Performance Verification Test Research Articles

Research on seedling sowing method based on high voltage electrostatic characteristics

In response to the difficult problem of high leakage rate and low seed pick-up rate of traditional air-suction seed dischargers. This study proposes a new high-voltage electrostatic vegetable seedling sowing method and system based on phase sucking of opposite charges and repulsive seeding of same charges. This method does away with small orifices and long conductance suction holes. It can solve the technical bottleneck of the traditional air-suction seed rower at the source, which causes a decrease in seed rowing accuracy due to clogging of the suction holes when facing irregular small vegetable seeds that are not pelleted. Combining high voltage electrostatic polarisation for seed vigour with precision seeding technology. Improving seed vigour and crop yield while precision sowing. Modelling the mechanics of adsorption seeding and repulsive seeding systems. Identify the main factors affecting electrostatic adsorption and phase repulsion forces and their interrelationships; Analysis of the decay mechanism of the electrostatic adsorption force upon repeated action. Proposing measures for the rapid restoration of the original equilibrium state of the dielectric insulation by reverse electric field polarization; Analysis of the migration pattern of electric particles during polarisation. Solving the equations for seed dynamics during sowing; At positive input voltages of 16 kV and negative input voltages of 0, 4, 8, 12, 16 and 20 kV. Separate dielectric insulation layer adsorption seeding tests. The test results show that: The reverse electric field polarisation of the dielectric insulating layer is effective in containing the electrostatic adsorption decay. The best containment was achieved at a positive input voltage of 16 kV and a negative input voltage of 16 kV; Seeding performance verification tests at a positive input voltage of 16 kV and a negative input voltage of 16 kV. The test results show that: The sowing conformity index was 90.25 %, the reseeding index 3.40 % and the missed sowing index 6.35 %. In the evaluation of applied research, the multi-objective optimization design with the objective function of maximum seed discharge qualification index, minimum leakage index and replanting index, the optimal parameter combinations of the test factors can be obtained as follows: the size of the type hole is 5.977 mm, and the output voltage of the positive high-voltage electrostatic generator is 16.423 kV, and at this time, the seeding machine's seed discharge qualification index is 90.78 %, the replanting index is 3.05 %, and the leakage index is 6.17 %. To verify the reliability of the optimal design of structural parameters, the seeding performance verification test is carried out, which can be obtained: the qualified index of row seeding is 90.54 %, the index of reseeding is 2.86 %, and the index of leakage is 6.60 %, which meets the technical requirements of precision seeding. The research not only provides a reference for the development of precision sowing machinery and equipment for irregular small-grain vegetable seeds. It also provides an academic reference for the research of quantitative adsorption and rapid separation methods and theories for irregular small particle materials.

Application of Salicylic Acid Tablets in the Performance Verification Test for the Flow-Through Cell Apparatus

Application of Salicylic Acid Tablets in the Performance Verification Test for the Flow-Through Cell Apparatus

Uncertainty analysis of UAM TMI-1 benchmark by STREAM/RAST-K

This study rigorously examined uncertainty in the TMI-1 benchmark within the Uncertainty Analysis in Modeling (UAM) benchmark suite using the STREAM/RAST-K two-step method. It presents two pivotal advancements in computational techniques: (1) Development of an uncertainty quantification (UQ) module and a specialized library for the pin-based pointwise energy slowing-down method (PSM), and (2) Application of Principal Component Analysis (PCA) for UQ. To evaluate the new computational framework, we conducted verification tests using SCALE 6.2.2. Results demonstrated that STREAM's performance closely matched SCALE 6.2.2, with a negligible uncertainty discrepancy of ±0.0078% in TMI-1 pin cell calculations. To assess the reliability of the PSM covariance library, we performed verification tests, comparing calculations with Calvik's two-term rational approximation (EQ 2-term) covariance library. These calculations included both pin-based and fuel assembly (FA-wise) computations, encompassing hot zero-power and hot full-power operational conditions. The uncertainties calculated using both the EQ 2-term and PSM resonance treatments were consistent, showing a deviation within ±0.054%. Additionally, the data compression process yielded compression ratios of 88.210% and 92.926% for on-the-fly and data-saving approaches, respectively, in TMI fuel assembly calculations. In summary, this study provides a comprehensive explanation of the PCA process used for UQ calculations and offers valuable insights into the robustness and reliability of newly developed computational methods, supported by rigorous verification tests.

Breakdown characteristics and influencing factors of live 500 kV insulators sprayed by extinguishing agents using helicopters

Regarding the problem that helicopters cannot spray live transmission conductors and wildfires directly under an insulator, we built a full-scale 500 kV insulator flashover test platform to simulate high-altitude helicopters spraying fire extinguishing agents. The chemical formulation, spray intensity, and fragmentation method of the fire extinguishing agents were varied. We simulated the breakdown characteristics of insulators when helicopters spray fire extinguishing agents, revealing the mechanism of high-altitude live fire extinguishment for high-spray-intensity and high-conductivity agents. Furthermore, an insulation performance verification test of a helicopter spraying live equipment at different flight speeds and altitudes was carried out, and the behavior of the fire extinguishing agents was divided into a five-zone diffusion law consisting of the (1) water column, (2) continuous water block, (3) semi-continuous water body, (4) large droplet particles, and (5) small droplet particles. We propose a spraying live transmission line method in which the helicopter flight height and speed jointly control the particle size of the fire extinguishing agent. When the particle size of the fire extinguishing agent at the terminal is controlled to 560–4000 μm, the insulation performance of the fire extinguishing agent can be effectively improved. During high-incidence periods of wildfires, such as the Spring Festival and Qingming Festival in 2023, on-site firefighting on the Hunan power grid was performed using helicopters to spray fire extinguishing agents from top to bottom through live transmission conductors to extinguish wildfire disasters directly below the transmission conductors. Neither transmission line flashovers nor power outages occurred when the fires were extinguished.

Avoid equipment graveyards: rigorous process to improve identification and procurement of effective, affordable, and usable newborn devices in low-resource hospital settings

BackgroundMillions of newborns die annually from preventable causes, with the highest rates occurring in Africa. Reducing neonatal mortality requires investment to scale hospital care, which includes providing hospitals with appropriate technology to care for small and sick newborns. Expensive medical devices designed for high-resource settings often fail to withstand conditions in low-resource hospitals, including humidity, dust, frequent user turnover, complex maintenance, lack of stable power, or difficulty sourcing expensive consumables. Rigorous evaluation protocols are needed to identify effective, affordable, rugged, and easy-to-use medical devices appropriate for quality hospital-based newborn care in low-resource hospitals.MethodsWe developed an evidence-based technology review process to identify medical devices suitable for small and sick newborn care in low-resource hospitals. The eight-step process consists of: identifying devices needed for effective newborn care; defining Target Product Profiles (TPPs); identifying commercially-available products that may meet TPPs; conducting desk research to evaluate technologies against TPPs; performing technical performance verification testing under laboratory conditions; verifying technical performance after exposure to heat, humidity, dust, and power loss; performing usability evaluations with nurses, and qualifying devices that pass all steps. Devices were purchased, installed, and monitored in newborn wards across Kenya, Malawi, Nigeria, and Tanzania.ResultsOf 271 devices considered, only 45 (16.6%) met corresponding TPPs based on desk research. Thirty-nine were purchased and evaluated in the laboratory; five (12.8%) failed to meet TPPs. Thirty-four products passing laboratory evaluation underwent short-term environmental testing; only one (2.9%) device failed. Thirty-seven products underwent usability testing with 127 clinicians; surprisingly, 14 (37.8%) failed to meet TPPs. Twenty-three products passed all evaluations, and 2457 devices were installed across 65 newborn wards in Kenya, Malawi, Nigeria, and Tanzania. Continuous device monitoring reported minimal device failures, with failed devices typically returned to service within two days, resulting in an average uptime (service days divided by days installed) of 99%.ConclusionAn evidence-based device selection process can improve procurement of effective, affordable, rugged, usable newborn care devices for low-resource hospitals, and feedback to manufacturers can improve device quality. Similar processes could be adapted beyond newborn care to identify medical devices suitable for implementation in any low-resource setting.

Design and Test of a Comb-Brush-Type Honeysuckle-Picking Device

In response to the issues of high honeysuckle-picking costs and low efficiency in honeysuckle picking, this study has devised a comb-brush-type picking device, considering the unique characteristics of honeysuckle plants. We elucidated the device’s structure and operational principles and designed critical components within the picking mechanism. Subsequently, through theoretical analysis, we identified the primary factors influencing the device’s operational performance. We then used the honeysuckle picking rates, honeysuckle breakage rates, and impurity rates as assessment metrics. Utilizing a one-factor test, we determined the permissible ranges for each factor. Employing the response surface methodology, we analyzed the interactions among these factors and conducted model parameter optimization. This optimization identified the optimal parameter combination: a forward speed of 3.99 km/h, a driving shaft speed of 316.53 rpm, and a picking teeth length of 70 mm. Finally, we performed verification tests using these optimized parameters. The results demonstrated that the maximum relative error between test verification values and model-optimized predictions was 4.86%. This outcome confirms that the comb-brush-type honeysuckle-picking device can meet the operational requirements of mechanized harvesting and offers valuable insights for developing harvesting devices for vine plants.

The STATiX pipeline for the detection of X-ray transients in three dimensions

ABSTRACT The recent serendipitous discovery of a new population of short duration X-ray transients, thought to be associated with collisions of compact objects or stellar explosions in distant galaxies, has motivated efforts to build up statistical samples by mining X-ray telescope archives. Most searches to date, however, do not fully exploit recent developments in the signal and imaging processing research domains to optimize searches for short X-ray flashes. This paper addresses this issue by presenting a new source detection pipeline, STATiX (Space and Time Algorithm for Transients in X-rays), which directly operates on three-dimensional X-ray data cubes consisting of two spatial and one temporal dimension. The algorithm leverages wavelet transforms and the principles of sparsity to denoise X-ray observations and then detect source candidates on the denoised data cubes. The light curves of the detected sources are then characterized using the Bayesian blocks algorithm to identify flaring periods. We describe the implementation of STATiX in the case of XMM–Newton data, present extensive validation and performance verification tests based on simulations and also apply the pipeline to a small subset of seven XMM–Newton observations, which are known to contain transients sources. In addition to known flares in the selected fields, we report a previously unknown short duration transient found by our algorithm that is likely associated with a flaring Galactic star. This discovery demonstrates the potential of applying STATiX to the full XMM–Newton archive.

Analysis of fatigue fracture incident of centrifugal compressor blades in a small turbojet engine

In this study, performance verification tests were conducted on a small turbojet engine, during which a failure occurred at the root of the centrifugal compressor blades, which are made of aluminum alloy. A detailed disassembly and inspection was carried out to reveal the reason of the failure. It was found that the failure of one blade at the root led to jamming of other blades. Then the jammed blades experience sever rubbing and contact with the intake duct. Experimental measurements of material properties and a retrospective examination of the manufacturing process revealed that the yield strength of the material was lower than the design value, and the fillet radius at the blade root was smaller than specifications. The root cause of the fatigue failure of the compressor blades in this incident was attributed to substandard machining quality and material properties, which leads to crack initiation and fatigue propagation until failure occurred. The experience of identifying the root cause would provide engineering guidance for other small turbojet engines.

Design and Analysis of a Pneumatic Automatic Compensation System for Miss-Seeding Based on Speed Synchronization

In order to solve the problems of poor seed filling performance and the low compensation accuracy of large- and medium-sized missed seeding compensation devices under medium- to high-speed conditions, a pneumatic missed seeding automatic compensation system based on speed synchronization was designed. The key structure and parameters in terms of the seed metering plate and seed feeding arm were determined by theoretical analysis. A universal compensation control system for single-seed missed seeding and continuous missed seeding was designed. With regards to exploring the working performance, some relevant bench tests were carried out, with Zhengdan-958 corn seeds and Zhonghuang-37 soybean seeds serving as the test objects. First of all, a single-factor test was conducted to determine the optimal level ranges of the factors that influence seed filling performance, such as suction hole diameter, seed stirring bar thickness, and negative pressure. The test indicators were qualified seed filling rate, multiple seed filling rate, and missed seed filling rate. Next, the Box–Behnken design test was executed to explore to the influence law of each test indicator on corn seed filling performance. Then, the parameter optimization module was applied to achieve the best combination of operating parameters for the test factors. The optimal combination of parameters was a suction hole diameter of 5.3 mm, seed stirring bar thickness of 2.9 mm, and negative pressure of 4.1 kPa. Based on the optimal combination, a verification test of corn seed filling performance was performed, and the corresponding evaluation indexes were a qualified seed filling rate of 95.46%, multiple seed filling rate of 2.47%, and missed seed filling rate of 2.07%. Lastly, a seed feeding performance verification test was employed with the seeding speed as the impact factor to verify the compensation accuracy of single-seed missed seeding and continuous missed seeding compensation. The results of the verification test indicate that, for corn seeds, when the seeding speed falls within the range of 8 to 12 km/h, the effective single-seed feeding rate exceeds 88%, the average single-seed feeding time is less than 0.18 s, the qualified seed feeding rate is higher than 90%, the multiple seed feeding rate is lower than 3%, and the missed seed feeding rate is below 7%. For soybean seeds, the effective single-seed feeding rate is higher than 85%, the average single-seed feeding time is less than 0.17 s, the qualified seed feeding rate exceeds 86%, the multiple seed feeding rate is less than 4%, and the missed seed feeding rate is below 10%. This system meets the agronomic requirements for the automatic compensation of missed seeding with respect to large- and medium-sized precision seeders, which could help to improve the operational performance of seeding machines.

The Development of a New Thermoplastic Elastomer (TPE)-Modified Asphalt

The use of (recycled) plastics and (waste) vulcanized rubber powder is the main polymer of raw materials, and composite organic additives are selected to fully combine with asphalt components. The physical and chemical reactions between different components are completed in dynamic mixing, establishing a morphology structure similar to thermoplastic elastomers (TPEs), and a thermoplastic highly asphaltized alloy material. TPE-modified asphalt not only significantly improves the high-temperature stability of the base asphalt, but also has the social and economic value of rational utilization of resources and turning waste into treasure. There are very few studies on the preparation of modified high-viscosity asphalt formulations using rubber and plastic as modifiers. In this study, rubber, plastic, and plasticizers were added to the base asphalt, and the TPE modifier formulations were developed through the research of new TPE modifier series and functional formulations, preparation process, and its modified asphalt properties. Meanwhile, the preparation method of the rubber–plastic alloy modifier was determined. The performance of the TPE-modified asphalt was verified through performance verification tests to evaluate the modification effect of the modifier on the base asphalt. The test results showed that the penetration, softening point, ductility, and viscosity indexes of the TPE-modified asphalt developed through the proposed formulation, and it met the specification requirements for high-viscosity modified asphalt. Rubber and plastic modifiers significantly improved the high-temperature stability of the base asphalt. In addition, the rubber–plastic modifier had a significant tackifying effect, with a dynamic viscosity of 60 °C and a Brinell rotational viscosity much greater than asphalt and rubber asphalt. The microscopic mechanism of the newly developed TPE-modified asphalt was analyzed by fluorescence microanalysis. The results showed that the rubber–plastic modifier fully swelled in the asphalt and was uniformly dispersed in the asphalt as a floc. The network structure of activated waste rubber powder-modified asphalt was more uniform and dense, resulting in good performance of the modified asphalt, and stable storage of modified asphalt was obtained. Through appropriate formulation, the comprehensive performance of the TPE-modified asphalt obtained met the requirements of pavement application and construction, providing a good theoretical basis for promoting TPE-modified asphalt.

Fatigue test fracture analysis of aircraft blade connecting pin

During the fatigue performance verification test of the blade simulator, a fixed connecting pin on which the splint was installed broke. In this paper, the fracture properties of the connecting pin were determined by observing the macro/micro morphology of the connecting pin and the fracture surface of the coating. By analyzing the elements, structure, hardness and relative ratio of the body and coating, the differences between the connecting pins of different blades were studied, and the fracture causes of the connecting pins were comprehensively analyzed. Based on the above experiments, the influence of coating quality on fatigue cracking is analyzed, and the improvement scheme of connecting pin is put forward.

On-Line Detection Method and Device for Moisture Content Measurement of Bales in a Square Baler

Aiming to address the problems of low detection accuracy and poor stability due to the weak anti-interference ability of the bridge circuit and operational amplifier circuit, and the influence on the capacitance of the bulk density and temperature of the straw bale, an on-line detection device for the moisture content of straw bales in a square baler was developed based on the capacitance method. The device integrates a capacitance sensor, pressure sensor, and temperature sensor. The optimal structure size of the capacitor plate was determined through the simulation test of the capacitor sensor plate structure. A moisture content monitoring system based on the MATLAB language is built, and the moisture content detection model was constructed based on the backpropagation neural network (BPNN) algorithm. Finally, a test bench for a square baling machine was designed, and a performance verification test of the moisture content detection device was carried out. The simulation results of the capacitor plate show that when the length, width, and spacing of the capacitor plate are 148.6, 47.7, and 5.1 mm, respectively, the detection sensitivity of the capacitor plate is the highest. The modeling results show that the R2, RMSE, and RPD of the BPNN model are 0.986, 0.008998, and 5.99, respectively, with solid data fitting ability and high prediction accuracy. The bench test results show that for the samples having moisture content between 13.1 and 28.04%, the coefficient of determination R2 of the fitting curve between the predicted value of moisture content and the actual value is 0.949. The relative error range of the predicted value of moisture content is −6.51–8.66%, and the absolute error range is −1.63–1.72%. The on-line detection device for moisture content of straw bales has good accuracy and stability.

Experimental study on performance verification test of optimized film cooling holes in a linear cascade

• The fan-shaped hole on the flat model is optimized with the RBNN surrogate model and CS optimization algorithm. • The film cooling performance of the optimized fan-shaped hole is verified in a linear cascade. • The optimized fan-shaped hole can improve the film cooling performance and suppress the phenomenon of coolant jet off from surface. Film cooling is an essential external cooling technology in turbomachinery. In this paper, firstly, an original hole on the flat model was optimized with the radial basis neural networks surrogate model and cuckoo search optimization algorithm. The optimization variables are the laid-back angle, half of the expend angle and the cylindrical length. Subsequently, the optimized holes are arranged in a linear cascade for experimental verification. To verify the optimization method, the cooling performance of original and optimized holes on the linear cascade was investigated under different blowing ratios and positions. Compared with the original hole, the optimized one has various expand angle, laid-back angle and proportion of the expanded section. The experimental tests were conducted in a linear cascade which has three turbine blades. The mainstream flow parameters were set with Reynolds number (inlet) values of 4.3 × 10 5 and Mach number (outlet) values of 0.4. The adiabatic temperature near the profile was measured by an infrared camera. As the results of the SS3 row presented, on the surface of the film hole downstream where x/d is within 5, the film cooling effectiveness of the optimized hole is more significant than original hole. In the downstream of hole rows where x/d is between 5 and 40, the η of optimized hole is lower than original hole, since the optimized hole has a larger expand angle than the original hole. At the PS4 row, the η of optimized hole is higher than original hole at any M .

A Comparative Study of Explicit and Stable Time Integration Schemes for Heat Conduction in an Insulated Wall

Calculating heat transfer in building components is an important and nontrivial task. Thus, in this work, we extensively examined 13 numerical methods to solve the linear heat conduction equation in building walls. Eight of the used methods are recently invented explicit algorithms which are unconditionally stable. First, we performed verification tests in a 2D case by comparing them to analytical solutions, using equidistant and non-equidistant grids. Then we tested them on real-life applications in the case of one-layer (brick) and two-layer (brick and insulator) walls to determine how the errors depend on the real properties of the materials, the mesh type, and the time step size. We applied space-dependent boundary conditions on the brick side and time-dependent boundary conditions on the insulation side. The results show that the best algorithm is usually the original odd-even hopscotch method for uniform cases and the leapfrog-hopscotch algorithm for non-uniform cases.

New type of high-strength flexible cover plate to prevent engineering failure in oil and gas pipeline engineering

Reinforced concrete cover plates are the main engineering protection measure for oil and gas pipelines in densely populated areas with high consequences. However, they have disadvantages such as high cost, difficult construction, long construction time, and inability to promptly and effectively warn mechanical operators. On-site excavation tests were carried out in order to verify the warning performance and impact resistance of a high-strength flexible cover. In the warning performance verification test, when an excavator hits the high-strength flexible cover plate set above the oil and gas pipeline during operation, the excavator driver should immediately receive obvious warnings that there are obstacles underground and that the digging should be stopped immediately. In the impact resistance verification test, the high-strength flexible cover plate should provide sufficient mechanical protection to withstand the penetration of the cover plate by an excavator weighing at least 30 tons and to avoid the damage of a pipeline below. At the same time, it is necessary to determine the one-time impact depth of the excavator bucket by designing the working condition under which the high-strength flexible cover is not buried in the soil, and is affected by the vertical action of the excavator bucket. This depth value serves as an important data support for the minimum safety distance between the high-strength flexible cover and the oil and gas pipeline. This paper proposes the application of a new type of the high-strength flexible cover plates instead of reinforced concrete cover plates above pipelines. Field tests verified the important role of the high-strength flexible cover plates in the protection of oil and gas pipelines. When long-distance oil and gas pipelines pass through densely populated high-consequence areas, they can replace traditional reinforced concrete cover plates to achieve an effective pipeline protection. At the same time, they have a simple structure, their construction is convenient, they are reliable and stable, and economical and rational. By using the high-strength flexible cover plates, savings that exceed 70% of the project investment may be achieved.

Composition optimization and characterization of combustible cartridge cases with polyvinyl acetate (PVAc) as a binder

Combustible cartridge case samples composed of nitrocellulose (NC), polyvinyl acetate (PVAc), kraft cellulose (KC), dibutyl phthalate (DBP) and diphenylamine (DPA) were prepared to study their structures and chemical and mechanical properties. Taguchi’s experimental design method was used to design the experimental formulations. First, simultaneous thermogravimetry-differential scanning calorimetry (STA TG-DSC), scanning electron microscopy (SEM), Brunauer–Emmett–Teller analyser (BET), bomb calorimeter (BC), vacuum stability tester (VST) and a tensile testing machine (TTM) were employed to analyse the thermochemical characteristics, structure, explosion heat, chemical stability and compatibility, and mechanical strength of all formulated samples. Based on the analysis results, the weight loss of the combustible cartridge case sample obtained by the TG experiment was chosen as the quality characteristic. The results of the Taguchi analysis indicated that the optimal parameter combination was an NC/KC weight ratio of 80:20, an NC/PVAc weight ratio of 85:15, an additional DPB of 3.5 wt.% and a density of 1.25 g/cm3. The results of the chemical stability and compatibility test, explosion heat test and mechanical strength test show that the test samples prepared with the optimal parameter combination can meet the requirements of combustible cartridge cases. Furthermore, the combustion performance of the combustible cartridge case sample prepared with the optimal formula was measured by a high-temperature combustion furnace (HTCF) and burning rate measurement device (BRM). The experimental results indicated that the autoignition temperature and ash content were 231 °C and 0.28%, respectively. In addition, the burning rate increased with increasing combustion chamber pressure but was lower than that of ordinary gun propellants at the same pressure. These combustion characteristics can meet the quality requirement of combustible cartridge cases. Finally, an actual combustible cartridge case was prepared and verified. The result of the performance verification test indicated that the average ash content was 0.30%, which was similar to that of the previous test samples and met the quality requirement.

Finding a reliable assay for soluble neprilysin

BackgroundLack of validation and standardization of research-use-only (RUO) immunoassays brings with it inherent threats to authenticity and functional quality. Poor correlation between different commercial neprilysin RUO immunoassays is concerning and discordant findings need to be resolved. We seek to identify and validate reliable neprilysin immunoassays to strengthen the scientific rigor and reproducibility of neprilysin-related investigation and of biomarker research in general. MethodsSoluble neprilysin (sNEP) concentrations were determined in cohorts (n = 532) from Spain (Cohort 1), New Zealand (NZ, Cohort 2) and Singapore (Cohort 3), using commercial kits from six vendors. Apparent sNEP concentrations were correlated between different assays and with plasma neprilysin activity. Assay reliability was further validated by performance verification, MS analysis and cross-reactivity tests. ResultssNEP in Cohorts 1 and 2 measured concurrently in Spain and NZ showed significant inter-laboratory correlation only for the Aviscera Bioscience sNEP ELISA SK00724-01. Neprilysin concentrations obtained with the R&D systems and SK00724-01 ELISAs correlated with each other but not with neprilysin activity. In Cohort 3, sNEP concentrations from the Perkin Elmer AlphaLISA and Biotechne ELLA assays agreed (r = 0.89) and both correlated with neprilysin activity (r = 0.87, 0.77 respectively). MS analysis detected authentic neprilysin in the AlphaLISA kit calibrator and in antibody pull-down material from human plasma. The AlphaLISA assay performed within acceptable limits (spike and recovery, dilutional linearity, inter- and intra-assay CV) and showed no cross-reactivity against neprilysin substrates and closely-related analogues. ConclusionAlphaLISA and ELLA assays provide reliable measures of sNEP concentrations. Reliability of other commercial neprilysin assays remains in question.

Advances in the metrological traceability and performance of X-ray computed tomography

X-ray computed tomography (XCT) is increasingly being used for evaluating quality and conformance of complex products, including assemblies and additively manufactured parts. The metrological performance and traceability of XCT nevertheless remains an important research area that is reviewed in this paper. The error sources influencing XCT measurement results are discussed, along with related qualification, calibration and optimization procedures. Moreover, progress on performance verification testing and on the determination of task-specific measurement uncertainty is covered. Results of interlaboratory comparisons are summarized and performance in various dimensional measurement fields is illustrated. Conclusions and an outlook for future research activities are also provided.

Experimental Study on Performance Verification Test of Optimized Film Cooling Holes in a Linear Cascade

Experimental Study on Performance Verification Test of Optimized Film Cooling Holes in a Linear Cascade

Analysis of Long-Term Prestress Loss in Prestressed Concrete (PC) Structures Using Fiber Bragg Grating (FBG) Sensor-Embedded PC Strands

This study aims to develop a prestressed concrete steel (PC) strand with an embedded optical Fiber Bragg Grating (FBG) sensor, which has been developed by the Korea Institute of Civil Engineering and Building Technology since 2013. This new strand is manufactured by replacing the steel core of the normal PC strand with a carbon-fiber-reinforced polymer (CFRP) rod with excellent tensile strength and durability. Because this new strand is manufactured using the pultrusion method, which is a composite material manufacturing process, with an optical fiber sensor embedded in the inner center of the CFRP Rod, it ensures full composite action as well as proper function of the sensor. In this study, a creep test for maintaining a constant load and a relaxation test for maintaining a constant displacement were performed on the proposed sensor-type PC strand. Each of the two tests was conducted for more than 1000 h, and the long-term performance verification of the sensor-type PC strand was only completed by comparing the performance with that of a normal PC strand. The test specimens were fabricated by applying an optical fiber sensor-embedded PC strand, which had undergone long-term performance verification tests, to a reinforced concrete beam. Depending on whether grout was injected in the duct, the specimens were classified into composite and non-composite specimens. A hydraulic jack was used to prestress the fabricated beam specimens, and the long-term change in the prestress force was observed for more than 1600 days using the embedded optical fiber sensor. The experimental results were compared with the analytical results to determine the long-term prestress loss obtained through finite-element analysis based on various international standards.