Search Results (64)

In comparison to shallow coal seams, deep coal seams exhibit characteristics of high temperature, pressure, and in-situ stress, leading to significant differences in reservoir properties that constrain the effective development of deep coalbed methane (CBM). This study takes the Carboniferous deep 8# coal seam in the Yulin area of Ordos basin as the research subject. Based on the test results from core drilling wells, a comprehensive analysis of the characteristics and variation patterns of coal reservoir properties and a comparative analysis of the exploration and development potential of deep CBM are conducted, aiming to provide guidance for the development of deep CBM in the Ordos basin. The research results indicate that the coal seams are primarily composed of primary structure coal, with semi-bright to bright being the dominant macroscopic coal types. The maximum vitrinite reflectance (R_o,max) ranges between 1.99% and 2.24%, the organic is type III, and the high Vitrinite content provides a substantial material basis for the generation of CBM. Longitudinally, influenced by sedimentary environment and plant types, the lower part of the coal seam exhibits higher Vitrinite content and fixed carbon (FC_ad). The pore morphology is mainly characterized by wedge-shaped/parallel plate-shaped pores and open ventilation pores, with good connectivity, which is favorable for the storage and output of CBM. Micropores (<2 nm) have the highest volume proportion, showing an increasing trend with burial depth, and due to interlayer sliding and capillary condensation, the pore size (<2 nm) distribution follows an N shape. The full-scale pore heterogeneity (fractal dimension) gradually increases with increasing buried depth. Macroscopic fractures are mostly found in bright coal bands, while microscopic fractures are more developed in Vitrinite, showing a positive correlation between fracture density and Vitrinite content. The porosity and permeability conditions of reservoirs are comparable to the Daning–Jixian block, mostly constituting oversaturated gas reservoirs with a critical depth of 2400–2600 m and a high proportion of free gas, exhibiting promising development prospects, and the middle and upper coal seams are favorable intervals. In terms of resource conditions, preservation conditions, and reservoir alterability, the development potential of CBM from the Carboniferous deep 8# coal seam is comparable to the Linxing block but inferior to the Daning–Jixian block and Baijiahai uplift. Full article

This study presents a digital twin–based framework for assessing rockfall hazards at the immediate vicinity of the Rumkale Archaeological Site, a geologically sensitive and culturally significant location in southeastern Türkiye. Historically associated with early Christianity and strategically located along the Euphrates, Rumkale is a protected heritage site that attracts increasing numbers of visitors. Here, high-resolution photogrammetric models were generated using imagery acquired from a remotely piloted aircraft system and post-processed with ground control points to produce a spatially accurate 3D digital twin. Field-based geomechanical measurements including discontinuity orientations, joint classifications, and strength parameters were integrated with digital analyses to identify and evaluate hazardous rock blocks. Kinematic assessments conducted in the study revealed susceptibility to planar, wedge, and toppling failures. The results showed the role of lithological structure, active tectonics, and environmental factors in driving slope instability. The proposed methodology demonstrates effective use of digital twin technologies in conjunction with traditional geotechnical techniques, offering a replicable and non-invasive approach for site-scale hazard evaluation and conservation planning in heritage contexts. This work contributes to the advancement of interdisciplinary methods for geohazard-informed management of cultural landscapes. Full article

The vibration noise of plate structures in engineering is strongly related to the modal resonance, and modal design is the key to improve the dynamic characteristics of plate structures and avoid structural resonance. This paper investigates the dynamic and mode characteristics for an edge periodic acoustic black hole plate structure to provide a new approach to vibration and sound attenuation in plate structures. Firstly, based on the principles of symmetry and periodicity, this work presents the geometrical modeling and mathematical description of a rectangular plate with symmetrical periodic acoustic black holes at its edge. Then, it presents the dynamic modeling of a rectangular plate with periodic acoustic black holes at its edge via the “remove-and-fill” substitution method, which reveals the effects of the structural parameters and period distribution, etc., on the modal characteristics of vibration. The study indicates that the power law index, radius, number and configuration (e.g., semicircular, rectangular block shape) of the edge periodic acoustic black holes significantly affect the modal frequency of the rectangular plate, and increasing the radius of the acoustic black holes or the number of the black holes results in a decrease in the modal frequency of the rectangular plate. Moreover, the four-side symmetric layout achieves broader modal frequency modulation, while semicircular acoustic black holes can achieve a lower modal frequency compared with the rectangular wedge-shaped acoustic black hole. The theoretical model is verified by finite element simulation (FEM) and experiments, in which the errors of the first six modal frequencies are within 2%. The research in this paper provides a theoretical basis for the realization of modal frequency control in plate structures and the suppression of structural resonance through the design of edge periodic acoustic black hole structures. Full article

Patellar luxation is common in small breed dogs and is often treated surgically. This study compares the long-term outcomes of two surgical techniques, trochlear wedge recession (TWR) and trochlear block recession (TBR), for medial patellar luxation (MPL) with regard to osteoarthritis (OA) progression. High inter-observer agreement was hypothesized for the use of a modified OA scoring system and fewer OA changes in the TBR group. This study included 25 dogs (<15 kg) with grade-2 or -3 MPLs treated at the University of Veterinary Medicine Vienna (2016–2021). A total of 32 stifle joints (TWR Group n = 11, TBR Group n = 21) were evaluated pre-operatively and at least one year post-operatively using a modified OA scoring system. A statistical analysis was conducted to compare OA progression between the techniques. The inter-observer agreement was high. The OA scores increased in both groups post-operatively, with TBR demonstrating a greater progression at specific points. Overall, no significant differences were found between the techniques. These findings suggest that OA progression does not significantly differ between TWR and TBR. The modified OA scoring system has shown to be reliable for assessing OA progression after treatment. Further prospective studies with larger study populations incorporating clinical assessments are needed for a better understanding of the surgical impacts on OA development. Full article

In order to better understand the micropore structure of shale reservoir in Jiyang Depression, permeability damage test, low temperature nitrogen adsorption and scanning electron microscopy (SEM) were carried out on six cores in the target block. The adsorption isotherms were analyzed by Frenkel–Halsey–Hill (FHH) model, and the fractal dimensions of different layers were calculated. The results show that the shale pore system is mainly composed of organic nanopores, inorganic nanopores and micro-fractures. The inorganic pores are mainly distributed around or inside the mineral particles, while microcracks are commonly found between mineral particles or at the organic–mineral interface. Organic pores are located within or between organic particles. The results of nitrogen adsorption show that the shale pores are mainly H2/H3 hysteresis loops with wedge, plate or ink bottle shapes. The pore structure is highly complex, and the fractal dimension is high. The mean D1 fractal dimension, which represents pore surface roughness, is 2.3788, and the mean D2 fractal dimension, which represents pore structure complexity, is 2.7189. The fractal dimension is positively correlated with specific surface area and total pore volume and negatively correlated with average pore radius. The permeability damage rates of the N layer, B layer, and F layer are 17.39%, 20.2%, and 21.6%, respectively. The contact Angle of the core decreases with the increase in water skiing time. In this study, the micropore structure of different formations in Jiyang Depression is compared and analyzed, which provides valuable insights for the optimization and differentiated development of shale oil and gas resources. Full article

Background: Stress-induced cardiomyopathy (SI-CM) is a transient left ventricular dysfunction triggered by emotional or physical stress, often resolving with supportive care. However, severe cases may progress to cardiogenic shock (CS), requiring mechanical circulatory support (MCS). High-profile transvalvular pumps (HPTP), a form of percutaneous ventricular assist device, offer promising hemodynamic support in acute heart failure. This report explores HPTP use in SI-CM-related CS through two complex clinical cases. Case Summary: Two elderly female patients presented with severe CS secondary to apical-variant SI-CM. Case 1 involved a 67-year-old woman with sepsis, colonic perforation, and recurrent SI-CM, leading to profound low-output shock despite multiple vasopressors and inotropes. HPTP was implanted via the axillary artery, allowing for surgical management of intra-abdominal pathology and eventual cardiac recovery. Case 2 featured a 77-year-old woman with multifocal pneumonia, severe mitral regurgitation, and complete heart block. HPTP implantation stabilized her hemodynamics, facilitated extubation, and led to full recovery of ventricular function. Results: Both patients showed marked improvement in cardiac output and systemic perfusion following HPTP insertion. Echocardiograms post-device removal revealed normalization of left ventricular ejection fraction (55–64%). Hemodynamic data confirmed reduced pulmonary capillary wedge pressure and systemic vascular resistance. Conclusion: These cases highlight the potential of HPTP in managing SI-CM-related CS, especially when traditional therapies are inadequate or contraindicated. HPTP can rapidly restore hemodynamic stability and support myocardial recovery. While current data are limited, these observations underscore the need for broader investigation into the role of HPTP in this setting. Full article

Hydraulic fracturing is widely used for developing shale reservoirs with low porosity and permeability. Large volumes of fracturing fluids are injected into reservoirs, yet the impact of these fluids on shale is not entirely understood. This study investigates the effects of commonly used fracturing fluids on the fundamental properties of shale during the shut-in period using experimental methods. Shale samples are collected from the Longmaxi Formation in the Sichuan Basin. Two types of fracturing fluids (guar gel and slickwater) are prepared for tests. The effects of these fluids on shale’s mineral composition, pore distribution, and fracture structure are analyzed using a range of techniques, including X-ray diffraction, nuclear magnetic resonance, nitrogen adsorption-desorption, and X-ray computed tomography scanning. The results show that the shale is composed of quartz, siderite, and clay minerals. The reservoir’s pore structure is relatively uniform, with a higher proportion of small pores and a predominance of wedge-shaped pore types. The porosity ranges from 1.8% to 4.33%, with an average pore diameter varying between 10.8 nm and 24.8 nm. More fracturing fluid enters the reservoir as shut-in time increases. Initially, fluid invasion occurs rapidly, but the volume of infiltrated fluid stabilizes after 15 days. The fracturing fluids cause chemical reactions and hydration of clay minerals. Both fracturing fluids lead to a decrease in the proportion of clay minerals and an increase in the proportion of quartz. After soaking in guar gel, the shale’s surface area and pore volume decrease while the average pore diameter increases. The breakdown of guar gel leads to a residue that blocks pore spaces, resulting in lower surface porosity. In contrast, slickwater increases surface area and pore volume while reducing the average pore diameter. Slickwater also promotes the development of fractures, with larger pores forming around them. The results suggest that slickwater is more effective than guar gel in improving shale’s pore structure. Full article

Spontaneous ventilation lung surgery (SVLS) without intubation is aimed at avoiding adverse effects of mechanical ventilation lung surgery (MVLS) entailing one-lung mechanical ventilation through a double-lumen tracheal tube. This innovative strategy has evolved following the publication of a small randomized study of thoracoscopic pulmonary wedge resection carried out under spontaneous ventilation without tracheal intubation in fully awake patients. It now entails target-controlled sedation, the use of a laryngeal mask, and thoracic analgesia by intercostal or paravertebral blocks and has shown promise both in unicenter and multicenter studies, resulting in optimal feasibility and safety and highly satisfactory results, particularly in patients undergoing lung cancer resection and metastasectomy, lung biopsy for undetermined interstitial lung disease, lung volume reduction surgery for end-stage emphysema, and bullectomy for primary and secondary spontaneous pneumothorax. However, concerns and unresolved issues still exist regarding the advantages and disadvantages of SVLS as well as the identification of optimal indications. This perspective is aimed at providing a critical overview of the current knowledge about SVLS with emphasis on recent data comparing the results with those of MVLS published in the last 10 years. Full article

The spatiotemporal distribution of major earthquakes in the study area (1600–2024) is analyzed to tentatively recognize the possible connections with the short-term (from decades to centuries) evolution of the ongoing tectonic processes. This study suggests that during the period considered, seismic activity has been predominantly related to the shortening processes accommodating the convergence of northwestern Nubia with the Iberian and Moroccan plates that mainly involve the westward escape of the Alboran wedge and the NNE-ward escape of the Iberian block. This deformation pattern is inferred from the seismic activity in the North Atlantic domain, the Rif and Betics belts, the western Iberian fault system (onshore and offshore), the Transmoroccan fault system and the Pyrenean thrust front. Seismic activity in the Tell is mainly driven by the Nubia–Eurasia convergence, even though it can be also influenced by the major westward displacements of the Anatolian–Aegean–Adriatic–Pelagian system. This hypothesis could explain the marked increase in seismic activity that occurred in the Tell in the last decades, when that zone may have been affected by the perturbation triggered by the large post-1939 westward displacement of Anatolia. The pieces of evidence and the arguments reported in this study might provide insights into the possible spatial distribution of major earthquakes in the next decades. Full article

Rock bolting in underground environments is used for different fundamental reasons, including suspending potentially loosened blocks, clamping small wedges together, inducing a protective pressure arch along the contour of excavated voids to improve the self-supporting capacity of the ground, and providing passive pressure in integrated support systems. In this study, we describe a testing procedure that was developed to investigate the grouted annulus of a rock bolt using a low-cost investigation method. This diagnostic technique was based on the dynamic response of the system, where mechanical vibrations were induced within the rock bolt and the response was recorded by using geophones/accelerometers on the protruding element of the bolt (the collar and head). The collected signal was then processed to estimate the spectral response, and the amplitude spectrum was analyzed to detect the resonance frequencies. A 3D finite element model of the rock bolt and grouting was established to simulate the quality of the coupling by varying the mechanical properties of the grouting. The model’s response for the studied geometry of the rock bolt suggested that a poor quality of grouting was usually associated with flexural modes of vibration with a low resonance frequency. Good-quality grouting was associated with a frequency higher than 1400 Hz, where the axial vibration was mainly excited. Our analyses referred to short rock bolts, which are usually adopted in small tunnels. The interpretation of the experimental measurements assumed that the spectral response was significantly affected by the quality of the grouting, as demonstrated by the modeling procedure. The resonant frequency was compared with the results of the model simulation. The method was used to test the quality of rock bolts in a small experimental tunnel carved from andesite rock in Chile. Low-cost shock sensors (piezoelectric geophones) with low sensitivity but a wide frequency band were used. The main research outcome was the development of a reliable method to model the dynamic response of rock bolts in mines or for experimental applications in tunnels. Albeit limited to the current specific geometries, the modeling and testing will be adapted to other anchor/bolt options. Full article

Background and Objectives: Proximal tibiofibular joint detachment (PTFJD) is a fibular untethering procedure during lateral closing-wedge high tibial osteotomy (LCWHTO) for varus knee osteoarthritis. However, the PTFJD procedure is technically demanding, and confirmation of clear joint separation is not straightforward. The aim of this study was to compare the degree of completion and safety of PTFJD versus tibial-sided osteotomy (TSO); this latter procedure is our novel technique for fibular untethering during LCWHTO. Materials and Methods: Sixteen fresh frozen cadaver knees from eight cadavers were included in the study. Among the eight pairs of knees, one knee was randomly assigned to undergo PTFJD and the other knee to undergo TSO, which separates the fibula by osteotomizing the lateral cortex of the proximal tibia at the medial side of the proximal tibiofibular joint for fibular untethering during LCWHTO. After each procedure with LCWHTO, the posterior compartment of each knee was dissected to compare the degree of procedural completion and the distance from the posterior detachment or osteotomy site to posterior neurovascular structures between PTFJD and TSO groups. The pass-through test crossing the separation site from anterior to posterior using an osteotome was also performed to evaluate the protective effect of the muscular structures of the posterior compartment. Results: In the PTFJD group, four of eight cases (50%) showed fibular head fractures rather than division of the proximal tibiofibular joint. In contrast, in all TSO cases, the lateral cortex of the proximal tibia was clearly osteotomized from the medial side of the posterior proximal tibiofibular joint. Distances from the posterior detachment or osteotomy site to the common peroneal nerve, popliteal artery, and anterior tibial artery in the PTFJD and TSO groups were 20.8 ± 3.3 mm and 22.9 ± 3.6 mm (p = 0.382), 11.0 ± 2.4 mm and 9.8 ± 2.8 mm (p = 0.382), and 14.8 ± 1.9 mm and 14.9 ± 2.5 mm (p = 0.721), respectively. In the pass-through test, an osteotome was able to pass anteriorly to posteriorly in all eight PTFJD group cases. However, the osteotome was blocked posteriorly by the popliteus muscle in the TSO group cases, indicating protection of posterior neurovascular structures during the TSO procedure. Conclusions: TSO, a novel fibular untethering procedure for LCWHTO, resulted in clear separation of the fibula from the lateral tibial cortex, and protection of posterior neurovascular structures by the popliteus muscle during the procedure. We anticipate that our novel surgical technique will provide more clear-cut and safer fibular untethering for LCWHTO. Full article

It is suggested that the occurrence of tectonic activity in the northern Nubian belts (Tell-Rif and Atlas systems) since the Late Pliocene can be interpreted as one of the processes that were produced in the central and western Mediterranean zones by the collision of the Adriatic continental promontory with the Anatolian–Aegean Tethyan system. Since then, the consumption of the residual low-buoyancy domains in the Mediterranean area was allowed by a major change in the plate mosaic and the related kinematics. The new tectonic setting started with the decoupling of a large portion of the Adriatic domain (Adria plate) from Nubia, through the formation of a long discontinuity crossing the Ionian domain (Victor Hensen–Medina fault) and the Hyblean–Pelagian domain (Sicily channel fault system). Once decoupled, the Adria plate underwent a clockwise rotation, at the expense of E–W shortening in the Hyblean–Pelagian domain and in the northern Nubian margin. The shortening in the Pelagian domain was accommodated by the northward escape of the Adventure wedge, which in turn caused the northward displacement of the eastern Maghrebian sector. The indentation of these structures into the Alpine–Apennine material lying east of the Corsica–Sardinia block induced an east to southeastward escape of wedges (southern Apennines and Calabria). This occured at the expense of the remnant Ionian Tethys oceanic domain and the thinned Adriatic margin. The extensional regime that developed in the wake of the migrating wedges led to the formation of the central and southern Tyrrhenian basins. In the northern Nubian belts, the westward push of the Adria–Hyblean–Pelagian domain has been accommodated by oroclinal bending, thrusting and uplifting across the Tell and Atlas belts. This geodynamic context might explain some features of the seismicity time pattern observed in the Tell system. Full article

Background and Objectives: Video-assisted thoracoscopic surgery (VATS) is associated with less postoperative pain than traditional open thoracotomy. However, trocar and chest tube placement may damage the intercostal nerves, causing significant discomfort. An ultrasound-guided serratus anterior plane block (SAPB) is a promising mode of pain management; this reduces the need for opioids and the associated side-effects. This study evaluated whether SAPB, compared to intravenous analgesia alone, reduces opioid consumption after thoracoscopic lung wedge resection. Materials and Methods: In total, 22 patients undergoing VATS lung wedge resections were randomized into two groups (SAPB and control): both received intravenous patient-controlled analgesia (PCA), and one group received additional SAPB. The primary outcome was the cumulative intravenous fentanyl consumption at 8 h postoperatively. The visual analog scale (VAS) pain scores and the incidence of postoperative complications were assessed over 48 h post surgery. Results: Fentanyl consumption by 8 h post surgery was significantly lower in the SAPB group than in the control group (183 ± 107 μg vs. 347 ± 202 μg, p = 0.035). Although the VAS scores decreased with time in both groups, the differences were not statistically significant. The SAPB group required fewer opioids by 48 h. No significant between-group differences were observed in postoperative complications, including nausea and vomiting. Conclusions: SAPB effectively reduced opioid consumption after VATS lung wedge resection. SABP may serve as a valuable component of multimodal pain management. Full article

When encountering heavy oil reservoirs during drilling, due to the change in pressure difference inside the well, heavy oil will invade the drilling fluid, and drilling fluid will spill into the reservoir along the formation fractures, affecting the drilling process. A supramolecular polymer gel-based temporary plugging agent was prepared using acrylamide (AM), butyl acrylate (BA), and styrene (ST) as reacting monomers, N, N-methylenebisacrylamide (MBA) as a crosslinking agent, ammonium persulfate (APS) as an initiator, and poly(vinyl alcohol) (PVA) as a non-covalent component. A supermolecular polymer gel with a temperature tolerance of 120 °C and acid solubility of 90% was developed. The experimental results demonstrated that a mechanically robust, thermally stable supramolecular polymer gel was successfully synthesized through the copolymerization of AM, BA, and ST, as well as the in situ formation hydrogen bonding between poly (AM-co-BA-co-ST) and PVA, leading to a three-dimensional entangled structure. The gel-forming solution possessed excellent gelling performance even in the presence of a high content of salt and heavy oil, demonstrating superior resistance to salt and heavy oil under harsh reservoir conditions. High-temperature and high-pressure plugging displacement experiments proved that the supramolecular polymer gel exhibited high pressure-bearing capacity, and the blocking strength reached 5.96 MPa in a wedge-shaped fracture with a length of 30 cm. Furthermore, the dissolution rate of the supramolecular polymer gel was as high as 96.2% at 120 °C for 48 h under a 15% HCl solution condition. Full article

RNA-based next-generation sequencing (RNA-seq) represents the gold standard for detecting gene fusion in non-small cell lung cancer (NSCLC). Despite this, RNA instability makes the management of tissue samples extremely complex, resulting in a significant number of test failures with missing data or the need to switch to other techniques. In the present study, we analyzed pre-analytical variables in 140 tumor tissue samples from patients affected by NSCLC to detect features that increase the chances of successful RNA-seq. We found that the success rate of the analysis positively correlates with the RNA concentration and fragmentation index. Interestingly, small biopsies were more suitable samples than surgical specimens and cell blocks. Among surgical specimens, wedge resections demonstrated better results than lobectomy. Moreover, samples stored for less than 30 days (1 month) had a better chance of success than older samples. Defining the role of pre-analytical variables in RNA-seq allows the detection of more suitable samples for analysis and more effective planning of molecular-based diagnostic approaches in NSCLC. Full article