Optimal Working Parameters Research Articles

Design and Experiment of Stubble Chopping and Scattering Device Based on 2BMFJ-12 No-tillage Precision Planter

HighlightsA stubble chopping and scattering device based on 2BMFJ-12 no-tillage precision planter was modelled and developed.The optimal working parameters were obtained through theoretical analysis, flow field simulation, field test, and optimization combination test,The device improves the straw chopping and scattering ability of no-tillage planter.Technical support is provided for the development of conservation tillage equipment.Abstract.Aiming at the problems of poor stubble chopping quality of 2BMFJ-12 no-tillage precision planter, leading to slow stubble degradation rate, inconsistent seedlings emergence, and partial surface exposure, affecting tillage and crop yield at seedling stage, the stubble chopping and dispersal device was designed. The theoretical analysis of the corn stubble picking and chopping processes was carried out. The flow field characteristics in the volute were simulated by SolidWorks Flow Simulation. The main parameters and value range affecting the working performance of the device were determined. The orthogonal experiment method of three factors and three levels was used to carry out the field experiment with the angle of broken cutter, the rotation speed of cutter shaft and the inclination angle of negative pressure blade as the experiment factors, and the qualified broken rate, the uneven coverage, the scattering distance and the power consumption as the evaluation indexes. The variance analysis and optimization of the experiment results were carried out by Design-Expert 6.0.10. The optimized combination of parameters is that when the inclination angle of the chopping knife is -10.5°, the rotational speed of the knife shaft is 1120 r·min-1, and the inclination angle of the negative pressure blade is -15°, the qualified rate of chopping is greater than 93.01%, the coverage unevenness is less than 17.11%, the scattering distance is greater than 6.80 m, and the power consumption is less than 6.79 kW. The research results provide technical support for 2BMFJ no-tillage precision planter to improve stubble chopping and covering quality. Keywords: Corn stubble, No-tillage sowing, Scattering distance, Stubble broken, Uniform coverage.

Design and Testing of a Shearing and Breaking Device for Mulch Film and Cotton Stalk Mixtures

HighlightsThis article presents a shearing and breaking device for mulch film and stalk mixtures after mechanized recovery.The focus is on a curved V-shaped mechanism with three-dimensional precompression and shearing functions.The device can efficiently and continuously perform film crushing, stalk crushing, and entanglement breaking.The crushed film and stalk mixture is conducive to material separation, further treatment, and recycling.Abstract. Because the mixture of mulch film and stalks collected in harvested cotton fields in Xinjiang, China, cannot be separated mechanically, a technical solution for shearing and breaking is proposed. This study designed a shearing and breaking device for film and stalk mixtures that can continuously perform film crushing, stalk crushing, and entanglement breaking. The design focuses on a curved V-shaped shearing mechanism, which provides three-dimensional shearing and improves the crushing of film and stalks. The linear speed of the conveying rollers (x1), the working angle of the shearer (x2), and the speed of the shearer spindle (x3) were selected as influencing factors, and the crushed film rate (Ph), crushed stalk rate (Gh), and broken entanglement rate (Kh) were used as evaluation indexes in quadratic orthogonal rotation combination tests. The test results were analyzed with Design-Expert software, and a regression model between each factor and the evaluation indexes was established to analyze the significance of each factor’s influence. The results showed that the influences of the three factors on Ph in descending order were x3, x2, and x1. The order of influence on Gh and Kh was x3, x1, and x2. The optimization module in the software was used for parameter optimization, and the optimal combination of working parameters of the device was x1 = 0.98 m s-1, x2 = 153°, and x3 = 753 r min-1. The optimized parameter combination was tested and verified, and the results were Ph = 77.28%, Gh = 87.78%, and Kh = 85.30%. The test results are basically consistent with the predicted values, and the optimized working parameters are reliable and can meet the requirements for the shear fracture of film and stalk mixtures. This research provides a technical reference for the cutting and crushing of complex mixed solid materials. Keywords: Agricultural machinery, Curved V-shaped moving knife, Design, Film and stalk mixture, Parameter optimization.

Experiment and Optimization of High-Efficiency Mechanical Separation of Peanut Seedlings and Residual Film Based on Suspension Velocity

HighlightsAn efficient method for separating peanut seedlings and residual film harvested from film-mulched peanut was proposed, and the mechanism was optimized.The relationships between the suspension velocity and moisture content of different shredded materials were studied.Four-factor, three-level Box-Behnken experiments were carried out and analyzed, and the optimal parameter combination was determined.A validation test was carried out to verify the rationality and accuracy of the optimized regression model.Abstract. To address the problems of lower residual film removal and higher material loss in the forage utilization of peanut seedlings wrapped in residual film, this study explored the relationships between the suspension velocity and moisture content of different shredded materials derived from peanut seedlings and conducted performance tests and parameter optimization for a machine that uses peanut seedlings as forage material. Four-factor, three-level Box-Behnken experiments were designed using the rotational speeds of the shredding shaft, upper fans, and lower fans and the frequency of the vibrating sieve as test factors, and using the residual film removal rate and material loss rate as response values. The test results indicated that the suspension velocity of the shredded materials showed a quadratic relationship with moisture content. The performance tests showed that the significance sequence of the test factors for the residual film removal rate was: rotational speed of the lower fans, rotational speed of the upper fans, rotational speed of the shredding shaft, and frequency of the vibrating sieve. The significance sequence for the material loss rate was: rotational speed of the lower fans, rotational speed of the shredding shaft, frequency of the vibrating sieve, and rotational speed of the upper fans. The parameter optimization and validation test showed that the residual film removal rate was 92.71% and the material loss rate was 8.19% when the rotational speeds of the shredding shaft, upper fans, and lower fans were 1650, 770, and 665 rpm, respectively, and the frequency of the vibrating sieve was 4 Hz. The relative errors between the validation test results and the predicted values from the regression models were less than 3%, which suggests that the regression models are reliable. This study provides a reference for the forage utilization of peanut seedlings harvested from film-mulched peanut and provides a reference for determining the optimal working parameters of forage processing machines. Keywords: Agricultural machinery, Box-Behnken experiment, Optimization, Peanut film-seedling separation, Suspension velocity.

Design and Evaluation of the Key Units in a Rapeseed Direct Seeder Integrated with Plowing-Rotating Combined Tillage

HighlightsThe seeder combined the plowing and rotating tillage to overcome the heavy soil and a large amount of straws.The plow could lift and turn the soil and straw before rotary tillage.The optimal working parameters of the seeder were obtained by orthogonal field experiments.Abstract. Rapeseed, one of the most important oil crops in China, is mainly planted in the mid-lower reaches of the Yangtze River. However, limited by the special long-term rice-rapeseed rotation, rotary tillage is applied in most of the planted areas apply instead of plow tillage, leading to a shallow arable layer. On the other hand, maintaining a high-quality seedbed for rapeseed becomes a challenge because a large amount of straw remains buried in the soil. As a solution, a rapeseed direct seeder that combines plow tillage and rotary tillage was designed. The structure of the plowing unit, whose key components were a lifting-turning plow and symmetrical plow, was analyzed based on the forming principle of the plow. Furthermore, a mechanical soil throwing model of the rotary tillage blade was built to determine the structural parameters. Then, the interaction between the rotary tillage unit and the lift-turning plow was analyzed. Finally, the performance and optimal parameters were evaluated by orthogonal field experiments. The seedbed after the operations indicated that the seeder could achieve the function of turning the soil and straw first and then rotating the soil with good passability, mixing the straw and the soil, flattening the surface of the seed bed, and stabilizing the tillage depth. Orthogonal experiments showed that the optimal working parameters of the seeder were as follows: the tillage depth was 180 mm, the equipment forward speed was 2.1 km/h, and the speed of the rotary tillage blade was 250 r/min. Under the optimal parameter combination, the power consumption of the seeder, the thickness of the tillage layer, the crop residue burial efficiency, the soil breakage efficiency, and the flatness of the seed bed surface were 30.48 kW, 231 mm, 90.88%, 93.26%, and 21.15 mm, respectively. The working performance of the seeder could meet the tillage requirements of rapeseed planting. Keywords: Direct seeder, Evaluation, Plow, Plowing-rotating combined tillage, Rapeseed.

Numerical simulation and analysis of mechanized suppression process of seedbed with whole plastic film mulching on double ridges

In order to achieve the construction standard of high mechanized performance of the seedbed with whole plastic-film mulching on double ridges, in this study, the forms of suppression failure were analyzed, and the key factors influencing the suppression performance were determined based on the structure of the seedbed suppression device and its working principles. The discrete element method was adopted for numerical simulation on the suppression process of the seedbed with whole plastic film mulching on double ridges; the parameters during the interaction between the suppression device and seedbed soil were extracted and analyzed, such as contact area, sinkage and horizontal traction resistance trend of press wheels on big ridges and furrows of small ridge. Taking the suppression load on big ridges, suppression load on furrows of small ridge, and advancing velocity of the combined operation machine as the independent variables, qualified rate of suppression as the response value, a mathematical model between the test factors and qualified rate of suppression was established, to explore the influence sequence of the factors on suppression qualified rate. The optimal working parameters of the suppression device were finally obtained: the suppression load on big ridges was 40 N, suppression load on furrows of small ridge was 69.8 N and the machine advancing velocity was 0.98 m/s, and the achieved mean value of suppression qualified rate was 92.6%. Field verification test showed that the mean value of suppression qualified rate was 90.3%, a mere difference of 2.3% compared with the simulation result. The actual operation of the sample machine was basically consistent with the simulation process and could reveal the mechanized suppression operation mechanism of the seedbed with whole plastic film mulching on double ridges, indicating that the established DEM model and its parameter setting were relatively accurate and reasonable. Keywords: seedbed, whole plastic film mulching, double ridges, mechanized suppression, discrete element method, numerical simulation, parameter optimization DOI: 10.25165/j.ijabe.20211401.5866 Citation: Dai F, Song X F, Zhao W Y, Sun B G, Shi R J, Zhang Y. Numerical simulation and analysis of mechanized suppression process of seedbed with whole plastic film mulching on double ridges. Int J Agric & Biol Eng, 2021; 14(1): 142–150.

Подбор рабочих параметров для проведения направленного протеолиза казеина с целью получения биопептидов

Introduction. Public health is gradually deteriorating as a result of unhealthy lifestyle and diet, which triggers allergic reaction to certain foods. Milk and dairy products are rich in biologically active substances, which makes them a good dietary supplement for athletes, diabetic patients, etc. However, this popular food contains allergens, for instance, such proteins as αS1-casein, αS2-casein, β-casein, and κ-casein. Therefore, one of the most urgent tasks of modern food science is to reduce the allergenic properties of casein. Heat treatment is an option, but thermal exposure leads to denaturation and produces new antigenic determinants, e.g. epitopes.
 Biotechnological processing is a more promising method. It is based on the catalytic properties of proteolytic enzymes. Enzymes make it possible to obtain a protein hydrolyzate with amino acids of various molecular weights. The present research provided the optimal working parameters of casein proteolysis by various enzymes (endopectidases), namely trypsin, chymotrypsin, and thermolysin.
 Study objects and methods. Casein hydrolysates are casein-based biopeptides, and casein is an accessible and valuable milk protein. Trypsin, chymotrypsin, and thermolysin were used as proteases. The experiment was based on standard methods. Results and its discussion. At 47 ± 2°C and pH 7.5 ± 0.2, the production of low-molecular-weight components of casein hydrolyzate proved feasible when thermolysin was used at a ratio of 1:100 for 24.00 ± 0.05 h, and chymotrypsin and trypsin – at a ratio of 1:25 for 24.00 ± 0.05 h.
 Conclusion. The resulting casein hydrolysates contain biologically active peptides and can be used in formulations of low-allergy functional dairy products in allergy-friendly, sports, and baby diets.

Improved autonomous error correction using variable dissipation in small logical qubit architectures

Coherence times for superconducting qubits have greatly improved over time. Moreover, small logical qubit architectures using engineered dissipation have shown great promise for further improvements in the coherence of a logical qubit manifold comprised of few physical qubits. Nevertheless, optimal working parameters for small logical qubits are generally not well understood. This work presents several approaches to finding preferential parameter configurations by looking at three different cases of increasing complexity. We begin by looking at state stabilization of a single qubit using dissipation via coupling to a lossy object. We look at the limiting factors in this approach to error correction, and how we address those by numerically optimizing the parametric coupling strength with the lossy object having an effective time-varying dissipation rate—we call this a pulse-reset cycle. We then translate this approach to more efficient state stabilization to an abstracted three-qubit flip code, and end by looking at the very small logical qubit (VSLQ). By using these techniques, we can further increase logical state lifetimes for different architectures. We show significant advantages in using a pulse-reset cycle over numerically optimized, fixed parameter spaces.

Mechanism analysis and performance improvement of mechanized ridge forming of whole plastic film mulched double ridges

In order to achieve high-performance and mechanization construction standard of whole plastic mulched double ridge seedbed, and to meet its forming process and corresponding agronomic requirements of the mechanized double ridge seedbed, the key working parameters such as the speed of rotary blade group, the thickness of upturned sod and the power consumption of rotary blade group under different parameters were analyzed based on related working performance in ridge forming. Also, the test factors and their range of values were finally determined in this study. Discrete element method (DEM) simulation was applied in the numerical simulation of the mechanized ridge forming process of whole plastic mulched double ridges, and the ridge forming effect and digging resistance variation characteristics of different types of shovels were compared. Taking the forward speed of the combined machine, the penetration angle of the arc-shaped shovel and the depth of rotary tillage as independent variables, and the qualified rate of seedbed tillage as the response value, the mathematical model between the test factors and the qualified rate of the seedbed tillage was established, to explore the influence sequence of the factors on the qualified rate of seedbed tillage, and obtained the following optimal working parameters of the ridge forming device: the advancing velocity of the combined machine of 0.50 m/s, penetration angle of the arc-shaped shovel of 31°, rotary tillage depth of 140 mm, and average qualified rate 95.20% of seedbed tillage in corresponding simulation verification test. Field test showed that the average qualified rate of seedbed tillage in ridge forming device was 93.60%, which was close to that of the simulation results. The actual working condition of the sample machine was basically in line with the simulation process and could relatively precisely reflect the mechanized ridge forming mechanism of whole plastic double ridges. The results showed that the established DEM model and its parameter setting were relatively accurate and reasonable. Keywords: whole plastic film mulched double ridges, mechanized ridge forming, DEM, numerical simulation, parameter optimization DOI: 10.25165/j.ijabe.20201305.5747 Citation: Dai F, Song X F, Zhao W Y, Shi R J, Zhang F W, Zhang X K. Mechanism analysis and performance improvement of mechanized ridge forming of whole plastic film mulched double ridges. Int J Agric & Biol Eng, 2020; 13(5): 107–116.

Pilot scale supercritical CO2 extraction of carotenoids from sweet paprika (Capsicum annuum L.): Influence of particle size and moisture content of plant material

The extraction of important phytochemicals such as carotenoids from sweet paprika using supercritical carbon dioxide (SC–CO2) was discussed in this paper. The effect of particle size, moisture content, and composition of raw material on extraction efficiency, the content of carotenoid in the paprika extract and recovery of carotenoid were demonstrated. Results of SC-CO2 extraction were compared to extraction using n-hexane. It was observed that increasing lipid content and reducing particle size led to an increase in extraction efficiency and also the increase in carotenoids recovery. The moisture content of paprika below 7.5 g/100 g did not have an effect on process efficiency and carotenoid extraction. However, higher content of water in paprika has an impact on the decrease of carotenoid recovery, and it necessitated the additional separation of water from the paprika extract. The optimal working parameters with respect to the extract yield and recovery of carotenoid was the extraction of paprika with the moisture content of 7.5 g/100 g and particle size of <0.2 mm using SC-CO2 at 45 MPa and 50 °C.

Multi-Objective Optimization of Biodiesel and Diethyl Ether Doped Diesel Engine by Taguchi Method

In present study, it was targeted to optimize multiple impacts of palm oil ratio, diethyl ether (DEE) percentage and engine load on the performance and emissions of a single cylinder diesel engine. The experiments were de-signed on the basis of the Taguchi L27 orthogonal array, which accepts palm oil percentage, DEE ratio and load as variables, brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), nitrogen oxide (NOx) emis-sion and smoke emission as responses. The impacts of engine running factors on responses were defined by analysis of variance (ANOVA). S / N ratio and interactions plots were created for each answer to show optimum factor lev-els. The results showed that the most effective parameters in general on all engine outputs are the load and DEE ratio. In addition, considering the find-ings obtained, the best working variables of the engine were determined as 5% DEE percentage, 6% palm oil percentage, and 850-Watt load. The best BTE, BSFC, NOx and smoke emission obtained according to optimum work-ing parameters were found as 30.73%, 824.59 g/kWh, 292.20 ppm and 68.91%, respectively. Mean errors between experimental and optimized re-sults were found as 0.46%, 1.75%, 3.72% and 0.16% for BTE, BSFC, NOx and smoke emission, respectively. These results showed that the Taguchi de-sign method can be used as an effective tool to determine the impact rates of engine operating parameters and to optimize operating parameters, engine performance and emissions based on the determined impact rates.

Detection of Abandoned Coal Mine Goaf in China’s Ordos Basin Using the Transient Electromagnetic Method

Early coal mining and management methods left a large number of unknown goafs in China’s important Ordos Basin, which has restricted the safe production in today’s large-scale mines. The transient electromagnetic (TEM) method is the main geophysical tool used to detect the goaf. We considered the geological conditions of Ordos Basin in studying the optimal working parameters, electromagnetic (EM) interference, and terrain influence. The numerical simulation results of primary and secondary fields show that the most powerful abnormal signal can be obtained for the common 100 m deep goaf of the Ordos Basin by using a loop at least 240 m × 240 m. Time compensation and a polynomial fitting algorithm can be used to separate and weaken the TEM signal’s EM noise. The terrain height difference mainly affects TEM’s depth parameters, which can be modified to correct the topographic influence by considering the lateral continuity of the sedimentary strata. Three successful detection cases show that the study’s results can be used effectively in the Ordos Basin.

Rheological Behavior of Pure Molybdenum at High Temperature Considering Strain Compensation

The rheological behavior of pure molybdenum at a temperature range of 1150–1300 °C at an interval of 50 °C with strain rates ranging from 0.01 to 10 s−1 is studied by means of an isothermal compression experiment. The obtained true stress–strain curves reflect the strong dependence of the flow stress on the deformation temperatures and strain rates. To accurately describe the rheological behavior, a classic Arrhenius‐type equation is utilized for verification, which has been developed to consider the strain compensation. The results show that the modified constitutive equation has the ability to accurately predict performance. Meanwhile, processing maps of pure molybdenum under strains of 0.3, 0.4, 0.5, and 0.6 are also constructed and the deformation safety in different domains is discussed in conjunction with the metallographic structure. The deformation conditions at a temperature range of 1250–1300 °C and a strain rate of 0.01–0.23 s−1 are the optimal hot working parameters under a strain of 0.6, which creates a foundation for the effective hot forming of molybdenum.

Removal of 2,4-dichlorophenoxyacetic acid from aqueous samples using electrospun polyacrylonitrile nanofiber-based supported liquid membrane transport

In this work, a simple supported liquid membrane transport strategy is applied to remove of the dichlorophenoxyacetic acid (2,4-D) from water samples as important agricultural pesticides. Here, the electrospun polyacrylonitrile (PAN) nanofiber-based sheet has been used in the SLM process as new support. The optimal SLM transport working parameters were found to be pH = 1 and NaCl solution of 2 M for feed phase, dichloromethane as solvent of liquid membrane and pH = 14 and NaCl solution of 2 M for receiving phase. The stirring speed, time and temperature of SLM and the interference effect for 2,4-D transport have been studied and optimized. We find that the thickness of nano-electrospun PAN sheet as support of the liquid membrane has important effect on decreasing the time of transport. Under the same working conditions, this nano-based SLM method shows significant enhancement for removing efficiency and rate of 2,4-D rather than PAN microfiltration flat sheet as support material.

Modeling of the engine performance and exhaust emissions characteristics of a single-cylinder diesel using nano-biochar added into ethanol-biodiesel-diesel blends

This survey was aimed at investigating the effect of biodiesel/ethanol content, nano-biochar concentration, and engine speed on the engine performance and exhaust emission characteristics of a single-cylinder diesel engine. The different blend ratios of biodiesel/ethanol in neat diesel (0–8% by volume), nano-biochar particle concentrations (25–125 ppm), and engine speed (1800–2600 rpm) were used as input factors in RSM model. The experiments were designed, and models provided using the response surface method (RSM). All models derived for both engine performance and emissions variables were found to be statistically significant at a 95% confidence level. Interactive effects between the studied variables and responses were presented. In general, the inclusion of nano-biochar particles into diesel- biodiesel-ethanol blend showed a positive effect on both engine performance and exhaust emissions. The desirability approach based RSM was employed to predict the best engine working condition. The optimal engine working parameters for maximum engine performance and minimum exhaust emissions were identified as 2% biodiesel, 6% ethanol, 100 ppm nanoparticles, and 2123 rpm engine speed. The test results showed that at optimal parameters obtained, the values of the engine brake torque, power, BSFC, NOX, UHC, and CO were found to be 7.7 Nm, 1.7 kW, 219 g/kW h, 184 ppm, and 0.011%Vol., respectively.

Experimental study of the performance and emissions characteristics of fusel oil/gasoline blends in spark ignited engine using response surface methodology

The principal aim of this study is to use fusel oil which is a waste product obtaining as by-product from the ethanol production processes of sugar factories as an alternative energy source to gasoline in a spark ignition (SI) engine. The secondary purpose of this research is to define the optimum operating parameters such as compression ratio (CR), load and fusel oil percentage concerning the performance and emissions of SI engine by Response Surface Methodology (RSM). The tests of this research have been performed by several fusel oil–gasoline blends (0% and 30%), various CR (8.00, 8.50 and 9.12) and different engine load (1000, 2000, 3000, 4000, 5000 and 6000-W). According to obtained data from experiments, the RSM optimization is employed to maximize brake thermal efficiency (BTE) and minimize the brake specific fuel consumption (BSFC), nitrogen oxides (NOx), hydrocarbon emission (HC), carbon monoxide (CO) and carbon dioxide (CO2). RSM study showed that, fusel oil percentage of 30% at 8.39 CR and 3777-Watt engine load are the optimum engine operating parameters. Moreover, the optimum responses with a high desirability of 0.7685 were 22.47%, 391.43 g/kWh, 188.86 ppm, 12.46%, 1.78% and 131.91 ppm for BTE, BSFC, NOx, CO2, CO and HC emissions respectively. The results show that, RSM can help to estimate and optimize the optimum engine working parameters for improved the performance and emissions of engine with fewer tests. The outcomes stated future focus of similar research into optimization of fusel oil/gasoline fuel blends.

Design and test of a gravity-assisted vacuum seed-meter for maize

In order to improve the operating performance of vacuum seed-meter, a gravity-assisted seed filling method is provided. The radial components of seeds gravitational force and upper seeds pressure of seeds to be filled are consistent with the direction of drag force. Components of the seeds pressure and the gravity of seeds to be filled play an auxiliary role in seed filling. A gravity-assisted seed filling vacuum seed mater is designed, and the gravity-assisted seed filling mechanism and working principle are described. Operating performance of the designed seed-meter was evaluated by a two-factor indoor laboratory test and a single factor outdoor field test. Qualified index, double index, and missing index were estimated. Optimal working parameters combination of laboratory tests for operating velocity and air pressure were 6km/h and -4.5kPa respectively. Maximum field operating velocity was 9.48km/h. Optimum field operating velocity was 7.68km/h and qualified index, double index, missing index were 92.43%, 0.67%, and 6.9% respectively at this velocity.

Optimization of magnetic fluid hyperthermia with respect to nanoparticle shape-related parameters: case of magnetite ellipsoidal nanoparticles

Issues related to the optimization of heat transfer mechanisms dominated by superparamagnetic relaxation are considered in the case of AC (alternating current) magnetic field hyperthermia procedures. The key role in the conversion of electromagnetic energy to the thermal one via the superparamagnetic relaxation mechanism is played by the magnetic anisotropy of nanoparticles, easily to be controlled via the shape anisotropy component. The optimization process has been discussed in the case of magnetite (Fe3O4) ellipsoidal nanoparticles with dominant shape anisotropy dispersed in different media. Nanoparticles of different sizes and aspect ratios have been considered in correlation with those specific parameters of the actuating AC magnetic field which respect an established biological safely criterion. It has been proven that the dissipated power can be maximized for a given set of biological compatible RF (radiofrequency) field parameters (frequency and field amplitude at the sample space) only for specific pairs of particle sizes and aspect ratios. For instance, it has been shown that ellipsoidal magnetite nanoparticles with 10 nm equatorial size and aspect ratio of 2 are optimal for a maximum transferred power under radiofrequency excitations of 250 kHz and field amplitude of 20 kA/m, if high viscosity dispersion media are used. The methodology for deriving the optimal shape (geometrical) parameters of a specific type of nanoparticles in conditions of using available radiofrequency excitations, or vice versa, for deriving the optimal radiofrequency working parameters in the case of ferrofluids with specific nanoparticles (type and geometry) is described and discussed in detail.

Monitoring and diagnosis of the inductively coupled atmospheric pressure plasma jet for deterministic optical processing

Inductively coupled atmospheric pressure plasma processing (IC-APPP) is a promising figuring technique for the optical processing of silicon-based optics. However, its processing efficiency and accuracy rely on the stability of the characteristics of inductively coupled plasma (ICP) jet, which is determined by the jet working parameters. Currently, the jet working parameters have been empirically determined by substantial processing experiments, which is tedious and costly. Therefore, in this paper, a real-time monitoring and diagnostic system for quantitatively measuring and analyzing the jet characteristics is proposed to provide a basis for the choice of optimal working parameters. Firstly, the distributions of temperature and diatomic C2 within ICP jet were obtained, with which some diagnostic indices on the morphology, rigidity and excitation degree of ICP jet were proposed. Then, jet monitoring and diagnostic experiments were conducted to determine the optimal working parameters for generating the ICP jet with high rigidity and excitation degree. Finally, processing experiments under the determined optimal working parameters showed that the stability and repeatability of the removal function were well validated. It demonstrates that the proposed monitoring and diagnostic system is effective for rapid evaluation of ICP sources to determine the optimal working parameters for generating stable ICP jet.

PERFORMANCE TEST OF THE 2BDE-2 TYPE MILLET FINE AND SMALL-AMOUNT ELECTRIC SEEDER

This work designed a 2BDE-2 type millet fine and small-amount electric seeder to solve certain problems, such as difficult cultivation and large workload of millet in hilly and mountainous areas. This seeder can finish the sowing operations, such as ditching, fine and small-amount of seed discharging, covering soil and suppressing at one time. The central composite design method was used to test the seeding performance of the seeder along with the factors of the seed metering plate amplitude and operating speed. This task was undertaken to determine the optimal working parameters of the seeder. The mathematical model of the average number of seeds in each 100 mm section and the variation coefficient of seeding uniformity were established. The influence of single factor effects and interaction on the seeding performance was also analysed. The optimum combination after parameter optimisation was determined as follows: seed metering plate amplitude of 109 μm and seeder operating speed of 0.76 m/s. The field sowing experiment was conducted according to the parameter combination. Results showed that the average number of seeds in each 100 mm section was 7.8, and the variation coefficient of seeding uniformity was 19.64%. The relative errors with the predicted values were 1.28% and 4.98%. The research can be used for sowing a small amount of millet in the hilly mountain area.

Bioassay engineering: a combined label-free and fluorescence approach to optimize HER2 detection in complex biological media.

We report on the combined label-free/fluorescence use of one-dimensional photonic crystals to optimize cancer biomarker detection in complex biological media. The optimization of the assay working parameters permits us to maximize the final response of the biosensor. The detection approach utilizes a sandwich assay, in which one-dimensional photonic crystals sustaining Bloch surface waves are modified with monoclonal antibodies in order to guarantee high specificity during biological recognition. The multiple outcomes generated by such optimization experiments permitted us to determine the effective capture efficiency and the repeatability of the immobilization process, which was estimated to be close to 5%. By exploiting the resolution of the fluorescence operation mode, we studied non-specific interactions in different blocking agents, different analyte diluting buffers, and diverse concentrations of the detection antibody. As a clinically relevant biomarker, we selected the trans-membrane receptor tyrosine kinase HER2. HER2 regulates a variety of cell proliferation, growth, and differentiation pathways and its over-expression occurs in approximately 20-30% of breast cancer worldwide. As a final application, we transferred all the optimized working parameters to HER2 cancer biomarker assays in a complex biological environment. The label-free and fluorescence results obtained by analyzing MCF-7 (HER2 low positive) and 32D (HER2 negative) cell lysates demonstrate that we can successfully discriminate the two lysates.