Journals Published by Vilnius Tech
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Trade liberalization, price transmission and household welfare: evidence from China
Get PDFThis paper estimates the welfare effect of trade through the price channel by jointly considering the consumption and income effect. The consumer price data and household survey data of China are used to conduct the empirical analysis. For assessing the consumption effect, the quadratic almost ideal demand system (QUAIDS) model is used to capture the substitution effect of price changes. We find that every household of China is better off due to the reduction of import tariffs, but there is a strongly pro-poor bias. More importantly, ignoring the substitution effect on the consumption side not only underestimates the absolute value of welfare changes but also distorts the distribution of welfare changes. Our results imply the importance of the consumption effect in estimating the welfare gain of households from trade liberalization. Our framework can also be extended to assess consequences of the opening policies of other economies.
First published online 05 June 202
Innovation spillovers as a driver of economic development: evidence from regions located in Central and Eastern European Union countries
Get PDFInnovation has been a core element in the economic development of countries worldwide. Although innovation often has a global impact, it is created in a particular location. This research focuses on regions from Central and Eastern European Union (EU) countries as they are in the process of catching up with more developed Western EU economies. This paper aims to explore the link between innovation level and economic development in Central and Eastern EU countries from a regional perspective as well as to examine the impact of innovation spread between these regions. The analysis applies spatio-temporal models for data on the regional innovation index and gross domestic product per capita from 2016 to 2022. The results of this research show that southeastern regions had, on average, a lower level of both innovation and economic growth than western and northern ones. The analysis also confirms the positive relationship between innovation and economic development in these regions. Finally, this research proves the existence of spatial innovation spillovers: the strongest effect in Polish (near its capital city’s region) and Romanian regions while the weakest one in Slovenia, Bulgaria, and further from the capitals of Romania, Poland, and the Czech Republic.
First published online 16 July 202
The capacity of absorption and the management of human resources in asymmetrical strategic alliances: the case of Moroccan SMEs
Get PDFPurpose – The aim of this work is to analyze human resources mechanisms in order to enhance the absorption capacity of SME in strategic alliances with foreign partners, the goal being to favor the transfer of know-how to these enterprises.
Research methodology – The methodology applied is quantitative, based on a questionnaire addressed to 108 SME. SPSS 25 software was used to analyze the result.
Findings – The results of the study underline the critical role employees’ play in the knowledge transfer process by dwelling on the need of an absorption and assimilation capacity since businesses with such capacities are conducive to the acquisition, putting into use and development as well as the creation of new skills and know-how.
Research limitations – The quantitative approach of this research could be complemented by qualitative analysis. Additionally, generalizing the results from a sample of SMEs opens avenues for future research in other developing countries. Temporal and contextual extension could also enhance the relevance of the conclusions.
Practical implications – Our results could be used to provide key indicators for managers of SMEs engaged in strategic alliances. The guidelines aim to streamline the transfer, acquisition, and development of new skills and know-how from foreign partners.
Originality/Value – This study innovatively clarifies the administration of human resources in SMEs’ in asymmetrical strategic alliances, offering valuable insights for research into management practices
The phenomenon of creative images of Dimash Qudaibergen in the context of sustainable development of the cultural values of Kazakhstan
Get PDFThe relevance of the research topic is justified by its contribution to the sustainable development of cultural values, using the example of the creative artistic activities of the renowned Kazakh singer, Dimash Qudaibergen. This scientific investigation identifies the insufficient coverage of the analysis of the singer’s stage image in the context of the importance of cultural values in shaping the concept of stage costumes. The aim of the research is to study the cultural connotations of stage costumes contributing to the sustainable development of the value orientations of Kazakh culture (through conceptual approaches in shaping values, artistic principles, functions of symbolic codes, signs, ornamentation, and archetypes). This study will address the exploration of cultural phenomena of Kazakhstan through the lens of national identity, contribution to the sustainable development of contemporary art, fostering creativity in art and culture, and influencing the younger generation through educational and media initiatives to promote cultural values. The research methodology encompasses theoretical methods, overview-conceptual analysis, inductive and deductive approaches, as well as the synthesis of data from these methodological approaches. The theoretical and practical significance of this research is demonstrated through the conceptual foundation for the creation of Qudaibergen’s visual stage costume image, interpreting his work as the “ontology of the music of the Eurasian Steppe”. The results of the research are conceptual justifications of the model of the ethnic costume of Kazakhstan, forming creative images of performers, and representing a phenomenon in the perspective of ensuring the sustainable development of Kazakhstan’s cultural values
Integrated index analysis for monitoring urban growth based on GIS and remote sensing data in Karbala province, Iraq
Get PDFRemote sensing techniques and GIS were used in this study to monitor urban growth in Karbala Governorate, Iraq. A compiled database was created from available Multi-temporal Landsat (TM, ETM+ and OLI) data from 2000 to 2018. The near infrared (NIR), visible red (R), and short infrared (SWIR) wavelength areas covered by Landsat bands have been used to generate spectral indices known as the Normalized Difference Built-Up Index (NDBI), Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI) and Normalized Difference Salinity Index (NDSI). Images of the Landsat 7 and 8 satellites that were free to download from the USGS website between the years of 2000 and 2018 were the data used in this study. The layers were classified and merged to reveal the dynamic changes of land cover in the study area. The result shows that the built-up area increased from 264.75 km2 in 2000 to 391.23 km2 in 2018, indicating an increase over 18 years, but over the same period, the amount of water decreased
Utilization of recycled carbide as adsorbent for adsorption of dyes and COD from textile waste
Get PDFThis study assessed the potential of carbide waste (CW), a by-product of the welding industry, as a cost-effective adsorbent for removing dyes and COD from textile wastewater. CW was prepared through drying, filtering, and shaping into 2 mm-thick tablets (3 mm diameter), followed by heating at 150 °C for 120 minutes. Characterization using FTIR and SEM-EDX confirmed functional groups like hydroxyl and carbonyl and significant surface morphological changes. Batch experiments achieved maximum color and COD removal efficiencies of 94.48% and 96.73%, respectively, at 75 g adsorbent dosage and 150 min contact time. Freundlich isotherm (R² = 0.9918 for color) indicated heterogeneous adsorption, and kinetic studies fit a pseudo-second-order model. The process was exothermic, spontaneous, and governed by physical adsorption. Regeneration trials showed COD removal efficiency remained 90% after four cycles. These findings establish CW as an efficient, sustainable adsorbent with promising environmental and industrial applications for textile wastewater treatment
Optimization of biogas production from Phragmites australis using first-order kinetic models
Get PDFThis study investigates the viability of Phragmites australis, commonly known as the common reed, as a sustainable feedstock for biogas production, emphasizing the effectiveness of pretreatment techniques to enhance biogas production. Given the invasive nature of Phragmites australis, the utilization of its biomass not only addresses environmental management challenges but also contributes to renewable energy solutions. The key objective is to evaluate mechanical and thermal pretreatment techniques on the anaerobic digestion performance of Phragmites australis using the first-order kinetic model biogas’ cumulative production and volatile solids (VS) degradation were estimated. Sensitivity analysis was used to assess how different degradation rate constants and final biogas yield affected the efficiency of biogas generation. The degradation of VS was significantly accelerated by higher temperatures and finer particle sizes. Results indicate that both mechanical and thermal pretreatment significantly enhance biogas yield and degradation rates, milling (<1 cm) and moderate thermal treatment (100 °C, 2 h) providing optimal results. These studies highlight that the selection of appropriate pretreatment methods should be based on their sustainability and effectiveness in terms of reducing energy consumption and environmental impact.
Article in English.
Biodujų gamybos iš phragmites australis optimizavimas, taikant pirmojo laipsnio kinetinius modelius
Santrauka
Šiame darbe tiriamas paprastosios nendrės Phragmites australis panaudojimas biodujų gamybai. Darbe vertinami optimalūs derliaus nuėmimo laikotarpiai bei veiksmingi pirminio apdorojimo metodai, siekiant maksimaliai padidinti metano išeigą. Atsižvelgiant į invazinį Phragmites australis pobūdį, jos biomasės naudojimas ne tik sprendžia su aplinkos taršos mažinimu susijusius iššūkius, bet ir prisideda prie atsinaujinančios energijos gamybos. Šiame tyrime taikomas pirmo laipsnio kinetinis metodas, siekiant ištirti mechaninio ir terminio apdorojimo poveikį Phragmites australis anaerobiniam apdorojimui. Taikant pirmo laipsnio kinetinį modelį buvo įvertinta kumuliatyvinė biodujų išeiga ir lakiųjų kietųjų dalelių (VS) skaidymas. Jautrumo analize buvo įvertinta, kaip skirtingos skilimo greičio konstantos ir galutinis biodujų kiekis paveikė biodujų gamybos efektyvumą. Rezultatai rodo, kad tiek mechaninis, tiek terminis pirminis apdorojimas žymiai padidina biodujų išeigą ir VS skilimo greitį, o malimas ir vidutinis terminis apdorojimas (100 °C, 2 val.) užtikrina optimalius biodujų išeigos rezultatus.
Reikšminiai žodžiai: anaerobinis skaidymas, biodujos, pirminis apdorojimas, Phragmites australis, kinetika
Evaluation of Life Cycle Assessment (LCA) and sound absorption properties of composite materials made from coconut and sugarcane fibers
Get PDFAgriculture plays a crucial part in the economic growth of several developing nations; however, it creates 1,300 million tons of waste each year, which generates environmental issues. Noise pollution, particularly in urban environments, is an expanding global health issue for emotional and physical health. Conventional synthetic sound absorption materials used for sound absorption pose environmental and health risks; therefore, agricultural wastes including coconut fiber and sugarcane fiber, are being sought for safer alternatives. Natural fibers as sustainable sound-absorbing solutions draw increasing research attention. This paper evaluates the Life Cycle Assessment of agriculture waste based on the SWM-GHG calculator to compare the waste management approaches by calculating the GHG emission related to the recycling and disposal of wastes from cradle to grave, and sound absorption properties of coconut and sugarcane fibers in composite materials. A non-toxic PVA binder was utilized to prepare samples with densities of 75, 100, and 125 kg/m3, and sound absorption was evaluated based on ISO 10534-2. The results show a cost-benefit trade-off in waste management where higher recycling reduces GHG emissions but increases costs; the Default Scenario results in the highest emissions (20,439 t CO2e/yr) at the lowest cost, and Scenario 3 results in the lowest emissions (5,148 t CO2e/yr) at the highest cost. Also, sugarcane fiber (75 kg/m³) achieved the highest absorption coefficient (0.94 at 800 Hz), while coconut fiber (125 kg/m³) reached 0.91 at 1000 Hz, making both suitable for acoustic applications, with coconut fiber excelling in mid to high frequencies and sugarcane fiber in low to mid frequencies, particularly at lower densities.
Article in English.
Kompozitinių medžiagų iš kokoso bei cukranendrių pluoštų gyvavimo ciklo analizė ir garso sugerties tyrimas
Santrauka
Žemės ūkis atlieka svarbų vaidmenį augant daugelio besivystančių šalių ekonomikai, tačiau kasmet sukuria apie 1300 milijonų tonų atliekų, kurios sukelia aplinkosauginių problemų. Triukšmo tarša, ypač urbanizuotose teritorijose, tampa vis aktualesne problema, darančia įtaką emocinei ir fizinei sveikatai. Įprastos sintetinės garsą sugeriančios medžiagos, naudojamos triukšmui slopinti, kelia pavojų aplinkai ir žmonių sveikatai, todėl ieškoma saugesnių alternatyvų iš žemės ūkio atliekų, tokių kaip kokoso ir cukranendrių pluoštas. Natūralūs pluoštai kaip tvarios garsą sugeriančios medžiagos vis labiau domina tyrėjus. Šiame darbe vertinamas žemės ūkio atliekų gyvavimo ciklas, siekiant palyginti skirtingas atliekų rūšis pagal šiltnamio efektą sukeliančių dujų (ŠESD) emisijas nuo žaliavos gavimo iki jų galutinio pašalinimo („nuo lopšio iki kapo“). Nagrinėjamos iš kokoso ir cukranendrių pluoštų pagamintų kompozitinių medžiagų kompozitų garso sugerties savybės remiantis ISO 10534-2. Mėginiams buvo naudotas netoksiškas PVA rišiklis, o jų tankiai buvo 75, 100 ir 125 kg/m³. Rezultatais nustatyta, kad atliekų tvarkymo srityje egzistuoja sąnaudų ir naudos balansas – perdirbimas sumažina ŠESD emisijas, tačiau didina išlaidas: pagal numatytąjį scenarijų gaunamos didžiausios emisijos (20 439 t CO₂ ekv./metus) už mažiausius kaštus, o pagal 3 scenarijų gaunamos mažiausios emisijos (5 148 t CO₂ ekv./metus). Be to, cukranendrių pluoštas (75 kg/m³) pasiekė didžiausią garso sugerties koeficientą (0,94 esant 800 Hz), o kokoso pluoštas (125 kg/m³) – 0,91 esant 1000 Hz. Kokoso pluoštas geriau sugeria vidutinių ir aukštų dažnių garsus, o cukranendrių pluoštas – žemų ir vidutinių dažnių, ypač esant mažesniam tankiui.
Reikšminiai žodžiai: gyvavimo ciklo vertinimas, ŠESD emisijos, kokoso pluoštas, cukranendrių pluoštas, garso sugerties koeficientas, triukšmo tarša
Engagement and flow in the job satisfaction of volunteers at a non-governmental organization (NGO) in Peru
Get PDFThe objective was to analyze how engagement and the state of flow influence the job satisfaction of volunteers. The design was non-experimental, cross-sectional, and the sample consisted of 1023 volunteers, selected through non-probabilistic convenience sampling. Validated questionnaires were used: a) the Utrecht Work Engagement Scale (Schaufeli et al., 2003); b) the Flow Experience Scale (Bakker, 2008); and c) the Job Satisfaction Scale SL-20/23 (Meliá & Peiró, 1998). Reliability was assessed using Cronbach’s alpha. Exploratory and confirmatory factor analyses were conducted. Data were collected and processed using SPSS, AMOS, and SEM. Both flow (0.703) and engagement (0.557) have a significant influence on the job satisfaction of volunteers, with both factors being relevant for improving job satisfaction. The state of flow is a stronger predictor than engagement. It is concluded that there is a significant and positive influence of engagement and flow on the job satisfaction of volunteers. The study of these topics confirms the importance of fostering engagement and flow among volunteers to enhance their job satisfaction
Effect of noise reduction on PLSR modeling in near infrared spectroscopy using denoising autoencoder
Get PDFIn this study, a deep learning-based denoising autoencoder approach is proposed to increase the robustness of near-infrared spectroscopy data to random noise and improve quantitative modeling accuracy. Artificial Gaussian noise at four different levels (10, 15, 20, and 25 dB) was added to the near-infrared spectra obtained from milk samples to mimic the real measurement conditions. The noisy spectra were denoised by processing with an autoencoder architecture consisting of fully connected layers. The noise removal performance is quantitatively evaluated with both theoretical and measured signal-to-noise ratio values. The results show that the AE model significantly improves the spectral signal quality at all signal-to-noise ratio levels. In particular, at the lowest signal-to-noise ratio level (10 dB), the signal-to-noise ratio value nearly tripled to 29.6 dB with the autoencoder. At all other levels, an average increase of 18-20 dB was observed in the signal-to-noise ratio of the denoised spectra. In the second stage of the study, Partial Least Squares Regression models were built using both the noisy and cleaned spectra and evaluated on the test set with root mean square error and coefficient of determination. The Partial Least Squares Regression models built with the denoised spectra achieved lower root mean square error and higher coefficient of determination values at all signal-to-noise ratio levels. Especially at the 10 dB signal-to-noise ratio level, the coefficient of determination value of the model increased from 0.44 to 0.71, while the root means square error decreased from 0.60 to 0.43. The results show that the deep learning-based AE architecture can effectively reduce random noise in near-infrared spectral data and significantly improve both spectral signal quality and quantitative modeling performance. This approach provides an effective solution to improve model reliability and accuracy in near-infrared spectroscopy analysis