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With the continuous increase of mining in depth, the gas extraction faces the challenges of low permeability, great ground stress, high temperature and large gas pressure in coal seam. The controllable shock wave (CSW), as a new method for enhancing permeability of coal seam to improve gas extraction, features in the advantages of high efficiency, eco-friendly, and low cost. In order to better utilize the CSW into gas extraction in coal mine, the mechanism and feasibility of CSW enhanced extraction need to be studied. In this paper, the basic principles, the experimental tests, the mathematical models, and the on-site tests of CSW fracturing coal seams are reviewed, thereby its future research directions are provided. Based on the different media between electrodes, the CSW can be divided into three categories: hydraulic effect, wire explosion and excitation of energetic materials by detonating wire. During the process of propagation and attenuation of the high-energy shock wave in coal, the shock wave and bubble pulsation work together to produce an enhanced permeability effect on the coal seam. The stronger the strength of the CSW is, the more cracks created in the coal is, and the greater the length, width and area of the cracks being. The repeated shock on the coal seam is conducive to the formation of complex network fracture system as well as the reduction of coal seam strength, but excessive shock frequency will also damage the coal structure, resulting in the limited effect of the enhanced gas extraction. Under the influence of ground stress, the crack propagation in coal seam will be restrained. The difference of horizontal principal stress has a significant impact on the shape, propagation direction and connectivity of the CSW induced cracks. The permeability enhancement effect of CSW is affected by the breakage degree of coal seam. The shock wave is absorbed by the broken coal, which may hinder the propagation of CSW, resulting in a poor effect of permeability enhancement. When arranging two adjacent boreholes for CSW permeability enhancement test, the spacing of boreholes should not be too close, which may lead to negative pressure mutual pulling in the early stage of drainage. At present, the accurate method for effectively predicting the CSW permeability enhanced range should be further investigated.

Oral fluid (OF) enables non-invasive sample collection for on-site drug testing, but performance of on-site tests with occasional and frequent smokers’ OF to identify cannabinoid intake requires further evaluation. Furthermore, as far as we are aware, no studies have evaluated differences between cannabinoid disposition among OF collection devices with authentic OF samples after controlled cannabis administration. Fourteen frequent (≥4 times per week) and 10 occasional (less than twice a week) adult cannabis smokers smoked one 6.8 % ∆ 9 -tetrahydrocannabinol (THC) cigarette ad libitum over 10 min. OF was collected with the StatSure Saliva Sampler, Oral-Eze, and Draeger DrugTest 5000 test cassette before and up to 30 h after cannabis smoking. Test cassettes were analyzed within 15 min and gas chromatography–mass spectrometry cannabinoid results were obtained within 24 h. Cannabinoid concentrations with the StatSure and Oral-Eze devices were compared and times of last cannabinoid detection ( t last ) and DrugTest 5000 test performance were assessed for different cannabinoid cutoffs. 11- nor -9-Carboxy-THC (THCCOOH) and cannabinol concentrations were significantly higher in Oral-Eze samples than in Stat-Sure samples. DrugTest 5000 t last for a positive cannabinoid test were median (range) 12 h (4–24 h) and 21 h (1– ≥ 30 h) for occasional and frequent smokers, respectively. Detection windows in screening and confirmatory tests were usually shorter for occasional than for frequent smokers, especially when including THCCOOH ≥20 ng L −1 in confirmation criteria. No differences in t last were observed between collection devices, except for THC ≥2 μg L −1 . We thus report significantly different THCCOOH and cannabinol, but not THC, concentrations between OF collection devices, which may affect OF data interpretation. The DrugTest 5000 on-site device had high diagnostic sensitivity, specificity, and efficiency for cannabinoids.

One of the major classes of mycotoxins posing serious hazards to humans and animals and potentially causing severe economic impact to the cereal industry are the trichothecenes, produced by many fungal genera. As such, indicative limits for the sum of T-2 and HT-2 were introduced in the European Union in 2013 and discussions are ongoing as to the establishment of maximum levels. This review provides a concise assessment of the existing understanding concerning the toxicological effects of T-2 and HT-2 in humans and animals, their biosynthetic pathways, occurrence, impact of climate change on their production and an evaluation of the analytical methods applied to their detection. This study highlights that the ecology of F. sporotrichioides and F. langsethiae as well as the influence of interacting environmental factors on their growth and activation of biosynthetic genes are still not fully understood. Predictive models of Fusarium growth and subsequent mycotoxin production would be beneficial in predicting the risk of contamination and thus aid early mitigation. With the likelihood of regulatory maximum limits being introduced, increased surveillance using rapid, on-site tests in addition to confirmatory methods will be required. allowing the industry to be proactive rather than reactive.

Background Infection with Trichomonas vaginalis can lead to cervicitis, urethritis, pelvic inflammatory disease, prostatitis and perinatal complications and increased risk of HIV transmission. Here, we used an RPA-based CRISPR-Cas12a assay system in combination with a lateral flow strip (LFS) (referred to as RPA-CRISPR-Cas12a) to establish a highly sensitive and field-ready assay and evaluated its ability to detect clinical samples. Methods We developed a one-pot CRISPR-Cas12a combined with RPA-based field detection technology for T. vaginalis , chose actin as the target gene to design crRNA and designed RPA primers based on the crRNA binding site. The specificity of the method was demonstrated by detecting genomes from nine pathogens. To improve the usability and visualize the RPA-CRISPR-Cas12a assay results, both fluorescence detection and LFS readouts were devised. Results The RPA-CRISPR-Cas12a assay platform was completed within 60 min and had a maximum detection limit of 1 copy/µl and no cross-reactivity with Candida albicans , Mycoplasma hominis , Neisseria gonorrhoeae , Escherichia coli , Cryptosporidium parvum , G. duodenalis or Toxoplasma gondii after specificity validation. Thirty human vaginal secretions were tested by RPA-CRISPR-Cas12a assays, and the results were read by a fluorescent reporter and LFS biosensors and then compared to the results from nested PCR detection of these samples. Both RPA-CRISPR-Cas12a assays showed 26.7% (8/30) T. vaginalis -positive samples and a consistency of 100% (8/8). The RPA-CRISPR-Cas12a assays had a higher sensitivity than nested PCR (only seven T. vaginalis -positive samples were detected). Conclusions The T. vaginalis RPA-CRISPR-Cas12a assay platform in this study can be used for large-scale field testing and on-site tests without the need for trained technicians or costly ancillary equipment. Graphical abstract

We present the design for the first narrowband filter, NB964, for the Dark Energy Camera (DECam), which is operated on the 4-m Blanco Telescope at the Cerro Tololo Inter-American Observatory. The NB964 filter profile is essentially defined by maximizing the power of searching for Lyman-alpha emitting galaxies (LAEs) in the epoch of reionization, with the consideration of the night sky background in the near-infrared and the DECam quantum efficiency. The NB964 filter was manufactured by Materion in 2015. It has a central wavelength of 964.2 nm and a full width at half maximum (FWHM) of 9.2 nm. An NB964 survey named Lyman Alpha Galaxies in the Epoch of Reionization (LAGER) has been ongoing since December 2015. Here, we report results of lab tests, on-site tests, and observations with the NB964 filter. The excellent performances of this filter ensure that the LAGER project is able to detect LAEs at z ∼ 7 with a high efficiency.

This paper investigates airflow parameters for a pumped storage power station in Shandong. Continuous measurement was conducted for air temperature and humidity parameters at a height of 1.5m in the generator floor during summer. During test, three units operated and a supply air volume of 150,000 m 3 /h with 20.5°C and 90% RH was sent to generator floor. The results indicate that air parameters upstream and downstream of the generator floor satisfied the requirements of ≤30°C and ≤75%RH. Since the air temperature in the generator floor consistently remained below 24°C, which was significantly lower than the specified values, it is necessary to implement energy-saving control strategies for the air conditioning system to reduce operational energy consumption. The findings could provide reference for the energy-efficient design of the ventilation and air conditioning system in the main plant.

Ensuring safety in geotechnical engineering has consistently posed challenges due to the inherent variability of soil. In the case of slope stability problems, performing on-site tests is both costly and time-intensive due to the need for sophisticated equipment (to acquire and move) and logistics. Consequently, the analysis of simulation models based on soft computing proves to be a practical and invaluable alternative. In this research work, learning abilities of the Class Noise Two (CN2), Stochastic Gradient Descent (SGD), Group Method of Data Handling (GMDH) and artificial neural network (ANN) have been investigated in the prediction of the factor of safety (FOS) of slopes. This has been successfully done through literature search, data curation and data sorting. A total of three hundred and forty-nine (349) data entries on the FOS of slopes were collected from literature and sorted to remove odd values and unlogic results, which had been used together in a previous research work. After the sorting process, the remainder of the realistic data entries was 296. The previous work which had included unrealistic data entries had unit weight, γ (kN/m 3 ), cohesion, C (kPa),angle of internal friction (Φ°), slope angle ( °), slope height H (m), and pore water pressure ratio, r u as the studied parameters, which formed the independent variables. After careful checks, the initial results showed poor correlation with the individual factors and the factors were collected into three non-dimensional parameters based on the understanding of the physics of flows, which are: C/γ.h-Cohesion/unit weight x slope height, tan(ϕ)/tan(β)-the tangent of internal friction angle/Tangent of slope angle, and ρ/γ.h-Water pressure/unit weight x slope height, which are deployed as inputs and FOS-the safety factor of the slope as the output. At the end of the exercise, the ANN outclassed the other techniques with SSE of 62%, MAE of 0.27, MSE of 0.21, RMSE of 0.46, average total error of 24%, and R 2 of 0.946 thereby becoming the decisive intelligent model in this exercise. However, there is an advantage the deployment of GMDH, which comes second in order of superiority, has over the ANN. This is the development of a closed-form equation that allows its model to be applied manually in the design of slope stability problems. Overall, the present research models outperformed the eleven (11) models of the previous work due to sorting and elimination of unrealistic data entries deposited in the literature, the application of dimensionless combination of the studied slope stability parameters and the superiority of the selected machine learning techniques.

Given the shortage of surface water supplies caused by the construction of dams in the upstream countries of the Tigris River, which has reduced Iraq’s share of water, the increasing demand for water, and climate change, groundwater has emerged as a critical and essential water resource. This study aims to find the infiltration capacity and salinization of groundwater in the unconfined aquifer relationship and sustainable remediation of aquifer storage in the north Baghdad Ishaqi area of central Iraq in 2024. GIS and Surfer software were used. Ten soil and groundwater samples were extracted from sites randomly distributed throughout the area of 410 km 2 , with 10 double-ring infiltrometer tests being conducted at the same sites. The results of the on-site tests revealed that the central part of the area was characterized by coarse-grained soil, higher infiltration capacity, and higher groundwater concentrations, which ranged between 70–82%, 87–183 mm/hr., and 2,050–4,200 m/L, respectively. The opposite was the case in the northern and southern parts of the area. The desalination process of the Ishaqi aquifer requires a double injection of water with pumping rates of 1, 2, 3, 4, and 5 m 3 /s of water to reduce salinity from 4,500 to 500 mg/L of 108 m³ aquifer volume for periods of 8,800, 4,620, 3,140, 2,360, and 1,780 days, respectively. These periods were greatly reduced when the outflow rate became twice the inflow rate. The mitigation equation was derived from basic assumptions of enclosed aquifer and homogenous mixing. A good coincidence between theoretical and measured concentrations was obtained. The study concluded that there is a direct mathematical relationship between aquifer salination and deep filtration with a correlation factor of 0.998, which led to high total dissolved solids (TDS) accumulations in the groundwater. The desalination process is possible and requires 2–10 years depending on pumping rates. The saline aquifer mitigation procedure is a successful and beneficial long-term tool.

Coal seam water injection is widely used to prevent rockbursts in coal mines, and the duration of water injection is an important parameter related to the effectiveness of rockburst prevention, making it of practical importance to optimize the effective water injection duration. This paper presents the test results of the mechanical properties and pore structure of samples with different soaking time, obtained from a working face where rockburst occurred. Soaking time changes the mechanical properties of samples, and this time effect differs with the coal size (from centimeter to nanometer size). Results of numerical simulation and on-site tests in the Changgouyu coal mine demonstrated that water injection can effectively soften coal bodies and release or transfer stresses, and the time effect of water injection on rock prevention and control is apparent.

In used reinforced concrete grain silos, failures occur (e.g., increased cracking of reinforced concrete walls). These failures may be caused by overloading of the chamber structure due to a sudden drop in ambient temperature throughout the day. These daily drops in ambient temperature cause thermal stresses in the silo shell. Additional thermal stresses in the silo are caused by the interaction of the wall and the bulk material stored within the silo. This results in additional tensile stresses in the cross-sections of the silo chamber wall, combined with bending. This paper presents the results of in situ studies of early winter temperature field distributions in a grain elevator at the Podlaskie Grain Plant in Białystok. A specialized prototype SensoNet telemetry system was used for the on-site tests, enabling continuous monitoring of operating silo batteries and recording physical quantities such as deformation and temperature. The measured variable temperature fields on the surface of the silo chambers were used to determine nonlinear temperature distributions across the thickness of the reinforced concrete walls in the grain silo battery using the finite difference method. Numerical calculations of four interlocking grain silos subjected to static (Janssen pressure of bulk material) and thermal loads were performed using the finite element method. Analysis of the numerical calculation results (FEM) demonstrates the unfavorable effects of thermal and static load coupling in the form of increases in latitudinal tensile stresses and bending moments in the reinforced concrete walls of the grain silo batteries.