Efficient Test Research Articles

Enhanced biosorption of cadmium ions on immobilized surface-engineered yeast using cadmium-binding peptides

A new type of cadmium (Cd) ion cell surface adsorbent was developed by integrating bacteriophage display peptide library technology with cell surface display technology. Cd2+ chelating resin served as the target molecule in screening experiments, leading to the identification of four Cd2+ −binding peptides. These peptides were introduced into Saccharomyces cerevisiae via the pYD1 plasmid using lithium acetate heat shock transformation. Adsorption efficiency tests indicated that the engineered yeasts adsorbed more Cd2+ than the control strain EBY100 when exposed to the same amount of Cd2+. Among these peptides, sequence 3-containing strain was demonstrated to have the highest Cd2+ adsorption efficiency, being 35% higher than the control strain. Additionally, when this recombinant yeast strain was immobilized using sodium alginate, the adsorption efficiency was increased by 55.7% compared to the control strain.

Measurement of the Weyl potential evolution from the first three years of dark energy survey data.

The Weyl potential, which is the sum of the spatial and temporal distortions of the Universe's geometry, provides a direct way of testing the theory of gravity and the validity of the ΛCDM (Lambda Cold Dark Matter) model. Here we present measurement of the Weyl potential at four redshifts bins using data from the first three years of observations of the Dark Energy Survey. We find that the measured Weyl potential is 2 σ, respectively 2.8 σ, below the ΛCDM predictions in the two lowest redshift bins. We show that these low values of the Weyl potential are at the origin of the tension between Cosmic Microwave Background measurements and weak lensing measurements, regarding the parameter σ8 which quantifies the clustering of matter. Interestingly, we find that the tension remains if no information from the Cosmic Microwave Background is used. Dark Energy Survey data on their own prefer a high value of the primordial fluctuations, together with a slow evolution of the Weyl potential. An important feature of our method is that the measurements of the Weyl potential are model-independent and can therefore be confronted with any theory of gravity, allowing efficient tests of models beyond General Relativity.

Design of a Thermal Performance Test Equipment for a High-Temperature and High-Pressure Heat Exchanger in an Aero-Engine

For next-generation power systems, particularly aero-gas turbine engines, ultra-light and highly efficient heat exchangers are considered key enabling technologies for realizing advanced cycles. Consequently, the development of efficient and accurate aero-engine heat exchanger test equipment is essential to support future gas turbine heat exchanger advancements. This paper presents the development of a high-pressure and high-temperature (HPHT) heat exchanger test facility designed for aero-engine heat exchangers. The maximum temperature and pressure of the test facility were configured to simulate the conditions of the last-stage compressor of a large civil engine, specifically 1000 K and 5.5 MPa. These conditions were achieved using multiple electric heater systems in conjunction with an air compression system consisting of three turbo compressor units and a reciprocating compressor unit. A commissioning test was conducted using a compact tubular heat exchanger, and the results indicate that the test facility operates stably and that the measured data closely align with the predicted performance of the heat exchanger. A commissioning test of the tubular heat exchanger showed a thermal imbalance of 1.02% between the high-pressure (HP) and low-pressure (LP) lines. This level of imbalance is consistent with the ISO standard uncertainty of ±2.3% for heat dissipation. In addition, CFD simulation results indicated an average deviation of approximately 1.4% in the low-pressure outlet temperature. The close alignment between experimental and CFD results confirms the theoretical reliability of the test bench. The HPHT thermal performance test facility will be expected to serve as a critical test bed for evaluating heat exchangers for current and future gas turbine applications.

Optimizing intelligent penetration path planning using reinforcement learning: A focus on valid action masking and sample enhancement

Abstract. As penetration testing is a crucial technique for the rapid evolution of cybersecurity to identify system vulnerabilities, traditional penetration testing methods face the difficulty of large amounts of manual labor and professional knowledge, which makes them difficult to scale. This paper proposes a highly automated and efficient penetration testing approach based on the MASK-SALT-DQN algorithm. MASK-SALT-DQN is a reinforcement learning model that effectively optimizes penetration path planning by valid action masking and sample enhancement. Through valid action masking, the MASK-SALT-DQN model filters out redundant and invalid actions in the solution space, reducing the complexity of the action space and improving the convergence speed and efficiency. In addition, the sample enhancement method increases the frequency of critical exploitation actions and positive rewards in the sparse-reward environment, speeding up the learning process of the agent. Experiments have been conducted on the NASim attack simulation network to demonstrate the advantages of the proposed model over the baseline method. The experimental results show that our model has a significant performance advantage over baseline methods in large networks, and it can be applied to the field of scalable and efficient automated penetration testing.

Efficiency Improvement on Indium Tin Oxide Films for Dye-Sensitized Solar Cell Using Oxygen Plasma by Bias-Magnetron RF Sputtering Process

Dye-sensitized solar cells (DSSCs) are among the most widely studied thin-film solar cells because of their cost-effectiveness, low toxicity, and simple fabrication method. However, there is still much scope for replacing current DSSC materials due to their high cost, low volume, and lack of long-term stability. Accordingly, indium tin oxide (ITO)-nanorod films were fabricated by electron (E)-beam evaporation using the glancing angle deposition method in this study. Then, the ITO-nanorod was treated with oxygen plasma via a bias-magnetron radio-frequency (RF) sputtering process to improve the efficiency of DSSCs under a varying gas flow rate of 20, 40, 60, 80, and 100 sccm. The field emission scanning electron microscopy (FE-SEM) investigation of the ITO film structure revealed that the obtained nanorod structures have slightly different diameters. At the same time, an increase in the oxygen flow rate resulted in a rougher film surface structure. In this, the lower sheet resistance was received because of rougher morphology. When comparing the DSSCs efficiency (η) test results, we found that at a gas flow rate of 100 sccm, the highest efficiency value showed 9.5%. On the other hand, the ITO-nanorod without plasma treatment exhibited the lowest η. Hence, plasma technology can be practically applied to improve the η of DSSC devices. This study will be a prototype of a highly advanced solar cell manufacturing method for the solar cell industry.

Remote Kinematic Analysis for Mobility Scooter Riders Leveraging Edge AI

Current kinematic analysis for patients with upper or lower extremity challenges is usually performed indoors at the clin- ics, which may not always be accessible for all patients. On the other hand, mobility scooter is a popular assistive tool used by people with mobility disabilities. In this study, we introduce a remote kinematic analysis system for mobility scooter riders to use in their local communities. In order to train the human pose estimation model for the kinematic anal- ysis application, we have collected our own mobility scooter riding video dataset which captures riders’ upper-body move- ments. The ground truth data is labeled by the collaborating clinicians. The evaluation results show high system accuracy both in the keypoints prediction and in the downstream kine- matic analysis, compared with the general-purpose pose mod- els. Our efficiency test results on NVIDIA Jetson Orin Nano also validate the feasibility of running the system in real-time on edge devices.

Fixation of Tripotassium Citrate Flame Retardant Using a Sorbitol and Citric Acid Wood-Modification Treatment.

Wood modification has been explored in various ways to enhance dimensional stability and reduce flammability, with a focus on environmentally friendly treatments to meet market demands. This study aimed to investigate the efficacy of new, potential fire-retardant materials. Specifically, the study examined the combination of tripotassium citrate (TPC), a water-soluble and bio-based fire retardant, with sorbitol and citric acid (SorCA), an eco-friendly thermosetting resin previously studied. While TPC is known to control combustion, its application in wood modification has not been thoroughly researched. To assess the fixation and flammability of these fire retardants, tests were conducted on Scots Pine (Pinus sylvestris L.), including chemical analysis, dimensional stability, mechanical properties, flame retardancy, and leaching tests. The combination of SorCA and TPC showed high weight percent gain (WPG) values; however, leaching and anti-swelling efficiency (ASE) tests revealed challenges in fixation stability. The dynamic mechanical properties were reduced, whereas the static strength values were in the same range compared with untreated wood. While TPC exhibited high flame retardancy prior to leaching, its efficacy diminished post-leaching, underscoring challenges in fixation and the need for improved retention strategies. Bunsen burner tests conducted on leached specimens indicated enhanced performance even under severe leaching conditions as per the EN 84:2020 procedure. However, cone calorimetry measurements showed less favorable outcomes, emphasizing the necessity for further investigation into optimizing TPC retention and enhancing treatment efficacy.

Highly Sensitive One-Pot Isothermal Assay Combining Rolling Circle Amplification and CRISPR/Cas12a for Aflatoxin B1 Detection.

Occurrences of mycotoxins in cereals are widespread throughout the world. However, the lack of efficient and ultrasensitive tests has largely impeded the identification of these substances in actual samples. Herein, a novel one-pot isothermal assay that integrates rolling-circle amplification (RCA) and CRISPR/Cas12a to detect aflatoxin B1 (AFB1) is reported. Upon addition of AFB1 to the magnetic bead functionalized with a duplex of the AFB1 aptamer and its complementary DNA (cDNA), the specific recognition of AFB1 by the aptamer causes the release of cDNA to activate the RCA reaction. Subsequently, the RCA amplicon initiates both trans-cleavage and cis-cleavage activities of the endonuclease Cas12a. The synergistic coupling of RCA and CRISPR/Cas12a enables exponential amplification of cDNA, which further promotes CRISPR/Cas12a to nonspecifically cleave the single-stranded DNA reporters with enhanced detection signals. Remarkably, the CRISPR/Cas12a-assisted one-pot isothermal assay can not only achieve ultrasensitive quantitative detection through fluorescence detection, but also achieve visual detection through a lateral flow strip, which improves accessibility to mycotoxin detection in resource-limited regions. The limit of detection was 0.016 and 0.408 ng/mL, respectively. The proposed assay successfully applies in real samples with satisfactory recoveries from 90 to 114%. This study presents a powerful and versatile method for reliable and ultrasensitive detection of mycotoxins in various applications.

Small punch test size reduction to enable high flux irradiation

Screening and qualification of new nuclear materials with superior irradiation resistance requires expensive irradiation exposure and post-irradiation examination before consideration into industrial nuclear structural components. The development of miniaturized test methods is needed for enhanced cost/time efficient testing, while enabling comparative and robust material property estimation in a timely and high throughput manner. The Small Punch Test (SPT) is drawing much interest, especially since the publication of an European standard. Motivated by this standard, a new SP test sample geometry is proposed in order to reduce the material volume to be tested, hences increasing the number of samples that can be introduced in an irradiation rig is proposed. The modified sample diameter has been reduced from 8 to 5.35 mm. The qualification of this new design is described here together with a detailed description of the SPT setup modification as compared to the reference setup of the EN standard. Finite element analyses and a series of experiments have been conducted using both standard and reduced size SP samples to demonstrate that the modified test gives estimates of the basic mechanical properties with the same magnitude of error and validates the modified sample geometry for usage in irradiated material testing.

Interrogating post-transplant donor HLA-specific antibody characteristics and effector functions using clinical bead assays

Single antigen bead (SAB) assays are the most common and sensitive method used to detect and monitor post-transplant donor specific HLA antibodies (DSA). However, a direct comparison across traditional and modified SAB assays to improve routine DSA monitoring using pre-treated IgG sera to eliminate interference has not been performed. We performed a technical comparison of 251 post-transplant DSA from n = 91 serum samples tested neat (pre-treated, undiluted), at a single 1:16 dilution, in the C1q bead assay, and for IgG subclasses (IgG1, IgG2, IgG3, IgG4) with IgG-enriched sera. We found that DSAs that are detectable by 1:16 dilution and/or C1q are associated with higher IgG MFI values and results could be predicted by testing neat sera. DSA detected at 1:16 dilution correlated with >7000 IgG MFI in neat sera and identified DSA that exceeded the SAB linear range for semiquantitative measurements. C1q positive DSA correlated with >15,000 IgG MFI in neat sera. C1q binding correlated most strongly with total IgG MFI (Spearman r = 0.82, p = 0.002) and not specific subclasses, demonstrating that DSA C1q binding capacity in this cohort is driven by HLA-specific IgG concentration. Evaluation of engineered pan-HLA class I-specific human IgG1 and IgG2 subclass monoclonal antibodies by SAB C1q and C3d assays revealed that IgG2 antibodies can bind complement at higher concentrations. The strengths and limitations of modified SAB assays must be considered to optimize efficient testing and accurate clinical interpretation.

The Deployment Mechanism of the E.T.PACK deorbit system: Functional and qualification tests

The Horizon 2020 (H2020) Future Emerging Technologies (FET) OPEN Project E.T.PACK is dedicated to advancing Electrodynamic Tether (EDT) technology by developing a specialized Deorbit Device prototype for end-of-life satellite deorbiting. In collaboration with the E.T.PACK consortium, the University of Padova conducted test campaigns aimed at evaluating the Deployment Mechanism design. This paper offers an overview of these tests, with a specific emphasis on the outcomes derived from tape spool examinations and deployment tests conducted on specific tape lengths. Furthermore, the paper delineates the setup for upcoming end-to-end deployment tests, highlighting the integration of a tape collecting machine to minimize manual intervention. The three-coil spool successfully passed qualification tests under thermal-vacuum conditions, exhibiting no instances of cold-welding. Additionally, shaker tests validated the spool ability to withstand launch conditions without requiring additional containment flanges. Furthermore, the Deployment Mechanism demonstrated its proficiency in smoothly deploying tapes with varying characteristics within the desired velocity range. Moreover, the deployment process, following a specific profile, proceeded seamlessly without any complications. Consistent continuity was maintained throughout the deployment processes, with no instances of jams or disruptions observed. These testing outcomes represent a fundamental step in the preparation and testing of the Engineering Qualification Model of the Deployment Mechanism, instilling confidence that subsequent end-to-end deployment tests will progress smoothly. To this end, a specific upside-down configuration will be implemented, and a recollecting machine was designed and manufactured to facilitate tape gathering, ensuring a streamlined and efficient testing process. A description of the end-to-end deployment test setup, including the recollecting machine, is also provided in this paper.

An empirical test of auction efficiency: evidence from MBS auctions of the Federal Reserve

An empirical test of auction efficiency: evidence from MBS auctions of the Federal Reserve

Long-distance hand tractor controlled by android system in Wetland Field

Modernization of agricultural practices is essential to overcome challenges such as decreasing agricultural labor and decreasing agricultural land in Indonesia. This research examines the development and performance of a hand tractor that is controlled remotely via an Android-based system using the NodeMCU ESP8266 module and a WiFi network. This study focuses on the technical and operational performance of hand tractors in wetlands. Modifications were made to the tractor, by installing three DC motors to control the clutch and gas levers. Tests were carried out on the control system accuracy and response time to assess the system's suitability for field operations. The research results show that the Android system has 100% accuracy in executing all commands given, but the response time decreases as the distance between the Android device and the WiFi module increases, with an average delay reaching 6,8 seconds for a maximum 100 m distance. Field efficiency testing shows that a tractor with Android control has a work efficiency of 70.48% in the plowing process and 75.33% in the harrowing process, lower than with manual control which reaches an efficiency of more than 95%. Despite response delays and reduced efficiency, the system is an important step toward agricultural mechanization, especially in labor-intensive wetlands.

Perancangan Prototype Monitoring dan Akuisi Data Pengujian Noise Trafo Berbasis ESP32

The noise level on the transformer is very important to be considered, because it can cause problems if it does not meet the standards. Excessive noise can violate regulations set by the Ministry of Environment regarding noise limit thresholds, In addition, excessive noise also indicates an indication of a bad transformer construction and will result in the performance of the transformer itself. PT Trafoindo Prima Perkasa, as one of the largest and first transformer manufacturers in Indonesia, tests every transformer produced, including its noise level, The testing is conducted in the Quality Check division. However, testing that is still done manually often causes queue buildup in the production line, along with the increasing demand, especially from PLN, a faster testing process is needed but still meets the set standards. Therefore, a faster, safer, and more efficient testing method is needed to support a continuous production. Based on this requirement, the author designs a prototype monitoring system and data acquisition of ESP32-based transformer noise testing to help speed up and simplify the testing process, so that the finished product can be sent immediately without reducing the quality and standards that have been set.

Evaluation of the penetration capacity of bacteria through layers of different face mask types and wearing conditions.

The aim of this study was to quantify the number of non-airborne bacteria that can passively penetrate the layers of four mask types (surgical mask, community face mask type 1 (CFM1), biocidal CFM1 and CFM2) and to determine the influence of wearing conditions for the surgical type. A mask wearer simulator consisting of a 3D anatomical replica of the upper airway connected to a breathing pump was used. Wearing time, filtration quality of the mask, fit (loose vs. tight) and breathing parameters (tidal volume, respiratory rate) were tested. A Staphylococcus epidermidis inoculum was applied to the inner layer. After the wearing simulation, the layers were separated and the bacteria counted. After four hours, no or only a few bacteria were present in the middle and outer layers. Most remained in the inner layer. Surgical mask and CFM1 retained more bacteria and provided a breeding ground for germs. The biocidal CFM1 rapidly reduced the number in the inner layer. The breathing parameters had no influence, in contrast to fit and wearing time. These results confirm that the standard test for bacterial filtration efficiency, which includes the active penetration of airborne bacteria into aerosol droplets, is the most objective measure of the ability of bacteria to penetrate through the mask layers, as the passive penetration ability of non-airborne bacteria is insignificant.

3D printer fabrication of boron doped Cu-MWCNT/PLA electrodes: Investigation of its efficiency in electrocatalytic hydrogen production

In this study, three-dimensional (3D) electrodes based on MWCNT-Cu/PLA with high electrocatalytic efficiency, large surface area and different amounts of nano‑boron doped MWCNT-Cu/PLA were fabricated using Fused Granular Fabrication (FGF) method with a 3D printer. When FE-SEM images are examined, MWCNT fibers and copper particles are seen more clearly on the surface due to the formation of more dense conductive networks between the conductive carbon fibers trapped in the PLA structure due to the increasing amount of boron. When XRD results are examined, it is observed that the characteristic peaks belonging to the face-centered cubic structure of Cu are dominant and the crystal size increases as MWCNT addition and boron doping increase. When Raman spectra were analyzed to investigate the internal structural changes of MWCNTs, three characteristic bands corresponding to the D band (defect), G band (graphite band) and G' band (D overtone) of MWCNTs were determined and it was observed that the ID/IG ratio decreased with increasing boron doping compared to MWCNT-Cu/PLA electrode. The B1s spectrum of the 3D 0.8B@MWCNT-Cu/PLA electrode confirmed the presence of boron with the peak corresponding to B@C bonds at 191.2 eV. The obtained 3D electrocatalysts were used as cathodes in an electrolysis cell in aqueous solution containing 1 M KOH and their catalytic efficiency in hydrogen evolution reaction (HER) was tested. In order to increase the activity of the 3D electrodes, unlike the literature, they were activated by electrochemical activation process without using organic solvent and HER measurements of the activated electrodes were performed. Before activation, the charge transfer resistance (Rct) value of the Cu/PLA electrode, which was 6219.00 Ω cm−2, decreased to 681.90 Ω cm−2 after 5 % MWCNT doping. It is seen that with boron doping, a greater decrease in Rct value is realized, reaching values of 66.50–74.56 Ω cm−2. The cathodic Tafel slopes show that the Volmer reaction is the rate-determining step for HER and the rate-determining step is the electrochemical adsorption of hydrogen on the metal surface. In addition, energy efficiency tests of the 3D electrodes in HER were also performed and electrochemically active surface areas were determined. Thus, this study has taken an important step toward using 3D electrocatalysts, which are produced with more cost and more flexible designs, unlike previous production techniques, for hydrogen energy production.

Enhancing integration testing efficiency through AI-driven combined structural and textual class coupling metric

Integration testing, a critical and resource-intensive phase in the software development lifecycle, can account for up to a high percentage of the total testing cost. Identifying classes with high coupling is crucial for efficient integration testing, as these classes are more susceptible to the impact of maintenance-related changes. This research introduces a novel metric called <i>combined structural and textual class coupling</i> (CSTCC), which harnesses the power of artificial intelligence (AI) techniques to predict and rank the most critical classes in an object-oriented software system. CSTCC integrates structural coupling metrics with <i>latent semantic indexing</i> (LSI)-based textual coupling, providing a comprehensive measure of class coupling. LSI, an information retrieval technique, analyses the semantic relationships between classes based on their textual content, enabling CSTCC to capture both structural and conceptual dependencies, resulting in a more accurate identification of high-risk classes. The effectiveness of the proposed approach is rigorously evaluated using mutation testing on four Java open-source projects, and the results demonstrate that test cases developed based on CSTCC achieve high mutation scores, indicating their ability to detect a significant percentage of integration faults. By focusing testing efforts on high-coupling classes identified by CSTCC, developers can potentially save time and cost during integration testing. The results demonstrate that test cases developed based on CSTCC achieve high mutation scores, ranging from 98% to 100%, indicating their ability to detect a significant percentage of integration faults. Additionally, the approach results in substantial efficiency gains, with a notable reduction in the number of test cases needed, saving up to 33.3% of the testing effort in some cases. By focusing testing efforts on high-coupling classes identified by CSTCC, developers can potentially save time and cost during integration testing. The CSTCC metric provides a novel and effective approach to prioritize testing resources and improve the efficiency of integration testing in object-oriented software systems.

Computational turf model validation with Clegg Impact Soil Tester experimental impacts on a wide range of synthetic turf constructions

The use of synthetic turf has been increasing in professional sports, where evaluation of novel turf designs for mechanical response, consistency, and athlete playability currently requires time-consuming and complex physical testing on physical turf, and more efficient drop-weight impact testing. A variety of drop tests are used to measure the impact response and surface stiffness of synthetic turf, including the Clegg Impact Soil Tester (CIST). Finite element computational models offer an opportunity to assess new turf designs prior to the construction of physical turfs but require validation for a range of turf constructions. In the present study, 14 different synthetic turf designs with varying infill and fibers were constructed and experimentally evaluated using the CIST device. Peak accelerations and acceleration-versus-time responses were measured. The turf constituent materials were mechanically characterized, FE models of all the turfs were created, and the CIST tests were simulated. The peak acceleration from the simulation followed the experimental trend for the wide range of turf designs, with an average difference of 9.7%. When considering conventional turf constructions, the average difference in peak acceleration was 8.8%, indicating the models provided a good prediction of turf impact response and can be used to assess new turf designs virtually, potentially reducing design times and physical test requirements.

Luck in high-stakes firm lottery allocation: A natural experimental test of Coasean efficiency and invariance in a prominent sport finance setting

The NBA Player-Draft is a prominent sport-finance setting, with large rents allocated to teams. Several properties make this setting ideal to study the Coase Theorem in a cartelized-firm setting, where the Theorem’s empirical credence and overall relevance to real-world financial settings continue to be questioned. Identification of a high-stakes, salient setting featuring exogenously-assigned property rights has proven elusive. While several studies examine the Coasean implications of professional sports league drafts, we find draft rights are endogenously-assigned. We cultivate, verify, specify, and examine an exogenously-assigned draft right—draft lottery luck—for the 2000–2015 NBA Drafts. Given its revealed exogeneity, we utilize variation in annual lottery luck as a natural experiment to study the Coase Theorem and find robust evidence for “instantaneous” Coasean efficiency (as in efficiency of the efficient market hypothesis) but also evidence that Coasean invariance, with respect to firm profits, fails. Secondary analysis reveals respective mechanisms and sport-financial implications.

Effective Determination of Diosmin Using Nitrogen Doped Carbon Dots as Probe Based on Internal Filtering Effect.

The establishment of a convenient and efficient testing method is crucial and needed for the monitoring of diosmin. In this study, nitrogen doped carbon dots (N-CDs) with the particle size distribution of 2.5-5.7nm and the average diameter of 4.1nm were successfully synthesized using a simple strategy. N-CDs exhibited excellent and stable fluorescence performance with the quantum yield of 22.33%. Correspondingly, a fluorescence analytical method was developed for diosmin determination using N-CDs as probe. UV-vis absorbance spectroscopy and the evaluation of internal filtering parameters verified that the mechanism causing the quenching of N-CDs was an internal filtering effect (IFE). The concentration of diosmin can be directly evaluated based on the quenched fluorescence intensities. After optimizing experimental conditions, it was found that the fluorescence quenching efficiency ((F0-F)/F0) of N-CDs exhibited a good linear relationship with the concentration of diosmin (CDiosmin) in the range of 3.0-50µg/mL. The limit of detection (LOD) was 0.86µg/mL based on 3σ/slope (n = 13). This method was successfully applied to accurately determine the content of diosmin in diosmin tablets and human plasma samples with good reproducibility. It stands out for its simplicity, speed, and acceptable determination performance.