Tunnel Conditions Research Articles

An intelligent detection method for precise analysis of shield tunnel lining joints based on deep learning networks and image morphology algorithms

ABSTRACT Leakage between adjacent lining blocks can cause severe secondary accidents, necessitating prompt joint inspection and repair. This study introduces an innovative framework to evaluate leakage of tunnel lining joints quantitatively. First, an enhanced two-stage detection model is proposed and utilised to predict joint bounding boxes. A novel backbone integrating Swin Transformer and sandglass blocks is used to capture both holistic and regional features. After the leakage joints are detected and located, leakage in the images is segmented based on the threshold algorithm, where a process containing image morphology algorithms is designed to enhance the quality and reasonability of the leakage masks. According to the characteristics of shield tunnels, the quantitative assessment method is proposed to obtain the areas of leakage regions. The mAP 50-95 of the proposed detector improves by 5.7% to 8.9% compared to previous methods, while the FPS reaches 15.68. The proposed method performs well on images larger than 400 × 400 pixels, and the AP 50 can exceed 80%. For the segmentation method, most IoUs between the manual and segmented masks are larger than 0.7. Thresholds specified in the Chinese standards are used to evaluate the leakage condition of an on-site tunnel, and maintenance guidance is given.

Assessment of drivers' visual search patterns and cognitive load during driving in curved tunnels.

The objective of this study was to assess drivers' visual search patterns and cognitive load during driving in curved tunnels. Specifically, we aimed to investigate how different curved tunnel geometries (tunnel radii, turning directions) and zones (entrance, middle, exit) influence drivers' saccadic eye movements. This understanding can inform the development of safer tunnel designs and driving guidelines. A total of 30 licensed Chinese drivers participated in the study. Eye movement data were collected using the eye tracker while participants drove through four experimental curved tunnels. Each tunnel differed in radius, turning direction, and zone. Eye movement parameters, including saccade duration, frequency, amplitude, and velocity, were analyzed to evaluate drivers' visual search patterns and cognitive load. The results revealed significant differences in drivers' saccadic eye movements across different tunnel conditions. As the tunnel radius decreased, drivers exhibited shorter saccade durations, increased saccade frequencies, decreased saccade amplitudes, and reduced saccade velocities, indicating increased cognitive load and more frequent visual updates. The turning direction also influenced saccadic behavior, with drivers demonstrating shorter saccade durations and higher frequencies when turning left compared to turning right. Furthermore, significant variations were observed across tunnel zones, with drivers showing the shortest saccade durations and highest frequencies in the entrance zone, while the mean saccade amplitude and velocity were largest in the exit zone. This study provides valuable insights into how drivers adapt their visual search strategies and cognitive processes in response to varying curved tunnel conditions. The findings highlight the importance of considering tunnel geometry, turning direction, and tunnel zones in designing safer tunnel infrastructures and driving guidelines. Specifically, the results suggest that drivers experience increased cognitive load in narrower tunnels and during left turns, necessitating a more dynamic and frequent visual search strategy.

Design Process for Scaled Model Wind Turbines Using Field Measurements

Abstract This paper presents a method for designing wind turbine-scaled models based on field data. The scaling process requires careful consideration of the system's physical laws and similarity criteria. Scaling methods depend on the prototype's operating conditions (full-size wind turbine) and the experimental conditions (scaled model dimensions and wind tunnel capabilities). The data from a field turbine are the input for creating a scaled model and testing it in a wind tunnel. There are few field data available. The task is not straightforward since most operating conditions must be satisfied, and the similarity criteria could result in different scaled models and wind tunnel conditions. The drawback of the scaling models is their inability to reproduce all the operating conditions. The method presented here considers most of the recommended similarities, including the dynamic modeling of the system and two additional similarities, one related to the blade's natural frequencies and the other to the rotor's moment of inertia. The additional similarities allow the designers to define the blade's mass and stiffness. The final scaled-model design was obtained by modifying the blade profile to reproduce similar power, pitch momentum, and trust coefficients, keeping the same twist angle as the prototype. Since the possible profiles are too large, the best approximation was obtained by comparing the coefficient curves of different blade profiles with the prototype's curves. The curves were calculated using the blade element momentum (BEM) method. It was found that the scaled model has an entirely different design.

Turbulence structure in a boundary layer wind tunnel

Turbulence spectral analysis is a critical aspect of wind tunnel experiments. In this study, a modification of the Mann uniform shear model (M94), based on the Rapid Distortion theory, is proposed to adapt M94 for wind tunnel conditions and model the complete second-order turbulence structure. First, the one-point spectra measured at heights ranging from 0.3 to 1.5 m are analyzed. The total absolute error χ2 for the modified M94 (M94-2) prediction is 0.998, compared to 1.6357 and 1.183 for M94 and the von Kármán spectral model, respectively; the results demonstrate the validity of the modification. Second, the spatial coherence is analyzed, with the spatial separations Δy and Δz ranging from 3.5 to 50 cm, M94-2 provides better predictions compared to the Krenk exponential coherence model. Notably, M94-2 is able to predict the turnaround of coherence at low wavenumber. Third, the phase angle of the cross-spectrum for two vertically separated points is predicted by M94-2, M94-2 tends to overestimate the measurement due to noise contamination. In conclusion, the anisotropic spectrum of boundary layer wind tunnel turbulence can be modeled by M94-2 effectively with three parameters: αε2/3, L, and Γ, and the entire work is conducted within a unified theoretical framework.

Hormonal efficiency and net return of BARI Tomato-4 enhanced under polytunnels during rainy summer season

An experiment was conducted at the department of Horticulture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh to evaluate the benefit cost ratio of summer tomato variety BARI tomato 4. The experiment was laid out in a split plot design with 18 treatments and three replications by maintaining a spacing of 60 cm x 40 cm. It comprised of two cultivation method as main plot viz. Open cultivation (P0) and Cultivation under poly tunnel (P1) and nine levels of growth regulators as sub-plot viz. T0 (Control), T1 (GA3@30 ppm), T2 (GA3@60 ppm), T3 (NAA @30 ppm), T4 (NAA @60 ppm), T5 (MH @30 ppm), T6 (MH @60 ppm), T7 (Tomatotone @30 ppm) and T8 (Tomatotone @60 ppm). Application of growth regulators was influenced in all studied parameters over control. Majority of the parameters responded better with the increased concentration of growth regulators. Tomatotone @ 60 ppm gave the highest yield per hectare (5.38 and 20.82 t) under open and poly tunnel condition, respectively. In open and poly tunnel condition, tomatotone @ 60 ppm showed the highest profitability and benefit cost ratio 1.16: 3.19, respectively. Despite of poly tunnel was being costly to establish (41% of total input cost), but it gave 3-4 times higher economic return. Higher values in respect of economy were obtained from the plants cultivated under poly tunnel with tomatotone @60 ppm. Therefore, tomatotone @ 60 ppm can be used as potential treatment for summer tomato cultivation under open and poly tunnel conditions to get highest profitability.

Effect of different Bradyrhizobium japonicum inoculants on physiological and agronomic traits of soybean (Glycine max (L.) Merr.) associated with different expression of nodulation genes

The aim of this work was to check the effects of five Bradyrhizobium japonicum inoculants from different producers on growth, photochemical efficiency, nitrate reductase activity, amount of hydrogen peroxide, activity of catalase, non-specific peroxidase, and superoxide dismutase, seed yield, and nodulation of soybean cv. ‘Malaga’. We also evaluated expression of such nodulation genes as NIC1, NOD21, and NORKb. The following inoculants were used: Nitragina IUNG, Nitragina Biofood, Nitroflora Mycoflor, Rhizobium Bio-Gen, and HiStick®Soy. The study was carried out on plants grown in pots in an open foil tunnel or glasshouse conditions. Experimental seeds were inoculated before sowing, while the control ones were not. Physiological and biochemical analyses involved the leaves, and gene expression was investigated in the roots. The bacterial inoculants significantly affected individual parameters of chlorophyll a fluorescence. The highest photochemical efficiency was induced by Nitroflora Mycoflor, which also activated nitrate reductase to the greatest extent. Nitragina IUNG most strongly stimulated accumulation of hydrogen peroxide, facilitated formation of the greatest number of nodules, and improved seed yield per plant in comparison with the control and other inoculants. Of the studied nodulation genes, NIC1 showed the strongest expression following HiStick®Soy treatment. Nitragina Biofood and Nitragina IUNG most significantly reduced the expression of all studied genes. Expression of NOD21 and NORKb exposed to other inoculants was the same as in the control plants. High content of hydrogen peroxide can be considered a marker of the inoculant ability to increase nodulation and yield of soybean. Commercial preparations containing the same amount of B. japonicum but different carriers of bacteria show different ability to form root nodules, and their differential impact on yield is related to the intensity of nodulation and expression of the Nod genes.

Validity and Reliability of Wind Speed Calculated by Notio in Comparison with a Hot-Wire Anemometer

Optimizing aerodynamic efficiency is crucial in competitive cycling, where aerodynamic resistance significantly limits performance. Devices like Notio have emerged to calculate the coefficient of drag area (CDA) considering dynamic pressure data calculated by an integrated Pitot-static tube. This study aimed to evaluate the validity and reliability of Pitot-static tube calculations through wind speed (WS) data against a hot-wire anemometer (HWA). Sixty recordings were made, lasting 30 s each, in a closed-circuit wind tunnel at four different WS (≈30 to ≈60 km/h), and at five different yaw angles (0° to 20°). Initially, Notio showed WS 6.44% higher than HWA. The calibration process recommended by the Notio manufacturer reduced the differences to a non-significant 0.76%. Comparison of the WS of Notio calibrated and HWA only showed significant differences in the WS group of ≈60 km/h. There were no significant differences in the comparison of yaw angles groups. The reliability of Notio was worse than that of the HWA. In conclusion, Notio calibrated at a speed close to its use allows for reliable and accurate calculation of WS over a wide range of yaw angles under controlled wind tunnel conditions without the presence of a cyclist and bicycle. However, due to the influence of WS on aerodynamic drag, small errors in WS could translate into considerable values of CDA for cycling performance.

The Effects of Fire Intensity on the Biochemical Properties of a Soil Under Scrub in the Pyrenean Subalpine Stage

Fire causes changes in many soil attributes, depending on multiple factors which are difficult to control in the field, such as maximum temperature, heat residence time, charred material incorporation, etc. The objective of this study is to evaluate the effect of a gradient of fire intensities on soils at the cm scale. Undisturbed topsoil monoliths were sampled under scrubs in the subalpine stage in the Southern Pyrenees (NE Spain). They were burned, under controlled conditions in a combustion tunnel, to obtain four charring intensities (CIs), combining two temperatures (50 and 80 °C) and two residence times (12 and 24 min) reached at 1 cm depth from the soil. Unburned soil samples were used as a control. All soils were sampled, cm by cm, up to 3 cm deep. The following soil properties were measured: soil respiration (basal, bSR and normalized, nSR), β-D-glucosidase (GLU), microbial biomass carbon (MBC), glomalin-related soil proteins (GRSPs), soil organic carbon (SOC), labile carbon (DOC), recalcitrant organic carbon (ROC), total nitrogen (TN), soil pH, electrical conductivity (EC) and soil water repellency (SWR). Even at low intensities, GLU, SOC and total GRSP were significantly reduced and, conversely, SWR was enhanced. At the higher CIs, additional soil properties were significantly reduced (MBC and C/N) or increased (DOC, ROC, nSR, easily extractable GRSP). This study demonstrates that there is a differential degree of thermal sensitivity in the measured biochemical soil properties. Furthermore, these properties are more affected at 0–1 cm than at 1–2 and 2–3 cm soil thicknesses.

Unraveling the complex interplay between curved tunnels and drivers’ physiological responses: An HRV perspective

This study aims to unravel the complex interplay between curved tunnels and drivers’ physiological responses from an HRV (Heart Rate Variability) perspective.A group of 30 individuals with valid driver’s licenses was selected, and their HRV was monitored while driving through four curved tunnels in Yunnan Province, China. HRV indicators such as RMSSD (Root Mean Square of Successive Differences), SDNN (Standard Deviation of Normal-to-Normal Intervals), LF (Low Frequency), and LF/HF (ratio of Low Frequency to High Frequency) were analyzed. The independent variables included tunnel radius, turn direction, and zone characteristics. The results demonstrated that the radius, turning, and zone of the curved tunnel significantly influenced drivers’ HRV. Specifically, as the tunnel radius decreased, the mean RMSSD and SDNN of drivers decreased, while the mean LF and LF/HF increased. In left turns, drivers had lower RMSSD and SDNN values but higher LF and LF/HF ratios compared to right turns. Additionally, drivers showed the highest mean RMSSD and SDNN in the entrance zone of the tunnel, followed by the middle zone, and the lowest in the exit zone. Conversely, the exit zone had the highest mean LF and LF/HF, followed by the middle zone, and the entrance zone had the lowest. These results indicate that the characteristics of the curved tunnel have a substantial impact on drivers’ physiological responses. A smaller tunnel radius leads to increased stress and cognitive load, as reflected by the decreased HRV metrics and increased sympathetic activity. Turning maneuvers, particularly left turns, result in asymmetry in autonomic responses, with lower RMSSD and SDNN and higher LF and LF/HF during left turns. The variations in HRV across different zones within the tunnel suggest that environmental cues play a role in sympathetic activation, with the exit zone showing the highest sympathetic activity. These findings offer significant insights into the relationship between tunnel conditions and drivers’ physiological responses, emphasizing the importance of considering these factors in road safety and human factors engineering. By comprehending how tunnel characteristics affect drivers’ autonomic nervous system responses, we can formulate strategies to enhance driver well-being and safety.

Theoretical analysis of stresses and displacements of twin tunnels excavated in saturated ground

The main objective of this study is to establish a general analytical model for investigating the hydro-mechanical problems of twin tunnels excavated in elastic saturated ground, taking into account the influence of seepage flow on the mechanical responses. All hydro-mechanical (HM) boundary conditions are satisfied to derive the analytical solutions. An innovative analytical complex function in the HM coupled framework, integrating complex variable theory and the Schwarz alternating method, has been developed with the consideration of arbitrary sizes and arrangements of twin tunnels. The convergence speed of the alternating method is quite fast, generally achieving enough accuracy within three iteration steps in the solving procedure, guaranteeing the application of the developed solutions in geotechnical engineering. The results obtained from these solutions match well with those of the numerical predictions, verifying the proposed analytical theory and the developed analytical solutions.Additionally, sensitivity analyses are performed to investigate mechanical responses of stresses and displacements of host rocks subjected to different engineering cases, including geometry and boundary conditions of twin tunnels. Results indicate a significant increase in the major principal stresses and deformations with rising seepage forces, suggesting that seepage flow can pose underground structures to dangerous conditions. Consequently, the influence of seepage flow plays a significant role in the stability analysis of tunnelling in water-rich geological areas. The proposed analytical approach offers an innovative and efficient alternative for the preliminary design of twin tunnels excavated in saturated ground, providing valuable insights for engineering applications.

Deep transfer learning for microseismic waveforms recognition across geological conditions in TBM tunnels

In deeply buried tunneling projects, geological conditions are often complex and varied. Microseismic monitoring systems are extensively deployed to enhance construction safety. However, when the current geological conditions differ from those present during the signal collection for model training, recognition accuracy tends to decline significantly. Therefore, improving the applicability and stability of microseismic waveform recognition models across varying geological conditions has emerged as a critical challenge. To address this issue, we first analyze the impact of lithological changes and the development of structural planes on the features of microseismic waveforms. Subsequently, we propose a category-domain-aligned transfer learning method that enables the transfer of recognition capabilities across geological conditions by facilitating similar feature extraction and the recognition of cross-geological fracture waveforms. In this model, feature separation modeling enhances the extraction of category features of waveforms under different geological conditions. A deep transfer learning mechanism distinguishes between unique and common features, allowing for the capture of essential features necessary for model parameter updates. Through comparative experiments and feature distribution alignment and visualization, we demonstrate that the accuracy of microseismic waveform recognition across geological conditions achieves 90 %. Additionally, the performance of our method is validated using microseismic signals collected from different sections of the construction site.

Numerical Investigation with Failure Characteristic Analysis and Support Effect Evaluation of Deep-Turning Roadways

In recent years, tunnel-boring machines (TBMs) have been widely applied in deep coal mining. Turning is an inevitable challenge in TBM tunneling, and a TBM turning roadway exhibits greater instability than a straight roadway, as engineering experience has indicated. This study aimed to explore the failure mechanism and evaluate the support performance of a deep-turning roadway. Several numerical models were established to investigate the deformation of the roadway, the stress distribution, and the failure zone of the surrounding rocks under different tunneling conditions. The results show that the tunneling depth influences the failure pattern of the turning roadway: deep tunneling with high in situ stress can cause asymmetric failure of the turning roadway, while shallow tunneling with low in situ stress does not. Moreover, the change in turning radius, namely the change in roadway geometry, does not influence the stability of the turning roadway. In addition, the support actions for both the straight and turning roadways do not differ significantly, and the amount of controlled deformation of the surrounding rocks is proportional to their natural deformation.

A Theoretical and Experimental Investigation of the Effects of Inverted Wings Modifications on the Stability and Aerodynamic Performance of a Sedan Car at Cornering

ABSTRACTThis research examines the impact of cornering on the aerodynamic forces and stability of a Nissan Versa (Almera) passenger sedan car by introducing novel modifications. These modifications included single inverted wings with end plates as a front spoiler, double‐element inverted wings with end plates as a rear spoiler, and incorporating the ground as a diffuser under the car trunk. The goal is to enhance the performance and stability of conventional passenger cars. To ensure the accuracy of the numerical data, the study utilized multiple methodologies to model the turbulence model, ultimately selecting the most suitable option. This involved comparing numerical data with wind tunnel experimental data using force balance and pressure distribution. Once validated, the computational fluid dynamics (CFD) was employed to analyze the vehicle's aerodynamic performance relative to the straight‐line condition under cornering conditions. The car simulation in a cornering condition was conducted at a representative Reynolds number based on the vehicle length of about 1.3 × 107. The study discovered that asymmetry was a recurring theme regarding surface pressure distribution, with greater prominence under cornering conditions. All modified models exhibited a more favorable lift‐to‐drag ratio than the baseline, indicating improved aerodynamic efficiency. The underbody double‐element diffuser proved most effective for enhancing fuel efficiency and stability. Mesh refinement with a polyhedral algorithm consisting of 11.27 million elements and a computational domain with a frontal area of 91.8 m2 and a curved length of 31 m (˜7 times car length) was crucial for achieving accurate and repeatable results. The study employed multiple turbulence models within the CFD framework. The realizable k‐ε model was chosen due to its balance between accuracy and computational cost for all Nissan Versa models. These findings are limited to the selected parameters and wind tunnel conditions, and further investigations might be needed for extreme driving scenarios.

Effect of Drip Irrigation Regimes and Mulching on Cucumber Production under Cooled Plastic Tunnel Conditions, Kassala State, Sudan

An experiment was conducted in a cooled plastic tunnel greenhouse during March-August of 2022 and 2023, the objectives of this study to investigate the effect of drip irrigation regimes and mulching on yield and yield components of cucumber under greenhouse conditions, Kassala, Sudan. Seedlings of the most popular cucumber hybrid (Fatin) were planted on 40cm and 50 cm inter and intra-row spacing, respectively. The experiment was composed of two factors; the irrigation regimes (75%, 100% and 125% of recommended irrigation water) and the other was mulching (mulching and no mulching). These factors were arranged in split plot design with three replications. The main plots were allocated for irrigation regimes and subplots for mulching. The subplot size was 200cm×70cm (bed/mastaba). Results reported that125% of recommended irrigation water (RIW) under drip irrigation recorded highest yield and yield components in both seasons. Moreover, the highest values of yield and yield components; fruit length, fruit diameter and fruit weight were obtained under 125% of (RIW) with mulch while, the lowest were obtained with75% of (RIW) without mulch on both seasons. The highest values of water productivity and economic water productivity were recorded under 125% of (RIW) with mulch. On the other hands, the highest marginal rate return (MRR) was obtained under 100% of (RIW) with no mulch.

In-tunnel pollutant concentration measurement and ventilation control indexes for highway tunnels in mountainous area: A case study of no.1 Qinling tunnel, China

The pollutant concentration and hygiene standards in mountain tunnels are key factors determining the ventilation effectiveness of tunnel operation. Previous studies have mainly focused on the spatiotemporal distribution patterns of in-tunnel pollutants, while research on ventilation control indexes for pollutants in long mountain tunnels are relatively limited. Therefore, this paper aims to discussing the hygiene control indexes for operational ventilation of mountain tunnels. Field tests were conducted in the No.1 Qinling Tunnel of Xi'an to Han zhong Highway in China, and the distribution laws of traffic flow, wind speed, and concentrations of particulate matter (PM), carbon monoxide (CO), and nitrogen oxide (NOX) were on-site measured. The spatiotemporal distribution characteristics of pollutants in the long mountain tunnel were revealed, and the ventilation hygiene control indexes for harmful gases were calculated and compared to those of urban highway tunnels. The results show that the traffic volume of operational highway tunnels in mountainous areas of China is increasing rapidly, and the particulate matter emitted from diesel vehicle exhaust will pose a threat to the normal environmental quality in the tunnel. The average value of CO base emission factor in 2000 for the upline of No.1 Qinling tunnel was 0.0019 m3/(veh·km) by back-calculation, and the annual decline rate of CO in the ventilation design for mountain highway tunnels should be 6 %–8 % and revised every 8 years. It is recommended to consider the geographical location and traffic conditions of mountain tunnels when calculating the air demand required for diluting NO2. NOx has basically replaced CO as the primary pollutant with the most significant impact on human health in mountain tunnels. It is recommended that NOX be considered as the primary hygiene control indicator in the ventilation design of mountain tunnels in China. The pollutant distribution and ventilation control indexes of mountain and urban highway tunnels are quite different, which should be treated differently in engineering applications. The research results can provide a significant reference for ventilation design and environmental evaluation of highway tunnels in mountainous areas.

Modeling Multi-Factor Coupled Pressure Fluctuations in EMU Trains under Extreme Tunnel Conditions

Modeling Multi-Factor Coupled Pressure Fluctuations in EMU Trains under Extreme Tunnel Conditions

Variability in strawberry tunnels impacts fruit quality and limits melatonin effects.

Fluctuations in environmental conditions within fields and crop plant performance can greatly affect production and quality standards. These factors are particularly relevant for producers, who require sustained optimal production to profit from small margins. Fluctuations might be exacerbated at the end of the crop season, where neither of the aforementioned factors are optimal. In the present integrated study, we assess strawberries' nutritional quality and the impact of harvest timing, tunnel conditions and inter-individual variability in a Mediterranean production tunnel divided into blocks, where two harvests were performed 3 weeks apart. In addition, the effects of sprayed melatonin at the end of productive season were also evaluated. End-season harvesting negatively impacted fruit hydration, antioxidant capacity and ripening-related hormones in strawberry fruits. Additionally, tunnel distribution influenced fruit nutritional quality, with light radiation being the main variable factor disturbing antioxidant contents. Nutrients exhibited high inter-individual plant variability, accounting for 20% variation, and were strongly correlated with fruit hydration and ripening-related phytohormones. Finally, melatonin applications affected neither fruit production, nor nutritional parameters, for which the effects were masked by the intrinsic strawberry variability. Overall, the results underline the limitations of this type of application for field implementation. Fruit quality variation in strawberry fields is explained by environmental and inter-individual variability. Likewise, the implementation of regulatory molecules such as melatonin in field applications relies on crop homogeneity and might have limited applicability in heterogeneous productive systems. Consequently, identifying and reducing microclimate variability in productive fields is paramount for advancing agricultural practices to uphold unwavering standards on fruit quality. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Comparative Study of Ginger Cultivars under Shading Conditions in a High Tunnel

Ginger (Zingiber officinale Rosc.) is a valuable sciophyte crop used as a spice or fresh herb in culinary dishes and for treating medical issues such as osteoarthritis, neurological diseases, vomiting, and asthma. The demand for ginger in the United States is remarkably high; it is produced commercially and exclusively in Hawaii but can only meet ∼20% of US demand. Light for ginger growth may be more important than is often assumed, but the roles of light in ginger growth and rhizome yield are not fully understood. We hypothesized that artificial shade would produce the highest yielding ginger compared with no shade. This study evaluated the impact of different shading suited for ginger growth and rhizome yield of different cultivars grown in a high tunnel. There were three levels (0%, 22%, and 40%) of shade using RCBD design. We analyzed the overall yield (weight) of ginger and the specific yield (weight) of different rhizome parts (biological root, edible root, and seed ginger) per plant in addition to plant growth data. Data were analyzed for 2018 and 2019, and shade conditions influenced ginger growth and yield. There was no significant difference between shade conditions or cultivars, but general trends found that data differed between the two growing seasons. In 2018, Chinese White and Hawaii Yellow produced a better (higher) yield under 0% and 40% shade. However, in 2019, Chinese White and Hawaii Yellow produced the highest total yield under 22% shade, but Bubba Blue produced the highest overall yield at 0% shade.

Specialty Melons Grown under High Tunnel Conditions Yield Good to Excellent Internal Quality

Interest in local foods, especially locally grown fruit, is increasing. High tunnel vegetable growers are strategically poised to meet this demand by growing specialty melons (Cucumis melo). Although specialty melons are commonly grown in high tunnels in other parts of the world, it is an uncommon practice in the midwestern United States. The objectives of this study were to evaluate 10 specialty melon cultivars for high tunnel production and measure fruit yield and internal quality. Fruit of the cultivar Eden’s Gem yielded the greatest number of marketable fruits per plant; however, these melons are small and have a loose cavity. Fruit of the cultivars Honey Orange and Divergent yielded the largest marketable fruit per plant with tighter cavities; however, the cavities were large. All cultivars had good to excellent internal quality in terms of sugar content. The production of specialty melons in the high tunnel was successful, resulting in the production of melons with good to excellent internal quality, and several yielded three to four marketable fruit per plant. Implementing a strong pest management plan for cucumber beetle (Diabrotica undecimpunctata howardi) and powdery mildew (Erysiphe cichoracearum, Sphaerotheca fuliginea) is recommended to prevent yield loss, especially in locations such as the Midwest, where cucumber beetles often vector bacterial wilt (Erwinia tracheiphila).

Study on the influence of combined utilization of air-fog curtain on fully mechanized face

To address the ambiguous regulations for dust control and removal in the joint use of air curtain and fog curtain, this study developed a multi-field coupling model of airflow, dust, and droplets. By incorporating the spraying method into both traditional ventilation technology and air curtain technology, this study comparatively analyzed the dust control and removal efficiencies of these two methods under various ventilation conditions in tunnels. The spray experiment and simulated result indicated a maximum relative error of 19.9 %. The simulation results demonstrated that the use of traditional ventilation technology resulted in significant dust contamination in the rear and top regions of the tunnel. Although the dust pollution was ameliorated when the pressure-suction ratio was 1.25, the dust control effect remained unsatisfactory, with the pollution distance extending 37.0 m. After implementing air curtain technology, the airflow generated a spiral air curtain due to the wall attachment effect, effectively confining the majority of dust to the heading face area. When the axial flow ratio was 45 %, the dust concentration at exceeding 13.0 m from the heading face dropped to blow 1.0 mg/m3, significantly reducing health risks for operators.