2021 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2021

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MRAS-Based Switching Linear Feedback Strategy for Sensorless Speed Control of Induction Motor Drives
- Mohamed Amine Fnaiech
- Jarosław Guziński
- Mohamed Trabelsi
- Abdellah Kouzou
- Mohamed Benbouzid
- Krzysztof Łuksza
2021 Full text ENERGIES
This paper presents a newly designed switching linear feedback structure of sliding mode control (SLF-SMC) plugged with an model reference adaptive system (MRAS) based sensorless fieldoriented control (SFOC) for induction motor (IM). Indeed, the performance of the MRAS depends mainly on the operating point and the parametric variation of the IM. Hence, the sliding mode control (SMC) could be considered a good control alternative due to its easy implementation and robustness. Simulation and experimentation results are presented to show the superiority of the proposed SLF-SMC technique in comparison with the classical PI controller under different speed ranges and inertia conditions.
MRI-Derived Subcutaneous and Visceral Adipose Tissue Reference Values for Children Aged 6 to Under 18 Years
- Kacper Marunowski
- Dominik Świętoń
- Włodzimierz Bzyl
- Małgorzata Grzywińska
- Mariusz Kaszubowski
- Piotr Bandosz
- Dmitry Khrichenko
- Maciej Piskunowicz
2021 Full text Frontiers in Nutrition
The assessment of body composition in pediatric population is essential for proper nutritional support during hospitalization. However, currently available methods have limitations. This study aims to propose a novel approach for nutrition status assessment and introduce magnetic resonance imaging (MRI)-derived subcutaneous and visceral fat normative reference values. A total of 262 healthy subjects aged from 6 to 18 years underwent MRI examinations and anthropometric measurements. MRI images at the second lumbar vertebrae were used by two radiologists to perform the semi-automatic tissue segmentation. Based on obtained adipose tissue surface areas and body mass index (BMI) scores sex-specific standard percentile curves (3rd, 10th, 25th, 50th, 75th, 90th, 97th) and z-scores were constructed using LMS method. Additionally, 85th and 95th centiles of subcutaneous and visceral adipose tissue were proposed as equivalents of overweight and obesity. Bland-Altman plots revealed an excellent intra-observer reproducibility and inter-observer agreement. In conclusion, our findings demonstrate highly reproducible method and suggest that MRI-derived reference values can be implemented in clinical practice.
Multi-Aspect Quality Assessment Of Mobile Image Classifiers For Companion Applications In The Publishing Sector
- Karol Draszawka
2021
The paper presents the problem of quality assessment of image classifiers used in mobile phones for complimentary companion applications. The advantages of using this kind of applications have been described and a Narrator on Demand (NoD) functionality has been described as one of the examples, where the application plays an audio file related to a book page that is physically in front of the phone's camera. For such a NoD application, an image classifier is a key component. A thorough quantitative evaluation of the accuracy and robustness of such classifiers was conducted using 18 books of various sorts, 48 test classifiers and 10 testers. We analyzed the impact of the type and condition of the books that define the page classification problem, the position of the mobile device camera in the image acquisition process, the parameters of mobile devices used in tests, and selected options in a training process of classifiers.
Multicriteria Decision Analysis and Grouping of Analytical Procedures for Phthalates Determination in Disposable Baby Diapers
- Magdalena Fabjanowicz
- Justyna Płotka-Wasylka
- Marek Tobiszewski
2021 Full text MOLECULES
This study presents the application of one of the tools from the multicriteria decision analysis set (MCDA), the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). Selected green analytical chemistry metrics were used to rank analytical procedures for the phthalate determination in disposable baby diapers. Nine analytical procedures were assessed in order to find one that has the lowest environmental impact and the best analytical figures of merit. Nine different criteria, where weighting was based on the experts’ evaluation, were used in the procedures’ assessment. With the use of TOPSIS, an easy and straightforward technique, selection of the most appropriate procedure was made.
Multifaceted Analyses of Four Different Prototype Lightweight Photovoltaic Modules of Novel Structure
- Krzysztof Mik
- Paweł Zawadzki
- Jan Tarłowski
- Marcin Bugaj
- Piotr Grygiel
- Sebastian Bykuć
2021 Full text ENERGIES
Dynamic growth of photovoltaic capacity in Poland encourages many entities to invest in photovoltaic systems. However, in the case of buildings with low roof-bearing capacity it can be problematic or even impossible to mount conventional PV modules due to their relatively high weight. Hence, the use of lightweight PV modules is a potential solution. In this paper four different prototype silicon lightweight modules of novel structure manufactured by the Xdisc S.A have been investigated in terms of their electrical and thermal features. The measurements showed that all prototypes have efficiency exceeding 19.5% and power in range of 214 to 242 Wp at standard test conditions. Their area density is about 3.5 kg/m2 which is typical for lightweight modules. In turn, the Power-to-Weight Ratio exceeds 40 W/kg threshold and in one case reaches almost 58 W/kg. Thanks to the measurements, the prototypes could be modelled in PVsyst (PVsyst SA, Satigny, Switzerland). The performed simulations of an example PV system revealed that installations based on prototypes have comparable performance to a conventional installation. Nevertheless, at current prices they are less profitable than the standard system and it shows the need for future cost reductions in the manufacturing process. The proposed materials selection may be the starting point for search of inexpensive substitutes of these materials which still conserve modules high performance. A system based on the prototypes can still prove advantageous when simplicity and promptness outweigh higher initial costs.
Multimateriałowe oraz wielokolorowe drukowanie wysokiej jakości części z żywic utwardzanych światłem UV w technologii PolyJet
- Dawid Zieliński
2021 Full text Materiały & Maszyny Technologiczne
Możliwość budowania multimateriałowych oraz wielokolorowych elementów stanowi ważny trend w rozwoju technologii żywicznych druku 3D. W niniejszym opracowaniu skupiono się na charakterystyce podstawowej metody przetwarzającej ciekłe fotopolimery – technologii PolyJet. Omówiono zasadę jej działania oraz najważniejsze aspekty procesu dotyczące m.in. parametrów drukarki, stosowanych struktur podporowych oraz rodzaju uzyskiwanej powierzchni wydruków. Wskazano ponadto główne grupy przetwarzanych materiałów wraz z charakterystyką ich wybranych właściwości. W końcowej części pracy zaprezentowano kluczowe korzyści oraz ograniczenia związane z wykorzystaniem technologii PolyJet, jak i również szereg praktycznych wskazówek.
Multi-objective optimization of the cavitation generation unit structure of an advanced rotational hydrodynamic cavitation reactor
- Xun Sun
- Ze Yang
- Xuesong Wei
- Yang Tao
- Grzegorz Boczkaj
- Joon Yong Yoon
- Xiaoxu Xuan
- Songying Chen
2021 Full text ULTRASONICS SONOCHEMISTRY
Hydrodynamic cavitation (HC) has been widely considered a promising technique for industrial-scale process intensifications. The effectiveness of HC is determined by the performance of hydrodynamic cavitation reactors (HCRs). The advanced rotational HCRs (ARHCRs) proposed recently have shown superior performance in various applications, while the research on the structural optimization is still absent. The present study, for the first time, identifies optimal structures of the cavitation generation units of a representative ARHCR by combining genetic algorithm (GA) and computational fluid dynamics, with the objectives of maximizing the total vapor volume, , and minimizing the total torque of the rotor wall, . Four important geometrical factors, namely, diameter (D), interaction distance (s), height (h), and inclination angle (θ), were specified as the design variables. Two high-performance fitness functions for and were established from a central composite design with 25 cases. After performing 10,001 simulations of GA, a Pareto front with 1630 non-dominated points was obtained. The results reveal that the values of s and θ of the Pareto front concentrated on their lower (i.e., 1.5 mm) and upper limits (i.e., 18.75°), respectively, while the values of D and h were scattered in their variation regions. In comparison to the original model, a representative global optimal point increased the by 156% and decreased the by 14%. The corresponding improved mechanism was revealed by analyzing the flow field. The findings of this work can strongly support the fundamental understanding, design, and application of ARHCRs for process intensifications.
Multi-objective Tabu-based Differential Evolution for Teleportation of Smart Virtual Machines in Private Computing Clouds
- Jerzy Balicki
- Piotr Dryja
2021
We propose a multi-objective approach for using differential evolution algorithm with tabu search algorithm as an additional mutation for live migration (teleportation) of virtual machines. This issue is crucial in private computing clouds. Teleportation of virtual machines is supposed to be planned to determine Pareto-optimal solutions for several criteria such as workload of the bottleneck host, communication capacity of the critical node, electric power of hosts, and computer costs. Some numerical results are presented for the experimental cloud based on OpenStack platform for smart city and smart education systems.
Multi-Technique Investigation of Grave Robes from 17th and 18th Century Crypts Using Combined Spectroscopic, Spectrometric Techniques, and New-Generation Sequencing
- Magdalena Śliwka-Kaszyńska
- Marek Ślebioda
- Anna Brillowska-Dąbrowska
- Martyna Mroczyńska
- Jakub Karczewski
- Anna Marzec
- Przemysław Rybiński
- Anna Drążkowska
2021 Full text Materials
The textile fragments of the funeral clothes found in the 17th and 18th century crypts were subjected to spectroscopic, spectrometric, and microbial investigation. The next-generation sequencing enabled DNA identification of microorganisms at the genus and in five cases to the species level. The soft hydrofluoric acid extraction method was optimized to isolate different classes of dyes from samples that had direct contact with human remains. High-performance liquid chromatography coupled with diode matrix and tandem mass spectrometry detectors with electrospray ionization (HPLC-DAD-ESI-MS/MS) enabled the detection and identification of 34 colourants that are present in historical textiles. Some of them are thus far unknown and uncommon dyes. Indigo, madder, cochineal, turmeric, tannin-producing plant, and young fustic were identified as sources of dyes in textiles. Scanning electron microscopy with energy-dispersive X-ray detector (SEM-EDS) and Fourier transform infrared spectroscopy (FT-IR) were used to identify and characterize fibres and mordants in funeral gowns. Of the 23 textile samples tested, 19 were silk while the remaining four were recognized as wool. The presence of iron, aluminium, sodium, and calcium suggests that they were used as mordants. Traces of copper, silica, and magnesium might originate from the contaminants. The large amount of silver indicated the presence of metal wire in one of the dyed silk textiles. SEM images showed that textile fibres were highly degraded.
Multiuser Stereoscopic Projection Techniques for CAVE-Type Virtual Reality Systems
- Jacek Lebiedź
- Adam Mazikowski
2021 Full text IEEE Transactions on Human-Machine Systems
Despite the development of increasingly popular head mounted displays, CAVE-type systems may still be considered one of the most immersive virtual reality systems with many advantages. However, a serious limitation of most CAVE-type systems is the generation of a three-dimensional (3-D) image from the perspective of only one person. This problem is significant because in some applications, the participants must cooperate with each other in the virtual world. This paper presents the adaptation of a one-user CaveAutomaticVirtual Environment (CAVE) installation in the Immersive 3-D Visualization Lab at the Gda´nsk University of Technology to a two-user stereoscopy system. Simultaneous use of two alternative one-user stereoscopies available in the I3DVL (a technique with spectrum separation—Infitec, and active stereo) and a simple electronic circuit have allowed us to transform the one-user stereoscopy CAVE installation to a two-user stereoscopic system. The experiments performed concentrated on several objective measurable parameters. The calculated crosstalk value was low, approximately 1%, which can be considered negligible and shows the proper operation of the proposed technique. Additionally, initial experiments based on the tested two-user application and related to user comfort in the developed two-user stereoscopy are discussed in this paper. However, this topic still needs further research. The proposed solutions are a cheap alternative to adapt the existing one-user CAVE-type systems which support two projection techniques to a two-user system.
Multivariate Assessment of Procedures for Molecularly Imprinted Polymer Synthesis for Pesticides Determination in Environmental and Agricultural Samples
- Mariusz Marć
- Marta Bystrzanowska
- Katarzyna Pokajewicz
- Marek Tobiszewski
2021 Full text Materials
In the case of quantitative and qualitative analysis of pesticides in environmental and food samples, it is required to perform a sample pre-treatment process. It allows to minimalize the impact of interferences on the final results, as well as increase the recovery rate. Nowadays, apart from routinely employed sample preparation techniques such as solid-phase extraction (SPE) or solid-phase microextraction (SPME), the application of molecularly imprinted polymers (MIPs) is gaining greater popularity. It is mainly related to their physicochemical properties, sorption capacity and selectivity, thermo-mechanical resistance, as well as a wide range of polymerization techniques allowing to obtain the desired type of sorption materials, adequate to a specific type of pesticide. This paper targets to summarize the most popular and innovative strategies since 2010, associated with the MIPs synthesis and analytical procedures for pesticides determination in environmental and food samples. Application of multi-criteria decision analysis (MCDA) allows for visualization of the most beneficial analytical procedures in case of changing the priority of each step of analysis (MIPs synthesis, sample preparation process—pesticides extraction, chromatographic analysis) bearing in mind metrological and environmental issues
Multivariate Statistical Approach for Nephrines in Womenwith Obesity
- Ralitsa Robeva
- Miroslava Nedyalkova
- Georgi Kirilov
- Atanaska Elenkova
- Sabina Zacharieva
- Błażej Kudłak
- Natalia Jatkowska
- Vasil Simeonov
2021 Full text MOLECULES
Catecholamines are physiological regulators of carbohydrate and lipid metabolism during stress, but their chronic influence on metabolic changes in obese patients is still not clarified. The present study aimed to establish the associations between the catecholamine metabolites and metabolic syndrome (MS) components in obese women as well as to reveal the possible hidden subgroups of patients through hierarchical cluster analysis and principal component analysis. The 24-h urine excretion of metanephrine and normetanephrine was investigated in 150 obese women (54 non diabetic without MS, 70 non-diabetic with MS and 26 with type 2 diabetes). The interrelations between carbohydrate disturbances, metabolic syndrome components and stress response hormones were studied. Exploratory data analysis was used to determine different patterns of similarities among the patients. Normetanephrine concentrations were significantly increased in postmenopausal patients and in women with morbid obesity, type 2 diabetes, and hypertension but not with prediabetes. Both metanephrine and normetanephrine levels were positively associated with glucose concentrations one hour after glucose load irrespectively of the insulin levels. The exploratory data analysis showed different risk subgroups among the investigated obese women. The development of predictive tools that include not only traditional metabolic risk factors, but also markers of stress response systems might help for specific risk estimation in obesity patients.
NA STYKU LĄDU I WODY - GDAŃSK
- Anna Orchowska-Smolińska
2021 Zawód: Architekt
Na wyjątkowość zasobu kulturowego dawnej Stoczni Gdańskiej składają się różne wartości i czynniki działające na siebie wzajemnie w sposób synergiczny. Obok treści historycznych, związanych z samym zakładem przemysłowym, znajdują się te dotyczące strajków robotniczych i przemian ustrojowych. Dodatkowo, specyfiką krajobrazu przemysłowego, w rozumieniu zabudowy i zagospodarowania, jest pewna „warstwowość”, a dla obserwatora z zewnątrz czasem niezrozumiałe zagęszczenie i chaotyczność. W rzeczywistości są one wynikiem dostosowywania struktury przestrzennej i modyfikacji ciągów technologicznych do nowych potrzeb. Można zatem powiedzieć, że układ ten rozważnie wpisuje nowe potrzeby eksploatacyjne w zastaną przestrzeń. A co z przyszłością tego terenu? Bliższe poznanie zespołu dysponującego całym wachlarzem zasobów, wartości, atutów i symboliki karze postawić sobie szereg pytań o sposoby dalszego postępowania. Jak poprowadzić proces planowanych na tym terenie inwestycji i jak zarządzać dziedzictwem stoczni, by miejsce to dalej żyło? Czy możliwy jest rozwój tego terenu symbiotycznie powiązany z jego ochroną? Jak uszlachetnić jego dziedzictwo, nie redefiniując cennego przekazu? Czy możliwe jest przekształcenie tego terenu zapewniające jego dostępność i przystępność dla wszystkich? Jak sprawić, by dzielnica ta wciąż mówiła o sobie jako o dawnej stoczni, nie będąc sztucznym tworem dla elit? Na te i wiele innych pytań szukamy wciąż odpowiedzi.
Najczęstsze problemy usługowych środowisk wdrożeniowych
- Andrzej Sobecki
2021
Zakres dostępnych obecnie rozwiązań informatycznych umożliwia zna- czące usprawnienie procesu wytwarzania i dostarczania oprogramowania do klienta. Poprawna integracja środowiska wytwórczego pozwala wy- eliminować szereg problemów dotyczących wewnętrznej współpracy ze- społów developerskich. Zmiana architektur aplikacji z monolitycznych na rozproszone heterogeniczne zbiory usług wymaga innego podejścia do wdrażania usług. Dotychczasowe metody wydają się być nieefektywne i mogą istotnie zwiększać koszty operacyjne. Nowe typy narzędzi i bi- bliotek pozwalają wreszcie na pełną automatyzację procesu konfiguracji i wdrażania usług, utrzymywania ich wysokiej dostępności oraz dostar- czają nowe mechanizmy zabezpieczania usług. Są one również dostoso- wane m.in. do wykorzystania chmur obliczeniowych, które oferują znacz- nie większa funkcjonalność niż jedynie zbiór połączonych ze sobą serwe- rów. W rozdziale opisano nowoczesne architektury oprogramowania, ich wymagania względem środowiska wdrożeniowego oraz zaprezentowano przykład takiego środowiska. Przy czym nie jest wymagane posiadanie chmury obliczeniowej, aby skorzystać z przedstawianych mechanizmów.
Nanosilver-loaded PMMA bone cement doped with different bioactive glasses – evaluation of cytocompatibility, antibacterial activity, and mechanical properties
- Marcin Wekwejt
- Si Chen
- Beata Kaczmarek
- Małgorzata Nadolska
- Krzysztof Łukowicz
- Anna Pałubicka
- Anna Michno
- Anna Maria Osyczka
- Martin Michalek
- Andrzej Zieliński
2021 Full text Biomaterials Science
Nanosilver-loaded PMMA bone cement (BC-AgNp) is a novel cement developed as a replacement for conventional cements. Despite favorable properties and antibacterial activity, BC-AgNp still lacks biodegradability and bioactivity. Hence, we investigated the doping with bioactive glasses (BGs) to create a new bioactive BC characterized by time-varying porosity and gradual release of nanosilver. The BC Cemex was used as the base material and modified simultaneously with the AgNp and BGs: melted 45S5 and 13-93B3 glasses with various particles size and sol-gel derived SiO2/CaO microparticles. The effect of BGs addition was examined by microscopic analysis, an assessment of setting parameters, wettability, FTIR and UV-VIS spectroscopy, mechanical testing, hemo- and cytocompatibility and antibacterial efficiency studies. The results show that it is possible to incorporate various BGs into BC-AgNp that lead to different properties depending on the type and size of BGs. The smaller particles of melted BGs showed higher porosity and better antibacterial properties with the moderate deterioration of mechanical properties. The sol-gel derived BGs, however, displayed a tendency for agglomeration and random distribution in BC-AgNp. The BGs with greater solubility more efficiently improves the antibacterial properties of BC-AgNp. Besides, the unreacted MMA monomer release could negatively influence the cellular response. Despite that, the cements doped with different bioactive glasses are suitable for medical applications.
Nanotechnologie w implantologii – osiągnięcia i wyzwania
- Michał Bartmański
2021
Aktualnie nanotechnologia jest jedną z najszybciej rozwijających się gałęzi przemysłu, w tym również w zakresie medycyny i implantologii. Osiągnięcia nanotechnologii wykorzystuje się w obrazowaniu, diagnostyce, leczeniu chorób nowotworowych i bólu, lecz również szeroko w obszarze projektowania i wytwarzania implantów, w tym głownie modyfikacji powierzchni materiałów, które mają za zadanie chwilowo lub permanentnie zastąpić funkcję naturalnej tkanki lub narządu. Najczęściej wykorzystywanymi materiałami na implanty długotrwałe są tytan i jego stopy, ze względu na odpowiednie właściwości mechaniczne, chemiczne i wysoką biokompaty-bilność. W zakresie interakcji implantu z tkanką, głównie kostną, to powierzchnia materiału implantowanego odgrywa kluczową rolę. W celu nadania lepszych właściwości powierzchniowych implantu, głównie mecha-nicznych i biologicznych, stosuje się wiele metod modyfikacji powierzchni wykorzystujących osiągnięcia nanotechnologii. Wśród nich między innymi wykorzystywanie metalicznych nanocząstek o udowodnionym działaniu antybakteryjnym w celu nadania implantom właściwości biobójczych w obrębie wszczepu. Innymi metodami pozostają elektrolityczne wytwarzanie nano-rurkowych warstw ditlenku tytanu czy osadzanie powłok o grubościach nanometrycznych, głównie na bazie fosforanów wapnia, lub po prostu osadzanie powłok i wytwarzanie warstw z dodatkiem nanocząstek. W prezentacji przedstawione zostaną główne osiągnięcia w zakresie wyko-rzystania nanotechnologii w implantologii oraz omówione zostaną kwestie wciąż nierozwiązane, a które pozostają wyzwaniem dla naukowców z całego świata.
Nanotubular Oxide Layer Formed on Helix Surfaces of Dental Screw Implants
- Magdalena Jażdżewska
- Michał Bartmański
2021 Full text Coatings
Surface modification is used to extend the life of implants. To increase the corrosion resistance and improve the biocompatibility of metal implant materials, oxidation of the Ti-13Nb- 13Zr titanium alloy was used. The samples used for the research had the shape of a helix with a metric thread, with their geometry imitating a dental implant. The oxide layer was produced by a standard electrochemical method in an environment of 1M H3PO4 + 0.3% HF for 20 min, at a constant voltage of 30 V. The oxidized samples were analyzed with a scanning electron microscope. Nanotubular oxide layers with internal diameters of 30–80 nm were found. An analysis of the surface topography was performed using an optical microscope, and the Sa parameter was determined for the top of the helix and for the bottom, where a significant difference in value was observed. The presence of the modification layer, visible at the bottom of the helix, was confirmed by analyzing the sample cross-sections using computed tomography. Corrosion tests performed in the artificial saliva solution demonstrated higher corrosion current and less noble corrosion potential due to incomplete surface coverage and pitting. Necessary improved oxidation parameters will be applied in future work.
Natural Products Counteracting Cardiotoxicity during Cancer Chemotherapy: The Special Case of Doxorubicin, a Comprehensive Review
- Izabela Koss-Mikołajczyk
- Vanja Todorovic
- Sladjana Sobajic
- Jamal Mahajna
- Marko Gerić
- Josep Tur
- Agnieszka Bartoszek-Pączkowska
2021 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Cardiotoxicity is a frequent undesirable phenomenon observed during oncological treatment that limits the therapeutic dose of antitumor drugs and thus may decrease the effec-‐‑ tiveness of cancer eradication. Almost all antitumor drugs exhibit toxic properties towards cardiac muscle. One of the underlying causes of cardiotoxicity is stimulation of oxidative stress by chem-‐‑ otherapy. This suggests that an appropriately designed diet or dietary supplements based on edi-‐‑ ble plants rich in antioxidants could decrease the toxicity of antitumor drugs and diminish the risk of cardiac failure. This comprehensive review compares the cardioprotective efficacy of edible plant extracts and foodborne phytochemicals whose beneficial activity was demonstrated in vari-‐‑ ous models in vivo and in vitro. The studies selected for this review concentrated on a frequently applied in cancer therapy anthracycline antibiotic – doxorubicin -‐‑ as the oxidative stress and car-‐‑ diotoxicity inducing agent.
Nauka w świecie cyfrowym okiem młodego inżyniera - phishing w mediach elektronicznych
- Dominika Bieńkowska
- Przemysław Falkowski-Gilski
2021 Pismo PG
Phishing to metoda oszustwa, w której przestępca podszywa się pod inną osobę lub instytucję w celu wyłudzenia poufnych danych, zainstalowania szkodliwego oprogramowania bądź też nakłonienia ofiary do wykonania określonych zadań. Jest to przestępstwo wykorzystujące zarówno metody socjotechniczne, jak i sztuczki technologiczne do osiągnięcia zaplanowanego celu. Działania hakerów żerują na nieostrożnych ofiarach, skłaniając je do uwierzenia, że mają do czynienia z zaufanym źródłem.
NbIr 2 B 2 and TaIr 2 B 2 – New Low Symmetry Noncentrosymmetric Superconductors with Strong Spin–Orbit Coupling
- Karolina Górnicka
- Xin Gui
- Bartlomiej Wiendlocha
- Loi T. Nguyen
- Weiwei Xie
- Robert J. Cava
- Tomasz Klimczuk
2021 ADVANCED FUNCTIONAL MATERIALS
Superconductivity was first observed more than a century ago, but the search for new superconducting materials remains a challenge. The Cooper pairs in superconductors are ideal embodiments of quantum entanglement. Thus, novel superconductors can be critical for both learning about electronic systems in condensed matter and for possible application in future quantum technologies. Here two previously unreported materials, NbIr2B2 and TaIr2B2, are presented with superconducting transitions at 7.2 and 5.2 K, respectively. They display a unique noncentrosymmetric crystal structure, and for both compounds the magnetic field that destroys the superconductivity at 0 K exceeds one of the fundamental characteristics of conventional superconductors (the “Pauli limit”), suggesting that the superconductivity may be unconventional. Supporting this experimentally based deduction, first-principle calculations show a spinsplit Fermi surface due to the presence of strong spin–orbit coupling. These materials may thus provide an excellent platform for the study of unconventional superconductivity in intermetallic compounds.