KTU Open Journal Systems (Kaunas University of technology)
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Navigating Technological Change: The Role of Passive Social Policies in Central and Eastern European Labour Markets
No full textCentral and Eastern European (CEE) countries have limited research attention regarding the impact of technological change on the labour market. While existing studies offer many insights into developed countries, research on CEE countries, which have not yet achieved the level of prosperity seen in Western nations, does not take into consideration the following paradox – the existing labour force deficit and lack of technological innovation at the same time. This makes the region particularly valuable for the analysis in the context of technological change. Our study expands current theoretical understanding of the relationship between technological change and employment by examining the effects of passive labour market policies. The empirical analysis, using fixed-effects models, reveals that the overall effect of digitalization on employment is inconsistent, suggesting that the direct relationship between ICT capital and employment is not robust across specifications. This may result from the balancing of both positive and negative effects of technological change on the labour market. However, three models find a positive and statistically significant moderating effect of social protection benefits, while two showed insignificant estimates. This suggests that higher social protection can help mitigate digitalization’s negative employment effects by sustaining demand and supporting jobs in non-automated sectors
Cds Quantum Dots Composite Sol-gel Rod for Optical Applications
No full textColloidal quantum dots (QDs) based on CdS were directly incorporated into a sol to fabricate solid rods. Various characterization techniques were employed to study the properties of the composite rod. A comparison between the absorption, emission, and excitation spectra of the QDs in the solid rod and in solution revealed their significant and stable nature in the solid state. SEM image shows that QD particles are well interacted with the sol gel environment. The observed particle size of QDs was heteronomous approximately from 5 to 10 nm. The XRD pattern of QDs illustrates their crystalline nature. The significant spontaneous emission (SE) signal was enhanced from QDs composite rod under the excitation of a 355 nm Pico second laser source. These findings suggest that further improvements in the integration of QDs into sol gel rods could be achieved by employing a higher density of QDs in the solid rod. The fabrication of QDs composite rods with a high concentration holds the potential for testing stimulated or amplified spontaneous emission in future studies
Preparation and Characterization of Mesoporous Activated Carbon-Supported Tin Oxide Nanocomposites from Agro-Waste (Cyperus Corymbosus Grass Stem) and its Use as a Highly Efficient Catalyst in a Three-component Reaction
No full textThe present study reports an eco-friendly preparation of mesoporous carbon-supported tin oxide nanocomposite from agro-waste (Cyperus corymbosus grass stem). The CCSAC - SnO2 prepared by greener method successfully utilizing Cyperus corymbosus waste. The prepared CCSAC-SnO2 nanocomposite was characterized using advanced analytical techniques such as Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Raman spectroscopy, Brunauer-Emmett-Teller (BET) analysis, X-ray photoelectron spectroscopy (XPS) analysis, and Thermogravimetry Differential Thermal Analysis (TG-DTA). The amorphous and crystalline nature of Cyperus corymbosus stem-activated carbon (CCSAC) and Cyperus corymbosus activated carbon supported tin oxide nanocomposites (CCSAC-SnO2 nanocomposite) was confirmed using powder XRD analysis. FT-IR analysis was used to identify the surface functional groups attached to the CCSAC and CCASC-SnO2 nanocomposite. The element composition of CCSAC and CCSAC-SnO2 nanocomposite was confirmed by EDX analysis. BET analysis confirmed the CCSAC-SnO2 nanocomposite mesoporous nature. XPS and TG-DTA analysis confirmed the elemental composition and thermal stability of the CCSAC-SnO2 nanocomposite. The CCSAC-SnO2 nanocomposite was used as a nanocatalyst in a three-component reaction. This study highlights the potential of utilizing plant waste to prepare valuable mesoporous CCSAC-SnO2 nanocomposite, highlighting both environmental sustainability and catalytic efficiency
Research Progress on Leaching of Rare Earth Elements in Phosphogypsum
No full textWith the increasing global demand for rare earth elements and the depletion of traditional mineral resources, recycling rare earth elements from industrial solid waste has become an important direction of sustainable resource utilization. Phosphogypsum is a kind of industrial by-product with huge output and trace rare earth elements, its effective treatment and resource utilization are of great significance for environmental protection and economic development. Based on the occurrence state of rare earth elements in phosphogypsum, the research progress of leaching of rare earth elements in phosphogypsum was reviewed in this paper. The leaching mechanism and influencing factors of different leaching agents were summarized and analyzed
Silicon Carbide Nanoparticle-Enabled Strengthening of Aluminum and Copper Resistance Spot Welds
No full textResistance spot welding (RSW) is a widely employed technique for joining aluminum and copper alloys, valued for its efficiency and effectiveness. However, the mechanical properties of the resulting welds, particularly their tensile strength and resistance to deformation, often fall short of industrial demands. This study explores the incorporation of Silicon Carbide nanoparticles (SiC NPs) as a method to enhance the mechanical performance of RSW joints in aluminum and copper alloys. Experimental results demonstrate that the addition of SiC NPs significantly improves tensile strength, with gains primarily attributed to grain refinement and the formation of dispersion-strengthening mechanisms. Advanced characterization techniques, including Field Emission Scanning Electron Microscopy (FESEM) and EDS analysis, provide detailed insights into the morphological and structural transformations within the weld zones. These findings underscore the potential of SiC NPs to not only enhance the strength and durability of RSW joints but also to advance the overall quality and reliability of welding processes in aluminum and copper alloys. This research opens new avenues for the application of nanoparticle reinforcement in industrial welding, offering a pathway to achieve superior joint performance
Effect of Fiber Content and Water Absorption Behaviour on the Mechanical Properties of Screw Pine Fiber-reinforced Vinyl Ester Composites
No full textThis study examines how water exposure affects the mechanical properties of randomly oriented screw pine fiber reinforced vinyl ester composites. Composite specimens have been produced using the compression moulding process with three different fibre content values (12.75, 26.19, and 40.39 vol.%). For 5 days, the produced composite specimens were immersed in three different water environments: seawater, groundwater, and distilled water, to investigate the effect of water absorption on the mechanical properties of composites. The mechanical properties of composites under wet conditions were compared to those in dry conditions, and they were found to decrease when water particles were absorbed. In both dry and wet conditions, the composite with a volume of 26.19 % has the highest tensile, flexural, and impact strength values. Mechanical properties were drastically lowered in wet conditions compared to dry conditions. It was revealed that exposure to seawater has a significant effect on composite properties when compared to ground and distilled water exposure. The fractured surface of composite specimens was examined under a scanning electron microscope following exposure to three different water conditions. Scanning electron microscopy revealed resin losses, void formation, and microcracks on the surface of the wet composite specimens
Palm Shell Ash-based Geopolymer Mortar Innovation as a Sustainable Construction Solution
No full textThis study examines the potential use of palm shell ash, a byproduct of Indonesia\u27s palm oil industry, as an environmentally sustainable alternative to cement in geopolymer mortar. The primary objective is to improve environmental sustainability by decreasing CO2 emissions in the construction industry. The study utilizes an alkaline solution of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3), along with silica fume and a superplasticizer, to assess the influence of palm shell ash on the mechanical, physical, and chemical properties of geopolymer mortar. Fourier Transform Infrared Spectroscopy (FTIR) to analyze functional group compounds, Scanning Electron Microscopy (SEM) for microstructure examination, and X-ray diffraction (XRD) to identify crystal phases. The work uses machine learning techniques to compare actual compressive strength with predicted values, aiming to enhance the accuracy of strength predictions. Initial findings suggest that using palm shell ash into geopolymer mortar improves mechanical performance and reduces reliance on conventional cement. This underscores the potential of palm shell ash as a sustainable material in the construction sector, contributing to environmental conservation and resource preservation
Fatigue Studies on Cryogenic Treated Dissimilar FSW AA6066-T6 and AA1060-T6 Aluminium Alloys
No full textThe present research investigates the fatigue life of dissimilar friction stir welding (FSW) of AA6066-T6 and AA1060-T6 aluminium alloys that have undergone deep cryogenic treatment (DCT). The DCT-FSW alloy has fine, dense intermetallic phases, as evidenced by the microstructures of the welded zones of FSW. The uniaxial fatigue experiment was done to measure the number of cycles for failure and to plot the S-N curve. The fatigue fractures of both samples have been examined by SEM to investigate the fracture mode. Moreover, the fatigue life of the FSW and DCT-FSW joints was predicted using the Basquin method and the Acceleration Life Test (ALT). The predicted results revealed that the ALT method is more accurate than the Basquin method
Bio-based Superhydrophobic Sensor for Enhanced Anti-Fouling and Rapid Bacterial Detection in Hematology
No full textHematology patients are at high risk of nosocomial infections, necessitating rapid and reliable bacterial detection. Current methods, such as culture and polymerase chain reaction (PCR), are often slow, expensive, or susceptible to contamination. This research introduces a novel bio-based superhydrophobic sensor to address these limitations. The sensor utilizes a polydimethylsiloxane (PDMS) and TiO2 coated substrate to create a superhydrophobic surface (water contact angle >150°), which significantly reduces bacterial adhesion. Detection relies on peptides that undergo a conformational change upon binding specific bacteria, releasing attached magnetic beads. These beads are detected electrochemically using an indium tin oxide (ITO) electrode modified with cadmium telluride (CdTe) quantum dots and graphene oxide (GO) composite, enhancing electron transfer efficiency by 2.3-fold compared with bare ITO. This design achieved rapid (<90 minutes) and sensitive detection. The sensor had high accuracy comparable to PCR and discriminated between Klebsiella pneumoniae (K. pneumoniae) and Pseudomonas aeruginosa (P. aeruginosa). By combining anti-fouling properties with specific bacterial recognition and enhanced electrochemical detection, this sensor offers a promising platform for reducing infection risks in hematology
Understanding Architectural Tectonics to Prevent Extinction: an Empirical Study of Banua Layuk Mamasa, Indonesia
No full textBanua layuk architecture has distinctive characteristics that describe complex architectural tectonics in both technical and artistic aspects. Tectonics is an art in construction that presents aesthetics. Discussion of architectural tectonics in banua layuk in Mamasa has not yet been done. This study aims to reveal the architectural tectonics of banua layuk and understand the value of sustainability in banua layuk\u27s design as documentation of carpentry creativity, a wealth of Indonesian architecture that must be preserved. This study is qualitative research with a naturalistic paradigm. Data analysis was carried out by analyzing the architectural tectonics of banua layuk Mamasa, understanding the coreform and artform, and understanding the value of sustainability in banua layuk. The results of the study indicate that the tectonics of the banua layuk coreform are divided into three independent parts: the lower structure is a bar frame with a rocking construction, the middle structure is a bearing wall with a bearing wall construction, and the upper structure is a bar frame with a tie construction. While the banua layuk art form is integrated with its structural components, either in the form of artistically formed structural elements, carvings with symbolic meanings, or traditional joints that are left exposed to add to the aesthetic value of the building, these ornaments are found in the structural components of badong, paraba\u27ba, panulak, lentong and palelen as well as the roof frame. In addition, banua layuk Mamasa also has sustainable values, including environmentally friendly materials, structures, and constructions that are by geographical conditions, and the use of ornaments as a cultural identity that can be used in its original form or developed with a new design that is more by changing times