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  • Study of Nanohydroxyapatite Coatings Prepared by the Electrophoretic Deposition Method at Various Voltage and Time Parameters
    • Klaudia Malisz
    • Beata Świeczko-Żurek
    • Jean Marc Olive
    • Grzegorz Gajowiec
    • Gilles Pecastaings
    • Aleksandra Laska
    • Alina Sionkowska
    2024 Pełny tekst Materials

    The aim of the work is to compare the properties of nanohydroxyapatite coatings obtained using the electrophoretic deposition method (EDP) at 10 V, 20 V, and 30 V, and with deposit times of 2 and 5 min. The primary sedimentation was used to minimize the risk of the formation of particle agglomerates on the sample surface. Evaluation of the coating was performed by using a Scanning Electron Microscope (SEM), Energy-Dispersive Spectroscopy (EDS), Atomic Force Microscopy (AFM), optical profilometer, drop shape analyzer, and a nanoscratch tester. All of the coatings are homogeneous without any agglomerates. When low voltage (10 V) was used, the coatings were uniform and continuous regardless of the deposition time. The increase in voltage resulted in the formation of cracks in the coatings. The wettability test shows the hydrophilic behavior of the coatings and the mean contact angle values are in the range of 20–37° . The coatings showed excellent adhesion to the substrate. The application of a maximum force of 400 mN did not cause delamination in most coatings. It is concluded that the optimal coating for orthopedic implants (such as hip joint implants, knee joint implants or facial elements) is obtained at 10 V and 5 min because of its homogeneity, and a contact angle that promotes osseointegration and great adhesion to the substrate.

  • Study of the optical rotatory of potassium titanyl phosphate using the advanced dual-wavelength polarimetric method
    • Mykola Shopa
    • Nazar Ftomyn
    • Yaroslav Shopa
    2024 Pełny tekst OPTO-ELECTRONICS REVIEW

    A dual-wavelength high-accuracy universal polarimeter was applied to the circular birefringence and optical activity measurement in potassium titanyl phosphate (KTP) nonlinear crystal. The experimental setup used two single-mode He-Ne lasers with close wavelengths of 594 and 633 nm as light sources. Measurement has been carried out for two crystal settings in directions of a 45-degree relative angle to the [100] and [010] crystallographic axes. Multiple light reflections inside the crystal sample were considered when processing the results of the polarimetric measurements. The results have been analysed using the optical transmission function for the polariser-sample-analyser system, and 2D intensity contour maps made it possible to determine the phase parameters, systematic errors, and eigenwaves ellipticity. It was found that the gyration tensor component of the KTP crystal is equal to g12 = 1.4 ⋅10−5 which in terms of optical rotatory power corresponds to the very small magnitude of the rotation value of 2.3 deg/mm

  • Study on extraction and characterization of anchote (Coccinia abyssinica) starch and reinforced enset (Ensete ventricosum) fiber for the production of reinforced bioplastic film
    • Samuel Latebo Majamo
    • Temesgen Amibo
    2024 Pełny tekst Heliyon

    Population expansion is causing an increase in dependence on plastic materials. The worst aspects of conventional plastics were their inability to biodegrade, their poor capacity to transmit water vapor, and their production of greenhouse gases. Usages of bioplastics are necessary for the advancement of a green economy and environment in order to eradicate these drawbacks of traditional plastics. In this study, reinforced bioplastic film was produced from anchote (Coccinia Abyssinica) starch and enset (Ensete Ventricosum) fiber. Starch from anchote was extracted and its properties were characterized via adequate techniques. The maximum carbohydrate content (86.26 ± 0.25%w/w) of anchote starch indicates that it is suitable feedstock for plastic film production. In addition, extracted starch was characterized by SEM, FTIR, TGA and XRD. The reinforcing material enset fiber was extracted and characterized by FTIR and XRD. The results of both feedstock materials exhibited the good characteristics and viability for bioplastic film pro- duction. Enset fiber loadings used were 0 %, 4 %, 8 %, 12 % and 16 % w/w in starch basis. Tensile strength, elongation, thickness, moisture content, transparency, solubility and density of pro- duced bioplastic were determined. Tensile force grew and elongation reduced as fiber loading rose up to 8 %. The tensile strength gradually declined with increasing fiber loading. Additionally, the created bioplastic film’s groups of functions and chemical bonds were examined. In com- parison to unreinforced plastic film, the results showed that the reinforced bioplastic film used in this study was an excellent and effective product.

  • Study on the wear characteristics of a 3D printed tool in flat lapping of Al2O3 ceramic materials
    • Mariusz Deja
    • Dawid Zieliński
    • Sisay Workineh Agebo
    2024 Pełny tekst WEAR

    Widespread and popular use of ceramic products in various industry sectors necessitates the search for methods of their efficient processing. Lapping technology, which enables obtaining high dimensional and shape accuracy and high surface flatness, is one of the basic methods of finishing hard and brittle technical ceramics with a porous structure. This study analyzed the characteristics and wear value of an SLS-printed abrasive tool intended for single-sided lapping of Al2O3 technical ceramics. As earlier research demonstrated, introduction of a 3D printed lapping plate by selective laser sintering (SLS), leads to a significant development in the field of precision machining technology. This method showed not only efficient machining performance on oxide technical materials, but was also characterized by relatively low abrasive wear. Straightness errors were evaluated with the use of a least-squares method (LSQ) and minimum zone method based on control line rotation scheme (CLRS). The proposed model proved the experimental results by identifying a similar location of a higher contact density on the lapping tool, where this location is expected to be the one for bigger wear. Surface topography of the lapping tool depends on the tool wear intensity and as a consequence on its shape error. An SLS-printed lapping plate, by obtaining good technological effects, revealed its potential ability in machining hard and brittle technical ceramics.

  • Study the impact of design method preference on the usefulness of concrete and on CO2 emissions
    • Salem Abdelgader
    • Marzena Kurpińska
    • Hakim S. Abdelgader
    • Farzam Omidi Moaf
    • Mugahed Amran
    2024 International Journal of Building Pathology and Adaptation

    Purpose – The research investigates the impact of concrete design methods on performance, emphasizing environmental sustainability. The study compares the modified Bolomey method and Abrams’ law in designing concretes. Significant differences in cement consumption and subsequent CO2 emissions are revealed. The research advocates for a comprehensive life cycle assessment, considering factors like compressive strength, carbonation resistance, CO2 emissions, and cost. The analysis underscores the importance of evaluating concrete not solely based on strength but also environmental impact. The study concludes that a multicriteria approach, considering the entire life cycle, is essential for sustainable concrete design, addressing durability, environmental concerns, and economic factors. Design/methodology/approach – The study employed a comprehensive design and methodology approach, involving the formulation and testing of 20 mixed concretes with strengths ranging from 25 MPa to 45 MPa. Two distinct design methods, the modified Bolomey method (three equations method) and Abrams’ law, were utilized to calculate concrete compositions. Laboratory experiments were conducted to validate the computational models, and subsequent analyses focused on assessing differences in cement consumption, compressive strength, CO2 emissions, and concrete resistance to carbonation. The research adopted a multidisciplinary perspective, integrating theoretical analysis, laboratory testing, and life cycle assessment to evaluate concrete performance and sustainability.

  • Stymulacyjna funkcja podatku dochodowego
    • Piotr Kasprzak
    2024

    W opracowaniu podjęto próbę opisania i usystematyzowania wiedzy na temat systemu ulg i zwolnień podatkowych stosowanych w Polsce. Autor przedstawia m.in. historię i ewolucję systemu podatkowego w Polsce, począwszy od roku 1989, tłumacząc przy tym rolę państwa. Omówione zostały też trendy i kierunki rozwoju podatków dochodowych. W książce znajdują się informacje na temat istoty i funkcji podatków, ze szczególnym uwzględnieniem stymulacyjnej funkcji podatków. W pracy omówiono również teorię dotyczącą podatków dochodowych od osób fizycznych i prawnych. Autor wymienia i objaśnia stosowane w praktyce ulgi i zwolnienia w podatku dochodowym dla osób fizycznych i prawnych. W opracowaniu przedstawiono analizę pojęć systemu gospodarczego, podatku dochodowego, preferencji podatkowych. Przeprowadzono także analizę sposobów stymulacji zachowań przedsiębiorców w kontekście mechanizmów makroekonomicznych, w tym automatycznych stabilizatorów koniunktury w postaci ulg i zwolnień. Niniejsza książka jest kolejną pozycją, która powstała na podstawie rozprawy doktorskiej autora. Tym razem skupiono się jednak na teoretycznej stronie systemu preferencji podatkowych w systemie gospodarczym.

  • Subjective quality evaluation of 8- and 10-bit MP4-coded video sequences from Netflix
    • Przemysław Falkowski-Gilski
    • Tadeus Uhl
    • Parameshachari Bidare Divakarachari
    2024 Zeszyty Naukowe Akademii Morskiej w Szczecinie

    Recently, many researchers have been intensively conducting quality of service (QoS), quality of experience (QoE), and user experience (UX) studies in the field of video analysis. This paper is intended to make a new, complementary contribution to this field. Currently, streaming platforms are key products in relation to delivering video content online. Most often, they include the MP4 video format, which is most widely utilized among audio-visual codecs. This study involves a group of 38 individuals, aged between 21–35 years old, in a laboratory consisting of 20 iMacs with 4K retina display. The presented signal sequences included content sourced from the Netflix Chimera repository, with 8- and 10-bit depth, available in different resolutions of 270p, 432p, 720p, and 1080p. Tests included a subjective quality evaluation in a 5-step mean opinion score (MOS) scale, focused on the UX aspect. According to the obtained results, content with the lowest and highest resolutions is optimal in 8-bit depth, while movies with intermediate resolutions are better in 10-bit depth. For 8-bit content, the main problem is pixelation, whereas, in the case of 10-bit samples, the main issue is color noise, particularly in the case of the lowest resolution. Many viewers indicated that 10-bit encoding offered lower quality. Moreover, 8-bit movies caused a lower quality of the gradient, presumably due to the smaller range of the available color. However, 8-bit movies in the same situation generate visible stripes on static images in the background, causing a lower quality of the gradient, which is probably due to the smaller range of available colors. The results of the performed experiments may be of particular interest to content creators and distributors, particularly network and cable operators, as well as wireless and wired providers.

  • Substrate Integrated Waveguide-Based Frequency-Tunable Self-Octaplexing Antenna
    • Nrusingha Charan Pradhan
    • Sławomir Kozieł
    • Karthikeyan Sholampettai Subramanian
    2024 AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS

    This communication presents the first-ever substrate integrated waveguide (SIW)-based frequency-tunable self-octaplexing antenna (SOA) for wireless communication. The structure is arranged by implementing eight distinct patches with planar 50-ohm feedlines at the top of the SIW cavity, which realize eight distinct resonant frequencies. Independent tuning of each resonant frequency is achieved by incorporating appropriately allocated pockets in the antenna substrate, which can be filled with solid dielectrics of dierent permittivity. The obtained tuning range is broad, from 4.76 GHz to 9.82 GHz, with the capability of tuning each port individually. Furthermore, the port isolation (for all ports) that is better than 20.5 dB. The proposed antenna has a realized gain of 3.91, 3.2, 4.05, 4.14, 3.8, 3.37, 3.55 and 3.28 dBi when using Rogers RT-6010 for pocket filling. Furthermore, the antenna provides stable radiation characteristics with precise tuning. The proposed device is suitable for various applications, including multi-standard wireless communications, due to its small size, wide tuning range, consistent radiation patterns, and comparable isolation levels.

  • Substrate Integrated Waveguide-Based Ultra-Compact Self-Heptaplexing Antenna for IoT Connectivity
    • Nrusingha Charan Pradhan
    • Sławomir Kozieł
    • Karthikeyan Sholampettai Subramanian
    2024 AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS

    This paper introduces an innovative design of a substrate-integrated waveguide (SIW)-based self-heptaplexing antenna (SHA). The proposed structure is implemented using a combination of circular and rectangular HM-SIW cavities. Furthermore, the antenna contains seven individual patches on top of the SIW cavity to operate at seven distinct frequencies. The microstrip feeding technique has been used to activate seven distinct ports. All patches are excited through 50-ohm feedlines. The antenna operation is elucidated using an equivalent LC model. To demonstrate its operating principles a self-heptaplexing antenna has been designed to work at 2.45, 3, 3.58, 4, 4.45, 5.2, and 5.88 GHz. The measured realized gain of the proposed antenna at the respective bands is 3.2, 3.85, 3.1, 3.245, 4, 2.98, and 4.5 dBi. The isolation exceeds 20 dB over the entire working bands. The EM-simulated and measured characteristics are in good agreement. Although the suggested antenna has been designed for seven ports and lower frequencies, it has a relatively compact size of 0.28 2g. The major advantages of the proposed self-heptaplexing antenna include excellent isolation, an ultra-compact design, and good radiation characteristics. The proposed antenna offers a high degree of flexibility. It allows for independent frequency tuning, which makes it suitable for IoT, wireless communication systems, and diverse sub-6 GHz band applications.

  • Suitability of acoustic power amplifiers as power amplifiers in underwater communication systems
    • Aleksander Schmidt
    • Jan Schmidt
    • Iwona Kochańska
    2024 Pełny tekst International Journal of Electronics and Telecommunications

    The paper presents selected acoustic power amplifiers from among those currently available. The results of a series of measurements characterising the amplifiers are presented. The measured amplitude and phase characteristics as a function of frequency for four selected amplifiers are analysed. The spectra of the output signal in the band from 4 kHz to 30 kHz are presented. The usefulness of the selected amplifiers in an underwater communication system is assessed.

  • Sulfur cycle, a new opportunity for nitrogen removal from textile wastewater: A review
    • Shiyi Zhao
    • Hong Chen
    • Jun Sheng
    • Xin Yu
    • Kejia Zeng
    • Dong Cheng
    • Hanyue Wu
    • Ruiting Zhang
    • Xianbao Xu
    • Xiaoming Zou
    • Gang Xue
    2024 Journal of Water Process Engineering

    The problem of nitrogen removal from textile wastewater (TW) has plagued for quite a long time. Traditional biological nitrogen removal technology is limited by the complex water quality characteristics, and high concentration of sulfate (over 5000 mg/L) further aggravates its difficulty. After analyzing source and characteristics of nitrogen and sulfur in TW, using miraculous sulfur cycle caused by the existing sulfate to solve the problem of nitrogen removal seems to be a viable option. This review mainly elaborated the heterotrophic sulfate reduction combining with dye removal, which achieved >90 % sulfate reduction and almost complete dye removal, as well as sulfur-driven autotrophic denitrification, with over 85 % total nitrogen removal. The crucial bacteria and key parameters affecting sulfur cycle were summarized. Based on the characteristics of abundant sulfur and nitrogen in TW, the feasibility of relying on sulfur cycle to achieve nitrogen removal in TW is discussed in detail. Furthermore, the sulfur and nitrogen coupled processes, including sulfate reduction, autotrophic denitrification and nitrification integrated process (SANI) and Sulfammox are reviewed. Technology based on sulfur cycle has the advantages of low energy consumption and low sludge production (reduce by 90 %), as well as cutting greenhouse gas emissions (decrease by 90 %). In the context of carbon peaking and carbon neutrality goals, TW treatment based on sulfur cycle is an energy-saving and carbon-reduction technology with development potential.

  • Summary of the 27th IAHR International Symposium on Ice
    • Wojciech Artichowicz
    • Parisa Radan
    • Tomasz Kolerski
    2024 Pełny tekst

    The 27th IAHR International Symposium on Ice, held in Gdańsk, Poland, between 9 and 13 June 2024, gathered 153 scientists and industry professionals from 14 countries. Organized by Gdańsk University of Technology, the event focused on key global ice-related challenges, including ice mechanics, ice-structure interactions, climate change impacts on the cryosphere, and offshore wind development in the Baltic Sea. With 93 papers in the published conference proceedings, the symposium showcased diverse methodologies and multidisciplinary research on sea and river ice dynamics, as well as engineering challenges in cold regions. The event fostered engaging discussions and facilitated collaboration, reinforcing its role as a leading platform for advancing ice research. In this paper this event is summarized.

  • Superconductivity–Electron Count Relationship in Heusler Phases─the Case of LiPd2Si
    • Karolina Górnicka
    • Xin Gui
    • Juan Chamorro
    • Tyrel McQueen
    • Robert J. Cava
    • Tomasz Klimczuk
    • Michał Winiarski
    2024 Pełny tekst CHEMISTRY OF MATERIALS

    We report superconductivity in the full Heusler compound LiPd2Si (space group Fm3̅m, No. 225) at a critical temperature of Tc = 1.3 K and a normalized heat capacity jump at Tc, ΔC/γTc = 1.1. The low-temperature isothermal magnetization curves imply type-I superconductivity, as previously observed in LiPd2Ge. We show, based on density functional theory calculations and using the molecular orbital theory approach, that while LiPd2Si and LiPd2Ge share the Pd cubic cage motif that is found in most of the reported Heusler superconductors, they show distinctive features in the electronic structure. This is due to the fact that Li occupies the site which, in other compounds, is filled with an early transition metal or a rare-earth metal. Thus, while a simple valence electron count–property relationship is useful in predicting and tuning Heusler materials, inclusion of the symmetry of interacting frontier orbitals is also necessary for the best understanding.

  • Support Materials of Organic and Inorganic Origin as Platforms for Horseradish Peroxidase Immobilization: Comparison Study for High Stability and Activity Recovery
    • Muhammad Bilal
    • Oliwia Degorska
    • Daria Szada
    • Agnieszka Rybarczyk
    • Agata Zdarta
    • Michał Kaplon
    • Jakub Zdarta
    • Teofil Jesionowski
    2024 Pełny tekst MOLECULES

    In the presented study, a variety of hybrid and single nanomaterials of various origins were tested as novel platforms for horseradish peroxidase immobilization. A thorough characterization was performed to establish the suitability of the support materials for immobilization, as well as the activity and stability retention of the biocatalysts, which were analyzed and discussed. The physicochemical characterization of the obtained systems proved successful enzyme deposition on all the presented materials. The immobilization of horseradish peroxidase on all the tested supports occurred with an efficiency above 70%. However, for multi-walled carbon nanotubes and hybrids made of chitosan, magnetic nanoparticles, and selenium ions, it reached up to 90%. For these materials, the immobilization yield exceeded 80%, resulting in high amounts of immobilized enzymes. The produced system showed the same optimal pH and temperature conditions as free enzymes; however, over a wider range of conditions, the immobilized enzymes showed activity of over 50%. Finally, a reusability study and storage stability tests showed that horseradish peroxidase immobilized on a hybrid made of chitosan, magnetic nanoparticles, and selenium ions retained around 80% of its initial activity after 10 repeated catalytic cycles and after 20 days of storage. Of all the tested materials, the most favorable for immobilization was the above-mentioned chitosan-based hybrid material. The selenium additive present in the discussed material gives it supplementary properties that increase the immobilization yield of the enzyme and improve enzyme stability. The obtained results confirm the applicability of these nanomaterials as useful platforms for enzyme immobilization in the contemplation of the structural stability of an enzyme and the high catalytic activity of fabricated biocatalysts.

  • Surface finite viscoelasticity and surface anti-plane waves
    • Victor Eremeev
    2024 Pełny tekst INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE

    We introduce the surface viscoelasticity under finite deformations. The theory is straightforward generalization of the Gurtin–Murdoch model to materials with fading memory. Surface viscoelasticity may reflect some surface related creep/stress relaxation phenomena observed at small scales. Discussed model could also describe thin inelastic coatings or thin interfacial layers. The constitutive equations for surface stresses are proposed. As an example we discuss propagation shear (anti-plane) waves in media with surface stresses taking into account viscoelastic effects. Here we analysed surface waves in an elastic half-space with viscoelastic coatings. Dispersion relations were derived.

  • Surprising Radiolytic Stability of 8‑Thiomethyladenine in an Aqueous Solution
    • Magdalena Datta
    • Adrian Szczyrba
    • Magdalena Zdrowowicz
    • Dariusz Wyrzykowski
    • Olga Ciupak
    • Sebastian Demkowicz
    • Farhad Izadi
    • Stephan Denifl
    • Janusz Rak
    2024 Pełny tekst JOURNAL OF PHYSICAL CHEMISTRY B

    8-Thiomethyladenine (ASCH3), a potentially radiosensitizing modified nucleobase, has been synthesized in a reaction between 8-thioadenine and methyl iodide. Despite favorable dissociative electron attachment (DEA) characteristics, the radiolysis of an aqueous solution of ASCH3 with a dose of X-ray amounting to as much as 300 Gy leads to no effects. Nevertheless, crossed electron-molecule beam experiments in the gas phase on ASCH3 confirm the theoretical findings regarding the stability of its radical anion, namely, the most abundant reaction channel is related to the dissociation of the S-CH3 bond in the respective anion. Furthermore, electroninduced degradation of ASCH3 has been observed in aprotic acetonitrile, which is strong evidence for the involvement of proton transfer (PT) in stabilizing the radical anion in an aqueous solution. These findings demonstrate that PT in water can be the main player in deciding the radiosensitizing properties of modified nucleobases/nucleosides.

  • Survey of ICT students' views on self-assessment of professional preparation after remote study
    • Marta Szczerska
    • Michał Tomczak
    • Paweł Ziemiański
    • Katarzyna Wajszczyk
    2024 Edukacja Ustawiczna Dorosłych

    The contemporary post-pandemic reality is characterised by an undisputable shift toward remote education and work. The aim of this article is to identify the assessment of ICT evaluation of different forms of study, including desktop, remote and hybrid forms; to find out their preferences towards different forms of education and work, and to determine their sense of self-efficacy in terms of professional tasks undertaken after remote education. A survey method was used and the research sample was based on purposive sampling. The results indicate that, although a hybrid environment is preferred in both educational and professional contexts, the challenge remains to optimise this format in order to improve the quality of education. Nevertheless, the surveyed students feel self-efficacious in their professional activities after remote education.

  • Suspension and process parameters selection for electrophoretic deposition of Mn–Co spinel coating on steel interconnects
    • Omid Ekhlasiosgouei
    • Federico Smeacetto
    • Sebastian Molin
    2024 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

    Metallic interconnect coatings, consisting of MnCo2O4 spinel, were effectively applied to Crofer 22 APU using the electrophoretic deposition (EPD) method in both H2O: ethanol and pure ethanol solvents. The primary goal of this method was to prevent chromium migration, minimize evaporation, and control the oxidation rate. The study aimed to assess the quality, adhesion, and thickness of the Mn–Co coating, with the objective of achieving a consistent and uniform layer. The results indicated a preference for pure ethanol solvent over H2O: ethanol (40:60 %Vol) for Mn–Co particles. Furthermore, the agglomeration of Mn–Co particles was notably lower (approximately 7 times) in ethanol compared to H2O: ethanol. The morphology and surface roughness of the sintered Mn–Co coating on the alloy were examined using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). A uniform and dense coating was successfully attained using pure ethanol solvent at a solid concentration of 10 g/L, with 0.5 g/L of iodine serving as a disperser. The deposition process, carried out at a voltage of 30V for 20 s, resulted in a coating with a thickness of 7.4 ± 0.3 μm and a surface roughness of 0.75 ± 0.5 μm.

  • Sustainable chemically modified poly(butylene adipate-co-terephthalate)/thermoplastic starch/poly(ε-caprolactone)/cellulose biocomposites: looking at the bulk through the surface
    • Aleksander Hejna
    • Mateusz Barczewski
    • Paulina Kosmela
    • Olga Mysiukiewicz
    • Agnieszka Tercjak
    • Adam Piasecki
    • Mohammad Saeb
    • Marek Szostak
    2024 JOURNAL OF MATERIALS SCIENCE

    Sustainable polymer composites (or biocomposites) based on renewable and green polymers are progressively under development in a technological paradigm shift from “just use more and more” to “convert into value-added products”. Therefore, significant efforts should focus not only on their reduced environmental impact but also on maximizing their performance and broadening their application range. Herein, the bio-based blends based on Mater-Bi bio-plastic and poly(ε-caprolactone), at a weight ratio of 70:30, were developed, followed by the addition of UFC100 cellulose filler to yield sustainable biocomposites. The effects of cellulose chemical modification with three diisocyanates, i.e., hexamethylene diisocyanate (HDI), methylene diphenyl isocyanate (MDI), or toluene diisocyanate (TDI) on the surface properties of biocomposites were evaluated by water contact angle and surface roughness detected by atomic force microscopy (AFM). Biocomposites containing cellulose modified with HDI, MDI, or TDI revealed contact angle values of 93.5°, 97.7°, and 92.4°, respectively, compared to 88.5° for reference blend, indicating an enlarged hydrophobicity window. This action was further confirmed by increased fracture surface roughness and miscibility detected by microscopic observation (scanning electron microscopy (SEM) and AFM). An in-depth oscillatory rheological evaluation has identified MDI, followed by TDI, as the most efficient compatibilizer of the analyzed system. Correspondingly, thermogravimetric analysis and differential scanning calorimetry analyses showed more residue and higher melting temperatures for biocomposites, more promisingly with MDI and TDI modifiers. In conclusion, either incorporation or diisocyanate modification of cellulose affects both surface and bulk properties, providing vital insights into future developments in the field. Proper selection of diisocyanate modifier of cellulose may enable engineering of composites performance.

  • Sustainable energy consumption – Empirical evidence of a household in Poland
    • Ewelina Sokołowska
    • Jerzy Wiśniewski
    2024 Pełny tekst Energy Strategy Reviews

    There is an expected increase in the demand for electricity from households in European countries. The outcome of the growing proportion of renewable energy sources in the energy supply mix should result in improved customer awareness regarding their electricity usage. Additionally, they must assume a more proactive role in overseeing their electricity usage. Innovation and pollution management have become crucial catalysts for promoting sustainable economic development and environmental protection. This is a response to the increasing threats posed by climate change. This study addresses this existing research gap in sustainable energy consumption. The research aims to examine the advantages of replacing traditional sources of heating with renewable ones. The empirical case study of households in Poland serves as an illustration of the theoretical foundation. The purpose of the study entails the construction of a multi-equation econometric model describing the mechanisms of electricity consumption in a specific household. The model hypothesis indicates that the model should take the form of a system of interdependent equations. The following will be described: the monthly volume of electricity consumption, the cost of this energy payment (in PLN), and the price per one MWh in a given month. Monthly time series from September 2015 to June 2023 were used. The resulting time series amounted to a count of 94 statistical observations. The results in the form of a multi-level empirical econometric model indicate that the economic, environmental, and social benefits of using renewable sources of heating can make a significant contribution to reducing fossil fuel consumption and CO2 emissions. In the context of growing environmental awareness and the need to reduce greenhouse gas emissions, heat pumps are becoming an increasingly important element in the discussion of the future of heating. Their role in transforming the energy sector in the direction of sustainability is crucial.