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1.
J Immunol ; 212(4): 645-662, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38180157

RESUMEN

Collectin is a crucial component of the innate immune system and plays a vital role in the initial line of defense against pathogen infection. In mammals, collectin kidney 1 (CL-K1) is a soluble collectin that has recently been identified to have significant functions in host defense. However, the evolutionary origins of immune defense of CL-K1 and its mechanism in clearance of pathogenic microorganisms remain unclear, especially in early vertebrates. In this study, the Oreochromis niloticus CL-K1 (OnCL-K1) protein was purified and identified, which was capable of binding to two important pathogens of tilapia, Streptococcus agalactiae and Aeromonas hydrophila. Interestingly, OnCL-K1 exhibited direct bactericidal activity by binding to lipoteichoic acid or LPS on cell walls, disrupting the permeability and integrity of the bacterial membrane in vitro. Upon bacterial challenge, OnCL-K1 significantly inhibited the proliferation of pathogenic bacteria, reduced the inflammatory response, and improved the survival of tilapia. Further research revealed that OnCL-K1 could associate with OnMASPs to initiate and regulate the lectin complement pathway. Additionally, OnCD93 reduced the complement-mediated hemolysis by competing with OnMASPs for binding to OnCL-K1. More importantly, OnCL-K1 could facilitate phagocytosis by collaborating with cell surface CD93 in a lectin pathway-independent manner. Moreover, OnCL-K1 also promoted the formation of phagolysosomes, which degraded and killed ingested bacteria. Therefore, this study reveals the antibacterial response mechanism of CL-K1 in primitive vertebrates, including promoting complement activation, enhancing opsonophagocytosis, and killing of macrophages, as well as its internal links, all of which provide (to our knowledge) new insights into the understanding of the evolutionary origins and regulatory roles of the collectins in innate immunity.


Asunto(s)
Macrófagos , Opsonización , Animales , Macrófagos/metabolismo , Activación de Complemento , Riñón/metabolismo , Vertebrados , Colectinas/metabolismo , Proteínas de Peces/metabolismo , Mamíferos/metabolismo
2.
Sensors (Basel) ; 24(4)2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38400403

RESUMEN

To address the lightweight and real-time issues of coal sorting detection, an intelligent detection method for coal and gangue, Our-v8, was proposed based on improved YOLOv8. Images of coal and gangue with different densities under two diverse lighting environments were collected. Then the Laplacian image enhancement algorithm was proposed to improve the training data quality, sharpening contours and boosting feature extraction; the CBAM attention mechanism was introduced to prioritize crucial features, enhancing more accurate feature extraction ability; and the EIOU loss function was added to refine box regression, further improving detection accuracy. The experimental results showed that Our-v8 for detecting coal and gangue in a halogen lamp lighting environment achieved excellent performance with a mean average precision (mAP) of 99.5%, was lightweight with FLOPs of 29.7, Param of 12.8, and a size of only 22.1 MB. Additionally, Our-v8 can provide accurate location information for coal and gangue, making it ideal for real-time coal sorting applications.

3.
Neuroradiology ; 64(7): 1401-1410, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35462573

RESUMEN

BACKGROUND AND OBJECTIVE: Cervical spondylosis (CS) is often accompanied by persistent cervical pain, and psychological complications including depression and anxiety, which aggravate pain. Past studies have revealed brain alterations in chronic pain patients. However, the cortical mechanism for NSAID (non-steroidal anti-inflammatory drug) responders relative to non-responders is still lacking. Therefore, we aimed to investigate the brain functional differences between responders to NSAID relative to non-responders using amplitude of low-frequency fluctuation (ALFF) and dynamic functional connectivity variance (DFCV). To our knowledge, our study is the first to investigate the DFCV in CS patients. MATERIALS AND METHODS: We first explored the differences in psychological inventories in CS patients who respond to NSAID vs non-responders. The voxel-wise ALFF was calculated and compared between CS patients and healthy controls. The ALFF within the resultant clusters were extracted and compared between responders and non-responders. DFCV among the resulting clusters was compared in responders vs non-responders. RESULTS: We found that (1) compared to responders, non-responders exhibited higher levels of anxiety and depression; (2) relative to healthy controls, CS patients exhibited altered ALFF within the middle cingulate cortice (MCC), cerebellum, and middle frontal gyrus (MFG); (3) moreover, compared with responders, non-responders exhibited lower ALFF within MCC; furthermore, non-responders also exhibited increased DFCV between MCC and cerebellum, and between MCC and MFG. CONCLUSION: Our data indicate that psychological comorbidities (e.g., anxiety) influence response to NSAID in CS patients. Relative to NSAID responders, non-responders had altered MCC function, which may be associated with anxiety in CS patients.


Asunto(s)
Imagen por Resonancia Magnética , Espondilosis , Antiinflamatorios , Antiinflamatorios no Esteroideos/uso terapéutico , Encéfalo , Mapeo Encefálico/métodos , Giro del Cíngulo/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética/métodos , Espondilosis/diagnóstico por imagen , Espondilosis/tratamiento farmacológico
4.
Int J Mol Sci ; 23(24)2022 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-36555227

RESUMEN

The complement system is composed of a complex protein network and is pivotal to innate immunity. Complement 3 (C3) is a critical protein in the complement cascade and participates in complement activation and immune defense. In this study, C3 from Nile tilapia (Oreochromis niloticus) was cloned and its function in resisting pathogen infection was characterized. The full length of OnC3 open reading frame is 4974 bp, encoding 1657 aa, and the predicted protein mass weight is 185.93 kDa. The OnC3 amino acid sequence contains macroglobulin domains. The expression pattern of OnC3 mRNA in the tissues of healthy fish was detected, with the highest in the liver and the lowest in the muscle. After challenged with Streptococcus agalactiae and Aeromonas hydrophila, the expression of OnC3 mRNA was significantly up-regulated in the liver, spleen, and head kidney. Further, the recombinant OnC3 protein alleviated the inflammatory response and pathological damage of tissues after infected with S. agalactiae. Moreover, the OnC3 promoted the phagocytosis of monocytes/macrophages to S. agalactiae. The data obtained in this study provide a theoretical reference for in-depth understanding of C3 in host defense against bacterial infection and the immunomodulatory roles in teleost fish.


Asunto(s)
Cíclidos , Enfermedades de los Peces , Infecciones Estreptocócicas , Animales , Complemento C3/genética , Complemento C3/metabolismo , Streptococcus agalactiae , Regulación de la Expresión Génica , Monocitos/metabolismo , Infecciones Estreptocócicas/veterinaria , Proteínas de Peces/metabolismo , Inmunidad Innata/genética , Fagocitosis , Cíclidos/genética , Proteínas Recombinantes/metabolismo , Macrófagos/metabolismo
5.
Int J Mol Sci ; 23(16)2022 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-36012731

RESUMEN

Serum amyloid P component (SAP), an ancient short pentraxin of the pentraxin family, plays an essential role in resistance to bacterial infection. In this study, the expression and functional characterization of SAP (OnSAP) in Nile tilapia (Oreochromis niloticus), a primary vertebrate, are investigated. The open reading frame of OnSAP is 645 bp of a nucleotide sequence encoding a polypeptide of 214 amino acids. As a calcium-binding protein, the structure and relative motif of OnSAP is highly similar to those of humans, containing amino acid residues Asn, Glu, Gln and Asp. In healthy fish, OnSAP mRNA is extensively distributed in all eleven tissues examined, with the highest level in spleen. The mRNA expression of OnSAP was significantly up-regulated after being challenged with gram-positive bacterium Streptococcus agalactiae and gram-negative bacterium Aeromonas hydrophila in vivo. In addition, recombinant OnSAP ((r)OnSAP) protein had capacities of binding S. agalactiae or A. hydrophila in the presence of Ca2+. Further, (r)OnSAP helped monocytes/macrophages to efficiently phagocytize bacteria. Moreover, the (r)OnSAP was able to enhance the complement-mediated lysis of the chicken red blood cells. Collectively, the evidence of SAP in tilapia, based on the results including its evolutionary conserved protein structure, bacterial binding and agglutination, opsonophagocytosis of macrophage and hemolysis enhancement, enriches a better understanding of the biological functions of the pentraxin family.


Asunto(s)
Infecciones Bacterianas , Cíclidos , Enfermedades de los Peces , Componente Amiloide P Sérico , Infecciones Estreptocócicas , Secuencia de Aminoácidos , Animales , Infecciones Bacterianas/metabolismo , Infecciones Bacterianas/veterinaria , Cíclidos/metabolismo , Cíclidos/microbiología , Enfermedades de los Peces/metabolismo , Enfermedades de los Peces/microbiología , Proteínas de Peces/metabolismo , Regulación de la Expresión Génica , Inmunidad Innata/genética , ARN Mensajero , Componente Amiloide P Sérico/metabolismo , Infecciones Estreptocócicas/metabolismo , Streptococcus agalactiae
7.
Heliyon ; 10(5): e26972, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38444489

RESUMEN

Due to the influence of structural clearances, the shearer's oscillates and jumps concerning the scraper are frequent, which induces the collision and vibration impact of the traction components and exacerbates the traction failure of the shearer. Therefore, to explore the correlation between attitude disturbance and traction vibration, an experiment on the traction vibration is carried out, the spatial swaying of the shearer and vibration differences between two traction components are obtained, the influence of the lifting angle of the rocker arm is discussed, and the influence mechanism of the shearer attitude disturbance on traction vibration is elucidated. The results indicate that the rolling swing intensity of the shearer is the highest while the yawing swing intensity is the lowest, and the pitch swing intensity increases with the increase of the lifting angle of the rocker arm. Besides, the vibration impact indices of the two walking mechanisms have a competitive relationship of one decreasing but the other increasing, which can be used as a reference signal to judge the rolling swing and load-sharing performance of the traction part. Moreover, with the swing attitude, the competitive relationship of the average of vibration peaks is shown in the two support shoes, and it can be used as a reference signal to judge the pitching swing and the load-sharing performance of the traction part. This result reveals the impact mechanism of attitude disturbances on traction vibration and proposes a signal monitoring approach for judging the traction attitude disturbance and load-sharing performance, providing a reference for reducing traction faults.

8.
Sci Rep ; 14(1): 8110, 2024 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-38582944

RESUMEN

In view of the problem of poor coupling adaptability and easy rib spalling of coal wall in large mining height comprehensive mining, based on the effective inhibition effect of face guard mechanism on coal wall spalling, the structural characteristics and bearing capacity of different structural forms of the face guard mechanism are compared and analyzed. According to the surrounding rock adaptability of the face guard mechanism, established a numerical analysis model for rigid-flexible coupling of the face guard mechanism under different spalling forms. In order to accurately simulate the stress state of the protective mechanism, a variable stiffness spring damping system is used to replace the hydraulic cylinder. The load-bearing performance and response characteristics of the face guard mechanism under rib spalling coupling conditions were analyzed by applying uniform normal load and impact load to the face guard. The findings indicated that, the integral-type face guard mechanism has a better effect on suppressing rib spalling. When the face guard mechanism bears the static load of the coal wall, the entire response process of the face guard jack can be divided into three stages: initial support, increasing resistance bearing, constant resistance bearing; both the impact load position and the coupling state of the rib spalling will affect the characteristics of force transmission at the face guard mechanism's hinge point, the hinge point between the extensible canopy and the primary face guard is most sensitive to biased load. The research results can provide reference for optimizing the face guard mechanism of large mining height hydraulic support and improving the reliability of coal wall support.

9.
Orthop Rev (Pavia) ; 16: 116374, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38666189

RESUMEN

Osteofascial compartment syndrome is a serious surgical emergency that requires prompt diagnosis and treatment. It presents a challenge for surgeons due to its high disability rate and difficult management. Early fasciotomy decompression is crucial in preventing severe complications. Classic fasciotomy approaches for tibial osteofascial compartment syndrome include double-incision and single-incision techniques.This paper presents a case of a 24-year-old female with bilateral tibial posterior compartment syndrome resulting from prolonged squatting after alcohol intoxication, which is a relatively rare mechanism. We employed an innovative posterior approach to manage the patient with tibial posterior compartment syndrome. Ultimately, we successfully preserved the patient's legs and achieved a good functional recovery.The paper reported a rare case with bilateral posterior tibial compartment syndrome resulting from squatting for 10 hours after alcohol intoxication. The patient achieved favorable outcomes in lower limb function following treatment with a new fasciotomy approach, the posterior approach.The new approach for treating posterior tibial compartment syndrome can serve as a valuable reference for surgeons.

10.
Environ Sci Pollut Res Int ; 31(25): 37746-37756, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38787474

RESUMEN

The selective catalytic oxidation (SCO) is an effective method for removing slipped high-concentration ammonia from NH3-fueled engine exhaust gas. Herein a novel bifunctional catalyst was synthesized by mechanically mixing sulfated Ce/ZrO2 (Ce/ZrO2-S) with a small fraction of Pt/Al2O3 (Pt 0.1 wt.%) for SCO of NH3. As expected, the introduction of a small amount of Pt/Al2O3 significantly improved NH3 conversion ability of Ce/ZrO2-S catalysts toward low-temperature direction. When the mass ratio of Pt/Al2O3 to Ce/ZrO2-S was 7.5% (the corresponding mixed catalyst was denoted as P@CZS-7.5), T90 temperature was 312 °C. More importantly, P@CZS-7.5 catalyst exhibited a much better N2 selectivity (> 96%) in a wide temperature range (320 ~ 450 °C). H2-TPR results revealed that the addition of a trace amount of Pt/Al2O3 significantly led to a distinct shift of reduction temperature peak toward low-temperature direction, thereby greatly improved the low-temperature redox performance of mixed catalysts. Furthermore, NH3-TPD and BET results showed that P@CZS-7.5 catalyst exhibited a similar NH3 adsorption capacity to Ce/ZrO2-S catalyst, while the former had a relatively higher specific surface area than the latter. It was considered as a crucial factor for P@CZS-7.5 catalyst maintaining superior N2 selectivity in high-concentration NH3 (5000 ppm) removal processes. In situ DRIFTS results indicated that P@CZS-7.5 catalyst followed the internal selective catalytic reduction (i-SCR) mechanism in NH3-SCO reactions.


Asunto(s)
Óxido de Aluminio , Amoníaco , Oxidación-Reducción , Amoníaco/química , Catálisis , Óxido de Aluminio/química , Platino (Metal)/química , Circonio/química
11.
ACS Omega ; 9(22): 23451-23461, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38854512

RESUMEN

Previous studies on supercavitation flow have primarily focused on a standing water environment, neglecting the impact of periodic disturbance in a marine environment. Therefore, a series of periodic functions with different frequencies and amplitudes are defined to simulate the periodic disturbance, and a slender projectile is adopted to numerically study the effect of the periodic disturbance on the supercavitation phenomenon in this paper. Research results show that the cavity profile evolves periodically with the periodic disturbance of the external flow field. At the same time, as the frequency and amplitude increase, the minimum cavity shape gradually decreases to the point that the projectile cannot be wholly enveloped, and the maximum cavity profile gradually increases. Furthermore, the relationship between the cavity length (l i ) and the frequency (f) when the cavity cannot envelop the projectile is obtained (l i = -7.381f + 215.384). Meanwhile, the critical frequency range (7.16 ≤ f < 7.96) and amplitude range (1.1 ≤ am < 1.22) of the cavity to envelop the projectile are obtained. The key factors of periodic disturbances on supercavitation flow are revealed in this paper, which provides a theoretical foundation for maintaining supercavitation flow stability in an environment of periodic disturbance flow.

12.
PLoS One ; 19(3): e0299044, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38427649

RESUMEN

Scraper conveyor is the most important transportation equipment in the comprehensive mining equipment, and the chain drive system is its core subsystem, its dynamic characteristics will significantly affect the efficiency of coal transportation in the comprehensive mining face. In this paper, the dynamic characteristics of chain drive system when impacted by falling coal are investigated by means of test. The impact test bench of scraper conveyor was set up to analyze the effects of chain speed, impact height and impact load mass on the dynamic characteristics of the chain drive system of scraper conveyor under the working conditions of unloaded and loaded. The results show that the longitudinal vibration of the scraper conveyor is most obvious when it is impacted by the falling coal, and the chain speed, impact height and impact load mass of the scraper conveyor all play an excitation role on the vibration of the chain drive system, and the vibration of the chain ring is the most intense in the chain drive system, and the loaded coal pile conveyed on the scraper conveyor plays an inhibiting role on the vibration of the chain drive system. This study can help to identify the location where the scraper conveyor fails first in the impact condition, so as to provide a basis for its structural design and improvement, which is of great significance for the stable operation and structural optimization of the scraper conveyor.


Asunto(s)
Carbón Mineral , Minería , Carbón Mineral/análisis , Transportes , Vibración
13.
ScientificWorldJournal ; 2013: 624512, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24302866

RESUMEN

The mechanism of cutting process of roadheader with cutting head was researched, and the influences of properties of coal and rock on cutting load were deeply analyzed. Aimed at the defects of traditional calculation method of cutting load on fully expressing the complex cutting process of cutting head, the method of finite element simulation was proposed to simulate the dynamic cutting process. Aimed at the characteristics of coal and rock which affect the cutting load, several simulations with different firmness coefficient were taken repeatedly, and the relationship between three-axis force and firmness coefficient was derived. A comparative analysis of cutting pick load between simulation results and theoretical formula was carried out, and a consistency was achieved. Then cutting process with a total cutting head was carried out on this basis. The results show that the simulation analysis not only provides a reliable guarantee for the accurate calculation of the cutting head load and improves the efficiency of the cutting head cutting test but also offers a basis for selection of cutting head with different geological conditions of coal or rock.


Asunto(s)
Carbón Mineral/análisis , Minería/instrumentación , Minería/métodos , Suelo/química , Fuerza Compresiva , Diseño de Equipo , Análisis de Falla de Equipo , Dureza , Propiedades de Superficie
14.
ACS Omega ; 8(28): 25221-25235, 2023 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-37483240

RESUMEN

The over-exploitation of resources caused by the increasing coal demand has resulted in a sharp increase in solid waste emissions mainly gangue, which has made the burden on the environment, economy, resources, and society of our country heavier. In order to achieve a balance between energy consumption and solid waste emission in the process of top coal caving, this study carried out coal gangue recognition research based on multi-source time-frequency domain feature fusion (MS-TFDF-F). First, the process of coal gangue symbiosis and the harm of gangue in top coal caving are analyzed, and the fundamental method of comprehensive treatment of gangue is put forward, which is the accurate recognition of the coal gangue interface. Second, by building a top coal caving simulation test bed, the MS signals generated in the caving process of the coal gangue mixture with a gangue content of 0-100% are collected and the TFDFs are extracted. Third, the MS-TFDF-F-based coal gangue recognition model is established. Then, the recognition effect of the two TFDF-F sample sets was compared, and the results show that the time-frequency domain feature selection fusion method (TFDFS-FM) has higher accuracy. On this basis, this paper studies the variation law of the number of sensors on the coal gangue recognition accuracy of MS information fusion. Finally, the economic, social, environmental, and resource benefits of the model are qualitatively described. The final results show that the MS-TFDF-F-based coal gangue recognition model has the strongest recognition ability when fusing six sensor signals, and the recognition accuracy reaches 99% under the AdaBoost algorithm. The establishment of this model brings huge benefits to China's environment, economy, resources, and society, and it is helpful to realize the balance between loss reduction mining and solid waste emission reduction in the process of top coal caving.

15.
ACS Omega ; 8(31): 28592-28607, 2023 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-37576648

RESUMEN

The flow control range of the double-compound axial piston pump with the traditional mechanical-hydraulic feedback servo control is limited and the accuracy is poor. Accordingly, this paper proposes a digital control scheme and its control strategy using a linear stepper motor direct drive servo valve for the precise control and double pumps cooperation of the double-compound axial piston pump. A numerical model of the digital control double-compound axial piston pump is established, and the validity of the model is verified by experimental tests. The performance advantages of the digital control method relative to the mechanical-hydraulic feedback servo control method are analyzed, as is the performance of the control strategy for double pumps. The results show that the digital control method can achieve a wider range of flow control than the traditional mechanical-hydraulic feedback servo control method and avoid the torque impact on the prime mover caused by the active control. The combination of the flow control and the power control including four control modes can meet the performance requirements of the double-compound axial piston pump. The highest priority is given to the energy-saving control, which can reduce the displacement of the main pump in the nonworking state to reduce the additional power loss. The study provides a basis for the accurate matching and optimization of power to load and flow to operating speed of the double-compound axial piston pump.

16.
Adv Sci (Weinh) ; 10(4): e2204977, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36504452

RESUMEN

Compared with the forward design method through the control of geometric parameters and material types, the inverse design method based on the target stress-strain curve is helpful for the discovery of new structures. This study proposes an optimization strategy for mechanical metamaterials based on a genetic algorithm and establishes a topology optimization method for energy-absorbing structures with the desired stress-strain curves. A series of structural mutation algorithms and design-domain-independent mesh generation method are developed to improve the efficiency of finite element analysis and optimization iteration. The algorithm realizes the design of ideal energy-absorbing structures, which are verified by additive manufacturing and experimental characterization. The error between the stress-strain curve of the designed structure and the target curve is less than 5%, and the densification strain reaches 0.6. Furthermore, special attention is paid to passive pedestrian protection and occupant protection, and a reasonable solution is given through the design of a multiplatform energy-absorbing structure. The proposed topology optimization framework provides a new solution path for the elastic-plastic large deformation problem that is unable to be resolved by using classical gradient algorithms or genetic algorithms, and simplifies the design process of energy-absorbing mechanical metamaterials.

17.
J Clin Anesth ; 90: 111211, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37480714

RESUMEN

STUDY OBJECTIVE: The low central venous pressure (LCVP) technique is a key technique in hepatectomy, but its impact on acute kidney injury (AKI) is unclear. The purpose of this study was to explore risk factors (in particular LCVP time) for AKI following hepatectomy. DESIGN: A retrospective case-control study with propensity score matching. SETTING: Operating room. PATIENTS: A total of 1949 patients who underwent hepatectomy were studied. INTERVENTIONS: The patients were grouped with or without AKI within 7 days after surgery. Univariable and multivariable analyses were performed, including recognized intraoperative predictors. The final result is represented as a nomogram. MEASUREMENTS: Preoperative, intraoperative and postoperative data were collected. LCVP is monitored directly through a central venous catheter via the right internal jugular vein. MAIN RESULTS: AKI occurred in 148 patients (7.59%). Surgery time, minimum SBP, furosemide administration and norepinephrine were identified as independent risk factors. The area under the curve for the receiver operating characteristic curves was 0.726 (95% CI 0.668-0.783). CONCLUSION: Intraoperative parameters can be used to predict the probability of postoperative AKI. Although AKI increases the length of stay, it may not increase in-hospital mortality. LCVP time was not confirmed to be a risk factor for AKI.


Asunto(s)
Lesión Renal Aguda , Hepatectomía , Humanos , Puntaje de Propensión , Hepatectomía/efectos adversos , Estudios de Casos y Controles , Nomogramas , Estudios Retrospectivos , Lesión Renal Aguda/diagnóstico , Lesión Renal Aguda/epidemiología , Lesión Renal Aguda/etiología
18.
Sci Rep ; 13(1): 19691, 2023 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-37951963

RESUMEN

The combined rock breaking method with the saw blade and conical pick is proposed to improve the rock breaking efficiency. The numerical simulation of combined rock breaking with the saw blade and conical pick is established to investigate the rock damage mechanism. And verified and modified the numerical simulation model with the rock breaking comprehensive test bench, the quantitative analysis error is less than 0.05, indicated quantitative analysis system is accuracy. The result indicated that the cutting parameters of the saw blade and conical pick affect the rock damage. And the cutting parameters of conical pick and structural parameters of rock plate have been studied to influence rock breaking volume. The research result could help optimize the cutting parameters of the saw blade and conical pick to improve the rock breaking efficiency.

19.
Sci Rep ; 13(1): 13794, 2023 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-37612340

RESUMEN

Top coal caving in fully mechanized caving mining will cause an irregular impact on the caving mechanism of hydraulic support. The vibration response of the caving mechanism varies under different forms of impact. This response difference is a prerequisite for new coal rock identification technology in intelligent mining. Therefore, this work studies the difference in vibration response of the caving mechanism under different forms of impact. An innovative mechanical-hydraulic coupling system model of the caving mechanism impact by coal rock is established. The metal plate impact test proved the significant difference in vibration response of the caving mechanism under coal rock impact of different materials. Afterward, a more improved mechanical-hydraulic co-simulation model analyzed the difference in the vibration response of the caving mechanism under different rock materials, volumes, velocities and impact positions. The results show that the vibration response is more intense under rock impact than under coal impact. A lower position, a faster velocity and a larger volume correspond to a more noticeable response difference in the caving mechanism. The vibration and fault sensitive areas of the caving mechanism are determined. This study has a reference significance for improving the caving mechanism's structural design and failure prevention. The conclusions provide guidance for a new intelligent coal rock identification technology based on vibration signals.

20.
Sci Rep ; 13(1): 8602, 2023 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-37236974

RESUMEN

This paper describes an image processing-based technique used to measure the volume of residual water in the drinking water bottle for the laboratory mouse. This technique uses a camera to capture the bottle's image and then processes the image to calculate the volume of water in the bottle. Firstly, the Grabcut method separates the foreground and background to avoid the influence of background on image feature extraction. Then Canny operator was used to detect the edge of the water bottle and the edge of the liquid surface. The cumulative probability Hough detection identified the water bottle edge line segment and the liquid surface line segment from the edge image. Finally, the spatial coordinate system is constructed, and the length of each line segment on the water bottle is calculated by using plane analytical geometry. Then the volume of water is calculated. By comparing image processing time, the pixel number of liquid level, and other indexes, the optimal illuminance and water bottle color were obtained. The experimental results show that the average deviation rate of this method is less than 5%, which significantly improves the accuracy and efficiency of measurement compared with traditional manual measurement.

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