Cavity Wall Research Articles

Management of endometriosis: a call to multidisciplinary approach.

Endometriosis is defined as the presence of endometrial-like glands and stroma outside of the uterus. There are three types of endometriotic lesions: superficial or peritoneal endometriosis, ovarian endometrioma, and deep infiltrating disease. Endometriosis not only occurs in the pelvis but also can be found in extrapelvic sites such as the gastrointestinal tract, upper abdominal viscera, genitourinary tract, abdominal wall, diaphragm, and thoracic cavity. After thorough history and physical examination is performed, imaging, such as ultrasound or magnetic resonance imaging (MRI), should be obtained if there is high suspicion for deep-infiltrating endometriosis to better assess visceral involvement. Endometriosis can be suspected based on symptoms, physical examination findings, and imaging. However, a definitive diagnosis requires histopathologic confirmation. Treatment options include expectant, medical, and surgical management. Endometriosis is largely a quality-of-life issue, and treatment should be tailored accordingly with empiric medical therapy frequently utilized. Medical management focuses on symptom improvement. Surgical management with excision of endometriosis is preferred over ablation or fulguration of endometriotic lesions. In the case of deep or extrapelvic endometriosis, treatment with a multidisciplinary team with experience in the treatment of advanced-stage endometriosis is essential to minimizing morbidity and increasing long-term success.

Seismic Behavior Analysis of a 14th Century Anatolian Seljuk Kumbet

The preservation of cultural heritage and the seismic resilience of historic buildings are crucial for maintaining social identity, particularly in earthquake-prone regions. This study focuses on the modeling of Sırçalı Kumbet, a Seljuk monument built in the 14th century in Kayseri province, located in the Central Anatolia region of Turkey, using survey drawings and analysis using the finite element method (FEM) to evaluate its seismic performance. The analysis indicates that linear elastic calculation methods can serve as an initial approach for evaluating such geometrically complex structures. The findings demonstrate that Sırçalı Kumbet exhibits substantial structural rigidity, reducing deformation and enhancing resistance to material fatigue during seismic events. Displacement and stress analyses under G+EQx and G+EQy loading conditions reveal that tensile and compressive stresses remain within acceptable limits, with localized exceedances occurring at specific points, such as cavity corners and wall bases. While these localized stresses are manageable, they highlight areas that require continuous monitoring and potential reinforcement to ensure long-term stability. Additionally, the study suggests that the integration of regular maintenance and targeted reinforcement measures can further improve the monument’s durability and minimize potential damage. This research underscores the essential role of the FEM in bridging the gap between cultural heritage conservation and seismic resilience. It provides a methodological framework for integrating architectural, restoration, and engineering expertise into comprehensive conservation strategies. Future studies should expand this approach to include various building types and material properties to enhance the development of preservation strategies.

Unlocking the biological potential of methyl antcinate A: a new frontier in cancer and inflammation application.

Antrodia camphorata is a valued and scarce parasitic mushroom that exclusively proliferates on the inner cavity wall of the endangered tree Cinnamomum kanehirai Hay (Lauraceae), endemic to Taiwan. Historically, this fungus has been utilized in traditional medicine to treat liver cancer, diarrhea, abdominal pain, hypertension, and food and drug intoxication, among other ailments. Literature searches were performed in scientific databases. The results were compiled from peer-reviewed studies; the search was refreshed through January 2024 to incorporate the most recent research. In vitro studies have revealed that Antrodia camphorata possesses various pharmacological properties that prevent cancer, reduce inflammation, and improve liver function. This medicinal mushroom contains unique ergostane-type triterpenoids known as antcins, which exhibit numerous pharmacological properties. Seven naturally occurring methyl analogs of antcins have been identified so far. In this article, we reviewed and analyzed the properties of methyl antcinate A (MAA), a constituent of Antrodia camphorata and methyl derivative of antcin A. MAA has demonstrated important anti-apoptotic, anti-inflammatory, and gastro-protective properties, as well as significant anti-tumor, anti-cancer, and cytotoxic activities. The anti-cancer effect of MAA in various cancers is attributed to its ability to modulate signaling cascades in apoptotic pathways. A significant challenge is to initiate preclinical and clinical trials to assess its anti-tumor action in vivo, as this data is currently missing. Additionally, future research on the structure-activity relationship of antcins and their derivatives is expected to support their development as therapeutic agents for clinical use.

Experimental characterization of the in-plane shear strength of unreinforced masonry walls with damp-proof course and thermal break layer

Due to the highly demanding energy standards in Europe and challenging weather conditions, thermal break elements, such as aerated autoclaved concrete (AAC), have become increasingly popular in modern day residential buildings made of masonry cavity walls. Furthermore, a damp-proof course (DPC) layer is also used on top of the thermal break element to prevent water seeping and eventual entrapment due to capillary action. The presence of an AAC layer and of a DPC can have an adverse effect on the in-plane shear strength of a masonry wall, although information on this is barely available in the existing literature. This study aims at filling that knowledge gap through experimental investigations on traditional masonry walls and composite masonry walls, i.e. with an AAC and a DPC layer. The in-plane shear behaviour is compared between both types of wall specimens on the base of load-displacement curves and observation of failure modes. The capacity of analytical design approaches in predicting the test results has also been assessed. For the tested configurations, it can be concluded that the presence of AAC and DPC makes the failure mode switch from diagonal shear sliding combined with flexural toe crushing to horizontal shear sliding with crushing localized in the AAC layer, associated to a drop of the resistance by 6 to 9% depending on the type of clay units and mortar. The proposed analytical method, derived from EN 1996-1-1, is providing a safe estimate of the test results with a similar level of accuracy for traditional and composite configurations (predicted values in the range of 75 to 86% of the measured values). Finally, the influence of the definition of the compressed length and of the shear span ratio are shortly discussed.

Analysis of deformation and failure of sediment particle-surrounding rock structure of salt cavern gas storage under the coupled action of temperature and pressure

When gas is injected or produced in the gas storage of salt cavern, the different effects of thermal stress, gas pressure, sediment particles and brine pressure on the cavity wall of salt cavern may cause large deformation and damage in the surrounding rock, which threatens the safe and stable operation of the gas storage of salt cavern. Therefore, based on FLAC3D-PFC3D coupling method, a numerical model of salt cavern gas storage with sediment particles in consideration of temperature was constructed, and the influence of injection-production time effect, sediment particle size and initial porosity on the deformation and failure of sediment-surrounding rock structure is studied. The results show that the tensile contact force chain of sediment is sensitive to the particle size of sediment, but insensitive to the initial porosity of sediment and injection-production conditions; during gas production, the larger the particle size and initial porosity of sediment particles, the greater the vertical displacement of shallow sediment particles, and the opposite results are obtained during gas injection. With the progress of gas production and gas injection, the absolute value of vertical displacement of the roof of the salt cavern increases gradually, and the plastic failure range of surrounding rock expands; for gas production process, the larger the particle size and initial porosity of sediment, the smaller the algebraic value of vertical displacement of surrounding rock at the top of cavity and the smaller the plastic failure range of surrounding rock. For the gas injection process, the larger the particle size and initial porosity of the sediment, the larger the algebraic value of the vertical displacement of the surrounding rock at the top of the cavity and the larger the plastic failure range of the surrounding rock. The results can provide reference for the reasonable setting of injection-production operation parameters of salt cavern gas storage and ensure the safe and stable operation of underground salt cavern gas storage (USCGS).

Growing Kratky Basil in Trombe Wall Cavity: Energy Performance

This year-long experimental study, conducted in Kitakyushu, Japan, evaluates the performance of a retrofitted Trombe wall designed to cultivate hydroponically grown basil plants, aiming to enhance its year-round usability. The results show that the addition of plants reduced overheating and moderated temperature fluctuations, but also led to a 30.2% decrease in absorption and a 49.4% decrease in dissipation efficiency compared to a traditional Trombe wall. Seasonal variations influenced the suitability of the space for cultivation, with optimal conditions occurring in spring and summer, while autumn and winter posed challenges due to extreme temperature fluctuations. The daily energy balance was largely unaffected by factors such as leaf transpiration, spontaneous evaporation, additional ventilation, or increased appliance use, as these were overshadowed by the primary thermal processes: solar gains and conductive losses. Although the modified TW still provided passive heating, its energy output was reduced to approximately 10,000 MJ annually, compared to the baseline 14,000 MJ. The study suggests that alternative designs, including increased thermal mass, improved ventilation and better plant selection and could improve both cultivation and energy efficiency. Ultimately, while the green TW is best suited for seasonal use, it offers ecological and social benefits, such as local food production and CO2 fixation, highlighting its potential for integration into sustainable architectural practices.

Influence of cavity and ramp layout on combustion performance in a strut-based scramjet combustor

The computational analysis focuses on the flow performance of a wall-mounted cavity and ramp within DLR scramjet model operating in a reacting flow environment. The analysis encompasses a base setup aligned with DLR experiments, along with suggested configurations featuring different lower wall cavity depth and a fixed upper wall ramp. The 2-D Reynolds-Averaged Navier-Stokes approach (RANS) combined with Shear Stress Transport (SST) k-ω turbulence model, which incorporates single-step reaction chemistry, is utilized in steady-flow simulations. Subsequently, the unsteady-flow computations are completed using the Delayed Detached Eddy Simulation (DDES) with the SST k-ω turbulence model as a continuation of RANS analysis to compute and observe the coherent structures by using data driven methods. To examine shock structures and their associations with shear layer mixing characteristics, the cavity and ramp are positioned downstream of the strut. Inclusion of the cavity and ramp increase the number of shock waves in the flow substantially. Accordingly, complete combustion occur earlier than in the baseline model which is accompanied by a subtle increase in total pressure loss. Due to intense interactions between shock waves and shear layers, combustion zone widens laterally as the cavity displaces the shock train downstream of the strut injector. DDES results are processed to observe the dynamics and the coherent structures employing Dynamic Mode Decomposition (DMD) and Spectral Proper Orthogonal Decomposition (SPOD) methods. Both analysis show that the recirculation zone proceeds into the core engine with the progressive deepening of the cavity leading to a consequential stationary combustion.

Synchronization of E. coli Bacteria Moving in Coupled Microwells.

Synchronization plays a crucial role in the dynamics of living organisms. Uncovering the mechanism behind it requires an understanding of individual biological oscillators and the coupling forces between them. Here, a single-cell assay is developed that studies rhythmic behavior in the motility of E.coli cells that can be mutually synchronized. Circular microcavities are used to isolate E.coli cells that swim along the cavity wall, resulting in self-sustained oscillations. Connecting these cavities by microchannels yields synchronization patterns with phase slips. It is demonstrated that the coordinated movement observed in coupled E.coli oscillators follows mathematical rules of synchronization which is used to quantify the coupling strength. These findings advance the understanding of motility in confinement, and open up new opportunities for engineering networks of coupled oscillators in microbial activematter.

Growing Kratky Basil in Trombe Wall Cavity: Year-Round Overview of Thermal Effects

This experimental study explores the possibility of using an existing Trombe wall as a space for year-round cultivation to increase building resource efficiency. To do so with the least cost to the building, a small 0.75 m2/5.45 m3 Trombe wall cavity space was retrofitted with shelves placed behind the glazing, additional ventilation, and a watering network to be able to grow 400 hydroponic Kratky basil plants in individual glass jars. Historical thermal observations made at the site over a year-long timespan were contrasted with the experimental readings. When fully equipped, the Trombe wall’s thermal mass increased by 51%, which had a balancing effect on the system, lowering the average daily thermal oscillations from 35.41 °C to 17.88 °C. The living plants and water have also had significant cooling (26.99 °C to 22.91 °C) and humidifying (39.88 to 47.74%) effects. The system’s energy efficiency, however, decreased from 26 to 18% (absorption) and from 85 to 46 (dissipation), lowering its energy contribution to the building by about 30%. The average plant’s lifespan within the Trombe wall was 46 days, with 15% of the specimens surpassing the 100-day mark. Over the course of a year, 20.55 kg of edible greens were grown in the Trombe wall. The experiment has shown that it is possible to grow the plants inside the Trombe wall cavity during the warmer half of the year, revealing many possible ways to improve the space’s comfort, yields, and energy efficiency.

The confined stresslet for suspensions in a spherical cavity. Part 1. Traceless elements

The confined Stokesian dynamics (CSD) algorithm recently reported equilibrium properties but was missing hydrodynamic functions required for suspension stress and non-equilibrium properties. In this first of a two-part series, we expand the CSD algorithm to model the traceless part of the stress tensor. To obtain quantities needed to solve the integral expressions for the stress, we developed a general method to solve Stokes’ equations in bispherical coordinates. We calculate the traceless stress tensor for arbitrary particle-to-enclosure size ratio. We next compute rheology of a confined suspension by implementing the stresslet hydrodynamic coefficients into CSD, yielding the deviatoric part of the many-body hydrodynamic stresslet. We employed energy methods to relate this stresslet to the high-frequency viscosity of the confined suspension, finding an increase in viscous dissipation with crowding and confinement well beyond the unconfined value. We show that confinement effects on viscosity are dominated by near-field interactions between the particles that reside very near the cavity wall (rather than particle–wall interactions). Surprisingly, this near-field effect is stronger than the viscosity of an unconfined suspension, showing that entropic exclusion driven by the wall sets up many lubrication interactions that then generate strong viscous dissipation. The limiting case of a particle near a flat wall reveals a correction to prior literature. The theory presented in this work can be expanded to study the Brownian contribution to the viscosity of confined suspensions in and away from equilibrium. In part 2, we report the osmotic pressure, via the trace of the stress tensor.

Experimental investigation on the performance of roof tie-down straps in unreinforced masonry walls

Windstorms might lead to severe damage to houses when roof tie-down connections fail. One practice for securing a roof structure to unreinforced masonry walls is the use of tie-down straps, which consist of a thin, steel strap embedded into a brick-mortar interface at the internal leaf of unreinforced cavity walls. To date, very limited studies have been conducted on the performance of tie-down straps in unreinforced masonry walls. In this study, a total of 24 specimens were prepared to investigate the failure mechanisms and uplift capacities of tie-down straps. The effects of mortar grade, embedment depth and length, as well as the testing setup, were taken into consideration. It was found that increasing mortar grade and embedment length could increase the uplift capacities of straps by 41% and 22%, respectively, whilst increasing embedment depth has a limited effect on the uplift capacity of straps. Two new types of strap profiles were proposed: lipped and corrugated straps, which could lead to 81% and 59% higher uplift capacities, respectively, as compared to flat straps, indicating the strap profile has a significant effect on its uplift capacity.

NIMG-73. FALSE POSITIVE INTRA-OPERATIVE MAGNETIC RESONANCE IMAGING DURING HIGH GRADE GLIOMA RESECTION

Abstract Intraoperative magnetic resonance imaging (iMRI) allows assessment of extent of resection during surgery for high-grade glioma (HGG). In most cases, contrast-enhancing areas noted on iMRI indicate residual tumor. However, false positives may occur, leading to inappropriate additional resection and patient morbidity. The rate and pattern of false positive findings in iMRI have not been fully described. We analyzed surgical and imaging findings in patients undergoing iMRI during resection of HGG to determine factors linked with potential false positive contrast enhancement. A single-center analysis retrospectively assessed consecutive patients undergoing resection of newly diagnosed high-grade glioma using iMRI guidance. Preoperative, intraoperative and postoperative imaging, as well as pathologic findings were assessed. One hundred seventy-four consecutive patients who underwent surgery from 2016-2023 were included. All patients had preoperative MRI showing contrast-enhancing tumor and all underwent one iMRI during surgery to assess extent of resection. 124/174 cases (71.3%) demonstrated contrast enhancement on iMRI that prompted inspection and additional resection using updated neuronavigation. Enhancement corresponding to residual tumor was identified with or without additional removal in 120/124 cases (96.8%). No residual tumor was found in 4/124 cases (3.2%, false positives). All false positive cases were the result of contrast accumulation in hematomas (2), hemostatic agents (1) or dependent portions of the resection cavity (1). Both hematomas were located in the walls of the resection cavity and confirmed as hematoma, rather than tumor, by separate pathology analysis. False positives were not associated with patient positioning, tumor sub-type, anatomic location of tumor or extent of resection. Gross total resection (GTR) was confirmed in 163/174 (93.7%) cases on postoperative imaging. False-positive iMRI during HGG surgery can mimic residual tumor. This occurs at a low rate due to contrast pooling in the cavity or accumulation within hemostatic agents or hematomas along the cavity wall. Meticulous hemostasis when preparing the patient for iMRI may help prevent false positives and prevent unnecessary additional resection.

Exploring Early Complications in Paraumbilical Hernia Mesh Repair: A Rigorous Six-Month Prospective Study and In-Depth Analysis.

Introduction When an organ, such as the colon, pushes through the wall of the abdominal cavity, a hernia results. After femoral and inguinal hernias, umbilical hernias account for the third most common kind of abdominal hernia in adults precipitated by conditions such as obesity, ascites, and repeated pregnancies. A subtype of umbilical hernias called paraumbilical hernias is more likely to cause problems such as rupture, skin ulceration, and obstruction. Seroma, hematoma, and infection are the reported post-repair consequences but data regarding early complications is limited. High-quality data assessing early complications is necessary to improve mesh repair outcomes. Materials and methods This cross-sectional study was carried out in the Department of General Surgery at Medical Teaching Institute (MTI) Lady Reading Hospital, Peshawar over one year, from January to December 2022. A total of 167 patients were selected using simple random sequential selection. Patients aged 20-60 years of both genders who were diagnosed with paraumbilical hernia in the emergency department were included. To prevent bias, those with uncontrolled diabetes or existing complications from hernia were excluded. Following informed consent, data were gathered using pre-designed proformas. Patients underwent open mesh repair during each surgery, and they were monitored at one and three months following the procedure. Complications such as seroma, hematoma, and wound infection were documented. Data were analyzed using SPSS version 20 (IBM Corp., Armonk, NY) with chi-square tests for categorical variables and a significance level of p < 0.05. Results The study included a total of 167 patients, with a mean age of 42 years (SD ±8.77). The majority of patients (40%) ranged in age from 41 to 50 years old, with 33% aged 31 to 40. Gender distribution revealed that 63 (38%) of the patients were male and 104 (62%) were female. Early complications included 25 (15%) wound infections, 32 (19%) seromas, and 63 (38%) hematomas. The occurrence of wound infections, seromas, and hematomas did not differ significantly by age or gender (p > 0.05). Conclusion Early complications from paraumbilical hernia mesh repair include wound infections (15%), seromas (19%), and hematomas (38%). Postoperative monitoring is critical to reducing these complications.

Application of nasal pedicle mucosal flap based on nasal blood supply in reconstruction of nasal skull base defects

Objective: To evaluate the clinical efficacy of nasal pedicle tissue flap based on nasal blood supply in the reconstruction of nasal skull base defects. Methods: A retrospective analysis was conducted on 138 clinical cases of skull base tumors and cerebrospinal fluid rhinorrhea treated at the Department of Otolaryngology, Head and Neck Surgery at Xiangya Hospital of Central South University from March 2017 to March 2023. A total of 79 males and 59 females were enrolled, aged from 8 to 82 years, with a median age of 51 years, including 108 patients (78.3%) with skull base tumors and 30 patients (21.7%) with cerebrospinal fluid rhinorrhea (and/or meningoencephalocele). During the surgery, 88 cases (63.8%) were repaired with nasal septal mucosal flaps pedicled with the posterior nasal septal artery, 14 cases (10.1%) with mucosal flaps pedicled with the anterior ethmoidal artery on the lateral wall of the nasal cavity, 6 cases (4.3%) with mucosal flaps pedicled with the posterior lateral nasal artery on the lateral wall and nasal floor, 12 cases (8.7%) with mucosal flaps pedicled with the anterior ethmoidal artery and posterior ethmoidal artery, and 18 cases (13.0%) with nasal septal mucosal extension flaps pedicled with the sphenopalatine artery or internal maxillary artery. Patients were followed up for 12 to 72 months postoperatively. Endoscopic examination or skull base enhanced MRI was performed to assess the growth and tumor recurrence in the skull base repair area. The t-test was used for statistical analysis. Results: Among 138 patients, primary repair was successful in 133 patients (96.4%), while 5 patients (3.6%) experienced postoperative cerebrospinal fluid rhinorrhea. These 5 patients all underwent nasal septal mucosal flap repair with the posterior nasal septal artery as the pedicle. Complications included 1 case of mucosal flap necrosis, 1 case of mucosal flap central perforation, and 3 cases of mucosal flap survival peripheral leakage, of which were all successfully treated with a second repair. Conclusion: The use of nasal pedicle mucosal flap based on nasal blood supply is a reliable, safe, and effective technique for repairing skull base defects.

Anatomical investigation of the venous system in pedicled nasal septal mucosal flap and its application in nasal skull base reconstruction

Objective: To investigate the distribution and primary drainage sites of the venous drainage system in the pedicled nasal septal mucosal flap, as well as to examine protective measures for the venous system of the nasal septal mucosal flap and its application in repairing the nasal skull base through the anatomical study of the nasal septum mucosal venous system in cadavers. Methods: Gross anatomy dissections were performed on 13 sides perfused fresh frozen cadaveric head specimens. The nasal septum mucosal flap was separated along the perichondrium and subperiosteum, then passed across the vomer, anterior wall of sphenoid sinus, clivus, and towards the anterior edge of vertical plate of palatine bone. Detailed documentation, including photographs, was made to record the morphology, distribution and drainage location of veins of the nasal septum mucosal flap and its pedicle, along with number of sphenopalatine veins. Furthermore, venous injuries resulting from obtaining a pedicled nasal septal mucosa flap were observed. From March 2023 to March 2024, a retrospective analysis was conducted on patients with nasopharyngeal lesions who underwent surgical repair using a modified pedicled nasal septum mucosal flap for venous system protection in the ENT institute and Department of Otorhinolaryngology at the Eye & ENT Hospital of Fudan University. The postoperative endoscopy was employed to assess the viability of the mucosal flap. Results: The veins of the nasal septum mucosa were primarily located in the posterior region, including the vomerine region, anterior wall of the sphenoid sinus, clivus region, and posterolateral wall of the nasal cavity, in a reticular pattern. Perforating veins draining into these bony structures could be observed, although their quantity and morphology varied. Notably, no prominent sphenopalatine veins were identified in 10 specimens examined, while 3 specimens exhibited sphenopalatine veins: one with a small single branch and two with venous bundles. Preservation of the nasal septal vein was possible when dissection was limited to the anterior edge of the wing of vomer. A wider range of dissection increased the risk of veinous injury. In cases where only vascular pedicles at the sphenopalatine foramen were preserved, three cadaveric head specimens retained intact sphenopalatine veins, while drainage veins were completely destroyed in ten other specimens. Fifteen patients with unilateral lesions (8 with recurrent nasopharyngeal carcinoma and 7 with nasopharyngeal radionecrosis) were included in this study. The postoperative reconstructions were carried out using contralateral pedicled nasal septal mucosal flaps. The average follow-up time was 7 months (ranging from 3 to 12 months), and all the nasal septal mucosal flaps survived. Conclusions: The primary location of the drainage vein within the nasal septum mucosa is situated in its posterior region, where it penetrates into adjacent bone structures. Very few sphenopalatine veins pass through the sphenopalatine foramen. Extensive dissection of the pedicled nasal septal mucosal flap may potentially impair the venous system and adversely affect flap survival rates, necessitating further clinical exploration.

The Role of Heater Size and Location in Modulating Natural Convection Behavior in Cu-Water Nanofluid-Loaded Square Enclosures

Enhancing the energy efficiency of thermal systems reduces their consumption, lowers costs, and reduces undesired environmental impact, thus making these systems more sustainable. The current work introduces a passive method for heat transfer enhancement that is carried out using natural convection by nanofluid. This work introduces a computational study of the process of natural convection within a square cavity containing Cu/H2O nanofluid. The cavity wall on the left side undergoes partial isothermal heating, while the opposing side is fully cooled isothermally, with all other boundaries maintained adiabatic. A mathematical model formulated based on a 2-D model was used to provide the solution for the system of governing equations of mass, momentum, and energy conservation, employing the finite element technique. A commercial CFD package is utilized to perform the computational simulation. The present investigation delves into the impact of the Rayleigh number, nanoparticle concentration, heater length, and heater location on the flow field and heat transfer characteristics. The model outcomes were displayed for a wide range of the pertinent parameters as 103 ≤ Ra ≤ 106, 0.25 ≤ lh ≤ 1.0, 0.125 ≤ hc ≤ 0.875, and 0.02 ≤ ϕ ≤ 0.10. Also, correlation equations relating the average Nusselt number to these crucial parameters are derived. These equations are simple and can be applied in practice easily in many fields, such as electric and electronic equipment cooling and thermal management of heat sources. Also, these equations gather all the parameters that affect the heat transfer process. They are shedding light on the intricate interplay between these parameters in the natural convection heat transfer process.

Engineering Higher-Order Topological Confinement via Acoustic Non-Hermitian Textures.

Higher-order topological insulators are a newly unveiled category of topological materials, distinguished by their exceptional characteristics absent in conventional topological insulators, e.g., 1D hinge states, or zero-dimensional corner states, for instance. Adding attenuating or amplifying components manifest even richer and more intricate non-Hermitian topological properties. While losses, for the most part, come for free, decorating topological systems with the gain counterpart poses significant challenges. Here, a non-Hermitian second-order topological insulator (SOTI) is constructed for a sonic demonstration, by bestowing a cavity-based lattice both with electro-thermoacoustic gain and loss. The inner cavity walls are decorated with electrically biased carbon nanotube films to be able to manipulate spatially and in strength, a non-Hermitian response at will. These measurements demonstrate that this flexibility allows us to design highly unconventional interface and corner confining topologies by decisively engineering gain and loss textures within the unit cell. It is foreseen that the advances may enable new avenues for energy harvesting and fundamental understanding in condensed matter and classical topologicalphysics.

Characteristics of Pulmonary Inflammation in Patients with Different Forms of Active Tuberculosis.

Targeted treatment of tuberculosis-associated lung damage requires an understanding of the precise mechanisms of immunopathology. A major obstacle to the longitudinal study of tuberculosis (TB) immunopathogenesis in humans is the lack of serial lung biopsies during disease progression and treatment, which could be used to characterize local immune pathways involved in tissue damage. Understanding of the immunobiology of lung tissue damage in tuberculosis has largely been based on animal models. Our study looked for signs of inflammation in TB patients' lung biopsies. Results were compared between a site of infection and relatively healthy tissue outside the site. The most significant differences in the expression of microRNAs (miRs) and cytokine/chemokines were observed between the non-decayed tuberculoma and the surrounding parenchyma. In addition, these parameters showed almost no differences between the cavitary wall and surrounding tissue. This is an indication that the inflammatory process is more prevalent in fibrotic cavitary tuberculosis (FCT). In FCT subjects, no difference was observed between the cavity wall and the parenchyma in the production of key inflammatory factors such as IL-6, IL-11, IL-17, and IFNγ. This is an indication that the limits of the inflammatory response are broader in FCT. The expression levels of miR-191, miR-193a, miR-222, miR-223, miR-18, miR-155, miR-376c, miR-26a, miR-150, and miR-124 were not significantly different between the cavernous wall and lung tissue in patients with FCT, further confirming the spread of inflammatory and destructive processes beyond the focus of infection.

3D printable earth-based alkali activated “ink”: Effect of alkali concentration and binder-to-aggregate ratio

This research attempts to investigate the effect of activator concentration (4 mol/L (M) and 8M) and binder-to-aggregate (B:A) ratio (ranging from 1:1 to 1:3 by weight) on extrudability and buildability of 3D printable natural earth-based alkali-activated materials (EAAM). It is found that natural clay in soil, used to replace 25 % of M-sand, imparts higher thixotropy, evident from 90 to 100 % recovery in viscosity compared to 65–80 % for corresponding control (containing only M-sand and no soil). Presence of clay increases the dynamic yield stress than control but reduces the plastic viscosity by 80 – 90 % in EAAM compared to corresponding control where interlocking between sand particles resists smooth extrusion of the material. EAAMs made with 8M NaOH have higher flow retention and maintain 95–100 % recovery in viscosity for longer duration than 4M EAAM. This contributes to superior extrusion quality of 8M EAAM than 4M EAAM. The findings suggest that binder content can be reduced as concentration of NaOH is increased from 4M to 8M. This is evident from lower layer deformation (0.09 % of original height) under self-weight and higher 3D printed buildable height of at least 457 mm in 8M EAAM with B:A of 1:2 compared to a maximum of 375 mm for 4M EAAM at higher B:A of 1:1. Ratios of wet compressive strength to dry compressive strength vary between 0.92 and 1.09 in 8M EAAM compared to 0.79 – 0.85 for 4M EAAM at 28-day age, suggesting lower sensitivity to moisture due to improved clay stabilization. Based on the strength and moisture sensitivity, the developed material can serve as a low-carbon and durable alternative to Portland cement in the construction of masonry elements in buildings, including cavity walls, panels, flooring tiles and façade members.

Physics-informed neural network solution for thermo-elastic cavity expansion problem

ABSTRACT This paper proposes a physics-informed neural network (PINN) to solve the thermo-elastic coupled cavity expansion problem under plane strain conditions. The solid is modelled as a linear thermo-elastic material, and cavity expansion is driven by a constant temperature and a radial displacement subjected to the inner cavity wall. Governing partial differential equations (PDEs) for the problem is firstly presented, and an analytical solution is available to help benchmark the PINN approach. Then, the PDEs are normalised into dimensionless forms and neural network details for solving the coupled PDEs are demonstrated. Finally, the performance of the PINN approach is shown by comparison with the analytical benchmark solution and it is found that the PINN can predict thermo-elastic cavity expansion behaviour with high accuracy. The PINN approach and the analytical solution can also serve as a benchmark for solving thermo-elastic coupled problems in geotechnical engineering by more advanced PINN.