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Stress tensors and quantification of fracture patterns to analyze connectivity and potential fluid flow in a mesa landform of the Northern Andes
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作者 GARCÍA-ARIAS Sergio VELANDIA Francisco +3 位作者 ALVAREZ Angélica SANABRIA-GÓMEZ JoséD TARAZONA Yessenia VARGAS María Camila 《Journal of Mountain Science》 SCIE CSCD 2024年第1期271-291,共21页
This work applies stress tensors inversions and quantification of fracture patterns along the Mesa de Los Santos, in the Eastern Cordillera of Colombia, to better understand the potential fluid flow. It thus contribut... This work applies stress tensors inversions and quantification of fracture patterns along the Mesa de Los Santos, in the Eastern Cordillera of Colombia, to better understand the potential fluid flow. It thus contributes to the conceptual hydrogeological model. The area was subdivided into three blocks, separated by the NW Potreros and the Los Santos faults, having minor inner faults of different orientations. This separation facilitates the analysis of the fractures measured in the field, which in general show high dip angles and a conjugate geometry in the northern block, tension fractures(Mode I) in the central block, and a random distribution in the southwestern block. WinTensor treatment of slickensides yielded a maximum horizontal stress(SHmax) of 111o, which coincides with the WNW-ESE tensor observed from the conjugate and tension joints. We then used Frac Pa Q to generate interpolation maps of fracture intensity and density. The maps show the highest values in the central block and the lowest in the northern block,where the precipitation is higher, causing intensive rock weathering and homogenization of the fracture planes. Although the highest values of connectivity by line are found to the south of the mesa, we suggest the possibility of greater flow from the recharge zone(NE) along bedding planes and open NW-SE fractures. 展开更多
关键词 Mesa de Los Santos Colombia Win-Tensor FracPaQ strike-slip faults fractured aquifers
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A method to interpret fracture aperture of rock slope using adaptive shape and unmanned aerial vehicle multi-angle nap-of-the-object photogrammetry 被引量:1
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作者 Mingyu Zhao Shengyuan Song +3 位作者 Fengyan Wang Chun Zhu Dianze Liu Sicong Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第3期924-941,共18页
The aperture of natural rock fractures significantly affects the deformation and strength properties of rock masses,as well as the hydrodynamic properties of fractured rock masses.The conventional measurement methods ... The aperture of natural rock fractures significantly affects the deformation and strength properties of rock masses,as well as the hydrodynamic properties of fractured rock masses.The conventional measurement methods are inadequate for collecting data on high-steep rock slopes in complex mountainous regions.This study establishes a high-resolution three-dimensional model of a rock slope using unmanned aerial vehicle(UAV)multi-angle nap-of-the-object photogrammetry to obtain edge feature points of fractures.Fracture opening morphology is characterized using coordinate projection and transformation.Fracture central axis is determined using vertical measuring lines,allowing for the interpretation of aperture of adaptive fracture shape.The feasibility and reliability of the new method are verified at a construction site of a railway in southeast Tibet,China.The study shows that the fracture aperture has a significant interval effect and size effect.The optimal sampling length for fractures is approximately 0.5e1 m,and the optimal aperture interpretation results can be achieved when the measuring line spacing is 1%of the sampling length.Tensile fractures in the study area generally have larger apertures than shear fractures,and their tendency to increase with slope height is also greater than that of shear fractures.The aperture of tensile fractures is generally positively correlated with their trace length,while the correlation between the aperture of shear fractures and their trace length appears to be weak.Fractures of different orientations exhibit certain differences in their distribution of aperture,but generally follow the forms of normal,log-normal,and gamma distributions.This study provides essential data support for rock and slope stability evaluation,which is of significant practical importance. 展开更多
关键词 Unmanned aerial vehicle(UAV) PHOTOGRAMMETRY High-steep rock slope fracture aperture Interval effect Size effect Parameter interpretation
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Using fracture-based continuum modeling of coupled geomechanical-hydrological processes for numerical simulation of hydraulic fracturing
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作者 Goodluck I.Ofoegbu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第5期1582-1599,共18页
This paper describes numerical simulation of hydraulic fracturing using fracture-based continuum modeling(FBCM)of coupled geomechanical-hydrological processes to evaluate a technique for high-density fracturing and fr... This paper describes numerical simulation of hydraulic fracturing using fracture-based continuum modeling(FBCM)of coupled geomechanical-hydrological processes to evaluate a technique for high-density fracturing and fracture caging.The simulations are innovative because of modeling discrete fractures explicitly in continuum analysis.A key advantage of FBCM is that fracture initiation and propagation are modeled explicitly without changing the domain grid(i.e.no re-meshing).Further,multiple realizations of a preexisting fracture distribution can be analyzed using the same domain grid.The simulated hydraulic fracturing technique consists of pressurizing multiple wells simultaneously:initially without permeating fluids into the rock,to seed fractures uniformly and at high density in the wall rock of the wells;followed by fluid injection to propagate the seeded fracture density hydraulically.FBCM combines the ease of continuum modeling with the potential accuracy of modeling discrete fractures and fracturing explicitly.Fractures are modeled as piecewise planar based on intersections with domain elements;fracture geometry stored as continuum properties is used to calculate parameters needed to model individual fractures;and rock behavior is modeled through tensorial aggregation of the behavior of discrete fractures and unfractured rock.Simulations are presented for previously unfractured rock and for rock with preexisting fractures of horizontal,shallow-dipping,steeply dipping,or vertical orientation.Simulations of a single-well model are used to determine the pattern and spacing for a multiple-well design.The results illustrate high-density fracturing and fracture caging through simultaneous fluid injection in multiple wells:for previously unfractured rock or rock with preexisting shallow-dipping or horizontal fractures,and in situ vertical compressive stress greater than horizontal.If preexisting fractures are steeply dipping or vertical,and considering the same in situ stress condition,well pressurization without fluid permeation appears to be the only practical way to induce new fractures and contain fracturing within the target domain. 展开更多
关键词 Discrete fracture fracture-based continuum modeling fracture caging High-density fracturing Hydraulic fracturing Preexisting fracture
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Borehole stability in naturally fractured rocks with drilling mud intrusion and associated fracture strength weakening:A coupled DFN-DEM approach
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作者 Yaoran Wei Yongcun Feng +4 位作者 Zhenlai Tan Tianyu Yang Xiaorong Li Zhiyue Dai Jingen Deng 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第5期1565-1581,共17页
Borehole instability in naturally fractured rocks poses significant challenges to drilling.Drilling mud invades the surrounding formations through natural fractures under the difference between the wellbore pressure(P... Borehole instability in naturally fractured rocks poses significant challenges to drilling.Drilling mud invades the surrounding formations through natural fractures under the difference between the wellbore pressure(P w)and pore pressure(P p)during drilling,which may cause wellbore instability.However,the weakening of fracture strength due to mud intrusion is not considered in most existing borehole stability analyses,which may yield significant errors and misleading predictions.In addition,only limited factors were analyzed,and the fracture distribution was oversimplified.In this paper,the impacts of mud intrusion and associated fracture strength weakening on borehole stability in fractured rocks under both isotropic and anisotropic stress states are investigated using a coupled DEM(distinct element method)and DFN(discrete fracture network)method.It provides estimates of the effect of fracture strength weakening,wellbore pressure,in situ stresses,and sealing efficiency on borehole stability.The results show that mud intrusion and weakening of fracture strength can damage the borehole.This is demonstrated by the large displacement around the borehole,shear displacement on natural fractures,and the generation of fracture at shear limit.Mud intrusion reduces the shear strength of the fracture surface and leads to shear failure,which explains that the increase in mud weight may worsen borehole stability during overbalanced drilling in fractured formations.A higher in situ stress anisotropy exerts a significant influence on the mechanism of shear failure distribution around the wellbore.Moreover,the effect of sealing natural fractures on maintaining borehole stability is verified in this study,and the increase in sealing efficiency reduces the radial invasion distance of drilling mud.This study provides a directly quantitative prediction method of borehole instability in naturally fractured formations,which can consider the discrete fracture network,mud intrusion,and associated weakening of fracture strength.The information provided by the numerical approach(e.g.displacement around the borehole,shear displacement on fracture,and fracture at shear limit)is helpful for managing wellbore stability and designing wellbore-strengthening operations. 展开更多
关键词 Borehole stability Naturally fractured rocks Weakening of fracture strength Discrete fracture network Distinct element method
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Visualization and characterization of experimental hydraulic fractures interacting with karst fracture-cavity distributions
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作者 Hanzhi Yang Xin Chang +4 位作者 Chunhe Yang Wuhao Guo Lei Wang Guokai Zhao Yintong Guo 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第5期1667-1683,共17页
Karst fracture-cavity carbonate reservoirs,in which natural cavities are connected by natural fractures to form cavity clusters in many circumstances,have become significant fields of oil and gas exploration and explo... Karst fracture-cavity carbonate reservoirs,in which natural cavities are connected by natural fractures to form cavity clusters in many circumstances,have become significant fields of oil and gas exploration and exploitation.Proppant fracturing is considered as the best method for exploiting carbonate reservoirs;however,previous studies primarily focused on the effects of individual types of geological formations,such as natural fractures or cavities,on fracture propagation.In this study,true-triaxial physical simulation experiments were systematically performed under four types of stress difference conditions after the accurate prefabrication of four types of different fracture-cavity distributions in artificial samples.Subsequently,the interaction mechanism between the hydraulic fractures and fracture-cavity structures was systematically analyzed in combination with the stress distribution,cross-sectional morphology of the main propagation path,and three-dimensional visualization of the overall fracture network.It was found that the propagation of hydraulic fractures near the cavity was inhibited by the stress concentration surrounding the cavity.In contrast,a natural fracture with a smaller approach angle(0°and 30°)around the cavity can alleviate the stress concentration and significantly facilitate the connection with the cavity.In addition,the hydraulic fracture crossed the natural fracture at the 45°approach angle and bypassed the cavity under higher stress difference conditions.A new stimulation effectiveness evaluation index was established based on the stimulated reservoir area(SRA),tortuosity of the hydraulic fractures(T),and connectivity index(CI)of the cavities.These findings provide new insights into the fracturing design of carbonate reservoirs. 展开更多
关键词 Karst fracture-cavity reservoir fracturing experiment fracture propagation Cross-sectional morphology Stimulation effectiveness
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Fracture geometry and breakdown pressure of radial borehole fracturing in multiple layers
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作者 Yu-Ning Yong Zhao-Quan Guo +3 位作者 Shou-Ceng Tian Lu-Yao Ma Tian-Yu Wang Mao Sheng 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期430-444,共15页
Radial borehole fracturing that combines radial boreholes with hydraulic fracturing is anticipated to improve the output of tight oil and gas reservoirs.This paper aims to investigate fracture propagation and pressure... Radial borehole fracturing that combines radial boreholes with hydraulic fracturing is anticipated to improve the output of tight oil and gas reservoirs.This paper aims to investigate fracture propagation and pressure characteristics of radial borehole fracturing in multiple layers.A series of laboratory experiments with artificial rock samples(395 mm×395 mm×395 mm)was conducted using a true triaxial fracturing device.Three crucial factors corresponding to the vertical distance of adjacent radial borehole layers(vertical distance),the azimuth and diameter of the radial borehole are examined.Experimental results show that radial borehole fracturing in multiple layers generates diverse fracture geometries.Four types of fractures are identified based on the connectivity between hydraulic fractures and radial boreholes.The vertical distance significantly influences fracture propagation perpendicular to the radial borehole axis.An increase in the vertical distance impedes fracture connection across multiple radial borehole layers and reduces the fracture propagation distance along the radial borehole axis.The azimuth also influences fracture propagation along the radial borehole axis.Increasing the azimuth reduces the guiding ability of radial boreholes,which makes the fracture quickly curve to the maximum horizontal stress direction.The breakdown pressure correlates with diverse fracture geometries observed.When the fractures connect multi-layer radial boreholes,increasing the vertical distance decreases the breakdown pressure.Decreasing the azimuth and increasing the diameter also decrease the breakdown pressure.The extrusion force exists between the adjacent fractures generated in radial boreholes in multiple rows,which plays a crucial role in enhancing the guiding ability of radial boreholes and results in higher breakdown pressure.The research provides valuable theoretical insights for the field application of radial borehole fracturing technology in tight oil and gas reservoirs. 展开更多
关键词 Multi-layer radial boreholes Hydraulic fracturing fracture propagation Pressure characteristic
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Management of geriatric acetabular fractures:Contemporary treatment strategies
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作者 Theodoros Tosounidis Byron Chalidis 《World Journal of Clinical Cases》 SCIE 2024年第13期2151-2156,共6页
Acetabular fractures in the geriatric population are typically low-energy fractures resulting from a fall from standing height.Compromised bone quality in the elderly,as well as this population’s concomitant medical ... Acetabular fractures in the geriatric population are typically low-energy fractures resulting from a fall from standing height.Compromised bone quality in the elderly,as well as this population’s concomitant medical comorbidities,render the management of such fractures challenging and controversial.Non-operative management remains the mainstay of treatment,although such a choice is associated with numerous and serious complications related to both the hip joint as well as the general condition of the patient.On the other hand,operatively treating acetabular fractures(e.g.,with osteosynthesis or total hip arthroplasty)is gaining popularity.Osteosynthesis can be performed with open reduction and internal fixation or with minimally invasive techniques.Total hip arthroplasty could be performed either in the acute phase combined with osteosynthesis or as a delayed procedure after a period of non-operative management or after failed osteosynthesis of the acetabulum.Regardless of the implemented treatment,orthogeriatric co-management is considered extremely crucial,and it is currently one of the pillars of a successful outcome after an acetabular fracture. 展开更多
关键词 Acetabular fractures Geriatric fractures fracture fixation Total hip arthroplasty MORTALITY MORBIDITY
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Stress tensor determination by modified hydraulic tests on pre-existing fractures:Method and stress constraints
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作者 Guiyun Gao Chenghu Wang Ke Gao 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第5期1637-1648,共12页
The hydraulic testing of pre-existing fractures(HTPF)is one of the most promising in situ stress measurement methods,particularly for three-dimensional stress tensor determination.However,the stress tensor determinati... The hydraulic testing of pre-existing fractures(HTPF)is one of the most promising in situ stress measurement methods,particularly for three-dimensional stress tensor determination.However,the stress tensor determination based on the HTPF method requires at least six tests or a minimum of 14-15 tests(under different conditions)for reliable results.In this study,we modified the HTPF method by considering the shear stress on each pre-existing fracture,which increased the number of equations for the stress tensor determination and decreased the number of tests required.Different shear stresses were attributed to different fractures by random sampling;therefore,the stress tensors were obtained by searching for the optimal solution using the least squares criterion based on the Monte Carlo method.Thereafter,we constrained the stress tensor based on the tensile strength criterion,compressive strength criterion,and vertical stress constraints.The inverted stress tensors were presented and analyzed based on the tensorial nature of the stress using the Euclidean mean stress tensor.Two stress-measurement campaigns in Weifang(Shandong Province,China)and Mercantour road tunnel(France)were implemented to highlight the validity and efficiency of the modified HTPF(M-HTPF)method.The results showed that the M-HTPF method can be applied for stress tensor inversion using only three to four tests on pre-existing fractures,neglecting the stress gradient.The inversion results were confined to relatively small distribution dispersions and were significantly reliable and stable due to the shear stresses on the fractures and the stress constraints employed.The M-HTPF method is highly feasible and efficient for complete stress tensor determination in a single borehole. 展开更多
关键词 Stress tensor Hydraulic tests on pre-existing fractures Mean stress Stress constraint Hydraulic fracturing
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Epidemiologic investigation of pediatric distal humerus fractures: An American insurance claims database study
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作者 Kyle Jay Klahs Jake E Dertinger +4 位作者 Grant T Mello Kevin Thapa Alexis B Sandler E'Stephan J Jesus Garcia Nata Parnes 《World Journal of Orthopedics》 2024年第1期52-60,共9页
BACKGROUND Distal humerus elbow fractures are one of the most common traumatic fractures seen in pediatric patients and present as three main types:Supracondylar(SC),lateral condyle(LC),and medial epicondyle(ME)fractu... BACKGROUND Distal humerus elbow fractures are one of the most common traumatic fractures seen in pediatric patients and present as three main types:Supracondylar(SC),lateral condyle(LC),and medial epicondyle(ME)fractures.AIM To evaluate the epidemiology of pediatric distal humerus fractures(SC,LC,and ME)from an American insurance claims database.METHODS A retrospective review was performed on patients 17 years and younger with the ICD 9 and 10 codes for SC,LC and ME fractures based on the IBM Truven MarketScan®Commercial and IBM Truven MarketScan Medicare Supplemental databases.Patients from 2015 to 2020 were queried for treatments,patient age,sex,length of hospitalization,and comorbidities.RESULTS A total of 1133 SC,154 LC,and 124 ME fractures were identified.SC fractures had the highest percentage of operation at 83%,followed by LC(78%)and ME fractures(41%).Male patients were,on average,older than female patients for both SC and ME fractures.CONCLUSION In the insurance claims databases used,SC fractures were the most reported,followed by LC fractures,and finally ME fractures.Age was identified to be a factor for how a pediatric distal humerus fractures,with patients with SC and LC fractures being younger than those with ME fractures.The peak age per injury per sex was similar to reported historic central tendencies,despite reported trends for younger physiologic development. 展开更多
关键词 Supracondylar humerus fracture Lateral condyle fracture Medial epicondyle fracture Pediatric elbow Truven Epidemiology
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Blood Calcium as a Protective Factor against Traumatic Fracture
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作者 Xin Zhang Quanquan Zhang +7 位作者 Yinjun Luo Tao Feng Yue Hu Ying Li Wenjing Yu Linghan Guo Jinhua Wang Suchan Liao 《Journal of Biosciences and Medicines》 2024年第3期328-336,共9页
Purpose: This study aims to investigate the predictive value of blood calcium in the prognosis of traumatic fracture. Methods: A retrospective experimental design was employed, 112 cases (52 non-fracture and 60 trauma... Purpose: This study aims to investigate the predictive value of blood calcium in the prognosis of traumatic fracture. Methods: A retrospective experimental design was employed, 112 cases (52 non-fracture and 60 traumatic fracture) were randomly selected. The type of fracture complies with WHO-recommended (2019) diagnostic criteria for osteoporosis combined with fracture. The blood pressure (BP) was measured by OMRON’s HEM-7136 model electronic blood pressure monitor. Blood calcium (Ca<sup>2+</sup>), and blood phosphorus (P) values were measured using Colorimetric Roche kits on a Roche/Hitachi fully automated biochemical analyzer. Data collection and analysis followed. Results: Higher levels of age, systolic and diastolic blood pressures were found in the traumatic fracture group compared to the control group, whereas weight, height, and blood phosphorus did not differ significantly (P adjusting for age, systolic blood pressure, diastolic blood pressure, and blood phosphorus, binary logistic regression analysis revealed that blood calcium was a protective factor against traumatic fracture (β = -26.85, OR = 0.00, 95% CI = 0.00 -0.02, P = 0.022). Conclusion: The findings suggest that high and low blood calcium levels may serve as useful indicators in predicting the prognosis of fractures resulting from trauma. 展开更多
关键词 Traumatic fracture fracture Biochemical Indicators Blood Calcium Prognostic Value
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Management and classification of the fracture of lateral process of talus:An overview and literature update
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作者 Chao-Qun Wang Ulrich Stockle +2 位作者 Sheng-Nan Dong Xu-Gui Li Ze-Xi Ling 《World Journal of Clinical Cases》 SCIE 2024年第15期2487-2498,共12页
Fracture of the lateral process of the talus(FLPT)is uncommon in clinical practice and can be easily missed or misdiagnosed.In recent years,as researchers from all over the world have further deepened their research o... Fracture of the lateral process of the talus(FLPT)is uncommon in clinical practice and can be easily missed or misdiagnosed.In recent years,as researchers from all over the world have further deepened their research on FLPT,there has been a breakthrough in the classification,and the methods and principles of clinical management have changed accordingly;however,there is still no standardized guideline for the diagnosis and management of FLPT,and there have been few relevant literature review articles related to this kind of fracture in the past at least 5 years.In this article,we review the clinical classification,classification-based therapeutic recommendations,and prognosis of FLPT,with the aim of providing a reference for the clinical diagnosis and management of this infrequent fracture. 展开更多
关键词 fracture of the lateral process of the talus fracture of the talus Hindfoot injuries Intraarticular fracture Subtalar joint
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Clinical outcomes of triceps reflecting anconeus pedicle and olecranon osteotomy approach for distal humerus intercondylar fractures
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作者 Rohit Ailani Sanjeev Kumar Bhuyan +2 位作者 Brejesh Kumar Prasad Amit Kumar Namrata Dawani 《World Journal of Orthopedics》 2024年第6期570-577,共8页
BACKGROUND The preferred treatment for distal humeral intercondylar fractures is open reduction and internal fixation.While there is consensus about the posterior approach,several posterior approaches have been develo... BACKGROUND The preferred treatment for distal humeral intercondylar fractures is open reduction and internal fixation.While there is consensus about the posterior approach,several posterior approaches have been developed.It is debatable as to which approach is best.AIM To compare triceps reflecting anconeus pedicle(TRAP)and olecranon osteotomy approaches for internal fixation of distal humeral intercondylar fracture.METHODS In total,40 cases of Arbeitsgemeinschaft für Osteosynthesefragen/Association of the Study of Internal Fixation type C,closed,and Gustilo type I intercondylar humeral fractures were included.Patients ranged in age from 18 years to 70 years.The patients were randomized into two groups:TRAP group and olecranon osteotomy group,with 20 cases in each.All were followed up at 6 wk,3 months,6 months,and 12 months.Functional outcomes were measured in terms of flexion-extension arc,Disabilities of Arm,Shoulder and Hand score,and Mayo Elbow Performance Score.RESULTS The mean age was 43.2 years in the TRAP group and 37.5 years in the olecranon osteotomy group.The mean operative time and mean duration of hospital stay in the TRAP group were significantly higher than in the olecranon osteotomy group(119.5 vs 111.5 min and 9.85 vs 5.45 d,respectively).The mean arc of flexion-extension,Disabilities of Arm,Shoulder and Hand score,and Mayo Elbow Performance Score were comparable without any significant difference in the groups at the 12-month follow-up(107.0 vs 106.2,18.3 vs 15.7,and 84.2 vs 86.2,respectively).Ulnar paresthesia and superficial infections were comparable in both groups(2 cases vs 3 cases and 3 cases vs 2 cases,respectively).Hardware prominence was significantly higher in the olecranon osteotomy group,mostly due to tension band wiring.CONCLUSION Both approaches were equivalent,but there is a need for further study including higher numbers of subjects and longer study duration to prove the benefits of one approach over the other. 展开更多
关键词 Elbow joint Humeral fracture OSTEOTOMY INTERNAL fracture fixation
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Creep constitutive model considering nonlinear creep degradation of fractured rock
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作者 Wang Chunping Liu Jianfeng +3 位作者 Chen Liang Liu Jian Wang Lu Liao Yilin 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第1期105-116,共12页
Stability analysis of underground constructions requires a model study of rock masses’ long-term performance. Creep tests under different stress conditions was conducted on intact granite and granite samples fracture... Stability analysis of underground constructions requires a model study of rock masses’ long-term performance. Creep tests under different stress conditions was conducted on intact granite and granite samples fractured at 30° and 45° angles. The experimental results indicate that the steady creep strain rates of intact and fractured rock present an exponential increase trend with the increase of stress level. A nonlinear creep model is developed based on the experimental results, in which the initial damage caused by fracture together with the damage caused by constant load have been taken into consideration. The fitting analysis results indicated that the model proposed is more accurate at identifying the full creep regions in fractured granite, especially the accelerated stage of creep deformation. The least-square fit error of the proposed creep model is significantly lower than that of Nishihara model by almost an order of magnitude. An analysis of the effects of elastic modulus, viscosity coefficient, and damage factors on fractured rock strain rate and creep strain is conducted. If no consideration is given to the effects of the damage, the proposed nonlinear creep model can degenerate into to the classical Nishihara model. 展开更多
关键词 fractured rock DAMAGE CREEP Beishan granite Geological disposal
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Factors Influencing Fracture Propagation in Collaborative Fracturing ofMultiple HorizontalWells
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作者 Diguang Gong Junbin Chen +1 位作者 Cheng Cheng Yuanyuan Kou 《Energy Engineering》 EI 2024年第2期425-437,共13页
Horizontal well-stimulation is the key to unconventional resource exploration and development.The development mode of the well plant helps increase the stimulated reservoir volume.Nevertheless,fracture interference be... Horizontal well-stimulation is the key to unconventional resource exploration and development.The development mode of the well plant helps increase the stimulated reservoir volume.Nevertheless,fracture interference between wells reduces the fracturing effect.Here,a 2D hydro-mechanical coupling model describing hydraulic fracture(HF)propagation is established with the extended finite element method,and the effects of several factors on HF propagation during multiple wells fracturing are analyzed.The results show that with an increase in elastic modulus,horizontal principal stress difference and injection fluid displacement,the total fracture area and the reservoir stimulation efficiency are both improved in all three fracturing technologies.After a comparison of the three technologies,the method of improved zipper fracturing is proposed,which avoids mutual interference between HFs,and the reservoir stimulation effect is improved significantly.The study provides guidance for optimizing the fracturing technology of multiple horizontal wells. 展开更多
关键词 Multi-well fracturing inter-fracture interference hydraulic fracturing hydro-mechanical coupling extended finite element horizontal well
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Rare Bilateral Radius and Ulna Fractures: A Case Report
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作者 Kwabena Nana Achiaw Dankwa Ekins Kuuzie Samuel Kwame Ofori 《Open Journal of Orthopedics》 2024年第1期1-11,共11页
Introduction: Forearm fractures involving both the radius and ulna, present distinctive challenges in orthopedic trauma management. This case report explores the complexities of a rare case of bilateral fractures, emp... Introduction: Forearm fractures involving both the radius and ulna, present distinctive challenges in orthopedic trauma management. This case report explores the complexities of a rare case of bilateral fractures, emphasizing the importance of a comprehensive approach for optimal outcomes. Case Presentation: This report presents the case of a 40-year-old motorcyclist who was involved in a road accident and arrived at the emergency department shortly after the incident. Clinical examination revealed closed fractures in both forearms with mild swelling and severe tenderness. Fortunately, no neurovascular issues or compartment syndrome were detected. The patient was administered intravenous fluids and effective pain relief. Forearm splints were applied and the arms were elevated using pillows. Radiographs showed fractures in the right distal radius and ulna, as well as the left mid-shaft radius and ulna. Under general anesthesia, open reduction and internal fixation were per-formed using plates and screws for all four fractures. Postoperatively, the patient’s arms were immobilized and elevated, with gradual recovery during follow-up appointments over six months, eventually achieving full function without complaints. Conclusion: This article highlights the possibility, although infrequent, of bilateral shaft fractures of the ulna and radius. With thorough clinical assessment and radiological investigation, such fractures can be well-defined. The required definitive treatment, which usually involves open reduction and internal fixation, can be performed. 展开更多
关键词 FOREARM fracture ULNAR RADIUS BILATERAL
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A Comparative Study of Mandibular Fractures in Senegal: Children vs. Adults
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作者 Paul Niang 《Open Journal of Stomatology》 2024年第2期72-76,共5页
Introduction: The commonest maxillofacial fractures involve the mandible. Age can be considered among influential factors. Aim of the Study: To compare mandibular fractures between children and adults from the beginni... Introduction: The commonest maxillofacial fractures involve the mandible. Age can be considered among influential factors. Aim of the Study: To compare mandibular fractures between children and adults from the beginning up to the treatment in Senegal. Patients and Method: A three-year retrospective study was conducted in a university hospital. The medical records of patients admitted for maxillofacial injuries were reviewed. Patient and injury-related variables including age, gender, etiology, average consultation delay, anatomic location of fracture and treatment were compared up to age of 15 and beyond that. Results: Considering 272 casualties, maxillofacial fractures were less frequent among children than adults (36.7% and 59.7%) and were mainly mandibular (90.1% and 91.4%). Male predilection (sex ratio of 2.4 and 4.9) was twice (2) as pronounced from the age of 16. The average consultation delay was two (2) times shorter for children. Road traffic accidents which predominated among children (33.9%) had comparable frequency (32.3%) although they were outnumbered by assault (37.6%) among adults. Fractures occurred mainly on the corpus (90.1% and 90.4%), particularly on parasymphysis (40.1%) up to the age of 15, whereas angle fractures increased (8.5% to 19.6%) and joint damage decreased afterwards. Intra-oral orthopedic procedures (91.2% and 92.6%) in which mandibular retention splints were more common (37.3%) up to the age of 15 then arch ligatures (49%) were then widely favored. Conclusion: Differences relating to the distribution of causes but also to the anatomic location on the corpus and to the choice of intra-oral orthopedic procedures within overall similarities between children and adults regarding the male predilection, the frequency of road traffic accidents, the mandibular injuries, but also the school therapeutic attitude consisting of favoring the orthopedic option. 展开更多
关键词 fracture MANDIBLE CHILD ADULT
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Modeling the Interaction between Vacancies and Grain Boundaries during Ductile Fracture
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作者 Mingjian Li Ping Yang Pengyang Zhao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期2019-2034,共16页
The experimental results in previous studies have indicated that during the ductile fracture of pure metals,vacancies aggregate and form voids at grain boundaries.However,the physical mechanism underlying this phenome... The experimental results in previous studies have indicated that during the ductile fracture of pure metals,vacancies aggregate and form voids at grain boundaries.However,the physical mechanism underlying this phenomenon remains not fully understood.This study derives the equilibrium distribution of vacancies analytically by following thermodynamics and the micromechanics of crystal defects.This derivation suggests that vacancies cluster in regions under hydrostatic compression to minimize the elastic strain energy.Subsequently,a finite element model is developed for examining more general scenarios of interaction between vacancies and grain boundaries.This model is first verified and validated through comparison with some available analytical solutions,demonstrating consistency between finite element simulation results and analytical solutions within a specified numerical accuracy.A systematic numerical study is then conducted to investigate the mechanism that might govern the micromechanical interaction between grain boundaries and the profuse vacancies typically generated during plastic deformation.The simulation results indicate that the reduction in total elastic strain energy can indeed drive vacancies toward grain boundaries,potentially facilitating void nucleation in ductile fracture. 展开更多
关键词 Ductile fracture VACANCY grain boundary MICROMECHANICAL finite element method
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A phase-field model for simulating the propagation behavior of mixed-mode cracks during the hydraulic fracturing process in fractured reservoirs
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作者 Dan ZHANG Liangping YI +4 位作者 Zhaozhong YANG Jingqiang ZHANG Gang CHEN Ruoyu YANG Xiaogang LI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第5期911-930,共20页
A novel phase-field model for the propagation of mixed-mode hydraulic fractures,characterized by the formation of mixed-mode fractures due to the interactions between fluids and solids,is proposed.In this model,the dr... A novel phase-field model for the propagation of mixed-mode hydraulic fractures,characterized by the formation of mixed-mode fractures due to the interactions between fluids and solids,is proposed.In this model,the driving force for the phase field consists of both tensile and shear components,with the fluid contribution primarily manifesting in the tension driving force.The displacement and pressure are solved simultaneously by an implicit method.The numerical solution's iterative format is established by the finite element discretization and Newton-Raphson(NR)iterative methods.The correctness of the model is verified through the uniaxial compression physical experiments on fluid-pressurized rocks,and the limitations of the hydraulic fracture expansion phase-field model,which only considers mode I fractures,are revealed.In addition,the influence of matrix mode II fracture toughness value,natural fracture mode II toughness value,and fracturing fluid injection rate on the hydraulic fracture propagation in porous media with natural fractures is studied. 展开更多
关键词 mixed-mode crack hydraulic fracturing poro-elasticity phase-field method(PFM)
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Effect of navigation endoscopy combined with threedimensional printing technology in the treatment of orbital blowout fractures
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作者 Jin-Hai Yu Yao-Hua Wang +3 位作者 Qi-Hua Xu Chao Xiong An-An Wang Hong-Fei Liao 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第3期570-576,共7页
●AIM:To explore the combined application of surgical navigation nasal endoscopy(NNE)and three-dimensional printing technology(3DPT)for the adjunctive treatment of orbital blowout fractures(OBF).●METHODS:Retrospectiv... ●AIM:To explore the combined application of surgical navigation nasal endoscopy(NNE)and three-dimensional printing technology(3DPT)for the adjunctive treatment of orbital blowout fractures(OBF).●METHODS:Retrospective analysis was conducted on the data of patients with OBF who underwent surgical treatment at the Affiliated Eye Hospital of Nanchang University between July 2012 and November 2022.The control group consisted of patients who received traditional surgical treatment(n=43),while the new surgical group(n=52)consisted of patients who received NNE with 3DPT.The difference in therapeutic effects between the two groups was evaluated by comparing the duration of the operation,best corrected visual acuity(BCVA),enophthalmos difference,recovery rate of eye movement disorder,recovery rate of diplopia,and incidence of postoperative complications.●RESULTS:The study included 95 cases(95 eyes),with 63 men and 32 women.The patients’age ranged from 5 to 67y(35.21±15.75y).The new surgical group and the control group exhibited no statistically significant differences in the duration of the operation,BCVA and enophthalmos difference.The recovery rates of diplopia in the new surgical group were significantly higher than those in the control group at 1mo[OR=0.03,95%CI(0.01–0.15),P<0.0000]and 3mo[OR=0.11,95%CI(0.03–0.36),P<0.0000]postoperation.Additionally,the recovery rates of eye movement disorders at 1 and 3mo after surgery were OR=0.08,95%CI(0.03–0.24),P<0.0000;and OR=0.01,95%CI(0.00–0.18),P<0.0000.The incidence of postoperative complications was lower in the new surgical group compared to the control group[OR=4.86,95%CI(0.95–24.78),P<0.05].●CONCLUSION:The combination of NNE and 3DPT can shorten the recovery time of diplopia and eye movement disorder in patients with OBF. 展开更多
关键词 orbital blowout fracture three-dimensional printing ENDOSCOPY surgical navigation
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Systemic modulation of skeletal mineralization by magnesium implant promoting fracture healing: Radiological exploration enhanced with PCA-based machine learning in a rat femoral model
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作者 Yu Sun Heike Helmholz Regine Willumeit-Römer 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第3期1009-1020,共12页
The clinical application of magnesium(Mg)and its alloys for bone fractures has been well supported by in vitro and in vivo trials.However,there were studies indicating negative effects of high dose Mg intake and susta... The clinical application of magnesium(Mg)and its alloys for bone fractures has been well supported by in vitro and in vivo trials.However,there were studies indicating negative effects of high dose Mg intake and sustained local release of Mg ions on bone metabolism or repair,which should not be ignored when developing Mg-based implants.Thus,it remains necessary to assess the biological effects of Mg implants in animal models relevant to clinical treatment modalities.The primary purpose of this study was to validate the beneficial effects of intramedullary Mg implants on the healing outcome of femoral fractures in a modified rat model.In addition,the mineralization parameters at multiple anatomical sites were evaluated,to investigate their association with healing outcome and potential clinical applications.Compared to the control group without Mg implantation,postoperative imaging at week 12 demonstrated better healing outcomes in the Mg group,with more stable unions in 3D analysis and high-mineralized bridging in 2D evaluation.The bone tissue mineral density(TMD)was higher in the Mg group at the non-operated femur and lumbar vertebra,while no differences between groups were identified regarding the bone tissue volume(TV),TMD and bone mineral content(BMC)in humerus.In the surgical femur,the Mg group presented higher TMD,but lower TV and BMC in the distal metaphyseal region,as well as reduced BMC at the osteotomy site.Principal component analysis(PCA)-based machine learning revealed that by selecting clinically relevant parameters,radiological markers could be constructed for differentiation of healing outcomes,with better performance than 2D scoring.The study provides insights and preclinical evidence for the rational investigation of bioactive materials,the identification of potential adverse effects,and the promotion of diagnostic capabilities for fracture healing. 展开更多
关键词 MAGNESIUM Implants Bone fracture MINERALIZATION Systemic modulation Principal component analysis.
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