanical, mechanical–hydraulic composite and hydraulic collection technologies are summarized, and the analysis shows that hydraulic collection technology has a more promising commercialization prospect. For the hydraulic collection technology, the research progress of suck-up-based collection technology, Coandă-effect-based collection technology, double-row hydraulic collection sluicing technology and other collection technologies are summarized from three aspects: collecting principle, device structure parameter optimization, and sea trial situation, and the key technical problems of hydraulic ore collection are put forward. Through the comparative analysis of the pick-up efficiency, energy consumption, environmental disturbance and other performances of different devices, it is found that the Coandă-effect-based hydraulic collection technology has better comprehensive performance. A structural design evaluation indicator for the collection head of hydraulic collection technology is proposed, and the prospect of further research on hydraulic collection technology is put forward.

生鲜农产品冷链集货车辆路径与货物配载联合优化研究

As a bridge connecting agricultural production and consumption, the circulation of agricultural products has the function of connecting supply and demand, guiding production and promoting consumption. However, the development of rural logistics in China is slow, and most logistics centers still rely on experience to plan the pick-up vehicle routings, resulting in long transport time and high cost. In order to improve the efficiency of pick-up and reduce transportation costs, a joint optimization model of cold-chain pick-up vehicle routing and cargo allocation for fresh agricultural products was proposed in this study. Soft time window constraint and three-dimensional loading constraints were considered, and the lowest pick-up cost was used as optimization goals in this model. In addition, adaptive large neighborhood search algorithm (ALNS) and heuristic depth-first search algorithm (HDFS) were combined to solve the model. A case study of Kunming International Flower Auction Center was conducted to compare the schemes of pick-up vehicle routing before and after optimization. Results demonstrate that the pick-up cost after optimization decreases by 9.6 %, the number of vehicles decreases by one, the total volume utilization rate of vehicles increases by 23 %, and the total load utilization rate of vehicles increases by 15 %. This study provides a model reference and solution method for enterprise operators to formulate schemes of pick-up vehicle routing quickly and reasonably.

Simulation and experimental study of die-casting pickup robot

To improve the efficiency of die-casting machine pickup, the combination of SolidWorks and RobotStudio is proposed to establish a simulation workstation. In this paper, the key mechanism analysis and design of the die-casting machine pickup robot are used to determine the robot body and end-effector. SolidWorks three-dimensional software is used for die-casting pickup robot’s overall mechanical structure and workstation peripheral equipment modeling. The RobotStudio software is used for the corresponding model planning layout and Smart components to write to achieve die-casting robot workstation efficient pickup work program writing and simulation debugging. Experimental results show that the die-casting machine pickup robot completed the pickup behavior. The system has the advantages of fast response speed, high positioning accuracy, and reliable operation, effectively improving the efficiency of the production line.

Comparative Performance Evaluation of PVT Assisted Dryer And Conventional Solar Thermal Dryer In Drying of Tomatoes (Lycopersicon Esculentum)

Drying is an essential post-harvest preservation method for agricultural produce. Since drying is an energy absorbing process, farmers need to have access to effective dying techniques in order to maintain the quality of the products and maximize their profit. Hence, A Solar hybrid (PV/T) assisted dryer was designed, constructed and evaluated for drying of Tomatoes (Lycopersicon Esculentum). The load test drying efficiency of Solar Hybrid (PV/T) dryer was compared to Conventional Solar Thermal Dryer. The daily average moisture content reduction of tomatoes was 0.47g±0.169 while Solar thermal showed average reduction of 0.437g±0.188 for 35 and 37 hours respectively. The result of- t-test revealed there was no significant difference in the daily average drying rate between the hybrid (PV/T) and Solar thermal dryer. The results from the three models indicated moisture content reduction on daily basis shows that polynomial model has the highest (R²=0.9937, R²=0.9975) value and this implies that the average daily moisture content reduction of tomatoes for hybrid (PV/T) and solar thermal dryer were best described by polynomial model. The result of the proximate analysis conducted for the dried tomatoes sample using (PV/T) hybrid dryer and Solar thermal dryer indicated that ash content (5.3%), moisture content (13.31%), lipid (0.87), protein (8.87%), fiber (5.48%) `was significantly lower in sample dried with solar thermal dryer, while the lipid content (0.64%) and available carbohydrates (62.3%) are lower in tomato dried with Solar thermal dryer. The mycology test conducted for the fresh and dried tomatoes samples revealed the presence of the following fungi; S. cireviceae, S. Pombe, F. oxyspurum and F. solani with highest frequency of occurrence of S. solani (28%) and S. Pombe with lowest (3.96%) respectively. The collection efficiency of the dryer on drying of 4kg tomato sample was 42.49 %, pickup efficiency 36.89% and System efficiency 5.63%. The result obtained showed that PVT hybrid dryer is better option for drying compared to solar thermal dryer.

Progesterone Device Use Improves Ovum Pick-Up Efficiency in Acyclic Donors

The aim of this study was to evaluate follicular dynamics and ovum pick-up (OPU) efficacy in untreated mares or mares treated with an intravaginal progesterone (P4) device during seasonal anestrus (acyclic) and during the breeding season (cyclic). Six mares (mean age = 5 years), were recruited into an ovum pick-up scheme that was performed every 14 days with and without the P4 device, during the acyclic and cyclic phases. Aspirations amounted to seven procedures with or without the P4 device during each phase. Five ultrasound assessments were performed at each interval between the OPUs. Data on follicular number and diameter as well as the numbers of recovered and the percentage of recovered oocytes were also collected. The number of follicles from mares in the acyclic phase was higher (P < .005) regardless of the treatment. However, the follicular diameter was smaller for the P4 group (P < .005) from the 2nd to the 5th evaluation post-OPU procedure. The percentage of oocytes recovered during the acyclic phase was higher for mares treated with the P4 device (P < .005). The P4 device resulted in follicles with smaller diameters and facilitated OPU efficacy.

Experimental and numerical study of a conceptual nodule pick-up device with spiral flow generator

The nodule pick-up device is an indispensable component in deep-sea mining systems. To achieve high pick-up efficiency and low environmental disturbance during the collection process, a conceptual sucker-shaped nodule pick-up device is proposed by incorporating the spiral flow generator with four jet nozzles, featuring a jet start-spin mechanism. The performance, flow-field characteristics, and ambient disturbance were comprehensively examined under three swirling intensities through experiments and numerical simulations. The results showed that the device with tangential jet involvement can enhance the pick-up efficiency by approximately 12.8% in comparison with the suction-only mode. The augmentation in the swirling intensity leads to a transition in the nodule trajectory from a state of disarray to a well-defined circular motion owing to the disparate pressures encompassing the nodule. As the swirling intensity increases, the flow field with a vertical-axis vortex materializes into the vertical pressure disparity. Furthermore, the sea-bed deposits become more concentrated within the pick-up device (r/(D/2) < 0.5), withholding the tendency to disturb adjacent areas. These results will improve the understanding of the physics of nodule collection flows and help develop more efficient and environmentally friendly techniques for deep-sea mining.

A prediction-based iterative Kuhn-Munkres approach for service vehicle reallocation in ride-hailing

ABSTRACT Online ride-hailing services provide additional transportation capability by recruiting private vehicles to meet people’s growing travel demand. To ensure the profitability of drivers and platforms, pick-up efficiency and frequency must be maintained at high levels. Therefore, consistency between the spatial distribution of drivers and that of travel demand becomes a key issue to address. This paper proposes a prediction-based iterative Kuhn-Munkres approach for service vehicle reallocation in the context of large-scale online ride-hailing. Firstly, preliminaries are formally defined and a novel mathematical model for the problem is proposed. Secondly, a deep spatio-temporal residual perception network is designed to accurately predict travel demand. Thirdly, an iterative Kuhn-Munkres approach combined with an improved A-Star algorithm is developed to reallocate service vehicles to spatial locations according to their distinct travel demand densities. Finally, extensive experiments are conducted to evaluate and verify the performance of the proposed approach.

自走式红枣集条捡拾机的设计与试验

Aiming at the problems of single mechanical performance, multi-person operation and low operation efficiency of air-suction jujube harvesting in China, combined with the requirements of mechanized jujube harvesting in Xinjiang, this study designed a self-propelled jujube collection strip pick-up machine. The machine is mainly composed of crawler chassis, landing jujube collection strip device, separation and impurity removal device and hydraulic system. According to the jujube planting mode, the size of the crawler chassis is 1780 mm × 1650 mm × 310 mm. In order to simulate the effect of artificial collecting strips, a reciprocating collecting strip blowing head was designed with a height of 15 cm from the ground, a horizontal and vertical angle of 35° and 15° respectively. The model of the collecting fan is selected as 9-19-4A; the fluid simulation analysis of the separation and impurity removal box is carried out to verify the rationality of the box structure design. The performance of the picker was tested by pick-up efficiency, cleanliness, breakage, and impurity rates. The results show that when the forward velocity was about 0.40 m·s-1 , the average pick-up efficiency could reach 752.7 km·h-1 , the average pick-up cleanliness rate was 95.66 %, the average breakage rate was 2.68 %, and the average impurity rate was 3.64 %. The self-propelled jujube collection strip pick-up machine designed in this experiment meets the requirements of mechanized harvesting of jujube and can realize single-person remote control operation.

Vitrification and direct warming in iso-osmotic holding medium of equine in vitro embryos supports competitive pregnancy rates

Improved efficiency of ovum pick-up (OPU) and intracytoplasmic sperm injection (ICSI) resulted to a steep increase in the number of in vitro produced (IVP) equine embryos worldwide. These IVP blastocysts are routinely cryopreserved and both slow freezing and vitrification result in high pregnancy rates. The use of minimal volume cryodevices and fast, multistep warming protocols can be challenging for veterinary practitioners receiving vitrified embryos, but direct warming in embryo holding medium supports embryo viability (Canesin et al. Theriogenology. 2020;151:151-158). The aim of this study was to compare pregnancy rates in a clinical OPU-ICSI program using a three-step vitrification/warming protocol vs. a commercial vitrification kit and direct warming in embryo holding medium. Embryos were produced in autumn and winter of 2021-2022 by OPU-ICSI (Papas et al. Animals. 2021;11:2004). Day of vitrification (7-12 post ICSI) was similar for both vitrification groups. Blastocysts were vitrified in a minimal volume on a Cryolock (Irvine Scientific) following two methods: (1) a three-step protocol (n=21): holding in basal vitrification medium (BVM; DMEM-F12 with 20% FCS), vitrification in BVM with 1.5M ethylene glycol (5 min), followed by BVM with 7M ethylene glycol and 0.6M galactose (40 s), and warming in warming medium (WM; DPBS with 0.1% glucose,36 mg/L pyruvate, and 0.4% BSA) with 0.3M sucrose (1 min), followed by WM with 0.15M sucrose (5 min) and holding in WM (5 min), all performed at 38.2°C (Choi and Hinrichs. Theriogenology. 2017; 87:48-54); (2) direct warming (n=21): vitrification at 23°C with a commercial VIT-Kit (Minitube, Germany) in VS1 (5 min), VS2 (5 min) and VS3 (40 s), containing increasing concentrations of glycerol and/or ethylene glycol, based on Eldridge-Panuska et al. (Theriogenology. 2005; 63:1308-1319), and direct warming at 38°C for 5 min in 4 ml of Emcare holding medium (Spervital, The Netherlands). For both protocols, warmed embryos were washed four times in Emcare and transferred immediately to a day 4 recipient mare. The effect of vitrification method on pregnancy rate at 14 days and 25 days was determined using binomial logistic regression analyses. Pregnancy rates at 14 and 25 days were respectively 66.7% and 47.6% for the three-step method and 76.2% and 52.4% for the direct warming. No difference was found between the two methods (p=0.496 and p=0.882, respectively). In conclusion, vitrification and warming of IVP blastocysts using commercial media and direct warming supports pregnancy and provides an easy method for embryo warming and transfer by equine veterinary practitioners.

A Robot Path Planning Method Based on Improved Genetic Algorithm and Improved Dynamic Window Approach

Intelligent mobile robots play an important role in the green and efficient operation of warehouses and have a significant impact on the natural environment and the economy. Path planning technology is one of the key technologies to achieve intelligent mobile robots. In order to improve the pickup efficiency and to reduce the resource waste and carbon emissions in logistics, we investigate the robot path optimization problem. Under the guidance of the sustainable development theory, we aim to achieve the goal of environmental social governance by shortening and smoothing robot paths. To improve the robot’s ability to avoid dynamic obstacles and to quickly solve shorter and smoother robot paths, we propose a fusion algorithm based on the improved genetic algorithm and the dynamic window approach. By doing so, we can improve the efficiency of warehouse operations and reduce logistics costs, whilst also contributing to the realization of a green supply chain. In this paper, we implement an improved fusion algorithm for mobile robot path planning and illustrate the superiority of our algorithm through comparative experiments. The authors’ findings and conclusions emphasize the importance of using advanced algorithms to optimize robot paths and suggest potential avenues for future research.

Mining of deep-seabed nodules using a Coandă-effect-based collector

We present an effective design of a hydraulic, polymetallic nodule collector, which fundamentally depends on the Coandă effect in harvesting nodules. The design was first developed based on 2D numerical simulations conducted using a computational fluid dynamics tool, ANSYS FLUENT. Following that, the design was tested in full-scale experiments, which provided insights into the collection efficiency of the collector and confirmed its functionality and effectiveness. The latter means, in the context of deep sea mining, high effective pick-up of nodules, with minimum sediment disturbance. Our observations indicate that our design hardly disturbs the tested sediment bed. The experimental results show that a higher jet velocity leads to a higher pick-up efficiency. Two forward velocities were tested and the higher forward velocity led to a lower pick-up efficiency. It is revealed that the available time for the nodules to respond to the pressure gradient under the collector is of great importance; if the available time is not sufficient, the nodules will not be picked-up even if the pressure gradient is adequate. The clearance under the rear cowl of the collection duct is found to play a major influential role in the collection process; a smaller bottom clearance results in a higher pick-up efficiency.

Nondominated Sorting Differential Evolution Algorithm to Solve the Biobjective Multi-AGV Routing Problem in Hazardous Chemicals Warehouse

For the multiple automated guided vehicle (multi-AGV) routing problems in the warehousing link of logistics, where the optimization objective is to minimize both the number of AGVs used and the maximum pickup time simultaneously, a nondominant sorting differential evolution (NSDE) algorithm is proposed. In the encoding and decoding stages, the pickup point area is divided. AGVs are allocated to each region according to the proposed rule based on avoiding duplicate paths. Meanwhile, the pickup points within the region can be adjusted to optimize the pickup paths and improve the pickup efficiency. The fast nondominated sorting method and elitist selection strategy in the nondominated sorting genetic algorithm II (NSGA-II) are introduced into the differential evolution algorithm, which sorts all the regions to obtain the best Pareto solution set. Lastly, the domination of the proposed NSDE algorithm in Pareto frontier evaluation indicators is verified by some numerical experiments.

Investigation of Dual–Pass Inclined Oscillating Bed Solar Dryer for Drying of Non-Parboiled Paddy Grains

This Paper determines an experimental study of dual-pass solar dryer with a bed tilt of 0.5° and varying oscillating frequency of drying chamber namely 1.25, 1.75 and 2.25 Hz for drying an agricultural produce namely non–parboiled paddy grains. The oscillations and bed tilt are provided to move the grains from entry to exit of the top bed and moving down to bottom bed and finally exits from the dryer. The new technology has been used in the solar dryer for drying of agricultural produce such as non–parboiled paddy grains to increase the quality and to decrease the loss of the dried produce. The present dryer model was used for drying 45 kg of non–parboiled paddy grains from 19% (w.b) to the approved range of 12–14% of moisture content obtained in a single experimental day. The dried paddy grains obtained an average moisture content are 13.03, 13.22 and 13.51% at the frequency of oscillation of 1.25, 1.75, 2.25 Hz, respectively. The maximum thermal and pick-up efficiency of the model were obtained at 1.00 p.m. in all cases. For the frequency of oscillation of 1.25, 1.75 and 2.25 Hz, the maximum dryer thermal efficiency was 44.47, 43.39 and 41.39%, respectively, and the maximum pick–up efficiency was 80.41, 79.19 and 76.21%, respectively. The optimum drying performance was obtained at the oscillating frequency of 1.75 Hz with the bed tilt of 0.5°.

Dilution of Epidemic Potential of Environmentally Transmitted Infectious Diseases for Species with Partially Overlapping Habitats.

AbstractSpecies diversity may play an important role in the modulation of pathogen transmission through the dilution effect. Infectious disease models can help elucidate mechanisms that may underlie this effect. While many modeling studies have assumed direct host-to-host transmission, many pathogens are transmitted through the environment. We present a mathematical modeling analysis exploring conditions under which we observe the dilution effect in systems with environmental transmission where host species interact through fully or partially overlapping habitats. We measure the strength of the dilution effect by the relative decrease in the basic reproduction number of two-species assemblages compared with that of a focal host species. We find that a dilution effect is most likely when the pathogen is environmentally persistent (frequency-dependent-like transmission). The magnitude of this effect is strongest when the species with the greater epidemic potential is relatively slow to pick up pathogens in the environment (density-dependent transmission) and the species with the lesser epidemic potential is efficient at picking up pathogens (frequency-dependent transmission). These findings suggest that measurable factors, including pathogen persistence and the host's relative efficiency of pathogen pickup, can guide predictions of when biodiversity might lead to a dilution effect and may thus give concrete direction to future ecological work.

Intelligent face recognition system based on OpenMV

With the rapid development of e-commerce in Internet technology, online shopping has become the mainstream shopping method accepted and favored by people. E-commerce and online shopping not only bring convenience to people’s life, but also aggravate the surge of express delivery. In order to improve the pick-up efficiency, this paper designs an intelligent pick-up express system based on OpenMV face recognition. The system takes STM32 single chip microcomputer as the core controller, and reads and transmits express information based on OpenMV face recognition; The trolley tracks and avoids obstacles independently, and takes parts according to the planned path of the system. Experiments show that the system can realize express automatic pick-up, and has a broad application prospect.

Performance studies on mixed-mode forced convection solar cabinet dryer under different air mass flow rates for drying of cluster fig

A Mixed-mode Forced Convection Solar Cabinet Dryer (MFCSCD) is designed for the maximum harnessing of solar radiation. It utilizes the direct heat from solar radiation through glass cover as well as preheated air from two solar air heaters (SAHs) fixed in series having a double pass. The experimental research works were performed in the metrological conditions of Guwahati, India. The drying performance of MFCSCD was analyzed under different air mass flow rates in terms of specific moisture extraction rate (SMER), pickup efficiency, and dryer efficiency for the drying of cluster fig. Further, a thin layer drying kinetics analysis was carried out to find the best suited mathematical model for representing the drying behavior of cluster fig in MFCSCD and open sun drying. Cluster fig dried from moisture content (MC) of 5.67 to 0.08 kg/kg on a dry basis in 7.0, 8.0, 8.5, and 9.5 h at airflow rates of 3.72, 2.76, 1.8, and 1.08 kg/min, respectively, whereas it took 14 h to attain the same moisture level under open sun drying. The experimental results showed higher dryer and pickup efficiencies and SMER at 3.72 kg/min air flow rate. The quality analyses of solar and sun-dried were carried out to estimate the total phenolic content, antioxidant activity, and rehydration ratio.

Comparative Study on Collection Performance of Three Nodule Collection Methods in Seawater and Sediment-seawater Mixture

In this paper, three kinds of polymetallic nodule hydraulic collection methods: suck-up-based method, Coandă-effect-based method, and double-row hydraulic sluicing method are investigated. Nodule collection performances among them are compared from two aspects: pick-up efficiency η and flow field disturbance near the seabed. Influences of flow discharge Q and towing speed V on η are numerically investigated for three nodule pick-up device models based on the three methods. The numerical method's application in simulating the collection flow field and nodule trajectories is validated by comparing the numerical results with experimental results. Collection flow fields are revealed to deepen understanding of the mechanism of hydraulic collection. Furthermore, distributions of the turbulent kinetic energy k and diffusions of the sediment-seawater mixture are simulated to assess the flow field disturbance. The results indicate that the suck-up-based method has the least flow field disturbance and the largest Q for achieving the same η among the three methods. The Coandă-effect-based method shows good performance in both η and small flow field disturbance. The double-row hydraulic sluicing method shows a significant advantage in η but disturbs the seabed greatly. Finally, a qualitative evaluation of collection performances for the three methods is proposed.

Comparative performance of a solar assisted heat pump dryer with a heat pump dryer for Curcuma

&lt;p&gt;This study evaluated the performances of solar assisted heat pump dryer (SAHPD) and heat pump dryer (HPD) for drying of &lt;em&gt;Curcuma xanthorrhiza Roxb&lt;/em&gt;. The HPD and SAHPD reduced mass of &lt;em&gt;Curcuma&lt;/em&gt; from 30.70 kg to 7.85 kg needed 10.5 hours and 8 hours with average temperature and relative humidity 49.2oC and 26.5%, and 57.7oC and 19.8%, for SD and SAHPD respectively. The moisture of Curcuma dried from 3.167 db to 0.065 db with an air mass flow rate of 0.121 kg/s. The SAHPD reduced the drying time about 24% compared to HPD. The drying rate and the specific energy consumption were calculated in an average 1.05 kg/h and 1.36kg/h, and 1.17kWh/kg and 2.07kWh/kg for HPD and SAHPD, respectively. The specific moisture extraction rate and the dryer thermal efficiency were calculated in an average 0.931 kg/kWh and 0.521 kg/kWh, and 61.0% and 34.3% for HPD and SAHPD, respectively. Whereas, the pickup efficiency and the coefficient of performance of the heat pump were calculated in an average 57.5% and 59.2%, and 4.03and 4.35 for HPD and SAHPD, respectively. The SAHPD is capable of drying &lt;em&gt;Curcuma&lt;/em&gt; quickly because of the high pickup efficiency and high drying rate.&lt;/p&gt;