Analysis Code Research Articles

Chemical Blast Standard (1 kg)

Abstract Chemical explosions create blast waves with large overpressure disturbances. It is important to develop a standard blast model based on data to accurately predict acoustic blast-wave amplitudes near detonations and invert for explosion energy from distant observations of blast-wave signals. However, open data from large, controlled chemical explosions with reliable ground truth can be challenging to find. The lack of access to such data could limit the number of contributions to related research and potentially stifle the rate of discoveries or validation of existing models. To address these data scarcity problem, we have curated and compiled a standardized set of 817 blast-wave waveforms from 19 distinct high-explosive events. The blast-wave waveforms are standardized to a 1 kg trinitrotoluene explosion using scaling laws and corrections for location effects. A brief overview of the dataset is presented along with explosion feature models as well as recommendations for extracting explosion features. The resulting dataset is distributed to an open repository in both Seismic Analysis Code and pandas DataFrame formats containing the waveforms, the scaled distances, and the sample rates.

Modeling of distribution parameters for upward steam-water boiling flows in subchannels of a vertical rod bundle

ABSTRACT In simulations of two-phase flow behavior in nuclear reactors, subchannel analysis codes are often used to evaluate the void fraction within a BWR fuel bundle in detail. When solving the momentum conservation equation averaged over a subchannel cross-section for upward two-phase flows, the distribution parameter is required to consider the void fraction and velocity distributions in the subchannel cross-section. In this paper, constitutive equations were developed for the distribution parameters for dispersed two-phase flows applicable to the inner, edge, and corner subchannels, which are typical subchannels in a fuel bundle. The distribution parameters could be calculated by giving the void fraction and the velocity distribution. Therefore, the distribution parameters were evaluated and modeled as a function of the geometrical parameters by assuming the void fraction and velocity distributions with bulk and subcooled boiling for each subchannel type. The developed constitutive equations were evaluated by comparing them with the distribution parameters estimated based on the NUPEC rod bundle void fraction test data. The developed distribution parameter model was implemented into the subchannel analysis code NASCA and compared with the measured cross-sectional average void fraction of the NUPEC rod bundle void fraction test data. In comparison with the original NASCA code, which assumed the distribution parameter to be unity, the improved NASCA with the distribution parameter model decreased the mean error of the measured cross-sectional average void fraction to less than half of the result of the original NASCA code, both in absolute and relative differences.

Simulation using representative data selection for transboundary radiation effect evaluation by Nuclear Accident Consequence Analysis Code (NACAC)

ABSTRACT Global radionuclide dispersion from Fukushima nuclear accident urged several countries to begin evaluating the radiation effects from neighboring countries. The representative data selection simulation is one of the evaluation methods providing practical results with reasonable computational resources. However, it is mostly used in the domestic radiation effect evaluation. This study investigated and modified this simulation method for transboundary radiation effect evaluation. The effects of selected area boundaries, optional weather parameters, and sampling rate, critical parameters in the representative data selection scheme, are sequentially investigated on the calculated results. The evaluation is performed by Nuclear Accident Consequence Analysis Code (NACAC) with hypothetical accidents at Fangchenggang NPP in China. It is revealed that area boundary and optional weather parameter selection insignificantly impact the predicted results, but the sampling rate condition affects the predicted results. Good agreements comprising dispersion characteristics and total effective dose equivalent by simulation using representative and sequential data selections are shown with absolute mean bias error lower than 2.4 × 10−3 mSv, root mean square error lower than 5.7 × 10−4 mSv, and correlation coefficient value higher than 9.1 × 10−1.

Parametric analysis of masonry arches following a limit analysis approach: Influence of joint friction, pier texture, and arch shallowness

Among the most characteristic structures in historical constructions for crossing large spans are the masonry vaulted structures by utilizing their geometric stability to safely transfer the loads to supports with regard to their negligible tensile strength. The ability of masonry piers to bear such transferred stresses and safely convey them to the support is directly related to their structural integrity, as well as to a number of other factors. Using an in-house limit analysis code, a study on the crucial parameters impacting the safety level of piers under the thrust of arches is performed. Parameters such as pier texture, joint friction angle, and arch shallowness, namely, shallow, semi-circular, and pointed arches, were investigated under three load scenarios: horizontal and concentrated vertical live load applied at mid-span and quarter-span. The main findings of this work show that all studied parameters have a significant influence on the structure response. Higher friction values, sharper arches, and piers that follow the rule of art result in higher collapse multipliers. Furthermore, this work emphasizes the importance of accounting for the sliding mechanism and masonry texture, parameters that are often neglected.

A Comprehensive Study on the Advancements of Man and Machine in Network Security and Coding Theory

The article offers a comprehensive analysis of network coding, communications security, and coding theory, examining their applications and advancements. It evaluates the fundamental concepts and methodologies utilized in these fields while shedding light on current progress and potential future research directions. The implications of the study discussed in this article extend widely across the communication sector, with immediate practical applications across various disciplines. One of the key areas covered in the article is the development of novel error-correcting codes and coding algorithms, which contribute to enhancing communication reliability. Additionally, the integration of machine learning and artificial intelligence (AI) techniques into network communications security is explored, highlighting their potential to bolster safeguarding measures. Furthermore, the incorporation of security controls into connected devices and Internet of Things (IoT) networks is addressed, acknowledging the need to ensure security in these interconnected systems. To ensure the reliability and security of network communications and foster innovation and growth within the communication sector, the article concludes that coding theory and network communications security must continue to evolve and progress. By pushing the boundaries of these fields, researchers can address emerging challenges, improve existing systems, and pave the way for future advancements in communication technology.

Mapping Continuity and Change in German Strategic Culture, 1999–2022

ABSTRACT This article investigates German foreign and security policy from 1999 to 2022 through the prism of strategic culture. In contrast with previous studies on German strategic culture, this article employs a mixed research design to examine areas showing major changes and areas of relative continuity. By using NVivo’s two analytical tools (word frequency analysis and matrix coding analysis), the article conducts a computer-based content analysis of German official strategic discourses in the foreign and security realm. The findings reveal that although some of the foundational elements have been preserved and further strengthened, German strategic culture appears to have exhibited more changes since 2014, particularly in terms of the geographical scope of security concerns, perceptions of key threats and Russia. The article argues that Germany’s understanding of security has shifted towards a normative dimension that places greater emphasis on values and rules, and that Germany’s security concerns are no longer confined to European regional security but rather extend further afield.

The intersection of static analysis and security code reviews: A collaborative model

The intersection of static analysis and security code reviews: A collaborative model

Corporeality Affected by the Loss of a Loved One – Manifestations of the Body in the Experiences of Former Wards of Social Rehabilitation Centers

RESEARCH OBJECTIVE: The aim of the study was to investigate the bodily dimension of the loss of a loved one and ways of dealing with such an experience manifested in action.
 THE RESEARCH PROBLEM AND METHODS: The main research problem was formulated as a question: How do former wards of social rehabilitation centers experience and what meaning do they assign to the death of a loved one? The study used the biographical method, while the autobiographical narrative interview was used for data acquisition.
 THE PROCESS OF ARGUMENTATION: The theoretical framework of this study on the boundary situation of the death of a loved one is Karl Jasper’s approach as well as Edith Stein’s theory of empathy, from which analytical codes were derived was discussed.
 RESEARCH RESULTS: The death of a loved one experienced as a loss generates feelings that manifest in bodily forms of expression. The suffering resulting from the loss led to the development of new patterns of action: escapist and developmental-escapist.
 CONCLUSIONS, INNOVATIONS, AND RECOMMENDATIONS: The basic conclusion is that the loss of a love one as a boundary situation, when one is not looked after and lives alone leads to abnormal social functioning. Thus, such experiences should arouse a great deal of attention from people caring for children and youth.

Alcohol Social Media Marketing in Hong Kong: A Content Analysis of Facebook Posts

PurposeThe near universal use of social media by young people in many parts of the world has led to increased exposure to alcohol social media marketing (SMM). This study aimed to examine the content of SMM posts from alcohol brands and venues in the southern China region. MethodsThis study randomly sampled posts from Hong Kong Facebook pages of 10 well-known alcohol brands (n = 639) and four popular drinking venues (n = 335) between 2011 and 2019. Content analysis, using deductive and inductive coding, was conducted on SMM posts to identify common marketing strategies (e.g., promotional giveaways) and themes. ResultsAlcohol SMM posts increased eight-fold during this period and showed continuous adaptation to regional tastes and drinking culture. Alcohol SMM strategies included explicit encouragement to drink, real-world event tie-ins (e.g. concerts, sporting matches), and special postings during local holidays such as Chinese New Year. Viewers were actively encouraged to interact through “likes”, shares, and comments on SMM posts. Alcohol brands had substantially higher user interactions than drinking venues (mean = 228.7/post vs. 19.0/post; p < .05). Alcohol SMM themes included celebratory events, friendship, cultural heritage, and popular music. SMM also promoted an exclusive, aspirational lifestyle, and emphasis on the high quality of their products. Only 8.1% of the brand posts and none of the venue posts contained responsible drinking messages. DiscussionAlcohol SMM has been increasingly promoting social norms that encourage heavy drinking in young people. Future policy discussions in this emerging alcohol market region should consider regulation of alcohol SMM.

Preliminary analysis focusing on in-vessel thermal hydraulics in loss-of-heat removal systems in a sodium-cooled fast reactor

Accident scenarios for the safety evaluation of sodium-cooled fast reactors (SFRs) are categorized into two groups: Anticipated Transient Without Scram (ATWS) and Loss-of-Heat Removal System (LOHRS). The latter is subdivided into two scenarios—Loss-of-Heat Sink (LOHS) and Loss-of-Reactor Level (LORL)—depending on the initiating event. With the development of SFRs, research on ATWS has been paid much attention to due to its rapid accident progression, which could lead to significant radioactive release. Conversely, the significance of LOHRS has increased in recent decades due to lessons learned from accidents at the Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company. However, compared with ATWS, finding and evaluation tools for LOHRS have been limited. Hence, code development is initiated to enhance the severe accident analysis code AZORES, which the Nuclear Regulation Authority developed for the safety evaluation of SFR accidents. This enhancement is achieved by coupling AZORES with plant dynamics code ADYTUM in order to deal with more detailed thermal hydraulics behavior in reactor cooling system. The paper describes the coupling methodology, focusing on the thermal–hydraulic model as the first step of code development and its application. The coupling has been confirmed to be well achieved through a preliminary analysis of LOHS, comparing the results of coupled and single AZORES. The comparison of the analysis results between LOHS and LORL by the AZORES coupled with ADYTUM has been conducted to identify the key phenomena in accident progression. The comparison shows that the coolant leak area and the pressure drop at the piping of the reactor cooling system affect accident progression in LOHS. Consequently, the coupled AZORES is capable of predicting in-vessel thermal–hydraulic behavior in LOHRS successfully, reflecting accident conditions and plant design appropriately.

Study on the mixing performance of mixing vane grids and mixing coefficient by CFD and subchannel analysis code in a 5×5 rod bundle

Mixing Vane Grid (MVG) is one of the most important structures in fuel assembly due to its high performance in mixing the coolant and ultimately increasing Critical Heat Flux (CHF), which avoids the temperature rising suddenly of fuel rods. To evaluate the mixing performance of the MVG, a Total Diffusion Coefficient (TDC) mixing coefficient is defined in the subchannel analysis code. Conventionally, the TDC of the spacer grid is obtained from the combination of experiments and subchannel analysis. However, the processing of obtaining and determine a reasonable TDC is much challenging, it is affected by boundary conditions and MVG geometries. In is difficult to perform all the large and costing rod bundle tests. In this paper, the CFD method was applied in TDC analysis. A typical 5 × 5 MVG was simulated and validated to estimate the mixing performance of the MVG. The subchannel code was used to calculate the TDC. Firstly, the CFD method was validated from the aspect of pressure drop and lateral temperature distribution in the subchannels. Then the effect of boundary conditions including the inlet temperature, inlet velocities, heat flux ratio between hot and cold rods and the arrangement of hot and cold rods on MVG mixing and TDC were studied. The geometric effects on mixing are also carried out in this paper. The effect of vane pattern on mixing was investigated to determine which one is the best to represent the grid's mixing performance.

Experimental study of non-condensable gas effects on sonic limit of sodium heat pipe

Due to unexpected gas leakage and long-term operation, the non-condensable gas (NCG) inevitably exists in high-temperature alkali metal heat pipe. Previous studies have mainly focused on its influences on startup and steady state operation characteristics of heat pipes. However, few of them conducted experiments to study the effects of NCG on sonic limit, which usually occurs during heat pipe startup or during steady state operation when the heat transfer coefficient at condenser section is high. In present work, experimental and analytical studies are conducted to the explore the effects of NCG on sonic limit of sodium heat pipes. With the heating power ranging from 500 to 1400 W, the sonic limit of 1 m-long sodium heat pipes with artery wick and axial groove wick are obtained based on oil-cooling system, which can widely adjust the cooling capacity at condenser section. The amount of NCG in heat pipe is estimated by Heat Pipe Transient Analysis Code (HPTRAN) and verified by experimental data. It is found that the existence of NCG in heat pipe leads to the decrease of maximum heat transfer rate under sonic limit. The mechanism of NCG effects on sonic limit is discussed based on phenomenological analysis. By introducing the added back pressure, a modified model to predict sonic limit considering NCG effect is proposed and the comparison with experimental data shows good agreements.

High-Fidelity Transient Analysis with STREAM Based on the Predictor-Corrector Quasi-Static Method

The predictor-corrector quasi-static method (PCQM) is used to solve the transient problem in the STREAM code, a steady-state and transient reactor analysis code with the method of characteristics. In PCQM, the angular neutron flux undergoes a factorized split to form the product of shape and amplitude functions. The time-dependent neutron transport equation is solved to obtain the shape function whereas the amplitude function is obtained by resolving the exact point kinetics equations (EPKEs). A two-level coarse mesh finite difference technique is implemented to reduce the transient running time of the transport solution. Moreover, high-order polynomial interpolation is applied to the kinetics parameters utilized in EPKEs to reduce the error when the reactivity insertion is nonlinear. Several numerical benchmarks are solved to justify the application of the procedure, proving that the method maintains solution accuracy.

Promoting intracultural understanding and language proficiency through video creation: a schema activation perspective

In a global era where nuanced cross-cultural communications have become essential, mastering English language skills and acquiring cross-cultural competence pose a significant challenge for L2 learners residing in regions where English is not prevalently spoken. The aim of this study was to investigate how Taiwanese language learners’ perceptions, cultural appreciation, and language learning as key component in socio-cultural communication are influenced by engaging in video creation projects designed to present their local culture to a global audience. Participants were 69 students enrolled in an 18-week undergraduate course entitled Multimedia English. Data were collected from the students’ midterm essays and final oral presentations, detailing the process of video production. These data were examined utilizing thematic analysis and Matrix Coding Query. The findings demonstrated that the involvement in this interactive and student-centered video creation project improved students’ comprehension of diverse cultures, understanding of their own cultural context, and boosted their English language proficiency. The research phase was a pivotal juncture in their learning trajectory, as it served to activate their inherent knowledge and understanding of their own culture. This project also encouraged the students to assume greater ownership of their learning, thereby influencing their overall success. The paper concludes by discussing practical implications and other pertinent considerations.

Collision Simulation of a Floating Offshore Wind Turbine Considering Ductile Fracture and Hydrodynamics Using Hydrodynamic Plug-in HydroQus

This paper intends to introduce the applicability of HydroQus to a problem of a tanker collision against a semi-submersible type floating offshore wind turbine (FOWT). HydroQus is a plug-in based on potential flow theory that generates interactive hydroforces in a commercial Finite element analysis (FEA) code Abaqus/Explicit. Frequency response analyses were conducted for a 10MW capacity FOWT to obtain hydrostatic and hydrodynamic constants. The tanker was modeled with rigid elements, while elastic-plastic elements were used for the FOWT. Mooring chains were modeled to implement station keeping ability of the FOWT. Two types of fracture models were considered: constant failure strain model and combined failure strain model HC-LN model composed of Hosford-Coulomb (HC) model &amp; localized necking (LN) model. The damage extents were evaluated by hydroforces and failure strain models. The largest equivalent plastic strain observed in the cases where both restoring force and radiation force were considered. Stress triaxiality and damage indicator analysis showed that the application of HC-LN model was suitable. It could be stated that applications of suitable failure strain model and hydrodynamics into the collision simulations were of importance.

Upgradation of fission gas release model in the nuclear fuel analysis code FuSPAC

The evaluation of fuel performances in the whole life cycle is important to the fuel integrity. In our previous work, a fuel performance analysis code FuSPAC was developed and validated against the in-pile test data and FRAPCON code. In the current work, this code was upgraded by replacing the modified Forsberg-Massih for fission gas release (FGR) with a mechanism model. The microscopic behaviors related to the FGR, including the gas atom diffusion, trapping, re-solution and bubble nucleation inside the granular particles, the vacancy diffusion at the inter-granular boundaries, the grain growth and the grain recrystallization were modeled. The upgraded FuSPAC code was validated against the in-pile test data for FGR and internal void volume. The sensitivity analysis on the sub-models shown that the intra-granular fission gas diffusion, the re-solution, and the inter-granular vacancy diffusion had significant effects on the FGR. The effects from rod power can be well reflected by the upgraded code compared to the original code.

Automation of Language Sample Analysis.

A major barrier to the wider use of language sample analysis (LSA) is the fact that transcription is very time intensive. Methods that can reduce the required time and effort could help in promoting the use of LSA for clinical practice and research. This article describes an automated pipeline, called Batchalign, that takes raw audio and creates full transcripts in Codes for the Human Analysis of Talk (CHAT) transcription format, complete with utterance- and word-level time alignments and morphosyntactic analysis. The pipeline only requires major human intervention for final checking. It combines a series of existing tools with additional novel reformatting processes. The steps in the pipeline are (a) automatic speech recognition, (b) utterance tokenization, (c) automatic corrections, (d) speaker ID assignment, (e) forced alignment, (f) user adjustments, and (g) automatic morphosyntactic and profiling analyses. For work with recordings from adults with language disorders, six major results were obtained: (a) The word error rate was between 2.4% for controls and 3.4% for patients, (b) utterance tokenization accuracy was at the level reported for speakers without language disorders, (c) word-level diarization accuracy was at 93% for control participants and 83% for participants with language disorders, (d) utterance-level diarization accuracy based on word-level diarization was high, (e) adherence to CHAT format was fully accurate, and (f) human transcriber time was reduced by up to 75%. The pipeline dramatically shortens the time gap between data collection and data analysis and provides an output superior to that typically generated by human transcribers.

Effect evaluation on performance issues of passive safety system– Part Ⅱ. Passive emergency core cooling system

In this study, the effect of performance issues on the Passive Emergency Core Cooling System (PECCS), a type of Passive Safety System (PSS), was evaluated. The PECCS relies on natural phenomena such as gravity, density difference, and pressure difference to operate. Its driving force is lower compared to that of the active safety system, making it necessary to evaluate its performance in various transient situations. Major performance issues were identified through effect evaluation using a conceptual problem for the PECCS, and their effects on the system were analyzed using the system analysis code MARS-KS. Therefore, there are concerns about whether the PSS can sufficiently perform safety functions in various situations. In Korea, performance evaluation methodology for PSSs is being developed to dispel these concerns. As part of the methodology development, this study conducted the effect evaluation on performance issues. The study identified several major performance issues for the PECCS, including those related to pressure and heat loss of piping within the system, uncertainties in tank wall condensation modeling, and checks valve modeling. The evaluation of performance issues has led to the identification of the main factors to consider in PECCS modeling, which include: 1) the geometry and pressure drop of PECCS, 2) the occurrence of wall condensation in pipes and tanks, and 3) the behavior of check valves. Proper modeling of these factors is important in achieving accurate analysis results and preventing potential issues, such as premature check valve closure or incomplete coolant injection. In conclusion, the results of this study are expected to contribute to deriving safety analysis modeling guidelines for PSSs and design considerations for NPPs that utilize PSSs by improving the completeness of the developing performance evaluation methodology.

Evaluation of DNBR with neutronics calculation in LWR systems

The heat flux in a Light Water Reactor (LWR) system is used to estimate the Departure from Nucleate Boiling Ratio (DNBR) of the system which is an important thermal hydraulic parameter for nuclear reactors from heat removal point of view. The DNBR signifies an operational safety limit i.e. the nuclear power plant has to be operated with sufficient margin from the specified DNBR limit for assuring its safety. The DNBR is evaluated using a thermal hydraulic analysis code using inputs from neutronics calculation. The present paper presents the evaluation approach of minimum DNBR (MDNBR) during standard neutronics calculation. The DNBR calculation is performed using a core physics analysis code and burnup variation of MDNBR is studied for the full cycle length. The results of calculation are presented using the equilibrium core of 2700 MWth/900 MWe Indian Pressurized Water Reactor (IPWR). The calculations are performed using VISWAM-TRIHEXFA code system. The few group lattice parametric library for IPWR is generated by lattice analysis code VISWAM. The core follow up calculation for the equilibrium core configuration has been performed using core analysis code TRIHEXFA. A first order thermal hydraulic feedback model has been introduced into the 3D finite difference core simulation tool TRIHEXFA. The critical heat flux calculation, required for estimation of DNBR, has been performed using W-3 Tong and OKB-Gidropress correlations implemented in TRIHEXFA.

Climate and competition combine to set elevational distributions of tropical rainforest Drosophila (code for analysis)

Climate and competition combine to set elevational distributions of tropical rainforest Drosophila (code for analysis)