Middle Of Wall Research Articles

Research on Construction Sequences and Construction Methods of the Small Clear-Distance, Double-Arch Tunnel under an Asymmetrical Load

A small clear-distance, double-arch tunnel under an asymmetrical load combines the characteristics of small clear-distance, tunnels and double-arch tunnels, and the influence of an asymmetrical terrain must be considered. Its construction stability is a problem worth studying. This paper used the Wengcun tunnel as the engineering background. Midas/GTS finite element analysis software was used to study the effects of eight excavation sequences and two excavation methods on tunnel stability. The results showed that the deformation and force of the tunnel were asymmetric under the asymmetrical terrain. Both middle partition walls were deformed towards the shallowly buried side, and the shallowly buried side was deformed to a greater extent. Excavating shallow side tunnels first can effectively mitigate the impact of asymmetric terrain. The arch settlement of the Center Diaphragm Excavation Method is 1.33 cm, which is smaller than the three-step excavation method of 1.48 cm; however, this difference is not significant. The Three-bench Excavation Method was more efficient. Based on the conclusion of a numerical simulation, the construction site adopted the construction sequence of excavating the shallowly buried side tunnel first and adjusted the excavation method to the Three-bench Excavation Method.

Follicular cholangitis mimicking a common bile duct cancer: a case report

BackgroundFollicular cholangitis (FC) is a benign bile duct disease that was first reported 2003. Pathologically, it is characterized by lymphoplasmacytic infiltration with multiple lymphoid follicle formations under the mucosal layer of the biliary tract. However, as this disease is extremely rare, little is known about its etiology and pathogenesis.Case presentationA 77-year-old woman was diagnosed with middle bile duct stenosis and potential increases in alkaline phosphatase (ALP) and γ-glutamyl transpeptidase levels (γ-GTP). Carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9) and IgG4 levels were all within the normal limits. Contrast-enhanced computed tomography (CE-CT) and magnetic resonance imaging (MRI) revealed bile duct dilation from intrahepatic to upper common bile duct and an irregular mass lesion in distal bile duct. Additionally, multiple overlapping leaf-like folds were detected. 18F-fluorodeoxyglucose positron emission tomography–computed tomography (18F-FDG-PET/CT) did not demonstrate fluorodeoxyglucose uptake. Subtotal stomach-preserving pancreaticoduodenectomy with regional lymph node dissection was performed because common bile duct cancer could not be ruled out. The resected specimen showed diffuse homogeneous middle bile duct wall thickening. Microscopically, the lesion exhibited thick fibrosis with several invaded lymphoplasmacytic cells, and lymphoid follicle formations were detected under the mucosal layer. Immunohistochemical staining (IHC) revealed positive for CD3, CD4, CD20 and CD79a, and these findings led to a final diagnosis of FC. The patient has not experienced recurrence to date (42 months postoperatively).ConclusionsCurrently, accurate preoperative diagnosis of FC is difficult. More cases must be accumulated to generate additional knowledge on its precise diagnosis and proper treatment.

Response of buried box-shaped road tunnel against internal BLEVE and its damage mitigation

Box-shaped road tunnels have been widely used in urban areas and might face the threats of accidental Boiling Liquid Expansion Vapor Explosions (BLEVEs) due to ever-increasing liquified petroleum transportation. However, very limited study has investigated the response of popularly used buried box-shaped road tunnels (i.e., box-shaped tunnels buried in soil mass) subjected to internal BLEVEs. In this study, the dynamic response of a typical two-cell box-shaped road tunnel buried in soil subjected to internal BLEVEs induced by the burst of a 20 m3 liquified petroleum gas (LPG) tank is numerically investigated by using LS-DYNA. The results show that the tunnel experiences severe damage under BLEVEs with liquid-filling ratios equal to or more than 65% while it suffers only minor damage with the load carrying capacity not compromised under BLEVE with 50% filled-liquid. The effects of BLEVE occurring locations on the tunnel response are then investigated. It is found that the tunnel subjected to the BLEVE occurring on the lane near middle wall experiences more significant response in general than that away from the middle wall. In addition, to mitigate the tunnel damage under BLEVEs, strengthening soil mass around the tunnel using soil–cement mixture is considered and its performance is examined. An empirical formula is also proposed for the design of using soil–cement mixture to enhance the buried box-shaped tunnel against internal BLEVEs.

Investigation of Linear Dynamic Analysis and Duc-tile Design of High Rise Structure as per Revised Indian Code

Abstract: This thesis gives a comparative seismic analysis of high rise structure in zone III and zone IV using the New IS 13920- 2016 standards. The recent earthquakes in India revealed unequivocally that conventional structural design and construction techniques fail to meet fundamental seismic resistance standards. The use of ductile design and detailing methods in conventional construction is a critical topic that requires attention. The ductility of reinforced concrete structures as a whole is a difficult topic. However, specific design factors and reinforcing details may be used in particular critical spots of the building structure to reduce seismic damage and life-threatening collapse. The approaches are straightforward, affordable, and extensively detailed in the Indian Bureau of Standard Code of Practice's standard code of practise (IS13920). It is recommended to conduct a comparative analysis of the dynamic behaviour of high-rise structures using the response spectrum approach in accordance with IS 1893 Part1-2016 The investigation of characteristics including displacement, base shear, and tale drift. Examining factors including modal frequencies and acceleration in response spectrum load instances in both the X and Y directions. Ductile design of high rise structures in accordance with IS 13920-2016's new codal requirements. Additionally, it is recommended to analyse and design multi-story buildings using computational software such as ETABS and compare characteristics such as storey displacement, base shear and storey drift. The shear wall at the corner reduces storey X displacement by 46.245%. The intermediate shear wall reduces displacement by 54.617%. The central shear wall reduces displacement by 68.72%. Lower level shear wall displacement is central. Shear wall at corner reduces storey drift in X direction by 49.374%. Shear wall at centre reduces drift by 39.716%. Shear wall at centre reduces drift by 2.638%. Lower story drift in central shear wall. Shear wall at corner base shear drift is 63.646% greater than without shear wall. Base shear is 64.006% higher with a middle shear wall. Shear wall at the centre increases base shear by 65.765%. Center shear wall has stronger base reaction.

SGRT-based DIBH radiotherapy practice for right-sided breast cancer combined with RNI: A retrospective study on dosimetry and setup accuracy.

We retrospectively studied the dosimetry and setup accuracy of deep inspiration breath-hold (DIBH) radiotherapy in right-sided breast cancer patients with regional nodal irradiation (RNI) who had completed treatment based on surface-guided radiotherapy (SGRT) technology by Sentinel/Catalyst system, aiming to clarify the clinical application value and related issues. Dosimetric indicators of four organs at risk (OARs), namely the heart, right coronary artery (RCA), right lung, and liver, were compared on the premise that the planning target volume met dose-volume prescription requirements. Meanwhile, the patients were divided into the edge of the xiphoid process (EXP), sternum middle (SM), and left breast wall (LBW) groups according to different positions of respiratory gating primary points. The CBCT setup error data of the three groups were contrasted for the treatment accuracy study, and the effects of different gating window heights on the right lung volume increases were compared among the three groups. Compared with free breath (FB), DIBH reduced the maximum dose of heart and RCA by 739.3±571.2 cGy and 509.8±403.8 cGy, respectively (p<0.05). The liver changed the most in terms of the mean dose (916.9±318.9 cGy to 281.2±150.3 cGy, p<0.05). The setup error of the EXP group in the anterior-posterior (AP) direction was 3.6±4.5mm, which is the highest among the three groups. The right lung volume increases in the EXP, SM, and LBW groups were 72.3%, 69.9%, and 67.2%, respectively (p=0.08), and the corresponding breath-holding heights were 13.5±3.7mm, 10.3±2.4mm, and 9.6±2.8mm, respectively (p<0.05). SGRT-based DIBH radiotherapy can better protect the four OARs of right-sided breast cancer patients with RNI. Different respiratory gating primary points have different setup accuracy and breath-hold height.

Numerical study of periodically heated wall effect on natural convection in an enclosure

The present numerical study focuses on sinusoidal heating and aspect ratio effects on heat flow of free convection of fluid inside the enclosure. The side walls are maintained at ambient temperature and the middle horizontal wall that divides the enclosure evenly is heated to sinusoidal temperature and the other horizontal walls are adiabatic. The numerical solution of the transport equations is done by the finite difference method to determine the heat transfer and thermal penetration with respect to aspect ratio, sinusoidal frequency and Rayleigh number. The numerical results of heat and fluid flow in the range of controlled governing parameters such as Rayleigh number (Ra = 105), sinusoidal frequency (1 ⩽N⩽ 4 ) and aspect ratio (0.2 ⩽A⩽ 4) are analysed in terms of streamlines, isotherms, heat penetration length and Nusselt number. It has been found that the 100% thermal penetration in the upper part of the enclosure of the aspect ratio A = 1 is obtained on continuous heating, while in the lower section, the maximum thermal penetration is limited to 98%, which is obtained on non-continuous heating in the enclosure of aspect ratio A = 0.2, 0.5.

Clinical and Radiological Evaluation of a Self-Condensing Bone Implant in One-Stage Sinus Augmentation: A 3-Year Follow-Up Retrospective Study.

Stabilization of dental implants in the sinus region with a bone height below 4 mm gen-erally requires a two-stage sinus floor elevation surgery. To improve this aspect, the aim of this retrospective study was to demonstrate the feasibility of performing a one-stage maxillary sinus augmentation using an innovative self-condensing implant design, even in case of a bone height close to 2 mm. Clinical and radiological outcomes from 54 patients (26 females; 28 males; 69 total implants positioned) were analyzed 3 years post-surgery. The three-dimensional grafts change was evaluated by Cone-Beam Computed Tomography (CBCT) before surgery (T0), immediately after surgery (T1), and 1-year post-surgery (T2). The sinus floor levels measured at the medial (M-W), middle (MD-W), and lateral (L-W) walls reported: M-W of 1.9 ± 2.4 mm (T1) and 1.7 ± 2.6 mm (T2); MD-W of -0.1 ± 2.7 mm (T1) and 0.7 ± 2.4 mm (T2); L-W of 3.1 ± 3.0 mm (T1) and 3.1 ± 3.0 mm (T2); besides a bone crest height (C-F) of 4.6 ± 2.0 mm (T1) and 12.1 ± 1.4 mm (T2). Moreover, after 3 years only 1 implant was lost, and so an implant survival rate of 98.55% was recorded. In conclusion, these results suggest the efficacy of using this implant design for a one-stage sinus lift approach, not only in terms of increased implant survival rate and decreased marginal bone loss, but also for its potential applicability in case of reduced bone height.

Bacterial diversity associated with volatile compound accumulation in pit mud of Chinese strong-flavor baijiu pit

Pit mud quality is a key parameter that impacts the quality of Chinese strong-flavor Baijiu production.This study was developed to explore spatial bacterial community distributions and the relationships between these distributions and the volatile compound accumulation within the pit mud used in the production of Chinese strong-flavor Baijiu. The results revealed Lactobacillus pasteurii and Limnochorda pilosa were found to be the dominant bacteria present in the upper wall, middle wall, and bottom pit mud layers, whereas the Clostridium genus was detectable at high levels in the lower layer of the pit wall and played a role in contributing to the overall aroma and flavor compounds in produced Chinese strong-flavor Baijiu, with Clostridium abundance being strongly correlated with caproic acid, ethyl caproate, ethyl butyrate, and hexanol levels as well as moderately correlated with butyric acid levels. The abundance of the Lactobacillus genus was positively correlated with levels of ethyl lactate, 1-butanol, and 2,3-butanediol. Limnochorda pilosa was closely associated with ethyl acetate levels. Additionally, the correlations between bacterial communities and chemical properties also investigated, and the results demonstrated PO43−, total carbon, K+, humus, NH4+-N, and Mg2+ levels significantly affected the bacterial community structure of pit mud, and they were positively correlated with the relative abundance of Clostridium. Together, these findings can serve as a foundation for future studies exploring the mechanisms whereby volatile compounds accumulate in different pit mud layers, which facilitates the fermentation regulation and pit mud quality improvement of Chinese strong-flavor Baijiu.

Influence of Pipe-Jacking Reaction on Earth Pressure of Back Wall of Pilot Tunnel of Subway Station

The study of the distribution form and calculation method of the earth pressure on the back wall of a pilot tunnel under a jacking reaction is very important to ensure the safety and smooth construction of the pipe jacking. Based on a metro station in Shenyang, this paper firstly investigates the effects of the changes in the jacking reaction parameters, such as the loading intensity, loading position, and loading area on the earth pressure and the displacement of the back wall in a pilot tunnel through numerical simulation, and then proposes a formula for calculating the soil reaction on the back wall and verifies it by comparison with the FEA (finite element method) results. The results show that the earth pressure distribution pattern of the back wall is similar to the normal distribution curve under the action of the jacking reaction. The horizontal displacement and earth pressure of the back wall will gradually increase with the increase in the jacking reaction. The horizontal displacement of the back wall is greatest when the load is applied to the middle wall, followed by the top wall and the bottom wall. The maximum horizontal displacement is reduced by approximately 24.25% when the loading position changes from the middle to the bottom. As the loading area increases, the maximum horizontal displacement of the back wall decreases, in the order of 11.8% and 14.45% relative to the previous level. The earth pressure of the back wall also decreases, in the order of 17.92% and 22.76% relative to the previous level. The equations presented are applicable to the calculation of the soil reaction in the limit state.

Variant analysis of financial and energy efficiency of the heat recovery system and domestic hot water preparation for a single-family building: The case of Poland

Significant amounts of waste heat are deposited in wastewater, which can be used e.g. for heating domestic water. The aim of the paper was to analyze the efficiency of energy recovery from gray water using a new horizontal heat exchanger in the form of a linear drainage equipped with a wavy middle wall. The experimental research consisted of the analysis of efficiency of the device prototype, and then the calculation of energy savings for the preparation of domestic hot water for 81 test cases. Installations cooperating with an electric and gas water heater were analyzed. A Life Cycle Cost analysis was carried out for the financial effectiveness of a conventional installation and an installation equipped with a heat exchanger for a family of 3. Research have shown that the new heat exchanger reduces energy consumption for hot water preparation by an average of 22–31%. It was established that when using an electric water heater, the investment costs pay back in the period of 4–9 years, and in the case of a gas heater, at least 12 years. The sensitivity analysis showed that an increase in energy prices can significantly shorten the payback period, to 6 years for a gas heater and 2 years for an electric heater. Research has shown that the new heat exchanger can significantly reduce the amount of energy needed to prepare domestic hot water. The research results can be useful for researchers, designers and potential users of heat recovery systems.

Neuroinflammatory Disease Responsive to MEK-Inhibitor

Objective Illustrate that some neuroinflammatory diseases may respond best to antiproliferative therapies rather than immunomodulatory therapies. Background Genomics are increasingly employed in the diagnostic armamentarium of refractory neuro-inflammatory diseases. Metagenomic next-generation sequencing is used to detect pathogens and germline genetic testing is used to detect inborn errors of the immune system. Genetic testing of tissue can identify somatic mutations for targeted treatment. MEK-inhibitors are an emerging treatment for RAS/MAPK pathway mutated diseases which include some neuro-inflammatory mimics like neuro-histiocytoses. Design/Methods NA. Results Previously healthy 12-year-old girl presented with 1 month of diplopia and headaches. Her brother has clinically diagnosed NF1 (café-au-lait macules, cutaneous neurofibromas). Exam notable for right third nerve palsy. MRI showed T2/FLAIR hyperintense lesions of the right temporal lobe, basal ganglia, and cervical through thoracic cord, nodular leptomeningeal enhancement along the entire spinal cord, and right middle cerebral artery vessel wall enhancement. CSF: WBC 6/mm3 (62% lymphocytes 37% monocytes), protein 133 mg/dL. She improved with pulse methylprednisolone and maintenance steroids. At 5 months, she developed malignant elevated intracranial pressure with CSF OP &gt;50 cm water, bradycardia, and encephalopathy requiring weekly LPs. Brain biopsy showed astrocytic and microglial activation without significant inflammation. No histiocytes were noted. There was no evidence of neoplasia or infection. She was tried on anakinra. At 6 months, she developed left third nerve palsy and seizures. For weeks, she required daily LPs for intracranial hypertension despite placement of ventriculoperitoneal shunt. Additional treatments included infliximab, steroids, and siltuximab. NGS from brain biopsy identified 2 NF1 mutations (nonsense, splicing). Allele fractions: 6% and 9%. Her mental status and need for frequent LP improved dramatically with trametinib. Conclusions This case illustrates the importance of considering somatic genomic testing of neural tissue even when the neuropathology is not suggestive of a malignancy or histiocytosis as this can inform newer molecularly targeted therapeutic options.

Evaluation of Gigantochloa scortechinii and soil interaction in three study sites in Malaysia

Understanding the productivity and physiological status of an organ (rhizome) function can lead into a sustainable production of sympodial bamboo. Nutrient elements and ash content (AC) are among the indicators to indicate the productivity and physiological status of an individual bamboo organ. The present study aimed to (a) determine the concentration of macronutrient elements of Gigantochloa scortechinii's rhizomes at four different ages collected at three study sites, and (b) investigate their relationship with AC. The destructive sampling was conducted on a set of four consecutive rhizomes using the selective random sampling method. Middle rhizome wall portion was used to determine the macronutrient elements and AC. All primary and secondary macronutrients were found to be different (p ≤ 0.01) at different study sites, except for the magnesium (Mg). The changes in nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and Mg from new sprout to mature rhizome showed a strongly positive relationship with AC. Thus, the N, P, K, Ca, and Mg concentrations decreased with rhizome age, resulting in a decrease in AC. The present study suggests that the suitable harvesting of individual bamboo culm and rhizome is at mature and older age while the remaining younger age bamboo is kept being grown so that the bamboo production is sustainable in terms of the physiological functions.

Usefulness of Cardiac Magnetic Resonance Imaging in Patients with Neuromuscular Dystrophies (Duchenne/Becker Muscular Dystrophy)

Background: Cardiac magnetic resonance imaging (CMR) is commonly used in patients with Duchenne (DMD) and Becker (DMB) Neuromuscular Dystrophies. Late gadolinium enhancement (LGE) identifies areas of middle, subepicardial, or subendocardial wall fibrosis, and volumetric left ventricular ejection fraction (LVEF) is considered the gold standard in the diagnosis and prognosis of these dystrophies. Myocardial fibrosis occurs in patients with neuromuscular dystrophies. Objectives: The purposes of our study were to determine the presence of cardiac fibrosis using CMR, to determine neuromuscular and cardiac involvement, and to evaluate the cardiovascular outcomes of these patients. Material y métodos: A descriptive cross-sectional study of 16 consecutive patients was conducted from March 2021 to July 2022 in the Cardiac Imaging Service of Diagnóstico Médico and CEMET- Tucumán. Results: A total of 16 patients were evaluated, 100% of them with confirmed diagnosis of DMD/DMB by laboratory, enzymes and genetic tests. Mean age was 19 years. All patients had severe stage of the Vignos Scale and were under neurological treatment. All patients were also treated with beta-blockers or angiotensin-converting enzyme inhibitors. CMR revealed severe LVEF impairment &lt;35% in 4 patients, segmental or global left ventricular (LV) wall motion disorders in 8 patients, and variable distribution pattern (diffuse, mesocardial, subendocardial and subepicardial patterns) of LGE in 12 patients. Non-compacted myocardium was observed in 6, and mild pericardial effusions in 2 patients. Conclusion: CMR should be included as a screening method in patients with neuromuscular dystrophies. Its contribution to clinical, echocardiographic and therapeutic staging is of utmost importance

Fungal Diversity Profiles in Pit Mud Samples from Chinese Strong-Flavour Liquor Pit.

Pit mud, a specific fermented soil, is an essential material for the fermentation of Chinese strong-flavour liquor. However, few studies to date have sought to characterize the spatial profiles of pit mud fungal communities in fermentation cellars from Chinese strong-flavour liquor distilleries. In this analysis, differences in fungal community structures and physicochemical properties in pit mud samples from different spatial positions within fermentation cellars were analyzed, revealing unique characteristic multidimensional pit mud fungal community profiles. Penicillium roqueforti, Pichia kudriavzevii, Aotearoamyces nothofagi, Penicillium robsamsonii, Alternaria arborescens, Trichosporon insectorum, Seltsamia ulmi, Trichosporon coremiiforme, Malassezia restricta were dominant in the pit mud samples form the upper cellar wall, whereas Metarhizium frigidum, Calonectria pseudoreteaudii, Penicillium clavigerum, Fusarium equiseti, Simplicillium chinense, Aspergillus intermedius, Trichosporon coremiiforme, Fusarium circinatum, Alternaria radicina, Aspergillus heterocaryoticus were predominant in the middle cellar wall. Alternaria radicina, Cladosporium chasmanthicola, Alternaria helianthiinficiens, Penicillium argentinense, Antarctomyces psychrotrophicus, and Trichosporon inkin are majorly present in the down cellar wall layer. Bipolaris axonopicola, Ramgea ozimecii, Penicillium argentinense, Calonectria queenslandica, Metarhizium robertsii, and Penicillium roqueforti were identified as the dominant fungi in pit mud samples from the cellar bottom. Additionally, Alternaria destruens and Alternaria doliconidium are present at notably high levels in all layers of pit mud samples. Moisture, pH, PO43-, acetic acid, humus, K+, Mg2+, Ca2+, butyric acid, and caproic acid levels in these different pit mud positions exhibited a rising incremental pattern from the upper wall layer to the bottom layer, whereas lactic acid levels were significantly lower in the bottom pit mud layer relative to these other layers. Moisture, pH, and NH4+-N were identified as the three most significant factors associated with fungal community composition through a redundancy analysis. Overall, these findings may offer a theoretical foundation for future efforts to improve or standardize artificial pit mud.

An Unusual Case of Chest Pain and Pyrexia

Question: A 44-year-old man with tearing retrosternal pain for 2 weeks was admitted to our department. A day before the onset of symptoms, he had pharyngalgia, cough, sputum production, moderate pyrexia, and fatigue, which he thought was due to a common cold. He then had sudden-onset severe chest pain, which lasted 4 to 6 seconds and occurred every 30 seconds, with acid reflux and heartburn. The patient had consumed nothing after the start of the symptoms until this consultation. He denied emesis, hematemesis, melena, dysphagia, odynophagia, history of esophageal disease, eating hurriedly, ingestion of hot or rough food, anticoagulants, or foreign body. His medical history was significant for alcohol consumption (100 g/d) for more than 20 years. He visited a local hospital and underwent chest computer tomography (CT); however, the diagnosis was unclear, and an attempt to insert a nasogastric tube failed. The patient visited another hospital, and a CT scan revealed dilation of the esophageal lumen and thickening of the esophageal wall, with exudation in the periesophageal areas and lung fields. Esophagoscopy revealed a large depressed lesion at 20 cm from the incisors, measuring 1 cm in diameter and covered with pus. The background esophageal mucosa was severely inflamed and edematous. Contrast esophagography performed a week later showed accumulation of contrast medium in the middle and lower esophagus, which formed a sac-like shadow beside the esophagus, without communication with the thoracic or gastric cavity. The patient was treated conservatively, and his symptoms were partially relieved. Because the pathogenesis was still unknown, the patient was referred to our institution for further evaluation. What is the correct diagnosis and management of this condition? See the Gastroenterology website (www.gastrojournal.org) for more information on submitting to Gastro Curbside Consult According to his medical history from other hospitals, normal electrocardiography and cardiac enzyme levels excluded the diagnosis of myocardial infarction; absence of hypertension and no abnormalities in aortic anatomy disclosed by means of contrast CT argued against aortic dissection; absence of emesis and no extravasation of contrast medium demonstrated by contrast esophagography excluded Boerhaave’s syndrome. Then contrast chest CT scan, which revealed thickening and liquid accumulation in the middle and lower esophageal wall, with little extra-esophageal air leakage and pneumonia (Figures A and B), and upper endoscopy (Figures C and D) were performed. A diagnosis of spontaneous intramural esophageal dissection (SIED) complicated by infectious esophagitis and pneumonia was made. SIED is a rare disease entity characterized by transverse and longitudinal separation of the mucosal and submucosal layers from the esophageal wall. Sudden onset of severe retrosternal chest pain, odynophagia, dysphagia, and hematemesis are the most common symptoms. Contrast esophagography and chest CT are the preferred methods to establish the diagnosis, and endoscopy also proved to be safe and useful in this condition. In most cases, conservative treatment has a good prognosis. Endoscopic interventions and surgery are alternative therapies when patients are refractory to conservative management or when complex complications occur.1Khil E.K. Lee H. Her K. Spontaneous intramural full-length dissection of esophagus treated with surgical intervention: multidetector CT diagnosis with multiplanar reformations and virtual endoscopic display.Korean J Radiol. 2014; 15: 173-177Crossref PubMed Scopus (4) Google Scholar,2Jung K.W. Lee O.J. Extensive spontaneous submucosal dissection of the esophagus: long-term sequential endoscopic observation and treatment.Gastrointest Endosc. 2002; 55: 262-265Abstract Full Text Full Text PDF PubMed Scopus (14) Google Scholar The patient was treated conservatively and discharged on day 35. Seven weeks later, follow-up endoscopy showed complete mucosal healing (Figure E), and he was asymptomatic at the time of writing (August 1, 2022).

Influence of the flow field and vortex structure of patient-specific abdominal aortic aneurysm with intraluminal thrombus on the arterial wall

ABSTRACT In this study, numerical simulations and experiments were conducted on patient-specific normal abdominal aorta and abdominal aortic aneurysm (AAA) with intraluminal thrombus (ILT) models, which were reconstructed from computed tomography angiography (CTA) images published online. A scale-adaptive simulation (SAS) of the abdominal aortic aneurysm with a posterior eccentric thrombus was performed and the reliability of the numerical simulation was verified by 2D particle image velocimetry (PIV) experimental results. The distribution of wall shear stress (WSS), oscillatory shear index (OSI), and relative residence time (RRT) of the normal abdominal aorta and AAA were compared and discussed systematically according to the numerical simulation results under rest and exercise conditions. Numerical results indicated that ILT deposition positions were accompanied by low WSS, high OSI, and high RRT regions and were characterized by small vortex groups, which was due to the fragmentation of large vortex structures. The distribution law of the AAA wall parameters has an obvious correlation with the nearby vortex structure formation, development, fragmentation and dissipation. It was also found that high TAWSS, low OSI, and low RRT regions present in the middle and lower aneurysm walls under exercise condition reduce the risk of ILT formation and development.

The Change in Dynamic Response Distribution of Double-Track Tunnel Structure Caused by Adding Middle Partition Wall

Adding a middle partition wall is an effective method to prevent the interaction between the upper and lower subway lines in a double-track tunnel, and the subsequent change in the dynamic response of the tunnel structure caused by adding a middle partition wall has drawn attention. We analyzed the displacement and acceleration responses of the upper part (zone A), the lower part (zone B), the tunnel bed and the surrounding connecting part (zone C) of the double-track tunnel by establishing a two-dimensional finite element model of the double-track tunnel and soil with and without a middle partition wall. The numerical results demonstrate that the addition of the middle partition wall improves the displacement and acceleration response distribution of the double-track tunnel structure. Compared with single-train traffic, the addition of the middle partition wall brings more obvious changes to the dynamic response of the double-track tunnel during double-train traffic. The maximum displacement response decreases from 5.881 mm to 5.335 mm, and the maximum acceleration response decreases from 18.51 m/s2 to 16.62 m/s2. The displacement response value in the upper part increases from 1.0 mm to 1.5 mm, the acceleration response value increases from 3.0 m/s2 to 4.6 m/s2, the displacement response value in the tunnel bed and the surrounding connecting part decreases from 5.0 mm to 3.0 mm, and the acceleration response value in the tunnel bed and the surrounding connecting part decreases from 18.0 m/s2 to 10.0 m/s2. There is no obvious change in the lower part. During double-train traffic, after adding the middle partition wall, the horizontal displacement and horizontal acceleration response values of the double-track tunnel structure decrease by about 30% to 45%; the vertical displacement response value of the connection between the middle partition wall and the lining increases from 1.337 mm to 1.774 mm, an increase of 32.7%, and the vertical acceleration of the lower half of the tunnel lining is partially transferred to the upper half. The response values of horizontal displacement and acceleration in the middle part of the middle partition wall are the largest, at 1.6 mm and 6.0 m/s2, while the response values of vertical displacement and acceleration in the bottom of the partition wall are the largest, at 3.3 mm and 9.0 m/s2. The research results provide a reference for the structural design of middle partition walls to ensure the safety and stability of trains running in double-track tunnels.

Analysis of applying fin for charging process of phase change material inside H-shaped thermal storage

An H-shaped Double thermal storage unit has been studied numerically. A middle wall is sandwiched between two twin thermal storage cavities which are charging. The fins are attached to the middle wall to enhance the charging process. The set of equations modeling the charging process were solved using the Finite Element Method. The effects of different main parameters, namely thermal Fourier number, fin angle (symmetric cases) (−60 ≤ λ ≤ 60), 15 cases related to non-symmetric fin angle (−60 ≤ λl ≤ 60) and ( − 60 ≤ λr ≤ 60), and aspect ratio of fins (AR = 0.5–32) on the melting process of phase change material have been numerically studied. The results indicate that using fins for the cavity enhances the melting rate in the neighboring region due to the conductive heat transfer through the fins. Also, faster phase change material melting can be achieved by directing the fins upwards.

Vehicle-induced dynamic response characteristics of a new subway tunnel closely undercrossing the existing subway

Due to the limited underground space in the city, it is inevitable that the new subway may undercross the existing subway during the construction process. The current research mainly focuses on the dynamic response of single tunnel or the construction mechanics and ground motion response of tunnels with short-distance, while there is little research on the dynamic characteristics of subway tunnels undercrossing the existing subway with zero-distance. Therefore, in this paper, relying on a subway tunnel closely undercrossing the existing Line 1 with zero distance in Chengdu, using on-site test and numerical calculation, the vehicle-induced dynamic response characteristics of the new subway tunnel is analyzed under the moving train load of the existing Line 1, and the dynamic response differences of the new subway tunnel under different vehicle speeds and operation modes of the existing Line 1 is also discussed. The results show that the relationship between the acceleration of each part of the new subway tunnel is: roof > the middle wall > side wall > floor. For the horizontal acceleration, since the thickness of the side wall is larger than that of the middle wall, and the difference in the boundary constraints between the middle wall and side wall, the acceleration peak value of the middle wall is larger than that of the side wall. The dynamic response of the new subway increases with vehicle speeds, and the increasing rate of the vehicle speed in the range of 40–60 km/h is greater than that of 60–80 km/h. Compared with one-way operation, the two-way meeting has a certain superimposed effect on the acceleration response of the new subway tunnel and has the greatest impact on the acceleration response of the middle wall. The Fourier acceleration spectrum shows the strongest response around 60 Hz and 130 Hz. It is also found the operation of existing subway has adverse impact on the new subway, and certain vibration reduction measures should be taken to ensure the stability of new subway.

Centrifuge Model Investigation of Interaction between Successively Constructed Foundation Pits

A series of centrifuge model tests were conducted to study the interaction between successively constructed adjacent foundation pits. The stress, deformation, and earth pressure on retaining structures and the settlement of the soil between the two adjacent foundation pits during successive construction were investigated by a comprehensive instrumentation program. To reveal the effect of the construction sequence, both the stress and deformation of successively constructed foundation pits were compared. The results showed that the stress and deformation of the retaining structure in the foundation pit constructed first were larger than those in the foundation pit constructed later. Due to the inward displacement of the soil around the foundation pits excavated first, the first strut of the foundation pit constructed later underwent high tension during the construction of the first foundation pit. The lateral deformation of the retaining structure of the foundation pit excavated first increased with the increase of the excavation depth. However, the excavation of the second foundation pit reduced the earth pressure on the retaining wall between the two excavations, thus leading to the recovery of the inward deformation in the first excavation. However, the top of the retaining wall deformed into the first foundation pit during the whole construction. The settlement of the soil between the two foundation pits showed a superposition effect. During the construction of the two foundation pits, the settlement of the soil between them kept increasing. The active earth pressure on the middle wall of the foundation pit constructed later was lower than that on the middle wall of the first foundation pit. The excavation of the foundation pit constructed later had no significant effect on the passive earth pressure of the first foundation pit.