Magnetic field and initial stress on a rotating photothermal semiconductor medium with ramp type heating and internal heat source.

This manuscript addresses a significant research gap in the study by employing a mathematical model of photo thermoelastic wave propagation in a rotator semiconductor medium under the effect of a magnetic field and initial stress, as well as ramp-type heating. The considered model is formulated during the photothermal theory and in two-dimensional (2D) electronic-elastic deformation. The governing equations represent the interaction between the primary physical parameters throughout the process of photothermal transfer. Computational simulations are performed to determine the temperature, carrier density, displacement components, normal stress, and shear stress using the application of Lame's potential and normal mode analysis. Numerical calculations are carried out and graphically displayed for an isotropic semiconductor like silicon (Si) material. Furthermore, comparisons are made with the previous results obtained by the others, as well as in the presence and absence of magnetic field, rotation, and initial stress. The obtained results illustrate that the rotation, initial stress, magnetic field, and ramp-type heating parameter all have significant effects. This investigation provides valuable insights into the synergistic dynamics among a magnetization constituent, semiconducture structures, and wave propagation, enabling advancements in nuclear reactors' construction, operation, electrical circuits, and solar cells.

Influence of inclined magnetic field and heat transfer on the peristaltic flow of Rabinowitsch fluid model in an inclined channel.

The recent study is focused on discussion of heat transfer and magnetic field results of peristaltic flow of Rabinowitsch fluid model in an Inclined Channel. In this piece of research, peristalsis's fundamental problem with heat transfer in the presence of a magnetic field is checked. An incompressible Rabinowitsch fluid is present in an inclined channel, which is considered as the reference for this research. The solutions are devised with the assumptions of long wavelength and low Reynolds number approximations. The resulting equations are then solved exactly by implementing various command of MATHEMATICA subject to relevant boundary conditions. Results are discussed for various flow quantities like temperature, velocity, tangential stress, pressure gradient and rise, and friction force. Computational simulations are performed to determine the flow quantities. This investigation goes beyond mere calculations and examines particle motion to gain deeper insights into flow quantities. Furthermore, this investigates how magnetic field and heat transfer parameters influence these peristaltic flow phenomena. The outcomes of important parameters were plotted and scrutinized. There is amultitude of medical implementations derived from the current consideration, such as the depiction of the gastric juice motion in the small intestine when an endoscope is inserted through it.

Magneto-hydrodynamic peristaltic flow of a Jeffery fluid in the presence of heat transfer through a porous medium in an asymmetric channel.

In the present paper, the effects of magnetic field and heat transfer on the peristaltic flow of a Jeffery fluid through a porous medium in an asymmetric channel have been studied. The governing non-linear partial differential equations representing the flow model are transmuted into linear ones by employing the appropriate non-dimensional parameters under the assumption of long wavelength and low Reynolds number. Exact solutions are presented for the stream function, pressure gradient, and temperature. The frictional force and pressure rise are both computed using numerical integration. Using MATLAB R2023a software, a parametric analysis is performed, and the resulting data is represented graphically. For all physical quantities considered, numerical calculations were made and represented graphically. Trapping phenomena are discussed graphically. The obtained results can be applied to enhance pumping systems in engineering and gastrointestinal functions. This analysis permits body fluids such as blood and lymph to easily move inside the arteries and veins, allowing oxygen supply, waste elimination, and other necessary elements.

Effect of heat and mass transfer on the nanofluid of peristaltic flow in a ciliated tube.

The current work focuses attention on discussing the peristaltic flow of Rabinowitsch nanofluid through ciliated tube. This technical study analyzes heat and mass transfer effects on the flow of a peristaltic flow, incompressible, nanofluid via a ciliated tube. The governing non-linear partial differential equations representing the flow model are transmuted into linear ones by employing the appropriate non-dimensional parameters under the assumption of long wavelength and low Reynolds number. The flow is examined in wave frame of reference moving with the velocity [Formula: see text]. The governing equations have been solved to determine velocity, temperature, concentration, the pressure gradient, pressure rise and the friction force. Using MATLAB R2023a software, a parametric analysis is performed, and the resulting data is represented graphically. The results indicate that the various emerging parameters of interest significantly affect the nanofluid properties within the tube. The present study enhances the comprehension of nanofluid dynamics in tube and offers valuable insights into the influence of heat and mass transfer in such setups. Convective heat transfer is found to be greater at the boundaries resulting in decreased temperature there.

Influence of an inclined magnetic field and heat and mass transfer on the peristaltic flow of blood in an asymmetric channel.

This article presents a theoretical study on heat and mass transfer analysis of the peristaltic flow of blood conveying through an asymmetric channel in the presence of inclined to the magnetic field. The effects of ratio of relaxation to retardation times, non-uniform parameter, the non-dimensional amplitude, Hartman number and phase difference have been taken into account. The governing coupled non-linear partial differential equations representing the flow model are transmuted into linear ones by assuming that the wave is very long with a small Reynolds number. The converted mathematical formulations are solved analytically via the Mathematica software. Analytical expressions for the dimensionless velocity profiles of fluid, temperature, concentration, pressure gradient, increase in pressure, heat transfer coefficient and shear stress of the blood are derived. The velocity, temperature, concentration, pressure gradient, increase in pressure, heat transfer coefficient and shear stress were calculated numerically for different values of the parameters, which were represented graphically and find their physical meaning.

Heat and mass transfer for MHD peristaltic flow in a micropolar nanofluid: mathematical model with thermophysical features.

According to a survey of the literature, nanofluids are superior to traditional fluids at transferring heat. A detailed analysis of the models mentioned above is crucial since there are large gaps in the illumination of current solutions for improving heat transfer in nanomaterials. The ongoing investigation's purpose is to ascertain the tiny size gold particles drift in free with the heat and mass transfer, buoyancy forces, thermophoresis, and Brownian motion of a micropolar nanofluid being transported through a porous medium in an asymmetric channel with a uniform magnetic field using a long-wavelength and low Reynolds number approximation. The resulting dimensionless nonlinear governing equations have been numerically solved using a MATLAB software and the Runge-Kutta-Fehlberg integration scheme. Two comparisons with previously investigated problems are also made to confirm our findings, and an excellent concurrence is discovered. As a result, trustworthy results are being given. Numerical solutions are used to describe the effects of different thermal-fluidic parameters on velocity profiles, temperature, concentration, micropolar rotation, pressure gradient, shear stress, heat flux, and nanoparticle volume flux, etc. Tables, graphs, and bar charts are used to present and discuss numerical results that have been produced. A comparison of the resulting numerical solution to earlier literature also reveals a satisfactory level of agreement. Insight into real-world applications such nanofluidic, energy conservation, friction reduction, and power generation are provided by this work. Furthermore, the Brownian and thermophoresis parameters behave significantly differently in a concentration field. On the other hand, the study puts forward an important note that for peristaltic flow of a micropolar fluid with nanoparticles can be controlled by suitably adjusting the micropolar parameter, thermophoresis parameter, nanoparticle Grashof number, and Brownian motion parameter.

Peristaltic pump with heat and mass transfer of a fractional second grade fluid through porous medium inside a tube.

In magnetic resonance imaging (MRI), this MRI is used for the diagnosis of the brain. The dynamic of these particles occurs under the action of the peristaltic waves generated on the flexible walls of the brain. Studying such fluid flow of a Fractional Second-Grade under this action is therefore useful in treating tissues of cancer. This paper deals with a theoretical investigation of the interaction of heat and mass transfer in the peristaltic flow of a magnetic field fractional second-grade fluid through a tube, under the assumption of low Reynolds number and long-wavelength. The analytical solution to a problem is obtained by using Caputo's definition. The effect of different physical parameters, the material constant, magnetic field, and fractional parameter on the temperature, concentration, axial velocity, pressure gradient, pressure rise, friction forces, and coefficient of heat and mass transfer are discussed with particular emphasis. The computed results are presented in graphical form. It is because the nature of heat and mass transfer coefficient is oscillatory which is following the physical expectation due to the oscillatory nature of the tube wall. It is perceived that with an increase in Hartmann number, the velocity decreases. A suitable comparison has been made with the prior results in the literature as a limiting case of the considered problem.

Effect of different surface treatments on the microhardness and colour change of artificial enamel lesions.

BACKGROUND: To investigate the effect of three different surface treatments on the microhardness and colour change of artificial enamel lesions. MATERIALS AND METHODS: One hundred bovine teeth were randomly assigned into four groups. Artificial enamel lesions were created using demineralizing solution for all groups except the sound enamel group. Different surface treatments were then performed G1: resin-infiltrant; G2: Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP); G3: artificial saliva; G4: Sound Enamel. Each group was subdivided into three subgroups, where each subgroup was subjected to a different testing method. Subgroup 1: surface microhardness; subgroup 2: cross-sectional microhardness; subgroup 3: colour measurement. Statistical analysis was performed by ANOVA, followed by Tukey's post hoc test. RESULTS: Sound enamel group recorded the highest surface and cross-sectional microhardness results. No significant difference was found between the resin-infiltrant group and CPP-ACP regarding surface and cross-sectional microhardness at different lesion depths. Resin-infiltrant group showed the least colour change (∆E) results compared to the other groups. CONCLUSION: Resin-infiltrant can effectively enhance surface microhardness and enamel resistance to demineralization, additionally, reduces the staining susceptibility of white spot lesions (WSLs) after treatment. CPP-ACP application for 4 weeks seems to improve surface microhardness; however, has a limited effect in resisting staining of WSLs after treatment. © 2022 Australian Dental Association.

The reproducibility of the novel utilization of five-dimensional ultrasound and power Doppler in the prediction of endometrial receptivity in intracytoplasmic sperm-injected women: a pilot prospective clinical study.

OBJECTIVE: The ultimate goal of this study is to reassess the five-dimensional implantation markers and pregnancy predictors on the day of human chorionic gonadotropin injection in the intracytoplasmic sperm injection and embryo transfer programs. DESIGN: A pilot prospective clinical trial. SETTING: The Assisted Reproductive Technology Unit of Ain Shams Maternity Teaching Hospital during the period from April 2014 to December 2017. PATIENTS AND METHODS: The study was conducted on 400 women undergoing intracytoplasmic sperm injection (ICSI). Those women were not older than 40 years, with normal uterine cavity and with no previous uterine scars. INTERVENTION: The ovarian stimulation protocol, used in this study for all patients, was the long protocol, before ovarian stimulation therapy, patients were instructed to use oral contraceptive pills from day 2 starting in the preceding cycle, then the standard regimen. On the day of hCG administration, 5D transvaginal ultrasound measurements were performed by the same observer after the patients had emptied their bladders. Measurements included endometrial volume and 3D power Doppler parameters, endometrial vascularization index, flow index, and vascularization flow index. RESULTS: The present study shows that endometrial volume ≥ 5 in the prediction of endometrial receptivity in ICSI patients had good sensitivity and low specificity in a group application; in an individual application it had good predictive negative value and bad predictive positive value. So it could be used as a good test to exclude success. Overall pregnancy rate was 40.5%; endometrial volume, flow index, vascularization index, and vascularization flow index were significantly lower in the nonpregnant group than those of the pregnant group. The area under curve in the receiver operating characteristic for three-dimensional ultrasound and power Doppler angiography parameters was statistically significant, but their values were suggestive but not conclusive in the prediction of endometrial receptivity in ICSI patients, no cutoff points with good diagnostic characteristics could be obtained. CONCLUSION: Five-dimensional ultrasound and power Doppler angiography is a useful exam to assess the endometrial receptivity in IVF/ICSI and embryo transfer cycles.

[Retrieval of a migrated plastic stent in a 51-year-old man]. / Bergung eines migrierten Doppel-Pigtail-Stents bei einem 51-jährigen Patienten.

BACKGROUND: Endosonographically guided transgastric drainage is the first-line interventional therapy of walled-off necrosis and symptomatic pancreatic pseudocysts in necrotizing pancreatitis. Plastic stents or lumen apposing metal stents are commonly used. A possible complication of endoscopic therapy is stent migration. CASE REPORT: We report upon a 51-year-old man who presented with acute necrotizing pancreatitis. Transgastric necrosectomy was performed and 5 transmural double-pigtail stents (DPS) were left in situ to drain the residual retroperitoneal cavity. The patient recovered and 4 stents were endoscopically removed 5 weeks later on an outpatient basis, whereas the fifth stent was suspected to have passed spontaneously via the natural route. The asymptomatic patient presented 3 months later for follow-up computed tomography. The necrosis had healed but one DPS was seen beyond the gastric wall near the kidney. Transmural access to the stent could be achieved by an endosonographically guided puncture toward the proximal portion of the stent followed by placement of a hydrophilic guidewire alongside the stent. A new gastrostomy was created by using a 6F cystotome followed by wire-guided dilation with a 12 mm balloon. The stent could then be grasped with transmurally inserted rat-tooth forceps and repositioned across the gastrostomy site. The patient was given prophylactic antibiotics. After removal of the stent, the patient could be discharged. CONCLUSION: Herein, we present the successful endosonographically guided transmural removal of a retroperitoneally migrated plastic stent. Of note, in our patient we had to rely completely on endosonography and radiography for localization and targeting of the stent, since the former necrotic cavity had meanwhile completely healed.

Endoscopic rendez-vous reconstruction of complete biliary obstruction.

BACKGROUND AND STUDY AIMS: Complete biliary strictures normally require surgical intervention. We describe an alternative, minimally invasive endoscopic/percutaneous rendez-vous technique for the reconstruction of complete benign biliary strictures. PATIENTS AND METHODS: Complete biliary strictures were reconstructed in four patients using a rendez-vous percutaneous-endoscopic or percutaneous-percutaneous route guided by fluoroscopic and visual (transillumination) control. RESULTS: All four patients were treated successfully and safely with the rendez-vous technique. Complications were caused by the preliminary creation, dilatation and maturation of the percutaneous tract. CONCLUSION: This technique may offer a good alternative to surgical bilio-enteric anastomosis in experienced hands. The long term course of the patients treated remains to be seen.

Vaginal progesterone decreases preterm birth and neonatal morbidity and mortality in women with a twin gestation and a short cervix: an updated meta-analysis of individual patient data.

OBJECTIVE: To assess the efficacy of vaginal progesterone for the prevention of preterm birth and neonatal morbidity and mortality in asymptomatic women with a twin gestation and a sonographic short cervix (cervical length ≤ 25 mm) in the mid-trimester. METHODS: This was an updated systematic review and meta-analysis of individual patient data (IPD) from randomized controlled trials comparing vaginal progesterone with placebo/no treatment in women with a twin gestation and a mid-trimester sonographic cervical length ≤ 25 mm. MEDLINE, EMBASE, POPLINE, CINAHL and LILACS (all from inception to 31 December 2016), the Cochrane Central Register of Controlled Trials, Research Registers of ongoing trials, Google Scholar, conference proceedings and reference lists of identified studies were searched. The primary outcome measure was preterm birth < 33 weeks' gestation. Two reviewers independently selected studies, assessed the risk of bias and extracted the data. Pooled relative risks (RRs) with 95% confidence intervals (CI) were calculated. RESULTS: IPD were available for 303 women (159 assigned to vaginal progesterone and 144 assigned to placebo/no treatment) and their 606 fetuses/infants from six randomized controlled trials. One study, which included women with a cervical length between 20 and 25 mm, provided 74% of the total sample size of the IPD meta-analysis. Vaginal progesterone, compared with placebo/no treatment, was associated with a statistically significant reduction in the risk of preterm birth < 33 weeks' gestation (31.4% vs 43.1%; RR, 0.69 (95% CI, 0.51-0.93); moderate-quality evidence). Moreover, vaginal progesterone administration was associated with a significant decrease in the risk of preterm birth < 35, < 34, < 32 and < 30 weeks' gestation (RRs ranging from 0.47 to 0.83), neonatal death (RR, 0.53 (95% CI, 0.35-0.81)), respiratory distress syndrome (RR, 0.70 (95% CI, 0.56-0.89)), composite neonatal morbidity and mortality (RR, 0.61 (95% CI, 0.34-0.98)), use of mechanical ventilation (RR, 0.54 (95% CI, 0.36-0.81)) and birth weight < 1500 g (RR, 0.53 (95% CI, 0.35-0.80)) (all moderate-quality evidence). There were no significant differences in neurodevelopmental outcomes at 4-5 years of age between the vaginal progesterone and placebo groups. CONCLUSION: Administration of vaginal progesterone to asymptomatic women with a twin gestation and a sonographic short cervix in the mid-trimester reduces the risk of preterm birth occurring at < 30 to < 35 gestational weeks, neonatal mortality and some measures of neonatal morbidity, without any demonstrable deleterious effects on childhood neurodevelopment. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.