bluuebunny/crossref_metadata_2025 huggingface dataset:
The Marginal Effect and LSTM Prediction Model under the Chinese Solar Greenhouse Film
Authors: Cheng Weiwei , Wang Yu , Wang Changchao , Liu Zhonghua
Published: July 2024

The solar greenhouse is a significant agricultural facility in China. It enables the cultivation of crops during periods that do not coincide with the natural growing season, thus alleviating the pressure on the supply of fruits and vegetables during the winter months. The primary rationale behind the necessity of greenhouse cultivation lies in the fact that the temperature conditions conducive to optimal crop growth can be precisely replicated within this controlled environment. However, it is important to acknowledge that a distinct low-temperature area persists under the film during the overwintering period, with the precise delineation of its boundaries and distribution patterns remaining uncertain. In order to investigate the characteristics of the temperature distribution within the marginal region under the solar greenhouse film, experimental studies, CFD simulations, and LSTM prediction models were employed. The results of these studies indicate that, during the overwintering period, a low-temperature region was observed with approximately equal temperatures near the film membrane. The maximum horizontal distance from the south-side bottom corner was 6130 mm, while the minimum height from the ground was 600 mm. The lowest temperature in the low-temperature region was 4 °C, and the maximum observed temperature difference within the same period in different months was 1 °C. Additionally, a region of elevated temperatures was observed under the film. The lowest temperature in this region was 36.7 °C, and the highest temperature point was within the optimal range for crop growth. The CFD numerical simulation results were consistent with the actual observations, and the LSTM prediction model demonstrated high reliability. The findings of this study offer a theoretical foundation for the distribution of high and low temperatures in solar greenhouses. Furthermore, the developed prediction model provides the necessary buffer time for control, thus enhancing the efficiency of greenhouse cultivation.
Computational Fluid Dynamics Model with Realistic Plant Structures to Study Airflow in and around a Plant Canopy on a Cultivation Shelf in a Plant Factory with Artificial Light
Authors: Gu Xuan , Goto Eiji
Published: July 2024

Airflow plays a crucial role in plant growth because it supplies CO2, O2, and energy to plants in a plant factory with artificial light (PFAL). Therefore, understanding how various factors affect airflow in and around a plant canopy is essential. In this study, we developed a computational fluid dynamics (CFD) model with realistic plant structures created using structure-from-motion imaging to investigate airflow in and around a plant canopy. The averages of the absolute percentage errors of simulated air velocity in three conditions were 6.7%, 10.1%, 12.7%, respectively. The simulated and measured air velocities agreed well, confirming the accuracy of the developed CFD model. The effects of inflow velocities and plant canopy structures on the airflow in and around the plant canopy were analysed using the validated CFD model. The inflow velocities significantly decreased stagnant zones (from 62.4% to 7.2%) and increased the airflow uniformity in and around the plant canopy. A staggered layout of the plant canopy slightly decreased stagnant zones (from 16.4% to 13.2%) and increased the airflow uniformity. The airflow in and around the plant canopy was further inhibited by a large plant structure. This CFD model provided a basis for improving the airflow status in and around a plant canopy in a PFAL.
A Comparative Study of Different Dimensionality Reduction Algorithms for Hyperspectral Prediction of Salt Information in Saline–Alkali Soils of Songnen Plain, China
Authors: Li Kai , Zhou Haoyun , Ren Jianhua , Liu Xiaozhen , Zhang Zhuopeng
Published: July 2024

Hyperspectral technology is widely recognized as an effective method for monitoring soil salinity. However, the traditional sieved samples often cannot reflect the true condition of the soil surface. In particular, there is a lack of research on the spectral response of cracked salt-affected soils despite the common occurrence of cohesive saline soil shrinkage and cracking during water evaporation. To address this research, a laboratory was designed to simulate the desiccation cracking progress of 57 soda saline–alkali soil samples with different salinity levels in the Songnen Plain of China. After completion of the drying process, spectroscopic analysis was conducted on the surface of all the cracked soil samples. Moreover, this study aimed to evaluate the predictive ability of multiple linear regression models (MLR) for four main salt parameters. The hyperspectral reflectance data was analyzed using three different band screening methods, namely random forest (RF), principal component analysis (PCA), and Pearson correlation analysis (R). The findings revealed a significant correlation between desiccation cracking and soil salinity, suggesting that salinity is the primary factor influencing surface cracking of saline–alkali soil in the Songnen Plain. The results of the modeling analysis also indicated that, regardless of the spectral dimensionality reduction method employed, salinity exhibited the highest prediction accuracy for soil salinity, followed by electrical conductivity (EC) and sodium (Na+), while the pH model exhibited the weakest predictive performance. In addition, the usage of RF for band selection has the best effect compared with PCA and Pearson methods, which allows salt information of soda saline–alkali soils in Songnen Plain to be predicted precisely.
Modeling the Discharge Rate of a Screw Conveyor Considering Hopper–Conveyor Coupling Parameters
Authors: Chen Peng , Huang Tianci , Wu Bei , Qian Huaiyuan , Xie Fangping , Liu Baohua , Liu Dawei , Li Xu
Published: July 2024

Developing a flow rate model for the screw feeder and optimizing discharge performance are crucial for achieving automated intelligent precision feeding. This study constructs a mass flow rate model for screw conveyors, considering the coupled structural parameters of the hopper and screw conveyor. The model is developed using single-factor tests and central composite design (CCD) response surface tests and is validated through actual discharge tests. Results indicate that the discharge rate in the hopper–screw conveyor system is primarily influenced by the screw conveyor itself. Among the structural parameters, the hopper inclination angle and the hopper discharge opening length significantly affect the filling coefficient. Validation tests show an average error of 6.8% between the predicted and simulated mass flow rates and 5.0% with the actual mass flow rate, demonstrating the model’s high precision and accuracy.
The Influence of the Distribution Law and Uniformity of a Threshed Mixture with the Working Parameters of a Soybean Threshing Device
Authors: Hu Yifan , Tang Zhong , Wang Shiguo , Li Bin , Guo Xiaohu , Chen Shuren
Published: July 2024

Soybean plants cultivated using mulched drip irrigation planting technology have the following characteristics during the harvest period: green stems and leaves, and a high straw/grain ratio. Moreover, the threshing device of a soybean combine harvester is difficult to adapt to, resulting in an increase in the accumulation and unevenness of the threshed mixture. This leads to an increase in impurity content and the loss rate. We conducted a single-factor experiment on a self-developed longitudinal/axial-flow soybean threshing and separation test bench, employing drum speed, feeding rate, and threshing clearance as experimental factors. The influence of the soybean threshing and separation device’s working parameters on the distribution and uniformity of the threshed mixture in the axial and radial directions of the drum was explored through experiments. The results showed that the mass of the threshed mixture and soybean seeds showed a trend of first rapidly increasing and then slowly decreasing in the axial direction of the drum. Additionally, the mass showed a distribution feature of large values on both sides and small values in the middle in the radial direction. A lower drum speed, greater threshing clearance, and a smaller feeding rate make the radial distribution of a threshed mixture more uniform. Based on the combination of the crushing rate and unthreshed rate, the optimal working parameter combination was determined to be as follows: a drum speed of 500 r/min, a feeding rate of 6 kg/s, and a threshing clearance of 25 mm. The findings of this research offer valuable insights for the structural optimization and design enhancement of threshing and cleaning mechanisms within soybean combine harvesters.
Combination of Polymer-Coated Urea and Rapid-Release Urea Increases Grain Yield and Nitrogen Use Efficiency of Rice by Improving Root and Shoot Activities
Authors: Xu Rongyue , Fu Jiangyao , Zhang Yajun , Sun Zhiwei , Xu Yuemei , Zhang Weiyang , Zhu Kuanyu , Gu Junfei , Wang Zhiqin , Yang Jianchang
Published: July 2024

The use of polymer-coated urea (PCU) can improve nitrogen use efficiency (NUE), compared to the application of rapid-release urea (RU). However, the effect of PCU-based nitrogen management on grain yield and the NUE of rice and its underlying mechanism remain unclear. A japonica rice cultivar Jinxiangyu 1 was grown in the field with four treatments including N omission (0N), split application of RU (Control), one-time application of 100% PCU (T1), and one-time application of 70% PCU + 30% RU (T2). Results showed that, compared to the control, the grain yield was significantly increased in the T2 treatment, while it was comparable in the T1 treatment. This was mainly due to increased total spikelets in the T2 treatment. Root oxidation activity (ROA) and root zeatin (Z) + zeatin riboside (ZR) content during booting were the distinct advantages of the T2 treatment, compared to either the control or T1 treatment, exhibiting significant or highly significant correlations with leaf photosynthesis. This process contributed significantly to total spikelets and total N uptake. Additionally, the T2 treatment absorbed more N than the control without reducing the internal N use efficiency (IEN), primarily due to its unchanged harvest index (HI) driven by comparable non-structural carbohydrate remobilization. In conclusion, combining PCU with RU can enhance the coordination of root and shoot traits during booting while maintaining a competitive HI at maturity, thereby significantly improving grain yield and achieving a balance in N uptake and utilization.
ICS-ResNet: A Lightweight Network for Maize Leaf Disease Classification
Authors: Ji Zhengjie , Bao Shudi , Chen Meng , Wei Linjing
Published: July 2024

The accurate identification of corn leaf diseases is crucial for preventing disease spread and improving corn yield. Plant leaf images are often affected by factors such as complex backgrounds, climate, light, and sample data imbalance. To address these issues, we propose a lightweight convolutional neural network, ICS-ResNet, based on ResNet50. This network incorporates improved spatial and channel attention modules as well as a deep separable residual structure to enhance recognition accuracy. (1) The residual connections in the ResNet network prevent gradient loss during deep network training. (2) The improved channel attention (ICA) and spatial attention (ISA) modules fully utilize semantic information from different feature layers to accurately localize key features of the network. (3) To reduce the number of parameters and lower computational costs, we replace traditional convolutional computation with a depth-separable residual structure. (4) We also employ cosine annealing to dynamically adjust the learning rate, enhancing the network’s training stability, improving model convergence, and preventing local optima. Experiments on the corn dataset in Plant Village compare the proposed ICS-ResNet with eight popular networks: CSPNet, InceptionNet_v3, EfficientNet, ShuffleNet, MobileNet, ResNet50, ResNet101 and ResNet152. The results show that the ICS-ResNet achieves an accuracy of 98.87%, which is 5.03%, 3.18%, 1.13%, 1.81%, 1.13%, 0.68%, 0.44% and 0.60% higher than the other networks, respectively. Furthermore, the number of parameters and computations are reduced by 69.21% and 54.88%, respectively, compared to the original ResNet50 network, significantly improving the efficiency of corn leaf disease classification. The study provides strong technical support for sustainable agriculture and the promotion of agricultural science and technology innovation.
Effects of Incubation Temperature and Sludge Addition on Soil Organic Carbon and Nitrogen Mineralization Characteristics in Degraded Grassland Soil
Authors: Min Xuxu , Xiao Lie , Li Zhanbin , Li Peng , Wang Feichao , Liu Xiaohuang , Chen Shuyi , Wang Zhou , Pan Lei
Published: July 2024

Elucidating the characteristics and underlying mechanisms of soil organic carbon (SOC) and nitrogen mineralization in the context of sludge addition is vital for enhancing soil quality and augmenting the carbon sink capacity of soil. This study examined the chemical properties, enzyme dynamics, and organic carbon and nitrogen mineralization processes of soil from degraded grasslands on the Loess Plateau at various incubation temperatures (5, 15, 25, and 35 °C) and sludge addition rates (0%, 5.0%, 10.0%, and 20.0%) through a laboratory incubation experiment. The results showed that incubation temperature, sludge addition, and their interactive effects significantly altered the soil enzyme C:N, C:P, and N:P stoichiometries. The cumulative mineralization rates of SOC and nitrogen increased significantly with increasing incubation temperature and sludge addition rate. Principal component analysis revealed a significant linear correlation between cumulative SOC and nitrogen mineralization. Random forest analysis indicated that β-1,4-Glucosidase (BG), β-1,4-N-acetyglucosaminidase (NAG), cellobiohydrolase (CBH), ammonium nitrogen (NO3−), enzyme C:P ratio, alkaline phosphatase (ALP), and incubation temperature were crucial determinants of cumulative SOC mineralization. Structural equation modeling demonstrated that sludge addition, NO3−, NAG, ALP, and enzyme C:P positively impacted SOC mineralization, whereas dissolved organic carbon and BG had negative impacts. Conversely, incubation temperature negatively affected soil nitrogen mineralization, whereas NO3−, available phosphorus, and ALP contributed positively. Sludge addition and temperature indirectly modulated soil net nitrogen mineralization by altering soil chemical properties and enzyme activities. These findings underscore the role of SOC and nitrogen mineralization as indicators for evaluating soil nutrient retention capabilities.
Biochar as an Alternative Litter Additive to Mitigate Gaseous Emissions from Broiler Housing and Subsequent Storage
Authors: Pereira José L. S. , Martins Filipa , Bonifácio Gabriel , Garcia Carla , Teixeira José , Trindade Henrique
Published: July 2024

Broiler farming is a significant source of gaseous emissions. The aim of this study was to assess the effects of different litter additives on the emission of NH3, N2O, CO2, and CH4 during broiler housing and subsequent manure storage. The gaseous emissions from the housing facilities were evaluated during one fattening cycle in environmentally controlled rooms with three different additives applied to the litter material (10% w/w aluminum sulphate or biochar and 2.50 mg m−2 urease inhibitor), as well as a control. A storage experiment was conducted under laboratory conditions for 90 days to evaluate the influence of these three additives on gaseous losses. During broiler housing, the results indicated that NH3 emissions were reduced significantly (40–60%) by litter additives, while global warming potential (GWP) emissions were reduced significantly (31%) by Alum. The addition of Biochar (a 58% reduction) had the same significant effect as Alum (a 60% reduction) to mitigate these losses. The re-application of Urease (a 41% reduction) may be required to reach an equal or higher reduction. During storage, NH3 and GWP emissions were not significantly affected by the litter additives. During broiler housing and subsequent manure storage, NH3 emissions were reduced significantly (22–41%) by litter additives, whereas GWP emissions did not decrease significantly. Globally, it can be concluded that Biochar appears to be a good alternative to Alum due to its equal effectiveness in mitigating NH3 losses, without increasing the GWP potential in the housing and avoiding pollution swapping.
Assessing Movements between Freshwater and Saltwater by Brown Trout (Salmo trutta L.) Based on Otolith Microchemistry
Authors: Andersson Magdalena , Jonsson Bror , Calles Olle , Greenberg Larry
Published: July 2024

By analyzing otolith microchemistry, we examined the use of freshwater and marine environments by brown trout Salmo trutta L. that spawn in the Swedish River Emån and migrate to the Baltic Sea. We estimated the time juveniles spent in freshwater and the number of times the fish returned to freshwater, presumably to spawn. Twenty-six percent of the fish migrated to sea by 1 year of age. However, 13% spent less than one year in the river. Most brown trout (48%) migrated to the sea between 1 and 2 years of age. On average, brown trout, which averaged 4.4 years in age (range 3–6 years), returned to freshwater 2.3 times, and there was an inverse relationship between time spent in freshwater after hatching and the number of visits to freshwater. Our results do not support the classical life history pattern, where brown trout spend one or more years in freshwater before migrating to the sea. Here, we found evidence that part of the population leaves freshwater during their first year. While the cause for precocial migration in the River Emån is not known, our results from this permanently flowing river do not support the idea proposed for other Baltic Sea populations, where the risk of drought has been suggested to be the cause.
Effects of Mink-Origin Enterococcus faecium on Growth Performance, Antioxidant Capacity, Immunity, and Intestinal Microbiota of Growing Male Minks
Authors: Cao Lin , Sun Fengxue , Ren Qifeng , Jiang Ziyi , Chen Jian , Li Yalin , Wang Lihua
Published: July 2024

The purpose of this experiment was to explore the effects of dietary Enterococcus faecium (EF) on the growth performance, antioxidant capacity, immunity, and intestinal microbiota of growing male minks. A total of 60 male Regal White minks at 12 weeks of age were randomly assigned to two groups, each with 15 replicates of two minks per replicate. The minks in two groups were fed the basal diets and the basal diets with viable Enterococcus faecium (more than 107 cfu/kg of diet), respectively. Compared with the minks in control, Enterococcus faecium minks had heavier body weight (BW) at week 4 and week 8 of the study (p < 0.05), greater average daily gain (ADG), and a lower feed/gain ratio (F/G) of male minks during the initial 4 weeks and the entire 8-week study period (p < 0.05). Furthermore, Enterococcus faecium increased the apparent digestibility of crude protein (CP) and dry matter (DM) compared to the control (p < 0.05). Moreover, Enterococcus faecium enhanced the serum superoxide dismutase (SOD) activity and decreased the malondialdehyde (MDA) contents (p < 0.05). The results also confirmed that Enterococcus faecium increased the levels of serum immunoglobulin A (IgA), immunoglobulin G (IgG), and the concentrations of secretory immunoglobulin A (SIgA) in the jejunal mucosa while decreasing the interleukin-8 (IL-8) and interleukin-1β (IL-1β) levels in the jejunal mucosa (p < 0.05). Intestinal microbiota analysis revealed that Enterococcus faecium increased the species numbers at the OUT level. Compared with the control, Enterococcus faecium had significant effects on the relative abundance of Paraclostridium, Brevinema, and Comamonas (p < 0.05). The results showed that Enterococcus faecium could improve the growth performance, increase the antioxidant capacity, improve the immunity of growing male minks, and also modulate the gut microbiota.
The Efficacy of β-Carotene in Cow Reproduction: A Review
Authors: Mitsuishi Hiroki , Yayota Masato
Published: July 2024

β-carotene supplementation improves the reproductive performance of cattle. However, the research results on this topic have been inconsistent, and no clear conclusion has been reached. In previous reviews of this topic, the functional mechanism of β-carotene in reproduction remained unclear, but subsequent studies have shown that the antioxidant effects of β-carotene protect enzymes involved in ovarian sex steroid hormone production from the effects of oxygen radicals. This role consequently affects normal ovarian follicle dynamics, maintenance of luteal function, and the estrous cycle, and indirectly improves reproductive performance by preventing perinatal diseases and facilitating recovery from these diseases. Several factors must be considered in feeding management to determine whether β-carotene supplementation is effective for improving reproductive performance in cows. The same is true when the animal consumes a large amount of the antioxidant β-carotene due to lactation, aging, or season. Therefore, it is important to consider the balance between the supply and consumption of β-carotene and evaluate whether β-carotene supplementation has an effect on reproductive performance in cows.
Fracture Mechanism and Damage Constitutive Model of Freeze–Thaw Fissured Granite Subjected to Fatigue Loading
Authors: Yun Mengchen , Ren Jianxi , Song Yongjun , Zhang Liang , Sun Chengwei , Chang Pengbo , Cao Xitailang
Published: July 2024

The failure of rock in cold regions due to repeated freeze–thaw (F-T) cycles and periodic load-induced fatigue damage presents a significant challenge. This study investigates the evolution of the multi-scale structure of fractured granite under combined freeze–thaw (F-T) cycles and periodic loading and develops a constitutive damage model. The results indicate that after F-T cycles, network cracks develop around pre-existing cracks, accompanied by block-like spalling. After applying the fatigue load, the nuclear magnetic resonance (NMR) T2 spectrum shifts to the right, significantly increasing the amplitude of the third peak. The freeze–thaw process induces a “liquid–solid” phase transition, weakening the original pore structure of the rocks and leading to meso-damage accumulation. The pores in fractured granite progressively enlarge and interconnect, reducing the rock’s load-bearing capacity and fatigue resistance. The combined effects of F-T cycles and periodic loading induce particle movement and alter fracture modes within the rock, subsequently affecting its macro-damage characteristics. The theoretical curves of the constitutive model align with the experimental data. The findings can serve as a theoretical reference for preventing and controlling engineering disasters in fractured rock masses in cold regions.
Transient Friction Analysis of Pressure Waves Propagating in Power-Law Non-Newtonian Fluids
Authors: Li Hang , Ruan Chenliang , Su Yanlin , Jia Peng , Wen Haojia , Zhu Xiuxing
Published: July 2024

Modulated pressure waves propagating in the drilling fluids inside the drill string are a reliable real-time communication technology that transmit data from downhole to the surface during oil and gas drilling. In the analysis of pressure waves’ propagation characteristics, the modeling of transient friction in non-Newtonian fluids remains a great challenge. This paper establishes a numerical model for transient pipe flow of power-law non-Newtonian fluids by using the weighted residual collocation method. Then, the Newton–Raphson method is applied to solve the nonlinear equations. The numerical method is validated by using the theoretical solution of Newtonian fluids and is proven to converge reliably with larger time steps. Finally, the influencing factors of the wall shear stress are analyzed using this numerical method. For shear-thinning fluids, the friction loss of periodic flow decreases with the increase in flow rate, which is opposite to the variation law of friction with the flow rate for stable pipe flow. Keeping the amplitude of pressure pulsation unchanged, an increase in frequency leads to a decrease in velocity fluctuations; therefore, the friction loss decreases with the increase in frequency.
Reproducibility of Three-Dimensional Density Measurements in Teeth Using Micro-Computed Tomography: An Image Acquisition Protocol
Authors: Huaiquin-Zúñiga Mary , Castillo-Alonso Camila , Fonseca Gabriel M. , López-Lázaro Sandra
Published: July 2024

The use of micro-computed tomography (micro-CT) has become widespread in the examination of dental tissue due to its great precision in small-scale work. Its usefulness in measuring tissue mineral density has been demonstrated; however, it is necessary to develop image acquisition protocols that ensure the reproducibility of observations and offer a detailed step-by-step process. This study proposes a standardised protocol to quantify mineral density using volumetric measurements from micro-CT images, evaluating the reproducibility of density measurements at different points of enamel and dentine. The sample comprised 30 bovine incisors that were scanned using a micro-CT system. Using the MIMICS software v.26, seven reference points in enamel and dentine (crown, cervix, and root) were identified, and mineral density was calculated by using Hounsfield units. The reproducibility of the measurements among the three observers was assessed by calculating Lin’s concordance correlation coefficient (CCC). There was substantial to almost perfect correlation for the enamel (CCC = 0.986–0.995) and dentine (CCC = 0.965–0.997), with the latter showing better results for the cervix (CCC = 0.987–0.997) and crown (CCC = 0.987–0.995) compared with the root (CCC = 0.965–0.985). In the lingual area, the concordance results were broader (CCC = 0.965–0.997) compared with the buccal area (CCC = 0.979–0.995). Despite this difference, the proposed volumetric measurements reached a high level of agreement, which demonstrates the replicability of the present protocol.
Using Transfer Learning to Realize Low Resource Dungan Language Speech Synthesis
Authors: Liu Mengrui , Jiang Rui , Yang Hongwu
Published: July 2024

This article presents a transfer-learning-based method to improve the synthesized speech quality of the low-resource Dungan language. This improvement is accomplished by fine-tuning a pre-trained Mandarin acoustic model to a Dungan language acoustic model using a limited Dungan corpus within the Tacotron2+WaveRNN framework. Our method begins with developing a transformer-based Dungan text analyzer capable of generating unit sequences with embedded prosodic information from Dungan sentences. These unit sequences, along with the speech features, provide  pairs as the input of Tacotron2 to train the acoustic model. Concurrently, we pre-trained a Tacotron2-based Mandarin acoustic model using a large-scale Mandarin corpus. The model is then fine-tuned with a small-scale Dungan speech corpus to derive a Dungan acoustic model that autonomously learns the alignment and mapping of the units to the spectrograms. The resulting spectrograms are converted into waveforms via the WaveRNN vocoder, facilitating the synthesis of high-quality Mandarin or Dungan speech. Both subjective and objective experiments suggest that the proposed transfer learning-based Dungan speech synthesis achieves superior scores compared to models trained only with the Dungan corpus and other methods. Consequently, our method offers a strategy to achieve speech synthesis for low-resource languages by adding prosodic information and leveraging a similar, high-resource language corpus through transfer learning.
A Study on Three-Dimensional Multi-Cluster Fracturing Simulation under the Influence of Natural Fractures
Authors: Li Yuegang , Wu Mingyang , Huang Haoyong , Guo Yintong , Wang Yujie , Gui Junchuan , Lu Jun
Published: July 2024

Multi-cluster fracturing has emerged as an effective technique for enhancing the productivity of deep shale reservoirs. The presence of natural bedding planes in these reservoirs plays a significant role in shaping the evolution and development of multi-cluster hydraulic fractures. Therefore, conducting detailed research on the propagation mechanisms of multi-cluster hydraulic fractures in deep shale formations is crucial for optimizing reservoir transformation efficiency and achieving effective development outcomes. This study employs the finite discrete element method (FDEM) to construct a comprehensive three-dimensional simulation model of multi-cluster fracturing, considering the number of natural fractures present and the geo-mechanical characteristics of a target block. The propagation of hydraulic fractures is investigated in response to the number of natural fractures and the design of the multi-cluster fracturing operations. The simulation results show that, consistent with previous research on fracturing in shale oil and gas reservoirs, an increase in the number of fracturing clusters and natural fractures leads to a larger total area covered by artificial fractures and the development of more intricate fracture patterns. Furthermore, the present study highlights that an escalation in the number of fracturing clusters results in a notable reduction in the balanced expansion of the double wings of the main fracture within the reservoir. Instead, the effects of natural fractures, geo-stress, and other factors contribute to enhanced phenomena such as single-wing expansion, bifurcation, and the bending of different main fractures, facilitating the creation of complex artificial fracture networks. It is important to note that the presence of natural fractures can also significantly alter the failure mode of artificial fractures, potentially resulting in the formation of small opening shear fractures that necessitate careful evaluation of the overall renovation impact. Moreover, this study demonstrates that even in comparison to single-cluster fracturing, the presence of 40 natural main fractures in the region can lead to the development of multiple branching main fractures. This finding underscores the importance of considering natural fractures in deep reservoir fracturing operations. In conclusion, the findings of this study offer valuable insights for optimizing deep reservoir fracturing processes in scenarios where natural fractures play a vital role in shaping fracture development.
Effect of Pulsed Electromagnetic Field Stimulation on Splenomegaly and Immunoglobulin E Levels in 2,4-Dinitrochlorobenzene-Induced Atopic Dermatitis Mouse Model
Authors: Kim Jun-Young , Hong Ju-Eun , Woo Sung-Hun , Rhee Ki-Jong , Kim Yoon Suk , Lee Yong-Heum
Published: July 2024

Effects of pulsed electromagnetic fields (PEMF) on immunological factors in a 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD) model were investigated. Hairless mice were randomly assigned to control, acetone and olive oil solution-treated (AOO), PEMF 15 Hz, PEMF 75 Hz, and sham groups (n = 5 each). AOO solution was used to dissolve DNCB. Both PEMF and sham groups were exposed to similar DNCB doses, causing similar AD symptoms. After AD induction for five weeks, only the PEMF groups were exposed to PEMF stimulations (15 Hz, 75 Hz, and 15 mT) inside the solenoid coil, for two weeks. In both groups, splenomegaly was observed, as AD was induced by hyperimmune reactions caused by DNCB sensitization. However, splenomegaly did not occur in the PEMF-exposed groups, and spleen weight decreased similarly to that of the control. Hence, the total splenocytes in the PEMF group were similar to those in the control group, whereas the sham group showed three times the number of splenocytes compared with the PEMF group. The serum immunoglobulin E levels did not significantly change in the PEMF group; however, they increased more than fourfold in the sham group. These results demonstrate that PEMF stimulation ameliorated the abnormal symptoms caused by hyperimmune reactions.
Continuous Wave Mode Test of Conduction-Cooled Nb3Sn Radio Frequency Superconducting Cavities at Peking University
Authors: Ren Manqian , Lin Lin , Hao Jiankui , Wang Gai , Wang Ziyu , Wang Deyang , Shen Haoyu , Quan Shengwen , Wang Fang , Feng Liwen , Jiao Fei , Zhu Feng , Zhu Kun , Yan Xueqing , Huang Senlin
Published: July 2024

A liquid helium-free cryostat for radio frequency (RF) test of the superconducting cavity is designed and constructed. Gifford-Mcmahon (G-M) cryocoolers are used to provide cooling capacity, and the heat leakage at 4 K is less than 0.02 W. Vertical and horizontal tests of two Nb3Sn cavities are carried out in the cryostat with different surface treatments outside the cavities. Both of the cavities achieve stable continuous wave (CW) operation. A novel treatment, which cold-sprayed a 3.5 mm thick Cu layer onto the outside of the cavity, enables the maintenance of an average temperature of 5.5 K in the cavity at a RF loss of 10 W, implying that the thermal stability and uniformity of the cavity has been significantly improved. Through the synergistic control of four metal film resistors, a cooling rate of 0.06 K/min near 18 K is realized, and the cavity temperature gradient is reduced to 0.17 K/m, which effectively improves the RF performance of the cavity. The maximum Eacc of the cavity reaches 3.42 MV/m, and the Q0 is 1.1 × 109. An electromagnetic–thermal coupling simulation model for the superconducting cavity is established and is in good agreement with the experimental results. The simulation results show that the cavity with a Cu-spraying treatment and the thermal links of 5N Al can satisfy the Eacc of 10 MV/m under conduction cooling.
Skip-Gram and Transformer Model for Session-Based Recommendation
Authors: Celik Enes , Ilhan Omurca Sevinc
Published: July 2024

Session-based recommendation uses past clicks and interaction sequences from anonymous users to predict the next item most likely to be clicked. Predicting the user’s subsequent behavior in online transactions becomes a problem mainly due to the lack of user information and limited behavioral information. Existing methods, such as recurrent neural network (RNN)-based models that model user’s past behavior sequences and graph neural network (GNN)-based models that capture potential relationships between items, miss different time intervals in the past behavior sequence and can only capture certain types of user interest patterns due to the characteristics of neural networks. Graphic models created to improve the current session reduce the model’s success due to the addition of irrelevant items. Moreover, attention mechanisms in recent approaches have been insufficient due to weak representations of users and products. In this study, we propose a model based on the combination of skip-gram and transformer (SkipGT) to solve the above-mentioned drawbacks in session-based recommendation systems. In the proposed method, skip-gram both captures chained user interest in the session thread through item-specific subreddits and learns complex interaction information between items. The proposed method captures short-term and long-term preference representations to predict the next click with the help of a transformer. The transformer in our proposed model overcomes many limitations in turn-based models and models longer contextual connections between items more effectively. In our proposed model, by giving the transformer trained item embeddings from the skip-gram model as input, the transformer has better performance because it does not learn item representations from scratch. By conducting extensive experiments with three real-world datasets, we confirm that SkipGT significantly outperforms state-of-the-art solutions with an average MRR score of 5.58%.
Slope Stability Analysis of Rockfill Embankments Considering Stress-Dependent Spatial Variability in Friction Angle of Granular Materials
Authors: Ran Congyong , Zhou Zhengjun , Lu Xiang , Gong Binfeng , Jiang Yuanyuan , Wu Zhenyu
Published: July 2024

Slope stability is a major safety concern of rockfill embankments. Since rockfills are incohesive materials, only friction angle is considered as a shear strength parameter in the slope stability analysis of rockfill embankments. Recently, it was found that confining pressure can significantly affect the mean value and variance of the friction angle of rockfills. Since the confining pressure spatially varies within a rockfill embankment, the effect of stress-dependent spatial variability in the friction angle of rockfills should be investigated for slope stability evaluation of rockfill embankments. In the framework of the Limit Equilibrium Method (LEM), an approach is proposed for the slope stability analysis of rockfill embankments considering the stress-dependent spatial variability in the friction angle. The safety factors of slope stability are computed with variable values of the friction angle at the bases of slices which are determined by the stress-dependent mean value and variance of the friction angle of rockfills. The slope stability of a homogeneous rockfill embankment is analyzed to illustrate the proposed approach, and a parametric analysis is carried out to explore the effect of variation in the parameters of the variance function of friction angle on slope stability. The illustrative example demonstrates that the stress-dependent spatial variability of friction angle along the slip surface is obvious and is affected by the location of the slip surface and the loading condition. The effects of the stress-dependent spatial variability of the friction angle on the slope stability of high rockfill embankments should be considered.
Optimized Discrete Nonlinear Control of Alternating Current Three-Phase Motors via an Industrial Variable Frequency Drive
Authors: Cervantes-Escorcia Nicolás , Santos-Sánchez Omar-Jacobo , Rodríguez-Guerrero Liliam , Romero-Trejo Hugo , García-Pérez Orlando
Published: July 2024

This article presents a suboptimal nonlinear control strategy to improve the dynamics of a three-phase alternating current (AC) motor. Using dynamic programming, the calculation of the Bellman function is avoided by determining a suboptimal control sequence that locally minimizes a quadratic performance index at each step. The motor’s fixed-frame nonlinear mathematical model controls the stator currents, rotor magnetic fluxes, and rotor angular speed by applying voltages to the stator. Experimental tests are conducted using a Delta VFD007EL11A variable frequency drive (VFD), demonstrating improved motor state behavior and performance compared to an optimal proportional integral (PI) control and a fixed reference input in the VFD. The experiments include set point changes and a comparative analysis of the energy consumption between both controllers considering two cases: free and with load on the motor shaft.
Study on Deformation Control of Road-Deep Foundation Pit Passing under Elevated Subway Bridge
Authors: Peng Hua , Meng Bowen , Tan Sui , Zhu Li , Wang Guan
Published: July 2024

This paper focuses on the application of pile foundation underpinning technology in a deep foundation pit of a subway Viaduct Project in Beijing. The study aims to address the engineering characteristics of the project, including a large number of new piles, a wide span of underpinning abutment, a long length of deep foundation pit, and a wide range of influences. This research utilizes field monitoring and numerical simulation methods to investigate the pile foundation underpinnings. The impact and management of road-deep foundation pit construction are considered, as well as their combined effect on subway viaducts and track structures. The primary accomplishments are as follows: (1) By analyzing the data from on-site deformation monitoring, it is evident that the pier exhibits maximum vertical deformation and maximum transverse deformation at the same location. The measuring locations are specifically situated on Pier 7# at the pile foundation underpinning. The maximum vertical and transverse deformations of the track are directly proportional to the maximum deformation of the pier. (2) By comparing the numerical simulation results with the field monitoring data, it is observed that although there is some discrepancy between the two, the deformation trend is largely consistent. This suggests that the numerical simulation analysis method is effective in reflecting the deformation of the bridge and track. (3) Through the numerical model and changing the values of the retaining structure parameters, the sensitivity of the pier deformation near the road foundation pit to the retaining structure parameters is systematically analyzed. The sensitivity of the pier deformation to the foundation pit parameters is as follows: the embedded depth insertion ratio of the retaining pile > the diameter of the retaining pile > the pile spacing.
Fragments of the Liturgical-Musical Codex from the Archdiocesan Archive of Gniezno (Poland): Source Analysis and Provenance Hypotheses
Authors: Wiśniewski Piotr
Published: July 2024

This paper discusses hitherto unidentified loose folios of a parchment liturgical and musical book held in the Archdiocesan Archive of Gniezno (Poland), containing the offertory and communion antiphons for the feasts De Trinitate and Corpus Christi. The author provides the codicological description of the leaves (analyzing Latin script, musical notation, ornamentation); identifies the time of their creation (15th century); indicates the type of the liturgical book to which they belong (graduale); seeks a melodic model for them and puts forward provenance hypotheses. He states that the melodics of the antiphons, although closest to the Cistercian tradition, are nevertheless variantly different from the melodic line preserved in foreign and Polish codices. It is possible to narrow down the dating of the leaves thanks to the type of Latin script, the calligraphic ornamentation of the initials and the spelling of certain letters.
The Impact of Pentraxin 3 Serum Levels and Angiotensin-Converting Enzyme Polymorphism on Pulmonary Infiltrates and Mortality in COVID-19 Patients
Authors: Krivdić Dupan Zdravka , Periša Vlatka , Suver Stević Mirjana , Mihalj Martina , Tolušić Levak Maja , Guljaš Silva , Salha Tamer , Loinjak Domagoj , Kos Martina , Šapina Matej , Canjko Ivana , Šambić Penc Mirela , Štefančić Marin , Nešković Nenad
Published: July 2024

Objectives: The aim of this study was to examine the impact of the pentraxin 3 (PTX3) serum level and angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism on the severity of radiographic pulmonary infiltrates and the clinical outcomes of COVID-19. Methods: The severity of COVID-19 pulmonary infiltrates was evaluated within a week of admission by analyzing chest X-rays (CXR) using the modified Brixia (MBrixa) scoring system. The insertion (I)/deletion (D) polymorphism of the ACE gene and the serum levels of PTX3 were determined for all patients included in the study. Results: This study included 80 patients. Using a cut-off serum level of PTX3 ≥ 2.765 ng/mL, the ROC analysis (AUC 0.871, 95% CI 0.787–0.954, p < 0.001) showed a sensitivity of 85.7% and specificity of 78.8% in predicting severe MBrixa scores. Compared to ACE I/I polymorphism, D/D polymorphism significantly increased the risk of severe CXR infiltrates, OR 7.7 (95% CI: 1.9–30.1), and p = 0.002. Significant independent predictors of severe CXR infiltrates include hypertension (OR 7.71), PTX3 (OR 1.20), and ACE D/D polymorphism (OR 18.72). Hypertension (OR 6.91), PTX3 (OR 1.47), and ACE I/I polymorphism (OR 0.09) are significant predictors of poor outcomes. Conclusion: PTX3 and ACE D/D polymorphism are significant predictors of the severity of COVID-19 pneumonia. PTX3 is a significant predictor of death.
CRISPR-Cas System, Antimicrobial Resistance, and Enterococcus Genus—A Complicated Relationship
Authors: Costache Carmen , Colosi Ioana , Toc Dan-Alexandru , Daian Karla , Damacus David , Botan Alexandru , Toc Adelina , Pana Adrian Gabriel , Panaitescu Paul , Neculicioiu Vlad , Schiopu Pavel , Iordache Dumitrana , Butiuc-Keul Anca
Published: July 2024

(1) Background: The rise in antibiotic resistant bacteria poses a significant threat to public health worldwide, necessitating innovative solutions. This study explores the role of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) in the context of antibiotic resistance among different species from the Enterococcus genus. (2) Methods: The genomes of Enterococcus included in the study were analyzed using CRISPRCasFinder to distinguish between CRISPR-positive (level 4 CRISPR) and CRISPR-negative genomes. Antibiotic resistance genes were identified, and a comparative analysis explored potential associations between CRISPR presence and antibiotic resistance profiles in Enterococcus species. (3) Results: Out of ten antibiotic resistance genes found in Enterococcus species, only one, the efmA gene, showed a strong association with CRISPR-negative isolates, while the others did not significantly differ between CRISPR-positive and CRISPR-negative Enterococcus genomes. (4) Conclusion: These findings indicate that the efmA gene may be more prevalent in CRISPR-negative Enterococcus genomes, and they may contribute to a better understanding of the molecular mechanisms underlying the acquisition of antibiotic resistance genes in Enterococcus species.
Capacitive Neuromodulation via Material-Based Passive Interaction: Efficacy in Motor Function Improvement in Parkinson Disease
Authors: D’Errico Fabrizio , Serio Francesco , Carioni Gianluigi
Published: July 2024

A non-invasive and non-pharmacological approach is evaluated for the proprioceptive and postural improvement of PD subjects. The authors evaluated the effectiveness of a class I medical device according to EU regulation 745/2017 designed to develop the mechanism of action based on the modulation of action potentials, which occurs in prevalent pathways of the afferent peripheral nervous system efferent in subjects with spasticity. The present observational study, structured in a double-blind randomized manner, therefore, had the main aim of evaluating the ability of the device to improve on the motor and proprioceptive function of PD patients. This study was based on the instrumented gait analysis performed according to the Timed Up and Go (TUG) test procedure, as well as using a fall risk assessment in accordance with the Berg Balance Scale (BBS) procedures. This study involved 25 participants in the active group (no placebo) and 25 in the non-active group (placebo), the latter to whom non-functional devices were applied, but in every respect identical to the functional devices applied to the 25 patients in the no placebo group. Data analysis was conducted using statistical methodologies for statistics, the statistical significance of the results for the observed samples and the interdependence between the measured variables. The study of the mechanism of action based on the remodulation of action potentials was preliminary conducted through numerical modeling of the Hodgkin–Huxley axon, modified by introducing the influence of the capacitive device applied in clinical tests into the validated model to target the dielectric properties of materials constituting the passive sensor. The use of the neuromodulation device promises observable improvements in motor function among PD patients, including increased limb mobility and greater postural stability.