خيارات البحث
النتائج 121 - 130 من 150
The deformation monitoring system on the Brasa overpass in Riga [Latvia] النص الكامل
2024
Kraskevičs, Edgars | Celms, Armands | Rusinovs, Jevgenijs
Engineering structures such as bridges, overpasses, and viaducts constitute a crucial component of the infrastructure of any industrial city. The wide-scale industrialisation of the twentieth century transformed the urban landscape. Many designs and solutions have become morally and physically outdated since those times, yet their usage continues, which is not always safe. With the aging of infrastructure, the issue of their further safe use inevitably arises. Geodetic monitoring of structural deformations can provide control and safety, as well as gather data for designers and engineers. The data collected by deformation monitoring systems should form the basis for the reconstruction and maintenance project of infrastructural facilities. Deformation monitoring systems are designed for each object based on the parameters of the structure, taking into account the constructive features, materials, and the importance of the infrastructural object to the city traffic. It is not always possible to completely close an overpass during reconstruction, as this would affect the transport flow in a specific district of the city. Monitoring of recently put into operation structures will ensure the collection of deformation data for the survival analysis. Once the structural health is defined, the period of service life until scheduled maintenance will be determined. As a result of our research on the Brasa overpass in Riga, we developed a scheme for swift response to signals from the monitoring systemʼs sensors. Additionally, we ensured the safe operation of the old overpass during the construction of the new one by promptly utilising data obtained from the deformation monitoring system.
اظهر المزيد [+] اقل [-]The [European Green Deal] as a factor for changes in business: the educational perspective النص الكامل
2024
Beizitere, Ilona | Brence, Ieva | Rivza, Baiba
Sustainability, green growth and the European Green Deal principles are the cornerstones that should and will affect our lives. The aim of the paper is to provide possible improvements to higher education programmes to promote the implementation of the European Green Deal as a factor for changes in business. The research is based on investigations into the entrepreneurship students’ knowledge of the European Green Deal. A theoretical analysis of literature and policy documents were investigated to develop an appropriate questionnaire for the survey of Latvian university students. The research methods involve measures of central tendency and location, T-test, ANOVA and correlation analysis. The research results indicate that business curricula involve courses on Sustainable Development and universitiesʼ role in teaching the Green Deal because the students who hold experience in entrepreneurship report similar results if compared with students without experience in entrepreneurship. Students’ knowledge of the European Green Deal should be improved since there are a number of aspects where the answers were not correct. This, in turn, prompts the need to strengthen and diversify education, so that business transformation towards the Green Deal is successful. The curricula should be further improved, as it allows students to better understand EU and global trends in saving the planet and put the knowledge into practice in their companies.
اظهر المزيد [+] اقل [-]Development of professional communicative competences of students’ النص الكامل
2024
Davlatov, Keldiyor | Ilieva, Lola | Djumaniyazova, Malohat | Murtazaeva, Aisafar
In our republic in the process of preparing students for professional activity one of the urgent tasks is considered to be the development of their professional speech. It is very important for todayʼs specialist to be competent, competitive and able to communicate effectively in his future activity. However, the main problem is the teaching of professional culture and the holistic development of professional communicative competences. The aim of the article is to develop recommendations and methodological guidelines to ensure the cultural communication of future professionals. In particular, the experiment proves that the student should feel the benefit of learning a foreign language in the future and get used to independent work on the subject, and gradually the motivation to learn the language will appear. The study highlights the role of foreign language teaching in the interdependence of ‘language – communication – profession – cultureʼ, the interdependence of language and culture in the development of language skills, the systematic approach to the study of professional terms. It is a well-known fact that students, in addition to acquiring lexical and grammatical knowledge of a foreign language, should also have a perfect command of the culture and values of their country and of the country where the language is learnt. In order to effectively implement the business communication situation in the classroom, it is desirable for the student to ‘understand the foreignerʼ, to study and master the culture of the foreign country, the accepted rules and values. While doing research, the methodological recommendations and instructions for the systematic organization of foreign language teaching are given.
اظهر المزيد [+] اقل [-]The use of artificial intelligence by students of Information Technology programmes النص الكامل
2024
Sergejeva, Natalija | Vronska, Natalja | Briede, Baiba | Samuilik, Inna
The use of artificial intelligence (AI) tools in university education is a phenomenon of various directions: the potential of AI tools, skills, purpose and sense of usage. Each direction is worth of working out and introducing regulatory systems and deeper investigating users’ choice and managing the process of getting, navigating and creating information by means of AI. Therefore, one of the emerging scientific challenges is students’ abilities and personalised learning experience in the use of AI. The study is focused on the usage of AI in specific courses, and namely the students of Information Technology (IT) programmes from Latvia University of Life Sciences and Technologies (LBTU) and Riga Technical University (RTU). The aim of the study is to investigate the students’ ability, need and merit to use AI in learning numerical methods, mathematics and programming. The main data collection method used is a student survey. According to the main results, it is found out that respondents when solving the programming tasks sometimes used AI, while solving mathematical tasks respondents rarely used AI. AI actually did not help to solve the mathematical tasks, while it partly helped to solve the programming tasks. The use of AI partly helped the respondents to improve the knowledge and skills of programming. Acquiring the study course Numerical Methods respondents mainly used ChatGPT, but performing practical works respondents mostly did not use AI.
اظهر المزيد [+] اقل [-]The need and role of high-level math skills in engineering studies النص الكامل
2024
Zvirgzdina, Liga | Kopeika, Evija
This article examines the importance and necessity of high-level mathematical skills in engineering studies. It analyses the specific mathematical skills required for successful engineering education and their role in engineering studies. The results provide insight into how high-level mathematical skills contribute to the development of engineering competencies and enable engineers to solve complex problem scenarios. Key findings reveal that high-level mathematical skills are indispensable in engineering education, providing the tools needed to solve real-world problems and drive innovation in engineering. Mathematics is the language of engineering. It provides the analytical and problem-solving tools necessary for engineers to design, analyse, and optimize systems, ensuring that they meet safety, efficiency, and performance requirements. Engineers use math as a fundamental tool to make informed decisions and drive technological advancements across various engineering disciplines. Without math, engineering would be severely limited in its ability to design safe, efficient, and innovative solutions to the complex problems that engineers encounter in various industries. The questions contained in the article are investigated using survey data of university students. The purpose of this study is to research the relative applicability and level of knowledge of the learning material learned in secondary educational institutions in mathematics, based on the experience of school graduates and engineering students.
اظهر المزيد [+] اقل [-]Use of automatically obtained data in the quantitative and qualitative evaluation of harvester operator training النص الكامل
2024
Strubergs, Aigars | Sisenis, Linards | Sarmulis, Ziedonis
The study aims to find out the efficiency of periodic training of the harvester (cut-to-length) operator, using the automatically saved data of the harvesterʼs information system. It has been established that logging service providers and training institutions do not analyse the operatorʼs work before starting the training; therefore, the training is carried out according to certain, standard programs, without going into the previous performance of each trainee operator. The research uses data automatically saved by Ponsse harvesters during the year, obtained from Ponsse Manager. The study found that by using automatically saved data of the harvester information and performing data grouping with subsequent analysis, it is possible to determine the progress in the execution of specific stem processing operations and to identify operations where the instructor should pay increased attention during training. The research analysed the data of 3 operators, obtained while working with Ponsse harvesters in clear-cutting. In the study, it was found that operator A reduced stem processing time by 3%, labour productivity increased by 15%, and fuel consumption per l m⁻³ decreased by 14% over 3 months. Operator B, after training, saw a 20% reduction in stem processing time, a 13% increase in work productivity, and a 5% increase in fuel consumption l m⁻³ over 3 months. Operator C had a 10% increase in stem processing time, a 1% increase in labour productivity, and a 2% increase in fuel consumption l m³ after training.
اظهر المزيد [+] اقل [-]The composition and richness of ground cover vegetation in drained forest stand النص الكامل
2024
Liepina, Agnese Anta | Jansone, Diāna | Samariks, Valters | Jansons, Āris
Forest drainage is a common management practice, carried out in order to improve tree growth; however, the alterations in hydrological and microclimate dynamics can cause diverse changes in the characteristics of ground cover vegetation. The aim of study was to characterise the composition and richness of ground cover vegetation in drained forest stands, where the groundwater levels have been affected by the reconstruction of drainage diches. Research was conducted in the hemiboreal forests of Latvia. Three study sites were chosen, measurements of groundwater level, stand parameters and projective cover of ground covered vegetation took place in two stands which underwent reconstruction and restoration of the drainage system in 2019, and a control stand, where the drainage system had not been restored. For assessing the relationship of ground cover vegetation in relation to groundwater level and stand factors, DCA analysis was used. The differences between stands, regarding the species projective cover and species composition, were assessed by ANOSIM (Analysis of similarities). Sites, where drainage ditches were fully or partially reconstructed exhibited a greater diversity of ground cover vegetation species compared to the control stand, where no renewal of drainage ditches had occurred. Conversely, the control stand displayed a higher projective cover of the bryophyte layer. The composition of ground cover vegetation species differed amongst all studied stands, the varying stand characteristics and co-dominant tree species in canopy layer had a more pronounced influence on ground cover vegetation, making it complicated to evaluate direct impact of groundwater level.
اظهر المزيد [+] اقل [-]Rosemary essential oil by hydrodistillation: SPME-GC-MS characterization النص الكامل
2024
Calvo-Gomez, Octavio | Ruzibayev, Akbarali | Akramova, Rano | Salijonova, Shakhnozakhon | Gaipova, Shakhnozakhon | Khodjaev, Sarvar
Rosemary (Salvia rosmarinus) is an aromatic herb with a multitude of uses. It is both a seasoning in various dishes, and a natural remedy for several diseases mainly due to its anti-inflammatory and anti-oxidative effects. Plus, it is also used in cosmetic industry and for improving agriculture practices and helping the environment, since it may be a natural antimicrobial. It is worth noting that this plant is also grown and commercialized in Uzbekistan, thus, if added value is given to rosemary’s products, it has potential for improving living conditions and helping in the economy of local farmers and entrepreneurs. In this work, we discuss a technique for obtaining rosemary essential oil, rich in terpenes, by vacuum assisted hydrodistillation. This is a solventless environmentally friendly and safe technique that allows the obtention of an added value rosemary product where terpenes, compounds responsible for most of rosemary’s properties, are the most abundant. Two samples of locally acquired rosemary were sourced, essential oil was extracted, and characterization was then performed by Solid Phase Micro Extraction (SPME) and Gas Chromatography – Mass Spectrometry (GC-MS). As a comparison, a direct injection of a dilution of one of the essential oil samples was also performed. It was concluded that samples of essential oil obtained from both sources were entirely composed of terpenes or terpene derivatives. Besides, SPME was a superior method when compared to direct injection, since a larger number of volatiles was able to be identified.
اظهر المزيد [+] اقل [-]Chemometrics as an aid to quickly evaluate galactomannans through infrared spectroscopy النص الكامل
2024
Calvo-Gomez, Octavio | Ruzibayev, Akbarali | Salijonova, Shakhnozakhon | Gaipova, Shakhnozakhon | Khodjaev, Sarvar | Khakimova, Zulfiyakhon | Rakhimov, Dilshod
Galactomannans, composed of galactose and mannose, may form gels and are considered safe because of their non-toxic, biodegradable, and biocompatible nature. As a result, they are widely utilized in the food industry as stabilizers and thickeners. Among galactomannan producing species, guar gum and locust bean gum are particularly important due to their economical relevance. Guar gum and locust bean gum are often adulterated with cellulose gums like xanthan gum and carboxymethyl cellulose (CMC). Adulteration of galactomannans with other gums may introduce uncertainties regarding functionality and complicate quality control, posing a potential problem for the food industry. Among the different techniques which have been used for determining and characterizing galactomannans, Fourier Transform Infrared Spectroscopy stands out. Especially when coupled to Attenuated Total Reflection (ATR), analyses are performed rapidly, with a minimum sample preparation, and without the need for solvent or previous extraction mechanisms. However, food is a very complex matrix that contains a high number of components which generate a multitude of spectral information and large data sets. Consequently, additional data processing tools such as chemometrics are needed to be able to draw useful information from spectra. Our goal in this work is to show how to optimize conditions for instrumental analysis by infrared spectroscopy of galactomannans and its constituent monomers and create a chemometric model where galactomannans could be differentiated as a single group. We successfully optimized the PCA model obtained after chemometric processing of infrared data through reducing dimensions by loadings selection.
اظهر المزيد [+] اقل [-]Identification of the trace and toxic elements of wheat cultivated in different regions of Uzbekistan النص الكامل
2024
Djaxangirova, Gulnoza | Kurbanova, Nodira | Kurbanov, Bakhtiyor
In Uzbekistan, the main food product is bread, which is produced in various forms from local and imported wheat. Most of it is not studied by microelement analysis. The objective of this study is to quantify trace elements in locally produced wheat from various cultivated regions of Uzbekistan. Four different varieties of wheat are cultivated in Sirdarya, Tashkent region, Kashkadarya and Fergana were selected for analysis. Next, a comparative analysis of the elemental composition like iron, zinc, potassium, calcium etc., in the selected samples were studied. To carry out the above aims, an innovative research method was chosen, which is called improved instrumental neutron activation analysis. This method differs from others in its high accuracy in determining trace elements and its multi-element nature. Using this method, we can understand how insufficient nutrients are in baked goods made from wheat grain grown in Uzbekistan. Based on the results of the study, it can be recommended to enrich the soil with fertilizers high in iron and zinc. As a result, in turn, will have a positive effect on the health of the population, since today there is a shortage of the above listed elements. It was also revealed that the concentration of potassium and calcium in wheat cultivated in Uzbekistan is in a high state than other elements. Using the chosen method, two toxic elements were determined and according to the analysis for toxic elements, all four samples are recommended for consumption, as they do not exceed the permissible level for food safety.
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