Drain Line Research Articles

Определение диссипативных потерь в гидравлическом приводе газораспределительного механизма двигателя внутреннего сгорания

Controlling the opening and closing times of intake and exhaust valves can improve the efficient parameters of an internal combustion engine and reduce the toxicity of combustion products. The valves are moved by an electronically controlled hydraulic drive. The energy consumption for the operation of a hydraulic valve drive is greater than when using a traditional mechanical drive. The dissipative energy losses in the accumulator one-way hydraulic valve drive are investigated. The working fluid of the hydraulic drive is SAE 5W-30 motor oil. The oil pressure behind the pump is 8 MPa, the diameter of the hydraulic cylinder is 16 mm. The main items of energy consumption are identified, and a methodology for their determination is proposed. The assessment of the efficiency of the hydraulic drive was based on the law of conservation of energy. To determine energy costs, a hydraulic drive model was compiled in the Simulink environment. A law of valve movement similar in shape to trapezoidal was obtained. The maximum speed of valve movement during the opening process is 4 m/s, during the closing process 3.8 m/s. During the period when the valve is held near the maximum lift of 14 mm, free oscillations with an amplitude of about 1 mm are observed. The energy consumption for a single actuation of the valve, which has a progressively moving mass of 0.5 kg, amounted to 25.9 J. Of this, a little more than 70% is spent on filling the hydraulic cylinder with liquid, the rest is spent when emptying it. As a result of throttling the fluid flow in the hydraulic cylinder rod stroke limiter and hydraulic brake, 56% of the energy is lost. Large energy losses are observed between the hydraulic accumulators and the hydraulic cylinder. When the cylinder is filled, 21.1% is lost here, and when it is emptied, 10.4%. Increasing the capacity of the supply and drain lines between hydraulic accumulators and hydraulic cylinders allows you to increase the speed of opening and closing valves. The main ways to increase the energy efficiency of the drive are to shift the hydraulic accumulators to the hydraulic cylinder, increase the diameter of the connecting lines, and increase the throughput of the solenoid valves.

Effectiveness of Chemical Sanitizers against Salmonella Typhimurium in Nutrient Film Technique (NFT) Hydroponic Systems: Implications for Food Safety, Crop Quality, and Nutrient Content in Leafy Greens.

Hydroponic farming systems play an increasingly important role in the sustainable production of nutrient-rich foods. The contamination of surfaces in hydroponic fresh produce production poses risks to the food safety of crops, potentially endangering public health and causing economic losses in the industry. While sanitizers are widely used in commercial hydroponic farms, their effectiveness against human pathogens on surfaces and their impact on plant health and quality are not known. In this study, we evaluated the efficacy of chemical sanitizers in eliminating Salmonella Typhimurium from inanimate surfaces in commercial hydroponic Nutrient Film Technique (NFT) systems. Further, we assessed the impact of sanitizers on the yield, quality, and nutritional value of lettuce and basil. Sanitizers (Virkon, LanXess, Pittsburgh, PA, USA; SaniDate 12.0, BioSafe Systems, East Hartford, CT, USA; KleenGrow, Pace Chemical Ltd., Delta, BC, Canada; Green Shield, United Labs Inc., St Charles, IL, USA; Zerotol, BioSafe Systems, East Hartford, CT, USA; Bleach, Pure Bright, ON, Canada) were tested against Salmonella Typhimurium inoculated on NFT surfaces (nutrient reservoir, growing channels, top covers, drain lines). The effective treatments were then tested for their impact on lettuce and basil in a split-plot experiment conducted in commercial NFT units. Crop yield, color, and nutrient content (chlorophyll and carotenoids) were measured throughout the crop life cycle. While all quaternary ammonium compounds (QAC), SaniDate 12.0 (200 ppm), Zorotol (5%), and Virkon (1%) eliminated Salmonella Typhimurium from commercial NFT surfaces, chlorine-based sanitizer treatments were statistically similar to water treatments on most surfaces. All chemical sanitizers impacted the yield, color, and nutritional value of lettuce and basil. SaniDate 12.0 (200 ppm) was the least detrimental to crops and was identified as a potential candidate for further validation in commercial hydroponic settings. The findings of this study will be translated into recommendations for the industry and will contribute to the development of future food safety guidelines and policies.

Continuous Urine Output-Based Alert Identifies Cardiac Surgery–associated Acute Kidney Injury Earlier Than Serum Creatinine: A Prospective and Retrospective Observational Study

Objective(s)Acute kidney injury (AKI) is defined and staged by reduced urine output (UO) and increased serum creatinine (SCr). UO is typically measured manually and documented in the electronic health record, making early and reliable detection of oliguria-based AKI and electronic data extraction challenging. We investigated the diagnostic performance of continuous UO, enabled by active drain line clearance, based alerts (Accuryn AKI Alert), compared to AKI stage 2 SCr criteria and their association to length of stay (LOS), need for continuous renal replacement therapy (CRRT), and 30-day mortality. DesignProspective and retrospective observational study. SettingNine tertiary centers. ParticipantsCardiac surgery patients. InterventionsNone. Measurements and Main Results522 patients were analyzed. AKI stages 1, 2, and 3 were diagnosed in 32.18%, 30.46%, and 3.64% of patients based on UO compared to 33.72%, 4.60%, and 3.26% of patients using SCr, respectively. Continuous UO-based alerts diagnosed stage ≥1 AKI 33.6 (IQR= [15.43, 95.68]) hours before stage ≥2 identified by SCr. A SCr-based diagnosis of AKI stage ≥2 has been designated a Hospital Harm by the Centers for Medicare & Medicaid Services. Using this criterion as a benchmark, AKI alerts had a discriminative power of 0.78. AKI Alert stage 1 was significantly associated with increased ICU and hospital LOS and CRRT, and stage ≥2 alert with mortality. ConclusionsAKI Alert based on continuous UO, enabled by active drain line clearance, detected AKI stages 1 and 2 before SCr. Early AKI detection allows for early kidney optimization, potentially improving patient outcomes.

Raised Ge-Source with n+ pocket and recessed drain line TFET: A proposal for biosensing applications

In this paper, we present a novel raised Ge-source with an n+ pocket and recessed drain line Tunnel Field-Effect Transistor (TFET). It offers enhanced performance for potential biosensing applications. The proposed device comprises a Ge source with a low bandgap, an n+ pocket, and a larger tunneling area. This results in improved performance characteristics: an ON current of 54.27 μA/μm, an ON-current to OFF-current ratio of 1.5 × 1012, and an average subthreshold swing of 21.3 mV/dec. The recessed drain design eliminates ambipolarity, further enhancing performance. The study thoroughly investigates biosensing capabilities, including DC and transient analyses, evaluating charged and neutral biomolecules (uricase, biotin, 3-aminopropyltriethoxysilane, DNA, keratin, and gelatin). The proposed biosensor, with a higher drain current sensitivity of 1.2 × 109 for gelatin (k = 12) and 3.05 × 108 for keratin (k = 8), outperforms existing approaches, making our proposed biosensor a compelling choice for future low-power biomedical applications.

Flexible multi-electrode neural probe using active-matrix design of transistor array

To realize a brain-machine interface, a neural probe is one of key hardware. For the neural probe, a high spatial resolution of an electrode array, high electrical sensitivity, and mechanical flexibility remain challenging and essential issues. In regard to these, implantable multi-electrode neural probe employing active-matrix design with field effect transistors (FETs) can attract attention due to their advantages of a suitable integration density and good signal-amplifying abilities. Therefore, we developed a flexible multi-electrode neural probe employing an active-matrix design based on a two-transistor (2T) scheme for application to a flexible neural signal recording probe. As a proof of concept, 4 × 8 electrode array (32 channels) with TFTs was demonstrated. For the flexible active-matrix design, back-gate indium-gallium-zinc-oxide (IGZO) thin film transistors (TFTs) were fabricated on a polyimide (PI). The TFTs used here can amplify signals and achieve a switching function to drive the active matrix. The probe structure was encapsulated by the same PI material again to achieve flexibility with good reliability, as the sandwich-like structure can induce a neutral plane on the TFT and electrodes. To ensure a high signal-to-noise ratio, the structural and process parameters of the TFT were studied. Among different annealing times and temperatures of the IGZO TFT, the optimized annealing condition of the TFT was found to be 250 °C a 1 hour on a flexible substrate. The width over length of the transistors was optimized to 50 μm/10 μm, and the field-effect mobility was 8.33 cm2/V·s. The on current was 2.28 × 10−6 A at a low driving voltage of 5 V. The transconductance was 2.16 μS and the threshold voltage (Vth) was 1.6 V. By applying 5 V, the switching TFT was turned on, and a doubly amplified signal (> 2.4 times) could be measured on the drain line. The electrode array probe with the active-matrix design can use for accurate neural recording and herald a new generation of flexible neural probes with high spatial resolutions.

Nonlinear Time-domain signal and noise analysis of an active CRLH transmission line for millimeter-wave frequencies

In this paper, time domain signal and noise behavior of an active CRLH transmission line was investigated in the nonlinear regime at millimeter wave frequencies. In this structure, the transistor is considered as three coupled transmission lines and all three drain,gate and source lines are CRLH transmission lines. The left-handed element values for the active CRLH transmission line are calculated in such a way that the phase cancellation effect and dispersion of the CRLH transmission line are reduced. In order to model this active CRLH transmission line, with the assumption of wave propagation in the form of Quasi-TEM, the distributed modeling method is used to extract stochastic telegraphic equation (STE) in the non-linear regime. To model noise sources in the non-linear regime, the Wiener process and modulation functions have been used to model white noise in the nonlinear regime and in the time domain. By applying the finite integration method to stochastic telegraphic equation, the behavior of the signal and noise of the active structure CRLH has been compared with a line of active structure RH and the obtain results of the numerical method have been verified with the results of the Agilent ADS software.

Diagnostics of hydraulic cylinders of road construction machines using hydraulic prop

AIMS: to develop a new method for diagnosing hydraulic cylinders. Apply a hardware-diagnostic complex for testing a hydraulic cylinder. To analyze the graphs of the pressure dependence on time, as well as to identify the main diagnostic indicator characterizing the technical condition of the hydraulic cylinder.
 METHODS: The pressure, flow rate and temperature of the working fluid are currently used as diagnostic indicators used to diagnose the technical condition of hydraulic systems as a whole and its individual elements. Changes in these indicators allow us to judge the state of the hydraulic system of the construction machine. However, these indicators help to assess the current state and, as a rule, do not provide an opportunity to assess the residual resource of hydraulic system elements.
 RESULTS: The technical condition and residual life of hydraulic cylinders can be determined by comparing the angle of pressure increase on the reference and on the tested hydraulic cylinder. The angle of pressure increase during the organization of a backup in the drain line can be a diagnostic parameter when determining the technical condition of the hydraulic cylinder, allows you to determine the change in its technical condition.
 CONCLUSIONS: The practical value of the study lies in the fact that with the help of a hardware diagnostic complex used together with the developed diagnostic method, it is possible to establish the technical condition of the hydraulic cylinder. The proposed method of assessing the technical condition allows you to evaluate the resource of hydraulic cylinders, both on the stand and when performing production processes on the machine. This will reduce the downtime of machines, as well as reduce the cost of money for their maintenance and repair.

Risk reduction of tank explosion based on passivation of unusable propellant residues

To reduce the risk of explosion of propellant tanks of expended spacecraft and launch vehicles with liquid rocket engines in orbit, as well as in case of emergency situation, for example, loss of orientation, the Inter-Agency Space Debris Coordination Committee recommends passivation measures, including the discharge of residual liquid propellant and pressurant gas. In ANSYS-Fluent program complex possible initial positions of liquid propellant residues in a spherical tank at its rotation under conditions of low gravitational fields are determined. The values of liquid propellant residues depending on their initial position in the spherical tank at opening of the drain line for discharge of gas–liquid mixture into the ambient space are determined. The concept of formation of two-phase flows of liquid propellant on the example of the spherical tank at tangential entry of compressed gas is offered. The relationship between the number of gas inlet points and the effectiveness of the developed method (expressed as the ratio of the mass of expelled liquid propellant to the mass of gas expended) is demonstrated. For instance, the use of 2 gas inlet points achieves an efficiency of up to 30 %, while employing 3 gas inlet points increases it to 89 %.

Chitinophaga pendula, sp. nov., from an air conditioner condensate drain line.

A Gram-negative, rod-shaped and filamentous bacterium designated MD30BT was isolated from a biofilm hanging in water flowing from an air conditioner condensate drain line in Honolulu, Hawai'i. Based on 1517 nucleotides of the strain's 16S rRNA gene, its nearest neighbours are Chitinophaga rhizosphaerae T16R-86T (96.7 %), Chitinophaga caseinilytica S-52T (96.6 %), Chitinophaga lutea ZY74T (96.6 %), Chitinophaga niabensis JS13-10T (96.6 %) and Chitinophaga ginsengisoli Gsoil 052T (96.5 %). MD30BT cells are non-motile, strictly aerobic, and catalase and oxidase positive. Growth occurs between 10 and 45 °C. Major fatty acids in whole cells of MD30BT are 13-methyl tetradecanoic acid (34.1 %), cis-11-hexadecenoic acid (30.3 %), and 3-hydroxy, 15-methyl hexadecanoic acid (13.3 %). The quinone system contains predominantly menaquinone MK-7. The polar lipid profile contains the major lipids phosphatidylethanolamine, one unidentified lipid lacking a functional group, and two unidentified aminolipids. sym-Homospermidine is the major polyamine. The G+C content of the genome is 47.58 mol%. Based on phenotypic and genotypic differences between MD30BT and extant species in the Chitinophaga, we propose that MD30BT represents a new Chitinophaga species, for which the name Chitinophaga pendula sp. nov. is proposed to accommodate strain MD30BT as the type strain (DSM 112477T=NCTC 14606T).

DC-38GHz Nonuniform Distributed Amplifier Design with Gate and Drain Line Optimization Using 0.1µm GaAs pHEMT Technology

This paper presents an optimized three-cell Nonuniform Distributed Amplifier (NUDA) suitable for optoelectronic drivers in the Q band. This is the first NUDA of Darlington topology designed with the 0.1µm GaAs pHEMT process with a transition frequency fT of 130GHz. Gate microstrip line sections, drain microstrip line sections, and active device sizes were optimized to obtain high gain and large bandwidth from a Monolithic Microwave Integrated Circuit (MMIC) Distributed Amplifier (DA). This paper presents two NUDA designs with different topologies. The first was designed with a three-stage Common Source (CS) topology that enhanced the bandwidth up to 34GHz with a gain greater than 8dB, and the second was designed with two Darlington stages and one CS stage that enhanced the bandwidth up to 38GHz with a gain greater than 8dB. The bandwidth enhancement of NUDA with the Darlington topology was compared and verified with the NUDA of common source topologies.

Reducing the fluid loss in case of depressurization of tractors’ hydraulic drive

BACKGROUND:The operation of hydraulic drives of agricultural machinery is associated with the problem of leakage of fuel and lubricants, leading to contamination of water and soil. The most intense oil spill occurs when high-pressure hoses of hydraulic equipment are destroyed. The existing methods of solving the problem of oil leakage from high-pressure hoses have severe restrictions and high costs of their implementation. One of the effective methods of solving the problem is the use of hydraulic drive protection devices that disconnect the unpressurised section from the pressure source.
 AIMS:To develop an improved protection device an emergency stop device that controls a hydraulic drive with several types of hydraulic motors with a minimum number of device elements.
 MATERIALS AND METHODS:The design of a hydraulic drive emergency stop device (RUF Patent No. 2522013) installed in the hydraulic system of a tractor with single- and double-acting hydraulic cylinders has been developed. The method in use is a morphological analysis of the structure and distinctive features of existing engineering solutions.
 RESULTS:The shutdown unit and the terminal sensor of the emergency stop device compare the value of the hydraulic pump supply with the flow rate in the drain line. At the same time, the device is able to automatically adjust itself to their permissible difference, ensuring that there are no false responses when using double-cavity hydraulic cylinders with one rod. False responses when connecting a single-cavity hydraulic cylinder are prevented by using an additional flow sensor that blocks the shutdown unit. The fluid flow is throttled in the annular gaps between the pistons, sensor and shutdown unit housings; in this case, both pistons are mutually balanced.
 CONCLUSIONS:The proposed solution is aimed to eliminate significant oil throw-out form high-pressure hoses and makes it possible to use a single device for controlling the whole tractor hydraulic system. As a result, the weight and cost of the protection device reduce and the hydraulic drive scheme does not complicate significantly. The developed device does not demand additional power supply from the tractors on-board power circuit, as it operates with use of hydraulic energy. The protection device is applicable to hydraulic cylinders and hydraulic motors of various sizes thanks to ability of self-adjustment to the greatest difference in flow rate.

PROSPECTS FOR THE USE OF WOVEN METAL MESHES AS PHASE SEPARATORS

The constant complication of the tasks that arise before spacecraft during their flight mission puts very high demands on the fuel supply system. First of all, during orbital flight, very often there is a need to restart the main engines, or a constant supply of fuel to the engines of the control system. It is necessary to deliver fuel from tanks to engine combustion chambers in conditions of practical weightlessness. To ensure the ingress of fuel components from the tank into the drain line without gas inclusions, a fuel continuity system is added to the fuel supply system. 
 Among the various systems for ensuring fuel continuity, the most widespread over the past fifty years have been mesh phase separators, the main working element of which is woven metal mesh.
 The paper considers the basic properties of systems of this type, their main design parameters from the point of view of the possibility of their improvement and the possibility of use in future designs of spacecraft. Considerable attention is paid to the shortcomings inherent in systems of this type. Possible ways to eliminate the limitations of the use of mesh phase separators through the development of new engineering design techniques and the use of modern technologies to create analogues of woven metal meshes, which are devoid of their main drawbacks, are considered.

Influence of structural parameters of electro-hydraulic diesel fuel injector on set of diagnostic parameters

Introduction. Malfunctions of the elements of the fuel injection system lead to a deterioration in the performance of diesel engines. The largest proportion of faults that occur during the operation of battery injection systems are electro-hydraulic injectors. For the timely detection of malfunctions, the injectors are diagnosed. The most accurate determination of the technical condition of the injectors can be made using specialized diagnostic stands with their removal from the engine. As a rule, the diagnosis is a conclusion about the general technical condition of the injector. To ensure high quality and reduce the complexity of repairs, it is necessary to use new methods and tools that allow for in-depth diagnostics of injectors with the identification of specific defects. The purpose of the presented work is to identify possible differences in the change in the set of diagnostic parameters when changing individual structural parameters in order to be able to determine specific defects in injectors during their diagnosis.Materials and methods. The hydrodynamic processes occurring in the electro-hydraulic injector during its operation were described by a system of differential equations of the first order. Numerical experiments were carried out to study the influence of changes in structural parameters on diagnostic parameters. The calculations using the software environment for mathematical calculations Mathcad were carried out. The calculations at different combinations of pressures in the fuel accumulator and the duration of the control pulse corresponding to certain engine operating modes were carried out.Results. The paper presents the graphs of the dependences of the cyclic supply, the average fuel consumption in the drain line, the delay in the start of the needle lift, the duration of the needle lift and landing, the duration of the injection and the sensitivity of these diagnostic parameters on the gaps in the interfaces ‘needle guide spray body’, ‘plunger multiplier – sleeve’, from the magnitude of the leakage of the control valve.Discussion and conclusion. As a result of numerical experiments, differences in the change in the set of diagnostic parameters with a change in individual structural parameters were found.

309 Reducing the Catheter Associated Infection Rate Within a Burn Intensive Care Unit

Abstract Introduction Catheter-associated urinary tract infections (CAUTIs) are the most common hospital-onset healthcare-associated infections (HAI) in the United States. HAIs are key quality and safety metrics publicly reported in the acute-care space and linked to hospital reimbursement by the Centers for Medicare and Medicaid Services. CAUTIs, represent approximately 9% of all HAIs, and are associated with increased morbidity, mortality, and cost in intensive care units (ICUs). CAUTIs are thought to impact patient outcomes and healthcare costs significantly. A recent analysis concluded that CAUTIs accounted for only 0.3% of HAI costs in the United States, or approximately $28 million/year. Per patient, CAUTI costs are described in wide ranges from $876 (for inpatient costs to the hospital for additional diagnostic tests and medications) to $10,197 (for inpatient costs to Medicare for ICU patients). The objective of this study was to analyze CAUTI incidences before and after the introduction of a novel urinary catheter with an integrated active drain line clearance system for continuous urine output in a burn intensive care unit. Methods Retrospective cohort study following the implementation of a novel urine output monitoring system with integrated drain line and urine clearance. Data from a 48-month (from January 2015-December 2018) historical control (period 1) were compared to data from a 28-month (from January 2020 to April 2022) post-implementation period (period 2). Pre- and post-implementation CAUTI event incidences were compared. Charts were reviewed to characterize the patients. Results A total of 42 CAUTIs in 2243 patients were identified using the National Health and Safety Network (NHSN) definition during the analyzed period. There were 40 CAUTI events in period 1 and two CAUTIs in period 2. The incidence of CAUTI events pre-implementation was 0.030 (mean of 10 CAUTI events per year) compared to 0.002 (mean of 1 CAUTI event per year) post-implementation of an automatic drain line clearing UO monitoring system showing a significant reduction in CAUTI events (P< 0.01, risk ratio novel vs. gravity bladder catheter 0.071, 95% confidence interval: 0.017-0.294). Conclusions CAUTIs were reduced in the period following the implementation of a novel urinary catheter system with an integrated active drain line and urine clearance in burn patients. Applicability of Research to Practice Implementation of a urinary catheter system with integrated drain line and urine clearance could reduce

Development of simulation models of the hydraulic system of passenger and transport aircraft in normal and failure situations

The paper presents a simulation model of the hydraulic system of an aircraft containing a block supply with a variable flow pump, the discharge line of which is presented in the form of a certain container with liquid, the modulus of elasticity of which is constant, and a hydraulic accumulator is installed in the discharge line a certain capacity and pre-charge pressure, resistance of the discharge and drain lines. The developed simulation model allows failure situations, such as: violation of the internal and external tightness, changing the parameters of the accumulator, reducing the pressure of zero flow due to a change in the stiffness of the springs of the control spool and the servo piston of the regulator, jamming regulator in an intermediate position, etc. In addition, the model allows you to calculate the heat losses associated both with the aircraft flight mode and with changes in the hydrodynamic parameters of the system in regular and failure modes.

55: REDUCING CAUTI EVENTS WITH ACTIVE DRAIN LINE CLEARANCE: A RETROSPECTIVE OBSERVATIONAL STUDY

Introduction: Catheter-associated urinary tract infections (CAUTIs), represent approximately 9% of all hospital-associated infections and are associated with increased morbidity, mortality, and cost in intensive care units (ICUs). We performed a quality improvement study to assess if the use of a bladder catheter with integrated active drain line clearance reduced the rate of catheter-associated urinary tract infections (CAUTIs) in a burn ICU. Methods: We performed an eight-year (2015–2022) retrospective cohort study in a single-center burn ICU with seven beds. CAUTI events were compared from a 48-month period in which gravity bladder catheters had been the standard of care to a 28-month period after the implementation of a novel urinary catheter system. This urinary monitoring system features an active drain line clearance, two one-way valves preventing urinary backflow, and automation of intra-abdominal pressure measurements. Charts were reviewed to characterize the patients. Results: A total of 42 CAUTIs in 2243 patients were identified using the National Health and Safety Network (NHSN) definition during the analyzed period. The incidence of CAUTI events pre-implementation was 0.030 (mean 10 CAUTI events per year) compared to 0.002 (mean 1 CAUTI event per year) post-implementation of an automatic drain line clearing UO monitoring system showing a significant reduction in CAUTI events (P < 0.01, risk ratio Accuryn vs. no gravity bladder catheter 0.071, 95% confidence interval: 0.017-0.294). Median [IQR] urinary catheter dwell time to CAUTI events was 4.5 [2.0, 6.2] pre- and 6.0 [5.5, 6.5] post-novel catheter implementation. Conclusions: A novel urinary catheter system with integrated active drain line clearance reduced the rate of CAUTI after implementation. Active drain line clearance preventing standing urine in the bladder and tubing system and two one-way valves eliminating urine backflow might be favorable features potentially leading to a reduction in CAUTI events compared to gravity urinary catheters.

A Retrospective, Observational Study of Catheter-Associated Urinary Tract Infection Events Post-Implementation of a Novel Urinary Catheter System with Active Drain Line Clearance and Automated Intra-Abdominal Pressure Monitoring.

A quality improvement study to assess catheter-associated urinary tract infection (CAUTI) rate post-implementation of a bladder catheter with integrated active drain line urine clearance and automated intra-abdominal pressure monitoring in a burn intensive care unit (ICU). Eight-year retrospective before and after study (2015-2022). A single American Burn Association-verified Burn Center with 14 inpatient beds. Patients meeting criteria for admission to a Burn Center. Retrospective cohort study following the implementation of a novel urine output monitoring system with integrated drain line and urine clearance. Data from a 48-month (from January 2015-December 2018) historical control (period 1) were compared to data from a 28-month (from January 2020 to April 2022) post-implementation period (period 2). Pre- and post-implementation CAUTI event incidences were compared. Patients were transferred from outside hospitals with gravity bladder. A distinction in the chart between catheter types was impossible. Charts were reviewed to characterize patients with CAUTI events. A total of 42 CAUTIs in 2243 patients were identified using the National Health and Safety Network (NHSN) definition during the analyzed period. There were 40 CAUTI events in period 1 and two CAUTIs in period 2. The incidence of CAUTI events pre-implementation was 0.030 (mean of 10 CAUTI events per year) compared to 0.002 (mean of 1 CAUTI event per year) post-implementation of an automatic drain line clearing UO monitoring system showing a significant reduction in CAUTI events (p &lt; 0.01, risk ratio novel vs. gravity bladder catheter 0.071, 95% confidence interval: 0.017-0.294). CAUTIs were reduced in the period following the implementation of a novel urinary catheter system with an integrated active drain line and urine clearance in burn patients.

Design and analysis of a tunable broadband 180‐degree active coupler with low phase‐error and high‐directivity using staggering technique

This study presents the design and analysis of a 180° tunable non-reciprocal active broadband coupler. To increase the bandwidth, the multi-section impedance transformation technique is utilised. The coupler includes two amplifiers, and three filters (phase-shifters) on the gate (drain) line, referred to as through-path (coupled-path). To achieve an accurate 180° broadband coupler, the staggering technique is utilised for designing the filters. Lumped-element analysis, adopted here for the first time to analyse the active coupler, reveals the impacts of each element on directivity, output phase-shift, and phase-error. The design and post-layout simulation of the coupler are performed in 0.18 µm CMOS technology over the frequency range of 10–20 GHz. An output phase of 180° ± 1.7°, a directivity more than 27 dB, and a return loss better than 10 dB are achieved. The coupling gain is 7.7 dB at the centre frequency, the noise figure is 4.8 dB, and the power consumption is 22 mW. By tuning the bias voltage, the phase imbalance caused by process variations can be compensated. Also, a prototype of the coupler was fabricated and tested on a Rogers substrate for 8–10 GHz band, giving an output phase of 180° ± 2° and a directivity >15 dB.

Thermal Fatigue of Pressurized Water Reactor Coolant System Loop Drain Lines Due to Outflow Activities

Abstract Thermal cycling induced fatigue is widely recognized as one of the major contributors to the damage of nuclear plant piping systems, especially at locations where turbulent mixing of flows with different temperature occurs. Thermal fatigue caused by swirl penetration interaction with normally stagnant water layers has been identified as a mechanism that can lead to cracking in dead-ended branch lines attached to pressurized water reactor (PWR) primary coolant system. Electric Power Research Institute (EPRI) has developed screening methods, derived from extensive testing and analysis, to determine which lines are potentially affected as well as evaluation methods to perform evaluations of this thermal fatigue mechanism for the U.S. PWR plants. However, recent industry operating experience (OE) indicates that the model used to predict thermal fatigue due to swirl penetration is not fully understood. There are limitations with the EPRI generic evaluation. In addition, cumulative effects from other thermal transients, especially those resulted from outflow activities, may also contribute to the failure of reactor coolant system (RCS) branch lines. In this paper, we report direct OE from one of our PWR units where thermal fatigue cracking is observed at the RCS loop drain line close to the welded region of the elbow. A conservative analytical approach that takes into account the influence of thermal stratification, in accordance with ASME section III class 1 piping stress method, is also proposed to evaluate the severity of fatigue damage to the RCS drain line, as a result of various transients, particularly the transients from outflow activities. Finally, recommendations are made for future operation and inspection based on results of the evaluation.

FATIGUE FAILURE IN A LONGITUDINAL WELDED ELBOW OF A PROCESSING VESSEL

A longitudinal welded elbow made of austenitic stainless steel type 316 and used as a drain line on a processing vessel had suffered damage (leakage) after it had only been in operation for a few years. Process fluid that was drained out of the vessel consists of fatty acid containing hydrogen gas at a temperature of 150°C and a pressure of 60 bar(g). Initially, the drain process was carried out only once a year, but recently due to frequent changes in the types of product being made, the frequency of drain process has increased to several times a month. This study aims to determine the type and factors that have caused leakage in the elbow. Metallurgical assessment was carried out by preparing a number of specimens from the leaking elbow. A number of laboratory examinations were performed including visual and macroscopic tests, chemical composition analysis, metallographic examination, hardness tests and scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS) analysis. The results obtained indicate that the leaking elbow has experienced fatigue failure due to cyclic loadings caused by the increasing frequency of the number of drain processes carried out through the elbow. The factor causing fatigue failure at the elbow is likely due to welding defect of imperfect shape that formed on the inner wall of the elbow around the HAZ (heat-affected zone)/fusion boundary, and causing high stress concentrations in that area.