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Traditionally, the H2S partial pressure (PH2S) of the gas/hydrocarbon phase has been used as the primary sour severity metric for material qualification and selection under ANSI/AMPP (NACE) MR0175/ISO 15156 guidelines. While the PH2S is appropriate for characterizing low total pressure systems, the strict, or ideal, Henry’s Law approach leads to over estimation of the dissolved H2S concentration (CH2S) for high-pressure, high-temperature (HPHT) wells by up to approximately 20 times at 70°F (21°C). Alternatively, the Ensemble Henry’s Law equation corrects for the non-ideal phase behavior of H2S at HPHT conditions and avoids over-estimation of CH2S. Given the industry’s reliance on using thermodynamic models to evaluate sour HPHT systems, an investigation was initiated to determine the accuracy of these model calculations. An empirical program was undertaken to verify CH2S predictions for the H2S-N2-H2O system. Multiple 2.7 L C-276 lined autoclaves were charged with a fixed inventory of H2S in N2 at multiple total pressure steps, with increasing N2 pressure, between 30 psig and 20,000 psig (3 bar and 1,380 bar) at 70±5°F (21±3°C). Per total pressure step, H2S levels in both the headspace gas and liquid phases were measured using common H2S sampling techniques (H2S-specific colorimetric tubes and iodometric titration, respectively), following ANSI/NACE TM0177-2016 guidelines. The results were used to calculate total pressure corrected (apparent) H2S solubility coefficients (AkH2S). Very good agreement was observed between empirically and computationally derived AkH2S values.

In this work, the design qualification testing, evaluation and test methods of gas generator using double base (DB) propellant having square flake shape is explained for an improvised explosive devices (IEDs) applications. Various kinds of the gas generators are used to save life of an aeronaut in the fastest way from the disable fighter aircraft. Due to their ruggedised design, compactness, safe transportation, repeatability in performance and quick operation, the gas generator are used. The gas generator is designed and developed keeping functional, mechanical and structural requirements in mind. The gas generators are subjected to the various qualification tests, electrical characterisation followed by closed vessel (CV) firings at hot and cold temperatures. The gas generators after the successful qualification tests are validated through the ground trials i.e. dynamic firing of disruptor during the development phase. The damage caused due to impact of the projectile is assessed in terms of crater as acceptance criteria at stand-off distance of 0.5 m and 1m. The gas generator discussed in this research article is used to disrupt the suspected IEDs by creating a high-speed jet using water-jet disruptor. In conclusion, after successful qualification testing, the gas generator for IEDs application meets all the specifications as per user’s requirements.

Knowledge about the space radiation environment is crucial for the design and selection of materials and components used for space applications. This environment is characterized not only by the Sun’s electromagnetic radiation but also by charged particles categorized into solar wind, solar energetic particles (SEP) and galactic cosmic rays (GCR). Especially for material engineering and qualification testing, differential and integral spectra for particle energies ranging from keVs to GeVs are required. Up to now, a wide variety of models is available, whereas it is difficult to keep the overview. Although, e.g., the European Cooperation for Space Standardization (ECSS) standard includes instructions on how to investigate particle radiation, it does not provide an overall view. This paper shall support those in need of a comprehensive overview and provide comprehensive information about proton radiation spectra that can potentially be of use for space engineering tasks ranging from mission analysis to material and component design as well as qualification testing. The publicly accessible platforms OLTARIS, SPENVIS, and OMERE were examined for available proton spectra to be used. Exemplary, the particle radiation of solar cycle 23 is considered, which comprehends the years 1996–2008. A common drawback of the available models is their restriction to the MeV-range. Particularly when materials are directly exposed to the space environment, low energetic particles, specifically, the keV-range, are of high interest, since these particle transfer all their energy to the material. Therefore, additional data sources were used in order to include the usually neglected low energy protons into the derived spectrum. The data was transferred to common set of units and eventually could be compared and merged together. This includes a comparison of the most common models, incorporating data foundation, applicability, and accessibility. As a result, extensive and continues spectra are fitted that take all different models with its different energies and fluxes into account. Each covered year is represented by a fitted spectrum including confidence level as applicable. For solar active and quite times spectra are provided.

The similarity between a shock response spectrum (SRS) and a target shock specification is essential in evaluating the success of a qualification test of a space component. Qualification testing facilities often utilize shock response databases for rapid testing. Traditionally, the comparison of two shocks (SRS) depends on visual evaluation, which is, at best, subjective. This paper compares five different quantitative methods for evaluating shock response similarity. This work aims to find the most suitable metric for retrieving an SRS from a pyroshock database. The five methods are the SRS difference, mean acceleration difference, average SRS ratio, dimensionless SRS coefficients, and mean square goodness-of-fit method. None of the similarity metrics account for the sign of the deviation between the target SRS and database SRS, making it challenging to satisfy the criteria for a good shock test. We propose a metric (the weighted distance) for retrieving the most similar SRS to a target SRS specification from a shock database in this work. The weighted distance outperforms the mean square goodness-of-fit and other metrics in database SRS retrieval for rapid qualification testing.

Generally, people working in mining areas, face many risk factors. In order to safe guard the people working inside the mine its environmental parameters should be monitored. The hardware consists of electronic circuitry where a microcontroller is the principal processing unit. A graphical user interface is also implemented. A number of qualification tests are carried out. The already existing system uses a single monitoring system, but the proposed system can analyse different parameters like temperature , humidity and gas. Natural calamities like landslides occur due to soil erosion and heavy rainfall. This kind of natural disaster can be monitored using MEMS Sensor and Vibration Sensor. The temperature, humidity, gas sensor measurements have an accuracy of 89.01%, 98.55%, 90.5% and a resolution of 0.12% RH and 0.05 m/s. Since the consequences of mining cannot be avoided, its effect can be predicted to ensure the safety of coal mine workers. The monitored parameters can be communicated from underground to the surface using WUSN and LORA technology.

Standard qualification testing for semiconductors typically involves stressing devices at-or-near the limits specified in their data sheets for a prolonged period of time, or for a certain number of cycles. The goal of qualification testing is to have zero failures out of a large group of parts tested. By testing parts to the point of failure, an understanding of the amount of margin between the data sheet limits can be developed, but more importantly, an understanding of the intrinsic failure mechanisms of the semiconductor can be found.

Using basic scientific research methods, we have selected 24 professional capacity development exercises and 10 test qualification tests with sufficient reliability, informing students for the first-year students and the second - year of Da Nang University of physical training and sports.

Transformer bushing systems have exhibited vulnerability during past earthquakes. Based on past qualification tests, it was found that the seismic performance of transformer bushing systems is impr...

Backsheet cracking has been a major issue observed in the field; however, standardized qualification tests, such as IEC61215, are inadequate to reliably identify such failures of PV modules due to the lack of the critical weathering factors applied sequentially or in combination, such as those found in the service environments. To address this problem, we investigated the effects of various environmental variables on the degradation and failure behaviors of the polyamide-based backsheet in PV modules retrieved from five different locations, encompassing a variety of climates, including humid subtropical, hot-summer Mediterranean, tropical savanna climate and hot arid. The correlations between the degradation indicators and the weathering variables were further demonstrated by principle components analysis (PCA). We found strong relationships between: carbonyl formation and reflected solar radiation; hydroxyl formation and module temperature; yellowness and NO2 concentration, while no simple correlation could be found between a specific weathering factor and cracking. By introducing additional stress factors to the aged polyamide-based backsheet films with the novel “fragmentation test”, we successfully reproduced the field cracking behaviour. This study has demonstrated that different degradation modes of PV components respond differently to the environmental stresses encountered in service. Thereby, any accelerated laboratory test based on a single set condition or lacking key environmental variables would be inadequate to assess the long-term performance of PV modules and components. A new reliability-based methodology is proposed to quantitatively link laboratory testing with field results for the service life prediction of PV materials.

In European countries during the ХІХ-th century a system of qualification tests for candidates for teaching positions has been formed and evolved. The article deals with a cross section of complex tests for potential future teachers in Austria-Hungary of the beginning of the XX-th century. An example for consideration is the University of Lviv. The documents from archival funds have been processed, researched and summarized. It has been found out that the qualification tests for the university graduates, who wished to devote themselves to the teaching profession were complex. The purpose of the qualification tests was to find out the volume of professional theoretical knowledge and practical pedagogical skills of the candidate. The process of organizing and conducting the tests was handled by a special Examination Committee, consisted of the specialists of the respective subjects. The test set included the examination of mastering university courses, writing and defense of written scientific work, oral professional exams and pedagogical practice. During the study at the university, the student had to take courses in psychology, pedagogy, chosen profession and languages of teaching. After graduation, the student demonstrated the quality of theoretical knowledge gained at the colloquium in front of independent pedagogues. After completing the colloquium, the candidate for a teaching position wrote the scientific project in his specialty during several months. After the project defense came the turn of oral exams. Oral exams were intended to demonstrate proficiency in teaching and learning languages and were presented to profile teachers pedagogues. The final stage of testing for the candidate was the annual pedagogical practice in the city institutions. It took place under the supervision of university professors, school teachers and board members. Upon completion of practice, the examiner demonstrated his skills in open lessons and eventually received a certificate of the teacher of secondary school. The absence of a pedagogical practice teacher within five years after passing the qualification examination led to the necessity of re-passing all stages of professional tests.

This paper provides an analysis of the factors influencing the conducted emissions of interface converters, which are of increasing importance for the design and implementation of microgrids. Of particular interest herein is the approach selected for terminating the output port of such converters during qualification testing procedures. Current emissions standards provide considerable flexibility in the handling of output ports for such converters. This study provides a theoretical analysis of an interface converter consisting of a SiC-based single-phase inverter in a custom-built testbed for evaluating conducted emissions. The accompanying analysis demonstrates that the selection of output terminations plays a significant role in determining the resulting emissions, with a difference of up to 40 dB observed in the relevant emissions metrics for different configurations of output terminations. Overall, this study highlights the need to reevaluate the requirements of current emissions standards with the accelerating adoption of wide-bandgap semiconductors due to the increased high-frequency content in systems implemented with this technology.

The U.S. military uses performance in standardized weapons qualification tests as one benchmark of mission readiness. However, validity concerns have risen about the current qualification model in regards to its suitability to measure marksmanship ability in realistic, battlefield conditions as well as its relevance with recent weapon technological advancements. The present analysis provides an initial look at the relationship between performance in a standard weapons qualification test (qualification score) and performance attributes of marksmanship recorded prior to a field training mission. Marksmanship performance was measured using a simulator and a combined static-dynamic methodology capable of assessing the entire marksmanship process of moving, locating, positioning, and engaging targets. Results indicate that qualification scores in the current qualification model are a poor predictor of slow, untimed static marksmanship and a good predictor of high-paced dynamic marksmanship timing and mobility performance attributes during a rested state, prior to embarking on a mission.

To ensure that the SoC project complies with the requirements for efficiency on applied tasks, the entire route of developing SoC, starting with architectural design and ending with qualification tests of the topological list of chains, should be focused on early localization of performance problems. A critical point in terms of performance is the interconnect subsystem of the So C. As part of this work, a tool for generating tests, aimed at verifying the compliance of the system with the stated requirements, was proposed. This tool implements the generation of test scenarios based on the description of data streams and their interdependencies, taking constraints into account. Describing data streams at a high level of abstraction and considering constraints allows you to automatically generate both simple load tests and complex tests based on usage scenarios that require consideration of data dependencies. To automate the analysis of test results, an error analysis tool was developed, the task of which is to scan the test logs and find the reasons for their unsuccessful completion. This module helps to automate the decision to match the current state of the project with the test plan, thus helping to decide on the allocation of resources to the project.

Composite tanks for on-board gaseous hydrogen storage is one of key parts of the hydrogen fuel cell vehicle. Regulations, codes and standards (RC & S) are conducive to overcoming technological barriers to commercialization. This paper reviews the development of RC & S on composite tanks for on-board gaseous hydrogen storage and addresses their highlights on technical requirements. First, an overview of RC & S for composite tanks is introduced. Then, a comparative study on technical requirements of RC & S including service conditions, design requirements, materials, manufacture, qualification tests and management is presented. Finally, several major differences in RC & S, i.e., tank classification in ISO 19881 and penetration test method are discussed. Some issues for further research, such as initial burst pressure, material hydrogen compatibility and periodic inspection methods are proposed.

In this work, we report the results of industrial qualification tests run on medium voltage SiC MOSFETs rated for 3.3 kV/40 A and 10 kV/15 A. The JEDEC JESD47J.01 standard was used as a guideline to conduct HTRB (High Temperature, Reverse Bias), HTGB (High Temperature, Gate Bias), and TDDB (Time Dependent Dielectric Breakdown) tests. No devices were found to have failed the qualification tests, and long oxide lifetime was projected for constant operation under positive bias. This paper also reports for the first time the results of qualification testing of the MOSFET body diode on a large population of medium voltage SiC MOSFETs. Constant current stress at a current equal to the device forward rating was applied for 1000 hours. No degradation of any device parameter was observed for 3 lots of devices at both the 3.3 kV and 10 kV voltage rating.

We analyze the effectiveness of the qualification test method for communications satellite earth stations, implemented using a multi-user distributed measurement control system. We study the dependence of shortening the test phase on the number of organized operating sites, the technical characteristics of the spacecraft and the planned operational load of the on-board relay complex. We consider the possible increase in the commercial efficiency of a spacecraft over its lifetime.

The paper presents a research on testing protocols for seismic performance assessment and qualification of buckling-restrained braces (BRBs). The purpose of the study was to propose new loading protocols that consider the most demanding performance requirements available worldwide. In this study, the loading protocols for qualification testing of BRBs prescribed in the codes of four countries/regions, United States, Europe, China, and Japan, plus a non-official Canadian loading protocol, were consulted. The review focused on the background and characteristics, such as the maximum deformation amplitude, deformation range, and number of cycles, of each loading sequence. Then, a database composed of 35 BRB specimens, selected from 16 past experimental studies, was compiled to perform a series of simulations of quasi-static cyclic tests of BRBs under the five different loading histories. The OpenSees platform was used to carry out the modeling, calibration, and analyses. The demands imposed to BRBs were evaluated in terms of cumulative inelastic deformation and cumulative dissipated energy. In addition, the cumulative distribution of the hysteretic energy was defined as a parameter for the assessment of the amplitude-growth rule of the loading protocols. Based on the code review and analyses results, a series of criteria were established and two new loading protocols, GLP-1 and GLP-2, were proposed. Results demonstrated that both proposed loading histories impose superior cumulative inelastic demands and showed a good agreement with the reference cumulative distribution of the hysteretic energy. Thus, they are recommended as loading protocols for BRB qualification testing with global applicability.

The work examines the methodology for assessing the homogeneity of the control sample of interlaboratory qualification tests, which is the most important characteristic of determining its status. The criterion for assessing the homogeneity between the characterizing values of the samples is the root mean square deviation and standard deviation of the proficiency test of the control sample with the standard uncertainty of the assigned value, which is a requirement of the ISO 13528 standard. Ignoring this requirement may provoke a false assessment of the participated laboratories taking corrective action.

Dynamic monitoring of base isolated buildings is analyzed to evaluate structural behavior during earthquakes and gain experience on the specific behavior of rubber isolators. Some structures with seismic base isolation have been monitored during recent strong earthquakes in Italy, namely Amatrice earthquake (2016/08/24, Mw = 6.0) and Norcia earthquake (2016/10/30, Mw = 6.5) and aftershocks. For these structures, amplification phenomena have been observed up to about twice the accelerations on the superstructure, for very low energy value inputs. In these cases, however, monitoring revealed amplified accelerations extremely small, and very far from being able to damage the structure. Records from the ENEA permanent accelerometric network, installed on these structures, and the tests carried out on the same isolators during qualification tests of the same rubber isolators positioned below the analyzed structure, describe the behavior of the isolators in terms both of force and displacement defining two non-linear laws, for small and large displacement, derived from experimental data.

This paper presents the results of experimental tests on HVDC power cables and prototypes to validate the idea that the real current absorbed by the power cable can be different from the current given by the HVDC generator, depending on different variables, as the test voltage, the test clearances, the ambient conditions and so on. The impact of all the testing features and conditions is evaluated. Experimental conditions and methods utilized are shown in the paper as well.

Fukushima accident has caused serious damages to public health and environment. Licensees of nuclear power plants in China are required to take measures to prevent severe accident happening. Control and detection hydrogen in containment under severe accident is one of the improvement actions. This article has analyzed the requirements for hydrogen detection system and related tests requirements for this detection system. A comparison of IEC 61298 and IEC 61779 is made to find tests should be carried on a new developing detection system/equipment. Nuclear qualification tests also have been considered. One testing system frame has been put forward.