Specific Requirements Research Articles

ОГНЕВЫЕ ИСПЫТАНИЯ АВТОНОМНЫХ ДЫМОВЫХ ПОЖАРНЫХ ИЗВЕЩАТЕЛЕЙ

Рассмотрению подлежат результаты экспериментальных огневых испытаний автономных дымовых пожарных извещателей. Проанализированы положения международных и отечественных нормативных стандартов, регламентирующих требования к дымовым пожарным извещателям и методам их испытаний. Рассмотрены литературные источники по разработке стендов для проведения испытаний дымовых пожарных извещателей. В результате проведенных экспериментов получены числовые данные по времени срабатывания различных автономных дымовых пожарных извещателей при применении тестовых очагов пожара ТП-2 и ТП-7, уточнены условия их месторасположения, отличных от стандартных. Сделаны выводы о нецелесообразности применения тестового очага пожара ТП-7 для сертификационных испытаний автономных дымовых пожарных извещателей. Combustion of basic materials that are typical for residential and administrative facilities is accompanied by the release of smoke. Detection of smoke, which is a solid aerosol, is carried out by different type of smoke fire detectors, which have special technical requirements depending on the conditions of their use. Among the various types of smoke fire detectors, it is worth highlighting smoke detectors, which are one of the effective technical means for warning people in case of fires. Smoke fire detectors contain in a single housing a typical smoke detector and an audible and/or speech signal source that is triggered when the smoke alarm is activated. Smoke detectors are not connected to fire alarm system loops and operate autonomously. The sound signal of the smoke detectors can wake up sleeping person or notify a person in an adjacent room that smoke has begun to form. Installation of smoke detectors is relevant on residential sector facilities, hotel rooms, and hostels. The adopted provisions for fire testing of smoke fire detectors in international, regional and interstate standards require clarification of the types of test fires and determination of the conditions for fire testing of smoke fire detectors. According to State Standard GOST 34698, ISO 7240-9, EN 54-9, the room for fire testing has a height of 4 m. This height is not typical for residential and administrative buildings. The height of this type of buildings, as a rule, is not more than 3 m. The test fire source TP-7 is applied for rooms with a height of 3 m and less in accordance with ISO 7240-9, EN 54-9. To simulate a room height of 3 m, tests are carried out in a standard room with the test fire source installed at a height of 1 m from the floor level. Two series of experiments were carried out with test fire sources TP-2 and TP-7 that were installed on the floor and at a height of 1 m above the floor level. There were analyzed the test results, presented in the article in the form of graphs. There were found no significant deviations in the test results. It is concluded that the use of test fire source TP-7 during certification tests is not justified.

PRIVATE-LAW APPROACH TO THE DEFINITION OF THE MILITARY-INDUSTRIAL COMPLEX IN THE IMPLEMENTATION OF INVESTMENT ACTIVITY

Within the framework of the presented work, the concept of the military-industrial complex is studied from the perspective of the theory of investment law, current investment legislation and special regulatory requirements related to this area. In the doctrine of Russian jurisprudence, there are opposing points of view regarding the definition of the military-industrial complex. Some authors reduce it exclusively to the fulfillment of the state defence order, which is neither a correct formulation, since the state defence order is an integral part of the military-industrial complex, nor its entire component. Other researchers, on the contrary, interpret the military-industrial complex too broadly and include the Russian Ministry of Defence and its institutions, military units, etc. The article concludes that the military-industrial complex has special distinctive (qualifying) features in certain aspects of its private law regulation.

Application of Pulse Gas-Discharge Electroacoustic Transducer for Non-Destructive Testing

This paper presents the results of a gas-discharge electro acoustic transducer of two configurations, operating on the basis of a pulsed discharge in air at atmospheric pressure. The influence of the electrode configuration on the acoustic characteristics of the transducer is considered. It is shown that a change in the volume of the discharge chamber and the inter electrode gap have a significant effect on the radiation intensity of the transducer. The features that arise when using open and closed type electro acoustic transducers in flaw detection problems are revealed. It is shown that an open type gas-discharge electroacoustic transducer is a sufficiently powerful broadband source of the excitation signal and has prospects for use in non-destructive testing. A closed type gas-discharge electroacoustic transducer has advantages when testing materials with special requirements for surface cleanliness or the magnitude of the applied external electric field.

Analysis of the efficiency of suburban passenger transportation on the Lviv railway sections

A developed transport system ensures the population's needs in safe movement and guarantees stable functioning and development of the production sphere. Despite being consistently unprofitable, suburban transportation by railway remains attractive for many population categories. The developed railway network, the low cost of transportation, and the capacity reserve of most sections partially compensate for the existing shortcomings and contribute to further development and open new prospects for attracting additional users of transport services. The main problems of suburban passenger transport, which worsen the quality of the services provided and affect the competitiveness of railway suburban transport compared to other modes of transport, are examined in this article. During the analysis of the schedule of suburban trains departing and arriving at the Lviv station, irrational management decisions were found that left room for improvement. In addition, the load factor of rolling stock on the routes Lviv-Sambir-Sianky and Sianky-Sambir-Lviv was determined, and it dropped to 40% during the follow-up, which indicates inefficient use of rolling stock. The ratio of the time the train stays at the stops to the total duration of the route in suburban traffic is also calculated. The time on the road for the Sambir- Stryi route was 69%, and the technical speed was only 21.7 km/h. The results obtained in the article are also typical for many other monitoring areas, indicating this problem's repeatability. The positive experience of European countries in solving similar problems allows us to react correctly to the situation and take short-term measures to change the dynamics to a positive one without additional time losses. It is also worth noting that a set of measures to improve the services provided to passengers must be carried out according to the requirements of the Technical Specifications for Interoperability, which must be ensured upon joining the European Union. Further investigations should analyze the flow of passengers at all stations and stopping points to identify the main points of creating passenger flow on researching routes.

ResJobFit - end-to-end artificial neural networks based technology for job-resume matching

With the ever-growing expansion of online recruitment, a reliable person-job matching has become increasingly crucial. Due to different experience, education and specialization requirements, as well as location considerations, specified in the job advertisement, various aspects should be taken into account for reliable matching and ranking of candidates. It has been shown that matching of resumes and vacancies can be approached as either pair classification or semantic similarity search based on embeddings. While classification approaches process each vacancy-resume pair sequentially, thus resulting in quadratic time complexity, independent text embeddings and ranking is a much more efficient and scalable solution, since it has linear time complexity. In this article semantic similarity search to rank suitability of candidates with regards to vacancies has been used. ResJobFit - an end-to-end Artificial Neural Networks based technology for job-resume matching is proposed. ResJobFit technology consists of Segmentation, Parsing, Summarization and HR Embedding Module models, and their outputs (vector and attributes defining each resume or job advertisement), as well as a Vector Database in which the records are stored. Unsupervised text embeddings training for HR domain encapsulating two novel training objectives - intra- and cross-section contrastive alignment is introduced. Pretrained BERT-base model is adapted by teaching it to match summary-last employment sections of the resume with parts of the same vacancy or employment section. As baselines TFIDF, BERT, E5 and GTE have been used. The proposed unsupervised training strategy was compared against SimCSE, DeCLUTR and ConFit approaches. NDCG, MAP and MRR are used as metrics for measuring accuracy of the designed algorithm. It has been shown that the novel training objective lets it achieve significant improvement in comparison to other unsupervised training approaches. Improvement of 11% in NDCG was achieved by adapting the DeCLUTR training strategy for the HR domain based on exploiting the structure of resumes over the classical DeCLUTR training strategy on the task of ranking summaries of vacancies and resumes generated by large language models. 2% and 6% have been achieved using ResJobFit and ResJobFit with requirements matching over state-of-the-art ConFit model on the task of ranking full-text vacancies and resumes.

Navigating Dietary Complexities: Understanding Gluten Intolerance Awareness among Stakeholders

Background: Eating out is not only a common trend these days but also necessity for many who live away from their families especially students pursuing higher education. With growing trend of food hypersensitivity catering industry needs to get driven for such special requirement. Objective: This study aimed to check the awareness of stakeholders for gluten intolerance with respect to the market and sensory evaluation of the developed alternative. Methodology: A cross-sectional study was conducted on consumers and food business operators of Central Delhi. Consumers were 18 years and above and claiming to be gluten intolerant. Food business operators were local shopkeepers running food stalls and bakery. A self -structured questionnaire was designed for stakeholders respectively. Developed gluten alternative was sensory evaluated by consumers on 9-point hedonic rating scale for its overall acceptability. Data was analyzed for the stakeholders by using descriptive statistics. Results: The results indicate that majority (53.65%) consumers were familiar with the symptoms of gluten intolerance like headache and digestive issues. Furthermore, majority (68.3%) identified rice and corn to be an alternative for gluten. Level of satisfaction from market for availability of alternatives is medium (61%).Sensory score for developed alternative was 7.19 ±1.53. Regarding food business operators’ majority (53.12%) receive customer request for availability of gluten free products, 46.87% are affirmative to provide alternatives subjected to demand of consumers. 53.12% also showcased interest in receiving training or resources for gluten intolerance and lactose free cooking skills and outsourcing of such food items. Conclusion: In general stakeholders showcased awareness about their food intolerance and improved availability of alternatives in market. At the same time willingness of food business operators to offer such products on menu. The study recommends to provide training to food business operators for provision of diversified menu for prospective consumers.

Purification of U from U-10Mo scrap generated during the fabrication of high performance research reactor fuel

ABSTRACT A low enriched U-Mo alloy fuel is under development to replace highly enriched U fuels currently used in United States high performance research reactors. The alloy casting and fuel fabrication processes will generate scrap streams containing low enriched U (LEU) which must be recovered. Solvent extraction processes were designed using the Argonne Model for Universal Solvent Extraction (AMUSE) to purify solutions containing 20 and 50 g/L U. The feed for the solvent extraction processes was prepared from solutions generated from the dissolution of U-10Mo-Zr foils and U-10Mo-Zr-Al mini-plates. The U purification processes were demonstrated using two, 16-stage banks of miniature mixer-settlers. The solvent extraction experiments demonstrated that all design objectives for the U purification processes could be met. The U recovery in the product stream for each flowsheet was ≥99.9%. The flowsheet demonstrations also showed that the purity of the U Product will meet the requirements of the ASTM International C1462-21 specification for LEU metal enriched to less than 20% 235U. The AMUSE modeling for both flowsheet demonstrations was validated by comparing predicted and measured concentrations of U, Mo, and Zr in the exit streams and stage samples at steady-state conditions in the mixer-settlers.

Implementing Scientific and Technological Territorial Potential Through Interregional Integration Based on the “Smart” Specialization Approach

Relevance and objectives of the research. Regional scientific and technological potential can be revealed and fully realized only taking into account the possibilities of interregional partnership and cooperation and provided that the priorities of scientific and technological development of the regions are aligned. The purpose of the article is to analyze the possibilities and prospects for using the “smart” specialization approach to the formation and development of interregional scientific and technological spaces.Materials and methods. The methodological basis of the study was the general scientific methods of system analysis, abstraction, induction and deduction, analogy, modeling, specification, comparative and logical research methods. The special methods used were content analysis of literature, bibliometric, comparative geographical and others. The empirical basis of the study was based on data from the Federal State Statistics Service, the statistical information platform Statista, as well as individual strategic regulatory documents. The instrumental base for the analysis was made up of the VOSviewer program, version 1.6.20.Results. The author analyzed and generalized theoretical approaches to the definition of “interregional scientific and technological integration”, presented the author’s understanding of “smart” specialization as a strategic approach to the development of regional structural and innovation-technological policies. Unique tools for using this approach are identified and described based on an analysis of European experience. The main barriers to the practical implementation of “smart” specialization in order to build effective interregional scientific and technological integration are analyzed (departmental inconsistency, the content and specificity of requirements for the targeted use of federal budget funds, fragmentation and multidirectionality of measures and instruments of state support, etc.), and key tools for its support are identified. The role of the state in the processes of building internal cooperation chains, the formation of interregional scientific and technological spaces in order to ensure the comprehensive implementation of regional potentials is revealed.Conclusions. It is advisable to implement a unified scientific and technological policy that ensures the synchronization of actions of management subjects at different levels, which will require the elimination of departmental inconsistencies in its implementation, the establishment of uniform transparent principles and rules of the game, a verified system of economic incentives, and, in general, the creation of a high-quality institutional environment. In addition, for the purpose of scientific and technological development of regional spaces, it is necessary to constantly monitor the status and results of using various government support instruments with a view to their subsequent prioritization and linking “smart specialization” strategies with real support measures and distribution of subsidies.

Participation at the margins – participation practices from the viewpoint of young people in residential care

ABSTRACT This article critically discusses young service users’ participation rights and participation processes in residential group care concerning the challenges, requirements, and opportunities that such a form of organised participation entails for them. A comparative analysis of findings from two qualitative studies from Germany and Switzerland is an empirical basis. Experiences of lived, negotiated, or subtle struggles for the participation of children and youth in everyday institutional life are presented. Identified resistant practices of children and youth, which are of great importance to them, deviate from the usual organisational and normative requirements for participation. The article closes a vital research gap: It presents young people's strategies for dealing with organised and sometimes tokenistic participation. The focus on the self-will of the young actors offers the possibility of supplementing a frequently normative discourse about securing children´s rights in alternative care without making the lifeworld of the young service users and their views a starting point for interventions and legal interpretations. Moreover, the results of both research projects indicate that participation in the everyday life of young people in residential care organisations entails special requirements and challenges, which will be presented here in more detail.

Applying bayesian data analysis for causal inference about requirements quality: a controlled experiment

It is commonly accepted that the quality of requirements specifications impacts subsequent software engineering activities. However, we still lack empirical evidence to support organizations in deciding whether their requirements are good enough or impede subsequent activities. We aim to contribute empirical evidence to the effect that requirements quality defects have on a software engineering activity that depends on this requirement. We conduct a controlled experiment in which 25 participants from industry and university generate domain models from four natural language requirements containing different quality defects. We evaluate the resulting models using both frequentist and Bayesian data analysis. Contrary to our expectations, our results show that the use of passive voice only has a minor impact on the resulting domain models. The use of ambiguous pronouns, however, shows a strong effect on various properties of the resulting domain models. Most notably, ambiguous pronouns lead to incorrect associations in domain models. Despite being equally advised against by literature and frequentist methods, the Bayesian data analysis shows that the two investigated quality defects have vastly different impacts on software engineering activities and, hence, deserve different levels of attention. Our employed method can be further utilized by researchers to improve reliable, detailed empirical evidence on requirements quality.

NU-NeRF: Neural Reconstruction of Nested Transparent Objects with Uncontrolled Capture Environment

The geometry reconstruction of transparent objects is a challenging problem due to the highly noncontinuous and rapidly changing surface color caused by refraction. Existing methods rely on special capture devices, dedicated backgrounds, or ground-truth object masks to provide more priors and reduce the ambiguity of the problem. However, it is hard to apply methods with these special requirements to real-life reconstruction tasks, like scenes captured in the wild using mobile devices. Moreover, these methods can only cope with solid and homogeneous materials, greatly limiting the scope of the application. To solve the problems above, we propose NU-NeRF to reconstruct nested transparent objects without requiring a dedicated capture environment or additional input. NU-NeRF is built upon a neural signed distance field formulation and leverages neural rendering techniques. It consists of two main stages. In Stage I, the surface color is separated into reflection and refraction. The reflection is decomposed using physically based material and rendering. The refraction is modeled using a single MLP given the refraction and view directions, which is a simple yet effective solution of refraction modeling. This step produces high-fidelity geometry of the outer surface. In stage II, we use explicit ray tracing on the reconstructed outer surface for accurate light transport simulation. The surface reconstruction is executed again inside the outer geometry to obtain any inner surface geometry. In this process, a novel transparent interface formulation is used to cope with different types of transparent surfaces. Experiments conducted on synthetic scenes and real captured scenes show that NU-NeRF is capable of producing better reconstruction results than previous methods and achieves accurate nested surface reconstruction under an uncontrolled capture environment.

Features of legal regulation of supervisory boards activities in state joint-stock companies

The article examines the legal status of supervisory boards in joint-stock companies with 50 percent or more of their shares owned directly or indirectly by the State. The author analyzes the main tasks and highlights the peculiarities of corporate governance in state-owned companies, and identifies the specifics of the supervisory board’s independence in the public sector, which consists in the interaction of the supervisory board not only with the executive body, but also with the shareholder represented by the relevant management body. The author analyzes the legislative norms governing the activities of supervisory boards in public joint-stock companies and the OECD Guidelines on Corporate Governance in State-Owned Enterprises. The author highlights the specifics of legal regulation of the supervisory board of a joint-stock company with 50 percent or more of its shares owned directly or indirectly by the State, namely, special requirements for the minimum number of independent directors, impossibility of establishing additional grounds for early termination of powers of the supervisory board members, mandatory formation of committees, impossibility of delegating the functions of the supervisory board to the general meeting, etc. The author analyzes the question of the authority of the meetings of the supervisory board of state-owned companies in the event that the majority of independent directors are absent in the supervisory board. Researched the legal consequences of non-compliance with the legal requirement for a majority of independent directors on the supervisory board and concludes that there are no legal consequences, and the supervisory board will be competent in this case and will be able to perform its duties in full within its competence. It is determined that the absence of legal consequences in such a situation constitutes a shortcoming in the legal regulation of the status of the supervisory board. At the same time, the author concludes that the lack of responsibility of the management body for violation of the terms of competitive selection of independent members of the supervisory board and the provision of the management body with the opportunity to perform the functions of the supervisory board for the period of martial law also constitute shortcomings in legal regulation.

Learning approaches, motivation, and specialty preference form a nexus: a cross-sectional study among preclinical medical students

IntroductionThe learning approach of undergraduate medical students can be influenced by motivations toward learning medicine as well as perceived outcomes such as their specialty preference in the future. In this study, we analyze the relationships between learning approach, motivation to study medicine, and factors related to their specialty preference.MethodsWe conducted a structured questionnaire-based survey of undergraduate medical students after one year of joining. Learning approaches were assessed using a published questionnaire used on medical students after adapting it to our context. Questionnaires validated earlier in our setting were used to assess motivation to study medicine and specialty preference. Factor scores were extracted to examine the relationships between motivations to study medicine and specialty preference with their learning approaches. The data obtained were also analyzed based on the demographic characteristics of students.ResultsDeep learning approach factors such as deep motivation, deep strategy as well as surface motivation were correlated positively (Pearson’s r > 0.2 and p < 0.05 for all mentioned analyses) with the motivation to study medicine factor for professional calling and with the personal satisfaction factor for specialty preference. Deep motivation and deep strategy factors of the learning approach were also correlated with the professional growth factor of specialty preference.ConclusionDeep learning approaches appear to be related to motivation to study medicine factors related to the professional calling and demands of the profession as well as for perceived personal satisfaction related to future specialization requirements.

Role of Lower Eyelid Reconstruction in Complete Functional Rehabilitation

Objective: To present a case of reconstruction of a full-thickness lower eyelid defect.Case report: Male patient Y. aged 71 years was admitted to the Scientific Research Institute – Ochapovsky Regional Clinical Hospital No. 1 (Krasnodar, Russian Federation) with the diagnosis: cancer of skin of the lateral canthus of the left eye, T1N0M0, stage I, clinical group II. According to the medical history, the neoplasm was self-detected 5 years ago. Histology findings revealed micronodular basal cell carcinoma.After a general clinical examination, the patient underwent surgery to remove the neoplasm of the lower eyelid skin and lateral canthus and reconstruct the defect using a lateral infraorbital fat pad flap, local tissues, and a free autologous cartilage graft. The configuration of the soft tissues of the eyelid was restored. Soft tissue edema was not observed. The functional state of the lacrimal apparatus was fully preserved. The esthetics of the soft tissue was rehabilitated.Conclusions: Reconstruction in such esthetically significant area as the middle third of the face is associated with special requirements for graft formation and positioning. A gentle and functionally justified method for restoring the parameters of the tarsal plate, conjunctival sac, and lower eyelid skin ensures complete rehabilitation of patients and improves their quality of life.

Simultaneous Quantification of Serum Symmetric Dimethylarginine, Asymmetric Dimethylarginine and Creatinine for Use in a Routine Clinical Laboratory.

Background Symmetric dimethylarginine (SDMA) and asymmetric dimethylarginine (ADMA) are naturally occurring amino acids classed as uremic toxins by the EUTOX working group. SDMA is principally excreted through the kidneys and is a well-known renal function marker, ADMA is a potent inhibitor of nitric oxide production. Here, we describe the development of a rapid and sensitive liquid chromatography tandem mass spectrometry method for simultaneous measurement of SDMA, ADMA and creatinine. Method Serum samples were prepared by protein precipitation and dilution with acetonitrile prior to injection onto a Waters TQS-Micro. Multiple reaction monitoring was used to detect SDMA, ADMA, creatinine, and their corresponding internal standard transitions after separation with a HILIC analytical column. Sample stability and intra-individual variation studies were also assessed following ethical approval. Results The retention time for creatinine was 0.43, SDMA 1.10 and ADMA 1.14 minutes. Mean recovery for creatinine was 103%, SDMA was 100% and ADMA was 103%, matrix effects were minimal (<6%). Lower limit of quantitation for creatinine and SDMA/ADMA was 17.5 µmol/L and 0.1 µmol/L respectively. Analytical imprecision showed a coefficient of variation <10% for all analytes across the working range of the assays. Intra-individual variation for creatinine was 4.7%, SDMA 7.5% and ADMA 7.6%. Discussion We have developed a rapid assay for LC-MS/MS measurement of SDMA, ADMA and creatinine in a routine clinical laboratory. It is simple, reproducible, and easy to perform. The stability of SDMA and ADMA pre- and post-centrifugation allows for their routine use without any special sample handling requirements.

Investigating Open Source LLMs to Retrofit Competency Questions in Ontology Engineering

Competency Questions (CQs) are essential in ontology engineering; they express an ontology's functional requirements as natural language questions, offer crucial insights into an ontology's scope and are pivotal for various tasks, e.g. ontology reuse, testing, requirement specification, and pattern definition. Despite their importance, the practice of publishing CQs alongside ontological artefacts is not commonly adopted. We propose an approach based on Generative AI, specifically Large Language Models (LLMs) for retrofitting CQs from existing ontologies and we investigate how open LLMs (i.e. Llama-2-70b, Mistral 7B and Flan-T5-xl) perform in generating CQs for existing ontologies. We compare these results with our previous efforts using closed-source LLMs and we reflect on the results.

Effect of Using Fine Volcanic Ash Instead of Crushed Basalt Filler in Hot Mix Asphalt

Numerous studies over the years have demonstrated the significance and impact of filler in influencing the physical and mechanical properties of Hot Mix Asphalts (HMAs). To overcome such issues, as environmentally friendly alternatives, several different materials for construction have been proposed. This led to an investigation into the potential use of fine volcanic ash (FVA) as a hot mix asphalt filler alternative. In order to prepare bituminous concrete mix sample with conventional basalt filler (BF) as control mix. The Marshall Mix design approach was used to calculate the effective bitumen content. A total of 15 bituminous concrete mix specimens with bitumen content of 4%, 4.5%, 5%, 5.5%, and 6% were created, and the optimum asphalt content was 5.24 %. The impacts of five different (FVA) samples with filler contents of 15%, 30%, 45%, and 60% by weight were compared with respect to bituminous concrete performance. The Marshall stability of a total of 30 samples with varying amounts of (FVA) were investigated. The outcomes were compared with a conventional bituminous concrete mixture. The results showed that fine volcanic ash may substitute 30% of the basalt filler at a bitumen content of 5.24%, 13.84 KN Marshall stability value, 4.0% air voids, 74.77% VFB, 2.380 g/cm3 bulk density and 3.54 mm flow. Therefore, the combination of 30% Fine Volcanic Ash by weight of Basalt Filler satisfies the ASTM Specifications, while the remaining VA content satisfies the basic requirements of the ASTM Specifications.

Isolator shape transition impact on hypersonic internal waverider intake flow distortion

This paper examines the impact of scramjet isolator shape transition on hypersonic internal waverider (IWR) intake. The IWR intake is designed using the osculating axisymmetric flows and streamline-tracing methods. The new Internal Conical Flow “M” basic flowfield is utilized to provide the flow information for the design method. The intake is equipped with three isolators: one with a constant cross section and two with variable cross sections with circular and rectangular exits. The entrance shape and area of the three isolators are fixed to the intake throat shape and area. The exit area of the three isolators is maintained as the entrance one. Numerical computations of three-dimensional configurations reveal that the isolators with variable cross section shapes demonstrate a higher uniformity index than those with constant cross section shape. Thus, the isolator shape transition has decreased the flow distortion of the hypersonic IWR intake system. The three isolators exhibit varied wall pressure distribution depending on the isolator cross section shape, and the total pressure recovery ratios at the three isolators' exit planes are similar. The wall pressure distributions and key performance parameters at the intake throat section, including total pressure recovery, compression ratio, and Mach number, remained consistent across the first part of the intakes. Therefore, changing the cross section shape of the isolator while keeping the area constant could enhance the flow uniformity of compressed air without negatively impacting the intake system's performance. This allows a separate shape selection of the IWR intake throat and the scramjet combustor entrance to fulfill their special requirements.

Multi-objective optimisation of frequency offset and quality factor in semi-conical microwave resonant cavity for syrup brix measurement

Accurate measurement of syrup brix is essential for automated sucrose production because it significantly influences the quality and efficiency of the production process. The microwave resonant cavity method, an effective approach for syrup brix measurement, imposes special performance requirements on the cavity structure design, potentially necessitating unique shapes to capture the properties of the target substance. Traditional empirical design methods for these sensors have significant limitations with nonconventional shapes, often requiring further tuning and analysis of the parameters to adapt to complex geometries and achieve optimal performance. Previous studies have indicated that syrup brix variation can be predicted by the electromagnetic field characteristics of the resonant cavity, specifically the resonant frequency and quality factor, thereby allowing this relationship to be leveraged for sensor optimisation. Therefore, this study presents a systematic multi-objective optimisation approach using electromagnetic simulation software (ANSYS Electronic HFSS) and an Adaptive Reference-based Non-Dominated Sorting Genetic Algorithm (ARNSGA-II), which optimises the frequency offset and quality factor to enhance the sensor sensitivity and accuracy. Experimental comparisons between the optimised and conventional cavity designs demonstrate substantial improvements, with a 60.8% increase in the frequency offset and a 67.2% enhancement in the quality factor. Furthermore, applying the optimised design to a predictive model reduced the mean absolute error to 1.43°Bx, representing a 38.4% improvement compared to the empirical design-based resonant cavity. Results demonstrated that this study provides a robust framework for optimising complex cavity structures and offers valuable insights for the development of high-precision microwave sensors tailored for syrup brix measurements.

Development and testing of a remote calibration device for the temperature field of environmental testing equipment

Abstract Temperature is one of the important parameters for the calibration of environmental testing equipment. Due to its special working requirements and large volume and weight, the demand for on-site inspection and calibration of environmental testing equipment has always been high. Conducting research on remote calibration devices for temperature fields in environmental testing equipment is beneficial for improving the testing efficiency of environmental temperature and humidity, reducing the workload of testing personnel, and further reducing customer testing costs. By using ANT Wireless technology and using SHT3X temperature and humidity sensors to create a temperature field calibration device for environmental testing equipment, the above functions can be achieved. After testing, the maximum transmission distance of a single node can reach 70 meters, and the maximum networking distance between multiple nodes can exceed 1,000 meters. It can adapt to high and low-temperature impact tests at -20°C~60°C, and the response speed of temperature and humidity sensors is slightly slower than traditional temperature measurement thermocouples. It is suitable for calibration and detection of environmental testing equipment with good insulation performance.