2024 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2024

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Sintering Parameter Investigation for Bimetallic Stainless Steel 316L/Inconel 718 Composite Printed by Dual-Nozzle Fused Deposition Modeling
- Cho-pei Jiang
- Masrurotin Masrurotin
- Maziar Ramezani
- Alvian Toto Wibisono
- Ehsan Toyserkani
- Wojciech Macek
2024 Full text RAPID PROTOTYPING JOURNAL
Fused deposition modeling (FDM) nowadays offers promising future applications for fabricating not only thermoplastic-based polymers but also composite PLA/Metal alloy materials, this capability bridges the need for metallic components in complex manufacturing processes. The research is to explore the manufacturability of multi-metal parts by printing green bodies of PLA/multi-metal objects, carrying these objects to the debinding process, and varying the sintering parameters. Three different sample types of SS316L part, Inconel 718 part, and bimetallic composite of SS316L/IN718 were effectively printed. After the debinding process, the printed parts (green bodies), were isothermally sintered in non-vacuum chamber to investigate the fusion behavior at four different temperatures in the range of 1270°C -1530°C for 12 hours and slowly cooled in the furnace. All samples was assessed including geometrical assessment to measure the shrinkage, characterization (XRD) to identify the crystallinity of the compound, and microstructural evolution (Optical microscopy and SEM) to explore the porosity and morphology on the surface. The hardness of each sample types was measured and compared. The sintering parameter was optimized according to the microstructural evaluation on the interface of SS316L/IN718 composite. The investigation indicated that the de-binding of all the samples was effectively succeeded through less weight until 16% when the PLA of green bodies was successfully evaporated. The morphology result shows evidence of an effective sintering process to have the grain boundaries in all samples, while multi-metal parts clearly displayed the interface. Furthermore, the result of XRD shows the tendency of lower crystallinity in SS316L parts, whilst IN718 has a high crystallinity. The optimal sintering temperature for SS316L/IN718 parts is 1500 ⁰C. The hardness test concludes that the higher sintering temperature gives a higher hardness result. This study highlights the successful sintering of a bimetallic stainless steel 316L/Inconel 718 composite, fabricated via dual-nozzle fused deposition modeling, in a non-vacuum environment at 1500°C. The resulting material displayed maximum hardness values of 872 HV for SS316L and 755.5 HV for IN718, with both materials exhibiting excellent fusion without any cracks.
Sleep alterations in treatment-resistant depression patients undergoing ketamine treatment
- Aleksander Kwaśny
- Wiesław Jerzy Cubała
- Adam Włodarczyk
- Krzysztof Pastuszak
2024 Pharmacological Reports
Background This study examines self-reported sleep alterations in treatment-resistant depression (TRD) inpatients following intravenous ketamine administration. Methods This is a post-hoc analysis of a naturalistic observational study, which enrolled 28 inpatients with treatment-resistant major depressive disorder and analyzed self-reported sleep changes (items 1–4; ‘insomnia’, ‘nighttime restlessness’, ‘early morning waking’, ‘hypersomnia’) in Inventory of Depressive Symptomatology 30-item (IDS SR-30) in responders and non-responders stratified per Montgomery-Åsberg Depression Rating Scale (MADRS) during short-term ketamine treatment. Results Responders, as well as non-responders, did not experience significant changes in IDS SR-30 sleep items (‘insomnia’, ‘nighttime restlessness’, ‘early morning waking’, ‘hypersomnia’) (p’s > 0.05) at 7-day follow-up after eight intravenous ketamine infusions as compared to baseline. Conclusion Neither responders, nor non-responders reported any significant alterations in sleep patterns during ketamine infusions. These findings are not in line with current literature, as so far modest improvements in sleep during ketamine treatment have been reported. Results should be interpreted with caution, primarily due to the small sample size.
Smart Karyotyping Image Selection Based on Commonsense Knowledge Reasoning
- Yufeng Xu
- Lei Shi
- Juan Wang
- Haoxi Zhang
- Edward Szczerbicki
2024 Full text CYBERNETICS AND SYSTEMS
Karyotyping requires chromosome instances to be segmented and classified from the metaphase images. One of the difficulties in chromosome segmentation is that the chromosomes are randomly positioned in the image, and there is a great chance for chromosomes to be touched or overlap with others. It is always much easier for operators and automatic programs to tackle images without overlapping chromosomes than ones with largely overlapped chromosomes. In order to reduce the processing difficulty, adding a smart image selection procedure ahead of segmentation is practical and necessary. In this paper, we introduce the Smart Karyotyping Image Selection (SKIS) based on Commonsense Knowledge Reasoning. The initial experiment demonstrates that the proposed approach can select the expected images based on reasoning and benefit following karyotyping processes.
Smartphone-Assisted and Optical Quantification of Copper and Glucose Using Palm Wine-Tailored Carbon Dots and Their Multiple Logic Gate Application
- Anisha Mandal
- Subrahmanyam Sappati
- Ankita Karmakar
- Supratim Pradhan
- Iwona Gabriel
- Swambabu Varanasi
2024 ACS Biomaterials Science & Engineering
In this work, potassium, sulfur, nitrogen, and chlorine self-doped carbon dots (CDs) were hydrothermally synthesized using palm wine as a carbon source. The palm wine-derived CDs (PW-CDs) are amorphous in nature and displayed an average particle size of 4.19 ± 0.89 nm. The as-synthesized CDs are used to fabricate a photoluminescent sensing probe to simultaneously detect Cu2+ and glucose via the “Turn ON−OFF−ON” mechanism. The PL quenching mechanism of PW-CDs enables the selective and sensitive detection of Cu2+ ions with a detection limit (LOD) of 0.8 ppb (4.7 nM). The sensing probe quantified Cu2+ in tap water, drinking water, and e-waste samples to prove its viability. Using CDs to quantify copper in e-waste leachate samples is a novel approach as no prior instances of such application have been reported. The system’s performance is considered to be highly reproducible due to the relative standard deviation being <6.64%, along with excellent recoveries within the range of 3.24−109.86%. The quenched PL can be recovered by introducing glucose into the PW-CD + Cu2+ system; this strategy is employed to quantify glucose with a LOD of 0.11 ppm (0.61 μM). The feasibility of this sensor was confirmed by the determination of glucose in actual human plasma specimens of diabetic patients. It is to be noted that these samples were neither diluted nor spiked with glucose. The developed PW-CD + Cu2+ sensing system yields satisfactory recoveries of 93.45−107.37%. This probe was also incorporated into a smartphone-based sensing platform to detect Cu2+ and glucose with desirable recoveries. The proposed smartphone-based sensing platform is flexible, reliable, and accurate, making it suitable for resource-constrained areas. Furthermore, based on the effect of Cu2+ ions and glucose on the PL response and absorbance spectra of PW-CDs, four logic gates (YES, IMPLICATION, NOT, and OR) were designed, and PW-CDs were also used for cell imaging applications.
Smartphone-based digital image colorimetry for the determination of total capsaicinoid content in chili pepper extracts
- Khrystyna Vakh
- Zarina Mallabaeva
- Marek Tobiszewski
2024 SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
A simple smartphone-based digital image colorimetry was proposed for the determination of total capsaicinoid content and the assessment of chili pepper pungency. The biobased solvent D-limonene was used for the first time to isolate analytes. Capsaicinoids were efficiently separated from chili pepper by solid-liquid extraction with D-limonene followed by partitioning of the analytes into the ammonium hydroxide solution to eliminate the matrix interference effect. For colorimetric detection of total capsaicinoid content, a selective chromogenic reaction was performed using Gibbs reagent (2,6-dichloroquinone-4-chloroimide). Measurements were performed using a smartphone-based setup and included image analysis with the program ImageJ. The limit of detection of the proposed procedure was 0.15 mg g-1. The intra-day repeatability did not exceed 10.0%. The inter-day repeatability was less than 16.5 %. The comparison of the smartphone-based procedure with high-performance liquid chromatography showed satisfactory results.
Smooth least absolute deviation estimators for outlier-proof identification
- Janusz Kozłowski
- Zdzisław Kowalczuk
2024 Full text MECHANICAL SYSTEMS AND SIGNAL PROCESSING
The paper proposes to identify the parameters of linear dynamic models based on the original implementation of least absolute deviation estimators. It is known that the object estimation procedures synthesized in the sense of the least sum of absolute prediction errors are particularly resistant to occasional outliers and gaps in the analyzed system data series, while the classical least squares procedure unfortunately becomes of little use for reliably identifying systems in the presence of destructive measurement errors. Bearing in mind that the classic task of minimizing the quality functional of absolute deviations encounters fundamental analytical problems, it is proposed to use a dedicated iterative estimator for off-line evaluation of the parameters of the analyzed process. In addition, a simplified recursive version of the absolute deviation estimation procedure was developed, which allows for practical on-line tracking of the evolution of variable parameters of non-stationary systems. Importantly, a novel refinement of the discussed absolute deviation estimators was proposed to effectively overcome some inconvenient numerical effects. We also present an interesting comparison of the improved (by non-linear modification) iterative absolute-deviation estimator with the classical Gauss-Newton gradient algorithm, which leads to constructive conclusions. Finally, using computer simulations, the operation of the developed iterative and recursive estimators minimizing the absolute deviation is illustrated. The work ends with an indication of directions for further research.
Social Media in the Fashion Industry. Fundamentals, Strategy and Research Methods
- SanMiguel Patricia
- Harley Tekila Nobile
- Cristina Sánchez-Blanco
- Nadzeya Sabatini
2024
This book introduces social network fundamentals in the fashion domain. It addresses the creation of social media marketing plans, highlighting strategic approaches that allow fashion brands to differentiate themselves in the ephemeral and challenging fashion context. Through a variety of academic and professional sources and by sharing the results of their own research, the authors present research methodologies, including netnography, visual, sentiment, and argumentation analysis, for developing rigorous studies to gain social media insights that can be useful for decision-making and value creation. The book also discusses future trends regarding social media management in the fashion domain via interviews with senior fashion experts. This cutting-edge book that combines theory and practice will appeal to undergraduate and master students across a broad range of fields including fashion studies, marketing, digital marketing, and communication and to young professionals who are starting to work in social media. In addition, this book is also developed for young researchers and PhD students employing social media analysis in their studies.
Society 4.0: Issues, Challenges, Approaches, and Enabling Technologies
- Edward Szczerbicki
- Ngoc Thanh Nguyen
2024 Full text CYBERNETICS AND SYSTEMS
This guest edition of Cybernetics and Systems is a broadening continuation of our last year edition titled “Intelligence Augmentation and Amplification: Approaches, Tools, and Case Studies”. This time we cover research perspective extending towards what is known as Society 4.0. Bob de Vit brought the concept of Society 4.0 to life in his book “Society 4.0 – resolving eight key issues to build a citizens society”. From the Systems Science point of view, one of this concept’s enabling technologies mechanisms would be Semantic Web driven by Artificial Intelligence, Augmented Intelligence, Digital Twin, Platform Economies, Internet of Things, Smart Social Networks, Machine Learning/Deep Learning, and Cyber Physical Systems. With the help and progress in these research themes and technologies, business, commerce, production etc. would become increasingly smarter, and machines talking to machines would handle most of our daily activities, including decision-making, sustainability, wellbeing, and security. The aim of this Guest Edition of Cybernetics and Systems is to address some aspects in this global transformation path of our society
Soft Tissue Retraction Maneuver in Cone Beam Computed Tomography Prior to Crown-Lengthening Procedure—A Technical Note
- Paulina Adamska
- Marcin Stasiak
- Wojciech Dąbrowski
- Dorota Pylińska-Dąbrowska
- Łukasz Adamski
- Adam Zedler
- Ewa Kozłowska
- Michal Studniarek
2024 Full text Journal of Clinical Medicine
Background: An accurate determination of the biological width and the relationship of the cemento-enamel junction with the border of the alveolar bone is crucial during a clinical crown-lengthening (CCL) procedure. The aim of this study was to present a technical note about the retraction techniques in cone beam computed tomography (CBCT) prior to CCL, highlighting the significant enhancement in procedural accuracy and predictability that these techniques offer. Methods: Clinical and radiological examinations should be performed before a CCL procedure. It is necessary to determine the length of the tooth crowns, the periodontal pockets’ depth, and the phenotype of the gingiva. The ideal CBCT examination should be performed with soft tissue retraction. This can be achieved using retractors or cotton rolls. Results: Retraction of the lips, cheeks, and tongue allows one to assess the marginal gingiva, the cemento-enamel junction, and the alveolar bone. A detailed plan of the CCL procedure, which involves retraction, ensures both the aesthetic appeal and the achievement of a newly defined gingival zenith, enhancing the overall visual harmony. Conclusions: Compared with conventional radiographic imaging, the soft tissue retraction maneuver in CBCT prior to CCL surgery offers an effective approach to the evaluation and diagnosis of soft and hard tissue. This is because of the detailed planning of the aesthetic CCL procedure. Such an approach leads to superior aesthetic outcomes in dentistry, contributing to the advancement of aesthetic dentistry through a harmonious blend of art and science.
Soil burial degradation of chemically compatibilized poly(butylene adipate-co-terephthalate)/thermoplastic starch/poly(ε-caprolactone)/cellulose biocomposites
- Aleksander Hejna
- Mateusz Barczewski
- Paulina Kosmela
- Mohammad Saeb
2024 INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
Developing bio-blends and biocomposites has become a widespread strategy to combat plastic pollution in line with sustainability principles and decarbonization necessities. Although chemically modified ternary and quaternary biocomposites are developing rapidly because of their broader processing and performance windows than single matrix and binary counterparts, a few have been reported about their biodegradation. Herein, diisocyanates-based chemically modified ternary biocomposites based on poly(butylene adipate-co-terephthalate), thermoplastic starch (TPS), poly(ε-caprolactone) (PCL), and cellulose (Mater-Bi/PCL/cellulose) are prepared and undergone soil burial biodegradation providing a broader perspective on biodegradation of complicated systems. The mass gain of sunflower sprouts, weight retention, and the appearance of biocomposites are studied and discussed in the course of biodegradation. The unfilled Mater-Bi/PCL bio-blends presented moderate mass loss over 12 weeks, attributed to the presence of TPS in the Mater-Bi phase. The PCL addition hindered TPS decomposition and featured a noticeably lower degradation rate compared to previous reports. A significant increase in the b* parameter (position on the blue-yellow axis in the CIELAB color space), along with the yellowness and whiteness indices, was observed. Prior to soil burial, roughness differences were negligible. Still, they significantly increased over time due to the higher hydrophilicity of unfilled Mater-Bi/PCL and biocomposite containing unmodified filler.
Solid and liquid fractionation of sugarcane and Agave bagasse during ozonolysis and enzymatic hydrolysis: Impact on biohydrogen and biogas production
- Jacobo Pérez-Barragán
- Octavio García-Depraect
- Rafael Maya-Yescas
- Ramiro Vallejo-Rodríguez
- Hasbleidy Palacios-Hinestroza
- Mónica Coca
- Roberto Castro Munoz
- Elizabeth León-Becerril
2024 INDUSTRIAL CROPS AND PRODUCTS
Sustainable and cost-efficient lignocellulosic biomass-to-energy bioprocesses require assessing the main components released during biomass fractionation. This study assessed the mesophilic biochemical potential of biohydrogen (BHP) and methane production (BMP) from sugarcane bagasse (SCB) and cooked (CAB) and uncooked (UAB) Agave bagasse. A systematic comparative analysis was performed for the liquid and solid fractions derived from classical enzymatic hydrolysis and ozonolysis-assisted enzymatic hydrolysis. Ozonolysis partially delignified the materials tested while preserving most fermentable sugars and avoiding the generation of inhibitors. During hydrolysis, ozonolysis also led to higher sugar yields and organic matter solubilization regardless of the bagasse type. Hydrolysates with ozonated material showed the highest BHP of 135, 94 and 105 NmL-H2/g-VSfed and BMP of 250, 269 and 247 NmL-CH4/g-VSfed, for SCB, CAB, and UAB, respectively. The total amount of energy harvested was dependent on the material tested and the biomass conversion process applied. Compared with raw material, ozonolysis, followed by enzymatic hydrolysis, increased both the BHP and BMP by 153–371% and 5–53%, respectively.
Solubility enhancement of metronidazole using natural deep eutectic solvents: Physicochemical and thermodynamic studies
- Adrian Szewczyk
- Dorota Warmińska
- Jakub Ruszkowski
- Michał Szymankiewicz
- Magdalena Prokopowicz
2024 JOURNAL OF MOLECULAR LIQUIDS
This research aimed to explore the utility of natural deep eutectic solvents (NADES) as the co-solvents for slightly water-soluble metronidazole (MNZ). After testing 70 wt% (percentage by weight) aqueous mixtures of seven NADESs, it was found that MNZ had the highest solubility in water solutions of NADES composed of choline chloride (ChCl) and citric acid (CA). The solubility of MNZ (expressed as 103 mol fraction) increased with the concentration of ChCl:CA NADES (from 6.7743 to 26.8518 at 298.5 K, for 30 and 70 wt% NADES-water mixtures, respectively), and it was more effective when compared to aqueous solutions of individual NADES components with wt% corresponding to these in the NADES-water mixtures. The study also found a preferable mixing of MNZ with aqueous solutions of NADES reflected by negative values of standard molar enthalpy change of mixing (approx. − 4.2 kJ·mol−1), compared with positive values in the case of MNZ mixing with water or ChCl aqueous solutions (approx. 7.3 kJ·mol−1). Comparative research conducted on the volume and acoustics of MNZ in water and aqueous solutions of ChCl, CA, and ChCl:CA NADES also confirmed stronger interactions between the drug and NADES and CA. The dominant interactions between MNZ and co-solvent were hydrophilic-hydrophobic and hydrophobic-hydrophobic. This effect increased in the following strength order: ChCl < NADES < CA. In conclusion, the obtained NADES seems to be a promising co-solvent which provides solid grounds for further research to evaluate the full potential in pharmaceutical design of MNZ liquid formulations.
Solvation phenomena in ternary system tetramethylurea-methylacetamide-water: Insights from volumetric, compressibility and FTIR analysis
- Jarosław Wawer
- Emilia Kaczkowska
- Magdalena Tyczyńska
- Małgorzata Jóźwiak
- Joanna Krakowiak
2024 JOURNAL OF MOLECULAR LIQUIDS
The properties of the ternary systems N,N,N’,N’-tetramethylurea - N-methylacetamide - water were investigated using Fourier-transform infrared spectroscopy (FTIR), volumetric and compression measurements. Densities and sound velocities were determined in order to obtain the apparent molar volumes (VΦ) and apparent molar isentropic compressions (ΚS,Φ). These values were then extrapolated to infinite dilution. Additionally, interaction parameters were calculated from the McMillan-Mayer theory. The studies were conducted at 288.15, 298.15, and 308.15 K, at atmospheric pressure (0.1 MPa). The concentration ranges of N-methylacetamide were 2, 4, 6, and 8 moles per kilogram of pure water, and for N,N,N’,N’-tetramethylurea from 0 to around 0.35 moles per kilogram of solvent. Discrete changes in isentropic compression were observed. This is the result of the alignment of plots of ΚS,Φ 0 as a function of NMA concentration. The results for N,N,N’,N’-tetramethylurea were compared with analogous data for the system containing n-butylurea, which is an isomeric compound but exhibits different hydration behaviour. Additionally, large volumetric interaction coefficients were observed, indicating strong interactions between urea derivatives and NMA. This suggests the possibility of strong interactions between protein destabilizers and the protein backbone, differing from those observed for protein structure stabilizers. The observation contributes to understanding the mechanism of osmolyte action and their influence on protein stability.
Sonocatalytic degradation of Bisphenol A from aquatic matrices over Pd/CeO2 nanoparticles: Kinetics study, transformation products, and toxicity
- Alexandra A. Ioannidi
- Georgios Bampos
- Maria Antonopoulou
- Paula Oulego
- Grzegorz Boczkaj
- Dionisios Mantzavinos
- Zacharias Frontistis
2024 SCIENCE OF THE TOTAL ENVIRONMENT
In this work, different ratios of palladium – cerium oxide (Pd/CeO2) catalyst were synthesized and characterized, while their sonocatalytic activity was evaluated for the degradation of the xenobiotic Bisphenol A (BPA) from aqueous solutions. Sonocatalytic activity expressed as BPA decomposition exhibited a volcano-type behavior in relation to the Pd loading, and the 0.25Pd/CeO2 catalyst characterized by the maximum Pd dispersion and lower crystallite size demonstrated the higher activity. Using 500 mg/L of 0.25 % Pd/CeO2 increased the kinetic constant for BPA destruction by more than two times compared to sonolysis alone (20 kHz at 71 W/L). Meanwhile, the simultaneous use of ultrasound and a catalyst enhanced the efficiency by 50.1 % compared to the sum of the individual processes, resulting in 95 % BPA degradation in 60 min. The sonocatalytic degradation of BPA followed pseudo-first-order kinetics, and the apparent kinetic constant was increased with ultrasound power and catalyst loading, while the efficiency was decreased in bottled water and secondary effluent. From the experiments that were conducted using appropriate scavengers, it was revealed that the degradation mainly occurred on the bubble/liquid interface of the formed cavities, while the reactive species produced from the thermal or light excitation of the prepared semiconductor also participated in the reaction. Five first-stage and four late-stage transformation products were identified using UHPLC/TOF-MS, and a pathway for the sonocatalytic degradation of BPA was proposed. According to ECOSAR software prediction, most transformation by-products (TBPs) present lower ecotoxicity than the parent compound, although some remain toxic to the indicators chosen.
Sonochemical Based Processes for Treatment of Water and Wastewater
- Kirill Fedorov
- Manoj P Rayaroth
- Xun Sun
- Reza Darvishi
- Shirish H. Sonawane
- Noor S. Shah
- Varsha Srivastava
- Zhaohui Wang
- Grzegorz Boczkaj
2024
Sonochemical Based Processes for Treatment of Water and Wastewater - Opportunities and Challenges – A Future Perspective.
Sorbents modified by deep eutectic solvents in microextraction techniques
- Patrycja Makoś-Chełstowska
- Jacek Gębicki
2024 TRAC-TRENDS IN ANALYTICAL CHEMISTRY
In recent years, considerable attention has been directed towards the employment of green solvents, specifically deep eutectic solvents (DES), in liquid phase microextraction techniques. However, comprehensive and organized knowledge regarding the modification of sorbent surface structures with DES remains limited. Therefore, this paper reviews the application of DES in modifying and improving the properties of sorbents for microextraction techniques. The review begins by explaining the criteria for selecting DES as surface modifiers and the types of sorbents. Subsequently, it delves into the diverse techniques employed to modify sorbents using DES, including dip coating, sol-gel coating, polymer monolith coatings, molecular imprinting, electrochemical deposition, and simultaneous DES formation and sorbent impregnation. The impact of these modifications on sorbent selectivity, and durability, extraction efficiency, and environmental sustainability is critically evaluated. Additionally, this paper discusses the applications of DES-modified sorbents in various types of solid-phase extraction and solid-phase microextraction techniques. The review concludes with a discussion of current challenges and future perspectives in the field, including potential avenues for further research.
Sounding Mechanism of a Flue Organ Pipe—A Multi-Sensor Measurement Approach
- Paolo Bordoni
- Piotr Odya
- Józef Kotus
- Bożena Kostek
2024 Full text SENSORS
This work presents an approach that integrates the results of measuring, analyzing, and modeling air flow phenomena driven by pressurized air in a flue organ pipe. The investigation concerns a Bourdon organ pipe. Measurements are performed in an anechoic chamber using the Cartesian robot equipped with a 3D acoustic vector sensor (AVS) that acquires both acoustic pressure and air particle velocity. Also, a high-speed camera is employed to observe the jet coming out from the windway. For that purpose, the steam resulting from dry ice and hot water is used. A numerical simulation of the sounding mechanism of a pipe of the same geometry is based on measuring the pressure signal and the intensity field around the mouth employing an intensity probe and visualizing and observing the motion of the air jet, which represents the excitation mechanism of the system. The ParaVIEW software serves for the simulation and visualization of the air jet. Then, the results obtained from measurements and simulations are compared and discussed. Also, some future directions discussing the application of a machine-learning approach to the area of pipe organ air flow investigation are contained in the Conclusions section.
sp2-rich dendrite-like carbon nanowalls as effective electrode for environmental monitoring of explosive nitroaromatic
- Anna Dettlaff
- Małgorzata Szopińska
- Daniel Houghton
- Piotr Prasuła
- Yisong Han
- Marc Walker
- Geoff West
- Agata Kamieńska-Duda
- Sylwia Fudala-Książek
- Michał Sobaszek
2024 Full text CHEMICAL ENGINEERING JOURNAL
Nitroaromatic compounds are commonly used explosive materials that pose a risk to human health and ecosystems due to their acute toxicity and carcinogenicity. Nitroaromatics have numerous pathways into the environment via discarded munitions (e.g. into the Baltic Sea after World War II), after use in mining operations, and in industrial run-off from factories producing these compounds (which are produced across the world to date). The current detection method relies on chromatography and mass spectrometry methods, which are time-consuming, expensive, and require specialist equipment and training. Carbon-based electrochemical sensors offer a low-cost, fast, and easy on-site method for the detection of a variety of compounds. This study demonstrates an efficient approach for rapid electrochemical sensing of Tetryl (N-methyl-N-2,4,6-tetranitroaniline) through the use of boron-doped sp2-rich carbon structures. These structures, known as dendrite-like carbon nanowalls (D:CNW), were fabricated in one-step deposition and extensively characterized to understand the structure and surface chemistry. Electrodes were used to detect a range of nitroaromatic compounds, most notably tetryl in both laboratory and real environmental samples, with an excellent sensitivity of 153.0 µA cm−2 ppm−1 and a detection limit of 17 ppb. The analytical and electrochemical capabilities of D:CNW electrodes indicate their suitability for extensive environmental monitoring.
SpamVis: A Visual Interactive System for Spam Review Detection
- Nguyen Thanh Thao Lam
- Nu Uyen Phuong Le
- Md Rafiqul Islam
- Cesar Sanin
- Edward Szczerbicki
2024 Full text
In recent times, the number of spam reviews through various online platforms has emerged as a prime challenge, profoundly impacting businesses and consumers. These fake reviews not only distort clients’ perceptions of products and services but also erode trust within the digital ecosystem. Despite the advent of machine learning (ML) techniques for identifying spam reviews, comparing text, and pinpointing groups of spammers, there remain notable gaps in both accuracy and the combination of interactive visualization for real-time decision-making. This paper presents SpamVis, a visual interactive system that leverages deep learning (DL) and ML blended with advanced visualization techniques for spam review detection, enabling analysts to conduct complicated analytical queries. The system allows users to input via click-on or touch to generate interactive charts and plots tailored for spam review analysis. The findings of the baseline test carried out on 67,395 review texts demonstrate that Bidirectional Encoder Representations from Transformers (BERT) carried out the best accuracy (86%) compared to other models. Our outcomes suggest that SpamVis can alleviate the gaps concerning accuracy and visualization needs in contemporary techniques, guiding analysts to make informed decisions for mitigating spam reviews and enhancing consumer trust. Furthermore, SpamVis empowers users to seamlessly discover the online reviews of various social media platforms in real-time, such as Facebook, Youtube, etc., giving them practical insights to navigate the online marketplace effectively
Spatial variability of the hydrochemistry of shallow groundwaters and surface waters of the Rensdyrbekken: A case study of a permafrost catchment in Bellsund (SW Spitsbergen, Svalbard)
- Sara Lehmann-konera
- Piotr Zagorski
- Kamil Nowinski
- Krzysztof Raczynski
- Marcin Frankowski
- Łukasz Franczak
- Mateusz Dobek
- Danuta Szumińska
- Ruman Marek
- Ramia Bakain Al
- Żaneta Polkowska
2024 Full text LAND DEGRADATION & DEVELOPMENT
Progressive climate change may have unpredictable consequences for the Arctic environment. Permafrost catchments off the west coast of Svalbard, described as “thin” and “warm,” are particularly sensitive to climate change. The interdisciplinary research on the hydrochemical response of surface and underground water functioning within a small permafrost catchment area focused on the determination of the impact of meteorological conditions (temperature (T), precipitation (P)) on the mean daily discharge (Q), and the lowering of the groundwater table (H). We determined physical and chemical properties (pH and SEC) and concentrations of major elements (Ca, Mg, Na, K) and 23 trace elements (i.a. Cd, Cu, Hg, Pb, Zn) in 280 water samples. The results of the correlation matrix showed that an increase in the average air temperature in the summer of 2021 had a significant impact on the hydrochemistry of both types of waters operating in the catchment. In response to increase in T, the lowering of the H (0.52 < r < 0.66) and a decrease in Q (0.66 < r < 0.68) were observed what in consequence also leads to changes in water chemistry. The principal component analysis (CA) indicates that chemical weathering and binding of elements to DOC are processes influencing water chemistry. Results of statistical analysis showed that the resultant of the hydrometeorological conditions that prevailed in that season and the type of geological formations on which they were located had a significant impact on the water chemistry at individual measurement points. Significant differences in the concentrations of elements between points on the same geological formations were also found.