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Double Bias of Mistakes: Essence, Consequences, and Measurement Method
- Wioleta Kucharska
- Aleksandra Kopytko
2024 Pełny tekst Electronic Journal on Business Research Methods
There is no learning without mistakes. However, there is a clash between‘positive attitudes and beliefs’regarding learning processes and the ‘negative attitudes and beliefs’towardthese being accompanied bymistakes. Thisclash exposesa cognitive bias towardmistakesthat might block personal and organizational learning. This study presents an advanced measurement method to assess thebias of mistakes. The essence of it is the detection of the existing contradictionsbetween attitude and behavior towardmistakes at the personal and organizational levels,as well as combined.This study is based on empirical evidence from a sample of 768 knowledge workers, divided into biased and non-biased subsamples following the procedure proposed in this paper. Those subsamples were next applied to the structural model, examining knowledge,learning, and collaboration cultures (the KLC approach) 's influence on organizational intelligence to validate the proposed method. Results showed that the applied method efficiently detects the DBM and exposes that in doubly mistakes-biased knowledge-driven organizations, the influence of knowledge culture on the mistakes acceptance component of learning culture is negative. So, organizations with a dominated double bias of mistakes do not accept the affirmation of learning from mistakes.Summing up, this study constitutes the Double Bias of Mistakes Theory, which states that the clash between positive attitudes and beliefs regarding learning processes and negative attitudes and beliefs toward mistakes exposed by focusing on control managers (bosses) might block organizational learning from mistakes and, as a consequence, negatively affect organizational intelligence. Without the empirical support for this theory, there was a risk that the idea of accepting mistakes as a potential source of learning would be simplified by biased minds to mistakes tolerance and rejected as ridiculous. Accepting that mistakes can be a source of precious learning does not equal mistake tolerance. On the contrary, it is the first step to managing mistakes and creating efficient error avoidance systems thanks to lessons learned from failures. This study introduces the method of measurement and detection of theDouble Bias of Mistakes phenomenon, contributing to the science of organizational learning and collective intelligence-building.
Drinking water safety evaluation in the selected sub-Saharan African countries: A case study of Madagascar, Uganda and Rwanda
- Małgorzata Szopińska
- Wojciech Artichowicz
- Danuta Szumińska
- Daniel Kasprowicz
- Żaneta Polkowska
- Sylwia Fudala-Książek
- Aneta Łuczkiewicz
2024 SCIENCE OF THE TOTAL ENVIRONMENT
In the sub-Saharan region of Africa, access to safe drinking water remains limited in many countries. This study provides an overview of the quality of surface water and groundwater in rural and peri-urban areas of Madagascar, Uganda, and Rwanda. Selected physico-chemical parameters, inorganic species (including inorganic ions), and organic pollution indicators, such as total organic carbon, non-ionic surfactants, cationic surfactants, anionic surfactants, sum of phenolic compounds and formaldehyde, were analysed. Principal component analysis was applied to assess the variability of the water quality and identify regional dependencies. The inorganic ion composition in the majority of the studied samples meets WHO and EU requirements for drinking water intended for human consumption and poses no human health risk. However, an individual non-cancer-causing health index for nitrates and the values of Water Quality Index show a possible threat of ingesting the studied drinking water. The presence of surfactants (0.1–0.65 mgL-1), phenolic compounds (0.025–1.76 mgL-1) and formaldehyde (0.04–0.32 mgL-1) may also pose a risk to human, animal, and aquatic life. Additionally, in-situ measurements for E. coli and Total Coliforms conducted during the last field campaign in Madagascar (2022) revealed that all studied drinking water sources ranged from intermediate risk to unsafe. This result calls for the urgent need to enhance WASH (water, sanitation, and hygiene) services in the studied areas. The presence of both chemical and microbiological pollutants shows the need for the local authorities to develop and implement a catchment management plan to ensure the protection of water resources from potential pollution, and raise community awareness about the impact of human activity on water resources.
Driver fatigue detection method based on facial image analysis
- Sandra Cichocka
- Jacek Rumiński
2024
Nowadays, ensuring road safety is a crucial issue that demands continuous development and measures to minimize the risk of accidents. This paper presents the development of a driver fatigue detection method based on the analysis of facial images. To monitor the driver's condition in real-time, a video camera was used. The method of detection is based on analyzing facial features related to the mouth area and eyes, such as the frequency of blinking and yawning, mouth aspect ratio (MAR), and the duration of eye closure. The method was implemented in Python using a convolutional neural network (CNN). To validate the method, a dataset was created containing eye images that were subjected to various modifications, including the use of corrective glasses. The model's results confirm the method's effectiveness in detecting fatigue, achieving an average accuracy of 92% for eye detection and 82% for yawning detection under well-lit conditions.
Dual-Activity Fluoroquinolone-Transportan 10 Conjugates offer alternative Leukemia therapy during Hematopoietic Cell Transplantation
- Jan Lica
- Mateusz Heldt
- Miłosz Wieczór
- Paweł Chodnicki
- Natalia Ptaszyńska
- Anna Łęgowska
- Wioletta Brankiewicz
- Katarzyna Gucwa
- Anna Stupak
- Natalia Maciejewska
- Bhaskar Pradhan
- Agata Gitlin-Domagalska
- Dawid Dębowski
- Sławomir Milewski
- Maria Bieniaszewska
- Grzegorz Jan Grabe
- Andrzej Hellmann
- Rolka Krzysztof
2024 MOLECULAR PHARMACOLOGY
Hematopoietic cell transplantation (HCT) is often considered a last resort leukemia treatment, fraught with limited success due to microbial infections, a leading cause of mortality in leukemia patients. To address this critical issue, we explored a novel approach by synthesizing antileukemic agents containing antibacterial substances. This innovative strategy involves conjugating fluoroquinolone antibiotics, such as ciprofloxacin (CIP) or levofloxacin (LVX), with the cell-penetrating peptide (CPP) transportan 10 (TP10). Here, we demonstrate that the resultant compounds display promising biological activities in preclinical studies. These novel conjugates not only exhibit potent antimicrobial effects but are also selective against leukemia cells. The cytotoxic mechanism involves rapid disruption of cell membrane asymmetry leading to membrane damage. Importantly, these conjugates penetrated mammalian cells, accumulating within the nuclear membrane without significant effect on cellular architecture or mitochondrial function. Molecular simulations elucidated the aggregation tendencies of TP10 conjugates within lipid bilayers, resulting in membrane disruption and permeabilization. Moreover, mass spectrometry analysis confirmed efficient reduction of disulfide bonds within TP10 conjugates, facilitating release and activation of the fluoroquinolone derivatives. Intriguingly, these compounds inhibited human topoisomerases, setting them apart from traditional fluoroquinolones. Remarkably, TP10 conjugates generated lower intracellular levels of reactive oxygen species (ROS) compared to CIP and LVX. The combination of antibacterial and antileukemic properties, coupled with selective cytostatic effects and minimal toxicity towards healthy cells, positions TP10 derivatives as promising candidates for innovative therapeutic approaches in the context of antileukemic HCT. This study highlights their potential in search of more effective leukemia treatments.
Dual-band Millimetre Wave MIMO Antenna with Reduced Mutual Coupling Based on Optimized Parasitic Structure and Ground Modification
- Bashar Esmail
- Dustin Isleifson
- Sławomir Kozieł
2024 Pełny tekst Scientific Reports
In this study, a high-isolation dual-band (28/38 GHz) multiple-input–multiple-output (MIMO) antenna for 5G millimeter-wave applications is presented. The antenna consists of two interconnected patches. The primary patch is connected to the inset feed, while the secondary patch is arc-shaped and positioned over the main patch, opposite to the feed. Both patches function in the lower 28 GHz band, while the primary patch is accountable for inducing the upper 38 GHz band. An expedited trust-region (TR) algorithm is employed to optimize the dimensions of the antenna components, ensuring the antenna operates efficiently with high reflection at both bands. The antenna demonstrates a gain exceeding 7 dBi at both frequencies. An array of four antennas is configured orthogonally to create a MIMO system with isolation surpassing 19 dB. The isolation is further enhanced through the addition of a circular parasitic patch at the front and modifications made to the ground. The TR method is employed again to optimize their parameters and achieve the desired isolation, exceeding 32 dB at both bands. The MIMO system demonstrates outstanding diversity performance at both frequencies, characterized by low values of the envelope correlation coefficient (ECC) (<10−4), channel capacity loss (CCL) (<0.03 bit/s/Hz), and total active reflection coefficient (TARC) (<−10 dB). Additionally, it secures a diversity gain (DG) exceeding 9.99 dB. The MIMO system is manufactured and tested, showing good alignment between simulation and measurement data for all performance metrics.
Dual-Polarized Wideband Bandpass Metasurface-Based Filter
- Adnan Noor
- Sławomir Kozieł
2024 IEEE Antennas and Wireless Propagation Letters
This paper presents a novel metasurface-based bandpass filter. The structure is realized by simply patterning a double-sided AD250 substrate, and does not require any vias or insertion of lumped elements. The top layer is an annular- aperture-array with multiple inner conductors, whereas the bottom layer is a first-order Hilbert-curve array. FEM-based simulation results of the filter are obtained using HFSS. The experimental validation is carried out using a VNA, with the experimental setup placed inside an anechoic chamber. The presence of multiple length scales and fractal nature of the bottom Hilbert-curve layer results in a wide operational bandwidth, and good angular stability. The structure exhibits an operating bandwidth from 5.32 to 8.25 GHz. A good agreement between experimental and numerical results is observed. The filter also features good angular stability for both TE (s-polarized) and TM (p-polarized) polarizations. The thickness of the structure is only 0.796 mm (i.e. just 0.018 at the center frequency of the filter), which makes it very compact.
Dual-Purpose Converters for DC or AC Grid as Energy Transition Solution: Perspectives and Challenges
- Oleksandr Husev
- Dmitri Vinnikov
- Samir Kouro
- Frede Blaabjerg
- Carlos Roncero-Clemente
2024 IEEE Industrial Electronics Magazine
We present a novel concept of a dual-purpose power converter for dc or ac grids. These universal dc–dc/ac power electronic interfaces are suitable for application in the dc or single-phase or three-phase ac grids using the same terminals. The idea is to utilize the same semiconductors and passive components in the dc–ac and in the dc–dc configurations with minimal additional components and to maximize their effectiveness in any mode. Possible realizations along with challenges of simultaneous application of dc and ac grids are discussed. The “Conclusion” section addresses different fields of application and the main benefits, challenges, and future research.
Dyadic Interviews in Qualitative Research: Your Practical Guide
- Joanna Szulc
- Nigel King
2024
From world-class qualitative experts comes a practical, step-by-step introduction to doing dyadic interviews. Including the perspective of both the interviewer and the interviewee, this book shows how to use this innovative interview technique to gain new insights into your research problem. The book will also equip you with the tools and confidence to overcome potential challenges associated with the method and fully realise its advantages. The book includes: · Real world interview extracts so you can see how techniques work in practice · Case studies from a wide range of disciplines and contexts · A researcher’s checklist with step-by-step guidance through the whole research process · Content covering digital methods as well as in-person interviews. This is the definitive roadmap for conducting dyadic interviews for students and researchers doing qualitative research across the social sciences.
Dynamic Execution of Engineering Processes in Cyber-Physical Systems of Systems Toolchains
- Federico Montori
- Marek Sylwester Tatara
- Pal Varga
2024 Pełny tekst IEEE Transactions on Automation Science and Engineering
Engineering tools support the process of creating, operating, maintaining, and evolving systems throughout their lifecycle. Toolchains are sequences of tools that build on each others' output during this procedure. The complete chain of tools itself may not even be recognized by the humans who utilize them, people may just recognize the right tool being used at the right place in time. Modern engineering processes, however, do not value such ad-hoc choice of tooling, because of their uncontrolled nature. Building upon the Extended Automation Engineering Model defined by the IEC 81346 standard, this paper proposes to automate the toolchain building and execution process for Cyber-Physical System of Systems (CPSoS), utilizing key principles of the Eclipse Arrowhead framework. The proposed toolchain automation solution addresses issues such as tool interoperability, interaction, automation, and dynamic choreography. The feasibility of this set of integrated concepts is validated through an Arrowhead-based toolchain choreography demonstration.
Dynamic impedance measurements of the Direct Methanol Fuel Cell cathode at various operating temperatures
- Łukasz Gaweł
- Dominika Parasińska
2024 Pełny tekst INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
This article discusses the application of impedance analysis for diagnosing the cathode of a direct methanol fuel cell at various operating temperatures. The Dynamic Electrochemical Impedance Spectroscopy technique coupled with a linear current scan was applied for this purpose. This technique allowed the observation of changes in the cathode's properties in the fuel cell operating under real working conditions. An equivalent model based on the thin-film flooded agglomerate model describing the cathode's behavior was presented, and changes in its parameters were compared with current load and different temperatures. Polarization resistance of the active site and carbon support was obtained. Changes in the slope of the resistance curves with increasing load have been observed, which can suggest the change in the electrode process. Differences in slopes depending on temperature were also recorded.
Eco-friendly modification of bitumen: The effects of rubber wastes and castor oil on the microstructure, processability and properties
- Maciej Sienkiewicz
- Przemysław Gnatowski
- Mateusz Malus
- Anna Grzegórska
- Hossein Ipakchi
- Maryam Jouyandeh
- Justyna Kucińska-Lipka
- Francisco Javier Navarro
- Mohammad Saeb
2024 Pełny tekst JOURNAL OF CLEANER PRODUCTION
The bitumen industry in the European Union is facing several difficulties, including rising demand, unstable oil supply, rising prices for synthetic polymer modifiers, and a focus on lowering carbon footprint. Bitumen modification with crumb rubber (CR) is one of the most promising solution to these challenges. However, CR-modified bitumen have poor processability and low storage stability. To overcome these flaws we are introducing a sustainable approach for ecological modification of bitumen taking advantage of renewable resources. For this reason, unmodified castor oil was selected as a green modifier of reclaimed rubber dust. The ecologically modified bitumen underwent visco-elastic behavior analysis based on rheological tests varying the temperature. The modification with rubber-oil improved the longevity of typical pavement, featured by an exceptional deformation resistance at elevated temperatures (well above 70°C, the maximum pavement temperature reported in the region). The Cole-Cole graphs and black space diagrams unraveled the enhanced elasticity of bitumen. Technically, in comparison to plain bitumen, the compatibility ratio of modified bitumen to aggregates showed an uplift by 258%. The environmentally friendly bitumen modified ecologically herein revealed potential for performance window enlargement. Nevertheless, future investigations should focus on optimization of the bitumen formulation, along with examination of other sustainable moieties for the sake of commercialization of the developed binders in pavement construction.
Edible black ant Smith (Carebara vidua) as human food – A systematic review
- Shahida Anusha Siddiqui
- L.-H. Ho
- S.c. Adimulam
- A. Nagdalian
- B. Yudhistira
- Roberto Castro Munoz
- S.a. Ibrahim
2024 Pełny tekst Journal of Insects as Food and Feed
Meeting food security is one of the major global challenges to ensure sufficient supply of food for current and future generations, considering increasing population growth and climate change issues. Consequently, the consumption of edible insects as an alternative food source has recently gained global attention for combating global food insecurity. The present review aims to provide information on the recent progress in consumption of edible black ant Smith, particularly Carebara vidua, as the main focus. The global consumption record of edible black ant Smith and consumer acceptance as well as the strategies used to increase consumer acceptance of eating edible black ant smith were proposed. In addition, the bioecology of black ant Smith was covered in this review. Further, details are provided in this review on the benefits to health, economy, and environment of practicing eating edible insects such as black ant Smith. Focus on the potential uses of Carebara vidua as a food ingredient in culinary cuisine and their safety concerns from rearing until processing were highlighted. The SCOPUS database was analysed using bibliometric software to understand the connections between recent scientific outputs and ant as human food thoroughly. BioRender software was used to create scientific figures. It is noteworthy to highlight that black ant smith contains high protein and micronutrient, especially iron and zinc are higher than that of plant-, animal-based food, and seafood that contribute significantly to meeting the daily protein and mineral intake amount for human. Moreover, the exhibition of antimicrobial and antioxidant properties of edible black ant smith suggests that it can be used as a future functional ingredients for food, pharmaceutical, and cosmetics purposes. Hence, edible black ant smith is promising as an alternative and potential source of food or medicine for sustainable food security.
Edible dragonflies and damselflies (order Odonata) as human food – A comprehensive review
- Shahida Anusha Siddiqui
- K. Asante
- N. Ngah
- Y.r. Saraswati
- Y.s. Wu
- M. Lahan
- O.f. Aidoo
- I. Fernando
- S.n. Povetkin
- Roberto Castro Munoz
2024 Pełny tekst Journal of Insects as Food and Feed
The rapid growth of the human population leads to a big concern about the food y and demand worldwide. However, due to the reduction in global arable land area, humans need to find alternative food sources to fulfil their needs. Consequently, edible insects have been identified as a promising solution to ameliorate food security and increase global nutrition. Among more than 2,100 identified edible insect species, dragonflies and damselflies (order Odonata) are considered as one of nutritious food resources. Nevertheless, detailed information on the frequency and distribution of consumption of odonatans around the world is scattered and poorly documented. Based on this review, at least 61 out of 1,964 species of odonatans were reported consumed by people worldwide. The most consumed dragonflies (suborder Epiprocta; infraorder Anisoptera) are from the family of Libellulidae, followed by Aeshnidae and Gomphidae, whereas the most consumed edible damselflies (suborder Zygoptera) are from the Coenagrionidae family. Many nutrients, including proteins, lipids, energy, fibre, vitamins, and minerals are abundant in edible odonatans. Moreover, studies reported that humans employed these insects as therapeutic agents to remedy various ailments. Challenges associated with the consumption of edible odonatans include safety concerns, legal frameworks, and limited information on their bioecology which become barrier for their successful mass-rearing. However, because entomophagy is gradually gaining recognition, new and more improved methods of rearing are now being developed including for edible odonatans, encouraging sustainable insect farming. As the world strives to achieve the sustainable development goals, insect farming will pave a way for resources to be utilised for sustainable economic development.
Edible Lepidoptera as human foods – a comprehensive review
- Shahida Anusha Siddiqui
- N. Ngah
- A.m. Eddy-Doh
- I. Ucak
- M. Afreen
- I. Fernando
- S. Singh
- M.a. Shah
- S.n. Povetkin
- Roberto Castro Munoz
2024 Pełny tekst Journal of Insects as Food and Feed
As the global population continues to grow, traditional protein sources like meat and fish are becoming increasingly unsustainable due to their environmental impact. Edible insects, on the other hand, are highly nutritious, require minimal resources to produce, and emit significantly fewer greenhouse gases than traditional livestock. Lepidoptera, one of the most diverse insect orders, contains some popular edible species that have been consumed traditionally for centuries across the globe. Based on this review, about 24 families with a total of about 350 edible lepidopteran species were recorded. They are often praised for their excellent nutritional value, such as having high protein and healthy fat content. Edible lepidopterans also contain minerals, essential amino acids, and vitamins, making them a nutritious addition to a balanced diet. They also contain bioactive compounds which have various nutraceutical and pharmaceutical properties. Furthermore, some edible lepidopterans can be farmed and require minimal space and resources. However, there are significant challenges associated with their use as food. One of the primary challenges is the lack of regulations governing their production and distribution, which creates uncertainty for consumers and businesses alike. Consumer acceptance is also a significant barrier to the widespread adoption of insects as food. To overcome these challenges, there is a need for clear regulations that ensure the safety and quality of insect-based products. Furthermore, it is important to raise awareness about the nutritional and environmental benefits of edible insects as sustainable food for the future to promote their acceptance among consumers.
Edu Inspiracje WZiE: Czy mikrokwalifikacje i cyfrowe odznaki zmienią oblicze edukacji?
- Karol Flisikowski
- Alina Guzik
2024 Pismo PG
Mikrokwalifikacje nazywane również mikropoświadczeniami (micro- -credentials), mówiąc prostymi słowami, są cyfrowymi certyfikatami potwierdzającymi uzyskanie umiejętności, wiedzy lub kompetencji. To dowody ukończenia mniejszych (niż określają np. dyplomy uniwersyteckie) form edukacyjnych takich jak kursy e-learningowe, warsztaty lub szkolenia. Pozwalają też szybko pokazać to, co umiemy, i przedstawić w postaci atrakcyjnego cyfrowego portfolio.
EEG-Based Analysis of ASMR Stimuli: A Pilot Study of Neuropsychological Responses through Conventional vs. Bone-Conduction Headphones
- Sahar Seifzadeh
- Bożena Kostek
- L. Giulia Poerio
2024 Vibrations in Physical Systems
In this study, the impact of ASMR (Autonomous Sensory Meridian Response) experiences delivered through different types of headphones was evaluated with respect to neural responses and anxiety levels. The EEG data of a 24-year-old participant was recorded while he underwent ASMR stimulation using conventional and bone-conduction headphones. The State-Trait Anxiety Inventory (STAI) assessed anxiety levels before and after ASMR stimulation, showing decreased state anxiety following intervention. Based on spectral analysis of Electroencephalography (EEG) data, significant differences were found between headphone types and cognitive tasks (Mathematical calculations). Using conventional headphones, gamma activity was evident in the posterior brain regions, suggesting that headphone type may influence ASMR-induced neural activity. The pilot study findings emphasize the importance of refining auditory delivery methods for clinical applications to maximize ASMR efficacy and therapeutic outcomes.
Effect of Agitation and Temporary Immersion on Growth and Synthesis of Antibacterial Phenolic Compounds in Genus Drosera
- Wojciech Makowski
- Kinga Mrzygłód
- Agnieszka Szopa
- Pawel Kubica
- Marta Krychowiak-Maśnicka
- Krzysztof Michał Tokarz
- Barbara Tokarz
- Iga Ryngwelska
- Ewa Paluszkiewicz
- Aleksandra Krolicka
2024 Biomolecules
Sundews (Drosera sp.) are the source of biologically active secondary metabolites: phenolic acids, flavonoids, and 1,4-naphtoquinones. Because obtaining them from the natural environment is impossible (rare and endangered species), in this study modifications of traditional tissue cultures grown in solid medium (SM), such as agitated cultures (ACs) (cultures in liquid medium with rotary shaking) and temporary immersion bioreactors PlantformTM (TIB), were used for multiplication of four sundew species: Drosera peltata, Drosera indica, Drosera regia, and Drosera binata, with simultaneously effective synthesis of biologically active phenolic compounds. Each species cultivated on SM, AC, and TIB was tested for biomass accumulation, the content of total phenols and selected phenolic derivative concentrations (DAD-HPLC), the productivity on of phenolic compounds, as well as its antibacterial activity against two human pathogens: Staphylococcus aureus and Escherichia coli. The results showed that the type of culture should be selected for each species separately. Phytochemical analyses showed that the synthesis of secondary metabolites from the groups of phenolic acids, flavonoids, and 1,4-naphthoquinones can be increased by modifying the cultivation conditions. D. regia turned out to be the richest in phenolic compounds, including 1,4-naphtoquinones: plumbagin and ramentaceone. Extracts from D. indica and D. regia tissue showed strong antibacterial activity against both pathogens. It has also been shown that the growth conditions of sundews can modify the level of secondary metabolites, and thus, their biological activity.
Effect of applied standard wood machining fluid on colour and chemical composition of the machined wood surface
- Daniel Chuchała
- Agata Sommer
- Kazimierz Orłowski
- Hanna Staroszczyk
- Szymon Mania
- Jakub Sandak
2024 Pełny tekst European Journal of Wood and Wood Products (HOLZ ALS ROH-UND WERKSTOFF)
Appropriate monitoring of wood machining processes is a key issue to ensure the expected quality of the processed wood, expected efficiency and minimize energy consumption of production processes. A new trend is the design of environmentally friendly machining fluids. In this paper, as a preliminary study in this field, the effect of applied standard wood machining fluid on changes in the colour and chemical composition of the machined wood surface is presented. Scots pine wood (Pinus sylvestris L.) was used for this research. Colour measurements were carried out based on the three-axis CIELab system test in time intervals and coefficients such as: colour chroma (Cab*), colour saturation (Sab*), colour hue (h°), and total colour changes (ΔE*). Changes in chemical composition were analysed on the Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR FT-IR). The results confirmed that standard machining fluids cause a significant change in the colour of the treated pine surface, which decreases over time but is still present even after 24 h. For the spectral analysis, no chemical changes were observed between the machining fluid and the wood. However, the fluid particles remained in the wood after 24 h. In order to reduce the effect of the machining fluid on the colour of the wood, its composition should be changed to allow and/or accelerate the evaporation of their components from the treated wood surface.
Effect of bile salts and their conjugation on the process of lipolysis
- Natalia Łozińska
2024
The main aim of the PhD dissertation was to indicate the importance of conjugation of bile salts (BS) on the level of lipolysis, determine factors influencing the alteration of BS composition, and establish processes controlling the rate of lipolysis. Experimental results (in-vitro digestion models, interfacial studies) and meta-analysis of literature data were combined to determine the most influential factors affecting the rate of lipolysis. The results demonstrate that several factors such as antibiotics, disease state, and gut microbiota composition may affect the lipid digestion process via the action of BS. Conjugated forms of BS - sodium taurocholate (NaTC) were shown to enhance free fatty acids (FFA) release to a significantly higher level than unconjugated forms of BS - sodium deoxycholate (NaDC) present in our gastrointestinal tract. NaTC showed greater potential to adsorb to the lipid droplet enhancing the adsorption of lipase and promoting the emulsification process. Moreover, NaTC required fewer molecules and surfactant concentration to create aggregates responsible for incorporating lipolysis products from the oil interphase. The lipolysis driven by NaTC could achieve greater FFA release due to faster removal of lipolysis products via the desorption process, allowing the continuous process of lipid digestion. The lipolysis was shown to be controlled by the concentration of conjugated BS by modulation of five identified processes.
Effect of bio-polyol molecular weight on the structure and properties of polyurethane-polyisocyanurate (PUR-PIR) foams
- Adam Olszewski
- Paulina Kosmela
- Laima Vevere
- Mikelis Kirpluks
- Ugis Cabulis
- Łukasz Piszczyk
2024 Pełny tekst Scientific Reports
The increasing interest in polyurethane materials has raised the question of the environmental impact of these materials. For this reason, the scientists aim to find an extremely difficult balance between new material technologies and sustainable development. This work attempts to validate the possibility of replacing petrochemical polyols with previously synthesized bio-polyols and their impact on the structure and properties of rigid polyurethane-polyisocyanurate (PUR-PIR). To date, biobased polyols were frequently used in the manufacturing of PU, but application of bio-polyols synthesized via solvothermal liquefaction using different chains of polyethylene glycol has not been comprehensively discussed. In this work, ten sets of rigid polyurethane foams were synthesized. The influence of bio-polyols addition on foam properties was investigated by mechanical testing, thermogravimetric analysis (TGA), and cone calorimetry. The structure was determined by scanning electron microscopy (SEM) and a gas pycnometer. The tests revealed a significant extension of foam growth time, which can be explained by possible steric hindrances and the presence of less reactive secondary hydroxyl groups. Moreover, an increase average size of pores and aspect ratio was noticed. This can be interpreted by the modification of the cell growth process by the introduction of a less reactive bio-polyol with different viscosity. The analysis of foams mechanical properties showed that the normalized compressive strength increased up to 40% due to incorporation of more cross-linked structures. The thermogravimetric analysis demonstrated that the addition of bio-based polyols increased temperature of 2% (T2%) and 5% (T5%) mass degradation. On the other hand, evaluation of flammability of manufactured foams showed increase of total heat release (HRR) and smoke release (TSR) what may be caused by reduction of char layer stability. These findings add substantially to our understanding of the incorporation of bio-polyols into industrial polyurethane systems and suggest the necessity of conducting further research on these materials.