Maximum Flow Rate Research Articles

Modifikasi Algoritma Edmonds Karp untuk Menentukan Aliran Maksimum Pada Jaringan Distribusi Air PDAM (Studi Kasus Jaringan Telaga Sari PDAM Giri Menang Mataram)

Clean water is the main and basic need for humans which is of concern to the government. Distribution network system is a very important part to delivering water to all consumers. The lack of water discharge distribution in several areas, especially at the end of the pipeline service, is cause by not optimal water distribution, the flow rate of sorce and leak in pipeline effect. This research has to analyze the optimal network model and determine the maximum flow rate from the PDAM pipeline using modified Edmonds Karp algorithm. Modified Edmonds Karp algorithm is a method for calculating maximum flow of a network. Based on analysis of modified Edmonds Karp algorithm there is a less efficient us of pipe in PDAM network and result of maximum flow from the network is 202,30 liter/second. This means it can be adding flow discharge to the water distribution pipe by PDAM for expedite the flow to consumer with the addition of flow should not exceed 202,30 liter/second.

Evaluation of extreme flow characteristics in the Casamance watershed upstream of Kolda using the IHA/RVA method

Understanding water availability is essential for the development and management of water resources, as well as for designing interventions for river health. Climate change/variability impacts the hydrology of a river system, which subsequently affects human and ecological health by altering the structure and function of the aquatic ecosystem. This study therefore aims to assess water availability and river health according to current and future climate scenarios in the Casamance watershed upstream of Kolda. Climate change is expected to increase hydrologic alterations from low (currently) to high (in the future), as revealed by the Indicators of Hydrologic Alteration (IHA) tool. Average annual water availability decreased, varying seasonally, and seasonal trends followed annual trends under Shared Socioeconomic Pathways (SSP) scenarios. In the basin, negative developments in minimum and maximum annual conditions are generally decreasing over the future period, compared to the reference period (1985-2014), with the exception of the minimum flow rate over 7 and 30 days on SSP 126 and the minimum flow rate over 30 days and the maximum flow rate 1, 3 and 7 days on SSP 585. In this SSP 585 scenario, the Mann Kendall test on the minimum flow rate and the flow rate maximum indicate the most significant downward trend with a risk of error of 0.05, with a Kendall tau varying from -0.45 m3/s/year to - 0.05 m3/s/year. For the minimum flow parameters, Kolda station shows negative Hydrological Alteration (HA) values for the high RVA category, which results in a decrease in low flow.

A single-stage dorsal inlay buccal mucosal graft placement through subcoronal vertical sagittal ventral urethrotomy without glansplasty for reconstruction of meatal stenosis, fossa navicularis, and distal penile urethral stricture: Our initial experience.

Reconstruction of fossa navicularis stricture (FNS) poses a challenge in providing acceptable functional and cosmetic outcomes. We describe our novel surgical technique and its short-term results. This urethroplasty technique is a single-stage dorsal inlay buccal mucosal graft placement with subcoronal vertical sagittal ventral urethrotomy without glansplasty. Twenty-one operated patients were followed up at 2 months and 6 months postoperatively. We studied the functional outcome of the International Prostate Symptom Score, quality of life (QoL) score, maximum flow rate, postvoid residual (PVR) urine, and reconstructed urethral luminal caliber. Sexual function was studied via a brief male sexual function inventory. Hypospadias objective score evaluation (HOSE) was used to assess the cosmesis. Patient satisfaction was evaluated using the global response assessment score (GRA). FNS is seen commonly associated with lichen sclerosus (n = 12). Nine patients had stricture that extended into the distal penile urethra. The mean stricture length was 2.76 cm. At the end of the study, a significant improvement in mean IPPS (18.81), mean QoL score (2.25), mean Qmax (20.94 mL/s), mean PVR (103.05 mL), and mean urethral caliber (16.06 Fr) were noted. No difference in sexual drive and erectile function but significant improvement in ejaculation was noted. All patients had single-stream urine, reconstructed urethral caliber ≥16Fr, HOSE ≥14, and GRA ≥2 at 6 months. Except for two patients, all had vertical slit-like meatus. This technique is feasible, with good cosmetic, functional, and subjective outcomes with marked patient' satisfaction.

Condensation and droplet characteristics in hydrogen recirculation ejectors for PEM fuel cell systems

The hydrogen recirculation ejector plays a pivotal role in proton exchange membrane fuel cell systems. Nevertheless, a comprehensive grasp of the intricate two-phase flow characteristics within hydrogen recirculation ejectors remains elusive. This investigation delves into the condensation and droplet behaviors of an ejector designed for a 100 kW fuel cell stack. The analysis relies on a two-phase flow model that takes into account both homogeneous and heterogeneous condensation. The findings reveal that homogeneous condensation nuclei manifest within the mixing chamber when the stack power surpasses 31 kW. The average median diameter of homogeneous droplets at the ejector outlet measures 0.367 μm, whereas that of heterogeneous droplets stands at 1.265 μm, signifying a 26.5 % augmentation compared to their initial size. Additionally, two crucial factors impact droplet size: residence time and subcooling degree. At the 100 kW condition, the droplet residence time is a mere 0.272 ms, yielding a meager droplet flow rate of merely 1.79 mg/s. In contrast, at the 53 kW condition, the downstream of the mixing chamber exhibits the maximum subcooling degree, resulting in the maximum droplet flow rate of 22.12 mg/s. A temperature elevation of 2.68 K at the ejector outlet is observed due to the latent heat of condensation. Furthermore, condensation has a marginal impact on the entrainment ratio, with the most significant reduction being 4.18 %, averaging at 1.42 %.

Performance boost of a commercial air-to-air plate heat recovery unit by mesh-net insert; thermal-frictional, economic, and effectiveness-NTU analysis

This research proposes, tests, and comprehensively investigates the application of mesh-net to increase the efficiency of any air-to-air plate heat exchanger (mainly as a building heat recovery unit). The idea is tested through a commercial heat-recovery unit and all parameters including Nusselt number, pressure drop, friction factor, thermal performance factor, effectiveness, number of thermal units, pumping power and economical profitability are comprehensively investigated and reported with and without mesh-net insert. In economic evaluation the price of electricity and type of building heating system (resistance heater, heat pump and so on) are considered. In the maximum air flow rates, the overall heat transfer coefficient is enhanced from 24 to 36 W/m2K. Nusselt number increases up to 75 % depending on air flow rate. The economic results were found very interesting, and even by paying further fan power due to the higher pressure drop, the economic profitability is positive when the building heating system is resistance heater or heat pump with lower coefficient of performance. The profitability of the mesh net insert is higher for the region with higher electricity price. This means the gained recovered heat overcomes the further energy required for pumping power. Nonetheless, final decision making from pure economic viewpoint depends on the desired supply air flow rate, type of heating system and local price of electricity.

Optimization of gas extraction of producing wells to increase the efficiency of condensate production

The article discusses ways to increase the efficiency of condensate production due to the optimal distribution of gas flows between producing wells. For a large number of wells, the solution of this problem becomes nontrivial and requires special methods of nonlinear optimization. The main aim of research is obtaining accurate solutions to the problem of optimizing condensate production using direct dependencies between gas and condensate production. The minimum set of reliable field information has been determined, which allows solving the problem of optimal distribution of gas production between wells at the maximum condensate flow rate. An optimization problem is formulated for this model. The conditions under which the initial problem is divided into a system of optimization subtasks for subgroups of wells are considered. By the method of pairwise optimization, analytical expressions were found for optimal ratios of gas flow rates in a group of wells. Based on the expressions obtained, an algorithm has been developed for the exact solution of the problem of short-term optimization of the well operation mode.

Design and Analysis of a Cardioid Flow Tube Valveless Piezoelectric Pump for Medical Applications.

Piezoelectric pumps play an important role in modern medical technology. To improve the flow rate of valveless piezoelectric pumps with flow tube structures and promote the miniaturization and integration of their designs, a cardioid flow tube valveless piezoelectric pump (CFTVPP) is proposed in this study. The symmetric dual-bend tube design of CFTVPP holds great potential in applications such as fluid mixing and heat dissipation systems. The structure and working principle of the CFTVPP are analyzed, and flow resistance and velocity equations are established. Furthermore, the flow characteristics of the cardioid flow tube (CFT) are investigated through computational fluid dynamics, and the output performance of valveless piezoelectric pumps with different bend radii is studied. Experimental results demonstrate that CFTVPP exhibits the pumping effect, with a maximum vibration amplitude of 182.5 μm (at 22 Hz, 100 V) and a maximum output flow rate of 5.69 mL/min (at 25 Hz, 100 V). The results indicate that a smaller bend radius of the converging bend leads to a higher output flow rate, while the performance of valveless piezoelectric pumps with different diverging bends shows insignificant differences. The CFTVPP offers advantages such as a high output flow rate, low cost, small size for easy integration, and ease of manufacturing.

Modified laparoscopic simple prostatectomy combined with temporary internal iliac arteries clamping and urethrocystoanastomosis for large-volume benign prostatic hyperplasia: evaluation of efficacy and safety

Introduction. Laparoscopic simple prostatectomy is the method of choice for surgical treatment of large-volume benign prostatic hyperplasia (BPH). However, the existing limitations of standard approaches are the reason for the development of new modifications.Objective. To evaluate the efficacy and safety of a modified laparoscopic simple prostatectomy (LSP), supplemented by temporary internal iliac arteries (IIA) clamping and vesicourethral anastomosis (VUA).Materials & methods. This multicenter open study included 195 patients (mean age 68.1 ± 6.4 years) who underwent LSP combined with temporary IIA clamping and VUA. The primary efficacy criterias during one follow-up year were the severity of urinary symptoms (IPSS), quality of life, maximum flow rate and post-void residual volume. All complications that developed during the 12-month postoperative follow-up period were registered. Statistical calculations were performed using IBM SPSS 23.2 software.Results. The average surgery time was 91.5 ± 23.2 minutes. Complications of Clavien-Dindo I, II, III grades were noted in 1.0%, 1.0% and 3.6% of patients, respectively; no complications of group IV developed. The mean bed-days were 5.2 ± 1.5 days, the decrease in hemoglobin was 0.6 ± 1.1 g/dL. No patient needed to use an irrigation system. Based on the results of 12 months postoperative follow-up, positive dynamics was established for average IPSS score (p = 0.003), QoL (p = 0.035), maximum urine flow rate (p = 0.012), residual urine volume (p = 0.004). The maximum urine flow rate one year after surgery reached 24.6 ± 2.8 ml/s, the post-void residual urine volume was 15.1 ± 11.9 ml, the average IPSS score was 9.1 ± 1.5, and the QoL score – 1.0 ± 0.7. During the 12-month follow-up period, a low amount of long-term complications was noted in 4 (2.1%) cases: 3 (1.6%) patients had stress urinary incontinence, 1 (0.5%) patient had bladder neck contracture.Conclusion. Modified LSP combined with temporary IIA clamping and VUA is associated with favorable efficacy and safety profile of the intervention in patients with large-volume BPH.

Efficacy of GreenLight laser prostatectomy in urinary retention.

The objective of our study was to evaluate the efficacy and durability of GreenLight laser prostatectomy for the management of acute urinary retention (AUR) and chronic urinary retention (CUR) and to determine outcomes compared to patients without preoperative urinary retention (UR). We conducted a retrospective study of prospectively collected data from individuals who underwent GreenLight laser prostatectomy at our institution from May 2018 to July 2022. Patient demographics and outcome measures were recorded, including indications for the procedure, median urinary volume drained, or median postvoid residual urine volume (PVR) before catheterization or GreenLight laser prostatectomy. CUR was defined as PVR >300 mL in males able to void and initial catheter drainage >1000 mL in males unable to void in the absence of pain. All patients had postoperative followup visits at one, three, six, and 12 months. Our evaluation included the International Prostate Symptom Score (IPSS), quality-of-life (QoL) assessment, maximum urinary flow rate (Qmax), PVR, and catheter-free status. One hundred sixty-eight males who underwent GreenLight laser prostatectomy were included in our study. The UR group consisted of 88 patients (50 AUR and 38 CUR), and the lower urinary tract symptoms (LUTS) group was comprised of 80 individuals. There were no statistically significant differences between the AUR and CUR subgroups regarding demographics. The UR group had a significantly higher age and a significantly higher postoperative catheterization time compared to the LUTS cohort. The CUR subgroup had a significantly higher PVR at one, three, and six months compared to the AUR subgroup, although other outcome measures were similar between the two cohorts. During three- and six-month followup visits, the UR group had a significantly higher PVR than the LUTS cohort. At 12 months postoperative, the LUTS group had a higher catheter-free rate than the UR group (p=0.001). The successful first trial of void (TOV) rate for the UR and LUTS groups were 83% and 80%, respectively. At 12-month followup, the catheter-free rate for the UR and LUTS cohorts was 87.5% and 100%, respectively. GreenLight laser prostatectomy is an effective and durable treatment for UR, with a high catheter-free rate and comparable outcomes when performed to manage LUTS.

Surgical treatment of genital prolapse in combination with endometrial hyperplastic processes in postmenopausal women

Aim. To study the long-term results of surgical treatment of postmenopausal patients with genital prolapse III and IV according to the POP-Q classification in combination with endometrial hyperplastic processes and to assess their quality of life.
 Materials and methods. Fifty one elderly and senile patients with grade III–IV prolapse according to the POP-Q classification in combination with endometrial hyperplastic processes. 2 groups were formed: 1st – 21 patients after one-stage vaginal extirpation of the uterus with appendages and unilateral sacrospinous fixation of the vaginal stump with a synthetic endoprosthesis-tape in combination with reconstruction of II and III levels of pelvic floor support according to DeLancey; 2nd – 30 patients after one-stage vaginal extirpation of the uterus with appendages and median colporrhaphy using the Lefort and Neugebauer technique.
 Results. The study was evaluated 1–7 years after surgical treatment. The average age of patients at the time of surgery in group 1 was 63.12±4.32 years, in group 2 – 74.2±3.28 years. The number of women with somatic pathology in the 1st group was 1.7 times less in percentage terms than in the 2nd. The disappearance of symptoms of an overactive bladder after surgery was noted by 4 (50.0%) of 8 patients of the 1st group and 4 (26.7%) of 15 women of the 2nd. Uroflowmetry after surgical treatment showed an increase in the maximum flow rate (Qmax) and a decrease in the volume of residual urine (Vom) in both groups (p0.001). Recurrence of genital prolapse was detected in the apical region in 1 (4.8%) woman, prolapse of the anterior vaginal wall in 1 (4.8%). There were no recurrences of genital prolapse in the 2nd group. A significant improvement in the quality of life after surgery, according to the results of processing the PFDI-20 questionnaire, was noted by 19 (90.5%) women in the 1st group and 29 (96.7%) – in the 2nd.
 Conclusion. The long-term results of the proposed operational benefits have shown satisfactory results and can be successfully used in the elderly and senile age. The choice of the volume of surgery taking into account age, sexual activity, concomitant gynecological and somatic pathology reduces the number of complications and improves the results of surgical treatment in this category of patients.

Electrostatic-hydraulic coupled soft actuator for micropump application

The development of a soft actuator with high displacement is crucial for the effective operation of micropumps, ensuring a high fluid pump rate. This study introduces an innovative approach by presenting the design and fabrication of a novel electrostatic-hydraulic coupled soft actuator for a micropump within a microfluidic system. This pioneering soft actuator, leveraging electrostatic-hydraulic coupling, showcases a unique solution to enhance the performance of micropumps. The versatility of such a soft actuator makes it particularly promising for biomedical applications. The actuator comprises dielectric fluid in an elastomeric shell and electrodes to form the out-of-plane fluid-amplified displacement. This displacement amplification was used to generate a pumping actuation in the micropump. The actuator was characterized in terms of dielectric fluid volume, electrode size, temporal response, and amplification displacement. The soft actuator showed a maximum amplified displacement of 0.51 mm at 10 kV of the applied voltage, but a higher voltage caused a dielectric breakdown. Moreover, the actuator demonstrated the ability to operate at frequencies of 0.25 Hz and 0.1 Hz. The results of the study indicate that the fabricated electrostatic-hydraulic coupled soft actuator is a dependable and effective method of actuation for a micropump in a microfluidic system. The experimental characterization of the micropump revealed a maximum flow rate of 2304 μl min−1.

Design, modeling and experimental research of a multi-mode, fast-response piezoelectric control valve

To realize the precise regulation and fast response of the valve, a piezoelectric control valve with a simple and compact structure, and easy control is proposed. The control valve is divided into the valve core that consists of a sandwich piezoelectric transducer and a valve body. When a single excitation signal is applied to the transducer, the longitudinal vibration mode of the valve core is excited. The valve is opened due to the liner reciprocating motion of the end of the valve core. By adjusting the frequency of the excitation signal, the vibration mode of the transducer is switched between the first three modes of longitudinal vibration, which in turn adjusts the water output of the valve. Compared with the single-mode valve, the piezoelectric control valve has three working modes. Therefore, it has different adjustment precision and range for each mode. First, the electromechanical coupling model of the valve core and the mechanical model of the valve body are established by using the transfer matrix method. By analyzing the dynamic characteristics of the piezoelectric valve, the structure parameters of the valve core and valve body are optimized. Secondly, the prototype of piezoelectric valve is manufactured and assembled, and the validity of the proposed theoretical model is verified by the vibration measurement experiments. Finally, the flow performance and response speed of the piezoelectric valve are measured by experiments. The results show that the maximum pressure of the valve is 1 MPa when the assembly pre-pressure is 983 N. A sinusoidal-signal has the best excitation effect. Under the experimental conditions of sinusoidal excitation, a driving voltage amplitude of 250 V, and pressure of 1 MPa, the optimal driving frequencies of the piezoelectric valve in the first three operating modes are 33.8 kHz, 42.2 kHz, and 83 kHz, and the corresponding maximum flow rates are 3.3 mL/min, 1.15 ml/min, and 0.445 ml/min, respectively. The response performance of the piezoelectric valve is tested, indicating that the prototype can achieve stable operation within 3.5 ms after being powered on, and stop working within 5 ms after being powered off. The piezoelectric valve has good response characteristics and flow control ability, which has potential applications in the field of biomedicine.

Qualification of Compensatory Test Methods Involving Pressure Increase in the VVER Containment System

In general, containment leakage testing of nuclear power plants with VVER reactors by elevated pressures using the compensatory leakage detection method (CLDM) can be performed at pressures and pressure increase rates higher than those stipulated by the regulations using the absolute pressure method (AP method). Elevated pressures and pressure increase rates under certain conditions can violate safety limits of the containment systems and/or decrease the reliability/life of containment structures and equipment. These factors determine the need to qualify the CLDM to promote conditions for reliability and safety. A non-stationary thermodynamic model of the qualification conditions for CLDM testing of the containment was developed. The criteria for CLDM qualification conditions are the maximum allowable pressure and pressure increase rate during testing. The CLDM condition for recording leakage in the containment is pressure stabilization in the containment systems. Based on the developed CLDM thermodynamic model, it was established that the containment leakage rate is determined by the flow rate of air entering the containment systems and by the thermodynamic state of the air inside and outside the containment systems. The established qualification conditions were used to determine conditions for the minimum recorded leakage sizes within CLDM and the maximum allowable ambient air flow rates and test duration. A prerequisite for justifying the qualification and implementation of the CLDM is to revise/amend regulatory and technical requirements for the maximum allowable pressure and pressure change rate in the containment systems and for the conditions for disconnecting containment systems passive heat removal systems (if any) during testing.

Investigation of baffle configurations on the water disinfection efficiency using ultraviolet C light-emitting diodes

ABSTRACT In this study, the effect of baffle configuration on the water disinfection efficiency of a planar photoreactor equipped with ultraviolet C light-emitting diodes (UV-C LEDs) was investigated. The results indicated that the configuration of the baffles influenced the hydrodynamics inside the flow channel and thus affected the microbial trajectory, and exposure time. Accordingly, a modified serpentine configuration was developed to enhance the UV light exposure of microbes in water and improve the reactor performance for microbial inactivation. According to the simulation results, the quarter-circle baffles used in the modified serpentine configuration increased the microbial path length along the flow channel. However, because the cross-sectional area of the flow channel decreased, this configuration increased the water velocity. A modified serpentine configuration with a baffle radius of 5 mm achieved the longest microbial exposure time and highest inactivation value for Escherichia coli. At a water flow rate of 160 mL/min, this configuration achieved a UV fluence of 15.2 mJ/cm2 and an inactivation value of 3.8 log, which were approximately 22% and 0.4 log higher than those obtained with the traditional serpentine configuration, respectively. In addition, the maximum water flow rate at which the UV reactor achieved an inactivation value of 4.0 log was 154 mL/min at a baffle radius of 5 mm. This flow rate was 11.5% higher than that obtained with the traditional serpentine configuration. These close agreements between the experimental and simulation results confirmed the strong capability of the proposed modified serpentine configuration to improve reactor performance.

The Time-Varying Variation Characteristics of Methane during Nitrogen Injection Process: An Experimental Study on Bituminous Coals

The existing research on CH4 displacement by N2 mainly focuses on the gas injection displacement mechanism and the factors affecting displacement efficiency. And most of them are theoretical analyses at the model level or multifactor analyses at the simulation test level, while there are few targeted physical simulation tests and quantitative analyses. Given the above problems, the experiment system was used to study the gas migration evolution law and time-varying characteristics of CH4 displacement by N2 in coal under different injection pressures. The experimental results show that the whole process of CH4 displacement by N2 can be divided into three stages: stage I (original equilibrium stage); stage II (dynamic balance stage); stage III (new equilibrium stage). The concentration of CH4 and N2 presents an opposite variation trend, and the variation rate of CH4 and N2 increased first and then decreased. The breakthrough time was 50 minutes, 45 minutes, 35 minutes, 25 minutes, and 20 minutes, respectively, under different injection pressures. The displacement efficiency increased with the injection pressures, while the replacement ratio decreased with the injection pressures. The maximum flow rate of CH4 was 0.085 mL/min, 0.110 mL/min, 0.130 mL/min, 0.222 mL/min, and 0.273 mL/min, respectively, under different injection pressures. The accumulated production of CH4 was 3.59 mL, 3.91 mL, 4.39 mL, 5.58 mL, and 5.94 mL, respectively, under different injection pressures. The effective injection pressure range was 1.6~2 MPa. This research can provide a reference for the theoretical research of N2-ECBM-related technology in low permeability reservoirs and the selection of injection pressure in the field technology implementation.

Minimally invasive connective water vapor energy method for benign prostatic hyperplasia.

The Rezūm system has emerged as a promising treatment option for benign prostatic hyperplasia (BPH) by employing endoscopic removal of prostate tissue. This meta-analysis aimed to evaluate the benefits and drawbacks of Rezūm therapy in recent studies. A systematic literature search was conducted in EMBASE, PubMed, and the Cochrane Library databases until December 2021, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search utilized keywords such as water vapor thermal therapy, Rezūm, convective water vapor thermal therapy, and convective radiofrequency water vapor thermal therapy. A total of 21 studies were included in the analysis, comprising 5 prospective randomized studies, 2 case series, 2 randomized controlled trials, 1 crossover study, and 11 retrospective studies. The collective sample involved 2090 patients with a mean follow-up period of 14.42 ± 18.08 (1-72) months and a mean age of 68.12 ± 4.79 years. Significant improvements were reported in the International Prostate Symptom Score (IPSS), quality of life (QoL), maximal flow rate (Qmax), postvoid residual urine volume (PVR), prostate volume (PV), and International Erectile Index Function (IIEF) values. Unlike other BPH treatments that often require general or regional anesthesia, the connective water vapor energy system can be administered with sedo-analgesia and local anesthesia, potentially leading to improved sexual function scores. Considering the relief of symptoms, Rezūm therapy may serve as a viable alternative to transurethral surgery for patients with prostate volumes ranging from <30 to >80 cc.

Factors Influencing Postoperative Overactive Bladder after Adjustable Trans-Obturator Male System Implantation for Male Stress Incontinence following Prostatectomy.

We aimed to determine the risk factors for postoperative overactive bladder (OAB) in patients treated with an adjustable trans-obturator male system (ATOMS) for stress incontinence after radical treatment of prostate cancer. A prospective study was performed on 56 patients implanted with an ATOMS for PPI. Clinical and urodynamic information was recorded before and after ATOMS implantation. We built a multivariate model to find out the clinical and urodynamic factors that independently influenced postoperative OAB and the prognostic factors that influenced the efficacy of medical treatment of OAB. We found that the clinical risk factors were the preoperative intensity of urinary incontinence (number of daily pads used and amount of urinary leakage), International Consultation on Incontinence Questionnaire (ICIQ) score, postoperative number of ATOMS adjustments, final cushion volume, and incontinence cure. The urodynamic data associated with OAB were cystometric bladder capacity, voided volume, volume at initial involuntary contraction (IC), maximum flow rate, bladder contractility index (BCI), and urethral resistance (URA). The prognostic factors for the efficacy of oral treatment of OAB were the volume at the first IC (direct relationship) and the maximum abdominal voiding pressure (inverse relationship). The multivariate model showed that the independent clinical risk factors were the daily pad count before the implantation and the ICIQ score at baseline and after treatment. The independent urodynamic data were the volume at the first IC (inverse relationship) and the URA value (direct relationship). Both predictive factors of treatment efficacy were found to be independent. Detrusor overactivity plays an important role in postoperative OAB, although other urodynamic and clinical factors such as the degree of urethral resistance and abdominal strength may influence this condition.

Biomimetic urine flow control can preserve bladder function in patients with indwelling catheterization.

For patients with long-term indwelling catheterization, bladder function will be affected. It is necessary to explore whether biomimetic urine flow control (BUFC) can improve bladder function in patients undergoing indwelling catheterization. A retrospective, data-only, cohort study was carried out. The patients admitted to the intensive care unit, who had retained catheter and been continuously using a urodynamic monitoring system for over 30 days were selected. They were divided into 2 groups based on whether they were using BUFC function. The urodynamic monitoring data of the 2 groups were compared and analyzed. A total of 30 patients were included in the final analysis, including 15 in the BUFC group and 15 in the unobstructed group. The Urinary Volume and maximal urinary flow rate of the unobstructed group showed a continuous downward trend, while the BUFC group remained stable, and there was a statistical difference (P < .05) between the 2 groups since day 20. The bladder ultrasound imaging showed that the bladder volume of the BUFC group did not decrease significantly on the 30th day. BUFC technology, which provided by a urodynamic monitoring system, has potential protective effects of the bladder function after indwelling catheterization.

Performance improvement and noise reduction analysis of multi-blade centrifugal fan imitating long-eared owl wing surface

This research was inspired by the long-eared owl's ability to fly silently. For the first time in this study, a wind turbine blade is designed to mimic the wing surface and the leading edge of the long-eared owl. The commonly used two-dimensional blade profile in previous studies is replaced by a more effective three-dimensional profile. This change leads to improved aerodynamic performance of the multi-blade centrifugal fan and reduced noise levels. The airfoil and leading edge profile parameters of the long-eared owl were extracted and utilized. These parameters were used to develop a fitting formula based on their correlation. This formula facilitated the design and optimization of a bionic blade (B-Blade). The results indicate a 4.1% enhancement in the maximum flow rate compared to the original blade fan, alongside a noise reduction of 1.3 dB(A) under identical static pressure conditions. An examination of the internal flow, noise, and sound source characteristics of both fan types was conducted, elucidating the aerodynamic noise mechanism. Fan noise propagation showed pronounced dipole sound source traits. The sound source area at the B-Blade fan's inlet and the volute tongue was more compact, leading to a decrease in mid-low frequency discrete noise. The sound source intensity was also diminished. The B-Blade fan also ameliorated the flow distribution at the impeller outlet, reducing the unstable interaction between the impeller and volute tongue, thereby effectively diminishing noise.

A Review of Optimal Design for Large-Scale Micro-Irrigation Pipe Network Systems

Micro-irrigation pipe network systems are commonly utilized for water transmission and distribution in agricultural irrigation. They effectively transport and distribute water to crops, aiming to achieve water and energy conservation, increased yield, and improved quality. This paper presents a model for the scaled micro-irrigation pipeline network system and provides a comprehensive review of the fundamental concepts and practical applications of optimization techniques in the field of pipeline network design. This paper is divided into four main sections: Firstly, it covers the background and theoretical foundations of optimal design for scaled micro-irrigation pipeline network systems. Secondly, the paper presents an optimal design model specifically tailored for scaled micro-irrigation pipeline networks. And then, it discusses various optimization solution techniques employed for addressing the design challenges of scaled micro-irrigation pipeline networks, along with real-world case studies. Finally, this paper concludes with an outlook on the ongoing research and development efforts in the field of scaled micro-irrigation pipeline network systems. In addition, this paper establishes a fundamental model for optimizing pipeline networks, to achieve minimum safe operation and total cost reduction. It considers constraints such as pipeline pressure-bearing capacity, maximum flow rate, and diameter. The decision-making variables include pipeline diameter, length, internal roughness, node pressure, future demand, and valve placement. Additionally, this paper provides an extensive overview of deterministic methods and heuristic algorithms utilized in the optimal design of micro-irrigation pipeline networks. Finally, this paper presents future research directions for pipeline network optimization and explores the potential for algorithmic improvements, integration of machine learning techniques, and wider adoption of EPANET 2.0 software. These endeavors aim to lay a strong foundation for effectively solving complex and challenging optimization problems in micro-irrigation pipeline network systems in the future.