Search results for: fractures of transient plasticity

Authors: P. Panwalkar, K. Veravalli, R. Gwynn, M. Tofighi, R. Clement, A. Mofidi

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When operating on tibial plateau fracture especially medial tibial plateau, it has regularly been said “where do I put my thumb to reduce the fracture”. This refers to the ideal placement of the buttress device to hold the fracture till union. The aim of this study was to see if one can identify this sweet spot using a CT scan. Methods: Forty-five tibial plateau fractures with medial plateau involvement were identified and included in the study. The preoperative CT scans were analysed and the medial plateau involvement pattern was classified based on modified radiological classification by Yukata et-al of stress fracture of medial tibial plateau. The involvement of part of plateau was compared with position of buttress plate position which was classified as medial posteromedial or both. Presence and position of the buttress was compared with ability to achieve and hold the reduction of the fracture till union. Results: Thirteen fractures were type-1 fracture, 19 fractures were type-2 fracture and 13 fractures were type-3 fracture. Sixteen fractures were buttressed correctly according to the potential deformity and twenty-six fractures were not buttressed and three fractures were partly buttressed correctly. No fracture was over butressed! When the fracture was buttressed correctly the rate of the malunion was 0%. When fracture was partly buttressed 33% were anatomically united and 66% were united in the plane of buttress. When buttress was not used, 14 were malunited, one malunited in one of the two planes of deformity and eleven anatomically healed (of which 9 were non displaced!). Buttressing resulted in statistically significant lower mal-union rate (x2=7.8, p=0.0052). Conclusion: The classification based on involvement of medial condyle can identify the placement of buttress plate in the tibial plateau. The correct placement of the buttress plate results in predictably satisfactory union. There may be a correlation between injury shape of the tibial plateau and the fracture type.

Keywords: knee, tibial plateau, trauma, CT scan, surgery

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Authors: Hong Je Kang, Young Chae Choi, Jin Sung Park, Isac Kim

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Purpose: Osteoporotic fractures are an important among postmenopausal women. When osteoporotic distal radial fractures occur, osteoporosis must be treated to prevent the hip and spine fractures. Intravenous injection of Zoledronic acid is expected to improve preventing osteoporotic fractures. Many articles reported the effect of intravenous Zoledronic acid to BMD of the hip and spine fracture or non-fracture patients with low BMD. However, that with distal radial fractures has rarely been reported. Therefore, the authors decided to study the effect of Zoledronic acid in BMD score, bone union, and bone turnover markers in the patients who underwent volar plating due to osteoporotic distal radial fractures. Materials: From April 2018 to May 2022, postmenopausal women aged 55 years or older who had osteoporotic distal radial fractures and who underwent surgical treatment using volar plate fixation were included. Zoledronic acid (5mg) was injected intravenously between 3 and 5 days after surgery. BMD scores after 1 year of operation were compared with the initial scores. Bone turnover markers were measured before surgery, after 3 months, and after 1 year. Radiological follow-up was performed every 2 weeks until the bone union and at 1 year postoperatively. Clinical outcome indicators were measured one year after surgery, and the occurrence of side effects was observed. Result: Total of 23 patients were included, with a lumbar BMD T score of -2.89±0.2 before surgery to -2.27±0.3 one year after surgery (p=0.012) and a femoral neck BMD T score of -2.45±0.3 before surgery to -2.36±0.3 (p=0.041) after one year, and all were statistically significant. Measured as bone resorption markers, serum CTX-1 was 337.43±10.4 pg/mL before surgery, 160.86±8.7 pg/mL (p=0.022) after three months, and 250.12±12.7 pg/mL (p=0.031) after one year. Urinary NTX-1 was 39.24±2.2 ng/mL before surgery, 24.46±1.2 ng/mL (p=0.014) after three months and 30.35±1.6 ng/mL (p=0.042) after one year. Measured as bone formation markers, serum osteocalcin was 13.04±1.1 ng/mL before surgery, 8.84±0.7 ng/mL (p=0.037) after 3 months and 11.1±0.4 ng/mL (p=0.026) after one year. Serum bone-specific ALP was 11.24±0.9 IU/L before surgery, 8.25±0.9 IU/L (p=0.036) after three months, and 10.2±0.9 IU/L (p=0.027) after one year. All were statistically significant. All cases showed bone union within an average of 6.91±0.3 weeks without any signs of failure. Complications were found in 5 out of 23 cases (21.7%), such as headache, nausea, muscle pain, and fever. Conclusion: When Zoledronic acid was used, BMD was improved in both the spine and femoral neck. This may reduce the likelihood and subsequent morbidity of additional osteoporotic fractures. This study is meaningful in that there was no difference in the duration of bone union and radiological characteristics in patients with distal radial fractures administrated with intravenous BP early after the fractures, and improvement in BMD and bone turnover indicators was measured.

Keywords: zeoldreonic acid, BMD, osteoporosis, distal radius

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Authors: Khoshnaw Khalid Hama Saleh, Ergun Ercelebi

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Increasingly complex modern power systems require stability, especially for transient and small disturbances. Transient stability plays a major role in stability during fault and large disturbance. This paper compares a power system stabilizer (PSS) and static Var compensator (SVC) to improve damping oscillation and enhance transient stability. The effectiveness of a PSS connected to the exciter and/or governor in damping electromechanical oscillations of isolated synchronous generator was tested. The SVC device is a member of the shunt FACTS (flexible alternating current transmission system) family, utilized in power transmission systems. The designed model was tested with a multi-machine system consisting of four machines six bus, using MATLAB/SIMULINK software. The results obtained indicate that SVC solutions are better than PSS.

Keywords: FACTS, MATLAB/SIMULINK, multi-machine system, PSS, SVC, transient stability

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Authors: S. alireza Mirghasemi, Shervin Rashidinia, Mohammadsaleh Sadeghi, Mohsen Talebizadeh, Narges Rahimi Gabaran, S. Shahin Eftekhari, Sara Shahmoradi

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Purpose: There are various pin-in-plaster methods for treating distal radius fractures. This study is meant to introduce a modified technique of pin-in-plaster. Materials and methods: Fifty-four patients with distal radius fractures were followed up for one year. Patients were excluded if they had type B fractures according to AO classification, multiple injuries or pathological fractures, and were treated more than 7 days after injury. Range of motion and functional results were evaluated. Radiographic parameters including radial inclination, tilt, and height, were measured preoperatively and postoperatively. Results: The average radial tilt was 10.6° and radial height was 10.2 mm at the sixth month postoperatively. Three cases of pin tract infection were recorded, who were treated totally with oral antibiotics. There was no case of pin loosening. Of total 73 patients underwent surgery, three cases of radial nerve irritation were recorded at the time of cast removal. All of them resolved at the 6th month follow up. No median nerve compression and carpal tunnel syndrome have found. We also had no case of tendon injury. Conclusion: Our modified technique is effective to restore anatomic congruity and maintain reduction.

Keywords: distal radius fracture, percutaneous pinning, pin-in-plaster, modified method of pin-in-plaster, operative treatment

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Authors: Krishna Prasad Regmi, Jun-Bo Tu, Cheng-Qun Hou, Li-Feng Li

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Maxillofacial trauma in a pediatric group of patients is particularly challenging, as these patients have significant differences from adults as far as the facial skeleton is concerned. Mandibular condylar fractures are common presentations to hospitals across the globe and remain the most important cause of temporomandibular joint (TMJ) ankylosis. The etiology and epidemiology of pediatric trauma involving the diacapitular condylar fractures (DFs) have been reported in a large series of patients. Nevertheless, little is known about treatment protocols for DFs in children. Accordingly, the treatment modalities for the management of pediatric fractures also differ. We suggest following the PDA and intracapsular ABC classification of condylar fracture to increase the overall postoperative satisfaction level that bypasses the change of subjective feelings of patients’ from preoperative to the postoperative condition. At the same time, use of 3-D technology and surgical navigation may also increase treatment accuracy.

Keywords: maxillofacial trauma, diacapitular fracture, condylar fracture, PDA classification

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Authors: I Made Ginarsa, Agung Budi Muljono, I Made Ari Nrartha

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Transient voltage response appears in power system operation when an additional loading is forced to load bus of power systems. In this research, improvement of transient voltage response is done by using power system stabilizer-static var compensator (PSS-SVC) based on adaptive neuro-fuzzy inference system (ANFIS)-algorithm. The main function of the PSS is to add damping component to damp rotor oscillation through automatic voltage regulator (AVR) and excitation system. Learning process of the ANFIS is done by using off-line method where data learning that is used to train the ANFIS model are obtained by simulating the PSS-SVC conventional. The ANFIS model uses 7 Gaussian membership functions at two inputs and 49 rules at an output. Then, the ANFIS-PSS and ANFIS-SVC models are applied to power systems. Simulation result shows that the response of transient voltage is improved with settling time at the time of 4.25 s.

Keywords: improvement, transient voltage, PSS-SVC, ANFIS, settling time

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Authors: Seyed-Ali Sadegh-Zadeh, Mahboobe Bahrami, Sahar Ahmadi, Seyed-Yaser Mousavi, Hamed Atashbar, Amir M. Hajiyavand

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This paper presents an investigation into the concept of neural reshaping, which is crucial for achieving strong artificial intelligence through the development of AI algorithms with very high plasticity. By examining the plasticity of both human and artificial neural networks, the study uncovers groundbreaking insights into how these systems adapt to new experiences and situations, ultimately highlighting the potential for creating advanced AI systems that closely mimic human intelligence. The uniqueness of this paper lies in its comprehensive analysis of the neural reshaping process in both human and artificial intelligence systems. This comparative approach enables a deeper understanding of the fundamental principles of neural plasticity, thus shedding light on the limitations and untapped potential of both human and AI learning capabilities. By emphasizing the importance of neural reshaping in the quest for strong AI, the study underscores the need for developing AI algorithms with exceptional adaptability and plasticity. The paper's findings have significant implications for the future of AI research and development. By identifying the core principles of neural reshaping, this research can guide the design of next-generation AI technologies that can enhance human and artificial intelligence alike. These advancements will be instrumental in creating a new era of AI systems with unparalleled capabilities, paving the way for improved decision-making, problem-solving, and overall cognitive performance. In conclusion, this paper makes a substantial contribution by investigating the concept of neural reshaping and its importance for achieving strong AI. Through its in-depth exploration of neural plasticity in both human and artificial neural networks, the study unveils vital insights that can inform the development of innovative AI technologies with high adaptability and potential for enhancing human and AI capabilities alike.

Keywords: neural plasticity, brain adaptation, artificial intelligence, learning, cognitive reshaping

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Authors: Srikanta Tagore Sarkar, Prasanta Kumar Mandal, Dibakar Roy

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The association of a capitate fracture with a scaphoid fracture has been termed as the naviculocapitate syndrome. The existence of some nondisplaced fractures of scaphoid and capitate with or without the fracture of lunate or radius suggests that there is a spectrum of these injuries, and this confuses the terminology. With our case; we report an unusual variety of this naviculocapitate syndrome with distal radial Colles fracture in addition to the nondisplaced fractures of the scaphoid, capitate and the dorsal lip of radial fracture. When we looked at the literature there is no another Colles fracture reported together with undisplaced scapho-capitate syndrome. The coronal and sagittal images that obtained from the MDCT (Multidetector computed tomography) is useful and effective imaging modality to diagnose complex wrist fractures with more details that are not detected in X-rays.

Keywords: scaphoid, capitate, Colles’ fracture, syndrome, MDCT, unusual

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Authors: K. Cartelier, D. Aime, V. Vernoud, J. Buitink, J. M. Prosperi, K. Gallardo, C. Le Signor

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Legumes can produce protein-rich seeds without nitrogen fertilizer through root symbiosis with nitrogen-fixing rhizobia. Rich in lysine, these proteins are used for human nutrition and animal feed. However, the instability of seed protein yield and quality due to environmental fluctuations limits the wider use of legumes such as pea. Breeding efforts are needed to optimize and stabilize seed nutritional value, which requires to identify the genetic determinism of seed protein plasticity in response to the environment. Towards this goal, we have studied the plasticity of protein content and composition of seeds from a collection of 200 Medicago truncatula ecotypes grown under four controlled conditions (optimal, drought, and winter/spring sowing). A quantitative analysis of one-dimensional protein profiles of these mature seeds was performed and plasticity indices were calculated from each abundant protein band. Genome-Wide Association Studies (GWAS) from these data identified major GWAS hotspots, from which a list of candidate genes was obtained. A Gene Ontology Enrichment Analysis revealed an over-representation of genes involved in several amino acid metabolic pathways. This led us to propose that environmental variations are likely to modulate amino acid balance, thus impacting seed protein composition. The selection of candidate genes for controlling the plasticity of seed protein composition was refined using transcriptomics data from developing Medicago truncatula seeds. The pea orthologs of key genes were identified for functional studies by mean of TILLING (Targeting Induced Local Lesions in Genomes) lines in this crop. We will present how this study highlighted mechanisms that could govern seed protein plasticity, providing new cues towards the stabilization of legume seed quality.

Keywords: GWAS, Medicago truncatula, plasticity, seed, storage proteins

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Authors: H. Bhowmik, A. Faisal, Ahmed Al Yaarubi, Nabil Al Alawi

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Experiments are conducted to analyze the steady-state and the power-on transient natural convection heat transfer from a horizontal cylinder mounted in a vertical up flow circular duct. The heat flux ranges from 177 W/m² to 2426 W/m² and the Rayleigh number ranges from 1×10⁴ to 4.35×10⁴. For natural air flow and constant heat flux condition, the effects of heat transfer around the cylinder under steady-state condition are investigated. The steady-state results compare favorably with that of the available data. The effects of transient heat transfer data on different angular position of the thermocouple (0^o, 90^o, 180^o) are also reported. It is observed that the transient heat transfer around the cylinder is strongly affected by the position of thermocouples. In the transient region, the rate of heat transfer obtained at 90^o and 180^o are higher than that of stagnation point (0^o). Finally, the dependence of the average Nusselt number on Rayleigh number for steady and transient natural convection heat transfer are analyzed, and a correlation equation is presented.

Keywords: Fourier number, Nusselt number, Rayleigh number, steady state, transient

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Authors: G. Tamulevičius, A. Serackis, T. Sledevič, D. Navakauskas

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We consider the biggest challenge in speech recognition – noise reduction. Traditionally detected transient noise pulses are removed with the corrupted speech using pulse models. In this paper we propose to cope with the problem directly in Dynamic Time Warping domain. Bidirectional Dynamic Time Warping algorithm for the recognition of isolated words impacted by transient noise pulses is proposed. It uses simple transient noise pulse detector, employs bidirectional computation of dynamic time warping and directly manipulates with warping results. Experimental investigation with several alternative solutions confirms effectiveness of the proposed algorithm in the reduction of impact of noise on recognition process – 3.9% increase of the noisy speech recognition is achieved.

Keywords: transient noise pulses, noise reduction, dynamic time warping, speech recognition

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Authors: Fabiha Tanzeem

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BACKGROUND: Osteoporosis is a skeletal disease that is associated with a reduction in bone mass and microstructures of the bone and deterioration of bone tissue. Fragility fracture due to osteoporosis is the most significant complication of osteoporosis. The increasing prevalence of fragility fractures presents a growing burden on the global economy. There is a rapidly evolving need to improve awareness of the costs associated with these types of fractures and to review current policies and practices for the prevention and management of the disease. This systematic review will identify and describe the direct and indirect costs associated with osteoporotic fragility fractures from a global perspective from the included studies. The review will also find out whether the costs required for the treatment of fragility fractures due to osteoporosis impose an economic burden on the global healthcare system. METHODS: Four major databases were systematically searched for direct and indirect costs of osteoporotic fragility fracture studies in the English Language. PubMed, Cochrane Library, Embase and Google Scholar were searched for suitable articles published between 1990 and July 2020. RESULTS: The original search yielded 1166 papers; from these, 27 articles were selected for this review according to the inclusion and exclusion criteria. In the 27 studies, the highest direct costs were associated with the treatment of pelvic fractures, with the majority of the expenditure due to hospitalization and surgical treatments. It is also observed that most of the articles are from developed countries. CONCLUSION: This review indicates the significance of the economic burden of osteoporosis globally, although more research needs to be done in developing countries. In the treatment of fragility fractures, direct costs were the main reported expenditure in this review. The healthcare costs incurred globally can be significantly reduced by implementing measures to effectively prevent the disease. Raising awareness in children and adults by improving the quality of the information available and standardising policies and planning of services requires further research.

Keywords: systematic review, osteoporosis, cost of illness

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Authors: Ashok K. Satapathy, Prerana Nashine

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Radiative heat transfer in participating medium was anticipated using the finite volume method. The radiative transfer equations are formulated for absorbing and anisotropically scattering and emitting medium. The solution strategy is discussed and the conditions for computational stability are conferred. The equations have been solved for transient radiative medium and transient radiation incorporated with transient conduction. Results have been obtained for irradiation and corresponding heat fluxes for both the cases. The solutions can be used to conclude incident energy and surface heat flux. Transient solutions were obtained for a slab of heat conducting in slab by thermal radiation. The effect of heat conduction during the transient phase is to partially equalize the internal temperature distribution. The solution procedure provides accurate temperature distributions in these regions. A finite volume procedure with variable space and time increments is used to solve the transient energy equation. The medium in the enclosure absorbs, emits, and anisotropically scatters radiative energy. The incident radiations and the radiative heat fluxes are presented in graphical forms. The phase function anisotropy plays a significant role in the radiation heat transfer when the boundary condition is non-symmetric.

Keywords: participating media, finite volume method, radiation coupled with conduction, heat transfer

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Authors: R. N. Khare, J. P. Sahu, Rajesh Kumar Tamrakar

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Tests were conducted to determine the property of soil with variation of H2SO4 content for soils under different stage. The soils had varying amounts of plasticity’s ranging from low to high plasticity. The unsaturated soil behavior was investigated for different conditions, covering a range of compactive efforts and water contents. The soil characteristic curves were more sensitive to changes in compaction effort than changes in compaction water content. In this research paper two types of water (Ground water Ph =7.9, Turbidity= 13 ppm; Cl =2.1mg/l and surface water Ph =8.65; Turbidity=18.5; Cl=1mg/l) were selected of Bhilai Nagar, State-Chhattisgarh, India which is mixed with a certain type of soil. Results shows that by the presence of ground water day by day the particles are becoming coarser in 7 days thereafter its size reduces; on the other hand by the presence of surface water the courser particles are disintegrating, finer particles are accumulating and also the dry density is reduces. Plasticity soils retained the smallest water content and the highest plasticity soils retained the highest water content at a specified suction. In addition, soil characteristic for soils to be compacted in the laboratory and in the field are still under process for analyzing the bearing capacity. The bearing capacity was reduced 2 to 3 times in the presence of H2SO4.

Keywords: soil compaction, H2SO4, soil water, water conditions

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Authors: D. He, Y. Pang, G. Lodewijks

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Belt conveyors play an important role in continuous dry bulk material transport, especially at the mining industry. Speed control is expected to reduce the energy consumption of belt conveyors. Transient operation is the operation of increasing or decreasing conveyor speed for speed control. According to literature review, current research rarely takes the conveyor dynamics in transient operation into account. However, in belt conveyor speed control, the conveyor dynamic behaviors are significantly important since the poor dynamics might result in risks. In this paper, the potential risks in transient operation will be analyzed. An existing finite element model will be applied to build a conveyor model, and simulations will be carried out to analyze the conveyor dynamics. In order to realize the soft speed regulation, Harrison’s sinusoid acceleration profile will be applied, and Lodewijks estimator will be built to approximate the required acceleration time. A long inclined belt conveyor will be studied with two major simulations. The conveyor dynamics will be given.

Keywords: belt conveyor , speed control, transient operation, dynamics

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Authors: Omid Naeemifar, Ibrahim Naeimifar, Roza Rahbari

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It has been shown that a certain collapse surface may be defined for loose sands in the three dimensional space in which the sample sand experiences collapse and instability leading to an unsteady and strain-softening behaviour. The unsteady state due to collapse surface may lead to such phenomena in the sand as liquefaction and flow behaviour during undrained loading. Investigating the existence of the collapse surface in Firoozkooh 161 sand and its different clay mixtures with various plasticities, the present study aims to carry out an in-depth investigation of the effects of clay percent and its plasticity on the clayey sand behaviours. The results obtained indicate that collapse surface characteristics largely depend on fine percent and its plasticity. Interesting findings are also reported in this paper on the effects of fine sand percent and its plasticity on the behavioural characteristics and liquefaction potential of clayey sands.

Keywords: critical state, collapse surface, liquefaction, clayey sand

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Authors: O. S. Pradeep, S. Vigneshwaran, K. Praveen Kumar, K. Jeyendran, V. R. Sanal Kumar

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The influence of injector attitude on wall heat flux plays an important role in predicting the start-up transient and also determining the combustion chamber wall durability of liquid rockets. In this paper comprehensive numerical studies have been carried out on an idealized liquid rocket combustion chamber to examine the transient wall heat flux during its start-up transient at different injector attitude. Numerical simulations have been carried out with the help of a validated 2d axisymmetric, double precision, pressure-based, transient, species transport, SST k-omega model with laminar finite rate model for governing turbulent-chemistry interaction for four cases with different jet intersection angles, viz., 0^o, 30^o, 45^o, and 60^o. We concluded that the jets intersection angle is having a bearing on the time and location of the maximum wall-heat flux zone of the liquid rocket combustion chamber during the start-up transient. We also concluded that the wall heat flux mapping in liquid rocket combustion chamber during the start-up transient is a meaningful objective for the chamber wall material selection and the lucrative design optimization of the combustion chamber for improving the payload capability of the rocket.  

Keywords: combustion chamber, injector, liquid rocket, rocket engine wall heat flux

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Authors: Weiyao Zhu, Qian Qi, Ming Yue, Dongxu Ma

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Due to the nano-micro pore structures and the massive multi-stage multi-cluster hydraulic fracturing in shale gas reservoirs, the multi-scale seepage flows are much more complicated than in most other conventional reservoirs, and are crucial for the economic development of shale gas. In this study, a new multi-scale non-linear flow model was established and simplified, based on different diffusion and slip correction coefficients. Due to the fact that different flow laws existed between the fracture network and matrix zone, a three-zone composite model was proposed. Then, according to the conformal transformation combined with the law of equivalent percolation resistance, the productivity equation of a horizontal fractured well, with consideration given to diffusion, slip, desorption, and absorption, was built. Also, an analytic solution was derived, and the interference of the multi-cluster fractures was analyzed. The results indicated that the diffusion of the shale gas was mainly in the transition and Fick diffusion regions. The matrix permeability was found to be influenced by slippage and diffusion, which was determined by the pore pressure and diameter according to the Knudsen number. It was determined that, with the increased half-lengths of the fracture clusters, flow conductivity of the fractures, and permeability of the fracture network, the productivity of the fractured well also increased. Meanwhile, with the increased number of fractures, the distance between the fractures decreased, and the productivity slowly increased due to the mutual interference of the fractures. In regard to the fractured horizontal wells, the free gas was found to majorly contribute to the productivity, while the contribution of the desorption increased with the increased pressure differences.

Keywords: multi-scale, fracture network, composite model, productivity

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Authors: Guoyang Fu, Wei Yang, Chun-Qing Li

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The most common type of cracks that appear on metal pipes is longitudinal cracks. For ductile metal pipes, the existence of plasticity eases the stress intensity at the crack front and consequently increases the fracture resistance. It should be noted that linear elastic fracture mechanics (LEFM) has been widely accepted by engineers. In order to make the LEFM applicable to ductile metal materials, the increase of fracture toughness due to plasticity should be excluded from the total fracture toughness of the ductile metal. This paper aims to develop a model of elastic fracture toughness for ductile metal pipes with external longitudinal cracks. The derived elastic fracture toughness is a function of crack geometry and material properties of the cracked pipe. The significance of the derived model is that the well-established LEFM can be used for ductile metal material in predicting the fracture failure.

Keywords: Ductile metal pipes, elastic fracture toughness, longitudinal crack, plasticity

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Authors: Harish Aryal

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The safe and reliable operation of nuclear reactors has always been one of the topmost priorities in the nuclear industry. Transient testing allows us to understand the time-dependent behavior of the neutron population in response to either a planned change in the reactor conditions or unplanned circumstances. These unforeseen conditions might occur due to sudden reactivity insertions, feedback, power excursions, instabilities, and accidents. To study such behavior, we need transient testing, which is like car crash testing, to estimate the durability and strength of a car design. In nuclear designs, such transient testing can simulate a wide range of accidents due to sudden reactivity insertions and helps to study the feasibility and integrity of the fuel to be used in certain reactor types. This testing involves a high neutron flux environment and real-time imaging technology with advanced instrumentation with appropriate accuracy and resolution to study the fuel slumping behavior. With the aid of transient testing and adequate imaging tools, it is possible to test the safety basis for reactor and fuel designs that serves as a gateway in licensing advanced reactors in the future. To that end, it is crucial to fully understand advanced imaging techniques both analytically and via simulations. This paper presents an innovative method of supporting real-time imaging of fuel pins and other structures during transient testing. The major fuel-motion detection device that is studied in this dissertation is the Hodoscope which requires collimators. This paper provides 1) an MCNP model and simulation of a Transient Reactor Test (TREAT) core with a central fuel element replaced by a slotted fuel element that provides an open path between test samples and a hodoscope detector and 2) a choice of good filter to improve image resolution.

Keywords: hodoscope, transient testing, collimators, MCNP, TREAT, hodogram, filters

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Authors: Patel Darshan Shaileshkumar, M. G. Vanza

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Black cotton soil is problematic soil for any construction work. Black cotton soil contains montmorillonite in its structure. Due to this mineral, black cotton soil will attain maximum swelling and shrinkage. Due to these volume changes, it is necessary to stabilize black cotton soil before the construction of the road. For soil stabilization use of pozzolanic waste is found to be a good solution by some researchers. The palm kernel shell ash (PKSA) is a pozzolanic material that can be used for soil stabilization. Basically, PKSA is a waste material, and it is available at a cheap cost. Palm kernel shell is a waste material generated in palm oil mills. Then palm kernel shell is used in industries instead of coal for power generation. After the burning of a palm kernel shell, ash is formed; the ash is called palm kernel shell ash (PKSA). The PKSA contains a free lime content that will react chemically with the silicate and aluminate of black cotton soil and forms a C-S-H and C-A-H gel which will bines soil particles together and reduce the plasticity of the soil. In this study, the PKSA is added to the soil. It was found that with the addition of PKSA content in the soil, the liquid limit of the soil is decreased, the plastic limit of the soil is increased, and the plasticity of the soil is decreased. The group index value of the soil is evaluated, and it was found that with the addition of PKSA GI value of the soil is decreased, which indicates the strength of the soil is improved.

Keywords: palm kernel shell ash, black cotton soil, liquid limit, group index, plastic limit, plasticity index

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Authors: J. R. Wang, H. C. Chang, A. L. Ho, J. H. Yang, S. W. Chen, C. Shih

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The purpose of the study is to analyze the load rejection transient of ABWR by using TRACE, PARCS, and SNAP codes. This study has some steps. First, using TRACE, PARCS, and SNAP codes establish the model of ABWR. Second, the key parameters are identified to refine the TRACE/PARCS/SNAP model further in the frame of a steady state analysis. Third, the TRACE/PARCS/SNAP model is used to perform the load rejection transient analysis. Finally, the FSAR data are used to compare with the analysis results. The results of TRACE/PARCS are consistent with the FSAR data for the important parameters. It indicates that the TRACE/PARCS/SNAP model of ABWR has a good accuracy in the load rejection transient.

Keywords: ABWR, TRACE, PARCS, SNAP

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Authors: Joanna Maj, Awais Hussain, Lyndsey Vu, Catherine Roxas

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Background: Bone injuries in babies are common conditions that arise during delivery. Fractures of the clavicle, humerus, femur, and skull are the most common neonatal bone injuries sustained from labor and delivery. During operative deliveries, zealous tractions, ineffective delivery techniques, improper uterine incision, and inadequate relaxation of the uterus can lead to bone fractures in the newborn. Neonatal anatomy is unique. Just as children are not mini-adults, newborns are not mini children. A newborn’s anatomy and physiology are significantly different from a pediatric patient's. In this paper, we describe common orthopedic trauma in newborn babies. We provide a comprehensive overview of the different types of bone injuries in newborns. We hypothesize that the rate of bone fractures sustained at birth is higher in cases of operative deliveries. Methods: Relevant literature was selected by using the PubMed database. Search terms included orthopedic conditions in newborns, neonatal anatomy, and bone fractures in neonates during operative deliveries. Inclusion criteria included age, gender, race, type of bone injury and progression of bone injury. Exclusion criteria were limited in the medical history of cases reviewed and comorbidities. Results: This review finds that a clavicle fracture is the most common type of neonatal orthopedic injury sustained at birth in both operative and non-operative deliveries. We confirm the hypothesis that infants born via operative deliveries have a significantly higher rate of bone fractures than non-cesarean section deliveries. Conclusion: Newborn babies born via operative deliveries have a higher rate of bone fractures of the clavicle, humerus, and femur. A clavicle bone fracture in newborns is most common during emergency operative deliveries in new mothers. We conclude that infants born via an operative delivery sustained more bone injuries than infants born via non-cesarean section deliveries.

Keywords: clavicle fracture, humerus fracture, neonates, newborn orthopedics, orthopedic surgery, pediatrics, orthopedic trauma, orthopedic trauma during delivery, cesarean section, obstetrics, neonatal anatomy, neonatal fractures, operative deliveries, labor and delivery, bone injuries in neonates

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Authors: Mohammad Arshad Ikram

Abstract:

We report three cases of challenging fractures in children treated by intramedullary fixation using the Metaizeau method and achieved anatomical reduction with excellent clinical results. Jean-Paul Metaizeau described the centromedullary fixation for the radial neck in 1980 using K-wires Radial neck fractures are uncommon in children. Treatment of severely displaced fractures is always challenging. Closed reduction techniques are more popular as compared to open reduction due to the low risk of complications. Metaizeau technique of closed reduction with centromedullary pinning is a commonly preferred method of treatment. We present two cases with a severely displaced radial neck fracture, treated by this method and achieved sound union; anatomical position of the radial head and full function were observed two months after surgery. Proximal humerus fractures are another uncommon injury in children accounting for less than 5% of all pediatric fractures. Most of these injuries occur through the growth plate because of its relative weakness. Salter-Harris type I is commonly seen in the younger age group, whereas type II & III occurs in older children and adolescents. In contrast to adults, traumatic glenohumeral dislocation is an infrequently observed condition among children. A combination of proximal humerus fracture and glenohumeral dislocation is extremely rare and occurs in less than 2% of the pediatric population. The management of this injury is always challenging. Treatment ranged from closed reduction with and without internal fixation and open reduction with internal fixation. The children who had closed reduction with centromedullary fixation by the Metaizeau method showed excellent results with the return of full movements at the shoulder in a short time without any complication. We present the case of a child with anterior dislocation of the shoulder associated with a complete displaced proximal humerus metaphyseal fracture. The fracture was managed by closed reduction and then fixation by two centromedullary K-wires using the Metaizeau method, achieving the anatomical reduction of the fracture and dislocation. This method of treatment enables us to achieve excellent radiological and clinical results in a short time.

Keywords: glenohumeral, Metaizeau method, pediatric fractures, radial neck

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Authors: Armin Shirbazo, Hamed Lamei Ramandi, Mohammad Vahab, Jalal Fahimpour

Abstract:

Hydraulic fracturing, especially multi-stage hydraulic fracturing, is a practical solution for wells with uneconomic production. The wide range of applications is appraised appropriately to have a stable well-production. Production logging tool, which is known as PLT in the oil and gas industry, is counted as one of the most reliable methods to evaluate the efficiency of fractures jobs. This tool has a number of benefits and can be used to prevent subsequent production failure. It also distinguishes different problems that occurred during well-production. In this study, the effectiveness of hydraulic fracturing jobs is examined by using the PLT in various cases and situations. The performance of hydraulically fractured wells is investigated. Then, the PLT is employed to gives more information about the properties of different layers. The PLT is also used to selecting an optimum fracturing design. The results show that one fracture and three-stage fractures behave differently. In general, the one-stage fracture should be created in high-quality areas of the reservoir to have better performance, and conversely, in three-stage fractures, low-quality areas are a better candidate for fracturing

Keywords: multi-stage fracturing, horizontal well, PLT, fracture length, number of stages

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Authors: Martin Cermak, Tomas Karasek, Jaroslav Rojicek

Abstract:

The key role in phenomenological modelling of cyclic plasticity is good understanding of stress-strain behaviour of given material. There are many models describing behaviour of materials using numerous parameters and constants. Combination of individual parameters in those material models significantly determines whether observed and predicted results are in compliance. Parameter identification techniques such as random gradient, genetic algorithm, and sensitivity analysis are used for identification of parameters using numerical modelling and simulation. In this paper genetic algorithm and sensitivity analysis are used to study effect of 4 parameters of modified AbdelKarim-Ohno cyclic plasticity model. Results predicted by Finite Element (FE) simulation are compared with experimental data from biaxial ratcheting test with semi-elliptical loading path.

Keywords: genetic algorithm, sensitivity analysis, inverse approach, finite element method, cyclic plasticity, ratcheting

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Authors: Daniel Francis, Mo Yassin

Abstract:

Transverse patella fractures are routinely fixed using tension band wiring (TBW) using Kirschner wires and a wire in the shape of a figure of 8. The idea of the study was to compare the outcomes of the traditional technique against the more recently used cannulated screws and fiber tape in the shape of a figure of 8. We performed a retrospective cohort study of all the surgically fixed patella fractures from the year 2019 to 2022. The patients were divided into two groups TBW group and cannulated screws group. The primary outcome measure was the failure of fixation and the need for the removal of metalwork. Twenty-six patellar fractures were studied. TBW was used in 14 (53.8%), and cannulated screws were used for fixation in 12 (46.2%). There was one incident of metalwork failure in the TBW and one incident in the cannulated screws group. Five (35.7%) of patients in the TBW needed symptomatic metal work removed and One (8.3%) in the cannulated screw group. In both groups, the rate of fixation failure was low. Symptomatic implants, the most common complication observed, were higher in the TBW group in our practice. Although the small numbers in both groups, the hope of this study is to shine the light on the use of cannulated screws for patella fractures as it would reduce the need for a second operation and reduce the load on the already stretched services as well as improving the patient experience by not requiring further surgery. Although this is not a brand-new technique, it is not commonly used as there have not yet been any studies that demonstrate the lower rates of second surgery needed.

Keywords: patella, tension band wiring, randomised, new technique

Procedia PDF Downloads 56

Authors: Phuong Nguyen

Abstract:

Along with the ongoing energy transition, the electrical power system is getting more vulnerable with the increasing penetration of renewable energy sources (RES). By replacing a large amount of fossil fuel-based power plants with RES, the rotating mass of the power grid is decreasing drastically, which has been reported by a number of system operators. This leads to a huge challenge for operators to secure the operation of their grids in all-time horizon ranges, from sub-seconds to minutes and even hours. There is a need to revise the grid capabilities in dealing with transient (angle) stability and voltage dynamics. While the traditional approaches relied on deterministic scenarios (worst-case scenarios), there is also a need to cover a whole range of probabilities regarding a wide range of uncertainties coming from massive RES units. To contribute to handle these issues, this paper aims to focus on developing a new analytical approach for transient stability.

Keywords: transient stability, uncertainties, renewable energy sources, analytical approach

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Authors: Ya-Chi Yu, Pei-Syuan Ruan, Shao-Wen Chen, Yu-Hsien Chang, Jin-Der Lee, Jong-Rong Wang, Chunkuan Shih

Abstract:

This study analyzed the transient signals of central region void fraction of air-water two-phase flow in a 3x3 rod bundle. Experimental tests were carried out utilizing a vertical rod bundle test section along with a set of air-water supply/flow control system, and the transient signals of the central region void fraction were collected through the electrical conductivity sensors as well as visualized via high speed photography. By converting the electric signals, transient void fraction can be obtained through the voltage ratios. With a fixed superficial water velocity (J_f=0.094 m/s), two different superficial air velocities (J_g=0.094 m/s and 0.236 m/s) were tested and presented, which were corresponding to the flow conditions of bubbly flows and cap/slug flows, respectively. The time averaged central region void fraction was obtained as 0.109-0.122 with 0.028 standard deviation for the selected bubbly flow and 0.188-0.221with 0.101 standard deviation for the selected cap/slug flow, respectively. Through Fast Fourier Transform (FFT) analysis, no clear frequency peak was found in bubbly flow, while two dominant frequencies were identified around 1.6 Hz and 2.5 Hz in the present cap/slug flow.

Keywords: central region, rod bundles, transient void fraction, two-phase flow

Procedia PDF Downloads 167

Authors: A. Hadadi, M. Abdollahi, A. Dustmohammadi

Abstract:

The growing use of DGs in distribution networks provide many advantages and also cause new problems which should be anticipated and be solved with appropriate solutions. One of the problems is transient voltage drop and short circuit in the electrical network, in the presence of distributed generation - which can lead to instability. The appearance of the short circuit will cause loss of generator synchronism, even though if it would be able to recover synchronizing mode after removing faulty generator, it will be stable. In order to increase system reliability and generator lifetime, some strategies should be planned to apply even in some situations which a fault prevent generators from separation. In this paper, one fault current limiter is installed due to prevent DGs separation from the grid when fault occurs. Furthermore, an innovative objective function is applied to determine the impedance optimal amount of fault current limiter in order to improve transient stability of distributed generation. Fault current limiter can prevent generator rotor's sudden acceleration after fault occurrence and thereby improve the network transient stability by reducing the current flow in a fast and effective manner. In fact, by applying created impedance by fault current limiter when a short circuit happens on the path of current injection DG to the fault location, the critical fault clearing time improve remarkably. Therefore, protective relay has more time to clear fault and isolate the fault zone without any instability. Finally, different transient scenarios of connection plan sustainability of small scale synchronous generators to the distribution network are presented.

Keywords: critical clearing time, fault current limiter, synchronous generator, transient stability, transient states

Procedia PDF Downloads 170