Browsing by Department "Dizaina, vides un ražošanas tehnoloģiju laboratorija / Design, Environment, and Production Technology Lab"
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- PublicationANALYSIS OF HIKING FOOD PROCESSING TECHNOLOGIES ON THE MARKET(2020)
; ;Iveta Dembovska; Ivo DembovskisThe food sector is one of the fastest-growing sectors, therefore it requires that producers follow food market trends and quickly respond to consumer demand. Besides, the producers have to comply with the increasingly strict conditions and regulations imposed on food producers in recent years. Food producers need to be able to develop products that are safe and have a long shelf life and at the same time, the manufacturers have to continuously diversify their products, create new flavor and aroma combinations, increase the nutritional value of the products while increasing the production volumes and considering energy efficiency, as well as environmental impact. The aim of the research is to study and analyse hiking food processing technologies on the market. Methods used in the research – monographic, synthesis, comparative method. The research developed proposals for manufacturers of hiking food for the design and manufacturing of new products. - PublicationANALYSIS OF LASER PROCESSING OF ARTIFICIAL LEATHER(2019)
;Pāvels Narica ;Ruta Laizāne; With the development of laser technologies, the field of application of lasers is developing as well. They are capable of processing numerous materials and are still finding their application in unexpected areas. In this case, lasers are studied as a system with which black and white color artificial leather can be processed. This modern material allows you to combine comfort, practicality and reasonable price in a finished product. The manufacturer of artificial leather provides wide possibilities of design. In this study laser beam was used for dark and light laser markings on black and white color artificial leather and in this work, it could be observed how CO2 and fiber laser processing influence this specific material.Scopus© Citations 1 - PublicationAnalyze of Leachate Composition in the Dumpsites of East-Latgale Region(2003)
; There are are 28 working or closed but not recultivated municipal solid waste dumpsites in East-Latgale now. A number of these dumpsites are situated near lakes, rivers, in old mineral quarries etc [3, 6]. All these dumpsites pollute groundwater, soil and present danger for human health. One of the dangerous factors is leachate which is generated in these dumpsites and which pollutes groundwate, soil and drinking water. The analysis of leachate sample chemical content in the biggest East-Latgale dumpsites “Ritini”, “Zvirgzdene”, “Zelceva” and “Mostovaja” has been done in 2002. The content of leachate depends on content of waste, dumpsite management etc. The most polluted leachate is in the biggest dumpsites of region – “Ritini” and “Zvirgzdene”. These are city dumpsites (Rezekne and Ludza). Significantly less polluted leachate is found in the dumpsites “Zelceva” and “Mostovaja”. This is valid for all analyzed parameters – COD, conductivity, Ntot., NH4 + and Cl. - PublicationASSESSMENT BY MACROINVERTEBRATES OF THE ECOLOGICAL QUALITY OF SHALLOW LAKE WITH RICH SAPROPEL SEDIMENTS(2023)
; ;Jana PaidereAija BrakovskaIn this research, the ecological quality of the Lake Vēveru (Latvia, Rēzekne district) according to macroinvertebrates was investigated. The Lake Vēveru has a large sapropel deposit. The Lake Vēveru is relatively little affected by human economic activity, the only moderate impact is sapropel mining in the lake in 2009-2012, it is planned to resume industrial sapropel mining in the lake. During the period of sapropel removal, a decrease in the transparency of water is noted due to the nutrient flow into the water mass, pH increases, the habitat of planktonic and benthic organisms is disturbed. Macroinvertebrates samples were collected and analyzed using standard methods in the open pelagic and littoral zones of the lake in different seasons. The ecological quality of the lake was assessed in accordance with the requirements of the European Water Framework Directive in Latvia. To characterize the ecological status of the lake the Latvian Lake Macroinvertebrate Multimetric Index was used. According to the Ecological Quality Ratio (EQR) the lake indicates a good ecological status of the water. However, a moderately low species diversity index indicates the dominance of certain taxa. In general, macroinvertebrates species that are often and widely found in Latvia and are environmentally tolerant have been found in the lake. Water temperature, pH, conductivity, dissolved oxygen, oxidation reduction potential, chlorophyll-α were measured with a HACH OTT DS5 Probe. Water transparency was measured using a Secchi disc.Scopus© Citations 1 - PublicationATTRACTIVENESS OF THE LUZNAVA MANOR’S OFFER(2017)
;Lienīte Litavniece ;Iveta DembovskaThe Luznava Manor is one of the newest tourist attractions in Rezekne municipality, which is still in development. The paper is the result of the Rezekne Academy of Technologies (RTA) research grant “Feasibility study of tourism product development for the Luznava Manor”. The paper is aimed to assess the attractiveness of the Luznava Manor. The theoretical aspects of destination attractiveness and criteria for its assessment are reviewed in the paper. During the research study, the expert questionnaire was developed and practically approbated; the results of the expert survey are summarized in the paper. The attractiveness of the Luznava Manor’s offer is assessed in accordance with the following criteria: ease of access, exterior, visitors’ facilities, restrooms, staff, accessibility, nature factors, importance of culture, and services. Currently, it is relatively difficult to evaluate the Luznava Manor’s tourism product as a global or European level tourist destination. According to the authors, the Luznava Manor is rather to be considered as a tourist destination of national, regional and local significance. - PublicationCHARACTERIZATION OF THE ZOOPLANKTON COMMUNITY OF A SHALLOW LAKE WITH ORGANIC-RICH SEDIMENT(2023)
; ;Aija BrakovskaJana PaidereIn this research, the ecological quality of the lake Vēveru (Latvia, Rēzekne district) according to zooplankton was investigated. Lake Vēveru has a large sapropel deposit with rich reserves of sapropel. Removal of sapropel requires organization of spatio-temporal monitoring to control the state or disturbance of the existing ecosystems in the long term. Zooplankton samples were collected and analyzed using standard methods in the open pelagic and littoral zones of the lake in different seasons. Quantitative samples of zooplankton in each sampling site were collected from the surface water layer at the depth of 0.5 m by filtering 100 l of water through an Apstein-type plankton net (64 µ). Biodiversity of zooplankton taxa in Lake Vēveru shows that the food base of juvenile and planktophagous fish is sufficient. The Shannon index according to the diversity of zooplankton taxa ranges from 0.84 to 1.52 by abundance, from 1.52 to 2.21 by biomass. - PublicationCHEMICAL AND BIOLOGICAL PROPERTIES OF THE LAKE BLUE CLAY(2017)
; ;Samanta Marija MisiņaJevgenijs LukašenoksIn this paper the chemical and biological properties of the lake blue clay are explored. A blue clay bed layer was found under the sapropel layer in the lake Plusons (area 4.8 km2, Ludza countries, Latvia). It has been determined that the lake Plusons blue clay has a colloid composition, which contains Na, Mg, K, Ca, Fe, Cr, Mn, Co, Ni, Cu, Zn, Cd, Pb, Al, Ag, Ba. In samples Candida albicans, Pseudomona aeruginosa, Staphylococcus aureus and a total number of aerobic mezofile bacterium have been defined. In microbiological analyses the presence of Candida albicans, Pseudomona aeruginosa, Staphilacoccus aureus has not been stated. The number of mesophyll aerobic microorganisms isScopus© Citations 2 - PublicationCLAY DETECTION IN LAKES OF LATGALE USING GROUND PENETRATING RADAR(2019)
; ;Kodors, Sergejs ;Juris SomsAigars AlksnisThe most common method to determine the presence of clay in lakebed is coring method. This method requires survey of the whole lake area using stratified sampling method which is time and physical labour consuming process. To lessen the amount of coring samples and narrow the area of clay survey thus making the whole process faster and more effective, research was made to determine the possibility to indentify clay and its sediments using georadar survey or ground penetrating radar (GPR) method. GPR data analysis and coring studies in lake Zeiļu were used to evaluate GPR as potential method in lake clay sediment research. GPR method was tested in summer and winter during ice-covered period.Scopus© Citations 3 - PublicationCLUSTER APPROACH IN THE TOURISM BUSINESS(2012)
;Iveta DembovskaOne of the approaches to development of the tourism industry at the regional level, based of market rules and principles are creation and development of tourism clusters. Clusters span numerous different companies, contribute to more efficient solution of socio–economic problems in the country as a whole, and in certain regions. Clusters centre around different companies, which have not cooperated in the past, to encourage their development. The cluster approach should make radical changes to content of the tourism development policy; it means that there is a need to promote and develop the system of relationships between economic operators and the national authorities rather to support individual companies or industries. Practically it enables creation and implementation of large trans–sectoral and interregional investment and innovation projects. - PublicationCOLOR MARKING OF STAINLESS STEEL AND TITANIUM WITH THE LASER OXIDATION METHOD(2023)
;Petar Tsvyatkov ;Emil Yankov; ; Marking of metal products is essential in many industrial processes. It is mandatory for the finished products according to regulations of the European and world legislation. Traditional marking usually creates contrasting symbols that can easily be erased and forged.In recent years, a new method for product identification has appeared - color marking. One of the advantages of this method is that it is difficult to counterfeit. This article aims to present the progress of color marking technology on two types of materials. Three groups of factors have been analyzed: the laser source; the technological process; material properties. Their role in obtaining a specific color marking on Ti and AISI 304 is shown. The results are presented in tables. Each color can be repeated only with strict observance of the three groups of factors. - PublicationCOMPETITIVENESS OF THE LUZNAVA MANOR(2017)
;Iveta Dembovska ;Lienīte LitavnieceCustomers become increasingly demanding due to globalization processes. This fact affects competitors to fight for better tourism products. The need for innovations in the market that can attract tourists increases and creates the competitive advantage. The most important elements that can form and develop the competitive advantage by using different skills are efficiency, quality, innovation, and satisfaction of customers' expectations. The paper is the result of the RTA scientific grant "Feasibility study of tourism product development for the Luznava Manor" programme. The aim of the paper is to explore and analyse the theoretical aspects of the competitive advantage and to identify innovations for improving the competitiveness of the Luznava Manor. The most important elements of the competitive advantage in the tourism industry have been studied, information on foods used at the beginning of the 20th century and recipes characteristic of Latvia in the period of time when the Kierbedz family lived in the Luznava Manor have been researched and summarized. It has been offered to supplement the soup assortment at the Luznava Manor with a cold salty soup ‘batvin’ or ‘holodnik’ of the authentic recipe and name, as well as a plan of communication measures to increase competitiveness has been proposed. Monographic, logical construction, scientific induction and deduction methods and a structured interview have been applied. - PublicationCOMSOL SIMULATION OF LASER WELDING OF ALUMINUM(2021)
;Ivaylo Balchev; ;Nikolaj AngelovThis research includes a Comsol Mutiphysics model describing the temperature distribution on aluminum during the laser conductivity welding process. The influence of laser power and speed on the welding process is discussed and compared with experiments. Numerical simulations of laser welding process have been performed to determine the temperature fields of laser impact to samples of aluminum. Numerical calculations are made for fiber laser. The plots of the temperature dependence on the surface and in the depth of aluminum samples on the velocity are analyzed for several power densities for this laser. - PublicationCOOKING CLASSES AS A NEW GASTRONOMIC TOURISM PRODUCT(2019)
;Lienite Litavniece; Iveta DembovskaTourism development contributes to the development of countries and regions. Gastronomic tourism, organization of culinary master courses, inclusion of special meals in the tourist offer can contribute to the diversification, originality and competitiveness of regional tourist offers. The aim of the study is to examine culinary master workshops as a gastronomic tourist product. The research shows that master culinary courses are offered mainly in the capital, their supply is limited in other regions, and information about organized master classes is missing. - PublicationCRITERIA AFFECTING CUSTOMERS' CHOICE: THE CASE OF REZEKNE CITY CATERING COMPANIES(2019)
;Lienīte Litavniece; Iveta DembovskaIncrease of the number of catering businesses is driven by the growing demand, since more and more people choose eating outside. This is encouraged both by the rising welfare level and by a shift of the paradigm manifesting the diner as a place to socialize. However, from the perspective of the company, it is important to identify the main reasons why customers choose a particular eating-place. The aim of the paper is to explore the criteria influencing customers' choice and to test these criteria applying them to Rezekne city catering companies. As a result, it has been concluded that there are many criteria reviewed in the theoretical literature that could help a company to determine the criteria influencing the customers' choice. The paper is written within the framework of the RTA scientific grant "Quality Assessment of Rezekne City Catering Companies". Within the grant project, an expert questionnaire had been developed to carry out a quality assessment of Rezekne city catering enterprises. Consequently, the authors had an interest to explore the reasons motivating customers to choose a particular Rezekne city catering company according five criteria: location, offer, quality of food and drinks, company's image, and staff. As a result, the authors conclude that the most important criteria among the respondents was the quality of food and drink, as well as the offer, though, the evaluation varies depending on the particular company's specifics. The main research methods are monography, logically constructive, graphic, sociological. - PublicationDEVELOPMENT OF PROFESSIONAL COMPETENCIES OF HOSPITALITY INDUSTRY SPECIALISTS WITHIN THE FRAMEWORK OF ACQUISITION OF EDUCATIONAL MODULE “ORGANIZATION OF HOSPITALITY SERVICES”(2015)
; Iveta DembovskaAccording to the SWOT analysis on the Latvian Tourism Marketing Strategy 2010-2015 carried out by the Tourism Development Agency in 2010, the lack of skilled labour force in tourism and hospitality industry, as well as the low level of professional qualifications are mentioned as one of the potential threats. The aim of the research is to examine and analyse the development of professional competencies of hospitality industry specialists within the framework of completion of the interactive educational module “Organization of Hospitality Services”. The tasks of the research are: to examine the theoretical aspects of formation, application and significance of interactive educational modules; to determine requirements, aim, structure and position of the interactive educational module in the education process. In the paper, the theoretical aspects of formation of interactive educational modules are examined; the content of the interactive educational module “Organization of Hospitality Services”, which is implemented within the framework of the study programme “Hospitality Management”, is offered; requirements, aim, structure and position of interactive educational module in the education process are determined. The opportunities of application of the interactive educational module “Organization of Hospitality Services” are wide enough: it may be applied not only in the training process of hospitality industry specialists, but also in order to raise the qualification level of managers at the intermediate level. A pilot research study concluded that completion of theoretical studies is not sufficient enough in order to acquire professional competencies at the highest level. The authors of the paper suggest acquiring practical skills, which is extremely important. The research methods: the logical and constructive methods, the scientific induction method, synthesis, document analysis, the monographic method, the graphic method. - PublicationDistribution of iron and iron compounds in the Kemeri - Jaunkemeri occurence of sulphide water(2015)
;Janis Prols; Iron concentrations, distribution and migration forms, depending on pH and oxidation – reduction potential, were analyzed in case of the Kemeri-Jaunkemeri occurrence (area about 240 km2) of sulphide containing water (maximal sulphides concentration – 74 mg/l), located in Latvia. Iron content was investigated in 457 wells located within all area of occurrence. Those wells were installed to two aquifers: the Quarternary multi-aquifer and Salaspils aquifer, where occurrence of sulphide containing groundwater is distributed. All groundwater of occurrence is classified in four types depending on oxygen, sulphides and organic matter content in the groundwater. Modeling of groundwater migration forms was carried out, and it is stated that iron migrates basically as Fe2 in oxygen and suphides non-containing water. Migration forms are influenced by concentration of organic matter in the aquifer. The portion of Fe2 migrating in a form of free decreases due to formation of complexes with fulvic and humic acids, which can reach 36.5% of all migration forms. Iron migrates as Fe(OH)3 in oxygen containing water (more than 99% of determined forms). Presence of iron is ascertained also in sulphides containing water, where iron migrates basically as (98.8% of determined forms). This occurs due to formation of complexes with sulphydes – FeHS- and Fe(HS)2o. - PublicationEDUCATIONAL TOURISM IN THE TRAINING OF FUTURE TOURISM PROFESSIONALS(2016)
;Iveta Dembovska; Velta ĻubkinaThe concept of educational tour (field trip) and the importance and role of educational tours in the training of future tourism professionals are explored and analysed in the paper. The concept of educational tourism is formulated and the types of field trips are identified in the result of the research. A sociological survey with the aim to find out opinions of tourism students on the necessity, preferable types, and duration of field trips was conducted as well.Research methods: the logical construction method, scientific induction, synthesis, the monographic method, methods of quantitative and qualitative analysis for processing the survey results. - PublicationEFFECT OF HEAT TREATMENT ON ELECTRICAL AND MECHANICAL PROPERTIES OF THE SOLID SAPROPEL(2017)
; ; ;Rene Castro ;Vladimir Solovyev ;Josef Timmerberg ;Alexander Cvetkov ;Sergey Gango ;Angelika Borkenstein ;Paul Beckmann ;Helmut Schütte ;Nikolai PuchkovSergey TrifonovIn this work changes of electrical and mechanical properties (hardness) of the solid sapropel after its heat treatment were researched. Changes of real and imaginary parts of dielectric permittivity, dielectric losses and specific electrical resistance depending on electrical field frequency in the range 0.01Hz- 1MHz were observed. Temperature dependences of AC (at 1 kHz) and DC electrical conductivity were studied. Chemical sample composition, IR spectra and structure of the solid sapropel were investigated. Heat treatment has a noticeable effect on the electrical characteristics of solid sapropel due to the strong influence of water on the charge transfer in this complex material. Charge transfer occurs predominantly due to ion migration and demonstrates strong dependence upon hydration - dehydration processes. After the heat treatment of the solid sapropel at the temperature of 1000C its hardness doesn’t change. If the sample of the solid sapropel is subjected to 20 min heat treatment at the temperature of 1500C, its hardness decreases by 5.4%, the number of C=C bonds decreases by 6.3±0.1%, the number of C=N bonds decreases by 2.2±0.1%, the number of C-C bonds decreases by 1,7±0.1%, the number of C-H bonds increases by 18.5±0.3%. It shows that in the temperature range 100-1500C destructive processes of the solid sapropel start, although visually (with optical microscope and with SEM) changes of structure are impossible to observe yet.Scopus© Citations 2