Voiding Parameters Research Articles

Effect of Thomson and thermal loading due to laser pulse in a magneto‐thermo‐elastic porous medium with energy dissipation

AbstractThe present work attempts to investigate the influence of the Thomson heating and the Fourier's heat conduction, in the presence of a magnetic field, on half‐space thermo‐electricity solid with voids. The material is heated by a non‐Gaussian laser beam with pulse duration of 0.23 ps. The heat conduction equation is affected by the Thomson coefficient. A constant Thomson coefficient, instead of traditionally a constant Seebeck coefficient, was assumed. The charge density of the induced electric current is taken as a function of time. The basic governing equations are modified by using Green–Naghdi theory of type‐III. A normal mode method is proposed to analyze the problem and obtain numerical solutions. The results of the physical quantities have been illustrated graphically by a comparison between two values of time, with and without void parameters, as well as with and without Thomson coefficient.

N-acetylcysteine prevents bladder tissue fibrosis in a lipopolysaccharide-induced cystitis rat model

Therapeutic options for non-Hunner type interstitial cystitis (IC), which is histologically characterized by fibrosis and mast cell infiltration, are limited. We developed a rat model that replicates chronic inflammation and fibrosis and evaluated the therapeutic effect of N-acetylcysteine (NAC), a well-known anti-fibrotic agent, on the model. Intravesical instillation of lipopolysaccharide (LPS, 750 μg) after protamine sulfate (10 mg) was conducted twice per week for five consecutive weeks. One week after final instillation, 200 mg/kg NAC (n = 10, IC + NAC group) or phosphate-buffered saline (n = 10, IC group) was daily injected intraperitoneally once daily for 5 days. LPS instillation induced bladder fibrosis, mast cell infiltration, and apoptotic tissue damage. Functionally, LPS insult led to irregular micturition, decreased inter-contraction intervals, and decreased micturition volume. NAC significantly improved most of the voiding parameters and reversed histological damages including fibrosis. NAC inhibited the induction and nuclear localization of phospho-Smad2 protein in bladder tissues and the upregulation of genes related to fibrosis, such as Tgfb2, Tgfb3, Smad2, Smad3, Cxcl10, and Card10. This is the first study to demonstrate the beneficial effects on NAC in restoring voiding function, relieving tissue fibrosis and related bladder injuries, in the LPS-induced cystitis rat model.

Laboratorial investigation on effects of microscopic void characteristics on properties of porous asphalt mixture

Abstract The properties of porous asphalt mixture significantly depend on its microscopic void characteristics. This paper mainly studied the correlation between the properties of porous asphalt mixture and three types of void characteristic parameters obtained through computed tomography (CT). It was found that the microscopic void characteristic parameters presented little influence on the moisture sensitivity resistance at high temperature and cooling performance, but strong correlation with other properties such as raveling resistance, permeability, connective porosity and noise reduction. In particular, the equivalent diameter and area exhibited strong correlation with properties of asphalt mixture. Moreover, the maximum equivalent diameter of void exerted the most significant impact on the properties of asphalt mixture. The investigated results could provide useful insights for optimizing and enhancing properties of porous asphalt mixture using the microscopic void parameters.

Waves in dual-phase-lag thermoelastic materials with voids based on Eringen’s nonlocal elasticity

The main idea of the present work is to extend Eringen’s theory of nonlocal elasticity to generalized thermoelasticity with dual-phase-lag and voids. Then we study the propagation of time harmonic plane waves in an infinite nonlocal dual-phase-lag thermoelastic medium with voids. Three sets of coupled dilatational waves and an independent transverse wave may travel with distinct speeds through the medium. All these waves are found to be dispersive in nature. The coupled dilatational waves are damping, while the transverse wave is undamped in a certain range of the angular frequency. Coupled dilatational waves are found to be influenced by the presence of voids, thermal field and elastic nonlocal parameter, while the transverse wave is found to be influenced by the nonlocal parameter, but independent of void and thermal parameters. For a particular model, the effects of angular frequency, elastic nonlocality parameter, and some voids and thermal parameters on the wave speeds and damping coefficients of all the propagating waves have been studied numerically. Some comparisons are made between the results obtained for local and nonlocal cases. All the computed results have been depicted graphically and explained in details.

Study on frost resistance durability and bubble parameters of high air content concrete under different freezing rate

The frost resistance durability and bubble parameters of high air content concrete under different freezing rate were studied from the perspective of macroscopic and microscopic properties. The frost resistance durability and air void parameters of concrete were analysed at multiple scales by electronic balance, non-metal ultrasonic tester and linear traverse method, respectively. The results indicated that the mass and dynamic elastic modulus of concrete decrease with the increase of freezing rate. As the freezing rate increases, the bubble spacing of concrete increases, and the average diameter of the bubbles becomes larger. Therefore, in addition to the low temperature during freezing, freezing rate is another important factor affecting the durability of concrete.

Using a checklist to increase the effectiveness of behavioral therapy for overactive bladder: A prospective randomized controlled trial.

To evaluate the benefits of a newly established checklist form of behavioral therapy for overactive bladder (OAB). Of a total of 180 patients suffering eight or more micturitions, two or more nocturia, seven or more urgency, or four more urinary urgency incontinence (UUI) episodes per day according to a 3-day bladder diary, 155 were randomly divided into four groups. Group I (n = 29) patients were instructed to apply only behavioral therapy as a written guideline and group II (n = 27) patients were instructed to apply behavioral therapy with a written checklist. Group III (n = 26) patients received medical treatment plus behavioral therapy without a checklist. Group IV (n = 28) patients received medical treatment with a written checklist over a 6-month period. A total of 110 participants completed the study period. The demographic data and baseline voiding parameters such as frequency, urgency, nocturia, and UUI of the participants in all four groups were similar (P > 0.05 for all). At the end of the study period, the highest rates of treatment response (64.3%) and adherence (85.7%) were determined for the patients with antimuscarinic drugs plus checklist. The persistence rate of patients using antimuscarinics with the checklist was higher than that of those using antimuscarinics plus a written guideline of behavioral therapy (75.4% vs 60.2%). The effectiveness of behavioral therapy for OAB can be improved with this newly designed checklist. In addition, the adherence and persistence rate of medical treatment may also improve with the checklist used.

Study on the Die-Attach Voids Distribution With X-Ray and Image Processing Techniques

Power electronic components' reliability depends, to a great extent, on the quality of die-attach technology. The voids appearance in the die-attach regions is almost unavoidable during the manufacturing process. The aim of this paper is to demonstrate that image processing tools enable fast and accurate void segmentation, while reducing manual interaction for X-ray monitoring of imperfect power transistor die soldering. The most common void parameters such as void area, void distribution, and shape roundness were extracted and used for statistical analysis.

Freezing-thawing resistance evaluations of concrete pavements with deicing salts based on various surfaces and air void parameters

The interaction of deicing chemicals and freezing-thawing cycles produces serious scaling damage of airport concrete pavement. The indoor test of freezing-thawing resistance with deicing salts of concrete is still open to the question, and the indirect evaluation method has inherent disadvantages. In this study, the damage process of different surfaces of concrete when immersed into deicing salt solution was compared and analyzed. Roughness growth ratio (RGR) was proposed to quantify the degree of pockmark caused by salt freeze damage. Industrial computer tomography (CT) technology was used to scan the hardened cement concrete specimens to obtain the bubble structure distribution information. The void-to-void distance as a factor was proposed to evaluate the freezing-thawing resistance with deicing salts performance of the cement concrete, and compared with the Power’s spacing factor of the salt resistance performance of the hardened cement concrete in the existing specification. The results revealed that the molded surface showed the worst resistance to the salt frost action, followed by the molded side, and the sawed side was the best. It was found that there was a good correspondence between the air content of concrete test surface and the mass loss during freezing-thawing cycles. Powers’ spacing factor was found to underestimate the resistance potential to frost damage when compared to the void-to-void distance factor d-, which had a good correlation with scaling mass at 28 freezing-thawing cycles. Thus, the freezing-thawing resistance with deicing salts of the cement concrete could lead to introduce the void-to-void distance factor d- for characterization of hardened concrete.

Love waves in a nonlocal elastic media with voids

The propagation of Love-type waves in a nonlocal elastic layer with voids resting over a nonlocal elastic solid half-space with voids has been studied. Dispersion relations are derived using appropriate boundary conditions of the model. It is found that there exist two fronts of Love-type surface waves that may travel with distinct speeds. The appearance of the second front is purely due to the presence of voids in layered media. Both fronts are found to be dispersive in nature and affected by the presence of the nonlocality parameter. The first front is found to be nonattenuating, independent of void parameters and analogous to the Love wave of classical elasticity, while the second front is attenuating and depends on the presence of void parameters. Each of the fronts is found to face a critical frequency above which it ceases to propagate. For a specific model, the variation of the phase speeds of both the fronts with frequency, nonlocality, voids and thickness parameters is shown graphically. Attenuation coefficient versus frequency for the second front has also been depicted separately. Some particular cases are deduced from the present formulation.

Plane waves in nonlocal thermoelastic solid with voids

This work is concerned with the propagation of time harmonic plane waves in an infinite nonlocal thermoelastic solid having void pores. Three sets of coupled dilatational waves and an independent transverse wave may travel with distinct speeds in the medium. All these waves are found to be dispersive in nature, but the coupled dilatational waves are attenuating, while transverse wave is nonattenuating. Coupled dilatational waves are found to be influenced by the presence of voids, thermal field and elastic nonlocal parameter. While the transverse wave is found to be influenced by the nonlocal parameter, but independent of void and thermal parameters. For a particular model, the effects of frequency, void parameters, thermal parameter and nonlocality have been studied numerically on the phase speeds, attenuation coefficients and specific losses of all the propagating waves. All the computed results obtained have been depicted graphically and explained.

Global topology of contact force networks: Insight into shear thickening suspensions.

Highly concentrated particle suspensions (also called slurries) can undergo a sharp increase in viscosity, or shear thickening, under applied stress. Understanding the fundamental features leading to such rheological change is crucial to optimize flow conditions or to design flow modifiers for slurry processing. While local changes to the particle environment under applied shear can be related to changes in viscosity, there is a broader need to connect the shear thickening transition to the fundamental organization of particle-interaction forces which lead to long-range organization. In particular, at a high volume fraction of particles, recent evidence indicates frictional forces between contacting particles is of importance. Herein, the network of frictional contact forces is analyzed within simulated two-dimensional shear thickening suspensions. Two topological metrics are studied to characterize the response of the contact force network (CFN) under varying applied shear stress. The metrics, geodesic index and the void parameter, reflect complementary aspects of the CFN: One is the connectedness of the contact network and the second is the distribution of spatial areas devoid of particle-particle contacts. Considered in relation to the variation of the viscosity, the topological metrics show that the network grows homogeneously at large scales but with many local regions devoid of contacts, indicating clearly the role of CFN growth in causing the large change in the rheological response at the shear thickening transition.

The efficacy of green light laser prostatectomy in the management of urinary retention due to prostate hyperplasia.

To evaluate the efficacy and safety of 120W potassium titanyl phosphate (KTP) in the treatment of urinary retention (UR) due to benign prostate hyperplasia in high-risk patients. Forty-six male patients with mean age of 73.78 ± 9.82years who اhad UR and underwent 120W KTP laser vaporization of the prostate between January 2015 and June 2017 were included. We evaluated perioperative parameters including serum prostate specific antigen, prostate volume, period of postoperative catheterization, vaporization time, delivered energy, hospitalization period, as well as intraoperative and postoperative complications. In the follow-up protocols, International Prostate Symptom Score and quality-of-life questionnaire (IPPS-QoL) and postvoid residual volume (PVR) were also assessed. The mean follow-up period was 15.57 ± 9.26 (1-42) months. All patients get rid of UR, except 1 patient (2.1%) remained on Foley catheter and standard TURP was done. Mean vaporization time was 8.57 ± 4.19min, and mean energy delivered was 51.7 ± 29.9kJ. No intraoperative complications were observed and no blood transfusion was done. The mean postoperative IPSS at the last follow-up was 9.64 ± 6.65 and the QoL score was 1.61 ± 1.31. Green light laser prostatectomy is a safe, simple, and effective procedure for the treatment of UR secondary to BPH in high-risk patients. Short hospitalization, low rate of intra operative and postoperative complications with rapid improvements in the objective, and subjective voiding parameters are important considerations of this procedure.

Aquablation of the prostate: single-center results of a non-selected, consecutive patient cohort.

Aquablation of the prostate using the AquaBeam™ system promises equivalent functional outcomes, reduced learning curve, and improved sexual function compared to transurethral prostate resection as shown in prospective randomized trials. This prospective cohort study aims to evaluate if published results can be transferred into the clinical routine in a non-selected patient collective. This study includes all patients treated between September 2017 and June 2018 with Aquablation of the prostate. Patients have been evaluated prospectively for the perioperative course and early follow-up. Besides voiding parameter and symptom score, TRUS-volume change, ejaculatory function, and adverse events have been recorded. 118 consecutive patients have been treated in the given time. Aquablation could be carried out successfully in all patients. IPSS, QoL, Qmax, and PVR improved significantly after the procedure and continued to improve during 3-month follow-up. Mean OR time was 20min, TRUS volume decreased by 65%, and 73% of the patients retained antegrade ejaculation. Thirteen adverse events (> Clavien-Dindo I) occurred in 10 patients. The surgical ablation of the prostate using Aquablation achieved significant and immediate improvement of functional voiding parameters Qmax and PVR as well as symptomatic improvement of IPSS and QoL. Aquablation seems to be safe and effective with a low perioperative complication profile even in a non-selected group of patients.

Symmetric and antisymmetric vibration in elastic plate with voids immersed in a liquid

The problem of the symmetric and antisymmetric vibrations are attempted for the elastic plate with voids immersed in a liquid. The frequency equations are derived and deduced for the cases of plate wave, flexural and Rayleigh waves. It is also derived the cases when the liquid is replaced by vacuum/air. The two modes of vibration for the modified symmetric, antisymmetric, plate, flexural and Rayleigh waves in the considered medium are discussed. Numerically and analytically, the phase speeds and attenuations of symmetric and antisymmetric vibration, plate wave, flexural and Rayleigh waves are computed for a particular model. The effects of voids parameters on the phase speeds are also discussed.

Detection of void and metallic inclusion in 2D piezoelectric cantilever beam using impedance measurements

The aim of current work is to improve the existing inverse methodology of void-detection based on a target impedance curve, leading to quick-prediction of the parameters of single circular void. In this work, mode-shape dependent shifting phenomenon of peaks of impedance curve with change in void location has been analyzed. A number of initial guesses followed by an iterative optimization algorithm based on univariate method has been used to solve the problem. In each iteration starting from each initial guess, the difference between the computationally obtained impedance curve and the target impedance curve has been reduced. This methodology has been extended to detect single circular metallic inclusion in 2D piezoelectric cantilever beam. A good accuracy level was observed for detection of flaw radius and flaw-location along beam-length, but not the precise location along beam-width.

Bearing Capacity Characteristics and Failure Modes of Low Geosynthetic-Reinforced Embankments Overlying Voids

Reinforcement solutions can ensure that low geosynthetic-reinforced (LGR) embankments progressively subside instead of suddenly failing due to void collapse, which provides an early warning to allow surface refilling to be carried out. This study investigates the characteristics of the bearing capacity and failure modes of the LGR embankments overlying voids using large-deformation finite-element analysis and normalization method. The system as a whole has six distinct failure modes: the trapdoor, sidewall, combination of roof and sidewall, rotational roof, combination of roof and single sidewall, and slope failure modes. Five types of slip lines exist for the LGR embankment: the vertical, trapezoid, double-cambered, partial-vaulted, and vaulted slip lines. This study also presents the effects of influencing parameters (e.g., rupture strength of the reinforcement, location and size of the void, and height and shear strength parameters of embankment fills) on the ultimate bearing capacity of the system. Design charts are obtained to determine the required soil properties and evaluate the characteristics of the bearing capacity of the system.

Methodological Features of the Assessment of Economic Damage from Adverse Environmental Consequences in Conditions of Territories with a Developed Mining Complex

The main types of man-caused impact on the components of the natural environment in the mining complex are revealed. The specifics of the formation of damages from uncontrolled changes in the conditions for the existence of natural-technical systems due to exposure to hazardous factors, including depending on the parameters of man-made voids, are disclosed. In order to increase the level of greening of the activities of the enterprises of the GIC, in addition to the existing methods, a methodology for estimating damage from man-made impact, a methodology for estimating damage as a result of the formation of man-made emptiness of the subsoil and the emergence of emergencies in this regard, leading in some cases to catastrophic consequences.

Rayleigh-type wave in a nonlocal elastic solid with voids

Abstract The present work is concerned with propagation of surface waves in an isotropic homogeneous nonlocal elastic solid half-space with voids. Dispersion relation for Rayleigh-type surface wave has been derived, which is found to be complex in nature. The variation of phase speed and corresponding attenuation of Rayleigh-type wave against frequency, nonlocality and void parameters is computed for a specific model and presented graphically. It is shown that only one mode of Rayleigh-type wave exists, which faces a critical frequency same as the critical frequency of shear wave. The dispersion arises due to the presence of voids and nonlocality in the medium. The particle motion is elliptical and a tilt in the plane of particle motion occurs due to the presence of void parameter ‘τ’ in the medium. In the low frequency range, the variation in ellipticity is due to the presence of voids in the medium. Some particular cases have been deduced from the present formulation.

The outcomes of transurethral incision/resection of the prostate (TUIP/TURP) performed early after renal transplantation.

In the early period after renal transplantation, urinary retention stemming from bladder outlet obstruction (BOO) may directly affect graft success. The aim of this study was to evaluate the early and long-term outcomes of transurethral resection of the prostate (TURP) and transurethral incision of prostate (TUIP) procedures performed in the first month following RT due to BOO. Between February 2009 and March 2016, 38 male patients underwent TURP/TUIP due to BOO within the first 30 days of renal transplantation. The urodynamic and renal function assessment results of all patients were collected during the pre-and postoperative periods. All patients were followed up for a minimum of 12 months for short and long-term complications. The results were evaluated retrospectively. The mean age of the patients who underwent operations was 59.2±12 years. The median duration of dialysis was 41 months (range 0-180). Before the operation the mean serum creatinine (sCr) level was 1.8±0.7 mg/dL, the mean total PSA level was 1.6±1.1 ng/mL. Of the voiding parameters, the mean Qmax and Qave were measured as 8.2±4.5 mL/sec and 4.6±2.5 mL/sec, respectively. The median post-micturition residual urine (PMR) was 105 mL (range 10-400). TURP/TUIP operations were performed at a median of 19 days (range 8-30) after renal transplantations. None of the patients experienced major complications. In the early postoperative period, 5 patients (13.1%) developed urinary tract infection. The mean decrease in sCr in the first month following TURP/TUIP was 1.4±0.4 mg/dL (p<0.001). The mean Qmax (22.4±11.1 mL/sec), and Qave (11.7±5.4 mL/sec) increased significantly (p<0.001), while the median PMR (15 mL, range 0-205) decreased significantly (p<0.001). The mean follow-up period after the procedure was 46.8±23.3 months. During the follow-up period, 3 (7.8%) patients suffered from urethral stricture and 2 (5.2%) patients from bladder neck obstruction. In the surgical treatment of urinary retention arising from BOO in the first month following renal transplantation, TURP/TUIP yield safe and successful results. In addition, regarding the short and long term outcomes, these procedures may be safely performed with low morbidity.

Randomized Controlled Trial to Assess the Impact of Intraurethral Lidocaine on Urodynamic Voiding Parameters.

The aim of the study was to determine whether intraurethral anesthesia decreases voiding efficiency (VE; voided volume/(voided volume + residual volume)) and impacts other urodynamic parameters in healthy female volunteers during urodynamic studies. This was a randomized double-blind placebo-controlled study of asymptomatic women aged 18 to 60 years. Subjects completed a visual analog scale and baseline questionnaires to assess pain and lower urinary tract symptoms, respectively. They performed an uninstrumented baseline uroflow, followed by physiologic filling to 250 mL or greater. Subjects were randomized to receive 5 mL of intraurethral aqueous gel or 2% lidocaine gel and then underwent a second uninstrumented uroflow. They then completed complex cystometry, urethral pressure profilometry, and pressure-flow studies. Twenty-three randomized subjects (12 placebo, 11 lidocaine) were included. Baseline uroflow VE was similar between the placebo and lidocaine groups. After study drug administration, VE was not different between groups (89.3 [85.9-93.9] vs 89.5 [82.5-91.7], P = 0.74). There were also no differences between groups in visual analog scale scores, sensation during cystometry, maximum urethral closure pressure, or micturition parameters (maximum detrusor pressure and detrusor pressure at maximum flow). The placebo group had a lower percentage of interrupted flow pattern (0% vs 36%, P = 0.02) and a lower rate of increased electromyographic activity during micturition (25% vs 73%, P = 0.02). In this pilot study of 23 asymptomatic women, intraurethral administration of lidocaine did not decrease VE compared with placebo. The lidocaine group had a greater percentage of interrupted flow patterns and increased electromyographic activity during micturition.