2024 - Repozytorium publikacji - Politechnika Gdańska

Pokaż publikacje z roku

Publikacje z roku 2024

Pokaż wszystkie

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 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 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.
Substrate Integrated Waveguide-Based Frequency-Tunable Self-Octaplexing Antenna
- Nrusingha Pradhan
- Sławomir Kozieł
- Karthikeyan 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.
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.
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 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.
Sustainable Management of Food Wastes Through Cavitation-Assisted Conversion into Value-Added Products
- Zahra Askarniya
- Xun Sun
- Chongqing Wang
- Grzegorz Boczkaj
2024
More than 30% of worldwide food consumption is thrown out as food wastes causing serious environmental, economic, and social problems. Therefore, it is required to develop sustainable food waste management methods leading to an enhancement in social and economic benefits and mitigation of environmental impacts. Anaerobic digestion can be regarded as one of those effective methods that can be employed for the conversion of food waste to value-added products. Food wastes are normally resistant towards hydrolysis (the first stage of anaerobic digestion), leading to a reduction in the formation of desired products. Cavitation is one of the useful pretreatment methods that can mitigate this problem and also increase mass transfer, which is a severe barrier to the reaction producing biodiesel (transesterification), leading to high rates of hydrolysis and transesterification. Cavitation is the formation, growth, and collapse of bubbles formed in the solution. Considering the subsequent effect of the collapse of generated bubbles (ability to disintegrate solid material, turbulence, high temperature and pressure, and radical formation), cavitation can be considered an efficient technique for minimizing the time and optimizing the generation of valuable products from food wastes. This technology can cause microbes to easily access substrates, resulting in an enhancement in microbial growth and the formation of products. Additionally, it can increase mass transfer between reactants, decreasing the time required in transesterification for producing biodiesel.
Synergism of floated paperboard sludge cake /sewage sludge for maximizing biomethane yield and biochar recovery from digestate: A step towards circular economy
- Rania H. Hafez
- Ahmed Tawfik
- Gamal K. Hassan
- Magdy Zahran
- Ahmed A. Younes
- Aleksandra Ziembińska-Buczyńska
- Filip Gamoń
- Mahmoud Nasr
2024 CHEMOSPHERE
Anaerobic digestion of floated paperboard sludge (PS) cake suffers from volatile fatty acids (VFAs) accumulation, nutrient unbalanced condition, and generation of digestate with a risk of secondary pollution. To overcome these drawbacks, sewage sludge (SS) was added to PS cake for biogas recovery improvement under a co-digestion process followed by the thermal treatment of solid fraction of digestate for biochar production. Batch experimental assays were conducted at different SS:PS mixing ratios of 70:30, 50:50, 30:70, and 20:80 (w/w), and their anaerobic co-digestion performances were compared to the mono-digestion systems at 35±0.2 °C for 45 days. The highest methane yield (MY) of 241.68±14.81 mL/g CODremoved was obtained at the optimum SS:PS ratio of 50:50 (w/w). This experimental condition was accompanied by protein, carbohydrate, and VFA conversion efficiencies of 47.3±3.2%, 46.8±3.2%, and 56.3±3.8%, respectively. The synergistic effect of SS and PS cake encouraged the dominance of Bacteroidota (23.19%), Proteobacteria (49.65%), Patescibacteria (8.12%), and Acidovorax (12.60%) responsible for hydrolyzing the complex organic compounds and converting the VFAs into biomethane. Further, the solid fraction of digestate was subjected to thermal treatment at a temperature of 500 °C for 2.0 h, under an oxygen-limited condition. The obtained biochar had a yield of 0.48 g/g dry digestate, and its oxygen-to-carbon (O/C), carbon-to-nitrogen (C/N), and carbon-to-phosphorous (C/P) ratios were 0.55, 10.23, and 16.42, respectively. A combined anaerobic co-digestion/pyrolysis system (capacity 50 m3/d) was designed based on the COD mass balance experimental data and biogenic CO2 market price of 22 USD/ton. This project could earn profits from biogas (12565 USD/yr), biochar (6641 USD/yr), carbon credit (8014 USD/yr), and COD shadow price (6932 USD/yr). The proposed project could maintain a payback period of 6.60 yr. However, further studies are required to determine the associated life cycle cost model that is useful to validate the batch experiment assumptions.
Synergistic effects of a swirl generator and MXene/ water nanofluids used in a heat exchanger pipe of a negative CO2 emission gas power plant
- Milad Amiri
- Paweł Ziółkowski
- Dariusz Mikielewicz
2024 NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
focus on optimizing heat exchangers contributes to improved temperature control mechanisms, ensuring the sustainable operation of innovative power plants working towards negative CO2 emissions. In the realm of oxy-combustion within Negative CO2 Emission Power Plants (nCO2PP), the temperature of combustion products surpasses 3000 (K). Addressing this challenge, the imperative arises to reduce these elevated temperatures to a manageable 1100(°C). This critical cooling process is achieved through the injection of water, facilitated by the implementation of heat exchangers. The study delves into the optimization of heat transfer within the heat exchanger pipe, specifically tailored for the context of a Negative CO2 Emission Power Plant. Employing a numerical simulation, the investigation explores the impact of vortex generator geometry, vane angles, single and dual propeller-type swirl generators, and the integration of a novel class of fluid, MXene/water nanofluid. Initially, the study scrutinizes propeller-type geometry at vane angles spanning from 15 to 60 degrees. The enhanced swirl flow associated with lower vane angles leads to improved fluid mixing, fostering more effective heat transfer. Results showed that the 15-degree vane angle, with a wider circumferential coverage, may result in increased wall contact, influencing heat transfer efficiency. Subsequently, at Re=6000, incremental rates of the Nusselt number ((〖Nu〗_n-〖Nu〗_s)/〖Nu〗_s %), for θ=15, 30, 45, and 60 degrees are 175.1%, 108.8%, 90.7%, and 40.3%, respectively. Also, the increment rates of Friction Factor (f_n/f_s ) for aforementioned vane angle are 38.48%, 9.26%, 4.08%, and 2.42%, respectively. In addition, for ∅_MXene=0.5 %, the Nusselt number experiences considerable increments of 22.94%, 24.17%, 24.70%, and 24.707% at Reynolds numbers of 6000, 12000, 18000, and 24000, respectively, compared to pure water, emphasizing the potential of MXene to enhance heat transfer efficiency.
Synteza i charakterystyka „zielonych” mieszanin polimerowych na bazie biopochodnego termoplastycznego poliuretanu i octanomaślanu celulozy
- Ewa Głowińska
- Joanna Smorawska
- Joanna Niesiobędzka
- Julia Grocholska
- Janusz Datta
2024 Przemysł Chemiczny
Otrzymano mieszaniny polimerowe z biopochodnego termoplastycznego poliuretanu (TPU) i dostępnego handlowo octanomaślanu celulozy (CAB), stosowanego w ilości 0–20%. TPU syntezowano metodą prepolimerową z wykorzystaniem biopoliolu, glikolu 1,3-propylenowego i diizocyjanianu heksametylenu. Materiały poddano analizie pod kątem struktury chemicznej (FTIR), właściwości termicznych (TGA, DSC) i właściwości termomechanicznych (DMTA).
Synteza małocząsteczkowych pochodnych 2-pirydonu wykazujących właściwości przeciwnowotworowe oraz przeciwbakteryjne
- Małgorzata Ryczkowska
2024 Pełny tekst
Tematyka i cel badawczy niniejszej rozprawy doktorskiej dotyczy syntezy chemicznej związków heterocyklicznych z grupy 2-pirydonu wykazujących potencjał przeciwbakteryjny oraz przeciwnowotworowy. W części teoretycznej podjęto tematykę znanych fluorochinolonów oraz chinolonów wykazujących aktywność przeciwnowotworową. Dodatkowo przedstawiono nowe metody syntezy chinolonów niewymagające stosowania katalizatorów metali przejściowych oraz opublikowane na przestrzeni ostatnich 15 lat. W części badań własnych przedstawiono syntezę arylokarbamoilowych pochodnych 4-fenylo-5,6,7,8-tetrahydrochinolin-2(1H)-onu oraz badania mające na celu poznanie mechanizmu demetylowania podczas acylowania 2-metoksy-5,6,7,8-tetrahydrochinolin-8-olu izocyjanianami fenylowymi. Przedstawiono w niej również syntezę 4-fenylo-5,6,7,8-tetrahydrochinolin-2(1H)-onów modyfikowanych w pozycji 3 podstawnikami typu benzylowego. Ponadto opisano nową metodę syntezy typu „one-pot” rdzeni 4-fenylo-5,6,7,8-tetrahydrochinolin-2(1H)-onu, zbadano mechanizm powstawania trójcyklicznych pochodnych oraz przedstawiono funkcjonalizację pilicydu grupami o charakterze hydrofilowym. W części eksperymentalnej przedstawiono procedury syntezy oraz analizę spektralną wszystkich otrzymanych związków.
Synthesis, characterization and application of cross-linked functional terpolymer through epoxy group as sorbent for extraction of cadmium from waters and foods: Multivariate optimization
- Ersen Yılmaz
- Ali Boztuğ
- Hameed Haq
- Grzegorz Boczkaj
- Nail Altunay
2024 FOOD CHEMISTRY
The purpose of this study was to develop a selective sorbent for cadmium ions (Cd(II)) enrichment in orbital shaker assisted solid phase microextraction (OS-SPME) from different aqueous and food samples. A maleic anhydride-styrene-glycidyl methacrylate (MA-St-GMA) terpolymer was synthesized and characterized in detail. Experimental variables of sample preparation step were optimized using a central composite design (CCD). The final determination step was performed using flame atomic absorption spectroscopy (FAAS). The MA-St-GMA sorbent exhibited a high adsorption capacity (195.9 mg g−1) for the Cd(II) ion. The developed method under optimal conditions provides satisfactory performance and a significant improvement compared to other protocols available in the literature. The linear range and detection limit of the method is 0.1–130 ng mL−1 and 0.03 ng mL−1, respectively. The robustness, intraday/interday precision, selectivity, and accuracy of the method were investigated. To further validate the method, a dedicated series of analysis was performed using certified reference materials (CRMs). This part of the study confirmed the applicability of the method for routine analysis. The OS-SPME-FAAS method was validated using water and food samples. Relative standard deviations and recovery for real-world samples were in ranges 1.7–2.2 % and 95.5–98.5 %, respectively. As a result, the MA-St-GMA sorbent showed that it could quantitatively extract Cd(II) ions from aqueous solution.
Synthesis of Trehalose by the Erythritol-Producing Yeast Yarrowia lipolytica Co-Displaying Maltooligosyltrehalose Synthase and Maltooligosyltrehalose Trehalohydrolase
- Shuo Xu
- Yawen Zou
- Liyun Ji
- Muhammad Bilal
- Hairong Cheng
2024 ACS Sustainable Chemistry & Engineering
Industrial trehalose production faces economic challenges with costly enzyme preparations, prompting the exploration of eco-friendly alternatives. Here, we established a coupled functional sugar production line leveraging erythritolproducing cells as an innovative enzyme preparation for trehalose synthesis. The erythritol-producing Yarrowia lipolytica was modified to express a fusion protein consisting of maltooligosyltrehalose synthase and maltooligosyltrehalose trehalohydrolase from Sulfolobus solfataricus ATCC35092. The engineered strain YlxsT08 was used for the simultaneous synthesis of erythritol and the fusion protein. The yield, production, and productivity of erythritol reached 0.55 g/g of glucose, 166.18 g/L, and 1.98 g/(L· h), respectively, in a 5 L bioreactor. The recycled cells (49.77 U/ mg of DCW) exhibited a high catalytic efficiency in the bioconversion of maltodextrin to generate trehalose. The yield, production, and productivity of trehalose reached 0.67 g/g maltodextrin, 134.40 g/L, and 5.60 g/(L·h), respectively, in a 5 L bioreactor. The byproducts were removed by biological purification, and the resulting cells were recycled as catalysts for at least the next 5 rounds of trehalose production. Our novel strategy provides an ecologically sustainable and economically feasible alternative to enzyme combinations in trehalose production, offering a cost-effective and eco-friendly enzyme manufacturing method.
System oceny efektywności użytkowania aparatów słuchowych
- Piotr Szymański
2024 Pełny tekst
Celem rozprawy jest opracowanie metody oceny efektywności protezowania słuchu przy użyciu aparatów słuchowych, która pozwoli w łatwy sposób poddawać ocenie korzyść z użytkowania protez słuchowych w najbardziej typowych sytuacjach akustycznych. Przedstawiono genezę podjętych badań i na tej podstawie zaproponowano cele i tezy rozprawy doktorskiej. W pracy w pierwszej kolejności zawarto przegląd dotyczący rodzajów ubytku słuchu i jego wpływu na jakość życia, rozwiązania wspomagające osoby z ubytkiem słuchu oraz stosowane metody oceny efektywności użytkowania aparatów słuchowych. Wybrane metody omówiono zgodnie ze stanem wiedzy, ze szczególnym uwzględnieniem kwestionariusza APHAB (Abbreviated Profile of Hearing Aid Benefit), który jest jedną z najważniejszych i najczęściej aktualnie stosowanych metod dopasowania aparatów słuchowych. W celu realizacji badań i zebrania danych przygotowano aplikację internetową, która została wdrożona w około 200 punktach protetycznych. Uzyskane dane poddano analizie statystycznej. Analiza wykorzystująca test MUSHRA (MUltiple Stimuli with Hidden Reference and Anchor) oraz wnioskowanie regułowe oparte na logice rozmytej stała się podstawą modyfikacji zaproponowanego systemu. We wnioskach odniesiono się do tez badawczych, wdrożenia zaproponowanej metody, jak również podano kierunki rozwoju prowadzonych badań.
Szlifowanie na docierarkach sposobem zmniejszenia skażenia powierzchni ziarnami ściernymi w obróbce wykończeniowej
- Adam Barylski
2024 Dozór Techniczny
W artykule przedstawiono szkodliwość skażenia powierzchni mikroziarnami ściernymi w procesach docierania luźnym ścierniwem żeliwa szarego oraz sferoidalnego. Omówiono technologie szlifowania powierzchni płasko-równoległych z kinematyką docierania obiegowego, jako sposób zmniejszenia skażenia powierzchni ścierniwem po obróbce wykończeniowej.
Szlifowanie powierzchni płasko-równoległych z kinematyką docierania
- Adam Barylski
2024 Projektowanie i Konstrukcje Inżynierskie
Przedstawiono charakterystykę szlifowania powierzchni płasko-równoległych z kinematyką docierania obiegowego. Analizowano obróbkę materiałów konstrukcyjnych na docierarkach dwutarczowych. Porównano warunki i wyniki szlifowania z tradycyjnym docieraniem luźnym ścierniwem. Scharakteryzowano sposób wyrównywania powierzchni roboczych narzędzi oraz omówiono główne zalety szlifowania na docierarkach.