Field Experimental Data Research Articles

A Decision Support Software Application for the Design of Agrophotovoltaic Systems in Republic of Korea

Agrophotovoltaic (APV) systems produce both solar energy and crops, so they are considered a sustainable alternative to traditional solar power plants, which can potentially destroy farmlands. However, it is challenging to diffuse APV systems because of their high installation and operating costs. Thus, to resolve the issue by maximizing the productivity and profits of an APV system, this study aims to propose a mobile-phone-based decision support system (DSS) for a supply chain network design for APV systems in South Korea using satellite imagery incorporating geographic information system (GIS) data. Particularly, polynomial regression models estimating annual corn (Zea mays) yields and the predicted generation of electricity were developed and integrated with the proposed DSS. Field experiment data provided by the APV system at Jeollanamdo Agricultural Research and Extension Services in South Korea were utilized. Two photovoltaic (PV) module types (mono-facial and bi-facial) and three different shading ratios for APV systems (21.3%, 25.6%, and 32.0%) were considered design factors for APV systems. An optimal network structure of 6 candidate APV systems and 15 agricultural markets was devised using the generalized reduced gradient (GRG) method. The profits of the six candidate APV systems are mainly affected by the transportation costs to the markets and the policy of the electricity selling prices. As a result, the proposed supply chain design framework successfully identifies an APV system network with maximum profits from crop production as well as electricity generation.

Response of Hybrid Castor Under Different Fertility Gradient: Correlation Between Castor Yield and Normalized Difference Vegetation Index (NDVI) Under Inductive Cum Targeted Yield Model on an Alfisol

ABSTRACT Precision application of nutrient based on soil test value is important for improving nutrient use efficiency and yield of hybrid castor. Field trial was conducted during 2021 at Tapioca and Castor Research Station, Yethapur, Salem District, Tamil Nadu, India (11035’ N, 780 29’ E). Fertilizer prescription equations (FPEs) were developed for hybrid castor by adopting inductive cum targeted yield model approach under irrigated condition on Alfisol. Initially, soil fertility gradients were established with respect to soil available N, P and K nutrients, and 24 treatments were imposed in three fertility strips under factorial randomized design. Principle component analysis revealed that all the variables accounted for developing the FPEs of hybrid castor are present at the positive quadrant which mean that all the variables are highly important toward the castor seed yield production. From the field experimental data, the basic parameters [nutrient requirement (NR) and nutrients contributions from farmyard manure (Co), fertilizer (Cf), and soil (Cs)] were computed. The nutrient required for producing one quintal of hybrid castor seed yield was evaluated as 3.20 kg of nitrogen, 1.23 kg of phosphorus pentoxide (P2O5), and 3.28 kg of potassium oxide (K2O). The study revealed that soil nutrient contribution was high in case of available phosphorus (41.87%), available nitrogen (21.56%), and available potassium (19.12%), respectively, toward P, N, and K nutrient uptake by hybrid castor. The nutrient contribution from farmyard manure (Co) toward the total uptake was 21.40% of N, 10.35% of P2O5, and 26.06% of K2O, respectively. FPEs for hybrid castor and a ready reckoner of fertilizer dosages were developed using basic data for operational range of soil test values for intended yield target under inorganic fertilization alone and Integrated plant Nutrient System (IPNS) (NPK and FYM).

Target Tracking Algorithm Based on Generalized Regression Neural Network for Passive Bistatic Radar

In passive bistatic radar, high-performance target tracking is of crucial importance to a variety of applications. However, most existing tracking algorithms cannot achieve satisfactory performance due to poor azimuth estimation and the nonlinear relationship between target position and measurements. This paper proposes a novel tracking algorithm based on improved generalized regression neural networks (GRNN) and Kalman filtering (KF). First, the dependency between measurements and the target position is modeled by GRNN regression. A cooperative co-evolutionary genetic algorithm (CCGA) is then introduced to optimize the sample size and smoothing factor of the GRNN model to improve the performance. Finally, this paper applies KF to CCGA-GRNN localization results and forms the smoothing trajectories of the targets. Simulation and experimental results show that the performance of the proposed algorithm is better than that of the geometric localization (GL), GRNN, and extreme learning machine (ELM) based tracking approaches. Furthermore, field experiment data verifies the feasibility of the proposed algorithm.

The Estimation of Maize Grain Protein Content and Yield by Assimilating LAI and LNA, Retrieved from Canopy Remote Sensing Data, into the DSSAT Model

The assimilation of remote sensing data into mechanistic models of crop growth has become an available method for estimating yield. The objective of this study was to explore an effective assimilation approach for estimating maize grain protein content and yield using a canopy remote sensing data and crop growth model. Based on two years of field experiment data, the remote sensing inversion model using assimilation intermediate variables, namely leaf area index (LAI) and leaf nitrogen accumulation (LNA), was constructed with an R2 greater than 0.80 and a low root-mean-square error (RMSE). The different data assimilation approaches showed that when the LAI and LNA variables were used together in the assimilation process (VLAI+LNA), better accuracy was achieved for LNA estimations than the assimilation process using single variables of LAI or LNA (VLAI or VLNA). Similar differences in estimation accuracy were found in the maize yield and grain protein content (GPC) simulations. When the LAI and LNA were both intermediate variables in the assimilation process, the estimation accuracy of the yield and GPC were better than that of the assimilation process with only one variable. In summary, these results indicate that two physiological and biochemical parameters of maize retrieved from hyperspectral data can be combined with the crop growth model through the assimilation method, which provides a feasible method for improving the estimation accuracy of maize LAI, LNA, GPC and yield.

Assessing the Reliability of a New One-Line Model for Predicting Shoreline Evolution with Impoundment Field Experiment Data

The advancement of knowledge in the field of coastal morphodynamics is currently highly relevant, as it provides valuable insights into the complex and dynamic nature of coastal systems and helps coastal engineers and researchers to better understand and manage the risks associated with coastal hazards. Managing and protecting coastal areas requires accurate measurements and the availability of reliable numerical models for predicting shoreline evolution. The present study focuses on verifying the reliability of a recent one-line model: the General Shoreline beach (GSb) model. The numerical simulations were performed using wave data observed by the Acoustic Wave and Current profiler and the Channel Coast Observatory buoy. The numerical results were compared with high-resolution shoreline data collected from an ARGUS monitoring station during the impoundment experiment conducted in Milford-on-Sea, UK. The numerical results demonstrated that the GSb model accurately predicts shoreline evolution, particularly for mixed beaches. The findings of the present study also show the effectiveness of the GSb online numerical model in predicting day-to-day changes in shoreline dynamics caused by wave attack. The high-resolution dataset of the ARGUS observations combined with wave data collected during the field experiment could be valuable resources for coastal researchers to further evaluate and improve numerical models of coastal morphodynamics.

Derivation and validation of soil total and extractable cadmium criteria for safe vegetable production

Determining the appropriate soil cadmium (Cd) criteria for vegetable production is important for ensuring that the Cd concentrations of the vegetables meet food safety standards. The soil extractable Cd criteria for vegetable production are also essential for both food safety and environmental management, especially in areas with a high natural background level. In the present study, soil total and extractable Cd criteria were derived using the approach of species sensitivity distribution integrated with soil aging and bioavailability as affected by soil properties. A dataset of 90 vegetable species planted in different soils was compiled by screening the published in literature in five bibliographic databases using designated search strings. The empirical soil–plant transfer model was applied to normalize the bioaccumulation data. After normalization, the intra-species variability was reduced by 18.3 to 84.4%. The soil Cd concentration that would protect 95% (HC5) of the species was estimated by species sensitivity distribution curves that were fitted by the Burr III function. The soil Cd criteria derived from the added approach for risk assessment were proposed as continuous criteria based on a combination of organic carbon and pH in the soil. Criteria for total Cd and EDTA-extractable Cd in the soil ranged from 0.23 to 0.61 mg kg−1 and from 0.09 to 0.25 mg kg−1, respectively. Field experimental data were used to validate the applicability and validity of these criteria. Most of the predicted HC5 values in the field experimental sites were below the 1:1 line. These results provide a scientific basis for soil Cd criteria for vegetable production that will ensure food safety.

On ST6 Source Terms Model Assessment and Alternative

We present the study of the ST6 balanced set of wind energy input and wave energy dissipation due to wave breaking source terms, offered as the option in operational wave forecasting models and based on theoretical self-similarity analysis and numerical simulation of the wave energy radiative transfer equation. The study relies on the classical limited fetch wind wave excitation problem with constant wind blowing orthogonally to the shoreline toward the open ocean. It is found that the ST6 model exhibits asymptotic quasi self-similar behavior for fetches exceeding ≃25 km, as well as non-universal wave energy growth for shorter fetches, depending on the shoreline wave energy levels. We construct the alternative model PGZ-2 from a self-similar consideration, which reproduces field experimental data almost in the whole fetch span and reduces wave energy evolution dependence on the shoreline energy level. We assert that the PGZ-2 model is more accurate than the ST6 model. Moreover, it has a wider area of applicability.

Confirmation and chemical control of acetyl-CoA carboxylase- and acetolactate synthase-resistant Japanese foxtail in China

Japanese foxtail (Alopecurus japonicus Steud.) has developed resistance to multiple post-emergence herbicides in China. Hence, identification of alternative strategies for weed control using pre-emergence herbicides is urgently required. Therefore, we conducted greenhouse dose–response and field experiments over two wheat growing seasons at two sites in Xinyang City (CaiWan and LaoHuShan) to study resistance levels and effective chemical control strategies using the pre-emergence herbicides flufenacet and pyroxasulfone individually and tank-mixed. Greenhouse studies indicated that the CaiWan and LaoHuShan Japanese foxtail populations had a 5.1–35.3-fold resistance to acetyl-CoA carboxylase inhibitors and a 3.7–9.9-fold resistance to acetolactate synthase inhibitors, respectively. Field experiment data analyses revealed that pre-emergence herbicides applied before wheat sowing and immediately after wheat sowing provided >76% weed density and >82% weed biomass control efficiencies 30 and 90 days after sowing, respectively. They showed significantly higher results than herbicides applied after wheat was sown. Compared to the weedy check (control), flufenacet (300 and 450 g/ha), pyroxasulfone (180 and 240 g/ha), and their tank-mix (flufenacet at 300 + pyroxasulfone at 180 g/ha) significantly reduced weed density and biomass (P < 0.05). The tank-mix of flufenacet + pyroxasulfone consistently provided the highest weed control efficiency (85.3–94.5%). The tank-mix applied immediately after sowing resulted in the highest weed control efficiency (88.9–95.6%), the highest wheat yield (5470.3–5527.3 kg/ha), and no observed wheat injuries. However, multiple strategies, such as pre- and post-emergence herbicides, must be adopted to cope with high-density resistant weeds.

Assessment of Agricultural Drought Vulnerability Based on Crop Growth Stages: A Case Study of Huaibei Plain, China

Climate change can lead to and intensify drought disasters. Quantifying the vulnerability of disaster-affected elements is significant for understanding the mechanisms that transform drought intensity into eventual loss. This study proposed a growth-stage-based drought vulnerability index (GDVI) of soybean using meteorological, groundwater, land use, and field experiment data and crop growth model simulation. The CROPGRO-Soybean model was used to simulate crop growth and water deficit. Four growth stages were considered since the sensitivity of soybean to drought is strictly related to the growth stage. The GDVI was applied to the Huaibei Plain, Anhui Province, China, with the goal of quantifying the spatiotemporal characteristics of soybean drought vulnerability in typical years and growth stages. The results show that: (1) The sensitivity of leaf-related parameters exceeded that of other parameters during the vegetative growth stage, whereas the top weight and grain yield showed a higher sensitivity in the reproductive growth stage; (2) A semi-logarithmic law can describe the relationship between the drought sensitivity indicators and the GDVI during the four growth stages. The pod-filling phase is the most vulnerable stage for water deficit and with the highest loss upper limit (over 70%); (3) The 2001 and 2002 seasons were the driest time during 1997−2006. Fuyang and Huainan Cities were more vulnerable to drought than other regions on the Huaibei Plain in 2001, while Huaibei and Suzhou Cities were the most susceptible areas in 2002. The results could provide effective decision support for the categorization of areas vulnerable to droughts.

Improvement of Climate Resource Utilization Efficiency to Enhance Maize Yield through Adjusting Planting Density

The sustainable high yield of crops is critically important under the current situation of global climate warming. In order to improve regional yield, it is urgent to clarify the limiting factors of local grain yield and change the traditional planting measurements to adapt to the warming climate and make full use of climate resources. Long-term field experiments over seven years from 2014 to 2021 were conducted with the same maize cultivar (i.e., Luyu9105) with seven planting density treatments: 3.0 × 104 (D1), 4.5 × 104 (D2), 6.0 × 104 (D3), 7.5 × 104 (D4), 9.0 × 104 (D5), 10.5 × 104 (D6), and 12.0 × 104 (D7) plants per hectare in Taihe and Hefei, which belong to the southern Huang-Huai-Hai (SHHH) and southeast (SE) maize-producing areas in China. According to the field experiment data, differences in grain yield, ear number, kernel number per spike, and 1000-kernel weight of different treatments were analyzed. The utilization efficiency of climate resources in Taihe and Hefei was calculated using daily solar radiation, mean temperature, and precipitation data. The results showed that Taihe had 7.8% higher solar radiation during the growing season of maize than Hefei, while accumulated temperature ≥10 °C (AT10) was 3.9% lower than Hefei. The grain yields of different planting densities in Taihe were 9.7~23.6% higher than in Hefei. The agronomic optimal planting density (AOPD) was 8.6 × 104 plants ha−1 in Taihe and 8.0 × 104 plants ha−1 in Hefei. Compared to the actual grain yields, when the agronomic optimal planting densities were adopted, the simulated yield increased by 51.3% and 59.6%, respectively. The radiation utilization efficiency, temperature utilization efficiency, and precipitation utilization efficiency in Taihe were 12.9%, 24.6%, and 26.7% higher than the values of Hefei, respectively, and D4 and D5 treatments had significantly higher climatic resource utilization efficiency than D1 and D2 treatment. The grain yield was negatively correlated with accumulated temperature ≥10 °C and positively correlated with solar radiation. The multiple linear regression model among solar radiation, accumulated temperature was ≥10 °C, and grain yield was y = 0.550R−0.562AT10 + 14,593.6 (R = 0.379). Accumulated temperature ≥10 °C was the main climatic factor affecting the grain yield due to the higher occurrence probability of a maximum temperature ≥35 °C. Overall, in the future, increasing planting density and alleviating heat stress may enhance grain yield. These results could provide cultivation measurements with regional characteristics to adapt to the local climate and maximize the utilization efficiency of climatic resources.

Assessing long-term impacts of cover crops on soil organic carbon in the central US Midwestern agroecosystems.

Cover crops have been reported as one of the most effective practices to increase soil organic carbon (SOC) for agroecosystems. Impacts of cover crops on SOC change vary depending on soil properties, climate, and management practices, but it remains unclear how these control factors affect SOC benefits from cover crops, as well as which management practices can maximize SOC benefits. To address these questions, we used an advanced process-based agroecosystem model, ecosys, to assess the impacts of winter cover cropping on SOC accumulation under different environmental and management conditions. We aimed to answer the following questions: (1) To what extent do cover crops benefit SOC accumulation, and how do SOC benefits from cover crops vary with different factors (i.e., initial soil properties, cover crop types, climate during the cover crop growth period, and cover crop planting and terminating time)? (2) How can we enhance SOC benefits from cover crops under different cover crop management options? Specifically, we first calibrated and validated the ecosys model at two long-term field experiment sites with SOC measurements in Illinois. We then applied the ecosys model to six cover crop field experiment sites spanning across Illinois to assess the impacts of different factors on SOC accumulation. Our modeling results revealed the following findings: (1) Growing cover crops can bring SOC benefits by 0.33 ± 0.06 MgC ha-1 year-1 in six cover crop field experiment sites across Illinois, and the SOC benefits are species specific to legume and non-legume cover crops. (2) Initial SOC stocks and clay contents had overall small influences on SOC benefits from cover crops. During the cover crop growth period (i.e., winter and spring in the US Midwest), high temperature increased SOC benefits from cover crops, while the impacts from larger precipitation on SOC benefits varied field by field. (3) The SOC benefits from cover crops can be maximized by optimizing cover crop management practices (e.g., selecting cover crop types and controlling cover crop growth period) for the US Midwestern maize-soybean rotation system. Finally, we discussed the economic and policy implications of adopting cover crops in the US Midwest, including that current economic incentives to grow cover crops may not be sufficient to cover costs. This study systematically assessed cover crop impacts for SOC change in the US Midwest context, while also demonstrating that the ecosys model, with rigorous validation using field experiment data, can be an effective tool to guide the adaptive management of cover crops and quantify SOC benefits from cover crops. The study thus provides practical tools and insights for practitioners and policy-makers to design cover crop related government agricultural policies and incentive programs for farmers and agri-food related industries.

Spatiotemporal Changes in Frost-Free Season and Its Influence on Spring Wheat Potential Yield on the Qinghai–Tibet Plateau from 1978 to 2017

Accurately assessing the variation in the frost-free season (FFS) can provide decision support for improving agricultural adaptability and reducing frost harm; however, related studies were inadequate in terms of the Qinghai-Tibet Plateau (QTP). This study analyzed the spatiotemporal changes in the first frost day in autumn (FFA), last frost day in spring (LFS), FFS length and effective accumulated temperature (EAT) during the 1978-2017 period, and their influences on spring wheat potential yield on the QTP, based on daily climatic data and the methodology of Sen's slope and correlation analysis. The results showed that the annual average FFA and LFS occurred later and earlier from northwest to southeast, respectively, and both the FFS length and EAT increased. From 1978 to 2017, the average regional FFA and LFS were delayed and advanced at rates of 2.2 and 3.4 days per decade, and the FFS and EAT increased by 5.6 days and 102.7 °C·d per decade, respectively. Spatially, the increase rate of FFS length ranged from 2.8 to 11.2 days per decade throughout the QTP, and it was observed to be larger in northern Qinghai, central Tibet and Yunnan, and smaller mainly in eastern Sichuan and southern Tibet. Correspondingly, the increase rate for EAT ranged from 16.2 to 173.3 °C·d per decade and generally showed a downward trend from north to south. For a one-day increase in the FFS period, the spring wheat potential yield would decrease by 17.4 and 9.0 kg/ha in altitude ranges of <2000 m and 2000-3000 m, but decrease by 24.9 and 66.5 kg/ha in the ranges of 3000-4000 m and >4000 m, respectively. Future studies should be focused on exploring the influence of multiple climatic factors on crop production using experimental field data and model technologies to provide policy suggestions.

Analysis of the Influence of Pile-Raft Foundation Reinforcement on an Adjacent Existing Line Foundation

Pile-raft foundation reinforcement will have a certain impact on the adjacent existing line foundation, which will affect the normal service of the subgrade, and even lead to the instability of the subgrade. Until now, there have been few studies on adjacent construction problems, and there are few field experimental data available for us to consult. Therefore, this study relies on the construction project of Shanghai–Nanjing intercity high-speed railway close to the existing line, using in situ monitoring methods, such as stress shovels, horizontal strain gauges, and inclinometers combined with finite-element calculation and rail-inspection vehicle-data analysis. The stress, displacement, and geometric linearity of the adjacent existing line foundation during the reinforcement construction of a pile-raft foundation were studied. Our aim was to measure the impact and optimize the existing roadbed-protection measures employed during the construction period. We found that the cumulative horizontal displacement of the existing line foundation slope toe during the construction period was 24.25 mm, and the lateral displacement rate was less than 0.59 mm/d. The distance between the two lines was 9 m. The horizontal stress of the foundation soil in the depth range varied according to extrusion and retraction with the different construction stages, and the extrusion stress was less than 10 kPa. The horizontal stress changes in different construction stages were not obvious; the track quality index (TQI) in the existing track inspection during the construction period increased by 129.58%, and the existing track geometric linearity fluctuated greatly. According to the test results, the excavation stage of the subgrade foundation pit was the most dangerous stage of the existing subgrade during the construction of the new line pile-raft foundation. Although the change of the horizontal stress in different construction stages was not obvious, the horizontal displacement of the slope toe was sensitive to the construction process. Therefore, it could be used as a key indicator to monitor the deformation and stability of the existing subgrade. The correction coefficient was obtained by combining the detection data of the track-inspection vehicle with the finite element calculation data, based on which the accurate estimation of the horizontal displacement of the slope toe after the excavation of the foundation pit was realized. The monitoring and evaluation method of the stability of the existing line foundation under the influence of the pile-raft foundation reinforcement construction was preliminarily established through field monitoring and the analysis of the track-inspection data. Based on this method, relevant early warning values were proposed. The test results and engineering measures ensured the safe operation of the existing line foundation. This has important theoretical significance for guiding the construction of a new subgrade of adjacent existing lines.

Optimization design and performance investigation on the cascaded packed-bed thermal energy storage system with spherical capsules

Most of the previous researches on the cascaded packed-bed latent heat storage (CPTES) system are the thermal performance optimization based on numerical calculation. Experimental studies are few and mainly focus on single design parameter at low-temperature conditions. Lack of the detailed temperature - flow field experimental data and optimization scheme for the CPTES system. In this paper, an optimized two-layered filling structure of packed-bed heat storage system (OT-PTES) was proposed, which considers melting temperature of phase change material (PCM), capsule diameter, and filling volume ratio. The heat transfer process of PCM capsule and heat transfer fluid (HTF) during charging/discharging process were studied in detail by experiments. Under consistent working conditions, the average charging/discharging rate, total heat capacity, overall efficiency, and exergy efficiency was evaluated. And the influences of HTF inlet flow and the volume filling ratio of two-layered on thermal performance were analyzed. Finally, the concentric diffusion model was used to simulate the system to further optimize its hierarchical structure. The results are concluded as follows: (1) The temperature difference between PCM capsule and HTF at the interface changes continuously, and there is also an obvious temperature gradient in the radial direction of HTF, which improves the heat transfer efficiency. (2) Through experiments, the packed-bed with single large/small size PCM capsules are compared with the OT-PTES system. The overall efficiency of the latter is 74.2%, increased by 3.38% and 8.28%, and the exergy efficiency is 62.7%, increased by 7.5% and 52%. It is proved that the OT-PTES system has better charging/discharging performance. (3) When the volume filling rate = 1/2, the system has the best thermal performance (75.04%) and exergy efficiency (67.1%). (4) The numerical simulation results show that the overall performance of the packed-bed is optimal when the capsule size composition is 20–30 mm and the temperature difference of PCMs melting point is 60 ℃. In summary, OT-PTES is an optimized system with better heat storage performance. This study can provide experimental data support for the optimal design of the PLTES system and useful guidance for industrial applications.

The new sea ice thermodynamics code for the INM RAS Earth System model: The design and comparison of one- and zero-dimensional approaches with the observational data

Abstract This work is devoted to the comparison of one- (1-D) and zero-dimensional (0-D) models of sea ice thermodynamics. 1-D thermodynamics solvers imply the solution of the diffusion equation with penetrating radiation in the moving domain (moving boundary problem), while 0-D implementations neglect the heat capacity of ice and penetrating radiation, that leads to a linear temperature profile by the construction. So far, some climate models use 0-D implementation of thermodynamics in a block of sea ice, while other models use 1-D implementation with a small number of nodes. In this work we present our fully implicit 0-D and 1-D version of snow–ice thermodynamics, which relieves the model of Courant-type time step constraints. Implicitness is achieved by the relaxation method for nonlinear heat capacity and thermal conductivity coefficients with simultaneous search for the temperature that satisfies the boundary conditions. We introduce the experiment with analytical forcing to compare evolution of temperature profiles. This model experiment shows that 0-D model underestimates ice thickness and overestimates the amplitude of temperature profile variation compared to 1-D solution. Despite the large differences in thickness and internal temperatures, the surface temperatures are very close. The models were also validated on the data of the SHEBA field experiment. According to comparison with observation data, the 0-D model predicts ice thickness and spatiotemporal temperature distribution much worse compared to 1-D model, but the amplitude of error in surface temperature is slightly greater for 0-D code. It can be concluded that 0-D model of sea ice thermodynamics is a good tool for predicting surface temperature, but it gives a large error in thickness and temperature distribution.

Microbial consortia enhance the yield of maize under sub-humid rainfed production system of India

Plant beneficial microorganisms are being used to improve soil health and crop yield in different cropping systems. Maize is an important crop grown around the world for food, feed and raw material for various industries. The aim of the present study was to evaluate two microbial consortia viz., microbial consortia 1 (Pseudomonas putida P7 + Paenibacillus favisporus B30) and microbial consortia 2 (Pseudomonas putida P45 + Bacillus amyloliquefaciens B17) under field conditions for their suitability in improving maize yield under rainfed situations at Ballowal Saunkhri (Punjab) having sub-humid (Hot Dry) climatic conditions. Pooled analysis of three years field experiments data showed that, seed + soil application of microbial consortia 1 and 2 led to enhancement in grain yield of kharif maize by 27.78 and 23.21% respectively over uninoculated control. Likewise, significant increase in Benefit:Cost ratio as well as straw yield was also observed. The present investigation suggests that, microbial consortia would help in significantly improving the yield and economics of maize grown on inceptisols under rainfed conditions.

Mathematical modelling of stress-strain state of steel-concrete beams with combined reinforcement

Abstract Most of the modern computer software for the building structures‘ calculation is based on mathematical dependencies which make it possible to analyse rather complex stress-strain state of structures subjected to loading. As a rule, the calculation is based on the finite element method and is reduced to the calculation of deformations arising in structures due to the action of external forces with the use of real strain diagrams of materials, σ-ε diagrams for concrete and reinforcement. Modern normative regulations for reinforced concrete structures‘ calculation are also based on the deformation model using material deformation diagrams, which are as close to the real ones, as possible. Therefore, this study was aimed to investigate in more detail the stress-strain state and the physical essence of the processes occurring in reinforced concrete structures with combined reinforcement according to mathematical approaches and regulations of DBN B.2.6-98:2009 and DSTU B. In 2.6-156:2010. Namely, in the research is analysed the combined reinforcement of S245 steel tapes and A1000 rebar, which is used in the production of reinforced concrete elements. The results of mathematical modelling were compared with the calculation results, according to DBN B.2.6-98: 2009 and DSTU B. B 2.6-156:2010, as well as with field experimental data. Therefore, the conclusion could be made, whether it is possible to use this technique with sufficient accuracy to calculate reinforced concrete structures with combined reinforcement.

Innovation and Demonstration of a New CWDM and Circulator Integrated Semi-Active System for 5G Fronthaul

In response to emerging 5G fronthaul technology needs and low-cost scale deployment requirements, a novel CWDM and Circulator Integrated Semi-active system for 5G fronthaul is proposed. The proposed system can support six 25 Gbit/s fronthaul channels, protection switching, online real-time signal power detection of multiple working wavelengths, and reflected signal power detection. Laboratory and field experimental data demonstrate the system's availability, offering a new cost-effective approach for the deployment of 5G fronthaul systems at the operator scale.

Numerical Simulation and Analysis of Droplet Drift Motion under Different Wind Speed Environments of Single-Rotor Plant Protection UAVs

Unmanned aerial vehicles (UAVs) have been widely used in plant protection, and the mechanism of droplet deposition drift while spraying with the 3WQF120-12 produced by Quanfeng Aviation, a representative model of single-rotor plant protection UAVs in China, still requires more research. This study used a combination of computational fluid dynamics (CFD) and wind tunnel experiments to analyze the droplet deposition drift pattern of the 3WQF120-12 single-rotor plant protection UAV. The CFD modeling of the nozzle was confirmed to be feasible using wind tunnel experiments. Pearson correlation analysis was performed between experimental and simulated values, and multiple correlation coefficients reached above 0.89, which is a robust correlation. In this study, CFD simulations were performed to simulate the drift of UAV spray droplets under the rotor wind field and the combined effect of front and side winds. The deposition of droplets at different heights was simulated. The UAV’s spraying conditions at different flight speeds, side wind magnitudes, and spraying heights were evaluated. According to the CFD simulation results of the 3WQF120-12 plant protection UAV, the recommended flight height is 1–3 m, the recommended flight speed is below 3 m/s, and the recommended ambient wind speed is within 3 m/s. The simulation results were verified by the field test, and the trend of the field experimental data and CFD simulation results are qualitatively consistent to verify the reasonableness and feasibility of the simulation’s data. The simulated results were similar to the curves and spray area of the field test results at operating heights of 1.5 m and 3.5 m.

Reduced-scale experimental investigation on flow field characteristics of exhaust hood of double helix lifting transportation equipment in an industrial plant

In this study, the double screw lifting device of a rubber factory is taken as the case study object, and a scale model experiment was designed to determine the temperature field, velocity field and concentration field of pollutant escape of double spiral lifting transportation device are compared, and the capture efficiency is compared under the conditions of different dimensionless installation height and local exhaust hood air flow velocity Vexh. Reduced-scale experiments were conducted with a geometric scale of 1:4. Compared with no local exhaust hood, the concentration at the same measuring point decreases significantly under the action of local exhaust hood (dimensionless distances z/d = 3/4 and z/d = 2/4). Under the condition of maintaining the same local exhaust hood air flow velocity Vexh, the capture efficiency of local exhaust hood increased by 4% and 1% respectively on the dimensionless installation distance Z/D was 3/4 and 2/4 respectively. The experimental method of this case study and the air flow field experimental data obtained can provide a reference for the subsequent design and installation of exhaust hood.